WorldWideScience
1

Ab initio calculations in a uniform magnetic field using periodic supercells  

Energy Technology Data Exchange (ETDEWEB)

We present a formulation of ab initio electronic structure calculations in a finite magnetic field, which retains the simplicity and efficiency of techniques widely used in first principles molecular dynamics simulations, based on plane-wave basis sets and Fourier transforms. In addition we discuss results obtained with this method for the energy spectrum of interacting electrons in quantum wells, and for the electronic properties of dense fluid deuterium in a uniform magnetic field.

2003-10-21

2

Fourier-transform infrared anisotropy in cross and parallel sections of tendon and articular cartilage  

UK PubMed Central (United Kingdom)

BackgroundFourier Transform Infrared Imaging (FTIRI) is used to investigate the amide anisotropies at different surfaces of a three-dimensional cartilage or tendon block. With the...Full Text Available

3

Sidelobe Suppression in an Acousto-Optic Filer with a Raised ...  

Science.gov (United States)

... Abstract : The acousto-optic filter (AOF) is ... for large switch networks. ... FOURIER TRANSFORMATION, OPTICAL SWITCHING, SURFACE ACOUSTIC ...

1992-04-01

4

Synthesis and characterization of Fe3O4Gg nanocomposites and their antibacterial performance  

British Library Electronic Table of Contents (United Kingdom)

We synthesized Fe3O4Gg nanocomposites through a combination of solvothermal, hydrothermal, and chemical redox reactions. Characterization of the resulting samples by X-ray diffraction, Fourier-transform infrared spectroscopy, field-emission scanning and transmission electron microscopy, and magnetic measurement is reported. Compared to Fe3O4g nanocomposites, the Fe3O4Gg nanocomposites showed enhanced antibacterial activity. The Fe3O4Gg nanocomposites were able to almost entirely prevent growth of Escherichia coli when the concentration of Ag nanoparticles was 10mg/mL. Antibacterial activity of the Fe3O4Gg nanocomposites was maintained for more than 40h at 37^oC. The intermediate carbon layer not only protects magnetic core, but also improves the dispersion and antibacterial activity of the...

2011-01-01

5

The forward modeling and reverse time migration of seismic wave field in complex medium  

Energy Technology Data Exchange (ETDEWEB)

The space derivation term of a wave equation is accurately calculated using Fourier transform method, and the wave equation only relating to time derivative in time-space domain is derived. Solving this equation with the aid of central difference method brings the numerical recursion formula for forward modeling or reverse time migration of seismic wave field in the medium in which seismic velocity varies. The key to this method lies in introducing two auxiliary wave fields relating to velocity and spacial frequency of Fourier transform respectively after multi-dimensional Fourier transform respectively after multi-dimensional Fourier transform of space vector is made. Theoretically, this method is suitable to the forward modeling and migration of seismic wave field in complex area where seismic velocity and structure ...

1988-01-01

6

Optical Spectroscopy for Noninvasive Monitoring of Stem Cell Differentiation  

UK PubMed Central (United Kingdom)

There is a requirement for a noninvasive technique to monitor stem cell differentiation. Several candidates based on optical spectroscopy are discussed in this review: Fourier transform infrared (FTIR)...Full Text Available

2010-01-01

8

Magnetic nanoparticle (Fe3O4) impregnated onto tea waste for the removal of nickel(II) from aqueous solution  

British Library Electronic Table of Contents (United Kingdom)

The removal of Ni(II) from aqueous solution by magnetic nanoparticles prepared and impregnated onto tea waste (Fe3O4-TW) from agriculture biomass was investigated. Magnetic nanoparticles (Fe3O4) were prepared by chemical precipitation of a Fe^2^+ and Fe^3^+ salts from aqueous solution by ammonia solution. These magnetic nanoparticles of the adsorbent Fe3O4 were characterized by surface area (BET), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Fourier Transform-Infrared Spectroscopy (FT-IR). The effects of various parameters, such as contact time, pH, concentration, adsorbent dosage and temperature were studied. The kinetics followed is first order in nature, and the value of rate constant was found to be 1.90x10^-^2min^-^1 at 100mgL^-^1 and 303K. Removal ef...

2011-01-01

9

A facile method for the room-temperature synthesis of water-soluble magnetic Fe3O4 nanoparticles: Combination of in situ synthesis and decomposition of polymer hydrogel  

British Library Electronic Table of Contents (United Kingdom)

We propose and demonstrate a facile room-temperature synthetic method for obtaining water-soluble magnetic Fe3O4 nanoparticles (NPs) by combining the in situ synthesis and decomposition of a magnetic polymer hydrogel. The Fe3O4 NPs with average diameters of 6.3-8.3nm were synthesized in a cross-linked polyacrylamide (PAAm) hydrogel by coprecipitating iron ions. The decomposition of the magnetic polymer hydrogel by an aqueous solution of sodium hydroxide led to the transfer of Fe3O4 NPs into the aqueous medium. The NPs can be dispersed stably in water for more than three months. The Fe3O4 NPs were characterized by X-ray photoelectron spectra (XPS), X-ray powder diffraction (XRD), transmission electron microscope (TEM), and Fourier transform infrared spectroscopy (FT-IR). The saturation magn...

2011-01-01

10

Oxidation of polycaprolactone to induce compatibility with other degradable polyesters  

British Library Electronic Table of Contents (United Kingdom)

Chemical modification of poly(?-caprolactone) PCL by oxidation with potassium permanganate in solution was investigated. According to the data obtained from Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance 1H NMR, after the oxidation reactions the PCL chains exhibited new functional groups (vinyl and hydroxyl) and possible intermolecular recombination, producing an oxidized-polycaprolactone (PCL-OX). Solution viscometry indicated that degradation also occurred during the oxidation reactions (30% drop in viscosity average molecular weight was detected). Differential scanning calorimetry (DSC) also indicated that PCL was chemically modified and degraded. The successive self-nucleation/annealing (SSA) treatment confirmed that a reduction (or interruption) in line...

2007-01-01

11

The analysis of coupled heat and particle transport in Tokamaks by means of Fourier transform  

Energy Technology Data Exchange (ETDEWEB)

A method to deduce the 2 x 2 transport matrix for coupled heat and particle transport in Tokamaks is proposed. The method applies to perturbative experiments, and is based on a Fourier transform of the measured signals of temperature and density. By analyzing different linear combinations of temperature and density, the eigenvectors and eigenvalues of the transport matrix are determined. The method is tested for a number of illustrative cases using simulated data, and the sensitivity to noise on the signals is evaluated. (author).

1992-04-01

12

Quantum Discrete Fourier Transform in an Ion Trap System  

International Nuclear Information System (INIS)

We propose two schemes for the implementation of quantum discrete Fourier transform in the ion trap system. In each scheme we design a tunable two-qubit phase gate as the main ingredient. The experimental implementation of the schemes would be an important step toward complex quantum computation in the ion trap system.

2007-06-15

13

Cesium ion desorption ionization with Fourier transform mass spectrometry  

International Nuclear Information System (INIS)

Cesium ions (Cs"+) are used for the production of the feed ions necessary to obtain Fourier transform mass spectra (FTMS). The molecule chosen for the initial study of this Cs"+ desorption ionization (DI-FTMS) was vitamin B-12 because of its nonvolatile, thermally labile character. 21 references.

14

Optimal oscillation-center transformations  

Energy Technology Data Exchange (ETDEWEB)

A variational principle is proposed for defining that canonical transformation, continuously connected with the identity transformation, which minimizes the residual, coordinate-dependent part of the new Hamiltonian. The principle is based on minimization of the mean-square generalized force. The transformation reduces to the action-angle transformation in that part of the phase space of an integrable system where the orbit topology is that of the unperturbed system, or on primary KAM surfaces. General arguments in favor of this definition are given, based on Galilean invariance, decay of the Fourier spectrum, and its ability to include external fields or inhomogeneous systems. The optimal oscillation-center transformation for the physical pendulum, or particle in a sinusoidal potential, is constructed.

1984-08-01

15

Computational Complexity of Cyclotomic Fast Fourier Transforms over Characteristic-2 Fields  

CERN Document Server

Cyclotomic fast Fourier transforms (CFFTs) are efficient implementations of discrete Fourier transforms over finite fields, which have widespread applications in cryptography and error control codes. They are of great interest because of their low multiplicative and overall complexities. However, their advantages are shown by inspection in the literature, and there is no asymptotic computational complexity analysis for CFFTs. Their high additive complexity also incurs difficulties in hardware implementations. In this paper, we derive the bounds for the multiplicative and additive complexities of CFFTs, respectively. Our results confirm that CFFTs have the smallest multiplicative complexities among all known algorithms while their additive complexities render them asymptotically suboptimal. However, CFFTs remain valuable as they have the smallest overall complexities for most practical lengths. Our ...

2011-01-01

16

Fourier Transform Infrared Imaging and MR Microscopy Studies Detect Compositional and Structural Changes in Cartilage in a Rabbit Model of Osteoarthritis  

UK PubMed Central (United Kingdom)

Assessment of subtle changes in the primary macromolecular components of cartilage, proteoglycan (PG) and collagen, is critical for the diagnosis of early stages of osteoarthritis (OA), but...Full Text Available

2007-03-01

17

Bone Quality determined by Fourier Transform Infrared Imaging Analysis in Mild Primary Hyperparathyroidism  

UK PubMed Central (United Kingdom)

Context: Mild primary hyperparathyroidism (PHPT) is characterized by asymptomatic hypercalcemia, most commonly in the absence of classical signs and symptoms. Hence, there is need to characterize...Full Text Available

2008-09-01

18

Use of real-time Fourier Transform Infrared Reflectivity as an in situ monitor of YBCO film growth and processing  

CERN Document Server

Fourier Transform Infrared (FTIR) spectroscopy has been utilized during high rate E-beam evaporation/deposition of YBa2Cu3O7 (YBCO). The results demonstrate the great utility of FTIR as an in situ monitor of YBCO deposition and processing. We detect different (amorphous/fine polycrystalline) insulating pre-existing phases to the high Tc superconducting phase which appear to have distinct reflectivity fingerprints dominated by thin film interference effects, as a function of temperature and oxygen pressure. These fingerprints reveal some of the kinetic and thermodynamic pathways during the growth of YBCO.

2007-01-01

19

A quantitative method to detect explosives and selected semivolatiles in soil samples by Fourier transform infrared spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a novel Fourier transform infrared (FTIR) spectroscopic method that can be used to rapidly screen soil samples from potentially hazardous waste sites. Samples are heated in a thermal desorption unit and the resultant vapors are collected and analyzed in a long-path gas cell mounted in a FTIR. Laboratory analysis of a soil sample by FTIR takes approximately 10 minutes. This method has been developed to identify and quantify microgram concentrations of explosives in soil samples and is directly applicable to the detection of selected volatile organics, semivolatile organics, and pesticides.

1995-06-01

20

Novel non-discoid chiral copper(II)-salen type [N2O2] donor Schiff base complexes with a cyclohexane diamine spacer: synthesis, electrochemistry, columnar mesomorphism and DFT study  

British Library Electronic Table of Contents (United Kingdom)

A series of new non-discoid chiral copper(ii)-salen type complexes, [Cu((4-CnH2n+1O)2salen)], n = 14, 16, 18 and salen = N,N'-cyclohexane bis (salicylideneiminato), containing 4-substituted alkoxy tails in the side aromatic rings and a cyclohexane spacer, have been prepared and their mesogenic properties investigated. The compounds were characterised by Fourier transform infra-red spectroscopy, 1H and 13C nuclear magnetic resonance spectroscopy, UV-vis spectroscopy and fast atom bombardment mass spectrometry. Mesomorphic properties of these compounds were studied by polarising optical microscopy, differential scanning calorimetry and X-ray diffraction (XRD). The ligands are non-mesogenic but the complexes exhibited enantiotropic rectangular columnar mesophases (Colr) with extended temperat...

2011-01-01

21

Characterization and reactivity of Fe3O4/FeMnOx core/shell nanoparticles for methylene blue discoloration with H2O2  

British Library Electronic Table of Contents (United Kingdom)

A magnetic core/shell Fe3O4/FeMnOx catalyst was prepared by a simple oxidation-precipitation method. The catalyst was characterized by X-ray diffraction, transmission electron microscope, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and cyclic voltammetry. The characterization studies verified that Fe3O4 core was coated with a layer of Fe-Mn oxide. The Fe3O4/FeMnOx was found to be an effective and stable heterogeneous catalyst for the discoloration of methylene blue (MB) in aqueous solution by H2O2. The high catalytic activity is due to the FeMnOx shell, which not only increased the surface hydroxyl groups, but also enhanced the interfacial electron transfer. The discoloration of MB could be due to the decomposition of H2O2 into ?OH ...

2011-01-01

22

Application of spectroscopic techniques for the study of paper documents: A survey  

International Nuclear Information System (INIS)

For many centuries paper was the main material for recording cultural achievements all over the world. Paper is mostly made from cellulose with small amounts of organic and inorganic additives, which allow its identification and characterization and may also contribute to its degradation. Prior to 1850, paper was made entirely from rags, using hemp, flax and cotton fibres. After this period, due to the enormous increase in demand, wood pulp began to be commonly used as raw material, resulting in rapid degradation of paper. Spectroscopic techniques represent one of the most powerful tools to investigate the constituents of paper documents in order to establish its identification and its state of degradation. This review describes the application of selected spectroscopic techniques used for paper characterization and conservation. The spectroscopic techniques that have been used and will be reviewed include: Fourier-Transform Infrared spectroscopy, Raman ...

2009-06-01

23

Calorimetric and spectroscopic studies of the polymorphic phase behavior of a homologous series of n-saturated 1,2-diacyl phosphatidylethanolamines.  

UK PubMed Central (United Kingdom)

The polymorphic phase behavior of a homologous series of n-saturated 1,2-diacyl phosphatidylethanolamines was investigated by differential scanning calorimetry, 31P-nuclear magnetic resonance, and Fourier...Full Text Available

1993-04-01

24

Vibrations of circular cylindrical shells  

Science.gov (United States)

An exact solution method for the free vibration problem of thin circular cylindrical shells is presented. The differential equations of motion are solved directly with the use of simple Fourier series as the modal displacement functions. Stokes' transformation is exploited to obtain correct series expressions for the derivatives of the Fourier series. From this method an explicit expression of the exact frequency equation can be obtained for any kind of boundary conditions. The accuracy of the present method is checked against available data. The proposed method is then used to find the modal characteristics of the thermal liner of the Fast Test Reactor (FTR). The numerical results obtained are compared with finite element method solutions. (auth)

1975-07-01

25

Surface analysis by Fourier-transform infrared (FTIR) spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

A diffuse-reflectance capability for the Fourier transform infrared spectrometer at the Y-12 Plant Laboratory has been implemented. A sample cell with a 25 to 400/sup 0/C temperature-controlled sample stage and an ultrahigh-vacuum-to-atmospheric pressure gas-handling capability has been developed. Absorbance of light from the spectrometer beam, resulting from the beam being scattered from a powder sample, can be measured. This capability of detecting molecular species on and in powders is to be used to study chemisorption on actinide and rare-earth metals, alloys, and compounds. Cell design is described along with experiments demonstrating its performance in detecting moisture absorption on uranium oxide, moisture and carbon dioxide absorption on the lithium hydride/hydroxide system, and carbon dioxide absorption on potassium borohydride. 13 figures.

1981-08-12

26

Monitoring amino acids, organic acids, and ripening changes in Cheddar cheese using Fourier-transform infrared spectroscopy  

British Library Electronic Table of Contents (United Kingdom)

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

2011-01-01

27

Fourier transform IR studies on the interaction of selected chemicals with isolated cuticles  

International Nuclear Information System (INIS)

It is known that the plant cuticle represents the first barrier that must be overcome by any chemical reaching the plant surface from the atmosphere before entering the plant. Because of the importance of the cuticle as a barrier to penetration of a wide variety of compounds, its morphology, chemistry, and permeability have been extensively studied. However, only limited information is available on the nature of functional chemical groups present and their interaction and role during the penetration process. The usefulness of in situ Fourier transform infrared spectroscopy studies in identifying functional groups present in isolated cuticles is described and their relationships to the structure of the cuticular membrane are discussed. Applications of infrared spectroscopy on the presence and role of phenolics in the cuticle structure and during the cuticle development, nitrogen oxide binding to isolated cuticles, and the interactions between ...

28

Electron Capture Dissociation Implementation Progress in Fourier Transform Ion Cyclotron Resonance Mass Spectrometry  

British Library Electronic Table of Contents (United Kingdom)

Successful electron capture dissociation (ECD) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) applications to peptide and protein structural analysis have been enabled by constant progress in implementation of improved electron injection techniques. The rate of ECD product ion formation has been increased to match the liquid chromatography and capillary electrophoresis timescales, and ECD has been combined with infrared multiphoton dissociation in a single experimental configuration to provide simultaneous irradiation, fast switching between the two techniques, and good spatial overlap between ion, photon, and electron beams. Here we begin by describing advantages and disadvantages of the various existing electron injection techniques for ECD in FT-ICR MS. We next ...

2008-01-01

29

Algebraic Topology Foundations of Supersymmetry and Symmetry Breaking in Quantum Field Theory and Quantum Gravity: A Review  

CERN Document Server

A novel algebraic topology approach to supersymmetry (SUSY) and symmetry breaking in quantum field and quantum gravity theories is presented with a view to developing a wide range of physical applications. These include: controlled nuclear fusion and other nuclear reaction studies in quantum chromodynamics, nonlinear physics at high energy densities, dynamic Jahn-Teller effects, superfluidity, high temperature superconductors, multiple scattering by molecular systems, molecular or atomic paracrystal structures, nanomaterials, ferromagnetism in glassy materials, spin glasses, quantum phase transitions and supergravity. This approach requires a unified conceptual framework that utilizes extended symmetries and quantum groupoid, algebroid and functorial representations of non-Abelian higher dimensional structures pertinent to quantized spacetime topology and state space geometry of quantum operator algebras. Fourier transforms, generalized ...

2009-01-01

30

Magnetic domains in martensite of Ni-Mg-Ga alloy  

International Nuclear Information System (INIS)

The structural changes attendant on intermartensitic transformation in a Ni-Mg-Ga shape memory alloy are considered using magneto-optical visualization with the help of ferrite-garnet monocrystalline films. It is established that on the intermartensitic transformation the complete reorganization of martensite macrostructure fails. Martensite crystals resulted from the basic transformation change somewhat their sizes on intermartensitic transition. The existence of large-scale labyrinth magnetic domain structure is revealed

2006-05-01

31

Ferrihydrite phase transformation in the presence of aqueous sulfide and supercritical CO2  

British Library Electronic Table of Contents (United Kingdom)

The transformation of ferrihydrite to siderite (FeCO3) in the presence of supercritical CO2 (scCO2) and aqueous sulfide has been investigated by in situ attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and ex situ X-ray diffraction (XRD). The chemical transformation of iron-bearing minerals to form iron carbonates may play a role in the chemistry related to the geological sequestration of carbon dioxide in the Earth's (sub)surface. The iron oxyhydroxide ferrihydrite in an aqueous solution containing sodium sulfide in contact with scCO2 at 100^oC reacts within 24h to form siderite and elemental sulfur. In situ studies of this reaction with ATR-FTIR show that ferrihydrite exists with an adsorbed layer of carbonate. However, the presence of the carbonate adsorbat...

2010-01-01

32

Direct conversion of fusion energy into the electric one in the 'Dragon' magnetic confinement system  

International Nuclear Information System (INIS)

It is shown that recuperator in which the thermal energy of particles is transformed into electric oue under drift in crossed fields is naturally coupled with dragontype magnetic confinement system, so the recuperation process can be initiated in the dragon magnetic field. A number of questions occuring under analysis of recuperator-dragon system is considered, including the dynamics of particle transfer to the recuperator, the share of particles entering the recuperator, the effect of rotational transform and the recuperation efficiency.

33

Longitudinal and transverse mode evolution in free electron laser  

Energy Technology Data Exchange (ETDEWEB)

We use the method of Padg approximants and Fourier transform techniques to treat analytically the problem of transverse and longitudinal mode evolution in FELs. We obtain simple relations providing a transparent understanding of the dynamic of pulse propagation effects and of transverse mode guiding. We discuss the interplay with inhomogeneous broadening effects and derive gain formulae including longitudinal and transverse mode couplings.

1995-12-31

34

Discrete phase retrieval in musical structures  

British Library Electronic Table of Contents (United Kingdom)

This paper describes phase-retrieval approaches in music by focusing on the particular case of the cyclic groups (beltway problem). After presenting some old and new results on phase retrieval, we introduce the extended phase retrieval for a generalized musical Z-relation. This concept is accompanied by mathematical definitions and motivations from computer-aided composition. We assume from the reader basic knowledge of groups, topological groups, group algebras, group actions, Lebesgue integration, convolution products, and Fourier transform.

2011-01-01

35

Dielectric barrier discharge using corona-modified silicone rubber  

Science.gov (United States)

Results from scanning electron microscopy, Fourier transform infrared spectroscopy and the measurement of thermally stimulated current show that a high density of the physical defects and the chemical defects are introduced into the surface of the silicone rubber plates after they are treated by corona discharge plasma. These defects behave electrically as shallow electron traps, leading to the formation of a uniform discharge in air at higher pressure when the corona-modified silicone rubber is used in dielectric barrier discharge.

2008-10-01

36

Absolute absorption of ozone in the midinfrared  

Energy Technology Data Exchange (ETDEWEB)

The absolute absorption of ozone in the midinfrared has been measured relative to 253.7-nm ultraviolet absorption to an accuracy of 1% using a Bruker Fourier transform spectrometer. These new results agree with previous measurements by diode laser measurements after the latter are corrected for more recent infrared calculations and ultraviolet cross sections. They also agree with a determination based on refractive index measurements in the infrared. 16 refs., 4 figs., 3 tabs.

1992-12-20

37

Radiation testing of organic ion exchange resins  

International Nuclear Information System (INIS)

A number of ion exchange materials are being evaluated as part of the Tank Waste Remediation System (TWRS) Pacific Northwest Laboratory (PNL) Pretreatment Project for the removal of "1"3"7Cs from aqueous tank wastes. Two of these materials are organic resins; a phenol-formaldehyde resin (Duolite CS-100) produced by Rohm and Haas Co. (Philadelphia, Pennsylvania) and a resorcinol-formaldehyde (RF) resin produced by Boulder Scientific Co. (Mead, Colorado). One of the key parameters in the assessment of the organic based ion exchange materials is its useful lifetime in the radioactive and chemical environment that will be encountered during waste processing. The focus of the work presented in this report is the radiation stability of the CS-100 and the RF resins. The scope of the testing included one test with a sample of the CS-100 resin and testing of two batches of the RF resin (BSC-187 and BSC-210). Samples of the exchangers were irradiated with a "6"0Co source to a total absorbed dose ...

1983-04-11

38

Radiation testing of organic ion exchange resins  

Energy Technology Data Exchange (ETDEWEB)

A number of ion exchange materials are being evaluated as part of the Tank Waste Remediation System (TWRS) Pacific Northwest Laboratory (PNL) Pretreatment Project for the removal of {sup 137}Cs from aqueous tank wastes. Two of these materials are organic resins; a phenol-formaldehyde resin (Duolite CS-100) produced by Rohm and Haas Co. (Philadelphia, Pennsylvania) and a resorcinol-formaldehyde (RF) resin produced by Boulder Scientific Co. (Mead, Colorado). One of the key parameters in the assessment of the organic based ion exchange materials is its useful lifetime in the radioactive and chemical environment that will be encountered during waste processing. The focus of the work presented in this report is the radiation stability of the CS-100 and the RF resins. The scope of the testing included one test with a sample of the CS-100 resin and testing of two batches of the RF resin (BSC-187 and BSC-210). Samples of the exchangers were irradiated with a {sup 60}Co source to a total ...

1995-09-01

39

The optimization of gamma spectra processing in prompt gamma neutron activation analysis (PGNAA)  

International Nuclear Information System (INIS)

The uncertainty of the elemental analysis is one of the major factors governing the utility of on-line Prompt Gamma Neutron Activation Analysis (PGNAA) in the blending and sorting of bulk materials. In this paper, a general method applicable to Gamma spectra processing is presented and applied to PGNAA in mineral industry. Based on the Fourier transform of spectra and their de-correlation in the Fourier space (the improvement of the conditioning of the correlation matrix), processing of overlapping of characteristic peaks minimizes the propagation of random errors, which optimizes the accuracy and decreases the detection limits of elemental analyses. In comparison with classical methods based on the linear combinations of relevant regions of spectra the improvement may be considerable, especially when several elements are interfering. The method is applied to four case stories covering both borehole logging and on-line ...

2009-04-15

40

Structure analysis of cation selective Cr-goethite as protective rust of weathering steel  

International Nuclear Information System (INIS)

We have performed extended X-ray absorption fine structure (EXAFS) analysis for artificial Cr-goethite to elucidate the local structure around Cr in Cr-goethite. The spectra were obtained using synchrotron radiation X-rays at the Photon Factory in Tsukuba. The first shell contributions were isolated by Fourier filtering EXAFS data, and the inverse Fourier transformed single-shell data were analyzed using a curve fitting method. The results show that Cr is coordinated with (7#+-#1)O"2"- ions. The protective characteristics of the Cr-goethite protective rust layer on weathering steel can be interpreted in terms of the O"2"- coordination around Cr"3"+ resulting in the creation of negative fixed charge in the Cr-goethite particles. (author)

2005-02-01

41

Phase Information and the Evolution of Cosmological Density Perturbations  

CERN Document Server

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

2000-01-01

42

The accurate magnetic structure of CeAl{sub 2} at various temperatures in the ordered state  

Energy Technology Data Exchange (ETDEWEB)

The magnetic structure of the cubic compound CeAl{sub 2} is incommensurate and double-k. The moments on the two Ce sites describe two elliptical helices of opposed chiralities and lie in the (11-bar0) plane, with their Fourier components m{sup k} close to the [111] direction. Recent symmetry considerations, including for the first time the inversion center of the crystal, have reduced the number of parameters of this structure and have underlined the existence of a phase difference between the projections m{sub x}{sup k}, m{sub y}{sup k} and m{sub z}{sup k} of m{sup k}. Up to now, although many neutron investigations have been carried out on CeAl{sub 2} single crystals, no set of magnetic intensities was available which was large and good enough to check whether this phase difference exists or not. We have measured such a set of data, taking great care of the instrumental resolution in order to avoid unwanted contributions ...

2008-04-02

43

The accurate magnetic structure of CeAl_2 at various temperatures in the ordered state  

International Nuclear Information System (INIS)

The magnetic structure of the cubic compound CeAl_2 is incommensurate and double-k. The moments on the two Ce sites describe two elliptical helices of opposed chiralities and lie in the (11-bar0) plane, with their Fourier components m"k close to the [111] direction. Recent symmetry considerations, including for the first time the inversion center of the crystal, have reduced the number of parameters of this structure and have underlined the existence of a phase difference between the projections m_x"k, m_y"k and m_z"k of m"k. Up to now, although many neutron investigations have been carried out on CeAl_2 single crystals, no set of magnetic intensities was available which was large and good enough to check whether this phase difference exists or not. We have measured such a set of data, taking great care of the instrumental resolution in order to avoid unwanted contributions to the intensities from other domains. As the ...

2008-04-02

44

Impacts of amorphous metal-based transformers on energy efficiency and environment  

International Nuclear Information System (INIS)

Magnetic properties of a recently developed Fe-based amorphous alloy with a high saturation induction of 1.65 T are reviewed. The increased saturation induction is fully utilized in transformers with reduced magnetic losses, physical sizes and audible noises, minimizing some of the drawbacks of amorphous metal-based transformers based on a currently available amorphous alloy. Impacts of this on the worldwide energy savings and reduction of greenhouse gas emissions are discussed. A recent effort in achieving a saturation induction beyond 1.65 T in nanocrystalline alloys is mentioned.

2008-10-01

45

Predicting neuronal responses during natural vision.  

Science.gov (United States)

A model that fully describes the response properties of visual neurons must be able to predict their activity during natural vision. While many models have been proposed for the visual system, few have ever been tested against this criterion. To address this issue, we have developed a general framework for fitting and validating nonlinear models of visual neurons using natural visual stimuli. Our approach derives from linear spatiotemporal receptive field (STRF) analysis, which has frequently been used to study the visual system. However, prior to the linear filtering stage typical of STRFs, a linearizing transformation is applied to the stimulus to account for nonlinear response properties. We used this approach to compare two models for neurons in primary visual cortex: a nonlinear Fourier power model, which accounts for spatial phase invariant tuning, and a traditional linear model. We characterized prediction accuracy in terms of the total ...

46

Time-resolved Fourier transform emission spectroscopy of A2P-X2+ infrared transition of the CN radical  

British Library Electronic Table of Contents (United Kingdom)

The A2P-X2+Dv=-3 bands of the 12C14N radical have been observed by time-resolved Fourier transform spectroscopy in the 1850-3100cm-1 region with a wavenumber resolution of 0.025cm-1. The radical was produced in a pulsed positive column discharge in a cyanogene and helium mixture. Seven bands of v=0-3, 1-4, 2-5, 3-6, 4-7, 5-8, and 6-9 were analyzed to give the molecular constants of each state by least-squares fitting of 801 lines. The pulsed discharge was found to be efficient for production of CN in the excited A2P state. The vibrational excitation temperature was determined to be 6680+-835K and 6757+-534K for the A2P and X2+ states, respectively. The population of the A2P was found to be 4% of that of the X2+ state in the time after turning off the discharge.

2008-01-01

47

Real Paley-Wiener theorems and local spectral radius formulas  

CERN Document Server

We systematically develop real Paley-Wiener theory for the Fourier transform on R^d for Schwartz functions, L^p-functions and distributions, in an elementary treatment based on the inversion theorem. As an application, we show how versions of classical Paley-Wiener theorems can be derived from the real ones via an approach which does not involve domain shifting and which may be put to good use for other transforms of Fourier type as well. An explanation is also given why the easily applied classical Paley-Wiener theorems are unlikely to be able to yield information about the support of a function or distribution which is more precise than giving its convex hull, whereas real Paley-Wiener theorems can be used to reconstruct the support precisely, albeit at the cost of combinatorial complexity. We indicate a possible application of real Paley-Wiener theory to partial differential equations in this vein ...

2008-01-01

48

Matrix-assisted laser desorption fourier transform mass spectrometry for biological compounds  

Science.gov (United States)

The recent development of matrix-assisted UV laser desorption (LD) mass spectrometry has made possible the ionization and detection of extremely large molecules (with molecular weights exceeding 100,000 Daltons). This technique has generated enormous interest in the biological community for the direct examination of large peptides and oligonucleotides. Although this matrix-assisted ionization method has been developed and used almost exclusively with time-of-flight (TOF) mass spectrometers, research is currently in progress to demonstrate this technique with trapped ion mass spectrometers, such as Fourier transform ion cyclotron resonance mass spectrometry (FTMS). The potential capabilities of FTMS for wide mass range, high resolution measurement, and ion trapping experiments suggest that this instrumental technique should be useful for the detailed structural characterization of large ions generated by the matrix-assisted technique. We have ...

1990-01-01

49

Identification of protein phosphorylation sites within Ser/Thr-rich cluster domains using site-directed mutagenesis and hybrid linear quadrupole ion trap Fourier transform ion cyclotron resonance mass spectrometry  

British Library Electronic Table of Contents (United Kingdom)

We describe a method for the analysis of multi-site phosphorylation in serine/threonine (Ser/Thr)-rich protein sequences. Site-specific mutagenesis was used to introduce tryptic cleavage sites in the serine glutamine/threonine glutamine cluster domain (SCD) of the human checkpoint protein kinase (Chk2). The mutant proteins were shown to autophosphorylate on residues that are inducibly phosphorylated when mammalian cells are exposed to ionizing radiation (serine 33/35, serine 516, threonine 68 and threonine 432). Five Ser/Thr clusters within the SCD were flanked by arginine or lysine residues to produce tryptic peptides for nanospray liquid chromatography (nanoLC)/linear quadrupole ion trap Fourier transform ion cyclotron resonance mass spectrometry. Phosphorylation sites were assigned usin...

2007-01-01

50

Fluctuation properties of strength function phenomena: A model study  

Energy Technology Data Exchange (ETDEWEB)

We study fluctuation properties of strength function phenomena by employing a quantum mechanical model where a single parent state couples with a large number of background states. The background system is devised in such a way that the classical dynamics of the system may show a regular, an irregular, or a chaotic character as a function of a single parameter. The coupling of the parent state to the background states produces a fragmentation of the parent state, giving rise to a strength function phenomenon. We study various measures of the strength function that characterize its bulk structure or fluctuation properties. They include energy moments, strength distribution, fractal dimensions of the strength function, and Fourier transform of the autocorrelation function. Some of these measures, such as strength distribution or Fourier transform of the autocorrelation function, reflect characteristic ...

1997-07-01

51

Analysis of S-adenosylmethionine and related sulfur metabolites in bacterial isolates of Pseudomonas aeruginosa (BAA-47) by liquid chromatography/electrospray ionization coupled to a hybrid linear quadrupole ion trap and Fourier transform ion cyclotron resonance mass spectrometry  

British Library Electronic Table of Contents (United Kingdom)

A comprehensive and highly selective method for detecting in bacterial supernatants a modified sulfur nucleoside, S-adenosyl-L-methionine (SAM), and its metabolites, i.e., S-adenosylhomocysteine (SAH), adenosine (Ado), 5prime-deoxy-5prime-methylthioadenosine (MTA), adenine (Ade), S-adenosyl-methioninamine (dcSAM), homocysteine (Hcy) and methionine (Met), was developed. The method is based on reversed-phase liquid chromatography with positive electrospray ionization (ESI+) coupled to a hybrid linear quadrupole ion trap (LTQ) and 7-T Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS). A gradient elution was employed with a binary solvent of 0.05 M ammonium formate at pH 4 and acetonitrile. The assay involves a simultaneous cleanup of cell-free bacterial broths by solid-pha...

2009-01-01

52

Acidic and neutral polar NSO compounds in Smackover oils of different thermal maturity revealed by electrospray high field Fourier transform ion cyclotron resonance mass spectrometry  

Energy Technology Data Exchange (ETDEWEB)

Negative ion electrospray ionization (ESI) coupled with high field Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) allows for the direct detection of acidic NSO compounds in petroleum. The technique requires no chromatographic separation, is able to distinguish 18 different compound classes (e.g., neutral nitrogen, carboxylic acids and oxygenates), and can identify {approx}14,000 distinct masses by ultra-high mass resolution and mass accuracy. We previously studied three crude oils from different geological origins [Organic Geochemistry 33 (2002b) 743-759]. Here, we expand our research by comparing two source-equivalent Smackover oils of different levels of thermal maturity. We observe clear differences in the distribution of NSO compound classes, types (number of rings plus double bonds within a class), and number of alkyl carbons. With increasing thermal stress, the relative amount of sulfur and oxygen containing ...

2004-07-01

53

Vibrational spectroscopy of silica sol-gel components during microwave irradiation  

Energy Technology Data Exchange (ETDEWEB)

In order to study the effects of microwaves on chemical reactions equipment was designed to acquire in-situ vibrational spectra of sol-gel components as they are irradiated with microwaves. Fourier Transform Infrared (FTIR) and Raman spectroscopy were used. A low temperature (10K) FTIR cell was used to trap samples in an argon matrix at 10{sup -7} Torr. For the liquid samples no differences were seen in spectra of irradiated and nonirradiated samples, but the argon matrix isolation technique showed dramatic differences.

1995-12-31

54

Synthesis and characterization of Rosebengal/folicacid-functionalized multiwall carbon nanotubes  

British Library Electronic Table of Contents (United Kingdom)

Multiwall carbon nanotubes (MWCNTs) were functionalized with a photosensitizer, rosebengal (RB), and folicacid (FA), an anti-cancer drug simultaneously and individually, which was characterized with various analytical instruments like Fourier Transform Iinfrared (FTIR) spectroscopy, UV?Vis spectroscopy, Thermogravimetric analysis (TGA), Photoluminescence (PL) spectroscopy, X-ray photoelectron spectroscopy (XPS), and Transmission electron microscopy (TEM). FTIR spectra confirmed the chemical modification of MWCNT. The chemical functionalization of MWCNT with RB was further supported by UV?Vis and PL spectra.

2011-01-01

55

State-of-the-art technique for power system stabilizer tuning  

Energy Technology Data Exchange (ETDEWEB)

Power System Stabilizers (PSS) have broad application throughout the world. PSS application requires careful tuning which is usually accomplished in the field with the generator and power system in an abnormal condition. Recently developed equipment which combines fast Fourier transform capability with digital computer technique provides a means of PSS tuning which is faster and more accurate than was previously obtainable. This paper describes a PSS tuning test conducted using the new technique. The advantages will be apparent to the reader. The described test is very poignant as evidenced by two unexpected occurrences of instability.

1983-03-01

56

Interpretation of EXAFS data from laser shock compressed plasmas  

Energy Technology Data Exchange (ETDEWEB)

Measurements on laser shock compressed aluminium using the EXAFS (Extended X-ray Absorption Fine Structure) technique on the Al K-edge are described. Two methods of analysis of this data were used for the determination of density: the standard EXAFS technique using Fourier transforms and curve fitting, and a method based on a bandstructure calculation of the absorption spectra as a function of compression. These two techniques give results which are in fairly good agreement with each other and also with a hydrodynamic simulation of the experiment. The ion correlation parameter is estimated and shows that two-sided laser irradiation of aluminium foils produces a dense plasma which is strongly coupled. (author).

1989-01-01

57

Discrete simulation of power law noise  

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.

2011-01-01

58

Decontamination of the chemical warfare agent simulant dimethyl methylphosphonate by means of large-area low-temperature atmospheric pressure plasma  

British Library Electronic Table of Contents (United Kingdom)

Dimethyl methylphosphonate (DMMP), a chemical simulant of the nerve gas GB, was decontaminated with a nonthermal atmospheric pressure plasma. The decontamination efficiency was measured qualitatively by means of Fourier transform spectroscopy and quantitatively by means of gas chromatography. With helium gas only, 10g/m2 of DMMP on an aluminum surface was 99.9% decontaminated in 2min, furthermore, with the addition of 5% of oxygen gas, it was 99.99% decontaminated in 10min. Given the low input power (<100W) and temperature (<75degreeC), this plasma is eligible for nondestructive decontamination of almost all material surfaces.

2009-01-01

59

Intensification of harmonic spontaneous radiation with a novel undulator  

International Nuclear Information System (INIS)

We have calculated the on-axis spectrum of spontaneous radiation emitted by an electron moving along a planar undulator that has a magnetic profile along the axis that approximates a square wave. (This could be obtained in practice by driving a ferromagnetic undulator into saturation by excessivecurrent in the windings.) We find considerable enhancement of the harmonic radiation spectrum. We compare the harmonic power emitted by an electron moving through an undulator having a sine-wave field profile with the radiation emitted from an undulator having a square-wave profile; the latter is approximated by the first three Fourier components of the undulator magnetic field profile along the axial direction. Examples are computed for 40MeV electrons taking K1 is greatly enhanced for the approximate square-wave magnetic profile: the ratio of the power emitted at f=5 by the square-wave undulator to that of the ...

1999-07-01

60

Intensification of Harmonic Spontaneous Radiation with a Novel Undulator  

Science.gov (United States)

We have calculated the on-axis spectrum of spontaneous radiation emitted by an electron moving along a planar undulator that has a magnetic profile along the axis that approximates a square wave. (This could be obtained in practice by driving a ferromagnetic undulator into saturation by excessive current in the windings.) We find considerable enhancement of the harmonic radiation spectrum. We compare the harmonic power emitted by an electron moving through an undulator having a sine-wave field profile with the radiation emitted from an undulator having a square-wave profile; the latter is approximated by the first three Fourier components of the undulator magnetic field profile along the axial direction. Examples are computed for 40MeV electrons taking K < 1, for spontaneous radiation emitted along the axis of the system. The emission at harmonics f > 1 is greatly enhanced for the approximate square-wave ...

1998-11-01

61

The Advanced Loose Parts Monitoring System (ALPS) and wavelet analysis  

International Nuclear Information System (INIS)

The Advanced Loose Parts monitoring System (ALPS), is installed in each Unit of Paks NPP. Its characteristics and some interesting results are presented. Wavelet analysis is being introduced to data evaluation techniques. The short-time Fourier transform and the continuous wavelet transform techniques have been used to present the time signal in a time-frequency and time-scale plane. Characteristic frequencies of the physical acoustic system and the growing frequencies of spectrum components during the start-up of the main coolant pumps are clearly seen on those pictures. The newly applied wavelet coherence promises to find new oscillation in the pair of signals, which remain hidden in time-dependent autospectra. (author)

62

Partition Functions of Normal Factor Graphs  

CERN Document Server

One of the most common types of functions in mathematics, physics, and engineering is a sum of products, sometimes called a partition function. After "normalization," a sum of products has a natural graphical representation, called a normal factor graph (NFG), in which vertices represent factors, edges represent internal variables, and half-edges represent the external variables of the partition function. In physics, so-called trace diagrams share similar features. We believe that the conceptual framework of representing sums of products as partition functions of NFGs is an important and intuitive paradigm that, surprisingly, does not seem to have been introduced explicitly in the previous factor graph literature. Of particular interest are NFG modifications that leave the partition function invariant. A simple subclass of such NFG modifications offers a unifying view of the Fourier transform, tree-based reparameterization, loop calculus, and ...

2011-01-01

63

High-mode-number ballooning modes in a heliotron/torsatron system: 1, Local magnetic shear  

Energy Technology Data Exchange (ETDEWEB)

The characteristics of the local magnetic shear, a quantity associated with high-mode-number ballooning mode stability, are considered in heliotron/torsatron devices that have a large Shafranov shift. The local magnetic shear is shown to vanish even in the stellarator-like region in which the global magnetic shear is positive. The reason for this is that the degree of the local compression of the poloidal magnetic field on the outer side of the torus, which maintains the toroidal force balance, is reduced in the stellarator-like region of global magnetic shear because the global rotational transform in heliotron/torsatron systems is a radially increasing function. This vanishing of the local magnetic shear is a universal property in heliotron/torsatron systems with a large Shafranov shift since it results from toroidal force balance in the ...

1996-05-01

64

Design of modular coils for a quasi-axisymmetric stellarator with a flexible control of the magnetic field configuration  

Energy Technology Data Exchange (ETDEWEB)

A design of the modular coil system for CHS-qa has been made for the plasma configuration '2b32' with the aspect ratio 3.2. The magnetic field strength and the major radius are 1.5 T and 1.5 m, respectively. The normal component of magnetic field produced by the modular coils is minimized on the plasma boundary to obtain the optimum coil design. We put engineering constraint on the distance between adjacent modular coils and the radius of coil curvature. The dependence of the residual normal component of the field on these conditions is examined, and the realistic values for them are selected. Additional coils to control various properties of the magnetic field configuration (the rotational transform, the magnetic well depth, etc.) have been designed and a flexibility of the magnetic field configuration is realized. For the case that the ...

2002-08-01

65

Characteristic Of Induction Magnetic Field On The Laboratory Scale Superconducting Fault Current Limiter Circuit  

International Nuclear Information System (INIS)

Model construction of the laboratory scale superconducting fault current limiter circuit (SFCL) has been performed. The SFCL is fault current limiter and used as electric network security. It mainly consists of a copper coil, a superconducting ring and an iron core that are concentrically arranged. The SFCL circuit is essentially a transformer where the secondary windings are being replaced by the ring of YBa_2Cu_3O_7_-_x superconductor (HTS). The ring has critical transition temperature Tc = 92 K and critical current Ic = 3.61 A. Characterization of the SFCL circuit is simulated by ANSYS version 5.4 software. The SFCL circuit consists of load and transformer impedances. The results show that the inductions of magnet field flux in the iron core of primer windings and ring disappear to one other before fault state. It means that impedance of the transformer is zero. After the condition a ...

2004-06-01

66

Amorphous to crystalline phase transformation in Metglas reg-sign studied by Moessbauer spectroscopy  

International Nuclear Information System (INIS)

The authors present differential scanning calorimetry (DSC) and in situ Moessbauer spectroscopy results for Metglas ribbons, to which different heat treatments were made. The Curie temperature of the amorphous phase is determined and the evolution of the magnetic field of this phase is studied as a function of temperature

1997-12-01

67

Long-term reliability of amorphous alloy wound core distribution transformers  

Energy Technology Data Exchange (ETDEWEB)

In order to verify long-term reliability of amorphous alloy wound core distribution transformers, accelerated aging tests and field trials used by actual transformers were practiced. As for accelerated aging tests, short-circuit tests were added to imitate mechanical stress in operation on a utility's distribution system. As a result, even after the equivalent of 30 years, which was the normal expected transformer's life, magnetic characteristic was unchanged, so these transformers could be operated. Also, about field trials, two hundred transformers of four kinds were installed on a utility's distribution system to look into no-load characteristics. They were equipped with a mechanism to measure load current, background vibration and lightning surge current, so the influence for magnetic characteristic could be ...

1994-01-01

68

Fourier Analysis on GL(n,R)  

UK PubMed Central (United Kingdom)

Two problems of Fourier analysis on GL(n,R) are studied. The first concerns the decomposition of the additive Fourier operator in terms of the group representation...Full Text Available

1970-01-01

69

Combined effect of magnetic field and heat absorption on unsteady free convection and heat transfer flow in a micropolar fluid past a semi-infinite moving plate with viscous dissipation using element free Galerkin method  

British Library Electronic Table of Contents (United Kingdom)

The fully developed electrically conducting micropolar fluid flow and heat transfer along a semi-infinite vertical porous moving plate is studied including the effect of viscous heating and in the presence of a magnetic field applied transversely to the direction of the flow. The Darcy-Brinkman-Forchheimer model which includes the effects of boundary and inertia forces is employed. The differential equations governing the problem have been transformed by a similarity transformation into a system of non-dimensional differential equations which are solved numerically by element free Galerkin method. Profiles for velocity, microrotation and temperature are presented for a wide range of plate velocity, viscosity ratio, Darcy number, Forchhimer number, magnetic field parameter, heat absorption ...

2010-01-01

70

Electromagnetic fields - introduction to relevant issues  

International Nuclear Information System (INIS)

This introductory paper surveys potential sources of electric magnetic, and electro-magnetic fields. Various cases are discussed to exemplify the total frequency range: nuclear magnetic resonance tomography, high-voltage transmission lines, transformer stations, effect lighting balls, military transmitters, transmitter towers of the Postal Services and other operators, mobile radiotelephone equipment, large broadcasting transmitters, radar radiation, high-frequency heat therapy. There is evidence suggesting that electric, magnetic and electro-magnetic fields may possibly represent a certain nuisance or health hazard even at field strength occuring in equipment used for every-day-life purposes, with an emphasis on their possible actions and effects in children and adolescents. The author discusses, in conclusion, the aerial equipment ordinance issued by Lower ...

1993-06-01

71

Seven years of operating experience with amorphous metal transformers  

Energy Technology Data Exchange (ETDEWEB)

Amorphous metals have an atomic structure resembling that of glass, and have high strength, toughness, and excellent magnetic properties for transformer applications. This type of metal has the potential to reduce the core losses of electromagnetic apparatus by 70-75% compared to the best grain-oriented silicon iron currently used. If all 4 million distribution transformers now in service in Canada were replaced by the more efficient amorphous units, it is estimated that over 5.25 billion kWh of energy could be saved annually. The experience of the General Electric (GE) Company and other researchers with operation of amorphous transformers is described. GE first tried operating amorphous metal transformers on a utility distribution system in April 1982. The shell-type cruciform design showed stable, low-loss performance over eight years of service. GE and the Electric Power Research ...

1991-05-01

72

Direct observation of ordered orbital of YTiO_3 by the X-ray magnetic diffraction technique  

International Nuclear Information System (INIS)

X-ray magnetic diffraction (XMD) technique was applied to an orbital ordering compound of ferromagnetic YTiO_3 for the first time. The orbital-magnetic form factor #mu# _L(k) and the spin-magnetic form factor #mu# _S(k) were independently measured by utilizing the LS separation ability of the XMD. The #mu# _L(k) was measured for ten reciprocal-lattice points. No significant values of the #mu# _L(k) were observed for most of the reciprocal-lattice points within the estimated statistical errors, which suggested quenching of the orbital moment. The #mu# _S(k) was measured for 22 reciprocal-lattice points. Fourier synthesis of the #mu# _S(k) gave the spin density distribution m _S(r) in the real space. The obtained m _S(r) map shows the characteristic feature of the electron distribution of 3d electron in the t_2_g state of a Ti atom coordinated by O"2"- ions, in which the electrons are distributed away ...

2005-08-01

73

Thermal and mechanical properties of poly(vinyl alcohol) plasticized with glycerol  

British Library Electronic Table of Contents (United Kingdom)

Abstract Thermomechanical behavior of membranes based on blends of poly(vinyl alcohol) (PVA) with different weight percentage (wt %) of glycerol has been studied. Solid-state PVA/Glycerol polymer membranes were prepared by a solution casting method. The films were studied for thermal characteristics by differential scanning calorimetry (DSC) and thermogravimetric analysis and for the mechanical properties including hardness and modulus by nanoindentation method. The dispersion of glycerol within the polymer matrix was examined using scanning electron microscopy. Fourier transform infrared spectroscopy was used to confirm the formation of hydrogen bonding between the plasticizer and PVA in their blends and also to provide information on compatibility and physical interactions between the gl...

2011-01-01

74

Synthesis and characterization of Co-Ag core-shell nanoparticles  

Energy Technology Data Exchange (ETDEWEB)

A micellar method has been used to prepare silver-coated cobalt (Co-Ag) nanoparticles. The synthesized particles have been deeply characterized by several methods, i.e., XRD, UV-Vis, TEM, XPS, and electrochemical techniques. There is every indication that the obtained particles show a truly core-shell structure. All the nanoparticles obtained under different conditions are in the size range 3-5 nm. High-resolution TEM (HRTEM), Fast Fourier Transformation (FFT), and Selected Area Electron Diffraction (SAED) indicated that the presence of hcp-Co and fcc-Ag, in which cobalt is located in the central area; meanwhile silver is at the edges of the nanoparticle. The absorption band of the Co-Ag colloid shifts to a longer wavelength and broadens relative to that of pure silver colloid. Voltammetric characterization allowed to determine the coverage of the cobalt core.

2010-08-15

75

Submegahertz linewidth at 240 GHz from an injection-locked free-electron laser  

International Nuclear Information System (INIS)

Radiation from an ultrastable 240 GHz solid state source has been injected, through an isolator, into the cavity of the University of California, Santa Barbara millimeter-wave free-electron laser (FEL). High-power FEL emission, normally distributed among many of the cavity's longitudinal modes, is concentrated into the single mode to which the solid state source has been tuned. The linewidth of the FEL emission is 0.5 MHz, consistent with the Fourier transform limit for the 2 #mu#s pulses. This demonstration of frequency-stable, ultranarrow-band FEL emission is a critical milestone on the road to FEL-based pulsed electron paramagnetic resonance spectroscopy.

2007-10-22

76

Soluble starch?based biodegradable and microporous microspheres as potential adsorbent for stabilization and controlled release of coix seed oil  

British Library Electronic Table of Contents (United Kingdom)

Soluble starch?based biodegradable and microporous microspheres (SDM-Ms) were prepared by emulsion chemical cross-linking technique using trisodium trimetaphosphate (TSTP) as the cross-linker. The resultant amorphous SDM-Ms were excellently identified by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The internal rupture and surface-controlled erosion were the predominant degradation mechanisms for SDM-Ms. The obtained SDM-Ms were applied to adsorb coix seed oil (CSO) by immersing method. The adsorption capacity of CSO within SDM-Ms was determined, namely 0.5238?g/g, and the thermal stability was shown higher than that of the free CSO. A burst release appeared in the second hour, followed by controlled release. Diffusion, d...

2011-01-01

77

Removal of polycyclic aromatic hydrocarbons from aqueous solution using plant residue materials as a biosorbent  

British Library Electronic Table of Contents (United Kingdom)

To elucidate biosorption mechanism and removal efficiency of plant residues as a biosorbent to abate polycyclic aromatic hydrocarbons (PAHs) in wastewater, sorption of PAHs onto wood chips (WC), ryegrass roots (RR), orange peels (OP), bamboo leaves (BL), and pine needles (PN) were investigated. The structural characterization of the biosorbents was analyzed by elemental composition, BET-N2 surface area, and Fourier transform infrared spectroscopy. PAHs sorption to the selected biosorbents were compared and correlated with their structures. Biosorption isotherms fit well with Freundlich equation and the mechanism was dominated by partition process. The magnitude of phenanthrene partition coefficients (Kd) followed the order of PN>BL>OP>RR>WC, ranged from 2484+/-24.24 to 5306+/-92.49L/kg. Ex...

2011-01-01

78

Preparation and characterization of nano hydroxyapatite/polymeric composites materials. Part I  

British Library Electronic Table of Contents (United Kingdom)

The present study is focused on preparation of nano composite materials and the effect of citric acid on their different properties. The formation of nano HA and its interaction with chitosan (C), gelatin (G) polymers and citric acid (CA) materials were studied. The Fourier Transformed Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), transmission electron microscope (TEM), and scanning electron microscope (SEM) were used to characterize these composite materials. The compressive strength (CS) was also measured to know the reinforcement of the prepared composites. The results show that carboxylic and amino groups play crucial role for HA formation on chitosan-gelatin polymeric matrix in the presence of citric acid (CA). The formation of nano HA part...

2011-01-01

79

Preparation and Characterization of a Novel Polyamide Charged Mosaic Membrane  

British Library Electronic Table of Contents (United Kingdom)

A novel composite charged mosaic membrane (CCMM) was prepared via interfacial polymerization (IP) of polyamine [poly(epichlorohydrin amine)] and trimesoyl chloride (TMC) on the polyethersulfone (PES) support. Fourier transform infrared spectroscopy (FT-IR), environmental scanning electron microscopy (ESEM), atomic force microscopy (AFM) and water contact angle analysis were applied to characterize the resulted CCMM. The FT-IR spectrum indicates that TMC reacts sufficiently with polyamine. ESEM and AFM pictures show that the IP process produces a dense selective layer on the support membrane. The water contact angle of the CCMM is smaller than that of the substrate membrane because of the cross-linked hydrophilic polyamine network. Several factors affecting the IP reaction and the performan...

2010-01-01

80

Polyester and multiwalled carbon nanotube composites: characterization, electrical conductivity and antibacterial activity  

British Library Electronic Table of Contents (United Kingdom)

Abstract Poly(butylene terephthalate) (PBT) composites containing multiwalled carbon nanotubes (MWCNTs) were prepared using a melt-blending process and used to examine the effects on the composite structure and properties of replacing PBT with acrylic acid-grafted PBT (PBT-g-AA). PBT-g-AA and multihydroxyl-functionalized MWCNTs (MWCNTs-OH) were used to improve the compatibility and dispersibility of the MWCNTs within the PBT matrix. The composites were characterized morphologically using transmission electron microscopy, and chemically using Fourier transform infrared, solid-state 13C NMR and UV-visible absorption spectroscopy. The antibacterial and electrical conductivity properties of the composites were also evaluated. MWCNTs or MWCNTs-OH enhanced the antibacterial activity and electric...

2011-01-01

81

PLZT spatial light modulator for a 1-D hologram memory.  

Science.gov (United States)

A 100-bit slitlike aperture array spatial light modulator has been developed using 8.8/65/35 PLZT for a high-bit-density 1-D hologram memory. The most desirable characteristics, such as distortion-free diffraction-limited Fourier transform patterns and good uniformity of displayed bit patterns over 100 bits, have been realized. The lowest SNR was 86, and rise time and fall time have been 30 microsec and 8 microsec, respectively, at 190-V halfwave voltage. One-dimensional holographic storage experiments have been successfully performed using this PLZT spatial light modulator. PMID:20216813

1980-01-01

82

Normalized noise power spectrum of full field digital mammography detector system  

International Nuclear Information System (INIS)

Full text: A method to measure noise power spectrum of a full field digital mammography system is presented. The effect of X-ray radiation dose, size and configuration of region of interest on normalized noise power spectrum (NNPS) was investigated. Flat field images were acquired using RQA-M2 beam quality technique (Mo/Mo anode-filter, 28 kV, 2 mm Al) with different clinical radiation doses. The images were cropped at about 4 cm from the edge of the breast wall and then divided into different size of non-overlapping or overlapping segments. NNPS was determined through de trending, 2-D fast Fourier transformation and normalization. Our measurement shows that high radiation dose gave lower NNPS at a specific beam quality. (author)

83

Normalized Noise Power Spectrum of Full Field Digital Mammography System  

International Nuclear Information System (INIS)

A method to measure noise power spectrum of a full field digital mammography system is presented. The effect of X-ray radiation dose, size and configuration of region of interest on normalized noise power spectrum (NNPS) was investigated. Flat field images were acquired using RQA-M2 beam quality technique (Mo/Mo anode-filter, 28 kV, 2 mm Al) with different clinical radiation doses. The images were cropped at about 4 cm from the edge of the breast wall and then divided into different size of non-overlapping or overlapping segments. NNPS was determined through detrending, 2-D fast Fourier transformation and normalization. Our measurement shows that high radiation dose gave lower NNPS at a specific beam quality.

2010-01-05

84

Multi walled carbon nanotubes/epilson polylysine nanocomposite with enhanced antibacterial activity  

British Library Electronic Table of Contents (United Kingdom)

Abstract Aims: To develop a new nano composite of multi walled carbon nanotubes (MWNTs) with enhanced antimicrobial activity. Methods and Results: A novel antimicrobial nanocomposite [MWNT epilson polylysine (MEPs)] was synthesized via covalent attachment of epilson polylysine on MWNTs with hexamethylene diisocyanate (HDI) as the coupling agent. UV visible spectra and Fourier transform infrared spectra (FT IR) investigations indicate that MEPs is stable, with epilson polylysine leaching effectively eliminated. When compared to MWNTs, the new nano composite MEPs exhibits enhanced antimicrobial activities. In 20 mg l 1 suspensions, significant increases of 72 1, 64 5 and 69% against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus can be observed. The deposited film of MEPs...

2011-01-01

85

Morphology, structure, and conductivity of polypyrrole prepared in the presence of mixed surfactants in aqueous solutions  

British Library Electronic Table of Contents (United Kingdom)

Polypyrrole (PPy) was prepared from different mixed-surfactant solutions with ammonium persulfate as an oxidant. Three types of combinations were selected, including cationic/anionic, cationic/nonionic, and anionic/nonionic mixed-surfactant solutions. The surfactants used in the experiments included cetyltrimethylammonium bromide (cationic surfactant), sodium dodecyl sulfate (anionic surfactant), sodium dodecyl sulfonic acid salt (anionic surfactant), poly(vinyl pyrrolidone) (nonionic surfactant), and poly(ethylene glycol) (nonionic surfactant). The morphology, structure, and conductivity of the resulting PPy were investigated in detail with scanning electron microscopy, Fourier transform infrared spectra, and the typical four-probe method, respectively. The results showed that the interac...

2007-01-01

86

Molecular structure of platinum(III) hydroxoacetates according to data from EXAFS spectra  

Energy Technology Data Exchange (ETDEWEB)

The EXAFS spectra of the platinum(III) complexes Pt/sub 4/(OAc)/sub 10/(OH)/sub 2/ (I) and Pt/sub 4/ (OAc)/sub 4/(OH)/sub 8/(H/sub 2/O)/sub 2/ (II) have been investigated. It has been found by a curve-fitting method and with the aid of Fourier transformations that the shortest Pt-Pt distances are 2.61 A in complex I and 2.36 and 2.6 A in II. The values of the bond lengths obtained are consistent with the molecular structures proposed for complexes I and II, which contain skeletons of four platinum atoms in the form of a square or a rectangle, as well as with the known literature data on the lengths of Pt-Pt bonds in Pt(III) complexes.

1986-04-01

87

Mode shape and natural frequency identification for seismic analysis from background vibration  

International Nuclear Information System (INIS)

Background vibration in a CANDU plant can be used to determine the dynamic characteristics of major items of equipment, such as calandria, the fuelling machines and the primary heat transport pumps. These dynamic characteristics can then be used to verify the seismic response of the equipment which, at present, is based on theoretical models only. The feasibility and basic theory of this new approach (which uses accelerations measured at several points on a structure and does not require knowledge of the source of excitation) was established in Phase I of the study. This report is based on Phase II in which the methods of analysis developed in Phase I were improved and verified experimentally. A Fast Fourier Transform (FFT) algorithm was incorporated and an interactive curve fitting technique was developed to obtain the dynamic characteristics in the form of natural frequencies, mode shapes and damping ratios. The method is now available for ...

1984-02-06

88

Miscibility enhancement of PP/PBT blends with a side-chain liquid crystalline ionomer  

British Library Electronic Table of Contents (United Kingdom)

Side-chain liquid crystalline ionomer (SLCI) containing sulfonic acid groups with a polymethylhydrosiloxane main-chain was used in the blends of polypropylene (PP) and polybutylene terephthalate (PBT) as a compatibilizer. The crystalline behavior, morphological, and mechanical properties of the blends were investigated in detail by differential scanning calorimetry (DSC), polarizing optical microscope (POM), Fourier transforms infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Revealed by the shift of Tm in DSC thermogram and the shift of the absorbed peak in FTIR spectra, specific interaction led to stronger interfacial adhesion between these phases, which resulted in much finer dispersion of the minor PBT phase in PP matrix. The SLCI containing sulfonate acid groups ac...

2009-01-01

89

Layered double hydroxide as novel antibacterial drug delivery system  

British Library Electronic Table of Contents (United Kingdom)

The cephalosporin class antibacterial agent, cefazolin, was intercalated into layered double hydroxides (LDHs) in order to improve the drug efficiency as well as to achieve the controlled release property. Cefazolin molecules were incorporated into LDH through conventional ion exchange reaction. X-ray diffraction pattern analyses confirmed that cefazolin molecules were intercalated between the interlayer spaces of LDH. Fourier-transform infrared spectra and high performance liquid chromatographs clearly showed that the drug molecules were stabilized in LDH lattice through electrostatic interaction and released without any changes in their chemical integrity. Antibacterial activity of the cefazolin-LDH nanohybrid was also examined by an in vitro test, such as the minimal inhibitory concentr...

2010-01-01

90

Kramers-Kronig Analysis of Infrared Reflectance Spectra for Quaternary In_xAl_yGa_1_-_x_-_yN Alloy  

International Nuclear Information System (INIS)

In this paper, a Kramers-Kronig (KK) analysis of infrared (IR) reflectance spectrum of quaternary In_0_._0_1Al_0_._0_6Ga_0_._9_3N film grown by molecular beam epitaxy (MBE) is reported. The infrared measurement is performed in the reflection mode at an incident angle of 15 degree sign by Fourier transform infrared (FTIR) spectroscopy at T = 300 K. The Kramers-Kronig analysis of the reflectivity data has been used to obtain the real and imaginary parts of the index of refraction (n and k), and the real and imaginary parts of the dielectric response function (#epsilon#' and #epsilon#') of the materials. Finally, the transverse optical and longitudinal optical phonons for quaternary In_xAl_yGa_1_-_x_-_yN were obtained.

2010-07-07

91

Impedance Noise Identification for State-of-Health Prognostics  

Energy Technology Data Exchange (ETDEWEB)

Impedance Noise Identification is an in-situ method of measuring battery impedance as a function of frequency using a random small signal noise excitation source. Through a series of auto- and cross-correlations and Fast Fourier Transforms, the battery complex impedance as a function of frequency can be determined. The results are similar to those measured under a lab-scale electrochemical impedance spectroscopy measurement. The lab-scale measurements have been shown to correlate well with resistance and power data that are typically used to ascertain the remaining life of a battery. To this end, the Impedance Noise Identification system is designed to acquire the same type of data as an on-board tool. A prototype system is now under development, and results are being compared to standardized measurement techniques such as electrochemical impedance spectroscopy. A brief description of the Impedance Noise Identification hardware system and ...

2008-07-01

92

Impact of different cultivation and induction regimes on the structure of cytosolic inclusion bodies of TEM1-b-lactamase  

British Library Electronic Table of Contents (United Kingdom)

The enzyme TEM1-b-lactamase has been used as a model to study the impact of different cultivation and induction regimes on the structure of cytosolic inclusion bodies (IBs). The protein has been heterologously expressed in Escherichia coli in fed-batch cultivations at different temperatures (30, 37, and 40degreeC) as well as induction regimes that guaranteed distinct product formation rates and ratios of soluble to aggregated protein. Additionally, shake flask cultivations at 20, 30, and 37degreeC were performed. IBs were sampled during the whole bioprocess and structural analysis was performed by attenuated total reflectance Fourier transform infrared (ATR-FT-IR) spectroscopy. This work clearly demonstrates that the tested production regimes and rates had no impact on the IB structure, wh...

2008-01-01

93

High-throughput proteomics of breast carcinoma cells: a focus on FTICR-MS  

Energy Technology Data Exchange (ETDEWEB)

Discovery of better biomarkers for diagnosis, prognosis, and therapy-response prediction is the most critical task of a scientific quest aimed at developing newly designed, tailor-made therapies for patients with cancer. Consequently, a proteome wide analysis, in addition to genomic studies, is an absolute requirement for a complete functional understanding of tumor biology. Ultra-sensitive, high-performance Fourier transform ion cyclotron resonance (FTICR) mass spectrometry (MS) currently holds an important role in fulfilling the demands of biomarker discovery. In this review, we describe the applicability of FTICR MS for breast cancer proteomics, particularly for the analysis of complex protein mixtures obtained from a limited number of cells typically available from clinical specimens.

2008-06-05

94

High channel density wavelength division multiplexer with defined diffracting means positioning  

Energy Technology Data Exchange (ETDEWEB)

A wavelength division multiplexer/demultiplexer having optical path lengths between a fiber array and a Fourier transform lens, and between a dispersion grating and the lens equal to the focal length of the lens. The optical path lengths reduce losses due to angular acceptance mismatch in the multiplexer. Close orientation of the fiber array about the optical axis and the use of a holographic dispersion grating reduces other losses in the system. Multi-exposure holographic dispersion gratings enable the multiplexer/demultiplexer for extremely broad-band simultaneous transmission and reflection operation. Individual Bragg plane sets recorded in the grating are dedicated to and operate efficiently on discrete wavelength ranges.

1990-01-01

95

Final report: technical contributions to the development of incipient fault detection/location instrumentation  

Energy Technology Data Exchange (ETDEWEB)

The transmission of electrical energy by use of underground cables is increasing. Fault location techniques have certain limitations; incipient fault detection and location would help reduce the maintenance cost of these lines as well as improve the reliability of service. The report discusses some test results related to RF-probing techniques applied to high-voltage transmission lines. The high-frequency losses and attenuation in high-voltage cables places certain ultimate limitations on RF-probing techniques for incipient fault detection. Time-domain reflectrometry methods were employed to assess the RF-transmission properties of high-voltage cables at frequencies as high as 6 GHz. Fast-Fourier-transform deconvolution was used to obtain loss measurements as a function of frequency. The loss mechanisms were identified. The measurement hardware and methods are discussed as well as analysis approach leading to the conclusions.

1986-04-01

96

Effect of #gamma#-irradiation on commercial polypropylene based mono and multi-layered retortable food packaging materials  

International Nuclear Information System (INIS)

Irradiation processing of food in the prepackaged form may affect chemical and physical properties of the plastic packaging materials. The effect of #gamma#-irradiation doses (2.5-10.0 kGy) on polypropylene (PP)-based retortable food packaging materials, were investigated using Fourier transform infrared (FTIR) spectroscopic analysis, which revealed the changes happening to these materials after irradiation. The mechanical properties decreased with irradiation while oxygen transmission rate (OTR) was not affected significantly. Colour measurement indicated that Nylon 6 containing multilayer films became yellowish after irradiation. Thermal characterization revealed the changes in percentage crystallinity.

2007-07-01

97

Comparative study on the technological properties of latex and natural rubber from Hancornia speciosa Gomes and Hevea brasiliensis  

British Library Electronic Table of Contents (United Kingdom)

This work reports a systematic comparative study of the technological properties of natural lattices and rubbers extracted from Hancornia speciosa Gomes and Hevea brasiliensis [(Willd. ex Adr. de Juss.) Muell.-Arg.] (clone RRIM 600) trees from 11 collections in Brazil throughout 2004. Natural rubber latex particle sizes and distributions were quite similar with an average diameter around 1 mm. Molecular weight, Wallace plasticity, and Mooney viscosity values were approximately the same for both rubbers. Fourier transform infrared spectroscopy peaks characteristic of natural rubber were observed for both Hancornia and Hevea. The measured differences in technological properties included lower values for Hancornia dry rubber content, % ash, % nitrogen, and plasticity retention index but highe...

2009-01-01

98

Chemistry between crosslinks affects the properties of peptide hydrogels  

British Library Electronic Table of Contents (United Kingdom)

Protein hydrogels were prepared by substituting ovalbumin with different concentrations of ethyl vinyl sulfone (EVS) or acrylic acid (AA) and crosslinking with divinyl sulfone (DVS). Fourier transform-infrared (FT-IR) spectroscopic studies confirmed the addition of EVS, AA, and DVS onto the protein. Swelling was assessed as a function of pH in the range of 2.5 to 9.4 and ionic strength. The elastic modulus of the gels was determined in shear and compression. Stress relaxation was assessed in compression. The substituent highly affected swelling and modulus with both hydrogels displaying non-Gaussian behavior in the range of hydrogel environments studied. Acrylic acid substituted ovalbumin exhibited a decreasing modulus with increasing swelling behaving as a polyelectrolyte with low added s...

2011-01-01

99

Chemical and morphological characterization of mesoporous material supported copper oxide nanoparticles for potential application  

British Library Electronic Table of Contents (United Kingdom)

SBA-15 supported nano-scaled copper oxide was synthesized by impregnation method via ultrasonic-assisted route. The removal test from gas mixture containing 0.1?vol.% hydrogen sulfide was carried out over this material at atmospheric conditions. The effects of the chemical nature of copper oxide and the textural properties of the material on removal capacity were studied. The materials before and after the removal test were analyzed by nitrogen adsorption, X-ray diffraction, Transmission Electron Microscope, X-ray photoelectron Spectroscopy, Fourier Transform Infrared Spectrometer and Inductive Coupled Plasma. The results showed that copper species are located predominantly in mesopore channels, existing as copper oxide nanoparticles. Mesopores are active sites for removal reaction. The ou...

2011-01-01

100

Biosorption of reactive dye by waste biomass of Nostoc linckia  

British Library Electronic Table of Contents (United Kingdom)

Potential of spent biomass of a cyanobacterium, Nostoc linckia HA 46, from a hydrogen bioreactor was studied for biosorption of a textile dye, reactive red 198. The waste biomass was immobilized in calcium alginate and used for biosorption of the dye from aqueous solution using response surface methodology (RSM). Kinetics of the dye in aqueous solution was studied in batch mode. Interactive effects of initial dye concentration (100-500mg/L), pH (2-6) and temperature (25-45^oC) on dye removal were examined using Box-Behnken design. Maximum adsorption capacity of the immobilized biomass was 93.5mg/g at pH 2.0, initial concentration of 100mg/L and 35^oC temperature, when 94% of the dye was removed. Fourier transform infrared (FT-IR) studies revealed that biosorption was mainly mediated by fun...

2011-01-01

101

Banana peel extract mediated novel route for the synthesis of palladium nanoparticles  

British Library Electronic Table of Contents (United Kingdom)

Bio-inspired palladium nanoparticles were synthesized by using banana peel extract (BPE), a non-toxic eco-friendly material. Boiled, crushed, acetone precipitated, air-dried peel powder was used to reduce palladium chloride. The palladium nanoparticles were characterized by using UV-Visible spectroscopy, scanning electron microscope-energy dispersive spectra (SEM-EDS) and X-ray diffraction (XRD) analysis. Dynamic light scattering (DLS) studies revealed the average size of nanoparticles to be 50nm. Fourier transform infra red spectroscopy (FTIR) implicated the role of carboxyl, amine and hydroxyl groups in the synthetic process. This paper thus describes a novel green method for the synthesis of palladium nanoparticles.

2010-01-01

102

Ising model for phase separation in alloys with anisotropic elastic interaction. 2: A computer experiment  

Energy Technology Data Exchange (ETDEWEB)

When a metallic alloy is quenched into a miscibility gap, a mixture of two phases develops, whose domain structure then coarsens because of the interfacial energy between the two phases. This spatial arrangement of the domains and the rate at which they evolve may be strongly influenced by elastic interactions. In a recent paper, the authors described a method for simulating the effect of anisotropic elastic interactions in a two-dimensional Ising model of a cubic alloy, using Kawasaki dynamics with the elastic interactions represented by a long-range two-body interaction potential. Here they present the results of such simulations at various temperatures, alloy compositions and misfits (by misfit they mean the difference in size between the two kinds of atom), exhibiting snapshots both of the microscopic configurations (corresponding to experimental measurements using transmission electron microscopy) and of their squared Fourier transforms ...

1996-08-01

103

CZT vs FFT: Flexibility vs Speed  

Energy Technology Data Exchange (ETDEWEB)

Bluestein's Fast Fourier Transform (FFT), commonly called the Chirp-Z Transform (CZT), is a little-known algorithm that offers engineers a high-resolution FFT combined with the ability to specify bandwidth. In the field of digital signal processing, engineers are always challenged to detect tones, frequencies, signatures, or some telltale sign that signifies a condition that must be indicated, ignored, or controlled. One of these challenges is to detect specific frequencies, for instance when looking for tones from telephones or detecting 60-Hz noise on power lines. The Goertzel algorithm described in Embedded Systems Programming, September 2002, offered a powerful tool toward finding specific frequencies faster than the FFT.Another challenge involves analyzing a range of frequencies, such as recording frequency response measurements, matching voice patterns, or displaying spectrum information on the face of an ...

2003-10-01

104

Magnetic-field-induced phase transitions in Wigner molecules  

Energy Technology Data Exchange (ETDEWEB)

A theoretical analysis of formation and symmetry transformations is presented for Wigner molecules with N = 2,..., 20 electrons confined in quantum dots at high magnetic fields. Using the unrestricted Hartree-Fock method with the multicentre Gaussian basis, we have found that Wigner molecules with N {>=} 6 abruptly change their shape and symmetry with an associated jump in the first derivative of the ground-state energy, i.e. they undergo phase transitions. In particular, the phases of the Wigner molecules obtained just after emerging from the maximum-density droplet (MDD) phase possess a different symmetry from that formed at a high magnetic field. We show that the properties of the electron-electron interaction energy demonstrate very well both the breakdown of the MDD and the quasi-classical character of the Wigner molecule in the high magnetic field. Possible mechanisms of the MDD decay are ...

2003-06-25

105

A classical model for the magnetic field-induced Wigner crystallization in quantum dots  

Energy Technology Data Exchange (ETDEWEB)

A classical model is presented for magnetic field-induced Wigner crystallization in electron systems confined within two-dimensional quantum dots. In contrast to other classical models, this one does not treat an electron as a point charge; the electron density is assumed to take a Gaussian form corresponding to the lowest Landau level. Using a Monte Carlo method we have determined the equilibrium configurations as functions of the magnetic field. We have found a classical counterpart of the quantum maximum density droplet (MDD) and studied the breakdown of the MDD into a Wigner molecule as well as the transformations of the Wigner molecule shape induced by the external magnetic field. The phase diagram for the classical Wigner molecules has been presented and its qualitative agreement with previous quantum mechanical calculations has been shown.

2004-03-03

106

Experimental determination of line strengths for selected carbon monoxide and carbon dioxide absorption lines at temperatures between 295 and 1250 K  

Energy Technology Data Exchange (ETDEWEB)

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

1994-11-01

107

Experimental determination of line strengths for selected carbon monoxide and carbon dioxide absorption lines at temperatures between 295 and 1250 K  

International Nuclear Information System (INIS)

Fourier transform infrared absorption spectroscopy has been used for the determination of the line strengths of 41 CO and CO_2 absorption lines at temperatures between 295 and 1250 K. The CO vibrational-rotational lines were from the P branch of the fundamental absorption band (2150--1950 cm"-"1) while the CO_2 vibrational-rotational lines were from the far wing of the R branch of the #nu#_3 fundamental band (2395--2380 cm"-"1). The intensities of the lines were measured from absorption spectra recorded in a high-temperature gas cell containing known concentrations of CO/CO_2/N_2 gas mixtures at atmospheric pressure. Absorption spectra were recorded through the cell with the use of a moderate-resolution Fourier transform infrared spectrometer. The absorption spectra were mathematically corrected for distortions resulting from the finite resolution of the spectrometer and for peak overlap. Line strength ...

108

A numerical solution of unsteady MHD convection heat and mass transfer past a semi-infinite vertical porous moving plate using element free Galerkin method  

British Library Electronic Table of Contents (United Kingdom)

In this paper, the unsteady MHD free convection heat and mass transfer of viscous fluid flowing through a Darcian porous regime adjacent to a moving vertical semi-infinite plate under Soret and Dufour effect have been examined. Viscous dissipation effects are included in the energy equation. A uniform magnetic field is applied transversely to the direction of the flow. The differential equations governing the problem have been transformed by a similarity transformation into a system of non-dimensional differential equations which are solved numerically by element free Galerkin method. The influence of Grashof number (Gr), magnetic parameter (M), heat absorption parameter (Q), permeability parameter (K), Schmidt number (Sc), Soret number (Sr), and Dufour number (Du) on the velocity, tempera...

2010-01-01

109

On the electrodynamics of tachyons  

International Nuclear Information System (INIS)

Electrodynamic properties of processes involving charged tachyons are considered in connection with the real superluminal Lorentz transformations. These transformations are interpreted without making use of a tachon corridor and so that the interaction of tachyons from subluminal sources with ordinary matter is Lorentz invariant. Transformations of the electromagnetic fields are deduced from the extended principle of relativity. They are necessary in order to obtain the field equations that are satisfied by fields obeying Maxwell equations relative to superluminal inertial frames with respect to subluminal inertial frames. The field equations allow one to get the dependence of the field energy density and its current on the field strengths. The resulting equations are applied in a discussion of plane electromegnetic waves, sent out by a superluminal source. The obtained electrodynamics allows the existence of charged tatric ...

110

A simple route to a tunable electromagnetic gateway  

CERN Document Server

Transformation optics is used to design a gateway that can block electromagnetic waves but allows the passage of other entities. Our conceptual device has the advantage that it can be realized with simple materials and structural parameters and can have a reasonably wide bandwidth. In particular, we show that our system can be implemented by using a magnetic photonic crystal structure that employs a square ray of ferrite rods, and as the field response of ferrites can be tuned by external magnetic fields, we end up with an electromagnetic gateway that can be open or shut using external fields. The functionality is also robust against the positional disorder of the rods that made up the photonic crystal.

2009-01-01

111

Properties of A-15 Superconductors with Defects  

Science.gov (United States)

It is suggested that the large reduction of the superconducting transition temperature Tc due to defects observed experimentally in some A-15 compounds is caused by smearing of a high peak in the density of states at the Fermi level. The influence of defects on other physical properties (the magnetic susceptibility ?, the elastic modulus Cs, the structural transformation temperature Tm and the electrical resistivity ?) is also discussed from the same point of view. We expect the anomalous temperature dependence of ?, Cs and ? will be suppressed by defects.

1978-05-01

112

Radiation from Relativistic Strongly Magnetized Outflows  

CERN Document Server

Relativistic strongly magnetized winds outflowing from fast-rotating compact objects like millisecond pulsars with surface magnetic fields of $\\sim 10^{15}-10^{16}$ G are plausible sources of cosmological $\\gamma$-ray bursts. In such winds, there are at least three regions where extremely powerful X-ray and $\\gamma$-ray emission may be generated. The first radiating region is the wind photosphere that is at a distance of $\\sim 10^9$ cm from the compact object. The second radiating region is at a distance of $\\sim 10^{13}-10^{14}$ cm. In this region, the striped component of the wind field is transformed into large-amplitude electromagnetic waves. The third radiating region is at a distance of $\\sim 10^{16}-10^{17}$ cm, where deceleration of the wind due to its interaction with an ambient medium becomes important. Radiation from all these regions is considered.

1999-01-01

114

AUTOMATED TECHNOLOGY KNOWLEDGE BASE  

Science.gov (United States)

MAGNETIC FORMING .............. MAGNETIC INDUCTION ............ MAGNETIC MATERIALS ............ MAGNETIC MEASUREMENT .......... MAGNETIC PERMEABILITY . ...

115

3D Fourier synthesis of a new X-ray picture identical in projection to a previous picture  

Energy Technology Data Exchange (ETDEWEB)

A central problem in diagnostic radiology is to compare a new X-ray picture with a previous picture and from this comparison be able to decide if anatomical changes have occurred in the patient or not. It is of primary interest that these pictures are identical in projection. If not it is difficult to decide with confidence if differences between the pictures are due to anatomical changes or differences in their projection geometry. In this thesis we present a non invasive method that makes it possible to find the relative changes in the projection geometry between the exposure of a previous picture and a new picture. The method presented is based on the projection slice theorem (central section theorem). Instead of an elaborate search for a single new picture a pre-planned set of pictures are exposed from a circular orbit above the patient. By using 3D Fourier transform techniques we are able to synthesize a new X-ray picture from this set of ...

1993-11-01

116

X-ray scattering signatures of {beta}-thalassemia  

Energy Technology Data Exchange (ETDEWEB)

X-ray scattering from lyophilized proteins or protein-rich samples is characterized by the presence of two characteristic broad peaks at scattering angles equivalent to momentum transfer values of 0.27 and 0.6 nm{sup -1}, respectively. These peaks arise from the interference of coherently scattered photons. Once the conformation of a protein is changed, these two peaks reflect such change with considerable sensitivity. The present work examines the possibility of characterizing the most common cause of hemolytic anaemia in Egypt and many Mediterranean countries; {beta}-thalassemia, from its X-ray scattering profile. This disease emerges from a genetic defect causing reduced rate in the synthesis of one of the globin chains that make up hemoglobin. As a result, structurally abnormal hemoglobin molecules are formed. In order to detect such molecular disorder, hemoglobin samples of {beta}-thalassemia patients are collected, lyophilized and measured using a conventional X-ray ...

2009-08-11

117

Wind turbulence used as searching signal for MPPT in variable-speed wind energy conversion systems  

Energy Technology Data Exchange (ETDEWEB)

The control problem associated to a class of horizontal-axis fixed-pitch variable-speed low-power wind energy conversion systems, working in the partial load region, consisting in the energy conversion maximization, is approached here under the assumption that the wind turbine model and its parameters are poorly known. Using a new approach derived from the optimum seeking methods category, generically called Maximum Power Point Tracking (MPPT), the proposed control solution aims at driving the average position of the operating point near to optimality. Instead of inducing sinusoidal search signals, the wind turbulence is here used as search disturbance. The high-speed shaft's average rotational speed is slowly adjusted using the Fast Fourier Transform processing of some available measures from the system as an estimate of the operating point's position/distance to optimality. Numerical simulations are used for preliminary ...

2009-01-15

118

Vibrational spectroscopy of bacteriorhodopsin mutants: light-driven proton transport involves protonation changes of aspartic acid residues 85, 96, and 212  

Energy Technology Data Exchange (ETDEWEB)

Fourier transform infrared (FTIR) difference spectra have been obtained for the bR----K, bR----L, and bR----M photoreactions in bacteriorhodopsin mutants in which Asp residues 85, 96, 115, and 212 have been replaced by Asn and by Glu. Difference peaks that had previously been attributed to Asp COOH groups on the basis of isotopic labeling were absent or shifted in these mutants. In general, each COOH peak was affected strongly by mutation at only one of the four residues. Thus, it was possible to assign each peak tentatively to a particular Asp. From these assignments, a model for the proton-pumping mechanism of bR is derived, which features proton transfers among Asp-85, -96, and -212, the chromophore Schiff base, and other ionizable groups within the protein. The model can explain the observed COOH peaks in the FTIR difference spectra of bR photointermediates and could also account for other recent results on site-directed mutants of bR.

1988-11-15

119

Time-domain dynamic opto-rheology study of polymer films using step-scan FTIR time-resolved spectroscopy (S{sup 2}FTIR TRS)  

Energy Technology Data Exchange (ETDEWEB)

Step-scan Fourier transform infrared spectroscopy in conjunction with impulse stress on polymer films has been used to monitor dynamic rheological responses in real time. A novel piezo-electrically-driven polymer microrheometer was employed to apply repetitive impulses to the polymer sample while time-domain spectra were recorded. Recent results include the study of both semi-crystalline polymers such as isotactic polypropylene (iPP) and elastomers such as Estane polyester/polyurethane copolymer and Kraton tri-block copolymer. The spectral changes of iPP are consistent with frequency-domain results. For iPP at room temperature, large differences in the response times of different absorption bands are not seen. However, the orientation response of the CH{sub 3} rocking mode is slightly slower than the responses of the backbone modes. To the authors` knowledge, this is the first reported successful step-scan FTIR time-domain dynamic polymer ...

1998-07-01

120

Time-dependent infrared emission following photodissociation of nitromethane and chloropicrin.  

Science.gov (United States)

Nitromethane (CH(3)NO(2)) and its chlorinated analogue, chloropicrin (CCl(3)NO(2)), were photolyzed at 193, 248, and 266 nm, and the products were observed by time-dependent Fourier transform infrared emission spectroscopy. At 193 and 248 nm, the primary photodissociation pathway for nitromethane was cleavage of the C-N bond to produce CH(3) + NO(2)(A (2)B(2)). At 266 nm, weak emission was observed following photodissociation of nitromethane, but an infrared spectrum could not be obtained. The photodissociation of chloropicrin at 193 nm produced the analogous product channel CCl(3) + NO(2)(A (2)B(2)) in addition to several other product channels. At 248 and 266 nm, only CCl(3) + NO(2)(A (2)B(2)) was observed. The production of phosgene (CCl(2)O) from chloropicrin photodissociation was not observed in this study. PMID:16571044

2006-04-01

121

Thermal effect on superhydrophobic performance of stearic acid modified ZnO nanotowers  

Energy Technology Data Exchange (ETDEWEB)

The thermal desorption of stearic acid on superhydrophobic zinc oxide nanotowers has been investigated. The stearic acid passivated zinc oxide nanotowers provide a very high contact angle of {approx}173 {+-} 1.1 deg. with a very low hysteresis of {approx}1.4 {+-} 0.5 deg. due to the presence of a binary structure composed of several nanosteps on each nanotower of height {approx}700 nm that eventually reduces the area of contact between the drop and the nanotowers and trapping more air as revealed by the field emission scanning electron microscopy images. The superhydrophobic performance of these nanotowers, however, declines following annealing at elevated temperatures. Fourier transform infrared spectra show a reduction in the intensity of stearic acid -CH{sub n} peaks at elevated temperatures revealing the cause of the decrease in contact angle and confirming the occurrence of thermal desorption at 184 deg. C. The corresponding activation ...

2008-02-28

122

Temporal measures and controls in ultrafast laser domain; Mesures et controles temporels dans le domaine des lasers ultrabrefs  

Energy Technology Data Exchange (ETDEWEB)

This work presents the development of a streak camera 'jitter free' sweep unit synchronized on a femtosecond laser. This application of high voltage photoconductive switches ('High voltage Auston switch') yields subpicosecond resolution for accumulated images on streak camera on a few hundreds micro joule femtosecond laser. Two others applications of these photoconductive switches are studied: - ultrafast optical commutation by a Pockels cell directly driven by a photoconductive switch (rising edge < 100 ps and jitter < 2 ps), - laser pulse energy self-stabilization experimentally proving that driving a Pockels cell by a photoconductive switch can increase the stability of the laser pulse energy from 7 % to 0.7 % rms. Additionally, the application of the acoustic-optical programmable dispersive filter (Dazzler) to the self referenced spectral phase measurement is presented. As these measurements require a linear filter combined with a ...

2004-12-15

123

Synthesis of nanocrystalline YSZ (ZrO_2-8Y_2O_3) powder by polymerized complex method  

International Nuclear Information System (INIS)

In this study nanocrystalline powders of yttria-stabilized zirconia (ZrO_2-8Y_2O_3) have been synthesized through 'polymerized complex method'. Zirconium chloride, yttrium nitrate, citric acid and ethylene glycol were polymerized at 80 "oC to produce a gel-like mass in which metallic ions were uniformly distributed. During the thermal treatment of dried gel, nanocrystalline powder was formed at 450 "oC and 650 "oC for 2 h. Thermal reactions and crystalline phase formation of the dried gel were investigated through thermal analysis and X-ray diffraction analysis, respectively. The results of thermal analysis and XRD showed the formation of nanocrystalline powder at less than 600 "oC. Chemical bonding of the dried gel was investigated by Fourier transform infrared spectroscopy analysis. Morphology of powder calcined at 650 "oC was analyzed by scanning electron microscope. Yttria-stabilized zirconia powders with the mean crystallite size of 6 nm ...

2010-02-18

124

Study on performance of colloidal mixtures consisted of stearic acid and Na{sub 2}HPO{sub 4}.12H{sub 2}O for use as phase change materials of thermal energy storage  

Energy Technology Data Exchange (ETDEWEB)

The thermal energy storage performance and phase change stability of mix phase change materials consisted of stearic acid and Na{sub 2}PO{sub 4}.12H{sub 2}O are studied by means of Fourier transformation infrared spectrum analyses (FTIR) and Differential Scanning Calorimetry (DSC). The specific heat capacity of mix materials is also determined experimentally. The results show that all absorption peaks of functional groups and chemical bonds of stearic acid still exist, which suggests that these crystal materials composed of stearic acid and Na{sub 2}PO{sub 4}.12H{sub 2}O have good phase change stability and chemical compatibility. Thus, disadvantages caused by the subcooling of Na{sub 2}PO{sub 4}.H{sub 2}O and the low specific heat capacity of stearic acid can be solved, it is speculated that complement each other on the basis of organic/inorganic characteristics in itself is carried out for these two component materials of the mixture. ...

2010-07-15

125

Stearic acid gel derived MgTiO{sub 3} nanoparticles: A low temperature intermediate phase of Mg{sub 2}TiO{sub 4}  

Energy Technology Data Exchange (ETDEWEB)

Stearic acid gel is employed to study the phase evolution of MgTiO{sub 3} nanoparticles by thermal gravimetric analysis, X-ray diffraction, and Fourier transform infrared. During the preparation of stearic acid gel, tetrabutyl titanate easily absorbed moisture to hydrolyze into Ti(OH){sub 4} firstly, and then reacts with stearic acid and magnesium stearate to form magnesium-titanium oxide network polymer gel, meanwhile n-butanol is generated. When stearic acid gel is calcined in air, a series of oxidation and combustion reactions occur, meanwhile apparent heat is given off. The results show that a metastable intermediate phase Mg{sub 2}TiO{sub 4} is generated at 450 {sup o}C and nearly disappeared at 550 {sup o}C. Simultaneously, a new solid phase of MgTiO{sub 3} appears. The metastable intermediate phase Mg{sub 2}TiO{sub 4} is successfully identified in the current work.

2010-03-04

126

Size-dependent surface plasmon resonance in silver silica nanocomposites  

Energy Technology Data Exchange (ETDEWEB)

Silver silica nanocomposites were obtained by the sol-gel technique using tetraethyl orthosilicate (TEOS) and silver nitrate (AgNO{sub 3}) as precursors. The silver nitrate concentration was varied for obtaining composites with different nanoparticle sizes. The structural and microstructural properties were determined by x-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). X-ray photoelectron spectroscopic (XPS) studies were done for determining the chemical states of silver in the silica matrix. For the lowest AgNO{sub 3} concentration, monodispersed and spherical Ag crystallites, with an average diameter of 5 nm, were obtained. Grain growth and an increase in size distribution was observed for higher concentrations. The occurrence of surface plasmon resonance (SPR) bands and their evolution in the size range 5-10 nm is studied. For decreasing nanoparticle size, a redshift and ...

2008-02-20

127

Precise characterisation of nanochannels in track etched membranes by SAXS and SANS  

Energy Technology Data Exchange (ETDEWEB)

Poster session: Abstract is full text. Track membranes are thin polymer foils irradiated by heavy ions. The defects created by the heavy ions are located along the ions trajectory, the track. It is possible to open channels by etching with a chemical agent. These channels are very uniform. Small Angle Scattering (of X rays and neutrons) give global information about the characteristics of the channel shape. As the nanochannels are strictly parallel, an excellent sample orientation is required to obtain interpretable spectra. Then shoulders due to the oscillations of the Bessel function (radial part of the channel shape Fourier transform) are easily seen in the scattered intensity in the PXY data treatment software of SAS spectra allow to determine the channel diameter with its dispersion law, to demonstrate the existence of a wall thickness with a linearly varying density, and to assess the roughness. PXY can also detect non cylindric shapes ...

2003-05-01

128

Parameters determination of IEC-TDG by directly solving non-linear equation; Chokusetsuho ni yoru IEC-TDG hakei kaiseki  

Energy Technology Data Exchange (ETDEWEB)

An IEC-TDG waveform analysis program that can accurately calculate the waveform parameters in waveforms containing much noise as well as waveforms based on the IEC 1083-2 standard was developed in the impulse voltage and current test field. In the conventional curve fitting method, it is difficult to solve the non-linear equation directly when obtaining waveform parameters from the assigned discrete data. An approximate solution method is low in precision. Therefore, the residual between the standardized data and approximate function was calculated for high-speed Fourier transformation. Unrelated components were eliminated from the calculated frequency spectrum to synthesize waveforms. An L-M method is used for analysis. The solution is first tracked by a maximum diving method. If the convergence is judged to have been largely promoted, the method is switched into a Newton method to continue the calculation. The non-linear equation in a curve ...

1997-04-20

129

On-line analysis of chemical composition using an FT-Raman spectrometer in the near-ir  

Science.gov (United States)

Newly commercialized Fourier transform Raman spectroscopic instrumentation provides a simpler alternative for vibrational spectroscopic analysis. Instrument vendors currently design for laboratory use, but there are many potential process applications of these stable, easy to use instruments. Raman spectroscopy is highly suited to analysis of aqueous samples. Near infrared excitation minimized fluorescence interference and allows for remote operation via fiber optic probes. The Department of Energy has funded research at the Measurement and Control Center to establish the utility of this method for on-line composition analysis in distillation columns. Laboratory evaluation and instrument employs an air-cooled laser and a thermoelectrically cooled detector. The device is mounted on a three by foot cart for convenient location in control rooms. Current fiber optic extension cables allow for analysis in a cell thirty five meters from the ...

1992-01-01

130

Nuclear mass prediction as an image reconstruction problem: can observed pattern determine mass values?  

Energy Technology Data Exchange (ETDEWEB)

Theoretical prediction of nuclear masses is analyzed as a pattern recognition problem on the N-Z plane. A global pattern is observed by plotting the differences between measured masses and Liquid Drop Model (LDM) predictions. After unfolding the data by removing the smooth LDM mass contributions, the remaining microscopic effects have proved difficult to model, although they display a striking pattern. These deviations carry information related to shell closures, nuc]ear deformation and the residual nuclear interactions. In the present work the more than 2000 known nuclear masses are studied as an array in the N-Z plane viewed through a mask, behind which the approximately 7000 unknown unstable nuclei that can exist between the proton and neutron drip lines are hidden. We show here that employing a Fourier transform deconvolution method these by masses can be predicted with similar accuracy than standard methods. We believe that a more general ...

2006-07-01

131

Nuclear mass prediction as an image reconstruction problem: can observed pattern determine mass values?  

International Nuclear Information System (INIS)

Theoretical prediction of nuclear masses is analyzed as a pattern recognition problem on the N-Z plane. A global pattern is observed by plotting the differences between measured masses and Liquid Drop Model (LDM) predictions. After unfolding the data by removing the smooth LDM mass contributions, the remaining microscopic effects have proved difficult to model, although they display a striking pattern. These deviations carry information related to shell closures, nuc]ear deformation and the residual nuclear interactions. In the present work the more than 2000 known nuclear masses are studied as an array in the N-Z plane viewed through a mask, behind which the approximately 7000 unknown unstable nuclei that can exist between the proton and neutron drip lines are hidden. We show here that employing a Fourier transform deconvolution method these by masses can be predicted with similar accuracy than standard methods. We believe that a more general ...

132

Micropatterned polysaccharide surfaces via laser ablation for cell guidance  

Energy Technology Data Exchange (ETDEWEB)

Micropatterned materials were obtained by a controlled laser ablation of a photoimmobilised homogeneous layer of hyaluronic acid (Hyal) and its sulphated derivative (HyalS). The photoimmobilisation was performed by coating the polysaccharide, adequately functionalised with a photoreactive group, on aminosilanised glass substrate and immobilising it on the surface under UV light. Hyal or HyalS photoimmobilised samples were then subjected to laser ablation with wavelengths in the UV regions in order to drill the pattern. Four different patterns with stripes of 100, 50, 25 and 10 {mu}m were generated. A chemical characterisation by attenuated total reflection/Fourier transform infrared (ATR/FT-IR) and time of flight-secondary ions mass spectrometry (TOF-SIMS) confirmed the success of the laser ablation procedure and the presence of alternating stripes of polysaccharide and native glass. The exact dimensions of the stripes were determined by atomic ...

2003-03-03

133

Merging of airborne gravity and gravity derived from satellite altimetry: Test cases along the coast of greenland  

DEFF Research Database (Denmark)

The National Survey and Cadastre - Denmark (KMS) has for several years produced gravity anomaly maps over the oceans derived from satellite altimetry. During the last four years, KMS has also conducted airborne gravity surveys along the coast of Greenland dedicated to complement the existing onshore gravity coverage and fill in new data in the very-near coastal area, where altimetry data may contain gross errors. The airborne surveys extend from the coastline to approximately 100 km offshore, along 6000 km of coastline. An adequate merging of these different data sources is important for the use of gravity data especially, when computing geoid models in coastal regions. The presence of reliable marine gravity data for independent control offers an opportunity to study procedures for the merging of airborne and satellite data around Greenland. Two different merging techniques, both based on collocation, are investigated in this paper. Collocation offers a way of combining the individual ...

2002-01-01

134

Kinetic investigations of graft copolymerization of sodium styrene sulfonate onto electron beam irradiated poly(vinylidene fluoride) films  

Energy Technology Data Exchange (ETDEWEB)

Graft copolymerization of sodium styrene sulfonate (SSS) onto electron beam (EB) irradiated poly(vinylidene fluoride) (PVDF) films was investigated to find out a simple preparation process for sulfonic acid proton exchange membranes with respect to monomer concentration, absorbed dose, temperature, film thickness and storage time. The reaction order of the monomer concentration and absorbed dose of grafting was found to be 2.84 and 1.20, respectively. The overall activation energy for graft copolymerization reaction was calculated to be 11.36 kJ/mol. The initial rate of grafting was found to decrease with an increase in the film thickness. The trapped radicals in the irradiated PVDF films remained effective in initiating the reaction without considerable loss in grafting level up to 180 days, when stored under -60 {sup o}C. The presence and distribution of polystyrene sulfonate grafts in the obtained membranes were observed by Fourier transform ...

2011-01-15

135

Isolation and characterization of humic acids from peat soil  

International Nuclear Information System (INIS)

In this study, two different humic acids extracted from England and China peat soil, as well as three purified products extracted from commercially available humic acids [Fluka (Fluka, Neu-Ulm, Germany, Alfa (Alfa Aesar, Ward Hill, USA) and Aldrich (Aldrich-Chemical Co, Gillingham-Dorset)] were obtained respectively with the modified IHSS (International humic substances society) procedure. The chemical and structural information of these humic acids were characterized by some techniques, such as elemental analysis, ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR) and electropotential titration. UV-Vis spectra, infrared spectra, values for elemental composition and the contents of carboxyls, phenolic hydroxyls and total acidities of these humic acids were acquired. It is indicated that all these humic acids are different in the aspect of chemical structure, respectively, and these humic acids would be ...

2009-05-01

136

Interactions of metal cations with anionic groups on the cell Wall of the macroalga vaucheria sp.  

Energy Technology Data Exchange (ETDEWEB)

The aim of this article was to investigate the interactions of metal cations in aqueous solutions with the biomass of the freshwater macroalga Vaucheria sp. This problem is important when elaborating new applications of biosorption, e.g. the production of mineral feed additives for livestock from the biomass of algae enriched with microelement ions. Potentiometric titration was applied as a quick and cheap screening test to search for new efficient biosorbents. It revealed a variety of functional groups capable of cation exchange on the macroalgal surface, including carboxyl, phosphate, hydroxyl or amino groups. Fourier transform infrared spectroscopy on natural and chromium-loaded Vaucheria sp. confirmed that carboxyl groups played a dominant role in the biosorption. The study also showed that Ca(II), Na(I), K(I), and Mg(II) ions were released from the biomass after biosorption of Cu(II), Mn(II), Zn(II), and Co(II) ions, indicating that ion ...

2010-06-15

137

Interaction of bovine serum albumin with some novel PEG-containing diblock copolymers  

British Library Electronic Table of Contents (United Kingdom)

A comparative study on the interaction of different PEG-containing diblock copolymers including SA400, SA600, SA1500 and OA1500 (stearyl and oleyl esters of polyethylene glycol with 400, 600 and 1500 molecular weights, respectively) with bovine serum albumin (BSA) was carried out using isothermal titration calorimetry (ITC), attenuated total reflectance Fourier transform infrared (ATR-FTIR), circular dichroism (CD), and fluorescence spectroscopies. ITC data show that SA400, SA600, SA1500 and OA1500 bind to BSA, with association constants of (14.5, 3.16, 50.7 and 17.6)x103M-1, respectively. Results also show that the binding is enthalpically driven, disfavored by conformational entropy. Quantitative analysis of the FTIR absorbance spectra at amide Iprime (1600-1700cm-1) as well as far UV ci...

2008-01-01

138

Improvement of spatial resolution in the longitudinal direction for isotropic imaging in helical CT  

Energy Technology Data Exchange (ETDEWEB)

Experiments were conducted to confirm the isotropic spatial resolution of multislice CT with a 0.5 mm slice thickness. Isotropic spatial resolution means that the spatial resolution in the transaxial plane (X-Y plane) and that in the longitudinal direction (Z direction) are equivalent. To obtain point spread function (PSF) values in the X-Y-Z directions, three-dimensional voxel data were obtained by helical scanning of a bead phantom. The modulation transfer function (MTF) values were then obtained by three-dimensional Fourier transform of the PSF. Evaluation of the spatial resolution in the X-Y-Z directions by the MTF values showed that the spatial resolution in the Z direction does not depend on the reconstruction kernel used. It was also found that the spatial resolution in the Z direction, as compared with that in the X-Y plane, is superior with the standard kernel for the abdomen and is inferior with the high-definition kernel for the ...

2007-02-07

139

High resolution Fourier transform spectroscopy and crystal-field analysis in Tm,Ho:BaY{sub 2}F{sub 8}  

Energy Technology Data Exchange (ETDEWEB)

A Tm{sup 3+}- Ho{sup 3+} -codoped single crystal of monoclinic BaY{sub 2}F{sub 8} has been characterized by means of high resolution FTIR spectroscopy in the wave number range 2000-24000 cm{sup -1} and in the temperature range 9-300 K. The energy level schemes of the two lanthanide ions as determined by the optical absorption spectra is presented, analyzed, and fitted within a single ion Hamiltonian model. The very small energy separation (about 0.6-1.6 cm{sup -1}) measured between the first and second sublevels of the ground state manifolds for both the ions is in line with the theoretical predictions. The impurity-phonon coupling is put into evidence by the thermally induced line shift and broadening, and by the detection of vibronic replicas of a few lines. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

2005-01-01

140

High resolution Fourier transform spectroscopy and crystal-field analysis in Tm,Ho:BaY_2F_8  

International Nuclear Information System (INIS)

A Tm"3"+- Ho"3"+ -codoped single crystal of monoclinic BaY_2F_8 has been characterized by means of high resolution FTIR spectroscopy in the wave number range 2000-24000 cm"-"1 and in the temperature range 9-300 K. The energy level schemes of the two lanthanide ions as determined by the optical absorption spectra is presented, analyzed, and fitted within a single ion Hamiltonian model. The very small energy separation (about 0.6-1.6 cm"-"1) measured between the first and second sublevels of the ground state manifolds for both the ions is in line with the theoretical predictions. The impurity-phonon coupling is put into evidence by the thermally induced line shift and broadening, and by the detection of vibronic replicas of a few lines. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

2005-01-01

141

Functionalizing titania nanoparticle surfaces in a fluidized bed plasma reactor  

International Nuclear Information System (INIS)

Functionalizing nanoparticle surfaces is essential for achieving homogeneous dispersions of monodisperse particles in polymer nanocomposites for successful utilization in engineering applications. Functionalization reduces the surface energy of the nanoparticles, thereby limiting the tendency to agglomerate. Moreover, reactive groups on the surface can also participate in the polymerization, creating covalent bonds between the inorganic and organic phases. In this paper, a fluidized bed inductively coupled plasma (FB-ICP) reactor is used to break apart the agglomerates and functionalize commercial TiO2 nanoparticle powders in a batch of several grams. The fluidized bed could be implemented into a continuous flow reactor, potentially making this a viable method to treat larger quantities of commercial powders. The particles are treated with acrylic acid (AA) and tetraethylorthosilicate (TEOS) plasma and the functionalized particles were collected separately from bulk powder. High ...

2009-11-18

142

Evaluation of the potential of pentachlorophenol degradation in soil by pulsed corona discharge plasma from soil characteristics.  

Science.gov (United States)

Chlorinated organics are frequently found as harmful soil contaminants and persisted for extended periods of time. A novel approach, named pulsed corona discharge plasma (PCDP), was employed for the degradation of pentachlorophenol (PCP) in soil. Experimental results showed that 87% of PCP could be smoothly removed in 60 min. Increasing pulse voltage, enhancing soil pH, lowering humic acid (HA) in soil and reducing granular size of the soil were found to be favorable for PCP degradation efficiency. Oxidation and physical processes simultaneously contributed to PCP removal in soil and ozone was the main factor in PCDP treatment. C-Cl bonds in PCP were cleaved during PCDP treatment by Fourier transform infrared spectroscopy (FTIR) analysis. The mineralization of PCP was confirmed by total organic carbon (TOC) and dechlorination analyses. The main intermediate products such as tetrachlorocatechol, tetrachlorohydroquinone, acetic acid, formic acid, ...

2010-04-15

143

Electrochemical properties of Si/Ni alloy-graphite composite as an anode material for Li-ion batteries  

International Nuclear Information System (INIS)

Si/Ni alloy and graphite composites were synthesized using arc-melting followed by high energy mechanical milling (HEMM). Alloy particles comprising of NiSi2, NiSi and Si phases were distributed finely and uniformly on the surface of graphite in the composites obtained after Hem. The composite containing 60 wt.% of Si/Ni alloy exhibited a stable capacity of ?780 mAh/g. Fourier transform infrared spectroscopy (FTIR) analysis confirmed that some bonds were formed between alloy and graphite after HEMM, which appeared to retain the electrical connection between alloy and graphite during cycling. X-ray diffraction (XRD) analysis indicated that NiSi2 and NiSi phases, which acted as an inactive alloy matrix remained invariant during charge and discharge. In addition to NiSi2 and NiSi phases, disordered graphite layers also played the role of media for the accommodation of large volume change of Si during cycling. The large reversible capacity and good ...

2005-09-30

144

Effects of palladium particle size and palladium silicide formation on fourier transform infrared spectra of CO adsorbed on Pd/SiO sub 2 catalysts  

Energy Technology Data Exchange (ETDEWEB)

Two major modes of CO adsorption on SiO{sub 2}-supported Pd reflect different extents of back-donation, which is, at least in part, controlled by the local electron density at the adsorption site. The fraction of CO in the bridging mode (B) increases and that of the linear mode (L) decreases, with increasing size of the Pd particles, indicating high electron density at Pd atoms in terraces of close-packed crystal faces, in agreement with Smoluchowski's classical model. For samples reduced at 300{degree}C our data points and those of other authors are located on a common curve of B/L vs metal dispersion. Extensive reduction at 600{degree}C results in significantly lower B/L values, attributed to the incipient formation of a palladium silicide. Oxidation followed by reduction at 300{degree}C destroys the silicide, and the B/L value returns to the original curve.

1989-06-15

145

Effects of palladium particle size and palladium silicide formation on fourier transform infrared spectra of CO adsorbed on Pd/SiO sub 2 catalysts  

Science.gov (United States)

Two major modes of CO adsorption on SiO{sub 2}-supported Pd reflect different extents of back-donation, which is, at least in part, controlled by the local electron density at the adsorption site. The fraction of CO in the bridging mode (B) increases and that of the linear mode (L) decreases, with increasing size of the Pd particles, indicating high electron density at Pd atoms in terraces of close-packed crystal faces, in agreement with Smoluchowski's classical model. For samples reduced at 300{degree}C our data points and those of other authors are located on a common curve of B/L vs metal dispersion. Extensive reduction at 600{degree}C results in significantly lower B/L values, attributed to the incipient formation of a palladium silicide. Oxidation followed by reduction at 300{degree}C destroys the silicide, and the B/L value returns to the original curve.

1989-06-15

146

Effects of oxygenated blending compounds on emissions from a turbo-charged direct injection diesel engine  

Energy Technology Data Exchange (ETDEWEB)

An experimental investigation was conducted to evaluate the effect of three different oxygenated compounds, diglyme, diethyl maleate and dibutyl maleate, on emissions from a Volkswagen 1.9 litre, turbocharged, direct injection diesel engine. Sampling was performed using a mini-dilution tunnel technique to obtain particulate matter and a Fourier transform infrared (FTIR) spectrometer for gaseous emissions. The particulate samples were analysed using thermal analysis and Soxhlet extraction to determine the fraction of volatile and soluble organic material respectively. All three oxygenated compounds were found to be effective at reducing particulate emissions, with the maleate compounds being more effective overall than the diglyme. Analysis of the relative contributions of changes in the soot and soluble organic fraction (SOF) to the reduction of particulate matter indicated that, for diethyl maleate and diglyme, reductions in soot were the ...

2000-02-01

147

Detecting exposure to environmental organic toxins in individual cells: towards development of a micro-fabricated device  

Energy Technology Data Exchange (ETDEWEB)

A new method is being developed to quickly screen for the human exposure potential to polycyclic aromatic hydrocarbons (PAHs) and organochlorines (OCs). The development involves two key elements: identifying suitable signals that represent intracellular changes that are specific to PAH and OC exposure, and constructing a device to guide the biological cell growth so that signals from individual cells are consistent and reproducible. We are completing the identification of suitable signals by using synchrotron radiation-based (SR) Fourier-transform infrared (FTIR) spectromicroscopy in the mid-infrared region (4000-400 cm-1). Distinct changes have been observed in the IR spectra after treatment of human cells in culture medium with PAHs and OCs. The potential use of this method for detecting exposure to PAHs and OCs has been tested and compared to a reverse transcription polymerase chain reaction (RT-PCR) assay that quantifies increased expression of the CYP1A1 gene ...

1999-01-10

148

Deposition of plasma-polymerized hydroxyethyl methacrylate (HEMA) on silicon in presence of argon plasma  

International Nuclear Information System (INIS)

2-hydroxyethyl methacrylate (HEMA) has been deposited onto the surface of silicon substrate (thickness = 500 ?m) using plasma polymerization technique. Polymerization process was carried out in an in-house developed inductively coupled plasma polymerization setup. The depositions were carried out using RF power supply (13.56 MHz) at power of 75 W for 10 and 40 min. The RF supply was coupled to the inductance through a matching network. The effect of plasma polymerization (surface grafting) on the degree of surface modification has been investigated. The chemical changes on the polymer backbone are followed from the results of Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS), which show the peaks corresponding to the functional groups of the HEMA polymerized onto the silicon surface. The morphology of the modified surfaces has also been investigated using scanning electron microscopy (SEM) and atomic ...

2005-05-30

149

Cyclopropane isomerization over Eu[sup 3+]NaX zeolites  

Energy Technology Data Exchange (ETDEWEB)

Cyclopropane isomerization to propylene over various Eu[sup 3+] loadings in NaX zeolite have been studied by measurements of steady-state and transient kinetics and by Fourier transform infrared spectroscopy. As Eu[sup 3+] loading increases, the rate of deactivation increases, the conversion increases, apparent activation energies are lowered, and Bronsted acid site strength and amounts increase. Apparent activation energies of 13-15 kcal/mol for propylene formation have been observed for these systems, consistent with literature reports for other metal supported heterogeneous catalyst systems. Deactivation studies have shown that activity can be restored by heating in He at 380[degrees]C between various temperature runs, and that gases desorbed during regeneration are predominantly propylene. Poisoning studies of Bronsted sites with Na vapor lead to deactivation of these catalysts. A reaction mechanism scheme based on [pi] allyl intermediates ...

1992-11-01

150

Creating an EPICS Based Test Stand Development System for a BPM Digitizer of the Linac Coherent Light Source  

Energy Technology Data Exchange (ETDEWEB)

The Linac Coherent Light Source (LCLS) is required to deliver a high quality electron beam for producing coherent X-rays. As a result, high resolution beam position monitoring is required. The Beam Position Monitor (BPM) digitizer acquires analog signals from the beam line and digitizes them to obtain beam position data. Although Matlab is currently being used to test the BPM digitizer?s functions and capability, the Controls Department at SLAC prefers to use Experimental Physics and Industrial Control Systems (EPICS). This paper discusses the transition of providing similar as well as enhanced functionalities, than those offered by Matlab, to test the digitizer. Altogether, the improved test stand development system can perform mathematical and statistical calculations with the waveform signals acquired from the digitizer and compute the fast Fourier transform (FFT) of the signals. Finally, logging of meaningful data into files has been added.

2011-06-22

151

Controllable synthesis of graphene sheets with different numbers of layers and effect of the number of graphene layers on the specific capacity of anode material in lithium-ion batteries  

International Nuclear Information System (INIS)

High quality graphene sheets are synthesized through efficient oxidation process followed by rapid thermal expansion and reduction by H2. The number of graphene layers is controlled by tuning the oxidation degree of GOs. The higher the oxidation degree of GOs is getting, the fewer the numbers of graphene layers can be obtained. The material is characterized by elemental analysis, thermo-gravimetric analysis, scanning electron microscopy, atomic force microscopy, transmission electron microscopy and Fourier transform infrared spectroscopies. The obtained graphene sheets with single, triple and quintuplicate layers as anode materials exhibit a high reversible capacity of 1175, 1007, and 842 mA h g-1, respectively, which show that the graphene sheets with fewer layers have higher reversible capacity. -- Graphical abstract: The typical TEM images of the graphene sheets derived from GO3(a), GO2(b) and GO1(c). Display Omitted Highlights: ? With the ...

2011-05-01

152

Collection of VLE data for acid gas-alkanolamine systems using Fourier transform infrared spectroscopy. Technical report, October 1, 1994--July 31, 1995  

Energy Technology Data Exchange (ETDEWEB)

The industrial standard process for the purification of natural gas is to remove acid gases, mainly hydrogen sulfide and carbon dioxide, by the absorption and reaction of these gases with alkanolamines. The natural gas industry requires vapor-liquid equilibrium (VLE) data to develop more energy efficient amine mixtures. Some energy reductions have been realized in the past decade by applying such amine systems as hindered amines, methyldiethanolamine (MDEA), and MDEA based amine mixtures. However, the lack of reliable and accurate VLE data impedes the commercial application of these more efficient alkanolamine systems. The first objective of this project is to improve the accuracy of vapor-liquid equilibrium measurements at low hydrogen sulfide concentrations. The second objective is to make VLE measurements for amine mixtures. By improving the accuracy of the VLE data on MDEA and other amines, energy savings can be implemented in the many existing absorption units already in use. If ...

1995-08-01

153

Collection of VLE data for acid gas-alkanolamine systems using Fourier transform infrared spectroscopy. Phase 1, September 29, 1990--September 30, 1991  

Energy Technology Data Exchange (ETDEWEB)

The industrial standard process for the purification of natural gas is to remove acid gases, mainly hydrogen sulfide and carbon dioxide, by the absorption and reaction of these gases with alkanolamines. Inadequate data for vapor -- liquid equilibrium (VLE) hinder the industry from converting operations to more energy efficient amine mixtures and conserving energy. Some energy reductions have been realized in the past decade by applying such amine systems as ``hindered`` amines, methyldiethanolamine (MDEA), and MDEA based amine mixtures. However, the lack of reliable and accurate fundamental VLE data impedes the commercial application of these more efficient alkanolamine systems. The first project objective is to improve the accuracy of vapor -- liquid equilibrium measurements at low hydrogen sulfide concentrations. The second project objective is to measure the VLE for amine mixtures. By improving the accuracy of the VLE measurements on MDEA and mixtures with other amines, energy ...

1991-09-01

154

Collection of VLE data for acid gas-alkanolamine systems using Fourier transform infrared spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

The industrial standard process for the purification of natural gas is to remove acid gases, mainly hydrogen sulfide and carbon dioxide, by the absorption and reaction of these gases with alkanolamines. Inadequate data for vapor -- liquid equilibrium (VLE) hinder the industry from converting operations to more energy efficient amine mixtures and conserving energy. Some energy reductions have been realized in the past decade by applying such amine systems as hindered'' amines, methyldiethanolamine (MDEA), and MDEA based amine mixtures. However, the lack of reliable and accurate fundamental VLE data impedes the commercial application of these more efficient alkanolamine systems. The first project objective is to improve the accuracy of vapor -- liquid equilibrium measurements at low hydrogen sulfide concentrations. The second project objective is to measure the VLE for amine mixtures. By improving the accuracy of the VLE measurements on MDEA and mixtures with other ...

1991-09-01

155

Chemical imaging of wood-polypropylene composites.  

Science.gov (United States)

Recent investigations of wood plastic composites have revealed a detrimental effect of using lubricant systems in production. This includes nullifying part or all of the mechanical benefit of using a polar compatibilizer, maleic anhydride polypropylene (MAPP), in the composite formulation. This investigation utilizes lubricants labeled with deuterium in conjunction with Fourier transform infrared (FT-IR) spectroscopy to allow for the separation of individual lubricants from all other material constituents. All of the deuterium labeled lubricants, used without MAPP, revealed their expulsion from the wood interface during crystallization. MAPP coupling agent was found to exist near the wood, but it is unclear if any covalent bonding with the hydroxyl functionality on the wood surface occurred. The addition of zinc stearate lubricants appears to nullify the activity of the anhydride functionality near the wood surface as evidenced by a shift in ...

2006-08-01

156

Born-Oppenheimer breakdown effects and hyperfine structure in the rotational spectrum of strontium monosulfide, SrS  

Energy Technology Data Exchange (ETDEWEB)

A newly constructed Fourier transform microwave spectrometer has been used to record the pure rotational spectra of four isotopomers of SrS ({sup 88}Sr{sup 32}S, {sup 87}Sr{sup 32}S, {sup 86}Sr{sup 32}S, and {sup 88}Sr{sup 34}S) between 6 and 26 GHz. The molecules were produced by reacting laser ablated strontium with carbonyl sulfide (0.1% in argon). Pure rotational transitions in the ground, first and second vibrational states have been observed. The data set has enabled a multi-isotopomer fit. Born-Oppenheimer breakdown terms for both atoms have been determined. The {sup 87}Sr nuclear quadrupole coupling constant in {sup 87}Sr{sup 32}S has been determined for the first time.

2007-12-06

157

Analysis of complex systems using neural networks  

Energy Technology Data Exchange (ETDEWEB)

The application of neural networks, alone or in conjunction with other advanced technologies (expert systems, fuzzy logic, and/or genetic algorithms), to some of the problems of complex engineering systems has the potential to enhance the safety, reliability, and operability of these systems. Typically, the measured variables from the systems are analog variables that must be sampled and normalized to expected peak values before they are introduced into neural networks. Often data must be processed to put it into a form more acceptable to the neural network (e.g., a fast Fourier transformation of the time-series data to produce a spectral plot of the data). Specific applications described include: (1) Diagnostics: State of the Plant (2) Hybrid System for Transient Identification, (3) Sensor Validation, (4) Plant-Wide Monitoring, (5) Monitoring of Performance and Efficiency, and (6) Analysis of Vibrations. Although specific examples described ...

1992-01-01

158

Analysis of complex systems using neural networks  

Energy Technology Data Exchange (ETDEWEB)

The application of neural networks, alone or in conjunction with other advanced technologies (expert systems, fuzzy logic, and/or genetic algorithms), to some of the problems of complex engineering systems has the potential to enhance the safety, reliability, and operability of these systems. Typically, the measured variables from the systems are analog variables that must be sampled and normalized to expected peak values before they are introduced into neural networks. Often data must be processed to put it into a form more acceptable to the neural network (e.g., a fast Fourier transformation of the time-series data to produce a spectral plot of the data). Specific applications described include: (1) Diagnostics: State of the Plant (2) Hybrid System for Transient Identification, (3) Sensor Validation, (4) Plant-Wide Monitoring, (5) Monitoring of Performance and Efficiency, and (6) Analysis of Vibrations. Although specific examples described ...

1992-12-31

159

Advanced nanoscale separations and mass spectrometry for sensitive high-throughput proteomics  

Energy Technology Data Exchange (ETDEWEB)

We review recent development in separations and mass spectrometric instrumentation for sensitive and high-throughput proteomic analyses. These efforts have been primarily focused on the development of high-efficiency (separation peak capacity of ~103) nanoscale liquid chromatography (nanoLC; e.g., flow rates extending down to ~20 nL/min at optimal separation linear velocities through narrow packed capillaries) in combination with advanced mass spectrometry (MS), including high sensitivity and high resolution Fourier transform ion cyclotron resonance (FTICR) MS. This technology enables MS analysis of low nanogram-level proteomic samples (i.e., nanoscale proteomics) with individual protein identification sensitivity at the low zeptomole-level. The resultant protein measurement dynamic range can reach 106 for nanogram-sized proteomic samples, while more abundant proteins can be detected from complex sub-picogram size proteome samples. The average ...

2005-06-01

160

A study of the physical-chemical mechanisms and variables which affect the transport of inorganic and organic heterogeneous systems  

Science.gov (United States)

In order to model transport of dissolved ions in subsurface environments, one should understand how these ions interact with solid phase adsorbents. Our primary goal has been investigating the reaction mechanisms which affect microcontaminant partitioning between aqueous solutions and solid phase adsorbents, using goethite ({alpha}-FeOOH) as a model adsorbent. Cylindrical internal reflection -- Fourier transform infrared (CIR-FTIR) spectroscopy has been developed as the primary technique for this study. Wet chemical adsorption studies, acoustophoresis and electrophoretic mobility have been used to obtain supporting information as needed. Phenol and o-nitrophenol did not adsorb to goethite. Benzoate, phthalate and p-hydroxybenzoate all adsorbed via a bidentate mechanism to two adjacent iron atoms, while salicylate and 2,4-dihydroxybenzoate formed a chelate complex to single iron atoms. Phosphate adsorption was predominately bidentate.

1990-07-01

161

A comparative study of natural, formaldehyde-treated and copolymer-grafted orange peel for Pb(II) adsorption under batch and continuous mode  

Energy Technology Data Exchange (ETDEWEB)

Natural, formaldehyde-treated and copolymer-grafted orange peels were evaluated as adsorbents to remove lead ions from aqueous solutions. The optimum pH for lead adsorption was found to be pH 5. The adsorption process was fast, reaching 99% of sorbent capacity in 10 min for the natural and treated biomasses and 20 min for the grafted material. The treated biomass showed the highest sorption rate and capacity in the batch experiments, with the results fitting well to a pseudo-first order rate equation. In the continuous test with the treated biomass, the capacity at complete exhaustion was 46.61 mg g{sup -1} for an initial concentration of 150 mg L{sup -1}. Scanning electronic microscopy and energy dispersive X-ray spectroscopy indicated that the materials had a rough surface, and that the adsorption of the metal took place on the surface. Fourier transform infrared spectroscopy revealed that the functional groups responsible for metallic ...

2009-01-30

162

Design and operating experience of a 40 MW, highly-stabilized power supply  

Energy Technology Data Exchange (ETDEWEB)

Four 10 MW, highly-stabilized power supply modules have been installed at the National High Magnetic Field Laboratory in Tallahassee, FL, to energize water-cooled, resistive, high-field research magnets. The power supply modules achieve a long term current stability if 10 ppM over a 12 h period with a short term ripple and noise variation of <10 ppM over a time period of one cycle. The power supply modules can operate independently, feeding four separate magnets, or two, three or four modules can operate in parallel. Each power supply module consists of a 12.5 kV vacuum circuit breaker, two three-winding, step-down transformers, a 24-pulse rectifier with interphase reactors, and a passive and an active filter. Two different transformer tap settings allow rated dc supply output voltages of 400 and 500 V. The rated current of a supply module is 17 kA and each supply module has a ...

1995-07-01

163

Development of a computerized portal verification scheme for pelvic treatment fields  

International Nuclear Information System (INIS)

Purpose/Objective: At present, treatment verification between portal and reference images is performed based on manually-identified features by radiation oncologist, which is both time-consuming and potentially error-prone. There is a demand for the computerized verification procedure in clinical application. The purpose of this study is to develop a computerized portal verification scheme for pelvic treatment fields. Materials/Methods: The automated verification system involves image acquisition, image feature extraction, feature matching between reference and portal images and quantitative evaluation of patient setup. Electronic portal images with a matrix size of 256 x 256 and 12 bit gray levels were acquired using a liquid matrix electronic portal imaging device. Simulation images were acquired by digitizing simulation films using a TV camera into images with 256 x 256 matrix and 8 bit gray levels. Initially a Canny edge detector is applied to identify the field edges and an ...

1996-09-01

164

Density of states model for the lattice transformation in A-15 compounds  

International Nuclear Information System (INIS)

The cubic-tetragonal lattice transformation in A-15 compounds is described by an empirical model in which the density of states function near the Fermi energy is characterized by a two-parametric peak in addition to the constant part. Two types of peak splitting under tetragonal deformation are considered, leading to qualitatively different results about the phase transition. Results are given for the order parameter, the phase stability, the soft elastic modulus, and the paramagnetic spin susceptibility. Comparing with measurements of the magnetic susceptibility of V_3Si single crystals near the phase transition a better agreement is obtained for a twofold degenerate density of states peak than for a threefold degenerate one. (author).

165

Direct observation of ordered orbital of YTiO{sub 3} by the X-ray magnetic diffraction technique  

Energy Technology Data Exchange (ETDEWEB)

X-ray magnetic diffraction (XMD) technique was applied to an orbital ordering compound of ferromagnetic YTiO{sub 3} for the first time. The orbital-magnetic form factor {mu} {sub L}(k) and the spin-magnetic form factor {mu} {sub S}(k) were independently measured by utilizing the LS separation ability of the XMD. The {mu} {sub L}(k) was measured for ten reciprocal-lattice points. No significant values of the {mu} {sub L}(k) were observed for most of the reciprocal-lattice points within the estimated statistical errors, which suggested quenching of the orbital moment. The {mu} {sub S}(k) was measured for 22 reciprocal-lattice points. Fourier synthesis of the {mu} {sub S}(k) gave the spin density distribution m {sub S}(r) in the real space. The obtained m {sub S}(r) map shows the characteristic feature of the electron distribution of 3d electron in the t{sub 2g} state of a Ti atom coordinated by O{sup 2-} ...

2005-08-15

166

Twinning mechanism in PrCo_2C_x magnetic phase  

International Nuclear Information System (INIS)

A magnetic rhombohedral PrCo_2C_x (x = 0.05 #approx#0.25) phase (space group Rbar 3m), which is heavily twinned along the #left brace#110#right brace# and #left brace#211#right brace# planes, was identified. The twinning mechanism was explored by analyzing the reduction of crystal symmetry due to the cubic-rhombohedral phase transformation. The origin of the twinning and the formation of four twin variants were attributed to the insertion of carbon interstitials into Co_4 tetrahedrons along the bar 3 axis in the rhombohedral lattice, which corresponds to one of the four equivalent axes of its parent PrCo_2 cubic-lattice.

1997-04-04

167

The effects of radiation on unsteady mhd convective heat transfer past a semi-infinite vertical porous moving surface with variable suction  

Scientific Electronic Library Online (English)

Abstract in english Numerical solutions for the effects of radiation on a MHD convective heat transfer past a semi-infinite porous plate with a magnetic field are obtained. It is assumed that the porous plate moves with a constant velocity in the direction of fluid flow, and the free stream velocity follows the exponentially increasing small perturbation law. The magnetic field acts perpendicular to the porous surface which absorbs the fluid with a suction velocity varying with time. The gov (more) erning equations for the flow are transformed into a system of nonlinear ordinary differential equations by perturbation technique and then are solved numerically by using the shooting method. The effects of the various parameters on the velocity, temperature profiles as well as the surface skin-friction and surface heat transfer are illustrated graphically.

2008-12-01

168

Supersaturation of antiferromagnetically coupled multilayers: A comparative polarised neutron reflectometry study  

Energy Technology Data Exchange (ETDEWEB)

Reflectometric methods like polarised neutron reflectometry (PNR) and synchrotron Moessbauer reflectometry (SMR) are capable of investigating the plane-perpendicular and lateral magnetic structure of multilayers (MLs). Previously, a variety of domain formation and transformation phenomena was found and systematically studied in a Fe/Cr ML of strong antiferromagnetic coupling by PNR and SMR. Growth of the primary domains on passing the bulk-spin-flop transition was established. The domains were found to revert to their native state only in a field considerably higher than the apparent saturation field, a phenomenon referred to as the supersaturation domain memory effect (SDME). We present a comparative PNR study of two antiferromagnetically coupled Fe/Cr MLs with different magnetisation curves. We show that the distribution of the layer-layer coupling rather than the magnetic structure of the Cr spacer layer is responsible ...

2007-07-15

169

BOUNDARY LAYER FLOW AND DOUBLE DIFFUSION OVER AN UNSTEADY STRETCHING SURFACE WITH HALL EFFECT  

British Library Electronic Table of Contents (United Kingdom)

The present investigation is concerned with the effect of Hall currents on boundary layer flow, and heat and mass transfer of an electrically conducting fluid over an unsteady stretching sheet in the presence of a strong magnetic field. The electron-atom collision frequency is assumed to be relatively high, so that the Hall effect is assumed to exist, while the induced magnetic field is neglected. The governing time-dependent boundary layer equations for momentum, thermal energy, and concentration are reduced using a similarity transformation to a set of coupled ordinary differential equations. The similarity ordinary differential equations are then solved numerically by the successive linearization method together with the Chebyshev pseudo-spectral collocation method. Effects of the Prand...

2011-01-01

170

Experimental Electron Heat Diffusion in TJ-II ECRH Plasmas  

Energy Technology Data Exchange (ETDEWEB)

Interpretative transport has been used to revisit the global scalings of TJ-II ECRH plasmas from a local perspective. Density, rotational transform and ERCH power scans were analysed based upon Thomson Scattering data (electron density and temperature) in steady state discharges. A simple formula to obtain the thermal conductivity, assuming pure diffusion and negligible convective heat fluxes was used in a set of 161 discharges. All the analysis was performed with the ASTRA transport shell. The density scan indicates that inside n=0,4 there is no significant change of e with density in the range studied (0.4 <ne>(1019m-3) 1.0), while in 0,5 <0,8 approximately, e decreases with density. In the rotational transform scan it is found that the values of e when a low order rational of the rotational transform is present locally seem to be smaller for the corresponding range, although it is apparent a general ...

2006-07-01

171

Separation of variables for the quantum SL(2,R) spin chain  

CERN Document Server

We construct representation of the Separated Variables (SoV) for the quantum SL(2,R) Heisenberg closed spin chain and obtain the integral representation for the eigenfunctions of the model. We calculate explicitly the Sklyanin measure defining the scalar product in the SoV representation and demonstrate that the language of Feynman diagrams is extremely useful in establishing various properties of the model. The kernel of the unitary transformation to the SoV representation is described by the same "pyramid diagram" as appeared before in the SoV representation for the SL(2,C) spin magnet. We argue that this kernel is given by the product of the Baxter Q-operators projected onto a special reference state.

2003-01-01

172

Quantum Computing with an Electron Spin Ensemble  

DEFF Research Database (Denmark)

We propose to encode a register of quantum bits in different collective electron spin wave excitations in a solid medium. Coupling to spins is enabled by locating them in the vicinity of a superconducting transmission line cavity, and making use of their strong collective coupling to the quantized radiation field. The transformation between different spin waves is achieved by applying gradient magnetic fields across the sample, while a Cooper pair box, resonant with the cavity field, may be used to carry out one- and two-qubit gate operations.

2009-01-01

173

Properties of A-15 superconductors with defects  

International Nuclear Information System (INIS)

It is suggested that the large reduction of the superconducting transition temperature T sub(c) due to defects observed experimentally in some A-15 compounds is caused by smearing of a high peak in the density of states at the Fermi level. The influence of defects on other physical properties (the magnetic susceptibility chi, the elastic modulus C sub(s), the structural transformation temperature T sub(m) and the electrical resistivity rho) is also discussed from the same point of view. We expect the anomalous temperature dependence of chi C sub(s) and rho will be suppressed by defects. (auth.).

174

Magnetic braking in differentially rotating, relativistic stars  

International Nuclear Information System (INIS)

We study the magnetic braking and viscous damping of differential rotation in incompressible, uniform density stars in general relativity. Differentially rotating stars can support significantly more mass in equilibrium than nonrotating or uniformly rotating stars, according to general relativity. The remnant of a binary neutron star merger or supernova core collapse may produce such a 'hypermassive' neutron star. Although a hypermassive neutron star may be stable on a dynamical time scale, magnetic braking and viscous damping of differential rotation will ultimately alter the equilibrium structure, possibly leading to delayed catastrophic collapse. Here we treat the slow-rotation, weak-magnetic field limit in which E_r_o_t<magnetic energy, and W is the gravitational binding energy of the star. We assume the system ...

2004-02-15

175

Transformation and Transition: DARPA's Role in Fostering an ...  

Science.gov (United States)

Transformation and Transition: DARPA's Role in Fostering an Emerging Revolution ... IDA Paper P-3698 Transformation and Transition: DARPA's ...

2003-11-01

176

Transformation of the ATOMKI-ECRIS into a Plasma Device  

International Nuclear Information System (INIS)

Complete text of publication follows. In order to extend the capabilities of the electron cyclotron resonance (ECR) ion source (ECRIS) of ATOMKI it has been transformed into a special plasma facility [1,2]. The transformation is reversible and was simply done by changing several main components of the ion source by new ones, namely: the hexapole magnet, the plasma chamber and the microwave source. The basic requirements of the transformation were: (1) most parts of the present ECRIS should be used in the new assembly in the same way and (2) the transformation time between the two operation modes should not be more than 2-3 days (in both directions). The following sub-systems are used identically in both configurations: solenoid coils, vacuum system, gas dosing system, ovens, probes. The extraction optics and beam transport system can also be used in the new configuration to check ...

2006-01-01

177

Complete suppression of Pfirsch-Schlueter current in a toroidal l=3 stellarator  

Energy Technology Data Exchange (ETDEWEB)

Pfirsch-Schlueter (P-S) current is an inherent property of a finite pressure toroidal equilibrium of tokamak and stellarator. However, it was pointed out recently (V.D. Pustovitov, Nuclear Fusion 36 (1996) 583) that the P-S current would be suppressed completely if the external vertical field could be adjusted to satisfy the condition {omega}=<{omega}> in an l=3 stellarator. Here {omega}=<B tilde{sup 2}>/B{sub 0}{sup 2}-2{epsilon} cos{theta}, l is a pole number, |B tilde| the vacuum helical magnetic field, B{sub 0} the toroidal field, {epsilon} the inverse aspect ratio, {theta} the poloidal angle and <...> denotes the average over the toroidal angle. An example of such a stellarator equilibrium is presented in this paper. For this stellarator equilibrium, behavior of rotational transform and Boozer magnetic spectrum is clarified when the pressure is increased. Both formation of ...

1999-10-01

178

Structure and magnetic properties of nanostructural strontium ferrite prepared by mechanochemical treatment  

International Nuclear Information System (INIS)

Full text: It was recently-established for hexagonal barium ferrite-industrially important magnetically hard material that refinement of the crystallite dimensions into the nanoscale regime, typically #<=# 10 nm, leads after heat treatment at temperatures 800-1000 deg C to significant coercivity increase of up to 6.5 kOe (#approx#3-4 times) with saturation magnetisation values of 50-55 emu/g (#approx#95% of bulk at room temperature). High-energy mechanochemical processing has been applied to prepare nanostructural (nanocrystalline-amorphous) composites. High resolution electron microscopy studies reveal that the enhancement of the final magnetic properties was due to formation of magnetically noninteracting #approx#l,#mu#m Ba-ferrite particles with 5-10 nm amorphous surface layer - depending on annealing parameters. Similar situation was established also for ball milled strontium ferrite (SrFe_1_2O_1_9) powders where ...

180

Water structure as a function of temperature from X-ray scatteringexperiments and ab initio molecular dynamics  

Energy Technology Data Exchange (ETDEWEB)

We present high-quality X-ray scattering experiments on pure water taken over a temperature range of 2 to 77 C using a synchrotron beam line at the advanced light source (ALS) at Lawrence Berkeley National Laboratory. The ALS X-ray scattering intensities are qualitatively different in trend of maximum intensity over this temperature range compared to older X-ray experiments. While the common procedure is to report both the intensity curve and radial distribution function(s), the proper extraction of the real-space pair correlation functions from the experimental scattering is very difficult due to uncertainty introduced in the experimental corrections, the proper weighting of OO, OH, and HH contributions, and numerical problems of Fourier transforming truncated data in Q-space. Instead, we consider the direct calculation of X-ray scattering spectra using electron densities derived from density functional theory based on real-space ...

2003-03-01

181

Study of the electron beam irradiation effect on some properties of aromatic aliphatic copolyester films; Estudo do efeito da radiacao por feixe de eletrons nas propriedades de filmes de copoliester alifatico aromatico  

Energy Technology Data Exchange (ETDEWEB)

Biodegradable and green plastics are the new tendency in the world. The effect of the electron beam irradiation in aromatic aliphatic copolyester and the blend with corn starch films (Ecoflex{sup R} and Ecobras{sup R}) were studied by tensile strength at break, elongation at break, Scanning Electronic Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC), crosslinking degree and biodegradability. The measurements in both, the machine direction and the transverse direction were made for mechanical tests. It was found that, the electron irradiation caused an increase in the strength at break of the blend with corn starch film, when doses of up to 10 kGy were applied. A significant decrease of the elongation at break of the blend with corn starch was observed at doses of 10 kGy and 40 kGy. It was not found important change in tensile properties for aromatic aliphatic copolyester. Structural ...

2008-07-01

182

Study of the electron beam irradiation effect on some properties of aromatic aliphatic copolyester films  

International Nuclear Information System (INIS)

Biodegradable and green plastics are the new tendency in the world. The effect of the electron beam irradiation in aromatic aliphatic copolyester and the blend with corn starch films (Ecoflex"R and Ecobras"R) were studied by tensile strength at break, elongation at break, Scanning Electronic Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC), crosslinking degree and biodegradability. The measurements in both, the machine direction and the transverse direction were made for mechanical tests. It was found that, the electron irradiation caused an increase in the strength at break of the blend with corn starch film, when doses of up to 10 kGy were applied. A significant decrease of the elongation at break of the blend with corn starch was observed at doses of 10 kGy and 40 kGy. It was not found important change in tensile properties for aromatic aliphatic copolyester. Structural changes of the ...

183

Study of the Effects of Ambient Conditions Upon the Performance of Fan Powered, Infrared, Natural Gas Burners  

Energy Technology Data Exchange (ETDEWEB)

Fourier transform infrared spectroscopy is a simple, fast, reliable and nondestructive analytical method. By using the method developed in Clark Atlanta University, consistent and reliable infrared spectral results can be obtained. An accurate radiant energy can be calculated from these infrared spectra by using a blackbody as the calibration standards. By means of the specially-designed-and-lab-made sampling inlet and the Horiba gas analyzers, the compositions of CO{sub 2}, CO, UCH, NOx and O{sub 2} etc. from the combustion exhaust gases have been on-line accurately analyzed. The commercial natural gas IR burner performed differently in the different conditions. For the methane-air combustion, at the equivalence ratio {Phi} = 1, the IR burner produced its maximum radiation efficiency, {approximately}31.4%, and the concentration of CO{sub 2} reached its maximum value, {approximately}10.7%. In the fuel-lean region, the O{sub 2} concentration in ...

1997-03-31

184

Structures and properties of fluorinated amorphous carbon films  

International Nuclear Information System (INIS)

Fluorinated amorphous carbon (a-C:F) films were deposited by radio frequency bias assisted microwave plasma electron cyclotron resonance chemical vapor deposition with tetrafluoromethane (CF_4) and acetylene (C_2H_2) as precursors. The deposition process was performed at two flow ratios R=0.90 and R=0.97, where R=CF_4/(CF_4+C_2H_2). The samples were annealed at 300 deg. C for 30 min. in a N_2 atmosphere. Both Fourier transform infrared and electron spectroscopy for chemical analyzer were used to characterize the a-C:F film chemical bond and fluorine concentration, respectively. A high resolution electron energy loss spectrometer was applied to detect the electronic structure. The higher CF_4 flow ratio (R=0.97) produced more sp"3 linear structure, and it made the a-C:F film smoother and softer. A lifetime of around 0.34 #mu#s and an energy gap of #approx#2.75 eV were observed in both the as-deposited and after annealing conditions. The short ...

2004-07-01

185

Rheological phase synthesis and characterization of LiNiVO{sub 4} as a high voltage cathode material for lithium ion batteries  

Energy Technology Data Exchange (ETDEWEB)

A number of high voltage cathode materials are now being considered for their ability to increase the energy density of lithium-ion batteries. In this study, a lithium-nickel composite alloy (LiNiVO{sub 4}) was synthesized using a rheological phase reduction method that incorporated mixtures of LiOH-H{sub 2}O, Ni(CH{sub 3}COO){sub 2}, 4H{sub 2}O, NH{sub 4}VO{sub 3} and C{sub 2}H{sub 2}O{sub 4}-2H{sub 2}O. The rheological phase method was used to prepare the compounds from a solid-liquid rheological mixture. Solid reactants were first mixed in a proper molar ratio, and water or solvents were added to the solid-liquid rheological body. X-ray powder diffraction (XRD) and Fourier Transform (FT) analyses were conducted to characterize the powders. Scanning electron microscopy (SEM) was used to characterize the morphological features and particle sizes of the powders. Results of the analyses indicated that the single-phase LiNiVO{sub 4} composite is ...

2008-08-15

186

Raman spectroscopic studies of liquid phase ordering and dynamics for solutions of ME6N liquid crystal: the approach to simple molecule behavior at high dilutions.  

Science.gov (United States)

We have measured the Raman isotropic profiles of the ?(C?N) band at 2235 cm(-1) for five solutions of ME6N (4-cyanophenyl-4'-hexylbenzoate) liquid crystal dissolved in CCl(4) in the range from x = 0.12 to 0.007 (x, mole fraction of ME6N) and then obtained the corresponding vibrational correlation functions, C(v)(t), by time Fourier transformation. The increase with dilution of the dephasing times ?(v) complies with the behavior of the nonmonotonic concentration dependence predicted by the fluctuation concentration model for this concentration range (x Rothschild, which, being based on the assumption that the environmental modulation is described by a stretched exponential decay e(-(t/?(0))(?)), is more appropriate for the interpretation of the vibrational correlation function arising from a distribution of relaxation processes caused, as in the present case, by the persistence of pseudonematic domains. With dilution the dispersion parameter ? ...

2010-11-11

187

Properties of cubic boron nitride films with buffer layer control for stress relaxation using ion-beam-assisted deposition  

Energy Technology Data Exchange (ETDEWEB)

Significant ion irradiation during film growth is required for the formation of cubic boron nitride (cBN) films. Meanwhile, a huge level of intrinsic stress possibly induced by the ion bombardment has been frequently reported to result in cracking and/or lack of adhesion of deposited cBN films. The present work has been performed to investigate the interfacial and/or the buffer layer structures with better matching to the cBN film by relaxation of the film stress using ion-beam-assisted deposition (IBAD). Boron nitride films have been synthesized on Si(100) wafer and tungsten carbide (WC) substrates by depositing boron vapor under simultaneous bombardment with nitrogen ions and nitrogen-argon mixture ions in the energy range of 0.5-10 keV. Cubic BN films with enhanced tribological properties have been explored by inserting a BN layer with various B/N compositions as a controlled buffer at the interface. Significant relaxation of the film stress has been observed for the buffer layer ...

1999-09-01

188

Photodegradation and photostabilization of weathered wood flour filled polyethylene composites  

Science.gov (United States)

Wood plastic composites (WPCs) have gained popularity as building materials because of their usefulness in replacing solid wood in a variety of applications. These composites are promoted as being low-maintenance, high-durability products. However, it has been shown that WPCs exposed to weathering may experience a color change and/or loss in mechanical properties. An important requirement for building materials used in outdoor applications is the retention of their aesthetic qualities and mechanical properties during service life. Therefore, it is critical to understand the photodegradation mechanisms of WPCs exposed to UV radiation and to develop approaches to stabilize these composites against ultraviolet light. In this dissertation, the surface chemistries of weathered composites (both unstabilized and stabilized) as well as the effect of weathering on the color fade and the retention of mechanical properties were characterized. Since different methods of manufacturing WPCs lead to ...

2003-01-01

189

Neutron-computer tomography using real-time neutron radiography  

Energy Technology Data Exchange (ETDEWEB)

A real-time neutron radiography facility was constructed including the capability of neutron tomography. The neutron beam was measured for total neutron flux ((1.0 +/- 0.2) x 10/sup 11/ m/(m/sup 2/-sec)), gold cadmium ratio (52 +/- 3) and effective neutron temperature (83/sup 0/C +/- 8/sup 0/C). The angular divergence or nonparallelism of the neutron beam was measured to be 2.3/sup 0/ +/- 0.1/sup 0/ thereby providing a means of quantifying the collimator effectiveness. The resolution capabilities of both static film and real-time neutron radiographs were quantified using a Fourier transform algorithm to calculate the modulation transfer function of both types of radiographs. The contrast sensitivity of both types of radiographs. The contrast sensitivity of both types of radiographs was measured as 3.1% for film and 4.0% for real-time radiographs. Two tomography algorithms, the simultaneous iterative reconstruction technique (SIRT) and the ...

1986-01-01

190

Neutron-computer tomography using real-time neutron radiography  

International Nuclear Information System (INIS)

A real-time neutron radiography facility was constructed including the capability of neutron tomography. The neutron beam was measured for total neutron flux ((1.0 +/- 0.2) x 10"1"1 m/(m"2-sec)), gold cadmium ratio (52 +/- 3) and effective neutron temperature (83"0C +/- 8"0C). The angular divergence or nonparallelism of the neutron beam was measured to be 2.3"0 +/- 0.1"0 thereby providing a means of quantifying the collimator effectiveness. The resolution capabilities of both static film and real-time neutron radiographs were quantified using a Fourier transform algorithm to calculate the modulation transfer function of both types of radiographs. The contrast sensitivity of both types of radiographs. The contrast sensitivity of both types of radiographs was measured as 3.1% for film and 4.0% for real-time radiographs. Two tomography algorithms, the simultaneous iterative reconstruction technique (SIRT) and the convolution method, were ...

1986-01-01

191

Investigating the formation mechanism of soot-like materials present in blast furnace coke samples  

Science.gov (United States)

An attempt to gain an understanding of the formation mechanism of these 'soot-like' materials has been made by means of tracing the changes in the molecular-mass distribution and molecular structure of the NMP-extractable materials from an injectant coal as well as its partially gasified chars and its pyrolytic tars. Variations in the SEC chromatograms provide clues about changes in the apparent molecular-mass distributions of these NMP extracts. Results suggest that the build-up of 'soot-like' materials follows from the secondary reactions of tars evolved from the injectant coal. The likely secondary-reaction pathways have been probed by collating structural information on these NMP extracts. The time-resolved 13-16 and 22-25 min elution fractions from the SEC column have been characterized using UV fluorescence (UV F) spectroscopy. Greater concentrations of larger aromatic ring systems are found present in samples formed under conditions appearing ...

2008-09-15

192

In-situ FT-IR spectroscopic studies of coal drying. In-situ FT-IR ho wo mochiita sekitan no kanso ni kansuru kenkyu  

Energy Technology Data Exchange (ETDEWEB)

This paper discusses spectral change in brown coal and bituminous coal as a result of low-temperature drying. The experiment used a Fourier transform infrared (FT-IR) spectroscopy disposed with an in-situ diffuse reflector as a water content measuring method. The FT-IR spectra of coal showed the existence of two types of adsorbed water. One of the two spectral peaks was thought to have been caused by isolated water molecules which may have been hydrogen bonded to hydrocarbon in the coal molecules and weakly bound. The other peak was thought to have been caused by water which may have been hydrogen bonded to functional groups such as hydroxyl groups in the coal molecules and strongly bound. Drying behavior in brown coal and bituminous coal showed the absorption peak at 3640 cm[sup -1] reducing faster than the absorption peak at 3360cm[sup -1]. Depressurized drying was found to be more effective than flowing nitrogen gas. The extent of absorption ...

1993-01-29

193

Identification of hydrotreatment-resistant heteroatomic species in a crude oil distillation cut by electrospray ionization FT-ICR mass spectrometry  

Energy Technology Data Exchange (ETDEWEB)

The diminishing clean oil reserve is driving the search for new or improved ways to reduce the level of NSO-containing species found in high abundance in heavy crude oils. Hydrotreatment is the currently preferred technique to remove those polar species. Unfortunately, nitrogen-containing compounds cause coke formation on the surface of the hydrotreatment catalyst, leading to partial or complete deactivation. Here, positive- and negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) identify those nitrogen compounds that resist hydrotreatment. ESI preferentially ionizes polar (e.g., heteroatom-containing) species: basic molecules are detected as positive ions and acidic/neutral molecules as negative ions. FT-ICR MS resolves thousands of species in a single mass spectrum, allowing for unambiguous determination of elemental composition, C{sub c}H{sub h}N{sub n}O{sub o}S{sub s}, for ...

2006-10-15

194

Growth and characterization of new semi-organic L-proline strontium chloride monohydrate single crystals  

International Nuclear Information System (INIS)

The present communication deals with the synthesis, single crystal growth and characterization of a new nonlinear optical material L-proline strontium chloride monohydrate (L-PSCM). Single crystals have been grown using the slow solvent evaporation technique. Single crystal XRD analysis confirmed that the crystal belongs to the orthorhombic structure with lattice parameter a=6.6966(3) A, b=12.4530(5) A, c=15.2432(5) A and space group P2_12_12_1. Presence of various functional groups in L-PSCM and protonation of the ions were confirmed by Fourier transform infrared spectroscopy (FT-IR) analysis. The melting point of the single crystal was found to be 126 "oC using DSC. Ultraviolet-visible spectral analyses showed that the crystal has low UV cut-off at 226 nm combined with very good transparency of 90% in a wide range. The optical band gap was estimated to be 5.82 eV. Capacitance and dielectric-loss measurements were carried out at different ...

2011-01-01

195

General formulation of neutron noise for fast reactor systems  

Energy Technology Data Exchange (ETDEWEB)

A general space- and energy-dependent formalism is developed in order to analyze zero-power neutron noise experiments in fast reactor systems. A generalized dispersion equation is combined with theoretical expressions for the experimentally measured power spectral density and variance-to-mean ratio which makes it possible to express these quantities in terms of a double moment of the Laplace and Fourier transformed Green's function of a slowing-down operator rather than those of the full Boltzmann operator. Several spatial approximations are analyzed in the context of the general formalism. In each case, the power spectral density and variance-to-mean ratio are written in terms of an appropriate fast reactor dispersion law for the medium which can be calculated from the solution to a simple slowing-down equation. The resultant expression for the power spectral density are analyzed for various combinations of neutron migration ...

1982-01-01

196

Estimation of hydrogen bondings in coal utilizing FTir and differential scanning calorimetry (DSC); FTir to DSC wo mochiita sekitannai suiso ketsugo no teiryoteki hyoka no kokoromi  

Energy Technology Data Exchange (ETDEWEB)

With an objective to know coal condensation structure which has influence on coal conversion reaction, an attempt was made on quantitative evaluation of hydrogen bonding in coal. Using as test samples the VDC made from Taiheiyo coal swollen by tetralin and vacuum-dried, and its pyrolyzed char, DSC measurement and Fourier transform infrared spectroscopy (FT) were performed. An FT spectrum comparison revealed that the VDC swollen at 220{degree}C has the hydrogen bonding relaxed partly from the original coal. However, since the change is in a huge coal molecular structure restraining space, it has stopped at relaxation of the bonding energy without causing separation as far as free radicals. On the other hand, the DSC curve shows that the VDC has slower endothermic velocity than the original coal. In other words, the difference in heat absorption amounts in both materials is equivalent to the difference of enthalpy ({Delta} H) of both materials, ...

1996-10-28

197

Enhanced biosorption of nickel(II) ions by silica-gel-immobilized waste biomass: Biosorption characteristics in batch and dynamic flow mode  

Energy Technology Data Exchange (ETDEWEB)

Batch and dynamic flow biosorption studies were carried out using the waste biomass entrapped in silica-gel matrix for the removal of nickel(II) ions from synthetic solutions and real wastewater. Batch biosorption conditions were examined with respect to initial pH, S/L ratio, contact time, and initial nickel ion concentration. Zeta potential measurements showed that immobilized biosorbent was negatively charged in the pH range of 3.0-8.0. The immobilized biomass was found to possess relatively high biosorption capacity (98.01 mg g{sup -1}), and biosorption equilibrium was established in a short time of operation (5 min). The equilibrium data were followed by Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models. Scanning electron microscope analysis was used to screen the changes on the surface structure of the waste biomass after immobilization and nickel(II) biosorption. Sorbent-sorbate interactions were confirmed by Fourier ...

2009-04-30

198

Enhanced Activity of Nanocrystalline Zeolites for Selective Catalytic Reduction of NOx  

Energy Technology Data Exchange (ETDEWEB)

Nanocrystalline zeolites with discrete crystal sizes of less than 100 nm have different properties relative to zeolites with larger crystal sizes. Nanocrystalline zeolites have improved mass transfer properties and very large internal and external surface areas that can be exploited for many different applications. The additional external surface active sites and the improved mass transfer properties of nanocrystalline zeolites offer significant advantages for selective catalytic reduction (SCR) catalysis with ammonia as a reductant in coal-fired power plants relative to current zeolite based SCR catalysts. Nanocrystalline NaY was synthesized with a crystal size of 15-20 nm and was thoroughly characterized using x-ray diffraction, electron paramagnetic resonance spectroscopy, nitrogen adsorption isotherms and Fourier Transform Infrared (FT-IR) spectroscopy. Copper ions were exchanged into nanocrystalline NaY to increase the catalytic activity. ...

2006-12-31

199

Effects of inorganic cation templates on octahedral molecular sieves of manganese oxide  

Science.gov (United States)

Five hydrated inorganic divalent cations, Mg[sup 2+], Co[sup 2+], Ni[sup 2+], Cu[sup 2+], and Zn[sup 2+], have successfully been used as templates for the synthesis of manganese oxide octahedral molecular sieves (OMS-1) having the todorokite structure. The OMS-1 samples have been well characterized by X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy/energy dispersive X-ray studies, inductively coupled plasma analysis, electron paramagnetic resonance, Fourier transform infrared spectroscopy, thiosulfate titration, and cyclohexane sorption. Catalytic CO oxidation and 2-propanol decomposition were carried out. Results show that these OMS-1 samples with a tunnel size of about 6.9 angstroms are crystalline and chemically pure. They have the following formulas: Mg[sub 3.17]Mn[sub 5.05]O[sub 12] [center dot] 4.52H[sub 2]O, Co[sub 1.84]Mn[sub 5.59]O[sub 12] [center dot] 3.45H[sub 2]O, Ni[sub ...

1994-11-30

200

Dynamic behaviour of dc double anode plasma torch at atmospheric pressure  

International Nuclear Information System (INIS)

An original dc double anode plasma torch which provides a long-time and highly stable atmospheric plasma jet has been devised for the purpose of hazardous waste treatment. The arc fluctuations and dynamic behaviour of the argon and argon-nitrogen plasma jets under different operating conditions have been investigated by means of classical tools, such as the statistic method, fast Fourier transform (FFT) and correlation analysis. In our experiments, the takeover mode is identified as the fluctuation characteristic of the argon plasma jet while the restrike mode is typical in the argon-nitrogen plasma dynamic behaviour. In the case of pure argon, the FFT and correlation calculation results of electrical signals exhibit the only characteristic frequency of 150 Hz, which originates from the torch power and is independent of any change in the operating conditions. It indicates that the nature of fluctuations in an argon plasma jet is mainly induced ...

2007-07-07

201

Chemometric study of functional groups in Pennsylvanian gymnosperm plant organs (Sydney Coalfield, Canada): Implications for chemotaxonomy and assessment of kerogen formation  

Energy Technology Data Exchange (ETDEWEB)

The samples comprise the foliage of four pteridosperm-medullosalean plant fossil species of differing preservation states and one of a cordaitean species from two Canadian Maritime sub-basins of Carboniferous age (300 Ma; Sydney and Stellarton coalfields, Nova Scotia, respectively). Included in the sample set were some coal samples from Sydney Coalfield, along with published data for coal macerals for comparison. By applying Schulze's maceration process to the fossil foliage to obtain the cuticles, five sample forms evolved, viz. compressions, cuticles and fossilized cuticles, and acidic and alkaline solutions from Schulze's process, to which was added the Sydney coal samples as the sixth form. Area integration of the absorbance spectra from solid and liquid state Fourier transform infrared (FTIR) spectroscopy, produced functional chemical parameters which were organized into a data matrix of eight variables and 62 samples (8 ...

2010-12-15

202

CO{sub 2} bands in the 3350 - 3700 cm{sup {minus}1} spectral region: Ro-vibrational constants and absolute intensities  

Energy Technology Data Exchange (ETDEWEB)

Spectroscopic constants and absolute intensities from more than 2150 transitions belonging to 52 bands of 7 isotopic species of carbon dioxide have been determined using a multispectrum nonlinear least-squares fitting technique. The spectral data (0.01 cm{sup -1} resolution) were obtained at room temperature and low pressure (<10 Torr) using the McMath-Pierce Fourier transform spectrometer of the National Solar Observatory on Kitt Peak, Arizona. A natural sample of carbon dioxide with absorption path lengths between 24 and 385m were used in recording the spectra. The first measurements have been made of the theoretically predicted 2v{sub 2}{sup 2} 2+v{sub 3} {open_quotes}forbidden{close_quotes} band of {sup 12}CO{sub 2}. Two bands which have not been predicted so far, one belonging to {sup 13}CO{sub 2} and the other to {sup 13}C{sup 16}O{sup 18}O, have been identified. The measured line intensities obtained for each band have been analyzed ...

1995-12-31

203

Analysis of acidic compound classes in crude oil by negative ion electrospray ionization high resolution FT-ICR mass spectrometry  

Energy Technology Data Exchange (ETDEWEB)

Acidic constituents in crude oil are associated with the formation of stable emulsions during production and present a challenge for efficient oil recovery and processing. Acid molecules, including naphthenic acids and acidic sulfur in crude oil cause corrosion in refineries and pipelines. Naphthenic acids are also significant because of their surface activity and marginal water solubility, so that they may leach to wastewaters and cause adverse environmental effects. Acidic components of oil are not limited to carboxylic acids but also molecules that contain sulfur and nitrogen. As such, an improved understanding of the chemistry and physics of petroleum at the molecular level is needed in order to understand the range of problems associated with acidic oil components and to design better solutions. The applications of negative-ion electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) for ...

2008-07-01

204

A study of the reactions of ethanol on CeO{sub 2} and Pd/CeO{sub 2} by steady state reactions, temperature programmed desorption, and in situ FT-IR  

Energy Technology Data Exchange (ETDEWEB)

The reaction of ethanol on unreduced and H{sub 2}-reduced CeO{sub 2} and 1 wt% Pd/CeO{sub 2} has been investigated by steady state reactions, temperature programmed desorption (TPD), and in situ Fourier transform infrared (FT-IR) spectroscopy. Steady state reactions have shown a zero reaction order dependency for diatomic oxygen at and above 20%, while the addition of Pd to CeO{sub 2} decreases the apparent activation energy of the reaction from 75 kJ/mol on CeO{sub 2} alone to 40 kJ/mol (Pd/CeO{sub 2}). TPD experiments following ethanol adsorption on both CeO{sub 2} and Pd/CeO{sub 2} have shown desorption profiles corresponding to unreacted ethanol and various reaction and decomposition products (acetaldehyde, acetone, CO, CO{sub 2}, and methane). Ethanol conversion to reaction products was increased by the addition of Pd, from 15 to 30% on CeO{sub 2} and H{sub 2}-reduced CeO{sub 2}, to 71 and 63% on Pd/CeO{sub 2} and H{sub 2}-reduced ...

1999-09-10

205

The effects of temperature dependent viscosity and thermal conductivity on unsteady MHD convective heat transfer past a semi-infinite vertical porous moving plate with variable suction  

British Library Electronic Table of Contents (United Kingdom)

In this article, we studied the effects of variable viscosity and thermal conductivity on an unsteady two-dimensional laminar flow of a viscous incompressible conducting fluid past a semi-infinite vertical porous moving plate taking into account the effect of a magnetic field in the presence of variable suction. The fluid viscosity is assumed to vary as an inverse linear function of temperature but the thermal conductivity is assumed to vary as a linear function of temperature. It is assumed that the porous plate moves with a constant velocity in the direction of fluid flow, and the free stream velocity follows the exponentially increasing small perturbation law. The governing equations for the flow are transformed into a system of nonlinear ordinary differential equations by perturbation ...

2007-01-01

206

THE EFFECT OF VARIABLE THERMAL CONDUCTIVITY ON MICRO-POLAR FLUID FLOW BY CHEBYSHEV COLLOCATION METHOD  

British Library Electronic Table of Contents (United Kingdom)

In this article, the authors analyzed the effect of thermal conductivity on unsteady magnetohydrodynamic (MHD) free convection in a micro-polar fluid past a semi-infinite vertical porous plate. The fluid thermal conductivity is assumed to vary as a linear function of temperature. By using the Chebyshev collocation method in the spatial direction and the Crank-Nicolson method in the time direction, the boundary layer equations are transformed into a linear algebraic system. There are several material parameters whose affect on the flow have been studied, for instance, thermal conductivity, radiation, magnetic, micro-polar, suction (or injection) parameters, and Prandtl number. Boundary layer and Boussineq approximations have been introduced together to describe the flow field. The domain of...

2010-01-01

207

Planar QED at finite temperature and density: Hall conductivity, Berry's phases and minimal conductivity of graphene  

CERN Document Server

We study 1-loop effects for massless Dirac fields in two spatial dimensions, coupled to homogeneous electromagnetic backgrounds, both at zero and at finite temperature and density. In the case of a purely magnetic field, we analyze the relationship between the invariance of the theory under large gauge transformations, the appearance of Chern-Simons terms and of different Berry's phases. In the case of a purely electric background field, we show that the effective Lagrangian is independent of the chemical potential and of the temperature. More interesting: we show that the minimal conductivity, as predicted by the quantum field theory, is the right multiple of the conductivity quantum and is, thus, consistent with the value measured for graphene, with no extra factor of pi in the denominator.

2009-01-01

208

Overview of industrial applications of induction; L'induction au service de l'industrie: panorama des applications industrielles  

Energy Technology Data Exchange (ETDEWEB)

Because power requirements in induction heating applications are largely dependent on the physical properties of the product to be heated, inducting, heating is mainly used in steelwork applications, for the manufacture of finished or semi-finished parts. Applications here cover five main types of steelworks operation: smelting, heating prior to forming, heat treatment, surface treatment, and assembly process. At the same time, technological progress has opened up innovative applications in sectors such as chemical and agro-food industries. Other emerging applications for induction include direct forming of liquid metal, wholly or partially replacing mechanical transformations on solid metal. Techniques include electromagnetic forming, continuous cold-crucible casting, electromagnetic mixing, flow control by continuous magnetic field, and production of intense sliding fields (pumps, flow regulation). (author)

2004-05-01

209

Advances in amorphous and nanocrystalline magnetic materials  

International Nuclear Information System (INIS)

Recent advances made in the area of amorphous and nanocrystalline alloys exhibiting high saturation inductions are reviewed. A new chemical composition was identified that achieves a saturation induction of 1.64 T in an iron-based amorphous alloy. This alloy, when used in electrical transformers, shows a much improved performance over the existing amorphous alloy. Nanocrystalline FeCoCuNbSiB alloys are found to have saturation induction levels reaching 1.7 T. These materials are suited for use in sensors and inductors carrying large currents. Some of these nanocrystalline alloys show a BH squareness ratio exceeding 90%, which can be utilized in pulse power devices. Recent developments in the applications of these materials are also pointed out.

2006-09-01

211

Fourier duality as a quantization principle  

Energy Technology Data Exchange (ETDEWEB)

The Weyl-Wigner prescription for quantization on Euclidean phase spaces makes essential use of Fourier duality. The extension of this property to more general phase spaces requires the use of Kac algebras, which provide the necessary background for the implementation of Fourier duality on general locally groups. Kac algebras - and the duality they incorporate are consequently examined as candidates for a general quantization framework extending the usual formalism. Using as a test case the simplest non-trivial phase space, the half-plane, it is shown how the structures present in the complete-plane case must be modified. Traces, for example, must be replaced by their noncommutative generalizations - weights - and the correspondence embodied in the Weyl-Wigner formalism is no more complete. Provided the underlying algebraic structure is suitably adapted to each case, Fourier duality is shown to be indeed a very powerful ...

1996-08-01

212

Assessment of audible noise from high voltage transmission lines and a high voltage transformer station  

Energy Technology Data Exchange (ETDEWEB)

The study of audible noise from high voltage transmission lines and a high voltage transformer station was conducted in three parts. Part 1 consisted of long-term measurement and statistical analysis by computer reduction of audible noise as a result of corona discharge from high voltage transmission lines and the associated weather conditions which contribute to this noise. Recommendations are given concerning further computer programming in order to improve the statistical reliability of corona noise presence and reduce the degree of background noise contamination of the present results. Part 2 consisted of categorizing and cataloguing of corona noise spectra from long-term measurements on 550, 735 and 765 kV transmission lines and to provide a library of such sounds on magnetic tape to be used in the ongoing study of corona noise. Twenty-five different corona sound spectra have been identified and documented in a tape library. Average ...

1986-11-01

214

Dr Feynman's doodles: how one scientist's simple sketches transformed physics  

CERN Multimedia

Dr Feynman's doodles: how one scientist's simple sketches transformed physics

2005-01-01

215

Computer simulation of martensitic transformations  

Energy Technology Data Exchange (ETDEWEB)

The characteristics of martensitic transformations in solids are largely determined by the elastic strain that develops as martensite particles grow and interact. To study the development of microstructure, a finite-element computer simulation model was constructed to mimic the transformation process. The transformation is athermal and simulated at each incremental step by transforming the cell which maximizes the decrease in the free energy. To determine the free energy change, the elastic energy developed during martensite growth is calculated from the theory of linear elasticity for elastically homogeneous media, and updated as the transformation proceeds.

1993-11-01

216

Field driven ferromagnetic phase evolution originating from the domain boundaries in antiferromagnetically coupled perpendicular anitsotropy films  

Energy Technology Data Exchange (ETDEWEB)

Strong perpendicular anisotropy systems consisting of Co/Pt multilayer stacks that are antiferromagnetically coupled via thin Ru or NiO layers have been used as model systems to study the competition between local interlayer exchange and long-range dipolar interactions [1,2]. Magnetic Force Microscopy (MFM) studies of such systems reveal complex magnetic configurations with a mix of antiferromagnetic (AF) and ferromagnetic (FM) phases. However, MFM allows detecting surface stray fields only and can interact strongly with the magnetic structure of the sample, thus altering the original domain configuration of interest [3,4]. In the current study they combine magnetometry and state-of-the-art soft X-ray transmission microscopy (MXTM) to investigate the external field driven FM phase evolution originating from the domain boundaries in such antiferromagnetically coupled perpendicular anisotropy films. MXTM allows directly ...

2008-05-01

217

Energy flux operator, current conservation and the formal Fourier's law  

International Nuclear Information System (INIS)

By revisiting previous definitions, we show that one can define an energy current operator that satisfies the continuity equation for a general Hamiltonian in one dimension. This expression is useful for studying electronic, phononic and photonic energy flow in linear systems and in hybrid structures. The definition allows us to deduce the necessary conditions that result in current conservation for general-statistics systems. The discrete form of the Fourier's law of heat conduction naturally emerges in the present definition.

2009-01-16

218

Magnetic Levitation of MC3T3 Osteoblast Cells as a Ground-Based Simulation of Microgravity  

UK PubMed Central (United Kingdom)

Diamagnetic samples placed in a strong magnetic field and a magnetic field gradient experience a magnetic force. Stable magnetic levitation occurs when the magnetic force exactly counter balances...Full Text Available

2009-11-01

219

Refining the Magnetic Forming Capability.  

Science.gov (United States)

... Title : Refining the Magnetic Forming Capability. ... Abstract : The purpose of this project was to refine the in-house magnetic forming capability. ...

1972-04-01

221

BIOMAGNETIC RESPONSE OF SIMPLE BIOLOGICAL ...  

Science.gov (United States)

... Examples include magnetic forming tools, magnetic shielding, magnetohydrodynamic propulsion systems, and various magnetic containment ...

1970-01-01

222

/22k : - NASA Technical Reports Server  

Science.gov (United States)

in pulse applications such as magnetic forming. ... In magnetic-forming electric circuitry, the ..... Aspects of Electrohydraulic land Magnetic Forming. ...

223

Sulfur behavior in chemical looping combustion with NiO/Al{sub 2}O{sub 3} oxygen carrier  

Energy Technology Data Exchange (ETDEWEB)

Chemical looping combustion (CLC) is a novel technology where CO{sub 2} is inherently separated during combustion. Due to the existence of sulfur contaminants in the fossil fuels, the gaseous products of sulfur species and the interaction of sulfur contaminants with oxygen carrier are a big concern in the CLC practice. The reactivity of NiO/Al{sub 2}O{sub 3} oxygen carrier reduction with a gas mixture of CO/H{sub 2} and H{sub 2}S is investigated by means of a thermogravimetric analyzer (TGA) and Fourier Transform Infrared spectrum analyzer in this study. An X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and scanning electron microscope (SEM) are used to evaluate the phase characterization of reacted oxygen carrier, and the formation mechanisms of the gaseous products of sulfur species are elucidated in the process of chemical looping combustion with a gaseous fuel containing hydrogen sulfide. The results show that the rate of ...

2010-05-15

224

Fatty acid/poly(methyl methacrylate) (PMMA) blends as form-stable phase change materials for latent heat thermal energy storage  

Energy Technology Data Exchange (ETDEWEB)

Fatty acids such as stearic acid (SA), palmitic acid (PA), myristic acid (MA), and lauric acid (LA) are promising phase change materials (PCMs) for latent heat thermal energy storage (LHTES) applications, but high cost is the most drawback which limits the utility area of them in thermal energy storage. The use of fatty acids as form-stable PCM will increase their feasibilities in practical LHTES applications due to reduced cost of the energy storage system. In this regard, a series of fatty acid/poly(methyl methacrylate) (PMMA) blends, SA/PMMA, PA/PMMA, MA/PMMA, and LA/PMMA were prepared as new kinds of form-stable PCMs by encapsulation of fatty acids into PMMA which acts as supporting material. The blends were prepared at different mass fractions of fatty acids (50, 60, 70, 80, and 90% w/w) to reach maximum encapsulation ratio. All blends were subjected to leakage test by heating the blends over the melting temperature of the PCM. The blends that do not allow leakage of melted PCM ...

2008-02-15

225

MAGNETIC RESONANCE IMAGING DEVICE  

J-STORE (Japan)

Full Text Available

2010-08-31

226

Continuum damping of toroidal Alfven eigenmodes in finite-#beta# tokamak equilibria  

International Nuclear Information System (INIS)

A general theoretical approach for the study of the two-dimensional structure of high-n Toroidal Alfven Eigenmodes (TAE) in finite-#beta#, large aspect ratio (R_o/a much-gt 1) tokamak equilibria is presented. Here, n is the toroidal mode number, #beta# = plasma/magnetic pressure, and a(R_o) is the minor (major) radius of the torus. It is shown how the general pseudo-differential boundary value problem for the radial eigenmode structure can be systematically constructed from the local dispersion relation; which is obtained using the ballooning formalism. The TAE modes are characterized by a broad radial envelope, the width of which is independent on the mode number in the general case of monotonic equilibrium profiles. The results on the two-dimensional eigenmode structure are expected to be applicable to drift-type waves. The ballooning transform is generalized here to handle singular eigenfunctions typical of the continuous shear Alfven ...

227

Beam direct converter with varying magnetic field  

Energy Technology Data Exchange (ETDEWEB)

The concept of a direct energy recovery system that applies a varying magnetic field is proposed for a negative-ion-based neutral beam injection system (NNB) to heat a plasma and/or drive a plasma current in a fusion reactor. The output beam energy and power of such an NNB will be {approximately}1 MeV and {approximately}1- MW/beam-line, respectively, and nearly the same amounts of positive- and negative-ion beams remain unneutralized in an NNB by using a gas-neutralizing cell. Therefore, the output of a beam direct convertor in an NNB is a bipolar direct current (dc) electric power with close to {plus_minus} 1 MV and several amperes if a conventional electrostatic or magnetostatic field is applied for ion beam separation. However, such high-voltage dc power is difficult to handle at the point of the regeneration of the power back to a commercial electric line because a very high voltage inverter tough enough to withstand occasional sparkdowns at recovery electrodes ...

1994-12-01

228

Reduced-aspect-ratio stellarator reactors  

Energy Technology Data Exchange (ETDEWEB)

The extent to which the size of a modular stellarator reactor may be reduced is investigated by means of an analytic model of the reactor. The various means employed include varying the blanket/shield thickness, the power output and the wall loading. An optimum design is found, the major radius of which tends to be insensitive to changes in these quantities, although a decrease in the power output leads to a rather smaller decrease in reactor dimensions, as would be expected. Varying the plasma beta at fixed (iota/2..pi..)/sup 2/epsilon or, alternatively, increasing the rotational transform per field period, may, however, allow configurations with fewer field periods to be accessed which have a substantially smaller major radius than the 'standard case' adopted. The magnetics of various configurations required by the model are checked by field line following and the performance claimed is shown to be relatively easily ...

1984-01-01

229

Crystalline beam ground state  

Energy Technology Data Exchange (ETDEWEB)

In order to employ molecular dynamics (MD) methods, commonly used in condensed matter physics, we have derived the equations of motion for a beam of charged particles in the rotating rest frame of the reference particle. We include in the formalism that the particles are confined by the guiding and focusing magnetic fields, and that they are confined in a conducting vacuum pipe while interacting with each other via a Coulomb force. Numerical simulations using MD methods has been performed to obtain the equilibrium crystalline beam structure. The effect of the shearing force, centrifugal force, and azimuthal variation of the focusing strength are investigated. It is found that a constant gradient storage ring can not give a crystalline beam, but that an alternating-gradient (AG) structure can. In such a machine the ground state is, except for one-dimensional (1-D) crystals, time dependent. The ground state is a zero entropy state, despite the time-dependent, ...

1993-06-11

230

Specification of the steel sheet for the 300 GeV magnet system  

CERN Document Server

Specification of the steel sheet for the 300 GeV magnet system

1971-01-01

231

Radial Halbach Magnetic Bearings  

Science.gov (United States)

Radial Halbach magnetic bearings have been investigated as part of an effort to develop increasingly

2009-01-01

232

Magnetic phase transition in UPd_2Si_2  

International Nuclear Information System (INIS)

... fields magnetic moments neel temperature neutron diffraction order-disorder

233

Magnetic forming of resistive materials  

Science.gov (United States)

Necessary theoretical foundation is given for the treatment of magnetic stresses applied to

1969-01-01

234

Magnetic forming coil design and development summary report  

Science.gov (United States)

Magnetic forming coil design and development

1964-01-01

236

Large scale magnetic field measurements and mapping  

CERN Document Server

Large scale magnetic field measurements and mapping

1984-01-01

237

ELECTRICAL AND DIAGNOSTIC ASPECTS OF ELECTROHYDRAULIC AND MAGNETIC FORMING  

Science.gov (United States)

Discussion of an electrohydraulic and magnetic forming process

1963-01-01

239

Fourier analysis of energy transfer data obtained by simulating a 14-MeV #alpha#-particle in water  

International Nuclear Information System (INIS)

Data from Monte Carlo transport codes are used to model radiobiological effects. We previously reported the Fourier analysis of ionization data generated by simulating a 500-keV proton traversing water. Here, we extend Fourier analysis to energy transfer data of another radiation type, a 14-MeV #alpha#-particle. A radiobiological model based on this frequency-domain analysis views cell as an information processing system . It lends itself naturally to traditional engineering analyses. One engineering principle-the output response of a linear system to random signal-is applied here to explain the fact that there is measurable difference in the magnitude of the biological effectiveness when a given biological system is irradiated with two different radiation types of the same Linear Energy Transfer (LET).

2010-01-15

240

Application of Bayer red mud for iron recovery and building material production from alumosilicate residues  

Energy Technology Data Exchange (ETDEWEB)

Red mud is a solid waste produced in the process of alumina extraction from bauxite. In this paper, recovery iron from Bayer red mud was studied with direct reduction roasting process followed by magnetic separation, and then building materials were prepared from alumosilicate residues. After analysis of chemical composition and crystalline phase, the effects of different parameters on recovery efficiency of iron were carried out. The optimum reaction parameters were proposed as the following: ratio of carbon powder: red mud at 18:100, ratio of additives: red mud at 6:100, roasting at 1300 deg. C for 110 min. With these optimum parameters, total content of iron in concentrated materials was 88.77%, metallization ratio of 97.69% and recovery ratio of 81.40%. Then brick specimens were prepared with alumosilicate residues and hydrated lime. Mean compressive strength of specimens was 24.10 MPa. It was indicated that main mineral phase transformed ...

2009-01-15

241

Magnetic separation of antibiotics by electrochemical magnetic seeding  

Energy Technology Data Exchange (ETDEWEB)

Magnetic separation of several classes of antibiotics was investigated using electrochemical magnetic seeding. Electrocoagulation with a sacrificial anode followed by addition of magnetite particles was applied for the magnetic seeding of antibiotics. With electrochemical magnetic seeding using an iron anode, tetracycline antibiotics (oxytetracycline, chlortetracycline, doxycycline and tetracycline) and cephalosporin antibiotic (cefdinir) were rapidly removed from synthetic wastewater by magnetic separation using a neodymium magnet. Iron and aluminium anodes were suitable for magnetic seeding of the antibiotics. The results indicated that the ability of antibiotics to form strong complex with iron and aluminium allowed the higher removal by magnetic separation. This method would be appropriate for rapid treatment of ...

2009-03-01

242

Real time neutron transmission investigation of the austenite-bainite transformation in grey iron  

Energy Technology Data Exchange (ETDEWEB)

The first successful application of a new method to investigate phase transformations in real time, like the decomposition of austenite into bainite in grey iron, is described. During the ongoing transformation, transmission spectra of thermal neutrons, which contain Bragg edges corresponding to the crystal structure of the transforming phases, are recorded. By evaluating the height of these Bragg edges, which is a measure of the volume fraction of the phase, at different transformation times, the transformation can be followed in-situ in a time resolved manner. The method is compared to other previously used methods (micrographs, dilatometry, diffraction techniques); also a summary and an outlook are given. ((orig.))

1994-06-01

243

Real time neutron transmission investigation of the austenite-bainite transformation in grey iron  

International Nuclear Information System (INIS)

The first successful application of a new method to investigate phase transformations in real time, like the decomposition of austenite into bainite in grey iron, is described. During the ongoing transformation, transmission spectra of thermal neutrons, which contain Bragg edges corresponding to the crystal structure of the transforming phases, are recorded. By evaluating the height of these Bragg edges, which is a measure of the volume fraction of the phase, at different transformation times, the transformation can be followed in-situ in a time resolved manner. The method is compared to other previously used methods (micrographs, dilatometry, diffraction techniques); also a summary and an outlook are given. ((orig.)).

1994-01-01

244

Resolution enhancement by subtraction of confocal signals taken at different pinhole sizes.  

Science.gov (United States)

Subtractive imaging in confocal fluorescence light microscopy is based on the subtraction of a suitably weighted widefield image from a confocal image. An approximation to a widefield image can be obtained by detection with an opened confocal pinhole. The subtraction of images enhances the resolution in-plane as well as along the optic axis. Due to the linearity of the approach, the effect of subtractive imaging in Fourier-space corresponds to a reduction of low spatial frequency contributions leading to a relative enhancement of the high frequencies. Along the direction of the optic axis this also results in an improved sectioning. Image processing can achieve a similar effect. However, a 3D volume dataset must be acquired and processed, yielding a result essentially identical to subtractive imaging but superior in signal-to-noise ratio. The latter can be increased further with the technique of weighted averaging in Fourier-space. A comparison ...

2003-01-01

245

Global Environmental Data for Mapping Infectious Disease Distribution  

UK PubMed Central (United Kingdom)

This contribution documents the satellite data archives, data processing methods and temporal Fourier analysis (TFA) techniques used to create the remotely sensed datasets on the DVD distributed...Full Text Available

2006-01-01

246

Fourier-Domain Optical Coherence Tomography and Adaptive Optics Reveal Nerve Fiber Layer Loss and Photoreceptor Changes in a Patient With Optic Nerve Drusen  

UK PubMed Central (United Kingdom)

BackgroundNew technology allows more precise definition of structural alterations of all retinal layers although it has not been used previously in cases of optic...Full Text Available

2008-06-01

247

Transforming Civil Engineering. Air Force Civil Engineer ...  

Science.gov (United States)

... Civil Engineering Page 2. ... 4. TITLE AND SUBTITLE Transforming Civil Engineering (Air Force Civil Engineer, Volume 15, Number 1, 2007) 5a. ...

2011-05-14

248

Transformation of Verapamil by Cunninghamella blakesleeana  

UK PubMed Central (United Kingdom)

A filamentous fungus, Cunninghamella blakesleeana AS 3.153, was used as a microbial model of mammalian metabolism to transform verapamil, a calcium channel antagonist. The metabolites...Full Text Available

2004-05-01

249

Transformation by complementation of an adenine auxotroph of the lignin-degrading basidiomycete Phanerochaete chrysosporium  

Science.gov (United States)

Swollen basiodiospores of an adenine auxotroph of Phanerochaete chrysosporium were protoplasted with Novozyme 234 and transformed to prototrophy by using a plasmid containing the gene for an adenine biosynthetic enzyme from Schizophyllum commune. Transformation frequencies of 100 transformants per {mu}g of DNA were obtained. Southern blot analysis of DNA extracted from transformants demonstrated that plasmid DNA was integrated into the chromosomal DNA in multiple tandem copies. Analysis of conidia and basiodiospores from transformants demonstrated that the transforming character was mitotically and meiotically stable on both selective and nonselective media. Genetic crosses between double mutants transformed for adenine prototrophy and other auxotrophic strains yielded Ade{sup {minus}} progeny, which indicated that integration occurred at a ...

1989-02-01

250

The Challenges of Colorectal Cancer Survivorship  

UK PubMed Central (United Kingdom)

With advances in treatment, colorectal cancer is being transformed from a deadly disease to an illness that is increasingly curable. With this transformation has come increased interest in the...Full Text Available

2009-09-01

251

A fast multipole transformation for global climate calculations  

Energy Technology Data Exchange (ETDEWEB)

A fast multipole transformation is adapted to the evaluation of summations that occur in global climate calculations when transforming between spatial and spherical harmonic representations. For each summation, the timing of the fast multipole transformation scales linearly with the number of latitude gridpoints, but the timing for direct evaluations scales quadratically. In spite of a larger computational overhead, this scaling advantage renders the fast multipole method faster than direct evaluation for transformations involving greater than approximately 300 to 500 gridpoints. Convergence of the fast multipole transformation is accurate to machine precision. As the resolution in global climate calculations continues to increase, an increasingly large fraction of the computational work involves the transformation between spatial and spherical harmonic ...

1996-01-01

252

Fourier Synthesization of Optical Pulses and "Polar'' Light  

CERN Document Server

It is shown that the direct Fourier synthesization of light beams allows one to create polarity-asymmetric waves, which are able, in the process of nonlinear interaction with a medium, to break its inversion symmetry. As a result, these "polar" waves may show the effect of optical rectification in nonlinear centrosymmetric media by generating light-induced dc electric polarization. At the same time, the waves of this type, due to their unusual symmetry properties, can be used for detecting the direction and sign of a dc electric field applied to the medium. The prospects of application of polar waves to data recording and processing are discussed.

2002-01-01

253

Nanoscale microstructure and magnetic properties of melt-spun Sm(Co{sub 0.725}Fe{sub 0.1}Cu{sub 0.12}Zr{sub 0.04}B{sub 0.015}){sub 7.4} ribbons  

Energy Technology Data Exchange (ETDEWEB)

We have investigated the nanocrystalline microstructure and the hard magnetic properties of Sm(Co{sub 0.725}Fe{sub 0.1}Cu{sub 0.12}Zr{sub 0.04}B{sub 0.015}){sub 7.4} melt-spun ribbons. The coercivity (H{sub c}) of the as-spun ribbons increased with the wheel surface speed from 2.8kOe for 10m/s to 14.5kOe for 40m/s. The post-annealing of the melt-spun ribbons from 700 to 900 deg. C for 10min did not lead to a substantial increase of H{sub c}. However, after isothermal aging at 820 deg. C and subsequent slow cooling (0.5 deg. C/min) to 120 deg. C, H{sub c} increased from 2.8 to 10.9kOe for 10m/s, while it decreased from 14.5 to 13.5kOe for 40m/s ribbons. The grain size of the melt-spun ribbon reduced with structural transformation from 2:17H (Th{sub 2}Ni{sub 17}-hexagonal type) to 1:7H (TbCu{sub 7}-hexagonal type) as the wheel surface speed was increased. Three-dimensional atom probe analysis showed a boron enriched precipitate at the grain ...

2005-08-15

254

Nanoscale microstructure and magnetic properties of melt-spun Sm(Co_0_._7_2_5Fe_0_._1Cu_0_._1_2Zr_0_._0_4B_0_._0_1_5)_7_._4 ribbons  

International Nuclear Information System (INIS)

We have investigated the nanocrystalline microstructure and the hard magnetic properties of Sm(Co_0_._7_2_5Fe_0_._1Cu_0_._1_2Zr_0_._0_4B_0_._0_1_5)_7_._4 melt-spun ribbons. The coercivity (H_c) of the as-spun ribbons increased with the wheel surface speed from 2.8kOe for 10m/s to 14.5kOe for 40m/s. The post-annealing of the melt-spun ribbons from 700 to 900 deg. C for 10min did not lead to a substantial increase of H_c. However, after isothermal aging at 820 deg. C and subsequent slow cooling (0.5 deg. C/min) to 120 deg. C, H_c increased from 2.8 to 10.9kOe for 10m/s, while it decreased from 14.5 to 13.5kOe for 40m/s ribbons. The grain size of the melt-spun ribbon reduced with structural transformation from 2:17H (Th_2Ni_1_7-hexagonal type) to 1:7H (TbCu_7-hexagonal type) as the wheel surface speed was increased. Three-dimensional atom probe analysis showed a boron enriched precipitate at the grain boundaries in the as-spun ribbons, which acts ...

2005-08-01

255

Stability and disturbance of large dc superconducting magnets  

Energy Technology Data Exchange (ETDEWEB)

This paper addresses the stability aspects of several successful dc superconducting magnets such as large bubble chamber magnets, and magnets for the Mirror Fusion Test Facility and MHD Research Facility. Specifically, it will cover Argonne National Laboratory 12-Foot Bubble Chamber magnets, the 15-foot Bubble Chamber magnets at Fermi National Laboratory, the MFTF-B Magnet System at Lawrence Livermore National Laboratory, the U-25B Bypass MHD Magnet, and the CFFF Superconducting MHD magnet built by Argonne National Laboratory. All of these magnets are cooled in pool-boiling mode. Magnet design is briefly reviewed. Discussed in detail are the adopted stability critera, analyses of stability and disturbance, stability simulation, and the final results of magnet ...

1981-11-11

257

Magnetic braking of the rotation of molecular cloud cores  

International Nuclear Information System (INIS)

We investigate the magnetic braking of the core of an axisymmetric cloud whose rotation axis is parallel to the mean direction of the magnetic field. (author).

258

LHC magnet alignment  

CERN Document Server

Checks are performed on the alignment of the magnets in the LHC tunnel. It is vital that each magnet is placed exactly where it has been designed so that the path of the beam is precisely controlled.

2007-01-01

259

Density separation of materials by using magnetic fluids  

Energy Technology Data Exchange (ETDEWEB)

The magnetic fluid is a colloidal suspension of magnetite in kerosene, prepared by a low-cost process. Separation is accomplished in an open trough filled with magnetic fluid. A magnetic field is established in the fluid, by energizing an electromagnet having poles on each side of the trough. Due to the design of the magnet poles and air gaps, the magnetic field is strongest at the bottom, about 10,000 oersteds, and uniformly decreases in strength to about 2000 oersteds at the top of the fluid. Therefore, the magnetic field gradient increases with depth. The magnetic force attracts the entire separation medium (magnetic fluid) creating a reaction force of equal magnitude and acting in the opposite direction. This reaction created within a magnetic fluid/magnetic field combination ...

1980-03-01

260

Environmental trace gas analysis by proton-transfer-reaction mass spectrometry (PTR-MS)  

International Nuclear Information System (INIS)

The work presented here demonstrates the ability of proton-transfer-reaction mass spectrometry (PTR-MS) to perform fast-response measurements of volatile organic compounds (VOCs) (including methanol, acetonitrile, acetaldehyde, acetone, PAN-type compounds, alpha- and beta-pinene, nopinone and pinonaldehyde) at the pptv level and its versatile applicability in the field of environmental trace gas analysis. Laboratory and field experiments including various calibration techniques and intercomparisons with other measurement techniques such as gas chromatography, atmospheric pressure chemical ionization and Fourier transformation infrared spectroscopy were performed providing a first characterization of the PTR-MS instrument performance (sensitivity, detection limit, precision, accuracy). Typically a detection limit (S/N=2) of 50 pptv for a 10 s signal integration time, a precision of 5 % and an accuracy in the range between 10 and 25 % were ...

266

Off-line and on-line-monitoring of power transformers using the transfer function method  

Energy Technology Data Exchange (ETDEWEB)

The transfer function concept is well known as an additional method to evaluate the impulse test of power transformers in the test laboratory. Another application for the transfer function method is monitoring of transformers in service. Thereby, Off-line and On-line monitoring can be realized. Both kinds of monitoring are demonstrated with on-site measurements on a power transformer in service.

1996-12-31

270

Cell culture systems to study glial transformation  

Energy Technology Data Exchange (ETDEWEB)

The transformation of two different types of glial cells has been studied using an in vivo-/in vitro model and a complete in vitro model. The purpose of the study and to define in vitro model systems is to study the the neoplastic transformation of pure populations of glial cells. Data are presented to demonstrate that the transformed cells are glial and tumorigenic. (ACR)

1980-01-01

271

Rough surface  

International Nuclear Information System (INIS)

For the determination of the thermal-hydraulic performances of rough surfaces, the method of evaluation is particularly important. In order to increase confidence in the results, a new evaluation procedure was introduced. This procedure is based on the transformation of simple channel experimental results to equal boundary conditions, and on the suitable application and confirmation of these transformed values in more complicated flow channel geometries. Existing methods, applied to the results obtained in an annular channel, do not fulfil all the transformation requirements. Thus a new, more complete transformation method, which uses the turbulent eddy diffusivity model, was developed. To check the quality of this transformation, within the scope of the new evaluation procedure, the results of experimental investigation in annular channels and in a bundle of hexagonal geometry were ...

2009-08-01

272

On the Potential for Vacancy Annihilation as a Mechanism for Conditioning in Pu-1.9 at.% Ga  

Energy Technology Data Exchange (ETDEWEB)

The {delta} {yields} {alpha}{prime} martensitic transformation in Pu-1.9 at.% Ga occurs when the alloy is cooled below about -100 C. This transformation exhibits anomalous behavior, where the isothermal transformation proceeds atypically with double-C kinetics. Recent work has revealed that an ambient temperature isothermal hold (referred to as conditioning) prior to the transformation has different effects depending on whether transformation proceeds in the upper- or lower-C of the double-C: the amount of transformation is increased with conditioning in the upper-C, while the transformation in the lower-C seems to be engendered by conditioning. The mechanism by which conditioning affects the low-temperature {delta} {yields} {alpha}{prime} transformation is thus of great importance to understanding the ...

2009-03-09

273

Physical and optical properties of rare earth cobalt magnets  

Energy Technology Data Exchange (ETDEWEB)

Rare Earth Cobalt (REC) permanent magnets have unique properties that permit solutions to some optical tasks that cannot be accomplished with conventional magnets. A review of design and of performance characteristics of these magnets includes an analytical description of the three dimensional fringe fields of REC quadrupoles.

1980-08-01

279

METHOD OF FORMING THIN MAGNETIC FILM  

J-STORE (Japan)

Full Text Available

2007-10-04

285

High pressure study of AlP: Transformation to a metallic NiAs phase  

Science.gov (United States)

The crystal structure and optical reflectivity of AlP has been studied in a diamond anvil cell using energy dispersive x-ray diffraction to 43 GPa and micro-optical reflectance spectroscopy to 36 GPa. AlP undergoes a first order phase transformation from zincblende to a NiAs structure which exhibits metallic reflectivity in the near-infrared. The decrease in volume on transformation is 17%[plus minus]1%. The transformation is reversible but has large hysteresis. The equilibrium transformation pressure is 9.5[plus minus]5 GPa.

1994-12-01

286

Extended covariance under nonlinear canonical transformation in Weyl quantization  

CERN Document Server

A theory of nonunitary-invertible as well as unitary canonical transformations is formulated in the context of Weyl's phase space representations. Exact solutions of the transformation kernels and the phase space propagators are given for the three fundamental canonical maps as fractional-linear, gauge and contact (point) transformations. Under the nonlinear maps a phase space representation is mapped to another phase space representation thereby extending the standard concept of covariance. This extended covariance allows Dirac-Jordan transformation theory to naturally emerge from the Hilbert space representations in the Weyl quantization.

2000-01-01

287

NASA TECH BRIEF  

Science.gov (United States)

Magnetic Forming Studies. The use of transient high magnetic-field devices has made possible the generation of very large accurately ...

289

Magnetic properties of single crystalline RE_2PdSi_3 intermetallic compounds  

International Nuclear Information System (INIS)

... susceptibility magnetization magnetoresistance monocrystals order-disorder

290

Finite Element Analysis of Magnetoelastic Plate Problems.  

Science.gov (United States)

... in the design of such devices as fusion reactors, magnetohydrodynamic generators, magnetically levitated vehicles, magnetic forming devices, and ...

1981-08-01

291

Design of a kW, DC Magnetically Contained Electrothermal ...  

Science.gov (United States)

... magnetic containment field lines which is zero on the center line of the toroidal containment tube and increases in magnitude with ...

1988-07-01

292

An investigation of the decoupling effects in a magnetic forming beryllium coil assembly.  

Science.gov (United States)

Decoupling force exerted by magnetic forming Be coil assembly on metallic plate during forming

1968-01-01

294

Progress of magnetic-suspension systems and magnetic bearings in the USSR  

International Nuclear Information System (INIS)

This paper traces the development and progress of magnetic suspension systems and magnetic bearings in the USSR. The paper describes magnetic bearings for turbomachines, magnetic suspension systems for vibration isolation, some special measuring devices, wind tunnels, and other applications. The design, principles of operation, and dynamic characteristics of the system are presented.

1992-05-01

295

International Symposium on Magnetic Suspension Technology. Part 2  

International Nuclear Information System (INIS)

In order to examine the state of technology of all areas of magnetic suspension and to review related recent developments in sensors and controls approaches, superconducting magnet technology, and design/implementation practices, a symposium was held. The proceedings are presented. The sessions covered the areas of bearings, sensors and controls, microgravity and vibration isolation, superconductivity, manufacturing applications, wind tunnel magnetic suspension systems, magnetically levitated trains (MAGLEV), space applications, and large gap magnetic suspension systems.

1991-08-19

296

Design of a magnetic braking system  

International Nuclear Information System (INIS)

A non-contact method, using magnetic drag force principle, was proposed to design the braking systems to improve the shortcomings of the conventional braking systems. The extensive literature detailing all aspects of the magnetic braking is briefly reviewed, however little of this refers specifically to upright magnetic braking system, which is useful for industries. One of the major issues to design upright magnetic system is to find out the magnetic flux. The changing magnetic flux induces eddy currents in the conductor. These currents dissipate energy in the conductor and generate drag force to slow down the motion. Therefore, a finite element model is developed to analyze the phenomena of magnetic flux density when air gap and materials of track are varied. The verification shows the predicted magnetic flux is within ...

2006-09-01

297

Texture transformations in thermomechanically treated steels having increased nitrogen content and alloys  

International Nuclear Information System (INIS)

In this study the results of mathematical simulation and experimental research of texture transition in stress assisted shear phase transformations are discussed. The orientation distribution function (ODF) calculation model to the any type crystalline lattice symmetry materials has been suggested. By crystalline lattice symmetry analysis this computer program determines necessary amount of the initial experimental data. The experimental verification supports this model well. The ODF calculation model after shear phase transformation with equal use of all possible variants of orientation relationship or with various degrees of variant selection worked out. In this study the experimental and calculating data of the direct and reversal shear transformations #alpha# <=> #gamma# in Fe-alloys and B2 <=> B19' in Ti-Ni alloys are discussed. The stress assisted shear phase transformation model and ...

298

Investigation of the austenite-bainite transformation in gray iron using real time neutron transmission  

Energy Technology Data Exchange (ETDEWEB)

In globulitic gray iron (3.6 wt.% C, 2.4 wt.% Si and 0.45 wt.% Mn) the decomposition of austenite into bainite is investigated in real time using a new method based on neutron scattering. During the phase transformation transmission spectra of thermal neutrons are continuously recorded containing specific Bragg edges. Thus, the transformation is followed in-situ time resolved by evaluating the relative (micro)structural fractions of the transforming phases from the heights of the corresponding Bragg edges. The progression of the transformation is described and the results are discussed. The observed late time deviations from the Avrami law are explained by residual stresses of the second kind (homogeneous microstresses), which occur during the transformation because of the different specific volumes of the phases. ((orig.))

1994-11-30

299

Investigation of the austenite-bainite transformation in gray iron using real time neutron transmission  

International Nuclear Information System (INIS)

In globulitic gray iron (3.6 wt.% C, 2.4 wt.% Si and 0.45 wt.% Mn) the decomposition of austenite into bainite is investigated in real time using a new method based on neutron scattering. During the phase transformation transmission spectra of thermal neutrons are continuously recorded containing specific Bragg edges. Thus, the transformation is followed in-situ time resolved by evaluating the relative (micro)structural fractions of the transforming phases from the heights of the corresponding Bragg edges. The progression of the transformation is described and the results are discussed. The observed late time deviations from the Avrami law are explained by residual stresses of the second kind (homogeneous microstresses), which occur during the transformation because of the different specific volumes of the phases. ((orig.)).

1994-11-01

300

Magnetization reversal phenomena and domain wall behaviours in nanostructured magnetic systems  

International Nuclear Information System (INIS)

Several recent experiments on micro- (or nano-) structured samples of ferromagnetic materials are introduced. Magnetization reversal phenomena are investigated on submicron wire samples of trilayer structure using the giant magnetoresistance effect. Domain wall movements are sensitively monitored by resistivity measurements and the velocity of propagation is determined. The contribution of domain wall to the resistivity is argued from the results on artificially designed samples of a spring-magnet system. In circular dots of permalloy, the existence of vortex magnetization is confirmed and the reversal of the vortex core magnetization is studied from magnetic force microscopy measurements. (author)

2001-09-23

301

Magnetic fluctuation measurement in Sino United Spherical Tokamak plasma  

International Nuclear Information System (INIS)

To investigate the magnetic fluctuations and for further transport study, the poloidal and radial magnetic field measurement is conducted on the Sino United Spherical Tokamak (SUNIST). Auto-power spectral density indicates that the magnetic fluctuation energy mainly concentrates in the frequency region lower than 10 kHz. The magnetic field oscillations, which are characterized by harmonic frequencies of 40 kHz, are observed in the scrape-off layer; by contrast, in the plasma core, the magnetic fluctuations are of Gaussian type. The time-frequency profiles show that the poloidal magnetic fluctuations are temporally intermittent. The autocorrelation calculation indicates that the fluctuations in decorrelation time vary between the core and the edge. (authors)

2007-07-01

302

Non-isothermal Smoluchowski-Poisson equations as a singular limit of the Navier-Stokes-Fourier-Poisson system  

British Library Electronic Table of Contents (United Kingdom)

ResumeLa convergence des solutions faibles du systeme de Navier-Stokes-Fourier-Poisson compressible avec un terme de frottement est etudiee dans la limite dun frottement infini, la loi de pression incluant, comme cas particulier, celle correspondant aux particules de Fermi-Dirac. La limite se trouve etre une solution faible dun systeme de Smoluchowski-Poisson non isotherme, la temperature ne dependant que de la variable temporelle et etant determinee par la conservation de lenergie totale.

2007-01-01

303

Multifractal Fourier detrended cross-correlation analysis of traffic signals  

Science.gov (United States)

Multifractal detrended cross-correlation analysis (MF-DXA) has been developed to detect the long-range power-law cross-correlation of considered signals in the presence of non-stationarity. However, crossovers arising from extrinsic periodic trends make the scaling behavior difficult to analyze. We introduce a Fourier filtering method to eliminate the trend effects and systematically investigate the multifractal cross-correlation of simulated and real traffic signals. The crossover locations are found approximately corresponding to the periods of underlying trend. Traffic velocity on one road and flows on adjacent roads show strong cross-correlation. They also present weak multifractality after periodic trends are removed. The traffic velocity and flow are cross-correlated in opposite directions which is accordant to their actual evolution.

2011-10-01

304

Synthesis, structure and characterisation of the n=4 Aurivillius phase Bi5Ti3CrO15  

International Nuclear Information System (INIS)

The n=4 Aurivillius phase, Bi5Ti3CrO15, was synthesised by solid state reaction. Rietveld analysis of high resolution neutron diffraction data demonstrated this material to adopt the polar space group A21am at room temperature, transforming to the aristotype I4/mmm structure above 650 oC. This phase transition is coincident with an anomaly in DSC signal and relative permittivity, which are characteristic of a ferroelectric-paraelectric phase transition. Bi5Ti3CrO15 exhibits paramagnetic behaviour at low temperature, with short range antiferromagnetic interactions, but no evidence for long range magnetic ordering. This is considered a consequence of significant disorder of Ti and Cr over the available octahedral sites, as demonstrated by analysis of neutron diffraction data. -- Graphical abstract: We report here the synthesis, structure and characterisation of the n=4 Aurivillius phase Bi5Ti3CrO15. Analysis of neutron powder diffraction and ...

2011-02-01

305

Process-integrated online monitoring of safety-relevant aluminum airbag pressure vessel components for a combined defect detection and material property determination by using contactless NDT (EMUS and EC)  

Energy Technology Data Exchange (ETDEWEB)

Airbag pressure vessels for the north-American market mainly are made by forging and by the use of steel alloys. In Europe aluminum alloys are common and the manufacturing process is extrusion of circular blanks - made from cold rolled plates - in a form applying a 100 t press at room temperature. Then by heat treatment the strength/hardness of the material is properly adjusted and after that the pressure vessel parts have to be continuously inspected with an inspection and handling cycle time of 3 s. Inspection of the axis-symmetric parts is asked for surface breaking extrusion defects as well as for surface parallel delaminations in the bulk volume. Furthermore, the material strength is a quality characteristic that has to be nondestructively registered and documented. The inspection is performed by eddy current probes and an EMAT, of which the eddy current impedance measurements are used for surface breaking extrusion defect detection and sizing (single frequency technique with ...

1999-07-01

306

Damping of toroidal ion temperature gradient modes  

Energy Technology Data Exchange (ETDEWEB)

The temporal evolution of linear toroidal ion temperature gradient (ITG) modes is studied based on a kinetic integral equation including an initial condition. It is shown how to evaluate the analytic continuation of the integral kernel as a function of a complex-valued frequency, which is useful for analytical and numerical calculations of the asymptotic damping behavior of the ITG mode. In the presence of the toroidal {nabla}B-curvature drift, the temporal dependence of the density and potential perturbations consists of normal modes and a continuum mode, which correspond to contributions from poles and from an integral along a branch cut, respectively, of the Laplace-transformed potential function of the complex-valued frequency. The normal modes have exponential time dependence with frequencies and growth rates determined by the dispersion relation while the continuum mode, which has a ballooning structure, shows a power law decay {proportional_to} t{sup -2} in ...

1999-04-01

307

Construction, testing of the 1 MW, 130-260 GHz Fusion-FEM  

Energy Technology Data Exchange (ETDEWEB)

During the previous 9 months the major part of the Fusion-FEM has been constructed. The 2 MV Insulated Core Transformer, the electron gun, the accelerator, the focusing lenses and the undulator have been tested on-site. In the present - temporary - set-up, the electron beam line consists of a 12 A, 80 keV thermionic electron gun, a 2 MeV dc accelerator, beam transport optics, the undulator and a collector. The gun is mounted in the high voltage terminal, which is now at -2 MV, and the undulator and mm-wave system am at ground potential outside the SF{sub 6}-filled pressure tank. This so-called inverse set-up allows easy access to the larger part of the beam line, the undulator and the mm-wave system, which is important in the conditioning phase. The decelerator and depressed collector am not yet installed. The design of the electron beam line has been optimised using the GPS particle-tracking code and the TOSCA code. The TOSCA code is used for accurate field ...

1995-12-31

308

Three-dimensional simulation study of compact toroid plasmoid injection into magnetized plasmas  

Energy Technology Data Exchange (ETDEWEB)

Three-dimensional dynamics of a compact toroid (CT) plasmoid, which is injected into a magnetized target plasma region is investigated by using magnetohydrodynamic (MHD) numerical simulations. It is found that the process of the CT penetration into this region is much more complicated than what has been analyzed so far by using a conducting sphere (CS) model. The injected CT suffers from a tilting instability, which grows with the similar time scale as the CT penetration. The instability is accompanied by magnetic reconnection between the CT magnetic field and the target magnetic field, which disrupts the magnetic configuration of the CT. Magnetic reconnection plays a role to supply the high density plasma initially confined in the CT magnetic field into the target region. Also, the penetration depth of the CT high density plasma is ...

1999-04-01

309

Neutron magnetic scattering studies on ferromagnetism in potassium nanoclusters arrayed in zeolite A-Trial experiments  

Energy Technology Data Exchange (ETDEWEB)

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

2009-02-21

310

Neutron magnetic scattering studies on ferromagnetism in potassium nanoclusters arrayed in zeolite A-Trial experiments  

International Nuclear Information System (INIS)

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

2009-02-21

311

[Malignant transformation of human fibroblasts by neutrons and by gamma radiation: Relationship to mutations induced  

Energy Technology Data Exchange (ETDEWEB)

A brief overview if provided of selected reports presented at the International Symposium on Molecular Mechanisms of Radiation- and Chemical Carcinogen-Induced Cell Transformation held at Mackinac Island, Michigan on September 19-23, 1993.

1993-12-31

312

Vectors containing a prokaryotic dihydrofolate reductase gene transform Drosophila cells to methotrexate-resistance.  

UK PubMed Central (United Kingdom)

Transformed Drosophila Kc cell lines, resistant to methotrexate, an inhibitor of de novo purine and pyrimidine synthesis, have been obtained by calcium phosphate transfection of plasmids containing...Full Text Available

1983-01-01

313

Transforming growth factor-?1 induces intestinal myofibroblast differentiation and modulates their migration  

UK PubMed Central (United Kingdom)

AIM: To investigate the effects of transforming growth factor β1 (TGF-β1) on the differentiation of colonic lamina propria fibroblasts (CLPF) into myofibroblasts in vitro.METHODS:...Full Text Available

2009-03-28

314

Product toxicity and cometabolic competitive inhibition modeling of chloroform and trichloroethylene transformation by methanotrophic resting cells.  

UK PubMed Central (United Kingdom)

The rate and capacity for chloroform (CF) and trichloroethylene (TCE) transformation by a mixed methanotrophic culture of resting cells (no exogenous energy source) and formate-fed cells were measured....Full Text Available

1991-04-01

315

Move or Die: the Fate of the Tax Oncoprotein of HTLV-1  

UK PubMed Central (United Kingdom)

The HTLV-1 Tax protein both activates viral replication and is involved in HTLV-1-mediated transformation of T lymphocytes. The transforming properties of Tax include altering the expression of select...Full Text Available

316

Modulating factors in the expression of radiation-induced oncogenic transformation  

Energy Technology Data Exchange (ETDEWEB)

Many assays for oncogenic transformation have been developed ranging from those in established rodent cell lines where morphological alteration is scored, to those in human cells growing in nude mice where tumor invasiveness is scored. In general, systems that are most quantitaive are also the least relevant in terms of human carcinogenesis and human risk estimation. The development of cell culture systems has made it possible to assess at the cellular level the oncogenic potential of a variety of chemical, physical and viral agents. Cell culture systems afford the opportunity to identify factors and conditions that may prevent or enhance cellular transformation by radiation and chemicals. Permissive and protective factors in radiation-induced transformation include thyroid hormone and the tumor promoter TPA that increase the transformation incidence for a given dose of radiation, and retinoids, ...

1990-08-01

317

Modulating factors in the expression of radiation-induced oncogenic transformation  

International Nuclear Information System (INIS)

Many assays for oncogenic transformation have been developed ranging from those in established rodent cell lines where morphological alteration is scored, to those in human cells growing in nude mice where tumor invasiveness is scored. In general, systems that are most quantitaive are also the least relevant in terms of human carcinogenesis and human risk estimation. The development of cell culture systems has made it possible to assess at the cellular level the oncogenic potential of a variety of chemical, physical and viral agents. Cell culture systems afford the opportunity to identify factors and conditions that may prevent or enhance cellular transformation by radiation and chemicals. Permissive and protective factors in radiation-induced transformation include thyroid hormone and the tumor promoter TPA that increase the transformation incidence for a given dose of radiation, and retinoids, ...

1990-01-01

318

Identification of the Neoplastically Transformed Cells in Marek's Disease Herpesvirus-Induced Lymphomas: Recognition by the Monoclonal Antibody AV37  

UK PubMed Central (United Kingdom)

Understanding the interactions between herpesviruses and their host cells and also the interactions between neoplastically transformed cells and the host immune system is fundamental to understanding...Full Text Available

2002-07-01

319

IEC steps up work on power transformers  

Energy Technology Data Exchange (ETDEWEB)

The technical committees of the International Electrotechnical Committee (IEC) play an important part in preparing international standards. In this report the chairman of the Technical Comittee 14 (Power Transformers) describes the present state and the progressive work.

1981-03-01

320

Factors Influencing the Tissue Culture and the Agrobacterium tumefaciens-Mediated Transformation of Hybrid Aspen and Poplar Clones  

UK PubMed Central (United Kingdom)

Tissue culture conditions and transformation have been established for both aspen and poplar. The use of previously described culture conditions resulted in shoot tip necrosis in the shoot cultures...Full Text Available

1990-07-01

321

Construction of DNA recognition sites active in Haemophilus transformation.  

UK PubMed Central (United Kingdom)

Competent Haemophilus cells recognize and preferentially take up Haemophilus DNA during genetic transformation. This preferential uptake is correlated with the presence on incoming DNA of an 11-base-pair...Full Text Available

1982-04-01

322

A plausible model for reversal of neoplastic transformations in plants based on multiple steady states.  

UK PubMed Central (United Kingdom)

We offer a plausible interpretation of some experiments on the reversal of neoplastic transformations in plants. We suggest that normal cells and tumorous cells represent multiple stable-steady states...Full Text Available

1991-12-01

323

Spin-resolved magnetic studies of focused ion beam etched nano-sized magnetic structures  

International Nuclear Information System (INIS)

Scanning ion microscopy with polarization analysis (SIMPA) is used to study the spin-resolved surface magnetic structure of nano-sized magnetic systems. SIMPA is utilized for in situ topographic and spin-resolved magnetic domain imaging as well as for focused ion beam (FIB) etching of desired structures in magnetic or non-magnetic systems. Ultra-thin Co films are deposited on surfaces of Si(1 0 0) substrates, and ultra-thin, tri-layered, bct Fe(1 0 0)/Mn/bct Fe(1 0 0) wedged magnetic structures are deposited on fcc Pd(1 0 0) substrates. SIMPA experiments clearly show that ion-induced electrons emitted from magnetic surfaces exhibit non-zero electron spin polarization (ESP), whereas electrons emitted from non-magnetic surfaces such as Si and Pd exhibit zero ESP, which can be used to calibrate sputtering rates in situ. We ...

2005-04-01

324

Magnetic properties of materials  

Energy Technology Data Exchange (ETDEWEB)

A number of interactions between magnetic fields and matter is reviewed. The resulting forces range in magnitude from the very large, obtained in high-energy fields, to the weak ones caused by the magnetostriction of ferromagnets. The fundamentals of these interactions are highlighted, and the examples discussed are forces on dipoles, particle alignment, magnetostrictive forces, magnetic forming, magnetic stirring, levitation melting, and magnetic pulsing of tool steels. (orig.)

2000-08-15

325

Magnetic flocculation and filtration  

Energy Technology Data Exchange (ETDEWEB)

A model is available in predicting flocculation frequencies between particles of various properties under the influence of a magnetic field. This model provides a basic understanding of fundamental phenomena, such as particle-particle and particle-collector interactions, occurring in HGMF (high gradient magnetic field), and will be extended to describe experimental data of particle flocculation and filtration and predict the performance of high- gradient magnetic filters. It is also expected that this model will eventually lead to a tool for design and optimization of magnetic filters for environmental, metallurgical, biochemical, and other applications.

1996-10-01

326

Transformational Satellite (TSAT) Communications Systems. ...  

Science.gov (United States)

... The seven existing space/airborne programs are the Defense Satellite Com- munications System (DSCS), Milstar, communications re- lay ...

2007-07-01

327

The effect of oxide inclusions on the kinetics of the austenite to ferrite transformation in low alloy steel weld metal  

Energy Technology Data Exchange (ETDEWEB)

Isothermal transformation kinetics of austenite to acicular ferrite and allotriomorphic ferrite were measured in reheated low alloy steel weld deposits with similar weld compositions and austenite grain size but different inclusion characteristics. Accelerated kinetics of transformation to acicular ferrite were observed in weld metal containing coarser and titanium-rich inclusions. In contrast, kinetics of transformation to allotriomorphic ferrite were not influenced by inclusion characteristics, but, rather, by the austenite grain size and carbon concentration.

1994-09-01

328

Problem Definition Studies on Potential Environmental ...  

Science.gov (United States)

... mutagenic, while two potential environmental transformation products, 1,4- diaminoanthraq Ynone and 1,4-dihydroxyanthraquinone are strongly ...

1979-11-01

329

From Service Operational Headquarters to Joint Task Force ...  

Science.gov (United States)

... directed the transformation of designated Service operational headquarters into effective and scalable Joint Task Force headquarters capable of ...

2007-04-27

330

Ensemble Forecasting with the Ensemble Transform Kalman ...  

Science.gov (United States)

... of these points corresponds to the ( " 2) term in ... (d) is identical to the 1-sigma ellipse corresponding ... A new approach to linear filtering and predicted ...

2004-08-01

331

EMITTANCE AND ABSORPTANCE OF NASA CERAMIC ...  

Science.gov (United States)

... The data were transformed into total hemispherical emittance values and correlated with respect to ceramic coating thickness and temperature ...

1978-06-01

332

Devolution through Transformation  

Science.gov (United States)

... Training System (JMATS) for joint C-130J training. However, the ... the C-130J's being procured by the Air Force. A logical ...

2011-05-14

334

Annual Industrial Capabilities Report to Congress  

Science.gov (United States)

... Transforming the NDS into a Strategic Materials Security Program (SMSP), a more comprehensive and flexible risk management process would ...

2010-05-01

337

Type I (RI) and type II (RII) receptors for transforming growth factor-beta isoforms are expressed subsequent to transforming growth factor-beta ligands during excisional wound repair.  

UK PubMed Central (United Kingdom)

Transforming growth factor (TGF)-beta isoforms (TGF-beta 1, -beta 2, and -beta 3) regulate cell growth and differentiation and have critical regulatory roles in the process of tissue repair and remodeling....Full Text Available

1997-01-01

338

Transformation Isotherme beta to alpha Dans L 'uranium Pur et Faiblement Allie (Beta to alpha Isothermal Transformation in Pure and Weakly Alloyed Uranium).  

Science.gov (United States)

The TTT diagrams describing the beta to alpha isothermal transformation have been made by isothermal dilatometry for pure uranium and 21 alloys based on chromium, silicon, molybdenum, iron, aluminium, zirconium. The thermal cycle preceeding the isothermal...

1966-01-01

339

Reduction of wave-function which transforms as field associated with spin zero tachyons  

International Nuclear Information System (INIS)

Reduction of wavefunction which transforms as scalar field imaginary mass system has been derived in terms of irreducible representation of proper, orthochronous, inhomogeneous Lorentz group and it has been shown that only transformation properties of wavefunction are needed in the derivation while the reality condition and wave equations only restrict the number of independent representations. The properties of energy and momentum of tachyons have been analysed and it has been shown that the tachyons are unidirectional in space. (author).

340

A new unified approach to bradyons and tachyons by conformal transformations  

International Nuclear Information System (INIS)

By using linearized conformal transformations in six dimensions, a new unified approach to bradyons (v"2< c"2) and tachyons (v"2>c"2) is suggested, the essential tool being (real and imaginary) dilatations. The usual ''Generalized Lorentz transformations'' are got, In six dimensions the quadrate form is always positive, both for bradyons and for tachyons.

341

Tachyons and the radiation of an accelerated charge  

Energy Technology Data Exchange (ETDEWEB)

The motion of an accelerated charge in a vacuum is analyzed, via the superposition principle and Fourier analysis, into uniform-motion components, which include bradyonic as well as tachyonic contributions. It is shown that the former contribute only to the induction fields whereas the latter are the source of the radiation emitted by the charge, via the Sommerfeld-Cerenkov mechanism. This result calls for a reexamination of some recently formulated theories of superluminal particles.

1982-10-15

342

Study of both nature and topology of the nano-porous materials by the positron annihilation spectroscopy  

International Nuclear Information System (INIS)

By the methods of the angular distribution of photon annihilation, time distribution of photon annihilation, photoluminescence spectroscopy, Fourier IR-spectroscopy, atomic force microscopy the detail information on relation of the structural and physical properties of the porous nano-structures is obtained. Study of pores sizes in a different nano-porous materials, such as the porous silicon, porous anode aluminium oxide, porous solids exposed to light atoms ion implantation (hydrogen, deuterium, helium) is carried out.

2003-09-15

343

Predictive wavefront control for Adaptive Optics with arbitrary control loop delays  

Energy Technology Data Exchange (ETDEWEB)

We present a modification of the closed-loop state space model for AO control which allows delays that are a non-integer multiple of the system frame rate. We derive the new forms of the Predictive Fourier Control Kalman filters for arbitrary delays and show that they are linear combinations of the whole-frame delay terms. This structure of the controller is independent of the delay. System stability margins and residual error variance both transition gracefully between integer-frame delays.

2007-10-30

344

Optical measurement of electron bunching in vacuum  

International Nuclear Information System (INIS)

We report the homodyne detection of phase modulation sidebands induced on a laser beam by a coherently bunched electron beam. This provides a sensitive and nonperturbing measurement of complex Fourier time series components of the electron density. A proof-of-principle measurement of the microwave frequency component of electron density in a crossed-field device, which agrees well with a calculation of the same quantity, is reported.

345

Experience with a digital noise analysis system in subcriticality measurements on a mockup of the FFTF  

Science.gov (United States)

From nuclear science symposium; San Francisco, California, USA (14 Nov 1973). A digital Fourier analyzer was programmed to perform reactor neutron noise analysis measurements and on-line processing of the data to obtain the steady-state reactivity. The system is suitable for recovering cross spectral density with low correlatedsignal component and for repetitive measurements with efficient use of reactor time. (auth)

1973-01-01

346

The effective longitudinal dielectric constant for plasmas in inhomogeneous magnetic fields  

Scientific Electronic Library Online (English)

Abstract in english We present a detailed derivation of the effective dielectric constant to be used in the dispersion relation for electrostatic waves in the case of a plasma immersed in a inhomogeneous magnetic field, with inhomogeneity perpendicular to the direction of the magnetic field.

2004-09-01

347

Magnetic mirror fusion systems: Characteristics and distinctive features  

Energy Technology Data Exchange (ETDEWEB)

A tutorial account is given of the main characteristics and distinctive features of conceptual magnetic fusion systems employing the magnetic mirror principle. These features are related to the potential advantages that mirror-based fusion systems may exhibit for the generation of economic fusion power.

1987-08-10

348

Magnetic fields of x-ray pulsars  

Energy Technology Data Exchange (ETDEWEB)

An analytic model of magnetic torques applied to an accreting neutron star is employed to evaluate the magnetic dipole moments of x-ray pulsars. A new type of close binary system containing a neutron star is suggested.

1982-09-01

349

Magnetic excitations studied with time-of-flight spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

An introduction to time-of-flight neutron spectroscopy is presented in the context of the study of magnetic materials. Examples are taken from the class of rare earth and actinide magnetic materials known as `strongly correlated electron` systems. (author) 11 figs., 24 refs.

1996-11-01

350

Eddy Current Inspection of Mildly Ferromagnetic Tubing.  

Science.gov (United States)

The past decade has seen the development of eddy current probes for inspection of the mildly ferro-magnetic alloy Monel 400. Due to the rapid advances in permanent magnet technology similar probes have been upgraded to magnetically saturate, and hence ins...

1984-01-01

351

Active magnetic regenerator  

Energy Technology Data Exchange (ETDEWEB)

The disclosure is directed to an active magnetic regenerator apparatus and method. Brayton, Stirling, Ericsson, and Carnot cycles and the like may be utilized in an active magnetic regenerator to provide efficient refrigeration over relatively large temperature ranges.

1982-01-01

352

Nanocrystalline permanent magnets with enhanced properties  

International Nuclear Information System (INIS)

Parameters of permanent magnets result from the combination of intrinsic properties such as saturation magnetization, magnetic exchange, and magnetocrystalline energy, as well as microstructural parameters such as phase structure, grain size, and orientation. Reduction of grain size into nanocrystalline regime (#approx# 50 nm) leads to the enhanced remanence which derives from ferromagnetic exchange coupling between highly refined grains. In this study the fundamental phenomena, quantities, and structure parameters, which define nanophase permanent magnets are presented and discussed. The theoretical considerations are confronted with experimental data for nanocrystalline Sm-Fe-N type permanent magnets. (author)

2001-09-23

353

Malignant transformation of diploid human fibroblasts by transfection of oncogenes  

Energy Technology Data Exchange (ETDEWEB)

This document consist of brief reports prepared by postdoctoral students supported by the project, each describing his accomplishments under the grant. Topics include (1) Malignant Transformation of MSU-1. 1 Cells by Gamma Radiation, (2) Correlation between Levels of ras Expression and Presence of Transformed Phenotypes Including Tumorigenicity, Using a Modulatable Promoter, (3) Relation between Specific rad Oncogene Expression, (4) Correlation of Genetic Changes in Fibroblastic Tumors with Malignancies, (5)Transformation of MSU-1.1 Cells by sis Oncogene, (6) Malignant Transformation of MSU-1.0 Cells, (7) Correlation of Urokinase Plasminogen Activation (mu-PA) with Malignant Phenotype, (8)Two Dimensional Gel Electrophoresis Studies of the Proteins of the Major Cell Strains of the MSU-1 Family of Cells, and (9) Correlation between Proteinase Activity Levels and Malignancy.

1992-01-01

354

Investigation into #beta##reversible##omega#-transformation in pseudo -#beta# -titanium VT30 alloy, doped with hydrogen  

International Nuclear Information System (INIS)

To study #beta# #reversible# #omega#-transformation in pseudo-#beta#-titanium alloy VT30, doped by hydrogen, methods of X-ray diffraction and thermodifferential analyses are used. It is established that in the process of heating of the hardened alloy from 0.004-0.1% H first formation and then dissolution of #omega# phase take place. An increase in hydrogen content to 0.1% decreases thermal effect of the processes and does not affect the temperature of #beta# #reversible# #omega#-transformation. Introduction of hydrogen in the concentration of 0.2% and higher suppresses completely #beta# #reversible# #omega# - transformation. A decrease in heating rate displaces #beta# #reversible# #omega#-transformation to lower temperatures.

355

Gear Fault Diagnosis Based on Continuous Wavelet Transform  

Science.gov (United States)

A new approach of gear fault diagnosis based on continuous wavelet transform is presented. Continuous wavelet transform can provide a finer scale resolution than orthogonal wavelet transform. It is more suitable for extracting mechanical fault information. In this paper, the concept of time-averaged wavelet spectrum (TAWS) based on Morlet continuous wavelet transform is proposed. Two fault diagnosis methods named spectrum comparison method (SCM) and feature energy method (FEM) based on TAWS are established. The results of the application to gearbox gear fault diagnosis show that TAWS can effectively extract gear fault information. The feature energy of the TAWS features the gear fault advancement very well and is conically proportional to the gear fault advancement.

2002-03-01

356

Untitled - NASA Technical Report Server (NTRS)  

Science.gov (United States)

Principle advantages of magnetic forming for part manufacture appear to lie ... to be an area of great potential for the magnetic forming process. We have a ...

357

Symptoms of the musculoskeletal system and exposure to magnetic fields in an aluminium plant.  

UK PubMed Central (United Kingdom)

OBJECTIVE--The study was performed to examine the influence of the exposure to magnetic fields in the potrooms of an electrolysis plant on the occurrence of musculoskeletal symptoms among the employees....Full Text Available

1995-08-01

358

Refrigerator operating experience on whole body MRI magnet systems  

International Nuclear Information System (INIS)

Several refrigerators for liquid helium and liquid nitrogen systems have been integrated successfully into IGC manufactured whole body Magnetic Resonance Imaging (MRI) magnet systems. The refrigerators have been tested in systems with magnetic fields of 0.6T to 1.5T. Tests were performed to study the effectiveness of the refrigerators, the magnetic field effects on the refrigerators, the effect of the refrigerators on the field uniformity and magnetic resonance image quality. The interface between the refrigerator and the whole body MRI magnet system cryostat was specifically designed to allow retrofit to the existing IGC magnet systems, while ensuring good heat transfer characteristics and good vibration isolation from the cryostat. The interface between the refrigerator and the cryostat and the refrigerator test results are presented.

1985-08-01

359

Progress on the Design and Fabrication of the MICE Focusing Magnets  

Energy Technology Data Exchange (ETDEWEB)

The Muon Ionization Cooling Experiment (MICE) focusing solenoid magnets focus the muon beam within the MICE cooling channel on a liquid or solid absorber that is within the warm bore of solenoid. The focusing magnet has a warm bore of 470 mm. his magnet consists of two coils 210-mm long that is separated by an aluminum mandrel that is 200 mm long. Each of the coils has its own leads. The coils may be operated in either the non-flip mode (solenoid mode with both coils at the same polarity) or the lip mode (quadrupole focusing mode where both coils are at opposite polarity). This report describes the focusing solenoid magnet design that will be built by the vendor. The progress on the construction of the first of the focusing magnets will also be discussed in this report. Ultimately three of these magnets will be built. These magnets will be ...

2009-10-19

360

Possible observation of the coexistence of superconductivity and long-range magnetic order in NdRh_4B_4  

International Nuclear Information System (INIS)

The ternary rare earth compound NdRh_4B_4 has been studied by means of critical field, low temperature heat capacity, and static magnetic susceptibility measurements. Features in the upper critical field and heat capacity data at 1.31 K and 0.89 K suggest the occurrence of long-range magnetic order in the superconducting state. The temperature dependence of the static magnetic susceptibility follows a Curie-Weiss law with an effective magnetic moment #mu#sub(eff) = 3.58 +- 0.05 #mu#sub(B) and a Curie-Weiss temperature thetasub(p) = -6.2 +- 1.0 K between 20 K and room temperature. However, magnetization vs. applied magnetic field isotherms suggest the development of a ferromagnetic component in the Nd"3"+ magnetization at low temperatures. (author).

1979-01-01

361

PLASMA JET WELDING, COATING, AND CUTTING: AN ...  

Science.gov (United States)

... 31. New electric forming methods offer potentials for light metals; magnetic forming and plasma forming. ... 3, 25 Magnetic Forming ..... ...

1963-02-01

362

Ordered magnetic nanohole and antidot arrays prepared through replication from anodic alumina templates  

Energy Technology Data Exchange (ETDEWEB)

Highly ordered arrays of Ni nanoholes and Fe{sub 20}Ni{sub 80} antidots have been prepared, respectively, by replica/antireplica processing and sputtering techniques using nanoporous alumina membranes as templates. Geometrical characteristics as nanohole/antidot diameter, interpore distance and the overall hexagonal symmetry of arrays are controlled through the original templates. Experimental data on their hysteresis and magnetic domain structure have been taken by vibrating sample magnetometry and magnetic force microscopy, respectively. An analysis of the magnetization process, resulting magnetic anisotropy and magnetic domain structure is summarized considering the influence of those geometry aspects. In particular, the hexagonal symmetry and the density of nanohole/antidots determine the overall magnetic behavior, which is of interest in future high-density ...

2008-07-15

363

Ordered magnetic nanohole and antidot arrays prepared through replication from anodic alumina templates  

International Nuclear Information System (INIS)

Highly ordered arrays of Ni nanoholes and Fe20Ni80 antidots have been prepared, respectively, by replica/antireplica processing and sputtering techniques using nanoporous alumina membranes as templates. Geometrical characteristics as nanohole/antidot diameter, interpore distance and the overall hexagonal symmetry of arrays are controlled through the original templates. Experimental data on their hysteresis and magnetic domain structure have been taken by vibrating sample magnetometry and magnetic force microscopy, respectively. An analysis of the magnetization process, resulting magnetic anisotropy and magnetic domain structure is summarized considering the influence of those geometry aspects. In particular, the hexagonal symmetry and the density of nanohole/antidots determine the overall magnetic behavior, which is of interest in future high-density ...

2008-07-01

364

Mechanism of viscosity effect on magnetic island rotation  

Energy Technology Data Exchange (ETDEWEB)

It is shown that plasma viscosity does not influence the magnetic island rotation directly. Nevertheless, it leads to nonstationarity of the plasma velocity. This nonstationarity is the reason of the viscosity effect on island rotation. (author)

2000-04-01

365

Magnetic Properties of Ni Nanoparticles Embedded in ...  

Science.gov (United States)

... M(TH) in applied magnetic fields up to ± 7 T and for temperatures ranging from 2 to 300 K. The superparamagnetic (SPM) behavior of these metallic ...

2011-05-14

366

Localization of small magnets against a noisy background  

Science.gov (United States)

Effective localization of small magnets against a noisy, real world background can involve various methods to first identify the magnetic fields produced by the magnet of interest, then to filter out background noise, and then to analyze the available magnetic field data to localize the magnet. Here we discuss low cost techniques which allow localization of small magnets with field strengths in the milliGauss range against real world background fields in the range of hundreds of mG, which may be fluctuating by up to tens of mG. Such techniques allow magnet tracking to be used to localize catheters in place of more invasive and expensive methods, e.g. fluoroscopy, for a variety of applications, including drug infusion with peripherally inserted central catheters (PICCs), laser ablation (TMR, PTMR) and introduction of pacemaker leads.

2001-05-01

367

Hypoxia and Magnetic Therapy for Personnel Radiation Protection  

International Science & Technology Center (ISTC)

Development of Portable Normobaric Hypoxia and Pulsed Magnetic Field Firmware System for Enhancement of Radio- and Non-specific Resistance in Workers of Environmentally Hazardous Industries

368

Geometry effects in the pulsed magnetization of high-temperature superconductor bulk parts  

International Nuclear Information System (INIS)

The dynamic response of cylindrical and ring-shaped YBaCuO bulk parts to pulsed magnetic fields is calculated by using small sets of finite elements. Some comparisons with experimental results are provided, and they give confidence in the modelling of the superconducting properties. Transient magnetizations as a function of time and space as well as shapes and absolute values of trapped magnetic flux profiles are presented. The influence of the sample geometry is investigated for different millisecond pulsed magnetization processes. Results are reported for different radial thicknesses and heights, different pulse durations, peak magnetic fields and pulse sequences with and without stepwise cooling. Comparisons concerning the achievable trapped magnetic field and flux are made, and implications for the use of high-temperature superconductor bulk parts as ...

2005-02-01

369
370

Formulation development and evaluation of metronidazole magnetic nanosuspension as a magnetic-targeted and polymeric-controlled drug delivery system  

Energy Technology Data Exchange (ETDEWEB)

A nanosuspension of magnetically tagged metronidazole was developed by the solvent displacement method coupled with ultrasonication and was evaluated for its physicochemical properties. The drug release from metronidazole magnetic nanosuspension at pH 1.2 and 7.0 shows maximum correlation coefficient for zero order and Higuchi model, respectively. The anthelmintic activity of the formulated metronidazole magnetic nanosuspension was evaluated on Indian earthworms (Pheretima poi). Metronidazole magnetic nanosuspension at a dose of 10 and 50 mg/ml shortened by 31% and 34%, respectively, the mean time to death of the earthworms when compared against a non-magnetic metronidazole suspension. Thus, the developed metronidazole magnetic nanosuspension showed potent, controlled and targeted drug action and might be a good therapeutic avenue in combating infectious GI ...

2009-05-15

371

Evaluation of Commercial Magnetic Descalers.  

Science.gov (United States)

With the increased costs of maintaining boilers and chillers entrepreneurs around the country have offered magnetic and similar devices to facilities as viable alternatives to their maintenance program. This report gives a brief history of some of the pre...

1984-01-01

372

Develop Magnetic Coil Design and Manufacturing Capability.  

Science.gov (United States)

... design, and manufacturing knowledge have been acquired and used to develop an 'in-house' capability for the fabrication of magnetic forming coils ...

1974-11-01

374

CONTRACT: NAS 8-11811 DESIGN, DEVELOPMENT, MANUFACTURE, AND ...  

Science.gov (United States)

has been generally related to magnetic forming. One of the methods suggested was the following: A "pancake" magnetic coil is placed over a thin aluminum ...

375

Application of the grazing angle polarized neutron reflectometry to study the magnetism in thin films and stratified media  

Energy Technology Data Exchange (ETDEWEB)

From optical point of view and due to the magnetic interaction of the cold neutrons with the unpaired electron shell, magnetic materials hae a neutron spin-dependent refractive index n[sup +] [spin up] and n[sup -] [spin down]. Magnetic media such as Fe, Co and Ni react like birefringent uniaxial crystals in ordinary optica. n[sup +] and n[sup -] are the equivalent of the ordinary and extraordinary refractive indices. The specular reflection of spin polarized neutrons which is due to the discontinuity of the magnetic induction at the surface of the ferromagnet is a sensitive probe of surface and interface magnetism. We shall first give the background of the art of polarized neutron optics. Secondly, some recent examples from surface and interface magnetism will be given to illustrate the power of this technique such as the magnetic coupling ...

1992-12-01

376

Anisotropic forming of magnetic powders mixed with ultraviolet resin; Shigaisen koka jushi wo mochiita jisei funmatsu no haiko seikei  

Energy Technology Data Exchange (ETDEWEB)

For the purpose of solving the limitations such as shape and dimension for magnetic compact fabricated by conventional anisotropic forming under magnetic orienting field, the feasibility of a new magnetic forming process was studied. Ferrite powder mixed with UV resin was compacted in the die mold and followed by alignment under the magnetic field. Effects of viscosity of UV resin and forming condition on magnetic characteristics of the compact was investigated. Maximum degree of alignment for the ferrite powder reached to 0.826. It was predicted that the proposed method had make it possible to fabricate a high performance magnet having the anisotropic alignment of the magnetic powder. The UV resin is desirable to have low viscosity, good properties such as formability and configuration stability for the compact and also parting- ability ...

1999-01-15

377

An Advance in Superconducting Magnet Technology Opens the Door...  

Science.gov (United States)

magnet research at several national laboratories through its Advanced Accelerator Technology Program. The HEP Conductor Development Program, a collaboration among national...

2011-08-20

378

Acoustic cloaking and transformation acoustics  

International Nuclear Information System (INIS)

In this review, we give a brief introduction to the application of the new technique of transformation acoustics, which draws on a correspondence between coordinate transformation and material properties. The technique is formulated for both acoustic waves and linear liquid surface waves. Some interesting conceptual devices can be designed for manipulating acoustic waves. For example, we can design acoustic cloaks that make an object invisible to acoustic waves, and the cloak can either encompass or lie outside the object to be concealed. Transformation acoustics, as an analog of transformation optics, can go beyond invisibility cloaking. As an illustration for manipulating linear liquid surface waves, we show that a liquid wave rotator can be designed and fabricated to rotate the wave front. The acoustic transformation media require acoustic materials which are anisotropic and ...

2010-03-24

379

Magnetic properties of a SmNiSn single crystal  

Energy Technology Data Exchange (ETDEWEB)

The magnetic properties of a single crystal of SmNiSn with the orthorhombic {epsilon}-TiNiSi-type crystal structure have been investigated by magnetic susceptibility, magnetization and electrical resistivity measurements from 1.5 K to room temperature. Two anomalies have been found in the magnetic susceptibility, indicating an antiferromagnetic phase transition at T{sub N}=9.4 K and a second transition at 4.4 K. A large magnetic anisotropy has been found at low temperatures in the temperature and field dependencies of magnetic susceptibility and magnetization. Below 80 K, the easy axis of the magnetization is the c-axis. At T=2.0 K, the c-axis magnetization curve exhibits metamagnetic-like behavior at H{sub c}=42 kOe and reaches 0.54 emu/g at H=55 kOe, whereas for the a- and b-axis the ...

2003-04-01

380

Development of magnetic drive packless valves for commercial purpose  

Energy Technology Data Exchange (ETDEWEB)

A study on development of magnetic drive packless valves for commercial purpose showed the results as follows; 1. Study on the radial rays effecting to the permanent magnets -Measurement of the strength of Nd-magnets according to irradiation of radial rays. 2. Effects of temperature on the magnetic driving device -Temperature dependency of the Nd-casting magnets. -Effects of temperature on the heat releasing fins of high-temperature valve. 3. Optimization of torque -Arranging method of permanent magnets -Measuring method and results of torque. 4. Design, manufacture and test for the pressure-resisting structure of magnetic power transmitting device -Calculation and design for the flat circular plates under pressure of the magnetic power transmitting device -Design, manufacture and test for the pressure-resisting ...

1995-09-01

381

Challenges in fabrication of 180deg magnet chamber  

International Nuclear Information System (INIS)

180 deg magnet chamber is used in Folded Tandem Ion Accelerator for passage and 180 deg bending of ion beam. The chamber is placed between 180 deg terminal magnet (Electro-magnet), which is used for bending, and analysing the beams. Magnet with a particular magnetic field strength bends ions of only specified mass energy product through a precise path. There is also a space limitation in the direction of magnetic field. Both of them require the magnet chamber to be of a close tolerance. Accuracy of center distance between inlet and outlet port of the magnet chamber has to be at par with the concentricity of high energy and low energy beam line. To achieve this we started the fabrication of magnet chamber by following two methods: a) Circular rolling and bending of rectangular tube for 180 deg sector ...

2006-11-01

382

AC loss measurements of model and full size 50mm SSC collider dipole magnets at Fermilab  

Energy Technology Data Exchange (ETDEWEB)

Tests have recently been performed at Fermilab in order to measure the energy losses due to eddy currents and iron and superconductor magnetization. These measurements were performed on six 1.5m long model magnets and eight 15m long full scale collider dipole magnets. AC losses were measured as a function of ramp rate using sawtooth ramps from 500, to 5000 Amps for both types of magnets, while bipolar studies were additionally performed on some of the short magnets. The measured magnet voltage and current for a complete cycle are digitally integrated to yield the energy loss per cycle. Measurement reproducibility is typically 5%, with good agreement between long magnet measurements and extrapolations from short magnet measurement results. Magnetization loss measurements among similar ...

1992-09-01

385

The Effect of Static Magnetic Forces on Water Contents and Photosynthetic Pigments in Sweet Basil Ocimum basilicum L. (Lamiaceae)  

International Nuclear Information System (INIS)

Three different magnetic regimes; aerial, surface and buried; each with three different forces, have been used to investigate their effects on the water contents and photosynthetic pigments of sweet basil plants (Ocimum basilicum L.). Two groups of sweet basil seeds, Ocimum basilicum L. have been cultivated, one under normal conditions and the second has been subdivided into three portion (aerial, surface and buried) to examine the effect of different magnetic forces coming from the three directions on the resulted plants. At all directions of magnets, water contents have been significantly affected by the magnetic forces. Chlorophyll A and carotene contents have been affected, as well, according to the three magnetic forces coming from soil surface regime only. Chlorophyll B did not significantly affected by differences magnetic forces in the three regimes, but ...

386

THE APPLICATION OF STEEP PULSE CURRENTS TO THE ...  

Science.gov (United States)

... Title : THE APPLICATION OF STEEP PULSE CURRENTS TO THE ELECTROHYDRAULIC AND MAGNETIC FORMING OF METALS. ...

1966-04-01

393

Recovery Effects of a 180?mT Static Magnetic Field on Bone Mineral Density of Osteoporotic Lumbar Vertebrae in Ovariectomized Rats  

UK PubMed Central (United Kingdom)

The effects of a moderate-intensity static magnetic field (SMF) on osteoporosis of the lumbar vertebrae were studied in ovariectomized rats. A small disc magnet (maximum magnetic flux density 180 mT)...Full Text Available

2011-01-01

394

QCCM - Center for NMR Quantum Information Processing  

Science.gov (United States)

... decoherence. Descriptors : *QUANTUM COMPUTING, NUCLEAR MAGNETIC RESONANCE, JOSEPHSON JUNCTIONS. Subject ...

2011-02-16

395

Perpendicular magnetic anisotropy of ultrathin FeCo alloy films on Pd(0 0 1) surface: First principles study  

International Nuclear Information System (INIS)

Using the full potential linearized augmented plane wave (FLAPW) method, thickness dependent magnetic anisotropy of ultrathin FeCo alloy films in the range of 1 monolayer (ML) to 5 ML coverage on Pd(0 0 1) surface has been explored. We have found that the FeCo alloy films have close to half metallic state and well-known surface enhancement in thin film magnetism is observed in Fe atom, whereas the Co has rather stable magnetic moment. However, the largest magnetic moment in Fe and Co is found at 1 ML thickness. Interestingly, it has been observed that the interface magnetic moments of Fe and Co are almost the same as those of surface elements. The similar trend exists in orbital magnetic moment. This indicates that the strong hybridization between interface FeCo alloy and Pd gives rise to the large magnetic moment. Theoretically calculated ...

2009-06-01

397

Optimization of soft magnetic properties in Fe-B and Fe-B-Si amorphous alloys obtained by melt spinning method  

International Nuclear Information System (INIS)

In the present paper the progress of optimization of soft magnetic properties have been studied by applying different experimental techniques (magnetic measurements, electric measurements, X-ray analysis, and high-resolution electron microscopy observation). It has been shown that an increase in magnetic permeability after optimization annealing can be mainly attributed to annealing out of microvoids. (author)

2001-09-23

398

NASA Technical Reports Server - Magnetic forming coil design and ...  

Science.gov (United States)

Site Error There's a problem with your browser or settings. ...

403

Magnetic forming studies  

Science.gov (United States)

Elastodynamic approach to measuring stress-strain relationship of uniaxially stressed wire, and

1967-01-01

405

Magnetic excitations in amorphous ferromagnets  

Science.gov (United States)

Neutron scattering techniques have been used to measure the static structure and magnetic excitations in amorphous magnets. Sum rules and computer models are used to discuss the relationship between the static disorder and the shape of the excitation spectrum. Polarized beam measurements of chi''(Q,E) are compared to analytical theories and computer calculations for the magnetic excitations in amorphous ferromagnets.

1978-03-01

406

Magnetic electronic lenses, quadrupole and octupole for microsystem electron beam techniques  

International Nuclear Information System (INIS)

The MOS-technology allows to make tiny electronic lenses for multibeam electron systems. In the paper results of research and principles of designing of tiny magnetic electron lenses are submitted. Electronic lenses with a nonconventional configuration of tiny magnetic circuit and electronic lenses with coincident electric and magnetic fields in nonconventional tiny performance are considered

2006-09-01

410

Influence of rotation and magnetic field on the minimum mass of a main-sequence star  

Energy Technology Data Exchange (ETDEWEB)

The influence of rigid-body and differential rotation and of a fine-scale chaotic magnetic field and a poloidal magnetic field on the minimum mass of a main-sequence star is investigated. It is shown that rotation and a magnetic field with an energy equal to 10--20% of the star's gravitational energy increase the minimum mass of a main-sequence star by 1.5--2 times.

1980-11-01

427

A STUDY TO DETERMINE THE DEFORMATION ...  

Science.gov (United States)

... crystals and polycrystals. Nevertheless, explosive forming, magnetic forming, etc., are all high-strain-rate processes that ...

1963-04-01

428

A HELICAL MAGNET DESIGN FOR RHIC.  

Energy Technology Data Exchange (ETDEWEB)

Helical dipole magnets are required in a project for the Relativistic Heavy Ion Collider (RHIC) to control and preserve the beam polarization in order to allow the collision of polarized proton beams. Specifications are for low current superconducting magnets with a 100 mm coil aperture and a 4 Tesla field in which the field rotates 360 degrees over a distance of 2.4 meters. A magnet meeting the requirements has been developed that uses a small diameter cable wound into helical grooves machined into a thick-walled aluminum cylinder.

1997-05-12

429

Magnetocaloric and magnetoresistance studies of GdPd{sub 2}Si  

Energy Technology Data Exchange (ETDEWEB)

The compound GdPd{sub 2}Si, which is reported to order antiferromagnetically at 13 K, has been investigated by heat capacity and electrical resistivity measurement in the presence of external magnetic fields. In contrast to an earlier report, the zero-field heat capacity and resistivity data indicate two magnetic transitions at 13 and 17 K. The external magnetic field substantially influences the resistivity and heat capacity of the compound around the magnetic ordering temperature. The magnetocaloric effect, which is calculated from in-field heat capacity data, is quite large around the magnetic transition temperature. The magnetoresistance is also large near the magnetic ordering temperature. The metamagnetic transition is observed for 10 kOe magnetic field both in magnetocaloric and in magnetoresistance data. The metamagnetic transition ...

2001-01-22

430

Magnetocaloric and magnetoresistance studies of GdPd_2Si  

International Nuclear Information System (INIS)

The compound GdPd_2Si, which is reported to order antiferromagnetically at 13 K, has been investigated by heat capacity and electrical resistivity measurement in the presence of external magnetic fields. In contrast to an earlier report, the zero-field heat capacity and resistivity data indicate two magnetic transitions at 13 and 17 K. The external magnetic field substantially influences the resistivity and heat capacity of the compound around the magnetic ordering temperature. The magnetocaloric effect, which is calculated from in-field heat capacity data, is quite large around the magnetic transition temperature. The magnetoresistance is also large near the magnetic ordering temperature. The metamagnetic transition is observed for 10 kOe magnetic field both in magnetocaloric and in magnetoresistance data. The metamagnetic transition ...

2001-01-22

431

Magnetic separation anxiety  

International Nuclear Information System (INIS)

This paper reports that only a few years ago superconducting magnetic separation was viewed as the next major market for superconducting magnets. The first commercial units had been installed, worked flawlessly, and demonstrated real economic viability. The potential market was seen as quite large, and many people believed that superconducting magnetic separation would soon show the same rapid growth that MRI had demonstrated after its initial success. These hopes even prompted IGC, one of the top MRI magnet builders, to form a separate division devoted to magnetic separation. Despite the existence of Magstream, IGC has not been overly active in the market. As a technology that has applications from the clay on the Earth to the soil on the moon, superconducting magnetic separation has yet to become widely used.

1992-01-01

432

Effect of the induced magnetic field on peristaltic flow of a couple stress fluid  

Science.gov (United States)

We have analyzed the MHD flow of a conducting couple stress fluid in a slit channel with rhythmically contracting walls. In this analysis we are taking into account the induced magnetic field. Analytical expressions for the stream function, the magnetic force function, the axial pressure gradient, the axial induced magnetic field and the distribution of the current density across the channel are obtained using long wavelength approximation. The results for the pressure rise, the frictional force per wave length, the axial induced magnetic field and distribution of the current density across the channel have been computed numerically and the results were studied for various values of the physical parameters of interest, such as the couple stress parameter ?, the Hartmann number M, the magnetic Reynolds number R and the time averaged mean flow rate ?. Contour plots for the stream and ...

2008-06-01

433

Eddy current probe development based on a magnetic sensor array; Developpement d'un imageur magnetique pour le controle non destructif par courants de Foucault  

Energy Technology Data Exchange (ETDEWEB)

This research deals with in the study of the use of innovating magnetic sensors in eddy current non destructive inspection. The author reports an analysis survey of magnetic sensor performances. This survey enables the selection of magnetic sensor technologies used in non destructive inspection. He presents the state-of-the-art of eddy current probes exploiting the qualities of innovating magnetic sensors, and describes the methods enabling the use of these magnetic sensors in non destructive testing. Two main applications of innovating magnetic sensors are identified: the detection of very small defects by means of magneto-resistive sensors, and the detection of deep defects by means of giant magneto-impedances. Based on the use of modelling, optimization, signal processing tools, probes are manufactured for these both applications.

2007-06-15

434

On the temperature dependence of the magnetic excitations  

International Nuclear Information System (INIS)

We compare experimental data for temperature dependence of the magnetic order parameter and the magnetic excitations (spin waves) in materials with a quenched orbital moment and a well-defined spin quantum number. It is observed that the thermal decrease of the two quantities proceeds according to the same analytical function of the type y(T)=1-cT"#epsilon# with an identical exponent #epsilon#. This power function applies not only asymptotically for T->0 but holds over a wide temperature range. The exponent #epsilon# is universal, i.e. independent of spin order type and lattice symmetry and depends only on the dimensionality of the relevant interactions and on whether the spin quantum number is integer or half-integer. The different T"#epsilon# functions are identified as representations of stable universality classes. The fact that order parameter and magnetic excitations follow the same T"#epsilon# function shows that ...

2005-07-15

435

Theory of zwitterionic molecular-based organic magnets  

British Library Electronic Table of Contents (United Kingdom)

We describe a class of organic molecular magnets based on zwitterionic molecules (betaine derivatives) possessing donor, p bridge, and acceptor groups. Using extensive electronic structure calculations we show the electronic ground-state in these systems is magnetic. In addition, we show that the large energy differences computed for the various magnetic states indicate a high Neel temperature. The quantum mechanical nature of the magnetic properties originates from the conjugated p bridge (only p electrons) in cooperation with the molecular donor-acceptor character. The exchange interactions between electron spin are strong, local, and independent on the length of the p bridge.

2011-01-01

436

Occurrence of magnetism in superconductors  

Science.gov (United States)

We discuss how magnetic phenomena affect superconductivity in simple metals, transition metals and alloys thereof, and dilute Rare-Earth alloys. It is shown both qualitatively and quantitatively that superconductors are sensitive probes for studying itinerant spin excitations, local spin excitations associated with nearly magnetic impurities, the effect of the atomic environment on the stability of local magnetic moments, and the nature of the spin order in Rare-Earth alloys. Also, we discuss how magnetic impurities can be used to study the electronic configuration which is responsible for superconductivity in Laves-phase crystals like A-15 compounds and ..beta..-W crystals, for example.

1970-12-14

437

Magnetic response of ultrathin Fe on MgO: A polarized neutron reflectometry study  

Energy Technology Data Exchange (ETDEWEB)

The magnetization of ultrathin bcc Fe films (two and three monolayers) on MgO was measured and compared with the behavior predicted for a two-dimensional ferromagnet. The experiment indicated that no hysteresis was present in the magnetization. Instead, the magnetization at low temperature was affected by a marked field cooling effect. These observations lead to the conclusion that films of Fe on MgO of such thickness exhibit superparamagnetic behavior as if they were not entirely continuous. In contrast, films thicker than five monolayers exhibit a magnetic response close to that of bulk iron.

1994-11-15

438

Magnetic properties of glasses from geothite industrial wastes recycling (FeOOH)  

International Nuclear Information System (INIS)

It has been carried out the magnetic properties determination for high iron oxide content glasses series obtained from a geothite red mud waste from the zinc hydrometallurgy and dolomite and glass cullet as main raw materials. It has been determined the magnetic susceptibility and magnetization values for the glasses here investigated. The results suggest that the magnetic behaviour are depending on the glass chemical composition, so that glasses can be differently classified like ferrimagnetic, ferromagnetic, superparamagnetic and paramagnetic. (Author) 6 refs.

439

Magnetic fluctuations in paramagnetic Mn{sub 0.81}Ni{sub 0.19}  

Energy Technology Data Exchange (ETDEWEB)

Magnetic fluctuations present in the paramagnetic Mn{sub 0.81}Ni{sub 0.19} system have been investigated by measuring inelastic magnetic neutron scattering from a single crystal at temperatures of 450, 585 and 700 K. Antiferromagnetic correlations are observed to be present at all the temperatures studied. The spectral width of the magnetic scattering has been observed to increase with temperature, while the spatial range of the magnetic correlations is seen to decrease as the temperature is raised. The wave-vector-dependent susceptibility is found to follow a Curie-Weiss law near the (1 0 0) position, in agreement with theoretical predictions.

2006-11-15

440

Hydromagnetic rotational braking of magnetic stars  

International Nuclear Information System (INIS)

It is suggested that the magnetic Ap stars can be rotationally decelerated to long periods by the braking action of the associated magnetic field on time scales of order 10"7--10"1"0 years depending on whether the star's dipole field is aligned perpendicular or parallel to the rotation axis. Rotation includes a toroidal magnetic field in the plasma surrounding a star, and the accompanying magnetic stresses produce a net torque acting to despin the star. These results indicate that it is not necessary to postulate mass loss or mass accretion for this purely hydromagnetic braking effect.

441

Correlation between Magnetic Field Quality and mechanical components of the Large Hadron Collider Main Dipoles  

CERN Document Server

The homogeneity of the magnetic field in the LHC dipoles strongly depends on the correct position of the superconducting cables: this is related to the quality of the dipole components, such as the dimension of the coil spacers (copper wedges), of the cable and of the collars. The performance in operational conditions is also affected by the magnetization of the cables. In this work, we analyse the measurements of these quantities during the production of the 1276 LHC dipoles, their trends, and the relation to the measured magnetic field. A novel mtehod to locate electrical shorts based on the analysis of magnetic measurements is also presented, and applications to 15 dipoles reascued during the production is given.

2006-01-01

442

The influence of martensitic transformation on mechanical properties of cast high alloyed CrMnNi-steel under various strain rates and temperatures  

International Nuclear Information System (INIS)

Metastable austenitic steels show excellent mechanical properties, such as high strength combined with excellent ductility and toughness due to martensitic transformation under mechanical loading (transformation induced plasticity effect). A good energy consumption, and, in the case of high-alloyed metastable austenitic steels, a high corrosion resistance, increase the potential of these materials for diverse applications, also in regard of safety requirements. Up to now, numerous wrought alloys were investigated concerning mechanical behaviour, TRIP-effect, martensitic transformation behaviour and modelling of transformation kinetics or stress-strain behaviour. New high alloyed cast CrMnNi-steels, developed at Technical University Bergakademie Freiberg, provide the chance to reduce processing steps, production time and costs. In order to understand the influence of temperature on the martensitic phase ...

2010-07-01

443

Online monitoring of power transformers - a new low-cost system for small and medium power transformers; Monitoring von Leistungstransformatoren - Jetzt auch fuer kleine und mittlere Baugroessen  

Energy Technology Data Exchange (ETDEWEB)

Until now, monitoring of power transformers focussed mainly large generator and network transformers. Siemens goes a step ahead and provides a system especially developed and designed for small and medium power transformers, e.g. for the 100 kV level. This low cost version could be achieved by restriction to really necessary measuring quantities. This allows to realize also for small and medium power transformers an online monitoring including an estimation of aging and as an option an early warning to avoid unexpected failures. (orig.) [German] Die Ueberwachung (Monitoring) von Leistungstransformatoren war bisher vor allem fuer Maschinentransformatoren und grosse Netzkuppeltransformatoren in der Diskussion. Siemens geht einen Schritt weiter und stellt nun auch ein System bereit, das speziell fuer kleine und mittlere Leistungstransformatoren, z.B. der 110-kV-Spannungsebene, konzipiert ist. Diese ...

1999-09-20

444

Evaluation of advanced technologies for power transformers. Final report  

Energy Technology Data Exchange (ETDEWEB)

The high insulating strength of certain gases, such as sulfur hexafluoride, when used at high pressure, suggests that there may be advantages to compressed gases as the insulating fluid in power transformers. However, simply exchanging the oil for compressed gas in an otherwise conventional transformer design will not yield a significant overall advantage. Compressed gases present the engineer with properties which are quite different from mineral oil. If gases are to be used as the major insulating fluid in power transformers, then virtually all aspects of the insulation and cooling of the apparatus must be reconsidered, affording an opportunity to introduce new design concepts, new materials, and new construction techniques. In this program, the feasibility of using the following principal design concepts has been explored: sheet conductors for the windings; a system of sealed, self-contained, annular cooling ducts ...

1981-01-01

445

How the Performance of a Superconducting Magnet is affected by theConnection between a small cooler and the Magnet  

Energy Technology Data Exchange (ETDEWEB)

As low temperature cryocoolers become more frequently used to cool superconducting magnets, it becomes increasingly apparent that the connection between the cooler and the magnet has an effect on the design and performance of the magnet. In general, the use of small coolers can be considered in two different temperature ranges; (1) from 3.8 to 4.8 K for magnet fabricated with LTS conductor and (2) from 18 to 35 K for magnets fabricated using HTS conductor. In general, both temperature ranges call for the use of a two-stage cooler. The best method for connecting a cooler to the magnet depends on a number of factors. The factors include: (1) whether the cooler must be used to cool down the magnet from room temperature, (2) whether the magnet must have one or more reservoirs of liquid cryogen to keep the ...

2005-09-08

446

Anisotropic Nd{endash}Fe{endash}B bonded magnets made from HDDR powders (invited)  

Energy Technology Data Exchange (ETDEWEB)

Anisotropic Nd{endash}Fe{endash}B magnet powders can be produced by the hydrogenationdecomposition-desorption-recombination (HDDR) process from Nd{endash}Fe@ xnB{endash}Co{endash}M ({ital M}=Ga, Zr, Nb, Hf, and Ta) alloys. The present status of those HDDR powders and the bonded magnets made from them are reviewed with regards to the powder particle size dependence of their magnetic properties, their magnetic thermal stability, and their magnetization behavior. The results of a mechanistic study on the recombination step are also presented. The magnetic properties of the anisotropic HDDR powder depend relatively little on the powder particle size. Bonded magnets with a density of {approximately}6.20 g/cm{sup 3} and a BH{sub max} of 18.5{endash}20.5 MGOe can be produced from anisotropic HDDR powders with particle sizes of below 300 {mu}m diam. ...

1996-04-01

447

The canonical form of the Rabi hamiltonian  

CERN Document Server

The Rabi Hamiltonian, describing the coupling of a two-level system to a single quantized boson mode, is studied in the Bargmann-Fock representation. The corresponding system of differential equations is transformed into a canonical form in which all regular singularities between zero and infinity have been removed. The canonical or Birkhoff-transformed equations give rise to a two-dimensional eigenvalue problem, involving the energy and a transformational parameter which affects the coupling strength. The known isolated exact solutions of the Rabi Hamiltonian are found to correspond to the uncoupled form of the canonical system.

1996-01-01

448

T-duality, space-time spinors and R-R fields in curved backgrounds  

Energy Technology Data Exchange (ETDEWEB)

We obtain the T-duality transformations of space-time spinors (the supersymmetry transformation parameters, gravitinos and dilatinos) of type-II theories in curved backgrounds with an isometry. The transformation of the spinor index is shown to be a consequence of the twist that T-duality introduces between the left- and right-moving local Lorentz frames. The result is then used to derive the T-duality action on Ramond-Ramond field strengths and potentials in a simple way. We also discuss the massive IIA theory and, using duality, give a short derivation of 'mass'-dependent terms in the Wess-Zumino actions on the D-brane world-volumes.

2000-02-28

449

Quantum mechanics of spin-1/2 tachyons  

International Nuclear Information System (INIS)

The wave equation for spin;1/2 tachyons is derived from the Dirac equation and the principle of relativity extended to superluminal Lorentz frames. From this wave equation and the Dirac equation infinite velocity spinor transformations are obtained. They yield bispinors of the plane-wave states of the tachyon, their interpretation and covariant orthogonality relations satisfied by them. The transformation properties of the bispinors under Lorentz transformation are discussed. The boundary conditions for the free propagator of wave functions of tachyons are obtained and the propagator is constructed. Then the covariant S-matrix for scattering from an electromagnetic field is derived. It is applied to the scattering of electron-tachyons from the Coulomb field.

450

Online tax payment systems as an emergent aspect of governmental transformation  

British Library Electronic Table of Contents (United Kingdom)

The achievement of governmental transformation through the use of electronically delivered services is a worthy goal that requires significant planning and research to achieve. In order to reach transformational paradigm shifts in governmental operation, it will first be necessary to understand and optimize present governmental e-Service provisions. Of these, the revenue function of taxation is paramount. This paper describes factors related to the use and acceptance by accounting professionals of information technology intended to facilitate electronic tax filing systems. Though tested in the context of governmental tax management systems in Turkey, our findings on the use and acceptance of e-Tax systems are relevant and applicable to a great number of nations and contexts as the ongoing ...

2011-01-01

451

Estimation of seasonal correction factors through Fourier decomposition analysis-a new model for indoor radon levels in Irish homes  

Energy Technology Data Exchange (ETDEWEB)

Radon concentrations in homes have been shown to vary considerably with season. It is important to account for this by applying a correction factor to any home radon measurement of less than one year. To date, Irish radon measurement services have used correction factors based on data derived for the UK in the 1980s. In the absence of similar data for Ireland at the time, these were considered suitable for use due to the similarities between the climates, house types and lifestyles in the two countries. In order to better estimate the long-term radon concentration, measurements from 5640 Irish homes were used to derive a set of correction factors specifically for Ireland. These were generated by means of Fourier decomposition analysis and the new correction factors compared, using 95% confidence intervals, to those derived for the UK using the same analysis and to those currently in use for Ireland. In both cases, a significant difference was found between 10 of ...

2010-09-15

452

Bar strengths in spiral galaxies estimated from 2MASS images  

CERN Document Server

Non-axisymmetric forces are presented for 107 spiral galaxies using the 2 Micron All Sky Survey (2MASS) images. We apply both Cartesian integration and a polar grid integration utilizing a limited number of azimuthal Fourier components of density. We found that bar strength is independent of the method used to evaluate the gravitational potential. However, the polar method is more suitable for weak and noisy images. Bar strength was found to be sensitive to the Hubble-type dependent scale height of the disk, which has been ignored in the previous studies. On the other hand, the method is rather insensitive to the vertical model of the disk, as long as a same vertical dispersion is assumed, or to the boxy/peanut shaped structure, studied in terms of non-constant vertical scale height along the disk. In the near-IR most galaxies in our sample show non-axisymmetric forces in some level, and 40 percent of them have bars in a sense that they have regions with a constant ...

2002-01-01

453

Wave extrapolation in the spatial wavelet domain with application to poststack reverse-time migration  

Energy Technology Data Exchange (ETDEWEB)

A wavelet transformation is performed over each of the spatial coordinates of the scalar wave equation. This transformed equation is solved directly with a finite-difference scheme for both homogeneous and smooth inhomogeneous media. Wavefield extrapolation is performed completely in the spatial wavelet domain without transforming back into the space domain at each time step. The wavelet coefficients are extrapolated, rather than the wavefield itself. The numerical solution of the scalar wave equation in the spatial wavelet domain is closely related to the finite-difference method because of the compact support of the wavelet bases. Poststack reverse-time migration is implemented as an application. The resolution spaces of the wavelet transform provide a natural framework for multigrid analysis. Migrated images are constructed from various resolution spaces.

1998-03-01

454

Transforming Clinic Environments into Information Workspaces for Patients  

UK PubMed Central (United Kingdom)

Although clinic environments are a primary location for exchanging information with clinicians, patients experience these spaces as harsh environments to access, use, exchange, and manage information....Full Text Available

2010-01-01

455

Topological field theories and duality  

Energy Technology Data Exchange (ETDEWEB)

Topologically non trivial effects appearing in the discussion of duality transformations in higher genus manifold are discussed in a simple example, and their relation with the properties of Topological Field Theories is established. (author). 16 refs.

1996-05-01

456

The effect of aqueous composition on diffusion coefficient in bentonite  

International Nuclear Information System (INIS)

The diffusion coefficients (De) in bentonite were measured to understand and quantify the influence of groundwater chemistry such as ionic strength and to quantify the alteration of smectite mineralogical transformations. (author)

2009-12-01

457

Telomeres and telomerase in cancer  

UK PubMed Central (United Kingdom)

Myriad genetic and epigenetic alterations are required to drive normal cells toward malignant transformation. These somatic events commandeer many signaling pathways that cooperate to endow aspiring...Full Text Available

2010-01-01

458

Tachyons in gravitational field  

International Nuclear Information System (INIS)

Behaviour of tachyons in gravitational field has been investigated by using imaginary as well as real superluminal Lorentz transformations. Using real superluminal transformations in four- and six-dimensional space-time, an expression for the gravitational force acting on a tachyon, moving along the tachyon corridor constructed to follow the tachyon geodesic, has been derived. The motion of a tachyon through a black hole has also been discussed and it is shown that the black hole acts like a gravitational tunnel for tachyons and the transition between the regions inside and outside the horizon can be understood as real superluminal transformations transforming a R"4=(r,t) world into a T"4=(t,r) world. 36 refs.. (author).

459

Tachyon Cerenkov radiation  

Energy Technology Data Exchange (ETDEWEB)

By proposing the four-dimensional, reciprocity transformations the appropriate condition for superluminal electromagnetic Cerenkov radiation is obtained by introducing the hypothesis that tachyons possess vector energy and scalar momentum.

1985-09-01

460

Stress-induced martensitic transformation of metastable #beta#-titanium alloy  

International Nuclear Information System (INIS)

The constituent phases and associated deformed microstructure of the quenched Ti-xNb-(0.5-1.5) at.% Si alloy consisting of non-cytotoxicity elements, where x = 24-30 at.%, were investigated to provide pseudoelasticity for biomedical and sensor applications. Optical microscopy revealed that stress-induced martensitic transformation takes place during the deformation in the present alloys. It is confirmed from the X-ray diffraction results of the deformed specimens that the crystal structure of the stress-induced martensite phase is the orthorhombic so-called #alpha#'' structure. Within the alloys having #beta#(bcc) phase studied Nb-poor region appeared to exhibit a dominant behavior for stress-induced martensitic transformation than Nb-rich region. This result suggests that metastable #beta# phase is superior to stable #beta# phase for the occurrence of stress-induced martensitic transformation in the present alloy system.

2007-03-25

461

Order in Spontaneous Behavior  

UK PubMed Central (United Kingdom)

Brains are usually described as input/output systems: they transform sensory input into motor output. However, the motor output of brains (behavior) is notoriously variable, even under identical sensory...Full Text Available

462

National Advisory Committee for Aeronautics 1950 - NASA Technical ...  

Science.gov (United States)

By Charles E. Watkins. 2065. A Transformation Theory of the Partial ..... Mr. Grover Loening. Prof. John R. Markham, Massachusetts Institute of Technology. ...

463

GeoPowering the West  

Energy Technology Data Exchange (ETDEWEB)

Summary brochure of GeoPowering the West (GPW) activities, and areas of technology transfer and market transformation. It also provides current contact information for key DOE and national laboratory staff representing the GPW program.

2007-02-01

464

Fermion-boson symmetry through superluminal transformations  

Energy Technology Data Exchange (ETDEWEB)

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

1985-08-01

465

Dysregulation of the mevalonate pathway promotes transformation  

UK PubMed Central (United Kingdom)

The importance of cancer metabolism has been appreciated for many years, but the intricacies of how metabolic pathways interconnect with oncogenic signaling are not fully understood. With a clear understanding...Full Text Available

2010-08-24

466

Dixon's Theorem and random synchronization  

CERN Document Server

A transformation monoid on a set Omega is called synchronizing if it contains an element of rank 1 (that is, mapping the whole of Omega to a single point). In this paper, I tackle the question: given n and k, what is the probability that the submonoid of the full transformation monoid T_n generated by k random transformations is synchronizing? This question is analogous to Dixon's Theorem that two random permutations generate the symmetric or alternating group with high probability. Following the technique of Dixon's theorem, we need to analyse the maximal non-synchronizing submonoids of T_n. I develop a very close connection between transformation monoids and graphs, from which we obtain a description of non-synchronizing monoids as endomorphism monoids of graphs satisfying some very strong conditions. However, counting such graphs, and dealing with the intersections of their endomorphism monoids, ...

2011-01-01

467

Disordered bcc γ-phase to δ-phase transformation in Zr-rich U-Zr alloy  

British Library Electronic Table of Contents (United Kingdom)

The transformation mechanism of hexagonal delta phase from the disordered bcc gamma phase has not been reported before in the Zr-rich U-Zr alloy system. With the help of X-ray diffraction, transmission electron microscopy (TEM) and high-resolution TEM analyses it was shown that the gamma to delta conversion takes place by the lattice collapse mechanism of omega transformation. It was also ascertained that a higher aging temperature or time promotes the growth of all four variants of the delta phase within a parent gamma grain. In addition, ab initio electronic structure calculations showed that the bcc to hexagonal transformation, involving partial ordering of the parent bcc phase followed by (111) plane collapse, is energetically favorable.

2011-01-01

469

Characteristics of radiation-induced neoplastic transformation in vitro  

Energy Technology Data Exchange (ETDEWEB)

Data are presented to support the hypothesis that the initial step in the morphologic transformation of irradiated rodent (BALB/3T3) cells is a frequent cellular event involving a large fraction of the irradiated population. This process appears to involve DNA damage, but not to represent a targeted mutation in specific structural gene(s). Morphologic transformation and immortalization appear to be distinct steps in the overall process of transformation. In contradistinction to rodent cells, immortalization is a very rare event in human diploid cells which is induced at extremely low frequencies. The hypothesis is presented that immortality develops among clones of cells bearing stable chromosomal rearrangements which emerge during the proliferation of a population of radiation damaged cells.

1986-01-01

470

Capturing energy in the air to power electronics | SmartPlanet  

Wastenet

...smart grid applications where you could place them very close to the high-voltage transmission lines , very close to transformers and so on. Photo:...

471

Army Transformation to Expeditionary Formations  

Science.gov (United States)

... gap" between the arrival ofquick response forces, such as the 82nd Airborne Division and the ... nd Airborne is just exactly that, light airborne infantry. ...

2011-05-14

472

Alpha/Beta Heat Treatment of a Titanium Alloy with a Non ...  

Science.gov (United States)

... transformed at 705°C. The cooling rate and temperature dependence of matrix decomposition for Ti6242 was thus similar to that for Ti64 x [9]. ...

2006-08-01

473

(Hadamard transform imaging)  

Science.gov (United States)

This report describes the design of, and image reconstruction capacity of a Hadamard Raman Microscopic imager. Microscopy of benzoic acid and graphite electrodes, as well as electrophoretic blotting, are described. (CBS)

1990-01-01

474

Selection of transverse modes in laser cavities containing waveguides and open parts  

International Nuclear Information System (INIS)

The transverse modes of a submillimetre laser cavity that contains waveguides and open parts were studied theoretically and experimentally with the purpose of finding methods for mode selection. Two methods based on the filtering of the Fourier spectra of the waveguide modes and the use of their interference were substantiated numerically and realised in experiment. Special attention was paid to the mode selection in tunable lasers. Scaling laws allowing one to use the obtained results in a wide range of the cavity parameters and wavelengths are presented. (laser applications and other topics in quantum electronics)

2001-04-30

475

Lack of oscillations in Dual-Phase-Lagging heat conduction for a porous slab subject to imposed heat flux and temperature  

Energy Technology Data Exchange (ETDEWEB)

This study shows that the physical conditions necessary for thermal waves to materialize in Dual-Phase-Lagging porous media conduction are not attainable in a porous slab subject to a combination of constant heat flux and temperature (Neumann and Dirichlet) boundary conditions. It is demonstrated that the approximate equivalence between Dual-Phase-Lagging (DuPhlag) heat conduction model and the Fourier heat conduction in porous media subject to Lack of Local Thermal Equilibrium (La Lotheq) that suggested the possibility of thermal oscillations and resonance reveals a condition that cannot be fulfilled because of physical constraints. (author)

2005-07-01

476

Application of the neutron television fluoroscopic system to neutron computed tomography  

Energy Technology Data Exchange (ETDEWEB)

Recently the real-time neutron radiography system of the Kyoto University Reactor (KUR) has been developed and practically applied to penetrating the side plates of the MTR type reactor fuels and investigation of moving objects. In this paper an application of the KUR neutron TV system to neutron computed tomography (NCT) is described. By using the NTV system, projection data can be acquired in a single measurement and simultaneously the projection image can be observed on a CRT monitor. The Fourier-convolution technique is used to produce the reconstructed image and its image has a good enough quality for revealing water in a small hole of 1.5 mm in diameter. (orig.).

1984-10-01

477

Application of the neutron television fluoroscopic system to neutron computed tomography  

Energy Technology Data Exchange (ETDEWEB)

Recently the real-time neutron radiography system of the Kyoto University Reactor (KUR) has been developed and practically applied to penetrating the side plates of the MTR type reactor fuels and investigation of moving objects. In this paper an application of the KUR neutron TV system to neutron computed tomography (NCT) is described. By using the NTV system, projection data can be acquired in a single measurement and simultaneously the projection image can be observed on a CRT monitor. The Fourier-convolution technique is used to produce the reconstructed image and its image has a good enough quality for revealing water in a small hole of 1.5 mm in diameter.

1984-10-01

478

An application of the neutron television fluoroscopic system to neutron computed tomography  

International Nuclear Information System (INIS)

Recently the real-time neutron radiography system of the Kyoto University Reactor (KUR) has been developed and practically applied to penetrating the side plates of the MTR type reactor fuels and investigation of moving objects. In this paper an application of the KUR neutron TV system to neutron computed tomography (NCT) is described. By using the NTV system, projection data can be acquired in a single measurement and simultaneously the projection image can be observed on a CRT monitor. The Fourier-convolution technique is used to produce the reconstructed image and its image has a good enough quality for revealing water in a small hole of 1.5 mm in diameter. (orig.).

1984-10-01

479

Alpha-particle scattering from Ca-nuclei  

International Nuclear Information System (INIS)

The possibilities, advantages, and difficulties of determining nuclear matter densities by elastic scattering of alpha-particles are generally discussed. On the basis of particular experimental data - 104 MeV alpha-particle scattering from "4"0,"4"2,"4"4,"4"8Ca - a refined folded potential is introduced using a density-dependent alpha-nucleon-interaction and target nucleus densities described by Fourier-Bessel-series. Thereby, the total nucleon densities of these isotopes were determined with little model dependence. The resulting root-mean-square radii and density differences are compared with other experimental results obtained by different methods. (orig.).

1979-07-01

480

Dynamic-stiffness matrix of embedded and pile foundations by indirect boundary-element method  

Energy Technology Data Exchange (ETDEWEB)

The boundary-integral equation method is well suited for the calculation of the dynamic-stiffness matrix of foundations embedded in a layered visco-elastic halfspace (or a transmitting boundary of arbitrary shape), which represents an unbounded domain. It also allows pile groups to be analyzed, taking pile-soil-pile interaction into account. The discretization of this boundary-element method is restricted to the structure-soil interface. All trial functions satisfy exactly the field equations and the radiation condition at infinity. In the indirect boundary-element method distributed source loads of initially unknown intensities act on a source line located in the excavated part of the soil and are determined such that the prescribed boundary conditions on the structure-soil interface are satisfied in an average sense. In the two-dimensional case the variables are expanded in a Fourier integral in the wave number domain, while in three dimensions, ...

1984-08-01

481

Kondo effect and impurity-impurity interaction in (La, Ce)B_6 alloys  

International Nuclear Information System (INIS)

Measurements of the magnetic susceptibility betweeen 0.03 and 300 K and of the magnetization between 0.05 and 10 K for magnetic fields up to 60kOe have been used to investigate effects from the interaction between the conduction electrons and local magnetic moments in (Lasub(1-x)Cesub(x))B_6 alloys (0.0007<=x<=0.10). For Ce concentrations x<0.006 the data show Kondo-type single impurity behaviour at low temperatures with a transition from a magnetic to a non-magnetic regime of the Ce ions. In the magnetic regime the impurity susceptibility follows a Curie-Weiss law, and in the non-magnetic regime it varies with T"2. An external magnetic field gradually restores the free-ion behaviour of the Ce impurities. For more concentrated alloys interactions between the impurities are observed. The RKKY ...

1978-01-01

482

Development of magnetic separation system of magnetoliposomes  

Energy Technology Data Exchange (ETDEWEB)

The magnetic separation technology using sub-microsized ferromagnetic particle is indispensable in many areas of medical biosciences. For example, ferromagnetic particles (200-500 nm) are widely used for cell sorting in stem cell research with the use of cell surface-specific antigens. Nanosized ferromagnetic particles (10-20 nm) have been suggested as more suitable in drug delivery studies given their efficiency of tissue penetration, however, the magnetic separation method for them has not been established. One of the major reasons is that magnetic force acting on the object particles decreases drastically as a particle diameter becomes small. In this study, magnetic force acting on the targets was enhanced by the combination of superconducting magnet and the filter consisting of ferromagnetic particle. By doing so, we confirmed that Fe{sub 3}O{sub 4} of 20 nm in diameter was ...

2009-10-15

483

Anti-cancer drug loaded iron-gold core-shell nanoparticles (Fe@Au) for magnetic drug targeting.  

Science.gov (United States)

Magnetic drug targeting, using core-shell magnetic carrier particles loaded with anti-cancer drugs, is an emerging and significant method of cancer treatment. Gold shell-iron core nanoparticles (Fe@Au) were synthesized by the reverse micelle method with aqueous reactants, surfactant, co-surfactant and oil phase. XRD, XPS, TEM and magnetic property measurements were utilized to characterize these core-shell nanoparticles. Magnetic measurements showed that the particles were superparamagnetic at room temperature and that the saturation magnetization decreased with increasing gold concentration. The anti-cancer drug doxorubicin (DOX) was loaded onto these Fe@Au nanoparticle carriers and the drug release profiles showed that upto 25% of adsorbed drug was released in 80 h. It was found that the amine (-NH2) group of DOX binds to the gold shell. An in vitro apparatus simulating the human ...

2010-09-01

484

"1"5"1Eu-Moessbauer study of complex magnetism in Eu_2PdSi_3: Effect of Eu"2"+ substitution by Y"3"+ and of high pressure  

International Nuclear Information System (INIS)

With "1"5"1Eu-Moessbauer spectroscopy and other methods the complex magnetic properties of Eu_2PdSi_3, arising from the two crystallographically different lattice sites of the Eu"2"+ ions, have been already studied. Here we study the impact of magnetic dilution of the magnetic Eu"2"+ sites by non-magnetic Y"3"+ ions. A previous specific heat study has found reduced magnetic ordering temperatures with strong indication of disorder effects like in magnetic spin glasses. Here we provide from "1"5"1Eu-Moessbauer spectroscopy detailed information of the impact of Y"3"+ substitution on the magnetic properties of the two lattice sites, well distinguishable in the "1"5"1Eu-spectra. Since the substitution of the larger Eu"2"+ ions by the smaller Y"3"+ ions is connected with a lattice contraction, we also applied high pressure to the Eu_2PdSi_3 sample ...

2010-03-01

485

Resistivity, Hall effect, and magnetic susceptibility of UPd_2Si_2  

International Nuclear Information System (INIS)

The electrical resistivity, Hall effect, and magnetic susceptibility of single-crystal UPd_2Si_2 have been studied between 4.2 and 300 K. A large anisotropy was observed in both the magnetic and transport properties. There is a quadratic temperature dependence of the resistivity for a range of temperatures between 4.2 and 80 K. At higher temperatures, the resistivity indicates a Kondo-type behavior. The behavior of these quantities is accounted for by the magnetic phase transitions at 108 and 136 K reported from neutron-scattering studies. At high temperatures, the magnetic susceptibility of UPd_2Si_2 is Curie-Wiess-like along the c axis. The temperature dependence of the Hall coefficient above 108 K is accounted for by a theoretical model invoking skew scattering of conduction electrons by localized magnetic moments.

486

Resistivity, Hall effect, and magnetic susceptibility of UPd[sub 2]Si[sub 2  

Energy Technology Data Exchange (ETDEWEB)

The electrical resistivity, Hall effect, and magnetic susceptibility of single-crystal UPd[sub 2]Si[sub 2] have been studied between 4.2 and 300 K. A large anisotropy was observed in both the magnetic and transport properties. There is a quadratic temperature dependence of the resistivity for a range of temperatures between 4.2 and 80 K. At higher temperatures, the resistivity indicates a Kondo-type behavior. The behavior of these quantities is accounted for by the magnetic phase transitions at 108 and 136 K reported from neutron-scattering studies. At high temperatures, the magnetic susceptibility of UPd[sub 2]Si[sub 2] is Curie-Wiess-like along the [ital c] axis. The temperature dependence of the Hall coefficient above 108 K is accounted for by a theoretical model invoking skew scattering of conduction electrons by localized magnetic moments.

1993-12-15

487

Recycler model magnet test on temperature compensation for strontium ferrite  

Energy Technology Data Exchange (ETDEWEB)

The Recycler ring magnet will be made of Strontium ferrite permanent magnets. A strontium ferrite permanent magnet without compensation has a temperature coefficient of -0.2 % in dB/dT. To compensate this effect, we are utilizing 30 % Ni 70 % Fe alloy, a temperature compensation ferromagnetic material with a low Curie point. To search for optimum commercially available material and optimum condition, we made a couple of simple model magnets, and tested with several different compensating material. The test results are reported and its optimal conditions are shown. Several different configurations were tested including a possible 2 kG magnet configuration.

1995-10-01

488

Large specific absorption rates in the magnetic hyperthermia properties of metallic iron nanocubes  

CERN Document Server

We report on the magnetic hyperthermia properties of chemically synthesized ferromagnetic 11 and 16 nm Fe(0) nanoparticles of cubic shape displaying the saturation magnetization of bulk iron. The specific absorption rate measured on 16 nm nanocubes is 1690+-160 W/g at 300 kHz and 66 mT. This corresponds to specific losses-per-cycle of 5.6 mJ/g, largely exceeding the ones reported in other systems. A way to quantify the degree of optimization of any system with respect to hyperthermia applications is proposed. Applied here, this method shows that our nanoparticles are not fully optimized, probably due to the strong influence of magnetic interactions on their magnetic response. Once protected from oxidation and further optimized, such nano-objects could constitute efficient magnetic cores for biomedical applications requiring very large heating power.

2010-01-01

489

Itinerant magnetism of Gd_xLa_1_-_xMSi (M=Fe, Co) compounds  

International Nuclear Information System (INIS)

The magnetic properties of polycrystalline and single crystalline rare earth transition metal silicides Gd_xLa_1_-_xMSi (M =Fe, Co) were investigated. Magnetic measurements have been made in static magnetic fields up to 13 kOe and in pulsed magnetic fields up to 250 kOe in the temperature range from 4.2 to 350 K. The magnetic susceptibility in the paramagnetic state of all the investigated compounds obeys the Curie-Weiss law except for LaFeSi and LaCoSi. Increase of the La content in Gd_xLa_1_-_xFeSi compounds leads to a decrease of the Curie and Neel temperatures, which can be explained by a decrease of positive exchange interactions. (orig.).

1995-09-01

490

High Tc superconducting magnetic multivibrators for fluxgate magnetic-field sensors  

Science.gov (United States)

Sensitive and quick-response nonlinear inductance characteristics are found for high Tc superconducting (YBa/sub 2/Cu/sub 3/O/sub 7-chi/) disk cores at 77K in which soft magnetic BH hysteresis loops are observed. Various quick response magnetic devices such as modulators, amplifiers and sensors are built using these cores. The magnetizing frequency can be set to more than 20 MHz, which is difficult for conventional ferromagnetic bulk materials such as Permalloy amorphous alloys and ferrite. New quick-response fluxgate type magnetic-field sensors are made using ac and dc voltage sources. The former is used for second-harmonic type sensors, while the latter is for voltage-output multivibrator type sensors. Stable and quick-response sensor characteristics were obtained for two-core type multivibrators.

1989-09-01

491

Effect of magnet sorting using a simple resonance cancellation method on the RMS orbit distortion at the APS injector synchrotron  

Energy Technology Data Exchange (ETDEWEB)

The Advanced Photon Source injector synchrotron is a 7-GeV positron machine with a standard alternating gradient lattice. The calculated effect of dipole magnet strength errors on the orbit distortion, simulated by Monte Carlo, was reduced by sorting pairs of magnets having the closest simulated measured strengths to reduce the driving the term of the integer resonance nearest the operating point. This method resulted in a factor of four average reduction in the rms orbit distortion when all 68 magnets were sorted at once. The simulated effect of magnet measurement experimental resolution was found to limit the actual improvement. The {Beta}-beat factors were similarly reduced by sorting the quadrupole magnets according to their gradients.

1993-07-01

492

Effect of On-Chip Magnetic Shielding for TES Microcalorimeters  

British Library Electronic Table of Contents (United Kingdom)

We investigated the magnet field dependence of the X-ray pulse height and the critical current of a Ti/Au bilayer TES micro-calorimeter. The pulse height was strongly affected by the magnetic field intensity applied perpendicularly to the TES surface. We found that the critical current at zero temperature, I c0, decreased by a factor of two by applying a magnet field of ?10??T. Our data are consistent with a TES sensitivity proportional to (I/I c0)?2/3, as predicted by the Ginzburg-Landau theory. This fact implies that the shape of the R?T curve of the TES is partly determined by the critical current of the superconductor. In order to make our TES microcalorimeters less sensitive to the external magnetic field, we fabricated devices equipped with on-chip magnetic shielding. One device has ...

2008-01-01

493

Design, Performance and Series Production of Superconducting Trim Quadrupoles for the Large Hadron Collider  

CERN Document Server

The Large Hadron Collider (LHC) will be equipped with several thousands of superconducting corrector magnets. Among the largest ones are the superconducting trim quadrupoles (MQTL). These twin-aperture magnets with a total mass of up to 1700 kg have a nominal gradient of 129 T/m at 1.9 K and a magnetic length of 1.3 m. Sixty MQTL are required for the LHC, 36 operating at 1.9 K in and 24 operating at 4.5 K. The paper describes the design features, and reports the measured quench performance and magnetic field quality of the production magnets. The MQTL magnet production is shared between CERN and industry. This sharing is simplified due to the modular construction, common to all twin-aperture correctors.

2006-01-01

494

The explicit Laplace transform for the Wishart process  

CERN Document Server

We derive the explicit formula for the joint Laplace transform of the Wishart process and its time integral which extends the original approach of Bru. We compare our methodology with the alternative results given by the variation of constants method, the linearization of the Matrix Riccati ODE's and the Runge-Kutta algorithm. The new formula turns out to be fast, accurate and very useful for applications when dealing with stochastic volatility and stochastic correlation modelling.

2011-01-01

495

Super schwarzian derivatives in N = 4 SU(2)-extended superconformal algebras  

Energy Technology Data Exchange (ETDEWEB)

The authors investigate anomalous terms in finite superconformal transformations in N = 4 SU(2)-extended superconformal algebras (SCA). Based on the superspace formalism they obtain super Schwarzian derivatives for the N = 4 SCA. Solutions for global superconformal transformations with the vanishing super-Schwarzian derivatives are given.

1990-05-10

496

Nuclear electromagnetic currents from chiral EFT  

International Nuclear Information System (INIS)

Using the method of unitary transformation in combination with chiral effective field theory we derive the pion exchange contributions to the two-nucleon electromagnetic current. A formal definition of the current operator in this scheme and the power counting is presented. We discuss the implications of additional unitary transformations that have to be present to ensure the renormalizability of the one-pion exchange current. Further, we give explicit and compact results for the current in coordinate-space.

2010-03-15

497

Four-nucleon force using the method of unitary transformation  

Energy Technology Data Exchange (ETDEWEB)

We discuss in detail the derivation of the leading four-nucleon force in chiral effective field theory using the method of unitary transformation. The resulting four-nucleon force is given in both momentum and configuration space. It does not contain any unknown parameters and can be used in few- and many-nucleon studies. (orig.)

2007-11-15

498

Duality rotations  

Energy Technology Data Exchange (ETDEWEB)

Irrespective of supersymmetry, it is interesting to understand the special properties of theories admitting duality rotations. The Lagrangian of such a theory is not invariant under the transformations, nor does it change by a total derivative, but it transforms in a particular way which implies that the system of the equations of motion is invariant and that observables, such as the energy momentum tensor and therefore the total energy and momentum, are invariant. The main results of a recent paper on the properties of theories admitting duality rotations written in collaboration with M. K. Gaillard (1981) are described.

1981-11-01

499

Carbide transformations in a gamma/gamma-prime nickel alloy during prolonged aging  

Energy Technology Data Exchange (ETDEWEB)

Carbide reactions occurring in a precipitation-hardening gamma/gamma-prime Ni-Cr alloy during prolonged high-temperature aging are investigated experimentally. It is found that the decomposition of primary MC carbides, which is accompanied by the precipitation of M23C6 particles, may lead to void nucleation and growth. The effect of carbide transformations on the residual properties of the material at temperatures above the equicohesion temperature is observed at the late stages of aging only. 6 references.

1988-08-01

500

Assessing the internal mechanical integrity of power transformers using vibration tests  

Energy Technology Data Exchange (ETDEWEB)

Machine condition monitoring (MCM) has the capability to predict equipment maintenance needs which can reduce forced down-time and facilitate the avoidance of catastrophic failures and the consequential secondary damage. It can be used to allow confident deferral of routine maintenance, and improve equipment performance, availability, reliability and safety. In order to capitalize on the potential benefits of MCM directed toward power transformers two types of vibration tests were conducted on transformers owned and operated by Cargill Inc. and IES Utilities at the Bridgeport corn plant in Eddyville, Iowa. These tests involved collecting vibration signals from the transformer tank walls during transformer energization at no-load and during steady state operation at various loads. These vibration signals were then used to detect deterioration of internal mechanical integrity. Both types of tests ...

1996-12-31