Energy Calibration of the Pixels of Spectral X-ray Detectors

CERN Document Server

Panta, Raj Kumar; Bell, Stephen T; Anderson, Nigel G; Butler, Anthony P; Butler, Philip H

2015-01-01

The energy information acquired using spectral X-ray detectors allows noninvasive identification and characterization of chemical components of a material. To achieve this, it is important that the energy response of the detector is calibrated. The established techniques for energy calibration are not practical for routine use in pre-clinical or clinical research environment. This is due to the requirements of using monochromatic radiation sources such as synchrotron, radio-isotopes, and prohibitively long time needed to set up the equipment and make measurements. To address these limitations, we have developed an automated technique for calibrating the energy response of the pixels in a spectral X-ray detector that runs with minimal user intervention. This technique uses the X-ray tube voltage (kVp) as a reference energy, which is stepped through an energy range of interest. This technique locates the energy threshold where a pixel transitions from not-counting (off) to counting (on). Similarly, we have deve...

Toward Improved Modeling of Spectral Solar Irradiance for Solar Energy Applications: Preprint

Energy Technology Data Exchange (ETDEWEB)

Xie, Yu [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sengupta, Manajit [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-10-19

This study introduces the National Renewable Energy Laboratory's (NREL's) recent efforts to extend the capability of the Fast All-sky Radiation Model for Solar applications (FARMS) by computing spectral solar irradiances over both horizontal and inclined surfaces. A new model is developed by computing the optical thickness of the atmosphere using a spectral irradiance model for clear-sky conditions, SMARTS2. A comprehensive lookup table (LUT) of cloud bidirectional transmittance distribution functions (BTDFs) is precomputed for 2002 wavelength bands using an atmospheric radiative transfer model, libRadtran. The solar radiation transmitted through the atmosphere is given by considering all possible paths of photon transmission and the relevent scattering and absorption attenuation. Our results indicate that this new model has an accuracy that is similar to that of state-of-the-art radiative transfer models, but it is significantly more efficient.

Electron-energy-loss spectral library and its application to materials science

Energy Technology Data Exchange (ETDEWEB)

Zaluzec, N.J.

1983-09-01

An electron energy loss spectral library can be an invaluable tool in materials research from a fundamental as well as a practical standpoint. Although it will not alleviate all the complications associated with quantification, this type of library can help to elucidate details of spectral profiles previously found intractable. This work was supported by the US Department of Energy. The author also wishes to express his gratitude to the organizing committee for partial financial support provided to attend this meeting.

Wave propagation of spectral energy content in a granular chain

NARCIS (Netherlands)

Shrivastava, Rohit Kumar; Luding, Stefan

2017-01-01

A mechanical wave is propagation of vibration with transfer of energy and momentum. Understanding the spectral energy characteristics of a propagating wave through disordered granular media can assist in understanding the overall properties of wave propagation through inhomogeneous materials like

Spectral State Evolution of 4U 1820-30: the Stability of the Spectral Index of Comptonization Tail

Science.gov (United States)

Titarchuk, Lev G.; Seifina, Elena; Frontera, Filippo

2013-01-01

We analyze the X-ray spectra and their timing properties of the compact Xray binary 4U 1820-30. We establish spectral transitions in this source seen with BeppoSAX and the Rossi X-ray Timing Explorer (RXTE). During the RXTE observations (1996 - 2009), the source were approximately approximately 75% of its time in the soft state making the lower banana and upper banana transitions combined with long-term low-high state transitions. We reveal that all of the X-ray spectra of 4U 1820-30 are fit by a composition of a thermal (blackbody) component, a Comptonization component (COMPTB) and a Gaussian-line component. Thus using this spectral analysis we find that the photon power-law index Gamma of the Comptonization component is almost unchangeable (Gamma approximately 2) while the electron temperature kTe changes from 2.9 to 21 keV during these spectral events. We also establish that for these spectral events the normalization of COMPTB component (which is proportional to mass accretion rate ?M) increases by factor 8 when kTe decreases from 21 keV to 2.9 keV. Before this index stability effect was also found analyzing X-ray data for Z-source GX 340+0 and for atolls, 4U 1728-34, GX 3+1. Thus, we can suggest that this spectral stability property is a spectral signature of an accreting neutron star source. On the other hand in a black hole binary G monotonically increases with ?Mand ultimately its value saturates at large ?M.

RAPID SPECTRAL CHANGES OF CYGNUS X-1 IN THE LOW/HARD STATE WITH SUZAKU

Energy Technology Data Exchange (ETDEWEB)

Yamada, S.; Makishima, K. [Cosmic Radiation Laboratory, Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-0198 (Japan); Negoro, H. [Department of Physics, College of Science and Technology, Nihon University, 1-8 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Torii, S.; Noda, H. [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Mineshige, S. [Department of Astronomy, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan)

2013-04-20

Rapid spectral changes in the hard X-ray on a timescale down to {approx}0.1 s are studied by applying a ''shot analysis'' technique to the Suzaku observations of the black hole binary Cygnus X-1, performed on 2008 April 18 during the low/hard state. We successfully obtained the shot profiles, covering 10-200 keV with the Suzaku HXD-PIN and HXD-GSO detector. It is notable that the 100-200 keV shot profile is acquired for the first time owing to the HXD-GSO detector. The intensity changes in a time-symmetric way, though the hardness changes in a time-asymmetric way. When the shot-phase-resolved spectra are quantified with the Compton model, the Compton y-parameter and the electron temperature are found to decrease gradually through the rising phase of the shot, while the optical depth appears to increase. All the parameters return to their time-averaged values immediately within 0.1 s past the shot peak. We have not only confirmed this feature previously found in energies below {approx}60 keV, but also found that the spectral change is more prominent in energies above {approx}100 keV, implying the existence of some instant mechanism for direct entropy production. We discuss possible interpretations of the rapid spectral changes in the hard X-ray band.

Investigation of JI and DI CMOS FXR response at different spectral energies

International Nuclear Information System (INIS)

Honnold, V.R.; Goldberg, M.; Schreiner, W.A.; Witteles, A.A.

1975-01-01

The transient response of both junction isolated (JI) and dielectrically isolated (DI) CMOS circuits has been investigated in three FXR environments of differing energy spectrums. The offset recovery times have been measured and analyzed for both structures. It is shown that while the DI circuit (HD4007) did not exhibit a four layer type latchup action, its transient response persisted for a time longer than is expected for this type of device. A possible mechanism for this observed response is developed and discussed. JI circuits (CD4007) exposed under the same conditions exhibited four layer device action and one sample at low spectral energies latched-up. The conditions for the latchup to occur including the four layer device paths are discussed. Finally, the dependence of the x-ray transient response on the spectral energy is considered. For the lower energy FXR source, latchup was observed in a CD4007 sample. This latchup was not observed at more than double the dose rate when a high energy FXR was used. This result is attributed to dose enhancement, and a device enhancement factor may also be involved. The dose enhancement factor is estimated from the work of Long, and points up the importance of accounting for the spectral energy content in simulating a given nuclear threat spectrum

A state space algorithm for the spectral factorization

NARCIS (Netherlands)

Kraffer, F.; Kraffer, F.; Kwakernaak, H.

1997-01-01

This paper presents an algorithm for the spectral factorization of a para-Hermitian polynomial matrix. The algorithm is based on polynomial matrix to state space and vice versa conversions, and avoids elementary polynomial operations in computations; It relies on well-proven methods of numerical

Energy-saving approaches to solid state street lighting

Science.gov (United States)

Vitta, Pranciškus; Stanikūnas, Rytis; Tuzikas, Arūnas; Reklaitis, Ignas; Stonkus, Andrius; Petrulis, Andrius; Vaitkevičius, Henrikas; Žukauskas, Artūras

2011-10-01

We consider the energy-saving potential of solid-state street lighting due to improved visual performance, weather sensitive luminance control and tracking of pedestrians and vehicles. A psychophysical experiment on the measurement of reaction time with a decision making task was performed under mesopic levels of illumination provided by a highpressure sodium (HPS) lamp and different solid-state light sources, such as daylight and warm-white phosphor converted light-emitting diodes (LEDs) and red-green-blue LED clusters. The results of the experiment imply that photopic luminances of road surface provided by solid-state light sources with an optimized spectral power distribution might be up to twice as low as those provided by the HPS lamp. Dynamical correction of road luminance against road surface conditions typical of Lithuanian climate was estimated to save about 20% of energy in comparison with constant-level illumination. The estimated energy savings due to the tracking of pedestrians and vehicles amount at least 25% with the cumulative effect of intelligent control of at least 40%. A solid-state street lighting system with intelligent control was demonstrated using a 300 m long test ground consisting of 10 solid-state street luminaires, a meteorological station and microwave motion sensor network operated via power line communication.

Wave propagation of spectral energy content in a granular chain

Directory of Open Access Journals (Sweden)

Shrivastava Rohit Kumar

2017-01-01

Full Text Available A mechanical wave is propagation of vibration with transfer of energy and momentum. Understanding the spectral energy characteristics of a propagating wave through disordered granular media can assist in understanding the overall properties of wave propagation through inhomogeneous materials like soil. The study of these properties is aimed at modeling wave propagation for oil, mineral or gas exploration (seismic prospecting or non-destructive testing of the internal structure of solids. The focus is on the total energy content of a pulse propagating through an idealized one-dimensional discrete particle system like a mass disordered granular chain, which allows understanding the energy attenuation due to disorder since it isolates the longitudinal P-wave from shear or rotational modes. It is observed from the signal that stronger disorder leads to faster attenuation of the signal. An ordered granular chain exhibits ballistic propagation of energy whereas, a disordered granular chain exhibits more diffusive like propagation, which eventually becomes localized at long time periods. For obtaining mean-field macroscopic/continuum properties, ensemble averaging has been used, however, such an ensemble averaged spectral energy response does not resolve multiple scattering, leading to loss of information, indicating the need for a different framework for micro-macro averaging.

Spectrally and Energy Efficient OFDM (SEE-OFDM) for Intensity Modulated Optical Wireless Systems

OpenAIRE

Lam, Emily; Wilson, Sarah Kate; Elgala, Hany; Little, Thomas D. C.

2015-01-01

Spectrally and energy efficient orthogonal frequency division multiplexing (SEE-OFDM) is an optical OFDM technique based on combining multiple asymmetrically clipped optical OFDM (ACO-OFDM) signals into one OFDM signal. By summing different components together, SEE-OFDM can achieve the same spectral efficiency as DC-biased optical OFDM (DCO-OFDM) without an energy-inefficient DC-bias. This paper introduces multiple methods for decoding a SEE-OFDM symbol and shows that an iterative decoder wit...

Limiting absorption principle at low energies for a mathematical model of weak interaction: the decay of a boson; Proprietes spectrales et principe d'absorption limite a faible energie pour un modele mathematique d'interaction faible: la desintegration d'un boson

Energy Technology Data Exchange (ETDEWEB)

Barbarouxa, J.M. [Centre de Physique Theorique, 13 - Marseille (France); Toulon-Var Univ. du Sud, Dept. de Mathematiques, 83 - La Garde (France); Guillot, J.C. [Centre de Mathematiques Appliquees, UMR 7641, Ecole Polytechnique - CNRS, 91 - Palaiseau (France)

2009-09-15

We study the spectral properties of a Hamiltonian describing the weak decay of spin 1 massive bosons into the full family of leptons. We prove that the considered Hamiltonian is self-adjoint, with a unique ground state and we derive a Mourre estimate and a limiting absorption principle above the ground state energy and below the first threshold, for a sufficiently small coupling constant. As a corollary, we prove absence of eigenvalues and absolute continuity of the energy spectrum in the same spectral interval. (authors)

Spectral and energy efficiency analysis of uplink heterogeneous networks with small-cells on edge

KAUST Repository

Shakir, Muhammad Zeeshan

2014-12-01

This paper presents a tractable mathematical framework to analyze the spectral and energy efficiency of an operator initiated deployment of the small-cells (e.g., femtocells) where the small-cell base stations are deliberately positioned around the edge of the macrocell. The considered deployment facilitates the cell-edge mobile users in terms of their coverage, spectral, and energy efficiency and is referred to as cell-on-edge (COE) configuration. The reduction in energy consumption is achieved by considering fast power control where the mobile users transmit with adaptive power to compensate the path loss, shadowing and fading. In particular, we develop a moment generating function (MGF) based approach to derive analytical bounds on the area spectral efficiency and exact expressions for the energy efficiency of the mobile users in the considered COE configuration over generalized-K fading channels. Besides the COE configuration, the derived bounds are also shown to be useful in evaluating the performance of random small-cell deployments, e.g., uniformly distributed small-cells. Simulation results are presented to demonstrate the improvements in spectral and energy efficiency of the COE configuration with respect to macro-only networks and other unplanned deployment strategies. © 2014 Elsevier B.V. All rights reserved.

Dual-energy contrast-enhanced spectral mammography (CESM).

Science.gov (United States)

Daniaux, Martin; De Zordo, Tobias; Santner, Wolfram; Amort, Birgit; Koppelstätter, Florian; Jaschke, Werner; Dromain, Clarisse; Oberaigner, Willi; Hubalek, Michael; Marth, Christian

2015-10-01

Dual-energy contrast-enhanced mammography is one of the latest developments in breast care. Imaging with contrast agents in breast cancer was already known from previous magnetic resonance imaging and computed tomography studies. However, high costs, limited availability-or high radiation dose-led to the development of contrast-enhanced spectral mammography (CESM). We reviewed the current literature, present our experience, discuss the advantages and drawbacks of CESM and look at the future of this innovative technique.

Analysis spectral shapes from California and central United States ground motion

International Nuclear Information System (INIS)

1994-01-01

The objective of this study is to analyze the spectral shapes from earthquake records with magnitudes and distances comparable to those that dominate seismic hazard at Oak Ridge, in order to provide guidance for the selection of site-specific design-spectrum shapes for use in Oak Ridge. The authors rely heavily on California records because the number of relevant records from the central and eastern United States (CEUS) is not large enough for drawing statistically significant conclusions. They focus on the 0.5 to 10-Hz frequency range for two reasons: (1) this is the frequency range of most engineering interest, and (2) they avoid the effect of well-known differences in the high-frequency energy content between California and CEUS ground motions

Rotational energy transfer of the A{sup 2}{Sigma}`({nu}`=1) state of OH

Energy Technology Data Exchange (ETDEWEB)

Beaud, P; Radi, P; Frey, H B; Mischler, B; Tzannis, A P; Gerber, T [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1997-06-01

Spectrally and temporally resolved laser excited fluorescence of OH is investigated in the picosecond time domain. The total rotational energy transfer (RET) rate from the excited state is determined from the experimental data. Simulated spectra obtained by modelling RET with the energy corrected sudden approximation agree well with the measured spectra. (author) 1 fig., 1 tab., 5 refs.

Coherent Structures and Spectral Energy Transfer in Turbulent Plasma: A Space-Filter Approach

Science.gov (United States)

Camporeale, E.; Sorriso-Valvo, L.; Califano, F.; Retinò, A.

2018-03-01

Plasma turbulence at scales of the order of the ion inertial length is mediated by several mechanisms, including linear wave damping, magnetic reconnection, the formation and dissipation of thin current sheets, and stochastic heating. It is now understood that the presence of localized coherent structures enhances the dissipation channels and the kinetic features of the plasma. However, no formal way of quantifying the relationship between scale-to-scale energy transfer and the presence of spatial structures has been presented so far. In the Letter we quantify such a relationship analyzing the results of a two-dimensional high-resolution Hall magnetohydrodynamic simulation. In particular, we employ the technique of space filtering to derive a spectral energy flux term which defines, in any point of the computational domain, the signed flux of spectral energy across a given wave number. The characterization of coherent structures is performed by means of a traditional two-dimensional wavelet transformation. By studying the correlation between the spectral energy flux and the wavelet amplitude, we demonstrate the strong relationship between scale-to-scale transfer and coherent structures. Furthermore, by conditioning one quantity with respect to the other, we are able for the first time to quantify the inhomogeneity of the turbulence cascade induced by topological structures in the magnetic field. Taking into account the low space-filling factor of coherent structures (i.e., they cover a small portion of space), it emerges that 80% of the spectral energy transfer (both in the direct and inverse cascade directions) is localized in about 50% of space, and 50% of the energy transfer is localized in only 25% of space.

Algorithms for spectral calibration of energy-resolving small-pixel detectors

International Nuclear Information System (INIS)

Scuffham, J; Veale, M C; Wilson, M D; Seller, P

2013-01-01

Small pixel Cd(Zn)Te detectors often suffer from inter-pixel variations in gain, resulting in shifts in the individual energy spectra. These gain variations are mainly caused by inclusions and defects within the crystal structure, which affect the charge transport within the material causing a decrease in the signal pulse height. In imaging applications, spectra are commonly integrated over a particular peak of interest. This means that the individual pixels must be accurately calibrated to ensure that the same portion of the spectrum is integrated in every pixel. The development of large-area detectors with fine pixel pitch necessitates automated algorithms for this spectral calibration, due to the very large number of pixels. Algorithms for automatic spectral calibration require accurate determination of characteristic x-ray or photopeak positions on a pixelwise basis. In this study, we compare two peak searching spectral calibration algorithms for a small-pixel CdTe detector in gamma spectroscopic imaging. The first algorithm uses rigid search ranges to identify peaks in each pixel spectrum, based on the average peak positions across all pixels. The second algorithm scales the search ranges on the basis of the position of the highest-energy peak relative to the average across all pixels. In test spectra acquired with Tc-99m, we found that the rigid search algorithm failed to correctly identify the target calibraton peaks in up to 4% of pixels. In contrast, the scaled search algorithm failed in only 0.16% of pixels. Failures in the scaled search algorithm were attributed to the presence of noise events above the main photopeak, and possible non-linearities in the spectral response in a small number of pixels. We conclude that a peak searching algorithm based on scaling known peak spacings is simple to implement and performs well for the spectral calibration of pixellated radiation detectors

Fermi energy 5f spectral weight variation in uranium alloys

Energy Technology Data Exchange (ETDEWEB)

Denlinger, J.D.; Clack, J.; Allen, J.W. [Univ. of Michigan, Ann Arbor, MI (United States)] [and others

1997-04-01

Uranium materials display a wide range of thermal, electrical and magnetic properties, often exotic. For more than a decade there have been efforts to use photoemission spectroscopy to develop a systematic and unified understanding of the 5f electron states giving rise to this behavior. These efforts have been hampered by a paucity of systems where changes in transport properties are accompanied by substantial spectral changes, so as to allow an attempt to correlate the two kinds of properties within some model. The authors have made resonant photoemission measurements to extract the 5f spectral weight in three systems which show varying degrees of promise of permitting such an attempt, Y{sub 1{minus}x}U{sub x}Pd{sub 3}, U(Pd{sub x}Pt{sub 1{minus}x}){sub 3} and U(Pd{sub x}Cu{sub 1{minus}x}){sub 5}. They have also measured U 4f core level spectra. The 4f spectra can be modeled with some success by the impurity Anderson model (IAM), and the 5f spectra are currently being analyzed in that framework. The IAM characterizes the 5f-electrons of a single site by an f binding energy {epsilon}{sub f}, an f Coulomb interaction and a hybridization V to conduction electrons. Latent in the model are the phenomena of 5f mixed valence and the Kondo effect.

Deuterium depleted water effect on seawater spectral energy and marine phytoplankton

International Nuclear Information System (INIS)

Mirza, Maria; Zaharia, Mihaela; Cristescu, T.M.; Titescu, Gh.

2002-01-01

Solar radiation is the primary source of new energy in most aquatic ecosystems and it is the sun variability in amount and spectral distribution that drives many of the changes in material flux on different time and space scales. The dependency of ecosystem dynamics on sunlight is largely attributable to the simple fact that plants require solar radiation to carry out photosynthesis. The resulting primary production (the rate of the plant growth and reproduction) is an index of aquatic processes, including food web dynamics and biogeochemical cycling of compounds that affect everything from aquatic chemistry to regional and global weather patterns. Light dependent processes in plants (photo-synthesis, photoinhibition, phototaxis and photoprotection) and in aquatic environment, animal vision and microbial mediation of the photo-dissociation of chemical have evolved over millennia and most of them are regulated or at least influenced by the spectral composition of the light field The paper deals with the investigation of relations between water spectral energy modified by deuterium depleted water (DDW) and the microphyte alga Tetraselmis suecica or the total marine micro-phytoplankton growth. (authors)

SNSEDextend: SuperNova Spectral Energy Distributions extrapolation toolkit

Science.gov (United States)

Pierel, Justin D. R.; Rodney, Steven A.; Avelino, Arturo; Bianco, Federica; Foley, Ryan J.; Friedman, Andrew; Hicken, Malcolm; Hounsell, Rebekah; Jha, Saurabh W.; Kessler, Richard; Kirshner, Robert; Mandel, Kaisey; Narayan, Gautham; Filippenko, Alexei V.; Scolnic, Daniel; Strolger, Louis-Gregory

2018-05-01

SNSEDextend extrapolates core-collapse and Type Ia Spectral Energy Distributions (SEDs) into the UV and IR for use in simulations and photometric classifications. The user provides a library of existing SED templates (such as those in the authors' SN SED Repository) along with new photometric constraints in the UV and/or NIR wavelength ranges. The software then extends the existing template SEDs so their colors match the input data at all phases. SNSEDextend can also extend the SALT2 spectral time-series model for Type Ia SN for a "first-order" extrapolation of the SALT2 model components, suitable for use in survey simulations and photometric classification tools; as the code does not do a rigorous re-training of the SALT2 model, the results should not be relied on for precision applications such as light curve fitting for cosmology.

Steady-state emission of blazars at very high energies

International Nuclear Information System (INIS)

Hoehne-Moench, Daniel

2010-01-01

One key scientific program of the MAGIC telescope project is the discovery and detection of blazars. They constitute the most prominent extragalactic source class in the very high energy (VHE) γ-ray regime with 29 out of 34 known objects. Therefore a major part of the available observation time was spent in the last years on high-frequency peaked blazars. The selection criteria were chosen to increase the detection probability. As the X-ray flux is believed to be correlated to the VHE γ-ray flux, only X-ray selected sources with a flux F X >2 μJy at 1 keV were considered. To avoid strong attenuation of the -rays in the extragalactic infrared background, the redshift was restricted to values between z X-γ between the X-ray range at 1 keV and the VHE γ-ray regime at 200 GeV were calculated. The majority of objects show a spectral behaviour as expected from the source class of HBLs: The energy output in the VHE regime is in general lower than in X-rays. For the stacked blazar sample the broad-band spectral index was calculated to α X-γ =1.09, confirming the result found for the individual objects. Another evidence for the revelation of the baseline emission is the broad-band spectral energy distribution (SED) comprising archival as well as contemporaneous multi-wavelength data from the radio to the VHE band. The SEDs of known VHE γ-ray sources in low flux states matches well the SED of the stacked blazar sample. (orig.)

CO-ANALYSIS OF SOLAR MICROWAVE AND HARD X-RAY SPECTRAL EVOLUTIONS. I. IN TWO FREQUENCY OR ENERGY RANGES

International Nuclear Information System (INIS)

Song Qiwu; Huang Guangli; Nakajima, Hiroshi

2011-01-01

Solar microwave and hard X-ray spectral evolutions are co-analyzed in the 2000 June 10 and 2002 April 10 flares, and are simultaneously observed by the Owens-Valley Solar Array in the microwave band and by Yohkoh/Hard X-ray Telescope or RHESSI in the hard X-ray band, with multiple subpeaks in their light curves. The microwave and hard X-ray spectra are fitted by a power law in two frequency ranges of the optical thin part and two photon energy ranges, respectively. Similar to an earlier event in Shao and Huang, the well-known soft-hard-soft pattern of the lower energy range changed to the hard-soft-hard (HSH) pattern of the higher energy range during the spectral evolution of each subpeak in both hard X-ray flares. This energy dependence is actually supported by a positive correlation between the overall light curves and spectral evolution in the lower energy range, while it becomes an anti-correlation in the higher energy range. Regarding microwave data, the HSH pattern appears in the spectral evolution of each subpeak in the lower frequency range, which is somewhat similar to Huang and Nakajima. However, it returns back to the well-known pattern of soft-hard-harder for the overall spectral evolution in the higher frequency range of both events. This frequency dependence is confirmed by an anti-correlation between the overall light curves and spectral evolution in the lower frequency range, but it becomes a positive correlation in the higher frequency range. The possible mechanisms are discussed, respectively, for reasons why hard X-ray and microwave spectral evolutions have different patterns in different energy and frequency intervals.

Spectrally selective glazings

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-08-01

Spectrally selective glazing is window glass that permits some portions of the solar spectrum to enter a building while blocking others. This high-performance glazing admits as much daylight as possible while preventing transmission of as much solar heat as possible. By controlling solar heat gains in summer, preventing loss of interior heat in winter, and allowing occupants to reduce electric lighting use by making maximum use of daylight, spectrally selective glazing significantly reduces building energy consumption and peak demand. Because new spectrally selective glazings can have a virtually clear appearance, they admit more daylight and permit much brighter, more open views to the outside while still providing the solar control of the dark, reflective energy-efficient glass of the past. This Federal Technology Alert provides detailed information and procedures for Federal energy managers to consider spectrally selective glazings. The principle of spectrally selective glazings is explained. Benefits related to energy efficiency and other architectural criteria are delineated. Guidelines are provided for appropriate application of spectrally selective glazing, and step-by-step instructions are given for estimating energy savings. Case studies are also presented to illustrate actual costs and energy savings. Current manufacturers, technology users, and references for further reading are included for users who have questions not fully addressed here.

Spectral functions from hadronic τ decays

International Nuclear Information System (INIS)

Davier, Michel

2002-01-01

Hadronic decays of the τ lepton provide a clean environment to study hadron dynamics in an energy regime dominated by romances, with the interesting information captured in the spectral functions. Recent results on exclusive channels are reviewed. Inclusive spectral functions are the basis for QCD analyses, delivering an accurate determination of the strong coupling constant and quantitative information on nonpertubative contributions. the τ vector spectral functions for the 2π and 4π final states are used together with e p+ e p- data in order to compute vacuum polarization integrals occurring in the calculations of the anomalous magnetic moment of the muon and the running of the electromagnetic coupling

Dark-Energy Equation-of-State parameter for high redshifts

International Nuclear Information System (INIS)

Montiel, Ariadna; Breton, Nora

2011-01-01

Since the elucidation of the nature of dark energy depends strongly on redshift observations, it is desirable to measure them over a wider range, but supernovae cannot be detected out past redshift 1.7. Gamma-ray-bursts (GRBs) offer means to extend the analysis to at least redshifts of > 6. The reason is that GRBs are visible across much larger distances than supernovae. GRBs are now known to have several light-curve and spectral properties from which the luminosity of the burst can be calculated, and it might GRBs become into standard candles. We have used data of 69 GRB to study the behavior of the parameter of the dark energy equation of state as a function of redshift.

Quantitative material decomposition using spectral computed tomography with an energy-resolved photon-counting detector

International Nuclear Information System (INIS)

Lee, Seungwan; Choi, Yu-Na; Kim, Hee-Joung

2014-01-01

Dual-energy computed tomography (CT) techniques have been used to decompose materials and characterize tissues according to their physical and chemical compositions. However, these techniques are hampered by the limitations of conventional x-ray detectors operated in charge integrating mode. Energy-resolved photon-counting detectors provide spectral information from polychromatic x-rays using multiple energy thresholds. These detectors allow simultaneous acquisition of data in different energy ranges without spectral overlap, resulting in more efficient material decomposition and quantification for dual-energy CT. In this study, a pre-reconstruction dual-energy CT technique based on volume conservation was proposed for three-material decomposition. The technique was combined with iterative reconstruction algorithms by using a ray-driven projector in order to improve the quality of decomposition images and reduce radiation dose. A spectral CT system equipped with a CZT-based photon-counting detector was used to implement the proposed dual-energy CT technique. We obtained dual-energy images of calibration and three-material phantoms consisting of low atomic number materials from the optimal energy bins determined by Monte Carlo simulations. The material decomposition process was accomplished by both the proposed and post-reconstruction dual-energy CT techniques. Linear regression and normalized root-mean-square error (NRMSE) analyses were performed to evaluate the quantitative accuracy of decomposition images. The calibration accuracy of the proposed dual-energy CT technique was higher than that of the post-reconstruction dual-energy CT technique, with fitted slopes of 0.97–1.01 and NRMSEs of 0.20–4.50% for all basis materials. In the three-material phantom study, the proposed dual-energy CT technique decreased the NRMSEs of measured volume fractions by factors of 0.17–0.28 compared to the post-reconstruction dual-energy CT technique. It was concluded that the

Spectroscopic and piezospectroscopic studies of the energy states of boron in silicon

International Nuclear Information System (INIS)

Lewis, R.A.; Fisher, P.; McLean, N.A.

1994-01-01

The p 3/2 optical absorption spectrum of boron impurity in silicon has been re-examined at high resolution. The precise transition energies measured agree with energies previously reported. In addition, energies for several previously unrecognised transitions are given as well as values for the absorption strengths and line widths. The measured transition energies and absorption strengths correlate very well with several recent calculations of binding energies and oscillator strengths, respectively. This excellent agreement between experiment and theory motivates a renumbering of the spectral lines which is not expected to require future modification. High-resolution piezospectroscopy of the p 3/2 series has also been undertaken. Small stresses were used to minimise the effect of interactions and permit accurate determination of the deformation potential constants. The deformation potential constants are found to be in fair agreement with previous experimental values and good agreement with recent theory. Experimental values for several of these are given for the first time, as are isotropic deformation potential constants of several excited states relative to the ground state. 58 refs., 14 figs

Some threshold spectral problems of Schroedinger operators

International Nuclear Information System (INIS)

Jia, X.

2009-01-01

This Ph.D. thesis deals with some spectral problems of the Schroedinger operators. We first consider the semi-classical limit of the number of bound states of unique two-cluster N-body Schroedinger operator. Then we use Dirichlet-Neumann bracket to get semi-classical limit of Riesz means of the discrete eigenvalues of N-body Schroedinger operator. The effective potential of N-body Schroedinger operator with Coulomb potential is also considered and we find that the effective potential has critical decay at infinity. Thus, the Schroedinger operator with critical potential is studied in this thesis. We study the coupling constant threshold of Schroedinger operator with critical potential and the asymptotic expansion of resolvent of Schroedinger operator with critical potential. We use that expansion to study low-energy asymptotics of derivative of spectral shift function for perturbation with critical decay. After that, we use this result and the known result for high-energy asymptotic expansion of spectral shift function to obtain the Levinson theorem. (author)

Regularized image denoising based on spectral gradient optimization

International Nuclear Information System (INIS)

Lukić, Tibor; Lindblad, Joakim; Sladoje, Nataša

2011-01-01

Image restoration methods, such as denoising, deblurring, inpainting, etc, are often based on the minimization of an appropriately defined energy function. We consider energy functions for image denoising which combine a quadratic data-fidelity term and a regularization term, where the properties of the latter are determined by a used potential function. Many potential functions are suggested for different purposes in the literature. We compare the denoising performance achieved by ten different potential functions. Several methods for efficient minimization of regularized energy functions exist. Most are only applicable to particular choices of potential functions, however. To enable a comparison of all the observed potential functions, we propose to minimize the objective function using a spectral gradient approach; spectral gradient methods put very weak restrictions on the used potential function. We present and evaluate the performance of one spectral conjugate gradient and one cyclic spectral gradient algorithm, and conclude from experiments that both are well suited for the task. We compare the performance with three total variation-based state-of-the-art methods for image denoising. From the empirical evaluation, we conclude that denoising using the Huber potential (for images degraded by higher levels of noise; signal-to-noise ratio below 10 dB) and the Geman and McClure potential (for less noisy images), in combination with the spectral conjugate gradient minimization algorithm, shows the overall best performance

Broadband spectrally dynamic solid state illumination source

Energy Technology Data Exchange (ETDEWEB)

Nicol, David B; Asghar, Ali; Gupta, Shalini; Kang, Hun; Pan, Ming [Georgia Institute of Technology, School of Electrical and Computer Engineering, Atlanta, GA 30332-0250 (United States); Strassburg, Martin [Georgia Institute of Technology, School of Electrical and Computer Engineering, Atlanta, GA 30332-0250 (United States); Georgia State University, Department of Physics and Astronomy, Atlanta, GA 30302-4106 (United States); Summers, Chris; Ferguson, Ian T [Georgia Institute of Technology, School of Materials Science and Engineering, Atlanta, GA 30332 (United States)

2006-06-15

Solid state lighting has done well recently in niche markets such as signage and displays, however, no available SSL technologies incorporate all the necessary attributes for general illumination. Development of a novel solid state general illumination source is discussed here. Two LEDs emitting at two distinct wavelengths can be monolithically grown and used to excite two or more phosphors with varied excitation spectra. The combined phosphorescence spectrum can then be controlled by adjusting the relative intensities of the two LED emissions. Preliminary phosphor analysis shows such a scheme to be viable for use in a spectrally dynamic broadband general illumination source. A tunnel junction is envisioned as a means of current spreading in a buried layer for three terminal operation. However, tunnel junction properties in GaN based materials are not well understood, and require further optimization to be practical devices. Preliminary results on GaN tunnel junctions are presented here as well. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Noncommutativity from spectral flow

Energy Technology Data Exchange (ETDEWEB)

Heinzl, Thomas; Ilderton, Anton [School of Mathematics and Statistics, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)

2007-07-27

We investigate the transition from second- to first-order systems. Quantum mechanically, this transforms configuration space into phase space and hence introduces noncommutativity in the former. This transition may be described in terms of spectral flow. Gaps in the energy or mass spectrum may become large which effectively truncates the available state space. Using both operator and path integral languages we explicitly discuss examples in quantum mechanics (light-front) quantum field theory and string theory.

A rediscussion of the atmospheric extinction and the absolute spectral-energy distribution of Vega

International Nuclear Information System (INIS)

Hayes, D.S.; Latham, D.W.

1975-01-01

For both the Lick and the Palomar calibrations of the spectral-energy distribution of Vega, the atmospheric extinction was treated incorrectly. We present a model for extinction in the Earth's atmosphere and use this model to calculate corrections to the Lick and Palomar calibrations. We also describe a method that can be used to fabricate mean extinction coefficients for any mountain observatory. We combine selected portions of the corrected Lick and corrected Palomar calibrations with the new Mount Hopkins calibration to generate an absolute spectral-energy distibution of Vega over the wavelength range 3300--10,800 A. Until better measurements become available, we recommend the use of this calibration for all practical applications

X-ray spectral study of the Th6p,5f electron states in ThO2 and ThF4

International Nuclear Information System (INIS)

Teterin, Y.A.; Nikitin, A.S.; Teterin, A.Y.; Ivanov, K.E.; Utkin, I.O.; Nerehov, V.A.; Ryzhkov, M.V.; Vukchevich, I.J.

2002-01-01

The study of the Th6p,5f electron states in Th, ThO 2 and ThF was carried out on the basis of the X-ray photoelectron fine spectral structure parameters in the binding energy range of 0-∼ 1000 eV, X-ray O 4,5 (Th) emission spectra of the shallow (0-∼50 eV) electrons and results of theoretical calculations. As a result, despite the absence of the Th5f electrons in thorium atoms, the Th5f atomic orbitals were established to participate in the formation of molecular orbitals in thorium dioxide and tetrafluoride. In the MO LCAO approximation this allowed to suggest the possible existence of filled Th5f electronic states in thorium compounds. On the basis of the X-ray O 4,5 (Th) emission spectral structure parameters the effective formation of the inner valence molecular orbitals in the studied compounds was confirmed. (authors)

Time evolution of the spectral break in the high-energy extra component of GRB 090926A

Science.gov (United States)

Yassine, M.; Piron, F.; Mochkovitch, R.; Daigne, F.

2017-10-01

Aims: The prompt light curve of the long GRB 090926A reveals a short pulse 10 s after the beginning of the burst emission, which has been observed by the Fermi observatory from the keV to the GeV energy domain. During this bright spike, the high-energy emission from GRB 090926A underwent a sudden hardening above 10 MeV in the form of an additional power-law component exhibiting a spectral attenuation at a few hundreds of MeV. This high-energy break has been previously interpreted in terms of gamma-ray opacity to pair creation and has been used to estimate the bulk Lorentz factor of the outflow. In this article, we report on a new time-resolved analysis of the GRB 090926A broadband spectrum during its prompt phase and on its interpretation in the framework of prompt emission models. Methods: We characterized the emission from GRB 090926A at the highest energies with Pass 8 data from the Fermi Large Area Telescope (LAT), which offer a greater sensitivity than any data set used in previous studies of this burst, particularly in the 30-100 MeV energy band. Then, we combined the LAT data with the Fermi Gamma-ray Burst Monitor (GBM) in joint spectral fits to characterize the time evolution of the broadband spectrum from keV to GeV energies. We paid careful attention to the systematic effects that arise from the uncertainties on the LAT response. Finally, we performed a temporal analysis of the light curves and we computed the variability timescales from keV to GeV energies during and after the bright spike. Results: Our analysis confirms and better constrains the spectral break, which has been previously reported during the bright spike. Furthermore, it reveals that the spectral attenuation persists at later times with an increase of the break characteristic energy up to the GeV domain until the end of the prompt phase. We discuss these results in terms of keV-MeV synchroton radiation of electrons accelerated during the dissipation of the jet energy and inverse Compton

The ground state tunneling splitting and the zero point energy of malonaldehyde: a quantum Monte Carlo determination.

Science.gov (United States)

Viel, Alexandra; Coutinho-Neto, Maurício D; Manthe, Uwe

2007-01-14

Quantum dynamics calculations of the ground state tunneling splitting and of the zero point energy of malonaldehyde on the full dimensional potential energy surface proposed by Yagi et al. [J. Chem. Phys. 1154, 10647 (2001)] are reported. The exact diffusion Monte Carlo and the projection operator imaginary time spectral evolution methods are used to compute accurate benchmark results for this 21-dimensional ab initio potential energy surface. A tunneling splitting of 25.7+/-0.3 cm-1 is obtained, and the vibrational ground state energy is found to be 15 122+/-4 cm-1. Isotopic substitution of the tunneling hydrogen modifies the tunneling splitting down to 3.21+/-0.09 cm-1 and the vibrational ground state energy to 14 385+/-2 cm-1. The computed tunneling splittings are slightly higher than the experimental values as expected from the potential energy surface which slightly underestimates the barrier height, and they are slightly lower than the results from the instanton theory obtained using the same potential energy surface.

Understanding the Long-Term Spectral Variability of Cygnus X-1 from BATSE and ASM Observations

Science.gov (United States)

Zdziarski, Andrzej A.; Poutanen, Juri; Paciesas, William S.; Wen, Linqing; Six, N. Frank (Technical Monitor)

2002-01-01

We present a spectral analysis of observations of Cygnus X-1 by the RXTE/ASM (1.5-12 keV) and CGRO/BATSE (20-300 keV), including about 1200 days of simultaneous data. We find a number of correlations between intensities and hardnesses in different energy bands from 1.5 keV to 300 keV. In the hard (low) spectral state, there is a negative correlation between the ASM 1.5-12 keV flux and the hardness at any energy. In the soft (high) spectral state, the ASM flux is positively correlated with the ASM hardness (as previously reported) but uncorrelated with the BATSE hardness. In both spectral states, the BATSE hardness correlates with the flux above 100 keV, while it shows no correlation with the flux in the 20-100 keV range. At the same time, there is clear correlation between the BATSE fluxes below and above 100 keV. In the hard state, most of the variability can be explained by softening the overall spectrum with a pivot at approximately 50 keV. The observations show that there has to be another, independent variability pattern of lower amplitude where the spectral shape does not change when the luminosity changes. In the soft state, the variability is mostly caused by a variable hard (Comptonized) spectral component of a constant shape superimposed on a constant soft blackbody component. These variability patterns are in agreement with the dependence of the rms variability on the photon energy in the two states. We interpret the observed correlations in terms of theoretical Comptonization models. In the hard state, the variability appears to be driven mostly by changing flux in seed photons Comptonized in a hot thermal plasma cloud with an approximately constant power supply. In the soft state, the variability is consistent with flares of hybrid, thermal/nonthermal, plasma with variable power above a stable cold disk. Also, based on broadband pointed observations simultaneous with those of the ASM and BATSE, we find the intrinsic bolometric luminosity increases by a

Study of the spectral and energy characteristics of lasing in the green spectral region by lithium fluoride with radiation color centers

Energy Technology Data Exchange (ETDEWEB)

Voitovich, A.P.; Kalinov, V.S.; Mikhnov, S.A.; Ovseichuk, S.I.

1987-06-01

The spectral and energy characteristics of lasers utilizing lithium fluoride with F2 and F3(+) color centers in transverse and longitudinal pumping schemes are studied. The feasibility of obtaining stable narrow-band radiation in the 510-570 nm range using a selective resonator is demonstrated. Consideration is given to the effect of lithium-fluoride crystal processing by excimer laser radiation at a wavelength of 308 nm on the spectroscopic and lasing characteristics of the F3(+) color center. After this processing, the laser efficiency in the green spectral region increases by more than a factor of two (reaching an efficiency of 14 percent). 7 references.

Maximizing the spectral and energy efficiency of ARQ with a fixed outage probability

KAUST Repository

Hadjtaieb, Amir; Chelli, Ali; Alouini, Mohamed-Slim

2015-01-01

This paper studies the spectral and energy efficiency of automatic repeat request (ARQ) in Nakagami-m block-fading channels. The source encodes each packet into L similar sequences and transmits them to the destination in the L subsequent time slots

Coexistence of a bound state and scattering at the same energy value: a quantum paradox

International Nuclear Information System (INIS)

Chabanov, V.M.; Zakhar'ev, B.N.

1998-01-01

The example of a multi-channel system which possesses both bound (not quasi-bound !) and scattering states at the same energy value E is demonstrated. A special interaction has ability to confine waves near the origin and simultaneously admit scattering (even with transparency) at the fixed spectral point. These interaction matrices and wave functions can be continued to the whole axis. As another multi-channel peculiarity having no one-channel analogues was found a class of absolutely transparent interaction matrices without bound states

Virtual Non-Contrast CT Using Dual-Energy Spectral CT: Feasibility of Coronary Artery Calcium Scoring

OpenAIRE

Song, Inyoung; Yi, Jeong Geun; Park, Jeong Hee; Kim, Sung Mok; Lee, Kyung Soo; Chung, Myung Jin

2016-01-01

Objective To evaluate the feasibility of coronary artery calcium scoring based on three virtual noncontrast-enhanced (VNC) images derived from single-source spectral dual-energy CT (DECT) as compared with true noncontrast-enhanced (TNC) images. Materials and Methods This prospective study was conducted with the approval of our Institutional Review Board. Ninety-seven patients underwent noncontrast CT followed by contrast-enhanced chest CT using single-source spectral DECT. Iodine eliminated V...

Maximizing the spectral and energy efficiency of ARQ with a fixed outage probability

KAUST Repository

Hadjtaieb, Amir

2015-10-05

This paper studies the spectral and energy efficiency of automatic repeat request (ARQ) in Nakagami-m block-fading channels. The source encodes each packet into L similar sequences and transmits them to the destination in the L subsequent time slots. The destination combines the L sequences using maximal ratio combining and tries to decode the information. In case of decoding failure, the destination feeds back a negative acknowledgment and then the source sends the same L sequences to the destination. This process continues until successful decoding occurs at the destination with no limit on the number of retransmissions. We consider two optimization problems. In the first problem, we maximize the spectral efficiency of the system with respect to the rate for a fixed power. In the second problem, we maximize the energy efficiency with respect to the transmitted power for a fixed rate. © 2015 IEEE.

Enhancing inhibition-induced plasticity in tinnitus--spectral energy contrasts in tailor-made notched music matter.

Directory of Open Access Journals (Sweden)

Alwina Stein

Full Text Available Chronic tinnitus seems to be caused by reduced inhibition among frequency selective neurons in the auditory cortex. One possibility to reduce tinnitus perception is to induce inhibition onto over-activated neurons representing the tinnitus frequency via tailor-made notched music (TMNM. Since lateral inhibition is modifiable by spectral energy contrasts, the question arises if the effects of inhibition-induced plasticity can be enhanced by introducing increased spectral energy contrasts (ISEC in TMNM. Eighteen participants suffering from chronic tonal tinnitus, pseudo randomly assigned to either a classical TMNM or an ISEC-TMNM group, listened to notched music for three hours on three consecutive days. The music was filtered for both groups by introducing a notch filter centered at the individual tinnitus frequency. For the ISEC-TMNM group a frequency bandwidth of 3/8 octaves on each side of the notch was amplified, additionally, by about 20 dB. Before and after each music exposure, participants rated their subjectively perceived tinnitus loudness on a visual analog scale. During the magnetoencephalographic recordings, participants were stimulated with either a reference tone of 500 Hz or a test tone with a carrier frequency representing the individual tinnitus pitch. Perceived tinnitus loudness was significantly reduced after TMNM exposure, though TMNM type did not influence the loudness ratings. Tinnitus related neural activity in the N1m time window and in the so called tinnitus network comprising temporal, parietal and frontal regions was reduced after TMNM exposure. The ISEC-TMNM group revealed even enhanced inhibition-induced plasticity in a temporal and a frontal cortical area. Overall, inhibition of tinnitus related neural activity could be strengthened in people affected with tinnitus by increasing spectral energy contrast in TMNM, confirming the concepts of inhibition-induced plasticity via TMNM and spectral energy contrasts.

Quantitative analysis of the dual-energy CT virtual spectral curve for focal liver lesions characterization

Energy Technology Data Exchange (ETDEWEB)

Wang, Qi, E-mail: wq20@hotmail.com; Shi, Gaofeng, E-mail: gaofengs62@sina.com; Qi, Xiaohui, E-mail: qixiaohui1984@163.com; Fan, Xueli, E-mail: 407849960@qq.com; Wang, Lijia, E-mail: 893197597@qq.com

2014-10-15

Highlights: • We establish a feasible method using the virtual spectral curves (VSC) to differentiate focal liver lesions using DECT. • Our study shows the slope of the VSC can be used to differentiate between hemangioma, HCC, metastasis and cyst. • Importantly, the diagnostic specificities associated with using the slope to diagnose both hemangioma and cysts were 100%. - Abstract: Objective: To assess the usefulness of the spectral curve slope of dual-energy CT (DECT) for differentiating between hepatocellular carcinoma (HCC), hepatic metastasis, hemangioma (HH) and cysts. Methods: In total, 121 patients were imaged in the portal venous phase using dual-energy mode. Of these patients, 23 patients had HH, 28 patients had HCC, 40 patients had metastases and 30 patients had simple cysts. The spectral curves of the hepatic lesions were derived from the 40–190 keV levels of virtual monochromatic spectral imaging. The spectral curve slopes were calculated from 40 to 110 keV. The slopes were compared using the Kruskal–Wallis test. Receiver operating characteristic curves (ROC) were used to determine the optimal cut-off value of the slope of the spectral curve to differentiate between the lesions. Results: The spectral curves of the four lesion types had different baseline levels. The HH baseline level was the highest followed by HCC, metastases and cysts. The slopes of the spectral curves of HH, HCC, metastases and cysts were 3.81 ± 1.19, 1.49 ± 0.57, 1.06 ± 0.76 and 0.13 ± 0.17, respectively. These values were significantly different (P < 0.008). Based on ROC analysis, the respective diagnostic sensitivity and specificity were 87% and 100% for hemangioma (cut-off value ≥ 2.988), 82.1% and 65.9% for HCC (cut-off value 1.167–2.998), 65.9% and 59% for metastasis (cut-off value 0.133–1.167) and 44.4% and 100% for cysts (cut-off value ≤ 0.133). Conclusion: Quantitative analysis of the DECT spectral curve in the portal venous phase can be used to

A mass and energy conserving spectral element atmospheric dynamical core on the cubed-sphere grid

International Nuclear Information System (INIS)

Taylor, M A; Edwards, J; Thomas, S; Nair, R

2007-01-01

We present results from a conservative formulation of the spectral element method applied to global atmospheric circulation modeling. Exact local conservation of both mass and energy is obtained via a new compatible formulation of the spectral element method. Compatibility insures that the key integral property of the divergence and gradient operators required to show conservation also hold in discrete form. The spectral element method is used on a cubed-sphere grid to discretize the horizontal directions on the sphere. It can be coupled to any conservative vertical/radial discretization. The accuracy and conservation properties of the method are illustrated using a baroclinic instability test case

The energy and spectral characteristics of a room-temperature pulsed laser on a ZnS:Fe2+ polycrystal

Science.gov (United States)

Firsov, K. N.; Gavrishchuk, E. M.; Ikonnikov, V. B.; Kazantsev, S. Yu; Kononov, I. G.; Kotereva, T. V.; Savin, D. V.; Timofeeva, N. A.

2016-04-01

The energy and spectral characteristics of a laser on a ZnS:Fe2+ polycrystal operating at room temperature have been studied. The laser was pumped by a non-chain electro-discharge HF laser with a full-width at half-maximum pulse duration of ~140 ns. The diameter of the pumping radiation spot on the crystal surface was 3.8& mm. The two-sided diffuse doping of a polycrystalline CVD-ZnS sample with the surfaces preliminarily coated by high-purity iron films was performed in the process of hot isostatic pressing (HIP) in an argon atmosphere at a pressure of 100 MPa and temperature of 1290 °C. Increasing the duration of the HIP treatment from 54 h to 72 h made it possible to obtain twice the doping depth, and correspondingly, twice the length of active medium. As a result, the slope laser efficiency with respect to the absorbed energy was raised by a factor of 1.75 as compared to the value obtained in our earlier work with a polycrystalline sample. The generation energy was 25 mJ at a slope efficiency of ηslope = 35%. It was established that the generation spectra of the laser with a non-selective resonator have a linear structure with intervals between the neighboring lines of δλ 6 ÷ 8 nm, which is spurious for solid-state lasers. The spectral structure observed is not related to the elements inside the resonator, which might form Fabry-Perot interferometers.

State Energy Program Fact Sheet

Energy Technology Data Exchange (ETDEWEB)

None

2018-02-01

The U.S. Department of Energy’s State Energy Program (SEP) provides funding and technical assistance to states, territories, and the District of Columbia to enhance energy security, advance state-led energy initiatives, and maximize the benefits of decreasing energy waste.

State Energy Program Operations Manual

Energy Technology Data Exchange (ETDEWEB)

Office of Building Technology, State and Community Programs

1999-03-17

The State Energy Program Operations Manual is a reference tool for the states and the program officials at the U.S. Department of Energy's Office of Building Technology, State and Community Programs and Regional Support Offices as well as State Energy Offices. The Manual contains information needed to apply for and administer the State Energy Program, including program history, application rules and requirements, and program administration and monitoring requirements.

Planck intermediate results: XLIII. Spectral energy distribution of dust in clusters of galaxies

DEFF Research Database (Denmark)

Adam, R.; Ade, P. A R; Aghanim, N.

2016-01-01

Although infrared (IR) overall dust emission from clusters of galaxies has been statistically detected using data from the Infrared Astronomical Satellite (IRAS), it has not been possible to sample the spectral energy distribution (SED) of this emission over its peak, and thus to break the degene...

A study on spectral energy for the end of the twentieth century the basis of the NCEP reanalysis-II

Science.gov (United States)

Aranha, A. F.; Veiga, J. A.; Yoshida, M. C.

2013-05-01

The energy cycle proposed by Lorenz (1955) is composed of the behavior of the average energy from the atmosphere and characteristics of atmospheric energy deviations from this average, respectively called basic state and perturbed state. However, it is possible to discretize the energy contained in the atmosphere disturbed state, decomposing the fields of the various disturbances or harmonics wave type, so as to measure and analyze the energy of these disorders according to their number or wavelength, this methodology described second Saltzman (1957). Therefore, in view of the spectral analysis as a methodological basis, this work aims to study the energy contained by the atmosphere in disturbed state. Considering the terms of power generation potential available for nth waves due to diabatic heating, represented by (G(n)), potential energy of nth wave (P(n)) and kinetic energy of nth wave (K(n)) and the conversion of energy between the energy nth kinetic and potential energy of waves nth waves given by (C(n)). The variables used in the calculation of the terms above are, temperature (T) orthogonal components of the wind (u, v, w) and geopotential height (G) from a data set from the National Center for Environmental Prediction (NCEP) considering daily shared values on a regular grid with a spatial resolution of 2.5° × 2.5°, distributed in 12 pressure levels (1000, 925, 850, 700, 600, 500, 400, 300, 250, 200, 150, 100 hPa ) for the 1970 to 1999 period. The results show that for kinetic energy of disturbance to nth wave, the amount of energy is somewhat dammed during for the first 10 wave numbers in this range are the planetary waves and waves. Observing this way, we can conclude that these waves are responsible for much of the kinetic energy in disturbed state. A characteristic and a difference in the distribution of energy between kinetic energy and potential energy disturbed total available to disturbance, is the derivative of the energy wavenumber presented by

Spectral and Timing States in Black Hole Binaries

Science.gov (United States)

Wilms, J.

Results on the long term variability of galactic black hole candidates are reviewed. I mainly present the results of a > 2 year long campaign with RXTE to monitor the canonical soft state black hole candidates LMC X-1 and LMC X-3 using monthly observations. These observations are presented within the context of the RXTE-ASM long term quasi-periodic variability on timescales of about 150d. For LMC X-3, times of low ASM count rate are correlated with a significant hardening of the X-ray spectrum. The observation with the lowest flux during the whole monitoring campaign can be modeled with a simple γ=1.7 power law -- a hard state spectrum. Since these spectral hardenings occur on the 150 d timescale it is probable that they are associated with periodic changes in the accretion rate. Possible causes for this behavior are discussed, e.g. a wind driven limit-cycle or long-term variability of the donor star.

Ground-state energy of an exciton-(LO) phonon system in a parabolic quantum well

Science.gov (United States)

Gerlach, B.; Wüsthoff, J.; Smondyrev, M. A.

1999-12-01

This paper presents a variational study of the ground-state energy of an exciton-(LO) phonon system, which is spatially confined to a quantum well. The exciton-phonon interaction is of Fröhlich type, the confinement potentials are assumed to be parabolic functions of the coordinates. Making use of functional integral techniques, the phonon part of the problem can be eliminated exactly, leading us to an effective two-particle system, which has the same spectral properties as the original one. Subsequently, Jensen's inequality is applied to obtain an upper bound on the ground-state energy. The main intention of this paper is to analyze the influence of the quantum-well-induced localization of the exciton on its ground-state energy (or its binding energy, respectively). To do so, we neglect any mismatch of the masses or the dielectric constants, but admit an arbitrary strength of the confinement potentials. Our approach allows for a smooth interpolation of the ultimate limits of vanishing and infinite confinement, corresponding to the cases of a free three-dimensional and a free two-dimensional exciton-phonon system. The interpolation formula for the ground-state energy bound corresponds to similar formulas for the free polaron or the free exciton-phonon system. These bounds in turn are known to compare favorably with all previous ones, which we are aware of.

Development of a modular directional and spectral neutron detection system using solid-state detectors

Energy Technology Data Exchange (ETDEWEB)

Weltz, A., E-mail: weltza3@gmail.com; Torres, B.; McElwain, L.; Dahal, R.; Huang, J.; Bhat, I.; Lu, J.; Danon, Y.

2015-08-21

A detection system using room-temperature, microstructured solid-state thermal neutron detectors with very low leakage current has been developed at Rensselaer Polytechnic Institute (RPI) with the ability to provide positional and spectral information about an unknown neutron source. The Directional and Spectral Neutron Detection System (DSNDS) utilizes a set of small-but-scalable, zero-bias solid-state thermal neutron detectors which have demonstrated high thermal neutron efficiency and adequate gamma insensitivity. The DSNDS can gather spectral information about an unknown neutron source with a relatively small number of detectors, simplifying the detector electronics and minimizing cost; however, the DSNDS is modular in design, providing the capability to increase the detection efficiency and angular resolution. The system used in this paper was comprised of a stack of five high-density polyethylene (HDPE) disks with a thickness of 5 cm and a diameter of 30 cm, the middle disk containing 16 detectors positioned as one internal (moderated) and one external (unmoderated) ring of solid-state neutron detectors. These two detector rings provide the ability to determine the directionality of a neutron source. The system gathers spectral information about a neutron source in two ways: by measuring the relative responses of the internal ring of detectors as well as measuring the ratio of the internal-to-external detector responses. Experiments were performed with variable neutron spectra: a {sup 252}Cf spontaneous fission neutron source which was HDPE moderated, HDPE reflected, lead (Pb) shielded, and bare in order to benchmark the system for spectral sensitivity. Simulations were performed in order to characterize the neutron spectra corresponding to each of the source configurations and showed agreement with experimental measurements. The DSNDS demonstrates the ability to determine the relative angle of the source and the hardness of the neutron spectrum. By using the

Energy-Looping Nanoparticles: Harnessing Excited-State Absorption for Deep-Tissue Imaging.

Science.gov (United States)

Levy, Elizabeth S; Tajon, Cheryl A; Bischof, Thomas S; Iafrati, Jillian; Fernandez-Bravo, Angel; Garfield, David J; Chamanzar, Maysamreza; Maharbiz, Michel M; Sohal, Vikaas S; Schuck, P James; Cohen, Bruce E; Chan, Emory M

2016-09-27

Near infrared (NIR) microscopy enables noninvasive imaging in tissue, particularly in the NIR-II spectral range (1000-1400 nm) where attenuation due to tissue scattering and absorption is minimized. Lanthanide-doped upconverting nanocrystals are promising deep-tissue imaging probes due to their photostable emission in the visible and NIR, but these materials are not efficiently excited at NIR-II wavelengths due to the dearth of lanthanide ground-state absorption transitions in this window. Here, we develop a class of lanthanide-doped imaging probes that harness an energy-looping mechanism that facilitates excitation at NIR-II wavelengths, such as 1064 nm, that are resonant with excited-state absorption transitions but not ground-state absorption. Using computational methods and combinatorial screening, we have identified Tm(3+)-doped NaYF4 nanoparticles as efficient looping systems that emit at 800 nm under continuous-wave excitation at 1064 nm. Using this benign excitation with standard confocal microscopy, energy-looping nanoparticles (ELNPs) are imaged in cultured mammalian cells and through brain tissue without autofluorescence. The 1 mm imaging depths and 2 μm feature sizes are comparable to those demonstrated by state-of-the-art multiphoton techniques, illustrating that ELNPs are a promising class of NIR probes for high-fidelity visualization in cells and tissue.

Single-particle spectroscopy of I-III-VI semiconductor nanocrystals: spectral diffusion and suppression of blinking by two-color excitation.

Science.gov (United States)

Sharma, Dharmendar Kumar; Hirata, Shuzo; Bujak, Lukasz; Biju, Vasudevanpillai; Kameyama, Tatsuya; Kishi, Marino; Torimoto, Tsukasa; Vacha, Martin

2016-07-14

Ternary I-III-VI semiconductor nanocrystals have been explored as non-toxic alternatives to II-VI semiconductors for optoelectronic and sensing applications, but large photoluminescence spectral width and moderate brightness restrict their practical use. Here, using single-particle photoluminescence spectroscopy on nanocrystals of (AgIn)xZn2(1-x)S2 we show that the photoluminescence band is inhomogeneously broadened and that size distribution is the dominant factor in the broadening. The residual homogeneous linewidth of individual nanocrystals reaches up to 75% of the ensemble spectral width. Single nanocrystals undergo spectral diffusion which also contributes to the inhomogeneous band. Excitation with two lasers with energies above and below the bandgap reveals coexistence of two emitting donor states within one particle. Spectral diffusion in such particles is due to temporal activation and deactivation of one such state. Filling of a trap state with a lower-energy laser enables optical modulation of photoluminescence intermittency (blinking) and leads to an almost two-fold increase in brightness.

ON NEUTRAL ABSORPTION AND SPECTRAL EVOLUTION IN X-RAY BINARIES

International Nuclear Information System (INIS)

Miller, J. M.; Cackett, E. M.; Reis, R. C.

2009-01-01

Current X-ray observatories make it possible to follow the evolution of transient and variable X-ray binaries across a broad range in luminosity and source behavior. In such studies, it can be unclear whether evolution in the low-energy portion of the spectrum should be attributed to evolution in the source, or instead to evolution in neutral photoelectric absorption. Dispersive spectrometers make it possible to address this problem. We have analyzed a small but diverse set of X-ray binaries observed with the Chandra High Energy Transmission Grating Spectrometer across a range in luminosity and different spectral states. The column density in individual photoelectric absorption edges remains constant with luminosity, both within and across source spectral states. This finding suggests that absorption in the interstellar medium strongly dominates the neutral column density observed in spectra of X-ray binaries. Consequently, evolution in the low-energy spectrum of X-ray binaries should properly be attributed to evolution in the source spectrum. We discuss our results in the context of X-ray binary spectroscopy with current and future X-ray missions.

Rayleigh imaging in spectral mammography

Science.gov (United States)

Berggren, Karl; Danielsson, Mats; Fredenberg, Erik

2016-03-01

Spectral imaging is the acquisition of multiple images of an object at different energy spectra. In mammography, dual-energy imaging (spectral imaging with two energy levels) has been investigated for several applications, in particular material decomposition, which allows for quantitative analysis of breast composition and quantitative contrast-enhanced imaging. Material decomposition with dual-energy imaging is based on the assumption that there are two dominant photon interaction effects that determine linear attenuation: the photoelectric effect and Compton scattering. This assumption limits the number of basis materials, i.e. the number of materials that are possible to differentiate between, to two. However, Rayleigh scattering may account for more than 10% of the linear attenuation in the mammography energy range. In this work, we show that a modified version of a scanning multi-slit spectral photon-counting mammography system is able to acquire three images at different spectra and can be used for triple-energy imaging. We further show that triple-energy imaging in combination with the efficient scatter rejection of the system enables measurement of Rayleigh scattering, which adds an additional energy dependency to the linear attenuation and enables material decomposition with three basis materials. Three available basis materials have the potential to improve virtually all applications of spectral imaging.

Steady-state emission of blazars at very high energies

Energy Technology Data Exchange (ETDEWEB)

Hoehne-Moench, Daniel

2010-07-01

One key scientific program of the MAGIC telescope project is the discovery and detection of blazars. They constitute the most prominent extragalactic source class in the very high energy (VHE) {gamma}-ray regime with 29 out of 34 known objects. Therefore a major part of the available observation time was spent in the last years on high-frequency peaked blazars. The selection criteria were chosen to increase the detection probability. As the X-ray flux is believed to be correlated to the VHE {gamma}-ray flux, only X-ray selected sources with a flux F{sub X}>2 {mu}Jy at 1 keV were considered. To avoid strong attenuation of the -rays in the extragalactic infrared background, the redshift was restricted to values between z<0.15 and z<0.4, depending on the declination of the objects. The latter determines the zenith distance during culmination which should not exceed 30 (for z<0.4) and 45 (for z<0.15), respectively. Between August 2005 and April 2009, a sample of 24 X-ray selected high-frequency peaked blazars has been observed with the MAGIC telescope. Three of them were detected including 1ES 1218+304 being the first high-frequency peaked BL Lacertae object (HBL) to be discovered with MAGIC in VHE {gamma}-rays. One previously detected object was not confirmed as VHE emitter in this campaign by MAGIC. A set of 20 blazars previously not detected is treated more closely in this work. In this campaign, during almost four years {proportional_to}450 hrs or {proportional_to}22% of the available observation time for extragalactic objects were dedicated to investigate the baseline emission of blazars and their broadband spectral properties in this emission state. For the sample of 20 objects in a redshift range of 0.018

Determination of the electron-hole pair creation energy for semiconductors from the spectral responsivity of photodiodes

CERN Document Server

Scholze, F; Kuschnerus, P; Rabus, H; Richter, M; Ulm, G

2000-01-01

Ionizing radiation can be detected by the measurement of the charge carriers produced in a detector. The improved semiconductor technology now allows detectors operating near the physical limits of the detector materials to be designed. The mean energy required for producing an electron-hole pair, W, is a material property of the semiconductor. Here, the determination of W from the spectral responsivity of photodiodes is demonstrated. Using spectrally dispersed synchrotron radiation, different types of semiconductor photodiodes have been examined in the UV-, VUV-, and soft X-ray spectral range. Their spectral responsivity was determined with relative uncertainties between 0.4% and 1% using a cryogenic electrical-substitution radiometer as primary detector standard. Results are presented for silicon n-on-p junction photodiodes and for GaAsP/Au Schottky diodes at room temperature. The investigations for silicon covered the complete spectral range from 3 to 1500 eV, yielding a constant value W=(3.66+-0.03) eV fo...

IDEN2-A program for visual identification of spectral lines and energy levels in optical spectra of atoms and simple molecules

Science.gov (United States)

Azarov, V. I.; Kramida, A.; Vokhmentsev, M. Ya.

2018-04-01

The article describes a Java program that can be used in a user-friendly way to visually identify spectral lines observed in complex spectra with theoretically predicted transitions between atomic or molecular energy levels. The program arranges various information about spectral lines and energy levels in such a way that line identification and determination of positions of experimentally observed energy levels become much easier tasks that can be solved fast and efficiently.

Optimal Monochromatic Energy Levels in Spectral CT Pulmonary Angiography for the Evaluation of Pulmonary Embolism

Science.gov (United States)

Wu, Huawei; Zhang, Qing; Hua, Jia; Hua, Xiaolan; Xu, Jianrong

2013-01-01

Background The aim of this study was to determine the optimal monochromatic spectral CT pulmonary angiography (sCTPA) levels to obtain the highest image quality and diagnostic confidence for pulmonary embolism detection. Methods The Institutional Review Board of the Shanghai Jiao Tong University School of Medicine approved this study, and written informed consent was obtained from all participating patients. Seventy-two patients with pulmonary embolism were scanned with spectral CT mode in the arterial phase. One hundred and one sets of virtual monochromatic spectral (VMS) images were generated ranging from 40 keV to 140 keV. Image noise, clot diameter and clot to artery contrast-to-noise ratio (CNR) from seven sets of VMS images at selected monochromatic levels in sCTPA were measured and compared. Subjective image quality and diagnostic confidence for these images were also assessed and compared. Data were analyzed by paired t test and Wilcoxon rank sum test. Results The lowest noise and the highest image quality score for the VMS images were obtained at 65 keV. The VMS images at 65 keV also had the second highest CNR value behind that of 50 keV VMS images. There was no difference in the mean noise and CNR between the 65 keV and 70 keV VMS images. The apparent clot diameter correlated with the keV levels. Conclusions The optimal energy level for detecting pulmonary embolism using dual-energy spectral CT pulmonary angiography was 65–70 keV. Virtual monochromatic spectral images at approximately 65–70 keV yielded the lowest image noise, high CNR and highest diagnostic confidence for the detection of pulmonary embolism. PMID:23667583

Unveiling the excited state energy transfer pathways in peridinin-chlorophyll a-protein by ultrafast multi-pulse transient absorption spectroscopy.

Science.gov (United States)

Redeckas, Kipras; Voiciuk, Vladislava; Zigmantas, Donatas; Hiller, Roger G; Vengris, Mikas

2017-04-01

Time-resolved multi-pulse methods were applied to investigate the excited state dynamics, the interstate couplings, and the excited state energy transfer pathways between the light-harvesting pigments in peridinin-chlorophyll a-protein (PCP). The utilized pump-dump-probe techniques are based on perturbation of the regular PCP energy transfer pathway. The PCP complexes were initially excited with an ultrashort pulse, resonant to the S 0 →S 2 transition of the carotenoid peridinin. A portion of the peridinin-based emissive intramolecular charge transfer (ICT) state was then depopulated by applying an ultrashort NIR pulse that perturbed the interaction between S 1 and ICT states and the energy flow from the carotenoids to the chlorophylls. The presented data indicate that the peridinin S 1 and ICT states are spectrally distinct and coexist in an excited state equilibrium in the PCP complex. Moreover, numeric analysis of the experimental data asserts ICT→Chl-a as the main energy transfer pathway in the photoexcited PCP systems. Copyright © 2017 Elsevier B.V. All rights reserved.

High-energy observations of the state transition of the X-ray nova and black hole candidate XTE J1720-318

DEFF Research Database (Denmark)

Bel, M.C.; Rodriguez, J.; Sizun, P.

2004-01-01

We report the results of extensive high-energy observations of the X-ray transient and black hole candidate XTE J1720-318 performed with INTEGRAL, XMM-Newton and RXTE. The source, which underwent an X-ray outburst in 2003 January, was observed in February in a spectral state dominated by a soft......, typical of a black-hole binary in the so-called High/Soft State. We then followed the evolution of the source outburst over several months using the INTEGRAL Galactic Centre survey observations. The source became active again at the end of March: it showed a clear transition towards a much harder state...... of the black hole X-ray novae class which populate our galactic bulge and we discuss its properties in the frame of the spectral models used for transient black hole binaries....

Hadronic spectral functions in nuclear matter

International Nuclear Information System (INIS)

Post, M.; Leupold, S.; Mosel, U.

2004-01-01

We study the in-medium properties of mesons (π,η,ρ) and baryon resonances in cold nuclear matter within a coupled-channel analysis. The meson self energies are generated by particle-hole excitations. Thus multi-peak spectra are obtained for the mesonic spectral functions. In turn this leads to medium-modifications of the baryon resonances. Special care is taken to respect the analyticity of the spectral functions and to take into account effects from short-range correlations both for positive and negative parity states. Our model produces sensible results for pion and Δ dynamics in nuclear matter. We find a strong interplay of the ρ meson and the D 13 (1520), which moves spectral strength of the ρ spectrum to smaller invariant masses and leads to a broadening of the baryon resonance. The optical potential for the η meson resulting from our model is rather attractive whereas the in-medium properties modifications of the S 11 (1535) are found to be quite small

Utilize the spectral line pair of the same ionized state ion to measure the ion temperature of tokamak plasma

International Nuclear Information System (INIS)

Lin Xiaodong

2000-01-01

Making use of a Fabry-Perot interferometer driven by a piezoelectric crystal and selecting the suitable separation of plates, the ion temperature is defined by measuring the superimposed profile of the spectral line pair of the same ionized state ions in Tokamak. The advantage of this method is to higher spectral resolution and wider spectral range select

Optimal and robust control of quantum state transfer by shaping the spectral phase of ultrafast laser pulses.

Science.gov (United States)

Guo, Yu; Dong, Daoyi; Shu, Chuan-Cun

2018-04-04

Achieving fast and efficient quantum state transfer is a fundamental task in physics, chemistry and quantum information science. However, the successful implementation of the perfect quantum state transfer also requires robustness under practically inevitable perturbative defects. Here, we demonstrate how an optimal and robust quantum state transfer can be achieved by shaping the spectral phase of an ultrafast laser pulse in the framework of frequency domain quantum optimal control theory. Our numerical simulations of the single dibenzoterrylene molecule as well as in atomic rubidium show that optimal and robust quantum state transfer via spectral phase modulated laser pulses can be achieved by incorporating a filtering function of the frequency into the optimization algorithm, which in turn has potential applications for ultrafast robust control of photochemical reactions.

The transition between energy efficient and energy inefficient states in Cameroon

International Nuclear Information System (INIS)

Adom, Philip Kofi

2016-01-01

I use a two-state (energy efficient/inefficient) Markov-switching dynamic model to study energy efficiency in Cameroon in a novel manner, employing yearly data covering 1971 to 2012. I find that the duration of an energy inefficient state is about twice as long as an energy efficient state, mainly due to fuel subsidies, low income, high corruption, regulatory inefficiencies, poorly developed infrastructure and undeveloped markets. To escape from an energy inefficient state a broad policy overhaul is needed. Trade liberalization and related growth policies together with the removal of fuel subsidies are useful, but insufficient policy measures; the results suggest that they should be combined with structural policies, aiming at institutional structure and investment in infrastructure. - Highlights: • I investigate the transition between energy efficient/inefficient states. • On the average, energy inefficient state persists more than energy efficient state. • The duration of energy inefficient state is about twice as long as energy efficient state. • Price, income and trade openness have distinct energy saving effect irrespective of state. • A broad policy overhaul is needed to escape the energy inefficient state.

EVIDENCE OF LIGHT-BENDING EFFECTS AND ITS IMPLICATION FOR SPECTRAL STATE TRANSITIONS

International Nuclear Information System (INIS)

Reis, R. C.; Miller, J. M.; Reynolds, M. T.; Fabian, A. C.; Walton, D. J.; Steiner, J. F.; Cackett, E.

2013-01-01

It has long been speculated that the nature of the hard X-ray corona may be an important second driver of black hole state transitions, in addition to the mass accretion rate through the disk. However, a clear physical picture of coronal changes has not yet emerged. We present results from a systematic analysis of Rossi X-Ray Timing Explorer observations of the stellar-mass black hole binary XTE J1650-500. All spectra with significant hard X-ray detections were fit using a self-consistent, relativistically blurred disk reflection model suited to high ionization regimes. Importantly, we find evidence that both the spectral and timing properties of black hole states may be partially driven by the height of the X-ray corona above the disk, and related changes in how gravitational light bending affects the corona-disk interaction. Specifically, the evolution of the power-law, thermal disk, and relativistically convolved reflection components in our spectral analysis indicates that: (1) the disk inner radius remains constant at r in =1.65 ± 0.08 GM/c 2 (consistent with values found for the ISCO of XTE J1650-500 in other works) throughout the transition from the brighter phases of the low-hard state to the intermediate states (both the hard-intermediate and soft-intermediate), through to the soft state and back; (2) the ratio between the observed reflected X-ray flux and power-law continuum (the 'reflection fraction', R) increases sharply at the transition between the hard-intermediate and soft-intermediate states ('ballistic' jets are sometimes launched at this transition); (3) both the frequency and coherence of the high-frequency quasi-periodic oscillations observed in XTE J1650-500 increase with R. We discuss our results in terms of black hole states and the nature of black hole accretion flows across the mass scale.

ChromAIX2: A large area, high count-rate energy-resolving photon counting ASIC for a Spectral CT Prototype

Science.gov (United States)

Steadman, Roger; Herrmann, Christoph; Livne, Amir

2017-08-01

Spectral CT based on energy-resolving photon counting detectors is expected to deliver additional diagnostic value at a lower dose than current state-of-the-art CT [1]. The capability of simultaneously providing a number of spectrally distinct measurements not only allows distinguishing between photo-electric and Compton interactions but also discriminating contrast agents that exhibit a K-edge discontinuity in the absorption spectrum, referred to as K-edge Imaging [2]. Such detectors are based on direct converting sensors (e.g. CdTe or CdZnTe) and high-rate photon counting electronics. To support the development of Spectral CT and show the feasibility of obtaining rates exceeding 10 Mcps/pixel (Poissonian observed count-rate), the ChromAIX ASIC has been previously reported showing 13.5 Mcps/pixel (150 Mcps/mm2 incident) [3]. The ChromAIX has been improved to offer the possibility of a large area coverage detector, and increased overall performance. The new ASIC is called ChromAIX2, and delivers count-rates exceeding 15 Mcps/pixel with an rms-noise performance of approximately 260 e-. It has an isotropic pixel pitch of 500 μm in an array of 22×32 pixels and is tile-able on three of its sides. The pixel topology consists of a two stage amplifier (CSA and Shaper) and a number of test features allowing to thoroughly characterize the ASIC without a sensor. A total of 5 independent thresholds are also available within each pixel, allowing to acquire 5 spectrally distinct measurements simultaneously. The ASIC also incorporates a baseline restorer to eliminate excess currents induced by the sensor (e.g. dark current and low frequency drifts) which would otherwise cause an energy estimation error. In this paper we report on the inherent electrical performance of the ChromAXI2 as well as measurements obtained with CZT (CdZnTe)/CdTe sensors and X-rays and radioactive sources.

Single-source dual-energy spectral multidetector CT of pancreatic adenocarcinoma: Optimization of energy level viewing significantly increases lesion contrast

International Nuclear Information System (INIS)

Patel, B.N.; Thomas, J.V.; Lockhart, M.E.; Berland, L.L.; Morgan, D.E.

2013-01-01

Aim: To evaluate lesion contrast in pancreatic adenocarcinoma patients using spectral multidetector computed tomography (MDCT) analysis. Materials and methods: The present institutional review board-approved, Health Insurance Portability and Accountability Act of 1996 (HIPAA)-compliant retrospective study evaluated 64 consecutive adults with pancreatic adenocarcinoma examined using a standardized, multiphasic protocol on a single-source, dual-energy MDCT system. Pancreatic phase images (35 s) were acquired in dual-energy mode; unenhanced and portal venous phases used standard MDCT. Lesion contrast was evaluated on an independent workstation using dual-energy analysis software, comparing tumour to non-tumoural pancreas attenuation (HU) differences and tumour diameter at three energy levels: 70 keV; individual subject-optimized viewing energy level (based on the maximum contrast-to-noise ratio, CNR); and 45 keV. The image noise was measured for the same three energies. Differences in lesion contrast, diameter, and noise between the different energy levels were analysed using analysis of variance (ANOVA). Quantitative differences in contrast gain between 70 keV and CNR-optimized viewing energies, and between CNR-optimized and 45 keV were compared using the paired t-test. Results: Thirty-four women and 30 men (mean age 68 years) had a mean tumour diameter of 3.6 cm. The median optimized energy level was 50 keV (range 40–77). The mean ± SD lesion contrast values (non-tumoural pancreas – tumour attenuation) were: 57 ± 29, 115 ± 70, and 146 ± 74 HU (p = 0.0005); the lengths of the tumours were: 3.6, 3.3, and 3.1 cm, respectively (p = 0.026); and the contrast to noise ratios were: 24 ± 7, 39 ± 12, and 59 ± 17 (p = 0.0005) for 70 keV, the optimized energy level, and 45 keV, respectively. For individuals, the mean ± SD contrast gain from 70 keV to the optimized energy level was 59 ± 45 HU; and the mean ± SD contrast gain from the optimized energy level to 45 ke

N-order Darboux transformation and a spectral problem on semiaxis

OpenAIRE

Bagrov, Vladislav G.; Samsonov, Boris F.; Shekoyan, L. A.

1998-01-01

N-order Darboux transformation operator is defined on the basis of a general notion of transformation operators. Factorisation properties of this operator are studied. The Darboux transformation operator technique is applied to construct and investigate potentials with bound states at arbitrary energies for the spectral problem on semiaxis.

GOSAT-2014 methane spectral line list

International Nuclear Information System (INIS)

Nikitin, A.V.; Lyulin, O.M.; Mikhailenko, S.N.; Perevalov, V.I.; Filippov, N.N.; Grigoriev, I.M.; Morino, I.; Yoshida, Y.; Matsunaga, T.

2015-01-01

The updated methane spectral line list GOSAT-2014 for the 5550–6240 cm −1 region with the intensity cutoff of 5×10 –25 cm/molecule at 296 K is presented. The line list is based on the extensive measurements of the methane spectral line parameters performed at different temperatures and pressures of methane without and with buffer gases N 2 , O 2 and air. It contains the following spectral line parameters of about 12150 transitions: line position, line intensity, energy of lower state, air-induced and self-pressure-induced broadening and shift coefficients and temperature exponent of air-broadening coefficient. The accuracy of the line positions and intensities are considerably improved in comparison with the previous version GOSAT-2009. The improvement of the line list is done mainly due to the involving to the line position and intensity retrieval of six new spectra recorded with short path way (8.75 cm). The air-broadening and air-shift coefficients for the J-manifolds of the 2ν 3 (F 2 ) band are refitted using the new more precise values of the line positions and intensities. The line assignment is considerably extended. The lower state J-value was assigned to 6397 lines representing 94.4% of integrated intensity of the considering wavenumber region. The complete assignment was done for 2750 lines. - Highlights: • The upgrade of the GOSAT methane line list in the 5550–6240 cm −1 region is done. • 12,146 experimental methane line positions and intensities are retrieved. • 6376 lower energy levels for methane lines are determined

Spectral statistics in chiral-orthogonal disordered systems

International Nuclear Information System (INIS)

Evangelou, S N; Katsanos, D E

2003-01-01

We describe the singularities in the averaged density of states and the corresponding statistics of the energy levels in two- (2D) and three-dimensional (3D) chiral symmetric and time-reversal invariant disordered systems, realized in bipartite lattices with real off-diagonal disorder. For off-diagonal disorder of zero mean, we obtain a singular density of states in 2D which becomes much less pronounced in 3D, while the level-statistics can be described by a semi-Poisson distribution with mostly critical fractal states in 2D and Wigner surmise with mostly delocalized states in 3D. For logarithmic off-diagonal disorder of large strength, we find behaviour indistinguishable from ordinary disorder with strong localization in any dimension but in addition one-dimensional 1/ vertical bar E vertical bar Dyson-like asymptotic spectral singularities. The off-diagonal disorder is also shown to enhance the propagation of two interacting particles similarly to systems with diagonal disorder. Although disordered models with chiral symmetry differ from non-chiral ones due to the presence of spectral singularities, both share the same qualitative localization properties except at the chiral symmetry point E=0 which is critical

Critically Evaluated Energy Levels, Spectral Lines, Transition Probabilities, and Intensities of Neutral Vanadium (V i)

Energy Technology Data Exchange (ETDEWEB)

Saloman, Edward B. [Dakota Consulting, Inc., 1110 Bonifant Street, Suite 310, Silver Spring, MD 20910 (United States); Kramida, Alexander [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)

2017-08-01

The energy levels, observed spectral lines, and transition probabilities of the neutral vanadium atom, V i, have been compiled. Also included are values for some forbidden lines that may be of interest to the astrophysical community. Experimental Landé g -factors and leading percentage compositions for the levels are included where available, as well as wavelengths calculated from the energy levels (Ritz wavelengths). Wavelengths are reported for 3985 transitions, and 549 energy levels are determined. The observed relative intensities normalized to a common scale are provided.

State Clean Energy Policies Analysis (SCEPA). State Policy and the Pursuit of Renewable Energy Manufacturing

Energy Technology Data Exchange (ETDEWEB)

Lantz, Eric [National Renewable Energy Lab. (NREL), Golden, CO (United States); Oteri, Frank [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tegen, Suzanne [National Renewable Energy Lab. (NREL), Golden, CO (United States); Doris, Elizabeth [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2010-02-01

Future manufacturing of renewable energy equipment in the United States provides economic development opportunities for state and local communities. However, demand for the equipment is finite, and opportunities are limited. U.S. demand is estimated to drive total annual investments in renewable energy equipment to $14-$20 billion by 2030. Evidence from leading states in renewable energy manufacturing suggests that economic development strategies that target renewable energy sector needs by adapting existing policies attract renewable energy manufacturing more than strategies that create new policies. Literature suggests that the states that are most able to attract direct investment and promote sustained economic development can leverage diverse sets of durable assets—like human capital and modern infrastructure–as well as low barriers to market entry. State marketing strategies for acquiring renewable energy manufacturers are likely best served by an approach that: (1) is multi-faceted and long-term, (2) fits within existing broad-based economic development strategies, (3) includes specific components such as support for renewable energy markets and low barriers to renewable energy deployment, and (4) involves increased differentiation by leveraging existing assets when applicable.

State Clean Energy Policies Analysis (SCEPA): State Policy and the Pursuit of Renewable Energy Manufacturing

Energy Technology Data Exchange (ETDEWEB)

Lantz, E.; Oteri, F.; Tegen, S.; Doris, E.

2010-02-01

Future manufacturing of renewable energy equipment in the United States provides economic development opportunities for state and local communities. However, demand for the equipment is finite, and opportunities are limited. U.S. demand is estimated to drive total annual investments in renewable energy equipment to $14-$20 billion by 2030. Evidence from leading states in renewable energy manufacturing suggests that economic development strategies that target renewable energy sector needs by adapting existing policies attract renewable energy manufacturing more than strategies that create new policies. Literature suggests that the states that are most able to attract direct investment and promote sustained economic development can leverage diverse sets of durable assets--like human capital and modern infrastructure--as well as low barriers to market entry. State marketing strategies for acquiring renewable energy manufacturers are likely best served by an approach that: (1) is multi-faceted and long-term, (2) fits within existing broad-based economic development strategies, (3) includes specific components such as support for renewable energy markets and low barriers to renewable energy deployment, and (4) involves increased differentiation by leveraging existing assets when applicable.

A New Measurement of the Spectral Lag of Gamma-Ray Bursts and its Implications for Spectral Evolution Behaviors

Energy Technology Data Exchange (ETDEWEB)

Shao, Lang; Wang, Fu-Ri; Cheng, Ye-Hao; Zhang, Xi; Yu, Bang-Yao; Xi, Bao-Jia; Wang, Xue; Feng, Huan-Xue; Zhang, Meng, E-mail: lshao@hebtu.edu.cn [Department of Space Sciences and Astronomy, Hebei Normal University, Shijiazhuang 050024 (China); Zhang, Bin-Bin [Instituto de Astrofísica de Andalucá (IAA-CSIC), P.O. Box 03004, E-18080 Granada (Spain); Wu, Xue-Feng [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Xu, Dong [Key Laboratory of Space Astronomy and Technology, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

2017-08-01

We carry out a systematical study of the spectral lag properties of 50 single-pulsed gamma-ray bursts (GRBs) detected by the Fermi Gamma-Ray Burst Monitor. By dividing the light curves into multiple consecutive energy channels, we provide a new measurement of the spectral lag that is independent of energy channel selections. We perform a detailed statistical study of our new measurements. We find two similar power-law energy dependencies of both the pulse arrival time and pulse width. Our new results on the power-law indices would favor the relativistic geometric effects for the origin of spectral lag. However, a complete theoretical framework that can fully account for the diverse energy dependencies of both arrival time and pulse width revealed in this work is still lacking. We also study the spectral evolution behaviors of the GRB pulses. We find that a GRB pulse with negligible spectral lag would usually have a shorter pulse duration and would appear to have a “hardness-intensity tracking” behavior, and a GRB pulse with a significant spectral lag would usually have a longer pulse duration and would appear to have a “hard-to-soft” behavior.

Modeling the high-energy electronic state manifold of adenine: Calibration for nonlinear electronic spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Nenov, Artur, E-mail: Artur.Nenov@unibo.it; Giussani, Angelo; Segarra-Martí, Javier; Jaiswal, Vishal K. [Dipartimento di Chimica “G. Ciamician,” Università di Bologna, Via Selmi 2, IT-40126 Bologna (Italy); Rivalta, Ivan [Université de Lyon, CNRS, Institut de Chimie de Lyon, École Normale Supérieure de Lyon, 46 Allée d’Italie, F-69364 Lyon Cedex 07 (France); Cerullo, Giulio [Dipartimento di Fisica, Politecnico di Milano, IFN-CNR, Piazza Leonardo Da Vinci 32, IT-20133 Milano (Italy); Mukamel, Shaul [Department of Chemistry, University of California, Irvine, California 92697-2025 (United States); Garavelli, Marco, E-mail: marco.garavelli@unibo.it, E-mail: marco.garavelli@ens-lyon.fr [Dipartimento di Chimica “G. Ciamician,” Università di Bologna, Via Selmi 2, IT-40126 Bologna (Italy); Université de Lyon, CNRS, Institut de Chimie de Lyon, École Normale Supérieure de Lyon, 46 Allée d’Italie, F-69364 Lyon Cedex 07 (France)

2015-06-07

Pump-probe electronic spectroscopy using femtosecond laser pulses has evolved into a standard tool for tracking ultrafast excited state dynamics. Its two-dimensional (2D) counterpart is becoming an increasingly available and promising technique for resolving many of the limitations of pump-probe caused by spectral congestion. The ability to simulate pump-probe and 2D spectra from ab initio computations would allow one to link mechanistic observables like molecular motions and the making/breaking of chemical bonds to experimental observables like excited state lifetimes and quantum yields. From a theoretical standpoint, the characterization of the electronic transitions in the visible (Vis)/ultraviolet (UV), which are excited via the interaction of a molecular system with the incoming pump/probe pulses, translates into the determination of a computationally challenging number of excited states (going over 100) even for small/medium sized systems. A protocol is therefore required to evaluate the fluctuations of spectral properties like transition energies and dipole moments as a function of the computational parameters and to estimate the effect of these fluctuations on the transient spectral appearance. In the present contribution such a protocol is presented within the framework of complete and restricted active space self-consistent field theory and its second-order perturbation theory extensions. The electronic excited states of adenine have been carefully characterized through a previously presented computational recipe [Nenov et al., Comput. Theor. Chem. 1040–1041, 295-303 (2014)]. A wise reduction of the level of theory has then been performed in order to obtain a computationally less demanding approach that is still able to reproduce the characteristic features of the reference data. Foreseeing the potentiality of 2D electronic spectroscopy to track polynucleotide ground and excited state dynamics, and in particular its expected ability to provide

Energy Metrics for State Government Buildings

Science.gov (United States)

Michael, Trevor

Measuring true progress towards energy conservation goals requires the accurate reporting and accounting of energy consumption. An accurate energy metrics framework is also a critical element for verifiable Greenhouse Gas Inventories. Energy conservation in government can reduce expenditures on energy costs leaving more funds available for public services. In addition to monetary savings, conserving energy can help to promote energy security, air quality, and a reduction of carbon footprint. With energy consumption/GHG inventories recently produced at the Federal level, state and local governments are beginning to also produce their own energy metrics systems. In recent years, many states have passed laws and executive orders which require their agencies to reduce energy consumption. In June 2008, SC state government established a law to achieve a 20% energy usage reduction in state buildings by 2020. This study examines case studies from other states who have established similar goals to uncover the methods used to establish an energy metrics system. Direct energy consumption in state government primarily comes from buildings and mobile sources. This study will focus exclusively on measuring energy consumption in state buildings. The case studies reveal that many states including SC are having issues gathering the data needed to accurately measure energy consumption across all state buildings. Common problems found include a lack of enforcement and incentives that encourage state agencies to participate in any reporting system. The case studies are aimed at finding the leverage used to gather the needed data. The various approaches at coercing participation will hopefully reveal methods that SC can use to establish the accurate metrics system needed to measure progress towards its 20% by 2020 energy reduction goal. Among the strongest incentives found in the case studies is the potential for monetary savings through energy efficiency. Framing energy conservation

State-level benefits of energy efficiency

International Nuclear Information System (INIS)

Tonn, Bruce; Peretz, Jean H.

2007-01-01

This paper describes benefits attributable to state-level energy efficiency programs. Nationwide, state-level energy efficiency programs have targeted all sectors of the economy and have employed a wide range of methods to promote energy efficiency. Standard residential and industrial programs typically identify between 20% and 30% energy savings in homes and plants, respectively. Over a 20-year period of time, an average state that aggressively pursues even a limited array of energy efficiency programs can potentially reduce total state energy use by as much as 20%. Well-designed energy efficiency programs can be expected to help overcome numerous barriers to the market penetration of energy efficient technologies and accelerate the market penetration of the technologies. Energy efficiency programs are cost-effective; typical benefit-cost ratios exceed 3:1 and are much higher when non-energy and macroeconomic benefits are included. Indeed, energy efficiency and associated programs and investments can create significant numbers of new jobs and enhance state tax revenues. Several states have incorporated energy efficiency into their economic development programs. It should also be noted that increasing amounts of venture capital are being invested in the energy sector in general and in specific technologies like solar power in particular. (author)

State-Level Benefits of Energy Efficiency

Energy Technology Data Exchange (ETDEWEB)

Tonn, Bruce Edward [ORNL

2007-02-01

This report describes benefits attributable to state-level energy efficiency programs. Nationwide, state-level energy efficiency programs have targeted all sectors of the economy and have employed a wide range of methods to promote energy efficiency. Standard residential and industrial programs typically identify between 20 to 30% energy savings in homes and plants, respectively. Over a 20 year period of time, an average state that aggressively pursues even a limited array of energy efficiency programs can potentially reduce total state energy use by as much as 20%. Benefit-cost ratios of effective energy efficiency programs typically exceed 3 to 1 and are much higher when non-energy and macroeconomic benefits are included. Indeed, energy efficiency and associated programs and investments can create significant numbers of new jobs and enhance state tax revenues. Several states have incorporated energy efficiency into their economic development programs. It should also be noted that increasing amounts of venture capital are being invested in the energy sector in general and in specific technologies like solar power in particular. Well-designed energy efficiency programs can be expected to help overcome numerous barriers to the market penetration of energy efficient technologies and accelerate the market penetration of the technologies.

Solid state linear dichroic infrared spectral analysis of benzimidazoles and their N 1-protonated salts

Science.gov (United States)

Ivanova, B. B.

2005-11-01

A stereo structural characterization of 2,5,6-thrimethylbenzimidazole (MBIZ) and 2-amino-benzimidaziole (2-NH 2-BI) and their N 1 protonation salts was carried out using a polarized solid state linear dichroic infrared spectral (IR-LD) analysis in nematic liquid crystal suspension. All experimental predicted structures were compared with the theoretical ones, obtained by ab initio calculations. The Cs to C2v* symmetry transformation as a result of protonation processes, with a view of its reflection on the infrared spectral characteristics was described.

"Assistance to States on Geothermal Energy"

Energy Technology Data Exchange (ETDEWEB)

Linda Sikkema; Jennifer DeCesaro

2006-07-10

This final report summarizes work carried out under agreement with the U.S. Department of Energy, related to geothermal energy policy issues. This project has involved a combination of outreach and publications on geothermal energy—Contract Number DE-FG03-01SF22367—with a specific focus on educating state-level policymakers. Education of state policymakers is vitally important because state policy (in the form of incentives or regulation) is a crucial part of the success of geothermal energy. State policymakers wield a significant influence over all of these policies. They are also in need of high quality, non-biased educational resources which this project provided. This project provided outreach to legislatures, in the form of responses to information requests on geothermal energy and publications. The publications addressed: geothermal leasing, geothermal policy, constitutional and statutory authority for the development of geothermal district energy systems, and state regulation of geothermal district energy systems. These publications were distributed to legislative energy committee members, and chairs, legislative staff, legislative libraries, and other related state officials. The effect of this effort has been to provide an extensive resource of information about geothermal energy for state policymakers in a form that is useful to them. This non-partisan information has been used as state policymakers attempt to develop their own policy proposals related to geothermal energy in the states. Coordination with the National Geothermal Collaborative: NCSL worked and coordinated with the National Geothermal Collaborative (NGC) to ensure that state legislatures were represented in all aspects of the NGC's efforts. NCSL participated in NGC steering committee conference calls, attended and participated in NGC business meetings and reviewed publications for the NGC. Additionally, NCSL and WSUEP staff drafted a series of eight issue briefs published by the

Sustainable energy in Baltic States

International Nuclear Information System (INIS)

Klevas, Valentinas; Streimikiene, Dalia; Grikstaite, Ramute

2007-01-01

Integration of New Member States to the European Union has created a new situation in the frame of implementation of the Lisbon strategy and EU Sustainable Development. The closure of Ignalina NPP is the biggest challenge to the energy sector development of the Baltic States. The Baltic States have quite limited own energy resources and in the Accession agreement with the EU Lithuania, Latvia and Estonia have verified their targets to increase the share of electricity produced from renewable energy sources (RES-E) by the year 2010. A wider use of renewable energy and increase of energy efficiency can make a valuable contribution to meeting the targets of sustainable development. The article presents a detailed overview of the present policies and measures implemented in the Baltic States, aiming to support the use of RES and the increase of energy efficiency. The review of possibilities to use the EU Structural Funds (SF) for the implementation of sustainable energy projects in the Baltic States was performed.The use of regional social-economic-environmental indicators is the main key to integrate sustainable energy development at the program deployment level. The indicators to be used should describe the contribution of energy programs to the sustainable development, medium- and long-term trends and inter-relationship between them and the typical energy indicators (saved toe, improved energy efficiency, percentage of RES). Municipalities may play a considerable role by promoting sustainable energy since local authorities are fulfilling their functions in the energy sector via a number of roles. The Netherlands' example shows that municipalities may act as facilitators by implementing national environmental policy and increasing energy efficiency in an integral part of these activities. The guidelines for Lithuanian local sustainable energy development using the SF co-financing have been presented

Unravelling radiative energy transfer in solid-state lighting

Science.gov (United States)

Melikov, Rustamzhon; Press, Daniel Aaron; Ganesh Kumar, Baskaran; Sadeghi, Sadra; Nizamoglu, Sedat

2018-01-01

Today, a wide variety of organic and inorganic luminescent materials (e.g., phosphors, quantum dots, etc.) are being used for lighting and new materials (e.g., graphene, perovskite, etc.) are currently under investigation. However, the understanding of radiative energy transfer is limited, even though it is critical to understand and improve the performance levels of solid-state lighting devices. In this study, we derived a matrix approach that includes absorption, reabsorption, inter-absorption and their iterative and combinatorial interactions for one and multiple types of fluorophores, which is simplified to an analytical matrix. This mathematical approach gives results that agree well with the measured spectral and efficiency characteristics of color-conversion light-emitting diodes. Moreover, it also provides a deep physical insight by uncovering the entire radiative interactions and their contribution to the output optical spectrum. The model is universal and applicable for all kinds of fluorophores.

A Black Hole Spectral Signature

Science.gov (United States)

Titarchuk, Lev; Laurent, Philippe

2000-03-01

An accreting black hole is, by definition, characterized by the drain. Namely, the matter falls into a black hole much the same way as water disappears down a drain matter goes in and nothing comes out. As this can only happen in a black hole, it provides a way to see ``a black hole'', an unique observational signature. The accretion proceeds almost in a free-fall manner close to the black hole horizon, where the strong gravitational field dominates the pressure forces. In this paper we present analytical calculations and Monte-Carlo simulations of the specific features of X-ray spectra formed as a result of upscattering of the soft (disk) photons in the converging inflow (CI) into the black hole. The full relativistic treatment has been implemented to reproduce these spectra. We show that spectra in the soft state of black hole systems (BHS) can be described as the sum of a thermal (disk) component and the convolution of some fraction of this component with the CI upscattering spread (Greens) function. The latter boosted photon component is seen as an extended power-law at energies much higher than the characteristic energy of the soft photons. We demonstrate the stability of the power spectral index over a wide range of the plasma temperature 0 - 10 keV and mass accretion rates (higher than 2 in Eddington units). We also demonstrate that the sharp high energy cutoff occurs at energies of 200-400 keV which are related to the average energy of electrons mec2 impinging upon the event horizon. The spectrum is practically identical to the standard thermal Comptonization spectrum when the CI plasma temperature is getting of order of 50 keV (the typical ones for the hard state of BHS). In this case one can see the effect of the bulk motion only at high energies where there is an excess in the CI spectrum with respect to the pure thermal one. Furthermore we demonstrate that the change of spectral shapes from the soft X-ray state to the hard X-ray state is clearly to be

Spectral features in the cosmic ray fluxes

Science.gov (United States)

Lipari, Paolo

2018-01-01

The cosmic ray energy distributions contain spectral features, that is narrow energy regions where the slope of the spectrum changes rapidly. The identification and study of these features is of great importance to understand the astrophysical mechanisms of acceleration and propagation that form the spectra. In first approximation a spectral feature is often described as a discontinuous change in slope, however very valuable information is also contained in its width, that is the length of the energy interval where the change in spectral index develops. In this work we discuss the best way to define and parameterize the width a spectral feature, and for illustration discuss some of the most prominent known structures.

Single-source dual-energy spectral multidetector CT of pancreatic adenocarcinoma: optimization of energy level viewing significantly increases lesion contrast.

Science.gov (United States)

Patel, B N; Thomas, J V; Lockhart, M E; Berland, L L; Morgan, D E

2013-02-01

To evaluate lesion contrast in pancreatic adenocarcinoma patients using spectral multidetector computed tomography (MDCT) analysis. The present institutional review board-approved, Health Insurance Portability and Accountability Act of 1996 (HIPAA)-compliant retrospective study evaluated 64 consecutive adults with pancreatic adenocarcinoma examined using a standardized, multiphasic protocol on a single-source, dual-energy MDCT system. Pancreatic phase images (35 s) were acquired in dual-energy mode; unenhanced and portal venous phases used standard MDCT. Lesion contrast was evaluated on an independent workstation using dual-energy analysis software, comparing tumour to non-tumoural pancreas attenuation (HU) differences and tumour diameter at three energy levels: 70 keV; individual subject-optimized viewing energy level (based on the maximum contrast-to-noise ratio, CNR); and 45 keV. The image noise was measured for the same three energies. Differences in lesion contrast, diameter, and noise between the different energy levels were analysed using analysis of variance (ANOVA). Quantitative differences in contrast gain between 70 keV and CNR-optimized viewing energies, and between CNR-optimized and 45 keV were compared using the paired t-test. Thirty-four women and 30 men (mean age 68 years) had a mean tumour diameter of 3.6 cm. The median optimized energy level was 50 keV (range 40-77). The mean ± SD lesion contrast values (non-tumoural pancreas - tumour attenuation) were: 57 ± 29, 115 ± 70, and 146 ± 74 HU (p = 0.0005); the lengths of the tumours were: 3.6, 3.3, and 3.1 cm, respectively (p = 0.026); and the contrast to noise ratios were: 24 ± 7, 39 ± 12, and 59 ± 17 (p = 0.0005) for 70 keV, the optimized energy level, and 45 keV, respectively. For individuals, the mean ± SD contrast gain from 70 keV to the optimized energy level was 59 ± 45 HU; and the mean ± SD contrast gain from the optimized energy level to 45 keV was 31 ± 25 HU (p = 0

Spectrally-engineered solar thermal photovoltaic devices

Science.gov (United States)

Lenert, Andrej; Bierman, David; Chan, Walker; Celanovic, Ivan; Soljacic, Marin; Wang, Evelyn N.; Nam, Young Suk; McEnaney, Kenneth; Kraemer, Daniel; Chen, Gang

2018-03-27

A solar thermal photovoltaic device, and method of forming same, includes a solar absorber and a spectrally selective emitter formed on either side of a thermally conductive substrate. The solar absorber is configured to absorb incident solar radiation. The solar absorber and the spectrally selective emitter are configured with an optimized emitter-to-absorber area ratio. The solar thermal photovoltaic device also includes a photovoltaic cell in thermal communication with the spectrally selective emitter. The spectrally selective emitter is configured to permit high emittance for energies above a bandgap of the photovoltaic cell and configured to permit low emittance for energies below the bandgap.

Ground-state and spectral properties of an asymmetric Hubbard ladder

Science.gov (United States)

Abdelwahab, Anas; Jeckelmann, Eric; Hohenadler, Martin

2015-04-01

We investigate a ladder system with two inequivalent legs, namely, a Hubbard chain and a one-dimensional electron gas. Analytical approximations, the density-matrix renormalization group method, and continuous-time quantum Monte Carlo simulations are used to determine ground-state properties, gaps, and spectral functions of this system at half-filling. Evidence for the existence of four different phases as a function of the Hubbard interaction and the rung hopping is presented. First, a Luttinger liquid exists at very weak interchain hopping. Second, a Kondo-Mott insulator with spin and charge gaps induced by an effective rung exchange coupling is found at moderate interchain hopping or strong Hubbard interaction. Third, a spin-gapped paramagnetic Mott insulator with incommensurate excitations and pairing of doped charges is observed at intermediate values of the rung hopping and the interaction. Fourth, the usual correlated band insulator is recovered for large rung hopping. We show that the wave numbers of the lowest single-particle excitations are different in each insulating phase. In particular, the three gapped phases exhibit markedly different spectral functions. We discuss the relevance of asymmetric two-leg ladder systems as models for atomic wires deposited on a substrate.

Spectral dimension of quantum geometries

International Nuclear Information System (INIS)

Calcagni, Gianluca; Oriti, Daniele; Thürigen, Johannes

2014-01-01

The spectral dimension is an indicator of geometry and topology of spacetime and a tool to compare the description of quantum geometry in various approaches to quantum gravity. This is possible because it can be defined not only on smooth geometries but also on discrete (e.g., simplicial) ones. In this paper, we consider the spectral dimension of quantum states of spatial geometry defined on combinatorial complexes endowed with additional algebraic data: the kinematical quantum states of loop quantum gravity (LQG). Preliminarily, the effects of topology and discreteness of classical discrete geometries are studied in a systematic manner. We look for states reproducing the spectral dimension of a classical space in the appropriate regime. We also test the hypothesis that in LQG, as in other approaches, there is a scale dependence of the spectral dimension, which runs from the topological dimension at large scales to a smaller one at short distances. While our results do not give any strong support to this hypothesis, we can however pinpoint when the topological dimension is reproduced by LQG quantum states. Overall, by exploring the interplay of combinatorial, topological and geometrical effects, and by considering various kinds of quantum states such as coherent states and their superpositions, we find that the spectral dimension of discrete quantum geometries is more sensitive to the underlying combinatorial structures than to the details of the additional data associated with them. (paper)

State energy data report 1993: Consumption estimates

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-07-01

The State Energy Data Report (SEDR) provides annual time series estimates of State-level energy consumption by major economic sector. The estimates are developed in the State Energy Data System (SEDS), which is maintained and operated by the Energy Information Administration (EIA). The goal in maintaining SEDS is to create historical time series of energy consumption by State that are defined as consistently as possible over time and across sectors. SEDS exists for two principal reasons: (1) to provide State energy consumption estimates to Members of Congress, Federal and State agencies, and the general public; and (2) to provide the historical series necessary for EIA`s energy models.

``New'' energy states lead to phonon-less optoelectronic properties in nanostructured silicon

Science.gov (United States)

Singh, Vivek; Yu, Yixuan; Korgel, Brian; Nagpal, Prashant

2014-03-01

Silicon is arguably one of the most important technological material for electronic applications. However, indirect bandgap of silicon semiconductor has prevented optoelectronic applications due to phonon assistance required for photon light absorption/emission. Here we show, that previously unexplored surface states in nanostructured silicon can couple with quantum-confined energy levels, leading to phonon-less exciton-recombination and photoluminescence. We demonstrate size dependence (2.4 - 8.3 nm) of this coupling observed in small uniform silicon nanocrystallites, or quantum-dots, by direct measurements of their electronic density of states and low temperature measurements. To enhance the optical absorption of the these silicon quantum-dots, we utilize generation of resonant surface plasmon polariton waves, which leads to several fold increase in observed spectrally-resolved photocurrent near the quantum-confined bandedge states. Therefore, these enhanced light emission and absorption enhancement can have important implications for applications of nanostructured silicon for optoelectronic applications in photovoltaics and LEDs.

The value of energy spectral CT in the differential diagnosis between benign and malignant soft tissue masses of the musculoskeletal system

Energy Technology Data Exchange (ETDEWEB)

Sun, Xin [Department of Radiology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong (China); Shao, Xiaodong [Department of Radiology, Qingdao Municipal Hospital, Qingdao, Shandong (China); Chen, Haisong, E-mail: chsEJR@163.com [Department of Radiology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong (China)

2015-06-15

Highlights: • Different types of tissues have different types of spectral curves. • We find that spectral curve is useful in the differential diagnosis of benign and malignant tumor of the musculoskeletal system. • Arc shaped curve is a specific sign for tumors containing abundant fat. - Abstract: Objective: To explore the value of energy spectral CT in the differential diagnosis between benign and malignant tumor of the musculoskeletal system. Methods: Energy spectral CT scan was performed on 100 patients with soft tissue mass caused by musculoskeletal tumors found by MRI. Solid areas with homogenous density were chosen as region of interests (ROI), avoiding necrosis, hemorrhage and calcification region. Select the optimal keV on single energy images, and then the keV–CT curve was automatically generated. All 100 cases of tumors proved by histological examination were divided into four groups, 38 cases were in benign group, 10 cases in borderline group, 49 cases in malignant group, and 3 cases of lipoma (that were analyzed separately since its curve was arc shaped, significantly different from other curves). The formula used to calculate the slope of spectral curve was as follows: slope = (Hu40 keV − Hu80 keV)/40. As the slope was steep within the range of 40–80 keV based on preliminary observations, 40 keV and 80 keV were used as the reference points to calculate the slope value of the energy spectral curve. Kruskal–Wallis rank sum test was applied for statistical analysis, and P < 0.05 was considered to indicate a statistically significant difference. Results: The spectral curve of benign group was gradually falling type with a mean slope of 0.75 ± 0.30, that of malignant group was sharply falling type with a mean slope of 1.64 ± 1.00, and that of borderline group was a falling type between the above two groups with a mean slope of 1.34 ± 0.45. The differences of slopes between benign and malignant group, benign and borderline group were of

Integrated Spectral Energy Distributions and Absorption Feature Indices of Single Stellar Populations

OpenAIRE

Zhang, Fenghui; Han, Zhanwen; Li, Lifang; Hurley, Jarrod R.

2004-01-01

Using evolutionary population synthesis, we present integrated spectral energy distributions and absorption-line indices defined by the Lick Observatory image dissector scanner (referred to as Lick/IDS) system, for an extensive set of instantaneous burst single stellar populations (SSPs). The ages of the SSPs are in the range 1-19 Gyr and the metallicities [Fe/H] are in the range -2.3 - 0.2. Our models use the rapid single stellar evolution algorithm of Hurley, Pols and Tout for the stellar e...

Recent Advances in Cardiac Computed Tomography: Dual Energy, Spectral and Molecular CT Imaging

Science.gov (United States)

Danad, Ibrahim; Fayad, Zahi A.; Willemink, Martin J.; Min, James K.

2015-01-01

Computed tomography (CT) evolved into a powerful diagnostic tool and it is impossible to imagine current clinical practice without CT imaging. Due to its widespread availability, ease of clinical application, superb sensitivity for detection of CAD, and non-invasive nature, CT has become a valuable tool within the armamentarium of the cardiologist. In the last few years, numerous technological advances in CT have occurred—including dual energy CT (DECT), spectral CT and CT-based molecular imaging. By harnessing the advances in technology, cardiac CT has advanced beyond the mere evaluation of coronary stenosis to an imaging modality tool that permits accurate plaque characterization, assessment of myocardial perfusion and even probing of molecular processes that are involved in coronary atherosclerosis. Novel innovations in CT contrast agents and pre-clinical spectral CT devices have paved the way for CT-based molecular imaging. PMID:26068288

Spectral flow of trimer states of two heavy impurities and one light condensed boson

DEFF Research Database (Denmark)

Zinner, Nikolaj Thomas

2014-01-01

The spectral flow of three-body (trimer) states consisting of two heavy (impurity) particles sitting in a condensate of light bosons is considered. Assuming that the condensate is weakly interaction and that an impurity and a boson have a zero-range two-body interaction, we use the Born...

State energy data report 1995 - consumption estimates

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-01

The State Energy Data Report (SEDR) provides annual time series estimates of State-level energy consumption by major economic sectors. The estimates are developed in the State Energy Data System (SEDS), which is maintained and operated by the Energy Information Administration (EIA). The goal in maintaining SEDS exists for two principal reasons: (1) to provide State energy consumption estimates to Members of Congress, Federal and State agencies, and the general public, and (2) to provide the historical series necessary for EIA`s energy models.

Determination of the Spectral Index in the Fission Spectrum Energy Regime

Energy Technology Data Exchange (ETDEWEB)

Lee, Amy Sarah [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-05-16

Neutron reaction cross sections play a vital role in tracking the production and destruction of isotopes exposed to neutron fluence. They are central to the process of reconciling the initial and final atom inventories. Measurements of irradiated samples by radiochemical methods in tangent with an algorithm are used to evaluate the fluence a sample is exposed to over the course of the irradiation. This algorithm is the Isotope Production Code (IPC) created and used by the radiochemistry data assessment team at Los Alamos National Laboratory (LANL). An integral result is calculated by varying the total neutron fluence seen by a sample. A sample, irradiated in a critical assembly, will be exposed to a unique neutron flux defined by the neutron source and distance of the sample from the source. Neutron cross sections utilized are a function of the hardness of the neutron spectrum at the location of irradiation. A spectral index is used an indicator of the hardness of the neutron spectrum. Cross sections fit forms applied in IPC are collapsed from a LANL 30-group energy structure. Several decades of research and development have been performed to formalize the current IPC cross section library. Basis of the current fission spectrum neutron reaction cross section library is rooted in critical assembly experiments performed from the 1950’s through the early 1970’s at LANL. The focus of this report is development of the spectral index used an indicator of the hardness of the neutron spectrum in the fission spectrum energy regime.

Revisiting the Correlations of Peak Luminosity with Spectral Lag and Peak Energy of the Observed Gamma-ray Bursts

Directory of Open Access Journals (Sweden)

Yun-A Jo

2016-12-01

Full Text Available An analysis of light curves and spectra of observed gamma-ray bursts in gamma-ray ranges is frequently demanded because the prompt emission contains immediate details regarding the central engine of gamma-ray bursts (GRBs. We have revisited the relationship between the collimation-corrected peak luminosity and the spectral lag, investigating the lag-luminosity relationships in great detail by focusing on spectral lags resulting from all possible combinations of channels. Firstly, we compiled the opening angle data and demonstrated that the distribution of opening angles of 205 long GRBs is represented by a double Gaussian function having maxima at ~ 0.1 and ~ 0.3 radians. We confirmed that the peak luminosity and the spectral lag are anti-correlated, both in the observer frame and in the source frame. We found that, in agreement with our previous conclusion, the correlation coefficient improves significantly in the source frame. It should be noted that spectral lags involving channel 2 (25-50 keV yield high correlation coefficients, where Swift/Burst Alert Telescope (BAT has four energy channels (channel 1: 15-25 keV, channel 2: 25-50 keV, channel 3: 50-100 keV, channel 4: 100-200 keV. We also found that peak luminosity is positively correlated with peak energy.

State Energy Data Report, 1991: Consumption estimates

International Nuclear Information System (INIS)

1993-05-01

The State Energy Data Report (SEDR) provides annual time series estimates of State-level energy consumption by major economic sector. The estimates are developed in the State Energy Data System (SEDS), which is maintained and operated by the Energy Information Administration (EIA). The goal in maintaining SEDS is to create historical time series of energy consumption by State that are defined as consistently as possible over time and across sectors. SEDS exists for two principal reasons: (1) to provide State energy consumption estimates to the Government, policy makers, and the public; and (2) to provide the historical series necessary for EIA's energy models

Excited-state formation as H+ and He+ ions scatter from metal surfaces

International Nuclear Information System (INIS)

Baird, W.E.; Zivitz, M.; Thomas, E.W.

1975-01-01

Impact of 10-to30KeV H + or He + ions on polycrystalline metal surfaces causes some projectiles to be backscattered in a neutral excited state. These projectiles subsequently radiatively decay, emitting Doppler-broadened spectral lines. By analysis of the spectral shape of these lines, we are able to determine the probability of radiationless deexcitation of the excited backscattered atoms. Quantitative measurements of spectral intensity indicate that less than 1% of all projectiles are backscattered in an excited state. The relative variation of total spectral line intensity with angle of projectile incidence and with projectile primary energy has been successfully predicted using a model which assumes that the probability for excited-state formation is independent of the scattered projectile's energy and direction. The variation in total spectral line intensity with target atomic number is predicted, and the sputtering and excitation of Al under He + impact is briefly examined

10. State energy balance - 1978-1991

International Nuclear Information System (INIS)

1993-12-01

The energetic matrix of Minas Gerais State (Brazil) for the year 1991 and historic review of 1978 to 1990 are shown in this 10. State Energy Balance. The global balance and the state structure of energy demand, by energy source and socio-economic sector are presented, and the relations between energy system and the Minas Gerais economic performance are analysed. The consumption evolution by sector is also cited. (C.G.C.)

Differentiation of urinary calculi with dual energy CT: effect of spectral shaping by high energy tin filtration.

Science.gov (United States)

Thomas, Christoph; Krauss, Bernhard; Ketelsen, Dominik; Tsiflikas, Ilias; Reimann, Anja; Werner, Matthias; Schilling, David; Hennenlotter, Jörg; Claussen, Claus D; Schlemmer, Heinz-Peter; Heuschmid, Martin

2010-07-01

In dual energy (DE) computed tomography (CT), spectral shaping by additional filtration of the high energy spectrum can theoretically improve dual energy contrast. The aim of this in vitro study was to examine the influence of an additional tin filter for the differentiation of human urinary calculi by dual energy CT. A total of 36 pure human urinary calculi (uric acid, cystine, calciumoxalate monohydrate, calciumoxalate dihydrate, carbonatapatite, brushite, average diameter 10.5 mm) were placed in a phantom and imaged with 2 dual source CT scanners. One scanner was equipped with an additional tin (Sn) filter. Different combinations of tube voltages (140/80 kV, 140/100 kV, Sn140/100 kV, Sn140/80 kV, with Sn140 referring to 140 kV with the tin filter) were applied. Tube currents were adapted to yield comparable dose indices. Low- and high energy images were reconstructed. The calculi were segmented semiautomatically in the datasets and DE ratios (attenuation@low_kV/attenuation@high_kV) and were calculated for each calculus. DE contrasts (DE-ratio_material1/DE-ratio_material2) were computed for uric acid, cystine and calcified calculi and compared between the combinations of tube voltages. Using exclusively DE ratios, all uric acid, cystine and calcified calculi (as a group) could be differentiated in all protocols; the calcified calculi could not be differentiated among each other in any examination protocol. The highest DE ratios and DE contrasts were measured for the Sn140/80 protocol (53%-62% higher DE contrast than in the 140/80 kV protocol without additional filtration). The DE ratios and DE contrasts of the 80/140 kV and 100/Sn140 kV protocols were comparable. Uric acid, cystine and calcified calculi could be reliably differentiated by any of the protocols. A dose-neutral gain of DE contrast was found in the Sn-filter protocols, which might improve the differentiation of smaller calculi (Sn140/80 kV) and improve image quality and calculi differentiation in

Metal artefact reduction in gemstone spectral imaging dual-energy CT with and without metal artefact reduction software

International Nuclear Information System (INIS)

Lee, Young Han; Song, Ho-Taek; Kim, Sungjun; Suh, Jin-Suck; Park, Kwan Kyu

2012-01-01

To assess the usefulness of gemstone spectral imaging (GSI) dual-energy CT (DECT) with/without metal artefact reduction software (MARs). The DECTs were performed using fast kV-switching GSI between 80 and 140 kV. The CT data were retro-reconstructed with/without MARs, by different displayed fields-of-view (DFOV), and with synthesised monochromatic energy in the range 40-140 keV. A phantom study of size and CT numbers was performed in a titanium plate and a stainless steel plate. A clinical study was performed in 26 patients with metallic hardware. All images were retrospectively reviewed in terms of the visualisation of periprosthetic regions and the severity of beam-hardening artefacts by using a five-point scale. The GSI-MARs reconstruction can markedly reduce the metal-related artefacts, and the image quality was affected by the prosthesis composition and DFOV. The spectral CT numbers of the prosthesis and periprosthetic regions showed different patterns on stainless steel and titanium plates. Dual-energy CT with GSI-MARs can reduce metal-related artefacts and improve the delineation of the prosthesis and periprosthetic region. We should be cautious when using GSI-MARs because the image quality was affected by the prosthesis composition, energy (in keV) and DFOV. The metallic composition and size should be considered in metallic imaging with GSI-MARs reconstruction. circle Metal-related artefacts can be troublesome on musculoskeletal computed tomography (CT). circle Gemstone spectral imaging (GSI) with dual-energy CT (DECT) offers a novel solution circle GSI and metallic artefact reduction software (GSI-MAR) can markedly reduce these artefacts. circle However image quality is influenced by the prosthesis composition and other parameters. circle We should be aware about potential overcorrection when using GSI-MARs. (orig.)

Spectral Analysis, Synthesis, & Energy Distributions of Nearby E+A Galaxies Using SDSS-IV MaNGA

Science.gov (United States)

Weaver, Olivia A.; Anderson, Miguel Ricardo; Wally, Muhammad; James, Olivia; Falcone, Julia; Liu, Allen; Wallack, Nicole; Liu, Charles; SDSS Collaboration

2017-01-01

Utilizing data from the Mapping Nearby Galaxies at APO (MaNGA) Survey (MaNGA Product Launch-4, or MPL-4), of the latest generation of the Sloan Digital Sky Survey (SDSS-IV), we identified nine post-starburst (E+A) systems that lie within the Green Valley transition zone. We identify the E+A galaxies by their SDSS single fiber spectrum and u-r color, then confirmed their classification as post-starburst by coding/plotting methods and spectral synthesis codes (FIREFLY and PIPE3D), as well as with their Spectral Energy Distributions (SEDs) from 0.15 µm to 22 µm, using GALEX, SDSS, 2MASS, and WISE data. We produced maps of gaussian-fitted fluxes, equivalent widths, stellar velocities, metallicities and age. We also produced spectral line ratio diagrams to classify regions of stellar populations of the galaxies. We found that our sample of E+As retain their post-starburst properties across the entire galaxy, not just at their center. We detected matching a trend line in the ultraviolet and optical bands, consistent with the expected SEDs for an E+A galaxy, and also through the J, H and Ks bands, except for one object. We classified one of the nine galaxies as a luminous infrared galaxy, unusual for a post-starburst object. Our group seeks to further study stellar population properties, spectral energy distributions and quenching properties in E+A galaxies, and investigate their role in galaxy evolution as a whole. This work was supported by the Alfred P. Sloan Foundation via the SDSS-IV Faculty and Student Team (FAST) initiative, ARC Agreement #SSP483 to the CUNY College of Staten Island. This work was also supported by grants to The American Museum of Natural History, and the CUNY College of Staten Island through from National Science Foundation.

State energy data report 1996: Consumption estimates

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-02-01

The State Energy Data Report (SEDR) provides annual time series estimates of State-level energy consumption by major economic sectors. The estimates are developed in the Combined State Energy Data System (CSEDS), which is maintained and operated by the Energy Information Administration (EIA). The goal in maintaining CSEDS is to create historical time series of energy consumption by State that are defined as consistently as possible over time and across sectors. CSEDS exists for two principal reasons: (1) to provide State energy consumption estimates to Members of Congress, Federal and State agencies, and the general public and (2) to provide the historical series necessary for EIA`s energy models. To the degree possible, energy consumption has been assigned to five sectors: residential, commercial, industrial, transportation, and electric utility sectors. Fuels covered are coal, natural gas, petroleum, nuclear electric power, hydroelectric power, biomass, and other, defined as electric power generated from geothermal, wind, photovoltaic, and solar thermal energy. 322 tabs.

State energy data report 1996: Consumption estimates

International Nuclear Information System (INIS)

1999-02-01

The State Energy Data Report (SEDR) provides annual time series estimates of State-level energy consumption by major economic sectors. The estimates are developed in the Combined State Energy Data System (CSEDS), which is maintained and operated by the Energy Information Administration (EIA). The goal in maintaining CSEDS is to create historical time series of energy consumption by State that are defined as consistently as possible over time and across sectors. CSEDS exists for two principal reasons: (1) to provide State energy consumption estimates to Members of Congress, Federal and State agencies, and the general public and (2) to provide the historical series necessary for EIA's energy models. To the degree possible, energy consumption has been assigned to five sectors: residential, commercial, industrial, transportation, and electric utility sectors. Fuels covered are coal, natural gas, petroleum, nuclear electric power, hydroelectric power, biomass, and other, defined as electric power generated from geothermal, wind, photovoltaic, and solar thermal energy. 322 tabs

Preliminary study on the differentiation between parapelvic cyst and hydronephrosis with non-calculous using only pre-contrast dual-energy spectral CT scans

Science.gov (United States)

Han, Dong; Ma, Guangming; Wei, Lequn; Ren, Chenglong; Zhou, Jieli; Shen, Chen

2017-01-01

Objective: To investigate the value of using the quantitative parameters from only the pre-contrast dual-energy spectral CT imaging for distinguishing between parapelvic cyst and hydronephrosis with non-calculous (HNC). Methods: This retrospective study was approved by the institutional review board. 28 patients with parapelvic cyst and 24 patients with HNC who underwent standard pre-contrast and multiphase contrast-enhanced dual-energy spectral CT imaging were retrospectively identified. The parapelvic cyst and HNC were identified using the contrast-enhanced scans, and their CT number in the 70-keV monochromatic images, effective atomic number (Zeff), iodine concentration (IC) and water concentration in the pre-contrast images were measured. The slope of the spectral curve (λ) was calculated. The difference in the measurements between parapelvic cyst and HNC was statistically analyzed using SPSS® v. 19.0 (IBM Corp., New York, NY; formerly SPSS Inc., Chicago, IL) statistical software. Receiver-operating characteristic analysis was performed to assess the diagnostic performance. Results: The CT numbers in the 70-keV images, Zeff and IC values were statistically different between parapelvic cyst and HNC (all p  0.05). Conclusion: The quantitative parameters obtained in the pre-contrast dual-energy spectral CT imaging may be used to differentiate between parapelvic cyst and HNC. Advances in knowledge: The pre-contrast dual-energy spectral CT scans may be used to screen parapelvic cysts for patients who are asymptomatic, thereby avoiding contrast-enhanced CT or CT urography examination for these patients to reduce ionizing radiation dose and contrast dose. PMID:28281789

State energy data report 1994: Consumption estimates

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-10-01

This document provides annual time series estimates of State-level energy consumption by major economic sector. The estimates are developed in the State Energy Data System (SEDS), operated by EIA. SEDS provides State energy consumption estimates to members of Congress, Federal and State agencies, and the general public, and provides the historical series needed for EIA`s energy models. Division is made for each energy type and end use sector. Nuclear electric power is included.

State energy data report 1994: Consumption estimates

International Nuclear Information System (INIS)

1996-10-01

This document provides annual time series estimates of State-level energy consumption by major economic sector. The estimates are developed in the State Energy Data System (SEDS), operated by EIA. SEDS provides State energy consumption estimates to members of Congress, Federal and State agencies, and the general public, and provides the historical series needed for EIA's energy models. Division is made for each energy type and end use sector. Nuclear electric power is included

iSEDfit: Bayesian spectral energy distribution modeling of galaxies

Science.gov (United States)

Moustakas, John

2017-08-01

iSEDfit uses Bayesian inference to extract the physical properties of galaxies from their observed broadband photometric spectral energy distribution (SED). In its default mode, the inputs to iSEDfit are the measured photometry (fluxes and corresponding inverse variances) and a measurement of the galaxy redshift. Alternatively, iSEDfit can be used to estimate photometric redshifts from the input photometry alone. After the priors have been specified, iSEDfit calculates the marginalized posterior probability distributions for the physical parameters of interest, including the stellar mass, star-formation rate, dust content, star formation history, and stellar metallicity. iSEDfit also optionally computes K-corrections and produces multiple "quality assurance" (QA) plots at each stage of the modeling procedure to aid in the interpretation of the prior parameter choices and subsequent fitting results. The software is distributed as part of the impro IDL suite.

The Renormalization-Group Method in the Problem on Calculation of the Spectral Energy Density of Fluid Turbulence

Science.gov (United States)

Teodorovich, E. V.

2018-03-01

In order to find the shape of energy spectrum within the framework of the model of stationary homogeneous isotropic turbulence, the renormalization-group equations, which reflect the Markovian nature of the mechanism of energy transfer along the wavenumber spectrum, are used in addition to the dimensional considerations and the energy balance equation. For the spectrum, the formula depends on three parameters, namely, the wavenumber, which determines the upper boundary of the range of the turbulent energy production, the spectral flux through this boundary, and the fluid kinematic viscosity.

State-to-State Mode Specificity: Energy Sequestration and Flow Gated by Transition State.

Science.gov (United States)

Zhao, Bin; Sun, Zhigang; Guo, Hua

2015-12-23

Energy flow and sequestration at the state-to-state level are investigated for a prototypical four-atom reaction, H2 + OH → H + H2O, using a transition-state wave packet (TSWP) method. The product state distribution is found to depend strongly on the reactant vibrational excitation, indicating mode specificity at the state-to-state level. From a local-mode perspective, it is shown that the vibrational excitation of the H2O product derives from two different sources, one attributable to the energy flow along the reaction coordinate into the newly formed OH bond and the other due to the sequestration of the vibrational energy in the OH spectator moiety during the reaction. The analysis provided a unified interpretation of some seemingly contradicting experimental observations. It is further shown that the transfer of vibrational energy from the OH reactant to H2O product is gated by the transition state, accomplished coherently by multiple TSWPs with the corresponding OH vibrational excitation.

A Different View of Solar Spectral Irradiance Variations: Modeling Total Energy over Six-Month Intervals.

Science.gov (United States)

Woods, Thomas N; Snow, Martin; Harder, Jerald; Chapman, Gary; Cookson, Angela

A different approach to studying solar spectral irradiance (SSI) variations, without the need for long-term (multi-year) instrument degradation corrections, is examining the total energy of the irradiance variation during 6-month periods. This duration is selected because a solar active region typically appears suddenly and then takes 5 to 7 months to decay and disperse back into the quiet-Sun network. The solar outburst energy, which is defined as the irradiance integrated over the 6-month period and thus includes the energy from all phases of active region evolution, could be considered the primary cause for the irradiance variations. Because solar cycle variation is the consequence of multiple active region outbursts, understanding the energy spectral variation may provide a reasonable estimate of the variations for the 11-year solar activity cycle. The moderate-term (6-month) variations from the Solar Radiation and Climate Experiment (SORCE) instruments can be decomposed into positive (in-phase with solar cycle) and negative (out-of-phase) contributions by modeling the variations using the San Fernando Observatory (SFO) facular excess and sunspot deficit proxies, respectively. These excess and deficit variations are fit over 6-month intervals every 2 months over the mission, and these fitted variations are then integrated over time for the 6-month energy. The dominant component indicates which wavelengths are in-phase and which are out-of-phase with solar activity. The results from this study indicate out-of-phase variations for the 1400 - 1600 nm range, with all other wavelengths having in-phase variations.

The value of energy spectral CT in the differential diagnosis between benign and malignant soft tissue masses of the musculoskeletal system.

Science.gov (United States)

Sun, Xin; Shao, Xiaodong; Chen, Haisong

2015-06-01

To explore the value of energy spectral CT in the differential diagnosis between benign and malignant tumor of the musculoskeletal system. Energy spectral CT scan was performed on 100 patients with soft tissue mass caused by musculoskeletal tumors found by MRI. Solid areas with homogenous density were chosen as region of interests (ROI), avoiding necrosis, hemorrhage and calcification region. Select the optimal keV on single energy images, and then the keV-CT curve was automatically generated. All 100 cases of tumors proved by histological examination were divided into four groups, 38 cases were in benign group, 10 cases in borderline group, 49 cases in malignant group, and 3 cases of lipoma (that were analyzed separately since its curve was arc shaped, significantly different from other curves). The formula used to calculate the slope of spectral curve was as follows: slope=(Hu40 keV-Hu80 keV)/40. As the slope was steep within the range of 40-80 keV based on preliminary observations, 40 keV and 80 keV were used as the reference points to calculate the slope value of the energy spectral curve. Kruskal-Wallis rank sum test was applied for statistical analysis, and Pbenign and malignant group, benign and borderline group were of statistical significance (Pbenign and malignant tumor of the musculoskeletal system. Arc shaped curve is a specific sign for tumors containing abundant fat. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Are resting state spectral power measures related to executive functions in healthy young adults?

Science.gov (United States)

Gordon, Shirley; Todder, Doron; Deutsch, Inbal; Garbi, Dror; Getter, Nir; Meiran, Nachshon

2018-01-08

Resting-state electroencephalogram (rsEEG) has been found to be associated with psychopathology, intelligence, problem solving, academic performance and is sometimes used as a supportive physiological indicator of enhancement in cognitive training interventions (e.g. neurofeedback, working memory training). In the current study, we measured rsEEG spectral power measures (relative power, between-band ratios and asymmetry) in one hundred sixty five young adults who were also tested on a battery of executive function (EF). We specifically focused on upper Alpha, Theta and Beta frequency bands given their putative role in EF. Our indices enabled finding correlations since they had decent-to-excellent internal and retest reliability and very little range restriction relative to a nation-wide representative large sample. Nonetheless, Bayesian statistical inference indicated support for the null hypothesis concerning lack of monotonic correlation between EF and rsEEG spectral power measures. Therefore, we conclude that, contrary to the quite common interpretation, these rsEEG spectral power measures do not indicate individual differences in the measured EF abilities. Copyright © 2017 Elsevier Ltd. All rights reserved.

Spectral representation of the particle production out of equilibrium—Schwinger mechanism in pulsed electric fields

International Nuclear Information System (INIS)

Fukushima, Kenji

2014-01-01

We develop a formalism to describe the particle production out of equilibrium in terms of dynamical spectral functions, i.e. Wigner transformed Pauli–Jordan's and Hadamard's functions. We take an explicit example of a spatially homogeneous scalar theory under pulsed electric fields and investigate the time evolution of the spectral functions. In the out-state we find an oscillatory peak in Hadamard's function as a result of the mixing between positive- and negative-energy waves. The strength of this peak is of the linear order of the Bogoliubov mixing coefficient, whereas the peak corresponding to the Schwinger mechanism is of the quadratic order. Between the in- and the out-states we observe a continuous flow of the spectral peaks together with two transient oscillatory peaks. We also discuss the medium effect at finite temperature and density. We emphasize that the entire structure of the spectral functions conveys rich information on real-time dynamics including the particle production. (paper)

Nanoscale probing of bandgap states on oxide particles using electron energy-loss spectroscopy.

Science.gov (United States)

Liu, Qianlang; March, Katia; Crozier, Peter A

2017-07-01

Surface and near-surface electronic states were probed with nanometer spatial resolution in MgO and TiO 2 anatase nanoparticles using ultra-high energy resolution electron energy-loss spectroscopy (EELS) coupled to a scanning transmission electron microscope (STEM). This combination allows the surface electronic structure determined with spectroscopy to be correlated with nanoparticle size, morphology, facet etc. By acquiring the spectra in aloof beam mode, radiation damage to the surface can be significantly reduced while maintaining the nanometer spatial resolution. MgO and TiO 2 showed very different bandgap features associated with the surface/sub-surface layer of the nanoparticles. Spectral simulations based on dielectric theory and density of states models showed that a plateau feature found in the pre-bandgap region in the spectra from (100) surfaces of 60nm MgO nanocubes is consistent with a thin hydroxide surface layer. The spectroscopy shows that this hydroxide species gives rise to a broad filled surface state at 1.1eV above the MgO valence band. At the surfaces of TiO 2 nanoparticles, pronounced peaks were observed in the bandgap region, which could not be well fitted to defect states. In this case, the high refractive index and large particle size may make Cherenkov or guided light modes the likely causes of the peaks. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of localization states on the electroluminescence spectral width of blue–green light emitting InGaN/GaN multiple quantum wells

Energy Technology Data Exchange (ETDEWEB)

Liu, Wei [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China and School of Electronic and Electrical Engineering, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Zhao, De Gang, E-mail: dgzhao@red.semi.ac.cn; Jiang, De Sheng; Chen, Ping; Liu, Zong Shun; Zhu, Jian Jun; Li, Xiang; Shi, Ming; Zhao, Dan Mei [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Liu, Jian Ping; Zhang, Shu Ming; Wang, Hui; Yang, Hui [Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215125 (China)

2015-11-15

The electroluminescence (EL) spectra of blue–green light emitting InGaN/GaN multiple quantum well (MQW) structures grown via metal-organic chemical vapor deposition are investigated. With increasing In content in InGaN well layers, the peak energy redshifts, the emission intensity reduces and the inhomogeneous broadening of the luminescence band increases. In addition, it is found that the EL spectra shrink with increasing injection current at low excitation condition, which may be ascribed to both Coulomb screening of polarization field and carrier transferring from shallower localization states to the deeper ones, while at high currents the state-filling effect in all localization states may become significant and lead to a broadening of EL spectra. However, surprisingly, for the MQW sample with much higher In content, the EL spectral bandwidth can be almost unchanged with increasing current at the high current range, since a large number of carriers may be captured by the nonradiative recombination centers distributed outside the localized potential traps and the state-filling effect in the localization states is suppressed.

Effect of localization states on the electroluminescence spectral width of blue–green light emitting InGaN/GaN multiple quantum wells

International Nuclear Information System (INIS)

Liu, Wei; Zhao, De Gang; Jiang, De Sheng; Chen, Ping; Liu, Zong Shun; Zhu, Jian Jun; Li, Xiang; Shi, Ming; Zhao, Dan Mei; Liu, Jian Ping; Zhang, Shu Ming; Wang, Hui; Yang, Hui

2015-01-01

The electroluminescence (EL) spectra of blue–green light emitting InGaN/GaN multiple quantum well (MQW) structures grown via metal-organic chemical vapor deposition are investigated. With increasing In content in InGaN well layers, the peak energy redshifts, the emission intensity reduces and the inhomogeneous broadening of the luminescence band increases. In addition, it is found that the EL spectra shrink with increasing injection current at low excitation condition, which may be ascribed to both Coulomb screening of polarization field and carrier transferring from shallower localization states to the deeper ones, while at high currents the state-filling effect in all localization states may become significant and lead to a broadening of EL spectra. However, surprisingly, for the MQW sample with much higher In content, the EL spectral bandwidth can be almost unchanged with increasing current at the high current range, since a large number of carriers may be captured by the nonradiative recombination centers distributed outside the localized potential traps and the state-filling effect in the localization states is suppressed

Dual-Energy Computed Tomography Gemstone Spectral Imaging: A Novel Technique to Determine Human Cardiac Calculus Composition.

Science.gov (United States)

Cheng, Ching-Li; Chang, Hsiao-Huang; Ko, Shih-Chi; Huang, Pei-Jung; Lin, Shan-Yang

2016-01-01

Understanding the chemical composition of any calculus in different human organs is essential for choosing the best treatment strategy for patients. The purpose of this study was to assess the capability of determining the chemical composition of a human cardiac calculus using gemstone spectral imaging (GSI) mode on a single-source dual-energy computed tomography (DECT) in vitro. The cardiac calculus was directly scanned on the Discovery CT750 HD FREEdom Edition using GSI mode, in vitro. A portable fiber-optic Raman spectroscopy was also applied to verify the quantitative accuracy of the DECT measurements. The results of spectral DECT measurements indicate that effective Z values in 3 designated positions located in this calculus were 15.02 to 15.47, which are close to values of 15.74 to 15.86, corresponding to the effective Z values of calcium apatite and hydroxyapatite. The Raman spectral data were also reflected by the predominant Raman peak at 960 cm for hydroxyapatite and the minor peak at 875 cm for calcium apatite. A potential single-source DECT with GSI mode was first used to examine the morphological characteristics and chemical compositions of a giant human cardiac calculus, in vitro. The CT results were consistent with the Raman spectral data, suggesting that spectral CT imaging techniques could be accurately used to diagnose and characterize the compositional materials in the cardiac calculus.

Spectral-Efficiency - Illumination Pareto Front for Energy Harvesting Enabled VLC System

KAUST Repository

Abdelhady, Amr Mohamed Abdelaziz

2017-12-13

The continuous improvement in optical energy harvesting devices motivates visible light communication (VLC) system developers to utilize such available free energy sources. An outdoor VLC system is considered where an optical base station sends data to multiple users that are capable of harvesting the optical energy. The proposed VLC system serves multiple users using time division multiple access (TDMA) with unequal time and power allocation, which are allocated to improve the system performance. The adopted optical system provides users with illumination and data communication services. The outdoor optical design objective is to maximize the illumination, while the communication design objective is to maximize the spectral efficiency (SE). The design objectives are shown to be conflicting, therefore, a multiobjective optimization problem is formulated to obtain the Pareto front performance curve for the proposed system. To this end, the marginal optimization problems are solved first using low complexity algorithms. Then, based on the proposed algorithms, a low complexity algorithm is developed to obtain an inner bound of the Pareto front for the illumination-SE tradeoff. The inner bound for the Pareto-front is shown to be close to the optimal Pareto-frontier via several simulation scenarios for different system parameters.

State Energy Resilience Framework

Energy Technology Data Exchange (ETDEWEB)

Phillips, J. [Argonne National Lab. (ANL), Argonne, IL (United States); Finster, M. [Argonne National Lab. (ANL), Argonne, IL (United States); Pillon, J. [Argonne National Lab. (ANL), Argonne, IL (United States); Petit, F. [Argonne National Lab. (ANL), Argonne, IL (United States); Trail, J. [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-12-01

The energy sector infrastructure’s high degree of interconnectedness with other critical infrastructure systems can lead to cascading and escalating failures that can strongly affect both economic and social activities.The operational goal is to maintain energy availability for customers and consumers. For this body of work, a State Energy Resilience Framework in five steps is proposed.

Loss energy states of nonstationary quantum systems

International Nuclear Information System (INIS)

Dodonov, V.V.; Man'ko, V.I.

1978-01-01

The concept of loss energy states is introduced. The loss energy states of the quantum harmonic damping oscillator are considered in detail. The method of constructing the loss energy states for general multidimensional quadratic nonstationary quantum systems is briefly discussed

Spectrally selective solar energy materials

International Nuclear Information System (INIS)

Sikkens, M.

1981-01-01

The performance and properties of spectrally selective materials are considered and, in particular, the selective absorption of solar radiation by free electrons is discussed, both in a homogeneous material in which these electrons are strongly scattered, and in a composite material consisting of small metal particles in a dielectric host. Such materials can be used as selective absorbers if they are deposited as a thin film onto a metal substrate, the latter providing the required low emittance. This type of selective surfaces is produced by reactive sputtering of Ni in an Ar/CH 4 gas mixture. This method can yield Ni films with a considerable carbon concentration. The carbon concentration can be varied over a wide range by adjusting the partial methane pressure. The associated experimental techniques are discussed. As the carbon concentration increases, the structure of the films changes from a Ni phase in which carbon is dissolved, via an intermediate Ni 3 C phase into an amorphous carbon phase with a high electrical resistivity in which small nickel particles are embedded. Both mechanisms of selective absorption by free electrons are observed and are found to be well described by rather simple models. The best selectivity is obtained at high carbon concentrations where the films consist of nickel particles in carbon. Depending on the film thickness and the substrate material, the solar absorptance varies between 0.78 and 0.90, while the thermal emittance varies between 0.025 and 0.04. Since the films are found to be stable at 400 0 C in vacuum, it appears that these films are good candidates for application in photothermal solar energy conversion at temperature levels around 200 0 C and higher. (Auth.)

Development of Neutron Energy Spectral Signatures for Passive Monitoring of Spent Nuclear Fuels in Dry Cask Storage

Science.gov (United States)

Harkness, Ira; Zhu, Ting; Liang, Yinong; Rauch, Eric; Enqvist, Andreas; Jordan, Kelly A.

2018-01-01

Demand for spent nuclear fuel dry casks as an interim storage solution has increased globally and the IAEA has expressed a need for robust safeguards and verification technologies for ensuring the continuity of knowledge and the integrity of radioactive materials inside spent fuel casks. Existing research has been focusing on "fingerprinting" casks based on count rate statistics to represent radiation emission signatures. The current research aims to expand to include neutron energy spectral information as part of the fuel characteristics. First, spent fuel composition data are taken from the Next Generation Safeguards Initiative Spent Fuel Libraries, representative for Westinghouse 17ˣ17 PWR assemblies. The ORIGEN-S code then calculates the spontaneous fission and (α,n) emissions for individual fuel rods, followed by detailed MCNP simulations of neutrons transported through the fuel assemblies. A comprehensive database of neutron energy spectral profiles is to be constructed, with different enrichment, burn-up, and cooling time conditions. The end goal is to utilize the computational spent fuel library, predictive algorithm, and a pressurized 4He scintillator to verify the spent fuel assemblies inside a cask. This work identifies neutron spectral signatures that correlate with the cooling time of spent fuel. Both the total and relative contributions from spontaneous fission and (α,n) change noticeably with respect to cooling time, due to the relatively short half-life (18 years) of the major neutron source 244Cm. Identification of this and other neutron spectral signatures allows the characterization of spent nuclear fuels in dry cask storage.

Dual energy spectral CT imaging for the evaluation of small hepatocellular carcinoma microvascular invasion.

Science.gov (United States)

Yang, Chuang-Bo; Zhang, Shuang; Jia, Yong-Jun; Yu, Yong; Duan, Hai-Feng; Zhang, Xi-Rong; Ma, Guang-Ming; Ren, Chenglong; Yu, Nan

2017-10-01

To study the clinical value of dual-energy spectral CT in the quantitative assessment of microvascular invasion of small hepatocellular carcinoma. This study was approved by our ethics committee. 50 patients with small hepatocellular carcinoma who underwent contrast enhanced spectral CT in arterial phase (AP) and portal venous phase (VP) were enrolled. Tumour CT value and iodine concentration (IC) were measured from spectral CT images. The slope of spectral curve, normalized iodine concentration (NIC, to abdominal aorta) and ratio of IC difference between AP and VP (RIC AP-VP : [RIC AP-VP =(IC AP -IC VP )/IC AP ]) were calculated. Tumours were identified as either with or without microvascular invasion based on pathological results. Measurements were statistically compared using independent samples t test. The receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic performance of tumours microvascular invasion assessment. The 70keV images were used to simulate the results of conventional CT scans for comparison. 56 small hepatocellular carcinomas were detected with 37 lesions (Group A) with microvascular invasion and 19 (Group B) without. There were significant differences in IC, NIC and slope in AP and RIC AP-VP between Group A (2.48±0.70mg/ml, 0.23±0.05, 3.39±1.01 and 0.28±0.16) and Group B (1.65±0.47mg/ml, 0.15±0.05, 2.22±0.64 and 0.03±0.24) (all phepatocellular carcinoma with and without microvascular invasion. Quantitative iodine concentration measurement in spectral CT may be used to provide a new method to improve the evaluation for small hepatocellular carcinoma microvascular invasion. Copyright © 2017 Elsevier B.V. All rights reserved.

COMBINED ANALYSIS OF IMAGES AND SPECTRAL ENERGY DISTRIBUTIONS OF TAURUS PROTOSTARS

International Nuclear Information System (INIS)

Gramajo, Luciana V.; Gomez, Mercedes; Whitney, Barbara A.; Robitaille, Thomas P.

2010-01-01

We present an analysis of spectral energy distributions (SEDs), near- and mid-infrared images, and Spitzer spectra of eight embedded Class I/II objects in the Taurus-Auriga molecular cloud. The initial model for each source was chosen using the grid of young stellar objects (YSOs) and SED fitting tool of Robitaille et al. Then the models were refined using the radiative transfer code of Whitney et al. to fit both the spectra and the infrared images of these objects. In general, our models agree with previous published analyses. However, our combined models should provide more reliable determinations of the physical and geometrical parameters since they are derived from SEDs, including the Spitzer spectra, covering the complete spectral range; and high-resolution near-infrared and Spitzer IRAC images. The combination of SED and image modeling better constrains the different components (central source, disk, envelope) of the YSOs. Our derived luminosities are higher, on average, than previous estimates because we account for the viewing angles (usually nearly edge-on) of most of the sources. Our analysis suggests that the standard rotating collapsing protostar model with disks and bipolar cavities works well for the analyzed sample of objects in the Taurus molecular cloud.

State energy price and expenditure report 1990

International Nuclear Information System (INIS)

1992-01-01

The State Energy Price and Expenditure Report (SEPER) presents energy price and expenditure estimates individually for the 50 States and the District of Columbia and in aggregate for the United States. The estimates are provided by energy source and economic sector. This report is an update of the State Energy Price and Expenditure Report 1989 published in September 1991. Energy price and expenditure estimates are published for the years 1970, 1975, 1980, and 1985 through 1990. Documentation follows the tables and describes how the price estimates are developed, including sources of data, methods of estimation, and conversion factors applied

Spectral energy transfer of atmospheric gravity waves through sum and difference nonlinear interactions

Energy Technology Data Exchange (ETDEWEB)

Huang, K.M. [Wuhan Univ. (China). School of Electronic Information; Chinese Academey of Sciences, Hefei (China). Key Lab. of Geospace Environment; Embry Riddle Aeronautical Univ., Daytona Beach, FL (United States). Dept. of Physical Science; Ministry of Education, Wuhan (China). Key Lab. of Geospace Environment and Geodesy; State Observatory for Atmospheric Remote Sensing, Wuhan (China); Liu, A.Z.; Li, Z. [Embry Riddle Aeronautical Univ., Daytona Beach, FL (United States). Dept. of Physical Science; Zhang, S.D.; Yi, F. [Wuhan Univ. (China). School of Electronic Information; Ministry of Education, Wuhan (China). Key Lab. of Geospace Environment and Geodesy; State Observatory for Atmospheric Remote Sensing, Wuhan (China)

2012-07-01

Nonlinear interactions of gravity waves are studied with a two-dimensional, fully nonlinear model. The energy exchanges among resonant and near-resonant triads are examined in order to understand the spectral energy transfer through interactions. The results show that in both resonant and near-resonant interactions, the energy exchange between two high frequency waves is strong, but the energy transfer from large to small vertical scale waves is rather weak. This suggests that the energy cascade toward large vertical wavenumbers through nonlinear interaction is inefficient, which is different from the rapid turbulence cascade. Because of considerable energy exchange, nonlinear interactions can effectively spread high frequency spectrum, and play a significant role in limiting wave amplitude growth and transferring energy into higher altitudes. In resonant interaction, the interacting waves obey the resonant matching conditions, and resonant excitation is reversible, while near-resonant excitation is not so. Although near-resonant interaction shows the complexity of match relation, numerical experiments show an interesting result that when sum and difference near-resonant interactions occur between high and low frequency waves, the wave vectors tend to approximately match in horizontal direction, and the frequency of the excited waves is also close to the matching value. (orig.)

Prediction of the association state of insulin using spectral parameters.

Science.gov (United States)

Uversky, Vladimir N; Garriques, Liza Nielsen; Millett, Ian S; Frokjaer, Sven; Brange, Jens; Doniach, Sebastian; Fink, Anthony L

2003-04-01

Human insulin exists in different association states, from monomer to hexamer, depending on the conditions. In the presence of zinc the "normal" state is a hexamer. The structural properties of 20 variants of human insulin were studied by near-UV circular dichroism, fluorescence spectroscopy, and small-angle X-ray scattering (SAXS). The mutants showed different degrees of association (monomer, dimers, tetramers, and hexamers) at neutral pH. A correlation was shown between the accessibility of tyrosines to acrylamide quenching and the degree of association of the insulin mutants. The near-UV CD spectra of the insulins were affected by protein association and by mutation-induced structural perturbations. However, the shape and intensity of difference CD spectra, obtained by subtraction of the spectra measured in 20% acetic acid (where all insulin species were monomeric) from the corresponding spectra measured at neutral pH, correlate well with the degree of insulin association. In fact, the near-UV CD difference spectra for monomeric, dimeric, tetrameric, and hexameric insulin are very distinctive, both in terms of intensity and shape. The results show that the spectral properties of the insulins reflect their state of association, and can be used to predict their oligomeric state. Copyright 2003 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 92:847-858, 2003

Scaling function, spectral function and nucleon momentum distribution in nuclei

International Nuclear Information System (INIS)

Antonov, A.N.; Ivanov, M.V.; Caballero, J.A.; Barbaro, M.B.; Udias, J.M.; Moya de Guerra, E.; Donnelly, T.W.

2010-01-01

The aim of the study is to find a good simultaneous description of the spectral function and the momentum distribution in relation to the realistic scaling function obtained from inclusive electron-nuclei scattering experiments. We start with a modified Hartree-Fock spectral function in which the energy dependent part (δ-function) is replaced by the Gaussian distributions with hole state widths as free parameters. We calculate the scaling function and the nucleon momentum distribution on the basis of the spectral function constructed in this way, trying to find a good description of the experimental data. The obtained scaling function has a weak asymmetry and the momentum distribution has not got a high-momentum tail in the case when harmonic-oscillator single-particle wave functions are used. So, to improve the behavior of the momentum distribution we used the basis of natural orbitals (NO) in which short-range correlations are partly incorporated. The results for the scaling function show again a weak asymmetry, but in this case the momentum distribution has a high-momentum tail. As a next step we include final-state interactions (FSI) in the calculations to reproduce the experimentally observed asymmetry of the scaling function. (author)

Analysis of spectral effects on the energy yield of different PV (photovoltaic) technologies: The case of four specific sites

International Nuclear Information System (INIS)

Alonso-Abella, M.; Chenlo, F.; Nofuentes, G.; Torres-Ramírez, M.

2014-01-01

This work is aimed at looking into the impact of the solar spectrum distribution on the energy yield of some PV (photovoltaic) materials on both monthly and annual time scales. The relative spectral responses of eight different PV solar cells – representative of each considered technology – have been selected. Modeling solar spectra in four sites located in the north hemisphere together with a 12-month experimental campaign in which spectral irradiances were periodically recorded in two of these sites located in Spain have provided highly interesting results. Regardless of the site, the considered amorphous silicon and cadmium telluride PV cells experience the most noticeable modeled and experimental variations of their monthly spectral gains, whilst flatter seasonal ones are identified in the remaining considered PV technologies. Thus, the maximum monthly variations of these spectral gains take place in the a-Si PV cell, ranging from −16% (winter) to 4% (summer) in Stuttgart. Anyway, the monthly spread of the spectral effects decreases as the latitude of the site does. Last, the impact of the solar spectrum distribution is remarkably reduced when the period of integration is enlarged up to a year. In fact, annual spectral gains keep below 2.2% for all the studied technologies and sites. - Highlights: • Monthly and annual spectral effects on eight different PV (photovoltaic) technologies studied. • Modeled spectra in four sites combined with relative spectral responses. • Measured spectra (12 months) in two sites combined with relative spectral responses. • Higher bandgap technologies: noticeable monthly variations in their spectral gains. • Annual spectral gains keep below 2.2% for all the studied technologies and sites

Charge-Transfer Processes in Warm Dense Matter: Selective Spectral Filtering for Laser-Accelerated Ion Beams

Science.gov (United States)

Braenzel, J.; Barriga-Carrasco, M. D.; Morales, R.; Schnürer, M.

2018-05-01

We investigate, both experimentally and theoretically, how the spectral distribution of laser accelerated carbon ions can be filtered by charge exchange processes in a double foil target setup. Carbon ions at multiple charge states with an initially wide kinetic energy spectrum, from 0.1 to 18 MeV, were detected with a remarkably narrow spectral bandwidth after they had passed through an ultrathin and partially ionized foil. With our theoretical calculations, we demonstrate that this process is a consequence of the evolution of the carbon ion charge states in the second foil. We calculated the resulting spectral distribution separately for each ion species by solving the rate equations for electron loss and capture processes within a collisional radiative model. We determine how the efficiency of charge transfer processes can be manipulated by controlling the ionization degree of the transfer matter.

Spectral memory of photoconduction of high-resistance ZnSe

International Nuclear Information System (INIS)

Gorya, O.S.; Kovalev, L.E.; Korotkov, V.A.; Malikova, L.V.; Simashkevich, A.V.

1989-01-01

Relaxation of photoconductivity of ZnSr crystal in case of a photoconductivity burst when exposing a sample to light with quantum energy E=1.305 eV after preliminary excitation by light with quantum energy 2.61 eV. The phenomenon of nonequilibrium photoconductivity considered permitted to suggest a new method for determination of the energy position of local levels in the forbidden band of semiconductors. Investigations carried out permitted to detect in ZnSe acceptors, lying in the forbidden band, as well as deep centers. It is supposed that the effect of spectral memory of photoconductivity of high-ohmic crystals (ZnSe, ZnS, CdS) relates to the existence of defects with metastable states in them

Spectral probes of the holographic Fermi ground state: Dialing between the electron star and AdS Dirac hair

International Nuclear Information System (INIS)

Cubrovic, Mihailo; Liu Yan; Schalm, Koenraad; Sun Yawen; Zaanen, Jan

2011-01-01

We argue that the electron star and the anti-de Sitter (AdS) Dirac hair solution are two limits of the free charged Fermi gas in AdS. Spectral functions of holographic duals to probe fermions in the background of electron stars have a free parameter that quantifies the number of constituent fermions that make up the charge and energy density characterizing the electron star solution. The strict electron star limit takes this number to be infinite. The Dirac hair solution is the limit where this number is unity. This is evident in the behavior of the distribution of holographically dual Fermi surfaces. As we decrease the number of constituents in a fixed electron star background the number of Fermi surfaces also decreases. An improved holographic Fermi ground state should be a configuration that shares the qualitative properties of both limits.

Energy Efficiency Resources to Support State Energy Planning

Energy Technology Data Exchange (ETDEWEB)

Office of Strategic Programs, Strategic Priorities and Impact Analysis Team

2017-06-01

An early step for most energy efficiency planning is to identify and quantify energy savings opportunities, and then to understand how to access this potential. The U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy offers resources that can help with both of these steps. This fact sheet presents those resources. The resources are also available on the DOE State and Local Solution Center on the "Energy Efficiency: Savings Opportunities and Benefits" page: https://energy.gov/eere/slsc/energy-efficiency-savings-opportunities-and-benefits.

Energy and spectral efficiency analysis for selective ARQ multi-channel systems

KAUST Repository

Shafique, Taniya

2017-07-31

In this paper, we develop selective retransmission schemes for multiple-channel systems. The proposed schemes are selective automatic repeat request with fixed bandwidth (SARQ-FB), selective chase combining with fixed bandwidth (SCC-FB) and selective automatic repeat request with variable bandwidth (SARQ-VB). The main objective of the proposed schemes is to use the available power and bandwidth budget effectively along with the selective retransmission to deliver the required data successfully within a limited number of transmissions. To investigate the performance of each scheme, we first analyze the average spectral and energy efficiency and derive closed form expressions for each scheme. Then, we compare the EE and SE of each scheme through numerical results.

State-to-state dynamics of molecular energy transfer

Energy Technology Data Exchange (ETDEWEB)

Gentry, W.R.; Giese, C.F. [Univ. of Minnesota, Minneapolis (United States)

1993-12-01

The goal of this research program is to elucidate the elementary dynamical mechanisms of vibrational and rotational energy transfer between molecules, at a quantum-state resolved level of detail. Molecular beam techniques are used to isolate individual molecular collisions, and to control the kinetic energy of collision. Lasers are used both to prepare specific quantum states prior to collision by stimulated-emission pumping (SEP), and to measure the distribution of quantum states in the collision products by laser-induced fluorescence (LIF). The results are interpreted in terms of dynamical models, which may be cast in a classical, semiclassical or quantum mechanical framework, as appropriate.

Two-photon spectral amplitude of entangled states resolved in separable Schmidt modes

International Nuclear Information System (INIS)

Avella, A; Brida, G; Gramegna, M; Shurupov, A; Genovese, M; Chekhova, M

2015-01-01

The ability to access high dimensionality in Hilbert spaces represents a demanding key-stone for state-of-the-art quantum information. The manipulation of entangled states in continuous variables, wavevector as well frequency, represents a powerful resource in this sense. The number of dimensions of the Hilbert space that can be used in practical information protocols can be determined by the number of Schmidt modes that it is possible to address one by one. In the case of wavevector variables, the Schmidt modes can be losslessly selected using single-mode fibre and a spatial light modulator, but no similar procedure exists for the frequency space. The aim of this work is to present a technique to engineer the spectral properties of biphoton light, emitted via ultrafast spontaneous parametric down conversion, in such a way that the two-photon spectral amplitude (TPSA) contains several non-overlapping Schmidt modes, each of which can be filtered losslessly in frequency variables. Such TPSA manipulation is operated by a fine balancing of parameters like the pump frequency, the shaping of pump pulse spectrum, the dispersion dependence of spontaneous parametric down-conversion crystals as well as their length. Measurements have been performed exploiting the group velocity dispersion induced by the passage of optical fields through dispersive media, operating a frequency-to-time two-dimensional Fourier transform of the TPSA. Exploiting this kind of measurement we experimentally demonstrate the ability to control the Schmidt modes structure in TPSA through the pump spectrum manipulation. (paper)

Star formation relations and CO spectral line energy distributions across the J-ladder and redshift

Energy Technology Data Exchange (ETDEWEB)

Greve, T. R. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Leonidaki, I.; Xilouris, E. M. [Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, GR-15236 Penteli (Greece); Weiß, A.; Henkel, C. [Max-Planck-Institut fur Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Zhang, Z.-Y. [UK Astronomy Technology Centre, Science and Technology Facilities Council, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ (United Kingdom); Van der Werf, P.; Meijerink, R. [Leiden Observatory, Leiden University, PO Box 9513, NL-2300 RA Leiden (Netherlands); Aalto, S. [Department of Earth and Space Sciences, Chalmers University of Technology, Onsala Observatory, 43994 Onsala (Sweden); Armus, L.; Díaz-Santos, T. [Spitzer Science Center, California Institute of Technology, MS 220-6, Pasadena, CA 91125 (United States); Evans, A. S. [Astronomy Department, University of Virginia Charlottesville, VA 22904 (United States); Fischer, J. [Naval Research Laboratory, Remote Sensing Division, 4555 Overlook Avenue SW, Washington, DC 20375 (United States); Gao, Y. [Purple Mountain Observatory, Chinese Academy of Sciences, 2 West Beijing Road, Nanjing 210008 (China); González-Alfonso, E. [Universidad de Alcala de Henares, Departamento de Fśica, Campus Universitario, E-28871 Alcalá de Henares, Madrid (Spain); Harris, A. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Naylor, D. A. [Institute for Space Imaging Science, Department of Physics and Astronomy, University of Lethbridge, Lethbridge, AB T1K 3M4 (Canada); Smith, H. A. [Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Spaans, M., E-mail: t.greve@ucl.ac.uk [Kapteyn Astronomical Institute, University of Groningen, PO Box 800, 9700 AV Groningen (Netherlands); and others

2014-10-20

We present FIR [50-300 μm]–CO luminosity relations (i.e., log L{sub FIR}=αlog L{sub CO}{sup ′}+β) for the full CO rotational ladder from J = 1-0 up to J = 13-12 for a sample of 62 local (z ≤ 0.1) (Ultra) Luminous Infrared Galaxies (LIRGs; L {sub IR[8-1000} {sub μm]} > 10{sup 11} L {sub ☉}) using data from Herschel SPIRE-FTS and ground-based telescopes. We extend our sample to high redshifts (z > 1) by including 35 submillimeter selected dusty star forming galaxies from the literature with robust CO observations, and sufficiently well-sampled FIR/submillimeter spectral energy distributions (SEDs), so that accurate FIR luminosities can be determined. The addition of luminous starbursts at high redshifts enlarge the range of the FIR–CO luminosity relations toward the high-IR-luminosity end, while also significantly increasing the small amount of mid-J/high-J CO line data (J = 5-4 and higher) that was available prior to Herschel. This new data set (both in terms of IR luminosity and J-ladder) reveals linear FIR–CO luminosity relations (i.e., α ≅ 1) for J = 1-0 up to J = 5-4, with a nearly constant normalization (β ∼ 2). In the simplest physical scenario, this is expected from the (also) linear FIR–(molecular line) relations recently found for the dense gas tracer lines (HCN and CS), as long as the dense gas mass fraction does not vary strongly within our (merger/starburst)-dominated sample. However, from J = 6-5 and up to the J = 13-12 transition, we find an increasingly sublinear slope and higher normalization constant with increasing J. We argue that these are caused by a warm (∼100 K) and dense (>10{sup 4} cm{sup –3}) gas component whose thermal state is unlikely to be maintained by star-formation-powered far-UV radiation fields (and thus is no longer directly tied to the star formation rate). We suggest that mechanical heating (e.g., supernova-driven turbulence and shocks), and not cosmic rays, is the more likely source of energy for

Front Surface Tandem Filters using Sapphire (Al2O3) Substrates for Spectral Control in thermophotovoltaic Energy Conversion Systems

International Nuclear Information System (INIS)

T Rahmlow, Jr.; J Lazo-Wasem; E Gratrix; P Fourspring; D DePoy

2005-01-01

Front surface filters provide an effective means of improving thermophotovoltaic (TPV) system efficiency through spectral control of incident radiant energy. A front surface filter reflects the below band gap photons that can not be converted by the TPV cell back towards the high temperature radiator and allows convertible above band gap photons to pass through the filter into the TPV cell for conversion to electricity. The best spectral control efficiency to date has been demonstrated by front surface, tandem filters that combine an interference filter and an InPAs layer (plasma filter) in series. The InPAs material is a highly doped, epitaxially grown layer on an InP substrate. These tandem filter designs have been fabricated with energy and angle weighted spectral efficiencies of 76% for TPV cells with a 2.08(micro)m (0.6eV) band gap [1]. An alternative to the InPAs layer on an InP substrate is an Al 2 O 3 (sapphire) substrate. The use of Al 2 O 3 may increase transmission of above band gap photons, increase the mechanical strength of the tandem filter, and lower the cost of the tandem filter, all at the expense of lower spectral efficiency. This study presents design and fabrication results for front surface tandem filters that use an Al 2 O 3 substrate for 2.08(micro)m band gap TPV cells

Baseline brain energy supports the state of consciousness.

Science.gov (United States)

Shulman, Robert G; Hyder, Fahmeed; Rothman, Douglas L

2009-07-07

An individual, human or animal, is defined to be in a conscious state empirically by the behavioral ability to respond meaningfully to stimuli, whereas the loss of consciousness is defined by unresponsiveness. PET measurements of glucose or oxygen consumption show a widespread approximately 45% reduction in cerebral energy consumption with anesthesia-induced loss of consciousness. Because baseline brain energy consumption has been shown by (13)C magnetic resonance spectroscopy to be almost exclusively dedicated to neuronal signaling, we propose that the high level of brain energy is a necessary property of the conscious state. Two additional neuronal properties of the conscious state change with anesthesia. The delocalized fMRI activity patterns in rat brain during sensory stimulation at a higher energy state (close to the awake) collapse to a contralateral somatosensory response at lower energy state (deep anesthesia). Firing rates of an ensemble of neurons in the rat somatosensory cortex shift from the gamma-band range (20-40 Hz) at higher energy state to energy state. With the conscious state defined by the individual's behavior and maintained by high cerebral energy, measurable properties of that state are the widespread fMRI patterns and high frequency neuronal activity, both of which support the extensive interregional communication characteristic of consciousness. This usage of high brain energies when the person is in the "state" of consciousness differs from most studies, which attend the smaller energy increments observed during the stimulations that form the "contents" of that state.

Spectral properties of embedded Gaussian unitary ensemble of random matrices with Wigner's SU(4) symmetry

International Nuclear Information System (INIS)

Vyas, Manan; Kota, V.K.B.

2010-01-01

For m fermions in Ω number of single particle orbitals, each fourfold degenerate, we introduce and analyze in detail embedded Gaussian unitary ensemble of random matrices generated by random two-body interactions that are SU(4) scalar [EGUE(2)-SU(4)]. Here the SU(4) algebra corresponds to the Wigner's supermultiplet SU(4) symmetry in nuclei. Embedding algebra for the EGUE(2)-SU(4) ensemble is U(4Ω) contains U(Ω) x SU(4). Exploiting the Wigner-Racah algebra of the embedding algebra, analytical expression for the ensemble average of the product of any two m particle Hamiltonian matrix elements is derived. Using this, formulas for a special class of U(Ω) irreducible representations (irreps) {4 r , p}, p = 0, 1, 2, 3 are derived for the ensemble averaged spectral variances and also for the covariances in energy centroids and spectral variances. On the other hand, simplifying the tabulations of Hecht for SU(Ω) Racah coefficients, numerical calculations are carried out for general U(Ω) irreps. Spectral variances clearly show, by applying Jacquod and Stone prescription, that the EGUE(2)-SU(4) ensemble generates ground state structure just as the quadratic Casimir invariant (C 2 ) of SU(4). This is further corroborated by the calculation of the expectation values of C 2 [SU(4)] and the four periodicity in the ground state energies. Secondly, it is found that the covariances in energy centroids and spectral variances increase in magnitude considerably as we go from EGUE(2) for spinless fermions to EGUE(2) for fermions with spin to EGUE(2)-SU(4) implying that the differences in ensemble and spectral averages grow with increasing symmetry. Also for EGUE(2)-SU(4) there are, unlike for GUE, non-zero cross-correlations in energy centroids and spectral variances defined over spaces with different particle numbers and/or U(Ω) [equivalently SU(4)] irreps. In the dilute limit defined by Ω → ∞, r >> 1 and r/Ω → 0, for the {4 r , p} irreps, we have derived analytical

State energy price and expenditure report 1994

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-06-01

The State Energy Price and Expenditure Report (SEPER) presents energy price and expenditure estimates individually for the 50 States and the District of Columbia and in aggregate for the United States. The price and expenditure estimates developed in the State Energy Price and Expenditure Data System (SEPEDS) are provided by energy source and economic sector and are published for the years 1970 through 1994. Consumption estimates used to calculate expenditures and the documentation for those estimates are taken from the State Energy Data Report 1994, Consumption Estimates (SEDR), published in October 1996. Expenditures are calculated by multiplying the price estimates by the consumption estimates, which are adjusted to remove process fuel; intermediate petroleum products; and other consumption that has no direct fuel costs, i.e., hydroelectric, geothermal, wind, solar, and photovoltaic energy sources. Documentation is included describing the development of price estimates, data sources, and calculation methods. 316 tabs.

State energy price and expenditure report 1994

International Nuclear Information System (INIS)

1997-06-01

The State Energy Price and Expenditure Report (SEPER) presents energy price and expenditure estimates individually for the 50 States and the District of Columbia and in aggregate for the United States. The price and expenditure estimates developed in the State Energy Price and Expenditure Data System (SEPEDS) are provided by energy source and economic sector and are published for the years 1970 through 1994. Consumption estimates used to calculate expenditures and the documentation for those estimates are taken from the State Energy Data Report 1994, Consumption Estimates (SEDR), published in October 1996. Expenditures are calculated by multiplying the price estimates by the consumption estimates, which are adjusted to remove process fuel; intermediate petroleum products; and other consumption that has no direct fuel costs, i.e., hydroelectric, geothermal, wind, solar, and photovoltaic energy sources. Documentation is included describing the development of price estimates, data sources, and calculation methods. 316 tabs

State Energy Program Results: More Projects That Work

Energy Technology Data Exchange (ETDEWEB)

1998-12-01

A Summary of Success stories of the State Energy Programs. The goal of the State Energy Program is to strengthen the capabilities of States to promote energy efficiency and to adopt renewable energy technologies, thereby helping the nation save energy and realize a stronger economy, cleaner environment, and a more secure future.

Aerial radiological survey of the United States Department of Energy's Pantex Plant and surrounding area Amarillo, Texas. Date of survey: October 1979

International Nuclear Information System (INIS)

Boyns, P.K.

1981-07-01

An aerial radiological survey was conducted over the United States Department of Energy's Pantex Plant and Pantex Lake areas in October, 1979. The Pantex Plant survey covered an area of approximately 64 km 2 . The Pantex Lake survey area was approximately 2 km 2 . Both areas were surveyed at an altitude of 46 m (150 feet) with lines spaced at 91 m (300 foot) intervals. Several passes were also made over the shipping areas at the Amarillo International Airport. An array of sodium iodide detectors were mounted in a helicopter to collect gamma ray spectral data. As expected, the spectral data indicated the presence of several areas containing man-made sources

State energy-price system: 1981 update

Energy Technology Data Exchange (ETDEWEB)

Fang, J.M.; Imhoff, K.L.; Hood, L.J.

1983-08-01

This report updates the State Energy Price Data System (STEPS) to include state-level energy prices by fuel and by end-use sectors for 1981. Both physical unit prices and Btu prices are presented. Basic documentation of the data base remains generally the same as in the original report: State Energy Price System; Volume 1: Overview and Technical Documentation (DOE/NBB-0029 Volume 1 of 2, November 1982). The present report documents only the changes in procedures necessitated by the update to 1981 and the corrections to the basic documentation.

Enhancement of nonlinear optical response of weakly confined excitons in GaAs thin films by spectrally rectangle-shape-pulse-excitation

International Nuclear Information System (INIS)

Kojima, O; Isu, T; Ishi-Hayase, J; Sasaki, M; Tsuchiya, M

2007-01-01

We report the enhancement of the nonlinear optical response of the weakly confined excitons with use of spectrally rectangular pulse. The nonlinear optical response was investigated as a function of excitation energy by a degenerate four-wave-mixing (DFWM) technique. In the case that the laser pulse with the controlled spectral shape excites the plural exciton states simultaneously, the DFWM signal intensity is enhanced by a factor of two in comparison with the intensity under the excitation of a single exciton state. This enhancement is caused by the superposition of the nonlinear optical responses from the plural exciton states

Energy Efficiency/Renewable Energy Programs in State Implementation Plans - Guidance Documents

Science.gov (United States)

final document that provides guidance to States and local areas on quantifying and including emission reductions from energy efficiency and renewable energy measures in State Implementation Plans (SIPS).

Experimental determination of spectral ratios and of neutrons energy spectrum in the fuel of the IPEN/MB-01 nuclear reactor

International Nuclear Information System (INIS)

Nunes, Beatriz Guimaraes

2012-01-01

This study aims to determine the spectral ratios and the neutron energy spectrum inside the fuel of IPEN/MB-01 Nuclear Reactor. These parameters are of great importance to accurately determine spectral physical parameters of nuclear reactors like reaction rates, fuel lifetime and also security parameters such as reactivity. For the experiment, activation detectors in the form of thin metal foils were introduced in a collapsible fuel rod. Then the rod was placed in the central position of the core which has a standard rectangular configuration of 26 x 28 fuel rods. There were used activation detectors from different elements such Au-197, U-238, Sc-45, Ni-58, Mg-24, Ti-47 and In-115 to cover a large range of the neutron energy spectrum. After the irradiation, the activation detectors were submitted to gamma spectrometry using a counting system with high purity Germanium, to obtain the reaction rates (saturation activity) per target nucleus. The spectral ratios were compared with calculated values obtained by the Monte Carlo method using the MCNP-4C code. The neutron energy spectrum was obtained inside the fuel rod using the SANDBP code with an input spectrum obtained by the MCNP-4C code, based on the saturation activity per target nucleus values of the activation detectors irradiated. (author)

Guided-wave approaches to spectrally selective energy absorption

Science.gov (United States)

Stegeman, G. I.; Burke, J. J.

1987-01-01

Results of experiments designed to demonstrate spectrally selective absorption in dielectric waveguides on semiconductor substrates are reported. These experiments were conducted with three waveguides formed by sputtering films of PSK2 glass onto silicon-oxide layers grown on silicon substrates. The three waveguide samples were studied at 633 and 532 nm. The samples differed only in the thickness of the silicon-oxide layer, specifically 256 nm, 506 nm, and 740 nm. Agreement between theoretical predictions and measurements of propagation constants (mode angles) of the six or seven modes supported by these samples was excellent. However, the loss measurements were inconclusive because of high scattering losses in the structures fabricated (in excess of 10 dB/cm). Theoretical calculations indicated that the power distribution among all the modes supported by these structures will reach its steady state value after a propagation length of only 1 mm. Accordingly, the measured loss rates were found to be almost independent of which mode was initially excited. The excellent agreement between theory and experiment leads to the conclusion that low loss waveguides confirm the predicted loss rates.

Spectral properties of minimal-basis-set orbitals: Implications for molecular electronic continuum states

Science.gov (United States)

Langhoff, P. W.; Winstead, C. L.

Early studies of the electronically excited states of molecules by John A. Pople and coworkers employing ab initio single-excitation configuration interaction (SECI) calculations helped to simulate related applications of these methods to the partial-channel photoionization cross sections of polyatomic molecules. The Gaussian representations of molecular orbitals adopted by Pople and coworkers can describe SECI continuum states when sufficiently large basis sets are employed. Minimal-basis virtual Fock orbitals stabilized in the continuous portions of such SECI spectra are generally associated with strong photoionization resonances. The spectral attributes of these resonance orbitals are illustrated here by revisiting previously reported experimental and theoretical studies of molecular formaldehyde (H2CO) in combination with recently calculated continuum orbital amplitudes.

Spectral and Energy Efficiencies in mmWave Cellular Networks for Optimal Utilization

Directory of Open Access Journals (Sweden)

Abdulbaset M. Hamed

2018-01-01

Full Text Available Millimeter wave (mmWave spectrum has been proposed for use in commercial cellular networks to relieve the already severely congested microwave spectrum. Thus, the design of an efficient mmWave cellular network has gained considerable importance and has to take into account regulations imposed by government agencies with regard to global warming and sustainable development. In this paper, a dense mmWave hexagonal cellular network with each cell consisting of a number of smaller cells with their own Base Stations (BSs is presented as a solution to meet the increasing demand for a variety of high data rate services and growing number of users of cellular networks. Since spectrum and power are critical resources in the design of such a network, a framework is presented that addresses efficient utilization of these resources in mmWave cellular networks in the 28 and 73 GHz bands. These bands are already an integral part of well-known standards such as IEEE 802.15.3c, IEEE 802.11ad, and IEEE 802.16.1. In the analysis, a well-known accurate mmWave channel model for Line of Sight (LOS and Non-Line of Sight (NLOS links is used. The cellular network is analyzed in terms of spectral efficiency, bit/s, energy efficiency, bit/J, area spectral efficiency, bit/s/m2, area energy efficiency, bit/J/m2, and network latency, s/bit. These efficiency metrics are illustrated, using Monte Carlo simulation, as a function of Signal-to-Noise Ratio (SNR, channel model parameters, user distance from BS, and BS transmission power. The efficiency metrics for optimum deployment of cellular networks in 28 and 73 GHz bands are identified. Results show that 73 GHz band achieves better spectrum efficiency and the 28 GHz band is superior in terms of energy efficiency. It is observed that while the latter band is expedient for indoor networks, the former band is appropriate for outdoor networks.

Clean energy funds: An overview of state support for renewable energy

Energy Technology Data Exchange (ETDEWEB)

Bolinger, Mark; Wiser, Ryan

2001-04-01

Across the United States, as competition in the supply and delivery of electricity has been introduced, states have sought to ensure the continuation of ''public benefits'' programs traditionally administered or funded by electric utilities. Many states have built into their restructuring plans methods of supporting renewable energy sources. One of the most popular policy mechanisms for ensuring such continued support has been the system-benefits charge (SBC), a non-bypassable charge to electricity customers (usually applied on a cents/kWh basis) used to collect funds for public purpose programs. Thus far, at least fourteen states have established SBC funds targeted in part towards renewable energy. This paper discusses the status and performance of these state renewable or ''clean'' energy funds supported by system-benefits charges. As illustrated later, existing state renewable energy funds are expected to collect roughly $3.5 billion through 2012 for renewable energy. Clearly, these funds have the potential to provide significant support for clean energy technologies over at least the next decade. Because the level of funding for renewable energy available under these programs is unprecedented and because fund administrators are developing innovative and new programs to fund renewable projects, a certain number of program failures are unavoidable. Also evident is that states are taking very different approaches to the distribution of these funds and that many lessons are being learned as programs are designed, implemented, and evaluated. Our purpose in this paper is therefore to relay early experience with these funds and provide preliminary lessons learned from that experience. It is our hope that this analysis will facilitate learning across states and help state fund managers develop more effective and more coordinated programs. Central to this paper are case studies that provide information on the SBC-funded renewable

States of low energy on Robertson-Walker spacetimes

International Nuclear Information System (INIS)

Olbermann, Heiner

2007-01-01

We construct a new class of physical states of the free Klein-Gordon field in Robertson-Walker spacetimes. This is done by minimizing the expectation value of smeared stress-energy. We get an explicit expression for the state depending on the smearing function. We call it a state of low energy. States of low energy are an improvement of the concept of adiabatic vacua on Robertson-Walker spacetimes. The latter are approximations of the former. It is shown that states of low energy are Hadamard states

THE ULTRAVIOLET-TO-MID-INFRARED SPECTRAL ENERGY DISTRIBUTION OF WEAK EMISSION LINE QUASARS

International Nuclear Information System (INIS)

Lane, Ryan A.; Shemmer, Ohad; Diamond-Stanic, Aleksandar M.; Fan Xiaohui; Anderson, Scott F.; Brandt, W. N.; Schneider, Donald P.; Plotkin, Richard M.; Richards, Gordon T.; Strauss, Michael A.

2011-01-01

We present Spitzer Space Telescope photometry of 18 Sloan Digital Sky Survey (SDSS) quasars at 2.7 ≤ z ≤ 5.9 which have weak or undetectable high-ionization emission lines in their rest-frame ultraviolet (UV) spectra (hereafter weak-lined quasars, or WLQs). The Spitzer data are combined with SDSS spectra and ground-based, near-infrared (IR) photometry of these sources to produce a large inventory of spectral energy distributions (SEDs) of WLQs across the rest-frame ∼0.1-5 μm spectral band. The SEDs of our sources are inconsistent with those of BL Lacertae objects which are dominated by synchrotron emission due to a jet aligned close to our line of sight, but are consistent with the SED of ordinary quasars with similar luminosities and redshifts that exhibit a near-to-mid-IR 'bump', characteristic of hot dust emission. This indicates that broad emission lines in WLQs are intrinsically weak, rather than suffering continuum dilution from a jet, and that such sources cannot be selected efficiently from traditional photometric surveys.

THE ULTRAVIOLET-TO-MID-INFRARED SPECTRAL ENERGY DISTRIBUTION OF WEAK EMISSION LINE QUASARS

Energy Technology Data Exchange (ETDEWEB)

Lane, Ryan A.; Shemmer, Ohad [Department of Physics, University of North Texas, Denton, TX 76203 (United States); Diamond-Stanic, Aleksandar M. [Center for Astrophysics and Space Sciences, University of California, San Diego, La Jolla, CA 92093 (United States); Fan Xiaohui [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Anderson, Scott F. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Brandt, W. N.; Schneider, Donald P. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Plotkin, Richard M. [Astronomical Institute ' Anton Pannekoek' , University of Amsterdam, Science Park 904, NL-1098 XH Amsterdam (Netherlands); Richards, Gordon T. [Department of Physics, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Strauss, Michael A., E-mail: RyanLane@my.unt.edu, E-mail: ohad@unt.edu [Princeton University Observatory, Peyton Hall, Princeton, NJ 08544 (United States)

2011-12-20

We present Spitzer Space Telescope photometry of 18 Sloan Digital Sky Survey (SDSS) quasars at 2.7 {<=} z {<=} 5.9 which have weak or undetectable high-ionization emission lines in their rest-frame ultraviolet (UV) spectra (hereafter weak-lined quasars, or WLQs). The Spitzer data are combined with SDSS spectra and ground-based, near-infrared (IR) photometry of these sources to produce a large inventory of spectral energy distributions (SEDs) of WLQs across the rest-frame {approx}0.1-5 {mu}m spectral band. The SEDs of our sources are inconsistent with those of BL Lacertae objects which are dominated by synchrotron emission due to a jet aligned close to our line of sight, but are consistent with the SED of ordinary quasars with similar luminosities and redshifts that exhibit a near-to-mid-IR 'bump', characteristic of hot dust emission. This indicates that broad emission lines in WLQs are intrinsically weak, rather than suffering continuum dilution from a jet, and that such sources cannot be selected efficiently from traditional photometric surveys.

Area Spectral Efficiency and Energy Efficiency Tradeoff in Ultradense Heterogeneous Networks

Directory of Open Access Journals (Sweden)

Lanhua Xiang

2017-01-01

Full Text Available In order to meet the demand of explosive data traffic, ultradense base station (BS deployment in heterogeneous networks (HetNets as a key technique in 5G has been proposed. However, with the increment of BSs, the total energy consumption will also increase. So, the energy efficiency (EE has become a focal point in ultradense HetNets. In this paper, we take the area spectral efficiency (ASE into consideration and focus on the tradeoff between the ASE and EE in an ultradense HetNet. The distributions of BSs in the two-tier ultradense HetNet are modeled by two independent Poisson point processes (PPPs and the expressions of ASE and EE are derived by using the stochastic geometry tool. The tradeoff between the ASE and EE is formulated as a constrained optimization problem in which the EE is maximized under the ASE constraint, through optimizing the BS densities. It is difficult to solve the optimization problem analytically, because the closed-form expressions of ASE and EE are not easily obtained. Therefore, simulations are conducted to find optimal BS densities.

Observer model optimization of a spectral mammography system

Science.gov (United States)

Fredenberg, Erik; Åslund, Magnus; Cederström, Björn; Lundqvist, Mats; Danielsson, Mats

2010-04-01

Spectral imaging is a method in medical x-ray imaging to extract information about the object constituents by the material-specific energy dependence of x-ray attenuation. Contrast-enhanced spectral imaging has been thoroughly investigated, but unenhanced imaging may be more useful because it comes as a bonus to the conventional non-energy-resolved absorption image at screening; there is no additional radiation dose and no need for contrast medium. We have used a previously developed theoretical framework and system model that include quantum and anatomical noise to characterize the performance of a photon-counting spectral mammography system with two energy bins for unenhanced imaging. The theoretical framework was validated with synthesized images. Optimal combination of the energy-resolved images for detecting large unenhanced tumors corresponded closely, but not exactly, to minimization of the anatomical noise, which is commonly referred to as energy subtraction. In that case, an ideal-observer detectability index could be improved close to 50% compared to absorption imaging. Optimization with respect to the signal-to-quantum-noise ratio, commonly referred to as energy weighting, deteriorated detectability. For small microcalcifications or tumors on uniform backgrounds, however, energy subtraction was suboptimal whereas energy weighting provided a minute improvement. The performance was largely independent of beam quality, detector energy resolution, and bin count fraction. It is clear that inclusion of anatomical noise and imaging task in spectral optimization may yield completely different results than an analysis based solely on quantum noise.

State energy price and expenditure report, 1995

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-08-01

The State Energy Price and Expenditure Report (SEPER) presents energy price and expenditure estimates individually for the 50 States and the District of Columbia and in aggregate for the US. The estimates developed in the State Energy Price and Expenditure Data System (SEPEDS) are provided by energy source and economic sector and are published for the years 1970 through 1995. Data for all years are available on a CD-ROM and via Internet. Consumption estimates used to calculate expenditures and the documentation for those estimates are taken from the State Energy Data Report 1995, Consumption Estimates (SEDR), published in December 1997. Expenditures are calculated by multiplying the price estimates by the consumption estimates, which are adjusted to remove process fuel; intermediate petroleum products; and other consumption that has no direct fuel costs, i.e., hydroelectric, geothermal, wind, solar, and photovoltaic energy sources.

The TDF System for Thermonuclear Plasma Reaction Rates, Mean Energies and Two-Body Final State Particle Spectra

International Nuclear Information System (INIS)

Warshaw, S I

2001-01-01

The rate of thermonuclear reactions in hot plasmas as a function of local plasma temperature determines the way in which thermonuclear ignition and burning proceeds in the plasma. The conventional model approach to calculating these rates is to assume that the reacting nuclei in the plasma are in Maxwellian equilibrium at some well-defined plasma temperature, over which the statistical average of the reaction rate quantity σv is calculated, where σ is the cross-section for the reaction to proceed at the relative velocity v between the reacting particles. This approach is well-understood and is the basis for much nuclear fusion and astrophysical nuclear reaction rate data. The Thermonuclear Data File (TDF) system developed at the Lawrence Livermore National Laboratory (Warshaw 1991), which is the topic of this report, contains data on the Maxwellian-averaged thermonuclear reaction rates for various light nuclear reactions and the correspondingly Maxwellian-averaged energy spectra of the particles in the final state of those reactions as well. This spectral information closely models the output particle and energy distributions in a burning plasma, and therefore leads to more accurate computational treatments of thermonuclear burn, output particle energy deposition and diagnostics, in various contexts. In this report we review and derive the theoretical basis for calculating Maxwellian-averaged thermonuclear reaction rates, mean particle energies, and output particle spectral energy distributions for these reactions in the TDF system. The treatment of the kinematics is non-relativistic. The current version of the TDF system provides exit particle energy spectrum distributions for two-body final state reactions only. In a future report we will discuss and describe how output particle energy spectra for three- and four-body final states can be developed for the TDF system. We also include in this report a description of the algorithmic implementation of the TDF

Accuracy of Stated Energy Contents of Restaurant Foods

Science.gov (United States)

Urban, Lorien E.; McCrory, Megan A.; Dallal, Gerard E.; Das, Sai Krupa; Saltzman, Edward; Weber, Judith L.; Roberts, Susan B.

2015-01-01

Context National recommendations for the prevention and treatment of obesity emphasize reducing energy intake. Foods purchased in restaurants provide approximately 35% of the daily energy intake in US individuals but the accuracy of the energy contents listed for these foods is unknown. Objective To examine the accuracy of stated energy contents of foods purchased in restaurants. Design and Setting A validated bomb calorimetry technique was used to measure dietary energy in food from 42 restaurants, comprising 269 total food items and 242 unique foods. The restaurants and foods were randomly selected from quick-serve and sit-down restaurants in Massachusetts, Arkansas, and Indiana between January and June 2010. Main Outcome Measure The difference between restaurant-stated and laboratory-measured energy contents, which were corrected for standard metabolizable energy conversion factors. Results The absolute stated energy contents were not significantly different from the absolute measured energy contents overall (difference of 10 kcal/portion; 95% confidence interval [CI], −15 to 34 kcal/portion; P=.52); however, the stated energy contents of individual foods were variable relative to the measured energy contents. Of the 269 food items, 50 (19%) contained measured energy contents of at least 100 kcal/portion more than the stated energy contents. Of the 10% of foods with the highest excess energy in the initial sampling, 13 of 17 were available for a second sampling. In the first analysis, these foods contained average measured energy contents of 289 kcal/portion (95% CI, 186 to 392 kcal/portion) more than the stated energy contents; in the second analysis, these foods contained average measured energy contents of 258 kcal/portion (95% CI, 154 to 361 kcal/portion) more than the stated energy contents (Prestaurant foods were accurate overall. However, there was substantial inaccuracy for some individual foods, with understated energy contents for those with lower

Nanoscale probing of bandgap states on oxide particles using electron energy-loss spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Liu, Qianlang [School for the Engineering of Matter, Transport and Energy, Arizona State University, 85287 AZ (United States); March, Katia [Laboratoire de Physique des Solides, Bâtiment 510, Université Paris-Sud, 91405 Orsay Cedex (France); Crozier, Peter A., E-mail: CROZIER@asu.edu [School for the Engineering of Matter, Transport and Energy, Arizona State University, 85287 AZ (United States)

2017-07-15

Surface and near-surface electronic states were probed with nanometer spatial resolution in MgO and TiO{sub 2} anatase nanoparticles using ultra-high energy resolution electron energy-loss spectroscopy (EELS) coupled to a scanning transmission electron microscope (STEM). This combination allows the surface electronic structure determined with spectroscopy to be correlated with nanoparticle size, morphology, facet etc. By acquiring the spectra in aloof beam mode, radiation damage to the surface can be significantly reduced while maintaining the nanometer spatial resolution. MgO and TiO{sub 2} showed very different bandgap features associated with the surface/sub-surface layer of the nanoparticles. Spectral simulations based on dielectric theory and density of states models showed that a plateau feature found in the pre-bandgap region in the spectra from (100) surfaces of 60 nm MgO nanocubes is consistent with a thin hydroxide surface layer. The spectroscopy shows that this hydroxide species gives rise to a broad filled surface state at 1.1 eV above the MgO valence band. At the surfaces of TiO{sub 2} nanoparticles, pronounced peaks were observed in the bandgap region, which could not be well fitted to defect states. In this case, the high refractive index and large particle size may make Cherenkov or guided light modes the likely causes of the peaks. - Highlights: • Bandgap states detected with aloof beam monochromated EELS on oxide nanoparticle surfaces. • Dielectric theory applied to simulate the spectra and interpret surface structure. • Density of states models also be employed to understand the surface electronic structure. • In MgO, one states associate with water species was found close to the valence band edge. • In anatase, two mid-gap states associated with point defects were found.

Decaying spectral oscillations in a Majorana wire with finite coherence length

Science.gov (United States)

Fleckenstein, C.; Domínguez, F.; Traverso Ziani, N.; Trauzettel, B.

2018-04-01

Motivated by recent experiments, we investigate the excitation energy of a proximitized Rashba wire in the presence of a position dependent pairing. In particular, we focus on the spectroscopic pattern produced by the overlap between two Majorana bound states that appear for values of the Zeeman field smaller than the value necessary for reaching the bulk topological superconducting phase. The two Majorana bound states can arise because locally the wire is in the topological regime. We find three parameter ranges with different spectral properties: crossings, anticrossings, and asymptotic reduction of the energy as a function of the applied Zeeman field. Interestingly, all these cases have already been observed experimentally. Moreover, since an increment of the magnetic field implies the increase of the distance between the Majorana bound states, the amplitude of the energy oscillations, when present, gets reduced. The existence of the different Majorana scenarios crucially relies on the fact that the two Majorana bound states have distinct k -space structures. We develop analytical models that clearly explain the microscopic origin of the predicted behavior.

Total spectral distributions from Hawking radiation

Energy Technology Data Exchange (ETDEWEB)

Broda, Boguslaw [University of Lodz, Department of Theoretical Physics, Faculty of Physics and Applied Informatics, Lodz (Poland)

2017-11-15

Taking into account the time dependence of the Hawking temperature and finite evaporation time of the black hole, the total spectral distributions of the radiant energy and of the number of particles have been explicitly calculated and compared to their temporary (initial) blackbody counterparts (spectral exitances). (orig.)

Single-energy pediatric chest computed tomography with spectral filtration at 100 kVp: effects on radiation parameters and image quality

Energy Technology Data Exchange (ETDEWEB)

Bodelle, Boris; Fischbach, Constanze; Booz, Christian; Yel, Ibrahim; Frellesen, Claudia; Kaup, Moritz; Beeres, Martin; Vogl, Thomas J.; Scholtz, Jan-Erik [Goethe University of Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany)

2017-06-15

Most of the applied radiation dose at CT is in the lower photon energy range, which is of limited diagnostic importance. To investigate image quality and effects on radiation parameters of 100-kVp spectral filtration single-energy chest CT using a tin-filter at third-generation dual-source CT in comparison to standard 100-kVp chest CT. Thirty-three children referred for a non-contrast chest CT performed on a third-generation dual-source CT scanner were examined at 100 kVp with a dedicated tin filter with a tube current-time product resulting in standard protocol dose. We compared resulting images with images from children examined using standard single-source chest CT at 100 kVp. We assessed objective and subjective image quality and compared radiation dose parameters. Radiation dose was comparable for children 5 years old and younger, and it was moderately decreased for older children when using spectral filtration (P=0.006). Effective tube current increased significantly (P=0.0001) with spectral filtration, up to a factor of 10. Signal-to-noise ratio and image noise were similar for both examination techniques (P≥0.06). Subjective image quality showed no significant differences (P≥0.2). Using 100-kVp spectral filtration chest CT in children by means of a tube-based tin-filter on a third-generation dual-source CT scanner increases effective tube current up to a factor of 10 to provide similar image quality at equivalent dose compared to standard single-source CT without spectral filtration. (orig.)

Single-energy pediatric chest computed tomography with spectral filtration at 100 kVp: effects on radiation parameters and image quality

International Nuclear Information System (INIS)

Bodelle, Boris; Fischbach, Constanze; Booz, Christian; Yel, Ibrahim; Frellesen, Claudia; Kaup, Moritz; Beeres, Martin; Vogl, Thomas J.; Scholtz, Jan-Erik

2017-01-01

Most of the applied radiation dose at CT is in the lower photon energy range, which is of limited diagnostic importance. To investigate image quality and effects on radiation parameters of 100-kVp spectral filtration single-energy chest CT using a tin-filter at third-generation dual-source CT in comparison to standard 100-kVp chest CT. Thirty-three children referred for a non-contrast chest CT performed on a third-generation dual-source CT scanner were examined at 100 kVp with a dedicated tin filter with a tube current-time product resulting in standard protocol dose. We compared resulting images with images from children examined using standard single-source chest CT at 100 kVp. We assessed objective and subjective image quality and compared radiation dose parameters. Radiation dose was comparable for children 5 years old and younger, and it was moderately decreased for older children when using spectral filtration (P=0.006). Effective tube current increased significantly (P=0.0001) with spectral filtration, up to a factor of 10. Signal-to-noise ratio and image noise were similar for both examination techniques (P≥0.06). Subjective image quality showed no significant differences (P≥0.2). Using 100-kVp spectral filtration chest CT in children by means of a tube-based tin-filter on a third-generation dual-source CT scanner increases effective tube current up to a factor of 10 to provide similar image quality at equivalent dose compared to standard single-source CT without spectral filtration. (orig.)

State energy price and expenditure report 1989

International Nuclear Information System (INIS)

1991-01-01

The State Energy Price and Expenditure Report (SEPER) presents energy price and expenditure estimates for the 50 States, the District of Columbia, and the United States. The estimates are provided by energy source (e.g., petroleum, natural gas, coal, and electricity) and by major consuming or economic sector. This report is an update of the State Energy Price and Expenditure Report 1988 published in September 1990. Changes from the last report are summarized in a section of the documentation. Energy price and expenditure estimates are published for the years 1970, 1975, 1980, and 1985 through 1989. Documentation follows the tables and describes how the price estimates are developed, including sources of data, methods of estimation, and conversion factors applied. Consumption estimates used to calculate expenditures, and the documentation for those estimates, are from the State Energy Data Report, Consumption Estimates, 1960--1989 (SEDR), published in May 1991. Expenditures are calculated by multiplying the price estimates by the consumption estimates, adjusted to remove process fuel and intermediate product consumption. All expenditures are consumer expenditures, that is, they represent estimates of money directly spent by consumers to purchase energy, generally including taxes. 11 figs., 43 tabs

State energy price and expenditure report 1989

Energy Technology Data Exchange (ETDEWEB)

1991-09-30

The State Energy Price and Expenditure Report (SEPER) presents energy price and expenditure estimates for the 50 States, the District of Columbia, and the United States. The estimates are provided by energy source (e.g., petroleum, natural gas, coal, and electricity) and by major consuming or economic sector. This report is an update of the State Energy Price and Expenditure Report 1988 published in September 1990. Changes from the last report are summarized in a section of the documentation. Energy price and expenditure estimates are published for the years 1970, 1975, 1980, and 1985 through 1989. Documentation follows the tables and describes how the price estimates are developed, including sources of data, methods of estimation, and conversion factors applied. Consumption estimates used to calculate expenditures, and the documentation for those estimates, are from the State Energy Data Report, Consumption Estimates, 1960--1989 (SEDR), published in May 1991. Expenditures are calculated by multiplying the price estimates by the consumption estimates, adjusted to remove process fuel and intermediate product consumption. All expenditures are consumer expenditures, that is, they represent estimates of money directly spent by consumers to purchase energy, generally including taxes. 11 figs., 43 tabs.

Renewable energy atlas of the United States.

Energy Technology Data Exchange (ETDEWEB)

Kuiper, J.A.; Hlava, K.Greenwood, H.; Carr, A. (Environmental Science Division)

2012-05-01

The Renewable Energy Atlas (Atlas) of the United States is a compilation of geospatial data focused on renewable energy resources, federal land ownership, and base map reference information. It is designed for the U.S. Department of Agriculture Forest Service (USFS) and other federal land management agencies to evaluate existing and proposed renewable energy projects. Much of the content of the Atlas was compiled at Argonne National Laboratory (Argonne) to support recent and current energy-related Environmental Impact Statements and studies, including the following projects: (1) West-wide Energy Corridor Programmatic Environmental Impact Statement (PEIS) (BLM 2008); (2) Draft PEIS for Solar Energy Development in Six Southwestern States (DOE/BLM 2010); (3) Supplement to the Draft PEIS for Solar Energy Development in Six Southwestern States (DOE/BLM 2011); (4) Upper Great Plains Wind Energy PEIS (WAPA/USFWS 2012, in progress); and (5) Energy Transport Corridors: The Potential Role of Federal Lands in States Identified by the Energy Policy Act of 2005, Section 368(b) (in progress). This report explains how to add the Atlas to your computer and install the associated software; describes each of the components of the Atlas; lists the Geographic Information System (GIS) database content and sources; and provides a brief introduction to the major renewable energy technologies.

Innovation, renewable energy, and state investment: Case studies of leading clean energy funds

Energy Technology Data Exchange (ETDEWEB)

Wiser, Ryan; Bolinger, Mark; Milford, Lewis; Porter, Kevin; Clark, Roger

2002-09-01

Over the last several years, many U.S. states have established clean energy funds to help support the growth of renewable energy markets. Most often funded by system-benefits charges (SBC), the 15 states that have established such funds are slated to collect nearly $3.5 billion from 1998 to 2012 for renewable energy investments. These clean energy funds are expected to have a sizable impact on the energy future of the states in which the funds are being collected and used. For many of the organizations tapped to administer these funds, however, this is a relatively new role that presents the challenge of using public funds in the most effective and innovative fashion possible. Fortunately, each state is not alone in its efforts; many other U.S. states and a number of countries are undertaking similar efforts. Early lessons are beginning to be learned by clean energy funds about how to effectively target public funds towards creating and building renewable energy markets. A number of innovative programs have already been developed that show significant leadership by U.S. states in supporting renewable energy. It is important that clean energy fund administrators learn from this emerging experience.

Spectral sum rules and magneto-roton as emergent graviton in fractional quantum Hall effect

Energy Technology Data Exchange (ETDEWEB)

Golkar, Siavash; Nguyen, Dung X.; Son, Dam T. [Enrico Fermi Institute, James Franck Institute and Department of Physics,University of Chicago, Chicago, Illinois 60637 (United States)

2016-01-05

We consider gapped fractional quantum Hall states on the lowest Landau level when the Coulomb energy is much smaller than the cyclotron energy. We introduce two spectral densities, ρ{sub T}(ω) and ρ̄{sub T}(ω), which are proportional to the probabilities of absorption of circularly polarized gravitons by the quantum Hall system. We prove three sum rules relating these spectral densities with the shift S, the q{sup 4} coefficient of the static structure factor S{sub 4}, and the high-frequency shear modulus of the ground state μ{sub ∞}, which is precisely defined. We confirm an inequality, first suggested by Haldane, that S{sub 4} is bounded from below by |S−1|/8. The Laughlin wavefunction saturates this bound, which we argue to imply that systems with ground state wavefunctions close to Laughlin’s absorb gravitons of predominantly one circular polarization. We consider a nonlinear model where the sum rules are saturated by a single magneto-roton mode. In this model, the magneto-roton arises from the mixing between oscillations of an internal metric and the hydrodynamic motion. Implications for experiments are briefly discussed.

Nonlocal low-rank and sparse matrix decomposition for spectral CT reconstruction

Science.gov (United States)

Niu, Shanzhou; Yu, Gaohang; Ma, Jianhua; Wang, Jing

2018-02-01

Spectral computed tomography (CT) has been a promising technique in research and clinics because of its ability to produce improved energy resolution images with narrow energy bins. However, the narrow energy bin image is often affected by serious quantum noise because of the limited number of photons used in the corresponding energy bin. To address this problem, we present an iterative reconstruction method for spectral CT using nonlocal low-rank and sparse matrix decomposition (NLSMD), which exploits the self-similarity of patches that are collected in multi-energy images. Specifically, each set of patches can be decomposed into a low-rank component and a sparse component, and the low-rank component represents the stationary background over different energy bins, while the sparse component represents the rest of the different spectral features in individual energy bins. Subsequently, an effective alternating optimization algorithm was developed to minimize the associated objective function. To validate and evaluate the NLSMD method, qualitative and quantitative studies were conducted by using simulated and real spectral CT data. Experimental results show that the NLSMD method improves spectral CT images in terms of noise reduction, artifact suppression and resolution preservation.

Spectral Shifting in Nondestructive Assay Instrumentation

Energy Technology Data Exchange (ETDEWEB)

Trellue, Holly Renee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nettleton, Anthony Steven [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tutt, James Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Menlove, Howard Olsen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); LaFleur, Adrienne Marie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tobin, Stephen Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-11-17

This project involves spectrum tailoring research that endeavors to better distinguish energies of gamma rays using different spectral material thicknesses and determine neutron energies by coating detectors with various materials.

Factors of Renewable Energy Deployment and Empirical Studies of United States Wind Energy

Science.gov (United States)

Can Sener, Serife Elif

Considered essential for countries' development, energy demand is growing worldwide. Unlike conventional sources, the use of renewable energy sources has multiple benefits, including increased energy security, sustainable economic growth, and pollution reduction, in particular greenhouse gas emissions. Nevertheless, there is a considerable difference in the share of renewable energy sources in national energy portfolios. This dissertation contains a series of studies to provide an outlook on the existing renewable energy deployment literature and empirically identify the factors of wind energy generation capacity and wind energy policy diffusion in the U.S. The dissertation begins with a systematic literature review to identify drivers and barriers which could help in understanding the diverging paths of renewable energy deployment for countries. In the analysis, economic, environmental, and social factors are found to be drivers, whereas political, regulatory, technical potential and technological factors are not classified as either a driver or a barrier (i.e., undetermined). Each main category contains several subcategories, among which only national income is found to have a positive impact, whereas all other subcategories are considered undetermined. No significant barriers to the deployment of renewable energy sources are found over the analyzed period. Wind energy deployment within the states related to environmental and economic factors was seldom discussed in the literature. The second study of the dissertation is thus focused on the wind energy deployment in the United States. Wind energy is among the most promising clean energy sources and the United States has led the world in per capita newly installed generation capacity since 2000. In the second study, using a fixed-effects panel data regression analysis, the significance of a number of economic and environmental factors are investigated for 39 states from 2000 to 2015. The results suggested that the

The troposphere-to-stratosphere transition in kinetic energy spectra and nonlinear spectral fluxes as seen in ECMWF analyses

Science.gov (United States)

Burgess, A. B. H.; Erler, A. R.; Shepherd, T. G.

2012-04-01

We present spectra, nonlinear interaction terms, and fluxes computed for horizontal wind fields from high-resolution meteorological analyses made available by ECMWF for the International Polar Year. Total kinetic energy spectra clearly show two spectral regimes: a steep spectrum at large scales and a shallow spectrum in the mesoscale. The spectral shallowing appears at ~200 hPa, and is due to decreasing rotational power with height, which results in the shallower divergent spectrum dominating in the mesoscale. The spectra we find are steeper than those observed in aircraft data and GCM simulations. Though the analyses resolve total spherical harmonic wavenumbers up to n = 721, effects of dissipation on the fluxes and spectra are visible starting at about n = 200. We find a weak forward energy cascade and a downscale enstrophy cascade in the mesoscale. Eddy-eddy nonlinear kinetic energy transfers reach maximum amplitudes at the tropopause, and decrease with height thereafter; zonal mean-eddy transfers dominate in the stratosphere. In addition, zonal anisotropy reaches a minimum at the tropopause. Combined with strong eddy-eddy interactions, this suggests flow in the tropopause region is very active and bears the greatest resemblance to isotropic turbulence. We find constant enstrophy flux over a broad range of wavenumbers around the tropopause and in the upper stratosphere. A relatively constant spectral enstrophy flux at the tropopause suggests a turbulent inertial range, and that the enstrophy flux is resolved. A main result of our work is its implications for explaining the shallow mesoscale spectrum observed in aircraft wind measurements, GCM studies, and now meteorological analyses. The strong divergent component in the shallow mesoscale spectrum indicates unbalanced flow, and nonlinear transfers decreasing quickly with height are characteristic of waves, not turbulence. Together with the downscale flux of energ y through the shallow spectral range, these

Spectral distribution study of nuclei in 2p-1f shell

International Nuclear Information System (INIS)

Haq, R.; Parikh, J.C.

1975-01-01

Systematics of nuclei in the beginning of fp-shell are investigated using the spectral distribution method of French. The centroid energies and widths for various distributions are evaluated using the interaction of Kuo with the modification suggested by McGrory et al. The two moment distributions are used to determine ground state energies, fractional occupancy of the single particle orbits for ground states and low lying spectra of various nuclei in this shell. The results are compared with the deformed configuration mixing calculations of Dhar et al. The goodness of Wigner SU(4) symmetry in these nuclei has been investigated. The mixing of various SU(4) representations near the ground state provides a measure of symmetry mixing and the substantial admixture in most of the cases shows that it is badly broken, largely due to the single particle spin orbit coupling. (author)

Building Stronger State Energy Partnerships with the U.S. Department of Energy

Energy Technology Data Exchange (ETDEWEB)

Marks, Kate

2011-09-30

This final technical report details the results of total work efforts and progress made from October 2007 – September 2011 under the National Association of State Energy Officials (NASEO) cooperative agreement DE-FC26-07NT43264, Building Stronger State Energy Partnerships with the U.S. Department of Energy. Major topical project areas in this final report include work efforts in the following areas: Energy Assurance and Critical Infrastructure, State and Regional Technical Assistance, Regional Initiative, Regional Coordination and Technical Assistance, and International Activities in China. All required deliverables have been provided to the National Energy Technology Laboratory and DOE program officials.

On Pythagoras Theorem for Products of Spectral Triples

OpenAIRE

D'Andrea, Francesco; Martinetti, Pierre

2013-01-01

We discuss a version of Pythagoras theorem in noncommutative geometry. Usual Pythagoras theorem can be formulated in terms of Connes' distance, between pure states, in the product of commutative spectral triples. We investigate the generalization to both non pure states and arbitrary spectral triples. We show that Pythagoras theorem is replaced by some Pythagoras inequalities, that we prove for the product of arbitrary (i.e. non-necessarily commutative) spectral triples, assuming only some un...

Measurement of Spectral Functions of Ultracold Atoms in Disordered Potentials

Science.gov (United States)

Volchkov, Valentin V.; Pasek, Michael; Denechaud, Vincent; Mukhtar, Musawwadah; Aspect, Alain; Delande, Dominique; Josse, Vincent

2018-02-01

We report on the measurement of the spectral functions of noninteracting ultracold atoms in a three-dimensional disordered potential resulting from an optical speckle field. Varying the disorder strength by 2 orders of magnitude, we observe the crossover from the "quantum" perturbative regime of low disorder to the "classical" regime at higher disorder strength, and find an excellent agreement with numerical simulations. The method relies on the use of state-dependent disorder and the controlled transfer of atoms to create well-defined energy states. This opens new avenues for experimental investigations of three-dimensional Anderson localization.

Silicon Nanowires for Solar Thermal Energy Harvesting: an Experimental Evaluation on the Trade-off Effects of the Spectral Optical Properties.

Science.gov (United States)

Sekone, Abdoul Karim; Chen, Yu-Bin; Lu, Ming-Chang; Chen, Wen-Kai; Liu, Chia-An; Lee, Ming-Tsang

2016-12-01

Silicon nanowire possesses great potential as the material for renewable energy harvesting and conversion. The significantly reduced spectral reflectivity of silicon nanowire to visible light makes it even more attractive in solar energy applications. However, the benefit of its use for solar thermal energy harvesting remains to be investigated and has so far not been clearly reported. The purpose of this study is to provide practical information and insight into the performance of silicon nanowires in solar thermal energy conversion systems. Spectral hemispherical reflectivity and transmissivity of the black silicon nanowire array on silicon wafer substrate were measured. It was observed that the reflectivity is lower in the visible range but higher in the infrared range compared to the plain silicon wafer. A drying experiment and a theoretical calculation were carried out to directly evaluate the effects of the trade-off between scattering properties at different wavelengths. It is clearly seen that silicon nanowires can improve the solar thermal energy harnessing. The results showed that a 17.8 % increase in the harvest and utilization of solar thermal energy could be achieved using a silicon nanowire array on silicon substrate as compared to that obtained with a plain silicon wafer.

State of Oregon 4th biennial energy plan

International Nuclear Information System (INIS)

Anon.

1991-01-01

State law directs the Oregon Department of Energy (ODOE) to prepare an energy plan every two years. This is the Fourth Biennial Energy Plan. The Plan is a policy blueprint for how to best meet Oregon's future energy needs. It identifies the key energy issues facing the state and sets forth policies and actions to achieve our energy goals of reliable, least-cost, and environmentally safe supply. This book presents: Oregon's demand and supply picture today. The progress Oregon has made toward energy efficiency. Oregon's energy demand and supply outlook for the next 20 years. Estimates of cost-effective conservation and other resources that could contribute to the state's energy supply. The major energy-related health, safety, and environmental issues facing the state. A strategy to reduce greenhouse gas emissions 20 percent from 1988 levels by 2005. A two-year Action Plant that spells out ODOE's recommended actions for achieving Oregon's energy goals

X-Ray Spectral Characteristics of Ginga Gamma-Ray Bursts

International Nuclear Information System (INIS)

Strohmayer, T.E.; Fenimore, E.E.; Murakami, T.; Yoshida, A.

1998-01-01

We have investigated the spectral characteristics of a sample of bright gamma-ray bursts detected with the gamma-ray burst sensors aboard the satellite Ginga. This instrument employed a proportional and scintillation counter to provide sensitivity to photons in the 2 endash 400 keV region and as such provided a unique opportunity to characterize the largely unexplored X-ray properties of gamma-ray bursts. The photon spectra of the Ginga bursts are well described by a low-energy slope, a bend energy, and a high-energy slope. In the energy range where they can be compared, this result is consistent with burst spectral analyses obtained from the BATSE experiment aboard the Compton Gamma-Ray Observatory. However, below 20 keV we find evidence for a positive spectral number index in approximately 40% of our burst sample, with some evidence for a strong rolloff at lower energies in a few events. There is a correlation (Pearson's r = -0.62) between the low-energy slope and the bend energy. We find that the distribution of spectral bend energies extends below 10 keV. There has been some concern in cosmological models of gamma-ray bursts (GRBs) that the bend energy covers only a small dynamic range. Our result extends the observed dynamic range, and, since we observe bend energies down to the limit of our instrument, perhaps observations have not yet limited the range. The Ginga trigger range was virtually the same as that of BATSE, yet we find a different range of fit parameters. One possible explanation might be that GRBs have two break energies, one often in the 50 endash 500 keV range and the other near 5 keV. Both BATSE and Ginga fit with only a single break energy, so BATSE tends to find breaks near the center of its energy range, and we tend to find breaks in our energy range. The observed ratio of energy emitted in the X-rays relative to the gamma rays can be much larger than a few percent and, in fact, is sometimes larger than unity. The average for our 22 bursts

State Energy Efficiency Benefits and Opportunities

Science.gov (United States)

Describes the benefits of energy efficiency and how to assess its potential for your state. Also, find details on energy efficiency policies, programs, and resources available for furthering energy efficiency goals.

Energy landscapes of resting-state brain networks

Directory of Open Access Journals (Sweden)

Takamitsu eWatanabe

2014-02-01

Full Text Available During rest, the human brain performs essential functions such as memory maintenance, which are associated with resting-state brain networks (RSNs including the default-mode network (DMN and frontoparietal network (FPN. Previous studies based on spiking-neuron network models and their reduced models, as well as those based on imaging data, suggest that resting-state network activity can be captured as attractor dynamics, i.e., dynamics of the brain state toward an attractive state and transitions between different attractors. Here, we analyze the energy landscapes of the RSNs by applying the maximum entropy model, or equivalently the Ising spin model, to human RSN data. We use the previously estimated parameter values to define the energy landscape, and the disconnectivity graph method to estimate the number of local energy minima (equivalent to attractors in attractor dynamics, the basin size, and hierarchical relationships among the different local minima. In both of the DMN and FPN, low-energy local minima tended to have large basins. A majority of the network states belonged to a basin of one of a few local minima. Therefore, a small number of local minima constituted the backbone of each RSN. In the DMN, the energy landscape consisted of two groups of low-energy local minima that are separated by a relatively high energy barrier. Within each group, the activity patterns of the local minima were similar, and different minima were connected by relatively low energy barriers. In the FPN, all dominant energy were separated by relatively low energy barriers such that they formed a single coarse-grained global minimum. Our results indicate that multistable attractor dynamics may underlie the DMN, but not the FPN, and assist memory maintenance with different memory states.

Spectral energy distributions of T Tauri stars - disk flaring and limits on accretion

International Nuclear Information System (INIS)

Kenyon, S.J.; Hartmann, L.

1987-01-01

The Adams et al. (1987) conclusion that much of the IR excess emission in the spectral energy distribution of T Tauri stars arises from reprocessing of stellar radiation by a dusty circumstellar disk is presently supported by analyses conducted in light of various models of these stars' spectra. A low mass reprocessing disk can, however, produce these spectra as well as a massive accretion disk. The detection of possible boundary layer radiation in the optical and near-UV regions poses the strongest limits on accretion rates. Disk accretion in the T Tauri phase does not significantly modify stellar evolution. 85 references

Genetic Algorithms: A New Method for Neutron Beam Spectral Characterization

International Nuclear Information System (INIS)

David W. Freeman

2000-01-01

A revolutionary new concept for solving the neutron spectrum unfolding problem using genetic algorithms (GAs) has recently been introduced. GAs are part of a new field of evolutionary solution techniques that mimic living systems with computer-simulated chromosome solutions that mate, mutate, and evolve to create improved solutions. The original motivation for the research was to improve spectral characterization of neutron beams associated with boron neutron capture therapy (BNCT). The GA unfolding technique has been successfully applied to problems with moderate energy resolution (up to 47 energy groups). Initial research indicates that the GA unfolding technique may well be superior to popular unfolding methods in common use. Research now under way at Kansas State University is focused on optimizing the unfolding algorithm and expanding its energy resolution to unfold detailed beam spectra based on multiple foil measurements. Indications are that the final code will significantly outperform current, state-of-the-art codes in use by the scientific community

Selection effects on GRB spectral-energy correlations

International Nuclear Information System (INIS)

Nava, Lara; Ghirlanda, Giancarlo; Ghisellini, Gabriele

2009-01-01

Instrumental selection effects can act upon the estimates of the peak energy E peak obs , the fluence F and the peak flux P of GRBs. If this were the case, then the correlations involving the corresponding rest frame quantities (i.e. E peak , E obs and the peak luminosity L iso ) would be questioned. We estimated, as a function of E peak obs , the minimum peak flux necessary to trigger a GRB and the minimum fluence a burst must have to determine the value of E peak obs by considering different instruments (BATSE, Swift, BeppoSAX). We find that the latter dominates over the former. We then study the E peak obs -fluence (and flux) correlation in the observer plane. GRBs with redshift show well defined E peak obs -F and E peak obs -P correlations: in this planes the selection effects are present, but do not determine the found correlations. This is not true for Swift GRBs with redshift, for which the spectral analysis threshold does affect their distribution in the observer planes. Extending the sample to GRBs without z, we still find a significant E peak obs -F correlation, although with a larger scatter than that defined by GRBs with redshift. We find that 6% are outliers of the Amati correlation. The E peak obs -P correlation of GRBs with or without redshift is the same and no outlier is found among bursts without redshift.

State energy data report 1992: Consumption estimates

Energy Technology Data Exchange (ETDEWEB)

1994-05-01

This is a report of energy consumption by state for the years 1960 to 1992. The report contains summaries of energy consumption for the US and by state, consumption by source, comparisons to other energy use reports, consumption by energy use sector, and describes the estimation methodologies used in the preparation of the report. Some years are not listed specifically although they are included in the summary of data.

A spectral chart method for estimating the mean turbulent kinetic energy dissipation rate

Science.gov (United States)

Djenidi, L.; Antonia, R. A.

2012-10-01

We present an empirical but simple and practical spectral chart method for determining the mean turbulent kinetic energy dissipation rate DNS spectra, points to this scaling being also valid at small Reynolds numbers, provided effects due to inhomogeneities in the flow are negligible. The methods avoid the difficulty associated with estimating time or spatial derivatives of the velocity fluctuations. It also avoids using the second hypothesis of K41, which implies the existence of a -5/3 inertial subrange only when the Taylor microscale Reynods number R λ is sufficiently large. The method is in fact applied to the lower wavenumber end of the dissipative range thus avoiding most of the problems due to inadequate spatial resolution of the velocity sensors and noise associated with the higher wavenumber end of this range.The use of spectral data (30 ≤ R λ ≤ 400) in both passive and active grid turbulence, a turbulent mixing layer and the turbulent wake of a circular cylinder indicates that the method is robust and should lead to reliable estimates of < \\varepsilon rangle in flows or flow regions where the first similarity hypothesis should hold; this would exclude, for example, the region near a wall.

Atmospheric parameters, spectral indexes and their relation to CPV spectral performance

Energy Technology Data Exchange (ETDEWEB)

Núñez, Rubén, E-mail: ruben.nunez@ies-def.upm.es; Antón, Ignacio, E-mail: ruben.nunez@ies-def.upm.es; Askins, Steve, E-mail: ruben.nunez@ies-def.upm.es; Sala, Gabriel, E-mail: ruben.nunez@ies-def.upm.es [Instituto de Energía Solar - Universidad Politécnica de Madrid, Instituto de Energía Solar, ETSI Telecomunicación, Ciudad Universitaria 28040 Madrid (Spain)

2014-09-26

Air Mass and atmosphere components (basically aerosol (AOD) and precipitable water (PW)) define the absorption of the sunlight that arrive to Earth. Radiative models such as SMARTS or MODTRAN use these parameters to generate an equivalent spectrum. However, complex and expensive instruments (as AERONET network devices) are needed to obtain AOD and PW. On the other hand, the use of isotype cells is a convenient way to characterize spectrally a place for CPV considering that they provide the photocurrent of the different internal subcells individually. Crossing data from AERONET station and a Tri-band Spectroheliometer, a model that correlates Spectral Mismatch Ratios and atmospheric parameters is proposed. Considering the amount of stations of AERONET network, this model may be used to estimate the spectral influence on energy performance of CPV systems close to all the stations worldwide.

A polychromatic adaption of the Beer-Lambert model for spectral decomposition

Science.gov (United States)

Sellerer, Thorsten; Ehn, Sebastian; Mechlem, Korbinian; Pfeiffer, Franz; Herzen, Julia; Noël, Peter B.

2017-03-01

We present a semi-empirical forward-model for spectral photon-counting CT which is fully compatible with state-of-the-art maximum-likelihood estimators (MLE) for basis material line integrals. The model relies on a minimum calibration effort to make the method applicable in routine clinical set-ups with the need for periodic re-calibration. In this work we present an experimental verifcation of our proposed method. The proposed method uses an adapted Beer-Lambert model, describing the energy dependent attenuation of a polychromatic x-ray spectrum using additional exponential terms. In an experimental dual-energy photon-counting CT setup based on a CdTe detector, the model demonstrates an accurate prediction of the registered counts for an attenuated polychromatic spectrum. Thereby deviations between model and measurement data lie within the Poisson statistical limit of the performed acquisitions, providing an effectively unbiased forward-model. The experimental data also shows that the model is capable of handling possible spectral distortions introduced by the photon-counting detector and CdTe sensor. The simplicity and high accuracy of the proposed model provides a viable forward-model for MLE-based spectral decomposition methods without the need of costly and time-consuming characterization of the system response.

The Effect of Substrate Emissivity on the Spectral Emission of a Hot-Gas Overlayer

Science.gov (United States)

2015-12-30

The spectral radiosity , denoted by Js(0, λ, Ts, Tsurf) accounts for both the emitted spectral energy and the reflected spectral energy from the...spectral intensity emitted from the window is given by I(λ, Twin) = εwinI(λ, Twin)BB where εwin is the spectral emissivity. The spectral radiosity incident... radiosity , one determines that the window contributes 6.1% reflected radiation to the observed signal from the anode. Figure 9. Anode-Window Geometry

Relaxation of excited surface states of thin Ge-implanted silica films probed by OSEE spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Zatsepin, A.F., E-mail: a.f.zatsepin@urfu.ru [Ural Federal University, Mira Street 19, 620002 Ekaterinburg (Russian Federation); Buntov, E.A.; Mikhailovich, A.P.; Slesarev, A.I. [Ural Federal University, Mira Street 19, 620002 Ekaterinburg (Russian Federation); Schmidt, B. [Research Center Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, P.O. Box 510119, D-01314 Dresden (Germany); Czarnowski, A. von; Fitting, Hans-Joachim [Institute of Physics, University of Rostock, Universitätsplatz 3, D-18051 Rostock (Germany)

2016-01-15

As an example of thin silica films, 30 nm SiO{sub 2}–Si heterostructures implanted with Ge{sup +} ions (10{sup 16} cm{sup −2} fluence) and rapid thermally annealed (RTA) at 950 °C are studied by means of optically stimulated electron emission (OSEE) in the spectral region of optical transparency for bulk silica. Quartz glass samples were used as references. Experimental data revealed a strong dependence between electron emission spectral features and RTA annealing time. The spectral contributions of both surface band tail states and interband transitions were clearly distinguished. The application of emission Urbach rule as well as Kane and Pässler equations allowed to analyze the OSEE spectra at different optical excitation energy ranges and to retrieve the important microstructural and energy parameters. The observed correlations between parameter values of Urbach- and Kane-related models suggest the implantation-induced conversion of both the vibrational subsystem and energy band of surface and interface electronic states. - Highlights: • Peculiarities of electron emission from excited surface states of SiO{sub 2}:Ge structures are studied. • Spectral contributions of surface band tails and interband transitions are distinguished. • Urbach and Kane models allow to examine photo-thermal emission mechanism. • Surface energy gap and structural disorder parameters are determined.

Efficiency of free-energy calculations of spin lattices by spectral quantum algorithms

International Nuclear Information System (INIS)

Master, Cyrus P.; Yamaguchi, Fumiko; Yamamoto, Yoshihisa

2003-01-01

Ensemble quantum algorithms are well suited to calculate estimates of the energy spectra for spin-lattice systems. Based on the phase estimation algorithm, these algorithms efficiently estimate discrete Fourier coefficients of the density of states. Their efficiency in calculating the free energy per spin of general spin lattices to bounded error is examined. We find that the number of Fourier components required to bound the error in the free energy due to the broadening of the density of states scales polynomially with the number of spins in the lattice. However, the precision with which the Fourier components must be calculated is found to be an exponential function of the system size

SPECTRAL SMILE CORRECTION IN CRISM HYPERSPECTRAL IMAGES

Science.gov (United States)

Ceamanos, X.; Doute, S.

2009-12-01

sharpening for every Θi is determined thanks to a loop of sharpening procedures, which is assessed by the examination of an estimation of the smile energy (the MNF-smile eigenvalue). As a matter of fact, a higher sharpening is performed on Θi as long as the smile energy decreases. Experiments on CRISM data show remarkable results regarding the decrease of smile energy (up to 80%) and the spectral shape preservation. In fact, initial smile-affected spectra do no longer show shifting nor smoothing (see Fig. 2). Line-averaged spectra and band 155 of FRT5AE3_07 showing spectral smile effects Line-averaged spectra and band 155 of smile-corrected FRT5AE3_07

[State Recognition of Solid Fermentation Process Based on Near Infrared Spectroscopy with Adaboost and Spectral Regression Discriminant Analysis].

Science.gov (United States)

Yu, Shuang; Liu, Guo-hai; Xia, Rong-sheng; Jiang, Hui

2016-01-01

In order to achieve the rapid monitoring of process state of solid state fermentation (SSF), this study attempted to qualitative identification of process state of SSF of feed protein by use of Fourier transform near infrared (FT-NIR) spectroscopy analysis technique. Even more specifically, the FT-NIR spectroscopy combined with Adaboost-SRDA-NN integrated learning algorithm as an ideal analysis tool was used to accurately and rapidly monitor chemical and physical changes in SSF of feed protein without the need for chemical analysis. Firstly, the raw spectra of all the 140 fermentation samples obtained were collected by use of Fourier transform near infrared spectrometer (Antaris II), and the raw spectra obtained were preprocessed by use of standard normal variate transformation (SNV) spectral preprocessing algorithm. Thereafter, the characteristic information of the preprocessed spectra was extracted by use of spectral regression discriminant analysis (SRDA). Finally, nearest neighbors (NN) algorithm as a basic classifier was selected and building state recognition model to identify different fermentation samples in the validation set. Experimental results showed as follows: the SRDA-NN model revealed its superior performance by compared with other two different NN models, which were developed by use of the feature information form principal component analysis (PCA) and linear discriminant analysis (LDA), and the correct recognition rate of SRDA-NN model achieved 94.28% in the validation set. In this work, in order to further improve the recognition accuracy of the final model, Adaboost-SRDA-NN ensemble learning algorithm was proposed by integrated the Adaboost and SRDA-NN methods, and the presented algorithm was used to construct the online monitoring model of process state of SSF of feed protein. Experimental results showed as follows: the prediction performance of SRDA-NN model has been further enhanced by use of Adaboost lifting algorithm, and the correct

Planck early results. XV. Spectral energy distributions and radio continuum spectra of northern extragalactic radio sources

DEFF Research Database (Denmark)

Aatrokoski, J.; Lähteenmäki, A.; Lavonen, N.

2011-01-01

Spectral energy distributions (SEDs) and radio continuum spectra are presented for a northern sample of 104 extragalactic radio sources, based on the Planck Early Release Compact Source Catalogue (ERCSC) and simultaneous multifrequency data. The nine Planck frequencies, from 30 to 857 GHz......, are complemented by a set of simultaneous observations ranging from radio to gamma-rays. This is the first extensive frequency coverage in the radio and millimetre domains for an essentially complete sample of extragalactic radio sources, and it shows how the individual shocks, each in their own phase...... of development, shape the radio spectra as they move in the relativistic jet. The SEDs presented in this paper were fitted with second and third degree polynomials to estimate the frequencies of the synchrotron and inverse Compton (IC) peaks, and the spectral indices of low and high frequency radio data...

Contrast-enhanced spectral mammography with a photon-counting detector.

Science.gov (United States)

Fredenberg, Erik; Hemmendorff, Magnus; Cederström, Björn; Aslund, Magnus; Danielsson, Mats

2010-05-01

Spectral imaging is a method in medical x-ray imaging to extract information about the object constituents by the material-specific energy dependence of x-ray attenuation. The authors have investigated a photon-counting spectral imaging system with two energy bins for contrast-enhanced mammography. System optimization and the potential benefit compared to conventional non-energy-resolved absorption imaging was studied. A framework for system characterization was set up that included quantum and anatomical noise and a theoretical model of the system was benchmarked to phantom measurements. Optimal combination of the energy-resolved images corresponded approximately to minimization of the anatomical noise, which is commonly referred to as energy subtraction. In that case, an ideal-observer detectability index could be improved close to 50% compared to absorption imaging in the phantom study. Optimization with respect to the signal-to-quantum-noise ratio, commonly referred to as energy weighting, yielded only a minute improvement. In a simulation of a clinically more realistic case, spectral imaging was predicted to perform approximately 30% better than absorption imaging for an average glandularity breast with an average level of anatomical noise. For dense breast tissue and a high level of anatomical noise, however, a rise in detectability by a factor of 6 was predicted. Another approximately 70%-90% improvement was found to be within reach for an optimized system. Contrast-enhanced spectral mammography is feasible and beneficial with the current system, and there is room for additional improvements. Inclusion of anatomical noise is essential for optimizing spectral imaging systems.

Contrast-enhanced spectral mammography with a photon-counting detector

Energy Technology Data Exchange (ETDEWEB)

Fredenberg, Erik; Hemmendorff, Magnus; Cederstroem, Bjoern; Aaslund, Magnus; Danielsson, Mats [Department of Physics, Royal Institute of Technology, AlbaNova, SE-106 91 Stockholm (Sweden); Sectra Mamea AB, Smidesvaegen 5, SE-171 41 Solna (Sweden); Department of Physics, Royal Institute of Technology, AlbaNova, SE-106 91 Stockholm (Sweden); Sectra Mamea AB, Smidesvaegen 5, SE-171 41 Solna (Sweden); Department of Physics, Royal Institute of Technology, AlbaNova, SE-106 91 Stockholm (Sweden)

2010-05-15

Purpose: Spectral imaging is a method in medical x-ray imaging to extract information about the object constituents by the material-specific energy dependence of x-ray attenuation. The authors have investigated a photon-counting spectral imaging system with two energy bins for contrast-enhanced mammography. System optimization and the potential benefit compared to conventional non-energy-resolved absorption imaging was studied. Methods: A framework for system characterization was set up that included quantum and anatomical noise and a theoretical model of the system was benchmarked to phantom measurements. Results: Optimal combination of the energy-resolved images corresponded approximately to minimization of the anatomical noise, which is commonly referred to as energy subtraction. In that case, an ideal-observer detectability index could be improved close to 50% compared to absorption imaging in the phantom study. Optimization with respect to the signal-to-quantum-noise ratio, commonly referred to as energy weighting, yielded only a minute improvement. In a simulation of a clinically more realistic case, spectral imaging was predicted to perform approximately 30% better than absorption imaging for an average glandularity breast with an average level of anatomical noise. For dense breast tissue and a high level of anatomical noise, however, a rise in detectability by a factor of 6 was predicted. Another {approx}70%-90% improvement was found to be within reach for an optimized system. Conclusions: Contrast-enhanced spectral mammography is feasible and beneficial with the current system, and there is room for additional improvements. Inclusion of anatomical noise is essential for optimizing spectral imaging systems.

Tensor-based Dictionary Learning for Spectral CT Reconstruction

Science.gov (United States)

Zhang, Yanbo; Wang, Ge

2016-01-01

Spectral computed tomography (CT) produces an energy-discriminative attenuation map of an object, extending a conventional image volume with a spectral dimension. In spectral CT, an image can be sparsely represented in each of multiple energy channels, and are highly correlated among energy channels. According to this characteristics, we propose a tensor-based dictionary learning method for spectral CT reconstruction. In our method, tensor patches are extracted from an image tensor, which is reconstructed using the filtered backprojection (FBP), to form a training dataset. With the Candecomp/Parafac decomposition, a tensor-based dictionary is trained, in which each atom is a rank-one tensor. Then, the trained dictionary is used to sparsely represent image tensor patches during an iterative reconstruction process, and the alternating minimization scheme is adapted for optimization. The effectiveness of our proposed method is validated with both numerically simulated and real preclinical mouse datasets. The results demonstrate that the proposed tensor-based method generally produces superior image quality, and leads to more accurate material decomposition than the currently popular popular methods. PMID:27541628

Tensor-Based Dictionary Learning for Spectral CT Reconstruction.

Science.gov (United States)

Zhang, Yanbo; Mou, Xuanqin; Wang, Ge; Yu, Hengyong

2017-01-01

Spectral computed tomography (CT) produces an energy-discriminative attenuation map of an object, extending a conventional image volume with a spectral dimension. In spectral CT, an image can be sparsely represented in each of multiple energy channels, and are highly correlated among energy channels. According to this characteristics, we propose a tensor-based dictionary learning method for spectral CT reconstruction. In our method, tensor patches are extracted from an image tensor, which is reconstructed using the filtered backprojection (FBP), to form a training dataset. With the Candecomp/Parafac decomposition, a tensor-based dictionary is trained, in which each atom is a rank-one tensor. Then, the trained dictionary is used to sparsely represent image tensor patches during an iterative reconstruction process, and the alternating minimization scheme is adapted for optimization. The effectiveness of our proposed method is validated with both numerically simulated and real preclinical mouse datasets. The results demonstrate that the proposed tensor-based method generally produces superior image quality, and leads to more accurate material decomposition than the currently popular popular methods.

Differential diagnosis between benign and malignant pleural effusion with dual-energy spectral CT.

Science.gov (United States)

Zhang, Xirong; Duan, Haifeng; Yu, Yong; Ma, Chunling; Ren, Zhanli; Lei, Yuxin; He, Taiping; Zhang, Ming

2018-01-01

of 100% and specificity of 71.4% with area-under-curve of 0.933 for differentiating benign from malignant effusion. The CT value measurement at both high and low energy levels and the effective atomic number obtained in a single spectral CT scan can assist the differential diagnosis of benign from malignant pleural effusion.Combining them with patient age and disease history can further improve diagnostic performance. Clinical findings and Spectral CT imaging can provide significant evidences about the nature of pleural effusion.

Pairing-induced kinetic energy lowering in doped antiferromagnets

International Nuclear Information System (INIS)

Wrobel, P; Eder, R; Fulde, P

2003-01-01

We analyse lowering of the kinetic energy in doped antiferromagnets at the transition to the superconducting state. Measurements of optical conductivity indicate that such unconventional behaviour takes place in underdoped Bi-2212. We argue that the definition of the operator representing the kinetic energy is determined by experimental conditions. The thermodynamic average of that operator is related to the integrated spectral weight of the optical conductivity and thus depends on the cut-off frequency limiting that integral. If the upper limit of the integral lies below the charge transfer gap the spectral weight represents the average of the hopping term in the space restricted to the energy range below the gap. We show that the kinetic energy is indeed lowered at the superconducting transition in the t-J model (tJM), which is an effective model defined in the restricted space. That result is in agreement with experimental observations and may be attributed to the formation of spin polarons and the change of roles which are played by the kinetic and the potential energy in the tJM and in some effective model for spin polarons. The total spectral weight represents the kinetic energy in a model defined in a broader space if the upper limit in the integral of the optical conductivity is set above the gap. We demonstrate that the kinetic energy in the Hubbard model is also lowered in the superconducting state. That result does not agree with experimental observations, indicating that the spectral weight is conserved for all temperatures if the upper limit of the integral is set above the charge transfer gap. This discrepancy suggests that a single band model is not capable of describing in some respects the physics of excitations across the gap

Solar energy in the United States

International Nuclear Information System (INIS)

Ochoa, D.; Slaoui, A.; Soler, R.; Bermudez, V.

2009-01-01

Written by a group of five French experts who visited several research centres, innovating companies and solar power stations in the United States, this report first proposes an overview of solar energy in the United States, indicating and commenting the respective shares of different renewable energies in the production, focusing on the photovoltaic energy production and its RD sector. The second part presents industrial and research activities in the solar sector, and more specifically photovoltaic technologies (silicon and thin layer technology) and solar concentrators (thermal solar concentrators, photovoltaic concentrators). The last chapter presents the academic research activities in different universities (California Tech Beckman Institute, Stanford, National Renewable Energy Laboratory, Colorado School of Mines)

The color of X-rays Spectral X-ray computed tomography using energy sensitive pixel detectors

CERN Document Server

Schioppa, Enrico Junior

Energy sensitive X-ray imaging detectors are produced by connecting a semiconductor sensor to a spectroscopic pixel readout chip. In this thesis, the applicability of such detectors to X-ray Computed Tomography (CT) is studied. A prototype Medipix based silicon detector is calibrated using X-ray fluorescence. The charge transport properties of the sensor are characterized using a high energy beam of charged particles at the Super Proton Synchrotron (SPS) at the European Center for Nuclear Research (CERN). Monochromatic X-rays at the European Synchrotron Radiation Facility (ESRF) are used to determined the energy response function. These data are used to implement a physics-based CT projection operator that accounts for the transmission of the source spectrum through the sample and detector effects. Based on this projection operator, an iterative spectral CT reconstruction algorithm is developed by extending an Ordered Subset Expectation Maximization (OSEM) method. Subsequently, a maximum likelihood based algo...

Element-specific spectral imaging of multiple contrast agents: a phantom study

Science.gov (United States)

Panta, R. K.; Bell, S. T.; Healy, J. L.; Aamir, R.; Bateman, C. J.; Moghiseh, M.; Butler, A. P. H.; Anderson, N. G.

2018-02-01

This work demonstrates the feasibility of simultaneous discrimination of multiple contrast agents based on their element-specific and energy-dependent X-ray attenuation properties using a pre-clinical photon-counting spectral CT. We used a photon-counting based pre-clinical spectral CT scanner with four energy thresholds to measure the X-ray attenuation properties of various concentrations of iodine (9, 18 and 36 mg/ml), gadolinium (2, 4 and 8 mg/ml) and gold (2, 4 and 8 mg/ml) based contrast agents, calcium chloride (140 and 280 mg/ml) and water. We evaluated the spectral imaging performances of different energy threshold schemes between 25 to 82 keV at 118 kVp, based on K-factor and signal-to-noise ratio and ranked them. K-factor was defined as the X-ray attenuation in the K-edge containing energy range divided by the X-ray attenuation in the preceding energy range, expressed as a percentage. We evaluated the effectiveness of the optimised energy selection to discriminate all three contrast agents in a phantom of 33 mm diameter. A photon-counting spectral CT using four energy thresholds of 27, 33, 49 and 81 keV at 118 kVp simultaneously discriminated three contrast agents based on iodine, gadolinium and gold at various concentrations using their K-edge and energy-dependent X-ray attenuation features in a single scan. A ranking method to evaluate spectral imaging performance enabled energy thresholds to be optimised to discriminate iodine, gadolinium and gold contrast agents in a single spectral CT scan. Simultaneous discrimination of multiple contrast agents in a single scan is likely to open up new possibilities of improving the accuracy of disease diagnosis by simultaneously imaging multiple bio-markers each labelled with a nano-contrast agent.

Processing of spectral X-ray data with principal components analysis

CERN Document Server

Butler, A P H; Cook, N J; Butzer, J; Schleich, N; Tlustos, L; Scott, N; Grasset, R; de Ruiter, N; Anderson, N G

2011-01-01

The goal of the work was to develop a general method for processing spectral x-ray image data. Principle component analysis (PCA) is a well understood technique for multivariate data analysis and so was investigated. To assess this method, spectral (multi-energy) computed tomography (CT) data was obtained using a Medipix2 detector in a MARS-CT (Medipix All Resolution System). PCA was able to separate bone (calcium) from two elements with k-edges in the X-ray spectrum used (iodine and barium) within a mouse. This has potential clinical application in dual-energy CT systems and future Medipix3 based spectral imaging where up to eight energies can be recorded simultaneously with excellent energy resolution. (c) 2010 Elsevier B.V. All rights reserved.

On Pythagoras Theorem for Products of Spectral Triples

Science.gov (United States)

D'Andrea, Francesco; Martinetti, Pierre

2013-05-01

We discuss a version of Pythagoras theorem in noncommutative geometry. Usual Pythagoras theorem can be formulated in terms of Connes' distance, between pure states, in the product of commutative spectral triples. We investigate the generalization to both non-pure states and arbitrary spectral triples. We show that Pythagoras theorem is replaced by some Pythagoras inequalities, that we prove for the product of arbitrary (i.e. non-necessarily commutative) spectral triples, assuming only some unitality condition. We show that these inequalities are optimal, and we provide non-unital counter-examples inspired by K-homology.

In-plane optical spectral weight redistribution in the optimally doped Ba0.6 K0.4Fe2As2 superconductor

International Nuclear Information System (INIS)

Xu Bing; Dai Yao-Min; Xiao Hong; Qiu Xiang-Gang; Lobo, R. P. S. M.

2014-01-01

We performed detailed temperature-dependent optical measurements on optimally doped Ba 0.6 K 0.4 Fe 2 As 2 single crystal. We examine the changes of the in-plane optical conductivity spectral weight in the normal state and the evolution of the superconducting condensate in the superconducting state. In the normal state, the low-frequency spectral weight shows a metallic response with an arctan (T) dependence, indicating a T-linear scattering rate behavior for the carriers. A high energy spectral weight transfer associated with the Hund's coupling occurs from the low frequencies below 4000 cm −1 ∼ 5000 cm −1 to higher frequencies up to at least 10 cm −1 . Its temperature dependence analysis suggests that the Hund's coupling strength is continuously enhanced as the temperature is reduced. In the superconducting state, the FGT sum rule is conserved according to the spectral weight estimation within the conduction bands, only about 40% of the conduction bands participates in the superconducting condensate indicating that Ba 0.6 K 0.4 Fe 2 As 2 is in dirty limit. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

High-temperature partition functions, specific heats and spectral radiative properties of diatomic molecules with an improved calculation of energy levels

Science.gov (United States)

Qin, Z.; Zhao, J. M.; Liu, L. H.

2018-05-01

The level energies of diatomic molecules calculated by the frequently used Dunham expansion will become less accurate for high-lying vibrational and rotational levels. In this paper, the potential curves for the lower-lying electronic states with accurate spectroscopic constants are reconstructed using the Rydberg-Klein-Rees (RKR) method, which are extrapolated to the dissociation limits by fitting of the theoretical potentials, and the rest of the potential curves are obtained from the ab-initio results in the literature. Solving the rotational dependence of the radial Schrödinger equation over the obtained potential curves, we determine the rovibrational level energies, which are then used to calculate the equilibrium and non-equilibrium thermodynamic properties of N2, N2+, NO, O2, CN, C2, CO and CO+. The partition functions and the specific heats are systematically validated by available data in the literature. Finally, we calculate the radiative source strengths of diatomic molecules in thermodynamic equilibrium, which agree well with the available values in the literature. The spectral radiative intensities for some diatomic molecules in thermodynamic non-equilibrium are calculated and validated by available experimental data.

Renewable energies in the EU-Accession States

International Nuclear Information System (INIS)

Reiche, Danyel

2006-01-01

The aim of this article is to discuss obstacles and success conditions for renewable energy sources in the EU-Accession States and to compare them with the framework in the EU-15. Besides the ten states which will join the EU in 2004, Bulgaria and Romania which will probably join in 2007 as well as Turkey are analysed. Most of these countries have had a century-long tradition in the utilisation of RES, primarily in biomass and hydropower. However, the communist regimes were convinced of the superiority of large-scale systems and converted the energy sectors into centralised units. Due to this dominating belief system more decentralised applications such as installations using renewable energies had to close. One crucial driving force for future renewable energy development in the Accession States comes from the stipulations set by the EU. The EU-Directive on the promotion of electricity produced from RES gives the new EU-members targets for their RES-development until 2010. Due to the Directive many Accession States have already begun to pay more attention to the topic and to introduce more systematic policies. Six of the Accession States have introduced minimum tariffs which were one of the main success conditions (besides a stable and sound investment programme as well as favourable background conditions) in the leading wind energy countries Germany and Spain. Beside the external pressure by the EU and other international obligations other driving forces such as the path dependencies in the national energy policies (degree of coal, oil and gas exploitation, nuclear power use, import dependency), the political support schemes for renewable energies, possibilities of obtaining external financial support and the cognitive environment are discussed. Finally similarities and differences between EU-15 and Accession States are worked out

Staircase functions, spectral regidity and a rule for quantizing chaos

International Nuclear Information System (INIS)

Aurich, R.; Steiner, F.

1991-07-01

Considering the Selberg trace formula as an exact version of Gutzwiller's semiclassical periodic-orbit theory in the case of the free motion on compact Riemann surfaces with constant negative curvature (Hadamard-Gutzwiller model), we study two complementary basic problems in quantum chaology: the computation of the calssical staircase N(l), the number of periodic orbits with length shorter than l, in terms of the quantal energy spectrum {E n }, the computation of the spectral staircase N (E), the number of quantal energies below the energy E, in terms of the length spectrum {l n } of the classical periodic orbits. A formulation of the periodic-orbit theory is presented which is intrinsically unsmoothed, but for which an effective smoothing arises from the limited 'input data', i.e. from the limited knowledge of the periodic orbits in the case of N(E) and the limited knowledge of quantal energies in the case of N(l). Based on the periodic-orbit formula for N(E), we propose a new rule for quantizing chaos, which simply states that the quantal energies are determined by the zeros of the function ξ 1 (E) = cos (πN(E)). The formulas for N(l) and N(E) as well as the new quantization condition are tested numerically. Furthermore, it is shown that the staircase N(E) computed from the length spectrum yields (up to a constant) a good description of the spectral rigidity Δ 3 (L), being the first numerical attempt to compute a statistical property of the quantal energy spectrum of a chaotic system from classical periodic orbits. (orig.)

Characterization of the titanium Kβ spectral profile

International Nuclear Information System (INIS)

Chantler, C T; Smale, L F; Kinnane, M N; Illig, A J; Kimpton, J A; Crosby, D N

2013-01-01

Transition metals have Kα and Kβ characteristic radiation possessing complex asymmetric spectral profiles. Instrumental broadening normally encountered in x-ray experiments shifts features of profiles used for calibration, such as peak energy, by many times the quoted accuracies. We measure and characterize the titanium Kβ spectral profile. The peak energy of the titanium Kβ spectral profile is found to be 4931.966 ± 0.022 eV prior to instrumental broadening. This 4.5 ppm result decreases the uncertainty over the past literature by a factor of 2.6 and is 2.4 standard deviations from the previous standard. The spectrum is analysed and the resolution-free lineshape is extracted and listed for use in other experiments. We also incorporate improvement in analysis applied to earlier results for V Kβ. (paper)

Neutron spectrum perturbations due to scattering materials and their effect on the average neutron energy, the spectral index, and the hardness parameter

International Nuclear Information System (INIS)

Wright, H.L.; Meason, J.L.; Wolf, M.; Harvey, J.T.

1976-01-01

Measurements have been performed on the perturbing effect of a number of scattering materials by the 'free-field' neutron leakage spectrum from a Godiva Type Critical Assembly (White Sands Missile Range Fast Burst Reactor). The results of these measurements are interpreted in relation to some of the general parameters characterizing a neutron environment, namely, the average neutron energy >10 KeV, the spectral index and the hardness parameter. Three neutron spectrum measurements have been performed, each under different experimental configurations of scattering materials. Results from these measurements show the following with relation to the spectral index: (1) The neutron environment on the core surface and at 12-inches from the core surface (free-field) yield a spectral index of 6.8, (2) The neutron environment behind a 4.75-inch Plexiglas plate yield 4.6 for the spectral index and (3) The neutron environment behind a 2-inch aluminum plate yield 6.7 for the spectral index. It is concluded that the core surface and the 12-inch from core surface neutron environment are identical with the 'free-field' neutron environment at 20-inches when considering only those neutrons with energy >10 KeV. On the other hand, it appears that the 4.75 inches of Plexiglas severely perturbs the 'free-field' neutron environment, i.e., a much harder neutron spectrum >10 KeV. In the situation where 2-inches of aluminum is used as the perturbing medium, essentially no change in the neutron spectrum >10 KeV is noted

Constructing the spectral web of rotating plasmas

Science.gov (United States)

Goedbloed, Hans

2012-10-01

Rotating plasmas are ubiquitous in nature. The theory of MHD stability of such plasmas, initiated a long time ago, has severely suffered from the wide spread misunderstanding that it necessarily involves non-self-adjoint operators. It has been shown (J.P. Goedbloed, PPCF 16, 074001, 2011; Goedbloed, Keppens and Poedts, Advanced Magnetohydrodynamics, Cambridge, 2010) that, on the contrary, spectral theory of moving plasmas can be constructed entirely on the basis of energy conservation and self-adjointness of the occurring operators. The spectral web is a further development along this line. It involves the construction of a network of curves in the complex omega-plane associated with the complex complementary energy, which is the energy needed to maintain harmonic time dependence in an open system. Vanishing of that energy, at the intersections of the mentioned curves, yields the eigenvalues of the closed system. This permits to consider the enormous diversity of MHD instabilities of rotating tokamaks, accretion disks about compact objects, and jets emitted from those objects, from a single view point. This will be illustrated with results obtained with a new spectral code (ROC).

Emerging Energy Alternatives for the Southeastern States

Science.gov (United States)

Stefanakos, E. K. (Editor)

1978-01-01

The proceedings of the first symposium on emerging energy alternatives for the Southeastern States are presented. Some topics discussed are: (1) solar energy, (2) wood energy, (3) novel energy sources, (4) agricultural and industrial process heat, (5) waste utilization, (6) energy conservation and (7) ocean thermal energy conversion.

Role of State Policy in Renewable Energy Development

Energy Technology Data Exchange (ETDEWEB)

Doris, E.; Busche, S.; Hockett, S.; McLaren, J.

2009-07-01

State policies can support renewable energy development by driving markets, providing certainty in the investment market, and incorporating the external benefits of the technologies into cost/benefit calculations. Using statistical analyses and policy design best practices, this paper quantifies the impact of state-level policies on renewable energy development in order to better understand the role of policy on development and inform policy makers on the policy mechanisms that provide maximum benefit. The results include the identification of connections between state policies and renewable energy development, as well as a discussion placing state policy efforts in context with other factors that influence the development of renewable energy (e.g. federal policy, resource availability, technology cost, public acceptance).

State of the States 2009. Renewable Energy Development and the Role of Policy

Energy Technology Data Exchange (ETDEWEB)

Doris, Elizabeth [National Renewable Energy Lab. (NREL), Golden, CO (United States); McLaren, Joyce [National Renewable Energy Lab. (NREL), Golden, CO (United States); Healey, Victoria [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hockett, Stephen [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2009-10-01

This report tracks the progress of U.S. renewable energy development at the state level, with metrics on development status and reviews of relevant policies. The analysis offers state-by-state policy suggestions and develops performance-based evaluation metrics to accelerate and improve renewable energy development.

Identification of Raman peaks of high-Tc cuprates in normal state through density of states

International Nuclear Information System (INIS)

Bishoyi, K.C.; Rout, G.C.; Behera, S.N.

2007-01-01

We present a microscopic theory to explain and identify the Raman spectral peaks of high-T c cuprates R 2-x M x CuO 4 in the normal state. We used electronic Hamiltonian prescribed by Fulde in presence of anti-ferromagnetism. Phonon interaction to the hybridization between the conduction electrons of the system and the f-electrons has been incorporated in the calculation. The phonon spectral density is calculated by the Green's function technique of Zubarev at zero wave vector and finite (room) temperature limit. The four Raman active peaks (P 1 -P 4 ) representing the electronic states of the atomic sub-systems of the cuprate system are identified by the calculated quasi-particle energy bands and electron density of states (DOS). The effect of interactions on these peaks are also explained

A gamma-ray burst with a high-energy spectral component inconsistent with the synchrotron shock model.

Science.gov (United States)

González, M M; Dingus, B L; Kaneko, Y; Preece, R D; Dermer, C D; Briggs, M S

2003-08-14

Gamma-ray bursts are among the most powerful events in nature. These events release most of their energy as photons with energies in the range from 30 keV to a few MeV, with a smaller fraction of the energy radiated in radio, optical, and soft X-ray afterglows. The data are in general agreement with a relativistic shock model, where the prompt and afterglow emissions correspond to synchrotron radiation from shock-accelerated electrons. Here we report an observation of a high-energy (multi-MeV) spectral component in the burst of 17 October 1994 that is distinct from the previously observed lower-energy gamma-ray component. The flux of the high-energy component decays more slowly and its fluence is greater than the lower-energy component; it is described by a power law of differential photon number index approximately -1 up to about 200 MeV. This observation is difficult to explain with the standard synchrotron shock model, suggesting the presence of new phenomena such as a different non-thermal electron process, or the interaction of relativistic protons with photons at the source.

Communication: Broad manifold of excitonic states in light-harvesting complex 1 promotes efficient unidirectional energy transfer in vivo

Science.gov (United States)

Sohail, Sara H.; Dahlberg, Peter D.; Allodi, Marco A.; Massey, Sara C.; Ting, Po-Chieh; Martin, Elizabeth C.; Hunter, C. Neil; Engel, Gregory S.

2017-10-01

In photosynthetic organisms, the pigment-protein complexes that comprise the light-harvesting antenna exhibit complex electronic structures and ultrafast dynamics due to the coupling among the chromophores. Here, we present absorptive two-dimensional (2D) electronic spectra from living cultures of the purple bacterium, Rhodobacter sphaeroides, acquired using gradient assisted photon echo spectroscopy. Diagonal slices through the 2D lineshape of the LH1 stimulated emission/ground state bleach feature reveal a resolvable higher energy population within the B875 manifold. The waiting time evolution of diagonal, horizontal, and vertical slices through the 2D lineshape shows a sub-100 fs intra-complex relaxation as this higher energy population red shifts. The absorption (855 nm) of this higher lying sub-population of B875 before it has red shifted optimizes spectral overlap between the LH1 B875 band and the B850 band of LH2. Access to an energetically broad distribution of excitonic states within B875 offers a mechanism for efficient energy transfer from LH2 to LH1 during photosynthesis while limiting back transfer. Two-dimensional lineshapes reveal a rapid decay in the ground-state bleach/stimulated emission of B875. This signal, identified as a decrease in the dipole strength of a strong transition in LH1 on the red side of the B875 band, is assigned to the rapid localization of an initially delocalized exciton state, a dephasing process that frustrates back transfer from LH1 to LH2.

Virtual Non-Contrast CT Using Dual-Energy Spectral CT: Feasibility of Coronary Artery Calcium Scoring.

Science.gov (United States)

Song, Inyoung; Yi, Jeong Geun; Park, Jeong Hee; Kim, Sung Mok; Lee, Kyung Soo; Chung, Myung Jin

2016-01-01

To evaluate the feasibility of coronary artery calcium scoring based on three virtual noncontrast-enhanced (VNC) images derived from single-source spectral dual-energy CT (DECT) as compared with true noncontrast-enhanced (TNC) images. This prospective study was conducted with the approval of our Institutional Review Board. Ninety-seven patients underwent noncontrast CT followed by contrast-enhanced chest CT using single-source spectral DECT. Iodine eliminated VNC images were reconstructed using two kinds of 2-material decomposition algorithms (material density iodine-water pair [MDW], material density iodine-calcium pair [MDC]) and a material suppressed algorithm (material suppressed iodine [MSI]). Two readers independently quantified calcium on VNC and TNC images. The Spearman correlation coefficient test and Bland-Altman method were used for statistical analyses. Coronary artery calcium scores from all three VNC images showed excellent correlation with those from the TNC images (Spearman's correlation coefficient [ρ] = 0.94, 0.88, and 0.89 for MDW, MDC, and MSI, respectively; p VNC images also correlated well with those from TNC images (ρ = 0.92, 0.87, and 0.91 for MDW, MDC, and MSI, respectively; p VNC images, coronary calcium from MDW correlated best with that from TNC. The coronary artery calcium scores and volumes were significantly lower from the VNC images than from the TNC images (p VNC images from contrast-enhanced CT using dual-energy material decomposition/suppression is feasible for coronary calcium scoring. The absolute value from VNC tends to be smaller than that from TNC.

Effective dark energy equation of state in interacting dark energy models

International Nuclear Information System (INIS)

Avelino, P.P.; Silva, H.M.R. da

2012-01-01

In models where dark matter and dark energy interact non-minimally, the total amount of matter in a fixed comoving volume may vary from the time of recombination to the present time due to energy transfer between the two components. This implies that, in interacting dark energy models, the fractional matter density estimated using the cosmic microwave background assuming no interaction between dark matter and dark energy will in general be shifted with respect to its true value. This may result in an incorrect determination of the equation of state of dark energy if the interaction between dark matter and dark energy is not properly accounted for, even if the evolution of the Hubble parameter as a function of redshift is known with arbitrary precision. In this Letter we find an exact expression, as well as a simple analytical approximation, for the evolution of the effective equation of state of dark energy, assuming that the energy transfer rate between dark matter and dark energy is described by a simple two-parameter model. We also provide analytical examples where non-phantom interacting dark energy models mimic the background evolution and primary cosmic microwave background anisotropies of phantom dark energy models.

Effective dark energy equation of state in interacting dark energy models

Energy Technology Data Exchange (ETDEWEB)

Avelino, P.P., E-mail: ppavelin@fc.up.pt [Centro de Astrofisica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Departamento de Fisica e Astronomia da Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Silva, H.M.R. da, E-mail: hilberto.silva@gmail.com [Departamento de Fisica e Astronomia da Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal)

2012-07-24

In models where dark matter and dark energy interact non-minimally, the total amount of matter in a fixed comoving volume may vary from the time of recombination to the present time due to energy transfer between the two components. This implies that, in interacting dark energy models, the fractional matter density estimated using the cosmic microwave background assuming no interaction between dark matter and dark energy will in general be shifted with respect to its true value. This may result in an incorrect determination of the equation of state of dark energy if the interaction between dark matter and dark energy is not properly accounted for, even if the evolution of the Hubble parameter as a function of redshift is known with arbitrary precision. In this Letter we find an exact expression, as well as a simple analytical approximation, for the evolution of the effective equation of state of dark energy, assuming that the energy transfer rate between dark matter and dark energy is described by a simple two-parameter model. We also provide analytical examples where non-phantom interacting dark energy models mimic the background evolution and primary cosmic microwave background anisotropies of phantom dark energy models.

Assistance to States on Policies Related to Wind Energy Issues

Energy Technology Data Exchange (ETDEWEB)

Brown, Matthew, H; Decesaro, Jennifer; DOE Project Officer - Keith Bennett

2005-07-15

This final report summarizes work carried out under agreement with the US Department of Energy, related to wind energy policy issues. This project has involved a combination of outreach and publications on wind energy, with a specific focus on educating state-level policymakers. Education of state policymakers is vitally important because state policy (in the form of incentives or regulation) is a crucial part of the success of wind energy. State policymakers wield a significant influence over all of these policies. They are also in need of high quality, non-biased educational resources which this project provided. This project provided outreach to legislatures, in the form of meetings designed specifically for state legislators and legislative staff, responses to information requests on wind energy, and publications. The publications addressed: renewable energy portfolio standards, wind energy transmission, wind energy siting, case studies of wind energy policy, avian issues, economic development, and other related issues. These publications were distributed to legislative energy committee members, and chairs, legislative staff, legislative libraries, and other related state officials. The effect of this effort has been to provide an extensive resource of information about wind information for state policymakers in a form that is useful to them. This non-partisan information has been used as state policymakers attempt to develop their own policy proposals related to wind energy in the states.

The United States and world energy markets

International Nuclear Information System (INIS)

Ramsay, W.C.

1992-01-01

The United States, dominating the world's energy markets as a producer and consumer, is sensitive to changes in this market and intends to influence the development of global energy policy. Supply will be increased by nations such as Venezuela, Indonesia and perhaps in the future a United Yemen and the Commonwealth of Independent States, moving to freer market economies which will allow investment opportunities previously inaccessible to foreign companies. Although world energy demand will grow, little of this will be in the US where, under the National Energy Strategy, comprehensive measures are being introduced to improve energy efficiency. The US energy security will be further improved by such measures as diversification of supply, larger domestic production and increasing interdependence between suppliers, traders and consumers. (author)

Quantum spectral curve for arbitrary state/operator in AdS{sub 5}/CFT{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Gromov, Nikolay [Mathematics Department, King’s College London,The Strand, London WC2R 2LS (United Kingdom); St.Petersburg INP,Gatchina, 188 300, St.Petersburg (Russian Federation); Kazakov, Vladimir [LPT, École Normale Superieure,24, rue Lhomond 75005 Paris (France); Université Paris-VI,Place Jussieu, 75005 Paris (France); School of Natural Sciences, Institute for Advanced Study,Princeton, NJ08540 (United States); Leurent, Sébastien [Institut de Mathématiques de Bourgogne, UMR 5584 du CNRS,Université de Bourgogne, 9 avenue Alain Savary, 21000 DIJON (France); Volin, Dmytro [Nordita KTH Royal Institute of Technology and Stockholm University,Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden); School of Mathematics, Trinity College Dublin,College Green, Dublin 2 (Ireland)

2015-09-28

We give a derivation of quantum spectral curve (QSC) — a finite set of Riemann-Hilbert equations for exact spectrum of planar N=4 SYM theory proposed in our recent paper Phys. Rev. Lett. 112 (2014). We also generalize this construction to all local single trace operators of the theory, in contrast to the TBA-like approaches worked out only for a limited class of states. We reveal a rich algebraic and analytic structure of the QSC in terms of a so called Q-system — a finite set of Baxter-like Q-functions. This new point of view on the finite size spectral problem is shown to be completely compatible, though in a far from trivial way, with already known exact equations (analytic Y-system/TBA, or FiNLIE). We use the knowledge of this underlying Q-system to demonstrate how the classical finite gap solutions and the asymptotic Bethe ansatz emerge from our formalism in appropriate limits.

Toward accurate prediction of potential energy surfaces and the spectral density of hydrogen bonded systems

International Nuclear Information System (INIS)

Rekik, Najeh

2014-01-01

Despite the considerable progress made in quantum theory and computational methods, detailed descriptions of the potential energy surfaces of hydrogen-bonded systems have not yet been achieved. In addition, the hydrogen bond (H-bond) itself is still so poorly understood at the fundamental level that it remains unclear exactly what geometry constitutes a “real” H-bond. Therefore, in order to investigate features essential for hydrogen bonded complexes, a simple, efficient, and general method for calculating matrix elements of vibrational operators capable of describing the stretching modes and the H-bond bridges of hydrogen-bonded systems is proposed. The derived matrix elements are simple and computationally easy to evaluate, which makes the method suitable for vibrational studies of multiple-well potentials. The method is illustrated by obtaining potential energy surfaces for a number of two-dimensional systems with repulsive potentials chosen to be in Gaussian form for the stretching mode and of the Morse-type for the H-bond bridge dynamics. The forms of potential energy surfaces of weak and strong hydrogen bonds are analyzed by varying the asymmetry of the Gaussian potential. Moreover, the choice and applicability of the selected potential for the stretching mode and comparison with other potentials used in the area of hydrogen bond research are discussed. The approach for the determination of spectral density has been constructed in the framework of the linear response theory for which spectral density is obtained by Fourier transform of the autocorrelation function of the dipole moment operator of the fast mode. The approach involves anharmonic coupling between the high frequency stretching vibration (double well potential) and low-frequency donor-acceptor stretching mode (Morse potential) as well as the electrical anharmonicity of the dipole moment operator of the fast mode. A direct relaxation mechanism is incorporated through a time decaying exponential

Energy Efficiency - Spectral Efficiency Trade-off: A Multiobjective Optimization Approach

KAUST Repository

Amin, Osama

2015-04-23

In this paper, we consider the resource allocation problem for energy efficiency (EE) - spectral efficiency (SE) trade-off. Unlike traditional research that uses the EE as an objective function and imposes constraints either on the SE or achievable rate, we propound a multiobjective optimization approach that can flexibly switch between the EE and SE functions or change the priority level of each function using a trade-off parameter. Our dynamic approach is more tractable than the conventional approaches and more convenient to realistic communication applications and scenarios. We prove that the multiobjective optimization of the EE and SE is equivalent to a simple problem that maximizes the achievable rate/SE and minimizes the total power consumption. Then we apply the generalized framework of the resource allocation for the EE-SE trade-off to optimally allocate the subcarriers’ power for orthogonal frequency division multiplexing (OFDM) with imperfect channel estimation. Finally, we use numerical results to discuss the choice of the trade-off parameter and study the effect of the estimation error, transmission power budget and channel-to-noise ratio on the multiobjective optimization.

Energy Efficiency - Spectral Efficiency Trade-off: A Multiobjective Optimization Approach

KAUST Repository

Amin, Osama; Bedeer, Ebrahim; Ahmed, Mohamed; Dobre, Octavia

2015-01-01

In this paper, we consider the resource allocation problem for energy efficiency (EE) - spectral efficiency (SE) trade-off. Unlike traditional research that uses the EE as an objective function and imposes constraints either on the SE or achievable rate, we propound a multiobjective optimization approach that can flexibly switch between the EE and SE functions or change the priority level of each function using a trade-off parameter. Our dynamic approach is more tractable than the conventional approaches and more convenient to realistic communication applications and scenarios. We prove that the multiobjective optimization of the EE and SE is equivalent to a simple problem that maximizes the achievable rate/SE and minimizes the total power consumption. Then we apply the generalized framework of the resource allocation for the EE-SE trade-off to optimally allocate the subcarriers’ power for orthogonal frequency division multiplexing (OFDM) with imperfect channel estimation. Finally, we use numerical results to discuss the choice of the trade-off parameter and study the effect of the estimation error, transmission power budget and channel-to-noise ratio on the multiobjective optimization.

ANTI-CORRELATED SOFT LAGS IN THE INTERMEDIATE STATE OF BLACK HOLE SOURCE GX 339-4

International Nuclear Information System (INIS)

Sriram, K.; Choi, C. S.; Rao, A. R.

2010-01-01

We report the few hundred second anti-correlated soft lags between soft and hard energy bands in the source GX 339-4 using RXTE observations. In one observation, anti-correlated soft lags were observed using the ISGRI/INTEGRAL hard energy band and the PCA/RXTE soft energy band light curves. The lags were observed when the source was in hard and soft intermediate states, i.e., in a steep power-law state. We found that the temporal and spectral properties were changed during the lag timescale. The anti-correlated soft lags are associated with spectral variability during which the geometry of the accretion disk is changed. The observed temporal and spectral variations are explained using the framework of truncated disk geometry. We found that during the lag timescale, the centroid frequency of quasi-periodic oscillation is decreased, the soft flux is decreased along with an increase in the hard flux, and the power-law index steepens together with a decrease in the disk normalization parameter. We argue that these changes could be explained if we assume that the hot corona condenses and forms a disk in the inner region of the accretion disk. The overall spectral and temporal changes support the truncated geometry of the accretion disk in the steep power-law state or in the intermediate state.

State Clean Energy Policies Analysis (SCEPA) Project: An Analysis of Renewable Energy Feed-in Tariffs in the United States (Revised)

Energy Technology Data Exchange (ETDEWEB)

Couture, T.; Cory, K.

2009-06-01

This report analyzes renewable energy feed-in tariff (FIT) policies and explores the different FIT policies currently implemented in the United States. It also discusses of a few proposed policies, the best practices in FIT policy design, and examines how FITs can be used to target state policy goals. The report covers current and potential future interactions between FITs and other state and federal energy policies while also providing an overview of the impacts FIT policies have in terms of renewable energy deployment, job creation, and economic development.

Anti-correlated spectral motion in bisphthalocyanines: evidence for vibrational modulation of electronic mixing.

Science.gov (United States)

Prall, Bradley S; Parkinson, Dilworth Y; Ishikawa, Naoto; Fleming, Graham R

2005-12-08

We exploit a coherently excited nuclear wave packet to study nuclear motion modulation of electronic structure in a metal bridged phthalocyanine dimer, lutetium bisphthalocyanine, which displays two visible absorption bands. We find that the nuclear coordinate influences the energies of the underlying exciton and charge resonance states as well as their interaction; the interplay of the various couplings creates unusual anti-correlated spectral motion in the two bands. Excited state relaxation dynamics are the same regardless of which transition is pumped, with decay time constants of 1.5 and 11 ps. The dynamics are analyzed using a three-state kinetic model after relaxation from one or two additional states faster than the experimental time resolution of 50-100 fs.

Soft drink effects on sensorimotor rhythm brain computer interface performance and resting-state spectral power.

Science.gov (United States)

Mundahl, John; Jianjun Meng; He, Jeffrey; Bin He

2016-08-01

Brain-computer interface (BCI) systems allow users to directly control computers and other machines by modulating their brain waves. In the present study, we investigated the effect of soft drinks on resting state (RS) EEG signals and BCI control. Eight healthy human volunteers each participated in three sessions of BCI cursor tasks and resting state EEG. During each session, the subjects drank an unlabeled soft drink with either sugar, caffeine, or neither ingredient. A comparison of resting state spectral power shows a substantial decrease in alpha and beta power after caffeine consumption relative to control. Despite attenuation of the frequency range used for the control signal, caffeine average BCI performance was the same as control. Our work provides a useful characterization of caffeine, the world's most popular stimulant, on brain signal frequencies and their effect on BCI performance.

6. State energy balance - 1978/1987 - Minas Gerais, Brazil

International Nuclear Information System (INIS)

1989-05-01

The energetic plan of Minas Gerais state and the steps such as energy balance, state potential energy identification, social and economic analysis, energetic flux, energy consumption is presented. (L.J.C.)

Fractional Stark state selective electric field ionization of very high-n Rydberg states of molecules

International Nuclear Information System (INIS)

Dietrich, H.; Mueller-Dethlefs, K.; Baranov, L.Y.

1996-01-01

For the first time fractional Stark state selective electric field ionization of very high-n (n approx-gt 250) molecular Rydberg states is observed. An open-quote open-quote offset close-quote close-quote electric pulse selectively ionizes the more fragile open-quote open-quote red close-quote close-quote (down shifted in energy) Stark states. The more resilient open-quote open-quote bluer close-quote close-quote, or up-shifted, ones survive and are shifted down in energy upon application of a second (open-quote open-quote probe close-quote close-quote) pulse of opposite direction (diabatic Stark states close-quote inversion). Hence, even for smaller probe than offset fields ionization is observed. The offset/probe ratio allows one to control spectral peak shapes in zero-kinetic-energy photoelectron spectroscopy. copyright 1995 The American Physical Society

Photoionization from metastable (1s2s) 1Se and 3Se states of the He atom for energies between the N=2 and 3 thresholds of He+

International Nuclear Information System (INIS)

Zhou, B.; Lin, C.D.

1994-01-01

Photoionization cross sections from the metastable state (1s2s) 1 Se of the He atom for photon energies between the He + (N=2) and (N=3) thresholds are calculated using the hyperspherical close-coupling method. The calculated spectra are convoluted with an energy resolution of 5.4 meV and are compared with the spectra for photoionization from the ground state. It is found that among the four possible outgoing channels, the 1sεp channel, which is the dominant channel for photoionization from the ground state, makes negligible contributions to the total cross sections for photoionization from the metastable state. As a result, the propensity rule derived from the ground-state photoionization no longer applies and more series of the doubly excited states are populated with significant spectral intensity in photoionization from the metastable state. Photoionization cross sections from the metastable (1s2s) 3 Se state are also calculated and analyzed

New energy levels of praseodymium with large angular momentum

Energy Technology Data Exchange (ETDEWEB)

Khan, Shamim; Siddiqui, Imran; Gamper, Bettina; Syed, Tanweer Iqbal; Guthoehrlein, Guenter H.; Windholz, Laurentius [Inst. f. Experimentalphysik, Techn. Univ. Graz, Petersgasse 16, A-8010 Graz (Austria)

2011-07-01

The electronic ground state configuration of praseodymium {sup 59}Pr{sub 141} is [Xe] 4f{sup 3}6s{sup 2}, with ground state level {sup 4}I{sub 9/2}. Our research is mainly devoted to find previously unknown energy levels by the investigation of spectral lines and their hyperfine structures. In a hollow cathode discharge lamp praseodymium atoms and ions in ground and excited states are excited to high lying states by laser light. The excitation source is a tunable ring-dye laser system, operated with R6G, Kiton Red, DCM and LD700. A high resolution Fourier transform spectrum is used for selecting promising excitation wavelengths. Then the laser wavelength is tuned to a strong hyperfine component of the spectral line to be investigated, and a search for fluorescence from excited levels is performed. From the observed hyperfine structure we determine J-values and hyperfine constants A of the combining levels. This information, together with excitation and fluorescence wavelengths, allows us to find the energies of involved new levels. Up to now we have discovered large number of previously unknown energy levels with various angular momentum values. We present here the data (energies, parities, angular momenta J, magnetic hyperfine constants A) of ca. 40 new, until now unknown energy levels with high angular momentum values: 15/2, 17/2, 19/2, 21/2.

Resource allocation for phantom cellular networks: Energy efficiency vs spectral efficiency

KAUST Repository

Abdelhady, Amr Mohamed Abdelaziz; Amin, Osama; Alouini, Mohamed-Slim

2016-01-01

Multi-tier heterogeneous networks have become an essential constituent for next generation cellular networks. Mean-while, energy efficiency (EE) has been considered a critical design criterion along with the traditional spectral efficiency (SE) metric. In this context, we study power and spectrum allocation for the recently proposed two-tier network architecture known as phantom cellular networks. The optimization framework includes both EE and SE, where we propose an algorithm that finds the SE and EE resource allocation strategies for phantom cellular networks. Then, we compare the performance of both design strategies versus the number of users, and phantom cells share of the total number of available resource blocks. We aim to investigate the effect of some system parameters to achieve improved SE performance at a non-significant loss in EE performance, or vice versa. It was found that increasing phantom cells share of resource blocks decreases the SE performance loss due to EE optimization when compared with the optimized SE performance. © 2016 IEEE.

Resource allocation for phantom cellular networks: Energy efficiency vs spectral efficiency

KAUST Repository

Abdelhady, Amr M.

2016-07-26

Multi-tier heterogeneous networks have become an essential constituent for next generation cellular networks. Mean-while, energy efficiency (EE) has been considered a critical design criterion along with the traditional spectral efficiency (SE) metric. In this context, we study power and spectrum allocation for the recently proposed two-tier network architecture known as phantom cellular networks. The optimization framework includes both EE and SE, where we propose an algorithm that finds the SE and EE resource allocation strategies for phantom cellular networks. Then, we compare the performance of both design strategies versus the number of users, and phantom cells share of the total number of available resource blocks. We aim to investigate the effect of some system parameters to achieve improved SE performance at a non-significant loss in EE performance, or vice versa. It was found that increasing phantom cells share of resource blocks decreases the SE performance loss due to EE optimization when compared with the optimized SE performance. © 2016 IEEE.

Estimated United States Transportation Energy Use 2005

Energy Technology Data Exchange (ETDEWEB)

Smith, C A; Simon, A J; Belles, R D

2011-11-09

A flow chart depicting energy flow in the transportation sector of the United States economy in 2005 has been constructed from publicly available data and estimates of national energy use patterns. Approximately 31,000 trillion British Thermal Units (trBTUs) of energy were used throughout the United States in transportation activities. Vehicles used in these activities include automobiles, motorcycles, trucks, buses, airplanes, rail, and ships. The transportation sector is powered primarily by petroleum-derived fuels (gasoline, diesel and jet fuel). Biomass-derived fuels, electricity and natural gas-derived fuels are also used. The flow patterns represent a comprehensive systems view of energy used within the transportation sector.

A Skew-t space-varying regression model for the spectral analysis of resting state brain activity.

Science.gov (United States)

Ismail, Salimah; Sun, Wenqi; Nathoo, Farouk S; Babul, Arif; Moiseev, Alexader; Beg, Mirza Faisal; Virji-Babul, Naznin

2013-08-01

It is known that in many neurological disorders such as Down syndrome, main brain rhythms shift their frequencies slightly, and characterizing the spatial distribution of these shifts is of interest. This article reports on the development of a Skew-t mixed model for the spatial analysis of resting state brain activity in healthy controls and individuals with Down syndrome. Time series of oscillatory brain activity are recorded using magnetoencephalography, and spectral summaries are examined at multiple sensor locations across the scalp. We focus on the mean frequency of the power spectral density, and use space-varying regression to examine associations with age, gender and Down syndrome across several scalp regions. Spatial smoothing priors are incorporated based on a multivariate Markov random field, and the markedly non-Gaussian nature of the spectral response variable is accommodated by the use of a Skew-t distribution. A range of models representing different assumptions on the association structure and response distribution are examined, and we conduct model selection using the deviance information criterion. (1) Our analysis suggests region-specific differences between healthy controls and individuals with Down syndrome, particularly in the left and right temporal regions, and produces smoothed maps indicating the scalp topography of the estimated differences.

Energy-level splitting of multicharged ions due to interaction with own radiation field

International Nuclear Information System (INIS)

Gajnutdinov, R.Kh.; Kalashnikov, K.K.

1991-01-01

The overlapping of the energy levels of He-like uranium states with identical principal quantum numbers is investigated. Results are presented of a numerical calculation of the states produced as a result of mixing of the 2s 1/2 8p 1/2 and 2p 1/2 8p 1/2 states and of the respective spectral lines. It is shown that the interaction between the ion and its own radiation field splits each of the overlapping energy levels into several sublevels. The sublevels are isolated from each to other such an extent that interference effects become insignificant. The shapes of the spectral lines differ pronouncedly from the Lorentz shape and many of the line are anomaously narrow

The spectral energy distributions of isolated neutron stars in the resonant cyclotron scattering model

Science.gov (United States)

Tong, Hao; Xu, Renxin

2013-03-01

The X-ray dim isolated neutron stars (XDINSs) are peculiar pulsar-like objects, characterized by their very well Planck-like spectrum. In studying their spectral energy distributions, the optical/UV excess is a long standing problem. Recently, Kaplan et al. (2011) have measured the optical/UV excess for all seven sources, which is understandable in the resonant cyclotron scattering (RCS) model previously addressed. The RCS model calculations show that the RCS process can account for the observed optical/UV excess for most sources. The flat spectrum of RX J2143.0+0654 may due to contribution from bremsstrahlung emission of the electron system in addition to the RCS process.

On the Effective Equation of State of Dark Energy

DEFF Research Database (Denmark)

Sloth, Martin Snoager

2010-01-01

In an effective field theory model with an ultraviolet momentum cutoff, there is a relation between the effective equation of state of dark energy and the ultraviolet cutoff scale. It implies that a measure of the equation of state of dark energy different from minus one, does not rule out vacuum...... energy as dark energy. It also indicates an interesting possibility that precise measurements of the infrared properties of dark energy can be used to probe the ultraviolet cutoff scale of effective quantum field theory coupled to gravity. In a toy model with a vacuum energy dominated universe...... with a Planck scale cutoff, the dark energy effective equation of state is -0.96....

Spectral functions from Quantum Monte Carlo

International Nuclear Information System (INIS)

Silver, R.N.

1989-01-01

In his review, D. Scalapino identified two serious limitations on the application of Quantum Monte Carlo (QMC) methods to the models of interest in High T c Superconductivity (HTS). One is the ''sign problem''. The other is the ''analytic continuation problem'', which is how to extract electron spectral functions from QMC calculations of the imaginary time Green's functions. Through-out this Symposium on HTS, the spectral functions have been the focus for the discussion of normal state properties including the applicability of band theory, Fermi liquid theory, marginal Fermi liquids, and novel non-perturbative states. 5 refs., 1 fig

THE INFLUENCE OF THE EXTREME ULTRAVIOLET SPECTRAL ENERGY DISTRIBUTION ON THE STRUCTURE AND COMPOSITION OF THE UPPER ATMOSPHERE OF EXOPLANETS

Energy Technology Data Exchange (ETDEWEB)

Guo, J. H. [Yunnan Observatories, Chinese Academy of Sciences, P.O. Box 110, Kunming 650011 (China); Ben-Jaffel, Lotfi, E-mail: guojh@ynao.ac.cn, E-mail: bjaffel@iap.fr [Sorbonne Universités, UPMC Univ. Paris 6 et CNRS, UMR 7095, Institut Astrophysique de Paris, F-75014 Paris (France)

2016-02-20

By varying the profiles of stellar extreme ultraviolet (EUV) spectral energy distributions (SEDs), we tested the influences of stellar EUV SEDs on the physical and chemical properties of an escaping atmosphere. We apply our model to study four exoplanets: HD 189733b, HD 209458b, GJ 436b, and Kepler-11b. We find that the total mass loss rates of an exoplanet, which are determined mainly by the integrated fluxes, are moderately affected by the profiles of the EUV SED, but the composition and species distributions in the atmosphere can be dramatically modified by the different profiles of the EUV SED. For exoplanets with a high hydrodynamic escape parameter (λ), the amount of atomic hydrogen produced by photoionization at different altitudes can vary by one to two orders of magnitude with the variation of stellar EUV SEDs. The effect of photoionization of H is prominent when the EUV SED is dominated by the low-energy spectral region (400–900 Å), which pushes the transition of H/H{sup +} to low altitudes. In contrast, the transition of H/H{sup +} moves to higher altitudes when most photons are concentrated in the high-energy spectral region (50–400 Å). For exoplanets with a low λ, the lower temperatures of the atmosphere make many chemical reactions so important that photoionization alone can no longer determine the composition of the escaping atmosphere. For HD 189733b, it is possible to explain the time variability of Lyα between 2010 and 2011 by a change in the EUV SED of the host K-type star, yet invoking only thermal H i in the atmosphere.

Limiting absorption principle at low energies for a mathematical model of weak interaction: the decay of a boson

International Nuclear Information System (INIS)

Barbarouxa, J.M.; Guillot, J.C.

2009-01-01

We study the spectral properties of a Hamiltonian describing the weak decay of spin 1 massive bosons into the full family of leptons. We prove that the considered Hamiltonian is self-adjoint, with a unique ground state and we derive a Mourre estimate and a limiting absorption principle above the ground state energy and below the first threshold, for a sufficiently small coupling constant. As a corollary, we prove absence of eigenvalues and absolute continuity of the energy spectrum in the same spectral interval. (authors)

Spectral entropy and haemodynamic response to surgery during ...

African Journals Online (AJOL)

Adele

Spectral entropy and haemodynamic response to surgery during sevoflurane anaesthesia. Introduction. Apart from somatic responses, surgery also evokes autonomic responses, including haemodynamic responses. Spectral entropy has been validated as a means to monitor the hypnotic state during sevoflurane ...

The peculiarities of spectral manifestations of high-voltage electric discharge in different phase states of ion systems.

Science.gov (United States)

Gafurov, M M; Aliev, A R; Ataev, M B; Rabadanov, K Sh

2013-10-01

The effects of high-voltage pulsed discharge (HVPD activation) on vibrational spectra of ion salt systems have been studied. The peculiarities of spectral display of HVPD in ion melts and aqueous solutions of electrolytes, in ion-conducting phases of crystalline and glassy salt systems have been investigated. After HVPD a salt system is in non-equilibrium activated state. In the activated state of a salt system, the relaxation time of the vibrational excited states of molecular ions is shorter than in the equilibrium state if the vibrational relaxation rate increases with temperature in the system. For those systems for which the relaxation rate decreases at elevated temperatures, the relaxation time of the vibrational excited states of molecular ions is longer than in the equilibrium state. HVPD activation of a salt system can change the configuration of the electron shell of molecular ions. Therefore, the lifetime values of activated state of salt systems are abnormally large. Copyright © 2013 Elsevier B.V. All rights reserved.

The three constituencies of the state: why the state has lost unifying energy.

Science.gov (United States)

King, Desmond; Le Galès, Patrick

2017-11-01

We address resurgent populism by examining structural processes of state transformation in the UK, the US and France. Scholars stress the 'unifying energy of the state', a set of institutions and policies capable of limiting inequalities and defending legal regimes. One characteristic of modern Western statehood were packages of policies designed to integrate social groups and territories in part by ensuring common standards of provision and social citizenship across the nation state. This echoes James Scott's critical analysis of the modernist project of the state (1998). This 'unifying energy' had different origins including nationalist movements, combatting external influence or powers, war, and preparing citizens for the rigours of industrialization. Overcoming class differences and territorial differences (including cultural, social and economic differences) was a major source of mobilization to feed this 'unifying energy of the state' in France, Italy or Spain for instance. Political and cultural identities are related in significant part to respective nation states. We argue that this 'unifying energy' was an essential component of statehood in Europe and in the US. It is now largely lost. We explain why and the significance of its displacement. © London School of Economics and Political Science 2017.

Energy balance from Bahia state 2013 - series 1996-2012

International Nuclear Information System (INIS)

2013-01-01

This Energy Balance from Bahia, Brazil, presents six chapters, as follows: the chapter 1 approaches the profile of the energy system, showing the structure of the Bahia state energy matrix in the year of 2012, and the modifications occurred during the period of 1996-2012. Then the consolidated information are presented, from production to final consumption, for the set of primary and secondary sources, as well as comparative tables of states x national production of major energy production; the chapter 2 analyses the development, during the period of 1996-2012, in energy supply according to the Primary and Secondary sources; the chapter 3 comprised the evolution of energy consumption by sources and according the social-economic sectors; chapter 4 focus, within a broader view, the evolution of self-sufficiency energy state, confronting the production of primary energy to the total energy demand; in chapter 5 is given the status of the Energy Transformation Centers of the state, highlighting the balances of the Refinery Landulpho Alves (RLAM) and the Power Plants of Public Service and Self-Producer and the chapter 6 contains the consolidated matrixes expressed in the years of 1980, 1985 and 1990-2012

Energy balance from Bahia state 2011 - series: 1994-2010

International Nuclear Information System (INIS)

2011-01-01

The present Energy Balance is constituted of six chapters, as follows: the chapter 1 approaches the profile of the energy system, showing the structure of the Bahia state energy matrix i n the year of 2010, and the modifications occurred during the period of 1994-2010; the chapter 2 analyses the evolution during the period of 1994-2010 of the energy offer with aspects of production, exports, imports and consumption; the chapter 3 comprised the evolution of energy consumption by sources and social-economic sectors; chapter 4 focus the evolution of state energy self-sufficiency, confronting the primary energy production with the energy total demand; the chapter 5 contains the balance of the energy transformation centers of the Bahia state; and the chapter 6 contains the consolidated matrixes expressed in the period of 1980, 1985 and 1990-2010

An Evaluation of State Energy Program Accomplishments: 2002 Program Year

Energy Technology Data Exchange (ETDEWEB)

Schweitzer, M.

2005-07-13

The U.S. Department of Energy's (DOE's) State Energy Program (SEP) was established in 1996 by merging the State Energy Conservation Program (SECP) and the Institutional Conservation Program (ICP), both of which had been in existence since 1976 (U.S. DOE 2001a). The SEP provides financial and technical assistance for a wide variety of energy efficiency and renewable energy activities undertaken by the states and territories. SEP provides money to each state and territory according to a formula that accounts for population and energy use. In addition to these ''Formula Grants'', SEP ''Special Project'' funds are made available on a competitive basis to carry out specific types of energy efficiency and renewable energy activities (U.S. DOE 2003c). The resources provided by DOE typically are augmented by money and in-kind assistance from a number of sources, including other federal agencies, state and local governments, and the private sector. The states SEP efforts include several mandatory activities, such as establishing lighting efficiency standards for public buildings, promoting car and vanpools and public transportation, and establishing policies for energy-efficient government procurement practices. The states and territories also engage in a broad range of optional activities, including holding workshops and training sessions on a variety of topics related to energy efficiency and renewable energy, providing energy audits and building retrofit services, offering technical assistance, supporting loan and grant programs, and encouraging the adoption of alternative energy technologies. The scope and variety of activities undertaken by the various states and territories is extremely broad, and this reflects the diversity of conditions and needs found across the country and the efforts of participating states and territories to respond to them. The purpose of this report is to present estimates of the energy and

Mean excitation energies for molecular ions

Energy Technology Data Exchange (ETDEWEB)

Jensen, Phillip W.K.; Sauer, Stephan P.A. [Department of Chemistry, University of Copenhagen, Copenhagen (Denmark); Oddershede, Jens [Department of Physics, Chemistry, and Pharmacy, University of Southern Denmark, Odense (Denmark); Quantum Theory Project, Departments of Physics and Chemistry, University of Florida, Gainesville, FL (United States); Sabin, John R., E-mail: sabin@qtp.ufl.edu [Department of Physics, Chemistry, and Pharmacy, University of Southern Denmark, Odense (Denmark); Quantum Theory Project, Departments of Physics and Chemistry, University of Florida, Gainesville, FL (United States)

2017-03-01

The essential material constant that determines the bulk of the stopping power of high energy projectiles, the mean excitation energy, is calculated for a range of smaller molecular ions using the RPA method. It is demonstrated that the mean excitation energy of both molecules and atoms increase with ionic charge. However, while the mean excitation energies of atoms also increase with atomic number, the opposite is the case for mean excitation energies for molecules and molecular ions. The origin of these effects is explained by considering the spectral representation of the excited state contributing to the mean excitation energy.

Study on spectral entropy of two-phase flow density wave instability

International Nuclear Information System (INIS)

Zhang Zuoyi

1992-05-01

By using mathematic proof, spectral entropy calculations for simple examples and a practical two-phase flow system, it has been proved that under the same stochastic input, the output spectral entropy of a stable linear system is in maximum, while for an unstable linear system, its entropy is in relative lower level. Because the spectral entropy describes the output uncertainty of a system and the second law of thermodynamics rules the direction of natural tendency, the spontaneous process can develop only toward the direction of uncertainty increasing, and the opposite is impossible. It seems that the physical mechanism of the stability of a system can be explained as following: Any deviation from its original state of a stable system will reduce the spectral entropy and violate the natural tendency so that the system will return to original state. On the contrary, the deviation from its original state of an unstable system will increase the spectral entropy that will enhance the deviation and the system will be further away from its original state

Spectral ellipsometry of nanodiamond composite

International Nuclear Information System (INIS)

Yastrebov, S.G.; Ivanov-Omskij, V.I.; Gordeev, S.K.; Garriga, M.; Alonso, I.A.

2006-01-01

Methods of spectral ellipsometry were applied for analysis of optical properties of nanodiamond based composite in spectral region 1.4-5 eV. The nanocomposite was synthesized by molding of ultradispersed nanodiamond powder in the course of heterogeneous chemical reaction of decomposition of methane, forming pyrocarbon interconnecting nanodiamond grains. The energy of σ + π plasmon of pyrocarbon component of nanodiamond composite was restored which proves to be ∼ 24 eV; using this value, an estimation was done of pyrocarbon matrix density, which occurs to be 2 g/cm 3 [ru

State energy severance taxes, 1985-1993

International Nuclear Information System (INIS)

1995-09-01

This report analyzes changes in aggregate and State-level energy severance taxes for 1985 through 1993. Data are presented for crude oil, natural gas, and coal. The report highlights trends in severance tax receipts relative to energy prices and production, using severance tax data published by the Bureau of the Census of the US Department of Commerce and production data published by the Energy Information Administration

Uncertainty Analysis of Spectral Irradiance Reference Standards Used for NREL Calibrations

Energy Technology Data Exchange (ETDEWEB)

Habte, A.; Andreas, A.; Reda, I.; Campanelli, M.; Stoffel, T.

2013-05-01

Spectral irradiance produced by lamp standards such as the National Institute of Standards and Technology (NIST) FEL-type tungsten halogen lamps are used to calibrate spectroradiometers at the National Renewable Energy Laboratory. Spectroradiometers are often used to characterize spectral irradiance of solar simulators, which in turn are used to characterize photovoltaic device performance, e.g., power output and spectral response. Therefore, quantifying the calibration uncertainty of spectroradiometers is critical to understanding photovoltaic system performance. In this study, we attempted to reproduce the NIST-reported input variables, including the calibration uncertainty in spectral irradiance for a standard NIST lamp, and quantify uncertainty for measurement setup at the Optical Metrology Laboratory at the National Renewable Energy Laboratory.

Modelling performance of a small array of Wave Energy Converters: Comparison of Spectral and Boussinesq models

International Nuclear Information System (INIS)

Greenwood, Charles; Christie, David; Venugopal, Vengatesan; Morrison, James; Vogler, Arne

2016-01-01

This paper presents results from numerical simulations of three Oscillating Wave Surge Converters (OWSC) using two different computational models, Boussinesq wave (BW) and Spectral wave (SW) of the commercial software suite MIKE. The simulation of a shallow water wave farm applies alternative methods for implementing a frequency dependent absorption in both the BW and SW models, where energy extraction is based on experimental data from a scaled Oyster device. The effects of including wave diffraction within the SW model is tested by using diffraction smoothing steps and various directional wave conditions. The results of this study reveal important information on the models realms of validity that is heavily dependent on the incident sea state and the removal of diffraction for the SW model. This yields an increase in simulation accuracy for far-field disturbances when diffraction is entirely removed. This highlights specific conditions where the BW and SW model may thrive but also regions where reduced performance is observed. The results presented in this paper have not been validated with real sea site wave device array performance, however, the methodology described would be useful to device developers to arrive at preliminary decisions on array configurations and to minimise negative environmental impacts.

Effective spectral function for quasielastic scattering on nuclei

Energy Technology Data Exchange (ETDEWEB)

Bodek, A.; Coopersmith, B. [University of Rochester, Department of Physics and Astronomy, Rochester, NY (United States); Christy, M.E. [Hampton University, Hampton, VA (United States)

2014-10-15

Spectral functions that are used in neutrino event, generators to model quasielastic (QE) scattering from nuclear targets include Fermi gas, Local Thomas Fermi gas (LTF), Bodek-Ritchie Fermi gas with high momentum tail, and the Benhar-Fantoni two dimensional spectral function. We find that the ν dependence of predictions of these spectral functions for the QE differential cross sections (d{sup 2}σ/dQ{sup 2}dν) are in disagreement with the prediction of the ψ' superscaling function which is extracted from fits to quasielastic electron scattering data on nuclear targets. It is known that spectral functions do not fully describe quasielastic scattering because they only model the initial state. Final state interactions distort the shape of the differential cross section at the peak and increase the cross section at the tails of the distribution. We show that the kinematic distributions predicted by the ψ' superscaling formalism can be well described with a modified effective spectral function (ESF). By construction, models using ESF in combination with the transverse enhancement contribution correctly predict electron QE scattering data. (orig.)

Effective spectral function for quasielastic scattering on nuclei

International Nuclear Information System (INIS)

Bodek, A.; Coopersmith, B.; Christy, M.E.

2014-01-01

Spectral functions that are used in neutrino event, generators to model quasielastic (QE) scattering from nuclear targets include Fermi gas, Local Thomas Fermi gas (LTF), Bodek-Ritchie Fermi gas with high momentum tail, and the Benhar-Fantoni two dimensional spectral function. We find that the ν dependence of predictions of these spectral functions for the QE differential cross sections (d 2 σ/dQ 2 dν) are in disagreement with the prediction of the ψ' superscaling function which is extracted from fits to quasielastic electron scattering data on nuclear targets. It is known that spectral functions do not fully describe quasielastic scattering because they only model the initial state. Final state interactions distort the shape of the differential cross section at the peak and increase the cross section at the tails of the distribution. We show that the kinematic distributions predicted by the ψ' superscaling formalism can be well described with a modified effective spectral function (ESF). By construction, models using ESF in combination with the transverse enhancement contribution correctly predict electron QE scattering data. (orig.)

Energy calibration issues in nuclear resonant vibrational spectroscopy: observing small spectral shifts and making fast calibrations.

Science.gov (United States)

Wang, Hongxin; Yoda, Yoshitaka; Dong, Weibing; Huang, Songping D

2013-09-01

The conventional energy calibration for nuclear resonant vibrational spectroscopy (NRVS) is usually long. Meanwhile, taking NRVS samples out of the cryostat increases the chance of sample damage, which makes it impossible to carry out an energy calibration during one NRVS measurement. In this study, by manipulating the 14.4 keV beam through the main measurement chamber without moving out the NRVS sample, two alternative calibration procedures have been proposed and established: (i) an in situ calibration procedure, which measures the main NRVS sample at stage A and the calibration sample at stage B simultaneously, and calibrates the energies for observing extremely small spectral shifts; for example, the 0.3 meV energy shift between the 100%-(57)Fe-enriched [Fe4S4Cl4](=) and 10%-(57)Fe and 90%-(54)Fe labeled [Fe4S4Cl4](=) has been well resolved; (ii) a quick-switching energy calibration procedure, which reduces each calibration time from 3-4 h to about 30 min. Although the quick-switching calibration is not in situ, it is suitable for normal NRVS measurements.

Spectral function from Reduced Density Matrix Functional Theory

Science.gov (United States)

Romaniello, Pina; di Sabatino, Stefano; Berger, Jan A.; Reining, Lucia

2015-03-01

In this work we focus on the calculation of the spectral function, which determines, for example, photoemission spectra, from reduced density matrix functional theory. Starting from its definition in terms of the one-body Green's function we derive an expression for the spectral function that depends on the natural occupation numbers and on an effective energy which accounts for all the charged excitations. This effective energy depends on the two-body as well as higher-order density matrices. Various approximations to this expression are explored by using the exactly solvable Hubbard chains.

Geothermal Energy Potential in Western United States

Science.gov (United States)

Pryde, Philip R.

1977-01-01

Reviews types of geothermal energy sources in the western states, including hot brine systems and dry steam systems. Conversion to electrical energy is a major potential use of geothermal energy, although it creates environmental disruptions such as noise, corrosion, and scaling of equipment. (AV)

Spectral synchronicity in brain signals

KAUST Repository

de Jesus Euan Campos, Carolina; Ombao, Hernando; Ortega, Joaquí n

2018-01-01

This paper addresses the problem of identifying brain regions with similar oscillatory patterns detected from electroencephalograms. We introduce the hierarchical spectral merger (HSM) clustering method where the feature of interest is the spectral curve and the similarity metric used is the total variance distance. The HSM method is compared with clustering using features derived from independent-component analysis. Moreover, the HSM method is applied to 2 different electroencephalogram datasets. The first was recorded at resting state where the participant was not engaged in any cognitive task; the second was recorded during a spontaneous epileptic seizure. The results of the analyses using the HSM method demonstrate that clustering could evolve over the duration of the resting state and during epileptic seizure.

Spectral synchronicity in brain signals

KAUST Repository

de Jesus Euan Campos, Carolina

2018-05-04

This paper addresses the problem of identifying brain regions with similar oscillatory patterns detected from electroencephalograms. We introduce the hierarchical spectral merger (HSM) clustering method where the feature of interest is the spectral curve and the similarity metric used is the total variance distance. The HSM method is compared with clustering using features derived from independent-component analysis. Moreover, the HSM method is applied to 2 different electroencephalogram datasets. The first was recorded at resting state where the participant was not engaged in any cognitive task; the second was recorded during a spontaneous epileptic seizure. The results of the analyses using the HSM method demonstrate that clustering could evolve over the duration of the resting state and during epileptic seizure.

The ground state energy of a classical gas

International Nuclear Information System (INIS)

Conlon, J.G.

1983-01-01

The ground state energy of a classical gas is treated using a probability function for the position of the particles and a potential function. The lower boundary for the energy when the particle number is large is defined as ground state energy. The coulomb gas consisting of positive and negative particles is also treated (fixed and variable density case) the stability of the relativistic system is investigated as well. (H.B.)

Planck Early Results. XV. Spectral Energy Distributions and Radio Continuum Spectra of Northern Extragalactic Radio Sources

Science.gov (United States)

Aatrokoski, J.; Ade, P. A. R.; Aghanim, N.; Aller, H. D.; Aller, M. F.; Angelakis, E.; Amaud, M.; Ashdown, M.; Aumont, J.; Baccigalupi, C.;

Critically Evaluated Energy Levels, Spectral Lines, Transition Probabilities, and Intensities of Singly Ionized Vanadium (V ii)

Energy Technology Data Exchange (ETDEWEB)

Saloman, Edward B. [Dakota Consulting, Inc., 1110 Bonifant Street, Suite 310, Silver Spring, MD 20910 (United States); Kramida, Alexander [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States)

2017-08-01

The energy levels, observed spectral lines, and transition probabilities of singly ionized vanadium, V ii, have been compiled. The experimentally derived energy levels belong to the configurations 3 d {sup 4}, 3 d {sup 3} ns ( n  = 4, 5, 6), 3 d {sup 3} np , and 3 d {sup 3} nd ( n  = 4, 5), 3 d {sup 3}4 f , 3 d {sup 2}4 s {sup 2}, and 3 d {sup 2}4 s 4 p . Also included are values for some forbidden lines that may be of interest to the astrophysical community. Experimental Landé g -factors and leading percentages for the levels are included when available, as well as Ritz wavelengths calculated from the energy levels. Wavelengths and transition probabilities are reported for 3568 and 1896 transitions, respectively. From the list of observed wavelengths, 407 energy levels are determined. The observed intensities, normalized to a common scale, are provided. From the newly optimized energy levels, a revised value for the ionization energy is derived, 118,030(60) cm{sup −1}, corresponding to 14.634(7) eV. This is 130 cm{sup −1} higher than the previously recommended value from Iglesias et al.

Evaluating the capabilities of vegetation spectral indices on chlorophyll content estimation at Sentinel-2 spectral resolutions

Science.gov (United States)

Sun, Qi; Jiao, Quanjun; Dai, Huayang

2018-03-01

Chlorophyll is an important pigment in green plants for photosynthesis and obtaining the energy for growth and development. The rapid, nondestructive and accurate estimation of chlorophyll content is significant for understanding the crops growth, monitoring the disease and insect, and assessing the yield of crops. Sentinel-2 equipped with the Multi-Spectral Instrument (MSI), which will provide images with high spatial, spectral and temporal resolution. It covers the VNIR/SWIR spectral region in 13 bands and incorporates two new spectral bands in the red-edge region and a spatial resolution of 20nm, which can be used to derive vegetation indices using red-edge bands. In this paper, we will focus on assessing the potential of vegetation spectral indices for retrieving chlorophyll content from Sentinel-2 at different angles. Subsequently, we used in-situ spectral data and Sentinel-2 data to test the relationship between VIs and chlorophyll content. The REP, MTCI, CIred-edge, CIgreen, Macc01, TCARI/OSAVI [705,750], NDRE1 and NDRE2 were calculated. NDRE2 index displays a strongly similar result for hyperspectral and simulated Sentinel-2 spectral bands (R2 =0.53, R2 =0.51, for hyperspectral and Sentinel-2, respectively). At different observation angles, NDRE2 has the smallest difference in performance (R2 = 0.51, R2 =0.64, at 0° and 15° , respectively).

Spectral dependence of third-order nonlinear optical properties in InN

International Nuclear Information System (INIS)

Ahn, H.; Lee, M.-T.; Chang, Y.-M.

2014-01-01

We report on the nonlinear optical properties of InN measured in a wide near-infrared spectral range with the femtosecond Z-scan technique. The above-bandgap nonlinear absorption in InN is found to originate from the saturation of absorption by the band-state-filling and its cross-section increases drastically near the bandgap energy. With below-bandgap excitation, the nonlinear absorption undergoes a transition from saturation absorption (SA) to reverse-SA (RSA), attributed to the competition between SA of band-tail states and two-photon-related RSA. The measured large nonlinear refractive index of the order of 10 −10 cm 2 /W indicates InN as a potential material for all-optical switching and related applications

Spectral CT of carotid atherosclerotic plaque: comparison with histology

Energy Technology Data Exchange (ETDEWEB)

Zainon, R.; Doesburg, R.M. [University of Canterbury, Department of Physics and Astronomy, Christchurch (New Zealand); Ronaldson, J.P.; Gieseg, S.P. [University of Otago, Centre for Bioengineering, Christchurch (New Zealand); Janmale, T. [University of Canterbury, Free Radical Biochemistry Laboratory, School of Biological Sciences, Christchurch (New Zealand); Scott, N.J. [University of Otago, Department of Medicine, Christchurch (New Zealand); Buckenham, T.M. [University of Otago, Department of Academic Radiology, Christchurch (New Zealand); Butler, A.P.H. [University of Otago, Centre for Bioengineering, Christchurch (New Zealand); University of Otago, Department of Academic Radiology, Christchurch (New Zealand); University of Canterbury, Department of Electrical and Computer Engineering, Christchurch (New Zealand); European Organisation for Nuclear Research (CERN), Geneva (Switzerland); Butler, P.H. [University of Canterbury, Department of Physics and Astronomy, Christchurch (New Zealand); European Organisation for Nuclear Research (CERN), Geneva (Switzerland); Roake, J.A. [Christchurch Hospital, Department of Vascular, Endovascular and Transplant Surgery, Christchurch (New Zealand); Anderson, N.G. [University of Otago, Centre for Bioengineering, Christchurch (New Zealand); University of Otago, Department of Academic Radiology, Christchurch (New Zealand); University of Otago, Christchurch, Department of Radiology, PO Box 4345, Christchurch (New Zealand)

2012-12-15

To distinguish components of vulnerable atherosclerotic plaque by imaging their energy response using spectral CT and comparing images with histology. After spectroscopic calibration using phantoms of plaque surrogates, excised human carotid atherosclerotic plaques were imaged using MARS CT using a photon-processing detector with a silicon sensor layer and microfocus X-ray tube (50 kVp, 0.5 mA) at 38-{mu}m voxel size. The plaques were imaged, sectioned and re-imaged using four threshold energies: 10, 16, 22 and 28 keV; then sequentially stained with modified Von Kossa, Perl's Prussian blue and Oil-Red O, and photographed. Relative Hounsfield units across the energies were entered into a linear algebraic material decomposition model to identify the unknown plaque components. Lipid, calcium, iron and water-like components of plaque have distinguishable energy responses to X-ray, visible on spectral CT images. CT images of the plaque surface correlated very well with histological photographs. Calcium deposits (>1,000 {mu}m) in plaque are larger than iron deposits (<100 {mu}m), but could not be distinguished from each other within the same voxel using the energy range available. Spectral CT displays energy information in image form at high spatial resolution, enhancing the intrinsic contrast of lipid, calcium and iron within atheroma. (orig.)

40 CFR Table E-2 to Subpart E of... - Spectral Energy Distribution and Permitted Tolerance for Conducting Radiative Tests

Science.gov (United States)

2010-07-01

... Permitted Tolerance for Conducting Radiative Tests E Table E-2 to Subpart E of Part 53 Protection of... Reference Methods and Class I and Class II Equivalent Methods for PM2.5 or PM10â2.5 Pt. 53, Subpt. E, Table E-2 Table E-2 to Subpart E of Part 53—Spectral Energy Distribution and Permitted Tolerance for...

FERMI LARGE AREA TELESCOPE OBSERVATIONS OF MARKARIAN 421: THE MISSING PIECE OF ITS SPECTRAL ENERGY DISTRIBUTION

International Nuclear Information System (INIS)

Abdo, A. A.; Ackermann, M.; Ajello, M.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Borgland, A. W.; Buehler, R.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bonamente, E.; Bouvier, A.; Brigida, M.; Bruel, P.

2011-01-01

We report on the γ-ray activity of the high-synchrotron-peaked BL Lacertae object Markarian 421 (Mrk 421) during the first 1.5 years of Fermi operation, from 2008 August 5 to 2010 March 12. We find that the Large Area Telescope (LAT) γ-ray spectrum above 0.3 GeV can be well described by a power-law function with photon index Γ = 1.78 ± 0.02 and average photon flux F(> 0.3 GeV) = (7.23 ± 0.16) x 10 -8 ph cm -2 s -1 . Over this time period, the Fermi-LAT spectrum above 0.3 GeV was evaluated on seven-day-long time intervals, showing significant variations in the photon flux (up to a factor ∼3 from the minimum to the maximum flux) but mild spectral variations. The variability amplitude at X-ray frequencies measured by RXTE/ASM and Swift/BAT is substantially larger than that in γ-rays measured by Fermi-LAT, and these two energy ranges are not significantly correlated. We also present the first results from the 4.5 month long multifrequency campaign on Mrk 421, which included the VLBA, Swift, RXTE, MAGIC, the F-GAMMA, GASP-WEBT, and other collaborations and instruments that provided excellent temporal and energy coverage of the source throughout the entire campaign (2009 January 19 to 2009 June 1). During this campaign, Mrk 421 showed a low activity at all wavebands. The extensive multi-instrument (radio to TeV) data set provides an unprecedented, complete look at the quiescent spectral energy distribution (SED) for this source. The broadband SED was reproduced with a leptonic (one-zone synchrotron self-Compton) and a hadronic model (synchrotron proton blazar). Both frameworks are able to describe the average SED reasonably well, implying comparable jet powers but very different characteristics for the blazar emission site.

Energy Demand Modeling Methodology of Key State Transitions of Turning Processes

Directory of Open Access Journals (Sweden)

Shun Jia

2017-04-01

Full Text Available Energy demand modeling of machining processes is the foundation of energy optimization. Energy demand of machining state transition is integral to the energy requirements of the machining process. However, research focus on energy modeling of state transition is scarce. To fill this gap, an energy demand modeling methodology of key state transitions of the turning process is proposed. The establishment of an energy demand model of state transition could improve the accuracy of the energy model of the machining process, which also provides an accurate model and reliable data for energy optimization of the machining process. Finally, case studies were conducted on a CK6153i CNC lathe, the results demonstrating that predictive accuracy with the proposed method is generally above 90% for the state transition cases.

Identification of Raman peaks of high-T{sub c} cuprates in normal state through density of states

Energy Technology Data Exchange (ETDEWEB)

Bishoyi, K.C. [P.G. Department of Physics, F.M. College (Auto.), Balasore 756 001 (India)]. E-mail: bishoyi@iopb.res.in; Rout, G.C. [Condensed Matter Physics Group, Govt. Science College, Chatrapur 761 020, Orissa (India); Behera, S.N. [Physics Enclave, H.I.G.-23/1, Housing Board Phase-I, Chandrasekharpur, Bhubaneswar 7510016 (India)

2007-05-31

We present a microscopic theory to explain and identify the Raman spectral peaks of high-T{sub c} cuprates R{sub 2-x}M{sub x}CuO{sub 4} in the normal state. We used electronic Hamiltonian prescribed by Fulde in presence of anti-ferromagnetism. Phonon interaction to the hybridization between the conduction electrons of the system and the f-electrons has been incorporated in the calculation. The phonon spectral density is calculated by the Green's function technique of Zubarev at zero wave vector and finite (room) temperature limit. The four Raman active peaks (P{sub 1}-P{sub 4}) representing the electronic states of the atomic sub-systems of the cuprate system are identified by the calculated quasi-particle energy bands and electron density of states (DOS). The effect of interactions on these peaks are also explained.

Spectral gamuts and spectral gamut mapping

Science.gov (United States)

Rosen, Mitchell R.; Derhak, Maxim W.

2006-01-01

All imaging devices have two gamuts: the stimulus gamut and the response gamut. The response gamut of a print engine is typically described in CIE colorimetry units, a system derived to quantify human color response. More fundamental than colorimetric gamuts are spectral gamuts, based on radiance, reflectance or transmittance units. Spectral gamuts depend on the physics of light or on how materials interact with light and do not involve the human's photoreceptor integration or brain processing. Methods for visualizing a spectral gamut raise challenges as do considerations of how to utilize such a data-set for producing superior color reproductions. Recent work has described a transformation of spectra reduced to 6-dimensions called LabPQR. LabPQR was designed as a hybrid space with three explicit colorimetric axes and three additional spectral reconstruction axes. In this paper spectral gamuts are discussed making use of LabPQR. Also, spectral gamut mapping is considered in light of the colorimetric-spectral duality of the LabPQR space.

Sparse modeling of EELS and EDX spectral imaging data by nonnegative matrix factorization

Energy Technology Data Exchange (ETDEWEB)

Shiga, Motoki, E-mail: shiga_m@gifu-u.ac.jp [Department of Electrical, Electronic and Computer Engineering, Gifu University, 1-1, Yanagido, Gifu 501-1193 (Japan); Tatsumi, Kazuyoshi; Muto, Shunsuke [Advanced Measurement Technology Center, Institute of Materials and Systems for Sustainability, Nagoya University, Chikusa-ku, Nagoya 464-8603 (Japan); Tsuda, Koji [Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8561 (Japan); Center for Materials Research by Information Integration, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan); Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology, 2-4-7 Aomi Koto-ku, Tokyo 135-0064 (Japan); Yamamoto, Yuta [High-Voltage Electron Microscope Laboratory, Institute of Materials and Systems for Sustainability, Nagoya University, Chikusa-ku, Nagoya 464-8603 (Japan); Mori, Toshiyuki [Environment and Energy Materials Division, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan); Tanji, Takayoshi [Division of Materials Research, Institute of Materials and Systems for Sustainability, Nagoya University, Chikusa-ku, Nagoya 464-8603 (Japan)

2016-11-15

Advances in scanning transmission electron microscopy (STEM) techniques have enabled us to automatically obtain electron energy-loss (EELS)/energy-dispersive X-ray (EDX) spectral datasets from a specified region of interest (ROI) at an arbitrary step width, called spectral imaging (SI). Instead of manually identifying the potential constituent chemical components from the ROI and determining the chemical state of each spectral component from the SI data stored in a huge three-dimensional matrix, it is more effective and efficient to use a statistical approach for the automatic resolution and extraction of the underlying chemical components. Among many different statistical approaches, we adopt a non-negative matrix factorization (NMF) technique, mainly because of the natural assumption of non-negative values in the spectra and cardinalities of chemical components, which are always positive in actual data. This paper proposes a new NMF model with two penalty terms: (i) an automatic relevance determination (ARD) prior, which optimizes the number of components, and (ii) a soft orthogonal constraint, which clearly resolves each spectrum component. For the factorization, we further propose a fast optimization algorithm based on hierarchical alternating least-squares. Numerical experiments using both phantom and real STEM-EDX/EELS SI datasets demonstrate that the ARD prior successfully identifies the correct number of physically meaningful components. The soft orthogonal constraint is also shown to be effective, particularly for STEM-EELS SI data, where neither the spatial nor spectral entries in the matrices are sparse. - Highlights: • Automatic resolution of chemical components from spectral imaging is considered. • We propose a new non-negative matrix factorization with two new penalties. • The first penalty is sparseness to choose the number of components from data. • Experimental results with real data demonstrate effectiveness of our method.

The baltic states' energy system

OpenAIRE

Nikitaravičius, Martynas

2006-01-01

THE BALTIC STATES’ ENERGY SYSTEM SUMMARY The goal of paper – the comparative analysis of Baltic states‘ (i.e. of Lithuania, Latvia, Estonia) energy systems in 1990-2004. The main causes that affected the development of Baltic states’ energetics are indicated in this work. By the method of statistical analysis, the comparative advantages of Baltic states‘ energetics are detected. Moreover, the main trends of further development of integration of Baltic states ‘ energetics into the energetics o...

Spectral Hounsfield units: a new radiological concept

International Nuclear Information System (INIS)

Hurrell, Michael Anthony; Butler, Anthony Philip Howard; Cook, Nicholas James; Butler, Philip Howard; Ronaldson, J.P.; Zainon, Rafidah

2012-01-01

Computed tomography (CT) uses radiographical density to depict different materials; although different elements have different absorption fingerprints across the range of diagnostic X-ray energies, this spectral absorption information is lost in conventional CT. The recent development of dual energy CT (DECT) allows extraction of this information to a useful but limited extent. However, the advent of new photon counting chips that have energy resolution capabilities has put multi-energy or spectral CT (SCT) on the clinical horizon. This paper uses a prototype SCT system to demonstrate how CT density measurements vary with kilovoltage. While radiologists learn about linear attenuation curves during radiology training, they do not usually need a detailed understanding of this phenomenon in their clinical practice. However SCT requires a paradigm shift in how radiologists think about CT density. Because radiologists are already familiar with the Hounsfield Unit (HU), it is proposed that a modified HU be used that includes the mean energy used to obtain the image, as a conceptual bridge between conventional CT and SCT. A suggested format would be: HU keV . (orig.)

State and Local Initiatives: Your Bridge to Renewable Energy and Energy Efficiency Resources (Brochure)

International Nuclear Information System (INIS)

Epstein, K.

2001-01-01

A brochure for local and state policymakers, informing them about the State and Local Initiatives team at the National Renewable Energy Laboratory. The brochure outlines the benefits of using renewables and energy efficiency, the benefits of using the State and Local Initiatives team as a liaison to the wealth of information at NREL, and some of the services and resources available

Virtual non-contrast CT using dual energy spectral CT: Feasibility of coronary artery calcium scoring

International Nuclear Information System (INIS)

Song, In Young; Yi, Jeong Geun; Park, Jeong Hee; Lee, Sung Mok; Lee, Kyung Soo; Chung, Myung Jin

2016-01-01

To evaluate the feasibility of coronary artery calcium scoring based on three virtual noncontrast-enhanced (VNC) images derived from single-source spectral dual-energy CT (DECT) as compared with true noncontrast-enhanced (TNC) images. This prospective study was conducted with the approval of our Institutional Review Board. Ninety-seven patients underwent noncontrast CT followed by contrast-enhanced chest CT using single-source spectral DECT. Iodine eliminated VNC images were reconstructed using two kinds of 2-material decomposition algorithms (material density iodine-water pair [MDW], material density iodine-calcium pair [MDC]) and a material suppressed algorithm (material suppressed iodine [MSI]). Two readers independently quantified calcium on VNC and TNC images. The Spearman correlation coefficient test and Bland-Altman method were used for statistical analyses. Coronary artery calcium scores from all three VNC images showed excellent correlation with those from the TNC images (Spearman's correlation coefficient [ρ] = 0.94, 0.88, and 0.89 for MDW, MDC, and MSI, respectively; p < 0.001 for all pairs). Measured coronary calcium volumes from VNC images also correlated well with those from TNC images (ρ = 0.92, 0.87, and 0.91 for MDW, MDC, and MSI, respectively; p < 0.001 for all pairs). Among the three VNC images, coronary calcium from MDW correlated best with that from TNC. The coronary artery calcium scores and volumes were significantly lower from the VNC images than from the TNC images (p < 0.001 for all pairs). The use of VNC images from contrast-enhanced CT using dual-energy material decomposition/suppression is feasible for coronary calcium scoring. The absolute value from VNC tends to be smaller than that from TNC

Virtual non-contrast CT using dual energy spectral CT: Feasibility of coronary artery calcium scoring

Energy Technology Data Exchange (ETDEWEB)

Song, In Young; Yi, Jeong Geun; Park, Jeong Hee [Dept. of Radiology, Konkuk University School of Medicine, Seoul (Korea, Republic of); Lee, Sung Mok; Lee, Kyung Soo; Chung, Myung Jin [Dept. of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

2016-06-15

To evaluate the feasibility of coronary artery calcium scoring based on three virtual noncontrast-enhanced (VNC) images derived from single-source spectral dual-energy CT (DECT) as compared with true noncontrast-enhanced (TNC) images. This prospective study was conducted with the approval of our Institutional Review Board. Ninety-seven patients underwent noncontrast CT followed by contrast-enhanced chest CT using single-source spectral DECT. Iodine eliminated VNC images were reconstructed using two kinds of 2-material decomposition algorithms (material density iodine-water pair [MDW], material density iodine-calcium pair [MDC]) and a material suppressed algorithm (material suppressed iodine [MSI]). Two readers independently quantified calcium on VNC and TNC images. The Spearman correlation coefficient test and Bland-Altman method were used for statistical analyses. Coronary artery calcium scores from all three VNC images showed excellent correlation with those from the TNC images (Spearman's correlation coefficient [ρ] = 0.94, 0.88, and 0.89 for MDW, MDC, and MSI, respectively; p < 0.001 for all pairs). Measured coronary calcium volumes from VNC images also correlated well with those from TNC images (ρ = 0.92, 0.87, and 0.91 for MDW, MDC, and MSI, respectively; p < 0.001 for all pairs). Among the three VNC images, coronary calcium from MDW correlated best with that from TNC. The coronary artery calcium scores and volumes were significantly lower from the VNC images than from the TNC images (p < 0.001 for all pairs). The use of VNC images from contrast-enhanced CT using dual-energy material decomposition/suppression is feasible for coronary calcium scoring. The absolute value from VNC tends to be smaller than that from TNC.

Forecast of the energy final consumption for Minas Gerais State

International Nuclear Information System (INIS)

Almeida, P.E.F. de; Bechtlufft, P.C.T.; Araujo, M.E.A.; Vasconcelos, E.C.; Las Casas, H.B. de; Monteiro, M.A.G.

1990-01-01

This paper is included among the activities of the Energy Planning of Minas Gerais State and presents a forecast of the energy final consumption for the State up to year 2010. Two Scenarios are presented involving brazilian economy's evolution, the State's demography and its sectors: residential, services, transportation, agriculture and cattle-breeding and industry. Finally, it shows two forecast on energy final consumption for Minas Gerais State. (author)

Effect of non-stationary accretion on spectral state transitions: An example of a persistent neutron star LMXB 4U1636–536

Science.gov (United States)

Zhang, Hui; Yu, Wen-Fei

2018-03-01

Observations of black hole and neutron star X-ray binaries show that the luminosity of the hard-to-soft state transition is usually higher than that of the soft-to-hard state transition, indicating additional parameters other than mass accretion rate are required to interpret spectral state transitions. It has been found in some individual black hole or neutron star soft X-ray transients that the luminosity corresponding to the hard-to-soft state transition is positively correlated with the peak luminosity of the following soft state. In this work, we report the discovery of the same correlation in the single persistent neutron star low mass X-ray binary (LMXB) 4U 1636–536 based on data from the All Sky Monitor (ASM) on board RXTE, the Gas Slit Camera (GSC) on board MAXI and the Burst Alert Telescope (BAT) on board Swift. We also found such a positive correlation holds in this persistent neutron star LMXB in a luminosity range spanning about a factor of four. Our results indicate that non-stationary accretion also plays an important role in driving X-ray spectral state transitions in persistent accreting systems with small accretion flares, which is much less dramatic compared with the bright outbursts seen in many Galactic LMXB transients.

Energy use in Minnesota state-owned facilities

Energy Technology Data Exchange (ETDEWEB)

Hirst, E; Eastes, C; Tyler, R

1981-08-01

This paper describes and analyzes the contents of a large data base containing infomation on monthly energy use of state-owned facilities in Minnesota are described and analyzed. The data base includes information on 42 community colleges, state universities, hospitals, prisons, and the St. Paul Capitol Complex. The data span a seven year period (1972 - 1978) and include about 3,500 observations. Several data base management issues are discussed. These include errors and their correction, development of simple and consistent definitions for key terms, and collection of information on key determinants of energy use at these facilities. Regression equations were developed to predict monthly heating fuel use and total energy use. These equations show that more than 60% of the variation in energy use per unit floorspace can be explained by a few variables.

Energy policy in the United States

Energy Technology Data Exchange (ETDEWEB)

McCormack, M

1978-06-01

Energy policy in the United States is examined with particular regard to the nuclear power industry. The advantages of nuclear power over conventional and other sources are presented and the vigorous expansion of research and development is advocated. Future energy supplies are discussed and the author stresses the necessity for continued research into breeder technology.

Spectral Learning for Supervised Topic Models.

Science.gov (United States)

Ren, Yong; Wang, Yining; Zhu, Jun

2018-03-01

Supervised topic models simultaneously model the latent topic structure of large collections of documents and a response variable associated with each document. Existing inference methods are based on variational approximation or Monte Carlo sampling, which often suffers from the local minimum defect. Spectral methods have been applied to learn unsupervised topic models, such as latent Dirichlet allocation (LDA), with provable guarantees. This paper investigates the possibility of applying spectral methods to recover the parameters of supervised LDA (sLDA). We first present a two-stage spectral method, which recovers the parameters of LDA followed by a power update method to recover the regression model parameters. Then, we further present a single-phase spectral algorithm to jointly recover the topic distribution matrix as well as the regression weights. Our spectral algorithms are provably correct and computationally efficient. We prove a sample complexity bound for each algorithm and subsequently derive a sufficient condition for the identifiability of sLDA. Thorough experiments on synthetic and real-world datasets verify the theory and demonstrate the practical effectiveness of the spectral algorithms. In fact, our results on a large-scale review rating dataset demonstrate that our single-phase spectral algorithm alone gets comparable or even better performance than state-of-the-art methods, while previous work on spectral methods has rarely reported such promising performance.

Hybrid Systems Based on Layered Silicate and Organic Dyes for Cascade Energy Transfer

Czech Academy of Sciences Publication Activity Database

Belušáková, S.; Lang, Kamil; Bujdák, J.

2015-01-01

Roč. 119, č. 38 (2015), s. 21784-21794 ISSN 1932-7447 Institutional support: RVO:61388980 Keywords : Cascade energy transfers * Multicomponent films * Resonance energy transfer * Spectral properties * Steady state fluorescence * Time-resolved fluorescence spectroscopy Subject RIV: CA - Inorganic Chemistry Impact factor: 4.509, year: 2015

q-Gamow states for intermediate energies

Energy Technology Data Exchange (ETDEWEB)

Plastino, A. [La Plata National University and Argentina' s National Research Council, (IFLP-CCT-CONICET)-C. C. 727, 1900 La Plata (Argentina); Rocca, M.C., E-mail: mariocarlosrocca@gmail.com [La Plata National University and Argentina' s National Research Council, (IFLP-CCT-CONICET)-C. C. 727, 1900 La Plata (Argentina); Ferri, G.L. [Fac. de C. Exactas, National University La Pampa, Peru y Uruguay, Santa Rosa, La Pampa (Argentina); Zamora, D.J. [La Plata National University and Argentina' s National Research Council, (IFLP-CCT-CONICET)-C. C. 727, 1900 La Plata (Argentina)

2016-11-15

In a recent paper Plastino and Rocca (2016) [18] we have demonstrated the possible existence of Tsallis' q-Gamow states. Now, accelerators' experimental evidence for Tsallis' distributions has been ascertained only at very high energies. Here, instead, we develop a different set of q-Gamow states for which the associated q-Breit–Wigner distribution could easily be found at intermediate energies, for which accelerators are available at many locations. In this context, it should be strongly emphasized Vignat and Plastino (2009) [2] that, empirically, one never exactly and unambiguously “detects” pure Gaussians, but rather q-Gaussians. A prediction is made via Eq. (3.4).

Statistical Analysis of Spectral Properties and Prosodic Parameters of Emotional Speech

Science.gov (United States)

Přibil, J.; Přibilová, A.

2009-01-01

The paper addresses reflection of microintonation and spectral properties in male and female acted emotional speech. Microintonation component of speech melody is analyzed regarding its spectral and statistical parameters. According to psychological research of emotional speech, different emotions are accompanied by different spectral noise. We control its amount by spectral flatness according to which the high frequency noise is mixed in voiced frames during cepstral speech synthesis. Our experiments are aimed at statistical analysis of cepstral coefficient values and ranges of spectral flatness in three emotions (joy, sadness, anger), and a neutral state for comparison. Calculated histograms of spectral flatness distribution are visually compared and modelled by Gamma probability distribution. Histograms of cepstral coefficient distribution are evaluated and compared using skewness and kurtosis. Achieved statistical results show good correlation comparing male and female voices for all emotional states portrayed by several Czech and Slovak professional actors.

State Transition and Flaring Activity of IGR J17464-3213/H1743-322 with INTEGRAL SPI

Science.gov (United States)

Joinet, A.; Jourdain, E.; Malzac, J.; Roques, J. P.; Schönfelder, V.; Ubertini, P.; Capitanio, F.

2005-08-01

IGR J17464-3213, already known as the HEAO 1 transient source H1743-322, has been detected during a state transition by INTEGRAL SPI. We describe the spectral evolution and flaring activity of IGR J17464-3213/H1743-322 from 2003 March 21 to 2003 April 22. During the first part, the source followed a continuous spectral softening, with the peak of the spectral energy distribution shifting from 100 keV down to ~a few keV. However, the thermal disk and the hard X-ray components had a similar intensity, indicating that the source was in an intermediate state throughout our observations and evolving toward the soft state. In the second part of our observations, the RXTE ASM and INTEGRAL SPI light curves showed a strong flaring activity. Two flare events lasting about 1 day each have been detected with SPI and are probably due to instabilities in the accretion disk associated with the state transition. During these flares, the low (1.5-12 keV) and high (20-200 keV) energy fluxes monitored with the RXTE ASM and INTEGRAL SPI are correlated, and the spectral shape (above 20 keV) remains unchanged while the luminosity increases by a factor greater than 2.

Correlative Spectral Analysis of Gamma-Ray Bursts using Swift-BAT and GLAST-GBM

International Nuclear Information System (INIS)

Stamatikos, Michael; Sakamoto, Taka; Band, David L.

2008-01-01

We discuss the preliminary results of spectral analysis simulations involving anticipated correlated multi-wavelength observations of gamma-ray bursts (GRBs) using Swift's Burst Alert Telescope (BAT) and the Gamma-Ray Large Area Space Telescope's (GLAST) Burst Monitor (GLAST-GBM), resulting in joint spectral fits, including characteristic photon energy (E peak ) values, for a conservative annual estimate of ∼30 GRBs. The addition of BAT's spectral response will (i) complement in-orbit calibration efforts of GBM's detector response matrices, (ii) augment GLAST's low energy sensitivity by increasing the ∼20-100 keV effective area, (iii) facilitate ground-based follow-up efforts of GLAST GRBs by increasing GBM's source localization precision, and (iv) help identify a subset of non-triggered GRBs discovered via off-line GBM data analysis. Such multi-wavelength correlative analyses, which have been demonstrated by successful joint-spectral fits of Swift-BAT GRBs with other higher energy detectors such as Konus-WIND and Suzaku-WAM, would enable the study of broad-band spectral and temporal evolution of prompt GRB emission over three energy decades, thus potentially increasing science return without placing additional demands upon mission resources throughout their contemporaneous orbital tenure over the next decade.

Correlative Spectral Analysis of Gamma-Ray Bursts using Swift-BAT and GLAST-GBM

International Nuclear Information System (INIS)

Stamatikos, Michael; Sakamoto, Takanori; Band, David L.

2008-01-01

We discuss the preliminary results of spectral analysis simulations involving anticipated correlated multi-wavelength observations of gamma-ray bursts (GRBs) using Swift's Burst Alert Telescope (BAT) and the Gamma-Ray Large Area Space Telescope's (GLAST) Burst Monitor (GLAST-GBM), resulting in joint spectral fits, including characteristic photon energy (E peak ) values, for a conservative annual estimate of ∼30 GRBs. The addition of BAT/s spectral response will (i) complement in-orbit calibration efforts of GBM's detector response matrices, (ii) augment GLAST's low energy sensitivity by increasing the ∼20-100 keV effective area, (iii) facilitate ground-based follow-up efforts of GLAST GRBs by increasing GBM's source localization precision, and (iv) help identify a subset of non-triggered GRBs discovered via off-line GBM data analysis. Such multi-wavelength correlative analyses, which have been demonstrated by successful joint-spectral fits of Swift-BAT GRBs with other higher energy detectors such as Konus-WIND and Suzaku-WAM, would enable the study of broad-band spectral and temporal evolution of prompt GRB emission over three energy decades, thus potentially increasing science return without placing additional demands upon mission resources throughout their contemporaneous orbital tenure over the next decade

Rydberg energies using excited state density functional theory

International Nuclear Information System (INIS)

Cheng, C.-L.; Wu Qin; Van Voorhis, Troy

2008-01-01

We utilize excited state density functional theory (eDFT) to study Rydberg states in atoms. We show both analytically and numerically that semilocal functionals can give quite reasonable Rydberg energies from eDFT, even in cases where time dependent density functional theory (TDDFT) fails catastrophically. We trace these findings to the fact that in eDFT the Kohn-Sham potential for each state is computed using the appropriate excited state density. Unlike the ground state potential, which typically falls off exponentially, the sequence of excited state potentials has a component that falls off polynomially with distance, leading to a Rydberg-type series. We also address the rigorous basis of eDFT for these systems. Perdew and Levy have shown using the constrained search formalism that every stationary density corresponds, in principle, to an exact stationary state of the full many-body Hamiltonian. In the present context, this means that the excited state DFT solutions are rigorous as long as they deliver the minimum noninteracting kinetic energy for the given density. We use optimized effective potential techniques to show that, in some cases, the eDFT Rydberg solutions appear to deliver the minimum kinetic energy because the associated density is not pure state v-representable. We thus find that eDFT plays a complementary role to constrained DFT: The former works only if the excited state density is not the ground state of some potential while the latter applies only when the density is a ground state density.

Spectral functions of hadrons in lattice QCD

International Nuclear Information System (INIS)

Nakahara, Y.; Asakawa, M.; Hatsuda, T.

2000-01-01

Using the maximum entropy method, spectral functions of the pseudo-scalar and vector mesons are extracted from lattice Monte Carlo data of the imaginary time Green's functions. The resonance and continuum structures as well as the ground state peaks are successfully obtained. Error analysis of the resultant spectral functions is also given on the basis of the Bayes probability theory. (author)

Energy balance from Parana State - 1980-1992

International Nuclear Information System (INIS)

1993-01-01

The energy flows of primary and secondary energy sources since the production to the end consumption in the main sectors of Parana State economy during 1980 to 1992, are presented. The supply and demand, consumption and production of energy sources are shown. Some information about resources and reserves are also cited. (C.G.C.)

Swift Observations of Mrk 421 in Selected Epochs. II. An Extreme Spectral Flux Variability in 2009–2012

Science.gov (United States)

Kapanadze, B.; Vercellone, S.; Romano, P.; Hughes, P.; Aller, M.; Aller, H.; Kharshiladze, O.; Tabagari, L.

2018-05-01

We present the results from a detailed spectral and timing study of Mrk 421 based on the rich archival Swift data obtained during 2009–2012. Best fits of the 0.3–10 keV spectra were mostly obtained using the log-parabolic model showing the relatively low spectral curvature that is expected in the case of efficient stochastic acceleration of particles. The position of the synchrotron spectral energy density peak E p of 173 spectra is found at energies higher than 2 keV. The photon index at 1 keV exhibited a very broad range of values a = 1.51–3.02, and very hard spectra with a historical state and that corresponding to a rate higher than 100 cts s‑1. Moreover, 113 instances of intraday variability were revealed, exhibiting shortest flux-doubling/halving times of about 1.2 hr, as well as brightenings by 7%–24% in 180–720 s and declines by 68%–22% in 180–900 s. The X-ray and very high-energy fluxes generally showed a correlated variability, although one incidence of a more complicated variability was also detected, indicating that the multifrequency emission of Mrk 421 could not be generated in a single zone.

Spectral properties of the accretion discs around rotating black holes

Indian Academy of Sciences (India)

Samir Mandal

2018-02-10

Feb 10, 2018 ... spectral characteristics due to a free-fall flow and a transonic flow. We notice significant ..... (iii) pressure balance: W+ + + u2. + = W− + − u2. − ... this hot and dense flow controls the high energy spectral characteristic of the ...

Dual-energy approach to contrast-enhanced mammography using the balanced filter method: spectral optimization and preliminary phantom measurement.

Science.gov (United States)

Saito, Masatoshi

2007-11-01

Dual-energy contrast agent-enhanced mammography is a technique of demonstrating breast cancers obscured by a cluttered background resulting from the contrast between soft tissues in the breast. The technique has usually been implemented by exploiting two exposures to different x-ray tube voltages. In this article, another dual-energy approach using the balanced filter method without switching the tube voltages is described. For the spectral optimization of dual-energy mammography using the balanced filters, we applied a theoretical framework reported by Lemacks et al. [Med. Phys. 29, 1739-1751 (2002)] to calculate the signal-to-noise ratio (SNR) in an iodinated contrast agent subtraction image. This permits the selection of beam parameters such as tube voltage and balanced filter material, and the optimization of the latter's thickness with respect to some critical quantity-in this case, mean glandular dose. For an imaging system with a 0.1 mm thick CsI:T1 scintillator, we predict that the optimal tube voltage would be 45 kVp for a tungsten anode using zirconium, iodine, and neodymium balanced filters. A mean glandular dose of 1.0 mGy is required to obtain an SNR of 5 in order to detect 1.0 mg/cm2 iodine in the resulting clutter-free image of a 5 cm thick breast composed of 50% adipose and 50% glandular tissue. In addition to spectral optimization, we carried out phantom measurements to demonstrate the present dual-energy approach for obtaining a clutter-free image, which preferentially shows iodine, of a breast phantom comprising three major components-acrylic spheres, olive oil, and an iodinated contrast agent. The detection of iodine details on the cluttered background originating from the contrast between acrylic spheres and olive oil is analogous to the task of distinguishing contrast agents in a mixture of glandular and adipose tissues.

Dual-energy approach to contrast-enhanced mammography using the balanced filter method: Spectral optimization and preliminary phantom measurement

International Nuclear Information System (INIS)

Saito, Masatoshi

2007-01-01

Dual-energy contrast agent-enhanced mammography is a technique of demonstrating breast cancers obscured by a cluttered background resulting from the contrast between soft tissues in the breast. The technique has usually been implemented by exploiting two exposures to different x-ray tube voltages. In this article, another dual-energy approach using the balanced filter method without switching the tube voltages is described. For the spectral optimization of dual-energy mammography using the balanced filters, we applied a theoretical framework reported by Lemacks et al. [Med. Phys. 29, 1739-1751 (2002)] to calculate the signal-to-noise ratio (SNR) in an iodinated contrast agent subtraction image. This permits the selection of beam parameters such as tube voltage and balanced filter material, and the optimization of the latter's thickness with respect to some critical quantity--in this case, mean glandular dose. For an imaging system with a 0.1 mm thick CsI:Tl scintillator, we predict that the optimal tube voltage would be 45 kVp for a tungsten anode using zirconium, iodine, and neodymium balanced filters. A mean glandular dose of 1.0 mGy is required to obtain an SNR of 5 in order to detect 1.0 mg/cm 2 iodine in the resulting clutter-free image of a 5 cm thick breast composed of 50% adipose and 50% glandular tissue. In addition to spectral optimization, we carried out phantom measurements to demonstrate the present dual-energy approach for obtaining a clutter-free image, which preferentially shows iodine, of a breast phantom comprising three major components - acrylic spheres, olive oil, and an iodinated contrast agent. The detection of iodine details on the cluttered background originating from the contrast between acrylic spheres and olive oil is analogous to the task of distinguishing contrast agents in a mixture of glandular and adipose tissues

The Energy Puzzle Between the United States and China

Science.gov (United States)

2013-03-01

securing China’s status as a great power.2 As of 2011, China is the second largest consumer of natural resources (oil, liquefied petroleum gas ( LPG ...pursuit of natural resources, (oil, natural gas , coal or renewable energy sources) is reshaping the world’s energy security. The United States is...pursuit of natural resources, (oil, natural gas , coal or renewable energy sources) is reshaping the world’s energy security. The United States is

Energy flow in angularly dispersive optical systems

International Nuclear Information System (INIS)

Ware, M.; Dibble, W. E.; Glasgow, S. A.; Peatross, J.

2001-01-01

Light-pulse propagation in angularly dispersive systems is explored in the context of a center-of-mass definition of energy arrival time. In this context the time of travel is given by a superposition of group delays weighted by the spectral content of the pulse. With this description the time of travel from one point to the next for a pulse is found to be completely determined by the spectral content, independent of the state of chirp. The effect of sensor orientation on arrival time is also considered. [copyright] 2001 Optical Society of America

Heat-Mirror Spectral Profile Optimization for TSC Hybrid Solar Conversion

Science.gov (United States)

Soule, D. E.; Wood, S. E.

1986-09-01

The efficiencies for total solar cogeneration (TSC) can be optimized by tailoring the transparent heat-mirror (HM) beam splitter spectral profile shape. The entire output is cogenerated by photovoltaic/photothermal conversions into three energy forms: electricity (PV) 18V d.c./module, high-temperature heat (HT) 400°C, and low-temperature heat (LT) 70°C. The emphasis is to maximize the high-quality energy sum PV + HT, while maintaining PV at a high level. A generalized 5-parameter double Fermi model for the HM spectral profile is investigated allowing for a wide parametric range and profile asymmetry. The projected optimized TSC conversion efficiencies are: PV = 14.3%, HT = 43.5%, and LT = 42.2% with a high-quality energy sum of PV + HT = 57.8%. The approach to this optimum HM spectral profile by experimental HM films such as ITO are discussed.

Spectral decomposition of tent maps using symmetry considerations

International Nuclear Information System (INIS)

Ordonez, G.E.; Driebe, D.J.

1996-01-01

The spectral decompostion of the Frobenius-Perron operator of maps composed of many tents is determined from symmetry considerations. The eigenstates involve Euler as well as Bernoulli polynomials. The authors have introduced some new techniques, based on symmetry considerations, enabling the construction of spectral decompositions in a much simpler way than previous construction algorithms, Here we utilize these techniques to construct the spectral decomposition for one- dimensional maps of the unit interval composed of many tents. The construction uses the knowledge of the spectral decomposition of the r-adic map, which involves Bernoulli polynomials and their duals. It will be seen that the spectral decomposition of the tent maps involves both Bernoulli polynomials and Euler polynomials along with the appropriate dual states

Mitigation of cross-beam energy transfer: Implication of two-state focal zooming on OMEGA

International Nuclear Information System (INIS)

Froula, D. H.; Kessler, T. J.; Igumenshchev, I. V.; Betti, R.; Goncharov, V. N.; Huang, H.; Hu, S. X.; Hill, E.; Kelly, J. H.; Meyerhofer, D. D.; Shvydky, A.; Zuegel, J. D.

2013-01-01

Cross-beam energy transfer (CBET) during OMEGA low-adiabat cryogenic experiments reduces the hydrodynamic efficiency by ∼35%, which lowers the calculated one-dimensional (1-D) yield by a factor of 7. CBET can be mitigated by reducing the diameter of the laser beams relative to the target diameter. Reducing the diameter of the laser beams by 30%, after a sufficient conduction zone has been generated (two-state zooming), is predicted to maintain low-mode uniformity while recovering 90% of the kinetic energy lost to CBET. A radially varying phase plate is proposed to implement two-state zooming on OMEGA. A beam propagating through the central half-diameter of the phase plate will produce a large spot, while a beam propagating through the outer annular region of the phase plate will produce a narrower spot. To generate the required two-state near-field laser-beam profile, a picket driver with smoothing by spectral dispersion (SSD) would pass through an apodizer, forming a beam of half the standard diameter. A second main-pulse driver would co-propagate without SSD through its own apodizer, forming a full-diameter annular beam. Hydrodynamic simulations, using the designed laser spots produced by the proposed zooming scheme on OMEGA, show that implementing zooming will increase the implosion velocity by 25% resulting in a 4.5× increase in the 1-D neutron yield. Demonstrating zooming on OMEGA would validate a viable direct-drive CBET mitigation scheme and help establish a pathway to hydrodynamically equivalent direct-drive–ignition implosions by increasing the ablation pressure (1.6×), which will allow for more stable implosions at ignition-relevant velocities

A hybrid spatial-spectral denoising method for infrared hyperspectral images using 2DPCA

Science.gov (United States)

Huang, Jun; Ma, Yong; Mei, Xiaoguang; Fan, Fan

2016-11-01

The traditional noise reduction methods for 3-D infrared hyperspectral images typically operate independently in either the spatial or spectral domain, and such methods overlook the relationship between the two domains. To address this issue, we propose a hybrid spatial-spectral method in this paper to link both domains. First, principal component analysis and bivariate wavelet shrinkage are performed in the 2-D spatial domain. Second, 2-D principal component analysis transformation is conducted in the 1-D spectral domain to separate the basic components from detail ones. The energy distribution of noise is unaffected by orthogonal transformation; therefore, the signal-to-noise ratio of each component is used as a criterion to determine whether a component should be protected from over-denoising or denoised with certain 1-D denoising methods. This study implements the 1-D wavelet shrinking threshold method based on Stein's unbiased risk estimator, and the quantitative results on publicly available datasets demonstrate that our method can improve denoising performance more effectively than other state-of-the-art methods can.

NREL's Clean Energy Policy Analyses Project. 2009 U.S. State Clean Energy Data Book

Energy Technology Data Exchange (ETDEWEB)

Gelman, Racel [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hummon, Marissa [National Renewable Energy Lab. (NREL), Golden, CO (United States); McLaren, Joyce [National Renewable Energy Lab. (NREL), Golden, CO (United States); Doris, Elizabeth [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2009-10-01

This data book provides a summary of the status of state-level energy efficiency and renewable energy (taken together as clean energy) developments and supporting policy implementation. It is intended as a reference book for those interested in the progress of the states and regions toward a clean energy economy. Although some national-scale data are given in the initial section, the data are mostly aggregated by states and region, and no data on federal- or utility-level policies are presented here.

Bulgarian geothermal energy resources - state and perspective

Energy Technology Data Exchange (ETDEWEB)

Gramatikov, P S [Faculty of Natural Sciences and Mathematics, Dept. of Physical Engineering, South West Univ. ` Neofit Rilsky` , Blagoevgrad (Bulgaria)

1997-12-01

As special attention is paid to geothermal energy because the geothermal sources are distributed all over the territory of Bulgaria. Governmental incentives for initiating national action programs for energy efficiency, new renewable sources and the environment as well as educational activities are particularly important. The energy sector, as any other sector of the national economy, is currently undergoing considerable changes on its way to market relations, primarily connected to determining the role of the state as well as the form of ownership. The state energy policy is based on a long - term energy strategy complying with the natural conditions of the country, the expected macro - economic development, the geopolitical situation and regional development of energy cooperation with neighboring and closely situated countries. Limited reserves of fossil fuels, increased local and global environmental risks and recent technological achievements have straightened the global importance of renewable sources of thermal and electric energy. This is even more relevant for Bulgaria with small fossil fuel reserves (lignite) to be nearly exhausted and the environment notably polluted. Concerning local renewable sources of thermal energy and electricity, it is necessary to re-estimate their strategic role, to complete the input data for the resources, also to establish national programs supported by research and educational activities and international cooperation. (orig./AKF)

Contrast Enhanced Spectral Mammography: A Review.

Science.gov (United States)

Patel, Bhavika K; Lobbes, M B I; Lewin, John

2018-02-01

Contrast-enhanced spectral mammography (CESM) provides low-energy 2D mammographic images comparable to standard digital mammography and a post-contrast recombined image to assess tumor neovascularity similar to magnetic resonance imaging (MRI). The utilization of CESM in the United States is currently low but could increase rapidly given many potential indications for clinical use. This article discusses historical background and literature review of indications and diagnostic accuracy of CESM to date. CESM is a growing technique for breast cancer detection and diagnosis that has levels of sensitivity and specificity on par with contrast-enhanced breast MRI. Because of its similar performance and ease of implementation, CESM is being adopted for multiple indications previously reserved for MRI, such as problem-solving, disease extent in newly diagnosed patients, and evaluating the treatment response of neoadjuvant chemotherapy. Copyright © 2018 Elsevier Inc. All rights reserved.

Spectral Slope as an Indicator of Pasture Quality

Directory of Open Access Journals (Sweden)

Rachel Lugassi

2014-12-01

Full Text Available In this study, we develop a spectral method for assessment of pasture quality based only on the spectral information obtained with a small number of wavelengths. First, differences in spectral behavior were identified across the near infrared–shortwave infrared spectral range that were indicative of changes in chemical properties. Then, slopes across different spectral ranges were calculated and correlated with the changes in crude protein (CP, neutral detergent fiber (NDF and metabolic energy concentration (MEC. Finally, partial least squares (PLS regression analysis was applied to identify the optimal spectral ranges for accurate assessment of CP, NDF and MEC. Six spectral domains and a set of slope criteria for real-time evaluation of pasture quality were suggested. The evaluation of three level categories (low, medium, high for these three parameters showed a success rate of: 73%–96% for CP, 72%–87% for NDF and 60%–85% for MEC. Moreover, only one spectral range, 1748–1764 nm, was needed to provide a good estimation of CP, NDF and MEC. Importantly, five of the six selected spectral regions were not affected by water absorbance. With some modifications, this rationale can be applied to further analyses of pasture quality from airborne sensors.

Detection of X-ray spectral state transitions in mini-outbursts of black hole transient GRS 1739-278

Science.gov (United States)

Yan, Zhen; Yu, Wenfei

2017-10-01

We report the detection of the state transitions and hysteresis effect in the two mini-outbursts of the black hole (BH) transient GRS 1739-278 following its 2014 major outburst. The X-ray spectral evolutions in these two mini-outbursts are similar to the major outburst in spite of their peak luminosities and the outburst durations are one order of magnitude lower. We found L_hard{-to-soft} and Lpeak,soft of the mini-outbursts also follow the correlation previously found in other X-ray binaries. L_hard{-to-soft} of the mini-outbursts is still higher than that of the persistent BH binary Cyg X-1, which supports that there is a link between the maximum luminosity a source can reach in the hard state and the corresponding non-stationary accretion represented by substantial rate of change in the mass accretion rate during flares/outbursts. The detected luminosity range of these two mini-outbursts is roughly in 3.5 × 10-5 to 0.015 (D/7.5 kpc)2(M/8M⊙) LEdd. The X-ray spectra of other BH transients at such low luminosities are usually dominated by a power-law component, and an anti-correlation is observed between the photon index and the X-ray luminosity below 1 per cent LEdd. So, the detection of X-ray spectral state transitions indicates that the accretion flow evolution in these two mini-outbursts of GRS 1739-278 are different from other BH systems at such low-luminosity regime.

A framelet-based iterative maximum-likelihood reconstruction algorithm for spectral CT

Science.gov (United States)

Wang, Yingmei; Wang, Ge; Mao, Shuwei; Cong, Wenxiang; Ji, Zhilong; Cai, Jian-Feng; Ye, Yangbo

2016-11-01

Standard computed tomography (CT) cannot reproduce spectral information of an object. Hardware solutions include dual-energy CT which scans the object twice in different x-ray energy levels, and energy-discriminative detectors which can separate lower and higher energy levels from a single x-ray scan. In this paper, we propose a software solution and give an iterative algorithm that reconstructs an image with spectral information from just one scan with a standard energy-integrating detector. The spectral information obtained can be used to produce color CT images, spectral curves of the attenuation coefficient μ (r,E) at points inside the object, and photoelectric images, which are all valuable imaging tools in cancerous diagnosis. Our software solution requires no change on hardware of a CT machine. With the Shepp-Logan phantom, we have found that although the photoelectric and Compton components were not perfectly reconstructed, their composite effect was very accurately reconstructed as compared to the ground truth and the dual-energy CT counterpart. This means that our proposed method has an intrinsic benefit in beam hardening correction and metal artifact reduction. The algorithm is based on a nonlinear polychromatic acquisition model for x-ray CT. The key technique is a sparse representation of iterations in a framelet system. Convergence of the algorithm is studied. This is believed to be the first application of framelet imaging tools to a nonlinear inverse problem.

Renewable energy rebound effect?: Estimating the impact of state renewable energy financial incentives on residential electricity consumption

Science.gov (United States)

Stephenson, Beth A.

Climate change is a well-documented phenomenon. If left unchecked greenhouse gas emissions will continue global surface warming, likely leading to severe and irreversible impacts. Generating renewable energy has become an increasingly salient topic in energy policy as it may mitigate the impact of climate change. State renewable energy financial incentives have been in place since the mid-1970s in some states and over 40 states have adopted one or more incentives at some point since then. Using multivariate linear and fixed effects regression for the years 2002 through 2012, I estimate the relationship between state renewable energy financial incentives and residential electricity consumption, along with the associated policy implications. My hypothesis is that a renewable energy rebound effect is present; therefore, states with renewable energy financial incentives have a higher rate of residential electricity consumption. I find a renewable energy rebound effect is present in varying degrees for each model, but the results do not definitively indicate how particular incentives influence consumer behavior. States should use caution when adopting and keeping renewable energy financial incentives as this may increase consumption in the short-term. The long-term impact is unclear, making it worthwhile for policymakers to continue studying the potential for renewable energy financial incentives to alter consumer behavior.

Energy in a state of shock

International Nuclear Information System (INIS)

Chevalier, Jean-Marie; Pastre, Olivier; Mestrallet, Gerard; Jouzel, Jean; Geoffron, Patrice; Boniface, Pascal; Lorenzi, Jean-Herve; Bornard, Pierre; Levitte, Jean-David; Jacquillat, Bertrand; Gallois, Louis; Gaymard, Clara; Perthuis, Christian de; Schwarz, Virginie; Lechevin, Bruno; Baud, Olivier; Moulin, Julien

2015-01-01

The news concerning energy are in a continuous state of shock: falling oil prices, shale gas revolution in the US, energy transition policies, gas crisis between Russia and Ukraine, etc. The energy world is also facing major challenges, notably the climatic change. In its first part, this book presents in a highly pedagogical way, the key world energy data and their main economic, environmental and political related issues. Issues and perspectives are described for each energy system, with a particular interest in the European energy system and the future 'Energy Union' that is intended to secure the european energy supply. In the second part, the authors give the floor to twelve experts who raise alarm about the specific energy issue before the forthcoming COP 21 conference on climatic change in Paris: overview of the climatic change issue (by Jean Jouzel), energy transition policies in Europe (by Patrice Geoffron), the negotiations inside a hypothetical 'international community' (by Pascal Boniface), energy transition and financing, the green growth, giving a price to carbon, energy policy and democracy, etc

Spectral correlations in Anderson insulating wires

Science.gov (United States)

Marinho, M.; Micklitz, T.

2018-01-01

We calculate the spectral level-level correlation function of Anderson insulating wires for all three Wigner-Dyson classes. A measurement of its Fourier transform, the spectral form factor, is within reach of state-of-the-art cold atom quantum quench experiments, and we find good agreement with recent numerical simulations of the latter. Our derivation builds on a representation of the level-level correlation function in terms of a local generating function which may prove useful in other contexts.

Selection of side-chain carbons in a high-molecular-weight, hydrophobic peptide using solid-state spectral editing methods

International Nuclear Information System (INIS)

Kumashiro, Kristin K.; Niemczura, Walter P.; Kim, Minna S.; Sandberg, Lawrence B.

2000-01-01

Solid-state spectral editing techniques have been used by others to simplify 13 C CPMAS spectra of small organic molecules, synthetic organic polymers, and coals. One approach utilizes experiments such as cross-polarization-with-polarization-inversion and cross-polarization-with-depolarization to generate subspectra. This work shows that this particular methodology is also applicable to natural-abundance 13 C CPMAS NMR studies of high-molecular-weight biopolymers. The editing experiments are demonstrated first with model peptides and then with α-elastin, a high-molecular-weight peptidyl preparation obtained from the elastic fibers in mammalian tissue. The latter has a predominance of small, nonpolar residues, which is evident in the crowded aliphatic region of typical 13 C CPMAS spectra. Spectral editing is particularly useful for simplifying the aliphatic region of the NMR spectrum of this elastin preparation

Multi-state lasing in self-assembled ring-shaped green fluorescent protein microcavities

Energy Technology Data Exchange (ETDEWEB)

Dietrich, Christof P., E-mail: cpd3@st-andrews.ac.uk; Höfling, Sven; Gather, Malte C., E-mail: mcg6@st-andrews.ac.uk [SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS (United Kingdom)

2014-12-08

We demonstrate highly efficient lasing from multiple photonic states in microcavities filled with self-assembled rings of recombinant enhanced green fluorescent protein (eGFP) in its solid state form. The lasing regime is achieved at very low excitation energies of 13 nJ and occurs from cavity modes dispersed in both energy and momentum. We attribute the momentum distribution to very efficient scattering of incident light at the surface of the eGFP rings. The distribution of lasing states in energy is induced by the large spectral width of the gain spectrum of recombinant eGFP (FWHM ≅ 25 nm)

X-Ray Spectral Analysis of the Steady States of GRS1915+105

Science.gov (United States)

Peris, Charith S.; Remillard, Ronald A.; Steiner, James F.; Vrtilek, Saeqa D.; Varnière, Peggy; Rodriguez, Jerome; Pooley, Guy

2016-05-01

We report on the X-ray spectral behavior within the steady states of GRS1915+105. Our work is based on the full data set of the source obtained using the Proportional Counter Array (PCA) on the Rossi X-ray Timing Explorer (RXTE) and 15 GHz radio data obtained using the Ryle Telescope. The steady observations within the X-ray data set naturally separated into two regions in the color-color diagram and we refer to these regions as steady-soft and steady-hard. GRS1915+105 displays significant curvature in the coronal component in both the soft and hard data within the RXTE/PCA bandpass. A majority of the steady-soft observations displays a roughly constant inner disk radius ({R}{{in}}), while the steady-hard observations display an evolving disk truncation which is correlated to the mass accretion rate through the disk. The disk flux and coronal flux are strongly correlated in steady-hard observations and very weakly correlated in the steady-soft observations. Within the steady-hard observations, we observe two particular circumstances when there are correlations between the coronal X-ray flux and the radio flux with log slopes η ˜ 0.68+/- 0.35 and η ˜ 1.12+/- 0.13. They are consistent with the upper and lower tracks of Gallo et al. (2012), respectively. A comparison of the model parameters to the state definitions shows that almost all of the steady-soft observations match the criteria of either a thermal or steep power-law state, while a large portion of the steady-hard observations match the hard-state criteria when the disk fraction constraint is neglected.

The Chandra Source Catalog: Spectral Properties

Science.gov (United States)

Doe, Stephen; Siemiginowska, Aneta L.; Refsdal, Brian L.; Evans, Ian N.; Anderson, Craig S.; Bonaventura, Nina R.; Chen, Judy C.; Davis, John E.; Evans, Janet D.; Fabbiano, Giuseppina; Galle, Elizabeth C.; Gibbs, Danny G., II; Glotfelty, Kenny J.; Grier, John D.; Hain, Roger; Hall, Diane M.; Harbo, Peter N.; He, Xiang Qun (Helen); Houck, John C.; Karovska, Margarita; Kashyap, Vinay L.; Lauer, Jennifer; McCollough, Michael L.; McDowell, Jonathan C.; Miller, Joseph B.; Mitschang, Arik W.; Morgan, Douglas L.; Mossman, Amy E.; Nichols, Joy S.; Nowak, Michael A.; Plummer, David A.; Primini, Francis A.; Rots, Arnold H.; Sundheim, Beth A.; Tibbetts, Michael S.; van Stone, David W.; Winkelman, Sherry L.; Zografou, Panagoula

2009-09-01

The first release of the Chandra Source Catalog (CSC) contains all sources identified from eight years' worth of publicly accessible observations. The vast majority of these sources have been observed with the ACIS detector and have spectral information in 0.5-7 keV energy range. Here we describe the methods used to automatically derive spectral properties for each source detected by the standard processing pipeline and included in the final CSC. Hardness ratios were calculated for each source between pairs of energy bands (soft, medium and hard) using the Bayesian algorithm (BEHR, Park et al. 2006). The sources with high signal to noise ratio (exceeding 150 net counts) were fit in Sherpa (the modeling and fitting application from the Chandra Interactive Analysis of Observations package, developed by the Chandra X-ray Center; see Freeman et al. 2001). Two models were fit to each source: an absorbed power law and a blackbody emission. The fitted parameter values for the power-law and blackbody models were included in the catalog with the calculated flux for each model. The CSC also provides the source energy flux computed from the normalizations of predefined power-law and black-body models needed to match the observed net X-ray counts. In addition, we provide access to data products for each source: a file with source spectrum, the background spectrum, and the spectral response of the detector. This work is supported by NASA contract NAS8-03060 (CXC).

State of the energy in Lebanon

International Nuclear Information System (INIS)

Chehab, Said; Matar Toni

1998-01-01

The article describes the state of the energy in Lebanon. In 1996, Lebanon consumed 4647 Ktoe as a primary energy. 97% of this energy is imported mainly polluting oil products: 1623 Ktons fuel-oil, 1379 Ktons gasoline, 930 Ktons diesel, 200 Ktons coal, 124 Ktons LPG, 107 Ktons jet-fuel/Kerosene, 109 Ktons Asphaltic products. The remaining 3% of the energy consumption is renewable energy. As for production, the state owns two refineries which are not used anymore. The year 2000 plan includes an expansion project for the Tripoli refinery and an alternative plan for the Zahrani refinery. These refineries require a total investment in order to reach a production capacity of 50000 barrels a day. The article is a description of the pollution type sources and location in Lebanon. The combustion of the total energy produces yearly more than 15 Ktons of dust, 85 Ktons of SO 2 , 40 Ktons of NOX and 3500 Ktons of CO 2 . Another risk of pollution is due to spilling oil along the Lebanese coast which represents a potential oil spill hazard, with a serious impact on marine and coastal ecosystem. The paper presents also a proposed management schemes of energy policy , control and monitoring options. In addition to the energy balance in 93/94; the consumption of oil products in 93/94/96; oil products importations in 93/96; electricity consumption in 96; ventilation of thermal and hydraulic electricity production in 95/96; estimated inventory of emissions of selected pollutants to air in Lebanon in 93 and 2010; maximum permissible air pollutants in Lebanon; storage capacity of major petroleum importers

Energy balance of the Parana State - 1980-1994

International Nuclear Information System (INIS)

1995-01-01

This document presents the energetic balance of Parana State - 1980/1994, including the energy fluxes from primary and secondary energy sources in the main sectors of Parana economy. It informs consumption, production and energy external dependence. 26 figs., 88 tabs

Diagnosing x-ray power and energy of tungsten wire array z-pinch with a flat spectral response x-ray diode

International Nuclear Information System (INIS)

Wang, Kun-lun; Ren, Xiao-dong; Huang, Xian-bin; Zhang, Si-qun; Zhou, Shao-tong; Dan, Jia-kun; Li, Jing; Xu, Qiang; Ouyang, Kai; Cai, Hong-chun; Wei, Bing; Ji, Ce; Feng, Shu-ping; Wang, Meng; Xie, Wei-ping; Deng, Jian-jun

2015-01-01

Fast z-pinch is a very efficient way of converting electromagnetic energy to radiation. With an 8-10 MA current on primary test stand facility, about 1 MJ electromagnetic energy is delivered to vacuum chamber, which heats z-pinch plasma to radiate soft x-ray. To develop a pulsed high power x-ray source, we studied the applicability of diagnosing x-ray power from tungsten wire array z-pinch with a flat spectral response x-ray diode (FSR-XRD). The detector was originally developed to diagnose radiation of a hohlraum in SG-III prototype laser facility. It utilized a gold cathode XRD and a specially configured compound gold filter to yield a nearly flat spectral response in photon energy range of 0.1-4 keV. In practice, it was critical to avoid surface contamination of gold cathode. It is illustrated that an exposure of an XRD to multiple shots caused a significant change of response. Thus, in diagnosing x-ray power and energy, we used each XRD in only one shot after calibration. In a shot serial, output of FSR-XRD was compared with output of a nickel bolometer. In these shots, the outputs agreed with each other within their uncertainties which were about 12% for FSR-XRD and about 15% for bolometer. Moreover, the ratios between the FSR-XRD and the bolometer among different shots were explored. In 8 shots, the standard deviation of the ratio was 6%. It is comparable to XRD response change of 7%

Electric dipole moments of He atoms excited to the 1s5l (l  ⩾ 2) states by He+-ion impact at intermediate energies

International Nuclear Information System (INIS)

Baszanowska, E; Drozdowski, R; Kamiński, P; Von Oppen, G

2014-01-01

The post-collisional 1s5l (l ⩾ 2) states of He atoms after He + -ion impact (10 keV–28 keV) have been investigated using anticrossing spectroscopy. In particular, the intensity of the spectral line λ(1s5l 3 D-1s2p 3 P) = 402.6 nm emitted by the impact-excited He atoms was measured as a function of an axial electric field (which varied from −30 kV cm −1 to +30 kV cm −1 ). By fitting the theoretical intensity functions to the measured ones, the post-collisional states of the atoms and their electric dipole moments were determined. The results indicate that for projectile energies below 20 keV, the electric dipole moments are small; however, for energies above 20 keV, mainly the parabolic Stark states with maximal electric dipole moments are excited. We conclude that in the upper section of the energy range investigated here, the Paul-trap promotion is the dominant excitation mechanism for He + –He collisions. (paper)

State Clean Energy Policies Analysis: State, Utility, and Municipal Loan Programs

Energy Technology Data Exchange (ETDEWEB)

Lantz, E.

2010-05-01

High initial costs can impede the deployment of clean energy technologies. Financing can reduce these costs. And, state, municipal, and utility-sponsored loan programs have emerged to fill the gap between clean energy technology financing needs and private sector lending. In general, public loan programs are more favorable to clean energy technologies than are those offered by traditional lending institutions; however, public loan programs address only the high up-front costs of clean energy systems, and the technology installed under these loan programs rarely supports clean energy production at levels that have a notable impact on the broader energy sector. This report discusses ways to increase the impact of these loan programs and suggests related policy design considerations.

Shifting the Sun: Solar Spectral Conversion and Extrinsic Sensitization in Natural and Artificial Photosynthesis.

Science.gov (United States)

Wondraczek, Lothar; Tyystjärvi, Esa; Méndez-Ramos, Jorge; Müller, Frank A; Zhang, Qinyuan

2015-12-01

Solar energy harvesting is largely limited by the spectral sensitivity of the employed energy conversion system, where usually large parts of the solar spectrum do not contribute to the harvesting scheme, and where, of the contributing fraction, the full potential of each photon is not efficiently used in the generation of electrical or chemical energy. Extrinsic sensitization through photoluminescent spectral conversion has been proposed as a route to at least partially overcome this problem. Here, we discuss this approach in the emerging context of photochemical energy harvesting and storage through natural or artificial photosynthesis. Clearly contrary to application in photovoltaic energy conversion, implementation of solar spectral conversion for extrinsic sensitization of a photosynthetic machinery is very straightforward, and-when compared to intrinsic sensitization-less-strict limitations with regard to quantum coherence are seen. We now argue the ways in which extrinsic sensitization through photoluminescent spectral converters will-and will not-play its role in the area of ultra-efficient photosynthesis, and also illustrate how such extrinsic sensitization requires dedicated selection of specific conversion schemes and design strategies on system scale.

Communication: State-to-state dynamics of the Cl + H2O → HCl + OH reaction: Energy flow into reaction coordinate and transition-state control of product energy disposal.

Science.gov (United States)

Zhao, Bin; Sun, Zhigang; Guo, Hua

2015-06-28

Quantum state-to-state dynamics of a prototypical four-atom reaction, namely, Cl + H2O → HCl + OH, is investigated for the first time in full dimensionality using a transition-state wave packet method. The state-to-state reactivity and its dependence on the reactant internal excitations are analyzed and found to share many similarities both energetically and dynamically with the H + H2O → H2 + OH reaction. The strong enhancement of reactivity by the H2O stretching vibrational excitations in both reactions is attributed to the favorable energy flow into the reaction coordinate near the transition state. On the other hand, the insensitivity of the product state distributions with regard to reactant internal excitation stems apparently from the transition-state control of product energy disposal.

Communication: State-to-state dynamics of the Cl + H2O → HCl + OH reaction: Energy flow into reaction coordinate and transition-state control of product energy disposal

International Nuclear Information System (INIS)

Zhao, Bin; Guo, Hua; Sun, Zhigang

2015-01-01

Quantum state-to-state dynamics of a prototypical four-atom reaction, namely, Cl + H 2 O → HCl + OH, is investigated for the first time in full dimensionality using a transition-state wave packet method. The state-to-state reactivity and its dependence on the reactant internal excitations are analyzed and found to share many similarities both energetically and dynamically with the H + H 2 O → H 2 + OH reaction. The strong enhancement of reactivity by the H 2 O stretching vibrational excitations in both reactions is attributed to the favorable energy flow into the reaction coordinate near the transition state. On the other hand, the insensitivity of the product state distributions with regard to reactant internal excitation stems apparently from the transition-state control of product energy disposal

State energy conservation plan for New Mexico

Energy Technology Data Exchange (ETDEWEB)

None

1978-01-01

The energy-savings and energy-management programs set up by state agencies in New Mexico are presented. Also the energy-savings and energy-management programs for public schools are presented. Plans and summaries are also given for the following program: solar water heaters for secondary schools; solar portable classroom demonstration; energy-savings and energy-management programs for county and municipal governments; energy-savings programs for commercial and residential sectors; weatherization; solar sustenance; energy-savings programs for hospitals and industrial buildings; carpools and vanpools; a program encouraging compliance with the national 55-mph speed limit; waste-oil recycling; utilitites; agriculture; procurement; modification; public information; and an administrative packet containing information on how to facilitate internal accounting procedures.

High-resolution photoemission study of Ce1-x La x RhAs: A collapse of the energy gap in the Kondo semiconductor

International Nuclear Information System (INIS)

Shimada, K.; Higashiguchi, M.; Fujimori, S.-I.; Saitoh, Y.; Fujimori, A.; Namatame, H.; Taniguchi, M.; Sasakawa, T.; Takabatake, T.

2006-01-01

High-resolution resonance-photoemission spectroscopy has been performed on the Ce 1- x La x RhAs (0≤x≤0.05) single crystal to elucidate a collapse of the energy gap in the Kondo semiconductor CeRhAs by La substitution. With increasing x, the spectral intensity of the Ce4f 1 derived states near the Fermi level decreases and new 4f derived spectral feature appears at a higher binding energy. The Rh4d-derived states, on the other hand, are not significantly changed by the substitution. New 4f-derived states have incoherent nature, which is responsible for the collapse of the semiconducting state for x>∼0.02

Effects of spectral smearing on performance of the spectral ripple and spectro-temporal ripple tests.

Science.gov (United States)

Narne, Vijaya Kumar; Sharma, Mridula; Van Dun, Bram; Bansal, Shalini; Prabhu, Latika; Moore, Brian C J

2016-12-01

The main aim of this study was to use spectral smearing to evaluate the efficacy of a spectral ripple test (SRt) using stationary sounds and a recent variant with gliding ripples called the spectro-temporal ripple test (STRt) in measuring reduced spectral resolution. In experiment 1 the highest detectable ripple density was measured using four amounts of spectral smearing (unsmeared, mild, moderate, and severe). The thresholds worsened with increasing smearing and were similar for the SRt and the STRt across the three conditions with smearing. For unsmeared stimuli, thresholds were significantly higher (better) for the STRt than for the SRt. An amplitude fluctuation at the outputs of simulated (gammatone) auditory filters centered above 6400 Hz was identified as providing a potential detection cue for the STRt stimuli. Experiment 2 used notched noise with energy below and above the passband of the SRt and STRt stimuli to reduce confounding cues in the STRt. Thresholds were almost identical for the STRt and SRt for both unsmeared and smeared stimuli, indicating that the confounding cue for the STRt was eliminated by the notched noise. Thresholds obtained with notched noise present could be predicted reasonably accurately using an excitation-pattern model.

FUNDAMENTAL PARAMETERS AND SPECTRAL ENERGY DISTRIBUTIONS OF YOUNG AND FIELD AGE OBJECTS WITH MASSES SPANNING THE STELLAR TO PLANETARY REGIME

Energy Technology Data Exchange (ETDEWEB)

Filippazzo, Joseph C.; Rice, Emily L. [Department of Engineering Science and Physics, College of Staten Island, City University of New York, 2800 Victory Blvd, Staten Island, NY 10314 (United States); Faherty, Jacqueline; Cruz, Kelle L. [Department of Astrophysics, American Museum of Natural History, New York, NY 10024 (United States); Van Gordon, Mollie M. [Department of Geography, University of California, Berkeley, CA 94720 (United States); Looper, Dagny L. [Tisch School of the Arts, New York University, New York, NY 10003 (United States)

2015-09-10

We combine optical, near-infrared, and mid-infrared spectra and photometry to construct expanded spectral energy distributions for 145 field age (>500 Myr) and 53 young (lower age estimate <500 Myr) ultracool dwarfs (M6-T9). This range of spectral types includes very low mass stars, brown dwarfs, and planetary mass objects, providing fundamental parameters across both the hydrogen and deuterium burning minimum masses for the largest sample assembled to date. A subsample of 29 objects have well constrained ages as probable members of a nearby young moving group. We use 182 parallaxes and 16 kinematic distances to determine precise bolometric luminosities (L{sub bol}) and radius estimates from evolutionary models give semi-empirical effective temperatures (T{sub eff}) for the full range of young and field age late-M, L, and T dwarfs. We construct age-sensitive relationships of luminosity, temperature, and absolute magnitude as functions of spectral type and absolute magnitude to disentangle the effects of degenerate physical parameters such as T{sub eff}, surface gravity, and clouds on spectral morphology. We report bolometric corrections in J for both field age and young objects and find differences of up to a magnitude for late-L dwarfs. Our correction in Ks shows a larger dispersion but not necessarily a different relationship for young and field age sequences. We also characterize the NIR–MIR reddening of low gravity L dwarfs and identify a systematically cooler T{sub eff} of up to 300 K from field age objects of the same spectral type and 400 K cooler from field age objects of the same M{sub H} magnitude.

Ground state energy of a polaron in a superlattice

International Nuclear Information System (INIS)

Mensah, S.Y.; Allotey, F.K.A.; Nkrumah, G.; Mensah, N.G.

2000-10-01

The ground state energy of a polaron in a superlattice was calculated using the double-time Green functions. The effective mass of the polaron along the planes perpendicular to the superlattice axis was also calculated. The dependence of the ground state energy and the effective mass along the planes perpendicular to the superlattice axis on the electron-phonon coupling constant α and on the superlattice parameters (i.e. the superlattice period d and the bandwidth Δ) were studied. It was observed that if an infinite square well potential is assumed, the ground state energy of the polaron decreases (i.e. becomes more negative) with increasing α and d, but increases with increasing Δ. For small values of α, the polaron ground state energy varies slowly with Δ, becoming approximately constant for large Δ. The effective mass along the planes perpendicular to the superlattice axis was found to be approximately equal to the mass of an electron for all typical values of α, d and Δ. (author)

Continental integration and energy demand in the United States

International Nuclear Information System (INIS)

Manning, D.J.

2004-01-01

This presentation highlighted some of the major issues regarding energy demand in the United States and continental integration. The energy markets in Canada and the United States are economically integrated with large cross-border investment. Therefore, the energy infrastructure can be significantly affected by inconsistencies between the two countries in policy, regulatory processes and fiscal regimes. The author discussed the inelasticity in the natural gas demand in the United States in the near-term, and how natural gas consumption, particularly for power generation, is greater than North America's supply capacity. New supplies such as liquefied natural gas and arctic gas are needed to meet growing demands. The role of renewable energy technologies and energy efficiency was also discussed. It was emphasized that imbalances in supply and demand inevitably lead to price volatility and that high prices are a major obstacle to economic growth. tabs., figs

Semiconductor detectors in current energy dispersive X-ray spectral analysis

Energy Technology Data Exchange (ETDEWEB)

Betin, J; Zhabin, E; Krampit, I; Smirnov, V

1980-04-01

A review is presented of the properties of semiconductor detectors and of the possibilities stemming therefrom of using the detectors in X-ray spectral analysis in industries, in logging, in ecology and environmental control, in medicine, etc.

New York State Energy Research and Development Authority annual report, 1991--1992

International Nuclear Information System (INIS)

1992-01-01

To meet its energy and environmental goals, the Energy Authority faces a number of challenges affecting New York State's citizens. These include: Managing a nationally recognized energy research program of more than 250 ongoing projects located throughout the State that, through cutting-edge, energy-efficient technologies, identifies alternative energy sources; Participating in the joint Federal/State cleanup of a former nuclear fuel reprocessing plant at West Valley, an effort that will cost more than a billion dollars; Cleanup of the Malta Rocket Fuel Area Superfund site and maintenance of the shut-down State Low Level Radioactive Waste Disposal Area at West Valley; Issuing innovative tax-exempt bonds to finance utility projects, with $4.3 billion currently issued saving New York State citizens more than $4 billion; and Designing, building and operating a new low-level radioactive waste disposal facility for the State. In addition to these broad-based programs, the Energy Authority cosponsors the Student Energy Research Competition, a yearly science competition for high school students. Now in its eleventh year, the Competition continues to challenge students to explore solutions to meet our energy needs. This year, some 600 project proposals were submitted by 1217 students representing 85 schools throughout New York State. The Competition is cosponsored by the State Energy Office. Energy Authority programs help to ensure that, as we protect environmental values and promote economic growth, New York State has secure and economical future supplies of energy

EVIDENCE FOR TWO LOGNORMAL STATES IN MULTI-WAVELENGTH FLUX VARIATION OF FSRQ PKS 1510-089

Energy Technology Data Exchange (ETDEWEB)

Kushwaha, Pankaj; Misra, Ranjeev [Inter University Center for Astronomy and Astrophysics, Pune 411007 (India); Chandra, Sunil; Singh, K. P. [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Mumbai 400005 (India); Sahayanathan, S. [Astrophysical Sciences Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Baliyan, K. S., E-mail: pankajk@iucaa.in [Physical Research Laboratory, Ahmedabad 380009 (India)

2016-05-01

We present a systematic characterization of multi-wavelength emission from blazar PKS 1510-089 using well-sampled data at near-infrared (NIR), optical, X-ray, and γ -ray energies. The resulting flux distributions, except at X-rays, show two distinct lognormal profiles corresponding to a high and a low flux level. The dispersions exhibit energy-dependent behavior except in the LAT γ -ray and optical B-band. During the low level flux states, it is higher toward the peak of the spectral energy distribution, with γ -ray being intrinsically more variable followed by IR and then optical, consistent with mainly being a result of varying bulk Lorentz factor. On the other hand, the dispersions during the high state are similar in all bands except the optical B-band, where thermal emission still dominates. The centers of distributions are a factor of ∼4 apart, consistent with anticipation from studies of extragalactic γ -ray background with the high state showing a relatively harder mean spectral index compared to the low state.

Hybrid spectral CT reconstruction.

Directory of Open Access Journals (Sweden)

Darin P Clark

Full Text Available Current photon counting x-ray detector (PCD technology faces limitations associated with spectral fidelity and photon starvation. One strategy for addressing these limitations is to supplement PCD data with high-resolution, low-noise data acquired with an energy-integrating detector (EID. In this work, we propose an iterative, hybrid reconstruction technique which combines the spectral properties of PCD data with the resolution and signal-to-noise characteristics of EID data. Our hybrid reconstruction technique is based on an algebraic model of data fidelity which substitutes the EID data into the data fidelity term associated with the PCD reconstruction, resulting in a joint reconstruction problem. Within the split Bregman framework, these data fidelity constraints are minimized subject to additional constraints on spectral rank and on joint intensity-gradient sparsity measured between the reconstructions of the EID and PCD data. Following a derivation of the proposed technique, we apply it to the reconstruction of a digital phantom which contains realistic concentrations of iodine, barium, and calcium encountered in small-animal micro-CT. The results of this experiment suggest reliable separation and detection of iodine at concentrations ≥ 5 mg/ml and barium at concentrations ≥ 10 mg/ml in 2-mm features for EID and PCD data reconstructed with inherent spatial resolutions of 176 μm and 254 μm, respectively (point spread function, FWHM. Furthermore, hybrid reconstruction is demonstrated to enhance spatial resolution within material decomposition results and to improve low-contrast detectability by as much as 2.6 times relative to reconstruction with PCD data only. The parameters of the simulation experiment are based on an in vivo micro-CT experiment conducted in a mouse model of soft-tissue sarcoma. Material decomposition results produced from this in vivo data demonstrate the feasibility of distinguishing two K-edge contrast agents with

Hybrid spectral CT reconstruction

Science.gov (United States)

Clark, Darin P.

2017-01-01

Current photon counting x-ray detector (PCD) technology faces limitations associated with spectral fidelity and photon starvation. One strategy for addressing these limitations is to supplement PCD data with high-resolution, low-noise data acquired with an energy-integrating detector (EID). In this work, we propose an iterative, hybrid reconstruction technique which combines the spectral properties of PCD data with the resolution and signal-to-noise characteristics of EID data. Our hybrid reconstruction technique is based on an algebraic model of data fidelity which substitutes the EID data into the data fidelity term associated with the PCD reconstruction, resulting in a joint reconstruction problem. Within the split Bregman framework, these data fidelity constraints are minimized subject to additional constraints on spectral rank and on joint intensity-gradient sparsity measured between the reconstructions of the EID and PCD data. Following a derivation of the proposed technique, we apply it to the reconstruction of a digital phantom which contains realistic concentrations of iodine, barium, and calcium encountered in small-animal micro-CT. The results of this experiment suggest reliable separation and detection of iodine at concentrations ≥ 5 mg/ml and barium at concentrations ≥ 10 mg/ml in 2-mm features for EID and PCD data reconstructed with inherent spatial resolutions of 176 μm and 254 μm, respectively (point spread function, FWHM). Furthermore, hybrid reconstruction is demonstrated to enhance spatial resolution within material decomposition results and to improve low-contrast detectability by as much as 2.6 times relative to reconstruction with PCD data only. The parameters of the simulation experiment are based on an in vivo micro-CT experiment conducted in a mouse model of soft-tissue sarcoma. Material decomposition results produced from this in vivo data demonstrate the feasibility of distinguishing two K-edge contrast agents with a spectral

A novel approach for characterizing broad-band radio spectral energy distributions

Science.gov (United States)

Harvey, V. M.; Franzen, T.; Morgan, J.; Seymour, N.

2018-05-01

We present a new broad-band radio frequency catalogue across 0.12 GHz ≤ ν ≤ 20 GHz created by combining data from the Murchison Widefield Array Commissioning Survey, the Australia Telescope 20 GHz survey, and the literature. Our catalogue consists of 1285 sources limited by S20 GHz > 40 mJy at 5σ, and contains flux density measurements (or estimates) and uncertainties at 0.074, 0.080, 0.119, 0.150, 0.180, 0.408, 0.843, 1.4, 4.8, 8.6, and 20 GHz. We fit a second-order polynomial in log-log space to the spectral energy distributions of all these sources in order to characterize their broad-band emission. For the 994 sources that are well described by a linear or quadratic model we present a new diagnostic plot arranging sources by the linear and curvature terms. We demonstrate the advantages of such a plot over the traditional radio colour-colour diagram. We also present astrophysical descriptions of the sources found in each segment of this new parameter space and discuss the utility of these plots in the upcoming era of large area, deep, broad-band radio surveys.

Measurement of the Strange Spectral Function in Hadronic $\\tau$ Decays

CERN Document Server

Abbiendi, G.; Akesson, P.F.; Alexander, G.; Allison, John; Amaral, P.; Anagnostou, G.; Anderson, K.J.; Arcelli, S.; Asai, S.; Axen, D.; Azuelos, G.; Bailey, I.; Barberio, E.; Barillari, T.; Barlow, R.J.; Batley, R.J.; Bechtle, P.; Behnke, T.; Bell, Kenneth Watson; Bell, P.J.; Bella, G.; Bellerive, A.; Benelli, G.; Bethke, S.; Biebel, O.; Boeriu, O.; Bock, P.; Boutemeur, M.; Braibant, S.; Brigliadori, L.; Brown, Robert M.; Buesser, K.; Burckhart, H.J.; Campana, S.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, D.G.; Ciocca, C.; Csilling, A.; Cuffiani, M.; Dado, S.; De Roeck, A.; De Wolf, E.A.; Desch, K.; Dienes, B.; Donkers, M.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Etzion, E.; Fabbri, F.; Feld, L.; Ferrari, P.; Fiedler, F.; Fleck, I.; Ford, M.; Frey, A.; Gagnon, P.; Gary, John William; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Giunta, Marina; Goldberg, J.; Gross, E.; Grunhaus, J.; Gruwe, M.; Gunther, P.O.; Gupta, A.; Hajdu, C.; Hamann, M.; Hanson, G.G.; Harel, A.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Herten, G.; Heuer, R.D.; Hill, J.C.; Hoffman, Kara Dion; Horvath, D.; Igo-Kemenes, P.; Ishii, K.; Jeremie, H.; Jovanovic, P.; Junk, T.R.; Kanaya, N.; Kanzaki, J.; Karlen, D.; Kawagoe, K.; Kawamoto, T.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Klein, K.; Klier, A.; Kluth, S.; Kobayashi, T.; Kobel, M.; Komamiya, S.; Kramer, T.; Krieger, P.; von Krogh, J.; Kruger, K.; Kuhl, T.; Kupper, M.; Lafferty, G.D.; Landsman, H.; Lanske, D.; Layter, J.G.; Lellouch, D.; Lettso, J.; Levinson, L.; Lillich, J.; Lloyd, S.L.; Loebinger, F.K.; Lu, J.; Ludwig, A.; Ludwig, J.; Mader, W.; Marcellini, S.; Martin, A.J.; Masetti, G.; Mashimo, T.; Mattig, Peter; McKenna, J.; McPherson, R.A.; Meijers, F.; Menges, W.; Menke, S.; Merritt, F.S.; Mes, H.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Moed, S.; Mohr, W.; Mori, T.; Mutter, A.; Nagai, K.; Nakamura, I.; Nanjo, H.; Neal, H.A.; Nisius, R.; O'Neale, S.W.; Oh, A.; Okpara, A.; Oreglia, M.J.; Orito, S.; Pahl, C.; Pasztor, G.; Pater, J.R.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poli, B.; Pooth, O.; Przybycien, M.; Quadt, A.; Rabbertz, K.; Rembser, C.; Renkel, P.; Roney, J.M.; Rosati, S.; Rozen, Y.; Runge, K.; Sachs, K.; Saeki, T.; Sarkisyan, E.K.G.; Schaile, A.D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schorner-Sadenius, T.; Schroder, Matthias; Schumacher, M.; Scott, W.G.; Seuster, R.; Shears, T.G.; Shen, B.C.; Sherwood, P.; Skuja, A.; Smith, A.M.; Sobie, R.; Soldner-Rembold, S.; Spano, F.; Stahl, A.; Strom, David M.; Strohmer, R.; Tarem, S.; Tasevsky, M.; Teuscher, R.; Thomson, M.A.; Torrence, E.; Toya, D.; Tran, P.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turner-Watson, M.F.; Ueda, I.; Ujvari, B.; Vollmer, C.F.; Vannerem, P.; Vertesi, R.; Verzocchi, M.; Voss, H.; Vossebeld, J.; Waller, D.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wengler, T.; Wermes, N.; Wetterling, D.; Wilson, G.W.; Wilson, J.A.; Wolf, G.; Wyatt, T.R.; Yamashita, S.; Zer-Zion, D.; Zivkovic, Lidija

2004-01-01

Tau Lepton decays with open strangeness in the final state are measured with the OPAL detector at LEP to determine the strange hadronic spectral function of the tau lepton. The decays tau- -> (Kpi)-nu tau, (Kpipi)-nu tau and (Kpipipi)-nu tau with final states consisting of neutral and charged kaons and pions have been studied. The invariant mass distributions of 93.4% of these final states have been experimentally determined. Monte Carlo simulations have been used for the remaining 6.6% and for the strange final states including eta mesons. The reconstructed strange final states, corrected for resolution effects and detection efficiencies, yield the strange spectral function of the tau lepton. The moments of the spectral function and the ratio of strange to non-strange moments, which are important input parameters for theoretical analyses, are determined. Furthermore, the branching fractions B(tau- -> K-pi0nu tau) = (0.471+-0.059stat+-0.023sys)% and B(tau- -> K-pi+pi-nu tau) = (0.415+-0.053stat+-0.040sys)% ha...

Spectral analysis and filter theory in applied geophysics

CERN Document Server

Buttkus, Burkhard

2000-01-01

This book is intended to be an introduction to the fundamentals and methods of spectral analysis and filter theory and their appli­ cations in geophysics. The principles and theoretical basis of the various methods are described, their efficiency and effectiveness eval­ uated, and instructions provided for their practical application. Be­ sides the conventional methods, newer methods arediscussed, such as the spectral analysis ofrandom processes by fitting models to the ob­ served data, maximum-entropy spectral analysis and maximum-like­ lihood spectral analysis, the Wiener and Kalman filtering methods, homomorphic deconvolution, and adaptive methods for nonstation­ ary processes. Multidimensional spectral analysis and filtering, as well as multichannel filters, are given extensive treatment. The book provides a survey of the state-of-the-art of spectral analysis and fil­ ter theory. The importance and possibilities ofspectral analysis and filter theory in geophysics for data acquisition, processing an...

Perturbation approach to the self-energy of non-S hydrogenic states

International Nuclear Information System (INIS)

Le Bigot, Eric-Olivier; Jentschura, Ulrich D.; Mohr, Peter J.; Indelicato, Paul; Soff, Gerhard

2003-01-01

We present results on the self-energy correction to the energy levels of hydrogen and hydrogenlike ions. The self-energy represents the largest QED correction to the relativistic (Dirac-Coulomb) energy of a bound electron. We focus on the perturbation expansion of the self-energy of non-S states, and provide estimates of the so-called A 60 perturbation coefficient, which can be viewed as a relativistic Bethe logarithm. Precise values of A 60 are given for many P, D, F, and G states, while estimates are given for other states. These results can be used in high-precision spectroscopy experiments in hydrogen and hydrogenlike ions. They yield the best available estimate of the self-energy correction of many atomic states

A SEARCH FOR SPECTRAL HYSTERESIS AND ENERGY-DEPENDENT TIME LAGS FROM X-RAY AND TeV GAMMA-RAY OBSERVATIONS OF Mrk 421

International Nuclear Information System (INIS)

Abeysekara, A. U.; Flinders, A.; Archambault, S.; Feng, Q.; Archer, A.; Buckley, J. H.; Bugaev, V.; Benbow, W.; Cerruti, M.; Bird, R.; Buchovecky, M.; Cardenzana, J. V; Eisch, J. D.; Chen, X.; Ciupik, L.; Connolly, M. P.; Cui, W.; Finley, J. P.; Falcone, A.; Fleischhack, H.

2017-01-01

Blazars are variable emitters across all wavelengths over a wide range of timescales, from months down to minutes. It is therefore essential to observe blazars simultaneously at different wavelengths, especially in the X-ray and gamma-ray bands, where the broadband spectral energy distributions usually peak. In this work, we report on three “target-of-opportunity” observations of Mrk 421, one of the brightest TeV blazars, triggered by a strong flaring event at TeV energies in 2014. These observations feature long, continuous, and simultaneous exposures with XMM-Newton (covering the X-ray and optical/ultraviolet bands) and VERITAS (covering the TeV gamma-ray band), along with contemporaneous observations from other gamma-ray facilities (MAGIC and Fermi -Large Area Telescope) and a number of radio and optical facilities. Although neither rapid flares nor significant X-ray/TeV correlation are detected, these observations reveal subtle changes in the X-ray spectrum of the source over the course of a few days. We search the simultaneous X-ray and TeV data for spectral hysteresis patterns and time delays, which could provide insight into the emission mechanisms and the source properties (e.g., the radius of the emitting region, the strength of the magnetic field, and related timescales). The observed broadband spectra are consistent with a one-zone synchrotron self-Compton model. We find that the power spectral density distribution at ≳4 × 10 −4 Hz from the X-ray data can be described by a power-law model with an index value between 1.2 and 1.8, and do not find evidence for a steepening of the power spectral index (often associated with a characteristic length scale) compared to the previously reported values at lower frequencies.

A SEARCH FOR SPECTRAL HYSTERESIS AND ENERGY-DEPENDENT TIME LAGS FROM X-RAY AND TeV GAMMA-RAY OBSERVATIONS OF Mrk 421

Energy Technology Data Exchange (ETDEWEB)

Abeysekara, A. U.; Flinders, A. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Archambault, S.; Feng, Q. [Physics Department, McGill University, Montreal, QC H3A 2T8 (Canada); Archer, A.; Buckley, J. H.; Bugaev, V. [Department of Physics, Washington University, St. Louis, MO 63130 (United States); Benbow, W.; Cerruti, M. [Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645 (United States); Bird, R.; Buchovecky, M. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Cardenzana, J. V; Eisch, J. D. [Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); Chen, X. [Institute of Physics and Astronomy, University of Potsdam, D-14476 Potsdam-Golm (Germany); Ciupik, L. [Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605 (United States); Connolly, M. P. [School of Physics, National University of Ireland Galway, University Road, Galway (Ireland); Cui, W.; Finley, J. P. [Department of Physics and Astronomy, Purdue University, West Lafayette, IN 47907 (United States); Falcone, A. [Department of Astronomy and Astrophysics, 525 Davey Lab, Pennsylvania State University, University Park, PA 16802 (United States); Fleischhack, H. [DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Collaboration: VERITAS Collaboration; MAGIC Collaboration; and others

2017-01-01

Blazars are variable emitters across all wavelengths over a wide range of timescales, from months down to minutes. It is therefore essential to observe blazars simultaneously at different wavelengths, especially in the X-ray and gamma-ray bands, where the broadband spectral energy distributions usually peak. In this work, we report on three “target-of-opportunity” observations of Mrk 421, one of the brightest TeV blazars, triggered by a strong flaring event at TeV energies in 2014. These observations feature long, continuous, and simultaneous exposures with XMM-Newton (covering the X-ray and optical/ultraviolet bands) and VERITAS (covering the TeV gamma-ray band), along with contemporaneous observations from other gamma-ray facilities (MAGIC and Fermi -Large Area Telescope) and a number of radio and optical facilities. Although neither rapid flares nor significant X-ray/TeV correlation are detected, these observations reveal subtle changes in the X-ray spectrum of the source over the course of a few days. We search the simultaneous X-ray and TeV data for spectral hysteresis patterns and time delays, which could provide insight into the emission mechanisms and the source properties (e.g., the radius of the emitting region, the strength of the magnetic field, and related timescales). The observed broadband spectra are consistent with a one-zone synchrotron self-Compton model. We find that the power spectral density distribution at ≳4 × 10{sup −4} Hz from the X-ray data can be described by a power-law model with an index value between 1.2 and 1.8, and do not find evidence for a steepening of the power spectral index (often associated with a characteristic length scale) compared to the previously reported values at lower frequencies.

Spectral-Timing Analysis of Kilohetrz Quasi-Periodic Osciallations in Neutron Star Low-Mass X-ray Binaries

Science.gov (United States)

Cackett, Edward; Troyer, Jon; Peille, Philippe; Barret, Didier

2018-01-01

Kilohertz quasi-periodic oscillations or kHz QPOs are intensity variations that occur in the X-ray band observed in neutron star low-mass X-ray binary (LMXB) systems. In such systems, matter is transferred from a secondary low-mass star to a neutron star via the process of accretion. kHz QPOs occur on the timescale of the inner accretion flow and may carry signatures of the physics of strong gravity (c2 ~ GM/R) and possibly clues to constraining the neutron star equation of state (EOS). Both the timing behavior of kHz QPOs and the time-averaged spectra of these systems have been studied extensively. No model derived from these techniques has been able to illuminate the origin of kHz QPOs. Spectral-timing is an analysis technique that can be used to derive information about the nature of physical processes occurring within the accretion flow on the timescale of the kHz QPO. To date, kHz QPOs of (4) neutron star LMXB systems have been studied with spectral-timing techniques. We present a comprehensive study of spectral-timing products of kHz QPOs from systems where data is available in the RXTE archive to demonstrate the promise of this technique to gain insights regarding the origin of kHz QPOs. Using data averaged over the entire RXTE archive, we show correlated time-lags as a function of QPO frequency and energy, as well as energy-dependent covariance spectra for the various LMXB systems where spectral-timing analysis is possible. We find similar trends in all average spectral-timing products for the objects studied. This suggests a common origin of kHz QPOs.

Semiconductor detectors in current energy dispersive X-ray spectral analysis

International Nuclear Information System (INIS)

Betin, J.; Zhabin, E.; Krampit, I.; Smirnov, V.

1980-01-01

A review is presented of the properties of semiconductor detectors and of the possibilities stemming therefrom of using the detectors in X-ray spectral analysis in industries, in logging, in ecology and environmental control, in medicine, etc. (M.S.)

Ground state energy fluctuations in the nuclear shell model

International Nuclear Information System (INIS)

Velazquez, Victor; Hirsch, Jorge G.; Frank, Alejandro; Barea, Jose; Zuker, Andres P.

2005-01-01

Statistical fluctuations of the nuclear ground state energies are estimated using shell model calculations in which particles in the valence shells interact through well-defined forces, and are coupled to an upper shell governed by random 2-body interactions. Induced ground-state energy fluctuations are found to be one order of magnitude smaller than those previously associated with chaotic components, in close agreement with independent perturbative estimates based on the spreading widths of excited states

Photoinduced energy and electron transfer in rubrene-benzoquinone and rubrene-porphyrin systems

KAUST Repository

Khan, Jafar Iqbal

2014-11-01

Excited-state electron and energy transfer from singlet excited rubrene (Ru) to benzoquinone (BQ) and tetra-(4-aminophenyl) porphyrin (TAPP) were investigated by steady-state absorption and emission, time-resolved transient absorption, and femtosecond (fs)-nanosecond (ns) fluorescence spectroscopy. The low reduction potential of BQ provides the high probability of electron transfer from the excited Ru to BQ. Steady-state and time-resolved results confirm such an excited electron transfer scenario. On the other hand, strong spectral overlap between the emission of Ru and absorption of TAPP suggests that energy transfer is a possible deactivation pathway of the Ru excited state.

State estimation for wave energy converters

Energy Technology Data Exchange (ETDEWEB)

Bacelli, Giorgio; Coe, Ryan Geoffrey

2017-04-01

This report gives a brief discussion and examples on the topic of state estimation for wave energy converters (WECs). These methods are intended for use to enable real-time closed loop control of WECs.

Resonant excitation and the decay of autoionization states in a strong electromagnetic field

International Nuclear Information System (INIS)

Andryushin, A.I.; Kazakov, A.E.; Fedorov, M.V.

1985-01-01

Photoionization of atoms involving resonant excitation of the auto-ionization state is studied. The evolution of the total ionization probability, its dependence on the frequency of the resonance radiation and also the photoelectron energy spectrum are investigated. It is shown that the energy of the final state of the system may be localized either in the vicinity of E approximately Esub(α), where Esub(α) is the auto-ionization energy, or in the vicinity of E approximately Esub(α)+h/2πω where h/2πω is the quantum energy of the resonance radiation. The photoelectron specturum in the region E approximately Esub(α)+h/2πω as a whole is similar to the electron spectrum on photoionization of atoms involving resonance excitation of the bound state. A strong effect on the photoelectron spectrum in the region E approximately Esub(α) is exerted by interference of various decay channels of the ground state in the resonance field which leads to the appearance in the spectrum of a characteristic structure of the Fano type. Interence also affects the widths of the two spectral curves, the relatve amount of electrons in the two energy ranges and also other characteristics of the ionization process. It is shown that the presence of a noninterfering photoionization channel of the autoionization state ensures the finiteness of the swidths and heights of the spectral curves and the absence of complete ''coherency merging''

Comprehensive spectral analysis of Cyg X-1 using RXTE data

International Nuclear Information System (INIS)

Shahid, Rizwan; Jaaffrey, S. N. A.; Misra, Ranjeev

2012-01-01

We analyze a large number (> 500) of pointed Rossi X-Ray Timing Explorer (RXTE) observations of Cyg X-1 and model the spectrum of each one. A subset of the observations for which there is a simultaneous reliable measure of the hardness ratio by the All Sky Monitor shows that the sample covers nearly all the spectral shapes of Cyg X-1. Each observation is fitted with a generic empirical model consisting of a disk black body spectrum, a Comptonized component whose input photon shape is the same as the disk emission, a Gaussian to represent the iron line and a reflection feature. The relative strength, width of the iron line and the reflection parameter are in general correlated with the high energy photon spectral index Γ. This is broadly consistent with a geometry where for the hard state (low Γ ∼ 1.7) there is a hot inner Comptonizing region surrounded by a truncated cold disk. The inner edge of the disk moves inwards as the source becomes softer till finally in the soft state (high Γ > 2.2) the disk fills the inner region and active regions above the disk produce the Comptonized component. However, the reflection parameter shows non-monotonic behavior near the transition region (Γ ∼ 2), which suggests a more complex geometry or physical state of the reflector. In addition, the inner disk temperature, during the hard state, is on average higher than in the soft one, albeit with large scatter. These inconsistencies could be due to limitations in the data and the empirical model used to fit them. The flux of each spectral component is well correlated with Γ, which shows that unlike some other black hole systems, Cyg X-1 does not show any hysteresis behavior. In the soft state, the flux of the Comptonized component is always similar to the disk one, which confirms that the ultra-soft state (seen in other brighter black hole systems) is not exhibited by Cyg X-1. The rapid variation of the Compton amplification factor with Γ naturally explains the absence of

Improving regulatory effectiveness in Federal/State siting actions. State perspectives on energy facility siting

International Nuclear Information System (INIS)

Stevens, D.W.; Helminski, E.L.

1978-03-01

The National Governors' Association, through its Committee on Natural Resources and Environmental Management, has been concerned with the growing administrative difficulties, both at the federal and state levels, of certifying sites for new major energy facilities. This concern led, early in 1977, to the creation of a Subcommittee on Energy Facility Siting to comprehensively analyze current conditions and determine how basic improvements might be made to the process. The report is meant to further clarify the issues that confront States and the Federal government in the siting of energy facilities

A spectral chart method for estimating the mean turbulent kinetic energy dissipation rate

Energy Technology Data Exchange (ETDEWEB)

Djenidi, L.; Antonia, R.A. [The University of Newcastle, School of Engineering, Newcastle, NSW (Australia)

2012-10-15

We present an empirical but simple and practical spectral chart method for determining the mean turbulent kinetic energy dissipation rate left angle {epsilon}right angle in a variety of turbulent flows. The method relies on the validity of the first similarity hypothesis of Kolmogorov (C R (Doklady) Acad Sci R R SS, NS 30:301-305, 1941) (or K41) which implies that spectra of velocity fluctuations scale on the kinematic viscosity {nu} and left angle {epsilon}right angle at large Reynolds numbers. However, the evidence, based on the DNS spectra, points to this scaling being also valid at small Reynolds numbers, provided effects due to inhomogeneities in the flow are negligible. The methods avoid the difficulty associated with estimating time or spatial derivatives of the velocity fluctuations. It also avoids using the second hypothesis of K41, which implies the existence of a -5/3 inertial subrange only when the Taylor microscale Reynolds number R{sub {lambda}} is sufficiently large. The method is in fact applied to the lower wavenumber end of the dissipative range thus avoiding most of the problems due to inadequate spatial resolution of the velocity sensors and noise associated with the higher wavenumber end of this range.The use of spectral data (30 {<=} R{sub {lambda}}{<=} 400) in both passive and active grid turbulence, a turbulent mixing layer and the turbulent wake of a circular cylinder indicates that the method is robust and should lead to reliable estimates of left angle {epsilon}right angle in flows or flow regions where the first similarity hypothesis should hold; this would exclude, for example, the region near a wall. (orig.)

Simulated galaxy interactions as probes of merger spectral energy distributions

Energy Technology Data Exchange (ETDEWEB)

Lanz, Lauranne; Zezas, Andreas; Smith, Howard A.; Ashby, Matthew L. N.; Fazio, Giovanni G.; Hernquist, Lars [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Hayward, Christopher C. [Heidelberger Institut für Theoretische Studien, Schloss-Wolfsbrunnenweg 35, D-69118 Heidelberg (Germany); Brassington, Nicola, E-mail: llanz@ipac.caltech.edu [School of Physics, Astronomy and Mathematics, University of Hertfordshire, College Lane, Hatfield, AL10 9AB (United Kingdom)

2014-04-10

We present the first systematic comparison of ultraviolet-millimeter spectral energy distributions (SEDs) of observed and simulated interacting galaxies. Our sample is drawn from the Spitzer Interacting Galaxy Survey and probes a range of galaxy interaction parameters. We use 31 galaxies in 14 systems which have been observed with Herschel, Spitzer, GALEX, and 2MASS. We create a suite of GADGET-3 hydrodynamic simulations of isolated and interacting galaxies with stellar masses comparable to those in our sample of interacting galaxies. Photometry for the simulated systems is then calculated with the SUNRISE radiative transfer code for comparison with the observed systems. For most of the observed systems, one or more of the simulated SEDs match reasonably well. The best matches recover the infrared luminosity and the star formation rate of the observed systems, and the more massive systems preferentially match SEDs from simulations of more massive galaxies. The most morphologically distorted systems in our sample are best matched to the simulated SEDs that are close to coalescence, while less evolved systems match well with the SEDs over a wide range of interaction stages, suggesting that an SED alone is insufficient for identifying the interaction stage except during the most active phases in strongly interacting systems. This result is supported by our finding that the SEDs calculated for simulated systems vary little over the interaction sequence.

Spectral flow, and the spectrum of multicenter solutions

International Nuclear Information System (INIS)

Bena, Iosif; Bobev, Nikolay; Warner, Nicholas P.

2008-01-01

We discuss 'spectral-flow' coordinate transformations that take asymptotically four-dimensional solutions into other asymptotically four-dimensional solutions. We find that spectral flow can relate smooth three-charge solutions with a multicenter Taub-NUT base to solutions where one or several Taub-NUT centers are replaced by two-charge supertubes, and vice versa. We further show that multiparameter spectral flows can map such Taub-NUT centers to more singular centers that are either D2-D0 or pure D0-brane sources. Since supertubes can depend on arbitrary functions, we establish that the moduli space of smooth horizonless black-hole microstate solutions is classically of infinite dimension. We also use the physics of supertubes to argue that some multicenter solutions that appear to be bound states from a four-dimensional perspective are in fact not bound states when considered from a five- or six-dimensional perspective

Novel methods for estimating lithium-ion battery state of energy and maximum available energy

International Nuclear Information System (INIS)

Zheng, Linfeng; Zhu, Jianguo; Wang, Guoxiu; He, Tingting; Wei, Yiying

2016-01-01

Highlights: • Study on temperature, current, aging dependencies of maximum available energy. • Study on the various factors dependencies of relationships between SOE and SOC. • A quantitative relationship between SOE and SOC is proposed for SOE estimation. • Estimate maximum available energy by means of moving-window energy-integral. • The robustness and feasibility of the proposed approaches are systematic evaluated. - Abstract: The battery state of energy (SOE) allows a direct determination of the ratio between the remaining and maximum available energy of a battery, which is critical for energy optimization and management in energy storage systems. In this paper, the ambient temperature, battery discharge/charge current rate and cell aging level dependencies of battery maximum available energy and SOE are comprehensively analyzed. An explicit quantitative relationship between SOE and state of charge (SOC) for LiMn_2O_4 battery cells is proposed for SOE estimation, and a moving-window energy-integral technique is incorporated to estimate battery maximum available energy. Experimental results show that the proposed approaches can estimate battery maximum available energy and SOE with high precision. The robustness of the proposed approaches against various operation conditions and cell aging levels is systematically evaluated.

Free Magnetic Energy in Solar Active Regions above the Minimum-Energy Relaxed State

OpenAIRE

Regnier, S.; Priest, E. R.

2008-01-01

To understand the physics of solar flares, including the local reorganization of the magnetic field and the acceleration of energetic particles, we have first to estimate the free magnetic energy available for such phenomena, which can be converted into kinetic and thermal energy. The free magnetic energy is the excess energy of a magnetic configuration compared to the minimum-energy state, which is a linear force-free field if the magnetic helicity of the configuration is conserved. We inves...

State Energy Efficiency Resource Standards: Design, Status, and Impacts

Energy Technology Data Exchange (ETDEWEB)

Steinberg, D.; Zinaman, O.

2014-05-01

An energy efficiency resource standard (EERS) is a policy that requires utilities or other entities to achieve a specified amount of energy savings through customer energy efficiency programs within a specified timeframe. EERSs may apply to electricity usage, natural gas usage, or both. This paper provides an overview of the key design features of EERSs for electricity, reviews the variation in design of EERSs across states, and provides an estimate of the amount of savings required by currently specified EERSs in each state. As of December, 2013, 23 states have active and binding EERSs for electricity. We estimate that state EERSs will require annual electricity savings of approximately 8-11% of total projected demand by 2020 in states with EERSs, however the level of savings targeted by the policies varies significantly across states. In addition to the variation in targeted savings, the design of EERSs varies significantly across states leading to differences in the suite of incentives created by the policy, the flexibility of compliance with the policy, the balance of benefits and costs of the policy between producers and consumers, and the certainty with which the policy will drive long-term savings.

Spectral Variation of NLS1 Galaxy PMN J0948+0022

Indian Academy of Sciences (India)

2016-01-27

Jan 27, 2016 ... Four well-sampled Spectral Energy Distributions (SEDs) of PMN J0948+0022 are fitted with the syn+SSC+EC model to derive the physical parameters of its jets and to investigate the spectral variations of its SEDs. A tentative correlation between the peak luminosity (c) and peak frequency (c) of its ...

Spectral Induced Polarization Response of Biofilm Formation in Hanford Vadose Zone Sediment

Science.gov (United States)

Garcia, A.; Katsenovich, Y.; Lee, B.; Whitman, D.

2017-12-01

As a result of the U.S. Nuclear weapons program during the second world war and the cold war, there now exists a significant amount of uranium contamination at the U.S. Department of Energy Hanford site located in Washington state. In-situ immobilization of mobile uranium via injections of a soluble sodium tripolyphosphate amendment may prove effective in the formation of insoluble uranyl phosphate mineral, autunite. However, the injected polyphosphate undergoes hydrolysis in aqueous solutions to form orthophosphate, which serves as a readily available nutrient for the various microorganisms in the sediment. Sediment-filled column experiments conducted under saturated oxygen restricted conditions using geophysical Spectral Induced Polarization technique have shown the impact of microbes on the dissolution of autunite, a calcium uranyl phosphate mineral. Spectral Induced Polarization may be an effective way to track changes indicative of bacterial activities on the surrounding environment. This method can be a cost-effective alternative to the drilling of boreholes at a field scale.

Green energy laws and Republican legislators in the United States

International Nuclear Information System (INIS)

Coley, Jonathan S.; Hess, David J.

2012-01-01

The policy context for green energy laws in the United States has changed over the past few years, because the Republican Party has increasingly opposed renewable electricity and other green energy policies. In this study, we draw on a database of 6071 votes on RPS (renewable portfolio standards) and PACE (Property-Assessed Clean Energy) laws by individual state legislators in the United States to examine the circumstances shaping Republican votes for green energy laws from 2007–2011. We find that votes on these laws are indeed increasingly partisan, with Republicans supporting RPS laws especially less than Democrats. However, Republicans' support for these laws is higher in states with weaker fossil fuel industries. Furthermore, Republicans tend to support the laws where median household income is lower, environmental organizations are weaker, labor-environmental coalitions are absent, and the proportion of Democrats in the legislature is lower, suggesting a reactive effect against green energy policies in more progressive settings. - Highlights: ► We analyze Republican votes for state RPS and PACE laws from 2007–2011. ► Support for RPS laws declined, while support for PACE laws remained steady. ► Support for both laws is lower in states with strong fossil fuel industries. ► Support for both laws is lower in more Democratic legislatures.

The radio spectral energy distribution of infrared-faint radio sources

Science.gov (United States)

Herzog, A.; Norris, R. P.; Middelberg, E.; Seymour, N.; Spitler, L. R.; Emonts, B. H. C.; Franzen, T. M. O.; Hunstead, R.; Intema, H. T.; Marvil, J.; Parker, Q. A.; Sirothia, S. K.; Hurley-Walker, N.; Bell, M.; Bernardi, G.; Bowman, J. D.; Briggs, F.; Cappallo, R. J.; Callingham, J. R.; Deshpande, A. A.; Dwarakanath, K. S.; For, B.-Q.; Greenhill, L. J.; Hancock, P.; Hazelton, B. J.; Hindson, L.; Johnston-Hollitt, M.; Kapińska, A. D.; Kaplan, D. L.; Lenc, E.; Lonsdale, C. J.; McKinley, B.; McWhirter, S. R.; Mitchell, D. A.; Morales, M. F.; Morgan, E.; Morgan, J.; Oberoi, D.; Offringa, A.; Ord, S. M.; Prabu, T.; Procopio, P.; Udaya Shankar, N.; Srivani, K. S.; Staveley-Smith, L.; Subrahmanyan, R.; Tingay, S. J.; Wayth, R. B.; Webster, R. L.; Williams, A.; Williams, C. L.; Wu, C.; Zheng, Q.; Bannister, K. W.; Chippendale, A. P.; Harvey-Smith, L.; Heywood, I.; Indermuehle, B.; Popping, A.; Sault, R. J.; Whiting, M. T.

2016-10-01

Context. Infrared-faint radio sources (IFRS) are a class of radio-loud (RL) active galactic nuclei (AGN) at high redshifts (z ≥ 1.7) that are characterised by their relative infrared faintness, resulting in enormous radio-to-infrared flux density ratios of up to several thousand. Aims: Because of their optical and infrared faintness, it is very challenging to study IFRS at these wavelengths. However, IFRS are relatively bright in the radio regime with 1.4 GHz flux densities of a few to a few tens of mJy. Therefore, the radio regime is the most promising wavelength regime in which to constrain their nature. We aim to test the hypothesis that IFRS are young AGN, particularly GHz peaked-spectrum (GPS) and compact steep-spectrum (CSS) sources that have a low frequency turnover. Methods: We use the rich radio data set available for the Australia Telescope Large Area Survey fields, covering the frequency range between 150 MHz and 34 GHz with up to 19 wavebands from different telescopes, and build radio spectral energy distributions (SEDs) for 34 IFRS. We then study the radio properties of this class of object with respect to turnover, spectral index, and behaviour towards higher frequencies. We also present the highest-frequency radio observations of an IFRS, observed with the Plateau de Bure Interferometer at 105 GHz, and model the multi-wavelength and radio-far-infrared SED of this source. Results: We find IFRS usually follow single power laws down to observed frequencies of around 150 MHz. Mostly, the radio SEDs are steep (α IFRS show statistically significantly steeper radio SEDs than the broader RL AGN population. Our analysis reveals that the fractions of GPS and CSS sources in the population of IFRS are consistent with the fractions in the broader RL AGN population. We find that at least % of IFRS contain young AGN, although the fraction might be significantly higher as suggested by the steep SEDs and the compact morphology of IFRS. The detailed multi

Spectral structure of mesoscale winds over the water

DEFF Research Database (Denmark)

Larsén, Xiaoli Guo; Vincent, Claire Louise; Larsen, Søren Ejling

2013-01-01

to describe the spectral slope transition as well as the limit for application of the Taylor hypothesis. The stability parameter calculated from point measurements, the bulk Richardson number, is found insufficient to represent the various atmospheric structures that have their own spectral behaviours under...... spectra show universal characteristics, in agreement with the findings in literature, including the energy amplitude and the −5/3 spectral slope in the mesoscale range transitioning to a slope of −3 for synoptic and planetary scales. The integral time-scale of the local weather is found to be useful...... different stability conditions, such as open cells and gravity waves. For stationary conditions, the mesoscale turbulence is found to bear some characteristics of two-dimensional isotropy, including (1) very minor vertical variation of spectra; (2) similar spectral behaviour for the along- and across...

Simultaneous spectral and temporal analyses of kinetic energies in nonequilibrium systems: theory and application to vibrational relaxation of O-D stretch mode of HOD in water.

Science.gov (United States)

Jeon, Jonggu; Lim, Joon Hyung; Kim, Seongheun; Kim, Heejae; Cho, Minhaeng

2015-05-28

A time series of kinetic energies (KE) from classical molecular dynamics (MD) simulation contains fundamental information on system dynamics. It can also be analyzed in the frequency domain through Fourier transformation (FT) of velocity correlation functions, providing energy content of different spectral regions. By limiting the FT time span, we have previously shown that spectral resolution of KE evolution is possible in the nonequilibrium situations [Jeon and Cho, J. Chem. Phys. 2011, 135, 214504]. In this paper, we refine the method by employing the concept of instantaneous power spectra, extending it to reflect an instantaneous time-correlation of velocities with those in the future as well as with those in the past, and present a new method to obtain the instantaneous spectral density of KE (iKESD). This approach enables the simultaneous spectral and temporal resolution of KE with unlimited time precision. We discuss the formal and novel properties of the new iKESD approaches and how to optimize computational methods and determine parameters for practical applications. The method is specifically applied to the nonequilibrium MD simulation of vibrational relaxation of the OD stretch mode in a hydrated HOD molecule by employing a hybrid quantum mechanical/molecular mechanical (QM/MM) potential. We directly compare the computational results with the OD band population relaxation time profiles extracted from the IR pump-probe measurements for 5% HOD in water. The calculated iKESD yields the OD bond relaxation time scale ∼30% larger than the experimental value, and this decay is largely frequency-independent if the classical anharmonicity is accounted for. From the integrated iKESD over intra- and intermolecular bands, the major energy transfer pathways were found to involve the HOD bending mode in the subps range, then the internal modes of the solvent until 5 ps after excitation, and eventually the solvent intermolecular modes. Also, strong hydrogen

An implicit spectral formula for generalized linear Schroedinger equations

International Nuclear Information System (INIS)

Schulze-Halberg, A.; Garcia-Ravelo, J.; Pena Gil, Jose Juan

2009-01-01

We generalize the semiclassical Bohr–Sommerfeld quantization rule to an exact, implicit spectral formula for linear, generalized Schroedinger equations admitting a discrete spectrum. Special cases include the position-dependent mass Schroedinger equation or the Schroedinger equation for weighted energy. Requiring knowledge of the potential and the solution associated with the lowest spectral value, our formula predicts the complete spectrum in its exact form. (author)

Increased power spectral density in resting-state pain-related brain networks in fibromyalgia.

Science.gov (United States)

Kim, Ji-Young; Kim, Seong-Ho; Seo, Jeehye; Kim, Sang-Hyon; Han, Seung Woo; Nam, Eon Jeong; Kim, Seong-Kyu; Lee, Hui Joong; Lee, Seung-Jae; Kim, Yang-Tae; Chang, Yongmin

2013-09-01

Fibromyalgia (FM), characterized by chronic widespread pain, is known to be associated with heightened responses to painful stimuli and atypical resting-state functional connectivity among pain-related regions of the brain. Previous studies of FM using resting-state functional magnetic resonance imaging (rs-fMRI) have focused on intrinsic functional connectivity, which maps the spatial distribution of temporal correlations among spontaneous low-frequency fluctuation in functional MRI (fMRI) resting-state data. In the current study, using rs-fMRI data in the frequency domain, we investigated the possible alteration of power spectral density (PSD) of low-frequency fluctuation in brain regions associated with central pain processing in patients with FM. rsfMRI data were obtained from 19 patients with FM and 20 age-matched healthy female control subjects. For each subject, the PSDs for each brain region identified from functional connectivity maps were computed for the frequency band of 0.01 to 0.25 Hz. For each group, the average PSD was determined for each brain region and a 2-sample t test was performed to determine the difference in power between the 2 groups. According to the results, patients with FM exhibited significantly increased frequency power in the primary somatosensory cortex (S1), supplementary motor area (SMA), dorsolateral prefrontal cortex, and amygdala. In patients with FM, the increase in PSD did not show an association with depression or anxiety. Therefore, our findings of atypical increased frequency power during the resting state in pain-related brain regions may implicate the enhanced resting-state baseline neural activity in several brain regions associated with pain processing in FM. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Joint Spectral Analysis for Early Bright X-ray Flares of γ-Ray Bursts ...

Indian Academy of Sciences (India)

Abstract. A joint spectral analysis for early bright X-ray flares that were simultaneously observed with Swift BAT and XRT are present. Both BAT and XRT lightcurves of these flares are correlated. Our joint spectral anal- ysis shows that the radiations in the two energy bands are from the same spectral component, which can ...

Optimized Energy Efficiency and Spectral Efficiency Resource Allocation Strategies for Phantom Cellular Networks

KAUST Repository

Abdelhady, Amr, M.; Amin, Osama; Alouini, Mohamed-Slim

2016-01-01

Multi-teir hetrogeneous networks have become an essential constituent for next generation cellular networks. Meanwhile, energy efficiency (EE) has been considered a critical design criterion along with the traditional spectral efficiency (SE) metric. In this context, we study power and spectrum allocation for the recently proposed two-teir architecture known as Phantom cellular networks. The optimization framework includes both EE and SE, where we propose an algorithm that computes the SE and EE resource allocation for Phantom cellular networks. Then, we compare the performance of both design strategies versus the number of users, and the ration of Phantom cellresource blocks to the total number or resource blocks. We aim to investigate the effect of some system parameters to acheive improved SE or EE performance at a non-significant loss in EE or SE performance, respectively. It was found that the system parameters can be tuned so that the EE solution does not yield a significant loss in the SE performance.

Optimized Energy Efficiency and Spectral Efficiency Resource Allocation Strategies for Phantom Cellular Networks

KAUST Repository

Abdelhady, Amr, M.

2016-01-06

Multi-teir hetrogeneous networks have become an essential constituent for next generation cellular networks. Meanwhile, energy efficiency (EE) has been considered a critical design criterion along with the traditional spectral efficiency (SE) metric. In this context, we study power and spectrum allocation for the recently proposed two-teir architecture known as Phantom cellular networks. The optimization framework includes both EE and SE, where we propose an algorithm that computes the SE and EE resource allocation for Phantom cellular networks. Then, we compare the performance of both design strategies versus the number of users, and the ration of Phantom cellresource blocks to the total number or resource blocks. We aim to investigate the effect of some system parameters to acheive improved SE or EE performance at a non-significant loss in EE or SE performance, respectively. It was found that the system parameters can be tuned so that the EE solution does not yield a significant loss in the SE performance.

Plasma satellites of X-ray spectral lines of ions in a plasma of solid-state targets, heated by a picosecond laser pulse

International Nuclear Information System (INIS)

Belyaev, V.S.; Vinogradov, V.I.; Kurilov, A.S.; Matafonov, A.P.; Lisitsa, V.S.; Gavrilenko, V.P.; Faenov, A.Ya.; Pikuz, T.A.; Skobelev, I.Yu.; Magunov, A.I.; Pikuz, S.A.

2003-01-01

The results of measuring the ions X-ray spectral lines by the interaction of the picosecond laser pulses with the solid-state target are presented. The spectra of the X-ray radiation were observed on the fluorine ion line. The spectral lines satellites, testifying to the availability, are identified. The position of the satellites and the distance between them make it possible to connect them with the intensive electrostatic oscillations with the amplitude, exceeding 10 8 V/cm, and the frequency close to 7 x 10 14 s -1 , substantially lower than the laser wave frequency. The experimental results are compared with the calculated data on the multicharge ions spectra [ru

Efficient basis formulation for 1+1 dimensional SU(2) lattice gauge theory. Spectral calculations with matrix product states

Energy Technology Data Exchange (ETDEWEB)

Banuls, Mari Carmen; Cirac, J. Ignacio; Kuehn, Stefan [Max-Planck-Institut fuer Quantenoptik (MPQ), Garching (Germany); Cichy, Krzysztof [Frankfurt Univ. (Germany). Inst. fuer Theoretische Physik; Adam Mickiewicz Univ., Poznan (Poland). Faculty of Physics; Jansen, Karl [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC

2017-07-20

We propose an explicit formulation of the physical subspace for a 1+1 dimensional SU(2) lattice gauge theory, where the gauge degrees of freedom are integrated out. Our formulation is completely general, and might be potentially suited for the design of future quantum simulators. Additionally, it allows for addressing the theory numerically with matrix product states. We apply this technique to explore the spectral properties of the model and the effect of truncating the gauge degrees of freedom to a small finite dimension. In particular, we determine the scaling exponents for the vector mass. Furthermore, we also compute the entanglement entropy in the ground state and study its scaling towards the continuum limit.

Efficient Basis Formulation for (1+1-Dimensional SU(2 Lattice Gauge Theory: Spectral Calculations with Matrix Product States

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