Science.gov (United States)

We present a simple and intuitive derivation of the track parameter covariance matrix due to multiple Coulomb scattering for use in track fitting with the Kalman filter. We derive all the covariance matrix elements for two experimentally relevant track parameterizations (i.e. x and y slopes and intercepts, and direction cosines and intercepts) in the presence of thin scatterers and absence of magnetic fields. We further comment on how to account for thick and/or continuous scattering centers.

CERN Document Server

FastSLAM is a framework for simultaneous localization using a Rao-Blackwellized particle filter. In FastSLAM, particle filter is used for the mobile robot pose (position and orientation) estimation, and an Extended Kalman Filter (EKF) is used for the feature location's estimation. However, FastSLAM degenerates over time. This degeneracy is due to the fact that a particle set estimating the pose of the robot loses its diversity. One of the main reasons for loosing particle diversity in FastSLAM is sample impoverishment. It occurs when likelihood lies in the tail of the proposal distribution. In this case, most of particle weights are insignificant. Another problem of FastSLAM relates to the design of an extended Kalman filter for landmark position's estimation. The performance of the EKF and the quality of the estimation depends heavily on correct a priori knowledge of the process and measurement noise covariance matrices (Q ...

International Nuclear Information System (INIS)

The error estimation for calculated quantities relies on nuclear data uncertainty information available in the basic nuclear data libraries such as the U.S. Evaluated Nuclear Data File (ENDF/B). The uncertainty files (covariance matrices) in the ENDF/B library are generally obtained from analysis of experimental data. In the resonance region, the computer code SAMMY is used for analyses of experimental data and generation of resonance parameters. In addition to resonance parameters evaluation, SAMMY also generates resonance parameter covariance matrices (RPCM). SAMMY uses the generalized least-squares formalism (Bayes' method) together with the resonance formalism (R-matrix theory) for analysis of experimental data. Two approaches are available for creation of resonance-parameter covariance data. (1) During the data-evaluation process, SAMMY generates both a set of resonance ...

British Library Electronic Table of Contents (United Kingdom)

Looking at kriging problems with huge numbers of estimation points and measurements, computational power and storage capacities often pose heavy limitations to the maximum manageable problem size. In the past, a list of FFT-based algorithms for matrix operations have been developed. They allow extremely fast convolution, superposition and inversion of covariance matrices under certain conditions. If adequately used in kriging problems, these algorithms lead to drastic speedup and reductions in storage requirements without changing the kriging estimator. However, they require second-order stationary covariance functions, estimation on regular grids, and the measurements must also form a regular grid. In this study, we show how to alleviate these rather heavy and many times unrealistic restr...

International Nuclear Information System (INIS)

The author have prepared a new, fusion-oriented library of multigroup neutron cross sections, scattering matrices, and covariances (uncertainties and correlations). The 74-group library, called COVFILS-2, has been used, or will be used, by neutronics groups at Los Alamos National Lab. (LANL) at the University of California at Los Angeles, and at the Swiss Federal Institute for Reactor Research in the sensitivity and uncertainty analysis of fusion-relevant integral experiments such as the Li_2O experiment performed at the Fast Neutron Source Facility in Japan and the Lithium breeding module experiment planned at the LOTUS facility in Lausanne, Switzerland. Another intended use of this library is in the estimation of the uncertainty in key performance parameters (such as the breeding ratio) of conceptual fusion reactors. The 14 materials included in the first version of COVFILS-2 are hydrogen, "6Li, "7Li, beryllium, carbon, nitrogen, oxygen, ...

CERN Document Server

We consider a multiple-input multiple-output (MIMO) multiple access channel (MAC), where the channel between each transmitter and the receiver is modeled by the doubly-scattering channel model. Based on novel techniques from random matrix theory, we derive deterministic approximations of the mutual information, the signal-to-noise-plus-interference-ratio (SINR) at the output of the minimum-mean-square-error (MMSE) detector and the sum-rate with MMSE detection which are almost surely tight in the large system limit. Moreover, we derive the asymptotically optimal transmit covariance matrices. Our simulation results show that the asymptotic analysis provides very close approximations for realistic system dimensions.

CERN Document Server

A method for simulating power law noise in clocks and oscillators is presented based on modification of the spectrum of white phase noise, then Fourier transforming to the time domain. Symmetric real matrices are introduced whose traces--the sums of their eigenvalues--are equal to the Allan variances, in overlapping or non-overlapping forms, as well as for the corresponding forms of the modified Allan variance. Diagonalization of these matrices leads to expressions for the probability distributions for observing a variance at an arbitrary value of the sampling or averaging interval $\\tau$, and hence for estimating confidence in the measurements. A number of applications are presented for the common power-law noises.

Science.gov (United States)

... Following the application of the error covariance update equation, we apply the following operation to the parameter covariance matrix P+: ...

Energy Technology Data Exchange (ETDEWEB)

The procedure followed by the Laboratorio de Metrologia Nuclear in Sao Paulo, Brazil, for the standardization of {sup 242g} Am is described. The calibration system was composed of a 4 {pi} gas-flow proportional counter coupled to a pair of NaI(Tl) crystals operating in coincidence. The samples were produced by irradiating dried aliquots of {sup 241} Am with thermal and epithermal neutrons at the IEA-R1 research reactor. The efficiency tracer technique has been applied using {sup 60} Co as tracer. The beta detection efficiency was changed by external absorbers and extrapolated to unity by linear least square fitting applying covariance methodology. (author)

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared

Science.gov (United States)

of the determinant of the parameter covariance matrix for each ... parameter covariance matrix, as obtained from the Markov chains. The basic set ...

Energy Technology Data Exchange (ETDEWEB)

Cement-based composites are widely used in applications which demand long-term service life. One important example is in immobilization matrices for low-level radioactive and other hazardous wastes, which demands long-term retention and durability. The authors describe conductivity measurements of grouts flooded with water and in contact with a sink that consists of pure water. The conductivity measurements were designed and carried out in parallel with present quality verification methods and standard leach tests of the nuclear waste management industry. For the first time, the authors show that the method of replacing intrusive chemical analysis with conductivity measurements of the leaching samples yields equivalent results.

KoreaScience (Korea)

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British Library Electronic Table of Contents (United Kingdom)

Samples of two seawater farmed fish (crimson snapper (Lutjanus erythopterus) and snubnose pompano (Trachinotus blochii)), water, air, sediment, fish feed, macroalgae and phytoplankton were collected from two estuarine bays (Daya Bay and Hailing Bay) in South China. The concentrations of persistent halogenated compounds (PHCs) including polybrominated diphenyl ethers (PBDEs), organochlorine pesticides and polychlorinated biphenyls (PCBs) varied widely with the different sample matrices under investigation. The compositional patterns in fish, fish feed, macroalgae and phytoplankton, as well as the good correlations between the abundances of p,pprime-DDT and BDE-209 and their metabolites (i.e., p,pprime-DDD and p,pprime-DDE for p,pprime-DDT and BDE-47 for BDE-209) in fish indicated the occurr...

Energy Technology Data Exchange (ETDEWEB)

Coal bed natural gas (CBNG) development in the Powder River (PR) Basin produces modestly saline, highly sodic wastewater. This study assessed impacts of wetting four textural groups (0-11%, 12-22%, 23 -33%, and > 33% clay (g clay/100 g soil) x 100%))with simulated PR or CBNG water on water retention. Soils received the following treatments with each water quality: a single wetting event, five wetting and drying events, or five wetting and drying events followed by leaching with salt-free water. Treated samples were then resaturated with the final treatment water and equilibrated to -10, -33, -100, -500, or -1,500 kPa. At all potentials, soil water retention increased significantly with increasing clay content. Drought-prone soils lost water-holding capacity between saturation and field capacity with repeated wetting and drying, whereas finer textured soils withstood this treatment better and had increased water-retention capacity at lower ...

International Nuclear Information System (INIS)

Synthesis, morphology, structural and optical characteristics of SiC NWs and SiC/C nanocomposites with an inverse opal lattice have been investigated. The samples were prepared by carbothermal reduction of silica (SiC NWs) and by thermo-chemical treatment of opal matrices (SiC/C) filled with carbon compounds which was followed by silicon dioxide dissolution. It was shown that the nucleation of SiC NWs occurs at the surface of carbon fibers felt. It was observed three preferred growth direction of the NWs: [111], [110] and [112]. HRTEM studies revealed the mechanism of the wires growth direction change. SiC/C- HRTEM revealed in the structure of the composites, except for silicon carbide, graphite and amorphous carbon, spherical carbon particles containing concentric graphite shells (onion-like particles).

Science.gov (United States)

Selenium 79 is a beta emitter produced from (235)U fission and is one of the long half-life radionuclides of interest in nuclear waste disposal problematic because of its potential migration capacity to the surface environment. Measurement of (79)Se is particularly difficult due to its low activity in waste matrices (about 10(-3)Bqg(-1)). A radiochemical procedure based on ion exchange separations was already described in a previous paper. This work presents different applications of the radiochemical separation to waste samples and an improvement of this procedure, including a selective extraction of selenium as diethylselenium in an organic solvent followed by a re-extraction in aqueous medium. This additional step allows the decontamination factor to be increased with the aim of counting (79)Se by liquid scintillation counting. PMID:19071740

Science.gov (United States)

If we decompose C1 using SVD the parameter covariance matrix can be inverted to ... However, we can analyze the parameter covariance matrix directly by ...

Science.gov (United States)

The estimated parameter covariance matrix is computed from8. ) ( ) 1. 2. T. T. ( ) ( )(. ?. ?. ?. Cov. E. ??. . ?. = . ? ? ? ? ?. ?. = ?. ?. ? ...

International Nuclear Information System (INIS)

The author presents his views on the interrelation of quantum theory, space-time, Lorentz covariance and tachyons. He makes general observations on the nature of these topics and in particular on the nature of the mathematics used for their description and, without reaching any definite conclusions, points out some areas which require further critical examination. (W.D.L.).

Energy Technology Data Exchange (ETDEWEB)

A total of forty participants were included in the exercise, including NOAA, USEPA, state, Australian, Canadian, Mexican and Argentinean laboratories. Two samples were sent by NRC to each participant: a contaminated marine sediment from the vicinity of New York Bay and a freeze dried mussel (Mytilus edulis) from Charlottenlund, Denmark. Laboratories were also asked to analyze two certified reference materials NIST SRM 1566a, and NRC BCSS-1. The elements to be determined were Al, Cr, Fe, Ni, Cu, Zn, As, Se, Ag, Cd, Sn, Hg, and Pb for both matrices, plus Be, Si, Mn, Sb, and Tl for the sediments. An accepted mean and confidence interval were calculated for each analyte in the two unknown samples. Laboratory biases were identified and an overall rating of superior, good, fair or others was assigned to each laboratory.

International Nuclear Information System (INIS)

In 1980 the multilevel multichannel R-matrix code SAMMY was released for use in analysis of neutron data at the Oak Ridge Electron Linear Accelerator. Since that time, SAMMY has undergone significant modifications: (1) User-friendly options have been incorporated to streamline common operations and to protect a run from common user errors, (2) The Reich-Moore formalism has been extended to include an optional logarithmic parameterization of the external R-matrix, for which any or all parameters may be varied, (3) the ability to vary sample thickness, effective temperature, matching radius, and/or resolution-broadening parameters has been incorporated, (4) to avoid loss of information (i.e. computer round-off errors) between runs, the ''covariance file'' now includes precise values for al variables, (5) Unused but correlated variables may be included in the analysis. Because of these and earlier changes, the 1980 SAMMY manual is now hopelessly ...

CERN Document Server

We consider the alternating sign matrices of the odd order that have some kind of central symmetry. Namely, we deal with matrices invariant under the half-turn, quarter-turn and flips in both diagonals. In all these cases, there are two natural structures in the centre of the matrix. For example, for the matrices invariant under the half-turn the central element is equal $\\pm 1$. It was recently found that $A^+_{HT}(2m+1)/A^-_{HT}(2m+1)$=(m+1)/m. We conjecture that similar very simple relations are valid in the two remaining cases.

Energy Technology Data Exchange (ETDEWEB)

In order to obtain the resonance parameters in a single energy range and the corresponding covariance matrix, a reevaluation of 239Pu was performed with the code SAMMY. The most recent experimental data were analyzed or reanalyzed in the energy range thermal to 2.5 keV. The normalization of the fission cross section data was reconsidered by taking into account the most recent measurements of Weston et al. and Wagemans et al. A full resonance parameter covariance matrix was generated. The method used to obtain realistic uncertainties on the average cross section calculated by SAMMY or other processing codes was examined.

Science.gov (United States)

... [5] GT Gullberg, RH Huesman, DNG Roy, J. Qi and BW Reutter, Esti- mation of the parameter covariance matrix for a one-compartment cardiac ...

Science.gov (United States)

... these estimates were obtained from these and the parameter covariance matrix using a parametric bootstrap method. We present the ... ...

Energy Technology Data Exchange (ETDEWEB)

We suggest a procedure for estimating uncertainties in neutron cross sections calculated with a nuclear model descriptive of a specific mass region. It applies standard error propagation techniques, using a model-parameter covariance matrix. Generally, available codes do not generate covariance information in conjunction with their fitting algorithms. Therefore, we resort to estimating a relative covariance matrix a posteriori from a statistical examination of the scatter of elemental parameter values about the regional representation. We numerically demonstrate our method by considering an optical-statistical model analysis of a body of total and elastic scattering data for the light fission-fragment mass region. In this example, strong uncertainty correlations emerge and they conspire to reduce estimated errors to some 50% of those obtained from a naive uncorrelated summation in quadrature. 37 references.

British Library Electronic Table of Contents (United Kingdom)

Major forecast errors on the background error covariance from initial conditions, atmospheric forcing, model open boundary conditions, and the river discharges are examined in a coastal model of northern South China Sea. The analysis of background error covariance matrix produced by model ensemble shows that the perturbations of the initial conditions and atmospheric forcing play major roles in producing and maintaining the amplitude of ensemble spread except for the sea surface height (SSH) field. The perturbation of model open boundary conditions can influence ensemble spread of all variables and covariance between temperature and velocity or between temperature and SSH. The perturbation of river discharge mainly affects the covariance of salinity in river estuary. A data assimilation ex...

International Nuclear Information System (INIS)

Volatile compounds produced in flexible food packaging materials (LDPE, EVAc, PET/PE/EVOH/PE) during electron beam irradiation were isolated by purge and trap technique and identified by combined gas chromatography-mass spectrometry (GC/MS), after thermal desorption and concentration. For comparison purposes non-irradiated films were also studied. Film samples were irradiated at low (5 kGy, corresponding to cold pasteurization), intermediate (20 kGy, corresponding to cold sterilization) and high (100 kGy) doses. It was observed that a number of volatile compounds are produced after irradiation in all cases. Furthermore the amounts of all volatile compounds increase with increasing irradiation dose. Both primary (methyl-derivatives etc.) as well as secondary i.e. oxidation products (ketones, aldehydes, alcohols, carboxylic acids etc.) are produced upon irradiation. These products may affect organoleptic properties and thus shelf-life of prepackaged irradiated foods. ...

Science.gov (United States)

The experimental work completed thus far in the areas of rapid radiochemical separations and metastable isomeric states is summarized. Activation analyses were made in samples of ore materials and metals using rapid radiochemical separations to isolate short-lived radioactive isotopes such as 3.77-min V/sup 52/ and 14.6-min Mo/sup 101/. The analytical results obtained were compared to the results obtained from standard chemical and instrumental analytical methods and, where possible, to activation analysis results obtained from longer-lived isotopes of the same element. Further work is in progress to improve the procedures, to evaluate the reproducibility and accuracy of the methods, and to evaluate their usefulness on a wide variety of sample matrices. The research on short-lived metastable isomers showed that 1.7-min W/sup 185m/ is not produced in sufficiently high yield for the development of a ...

CERN Document Server

In this paper we classify a linear family of Lie brackets on the space of rectangular matrices $Mat(n\\times m,\\K)$ and we give an analogue of the Ado's Theorem. We give also a similar classification on the algebra of the square matrices $Mat(n, \\K)$ and as a consequence, we prove that we can't built a faithful representation of the $(2n+1)$-dimensional Heisenberg Lie algebra $\\mathfrak{H}_n$ in a vector space $V$ with $\\dim V\\leq n+1$. Finally, we prove that in the case of the algebra of square matrices $Mat(n,\\K)$, the corresponding Lie algebras structures are a contraction of the canonical Lie algebra $\\mathfrak{gl}(n,\\K)$.

International Nuclear Information System (INIS)

Developed under the PN II Project 71-009 - MONA, the pre-operational monitoring program of the LIL waste disposal site presented in this paper covers the main elements requested for a continuous improvement of site characterization and safety assessment, as well as for the set up of the baseline data requested for the future operational and post-operational monitoring and surveillance. These elements are: vadose and saturated zones hydrogeology, surface erosion, meteorology and radionuclides content in waters, soil and biota. Pairs of TDR (Time Domain Reflectometry) and pressure sensors, coupled with a meteorological station have been installed on site for the continuously measurement of the water content and matric potential changes due to the climate variations. The data will be used to follow the water balance, the pores water velocity and to calculate the infiltration rate. A new set of erosion rates experimentally determined by Pinhole test on surface soil ...

International Nuclear Information System (INIS)

Laser-Induced Breakdown Spectroscopy was selected by NASA as part of the ChemCam instrument package for the Mars Science Laboratory rover to be launched in 2009. ChemCam's Laser-Induced Breakdown Spectroscopy instrument will ablate surface coatings from materials and measure the elemental composition of underlying rocks and soils at distances from 1 up to 10 m. The purpose of our studies is to develop an analytical methodology enabling identification and quantitative analysis of these geological materials in the context of the ChemCam's Laser-Induced Breakdown Spectroscopy instrument performance. The study presented here focuses on several terrestrial rock samples which were analyzed by Laser-Induced Breakdown Spectroscopy at an intermediate stand-off distance (3 m) and in an atmosphere similar to the Martian one (9 mbar CO2). The experimental results highlight the matrix effects and the measurement inaccuracies due to the noise accumulated when low signals are ...

CERN Document Server

In these lecture notes we present some connections between random matrices, the asymmetric exclusion process, random tilings. These three apparently unrelated objects have (sometimes) a similar mathematical structure, an interlacing structure, and the correlation functions are given in terms of a kernel. In the basic examples, the kernel is expressed in terms of orthogonal polynomials.

International Nuclear Information System (INIS)

Given the local observables in the vacuum sector fulfilling a few basic principles of local quantum theory, we show that the superselection structure, intrinsically determined a priori, can always be described by a unique compact global gauge group acting on a field algebra generated by field operators which commute or anticommute at spacelike separations. The field algebra and the gauge group are constructed simultaneously from the local observables. There will be sectors obeying parastatistics, and intrinsic notion derived from the observables, if and only if the gauge group is non-Abelian. Topological charges would manifest themselves in field operators associated with spacelike cones but not localizable in bounded regions of Minkowski space. No assumption on the particle spectrum or even on the covariance of the theory is made. However the notion of superselection sector is tailored to theories without massless particles. When translation or Poincare ...

UK PubMed Central (United Kingdom)

The epigenome consists of non–sequence-based modifications, such as DNA methylation, that are heritable during cell division and that may affect normal phenotypes and predisposition...Full Text Available

Science.gov (United States)

... 975 (6.02) 2009 (12.40) 456 (2.81) 1628 (10.05) 799 (4.93) 598 (3.07) ... 1. The covariates listed in this table were those used in the FDA PS estimation model. ...

International Nuclear Information System (INIS)

We analyse the relation between the exchange algebra and the separation of the chiralities in classical Toda field theory. We show that there exists a conformally covariant Bloch wave basis such that the two chiralities commute. In terms of this basis we then reconstruct the periodic and local solution of Toda field theory. (orig.).

Energy Technology Data Exchange (ETDEWEB)

We evaluate the sphere level S-matrix element of two tachyons and two massless NS states, the S-matrix element of four tachyons, and the S-matrix element of two tachyons and two Ramond-Ramond vertex operators, in type 0 theory. We then find an expansion for theses amplitudes that their leading order terms correspond to a covariant tachyon action. To the order considered, there are no T4, T2(-bar T)2, T2H2, nor T2R tachyon couplings, whereas, the tachyon couplings FF-bar T and T2F2 are non-zero.

Energy Technology Data Exchange (ETDEWEB)

The proposed aim of the work is to verify the effects produced on different kinds of environmental pollutants after exposure to a low frequency radiation such as microwaves. They have proved capable of producing minimum heating of the matrix as well as modifications in the structure of the molecules at the level of simple bonds. Steps were also taken ti check whether the degradation action of the microwaves could be boosted by sunlight. For this reason tests were run also on samples irradiated using microwaves and a lamp capable of simulating the sun's spectrum, as well as in the presence of a single lamp. [Italian] Lo scopo di questa ricerca e' di verificare gli effetti prodotti su inquinanti ambientali, di diversa natura, a seguito di un'esposizione ad una radiazione a bassa frequenza come le microonde. Le microonde possono produrre minimi riscladamenti della matrice e modificazioni della struttura delle molecole, a ...

Science.gov (United States)

The principles of modern pesticide residue chemistry were articulated in the 1950s. Early authors pointed out the advantages of systematizing and standardizing analytical methods for pesticides so that they could be widely practiced and the results could be reproduced from one laboratory to the next. The availability of improved methods has led to a much more complete understanding of pesticide behavior and fate in foods and the environment. Using methods based largely upon gas chromatography (GC) and high-performance liquid chromatography (HPLC) coupled increasingly with mass spectrometry (MS) and MS(n) as the detection tool, residues can be measured at parts per billion levels and below in a variety of food and environmental matrices. Development of efficient extraction and cleanup methods, techniques such as ELISA, efficient sample preparation techniques such as QuEChERS, and automated laboratory and field instrumentation has also ...

International Nuclear Information System (INIS)

Ultraveiolet spectroscopy of molecules in vapour phase gives valuable information about electronic structure of free molecules. But in many cases vaipour phase investigations are not possible and in order to isolate molecules within solid lattice, we used cryogenic temperature and high vacuum technology to study absorption spectrum within the spectral range (230-270)nm of an isolated benzene molecule in Argon, Krpton, Nitrogen, Carbon and methane matrices. The spectra shifts were measured and calculated in the matrix environment for the electronnic transition (B 24--A 19) in benzene molecule using the matrices mentioned above. Molar extinction coefficients and oscillator strength were measured too. (7 tabs., 32 figs., 50 refs.).

Science.gov (United States)

Pedel. 24.8. 0. 0. 38.0. 21.7. 35. Page 38. TABLE VII.- PREFILTER AND FEEDBACK GAIN MATRICES G AND F. FOR DECOUPLED LATERAL AND LONGITUDINAL CONTROLS ...

Energy Technology Data Exchange (ETDEWEB)

A novel direct calculation method of response matrices on heterogeneous lattices by using the Monte Carlo method is proposed. These direct response matrices (DRMs) can be used in core calculations in place of the conventional homogenized lattice constants. The DRMs are formalized by four sub response matrices (sub-RMs) in order to respond to a core eigenvalue, k; thus the DRMs can be re-evaluated on each outer iteration in the core calculations. The sub-RMs can be evaluated by analyzing each neutron's trajectory from ordinary lattice calculations with the Monte Carlo code. Since these sub-RMs are calculated directly under an actual complex assembly geometry, i,e., without a homogenization process, intra-assembly heterogeneous effects can be reflected on global partial current balance calculations. With using two of the sub-RMs, which deal with neutron production probabilities for each fuel pin, and the obtained ...

CERN Document Server

By using a model independent Monte Carlo approach, we study the possible structure of charged and neutral lepton mass matrices, under the assumption of an U(2) horizontal symmetry (additional to the usual Standard Model ones) involving the light fermion generations. We assume the most general Majorana mass matrix for neutrinos. We update the results of our previous similar study, by inserting in the analysis the recent KamLAND data, that contributed to find a final solution to the Solar neutrino problem. The introduction of the new experimental data reduce the allowed regions in the nine dimensional space parameters, and show that our procedure gives stable solutions.

International Nuclear Information System (INIS)

A methods is presented for an accurate numerical determination of eigenvalues of real symmetric para-p diagonal matrices. The method takes advantage of the band structure to break up the matrix into p x p blocks and performing algebraic operations including inversions on these blocks only, no matter what the size of the matrix is. The eigenvalues are determined independently one at a time. Thus any error in the determination of one eigenvalue does not affect the other eigenvalues. The method is ideally suited for the Schroedinger eigenvalue problem of the anharmonic potentials. (author).

CERN Document Server

This thesis consists of three parts. In the first part we review the quantization of Yang-Mills theories and perturbative quantum gravity in curved spacetime. In the second part we calculate the Feynman propagators of the Faddeev-Popov ghosts for Yang-Mills theories and perturbative quantum gravity in the covariant gauge. In the third part we investigate the physical equivalence of covariant Wightman graviton two-point function with the physical graviton two-point function. The Feynman propagators of the Faddeev-Popov ghosts for Yang-Mills theories and perturbative quantum gravity in the covariant gauge are infrared (IR) divergent in de Sitter spacetime. We point out, that if we regularize these divergences by introducing a finite mass and take the zero mass limit at the end, then the modes responsible for these divergences will not contribute to loop diagrams in computations of time-ordered products in either Yang-Mills ...

International Nuclear Information System (INIS)

This work concerns the development of a methodology the objective of which is to characterize and diagnose two-phase flow regime transitions. The approach is based on the fundamental assumption that a transition flow is less stationary than a flow with an established regime. During the first time, the efforts focused on: (1) the design and construction of an experimental loop, allowing to reproduce the main horizontal two-phase flow patterns, in a stable and controlled way; (2) the design and construction of an electrical impedance probe, providing an imaged information of the spatial phase distribution in the pipe; and (3) the systematic study of the joint time-frequency and time-scale analysis methods, which permitted to define an adequate parameter quantifying the unstationarity degree. During the second time, in order to verify the fundamental assumption, a series of experiments were conducted, the objective of which was to demonstrate the correlation between unstationarity and ...

CERN Document Server

The point-splitting regularization technique for composite operators is discussed in connection with anomaly calculation. We present a pedagogical and self-contained review of the topic with an emphasis on the technical details. We also develop simple algebraic tools to handle the path ordered exponential insertions used within the covariant and non-covariant version of the point-splitting method. The method is then applied to the calculation of the chiral, vector, trace, translation and Lorentz anomalies within diverse versions of the point-splitting regularization and a connection between the results is described. As an alternative to the standard approach we use the idea of deformed point-split transformation and corresponding Ward-Takahashi identities rather than an application of the equation of motion, which seems to save the complexity of the calculations.

International Nuclear Information System (INIS)

We investigate the q-deformation of the BRST algebra, the algebra of the ghost, matter and gauge fields on one spacetime point using the result of the bicovariant differential calculus. There are two nilpotent operations in the algebra, the BRST transformation #delta#_B and the derivative d. We show that one can define the covariant commutation relations among the fields and their derivatives consistently with these two operations as well as the *-operation, the antimultiplicative inner involution. (orig.).

Energy Technology Data Exchange (ETDEWEB)

The t<0 branch of pre-big bang cosmological scenarios is subject to a gravitational wave instability. The unstable behaviour of tensor perturbations is derived in a very simple way in Hwang's covariant and gauge-invariant formalism developed for extended theories of gravity. A simple interpretation of this instability as the effect of an ''antifriction'' is given, and it is argued that a universe must eventually enter the expanding phase. (orig.)

CERN Document Server

We argue that the occurrence of late-time acceleration can conveniently be described by first-order general relativity covariantly coupled to fermions. Dark energy arises as a gravitationally driven BCS condensate of fermions which forms in the early universe. At late times, the gap and chemical potential evolve to have an equation of state with effective negative pressure, thus naturally leading to acceleration.

International Nuclear Information System (INIS)

Immunoassays are versatile analytical techniques that had a leading role in various clinical applications, during the last four decades. The studies carried out by Rosalyn Yalow, Solomon Berson and Roger Ekins in the 1960s gave a breakthrough in the development of this novel analytical method. Sensitivity up to femtomolar concentrations, high specificity and universal application to different classes of molecular species made immunoassay a very useful tool in analytical investigation. The expertise acquired by immunochemists in producing antibodies against any antigen and the ability of radiochemists in labeling the antigens with "1"2"5I without affecting the active site are the two main factors responsible for the above development. There are concerns about the safety and health of humans due to the high-level contamination of environment by pesticides, industrial compounds and metals, anabolic steroids in milk and meat products, and presence of mycotoxins in food and feed ...

CERN Document Server

Hidden Markov models (HMMs) are probabilistic functions of finite Markov chains, or, put in other words, state space models with finite state space. In this paper we examine subspace estimation methods for HMMs whose output lies a finite set as well. In particular we study the geometric structure arising from the non-minimality of the linear state space representation of HMMs, and consistency of a subspace algorithm arising from a certain factorisation of the singular value decomposition of the estimated linear prediction matrix. For this algorithm we show that the estimates of the transition and emission probability matrices are consistent up to a similarity transformation, and that the m-step linear predictor computed from the estimated system matrices is consistent, i.e. converges to the true optimal linear m-step predictor.

British Library Electronic Table of Contents (United Kingdom)

Scuffing damage is catastrophic and typically not self-healing. It severely affects the life and reliability of engineering components, such as cams, roller bearings, piston rings, cylinder bores and gears. Gray iron and 1080 steel are important materials for these extremely demanding structural components. There have been several scuffing studies done in the past with various types of steel and cast iron. However, in these studies there was no attempt to compare the scuffing resistance of cast iron and steel materials with similar matrices. In the present study, scuffing tests were performed with the matrices of gray iron and 1080 steel being fully pearlitic. This allows for a direct evaluation of the effect of the graphite flakes on scuffing resistance. The scuffing behavior for these ma...

British Library Electronic Table of Contents (United Kingdom)

An improved singular value decomposition method of gear fault identification based on Hilbert-Huang transform was proposed to overcome the problem of reconstructing a feature matrix of singular value decomposition. The method includes three steps. First, the instantaneous frequency and amplitude matrices were acquired by Hilbert-Huang transform from faulted gear signals. Second, after the matrices were decomposed by singular value decomposition, the defined distances of singular value vectors and the optimal threshold of the distance for classification were calculated. Third, the fault characteristics of a gearbox were identified and classified by the threshold of the distances. The result demonstrates that the proposed method effectively identifies the gear fault and can realize an automa...

CERN Document Server

We discuss first the flavor mixing of the quarks, using the texture zero mass matrices. Then we study a similar model for the mass matrices of the leptons. We are able to relate the mass eigenvalues of the charged leptons and of the neutrinos to the mixing angles and can predict the masses of the neutrinos. We find a normal hierarchy - the masses are 0.004 eV, 0.01 eV and 0.05 eV. The atmospheric mixing angle is given by the mass ratios of the charged leptons and the neutrinos. we find about 40 degrees, consistent with the experiments. The mixing element, connecting the first neutrino wit the electron, is predicted to be 0.05. This prediction can soon be checked by the Daya Bay experiment.

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.

Science.gov (United States)

... matrices were written in the form R(t) = R'(t) Mpp T V(t) = V (t) MppT (C-3) 49 Page 59. ... GW~/EE/64.-9 where ra(!L) rb(L) 0 MPPT= (C-4) [rb(L) ra(L) 0 ...

Energy Technology Data Exchange (ETDEWEB)

Tetracycline in solution of benzyl alcohol was used as an extracting agent to separate uranium from interfering elements in the determination of uranium and of isotopic ratio sup(235)U/sup(238)U by neutron activation analysis. Separation gives a recovery of 97% for uranium and the interferences from matrices of pitchblende and monazite are eliminated.

International Nuclear Information System (INIS)

1 - Description of program or function: This program solves an eigenvalue problem zBx=Ax where A and B are real block tri-diagonal matrices. This eigenvalue problem is derived from a reduced set of linear resistive MHD equations which is often employed to study tokamak plasma stability problem. 2 - Method of solution: Both the determinant and inverse iteration methods are employed. 3 - Restrictions on the complexity of the problem: The eigenvalue z must be real

International Nuclear Information System (INIS)

The report describes the studies carried out to design a non-destructive system for the radiological characterization of packages containing LLW and MLW. This technique is applied for quantitative and qualitative gamma emitters determination in packages with homogeneous and heterogeneous matrices as well as the development of a maximum activity points location system. Development involves also the automatization for its industrial use.

International Nuclear Information System (INIS)

The formalism of statistical mechanics of particles slower than light has been considered from the point of view of the application of this formalism for the description of tachyons. Properties of ideal gases of tachyons have been discussed in detail. After finding general formulae for quantum, Bose and Fermi gases the classical limit has been considered. It has been shown that Bose-Einstein condensation occurs. The tachyon gas of bosons violates the third principle of thermodynamics. Degenerated Fermi gas has been considered and in this case the entropy vanishes at zero temperature. Difficulties of formulating covariant statistical mechanics have been discussed.

International Nuclear Information System (INIS)

We show using covariant techniques that the Einstein static universe containing a perfect fluid is always neutrally stable against small inhomogeneous vector and tensor perturbations and neutrally stable against adiabatic scalar density inhomogeneities so long as c"2_s > 1/5, and unstable otherwise. We also show that the stability is not significantly changed by the presence of a self-interacting scalar field source, but we find that spatially homogeneous Bianchi type IX modes destabilize an Einstein static universe. The implications of these results for the initial state of the universe and its pre-inflationary evolution are also discussed. (letter to the editor)

British Library Electronic Table of Contents (United Kingdom)

The cubature Kalman filter (CKF) is a relatively new addition to derivative-free approximate Bayesian filters built under the Gaussian assumption. This paper extends the CKF theory to address nonlinear smoothing problems; the resulting state estimator is named the fixed-interval cubature Kalman smoother (FI-CKS). Moreover, the FI-CKS is reformulated to propagate the square-root error covariances. Although algebraically equivalent to the FI-CKS, the square-root variant ensures reliable implementation when committed to embedded systems with fixed precision or when the inference problem itself is ill-conditioned. Finally, to validate the formulation, the square-root FI-CKS is applied to track a ballistic target on reentry.

Science.gov (United States)

Context: The Balanced Budget Act (BBA) of 1997 allowed some rural hospitals meeting certain requirements to convert to Critical Access Hospitals (CAHs) and changed their Medicare reimbursement from prospective to cost-based. Some subsequent CAH-related laws reduced restrictions and increased payments, and the number of CAHs grew rapidly. Purpose: To examine factors related to hospitals' decisions to convert and time to CAH conversion. Methods: Eighty-nine rural hospitals in Iowa were characterized and observed from 1998 to 2005. Cox proportional hazards models were used to identify the determinants of time to CAH conversion. Findings: T-test and one-covariate Cox regression indicated that, in 1998, Iowa rural hospitals with more staffed beds, discharges, and acute inpatient days, higher operating margin, lower skilled swing bed days relative to acute days, and located in relatively high density counties were more likely to convert later or not convert before 2006. ...

Science.gov (United States)

Two hazard risk assessment matrices for the ranking of occupational health risks are described. The qualitative matrix uses qualitative measures of probability and consequence to determine risk assessment codes for hazard-disease combinations. A walk-through survey of an underground metalliferous mine and concentrator is used to demonstrate how the qualitative matrix can be applied to determine priorities for the control of occupational health hazards. The semi-quantitative matrix uses attributable risk as a quantitative measure of probability and uses qualitative measures of consequence. A practical application of this matrix is the determination of occupational health priorities using existing epidemiological studies. Calculated attributable risks from epidemiological studies of hazard-disease combinations in mining and minerals processing are used as examples. These historic response data do not reflect the risks associated with current exposures. A method using ...

Energy Technology Data Exchange (ETDEWEB)

The present study discusses the contribution of the adoption of more rigorous and objective criteria to the selection and analysis of information sources, leading to more scientific rigour when registering phytotherapic drugs. To this end, it is herein proposed the adoption of a previously tested and acknowledged methodology, namely the Systematic Revision, as a standard for phytotherapic drug analyses. In order to show differences brought about by the Systematic Revision during the registration procedures of phytotherapic drugs, the case of the Maytenus ilicifolia (known popularly in Brazil as 'espinheira-santa') is presented. As it is well known, the use of ionizing radiation is expanding, especially in medicine and pharmacy. Therefore, gamma radiation was applied to the microbiological quality control of phytotherapic matrices. Results indicated a positive contribution of Systematic Revision to the registration procedures of phytotherapic ...

Science.gov (United States)

The phase space beam analyzer is a measurement instrument that is applied in laser technology to perform analyses of the spatial and angular distribution of rays. We are interested in this instrument as a means to characterize non-coherent light sources. In this context, a closer look at the tolerances of this optical instrument was considered useful. Having a so-called quadrupole lens as a key element, the phase space beam analyzer is a device that features anamorphic optical properties. To describe these anamorphic properties, recurrence was made to a description by extended ray-transfer matrices. This formalism allows for an analysis of the alignment tolerances of the phase space beam analyzer and facilitates a study of the sensitivities of the instrument. The analysis is complemented using numerical ray tracing.

International Nuclear Information System (INIS)

Topological Chern-Simons theory coupled to matter fields is analysed in the framework of Dirac's method of quantising constrained systems in a general class of linear, non-local gauges. We show that in the weak coupling limit gauge invariant operators in the theory transform under an exchange according to a higher dimensional representation of the braid group which is built out of the fundamental representation matrices of the gauge group and thus behave like anyons. We also discover new solutions of the Yang-Baxter equation which emerges as a consistency condition on the structure functions of the operator algebra of the matter fields. (orig.).

British Library Electronic Table of Contents (United Kingdom)

Purpose - This paper aims to describe the technology and applications of nanocomposite materials. Design/methodology/approach - This paper discusses products, applications and technological developments in polymer, ceramic and metal nanocomposites. It concludes with a brief consideration of electronic component applications. Findings - It is shown that polymer nanocomposites and the materials used in their production are commercially available and finding applications in several industries, including automotive, military, food, electronics and leisure, due to their enhanced mechanical, electrical and thermal properties. Ceramic and metallic nanocomposites are at an earlier stage of development and a critical issue to resolve is optimising the dispersion of nanomaterials in the matrices. Pa...

International Nuclear Information System (INIS)

Energy conservation and local energy deposition are investigated in the context of coupled-particle (i.e., neutrons, gamma rays, and charged particles) transport analysis. For charged particles, the concept of group splitting the 1 = 0 transfer matrix to ensure both particle and energy conservation is introduced. Although these procedures are more complex than those found in the usual neutron or coupled-neutron gamma-ray problem, they yield a consistent approach for the calculation of local energy deposition.

British Library Electronic Table of Contents (United Kingdom)

A classical linear group GJ between the graded ring S= d=0^~Sd, where Sd is the character group of the symmetric group Sd, and the inverse limit J with respect to n of rings of symmetric polynomials in n variables. As a consequence, we complete the description of relations between generators for O(n)-invariants as well as the description of relations for invariants of mixed representations of quivers. We also obtain an independent proof of the result that the ideal of free relations for GL(n)-invariants is zero, which was proved by Donkin in [S. Donkin, Invariant functions on matrices, Math. Proc. Cambridge Philos. Soc. 113 (1993) 23-43].

Energy Technology Data Exchange (ETDEWEB)

In this work the development of a third order scheme of finite differences centered in mesh is presented and it is applied in the numerical solution of those diffusion equations in multi groups in stationary state and X Y geometry. Originally this scheme was developed by Hennart and del Valle for the monoenergetic diffusion equation with a well-known source and they show that the one scheme is of third order when comparing the numerical solution with the analytical solution of a model problem using several mesh refinements and boundary conditions. The scheme by them developed it also introduces the application of numeric quadratures to evaluate the rigidity matrices and of mass that its appear when making use of the finite elements method of Galerkin. One of the used quadratures is the open quadrature of 4 points, no-standard, of Newton-Cotes to evaluate in approximate form the elements of the rigidity matrices. The other quadrature is that of ...

CERN Document Server

In Aldous and Shields (1988), a model for a rooted, growing random binary tree was presented. For some c>0, an external vertex splits at rate c^(-i) (and becomes internal) if its distance from the root (depth) is i. For c>1, we reanalyse the tree profile, i.e. the numbers of external vertices in depth i=1,2,.... Our main result are concrete formulas for the expectation and covariance-structure of the profile. In addition, we present the application of the model to cellular ageing. Here, we assume that nodes in depth h+1 are senescent, i.e. do not split. We obtain a limit result for the proportion of non-senescent vertices for large h.

International Nuclear Information System (INIS)

The Lorentz and coordinate covariant calculus of spinors in Riemannian spacetime, which is the mathematical model for the description of the quantum mechanics of elementary particles with spin interacting with the classical gravitation field, is explored. The Dirac equation describing the interaction of neutrinos with the gravitational fields of the Robertson-Walker cosmological world models is separated, and the spectrum of eigenfunctions and eigenvalues for particular choices of the set of quantum numbers is given explicitly for the k = 0 and k = +1 models, although only the radial equations determining the final quantum number are given for the k = -1 model. The mathematical theory of the motion of a perfect fluid whose elements interact via long-range neutrino-exchange forces, as well as gravitationally, is developed. The formalism for calculating, by calculating the Bogoliubov transformation of the Fock space operators that instantaneously diagonalize their ...

British Library Electronic Table of Contents (United Kingdom)

Abstract: Most cities are actually very concerned about the economic viability of waste management and also about the impact they may have on the environment. Economical, social and cultural factors in the population will determine the characteristics in waste and the value of the design parameters used in the calculations of a collection system. A clear understanding of these factors is fundamental to plan and to implement efficient and sustainable collecting strategies. Our goal in this work is to model municipal waste separation rates in Spanish cities with over 50,000 inhabitants taking their different socio-economic, demographic and logistic covariates into account. Several statistical regression models to manage continuous proportion data are compared, these being: Generalized linear...

CERN Document Server

Bargmann's superselection rule, which forbids the existence of superpositions of states with different mass and, therefore, implies the impossibility of describing unstable particles in non-relativistic quantum mechanics, arises as a consequence of demanding Galilean covariance of Schr\\"odinger's equation. However, the usual Galilean transformations inadequately describe the symmetries of non-relativistic quantum mechanics since they fail to take into account relativistic time contraction effects which can produce non-relativistic phases in the wavefunction. In this paper we describe the incompatibility between Bargmann's rule and Lorentz transformations in the low-velocities limit, we analyze its classical origin and we show that the Extended Galilei group characterizes better the symmetries of the theory. Furthermore, we claim that a proper description of non-relativistic quantum mechanics requires a modification of the notion of spacetime in the corresponding ...

CERN Document Server

In Randall-Sundrum-type brane-world cosmologies, the dynamical equations on the three-brane differ from the general relativity equations by terms that carry the effects of imbedding and of the free gravitational field in the five-dimensional bulk. Instead of starting from an ansatz for the metric, we derive the covariant nonlinear dynamical equations for the gravitational and matter fields on the brane. The local energy-momentum corrections are significant only at very high energies, and in this regime we show that fluid world-lines have a non-gravitational acceleration off the brane. The imprint on the brane of the nonlocal gravitational field in the bulk is more subtle, and we provide a careful decomposition of this effect. The nonlocal energy density determines the tidal acceleration in the off-brane direction, and can oppose singularity formation via the generalized Raychaudhuri equation. Unlike the nonlocal energy density and flux, the nonlocal anisotropic ...

British Library Electronic Table of Contents (United Kingdom)

In this study, we examined the relationship between trait-like communication apprehension (CA) and resting alpha range asymmetry in the anterior cortex (AC). Although theory and research in cognitive neuroscience suggest that asymmetry in the AC constitutes a relatively stable, inborn, substrate of emotion, some studies indicate that asymmetry can be increased by experimentally induced transitory anxiety. Transitory anxiety produced by interaction with strangers covaries with trait-like CA, raising questions regarding whether asymmetrical electrical activity in the AC during data collection represents resting levels as assumed in the literature or transitory reactions to dyadic interaction with the experimenter. Because the question if unanswered poses issues for theory and approaches to r...

International Nuclear Information System (INIS)

We present a new relativistic bound-state formalism for two interacting Fermi-Dirac particles. The kernel of the integral equation for the bound-state system is generated by summing Feynman scattering amplitudes and multiplying by a bound-state amplitude. The method is illustrated through calculations of the hyperfine and fine splittings of positronium up to order #alpha#"5. Our calculations of the one-loop contributions are carried out in the explicitly covariant Feynman gauge. We also present new results for the hyperfine and fine splittings in positronium to order #alpha#"5 for arbitrary principal quantum number n, which are easily obtained owing to the virtue of conceptual and calculational simplicity of our formalism. In addition, we present the one-loop renormalization scheme in our formalism. (author).

CERN Document Server

A fully consistent linear perturbation theory for cosmology is derived in the presence of quantum corrections as they are suggested by properties of inverse volume operators in loop quantum gravity. The underlying constraints present a consistent deformation of the classical system, which shows that the discreteness in loop quantum gravity can be implemented in effective equations without spoiling space-time covariance. Nevertheless, non-trivial quantum corrections do arise in the constraint algebra. Since correction terms must appear in tightly controlled forms to avoid anomalies, detailed insights for the correct implementation of constraint operators can be gained. The procedures of this article thus provide a clear link between fundamental quantum gravity and phenomenology.

CERN Document Server

This paper offers a conceptually straightforward method for the calculation of stresses in polarisable media based on the notion of a drive form and its property of being closed in spacetimes with symmetry. After an outline of the notation required to exploit the powerful exterior calculus of differential forms, a discussion of the relation between Killing isometries and conservation laws for smooth and distributional drive forms is given. Instantaneous forces on isolated spacetime domains and regions with interfaces are defined, based on manifestly covariant equations of motion. The remaining sections apply these notions to media that sustain electromagnetic stresses, with emphasis on homogeneous magnetoelectric material. An explicit calculation of the average pressure exerted by a monochromatic wave normally incident on a homogeneous, magnetoelectric slab in vacuo is presented and the concluding section summarizes how this pressure depends on the parameters in ...

CERN Document Server

We obtain an elegant and useful description of the dynamics of Szekeres dust models (in their full generality) by means of "quasi--local" scalar variables constructed by suitable integral distributions that can be interpreted as weighed proper volume averages of the local covariant scalars. In terms of these variables, the field equations and basic physical and geometric quantities are formally identical to their corresponding expressions in the spherically symmetric LTB dust models. Since we can map every Szekeres model to a unique LTB model, rigorous results valid for the latter models can be readily generalized to a non--spherical Szekeres geometry. The new variables lead naturally to an initial value formulation in which all scalars are expressed as scaling laws in terms of their values at an arbitrary initial space slice. These variables also yield a significant simplification of numerical work, since the fluid flow evolution equations become a system of ...

Energy Technology Data Exchange (ETDEWEB)

Abstract not provided

UK PubMed Central (United Kingdom)

Acquisition of three-alternative simultaneous matching-to-sample and oddity-from-sample was investigated. Five goldfish were trained on matching and five on oddity for a minimum of 70 days. Subsequently,...Full Text Available

International Nuclear Information System (INIS)

Boat sampling technique (BST) is a surface sampling technique, which has been developed for obtaining, in-situ, metal samples from the surface of an operating component without affecting its operating service life. The BST is non-destructive in nature and the sample is obtained without plastic deformation or without thermal degradation of the parent material. The shape and size of the sample depends upon the shape of the cutter and the surface geometry of the parent material. Miniature test specimens are generated from the sample and the specimens are subjected to various tests, viz. Metallurgical Evaluation, Metallographic Evaluation, Micro-hardness Evaluation, sensitisation test, small punch test etc. to confirm the integrity and assessment of safe operating life of the component. This paper highlights design objective of boat sampling ...

Energy Technology Data Exchange (ETDEWEB)

The previous {sup 58}Ni and {sup 60}Ni set of resonance parameters (Endf/B7.O, Jeff-3, etc.) was based on the SAMMY analysis of Oak Ridge National Laboratory neutron transmission, scattering cross section and capture cross section measurements by C.M. Perey et al. The present results were obtained by adding to the SAMMY experimental database the capture cross sections measured recently at the Oak Ridge Linear Electron Accelerator by Guber et al. and the Geel Electron Linear Accelerator and very high-resolution neutron transmission measurements performed by Brusegan et al. A complete resonance parameter covariance matrix (RPCM) was obtained from the SAMMY analysis of the experimental database. The data sets were made consistent, when needed, by adjusting the neutron energy scales, the normalization coefficients, and the background corrections. The RPCM allows the calculation of the cross section uncertainties due mainly to statistical errors in the experimental ...

Energy Technology Data Exchange (ETDEWEB)

The optical absorption spectra of the rhombohedral DyOF were measured at selected temperatures between 9 and 300 K. The emission spectra of the Dy{sup 3+} ion in the LaOF and GdOF matrices were obtained at 77 K and room temperature. The energy level scheme of Dy{sup 3+} (4f{sup 9} electron configuration) was simulated with a Hamiltonian of 20 parameters. The diagonalization of the energy matrices including simultaneously the free ion and crystal field (c.f.) interactions was carried out for the C{sub 3{upsilon}} point symmetry of the RE{sup 3+} site. Good correlation with an rms deviation of 17 cm{sup -1} was obtained between the experimental and calculated energy level schemes of 153 Kramers doublets. The c.f. parameters show only slight distortion from O{sub h} symmetry. A comparison to Pr{sup 3+} (4f{sup 2}), Nd{sup 3+} (4f{sup 3}), Sm{sup 3+} (4f{sup 5}), Eu{sup 3+} (4f{sup 6}), and Tb{sup 3+} (4f{sup 8} electron configuration) in other ...

British Library Electronic Table of Contents (United Kingdom)

We analyze the average of weak values over statistical ensembles of pre- and post-selected states. The protocol of weak values, proposed by Aharonov et al. [Phys. Rev. Lett. 60 (1988) 1351], is the result of a weak measurement conditional on the outcome of a subsequent strong (projective) measurement. Weak values can be beyond the range of eigenvalues of the measured observable and, in general, can be complex numbers. We show that averaging over ensembles of pre- and post-selected states reduces the weak value within the range of eigenvalues of Formula Not Shown . We further show that the averaged result expressed in terms of pre- and post-selected density matrices, allows us to include the effect of decoherence.

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In this systematic examination of some of the spectroscopic properties of the f-elements we deal with both the trivalent lanthanides and actinides. We summarize the present status of our energy level calculations in single crystal matrices and in aqueous solution, and compare the predicted crystal-field structure in certain low-symmetry sites with that observed. Some interesting new structural insights are thereby gained. The state eigenvectors from these calculations are then used in part in reassessing and interpreting the intensities of transitions in aqueous solution via the Judd-Ofelt theory. The parameters of this theory derived from fitting experimental data are compared with those computed from model considerations. Finally, we discuss some recent contributions to the interpretation of excited state relaxation processes in aqueous solution. 79 references, 23 figures, 17 tables.

British Library Electronic Table of Contents (United Kingdom)

In this study, the use of the weakly basic anion exchange resins of phenol-formaldehyde (Amberlyst A 23), polyacrylate (Amberlite IRA 67) and polystyrene (Lewatit MonoPlus MP 62) matrices for removal of the reactive dye Remazol Black B (RBB) from aqueous solution and wastewater were investigated. RBB sorption on the anion exchangers was a time dependent process. Color reduction percentiles of 75.2, 33.9 and 25.1% in wastewater treatment were found after 216 h of phase contact time with Lewatit MonoPlus MP 62, Amberlyst A 23 and Amberlite IRA 67, respectively. Inorganic salts and anionic surfactant action influenced RBB uptake by the anion exchangers. The amounts of dye retained by the anion exchangers increased with a rise in temperature. The maximum sorption capacities calculated from the...

International Nuclear Information System (INIS)

Analytical TEM and high resolution TEM were used in the microstructural characterization of hot-press sintered Si_3N_4-SiC platelets composites. The quantity of sintering additives, Er_2O_3 and AlN, was varied to produce different matrices, e. g. Si_3N_4, #beta#'+#alpha#'-Sialon and #alpha#'-Sialon. Detailed analysis of platelet-sialon matrix interfaces revealed the presence of AlN polytypoids. The polytypoids nucleate preferentially onto the (0001) plane of SiC and growth epitaxially in several ten nanometer layers contributing in this way to crystallize, partially, the matrix intergranular glass pockets contacting the platelets. Possible applications of the phenomena to microstructural control, grain boundary phase control and enhanced creep resistance are discussed. (orig.).

CERN Document Server

Computers understand very little of the meaning of human language. This profoundly limits our ability to give instructions to computers, the ability of computers to explain their actions to us, and the ability of computers to analyse and process text. Vector space models (VSMs) of semantics are beginning to address these limits. This paper surveys the use of VSMs for semantic processing of text. We organize the literature on VSMs according to the structure of the matrix in a VSM. There are currently three broad classes of VSMs, based on term-document, word-context, and pair-pattern matrices, yielding three classes of applications. We survey a broad range of applications in these three categories and we take a detailed look at a specific open source project in each category. Our goal in this survey is to show the breadth of applications of VSMs for semantics, to provide a new perspective on VSMs for those who are already familiar with the area, and to provide ...

CERN Document Server

Amplitudes for fermion-fermion, boson-boson and fermion-boson interactions are calculated in the second order of perturbation theory in the Lobachevsky space. An essential ingredient of the model is the Weinberg's 2(2j+1)-component formalism for describing a particle of spin j. The boson-boson amplitude is then compared with the two-fermion amplitude obtained long ago by Skachkov on the basis of the Hamiltonian formulation of quantum field theory on the mass hyperboloid, p_0^2 - p^2=M^2, proposed by Kadyshevsky. The parametrization of the amplitudes by means of the momentum transfer in the Lobachevsky space leads to same spin structures in the expressions of T-matrices for the fermion case and the boson case. However, certain differences are found. Possible physical applications are discussed.

CERN Document Server

Within standard quantum field theory of one scalar field we define operators conjugate to the energy-momentum operators of the theory. They are singled out by calculational simplicity in Fock space. In terms of the underlying scalar field they are non-local. We establish their algebra where it turns out that time and space operators do not commute. Their transformation properties with respect to the conformal group are derived. Solving their eigenvalue problem permits to reconstruct the Fock space in terms of the eigenstates. It is indicated how Paulis theorem may be circumvented. As an application we form the analogue of S-matrices which yields information on the structure of the underlying spacetime. Similarly we define fields and look at their equations of motion.

Energy Technology Data Exchange (ETDEWEB)

A computational environment, as a set of MapleV R.3 routines for doing symbolic calculations in Quantum Field Theory, is presented. The Q F T package`s routines extend the standard MapleV computational domain by introducing representations for anti commutative and noncommutative objects, tensors, spinors and gauge fields, as well as related objects and procedures (Dirac matrices, differential operators, functional differentiation w.r.t indexed fields, sum rule for repeated indices, etc.). Furthermore, the Q F T routines permit the user-definition of algebra rules for the commutation/ anti commutation of operators, to be taken into account during the calculations. (author) 2 refs.

Energy Technology Data Exchange (ETDEWEB)

This paper describes a method for preparing the sample handling and inlet system of a mass spectrometer for analysis of a subsequent sample following analysis of a previous sample comprising the flushing of the system interior with supercritical CO{sub 2} and venting the interior. The method eliminates the effect of system ``memory`` on the subsequent analysis, especially following persistent samples such as xenon and krypton.

Energy Technology Data Exchange (ETDEWEB)

A solid electrolyte for lithium batteries requires several properties: a good ionic conductivity of about 10{sup -3} S/cm at 298 deg. K, a high cationic transport number (greater than 0.5), a redox stability window higher than 4.5 V, a good stability of the interface with the lithium electrode, and a sufficient mechanical stability. The family of gelled or hybrid electrolytes seems to meet all these requirements. Thus, a systematic study of the gelling of an ethylene carbonate and lithium bistrifluorosulfonimide (LiTFSI) based electrolyte has been carried out. The polymers used for gel or pseudo-gel synthesis are POE, PMMA and PAN which represent 3 different cases of interaction with the electrolyte. All the properties mentioned above have been studied according to the nature of the polymer and to the concentration of lithium salt, showing the advantages and drawbacks of each polymer. The possibility of using some of these gels in lithium-ion batteries has been tested by lithium ...

UK PubMed Central (United Kingdom)

Feed samples from 94 cases involving fungal contamination and suspected mycotoxicosis of farm animals in western Canada were examined during 1982-1994 to assess the incidence of mycotoxins. Samples...Full Text Available

International Nuclear Information System (INIS)

The purpose of this report is to describe the sampling approaches, modifications made to the 100 Area and 300 Area component of the RCBRA Sampling and Analysis Plan, summarize validation efforts, and provide sample identification numbers.

Energy Technology Data Exchange (ETDEWEB)

The covariant quark model is shown to allow a phenomenological description of the neutron electric form factor, G{sub E}{sup n}(Q{sup 2}), in the impulse approximation, provided that the wave function contains minor ({approx}3%) admixtures of the lowest energy sea-quark configurations. While that form factor is not very sensitive to whether the q{sup -} in the qqqqq{sup -} component is in the P-state or in the S-state, the calculated nucleon magnetic form factors are much closer to the empirical values in the case of the former configuration. In the case of the electric form factor of the proton, G{sub E}{sup p}(Q{sup 2}) a zero appears in the impulse approximation close to 10 GeV{sup 2}, when the q{sup -} is in the P-state. That configuration, which may be interpreted as a pion loop ('cloud') fluctuation, also leads to a clearly better description of the nucleon magnetic moments. When the amplitude of the sea-quark admixtures are set so as to ...

CERN Document Server

We introduce an ad-hoc electrodynamics with advanced and retarded Lienard-Wiechert interactions plus the dissipative Lorentz-Dirac self-interaction force. We study the covariant dynamical system of the electromagnetic two-body problem, i.e., the hydrogen atom. We perform the linear stability analysis of circular orbits for oscillations perpendicular to the orbital plane. In particular we study the normal modes of the linearized dynamics that have an arbitrarily large imaginary eigenvalue. These large eigenvalues are fast frequencies that introduce a fast (stiff) timescale into the dynamics. As an application, we study the phenomenon of resonant dissipation, i.e., a motion where both particles recoil together in a drifting circular orbit (a bound state), while the atom dissipates center-of-mass energy only. This balancing of the stiff dynamics is established by the existence of a quartic resonant constant that locks the dynamics to the neighborhood of the recoiling ...

CERN Document Server

Learning to love the errror matrix lecture : Learning to love the errror matrix Introductory remarks. Conditional probability. Statistical and systematic errors. Combining results Binomial, Poisson and 1-D Gaussian 2-D Gaussian and the error matrix. Understanding the covariance. Using the error matrix. Estimating the error matrix. Combining correlated measurements Parameter determination by likelihood Do's and don'ts lecture : Parameter determination by likelihood : Do's and don'ts Introduction to likelihood. Error estimate. Simple examples: (1) Breit Wigner (2) Lifetime Binned and unbinned likelihood Several parameters Extended maximum likelihood. Common misapprehensions: Normalisation delta(lnL) = 1/2 rule and coverage Integrating the likelihood Unbinned L_max as goodness of fit Punzi effect Chi-squared and hypothesis testing lecture : Chi-squared and hypothesis testing Basic idea. Error estimates. Several parameters Correlated errors on y. Errors on x and y. ...

CERN Document Server

A linear structural equation model relates random variables of interest and corresponding Gaussian noise terms via a linear equation system. Each such model can be represented by a mixed graph in which directed edges encode the linear equations, and bidirected edges indicate possible correlations among noise terms. We study parameter identifiability in these models, that is, we ask for conditions that ensure that the edge coefficients and correlations appearing in a linear structural equation model can be uniquely recovered from the covariance matrix of the associated normal distribution. We treat the case of generic identifiability, where unique recovery is possible for almost every choice of parameters. We give a new graphical criterion that is sufficient for generic identifiability. It improves criteria from prior work and does not require the directed part of the graph to be acyclic. We also develop a related necessary condition and examine the "gap" between ...

Energy Technology Data Exchange (ETDEWEB)

Deformation in the overburden proves useful in deducing spatial and temporal changes in the volume of a producing reservoir. Based upon these changes we estimate diffusive travel times associated with the transient flow due to production, and then, as the solution of a linear inverse problem, the effective permeability of the reservoir. An advantage an approach based upon travel times, as opposed to one based upon the amplitude of surface deformation, is that it is much less sensitive to the exact geomechanical properties of the reservoir and overburden. Inequalities constrain the inversion, under the assumption that the fluid production only results in pore volume decreases within the reservoir. We apply the formulation to satellite-based estimates of deformation in the material overlying a thin gas production zone at the Krechba field in Algeria. The peak displacement after three years of gas production is approximately 0.5 cm, overlying the eastern margin of the anticlinal structure ...

Energy Technology Data Exchange (ETDEWEB)

San Francisco bus drivers have an increased prevalence of hypertension. This study examined relationships between blood lead concentration and blood pressure in 342 drivers. The analysis reported in this study was limited to subjects not on treatment for hypertension (n = 288). Systolic and diastolic pressure varied from 102 to 173 mm Hg and from 61 to 105 mm Hg, respectively. The blood lead concentration varied from 2 to 15 ..mu..g/dL. The relationship between blood pressure and the logarithm of blood lead concentration was examined using multiple regression analysis. Covariates included age, body mass index, sex, race, and caffeine intake. The largest regression coefficient relating systolic blood pressure and blood lead concentration was 1.8 mm Hg/ln (..mu..g/dL). The coefficient for diastolic blood pressure was 2.5 mm Hg/ln (..mu..g/dL). These findings suggest effects of lead exposure at lower blood lead concentrations than those concentrations that have ...

Science.gov (United States)

In this study, adjoint sensitivity theory is developed for equations of two-dimensional steady-state flow in a confined aquifer. Both the primary flow equation and the adjoint sensitivity equation are solved using the Galerkin finite element method. The developed computer code is used to investigate the regional flow parameters of the Leadville Formation of the Paradox Basin in Utah and the Wolcamp carbonate/sandstone aquifer of the Palo Duro Basin in the Texas Panhandle. Two performance measures are evaluated, local heads and velocity in the vicinity of potential high-level nuclear waste repositories. The results illustrate the sensitivity of calculated local heads to the boundary conditions. Local velocity-related performance measures are more sensitive to hydraulic conductivities. The uncertainty in the performance measure is a function of the parameter sensitivity, parameter variance and the correlation between parameters. Given a parameter covariance matrix, ...

CERN Document Server

All gauge theories need ``something fixed'' even as ``something changes.'' Underlying the implementation of these ideas all major physical theories make indispensable use of an elaborately designed spacetime model as the ``something fixed,'' i.e., absolute. This model must provide at least the following sequence of structures: point set, topological space, smooth manifold, geometric manifold, base for various bundles. The ``fine structure'' of spacetime inherent in this sequence is of course empirically unobservable directly, certainly when quantum mechanics is taken into account. This issue is at the basis of the difficulties in quantizing general relativity and has been approached in many different ways. Here we review an approach taking into account the non-Boolean properties of quantum logic when forming a spacetime model. Finally, we recall how the fundamental gauge of diffeomorphisms (the issue of general covariance vs coordinate conditions) raised deep ...

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This report documents the technical basis by which the workplace air monitoring and sampling program is operated in the 324 and 327 Buildings.

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 ... ...

UK PubMed Central (United Kingdom)

Here we describe the fabrication, optimization, and application of a microfluidic device that integrates microdialysis (MD) sampling, microchip electrophoresis (ME), and electrochemical detection...Full Text Available

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This Guideline provides a set of procedures for the measurement of organic contaminants and particles in producer gases from biomass gasifiers. The procedures are designed to cover different gasifier types (updraft or downdraft fixed bed or fluidised bed gasifiers), operating conditions (0 - 900C and 0.6-60 bars) and concentration ranges (1 mg/m{sub n}{sup 3} to 300 g/m{sub n}{sup 3}). The Guideline describes a modular sampling train, and a set of procedures, which include: planning and preparation of the sampling, sampling and post-sampling, analysis, calculations, error analysis and reporting. The modular sampling train consists of 4 modules. Module 1 is a preconditioning module for isokinetic sampling and gas cooling. Module 2 is a particle collection module including a heated filter. Module 3 is a tar collection module with a gas quench (optionally by ...

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Melanoma (Skin)

International Science & Technology Center (ISTC)

Development and Creation of Model Samples of Ecologically Safe Luminescent Lamps

KoreaScience (Korea)

Full Text Available

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We describe a procedure for correcting the systematic errors in the Moessbauer f-factor measurement due to non-homogeneous effective thickness of the sample. To be more precise, we show that, if the mass of the sample is determined by means of X- or {gamma}-ray absorption, it is possible to establish experimental conditions so that the error on f due to material non-homogeneity in the sample is minimized.

International Nuclear Information System (INIS)

This study illustrates the way to perform protocols, collect samples, and conduct laboratory analyses in order to characterize the physical properties of wood used in the industrial sector of the Valle de Aburra metropalitan area and the gains obtained by characterizing the properties of the most frequently used woods. In this investigation some of the most important sampling parameters are presented, such as taking samples in piles or accumulations of waste, handling of these samples in the laboratory and others of great importance such as the ignition point. the proposed methodology is based upon some of the international astm coal norms, for the similarity it has with wood and for the lack of information on sampling this type in wood

CERN Document Server

A systematic approach is followed in order to identify realistic D-brane models at toric del Pezzo singularities. Requiring quark and lepton spectrum and Yukawas from D3 branes and massless hypercharge, we are led to Pati-Salam extensions of the Standard Model. Hierarchies of masses, flavour mixings and control of couplings select higher order del Pezzo singularities, minimising the Higgs sector prefers toric del Pezzos with dP3 providing the most successful compromise. Then a supersymmetric local string model is presented with the following properties at low energies: (i) the MSSM spectrum plus a local B-L gauge field or additional Higgs fields depending on the breaking pattern, (ii) a realistic hierarchy of quark and lepton masses and (iii) realistic flavour mixing between quark and lepton families with computable CKM and PMNS matrices, and CP violation consistent with observations. In this construction, kinetic terms are diagonal and under calculational control ...

International Nuclear Information System (INIS)

Control of thermal expansion is often necessary in the design and selection of electronic packages. In some instances, it is desirable to have a coefficient of thermal expansion intermediate between values readily attainable with single or two phase materials. The addition of a third phase in the form of fillers, whiskers, or fibers can be used to attain intermediate expansions. To help design the thermal expansion of multiphase materials for specific applications, a closed form model has been developed that accurately predicts the effective elastic properties of isotropic filled materials and transversely isotropic lamina. Properties of filled matrix materials are used as inputs to the lamina model to obtain the composite elastic properties as a function of the volume fraction of each phase. Hybrid composites with two or more fiber types are easily handled with this model. This paper reports that results for glass, quartz, and Kevlar fibers with beta-eucryptite filled polymer ...

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The European Commission recently has adopted a new European Strategy for Environment and Health focusing on the growing concern over the adverse health effects caused by environmental pollution. Based on the results of various studies carried out in recent years polychlorinated dioxins and furans (PCDD/Fs) and PCBs are playing an important role in this strategy. In view of the enlargement of the European Union (EU) to include Candidate Countries (CCs) the Commission stressed the need to involve the Candidate Countries from an early stage on in the development of such a strategy. Thus two studies have been commissioned which are particularly directed to provide a) an overview on environmental levels and human exposure of dioxins and PCBs and b) an harmonised PCDD/F emission inventory for the target matrices air, water and land The latter study, entitled ''Dioxin Emissions in Candidate Countries'' is carried out by a consortium of ...

CERN Document Server

This paper deals with the computation of sectional curvature for the manifolds of~$N$ landmarks (or feature points) in~$D$ dimensions, endowed with the Riemannian metric induced by the group action of diffeomorphisms. The inverse of the metric tensor for these manifolds (i.e.~the cometric), when written in coordinates, is such that each of its elements depends on at most~$2D$ of the~$ND$ coordinates. This makes the matrices of partial derivatives of the cometric very sparse in nature, thus suggesting solving the highly non-trivial problem of developing a formula that expresses sectional curvature in terms of the cometric and its first and second partial derivatives (we call this Mario's formula). We apply such formula to the manifolds of landmarks and in particular we fully explore the case of geodesics on which only two points have non-zero momenta and compute the sectional curvatures of 2-planes spanned by the tangents to such geodesics. The latter example gives ...

International Nuclear Information System (INIS)

There are three main types of radiation-processed composite material derived from plastics and fibrous natural polymers. The first are the monomer-impregnated, radiation-treated wood-plastic composites (WPC). They became a commercial success in the early 1970s. More recently, work has focused on improving the WPCs by creating in them interpenetrating network (IPN) systems by the use of appropriate multifunctional oligomers and monomers. The main kinetic features of radiation-initiated chain polymerization remain applicable even in impregnated wood. The second type are the plastics filled or reinforced with dispersed wood fiber or other cellulosics (WFRP). In their case, radiation processing offers a new opportunity to apply radiation-reactive adhesion promoters between wood or cellulosic fibers and the thermoplastic matrices. The third type are the laminar composites made by electron beam coating of wood-based agglomerate sheets and boards. This chapter reviews the ...

International Nuclear Information System (INIS)

Researches on oil palm empty fruit bunch (EFB) fibers and thermoplastic composites have been carried out by many workers in the last decade. The main focus was to enhance the properties of the resultant composites in view of the incompatibility of the two components. Thus, efforts have been made to enhance their properties by using coupling agents, treating the fibers and modifying the matrices. In this study, the effects of electron beam (EB) irradiation and some reactive additives (RAs) on the mechanical properties of EFB-PP (polypropylene) composites were evaluated. Different modes of irradiation were investigated. Mono, di and tri functional of monomers of RAs were used. irradiating PP alone, compared to irradiating the EFB fibers or irradiating both components, gave optimum properties for EFB-PP composites. Further, improvements of the properties of the composites were achieved with the addition of RAs with TMPTA (trymethylol propane triacrylate) giving the ...

International Nuclear Information System (INIS)

We have constructed a specific supersymmetric flipped SU(5) GUT model in which bilarge neutrino mixing is incorporated. Because the up-type and down-type quarks in the model are flipped in the representations ten and five with respect to the usual SU(5), the radiatively generated flavor mixing in squark mass matrices due to the large neutrino mixing has a pattern different from those in the conventional SU(5) and SO(10) supersymmetric GUTs. This leads to phenomenological consequences quite different from SU(5) or SO(10) supersymmetric GUT models. That is, it has almost no impact on B physics. On the contrary, the model has effects in top and charm physics as well as lepton physics. In particular, it gives promising prediction on the mass difference, #DELTA#M_D, of the D-D-bar mixing which for some ranges of the parameter space with large tan#beta# can be at the order of 10"9 #Planck constant# s"-"1, one order of magnitude smaller than the experimental upper bound. ...

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Nowadays, the floating production, storage, and offloading (FPSO) units are used to marginal oil fields and deep seas, because of mobility and reduced lead time from discovery to first production. One of the methods for offloading is to moor a tanker alongside the FPSO unit. In this case motion response of the system becomes highly complex, and will be affected by many factors such as hydrodynamic interaction and mechanical connections between the vessels. In this study, a quite general method is developed which has taken into account the hydrodynamic interaction as well as the effects of connectors and mooring lines, in motion response analysis of a multi-body floating system. For this purpose, 3-D source distribution method is applied for hydrodynamic analysis, and linear stiffness matrices are introduced to represent the effect of connectors and mooring lines on the motion equations. The method has been used for motion analysis of a practical problem in which an ...

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 and at the hard edge ...

Science.gov (United States)

This paper presents a novel feature extraction scheme for roller bearing fault diagnosis utilizing generalized S transform and two-dimensional non-negative matrix factorization (2DNMF). The generalized S transform, which can make up the poor energy concentration of the standard S transform, is introduced to generate the time-frequency representation (TFR). Experiment results on simulated signal and vibration signals measured from rolling element bearings have revealed that the generalized S transform can obtain a more satisfactory TFR than other similar techniques. Furthermore, a new technique called two-dimensional non-negative matrix factorization (2DNMF), which can reduce the computation cost and preserve more structure information hiding in original 2D matrices compared to the NMF, is developed to extract more informative features from the time-frequency matrixes for accurate fault classification. Experimental results on bearing faults classification have ...

Science.gov (United States)

Electrospun nanofibers composed of biodegradable polymers are attractive candidates for cell culture scaffolds in tissue engineering. Their fine-meshed structures, resembling natural extracellular matrices, effectively interact with cell surfaces and promote cell proliferation. The application of electrospinning, however, is limited to two-dimensional (2D) or single tube-like scaffolds, and the fabrication of arbitrary three-dimensional (3D) scaffolds from electrospun nanofibers is still very difficult due to the fibers' continuous and entangled form. To address this issue, in this paper, we describe the use of phase-separation-assisted electrospray and electrostatic focusing to perform continuous direct 3D patterning of nanofibrous microcapsules of biodegradable polylactic acid (PLA). These microcapsules exhibit fiber-particle duality because they are composed of nanofibers suitable for cell attachment while also being easy to handle as particles for direct 3D ...

International Nuclear Information System (INIS)

The effect of Al and Be ions pre-implantation on microstructural change and, the formation and growth of He bubbles in SiC/SiC composite was investigated. Four kinds of ion implanted specimens were prepared with 100 appm Al, 1000 appm Al, 100 appm Be and 1000 appm Be implanted. No microstructural change was observed in the matrices and fibers of SiC/SiC composites implanted with Al or Be ions up to 1000 appm. The un-implanted and Al or Be pre-implanted SiC/SiC composites were simultaneously irradiated to 10 dpa using triple ion-beams (6.0-MeV Si"2"+, 1.0-MeV He"+ and 340-keV H"+) at 1000 deg. C. Helium bubbles were formed in every matrix and fiber irradiated by triple ion-beams. The size of He bubbles in the matrix was increased by implanting Al or Be ions and increased with increasing amount of implanted Al or Be ions. The size of He bubbles in the fiber was slightly increased by implanting Al or Be ions. These results suggest that Al or Be as transmutation ...

CERN Document Server

The Hamiltonian structure of the Classical Heisenberg Spin Chain (CHSC) has been extensively studied by a number of authors. First of all, we mention Faddeev and Thaktadjan that, in their fundamental monograph "Hamiltonian Methods in the Theory of Soliton", elucidate the main properties of both continuous and (semi-)discrete models. An analysis of the su(2) continuous model in the context of the reduction theory for Poisson Nijenhuis manifolds was performed by Magri et al in1985, while through a similar approach a few years later Ragnisco and Santini analyzed the discrete case. In the meantime, among the condensed matter community there was some renewed interest on Potts models, sort of generalized spin chains where the relevant field variable is allowed to take values at the $N^{th}$ roots of unity. The proper theoretical setting for such models, at least at the classical level, would have been the extension to NxN matrices of the approach followed by the ...

International Nuclear Information System (INIS)

1 - Description of program or function: This library for fusion neutronics calculations, to be used in conjunction with the TRANSX code, is the MATXS format version of ZZ-GEFF-2-GENDF from which it has been derived by means of the MATXSR NJOY module. It has a 175 neutron, 42 photon VITAMIN-J group structure with the standard weighting function: Maxwellian (at the temperature to which the material is referenced) + 1/E + fission spectrum + 1/E + fusion peak + 1/E. It includes 93 materials from 1-H-1 to Bi-209 - almost all from EFF-2 basic data; but Ag-107, Ag-109, natural Cd, the 6 Hf isotopes and the 4 W isotopes have been taken from JEF-2.2 - at 3 temperatures and 6 dilution cross section values; 10 thermal groups are provided below 3 eV. Neutron cross sections and diffusion matrices, photon and gas production, kerma and DPA are given. The library includes H in H2O, metallic Be and Graphite for which an accurate treatment with S(alpha, beta) ...

British Library Electronic Table of Contents (United Kingdom)

Differential Scanning Calorimetry (DSC) is employed to study the changes in enthalpy of natural rubber latex samples when heated under a controlled temperature program. It is found that the mass normalized areas of the DSC curves between room temperature and 170??C for different latex samples are inversely proportional to the dry rubber content (DRC) of the samples, measured following the weighing and drying method. The changes in total enthalpy of the samples in this temperature range are interpreted as due to the variations in the quantity of water present in the samples. The measurements have been repeated by diluting selected samples with known quantities of water, and it is found that the normalized areas of the DSC curves are directly proportional to the amount of water added to the ...

British Library Electronic Table of Contents (United Kingdom)

SummaryBackground The choice of sampling techniques in bronchoscopy with sampling from a visible lesion will depend on the expected diagnostic yields and the costs of the sampling techniques. Aims The aim of this study was to determine the most economical combination of sampling techniques when approaching endobronchial visible lesions. Methods A cost minimization analysis was performed. All bronchoscopies from 2003 and 2004 at Haukeland university hospital, Bergen, Norway, were reviewed retrospectively for diagnostic yields. 162 patients with endobronchial disease were included. Potential sampling techniques used were biopsy, brushing, endobronchial needle aspiration (EBNA) and washings. Costs were estimated based on registration of equipment costs and personnel costs. Sensitivity analyse...

International Nuclear Information System (INIS)

An easy and simple method for gamma assay of large multi-gamma lines samples was introduced in this work. This method performs the assay using point source calibration. The correction factors for volume and self-attenuation are experimentally deduced from the spectra of different thicknesses samples utilizing the following two simple well known facts: large and small samples of the same homogenous material have identical specific activities; the self-attenuation of gamma line decreases as its energy increases. The method was successfully applied to naturally occurring radioactive material (NORM) large samples. This method does not require complicated mathematical procedures. Neither sample matrix data nor detector unit composition is needed.

International Nuclear Information System (INIS)

This paperwork explain the method of water sampling to obtain the precipitate of BaCO3 solutions that will be used to analyze 13C from field work in Kelana Jaya, Selangor, Langkawi, Kedah and Taiping, Perak. The sampling involves collecting of water samples for groundwater from boreholes and surface water from canal, river, pond and ex-mining pond from several locations at the study sites. This study also elaborates the instruments and chemicals used. The main purpose of this sampling is to obtain the precipitate of BaCO3 for 13C analysis of dissolved inorganic carbon (DIC). A correct sampling method according to standard is very important to ensure an accurate and precise result. With this, the data from the laboratory analysis result can be fully utilized to make the interpretation of the pollutants movement. (Author)

Energy Technology Data Exchange (ETDEWEB)

The Waste Sampling and Characterization Facility (WSCF) complex consists of the main structure (WSCF) and four support structures located in the 600 Area of the Hanford site east of the 200 West area and south of the Hanford Meterology Station. WSCF is to be used for low level sample analysis, less than 2 mRem. The Laboratory features state-of-the-art analytical and low level radiological counting equipment for gaseous, soil, and liquid sample analysis. In particular, this facility is to be used to perform Resource Conservation and Recovery Act (RCRA) of 1976 and Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980 sample analysis in accordance with U.S. Environmental Protection Agency Protocols, room air and stack monitoring sample analysis, waste water treatment process support, and contractor laboratory quality assurance checks. The ...

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Samples of nylon 66 rods were irradiated using a cobalt-60 gamma ray source at a dose rate of 0.25 Mrad h[sup -1] in air at room temperature to a maximum dose of 500 Mrad. The linear coefficient of thermal expansion ([alpha]) was measured using a three-terminal capacitance technique reported previously. The variation of [alpha] with temperature between 10 K and 340 K was investigated for an unirradiated sample and two samples irradiated to 300 Mrad and 500 Mrad. In the range 10K to 160K, [alpha] is almost invariant with radiation dose and there is little difference between the values for the unirradiated and the 300 Mrad irradiated samples above 160 K. The sample irradiated to 500 Mrad does show a 6% increase in [alpha] over the other samples in the higher temperature range. All samples show an increase overall in the value of [alpha] with ...

UK PubMed Central (United Kingdom)

ObjectiveTo compare the relations of social self-control and sensation seeking with substance use across samples of US and Russian adolescents.Full Text Available

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This report presents results from the soil inorganic analysis of the 44th set of environmental quality assessment samples, of the quality assessment program, that were received on or before June 3, 1996. The samples were analyzed for RCRA metals.

UK PubMed Central (United Kingdom)

In this paper, we report a method of precise in situ x-ray scattering measurements on protein solutions using small stationary sample cells. Although reduction in the radiation damage...Full Text Available

UK PubMed Central (United Kingdom)

Linking biological samples found at a crime scene with the actual crime event represents the most important aspect of forensic investigation, together with the identification of the sample donor. While...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Adenosine triphosphate (ATP) is an indicator of living biomass in marine particulates. This report details the method used by Lawrence Berkeley Laboratory to analyze particulate ATP in samples taken from oligotrophic, tropical ocean waters. It represents a synthesis of previously published methods.

UK PubMed Central (United Kingdom)

Real-time PCR has the potential to streamline detection and identification of Cryptosporidium spp. in human clinical samples. In the present...Full Text Available

UK PubMed Central (United Kingdom)

The procedure currently used for isolating legionellae from environmental samples recommend filtration through a 0.2-microns-pore-size polycarbonate filter. In this study we evaluated the performance...Full Text Available

UK PubMed Central (United Kingdom)

The British Andrology Society guidelines for the assessment of post vasectomy semen samples recommend that initial assessment is undertaken 16 weeks post vasectomy and after the patient has produced...Full Text Available

UK PubMed Central (United Kingdom)

To diagnose asymptomatic bacterial vaginosis (BV), self-sampled vaginal smears were collected during a study of risk factors for preterm birth in African American women. More than 90% of those...Full Text Available

International Nuclear Information System (INIS)

(1974). Hungary Kolomiytsev, MA Dundua, V.Yu. Pachulia, NV Bagdavadze,

Science.gov (United States)

... analyze importance sampling schemes for stochastic networks ... an interesting mixed open/closed queueing network ... with a suitable terminal condition ...

International Nuclear Information System (INIS)

We have prepared high-quality, single crystals of SmB_6 under various conditions to improve sample quality. We have measured the resistivity and magnetic susceptibility from room to liquid-helium temperatures to sort samples. We have applied pulsed magnetic fields as high as 50 T at temperatures as low as 40 mK while measuring resistivity. Our samples are of higher quality than previously known. All solvent-grown, single-crystal samples should be etched to remove a surface conductivity. (orig.).

International Nuclear Information System (INIS)

This document defines the services the Waste Sampling and Characterization Facility (WSCF) shall provide Effluent Monitoring (EM) throughout the calendar year for analysis. The internal memo contained in Appendix A identifies the samples Em plans to submit for analysis in CY-1995. Analysis of effluent (liquid and air discharges) and environmental (air, liquid, animal, and vegetative) samples is required using standard laboratory procedures, in accordance with regulatory and control requirements. This report describes regulatory reporting requirements and WSCF services and data quality objectives.

International Nuclear Information System (INIS)

The elemental analysis of some plant samples have been carried out in Trabzon region (Turkey) using energy-dispersive X-ray fluorescence (EDXRF) spectrometry. We have analyzed plant samples for nine stations using 1.85 GBq 55Fe radioactive sources. We have found that potassium and calcium within 0.3-1.4% and 0.3-2.8% were present in concentration in plants for every station, respectively. The concentration of Cl and Ti generally changed according to the plant species and the sampling station.

Science.gov (United States)

... Since power spectral density measurements are the result of a statisti- cal sampling process, as are the probability measurements, we now ...

Energy Technology Data Exchange (ETDEWEB)

The composition and thickness of etch residues on the base of submicrometer via holes cannot be surmized from data on larger features. Auger sputter depth profiles were used to compare etch residues in 0.55 {mu}m via holes produced by different etch processes and remaining after different cleans. These residues varied significantly in composition and thickness with the processing history of the sample and from those on larger features. A focused ion beam (FIB) sample preparation was developed to expose the bases of via holes and to help reduce sample charging. (author).

Science.gov (United States)

... by starting and remaining in that size hotel. Another early study, conducted by Nailon (1968) sampled three general managers ...

International Nuclear Information System (INIS)

Examples are given of reference materials for radionuclide X-ray fluorescence analysis (RXFA) of the environment processed by the National Bureau of Standards and the IAEA. Methods are described used for preparing standard materials for RXFA. For determining air pollutants the sample is prepared by dry or wet mineralization. Water samples have to be preserved prior to analysis. Insoluble components are separated by filtration or centrifugation. Biological materials must be dehydrated and homogenized. Samples of soil, sludges, sediments and solid wastes will sometimes have to be converted into a solution in some cases a leachate will have to be obtained. (ES).

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A method for the quantitative determination of atmospheric hydroperoxyl radical comprising: (a) contacting a liquid phase atmospheric sample with a chemiluminescent compound which luminesces on contact with hydroperoxyl radical; (b) determining luminescence intensity from the liquid phase atmospheric sample; and (c) comparing said luminescence intensity from the liquid phase atmospheric sample to a standard luminescence intensity for hydroperoxyl radical. An apparatus for automating the method is also included.

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DOE`s Office of Environmental Management (EM) is responsible for managing waste and cleaning up contamination at DOE sites across the United States. A substantial fraction of the work performed for EM includes sampling and analysis activities. This paper outlines the Sample Management Programs, achievements to date, and future directions.

International Nuclear Information System (INIS)

Efficiency calibration curves for different densities and geometries are necessary for activity determination of various environmental samples. Commercially available standards or natural radioactive materials are used for calibration. Potassium compounds are especially suitable, since they can be mixed with unknown samples. It is possible to determine efficiency curve and unknown activity of sample knowing "4"0 K activity. (author).

British Library Electronic Table of Contents (United Kingdom)

Surveillance of a population, such as a weapon stockpile, is needed to discover manufacturing defects as well as deterioration as the population ages. This article considers the risks of sampling rates for surveillance from three perspectives: detection probability of defects in a proportion of a population with pass/fail data, detection of a trend in a defective proportion of the population with pass/fail data, and detection of a trend with quantitative degradation measurements. Understanding of these risks will help the decision maker choose a sampling rate to protect against such problems of a specified size at a tolerable risk.

Energy Technology Data Exchange (ETDEWEB)

The Oligocene Kishenehn Formation of northwest Montana and southeast British Columbia consists of fluvial and lacustrine sediments (marlstones, lignites and oil shales) deposited in an elongate, intermontane half-graben. The petroleum source rock potential and steroidal hydrocarbon distribution of selected shales of the Kishenehn Formation were examined. Several steroidal hydrocarbon series were documented, including 4-desmethylsteranes, 4-methylsteranes, sterenes, diasterenes, spirosterenes, C-ring monoaromatic steroids and B-ring monoaromatic anthrasteroids. Non-steroid hydrocarbons present include hopenes, ..beta beta..-hopanes, moretanes, perylene, botryococcane, a series of alkylcyclohexanes, and a fused-ring aromatic tentatively identified as a tetrahydrochrysene. Source rock analysis indicates that the Kishenehn Formation possesses excellent petroleum source potential. Conventional thermal maturity parameters, as well as maturity parameters derived from molecular parameters ...

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The relationships between severity of iron deficiency anemia, response to iron treatment, respiratory and gastrointestinal illness and weight changes were assessed before (T1) and after (T2) iron therapy. Seventy-five pre-school children from rural Guatemala received daily oral iron (ferrous sulfate 5 mg/kg/day) for eleven weeks, and were classified into one of three groups: (1) severe iron deficient (Hgb < 9.25 g/dl at T1 and > 1g/dl Hgb response (T2-T1) to Fe Rx; (2) moderately iron deficient (Hgb 9.25 g/dl to 11.5 g/dl and T2-T1 > 1g/dl); (3) normal controls (Hgb > 11.5 g/dl and T2-T1 < 1g/dl). When both severely and moderately anemic children were pooled together, there was a statistical significant difference between the number of days ill with gastrointestinal symptoms of these children and those in the control group. Children with T1 Hgb > 11.5 had more days ill than those classified as severely or moderately anemic. There was no other statistically significant ...

Science.gov (United States)

Data from 52 litters farrowed in two seasons of a cross-fostering experiment were analyzed to estimate variances and covariances for additive direct and maternal genetic effects on immune response to pseudorabies virus and B. bronchiseptica vaccine. Twenty purebred boars and 44 sows of the Duroc, Landrace and Yorkshire breeds were used. Immune response was measured after vaccine challenge. A modified-live pseudorabies (PR) vaccine was administered to piglets at 28 d of age; response was measured by log2 serum neutralization titers at 56 d. An inactivated B. bronchiseptica bacterin was administered at 28, 42 and 112 d. Antibody levels were measured relative to positive and negative controls at 28, 56 and 119 d by using an enzyme-linked immunosorbent assay (ELISA). Results from this study for heritability were .18 +/- .09 for PR titer and .15 +/- .07 and .52 +/- .15 for 56- and 119-d ELISA values, respectively. The variability due to nurse environment (maternal ...

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To obtain Pinus wood-plastic composites, wood samples were impregnated with methyl methacrylate and polymerized by the use of gamma rays from a /sup 60/Co at different dose exposure and total dose. The best percentage of polymerization was obtained with the exposure of 2.0 MR of gamma radiation. It was found that the impregnation and polymerization, determined by the density values along the samples were uniform. The density became 2.6 times higher in relation to the control samples. The storage of the impregnated wood samples showed losses of the monomer, even when wrapped with aluminum or polyethylene film. It is recommended that the wood samples should be irradiated soon after impregnation.

International Nuclear Information System (INIS)

A new furnace for neutron diffraction experiments is capable of heating and cooling a sample very rapidly. The rapid heating is done by two circular infrared lamps placed over and under a sample, whose radiation is roughly focused on the sample by a reflector. The rapid cooling is done by high-pressure gas blows against the sample from two circular nozzles which are also placed over and under the sample. This system enables us to obtain the heating rate of over 1000"0C/min and cooling rate of -500"0C/min for an alloy of 10 mm diameter and 30 mm length. The performance is sufficient to carry out some kinetics measurements in real-time neutron diffraction by the use of a position-sensitive detector. This kind of experiment is demonstrated by the observation of the relaxation process of order--disorder transitions in CuZn and Ni_3Mn alloys.

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Focus Ion Beam (FIB) milling has greatly extended the utility of atom probe and TEM because it enables sample preparation with a level of dimensional control never before possible. Using FIB it is possible to extract the samples from desired and very specific locations. The artifacts associated with this sample preparation method must also be fully understood. In this work issues specifically relevant to the FIB milling of aluminum alloys are presented. After using the FIB as a sample preparation technique it is evident that gallium will concentrate in three areas of the sample: on the surface, on grain boundaries and at interphase boundaries. This work also shows that low energy Ar ion nanomilling is potentially quite effective for removing gallium implantation layers and gallium from the internal surfaces of aluminum thin foils.

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Forensic signatures are present in any Pu sample that can determine the sample`s origin: isotopic ratio of Pu, progeny species that grow into the sample, and contaminant species left over from incomplete purification of the Pu in fuel reprocessing. In the context of intelligence information, this can result in attribution of responsibility for the product of clandestine proliferant operations or material smuggled from existing stockpiles. A list of signature elements and what can be determined from them have been developed. Work needs to be done in converting concentrations of signature species into a quantitative forensic analysis, particularly in regard to reactor performance, but this should require only a small effort. A radiochemical analysis scheme has been developed for measuring these nuclides; more work is needed, particularly for determining fission product concentrations. A sample of Pu metal ...

Energy Technology Data Exchange (ETDEWEB)

In this work was made an assessment of the supramolecular structures presents into human breast tissue normal and pathological samples, as well as into two types of animals samples (tendon chicken and pork fat) using the small angle x-ray scattering (SAXS) technique. The scattering profiles of the samples were determined at the momentum transfer range O.150nm{sup -1}<=5:q(=4pi.sin({theta}/2)/{lambda})<=8.500nm{sup -1}. In this range, it was possible identify structures corresponding to collagen fibrils (glandular tissue) and to triacylglycerides (adipose tissue) from the correlation between the information extracted from the human breast tissues scattering profiles and those extracted from animals samples. (author)

International Nuclear Information System (INIS)

Full text: A Large Sample Neutron Activation Analysis (LSNAA) facility is under development at GRR-1 research reactor, NCSR 'Demokritos'. The LSNAA facility design incorporates sample irradiation in the reactor's graphite thermal neutron column and subsequent measurement of the activity induced at a gamma spectroscopy system with gamma ray transmission measurement options included. Monte Carlo neutron and photon transport code MCNP-4C was used to model the facility. Appropriate correction factors accounting for neutron field perturbation during sample irradiation, high purity germanium detector efficiency for the volume source and gamma ray self-absorption within the sample itself were derived. The results of the computations were experimentally verified by activation foil measurements for a set of known materials and a range of sample sizes extending up to 10 litters. Moreover, the ...

Science.gov (United States)

The progress of digital audio technology enabled the familiar use of the products such as CD and DAT in the acoustic measurement. For example, a signal reproduced with CD player is inputted into a subject of measurement and DAT recorder records its response. However, the sampling cannot be synchronized completely with the input signal although both nominal sample rates are set up equally, because player and recorder work independently. It is the most popular software solution to perform the synchronous addition after converting the recorded signal into the original sampling rate. However, the rate conversion also has the error due to the windowing in the high frequency region of processed signal. This paper proposes a new method for averaging asynchronous sampling data to solve these problems. To evaluate performance, the transfer function of only measuring equipment estimated from asynchronous ...

Energy Technology Data Exchange (ETDEWEB)

Microstructural evolution due to thermal effects was studied in micro solder joints (55 {+-} 5 {micro}m). The composition of the Sn/Pb solder studied was found to be hypereutectic with a tin content of 65--70 wt%.This was determined by Energy Dispersive X-ray analysis and confirmed with quantitative stereology. The quantitative stereological value of the surface-to-volume ratio was used to characterize and compare the coarsening during thermal cycling from 0--160 C to the coarsening during annealing at 160 C. The initial coarsening of the annealed samples was more rapid than the cycled samples, but tapered off as time to the one-half as expected. Because the substrates to which the solder was bonded have different thermal expansion coefficients, the cycled samples experienced a mechanical strain with thermal cycling. The low-strain cycled samples had a 2.8% strain imposed on the solder and failed by ...

International Nuclear Information System (INIS)

A simple sample decomposition and laser fluorimetric determination of uranium at trace level is reported in certain refractory minerals, like ilmenite, rutile, zircon and monazite; environmental samples viz. soil and sediments; industrial waste materials, such as, coal fly ash and red mud. Ilmenite sample is decomposed by heating with ammonium fluoride. Rutile, zircon and monazite minerals are decomposed by fusion using a mixture of potassium bifluoride and sodium fluoride. Environmental and industrial waste materials are brought into solution by treating with a mixture of hydrofluoric and nitric acids. The laser induced fluorimetric determination of uranium is carried out directly in rutile, zircon and in monazite minerals and after separation in other samples. The determination limit was 1 #mu#g x g"-"1 for ilmenite, soil, sediment, coal fly ash and red mud samples, and it is 5 ...

International Nuclear Information System (INIS)

To make the doubly labelled water method for determining energy expenditure more applicable in a free-living population, collection of a single daily urine or breath sample would have advantages compared to a 24-hr urine collection. Coward et al. reported the use of a single daily urine sample. In the previously described study, a single urine collection and a fasting morning breath sample were collected from four men during two 21-day periods (fall, F, spring, S) while maintaining their body wts. on controlled diets (20% calories from protein, 40% from fat, 60% from CHO [F]; 20% protein, 20% fat, 60% CHO [S]). Urine and breath samples were analyzed to determine disappearance rates of D and "1"8O for up to 21 days. Values were compared with metabolizable energy intake levels (EI), with or without corrections for estimated changes in body composition assessed by several methods. Preliminary evaluations ...

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ESH-19 personnel collected soil and single-stage water samples around the perimeter of Area G at Los Alamos National Laboratory (LANL) during FY 95 to characterize possible radionuclide movement out of Area G through surface water and entrained sediment runoff. Soil samples were analyzed for tritium, total uranium, isotopic plutonium, americium-241, and cesium-137. The single-stage water samples were analyzed for tritium and plutonium isotopes. All radiochemical data was compared with analogous samples collected during FY 93 and 94 and reported in LA-12986 and LA-13165-PR. Six surface soils were also submitted for metal analyses. These data were included with similar data generated for soil samples collected during FY 94 and compared with metals in background samples collected at the Area G expansion area.

Energy Technology Data Exchange (ETDEWEB)

Microorganisms associated with fractured basalt core were compared to those suspended in groundwater pumped from the same well in the eastern Snake River Plain Aquifer (Idaho, USA). Two wells influenced to different degrees by a mixed-waste plume in the fractured basalt aquifer were examined. In one well, an array of dialysis cells filled with either deionized water or crushed basalt was equilibrated to compare the microorganisms collected in this fashion with those from core and groundwater samples collected in a traditional manner from the same well. Analyses were performed to characterize these samples and to provide a basis for comparison. These included total cell counts by microscopy; total biomass by phospholipid fatty acid analysis; enumerations of viable aerobic heterotrophs, groups of putative aerobic co-metabolic TCE-degraders and aerobic H2-oxidizing bacteria; mineralization of 14C- labeled acetate; and enrichments for dissimilatory ...

Energy Technology Data Exchange (ETDEWEB)

This paper presents the characteristics of selected parameters of organic matter of the Tertiary coal samples and organic matter of Carboniferous rock samples from the Spitsbergen. The coal samples were taken from Central Coal Basin (the Longyearbyen region) and from the Forlandsundet Basin (Oscar II Land, the Kaffioyra region). Samples of dispersed organic matter were collected from Suffolk Pynten and Sergeijevfjellet area in Sorkapp Land. The optical properties of coal samples are different from properties of dispersed organic matter. Macerals of vitrinite group dominate in all of the samples. The average content of vitrinite group macerals is much lower in dipersed organic matter samples than it is in coals. The average content of liptinite group macerals is a little lower, and inertinite group macerals is much higher. The average content ...

Science.gov (United States)

The brain hypothermia treatment is an attractive therapy for the neurologist because of its neuroprotection in hypoxic-ischemic encephalopathy patients. The present paper deals with the possibility of controlling the brain and other viscera in different temperatures from the viewpoint of system control. It is theoretically attempted to realize the special brain hypothermia treatment to cool only the head but to warm the body by using the simple apparatus such as the cooling cap, muffler and warming blanket. For this purpose, a biothermal system concerning the temperature difference between the brain and the other thoracico-abdominal viscus is synthesized from the biothermal model of hypothermic patient. The output controllability and the asymptotic stability of the system are examined on the basis of its structure. Then, the maximum temperature difference to be realized is shown dependent on the temperature range of the apparatus and also on the maximum gain determined from the ...

International Nuclear Information System (INIS)

The UV-vis-NIR absorption spectra of DyOCl were measured at selected temperatures between 9 and 300 K. The emission spectra of Dy"3"+ in LaOCl and GdOCl were obtained at 77 K and room temperature. The energy level scheme of Dy"3"+ was simulated with the aid of a phenomenological theory of simultaneously taking into account both the free ion and crystal field (c.f.) effects. The model included 14 adjustable parameters describing the electrostatic and the configuration interaction as well as the spin-orbit coupling. The c.f. effect was accounted for by the five non-zero B"k_q parameters according to the C_4_v point symmetry of Dy"3"+. Good simulation of the experimental energy level scheme was achieved with a r.m.s. deviation of 21 cm"-"1 between the experimental and calculated energy level schemes of 179 Kramers doublets. A comparison to Pr"3"+(4f"2), Nd"3"+ (4f"3), Sm"3"+ (4f"5), Eu"3"+ (4f"6), Tb"3"+ (4f"8), Ho"3"+ (4f"1"0), Er"3"+ (4f"1"1), and Tm"3"+ (4f"1"2 electron configuration) ...

Energy Technology Data Exchange (ETDEWEB)

The authors are developing MP-TOUGH2 for exploiting massively parallel computers. The goals of this effort are to (1) create a data-parallel subsurface transport code for solving larger problems than currently practical on workstations, (2) write portable code that can take advantage of scalability to run on machines with more processors, and (3) minimize the necessity for additional validation and verification of the resulting code. The initial strategy they have followed is to focus on optimizing the generic and time-consuming task of linear equation solution while leaving the bulk of TOUGH2 unmodified. In so doing, they have implemented a massively parallel direct solver (MPDS) that takes advantage of the banded structure of TOUGH2 Jacobian matrices. The authors have compared timings of the iterative conjugate gradient solvers DSLUBC, DSLUCS, and DSLUGM written in Fortran77 for the front end with the MPDS which uses the data parallel unit. The MPDS shows good ...

Energy Technology Data Exchange (ETDEWEB)

A Norwegian Research Program on Improved Oil Recovery (IOR) in North Sea reservoirs was launched in 1992. Microbial methods, applied in this context, is a part of this program. The scope, the methodological approach, and results from the three first years are presented. Water profile control, using biomass to block high permeable zones of a reservoir, has been investigated using nitrate-reducing bacteria in the injected sea water as plugging agents. Emphasis has been put on developing a process that does not have disadvantages secondary to the process itself, such as souring and impairment of the overall injectivity of the field. Data from continuous culture studies indicate that souring may successfully be mitigated by adding nitrite to the injected seawater. The morphology and size of generic-nitrate-reducing seawater bacteria have been investigated. Screening of growth-promoting nutrients has been carried out, and some sources were detected as favorable. Transport and penetration of ...

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There are various reasons for preferring local (e.g., three bump) orbit correction methods to global corrections. One is the difficulty of solving the mN equations for the required mN correcting bumps, where N is the number of superperiods and m is the number of bumps per superperiod. The latter is not a valid reason for avoiding global corrections, since, we can take advantage of the superperiod symmetry to reduce the mN simultaneous equations to N separate problems, each involving only m simultaneous equations. Previously, I have shown how to solve the general problem when the machine contains unknown magnet errors of known probability distribution; we made measurements of known precision of the orbit displacements at a set of points, and we wish to apply correcting bumps to minimize the weighted rms orbit deviations. In this report, we will consider two simpler problems, using similar methods. We consider the case when we make M beam position measurements per superperiod, and we ...

Energy Technology Data Exchange (ETDEWEB)

The radical cations from aziridine and azetidine have been characterized by ESR spectroscopy following their generation in the solid state by ..gamma.. irradiation of dilute solutions of the parent compounds in the CFCl/sub 3/ matrix at 77 K. The ESR parameters of the azetidine radical cation are typical of those for nitrogen-centered amine radical cations such as Me/sub 2/NH*/sup +/. On the other hand, the radical cation formed from aziridine has very different ESR parameters that compare closely to those for the isoelectronic C...C ring-opened form of the oxirane radical cation and the allyl radical. The radical cation formed from azetidine is therefore assigned a ring-closed structure with the unpaired electron in a 2p/sub z/ orbital on nitrogen perpendicular to the ring plane, whereas the cation from aziridine is an allylic C...C ring-opened planar isomer with the unpaired electron in a nonbonding ..pi.. orbital centered mainly on the two end carbon atoms. The neutral 1-aziridinyl ...

Energy Technology Data Exchange (ETDEWEB)

The field of neutron imaging has a broad scope of applications and has played a pivotal role in visualizing and quantifying hydrogenous masses in metallic matrices. The field continues to expand into new applications with the installation of new neutron imaging facilities. In this scope, a neutron imaging facility for computed tomography and real-time neutron radiography is currently being developed around 2.0 MW TRIGA MARK-II Reactor at Maamora Nuclear Research Centre in Morocco (CENM). The neutron imaging facility consists of a neutron collimator, a real-time neutron imaging system and imaging process systems. In order to reduce the gamma-ray content in the neutron beam, the reactor tangential channel was selected. For power of 250 kW, the corresponding thermal neutron flux measured at the inlet of the tangential channel is around 3.10{sup 11} n*cm{sup 2}/s. This facility will be based on a conical neutron collimator with two circular diaphragms with diameters of ...

International Nuclear Information System (INIS)

Host matrices for actinide immobilisation will undergo the formation of large helium quantities due to alpha decay. Helium diffusion rate has to be known in order to predict the long-term behaviour of the material, and particularly, the influence of helium accumulation on mechanical properties. A nuclear reaction analysis method, namely the "3He(d, p)"4He reaction, has been used to analyse the evolution of "3He profiles after ion implantations at 1 and 3 MeV in two materials, monoclinic ZrO_2 (as a test material) and Ca_9Nd(PO_4)_5(SiO_4)F_1_._5(OH)_0_._5 britholite (envisaged for Am and Pu long-term storage). Two data processing methods are used: the classical excitation curve (proton yields versus deuteron energy) and second, the proton energy spectrum for a given deuteron energy. The characteristics of the "3He profiles (depth, width) obtained by both methods are compared to SRIM estimations. Their evolution during subsequent annealings allows an estimation of ...

International Nuclear Information System (INIS)

Laser excited luminescence and site selective excitation spectra of trivalent terbium (Tb"3"+) in two rare earth oxyfluoride (ROF) matrices, LaOF and GdOF, were detected at temperatures down to liquid helium. From the analyses of spectra, the crystal field (c.f.) fine structure of the "7F_J (J=0-6) ground multiplet was obtained for the 4f"8 electron configuration. The energy level schemes comprising 26 c.f. sublevels out of 33 allowed for the C_3_v point symmetry of the R"3"+ site were simulated according to a phenomenological model taking into account only the c.f. effect. The simulation including six c.f. parameters (B_0"2, B_0"4, B_3"4, B_0"6, B_3"6, and B_6"6) reproduced the experimental energy level schemes in a satisfactory manner with rms deviations of 5 and 6 cm"-"1 for the LaOF and GdOF hosts, respectively. The c.f. parameter sets are characterized by B_0"2 values close to zero while the fourth and sixth rank parameters assumed rather high values. The O_h ...

International Nuclear Information System (INIS)

The optical spectra of actinide ions in the compound AnCl_3 and doped into single crystal LaCl_3 were interpreted in terms of transitions within 5f"N configurations. Energy-level calculations were carried out using an effective operator Hamiltonian, the parameters of which were determined by fitting experimental data. Atomic and crystal-field matrices were diagonalized simultaneously assuming an approximate D_3_h site symmetry. The spectroscopic data were taken from the literature but in most cases supplemented by unpublished measurements in absorption and in fluorescence. Spectroscopic data for each ion were analyzed independently, then the model parameters were intercompared and in many cases adjusted such that in the final fitting process the principal interactions showed uniform trends in parameter values with increasing atomic number. Consistent with analyses of the spectra of lanthanide ions in both LaCl_3 and LaF_3, abrupt changes in magnitude of certain ...

Energy Technology Data Exchange (ETDEWEB)

Six illitized samples from drillhole OL-KR12 in Olkiluoto were analyzed by helium gas methods for their diffusion coefficient, permeability and porosity. The diffusion coefficients measured varied in the range 2.1 x 10-10 - 3.5 x 10-8 m2/s, permeabilities in the range 6 x 10-21 - 5.8 x 10-16 m2, and porosities in the range 0.2 6.2%. Variations observed in these quantities were concluded to arise from the heterogeneous structure of the sample rock. A 4 mm x 4 mm x 4 mm subsample was sawed from each of the six samples for structural analysis by x-ray microtomography. The three-dimensional structure of tomographic reconstructions, and thereby that of the samples themselves, was analyzed visually, which confirmed their heterogeneity. Samples represent altered rock whose structure and thereby transport properties vary significantly depending on the local alteration history of the rock. ...

CERN Document Server

We present the results of an isophotal shape analysis of three samples of galaxies in the Coma cluster. Quantitative morphology, together with structural and photometric parameters, is given for each galaxy. Special emphasis has been placed on the detailed classification of early-type galaxies. The three samples are: i) a sample of 97 early-type galaxies brighter than m_B = 17.00 falling within one degree from the center of the Coma cluster; these galaxies were observed with CCD cameras, mostly in good to excellent resolution conditions; ii) a magnitude complete sample of 107 galaxies of all morphological types down to m_B = 17.00 falling in a circular region of 50 arcmin diameter, slightly offcentered to the North-West of the cluster center; the images for this and the next sample come from digitized photographic plates; iii) a complete comparison sample of 26 ...

International Nuclear Information System (INIS)

In an attempt to obtain basic data for evaluation of exposure doses in Niigata Prefecture, the concentrations of tritium in atmospheric water, precipitation, river water, and tap water were measured. Samples of atmospheric water, river water, and tap water were collected once for 2 weeks; and precipitation collected for one week was used as sample. The concentration of atmospheric tritium depended on the concentration of tritium in moisture and the content of water in atmosphere. Tritium levels were high in May, November and March, and low in September. Regarding tritium concentrations, there was a good correlation between atmospheric water and precipitation. Tritium concentrations in both of them varied from sample to sample. The concentrations of tritium in river and tap water tended to be high during spring and low during summer and winter, although the variations were not so great as those in ...

Energy Technology Data Exchange (ETDEWEB)

A total of 10 samples disks of 2024-T3 aluminum and 4130 ferrous steel were exposed to rocket-triggered lightning currents at the Kennedy Space Center test site in Florida during the summer of 1990. The experimental configuration was arranged so that the samples were not exposed to the preliminary streamer, wire-burn, or following currents that are associated with an upward-initiated rocket-triggered flash but which are a typical of naturally initiated lightning. Return-stroke currents and continuing currents actually attaching to the sample were measured, augmented by close-up video recordings of approximately 3 feet of the channel above the sample and by 16-mm movies with 5-ms resolution. From these data it was possible to correlate individual damage spots with streamer, return-stroke, and continuing currents that produced them. Substantial penetration of 80-mil aluminum was produced by a continuing ...