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... 1-sigma ZOHF pixel-to-plxel statistical fluctuations ... Spatial frequency filtering shows distinct bands, but miss ... LOS emissivity at the point of closest ...

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The expression C/sub FB/ = C/sub ox/ x ({element of}/sub si//L/sub D/)/(C/sub ox/ + ({Epsilon}/sub si//L/sub D/)) (where L/sub D/ is the Debye length), commonly used for the flat-band capacitance of the MOS structure, is invalid in the temperature range below 100 {Kappa}. Consequently, significant error may be encountered when the flat-band capacitance method is used to extract the flat-band voltage V/sub FB/, which is of considerable interest for both the modeling and characterization of MOS devices. To extend this method to low-temperature CMOS applications one has to use a more general model that can be obtained by applying Fermi-Dirac statistics and taking into account the impurity freezeout effect. The authors show that when the temperature dependence of V/sub FB/ is extracted using this approach, the experimental data for n/sup +/ polysilicon gate MOS ...

CERN Document Server

Multiparametric Statistics

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Science.gov (United States)

Nonparabolicity of the heavy hole band in diamond-like semiconductors, which occurs within the framework of the three band model with the perturbation from the other bands taken into account according to the Loewdin procedure, is studied. A direct dependence of nonparabolicity on the band anisotropy (caused by the different effect of Gamma/sub 15c/ and Gamma/sub 12c/ bands) and the inverse dependence on the magnitude of the spin-orbit splittiing is established. A connection between the effective mass of heavy holes and their energy is obtained, which is valid for the majority of diamond-like semiconductors, except for materials with a very strong nonparabolicity of the band of silicon type

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Lifetimes have been measured for a dipole band in {sup 139}Sm using DSAM. The deduced B(M1) and B(E2) values as well as B(M1)/B(E2) ratios are compared with calculations in the framework of the TAC (Tilted Axis Cranking) and SPAC (Shears mechanism with Principal Axis Cranking) models. The dipole band in {sup 139}Sm can be considered as a magnetic rotational band with a prolate or triaxial nuclear deformation. (orig.)

CERN Document Server

We search for an infrared signature of the transiting extrasolar planet HD 209458b during secondary eclipse. Our method, which we call `occultation spectroscopy,' searches for the disappearance and reappearance of weak spectral features due to the exoplanet as it passes behind the star and later reappears. We argue that at the longest infrared wavelengths, this technique becomes preferable to conventional `transit spectroscopy'. We observed the system in the wing of the strong nu-3 band of methane near 3.6 microns during two secondary eclipses, using the VLT/ISAAC spectrometer at a spectral resolution of 3300. Our analysis, which utilizes a model template spectrum, achieves sufficient precision to expect detection of the spectral structure predicted by an irradiated, low-opacity (cloudless), low-albedo, thermochemical equilibrium model for the exoplanet atmosphere. However, our observations show no evidence for the presence ...

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A statistical treatment has been applied to interpret the experimental data on the Xe M-shell vacancy production in slow 1.05 MeV Xe-Xe collisions and is shown to give better agreement with experiment than that of the molecular-orbital models.

UK PubMed Central (United Kingdom)

This paper presents a new deformable model using both population and patient-specific statistics to segment the prostate from CT images. There are two novelties in the proposed method. First,...Full Text Available

UK PubMed Central (United Kingdom)

We develop a statistical framework to study the relationship between chromatin features and gene expression. This can be used to predict gene expression of protein coding genes, as well as microRNAs....Full Text Available

CERN Document Server

RooStats is a project to create advanced statistical tools required for the analysis of LHC data, with emphasis on discoveries, confidence intervals, and combined measurements. The idea is to provide the major statistical techniques as a set of C++ classes with coherent interfaces, which can be used on arbitrary model and datasets in a common way. The classes are built on top of RooFit, which provides a very convenient functionality for modeling the probability density functions or the likelihood functions, required as inputs for any statistical technique. Furthermore, RooFit provides the functionality for easily creating models, for analysis combination and for digital publication of the likelihood function and the data. We will present in detail the design and the implementation of the different statistical methods of RooStats. These ...

CERN Document Server

Nonequilibrium statistical mechanics

UK PubMed Central (United Kingdom)

BackgroundLiquid chromatography-mass spectrometry (LC-MS) is one of the major techniques for the quantification of metabolites in complex biological samples. Peak modeling is one...Full Text Available

International Nuclear Information System (INIS)

Active galactic nuclei (AGNs) and quasars (QSOs) appear to emit roughly equal energy per decade from radio to gamma-ray energies (e.g. Ramaty and Ligenfelter 1982). This argues strongly for a nonthermal radiation mechanism (see Rees 1984). In addition, statistical studies have indicated that the spectra of these objects in the IR-UV and 2 to 50 keV x-ray band, can be fitted very well with power laws of specific indices. These spectral indices do not seem to depend on the luminosity or morphology of the objects (Rothschild et al. 1983; Malkan 1984), and any theory should account for them in a basic and model independent way. If shocks accelerate relativistic protons via the first-order Fermi mechanism (e.g. Axfor 1981), the radiating electrons can be produced as secondaries throughout the source by proton-proton (p-p) collisions and pion decay, thus eliminating Compton losses (Protheroe and Kazanas 1983). As shown by Kazanas ...

Science.gov (United States)

The Advanced Statistical Trajectory Regional Air Pollution (ASTRAP) model simulates long-term transport and deposition of oxides of and nitrogen. t is a potential screening tool for assessing long-term effects on regional visibility from sulfur emission sources. owever, a rigorou...

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High-spin states in the neutron-rich nuclei {sup 172,173}Yb have been populated in a {sup 170}Er({sup 7}Li,(p,d,t)xn) incomplete-fusion reaction and the emitted {gamma}-radiation was detected with the GASP array. The signature partners of the 7/2{sup +}[633] rotational band of the odd-N {sup 173}Yb isotope have been newly established and were observed up to spin values of (45/2{sup +}) and (43/2{sup +}), respectively. The ground-state band of the even-even nucleus {sup 172}Yb has been observed up to a spin value of (22{sup +}). No band crossings were found in these bands. To explain this observation, it is proposed that the static pair field is absent, considering that the neutron odd-even mass differences reach for these nuclei very small values and that the band crossing is absent in cranked shell modell calculations without pairing. The results indicate, ...

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The paper presents cloud structure models for Jupiter's Great Red Spot, Equatorial and North Tropical Zones, North and South Temperate Zones, and North and South Polar Regions. The models are based on images of Jupiter in three methane bands and nearby continuum radiative transfer calculations include multiple scattering and absorption from three aerosol layers. The model results include the transition in the upper-cloud altitude to 3 km lower altitude from the tropical zones to temperate zones and polar regions, a N/S asymmetry in cloud thickness in the tropical and temperature zones, and the presence of aerosols up to about 0.3 bar in the Great Red Spot and Equatorial Zone. It is concluded that polarization data are sensitive to aerosols in and above the upper cloud layer but insensitive to deeper cloud structure.

International Nuclear Information System (INIS)

Nonrelativistic band calculations of Mattheiss for Nb and Petroff and Viswanathan for Mo are used to calculate the imaginary part epsilon_2 of the dielectric function for these metals. The structure resulting from interband transitions in the frequency range 0.1--0.5 Ry is found to give fairly good agreement with experiment. The calculation indicates that structure in epsilon_2 can arise from transitions away from symmetry points and lines in the Brillouin zone. The difficulty in distinguishing between the direct and indirect transition models for epsilon_2 is shown to arise from a lack of strong optical critical points. Predictions of the rigid-band model for the optical properties of Nb-Mo alloys are presented.

CERN Document Server

The present thesis is concerned with the local quantum physics of relativistic particles and fields in three space-time dimensions, whose statistics is to be described by a representation of the braid group -- so-called plektons or, if the representation is Abelian, anyons. In particular the issue of the existence of free anyonic fields is addressed. In our context, these are operators affiliated with the 'local' field algebras and creating only single particle vectors from the vacuum. (Localizability here refers to regions extending to infinity in some spacelike direction.) Under a mild regularity condition for these fields, we can derive commutation relations which are not compatible with braid group statistics. Further, model-independent results concerning the PCT operator and the connection of spin and statistics are obtained. Assuming the observable algebra to satisfy the Bisognano-Wichmann ...

CERN Document Server

Statistical Analysis of Designed Experiments

CERN Document Server

Choosing and Using Statistics

British Library Electronic Table of Contents (United Kingdom)

Abstract Electronic structures of two representative zigzag and armchair models of aluminum phosphide nanotube (AlPNT) were investigated by density functional theory calculations. The structures were optimized and the bond lengths, tip diameters, band gaps, and dipole moments were calculated. Moreover, the quadrupole coupling constants (CQ) were calculated for the Al-27 atoms of the optimized structures. The same values of AlP bond lengths were calculated for both models. The larger value of band gap of armchair model than the zigzag model indicated the stronger dielectric property for the former model. The values of CQ(27Al) were the largest for the Al atoms placed at the tips of both zigzag and armchair AlPNT than other Al atoms, which could reveal dominant role of the Al atoms placed at...

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This paper investigates the calculation of availability for parallel transmission lines (two or more) in the same tower or on the same right of way. As in many studies, the development of mathematical models is an important step. The models are justified using historical data and known characteristics of power system elements. A statistical method was used to generalize the failure rate and repair rate from real operating data. Application of the new model (which combines common-mode, simultaneous independent, and dependent outages) is discussed.

UK PubMed Central (United Kingdom)

Previous studies of insect flight control have been statistical in approach, simply correlating wing kinematics with body kinematics or force production. Kinematics and forces are linked by Newtonian...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

High-spin states in {sup 177}Ta were produced using the {sup 170}Er({sup 11}B, 4{ital n}) reaction at 55 and 60 MeV. Considerable extensions have been made to the previously known level scheme, and new structures have been found. {ital B}({ital M}1)/{ital B}({ital E}2) ratios have been extracted for strongly coupled bands. The behavior of the different rotational cascades, in particular the anomalous crossing frequency observed in the [541]1/2{sup {minus}} proton {ital h}{sub 9/2} band and the occurrence of ``identical bands,`` is discussed. Comparisons are made with projected shell model calculations.

International Nuclear Information System (INIS)

Excited states in the T_z=(1/2) nucleus "8"5Mo have been observed for the first time with the reaction "5"8Ni("3"2S,#alpha#n#gamma#) at 105 MeV. #gamma#-ray transitions in this nucleus have been assigned unambiguously by combining the information from the GASP #gamma#-ray array, the ISIS silicon ball, and the n-Ring neutron detector. Two band structures have been observed in this nucleus; they continue the smooth evolution of the known bands from the lighter N=43 isotones and have been tentatively assigned spins and parity on this basis. After reaching a maximum of collectivity at "8"3Zr, the trend with increasing mass is reversed, showing a smaller collectivity at "8"5Mo. The rotational behavior of the observed bands is discussed on the basis of the projected shell model calculations.

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A pillbox RF output window was developed for the L-band pulsed klystron for the Japanese Hadron Project (JHP) 1-GeV proton linac. The window was designed to withstand a peak RF power of 6 MW, where the pulse width is 600 {mu}sec and the repetition rate is 50 Hz. A high power model was fabricated using an alumina ceramic which has a low loss tangent of 2.5x10{sup -5}. A high power test was successfully performed up to a 113 kW RF average power with a 4 MW peak power, a 565 {mu}sec pulse width and a 50 Hz repetition rate. By extrapolating the data of this high power test, the temperature rise of the ceramic is estimated low enough at the full RF power of 6 MW. Thus this RF window is expected to satisfy the specifications of the L-band Klystron. (author).

CERN Document Server

Proteins are polymers of amino acids. These macromolecules are synthesized by intracellular machines called {\\it ribosome}. Although, traditionally, the experimental investigation of protein synthesis has been an active area of research in molecular cell biology, important quantitative models of this phenomenon have been reported mostly in the research journals devoted to statistical physics and related interdisciplinary topics. From the perspective of a physicist, protein synthesis is a phenomenon of {\\it classical transport of interacting ribosomes on a messenger RNA (mRNA) template} that dictates the sequence of the amino acids on the protein. Here we bring this frontier area of contemporary research into the classroom by appropriate simplification of the models and methods. In particular, we develope a simple toy model and analyze it by some elementary techniques of non-equilibrium ...

Science.gov (United States)

This paper applies White's (1982, Econometrica 50, 1-25) information matrix (IM) test for correct model specification to proportional hazards models of univariate and multivariate censored survival data. Several alternative estimators of the test statistic are presented and their size performance examined. White also suggested an estimator of the parameter covariance matrix that was robust to certain forms of model misspecification. This has been subsequently proposed by others (e.g., Royall, 1986, International Statistical Review 54, 221-226) and applied by Huster, Brookmeyer, and Self (1989, Biometrics 45, 145-156) as part of an independence working model (IWM) approach to multivariate censored survival data. We illustrate how the IM test can be used for both univariate data and as part of the IWM approach to multivariate data. PMID:8117901

British Library Electronic Table of Contents (United Kingdom)

In the parametric regression model, the covariate missing problem under missing at random is considered. It is often desirable to use flexible parametric or semiparametric models for the covariate distribution, which can reduce a potential misspecification problem. Recently, a completely nonparametric approach was developed by [H.Y. Chen, Nonparametric and semiparametric models for missing covariates in parameter regression, J. Amer. Statist. Assoc. 99 (2004), pp. 1176-1189; Z. Zhang and H.E. Rockette, On maximum likelihood estimation in parametric regression with missing covariates, J. Statist. Plann. Inference 47 (2005), pp. 206-223]. Although it does not require a model for the covariate distribution or the missing data mechanism, the proposed method assumes that the covariate distribut...

CERN Document Server

Aims: I have analyzed a sample of seven nearby edge-on galaxies observed in the V and K'-band, in order to infer the properties of the dust distribution. Methods: A radiative transfer model, including scattering, have been used to decompose each image into a stellar disk, a bulge, and a dust disk. The parameters describing the distributions have been obtained through standard X^2 minimization techniques. Results: The dust disks fitted to the V-band images are consistent with previous work in literature: the radial scalelength of dust is larger than that for stars (h_d/h_s ~ 1.5); the dust disk has a smaller vertical scalelength than the stellar (z_d/z_s ~ 1/3); the dust disk is almost transparent when seen face-on (central, face-on, optical depth tau_0 =0.5-1.5). Faster radiative transfer models which neglect scattering can produce equivalent fits, with changes in the derived parameters within the ...

International Nuclear Information System (INIS)

We give a theoretical design for a locally resonant two-dimensional cylindrical structure involving a pair of C-shaped voids in an elastic medium which we term as double 'C' resonators (DCRs) and imbedded thin stiff bars, that displays the negative refraction effect in the low frequency regime. DCRs are responsible for a low frequency band gap which hybridizes with a tiny gap associated with the presence of the thin bars. Using an asymptotic analysis, typical working frequencies are given in closed form: DCRs behave as Helmholtz resonators modeled by masses connected to clamped walls by springs on either side, while thin bars behave as a periodic bi-atomic chain of masses connected by springs. The discrete models give an accurate description of the location and width of the stop band in the case of the DCR and the first two dispersion bands for the periodic thin bars. We then ...

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Fourier transform infrared absorption spectroscopy has been used for the determination of the line strengths of 41 CO and CO[sub 2] absorption lines at temperatures between 295 and 1250 K. The CO vibrational-rotational lines were from the [ital P] branch of the fundamental absorption band (2150--1950 cm[sup [minus]1]) while the CO[sub 2] vibrational-rotational lines were from the far wing of the [ital R] branch of the [nu][sub 3] fundamental band (2395--2380 cm[sup [minus]1]). The intensities of the lines were measured from absorption spectra recorded in a high-temperature gas cell containing known concentrations of CO/CO[sub 2]/N[sub 2] gas mixtures at atmospheric pressure. Absorption spectra were recorded through the cell with the use of a moderate-resolution Fourier transform infrared spectrometer. The absorption spectra were mathematically corrected for distortions resulting from the finite resolution of the spectrometer and for peak ...

CERN Document Server

Suppose we would like to know all answers to a set of statistical queries C on a data set up to small error, but we can only access the data itself using statistical queries. A trivial solution is to exhaustively ask all queries in C. Can we do any better? + We show that the number of statistical queries necessary and sufficient for this task is---up to polynomial factors---equal to the agnostic learning complexity of C in Kearns' statistical query (SQ) model. This gives a complete answer to the question when running time is not a concern. + We then show that the problem can be solved efficiently (allowing arbitrary error on a small fraction of queries) whenever the answers to C can be described by a submodular function. This includes many natural concept classes, such as graph cuts and Boolean disjunctions and conjunctions. In doing so we also give a new learning algorithm for ...

International Nuclear Information System (INIS)

The governor model is extended to include the asymmetric shape of nuclei which allows a simultaneous analysis of the data for both the ground state and the #gamma#-vibrational bands in deformed even-even nuclei. The rotationally invariant core is assumed to be a spheroid with an axis of symmetry parallel to the axis of rotation. The calculations are carried out under the assumption of no stretching. The static #gamma#-deformation results are compared with the VMI(ARM) and Krutov values, and the calculated energies are in good agreement with the experimental data.

International Nuclear Information System (INIS)

Experiments on the depth dependence of transient enhanced diffusion (TED) of boron during rapid thermal annealing of Ge-preamorphized layers reveal a linear decrease in the diffusion enhancement between the end-of-range (EOR) defect band and the surface. This behavior, which indicates a quasi-steady-state distribution of excess interstitials, emitted from the EOR band and absorbed at the surface, is observed for annealing times as short as 1 s at 900 deg. C. Using an etching procedure we vary the distance x_E_O_R from the EOR band to the surface in the range 80-175 nm, and observe how this influences the interstitial supersaturation, s(x). The supersaturations at the EOR band and the surface remain unchanged, while the gradient ds/dx, and thus the flux to the surface, varies inversely with x_E_O_R. This confirms the validity of earlier modelling of EOR defect evolution in terms of ...

CERN Document Server

We investigate the extent to which the pure magnification effect of gravitational lensing can be extracted from galaxy clustering statistics, by a nulling method which aims to eliminate terms arising from the intrinsic clustering of galaxies. The aim is to leave statistics which are free from the uncertainties of galaxy bias. We find that nulling can be done effectively, leaving data which are relatively insensitive to uncertainties in galaxy bias and its evolution, leading to cosmological parameter estimation which is effectively unbiased. This advantage comes at the expense of increased statistical errors, which are in some cases large, but it offers a robust alternative analysis method to cosmic shear for cosmological imaging surveys designed for weak lensing studies, or to full modelling of the clustering signal including magnification effects.

International Nuclear Information System (INIS)

The Moderator Temperature Coefficient of reactivity (MTC) was earlier proven to be properly determined via noise analysis when the neutron noise is measured locally and when the radial average of the moderator temperature noise is used. Nevertheless, measurements revealed that the MTC was correctly estimated on a much narrower frequency band (0.6 - 0.7 Hz) than expected (0.1 - 1.0 Hz). The present paper investigates the effect of the feedback on the MTC determination using this new MTC noise estimator (which could explain the deviation at low frequencies, i.e. between 0.1 - 0.5 Hz) and the effect of the detector time constants (which could explain the deviation at high frequencies, i.e. between 0.7 - 1.0 Hz). For that purpose, a coupled neutronic/thermalhydraulic model of the Ringhals-3 PWR is developed in the frequency-domain, based on a radial 2-dimensional heterogeneous representation of the core. The transfer function of the detectors is ...

British Library Electronic Table of Contents (United Kingdom)

The individuality of production devices should be taken into account when statistical models are designed for parallelized devices. In the present work, a new clustering method, referred to as NC-spectral clustering, is proposed for discriminating the individuality of production devices. The key idea is to classify samples according to the differences of the correlation among measured variables, since the individuality of production devices is expressed by the correlation. In the proposed NC-spectral clustering, the nearest correlation (NC) method and spectral clustering are integrated. The NC method generates the weighted graph that expresses the correlation-based similarities between samples, and the constructed graph is partitioned by spectral clustering. A new statistical process monit...

British Library Electronic Table of Contents (United Kingdom)

Abstract The electrochemical properties of a perfluorosulfonic acid (PFSA) membrane are estimated using a combination of molecular dynamics simulation and statistical thermodynamic model. We obtain all parameters in an ionic conductivity model from an atomistic simulation and remove all adjusted model parameters. From a microscopic point of view, the hydrated PFSA membrane shows micro-phase segregation which separated into hydrophilic and hydrophobic phases. Our present work originates with this phenomenon and we treat this phase segregation as if it is a continuous phase for each of which the proton (H+) is transported inside the PFSA membrane/solvent (water and alcohols) mixture. The chemical potential for a given system is estimated using a molecular simulation technique to predict the ...

CERN Document Server

Model selection aims to determine which theoretical models are most plausible given some data, without necessarily asking about the preferred values of the model parameters. A common model selection question is to ask when new data require introduction of an additional parameter, describing a newly-discovered physical effect. We review several model selection statistics, and then focus on use of the Bayesian evidence, which implements the usual Bayesian analysis framework at the level of models rather than parameters. We describe our CosmoNest code, which is the first computationally-efficient implementation of Bayesian model selection in a cosmological context. We apply it to recent WMAP satellite data, examining the need for a perturbation spectral index differing from the scale-invariant (Harrison-Zel'dovich) case.

Energy Technology Data Exchange (ETDEWEB)

For the sugar industry, a new system of multiple-effect evaporation consuming minimal steam has been designed by means of a mathematical model and its advantages and characteristics are analysed. A way is found to overcome difficulty in operation and instability of the amount of steam consumed. Statistical data obtained using the new system are compared with the old system and show an economic profit as well as confirming the validity of the model. (author)

Science.gov (United States)

PMID:16589753

CERN Document Server

In this work we investigate the multivariate statistical description of the matter distribution in the nonlinear regime. We introduce the multivariate Edgeworth expansion of the lognormal distribution to model the cosmological matter field. Such a technique could be useful to generate and reconstruct three-dimensional nonlinear cosmological density fields with the information of higher order correlation functions. We explicitly calculate the expansion up to third order in perturbation theory making use of the multivariate Hermite polynomials up to sixth order. The probability distribution function for the matter field includes at this level the two-point, the three-point and the four-point correlation functions. We use the hierarchical model to formulate the higher order correlation functions based on combinations of the two-point correlation function. This permits us to find compact expressions for the skewness and ...

International Nuclear Information System (INIS)

The electron-phonon coupling constant lambda has been calculated for vanadium. The electron energy bands and wave functions were obtained from a model augmented plane wave muffin-tin potential. The electron-phonon matrix elements were evaluated using the rigid-ion approximation and the measured phonon spectra. The results show that lambda is strongly affected by d-f scattering.

CERN Document Server

Gas and stars in spiral galaxies are modelled with the DUAL code, using hydrodynamic and N-body techniques. The simulations reveal morphological differences mirroring the dual morphologies seen in B and K' band observations of many spiral galaxies. In particular, the gaseous images are more flocculent with lower pitch angles than the stellar images, and the stellar arm-interarm contrast correlates with the degree of morphological decoupling.

Science.gov (United States)

By using a model dielectric matrix in electron self-energy evaluations the computational effort of a quasiparticle band-structure calculation for a semiconductor is greatly reduced. Applications to various systems with or without inversion symmetry, having narrow or wide band gaps, and semiconductor alloys demonstrate the reliability and accuracy of the method. Calculations have been performed for thirteen semiconducting or insulating materials: Si, LiCl, AlP, AlAs, AlSb, GaP, GaAs, GaSb, InP, InAs, InSb, and the Al{sub 0.5}Ga{sub 0.5}As and In{sub 0.53}Ga{sub 0.47}As alloys. Excellent agreement with experimental results is obtained for the quasiparticle energies for these materials. The only three exceptions, {ital E}({Gamma}{sub 1{ital c}}) of AlP, {ital E}({ital L}{sub 1{ital c}}) of AlAs, and {ital E}({ital L}{sub 1{ital c}}) of AlSb are discussed and attributed to various experimental uncertainties. Several other ...

International Nuclear Information System (INIS)

Fermi radii and velocities are determined by deconvoluting de Haas-van Alphen data. Comparison of these data with accurate augmented-plane-wave band-structure results establishes the reliability of the augmented-plane-wave calculations and allows a determination of the anisotropic many-body enhancement factor lambda(k). The Fermi-surface average of 1.33 suggests a large electron-electron contribution. Our anisotropic lambda(k) porvides a detailed test and guide for model calculations of many-body enhancement.

CERN Document Server

A phase transition of gas-liquid type with an upper critical point is examined which arises in a model of charges of one sign on compensating background (OCP). The phase transition parameters are dependent on the detailed assumptions about the compressibility of the background, but the occurrence of this transition is independent on the background equation of state. In the electron-gas model ('jellium'), this transition appears to rule out Wigner crystallization. A variational principle in statistical mechanics is used to derive so-called Double-OCP model for a superposition of two one-component plasma models for charges of opposite sign. The free energy of this model sets an upper bound to that of a real plasma. Situations are discussed where this transition should manifest itself in anomalies in the approximate description of a non-ideal plasma.

International Nuclear Information System (INIS)

The band crossing in "1"3"2Ba has been investigated by using the interacting boson model. A broken neutron pair has been coupled to a collective boson core. The boson-fermion interaction hamiltonian contains terms which can transform a boson into a pair of quasiparticles and vice versa. The parameters were partly determined by fitting the collective states of "1"3"2","1"3"4Ba and the yrast states of "1"3"1Ba. The energy backbending has been satisfactorily reproduced. Good agreement of the electromagnetic moments has been reached. The structure of the wave functions has been discussed. (author)

CERN Document Server

Statistical Inference, Econometric Analysis and Matrix Algebra

British Library Electronic Table of Contents (United Kingdom)

A mechanical model with local resonators is proposed as an acoustic metamaterial that exhibits an unusual frequency-dependent effective stiffness. If treated as an equivalent elastic solid, its effective Young's modulus can become unbounded or vanishingly small at two respective frequencies. Moreover, in a certain frequency range, the effective Young's modulus would become negative, resulting in a band gap that coincides with this frequency range. The wave attenuation behavior and mechanism are studied through numerical simulations on the acoustic metamaterial model. The capability of the metamaterial to selectively block or filter unwanted waves is demonstrated by a numerical simulation example.

Energy Technology Data Exchange (ETDEWEB)

The existence of a narrow peak in the electronic density of states in A-15 compounds is explained by a strong electron--phonon interaction that leads to the polaron narrowing of the band. An analytic expression relating the transition temperature T/sub c/ to the phonon spectrum is derived under the assumption of a weak and an intermediate-strength coupling. The model allows the explanation of the correlation of T/sub c/ with the number of electrons per atom, the temperature dependence of the resistance, the magnitude and temperature dependence of the magnetic susceptibility, and the electronic specific heat.

Energy Technology Data Exchange (ETDEWEB)

A local Heine-Abarenkov model potential is proposed for zinc blende-type crystals. The potential parameters are determined by satisfying the zero pressure condition and the first zero of the empirical pseudopotential interpolated from band calculations. Two sets of parameters are presented for thirteen tetrahedral compounds such as AlP, AlAs, AlSb, GaP, GaAs, GaSb, InP, InAs, InSb, ZnS, ZnSe, ZnTe, and CdTe.

International Nuclear Information System (INIS)

We studied the influence of alloying on the structural and electronic properties of the unrelaxed and relaxed Si_1_-_yC_y random alloys by means of ab initio theoretical calculations using two methods: (i) a supercell approach in connection with the plane-wave pseudopotential method; (ii) the full-potential augmented plane-wave plus local orbitals (APW+lo) method. The first method is used to obtain the relaxed atomic structure. The relaxed atomic positions obtained by pseudopotential calculations were used to calculate the band structure via the second method. The local density approximation was used for the exchange and correlation energy density functional. We investigated the lattice parameters and band gap energies. We found that a quite smaller gap appears in the neighborhood of y=0.03125 concentration of C atoms. The band gap shows a large anomalous bowing and is strongly composition dependent. The electron densities ...

International Nuclear Information System (INIS)

The decay of molybdenum-101 has been investigated using the three-parameter (#gamma#-#gamma#-t) coincidence system of HPGe-HPGe detectors. According to the off-line analysis, the decay scheme was modified. The positions of 221.80, 318.00, 377.90; 452.50, 515.42, 1011.05, and 1759.72 keV transitions have been arranged again, the transition positions of 104.70, 105.95, and 774.15 keV gamma rays have been assigned for the first time, the positions of 169.00, 590.91, 980.52, and 1431.68 keV transitions have been reconfirmed, and the 1508.01 keV gamma ray was observed simultaneously for the first time and its transition position has been assigned. The #beta#"- intensities and the values of log ft of most levels were calculated. Combining with the high-spin states observed by the in-beam #gamma#-ray spectroscopy of previous decay works, the structure of the excited positive/negative-parity yrast states of "1"0"1Tc is discussed using a projected shell model, and a ...

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In this study, drought analysis of annual flows of Jindong, Hyunpoong, and Waekwan stations located at Nakdong River Basins was performed based on multivariate stochastic models. The stochastic models used were multivariate autoregressive model(MAR) and multivariate contemporaneous (MCAR) model. MCAR(1) and MAR(1) models were selected to be appropriate models for these stations based on skewness test of normality, test of uncorrelated residuals, and correlograms of the residual series of each model. The statistics generated by MCAR(1) model and MAR(1) model resembled very closely those computed from historical series. The drought characteristics such as run length, run sum, and run intensity were fairly well reproduced for the various lengths of generated annual flows based on ...

Energy Technology Data Exchange (ETDEWEB)

This article deals with excavation equipment used in open-pit mining operations. Because of competition in the mining industry, a demand for more energy-efficient excavators is being felt. The authors present different types of machinery and give statistics on energy use, weights, bucket capacity, and maximum digging depths. Actual manufacturers specifications are also given for different models. A short discussion on the role computers are playing in this new technology is also given.

CERN Document Server

We study the temporal evolution of the market efficiency in the stock markets using the complexity, entropy density, standard deviation, autocorrelation function, and probability distribution of the log return for Standard and Poor's 500 (S&P 500), Nikkei stock average index, and Korean composition stock price index (KOSPI). Based on the microscopic spin model, we also find that these statistical quantities in stock markets depend on the market efficiency.

Science.gov (United States)

We introduce a discrete multiplicative process as a generic model of competition. Players with different abilities successively join the game and compete for finite resources. Emergence of dominant players and evolutionary development occur as a phase transition. The competitive dynamics underlying this transition is understood from a formal analogy to statistical mechanics. The theory is applicable to bacterial competition, predicting novel population dynamics near criticality.

International Nuclear Information System (INIS)

A tissue-equivalent dosimetry system has been developed for use in absorbed dose determinations with physical models of Reference Man. The dosimeter used was a thermo-luminescent dosimeter (TLD) powder which was mixed with a 'tissue-equivalent' material and modeled to closely approximate an organ's geometry and absorption properties. A separation procedure was developed by which the TLD powder was washed and the 'tissue-equivalent' material, a wax, was dissolved and extracted following the irradiation of the model. The procedure was tested to determine losses of powder, homogeneity of the powder's distribution throughout the wax, the effects of the separation procedure upon the powder and the statistical behavior of the procedure. The results of these tests established the feasibility of the procedure. A full-scale model of the pancreas was tested and the results supported the ...

CERN Document Server

The Fourier transform of cosmological density perturbations can be represented in terms of amplitudes and phases for each Fourier mode. We investigate the phase evolution of these modes using a mixture of analytical and numerical techniques. Using a toy model of one-dimensional perturbations evolving under the Zel'dovich approximation as an initial motivation, we develop a statistic that quantifies the information content of the distribution of phases. Using numerical simulations beginning with more realistic Gaussian random-phase initial conditions, we show that the information content of the phases grows from zero in the initial conditions, first slowly and then rapidly when structures become non-linear. This growth of phase information can be expressed in terms of an effective entropy: Gaussian initial conditions are a maximum entropy realisation of the initial power spectrum, gravitational evolution decreases the phase entropy. We show that ...

CERN Document Server

We discuss some methods to quantitatively investigate the properties of correlation matrices. Correlation matrices play an important role in portfolio optimization and in several other quantitative descriptions of asset price dynamics in financial markets. Specifically, we discuss how to define and obtain hierarchical trees, correlation based trees and networks from a correlation matrix. The hierarchical clustering and other procedures performed on the correlation matrix to detect statistically reliable aspects of the correlation matrix are seen as filtering procedures of the correlation matrix. We also discuss a method to associate a hierarchically nested factor model to a hierarchical tree obtained from a correlation matrix. The information retained in filtering procedures and its stability with respect to statistical fluctuations is quantified by using the Kullback-Leibler distance.

Energy Technology Data Exchange (ETDEWEB)

This paper describes a simulation model for predicting end-use energy consumption in residential sectors of a city or region. In this model, the annual energy consumption of a dwelling is simulated from the occupants' schedule of living activities, weather data and energy efficiencies of appliances and dwellings. By summing up the simulation results for various household categories, total energy consumption for the residential sector in a region can be estimated. In this paper, energy consumption for Osaka City is simulated. The result is compared with statistical data. The effects of energy efficiency standards and urban heat island phenomena are examined. (author)

Energy Technology Data Exchange (ETDEWEB)

In recent years the 'Nowcasting Wake Vortex Impact Variables' model NOWVIV has been developed at the Deutsches Zentrum fuer Luft- und Raumfahrt, DLR, to forecast weather parameters in airport environments. The German Meteorological Service, DWD, employs his COSMO-DE model (COnsortium for Small scale Modelling-DEutschland) for operational forecasts in Germany. A systematic comparison of model output from NOWVIV and a derivate of COSMO-DE, named COSMO-FRA, is presented. Both models are centred at Frankfurt Airport with horizontal resolutions of 2.1 km and 2.8 km, respectively. In the DLR Project Wetter and Fliegen the COSMO-FRA model will replace the NOWVIV model and become a key component in the future rapid update cycle for adverse weather predictions at the airports of Frankfurt and Munich. The forecast vertical profiles ...

CERN Document Server

We develop and demonstrate the methodology of testing multi-dimensional supernova models against observations by studying the properties of one example of the detonation from failed deflagration (DFD) explosion model of thermonuclear supernovae. Using time-dependent multi-dimensional radiative transfer calculations, we generate the synthetic broadband optical light curves, near-infrared light curves, color evolution curves, full spectral time-series, and spectropolarization of the model, as seen from various viewing angles. All model observables are critically evaluated against examples of well-observed, standard Type Ia supernovae (SNe Ia). We explore the consequences of the intrinsic model asphericity by studying the dependence of the model emission on viewing angle, and by quantifying the resulting dispersion in (and internal correlations between) various ...

Science.gov (United States)

The current status of a computational aeroacoustics (CAA) approach to simulate broadband noise is reviewed. The method rests on the use of steady Reynolds averaged Navier-Stokes (RANS) simulation to describe the time-averaged motion of turbulent flow. By means of synthetic turbulence the steady one-point statistics (e.g. turbulence kinetic energy) and turbulent length- and time-scales of RANS are translated into fluctuations having statistics that very accurately reproduce the initial RANS target-setting. The synthetic fluctuations are used to prescribe sound sources which drive linear perturbation equations. The whole approach represents a methodology to solve statistical noise theory with state-of-the-art CAA tools in the time-domain. A brief overview of the synthetic turbulence model and its numerical discretization in terms of the random particle-mesh (RPM) and fast random particle-mesh (FRPM) ...

CERN Document Server

One of the salient features of human perception is its invariance under dilatation in addition to the Euclidean group, but its non-invariance under special conformal transformation. We investigate a holographic approach to the information processing in image discrimination with this feature. We claim that a strongly coupled analogue of the statistical model proposed by Bialek and Zee can be holographically realized in scale invariant but non-conformal Euclidean geometries. We identify the Bayesian probability distribution of our generalized Bialek-Zee model with the GKPW partition function of the dual gravitational system. We provide a concrete example of the geometric configuration based on a vector condensation model coupled with the Euclidean Einstein-Hilbert action. From the proposed geometry, we study sample correlation functions to compute the Bayesian probability distribution.

Energy Technology Data Exchange (ETDEWEB)

The aim of this study is to develop the methodology which enables to identify the mechanical properties of element such as stress intensity factor by using the AE parameters. Considering the multivariate and nonlinear properties of AE parameters such as ringdown count, rise time, energy, event duration and peak amplitude from fatigue cracks of machine element the principal component regression(PCR) and artificial neural network(ANN) models for the estimation of stress intensity factor were developed and validated. The AE parameters were found to be very significant to estimate the stress intensity factor. Since the statistical values including correlation coefficients, standard mr of calibration, standard error of prediction and bias were stable, the PCR and ANN models for stress intensity factor were very robust. The performance of ANN model for unknown data of stress intensity factor was better than ...

British Library Electronic Table of Contents (United Kingdom)

To improve the performance of voice activity detector (VAD) in noisy environments, this paper concentrates on three critical aspects related to noise robustness including speech features, feature distributions and temporal dependence. Based on the statistic on TIMIT and NOIZEUS, Mel-frequency cepstrum coefficients (MFCCs) are selected as speech features, Gaussian Mixture distributions (GMD) are applied to associate the observations in MFCC domain with both speech and non-speech states, and Weibull and Gamma distributions are used to explicitly model noise and speech durations, respectively. To integrate these aspects into VAD, the hidden semi-Markov model (HSMM) as a generalized hidden Markov model (HMM) is introduced first. Then the VAD decision is made according to the likelihood ratio t...

Energy Technology Data Exchange (ETDEWEB)

It has recently been found that many buildings in Taiwan were constructed with radioactively contaminated rebar, which raised great concern among the residents as well as governmental officials. In order to investigate the possible cytogenetic damage to the residents of contaminated buildings, a G-banding method was carried out on the lymphocytes of 30 radiation-exposed individuals from four families and one office building, as well as 15 control individuals from laboratory personnel. The estimated cumulative radiation doses for the exposed people range from 19.63 to 280.50 mSv. Altogether, 13 females and 17 males belonging to the radiation-exposed group, and 7 females and 8 males in the control group, were included in this study. With the exception of one sample, at least 500 metaphase spreads were scored and analyzed for each individual. All the recognizable structural aberrations of chromosomes or chromatids were recorded and statistically ...

Energy Technology Data Exchange (ETDEWEB)

We have carried out theoretical calculations for the production of the long-lived isomers {sup 93m}Nb({1/2}{sup {minus}}, 16y), {sup 121m}Sn(11/2{minus}, 55 yr), {sup 166m}Ho(7-, 1200 yr), {sup 184m}Re(8+, 165 d), {sup 186m}Re(8+, 2{times}10{sup 5} yr), {sup 178m}Hf(16+, 31 yr), {sup 179m}Hf(25/2-, 25 d), {sup 192m}Ir(9+, 241 yr), all of which pose potential radiation activation problems in nuclear fusion reactors. We consider (n, 2n), (n,n{prime}), and (n, {gamma}) production modes and compare our results both with experimental data (where available) and systematic. We also investigate the dependence of the isomeric cross section ratio on incident neutron energy for the isomers under consideration. The statistical Hauser-Feshbach plus preequilibrium code GNASH was used for the calculations. Where discrete state experimental information was lacking, rotational band members above the isomeric state, which can be justified theoretically but have ...

Energy Technology Data Exchange (ETDEWEB)

Calculating work-function modifications for flat-lying conjugated molecules on extended metal surfaces using density functional theory (DFT) is an extremely resource intensive task. This prevents fast screening of new molecules for their potential to optimize metal work functions for good electron or hole injection in organic electronic devices. We present a semi-classical model, which avoids that problem. This is achieved by identifying the dominant processes occurring at the interface between metal and adsorbate in the pinning-regime, which are then parameterizing their description using band-structure DFT calculations for a small training set With the resulting interdependent equations at hand, only simple gas-phase calculations are needed to predict the work-function changes induced by new molecules. The model is tested for ten molecules on three different metal surfaces, where it shows excellent agreement with ...

DEFF Research Database (Denmark)

The sources of non-white noise in Blood Oxygenation Level Dependent (BOLD) functional magnetic resonance imaging (fMRI) are many. Familiar sources include low-frequency drift due to hardware imperfections, oscillatory noise due to respiration and cardiac pulsation and residual movement artefacts not accounted for by rigid body registration. These contributions give rise to temporal autocorrelation in the residuals of the fMRI signal and invalidate the statistical analysis as the errors are no longer independent. The low-frequency drift is often removed by high-pass filtering, and other effects are typically modelled as an autoregressive (AR) process. In this paper, we propose an alternative approach: Nuisance Variable Regression (NVR). By inclusion of confounding effects in a general linear model (GLM), we first confirm that the spatial distribution of the various fMRI noise sources is similar to what has already been ...

International Nuclear Information System (INIS)

The credibility of the model proposed by Ghosh in predicting the refractive indices of mixed semiconductor crystals of technological importance within their miscibility range as a function of band gap is demonstrated. The high-frequency refractive indices of four quaternary alloys Al_xGa_1_-_x_-_yIn_yP (y = 0.49, 0 #<=# x #<=# 0.51), InSb_xAs_1_-_x_-_yP_y (y = 2.2x, 0 #<=# x #<=# 0.313, 0 #<=# y #<=# 0.638), Cd_xZn_1_-_x_-_yHg_ySe (x + y = 1, 0.153 #<=# x #<=# 0.684, 0.316 #<=# y #<=# 0.847), and CdS_1_-_x_-_ySe_xTe_y (x + y = 1, 0.15 #<=# x #<=# 0.93, 0.07 #<=# y #<=# 0.85) are calculated according to the relation n"2-1 = A/(E_g + B)"2 where A is an energy gap dependent constant and B is a constant depending on crystal ionicity. The calculated values show excellent agreement with the experimental data thus justifying the validity of the model.

International Nuclear Information System (INIS)

We have synthesized ozone by irradiating thin solid films of oxygen and oxygen-water mixtures with 100 keV protons, motivated by recent reports of condensed O_3 on icy satellites in the outer Solar system. We measured the depth of the Hartley absorption band in the ultraviolet by reflectance spectroscopy and used it to quantify the column density of ozone. We analyzed the results using a three-component (O, O_2 and O_3) model that successfully explains the fluence dependence of ozone production.

Energy Technology Data Exchange (ETDEWEB)

The level structure of the doubly-odd /sup 242/Am nucleus was investigated by means of thermal-neutron-capture gamma-ray and conversion electron spectroscopy. Pair, curved-crystal, and ..beta.. spectrometers were used. The data from these measurements, combined with previous direct reaction results, permit us to establish a detailed level scheme including six new well-developed bands. Our experimental results are interpreted in the framework of the Nilsson model. Precise Gallagher-Moszkowski splittings and Newby odd-even shifts extracted from the data are compared with theoretical calculations.

Energy Technology Data Exchange (ETDEWEB)

High interelectrode voltage peaks have been observed simultaneously with the emission of hard X-ray bursts from a flash X-ray tube. The magnitude of the voltage peaks may exceed twice the initial charging voltage. It has also been observed that the discharge emits bursts of X-and P-band microwaves radiation which are coincident with the emission of the hard X-ray bursts. The results indicate that the microwaves and X-rays have a common origin in discharge plasma movements and an acceleration model for electrons in the plasma is presented as one possible explanation of the observed phenomena.

Science.gov (United States)

Not Available

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

The [402]5/2 bands in "1"7"7Ta which are ''identical'' to the neighboring even-even "1"7"6Hf groundstate band have been extended to higher angular momentum. These bands in the two nuclei are seen to diverge from each other in the region of the first i_1_3_/_2 neutron alignment. The lower observed crossing frequency for the [402]5/2 bands indicates a lower deformation for these bands compared to "1"7"6Hf. Extensions to the h_9_/_2 [541]1/2 yrast band are also reported. (orig.).

Science.gov (United States)

... The pharmacologist/toxicologist and the statistician will jointly determine if a statistical review is needed and when the review should be done. ...

International Nuclear Information System (INIS)

One of the most profound features of electricity spot prices are the price spikes. Markov regime-switching (MRS) models seem to be a natural candidate for modeling this spiky behavior. However, in the studies published so far, the goodness-of-fit of the proposed models has not been a major focus. While most of the models were elegant, their fit to empirical data has either been not examined thoroughly or the signs of a bad fit ignored. With this paper we want to fill the gap. We calibrate and test a range of MRS models in an attempt to find parsimonious specifications that not only address the main characteristics of electricity prices but are statistically sound as well. We find that the best structure is that of an independent spike 3-regime model with time-varying transition probabilities, heteroscedastic diffusion-type base regime ...

CERN Document Server

The analysis of the linearization effect in multifractal analysis, and hence of the estimation of moments for multifractal processes, is revisited borrowing concepts from the statistical physics of disordered systems, notably from the analysis of the so-called Random Energy Model. Considering a standard multifractal process (compound Poisson motion), chosen as a simple representative example, we show: i) the existence of a critical order q* beyond which moments, though finite, cannot be estimated through empirical averages, irrespective of the sample size of the observation; ii) that multifractal exponents necessarily behave linearly in q, for q > q*. Tailoring the analysis conducted for the Random Energy Model to that of Compound Poisson motion, we provide explicative and quantitative predictions for the values of q* and for the slope controlling the linear behavior of the multifractal exponents. These quantities are ...

Energy Technology Data Exchange (ETDEWEB)

The Model of Acidification of Groundwaters in Catchments (MAGIC) was used to simulate the impact of acidifying deposition and future recovery at the Gaardsjoen Covered Catchment Experiment, at a number of hypothetical stations defined by statistical variation of the Gaardsjoen data and at 20 forest monitoring sites in Southern Sweden. For the future predictions a decrease of sulphur deposition of more than 70% was assumed. This assumption is based on a full implementation of the agreements made under the second sulphur protocol from 1994. The modelled impact of reduced deposition on the soils and on the runoff waters was discussed. To complement the discussion on long-term trends in future run-off chemistry, data from Gaardsjoen has been used to asses the risk for short-term acid runoff episodes 26 refs, 23 figs, 7 tabs

DEFF Research Database (Denmark)

A seasonal forecasting technique to produce probabilistic and deterministic streamflow forecasts for 23 basins in Norway and northern Sweden is developed in this work. Large scale circulation and moisture fields, forecasted by the ECHAM4.5 model 4 months in advance, are used to forecast spring flows. The technique includes model output statistics (MOS) based on a non-linear Neural Network (NN) approach. Results show that streamflow forecasts from Global Circulation Model (GCM) predictions, for the Scandinavia region are viable and highest skill values were found for basins located in south-western Norway. The physical interpretation of the forecasting skill is that stations close to the Norwegian coast are directly exposed to prevailing winds from the Atlantic ocean, which constitute the principal source of predictive information from the atmosphere on the seasonal timescale.

Energy Technology Data Exchange (ETDEWEB)

The Atmospheric Release Advisory Capability (ARAC) at the Lawrence Livermore National Laboratory uses the U.S. Navy's Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS) to supply high-resolution wind data for use in its real-time dispersion modeling system. ARAC has used COAMPS products to support several events and exercises, and COAMPS forecasts appear accurate, based on qualitative examination. Recently ARAC has developed a quantitative verification system which calculates COAMPS error and bias statistics, comparing COAMPS forecasts of various lengths with observational data. This paper shows how this system has been used to guide ARAC operators, who need an estimate of the likely behavior of COAMPS forecasts of various lengths in different regions, seasons, and weather patterns.

Energy Technology Data Exchange (ETDEWEB)

Experiments were performed to measure the transfer of trichloroethylene (TCE), a volatile organic compound (VOC), from tap water in showers to indoor air. In these experiments, the loss of TCE from tap water in the shower is based on the difference between influent and effluent concentrations.We have developed and previously published a three-compartment model, which we use to simulate the 24-h concentration history of VOCs in the shower, bathroom, and remaining household volumes resulting from the use of contaminated tap water. An important input to this model is the transfer efficiency of the VOC from water to air. The experiments reveal that the transfer efficiency of TCE from shower water to air has an arithmetic mean value of 51 percent and an arithmetic standard deviation of 9 percent. Analysis of the results shows that there is no statistically significant difference between the transfer efficiency measured with hot ...

International Nuclear Information System (INIS)

The paramagnetic susceptibilities of all the RCo_2 compounds for which measurements are available are found to obey a Curie-Weiss law consistent with the modified indirect exchange model. The rare-earth ions are in a well defined tripositive valence state. Paramagnetic moments and paramagnetic Curie temperatures are obtained for these materials for the first time. The paramagnetic moments of these materials are changed from their free-ion values by the effects of itinerant electron polarisation, an effect which is particularly large for SmCo_2 whose paramagnetic moment is almost three times greater than the free-ion value. The modified indirect exchange model is found to be able to give a full description of the magnitude of the rare-earth, cobalt and diffuse moments in polarised neutron experiments. The band structures of the light RCo_2 compounds are found to be distinctly different to those of the heavy RCo_2 compounds. ...

CERN Document Server

We report novel, high-angular resolution interferometric measurements that imply the near-infrared nuclear emission in NGC 4151 is unexpectedly compact. We have observed the nucleus of NGC 4151 at 2.2 microns using the two 10-meter Keck telescopes as an interferometer and find a marginally resolved source ~0.1 pc in diameter. Our measurements rule out models in which a majority of the K band nuclear emission is produced on scales larger than this size. The interpretation of our measurement most consistent with other observations is that the emission mainly originates directly in the central accretion disk. This implies that AGN unification models invoking hot, optically thick dust may not be applicable to NGC 4151.

International Nuclear Information System (INIS)

The dependence of the carrier concentrations, of the resistivity and of the Hall coefficient of irradiated silicon on the neutron fluences has been investigated, starting from the supposition that the main phenomena induced by irradiation in the semiconductor bulk are shallow-donor removal and deep-centres creation. The free parameters of the model are initial doping of the starting material, the permitted energy level values of the radiation-induced centres in the semiconductor band gap and their introduction rates. The influence of each parameter on the calculated dependences is studied in detail, for three cases: one deep acceptor-like centre, two deep acceptors and one deep acceptor plus one deep donor-like centre. each of the three cases is discussed in correspondence with different experimental results.

Science.gov (United States)

Divergence between aircraft engine emission regulations proposed by EPA and ICAO is discussed. Every engine, upon entering service, requires a certificate as to its compliance with emission standards. It is shown that despite the large variability in the measurements, it is possible to devise a certification procedure requiring the testing of one engine only. Statistical modeling of such a test at the 5% significance level is described. Values of the parameter standard deviation/mean recommended as certification standards for various pollutants are given. Features of a rational certification scheme to be formulated are outlined.

Energy Technology Data Exchange (ETDEWEB)

The solvation properties of a chlorine ion in small water clusters are investigated using state-of-the-art statistical mechanics. The simulations employ the polarizable water model developed recently by Dang [J. Chem. Phys. [bold 97], 2659 (1992)]. The ion--water interaction potentials are defined such that the successive binding energies for the ionic clusters, and the solvation enthalpy, bulk vertical binding energy, and structural properties of the aqueous solution agree with the best available results obtained from experiments. Simulated vertical electron binding energies of the ionic clusters Cl[sup [minus

International Nuclear Information System (INIS)

A wood/polymer composite was produced by impregnating Ramin wood with methyl methacrylate monomer and subsequently polymerizing it by gamma irradiation. To assess the improvement in compression strength of the wood caused by the polymer impregnation, a microbuckling compression failure mechanism was used to model the compression failure of the composite. Such a mechanism was found to predict a linear relationship between the compression strength and the percentage polymer impregnation (by weight). Uniaxial compression test results at 45(#+-#5)% and 90(#+-#5)% relative humidity levels, after being statistically analysed, showed that such a linear relationship was valid for up to 100% polymer impregnation. (author).

International Nuclear Information System (INIS)

The nuclear structure of A #propor to# 100 nuclei has been studied in the frame of this thesis with a recently developed #beta# - #gamma# - #gamma# triple coincidence fast timing technique and different models such as shell model, hydrodynamic model, Nilsson and particle-rotor models. This technique which allows the measurement of the level lifetimes in the ps range has been applied at JOSEF at the research reactor DIDO of KFA Juelich in studes of the short-lived neutron-rich nuclei in the A #approx =# 100 region. Lifetimes of level in "9"6,"9"8,"1"0"0 ZR, "9"9,"1"0"1-"1"0"4 Nb, "1"0"0-"1"0"5 Mo have been measured, which are in many cases completely new, and otherwise more precise than previously published data. From the lifetimes of the members of rotational bands, the size of the nuclear deformations has been deduced. (orig./HSI).

Energy Technology Data Exchange (ETDEWEB)

Pipeline leak detection technologies can be classified according to their specificity, such as their application to offshore or onshore installations or to multi-phase or single-phase flow regimes. They can also be classified according to the technology on which they are based. Available technologies can be categorized into the following 4 groups: (1) compensated mass balance, solving steady state equations which model a specific pipeline, known as real time mode (RTM), (2) the same as group 1, but solving transient equations, known as real time transient model (RTTM), (3) pressure wave behavior, and (4) statistical modeling. Hybrids schemes can also be found. Effective leak detection systems are needed to address the increasing transformation of very large crude cargo (VLCC) ships into floating production, storage and offloading (FPSO) systems. These operations make use of short and large diameters ...

Energy Technology Data Exchange (ETDEWEB)

The Thai natural rubber economy is described in the context of the world rubber market. An econometric model is estimated for 15 structural equations; it includes the Thai, US, and rest-of-the-world rubber economies. Several simulation experiments are analyzed for the period from 1984 to 1995. Impact and dynamic multipliers are reported for major endogenous variables in response to changes in US GDP, world crude oil price, Thai replanting cess tax and Thai natural rubber production. A 1%, one-time increase in the US GDP has a positive effect on the Singapore natural rubber price. A world crude oil price decline shock has a negative effect in both the short-run and the long-run. The INRO buffer stock stabilization policy as well as alternative domestic Thai policies of market intervention are analyzed. The simulation results show that buffer stock management which allows a price band of +/-20% around the price target has the most stabilized ...

International Nuclear Information System (INIS)

The band structure (BS) of crystalline Bi_2Se_2Te both pure as well as deposited on Si or SiO_2 (substrates) was calculated for the first time. The calculation approach consists of an orthogonalization of the plane wave basis set with respect to the core-like orbitals and the application of the Perdew-Alder exchange-correlation scheme. In addition, a virtual crystal approach was applied. Experimental ellipsometric spectra were used as a criterion of the advantages of the different calculation techniques. The results of traditional one-electron methods of BS calculations, using norm-conserving pseudo-potential (NCPP), and full linear augmented plane wave (FLAPW), were compared with the experimental data. Better agreement with experiment is achieved when the NCPP wave functions are orthogonalized to the 4dBi core-like states. Concerning the LMTO and the FLAPW all-electron methods, only appropriate application of the virtual crystal approximation to these approaches ...

Energy Technology Data Exchange (ETDEWEB)

A quantitative transmission electron microscopy (TEM) study on the depth profile of extended defects, formed after Si implantation, has been carried out. Two different Si{sup +} implant conditions have been considered. TEM analysis for the highest energy/dose shows that {l_brace}1 1 3{r_brace} defects evolve into dislocation loops whilst the defect depth distribution remains unchanged as a function of annealing time. For the lowest energy/dose, {l_brace}1 1 3{r_brace} defects grow and dissolve while the defect band shrinks preferentially on the surface side. At the same time, extraction of boron transient enhanced diffusion (TED) as a function of depth shows a decrease of the supersaturation towards the surface, starting at the location of the defect band. The study clearly shows that in these systems the silicon surface is the principal sink for interstitials. The results provide a critical test of the ability of physical ...

Energy Technology Data Exchange (ETDEWEB)

A non-invasive, wide-band electromagnetic (EM) impedance difference system for shallow subsurface electrical structure characterization in environmental and engineering problems has been developed at the Lawrence Berkeley National Laboratory (LBNL). Electrical parameters of interest are electrical conductivity and dielectric permittivity that are deduced from the impedance difference data. The prototype system includes a magnetic loop transmitter, which operates between 0.1 MHz and 100 MHz, an electrical dipole antenna for observing the electric field, and a loop antenna for measuring the magnetic field.All antennas are mounted on a cart made of non-metallic material for easy movement of the whole array for profiling. Surface EM impedance difference is obtained by taking the difference of the ratios of the electric fields to the magnetic fields at selected frequencies at two different levels. Numerical simulations will be presented to verify this new approach. A ...

International Nuclear Information System (INIS)

Tris(8-quinolinolato)aluminum(III) (Alq3) shows electronic absorption bands at 378, 360 (in a 1:1 mixed solvent of methanol and ethanol (ME) at 77 K), 334, 316, 300, 263, 255.8, and 233 nm in ethanol at room temperature. According to the polarized fluorescence excitation spectrum together with MO calculations, for instance, the 360 nm band is assigned to an LL CT transition (an intramolecular charge transfer transition between two ligands), and the 378 nm band to an LM/ML CT one (an intramolecular charge transfer transition between ligand and metal). Alq3 shows a broad fluorescence band peaking at around 478 nm in the ME matrix at 77 K. The emission spectrum measured with a phosphoroscope has two emission bands at 567 and 478 nm. The 567 nm band accompanies vibronic bands at 578 and 605 nm, being safely assigned to a phosphorescence of Alq3. ...

Energy Technology Data Exchange (ETDEWEB)

A study has been made of the reaction [sup 86]Kr + [sup 63]Cu at incident energies of 486, 550, 640, and 730 MeV. Measurements include cross sections, angular distributions, and energy spectra for light charged particles ([sup 1,2,3]H and [sup 4]He), intermediate mass fragments (IMF) (4 [le] Z [le] 17), and heavy fragments (Z [ge] 18). Coincidences between light charged particles and between particles and fragments have been measured to obtain cross sections, energy spectra, and angular distributions. Statistical model analysis of the energy spectra for [sup 1]H and [sup 4]He detected in coincidence with the fragments has allowed estimation of [sup 1]H and [sup 4]He multiplicities associated with the evaporation residues, fragments, and composite nuclei prior to scission. A comparison of cross sections, energy spectra, angular distributions, and particle multiplicities for these matched entrance channels has provided the means for a detailed ...

Science.gov (United States)

Space Network Ku-band service. ... Completed GLAST mission schedule and budget assessment .... Utilize Ku band SN link (TDRSS) for science data return ...

CERN Document Server

The adjoint of an ocean general circulation model is used as a tool for investigating the causes of changes in ENSO SST indices. We identify adjoint Kelvin and Rossby waves in the sensitivities to sea level and wind stress at earlier times, which can be traced back for more than a year through western and weak eastern boundary reflections. Depending on the thermocline depth the first and second baroclinic modes are excited. The sensitivities to the heat flux and SST are local and decay in about a month. The sensitivities to the fluxes are converted into the influence of SST using the adjoint of a statistical atmosphere model. Focusing on SST perturbations in the index region itself, we recover, up to a scale factor, the delayed oscillator concept.

CERN Document Server

We provide a quantitative assessment of the probability distribution function of the concentration parameter of galaxy clusters. We do so by using the probability distribution function of halo formation times, calculated by means of the excursion set formalism, and a formation redshift-concentration scaling derived from results of N-body simulations. Our results suggest that the observed high concentrations of several clusters are quite unlikely in the standard Lambda CDM cosmological model, but that due to various inherent uncertainties, the statistical range of the predicted distribution may be significantly wider than commonly acknowledged. In addition, the probability distribution function of the Einstein radius of A1689 is evaluated, confirming that the observed value of ~45" +/- 5" is very improbable in the currently favoured cosmological model. If, however, a variance of ~20% in the theoretically predicted value of ...

Energy Technology Data Exchange (ETDEWEB)

Investment in mining projects is always associated with risk because of the inclusion of many uncertain parameters. Probability analysis can be applied to such a system which has many kinds of uncertain parameters. This kind of study uses historical data to provide more information for future decisions. This study uses the historical data from a truck-shovel operation at an open cut Coal Mine in NSW, Australia to develop a productivity estimation model, using stochastic analysis. In the first step statistics and various probability distributions were developed for both certain and uncertain variables. A correlation analysis was the next step to investigate any possible relationship between productivity and affecting parameters. The results of these two stages were then used in a simulation model using the stochastic approach. 2 figs.

International Nuclear Information System (INIS)

We present the effects of heavy CP-even (H) and CP-odd (A) Higgs bosons on the production cross section of the process #gamma##gamma##->#tt at the energy around the mass poles of the Higgs bosons. It is found that interference between H and A with small mass gap, as well as the ones between Higgs bosons and continuum, contributes to the cross section, if the photon beams are polarized and if we observe the helicity of the top quarks. It is demonstrated in the framework of the minimal supersymmetric extension of the standard model that the H and A contributions can be sizable at future #gamma##gamma# colliders for small values of tan #beta#. The methods to measure the CP-parity of the Higgs boson are also presented. The statistical significance of detecting the Higgs signals and measuring the Higgs CP-parity is evaluated. (orig.)

British Library Electronic Table of Contents (United Kingdom)

Fourier-transform infrared (FTIR) spectroscopy was used to monitor amino acids, organic acids, and changes during ripening. Twelve Cheddar cheese samples were ripened for 73 days and samples were drawn periodically. Water-soluble fractions of samples were analyzed by gas chromatography (20 amino acids), liquid chromatography (three organic acids), and FTIR spectroscopy (4000-700 cm-1). Spectra were correlated with chromatographic data and ripening events and analyzed by multivariate statistics to develop prediction and classification models. Most models showed a good fit (correlation coefficient > or =0.89) and could predict the levels of amino acids and organic acids and age of the cheese in less than 20 min. Lactic acid, leucine, glutamic acid, asparagine, phenylalanine, and valine were ...

British Library Electronic Table of Contents (United Kingdom)

Summary 1. A primary goal of evolutionary ecology is to understand factors selecting for the diversity of life histories. Life-history components, such as time-to-reproduction, adult survivorship and fecundity, might differ among species because of variation in direct and indirect benefits of these life histories in different environments or might have lower-than-expected variability because of phylogenetic constraints. Here, we present a phylogenetic examination of demography and life histories using a data base of 204 terrestrial plant species. 2. Overall, statistical models without phylogeny were preferred to models with phylogeny for vital rates and elasticities, suggesting that they lacked phylogenetic signal and are evolutionarily labile. However, the effect of phylogeny was signific...

CERN Document Server

Observations of redshift-space distortions in spectroscopic galaxy surveys offer an attractive method for measuring the build-up of cosmological structure, which depends both on the expansion rate of the Universe and our theory of gravity. Galaxies occupy dark matter halos, whose redshift space clustering has a complex dependence on bias that cannot be inferred from the behavior of matter. We identify two distinct corrections on quasilinear scales (~ 30-80 Mpc/h): the non-linear mapping between real and redshift space positions, and the non-linear suppression of power in the velocity divergence field. We model the first non-perturbatively using the scale-dependent Gaussian streaming model, which we show is accurate at the 10 (s>25) Mpc/h for the monopole (quadrupole) halo correlation functions. We use perturbation theory to predict the real space pairwise halo velocity statistics. Our fully analytic ...

Energy Technology Data Exchange (ETDEWEB)

Model-based approaches to pattern recognition and machine vision have been proposed to overcome the exorbitant training requirements of earlier computational paradigms. However, uncertainties in data were found to lead to a combinatorial explosion of the computational complexity. This issue is related here to the roles of a priori knowledge vs. adaptive learning. What is the a-priori knowledge representation that supports learning? I introduce Modeling Field Theory (MFT), a model-based neural network whose adaptive learning is based on a priori models. These models combine deterministic, fuzzy, and statistical aspects to account for a priori knowledge, its fuzzy nature, and data uncertainties. In the process of learning, a priori fuzzy concepts converge to crisp or probabilistic concepts. The MFT is a convergent dynamical system of only linear computational ...

Energy Technology Data Exchange (ETDEWEB)

An essential part of fire risk assessment is the analysis of fire hazards and fire propagation. In this work, models and tools for two different aspects of numerical fire simulation have been developed. The primary objectives have been firstly to investigate the possibility of exploiting state-of-the-art fire models within probabilistic fire risk assessments and secondly to develop a computationally efficient solver of thermal radiation for the Fire Dynamics Simulator (FDS) code. In the first part of the work, an engineering tool for probabilistic fire risk assessment has been developed. The tool can be used to perform Monte Carlo simulations of fires and is called the Probabilistic Fire Simulator (PFS). In Monte Carlo simulation, the simulations are repeated multiple times, covering the whole range of variability of the input parameters and thus resulting in a distribution of results covering what can be expected in reality. In practical ...

CERN Document Server

The recently measured experimental data of Argonne National Laboratory for high-spin states in neutron-rich $^{71,73,75,77}$Ga isotopes have been interpreted in the framework of large-scale shell model. Calculations have been performed in $f_{5/2}pg_{9/2}$ model space with two recent effective shell model interactions, JUN45 and jj44b. We also predict high-spin states for $^{79,81}$Ga, where very little is known experimentally. The calculated results show that existence of band structure built on top of the 3/2$^-$, 5/2$^-$ and 9/2$^+$ levels in $^{71-77}$Ga. The collective structure reflected in experimental data is not well reproduced in calculated values. The calculated positive parity states in $^{71,73,75}$Ga are higher in energy in comparison to experimental finding, while for $^{77,79}$Ga, the positive parity states are in better agreement. Both the interactions predict, leading configuration of ...

Science.gov (United States)

The Infrared Camera (IRC) is one of the scientific focal plane instruments on board the ASTRO-F infrared astronomical satellite. The IRC is designed for wide field imaging and slit-less spectroscopic observations at near- and mid-infrared wavelengths. The IRC consists of three channels; NIR, MIR-S and MIR-L, each of which covers wavelengths of 2-5, 5-12 and 12-26 micron, respectively. All channels adopt compact refractive optical designs. Large format array detectors (a InSb 512 x 412 array and two Si:As IBC 256 x 256 arrays) are employed. Each channel has 10 x 10 arcminutes wide FOV with diffraction-limited angular resolution of 70cm aperture of the liquid helium cooled telescope at wavelengths over 5 micron. A 6-position filter wheel is placed at the aperture stop in each channel, and has three band-pass filters, two grisms/prisms and a mask for dark current measurements. The 5 sigma sensitivity of one pointed observation is estimated to be 2, 11 and 62 micro-Jy ...

International Nuclear Information System (INIS)

For the intermetallic system CaCdsub(1-x)Tlsub(x), 0 <= x <= 1, the Knight shift Ksub(s) of the Cd-NMR and the Tl-NMR were calculated as a function of x, Ksub(s) = Ksub(s)(x). The theoretical investigations were performed on the basis of relativistic augmented-plane-wave (RAPW) band-structure calculations for the boundary phases CaCd and CaTl respectively, and by using the rigid band model for the ternary phases. The density of states and the matrix elements of the relativistic hyperfine operator for electron states at the Fermi surface were calculated in detail. The obtained values were compared with nonrelativistic calculations. The effect of using different exchange potentials was studied for Ksub(s)(Tl). For the Cd-NMR the relativistic effects enhance the nonrelativistic results by a factor of about 1.4. The theoretical value for the Knight shift is smaller than the experimental one by a factor of 1.13. The ...

International Nuclear Information System (INIS)

The #gamma#-ray spectrum emitted after thermal neutron capture in "8"7Sr was studied at the ILL high flux reactor with pair- and intrinsic Ge-spectrometers. 661 transitions were assigned to the reaction "8"7Sr(n,#gamma#)"8"8Sr and 205 of them were placed into a "8"8Sr level scheme of 47 levels. This represents 88% of the observed intensity. The level energies were determined with a precision of better than 22 ppm; the neutron binding energy was determined as 11 112.69 (22) keV. To aid the analysis high resolution particle spectra of the reaction "8"7Sr(d,p)"8"8Sr were measured at 20 MeV deuteron energy with the Munich Q3D spectrometer. 85 states were observed with this reaction. The data helped to establish newly found levels and to differentiate between primary and secondary transitions in the (n,#gamma#) data. The observed level densities and primary transition strengths are compared with statistical model predictions and ...

CERN Document Server

We consider a family of chiral non-Hermitian Gaussian random matrices in the unitarily invariant symmetry class. The eigenvalue distribution in this model is expressed in terms of Laguerre polynomials in the complex plane. These are orthogonal with respect to a non-Gaussian weight including a modified Bessel function of the second kind, and we give an elementary proof for this. In the large $n$ limit, the eigenvalue statistics at the spectral edge close to the real axis are described by the same family of kernels interpolating between Airy and Poisson that was recently found by one of the authors for the elliptic Ginibre ensemble. We conclude that this scaling limit is universal, appearing for two different non-Hermitian random matrix ensembles with unitary symmetry. As a second result we give an equivalent form for the interpolating Airy kernel in terms of a single real integral, similar to representations for the asymptotic kernel in the bulk ...

Energy Technology Data Exchange (ETDEWEB)

The deformation characteristics of pellets of electrolyte-binder (EB) mixes based on MgO were measured under simulated, thermal-battery conditions. Measurements (using a statistically designed experimental strategy) were made as a function of applied pressure, temperature, and percentage of theoretical density for four molten-salt electrolytes at two levels of MgO. The EB mixes are used as separators in Li-alloy thermal batteries. The electrolytes included LiCl-KCI eutectic, LiCl-LiBr-KBr eutectic, LiBr-KBr-LiF eutectic, and a LiCl-LiBr-LiF electrolyte with a minimum-melting composition. The melting points ranged from 313 C to 436 C. The experimental data were used to develop statistical models that approximate the deformation behavior of pellets of the various EB mixes over the range of experimental conditions we examined. This report, discusses the importance of the deformation response surfaces to thermal-battery design.

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High-spin states in the mirror pair nuclei {sup 49}Cr and {sup 49}Mn and their cross-conjugate partners, the mirror pair {sup 47}V and {sup 47}Cr have been investigated using experimental {gamma}-ray spectroscopic techniques. The combination of high-efficiency EUROBALL cluster Germanium detectors and clean exit-channel gating afforded by a 31-element silicon ball used in conjunction with a 15-detector neutron wall allowed a revision and extension to the energy level schemes of all four nuclei up to J{sup {pi}}=31{sup -}/2. The difference in excitation energy between states of equivalent spin in the parent nucleus and its analogue partner have thus been established for both mirror pairs up to the f{sub 7/2}-shell band terminating state for the first time. This difference is assumed to be due almost entirely to the Coulomb effect and is therefore called the Coulomb energy difference (CED). The variation in the CED with spin has been interpreted as reflecting the ...

International Nuclear Information System (INIS)

Photocurrent and capacitance measurements of semiconductor passive films formed on metals and alloys can be used to study the electronic properties and reveal indirect information about structure and composition. The current work used these techniques to investigate the electronic properties of the passive films formed on three austenitic stainless steels, types 304L, 316L and 254SMO, in borate. Evidence was found for the existence of a large number of localised mid bandgap states, consistent with amorphous oxides. However, the flat-band potentials of the austenitic stainless steel passive films were found to be independent of both composition and measuring frequency. The most credible explanation for the bandgap values determined from photocurrent measurements is that the passive films are formed as dual layers, iron oxide outer layer and chromium oxide inner layer. This model does not need to evoke the potential dependent bandgaps used by ...

Energy Technology Data Exchange (ETDEWEB)

Passive films formed on Alloy 690 in different pH solutions at high temperatures were studied by potentiodynamic polarization, Auger electron spectroscopy, thermodynamic diagrams and the Mott-Schottky relation. The chemical compositions and electronic structures of the passive films were found to be strongly pH-dependent. In alkaline solutions, a secondary passivation was clearly observed on potentiodynamic polarization curves. The passive films were a mixture of Cr{sub 2}O{sub 3} and FeCr{sub 2}O{sub 4} below the flat band potential of nickel oxide and were NiFe{sub 2}O{sub 4} above this potential. Electronic structure models, describing the electrochemical properties of the passive films, are proposed and discussed.

International Nuclear Information System (INIS)

Cluster calculations of the electronic structure and charge distribution in V_3Si have been performed using two different molecular orbital methods: a semiempirical LCAO and the MS X#alpha# model. The results are compared with X-ray emission spectra and band structure calculations. An analysis of the calculated electronic distribution reveals a charge transfer from Si-atoms to V-atoms, the additional charge on a V-atom being 0.6e (LCAO) and 0.4e (MS X#alpha# method). The results are in good agreement with experiment, which indicates that the cluster approach is adequate for the description of charge distributions and spectra characteristics of the A-15 compounds. (author).

British Library Electronic Table of Contents (United Kingdom)

We report the first band structure calculations of the quasi-one-dimensional [MnTPP][TCNE] compounds (TPP?=?meso-tetraphenylporphyrinato, TCNE?=?tetracyanoethylene), based on Density Functional Theory (DFT) methods, in order to interpret the magnetic ordering in these prototypic systems. We compare and contrast the results of broken-symmetry DFT calculations for extended systems, with periodic boundary conditions, and for finite systems, magnetic dimers modeling the actual molecular magnets. By varying systematically the main angles, we are able to determine the geometry dependence of the exchange interaction. Structure?properties correlations in these charge-transfer salts reveal the determinant role of the Mn-(N?C)TCNE bond angle on the strength of the ferrimagnetic coupling between the ...

Energy Technology Data Exchange (ETDEWEB)

Spectroscopy based on the Andreev reflection (AR) process at the interface between the normal metal tip and the superconductor has become one of the very successful methods for studies in novel exotic superconductors. The method is capable to address the size, symmetry as well as multiplicity of the superconducting order parameter. The method provided one of the first evidences of the two-gap superconductivity in MgB{sub 2} with a detailed temperature dependence of the both gaps. A theory treating the Andreev reflection spectroscopy in the mixed state is missing. We analyse the AR spectra of MgB{sub 2} in the mixed state via modelling the magnetic pair-breaking by the increasing spectral broadening parameter {gamma}. As a result a non-trivial pair breaking effect in the {pi}-band is found.

International Nuclear Information System (INIS)

This study develops a statistical model of industrial US natural gas consumption based upon historical data for the 1958-2003 period. The model specifically addresses interfuel substitution possibilities and changes in the industrial economic base. Using a relatively simple approach, the framework can be simulated repeatedly with little effort over a range of different conditions. It may also provide a valuable input into larger modeling exercises where an organization wants to determine long-run natural gas prices based upon supply and demand conditions. Projections based upon this demand framework indicate that industrial natural gas consumption may grow more slowly over the next 20 yr than being projected by the U.S. Energy Information Administration (EIA). This conclusion is based upon the assumption that natural gas prices will follow oil prices, as they have done over recent decades. If natural ...

Energy Technology Data Exchange (ETDEWEB)

A contamination event in a water distribution system can result in adverse health impacts to individuals consuming contaminated water from the system. Assessing impacts to such consumers requires accounting for the timing of exposures of individuals to tap-water contaminants that have time-varying concentrations. Here we present a probabilistic model for the timing of ingestion of tap water that we developed for use in the U.S. Environmental Protection Agency's Threat Ensemble Vulnerability Assessment and Sensor Placement Tool, which is designed to perform consequence assessments for contamination events in water distribution systems. We also present a statistical analysis of the timing of ingestion activity using data collected by the American Time Use Survey. The results of the analysis provide the basis for our model, which accounts for individual variability in ingestion timing and provides a series of ...

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KoreaScience (Korea)

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Science.gov (United States)

The spectral dependences of absorption photoinduced in a pure bismuth titanium oxide crystal by 532-nm laser pulses are studied. It is shown that optical absorption in the crystal in the range from 492 to 840 nm increases with increasing exposure. The photoinduced absorption relaxes in the dark for more than 60 hours. A model of photoinduced absorption is proposed which assumes the population of two trap centres with the normal energy distribution law for the concentrations of electrons photoexcited from donors to the conduction band. This model well describes the spectral dependences of photoinduced absorption by using the average ionisation energies of the traps E{sub 1} = 1.60 eV and E{sub 2} = 2.57 eV. The model is used to estimate the increase in the photorefractive sensitivity of a bismuth titanium oxide crystal in the near IR region, which was earlier observed after exposing the crystal to ...

Energy Technology Data Exchange (ETDEWEB)

Subsurface and surface coalfires are a serious problem in many coal-producing countries. Combustion can occur within the coal seams (underground or surface), in piles of stored coal, or in spoil dumps at the surface. While consuming a non renewable energy source, coalfires promote several environmental problems. Among all GHGs that are emitted from coalfires, CO2 is the most significant because of its high quantity. In connection to this environmental problem, the core aim of the present research is to develop a hyperspectral remote sensing and radiative transfer based model that is able to estimate CO2 concentration (ppmv) from coalfires. Since 1960s remote sensing is being used as a tool to detect and monitoring coalfires. With time, remote sensing has proven a reliable tool to identify and monitor coalfires. In the present study multi-temporal, multi-sensor and multi-spectral thermal remote sensing data are being used to detect and monitor coalfires. Unlike the ...

Science.gov (United States)

Removal Sampling is an easy-to-use Windows program which calculates population statistics from removal trapping experiment data. Using maximum likelihood methods it ... ...

Energy Technology Data Exchange (ETDEWEB)

We consider the Pauli theorem on the spin-statistics connection for faster-than-light particles. As the consequence of the unlocalizability of tachyons in space we conclude that their spin-statistics correlations are inverted.

Energy Technology Data Exchange (ETDEWEB)

Band-structure studies of NbN and VN are reported. The results of angle-resolved photoemission experiments performed on NbN/sub 0.93/ and VN/sub 0.89/ are presented. The bulk-band structures calculated for stoichiometric NbN and VN using the linearized augmented-plane-wave method are presented and utilized in the interpretation of the experimental spectra. It is shown that most of the features in the spectra can be accounted for by direct bulk-band transitions. A fairly good agreement between experimental and calculated band locations and dispersions is obtained.

Energy Technology Data Exchange (ETDEWEB)

This paper presents a stochastic model and estimation procedure for analyzing the failure process of a repairable system. We consider repairable systems whose successive interfailure times reveal a significant dependence while showing an insignificant trend. Neither the renewal process nor the non-homogeneous Poisson process are adequate for modeling such failure processes. Especially when the interfailure times show a cyclic pattern, we may consider a switching of the regimes (states) governing the lifetime distribution of the system. We propose a Markov switching model describing the failure process for such a case. The model postulates that a finite number of states governs the distinct lifetime distributions, and the state makes transitions according to a discrete-time Markov chain. Each of the distinct lifetime distributions represents a failure type that may change after successive repairs. Our ...

Energy Technology Data Exchange (ETDEWEB)

Environmental exposure measurements are, in general, positive and may be subject to left censoring; i.e,. the measured value is less than a ''detection limit''. In occupational monitoring, strategies for assessing workplace exposures typically focus on the mean exposure level or the probability that any measurement exceeds a limit. Parametric methods used to determine acceptable levels of exposure, are often based on a two parameter lognormal distribution. The mean exposure level, an upper percentile, and the exceedance fraction are used to characterize exposure levels, and confidence limits are used to describe the uncertainty in these estimates. Statistical methods for random samples (without non-detects) from the lognormal distribution are well known for each of these situations. In this report, methods for estimating these quantities based on the maximum likelihood method for randomly left censored lognormal data are ...

Energy Technology Data Exchange (ETDEWEB)

We present theoretical calculations for the production of the long-lived isomers: {sup 121m}Sn (11/2-, 55 yr), {sup 166m}Ho(7-, 1200 yr), {sup 184m}Re(8+, 165 d), {sup 186m}Re(8+, 2{times}10{sup 5} yr), {sup 178m}Hf(16+, 31 yr), {sup 179m}Hf(25/2-, 25 d), {sup 192m}Ir(9+, 241 yr), all which pose potential radiation activation problems in nuclear fusion reactors if produced in 14-MeV neutron-induced reactions. We consider mainly (n,2n) production modes, but also (n,n{sup {prime}}) and (n,{gamma}) where necessary, and compare our results both with experimental data (where available) and systematics. We also investigate the dependence of the isomeric cross section ratio on incident neutron energy for the isomers under consideration. The statistical Hauser-Feshbach plus preequilibrium code GNASH was used for the calculations. Where discrete state experimental information was lacking, rotational band members above the isomeric state, which can be ...

Energy Technology Data Exchange (ETDEWEB)

New York City data indicate that seasonal and annual variations in dispersion-normalized air pollutant concentrations appear to accurately reflect changes in source emission patterns. The normalized concentrations make it possible to observe the impact of regulatory changes on ambient air quality without these impacts being obscured by meteorological fluctuations. It is found that numerical modeling techniques and regression analysis can be powerful tools for extracting information from large sets of air quality data. The use of differential, as opposed to absolute, pollutant concentration values will reduce artifact correlations caused by seasonal, weekly, or daily meteorological fluctuations and will permit more accurate estimation of the regression coefficients. This technique was successfully applied to a set of daily pollution measurements whose absolute concentrations were found not to yield a statistically significant fit by multiple ...

International Nuclear Information System (INIS)

The evolution of metallic substance atomic structure is studied on temperature variation including crystal heating up to melting points, a crystal- liquid phase transition and initiation of a high-density liquid specific structure. It is marked that heat induced changes of simple metal structure can be described as changes around a natural elementary cell which is common for both a crystal and a liquid and consists of a central atom and Z_1 atoms of the first coordination sphere. On this basis the vacancy model of melting is verified. Concentrations of melting vacancies are determined by coordination numbers in the form of Z_1/(1+Z_1)"2 which are the same for both a crystal and a natural elementary cell. The size of natural elementary cells is in an agreement with that of the coordination sphere featured in the liquid and phase transition statistical theory. Calculated data are given for a number of metals, Cs, Eu, Ni, V included

British Library Electronic Table of Contents (United Kingdom)

We examine the short-term price behaviour of three, size-conditioned Indian stock market indices, in response to informational shocks. A standard mean-adjusted returns model as well as the GJR-GARCH specification point towards underreaction to negative events in the medium and small capitalization indices. Also, the pre-event coefficients are generally negative and statistically significant, regardless of the sign of the shock, thus ruling out information leaks. We uncover a stable abnormal volatility pattern which increases monotonically a few days before the shock before suddenly decreasing in magnitude on the event day and beyond. We suggest uncertainty avoidance as a potential explanation of these features. The results are fairly robust across alternative event selection procedures, ti...

International Nuclear Information System (INIS)

Potassium clusters arrayed in zeolite A are known to show ferromagnetic properties at low temperature. The origin of the spontaneous magnetization has been explained by a model of spin-canting in an antiferromagnetically ordered state. The direct information for the magnetic structure, however, has not been obtained so far. In the present work, we measure the neutron powder diffraction by using pulsed neutron source at KEK-KENS below and above the Curie temperature. No significant temperature-dependence was, however, obtained within the statistical errors, namely, magnetic scattering could not be detected separately. We also estimate the intensity of magnetic scattering by assuming some possible magnetic structures with considering the magnetic form factor of the cluster wave function. The intensity of magnetic scattering is estimated to be extremely weak and higher S/N of ?104 or more is required to detect the magnetic scattering of this ...

CERN Document Server

substrate). Within each group of simulations, three lubricant film thicknesses are studied to examine the effect of varying lubricant thickness. Statistical data are collected from each simulation and presented in this work. Via these data, together with the evolution, of atomic and molecular configurations, a very detailed picture of the properties of this thin film interface is presented. In particular, we conclude that perfluoropolyether lubricant forms distinct molecular layers when confined between two substrates, the rate of heat generation under shearing conditions typical of those in a head-disk interface is insufficient for thermal mechanisms to result directly in lubricant degradation, and mechanical stresses attained in the head-disk interface are unlikely to result in any significant degree of lubricant degradation. This thesis examines the tribology of a head-disk interface in an operating hard disk drive via non-equilibrium molecular dynamics computer ...

Science.gov (United States)

A multivariate bioprocess control approach, capable of tracking a pre-set process trajectory correlated to the biomass or product concentration in the bioprocess is described. The trajectory was either a latent variable derived from multivariate statistical process monitoring (MSPC) based on partial least squares (PLS) modeling, or the absolute value of the process variable. In the control algorithm the substrate feed pump rate was calculated from on-line analyzer data. The only parameters needed were the substrate feed concentration and the substrate yield of the growth-limiting substrate. On-line near-infrared spectroscopy data were used to demonstrate the performance of the control algorithm on an Escherichia coli fed-batch cultivation for tryptophan production. The controller showed good ability to track a defined biomass trajectory during varying process dynamics. The robustness of the control was high, despite significant external ...

Energy Technology Data Exchange (ETDEWEB)

Computational transport models are described with applications in three problem areas related to unsaturated zone moisture movement beneath Area G. These studies may be used to support the ongoing maintenance of the site Performance Assessment. The three areas include: a 1-D transient analysis with average tuff hydraulic properties in the near surface region with computed results compared to field data; the influence on near surface transient moisture percolation due to realistic distributions in hydraulic properties derived statistically from the observed variance in the field data; and the west to east moisture flow in a 2-D steady geometry approximation of the Pajarito Plateau. Results indicate that a simple transient model for transport of moisture volume fraction fits field data well compared to a moisture pulse observed in the active disposal unit, pit 37. Using realistic infiltration boundary conditions for summer ...

International Nuclear Information System (INIS)

The isostructural #gamma#-#alpha# phase transition of Ce which occurs at 8 kbar has been studied by means of fully self-consistent (non-muffin-tin potential) linearized-augmented-plane-wave energy band calculations carried out for five different values of the lattice constant. In contradiction to the 4f electron promotional model of the transition, the results yield essentially one 4f electron to be occupied in each phase but with the 4f wave function somewhat less localized, and therefore more bandlike, in the ''collapsed'' #alpha# phase. A singly occupied 4f state is shown to be consistent with the available experimental data. These results strongly support the picture of a 4f localized bold-arrow-left-right itinerant transition at the #gamma#-#alpha# transition and conflict with the promotional model in which some fraction of 4f electrons are transferred to the sd conduction bands. The weaker bonding ...

Energy Technology Data Exchange (ETDEWEB)

The linear/supralinear behaviour of the TL dose response in LiF:Mg,Ti (TLD-100) and its dependence on ionisation density is a fairly unique phenomenon which cannot be explained by conventional atomic 'conduction band/valence band' kinetic models. The Track Interaction Model (TIM) provides the microscopic framework which, when coupled with other appropriate physical mechanisms (spatial localisation of traps and recombination centres, competing centres, variations in the capture cross sections with temperature, etc.) can be used to describe all the dominant features of the TL supralinearity of LiF:Mg,Ti and similar TL systems. The unique feature of the TIM applied to alpha particles is that it is an integral approach with only one free parameter, the average charge carrier migration distance in the luminescence recombination stage. Although the TIM provides a comprehensive description of ...

Energy Technology Data Exchange (ETDEWEB)

The differential cross sections for neutron emission in the reactions {sup 115}In(p,xn), {sup 115}In(d,xn), and {sup 113}Cd({alpha},xn) are measured and analyzed for proton energies 11.2 and 22.2 MeV, deuteron energy 22.3 MeV, and {alpha}-particle energies 26.8 and 45.2 MeV, respectively. The parameters of the nuclear-level density in the Fermi-gas model with negative energy shift are determined for the {sup 113}Sn, {sup 114}Sn, {sup 115}Sn, and {sup 116}Sn nuclei over a wide range of excitation energies. Analysis is performed in a statistical model that uses the Hauser-Feshbach mathematical formalism to describe multistage processes. It is shown that, as excitation energy increases, the parameter of the level density for these nuclei first decreases (this behavior is consistent with the predictions of the generalized model of a superfluid nucleus) and then increases (this points to the destruction of ...

CERN Document Server

Evaluation of nuclear data has been performed for sup 2 sup 3 sup 7 Np, sup 2 sup 4 sup 1 Am, sup 2 sup 4 sup 2 sup g Am and sup 2 sup 4 sup 2 sup m Am. Neutron data were obtained at energies from 20 to 250 MeV and combined with JENDL-3.3 data at 20 MeV. Evaluation of the proton data has been done from 1 to 250 MeV. The coupled channel optical model was used to obtain angular distributions for elastic and inelastic scattering and transmission coefficients. Pre-equilibrium exciton model and Hauser-Feshbach statistical model were used to describe neutron and charged particles emission from excited nuclei. These evaluation is the first work for producing full sets of evaluated file up to 250 MeV for sup 2 sup 3 sup 7 Np and Americium isotopes.

Energy Technology Data Exchange (ETDEWEB)

This doctoral thesis addresses some problems in the analysis of spatial and spatial-temporal data and discusses prediction, prediction errors and identification of emission sources. European sulphur data are used as illustration. In an investigation of a spatial-temporal decomposition model for improving estimates of spatial interpolation (prediction) errors from monitoring data, the estimates were improved compared to estimates obtained by the method known as Kriging (an extension of the Wiener-Kolmogorov theory from time series to spatial processes), although the interpolated values were quite similar. A study of a random process model with an unknown, slowly varying trend and a correlated residual process is performed, using both trend estimation (smoothing) and prediction. Local polynomial methods are extended to continuous random processes. A new approach to non-parametric smoothing and to non-parametric Kriging is described. Finally, a ...

International Nuclear Information System (INIS)

Research highlights: #-># The building occupancy affecting the cooling load prediction is studied. #-># PENN model is adopted in this study for predicting the building cooling load. #-># Statistical approach is adopted to result a less prejudice prediction performance. #-># Results show that occupancy data can significantly improve the prediction. -- Abstract: Building cooling load prediction is one of the key factors in the success of energy-saving measures. Many computational models available in the industry today have been developed from either forward or inverse modeling approaches. However, most of these models require extensive computer resources and involve lengthy computation. This paper discusses the use of data-driven intelligent approaches, a probabilistic entropy-based neural (PENN) model to predict the cooling load of a building. ...

Science.gov (United States)

... Note that the terminal ... Probability and Statistics with Reliability, Queueing, and Computer ... Weiss, G., "Stochastic Bounds on Distributions of Optimal ...

Wastenet

environmental burden is studied by testing the Environmental Kuznets Curve hypothesis as well as application of statistical decomposition

CERN Document Server

The principal paradigm for gamma-ray bursts (GRBs) suggests that the prompt transient gamma-ray signal arises from multiple shocks internal to the relativistic expansion. This paper explores how GRB prompt emission spectra can constrain electron (or ion) acceleration properties at the relativistic shocks that pertain to GRB models. The array of possible high-energy power-law indices in accelerated populations is highlighted, focusing on how spectra above 1 MeV can probe the field obliquity in GRB internal shocks, and the character of hydromagnetic turbulence in their environs. When encompassing the MeV-band spectral break, fits to BATSE/EGRET burst data indicate that the preponderance of electrons responsible for the prompt emission reside in an intrinsically non-thermal population. This differs markedly from typical populations generated in acceleration simulations; potential resolutions of this conflict such as the action of self-absorption ...

Energy Technology Data Exchange (ETDEWEB)

Tantalum and tantalum-based thin films have gained precedence as the diffusion barrier for copper interconnects used in the latest generation of integrated circuits (ICs). The paper presents insight and observations on the covariance of texture and grain size of wrought tantalum sputtering targets and their influence on sputtering performance. Previous studies involving deposition trials of tantalum targets of varying metallurgical character had demonstrated that both grain size and textural homogeneity is critical for assuring reliable sputtering performance of tantalum. Subsequently, a model had been proposed to prescribe how localized texture bands and orientation clusters in tantalum are effectively resistant to sputter erosion. In this paper, results of atomic force microscopy (AFM) and orientation imaging microscopy (OIM{sup TM}) analyses on the eroded surface of a tantalum sputtering target are presented. Initial findings support the ...

Science.gov (United States)

The spread spectrum acquisition and tracking performance for the Shuttle S-band and Ku-band communication links are analyzed and compared to test results. The S-band link requirements are more severe than those of the Ku-band links, hence, different despreader designs were developed for the two systems. The S-band despreader acquires pseudonoise code lock by examining all possible code phases in half chip steps while the Ku-band despreader acquires pseudonoise code lock by continuously sweeping a tau-jitter loop. Both despreaders employ a tau-jitter loop for code tracking. The code tracking performance is computed for the tau-jitter loop and compared to that of the more complex delay lock loop.

Energy Technology Data Exchange (ETDEWEB)

As the penetration of wind energy continues to increase around the world, with a trend towards large utility-scale wind farms (greater than 100 MW), effective wind energy forecasting will become increasingly important. Previous work by GH has estimated the trading benefit of high quality short-term forecasting to be EUR 7/MWh. Depending on market conditions, for a 100 MW wind farm with a capacity factor of 30%, this equates to an estimated annual trading benefit of up to EUR 1.8m. To date, a number of studies have focused on the mathematical modelling techniques for forecasting the production from wind farms, looking predominantly at the task of predicting the meteorological conditions at the site. This paper focuses on the final stage of the forecasting process, conversion from a meteorological forecast to a power production forecast. This challenge is particularly significant for utility-scale wind farms. The main body of research in short-term forecasting in ...

Energy Technology Data Exchange (ETDEWEB)

The growing concern of the population with regards to the problem of atmospheric pollution has induced a change in the role of air quality monitoring networks, especially those monitoring air pollution in large cities which suffer from summer smog. The population is no longer satisfied with real-time measurements but wants to be warmed of high pollutants concentrations in advance. Some countries have been forecasting air pollution, and especially ozone, for a large number of years. Although most of them use statistical models based on the analyses of past conditions which induced high pollution episodes, some predict ozone levels using only their knowledge of the meteorological situation. Nowadays two trends appear regarding ozone forecasting: either very basic statistical methods, such as regression, or more sophisticated ones, such as neural networks. The paper then reviews several behaviours common to most forecasting ...

Science.gov (United States)

Over the recent years the nuclear structure around the N = 50 shell closure, which is very pronounced in the strontium and zirconium isotopes, has been the subject of extensive experimental and theoretical work. On the proton side Z = 38 and Z = 40 provide fairly closed sub-shells. In the strontium isotopes the lg/sub 9/2/ neutron shell is closed at /sup 88/Sr, supplying relatively pure neutron-hole and neutron-particle states with large spectroscopic factors in /sup 87/Sr and /sup 89/Sr, as well as core-coupled states. The mass region is thus ideally suited to examine the transition from a correlated to an uncorrelated (chaotic.) excitational behavior. These two types are characterized e.g. by the density of excited states, the transition strengths, and the spectroscopic factors observed in transfer reactions. We conducted (n,..gamma..) and (d,p) reactions leading to /sup 87,88,89/Sr in addition to /sup 88/Sr(d,t)/sup 87/Sr and 24 keV neutron capture in /sup 88/Sr. The vast amounts of ...

International Nuclear Information System (INIS)

Monte Carlo simulation of beam modifiers such as physical wedges and compensating filters has been performed with a rectilinear voxel geometry module. A modified version of the EGS4/DOSXYZ code has been developed for this purpose. The new implementations have been validated against the BEAM Monte Carlo code using its standard component modules (CMs) in several geometrical conditions. No significant disagreements were found within the statistical errors of 0.5% for photons and 2% for electrons. The clinical applicability and flexibility of the new version of the code has been assessed through an extensive verification versus dosimetric data. Both Varian multi-leaf collimator (MLC) wedges and standard wedges have been simulated and compared against experiments for 6 MV photon beams and different field sizes. Good agreement was found between calculated and measured depth doses and lateral dose profiles along both wedged and unwedged directions for different depths and ...

Energy Technology Data Exchange (ETDEWEB)

Lithium isotope separation by displacement chromatography is studied using fundamental principles; the equations are derived assuming theoretical stages in lithium adsorption bands. The concentration profiles in the band are calculated numerically under unsteady state.

Science.gov (United States)

... to-noise density than the uplink budget has (74.2 ... in heav:, point-to-point link applications with ... 11.7 Expanded bands allocated (Ku band) (500 MHz ...

CERN Document Server

Extracting useful information from high-dimensional data is an important focus of today's statistical research and practice. Penalized loss function minimization has been shown to be effective for this task both theoretically and empirically. With the virtues of both regularization and sparsity, the $L_1$-penalized squared error minimization method Lasso has been popular in regression models and beyond. In this paper, we combine different norms including $L_1$ to form an intelligent penalty in order to add side information to the fitting of a regression or classification model to obtain reasonable estimates. Specifically, we introduce the Composite Absolute Penalties (CAP) family, which allows given grouping and hierarchical relationships between the predictors to be expressed. CAP penalties are built by defining groups and combining the properties of norm penalties at the across-group and within-group levels. Grouped ...

British Library Electronic Table of Contents (United Kingdom)

Background The relationships between coffee, tea, and sugar-sweetened carbonated soft drink consumption and colon cancer risk remain unresolved. Methods We investigated prospectively the association between coffee, tea, and sugar-sweetened carbonated soft drink consumption and colon cancer risk in a pooled analysis of primary data from 13 cohort studies. Among 731 441 participants followed for up to 6-20 years, 5604 incident colon cancer case patients were identified. Study-specific relative risks (RRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models and then pooled using a random-effects model. All statistical tests were two-sided. Results Compared with nonconsumers, the pooled multivariable relative risks were 1.07 (95% CI = 0.89 to 1.30, Ptrend = ...

Energy Technology Data Exchange (ETDEWEB)

Independent isomeric yield ratios of /sup 128/Sb were determined radiochemically in the thermal neutron induced fission of /sup 241/Pu and 34 MeV alpha particle induced fission of /sup 238/U, both involving the same compound nucleus (/sup 242/Pu). Fragment angular momenta estimated from the measured isomer ratios using the statistical model analysis showed significantly larger fragment angular momenta in the medium energy fissioning system compared to the low energy fissioning system. This has been attributed to the effect of higher excitation energy and angular momentum in the entrance channel leading to increased fragment temperature, moments of inertia and angular velocity. An attempt was made to calculate the fragment angular momentum in the medium energy fission using the Fermi gas model for the fissioning nucleus, taking into account the multichance fission, saddle shapes of the fissioning nuclei and the angular ...

CERN Document Server

We compare the predictions of four different algorithms for the distribution of ionized gas during the Epoch of Reionization. These algorithms are all used to run a 100 Mpc/h simulation of reionization with the same initial conditions. Two of the algorithms are state-of-the-art ray-tracing radiative transfer codes that use disparate methods to calculate the ionization history. The other two algorithms are fast but more approximate schemes based on iterative application of a smoothing filter to the underlying source and density fields. We compare these algorithms' resulting ionization and 21 cm fields using several different statistical measures. The two radiative transfer schemes are in excellent agreement with each other (with the cross-correlation coefficient of the ionization fields >0.8 for k 0.6 for k < 1 h/Mpc). When used to predict the 21cm power spectrum at different times during reionization, all ionization algorithms agree with one another at the ...

Science.gov (United States)

A statistical method is presented for detecting quantitative trait loci (QTLs), based on the linear model. Unlike methods able to detect a few well separated QTLs and to estimate their effects and positions, this method considers the genome as a whole and enables the detection of chromosomal segments involved in the differences between two homozygous lines, and their backcross, doubled haploid, or F[sub 2] progenies, for a quantitative trait. Genetic markers must be codominant, but missing markers are accepted, provided they are missing independently from the experiment. Asymptotic properties, which are of practical use, are developed. This method does not rely on strong genetic hypotheses, and thus does not permit any precise genetic analysis of the trait under study, but it does assess which regions of the genome are involved, whatever the complexity of the genetic determinism (number, effects and interactions among QTLs). Simultaneous use of ...

Energy Technology Data Exchange (ETDEWEB)

As part of studies into the siting of a deep repository for nuclear waste, Swedish Nuclear Fuel and Waste Management Company (SKB) has commissioned the Alternative Models Project (AMP). The AMP is a comparison of three alternative modeling approaches for geosphere performance assessment for a single hypothetical site. The hypothetical site, arbitrarily named Aberg is based on parameters from the Aespoe Hard Rock Laboratory in southern Sweden. The Aberg model domain, boundary conditions and canister locations are defined as a common reference case to facilitate comparisons between approaches. This report presents the results of a discrete fracture pathways analysis of the Aberg site, within the context of the SR 97 performance assessment exercise. The Aberg discrete fracture network (DFN) site model is based on consensus Aberg parameters related to the Aespoe HRL site. Discrete fracture pathways are ...

Energy Technology Data Exchange (ETDEWEB)

We present the results of a comprehensive study of the temperature dependences of the quantum efficiency for ultraviolet detectors based on GaAs, GaP and 4H--SiC Schottky structures, and on Si, GaAs p-n structures. For ultraviolet detectors based on Schottky structures, the quantum efficiency increases with increasing temperature for all photon energies, even including the semiconductor intrinsic absorption region. On the other hand, for ultraviolet detectors based on p-n structures, the quantum efficiency is practically temperature independent in the semiconductor intrinsic absorption region. The change in the quantum efficiency for the GaAs and Si detectors is less than 0.01% per degree. To explain the measurements, a variable trap occupancy model is presented. Subsurface imperfections of the semiconductor cause fluctuations in the profile of the conduction band and the valence band edges. In the presence of an electric ...

Science.gov (United States)

Multicellular tumor spheroids (MCTS) are three dimensional cell culture systems induced by suspension culture. MCTS are widely used in cancer research because of their similarity to solid tumors. CaSki cells are derived from a metastatic cervical cancer containing human papillomavirus 16 (HPV16). Cell death of CaSki cells in MCTS has been previously reported, and our model is used to better characterize the mechanisms of cell death of HPV16-positive keratinocytes. In this study, we found that apoptosis of CaSki cells was induced by suspension culture along with the formation of MCTS after 24 h of incubation. In suspended CaSki cells, monoclonal antibodies blocking E-cadherin function inhibited MCTS formation and suppressed suspension-induced apoptosis in a dose-dependent manner. Western blot for E-cadherin detected upregulation of the authentic 120 kDa band from MCTS of CaSki cells as well as a shorter 100 kDa band. ...

International Nuclear Information System (INIS)

In the present paper we estimate the effect of sodium in the in-service inspection of non-magnetic steam generators tubes using eddy current technique and eddy current probes based on a differential double bobbin coil configuration. Experimental measurements of defects signals in steam generator tubes of fast breeder reactor are compared with simulations results of a two-dimensional axisymmetric finite element code to validate a reliable electromagnetic model of the system (eddy current coils, steam generator tube, defect) when there is no sodium on the outer steam generator tube surface. The electromagnetic code is used to evaluate the sodium band and sodium layer signals when a defect is located under steam generator support plate. Using a multi-frequency algorithm, its parameters are determined in the 'no sodium condition' (there is no sodium on the outer steam generator tube surface), defects signal is enhanced during eddy currents ...

International Nuclear Information System (INIS)

... deformed nuclei eigenvalues even-odd nuclei gold 195 hamiltonians iridium

Energy Technology Data Exchange (ETDEWEB)

Lifetimes have been measured in the {pi}h{sub 9/2} (yrast) and {pi}i{sub 13/2} (excited) bands in the nuclei {sup 181}Ir and {sup 187}Au using the Recoil Distance Method (RDM). The results clearly indicate that the {pi}i{sub 13/2} band exhibits an increased deformation over the {pi}h{sub 9/2} band, in keeping with the premise that the delayed crossing in this band is due to enhanced quadrupole deformation. (author). 3 refs, 1 fig, 2 tab.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

Forests on the Kola Peninsula in Northern Russia grow close to the northern tree line. They are subjected to both natural and anthropogenic stress factors. The Cu-Ni smelter 'Severonikel' (Lat. 67 deg 55'N; Long. 32 deg 57'E) near Monchegorsk is one of the two major sources of sulphur dioxide and heavy metals emissions on the Kola Peninsula. These emissions have caused significant deterioration of the surrounding vegetation. The thesis demonstrates how methods of Remote sensing, ground survey and mathematical modelling can be integrated for monitoring of the smelter's environmental impact on the surrounding vegetation: ground truth data are used for calibration of remote-sensed data, which further serve to verify mathematical models. The study aims were: * to estimate the scale of airborne sulphur pollution from the smelting industry on the Kola Peninsula and its effect on vegetation; * to assess ...

Science.gov (United States)

As part of the Wisconsin road weather safety initiative, the objective of this study is to assess the effects of rainfall on the severity of single-vehicle crashes on Wisconsin interstate highways utilizing polychotomous response models. Weather-related factors considered in this study include estimated rainfall intensity for 15 min prior to a crash occurrence, water film depth, temperature, wind speed/direction, stopping sight distance and deficiency of car-following distance at the crash moment. For locations with unknown weather information, data were interpolated using the inverse squared distance method. Non-weather factors such as road geometrics, traffic conditions, collision types, vehicle types, and driver and temporal attributes were also considered. Two types of polychotomous response models were compared: ordinal logistic and sequential logistic regressions. The sequential logistic regression was tested with forward and backward ...

International Nuclear Information System (INIS)

We report the discovery of an active galactic nucleus (AGN) pair in the interacting galaxy system IRAS 20210+1121 at z = 0.056. An XMM-Newton observation reveals the presence of an obscured (N _H #approx# 5 x 10"2"3 cm"-"2), Seyfert-like (L _2_-_1_0_k_e_V = 4.7 x 10"4"2 erg s"-"1) nucleus in the northern galaxy, which lacks unambiguous optical AGN signatures. Our spectral analysis also provides strong evidence that the IR-luminous southern galaxy hosts a Type 2 quasar embedded in a bright starburst emission. In particular, the X-ray primary continuum from the nucleus appears totally depressed in the XMM-Newton band as expected in the case of a Compton-thick absorber, and only the emission produced by Compton scattering ('reflection') of the continuum from circumnuclear matter is seen. As such, IRAS 20210+1121 seems to provide an excellent opportunity to witness a key, early phase in the quasar evolution predicted by the theoretical models of ...

Energy Technology Data Exchange (ETDEWEB)

FT-IR spectroscopic studies of the adsorption of natural and {sup 18}O-enriched NO gases on thermally and cleaned MgO powders were carried out. The temperature dependence of the IR spectra was investigated to characterize the adsorbate species. Three types [1, 2, and 3] of NO adsorptions were obtained in the wavenumber region of 1500--1000 cm{sup {minus}1}. Those types were examined using density functional theory [(U)B3-LYP/6-31G*] vibrational analyses of (MgO){sub n}-NO cluster calculations. Types 1, 2, and 3 were assigned to monodentate, asymmetric, and symmetric bidentate geometries, respectively. A type 4, a tridentate model which involves a NO{sub 3}-like species, was calculated and was found to give wavenumbers of less than 1,000 cm{sup {minus}1}. The splitting of IR bands of type 3 due to the {sup 15}N{sup 18}O adsorbate was ascribed to the oxygen exchange, {sup 15}N{sup 18}O {yields} {sup 15}N{sup 16}O, via the reaction {sup 16}O-{sup ...

CERN Document Server

The nature of the hard X-ray source XSSJ12270-4859 is still unclear though it was claimed to be a magnetic Cataclysmic Variable. We here present a broad-band X-ray and gamma ray study based on a recent XMM-Newton observation and archival INTEGRAL and RXTE data. From the Fermi/LAT 1-year point source catalogue, we tentatively associate XSSJ12270-4859 with 1FGLJ1227.9-4852, a source of high energy gamma rays with emission up to 10GeV. We complement the study with UV photometry from XMM-Newton and ground-based optical and near-IR photometry. The X-ray emission is highly variable showing flares and intensity dips. The X-ray flares consist of flare-dip pairs. Flares are also detected in the UV range but not the dips. Aperiodic dipping behaviour is also observed during X-ray quiescence but not in the UV. The 0.2-100keV spectrum is featureless and described by a power law model with Gamma=1.7. The 100MeV-10GeV spectrum is instead represented by a ...

Science.gov (United States)

The millimeter microwave source of gyrotron-traveling-wave amplifier (gyro-TWT) is capable of generating high power coherent radiation in a broad bandwidth, while its performance is severely deteriorated by the stability problems. This paper focuses on modeling and the stability analysis of the Naval Research Laboratory (NRL) Ka-band TE{sub 01} mode gyro-TWT based on an interaction circuit alternately loaded with lossy ceramic shells and metal rings. The propagation characteristics of the interaction circuit is analyzed first, based on which the boundary impedance method is employed to build an equivalent uniform lossy circuit. Then the stability of the interaction system is studied using linear and nonlinear theories. The analysis reveals that, due to the special waveguide structure and the dielectric loss, the propagation characteristics of the complex waveguide are similar to that of a uniform lossy circuit. The analysis of the absolute ...

International Nuclear Information System (INIS)

In conducting aircraft surveys for uranium, it is found that temperature inversions can give spurious results because they promote accumulation of radon gas in the atmosphere. The "2"1"4Bi (daughter product of radon) gamma-rays detected from the atmosphere-borne radon are difficult to separate from the "2"1"4Bi gamma-rays originating from the ground, and providing a signature for uranium deposits. The purpose of the present study was to examine the feasibility of making remote temperature soundings of the atmosphere below a low-flying aircraft (140 m or less above ground) by the inversion of radiance measurements taken in the 15-micron carbon dioxide absorption band. Such measurements would identify those temperature inversion conditions possibly leading to an unacceptably large background of gamma-rays from the atmospheric radon. Thus, the incidence of spurious aerial survey data could be greatly reduced. An atmospheric model was set up and ...