Science.gov

Sample records for absolute energy distributions

  1. Ultraviolet photometry from the Orbiting Astronomical Observatory. XXI - Absolute energy distribution of stars in the ultraviolet

    NASA Technical Reports Server (NTRS)

    Bless, R. C.; Code, A. D.; Fairchild, E. T.

    1976-01-01

    The absolute energy distribution in the ultraviolet is given for the stars alpha Vir, eta UMa, and alpha Leo. The calibration is based on absolute heterochromatic photometry between 2920 and 1370 A carried out with an Aerobee sounding rocket. The fundamental radiation standard is the synchrotron radiation from 240-MeV electrons in a certain synchrotron storage ring. On the basis of the sounding-rocket calibration, the preliminary OAO-2 spectrometer calibration has been revised; the fluxes for the three program stars are tabulated in energy per second per square centimeter per unit wavelength interval.

  2. Momentum Distribution and Ground-State Energy of Liquid 4He at the Absolute Zero Temperature

    NASA Astrophysics Data System (ADS)

    Nishiyama, T.; Watanabe, Y.

    1980-11-01

    In the scheme of the density and phase operator approach, the momentum distribution nk and the ground-state energy E0 are obtained by employing the structure factor and the radial distribution function calculated by Chang and Campbell for the Morse dipole-dipole potential. The condensate fraction, the ratio of the occupation number of the single-particle zero-momentum state N0/N amounts to 0.096. The momentum distribution diverges as k-1 in the low-wave number limit. The ground-state energy becomes E0=-6.9NK at the mean density ρ0=0.02185Å-3.

  3. Absolute energy distributions of Al, Cu, and Ta ions produced by nanosecond laser-generated plasmas at 1013 Wcm-2

    NASA Astrophysics Data System (ADS)

    Comet, M.; Versteegen, M.; Gobet, F.; Denis-Petit, D.; Hannachi, F.; Meot, V.; Tarisien, M.

    2016-01-01

    The charge state and energy distributions of ions produced by a pulsed 1 J, 9 ns Nd:YAG laser focused onto solid aluminum, copper, and tantalum targets were measured with an electrostatic analyzer coupled with a windowless electron multiplier detector. Special attention was paid to the detector response function measurements and to the determination of the analyzer transmission. Space charge effects are shown to strongly affect this transmission. Measured absolute energy distributions are presented for several charge states. They follow Boltzmann-like functions characterized by an effective ion temperature and an equivalent accelerating voltage. These parameters exhibit power laws as a function of I λ 2 which open the possibility to predict the expected shape of the relative energy distributions of ions on a large range of laser intensities (106-1016 Wcm-2 μm2).

  4. Absolute energy distribution in the spectra of 32 Cygni. Eclipses of 1987 and 1990

    NASA Astrophysics Data System (ADS)

    Burnashev, V. I.; Burnasheva, B. A.

    2011-06-01

    The photometric observations during 1953-1994 were used for the construction of the summary light curve for 32 Cygni in the photometric UBV-system. On the basis of energy distribution data, the spectral classes and luminosities of the components of this binary system were obtained. The column density of HI during several ingresses and egresses was estimated, suggesting that the depression at λ 3650 Å was caused by hydrogen absorption.

  5. Redetermining CEBAF's Absolute Energy

    NASA Astrophysics Data System (ADS)

    Su, Tong; Jlab Marathon Collaboration

    2015-04-01

    With the upgrade of the Jefferson Lab accelerator (CEBAF) from 6 GeV max energy to 12 GeV, all the dipole magnets in the machine were refurbished. Most of them were switched from open c-shaped to closed h-shaped by adding extra iron. With these upgraded magnets, the energy calibration of the accelerator needed to be redetermined. We will show how an extra external dipole, which is run in series with those in the machine, helps us cross check the current in the magnets as well as precisely map out the integral field for any machine setting. Using knowledge of the relative performance of the dipoles as well as the bend angle into the Hall, has allowed us to already determine a 4th pass 7 GeV beam to better than 7 MeV. In the future, we will use g-2 spin precession as a second independent energy determination. This work is supported by Kent State University, NSF Grant PHY-1405814, and DOE Contract DE-AC05-06OR23177 (JLab).

  6. Absolute-magnitude distributions of supernovae

    SciTech Connect

    Richardson, Dean; Wright, John; Jenkins III, Robert L.; Maddox, Larry

    2014-05-01

    The absolute-magnitude distributions of seven supernova (SN) types are presented. The data used here were primarily taken from the Asiago Supernova Catalogue, but were supplemented with additional data. We accounted for both foreground and host-galaxy extinction. A bootstrap method is used to correct the samples for Malmquist bias. Separately, we generate volume-limited samples, restricted to events within 100 Mpc. We find that the superluminous events (M{sub B} < –21) make up only about 0.1% of all SNe in the bias-corrected sample. The subluminous events (M{sub B} > –15) make up about 3%. The normal Ia distribution was the brightest with a mean absolute blue magnitude of –19.25. The IIP distribution was the dimmest at –16.75.

  7. Comparison of high energy gamma rays from absolute value of b greater than 30 deg with the galactic neutral hydrogen distribution

    NASA Technical Reports Server (NTRS)

    Ozel, M. E.; Ogelman, H.; Tumer, T.; Fichtel, C. E.; Hartman, R. C.; Kniffen, D. A.; Thompson, F. J.

    1978-01-01

    High-energy gamma-ray (energy above 35 MeV) data from the SAS 2 satellite have been used to compare the intensity distribution of gamma rays with that of neutral hydrogen (H I) density along the line of sight, at high galactic latitudes (absolute values greater than 30 deg). A model has been constructed for the case where the observed gamma-ray intensity has been assumed to be the sum of a galactic component proportional to the H I distribution plus an isotropic extragalactic emission. A chi-squared test of the model parameters indicates that about 30% of the total high-latitude emission may originate within the Galaxy.

  8. Absolute nonlocality via distributed computing without communication

    NASA Astrophysics Data System (ADS)

    Czekaj, Ł.; Pawłowski, M.; Vértesi, T.; Grudka, A.; Horodecki, M.; Horodecki, R.

    2015-09-01

    Understanding the role that quantum entanglement plays as a resource in various information processing tasks is one of the crucial goals of quantum information theory. Here we propose an alternative perspective for studying quantum entanglement: distributed computation of functions without communication between nodes. To formalize this approach, we propose identity games. Surprisingly, despite no signaling, we obtain that nonlocal quantum strategies beat classical ones in terms of winning probability for identity games originating from certain bipartite and multipartite functions. Moreover we show that, for a majority of functions, access to general nonsignaling resources boosts success probability two times in comparison to classical ones for a number of large enough outputs. Because there are no constraints on the inputs and no processing of the outputs in the identity games, they detect very strong types of correlations: absolute nonlocality.

  9. Absolute nuclear material assay using count distribution (LAMBDA) space

    DOEpatents

    Prasad, Mano K.; Snyderman, Neal J.; Rowland, Mark S.

    2015-12-01

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  10. Absolute nuclear material assay using count distribution (LAMBDA) space

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2012-06-05

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  11. Absolute surface energy for zincblende semiconductors

    NASA Astrophysics Data System (ADS)

    Zhang, S. B.; Wei, Su-Huai

    2003-03-01

    Recent advance in nanosciences requires the determination of surface (or facet) energy of semiconductors, which is often difficult due to the polar nature of some of the most important surfaces such as the (111)A/(111)B surfaces. Several approaches have been developed in the past [1-3] to deal with the problem but an unambiguous division of the polar surface energies is yet to come [2]. Here we show that an accurate division is indeed possible for the zincblende semiconductors and will present the results for GaAs, ZnSe, and CuInSe2 [4], respectively. A general trend emerges, relating the absolute surface energy to the ionicity of the bulk materials. [1] N. Chetty and R. M. Martin, Phys. Rev. B 45, 6074 (1992). [2] N. Moll, et al., Phys. Rev. B 54, 8844 (1996). [3] S. Mankefors, Phys. Rev. B 59, 13151 (1999). [4] S. B. Zhang and S.-H. Wei, Phys. Rev. B 65, 081402 (2002).

  12. Ultraviolet photochemistry of buta-1,3- and buta-1,2-dienes: Laser spectroscopic absolute hydrogen atom quantum yield and translational energy distribution measurements

    SciTech Connect

    Hanf, A.; Volpp, H.-R.; Sharma, P.; Mittal, J. P.; Vatsa, R. K.

    2010-07-14

    Using pulsed H-atom Lyman-{alpha} laser-induced fluorescence spectroscopy along with a photolytic calibration approach, absolute H-atom product quantum yields of {phi}{sub H-b13d}=(0.32{+-}0.04) and {phi}{sub H-b12d}=(0.36{+-}0.04) were measured under collision-free conditions for the 193 nm gas-phase laser flash photolysis of buta-1,3- and buta-1,2-diene at room temperature, which demonstrate that nascent H-atom formation is of comparable importance for both parent molecules. Comparison of the available energy fraction, f{sub T-b13d}=(0.22{+-}0.03) and f{sub T-b12d}=(0.13{+-}0.01), released as H+C{sub 4}H{sub 5} product translational energy with results of impulsive and statistical energy partitioning modeling calculations indicates that for both, buta-1,3- and buta-1,2-diene, H-atom formation is preceded by internal conversion to the respective electronic ground state (S{sub 0}) potential energy surfaces. In addition, values of {sigma}{sub b-1,3-d-L{alpha}=}(3.5{+-}0.2)x10{sup -17} cm{sup 2} and {sigma}{sub b-1,2-d-L{alpha}=}(4.4{+-}0.2)x10{sup -17} cm{sup 2} for the previously unknown Lyman-{alpha} (121.6 nm) radiation photoabsorption cross sections of buta-1,3- and buta-1,2-diene in the gas-phase were determined.

  13. The absolute magnitude distribution of Kuiper Belt objects

    SciTech Connect

    Fraser, Wesley C.; Brown, Michael E.; Morbidelli, Alessandro; Parker, Alex; Batygin, Konstantin

    2014-02-20

    Here we measure the absolute magnitude distributions (H-distribution) of the dynamically excited and quiescent (hot and cold) Kuiper Belt objects (KBOs), and test if they share the same H-distribution as the Jupiter Trojans. From a compilation of all useable ecliptic surveys, we find that the KBO H-distributions are well described by broken power laws. The cold population has a bright-end slope, α{sub 1}=1.5{sub −0.2}{sup +0.4}, and break magnitude, H{sub B}=6.9{sub −0.2}{sup +0.1} (r'-band). The hot population has a shallower bright-end slope of, α{sub 1}=0.87{sub −0.2}{sup +0.07}, and break magnitude H{sub B}=7.7{sub −0.5}{sup +1.0}. Both populations share similar faint-end slopes of α{sub 2} ∼ 0.2. We estimate the masses of the hot and cold populations are ∼0.01 and ∼3 × 10{sup –4} M {sub ⊕}. The broken power-law fit to the Trojan H-distribution has α{sub 1} = 1.0 ± 0.2, α{sub 2} = 0.36 ± 0.01, and H {sub B} = 8.3. The Kolmogorov-Smirnov test reveals that the probability that the Trojans and cold KBOs share the same parent H-distribution is less than 1 in 1000. When the bimodal albedo distribution of the hot objects is accounted for, there is no evidence that the H-distributions of the Trojans and hot KBOs differ. Our findings are in agreement with the predictions of the Nice model in terms of both mass and H-distribution of the hot and Trojan populations. Wide-field survey data suggest that the brightest few hot objects, with H{sub r{sup ′}}≲3, do not fall on the steep power-law slope of fainter hot objects. Under the standard hierarchical model of planetesimal formation, it is difficult to account for the similar break diameters of the hot and cold populations given the low mass of the cold belt.

  14. Absolute surface energies, fracture toughness, and cracking in nitrides

    NASA Astrophysics Data System (ADS)

    Dreyer, Cyrus E.; Janotti, Anderson; van de Walle, Chris G.

    2014-03-01

    Growth of high quality single crystals and epitaxial layers of GaN is critical for producing high-efficiency optoelectronic and power electronic devices. One of the fundamental material properties that govern growth of single crystals is the absolute surface energy of the crystallographic planes. Knowledge of these energies is required to understand and optimize growth rates of different facets in GaN, and provide fracture toughnesses for brittle fracture. By means of hybrid functional calculations, we have determined absolute surface energies for the non-polar {11-20} a and {10-10} m planes, and approximated values for polar (0001) + c and (000-1) - c planes in wurtzite GaN. For all surfaces, we consider low-energy bare and hydrogenated reconstructions under a variety of conditions relevant to experimental growth techniques. We find that the energies of the m and a planes are similar, and constant over the range of conditions studied. In contrast, the energies of the polar planes are strongly condition dependent. Even so, we find that the + c polar plane is systematically lower in energy than the - c plane. We have used our surface energies to determine brittle fracture toughnesses in AlN and GaN, as well as the critical thickness for cracking of AlGaN on GaN.

  15. The Absolute Differential Area Technique for Testing Distributional Normality.

    ERIC Educational Resources Information Center

    Bennett, Richard P.

    The results of a study of find alternative techniques for testing distributional normality are presented. A group of statistical techniques--some established and some new--were compared using empirical techniques. One new technique which appears to have higher power than the Lilliefors test was subjected to a better definition. Distributions under…

  16. Absolute determination of inelastic mean-free paths and surface excitation parameters by absolute reflection electron energy loss spectrum analysis

    NASA Astrophysics Data System (ADS)

    Nagatomi, T.; Goto, K.

    2005-11-01

    An analytical approach was proposed for simultaneously determining an inelastic mean-free path (IMFP) and a surface excitation parameter (SEP) with absolute units by the analysis of an absolute experimental reflection electron energy loss spectrum. The IMFPs and SEPs in Ni were deduced for electrons of 300 to 3000 eV. The obtained IMFPs were in good agreement with those calculated using the TPP-2M equation. The Chen-type empirical formula was proposed for determining the SEP. The results confirmed the applicability of the present approach for determining the IMFP and SEP for medium-energy electrons.

  17. Dark Energy:. the Absolute Electric Potential of the Universe

    NASA Astrophysics Data System (ADS)

    Jiménez, Jose Beltrán; Maroto, Antonio L.

    Is there an absolute cosmic electric potential? The recent discovery of the accelerated expansion of the universe could be indicating that this is certainly the case. In this essay we show that the consistency of the covariant and gauge-invariant theory of electromagnetism is truly questionable when considered on cosmological scales. Out of the four components of the electromagnetic field, Maxwell's theory contains only two physical degrees of freedom. However, in the presence of gravity, one of the "unphysical" states cannot be consistently eliminated, thus becoming real. This third polarization state is completely decoupled from charged matter, but can be excited gravitationally, thus breaking gauge invariance. On large scales the new state can be seen as a homogeneous cosmic electric potential, whose energy density behaves as a cosmological constant.

  18. Fully distributed absolute blood flow velocity measurement for middle cerebral arteries using Doppler optical coherence tomography.

    PubMed

    Qi, Li; Zhu, Jiang; Hancock, Aneeka M; Dai, Cuixia; Zhang, Xuping; Frostig, Ron D; Chen, Zhongping

    2016-02-01

    Doppler optical coherence tomography (DOCT) is considered one of the most promising functional imaging modalities for neuro biology research and has demonstrated the ability to quantify cerebral blood flow velocity at a high accuracy. However, the measurement of total absolute blood flow velocity (BFV) of major cerebral arteries is still a difficult problem since it is related to vessel geometry. In this paper, we present a volumetric vessel reconstruction approach that is capable of measuring the absolute BFV distributed along the entire middle cerebral artery (MCA) within a large field-of-view. The Doppler angle at each point of the MCA, representing the vessel geometry, is derived analytically by localizing the artery from pure DOCT images through vessel segmentation and skeletonization. Our approach could achieve automatic quantification of the fully distributed absolute BFV across different vessel branches. Experiments on rodents using swept-source optical coherence tomography showed that our approach was able to reveal the consequences of permanent MCA occlusion with absolute BFV measurement. PMID:26977365

  19. Fully distributed absolute blood flow velocity measurement for middle cerebral arteries using Doppler optical coherence tomography

    PubMed Central

    Qi, Li; Zhu, Jiang; Hancock, Aneeka M.; Dai, Cuixia; Zhang, Xuping; Frostig, Ron D.; Chen, Zhongping

    2016-01-01

    Doppler optical coherence tomography (DOCT) is considered one of the most promising functional imaging modalities for neuro biology research and has demonstrated the ability to quantify cerebral blood flow velocity at a high accuracy. However, the measurement of total absolute blood flow velocity (BFV) of major cerebral arteries is still a difficult problem since it is related to vessel geometry. In this paper, we present a volumetric vessel reconstruction approach that is capable of measuring the absolute BFV distributed along the entire middle cerebral artery (MCA) within a large field-of-view. The Doppler angle at each point of the MCA, representing the vessel geometry, is derived analytically by localizing the artery from pure DOCT images through vessel segmentation and skeletonization. Our approach could achieve automatic quantification of the fully distributed absolute BFV across different vessel branches. Experiments on rodents using swept-source optical coherence tomography showed that our approach was able to reveal the consequences of permanent MCA occlusion with absolute BFV measurement. PMID:26977365

  20. Pretreatment verification of IMRT absolute dose distributions using a commercial a-Si EPID

    SciTech Connect

    Talamonti, C.; Casati, M.; Bucciolini, M.

    2006-11-15

    A commercial amorphous silicon electronic portal imaging device (EPID) has been studied to investigate its potential in the field of pretreatment verifications of step and shoot, intensity modulated radiation therapy (IMRT), 6 MV photon beams. The EPID was calibrated to measure absolute exit dose in a water-equivalent phantom at patient level, following an experimental approach, which does not require sophisticated calculation algorithms. The procedure presented was specifically intended to replace the time-consuming in-phantom film dosimetry. The dosimetric response was characterized on the central axis in terms of stability, linearity, and pulse repetition frequency dependence. The a-Si EPID demonstrated a good linearity with dose (within 2% from 1 monitor unit), which represent a prerequisite for the application in IMRT. A series of measurements, in which phantom thickness, air gap between the phantom and the EPID, field size and position of measurement of dose in the phantom (entrance or exit) varied, was performed to find the optimal calibration conditions, for which the field size dependence is minimized. In these conditions (20 cm phantom thickness, 56 cm air gap, exit dose measured at the isocenter), the introduction of a filter for the low-energy scattered radiation allowed us to define a universal calibration factor, independent of field size. The off-axis extension of the dose calibration was performed by applying a radial correction for the beam profile, distorted due to the standard flood field calibration of the device. For the acquisition of IMRT fields, it was necessary to employ home-made software and a specific procedure. This method was applied for the measurement of the dose distributions for 15 clinical IMRT fields. The agreement between the dose distributions, quantified by the gamma index, was found, on average, in 97.6% and 98.3% of the analyzed points for EPID versus TPS and for EPID versus FILM, respectively, thus suggesting a great

  1. Absolute pitch in Costa Rica: Distribution of pitch identification ability and implications for its genetic basis.

    PubMed

    Chavarria-Soley, Gabriela

    2016-08-01

    Absolute pitch is the unusual ability to recognize a pitch without an external reference. The current view is that both environmental and genetic factors are involved in the acquisition of the trait. In the present study, 127 adult musicians were subjected to a musical tone identification test. Subjects were university music students and volunteers who responded to a newspaper article. The test consisted of the identification of 40 piano and 40 pure tones. Subjects were classified in three categories according to their pitch naming ability: absolute pitch (AP), high accuracy of tone identification (HA), and non-absolute pitch (non-AP). Both the percentage of correct responses and the mean absolute deviation showed a statistically significant variation between categories. A very clear pattern of higher accuracy for white than for black key notes was observed for the HA and the non-AP groups. Meanwhile, the AP group had an almost perfect pitch naming accuracy for both kinds of tones. Each category presented a very different pattern of deviation around the correct response. The age at the beginning of musical training did not differ between categories. The distribution of pitch identification ability in this study suggests a complex inheritance of the trait. PMID:27586721

  2. Method to calibrate the absolute energy scale of air showers with ultrahigh energy photons.

    PubMed

    Homola, Piotr; Risse, Markus

    2014-04-18

    Calibrating the absolute energy scale of air showers initiated by ultrahigh energy (UHE) cosmic rays is an important experimental issue. Currently, the corresponding systematic uncertainty amounts to 14%-21% using the fluorescence technique. Here, we describe a new, independent method which can be applied if ultrahigh energy photons are observed. While such photon-initiated showers have not yet been identified, the capabilities of present and future cosmic-ray detectors may allow their discovery. The method makes use of the geomagnetic conversion of UHE photons (preshower effect), which significantly affects the subsequent longitudinal shower development. The conversion probability depends on photon energy and can be calculated accurately by QED. The comparison of the observed fraction of converted photon events to the expected one allows the determination of the absolute energy scale of the observed photon air showers and, thus, an energy calibration of the air shower experiment. We provide details of the method and estimate the accuracy that can be reached as a function of the number of observed photon showers. Already a very small number of UHE photons may help to test and fix the absolute energy scale. PMID:24785024

  3. The absolute configuration of chrysomelidial: a widely distributed defensive component among oribotririid mites (Acari: Oribatida).

    PubMed

    Shimizu, Nobuhiro; Yakumaru, Ryota; Sakata, Tomoyo; Shimano, Satoshi; Kuwahara, Yasumasa

    2012-01-01

    The absolute configuration of the iridoid monoterpene chrysomelidial from the oribatid mite, Austrotritia dentate Aoki, was elucidated by the GC-MS and GC comparisons with four synthetic stereoisomers of this well-known natural product. This identification was made possible by asymmetric synthesis of the known alcohol, (5S,8S)-chrysomelidiol. The GC retention time of diol derived from the natural oribatid dial agreed with that of the synthetic (5S,8S)-chrysomelidiol, confirming that the absolute configurations at C5 and C8 positions of the natural chrysomelidial are both S. Chrysomelidial was detected as a single or a major component in nine oribatid mites examined; thus, this compound is considered to be commonly distributed in Oribotririidae where it serves a defensive role. PMID:22246522

  4. The Spatial Distribution of Absolute Skeletal Muscle Deoxygenation During Ramp-Incremental Exercise Is Not Influenced by Hypoxia.

    PubMed

    Bowen, T Scott; Koga, Shunsaku; Amano, Tatsuro; Kondo, Narihiko; Rossiter, Harry B

    2016-01-01

    Time-resolved near-infrared spectroscopy (TRS-NIRS) allows absolute quantitation of deoxygenated haemoglobin and myoglobin concentration ([HHb]) in skeletal muscle. We recently showed that the spatial distribution of peak [HHb] within the quadriceps during moderate-intensity cycling is reduced with progressive hypoxia and this is associated with impaired aerobic energy provision. We therefore aimed to determine whether reduced spatial distribution of skeletal muscle [HHb] was associated with impaired aerobic energy transfer during exhaustive ramp-incremental exercise in hypoxia. Seven healthy men performed ramp-incremental cycle exercise (20 W/min) to exhaustion at 3 fractional inspired O2 concentrations (FIO2): 0.21, 0.16, 0.12. Pulmonary O2 uptake ([Formula: see text]) was measured using a flow meter and gas analyser system. Lactate threshold (LT) was estimated non-invasively. Absolute muscle deoxygenation was quantified by multichannel TRS-NIRS from the rectus femoris and vastus lateralis (proximal and distal regions). [Formula: see text] and LT were progressively reduced (p<0.05) with hypoxia. There was a significant effect (p<0.05) of FIO2 on [HHb] at baseline, LT, and peak. However the spatial variance of [HHb] was not different between FIO2 conditions. Peak total Hb ([Hbtot]) was significantly reduced between FIO2 conditions (p<0.001). There was no association between reductions in the spatial distribution of skeletal muscle [HHb] and indices of aerobic energy transfer during ramp-incremental exercise in hypoxia. While regional [HHb] quantified by TRS-NIRS at exhaustion was greater in hypoxia, the spatial distribution of [HHb] was unaffected. Interestingly, peak [Hbtot] was reduced at the tolerable limit in hypoxia implying a vasodilatory reserve may exist in conditions with reduced FIO2. PMID:26782190

  5. Absolute beam energy measurements in e+e- storage rings

    NASA Astrophysics Data System (ADS)

    Placidi, M.

    1997-01-01

    The CERN Large Electron Positron collider (LEP) was dedicated to the measurement of the mass Mz and the width Γz of the Z0 resonance during the LEP1 phase which terminated in September 1995. The Storage Ring operated in Energy Scan mode during the 1993 and 1995 physics runs by choosing the beam energy Ebeam to correspond to a center-of-mass (CM) energy at the interaction points (IPs) ECMpeak±1762 MeV. After a short review of the techniques usually adopted to set and control the beam energy, this paper describes in more detail two methods adopted at LEP for precise beam energy determination that are essential to reduce the contribution to the systematic error on Mz and Γz. The positron beam momentum was initially determined at the 20-GeV injection energy by measuring the speed of a less relativistic proton beam circulating on the same orbit, taking advantage of the unique opportunity to inject two beams into the LEP at short time intervals. The positron energy at the Z0 peak was in this case derived by extrapolation. Once transverse polarization became reproducible, the Resonant Depolarization (RD) technique was implemented at the Z0 operating energies, providing a ⩽2×10-5 instantaneous accuracy. RD Beam Energy Calibration has been adopted during the LEP Energy Scan campaigns as well as in Accelerator Physics runs for accurate measurement of machine parameters.

  6. Techniques of absolute low energy x-ray calibration

    SciTech Connect

    Day, R.H.

    1986-01-01

    Recent advances in pulsed plasma research, materials science, and astrophysics have required many new diagnostic instruments for use in the low energy x-ray regime. The characterization of these instruments has provided a challenge to instrument designers and provided the momentum to improve x-ray sources and dosimetry techniques. In this paper, the present state-of-the-art in low energy x-ray characterization techniques is reviewed. A summary is given of low energy x-ray generator technology and dosimetry techniques including a discussion of thin window proportional counters and ionization chambers. A review is included of the widely used x-ray data bases and a sample of ultrasoft x-ray measuring procedures, chopped x-ray source generators, phase sensitive detection of ultralow currents, and angular divergence measurements.

  7. The blue anbd visual absolute magnitude distributions of Type IA supernovae

    NASA Astrophysics Data System (ADS)

    Vaughan, Thomas E.; Branch, David; Miller, Douglas L.; Perlmutter, Saul

    1995-02-01

    Tully-Fisher (TF), surface brightness fluctuation (SBF), and Hubble law distances to the parent galaxies of Type Ia supernovae (SNs Ia) are used in order to study the SN Ia blue and visual peak absolute magnitude (MB and MV) distributions. We propose two objective cuts, each of which produces a subsample with small intrinsic dispersion in M. One cut, which can be applied to either band, distinguishes between a subsample of bright events and a smaller subsample of dim events, some of which were extinquished in the parent galaxy and some of which were intrinsically subluminous. The bright events are found to be distributed with an observed dispersions of 0.3 less than or approximately = Sigmaobs less than or approximately = 0.4 about a mean absolut magnitude (M-barB or M-barV). Each of the dim SNs was spectroscopically peculiar and/or had a red B-V color; this motivates the adoption of an alternative cut that is based on B-V rather than on M. To wit, SNs Ia that are both known to have -0.25 less than B-V less than + 0.25 and not known to be spectroscopically peculiar show observational dispersion of only Sigmaobs(MB) = Sigmaobs(MV) = 0.3. Because characteristics observational errors produce Sigmaerr(M) greater than 0.2,the intrinsic dispersion among such SNs Ia is Sigmaint(M) less than or approximately = 0.2. The small observational dispersion indicates that SNs Ia, the TF relation, and SBFs all good relative distances to those galaxies that produce SNs Ia. The conflict between those who use SNs Ia in order to determine the value of the Hubble constant (H0) and those who use TF and SBF distances to determine H0 results from discrepant calibrations.

  8. Absolute instability from linear conversion of counter-propagating positive and negative energy waves

    SciTech Connect

    Kaufman, A.N.; Brizard, A.J.; Morehead, J.J.; Tracy, E.R.

    1997-12-31

    The resonant interaction of a negative-energy wave with a positive-energy wave gives rise to a linear instability. Whereas a single crossing of rays in a nonuniform medium leads to a convectively saturated instability, we show that a double crossing can yield an absolute instability.

  9. Superharp: A wire scanner with absolute position readout for beam energy measurement at CEBAF

    SciTech Connect

    Yan, C.

    1994-09-07

    Superharp is an upgrade CEBAF wire scanner with absolute position readout from shaft encoder. As high precision absolute beam position probe ({Delta}x {approximately} 10{mu}m), three pairs of superharps are installed at the entrance, the mid-point, and the exit of Hall C arc beamline in beam switch yard, which will be tuned in dispersive mode as energy spectrometer performing 10{sup {minus}3} beam energy measurement. With dual sensor system: the direct current pickup and the bremsstrahlung detection electronics, beam profile can be obtained by superharp at wide beam current range from 1 {mu}A to 100 {mu}A.

  10. Slowed oxygen uptake kinetics in hypoxia correlate with the transient peak and reduced spatial distribution of absolute skeletal muscle deoxygenation.

    PubMed

    Bowen, T Scott; Rossiter, Harry B; Benson, Alan P; Amano, Tatsuro; Kondo, Narihiko; Kowalchuk, John M; Koga, Shunsaku

    2013-11-01

    It remains unclear whether an overshoot in skeletal muscle deoxygenation (HHb; reflecting a microvascular kinetic mismatch of O2 delivery to consumption) contributes to the slowed adjustment of oxidative energy provision at the onset of exercise. We progressively reduced the fractional inspired O2 concentration (F(I,O2)) to investigate the relationship between slowed pulmonary O2 uptake (V(O2)) kinetics and the dynamics and spatial distribution of absolute[HHb]. Seven healthy men performed 8 min cycling transitions during normoxia (F(I,O2) = 0.21),moderate hypoxia (F(I,O2) = 0.16) and severe hypoxia (F(I,O2)= 0.12). V(O2) uptake was measured using a flowmeter and gas analyser system. Absolute [HHb] was quantified by multichannel,time-resolved near-infrared spectroscopy from the rectus femoris and vastus lateralis (proximal and distal regions), and corrected for adipose tissue thickness. The phase II V(O2) time constant was slowed (P <0.05) as F(I,O2) decreased (normoxia, 17 ± 3 s;moderate hypoxia, 22 ± 4 s; and severe hypoxia, 29 ± 9 s). The [HHb] overshoot was unaffected by hypoxia, but the transient peak [HHb] increased with the reduction in F(I,O2) (P <0.05). Slowed V(O2) kinetics in hypoxia were positively correlated with increased peak [HHb] in the transient (r(2) = 0.45; P <0.05), but poorly related to the [HHb] overshoot. A reduction of spatial heterogeneity in peak [HHb]was inversely correlated with slowed V(O2) kinetics (r(2) = 0.49; P <0.05). These data suggest that aerobic energy provision at the onset of exercise may be limited by the following factors: (i) the absolute ratio (i.e. peak [HHb]) rather than the kinetic ratio (i.e. [HHb] overshoot) of microvascular O2 delivery to consumption; and (ii) a reduced spatial distribution in the ratio of microvascular O2 delivery to consumption across the muscle. PMID:23851917

  11. The spectral energy distribution of NGC 1275

    NASA Technical Reports Server (NTRS)

    Shields, G. A.; Oke, J. B.

    1975-01-01

    An analysis of absolute spectral energy distributions of interstellar gas for a galaxy (NGC 1275) is presented. Infrared spectra data shows heavy reddening. It is proposed that the interstellar gas may be ionized by shock waves or by nonthermal or stellar radiation. It is suggested, that high velocity, emission-line knots are H2 regions in a Perseus cluster galaxy or intergalactic gas cloud seen in projection against NGC 1275.

  12. Absolute Binding Free Energy Calculations: On the Accuracy of Computational Scoring of Protein-ligand Interactions

    PubMed Central

    Singh, Nidhi; Warshel, Arieh

    2010-01-01

    Calculating the absolute binding free energies is a challenging task. Reliable estimates of binding free energies should provide a guide for rational drug design. It should also provide us with deeper understanding of the correlation between protein structure and its function. Further applications may include identifying novel molecular scaffolds and optimizing lead compounds in computer-aided drug design. Available options to evaluate the absolute binding free energies range from the rigorous but expensive free energy perturbation to the microscopic Linear Response Approximation (LRA/β version) and its variants including the Linear Interaction Energy (LIE) to the more approximated and considerably faster scaled Protein Dipoles Langevin Dipoles (PDLD/S-LRA version), as well as the less rigorous Molecular Mechanics Poisson–Boltzmann/Surface Area (MM/PBSA) and Generalized Born/Surface Area (MM/GBSA) to the less accurate scoring functions. There is a need for an assessment of the performance of different approaches in terms of computer time and reliability. We present a comparative study of the LRA/β, the LIE, the PDLD/S-LRA/β and the more widely used MM/PBSA and assess their abilities to estimate the absolute binding energies. The LRA and LIE methods perform reasonably well but require specialized parameterization for the non-electrostatic term. On the average, the PDLD/S-LRA/β performs effectively. Our assessment of the MM/PBSA is less optimistic. This approach appears to provide erroneous estimates of the absolute binding energies due to its incorrect entropies and the problematic treatment of electrostatic energies. Overall, the PDLD/S-LRA/β appears to offer an appealing option for the final stages of massive screening approaches. PMID:20186976

  13. A simplified confinement method for calculating absolute free energies and free energy and entropy differences.

    PubMed

    Ovchinnikov, Victor; Cecchini, Marco; Karplus, Martin

    2013-01-24

    A simple and robust formulation of the path-independent confinement method for the calculation of free energies is presented. The simplified confinement method (SCM) does not require matrix diagonalization or switching off the molecular force field, and has a simple convergence criterion. The method can be readily implemented in molecular dynamics programs with minimal or no code modifications. Because the confinement method is a special case of thermodynamic integration, it is trivially parallel over the integration variable. The accuracy of the method is demonstrated using a model diatomic molecule, for which exact results can be computed analytically. The method is then applied to the alanine dipeptide in vacuum, and to the α-helix ↔ β-sheet transition in a 16-residue peptide modeled in implicit solvent. The SCM requires less effort for the calculation of free energy differences than previous formulations because it does not require computing normal modes. The SCM has a diminished advantage for determining absolute free energy values, because it requires decreasing the MD integration step to obtain accurate results. An approximate confinement procedure is introduced, which can be used to estimate directly the configurational entropy difference between two macrostates, without the need for additional computation of the difference in the free energy or enthalpy. The approximation has convergence properties similar to those of the standard confinement method for the calculation of free energies. The use of the approximation requires about 5 times less wall-clock simulation time than that needed to compute enthalpy differences to similar precision from an MD trajectory. For the biomolecular systems considered in this study, the errors in the entropy approximation are under 10%. Practical applications of the methods to proteins are currently limited to implicit solvent simulations. PMID:23268557

  14. OSSOS. II. A Sharp Transition in the Absolute Magnitude Distribution of the Kuiper Belt’s Scattering Population

    NASA Astrophysics Data System (ADS)

    Shankman, C.; Kavelaars, JJ.; Gladman, B. J.; Alexandersen, M.; Kaib, N.; Petit, J.-M.; Bannister, M. T.; Chen, Y.-T.; Gwyn, S.; Jakubik, M.; Volk, K.

    2016-02-01

    We measure the absolute magnitude, H, distribution, dN(H) ∝ 10αH, of the scattering Trans-Neptunian Objects (TNOs) as a proxy for their size-frequency distribution. We show that the H-distribution of the scattering TNOs is not consistent with a single-slope distribution, but must transition around Hg ˜ 9 to either a knee with a shallow slope or to a divot, which is a differential drop followed by second exponential distribution. Our analysis is based on a sample of 22 scattering TNOs drawn from three different TNO surveys—the Canada-France Ecliptic Plane Survey, Alexandersen et al., and the Outer Solar System Origins Survey, all of which provide well-characterized detection thresholds—combined with a cosmogonic model for the formation of the scattering TNO population. Our measured absolute magnitude distribution result is independent of the choice of cosmogonic model. Based on our analysis, we estimate that the number of scattering TNOs is (2.4-8.3) × 105 for Hr < 12. A divot H-distribution is seen in a variety of formation scenarios and may explain several puzzles in Kuiper Belt science. We find that a divot H-distribution simultaneously explains the observed scattering TNO, Neptune Trojan, Plutino, and Centaur H-distributions while simultaneously predicting a large enough scattering TNO population to act as the sole supply of the Jupiter-Family Comets.

  15. Absolute (γ,p0) and (γ,p1) cross sections and angular distributions for the light, deformed nucleus 19F

    NASA Astrophysics Data System (ADS)

    Kerkhove, E.; Ferdinande, H.; van de Vyver, R.; Berkvens, P.; van Otten, P.; van Camp, E.; Ryckbosch, D.

    1984-06-01

    Absolute (γ,p0) and (γ,p1) differential cross sections for 19F have been measured at seven angles in the energy interval between 13.4 and 25.8 MeV. A sum of Legendre polynomials was fitted to the angular distributions to deduce the angular distribution coefficients. The (γ,p0) and (γ,p1) cross sections have a similar magnitude and represent a minor fraction of the total photoproton channel. The global difference between the two cross sections is attributed to configurational splitting effects. From the (γ,p0) angular distribution coefficients, an E2 cross section was estimated, contributing about 37% to the total E2 energy-weighted sum rule.

  16. Absolute pulse energy measurements of soft x-rays at the Linac Coherent Light Source.

    PubMed

    Tiedtke, K; Sorokin, A A; Jastrow, U; Juranić, P; Kreis, S; Gerken, N; Richter, M; Arp, U; Feng, Y; Nordlund, D; Soufli, R; Fernández-Perea, M; Juha, L; Heimann, P; Nagler, B; Lee, H J; Mack, S; Cammarata, M; Krupin, O; Messerschmidt, M; Holmes, M; Rowen, M; Schlotter, W; Moeller, S; Turner, J J

    2014-09-01

    This paper reports novel measurements of x-ray optical radiation on an absolute scale from the intense and ultra-short radiation generated in the soft x-ray regime of a free electron laser. We give a brief description of the detection principle for radiation measurements which was specifically adapted for this photon energy range. We present data characterizing the soft x-ray instrument at the Linac Coherent Light Source (LCLS) with respect to the radiant power output and transmission by using an absolute detector temporarily placed at the downstream end of the instrument. This provides an estimation of the reflectivity of all x-ray optical elements in the beamline and provides the absolute photon number per bandwidth per pulse. This parameter is important for many experiments that need to understand the trade-offs between high energy resolution and high flux, such as experiments focused on studying materials via resonant processes. Furthermore, the results are compared with the LCLS diagnostic gas detectors to test the limits of linearity, and observations are reported on radiation contamination from spontaneous undulator radiation and higher harmonic content. PMID:25321502

  17. A new absolute method for the standardization of radionuclides emitting low-energy radiation.

    PubMed

    Leblanc, E; de, Marcillac P; Coron, N; Leblanc, J; Loidl, M; Metge, J F; Bouchard, J

    2002-01-01

    Microcalorimeters (or bolometers) operated at temperatures below 100 mK allow individual counting of photons and electrons with a very low energy detection threshold. The physics is based on the pulse temperature increase of the target (or absorber) of the detector due to the complete absorption of both electrons and photons. Since this target can be constructed with a perfect 4-pi geometry, a bolometer offers potentially a new method for absolute activity measurements of radionuclides emitting low-energy radiation. In this paper we present our first results of a feasibility study of activity standardization of a 55Fe solution with a prototype 4-pi bolometer. PMID:11839023

  18. Electro-optic measurement of terahertz pulse energy distribution

    NASA Astrophysics Data System (ADS)

    Sun, J. H.; Gallacher, J. G.; Brussaard, G. J. H.; Lemos, N.; Issac, R.; Huang, Z. X.; Dias, J. M.; Jaroszynski, D. A.

    2009-11-01

    An accurate and direct measurement of the energy distribution of a low repetition rate terahertz electromagnetic pulse is challenging because of the lack of sensitive detectors in this spectral range. In this paper, we show how the total energy and energy density distribution of a terahertz electromagnetic pulse can be determined by directly measuring the absolute electric field amplitude and beam energy density distribution using electro-optic detection. This method has potential use as a routine method of measuring the energy density of terahertz pulses that could be applied to evaluating future high power terahertz sources, terahertz imaging, and spatially and temporarily resolved pump-probe experiments.

  19. On the energy distribution in Sirius B

    NASA Technical Reports Server (NTRS)

    Boehm-Vitense, E.; Dettmann, T.; Kapranidis, S.

    1979-01-01

    A spectrum of Sirius B in the wavelength region 1100-1900 A taken with the IUE satellite shows an absolute flux and spectral energy distribution in the continuum in agreement with theoretical white-dwarf models with T(eff) of 26,000 K plus or minus 1000 K for log g equals 8.65 and R equals 5.08 x 10 to the 8th cm. The Lyman-alpha profile is also in agreement with these parameters. No obvious emission lines in the spectrum of Sirius B or A which could indicate the presence of a chromosphere or corona in either of the stars are observed.

  20. Easy Absolute Values? Absolutely

    ERIC Educational Resources Information Center

    Taylor, Sharon E.; Mittag, Kathleen Cage

    2015-01-01

    The authors teach a problem-solving course for preservice middle-grades education majors that includes concepts dealing with absolute-value computations, equations, and inequalities. Many of these students like mathematics and plan to teach it, so they are adept at symbolic manipulations. Getting them to think differently about a concept that they…

  1. Evaluation of Generalized Born Model Accuracy for Absolute Binding Free Energy Calculations.

    PubMed

    Zeller, Fabian; Zacharias, Martin

    2014-06-27

    Generalized Born (GB) implicit solvent models are widely used in molecular dynamics simulations to evaluate the interactions of biomolecular complexes. The continuum treatment of the solvent results in significant computational savings in comparison to an explicit solvent representation. It is, however, not clear how accurately the GB approach reproduces the absolute free energies of biomolecular binding. On the basis of induced dissociation by means of umbrella sampling simulations, the absolute binding free energies of small proline-rich peptide ligands and a protein receptor were calculated. Comparative simulations according to the same protocol were performed by employing an explicit solvent model and various GB-type implicit solvent models in combination with a nonpolar surface tension term. The peptide ligands differed in a key residue at the peptide-protein interface, including either a nonpolar, a neutral polar, a positively charged, or a negatively charged group. For the peptides with a neutral polar or nonpolar interface residue, very good agreement between the explicit solvent and GB implicit solvent results was found. Deviations in the main separation free energy contributions are smaller than 1 kcal/mol. In contrast, for peptides with a charged interface residue, significant deviations of 2-4 kcal/mol were observed. The results indicate that recent GB models can compete with explicit solvent representations in total binding free energy calculations as long as no charged residues are present at the binding interface. PMID:24941018

  2. Absolute Hydration Free Energies of Blocked Amino Acids: Implications for Protein Solvation and Stability

    PubMed Central

    König, Gerhard; Bruckner, Stefan; Boresch, Stefan

    2013-01-01

    Most proteins perform their function in aqueous solution. The interactions with water determine the stability of proteins and the desolvation costs of ligand binding or membrane insertion. However, because of experimental restrictions, absolute solvation free energies of proteins or amino acids are not available. Instead, solvation free energies are estimated based on side chain analog data. This approach implies that the contributions to free energy differences are additive, and it has often been employed for estimating folding or binding free energies. However, it is not clear how much the additivity assumption affects the reliability of the resulting data. Here, we use molecular dynamics–based free energy simulations to calculate absolute hydration free energies for 15 N-acetyl-methylamide amino acids with neutral side chains. By comparing our results with solvation free energies for side chain analogs, we demonstrate that estimates of solvation free energies of full amino acids based on group-additive methods are systematically too negative and completely overestimate the hydrophobicity of glycine. The largest deviation of additive protocols using side chain analog data was 6.7 kcal/mol; on average, the deviation was 4 kcal/mol. We briefly discuss a simple way to alleviate the errors incurred by using side chain analog data and point out the implications of our findings for the field of biophysics and implicit solvent models. To support our results and conclusions, we calculate relative protein stabilities for selected point mutations, yielding a root-mean-square deviation from experimental results of 0.8 kcal/mol. PMID:23442867

  3. Absolute polarimeter for the proton-beam energy of 200 MeV

    SciTech Connect

    Zelenski, A. N.; Atoian, G.; Bogdanov, A. A.; Nurushev, S. B.; Pylaev, F. S.; Raparia, D.; Runtso, M. F.; Stephenson, E.

    2013-12-15

    A polarimeter is upgraded and tested in a 200-MeV polarized-proton beam at the accelerator-collider facility of the Brookhaven National Laboratory. The polarimeter is based on the elastic polarizedproton scattering on a carbon target at an angle of 16.2°, in which case the analyzing power is close to unity and was measured to a very high degree of precision. It is shown that, in the energy range of 190–205 MeV, the absolute polarization can be measured to a precision better than ±0.5%.

  4. Computations of absolute solvation free energies of small molecules using explicit and implicit solvent model.

    SciTech Connect

    Shivakumar, D.; Deng, Y.; Roux, B.; Biosciences Division; Univ. of Chicago

    2009-01-01

    Accurate determination of absolute solvation free energy plays a critical role in numerous areas of biomolecular modeling and drug discovery. A quantitative representation of ligand and receptor desolvation, in particular, is an essential component of current docking and scoring methods. Furthermore, the partitioning of a drug between aqueous and nonpolar solvents is one of the important factors considered in pharmacokinetics. In this study, the absolute hydration free energy for a set of 239 neutral ligands spanning diverse chemical functional groups commonly found in drugs and drug-like candidates is calculated using the molecular dynamics free energy perturbation method (FEP/MD) with explicit water molecules, and compared to experimental data as well as its counterparts obtained using implicit solvent models. The hydration free energies are calculated from explicit solvent simulations using a staged FEP procedure permitting a separation of the total free energy into polar and nonpolar contributions. The nonpolar component is further decomposed into attractive (dispersive) and repulsive (cavity) components using the Weeks-Chandler-Anderson (WCA) separation scheme. To increase the computational efficiency, all of the FEP/MD simulations are generated using a mixed explicit/implicit solvent scheme with a relatively small number of explicit TIP3P water molecules, in which the influence of the remaining bulk is incorporated via the spherical solvent boundary potential (SSBP). The performances of two fixed-charge force fields designed for small organic molecules, the General Amber force field (GAFF), and the all-atom CHARMm-MSI, are compared. Because of the crucial role of electrostatics in solvation free energy, the results from various commonly used charge generation models based on the semiempirical (AM1-BCC) and QM calculations [charge fitting using ChelpG and RESP] are compared. In addition, the solvation free energies of the test set are also calculated using

  5. Probing carbohydrate product expulsion from a processive cellulase with multiple absolute binding free energy methods.

    PubMed

    Bu, Lintao; Beckham, Gregg T; Shirts, Michael R; Nimlos, Mark R; Adney, William S; Himmel, Michael E; Crowley, Michael F

    2011-05-20

    Understanding the enzymatic mechanism that cellulases employ to degrade cellulose is critical to efforts to efficiently utilize plant biomass as a sustainable energy resource. A key component of cellulase action on cellulose is product inhibition from monosaccharide and disaccharides in the product site of cellulase tunnel. The absolute binding free energy of cellobiose and glucose to the product site of the catalytic tunnel of the Family 7 cellobiohydrolase (Cel7A) of Trichoderma reesei (Hypocrea jecorina) was calculated using two different approaches: steered molecular dynamics (SMD) simulations and alchemical free energy perturbation molecular dynamics (FEP/MD) simulations. For the SMD approach, three methods based on Jarzynski's equality were used to construct the potential of mean force from multiple pulling trajectories. The calculated binding free energies, -14.4 kcal/mol using SMD and -11.2 kcal/mol using FEP/MD, are in good qualitative agreement. Analysis of the SMD pulling trajectories suggests that several protein residues (Arg-251, Asp-259, Asp-262, Trp-376, and Tyr-381) play key roles in cellobiose and glucose binding to the catalytic tunnel. Five mutations (R251A, D259A, D262A, W376A, and Y381A) were made computationally to measure the changes in free energy during the product expulsion process. The absolute binding free energies of cellobiose to the catalytic tunnel of these five mutants are -13.1, -6.0, -11.5, -7.5, and -8.8 kcal/mol, respectively. The results demonstrated that all of the mutants tested can lower the binding free energy of cellobiose, which provides potential applications in engineering the enzyme to accelerate the product expulsion process and improve the efficiency of biomass conversion. PMID:21454590

  6. Distributed Wind Energy in Idaho

    SciTech Connect

    Gardner, John; Johnson, Kathryn; Haynes, Todd; Seifert, Gary

    2009-01-31

    This project is a research and development program aimed at furthering distributed wind technology. In particular, this project addresses some of the barriers to distributed wind energy utilization in Idaho.

  7. Absolute Binding Free Energy Calculations Using Molecular Dynamics Simulations with Restraining Potentials

    PubMed Central

    Wang, Jiyao; Deng, Yuqing; Roux, Benoît

    2006-01-01

    The absolute (standard) binding free energy of eight FK506-related ligands to FKBP12 is calculated using free energy perturbation molecular dynamics (FEP/MD) simulations with explicit solvent. A number of features are implemented to improve the accuracy and enhance the convergence of the calculations. First, the absolute binding free energy is decomposed into sequential steps during which the ligand-surrounding interactions as well as various biasing potentials restraining the translation, orientation, and conformation of the ligand are turned “on” and “off.” Second, sampling of the ligand conformation is enforced by a restraining potential based on the root mean-square deviation relative to the bound state conformation. The effect of all the restraining potentials is rigorously unbiased, and it is shown explicitly that the final results are independent of all artificial restraints. Third, the repulsive and dispersive free energy contribution arising from the Lennard-Jones interactions of the ligand with its surrounding (protein and solvent) is calculated using the Weeks-Chandler-Andersen separation. This separation also improves convergence of the FEP/MD calculations. Fourth, to decrease the computational cost, only a small number of atoms in the vicinity of the binding site are simulated explicitly, while all the influence of the remaining atoms is incorporated implicitly using the generalized solvent boundary potential (GSBP) method. With GSBP, the size of the simulated FKBP12/ligand systems is significantly reduced, from ∼25,000 to 2500. The computations are very efficient and the statistical error is small (∼1 kcal/mol). The calculated binding free energies are generally in good agreement with available experimental data and previous calculations (within ∼2 kcal/mol). The present results indicate that a strategy based on FEP/MD simulations of a reduced GSBP atomic model sampled with conformational, translational, and orientational restraining

  8. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2012-05-15

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  9. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2010-07-13

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  10. Radar prediction of absolute rain fade distributions for earth-satellite paths and general methods for extrapolation of fade statistics to other locations

    NASA Technical Reports Server (NTRS)

    Goldhirsh, J.

    1982-01-01

    The first absolute rain fade distribution method described establishes absolute fade statistics at a given site by means of a sampled radar data base. The second method extrapolates absolute fade statistics from one location to another, given simultaneously measured fade and rain rate statistics at the former. Both methods employ similar conditional fade statistic concepts and long term rain rate distributions. Probability deviations in the 2-19% range, with an 11% average, were obtained upon comparison of measured and predicted levels at given attenuations. The extrapolation of fade distributions to other locations at 28 GHz showed very good agreement with measured data at three sites located in the continental temperate region.

  11. ABSOLUTE MEASUREMENT OF THE POLARIZATION OF HIGH ENERGY PROTON BEAMS AT RHIC

    SciTech Connect

    MAKDISI,Y.; BRAVAR, A. BUNCE, G. GILL, R.; HUANG, H.; ET AL.

    2007-06-25

    The spin physics program at the Relativistic Heavy Ion Collider (RHIC) requires knowledge of the beam polarization to better than 5%. Such a goal is made the more difficult by the lack of knowledge of the analyzing power of high energy nuclear physics processes. To overcome this, a polarized hydrogen jet target was constructed and installed at one intersection region in RHIC where it intersects both beams and utilizes the precise knowledge of the jet atomic hydrogen beam polarization to measure the analyzing power in proton-proton elastic scattering in the Nuclear Coulomb Interference (CNI) region at the prescribed RHIC proton beam energy. The reverse reaction is used to assess the absolute beam polarization. Simultaneous measurements taken with fast high statistics polarimeters that measure the p-Carbon elastic scattering process also in the CNI region use the jet results to calibrate the latter.

  12. Determination of RW3-to-water mass-energy absorption coefficient ratio for absolute dosimetry.

    PubMed

    Seet, Katrina Y T; Hanlon, Peta M; Charles, Paul H

    2011-12-01

    The measurement of absorbed dose to water in a solid-phantom may require a conversion factor because it may not be radiologically equivalent to water. One phantom developed for the use of dosimetry is a solid water, RW3 white-polystyrene material by IBA. This has a lower mass-energy absorption coefficient than water due to high bremsstrahlung yield, which affects the accuracy of absolute dosimetry measurements. In this paper, we demonstrate the calculation of mass-energy absorption coefficient ratios, relative to water, from measurements in plastic water and RW3 with an Elekta Synergy linear accelerator (6 and 10 MV photon beams) as well as Monte Carlo modeling in BEAMnrc and DOSXYZnrc. From this, the solid-phantom-to-water correction factor was determined for plastic water and RW3. PMID:21960410

  13. Fast GPU-based absolute intensity determination for energy-dispersive X-ray Laue diffraction

    NASA Astrophysics Data System (ADS)

    Alghabi, F.; Send, S.; Schipper, U.; Abboud, A.; Pietsch, U.; Kolb, A.

    2016-01-01

    This paper presents a novel method for fast determination of absolute intensities in the sites of Laue spots generated by a tetragonal hen egg-white lysozyme crystal after exposure to white synchrotron radiation during an energy-dispersive X-ray Laue diffraction experiment. The Laue spots are taken by means of an energy-dispersive X-ray 2D pnCCD detector. Current pnCCD detectors have a spatial resolution of 384 × 384 pixels of size 75 × 75 μm2 each and operate at a maximum of 400 Hz. Future devices are going to have higher spatial resolution and frame rates. The proposed method runs on a computer equipped with multiple Graphics Processing Units (GPUs) which provide fast and parallel processing capabilities. Accordingly, our GPU-based algorithm exploits these capabilities to further analyse the Laue spots of the sample. The main contribution of the paper is therefore an alternative algorithm for determining absolute intensities of Laue spots which are themselves computed from a sequence of pnCCD frames. Moreover, a new method for integrating spectral peak intensities and improved background correction, a different way of calculating mean count rate of the background signal and also a new method for n-dimensional Poisson fitting are presented.We present a comparison of the quality of results from the GPU-based algorithm with the quality of results from a prior (base) algorithm running on CPU. This comparison shows that our algorithm is able to produce results with at least the same quality as the base algorithm. Furthermore, the GPU-based algorithm is able to speed up one of the most time-consuming parts of the base algorithm, which is n-dimensional Poisson fitting, by a factor of more than 3. Also, the entire procedure of extracting Laue spots' positions, energies and absolute intensities from a raw dataset of pnCCD frames is accelerated by a factor of more than 3.

  14. Absolute energy calibration for relativistic electron beams with pointing instability from a laser-plasma accelerator

    SciTech Connect

    Cha, H. J.; Choi, I. W.; Kim, H. T.; Kim, I J.; Nam, K. H.; Jeong, T. M.; Lee, J.

    2012-06-15

    The pointing instability of energetic electron beams generated from a laser-driven accelerator can cause a serious error in measuring the electron spectrum with a magnetic spectrometer. In order to determine a correct electron spectrum, the pointing angle of an electron beam incident on the spectrometer should be exactly defined. Here, we present a method for absolutely calibrating the electron spectrum by monitoring the pointing angle using a scintillating screen installed in front of a permanent dipole magnet. The ambiguous electron energy due to the pointing instability is corrected by the numerical and analytical calculations based on the relativistic equation of electron motion. It is also possible to estimate the energy spread of the electron beam and determine the energy resolution of the spectrometer using the beam divergence angle that is simultaneously measured on the screen. The calibration method with direct measurement of the spatial profile of an incident electron beam has a simple experimental layout and presents the full range of spatial and spectral information of the electron beams with energies of multi-hundred MeV level, despite the limited energy resolution of the simple electron spectrometer.

  15. Measurement of absolute optical thickness distribution of a mask-glass by wavelength tuning interferometry

    NASA Astrophysics Data System (ADS)

    Hibino, Kenichi; Yangjin, Kim; Bitou, Youichi; Ohsawa, Sonko; Sugita, Naohiko; Mitsuishi, Mamoru

    2008-08-01

    The surface flatness and the uniformity in thickness and refractive index of a mask-blank glass have been requested in semiconductor industry. The absolute optical thickness of a mask-blank glass of seven-inch square and 3mm thickness was measured by three-surface interferometry in a wavelength tuning Fizeau interferometer. Wavelength-tuning interferometry can separate in frequency space the three interference signals of the surface shape and the optical thickness. The wavelength of a tunable laser diode source was scanned linearly from 632 nm to 642 nm and a CCD detector recorded two thousand interference images. The number of phase variation of the interference fringes during the wavelength scanning was counted by a temporal discrete Fourier transform. The initial and final phases of the interferograms before and after the scanning were measured by a phase shifting technique with fine tunings of the wavelengths at 632 nm and 642 nm. The optical thickness defined by the group refractive index at the central wavelength of 337 nm can be measured by this technique. Experimental results show that the cross talk in multiple-surface interferometry caused a systematic error of 2.0 microns in the measured optical thickness.

  16. Quantitative atomic resolution elemental mapping via absolute-scale energy dispersive X-ray spectroscopy.

    PubMed

    Chen, Z; Weyland, M; Sang, X; Xu, W; Dycus, J H; LeBeau, J M; D'Alfonso, A J; Allen, L J; Findlay, S D

    2016-09-01

    Quantitative agreement on an absolute scale is demonstrated between experiment and simulation for two-dimensional, atomic-resolution elemental mapping via energy dispersive X-ray spectroscopy. This requires all experimental parameters to be carefully characterized. The agreement is good, but some discrepancies remain. The most likely contributing factors are identified and discussed. Previous predictions that increasing the probe forming aperture helps to suppress the channelling enhancement in the average signal are confirmed experimentally. It is emphasized that simple column-by-column analysis requires a choice of sample thickness that compromises between being thick enough to yield a good signal-to-noise ratio while being thin enough that the overwhelming majority of the EDX signal derives from the column on which the probe is placed, despite strong electron scattering effects. PMID:27258645

  17. Superharp — A wire scanner with absolute position readout for beam energy measurement at CEBAF

    NASA Astrophysics Data System (ADS)

    Yan, C.; Adderley, P.; Barker, D.; Beaufait, J.; Capek, K.; Carlini, R.; Dahlberg, J.; Feldl, E.; Jordan, K.; Kross, B.; Oren, W.; Wojcik, R.; VanDyke, J.

    1995-02-01

    The CEBAF superharp is an upgraded beam wire scanner which provides absolute beam position readout using a shaft encoder. Superharps allow for high precision measurements of the beam's profile and position ( Δx ˜ 10 μm). The Hall C endstation at CEBAF will use three pairs of superharps to perform beam energy measurements with 10 -3 accuracy. The three pairs are installed at the beginning, the mid-point and the end of the Hall C arc beamline. Using superharps in conjunction with a dual sensor system: the direct current pick-up and the bremsstrahlung detectors, beam profile measurements can be obtained over a wide beam current range of 1 ˜ 200 μA.

  18. In-Flight Measurement of the Absolute Energy Scale of the Fermi Large Area Telescope

    SciTech Connect

    Ackermann, M.; Ajello, M.; Allafort, A.; Atwood, W.B.; Axelsson, M.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bloom, E.D.; Bonamente, E.; Borgland, A.W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; /more authors..

    2012-09-20

    The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to survey the gamma-ray sky from 20 MeV to several hundreds of GeV. In this energy band there are no astronomical sources with sufficiently well known and sharp spectral features to allow an absolute calibration of the LAT energy scale. However, the geomagnetic cutoff in the cosmic ray electron-plus-positron (CRE) spectrum in low Earth orbit does provide such a spectral feature. The energy and spectral shape of this cutoff can be calculated with the aid of a numerical code tracing charged particles in the Earth's magnetic field. By comparing the cutoff value with that measured by the LAT in different geomagnetic positions, we have obtained several calibration points between {approx}6 and {approx}13 GeV with an estimated uncertainty of {approx}2%. An energy calibration with such high accuracy reduces the systematic uncertainty in LAT measurements of, for example, the spectral cutoff in the emission from gamma ray pulsars.

  19. In-Flight Measurement of the Absolute Energy Scale of the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Ackermann, M.; Ajello, M.; Allafort, A.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Barbielini, G; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B,; Bloom, E. D.; Bonamente, E.; Borgland, A. W.; Bouvier, A.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Buehler, R.; Gehrels, N.; Hays, E.; McEnery, J. E.; Thompson, D. J.; Troja, E. J.

    2012-01-01

    The Large Area Telescope (LAT) on-board the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to survey the gamma-ray sky from 20 MeV to several hundreds of GeV. In this energy band there are no astronomical sources with sufficiently well known and sharp spectral features to allow an absolute calibration of the LAT energy scale. However, the geomagnetic cutoff in the cosmic ray electron- plus-positron (CRE) spectrum in low Earth orbit does provide such a spectral feature. The energy and spectral shape of this cutoff can be calculated with the aid of a numerical code tracing charged particles in the Earth's magnetic field. By comparing the cutoff value with that measured by the LAT in different geomagnetic positions, we have obtained several calibration points between approx. 6 and approx. 13 GeV with an estimated uncertainty of approx. 2%. An energy calibration with such high accuracy reduces the systematic uncertainty in LAT measurements of, for example, the spectral cutoff in the emission from gamma ray pulsars.

  20. Setting Whole-Building Absolute Energy Use Targets for the K-12 School, Retail, and Healthcare Sectors: Preprint

    SciTech Connect

    Leach, M.; Bonnema, E.; Pless, S.; Torcellini, P.

    2012-08-01

    This paper helps owners' efficiency representatives to inform executive management, contract development, and project management staff as to how specifying and applying whole-building absolute energy use targets for new construction or renovation projects can improve the operational energy performance of commercial buildings.

  1. Surveying implicit solvent models for estimating small molecule absolute hydration free energies

    PubMed Central

    Knight, Jennifer L.

    2011-01-01

    Implicit solvent models are powerful tools in accounting for the aqueous environment at a fraction of the computational expense of explicit solvent representations. Here, we compare the ability of common implicit solvent models (TC, OBC, OBC2, GBMV, GBMV2, GBSW, GBSW/MS, GBSW/MS2 and FACTS) to reproduce experimental absolute hydration free energies for a series of 499 small neutral molecules that are modeled using AMBER/GAFF parameters and AM1-BCC charges. Given optimized surface tension coefficients for scaling the surface area term in the nonpolar contribution, most implicit solvent models demonstrate reasonable agreement with extensive explicit solvent simulations (average difference 1.0-1.7 kcal/mol and R2=0.81-0.91) and with experimental hydration free energies (average unsigned errors=1.1-1.4 kcal/mol and R2=0.66-0.81). Chemical classes of compounds are identified that need further optimization of their ligand force field parameters and others that require improvement in the physical parameters of the implicit solvent models themselves. More sophisticated nonpolar models are also likely necessary to more effectively represent the underlying physics of solvation and take the quality of hydration free energies estimated from implicit solvent models to the next level. PMID:21735452

  2. A rare gas optics-free absolute photon flux and energy analyzer to provide absolute photoionization rates of inflowing interstellar neutrals

    NASA Technical Reports Server (NTRS)

    Judge, Darrell L.

    1994-01-01

    A prototype spectrometer has been developed for space applications requiring long term absolute EUV photon flux measurements. The energy spectrum of the incoming photons is transformed directly into an electron energy spectrum by taking advantage of the photoelectric effect in one of several rare gases at low pressures. Using an electron energy spectrometer, followed by an electron multiplier detector, pulses due to individual electrons are counted. The overall efficiency of this process can be made essentially independent of gain drifts in the signal path, and the secular degradation of optical components which is often a problem in other techniques is avoided. A very important feature of this approach is its freedom from the problem of overlapping spectral orders that plagues grating EUV spectrometers. An instrument with these features has not been flown before, but is essential to further advances in our understanding of solar EUV flux dynamics, and the coupled dynamics of terrestrial and planetary atmospheres. The detailed characteristics of this optics-free spectrometer are presented in the publications section.

  3. Direct detection of neutral metal atoms in electron-stimulated desorption: Al from CH{sub 3}O/Al(111) - velocity distribution and absolute yield

    SciTech Connect

    Whitten, J.E.; Young, C.E.; Pellin, M.J.; Gruen, D.M.; Jones, P.L.

    1994-06-01

    Electron-stimulated desorption of neutral aluminum from the system CH{sub 3}O/Al(111) has been directly monitored via quasiresonant photoionization with 193 nm excimer laser light and confirmed by two-step resonant ionization, utilizing the Al 3d {sup 2}D manifold. Velocity distribution measurements for the neutral Al peak at {approximately} 800 m/s for 1 keV incident electron energy. An absolute yield of 3.2 x 10{sup {minus}6} Al atoms/electron was determined by comparison with sputtering measurements in the same apparatus. This is the first observation of electron-stimulated metal desorption from adsorbate-covered metallic surfaces.

  4. Free Energy Perturbation Hamiltonian Replica-Exchange Molecular Dynamics (FEP\\H-REMD) for absolute ligand binding free energy calculations.

    SciTech Connect

    Jiang, W.; Roux, B.

    2010-09-01

    Free Energy Perturbation with Replica Exchange Molecular Dynamics (FEP/REMD) offers a powerful strategy to improve the convergence of free energy computations. In particular, it has been shown previously that a FEP/REMD scheme allowing random moves within an extended replica ensemble of thermodynamic coupling parameters '{lambda}' can improve the statistical convergence in calculations of absolute binding free energy of ligands to proteins [J. Chem. Theory Comput. 2009, 5, 2583]. In the present study, FEP/REMD is extended and combined with an accelerated MD simulations method based on Hamiltonian replica-exchange MD (H-REMD) to overcome the additional problems arising from the existence of kinetically trapped conformations within the protein receptor. In the combined strategy, each system with a given thermodynamic coupling factor {lambda} in the extended ensemble is further coupled with a set of replicas evolving on a biased energy surface with boosting potentials used to accelerate the interconversion among different rotameric states of the side chains in the neighborhood of the binding site. Exchanges are allowed to occur alternatively along the axes corresponding to the thermodynamic coupling parameter {lambda} and the boosting potential, in an extended dual array of coupled {lambda}- and H-REMD simulations. The method is implemented on the basis of new extensions to the REPDSTR module of the biomolecular simulation program CHARMM. As an illustrative example, the absolute binding free energy of p-xylene to the nonpolar cavity of the L99A mutant of the T4 lysozyme was calculated. The tests demonstrate that the dual {lambda}-REMD and H-REMD simulation scheme greatly accelerates the configurational sampling of the rotameric states of the side chains around the binding pocket, thereby improving the convergence of the FEP computations.

  5. Absolute Entropy and Energy of Carbon Dioxide Using the Two-Phase Thermodynamic Model.

    PubMed

    Huang, Shao-Nung; Pascal, Tod A; Goddard, William A; Maiti, Prabal K; Lin, Shiang-Tai

    2011-06-14

    The two-phase thermodynamic (2PT) model is used to determine the absolute entropy and energy of carbon dioxide over a wide range of conditions from molecular dynamics trajectories. The 2PT method determines the thermodynamic properties by applying the proper statistical mechanical partition function to the normal modes of a fluid. The vibrational density of state (DoS), obtained from the Fourier transform of the velocity autocorrelation function, converges quickly, allowing the free energy, entropy, and other thermodynamic properties to be determined from short 20-ps MD trajectories. The anharmonic effects in the vibrations are accounted for by the broadening of the normal modes into bands from sampling the velocities over the trajectory. The low frequency diffusive modes, which lead to finite DoS at zero frequency, are accounted for by considering the DoS as a superposition of gas-phase and solid-phase components (two phases). The analytical decomposition of the DoS allows for an evaluation of properties contributed by different types of molecular motions. We show that this 2PT analysis leads to accurate predictions of entropy and energy of CO2 over a wide range of conditions (from the triple point to the critical point of both the vapor and the liquid phases along the saturation line). This allows the equation of state of CO2 to be determined, which is limited only by the accuracy of the force field. We also validated that the 2PT entropy agrees with that determined from thermodynamic integration, but 2PT requires only a fraction of the time. A complication for CO2 is that its equilibrium configuration is linear, which would have only two rotational modes, but during the dynamics it is never exactly linear, so that there is a third mode from rotational about the axis. In this work, we show how to treat such linear molecules in the 2PT framework. PMID:26596450

  6. Calculation of the absolute free energy of a smectic-A phase

    NASA Astrophysics Data System (ADS)

    Huang, Chien-Cheng; Ramachandran, Sanoop; Ryckaert, Jean-Paul

    2014-12-01

    In this paper, we provide a scheme to compute the absolute free energy of a smectic-A phase via the "indirect method." The state of interest is connected through a three-step reversible path to a reference state. This state consists of a low-density layer of rods coupled to two external fields maintaining these rods close to the layer's plane and oriented preferably normal to the layer. The low-density free energy of the reference state can be computed on the basis of the relevant second virial coefficients between two rods coupled to the two external fields. We apply this technique to the Gay-Berne potential for calamitics with a parameter set leading to stable isotropic (I), nematic (N), smectic-A (SmA), and crystal (Cr) phases. We locate the I-SmA phase transition at low pressure and the sequence of phase transitions I-N-SmA along higher-pressure isobars and we establish the location of the I-N-SmA triple point. Close to this triple point, we show that the N-SmA transition is clearly first order. Our results are compared to the coexistence lines of the approximate phase diagram elucidated by de Miguel et al. [J. Chem. Phys. 121, 11183 (2004), 10.1063/1.1810472] established through the direct observation of the sequence of phase transitions occurring along isobars under heating or cooling sequences of runs. Finally, we discuss the potential of our technique in studying similar transitions observed on layered phases under confinement.

  7. Calculation of the absolute free energy of a smectic-A phase.

    PubMed

    Huang, Chien-Cheng; Ramachandran, Sanoop; Ryckaert, Jean-Paul

    2014-12-01

    In this paper, we provide a scheme to compute the absolute free energy of a smectic-A phase via the "indirect method." The state of interest is connected through a three-step reversible path to a reference state. This state consists of a low-density layer of rods coupled to two external fields maintaining these rods close to the layer's plane and oriented preferably normal to the layer. The low-density free energy of the reference state can be computed on the basis of the relevant second virial coefficients between two rods coupled to the two external fields. We apply this technique to the Gay-Berne potential for calamitics with a parameter set leading to stable isotropic (I), nematic (N), smectic-A (SmA), and crystal (Cr) phases. We locate the I-SmA phase transition at low pressure and the sequence of phase transitions I-N-SmA along higher-pressure isobars and we establish the location of the I-N-SmA triple point. Close to this triple point, we show that the N-SmA transition is clearly first order. Our results are compared to the coexistence lines of the approximate phase diagram elucidated by de Miguel et al. [J. Chem. Phys. 121, 11183 (2004)] established through the direct observation of the sequence of phase transitions occurring along isobars under heating or cooling sequences of runs. Finally, we discuss the potential of our technique in studying similar transitions observed on layered phases under confinement. PMID:25615118

  8. Absolute Calibration of Image Plate for electrons at energy between 100 keV and 4 MeV

    SciTech Connect

    Chen, H; Back, N L; Eder, D C; Ping, Y; Song, P M; Throop, A

    2007-12-10

    The authors measured the absolute response of image plate (Fuji BAS SR2040) for electrons at energies between 100 keV to 4 MeV using an electron spectrometer. The electron source was produced from a short pulse laser irradiated on the solid density targets. This paper presents the calibration results of image plate Photon Stimulated Luminescence PSL per electrons at this energy range. The Monte Carlo radiation transport code MCNPX results are also presented for three representative incident angles onto the image plates and corresponding electron energies depositions at these angles. These provide a complete set of tools that allows extraction of the absolute calibration to other spectrometer setting at this electron energy range.

  9. Absolute Magnetization Distribution on Back-arc Spreading Axis Hosting Hydrothermal Vents; Insight from Shinkai 6500 Magnetic Survey

    NASA Astrophysics Data System (ADS)

    Fujii, M.; Okino, K.; Honsho, C.; Mochizuki, N.; Szitkar, F.; Dyment, J.

    2013-12-01

    Near-bottom magnetic profiling using submersible, deep-tow, Remotely Operated Vehicle (ROV) and Autonomous Underwater Vehicle (AUV) make possible to conduct high-resolution surveys and depict detailed magnetic features reflecting, for instance, the presence of fresh lavas or hydrothermal alteration, or geomagnetic paleo-intensity variations. We conducted near-bottom three component magnetic measurements onboard submersible Shinkai 6500 in the Southern Mariana Trough, where five active hydrothermal vent fields (Snail, Yamanaka, Archean, Pica, and Urashima sites) have been found in both on- and off-axis areas of the active back-arc spreading center, to detect signals from hydrothermally altered rock and to distinguish old and new submarine lava flows. Fourteen dives were carried out at an altitude of 1-40 m during the R/V Yokosuka YK10-10 and YK10-11 cruises in 2010. We carefully corrected the effect of the induced and permanent magnetizations of the submersible by applying the correction method for the shipboard three-component magnetometer measurement modified for deep-sea measurement, and subtracted the IGRF values from the corrected data to obtain geomagnetic vector anomalies along the dive tracks. We then calculated the synthetic magnetic vector field produced by seafloor, assumed to be uniformly magnetized, using three dimensional forward modeling. Finally, values of the absolute magnetizations were estimated by using a linear transfer function in the Fourier domain from the observed and synthetic magnetic anomalies. The distribution of estimated absolute magnetization generally shows low values around the five hydrothermal vent sites. This result is consistent with the equivalent magnetization distribution obtained from previous AUV survey data. The areas of low magnetization are also consistent with hydrothermal deposits identified in video records. These results suggest that low magnetic signals are due to hydrothermal alteration zones where host rocks are

  10. Absolute cross sections for electronic excitations of cytosine by low energy electron impact

    PubMed Central

    Bazin, M.; Michaud, M.; Sanche, L.

    2013-01-01

    The absolute cross sections (CS) for electronic excitations of cytosine by electron impact between 5 and 18 eV were measured by electron-energy loss (EEL) spectroscopy of the molecule deposited at low coverage on an inert Ar substrate. The lowest EEL features found at 3.55 and 4.02 eV are ascribed to transitions from the ground state to the two lowest triplet 1 3A′(π→π*) and 2 3A′(π→π*) valence states of the molecule. Their energy dependent CS exhibit essentially a common maximum at about 6 eV with a value of 1.84 × 10−17 cm2 for the former and 4.94 × 10−17 cm2 for the latter. In contrast, the CS for the next EEL feature at 4.65 eV, which is ascribed to the optically allowed transition to the 2 1A′(π→π*) valence state, shows only a steep rise to about 1.04 × 10−16 cm2 followed by a monotonous decrease with the incident electron energy. The higher EEL features at 5.39, 6.18, 6.83, and 7.55 eV are assigned to the excitations of the 3 3, 1A′(π→π*), 4 1A′(π→π*), 5 1A′(π→π*), and 6 1A′(π→π*) valence states, respectively. The CS for the 3 3, 1A′ and 4 1A′ states exhibit a common enhancement at about 10 eV superimposed on a more or less a steep rise, reaching respectively a maximum of 1.27 and 1.79 × 10−16 cm2, followed by a monotonous decrease. This latter enhancement and the maximum seen at about 6 eV in the lowest triplet states correspond to the core-excited electron resonances that have been found by dissociative electron attachment experiments with cytosine in the gas phase. The weak EEL feature found at 5.01 eV with a maximum CS of 3.8 × 10−18 cm2 near its excitation threshold is attributed to transitions from the ground state to the 1 3, 1A″(n→π*) states. The monotonous rise of the EEL signal above 8 eV is attributed to the ionization of the molecule. It is partitioned into four excitation energy regions at about 8.55, 9.21, 9.83, and 11.53 eV, which correspond closely to the ionization energies of

  11. Probability distributions of turbulent energy.

    PubMed

    Momeni, Mahdi; Müller, Wolf-Christian

    2008-05-01

    Probability density functions (PDFs) of scale-dependent energy fluctuations, P[deltaE(l)] , are studied in high-resolution direct numerical simulations of Navier-Stokes and incompressible magnetohydrodynamic (MHD) turbulence. MHD flows with and without a strong mean magnetic field are considered. For all three systems it is found that the PDFs of inertial range energy fluctuations exhibit self-similarity and monoscaling in agreement with recent solar-wind measurements [Hnat, Geophys. Res. Lett. 29, 86 (2002)]. Furthermore, the energy PDFs exhibit similarity over all scales of the turbulent system showing no substantial qualitative change of shape as the scale of the fluctuations varies. This is in contrast to the well-known behavior of PDFs of turbulent velocity fluctuations. In all three cases under consideration the P[deltaE(l)] resemble Lévy-type gamma distributions approximately Delta;{-1} exp(-|deltaE|/Delta)|deltaE|;{-gamma} The observed gamma distributions exhibit a scale-dependent width Delta(l) and a system-dependent gamma . The monoscaling property reflects the inertial-range scaling of the Elsässer-field fluctuations due to lacking Galilei invariance of deltaE . The appearance of Lévy distributions is made plausible by a simple model of energy transfer. PMID:18643170

  12. Calculation of absolute free energy of binding for theophylline and its analogs to RNA aptamer using nonequilibrium work values

    NASA Astrophysics Data System (ADS)

    Tanida, Yoshiaki; Ito, Masakatsu; Fujitani, Hideaki

    2007-08-01

    The massively parallel computation of absolute binding free energy with a well-equilibrated system (MP-CAFEE) has been developed [H. Fujitani, Y. Tanida, M. Ito, G. Jayachandran, C.D. Snow, M.R. Shirts, E.J. Sorin, V.S. Pande, J. Chem. Phys. 123 (2005) 084108]. As an application, we perform the binding affinity calculations of six theophylline-related ligands with RNA aptamer. Basically, our method is applicable when using many compute nodes to accelerate simulations, thus a parallel computing system is also developed. To further reduce the computational cost, the adequate non-uniform intervals of coupling constant λ, connecting two equilibrium states, namely bound and unbound, are determined. The absolute binding energies Δ G thus obtained have effective linear relation between the computed and experimental values. If the results of two other different methods are compared, thermodynamic integration (TI) and molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) by the paper of Gouda et al. [H. Gouda, I.D. Kuntz, D.A. Case, P.A. Kollman, Biopolymers 68 (2003) 16], the predictive accuracy of the relative values ΔΔ G is almost comparable to that of TI: the correlation coefficients ( R) obtained are 0.99 (this work), 0.97 (TI), and 0.78 (MM-PBSA). On absolute binding energies meanwhile, a constant energy shift of ˜-7 kcal/mol against the experimental values is evident. To solve this problem, several presumable reasons are investigated.

  13. Enhanced distributed energy resource system

    DOEpatents

    Atcitty, Stanley; Clark, Nancy H.; Boyes, John D.; Ranade, Satishkumar J.

    2007-07-03

    A power transmission system including a direct current power source electrically connected to a conversion device for converting direct current into alternating current, a conversion device connected to a power distribution system through a junction, an energy storage device capable of producing direct current connected to a converter, where the converter, such as an insulated gate bipolar transistor, converts direct current from an energy storage device into alternating current and supplies the current to the junction and subsequently to the power distribution system. A microprocessor controller, connected to a sampling and feedback module and the converter, determines when the current load is higher than a set threshold value, requiring triggering of the converter to supply supplemental current to the power transmission system.

  14. Absolute cross sections for vibrational excitations of cytosine by low energy electron impact

    PubMed Central

    Michaud, M.; Bazin, M.; Sanche, L.

    2013-01-01

    The absolute cross sections (CSs) for vibrational excitations of cytosine by electron impact between 0.5 and 18 eV were measured by electron-energy loss (EEL) spectroscopy of the molecule deposited at monolayer coverage on an inert Ar substrate. The vibrational energies compare to those that have been reported from IR spectroscopy of cytosine isolated in Ar matrix, IR and Raman spectra of poly-crystalline cytosine, and ab initio calculation. The CSs for the various H bending modes at 142 and 160 meV are both rising from their energy threshold up to 1.7 and 2.1 × 10−17 cm2 at about 4 eV, respectively, and then decrease moderately while maintaining some intensity at 18 eV. The latter trend is displayed as well for the CS assigned to the NH2 scissor along with bending of all H at 179 meV. This overall behavior in electron-molecule collision is attributed to direct processes such as the dipole, quadrupole, and polarization contributions, etc. of the interaction of the incident electron with a molecule. The CSs for the ring deformation at 61 meV, the ring deformation with N-H symmetric wag at 77 meV, and the ring deformations with symmetric bending of all H at 119 meV exhibit common enhancement maxima at 1.5, 3.5, and 5.5 eV followed by a broad hump at about 12 eV, which are superimposed on the contribution due to the direct processes. At 3.5 eV, the CS values for the 61-, 77-, and 119-meV modes reach 4.0, 3.0, and 4.5 × 10−17 cm2, respectively. The CS for the C-C and C-O stretches at 202 meV, which dominates in the intermediate EEL region, rises sharply until 1.5 eV, reaches its maximum of 5.7 × 10−17 cm2 at 3.5 eV and then decreases toward 18 eV. The present vibrational enhancements, correspond to the features found around 1.5 and 4.5 eV in electron transmission spectroscopy (ETS) and those lying within 1.5–2.1 eV, 5.2–6.8 eV, and 9.5–10.9 eV range in dissociative electron attachment (DEA) experiments with cytosine in gas phase. While the ETS features

  15. Elucidating the energetics of entropically driven protein-ligand association: calculations of absolute binding free energy and entropy.

    PubMed

    Deng, Nan-jie; Zhang, Peng; Cieplak, Piotr; Lai, Luhua

    2011-10-20

    The binding of proteins and ligands is generally associated with the loss of translational, rotational, and conformational entropy. In many cases, however, the net entropy change due to binding is positive. To develop a deeper understanding of the energetics of entropically driven protein-ligand binding, we calculated the absolute binding free energies and binding entropies for two HIV-1 protease inhibitors Nelfinavir and Amprenavir using the double-decoupling method with molecular dynamics simulations in explicit solvent. For both ligands, the calculated absolute binding free energies are in general agreement with experiments. The statistical error in the computed ΔG(bind) due to convergence problem is estimated to be ≥2 kcal/mol. The decomposition of free energies indicates that, although the binding of Nelfinavir is driven by nonpolar interaction, Amprenavir binding benefits from both nonpolar and electrostatic interactions. The calculated absolute binding entropies show that (1) Nelfinavir binding is driven by large entropy change and (2) the entropy of Amprenavir binding is much less favorable compared with that of Nelfinavir. Both results are consistent with experiments. To obtain qualitative insights into the entropic effects, we decomposed the absolute binding entropy into different contributions based on the temperature dependence of free energies along different legs of the thermodynamic pathway. The results suggest that the favorable entropic contribution to binding is dominated by the ligand desolvation entropy. The entropy gain due to solvent release from binding site appears to be more than offset by the reduction of rotational and vibrational entropies upon binding. PMID:21899337

  16. Elucidating the Energetics of Entropically Driven Protein–Ligand Association: Calculations of Absolute Binding Free Energy and Entropy

    PubMed Central

    Deng, Nan-jie; Zhang, Peng; Cieplak, Piotr; Lai, Luhua

    2014-01-01

    The binding of proteins and ligands is generally associated with the loss of translational, rotational, and conformational entropy. In many cases, however, the net entropy change due to binding is positive. To develop a deeper understanding of the energetics of entropically driven protein–ligand binding, we calculated the absolute binding free energies and binding entropies for two HIV-1 protease inhibitors Nelfinavir and Amprenavir using the double-decoupling method with molecular dynamics simulations in explicit solvent. For both ligands, the calculated absolute binding free energies are in general agreement with experiments. The statistical error in the computed ΔG(bind) due to convergence problem is estimated to be ≥2 kcal/mol. The decomposition of free energies indicates that, although the binding of Nelfinavir is driven by nonpolar interaction, Amprenavir binding benefits from both nonpolar and electrostatic interactions. The calculated absolute binding entropies show that (1) Nelfinavir binding is driven by large entropy change and (2) the entropy of Amprenavir binding is much less favorable compared with that of Nelfinavir. Both results are consistent with experiments. To obtain qualitative insights into the entropic effects, we decomposed the absolute binding entropy into different contributions based on the temperature dependence of free energies along different legs of the thermodynamic pathway. The results suggest that the favorable entropic contribution to binding is dominated by the ligand desolvation entropy. The entropy gain due to solvent release from binding site appears to be more than offset by the reduction of rotational and vibrational entropies upon binding. PMID:21899337

  17. Energy conservation in electric distribution

    SciTech Connect

    Lee, Chong-Jin

    1994-12-31

    This paper discusses the potential for energy and power savings that exist in electric power delivery systems. These savings translate into significant financial and environmental benefits for electricity producers and consumers as well as for society in general. AlliedSignal`s knowledge and perspectives on this topic are the result of discussions with hundreds of utility executives, government officials and other industry experts over the past decade in conjunction with marketing our Amorphous Metal technology for electric distribution transformers. Amorphous metal is a technology developed by AlliedSignal that significantly reduces the energy lost in electric distribution transformers at an incremental cost of just a few cents per kilo-Watt-hour. The purpose of this paper is to discuss: Amorphous Metal Alloy Technology; Energy Savings Opportunity; The Industrial Barriers and Remedies; Worldwide Demand; and A Low Risk Strategy. I wish this presentation will help KEPCO achieve their stated aims of ensuring sound development of the national economy and enhancement of public life through the economic and stable supply of electric power. AlliedSignal Korea Ltd. in conjunction with AlliedSignal Amorphous Metals in the U.S. are here to work with KEPCO, transformer manufacturers, industry, and government agencies to achieve greater efficiency in power distribution.

  18. Absolute surface energy calculations of Wurtzite (0001)/(000-1): a study of ZnO and GaN

    NASA Astrophysics Data System (ADS)

    Zhang, Jingzhao; Zhang, Yiou; Tse, Kinfai; Deng, Bei; Xu, Hu; Zhu, Junyi

    The accurate absolute surface energies of (0001)/(000-1) surfaces of wurtzite structures are crucial in determining the thin film growth mode of important energy materials. However, the surface energies still remain to be solved due to the intrinsic difficulty of calculating dangling bond energy of asymmetrically bonded surface atoms. We used a pseudo-hydrogen passivation method to estimate the dangling bond energy and calculate the polar surfaces of ZnO and GaN. The calculations were based on the pseudo chemical potentials obtained from a set of tetrahedral clusters or simple pseudo-molecules, using density functional theory approaches, for both GGA and HSE. And the surface energies of (0001)/(000-1) surfaces of wurtzite ZnO and GaN we obtained showed relatively high self-consistencies. A wedge structure calculation with a new bottom surface passivation scheme of group I and group VII elements was also proposed and performed to show converged absolute surface energy of wurtzite ZnO polar surfaces. Part of the computing resources was provided by the High Performance Cluster Computing Centre, Hong Kong Baptist University. This work was supported by the start-up funding and direct Grant with the Project code of 4053134 at CUHK.

  19. The spectral energy distribution of NGC 1275

    NASA Technical Reports Server (NTRS)

    Shields, G. A.; Oke, J. B.

    1975-01-01

    An analysis of absolute spectral energy distributions for NGC 1275 (Per A) covering the wavelength interval from 3300 A to 10,800 A is presented. The data are consistent with the heavy reddening discovered by Wampler (1971). The H-alpha intensity varied by less than 10% between the times of Wampler's earlier measurements and the two occasions of the present observations. The line-emitting region has a characteristic density of about 10 to the 4.5 power per cu cm, a mass of about 10 to the 5.5 power solar masses, and a volume filling factor of about 10 to the -6th power. The gas may be ionized by shock waves or by nonthermal or stellar radiation. It is suggested, in the vein of Minkowski's (1957) original proposal, that the high-velocity emission-line knots described by Minkowski are H II regions in a Perseus-cluster galaxy or intergalactic gas cloud seen in projection against NGC 1275.

  20. Atlas of quasar energy distributions

    NASA Technical Reports Server (NTRS)

    Elvis, Martin; Wilkes, Belinda J.; Mcdowell, Jonathan C.; Green, Richard F.; Bechtold, Jill; Willner, S. P.; Oey, M. S.; Polomski, Elisha; Cutri, Roc

    1994-01-01

    We present an atlas of the spectral energy distributions (SEDs) of normal, nonblazar, quasars over the whole available range (radio to 10 keV X-rays) of the electromagnetic spectrum. The primary (UVSX) sample includes 47 quasars for which the spectral energy distributions include X-ray spectral indices and UV data. Of these, 29 are radio quiet, and 18 are radio loud. The SEDs are presented both in figures and in tabular form, with additional tabular material published on CD-ROM. Previously unpublished observational data for a second set of quasars excluded from the primary sample are also tabulated. The effects of host galaxy starlight contamination and foreground extinction on the UVSX sample are considered and the sample is used to investigate the range of SED properties. Of course, the properties we derive are influenced strongly by the selection effects induced by quasar discovery techniques. We derive the mean energy distribution (MED) for radio-loud and radio-quiet objects and present the bolometric corrections derived from it. We note, however, that the dispersion about this mean is large (approximately one decade for both the infrared and ultraviolet components when the MED is normalized at the near-infrared inflection). At least part of the dispersion in the ultraviolet may be due to time variability, but this is unlikely to be important in the infrared. The existence of such a large dispersion indicates that the MED reflects only some of the properties of quasars and so should be used only with caution.

  1. Inelastic mean-free paths and surface excitation parameters by absolute reflection electron-energy loss measurements

    NASA Astrophysics Data System (ADS)

    Nagatomi, T.; Goto, K.

    2007-06-01

    An analytical approach is proposed for simultaneously determining the inelastic mean-free path (IMFP), the surface excitation parameter (SEP), and the differential SEP (DSEP) in absolute units from an absolute reflection electron energy loss spectroscopy (REELS) spectrum under the assumption that the normalized differential inelastic mean-free path for bulk excitations and the elastic scattering cross section are known. This approach was applied to an analysis of REELS spectra for Ni, and the IMFP, SEP, and DSEP in Ni for 300-3000eV electrons were determined. The resulting IMFPs showed good agreement with those calculated using the TPP-2M predictive equations and with those calculated from optical data. The deduced DSEPs show a reasonable agreement with those theoretically predicted. The obtained SEPs were compared with those calculated using several predictive equations. The present SEP results agreed well with the Chen formula with a material parameter proposed for Ni. The present approach has high potential for the experimental determination of IMFPs, SEPs, and DSEPs in absolute units.

  2. The analysis of space-time structure in QCD vacuum II: Dynamics of polarization and absolute X-distribution

    NASA Astrophysics Data System (ADS)

    Alexandru, Andrei; Draper, Terrence; Horváth, Ivan; Streuer, Thomas

    2011-08-01

    We propose a framework for quantitative evaluation of dynamical tendency for polarization in an arbitrary random variable that can be decomposed into a pair of orthogonal subspaces. The method uses measures based on comparisons of given dynamics to its counterpart with statistically independent components. The formalism of previously considered X-distributions is used to express the aforementioned comparisons, in effect putting the former approach on solid footing. Our analysis leads to the definition of a suitable correlation coefficient with clear statistical meaning. We apply the method to the dynamics induced by pure-glue lattice QCD in local left-right components of overlap Dirac eigenmodes. It is found that, in finite physical volume, there exists a non-zero physical scale in the spectrum of eigenvalues such that eigenmodes at smaller (fixed) eigenvalues exhibit convex X-distribution (positive correlation), while at larger eigenvalues the distribution is concave (negative correlation). This chiral polarization scale thus separates a regime where dynamics enhances chirality relative to statistical independence from a regime where it suppresses it, and gives an objective definition to the notion of "low" and "high" Dirac eigenmode. We propose to investigate whether the polarization scale remains non-zero in the infinite volume limit, in which case it would represent a new kind of low energy scale in QCD.

  3. Absolute Zero

    NASA Astrophysics Data System (ADS)

    Donnelly, Russell J.; Sheibley, D.; Belloni, M.; Stamper-Kurn, D.; Vinen, W. F.

    2006-12-01

    Absolute Zero is a two hour PBS special attempting to bring to the general public some of the advances made in 400 years of thermodynamics. It is based on the book “Absolute Zero and the Conquest of Cold” by Tom Shachtman. Absolute Zero will call long-overdue attention to the remarkable strides that have been made in low-temperature physics, a field that has produced 27 Nobel Prizes. It will explore the ongoing interplay between science and technology through historical examples including refrigerators, ice machines, frozen foods, liquid oxygen and nitrogen as well as much colder fluids such as liquid hydrogen and liquid helium. A website has been established to promote the series: www.absolutezerocampaign.org. It contains information on the series, aimed primarily at students at the middle school level. There is a wealth of material here and we hope interested teachers will draw their student’s attention to this website and its substantial contents, which have been carefully vetted for accuracy.

  4. A method for establishing absolute full-energy peak efficiency and its confidence interval for HPGe detectors

    NASA Astrophysics Data System (ADS)

    Rizwan, U.; Chester, A.; Domingo, T.; Starosta, K.; Williams, J.; Voss, P.

    2015-12-01

    A method is proposed for establishing the absolute efficiency calibration of a HPGe detector including the confidence interval in the energy range of 79.6-3451.2 keV. The calibrations were accomplished with the 133Ba, 60Co, 56Co and 152Eu point-like radioactive sources with only the 60Co source being activity calibrated to an accuracy of 2% at the 90% confidence level. All data sets measured from activity calibrated and uncalibrated sources were fit simultaneously using the linearized least squares method. The proposed fit function accounts for scaling of the data taken with activity uncalibrated sources to the data taken with the high accuracy activity calibrated source. The confidence interval for the fit was found analytically using the covariance matrix. Accuracy of the fit was below 3.5% at the 90% confidence level in the 79.6-3451.2 keV energy range.

  5. Absolute Beam Energy Measurement using Elastic ep Scattering at Thomas Jefferson National Accelerator Facility

    NASA Astrophysics Data System (ADS)

    Deur, Alexandre

    1999-10-01

    The Jefferson Lab beam energy measurement in Hall A using the elastic ep scattering will be described. This new, non-magnetic, energy measurement method allows a ( triangle E/E=10-4 ) precision. First-order corrections are canceled by the measurements of the electron and proton scattering angles for two symmetric kinematics. The measurement principle will be presented as well as the device and measurement results. Comparison with independent magnetic energy measurements of the same accuracy will be shown. This project is the result of a collaboration between the LPC: université Blaise Pascal/in2p3), Saclay and Jefferson Lab.

  6. Comparison of methods for generation of absolute reflectance-factor values for bidirectional reflectance-distribution function studies.

    PubMed

    Feng, X; Schott, J R; Gallagher, T

    1993-03-01

    Currently, spectrophotometric standard reference materials are calibrated only by using the illumination and viewing geometries recommended by the Commission Internationale de l'Eclairage, and for some geometries the spectral range is limited to the visible wavelengths. A need exists for procedures that calibrate standards at many other geometries and for a broader spectral range. Two methods for calibrating the spectral bidirectional reflectance factor are described. The absolute bidirectional reflectance factor of a sintered polytetrafluoroethylene (PTFE) sample is determined for nearly all the possible illumination and viewing geometries from 400 nm to 2500 nm. The references are a 45/0 reflectance standard calibrated by the National Institute of Standards and Technology and a sintered PTFE sample with a directional, hemispherical reflectance factor traceable to the Institute. The results of the two methods agree to within 0.01 in reflectance factor values. With this PTFE sample as a transfer standard, the instrument described can also be used to measure the absolute bidirectional reflectance factor at nearly all the illumination and viewing geometries from 400 nm to 2500 nm. PMID:20820258

  7. Absolute Summ

    NASA Astrophysics Data System (ADS)

    Phillips, Alfred, Jr.

    Summ means the entirety of the multiverse. It seems clear, from the inflation theories of A. Guth and others, that the creation of many universes is plausible. We argue that Absolute cosmological ideas, not unlike those of I. Newton, may be consistent with dynamic multiverse creations. As suggested in W. Heisenberg's uncertainty principle, and with the Anthropic Principle defended by S. Hawking, et al., human consciousness, buttressed by findings of neuroscience, may have to be considered in our models. Predictability, as A. Einstein realized with Invariants and General Relativity, may be required for new ideas to be part of physics. We present here a two postulate model geared to an Absolute Summ. The seedbed of this work is part of Akhnaton's philosophy (see S. Freud, Moses and Monotheism). Most important, however, is that the structure of human consciousness, manifest in Kenya's Rift Valley 200,000 years ago as Homo sapiens, who were the culmination of the six million year co-creation process of Hominins and Nature in Africa, allows us to do the physics that we do. .

  8. A Technique to Measure Energy Partitioning and Absolute Gas Pressures of Strombolian Explosions Using Doppler Radar at Erebus Volcano

    NASA Astrophysics Data System (ADS)

    Gerst, A.; Hort, M.; Kyle, P. R.; Voege, M.

    2008-12-01

    In 2005/06 we deployed three 24GHz (K-Band) continuous wave Doppler radar instruments at the crater rim of Erebus volcano in Antarctica. At the time there was a ~40 m wide, ~1000°C hot convecting phonolite lava lake, which was the source of ~0-6 Strombolian gas bubble explosions per day. We measured the velocities of ~50 explosions using a sample rate of 1-15 Hz. Data were downloaded in real-time through a wireless network. The measurements provide new insights into the still largely unknown mechanism of Strombolian eruptions, and help improve existing eruption models. We present a technique for a quasi in-situ measurement of the absolute pressure inside an eruption gas bubble. Pressures were derived using a simple eruption model and measured high resolution bubble surface velocities during explosions. Additionally, this technique allows us to present a comprehensive energy budget of a volcanic explosion as a time series of all important energy terms (i.e. potential, kinetic, dissipative, infrasonic, surface, seismic and thermal energy output). The absolute gas pressure inside rising expanding gas bubbles rapidly drops from ~3-10 atm (at the time when the lake starts to bulge) to ~1 atm before the bubble bursts, which usually occurs at radii of ~15-20m. These pressures are significantly lower than previously assumed for such explosions. The according internal energy of the gas agrees well with the observed total energy output. The results show that large explosions released about 109 to 1010 J each (equivalent to about 200-2000 kg of TNT), at a peak discharge rate frequently exceeding 109 W (the power output of a typical nuclear power plant). This dynamic output is mainly controlled by the kinetic and potential energy of the exploding magma shell, while other energy types were found to be much smaller (with the exception of thermal energy). Remarkably, most explosions at Erebus show two distinct surface acceleration peaks separated by ~0.3 seconds. This suggests

  9. Absolute single-ion solvation free energy scale in methanol determined by the lithium cluster-continuum approach.

    PubMed

    Pliego, Josefredo R; Miguel, Elizabeth L M

    2013-05-01

    Absolute solvation free energy of the lithium cation in methanol was calculated by the cluster-continuum quasichemical theory of solvation. Clusters with up to five methanol molecules were investigated using X3LYP, MP2, and MP4 methods with DZVP, 6-311+G(2df,2p), TZVPP+diff, and QZVPP+diff basis sets and including the cluster solvation through the PCM and SMD continuum models. Our calculations have determined a value of -118.1 kcal mol(-1) for the solvation free energy of the lithium, in close agreement with a value of -116.6 kcal mol(-1) consistent with the TATB assumption. Using data of solvation and transfer free energy of a pair of ions, electrode potentials and pKa, we have obtained the solvation free energy of 25 ions in methanol. Our analysis leads to a value of -253.6 kcal mol(-1) for the solvation free energy of the proton, which can be compared with the value of -263.5 kcal mol(-1) obtained by Kelly et al. using the cluster pair approximation. Considering that this difference is due to the methanol surface potential, we have estimated that it corresponds to -0.429 V. PMID:23570440

  10. Noninvasive imaging of absolute PpIX concentration distribution in nonmelanoma skin tumors at pre-PDT

    NASA Astrophysics Data System (ADS)

    Sunar, Ulas; Rohrbach, Daniel; Morgan, Janet; Zeitouni, Natalie

    2013-03-01

    Photodynamic Therapy (PDT) has proven to be an effective treatment option for nonmelanoma skin cancers. The ability to quantify the concentration of drug in the treated area is crucial for effective treatment planning as well as predicting outcomes. We utilized spatial frequency domain imaging for quantifying the accurate concentration of protoporphyrin IX (PpIX) in phantoms and in vivo. We correct fluorescence against the effects of native tissue absorption and scattering parameters. First we quantified the absorption and scattering of the tissue non-invasively. Then, we corrected raw fluorescence signal by compensating for optical properties to get the absolute drug concentration. After phantom experiments, we used basal cell carcinoma (BCC) model in Gli mice to determine optical properties and drug concentration in vivo at pre-PDT.

  11. Absolute elastic differential electron scattering cross sections in the intermediate energy region. III - SF6 and UF6

    NASA Technical Reports Server (NTRS)

    Srivastava, S. K.; Trajmar, S.; Chutjian, A.; Williams, W.

    1976-01-01

    A recently developed technique has been used to measure the ratios of elastic differential electron scattering cross sections (DCS) for SF6 and UF6 to those of He at electron impact energies of 5, 10, 15, 20, 30, 40, 50, 60, and 75 eV and at scattering angles of 20 to 135 deg. In order to obtain the absolute values of DCS from these ratios, He DCS of McConkey and Preston have been employed in the 20 to 90 deg range. At angles in the 90 to 135 deg range the recently determined cross sections of Srivastava and Trajmar have been utilized. From these DCS, elastic integral and momentum transfer cross sections have been obtained.

  12. The spectral energy distribution of Zeta Puppis and HD 50896

    NASA Technical Reports Server (NTRS)

    Holm, A. V.; Cassinelli, J. P.

    1977-01-01

    The ultraviolet spectral energy distribution of the O5f star Zeta Pup and the WN5 star HD 50896 are derived from OAO-2 observations with the calibration of Bless, Code, and Fairchild (1976). An estimate of the interstellar reddening (0.12 magnitude) of the Wolf-Rayet star is determined from the size of the characteristic interstellar extinction bump at 4.6 inverse microns. After correction for extinction, both stars show a flat energy distribution in the ultraviolet. The distribution of HD 50896 from 1100 A to 2 microns is in good agreement with results of extended model atmospheres, but some uncertainty remains because of the interstellar-extinction correction. The absolute energy distribution of Zeta Pup is fitted by a 42,000-K plane-parallel model if the model's flux is adjusted for the effects of electron scattering in the stellar wind and for UV line blanketing that was determined empirically from high-resolution Copernicus satellite observations. To achieve this fit, it is necessary to push both the spectroscopically determined temperature and the ultraviolet calibration to the limits of their probable errors.

  13. Measurement of Absolute Excitation Cross Sections in Highly-Charged Ions Using Electron Energy Loss and Merged Beams

    NASA Technical Reports Server (NTRS)

    Chutjian, A.; Smith, Steven J.; Lozano, J.

    2002-01-01

    There is increasing emphasis during this decade on understanding energy balance and phenomena observed in high electron temperature plasmas. The UV spectral return from FUSE, the X-ray spectral return from the HETG on Chandra and the LETGS 011 XMM-Newton are just beginning. Line emissions are almost entirely from highly-charged ions (HCIs) of C, N, 0, Ne, Mg, S, Si, Ca, and Fe. The Constellation-X mission will provide X-ray spectroscopy up to photon energies of 0.12 nm (10 keV) where primary line emitters will be HCIs. A variety of atomic parameters are required to model the stellar and solar plasma. These include cross sections for excitation, ionization, charge-exchange, X-ray emission, direct and indirect recombination, lifetimes and branching ratios, and dependences on l, m mixing by external E and B fields. In almost all cases the atomic quantities are calculated, and few comparisons to experiment have been carried out. Collision strengths and Einstein A-values are required to convert the observed spectral intensities to electron temperatures and densities in the stellar plasma. The JPL electron energy-loss and merged beam approach has been used to measure absolute collision strengths in a number of ions, with critical comparison made to the best available theories.

  14. A rare gas optics-free absolute photon flux and energy analyzer for solar and planetary observations

    NASA Technical Reports Server (NTRS)

    Judge, Darrell L.

    1994-01-01

    We have developed a prototype spectrometer for space applications requiring long term absolute EUV photon flux measurements. In this recently developed spectrometer, the energy spectrum of the incoming photons is transformed directly into an electron energy spectrum by taking advantage of the photoelectric effect in one of several rare gases at low pressures. Using an electron energy spectrometer, followed by an electron multiplier detector, pulses due to individual electrons are counted. The overall efficiency of this process can be made essentially independent of gain drifts in the signal path, and the secular degradation of optical components which is often a problem in other techniques is avoided. A very important feature of this approach is its freedom from the problem of overlapping spectral orders that plagues grating EUV spectrometers. An instrument with these features has not been flown before, but is essential to further advances in our understanding of solar EUV flux dynamics, and the coupled dynamics of terrestrial and planetary atmospheres. The detailed characteristics of this optics-free spectrometer are presented in the publications section.

  15. Panchromatic spectral energy distributions of Herschel sources

    NASA Astrophysics Data System (ADS)

    Berta, S.; Lutz, D.; Santini, P.; Wuyts, S.; Rosario, D.; Brisbin, D.; Cooray, A.; Franceschini, A.; Gruppioni, C.; Hatziminaoglou, E.; Hwang, H. S.; Le Floc'h, E.; Magnelli, B.; Nordon, R.; Oliver, S.; Page, M. J.; Popesso, P.; Pozzetti, L.; Pozzi, F.; Riguccini, L.; Rodighiero, G.; Roseboom, I.; Scott, D.; Symeonidis, M.; Valtchanov, I.; Viero, M.; Wang, L.

    2013-03-01

    Combining far-infrared Herschel photometry from the PACS Evolutionary Probe (PEP) and Herschel Multi-tiered Extragalactic Survey (HerMES) guaranteed time programs with ancillary datasets in the GOODS-N, GOODS-S, and COSMOS fields, it is possible to sample the 8-500 μm spectral energy distributions (SEDs) of galaxies with at least 7-10 bands. Extending to the UV, optical, and near-infrared, the number of bands increases up to 43. We reproduce the distribution of galaxies in a carefully selected restframe ten colors space, based on this rich data-set, using a superposition of multivariate Gaussian modes. We use this model to classify galaxies and build median SEDs of each class, which are then fitted with a modified version of the magphys code that combines stellar light, emission from dust heated by stars and a possible warm dust contribution heated by an active galactic nucleus (AGN). The color distribution of galaxies in each of the considered fields can be well described with the combination of 6-9 classes, spanning a large range of far- to near-infrared luminosity ratios, as well as different strength of the AGN contribution to bolometric luminosities. The defined Gaussian grouping is used to identify rare or odd sources. The zoology of outliers includes Herschel-detected ellipticals, very blue z ~ 1 Ly-break galaxies, quiescent spirals, and torus-dominated AGN with star formation. Out of these groups and outliers, a new template library is assembled, consisting of 32 SEDs describing the intrinsic scatter in the restframe UV-to-submm colors of infrared galaxies. This library is tested against L(IR) estimates with and without Herschel data included, and compared to eightother popular methods often adopted in the literature. When implementing Herschel photometry, these approaches produce L(IR) values consistent with each other within a median absolute deviation of 10-20%, the scatter being dominated more by fine tuning of the codes, rather than by the choice of

  16. A protocol for quantum energy distribution

    NASA Astrophysics Data System (ADS)

    Hotta, Masahiro

    2008-08-01

    In this Letter, a protocol called quantum energy distribution (QED) is proposed in which multi-parties can simultaneously extract positive energy on average from spin chains by use of common secret keys shared by an energy supplier. QED is robust against impersonation. An adversary, who does not have common secret keys and attempts to get energy, cannot obtain but give energy to spin chains. Total amount of energy transfer gives a lower bound of residual energy of a local cooling process by the energy supplier.

  17. Determination of energy distribution for photon and neutron microdosimetry

    NASA Astrophysics Data System (ADS)

    Todo, A. S.

    This work was undertaken to provide basic physical data for use in both microdosimetry and dosimetry of high energy photons and also in the neutron radiation field. Described is the formalism to determine the initial electron energy spectra in water irradiated by photons with energies up to 1 GeV. Calculations were performed with a Monte Carlo computer code, PHOEL-3, which is also described. The code treats explicitly the production of electron-positron pairs, Compton scattering, photoelectric absorption, and the emission of Auger electrons following the occurrence of K-shell vacancies in oxygen. The tables give directly the information needed to specify the absolute single-collision kerma in water, which approximates tissue, at each photon energy. Results for continuous photon energy spectra can be obtained by using linear interpolation with the tables. The conditions under which first-collision kerma approximate absorbed dose are discussed. A formula is given for estimating bremsstrahlung energy loss, one of the principal differences between kerma and absorbed dose in practical cases. A study has been carried out, on the use of cylindrical, energy-proportional pulse-height detector for determining microdosimetric quantities, as neutron fractional dose spectra, D (L), in the function of linear energy transfer (LET). In the present study the Hurst detector was used; this device satisfies the requirement of the Bragg-Gray principle. A Monte Carlo Method was developed to obtain the D(L) spectrum from a measured pulse-height spectrum H(h), and the knowledge of the distribution of recoil-particle track lenght, P(T) in the sensitive volume of the detector. These developed programs to find P(T) and D(L) are presented. The distribution of D(L) in LET were obtained using a known distribution of P(T) and the measured H(h) spectrum fromthe Cf-2 52 neutron source. All the results are discussed and the conclusions are presented.

  18. Energy Decomposition Analysis Based on Absolutely Localized Molecular Orbitals for Large-Scale Density Functional Theory Calculations in Drug Design.

    PubMed

    Phipps, M J S; Fox, T; Tautermann, C S; Skylaris, C-K

    2016-07-12

    We report the development and implementation of an energy decomposition analysis (EDA) scheme in the ONETEP linear-scaling electronic structure package. Our approach is hybrid as it combines the localized molecular orbital EDA (Su, P.; Li, H. J. Chem. Phys., 2009, 131, 014102) and the absolutely localized molecular orbital EDA (Khaliullin, R. Z.; et al. J. Phys. Chem. A, 2007, 111, 8753-8765) to partition the intermolecular interaction energy into chemically distinct components (electrostatic, exchange, correlation, Pauli repulsion, polarization, and charge transfer). Limitations shared in EDA approaches such as the issue of basis set dependence in polarization and charge transfer are discussed, and a remedy to this problem is proposed that exploits the strictly localized property of the ONETEP orbitals. Our method is validated on a range of complexes with interactions relevant to drug design. We demonstrate the capabilities for large-scale calculations with our approach on complexes of thrombin with an inhibitor comprised of up to 4975 atoms. Given the capability of ONETEP for large-scale calculations, such as on entire proteins, we expect that our EDA scheme can be applied in a large range of biomolecular problems, especially in the context of drug design. PMID:27248370

  19. Probing the Crystal Structure, Composition-Dependent Absolute Energy Levels, and Electrocatalytic Properties of Silver Indium Sulfide Nanostructures.

    PubMed

    Saji, Pintu; Ganguli, Ashok K; Bhat, Mohsin A; Ingole, Pravin P

    2016-04-18

    The absolute electronic energy levels in silver indium sulfide (AIS) nanocrystals (NCs) with varying compositions and crystallographic phases have been determined by using cyclic voltammetry. Different crystallographic phases, that is, metastable cubic, orthorhombic, monoclinic, and a mixture of cubic and orthorhombic AIS NCs, were studied. The band gap values estimated from the cyclic voltammetry measurements match well with the band gap values calculated from the diffuse reflectance spectra measurements. The AIS nanostructures were found to show good electrocatalytic activity towards the hydrogen evolution reaction (HER). Our results clearly establish that the electronic and electrocatalytic properties of AIS NCs are strongly sensitive to the composition and crystal structure of AIS NCs. Monoclinic AIS was found to be the most active HER electrocatalyst, with electrocatalytic activity that is almost comparable to the MoS2 -based nanostructures reported in the literature, whereas cubic AIS was observed to be the least active of the studied crystallographic phases and compositions. In view of the HER activity and electronic band structure parameters observed herein, we hypothesize that the Fermi energy level of AIS NCs is an important factor that decides the electrocatalytic efficiency of these nanocomposites. The work presented herein, in addition to being the first of its kind regarding the composition and phase-dependence of electrochemical aspects of AIS NCs, also presents a simple solvothermal method for the synthesis of different crystallographic phases with various Ag/In molar ratios. PMID:26812447

  20. Probing non-covalent interactions with a second generation energy decomposition analysis using absolutely localized molecular orbitals.

    PubMed

    Horn, Paul R; Mao, Yuezhi; Head-Gordon, Martin

    2016-08-17

    An energy decomposition analysis (EDA) separates a calculated interaction energy into as many interpretable contributions as possible; for instance, permanent and induced electrostatics, Pauli repulsions, dispersion and charge transfer. The challenge is to construct satisfactory definitions of all terms in the chemically relevant regime where fragment densities overlap, rendering unique definitions impossible. Towards this goal, we present an improved EDA for Kohn-Sham density functional theory (DFT) with properties that have previously not been simultaneously attained. Building on the absolutely localized molecular orbital (ALMO)-EDA, this second generation ALMO-EDA is variational and employs valid antisymmetric electronic wavefunctions to produce all five contributions listed above. These contributions moreover all have non-trivial complete basis set limits. We apply the EDA to the water dimer, the T-shaped and parallel-displaced benzene dimer, the p-biphthalate dimer "anti-electrostatic" hydrogen bonding complex, the biologically relevant binding of adenine and thymine in stacked and hydrogen-bonded configurations, the triply hydrogen-bonded guanine-cytosine complex, the interaction of Cl(-) with s-triazine and with the 1,3-dimethyl imidazolium cation, which is relevant to the study of ionic liquids, and the water-formaldehyde-vinyl alcohol ter-molecular radical cationic complex formed in the dissociative photoionization of glycerol. PMID:27492057

  1. Resilient Core Networks for Energy Distribution

    SciTech Connect

    Kuntze, Nicolai; Rudolph, Carsten; Leivesley, Sally; Manz, David O.; Endicott-Popovsky, Barbara E.

    2014-07-28

    Abstract—Substations and their control are crucial for the availability of electricity in today’s energy distribution. Ad- vanced energy grids with Distributed Energy Resources require higher complexity in substations, distributed functionality and communication between devices inside substations and between substations. Also, substations include more and more intelligent devices and ICT based systems. All these devices are connected to other systems by different types of communication links or are situated in uncontrolled environments. Therefore, the risk of ICT based attacks on energy grids is growing. Consequently, security measures to counter these risks need to be an intrinsic part of energy grids. This paper introduces the concept of a Resilient Core Network to interconnected substations. This core network provides essen- tial security features, enables fast detection of attacks and allows for a distributed and autonomous mitigation of ICT based risks.

  2. Validation of absolute axial neutron flux distribution calculations with MCNP with 197Au(n,γ)198Au reaction rate distribution measurements at the JSI TRIGA Mark II reactor.

    PubMed

    Radulović, Vladimir; Štancar, Žiga; Snoj, Luka; Trkov, Andrej

    2014-02-01

    The calculation of axial neutron flux distributions with the MCNP code at the JSI TRIGA Mark II reactor has been validated with experimental measurements of the (197)Au(n,γ)(198)Au reaction rate. The calculated absolute reaction rate values, scaled according to the reactor power and corrected for the flux redistribution effect, are in good agreement with the experimental results. The effect of different cross-section libraries on the calculations has been investigated and shown to be minor. PMID:24316530

  3. Distribution System Voltage Regulation by Distributed Energy Resources

    SciTech Connect

    Ceylan, Oguzhan; Liu, Guodong; Xu, Yan; Tomsovic, Kevin

    2014-01-01

    This paper proposes a control method to regulate voltages in 3 phase unbalanced electrical distribution systems. A constrained optimization problem to minimize voltage deviations and maximize distributed energy resource (DER) active power output is solved by harmony search algorithm. IEEE 13 Bus Distribution Test System was modified to test three different cases: a) only voltage regulator controlled system b) only DER controlled system and c) both voltage regulator and DER controlled system. The simulation results show that systems with both voltage regulators and DER control provide better voltage profile.

  4. Methods for Calculating the Absolute Entropy and free energy of biological systems based on ideas from Polymer Physics

    PubMed Central

    Meirovitch, Hagai

    2009-01-01

    The commonly used simulation techniques, Metropolis Monte Carlo (MC) and molecular dynamics (MD) are of a dynamical type which enables one to sample system configurations i correctly with the Boltzmann probability, PiB while the value of PiB is not provided directly; therefore, it is difficult to obtain the absolute entropy, S ~ -ln PiB, and the Helmholtz free energy, F. With a different simulation approach developed in polymer physics, a chain is grown step-by-step with transition probabilities (TPs), and thus their product is the value of the construction probability; therefore, the entropy is known. Because all exact simulation methods are equivalent, i.e. they lead to the same averages and fluctuations of physical properties, one can treat an MC or MD sample as if its members have rather been generated step-by-step. Thus, each configuration i of the sample can be reconstructed (from nothing) by calculating the TPs with which it could have been constructed. This idea applies also to bulk systems such as fluids or magnets. This approach has led earlier to the “local states” (LS) and the “hypothetical scanning” (HS) methods, which are approximate in nature. A recent development is the hypothetical scanning Monte Carlo (HSMC) (or molecular dynamics, HSMD) method which is based on stochastic TPs where all interactions are taken into account. In this respect HSMC(D) can be viewed as exact and the only approximation involved is due to insufficient MC(MD) sampling for calculating the TPs. The validity of HSMC has been established by applying it first to liquid argon, TIP3P water, self-avoiding walks, and polyglycine models, where the results for F were found to agree with those obtained by other methods. Subsequently, HSMD was applied to mobile loops of the enzymes porcine pancreatic α-amylase and acetylcholineesterase in explicit water, where the difference of F between the bound and free states of the loop was calculated. Currently HSMD is being extended for

  5. Methods for calculating the absolute entropy and free energy of biological systems based on ideas from polymer physics.

    PubMed

    Meirovitch, Hagai

    2010-01-01

    The commonly used simulation techniques, Metropolis Monte Carlo (MC) and molecular dynamics (MD) are of a dynamical type which enables one to sample system configurations i correctly with the Boltzmann probability, P(i)(B), while the value of P(i)(B) is not provided directly; therefore, it is difficult to obtain the absolute entropy, S approximately -ln P(i)(B), and the Helmholtz free energy, F. With a different simulation approach developed in polymer physics, a chain is grown step-by-step with transition probabilities (TPs), and thus their product is the value of the construction probability; therefore, the entropy is known. Because all exact simulation methods are equivalent, i.e. they lead to the same averages and fluctuations of physical properties, one can treat an MC or MD sample as if its members have rather been generated step-by-step. Thus, each configuration i of the sample can be reconstructed (from nothing) by calculating the TPs with which it could have been constructed. This idea applies also to bulk systems such as fluids or magnets. This approach has led earlier to the "local states" (LS) and the "hypothetical scanning" (HS) methods, which are approximate in nature. A recent development is the hypothetical scanning Monte Carlo (HSMC) (or molecular dynamics, HSMD) method which is based on stochastic TPs where all interactions are taken into account. In this respect, HSMC(D) can be viewed as exact and the only approximation involved is due to insufficient MC(MD) sampling for calculating the TPs. The validity of HSMC has been established by applying it first to liquid argon, TIP3P water, self-avoiding walks (SAW), and polyglycine models, where the results for F were found to agree with those obtained by other methods. Subsequently, HSMD was applied to mobile loops of the enzymes porcine pancreatic alpha-amylase and acetylcholinesterase in explicit water, where the difference in F between the bound and free states of the loop was calculated. Currently

  6. Distributed energy store railguns experiment and analysis

    SciTech Connect

    Holland, L.D.

    1984-01-01

    Electromagnetic acceleration of projectiles holds the potential for achieving higher velocities than yet achieved by any other means. A railgun is the simplest form of electromagnetic macroparticle accelerator and can generate the highest sustained accelerating force. The practical length of conventional railguns is limited by the impedance of the rails because current must be carried along the entire length of the rails. A railgun and power supply system called the distributed energy store railgun was proposed as a solution to this limitation. The distributed energy store railgun used multiple current sources connected to the rails of a railgun at points distributed along the bore. These current sources (energy stores) are turned on in sequence as the projectile moves down the bore so that current is fed to the railgun from behind the armature. In this system the length of the rails that carry the full armature current is less than the total length of the railgun. If a sufficient number of energy stores is used, this removes the limitation on the length of a railgun. An additional feature of distributed energy store type railguns is that they can be designed to maintain a constant pressure on the projectile being accelerated. A distributed energy store railgun was constructed and successfully operated. In addition to this first demonstration of the distributed energy store railgun principle, a theoretical model of the system was also constructed.

  7. An energy decomposition analysis for second-order Møller–Plesset perturbation theory based on absolutely localized molecular orbitals

    SciTech Connect

    Thirman, Jonathan Head-Gordon, Martin

    2015-08-28

    An energy decomposition analysis (EDA) of intermolecular interactions is proposed for second-order Møller–Plesset perturbation theory (MP2) based on absolutely localized molecular orbitals (ALMOs), as an extension to a previous ALMO-based EDA for self-consistent field methods. It decomposes the canonical MP2 binding energy by dividing the double excitations that contribute to the MP2 wave function into classes based on how the excitations involve different molecules. The MP2 contribution to the binding energy is decomposed into four components: frozen interaction, polarization, charge transfer, and dispersion. Charge transfer is defined by excitations that change the number of electrons on a molecule, dispersion by intermolecular excitations that do not transfer charge, and polarization and frozen interactions by intra-molecular excitations. The final two are separated by evaluations of the frozen, isolated wave functions in the presence of the other molecules, with adjustments for orbital response. Unlike previous EDAs for electron correlation methods, this one includes components for the electrostatics, which is vital as adjustment to the electrostatic behavior of the system is in some cases the dominant effect of the treatment of electron correlation. The proposed EDA is then applied to a variety of different systems to demonstrate that all proposed components behave correctly. This includes systems with one molecule and an external electric perturbation to test the separation between polarization and frozen interactions and various bimolecular systems in the equilibrium range and beyond to test the rest of the EDA. We find that it performs well on these tests. We then apply the EDA to a halogen bonded system to investigate the nature of the halogen bond.

  8. ENERGY EFFICIENCY AND ENVIRONMENTALLY FRIENDLY DISTRIBUTED ENERGY STORAGE BATTERY

    SciTech Connect

    LANDI, J.T.; PLIVELICH, R.F.

    2006-04-30

    Electro Energy, Inc. conducted a research project to develop an energy efficient and environmentally friendly bipolar Ni-MH battery for distributed energy storage applications. Rechargeable batteries with long life and low cost potentially play a significant role by reducing electricity cost and pollution. A rechargeable battery functions as a reservoir for storage for electrical energy, carries energy for portable applications, or can provide peaking energy when a demand for electrical power exceeds primary generating capabilities.

  9. Spectral Energy Distributions of Type 1 AGNs

    NASA Astrophysics Data System (ADS)

    Hao, Heng

    The spectral energy distributions (SEDs) of active galactic nuclei (AGNs) are essential to understand the physics of supermassive black holes (SMBHs) and their host galaxies. This thesis present a detailed study of AGN SED shapes in the optical-near infrared bands (0.3--3microm) for 413 X-ray selected Type 1 AGNs from the XMM-COSMOS Survey. We define a useful near-IR/optical index-index ('color-color') diagram to investigate the mixture of AGN continuum, host galaxy and reddening contributions. We found that ˜90% of the AGNs lie on mixing curves between the Elvis et al. (1994) mean AGN SED (E94) and a host galaxy, with only the modest reddening [E(B-V)=0.1--0.2] expected in type 1 AGNs. Lower luminosity and Eddington ratio objects have more host galaxy, as expected. The E94 template is remarkably good in describing the SED shape in the 0.3--3microrn decade of the spectrum over a range of 3.2 dex in LOPT, 2.7 dex in L/LEdd, and for redshifts up to 3. The AGN phenomenon is thus insensitive to absolute or relative accretion rate and to cosmic time. However, 10% of the AGNs are inconsistent with any AGN+host+reddening mix. These AGNs have weak or non-existent near-IR bumps, suggesting a lack of the hot dust characteristic of AGNs. The fraction of these hot-dust-poor AGNs evolves with redshift from 6% at low redshift (z < 2) to 20% at moderately high redshift (2 < z < 3.5). A similar fraction of HDP quasars are found in the Elvis et al. 1994 (BQS) and Richards et al. 2006 (SDSS) samples. The 1--3microm emission of the HDP quasars is a factor 2--4 smaller than the typical E94 AGN SED. The implied torus covering factor is 2%--29%, well below the 75% required by unified models. The weak hot dust emission seems to expose an extension of the accretion disk continuum in some of AGNs. For these, we estimate the outer edge of their accretion disks to lie at ˜104 Schwarzschild radii, more than ten times the gravitational stability radii. Either the host-dust is destroyed

  10. Energy optimization of water distribution systems

    SciTech Connect

    1994-09-01

    Energy costs associated with pumping treated water into the distribution system and boosting water pressures where necessary is one of the largest expenditures in the operating budget of a municipality. Due to the size and complexity of Detroit`s water transmission system, an energy optimization project has been developed to better manage the flow of water in the distribution system in an attempt to reduce these costs.

  11. DAQ Software Contributions, Absolute Scale Energy Calibration and Background Evaluation for the NOvA Experiment at Fermilab

    SciTech Connect

    Flumerfelt, Eric Lewis

    2015-08-01

    The NOvA (NuMI Off-axis ve [nu_e] Appearance) Experiment is a long-baseline accelerator neutrino experiment currently in its second year of operations. NOvA uses the Neutrinos from the Main Injector (NuMI) beam at Fermilab, and there are two main off-axis detectors: a Near Detector at Fermilab and a Far Detector 810 km away at Ash River, MN. The work reported herein is in support of the NOvA Experiment, through contributions to the development of data acquisition software, providing an accurate, absolute-scale energy calibration for electromagnetic showers in NOvA detector elements, crucial to the primary electron neutrino search, and through an initial evaluation of the cosmic background rate in the NOvA Far Detector, which is situated on the surface without significant overburden. Additional support work for the NOvA Experiment is also detailed, including DAQ Server Administration duties and a study of NOvA’s sensitivity to neutrino oscillations into a “sterile” state.

  12. Measured Absolute Cross Section of Charge Transfer in H + H2+ at Low Energy: Signature of vi = 2 and Trajectory Effects

    NASA Astrophysics Data System (ADS)

    Strom, R. A.; Bacani, K. G.; Chi, R. M.; Heczko, S. L.; Singh, B. N.; Tobar, J. A.; Vassantachart, A. K.; Andrianarijaona, V. M.; Seely, D. G.; Havener, C. C.

    2015-04-01

    Measurements of absolute cross sections of charge transfer (CT) in H + H2+--> H+ + H2 were conducted at the merged-beam apparatus at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, which can reliably create and access collision energies as low as 0.1 eV/u. The measured absolute cross section shows evidence of trajectory effects at low energy. Also, the comparison to state-to-state calculations (PRA 67 022708 (2003) suggests a strong contribution from vi = 2 of the H2+that are produced by the electron cyclotron resonance ion source. The data analysis will be presented here. Research supported by the NASA Solar & Heliospheric Physics Program NNH07ZDA001N, the Office of Fusion Energy Sciences and the Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences of the U.S. Department of Energy, the National Science Foundation through Grant No. PHY-1068877.

  13. Absolute photofission cross sections for /sup 235,238/U in the energy range 11. 5--30 MeV

    SciTech Connect

    Ries, H.; Mank, G.; Drexler, J.; Heil, R.; Huber, K.; Kneissl, U.; Ratzek, R.; Stroeher, H.; Weber, T.; Wilke, W.

    1984-06-01

    Absolute photofission cross sections of /sup 235/U and /sup 238/U have been measured with quasimonoenergetic photons from e/sup +/ annihilation and direct fragment detection between 11.5 and 30 MeV. The results obtained in the energy range of the giant dipole resonance (up to 18 MeV) are compared with those from previous experiments.

  14. A comparison of absolute performance of different correlative and mechanistic species distribution models in an independent area.

    PubMed

    Shabani, Farzin; Kumar, Lalit; Ahmadi, Mohsen

    2016-08-01

    To investigate the comparative abilities of six different bioclimatic models in an independent area, utilizing the distribution of eight different species available at a global scale and in Australia. Global scale and Australia. We tested a variety of bioclimatic models for eight different plant species employing five discriminatory correlative species distribution models (SDMs) including Generalized Linear Model (GLM), MaxEnt, Random Forest (RF), Boosted Regression Tree (BRT), Bioclim, together with CLIMEX (CL) as a mechanistic niche model. These models were fitted using a training dataset of available global data, but with the exclusion of Australian locations. The capabilities of these techniques in projecting suitable climate, based on independent records for these species in Australia, were compared. Thus, Australia is not used to calibrate the models and therefore it is as an independent area regarding geographic locations. To assess and compare performance, we utilized the area under the receiver operating characteristic (ROC) curves (AUC), true skill statistic (TSS), and fractional predicted areas for all SDMs. In addition, we assessed satisfactory agreements between the outputs of the six different bioclimatic models, for all eight species in Australia. The modeling method impacted on potential distribution predictions under current climate. However, the utilization of sensitivity and the fractional predicted areas showed that GLM, MaxEnt, Bioclim, and CL had the highest sensitivity for Australian climate conditions. Bioclim calculated the highest fractional predicted area of an independent area, while RF and BRT were poor. For many applications, it is difficult to decide which bioclimatic model to use. This research shows that variable results are obtained using different SDMs in an independent area. This research also shows that the SDMs produce different results for different species; for example, Bioclim may not be good for one species but works better

  15. New approach for absolute fluence distribution calculations in Monte Carlo simulations of light propagation in turbid media

    SciTech Connect

    Böcklin, Christoph Baumann, Dirk; Fröhlich, Jürg

    2014-02-14

    A novel way to attain three dimensional fluence rate maps from Monte-Carlo simulations of photon propagation is presented in this work. The propagation of light in a turbid medium is described by the radiative transfer equation and formulated in terms of radiance. For many applications, particularly in biomedical optics, the fluence rate is a more useful quantity and directly derived from the radiance by integrating over all directions. Contrary to the usual way which calculates the fluence rate from absorbed photon power, the fluence rate in this work is directly calculated from the photon packet trajectory. The voxel based algorithm works in arbitrary geometries and material distributions. It is shown that the new algorithm is more efficient and also works in materials with a low or even zero absorption coefficient. The capabilities of the new algorithm are demonstrated on a curved layered structure, where a non-scattering, non-absorbing layer is sandwiched between two highly scattering layers.

  16. Combined Use of Absolute and Differential Seismic Arrival Time Data to Improve Absolute Event Location

    NASA Astrophysics Data System (ADS)

    Myers, S.; Johannesson, G.

    2012-12-01

    Arrival time measurements based on waveform cross correlation are becoming more common as advanced signal processing methods are applied to seismic data archives and real-time data streams. Waveform correlation can precisely measure the time difference between the arrival of two phases, and differential time data can be used to constrain relative location of events. Absolute locations are needed for many applications, which generally requires the use of absolute time data. Current methods for measuring absolute time data are approximately two orders of magnitude less precise than differential time measurements. To exploit the strengths of both absolute and differential time data, we extend our multiple-event location method Bayesloc, which previously used absolute time data only, to include the use of differential time measurements that are based on waveform cross correlation. Fundamentally, Bayesloc is a formulation of the joint probability over all parameters comprising the multiple event location system. The Markov-Chain Monte Carlo method is used to sample from the joint probability distribution given arrival data sets. The differential time component of Bayesloc includes scaling a stochastic estimate of differential time measurement precision based the waveform correlation coefficient for each datum. For a regional-distance synthetic data set with absolute and differential time measurement error of 0.25 seconds and 0.01 second, respectively, epicenter location accuracy is improved from and average of 1.05 km when solely absolute time data are used to 0.28 km when absolute and differential time data are used jointly (73% improvement). The improvement in absolute location accuracy is the result of conditionally limiting absolute location probability regions based on the precise relative position with respect to neighboring events. Bayesloc estimates of data precision are found to be accurate for the synthetic test, with absolute and differential time measurement

  17. Tailored ion energy distributions on plasma electrodes

    SciTech Connect

    Economou, Demetre J.

    2013-09-15

    As microelectronic device features continue to shrink approaching atomic dimensions, control of the ion energy distribution on the substrate during plasma etching and deposition becomes increasingly critical. The ion energy should be high enough to drive ion-assisted etching, but not too high to cause substrate damage or loss of selectivity. In many cases, a nearly monoenergetic ion energy distribution (IED) is desired to achieve highly selective etching. In this work, the author briefly reviews: (1) the fundamentals of development of the ion energy distribution in the sheath and (2) methods to control the IED on plasma electrodes. Such methods include the application of “tailored” voltage waveforms on an electrode in continuous wave plasmas, or the application of synchronous bias on a “boundary electrode” during a specified time window in the afterglow of pulsed plasmas.

  18. Distribution of Atomic Hydrogen in the Upper Atmosphere: Assessment of Absolute Densities and Variations in the light of Recent Observations

    NASA Astrophysics Data System (ADS)

    Bishop, J.

    2002-12-01

    Knowledge of atomic hydrogen densities ([H](z)) in the upper atmosphere is important both for understanding mesospheric-lower thermospheric (MLT) chemistry and for realistic modeling of geocoronal interactions with ionized populations (e.g., plasmasphere, ring current). Work culminating in the 1970's failed to achieve consistent determinations of the distribution of atomic hydrogen; because of this, the relevance of [H](z) determinations in other areas of aeronomic research has remained unacknowledged. Extensive independent sets of optical data, coupled with improved solar Lyman line series irradiances and corrections of assumptions used in the earlier data analyses, however, now enable us to resolve the older inconsistencies and pursue determination of quantities of genuine interest: thermospheric atomic hydrogen vertical fluxes, characteristics of the satellite atom component in the geocorona, etc. These data sets include: Wisconsin Hα\\ Mapper (WHAM) Fabry-Perot data from Kitt Peak Observatory, providing ~ \\ 40,000\\ spectra of geocoronal and galactic Balmer~α intensities beginning in 1997; very high resolution Fabry-Perot data from Pine Bluff Observatory (Wisconsin) of both Balmer~α\\ and Balmer~β\\ intensities and line profiles from 2000-2001; FUSE EUV measurements of Lyman line series intensities from 1999 and 2000 (excluding Lyman~α); MiniSat1/EURD EUV spectrometer measurements of Lyman line series intensities (excluding Lyman~α) from 1997 to 2001; and IMAGE/GEO Lyman~α\\ intensity data from geocoronal positions (satellite apogees ~ 7~R E). In this presentation, modeling analyses of representative data subsets will be discussed, focusing on results relevant to broader aeronomy topics.

  19. Energy distribution in the quantum spectrum

    NASA Astrophysics Data System (ADS)

    Bi, Siwen

    2015-11-01

    At first this paper summarizes the current situation and historical development of the spectrum research, the difficulties and demand background. Then it introduces the research status of quantum spectrum and research ideas of energy distribution in quantum spectrum. We explain the concept of quantum spectrum, the difference between quantum spectrum and spectrum. We elaborate energy distribution in quantum spectrum from three aspects, which are representation, feature and mechanism of quantum spectrum energy distribution. Finally we describe the application of monochrome quantum spectrum about imaging and detection aspects and give an overview of the quantum spectrum. Based on above research results we continue to study and achieve the detection of multi-spectral imaging, which provide the technical basis for the application. We try access to an advanced stage of quantum spectrum study as soon as possible.

  20. A Fossilized Energy Distribution of Lightning.

    PubMed

    Pasek, Matthew A; Hurst, Marc

    2016-01-01

    When lightning strikes soil, it may generate a cylindrical tube of glass known as a fulgurite. The morphology of a fulgurite is ultimately a consequence of the energy of the lightning strike that formed it, and hence fulgurites may be useful in elucidating the energy distribution frequency of cloud-to-ground lightning. Fulgurites from sand mines in Polk County, Florida, USA were collected and analyzed to determine morphologic properties. Here we show that the energy per unit length of lightning strikes within quartz sand has a geometric mean of ~1.0 MJ/m, and that the distribution is lognormal with respect to energy per length and frequency. Energy per length is determined from fulgurites as a function of diameter, and frequency is determined both by cumulative number and by cumulative length. This distribution parallels those determined for a number of lightning parameters measured in actual atmospheric discharge events, such as charge transferred, voltage, and action integral. This methodology suggests a potential useful pathway for elucidating lightning energy and damage potential of strikes. PMID:27466230

  1. A Fossilized Energy Distribution of Lightning

    NASA Astrophysics Data System (ADS)

    Pasek, Matthew A.; Hurst, Marc

    2016-07-01

    When lightning strikes soil, it may generate a cylindrical tube of glass known as a fulgurite. The morphology of a fulgurite is ultimately a consequence of the energy of the lightning strike that formed it, and hence fulgurites may be useful in elucidating the energy distribution frequency of cloud-to-ground lightning. Fulgurites from sand mines in Polk County, Florida, USA were collected and analyzed to determine morphologic properties. Here we show that the energy per unit length of lightning strikes within quartz sand has a geometric mean of ~1.0 MJ/m, and that the distribution is lognormal with respect to energy per length and frequency. Energy per length is determined from fulgurites as a function of diameter, and frequency is determined both by cumulative number and by cumulative length. This distribution parallels those determined for a number of lightning parameters measured in actual atmospheric discharge events, such as charge transferred, voltage, and action integral. This methodology suggests a potential useful pathway for elucidating lightning energy and damage potential of strikes.

  2. A Fossilized Energy Distribution of Lightning

    PubMed Central

    Pasek, Matthew A.; Hurst, Marc

    2016-01-01

    When lightning strikes soil, it may generate a cylindrical tube of glass known as a fulgurite. The morphology of a fulgurite is ultimately a consequence of the energy of the lightning strike that formed it, and hence fulgurites may be useful in elucidating the energy distribution frequency of cloud-to-ground lightning. Fulgurites from sand mines in Polk County, Florida, USA were collected and analyzed to determine morphologic properties. Here we show that the energy per unit length of lightning strikes within quartz sand has a geometric mean of ~1.0 MJ/m, and that the distribution is lognormal with respect to energy per length and frequency. Energy per length is determined from fulgurites as a function of diameter, and frequency is determined both by cumulative number and by cumulative length. This distribution parallels those determined for a number of lightning parameters measured in actual atmospheric discharge events, such as charge transferred, voltage, and action integral. This methodology suggests a potential useful pathway for elucidating lightning energy and damage potential of strikes. PMID:27466230

  3. Absolute calibration of the Agfa Structurix series films at energies between 2.7 and 6.2 keVa)

    NASA Astrophysics Data System (ADS)

    Lanier, N. E.; Cowan, J. S.

    2014-11-01

    Although photo-emulsion technology is many decades old, x-ray film still remains a key asset for diagnosing hydrodynamic features in High-Energy Density (HED) experiments. For decades, the preferred option had been Kodak's direct exposure film. After its discontinuance in 2004, the push to find alternatives began. In many situations, the Agfa Structurix series offers the most favorable substitute, but being new to the HED community, its characterization was lacking. To remedy this, recent experiments, conducted at Brookhaven's National Synchrotron Light Source, provide absolute, monochromatic calibration data for the Agfa Structurix series films at K-shell backlighter energies between 2.7 and 6.2 keV. Absolute response curves are presented for Agfa D8, D7, D4, D4sc, D3, and D2. Moreover, the transmission of each film type is also measured.

  4. Electron energy-distribution functions in gases

    SciTech Connect

    Pitchford, L.C.

    1981-01-01

    Numerical calculation of the electron energy distribution functions in the regime of drift tube experiments is discussed. The discussion is limited to constant applied fields and values of E/N (ratio of electric field strength to neutral density) low enough that electron growth due to ionization can be neglected. (GHT)

  5. Absolute cascade-free cross-sections for the 2S to 2P transition in Zn(+) using electron-energy-loss and merged-beams methods

    NASA Technical Reports Server (NTRS)

    Smith, Steven J.; Man, K.-F.; Chutjian, A.; Mawhorter, R. J.; Williams, I. D.

    1991-01-01

    Absolute cascade-free excitation cross-sections in an ion have been measured for the resonance 2S to 2P transition in Zn(+) using electron-energy-loss and merged electron-ion beams methods. Measurements were carried out at electron energies of below threshold to 6 times threshold. Comparisons are made with 2-, 5-, and 15-state close-coupling and distorted-wave theories. There is good agreement between experiment and the 15-state close-coupling cross-sections over the energy range of the calculations.

  6. The energy distribution of Sirius B

    NASA Technical Reports Server (NTRS)

    Boehm-Vitense, E.

    1979-01-01

    The origin of the X-ray emission observed from the DA white dwarf Sirius B is investigated on the basis of low-resolution short wavelength IUE spectrum. Following a correction for the influence of scattered light from Sirius A, the intensity distribution of Sirius B is obtained as a function of wavelength. Comparison of the continuous energy distribution with model atmosphere energy distributions indicates an effective temperature of 25,500 K, which is not high enough to explain the observed X rays as normal photospheric radiation. In addition, with the exception of an unusual feature in the neighborhood of the C I 1657 line, no clear evidence is found of emission lines indicative of a corona, chromosphere or disk, and the origin of the X rays remains unknown.

  7. Energy Storage and Distributed Energy Generation Project, Final Project Report

    SciTech Connect

    Schwank, Johannes; Mader, Jerry; Chen, Xiaoyin; Mi, Chris; Linic, Suljo; Sastry, Ann Marie; Stefanopoulou, Anna; Thompson, Levi; Varde, Keshav

    2008-03-31

    This report serves as a Final Report under the “Energy Storage and Distribution Energy Generation Project” carried out by the Transportation Energy Center (TEC) at the University of Michigan (UM). An interdisciplinary research team has been working on fundamental and applied research on: -distributed power generation and microgrids, -power electronics, and -advanced energy storage. The long-term objective of the project was to provide a framework for identifying fundamental research solutions to technology challenges of transmission and distribution, with special emphasis on distributed power generation, energy storage, control methodologies, and power electronics for microgrids, and to develop enabling technologies for novel energy storage and harvesting concepts that can be simulated, tested, and scaled up to provide relief for both underserved and overstressed portions of the Nation’s grid. TEC’s research is closely associated with Sections 5.0 and 6.0 of the DOE "Five-year Program Plan for FY2008 to FY2012 for Electric Transmission and Distribution Programs, August 2006.”

  8. Absolute calibration of photostimulable image plate detectors used as (0.5-20 MeV) high-energy proton detectors.

    PubMed

    Mancić, A; Fuchs, J; Antici, P; Gaillard, S A; Audebert, P

    2008-07-01

    In this paper, the absolute calibration of photostimulable image plates (IPs) used as proton detectors is presented. The calibration is performed in a wide range of proton energies (0.5-20 MeV) by exposing simultaneously the IP and calibrated detectors (radiochromic films and solid state detector CR39) to a source of broadband laser-accelerated protons, which are spectrally resolved. The final result is a calibration curve that enables retrieving the proton number from the IP signal. PMID:18681694

  9. Teaching Absolute Value Meaningfully

    ERIC Educational Resources Information Center

    Wade, Angela

    2012-01-01

    What is the meaning of absolute value? And why do teachers teach students how to solve absolute value equations? Absolute value is a concept introduced in first-year algebra and then reinforced in later courses. Various authors have suggested instructional methods for teaching absolute value to high school students (Wei 2005; Stallings-Roberts…

  10. Stepwise assembling of polypeptide chain energy distributions.

    PubMed

    Jacchieri, S G

    2001-03-01

    The principles and application of conformational analysis software that makes use of a new algorithm are described. It is known that the existence of a local energy minimum in the energy landscape is in general related to the clustering of polypeptide chain conformations near that energy value or, in other words, to a high density of states. A criterion based on this principle is part of an algorithm employed to select subsets of polypeptide chain conformations in broad energy ranges. Chain fragments belonging to these subsets are then combined to build larger polypeptide chains and the corresponding energy distributions. The functionality of the various operations employed in the process is described and the FORTRAN 77 source code that defines the algorithm is listed. The methodology is illustrated with a calculation involving three chain fragments belonging to the cellular prion protein (PrP(C)). PMID:11219430

  11. Energy distribution in disordered elastic networks

    NASA Astrophysics Data System (ADS)

    Plaza, Gustavo R.

    2010-09-01

    Disordered networks are found in many natural and artificial materials, from gels or cytoskeletal structures to metallic foams or bones. Here, the energy distribution in this type of networks is modeled, taking into account the orientation of the struts. A correlation between the orientation and the energy per unit volume is found and described as a function of the connectivity in the network and the relative bending stiffness of the struts. If one or both parameters have relatively large values, the struts aligned in the loading direction present the highest values of energy. On the contrary, if these have relatively small values, the highest values of energy can be reached in the struts oriented transversally. This result allows explaining in a simple way remodeling processes in biological materials, for example, the remodeling of trabecular bone and the reorganization in the cytoskeleton. Additionally, the correlation between the orientation, the affinity, and the bending-stretching ratio in the network is discussed.

  12. Absolute calibration of Kodak Biomax-MS film response to x rays in the 1.5- to 8-keV energy range

    SciTech Connect

    Marshall, F. J.; Knauer, J. P.; Anderson, D.; Schmitt, B. L

    2006-10-15

    The absolute response of Kodak Biomax-MS film to x rays in the range from 1.5- to 8-keV has been measured using a laboratory electron-beam generated x-ray source. The measurements were taken at specific line energies by using Bragg diffraction to produce monochromatic beams of x rays. Multiple exposures were taken on Biomax MS film up to levels exceeding optical densities of 2 as measured by a microdensitometer. The absolute beam intensity for each exposure was measured with a Si(Li) detector. Additional response measurements were taken with Kodak direct exposure film (DEF) so as to compare the results of this technique to previously published calibrations. The Biomax-MS results have been fitted to a semiempirical mathematical model (Knauer et al., these proceedings). Users of the model can infer absolute fluences from observed exposure levels at either interpolated or extrapolated energies. To summarize the results: Biomax MS has comparable sensitivity to DEF film below 3 keV but has reduced sensitivity above 3 keV ({approx}50%). The lower exposure results from thinner emulsion layers, designed for use with phosphor screens. The ease with which Biomax-MS can be used in place of DEF (same format film, same developing process, and comparable sensitivity) makes it a good replacement.

  13. Absolute calibration of Kodak Biomax-MS film response to x rays in the 1.5- to 8-keV energy range

    NASA Astrophysics Data System (ADS)

    Marshall, F. J.; Knauer, J. P.; Anderson, D.; Schmitt, B. L.

    2006-10-01

    The absolute response of Kodak Biomax-MS film to x rays in the range from 1.5- to 8-keV has been measured using a laboratory electron-beam generated x-ray source. The measurements were taken at specific line energies by using Bragg diffraction to produce monochromatic beams of x rays. Multiple exposures were taken on Biomax MS film up to levels exceeding optical densities of 2 as measured by a microdensitometer. The absolute beam intensity for each exposure was measured with a Si (Li) detector. Additional response measurements were taken with Kodak direct exposure film (DEF) so as to compare the results of this technique to previously published calibrations. The Biomax-MS results have been fitted to a semiempirical mathematical model (Knauer et al., these proceedings). Users of the model can infer absolute fluences from observed exposure levels at either interpolated or extrapolated energies. To summarize the results: Biomax MS has comparable sensitivity to DEF film below 3keV but has reduced sensitivity above 3keV (˜50%). The lower exposure results from thinner emulsion layers, designed for use with phosphor screens. The ease with which Biomax-MS can be used in place of DEF (same format film, same developing process, and comparable sensitivity) makes it a good replacement.

  14. Absolute far-ultraviolet spectrophotometry of hot subluminous stars from Voyager

    SciTech Connect

    Holberg, J.B.; Ali, B.; Carone, T.E.; Polidan, R.S. NASA, Goddard Space Flight Center, Greenbelt, MD )

    1991-07-01

    Observations, obtained with the Voyager ultraviolet spectrometers, are presented of absolute fluxes for two well-known hot subluminous stars: BD + 28 deg 4211, an sdO, and G191 - B2B, a hot DA white dwarf. Complete absolute energy distributions for these two stars, from the Lyman limit at 912 A to 1 micron, are given. For BD + 28 deg 4211, a single power law closely represents the entire observed energy distribution. For G191 - B2B, a pure hydrogen model atmosphere provides an excellent match to the entire absolute energy distribution. Voyager absolute fluxes are discussed in relation to those reported from various sounding rocket experiments, including a recent rocket observation of BD + 28 deg 4211. 43 refs.

  15. Absolute Calibration of Kodak Biomax-MS Film Response to X Rays in the 1.5- to 8-keV Energy Range

    SciTech Connect

    Marshall, F.J.; Knauer, J.P.; Anderson, D.; Schmitt, B.L.

    2006-09-28

    The absolute response of Kodak Biomax-MS film to x rays in the range from 1.5- to 8-keV has been measured using a laboratory e-beam generated x-ray source. The measurements were taken at specific line energies by using Bragg diffraction to produce monochromatic beams of x rays. Multiple exposures were taken on Biomax MS film up to levels exceeding optical densities of 2 as measured by a microdensitometer. The absolute beam intensity for each exposure was measured with a Si(Li) detector. Additional response measurements were taken with Kodak direct exposure film (DEF) so as to compare the results of this technique to previously published calibrations.

  16. Distributed energy store railgun; The limiting case

    SciTech Connect

    Marshall, R.A. )

    1991-01-01

    This paper reports that when the limiting case of a distributed energy store railgun is analyzed, i.e., the case where the space between adjacent energy stores become indefinitely small, three important results are obtained. First, the shape of the current pulse delivered by each store is sinusoidal and an exponential tail. Second, the rail-to-rail voltage behind the rear-most active store approaches zero. Third, it is not possible to choose parameters in such a way that capacitor crowbars can be eliminated.

  17. Pseudo-Hydrogen Passivation: A Novel Way to Calculate Absolute Surface Energy of Zinc Blende (111)/(͞1 ͞1 ͞1) Surface

    NASA Astrophysics Data System (ADS)

    Zhang, Yiou; Zhang, Jingzhao; Tse, Kinfai; Wong, Lun; Chan, Chunkai; Deng, Bei; Zhu, Junyi

    2016-02-01

    Determining accurate absolute surface energies for polar surfaces of semiconductors has been a great challenge in decades. Here, we propose pseudo-hydrogen passivation to calculate them, using density functional theory approaches. By calculating the energy contribution from pseudo-hydrogen using either a pseudo molecule method or a tetrahedral cluster method, we obtained (111)/ surfaces energies of Si, GaP, GaAs, and ZnS with high self-consistency. This method quantitatively confirms that surface energy is determined by the number and the energy of dangling bonds of surface atoms. Our findings may greatly enhance the basic understandings of different surfaces and lead to novel strategies in the crystal growth.

  18. Pseudo-Hydrogen Passivation: A Novel Way to Calculate Absolute Surface Energy of Zinc Blende (111)/(¯1 ¯1 ¯1) Surface

    PubMed Central

    Zhang, Yiou; Zhang, Jingzhao; Tse, Kinfai; Wong, Lun; Chan, Chunkai; Deng, Bei; Zhu, Junyi

    2016-01-01

    Determining accurate absolute surface energies for polar surfaces of semiconductors has been a great challenge in decades. Here, we propose pseudo-hydrogen passivation to calculate them, using density functional theory approaches. By calculating the energy contribution from pseudo-hydrogen using either a pseudo molecule method or a tetrahedral cluster method, we obtained (111)/ surfaces energies of Si, GaP, GaAs, and ZnS with high self-consistency. This method quantitatively confirms that surface energy is determined by the number and the energy of dangling bonds of surface atoms. Our findings may greatly enhance the basic understandings of different surfaces and lead to novel strategies in the crystal growth. PMID:26831640

  19. Eosinophil count - absolute

    MedlinePlus

    Eosinophils; Absolute eosinophil count ... the white blood cell count to give the absolute eosinophil count. ... than 500 cells per microliter (cells/mcL). Normal value ranges may vary slightly among different laboratories. Talk ...

  20. Absolute cross sections for the dissociation of hydrogen cluster ions in high-energy collisions with helium atoms

    SciTech Connect

    Eden, S.; Tabet, J.; Samraoui, K.; Louc, S.; Farizon, B.; Farizon, M.; Ouaskit, S.; Maerk, T. D.

    2006-02-15

    Absolute dissociation cross sections are reported for H{sub n}{sup +} clusters of varied mass (n=3,5,...,35) following collisions with He atoms at 60 keV/amu. Initial results have been published previously for a smaller range of cluster sizes [Ouaskit et al., Phys. Rev. A 49, 1484 (1994)]. The present extended study includes further experimental results, reducing the statistical errors associated with the absolute cross sections. The previously suggested quasilinear dependence of the H{sub n}{sup +} dissociation cross sections upon n is developed with reference to expected series of geometrical shells of H{sub 2} molecules surrounding a H{sub 3}{sup +} core. Recent calculations identify n=9 as corresponding to the first closed H{sub 2} shell [e.g., Stich et al., J. Chem. Phys. 107, 9482 (1997)]. Recurrence of the distinct characteristics observed in the dissociation-cross-section dependence upon cluster size around n=9 provides the basis for the presently proposed subsequent closed shells at n=15, 21, 27, and 33, in agreement with the calculations of Nagashima et al. [J. Phys. Chem. 96, 4294 (1992)].

  1. New approaches for calculating absolute surface energies of wurtzite (0001)/(000 1 ¯ ): A study of ZnO and GaN

    NASA Astrophysics Data System (ADS)

    Zhang, Jingzhao; Zhang, Yiou; Tse, Kinfai; Deng, Bei; Xu, Hu; Zhu, Junyi

    2016-05-01

    The accurate absolute surface energies of (0001)/(000 1 ¯ ) surfaces of wurtzite structures are crucial in determining the thin film growth mode of important energy materials. However, the surface energies still remain to be solved due to the intrinsic difficulty of calculating the dangling bond energy of asymmetrically bonded surface atoms. In this study, we used a pseudo-hydrogen passivation method to estimate the dangling bond energy and calculate the polar surfaces of ZnO and GaN. The calculations were based on the pseudo chemical potentials obtained from a set of tetrahedral clusters or simple pseudo-molecules, using density functional theory approaches. The surface energies of (0001)/(000 1 ¯ ) surfaces of wurtzite ZnO and GaN that we obtained showed relatively high self-consistencies. A wedge structure calculation with a new bottom surface passivation scheme of group-I and group-VII elements was also proposed and performed to show converged absolute surface energy of wurtzite ZnO polar surfaces, and these results were also compared with the above method. The calculated results generally show that the surface energies of GaN are higher than those of ZnO, suggesting that ZnO tends to wet the GaN substrate, while GaN is unlikely to wet ZnO. Therefore, it will be challenging to grow high quality GaN thin films on ZnO substrates; however, high quality ZnO thin film on GaN substrate would be possible. These calculations and comparisons may provide important insights into crystal growth of the above materials, thereby leading to significant performance enhancements in semiconductor devices.

  2. Distributed Energy Communications & Controls, Lab Activities - Summary

    SciTech Connect

    Rizy, D Tom

    2010-01-01

    The purpose is to develop controls for inverter-based renewable and non-renewable distributed energy systems to provide local voltage, power and power quality support for loads and the power grid. The objectives are to (1) develop adaptive controls for inverter-based distributed energy (DE) systems when there are multiple inverters on the same feeder and (2) determine the impact of high penetration high seasonal energy efficiency ratio (SEER) air conditioning (A/C) units on power systems during sub-transmission faults which can result in an A/C compressor motor stall and assess how inverter-based DE can help to mitigate the stall event. The Distributed Energy Communications & Controls Laboratory (DECC) is a unique facility for studying dynamic voltage, active power (P), non-active power (Q) and power factor control from inverter-based renewable distributed energy (DE) resources. Conventionally, inverter-based DE systems have been designed to provide constant, close to unity power factor and thus not provide any voltage support. The DECC Lab interfaces with the ORNL campus distribution system to provide actual power system testing of the controls approach. Using mathematical software tools and the DECC Lab environment, we are developing and testing local, autonomous and adaptive controls for local voltage control and P & Q control for inverter-based DE. We successfully tested our active and non-active power (P,Q) controls at the DECC laboratory along with voltage regulation controls. The new PQ control along with current limiter controls has been tested on our existing inverter test system. We have tested both non-adaptive and adaptive control modes for the PQ control. We have completed several technical papers on the approaches and results. Electric power distribution systems are experiencing outages due to a phenomenon known as fault induced delayed voltage recovery (FIDVR) due to air conditioning (A/C) compressor motor stall. Local voltage collapse from FIDVR is

  3. Dynamic Voltage Regulation Using Distributed Energy Resources

    SciTech Connect

    Xu, Yan; Rizy, D Tom; Li, Fangxing; Kueck, John D

    2007-01-01

    Many distributed energy resources (DE) are near load centres and equipped with power electronics converters to interface with the grid, therefore it is feasible for DE to provide ancillary services such as voltage regulation, nonactive power compensation, and power factor correction. A synchronous condenser and a microturbine with an inverter interface are implemented in parallel in a distribution system to regulate the local voltage. Voltage control schemes of the inverter and the synchronous condenser are developed. The experimental results show that both the inverter and the synchronous condenser can regulate the local voltage instantaneously, while the dynamic response of the inverter is faster than the synchronous condenser; and that integrated voltage regulation (multiple DE perform voltage regulation) can increase the voltage regulation capability, increase the lifetime of the equipment, and reduce the capital and operation costs.

  4. Infrared Spectral Energy Distributions of Nearby Galaxies

    NASA Astrophysics Data System (ADS)

    Dale, D. A.; Bendo, G. J.; Engelbracht, C. W.; Gordon, K. D.; Regan, M. W.; Armus, L.; Cannon, J. M.; Calzetti, D.; Draine, B. T.; Helou, G.; Joseph, R. D.; Kennicutt, R. C.; Li, A.; Murphy, E. J.; Roussel, H.; Walter, F.; Hanson, H. M.; Hollenbach, D. J.; Jarrett, T. H.; Kewley, L. J.; Lamanna, C. A.; Leitherer, C.; Meyer, M.; Rieke, G. H.; Rieke, M. J.; Sheth, K.; Smith, J. D. T.; Thornley, M. D.

    2005-05-01

    The Spitzer Infrared Nearby Galaxies Survey (SINGS) is carrying out a comprehensive multi-wavelength survey on a sample of 75 nearby galaxies. The 1-850 \\micron\\ spectral energy distributions are presented for the first portion of the SINGS sample using broadband imaging data from Spitzer, 2MASS, ISO, IRAS, and SCUBA. The infrared colors derived from the globally-integrated Spitzer data are generally consistent with the previous generation of models that were developed based on global data for normal star-forming galaxies, though significant deviations are observed. Spitzer's excellent sensitivity and resolution also allow a detailed investigation of the infrared spectral energy distributions for various locations within the three large, nearby galaxies NGC 3031 (M 81), NGC 5194 (M 51), and NGC 7331. A wide variety of spectral shapes are found within each galaxy, especially for NGC 3031, the closest of the three targets and thus the galaxy for which the smallest spatial scales can be explored. The local star formation rate, as gauged by Hα emission, is shown to strongly correlate with local infrared fluxes and colors. If the galaxy-to-galaxy variations in spectral energy distributions seen in our sample are representative of the range present at high redshift then extrapolations of total infrared luminosities and star formation rates from the observed 24 \\micron\\ flux will be uncertain at the factor-of-five level. The corresponding uncertainties in the redshifted 8.0 \\micron\\ flux (e.g. observed 24 \\micron\\ flux for a z = 2 source) are factors of 5--10. Considerable caution should be used when interpreting such extrapolated infrared luminosities. Support for this work, part of the Spitzer Space Telescope Legacy Science Program, was provided by NASA through Contract Number 1224769 issued by the Jet Propulsion Laboratory, California Institute of Technology under NASA contract 1407.

  5. Smart Operations in Distributed Energy Resources System

    NASA Astrophysics Data System (ADS)

    Wei, Li; Jie, Shu; Zhang-XianYong; Qing, Zhou

    Smart grid capabilities are being proposed to help solve the challenges concerning system operations due to that the trade-offs between energy and environmental needs will be constantly negotiated while a reliable supply of electricity needs even greater assurance in case of that threats of disruption have risen. This paper mainly explores models for distributed energy resources system (DG, storage, and load),and also reviews the evolving nature of electricity markets to deal with this complexity and a change of emphasis on signals from these markets to affect power system control. Smart grid capabilities will also impact reliable operations, while cyber security issues must be solved as a culture change that influences all system design, implementation, and maintenance. Lastly, the paper explores significant questions for further research and the need for a simulation environment that supports such investigation and informs deployments to mitigate operational issues as they arise.

  6. Distributed Energy Resources Market Diffusion Model

    SciTech Connect

    Maribu, Karl Magnus; Firestone, Ryan; Marnay, Chris; Siddiqui,Afzal S.

    2006-06-16

    Distributed generation (DG) technologies, such as gas-fired reciprocating engines and microturbines, have been found to be economically beneficial in meeting commercial-sector electrical, heating, and cooling loads. Even though the electric-only efficiency of DG is lower than that offered by traditional central stations, combined heat and power (CHP) applications using recovered heat can make the overall system energy efficiency of distributed energy resources (DER) greater. From a policy perspective, however, it would be useful to have good estimates of penetration rates of DER under various economic and regulatory scenarios. In order to examine the extent to which DER systems may be adopted at a national level, we model the diffusion of DER in the US commercial building sector under different technical research and technology outreach scenarios. In this context, technology market diffusion is assumed to depend on the system's economic attractiveness and the developer's knowledge about the technology. The latter can be spread both by word-of-mouth and by public outreach programs. To account for regional differences in energy markets and climates, as well as the economic potential for different building types, optimal DER systems are found for several building types and regions. Technology diffusion is then predicted via two scenarios: a baseline scenario and a program scenario, in which more research improves DER performance and stronger technology outreach programs increase DER knowledge. The results depict a large and diverse market where both optimal installed capacity and profitability vary significantly across regions and building types. According to the technology diffusion model, the West region will take the lead in DER installations mainly due to high electricity prices, followed by a later adoption in the Northeast and Midwest regions. Since the DER market is in an early stage, both technology research and outreach programs have the potential to increase

  7. Suprathermal plasma analyzer for the measurement of low-energy electron distribution in the ionosphere

    SciTech Connect

    Shimoyama, M.; Yau, A. W.; Oyama, K.-I.; Abe, T.

    2011-07-15

    It is commonly believed that an energy transfer from thermal to suprathermal electrons (energy budget of the ionosphere. However, observation of electron energy spectrum in this energy range is quite limited because of technical difficulties of measurement. We have developed an instrument to measure electron energy distribution from thermal to suprathermal energy continuously with high-energy resolution of about 0.15 eV. The measurement principle is based on the combination of a retarding potential analyzer with a channel electron multiplier (CEM) and the Druyvesteyn method, which derives energy distribution from the current-voltage characteristics. The capability of detecting plasma space potential enables absolute calibration of electron energy. The instrument with a small vacuum pump, which is required for the CEM to work in low-vacuum region, was first successfully tested by a sounding rocket S-310-37 in the ionospheric E region. The instrument is expected to provide new opportunities to measure energy distribution of thermal and non-thermal electrons in low-density plasma, where a Langmuir probe cannot measure electron temperature because of low plasma density.

  8. Suprathermal plasma analyzer for the measurement of low-energy electron distribution in the ionosphere.

    PubMed

    Shimoyama, M; Oyama, K-I; Abe, T; Yau, A W

    2011-07-01

    It is commonly believed that an energy transfer from thermal to suprathermal electrons (energy budget of the ionosphere. However, observation of electron energy spectrum in this energy range is quite limited because of technical difficulties of measurement. We have developed an instrument to measure electron energy distribution from thermal to suprathermal energy continuously with high-energy resolution of about 0.15 eV. The measurement principle is based on the combination of a retarding potential analyzer with a channel electron multiplier (CEM) and the Druyvesteyn method, which derives energy distribution from the current-voltage characteristics. The capability of detecting plasma space potential enables absolute calibration of electron energy. The instrument with a small vacuum pump, which is required for the CEM to work in low-vacuum region, was first successfully tested by a sounding rocket S-310-37 in the ionospheric E region. The instrument is expected to provide new opportunities to measure energy distribution of thermal and non-thermal electrons in low-density plasma, where a Langmuir probe cannot measure electron temperature because of low plasma density. PMID:21806205

  9. Suprathermal plasma analyzer for the measurement of low-energy electron distribution in the ionosphere

    NASA Astrophysics Data System (ADS)

    Shimoyama, M.; Oyama, K.-I.; Abe, T.; Yau, A. W.

    2011-07-01

    It is commonly believed that an energy transfer from thermal to suprathermal electrons (energy budget of the ionosphere. However, observation of electron energy spectrum in this energy range is quite limited because of technical difficulties of measurement. We have developed an instrument to measure electron energy distribution from thermal to suprathermal energy continuously with high-energy resolution of about 0.15 eV. The measurement principle is based on the combination of a retarding potential analyzer with a channel electron multiplier (CEM) and the Druyvesteyn method, which derives energy distribution from the current-voltage characteristics. The capability of detecting plasma space potential enables absolute calibration of electron energy. The instrument with a small vacuum pump, which is required for the CEM to work in low-vacuum region, was first successfully tested by a sounding rocket S-310-37 in the ionospheric E region. The instrument is expected to provide new opportunities to measure energy distribution of thermal and non-thermal electrons in low-density plasma, where a Langmuir probe cannot measure electron temperature because of low plasma density.

  10. Tetrahedral cluster and pseudo molecule: New approaches to Calculate Absolute Surface Energy of Zinc Blende (111)/(-1-1-1) Surface

    NASA Astrophysics Data System (ADS)

    Zhang, Yiou; Zhang, Jingzhao; Tse, Kinfai; Wong, Lun; Chan, Chunkai; Deng, Bei; Zhu, Junyi

    Determining accurate absolute surface energies for polar surfaces of semiconductors has been a great challenge in decades. Here, we propose pseudo-hydrogen passivation to calculate them, using density functional theory approaches. By calculating the energy contribution from pseudo-hydrogen using either a pseudo molecule method or a tetrahedral cluster method, we obtained (111)/(-1-1-1) surfaces energies of Si, GaP, GaAs, and ZnS with high self-consistency. Our findings may greatly enhance the basic understandings of different surfaces and lead to novel strategies in the crystal growth. We would like to thank Su-huai Wei for helpful discussions. Computing resources were provided by the High Performance Cluster Computing Centre, Hong Kong Baptist University. This work was supported by the start-up funding and direct Grant with the Project.

  11. Determination of the surface energy distributions of different processed lactose.

    PubMed

    Thielmann, Frank; Burnett, Daniel J; Heng, Jerry Y Y

    2007-11-01

    Particulate interactions between drug and lactose carrier in dry powder inhaler formulations are affected by the heterogenous energy distribution on the surface of the individual compounds. A new method based on Inverse Gas Chromatography at finite concentration is applied to study the energy heterogeneity of untreated, milled, and recrystallized lactose of similar particle size distribution. Energy distributions for the dispersive surface energy and the specific free energy of ethanol are obtained. Milling causes an increase in surface energy due to formation of amorphous regions. Untreated and recrystallized materials have similar surface energies at low surface coverages but show clear differences in energy distribution. PMID:18058321

  12. Coordinated Collaboration between Heterogeneous Distributed Energy Resources

    DOE PAGESBeta

    Abdollahy, Shahin; Lavrova, Olga; Mammoli, Andrea

    2014-01-01

    A power distribution feeder, where a heterogeneous set of distributed energy resources is deployed, is examined by simulation. The energy resources include PV, battery storage, natural gas GenSet, fuel cells, and active thermal storage for commercial buildings. The resource scenario considered is one that may exist in a not too distant future. Two cases of interaction between different resources are examined. One interaction involves a GenSet used to partially offset the duty cycle of a smoothing battery connected to a large PV system. The other example involves the coordination of twenty thermal storage devices, each associated with a commercial building.more » Storage devices are intended to provide maximum benefit to the building, but it is shown that this can have a deleterious effect on the overall system, unless the action of the individual storage devices is coordinated. A network based approach is also introduced to calculate some type of effectiveness metric to all available resources which take part in coordinated operation. The main finding is that it is possible to achieve synergy between DERs on a system; however this required a unified strategy to coordinate the action of all devices in a decentralized way.« less

  13. Advanced Energy Storage Management in Distribution Network

    SciTech Connect

    Liu, Guodong; Ceylan, Oguzhan; Xiao, Bailu; Starke, Michael R; Ollis, T Ben; King, Daniel J; Irminger, Philip; Tomsovic, Kevin

    2016-01-01

    With increasing penetration of distributed generation (DG) in the distribution networks (DN), the secure and optimal operation of DN has become an important concern. In this paper, an iterative mixed integer quadratic constrained quadratic programming model to optimize the operation of a three phase unbalanced distribution system with high penetration of Photovoltaic (PV) panels, DG and energy storage (ES) is developed. The proposed model minimizes not only the operating cost, including fuel cost and purchasing cost, but also voltage deviations and power loss. The optimization model is based on the linearized sensitivity coefficients between state variables (e.g., node voltages) and control variables (e.g., real and reactive power injections of DG and ES). To avoid slow convergence when close to the optimum, a golden search method is introduced to control the step size and accelerate the convergence. The proposed algorithm is demonstrated on modified IEEE 13 nodes test feeders with multiple PV panels, DG and ES. Numerical simulation results validate the proposed algorithm. Various scenarios of system configuration are studied and some critical findings are concluded.

  14. Absolute dose measurements by means of a small cylindrical ionization chamber for very high dose per pulse high energy electron beams

    SciTech Connect

    Karaj, E.; Righi, S.; Di Martino, F.

    2007-03-15

    Very high dose per pulse (3-13 cGy/pulse) high energy electron beams are currently produced by special linear accelerators (linac) dedicated to Intra Operative Radiation Therapy (IORT). The electron beams produced by such linacs are collimated by special Perspex applicators of various size and cylindrically shaped. The biggest problems from the dosimetric point of view are caused by the high dose-per-pulse values and the use of inclined applicators. In this work measurements of absolute dose for the inclined applicators were done by using a small cylindrical ionization chamber, type CC01 (Wellhofer), a parallel plane ionization chamber type Markus (PTW 23343) and radiochromic films type EBT. We show a method which allows calculating the quality correction factors for CC01 chamber with an uncertainty of 1% and the absolute dose value for the inclined applicators using CC01 with an uncertainty of 3.1% for electron beams of energy of 6 and 7 MeV produced by the linac dedicated to IORT Novac7.

  15. Energy Efficiency of Distributed Environmental Control Systems

    SciTech Connect

    Khalifa, H. Ezzat; Isik, Can; Dannenhoffer, John F. III

    2011-02-23

    In this report, we present an analytical evaluation of the potential of occupant-regulated distributed environmental control systems (DECS) to enhance individual occupant thermal comfort in an office building with no increase, and possibly even a decrease in annual energy consumption. To this end we developed and applied several analytical models that allowed us to optimize comfort and energy consumption in partitioned office buildings equipped with either conventional central HVAC systems or occupant-regulated DECS. Our approach involved the following interrelated components: 1. Development of a simplified lumped-parameter thermal circuit model to compute the annual energy consumption. This was necessitated by the need to perform tens of thousands of optimization calculations involving different US climatic regions, and different occupant thermal preferences of a population of ~50 office occupants. Yearly transient simulations using TRNSYS, a time-dependent building energy modeling program, were run to determine the robustness of the simplified approach against time-dependent simulations. The simplified model predicts yearly energy consumption within approximately 0.6% of an equivalent transient simulation. Simulations of building energy usage were run for a wide variety of climatic regions and control scenarios, including traditional “one-size-fits-all” (OSFA) control; providing a uniform temperature to the entire building, and occupant-selected “have-it-your-way” (HIYW) control with a thermostat at each workstation. The thermal model shows that, un-optimized, DECS would lead to an increase in building energy consumption between 3-16% compared to the conventional approach depending on the climate regional and personal preferences of building occupants. Variations in building shape had little impact in the relative energy usage. 2. Development of a gradient-based optimization method to minimize energy consumption of DECS while keeping each occupant

  16. Characterizing the energy distribution around GPR antennas

    NASA Astrophysics Data System (ADS)

    Diamanti, Nectaria; Annan, A. Peter

    2013-12-01

    Antenna height, orientation, shielding and subsurface properties all impact GPR responses. Although the basic concepts are generally understood, clarifying the key relationships can aid interpretation. Our long term goal is to develop easily parameterized models of transmitting and receiving components of GPR systems that will provide for quantitative interpretation of data acquired with real systems. Our first step was to develop modeling capacity and response presentation tools to help with development; the initial results have been both informative and forced a better understanding of near and far field. We are using three-dimensional (3D) finite-difference time-domain (FDTD) modeling. Model results can be presented in a variety of forms. In this paper, we focus on presenting the emitted energy characteristics and use radiation pattern display format for infinitesimal dipoles, resistively loaded dipoles and shielded dipoles. Patterns are computed for a range of environments such as free-space and over loss-less half-spaces with various properties. The energy distribution patterns are presented to investigate the behavior with distance away from the transmitter feed point, and as a function of height above the ground surface. The numerical simulations provide expected insights plus demonstrate the benefit of ground-coupling and the impact of shielding on GPR responses. Further, using the total radiated energy parameter is a novel method for displaying directivity, for GPR transient emissions.

  17. Stable Electron Beams With Low Absolute Energy Spread From a LaserWakefield Accelerator With Plasma Density Ramp Controlled Injection

    SciTech Connect

    Geddes, Cameron G.R.; Cormier-Michel, E.; Esarey, E.; Leemans,W.P.; Nakamura, K.; Panasenko, D.; Plateau, Guillaume R.; Schroeder, CarlB.; Toth, Csaba; Cary, J.R.

    2007-06-25

    Laser wakefield accelerators produce accelerating gradientsup to hundreds of GeV/m, and recently demonstrated 1-10 MeV energy spreadat energies up to 1 GeV using electrons self-trapped from the plasma.Controlled injection and staging may further improve beam quality bycircumventing tradeoffs between energy, stability, and energyspread/emittance. We present experiments demonstrating production of astable electron beam near 1 MeV with hundred-keV level energy spread andcentral energy stability by using the plasma density profile to controlselfinjection, and supporting simulations. Simulations indicate that suchbeams can be post accelerated to high energies,potentially reducingmomentum spread in laser acceleratorsby 100-fold or more.

  18. Classical trajectory study of internal energy distributions in unimolecular processes

    NASA Technical Reports Server (NTRS)

    Mcdonald, J. D.; Marcus, R. A.

    1976-01-01

    Energy flow in a molecular system such as CD3Cl or CD3H representing a chemical activation experiment is studied by the method of classical trajectories. A correlation function method is used to obtain energy distributions before and after the breakup of the activated molecule. The energy distribution in the final product is found to be randomly distributed for a surface with no exit channel barrier or strong intermode couplings. Nonrandom energy distributions result when these special forces are present. Product channel barriers result in an excess of translational energy and exit channel intermode couplings result in nonrandom vibrational distributions.

  19. Distributed activation energy model parameters of some Turkish coals

    SciTech Connect

    Gunes, M.; Gunes, S.K.

    2008-07-01

    A multi-reaction model based on distributed activation energy has been applied to some Turkish coals. The kinetic parameters of distributed activation energy model were calculated via computer program developed for this purpose. It was observed that the values of mean of activation energy distribution vary between 218 and 248 kJ/mol, and the values of standard deviation of activation energy distribution vary between 32 and 70 kJ/mol. The correlations between kinetic parameters of the distributed activation energy model and certain properties of coal have been investigated.

  20. Advanced Energy Efficiency and Distributed Renewables

    NASA Astrophysics Data System (ADS)

    Lovins, Amory

    2007-04-01

    The US now wrings twice the GDP from each unit of energy that it did in 1975. Reduced energy intensity since then now provides more than twice as much service as burning oil does. Yet still more efficient end-use of energy -- explained more fully in a companion workshop offered at 1245 -- is the largest, fastest, cheapest, most benign, least understood, and least harnessed energy resource available. For example, existing technologies could save half of 2000 US oil and gas and three-fourths of US electricity, at lower cost than producing and delivering that energy from existing facilities. Saving half the oil through efficiency and replacing the other half with saved natural gas and advanced biofuels would cost an average of only 15/barrel and could eliminate US oil use by the 2040s, led by business for profit. Efficiency techniques and ways to combine and apply them continue to improve faster than they're applied, so the ``efficiency resource'' is becoming ever larger and cheaper. As for electricity, ``micropower'' (distributed renewables plus low-carbon cogeneration) is growing so quickly that by 2005 it provided a sixth of the world's electricity and a third of its new electricity, and was adding annually 4x the capacity and 11x the capacity added by nuclear power, which it surpassed in capacity in 2002 and in output in 2006. Together, micropower and ``negawatts'' (saved electricity) now provide upwards half the world's new electrical services, due to their far lower cost and lower financial risk than the central thermal power stations that still dominate policy discussions. For oil and electricity, each of which adds about two-fifths of the world's energy-related carbon dioxide emissions, efficiency plus competitive alternative supplies can stabilize the earth's climate at a profit, as well as solving the oil and (largely) the nuclear proliferation problems. Conversely, costlier and slower options, notably nuclear power, would displace less carbon emission per

  1. Photoelectric spectrophotometry of OQ 172 and OH 471. [spectral energy distributions for red shift quasars

    NASA Technical Reports Server (NTRS)

    Oke, J. B.

    1974-01-01

    Absolute spectral energy distributions for the large redshift quasars OQ 172 and OH 471 are discussed along with similar data for two other quasars 4C05.34 and PHL 957. Assuming cosmological redshifts, OQ 172 and OH 471 are not as luminous as PHL 957. If these quasars are basically similar and if radiative processes dominate, the strength of Ly alpha and the behavior of the continuum at the Lyman limit strongly suggest that these objects consist of a central ionizing source surrounded by discrete clouds, filaments or a gaseous structure such as a disk. This gaseous matter does not cover the whole solid angle surrounding the source.

  2. Confined energy distribution for charged particle beams

    DOEpatents

    Jason, Andrew J.; Blind, Barbara

    1990-01-01

    A charged particle beam is formed to a relatively larger area beam which is well-contained and has a beam area which relatively uniformly deposits energy over a beam target. Linear optics receive an accelerator beam and output a first beam with a first waist defined by a relatively small size in a first dimension normal to a second dimension. Nonlinear optics, such as an octupole magnet, are located about the first waist and output a second beam having a phase-space distribution which folds the beam edges along the second dimension toward the beam core to develop a well-contained beam and a relatively uniform particle intensity across the beam core. The beam may then be expanded along the second dimension to form the uniform ribbon beam at a selected distance from the nonlinear optics. Alternately, the beam may be passed through a second set of nonlinear optics to fold the beam edges in the first dimension. The beam may then be uniformly expanded along the first and second dimensions to form a well-contained, two-dimensional beam for illuminating a two-dimensional target with a relatively uniform energy deposition.

  3. Role of Modeling When Designing for Absolute Energy Use Intensity Requirements in a Design-Build Framework: Preprint

    SciTech Connect

    Hirsch, A.; Pless, S.; Guglielmetti, R.; Torcellini, P. A.; Okada, D.; Antia, P.

    2011-03-01

    The Research Support Facility was designed to use half the energy of an equivalent minimally code-compliant building, and to produce as much renewable energy as it consumes on an annual basis. These energy goals and their substantiation through simulation were explicitly included in the project's fixed firm price design-build contract. The energy model had to be continuously updated during the design process and to match the final building as-built to the greatest degree possible. Computer modeling played a key role throughout the design process and in verifying that the contractual energy goals would be met within the specified budget. The main tool was a whole building energy simulation program. Other models were used to provide more detail or to complement the whole building simulation tool. Results from these specialized models were fed back into the main whole building simulation tool to provide the most accurate possible inputs for annual simulations. This paper will detail the models used in the design process and how they informed important program and design decisions on the path from preliminary design to the completed building.

  4. Measurements of Ion Energy and Ion Flux Distributions in Inductively Coupled Plasmas in CF4/O2/Ar Mixtures

    NASA Technical Reports Server (NTRS)

    Rao, M. V. V. S.; Kim, J. S.; Cappelli, M. A.; Sharma, Surendra; Partridge, Harry (Technical Monitor)

    1999-01-01

    We report mass spectrometric studies of energy distributions and absolute concentrations of ions generated in CF4/O2/Ar inductively coupled rf plasmas. The ions were collected through a 100 mm orifice in the grounded and water cooled lower electrode in a GEC cell configuration. The measurements were made at gas pressures in the 10-50 mTorr range and rf coil power in the 100-300 W range. The observed ions are CF3(+), CF2(+), CF(+), C(+), F(+), COF(+), CO(+), O2(+), and O(+). The relative abundance of these ions varies with pressure and rf power. The energy distribution and absolute concentrations are correlated with electron number density and floating plasma potential measured by a compensated Langmuir probe.

  5. Small Deflection Energy Analyzer for Energy and Angular Distributions

    NASA Technical Reports Server (NTRS)

    Herrero, Federico A.

    2009-01-01

    The development of the Small Deflection Energy Analyzer (SDEA) charged-particle spectrometer for energy and angle distributions responds to a longstanding need to measure the wind velocity vector in Earth s thermosphere, and to obtain the ion-drift vector in the ionosphere. The air and ions above 120 km are endowed with bulk velocities and temperatures just like air near the ground, but with separate spatial and temporal variations. It is important to understand these not only for study of the physics and chemistry of the Sun-Earth connection, but also for spacecraft orbit predictions, and communications through the ionosphere. The SDEA consists of a pair of parallel conducting plates separated by a small distance, with an entrance slit on one end, and an exit slit on the other. A voltage applied to these plates develops an electric field between the plates, and this field deflects ions passing through it. If an ion has too little energy, it will strike one of the plates. If it has too much, it will strike the back wall. An ion with the amount of energy being searched for will have its trajectory bent just enough to exit the back slit. The SDEA units are compact, rectangular, and operate with low voltages. The units can be built up into small arrays. These arrays could be used either to widen the field of view or to sharpen an existing one. This approach can also be used to obtain angular distributions in two planes simultaneously, thus cutting down the ion source power requirements in half. This geometry has enabled a new mass-spectrometer concept that can provide miniaturized mass spectrometers for use in industrial plants, air-pollution monitoring, and noxious-gas detection.

  6. Absolute detection efficiency of a microchannel plate detector to X rays in the 1-100 KeV energy range

    NASA Astrophysics Data System (ADS)

    Burginyon, Gary A.; Jacoby, Barry A.; Wobser, James K.; Ernst, Richard; Ancheta, Dione S.; Tirsell, Kenneth G.

    1993-02-01

    There is little information in the literature on the performance of working micro-channel plate (MCP) detectors at high x-ray energies. We have measured the absolute efficiency of a microchannel-plate-intensified, subnanosecond, one dimensional imaging x-ray detector developed at LLNL in the 1 to 100 keV range and at 1.25 MeV. The detector consists of a gold photocathode deposited on the front surface of the MCP (optimized for Ni K(subscript (alpha) ) x rays) to convert x rays to electrons, an MCP to amplify the electrons, and a fast In:CdS phosphor that converts the electron's kinetic energy to light. The phosphor is coated on a fiber-optic faceplate to transmit the light out of the vacuum system. Electrostatic focusing electrodes compress the electron current out of the MCP in one dimension while preserving spatial resolution in the other. The calibration geometry, dictated by a recent experiment, required grazing incidence x rays (15.6 degree(s)) onto the MCP detector in order to maximize deliverable current. The experiment also used a second detector made up of 0.071 in. thick BC422 plastic scintillator material from the Bicron Corporation. We compare the absolute efficiencies of these two detectors in units of optical W/cm(superscript 2) into 4 (pi) per x ray W/cm(superscript 2) incident. At 7.47 keV and 900 volts MCP bias, the MCP detector delivers approximately 1400 times more light than the scintillator detector.

  7. Controlling electron energy distributions for plasma technologies

    NASA Astrophysics Data System (ADS)

    Kushner, Mark

    2009-10-01

    The basic function of low temperature plasmas in society benefiting technologies is to channel power into specific modes of atoms and molecules to excite desired states or produce specified radicals. This functionality ultimately depends on the ability to craft an electron energy distribution (EED) to match cross sections. Given electric fields, frequencies, gas mixtures and pressures, predicting EEDs and excitation rates can in large part be reliably done. The inverse problem, specifying the conditions that produce a given EED, is less well understood. Early strategies to craft EEDs include adjusting gas mixtures, such as the rare gas-Hg mixtures in fluorescent lamps, and externally sustained discharges, such as electron-beam sustained plasmas for molecular lasers. More recent strategies include spiker-sustainer circuitry which produces desired EEDs in non-self-sustained plasmas; and adjusting frequency in capacitively coupled plasmas. In this talk, past strategies for customizing EEDs in low pressure plasmas will be reviewed and prospects for improved control of plasma kinetics will be discussed using results from 2-dimensional computer models.

  8. Evolution of Quasar Spectral Energy Distributions

    NASA Astrophysics Data System (ADS)

    Schilling, Amanda; Kennefick, J.; Mahmood, A.

    2012-05-01

    A common practice when formulating quasar luminosity functions (QLF) has been to adopt an average spectral index, $\\alpha$, for the sample even though it is well known that quasars exhibit a broad range of spectral energy distributions (SED.) We have investigated the possible evolution of $\\alpha$ as a function of redshift, as any evolution in this parameter would introduce or mask evolution in the QLF. We imaged 103 Sloan Digital Sky Survey (SDSS) quasars in the optical and near-infrared bands, near in time to mitigate the effects of variability, in three redshift bins centered at $z\\approx 1.9$, $2.7$, and $4.0$, corresponding to look-back times of 10-12 billion years. We present restframe UV-optical SED’s and spectral indices and discuss possible evolution in our sample. We also use single epoch spectra of the quasars to estimate the mass of the central black hole and discuss possible correlations of quasar properties such as mass, luminosity, and spectral shape.

  9. A measurement of the absolute energy spectra of galactic cosmic rays during the 1976-77 solar minimum

    NASA Technical Reports Server (NTRS)

    Derrickson, J. H.; Parnell, T. A.; Austin, R. W.; Selig, W. J.; Gregory, J. C.

    1992-01-01

    An instrument designed to measure elemental cosmic ray abundances from boron to nickel in the energy region 0.5-2.0 GeV/nucl was flown on a high altitude balloon from Sioux Falls, South Dakota, on 30 September through 1 October 1976 at an average atmospheric depth of about 5 g/sq cm. Differential energy spectra of B, C, N, O, Ne, Mg, Si and Fe, extrapolated to the top of the atmosphere, were measured. The float altitude exposure of 17 h ended near Alpena, Michigan. The flight trajectory maintained a north easterly heading out of Sioux Falls traversing the upper midwest region between 84 and 97 deg west longitude while remaining between 43.5 and 45 deg north latitude. The maximum vertical cut-off for this flight path was 1.77 GV or 0.35 GeV/nucl.

  10. Absolute neutrino mass measurements

    NASA Astrophysics Data System (ADS)

    Wolf, Joachim

    2011-10-01

    The neutrino mass plays an important role in particle physics, astrophysics and cosmology. In recent years the detection of neutrino flavour oscillations proved that neutrinos carry mass. However, oscillation experiments are only sensitive to the mass-squared difference of the mass eigenvalues. In contrast to cosmological observations and neutrino-less double beta decay (0v2β) searches, single β-decay experiments provide a direct, model-independent way to determine the absolute neutrino mass by measuring the energy spectrum of decay electrons at the endpoint region with high accuracy. Currently the best kinematic upper limits on the neutrino mass of 2.2eV have been set by two experiments in Mainz and Troitsk, using tritium as beta emitter. The next generation tritium β-experiment KATRIN is currently under construction in Karlsruhe/Germany by an international collaboration. KATRIN intends to improve the sensitivity by one order of magnitude to 0.2eV. The investigation of a second isotope (137Rh) is being pursued by the international MARE collaboration using micro-calorimeters to measure the beta spectrum. The technology needed to reach 0.2eV sensitivity is still in the R&D phase. This paper reviews the present status of neutrino-mass measurements with cosmological data, 0v2β decay and single β-decay.

  11. Absolute neutrino mass measurements

    SciTech Connect

    Wolf, Joachim

    2011-10-06

    The neutrino mass plays an important role in particle physics, astrophysics and cosmology. In recent years the detection of neutrino flavour oscillations proved that neutrinos carry mass. However, oscillation experiments are only sensitive to the mass-squared difference of the mass eigenvalues. In contrast to cosmological observations and neutrino-less double beta decay (0v2{beta}) searches, single {beta}-decay experiments provide a direct, model-independent way to determine the absolute neutrino mass by measuring the energy spectrum of decay electrons at the endpoint region with high accuracy.Currently the best kinematic upper limits on the neutrino mass of 2.2eV have been set by two experiments in Mainz and Troitsk, using tritium as beta emitter. The next generation tritium {beta}-experiment KATRIN is currently under construction in Karlsruhe/Germany by an international collaboration. KATRIN intends to improve the sensitivity by one order of magnitude to 0.2eV. The investigation of a second isotope ({sup 137}Rh) is being pursued by the international MARE collaboration using micro-calorimeters to measure the beta spectrum. The technology needed to reach 0.2eV sensitivity is still in the R and D phase. This paper reviews the present status of neutrino-mass measurements with cosmological data, 0v2{beta} decay and single {beta}-decay.

  12. Gas-Fired Distributed Energy Resource Technology Characterizations

    SciTech Connect

    Goldstein, L.; Hedman, B.; Knowles, D.; Freedman, S. I.; Woods, R.; Schweizer, T.

    2003-11-01

    The U. S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE) is directing substantial programs in the development and encouragement of new energy technologies. Among them are renewable energy and distributed energy resource technologies. As part of its ongoing effort to document the status and potential of these technologies, DOE EERE directed the National Renewable Energy Laboratory to lead an effort to develop and publish Distributed Energy Technology Characterizations (TCs) that would provide both the department and energy community with a consistent and objective set of cost and performance data in prospective electric-power generation applications in the United States. Toward that goal, DOE/EERE - joined by the Electric Power Research Institute (EPRI) - published the Renewable Energy Technology Characterizations in December 1997.As a follow-up, DOE EERE - joined by the Gas Research Institute - is now publishing this document, Gas-Fired Distributed Energy Resource Technology Characterizations.

  13. Cluster-continuum quasichemical theory calculation of the lithium ion solvation in water, acetonitrile and dimethyl sulfoxide: an absolute single-ion solvation free energy scale.

    PubMed

    Carvalho, Nathalia F; Pliego, Josefredo R

    2015-10-28

    Absolute single-ion solvation free energy is a very useful property for understanding solution phase chemistry. The real solvation free energy of an ion depends on its interaction with the solvent molecules and on the net potential inside the solute cavity. The tetraphenyl arsonium-tetraphenyl borate (TATB) assumption as well as the cluster-continuum quasichemical theory (CC-QCT) approach for Li(+) solvation allows access to a solvation scale excluding the net potential. We have determined this free energy scale investigating the solvation of the lithium ion in water (H2O), acetonitrile (CH3CN) and dimethyl sulfoxide (DMSO) solvents via the CC-QCT approach. Our calculations at the MP2 and MP4 levels with basis sets up to the QZVPP+diff quality, and including solvation of the clusters and solvent molecules by the dielectric continuum SMD method, predict the solvation free energy of Li(+) as -116.1, -120.6 and -123.6 kcal mol(-1) in H2O, CH3CN and DMSO solvents, respectively (1 mol L(-1) standard state). These values are compatible with the solvation free energy of the proton of -253.4, -253.2 and -261.1 kcal mol(-1) in H2O, CH3CN and DMSO solvents, respectively. Deviations from the experimental TATB scale are only 1.3 kcal mol(-1) in H2O and 1.8 kcal mol(-1) in DMSO solvents. However, in the case of CH3CN, the deviation reaches a value of 9.2 kcal mol(-1). The present study suggests that the experimental TATB scale is inconsistent for CH3CN. A total of 125 values of the solvation free energy of ions in these three solvents were obtained. These new data should be useful for the development of theoretical solvation models. PMID:26395146

  14. An energy decomposition analysis for intermolecular interactions from an absolutely localized molecular orbital reference at the coupled-cluster singles and doubles level

    SciTech Connect

    Azar, R. Julian; Head-Gordon, Martin

    2012-01-14

    We propose a wave function-based method for the decomposition of intermolecular interaction energies into chemically-intuitive components, isolating both mean-field- and explicit correlation-level contributions. We begin by solving the locally-projected self-consistent field for molecular interactions equations for a molecular complex, obtaining an intramolecularly polarized reference of self-consistently optimized, absolutely-localized molecular orbitals (ALMOs), determined with the constraint that each fragment MO be composed only of atomic basis functions belonging to its own fragment. As explicit inter-electronic correlation is integral to an accurate description of weak forces underlying intermolecular interaction potentials, namely, coordinated fluctuations in weakly interacting electronic densities, we add dynamical correlation to the ALMO polarized reference at the coupled-cluster singles and doubles level, accounting for explicit dispersion and charge-transfer effects, which map naturally onto the cluster operator. We demonstrate the stability of energy components with basis set extension, follow the hydrogen bond-breaking coordinate in the C{sub s}-symmetry water dimer, decompose the interaction energies of dispersion-bound rare gas dimers and other van der Waals complexes, and examine charge transfer-dominated donor-acceptor interactions in borane adducts. We compare our results with high-level calculations and experiment when possible.

  15. Absolute solvation free energy of Li{sup +} and Na{sup +} ions in dimethyl sulfoxide solution: A theoretical ab initio and cluster-continuum model study

    SciTech Connect

    Westphal, Eduard; Pliego, Josefredo R. Jr.

    2005-08-15

    The solvation of the lithium and sodium ions in dimethyl sulfoxide solution was theoretically investigated using ab initio calculations coupled with the hybrid cluster-continuum model, a quasichemical theory of solvation. We have investigated clusters of ions with up to five dimethyl sulfoxide (DMSO) molecules, and the bulk solvent was described by a dielectric continuum model. Our results show that the lithium and sodium ions have four and five DMSO molecules into the first coordination shell, and the calculated solvation free energies are -135.5 and -108.6 kcal mol{sup -1}, respectively. These data suggest a solvation free energy value of -273.2 kcal mol{sup -1} for the proton in dimethyl sulfoxide solution, a value that is more negative than the present uncertain experimental value. This and previous studies on the solvation of ions in water solution indicate that the tetraphenylarsonium tetraphenylborate assumption is flawed and the absolute value of the free energy of transfer of ions from water to DMSO solution is higher than the present experimental values.

  16. A whole-path importance-sampling scheme for Feynman path integral calculations of absolute partition functions and free energies.

    PubMed

    Mielke, Steven L; Truhlar, Donald G

    2016-01-21

    Using Feynman path integrals, a molecular partition function can be written as a double integral with the inner integral involving all closed paths centered at a given molecular configuration, and the outer integral involving all possible molecular configurations. In previous work employing Monte Carlo methods to evaluate such partition functions, we presented schemes for importance sampling and stratification in the molecular configurations that constitute the path centroids, but we relied on free-particle paths for sampling the path integrals. At low temperatures, the path sampling is expensive because the paths can travel far from the centroid configuration. We now present a scheme for importance sampling of whole Feynman paths based on harmonic information from an instantaneous normal mode calculation at the centroid configuration, which we refer to as harmonically guided whole-path importance sampling (WPIS). We obtain paths conforming to our chosen importance function by rejection sampling from a distribution of free-particle paths. Sample calculations on CH4 demonstrate that at a temperature of 200 K, about 99.9% of the free-particle paths can be rejected without integration, and at 300 K, about 98% can be rejected. We also show that it is typically possible to reduce the overhead associated with the WPIS scheme by sampling the paths using a significantly lower-order path discretization than that which is needed to converge the partition function. PMID:26801023

  17. A whole-path importance-sampling scheme for Feynman path integral calculations of absolute partition functions and free energies

    NASA Astrophysics Data System (ADS)

    Mielke, Steven L.; Truhlar, Donald G.

    2016-01-01

    Using Feynman path integrals, a molecular partition function can be written as a double integral with the inner integral involving all closed paths centered at a given molecular configuration, and the outer integral involving all possible molecular configurations. In previous work employing Monte Carlo methods to evaluate such partition functions, we presented schemes for importance sampling and stratification in the molecular configurations that constitute the path centroids, but we relied on free-particle paths for sampling the path integrals. At low temperatures, the path sampling is expensive because the paths can travel far from the centroid configuration. We now present a scheme for importance sampling of whole Feynman paths based on harmonic information from an instantaneous normal mode calculation at the centroid configuration, which we refer to as harmonically guided whole-path importance sampling (WPIS). We obtain paths conforming to our chosen importance function by rejection sampling from a distribution of free-particle paths. Sample calculations on CH4 demonstrate that at a temperature of 200 K, about 99.9% of the free-particle paths can be rejected without integration, and at 300 K, about 98% can be rejected. We also show that it is typically possible to reduce the overhead associated with the WPIS scheme by sampling the paths using a significantly lower-order path discretization than that which is needed to converge the partition function.

  18. The ultraviolet energy distributions of late A stars

    NASA Technical Reports Server (NTRS)

    Boehm-Vitense, E.

    1981-01-01

    Observed late A star energy distributions for the wavelength range 1400-2500 A are compared. No difference is found between energy distributions of Am stars and those of normal slowly rotating A stars. The fluxes of rapidly rotating stars, however, appear to be increased for wavelengths smaller than 1530 A; this cannot be understood as an effect of pole heating or reduced gravity. In addition, the comparison of the UV energy distributions with model atmosphere energy distributions of Kurucz indicates some problems with the theoretical Si I absorption edges at 1530 A.

  19. Absolute biological needs.

    PubMed

    McLeod, Stephen

    2014-07-01

    Absolute needs (as against instrumental needs) are independent of the ends, goals and purposes of personal agents. Against the view that the only needs are instrumental needs, David Wiggins and Garrett Thomson have defended absolute needs on the grounds that the verb 'need' has instrumental and absolute senses. While remaining neutral about it, this article does not adopt that approach. Instead, it suggests that there are absolute biological needs. The absolute nature of these needs is defended by appeal to: their objectivity (as against mind-dependence); the universality of the phenomenon of needing across the plant and animal kingdoms; the impossibility that biological needs depend wholly upon the exercise of the abilities characteristic of personal agency; the contention that the possession of biological needs is prior to the possession of the abilities characteristic of personal agency. Finally, three philosophical usages of 'normative' are distinguished. On two of these, to describe a phenomenon or claim as 'normative' is to describe it as value-dependent. A description of a phenomenon or claim as 'normative' in the third sense does not entail such value-dependency, though it leaves open the possibility that value depends upon the phenomenon or upon the truth of the claim. It is argued that while survival needs (or claims about them) may well be normative in this third sense, they are normative in neither of the first two. Thus, the idea of absolute need is not inherently normative in either of the first two senses. PMID:23586876

  20. Absolute instability of the Gaussian wake profile

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.; Aggarwal, Arun K.

    1987-01-01

    Linear parallel-flow stability theory has been used to investigate the effect of viscosity on the local absolute instability of a family of wake profiles with a Gaussian velocity distribution. The type of local instability, i.e., convective or absolute, is determined by the location of a branch-point singularity with zero group velocity of the complex dispersion relation for the instability waves. The effects of viscosity were found to be weak for values of the wake Reynolds number, based on the center-line velocity defect and the wake half-width, larger than about 400. Absolute instability occurs only for sufficiently large values of the center-line wake defect. The critical value of this parameter increases with decreasing wake Reynolds number, thereby indicating a shrinking region of absolute instability with decreasing wake Reynolds number. If backflow is not allowed, absolute instability does not occur for wake Reynolds numbers smaller than about 38.

  1. Infrared Spectral Energy Distributions of Nearby Galaxies

    NASA Astrophysics Data System (ADS)

    Dale, D. A.; Bendo, G. J.; Engelbracht, C. W.; Gordon, K. D.; Regan, M. W.; Armus, L.; Cannon, J. M.; Calzetti, D.; Draine, B. T.; Helou, G.; Joseph, R. D.; Kennicutt, R. C.; Li, A.; Murphy, E. J.; Roussel, H.; Walter, F.; Hanson, H. M.; Hollenbach, D. J.; Jarrett, T. H.; Kewley, L. J.; Lamanna, C. A.; Leitherer, C.; Meyer, M. J.; Rieke, G. H.; Rieke, M. J.; Sheth, K.; Smith, J. D. T.; Thornley, M. D.

    2005-11-01

    The Spitzer Infrared Nearby Galaxies Survey (SINGS) is carrying out a comprehensive multiwavelength survey on a sample of 75 nearby galaxies. The 1-850 μm spectral energy distributions (SEDs) are presented using broadband imaging data from Spitzer, 2MASS, ISO, IRAS, and SCUBA. The infrared colors derived from the globally integrated Spitzer data are generally consistent with the previous generation of models that were developed using global data for normal star-forming galaxies, although significant deviations are observed. Spitzer's excellent sensitivity and resolution also allow a detailed investigation of the infrared SEDs for various locations within the three large, nearby galaxies NGC 3031 (M81), NGC 5194 (M51), and NGC 7331. A wide variety of spectral shapes is found within each galaxy, especially for NGC 3031, the closest of the three targets and thus the galaxy for which the smallest spatial scales can be explored. Strong correlations exist between the local star formation rate and the infrared colors fν(70 μm)/fν(160 μm) and fν(24 μm)/fν(160 μm), suggesting that the 24 and 70 μm emission are useful tracers of the local star formation activity level. Preliminary evidence indicates that variations in the 24 μm emission, and not variations in the emission from polycyclic aromatic hydrocarbons at 8 μm, drive the variations in the fν(8.0 μm)/fν(24 μm) colors within NGC 3031, NGC 5194, and NGC 7331. If the galaxy-to-galaxy variations in SEDs seen in our sample are representative of the range present at high redshift, then extrapolations of total infrared luminosities and star formation rates from the observed 24 μm flux will be uncertain at the factor of 5 level (total range). The corresponding uncertainties using the redshifted 8.0 μm flux (e.g., observed 24 μm flux for a z=2 source) are factors of 10-20. Considerable caution should be used when interpreting such extrapolated infrared luminosities.

  2. Two jet energy and rapidity distributions

    SciTech Connect

    Blazey, G.C.; For the D {O} Collaboration

    1992-11-01

    The D0 detector has been recording data at the Tevatron {bar p}p Collider since May 1992. Because the D0 calorimeter is hermetic and has large acceptance it is well suited for semi-exclusive final state jet studies. We present a primary measurement of the distribution d{sup 3}N/dE{sub t1}/d{eta}{sub 1}/d{eta}{sub 2} at {radical}s TeV over a large range of {eta}. The sensitivity of this cross-section to parton momentum distributions and the ability of D0 to discriminate between possible parton distributions is discussed.

  3. Energy Inputs Uncertainty: Total Amount, Distribution and Correlation Between Different Forms of Energy

    NASA Technical Reports Server (NTRS)

    Deng, Yue

    2014-01-01

    Describes solar energy inputs contributing to ionospheric and thermospheric weather processes, including total energy amounts, distributions and the correlation between particle precipitation and Poynting flux.

  4. Energy distribution among reaction products. VII - H + F2.

    NASA Technical Reports Server (NTRS)

    Polanyi, J. C.; Sloan, J. J.

    1972-01-01

    The 'arrested relaxation' variant of the IR chemiluminescence technique is used in a study of the distribution of vibrational, rotational and translational energies between the products of the reaction by which H + F2 yields HF + F. Diagrams are plotted and numerical values are obtained for the energy distribution rate constants.

  5. Effects of Distributed Energy Resources on Conservation Voltage Reduction (CVR)

    SciTech Connect

    Singh, Ruchi; Tuffner, Francis K.; Fuller, Jason C.; Schneider, Kevin P.

    2011-10-10

    Conservation Voltage Reduction (CVR) is one of the cheapest technologies which can be intelligently leveraged to provide considerable energy savings. The addition of renewables in the form of distributed resources can affect the entire power system, but more importantly, affects the traditional substation control schemes at the distribution level. This paper looks at the effect on energy consumption, peak load reduction, and voltage profile changes due to the addition of distributed generation in a distribution feeder using combinations of volt var control. An IEEE 13-node system is used to simulate the various cases. Energy savings and peak load reduction for different simulation scenarios are compared.

  6. Distribution of energy in corn plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenced by recent events in fossil fuel prices, both economic and environmental, as well as increased concerns about both climate change and energy independence, there is a growing interest in the development of renewable energy biomass feedstocks. These feedstocks include perennial grasses, timb...

  7. The absolute path command

    2012-05-11

    The ap command traveres all symlinks in a given file, directory, or executable name to identify the final absolute path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it canmore » provide the absolute path to a relative directory from the current working directory.« less

  8. The absolute path command

    SciTech Connect

    Moody, A.

    2012-05-11

    The ap command traveres all symlinks in a given file, directory, or executable name to identify the final absolute path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it can provide the absolute path to a relative directory from the current working directory.

  9. Energy distribution in parallel plate plasma accelerators

    NASA Technical Reports Server (NTRS)

    Dicapua, M. S.

    1973-01-01

    A parallel plate accelerator operated in the quasi-steady regime of argon mass flow discharges permits, on account of its geometry, the appraisal of the initial ratio of energy disposition into the kinetic and thermal modes of the plasma while retaining the essential features of coaxial high power self-field MPD accelerators. The energy disposition ratio, calculated as the ratio of kinetic energy to enthalpy in the exhaust flow, shows reasonable agreement with the ratio of the induced emf in the accelerator to resistive voltage drop. Both these ratios indicate that the discharge imparts more energy to the flow by resistive heating than by direct body force acceleration. This is turn suggests that other acceleration mechanisms must be responsible for the high performance of conventional MPD arcs.

  10. Distributed energy storage: Time-dependent tree flow design

    NASA Astrophysics Data System (ADS)

    Bejan, A.; Ziaei, S.; Lorente, S.

    2016-05-01

    This article proposes "distributed energy storage" as a basic design problem of distributing energy storage material on an area. The energy flows by fluid flow from a concentrated source to points (users) distributed equidistantly on the area. The flow is time-dependent. Several scenarios are analyzed: sensible-heat storage, latent-heat storage, exergy storage vs energy storage, and the distribution of a finite supply of heat transfer surface between the source fluid and the distributed storage material. The chief conclusion is that the finite amount of storage material should be distributed proportionally with the distribution of the flow rate of heating agent arriving on the area. The total time needed by the source stream to "invade" the area is cumulative (the sum of the storage times required at each storage site) and depends on the energy distribution paths and the sequence in which the users are served by the source stream. Directions for future designs of distributed storage and retrieval are outlined in the concluding section.

  11. Energy Distributions in Small Populations: Pascal versus Boltzmann

    ERIC Educational Resources Information Center

    Kugel, Roger W.; Weiner, Paul A.

    2010-01-01

    The theoretical distributions of a limited amount of energy among small numbers of particles with discrete, evenly-spaced quantum levels are examined systematically. The average populations of energy states reveal the pattern of Pascal's triangle. An exact formula for the probability that a particle will be in any given energy state is derived.…

  12. Kappa distribution in the presence of a potential energy

    NASA Astrophysics Data System (ADS)

    Livadiotis, George

    2015-02-01

    The present paper develops the theory and formulations of the kappa distributions that describe particle systems characterized by a nonzero potential energy. As yet, kappa distributions were used for the statistical description of the velocity or kinetic energy of particles but not of the potential energy. With the results provided here, it is straightforward to use the developed kappa distributions to describe any particle population of space plasmas subject to a nonnegligible potential energy. Starting from the kappa distribution of the Hamiltonian function, we develop the distributions that describe either the complete phase space or the marginal spaces of positions and velocities. The study shows, among others: (a) The kappa distributions of velocities that describe space plasmas can be vastly different from the standard formulation of the kappa distribution, because of the presence of a potential energy; the correct formulation should be given by the marginal kappa distribution of velocities by integrating the distribution of the Hamiltonian over the potential energy. (b) The long-standing problem of the divergence of the Boltzmannian exponential distribution for bounded radial potentials is solved using kappa distributions of negative kappa index. (c) Anisotropic distributions of velocities can exist in the presence of a velocity-dependent potential. (d) A variety of applications, including derivations/verifications of the following: (i) the Jeans', the most frequent, and the maximum radii in spherical/linear gravitational potentials; (ii) the Virial theorem for power law potentials; (iii) the generalized barometric formula, (iv) the plasma density profiles in Saturnian magnetosphere, and (v) the average electron magnetic moment in Earth's magnetotail.

  13. Stability of the Free and Bound Microstates of a Mobile Loop of α-Amylase Obtained from the Absolute Entropy and Free Energy.

    PubMed

    Cheluvaraja, Srinath; Meirovitch, Hagai

    2008-01-01

    The hypothetical scanning molecular dynamics (HSMD) method is a relatively new technique for calculating the absolute entropy, S, and free energy, F, from a given sample generated by any simulation procedure. Thus, each sample conformation, i, is reconstructed by calculating transition probabilities that their product leads to the probability of i, hence to the entropy. HSMD is an exact method where all interactions are considered, and the only approximation is due to insufficient sampling. In previous studies HSMD (and HS Monte Carlo - HSMC) has been applied very successfully to liquid argon, TIP3P water, self-avoiding walks, and peptides in a α-helix, extended, and hairpin microstates. In this paper HSMD is developed further as applied to the flexible 7-residue surface loop, 304-310 (Gly-His-Gly-Ala-Gly-Gly-Ser) of the enzyme porcine pancreatic α-amylase. We are mainly interested in entropy and free energy differences ΔS = Sfree - Sbound (and ΔF=Ffree-Fbound) between the free and bound microstates of the loop, which are obtained from two separate MD samples of these microstates without the need to carry out thermodynamic integration. As for peptides, we find that relatively large systematic errors in Sfree and Sbound (and Ffree and Fbound) are cancelled in ΔS (ΔF) which is thus obtained efficiently with high accuracy, i.e., with a statistical error of 0.1-0.2 kcal/mol (T=300 K) using the AMBER force field and AMBER with the implicit solvation GB/SA. We provide theoretical arguments in support of this cancellation, discuss in detail the problems involved in the computational definition of a microstate in conformational space, suggest potential ways for enhancing efficiency further, and describe the next development where explicit water will replace implicit solvation. PMID:26619992

  14. Energy optimization of water distribution system

    SciTech Connect

    Not Available

    1993-02-01

    In order to analyze pump operating scenarios for the system with the computer model, information on existing pumping equipment and the distribution system was collected. The information includes the following: component description and design criteria for line booster stations, booster stations with reservoirs, and high lift pumps at the water treatment plants; daily operations data for 1988; annual reports from fiscal year 1987/1988 to fiscal year 1991/1992; and a 1985 calibrated KYPIPE computer model of DWSD`s water distribution system which included input data for the maximum hour and average day demands on the system for that year. This information has been used to produce the inventory database of the system and will be used to develop the computer program to analyze the system.

  15. Subtleties in obtaining the electrostatic energy of continuous distributions

    NASA Astrophysics Data System (ADS)

    Bezerra, M.; Souza, Reinaldo de Melo e.; Kort-Kamp, W. J. M.; Farina, C.

    2014-11-01

    The mathematical steps that generalize the expression for the electrostatic energy of a set of point charges to the corresponding expression for a continuous charge distribution involve a few subtleties that are not usually discussed in standard introductory or advanced electromagnetic textbooks. In this paper, we point out such subtleties and discuss how to deal with them in cases of volume and surface charge distributions. We also show explicitly that it is not possible to define electrostatic energy for a linear charge distribution, since this energy would be divergent. Finally, we use dimensional analysis to recover our results in a simpler and more elegant form.

  16. Distributed Energy Resources for Carbon Emissions Mitigation

    SciTech Connect

    Firestone, Ryan; Marnay, Chris

    2007-05-01

    The era of publicly mandated GHG emissions restrictions inthe United States has begun with recent legislation in California andseven northeastern states. Commercial and industrial buildings canimprove the carbon-efficiency of end-use energy consumption by installingtechnologies such as on-site cogeneration of electricity and useful heatin combined heat and power systems, thermally-activated cooling, solarelectric and thermal equipment, and energy storage -- collectively termeddistributed energy resources (DER). This research examines a collectionof buildings in California, the Northeast, and the southern United Statesto demonstrate the effects of regional characteristics such as the carbonintensity of central electricity grid, the climate-driven demand forspace heating and cooling, and the availability of solar insolation. Theresults illustrate that the magnitude of a realistic carbon tax ($100/tC)is too small to incent significant carbon-reducing effects oneconomically optimal DER adoption. In large part, this is because costreduction and carbon reduction objectives are roughly aligned, even inthe absence of a carbon tax.

  17. Ion Flux and Ion Energy Distributions in an Inductively Coupled GEC Rf Refererence Cell in Chlorine

    NASA Astrophysics Data System (ADS)

    Radovanov, Svetlana; Forrister, Ray; Anderson, Harold

    1996-10-01

    Ion flux and energy distribution measurements in pure chlorine were performed in an inductively coupled Gaseous Electronics Reference Cell 13.56 MHz radiofrequency discharge . Measurements were made using miniaturized gridded energy analyzer. This detector was developed at the University of New Mexico, based on earlier design of the small size energy analyzers at MIT. The detector was mounted on a 12 inch water cooled carrier to suppress probe heating. The probe could be radially moved in the discharge cell to monitor the radial uniformity of the plasma. In addition, the detector was protected with a ceramic coating to supress for the electron saturation current of unshielded probe areas. The measurements were done in the "bright " mode dominated by inductive coupling at different pressures and powers. The radial variation of the ion flux in pure chlorine and argon show similar strongly nonuniform profile. As expected, absolute ion flux values in chlorine are substantially decreased compared to pure argon discharge. The spatial nonuniformity across the 16 cm diameter surface of the grounded electrode is in agreement with the Langmuir probe measurements done by Miller and MIT measurements in pure argon. The ion energy distribution functions (IEDs) measured exhibit a complex structure indicative of both light Cl^+ and heavier Cl_2^+ ions. The IEDs in chlorine are much broder than those measured in pure argon plasma. The radial profile of IEDs found in the GEC/ICP chlorine discharge indicate large changes are occuring in the nature of power coupling to the discharge moving center to edge.

  18. Distributed Energy Communications & Controls, Lab Activities - Synopsis

    SciTech Connect

    Rizy, D Tom

    2010-01-01

    Electric power distribution systems are experiencing outages due to a phenomenon known as fault induced delayed voltage recovery (FIDVR) due to air conditioning (A/C) compressor motor stall. Local voltage collapse from FIDVR is occurring in part because modern air-conditioner and heat pump compressor motors are much more susceptible to stalling during a voltage sag or dip than older motors. These motors can stall in less than three cycles (0.05 s) when a fault, for example, on the sub-transmission system, causes voltage on the distribution system to sag to 70% or less of nominal. We completed a new test system for A/C compressor motor stall testing at the DECC Lab. The A/C Stall test system is being used to characterize when and how compressor motors stall under low voltage and high compressor pressure conditions. However, instead of using air conditioners, we are using high efficiency heat pumps. We have gathered A/C stall characterization data for both sustained and momentary voltage sags of the test heat pump. At low enough voltage, the heat pump stalls (compressor motor stops and draws 5-6 times normal current in trying to restart) due to low inertia and low torque of the motor. For the momentary sag, we are using a fast acting contactor/switch to quickly switch from nominal to the sagged voltage in cycles.

  19. Deriving star formation histories from photometry using energy balance spectral energy distribution modelling

    NASA Astrophysics Data System (ADS)

    Smith, Daniel J. B.; Hayward, Christopher C.

    2015-10-01

    Panchromatic spectral energy distribution fitting is a critical tool for determining the physical properties of distant galaxies, such as their stellar mass and star formation rate. One widely used method is the publicly available MAGPHYS code. We build on our previous analysis by presenting some modifications which enable MAGPHYS to automatically estimate galaxy star formation histories (SFHs), including uncertainties, based on ultraviolet to far-infrared photometry. We use state-of-the art synthetic photometry derived by performing three-dimensional dust radiative transfer on hydrodynamic simulations of isolated disc and merging galaxies to test how well the modified MAGPHYS is able to recover SFHs under idealized conditions, where the true SFH is known. We find that while the SFH of the model with the best fit to the synthetic photometry is a poor representation of the true SFH (showing large variations with the line of sight to the galaxy and spurious bursts of star formation), median-likelihood SFHs generated by marginalizing over the default MAGPHYS libraries produce robust estimates of the smoothly varying isolated disc simulation SFHs. This preference for the median-likelihood SFH is quantitatively underlined by our estimates of χ ^2_SFH (analogous to the χ2 goodness-of-fit estimator) and Δ M / M (the integrated absolute mass discrepancy between the model and true SFH) that strongly prefer the median-likelihood SFHs over those that best fit the UV-to-far-IR photometry. In contrast, we are unable to derive a good estimate of the SFH for the merger simulations (either best fit or median likelihood) despite being able to obtain a reasonable fit to the simulated photometry, likely because the analytic SFHs with bursts superposed in the standard MAGPHYS library are insufficiently general/realistic.

  20. Electric Transport Traction Power Supply System With Distributed Energy Sources

    NASA Astrophysics Data System (ADS)

    Abramov, E. Y.; Schurov, N. I.; Rozhkova, M. V.

    2016-04-01

    The paper states the problem of traction substation (TSS) leveling of daily-load curve for urban electric transport. The circuit of traction power supply system (TPSS) with distributed autonomous energy source (AES) based on photovoltaic (PV) and energy storage (ES) units is submitted here. The distribution algorithm of power flow for the daily traction load curve leveling is also introduced in this paper. In addition, it illustrates the implemented experiment model of power supply system.

  1. Development of reference states for use in absolute free energy calculations of atomic clusters with application to 55-atom Lennard-Jones clusters in the solid and liquid states

    NASA Astrophysics Data System (ADS)

    Amon, L. M.; Reinhardt, W. P.

    2000-09-01

    In this paper four reference states allowing computation of the absolute internal free energies of solid and liquid clusters are introduced and implemented. Three of these are introduced for the first time. Two of these references are useful for highly fluctional liquidlike clusters while the other two are appropriate for more rigid solidlike clusters. These reference states are combined with a finite time variational method to obtain upper and lower bounds to the absolute free energies of clusters of Lennard-Jones (LJ) atoms, LJ4 and LJ55, allowing the efficiency of each of the four reference states to be elucidated. The optimal references are then applied to obtain upper and lower bounds to the internal free energies (the absolute free energy in the cluster center of mass frame) of LJ55 over a series of fixed temperatures including the solid-liquid coexistence regime. The reversible scaling method, recently introduced by de Koning, Antonelli, and Yip, is then used to extend the results over a continuous range of temperatures. Estimation of the rotational free energy allows comparisons to free energies of LJ55 in the nonrotating center of mass frame as estimated by Doye and Wales.

  2. Energy distribution among reaction products. V.

    NASA Technical Reports Server (NTRS)

    Anlauf, K. G.; Horne, D. S.; Macdonald, R. G.; Polanyi, J. C.; Woodall, K. B.

    1972-01-01

    Discussion of three reactions, one point of theoretical interest being the predicted correlation between barrier height and barrier location. The H + Br 2 reaction having a lower activation barrier than H + Cl 2, should have an earlier barrier, and hence a greater percentage attractive energy release and higher efficiency of vibrational excitation. Information is developed concerning the effect of isotopic substitution in the pair of reactions H + Cl 2 and D + Cl 2. The 'arrested relaxation' method was used. Essentially, the method involves reacting two diffuse reagent beams in a reaction vessel with background pressure less than 0.001 torr, and with walls cooled by liquid nitrogen or liquid helium.

  3. Ultraviolet photometry from the Orbiting Astronomical Observatory. XL - The energy distributions of spiral and irregular galaxies

    NASA Technical Reports Server (NTRS)

    Code, A. D.; Welch, G. A.

    1982-01-01

    Measurements of the total light of 40 spiral and irregular galaxies are presented. The photometry covers the wavelength range 1550-4250 A and is calibrated on an absolute basis. On the average later-type galaxies are not only bluer at short wavelengths than ellipticals but significantly bluer than visual colors would imply. This reflects a recent history of more vigorous formation of massive stars. The shape of the upper part of the initial mass function apparently varies more among early-type galaxies, producing a wide scatter in their energy distributions. In at least some galaxies interstellar dust appears to have little influence upon the emerging radiation. The local volume luminosity spectrum due to galaxies turns up steeply at short wavelengths, and is shaped largely by contributions from late-type galaxies. The observed ultraviolet background cannot be produced by normal galaxies, although the large corrections implied by theoretical evolutionary models may account for the measurements.

  4. Development of a high-energy distributed energy source electromagnetic railgun with improved energy conversion efficiency

    SciTech Connect

    Tower, M.M.; Haight, C.H.

    1984-03-01

    Vought Corporation in cooperation with the Center for Electromechanics at the University of Texas (CEM-UT) has developed under sponsorship by the Defense Advanced Research Projects Agency (DARPA) and the Army Armament, Munitions, and Chemical Command (AMCCOM) a high-energy distributed energy source (DES) electromagnetic (EM) railgun accelerator. This paper discusses the development and current status of the DES railgun which has the design capability to launch projectile masses up to 60 grams to the 3-4 km/sec velocity regime with energy conversion efficiencies above 35 percent. These goals are being accomplished through utilization of scaled-energy CEM-UT railgun experiments for sequenced timing/staging and a full energy (575 kJ) design at Vought for high efficiency capability. The operational Vought single-pulse railgun forms the baseline for the full energy testing.

  5. Optimal Operation of Energy Storage in Power Transmission and Distribution

    NASA Astrophysics Data System (ADS)

    Akhavan Hejazi, Seyed Hossein

    In this thesis, we investigate optimal operation of energy storage units in power transmission and distribution grids. At transmission level, we investigate the problem where an investor-owned independently-operated energy storage system seeks to offer energy and ancillary services in the day-ahead and real-time markets. We specifically consider the case where a significant portion of the power generated in the grid is from renewable energy resources and there exists significant uncertainty in system operation. In this regard, we formulate a stochastic programming framework to choose optimal energy and reserve bids for the storage units that takes into account the fluctuating nature of the market prices due to the randomness in the renewable power generation availability. At distribution level, we develop a comprehensive data set to model various stochastic factors on power distribution networks, with focus on networks that have high penetration of electric vehicle charging load and distributed renewable generation. Furthermore, we develop a data-driven stochastic model for energy storage operation at distribution level, where the distribution of nodal voltage and line power flow are modelled as stochastic functions of the energy storage unit's charge and discharge schedules. In particular, we develop new closed-form stochastic models for such key operational parameters in the system. Our approach is analytical and allows formulating tractable optimization problems. Yet, it does not involve any restricting assumption on the distribution of random parameters, hence, it results in accurate modeling of uncertainties. By considering the specific characteristics of random variables, such as their statistical dependencies and often irregularly-shaped probability distributions, we propose a non-parametric chance-constrained optimization approach to operate and plan energy storage units in power distribution girds. In the proposed stochastic optimization, we consider

  6. General theory for apparent energy distribution of sea waves

    NASA Astrophysics Data System (ADS)

    Wu, Ke-Jian; Sun, Fu

    1997-12-01

    This paper presents a general theory for the apparent energy distribution of sea waves. Using the joint distribution of wave periods and heights proposed earlier by the second author, the authors define the generalized apparent energy distribution and derive the analytical form of the so called generalized outer frequency spectrum or nth-order frequency spectrum. Some possible relationships between it and the Fourier frequency spectrum are discussed. It is shown that the widely used Bretschneider spectrum can be easily obtained from the above definition and that generalized outer frequency spectrum has equilibrium range with exponent -( n+3) whose upper limit is -3.

  7. Distributed Sensor Coordination for Advanced Energy Systems

    SciTech Connect

    Tumer, Kagan

    2013-07-31

    The ability to collect key system level information is critical to the safe, efficient and reli- able operation of advanced energy systems. With recent advances in sensor development, it is now possible to push some level of decision making directly to computationally sophisticated sensors, rather than wait for data to arrive to a massive centralized location before a decision is made. This type of approach relies on networked sensors (called “agents” from here on) to actively collect and process data, and provide key control deci- sions to significantly improve both the quality/relevance of the collected data and the as- sociating decision making. The technological bottlenecks for such sensor networks stem from a lack of mathematics and algorithms to manage the systems, rather than difficulties associated with building and deploying them. Indeed, traditional sensor coordination strategies do not provide adequate solutions for this problem. Passive data collection methods (e.g., large sensor webs) can scale to large systems, but are generally not suited to highly dynamic environments, such as ad- vanced energy systems, where crucial decisions may need to be reached quickly and lo- cally. Approaches based on local decisions on the other hand cannot guarantee that each agent performing its task (maximize an agent objective) will lead to good network wide solution (maximize a network objective) without invoking cumbersome coordination rou- tines. There is currently a lack of algorithms that will enable self-organization and blend the efficiency of local decision making with the system level guarantees of global decision making, particularly when the systems operate in dynamic and stochastic environments. In this work we addressed this critical gap and provided a comprehensive solution to the problem of sensor coordination to ensure the safe, reliable, and robust operation of advanced energy systems. The differentiating aspect of the proposed work is in shift- ing

  8. Recent Ion Energy Distribution Observations on MST RFP Plasmas

    NASA Astrophysics Data System (ADS)

    Clark, Jerry; Titus, J. B.; Mezonlin, E. D.; Johnson, J. A., III; Almagri, A. F.; Andeson, J. A.

    2015-11-01

    Ion energy distribution and temperature measurements have been made on the Madison Symmetric Torus (MST) using the Florida A&M University compact neutral particle analyzer (CNPA). The CNPA is a low energy (0.34-5.2 keV), high energy resolution (25 channels) neutral particle analyzer, with a radial view on MST. Recently, a retarding potential system was built to allow CNPA measurements to ensemble a complete ion energy distribution with high-energy resolution, providing insight into the dynamics of the bulk and fast ion populations. Recent work has also been done to improve the analysis techniques used to infer the ion temperature measurements, allowing us to understand temperature dynamics better during global magnetic reconnection events. Work supported in part by grants to FAMU and to UW from NSF and from Fusion Energy Sciences at DOE.

  9. Parallel Harmony Search Based Distributed Energy Resource Optimization

    SciTech Connect

    Ceylan, Oguzhan; Liu, Guodong; Tomsovic, Kevin

    2015-01-01

    This paper presents a harmony search based parallel optimization algorithm to minimize voltage deviations in three phase unbalanced electrical distribution systems and to maximize active power outputs of distributed energy resources (DR). The main contribution is to reduce the adverse impacts on voltage profile during a day as photovoltaics (PVs) output or electrical vehicles (EVs) charging changes throughout a day. The IEEE 123- bus distribution test system is modified by adding DRs and EVs under different load profiles. The simulation results show that by using parallel computing techniques, heuristic methods may be used as an alternative optimization tool in electrical power distribution systems operation.

  10. Distributed sensor coordination for advanced energy systems

    SciTech Connect

    Tumer, Kagan

    2015-03-12

    Motivation: The ability to collect key system level information is critical to the safe, efficient and reliable operation of advanced power systems. Recent advances in sensor technology have enabled some level of decision making directly at the sensor level. However, coordinating large numbers of sensors, particularly heterogeneous sensors, to achieve system level objectives such as predicting plant efficiency, reducing downtime or predicting outages requires sophisticated coordination algorithms. Indeed, a critical issue in such systems is how to ensure the interaction of a large number of heterogenous system components do not interfere with one another and lead to undesirable behavior. Objectives and Contributions: The long-term objective of this work is to provide sensor deployment, coordination and networking algorithms for large numbers of sensors to ensure the safe, reliable, and robust operation of advanced energy systems. Our two specific objectives are to: 1. Derive sensor performance metrics for heterogeneous sensor networks. 2. Demonstrate effectiveness, scalability and reconfigurability of heterogeneous sensor network in advanced power systems. The key technical contribution of this work is to push the coordination step to the design of the objective functions of the sensors, allowing networks of heterogeneous sensors to be controlled. By ensuring that the control and coordination is not specific to particular sensor hardware, this approach enables the design and operation of large heterogeneous sensor networks. In addition to the coordination coordination mechanism, this approach allows the system to be reconfigured in response to changing needs (e.g., sudden external events requiring new responses) or changing sensor network characteristics (e.g., sudden changes to plant condition). Impact: The impact of this work extends to a large class of problems relevant to the National Energy Technology Laboratory including sensor placement, heterogeneous sensor

  11. Cosmology with negative absolute temperatures

    NASA Astrophysics Data System (ADS)

    Vieira, J. P. P.; Byrnes, Christian T.; Lewis, Antony

    2016-08-01

    Negative absolute temperatures (NAT) are an exotic thermodynamical consequence of quantum physics which has been known since the 1950's (having been achieved in the lab on a number of occasions). Recently, the work of Braun et al. [1] has rekindled interest in negative temperatures and hinted at a possibility of using NAT systems in the lab as dark energy analogues. This paper goes one step further, looking into the cosmological consequences of the existence of a NAT component in the Universe. NAT-dominated expanding Universes experience a borderline phantom expansion (w < ‑1) with no Big Rip, and their contracting counterparts are forced to bounce after the energy density becomes sufficiently large. Both scenarios might be used to solve horizon and flatness problems analogously to standard inflation and bouncing cosmologies. We discuss the difficulties in obtaining and ending a NAT-dominated epoch, and possible ways of obtaining density perturbations with an acceptable spectrum.

  12. Electronic Absolute Cartesian Autocollimator

    NASA Technical Reports Server (NTRS)

    Leviton, Douglas B.

    2006-01-01

    An electronic absolute Cartesian autocollimator performs the same basic optical function as does a conventional all-optical or a conventional electronic autocollimator but differs in the nature of its optical target and the manner in which the position of the image of the target is measured. The term absolute in the name of this apparatus reflects the nature of the position measurement, which, unlike in a conventional electronic autocollimator, is based absolutely on the position of the image rather than on an assumed proportionality between the position and the levels of processed analog electronic signals. The term Cartesian in the name of this apparatus reflects the nature of its optical target. Figure 1 depicts the electronic functional blocks of an electronic absolute Cartesian autocollimator along with its basic optical layout, which is the same as that of a conventional autocollimator. Referring first to the optical layout and functions only, this or any autocollimator is used to measure the compound angular deviation of a flat datum mirror with respect to the optical axis of the autocollimator itself. The optical components include an illuminated target, a beam splitter, an objective or collimating lens, and a viewer or detector (described in more detail below) at a viewing plane. The target and the viewing planes are focal planes of the lens. Target light reflected by the datum mirror is imaged on the viewing plane at unit magnification by the collimating lens. If the normal to the datum mirror is parallel to the optical axis of the autocollimator, then the target image is centered on the viewing plane. Any angular deviation of the normal from the optical axis manifests itself as a lateral displacement of the target image from the center. The magnitude of the displacement is proportional to the focal length and to the magnitude (assumed to be small) of the angular deviation. The direction of the displacement is perpendicular to the axis about which the

  13. Calculation of energy deposition distributions for simple geometries

    NASA Technical Reports Server (NTRS)

    Watts, J. W., Jr.

    1973-01-01

    When high-energy charged particles pass through a thin detector, the ionization energy loss in that detector is subject to fluctuations or straggling which must be considered in interpreting the data. Under many conditions, which depend upon the charge and energy of the incident particle and the detector geometry, the ionization energy lost by the particle is significantly different from the energy deposited in the detector. This problem divides naturally into a calculation of the energy loss that results in excitation and low-energy secondary electrons which do not travel far from their production points, and a calculation of energy loss that results in high-energy secondary electrons which can escape from the detector. The first calculation is performed using a modification of the Vavilov energy loss distribution. A cutoff energy is introduced above which all electrons are ignored and energy transferred to low energy particles is assumed to be equivalent to the energy deposited by them. For the second calculation, the trajectory of the primary particle is considered as a source of secondary high-energy electrons. The electrons from this source are transported using Monte Carlo techniques and multiple scattering theory, and the energy deposited by them in the detector is calculated. The results of the two calculations are then combined to predict the energy deposition distribution. The results of these calculations are used to predict the charge resolution of parallel-plate pulse ionization chambers that are being designed to measure the charge spectrum of heavy nuclei in the galactic cosmic-ray flux.

  14. Far-ultraviolet energy distributions of the metal-poor A stars HD 109995 and HD 161817

    NASA Technical Reports Server (NTRS)

    Boehm-Vitense, E.

    1981-01-01

    Low-resolution IUE spectra at wavelengths between 1300 and 3400 A of the metal-poor stars HD 109995 (A1p) and HD 161817 (A4p) have been compared with model-atmosphere energy distributions computed by Kurucz (1979). Good overall agreement is found. Effective temperatures, metal abundances, and angular diameters could be determined. Assuming an absolute visual magnitude of 0.7, the previously determined gravity log = 3 yields masses of 0.5 solar masses for both stars. It is found that the theoretical UBV colors calculated earlier agree reaonably well with the ones observed for these stars.

  15. Laser energy distribution on detector under the different incident angle

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Wang, G.; Chen, Q.; Hao, Y.; Zhang, W.; Li, H.; Ren, G.; Zhu, R.

    2015-11-01

    Laser active suppressing jamming is one of the most important technologies in the domain of electro-optical countermeasures. The propagation direction of laser is not always in the same line with the principal axis of electro-optical imaging system, so it is necessary to investigate laser energy distribution on detector under the different incident angle. This paper toke optical system with wide field of view for example. We firstly analyzed the system's structure based on the inverting prism and evaluated image quality. Laser energy distribution caused by diffraction effect of optical system was secondly simulated based on Kirchhoff 's diffraction theory. Thirdly, we built the system's analysis model of stray light, traced a large number of light propagation, and obtained laser energy distribution on detector caused by scattering effect. At last, combine the above two kinds of energy distribution into total laser energy distribution on detector. According to the detector's saturated threshold, we can count up the saturated number and evaluate laser disturbing effect. The research results can provide theoretical reference and technical support for evaluating laser disturbing effect of electro-optical imaging system.

  16. Precise Measurement of the Absolute Fluorescence Yield

    NASA Astrophysics Data System (ADS)

    Ave, M.; Bohacova, M.; Daumiller, K.; Di Carlo, P.; di Giulio, C.; San Luis, P. Facal; Gonzales, D.; Hojvat, C.; Hörandel, J. R.; Hrabovsky, M.; Iarlori, M.; Keilhauer, B.; Klages, H.; Kleifges, M.; Kuehn, F.; Monasor, M.; Nozka, L.; Palatka, M.; Petrera, S.; Privitera, P.; Ridky, J.; Rizi, V.; D'Orfeuil, B. Rouille; Salamida, F.; Schovanek, P.; Smida, R.; Spinka, H.; Ulrich, A.; Verzi, V.; Williams, C.

    2011-09-01

    We present preliminary results of the absolute yield of fluorescence emission in atmospheric gases. Measurements were performed at the Fermilab Test Beam Facility with a variety of beam particles and gases. Absolute calibration of the fluorescence yield to 5% level was achieved by comparison with two known light sources--the Cherenkov light emitted by the beam particles, and a calibrated nitrogen laser. The uncertainty of the energy scale of current Ultra-High Energy Cosmic Rays experiments will be significantly improved by the AIRFLY measurement.

  17. ABSOLUTE POLARIMETRY AT RHIC.

    SciTech Connect

    OKADA; BRAVAR, A.; BUNCE, G.; GILL, R.; HUANG, H.; MAKDISI, Y.; NASS, A.; WOOD, J.; ZELENSKI, Z.; ET AL.

    2007-09-10

    Precise and absolute beam polarization measurements are critical for the RHIC spin physics program. Because all experimental spin-dependent results are normalized by beam polarization, the normalization uncertainty contributes directly to final physics uncertainties. We aimed to perform the beam polarization measurement to an accuracy Of {Delta}P{sub beam}/P{sub beam} < 5%. The absolute polarimeter consists of Polarized Atomic Hydrogen Gas Jet Target and left-right pairs of silicon strip detectors and was installed in the RHIC-ring in 2004. This system features proton-proton elastic scattering in the Coulomb nuclear interference (CNI) region. Precise measurements of the analyzing power A{sub N} of this process has allowed us to achieve {Delta}P{sub beam}/P{sub beam} = 4.2% in 2005 for the first long spin-physics run. In this report, we describe the entire set up and performance of the system. The procedure of beam polarization measurement and analysis results from 2004-2005 are described. Physics topics of AN in the CNI region (four-momentum transfer squared 0.001 < -t < 0.032 (GeV/c){sup 2}) are also discussed. We point out the current issues and expected optimum accuracy in 2006 and the future.

  18. Accurate calculation of the absolute free energy of binding for drug molecules† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c5sc02678d Click here for additional data file.

    PubMed Central

    Aldeghi, Matteo; Heifetz, Alexander; Bodkin, Michael J.; Knapp, Stefan

    2016-01-01

    Accurate prediction of binding affinities has been a central goal of computational chemistry for decades, yet remains elusive. Despite good progress, the required accuracy for use in a drug-discovery context has not been consistently achieved for drug-like molecules. Here, we perform absolute free energy calculations based on a thermodynamic cycle for a set of diverse inhibitors binding to bromodomain-containing protein 4 (BRD4) and demonstrate that a mean absolute error of 0.6 kcal mol–1 can be achieved. We also show a similar level of accuracy (1.0 kcal mol–1) can be achieved in pseudo prospective approach. Bromodomains are epigenetic mark readers that recognize acetylation motifs and regulate gene transcription, and are currently being investigated as therapeutic targets for cancer and inflammation. The unprecedented accuracy offers the exciting prospect that the binding free energy of drug-like compounds can be predicted for pharmacologically relevant targets. PMID:26798447

  19. Exploring Distributed Energy Alternatives to Electrical Distribution Grid Expansion in Souhern California Edison Service Territory

    SciTech Connect

    Stovall, Therese K; Kingston, Tim

    2005-12-01

    Distributed energy (DE) technologies have received much attention for the energy savings and electric power reliability assurances that may be achieved by their widespread adoption. Fueling the attention have been the desires to globally reduce greenhouse gas emissions and concern about easing power transmission and distribution system capacity limitations and congestion. However, these benefits may come at a cost to the electric utility companies in terms of lost revenue and concerns with interconnection on the distribution system. This study assesses the costs and benefits of DE to both consumers and distribution utilities and expands upon a precursory study done with Detroit Edison (DTE)1, by evaluating the combined impact of DE, energy-efficiency, photovoltaics (a use of solar energy), and demand response that will shape the grid of the future. This study was funded by the U.S. Department of Energy (DOE), Gas Research Institute (GRI), American Electric Power (AEP), and Gas Technology Institute's (GTI) Distributed Energy Collaborative Program (DECP). It focuses on two real Southern California Edison (SCE) circuits, a 13 MW suburban circuit fictitiously named Justice on the Lincoln substation, and an 8 MW rural circuit fictitiously named Prosper on the Washington Substation. The primary objectives of the study were threefold: (1) Evaluate the potential for using advanced energy technologies, including DE, energy-efficiency (EE), demand response, electricity storage, and photovoltaics (PV), to reshape electric load curves by reducing peak demand, for real circuits. (2) Investigate the potential impact on guiding technology deployment and managing operation in a way that benefits both utilities and their customers by: (a) Improving grid load factor for utilities; (b) Reducing energy costs for customers; and (c) Optimizing electric demand growth. (3) Demonstrate benefits by reporting on a recently installed advanced energy system at a utility customer site. This

  20. High-energy tail distributions and resonant wave particle interaction

    NASA Technical Reports Server (NTRS)

    Leubner, M. P.

    1983-01-01

    High-energy tail distributions (k distributions) are used as an alternative to a bi-Lorentzian distribution to study the influence of energetic protons on the right- and left-hand cyclotron modes in a hot two-temperature plasma. Although the parameters are chosen to be in a range appropriate to solar wind or magnetospheric configurations, the results apply not only to specific space plasmas. The presence of energetic particles significantly alters the behavior of the electromagnetic ion cyclotron modes, leading to a wide range of unstable frequencies and increased growth rates. From the strongly enhanced growth rates it can be concluded that high-energy tail distributions should not show major temperature anisotropies, which is consistent with observations.

  1. Radial Distribution of Electron Spectra from High-Energy Ions

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Katz, Robert; Wilson, John W.

    1998-01-01

    The average track model describes the response of physical and biological systems using radial dose distribution as the key physical descriptor. We report on an extension of this model to describe the average distribution of electron spectra as a function of radial distance from an ion. We present calculations of these spectra for ions of identical linear energy transfer (LET), but dissimilar charge and velocity to evaluate the differences in electron spectra from these ions. To illustrate the usefulness of the radial electron spectra for describing effects that are not described by electron dose, we consider the evaluation of the indirect events in microdosimetric distributions for ions. We show that folding our average electron spectra model with experimentally determined frequency distributions for photons or electrons provides a good representation of radial event spectra from high-energy ions in 0.5-2 micrometer sites.

  2. Energy distributions of sputtered copper neutrals and ions

    NASA Technical Reports Server (NTRS)

    Lundquist, T. R.

    1978-01-01

    Direct quantitative analysis of surfaces by secondary ion mass spectrometry will depend on an understanding of the yield ratio of ions to neutrals. This ratio as a function of the energy of the sputtered particles has been obtained for a clean polycrystalline copper surface sputtered by 1000-3000 eV Ar(+). The energy distributions of both neutral and ionized copper were measured with a retarding potential analyzer using potential modulation differentiation and signal averaging. The maximum for both distributions is identical and occurs near 2.5 eV. The energy distributions of neutrals is more sharply peaked than that of the ions, presumably as a consequence of more efficient nutralization of slow escaping ions by the mobile electrons of copper. The ion-neutral ratio is compared with results from various ionization models.

  3. Intensity distribution analysis of cathodoluminescence using the energy loss distribution of electrons.

    PubMed

    Fukuta, Masahiro; Inami, Wataru; Ono, Atsushi; Kawata, Yoshimasa

    2016-01-01

    We present an intensity distribution analysis of cathodoluminescence (CL) excited with a focused electron beam in a luminescent thin film. The energy loss distribution is applied to the developed analysis method in order to determine the arrangement of the dipole locations along the path of the electron traveling in the film. Propagating light emitted from each dipole is analyzed with the finite-difference time-domain (FDTD) method. CL distribution near the film surface is evaluated as a nanometric light source. It is found that a light source with 30 nm widths is generated in the film by the focused electron beam. We also discuss the accuracy of the developed analysis method by comparison with experimental results. The analysis results are brought into good agreement with the experimental results by introducing the energy loss distribution. PMID:26550930

  4. Energy distribution of nanoflares in the quiet solar corona

    NASA Astrophysics Data System (ADS)

    Ulyanov, Artyom

    2012-07-01

    We present a detailed statistical analysis of flare-like events in low layer of solar corona detected with TESIS instrument onboard CORONAS-PHOTON satellite in 171 {Å} during high-cadence (5 sec) time-series. The estimated thermal energies of these small events amount to 10^{23} - 10^{26} erg. According to modern classification flare-like events with such energies are usually referred to as nanoflares. The big number of registered events (above 2000) allowed us to obtain precise distributions of geometric and physical parameters of nanoflares, the most intriguing being energy distribution. Following Aschwanden et al. (2000) and other authors we approximated the calculated energy distribution with a single power law slope: N(E)dE ˜ N^{-α}dE. The power law index was derived to be α = 2.4 ± 0.2, which is very close to the value reported by Krucker & Benz (1998): α ≈ 2.3 - 2.4. The total energy input from registered events constitute about 10^4 erg \\cdot cm^{-2} \\cdot s^{-1}, which is well beyond net losses in quiet corona (3 \\cdot 10^5 erg \\cdot cm^{-2} \\cdot s^{-1}). However, the value of α > 2 indicates that nanoflares with lower energies dominate over nanoflares with bigger energies and could contribute considerably to quiet corona heating.

  5. Velocity and energy distributions in microcanonical ensembles of hard spheres.

    PubMed

    Scalas, Enrico; Gabriel, Adrian T; Martin, Edgar; Germano, Guido

    2015-08-01

    In a microcanonical ensemble (constant NVE, hard reflecting walls) and in a molecular dynamics ensemble (constant NVEPG, periodic boundary conditions) with a number N of smooth elastic hard spheres in a d-dimensional volume V having a total energy E, a total momentum P, and an overall center of mass position G, the individual velocity components, velocity moduli, and energies have transformed beta distributions with different arguments and shape parameters depending on d, N, E, the boundary conditions, and possible symmetries in the initial conditions. This can be shown marginalizing the joint distribution of individual energies, which is a symmetric Dirichlet distribution. In the thermodynamic limit the beta distributions converge to gamma distributions with different arguments and shape or scale parameters, corresponding respectively to the Gaussian, i.e., Maxwell-Boltzmann, Maxwell, and Boltzmann or Boltzmann-Gibbs distribution. These analytical results agree with molecular dynamics and Monte Carlo simulations with different numbers of hard disks or spheres and hard reflecting walls or periodic boundary conditions. The agreement is perfect with our Monte Carlo algorithm, which acts only on velocities independently of positions with the collision versor sampled uniformly on a unit half sphere in d dimensions, while slight deviations appear with our molecular dynamics simulations for the smallest values of N. PMID:26382376

  6. Velocity and energy distributions in microcanonical ensembles of hard spheres

    NASA Astrophysics Data System (ADS)

    Scalas, Enrico; Gabriel, Adrian T.; Martin, Edgar; Germano, Guido

    2015-08-01

    In a microcanonical ensemble (constant N V E , hard reflecting walls) and in a molecular dynamics ensemble (constant N V E PG , periodic boundary conditions) with a number N of smooth elastic hard spheres in a d -dimensional volume V having a total energy E , a total momentum P , and an overall center of mass position G , the individual velocity components, velocity moduli, and energies have transformed beta distributions with different arguments and shape parameters depending on d , N , E , the boundary conditions, and possible symmetries in the initial conditions. This can be shown marginalizing the joint distribution of individual energies, which is a symmetric Dirichlet distribution. In the thermodynamic limit the beta distributions converge to gamma distributions with different arguments and shape or scale parameters, corresponding respectively to the Gaussian, i.e., Maxwell-Boltzmann, Maxwell, and Boltzmann or Boltzmann-Gibbs distribution. These analytical results agree with molecular dynamics and Monte Carlo simulations with different numbers of hard disks or spheres and hard reflecting walls or periodic boundary conditions. The agreement is perfect with our Monte Carlo algorithm, which acts only on velocities independently of positions with the collision versor sampled uniformly on a unit half sphere in d dimensions, while slight deviations appear with our molecular dynamics simulations for the smallest values of N .

  7. Energy Distributions and spectra of Orion B stars

    NASA Technical Reports Server (NTRS)

    Schild, R. E.; Chaffee, F.

    1972-01-01

    New MK spectral types and energy distributions are presented for B stars in Orion for which far ultraviolet flux excesses have recently been discovered. Significant differences between HD spectral energy distributions show the Orion late B stars to have smaller Balmer discontinuities than do field stars of the same spectral types. For the late B stars, these effects cause the 1500 A fluxes to be under-estimated by approximately 0.5 mag. No comparable systematic effects were found for the early B stars.

  8. Comparison of Measured Dark Current Distributions with Calculated Damage Energy Distributions in HgCdTe

    NASA Technical Reports Server (NTRS)

    Marshall, C. J.; Marshall, P. W.; Howe, C. L.; Reed, R. A.; Weller, R. A.; Mendenhall, M.; Waczynski, A.; Ladbury, R.; Jordan, T. M.

    2007-01-01

    This paper presents a combined Monte Carlo and analytic approach to the calculation of the pixel-to-pixel distribution of proton-induced damage in a HgCdTe sensor array and compares the results to measured dark current distributions after damage by 63 MeV protons. The moments of the Coulombic, nuclear elastic and nuclear inelastic damage distributions were extracted from Monte Carlo simulations and combined to form a damage distribution using the analytic techniques first described in [1]. The calculations show that the high energy recoils from the nuclear inelastic reactions (calculated using the Monte Carlo code MCNPX [2]) produce a pronounced skewing of the damage energy distribution. While the nuclear elastic component (also calculated using the MCNPX) contributes only a small fraction of the total nonionizing damage energy, its inclusion in the shape of the damage across the array is significant. The Coulombic contribution was calculated using MRED [3-5], a Geant4 [4,6] application. The comparison with the dark current distribution strongly suggests that mechanisms which are not linearly correlated with nonionizing damage produced according to collision kinematics are responsible for the observed dark current increases. This has important implications for the process of predicting the on-orbit dark current response of the HgCdTe sensor array.

  9. Implants as absolute anchorage.

    PubMed

    Rungcharassaeng, Kitichai; Kan, Joseph Y K; Caruso, Joseph M

    2005-11-01

    Anchorage control is essential for successful orthodontic treatment. Each tooth has its own anchorage potential as well as propensity to move when force is applied. When teeth are used as anchorage, the untoward movements of the anchoring units may result in the prolonged treatment time, and unpredictable or less-than-ideal outcome. To maximize tooth-related anchorage, techniques such as differential torque, placing roots into the cortex of the bone, the use of various intraoral devices and/or extraoral appliances have been implemented. Implants, as they are in direct contact with bone, do not possess a periodontal ligament. As a result, they do not move when orthodontic/orthopedic force is applied, and therefore can be used as "absolute anchorage." This article describes different types of implants that have been used as orthodontic anchorage. Their clinical applications and limitations are also discussed. PMID:16463910

  10. Absolute Equilibrium Entropy

    NASA Technical Reports Server (NTRS)

    Shebalin, John V.

    1997-01-01

    The entropy associated with absolute equilibrium ensemble theories of ideal, homogeneous, fluid and magneto-fluid turbulence is discussed and the three-dimensional fluid case is examined in detail. A sigma-function is defined, whose minimum value with respect to global parameters is the entropy. A comparison is made between the use of global functions sigma and phase functions H (associated with the development of various H-theorems of ideal turbulence). It is shown that the two approaches are complimentary though conceptually different: H-theorems show that an isolated system tends to equilibrium while sigma-functions allow the demonstration that entropy never decreases when two previously isolated systems are combined. This provides a more complete picture of entropy in the statistical mechanics of ideal fluids.

  11. A Petri Net model for distributed energy system

    SciTech Connect

    Konopko, Joanna

    2015-12-31

    Electrical networks need to evolve to become more intelligent, more flexible and less costly. The smart grid is the next generation power energy, uses two-way flows of electricity and information to create a distributed automated energy delivery network. Building a comprehensive smart grid is a challenge for system protection, optimization and energy efficient. Proper modeling and analysis is needed to build an extensive distributed energy system and intelligent electricity infrastructure. In this paper, the whole model of smart grid have been proposed using Generalized Stochastic Petri Nets (GSPN). The simulation of created model is also explored. The simulation of the model has allowed the analysis of how close the behavior of the model is to the usage of the real smart grid.

  12. A Petri Net model for distributed energy system

    NASA Astrophysics Data System (ADS)

    Konopko, Joanna

    2015-12-01

    Electrical networks need to evolve to become more intelligent, more flexible and less costly. The smart grid is the next generation power energy, uses two-way flows of electricity and information to create a distributed automated energy delivery network. Building a comprehensive smart grid is a challenge for system protection, optimization and energy efficient. Proper modeling and analysis is needed to build an extensive distributed energy system and intelligent electricity infrastructure. In this paper, the whole model of smart grid have been proposed using Generalized Stochastic Petri Nets (GSPN). The simulation of created model is also explored. The simulation of the model has allowed the analysis of how close the behavior of the model is to the usage of the real smart grid.

  13. The measurement and calculation of nanodosimetric energy distributions for electrons and photons

    NASA Astrophysics Data System (ADS)

    Evans, Thomas Michael

    1997-09-01

    Low dose and low dose rate fields constitute the majority of radiation exposure scenarios in radiation protection. Conversely, very little epidemiological or physical data are available at these levels. This situation exists because the parameters characterizing low dose and low dose rate environments are difficult to assess at cellular levels where the fundamental biological effects from radiation insults occur. The quantities required for a complete biological assessment are the distribution of energy deposition in biological targets and the cellular response to such insults. A new detector to measure physical energy depositions on nanometer scales was developed in this thesis. A computational tool was also developed to calculate clustered distributions of energy deposition from electrons and photons. A dosimeter has been developed which characterizes energy depositions from charged particles in nanometer dimensions. The dosimeter is a threshold-type detector based on the temperature response of the superheated liquid droplet detector (SLDD). SLDDs based on Freon-115 have been designed and tested. A data acquisition system that measures the acoustic signals from bubble nucleation events has been developed. An original electron track code, ESLOW3.1, has been developed. The code simulates electron tracks on an event-by-event basis down to an absolute minimum of 20 eV. The transport medium is water vapor. The cross sections have been compared with published data and theoretical models where available. Trial calculations of pertinent quantities are in good agreement with published results. A new operational quantity, the cluster spectrum, given the symbol c(/varepsilon), has been defined. This quantity is measured by the SLDD operated in nanodosimetry mode. The performance of the SLDD has been tested with a 60Co point source. The effective measurement range of the nanodosimeter is between 60 and 500 eV of energy deposition. Measured values of c(/varepsilon) are

  14. Comparison of Measured Leakage Current Distributions with Calculated Damage Energy Distributions in HgCdTe

    NASA Technical Reports Server (NTRS)

    Marshall, C. J.; Ladbury, R.; Marshall, P. W.; Reed, R. A.; Howe, C.; Weller, B.; Mendenhall, M.; Waczynski, A.; Jordan, T. M.; Fodness, B.

    2006-01-01

    This paper presents a combined Monte Carlo and analytic approach to the calculation of the pixel-to-pixel distribution of proton-induced damage in a HgCdTe sensor array and compares the results to measured dark current distributions after damage by 63 MeV protons. The moments of the Coulombic, nuclear elastic and nuclear inelastic damage distribution were extracted from Monte Carlo simulations and combined to form a damage distribution using the analytic techniques first described in [I]. The calculations show that the high energy recoils from the nuclear inelastic reactions (calculated using the Monte Car10 code MCNPX [2]) produce a pronounced skewing of the damage energy distribution. The nuclear elastic component (also calculated using the MCNPX) has a negligible effect on the shape of the damage distribution. The Coulombic contribution was calculated using MRED [3,4], a Geant4 [4,5] application. The comparison with the dark current distribution strongly suggests that mechanisms which are not linearly correlated with nonionizing damage produced according to collision kinematics are responsible for the observed dark current increases. This has important implications for the process of predicting the on-orbit dark current response of the HgCdTe sensor array.

  15. A Bio-Based Fuel Cell for Distributed Energy Generation

    SciTech Connect

    Anthony Terrinoni; Sean Gifford

    2008-06-30

    The technology we propose consists primarily of an improved design for increasing the energy density of a certain class of bio-fuel cell (BFC). The BFCs we consider are those which harvest electrons produced by microorganisms during their metabolism of organic substrates (e.g. glucose, acetate). We estimate that our technology will significantly enhance power production (per unit volume) of these BFCs, to the point where they could be employed as stand-alone systems for distributed energy generation.

  16. Thermal electron energy distribution measurements in the ionosphere.

    NASA Technical Reports Server (NTRS)

    Hays, P. B.; Nagy, A. F.

    1973-01-01

    A recoverable payload instrumented for twilight airglow studies was launched by an Aerobee 150 from the White Sands Test Range on Feb. 8, 1971 at 13.56 UT. The payload included a low energy electron spectrometer (HARP) and a cylindrical Langmuir probe. The HARP electron spectrometer is a new device designed to make high resolution differential electron flux measurements. Measurements of ionospheric electron energy distribution in the range from about 0.2 to 4.0 eV are presented.

  17. Absolute calibration in vivo measurement systems

    SciTech Connect

    Kruchten, D.A.; Hickman, D.P.

    1991-02-01

    Lawrence Livermore National Laboratory (LLNL) is currently investigating a new method for obtaining absolute calibration factors for radiation measurement systems used to measure internally deposited radionuclides in vivo. Absolute calibration of in vivo measurement systems will eliminate the need to generate a series of human surrogate structures (i.e., phantoms) for calibrating in vivo measurement systems. The absolute calibration of in vivo measurement systems utilizes magnetic resonance imaging (MRI) to define physiological structure, size, and composition. The MRI image provides a digitized representation of the physiological structure, which allows for any mathematical distribution of radionuclides within the body. Using Monte Carlo transport codes, the emission spectrum from the body is predicted. The in vivo measurement equipment is calibrated using the Monte Carlo code and adjusting for the intrinsic properties of the detection system. The calibration factors are verified using measurements of existing phantoms and previously obtained measurements of human volunteers. 8 refs.

  18. How to buy energy-efficient distribution transformer

    SciTech Connect

    1998-07-01

    Section 161 of the Energy Policy Act of 1992 (EPACT) encourages energy-efficient federal procurement. Executive Order 12902 and FAR section 23.704 direct agencies to purchase products in the upper 25% of energy efficiency. Agencies that use these guidelines to buy efficient products can realize substantial operating cost savings and help prevent pollution. As the world`s largest consumer, the federal government can help pull the entire US market towards greater energy efficiency, while saving taxpayer dollars. The efficiency levels in this Recommendation are the same as those in NEMA`s TP-1 standard. Additionally, the EPA/DOE ENERGY STAR{reg_sign} program identifies efficient low-voltage distribution transformers with the ENERGY STAR{reg_sign} label. Complying models meet the same efficiency criteria specified in this Recommendation (and TP-1).

  19. Review of Test Facilities for Distributed Energy Resources

    SciTech Connect

    AKHIL,ABBAS ALI; MARNAY,CHRIS; KIPMAN,TIMOTHY

    2003-05-01

    Since initiating research on integration of distributed energy resources (DER) in 1999, the Consortium for Electric Reliability Technology Solutions (CERTS) has been actively assessing and reviewing existing DER test facilities for possible demonstrations of advanced DER system integration concepts. This report is a compendium of information collected by the CERTS team on DER test facilities during this period.

  20. Multi-objective optimal dispatch of distributed energy resources

    NASA Astrophysics Data System (ADS)

    Longe, Ayomide

    This thesis is composed of two papers which investigate the optimal dispatch for distributed energy resources. In the first paper, an economic dispatch problem for a community microgrid is studied. In this microgrid, each agent pursues an economic dispatch for its personal resources. In addition, each agent is capable of trading electricity with other agents through a local energy market. In this paper, a simple market structure is introduced as a framework for energy trades in a small community microgrid such as the Solar Village. It was found that both sellers and buyers benefited by participating in this market. In the second paper, Semidefinite Programming (SDP) for convex relaxation of power flow equations is used for optimal active and reactive dispatch for Distributed Energy Resources (DER). Various objective functions including voltage regulation, reduced transmission line power losses, and minimized reactive power charges for a microgrid are introduced. Combinations of these goals are attained by solving a multiobjective optimization for the proposed ORPD problem. Also, both centralized and distributed versions of this optimal dispatch are investigated. It was found that SDP made the optimal dispatch faster and distributed solution allowed for scalability.

  1. Automated Energy Distribution and Reliability System (AEDR): Final Report

    SciTech Connect

    Buche, D. L.

    2008-07-01

    This report describes Northern Indiana Public Service Co. project efforts to develop an automated energy distribution and reliability system. The purpose of this project was to implement a database-driven GIS solution that would manage all of the company's gas, electric, and landbase objects.

  2. Automated Energy Distribution and Reliability System Status Report

    SciTech Connect

    Buche, D. L.; Perry, S.

    2007-10-01

    This report describes Northern Indiana Public Service Co. project efforts to develop an automated energy distribution and reliability system. The purpose of this project was to implement a database-driven GIS solution that would manage all of the company's gas, electric, and landbase objects.

  3. Measurement of Absolute Carbon Isotope Ratios: Mechanisms and Implications

    NASA Astrophysics Data System (ADS)

    Vogel, J. S.; Giacomo, J. A.; Dueker, S. R.

    2012-12-01

    An accelerator mass spectrometer (AMS) produced absolute isotope ratio measurements for 14C/13C as tested against >500 samples of NIST SRM-4990-C (OxII 14C standard) to an accuracy of 2.2±0.6‰ over a period of one year with measurements made to 1% counting statistics. The spectrometer is not maximized for 13C/12C, but measured ∂13C to 0.4±0.1‰ accuracy, with known methods for improvement. An AMS produces elemental anions from a sputter ion source and includes a charge-changing collision in a gas cell to isolate the rare 14C from the common isotopes and molecular isobars. Both these physical processes have been modeled to determine the parameters providing such absolute measures. Neutral resonant ionization in a cesium plasma produces mass-independent ionization, while velocity dependent charge-state distributions in gas collisions produce relative ion beam intensities that are linear in mass at specific collision energies. The mechanisms are not specific to carbon isotopes, but stand alone absolute IRMS (AIR-MS) instruments have not yet been made. Aside from the obvious applications in metrology, AIR-MS is particularly valuable in coupled separatory MS because no internal or external standards are required. Sample definition processes can be compared, even if no exact standard reference sample exists. Isotope dilution measurements do not require standards matching the dilution end-points and can be made over an extended, even extrapolated, range.

  4. Energy loss analysis of an integrated space power distribution system

    NASA Technical Reports Server (NTRS)

    Kankam, M. D.; Ribeiro, P. F.

    1992-01-01

    The results of studies related to conceptual topologies of an integrated utility-like space power system are described. The system topologies are comparatively analyzed by considering their transmission energy losses as functions of mainly distribution voltage level and load composition. The analysis is expedited by use of a Distribution System Analysis and Simulation (DSAS) software. This recently developed computer program by the Electric Power Research Institute (EPRI) uses improved load models to solve the power flow within the system. However, present shortcomings of the software with regard to space applications, and incompletely defined characteristics of a space power system make the results applicable to only the fundamental trends of energy losses of the topologies studied. Accountability, such as included, for the effects of the various parameters on the system performance can constitute part of a planning tool for a space power distribution system.

  5. Distributed Frequency Control of Prosumer-Based Electric Energy Systems

    SciTech Connect

    Nazari, MH; Costello, Z; Feizollahi, MJ; Grijalva, S; Egerstedt, M

    2014-11-01

    In this paper, we propose a distributed frequency regulation framework for prosumer-based electric energy systems, where a prosumer (producer-consumer) is defined as an intelligent agentwhich can produce, consume, and/or store electricity. Despite the frequency regulators being distributed, stability can be ensured while avoiding inter-area oscillations using a limited control effort. To achieve this, a fully distributed one-step model-predictive control protocol is proposed and analyzed, whereby each prosumer communicates solely with its neighbors in the network. The efficacy of the proposed frequency regulation framework is shown through simulations on two real-world electric energy systems of different scale and complexity. We show that prosumers can indeed bring frequency and power deviations to their desired values after small perturbations.

  6. Transient electron energy distribution in supported Ag nanoparticles

    NASA Astrophysics Data System (ADS)

    Merschdorf, M.; Kennerknecht, C.; Willig, K.; Pfeiffer, W.

    2002-11-01

    The electron relaxation in Ag nanoparticles supported on graphite is investigated by time-resolved multiphoton photoemission spectroscopy. The photoemission spectra map the transient electron energy distribution in the nanoparticles and reveal the internal thermalization and cooling of the electron gas. The excess energy stored in the electron gas is calculated using the free-electron model. In contrast to the behaviour of isolated nanoparticles the energy loss rate from the electron gas increases with the pump fluence. This indicates that the electron gas equilibration in Ag nanoparticles on graphite is modified by excited electron transport.

  7. Electron energy distribution in a dusty plasma: analytical approach.

    PubMed

    Denysenko, I B; Kersten, H; Azarenkov, N A

    2015-09-01

    Analytical expressions describing the electron energy distribution function (EEDF) in a dusty plasma are obtained from the homogeneous Boltzmann equation for electrons. The expressions are derived neglecting electron-electron collisions, as well as transformation of high-energy electrons into low-energy electrons at inelastic electron-atom collisions. At large electron energies, the quasiclassical approach for calculation of the EEDF is applied. For the moderate energies, we account for inelastic electron-atom collisions in the dust-free case and both inelastic electron-atom and electron-dust collisions in the dusty plasma case. Using these analytical expressions and the balance equation for dust charging, the electron energy distribution function, the effective electron temperature, the dust charge, and the dust surface potential are obtained for different dust radii and densities, as well as for different electron densities and radio-frequency (rf) field amplitudes and frequencies. The dusty plasma parameters are compared with those calculated numerically by a finite-difference method taking into account electron-electron collisions and the transformation of high-energy electrons at inelastic electron-neutral collisions. It is shown that the analytical expressions can be used for calculation of the EEDF and dusty plasma parameters at typical experimental conditions, in particular, in the positive column of a direct-current glow discharge and in the case of an rf plasma maintained by an electric field with frequency f=13.56MHz. PMID:26465570

  8. Strain energy release rate distributions for double cantilever beam specimens

    NASA Technical Reports Server (NTRS)

    Crews, J. H., Jr.; Shivakumar, K. N.; Raju, I. S.

    1991-01-01

    A 24-ply composite double cantilever-beam specimen under mode I (opening) loading has been analyzed by a 3D FEM code that calculated along a straight delamination starter for several different specimen materials. An isotropic specimen was found to have a strain-energy release rate distribution which varied along its delamination front due to the boundary-layer effect and another effect associated with the anticlastic curvature of the bent specimen arms. A 0-deg graphite-reinforced epoxy specimen had a nearly-uniform strain-energy release rate distribution which dropped only near the edge, due to the boundary-layer effect, and a +/- 45-deg graphite/epoxy specimen exhibited a pronounced strain-energy release rate variation across the specimen width.

  9. Benefits of Power Electronic Interfaces for Distributed Energy Systems

    SciTech Connect

    Kroposki, B.; Pink, C.; DeBlasio, R.; Thomas, H.; Simoes, M.; Sen, P. K.

    2006-01-01

    Optimization of overall electrical system performance is important for the long-term economic viability of distributed energy (DE) systems. With the increasing use of DE systems in industry and its technological advancement, it is becoming more important to understand the integration of these systems with the electric power systems. New markets and benefits for distributed energy applications include the ability to provide ancillary services, improve energy efficiency, enhance power system reliability, and allow customer choice. Advanced power electronic (PE) interfaces will allow DE systems to provide increased functionality through improved power quality and voltage/VAR support, increase electrical system compatibility by reducing the fault contributions, and flexibility in operations with various other DE sources, while reducing overall interconnection costs. This paper examines the system integration and optimization issues associated with DE systems and show the benefits of using PE interfaces for such applications.

  10. 78 FR 23335 - Energy Conservation Program: Energy Conservation Standards for Distribution Transformers

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-18

    ...The Energy Policy and Conservation Act of 1975 (EPCA), as amended, prescribes energy conservation standards for various consumer products and certain commercial and industrial equipment, including distribution transformers. EPCA also requires the U.S. Department of Energy (DOE) to determine whether more-stringent standards would be technologically feasible and economically justified, and would......

  11. Optimal Voltage Regulation for Unbalanced Distribution Networks Considering Distributed Energy Resources

    SciTech Connect

    Liu, Guodong; Ceylan, Oguzhan; Xu, Yan; Tomsovic, Kevin

    2015-01-01

    With increasing penetration of distributed generation in the distribution networks (DN), the secure and optimal operation of DN has become an important concern. In this paper, an iterative quadratic constrained quadratic programming model to minimize voltage deviations and maximize distributed energy resource (DER) active power output in a three phase unbalanced distribution system is developed. The optimization model is based on the linearized sensitivity coefficients between controlled variables (e.g., node voltages) and control variables (e.g., real and reactive power injections of DERs). To avoid the oscillation of solution when it is close to the optimum, a golden search method is introduced to control the step size. Numerical simulations on modified IEEE 13 nodes test feeders show the efficiency of the proposed model. Compared to the results solved by heuristic search (harmony algorithm), the proposed model converges quickly to the global optimum.

  12. Distributed energy resources at naval base ventura county building 1512

    SciTech Connect

    Bailey, Owen C.; Marnay, Chris

    2004-10-01

    This paper reports the findings of a preliminary assessment of the cost effectiveness of distributed energy resources at Naval Base Ventura County (NBVC) Building 1512. This study was conducted in response to the base's request for design assistance to the Federal Energy Management Program. Given the current tariff structure there are two main decisions facing NBVC: whether to install distributed energy resources (DER), or whether to continue the direct access energy supply contract. At the current effective rate, given assumptions about the performance and structure of building energy loads and available generating technology characteristics, the results of this study indicate that if the building installed a 600 kW DER system with absorption cooling and heat capabilities chosen by cost minimization, the energy cost savings would be about 14 percent, or $55,000 per year. However, under current conditions, this study also suggests that significant savings could be obtained if Building 1 512 changed from the direct access contract to a SCE TOU-8 (Southern California Edison time of use tariff number 8) rate without installing a DER system. At current SCE TOU-8 tariffs, the potential savings from installation of a DER system would be about 4 percent, or $15,000 per year.

  13. Steam distribution and energy delivery optimization using wireless sensors

    SciTech Connect

    Olama, Mohammed M; Allgood, Glenn O; Kuruganti, Phani Teja; Sukumar, Sreenivas R; Djouadi, Seddik M; Lake, Joe E

    2011-01-01

    The Extreme Measurement Communications Center at Oak Ridge National Laboratory (ORNL) explores the deployment of a wireless sensor system with a real-time measurement-based energy efficiency optimization framework in the ORNL campus. With particular focus on the 12-mile long steam distribution network in our campus, we propose an integrated system-level approach to optimize the energy delivery within the steam distribution system. We address the goal of achieving significant energy-saving in steam lines by monitoring and acting on leaking steam valves/traps. Our approach leverages an integrated wireless sensor and real-time monitoring capabilities. We make assessments on the real-time status of the distribution system by mounting acoustic sensors on the steam pipes/traps/valves and observe the state measurements of these sensors. Our assessments are based on analysis of the wireless sensor measurements. We describe Fourier-spectrum based algorithms that interpret acoustic vibration sensor data to characterize flows and classify the steam system status. We are able to present the sensor readings, steam flow, steam trap status and the assessed alerts as an interactive overlay within a web-based Google Earth geographic platform that enables decision makers to take remedial action. We believe our demonstration serves as an instantiation of a platform that extends implementation to include newer modalities to manage water flow, sewage and energy consumption.

  14. Steam distribution and energy delivery optimization using wireless sensors

    NASA Astrophysics Data System (ADS)

    Olama, Mohammed M.; Allgood, Glenn O.; Kuruganti, Teja P.; Sukumar, Sreenivas R.; Djouadi, Seddik M.; Lake, Joe E.

    2011-05-01

    The Extreme Measurement Communications Center at Oak Ridge National Laboratory (ORNL) explores the deployment of a wireless sensor system with a real-time measurement-based energy efficiency optimization framework in the ORNL campus. With particular focus on the 12-mile long steam distribution network in our campus, we propose an integrated system-level approach to optimize the energy delivery within the steam distribution system. We address the goal of achieving significant energy-saving in steam lines by monitoring and acting on leaking steam valves/traps. Our approach leverages an integrated wireless sensor and real-time monitoring capabilities. We make assessments on the real-time status of the distribution system by mounting acoustic sensors on the steam pipes/traps/valves and observe the state measurements of these sensors. Our assessments are based on analysis of the wireless sensor measurements. We describe Fourier-spectrum based algorithms that interpret acoustic vibration sensor data to characterize flows and classify the steam system status. We are able to present the sensor readings, steam flow, steam trap status and the assessed alerts as an interactive overlay within a web-based Google Earth geographic platform that enables decision makers to take remedial action. We believe our demonstration serves as an instantiation of a platform that extends implementation to include newer modalities to manage water flow, sewage and energy consumption.

  15. Initial energy and perihelion distributions of Oort-cloud comets

    NASA Technical Reports Server (NTRS)

    Weissman, P. R.

    1977-01-01

    A Monte Carlo model of stellar perturbations of the Oort cloud is used to study the distributions in energy and perihelion of comets entering the planetary region for the first time. The model is run for a variety of initial states and a range of velocity perturbations. In all cases the resulting orbits are uniformly distributed in perihelion distance in the planetary region, q less than 20 AU. Most orbits are confined to a fairly narrow range in 1/a and hyperbolic orbits are rare.

  16. Energy management and control of active distribution systems

    NASA Astrophysics Data System (ADS)

    Shariatzadeh, Farshid

    Advancements in the communication, control, computation and information technologies have driven the transition to the next generation active power distribution systems. Novel control techniques and management strategies are required to achieve the efficient, economic and reliable grid. The focus of this work is energy management and control of active distribution systems (ADS) with integrated renewable energy sources (RESs) and demand response (DR). Here, ADS mean automated distribution system with remotely operated controllers and distributed energy resources (DERs). DER as active part of the next generation future distribution system includes: distributed generations (DGs), RESs, energy storage system (ESS), plug-in hybrid electric vehicles (PHEV) and DR. Integration of DR and RESs into ADS is critical to realize the vision of sustainability. The objective of this dissertation is the development of management architecture to control and operate ADS in the presence of DR and RES. One of the most challenging issues for operating ADS is the inherent uncertainty of DR and RES as well as conflicting objective of DER and electric utilities. ADS can consist of different layers such as system layer and building layer and coordination between these layers is essential. In order to address these challenges, multi-layer energy management and control architecture is proposed with robust algorithms in this work. First layer of proposed multi-layer architecture have been implemented at the system layer. Developed AC optimal power flow (AC-OPF) generates fair price for all DR and non-DR loads which is used as a control signal for second layer. Second layer controls DR load at buildings using a developed look-ahead robust controller. Load aggregator collects information from all buildings and send aggregated load to the system optimizer. Due to the different time scale at these two management layers, time coordination scheme is developed. Robust and deterministic controllers

  17. STANDARDIZING TYPE Ia SUPERNOVA ABSOLUTE MAGNITUDES USING GAUSSIAN PROCESS DATA REGRESSION

    SciTech Connect

    Kim, A. G.; Aldering, G.; Aragon, C.; Bailey, S.; Childress, M.; Fakhouri, H. K.; Nordin, J.; Thomas, R. C.; Antilogus, P.; Bongard, S.; Canto, A.; Cellier-Holzem, F.; Guy, J.; Baltay, C.; Buton, C.; Kerschhaggl, M.; Kowalski, M.; Chotard, N.; Copin, Y.; Gangler, E.; and others

    2013-04-01

    We present a novel class of models for Type Ia supernova time-evolving spectral energy distributions (SEDs) and absolute magnitudes: they are each modeled as stochastic functions described by Gaussian processes. The values of the SED and absolute magnitudes are defined through well-defined regression prescriptions, so that data directly inform the models. As a proof of concept, we implement a model for synthetic photometry built from the spectrophotometric time series from the Nearby Supernova Factory. Absolute magnitudes at peak B brightness are calibrated to 0.13 mag in the g band and to as low as 0.09 mag in the z = 0.25 blueshifted i band, where the dispersion includes contributions from measurement uncertainties and peculiar velocities. The methodology can be applied to spectrophotometric time series of supernovae that span a range of redshifts to simultaneously standardize supernovae together with fitting cosmological parameters.

  18. Absolute Energy Calibration of X-ray TESs with 0.04 eV Uncertainty at 6.4 keV in a Hadron-Beam Environment

    NASA Astrophysics Data System (ADS)

    Tatsuno, H.; Doriese, W. B.; Bennett, D. A.; Curceanu, C.; Fowler, J. W.; Gard, J.; Gustafsson, F. P.; Hashimoto, T.; Hayano, R. S.; Hays-Wehle, J. P.; Hilton, G. C.; Iliescu, M.; Ishimoto, S.; Itahashi, K.; Iwasaki, M.; Kuwabara, K.; Ma, Y.; Marton, J.; Noda, H.; O'Neil, G. C.; Okada, S.; Outa, H.; Reintsema, C. D.; Sato, M.; Schmidt, D. R.; Shi, H.; Suzuki, K.; Suzuki, T.; Uhlig, J.; Ullom, J. N.; Widmann, E.; Yamada, S.; Zmeskal, J.; Swetz, D. S.

    2016-01-01

    A performance evaluation of superconducting transition-edge sensors (TESs) in the environment of a pion beam line at a particle accelerator is presented. Averaged across the 209 functioning sensors in the array, the achieved energy resolution is 5.2 eV FWHM at Co K_{α } (6.9 keV) when the pion beam is off and 7.3 eV at a beam rate of 1.45 MHz. Absolute energy uncertainty of ± 0.04 eV is demonstrated for Fe K_{α } (6.4 keV) with in-situ energy calibration obtained from other nearby known X-ray lines. To achieve this small uncertainty, it is essential to consider the non-Gaussian energy response of the TESs and thermal cross-talk pile-up effects due to charged particle hits in the silicon substrate of the TES array.

  19. Absolute Energy Calibration of X-ray TESs with 0.04 eV Uncertainty at 6.4 keV in a Hadron-Beam Environment

    NASA Astrophysics Data System (ADS)

    Tatsuno, H.; Doriese, W. B.; Bennett, D. A.; Curceanu, C.; Fowler, J. W.; Gard, J.; Gustafsson, F. P.; Hashimoto, T.; Hayano, R. S.; Hays-Wehle, J. P.; Hilton, G. C.; Iliescu, M.; Ishimoto, S.; Itahashi, K.; Iwasaki, M.; Kuwabara, K.; Ma, Y.; Marton, J.; Noda, H.; O'Neil, G. C.; Okada, S.; Outa, H.; Reintsema, C. D.; Sato, M.; Schmidt, D. R.; Shi, H.; Suzuki, K.; Suzuki, T.; Uhlig, J.; Ullom, J. N.; Widmann, E.; Yamada, S.; Zmeskal, J.; Swetz, D. S.

    2016-08-01

    A performance evaluation of superconducting transition-edge sensors (TESs) in the environment of a pion beam line at a particle accelerator is presented. Averaged across the 209 functioning sensors in the array, the achieved energy resolution is 5.2 eV FWHM at Co K_{α } (6.9 keV) when the pion beam is off and 7.3 eV at a beam rate of 1.45 MHz. Absolute energy uncertainty of ± 0.04 eV is demonstrated for Fe K_{α } (6.4 keV) with in-situ energy calibration obtained from other nearby known X-ray lines. To achieve this small uncertainty, it is essential to consider the non-Gaussian energy response of the TESs and thermal cross-talk pile-up effects due to charged particle hits in the silicon substrate of the TES array.

  20. Energy efficient wireless sensor networks using asymmetric distributed source coding

    NASA Astrophysics Data System (ADS)

    Rao, Abhishek; Kulkarni, Murlidhar

    2013-01-01

    Wireless Sensor Networks (WSNs) are networks of sensor nodes deployed over a geographical area to perform a specific task. WSNs pose many design challenges. Energy conservation is one such design issue. In literature a wide range of solutions addressing this issue have been proposed. Generally WSNs are densely deployed. Thus the nodes with the close proximity are more likely to have the same data. Transmission of such non-aggregated data may lead to an inefficient energy management. Hence the data fusion has to be performed at the nodes so as to combine the edundant information into a single data unit. Distributed Source Coding is an efficient approach in achieving this task. In this paper an attempt has been made in modeling such a system. Various energy efficient codes were considered for the analysis. System performance in terms of energy efficiency has been made.

  1. On Measuring Cosmic Ray Energy Spectra with the Rapidity Distributions

    NASA Technical Reports Server (NTRS)

    Bashindzhagyan, G.; Adams, J.; Chilingarian, A.; Drury, L.; Egorov, N.; Golubkov, S.; Korotkova, N.; Panasyuk, M.; Podorozhnyi, D.; Procqureur, J.

    2000-01-01

    An important goal of cosmic ray research is to measure the elemental energy spectra of galactic cosmic rays up to 10(exp 16) eV. This goal cannot be achieved with an ionization calorimeter because the required instrument is too massive for space flight. An alternate method will be presented. This method is based on measuring the primary particle energy by determining the angular distribution of secondaries produced in a target layer. The proposed technique can be used over a wide range of energies (10 (exp 11) -10 (exp 16) eV) and gives an energy resolution of 60% or better. Based on this technique, a conceptual design for a new instrument (KLEM) will be presented. Due to its light weight, this instrument can have a large aperture enabling the direct measurement of cosmic rays to 1016 eV.

  2. Kinetic-Energy Distribution of D(2p) Atoms from Analysis of the D Lyman-Alpha Line Profile

    NASA Technical Reports Server (NTRS)

    Ciocca, M.; Ajello, Joseph M.; Liu, Xianming; Maki, Justin

    1997-01-01

    The kinetic-energy distribution of D(2p) atoms resulting from electron-impact dissociation of D2 has been measured. A high-resolution vacuum ultraviolet spectrometer was employed for the first measurement of the D Lyman-alpha (D L(alpha)) emission line profiles at 20- and 100-eV excitation energies. Analysis of the deconvoluted line profile of D L(alpha) at 100 eV reveals the existence of a narrow line central peak of 29+/-2 mA full width at half maximum and a broad pedestal wing structure about 190 mA wide. The wings of the line can be used to determine the fast atom distribution. The wings of D L(alpha) arise from dissociative excitation of a series of doubly excited states that cross the Franck-Condon region between 23 and 40 eV. The fast atom distribution at 100-eV electron impact energy spans the energy range from 1 to 10 eV with a peak value near 6 eV. Slow D(2p) atoms characterized by a distribution function with peak energy near 100 meV produce the central peak profile, which is nearly independent of the impact energy. The deconvoluted line profiles of the central peak at 20 eV for dissociative excitation of D2 and H2 are fitted with an analytical function for use in calibration of space flight instrumentation equipped with a D/H absorption cell. The kinetic-energy and line profile results are compared to similar measurements for H2. The absolute cross sections for the line center (slow atoms) and wings (fast atoms) and total emission line profile were measured from threshold to 400 eV. Analytical model coefficients are given for the energy dependence of the measured slow atom cross section.

  3. A bolometer array for the spectral energy distribution (SPEED) camera

    NASA Astrophysics Data System (ADS)

    Silverberg, R. F.; Ali, S.; Bier, A.; Campano, B.; Chen, T. C.; Cheng, E. S.; Cottingham, D. A.; Crawford, T. M.; Downes, T.; Finkbeiner, F. M.; Fixsen, D. J.; Logan, D.; Meyer, S. S.; O'dell, C.; Perera, T.; Sharp, E. H.; Timbie, P. T.; Wilson, G. W.

    2004-03-01

    The Spectral Energy Distribution (SPEED) Camera is being developed to study the spectral energy distributions of high redshift galaxies. Its initial use will be on the Heinrich Hertz Telescope and eventually on the Large Millimeter Telescope. SPEED requires a small cryogenic detector array of 2×2 pixels with each pixel having four frequency bands in the 150-375GHz range. Here we describe the development of the detector array of these high-efficiency Frequency Selective Bolometers (FSB). The FSB design provides the multi-pixel, multi-spectral band capability required for SPEED in a compact stackable array. The SPEED bolometers will use proximity effect superconducting transition edge sensors as their temperature-sensing element, allowing for higher levels of electronic multiplexing in future applications.

  4. Consistent energy barrier distributions in magnetic particle chains

    NASA Astrophysics Data System (ADS)

    Laslett, O.; Ruta, S.; Chantrell, R. W.; Barker, J.; Friedman, G.; Hovorka, O.

    2016-04-01

    We investigate long-time thermal activation behaviour in magnetic particle chains of variable length. Chains are modelled as Stoner-Wohlfarth particles coupled by dipolar interactions. Thermal activation is described as a hopping process over a multidimensional energy landscape using the discrete orientation model limit of the Landau-Lifshitz-Gilbert dynamics. The underlying master equation is solved by diagonalising the associated transition matrix, which allows the evaluation of distributions of time scales of intrinsic thermal activation modes and their energy representation. It is shown that as a result of the interaction dependence of these distributions, increasing the particle chain length can lead to acceleration or deceleration of the overall relaxation process depending on the initialisation procedure.

  5. Detecting energy dependent neutron capture distributions in a liquid scintillator

    NASA Astrophysics Data System (ADS)

    Balmer, Matthew J. I.; Gamage, Kelum A. A.; Taylor, Graeme C.

    2015-03-01

    A novel technique is being developed to estimate the effective dose of a neutron field based on the distribution of neutron captures in a scintillator. Using Monte Carlo techniques, a number of monoenergetic neutron source energies and locations were modelled and their neutron capture response was recorded. Using back propagation Artificial Neural Networks (ANN) the energy and incident direction of the neutron field was predicted from the distribution of neutron captures within a 6Li-loaded liquid scintillator. Using this proposed technique, the effective dose of 252Cf, 241AmBe and 241AmLi neutron fields was estimated to within 30% for four perpendicular angles in the horizontal plane. Initial theoretical investigations show that this technique holds some promise for real-time estimation of the effective dose of a neutron field.

  6. Absolute Identification by Relative Judgment

    ERIC Educational Resources Information Center

    Stewart, Neil; Brown, Gordon D. A.; Chater, Nick

    2005-01-01

    In unidimensional absolute identification tasks, participants identify stimuli that vary along a single dimension. Performance is surprisingly poor compared with discrimination of the same stimuli. Existing models assume that identification is achieved using long-term representations of absolute magnitudes. The authors propose an alternative…

  7. Be Resolute about Absolute Value

    ERIC Educational Resources Information Center

    Kidd, Margaret L.

    2007-01-01

    This article explores how conceptualization of absolute value can start long before it is introduced. The manner in which absolute value is introduced to students in middle school has far-reaching consequences for their future mathematical understanding. It begins to lay the foundation for students' understanding of algebra, which can change…

  8. Modeling Plasmas with a Kappa Electron Energy Distribution

    NASA Astrophysics Data System (ADS)

    Hahn, Michael; Savin, Daniel Wolf

    2016-05-01

    Nonthermal kappa electron energy distributions have been observed in the Earth's magnetosphere and the solar wind, and are likely also present in the solar corona and in solar flares. In order to model the spectra of these plasmas, it is necessary to obtain the appropriate collision rate coefficients. We show that this can be done simply by summing appropriately weighted Maxwellian rate coefficients. The resulting data have similar or better accuracies than are obtained with other approaches. Summing Maxwellians has the additional advantages of being easy to implement and extendable to many different collision processes. We apply this technique to modeling the charge state distribution (CSD) of kappa-distribution plasmas. In particular, we examine the influence of electron impact multiple ionization on the equilibrium CSD and calculate the time variation of the CSD during a solar flare.

  9. Modeling Plasmas with a Kappa Electron Energy Distribution

    NASA Astrophysics Data System (ADS)

    Hahn, Michael; Savin, Daniel Wolf

    2016-06-01

    Nonthermal kappa electron energy distributions have been observed in the Earth's magnetosphere and the solar wind, and are likely also present in the solar corona and in solar flares. In order to model the spectra of these plasmas, it is necessary to obtain the appropriate collision rate coefficients. We show that this can be done simply by summing appropriately weighted Maxwellian rate coefficients. The resulting data have similar or better accuracies than are obtained with other approaches. Summing Maxwellians has the additional advantages of being easy to implement and extendable to many different collision processes. We apply this technique to modeling the charge state distribution (CSD) of kappa-distribution plasmas. In particular, we examine the influence of electron impact multiple ionization on the equilibrium CSD and calculate the time variation of the CSD during a solar flare.

  10. A Detailed Level Kinetics Model of NO Vibrational Energy Distributions

    NASA Technical Reports Server (NTRS)

    Sharma, Surendra P.; Gilmore, John; Cavolowsky, John A. (Technical Monitor)

    1996-01-01

    Several contemporary problems have pointed to the desirability of a detailed level kinetics approach to modeling the distribution of vibrational energy in NO. Such a model is necessary when vibrational redistribution reactions are insufficient to maintain a Boltzmann distribution over the vibrational energy states. Recent calculations of the rate constant for the first reaction of the Zeldovich mechanism (N2 + O (goes to) NO + N) have suggested that the product NO is formed in high vibrational states. In shock layer flowfields, the product NO molecules may experience an insufficient number of collisions to establish a Boltzmann distribution over vibrational states, thus necessitating a level kinetics model. In other flows, such as expansions of high temperature air, fast, near-resonance vibrational energy exchanges with N2 and O2 may also require a level specific model for NO because of the relative rates of vibrational exchange and redistribution. The proposed report will integrate computational and experimental components to construct such a model for the NO molecule.

  11. Determination of the polar and total surface energy distributions of particulates by inverse gas chromatography.

    PubMed

    Das, Shyamal C; Larson, Ian; Morton, David A V; Stewart, Peter J

    2011-01-18

    This Letter reports a technique of measuring polar surface energy distributions of lactose using inverse gas chromatography (IGC). The significance of this study is that the total surface energy distributions can now be characterized by combining the already known dispersive surface energy distribution with polar surface energy distribution determined in this study. The polar surface energy was calculated from the specific free energies for surface interactions with a monopolar basic probe, ethyl acetate, and a monopolar acidic probe, dichloromethane. PMID:21174410

  12. Network Capacity Assessment of CHP-based Distributed Generation on Urban Energy Distribution Networks

    NASA Astrophysics Data System (ADS)

    Zhang, Xianjun

    The combined heat and power (CHP)-based distributed generation (DG) or dis-tributed energy resources (DERs) are mature options available in the present energy market, considered to be an effective solution to promote energy efficiency. In the urban environment, the electricity, water and natural gas distribution networks are becoming increasingly interconnected with the growing penetration of the CHP-based DG. Subsequently, this emerging interdependence leads to new topics meriting serious consideration: how much of the CHP-based DG can be accommodated and where to locate these DERs, and given preexisting constraints, how to quantify the mutual impacts on operation performances between these urban energy distribution networks and the CHP-based DG. The early research work was conducted to investigate the feasibility and design methods for one residential microgrid system based on existing electricity, water and gas infrastructures of a residential community, mainly focusing on the economic planning. However, this proposed design method cannot determine the optimal DG sizing and siting for a larger test bed with the given information of energy infrastructures. In this context, a more systematic as well as generalized approach should be developed to solve these problems. In the later study, the model architecture that integrates urban electricity, water and gas distribution networks, and the CHP-based DG system was developed. The proposed approach addressed the challenge of identifying the optimal sizing and siting of the CHP-based DG on these urban energy networks and the mutual impacts on operation performances were also quantified. For this study, the overall objective is to maximize the electrical output and recovered thermal output of the CHP-based DG units. The electricity, gas, and water system models were developed individually and coupled by the developed CHP-based DG system model. The resultant integrated system model is used to constrain the DG's electrical

  13. Energy distribution of elastically scattered electrons from double layer samples

    NASA Astrophysics Data System (ADS)

    Tőkési, K.; Varga, D.

    2016-02-01

    We present a theoretical description of the spectra of electrons elastically scattered from thin double layered Au-C samples. The analysis is based on the Monte Carlo simulation of the recoil and Doppler effects in reflection and transmission geometries of the scattering at a fixed angle of 44.3 ° and a primary energy of 40 keV. The relativistic correction is taken into account. Besides the experimentally measurable energy distributions the simulations give many partial distributions separately, depending on the number of elastic scatterings (single, and multiple scatterings of different types). Furthermore, we present detailed analytical calculations for the main parameters of the single scattering, taking into account both the ideal scattering geometry, i.e. infinitesimally small angular range, and the effect of the real, finite angular range used in the measurements. We show our results for intensity ratios, peak shifts and broadenings for four cases of measurement geometries and layer thicknesses. While in the peak intensity ratios of gold and carbon for transmission geometries were found to be in good agreement with the results of the single scattering model, especially large deviations were obtained in reflection geometries. The separation of the peaks, depending on the geometry and the thickness, generally smaller, and the peak width generally larger than it can be expected from the nominal values of the primary energy, scattering angle, and mean kinetic energy of the atoms. We also show that the peaks are asymmetric even for the case of the single scattering due to the finite solid angle. Finally, we present a qualitative comparison with the experimental data. We find our resulting energy distribution of elastically scattered electrons to be in good agreement with recent measurements.

  14. Topography, energy and the global distribution of bird species richness

    PubMed Central

    Davies, Richard G; Orme, C. David L; Storch, David; Olson, Valerie A; Thomas, Gavin H; Ross, Simon G; Ding, Tzung-Su; Rasmussen, Pamela C; Bennett, Peter M; Owens, Ian P.F; Blackburn, Tim M; Gaston, Kevin J

    2007-01-01

    A major goal of ecology is to determine the causes of the latitudinal gradient in global distribution of species richness. Current evidence points to either energy availability or habitat heterogeneity as the most likely environmental drivers in terrestrial systems, but their relative importance is controversial in the absence of analyses of global (rather than continental or regional) extent. Here we use data on the global distribution of extant continental and continental island bird species to test the explanatory power of energy availability and habitat heterogeneity while simultaneously addressing issues of spatial resolution, spatial autocorrelation, geometric constraints upon species' range dynamics, and the impact of human populations and historical glacial ice-cover. At the finest resolution (1°), topographical variability and temperature are identified as the most important global predictors of avian species richness in multi-predictor models. Topographical variability is most important in single-predictor models, followed by productive energy. Adjusting for null expectations based on geometric constraints on species richness improves overall model fit but has negligible impact on tests of environmental predictors. Conclusions concerning the relative importance of environmental predictors of species richness cannot be extrapolated from one biogeographic realm to others or the globe. Rather a global perspective confirms the primary importance of mountain ranges in high-energy areas. PMID:17311781

  15. Validated modeling of distributed energy resources at distribution voltages : LDRD project 38672.

    SciTech Connect

    Ralph, Mark E.; Ginn, Jerry W.

    2004-03-01

    A significant barrier to the deployment of distributed energy resources (DER) onto the power grid is uncertainty on the part of utility engineers regarding impacts of DER on their distribution systems. Because of the many possible combinations of DER and local power system characteristics, these impacts can most effectively be studied by computer simulation. The goal of this LDRD project was to develop and experimentally validate models of transient and steady state source behavior for incorporation into utility distribution analysis tools. Development of these models had not been prioritized either by the distributed-generation industry or by the inverter industry. A functioning model of a selected inverter-based DER was developed in collaboration with both the manufacturer and industrial power systems analysts. The model was written in the PSCAD simulation language, a variant of the ElectroMagnetic Transients Program (EMTP), a code that is widely used and accepted by utilities. A stakeholder team was formed and a methodology was established to address the problem. A list of detailed DER/utility interaction concerns was developed and prioritized. The list indicated that the scope of the problem significantly exceeded resources available for this LDRD project. As this work progresses under separate funding, the model will be refined and experimentally validated. It will then be incorporated in utility distribution analysis tools and used to study a variety of DER issues. The key next step will be design of the validation experiments.

  16. Optimal Control of Distributed Energy Resources using Model Predictive Control

    SciTech Connect

    Mayhorn, Ebony T.; Kalsi, Karanjit; Elizondo, Marcelo A.; Zhang, Wei; Lu, Shuai; Samaan, Nader A.; Butler-Purry, Karen

    2012-07-22

    In an isolated power system (rural microgrid), Distributed Energy Resources (DERs) such as renewable energy resources (wind, solar), energy storage and demand response can be used to complement fossil fueled generators. The uncertainty and variability due to high penetration of wind makes reliable system operations and controls challenging. In this paper, an optimal control strategy is proposed to coordinate energy storage and diesel generators to maximize wind penetration while maintaining system economics and normal operation. The problem is formulated as a multi-objective optimization problem with the goals of minimizing fuel costs and changes in power output of diesel generators, minimizing costs associated with low battery life of energy storage and maintaining system frequency at the nominal operating value. Two control modes are considered for controlling the energy storage to compensate either net load variability or wind variability. Model predictive control (MPC) is used to solve the aforementioned problem and the performance is compared to an open-loop look-ahead dispatch problem. Simulation studies using high and low wind profiles, as well as, different MPC prediction horizons demonstrate the efficacy of the closed-loop MPC in compensating for uncertainties in wind and demand.

  17. Controlling the Electron Energy Distribution Function Using an Anode

    NASA Astrophysics Data System (ADS)

    Baalrud, Scott D.; Barnat, Edward V.; Hopkins, Mathew M.

    2014-10-01

    Positively biased electrodes inserted into plasmas influence the electron energy distribution function (EEDF) by providing a sink for low energy electrons that would otherwise be trapped by ion sheaths at the chamber walls. We develop a model for the EEDF in a hot filament generated discharge in the presence of positively biased electrodes of various surface areas, and compare the model results with experimental Langmuir probe measurements and particle-in-cell simulations. In the absence of an anode, the EEDF is characterized by a cool trapped population at energies below the sheath energy, and a comparatively warm tail population associated with the filament primaries. Anodes that are small enough to collect a negligible fraction of the electrons exiting the plasma have little affect on the EEDF, but as the anode area approaches √{me /mi }Aw , where Aw is the chamber wall area, the anode collects most of the electrons leaving the plasma. This drastically reduces the density of the otherwise trapped population, causing an effective heating of the electrons and a corresponding density decrease. A global model is developed based on the EEDF model and current balance, which shows the interconnected nature of the electron temperature, density and the plasma potential. This work was supported by the Office of Fusion Energy Science at the U.S. Department of Energy under Contract DE-AC04-94SL85000, and by the University of Iowa Old Gold Program.

  18. Effect of the electron energy distribution on total energy loss with argon in inductively coupled plasmas

    SciTech Connect

    Kim, June Young; Kim, Young-Cheol; Kim, Yu-Sin; Chung, Chin-Wook

    2015-01-15

    The total energy lost per electron-ion pair lost ε{sub T} is investigated with the electron energy distribution function (EEDF). The EEDFs are measured at various argon powers in RF inductively coupled plasma, and the EEDFs show a depleted distribution (a discontinuity occurring at the minimum argon excitation threshold energy level) with the bulk temperature and the tail temperature. The total energy loss per electron-ion pair lost ε{sub T} is calculated from a power balance model with the Maxwellian EEDFs and the depleted EEDFs and then compared with the measured ε{sub T} from the floating probe. It is concluded that the small population of the depleted high energy electrons dramatically increases the collisional energy loss, and the calculated ε{sub T} from the depleted EEDFs has a value that is similar to the measured ε{sub T}.

  19. Effect of the electron energy distribution on total energy loss with argon in inductively coupled plasmas

    NASA Astrophysics Data System (ADS)

    Kim, June Young; Kim, Young-Cheol; Kim, Yu-Sin; Chung, Chin-Wook

    2015-01-01

    The total energy lost per electron-ion pair lost ɛT is investigated with the electron energy distribution function (EEDF). The EEDFs are measured at various argon powers in RF inductively coupled plasma, and the EEDFs show a depleted distribution (a discontinuity occurring at the minimum argon excitation threshold energy level) with the bulk temperature and the tail temperature. The total energy loss per electron-ion pair lost ɛT is calculated from a power balance model with the Maxwellian EEDFs and the depleted EEDFs and then compared with the measured ɛT from the floating probe. It is concluded that the small population of the depleted high energy electrons dramatically increases the collisional energy loss, and the calculated ɛT from the depleted EEDFs has a value that is similar to the measured ɛT.

  20. Modeling of customer adoption of distributed energy resources

    SciTech Connect

    Marnay, Chris; Chard, Joseph S.; Hamachi, Kristina S.; Lipman, Timothy; Moezzi, Mithra M.; Ouaglal, Boubekeur; Siddiqui, Afzal S.

    2001-08-01

    This report describes work completed for the California Energy Commission (CEC) on the continued development and application of the Distributed Energy Resources Customer Adoption Model (DER-CAM). This work was performed at Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab) between July 2000 and June 2001 under the Consortium for Electric Reliability Technology Solutions (CERTS) Distributed Energy Resources Integration (DERI) project. Our research on distributed energy resources (DER) builds on the concept of the microgrid ({mu}Grid), a semiautonomous grouping of electricity-generating sources and end-use sinks that are placed and operated for the benefit of its members. Although a {mu}Grid can operate independent of the macrogrid (the utility power network), the {mu}Grid is usually interconnected, purchasing energy and ancillary services from the macrogrid. Groups of customers can be aggregated into {mu}Grids by pooling their electrical and other loads, and the most cost-effective combination of generation resources for a particular {mu}Grid can be found. In this study, DER-CAM, an economic model of customer DER adoption implemented in the General Algebraic Modeling System (GAMS) optimization software is used, to find the cost-minimizing combination of on-site generation customers (individual businesses and a {mu}Grid) in a specified test year. DER-CAM's objective is to minimize the cost of supplying electricity to a specific customer by optimizing the installation of distributed generation and the self-generation of part or all of its electricity. Currently, the model only considers electrical loads, but combined heat and power (CHP) analysis capability is being developed under the second year of CEC funding. The key accomplishments of this year's work were the acquisition of increasingly accurate data on DER technologies, including the development of methods for forecasting cost reductions for these technologies, and the creation of a credible

  1. Metallic Magnetic Calorimeters for Absolute Activity Measurement

    NASA Astrophysics Data System (ADS)

    Loidl, M.; Leblanc, E.; Rodrigues, M.; Bouchard, J.; Censier, B.; Branger, T.; Lacour, D.

    2008-05-01

    We present a prototype of metallic magnetic calorimeters that we are developing for absolute activity measurements of low energy emitting radionuclides. We give a detailed description of the realization of the prototype, containing an 55Fe source inside the detector absorber. We present the analysis of first data taken with this detector and compare the result of activity measurement with liquid scintillation counting. We also propose some ways for reducing the uncertainty on the activity determination with this new technique.

  2. Modelling Framework and the Quantitative Analysis of Distributed Energy Resources in Future Distribution Networks

    NASA Astrophysics Data System (ADS)

    Han, Xue; Sandels, Claes; Zhu, Kun; Nordström, Lars

    2013-08-01

    There has been a large body of statements claiming that the large-scale deployment of Distributed Energy Resources (DERs) could eventually reshape the future distribution grid operation in numerous ways. Thus, it is necessary to introduce a framework to measure to what extent the power system operation will be changed by various parameters of DERs. This article proposed a modelling framework for an overview analysis on the correlation between DERs. Furthermore, to validate the framework, the authors described the reference models of different categories of DERs with their unique characteristics, comprising distributed generation, active demand and electric vehicles. Subsequently, quantitative analysis was made on the basis of the current and envisioned DER deployment scenarios proposed for Sweden. Simulations are performed in two typical distribution network models for four seasons. The simulation results show that in general the DER deployment brings in the possibilities to reduce the power losses and voltage drops by compensating power from the local generation and optimizing the local load profiles.

  3. Patterns of inequality: Dynamics of income distribution in USA and global energy consumption distribution

    NASA Astrophysics Data System (ADS)

    Banerjee, Anand; Yakovenko, Victor

    2010-03-01

    Applying the principle of entropy maximization, we argued that the distribution of money in a closed economic system should be exponential [1], see also recent review [2]. In this talk, we show that income distribution in USA is exponential for the majority of population (about 97%). However, the high-income tail follows a power law and is highly dynamical, i.e., out of equilibrium. The fraction of income going to the tail swelled to 20% of all income in 2000 and 2006 at the peaks of speculative bubbles followed by spectacular crashes. Next, we analyze the global distribution of energy consumption per capita among different countries. In the first approximation, it is reasonably well captured by the exponential function. Comparing the data for 1990 and 2005, we observe that the distribution is getting closer to the exponential, presumably as a result of globalization of the world economy.[4pt] [1] A. A. Dragulescu and V. M. Yakovenko, Eur. Phys. J. B 17, 723 (2000). [2] V. M. Yakovenko and J. B. Rosser, to appear in Rev. Mod. Phys. (2009), arXiv:0905.1518.

  4. Supernova 1972e in NGC 5253. [energy distribution and physical model

    NASA Technical Reports Server (NTRS)

    Kirshner, R. P.; Oke, J. B.

    1975-01-01

    Absolute energy distributions of the Type I supernova 1972e in NGC 5253 extending to about 700 days after maximum light have been obtained. A physical model of the expanding envelope, based on the identification of the feature at 6550 A with H-alpha is proposed. It consists of a differentially expanding atmosphere, with electron density ranging from 10 billion near maximum light to about 10 million 340 days later, illuminated by a photosphere with temperature in the range from 10,000 K to 7000 K. Under these conditions, the identifications of Ca II 8600-A, H, and K lines, the Na D lines, and the Mg I b lines forming P Cygni lines are quite plausible. More than 200 days after maximum, the spectrum is dominated by four features between 4200 and 5500 A. Three of these four features match the blended emissions from over 100 Fe II forbidden lines. If this identification is correct, the envelope requires about 0.01 solar mass of iron, which corresponds to an Fe/H ratio about 20 times higher than the cosmic abundance. Possible identifications of the fourth feature with the Mg I 4571-A line or permitted lines of Fe II are also discussed.

  5. Energy and angular distributions of hyperthermal-energy Li{sup +} scattered from Cu(001)

    SciTech Connect

    Behringer, E.R.; McLean, J.G.; Cooper, B.H.

    1996-03-01

    We have measured the in-plane energy and angular distributions of scattered Li{sup +} ions that result when Li{sup +} ion beams with incident energies {ital E}{sub {ital i}}=100 and 400 eV impinge on Cu(001) with an incident angle {theta}{sub {ital i}}=65{degree} and along the {l_angle}100{r_angle} azimuth. By comparing the energy and angular distributions with those generated by classical trajectory simulations, we extract information about the ion-surface interaction potential. A model ion-surface potential consisting of a sum of Hartree-Fock pair potentials and an attractive term produces good agreement with the measured distributions at both incident energies, while the universal potential of Ziegler, Biersack, and Littmarck does so only for {ital E}{sub {ital i}} = 400 eV. Analysis of the simulated distributions enables us to correlate different types of scattering events with features of the measured distributions (e.g., rainbows) and so obtain a detailed understanding of the scattering of Li{sup +}, which is more complex than has been previously observed for heavier alkali ions (e.g., Na{sup +} and K{sup +}). We find that the energy loss of the Li{sup +} ions can be mostly accounted for by momentum transfer to the surface atoms and that inelastic losses are small but significant for this system at these incident energies. We also find that the thermal vibrations of the surface atoms have dramatic effects on the simulated energy and angular distributions. {copyright} {ital 1996 The American Physical Society.}

  6. Planck/LFI measures of Planets Spectral Energy Distribution

    NASA Astrophysics Data System (ADS)

    Maris, Michele; Romelli, Erik; Gregorio, Anna; Zacchei, Andrea; Tomasi, Maurizio; Vassallo, Thomas; Sandri, Maura

    2015-08-01

    The spectral energy distribution at millimetric wavelengths of planets is an important benchmark to inter-calibrate different CMB experiments and a source of information on the atmospheric structure of planets. Planck/LFI observed Mars, Jupiter, Saturn, Uranus and Neptune from three to eight times during its mission. In particular, as a calibrator Jupiter allows accurate comparison due to its high S/N ratio. Since planets are moving objects, the measure must account for their proper motion as well as a number of second order effects. Here we present the results of accurate measurements of brightness temperature Tb of planets, and we compare them with WMAP.

  7. Adoption and supply of a distributed energy technology

    NASA Astrophysics Data System (ADS)

    Strachan, Neil Douglas

    2000-12-01

    Technical and economic developments in distributed generation (DG) represent an opportunity for a radically different energy market paradigm, and potentially significant cuts in global carbon emissions. This thesis investigates DG along two interrelated themes: (1) Early adoption and supply of the DG technology of internal combustion (IC) engine cogeneration. (2) Private and social cost implications of DG for private investors and within an energy system. IC engine cogeneration of both power and heat has been a remarkable success in the Netherlands with over 5,000 installations and 1,500MWe of installed capacity by 1997. However, the technology has struggled in the UK with an installed capacity of 110Mwe, fulfilling only 10% of its large estimated potential. An investment simulation model of DG investments in the UK and Netherlands was used, together with analysis of site level data on all DG adoptions from 1985 through 1997. In the UK over 60% of the early installations were sized too small (<140kWe) to be economically attractive (suppliers made their money with maintenance contracts). In the Netherlands, most facilities were sized well above the economic size threshold of 100kWe (lower due to reduced operating and grid connection costs). Institutional players were key in improved sizing of DG. Aided by energy market and CO2 reduction regulatory policy, Dutch distributions utilities played a proactive role in DG. This involved joint ventures with engine cogen suppliers and users, offering improved electricity buy-back tariffs and lower connection costs. This has allowed flexible operation of distributed generation, especially in electricity sales to the grid. Larger units can be sized for on-site heat requirements with electricity export providing revenue and aiding in management of energy networks. A comparison of internal and external costs of three distributed and three centralized generation technologies over a range of heat to power ratios (HPR) was made

  8. Terahertz absorption spectra and potential energy distribution of liquid crystals.

    PubMed

    Chen, Zezhang; Jiang, Yurong; Jiang, Lulu; Ma, Heng

    2016-01-15

    In this work, the terahertz (THz) absorption spectra of a set of nematic liquid crystals were studied using the density functional theories (DFT). An accurate assignment of the vibrational modes corresponding to absorption frequencies were performed using potential energy distribution (PED) in a frequency range of 0-3 THz. The impacts of different core structures on THz absorption spectra were discussed. The results indicate that scope of application must be considered in the LC-based THz device designing. This proposed work may give a useful suggestion on the design of novel liquid crystal material in THz wave. PMID:26476072

  9. Energy dependent pitch angle distributions of auroral primary electrons

    NASA Technical Reports Server (NTRS)

    Singh, N.

    1988-01-01

    Double-layer/parallel-electric field accelerations and the subsequent electron-beam plasma interactions involving Cerenkov and anomalous cyclotron resonances are considered. It is found that these phenomena yield pitch angle distributions as noted from rocket and satellite studies. Although the electron acceleration by weak parallel electric fields forming a runaway electron tail is limited to a critical parallel energy determined by the anomalous cyclotron resonance, such a limitation does not occur with acceleration by a localized parallel electric field such as that in a double layer.

  10. Absolute and relative dosimetry for ELIMED

    SciTech Connect

    Cirrone, G. A. P.; Schillaci, F.; Scuderi, V.; Cuttone, G.; Candiano, G.; Musumarra, A.; Pisciotta, P.; Romano, F.; Carpinelli, M.; Presti, D. Lo; Raffaele, L.; Tramontana, A.; Cirio, R.; Sacchi, R.; Monaco, V.; Marchetto, F.; Giordanengo, S.

    2013-07-26

    The definition of detectors, methods and procedures for the absolute and relative dosimetry of laser-driven proton beams is a crucial step toward the clinical use of this new kind of beams. Hence, one of the ELIMED task, will be the definition of procedures aiming to obtain an absolute dose measure at the end of the transport beamline with an accuracy as close as possible to the one required for clinical applications (i.e. of the order of 5% or less). Relative dosimetry procedures must be established, as well: they are necessary in order to determine and verify the beam dose distributions and to monitor the beam fluence and the energetic spectra during irradiations. Radiochromic films, CR39, Faraday Cup, Secondary Emission Monitor (SEM) and transmission ionization chamber will be considered, designed and studied in order to perform a fully dosimetric characterization of the ELIMED proton beam.

  11. Asteroid absolute magnitudes and slope parameters

    NASA Technical Reports Server (NTRS)

    Tedesco, Edward F.

    1991-01-01

    A new listing of absolute magnitudes (H) and slope parameters (G) has been created and published in the Minor Planet Circulars; this same listing will appear in the 1992 Ephemerides of Minor Planets. Unlike previous listings, the values of the current list were derived from fits of data at the V band. All observations were reduced in the same fashion using, where appropriate, a single basis default value of 0.15 for the slope parameter. Distances and phase angles were computed for each observation. The data for 113 asteroids was of sufficiently high quality to permit derivation of their H and G. These improved absolute magnitudes and slope parameters will be used to deduce the most reliable bias-corrected asteroid size-frequency distribution yet made.

  12. Calculating fusion neutron energy spectra from arbitrary reactant distributions

    NASA Astrophysics Data System (ADS)

    Eriksson, J.; Conroy, S.; Andersson Sundén, E.; Hellesen, C.

    2016-02-01

    The Directional Relativistic Spectrum Simulator (DRESS) code can perform Monte-Carlo calculations of reaction product spectra from arbitrary reactant distributions, using fully relativistic kinematics. The code is set up to calculate energy spectra from neutrons and alpha particles produced in the D(d, n)3He and T(d, n)4He fusion reactions, but any two-body reaction can be simulated by including the corresponding cross section. The code has been thoroughly tested. The kinematics calculations have been benchmarked against the kinematics module of the ROOT Data Analysis Framework. Calculated neutron energy spectra have been validated against tabulated fusion reactivities and against an exact analytical expression for the thermonuclear fusion neutron spectrum, with good agreement. The DRESS code will be used as the core of a detailed synthetic diagnostic framework for neutron measurements at the JET and MAST tokamaks.

  13. Energy distribution of proton microbeam transmitted through two flat plates

    NASA Astrophysics Data System (ADS)

    Nagy, G. U. L.; Rajta, I.; Bereczky, R. J.; Tőkési, K.

    2015-07-01

    The transmission of 1 MeV proton microbeam passing between two parallel flat plates was investigated. Three different materials were used in our experiments. As insulators we used Polytetrafluoroethylene and borosilicate glass plates and glass with gold layer on the surface as conductor. The surface of the plates was parallel to the beam axis and one of the plates was moved towards the beam. The energy distribution and the deflection of the transmitted beam were measured as the function of the sample distance relative to the beam. We found systematic differences between the behaviour of the metallic and insulator samples. The proton microbeam suffered significant deflection towards the sample surface due to the image acceleration when using conductor material. In case of the glass and Polytetrafluoroethylene plates the beam was deflected into the opposite direction, and the incident protons did not suffer significant energy loss, which is the consequence of the guiding effect.

  14. Long-distance distribution of genuine energy-time entanglement

    PubMed Central

    Cuevas, A.; Carvacho, G.; Saavedra, G.; Cariñe, J.; Nogueira, W.A.T.; Figueroa, M.; Cabello, A.; Mataloni, P.; Lima, G.; Xavier, G.B.

    2013-01-01

    Any practical realization of entanglement-based quantum communication must be intrinsically secure and able to span long distances avoiding the need of a straight line between the communicating parties. The violation of Bell’s inequality offers a method for the certification of quantum links without knowing the inner workings of the devices. Energy-time entanglement quantum communication satisfies all these requirements. However, currently there is a fundamental obstacle with the standard configuration adopted: an intrinsic geometrical loophole that can be exploited to break the security of the communication, in addition to other loopholes. Here we show the first experimental Bell violation with energy-time entanglement distributed over 1 km of optical fibres that is free of this geometrical loophole. This is achieved by adopting a new experimental design, and by using an actively stabilized fibre-based long interferometer. Our results represent an important step towards long-distance secure quantum communication in optical fibres. PMID:24287678

  15. Broad band spectral energy distribution studies of Fermi bright blazars

    NASA Astrophysics Data System (ADS)

    Monte, C.; Giommi, P.; Cavazzuti, E.; Gasparrini, D.; Rainò, S.; Fuhrmann, L.; Angelakis, E.; Villata, M.; Raiteri, C. M.; Perri, M.; Richards, J.

    2011-02-01

    The Fermi Gamma-ray Space Telescope was successfully launched on June 11, 2008 and has already opened a new era for gamma-ray astronomy. The Large Area Telescope (LAT), the main instrument on board Fermi, presents a significant improvement in sensitivity over its predecessor EGRET, due to its large field of view and effective area, combined with its excellent timing capabilities. The preliminary results of the Spectral Energy Distribution Analysis performed on a sample of bright blazars are presented. For this study, the data from the first three months of data collection of Fermi have been used. The analysis is extended down to radio, mm, near-IR, optical, UV and X-ray bands and up to TeV energies based on unprecedented sample of simultaneous multi-wavelength observations by GASP-WEBT.

  16. Advanced Communication and Control Solutions of Distributed Energy Resources (DER)

    SciTech Connect

    Asgeirsson, Haukur; Seguin, Richard; Sherding, Cameron; de Bruet, Andre, G.; Broadwater, Robert; Dilek, Murat

    2007-01-10

    This report covers work performed in Phase II of a two phase project whose objective was to demonstrate the aggregation of multiple Distributed Energy Resources (DERs) and to offer them into the energy market. The Phase I work (DE-FC36-03CH11161) created an integrated, but distributed, system and procedures to monitor and control multiple DERs from numerous manufacturers connected to the electric distribution system. Procedures were created which protect the distribution network and personnel that may be working on the network. Using the web as the communication medium for control and monitoring of the DERs, the integration of information and security was accomplished through the use of industry standard protocols such as secure SSL,VPN and ICCP. The primary objective of Phase II was to develop the procedures for marketing the power of the Phase I aggregated DERs in the energy market, increase the number of DER units, and implement the marketing procedures (interface with ISOs) for the DER generated power. The team partnered with the Midwest Independent System Operator (MISO), the local ISO, to address the energy market and demonstrate the economic dispatch of DERs in response to market signals. The selection of standards-based communication technologies offers the ability of the system to be deployed and integrated with other utilities’ resources. With the use of a data historian technology to facilitate the aggregation, the developed algorithms and procedures can be verified, audited, and modified. The team has demonstrated monitoring and control of multiple DERs as outlined in phase I report including procedures to perform these operations in a secure and safe manner. In Phase II, additional DER units were added. We also expanded on our phase I work to enhance communication security and to develop the market model of having DERs, both customer and utility owned, participate in the energy market. We are proposing a two-part DER energy market model--a utility

  17. On Energy Trading Decision Methods in Distributed Energy Management Systems with Multiple Customers

    NASA Astrophysics Data System (ADS)

    Miyamoto, Toshiyuki; Sugimoto, Yohei; Mori, Kazuyuki; Kitamura, Shoichi; Yamamoto, Takaya

    This paper addresses an operation and energy purchase planning problem under the CO2 emissions regulation for corporate entities. Considering energy trading, more efficient energy consumption may be possible. We have studied an agent-based planning system, called Distributed Energy Management Systems (DEMSs), which intends to reduce energy consumption. In the DEMSs, CO2 emissions regulation is imposed on each corporate entity, and electrical and thermal energy trading among the entities are allowed. We have proposed an energy trading decision method based on the Market Oriented Programming (MOP). In this paper, we propose trading decision methods for the group composed of several customers and several suppliers. Experimental results show effectiveness of the proposed method.

  18. Role for Distributed Energy Resources (DER) in the Digital Economy

    SciTech Connect

    Key, Thomas S

    2007-11-01

    A large, and growing, part of the Nation's economy either serves or depends upon the information technology industry. These high-tech or "digital" enterprises are characterized by a dependence on electronic devices, need for completely reliable power supply, and intolerance to any power quality problems. In some cases these enterprises are densely populated with electronic loads and have very high energy usage per square foot. Serving these enterprises presents both electric power and equipment cooling challenges. Traditional electric utilities are often hard-pressed to deliver power that meets the stringent requirements of digital customers, and the economic and social consequences of a service quality or reliability problem can be large. New energy delivery and control options must be developed to effectively serve a digital economy. This report explores how distributed energy resources, partnerships between utility and customer to share the responsibility for service quality, innovative facility designs, higher energy efficiencies and waste-heat utilization can be coupled to meet the needs of a growing digital economy.

  19. Measurement of Gamma Energy Distributions and Multiplicities Using STEFF

    NASA Astrophysics Data System (ADS)

    Murray, E.; Smith, A. G.; Pollitt, A. J.; Matarranz, J.; Tsekhanovich, I.; Soldner, T.; Koster, U.; Biswas, D. C.

    2014-05-01

    Prompt gamma-ray energy distributions and multiplicities released during thermally induced fission of 235U have been measured using STEFF (SpecTrometer for Exotic Fission Fragments). Thermal neutrons are provided by the high-flux reactor at the ILL, Grenoble. STEFF is a unique 2E2v device that uses a coincidence timing method to measure the emission of prompt gamma rays as a function of the fragment mass and energy. Following scission, the fission fragments contain excitation energy that is released via prompt neutron and gamma-ray emission as the fragment decays to the ground state. STEFF contains an array of 11 NaI detectors surrounding the uranium target providing a 6.8% photopeak detection efficiency for gamma rays released within 1 ns of the scission time. STEFF also consists of 7 NE213 detectors, which detect the emission of prompt neutrons, the release of which is associated with reduction of fragment energy and, to a lesser extent, fragment spin. This experiment acts as a direct response to the NEA high priority demand which requires more accurate knowledge of heating caused by gamma emission in the next generation of nuclear reactors.

  20. Low energy ion distribution measurements in Madison Symmetric Torus plasmas

    SciTech Connect

    Titus, J. B. Mezonlin, E. D.; Johnson, J. A.

    2014-06-15

    Charge-exchange neutrals contain information about the contents of a plasma and can be detected as they escape confinement. The Florida A and M University compact neutral particle analyzer (CNPA), used to measure the contents of neutral particle flux, has been reconfigured, calibrated, and installed on the Madison Symmetric Torus (MST) for high temperature deuterium plasmas. The energy range of the CNPA has been extended to cover 0.34–5.2 keV through an upgrade of the 25 detection channels. The CNPA has been used on all types of MST plasmas at a rate of 20 kHz throughout the entire discharge (∼70 ms). Plasma parameter scans show that the ion distribution is most dependent on the plasma current. Magnetic reconnection events throughout these scans produce stronger poloidal electric fields, stronger global magnetic modes, and larger changes in magnetic energy all of which heavily influence the non-Maxwellian part of the ion distribution (the fast ion tail)

  1. SPHERICALLY SYMMETRIC STELLAR CLUSTERS WITH ANISOTROPY AND CUTOFF ENERGY IN MOMENTUM DISTRIBUTION. I. THE NEWTONIAN REGIME

    SciTech Connect

    Bisnovatyi-Kogan, Gennady S.

    2009-09-20

    We construct numerical models of spherically symmetric Newtonian stellar clusters with anisotropic distribution functions. These models generalize solutions obtained earlier for isotropic Maxwellian distribution functions with an energy cutoff and take into account distributions with different levels of anisotropy.

  2. The angular and energy distribution of the primary electron beam.

    PubMed

    Keall, P J; Hoban, P W

    1994-09-01

    The angular distribution for electron beams produced by the Siemens KD-2 linear accelerator has been found by simulating electron transport through the scattering foils and air using two methods: Fermi-Eyges multiple Coulomb scattering calculations, and EGS4 Monte Carlo simulations. Fermi-Eyges theory gives solutions where both the angular and spatial fluence distributions are Gaussian, with the angular standard deviation being invariant with off-axis distance. The EGS4 results show slightly non-Gaussian angular and lateral distributions as a result of the use of Moliére theory rather than Fermi-Eyges multiple scattering theory, as well as the simulation of discrete bremsstrahlung and Møller interactions. However, the results from both methods are very similar. The angular standard deviations obtained by these methods agree very closely with those found experimentally. The similar shape of the Monte Carlo and Fermi-Eyges results indicate that a Gaussian approximation to the incident angular distribution will be adequate for use in treatment planning algorithms. Furthermore, the angular standard deviation may be determined using Fermi-Eyges theory as an alternative to experimental methods. Both Monte Carlo simulations, and Fermi-Eyges theory predict that the mean electron angle is proportional to off axis distance for all useful field sizes. For a 15 MeV electron beam, an effective source position of 99 cm and 98 cm from the nominal 100 SSD plane was obtained from Fermi-Eyges and Monte Carlo results respectively for a 15 MeV beam. The effective source position found experimentally for this energy was 98 cm.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7980200

  3. From Hubble's NGSL to Absolute Fluxes

    NASA Technical Reports Server (NTRS)

    Heap, Sara R.; Lindler, Don

    2012-01-01

    Hubble's Next Generation Spectral Library (NGSL) consists of R-l000 spectra of 374 stars of assorted temperature, gravity, and metallicity. Each spectrum covers the wavelength range, 0.18-1.00 microns. The library can be viewed and/or downloaded from the website, http://archive.stsci.edu/prepds/stisngsll. Stars in the NGSL are now being used as absolute flux standards at ground-based observatories. However, the uncertainty in the absolute flux is about 2%, which does not meet the requirements of dark-energy surveys. We are therefore developing an observing procedure that should yield fluxes with uncertainties less than 1 % and will take part in an HST proposal to observe up to 15 stars using this new procedure.

  4. Product energy distributions and energy partitioning in O atom reactions on surfaces

    NASA Technical Reports Server (NTRS)

    Halpern, Bret; Kori, Moris

    1987-01-01

    Surface reactions involving O atoms are likely to be highly exoergic, with different consequences if energy is channeled mostly to product molecules or surface modes. Thus the surface may become a source of excited species which can react elsewhere, or a sink for localized heat deposition which may disrupt the surface. The vibrational energy distribution of the product molecule contains strong clues about the flow of released energy. Two instructive examples of energy partitioning at surfaces are the Pt catalyzed oxidations: (1) C(ads) + O(ads) yields CO* (T is greater than 1000 K); and (2) CO(ads) + O(gas) yields CO2* (T is approx. 300 K). The infrared emission spectra of the excited product molecules were recorded and the vibrational population distributions were determined. In reaction 1, energy appeared to be statistically partitioned between the product CO and several Pt atoms. In reaction 2, partitioning was non-statistical; the CO2 asymmetric stretch distribution was inverted. In gas reactions these results would indicate a long lived and short lived activated complex. The requirement that Pt be heated in O atoms to promote reaction of atomic O and CO at room temperature is specifically addressed. Finally, the fraction of released energy that is deposited in the catalyst is estimated.

  5. Measurement of the Absolute Elastic and Inelastic Differential Neutron Cross Sections for 23Na Between 2 and 4 MeV

    NASA Astrophysics Data System (ADS)

    Kumar, A.; Chakraborty, A.; Crider, B. P.; McEllistrem, M. T.; Peters, E. E.; Prados-Estévez, F. M.; Yates, S. W.; Hicks, S. F.; Kersting, L. J.; Luke, C. J.; McDonough, P. J.; Sigillito, A. J.; Vanhoy, J. R.

    2013-03-01

    Elastic and inelastic neutron scattering angular distributions have been measured from 23Na for incident neutron energies between 2 and 4 MeV at the University of Kentucky using neutron time-of-flight techniques. The cross sections obtained are important for applications in nuclear reactor development and other areas, and they are an energy region in which existing data are very sparse. Absolute cross sections were obtained by normalizing Na angular distributions to the well-known np cross sections.

  6. 77 FR 10997 - Energy Conservation Program: Energy Conservation Standards for Distribution Transformers; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-24

    ... distribution transformers (72 FR 58190). The Energy Policy Act of 2005 (EPACT 2005), Public Law 109-25, amended... transformers (77 FR 7282). Need for Correction As published, values in certain tables of the proposed rule are... February 10 NOPR. Corrections In proposed rule FR Doc. 2012-2642 appearing on page 7282 in the issue...

  7. Thylakoid protein phosphorylation: Regulation of light energy distribution in photosynthesis

    SciTech Connect

    Coughlan, S.J.

    1990-01-01

    It has become apparent that green plants possess the ability to adapt to changes in the spectral quality of ambient light. This phenomenon, state transitions, involves a reversible distribution of light energy between the two photosystems in response to changes in the excitation state of photosystems 1 and 2. Thus, the quantum efficiency of photosynthetic electron transport is maintained under different illumination conditions, and damage caused by excessive energetic input of light (photoinhibition) is prevented. This model comprises a phosphorylation/dephosphorylation cycle of three major components: substrates, the protein kinase(s) and protein phosphatase(s) responsible for the specific phosphorylation and dephosphorylation of these of substrates, and the control mechanisms whereby the protein kinase(s) is activated/deactivated in response to redox and /or conformational changes in the thylakoid. This report considers the three components in some detail.

  8. A bolometer array for the SPEctral Energy Distribution (SPEED) Camera

    NASA Astrophysics Data System (ADS)

    Silverberg, Robert F.; Campano, Barbara; Chen, Tina C.; Cheng, Edward; Cottingham, David A.; Crawford, Thomas M.; Downes, Tom; Finkbeiner, Fred M.; Fixsen, Dale J.; Logan, Dan; Meyer, Stephan S.; Perera, Thushara; Sharp, Elmer H.; Wilson, Grant W.

    2004-10-01

    The SPEED camera is being developed to study the spectral energy distributions of high redshift galaxies, Sunyaev-Zel'dovich effect in X-ray clusters and other cold objects in the universe. Its initial runs will be done on the 10 m Heinrich Hertz Submillimeter Telescope (HHSMT), with later runs using the Large Millimeter Telescope (LMT). SPEED requires a 2x2 pixel cryogenic detector array of Frequency Selective Bolometers (FSB). Each of the pixels will have four frequency bands in the ~150-350 GHz range. Here we describe the development of the detector array of these high efficiency FSBs. The FSB design provides the multi-pixel multi-spectral band capability required for SPEED in a compact, light weight, stackable array. The SPEED FSB bolometers will use proximity effect superconducting transition edge sensors (TES) as their temperature-sensing element permitting significantly higher levels of electronic multiplexing in future applications where larger numbers of detectors may be required.

  9. Vibrational Energy Distribution Analysis (VEDA): Scopes and limitations

    NASA Astrophysics Data System (ADS)

    Jamróz, Michał H.

    2013-10-01

    The principle of operations of the VEDA program written by the author for Potential Energy Distribution (PED) analysis of theoretical vibrational spectra is described. Nowadays, the PED analysis is indispensible tool in serious analysis of the vibrational spectra. To perform the PED analysis it is necessary to define 3N-6 linearly independent local mode coordinates. Already for 20-atomic molecules it is a difficult task. The VEDA program reads the input data automatically from the Gaussian program output files. Then, VEDA automatically proposes an introductory set of local mode coordinates. Next, the more adequate coordinates are proposed by the program and optimized to obtain maximal elements of each column (internal coordinate) of the PED matrix (the EPM parameter). The possibility for an automatic optimization of PED contributions is a unique feature of the VEDA program absent in any other programs performing PED analysis.

  10. Optimal smoothing of site-energy distributions from adsorption isotherms

    SciTech Connect

    Brown, L.F.; Travis, B.J.

    1983-01-01

    The equation for the adsorption isotherm on a heterogeneous surface is a Fredholm integral equation. In solving it for the site-energy distribution (SED), some sort of smoothing must be carried out. The optimal amount of smoothing will give the most information that is possible without introducing nonexistent structure into the SED. Recently, Butler, Reeds, and Dawson proposed a criterion (the BRD criterion) for choosing the optimal smoothing parameter when using regularization to solve Fredholm equations. The BRD criterion is tested for its suitability in obtaining optimal SED's. This criterion is found to be too conservative. While using it never introduces nonexistent structure into the SED, significant information is often lost. At present, no simple criterion for choosing the optimal smoothing parameter exists, and a modeling approach is recommended.

  11. Evaluation Framework and Tools for Distributed Energy Resources

    SciTech Connect

    Gumerman, Etan Z.; Bharvirkar, Ranjit R.; LaCommare, Kristina Hamachi; Marnay , Chris

    2003-02-01

    The Energy Information Administration's (EIA) 2002 Annual Energy Outlook (AEO) forecast anticipates the need for 375 MW of new generating capacity (or about one new power plant) per week for the next 20 years, most of which is forecast to be fueled by natural gas. The Distributed Energy and Electric Reliability Program (DEER) of the Department of Energy (DOE), has set a national goal for DER to capture 20 percent of new electric generation capacity additions by 2020 (Office of Energy Efficiency and Renewable Energy 2000). Cumulatively, this amounts to about 40 GW of DER capacity additions from 2000-2020. Figure ES-1 below compares the EIA forecast and DEER's assumed goal for new DER by 2020 while applying the same definition of DER to both. This figure illustrates that the EIA forecast is consistent with the overall DEER DER goal. For the purposes of this study, Berkeley Lab needed a target level of small-scale DER penetration upon which to hinge consideration of benefits and costs. Because the AEO2002 forecasted only 3.1 GW of cumulative additions from small-scale DER in the residential and commercial sectors, another approach was needed to estimate the small-scale DER target. The focus here is on small-scale DER technologies under 500 kW. The technology size limit is somewhat arbitrary, but the key results of interest are marginal additional costs and benefits around an assumed level of penetration that existing programs might achieve. Berkeley Lab assumes that small-scale DER has the same growth potential as large scale DER in AEO2002, about 38 GW. This assumption makes the small-scale goal equivalent to 380,000 DER units of average size 100 kW. This report lays out a framework whereby the consequences of meeting this goal might be estimated and tallied up. The framework is built around a list of major benefits and a set of tools that might be applied to estimate them. This study lists some of the major effects of an emerging paradigm shift away from central

  12. Spectrophotometry of Wolf-Rayet stars. I - Continuum energy distributions

    NASA Technical Reports Server (NTRS)

    Morris, Patrick W.; Brownsberger, Kenneth R.; Conti, Peter S.; Massey, Philip; Vacca, William D.

    1993-01-01

    All available low-resolution IUE spectra are assembled for Galactic, LMC, and SMC W-R stars and are merged with ground-based optical and NIR spectra in order to collate in a systematic fashion the shapes of these energy distributions over the wavelength range 0.1-1 micron. They can be consistently fitted by a power law of the form F(lambda) is approximately equal to lambda exp -alpha over the range 1500-9000 A to derive color excesses E(B-V) and spectral indices by removing the 2175-A interstellar absorption feature. The WN star color excesses derived are found to be in good agreement with those of Schmutz and Vacca (1991) and Koesterke et al. (1991). Significant heterogeneity in spectral index values was generally seen with any given subtype, but the groups consisting of the combined set of Galactic and LMC W-R stars, the separate WN and WC sequences, and the Galactic and LMC W-R stars all showed a striking and consistent Gaussian-like frequency distribution of values.

  13. The Far-Infrared Spectral Energy Distributions of Quasars

    NASA Technical Reports Server (NTRS)

    Wilkes, Belinda J.; West, Donald K. (Technical Monitor)

    2001-01-01

    The origin of the infrared emission in Active Galactic Nuclei (AGN), whose strength is comparable to the optical/ultraviolet (OUV) emission, is generally thought to be a combination of thermal emission from dust and non-thermal, synchrotron emission. Although data are sparse, particularly in the far-infrared, the broad wavelength range of this emission suggests a wide range of temperatures and a combination of AGN and starburst heating mechanisms. The strength of the non-thermal emission is expected to be related to the radio emission. While this scenario is well-established, basic questions, such as the spatial and temperature distribution of the dust, the relative importance of AGN and starburst heating, and the significance of the non-thermal contribution remain largely undetermined. The wide wavelength range of the Infrared Space Observatory (ISO) combined with its arcmin spatial resolution and increased sensitivity facilitated the observation of a larger subset of the AGN population than previously covered, allowing these questions to be investigated in more detail. This paper will review the spectral energy distributions (SED) of AGN with particular emphasis on the infrared emission and on ISO's contributions to our knowledge. Preliminary results from ISO observations of X-ray selected and high-redshift AGN will be described.

  14. The Spectral Energy Distributions of Interacting Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Liss, Sandra; Johnson, Kelsey E.; Stierwalt, Sabrina; Kallivayalil, Nitya; Besla, Gurtina; Patton, David R.; Privon, George C.

    2016-01-01

    We present spectral energy distributions (SEDs) for the TiNy Titans survey, the first systematic study of interactions between dwarf galaxies. Galaxy interactions are known to be of fundamental importance to the evolution of massive galaxies -- they have been observed to impact morphology, star formation rates, and ISM composition. Such interactions also occur frequently between low mass dwarf galaxies, but this process is poorly understood and largely overlooked in comparison. Although the majority of mergers at all redshifts are expected to take place between low mass galaxies, until now there have not been comparable systematic studies of dwarf galaxy interactions, leaving open the question of whether interactions between low mass galaxies can strongly affect their own evolution. The TiNy Titans survey, a complete sample of isolated dwarf galaxy pairs selected from the Sloan Digital Sky Survey (SDSS), is specifically designed to address this gap in our understanding of galaxy evolution. The SEDs presented here, generated from archival WISE, SDSS, and GALEX photometric data, allow us to characterize the typical interacting dwarf galaxy, as well as quantify the deviations from this average distribution. We also present trends in the SEDs as a function of projected radial separation, a proxy for interaction stage.

  15. A modal approach to modeling spatially distributed vibration energy dissipation.

    SciTech Connect

    Segalman, Daniel Joseph

    2010-08-01

    The nonlinear behavior of mechanical joints is a confounding element in modeling the dynamic response of structures. Though there has been some progress in recent years in modeling individual joints, modeling the full structure with myriad frictional interfaces has remained an obstinate challenge. A strategy is suggested for structural dynamics modeling that can account for the combined effect of interface friction distributed spatially about the structure. This approach accommodates the following observations: (1) At small to modest amplitudes, the nonlinearity of jointed structures is manifest primarily in the energy dissipation - visible as vibration damping; (2) Correspondingly, measured vibration modes do not change significantly with amplitude; and (3) Significant coupling among the modes does not appear to result at modest amplitudes. The mathematical approach presented here postulates the preservation of linear modes and invests all the nonlinearity in the evolution of the modal coordinates. The constitutive form selected is one that works well in modeling spatially discrete joints. When compared against a mathematical truth model, the distributed dissipation approximation performs well.

  16. Data intensive high energy physics analysis in a distributed cloud

    NASA Astrophysics Data System (ADS)

    Charbonneau, A.; Agarwal, A.; Anderson, M.; Armstrong, P.; Fransham, K.; Gable, I.; Harris, D.; Impey, R.; Leavett-Brown, C.; Paterson, M.; Podaima, W.; Sobie, R. J.; Vliet, M.

    2012-02-01

    We show that distributed Infrastructure-as-a-Service (IaaS) compute clouds can be effectively used for the analysis of high energy physics data. We have designed a distributed cloud system that works with any application using large input data sets requiring a high throughput computing environment. The system uses IaaS-enabled science and commercial clusters in Canada and the United States. We describe the process in which a user prepares an analysis virtual machine (VM) and submits batch jobs to a central scheduler. The system boots the user-specific VM on one of the IaaS clouds, runs the jobs and returns the output to the user. The user application accesses a central database for calibration data during the execution of the application. Similarly, the data is located in a central location and streamed by the running application. The system can easily run one hundred simultaneous jobs in an efficient manner and should scale to many hundreds and possibly thousands of user jobs.

  17. SATMC: Spectral energy distribution Analysis Through Markov Chains

    NASA Astrophysics Data System (ADS)

    Johnson, S. P.; Wilson, G. W.; Tang, Y.; Scott, K. S.

    2013-12-01

    We present the general purpose spectral energy distribution (SED) fitting tool SED Analysis Through Markov Chains (SATMC). Utilizing Monte Carlo Markov Chain (MCMC) algorithms, SATMC fits an observed SED to SED templates or models of the user's choice to infer intrinsic parameters, generate confidence levels and produce the posterior parameter distribution. Here, we describe the key features of SATMC from the underlying MCMC engine to specific features for handling SED fitting. We detail several test cases of SATMC, comparing results obtained from traditional least-squares methods, which highlight its accuracy, robustness and wide range of possible applications. We also present a sample of submillimetre galaxies (SMGs) that have been fitted using the SED synthesis routine GRASIL as input. In general, these SMGs are shown to occupy a large volume of parameter space, particularly in regards to their star formation rates which range from ˜30 to 3000 M⊙ yr-1 and stellar masses which range from ˜1010 to 1012 M⊙. Taking advantage of the Bayesian formalism inherent to SATMC, we also show how the fitting results may change under different parametrizations (i.e. different initial mass functions) and through additional or improved photometry, the latter being crucial to the study of high-redshift galaxies.

  18. Distributed generation capabilities of the national energy modeling system

    SciTech Connect

    LaCommare, Kristina Hamachi; Edwards, Jennifer L.; Marnay, Chris

    2003-01-01

    This report describes Berkeley Lab's exploration of how the National Energy Modeling System (NEMS) models distributed generation (DG) and presents possible approaches for improving how DG is modeled. The on-site electric generation capability has been available since the AEO2000 version of NEMS. Berkeley Lab has previously completed research on distributed energy resources (DER) adoption at individual sites and has developed a DER Customer Adoption Model called DER-CAM. Given interest in this area, Berkeley Lab set out to understand how NEMS models small-scale on-site generation to assess how adequately DG is treated in NEMS, and to propose improvements or alternatives. The goal is to determine how well NEMS models the factors influencing DG adoption and to consider alternatives to the current approach. Most small-scale DG adoption takes place in the residential and commercial modules of NEMS. Investment in DG ultimately offsets purchases of electricity, which also eliminates the losses associated with transmission and distribution (T&D). If the DG technology that is chosen is photovoltaics (PV), NEMS assumes renewable energy consumption replaces the energy input to electric generators. If the DG technology is fuel consuming, consumption of fuel in the electric utility sector is replaced by residential or commercial fuel consumption. The waste heat generated from thermal technologies can be used to offset the water heating and space heating energy uses, but there is no thermally activated cooling capability. This study consists of a review of model documentation and a paper by EIA staff, a series of sensitivity runs performed by Berkeley Lab that exercise selected DG parameters in the AEO2002 version of NEMS, and a scoping effort of possible enhancements and alternatives to NEMS current DG capabilities. In general, the treatment of DG in NEMS is rudimentary. The penetration of DG is determined by an economic cash-flow analysis that determines adoption based on the

  19. Distributed Energy Alternative to Electrical Distribution Grid Expansion in Consolidated Edison Service Territory

    SciTech Connect

    Kingston, Tim; Kelly, John

    2008-08-01

    The nation's power grid, specifically the New York region, faces burgeoning energy demand and suffers from congested corridors and aging equipment that cost New York consumers millions of dollars. Compounding the problem is high-density buildup in urban areas that limits available space to expand grid capacity. Coincidently, these urban areas are precisely where additional power is required. DER in this study refers to combined heat and power (CHP) technology, which simultaneously generates heat and electricity at or near the point where the energy will be consumed. There are multiple CHP options available that, combined with a portfolio of other building energy efficiency (EE) strategies, can help achieve a more efficient supply-demand balance than what the grid can currently provide. As an alternative to expanding grid capacity, CHP and EE strategies can be deployed in a flexible manner at virtually any point on the grid to relieve load. What's more, utilities and customers can install them in a variety of potentially profitable applications that are more environmentally friendly. Under the auspices of the New York State Energy Research and Development Authority (NYSERDA) and the Oak Ridge National Laboratory representing the Office of Electricity of the U.S. Department of Energy, Gas Technology Institute (GTI) conducted this study in cooperation with Consolidated Edison to help broaden the market penetration of EE and DER. This study provides realistic load models and identifies the impacts that EE and DER can have on the electrical distribution grid; specifically within the current economic and regulatory environment of a high load growth area of New York City called Hudson Yards in Midtown Manhattan. These models can be used to guide new policies that improve market penetration of appropriate CHP and EE technologies in new buildings. The following load modeling scenarios were investigated: (1) Baseline: All buildings are built per the Energy Conservation

  20. A graphite calorimeter for absolute measurements of absorbed dose to water: application in medium-energy x-ray filtered beams

    NASA Astrophysics Data System (ADS)

    Pinto, M.; Pimpinella, M.; Quini, M.; D'Arienzo, M.; Astefanoaei, I.; Loreti, S.; Guerra, A. S.

    2016-02-01

    The Italian National Institute of Ionizing Radiation Metrology (ENEA-INMRI) has designed and built a graphite calorimeter that, in a water phantom, has allowed the determination of the absorbed dose to water in medium-energy x-rays with generating voltages from 180 to 250 kV. The new standard is a miniaturized three-bodies calorimeter, with a disc-shaped core of 21 mm diameter and 2 mm thickness weighing 1.134 g, sealed in a PMMA waterproof envelope with air-evacuated gaps. The measured absorbed dose to graphite is converted into absorbed dose to water by means of an energy-dependent conversion factor obtained from Monte Carlo simulations. Heat-transfer correction factors were determined by FEM calculations. At a source-to-detector distance of 100 cm, a depth in water of 2 g cm-2, and at a dose rate of about 0.15 Gy min-1, results of calorimetric measurements of absorbed dose to water, D w, were compared to experimental determinations, D wK, obtained via an ionization chamber calibrated in terms of air kerma, according to established dosimetry protocols. The combined standard uncertainty of D w and D wK were estimated as 1.9% and 1.7%, respectively. The two absorbed dose to water determinations were in agreement within 1%, well below the stated measurement uncertainties. Advancements are in progress to extend the measurement capability of the new in-water-phantom graphite calorimeter to other filtered medium-energy x-ray qualities and to reduce the D w uncertainty to around 1%. The new calorimeter represents the first implementation of in-water-phantom graphite calorimetry in the kilovoltage range and, allowing independent determinations of D w, it will contribute to establish a robust system of absorbed dose to water primary standards for medium-energy x-ray beams.

  1. Optical Diagnostics of Electron Energy Distributions in Low Temperature Plasmas

    NASA Astrophysics Data System (ADS)

    Wendt, Amy

    2011-05-01

    Passive, non-invasive optical emission measurements provide a means of probing important plasma parameters without introducing contaminants into plasma systems. We investigate the electron energy distribution function (EEDF) in argon containing inductively-coupled plasmas due to dominant role in rates of gas-phase reactions for processing plasmas. EEDFs are determined using measurements of 3p5 4 p --> 3p5 4 s emissions in the 650-1150 nm wavelength range and measured metastable and resonant level concentrations, in conjunction with a radiation model that includes contributions from often neglected but critical processes such as radiation trapping and electron-impact excitation from metastable and resonant levels. Measurements over a wide range of operating conditions (pressure, RF power, Ar/Ne/N2 gas mixtures) show a depletion of the EEDF relative to the Maxwell- Boltzmann form at higher electron energy, in good agreement with measurements made with Langmuir probes and predictions of a global discharge model. This result is consistent with predictions of electron kinetics and can be explained in terms of reduced life times for energetic electrons due to wall losses and inelastic collisions. This example highlights the potential utility of this method as a tool for probing kinetics of many types of low-temperature plasma systems, which are typically characterized by non-Maxwellian EEDFs. This work was supported by the Wisconsin Alumni Research Foundation (WARF) and by NSF Grant CBET 0714600.

  2. Ion energy distribution functions in a supersonic plasma jet

    NASA Astrophysics Data System (ADS)

    Caldirola, S.; Roman, H. E.; Riccardi, C.

    2014-11-01

    Starting from experimental measurements of ion energy distribution functions (IEDFs) in a low pressure supersonic plasma jet, we propose a model to simulate them numerically from first principles calculations. Experimentally we acquired IEDFs with a quadrupole mass spectrometer (QMS) collecting the argon ions produced from a inductively coupled plasma (ICP) and driven into a supersonic free gas expansion. From the discussion of these results and the physics of our system we developed a simulation code. Integrating the equations of motion the code evolves the trajectory of a single ion across the jet. Ar+- Ar collisions are modelled with a 12-4 Lennard-Jones potential which considers induced dipole interactions. IEDFs were simulated at different positions along the jet and compared with the experimental data showing good agreement. We have also implemented a charge transfer mechanism in which the ion releases its charge to a neutral atom which can take place at sufficiently close distances and is a function of the impact energy.

  3. The Spectral Energy Distribution of HH 100 IRS

    NASA Technical Reports Server (NTRS)

    Siebenmorgen, Ralf

    1996-01-01

    Recent progress in the modeling of the radiative transfer in star forming regions has lead to improved dusty envelope models. Such models can now explain in great detail the observed infrared spectrum. The success of such models suggests that input parameters correspond to the true physical situation of the environment of the young stellar object. However, so far only minor attention has been given to models which include the spectroscopic signature of ice bands. Such models are applied to the Herbig-Haro energy source HH100 IRS. Calculations have been performed to interpret the spectral energy distribution as a function of dust parameters such as the grain size, the ice volume fraction, and the 'fluffiness' of the particles. The infrared spectrum together with the strength of the water ice band of HH 100 IRS is successfully reproduced if an upper limit of the grain size below 1 micron is used. Comet-like grains, with sizes above 1 micron, result in a poor fit of the observations.

  4. Equilibrium distribution of the wave energy in a carbyne chain

    NASA Astrophysics Data System (ADS)

    Kovriguine, D. A.; Nikitenkova, S. P.

    2016-03-01

    The steady-state energy distribution of thermal vibrations at a given ambient temperature has been investigated based on a simple mathematical model that takes into account central and noncentral interactions between carbon atoms in a one-dimensional carbyne chain. The investigation has been performed using standard asymptotic methods of nonlinear dynamics in terms of the classical mechanics. In the first-order nonlinear approximation, there have been revealed resonant wave triads that are formed at a typical nonlinearity of the system under phase matching conditions. Each resonant triad consists of one longitudinal and two transverse vibration modes. In the general case, the chain is characterized by a superposition of similar resonant triplets of different spectral scales. It has been found that the energy equipartition of nonlinear stationary waves in the carbyne chain at a given temperature completely obeys the standard Rayleigh-Jeans law due to the proportional amplitude dispersion. The possibility of spontaneous formation of three-frequency envelope solitons in carbyne has been demonstrated. Heat in the form of such solitons can propagate in a chain of carbon atoms without diffusion, like localized waves.

  5. Absolute dosimetry for extreme-ultraviolet lithography

    NASA Astrophysics Data System (ADS)

    Berger, Kurt W.; Campiotti, Richard H.

    2000-06-01

    The accurate measurement of an exposure dose reaching the wafer on an extreme ultraviolet (EUV) lithographic system has been a technical challenge directly applicable to the evaluation of candidate EUV resist materials and calculating lithography system throughputs. We have developed a dose monitoring sensor system that can directly measure EUV intensities at the wafer plane of a prototype EUV lithographic system. This sensor system, located on the wafer stage adjacent to the electrostatic chuck used to grip wafers, operates by translating the sensor into the aerial image, typically illuminating an 'open' (unpatterned) area on the reticle. The absolute signal strength can be related to energy density at the wafer, and thus used to determine resist sensitivity, and the signal as a function of position can be used to determine illumination uniformity at the wafer plane. Spectral filtering to enhance the detection of 13.4 nm radiation was incorporated into the sensor. Other critical design parameters include the packaging and amplification technologies required to place this device into the space and vacuum constraints of a EUV lithography environment. We describe two approaches used to determine the absolute calibration of this sensor. The first conventional approach requires separate characterization of each element of the sensor. A second novel approach uses x-ray emission from a mildly radioactive iron source to calibrate the absolute response of the entire sensor system (detector and electronics) in a single measurement.

  6. Absolute transition probabilities of phosphorus.

    NASA Technical Reports Server (NTRS)

    Miller, M. H.; Roig, R. A.; Bengtson, R. D.

    1971-01-01

    Use of a gas-driven shock tube to measure the absolute strengths of 21 P I lines and 126 P II lines (from 3300 to 6900 A). Accuracy for prominent, isolated neutral and ionic lines is estimated to be 28 to 40% and 18 to 30%, respectively. The data and the corresponding theoretical predictions are examined for conformity with the sum rules.-

  7. A graphite calorimeter for absolute measurements of absorbed dose to water: application in medium-energy x-ray filtered beams.

    PubMed

    Pinto, M; Pimpinella, M; Quini, M; D'Arienzo, M; Astefanoaei, I; Loreti, S; Guerra, A S

    2016-02-21

    The Italian National Institute of Ionizing Radiation Metrology (ENEA-INMRI) has designed and built a graphite calorimeter that, in a water phantom, has allowed the determination of the absorbed dose to water in medium-energy x-rays with generating voltages from 180 to 250 kV. The new standard is a miniaturized three-bodies calorimeter, with a disc-shaped core of 21 mm diameter and 2 mm thickness weighing 1.134 g, sealed in a PMMA waterproof envelope with air-evacuated gaps. The measured absorbed dose to graphite is converted into absorbed dose to water by means of an energy-dependent conversion factor obtained from Monte Carlo simulations. Heat-transfer correction factors were determined by FEM calculations. At a source-to-detector distance of 100 cm, a depth in water of 2 g cm(-2), and at a dose rate of about 0.15 Gy min(-1), results of calorimetric measurements of absorbed dose to water, D(w), were compared to experimental determinations, D wK, obtained via an ionization chamber calibrated in terms of air kerma, according to established dosimetry protocols. The combined standard uncertainty of D(w) and D(wK) were estimated as 1.9% and 1.7%, respectively. The two absorbed dose to water determinations were in agreement within 1%, well below the stated measurement uncertainties. Advancements are in progress to extend the measurement capability of the new in-water-phantom graphite calorimeter to other filtered medium-energy x-ray qualities and to reduce the D(w) uncertainty to around 1%. The new calorimeter represents the first implementation of in-water-phantom graphite calorimetry in the kilovoltage range and, allowing independent determinations of D(w), it will contribute to establish a robust system of absorbed dose to water primary standards for medium-energy x-ray beams. PMID:26841127

  8. Direct Energy Exchange Enhancement in Distributed Injection Light Gas Launchers

    SciTech Connect

    Alger, T W; Finucane, R G; Hall, J P; Penetrante, B M; Uphaus, T M

    2000-04-06

    initially contained in the reservoir. This results deserves emphasis: whereas conventional guns apply a few percent of the reservoir pressure to a fast moving projectile, our design is paradoxically capable of applying nearly double the contained pressure. We later confirmed this experimental result analytically and related it to a type of direct energy exchange between unsteady fluid flows. This physical approach was the basis for the German V-1 ''buzz bomb'' of World War II; it has been applied to a limited number of commercial applications. (This work should not be confused with the German WWII distributed injection missile launchers.) Direct fluid-energy exchange has not previously been applied to any gas-launcher technology. As a result of these discoveries, we estimate that a practical, 15 km/s, high-velocity launcher could be built using our direct-energy-exchange, distributed-injection approach. However, the radical nature of the results, the lack of confirming or allied work being carried out anywhere else, and the fact that it would take extensive time and resources to demonstrate targeted performance precluded further development. We plan to submit the results to a refereed journal to ensure that the work will not be lost to the launcher community.

  9. The Spectral Energy Distribution of Fermi Bright Blazars

    NASA Technical Reports Server (NTRS)

    Abdo, A. A.; Ackermann, M.; Agudo, I.; Ajello, M.; Aller, H. D.; Aller, M. F.; Angelakis, E.; Arkharov, A. A.; Axelsson, M.; Bach, U.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bechtol, K.; Bellazzini, R.; Benitiez, E.; Berdyugin, A.; Gehrels, N.; Harding, A. K.; Hays, E.; Marshall, F.; Scargle, J. D.; Thompson, D. J.

    2010-01-01

    We have conducted a detailed investigation of the broadband spectral properties of the gamma-ray selected blazars of the Fermi LAT Bright AGN Sample (LBAS). By combining our accurately estimated Fermi gamma-ray spectra with Swift, radio, infra-red, optical, and other hard X-ray /gamma-ray data, collected within 3 months of the LBAS data taking period, we were able to assemble high-quality and quasi-simultaneous spectral energy distributions (SED) for 48 LBAS blazars. The SED of these gamma-ray sources is similar to that of blazars discovered at other wavelengths, clearly showing, in the usual log v-log v Fv representation, the typical broadband spectral signatures normally attributed to a combination of low-energy synchrotron radiation followed by inverse Compton emission of one or more components. We have used these SED to characterize the peak intensity of both the low- and the high-energy components. The results have been used to derive empirical relationships that estimate the position of the two peaks from the broadband colors (i.e., the radio to optical, alpha(sub ro) , and optical to X-ray, alpha(sub ox), spectral slopes) and from the gamma-ray spectral index. Our data show that the synchrotron peak frequency (v(sup S) (sub peak)) is positioned between 10(exp 12.5) and 10(exp 14) Hz in broad-lined flat spectrum radio quasars (FSRQs) and between 10(exp 13) and 10(exp 17) Hz in featureless BL Lacertae objects. We find that the gamma-ray spectral slope is strongly correlated with the synchrotron peak energy and with the X-ray spectral index, as expected at first order in synchrotron-inverse Compton scenarios. However, simple homogeneous, one-zone, synchrotron self-Compton (SSC) models cannot explain most of our SED, especially in the case of FSRQs and low energy peaked (LBL) BL Lacs. More complex models involving external Compton radiation or multiple SSC components are required to reproduce the overall SED and the observed spectral variability. While more than

  10. Quasar Spectral Energy Distributions As A Function Of Physical Property

    NASA Astrophysics Data System (ADS)

    Townsend, Shonda; Ganguly, R.; Stark, M. A.; Derseweh, J. A.; Richmond, J. M.

    2012-05-01

    Galaxy evolution models have shown that quasars are a crucial ingredient in the evolution of massive galaxies. Outflows play a key role in the story of quasars and their host galaxies, by helping regulate the accretion process, the star-formation rate and mass of the host galaxy (i.e., feedback). The prescription for modeling outflows as a contributor to feedback requires knowledge of the outflow velocity, geometry, and column density. In particular, we need to understand how these depend on physical parameters and how much is determined stochastically (and with what distribution). In turn, models of outflows have shown particular sensitivity to the shape of the spectral energy distribution (SED), depending on the UV luminosity to transfer momentum to the gas, the X-ray luminosity to regulate how efficiently that transfer can be, etc. To investigate how SED changes with physical properties, we follow up on Richards et al. (2006), who constructed SEDs with varying luminosity. Here, we construct SEDs as a function of redshift, and physical property (black hole mass, bolometric luminosity, Eddington ratio) for volume limited samples drawn from the Sloan Digital Sky Survey, with photometry supplemented from 2MASS, WISE, GALEX, ROSAT, and Chandra. To estimate black hole masses, we adopt the scaling relations from Greene & Ho (2005) based on the H-alpha emission line FWHM. This requires redshifts less than 0.4. To construct volume-limited subsamples, we begin by adopting g=19.8 as a nominal limiting magnitude over which we are guaranteed to detect z<0.4 quasars. At redshift 0.4, we are complete down to Mg=-21.8, which yields 3300 objects from Data Release 7. At z=0.1, we are complete down to Mg=-18.5. This material is based upon work supported by the National Aeronautics and Space Administration under Grant No. 09-ADP09-0016 issued through the Astrophysics Data Analysis Program.

  11. Transient absolute robustness in stochastic biochemical networks.

    PubMed

    Enciso, German A

    2016-08-01

    Absolute robustness allows biochemical networks to sustain a consistent steady-state output in the face of protein concentration variability from cell to cell. This property is structural and can be determined from the topology of the network alone regardless of rate parameters. An important question regarding these systems is the effect of discrete biochemical noise in the dynamical behaviour. In this paper, a variable freezing technique is developed to show that under mild hypotheses the corresponding stochastic system has a transiently robust behaviour. Specifically, after finite time the distribution of the output approximates a Poisson distribution, centred around the deterministic mean. The approximation becomes increasingly accurate, and it holds for increasingly long finite times, as the total protein concentrations grow to infinity. In particular, the stochastic system retains a transient, absolutely robust behaviour corresponding to the deterministic case. This result contrasts with the long-term dynamics of the stochastic system, which eventually must undergo an extinction event that eliminates robustness and is completely different from the deterministic dynamics. The transiently robust behaviour may be sufficient to carry out many forms of robust signal transduction and cellular decision-making in cellular organisms. PMID:27581485

  12. Space and energy. [space systems for energy generation, distribution and control

    NASA Technical Reports Server (NTRS)

    Bekey, I.

    1976-01-01

    Potential contributions of space to energy-related activities are discussed. Advanced concepts presented include worldwide energy distribution to substation-sized users using low-altitude space reflectors; powering large numbers of large aircraft worldwide using laser beams reflected from space mirror complexes; providing night illumination via sunlight-reflecting space mirrors; fine-scale power programming and monitoring in transmission networks by monitoring millions of network points from space; prevention of undetected hijacking of nuclear reactor fuels by space tracking of signals from tagging transmitters on all such materials; and disposal of nuclear power plant radioactive wastes in space.

  13. Absolute rates of hole transfer in DNA.

    PubMed

    Senthilkumar, Kittusamy; Grozema, Ferdinand C; Guerra, Célia Fonseca; Bickelhaupt, F Matthias; Lewis, Frederick D; Berlin, Yuri A; Ratner, Mark A; Siebbeles, Laurens D A

    2005-10-26

    Absolute rates of hole transfer between guanine nucleobases separated by one or two A:T base pairs in stilbenedicarboxamide-linked DNA hairpins were obtained by improved kinetic analysis of experimental data. The charge-transfer rates in four different DNA sequences were calculated using a density-functional-based tight-binding model and a semiclassical superexchange model. Site energies and charge-transfer integrals were calculated directly as the diagonal and off-diagonal matrix elements of the Kohn-Sham Hamiltonian, respectively, for all possible combinations of nucleobases. Taking into account the Coulomb interaction between the negative charge on the stilbenedicarboxamide linker and the hole on the DNA strand as well as effects of base pair twisting, the relative order of the experimental rates for hole transfer in different hairpins could be reproduced by tight-binding calculations. To reproduce quantitatively the absolute values of the measured rate constants, the effect of the reorganization energy was taken into account within the semiclassical superexchange model for charge transfer. The experimental rates could be reproduced with reorganization energies near 1 eV. The quantum chemical data obtained were used to discuss charge carrier mobility and hole-transport equilibria in DNA. PMID:16231945

  14. Design, modeling, simulation and evaluation of a distributed energy system

    NASA Astrophysics Data System (ADS)

    Cultura, Ambrosio B., II

    This dissertation presents the design, modeling, simulation and evaluation of distributed energy resources (DER) consisting of photovoltaics (PV), wind turbines, batteries, a PEM fuel cell and supercapacitors. The distributed energy resources installed at UMass Lowell consist of the following: 2.5kW PV, 44kWhr lead acid batteries and 1500W, 500W & 300W wind turbines, which were installed before year 2000. Recently added to that are the following: 10.56 kW PV array, 2.4 kW wind turbine, 29 kWhr Lead acid batteries, a 1.2 kW PEM fuel cell and 4-140F supercapacitors. Each newly added energy resource has been designed, modeled, simulated and evaluated before its integration into the existing PV/Wind grid-connected system. The Mathematical and Simulink model of each system was derived and validated by comparing the simulated and experimental results. The Simulated results of energy generated from a 10.56kW PV system are in good agreement with the experimental results. A detailed electrical model of a 2.4kW wind turbine system equipped with a permanent magnet generator, diode rectifier, boost converter and inverter is presented. The analysis of the results demonstrates the effectiveness of the constructed simulink model, and can be used to predict the performance of the wind turbine. It was observed that a PEM fuel cell has a very fast response to load changes. Moreover, the model has validated the actual operation of the PEM fuel cell, showing that the simulated results in Matlab Simulink are consistent with the experimental results. The equivalent mathematical equation, derived from an electrical model of the supercapacitor, is used to simulate its voltage response. The model is completely capable of simulating its voltage behavior, and can predict the charge time and discharge time of voltages on the supercapacitor. The bi-directional dc-dc converter was designed in order to connect the 48V battery bank storage to the 24V battery bank storage. This connection was

  15. Optomechanics for absolute rotation detection

    NASA Astrophysics Data System (ADS)

    Davuluri, Sankar

    2016-07-01

    In this article, we present an application of optomechanical cavity for the absolute rotation detection. The optomechanical cavity is arranged in a Michelson interferometer in such a way that the classical centrifugal force due to rotation changes the length of the optomechanical cavity. The change in the cavity length induces a shift in the frequency of the cavity mode. The phase shift corresponding to the frequency shift in the cavity mode is measured at the interferometer output to estimate the angular velocity of absolute rotation. We derived an analytic expression to estimate the minimum detectable rotation rate in our scheme for a given optomechanical cavity. Temperature dependence of the rotation detection sensitivity is studied.

  16. The Absolute Spectrum Polarimeter (ASP)

    NASA Technical Reports Server (NTRS)

    Kogut, A. J.

    2010-01-01

    The Absolute Spectrum Polarimeter (ASP) is an Explorer-class mission to map the absolute intensity and linear polarization of the cosmic microwave background and diffuse astrophysical foregrounds over the full sky from 30 GHz to 5 THz. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r much greater than 1O(raised to the power of { -3}) and Compton distortion y < 10 (raised to the power of{-6}). We describe the ASP instrument and mission architecture needed to detect the signature of an inflationary epoch in the early universe using only 4 semiconductor bolometers.

  17. Absolute calibration of optical flats

    DOEpatents

    Sommargren, Gary E.

    2005-04-05

    The invention uses the phase shifting diffraction interferometer (PSDI) to provide a true point-by-point measurement of absolute flatness over the surface of optical flats. Beams exiting the fiber optics in a PSDI have perfect spherical wavefronts. The measurement beam is reflected from the optical flat and passed through an auxiliary optic to then be combined with the reference beam on a CCD. The combined beams include phase errors due to both the optic under test and the auxiliary optic. Standard phase extraction algorithms are used to calculate this combined phase error. The optical flat is then removed from the system and the measurement fiber is moved to recombine the two beams. The newly combined beams include only the phase errors due to the auxiliary optic. When the second phase measurement is subtracted from the first phase measurement, the absolute phase error of the optical flat is obtained.

  18. Infrared Spectral Energy Distributions of Nearby Dwarf Carbon Stars

    NASA Astrophysics Data System (ADS)

    Lowrance, Patrick

    2014-06-01

    The discovery of G77-61 (Dahn et al. 1977) -- a star with a carbon-rich spectrum a mere 58 pc away and therefore of relatively low luminosity -- led to the recognition that _dwarf_ carbon (dC) stars exist. As more dCs are now known, the accepted paradigm of the presence of atmospheric carbon is that dCs must contain a white dwarf secondary. While the white dwarf companion was going through an AGB stage, it deposited carbon-rich material in the atmosphere of the lower-mass (and now brighter) dwarf star. Indeed, a handful of the dC's have exhibited radial velocity signatures consistent with this picture. To allow for the carbon to still be present in the atmosphere past the AGB stage, a replenishing outer shell or disk has been proposed. Current understanding of the formation and evolution of a dC is, however, limited by the small number of objects and observations. We present a full range of fluxes and flux limits from 1 - 160 um including 2MASS, WISE, Spitzer, and Herschel observations for a list of the nearest carbon dwarfs. We reconstruct the spectral energy distribution exploring the mid-infrared region where any residual debris disks would be detectable. The carbon dwarfs have been historically studied in the visible, and these new infrared observations provide a picture of the circumstellar dust.

  19. Electron energy distributions in a magnetized inductively coupled plasma

    SciTech Connect

    Song, Sang-Heon E-mail: Sang-Heon.Song@us.tel.com; Yang, Yang; Kushner, Mark J.

    2014-09-15

    Optimizing and controlling electron energy distributions (EEDs) is a continuing goal in plasma materials processing as EEDs determine the rate coefficients for electron impact processes. There are many strategies to customize EEDs in low pressure inductively coupled plasmas (ICPs), for example, pulsing and choice of frequency, to produce the desired plasma properties. Recent experiments have shown that EEDs in low pressure ICPs can be manipulated through the use of static magnetic fields of sufficient magnitudes to magnetize the electrons and confine them to the electromagnetic skin depth. The EED is then a function of the local magnetic field as opposed to having non-local properties in the absence of the magnetic field. In this paper, EEDs in a magnetized inductively coupled plasma (mICP) sustained in Ar are discussed with results from a two-dimensional plasma hydrodynamics model. Results are compared with experimental measurements. We found that the character of the EED transitions from non-local to local with application of the static magnetic field. The reduction in cross-field mobility increases local electron heating in the skin depth and decreases the transport of these hot electrons to larger radii. The tail of the EED is therefore enhanced in the skin depth and depressed at large radii. Plasmas densities are non-monotonic with increasing pressure with the external magnetic field due to transitions between local and non-local kinetics.

  20. Simulated galaxy interactions as probes of merger spectral energy distributions

    SciTech Connect

    Lanz, Lauranne; Zezas, Andreas; Smith, Howard A.; Ashby, Matthew L. N.; Fazio, Giovanni G.; Hernquist, Lars; Hayward, Christopher C.; Brassington, Nicola

    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.

  1. Energy Distribution of Electrons in Radiation Induced-Helium Plasmas. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Lo, R. H.

    1972-01-01

    Energy distribution of high energy electrons as they slow down and thermalize in a gaseous medium is studied. The energy distribution in the entire energy range from source energies down is studied analytically. A helium medium in which primary electrons are created by the passage of heavy-charged particles from nuclear reactions is emphasized. A radiation-induced plasma is of interest in a variety of applications, such as radiation pumped lasers and gaseous core nuclear reactors.

  2. 16 CFR Table 4 to Part 1512 - Relative Energy Distribution of Sources

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Relative Energy Distribution of Sources 4... SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Table 4 Table 4 to Part 1512—Relative Energy Distribution of Sources Wave length (nanometers) Relative energy 380 9.79 390 12.09 400 14.71 410 17.68 420...

  3. 16 CFR Table 4 to Part 1512 - Relative Energy Distribution of Sources

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Relative Energy Distribution of Sources 4... SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Table 4 Table 4 to Part 1512—Relative Energy Distribution of Sources Wave length (nanometers) Relative energy 380 9.79 390 12.09 400 14.71 410 17.68 420...

  4. 16 CFR Table 4 to Part 1512 - Relative Energy Distribution of Sources

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Relative Energy Distribution of Sources 4... SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Table 4 Table 4 to Part 1512—Relative Energy Distribution of Sources Wave length (nanometers) Relative energy 380 9.79 390 12.09 400 14.71 410 17.68 420...

  5. 16 CFR Table 4 to Part 1512 - Relative Energy Distribution of Sources

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Relative Energy Distribution of Sources 4... SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Table 4 Table 4 to Part 1512—Relative Energy Distribution of Sources Wave length (nanometers) Relative energy 380 9.79 390 12.09 400 14.71 410 17.68 420...

  6. 16 CFR Table 4 to Part 1512 - Relative Energy Distribution of Sources

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Relative Energy Distribution of Sources 4... SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR BICYCLES Pt. 1512, Table 4 Table 4 to Part 1512—Relative Energy Distribution of Sources Wave length (nanometers) Relative energy 380 9.79 390 12.09 400 14.71 410 17.68 420...

  7. 10 CFR 431.193 - Test procedures for measuring energy consumption of distribution transformers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... procedures for measuring the energy efficiency of distribution transformers for purposes of EPCA are... EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Distribution Transformers Test Procedures... 10 Energy 3 2012-01-01 2012-01-01 false Test procedures for measuring energy consumption...

  8. 10 CFR 431.193 - Test procedures for measuring energy consumption of distribution transformers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... procedures for measuring the energy efficiency of distribution transformers for purposes of EPCA are... EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Distribution Transformers Test Procedures... 10 Energy 3 2010-01-01 2010-01-01 false Test procedures for measuring energy consumption...

  9. 10 CFR 431.193 - Test procedures for measuring energy consumption of distribution transformers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... procedures for measuring the energy efficiency of distribution transformers for purposes of EPCA are... EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Distribution Transformers Test Procedures... 10 Energy 3 2014-01-01 2014-01-01 false Test procedures for measuring energy consumption...

  10. 10 CFR 431.193 - Test procedures for measuring energy consumption of distribution transformers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... procedures for measuring the energy efficiency of distribution transformers for purposes of EPCA are... EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Distribution Transformers Test Procedures... 10 Energy 3 2013-01-01 2013-01-01 false Test procedures for measuring energy consumption...

  11. 10 CFR 431.193 - Test procedures for measuring energy consumption of distribution transformers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... procedures for measuring the energy efficiency of distribution transformers for purposes of EPCA are... EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Distribution Transformers Test Procedures... 10 Energy 3 2011-01-01 2011-01-01 false Test procedures for measuring energy consumption...

  12. 76 FR 50148 - Notice of Intent to Negotiate Proposed Rule on Energy Efficiency Standards for Distribution...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-12

    ... Part 431 RIN 1904-AC62 Notice of Intent to Negotiate Proposed Rule on Energy Efficiency Standards for Distribution Transformers AGENCY: Office of Energy Efficiency and Renewable Energy, Department of Energy... Negotiated Rulemaking Act (NRA) to negotiate proposed Federal standards for the energy efficiency of...

  13. Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices

    DOEpatents

    Chassin, David P.; Donnelly, Matthew K.; Dagle, Jeffery E.

    2006-12-12

    Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices are described. In one aspect, an electrical power distribution control method includes providing electrical energy from an electrical power distribution system, applying the electrical energy to a load, providing a plurality of different values for a threshold at a plurality of moments in time and corresponding to an electrical characteristic of the electrical energy, and adjusting an amount of the electrical energy applied to the load responsive to an electrical characteristic of the electrical energy triggering one of the values of the threshold at the respective moment in time.

  14. Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices

    DOEpatents

    Chassin, David P.; Donnelly, Matthew K.; Dagle, Jeffery E.

    2011-12-06

    Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices are described. In one aspect, an electrical power distribution control method includes providing electrical energy from an electrical power distribution system, applying the electrical energy to a load, providing a plurality of different values for a threshold at a plurality of moments in time and corresponding to an electrical characteristic of the electrical energy, and adjusting an amount of the electrical energy applied to the load responsive to an electrical characteristic of the electrical energy triggering one of the values of the threshold at the respective moment in time.

  15. Advanced Power Electronics Interfaces for Distributed Energy Workshop Summary: August 24, 2006, Sacramento, California

    SciTech Connect

    Treanton, B.; Palomo, J.; Kroposki, B.; Thomas, H.

    2006-10-01

    The Advanced Power Electronics Interfaces for Distributed Energy Workshop, sponsored by the California Energy Commission Public Interest Energy Research program and organized by the National Renewable Energy Laboratory, was held Aug. 24, 2006, in Sacramento, Calif. The workshop provided a forum for industry stakeholders to share their knowledge and experience about technologies, manufacturing approaches, markets, and issues in power electronics for a range of distributed energy resources. It focused on the development of advanced power electronic interfaces for distributed energy applications and included discussions of modular power electronics, component manufacturing, and power electronic applications.

  16. Lifetime optimization of wireless sensor network by a better nodes positioning and energy distribution

    NASA Astrophysics Data System (ADS)

    Lebreton, J. M.; Murad, N. M.

    2014-10-01

    The purpose of this paper is to propose a method of energy distribution on a Wireless Sensor Network (WSN). Nodes are randomly positioned and the sink is placed at the centre of the surface. Simulations show that relay nodes around the sink are too much requested to convey data, which substantially reduces their lifetime. So, several algorithmic solutions are presented to optimize the energy distribution on each node, compared to the classical uniform energy distribution. Their performance is discussed in terms of failure rate of data transmission and network lifetime. Moreover, the total energy distributed on all nodes before the deployment is invariable and some non-uniform energy distributions are created. Finally, simulations show that every energy distributions greatly improve the WSN lifetime and decrease the failure rate of data transmission.

  17. Development of a High-Speed Static Switch for Distributed Energy and Microgrid Applications

    SciTech Connect

    Kroposki, B.; Pink, C.; Lynch, J.; John, V.; Meor Daniel, S.; Benedict, E.; Vihinen, I.

    2007-01-01

    Distributed energy resources can provide power to local loads in the electric distribution system and benefits such as improved reliability. Microgrids are intentional islands formed at a facility or in an electrical distribution system that contains at least one distributed resource and associated loads. Microgrids that operate both electrical generation and loads in a coordinated manner can offer additional benefits to the customer and local utility. The loads and energy sources can be disconnected from and reconnected to the area or local utility with minimal disruption to the local loads, thereby improving reliability. This paper details the development and testing of a highspeed static switch for distributed energy and microgrid applications.

  18. The Effect of Distributed Energy Resource Competition with Central Generation

    SciTech Connect

    Hadley, SW

    2003-12-10

    Distributed Energy Resource (DER) has been touted as a clean and efficient way to generate electricity at end-use sites, potentially allowing the exhaust heat to be put to good use as well. However, despite its environmental acceptability compared to many other types of generation, it has faced some disapproval because it may displace other, cleaner generation technologies. The end result could be more pollution than if the DER were not deployed. On the other hand, the DER may be competing against older power plants. If the DER is built then these other plants may be retired sooner, reducing their emissions. Or it may be that DER does not directly compete against either new or old plant capacity at the decision-maker level, and increased DER simply reduces the amount of time various plants operate. The key factor is what gets displaced if DER is added. For every kWh made by DER a kWh (or more with losses) of other production is not made. If enough DER is created, some power plants will get retired or not get built so not only their production but their capacity is displaced. Various characteristics of the power system in a region will influence how DER impacts the operation of the grid. The growth in demand in the region may influence whether new plants are postponed or old plants retired. The generation mix, including the fuel types, efficiencies, and emission characteristics of the plants in the region will factor into the overall competition. And public policies such as ease of new construction, emissions regulations, and fuel availability will also come into consideration.

  19. Constructing and Analyzing Spectral Energy Distributions with the Virtual Observatory

    NASA Astrophysics Data System (ADS)

    Laurino, Omar; Busko, I.; Cresitello-Dittmar, M.; D'Abrusco, R.; Doe, S.; Evans, J.; Pevunova, O.; Norris, P.

    2013-01-01

    Spectral energy distributions (SEDs) are a common and useful means of assessing the relative contributions of different emission processes occurring within an object. Iris, the Virtual Astronomical Observatory (VAO) SED tool, seamlessly combines key features of several existing astronomical software applications to streamline and enhance the SED analysis process. With Iris, users may build and display SEDs, browse data and metadata and apply filters to them, fit models to SEDs, and calculate confidence limits on best-fit parameters. SED data may be built from a number of sources using the SED Builder. Iris supports the Simple Application Messaging Protocol for interoperability with other Virtual Observatory applications, like the VAO Data Discovery tool, and can directly fetch SEDs from the NASA Extragalactic Database SED service. Particular attention has been paid to the integration of user spectrophotometric data from files in several different formats. File readers for custom formats can be provided at runtime, as well as custom models to fit the data, as template libraries for template fitting or arbitrary python functions. New functionalities can be added by installing plugins, i.e. third party components that are developed using the Iris Software Development Kit. The VAO was established as a partnership of the Associated Universities, Inc. and the Association of Universities for Research in Astronomy, Inc. Iris Individual components have also been supported by the National Aeronautics and Space Administration (NASA) through the Chandra X-ray Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of the NASA contract NAS8-03060, and by the Space Telescope Science Institute, operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. This research has made use of the NASA/IPAC Extragalactic Database which is operated by the Jet Propulsion Laboratory, California Institute of

  20. Absolute Spectrophotometry of 237 Open Cluster Stars

    NASA Astrophysics Data System (ADS)

    Clampitt, L.; Burstein, D.

    1994-12-01

    We present absolute spectrophotometry of 237 stars in 7 nearby open clusters: Hyades, Pleiades, Alpha Persei, Praesepe, Coma Berenices, IC 4665, and M 39. The observations were taken using the Wampler single-channel scanner (Wampler 1966) on the Crossley 0.9m telescope at Lick Observatory from July 1973 through December 1974. 21 bandpasses spanning the spectral range 3500 Angstroms to 7780 Angstroms were observed for each star, with bandwiths ranging from 32Angstroms to 64 Angstroms. Data are standardized to the Hayes--Latham (1975) system. Our measurements are compared to filter colors on the Johnson BV, Stromgren ubvy, and Geneva U V B_1 B_2 V_1 G systems, as well as to spectrophotometry of a few stars published by Gunn, Stryker & Tinsley and in the Spectrophotometric Standards Catalog (Adelman; as distributed by the NSSDC). Both internal and external comparisons to the filter systems indicate a formal statistical accuracy per bandpass of 0.01 to 0.02 mag, with apparent larger ( ~ 0.03 mag) differences in absolute calibration between this data set and existing spectrophotometry. These data will comprise part of the spectrophotometry that will be used to calibrate the Beijing-Arizona-Taipei-Connecticut Color Survey of the Sky (see separate paper by Burstein et al. at this meeting).

  1. Optimal Combination of Distributed Energy System in an Eco-Campusof Japan

    SciTech Connect

    Yang, Yongwen; Gao, Weijun; Zhou, Nan; Marnay, Chris

    2006-06-14

    In this study, referring to the Distributed Energy Resources Customer Adoption Model (DER-CAM) which was developed by the Ernest Orlando Lawrence Berkeley National Laboratory (LBNL), E-GAMS programmer is developed with a research of database of energy tariffs, DER (Distributed Energy Resources) technology cost and performance characteristics, and building energy consumption in Japan. E-GAMS is a tool designed to find the optimal combination of installed equipment and an idealized operating schedule to minimize a site's energy bills. In this research, by using E-GAMS, we present a tool to select the optimal combination of distributed energy system for an Ecological-Campus, Kitakyushu, Science and Research Park (KSRP). We discuss the effects of the combination of distributed energy technologies on the energy saving, economic efficiency and environmental benefits.

  2. Variations of Low-energy Ion Distributions Measured in the Heliosheath

    SciTech Connect

    Decker, R. B.; Roelof, E. C.; Hill, M. E.; Krimigis, S. M.

    2010-12-30

    This report is an update of low-energy ion intensities and angular distributions measured recently by the Low Energy Charged Particle instruments on the Voyager 1 and 2 spacecraft in the inner heliosheath.

  3. Charge state dependence of cathodic vacuum arc ion energy andvelocity distributions

    SciTech Connect

    Rosen, Johanna; Schneider, Jochen M.; Anders, Andre

    2006-08-15

    In the literature, conflicting conclusions are reported concerning the charge state dependence of cathodic arc ion energy and velocity distributions. It appears that data from electrostatic energy analyzers indicate charge state dependence of ion energy, whereas time-of-flight methods support charge state independence of ion velocity. Here we present charge-state-resolved ion energy distributions and calculate the corresponding ion velocity distributions in aluminum vacuum arc plasma. We show that the conflicting conclusions reported in the literature for the two different characterization techniques may originate from the commonly employed data interpretation of energy and velocity, in which peak values and average values are not carefully distinguished.

  4. The AFGL absolute gravity program

    NASA Technical Reports Server (NTRS)

    Hammond, J. A.; Iliff, R. L.

    1978-01-01

    A brief discussion of the AFGL's (Air Force Geophysics Laboratory) program in absolute gravity is presented. Support of outside work and in-house studies relating to gravity instrumentation are discussed. A description of the current transportable system is included and the latest results are presented. These results show good agreement with measurements at the AFGL site by an Italian system. The accuracy obtained by the transportable apparatus is better than 0.1 microns sq sec 10 microgal and agreement with previous measurements is within the combined uncertainties of the measurements.

  5. Fundamental Parameters and Spectral Energy Distributions of Young and Field Age Objects with Masses Spanning the Stellar to Planetary Regime

    NASA Astrophysics Data System (ADS)

    Filippazzo, Joseph C.; Rice, Emily L.; Faherty, Jacqueline; Cruz, Kelle L.; Van Gordon, Mollie M.; Looper, Dagny L.

    2015-09-01

    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 (Lbol) and radius estimates from evolutionary models give semi-empirical effective temperatures (Teff) 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 Teff, 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 Teff 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 MH magnitude.

  6. Reducing Molecular Flexibility by Cyclization for Elucidation of Absolute Configuration by CD Calculations: Daurichromenic Acid.

    PubMed

    Mándi, Attila; Swamy, Mahadeva M M; Taniguchi, Tohru; Anetai, Masaki; Monde, Kenji

    2016-06-01

    Circular dichroism (CD) calculations of flexible natural products have been difficult because of the large number of low-energy conformers and ambiguous Boltzmann distributions. In this article, through electronic (ECD) and vibrational (VCD) studies on a natural product, (+)-daurichromenic acid, we demonstrate that derivatization of a flexible molecule can dramatically reduce its flexibility. This work also shows the usefulness of derivatization for diminishing computational expenses required for optimization and CD calculations, and for increasing the reliability of the assignment of absolute configuration. Chirality 28:453-459, 2016. © 2016 Wiley Periodicals, Inc. PMID:27172768

  7. 76 FR 45471 - Energy Efficiency Standards for Distribution Transformers; Notice of Intent To Negotiate Proposed...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-29

    ...; ] DEPARTMENT OF ENERGY 10 CFR Chapter II RIN 1904-AC04 Energy Efficiency Standards for Distribution Transformers; Notice of Intent To Negotiate Proposed Rule AGENCY: Office of Energy Efficiency and Renewable... Act (NRA) to negotiate proposed Federal standards for the energy efficiency of liquid immersed...

  8. Absence of absolutely continuous spectrum for random scattering zippers

    NASA Astrophysics Data System (ADS)

    Boumaza, Hakim; Marin, Laurent

    2015-02-01

    A scattering zipper is a system obtained by concatenation of scattering events with equal even number of incoming and outgoing channels. The associated scattering zipper operator is the unitary analog of Jacobi matrices with matrix entries. For infinite identical events and independent and identically distributed random phases, Lyapunov exponents positivity is proved and yields absence of absolutely continuous spectrum by Kotani's theory.

  9. The Spectral Energy Distribution of the Coldest Known Brown Dwarf

    NASA Astrophysics Data System (ADS)

    Luhman, K. L.; Esplin, T. L.

    2016-09-01

    WISE J085510.83–071442.5 (hereafter WISE 0855–0714) is the coldest known brown dwarf (∼250 K) and the fourth-closest known system to the Sun (2.2 pc). It has been previously detected only in the J band and two mid-IR bands. To better measure its spectral energy distribution (SED), we have performed deep imaging of WISE 0855–0714 in six optical and near-IR bands with Gemini Observatory, the Very Large Telescope, and the Hubble Space Telescope. Five of the bands show detections, although one detection is marginal (S/N ∼ 3). We also have obtained two epochs of images with the Spitzer Space Telescope for use in refining the parallax of the brown dwarf. By combining astrometry from this work and previous studies, we have derived a parallax of 0.449 ± 0.008″ (2.23 ± 0.04 pc). We have compared our photometry for WISE 0855–0714 to data for known Y dwarfs and to the predictions of three suites of models by Saumon et al. and Morley et al. that are defined by the presence or absence of clouds and nonequilibrium chemistry. Our estimates of Y ‑ J and J ‑ H for WISE 0855–0714 are redder than colors of other Y dwarfs, confirming a predicted reversal of near-IR colors to redder values at temperatures below 300–400 K. In color–magnitude diagrams, no single suite of models provides a clearly superior match to the sequence formed by WISE 0855–0714 and other Y dwarfs. Instead, the best-fitting model changes from one diagram to the next. Similarly, all of the models have substantial differences from the SED of WISE 0855–0714. As a result, we are currently unable to constrain the presence of clouds or nonequilibrium chemistry in its atmosphere. Based on observations made with the Spitzer Space Telescope, the NASA/ESA Hubble Space Telescope, Gemini Observatory, and the ESO Telescopes at Paranal Observatory.

  10. MEAN SPECTRAL ENERGY DISTRIBUTIONS AND BOLOMETRIC CORRECTIONS FOR LUMINOUS QUASARS

    SciTech Connect

    Krawczyk, Coleman M.; Richards, Gordon T.; Mehta, Sajjan S.; Vogeley, Michael S.; Gallagher, S. C.; Leighly, Karen M.; Ross, Nicholas P.; Schneider, Donald P.

    2013-05-01

    We explore the mid-infrared (mid-IR) through ultraviolet (UV) spectral energy distributions (SEDs) of 119,652 luminous broad-lined quasars with 0.064 < z < 5.46 using mid-IR data from Spitzer and WISE, near-infrared data from the Two Micron All Sky Survey and UKIDSS, optical data from the Sloan Digital Sky Survey, and UV data from the Galaxy Evolution Explorer. The mean SED requires a bolometric correction (relative to 2500 A) of BC{sub 2500A} =2.75 {+-} 0.40 using the integrated light from 1 {mu}m-2 keV, and we further explore the range of bolometric corrections exhibited by individual objects. In addition, we investigate the dependence of the mean SED on various parameters, particularly the UV luminosity for quasars with 0.5 {approx}< z {approx}< 3 and the properties of the UV emission lines for quasars with z {approx}> 1.6; the latter is a possible indicator of the strength of the accretion disk wind, which is expected to be SED-dependent. Luminosity-dependent mean SEDs show that, relative to the high-luminosity SED, low-luminosity SEDs exhibit a harder (bluer) far-UV spectral slope ({alpha}{sub UV}), a redder optical continuum, and less hot dust. Mean SEDs constructed instead as a function of UV emission line properties reveal changes that are consistent with known Principal Component Analysis trends. A potentially important contribution to the bolometric correction is the unseen extreme UV (EUV) continuum. Our work suggests that lower-luminosity quasars and/or quasars with disk-dominated broad emission lines may require an extra continuum component in the EUV that is not present (or much weaker) in high-luminosity quasars with strong accretion disk winds. As such, we consider four possible models and explore the resulting bolometric corrections. Understanding these various SED-dependent effects will be important for accurate determination of quasar accretion rates.

  11. Energy distribution functions of kilovolt ions in a modified Penning discharge

    NASA Technical Reports Server (NTRS)

    Roth, J. R.

    1972-01-01

    The distribution function of ion energy parallel to the magnetic field of a Penning discharge was measured with a retarding potential energy analyzer. Simultaneous measurements of the ion energy distribution function perpendicular to the magnetic field were made with a charge-exchange neutral detector. The ion energy distribution functions are approximately Maxwellian, and their kinetic temperatures are equal within experimental error. This suggests that turbulent processes previously observed Maxwellianize the velocity distribution along a radius in velocity space, and result in an isotropic energy distribution. The kinetic temperatures are on the order of kilovolts, and the tails of the ion energy distribution functions are Maxwellian up to a factor of 7 e-folds in energy. When the distributions depart from Maxwellian, they are enhanced above the Maxwellian tail. Above densities of about 10 to the 10th power particles/cc, this enhancement appears to be the result of a second, higher temperature Maxwellian distribution. At these high particle energies, only the ions perpendicular to the magnetic field lines were investigated.

  12. VAR Support from Distributed Wind Energy Resources: Preprint

    SciTech Connect

    Romanowitz, H.; Muljadi, E.; Butterfield, C. P.; Yinger, R.

    2004-07-01

    As the size and quantity of wind farms and other distributed generation facilities increase, especially in relation to local grids, the importance of a reactive power compensator or VAR support from these facilities becomes more significant. Poorly done, it can result in cycling or inadequate VAR support, and the local grid could experience excessive voltage regulation and, ultimately, instability. Improved wind turbine and distributed generation power control technologies are creating VAR support capabilities that can be used to enhance the voltage regulation and stability of local grids. Locating VAR support near the point of consumption, reducing step size, and making the control active all improve the performance of the grid. This paper presents and discusses alternatives for improving the integration of VAR support from distributed generation facilities such as wind farms. We also examine the relative effectiveness of distributed VAR support on the local grid and how it can b e integrated with the VAR support of the grid operator.

  13. Low-energy ion distribution functions on a magnetically quiet day at geostationary altitude /L = 7/

    NASA Technical Reports Server (NTRS)

    Singh, N.; Raitt, W. J.; Yasuhara, F.

    1982-01-01

    Ion energy and pitch angle distribution functions are examined for a magnetically quiet day using averaged data from ATS 6. For both field-aligned and perpendicular fluxes, the populations have a mixture of characteristic energies, and the distribution functions can be fairly well approximated by Maxwellian distributions over three different energy bands in the range 3-600 eV. Pitch angle distributions varying with local time, and energy distributions are used to compute total ion density. Pitch angle scattering mechanisms responsible for the observed transformation of pitch angle distribution are examined, and it is found that a magnetic noise of a certain power spectral density belonging to the electromagnetic ion cyclotron mode near the ion cyclotron frequency can be effective in trapping the field aligned fluxes by pitch angle scattering.

  14. Energy storage management system with distributed wireless sensors

    SciTech Connect

    Farmer, Joseph C.; Bandhauer, Todd M.

    2015-12-08

    An energy storage system having a multiple different types of energy storage and conversion devices. Each device is equipped with one or more sensors and RFID tags to communicate sensor information wirelessly to a central electronic management system, which is used to control the operation of each device. Each device can have multiple RFID tags and sensor types. Several energy storage and conversion devices can be combined.

  15. Terminal energy distribution of blast waves from bursting spheres

    NASA Technical Reports Server (NTRS)

    Adamczyk, A. A.; Strehlow, R. A.

    1977-01-01

    The calculation results for the total energy delivered to the surroundings by the burst of an idealized massless sphere containing an ideal gas are presented. The logic development of various formulas for sphere energy is also presented. For all types of sphere bursts the fraction of the total initial energy available in the sphere that is delivered to the surroundings is shown to lie between that delivered for the constant pressure addition of energy to a source region and that delivered by isentropic expansion of the sphere. The relative value of E sub/Q increases at fixed sphere pressure/surrounding pressure as sphere temperature increases because the velocity of sound increases.

  16. Notes on Van der Meer scan for absolute luminosity measurement

    NASA Astrophysics Data System (ADS)

    Balagura, Vladislav

    2011-10-01

    The absolute luminosity can be measured in an accelerator by sweeping beams transversely across each other in the so-called van der Meer scan. We prove that the method can be applied in the general case of arbitrary beam directions and a separation scan plane. A simple method to develop an image of the beam in its transverse plane from spatial distributions of interaction vertexes is also proposed. From the beam images one can determine their overlap and the absolute luminosity. This provides an alternative way of the luminosity measurement during van der Meer scan.

  17. Measurement of energy distribution in flowing hydrogen microwave plasmas

    NASA Technical Reports Server (NTRS)

    Chapman, R.; Morin, T.; Finzel, M.; Hawley, M. C.

    1985-01-01

    An electrothermal propulsion concept utilizing a microwave plasma system as the mechanism to convert electromagnetic energy into kinetic energy of a flowing gas is investigated. A calorimetry system enclosing a microwave plasma system has been developed to accurately measure the energy inputs and outputs of the microwave plasma system. The rate of energy transferred to the gas can be determined to within + or - 1.8 W from an energy balance around the microwave plasma system. The percentage of the power absorbed by the microwave plasma system transferred to the hydrogen gas as it flows through the system is found to increase with the increasing flow rate, to decrease with the increasing pressure, and to be independent of the absorbed power. An upper bound for the hydrogen gas temperature is estimated from the energy content, heat capacity, and flow rate of the gas stream. A lower bound for an overall heat-transfer coefficient is then calculated, characterizing the energy loss from the hydrogen gas stream to the air cooling of the plasma discharge tube wall. The heat-transfer coefficient is found to increase with the increasing flow rate and pressure and to be independent of the absorbed power. This result indicates that a convective-type mechanism is responsible for the energy transfer.

  18. High-energy lasers by using distributed reflection: A concept

    NASA Technical Reports Server (NTRS)

    Saffren, M. M.

    1975-01-01

    Lasers may be made with higher energy photons than heretofore possible. It has been proposed that vacuum ultraviolet lasing can be obtained by bombarding superfluid helium with electron beam, while coupling acoustic energy into helium to set up standing waves in fluid.

  19. Absolute Measurement of Electron Cloud Density

    SciTech Connect

    Covo, M K; Molvik, A W; Cohen, R H; Friedman, A; Seidl, P A; Logan, G; Bieniosek, F; Baca, D; Vay, J; Orlando, E; Vujic, J L

    2007-06-21

    Beam interaction with background gas and walls produces ubiquitous clouds of stray electrons that frequently limit the performance of particle accelerator and storage rings. Counterintuitively we obtained the electron cloud accumulation by measuring the expelled ions that are originated from the beam-background gas interaction, rather than by measuring electrons that reach the walls. The kinetic ion energy measured with a retarding field analyzer (RFA) maps the depressed beam space-charge potential and provides the dynamic electron cloud density. Clearing electrode current measurements give the static electron cloud background that complements and corroborates with the RFA measurements, providing an absolute measurement of electron cloud density during a 5 {micro}s duration beam pulse in a drift region of the magnetic transport section of the High-Current Experiment (HCX) at LBNL.

  20. Optimum irradiance distribution of concentrated sunlight for photovoltaic energy conversion

    NASA Astrophysics Data System (ADS)

    Benítez, Pablo; Mohedano, Rubén

    1999-04-01

    The irradiance distribution on a concentration photovoltaic cell that produces maximum conversion efficiency has been found with the tools of Variational Calculus. The analysis is two dimensional and can be applied to a comb-like double busbar solar cell illuminated by a line-focus concentrator. The optimum distribution is, in general, nonuniform, and depends on the internal parameters of the solar cell: the higher the contribution of the grid to the global cell series resistance, the lower the uniformity of the optimum irradiance distribution. In practical cases, the efficiency for uniform illumination is close to that of the optimum, but in the latter the irradiance close to the busbar may be noticeable higher than the average.

  1. Electron-energy distribution in silicon under pulsed-laser excitation

    NASA Astrophysics Data System (ADS)

    Bensoussan, M.; Moison, J. M.

    1983-04-01

    By yield and energy-distribution measurements, we identify two photoemission regimes from silicon under nanosecond laser irradiation. At low fluence and high photon energy, two- and three-quantum processes are the main emission mechanisms; effects of initial and intermediate states are the dominant spectral features. At high fluence and low photon energy, thermoemission prevails and is characterized by a Maxwellian distribution with a temperature different from that of the lattice during the excitation pulse.

  2. Measurement Of Kinetic Energy Distribution Of Positive Ions From Electron Induced Dissociation Of Pyrimidine Molecule

    NASA Astrophysics Data System (ADS)

    Milosavljevic, A. R.; Maljkovic, J. B.; Sevic, D.; Cadez, I.; Marinkovic, B. P.

    2010-07-01

    We report preliminary results on measurements of kinetic energy distribution of positive ions formed upon electron induced dissociative ionization of gaseous pyrimidine molecule (C4H4N2). The kinetic energy spectra were recorded without precedent mass/charge analysis, for different incident electron energies (50-250 eV) and different detection angles (40-90) with respect to the incident beam direction. An influence of the residual gas background to the recorded distributions has been investigated.

  3. Model for radial dependence of frequency distributions for energy imparted in nanometer volumes from HZE particles

    NASA Technical Reports Server (NTRS)

    Cucinotta, F. A.; Nikjoo, H.; Goodhead, D. T.; Decillo, J. F. (Principal Investigator)

    2000-01-01

    This paper develops a deterministic model of frequency distributions for energy imparted (total energy deposition) in small volumes similar to DNA molecules from high-energy ions of interest for space radiation protection and cancer therapy. Frequency distributions for energy imparted are useful for considering radiation quality and for modeling biological damage produced by ionizing radiation. For high-energy ions, secondary electron (delta-ray) tracks originating from a primary ion track make dominant contributions to energy deposition events in small volumes. Our method uses the distribution of electrons produced about an ion's path and incorporates results from Monte Carlo simulation of electron tracks to predict frequency distributions for ions, including their dependence on radial distance. The contribution from primary ion events is treated using an impact parameter formalism of spatially restricted linear energy transfer (LET) and energy-transfer straggling. We validate our model by comparing it directly to results from Monte Carlo simulations for proton and alpha-particle tracks. We show for the first time frequency distributions of energy imparted in DNA structures by several high-energy ions such as cosmic-ray iron ions. Our comparison with results from Monte Carlo simulations at low energies indicates the accuracy of the method.

  4. Model for radial dependence of frequency distributions for energy imparted in nanometer volumes from HZE particles.

    PubMed

    Cucinotta, F A; Nikjoo, H; Goodhead, D T

    2000-04-01

    This paper develops a deterministic model of frequency distributions for energy imparted (total energy deposition) in small volumes similar to DNA molecules from high-energy ions of interest for space radiation protection and cancer therapy. Frequency distributions for energy imparted are useful for considering radiation quality and for modeling biological damage produced by ionizing radiation. For high-energy ions, secondary electron (delta-ray) tracks originating from a primary ion track make dominant contributions to energy deposition events in small volumes. Our method uses the distribution of electrons produced about an ion's path and incorporates results from Monte Carlo simulation of electron tracks to predict frequency distributions for ions, including their dependence on radial distance. The contribution from primary ion events is treated using an impact parameter formalism of spatially restricted linear energy transfer (LET) and energy-transfer straggling. We validate our model by comparing it directly to results from Monte Carlo simulations for proton and alpha-particle tracks. We show for the first time frequency distributions of energy imparted in DNA structures by several high-energy ions such as cosmic-ray iron ions. Our comparison with results from Monte Carlo simulations at low energies indicates the accuracy of the method. PMID:10761008

  5. Bayes Node Energy Polynomial Distribution to Improve Routing in Wireless Sensor Network.

    PubMed

    Palanisamy, Thirumoorthy; Krishnasamy, Karthikeyan N

    2015-01-01

    Wireless Sensor Network monitor and control the physical world via large number of small, low-priced sensor nodes. Existing method on Wireless Sensor Network (WSN) presented sensed data communication through continuous data collection resulting in higher delay and energy consumption. To conquer the routing issue and reduce energy drain rate, Bayes Node Energy and Polynomial Distribution (BNEPD) technique is introduced with energy aware routing in the wireless sensor network. The Bayes Node Energy Distribution initially distributes the sensor nodes that detect an object of similar event (i.e., temperature, pressure, flow) into specific regions with the application of Bayes rule. The object detection of similar events is accomplished based on the bayes probabilities and is sent to the sink node resulting in minimizing the energy consumption. Next, the Polynomial Regression Function is applied to the target object of similar events considered for different sensors are combined. They are based on the minimum and maximum value of object events and are transferred to the sink node. Finally, the Poly Distribute algorithm effectively distributes the sensor nodes. The energy efficient routing path for each sensor nodes are created by data aggregation at the sink based on polynomial regression function which reduces the energy drain rate with minimum communication overhead. Experimental performance is evaluated using Dodgers Loop Sensor Data Set from UCI repository. Simulation results show that the proposed distribution algorithm significantly reduce the node energy drain rate and ensure fairness among different users reducing the communication overhead. PMID:26426701

  6. Bayes Node Energy Polynomial Distribution to Improve Routing in Wireless Sensor Network

    PubMed Central

    Palanisamy, Thirumoorthy; Krishnasamy, Karthikeyan N.

    2015-01-01

    Wireless Sensor Network monitor and control the physical world via large number of small, low-priced sensor nodes. Existing method on Wireless Sensor Network (WSN) presented sensed data communication through continuous data collection resulting in higher delay and energy consumption. To conquer the routing issue and reduce energy drain rate, Bayes Node Energy and Polynomial Distribution (BNEPD) technique is introduced with energy aware routing in the wireless sensor network. The Bayes Node Energy Distribution initially distributes the sensor nodes that detect an object of similar event (i.e., temperature, pressure, flow) into specific regions with the application of Bayes rule. The object detection of similar events is accomplished based on the bayes probabilities and is sent to the sink node resulting in minimizing the energy consumption. Next, the Polynomial Regression Function is applied to the target object of similar events considered for different sensors are combined. They are based on the minimum and maximum value of object events and are transferred to the sink node. Finally, the Poly Distribute algorithm effectively distributes the sensor nodes. The energy efficient routing path for each sensor nodes are created by data aggregation at the sink based on polynomial regression function which reduces the energy drain rate with minimum communication overhead. Experimental performance is evaluated using Dodgers Loop Sensor Data Set from UCI repository. Simulation results show that the proposed distribution algorithm significantly reduce the node energy drain rate and ensure fairness among different users reducing the communication overhead. PMID:26426701

  7. The mapping of electronic energy distributions using experimental electron density.

    PubMed

    Tsirelson, Vladimir G

    2002-08-01

    It is demonstrated that the approximate kinetic energy density calculated using the second-order gradient expansion with parameters of the multipole model fitted to experimental structure factors reproduces the main features of this quantity in a molecular or crystal position space. The use of the local virial theorem provides an appropriate derivation of approximate potential energy density and electronic energy density from the experimental (model) electron density and its derivatives. Consideration of these functions is not restricted by the critical points in the electron density and provides a comprehensive characterization of bonding in molecules and crystals. PMID:12149553

  8. Amorphous metal distribution transformers: The energy-efficient alternative

    SciTech Connect

    Garrity, T.F.

    1994-12-31

    Amorphous metal distribution transformers have been commercially available for the past 13 years. During that time, they have realized the promise of exceptionally high core efficiency as compared to silicon steel transformer cores. Utility planners today must consider all options available to meet the requirements of load growth. While additional generation capacity will be added, many demand-side initiatives are being undertaken as complementary programs to generation expansion. The efficiency improvement provided by amorphous metal distribution transformers deserves to be among the demand-side options. The key to understanding the positive impact of amorphous metal transformer efficiency is to consider the aggregate contribution those transformers can make towards demand reduction. It is estimated that distribution transformer core losses comprise at least 1% of the utility`s peak demand. Because core losses are continuous, any significant reduction in their magnitude is of great significance to the planner. This paper describes the system-wide economic contributions amorphous metal distribution transformers can make to a utility and suggests evaluation techniques that can be used. As a conservation tool, the amorphous metal transformer contributes to reduced power plant emissions. Calibration of those emissions reductions is also discussed in the paper.

  9. Radial Flux Distribution of Low-Energy Neutrons.

    ERIC Educational Resources Information Center

    Higinbotham, J.

    1979-01-01

    Describes an experiment designed to illustrate the basic principle involved in the process of moderation of fast neutrons by water, and the monitoring of the low-energy neutron flux using indium as a probe. (GA)

  10. Improved cavity-type absolute total-radiation radiometer

    NASA Technical Reports Server (NTRS)

    Kendall, J. M., Sr.; Plamondon, J. A., Jr.

    1967-01-01

    Conical cavity-type absolute radiometer measures the intensity of radiant energy to an accuracy of one to two percent in a vacuum of ten to the minus fifth torr or lower. There is a uniform response over the ultraviolet, visible, and infrared range, and it requires no calibration or comparison with a radiation standard.

  11. Control of ions energy distribution in dual-frequency magnetron sputtering discharges

    SciTech Connect

    Ye, Chao He, Haijie; Huang, Fupei; Liu, Yi; Wang, Xiangying

    2014-04-15

    The ion energy distributions (IEDs) in the dual-frequency magnetron sputtering discharges were investigated by retarding field energy analyzer. Increasing power ratio of 2 MHz to 13.56 (27.12 or 60) MHz led to the evolution of IEDs from a uni-modal distribution towards a uni-modal distribution with high-energy peak shoulder and a bi-modal distribution. While increasing power ratio of 13.56 MHz to 27.12 MHz and 27.12 MHz to 60 MHz, led to the increase of peak energy. The evolution of IEDs shape and the increase of peak energy are due to the change of ions responding to the average field of high-frequency period towards the instantaneous sheath potential of low-frequency period.

  12. Characterizing the energy distribution of laser-generated relativistic electrons in cone-wire targets

    SciTech Connect

    Sawada, H.; Beg, F. N.; Higginson, D. P.; Ma, T.; Link, A.; Wilks, S. C.; McLean, H. S.; Perez, F.; Patel, P. K.

    2012-10-15

    Transport of relativistic electrons in a solid Cu wire target has been modeled with the implicit hybrid particle-in-cell code LSP to investigate the electron energy distribution and energy coupling from the high-intensity, short-pulse laser to electrons entering to the wire. Experiments were performed on the TITAN laser using a 1.5 mm long Cu wire attached to a Au cone tip at the laser intensity of 1 Multiplication-Sign 10{sup 20} W/cm{sup 2} which was irradiated into the cone. The simulated Cu K{alpha} wire profile and yields matched the measurements using a two-temperature energy distribution. These modeling results show that the cold component of the energy spectrum can be determined with {+-}100 keV accuracy from the fit to the initial experimental fall-off of the K{alpha} emission while the simulated profiles were relatively insensitive to the hotter component of the electron distribution (>4 MeV). The slope of measured escaped electrons was used to determine the hotter temperature. Using exponential energy distributions, the laser-to-electron-in-wire coupling efficiencies inferred from the fits decreased from 3.4% to 1.5% as the prepulse energy increases up to 1 J. The comparison of the energy couplings using the exponential and Relativistic Maxwellian distribution functions showed that the energy inferred in the cold component is independent of the type of the distribution function.

  13. Model Etch Profiles for Ion Energy Distribution Functions in an Inductively Coupled Plasma Reactor

    SciTech Connect

    Abraham-Shrauner, B.; Chen, W.; Woodworth, J.R.

    1998-12-14

    Rectangular trench profiles are modeled with analytic etch rates determined from measured ion distribution functions. The pattern transfer step for this plasma etch is for trilayer lithography. Argon and chlorine angular ion energy distribution functions measured by a spherical collector ring analyzer are fit to a sum of drifting Maxwellian velocity distribution functions with anisotropic temperatures. The fit of the model ion distribution functions by a simulated annealing optimization procedure converges adequately for only two drifting Maxwellians. The etch rates are proportional to analytic expressions for the ion energy flux. Numerical computation of the etch profiles by integration of the characteristic equations for profile points and connection of the profiles points is efficient.

  14. Energy distributions and radiation transport in uranium plasmas

    NASA Technical Reports Server (NTRS)

    Miley, G. H.; Bathke, C.; Maceda, E.; Choi, C.

    1976-01-01

    An approximate analytic model, based on continuous electron slowing, has been used for survey calculations. Where more accuracy is required, a Monte Carlo technique is used which combines an analytic representation of Coulombic collisions with a random walk treatment of inelastic collisions. The calculated electron distributions have been incorporated into another code that evaluates both the excited atomic state densities within the plasma and the radiative flux emitted from the plasma.

  15. Stepanian's star - The energy distribution reveals a nontypical cataclysmic variable

    NASA Technical Reports Server (NTRS)

    Szkody, P.

    1981-01-01

    Einstein, IUE, optical multichannel spectrophotometry, and IR observations of Stepanian's star are discussed in terms of other known cataclysmics. While the X-ray flux and IUE emission-line data are similar to that of dwarf novae, the total continuum flux distribution from uv-IR is cooler (peaking near a 10,000 K blackbody) and is unlike either a stellar component or a classic steady-state disk. The IR data show no evidence for a late-type component.

  16. Anomalous broadening of energy distributions in photoemitted electron beams

    NASA Astrophysics Data System (ADS)

    Guidi, Vincenzo

    1996-06-01

    Photoemission is widely used to generate electron beams with an energy spread lower than by thermoemission. However, when a photocathode is illuminated by a multimode laser this feature is lost and an electron beam with several eV of energy spread is produced. We have developed an explanation for this anomalous behavior pointing out its origin in the combined effect of charge relaxation, taking place within the beam, together with the modulation of the laser power imposed by laser modes. The model permits a correct interpretation overall experimental evidences.

  17. Gyrokinetic Statistical Absolute Equilibrium and Turbulence

    SciTech Connect

    Jian-Zhou Zhu and Gregory W. Hammett

    2011-01-10

    A paradigm based on the absolute equilibrium of Galerkin-truncated inviscid systems to aid in understanding turbulence [T.-D. Lee, "On some statistical properties of hydrodynamical and magnetohydrodynamical fields," Q. Appl. Math. 10, 69 (1952)] is taken to study gyrokinetic plasma turbulence: A finite set of Fourier modes of the collisionless gyrokinetic equations are kept and the statistical equilibria are calculated; possible implications for plasma turbulence in various situations are discussed. For the case of two spatial and one velocity dimension, in the calculation with discretization also of velocity v with N grid points (where N + 1 quantities are conserved, corresponding to an energy invariant and N entropy-related invariants), the negative temperature states, corresponding to the condensation of the generalized energy into the lowest modes, are found. This indicates a generic feature of inverse energy cascade. Comparisons are made with some classical results, such as those of Charney-Hasegawa-Mima in the cold-ion limit. There is a universal shape for statistical equilibrium of gyrokinetics in three spatial and two velocity dimensions with just one conserved quantity. Possible physical relevance to turbulence, such as ITG zonal flows, and to a critical balance hypothesis are also discussed.

  18. Absolute decay width measurements in 16O

    NASA Astrophysics Data System (ADS)

    Wheldon, C.; Ashwood, N. I.; Barr, M.; Curtis, N.; Freer, M.; Kokalova, Tz; Malcolm, J. D.; Spencer, S. J.; Ziman, V. A.; Faestermann, Th; Krücken, R.; Wirth, H.-F.; Hertenberger, R.; Lutter, R.; Bergmaier, A.

    2012-09-01

    The reaction 126C(63Li, d)168O* at a 6Li bombarding energy of 42 MeV has been used to populate excited states in 16O. The deuteron ejectiles were measured using the high-resolution Munich Q3D spectrograph. A large-acceptance silicon-strip detector array was used to register the recoil and break-up products. This complete kinematic set-up has enabled absolute α-decay widths to be measured with high-resolution in the 13.9 to 15.9 MeV excitation energy regime in 16O; many for the first time. This energy region spans the 14.4 MeV four-α breakup threshold. Monte-Carlo simulations of the detector geometry and break-up processes yield detection efficiencies for the two dominant decay modes of 40% and 37% for the α+12C(g.s.) and a+12C(2+1) break-up channels respectively.

  19. Distributed Power Flow Control: Distributed Power Flow Control using Smart Wires for Energy Routing

    SciTech Connect

    2012-04-24

    GENI Project: Smart Wire Grid is developing a solution for controlling power flow within the electric grid to better manage unused and overall transmission capacity. The 300,000 miles of high-voltage transmission line in the U.S. today are congested and inefficient, with only around 50% of all transmission capacity utilized at any given time. Increased consumer demand should be met in part with more efficient and an economical power flow. Smart Wire Grid’s devices clamp onto existing transmission lines and control the flow of power within—much like how internet routers help allocate bandwidth throughout the web. Smart wires could support greater use of renewable energy by providing more consistent control over how that energy is routed within the grid on a real-time basis. This would lessen the concerns surrounding the grid’s inability to effectively store intermittent energy from renewables for later use.

  20. Improving HST Pointing & Absolute Astrometry

    NASA Astrophysics Data System (ADS)

    Lallo, Matthew; Nelan, E.; Kimmer, E.; Cox, C.; Casertano, S.

    2007-05-01

    Accurate absolute astrometry is becoming increasingly important in an era of multi-mission archives and virtual observatories. Hubble Space Telescope's (HST's) Guidestar Catalog II (GSC2) has reduced coordinate error to around 0.25 arcsecond, a factor 2 or more compared with GSC1. With this reduced catalog error, special attention must be given to calibrate and maintain the Fine Guidance Sensors (FGSs) and Science Instruments (SIs) alignments in HST to a level well below this in order to ensure that the accuracy of science product's astrometry keywords and target positioning are limited only by the catalog errors. After HST Servicing Mission 4, such calibrations' improvement in "blind" pointing accuracy will allow for more efficient COS acquisitions. Multiple SIs and FGSs each have their own footprints in the spatially shared HST focal plane. It is the small changes over time in primarily the whole-body positions & orientations of these instruments & guiders relative to one another that is addressed by this work. We describe the HST Cycle 15 program CAL/OTA 11021 which, along with future variants of it, determines and maintains positions and orientations of the SIs and FGSs to better than 50 milli- arcseconds and 0.04 to 0.004 degrees of roll, putting errors associated with the alignment sufficiently below GSC2 errors. We present recent alignment results and assess their errors, illustrate trends, and describe where and how the observer sees benefit from these calibrations when using HST.

  1. Absolute oral bioavailability of ciprofloxacin.

    PubMed

    Drusano, G L; Standiford, H C; Plaisance, K; Forrest, A; Leslie, J; Caldwell, J

    1986-09-01

    We evaluated the absolute bioavailability of ciprofloxacin, a new quinoline carboxylic acid, in 12 healthy male volunteers. Doses of 200 mg were given to each of the volunteers in a randomized, crossover manner 1 week apart orally and as a 10-min intravenous infusion. Half-lives (mean +/- standard deviation) for the intravenous and oral administration arms were 4.2 +/- 0.77 and 4.11 +/- 0.74 h, respectively. The serum clearance rate averaged 28.5 +/- 4.7 liters/h per 1.73 m2 for the intravenous administration arm. The renal clearance rate accounted for approximately 60% of the corresponding serum clearance rate and was 16.9 +/- 3.0 liters/h per 1.73 m2 for the intravenous arm and 17.0 +/- 2.86 liters/h per 1.73 m2 for the oral administration arm. Absorption was rapid, with peak concentrations in serum occurring at 0.71 +/- 0.15 h. Bioavailability, defined as the ratio of the area under the curve from 0 h to infinity for the oral to the intravenous dose, was 69 +/- 7%. We conclude that ciprofloxacin is rapidly absorbed and reliably bioavailable in these healthy volunteers. Further studies with ciprofloxacin should be undertaken in target patient populations under actual clinical circumstances. PMID:3777908

  2. Site energy distribution analysis of Cu (Ⅱ) adsorption on sediments and residues by sequential extraction method.

    PubMed

    Jin, Qiang; Yang, Yan; Dong, Xianbin; Fang, Jimin

    2016-01-01

    Many models (e.g., Langmuir model, Freundlich model and surface complexation model) have been successfully used to explain the mechanism of metal ion adsorption on the pure mineral materials. These materials usually have a homogeneous surface where all sites have the same adsorption energies. However, it's hardly appropriate for such models to describe the adsorption on heterogeneous surfaces (e.g., sediment surface), site energy distribution analysis can be to. In the present study, the site energy distribution analysis was used to describe the surface properties and adsorption behavior of the non-residual and residual components extracted from the natural aquatic sediment samples. The residues were prepared "in-situ" by using the sequential extraction procedure. The present study is intended to investigate the roles of different components and the change of site energy distribution at different temperatures of the sediment samples in controlling Cu (Ⅱ) adsorption. The results of the site energy distribution analysis indicated firstly, that the sorption sites of iron/manganese hydrous oxides (IMHO) and organic matter (OM) have higher energy. Secondly, light fraction (LF) and carbonates have little influence on site energy distribution. Finally, there was increase in site energies with the increase of temperature. Specially, low temperature (5 °C) significantly influenced the site energies of IMHO and OM, and also had obvious effect on the energy distribution of the sediments after removing target components. The site energy distribution analysis proved to be a useful method for us to further understand the energetic characteristics of sediment in comparison with those previously obtained. PMID:26552542

  3. Fuzzy Performance between Surface Fitting and Energy Distribution in Turbulence Runner

    PubMed Central

    Liang, Zhongwei; Liu, Xiaochu; Ye, Bangyan; Brauwer, Richard Kars

    2012-01-01

    Because the application of surface fitting algorithms exerts a considerable fuzzy influence on the mathematical features of kinetic energy distribution, their relation mechanism in different external conditional parameters must be quantitatively analyzed. Through determining the kinetic energy value of each selected representative position coordinate point by calculating kinetic energy parameters, several typical algorithms of complicated surface fitting are applied for constructing microkinetic energy distribution surface models in the objective turbulence runner with those obtained kinetic energy values. On the base of calculating the newly proposed mathematical features, we construct fuzzy evaluation data sequence and present a new three-dimensional fuzzy quantitative evaluation method; then the value change tendencies of kinetic energy distribution surface features can be clearly quantified, and the fuzzy performance mechanism discipline between the performance results of surface fitting algorithms, the spatial features of turbulence kinetic energy distribution surface, and their respective environmental parameter conditions can be quantitatively analyzed in detail, which results in the acquirement of final conclusions concerning the inherent turbulence kinetic energy distribution performance mechanism and its mathematical relation. A further turbulence energy quantitative study can be ensured. PMID:23213287

  4. Absolute Instability in Coupled-Cavity TWTs

    NASA Astrophysics Data System (ADS)

    Hung, D. M. H.; Rittersdorf, I. M.; Zhang, Peng; Lau, Y. Y.; Simon, D. H.; Gilgenbach, R. M.; Chernin, D.; Antonsen, T. M., Jr.

    2014-10-01

    This paper will present results of our analysis of absolute instability in a coupled-cavity traveling wave tube (TWT). The structure mode at the lower and upper band edges are respectively approximated by a hyperbola in the (omega, k) plane. When the Briggs-Bers criterion is applied, a threshold current for onset of absolute instability is observed at the upper band edge, but not the lower band edge. The nonexistence of absolute instability at the lower band edge is mathematically similar to the nonexistence of absolute instability that we recently demonstrated for a dielectric TWT. The existence of absolute instability at the upper band edge is mathematically similar to the existence of absolute instability in a gyroton traveling wave amplifier. These interesting observations will be discussed, and the practical implications will be explored. This work was supported by AFOSR, ONR, and L-3 Communications Electron Devices.

  5. HST Stellar Standards with 1% Accuracy in Absolute Flux

    NASA Astrophysics Data System (ADS)

    Bohlin, R. C.

    2007-04-01

    Free of any atmospheric contamination, the {Hubble Space Telescope} provides the best available spectrophotometry from the far-UV to the near-IR for stars as faint as V˜16. The HST CALSPEC standard star network is based on three standard candles: the hot, pure hydrogen white dwarf (WD) stars G 191B2B, GD 153, and GD 71, which have Hubeny NLTE flux calculations that require the atomic physics for only one atom. These model flux distributions are normalized to the absolute flux for Vega of 3.46×10-9 erg cm-2 s-1 Å-1 at 5556 Å using precise Landolt V band photometry and the V bandpass function corrected for atmospheric transmission by M. Cohen. The three primary WD standards provide absolute flux calibrations for FOS, STIS and NICMOS spectrophotometry from these instruments on the HST. About 32 stellar spectral energy distributions (SEDs) have been constructed with a primary pedigree from the STIS data, which extends from 1150 Å for the hot stars to a long wavelength limit of 1 μm. NICMOS grism spectrophotometry provides an extension to 1.9 μm in the IR for 17 of the HST standards and longward to 2.5 μm for a few of the brighter stars. Included among these HST standards are Vega, the Sloan standard BD+17 4708, three bright solar analog candidates, three cool stars of type M or later, and five hot WDs. In addition, four K giants and four main sequence A-stars have NICMOS spectrophotometry from 0.8-2.5 μm. The WD fluxes are compared to their modeled SEDs and demonstrate an internal precision of 1-2%, while the A-stars agree with the Cohen IR fluxes to ˜2%. Three solar analog candidate stars differ from the solar spectrum by up to 10% in the region of heavy line blanketing from 3000-4000 Å and show differences in shape of ˜5% in the IR around 1.8 μm.

  6. Energy, ecology and the distribution of microbial life

    PubMed Central

    Macalady, Jennifer L.; Hamilton, Trinity L.; Grettenberger, Christen L.; Jones, Daniel S.; Tsao, Leah E.; Burgos, William D.

    2013-01-01

    Mechanisms that govern the coexistence of multiple biological species have been studied intensively by ecologists since the turn of the nineteenth century. Microbial ecologists in the meantime have faced many fundamental challenges, such as the lack of an ecologically coherent species definition, lack of adequate methods for evaluating population sizes and community composition in nature, and enormous taxonomic and functional diversity. The accessibility of powerful, culture-independent molecular microbiology methods offers an opportunity to close the gap between microbial science and the main stream of ecological theory, with the promise of new insights and tools needed to meet the grand challenges humans face as planetary engineers and galactic explorers. We focus specifically on resources related to energy metabolism because of their direct links to elemental cycling in the Earth's history, engineering applications and astrobiology. To what extent does the availability of energy resources structure microbial communities in nature? Our recent work on sulfur- and iron-oxidizing autotrophs suggests that apparently subtle variations in the concentration ratios of external electron donors and acceptors select for different microbial populations. We show that quantitative knowledge of microbial energy niches (population-specific patterns of energy resource use) can be used to predict variations in the abundance of specific taxa in microbial communities. Furthermore, we propose that resource ratio theory applied to micro-organisms will provide a useful framework for identifying how environmental communities are organized in space and time. PMID:23754819

  7. Analysis of swarm coefficients in a gas for bi-modal electron energy distribution model

    NASA Astrophysics Data System (ADS)

    Govinda-Raju, Gorur

    2015-03-01

    Cross sections for collision between electrons and neutrals in a gas discharge are essential for theoretical and computational developments. They are also required to interpret and analyze the results of experimental studies on swarm parameters namely drift velocity, characteristic energy, and ionization and attachment coefficients. The cross sections and swarm coefficients are interconnected through the most important electron energy distribution function. The traditional method of solving the Boltzmann equation numerically yields the required distribution (EEDF). However there are many situations where a simpler approach is desirable for deriving the energy distribution analytically. Energy distribution in non-uniform electric fields, in crossed electric and magnetic fields, breakdown in mixtures of gases for electrical power or plasma applications, calculation of longitudinal diffusion coefficients are examples. In other studies the swarm parameters are employed to derive the cross sections in an unfolding procedure that also involves the energy distribution function. Application of Boltzmann solution method, though more rigorous, consumes enormous efforts in time and technical expertise. In an attempt to provide a simpler method the present author has previously suggested a bimodal electron energy distribution in gases. In this paper the author has generalized the idea of bi-modal energy distribution by considering a model gas with representative cross sections and adopted numerical methods for greater accuracy. The parameters considered are the nature of the two distributions, their relative ratio, and the dependence of cross sections on electron energy. A new method for determining the combination of distributions has been shown to be adequate for calculation of swarm parameters. The results for argon are shown to yield very good agreement with available experimental and theoretical values.

  8. Near-equipartition Jets with Log-parabola Electron Energy Distribution and the Blazar Spectral-index Diagrams

    NASA Astrophysics Data System (ADS)

    Dermer, Charles D.; Yan, Dahai; Zhang, Li; Finke, Justin D.; Lott, Benoit

    2015-08-01

    Fermi-LAT analyses show that the γ-ray photon spectral indices {{{Γ }}}γ of a large sample of blazars correlate with the ν {F}ν peak synchrotron frequency {ν }s according to the relation {{{Γ }}}γ =d-k{log} {ν }s. The same function, with different constants d and k, also describes the relationship between {{{Γ }}}γ and peak Compton frequency {ν }{{C}}. This behavior is derived analytically using an equipartition blazar model with a log-parabola description of the electron energy distribution (EED). In the Thomson regime, k={k}{EC}=3b/4 for external Compton (EC) processes and k={k}{SSC}=9b/16 for synchrotron self-Compton (SSC) processes, where b is the log-parabola width parameter of the EED. The BL Lac object Mrk 501 is fit with a synchrotron/SSC model given by the log-parabola EED, and is best fit away from equipartition. Corrections are made to the spectral-index diagrams for a low-energy power-law EED and departures from equipartition, as constrained by absolute jet power. Analytic expressions are compared with numerical values derived from self-Compton and EC scattered γ-ray spectra from Lyα broad-line region and IR target photons. The {{{Γ }}}γ versus {ν }s behavior in the model depends strongly on b, with progressively and predictably weaker dependences on γ-ray detection range, variability time, and isotropic γ-ray luminosity. Implications for blazar unification and blazars as ultra-high energy cosmic-ray sources are discussed. Arguments by Ghisellini et al. that the jet power exceeds the accretion luminosity depend on the doubtful assumption that we are viewing at the Doppler angle.

  9. Documentation for the machine-readable version of the Absolute Calibration of Stellar Spectrophotometry

    NASA Technical Reports Server (NTRS)

    Warren, W. H., Jr.

    1982-01-01

    The machine-readable data file of The Absolute Calibration of Stellar Spectrophotometry as distributed by the Astronomical Data Center is described. The data file contains the absolute fluxes for 16 stars published in Tables 1 and 2 of Johnson (1980). The absolute calibrations were accomplished by combining the 13-color photometry calibrations of Johnson and Mitchell (1975) with spectra obtained with a Michelson spectrophotometer and covering the wavelength range 4000 to 10300 A (Johnson 1977). The agreement between this absolute calibration and another recent one based upon data for a Lyr and 109 Vir by Tug, White and Lockwood (1977) is shown by Johnson (1980) to be quite good.

  10. Absolute luminosity measurements with the LHCb detector at the LHC

    NASA Astrophysics Data System (ADS)

    LHCb Collaboration

    2012-01-01

    Absolute luminosity measurements are of general interest for colliding-beam experiments at storage rings. These measurements are necessary to determine the absolute cross-sections of reaction processes and are valuable to quantify the performance of the accelerator. Using data taken in 2010, LHCb has applied two methods to determine the absolute scale of its luminosity measurements for proton-proton collisions at the LHC with a centre-of-mass energy of 7 TeV. In addition to the classic ``van der Meer scan'' method a novel technique has been developed which makes use of direct imaging of the individual beams using beam-gas and beam-beam interactions. This beam imaging method is made possible by the high resolution of the LHCb vertex detector and the close proximity of the detector to the beams, and allows beam parameters such as positions, angles and widths to be determined. The results of the two methods have comparable precision and are in good agreement. Combining the two methods, an overal precision of 3.5% in the absolute luminosity determination is reached. The techniques used to transport the absolute luminosity calibration to the full 2010 data-taking period are presented.

  11. Distributed Energy Resources and Dynamic Microgrid: An Integrated Assessment

    NASA Astrophysics Data System (ADS)

    Shang, Duo Rick

    The overall goal of this thesis is to improve understanding in terms of the benefit of DERs to both utility and to electricity end-users when integrated in power distribution system. To achieve this goal, a series of two studies was conducted to assess the value of DERs when integrated with new power paradigms. First, the arbitrage value of DERs was examined in markets with time-variant electricity pricing rates (e.g., time of use, real time pricing) under a smart grid distribution paradigm. This study uses a stochastic optimization model to estimate the potential profit from electricity price arbitrage over a five-year period. The optimization process involves two types of PHEVs (PHEV-10, and PHEV-40) under three scenarios with different assumptions on technology performance, electricity market and PHEV owner types. The simulation results indicate that expected arbitrage profit is not a viable option to engage PHEVs in dispatching and in providing ancillary services without more favorable policy and PHEV battery technologies. Subsidy or change in electricity tariff or both are needed. Second, it examined the concept of dynamic microgrid as a measure to improve distribution resilience, and estimates the prices of this emerging service. An economic load dispatch (ELD) model is developed to estimate the market-clearing price in a hypothetical community with single bid auction electricity market. The results show that the electricity market clearing price on the dynamic microgrid is predominantly decided by power output and cost of electricity of each type of DGs. At circumstances where CHP is the only source, the electricity market clearing price in the island is even cheaper than the on-grid electricity price at normal times. Integration of PHEVs in the dynamic microgrid will increase electricity market clearing prices. It demonstrates that dynamic microgrid is an economically viable alternative to enhance grid resilience.

  12. Assessment of grid-friendly collective optimization framework for distributed energy resources

    SciTech Connect

    Pensini, Alessandro; Robinson, Matthew; Heine, Nicholas; Stadler, Michael; Mammoli, Andrea

    2015-11-04

    Distributed energy resources have the potential to provide services to facilities and buildings at lower cost and environmental impact in comparison to traditional electric-gridonly services. The reduced cost could result from a combination of higher system efficiency and exploitation of electricity tariff structures. Traditionally, electricity tariffs are designed to encourage the use of ‘off peak’ power and discourage the use of ‘onpeak’ power, although recent developments in renewable energy resources and distributed generation systems (such as their increasing levels of penetration and their increased controllability) are resulting in pressures to adopt tariffs of increasing complexity. Independently of the tariff structure, more or less sophisticated methods exist that allow distributed energy resources to take advantage of such tariffs, ranging from simple pre-planned schedules to Software-as-a-Service schedule optimization tools. However, as the penetration of distributed energy resources increases, there is an increasing chance of a ‘tragedy of the commons’ mechanism taking place, where taking advantage of tariffs for local benefit can ultimately result in degradation of service and higher energy costs for all. In this work, we use a scheduling optimization tool, in combination with a power distribution system simulator, to investigate techniques that could mitigate the deleterious effect of ‘selfish’ optimization, so that the high-penetration use of distributed energy resources to reduce operating costs remains advantageous while the quality of service and overall energy cost to the community is not affected.

  13. Absolute negative mobility of interacting Brownian particles

    NASA Astrophysics Data System (ADS)

    Ou, Ya-li; Hu, Cai-tian; Wu, Jian-chun; Ai, Bao-quan

    2015-12-01

    Transport of interacting Brownian particles in a periodic potential is investigated in the presence of an ac force and a dc force. From Brownian dynamic simulations, we find that both the interaction between particles and the thermal fluctuations play key roles in the absolute negative mobility (the particle noisily moves backwards against a small constant bias). When no the interaction acts, there is only one region where the absolute negative mobility occurs. In the presence of the interaction, the absolute negative mobility may appear in multiple regions. The weak interaction can be helpful for the absolute negative mobility, while the strong interaction has a destructive impact on it.

  14. Distributed SUSY breaking: dark energy, Newton's law and the LHC

    NASA Astrophysics Data System (ADS)

    Burgess, C. P.; van Nierop, L.; Williams, M.

    2014-07-01

    We identify the underlying symmetry mechanism that suppresses the low-energy effective 4D cosmological constant within some 6D supergravity models, generically leading to results suppressed by powers of the KK scale, m {/K K 2}, relative to the much larger size, m 4, associated with mass- m particles localized in these models on codimension-2 branes. These models are examples for which the local conditions for unbroken supersymmetry can be satisfied locally everywhere within the extra dimensions, but are obstructed only by global conditions like flux quantization or by the mutual inconsistency of the boundary conditions required at the various branes. Consequently quantities (like vacuum energies) forbidden by supersymmetry cannot become nonzero until wavelengths of order the KK scale are integrated out, since only such long wavelength modes can see the entire space and so `know' that supersymmetry has broken. We verify these arguments by extending earlier rugby-ball calculations of one-loop vacuum energies within these models to more general pairs of branes within two warped extra dimensions. For the Standard Model confined to one of two otherwise identical branes, the predicted effective 4D vacuum energy density is of order ρ vac ⋍ C( mM g /4 πM p )4 = C(5 .6 × 10-5 eV)4, where M g ≳ 10 TeV (corresponding to extra-dimensional size r ≲ 1 μm) and M p = 2 .44 × 1018 GeV are the 6D and 4D rationalized Planck scales, and m is the heaviest brane-localized particle. (For numerical purposes we take m to be the top-quark mass and take M g as small as possible, consistent with energy-loss bounds from supernovae.) C is a constant depending on the details of the bulk spectrum, which could easily be of order 500 for each of hundreds of fields in the bulk. The value C ˜ 6 × 106 would give the observed Dark Energy density.

  15. Effects of energy distribution of interface traps on recombination dc current-voltage line shape

    NASA Astrophysics Data System (ADS)

    Chen, Zuhui; Jie, Bin B.; Sah, Chih-Tang

    2006-12-01

    The effects of energy distributions of Si /SiO2 interface traps in the energy gap of oxidized silicon on the current versus voltage line shape of the electron-hole recombination current are analyzed using the steady-state Shockley-Read-Hall kinetics. Slater's [Insulators, Semiconductors and Metals; Quantum Theory of Molecules and Solids (McGraw-Hill, New York, 1967)] localized bulk perturbation theory applied by us to the interface anticipates U-shaped energy distributions of the density of neutral electron and hole interface traps from random variations of the Si:Si and Si:O bond angles and lengths. Conservation in dissipative transition energy anticipates the rate of electron capture into neutral electron trap to be faster for electron trap energy levels nearer the conduction band edge, and similarly, the rate of hole capture into neutral hole trap to be faster for hole trap energy levels nearer the valence band edge. Line shape broadening is analyzed for discrete and U-shaped energy distributions of interface trap energy levels. The broadened line shapes observed in past experiments, previously attributed to spatial variations of surface dopant impurity concentrations, could also arise from energy distributions of interface trap energy levels.

  16. FEL and Optical Klystron Gain for an Electron Beam with Oscillatory Energy Distribution

    SciTech Connect

    Stupakov, G.; Ding, Y.; Huang, Z.; /SLAC

    2009-12-09

    If the energy spread of a beam is larger then the Pierce parameter, the FEL gain length increases dramatically and the FEL output gets suppressed. We show that if the energy distribution of such a beam is made oscillatory on a small scale, the gain length can be considerably decreased. Such an oscillatory energy distribution is generated by first modulating the beam energy with a laser via the mechanism of inverse FEL, and then sending it through a strong chicane. We show that this approach also works for the optical klystron enhancement scheme. Our analytical results are corroborated by numerical simulations.

  17. Electron energy distributions in uranium helium mixtures. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Makowski, M. A.

    1977-01-01

    The high energy portion of the electron energy distribution for mixtures of uranium and helium at 1 atm, 5000 K, and a neutron flux of 2x10 to the 12th power/sq cm-sec have been calculated. The addition of He improves the heat transport characteristics of the plasma and has the feature that the He energy levels lie in the high energy portion of the electron distribution, potentially allowing non maxwellian excitation. It is concluded, however, that the resulting reaction rates are marginal relative to achieving inversion in He.

  18. Measurement of the B hadron energy distribution in Z0 decays

    NASA Astrophysics Data System (ADS)

    Abe, K.; Abe, K.; Akagi, T.; Allen, N. J.; Ash, W. W.; Aston, D.; Baird, K. G.; Baltay, C.; Band, H. R.; Barakat, M. B.; Baranko, G.; Bardon, O.; Barklow, T. L.; Bashindzhagyan, G. L.; Bazarko, A. O.; Ben-David, R.; Benvenuti, A. C.; Bilei, G. M.; Bisello, D.; Blaylock, G.; Bogart, J. R.; Bolen, B.; Bolton, T.; Bower, G. R.; Brau, J. E.; Breidenbach, M.; Bugg, W. M.; Burke, D.; Burnett, T. H.; Burrows, P. N.; Busza, W.; Calcaterra, A.; Caldwell, D. O.; Calloway, D.; Camanzi, B.; Carpinelli, M.; Cassell, R.; Castaldi, R.; Castro, A.; Cavalli-Sforza, M.; Chou, A.; Church, E.; Cohn, H. O.; Coller, J. A.; Cook, V.; Cotton, R.; Cowan, R. F.; Coyne, D. G.; Crawford, G.; D'Oliveira, A.; Damerell, C. J.; Daoudi, M.; de Groot, N.; de Sangro, R.; dell'Orso, R.; Dervan, P. J.; Dima, M.; Dong, D. N.; Du, P. Y.; Dubois, R.; Einsenstein, B. I.; Elia, R.; Etzion, E.; Fahey, S.; Falciai, D.; Fan, C.; Fernandez, J. P.; Fero, M. J.; Frey, R.; Gillman, T.; Gladding, G.; Gonzalez, S.; Hart, E. L.; Harton, J. L.; Hasan, A.; Hasegawa, Y.; Hasuko, K.; Hedges, S. J.; Hertzbach, S. S.; Hildreth, M. D.; Huber, J.; Huffer, M. E.; Hughes, E. W.; Hwang, H.; Iwasaki, Y.; Jackson, D. J.; Jacques, P.; Jaros, J. A.; Jiang, Z. Y.; Johnson, A. S.; Johnson, J. R.; Johnson, R. A.; Junk, T.; Kajikawa, R.; Kalelkar, M.; Kang, H. J.; Karliner, I.; Kawahara, H.; Kendall, H. W.; Kim, Y. D.; King, M. E.; King, R.; Kofler, R. R.; Krishna, N. M.; Kroeger, R. S.; Labs, J. F.; Langston, M.; Lath, A.; Lauber, J. A.; Leith, D. W.; Lia, V.; Liu, M. X.; Liu, X.; Loreti, M.; Lu, A.; Lynch, H. L.; Ma, J.; Mancinelli, G.; Manly, S.; Mantovani, G.; Markiewicz, T. W.; Maruyama, T.; Masuda, H.; Mazzucato, E.; McKemey, A. K.; Meadows, B. T.; Messner, R.; Mockett, P. M.; Moffeit, K. C.; Moore, T. B.; Muller, D.; Nagamine, T.; Narita, S.; Nauenberg, U.; Neal, H.; Nussbaum, M.; Ohnishi, Y.; Oishi, N.; Onoprienko, D.; Osborne, L. S.; Panvini, R. S.; Park, C. H.; Park, H.; Pavel, T. J.; Peruzzi, I.; Piccolo, M.; Piemontese, L.; Pieroni, E.; Pitts, K. T.; Plano, R. J.; Prepost, R.; Prescott, C. Y.; Punkar, G. D.; Quigley, J.; Ratcliff, B. N.; Reeves, T. W.; Reidy, J.; Reinertsen, P. L.; Rensing, P. E.; Rochester, L. S.; Rowson, P. C.; Russell, J. J.; Saxton, O. H.; Schalk, T.; Schindler, R. H.; Schumm, B. A.; Schwiening, J.; Sen, S.; Serbo, V. V.; Shaevitz, M. H.; Shank, J. T.; Shapiro, G.; Sherden, D. J.; Shmakov, K. D.; Simopoulos, C.; Sinev, N. B.; Smith, S. R.; Smy, M. B.; Snyder, J. A.; Staengle, H.; Stamer, P.; Steiner, H.; Steiner, R.; Strauss, M. G.; Su, D.; Suekane, F.; Sugiyama, A.; Suzuki, S.; Swartz, M.; Szumilo, A.; Takahashi, T.; Taylor, F. E.; Torrence, E.; Trandafir, A. I.; Turk, J. D.; Usher, T.; Va'Vra, J.; Vannini, C.; Vella, E.; Venuti, J. P.; Verdier, R.; Verdini, P. G.; Wagner, D. L.; Wagner, S. R.; Waite, A. P.; Watts, S. J.; Weidemann, A. W.; Weiss, E. R.; Whitaker, J. S.; White, S. L.; Wickens, F. J.; Williams, D. C.; Williams, S. H.; Willocq, S.; Wilson, R. J.; Wisniewski, W. J.; Woods, M.; Word, G. B.; Wyss, J.; Yamamoto, R. K.; Yamartino, J. M.; Yang, X.; Yashima, J.; Yellin, S. J.; Young, C. C.; Yuta, H.; Zapalac, G.; Zdarko, R. W.; Zhou, J.

    1997-11-01

    We have measured the B hadron energy distribution in Z0 decays using a sample of semileptonic B decays recorded in the SLD experiment at SLAC. The energy of each tagged B hadron was reconstructed using information from the lepton and a partially reconstructed charm-decay vertex. We compared the scaled energy distribution with several models of heavy quark fragmentation. The average scaled energy of primary B hadrons was found to be =0.716+/-0.011(stat)+0.021-0.022(syst).

  19. An Application of the Market-Oriented Programming to Energy Trading Decision Method in Distributed Energy Management Systems

    NASA Astrophysics Data System (ADS)

    Yakire, Koji; Miyamoto, Toshiyuki; Kumagai, Sadatoshi; Mori, Kazuyuki; Kitamura, Shoichi; Yamamoto, Takaya

    A control of CO2 emissions which is the main factor of global warming is one of the most important problems in the 21st century about preservation of earth environment. Therefore, efficient supply and use of energy are indispensable. We have proposed distributed energy management systems (DEMSs), where we are to obtain optimal plans that minimize both of costs and CO2 emissions through electrical and thermal energy trading. A DEMS consists of the plural entities that seek their own economic profits. In this paper, we propose a trading method that gives competitive equilibrium resource distribution by applying the market-oriented programming (MOP) to DEMSs.

  20. Energy dependence of mass, charge, isotopic, and energy distributions in neutron-induced fission of 235U and 239Pu

    NASA Astrophysics Data System (ADS)

    Pasca, H.; Andreev, A. V.; Adamian, G. G.; Antonenko, N. V.; Kim, Y.

    2016-05-01

    The mass, charge, isotopic, and kinetic-energy distributions of fission fragments are studied within an improved scission-point statistical model in the reactions 235U+n and 239Pu+n at different energies of the incident neutron. The charge and mass distributions of the electromagnetic- and neutron-induced fission of 214,218Ra, 230,232,238U are also shown. The available experimental data are well reproduced and the energy-dependencies of the observable characteristics of fission are predicted for future experiments.

  1. 5 to 160 keV continuous-wave x-ray spectral energy distribution and energy flux density measurements

    SciTech Connect

    Tallon, R.W.; Koller, D.C.; Pelzl, R.M.; Pugh, R.D.; Bellem, R.D. . Microelectronics and Photonics Research Branch)

    1994-12-01

    In 1991, the USAF Phillips Laboratory Microelectronics and Photonics Research Branch installed a low energy x-ray facility (LEXR) for use in microelectronics radiation-effects analysis and research. Techniques developed for measuring the x-ray spectral energy distribution (differential intensity) from a tungsten-target bremsstrahlung x-ray source are reported. Spectra with end-point energies ranging from 20 to 160 keV were recorded. A separate effort to calibrate the dosimetry for the Phillips Laboratory low-energy x-ray facility established a need to know the spectral energy distributions at some point within the facility (previous calibration efforts had relies on spectra obtained from computer simulations). It was discovered that the primary discrepancy between the simulated and measured spectra was in the L- K-line data. The associated intensity (energy flux density) of the measured distributions was found to be up to 30% higher. Based on the measured distributions, predicted device responses were within 10% of the measured response as compared to about 30% accuracy obtained with simulated distributions.

  2. Photofragment energy distributions and dissociation pathways in dimethyl sulfoxide

    SciTech Connect

    Thorson, G.M.; Cheatum, C.M.; Coffey, M.J.; Fleming Crim, F.

    1999-06-01

    Photolysis of dimethyl sulfoxide in a molecular beam with 210 and 222 nm photons reveals the decomposition mechanism and energy disposal in the products. Using vacuum ultraviolet light and a time-of-flight spectrometer, we identify CH{sub 3} and CH{sub 3}SO as primary fragments and CH{sub 3} and SO as secondary fragments. From CH{sub 3} quantum yield measurements, we find that secondary decomposition is minor for 222 nm photolysis, occurring in only about 10{percent} of the fragments, but it increases to about 30{percent} in the 210 nm photolysis. Laser-induced fluorescence measurements on the B{sup 3}{Sigma}{sup {minus}}{l_arrow}X{sup 3}{Sigma}{sup {minus}} transition of SO in the 235 to 280 nm region determine the internal energy of that photoproduct. We compare our results to a simple statistical model that captures the essential features of the decomposition, predicting both the extent of secondary decomposition and the recoil energy of the primary and secondary methyl fragments. {copyright} {ital 1999 American Institute of Physics.}

  3. Absolute partial decay branching-ratios in 16O

    NASA Astrophysics Data System (ADS)

    Wheldon, C.; Ashwood, N. I.; Barr, M.; Curtis, N.; Freer, M.; Kokalova, Tz; Malcolm, J. D.; Spencer, S. J.; Ziman, V. A.; Faestermann, Th; Krücken, R.; Wirth, H.-F.; Hertenberger, R.; Lutter, R.; Bergmaier, A.

    2013-04-01

    The a-transfer reaction 126C(63Li, d)168O* has been performed at a 6Li bombarding energy of 42 MeV to populate excited states in 13C and 16O. Absolute branching ratios have been unambiguously determined for states in the excitation energy range 13.85 to 15.87 MeV and reduced widths are extracted.

  4. Theoretical modeling for neutron elastic scattering angular distribution in the fast energy range

    SciTech Connect

    Kawano, Toshihiko

    2010-12-07

    One of the major issues of neutron scattering modeling in the fast energy range is the contribution of compound elastic and inelastic scattering to the total scattering process. The compound component may become large at very low energies where the angular distribution becomes 90-degree symmetric in the center-of-mass system. Together with the shape elastic component, the elastic scattering gives slightly forward-peaked angular distributions in the fast energy range. This anisotropic angular distribution gives high sensitivities to many important nuclear reactor characteristics, such as criticality and neutron shielding. In this talk we describe how the anisotropic angular distributions are calculated within the statistical model framework, including the case where strongly coupled channels exist, by combining the coupled-channels theory with the Hauser-Feshbach model. This unique capability extension will have significant advantages in understanding the neutron scattering process for deformed nuclei, like uranium or plutonium, on which advanced nuclear energy applications center.

  5. The Energy Distribution of a Noncommutative Reissner—Nordström Black Hole

    NASA Astrophysics Data System (ADS)

    Kourosh, Nozari; Yazdani, A.

    2013-09-01

    We study the energy distribution of a noncommutative Reissner—Nordström black hole. We consider both Einstein and Møller prescriptions, and compare our results with the corresponding results obtained recently for a Schwarzschild black hole.

  6. Energy Efficiency of Distributed Signal Processing in Wireless Networks: A Cross-Layer Analysis

    NASA Astrophysics Data System (ADS)

    Geraci, Giovanni; Wildemeersch, Matthias; Quek, Tony Q. S.

    2016-02-01

    In order to meet the growing mobile data demand, future wireless networks will be equipped with a multitude of access points (APs). Besides the important implications for the energy consumption, the trend towards densification requires the development of decentralized and sustainable radio resource management techniques. It is critically important to understand how the distribution of signal processing operations affects the energy efficiency of wireless networks. In this paper, we provide a cross-layer framework to evaluate and compare the energy efficiency of wireless networks under different levels of distribution of the signal processing load: (i) hybrid, where the signal processing operations are shared between nodes and APs, (ii) centralized, where signal processing is entirely implemented at the APs, and (iii) fully distributed, where all operations are performed by the nodes. We find that in practical wireless networks, hybrid signal processing exhibits a significant energy efficiency gain over both centralized and fully distributed approaches.

  7. Unfolding the fission prompt gamma-ray energy and multiplicity distribution measured by DANCE

    SciTech Connect

    Chyzh, A; Wu, C Y; Bredeweg, T; Couture, A; Jandel, M; Ullmann, J; Laptev, A

    2010-10-16

    The nearly energy independence of the {gamma}-ray efficiency and multiplicity response for the DANCE array, the unusual characteristic elucidated in our early technical report (LLNL-TR-452298), gives one a unique opportunity to derive the true prompt {gamma}-ray energy and multiplicity distribution in fission from the measurement. This unfolding procedure for the experimental data will be described in details and examples will be given to demonstrate the feasibility of reconstruction of the true distribution.

  8. Ultrahigh energy neutrino-nucleon scattering and parton distributions at small x

    SciTech Connect

    Henley, Ernest M.; Jalilian-Marian, Jamal

    2006-05-01

    The cross section for ultrahigh energy neutrino-nucleon scattering is very sensitive to the parton distributions at very small values of Bjorken x (x{<=}10{sup -4}). We numerically investigate the effects of modifying the behavior of the gluon distribution function at very small x in the DGLAP evolution equation. We then use the Color Glass Condensate formalism to calculate the neutrino-nucleon cross section at ultrahigh energies and compare the result with those based on modification of DGLAP evolution equation.

  9. AN ACCURATE NEW METHOD OF CALCULATING ABSOLUTE MAGNITUDES AND K-CORRECTIONS APPLIED TO THE SLOAN FILTER SET

    SciTech Connect

    Beare, Richard; Brown, Michael J. I.; Pimbblet, Kevin

    2014-12-20

    We describe an accurate new method for determining absolute magnitudes, and hence also K-corrections, that is simpler than most previous methods, being based on a quadratic function of just one suitably chosen observed color. The method relies on the extensive and accurate new set of 129 empirical galaxy template spectral energy distributions from Brown et al. A key advantage of our method is that we can reliably estimate random errors in computed absolute magnitudes due to galaxy diversity, photometric error and redshift error. We derive K-corrections for the five Sloan Digital Sky Survey filters and provide parameter tables for use by the astronomical community. Using the New York Value-Added Galaxy Catalog, we compare our K-corrections with those from kcorrect. Our K-corrections produce absolute magnitudes that are generally in good agreement with kcorrect. Absolute griz magnitudes differ by less than 0.02 mag and those in the u band by ∼0.04 mag. The evolution of rest-frame colors as a function of redshift is better behaved using our method, with relatively few galaxies being assigned anomalously red colors and a tight red sequence being observed across the whole 0.0 < z < 0.5 redshift range.

  10. New algorithms for the Vavilov distribution calculation and the corresponding energy loss sampling

    SciTech Connect

    Chibani, O. |

    1998-10-01

    Two new algorithms for the fast calculation of the Vavilov distribution within the interval 0.01 {le} {kappa} {le} 10, where neither the Gaussian approximation nor the Landau distribution may be used, are presented. These algorithms are particularly convenient for the sampling of the corresponding random energy loss. A comparison with the exact Vavilov distribution for the case of protons traversing Al slabs is given.

  11. A method for the assessment of specific energy distribution in a model tumor system

    SciTech Connect

    Noska, M.A.

    1996-12-31

    Due to the short range of alpha particles in tissue, the calculation of dose from internally deposited alpha emitters requires a detailed analysis of the microscopic distribution of the radionuclide in order to determine the spatial distribution of energy emission events and, from this, the spatial distribution of dose. In the present study, the authors used quantitative autoradiography (QAR) to assess the microdistribution of a radiolabeled monoclonal antibody (MAb) fragment in human glioma xenografts in mice.

  12. Cross Section Sensitivity and Uncertainty Analysis Including Secondary Neutron Energy and Angular Distributions.

    1991-03-12

    Version 00 SUSD calculates sensitivity coefficients for one- and two-dimensional transport problems. Variance and standard deviation of detector responses or design parameters can be obtained using cross-section covariance matrices. In neutron transport problems, this code can perform sensitivity-uncertainty analysis for secondary angular distribution (SAD) or secondary energy distribution (SED).

  13. Electron energy distribution in a helium plasma created by nuclear radiations

    NASA Technical Reports Server (NTRS)

    Lo, R. H.; Miley, G. H.

    1974-01-01

    An integral balance technique for calculation of the electron energy distribution in a radiation-induced plasma is described. Results predict W-values reasonably well and compare favorably with more complicated Monte-Carlo calculations. The distribution found differs from that in a normal electrical discharge and is of interest in radiation-pumped laser research.

  14. Extrapolation of multiplicity distribution in p+p(\\bar{p}) collisions to LHC energies

    NASA Astrophysics Data System (ADS)

    Dash, Ajay Kumar; Mohanty, Bedangadas

    2010-02-01

    The multiplicity (Nch) and pseudorapidity distribution (dNch/dη) of primary charged particles in p + p collisions at Large Hadron Collider (LHC) energies of \\sqrt{s} = 10 and 14 TeV are obtained from extrapolation of existing measurements at lower \\sqrt{s}. These distributions are then compared to calculations from PYTHIA and PHOJET models. The existing \\sqrt{s} measurements are unable to distinguish between a logarithmic and power law dependence of the average charged particle multiplicity (langNchrang) on \\sqrt{s}, and their extrapolation to energies accessible at LHC give very different values. Assuming a reasonably good description of inclusive charged particle multiplicity distributions by negative binomial distribution (NBD) at lower \\sqrt{s} to hold for LHC energies, we observe that the logarithmic \\sqrt{s} dependences of langNchrang are favored by the models at midrapidity. The dNch/dη versus η distributions for the existing measurements are found to be reasonably well described by a function with three parameters which accounts for the basic features of the distribution, height at midrapidity, central rapidity plateau and the higher rapidity fall-off. Extrapolation of these parameters as a function of \\sqrt{s} is used to predict the pseudorapidity distributions of charged particles at LHC energies. dNch/dη calculations from PYTHIA and PHOJET models are found to be lower compared to those obtained from the extrapolated dNch/dη versus η distributions for a broad η range.

  15. Effects of the Electron Energy Distribution Function on Modeled X-ray Spectra

    SciTech Connect

    Shlyaptseva, A S; Hansen, S B

    2004-02-19

    This paper presents the results of a broad investigation into the effects of the electron energy distribution function on the predictions of non-LTE collisional-radiative atomic kinetics models. The effects of non-Maxwellian and suprathermal (''hot'') electron distributions on collisional rates (including three-body recombination) are studied. It is shown that most collisional rates are fairly insensitive to the functional form and characteristic energy of the electron distribution function as long as the characteristic energy is larger than the threshold energy for the collisional process. Collisional excitation and ionization rates, however, are highly sensitive to the fraction of hot electrons. This permits the development of robust spectroscopic diagnostics that can be used to characterize the electron density, bulk electron temperature, and hot electron fraction of plasmas with non-equilibrium electron distribution functions (EDFs). Hot electrons are shown to increase and spread out plasma charge state distributions, amplify the intensities of emission lines fed by direct collisional excitation and radiative cascades, and alter the structure of satellite features in both K- and L-shell spectra. The characteristic energy, functional form, and spatial properties of hot electron distributions in plasmas are open to characterization through their effects on high-energy continuum and line emission and on the polarization of spectral lines.

  16. The Integration of Renewable Energy Sources into Electric Power Distribution Systems, Vol. II Utility Case Assessments

    SciTech Connect

    Zaininger, H.W.

    1994-01-01

    Electric utility distribution system impacts associated with the integration of renewable energy sources such as photovoltaics (PV) and wind turbines (WT) are considered in this project. The impacts are expected to vary from site to site according to the following characteristics: the local solar insolation and/or wind characteristics, renewable energy source penetration level, whether battery or other energy storage systems are applied, and local utility distribution design standards and planning practices. Small, distributed renewable energy sources are connected to the utility distribution system like other, similar kW- and MW-scale equipment and loads. Residential applications are expected to be connected to single-phase 120/240-V secondaries. Larger kW-scale applications may be connected to three+phase secondaries, and larger hundred-kW and y-scale applications, such as MW-scale windfarms, or PV plants, may be connected to electric utility primary systems via customer-owned primary and secondary collection systems. In any case, the installation of small, distributed renewable energy sources is expected to have a significant impact on local utility distribution primary and secondary system economics. Small, distributed renewable energy sources installed on utility distribution systems will also produce nonsite-specific utility generation system benefits such as energy and capacity displacement benefits, in addition to the local site-specific distribution system benefits. Although generation system benefits are not site-specific, they are utility-specific, and they vary significantly among utilities in different regions. In addition, transmission system benefits, environmental benefits and other benefits may apply. These benefits also vary significantly among utilities and regions. Seven utility case studies considering PV, WT, and battery storage were conducted to identify a range of potential renewable energy source distribution system applications. The

  17. Quantitative analysis of the energy distributions of electrons backscattered elastically from polyethylene

    NASA Astrophysics Data System (ADS)

    Tőkési, K.; Varga, D.; Berényi, Z.

    2015-07-01

    We present results of theoretical and experimental studies of the spectra of electrons backscattered elastically from polyethylene in the primary energy range between 1 and 5 keV. The experiments were performed using a high energy resolution electron spectroscopy. The theoretical interpretation is based on a Monte Carlo simulation of the recoil and Doppler effects. The separation between the carbon and hydrogen peak in the energy distributions is shown as a function of the primary electron energy. The simulations give many partial distributions separately, depending on the number of elastic scatterings (single, and multiple scatterings of different types). We show our results for intensity ratios, peak shifts and broadenings. We also present detailed analytical calculations for the main parameters of a single scattering. Finally, we present a qualitative comparison with the experimental data. We find our resulting energy distribution of elastically scattered electrons to be in good agreement with our measurements.

  18. Stereotactic, Single-Dose Irradiation of Lung Tumors: A Comparison of Absolute Dose and Dose Distribution Between Pencil Beam and Monte Carlo Algorithms Based on Actual Patient CT Scans

    SciTech Connect

    Chen Huixiao; Lohr, Frank; Fritz, Peter; Wenz, Frederik; Dobler, Barbara; Lorenz, Friedlieb; Muehlnickel, Werner

    2010-11-01

    Purpose: Dose calculation based on pencil beam (PB) algorithms has its shortcomings predicting dose in tissue heterogeneities. The aim of this study was to compare dose distributions of clinically applied non-intensity-modulated radiotherapy 15-MV plans for stereotactic body radiotherapy between voxel Monte Carlo (XVMC) calculation and PB calculation for lung lesions. Methods and Materials: To validate XVMC, one treatment plan was verified in an inhomogeneous thorax phantom with EDR2 film (Eastman Kodak, Rochester, NY). Both measured and calculated (PB and XVMC) dose distributions were compared regarding profiles and isodoses. Then, 35 lung plans originally created for clinical treatment by PB calculation with the Eclipse planning system (Varian Medical Systems, Palo Alto, CA) were recalculated by XVMC (investigational implementation in PrecisePLAN [Elekta AB, Stockholm, Sweden]). Clinically relevant dose-volume parameters for target and lung tissue were compared and analyzed statistically. Results: The XVMC calculation agreed well with film measurements (<1% difference in lateral profile), whereas the deviation between PB calculation and film measurements was up to +15%. On analysis of 35 clinical cases, the mean dose, minimal dose and coverage dose value for 95% volume of gross tumor volume were 1.14 {+-} 1.72 Gy, 1.68 {+-} 1.47 Gy, and 1.24 {+-} 1.04 Gy lower by XVMC compared with PB, respectively (prescription dose, 30 Gy). The volume covered by the 9 Gy isodose of lung was 2.73% {+-} 3.12% higher when calculated by XVMC compared with PB. The largest differences were observed for small lesions circumferentially encompassed by lung tissue. Conclusions: Pencil beam dose calculation overestimates dose to the tumor and underestimates lung volumes exposed to a given dose consistently for 15-MV photons. The degree of difference between XVMC and PB is tumor size and location dependent. Therefore XVMC calculation is helpful to further optimize treatment planning.

  19. The integration of renewable energy sources into electric power distribution systems. Volume 2, Utility case assessments

    SciTech Connect

    Zaininger, H.W.; Ellis, P.R.; Schaefer, J.C.

    1994-06-01

    Electric utility distribution system impacts associated with the integration of renewable energy sources such as photovoltaics (PV) and wind turbines (WT) are considered in this project. The impacts are expected to vary from site to site according to the following characteristics: (1) The local solar insolation and/or wind characteristics; (2) renewable energy source penetration level; (3) whether battery or other energy storage systems are applied; and (4) local utility distribution design standards and planning practices. Small, distributed renewable energy sources are connected to the utility distribution system like other, similar kW- and MW-scale equipment and loads. Residential applications are expected to be connected to single-phase 120/240-V secondaries. Larger kw-scale applications may be connected to three-phase secondaries, and larger hundred-kW and MW-scale applications, such as MW-scale windfarms or PV plants, may be connected to electric utility primary systems via customer-owned primary and secondary collection systems. Small, distributed renewable energy sources installed on utility distribution systems will also produce nonsite-specific utility generation system benefits such as energy and capacity displacement benefits, in addition to the local site-specific distribution system benefits. Although generation system benefits are not site-specific, they are utility-specific, and they vary significantly among utilities in different regions. In addition, transmission system benefits, environmental benefits and other benefits may apply. These benefits also vary significantly among utilities and regions. Seven utility case studies considering PV, WT, and battery storage were conducted to identify a range of potential renewable energy source distribution system applications.

  20. Inequalities, Absolute Value, and Logical Connectives.

    ERIC Educational Resources Information Center

    Parish, Charles R.

    1992-01-01

    Presents an approach to the concept of absolute value that alleviates students' problems with the traditional definition and the use of logical connectives in solving related problems. Uses a model that maps numbers from a horizontal number line to a vertical ray originating from the origin. Provides examples solving absolute value equations and…

  1. Absolute optical metrology : nanometers to kilometers

    NASA Technical Reports Server (NTRS)

    Dubovitsky, Serge; Lay, O. P.; Peters, R. D.; Liebe, C. C.

    2005-01-01

    We provide and overview of the developments in the field of high-accuracy absolute optical metrology with emphasis on space-based applications. Specific work on the Modulation Sideband Technology for Absolute Ranging (MSTAR) sensor is described along with novel applications of the sensor.

  2. Monolithically integrated absolute frequency comb laser system

    DOEpatents

    Wanke, Michael C.

    2016-07-12

    Rather than down-convert optical frequencies, a QCL laser system directly generates a THz frequency comb in a compact monolithically integrated chip that can be locked to an absolute frequency without the need of a frequency-comb synthesizer. The monolithic, absolute frequency comb can provide a THz frequency reference and tool for high-resolution broad band spectroscopy.

  3. Introducing the Mean Absolute Deviation "Effect" Size

    ERIC Educational Resources Information Center

    Gorard, Stephen

    2015-01-01

    This paper revisits the use of effect sizes in the analysis of experimental and similar results, and reminds readers of the relative advantages of the mean absolute deviation as a measure of variation, as opposed to the more complex standard deviation. The mean absolute deviation is easier to use and understand, and more tolerant of extreme…

  4. Investigating Absolute Value: A Real World Application

    ERIC Educational Resources Information Center

    Kidd, Margaret; Pagni, David

    2009-01-01

    Making connections between various representations is important in mathematics. In this article, the authors discuss the numeric, algebraic, and graphical representations of sums of absolute values of linear functions. The initial explanations are accessible to all students who have experience graphing and who understand that absolute value simply…

  5. Absolute Income, Relative Income, and Happiness

    ERIC Educational Resources Information Center

    Ball, Richard; Chernova, Kateryna

    2008-01-01

    This paper uses data from the World Values Survey to investigate how an individual's self-reported happiness is related to (i) the level of her income in absolute terms, and (ii) the level of her income relative to other people in her country. The main findings are that (i) both absolute and relative income are positively and significantly…

  6. Improving Power Quality in Low-Voltage Networks Containing Distributed Energy Resources

    NASA Astrophysics Data System (ADS)

    Mazumder, Sumit; Ghosh, Arindam; Zare, Firuz

    2013-05-01

    Severe power quality problems can arise when a large number of single-phase distributed energy resources (DERs) are connected to a low-voltage power distribution system. Due to the random location and size of DERs, it may so happen that a particular phase generates excess power than its load demand. In such an event, the excess power will be fed back to the distribution substation and will eventually find its way to the transmission network, causing undesirable voltage-current unbalance. As a solution to this problem, the article proposes the use of a distribution static compensator (DSTATCOM), which regulates voltage at the point of common coupling (PCC), thereby ensuring balanced current flow from and to the distribution substation. Additionally, this device can also support the distribution network in the absence of the utility connection, making the distribution system work as a microgrid. The proposals are validated through extensive digital computer simulation studies using PSCADTM.

  7. On the Electron Energy Distribution Index of Swift Gamma-ray Burst Afterglows

    NASA Astrophysics Data System (ADS)

    Curran, P. A.; Evans, P. A.; de Pasquale, M.; Page, M. J.; van der Horst, A. J.

    2010-06-01

    The electron energy distribution index, p, is a fundamental parameter of the synchrotron emission from a range of astronomical sources. Here we examine one such source of synchrotron emission, gamma-ray burst (GRB) afterglows observed by the Swift satellite. Within the framework of the blast wave model, we examine the constraints placed on the distribution of p by the observed X-ray spectral indices and parameterize the distribution. We find that the observed distribution of spectral indices are inconsistent with an underlying distribution of p composed of a single discrete value but consistent with a Gaussian distribution centered at p = 2.36 and having a width of 0.59. Furthermore, accepting that the underlying distribution is a Gaussian, we find that the majority (gsim94%) of GRB afterglows in our sample have cooling break frequencies less than the X-ray frequency.

  8. Effects of wind-energy facilities on grassland bird distributions

    USGS Publications Warehouse

    Shaffer, Jill A.; Buhl, Deb

    2016-01-01

    The contribution of renewable energy to meet worldwide demand continues to grow. Wind energy is one of the fastest growing renewable sectors, but new wind facilities are often placed in prime wildlife habitat. Long-term studies that incorporate a rigorous statistical design to evaluate the effects of wind facilities on wildlife are rare. We conducted a before-after-control-impact (BACI) assessment to determine if wind facilities placed in native mixed-grass prairies displaced breeding grassland birds. During 2003–2012, we monitored changes in bird density in 3 study areas in North Dakota and South Dakota (U.S.A.). We examined whether displacement or attraction occurred 1 year after construction (immediate effect) and the average displacement or attraction 2–5 years after construction (delayed effect). We tested for these effects overall and within distance bands of 100, 200, 300, and >300 m from turbines. We observed displacement for 7 of 9 species. One species was unaffected by wind facilities and one species exhibited attraction. Displacement and attraction generally occurred within 100 m and often extended up to 300 m. In a few instances, displacement extended beyond 300 m. Displacement and attraction occurred 1 year after construction and persisted at least 5 years. Our research provides a framework for applying a BACI design to displacement studies and highlights the erroneous conclusions that can be made without the benefit of adopting such a design. More broadly, species-specific behaviors can be used to inform management decisions about turbine placement and the potential impact to individual species. Additionally, the avoidance distance metrics we estimated can facilitate future development of models evaluating impacts of wind facilities under differing land-use scenarios.

  9. Power Hardware-in-the-Loop (PHIL) Testing Facility for Distributed Energy Storage (Poster)

    SciTech Connect

    Neubauer.J.; Lundstrom, B.; Simpson, M.; Pratt, A.

    2014-06-01

    The growing deployment of distributed, variable generation and evolving end-user load profiles presents a unique set of challenges to grid operators responsible for providing reliable and high quality electrical service. Mass deployment of distributed energy storage systems (DESS) has the potential to solve many of the associated integration issues while offering reliability and energy security benefits other solutions cannot. However, tools to develop, optimize, and validate DESS control strategies and hardware are in short supply. To fill this gap, NREL has constructed a power hardware-in-the-loop (PHIL) test facility that connects DESS, grid simulator, and load bank hardware to a distribution feeder simulation.

  10. THE ROLE AND DISTRIBUTION OF WRITTEN INFORMAL COMMUNICATION IN THEORETICAL HIGH ENERGY PHYSICS.

    ERIC Educational Resources Information Center

    LIBBEY, MILES A.; ZALTMAN, GERALD

    THIS STUDY OF "PREPRINT" DISTRIBUTION IN THEORECTICAL HIGH ENERGY PHYSICS USED A QUESTIONNAIRE CIRCULATED TO ALL KNOWN HIGH ENERGY THEORISTS. A SECOND QUESTIONNAIRE WAS SENT TO A REPRESENTATIVE SAMPLE OF "PREPRINT LIBRARIANS" AT VARIOUS INSTITUTIONS IN THE U.S. AND ABROAD. BASED ON THIS DATA, THE STUDY CONCLUDED THAT AN EXPERIMENT WITH CENTRALIZED…

  11. Laser-produced relativistic electron energy and angular distributions in thin foils

    SciTech Connect

    Rastunkov, V.S.; Krainov, V.P.

    2006-02-15

    Energy and angular distributions are obtained for electrons at the rear surface of thin foils irradiated by an oblique relativistic laser pulse. Vacuum heating at the front surface in the summary field of incident and reflected laser waves is considered as a main mechanism of electron heating up to relativistic ponderomotive energies.

  12. Mini-implants and miniplates generate sub-absolute and absolute anchorage

    PubMed Central

    Consolaro, Alberto

    2014-01-01

    The functional demand imposed on bone promotes changes in the spatial properties of osteocytes as well as in their extensions uniformly distributed throughout the mineralized surface. Once spatial deformation is established, osteocytes create the need for structural adaptations that result in bone formation and resorption that happen to meet the functional demands. The endosteum and the periosteum are the effectors responsible for stimulating adaptive osteocytes in the inner and outer surfaces.Changes in shape, volume and position of the jaws as a result of skeletal correction of the maxilla and mandible require anchorage to allow bone remodeling to redefine morphology, esthetics and function as a result of spatial deformation conducted by orthodontic appliances. Examining the degree of changes in shape, volume and structural relationship of areas where mini-implants and miniplates are placed allows us to classify mini-implants as devices of subabsolute anchorage and miniplates as devices of absolute anchorage. PMID:25162561

  13. Energy spreading and angular distribution of a beam of electrons in molecular hydrogen

    NASA Technical Reports Server (NTRS)

    Heaps, M. G.; Green, A. E. S.

    1975-01-01

    A Monte Carlo approach is used to obtain the energy spreading and angular distribution of initially monoenergetic and monodirectional beams of electron incident on a gas of molecular hydrogen. Several beams of primary electrons and the resultant secondaries are degraded in a step-by-step procedure which utilizes a detailed set of cross sections, together with reasonable approximations for the creation of secondary electrons. Particular attention is paid to the initial angular distribution of secondary electrons. An analytic function which characterizes current experimental differential cross-section data is used to provide realistic inputs into our calculations. The results for energy distribution as a function of distance and angular distribution at selected energies and distances are illustrated.

  14. Inferring the Energy Distribution of Accelerated Electrons in Solar Flares from X-ray Observations

    NASA Technical Reports Server (NTRS)

    Holman, Gordon D.; Sui, Linhui; Su, Yang

    2008-01-01

    Knowledge of the energy distribution of electrons accelerated in solar flares is important for constraining possible acceleration mechanisms and for understanding the relationships between flare X-ray sources, radio sources, and particles observed in space. Solar flare hard X-rays are primarily emitted from dense, thick-target regions in the lower atmosphere, but the electrons are understood to be accelerated higher in the corona. Various processes can distort the X-ray spectrum or the energy distribution of electrons before they reach the thick-target region. After briefly reviewing the processes that affect the X-ray spectrum and the electron distribution, I will describe recent results from a study of flare spectra from RHESSI to determine the importance of these processes in inferring the energy distribution of accelerated electrons.

  15. Electron energy distribution function by using probe method in electron cyclotron resonance multicharged ion source

    SciTech Connect

    Kumakura, Sho Kurisu, Yosuke; Kimura, Daiju; Yano, Keisuke; Imai, Youta; Sato, Fuminobu; Kato, Yushi; Iida, Toshiyuki

    2014-02-15

    We are constructing a tandem type electron cyclotron resonance (ECR) ion source (ECRIS). High-energy electrons in ECRIS plasma affect electron energy distribution and generate multicharged ion. In this study, we measure electron energy distribution function (EEDF) of low energy region (≦100 eV) in ECRIS plasma at extremely low pressures (10{sup −3}–10{sup −5} Pa) by using cylindrical Langmuir probe. From the result, it is found that the EEDF correlates with the electron density and the temperature from the conventional probe analysis. In addition, we confirm that the tail of EEDF spreads to high energy region as the pressure rises and that there are electrons with high energy in ECR multicharged ion source plasma. The effective temperature estimated from the experimentally obtained EEDF is larger than the electron temperature obtained from the conventional method.

  16. Implication of radiative forcing distribution for energy transport

    NASA Astrophysics Data System (ADS)

    Huang, Yi

    2016-04-01

    Radiative forcing of a homogeneous greenhouse gas can be very inhomogeneous because the forcing is dependent on other atmospheric and surface variables. In the case of doubling CO2, the mean instantaneous forcing at the top of the atmosphere is found to vary geographically and temporally from positive to negative values, with the range being more than three times the magnitude of the global mean value. The vertical temperature change across the atmospheric column (temperature lapse rate) is found to be the best single predictor for explaining forcing variation. In addition, the masking effects of clouds and water vapor also contribute to forcing inhomogeneity. A regression model that predicts forcing from geophysical variables is constructed. This model can explain more than 90% of the variance of the forcing. Applying this model to analyzing the forcing variation in the CMIP5 models, we find that inter-model discrepancy in CO2 forcing caused by model climatology leads to considerable discrepancy in their projected change in poleward energy transport.

  17. Tsallis nonextensive entropy and the multiplicity distributions in high energy leptonic collisions

    NASA Astrophysics Data System (ADS)

    Sharma, S.; Kaur, M.; Kaur, Sandeep

    2016-06-01

    The nonextensive behavior of entropy is exploited to explain the regularity in multiplicity distributions in e+e‑ collisions at high energies. The experimental data are analyzed by using Tsallis q-statistics. We propose a new approach of applying Tsallis q-statistics, wherein the multiplicity distribution is divided into two components; two-jet and multijet components. A convoluted Tsallis distribution is fitted to the data. It is shown that this method gives the best fits which are several orders better than the conventional fit of Tsallis distribution.

  18. PHOTOMETRIC REDSHIFTS AND SYSTEMATIC VARIATIONS IN THE SPECTRAL ENERGY DISTRIBUTIONS OF LUMINOUS RED GALAXIES FROM SDSS DR7

    SciTech Connect

    Greisel, N.; Seitz, S.; Bender, R.; Saglia, R. P.; Snigula, J.; Drory, N.

    2013-05-10

    We describe the construction of a template set of spectral energy distributions (SEDs) for the estimation of photometric redshifts of luminous red galaxies (LRGs) with a Bayesian template fitting method. By examining the color properties of several publicly available SED sets within a redshift range of 0 < z {approx}< 0.5 and comparing them to Sloan Digital Sky Survey (SDSS) Data Release 7 data, we show that only some of the investigated SEDs approximately match the colors of the LRG data throughout the redshift range, however not at the quantitative level required for precise photometric redshifts. This is because the SEDs of galaxies evolve with time (and redshift) and because at fixed redshift the LRG colors have an intrinsic spread such that they cannot be matched by one SED only. We generate new SEDs by superposing model SEDs of composite stellar populations with a burst model, allowing both components to be reddened by dust, in order to match the data in five different redshift bins. We select a set of SEDs which represents the LRG data in color space within five redshift bins, thus defining our new SED template set for photometric redshift estimates. The results we obtain with the new template set and our Bayesian template fitting photometric redshift code (PhotoZ) are nearly unbiased, with a scatter of {sigma}{sub {Delta}z} = 0.027 (including outliers), a fraction of catastrophic outliers (|z{sub phot} - z{sub spec}|/(1 + z{sub spec}) > 0.15) of {eta} = 0.12%, and a normalized median absolute rest frame deviation (NMAD) of {sigma}{sub NMAD} = 1.48 Multiplication-Sign MAD = 0.017 for non-outliers. We show that templates that optimally describe the brightest galaxies (-24.5 {<=} M{sub R} {<=} -22.7) indeed vary from z = 0.1 to z = 0.5, consistent with aging of the stellar population. Furthermore, we find that templates that optimally describe galaxies at z < 0.1 strongly differ as a function of the absolute magnitude of the galaxies, indicating an increase in

  19. Direct comparisons between absolute and relative geomagnetic paleointensities: Absolute calibration of a relative paleointensity stack

    NASA Astrophysics Data System (ADS)

    Mochizuki, N.; Yamamoto, Y.; Hatakeyama, T.; Shibuya, H.

    2013-12-01

    Absolute geomagnetic paleointensities (APIs) have been estimated from igneous rocks, while relative paleomagnetic intensities (RPIs) have been reported from sediment cores. These two datasets have been treated separately, as correlations between APIs and RPIs are difficult on account of age uncertainties. High-resolution RPI stacks have been constructed from globally distributed sediment cores with high sedimentation rates. Previous studies often assumed that the RPI stacks have a linear relationship with geomagnetic axial dipole moments, and calibrated the RPI values to API values. However, the assumption of a linear relationship between APIs and RPIs has not been evaluated. Also, a quantitative calibration method for the RPI is lacking. We present a procedure for directly comparing API and RPI stacks, thus allowing reliable calibrations of RPIs. Direct comparisons between APIs and RPIs were conducted with virtually no associated age errors using both tephrochronologic correlations and RPI minima. Using the stratigraphic positions of tephra layers in oxygen isotope stratigraphic records, we directly compared the RPIs and APIs reported from welded tuffs contemporaneously extruded with the tephra layers. In addition, RPI minima during geomagnetic reversals and excursions were compared with APIs corresponding to the reversals and excursions. The comparison of APIs and RPIs at these exact points allowed a reliable calibration of the RPI values. We applied this direct comparison procedure to the global RPI stack PISO-1500. For six independent calibration points, virtual axial dipole moments (VADMs) from the corresponding APIs and RPIs of the PISO-1500 stack showed a near-linear relationship. On the basis of the linear relationship, RPIs of the stack were successfully calibrated to the VADMs. The direct comparison procedure provides an absolute calibration method that will contribute to the recovery of temporal variations and distributions of geomagnetic axial dipole

  20. K-Eigenvalue sensitivities of secondary distributions of continuous-energy data

    SciTech Connect

    Kiedrowski, B. C.; Brown, F. B.

    2013-07-01

    MCNP6 has the capability to produce energy-resolved sensitivity profiles for secondary distributions (fission {Chi} and scattering laws). Computing both unconstrained and constrained profiles are possible. Verification is performed with analytic test problems and a comparison to TSUNAMI-3D, and the comparisons show MCNP6 calculates correct or consistent results. Continuous-energy calculations are performed for three fast critical experiments: Jezebel, Flattop, and copper-reflected Zeus. The sensitivities to the secondary distributions (integrated over chosen energy ranges) are of similar magnitude to those of many of the cross sections, demonstrating the possibility that integral experiments are useful for assessing the fidelity of these data as well. (authors)

  1. Spatial measurements of electron energy distribution and plasma parameters in a weakly magnetized inductive discharge

    SciTech Connect

    Kim, Young-Do; Lee, Young-Kwang; Lee, Hyo-Chang; Chung, Chin-Wook

    2013-02-15

    Spatial characteristics of plasma parameters such as electron temperature, plasma density, plasma potential, and electron energy distribution (EED) were studied in inductively coupled plasma with an axial dc magnetic field. With dc magnetic field, the measured EEDs in the total electron energy scale are spatially coincided except cutting of the low electron energy part indicating the conserved non-local electron kinetics in an axial direction, even though the dc magnetic field is applied. Spatial distributions of the plasma densities at axial positions have almost same trends with various magnetic field strengths. We also discuss the reduction of the ambipolar potential along the axial direction as the applied magnetic field increased.

  2. Ion energy and angular distributions in inductively driven RF discharges in chlorine

    SciTech Connect

    Woodworth, J.R.; Riley, M.E.; Hamilton, T.W.

    1996-03-01

    In this paper, the authors report values of ion energy distributions and ion angular distributions measured at the grounded electrode of an inductively-coupled discharge in pure chlorine gas. The inductive drive in the GEC reference cell produced high plasma densities (10{sup 11}/cm{sup 3} electron densities) and stable plasma potentials. As a result, ion energy distributions typically consisted of a single peak well separated from zero energy. Mean ion energy varied inversely with pressure, decreasing from 13 to 9 eV as the discharge pressure increased from 20 to 60 millitorr. Half-widths of the ion angular distributions in these experiments varied from 6 to 7.5 degrees, corresponding to transverse energies from 0.13 to 0.21 eV. Ion energies gradually dropped with time, probably due to the buildup of contaminants on the chamber walls. Cell temperature also was an important variable, with ion fluxes to the lower electrode increasing and the ion angular distribution narrowing as the cell temperature increased. Plasmas discharges are widely used to etch semiconductors, oxides and metals in the fabrication of integrated circuits.

  3. Invalid phase values removal method for absolute phase recovery.

    PubMed

    Lu, Jin; Mo, Rong; Sun, Huibin; Chang, Zhiyong; Zhao, Xiaxia

    2016-01-10

    A novel approach is presented for more effectively removing invalid phase values in absolute phase recovery. The approach is based on a detailed study involving the types and cases of invalid phase values. Meanwhile, some commonalities of the existing removal algorithms also are thoroughly analyzed. It is well known that rough absolute phase and fringe order maps can very easily be obtained by temporal phase unwrapping techniques. After carefully analyzing the components and fringe order distribution of the rough fringe order map, the proposed method chiefly adopts an entirely new strategy to refine a pure fringe order map. The strategy consists of three parts: (1) the square of an image gradient, (2) subregion areas of the binary image, and (3) image decomposition and composition. In combination with the pure fringe order map and a removal criterion, the invalid phase values can be identified and filtered out from the rough absolute phase map. This new strategy not only gets rid of the limitations of traditional removal methods but also has a two-fold function. The paper also offers different metrics from the experiment to evaluate the quality of the final absolute phase. In contrast with other removal methods, experimental results have verified the feasibility, effectiveness, and superiority of the proposed method. PMID:26835776

  4. An Evaluation of Trading Methods for a Distributed Energy Management System

    NASA Astrophysics Data System (ADS)

    Yakire, Koji; Miyamoto, Toshiyuki; Kumagai, Sadatoshi; Mori, Kazuyuki; Kitamura, Shoichi; Yamamoto, Takaya

    Control of CO2 emissions which is the main factor of global warming is one of the most important problems in the 21st century about preservation of earth environment. Therefore, efficient supply and use of energy are indispensable. We have proposed distributed energy management systems (DEMSs), where we are to obtain optimal plans that minimize both of costs and of CO2 emissions through electrical and thermal energy trading. In this paper, we evaluate trading methods for the DEMSs by computational experiments.

  5. Angular distribution, kinetic energy distributions, and excitation functions of fast metastable oxygen fragments following electron impact of CO2

    NASA Technical Reports Server (NTRS)

    Misakian, M.; Mumma, M. J.; Faris, J. F.

    1975-01-01

    Dissociative excitation of CO2 by electron impact was studied using the methods of translational spectroscopy and angular distribution analysis. Earlier time of flight studies revealed two overlapping spectra, the slower of which was attributed to metastable CO(a3 pi) fragments. The fast peak is the focus of this study. Threshold energy, angular distribution, and improve time of flight measurements indicate that the fast peak actually consists of five overlapping features. The slowest of the five features is found to consist of metastable 0(5S) produced by predissociation of a sigma u + state of CO2 into 0(5S) + CO(a3 pi). Oxygen Rydberg fragments originating directly from a different sigma u + state are believed to make up the next fastest feature. Mechanisms for producing the three remaining features are discussed.

  6. Dipole-strength distributions up to the particle-separation energies and photodissociation of Mo isotopes

    NASA Astrophysics Data System (ADS)

    Schwengner, R.; Benouaret, N.; Beyer, R.; Dönau, F.; Erhard, M.; Frauendorf, S.; Grosse, E.; Junghans, A. R.; Klug, J.; Kosev, K.; Nair, C.; Nankov, N.; Rusev, G.; Schilling, K. D.; Wagner, A.

    2007-05-01

    Dipole-strength distributions in the nuclides 92Mo, 98Mo and 100Mo have been investigated in photon-scattering experiments with bremsstrahlung at the superconducting electron accelerator ELBE of the Forschungszentrum Rossendorf. A simulation of γ cascades was performed in order to estimate the distribution of inelastic transitions to low-lying states and thus to deduce the primary dipole-strength distribution up to the neutron-separation energies. The absorption cross sections obtained connect smoothly to ( γ, n) cross sections and give novel information about the low-energy tail of the Giant Dipole Resonance below the neutron-separation energies. The experimental cross sections are compared with predictions of a Quasiparticle-Random-Phase Approximation (QRPA) in a deformed basis. Photoactivation experiments were performed at various electron energies to study the 92Mo( γ, n), 92Mo( γ, p), 92Mo( γ, α) and 100Mo( γ, n) reactions. The deduced activation yields are compared with theoretical predictions.

  7. Efficient first-principles calculation of the quantum kinetic energy and momentum distribution of nuclei.

    PubMed

    Ceriotti, Michele; Manolopoulos, David E

    2012-09-01

    Light nuclei at room temperature and below exhibit a kinetic energy which significantly deviates from the predictions of classical statistical mechanics. This quantum kinetic energy is responsible for a wide variety of isotope effects of interest in fields ranging from chemistry to climatology. It also furnishes the second moment of the nuclear momentum distribution, which contains subtle information about the chemical environment and has recently become accessible to deep inelastic neutron scattering experiments. Here, we show how, by combining imaginary time path integral dynamics with a carefully designed generalized Langevin equation, it is possible to dramatically reduce the expense of computing the quantum kinetic energy. We also introduce a transient anisotropic Gaussian approximation to the nuclear momentum distribution which can be calculated with negligible additional effort. As an example, we evaluate the structural properties, the quantum kinetic energy, and the nuclear momentum distribution for a first-principles simulation of liquid water. PMID:23005275

  8. Two Instruments for Measuring Distributions of Low-Energy Charged Particles in Space

    NASA Technical Reports Server (NTRS)

    Bader, Michel; Fryer, Thomas B.; Witteborn, Fred C.

    1961-01-01

    Current estimates indicate that the bulk of interplanetary gas consists of protons with energies between 0 and 20 kev and concentrations of 1 to 105 particles/cu cm. Methods and instrumentation for measuring the energy and density distribution of such a gas are considered from the standpoint of suitability for space vehicle payloads. It is concluded that electrostatic analysis of the energy distribution can provide sufficient information in initial experiments. Both magnetic and electrostatic analyzers should eventually be used. Several instruments designed and constructed at the Ames Research Center for space plasma measurements, and the methods of calibration and data reduction are described. In particular, the instrument designed for operation on solar cell power has the following characteristics: weight, 1.1 pounds; size, 2 by 3 by 4 inches; and power consumption, 145 mw. The instrument is designed to yield information on the concentration, energy distribution, and the anisotropy of ion trajectories in the 0.2 to 20 kev range.

  9. An APL program for the distribution of energy deposition by charged particles passing through thin absorbers

    NASA Technical Reports Server (NTRS)

    Howell, L. W.

    1985-01-01

    An APL program which numerically evaluates the probability density function (PDF) for the energy deposited in a thin absorber by a charged particle is proposed, with application to the construction, pointing, and control of spacecraft. With this program, the PDF of the restricted energy loss distribution of Watts (1973) is derived, and Vavilov's (1957) distribution is obtained by proper parameter selection. The method is demonstrated with the example of the effect of charged particle induced radiation on the Hubble Space Telescope (HST) pointing accuracy. A Monte Carlo study simulates the photon noise caused by charged particles passing through the photomultiplier tube window, and the stochastic variation of energy loss is introduced into the simulation by generating random energy losses from a power law distribution. The program eliminates annoying loop procedures, and model parameter sensitivity can be studied using the graphical output.

  10. Visual discomfort and the spatial distribution of Fourier energy.

    PubMed

    Penacchio, Olivier; Wilkins, Arnold J

    2015-03-01

    Quite independently of what they represent, some images provoke discomfort, and even headaches and seizures in susceptible individuals. The visual system has adapted to efficiently process the images it typically experiences, and in nature these images are usually scale-invariant. In this work, we sought to characterize the images responsible for discomfort in terms of their adherence to low-level statistical properties typically seen in natural scenes. It has been conventional to measure scale invariance in terms of the one-dimensional Fourier amplitude spectrum, by averaging amplitude over orientations in the Fourier domain. However, this loses information on the evenness with which information at various orientations is represented. We therefore fitted a two-dimensional surface (regular circular cone 1/f in logarithmic coordinates) to the two-dimensional amplitude spectrum. The extent to which the cone fitted the spectrum explained an average of 18% of the variance in judgments of discomfort from images including rural and urban scenes, works of non-representational art, images of buildings and animals, and images generated from randomly disposed discs of varying contrast and size. Weighting the spectrum prior to fitting the surface to allow for the spatial frequency tuning of contrast sensitivity explained an average of 27% of the variance. Adjusting the shape of the cone to take account of the generally greater energy in horizontal and vertical orientations improved the fit, but only slightly. Taken together, our findings show that a simple measure based on first principles of efficient coding and human visual sensitivity explained more variance than previously published algorithms. The algorithm has a low computational cost and we show that it can identify the images involved in cases that have reached the media because of complaints. We offer the algorithm as a tool for designers rather than as a simulation of the biological processes involved. PMID:25576380

  11. Advanced Communication and Control of Distributed Energy Resources at Detroit Edison

    SciTech Connect

    Haukur Asgeirsson; Richard Seguin

    2004-01-31

    The project objective was to create the communication and control system, the process and the economic procedures that will allow owners (e.g., residential, commercial, industrial, manufacturing, etc.) of Distributed Energy Resources (DER) connected in parallel to the electric distribution to have their resources operated in a manner that protects the electric utility distribution network and personnel that may be working on the network. The Distribution Engineering Workstation (DEW) (a power flow and short circuit modeling tool) was modified to calculate the real-time characteristics of the distribution network based on the real-time electric distribution network information and provide DER operating suggestions to the Detroit Edison system operators so that regional electric stability is maintained. Part of the suggestion algorithm takes into account the operational availability of DER’s, which is known by the Energy Aggregator, DTE Energy Technologies. The availability information will be exchanged from DTE Energy Technologies to Detroit Edison. For the calculated suggestions to be used by the Detroit Edison operators, procedures were developed to allow an operator to operate a DER by requesting operation of the DER through DTE Energy Technologies. Prior to issuing control of a DER, the safety of the distribution network and personnel needs to be taken into account. This information will be exchanged from Detroit Edison to DTE Energy Technologies. Once it is safe to control the DER, DTE Energy Technologies will issue the control signal. The real-time monitoring of the DECo system will reflect the DER control. Multi-vendor DER technologies’ representing approximately 4 MW of capacity was monitored and controlled using a web-based communication path. The DER technologies included are a photovoltaic system, energy storage, fuel cells and natural gas/diesel internal combustion engine generators. This report documents Phase I result for the Detroit Edison

  12. Absolute optical instruments without spherical symmetry

    NASA Astrophysics Data System (ADS)

    Tyc, Tomáš; Dao, H. L.; Danner, Aaron J.

    2015-11-01

    Until now, the known set of absolute optical instruments has been limited to those containing high levels of symmetry. Here, we demonstrate a method of mathematically constructing refractive index profiles that result in asymmetric absolute optical instruments. The method is based on the analogy between geometrical optics and classical mechanics and employs Lagrangians that separate in Cartesian coordinates. In addition, our method can be used to construct the index profiles of most previously known absolute optical instruments, as well as infinitely many different ones.

  13. Ion energy and angular distributions in inductively coupled Argon RF discharges

    SciTech Connect

    Woodworth, J.R.; Riley, M.E.; Meister, D.C.

    1996-03-01

    We report measurements of the energies and angular distributions of positive ions in an inductively coupled argon plasma in a GEC reference cell. Use of two separate ion detectors allowed measurement of ion energies and fluxes as a function of position as well as ion angular distributions on the discharge centerline. The inductive drive on our system produced high plasma densities (up to 10{sup 12}/cm{sup 3} electron densities) and relatively stable plasma potentials. As a result, ion energy distributions typically consisted of a single feature well separated from zero energy. Mean ion energy was independent of rf power and varied inversely with pressure, decreasing from 29 eV to 12 eV as pressure increased form 2.4 m Torr to 50 mTorr. Half-widths of the ion angular distributions in these experiments varied from 5 degrees to 12.5 degrees, or equivalently, transverse temperatures varied form 0.2 to 0.5 eV with the distributions broadening as either pressure or RF power were increased.

  14. Beam energy distribution influences on density modulation efficiency in seeded free-electron lasers

    NASA Astrophysics Data System (ADS)

    Wang, Guanglei; Zhang, Weiqing; Wu, Guorong; Dai, Dongxu; Yang, Xueming; Feng, Chao; Zhang, Meng; Deng, Haixiao; Wang, Dong; Zhao, Zhentang

    2015-06-01

    The beam energy spread at the entrance of an undulator system is of paramount importance for efficient density modulation in high-gain seeded free-electron lasers (FELs). In this paper, the dependences of high harmonic bunching efficiency in high-gain harmonic generation (HGHG), echo-enabled harmonic generation (EEHG) and phase-merging enhanced harmonic generation (PEHG) schemes on the electron beam energy spread distribution are studied. Theoretical investigations and multidimensional numerical simulations are applied to the cases of uniform and saddle beam energy distributions and compared to a traditional Gaussian distribution. It shows that the uniform and saddle electron energy distributions significantly enhance the bunching performance of HGHG FELs, while they almost have no influence on EEHG and PEHG schemes. A further start-to-end simulation example demonstrated that, with the saddle distribution of sliced beam energy spread controlled by a laser heater, the 30th harmonic can be directly generated by a single-stage HGHG scheme for a soft x-ray FEL facility.

  15. Effects of Home Energy Management Systems on Distribution Utilities and Feeders Under Various Market Structure; NREL (National Renewable Energy Laboratory)

    SciTech Connect

    Ruth, M.; Pratt, A.; Lunacek, M.; Mittal, S.; Wu, H.; Jones, W.

    2015-06-15

    The combination of distributed energy resources (DER) and retail tariff structures to provide benefits to both utility consumers and the utilities is not well understood. To improve understanding, an Integrated Energy System Model (IESM) is being developed to simulate the physical and economic aspects of DER technologies, the buildings where they reside, and feeders servicing them. The IESM was used to simulate 20 houses with home energy management systems on a single feeder under a time-of-use (TOU) tariff to estimate economic and physical impacts on both the households and the distribution utilities. Home energy management systems (HEMS) reduce consumers’ electric bills by precooling houses in the hours before peak electricity pricing. Utilization of HEMS reduce peak loads during high price hours but shifts it to hours with off-peak and shoulder prices, resulting in a higher peak load. used to simulate 20 houses with home energy management systems on a single feeder under a time-of-use (TOU) tariff to estimate economic and physical impacts on both the households and the distribution utilities. Home energy management systems (HEMS) reduce consumers’ electric bills by precooling houses in the hours before peak electricity pricing. Utilization of HEMS reduce peak loads during high price hours but shifts it to hours with off-peak and shoulder prices, resulting in a higher peak load.

  16. Integrated simulation of snow and glacier melt in water and energy balance-based, distributed hydrological modeling framework at Hunza River Basin of Pakistan Karakoram region

    NASA Astrophysics Data System (ADS)

    Shrestha, Maheswor; Koike, Toshio; Hirabayashi, Yukiko; Xue, Yongkang; Wang, Lei; Rasul, Ghulam; Ahmad, Bashir

    2015-05-01

    Energy budget-based distributed modeling of snow and glacier melt runoff is essential in a hydrologic model to accurately describe hydrologic processes in cold regions and high-altitude catchments. We developed herein an integrated modeling system with an energy budget-based multilayer scheme for clean glaciers, a single-layer scheme for debris-covered glaciers, and multilayer scheme for seasonal snow over glacier, soil, and forest within a distributed biosphere hydrological modeling framework. Model capability is demonstrated for Hunza River Basin (13,733 km2) in the Karakoram region of Pakistan on a 500 m grid for 3 hydrologic years (2002-2004). Discharge simulation results show good agreement with observations (Nash-Sutcliffe efficiency = 0.93). Flow composition analysis reveals that the runoff regime is strongly controlled by the snow and glacier melt runoff (50% snowmelt and 33% glacier melt). Pixel-by-pixel evaluation of the simulated spatial distribution of snow-covered area against Moderate Resolution Imaging Spectroradiometer-derived 8 day maximum snow cover extent data indicates that the areal extent of snow cover is reproduced well, with average accuracy 84% and average absolute bias 7%. The 3 year mean value of net mass balance (NMB) was estimated at +0.04 myr-1. It is interesting that individual glaciers show similar characteristics of NMB over 3 years, suggesting that both topography and glacier hypsometry play key roles in glacier mass balance. This study provides a basis for potential application of such an integrated model to the entire Hindu-Kush-Karakoram-Himalaya region toward simulating snow and glacier hydrologic processes within a water and energy balance-based, distributed hydrological modeling framework.

  17. Quasi-linear simulations of inner radiation belt electron pitch angle and energy distributions

    NASA Astrophysics Data System (ADS)

    Albert, Jay M.; Starks, Michael J.; Horne, Richard B.; Meredith, Nigel P.; Glauert, Sarah A.

    2016-03-01

    "Peculiar" or "butterfly" electron pitch angle distributions (PADs), with minima near 90°, have recently been observed in the inner radiation belt. These electrons are traditionally treated by pure pitch angle diffusion, driven by plasmaspheric hiss, lightning-generated whistlers, and VLF transmitter signals. Since this leads to monotonic PADs, energy diffusion by magnetosonic waves has been proposed to account for the observations. We show that the observed PADs arise readily from two-dimensional diffusion at L = 2, with or without magnetosonic waves. It is necessary to include cross diffusion, which accounts for the relationship between pitch angle and energy changes. The distribution of flux with energy is also in good agreement with observations between 200 keV and 1 MeV, dropping to very low levels at higher energy. Thus, at this location radial diffusion may be negligible at subrelativistic as well as ultrarelativistic energy.

  18. Analysis of dose-LET distribution in the human body irradiated by high energy hadrons.

    PubMed

    Sato, T; Tsuda, S; Sakamoto, Y; Yamaguchi, Y; Niita, K

    2003-01-01

    For the purposes of radiological protection, it is important to analyse profiles of the particle field inside a human body irradiated by high energy hadrons, since they can produce a variety of secondary particles which play an important role in the energy deposition process, and characterise their radiation qualities. Therefore Monte Carlo calculations were performed to evaluate dose distributions in terms of the linear energy transfer of ionising particles (dose-LET distribution) using a newly developed particle transport code (Particle and Heavy Ion Transport code System, PHITS) for incidences of neutrons, protons and pions with energies from 100 MeV to 200 GeV. Based on these calculations, it was found that more than 80% and 90% of the total deposition energies are attributed to ionisation by particles with LET below 10 keV microm(-1) for the irradiations of neutrons and the charged particles, respectively. PMID:14653335

  19. Surface anisotropy broadening of the energy barrier distribution in magnetic nanoparticles.

    PubMed

    Pérez, N; Guardia, P; Roca, A G; Morales, M P; Serna, C J; Iglesias, O; Bartolomé, F; García, L M; Batlle, X; Labarta, A

    2008-11-26

    The effect of surface anisotropy on the distribution of energy barriers in magnetic fine particles of nanometer size is discussed within the framework of the Tln(t/τ(0)) scaling approach. The comparison between the distributions of the anisotropy energy of the particle cores, calculated by multiplying the volume distribution by the core anisotropy, and of the total anisotropy energy, deduced by deriving the master curve of the magnetic relaxation with respect to the scaling variable Tln(t/τ(0)), enables the determination of the surface anisotropy as a function of the particle size. We show that the contribution of the particle surface to the total anisotropy energy can be well described by a size-independent value of the surface energy per unit area which permits the superimposition of the distributions corresponding to the particle core and effective anisotropy energies. The method is applied to a ferrofluid composed of non-interacting Fe(3-x)O(4) particles of 4.9 nm average size and x about 0.07. Even though the size distribution is quite narrow in this system, a relatively small value of the effective surface anisotropy constant K(s) = 2.9 × 10(-2) erg cm(-2) gives rise to a dramatic broadening of the total energy distribution. The reliability of the average value of the effective anisotropy constant, deduced from magnetic relaxation data, is verified by comparing it to that obtained from the analysis of the shift of the ac susceptibility peaks as a function of the frequency. PMID:21836285

  20. A Multiple Period Problem in Distributed Energy Management Systems Considering CO2 Emissions

    NASA Astrophysics Data System (ADS)

    Muroda, Yuki; Miyamoto, Toshiyuki; Mori, Kazuyuki; Kitamura, Shoichi; Yamamoto, Takaya

    Consider a special district (group) which is composed of multiple companies (agents), and where each agent responds to an energy demand and has a CO2 emission allowance imposed. A distributed energy management system (DEMS) optimizes energy consumption of a group through energy trading in the group. In this paper, we extended the energy distribution decision and optimal planning problem in DEMSs from a single period problem to a multiple periods one. The extension enabled us to consider more realistic constraints such as demand patterns, the start-up cost, and minimum running/outage times of equipment. At first, we extended the market-oriented programming (MOP) method for deciding energy distribution to the multiple periods problem. The bidding strategy of each agent is formulated by a 0-1 mixed non-linear programming problem. Secondly, we proposed decomposing the problem into a set of single period problems in order to solve it faster. In order to decompose the problem, we proposed a CO2 emission allowance distribution method, called an EP method. We confirmed that the proposed method was able to produce solutions whose group costs were close to lower-bound group costs by computational experiments. In addition, we verified that reduction in computational time was achieved without losing the quality of solutions by using the EP method.

  1. Correlation energy, structure factor, radial distribution function, and momentum distribution of the spin-polarized uniform electron gas

    NASA Astrophysics Data System (ADS)

    Ortiz, G.; Ballone, P.

    1994-07-01

    The properties of the three-dimensional uniform electron gas in the Fermi liquid regime are analyzed using variational Monte Carlo (VMC) and fixed-node diffusion Monte Carlo methods. Our study extends those of Ceperley [Phys. Rev. B 18, 3126 (1978)] and Ceperley and Alder [Phys. Rev. Lett. 45, 566 (1980)] to larger system sizes with improved statistics and, more importantly, to partial spin polarization. The density range 0.8<=rs<=10, which is the most relevant for density functional computations, is studied in detail. We analyze the size dependence of the simulation results and present an extended set of correlation energies extrapolated to the thermodynamic limit. Using the VMC method we analyze the spin dependence of the correlation energy, and we compare our results to several interpolation formulas used in density functional calculations. We summarize our results by a simple interpolation formula. In addition, we present results for the radial distribution function, the structure factor, the momentum distribution, and triplet correlation functions, and we discuss the comparison with many-body semianalytic theories.

  2. The Electromotive Series and Other Non-Absolute Scales

    NASA Astrophysics Data System (ADS)

    Peckham, Gavin D.

    1998-01-01

    This article describes an analogy which may be used to illustrate the principles that underlie the establishment of non-absolute scales of measurements that are evaluated relative to a chosen reference point. The analogy is interwoven with the establishment of the electromotive series, but may be extended to other parameters such as the Celsius and Fahrenheit temperature scales, potential energies, formation and reaction enthalpies, etc.

  3. Absolute magnitudes of trans-neptunian objects

    NASA Astrophysics Data System (ADS)

    Duffard, R.; Alvarez-candal, A.; Pinilla-Alonso, N.; Ortiz, J. L.; Morales, N.; Santos-Sanz, P.; Thirouin, A.

    2015-10-01

    Accurate measurements of diameters of trans- Neptunian objects are extremely complicated to obtain. Radiomatric techniques applied to thermal measurements can provide good results, but precise absolute magnitudes are needed to constrain diameters and albedos. Our objective is to measure accurate absolute magnitudes for a sample of trans- Neptunian objects, many of which have been observed, and modelled, by the "TNOs are cool" team, one of Herschel Space Observatory key projects grantes with ~ 400 hours of observing time. We observed 56 objects in filters V and R, if possible. These data, along with data available in the literature, was used to obtain phase curves and to measure absolute magnitudes by assuming a linear trend of the phase curves and considering magnitude variability due to rotational light-curve. In total we obtained 234 new magnitudes for the 56 objects, 6 of them with no reported previous measurements. Including the data from the literature we report a total of 109 absolute magnitudes.

  4. A New Gimmick for Assigning Absolute Configuration.

    ERIC Educational Resources Information Center

    Ayorinde, F. O.

    1983-01-01

    A five-step procedure is provided to help students in making the assignment absolute configuration less bothersome. Examples for both single (2-butanol) and multi-chiral carbon (3-chloro-2-butanol) molecules are included. (JN)

  5. Observation of nonthermal energy distributions during the impulsive phase of solar flares

    NASA Technical Reports Server (NTRS)

    Seely, J. F.; Feldman, U.; Doschek, G. A.

    1987-01-01

    The Fe XXV resonance line and dielectronic satellite intensities have been measured as functions of time for several flares recorded by the Naval Research Laboratory crystal spectrometer (SOLFLEX) flown on the US Air Force P78-I spacecraft. The intensity ratios of the Fe XXV resonance line, the Fe XXIV n = 2 satellite line j, and the Fe XXIV n = 3 satellite line d13 indicate that nonthermal electron energy distributions occur during the impulsive phase of the flares. For the electron energies at which the j and d13 satellites are formed (4.7 and 5.8 keV, respectively), the electron energy distributions during the impulsive phase are observed to have a bump or to be nearly flat. For all of the flares that were studied, hard X-ray bursts occurred near the time of the nonthermal distributions observed in the SOLFLEX data.

  6. Analysis of electron energy distribution function in the Linac4 H⁻ source.

    PubMed

    Mochizuki, S; Mattei, S; Nishida, K; Hatayama, A; Lettry, J

    2016-02-01

    To understand the Electron Energy Distribution Function (EEDF) in the Radio Frequency Inductively Coupled Plasmas (RF-ICPs) in hydrogen negative ion sources, the detailed analysis of the EEDFs using numerical simulation and the theoretical approach based on Boltzmann equation has been performed. It is shown that the EEDF of RF-ICPs consists of two parts, one is the low energy part which obeys Maxwellian distribution and the other is high energy part deviated from Maxwellian distribution. These simulation results have been confirmed to be reasonable by the analytical approach. The results suggest that it is possible to enhance the dissociation of molecules and the resultant H(-) negative ion production by reducing the gas pressure. PMID:26931990

  7. Retarding field analyzer for ion energy distribution measurements at a radio-frequency biased electrode

    SciTech Connect

    Gahan, D.; Hopkins, M. B.; Dolinaj, B.

    2008-03-15

    A retarding field energy analyzer designed to measure ion energy distributions impacting a radio-frequency biased electrode in a plasma discharge is examined. The analyzer is compact so that the need for differential pumping is avoided. The analyzer is designed to sit on the electrode surface, in place of the substrate, and the signal cables are fed out through the reactor side port. This prevents the need for modifications to the rf electrode--as is normally the case for analyzers built into such electrodes. The capabilities of the analyzer are demonstrated through experiments with various electrode bias conditions in an inductively coupled plasma reactor. The electrode is initially grounded and the measured distributions are validated with the Langmuir probe measurements of the plasma potential. Ion energy distributions are then given for various rf bias voltage levels, discharge pressures, rf bias frequencies - 500 kHz to 30 MHz, and rf bias waveforms - sinusoidal, square, and dual frequency.

  8. Development, Demonstration, and Field Testing of Enterprise-Wide Distributed Generation Energy Management System: Final Report

    SciTech Connect

    Greenberg, S.; Cooley, C.

    2005-01-01

    This report details progress on subcontract NAD-1-30605-1 between the National Renewable Energy Laboratory and RealEnergy (RE), the purpose of which is to describe RE's approach to the challenges it faces in the implementation of a nationwide fleet of clean cogeneration systems to serve contemporary energy markets. The Phase 2 report covers: utility tariff risk and its impact on market development; the effect on incentives on distributed energy markets; the regulatory effectiveness of interconnection in California; a survey of practical field interconnection issues; trend analysis for on-site generation; performance of dispatch systems; and information design hierarchy for combined heat and power.

  9. Initial energy density and gluon distribution from the glasma in heavy-ion collisions

    NASA Astrophysics Data System (ADS)

    Fujii, Hirotsugu; Fukushima, Kenji; Hidaka, Yoshimasa

    2009-02-01

    We estimate the energy density and the gluon distribution associated with the classical fields describing the early-time dynamics of heavy-ion collisions. In the McLerran-Venugopalan model, we first decompose the energy density into the momentum components exactly, with the use of the Wilson line correlators. Then we evolve the energy density with the free-field equation, which is justified by the dominance of the ultraviolet modes near the collision point. We also discuss the improvement that occurs with the inclusion of nonlinear terms into the time evolution. Our numerical results at RHIC energy are fairly consistent with the empirical values.

  10. Initial energy density and gluon distribution from the glasma in heavy-ion collisions

    SciTech Connect

    Fujii, Hirotsugu; Fukushima, Kenji; Hidaka, Yoshimasa

    2009-02-15

    We estimate the energy density and the gluon distribution associated with the classical fields describing the early-time dynamics of heavy-ion collisions. In the McLerran-Venugopalan model, we first decompose the energy density into the momentum components exactly, with the use of the Wilson line correlators. Then we evolve the energy density with the free-field equation, which is justified by the dominance of the ultraviolet modes near the collision point. We also discuss the improvement that occurs with the inclusion of nonlinear terms into the time evolution. Our numerical results at RHIC energy are fairly consistent with the empirical values.

  11. Experimental electron energy distribution function investigation at initial stage of electron cyclotron resonance discharge

    SciTech Connect

    Golubev, S. V.; Izotov, I. V.; Mansfeld, D. A.; Semenov, V. E.

    2012-02-15

    Experimental investigation is undertaken to study formation of electron energy distribution function (EEDF) at the initial stage of electron cyclotron resonance (ECR) discharge inside magnetic mirror trap. In experiment, where discharge was initiated by high power radiation of gyrotron operated in the mm-wavelength range, electrons were revealed to leave the trap having EEDF be quite different from Maxwellian one. Specifically, the EEDF was found to decrease slowly with energy up to 400-500 keV and drops abruptly further. The possible physical mechanisms are discussed to explain losses of high energy electrons from the trap and a limitation of their energy.

  12. Experimental electron energy distribution function investigation at initial stage of electron cyclotron resonance discharge.

    PubMed

    Golubev, S V; Izotov, I V; Mansfeld, D A; Semenov, V E

    2012-02-01

    Experimental investigation is undertaken to study formation of electron energy distribution function (EEDF) at the initial stage of electron cyclotron resonance (ECR) discharge inside magnetic mirror trap. In experiment, where discharge was initiated by high power radiation of gyrotron operated in the mm-wavelength range, electrons were revealed to leave the trap having EEDF be quite different from Maxwellian one. Specifically, the EEDF was found to decrease slowly with energy up to 400-500 keV and drops abruptly further. The possible physical mechanisms are discussed to explain losses of high energy electrons from the trap and a limitation of their energy. PMID:22380303

  13. The writhe distribution in DNA plasmids as derived from the free energy of supercoiling

    NASA Astrophysics Data System (ADS)

    Tobias, Irwin

    2000-10-01

    In theoretical work on the molecule, DNA is often treated, approximately, as a naturally straight, inextensible, isotropic elastic rod of circular cross section. It is shown that, consistent with this level of approximation, there exists a general connection between the free energy of supercoiling of plasmids formed by the DNA, and the writhe distribution in plasmids having a given value of the linking number difference, ΔLk. In particular, the writhe distribution in a collection of torsionally relaxed (ΔLk=0), but non-nicked, plasmids is completely determined once the free energy of supercoiling as a function of ΔLk is known. The writhe distribution in the supercoiled plasmids characterized by any other value of ΔLk, we shall also show, is simply related to the distribution in the relaxed plasmid, and, therefore, it, too, is completely determined. These general results are illustrated for two cases: Large plasmids for which the measured free energy of supercoiling, a quadratic function of ΔLk, implies a normal writhe distribution, and miniplasmids for which a theoretical expression for the free energy of supercoiling involving the frequencies of the normal modes of vibration of a circular elastic ring has recently become available. In this latter case, the writhe distribution for supercoiled plasmids is not normal, but shows a skewness related to a property of elastic rings, namely, the loss of stability of the circular equilibrium configuration of the rings when they are twisted beyond a critical value. Such a skewed writhe distribution for miniplasmids is, according to the model, associated with a free energy of supercoiling which is not, as has been assumed, a rigorously quadratic function of ΔLk.

  14. Evaluation of eruptive energy of a pyroclastic deposit applying fractal geometry to fragment size distributions

    NASA Astrophysics Data System (ADS)

    Paredes Marino, Joali; Morgavi, Daniele; Di Vito, Mauro; de Vita, Sandro; Sansivero, Fabio; Perugini, Diego

    2016-04-01

    Fractal fragmentation theory has been applied to characterize the particle size distribution of pyroclastic deposits generated by volcanic explosions. Recent works have demonstrated that fractal dimension on grain size distributions can be used as a proxy for estimating the energy associated with volcanic eruptions. In this work we seek to establish a preliminary analytical protocol that can be applied to better characterize volcanic fall deposits and derive the potential energy for fragmentation that was stored in the magma prior/during an explosive eruption. The methodology is based on two different techniques for determining the grain-size distribution of the pyroclastic samples: 1) dry manual sieving (particles larger than 297μm), and 2) automatic grain size analysis via a CamSizer-P4®device, the latter measure the distribution of projected area, obtaining a cumulative distribution based on volume fraction for particles up to 30mm. Size distribution data have been analyzed by applying the fractal fragmentation theory estimating the value of Df, i.e. the fractal dimension of fragmentation. In order to test our protocol we studied the Cretaio eruption, Ischia island, Italy. Results indicate that size distributions of pyroclastic fall deposits follow a fractal law, indicating that the fragmentation process of these deposits reflects a scale-invariant fragmentation mechanism. Matching the results from manual and automated techniques allows us to obtain a value of the "fragmentation energy" from the explosive eruptive events that generate the Cretaio deposits. We highlight the importance of these results, based on fractal statistics, as an additional volcanological tool for addressing volcanic risk based on the analyses of grain size distributions of natural pyroclastic deposits. Keywords: eruptive energy, fractal dimension of fragmentation, pyroclastic fallout.

  15. Using field emission to control the electron energy distribution in high-pressure microdischarges at microscale dimensions

    SciTech Connect

    Li, Yingjie; Go, David B.

    2013-12-02

    Particle simulations of high-pressure microdischarges at gaps below 10 μm show that the electron energy distribution becomes non-continuous, with discrete peaks corresponding to specific inelastic collisions. The relative magnitude of these peaks and shape of the energy distribution can be directly controlled by the parameter pressure times distance (pd) and the applied potential across the gap. These parameters dictate inelastic collisions experienced by electrons and as both increase the distribution smooths into a Maxwellian-like distribution. By capitalizing on field emission at these dimensions, it is possible to control the energy distribution of free electrons to target specific, energy dependent reactions.

  16. Modeling of thermal storage systems in MILP distributed energy resource models

    SciTech Connect

    Steen, David; Stadler, Michael; Cardoso, Gonçalo; Groissböck, Markus; DeForest, Nicholas; Marnay, Chris

    2014-08-04

    Thermal energy storage (TES) and distributed generation technologies, such as combined heat and power (CHP) or photovoltaics (PV), can be used to reduce energy costs and decrease CO2 emissions from buildings by shifting energy consumption to times with less emissions and/or lower energy prices. To determine the feasibility of investing in TES in combination with other distributed energy resources (DER), mixed integer linear programming (MILP) can be used. Such a MILP model is the well-established Distributed Energy Resources Customer Adoption Model (DER-CAM); however, it currently uses only a simplified TES model to guarantee linearity and short run-times. Loss calculations are based only on the energy contained in the storage. This paper presents a new DER-CAM TES model that allows improved tracking of losses based on ambient and storage temperatures, and compares results with the previous version. A multi-layer TES model is introduced that retains linearity and avoids creating an endogenous optimization problem. The improved model increases the accuracy of the estimated storage losses and enables use of heat pumps for low temperature storage charging. Ultimately,results indicate that the previous model overestimates the attractiveness of TES investments for cases without possibility to invest in heat pumps and underestimates it for some locations when heat pumps are allowed. Despite a variation in optimal technology selection between the two models, the objective function value stays quite stable, illustrating the complexity of optimal DER sizing problems in buildings and microgrids.

  17. The global distribution of gravity wave energy in the lower stratosphere derived from GPS data and gravity wave modelling: Attempt and challenges

    NASA Astrophysics Data System (ADS)

    Fröhlich, K.; Schmidt, T.; Ern, M.; Preusse, P.; de La Torre, A.; Wickert, J.; Jacobi, Ch.

    2007-12-01

    Five years of global temperatures retrieved from radio occultations measured by Champ (Challenging Minisatellite Payload) and SAC-C (Satelite de Aplicaciones Cientificas-C) are analyzed for gravity waves (GWs). In order to separate GWs from other atmospheric variations, a high-pass filter was applied on the vertical profile. Resulting temperature fluctuations correspond to vertical wavelengths between 400 m (instrumental resolution) and 10 km (limit of the high-pass filter). The temperature fluctuations can be converted into GW potential energy, but for comparison with parameterization schemes GW momentum flux is required. We therefore used representative values for the vertical and horizontal wavelength to infer GW momentum flux from the GPS measurements. The vertical wavelength value is determined by high-pass filtering, the horizontal wavelength is adopted from a latitude-dependent climatology. The obtained momentum flux distributions agree well, both in global distribution and in absolute values, with simulations using the Warner and McIntyre parameterization (WM) scheme. However, discrepancies are found in the annual cycle. Online simulations, implementing the WM scheme in the mechanistic COMMA-LIM (Cologne Model of the Middle Atmosphere—Leipzig Institute for Meteorology) general circulation model (GCM), do not converge, demonstrating that a good representation of GWs in a GCM requires both a realistic launch distribution and an adequate representation of GW breaking and momentum transfer.

  18. Observations of the directional distribution of the wind energy input function over swell waves

    NASA Astrophysics Data System (ADS)

    Shabani, Behnam; Babanin, Alex V.; Baldock, Tom E.

    2016-02-01

    Field measurements of wind stress over shallow water swell traveling in different directions relative to the wind are presented. The directional distribution of the measured stresses is used to confirm the previously proposed but unverified directional distribution of the wind energy input function. The observed wind energy input function is found to follow a much narrower distribution (β∝cos⁡3.6θ) than the Plant (1982) cosine distribution. The observation of negative stress angles at large wind-wave angles, however, indicates that the onset of negative wind shearing occurs at about θ≈ 50°, and supports the use of the Snyder et al. (1981) directional distribution. Taking into account the reverse momentum transfer from swell to the wind, Snyder's proposed parameterization is found to perform exceptionally well in explaining the observed narrow directional distribution of the wind energy input function, and predicting the wind drag coefficients. The empirical coefficient (ɛ) in Snyder's parameterization is hypothesised to be a function of the wave shape parameter, with ɛ value increasing as the wave shape changes between sinusoidal, sawtooth, and sharp-crested shoaling waves.

  19. Finite-temperature local protein sequence alignment: percolation and free-energy distribution.

    PubMed

    Wolfsheimer, S; Melchert, O; Hartmann, A K

    2009-12-01

    Sequence alignment is a tool in bioinformatics that is used to find homological relationships in large molecular databases. It can be mapped on the physical model of directed polymers in random media. We consider the finite-temperature version of local sequence alignment for proteins and study the transition between the linear phase and the biologically relevant logarithmic phase, where the free energy grows linearly or logarithmically with the sequence length. By means of numerical simulations and finite-size-scaling analysis, we determine the phase diagram in the plane that is spanned by the gap costs and the temperature. We use the most frequently used parameter set for protein alignment. The critical exponents that describe the parameter-driven transition are found to be explicitly temperature dependent. Furthermore, we study the shape of the (free-) energy distribution close to the transition by rare-event simulations down to probabilities on the order 10(-64). It is well known that in the logarithmic region, the optimal score distribution (T=0) is described by a modified Gumbel distribution. We confirm that this also applies for the free-energy distribution (T>0). However, in the linear phase, the distribution crosses over to a modified Gaussian distribution. PMID:20365196

  20. PHEV Energy Use Estimation: Validating the Gamma Distribution for Representing the Random Daily Driving Distance

    SciTech Connect

    Lin, Zhenhong; Dong, Jing; Liu, Changzheng; Greene, David L

    2012-01-01

    The petroleum and electricity consumptions of plug-in hybrid electric vehicles (PHEVs) are sensitive to the variation of daily vehicle miles traveled (DVMT). Some studies assume DVMT to follow a Gamma distribution, but such a Gamma assumption is yet to be validated. This study finds the Gamma assumption valid in the context of PHEV energy analysis, based on continuous GPS travel data of 382 vehicles, each tracked for at least 183 days. The validity conclusion is based on the found small prediction errors, resulting from the Gamma assumption, in PHEV petroleum use, electricity use, and energy cost. The finding that the Gamma distribution is valid and reliable is important. It paves the way for the Gamma distribution to be assumed for analyzing energy uses of PHEVs in the real world. The Gamma distribution can be easily specified with very few pieces of driver information and is relatively easy for mathematical manipulation. Given the validation in this study, the Gamma distribution can now be used with better confidence in a variety of applications, such as improving vehicle consumer choice models, quantifying range anxiety for battery electric vehicles, investigating roles of charging infrastructure, and constructing online calculators that provide personal estimates of PHEV energy use.