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1

Fast Resonant Extraction from the CERN SPS  

Microsoft Academic Search

Two different modes of fast resonant extraction are used at the SPS: non-coherent half-integer extraction with a spill duration from 1 ms to 3 ms and coherent half-integer extraction with a spill duration from about 70 ¿s (two 23 ¿s bursts separated by a 23 ¿s interval) to 1 ms. A special requirement is to stop a 2 ms spill

Karl Heinz Kissler; J. Riche; Walter Scandale; G. Schröder

1979-01-01

2

STATUS OF SLOW EXTRACTION OF HIGH INTENSITY PROTONS FROM BROOKHAVEN'S AGS.  

SciTech Connect

The Brookhaven AGS third integer resonant extraction system allows the AGS to provide high quality, high intensity 25.5 GeV/c proton beams simultaneously to four target stations and as many as 8 experiments. With the increasing intensities (over 7 x 10{sup 13} protons/pulse) and associated longer spill periods (2.4 to 3 seconds long), we continue to run with low losses and high quality low modulation continuous current beams. We have an active program of high energy physics experiments, including the high precision measurement of the muons magnetic moment [1] and the discovery of the rare Kaon decay, K+ {yields} {pi} + {nu}{bar {nu}} [2]. This program is continuing into the future with the rare symmetry violating process experiments [3] currently being designed to operate at the AGS. In this paper, we will present results from operation of high intensity slow extraction, the problems we encounter, and our solutions to those problems.

BROWN,K.A.AHRENS,L.BRENNAN,J.M.GLENN,J.W.ROSER,T.RUSSO,T.TSOUPAS,N.SMITH,K.ZENO,K.

2003-05-12

3

Automated Brain Extraction from T2-weighted Magnetic Resonance Images  

PubMed Central

Purpose To develop and implement an automated and robust technique to extract brain from T2-weighted images. Materials and Methods Magnetic resonance imaging (MRI) was performed on 75 adult volunteers to acquire dual fast spin echo (FSE) images with fat-saturation technique on a 3T Philips scanner. Histogram-derived thresholds were derived directly from the original images followed by the application of regional labeling, regional connectivity, and mathematical morphological operations to extract brain from axial late-echo FSE (T2-weighted) images. The proposed technique was evaluated subjectively by an expert and quantitatively using Bland-Altman plot and Jaccard and Dice similarity measures. Results Excellent agreement between the extracted brain volumes with the proposed technique and manual stripping by an expert was observed based on Bland-Altman plot and also as assessed by high similarity indices (Jaccard: 0.9825± 0.0045; Dice: 0.9912 ±0.0023). Conclusion Brain extraction using proposed automated methodology is robust and the results are reproducible.

Datta, Sushmita; Narayana, Ponnada A.

2011-01-01

4

Selective resonant extraction from the Fermilab Main Injector using electron lens  

SciTech Connect

We propose to use an electron lens for slow extraction of proton bunches from the Fermilab Main Injector. Negatively charged electron beam colliding with protons causes positive tune shift proportional to the electron current. If the resulting tune satisfies resonance condition, protons move to larger betatron amplitudes as in conventional slow extraction systems. Time variation of the electron current allows slow extraction from particular batches or even slow extraction from a single bunch.

Vladimir Shiltsev and John Marriner

2001-07-20

5

Antioxidant activity of grape skin aqueous extracts from pressurized hot water extraction combined with electron paramagnetic resonance spectroscopy.  

PubMed

Pressurized hot water extraction (PHWE) was employed to prepare extracts from dried grape skin of two wine grape varieties (St. Laurent and Alibernet) at various temperatures (from 40 up to 120°C) and amounts of sample (0.5, 1.0 and 1.5 g). To assess the antioxidant activity of the extracts, electron paramagnetic resonance (EPR) spectroscopy was applied involving DPPH and ABTS(+) assays. Other extract characteristics including HPLC profile of anthocyanins and total phenolic compound content were obtained as well. PHWE has also been compared with earlier results of extractions of the same grape skin samples with compressed methanol and compressed ethanol under the conditions of pressurized fluid extraction (PFE). From this comparison, PHWE emerges as the more benign and efficient extraction method to recover valuable phenolic antioxidants from grape skins for the prospective use in functional food supplements. PMID:21872083

S?avíková, Lenka; Polovka, Martin; Hohnová, Barbora; Karásek, Pavel; Roth, Michal

2011-09-30

6

Two-dimensional analyses related to wave-energy extraction by submerged resonant ducts  

Microsoft Academic Search

It is pointed out that submerged resonant ducts offer an approach to the design of wave-energy extraction devices consistent with the need for maximum seaworthiness. A full account is provided of one type of analysis of these systems, based upon two-dimensional wave hydrodynamics and linearized duct dynamics. One theoretical prediction is that the effective pressure fluctuations to which a resonant

James Lighthill

1979-01-01

7

Electron-beam extraction system for the Frankfurt 14 GHz electron cyclotron resonance ion source  

Microsoft Academic Search

A new concept to assist in the extraction of ion beams from an electron cyclotron resonance ion source (ECRIS) by the injection of an electron beam from the extraction side into the ion-source plasma is proposed. In this article, the construction of a test setup is described and first results of experiments with this setup at the 14 GHz ECRIS

S. Runkel; O. Hohn; L. Schmidt; K. E. Stiebing; H. Schmidt-Böcking; A. Schempp; R. Becker

1998-01-01

8

Extracting Low-Lying Lambda Resonances Using Correlation Matrix Techniques  

SciTech Connect

The lowest-lying negative-parity state of the Lambda is investigated in (2+1)-flavour full-QCD on the PACS-CS configurations made available through the ILDG. We show that a variational analysis using multiple source and sink smearings can extract a state lying lower than that obtained by using a standard fixed smeared source and sink operator alone.

Menadue, Benjamin J.; Kamleh, Waseem; Leinweber, Derek B.; Mahbub, M. S. [Special Research Centre for the Subatomic Structure of Matter, School of Chemistry and Physics, University of Adelaide (Australia)

2011-05-24

9

Magnification of photonic crystal fluorescence enhancement via TM resonance excitation and TE resonance extraction on a dielectric nanorod surface  

NASA Astrophysics Data System (ADS)

Using a one-dimensional grating surface photonic crystal (PC), we experimentally demonstrate that the detection of fluorescent molecules on a PC surface can be substantially magnified through the combined effects of resonance-enhanced excitation of the fluorescent dye, resonance-enhanced extraction of the fluorescence emission and a dielectric nanorod surface coating increasing the surface area available for fluorophore-PC interaction. Enhanced excitation is obtained by engineering a high-Q TM resonant mode to efficiently couple with an incident TM-polarized ? = 633 nm laser for exciting Cyanine-5 (Cy5). Enhanced extraction results from a low-Q TE resonance designed to spectrally overlap the Cy5 emission spectrum for channeling TE-polarized emission towards the detection instrument. The entire PC surface is coated with a porous film of TiO2 nanorods that allows more fluorophores to penetrate into the region of enhanced near-electric fields. Experimental results reveal a 588-fold enhancement in fluorescence intensity relative to an unpatterned glass surface.

Wu, Hsin-Yu; Zhang, Wei; Mathias, Patrick C.; Cunningham, Brian T.

2010-03-01

10

Brain development: 1 H magnetic resonance spectroscopy of rat brain extracts compared with chromatographic methods  

Microsoft Academic Search

We compared in vitro1H magnetic resonance spectroscopy (MRS) measurements of rat brain extracts (rats: 2–56 days old) with chromatographic measurements and in a further step also with results of in vivo MRS. The following substances can be reliably measured in brain extracts by in vitro MRS: N-acetylaspartate (NAA), total creatine (Cr), phosphorylethanoloamine (PE), taurine (Tau), glutamate (Glu), glutamine (Gln), ?-aminobutyrate

R. Burri; P. Bigler; P. Straehl; S. Posse; J-P Colombo; N. Herschkowitz

1990-01-01

11

Development of ion transportation, extraction and neutralization systems for atomic beam resonance method  

NASA Astrophysics Data System (ADS)

A device that produces a low-energy and largely spin polarized RI beam based on the atomic beam resonance method (RIABR) has been developed. We have performed measurements of stopping and drifting an incoming RI ion beam in a gas chamber, extraction of the ions into a vacuum region, and neutralization of the extracted low-energy ion beam. The drift efficiency of RI ions in a gas and the extraction efficiency at a Laval-type glass nozzle were found to be 0.72±0.04 and 0.033, respectively. The result of the experiment for the neutralization is also discussed.

Nagae, Daisuke; Asahi, Koichiro; Miyoshi, Hisanori; Shimada, Kenzi; Yoshimi, Akihiro; Ueno, Hideki; Murata, Jiro; Uchida, Makoto; Kameda, Daisuke; Kato, Go; Emori, Shoken; Kijima, Go; Oshima, Sachiko; Takemura, Makoto; Arai, Takemasa; Kobayashi, Yoshio; Haseyama, Tomohito; Schmidt-Ott, W. D.

2005-11-01

12

Soil and litter phosphorus-31 nuclear magnetic resonance spectroscopy: extractants, metals, and phosphorus relaxation times.  

PubMed

Phosphorus-31 nuclear magnetic resonance (NMR) spectroscopy is an excellent tool with which to study soil organic P, allowing quantitative, comparative analysis of P forms. However, for 31P NMR to be tative, all peaks must be completely visible, and in their correct relative proportions. There must be no line broadening, and adequate delay times must be used to avoid saturation of peaks. The objective of this study was to examine the effects of extractants on delay times and peak saturation. Two samples (a forest litter and a mineral soil sample) and three extractants (0.25 M NaOH, NaOH plus Chelex (Bio-Rad Laboratories, Hercules, CA), and NaOH plus EDTA) were used to determine the differences in the concentration of P and cations solubilized by each extractant, and to measure spin-lattice (T1) relaxation times of P peaks in each extract. For both soil and litter, NaOH-Chelex extracted the lowest concentrations of P. For the litter sample, T1 values were short for all extractants due to the high Fe concentration remaining after extraction. For the soil sample, there were noticeable differences among the extractants. The NaOH-Chelex sample had less Fe and Mn remaining in solution after extraction than the other extractants, and the longest delay times used in the study, 6.4 s, were not long enough for quantitative analysis. Delay times of 1.5 to 2 s for the NaOH and NaOH-EDTA were adequate. Line broadening was highest in the NaOH extracts, which had the highest concentration of Fe. On the basis of these results, recommendations for future analyses of soil and litter samples by solution 31P NMR spectroscopy include: careful selection of an extractant; measurement of paramagnetic ions extracted with P; use of appropriate delay times and the minimum number of scans; and measurement of T1 values whenever possible. PMID:11931434

Cade-Menun, B J; Liu, C W; Nunlist, R; McColl, J G

2002-01-01

13

Multiaperture ion beam extraction from gas-dynamic electron cyclotron resonance source of multicharged ions.  

PubMed

Electron cyclotron resonance ion source with quasi-gas-dynamic regime of plasma confinement (ReGIS), constructed at the Institute of Applied Physics, Russia, provides opportunities for extracting intense and high-brightness multicharged ion beams. Despite the short plasma lifetime in a magnetic trap of a ReGIS, the degree of multiple ionization may be significantly enhanced by the increase in power and frequency of the applied microwave radiation. The present work is focused on studying the intense beam quality of this source by the pepper-pot method. A single beamlet emittance measured by the pepper-pot method was found to be approximately 70 pi mm mrad, and the total extracted beam current obtained at 14 kV extraction voltage was approximately 25 mA. The results of the numerical simulations of ion beam extraction are found to be in good agreement with experimental data. PMID:18315107

Sidorov, A; Dorf, M; Zorin, V; Bokhanov, A; Izotov, I; Razin, S; Skalyga, V; Rossbach, J; Spädtke, P; Balabaev, A

2008-02-01

14

RNA degradation in cell extracts: real-time monitoring by fluorescence resonance energy transfer.  

PubMed

Short noncoding RNAs are increasingly recognized as key regulators of essential cellular processes such as RNA interference. A better understanding of the processes by which such RNAs are degraded is necessary to expand our knowledge of these processes and our ability to harness them. To this end we have developed a novel fluorescence resonance energy transfer (FRET) assay to monitor in real-time the degradation kinetics of short RNAs by a purified RNase and S100 cytosolic HeLa cell extract. An unstructured RNA is found to be degraded more rapidly than a stem-loop RNA under all conditions tested except for low concentrations of cell extract, showing that secondary structure confers protection against RNase activity. The assay also allows for the quantitative comparison of inhibitors such as Contrad70 and aurin tricarboxylic acid (ATA). Finally, gel electrophoretic FRET analysis confirms that HeLa cell extract is dominated by 5' to 3' exonucleolytic activity. PMID:14624543

Uhler, Sarah A; Cai, Dawen; Man, Yunfang; Figge, Carina; Walter, Nils G

2003-11-26

15

H- extraction from electron-cyclotron-resonance-driven multicusp volume source operated in pulsed mode  

NASA Astrophysics Data System (ADS)

H2 microwave (2.45 GHz) pulsed plasma is produced from seven elementary electron cyclotron resonance sources installed into the magnetic multipole chamber ``Camembert III'' (École Polytechnique-Palaiseau) from which H- extraction takes place. The negative-ion and electron extracted currents are studied through electrical measurements and the plasma parameters by means of electrostatic probe under various experimental conditions. The role of the plasma electrode bias and the discharge duty cycle in the extraction process is emphasized. The gas breakdown at the beginning of every pulse gives rise to variations of the plasma characteristic parameters in comparison with those established at the later time of the pulse, where the electron temperature, the plasma potential, and the floating potential converge to the values obtained for a continuous plasma. The electron density is significantly enhanced in the pulsed mode.

Svarnas, P.; Bacal, M.; Auvray, P.; Béchu, S.; Pelletier, J.

2006-03-01

16

A simple method for extracting material parameters of multilayered MEMS structures using resonance frequency measurements  

NASA Astrophysics Data System (ADS)

Multilayered structures are increasingly used in MEMS. Based on the resonant frequency of the doubly–clamped multilayered beam, the Young’s modulus and residual stress for an individual layer have been measured by designing beam test structures for each layer with different widths. Taking into account the buckling or no buckling problem of the multilayered beam, this paper introduces a model for the resonant frequency of the beam. An approach to extract the Young’s modulus and residual stress for the individual layer is developed. The validity of this approach has been studied using finite element modeling. As a multilayered example, test structures for a gold/polysilicon bilayer beam were fabricated. A scanning laser Doppler vibrometer system was used to measure the resonant frequency of the beam. The extracted parameters are that the average value of Young’s modulus of polysilicon and gold are 133.7?GPa and 78.6?GPa with standard deviation being 4.2?GPa and 11.5?GPa, respectively; the average value of residual stress of polysilicon and gold are 13.9?MPa (compressive) and 19.7?MPa (tensile) with standard deviation being 0.47?MPa and 4.4?MPa, respectively.

Sun, Chao; Zhou, Zai-Fa; Li, Wei-Hua; Huang, Qing-An

2014-07-01

17

The Extraction of Scattering Parameters and Resonance Properties for Quantum Electronic Devices  

NASA Astrophysics Data System (ADS)

Two new methods to determine scattering parameters and resonance properties, applicable variously to multidimensional reactive scattering and quantum electronic devices, are presented. They enable the efficient, and currently the fastest, handling of systems with both large and small dimensional Hamiltonians as well as those dominated by resonances. Both are "all-energy methods," yielding the required information at all energies of interest in one unified calculation, avoiding the time domain. They construct a set of solutions to the Schrodinger equation, without boundary restrictions, that need be valid only in the interaction region and an infinitesimal "edge" region immediately outside. Eventually put into integrals containing the potential, these yield the S-matrix. The methods require only real symmetric matrices. When the system and therefore the basis size is small, so that the Hamiltonian matrix fits into the computer's core memory, a single diagonalization of the real, symmetric Hamiltonian matrix is all the Spectral Projector (SP) method requires to extract the S-matrix. When large basis sets are necessitated, and the Hamiltonian matrix does not fit into the computer's core memory, this is amenable to a polynomial expansion which does not face the usual convergence problems. This is an iterative method, requiring only fast construction of the Hamiltonian matrix and and enables handling of systems with phonons, multibands, impurities and other device related problems requiring large basis sets. Involving only a basis set spanning the interaction region plus the very small edge region, the SP method is a minimal basis set method. The Stabilization method, enables immediate recognition of resonances and, though can do the full scattering problem, permits the extraction of quantities not involving detailed asymptotic without solving the full scattering problem. It will be used for evaluating resonance parameters, photodissociation cross sections and device conductance. It involves repeatedly diagonalizing Hamiltonian matrices in a series of boxes and, though not a minimal basis set method, is more efficient when narrow resonances exist. Combining a quick and sketchy Stabilization calculation for the resonance parameters with either the SP method or its variant may be the most efficient manner for determining device characteristics.

Ravuri, Tushar Ramamoorthy

1995-01-01

18

Padé methods for reconstruction and feature extraction in magnetic resonance imaging.  

PubMed

Methods utilizing Padé approximants are investigated for implementation with magnetic resonance imaging data and are presented both for direct image reconstruction and for feature extraction. Padé approximants are a numerical tool that can be used to accelerate the convergence of a slowly converging sequence by estimating the fully converged sequence values from early data points. Padé approximants can be calculated directly from k-space data by solving a set of linear matrix equations to produce signal values for any desired location in the image domain. This gives an estimate of the fully converged signal intensity at each pixel location in the image, raising the possibility of reconstructing a better estimate of the object from a reduced data set. These methods have been tested on phantom and human data both for image reconstruction and for feature extraction. In image reconstruction, considerable convergence acceleration can be achieved, with steep intensity boundaries reproduced in keeping with higher resolution reconstructions and oscillatory truncation artifact characteristic of Fourier reconstruction removed. The convergence acceleration is variable and there is the possibility of fine detail suppression when insufficient data are included. The use of Padé methods as a tool for feature extraction has shown good agreement with extraction from high-resolution reference data. In this approach the edge information comes intrinsically from Padé reconstruction. PMID:16254953

Callaghan, Martina F; Larkman, David J; Hajnal, Joseph V

2005-12-01

19

Model for the description of ion beam extraction from electron cyclotron resonance ion sources.  

PubMed

The finite difference method trajectory code KOBRA3-INP has been developed now for 25 years to perform the simulation of ion beam extraction in three dimensions. Meanwhile, the code has been validated for different applications: high current ion beam extraction from plasma sources for ion implantation technology, neutral gas heating in fusion devices, or ion thrusters for space propulsion. One major issue of the development of this code was to improve the flexibility of the applied model for the simulation of different types of particle sources. Fixed emitter sources might be simulated with that code as well as laser ion sources, Penning ion sources, electron cyclotron resonance ion sources (ECRISs), or H(-) sources, which require the simulation of negative ions, negative electrons, and positive charges simultaneously. The model which has been developed for ECRIS has now been used to explore the conditions for the ion beam extraction from a still nonexisting ion source, a so called ARC-ECRIS [P. Suominen and F. Wenander, Rev. Sci. Instrum. 79, 02A305 (2008)]. It has to be shown whether the plasma generator has similar properties like regular ECRIS. However, the emittance of the extracted beam seems to be much better compared to an ECRIS equipped with a hexapole. PMID:20192465

Spädtke, P

2010-02-01

20

Model for the description of ion beam extraction from electron cyclotron resonance ion sources  

SciTech Connect

The finite difference method trajectory code KOBRA3-INP has been developed now for 25 years to perform the simulation of ion beam extraction in three dimensions. Meanwhile, the code has been validated for different applications: high current ion beam extraction from plasma sources for ion implantation technology, neutral gas heating in fusion devices, or ion thrusters for space propulsion. One major issue of the development of this code was to improve the flexibility of the applied model for the simulation of different types of particle sources. Fixed emitter sources might be simulated with that code as well as laser ion sources, Penning ion sources, electron cyclotron resonance ion sources (ECRISs), or H{sup -} sources, which require the simulation of negative ions, negative electrons, and positive charges simultaneously. The model which has been developed for ECRIS has now been used to explore the conditions for the ion beam extraction from a still nonexisting ion source, a so called ARC-ECRIS [P. Suominen and F. Wenander, Rev. Sci. Instrum. 79, 02A305 (2008)]. It has to be shown whether the plasma generator has similar properties like regular ECRIS. However, the emittance of the extracted beam seems to be much better compared to an ECRIS equipped with a hexapole.

Spaedtke, P. [GSI Darmstadt, Planckstr. 1, 64221 Darmstadt (Germany)

2010-02-15

21

Model for the description of ion beam extraction from electron cyclotron resonance ion sources  

NASA Astrophysics Data System (ADS)

The finite difference method trajectory code KOBRA3-INP has been developed now for 25 years to perform the simulation of ion beam extraction in three dimensions. Meanwhile, the code has been validated for different applications: high current ion beam extraction from plasma sources for ion implantation technology, neutral gas heating in fusion devices, or ion thrusters for space propulsion. One major issue of the development of this code was to improve the flexibility of the applied model for the simulation of different types of particle sources. Fixed emitter sources might be simulated with that code as well as laser ion sources, Penning ion sources, electron cyclotron resonance ion sources (ECRISs), or H- sources, which require the simulation of negative ions, negative electrons, and positive charges simultaneously. The model which has been developed for ECRIS has now been used to explore the conditions for the ion beam extraction from a still nonexisting ion source, a so called ARC-ECRIS [P. Suominen and F. Wenander, Rev. Sci. Instrum. 79, 02A305 (2008)]. It has to be shown whether the plasma generator has similar properties like regular ECRIS. However, the emittance of the extracted beam seems to be much better compared to an ECRIS equipped with a hexapole.

Spädtke, P.

2010-02-01

22

a Method for Extracting the Resonance Parameters from Experimental Cross-Sections  

NASA Astrophysics Data System (ADS)

Within the proposed method, a set of experimental data points are fitted using a multi-channel S-matrix. Then the resonance parameters are located as its poles on an appropriate sheet of the Riemann surface of the energy. The main advantage of the method is that the S-matrix is constructed in such a way that it has proper analytic structure, i.e. for any number of two-body channels, the branching at all the channel thresholds is represented via exact analytic expressions in terms of the channel momenta. The way the S-matrix is constructed makes it possible not only to locate multi-channel resonances but also to extract their partial widths as well as to obtain the scattering cross-section in the channels for which no data are available. The efficiency of the method is demonstrated by two model examples of a single-channel and a two-channel problems, where known resonance parameters are rather accurately reproduced by fitting the pseudo-data artificially generated using the corresponding potentials.

Rakityansky, S. A.; Elander, N.

2013-05-01

23

Far-field Fano resonance in nanoring lattices modeled from extracted, point dipole polarizability  

NASA Astrophysics Data System (ADS)

Coupling and extinction of light among particles representable as point dipoles can be characterized using the coupled dipole approximation (CDA). The analytic form for dipole polarizability of spheroidal particles supports rapid electrodynamic analysis of nanoparticle lattices using CDA. However, computational expense increases for complex shapes with non-analytical polarizabilities which require discrete dipole (DDA) or higher order approximations. This work shows fast CDA analysis of assembled nanorings is possible using a single dipole nanoring polarizability extrapolated from a DDA calculation by summing contributions from individual polarizable volume elements. Plasmon resonance wavelengths of nanorings obtained using extracted polarizabilities blueshift as wall dimensions-to-inner radius aspect ratio increases, consistent with published theory and experiment. Calculated far-field Fano resonance energy maximum and minimum wavelengths were within 1% of full volume element results. Considering polarizability allows a more complete physical picture of predicting plasmon resonance location than metal dielectric alone. This method reduces time required for calculation of diffractive coupling more than 40 000-fold in ordered nanoring systems for 400-1400 nm incident wavelengths. Extension of this technique beyond nanorings is possible for more complex shapes that exhibit dipolar or quadrupole radiation patterns.

DeJarnette, Drew; Blake, Phillip; Forcherio, Gregory T.; Keith Roper, D.

2014-01-01

24

Investigations on the structure of the extracted ion beam from an electron cyclotron resonance ion source  

SciTech Connect

Using improved beam diagnostic tools, the structure of an ion beam extracted from an electron cyclotron resonance ion source (ECRIS) becomes visible. Especially viewing targets to display the beam profile and pepper pot devices for emittance measurements turned out to be very useful. On the contrary, diagnostic tools integrating over one space coordinate like wire harps for profile measurements or slit-slit devices, respectively slit-grid devices to measure the emittance might be applicable for beam transport investigations in a quadrupole channel, but are not very meaningful for investigations regarding the given ECRIS symmetry. Here we try to reproduce the experimentally found structure on the ion beam by simulation. For the simulation, a certain model has to be used to reproduce the experimental results. The model is also described in this paper.

Spaedtke, P.; Lang, R.; Maeder, J.; Rossbach, J.; Tinschert, K. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt (Germany); Maimone, F. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt (Germany); Universita degli Studi di Catania, D.M.F.C.I, Viale A. Doria 6, 95125 Catania (Italy)

2012-02-15

25

Extracting S-matrix poles for resonances from numerical scattering data: Type-II Padé reconstruction  

NASA Astrophysics Data System (ADS)

We present a FORTRAN 77 code for evaluation of resonance pole positions and residues of a numerical scattering matrix element in the complex energy (CE) as well as in the complex angular momentum (CAM) planes. Analytical continuation of the S-matrix element is performed by constructing a type-II Padé approximant from given physical values (Bessis et al. (1994) [42]; Vrinceanu et al. (2000) [24]; Sokolovski and Msezane (2004) [23]). The algorithm involves iterative 'preconditioning' of the numerical data by extracting its rapidly oscillating potential phase component. The code has the capability of adding non-analytical noise to the numerical data in order to select 'true' physical poles, investigate their stability and evaluate the accuracy of the reconstruction. It has an option of employing multiple-precision (MPFUN) package (Bailey (1993) [45]) developed by D.H. Bailey wherever double precision calculations fail due to a large number of input partial waves (energies) involved. The code has been successfully tested on several models, as well as the F + H 2 ? HF + H, F + HD ? HF + D, Cl + HCl ? ClH + Cl and H + D 2 ? HD + D reactions. Some detailed examples are given in the text. Program summaryProgram title: PADE II Catalogue identifier: AEHO_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEHO_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 19 959 No. of bytes in distributed program, including test data, etc.: 158 380 Distribution format: tar.gz Programming language: FORTRAN 77 Computer: Any computer equipped with a FORTRAN 90 compiler Operating system: UNIX, LINUX RAM: 256 Mb Classification: 16.8 External routines: NAG Program Library ( http://www.nag.co.uk/numeric/fl/FLdescription.asp) Nature of problem: The package extracts the positions and residues of resonance poles from numerical scattering data supplied by the user. The data can then be used for quantitative analysis of interference patterns observed in elastic, inelastic and reactive integral and differential cross sections. Solution method: The S-matrix element is analytically continued in the complex plane of either energy or angular momentum with the help of Padé approximation of type II. Resonance (complex energy or Regge) poles are identified and their residues evaluated. Unusual features: Use of multiple precision MPFUN package (Bailey (1993) [45]). (Distributed with the PADE II code.) Running time: From several seconds to several minutes depending on the precision level chosen and the number of iterations performed.

Sokolovski, D.; Akhmatskaya, E.; Sen, S. K.

2011-02-01

26

Third Interger Resonance Slow Extraction Using RFKO at High Space Charge  

SciTech Connect

A proposal to search for direct {mu} {yields} e conversion at Fermilab requires slow, resonant extraction of an intense proton beam. Large space charge forces will present challenges, partly due to the substantial betatron tune spread. The main challenges will be maintaining a uniform spill profile and moderate losses at the septum. We propose to use 'radio frequency knockout' (RFKO) for fine tuning the extraction. Strategies for the use of the RFKO method will be discussed here in the context of the Mu2e experiment. The feasibility of this method has been demonstrated in simulations. Tracking simulations show that optimal RFKO frequency modulation in case of the SC beam tune spread is substantially different from that of chromatic tune spread. FM should be centred at the bare betatron frequency rather than in the middle of the tune spread, and additional chromaticity must be added in order to facilitate rapid dilution of the dipole oscillations. Heating efficiency slowly decreases with the SC growing. Colored noise modulation (random signal within a given bandwidth) appears to be the most effective way of modulation, however its advantage over linear modulation is not very large, so practical reasons may prevail in the final choice between the two.

Nagaslaev, V.; Amundson, J.; Johnstone, J.; Park, C.S.; Werkema, S.; /Fermilab

2011-09-15

27

Ion beam extraction from electron cyclotron resonance ion sources and the subsequent low energy beam transport  

NASA Astrophysics Data System (ADS)

Electron Cyclotron Resonance Ion Sources (ECRIS) are capable of delivering high currents of Highly Charged Ions (HCIs) to heavy ion accelerators (e.g.: to the future FRIB). The use of a sextupole magnet for confinement of the plasma inside the source imposes a unique triangular structure on the beam. This, together with the multitude of ion species that are extracted at the same time and the high axial magnetic field at the plasma aperture, resulting from additional confining solenoids, make the simulation and design of ECRIS extraction systems particularly challenging. The first objective of this thesis was to refine and test a semi-empirical simulation model of the formation and extraction of HCIs from ECR ion sources as well as their transport through the subsequent Low Energy Beam Transport (LEBT) system. To this end, a set of utility functions was written to simplify performing the simulations. In the LEBT system, another interesting, yet so far unanswered, question arises: The influence of space-charge effects on the beam and the level of space-charge compensation in the ECRIS beam line. This interesting topic quickly became the second main objective of the thesis. A Retarding Field Analyzer (RFA) was built and systematic measurements of the neutralization level in ECRIS LEBT systems were done for the first time as part of this thesis (this intensity and pressure regime was previously not well explored). The measured neutralization levels for typical ECRIS beams were found to be between 0% and 50% and agreed reasonably well with a simple formula developed by Gabovich et al. for highly neutralized proton and H- beams after it was re-derived and extended in this thesis for low neutralization and multiple species. Preliminary tests of the refined and integrated simulation model for the ECR ion sources VENUS and SuSI and their respective low energy beam transport systems include comparisons of measured beam currents, cross sections and emittances with the simulation results. These tests suggest that the model is suited for the simulation of ion beam extraction and transport for medium to high charge states of medium to heavy ions, but not for the lowest charge states and lightest ions (He1+, protons). Finally, as an example application of the developed software, a variable-energy (300 kV - 3 MV) electrostatic accelerator was simulated and redesigned for the DIANA project, a new proposed underground laboratory for nuclear astrophysics.

Winklehner, Daniel

28

Electron spin resonance investigation of copper(II) complexation by fulvic acid extracted from sewage sludge  

SciTech Connect

Electron spin resonance (ESR) spectra are reported for copper(II)-fulvic acid complexes prepared with fulvic acid (FA) samples extracted from two different anaerobically-digested sewage sludges. In the original Cu-FA solutions, quadridentate, nearly square planar complexes with FA donor ligands could be inferred from the ESR spectra only at the smallest Cu/FA molar ratio, whereas at the intermediate ratios mixed Cu-FA-H2O complexes became more evident and at the highest ratio free CuS aquo-ions prevailed. The ESR spectra suggested the formation of inter-sphere, polydentate complexes, with the Cu(II) coordinated equatorially by oxygenated and nitrogenated FA ligands. No saturation of the Cu(II) complexation capacity was observed, but increasing the Cu content involved less and less reactive functional groups of FA in the coordination, shifting the complexation equilibria towards the formation of weaker complexes. A significant rearrangement of the Cu-FA systems was suggested to take place upon air-drying.

Senesi, N.; Bocian, D.F.; Sposito, G.

1985-01-01

29

Preliminary results of the ion extraction simulations applied to the MONO1000 and SUPERSHyPIE electron cyclotron resonance ion sources  

Microsoft Academic Search

The goal of this article is to present simulations on the extraction from an electron cyclotron resonance ion source (ECRIS). The aim of this work is to find out an extraction system, which allows one to reduce the emittances and to increase the current of the extracted ion beam at the focal point of the analyzing dipole. But first, we

C. Pierret; L. Maunoury; S. Biri; J. Y. Pacquet; O. Tuske; O. Delferriere

2008-01-01

30

Resonance  

NSDL National Science Digital Library

All About Circuits is a website that âÂÂprovides a series of online textbooks covering electricity and electronics.â Written by Tony R. Kuphaldt, the textbooks available here are wonderful resources for students, teachers, and anyone who is interested in learning more about electronics. This specific section, Resonance, is the sixth chapter in the Volume II textbook. Topics covered in this chapter include: electric pendulum, simple parallel resonance, simple series resonance, resonance in series-parallel circuits, and Q and bandwidth of a resonant circuit. Diagrams and detailed descriptions of concepts are included throughout the chapter to provide users with a comprehensive lesson. Visitors to the site are also encouraged to discuss concepts and topics using the All About Circuits discussion forums (registration with the site is required to post materials).

Kuphaldt, Tony R.

2008-07-07

31

Electron spin resonance study of free radicals formed from a procyanidin-rich pine ( Pinus maritima) bark extract, pycnogenol  

Microsoft Academic Search

The free radical generated from the oxidation of a French maritima pine bark extract Pycnogenol (PYC), by the horseradish peroxidase (HRP)–hydrogen peroxide (H2O2) system at pH 7.4–10.0 was studied using electron spin resonance (ESR) spectrometer. The formation rate of the PYC radical (aH = 0.92G; g = 2.0055) was dependent on the PYC and HRP concentrations and pH; the lifetime

Qiong Guo; Baolu Zhao; Lester Packer

1999-01-01

32

Detection of trinitrotoluene (TNT) extracted from soil using a surface plasmon resonance (SPR)-based sensor platform  

NASA Astrophysics Data System (ADS)

An antibody-based competition assay has been developed using a surface plasmon resonance (SPR) sensor platform for the detection of trinitrotoluene (TNT) in soil extract solutions. The objective of this work is to develop a sensor-based assay technology to use in the field for real- time detection of land mines. This immunoassay combines very simple bio-film attachment procedures and a low-cost SPR sensor design to detect TNT in soil extracts. The active bio-surface is a coating of bovine serum albumin that has been decorated with trinitrobenzene groups. A blind study on extracts from a large soil matrix was recently performed and result from this study will be presented. Potential interferant studied included 2,4-dinitrophenol, 2,4- dinitrotoluene, ammonium nitrate, and 2,4- dichlorophenoxyacetic acid. Cross-reactivity with dinitrotoluene will be discussed. Also, plans to reach sensitivity levels of 1ppb TNT in soil will be described.

Strong, Anita A.; Stimpson, Donald I.; Bartholomew, Dwight U.; Jenkins, Thomas F.; Elkind, Jerome L.

1999-08-01

33

Advanced light ion source extraction system for a new electron cyclotron resonance ion source geometry at Saclay.  

PubMed

One of the main goal of intense light ion injector projects such as IPHI, IFMIF, or SPIRAL2, is to produce high current beams while keeping transverse emittance as low as possible. To prevent emittance growth induced in a dual solenoid low energy transfer line, its length has to be minimized. This can be performed with the advanced light ion source extraction system concept that we are developing: a new ECR 2.45 GHz type ion source based on the use of an additional low energy beam transport (LEBT) short length solenoid close to the extraction aperture to create the resonance in the plasma chamber. The geometry of the source has been considerably modified to allow easy maintenance of each component and to save space in front of the extraction. The source aims to be very flexible and to be able to extract high current ion beams at energy up to 100 kV. A specific experimental setup for this source is under installation on the BETSI test bench, to compare its performances with sources developed up to now in the laboratory, such as SILHI, IFMIF, or SPIRAL2 ECR sources. This original extraction source concept is presented, as well as electromagnetic simulations with OPERA-2D code. Ion beam extraction in space charge compensation regime with AXCEL, and beam dynamics simulation with SOLMAXP codes show the beam quality improvement at the end of the LEBT. PMID:22380154

Delferrière, O; Gobin, R; Harrault, F; Nyckees, S; Sauce, Y; Tuske, O

2012-02-01

34

Seasonal variations of global lightning activity extracted from Schumann resonances using a genetic algorithm method  

Microsoft Academic Search

A three-dimensional Finite Difference Time Domain (FDTD) model of the Earth-ionosphere cavity with a realistic conductivity profile is employed to study the global lightning activity using the observed intensity variations of Schumann resonances (SR). Comparison of the results derived from our FDTD model and the previous studies by other authors on related subjects shows that Schumann resonance is a good

Heng Yang; Victor P. Pasko; Gabriella Sátori

2009-01-01

35

Electron cyclotron resonance 140 mA D{sup +} beam extraction optimization for IFMIF EVEDA accelerator  

SciTech Connect

Based on the experience of the SILHI electron cyclotron resonance (ECR) ion source for the IPHI accelerator, which produces routinely 100-120 mA H{sup +} beam, the CEA-Saclay is in charge of the design and realization of the 140 mA cw deuteron source for the IFMIF project (International Fusion Materials Irradiation Facility). IFMIF is an accelerator-based neutron irradiation facility consisting of two accelerators of 125 mA D{sup +} beam at 40 MeV that hit in parallel a lithium target. IFMIF utilizes the deuteron-lithium (d-Li) neutron, producing a reaction to simulate the 14 MeV neutron environment in deuterium-tritium (D-T) fusion reactors. In the framework of the IFMIF EVEDA phase (Engineering Validation and Engineering Design Activities), we are studying a cw ECR ion source with a new extraction system to allow high current extraction while keeping a low divergence as well as a small emittance. Starting from SILHI five-electrode system with H{sup +} ions, the extracted beam characteristics as well as electric field conditions are compared with the cases of four- and three-electrode extraction systems. Experimental results made on the SILHI source with H{sup +} ions are briefly discussed. Extensive experimental results on the new source test bench BETSI are expected as soon as the design and fabrication of a dedicated extraction system with a new set of electrodes will be finished.

Delferriere, O.; De Menezes, D.; Gobin, R.; Harrault, F.; Tuske, O. [Commissariat a l'Energie Atomique (CEA)-Saclay, DSM/DAPNIA, 91191 Gif sur Yvette Cedex (France)

2008-02-15

36

Power penalty measurement and frequency chirp extraction in silicon microdisk resonator modulators.  

SciTech Connect

We demonstrate 5 Gbs and 10 Gbs error free operation of silicon photonic microdisk resonant modulators to a distance of 70 km, measure dispersion power penalties and compare the experimental results with theoretically derived values.

Lentine, Anthony L.; Zortman, William A.; Trotter, Douglas Chandler; Watts, Michael R.

2010-03-01

37

Model-independent extraction of the pole and Breit-Wigner resonance parameters.  

PubMed

We show that a slightly modified Breit-Wigner formula can successfully describe the total cross section even for the broad resonances, from the light ?(770) to the heavy Z boson. In addition to the mass, width, and branching fraction, we include another resonance parameter that turns out to be directly related to the pole residue phase. The new formula has two mathematically equivalent forms: one with the pole and the other with the Breit-Wigner parameters. PMID:24074077

Ceci, S; Korolija, M; Zauner, B

2013-09-13

38

P_11 Resonance Extracted from pi-N Data and Its Stability  

SciTech Connect

We study the stability of resonance poles in {pi}N P{sub 11} partial wave, particularly the Roper resonance, by varying parameters significantly within the EBAC dynamical coupled-channels model, keeping a good fit to the empirical amplitude. We find that two Roper poles are stable against the variation. However, for higher energies, the number of poles can change depending on how the parameters are fitted within error bars. We also developed a model with a bare nucleon which forms the physical nucleon by being dressed by the meson-cloud. We still find a good stability of the Roper poles.

Satoshi Nakamura

2012-04-01

39

Automatic segmentation of the bone and extraction of the bone cartilage interface from magnetic resonance images of the knee  

NASA Astrophysics Data System (ADS)

The accurate segmentation of the articular cartilages from magnetic resonance (MR) images of the knee is important for clinical studies and drug trials into conditions like osteoarthritis. Currently, segmentations are obtained using time-consuming manual or semi-automatic algorithms which have high inter- and intra-observer variabilities. This paper presents an important step towards obtaining automatic and accurate segmentations of the cartilages, namely an approach to automatically segment the bones and extract the bone-cartilage interfaces (BCI) in the knee. The segmentation is performed using three-dimensional active shape models, which are initialized using an affine registration to an atlas. The BCI are then extracted using image information and prior knowledge about the likelihood of each point belonging to the interface. The accuracy and robustness of the approach was experimentally validated using an MR database of fat suppressed spoiled gradient recall images. The (femur, tibia, patella) bone segmentation had a median Dice similarity coefficient of (0.96, 0.96, 0.89) and an average point-to-surface error of 0.16 mm on the BCI. The extracted BCI had a median surface overlap of 0.94 with the real interface, demonstrating its usefulness for subsequent cartilage segmentation or quantitative analysis.

Fripp, Jurgen; Crozier, Stuart; Warfield, Simon K.; Ourselin, Sébastien

2007-03-01

40

Resolution of the multichannel anomaly in the extraction of S-matrix resonance-pole parameters  

SciTech Connect

Within the framework of a mathematically well-defined coupled-channel T-matrix model we have improved the existing multichannel pole-extraction procedure based on the numerical analytic continuation of the channel propagator, and for the first time we present the full set of pole parameters for already published amplitudes. Standard single-channel pole-extraction method (speed plot) was then applied to those amplitudes and resulting sets of T-matrix poles were inspected. The anomaly has been established that in some partial waves the pole values extracted using the standard single-channel methods differ not only from the values obtained using the analytic continuation method, but also change from one reaction to another. Inspired by this peculiarity, we have developed a new single-channel pole-extraction method based solely on the assumption of the partial wave analyticity. Since the speed plot turns out to be the lowest order term of the proposed method, the anomaly is understood and resolved.

Ceci, Sasa [Rudjer Boskovic Institute, Bijenicka cesta 54, P.O. Box 180, 10002 Zagreb (Croatia); Department of Physics and Astronomy, University of Georgia, Athens, GA 30602 (United States); Stahov, Jugoslav [Abilene Christian University, ACU Station Box 27963, Abilene, TX 79699 (United States); University of Tuzla, Faculty of Science, Univerzitetska 4, 35000 Tuzla (Bosnia and Herzegowina); Svarc, Alfred; Zauner, Branimir [Rudjer Boskovic Institute, Bijenicka cesta 54, P.O. Box 180, 10002 Zagreb (Croatia); Watson, Shon [Abilene Christian University, ACU Station Box 27963, Abilene, TX 79699 (United States)

2008-06-01

41

Results of Nucleon Resonance Extraction via Dynamical Coupled-Channels Analysis from #11;Collaboration @ EBAC  

SciTech Connect

We review a global analysis of meson production reactions off the nucleons by a collaboration at Excited Baryon Analysis Center of Jefferson Lab. The analysis is pursued with a dynamical coupled-channels approach, within which the dynamics of multi-channel reaction processes are taken into account in a fully consistent way with the two-body as well as three-body unitarity of the S-matrix. With this approach, new features of nucleon excitations are revealed as resonant particles originating from the non-trivial multi-channel reaction dynamics, which cannot be addressed by static hadron models where the nucleon excitations are treated as stable particles.

Hiroyuki Kamano

2012-04-01

42

Analysis of lipids in crude extracts by 13C nuclear magnetic resonance.  

PubMed

Phospho- and glycolipids with mono- or polyunsaturated fatty acid chains, free and acylated steroids, carotenes and carotenoids, chlorophylls, and related pheophytins were detected in crude extracts by NMR spectroscopy without any need for prior separation. A broad range of molecules belonging to different lipid classes could be identified in one-dimensional 13C NMR spectra obtained by applying a polarization transfer pulse sequence (DEPT 135 degrees). Directly detected or 1H-detected two-dimensional heterocorrelated NMR experiments were performed to facilitate the assignment of peaks arising from carotenoids, unsaturated fatty acid chains, and chlorophylls. 13C NMR data of crude lipid extracts from the macroalagae Ulva rigida and Fucus virsoides are shown to yield an informative overview of their lipid content. NMR is thus proposed as a simple, nonselective, and nondestructive technique for the first screening of the main lipid classes in complex lipid mixtures. PMID:8250229

Pollesello, P; Toffanin, R; Eriksson, O; Kilpeläinen, I; Hynninen, P H; Paoletti, S; Saris, N E

1993-10-01

43

Influence of frequency tuning and double-frequency heating on ions extracted from an electron cyclotron resonance ion source  

SciTech Connect

The electromagnetic field within the plasma chamber of an electron cyclotron resonance ion source (ECRIS) and the properties of the plasma waves affect the plasma properties and ion beam production. We have experimentally investigated the ''frequency tuning effect'' and ''double frequency heating'' on the CAPRICE ECRIS device. A traveling wave tube amplifier, two microwave sweep generators, and a dedicated experimental set-up were used to carry out experiments in the 12.5-16.5 GHz frequency range. During the frequency sweeps the evolution of the intensity and shape of the extracted argon beam were measured together with the microwave reflection coefficient. A range of different ion source parameter settings was used. Here we describe these experiments and the resultant improved understanding of these operational modes of the ECR ion source.

Maimone, F. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt (Germany); Universita degli Studi di Catania, D.M.F.C.I,Viale A. Doria 6, 95125 Catania (Italy); Celona, L. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Lang, R.; Maeder, J.; Rossbach, J.; Spaedtke, P.; Tinschert, K. [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Planckstr. 1, 64291 Darmstadt (Germany)

2011-12-15

44

Studies of emittance of multiply charged ions extracted from high temperature superconducting electron cyclotron resonance ion source, PKDELIS  

SciTech Connect

For the high current injector project at Inter University Accelerator Centre, a high temperature superconducting electron cyclotron resonance (ECR) ion source, PKDELIS, would provide the high charge state ions. The emittance of the ECR ion source is an important parameter to design further beam transport system and to match the acceptances of the downstream radio frequency quadrupole and drift tube linac accelerators of the high current injector. The emittance of the analyzed beam of PKDELIS ECR source has been measured utilizing the three beam size technique. A slit and two beam profile monitors positioned at fixed distances from each other were used to measure the beam size. The digitized beam profiles have been analyzed to determine the emittance of various multiply charged ions. The variation of emittance with gas mixing, ultrahigh frequency power, and extraction energy are discussed in this presentation.

Rodrigues, G.; Lakshmy, P. S.; Kumar, Sarvesh; Mandal, A.; Kanjilal, D.; Roy, A. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067 (India); Baskaran, R. [Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamilnadu 603102 (India)

2010-02-15

45

Studies of emittance of multiply charged ions extracted from high temperature superconducting electron cyclotron resonance ion source, PKDELIS.  

PubMed

For the high current injector project at Inter University Accelerator Centre, a high temperature superconducting electron cyclotron resonance (ECR) ion source, PKDELIS, would provide the high charge state ions. The emittance of the ECR ion source is an important parameter to design further beam transport system and to match the acceptances of the downstream radio frequency quadrupole and drift tube linac accelerators of the high current injector. The emittance of the analyzed beam of PKDELIS ECR source has been measured utilizing the three beam size technique. A slit and two beam profile monitors positioned at fixed distances from each other were used to measure the beam size. The digitized beam profiles have been analyzed to determine the emittance of various multiply charged ions. The variation of emittance with gas mixing, ultrahigh frequency power, and extraction energy are discussed in this presentation. PMID:20192453

Rodrigues, G; Lakshmy, P S; Kumar, Sarvesh; Mandal, A; Kanjilal, D; Baskaran, R; Roy, A

2010-02-01

46

Studies of emittance of multiply charged ions extracted from high temperature superconducting electron cyclotron resonance ion source, PKDELIS  

NASA Astrophysics Data System (ADS)

For the high current injector project at Inter University Accelerator Centre, a high temperature superconducting electron cyclotron resonance (ECR) ion source, PKDELIS, would provide the high charge state ions. The emittance of the ECR ion source is an important parameter to design further beam transport system and to match the acceptances of the downstream radio frequency quadrupole and drift tube linac accelerators of the high current injector. The emittance of the analyzed beam of PKDELIS ECR source has been measured utilizing the three beam size technique. A slit and two beam profile monitors positioned at fixed distances from each other were used to measure the beam size. The digitized beam profiles have been analyzed to determine the emittance of various multiply charged ions. The variation of emittance with gas mixing, ultrahigh frequency power, and extraction energy are discussed in this presentation.

Rodrigues, G.; Lakshmy, P. S.; Kumar, Sarvesh; Mandal, A.; Kanjilal, D.; Baskaran, R.; Roy, A.

2010-02-01

47

Extraction of anti-analog giant dipole resonance and neutron skin thickness for 208Pb  

NASA Astrophysics Data System (ADS)

The anti-analog giant dipole resonance (AGDR) was separated from other excitations such as the spin-dipole resonance by multipole decomposition analysis of the ^{208}Pb(vec {p},vec {n}) reaction at a bombarding energy of T_p=296 {MeV}. The polarization transfer observables were found to be useful for carrying out this separation. The energy difference between the AGDR and the isobaric analog state (IAS) was determined to be ?E = 8.69 ± 0.36 MeV, where the uncertainty includes both statistical and systematic contributions. Theoretical calculations using the proton-neutron relativistic quasi-particle random phase approximation predicted a strong correlation between ? E and the neutron skin thickness ? R_{pn}. Under the assumption that the correlation predicted in this model is correct, the present ? E value corresponds to a neutron skin thickness of ? R_{pn}=0.216± 0.046± 0.015 fm, where the first and second uncertainties are the experimental and theoretical uncertainties, respectively.

Yasuda, Jumpei; Wakasa, Tomotsugu; Okamoto, Midori; Dozono, Masanori; Hatanaka, Kichiji; Ichimura, Munetake; Kuroita, Sho; Maeda, Yukie; Noro, Tetsuo; Sakemi, Yasuhiro; Sasano, Masaki; Yako, Kentaro

2013-06-01

48

A UV resonance Raman (UVRR) spectroscopic study on the extractable compounds in Scots pine ( Pinus sylvestris) wood . Part II. Hydrophilic compounds  

NASA Astrophysics Data System (ADS)

Hydrophilic extracts of Scots pine ( Pinus sylvestris) heartwood and sapwood and a solid Scots pine knotwood sample were studied by UV resonance Raman spectroscopy (UVRRS). In addition, UVRR spectra of two hydrophilic model compounds (pinosylvin and chrysin) were analysed. UV Raman spectra were collected using 244 and 257 nm excitation wavelengths. The chemical composition of the acetone:water (95:5 v/v) extracts were also determined by gas chromatography. The aromatic and oleophilic structures of pinosylvin and chrysin showed three intense resonance enhanced bands in the spectral region of 1649-1548 cm -1. Pinosylvin showed also a relatively intense band in the aromatic substitution region at 996 cm -1. The spectra of the heartwood acetone:water extract showed many bands typical of pinosylvin. In addition, the extract included bands distinctive for resin and fatty acids. The sapwood acetone:water extract showed bands due to oleophilic structures at 1655-1650 cm -1. The extract probably also contained oligomeric lignans because the UVRR spectra were in parts similar to that of guaiacyl lignin. The characteristic band of pinosylvin (996 cm -1) was detected in the UVRR spectrum of the resin rich knotwood. In addition, several other bands typical for wood resin were observed, which indicated that the wood resin in the knotwood was resonance enhanced even more than lignin.

Nuopponen, M.; Willför, S.; Jääskeläinen, A.-S.; Vuorinen, T.

2004-11-01

49

Efficient Screening of Marine Extracts for Protease Inhibitors by Combining FRET Based Activity Assays and Surface Plasmon Resonance Spectroscopy Based Binding Assays  

PubMed Central

The screening of extracts from marine organisms is a widely used strategy to discover new drug leads. A common problem in the screening process is the generation of false positive hits through unspecific effects from the complex chemical composition of the crude extracts. In this study, we explored a combination of a fluorescence resonance energy transfer (FRET) based activity assay and a surface plasmon resonance (SPR) based binding assay to avoid this problem. An aqueous extract was prepared from rest raw material of the Norwegian spring spawning herring, and further fractionated by methanol solubility and solid phase extraction. FRET based activity assays were used to determine the influence of each extract on the activity of different proteases. Several extracts showed more than 50% inhibition. The inhibition mechanisms were elucidated by SPR based competition experiments with known inhibitors. For the secreted aspartic proteases 1, 2, 3 and HIV-1 protease, the results indicated that some extracts contain inhibitors interacting specifically with the active site of the enzymes. The study shows that a combination of an activity assay and an SPR based binding assay is a powerful tool to identify potent inhibitors in marine extracts. Furthermore, the study shows that marine vertebrates offer an interesting source for new bioactive compounds, although they have rarely been explored for this purpose.

Christopeit, Tony; ?verb?, Kersti; Danielson, U. Helena; Nilsen, Inge W.

2013-01-01

50

Extraction of Resonance Parameters and Role of the Final State Interactions  

NASA Astrophysics Data System (ADS)

We present an overview of the SAID group effort to analyze new ?n ? ?-p cross sections vs. the world database to get new multipoles and determine neutron electromagnetic couplings. The differential cross section for the processes ?n ? ?-p was extracted from new measurements at CLAS and MAMI-B accounting for Fermi motion effects in the impulse approximation (IA) as well as NN- and ?N-FSI effects beyond the IA. We evaluated results of several pion photoproduction analyses and compared ?N PWA results as a constraint for analyses of pion photoproduction data (Watson's theorem).

Strakovsky, Igor I.; Briscoe, William J.; Kudryavtsev, Alexander E.; Tarasov, Vladimir E.

2014-01-01

51

Chemical identification strategies using liquid chromatography-photodiode array-solid-phase extraction-nuclear magnetic resonance/mass spectrometry.  

PubMed

The identification of metabolites in biochemical studies is a major bottleneck in the proliferating field of metabolomics. In particular in plant metabolomics, given the diversity and abundance of endogenous secondary metabolites in plants, the identification of these is not only challenging but also essential to understanding their biological role in the plant, and their value to quality and nutritional attributes as food crops. With the new generation of analytical technologies, in which liquid chromatography (LC)-mass spectrometry (MS) and nuclear magnetic resonance (NMR) play a pioneering role, profiling metabolites in complex extracts is feasible at high throughput. However, the identification of key metabolites remains a limitation given the analytical effort necessary for traditional structural elucidation strategies. The hyphenation of LC-solid phase extraction (SPE)-NMR is a powerful analytical platform for isolating and concentrating metabolites for unequivocal identification by NMR measurements. The combination with LC-MS is a relatively straightforward approach to obtaining all necessary information for structural elucidation. Using this set-up, we could, as an example, readily identify five related glycosylated phenolic acids present in broccoli (Brassica oleracea, group Italica, cv Monaco): 1,2-di-O-E-sinapoyl-?-gentiobiose, 1-O-E-sinapoyl-2-O-E-feruloyl-?-gentiobiose, 1,2-di-O-E-feruloyl-?-gentiobiose, 1,2,2'-tri-O-E-sinapoyl-?-gentiobiose, and 1,2'-di-O-E-sinapoyl-2-O-E-feruloyl-?-gentiobiose. PMID:22351183

Moco, Sofia; Vervoort, Jacques

2012-01-01

52

Experimental Study of Resonance Radiation Trapping as a Method of Gain Improvement for Efficient Power Extraction from the XeF Blue-Green Laser Transition.  

National Technical Information Service (NTIS)

An experimental study has been carried out to explore the possibility of utilizing resonance radiation trapping as a method of gain improvement for efficient power extraction from the XeF C yield A blue-green laser transition. The experiment involved plac...

S. C. Lin

1981-01-01

53

Electron spin resonance study of free radicals formed from a procyanidin-rich pine (Pinus maritima) bark extract, pycnogenol.  

PubMed

The free radical generated from the oxidation of a French maritima pine bark extract Pycnogenol (PYC), by the horseradish peroxidase (HRP)-hydrogen peroxide (H2O2) system at pH 7.4-10.0 was studied using electron spin resonance (ESR) spectrometer. The formation rate of the PYC radical (aH = 0.92 G; g = 2.0055) was dependent on the PYC and HRP concentrations and pH; the lifetime of the radical was up to 90 min. Furthermore, it was found that the PYC radical was mainly composed of the secondary radical formed from procyanidin B3, one of major procyanidins in PYC. The primary radical signal of procyanidin B3 with hyperfine splitting constants aH = 3.67 G (1H), aH = 0.92 G (3H), and g = 2.0055 was transient and disappeared quickly, whereas its secondary radical signal appeared and increased with time. The secondary radical from dimer procyanidin B3 showed quite high stability, differing from the radical from monomer (+)-catechin that could not be observed possibly because of its instability. These results provide evidence to support the idea that the intramolecular hydrogen bond between the O* at the 4' position in one B ring and an OH group in the other B ring of procyanidin B3 is formed during its oxidation in the presence of HRP and H2O2. PMID:10641725

Guo, Q; Zhao, B; Packer, L

1999-12-01

54

Extraction of chili, black pepper, and ginger with near-critical CO2, propane, and dimethyl ether: analysis of the extracts by quantitative nuclear magnetic resonance.  

PubMed

Ginger, black pepper, and chili powder were extracted using near-critical carbon dioxide, propane, and dimethyl ether on a laboratory scale to determine the overall yield and extraction efficiency for selected pungent components. The temperature dependency of extraction yield and efficiency was also determined for black pepper and chili using propane and dimethyl ether. The pungency of the extracts was determined by using an NMR technique developed for this work. The volatiles contents of ginger and black pepper extracts were also determined. Extraction of all spice types was carried out with acetone to compare overall yields. Subcritical dimethyl ether was as effective at extracting the pungent principles from the spices as supercritical carbon dioxide, although a substantial amount of water was also extracted. Subcritical propane was the least effective solvent. All solvents quantitatively extracted the gingerols from ginger. The yields of capsaicins obtained by supercritical CO(2) and dimethyl ether were similar and approximately double that extracted by propane. The yield of piperines obtained by propane extraction of black pepper was low at approximately 10% of that achieved with dimethyl ether and CO(2), but improved with increasing extraction temperature. PMID:12903935

Catchpole, Owen J; Grey, John B; Perry, Nigel B; Burgess, Elaine J; Redmond, Wayne A; Porter, Noel G

2003-08-13

55

Characterisation of commercially available linear alkylbenzenesulfonates by LC-SPE-NMR\\/MS (liquid chromatography-solid phase extraction-nuclear magnetic resonance spectroscopy-mass spectroscopy)  

Microsoft Academic Search

Commercially available linear alkylbenzenesulfonates (LASs) are a mixture of various homologues and isomers, leading to 20 major species. In this work we investigated the commercial product by liquid chromatography-solid phase extraction-nuclear magnetic resonance spectroscopy-mass spectrometry (LC-SPE-NMR\\/MS). The commercial product was separated into 17 fractions by liquid chromatography (LC). After chromatographic separation, 5% of the flow was split to a mass

S. Schmidt; C. Piechotta; M. Godejohann; T. Win; I. Nehls; C. Mügge

2010-01-01

56

Preliminary results of the ion extraction simulations applied to the MONO1000 and SUPERSHyPIE electron cyclotron resonance ion sources  

NASA Astrophysics Data System (ADS)

The goal of this article is to present simulations on the extraction from an electron cyclotron resonance ion source (ECRIS). The aim of this work is to find out an extraction system, which allows one to reduce the emittances and to increase the current of the extracted ion beam at the focal point of the analyzing dipole. But first, we should locate the correct software which is able to reproduce the specific physics of an ion beam. To perform the simulations, the following softwares have been tested: SIMION 3D, AXCEL, CPO 3D, and especially, for the magnetic field calculation, MATHEMATICA coupled with the RADIA module. Emittance calculations have been done with two types of ECRIS: one with a hexapole and one without a hexapole, and the difference will be discussed.

Pierret, C.; Maunoury, L.; Biri, S.; Pacquet, J. Y.; Tuske, O.; Delferriere, O.

2008-02-01

57

Studies of extraction and transport system for highly charged ion beam of 18 GHz superconducting electron cyclotron resonance ion source at Research Center for Nuclear Physicsa)  

NASA Astrophysics Data System (ADS)

An 18 GHz superconducting electron cyclotron resonance ion source is installed to increase beam currents and to extend the variety of ions especially for highly charged heavy ions which can be accelerated by cyclotrons of Research Center for Nuclear Physics (RCNP), Osaka University. The beam production developments of several ions from B to Xe have been already done [T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H.Okamura, and A. Tamii, Rev. Sci. Instrum. 79, 02A311 (2008) and T. Yorita, K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, H.Okamura, and A. Tamii, Rev. Sci. Instrum. 81, 02A332 (2010)] and the further studies for those beam extraction and its transport have been done in order to increase the beam current more. The plasma electrode, extraction electrode, and einzel lens are modified. Especially extraction electrode can be applied minus voltage for the beam extraction and it works well to improve the extracted beam current. The extraction voltage dependences of transmission and emittance also have been studied for beam current improvement which is injected into azimuthally varying field cyclotron at RCNP.

Yorita, T.; Hatanaka, K.; Fukuda, M.; Ueda, H.; Yasuda, Y.; Morinobu, S.; Tamii, A.; Kamakura, K.

2014-02-01

58

New opportunities of the application of natural herb and spice extracts in plant oils: application of electron paramagnetic resonance in examining the oxidative stability.  

PubMed

The aim of this study was to establish the applicability of natural water-ethanol extracts of herbs and spices in increasing the oxidative stability of plant oils and in the production of novel food. Different concentrations (0, 100, 300, 500, and 700 ppm) of spice extracts and butylated hydroxyanisole (BHA) (100 ppm) were added to the studied oils. The antioxidant activity of spice extracts was determined with electron paramagnetic resonance (EPR) spectroscopy using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical assay. The study showed that the extracts significantly increased the oxidative stability of the examined oils when compared to one of the strongest synthetic antioxidants--BHA. The applied simple production technology and addition of herb and spice extracts to plant oils enabled enhancement of their oxidative stability. The extracts are an alternative to the oils aromatized with an addition of fresh herbs, spices, and vegetables because it did not generate additional flavors thus enabling the maintenance of the characteristic ones. Moreover, it will increase the intake of natural substances in human diet, which are known to possess anticarcinogenic properties. PMID:22900972

Koz?owska, Mariola; Szterk, Arkadiusz; Zawada, Katarzyna; Z?bkowski, Tomasz

2012-09-01

59

Direct assessment by electron spin resonance spectroscopy of the antioxidant effects of French maritime pine bark extract in the maxillofacial region of hairless mice  

PubMed Central

Flavangenol, one of extract of French maritime pine bark, is a complex mixture of bioflavonoids with oligometric proanthocyanidins as the major constituents. These constituents, catechin and procyanidin B1, are water-soluble derivatives of flavangenol. In this study, we investigated the antioxidant effects of flavangenol on reactive oxygen species such as hydroxyl radical, superoxide anion and singlet oxygen using electron spin resonance and spin trapping. The effect of flavangenol on oxidative stress in the skin from the maxillofacial region of hairless mice was investigated using an in vivo L-band electron spin resonance imaging system. Flavangenol attenuated oxidative stress in the maxillofacial skin by acting as a reactive oxygen species scavenger, as demonstrated by in vitro and in vivo electron spin resonance imaging analysis. The absorption and metabolism of flavangenol were also examined. After oral administration of flavangenol in human and rat, most of the catechin in plasma was in the conjugated form, while 45% to 78% of procyanidin B1 was unconjugated, indicating that non-conjugated procyanidin B1 would be active in the circulation. The ability of flavangenol to reduce reactive oxygen species levels in the circulation of the maxillofacial region suggests that this extract may be beneficial for skin protection from exposure to ultraviolet irradiation.

Yoshida, Ayaka; Yoshino, Fumihiko; Tsubata, Masahito; Ikeguchi, Motoya; Nakamura, Takeshi; Lee, Masaichi-Chang-il

2011-01-01

60

Direct assessment by electron spin resonance spectroscopy of the antioxidant effects of French maritime pine bark extract in the maxillofacial region of hairless mice.  

PubMed

Flavangenol, one of extract of French maritime pine bark, is a complex mixture of bioflavonoids with oligometric proanthocyanidins as the major constituents. These constituents, catechin and procyanidin B(1), are water-soluble derivatives of flavangenol. In this study, we investigated the antioxidant effects of flavangenol on reactive oxygen species such as hydroxyl radical, superoxide anion and singlet oxygen using electron spin resonance and spin trapping. The effect of flavangenol on oxidative stress in the skin from the maxillofacial region of hairless mice was investigated using an in vivo L-band electron spin resonance imaging system. Flavangenol attenuated oxidative stress in the maxillofacial skin by acting as a reactive oxygen species scavenger, as demonstrated by in vitro and in vivo electron spin resonance imaging analysis. The absorption and metabolism of flavangenol were also examined. After oral administration of flavangenol in human and rat, most of the catechin in plasma was in the conjugated form, while 45% to 78% of procyanidin B(1) was unconjugated, indicating that non-conjugated procyanidin B(1) would be active in the circulation. The ability of flavangenol to reduce reactive oxygen species levels in the circulation of the maxillofacial region suggests that this extract may be beneficial for skin protection from exposure to ultraviolet irradiation. PMID:21980222

Yoshida, Ayaka; Yoshino, Fumihiko; Tsubata, Masahito; Ikeguchi, Motoya; Nakamura, Takeshi; Lee, Masaichi-Chang-Il

2011-09-01

61

A study of coal extraction with electron paramagnetic resonance (EPR) and proton nuclear magnetic resonance relaxation techniques. Quarterly technical progress report, April 1, 1993--June 30, 1993  

SciTech Connect

An electron spin and proton magnetic relaxation study is presented on the effects of the solvent extraction of coal on the macromoleculer network of the coal and on the mobile molecular species that are initially within the coal. The eight Argonne Premium coals were extracted at room temperature with a 1:1 (v/v) N-methylpyrrolidinone (NMP)-CS2 solvent mixture under an inert atmosphere. As much solvent as possible was removed from extract and residue by treatment in a vacuum. The mobilization of molecular free radicals by the solvent and the exposure of free radicals in the macromoleculer matrix to solvent or to species dissolved in the solvent, results in a preferential survival of residue radicals of types that depend on the particular coal and results in the apparently fairly uniform loss of all types of radicals in bituminous coal extracts. The surviving extract and residue free radicals are more predominantly of the odd- alternate hydrocarbon free radical type. The spin-lattice relaxation (SLR) of these coal free radicals has previously been inferred (Doetschman and Dwyer, Energy Fuels, 1992, 6, 783) to be from the modulation of the intramolecular electron-nuclear dipole-interactions of the CH groups in a magnetic field by rocldng motions of the radical in the coal matrix. Such a modulation would depend not only on the rocking amplitude and frequency but also upon the electron spin density at the CH groups in the radical. The observed SLR rates decrease with coal rank in agreement with the smaller spin densities and the lower rocidng amplitudes that are expected for the larger polycondensed ring systems in coals of higher rank. The SLR rates are found to be generally faster in the extracts (than residues) where the molecular species would be expected to have a smaller polycondensed ring system than in the macromoleculer matrix of the residue.

Doetschman, D.C.; Mehlenbacher, R.C. [State Univ. of New York, Binghamton, NY (United States). Dept. of Chemistry; Ito, O. [Tohoku Univ., Sendai (Japan). Inst. for Chemical Reaction science

1993-09-01

62

Design and Measurement of a Digital Phase Locked BWO for Accurately Extracting the Quality Factors in a Biconcave Resonator System  

NASA Astrophysics Data System (ADS)

A long loop phase locked backward-wave oscillator (BWO) for a high quality factor resonator system operating at D-band frequencies (130-170GHz) was described, the phase noise of the phased locked BWO was analyzed and measured at typical frequencies. When it used with a high quality factor open resonator for measuring the quality factor of simple harmonic resonators based on the magnitude transfer characteristic, this system has proven to be capable of accurate measuring the quality factor as high as 0.8 million with an uncertainty of less than 1.3% (Lorentzian fitting) at typical frequencies in the range of 130GHz-170GHz.

Gao, Yuanci; Charles, Jones R.; Yu, Guofen; Jyotsna, Dutta M.

2012-03-01

63

Multi-physics power-drive-level dependant equivalent circuit models extraction for electro-mechanical resonators  

Microsoft Academic Search

This paper discusses multi -physics modeling methodology for the design and analysis of integrated crystal oscillators based on power-waves formulation. Conventional Barkhausen oscillation conditions criterion is derived in terms of reflection coefficients. Necessity of power-drive-level dependant equivalent circuit models derivation for electromechanical resonators is investigated in order to build bridging connections between more than one energy domain (mechanical, electrical, acoustics,

Sidina Wane; Damienne Bajon

2011-01-01

64

Experimental investigation of a control scheme for a zero-detuning resonant sideband extraction interferometer for next-generation gravitational-wave detectors  

NASA Astrophysics Data System (ADS)

Some next-generation gravitational-wave detectors, such as the American Advanced LIGO project and the Japanese LCGT project, plan to use power recycled resonant sideband extraction (RSE) interferometers for their interferometer's optical configuration. A power recycled zero-detuning (PRZD) RSE interferometer, which is the default design for LCGT, has five main length degrees of freedom that need to be controlled in order to operate a gravitational-wave detector. This task is expected to be very challenging because of the complexity of optical configuration. A new control scheme for a PRZD RSE interferometer has been developed and tested with a prototype interferometer. The PRZD RSE interferometer was successfully locked with the control scheme. It is the first experimental demonstration of a PRZD RSE interferometer with suspended test masses. The result serves as an important step for the operation of LCGT.

Kawazoe, Fumiko; Sugamoto, Akio; Leonhardt, Volker; Sato, Shuichi; Yamazaki, Toshitaka; Fukushima, Mitsuhiro; Kawamura, Seiji; Miyakawa, Osamu; Somiya, Kentaro; Morioka, Tomoko; Nishizawa, Atsushi

2008-10-01

65

Application of high performance liquid chromatography coupled to on-line solid-phase extraction-nuclear magnetic resonance spectroscopy for the analysis of degradation products of V-class nerve agents and nitrogen mustard  

Microsoft Academic Search

The detection and identification of the degradation products of nitrogen mustard and nerve agent VX by high performance liquid chromatography coupled to on-line solid-phase extraction-nuclear magnetic resonance spectroscopy (HPLC-UV-SPE-NMR) were demonstrated. The analytes selected for the study were N,N-dimethylaminoethanol (DMAE), N,N-diethylaminoethanol (DEAE), N,N-diisopropylaminoethanol (DIAE) and triethanolamine (TEA). Offline solid-phase extraction (SPE) followed by derivatization was applied to eliminate the interferents

Avik Mazumder; Ajeet Kumar; Ajay K. Purohit; Devendra K. Dubey

2010-01-01

66

Comparison of analytical and semi-preparative columns for high-performance liquid chromatography-solid-phase extraction-nuclear magnetic resonance.  

PubMed

The application of analytical and semi-preparative columns in reversed-phase liquid chromatography-solid-phase extraction-nuclear magnetic resonance (HPLC-SPE-NMR) was compared. The work was aiming at separating a higher sample amount in a single run and in this way to reduce the necessary NMR measurement time of separated compounds. Several parameters for compound separation and trapping procedures were optimised: flow rate of HPLC and make-up water pumps, choice of stationary phase cartridges and drying time. The separation and loadability of nine model compounds on analytical and semi-preparative columns was determined, as well as the focussing capacity of SH-type SPE cartridges. It was found that a semi-preparative column--or multiple peak trapping on analytical columns--gave better results than a standard 4.6mm analytical column for non-polar compounds (e.g. flavonoid aglycones, sesquiterpene lactones, non-polar terpenes, logP>2), but for polar compounds (logP<-2) did not offer any advantage over an analytical column, or was even disadvantageous. For intermediately polar compounds (-2

Miliauskas, Giedrius; van Beek, Teris A; de Waard, Pieter; Venskutonis, Rimantas P; Sudhölter, Ernst J R

2006-04-21

67

Classification of magnetic resonance images  

Microsoft Academic Search

The aim of the paper is to compare classification error of the classifiers applied to magnetic resonance images for each descriptor used for feature extraction. We compared several Support Vector Machine (SVM) techniques, neural networks and k nearest neighbor classifier for classification of Magnetic Resonance Images (MRIs). Different descriptors are applied to provide feature extraction from the images. The dataset

Katarina Trojacanec; Gjorgji Madzarov; Dejan Gjorgjevikj; Suzana Loskovska

2010-01-01

68

Cavity Resonators.  

National Technical Information Service (NTIS)

The microwave cavity resonator may be used in the field of electron spin resonance spectroscopy for studying samples of paramagnetic materials which are supported within the resonator. The resonator passes a maximum amount of light through the walls to th...

E. L. Cochran

1965-01-01

69

Targeting high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance analysis with high-resolution radical scavenging profiles-Bioactive secondary metabolites from the endophytic fungus Penicillium namyslowskii.  

PubMed

The high-resolution radical scavenging profile of an extract of the endophytic fungus Penicillium namyslowskii was used to target analysis by high-performance liquid chromatography-high-resolution mass spectrometry-solid-phase extraction-nuclear magnetic resonance spectroscopy, i.e., HPLC-HRMS-SPE-NMR, for identification of anti-oxidative secondary metabolites. This revealed the two chromatographic peaks with the highest relative response in the radical scavenging profile to be griseophenone C and peniprequinolone. The HPLC-HRMS-SPE-NMR analysis was performed in the tube-transfer mode using a cryogenically cooled NMR probe designed for 1.7mm NMR tubes. To further explore the potential of the above HPLC-HRMS-SPE-NMR platform for analysis of endophytic extracts, six peaks displaying no radical scavenging activity were also analyzed. This allowed unambiguous identification of six metabolites, i.e., dechlorogriseofulvin, dechlorodehydrogriseofulvin, griseofulvin, dehydrogriseofulvin, mevastatin acid, and mevastatin. The high mass sensitivity of the 1.7mm cryogenically cooled NMR probe allowed for the first time acquisition of direct detected (13)C NMR spectra of fungal metabolites, i.e., dechlorogriseofulvin and griseofulvin, directly from crude extract via HPLC-HRMS-SPE-NMR. Dechlorodehydrogriseofulvin was reported for the first time from nature. PMID:23827469

Wubshet, Sileshi G; Nyberg, Nils T; Tejesvi, Mysore V; Pirttilä, Anna Maria; Kajula, Marena; Mattila, Sampo; Staerk, Dan

2013-08-01

70

Stochastic Resonance  

NASA Astrophysics Data System (ADS)

Preface; 1. Introduction and motivation; 2. Stochastic resonance: its definitions, history and debates; 3. Stochastic quantization; 4. Suprathreshold stochastic resonance: encoding; 5. Suprathreshold stochastic resonance: large N encoding; 6. Suprathreshold stochastic resonance: decoding; 7. Suprathreshold stochastic resonance: large N decoding; 8. Optimal stochastic quantization; 9. SSR, neural coding, and performance tradeoffs; 10. Stochastic resonance in the auditory system; 11. The future of stochastic resonance and suprathreshold stochastic resonance; Appendices; References; Index.

McDonnell, Mark D.; Stocks, Nigel G.; Pearce, Charles E. M.; Abbott, Derek

2012-10-01

71

Identification of degradation products in loxoprofen sodium adhesive tapes by liquid chromatography–mass spectrometry and dynamic pressurized liquid extraction–solid-phase extraction coupled to liquid chromatography–nuclear magnetic resonance spectroscopy  

Microsoft Academic Search

Rapid and unambiguous identification of three degradation products (DP-1, DP-2 and DP-3) found in heat-stressed loxoprofen sodium adhesive tapes (Loxonin tapes) was achieved by LC–MS and dynamic pressurized liquid extraction (PLE)–solid-phase extraction (SPE) coupled to LC–NMR without complicated isolation or purification processes. The molecular formulae of the degradation products were determined by accurate mass measurements and product ion analyses and

Tomonori Murakami; Takao Kawasaki; Akira Takemura; Naoto Fukutsu; Naoyuki Kishi; Fumiyo Kusu

2008-01-01

72

A study on prevention of an electric discharge at an extraction electrode of an electron cyclotron resonance ion source for cancer therapy.  

PubMed

A compact ECR ion source has utilized for carbon radiotherapy. In order to increase beam intensity with higher electric field at the extraction electrode and be better ion supply stability for long periods, electric geometry and surface conditions of an extraction electrode have been studied. Focusing attention on black deposited substances on the extraction electrode, which were observed around the extraction electrode after long-term use, the relation between black deposited substances and the electrical insulation property is investigated. The black deposited substances were inspected for the thickness of deposit, surface roughness, structural arrangement examined using Raman spectroscopy, and characteristics of electric discharge in a test bench, which was set up to simulate the ECR ion source. PMID:24593429

Kishii, Y; Kawasaki, S; Kitagawa, A; Muramatsu, M; Uchida, T

2014-02-01

73

Metabolomics of transgenic maize combining Fourier transform-ion cyclotron resonance-mass spectrometry, capillary electrophoresis-mass spectrometry and pressurized liquid extraction  

Microsoft Academic Search

In this work, the potential of combining capillary electrophoresis-time-of-flight-mass spectrometry (CE-TOF-MS) and Fourier transform-ion cyclotron resonance-mass spectrometry (FT-ICR-MS) for metabolomics of genetically modified organisms (GMOs) is demonstrated. Thus, six different varieties of maize, three of them transgenic (PR33P66 Bt, Tietar Bt and Aristis Bt) and their corresponding isogenic lines (PR33P66, Tietar and Aristis) grown under the same field conditions, were

Carlos Leon; Irene Rodriguez-Meizoso; Marianna Lucio; Virginia Garcia-Cañas; Elena Ibañez; Philippe Schmitt-Kopplin; Alejandro Cifuentes

2009-01-01

74

Nuclear magnetic resonance and liquid chromatography-mass spectrometry combined with an incompleted separation strategy for identifying the natural products in crude extract.  

PubMed

NMR and LC-MS combined with an incompleted separation strategy were proposed to the simultaneous structure identification of natural products in crude extracts, and a novel method termed as NMR/LC-MS parallel dynamic spectroscopy (NMR/LC-MS PDS) was developed to discover the intrinsic correlation between retention time (Rt), mass/charge (m/z) and chemical shift (delta) data of the same constituent from mixture spectra by the co-analysis of parallelly visualized multispectroscopic datasets from LC-MS and (1)H NMR. The extracted ion chromatogram (XIC) and (1)H NMR signals deriving from the same individual constituent were correlated through fraction ranges and intensity changing profiles in NMR/LC-MS PDS spectrum due to the signal amplitude co-variation resulted from the concentration variation of constituents in a series of incompletely separated fractions. NMR/LC-MS PDS was applied to identify 12 constituents in an active herbal extract including flavonol glycosides, which was separated into a series of fractions by flash column chromatography. The complementary spectral information of the same individual constituent in the crude extract was discovered simultaneously from mixture spectra. Especially, two groups of co-eluted isomers were identified successfully. The results demonstrated that NMR/LC-MS PDS combined with the incompleted separation strategy achieved the similar function of on-line LC-NMR-MS analysis in off-line mode and had the potential for simplifying and accelerating the analytical routes for structure identification of constituents in herbs or their active extracts. PMID:19110097

Dai, Dongmei; He, Jiuming; Sun, Ruixiang; Zhang, Ruiping; Aisa, Haji Akber; Abliz, Zeper

2009-01-26

75

Nuclear magnetic resonance and liquid chromatography–mass spectrometry combined with an incompleted separation strategy for identifying the natural products in crude extract  

Microsoft Academic Search

NMR and LC–MS combined with an incompleted separation strategy were proposed to the simultaneous structure identification of natural products in crude extracts, and a novel method termed as NMR\\/LC–MS parallel dynamic spectroscopy (NMR\\/LC–MS PDS) was developed to discover the intrinsic correlation between retention time (Rt), mass\\/charge (m\\/z) and chemical shift (?) data of the same constituent from mixture spectra by

Dongmei Dai; Jiuming He; Ruixiang Sun; Ruiping Zhang; Haji Akber Aisa; Zeper Abliz

2009-01-01

76

Application of high performance liquid chromatography coupled to on-line solid-phase extraction-nuclear magnetic resonance spectroscopy for the analysis of degradation products of V-class nerve agents and nitrogen mustard.  

PubMed

The detection and identification of the degradation products of nitrogen mustard and nerve agent VX by high performance liquid chromatography coupled to on-line solid-phase extraction-nuclear magnetic resonance spectroscopy (HPLC-UV-SPE-NMR) were demonstrated. The analytes selected for the study were N,N-dimethylaminoethanol (DMAE), N,N-diethylaminoethanol (DEAE), N,N-diisopropylaminoethanol (DIAE) and triethanolamine (TEA). Offline solid-phase extraction (SPE) followed by derivatization was applied to eliminate the interferents and make the analytes amenable for UV detection. Thereafter, chromatographically separated derivatives were trapped on on-line SPE cartridges. They were subsequently eluted and 1H NMR and COSY spectra were obtained. The overall detection limits of the LC-UV-SPE-NMR method for the mentioned analytes were found to be 18, 23, 25, and 32 mg/L respectively. Applicability of the method to real samples was demonstrated by the analysis of samples provided during the 22nd OPCW official proficiency test. The method gave reproducible NMR spectra devoid of intense background signals. PMID:20303089

Mazumder, Avik; Kumar, Ajeet; Purohit, Ajay K; Dubey, Devendra K

2010-04-23

77

A comparative study of feature extraction and blind source separation of independent component analysis (ICA) on childhood brain tumour 1H magnetic resonance spectra.  

PubMed

Independent component analysis (ICA) has the potential of determining automatically the metabolite signals which make up MR spectra. However, the reliability with which this is accomplished and the optimal approach for investigating in vivo MRS have not been determined. Furthermore, the properties of ICA in brain tumour MRS with respect to dataset size and data quality have not been systematically explored. The two common techniques for applying ICA, blind source separation (BSS) and feature extraction (FE) were examined in this study using simulated data and the findings confirmed on patient data. Short echo time (TE 30 ms), low and high field (1.5 and 3 T) in vivo brain tumour MR spectra of childhood astrocytoma, ependymoma and medulloblastoma were generated by using a quantum mechanical simulator with ten metabolite and lipid components. Patient data (TE 30 ms, 1.5 T) were acquired from children with brain tumours. ICA of simulated data shows that individual metabolite components can be extracted from a set of MRS data. The BSS method generates independent components with a closer correlation to the original metabolite and lipid components than the FE method when the number of spectra in the dataset is small. The experiments also show that stable results are achieved with 300 MRS at an SNR equal to 10. The FE method is relatively insensitive to different ranges of full width at half maximum (FWHM) (from 0 to 3 Hz), whereas the BSS method degrades on increasing the range of FWHM. The peak frequency variations do not affect the results within the range of +/-0.08 ppm for the FE method, and +/-0.05 ppm for the BSS method. When the methods were applied to the patient dataset, results consistent with the synthesized experiments were obtained. PMID:19431141

Hao, Jie; Zou, Xin; Wilson, Martin P; Davies, Nigel P; Sun, Yu; Peet, Andrew C; Arvanitis, Theodoros N

2009-10-01

78

Detection of oligonucleotide hybridization at femtomolar level and sequence-specific gene analysis of the Arabidopsis thaliana leaf extract with an ultrasensitive surface plasmon resonance spectrometer.  

PubMed

A flow-injection (FI) device is combined, through the use of a low-volume (4 microl) flow cell, with an ultrasensitive surface plasmon resonance (SPR) spectrometer equipped with a bi-cell photodiode detector. The application of this novel FI-SPR device for sequence-specific ultratrace analysis of oligodeoxynucleotides (ODNs) and polydeoxynucleotides was demonstrated. Self-assembled monolayers of ODN probes are tethered onto Au films with a mercaptohexyl group at the 3' ends. The FI-SPR provides a detection level (< or =54 fM) 2-3 orders of magnitude lower than other SPR devices and compares well with several ultrasensitive detection methods for labeled DNA targets (e.g. fluorophore-tagged and radiolabeled DNA samples). The technique is also highly selective, since a 47mer ODN target with a single-base mismatch yielded a much smaller SPR signal, and a specific interaction was detected when the complementary target was present at 0.001% of the total DNA. The FI-SPR was extended to the measurement of two individual genes in a cDNA mixture transcribed from an Arabidopsis thaliana leaf mRNA pool. The greatly enhanced sensitivity not only obviates the necessity of DNA labeling, but also significantly reduces sample consumption, allowing direct quantification of low abundance mRNAs in cellular samples without amplification. PMID:12136120

Song, Fayi; Zhou, Feimeng; Wang, Jun; Tao, Nongjian; Lin, Jianqiao; Vellanoweth, Robert L; Morquecho, Yvonne; Wheeler-Laidman, Janel

2002-07-15

79

Optical resonator  

NASA Technical Reports Server (NTRS)

The invention discloses a semi-ring Fabry-Perot (SRFP) optical resonator structure comprising a medium including an edge forming a reflective facet and a waveguide within the medium, the waveguide having opposing ends formed by the reflective facet. The performance of the SRFP resonator can be further enhanced by including a Mach-Zehnder interferometer in the waveguide on one side of the gain medium. The optical resonator can be employed in a variety of optical devices. Laser structures using at least one SRFP resonator are disclosed where the resonators are disposed on opposite sides of a gain medium. Other laser structures employing one or more resonators on one side of a gain region are also disclosed.

Taghavi-Larigani, Shervin (Inventor); Vanzyl, Jakob J. (Inventor); Yariv, Amnon (Inventor)

2006-01-01

80

Padé approximants and resonance poles  

NASA Astrophysics Data System (ADS)

Based on the mathematically well defined Padé theory, a theoretically safe new procedure for the extraction of the pole mass and width of a resonance is proposed. In particular, thanks to the Montessus de Ballore theorem we are able to unfold the second Riemann sheet of an amplitude to search for the position of the resonance pole in the complex plane. The method is systematic and provides a model-independent treatment of the prediction and the corresponding errors of the approximation. Likewise, it can be used in combination with other well-established approaches to improve future determinations of resonance parameters.

Masjuan, Pere; Sanz-Cillero, Juan José

2013-10-01

81

Fluorescence resonance energy transfer-based real-time polymerase chain reaction method without DNA extraction for the genotyping of F5, F2, F12, MTHFR, and HFE  

PubMed Central

Blood samples are extensively used for the molecular diagnosis of many hematological diseases. The daily practice in a clinical laboratory of molecular diagnosis in hematology involves using a variety of techniques, based on the amplification of nucleic acids. Current methods for polymerase chain reaction (PCR) use purified genomic DNA, mostly isolated from total peripheral blood cells or white blood cells (WBC). In this paper we describe a real-time fluorescence resonance energy transfer-based method for genotyping directly from blood cells. Our strategy is based on an initial isolation of the WBCs, allowing the removal of PCR inhibitors, such as the heme group, present in the erythrocytes. Once the erythrocytes have been lysed, in the LightCycler® 2.0 Instrument, we perform a real-time PCR followed by a melting curve analysis for different genes (Factors 2, 5, 12, MTHFR, and HFE). After testing 34 samples comparing the real-time crossing point (CP) values between WBC (5×106 WBC/mL) and purified DNA (20 ng/?L), the results for F5 Leiden were as follows: CP mean value for WBC was 29.26±0.566 versus purified DNA 24.79±0.56. Thus, when PCR was performed from WBC (5×106 WBC/mL) instead of DNA (20 ng/?L), we observed a delay of about 4 cycles. These small differences in CP values were similar for all genes tested and did not significantly affect the subsequent analysis by melting curves. In both cases the fluorescence values were high enough, allowing a robust genotyping of all these genes without a previous DNA purification/extraction.

Martinez-Serra, Jordi; Robles, Juan; Nicolas, Antoni; Gutierrez, Antonio; Ros, Teresa; Amat, Juan Carlos; Alemany, Regina; Vogler, Oliver; Abello, Aina; Noguera, Aina; Besalduch, Joan

2014-01-01

82

Couplings of asynchronously tuned coupled microwave resonators  

Microsoft Academic Search

The papcr presents a comprehensive treatment of the couplings of asynchronously tuned coupled microwave resonators. The derived formulation allows one to extract coupling coefficients in terms of four characteristic frequencies that can be easily dctermined numerically or experiincntally. To demonstrate the applications, numerical examples are given for asynchronously tuned microstrip coupled open-loop and dual-mode resonators.

J.-S. Hong

2000-01-01

83

Electromagnetic excitation of nucleon resonances  

SciTech Connect

Theoretical approaches for extracting the {gamma} N {l_arrow} {r_arrow} {sup *} matrix elements from the data of {gamma} N {r_arrow} {pi} N and N(e,e {prime} {pi}) reactions are reviewed. We discuss the physical content of the {Delta} resonance parameters listed in the table of particle properties.

Lee, T.S.H.

1992-09-01

84

Electromagnetic excitation of nucleon resonances  

SciTech Connect

Theoretical approaches for extracting the {gamma} N {l arrow} {r arrow} {sup *} matrix elements from the data of {gamma} N {r arrow} {pi} N and N(e,e {prime} {pi}) reactions are reviewed. We discuss the physical content of the {Delta} resonance parameters listed in the table of particle properties.

Lee, T.S.H.

1992-01-01

85

Beam transfer and extraction at LAMPF II  

SciTech Connect

Protons will be single-turn extracted from the LAMPF II synchrotron at 30 Hz. On alternate pulses they will be single-turn injected into a storage ring. Both processes utilize fast kickers and Lambertson septum magnets. Half-integer resonant extraction will be used to slow-extract the beam from the storage ring over a time spread of 1/15 s. The slow extraction occurs using electrostatic wire and iron septa.

Colton, E.P.

1983-01-01

86

Extraction of soil organic phosphorus.  

PubMed

Organic phosphorus is an important component of soil biogeochemical cycles, but must be extracted from soil prior to analysis. Here we critically review the extraction of soil organic phosphorus, including procedures for quantification, speciation, and assessment of biological availability. Quantitative extraction conventionally requires strong acids and bases, which inevitably alter chemical structure. However, a single-step procedure involving sodium hydroxide and EDTA (ethylenediaminetetraacetate) is suitable for most soils and facilitates subsequent speciation by nuclear magnetic resonance spectroscopy. Analysis of extracts by molybdate colorimetry is a potential source of error in all procedures, because organic phosphorus is overestimated in the presence of inorganic polyphosphates or complexes between inorganic phosphate and humic substances. Sequential extraction schemes fractionate organic phosphorus based on chemical solubility, but the link to potential bioavailability is misleading. Research should be directed urgently towards establishing extractable pools of soil organic phosphorus with ecological relevance. PMID:18969994

Turner, Benjamin L; Cade-Menun, Barbara J; Condron, Leo M; Newman, Susan

2005-04-15

87

Laser Resonator  

NASA Technical Reports Server (NTRS)

An optical resonator cavity configuration has a unitary mirror with oppositely directed convex and concave reflective surfaces disposed into one fold and concertedly reversing both ends of a beam propagating from a laser rod disposed between two total internal reflection prisms. The optical components are rigidly positioned with perpendicularly crossed virtual rooflines by a compact optical bed. The rooflines of the internal reflection prisms, are arranged perpendicularly to the axis of the laser beam and to the optical axes of the optical resonator components.

Harper, L. L. (inventor)

1983-01-01

88

Differential cross section and polarization extractions for gamma p going to K+sigma0 and gamma p going to phi p using CLAS at Jefferson Lab, towards a partial wave analysis in search of missing baryon resonances  

NASA Astrophysics Data System (ADS)

In the first part of this work, we present differential cross section and polarization measurements for the reactions gammap ? K+Sigma0 and gammap ? ?p. The data were collected using the large-acceptance CLAS detector stationed in Ball B at Jefferson Lab. An unpolarized energy-tagged photon beam produced via bremsstrahlung and a liquid hydrogen cryotarget was used for this, during the so-called g11a experimental run-period. The kinematic coverage of our results is from near production threshold to s = 2.84 GeV in energy and -0.95 ? costhetac.m. ? +0.95 in the meson production angle thetac.m.. For the most part, our results are finely binned in 10-MeV-wide s bins. For the ?p channel, we analyze both the charged (? ? K+K -) and the neutral (? ? K0SK0L ) decay modes. For K+Sigma 0, our work corresponds to a 300 MeV increase in energy coverage for the differential cross sections and forms the first extensive recoil polarization world dataset. For ?p, where previous world data is either non-existent or exist with wide energy bins and very limited statistics, our results will be the first extensive world dataset for both the cross sections and the spin density matrix elements r0MM' . Our K+Sigma0 results are now published as PRC 82, 025202 (2010) [1] and the ?p results are also nearing completion of internal Collaboration analysis review. In addition, we have also been able to extend upon a previous K+? analysis in the backward-angles and near-threshold kinematic regimes, using a higher statistics dataset. The second segment consists of setting up a general framework for performing a coupled-channel partial wave analysis (PWA) on these extracted data results. Our final goal is to search for the so-called "missing" baryon resonances, that is, states predicted by quark models, but absent in conventional piN analyses. We construct the amplitudes and polarization observables required for this PWA. For polarizations in the pseudo-scalar sector, sign discrepancies due to different conventions adopted by different authors in the field are treated in a systematic manner and this study has been published as PRC 83, 055208 (2011) [2]. During our preliminary PWA, we found that certain normalization discrepancies exist between CLAS and older higher energy data from SLAC/DESY/CEA. A systematic global study of these normalization issues and their effect on the coupling constants in hadrodynamic model is presented. Our PWA is an ongoing work and the rich set of data results and analysis tools obtained here will provide a strong impetus for continuing investigations.

Dey, Biplab

89

Resonant Tunneling Spin Pump  

NASA Technical Reports Server (NTRS)

The resonant tunneling spin pump is a proposed semiconductor device that would generate spin-polarized electron currents. The resonant tunneling spin pump would be a purely electrical device in the sense that it would not contain any magnetic material and would not rely on an applied magnetic field. Also, unlike prior sources of spin-polarized electron currents, the proposed device would not depend on a source of circularly polarized light. The proposed semiconductor electron-spin filters would exploit the Rashba effect, which can induce energy splitting in what would otherwise be degenerate quantum states, caused by a spin-orbit interaction in conjunction with a structural-inversion asymmetry in the presence of interfacial electric fields in a semiconductor heterostructure. The magnitude of the energy split is proportional to the electron wave number. Theoretical studies have suggested the possibility of devices in which electron energy states would be split by the Rashba effect and spin-polarized currents would be extracted by resonant quantum-mechanical tunneling.

Ting, David Z.

2007-01-01

90

Spurious Resonances and Modelling of Composite Resonators.  

National Technical Information Service (NTIS)

Several three-dimensional models have been developed for explaining the characteristics of composite resonators. The agreement between the resonance spectra predicted by the models and the experimental data is excellent, including spurious resonance frequ...

K. B. Yoo H. Ueberall D. Ashrafi S. Ashrafi

1983-01-01

91

Negative effective gravity in water waves by periodic resonator arrays.  

PubMed

Based on analytic derivations and numerical simulations, we show that near a low resonant frequency water waves cannot propagate through a periodic array of resonators (bottom-mounted split tubes) as if water has a negative effective gravitational acceleration g(e) and positive effective depth h(e). This gives rise to a low-frequency resonant band gap in which water waves can be strongly reflected by the resonator array. For a damping resonator array, the resonant gap can also dramatically modify the absorption efficiency of water waves. The results provide a mechanism to block water waves and should find applications in ocean wave energy extraction. PMID:21635037

Hu, Xinhua; Chan, C T; Ho, Kai-Ming; Zi, Jian

2011-04-29

92

Resonant behavior of dielectric objects (electrostatic resonances).  

PubMed

Resonant behavior of dielectric objects occurs at certain frequencies for which the object permittivity is negative and the free-space wavelength is large in comparison with the object dimensions. Unique physical features of these resonances are studied and a novel technique for the calculation of resonance values of permittivity, and hence resonance frequencies, is proposed. Scale invariance of resonance frequencies, unusually strong orthogonality properties of resonance modes, and a two-dimensional phenomenon of "twin" spectra are reported. The paper concludes with brief discussions of optical controllability of these resonances in semiconductor nanoparticles and a plausible, electrostatic resonance based, mechanism for nucleation and formation of ball lightning. PMID:14754117

Fredkin, D R; Mayergoyz, I D

2003-12-19

93

Experimental properties of an unstable resonator with nonuniform magnification using aspheric mirrors  

Microsoft Academic Search

Laser resonators having nonuniform magnification can provide an advantage over constant magnification resonators in terms of energy extraction and far-field performance for low-gain lasers. This work explored the experimental characteristics of a resonator that was designed to have a lower magnification at the center of the resonator than at the edge. This was achieved using aspheric mirrors. Misalignment sensitivity, intracavity

Margaret A. Malloy; Christopher M. Clayton

1988-01-01

94

Combination of matrix solid-phase dispersion extraction and direct on-line liquid chromatography–nuclear magnetic resonance spectroscopy–tandem mass spectrometry as a new efficient approach for the rapid screening of natural products  

Microsoft Academic Search

A combination of matrix solid-phase dispersion extraction (MSPD) and LC–NMR–MS hyphenation is proposed as a rapid screening method of natural products for unknown compounds. In this report, this new analytical approach is applied for the first time. MSPD represents a significant simplification compared to classical extraction procedures and is thus an excellent complement to the fast and powerful LC–NMR–MS: MSPD

Martin Sandvoss; Anja Weltring; Alfred Preiss; Karsten Levsen; Gerold Wuensch

2001-01-01

95

All-resonant control of superconducting resonators.  

PubMed

An all-resonant method is proposed to control the quantum state of superconducting resonators. This approach uses a tunable artificial atom linearly coupled to resonators, and allows for efficient routes to Fock state synthesis, qudit logic operations, and synthesis of NOON states. This resonant approach is theoretically analyzed, and found to perform significantly better than existing proposals using the same technology. PMID:23215585

Strauch, Frederick W

2012-11-21

96

Resonance Rings  

NSDL National Science Digital Library

This is an activity about resonance and where it is found in related to astronomy. Learners will construct two differently sized rings out of file folder paper and tape them to a piece of cardboard. Next, they will shake the cardboard from side to side, which shakes the rings, and observe what happens when the frequency of the shaking is gradually increased. This activity is from the Stanford Solar Center's All About the Sun: Sun and Stars activity guide for Grades 5-8 and can also accompany the Stanford Solar Center's Build Your Own Spectroscope activity.

97

Contour extraction from cardiac MRI studies using snakes  

Microsoft Academic Search

The author investigated automatic extraction of left ventricular contours from cardiac magnetic resonance imaging (MRI) studies. The contour extraction algorithms were based on active contour models, or snakes. Based on cardiac MR image characteristics, the author suggested algorithms for extracting contours from these large data sets. The author specifically considered contour propagation methods to make the contours reliable enough despite

Surendra Ranganath

1995-01-01

98

Resonances from AMPT  

NASA Astrophysics Data System (ADS)

A multiphase transport (AMPT) model that includes both initial partonic and final hadron rescattering effects in relativistic heavy ion collisions is briefly reviewed. Particular attention is given to the scattering processes in the hadronic phase in order to address resonances production in these collisions. As an example, phi meson production is discussed in detail through both its dikaon and dilepton decay channels. Results from the AMPT model for heavy ion collisions at both SPS and RHIC are compared to the experimental data to extract information on the production mechanism and in-medium properties of the phi meson. Supported by the U.S. National Science Foundation under Grant No. PHY-1068572, the US Department of Energy under Contract No. DE-FG02-10ER41682, and the Welch Foundation under Grant No. A-1358.

Ko, Che Ming

2012-11-01

99

Tooth Extraction  

MedlinePLUS

... the immune system. Wisdom teeth , also called third molars, are often extracted either before or after they ... sinus during removal of an upper back tooth (molar) — A small hole usually will close up by ...

100

DNA Extraction  

NSDL National Science Digital Library

In this activity related to plant biotechnology, learners extract DNA from fruit to investigate how it looks and feels. The procedure is similar to what scientists have to do before they can use information contained in this DNA. This lesson guide includes procedure and discussion questions to help learners reflect on the process and purpose of DNA extraction. Modifications for younger learners are included in a related PDF (see related resources).

Stephens, Janice; Leach, Jan

2011-01-01

101

Bevalac extraction  

SciTech Connect

This report will describe some of the general features of the Bevatron extraction system, primarily the dependence of the beam parameters and extraction magnet currents on the Bevalac field. The extraction magnets considered are: PFW, XPl, XP2, XS1, XS2, XM1, XM2, XM3, XQ3A and X03B. This study is based on 84 past tunes (from 1987 to the present) of various ions (p,He,O,Ne,Si,S,Ar,Ca,Ti,Fe,Nb,La,Au and U), for Bevalac fields from 1.749 to 12.575 kG, where all tunes included a complete set of beam line wire chamber pictures. The circulating beam intensity inside the Bevalac is measured with Beam Induction Electrodes (BIE) in the South Tangent Tank. The extracted beam intensity is usually measured with the Secondary Emission Monitor (SEM) in the F1-Box. For most of the tunes the extraction efficiency, as given by the SEM/BIE ratio, was not recorded in the MCR Log Book, but plotting the available Log Book data as a function of the Bevalac field, see Fig.9, we find that the extraction efficiency is typically between 30->60% with feedback spill.

Kalnins, J.G.; Krebs, G.; Tekawa, M.; Cowles, D.; Byrne, T.

1992-02-01

102

Analysis of lasing in COILs with positive and negative branch unstable resonators using a simple geometrical-optics model  

NASA Astrophysics Data System (ADS)

A simple geometrical optics model is developed, describing the power extraction in chemical oxygen-iodine lasers with unstable resonators. The positive and negative branch unstable resonators with cylindrical mirrors that were recently used in the COIL are studied. The optical extraction efficiency and intensity spatial distributions in the flow direction for both kinds of resonators are calculated.

Barmashenko, Boris D.

2008-10-01

103

Measuring frequency response of surface-micromachined resonators  

NASA Astrophysics Data System (ADS)

Resonator structures offer a unique mechanism for characterizing MEMS materials, but measuring the resonant frequency of microstructures is challenging. In this effort a network analyzer system was used to electrically characterize surface-micromachined resonator structures in a carefully controlled pressure and temperature environment.A microscope laser interferometer was used to confirm actual device deflections.Cantilever, comb, and piston resonators fabricated in the DARPA-sponsored MUMPs process were extensively tested. Measured resonator frequency results show reasonable agreement with analytic predictions computed using manufacturer measured film thickness and residual material stress. Alternatively the measured resonant frequency data can be used to extract materials data. Tuning of resonant frequency with DC bias was also investigated. Because the tested devices vary widely in complexity, form a simple cantilever beam to a comb resonator, the data collected is especially well suited for validation testing of MEMS modeling codes.

Cowan, William D.; Bright, Victor M.; Dalton, George C.

1997-09-01

104

Coal extraction  

SciTech Connect

Coal is extracted using a mixed solvent which includes a substantially aromatic component and a substantially naphthenic component, at a temperature of 400/sup 0/ to 500/sup 0/C. Although neither component is an especially good solvent for coal by itself, the use of mixed solvent gives greater flexibility to the process and offers efficiency gains.

Clarke, J.W.; Kimber, G.M.; Rantell, T.D.; Snape, C.E.

1985-06-04

105

Extractable resources  

NASA Technical Reports Server (NTRS)

The use of information from space systems in the operation of extractive industries, particularly in exploration for mineral and fuel resources was reviewed. Conclusions and recommendations reported are based on the fundamental premise that survival of modern industrial society requires a continuing secure flow of resources for energy, construction and manufacturing, and for use as plant foods.

1975-01-01

106

extraction (SPE) ??????????? ????????????????????  

Microsoft Academic Search

????????? High performance liquid chromatography (HPLC) ??? % Recovery ????????????????? 29-100% ??????????????? Linear working range ?????????? 0.05-10.4 mg\\/L ????????? Correlation coefficient (r) ?????? 0.9962-0.9999 ????????????????? dimethylphosphate ???????????????????? liquid-liquid extraction ?????? Shaker ??? Centrifuge ?????????????????????????????? Gas liquid chromatography (GC) ??? Flame photometric detector (FPD) ??? % Recovery ????????????????? 26-114 % ??????????????? Linear working range ?????????? 0.02-7.74 mg\\/L ?????? Correlation coefficient (r)

Tawatchai Hongtrakul; Sakson Suwannabutra

107

Effective resonance levels  

Microsoft Academic Search

A method based on the use of effective resonance integrals or group cross sections with resonance self-shielding factors has come into extensive use in calculations of resonance absorption in homogeneous systems. An attempt is made to extend the subgroup treatment, which was initially formulated for the region of forbidden resonances, to the allowed region as applicable to heterogeneous media. A

B. P. Kochurov

1986-01-01

108

Texture Coding in the Rat Whisker System: Slip-Stick Versus Differential Resonance  

Microsoft Academic Search

Rats discriminate surface textures using their whiskers (vibrissae), but how whiskers extract texture information, and how this information is encoded by the brain, are not known. In the resonance model, whisker motion across different textures excites mechanical resonance in distinct subsets of whiskers, due to variation across whiskers in resonance frequency, which varies with whisker length. Texture information is therefore

Jason Wolfe; Dan N Hill; Sohrab Pahlavan; Patrick J Drew; David Kleinfeld; Daniel E Feldman

2008-01-01

109

Resonant cortical dynamics of speech perception  

NASA Astrophysics Data System (ADS)

What is the neural representation of a speech code as it evolves in time? How do listeners integrate temporally distributed phonemic information into coherent representations of syllables and words? How does the brain extract invariant properties of variable-rate speech? This talk describes a neural model that suggests answers to these questions, while quantitatively simulating speech and word recognition data. The conscious speech and word recognition code is suggested to be a resonant wave, and a percept of silence a temporal discontinuity in the rate that resonance evolves. A resonant wave emerges when sequential activation and storage of phonemic items in working memory provides bottom-up input to list chunks that group together sequences of items of variable length. The list chunks compete and winning chunks activate top-down expectations that amplify and focus attention on consistent working memory items, while suppressing inconsistent ones. The ensuing resonance boosts activation levels of selected items and chunks. Because resonance occurs after working memory activation, it can incorporate information presented after intervening silence intervals, so future sounds can influence how we hear past sounds. The model suggests that resonant dynamics enable the brain to learn quickly without suffering catastrophic forgetting, as described within Adaptive Resonance Theory.

Grossberg, Stephen

2003-04-01

110

Extractant composition  

SciTech Connect

This patent describes an organic extracting solution useful for separating elements of the actinide series of the periodic table from elements of the lanthanide series, where both are in trivalent form. It comprises: primary ligand and a secondary ligand, preferably in an organic solvent. The primary ligand is a substituted monothio-1,3-dicarbonyl, which includes a substituted 4-acyl-2-pyrazolin-5-thione, such as 4-benzoly-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione (BMPPT). The secondary ligand is a substituted phosphine oxide, such as trioctylphosphine oxide (TOPO).

Smith, B.F.; Jarvihen, G.D.; Ryan, R.R.

1990-05-08

111

Controlling carbon nanotube photoluminescence using silicon microring resonators.  

PubMed

We report on coupling between semiconducting single-wall carbon nanotubes (s-SWNT) photoluminescence and silicon microring resonators. Polyfluorene extracted s-SWNT deposited on such resonators exhibit sharp emission peaks, due to interaction with the cavity modes of the microring resonators. Ring resonators with radius of 5 ?m and 10 ?m were used, reaching quality factors up to 4000 in emission. These are among the highest values reported for carbon nanotubes coupled with an integrated cavity on silicon platform, which open up the possibility to build s-SWNT based efficient light source on silicon. PMID:24787283

Noury, Adrien; Roux, Xavier Le; Vivien, Laurent; Izard, Nicolas

2014-05-30

112

Signal extraction and optical design for an advanced gravitational-wave interferometer.  

PubMed

We present an experimental demonstration of a locking and control scheme for an interferometer using a power-recycled resonant sideband extraction configuration and show that the measured response to mirror vibrations matches an optical model. We discuss some aspects of resonant sideband extraction that are relevant to gravitational-wave detection. PMID:12638884

Mason, James E; Willems, Phil A

2003-03-01

113

SGEMP for Resonant Structures.  

National Technical Information Service (NTIS)

Most satellites in existence to date are inherently resonant structures. By a resonant structure is meant that the currents and charges induced on it by an external transient electromagnetic source continue to oscillate without significant damping long af...

K. S. H. Lee L. Marin

1975-01-01

114

Neutron resonance averaging  

SciTech Connect

The principles of resonance averaging as applied to neutron capture reactions are described. Several illustrations of resonance averaging to problems of nuclear structure and the distribution of radiative strength in nuclei are provided. 30 refs., 12 figs.

Chrien, R.E.

1986-10-01

115

Resonance in Piezoelectric Vibrators.  

National Technical Information Service (NTIS)

The electrical behavior of a piezoelectric vibrator leads to criteria by which to describe onset and extent of the resonance region. The equi-immittance point is convenient for delimiting the resonance range and assesses the validity of circle representat...

A. Ballato

1969-01-01

116

Pediatric magnetic resonance imaging  

SciTech Connect

This book defines the current clinical potential of magnetic resonance imaging and focuses on direct clinical work with pediatric patients. A section dealing with the physics of magnetic resonance imaging provides an introduction to enable clinicians to utilize the machine and interpret the images. Magnetic resonance imaging is presented as an appropriate imaging modality for pediatric patients utilizing no radiation.

Cohen, M.D.

1986-01-01

117

General resonance spectroscopy  

Microsoft Academic Search

We introduce a generalized definition of resonance which is applicable to systems without well-defined energies and derive an approximate expression for the shape of the resonance curves. We also provide an algorithm for modelling the dynamics of an experimental system using this generalized resonance function.

K. Chang; A. Kodogeorgiou; A. Hübler; E. A. Jackson

1991-01-01

118

Optical Fano resonance of an individual semiconductor nanostructure  

NASA Astrophysics Data System (ADS)

Fano resonances with a characteristic asymmetric line shape can be observed in light scattering, transmission and reflection spectra of resonant optical systems. They result from interference between direct and indirect, resonance-assisted pathways. In the nanophotonics field, Fano effects have been observed in a wide variety of systems, including metallic nanoparticle assemblies, metamaterials and photonic crystals. Their unique properties find extensive use in applications, including optical filtering, polarization selectors, sensing, lasers, modulators and nonlinear optics. We report on the observation of a Fano resonance in a single semiconductor nanostructure, opening up opportunities for their use in active photonic devices. We also show that Fano-resonant semiconductor nanostructures afford the intriguing opportunity to simultaneously measure the far-field scattering response and the near-field energy storage by extracting photogenerated charge. Together they can provide a complete experimental characterization of this type of resonance.

Fan, Pengyu; Yu, Zongfu; Fan, Shanhui; Brongersma, Mark L.

2014-05-01

119

Optical Fano resonance of an individual semiconductor nanostructure.  

PubMed

Fano resonances with a characteristic asymmetric line shape can be observed in light scattering, transmission and reflection spectra of resonant optical systems. They result from interference between direct and indirect, resonance-assisted pathways. In the nanophotonics field, Fano effects have been observed in a wide variety of systems, including metallic nanoparticle assemblies, metamaterials and photonic crystals. Their unique properties find extensive use in applications, including optical filtering, polarization selectors, sensing, lasers, modulators and nonlinear optics. We report on the observation of a Fano resonance in a single semiconductor nanostructure, opening up opportunities for their use in active photonic devices. We also show that Fano-resonant semiconductor nanostructures afford the intriguing opportunity to simultaneously measure the far-field scattering response and the near-field energy storage by extracting photogenerated charge. Together they can provide a complete experimental characterization of this type of resonance. PMID:24747781

Fan, Pengyu; Yu, Zongfu; Fan, Shanhui; Brongersma, Mark L

2014-05-01

120

Phytochemical investigation on leaf extract of Cordia salicifolia Cham.  

PubMed

The dichloromethane extract of leaves of Cordia salicifolia Cham. (Family Boraginaceae) was fractionated by SiO(2) column chromatography and analyzed by gas chromatography, gas chromatography-mass spectrometry, and nuclear magnetic resonance spectroscopy. The apolar extract is characterized by a very high content of (+)-spathulenol (0.53%). The major component of the extract exhibited a very weak activity as an inhibitor of growth of Helicobacter pylori in vitro (minimum inhibitory concentration = 200 microg/mL). PMID:18361757

Menghini, Luigi; Epifano, Francesco; Leporini, Lidia; Pagiotti, Rita; Tirillini, Bruno

2008-03-01

121

Unstable resonator with reduced output coupling.  

PubMed

The properties of a laser beam coupled out of a standard unstable laser resonator are heavily dependent on the chosen resonator magnification. A higher magnification results in a higher output coupling and a better beam quality. But in some configurations, an unstable resonator with a low output coupling in combination with a good beam quality is desirable. In order to reduce the output coupling for a particular resonator, magnification fractions of the outcoupled radiation are reflected back into the cavity. In the confocal case, the output mirror consists of a spherical inner section with a high reflectivity and a flat outer section with a partial reflectivity coating. With the application of the unstable resonator with reduced output coupling (URROC), magnification and output coupling can be adjusted independently from each other and it is possible to get a good beam quality and a high power extraction for lasers with a large low gain medium. The feasibility of this resonator design is examined numerically and experimentally with the help of a chemical oxygen iodine laser. PMID:22722301

Pargmann, Carsten; Hall, Thomas; Duschek, Frank; Grünewald, Karin Maria; Handke, Jürgen

2012-06-20

122

Secular resonances. [of asteroidal dynamics  

NASA Technical Reports Server (NTRS)

Theories and numerical experiments regarding secular resonances are reviewed. The basic dynamics and the positions of secular resonances are discussed, and secular perturbation theories for the nu16 resonance case, the nu6 resonance, and the nu5 resonance are addressed. What numerical experiments have revealed about asteroids located in secular resonances, the stability of secular resonances, variations of eccentricities and inclinations, and chaotic orbits is considered. Resonant transport of meteorites is discussed.

Scholl, H.; Froeschle, CH.; Kinoshita, H.; Yoshikawa, M.; Williams, J. G.

1989-01-01

123

On the Electron Spin Resonances in DNA  

PubMed Central

Iron impurities are shown to account for characteristic electron spin resonances observed in samples of DNA. Comparative e.s.r. measurements on lyophilized samples were done in conjunction with static susceptibility measurements, trace analyses, and molecular degradation experiments to establish this correlation. It has not been possible to extract this iron by treatment with a chelating agent. Such resonances were in part accounted for by ferromagnetic iron contamination during extraction and handling. By modifying the method of Kay, Simmons, and Dounce to eliminate or minimize metal contamination—ionic and ferromagnetic—from sources both internal and external to the tissues used, it was possible to prepare iron-free (< 0.0004 per cent Fe), e.s.r.-free (< 0.001 per cent Fe) DNA. The samples showed 20 per cent protein (determined by the indole method), had a molecular weight 4 × 106 and were undenatured according to the density gradient experiment.

Blois, M. S.; Maling, J. E.; Taskovich, L. T.

1963-01-01

124

Microstrip resonators for electron paramagnetic resonance experiments  

NASA Astrophysics Data System (ADS)

In this article we evaluate the performance of an electron paramagnetic resonance (EPR) setup using a microstrip resonator (MR). The design and characterization of the resonator are described and parameters of importance to EPR and spin manipulation are examined, including cavity quality factor, filling factor, and microwave magnetic field in the sample region. Simulated microwave electric and magnetic field distributions in the resonator are also presented and compared with qualitative measurements of the field distribution obtained by a perturbation technique. Based on EPR experiments carried out with a standard marker at room temperature and a MR resonating at 8.17 GHz, the minimum detectable number of spins was found to be 5×1010 spins/GHz1/2 despite the low MR unloaded quality factor Q0=60. The functionality of the EPR setup was further evaluated at low temperature, where the spin resonance of Cr dopants present in a GaAs wafer was detected at 2.3 K. The design and characterization of a more versatile MR targeting an improved EPR sensitivity and featuring an integrated biasing circuit for the study of samples that require an electrical contact are also discussed.

Torrezan, A. C.; Mayer Alegre, T. P.; Medeiros-Ribeiro, G.

2009-07-01

125

Giant monopole resonance in Pb isotopes  

SciTech Connect

The extraction of the nuclear incompressibility from isoscalar giant monopole resonance (GMR) measurements is analyzed. Pairing may play a role in the shift of the GMR energy between the doubly closed shell {sup 208}Pb nucleus and other Pb isotopes. Pairing effects are predicted microscopically using the constrained Hartree-Fock-Bogoliubov method. Accurate measurements of the GMR in open-shell Pb isotopes are necessary.

Khan, E. [Institut de Physique Nucleaire, Universite Paris-Sud, IN2P3-CNRS, F-91406 Orsay Cedex (France)

2009-11-15

126

Microelectromechanical Systems Resonator Utilizing Torsional-to-Transverse Vibration Conversion  

NASA Astrophysics Data System (ADS)

A silicon microelectromechanical systems (MEMS) resonator utilizing the torsional-to-transverse vibration conversion is designed, fabricated and evaluated. The resonant frequency for the torsional modes mostly depends on only beam length, providing a large tolerance in the fabrication process. It has been, however, a critical issue to investigate the mechanism for generating the torsional vibration and the reduction of motional resistance. We propose a new beam structure, in which four torsion beams are vibrated by twist force generated by a transverse beam. The novel process for fabricating resonators provides a narrow gap surrounded by flat surfaces, which can reduce the motional resistance. The fabricated resonators are measured with a laser-Doppler (LD) vibrometer. The scanning function of the LD vibrometer confirms the torsional-to-transverse vibration conversion has been successfully achieved. The measured resonant frequency, 10.96 MHz, is in good agreement with the simulated one. The Q-factor has been also measured to be as high as 2.2 × 104 in vacuum. The electrical characteristic is evaluated with an impedance analyzer. At the resonant frequency, the extracted motional resistance for the 0.5-?m-gap resonator is 2.0 M?, which is greatly reduced, owing to the narrow gap effect, from that of the 1-?m-gap resonator. The temperature coefficient of the resonant frequency between -40 and 85 °C, has been measured to be -24.4 ppm/deg. The resonant frequency linearly decreases as the temperature rises.

Kiso, Masaya; Okada, Mitsuhiro; Tamano, Akimasa; Fujiura, Hideaki; Miyauchi, Hideo; Niki, Kazuya; Tanigawa, Hiroshi; Suzuki, Kenichiro

2011-06-01

127

Apparatus for hydrocarbon extraction  

DOEpatents

Systems and methods for hydrocarbon extraction from hydrocarbon-containing material. Such systems and methods relate to extracting hydrocarbon from hydrocarbon-containing material employing a non-aqueous extractant. Additionally, such systems and methods relate to recovering and reusing non-aqueous extractant employed for extracting hydrocarbon from hydrocarbon-containing material.

Bohnert, George W.; Verhulst, Galen G.

2013-03-19

128

Localized ferromagnetic resonance force microscopy of permalloy-cobalt films  

SciTech Connect

We report the Ferromagnetic Resonance Force Microscopy (FMRFM) experiments on a combined permalloy-cobalt continuous film. Our studies demonstrate the capability of FMRFM to perform local spectroscopy of different ferromagnetic materials. Theoretical analysis of the uniform resonance mode at the edge of the film provides good quantitative agreement with the experimental data. Our experiments demonstrate the micron scale lateral resolution and allow to extract local magnetic properties in continuous ferromagnetic samples.

Nazaretski, Evgueni [Los Alamos National Laboratory; Movshovich, Roman [Los Alamos National Laboratory; Martin, Ivar [Los Alamos National Laboratory; Cha, Kitty V [Los Alamos National Laboratory; Akhadov, Elshan A [Los Alamos National Laboratory; Obukhov, Yu [OH STATE U; Pelekhov, D C [OH STATE U; Hammel, P C [OH STATE U

2008-01-01

129

Dynamically generated hadron resonances  

NASA Astrophysics Data System (ADS)

As an example of dynamically generated resonances we mention the interaction of vector mesons with baryons within the local hidden gauge formalism which gives rise to a large amount of such states, many of which can be associated to known resonances, while others represent predictions for new resonances. The width of these states coming from decay into pseudoscalar baryon is also addressed. We also mention recent states coming from ?? interaction obtained with Faddeev equations.

Oset, E.; Garzon, E. J.; Xie, Ju Jun; Gonzalez, P.; Ramos, A. Torres; Martinez, A.

2011-10-01

130

Secular resonances - New results  

Microsoft Academic Search

Results are presented from a numerical integration, in the frame of the four-body problem sun-Jupiter-Saturn-asteroid, of the orbit of the asteroid 1974 MA. This asteroid is an earth-crosser located in a region where three resonances overlap: the two secular resonances nu5 and nu6 and the mean motion resonance 5\\/1. The numerical integration yields a qualitative orbital evolution of this particular

Ch. Froeschle; H. Scholl

1988-01-01

131

Acoustic Levitator Maintains Resonance  

NASA Technical Reports Server (NTRS)

Transducer loading characteristics allow resonance tracked at high temperature. Acoustic-levitation chamber length automatically adjusted to maintain resonance at constant acoustic frequency as temperature changes. Developed for containerless processing of materials at high temperatures, system does not rely on microphones as resonance sensors, since microphones are difficult to fabricate for use at temperatures above 500 degrees C. Instead, system uses acoustic transducer itself as sensor.

Barmatz, M. B.; Gaspar, M. S.

1986-01-01

132

Resonant guided wave networks.  

PubMed

A resonant guided wave network is an optical materials design consisting of power-splitting elements arranged at the nodes of a waveguide network. The resulting wave dispersion depends on the network layout due to localized resonances at several length scales in the network. These structures exhibit both localized resonances with a Q approximately 80 at 1550 nm wavelength as well as photonic bands and band gaps in large periodic networks at infrared wavelengths. PMID:20481961

Feigenbaum, Eyal; Atwater, Harry A

2010-04-01

133

Resonant Optical Antennas  

Microsoft Academic Search

We have fabricated nanometer-scale gold dipole antennas designed to be resonant at optical frequencies. On resonance, strong field enhancement in the antenna feed gap leads to white-light supercontinuum generation. The antenna length at resonance is considerably shorter than one-half the wavelength of the incident light. This is in contradiction to classical antenna theory but in qualitative accordance with computer simulations

P. Mühlschlegel; H.-J. Eisler; O. J. F. Martin; B. Hecht; D. W. Pohl

2005-01-01

134

Resonant nonlinear ultrasound spectroscopy  

Microsoft Academic Search

Components with defects are identified from the response to strains applied at acoustic and ultrasound frequencies. The relative resonance frequency shift .vertline..DELTA..function.\\/.function..sub.0.vertline., is determined as a function of applied strain amplitude for an acceptable component, where .function..sub.0 is the frequency of the resonance peak at the lowest amplitude of applied strain and .DELTA..function. is the frequency shift of the resonance

Paul A. Johnson; James A. TenCate; Robert A. Guyer; Koen E. A. Van Den Abeele

2001-01-01

135

Resonances in accelerators  

SciTech Connect

Various resonances important in accelerators are analyzed, with the intention of demonstrating their essential similarity. Transverse instabilities of bunched electron beams are emphasized, including beam--beam effects.

Talman, R.

1987-02-25

136

Resonances in accelerators  

SciTech Connect

Various resonances important in accelerators are analyzed, with the intention of demonstrating their essential similarity. Transverse instabilities of bunched electron beams are emphasized, including beam-beam effects.

Talman, R.

1986-06-01

137

Giant resonance decay  

SciTech Connect

Decay studies of giant multipole resonances are discussed, emphasizing the role of Coulomb excitation with intermediate energy heavy ions, which can provide very large cross sections for both isoscalar and isovector resonances. We discuss measurement of the photon decay of one and two phonon giant resonances, reporting results where available. It is pointed out throughout the presentation that the use of E1 photons as a tag'' provides a means to observe weakly excited resonances that cannot be observed in the singles spectra. 30 refs., 16 figs., 1 tab.

Beene, J.R.; Bertrand, F.E.

1990-01-01

138

Superconducting Microwave Resonators  

NASA Astrophysics Data System (ADS)

High quality factor superconducting microwave resonators play a key role in applications to quantum computation and single photon detection schemes. We have optimized our aluminum quarter wavelength coplanar waveguide resonators in an effort to improve energy decay times. As the characteristic decay times in our samples begin to approach the requirements set out by fault tolerant error correction algorithms, reproducibility becomes a growing focus. Consistent reproduction of high quality factor resonators requires reliable determination of device parameters independent of experimental imperfections and environmental influences. These measurements permit an improved understanding of the variations between nominally identical resonators as well as variations in an individual sample over time. Recent experimental results will be discussed.

Neill, Charles; Megrant, Anthony; Lenander, Mike; Barends, Rami; Wenner, Jim; White, Ted; Sank, Daniel; Chen, Yu; Yin, Yi; Chiaro, Ben; Kelly, Julian; O'Malley, Peter; Roushan, Pedram; Lucero, Erik; Vainsencher, Amit; Bochmann, Joerg; Mariantoni, Matteo; Axline, Chris; Martinis, John; Cleland, Andrew

2012-02-01

139

Stochastic resonance of quantum discord  

SciTech Connect

We study the stochastic resonance of quantum discord (''discord resonance'') in coupled quantum systems and make a comparison with the stochastic resonance of entanglement (''entanglement resonance''). It is found that the discord resonance is much more robust against dephasing noise and thermal effects than the entanglement resonance. We also show that, unlike the entanglement resonance, the level of dissipation at which the discord resonance occurs is not sensitive to dephasing noise. These results suggest that it is easier to detect the discord resonance in actual experiments, where the dephasing noise and temperature are difficult to control.

Lee, Chee Kong [Centre for Quantum Technologies, National University of Singapore, 117543 Singapore (Singapore); Kwek, Leong Chuan [Centre for Quantum Technologies, National University of Singapore, 117543 Singapore (Singapore); National Institute of Education and Institute of Advanced Studies, Nanyang Technological University, 637616 Singapore (Singapore); Cao, Jianshu [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2011-12-15

140

Resonant elastic light scattering and coherence relaxation in semiconductor structures  

NASA Astrophysics Data System (ADS)

The relevance of resonant elastic light scattering to the relaxation of optically induced coherence in semiconductor structures is discussed. It is shown that important information on the intrinsic dephasing time of the optical excitation can indeed be extracted from the resonant Rayleigh scattering signal even in the case of inhomogeneously broadened transitions. Finally, a time-resolved technique is illustrated that is capable of yielding direct access to the coherence relaxation times in both bulk and quantum-confined semiconductor structures as long as the excitation is chosen so as to be resonant with the material transition. 78.35.+c.

Gurioli, M.; Bogani, F.; Ceccherini, S.; Vinattieri, A.; Colocci, M.

1996-06-01

141

Resonance Conditions of Open Resonators at Microwave Frequencies.  

National Technical Information Service (NTIS)

The paper presents an extension of Vajnshtejn's approach for computing the resonance frequencies and loss factors of Fabry-Perot (FP) resonators at microwave frequencies. Numerical results are presented for FP resonators operated at microwave through mill...

T. Itch R. Mittra

1973-01-01

142

The resonator handbook  

NASA Technical Reports Server (NTRS)

The purpose of this work is to extend resonator theory into the region in which the planar mirror is quite small. Results of the theoretical description are then extended to resonator design and experimental arrangements as discussed in further sections of this work. Finally, a discussion of dielectric measurements for small samples is included as a specific application of this work.

Cook, Jerry D.; Zhou, Shiliang

1993-01-01

143

The Concept of Resonance  

ERIC Educational Resources Information Center

A general example of a delocalization system associated with a higher energy than the localized one, which suggests that it is wrong to consider delocalization as equivalent to resonance stabilization, is presented. The meaning of resonance energy as it appears in valence bond theory is described as the lowering of the calculated ground-state…

Truhlar, Donald G.

2007-01-01

144

Resonance characteristics of waveguide-coupled polyimide microring resonator  

Microsoft Academic Search

We report for the first time on the resonance characteristics of a polyimide-based micro-ring resonator model. The resonator consists of a microring coupled to a pair of waveguides. Using the finite-difference time-domain method, we were able to obtain resonance peaks, from which the resonance wavelength could be identified. For a resonator with a microring of 10 ?m diameter, known as

Hak-Phil Lee; Jong-Jin Park; Hyun-Ho Ryoo; Seung Gol Lee; O Beom Hoan; El-Hang Lee

2003-01-01

145

Resonant snubber inverter  

DOEpatents

A resonant, snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the main inverter switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter.

Lai, Jih-Sheng (Knoxville, TN); Young, Sr., Robert W. (Oak Ridge, TN); Chen, Daoshen (Knoxville, TN); Scudiere, Matthew B. (Oak Ridge, TN); Ott, Jr., George W. (Knoxville, TN); White, Clifford P. (Knoxville, TN); McKeever, John W. (Oak Ridge, TN)

1997-01-01

146

Resonant snubber inverter  

DOEpatents

A resonant, snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the main inverter switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter. 14 figs.

Lai, J.S.; Young, R.W. Sr.; Chen, D.; Scudiere, M.B.; Ott, G.W. Jr.; White, C.P.; McKeever, J.W.

1997-06-24

147

Unfolding the Second Riemann sheet with Pade Approximants: hunting resonance poles  

SciTech Connect

Based on Pade Theory, a new procedure for extracting the pole mass and width of resonances is proposed. The method is systematic and provides a model-independent treatment for the prediction and the errors of the approximation.

Masjuan, Pere [Faculty of Physics, University of Vienna. Boltzmanngasse 5, A-1090 Wien (Austria); Departamento de Fisica Teorica y del Cosmos, Universidad de Granada, Campus de Fuentenueva, E-18071 Granada (Spain)

2011-05-23

148

Chaotic spectra: How to extract dynamic information  

SciTech Connect

Nonlinear dynamics is applied to chaotic unassignable atomic and molecular spectra with the aim of extracting detailed information about regular dynamic motions that exist over short intervals of time. It is shown how this motion can be extracted from high resolution spectra by doing low resolution studies or by Fourier transforming limited regions of the spectrum. These motions mimic those of periodic orbits (PO) and are inserts into the dominant chaotic motion. Considering these inserts and the PO as a dynamically decoupled region of space, resonant scattering theory and stabilization methods enable us to compute ladders of resonant states which interact with the chaotic quasi-continuum computed in principle from basis sets placed off the PO. The interaction of the resonances with the quasicontinuum explains the low resolution spectra seen in such experiments. It also allows one to associate low resolution features with a particular PO. The motion on the PO thereby supplies the molecular movements whose quantization causes the low resolution spectra. Characteristic properties of the periodic orbit based resonances are discussed. The method is illustrated on the photoabsorption spectrum of the hydrogen atom in a strong magnetic field and on the photodissociation spectrum of H/sub 3//sup +/. Other molecular systems which are currently under investigation using this formalism are also mentioned. 53 refs., 10 figs., 2 tabs.

Taylor, H.S.; Gomez Llorente, J.M.; Zakrzewski, J.; Kulander, K.C.

1988-10-01

149

P11 Resonances with Dubna-Mainz-Taipei dynamical model for ?N scattering and pion electromagnetic production  

NASA Astrophysics Data System (ADS)

We present the results on P11 resonances obtained with Dubna-Mainz-Taipei (DMT) dynamical model for pion-nucleon scattering and pion electromagnetic production. The extracted values agree well, in general, with PDG values. One pole is found corresponding to the Roper resonance and two more resonances are definitely needed in DMT model. We further find indication for a narrow P11 resonance at around 1700 MeV with a width ~ 50 MeV in both ?N and ?? reactions.

Yang, Shin Nan; Kamalov, S. S.; Tiator, L.

2012-04-01

150

Formation of pulses with controlled parameters in a resonance microwave compressor employing oscillation-mode transformation  

NASA Astrophysics Data System (ADS)

Results of an experimental study of the formation of rf pulses with controlled power, duration, repetition rate, and envelope parameters in a resonance compressor employing oscillation-mode transformation are presented. The pulse parameters are varied by using tuned intermodal coupling elements. A possibility of the formation of a series of subsecond and nanosecond rf pulses in the partial extraction of energy and nanosecond pulses of various durations in single complete extraction of energy from the compressor resonator is shown.

Avgustinovich, V. A.; Artemenko, S. N.; Igumnov, V. S.; Yushkov, Yu. G.

2013-09-01

151

Simulations of thermo-elastic losses in a meta-material bulk bar resonator  

Microsoft Academic Search

In this paper we investigate the thermo-elastic losses in bulk mode bar MEMS resonators implemented using a meta-material composed of square inclusions. A quasi-static extraction technique is used to extract the effective thermal and mechanical properties of the meta-material. These effective parameters are used in the resonator simulation, greatly decreasing the required simulation time required to simulate the thermo-elastic losses

R. Jansen; X. Rottenberg; V. Rochus; H. A. C. Tilmans

2012-01-01

152

GaN resonant cavity light-emitting diodes for plastic optical fiber applications  

Microsoft Academic Search

The optical designs of resonant GaN light-emitting diodes (LEDs) have been determined for maximum extraction efficiency into typical plastic optical fiber of numerical aperture 0.5. An optimum extraction efficiency of 3.9% can be achieved for a practical resonant cavity LED (RCLED), taking account of current growth and processing considerations. The optimized device is a metal-active layer distributed Bragg reflector construction.

A. J. Shaw; A. L. Bradley; J. F. Donegan; J. G. Lunney

2004-01-01

153

LABCOM resonator Phase 3  

SciTech Connect

The purpose of this project was to develop quartz crystal resonator designs, production processes, and test capabilities for 5-MHz, 6.2-MHz, and 10-MHz resonators for Tactical Miniature Crystal Oscillator (TMXO) applications. GE Neutron Devices (GEND) established and demonstrated the capability to produce and test quartz crystal resonators for use in the TMXO developed by the US Army ERADCOM (now LABCOM). The goals in this project were based on the ERADCOM statement of work. The scope of work indicated that the resonator production facilities for this project would not be completely independent, but that they would be supported in part by equipment and processes in place at GEND used in US Department of Energy (DOE) work. In addition, provisions for production test equipment or or eventual technology transfer costs to a commercial supplier were clearly excluded from the scope of work. The demonstrated technical capability of the deep-etched blank design is feasible and practical. It can be manufactured in quantity with reasonable yield, and its performance is readily predictable. The ceramic flatpack is a very strong package with excellent hermeticity. The four-point mount supports the crystal to reasonable shock levels and does not perturb the resonator's natural frequency-temperature behavior. The package can be sealed with excellent yields. The high-temperature, high-vacuum processing developed for the TMXO resonator, including bonding the piezoid to its mount with conductive polyimide adhesive, is consistent with precision resonator fabrication. 1 fig., 6 tabs.

Keres, L.J.

1990-11-01

154

Tunable multiwalled nanotube resonator  

DOEpatents

A tunable nanoscale resonator has potential applications in precise mass, force, position, and frequency measurement. One embodiment of this device consists of a specially prepared multiwalled carbon nanotube (MWNT) suspended between a metal electrode and a mobile, piezoelectrically controlled contact. By harnessing a unique telescoping ability of MWNTs, one may controllably slide an inner nanotube core from its outer nanotube casing, effectively changing its length and thereby changing the tuning of its resonance frequency. Resonant energy transfer may be used with a nanoresonator to detect molecules at a specific target oscillation frequency, without the use of a chemical label, to provide label-free chemical species detection.

Zettl, Alex K. (Kensington, CA); Jensen, Kenneth J. (Berkeley, CA); Girit, Caglar (Albany, CA); Mickelson, William E. (San Francisco, CA); Grossman, Jeffrey C. (Berkeley, CA)

2011-03-29

155

Characterization and self-test of electrostatically tunable resonators for frequency selective vibration measurements  

Microsoft Academic Search

In this paper, we present a measurement technique for the characterization and the self-test of Single Crystal Reactive Etching and Metallization (SCREAM)-fabricated tunable resonators. Such kinds of structures can be used for frequency selective vibration detection. Spectral information is extracted directly by mechanical filtering at the resonance frequency of the sensor structures. Flexible adjustment of the measurement range is obtained

Dirk Scheibner; Jan Mehner; Danny Reuter; Ulf Kotarsky; Thomas Gessner; Wolfram Dötzel

2004-01-01

156

Magnetic resonance spectroscopy investigations of brown adipose tissue and isolated brown adipocytes  

Microsoft Academic Search

Brown adipose tissue and collagenase-isolated brown adipocytes were investigated in rats by means of 'H and 1% nuclear magnetic resonance spectroscopy. After chloroform- methanol extraction of brown adipose tissue, proton and natural abundance I3C spectra of the chloroform fraction showed resonances attributable to triglycerides, and were qualitatively similar to those of the corresponding fraction of white adipose tissue. By means

Carlo Zancanaro; Rita Nano; Carla Marchioro; Andrea Sbarbati; Andrea Boicelli; Francesco Osculati

157

Accurate and direct characterization of high-Q microwave resonators using one-port measurement  

Microsoft Academic Search

An accurate and direct characterization of high-Q microwave resonators using one-port vector network measurement technique is presented. In this characterization, the delay due to the connector between the resonator and network analyzer is first deembedded. The elements of the equivalent-circuit of the resonator are then readily extracted from the experimental data in a straightforward manner without any numerical optimization. The

Lye Heng Chua; Dariush Mirshekar-Syahkal

2003-01-01

158

Complex natural resonances for breast tissues with complex morphology  

Microsoft Academic Search

We investigate the Complex Natural Resonances (CNRs) of the malignant breast tissues with complex peripheries. The tissues are modeled as lossy dielectric objects with complex geometries which are expected to have different CNRs compared to those with smooth surfaces. Since the breast tissues are embedded inside inhomogeneous lossy breast medium, it is very important to ensure that a particular extracted

Fan Yang; Ananda Sanagavarapu Mohan

2011-01-01

159

An astigmatic unstable resonator with an intracavity deformable mirror  

Microsoft Academic Search

Many side-pumped lasers exhibit significant index gradients across the gain region aperture. For pulsed lasers where these gradients are time dependent, extraction with good beam quality requires the use of an adaptive optic. Since these inhomogeneities are systematic, wavefront correction can be performed with a model deformable mirror. We have designed a resonator which uses a cylindrically deformable mirror to

D. R. Neal; P. L. McMillin; R. B. Michie

1991-01-01

160

An Astigmatic Unstable Resonator with an Intracavity Deformable Mirror  

Microsoft Academic Search

ABSTRACT Many side-pumped lasers exhibit significant index gradients across the gain region aperture. For pulsed lasers where these gradients are time dependent, extraction with good beam quality requires the use of an adaptive optic. Since these inhomogeneities are systematic, wavefront correction can be performed with a modal deformable mirror. We have designed a resonator which uses a cylindrically deformable mirror

D. R. Neal; P. L. Mcmillin; R. B. Michie

161

Transmission Lines - Resonant Sections.  

National Technical Information Service (NTIS)

Explains use of resonant sections as a metallic insulator harmonic filter matching transformers, quarter and half waves, line balance converter, and capacitive coupled joint. Lecher line oscillator and a typical duplexer are also discussed.

1994-01-01

162

Resonant ultrasound spectroscopy  

DOEpatents

A resonant ultrasound spectroscopy method provides a unique characterization of an object for use in distinguishing similar objects having physical differences greater than a predetermined tolerance. A resonant response spectrum is obtained for a reference object by placing excitation and detection transducers at any accessible location on the object. The spectrum is analyzed to determine the number of resonant response peaks in a predetermined frequency interval. The distribution of the resonance frequencies is then characterized in a manner effective to form a unique signature of the object. In one characterization, a small frequency interval is defined and stepped though the spectrum frequency range. Subsequent objects are similarly characterized where the characterizations serve as signatures effective to distinguish objects that differ from the reference object by more than the predetermined tolerance.

Migliori, Albert (Santa Fe, NM)

1991-01-01

163

Micro-machined resonator  

DOEpatents

A micro-machined resonator, typically quartz, with upper and lower micro-machinable support members, or covers, having etched wells which may be lined with conductive electrode material, between the support members is a quartz resonator having an energy trapping quartz mesa capacitively coupled to the electrode through a diaphragm; the quartz resonator is supported by either micro-machined cantilever springs or by thin layers extending over the surfaces of the support. If the diaphragm is rigid, clock applications are available, and if the diaphragm is resilient, then transducer applications can be achieved. Either the thin support layers or the conductive electrode material can be integral with the diaphragm. In any event, the covers are bonded to form a hermetic seal and the interior volume may be filled with a gas or may be evacuated. In addition, one or both of the covers may include oscillator and interface circuitry for the resonator.

Godshall, Ned A. (Albuquerque, NM); Koehler, Dale R. (Albuquerque, NM); Liang, Alan Y. (Albuquerque, NM); Smith, Bradley K. (Albuquerque, NM)

1993-01-01

164

Magnetic Resonance Imaging (MRI).  

National Technical Information Service (NTIS)

Magnetic resonance imaging (MRI) is a method of graphically representing the distribution of water and other hydrogen-rich molecules in the human body. Imaging parameters are complex. Although MR images may demonstrate anatomy as do conventional radiograp...

E. Feigenbaum

1985-01-01

165

Double-resonance antenna  

NASA Astrophysics Data System (ADS)

This article describes a new kind of microstrip antenna that uses double-resonance phenomenon to radiative as a short dipole. The working wavelength of this antenna is approximately eight times the maximum dimension of the antenna.

Seaux, J. P.; Reineix, A.; Jecko, B.

1991-09-01

166

Magnetic Resonance Facility.  

National Technical Information Service (NTIS)

Magnetic Resonance Facility capabilities and applications at NREL's National Bioenergy Center. Liquid and solid-state analysis capability for a variety of biomass, photovoltaic, and materials characterization applications across NREL. NREL scientists anal...

2012-01-01

167

Magnetostrictive resonance excitation.  

National Technical Information Service (NTIS)

The resonance frequency spectrum of a magnetostrictive sample is remotely determined by exciting the magnetostrictive property with an oscillating magnetic field. The permeability of a magnetostrictive material and concomitant coupling with a detection co...

R. B. Schwartz V. T. Kuokkala

1990-01-01

168

Magnetic resonance imaging  

SciTech Connect

This book contains the following four major sections: physics and chemistry, relaxation/relaxometry, instrumentation, research areas. The authors discuss instrumentation and technical approaches in magnetic resonance (MR) imaging.

Partain, C.L.; Price, R.R.; Patton, J.A.; Kulkarni, M.V.; James, A.E.

1988-01-01

169

Hexagonal quartz resonator  

DOEpatents

A generally flat, relatively thin AT-cut piezoelectric resonator element structured to minimize the force-frequency effect when mounted and energized in a housing. The resonator is in the form of an equilateral hexagon with the X crystallographic axis of the crystal passing through one set of opposing corners with mounting being effected at an adjacent set of corners respectively .+-.60.degree. away from the X axis which thereby results in a substantially zero frequency shift of the operating frequency.

Peters, Roswell D. M. (Rustburg, VA)

1982-01-01

170

Resonant nonlinear ultrasound spectroscopy  

DOEpatents

Components with defects are identified from the response to strains applied at acoustic and ultrasound frequencies. The relative resonance frequency shift .vertline..DELTA..function./.function..sub.0.vertline., is determined as a function of applied strain amplitude for an acceptable component, where .function..sub.0 is the frequency of the resonance peak at the lowest amplitude of applied strain and .DELTA..function. is the frequency shift of the resonance peak of a selected mode to determine a reference relationship. Then, the relative resonance frequency shift .vertline..DELTA..function./.function..sub.0 is determined as a function of applied strain for a component under test, where fo .function..sub.0 the frequency of the resonance peak at the lowest amplitude of applied strain and .DELTA..function. is the frequency shift of the resonance peak to determine a quality test relationship. The reference relationship is compared with the quality test relationship to determine the presence of defects in the component under test.

Johnson, Paul A. (Santa Fe, NM); TenCate, James A. (Los Alamos, NM); Guyer, Robert A. (Amherst, MA); Van Den Abeele, Koen E. A. (Sint-Niklaas, BE)

2001-01-01

171

Anomalous Diffusion Near Resonances  

SciTech Connect

Synchro-betatron resonances can lead to emittance growth and the loss of luminosity. We consider the detailed dynamics of a bunch near such a low order resonance driven by crossing angles at the collision points. We characterize the nature of diffusion and find that it is anomalous and sub-diffusive. This affects both the shape of the beam distribution and the time scales for growth. Predictions of a simplified anomalous diffusion model are compared with direct simulations. Transport of particles near resonances is still not a well understood phenomenon. Often, without justification, phase space motion is assumed to be a normal diffusion process although at least one case of anomalous diffusion in beam dynamics has been reported [1]. Here we will focus on the motion near synchro-betatron resonances which can be excited by several means, including beams crossing at an angle at the collision points as in the LHC. We will consider low order resonances which couple the horizontal and longitudinal planes, both for simplicity and to observe large effects over short time scales. While the tunes we consider are not practical for a collider, nonetheless the transport mechanisms we uncover are also likely to operate at higher order resonances.

Sen, Tanaji; /Fermilab

2010-05-01

172

Time scales in nuclear giant resonances  

SciTech Connect

We propose a general approach to characterise fluctuations of measured cross sections of nuclear giant resonances. Simulated cross sections are obtained from a particular, yet representative, self-energy that contains all information about fragmentations. Using a wavelet analysis, we demonstrate the extraction of time scales of cascading decays into configurations of different complexity of the resonance. We argue that the spreading widths of collective excitations in nuclei are determined by the number of fragmentations as seen in the power spectrum. An analytic treatment of the wavelet analysis using a Fourier expansion of the cross section confirms this principle. A simple rule for the relative lifetimes of states associated with hierarchies of different complexity is given.

Heiss, W. D. [National Institute for Theoretical Physics, Stellenbosch Institute for Advanced Study, and Institute of Theoretical Physics, University of Stellenbosch, 7602 Matieland (South Africa); Nazmitdinov, R. G. [Department de Fisica, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain); Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, RU-141980 Dubna (Russian Federation); Smit, F. D. [iThemba LABS, Post Office Box 722, Somerset West 7129 (South Africa)

2010-03-15

173

Alfven wave cyclotron resonance heating  

SciTech Connect

The resonance absorption of fast Alfven waves at the proton ctclotron resonance of a predominately deuterium plasma is investigated. An approximate dispersion relation is derived, valid in the vicinity of the resonance, which permits an exact calculation of transmission and reflection coefficients. For reasonable plasma parameters significant linear resonance absorption is found.

White, R.B.; Yosikawa, S.; Oberman, C.

1981-02-01

174

Microwave dielectric resonator-tuning  

Microsoft Academic Search

Dielectric resonators have applications as low-loss compact filters in the microwave region. Tuning characteristics of dielectric resonators that might allow for temperature compensation and frequency variability were investigated both theoretically and experimentally at L band. A secondary dielectric resonator that is offset in frequency from the tuned resonator provides a maximum tuning range of approximately 10 percent before an additional

U. H. W. Lammers; M. R. Stiglitz

1974-01-01

175

PITFALLS OF SEQUENTIAL EXTRACTION  

EPA Science Inventory

An increasing number of researchers are using sequential extraction to determine the speciation of trace elements in sediments. nfortunately, sequential extraction methods have not been successfully validated. he results are simply taken as providing "operational definitions" of ...

176

Method of infusion extraction  

NASA Technical Reports Server (NTRS)

Apparatus and method of removing desirable constituents from an infusible material by infusion extraction, where a piston operating in a first chamber draws a solvent into the first chamber where it may be heated, and then moves the heated solvent into a second chamber containing the infusible material, and where infusion extraction takes place. The piston then moves the solvent containing the extract through a filter into the first chamber, leaving the extraction residue in the second chamber.

Chang-Diaz, Franklin R. (Inventor)

1989-01-01

177

Standardization of allergen extracts.  

PubMed

A review of clinical and experimental data pertaining to the standardization of allergenic extracts is presented. Various problems facing practicing allergists are outlined: potency and stability of extracts the reactivity of the patient, in vitro and in vivo methods for assessing potency. Practical recommendations for allergists concerning allergenic extracts and their use are enumerated. PMID:82414

Ribon, A; Gavencak, J

1978-11-01

178

Uranium extraction process  

SciTech Connect

Uranium is extracted from wet process phosphoric acid by extraction with a mixture of a diorganophosphate and a neutral phosphorus compound, which is preferably a triorgano phosphine oxide, in the presence of nitrate to form an organic extract layer containing uranium and an aqueous acid layer, which are separated.

Rose, M.A.

1983-05-03

179

Precolumn for extract concentration  

NASA Technical Reports Server (NTRS)

AUDRI requires test sample separation into organic compound families for subsequent insertion into several parallel chromatographs. Sample is first extracted by selective organic solvents. Solvent is then removed from extract to increase extract-to-solvent ratio, increasing system sensitivity. Backflushing of precolumn serves as cleanser.

Jahnsen, V. J.; Bloom, W. G.

1976-01-01

180

Optimal cuts to extract the third-order elastic constants of langasite single crystals  

Microsoft Academic Search

Optimal cuts to determine the third-order elastic constants of langasite single crystals by the resonator meth- od are proposed. By designing a small number of langasite resonators with optimal cut angles and measuring their force- frequency effects, the third-order elastic constants of langas- ite single crystals may be extracted separately. The numerical method to search for these optimal cut angles

Haifeng Zhang

2011-01-01

181

Metabolomic alterations in elicitor treated Silybum marianum suspension cultures monitored by nuclear magnetic resonance spectroscopy  

Microsoft Academic Search

A comprehensive metabolomic profiling of Silybum marianum (L.) Gaernt cell cultures elicited with yeast extract or methyl jasmonate for the production of silymarin was carried out using one- and two-dimensional nuclear magnetic resonance spectroscopy. With these techniques we were able to detect both temporal quantitative variations in the metabolite pool in yeast extract-elicited cultures and qualitative differences in cultures treated

Angeles Sánchez-Sampedro; Hye Kyong Kim; Young Hae Choi; Robert Verpoorte; Purificación Corchete

2007-01-01

182

Review: Magnetic resonance imaging techniques in ophthalmology  

PubMed Central

Imaging the eye with magnetic resonance imaging (MRI) has proved difficult due to the eye’s propensity to move involuntarily over typical imaging timescales, obscuring the fine structure in the eye due to the resulting motion artifacts. However, advances in MRI technology help to mitigate such drawbacks, enabling the acquisition of high spatiotemporal resolution images with a variety of contrast mechanisms. This review aims to classify the MRI techniques used to date in clinical and preclinical ophthalmologic studies, describing the qualitative and quantitative information that may be extracted and how this may inform on ocular pathophysiology.

Fagan, Andrew J.

2012-01-01

183

Proton Spin Structure in the Resonance Region  

NASA Astrophysics Data System (ADS)

We have examined the spin structure of the proton in the region of the nucleon resonances (1.085GeVextracted the asymmetries A1 and A2, and the spin structure functions g1 and g2. We found a notably nonzero A?, significant contributions from higher-twist effects, and only weak support for polarized quark-hadron duality.

Wesselmann, F. R.; Slifer, K.; Tajima, S.; Aghalaryan, A.; Ahmidouch, A.; Asaturyan, R.; Bloch, F.; Boeglin, W.; Bosted, P.; Carasco, C.; Carlini, R.; Cha, J.; Chen, J. P.; Christy, M. E.; Cole, L.; Coman, L.; Crabb, D.; Danagoulian, S.; Day, D.; Dunne, J.; Elaasar, M.; Ent, R.; Fenker, H.; Frlez, E.; Gan, L.; Gaskell, D.; Gomez, J.; Hu, B.; Jones, M. K.; Jourdan, J.; Keith, C.; Keppel, C. E.; Khandaker, M.; Klein, A.; Kramer, L.; Liang, Y.; Lichtenstadt, J.; Lindgren, R.; Mack, D.; McKee, P.; McNulty, D.; Meekins, D.; Mkrtchyan, H.; Nasseripour, R.; Niculescu, I.; Normand, K.; Norum, B.; Pocanic, D.; Prok, Y.; Raue, B.; Reinhold, J.; Roche, J.; Rohe, D.; Rondón, O. A.; Savvinov, N.; Sawatzky, B.; Seely, M.; Sick, I.; Smith, C.; Smith, G.; Stepanyan, S.; Tang, L.; Testa, G.; Vulcan, W.; Wang, K.; Warren, G.; Wood, S.; Yan, C.; Yuan, L.; Yun, J.; Zeier, M.; Zhu, H.

2007-03-01

184

Novel multisample dielectric resonators for electron paramagnetic resonance spectroscopy  

NASA Astrophysics Data System (ADS)

We have developed and tested two types of novel dielectric resonators for simultaneous recording of electron paramagnetic resonance (EPR) spectra from two to four samples. The resonator of the first type contains two holes, and the other resonator contains four holes for introduction of the samples. Also, the resonator structure includes a pair of gradient coils. Dielectric resonators made of materials with high dielectric constant with low losses can be inserted into the standard EPR cavity or waveguide in the maximum microwave magnetic field. Gradient coils are located outside the cavity (or waveguide) so that their axes are parallel to the static magnetic field. Computer simulations were made to obtain microwave characteristics of the resonators such as resonant frequency, sizes, and distribution of the fields. Spacing of the point samples and optimum value of the magnetic-field gradient have been chosen correctly. The designed resonators can be applied in express analysis using EPR technique, for instance.

Golovina, Iryna S.; Kolesnik, Sergiy P.; Geifman, Ilia N.; Belous, Anatoliy G.

2010-04-01

185

Resonant ultrasound spectrometer  

DOEpatents

An ultrasound resonant spectrometer determines the resonant frequency spectrum of a rectangular parallelepiped sample of a high dissipation material over an expected resonant response frequency range. A sample holder structure grips corners of the sample between piezoelectric drive and receive transducers. Each transducer is mounted on a membrane for only weakly coupling the transducer to the holder structure and operatively contacts a material effective to remove system resonant responses at the transducer from the expected response range. i.e., either a material such as diamond to move the response frequencies above the range or a damping powder to preclude response within the range. A square-law detector amplifier receives the response signal and retransmits the signal on an isolated shield of connecting cabling to remove cabling capacitive effects. The amplifier also provides a substantially frequency independently voltage divider with the receive transducer. The spectrometer is extremely sensitive to enable low amplitude resonance to be detected for use in calculating the elastic constants of the high dissipation sample.

Migliori, Albert (Santa Fe, NM); Visscher, William M. (Los Alamos, NM); Fisk, Zachary (Santa Fe, NM)

1990-01-01

186

MACHINERY RESONANCE AND DRILLING  

SciTech Connect

New developments in vibration analysis better explain machinery resonance, through an example of drill bit chattering during machining of rusted steel. The vibration of an operating drill motor was measured, the natural frequency of an attached spring was measured, and the two frequencies were compared to show that the system was resonant. For resonance to occur, one of the natural frequencies of a structural component must be excited by a cyclic force of the same frequency. In this case, the frequency of drill bit chattering due to motor rotation equaled the spring frequency (cycles per second), and the system was unstable. A soft rust coating on the steel to be drilled permitted chattering to start at the drill bit tip, and the bit oscillated on and off of the surface, which increased the wear rate of the drill bit. This resonant condition is typically referred to as a motor critical speed. The analysis presented here quantifies the vibration associated with this particular critical speed problem, using novel techniques to describe resonance.

Leishear, R.; Fowley, M.

2010-01-23

187

Automatic Landmark Extraction using Self-Organising Maps  

Microsoft Academic Search

A large number of registration techniques rely on manually selected landmark points. A system based on neural principles has been developed to automatically extract landmark types and positional information from magnetic resonance images. A single self-organising map is used to develop the features (landmark types) so that the final landmarks represent statistically signific ant contour sections. The combination of landmark

Theo Sabisch; Alistair Ferguson; Hamid Bolouri

1997-01-01

188

Quartz resonator processing system  

DOEpatents

Disclosed is a single chamber ultra-high vacuum processing system for the oduction of hermetically sealed quartz resonators wherein electrode metallization and sealing are carried out along with cleaning and bake-out without any air exposure between the processing steps. The system includes a common vacuum chamber in which is located a rotatable wheel-like member which is adapted to move a plurality of individual component sets of a flat pack resonator unit past discretely located processing stations in said chamber whereupon electrode deposition takes place followed by the placement of ceramic covers over a frame containing a resonator element and then to a sealing stage where a pair of hydraulic rams including heating elements effect a metallized bonding of the covers to the frame.

Peters, Roswell D. M. (Rustburg, VA)

1983-01-01

189

Thin film resonator technology.  

PubMed

Advances in wireless systems have placed increased demands on high performance frequency control devices for operation into the microwave range. With spectrum crowding, high bandwidth requirements, miniaturization, and low cost requirements as a background, the thin film resonator technology has evolved into the mainstream of applications. This technology has been under development for over 40 years in one form or another, but it required significant advances in integrated circuit processing to reach microwave frequencies and practical manufacturing for high-volume applications. This paper will survey the development of the thin film resonator technology and describe the core elements that give rise to resonators and filters for today's high performance wireless applications. PMID:16048174

Lakin, Kenneth M

2005-05-01

190

Magnetostrictive resonance excitation  

DOEpatents

The resonance frequency spectrum of a magnetostrictive sample is remotely determined by exciting the magnetostrictive property with an oscillating magnetic field. The permeability of a magnetostrictive material and concomitant coupling with a detection coil varies with the strain in the material whereby resonance responses of the sample can be readily detected. A suitable sample may be a magnetostrictive material or some other material having at least one side coated with a magnetostrictive material. When the sample is a suitable shape, i.e., a cube, rectangular parallelepiped, solid sphere or spherical shell, the elastic moduli or the material can be analytically determined from the measured resonance frequency spectrum. No mechanical transducers are required and the sample excitation is obtained without contact with the sample, leading to highly reproducible results and a measurement capability over a wide temperature range, e.g. from liquid nitrogen temperature to the Curie temperature of the magnetostrictive material.

Schwarz, Ricardo B. (Los Alamos, NM) [Los Alamos, NM; Kuokkala, Veli-Tapani (Tampere, FI) [Tampere, FI

1992-01-01

191

Resonances and inverse scattering  

NASA Astrophysics Data System (ADS)

Inverse scattering problems for Sturm-Liouville differential equations find numerous applications in physics, in particular, quantum mechanics. While the theory of these problems has been developed over a number of decades, a more recent concern has been the use of resonances, important phenomena in physics, as data---the inverse resonance problem. In this dissertation, we address this problem in a variety of cases. First, we investigate the full-line Schrodinger equation where the data for the inverse problem include the eigenvalues and resonances. We prove that any two potentials that have enough data points sufficiently close together must also be close in a suitable sense. We then prove a discrete analogue for a full-line Jacobi equation. Finally, we prove a uniqueness theorem for a left-definite, half-line Sturm-Liouville equation. Along the way, we improve upon the current inverse spectral and scattering theorems for this equation.

Bledsoe, Matthew B.

192

Magnetostrictive resonance excitation  

US Patent & Trademark Office Database

The resonance frequency spectrum of a magnetostrictive sample is remotely determined by exciting the magnetostrictive property with an oscillating magnetic field. The permeability of a magnetostrictive material and concomitant coupling with a detection coil varies with the strain in the material whereby resonance responses of the sample can be readily detected. A suitable sample may be a magnetostrictive material or some other material having at least one side coated with a magnetostrictive material. When the sample is a suitable shape, i.e., a cube, rectangular parallelepiped, solid sphere or spherical shell, the elastic moduli or the material can be analytically determined from the measured resonance frequency spectrum. No mechanical transducers are required and the sample excitation is obtained without contact with the sample, leading to highly reproducible results and a measurement capability over a wide temperature range, e.g. from liquid nitrogen temperature to the Curie temperature of the magnetostrictive material.

1992-09-29

193

Coupled Fano resonators.  

PubMed

We theoretically investigate coupled Fano structures which combine the characteristics of both directly coupled Fabry-Perot cavities (DCFPC) and a side-coupled integrated spaced sequence of resonators (SCISSOR). Asymmetric and symmetric Fano resonances in a single and doubly-coupled Fano unit are analytically derived based on Fabry-Perot approach. It is found that doubly-coupled Fano units show a special asymmetric EIT-like lineshape. This structure shows an index changing sensitivity of 10(-6), about two orders higher than that of the single Fano resonator, which is promising for index sensor application. A unique frequency detuning method of EIT like lineshape is also found in the doubly-coupled Fano units. The multiple coupled Fano unit structure demonstrates potentials for applications of tunable optical filter and slow light, whereas for the latter it shows much higher group delay than that of SCISSORS and DCFPC with the same parameters. PMID:20940775

Tu, Xiaoguang; Mario, Landobasa Y; Mei, Ting

2010-08-30

194

Coupled-Resonator-Induced Transparency  

NASA Technical Reports Server (NTRS)

We demonstrate that a cancellation of absorption occurs on resonance for two (or any even number of) coupled optical resonators, due to mode splitting and classical destructive interference, particularly when the resonator finesse is large and the loss in the resonator furthest from the excitation waveguide is small. The linewidth and group velocity of a collection of such coupled-resonator structures may be decreased by using larger resonators of equal size, using larger resonators of unequal size where the optical path length of the larger resonator is an integer multiple of that of the smaller one, or by using a larger number of resonators per structure. We explore the analogy between these effects and electromagnetically induced transparency in an atomic system.

Smith, David D.; Chang, Hong-Rok; Fuller, Kirk A.; Rosenberger, A. T.; Boyd, Robert W.

2003-01-01

195

Hexagonal quartz resonator  

DOEpatents

A generally flat, relatively thin AT-cut piezoelectric resonator element structured to minimize the force-frequency effect when mounted and energized in a housing. The resonator is in the form of an equilateral hexagon with the X crystallographic axis of the crystal passing through one set of opposing corners with mounting being effected at an adjacent set of corners respectively [+-]60[degree] away from the X axis which thereby results in a substantially zero frequency shift of the operating frequency. 3 figs.

Peters, R.D.M.

1982-11-02

196

(Resonance ionization spectroscopy)  

SciTech Connect

J. P. Young attended the Fifth International Symposium on Resonance Ionization Spectroscopy and presented an invited oral presentation on research he and coworkers had carried out in applying diode lasers to resonance ionization mass spectrometry. A summary of the conference is given along with an assessment of some of the presentations that the author found of interest. Young also visited Professor Marassi at the University of Camerino to present a seminar and discuss mutual interests in a new molten salt research project of the author. Some of the studies at Camerino are described. Ideas concerning the author's research that came from private discussions are also presented here.

Young, J.P.

1990-10-11

197

Method for resonant measurement  

DOEpatents

A method of measurement of objects to determine object flaws, Poisson`s ratio ({sigma}) and shear modulus ({mu}) is shown and described. First, the frequency for expected degenerate responses is determined for one or more input frequencies and then splitting of degenerate resonant modes are observed to identify the presence of flaws in the object. Poisson`s ratio and the shear modulus can be determined by identification of resonances dependent only on the shear modulus, and then using that shear modulus to find Poisson`s ratio using other modes dependent on both the shear modulus and Poisson`s ratio. 1 fig.

Rhodes, G.W.; Migliori, A.; Dixon, R.D.

1996-03-05

198

Field resonance propulsion concept  

NASA Technical Reports Server (NTRS)

A propulsion concept was developed based on a proposed resonance between coherent, pulsed electromagnetic wave forms, and gravitational wave forms (or space-time metrics). Using this concept a spacecraft propulsion system potentially capable of galactic and intergalactic travel without prohibitive travel times was designed. The propulsion system utilizes recent research associated with magnetic field line merging, hydromagnetic wave effects, free-electron lasers, laser generation of megagauss fields, and special structural and containment metals. The research required to determine potential, field resonance characteristics and to evaluate various aspects of the spacecraft propulsion design is described.

Holt, A. C.

1979-01-01

199

Method for resonant measurement  

DOEpatents

A method of measurement of objects to determine object flaws, Poisson's ratio (.sigma.) and shear modulus (.mu.) is shown and described. First, the frequency for expected degenerate responses is determined for one or more input frequencies and then splitting of degenerate resonant modes are observed to identify the presence of flaws in the object. Poisson's ratio and the shear modulus can be determined by identification of resonances dependent only on the shear modulus, and then using that shear modulus to find Poisson's ratio using other modes dependent on both the shear modulus and Poisson's ratio.

Rhodes, George W. (5201 Rio Grande Blvd., N.W., Albuquerque, NM 87107); Migliori, Albert (Rte. 4, Box 258 Tano Rd., Sante Fe, NM 87501); Dixon, Raymond D. (396 Connie Ave., White Rock, NM 87544)

1996-01-01

200

Resonant optical gun.  

PubMed

We propose a concept of a structure-a resonant optical gun-to realize an efficient propulsion of dielectric microparticles by light forces. The structure is based on a waveguide in which a reversal of the electromagnetic momentum flow of the incident mode is realized by exciting a whispering gallery resonance in the microparticle. The propelling force can reach the value up to the theoretical maximum of twice the momentum flow of the initial wave. The force density oscillates along the particle periphery and has very large amplitude. PMID:24784113

Maslov, A V; Bakunov, M I

2014-05-01

201

Dipole Coupling of a Double Quantum Dot to a Microwave Resonator  

NASA Astrophysics Data System (ADS)

We demonstrate the realization of a hybrid solid-state quantum device, in which a semiconductor double quantum dot is dipole coupled to the microwave field of a superconducting coplanar waveguide resonator. The double dot charge stability diagram extracted from measurements of the amplitude and phase of a microwave tone transmitted through the resonator is in good agreement with that obtained from transport measurements. Both the observed frequency shift and linewidth broadening of the resonator are explained considering the double dot as a charge qubit coupled with a strength of several tens of MHz to the resonator.

Frey, T.; Leek, P. J.; Beck, M.; Blais, A.; Ihn, T.; Ensslin, K.; Wallraff, A.

2012-01-01

202

Probing Studentsâ Understanding of Resonance  

NSDL National Science Digital Library

Resonant phenomena play a crucial role in magnetic resonance imaging (MRI), a widely used medical tool in today's society. The basic features of the resonance in MRI can be taught by looking at the resonance of a compass driven by an electromagnetic field. However, resonance in a oscillating magnetic field is not a phenomenon that is familiar to most students. Thus, as a precursor to creating instructional materials, we investigated how students applied their learning about resonance as traditionally taught to this novel system.

Murphy, Sytil K.; Mcbride, Dyan L.; Gross, Josh; Zollman, Dean A.

2010-01-19

203

Superconducting microwave resonator for millikelvin magnetic resonance force microscopy  

NASA Astrophysics Data System (ADS)

We have fabricated a superconducting resonator capable of generating a strong microwave magnetic field in a small (100 ?m) volume for low temperature magnetic resonance experiments. While the resonator was specifically developed for use at millikelvin temperatures in a dilution refrigerator, where the total cooling power is limited to a few hundred microwatts, it is also useful at temperatures up to 5 K. The resonator consists of a 220 ?m diameter, 2-1/2 turn niobium coil resonating with a short section of niobium microstripline. At a resonance frequency of 3 GHz, the loaded Q of the resonator was 780. The field strength was characterized by performing electron spin nutations. Operating at 100 mK with 320 ?W of dissipated power, the resonator generated a field of 4 G at a distance of 100 ?m from the coil.

Mamin, H. J.; Budakian, R.; Rugar, D.

2003-05-01

204

Dittany ( Origanum dictamnus) as a source of water-extractable antioxidants  

Microsoft Academic Search

Extracts of dittany (Origanum dictamnus L.) made with solvents of varying polarity were evaluated (i) by electron spin resonance (ESR) spectrometry using the spin trapping technique for their efficiencies as scavengers of free radicals, and (ii) by measurement of oxygen depletion in a methyl linoleate emulsion for their efficiencies as chain-breaking antioxidants. Aqueous extracts of dittany most efficiently scavenged hydroxyl

Jens K. S Møller; Helle Lindberg Madsen; Tuula Aaltonen; Leif H Skibsted

1999-01-01

205

Electron Beam Assisted Extraction of Highly Charged Ions from an ECRIS  

Microsoft Academic Search

A new concept to assist the extraction and to improve the quality of highly charged ion beams from an electron cyclotron resonance ion source (ECRIS) is the injection of an intense and well focused electron beam from the extraction side into the plasma of the ion source [1]. A first test setup and first results have been presented elsewhere [2].

S. Runkel; O. Hohn; L. Schmidt; K. E. Stiebing; H. Schmidt-Böcking; A. Schempp; R. Becker

1999-01-01

206

Extraction of zirconium(IV) from aqueous acid solutions by trioctylphosphine oxide  

SciTech Connect

The extraction of zirconium(IV) from aqueous solutions of hydrochloric, nitric and sulphuric acids by trioctylphosphine oxide (TOPO) in kerosene has been investigated under different conditions. The organic phases have been studied by infrared and nuclear magnetic resonance spectroscopies. The extraction equilibria are discussed in light of the results obtained. 7 figures, 2 tables.

Sato, T.

1983-01-01

207

Seismic Resonant Emission  

Microsoft Academic Search

There are several classes of underground objects which can produce resonant emission after being hit by incident seismic waves. Those objects include tunnels, pipes, buried containers, ground-filled excavations, unexploded ordinances, fluid-filled fractures, mine shafts, and the like. Being high contrast scatterers, these objects are capable of generating strong scattered waves where primary PP, PS, SS waves carry away most of

V. A. Korneev

2007-01-01

208

Double resonator cantilever accelerometer  

DOEpatents

A digital quartz accelerometer includes a pair of spaced double-ended tuning forks fastened at one end to a base and at the other end through a spacer mass. Transverse movement of the resonator members stresses one and compresses the other, providing a differential frequency output which is indicative of acceleration.

Koehler, D.R.

1982-09-23

209

Double resonator cantilever accelerometer  

DOEpatents

A digital quartz accelerometer includes a pair of spaced double-ended tuning forks fastened at one end to a base and at the other end through a spacer mass. Transverse movement of the resonator members stresses one and compresses the other, providing a differential frequency output which is indicative of acceleration.

Koehler, Dale R. (Albuquerque, NM)

1984-01-01

210

Magnetic Resonance Imaging (MRI)  

MedlinePLUS

What is an MRI? MRI stands for Magnetic Resonance Imaging. It is an important tool used in many fields of medicine, and is capable of generating a detailed image of any part of the human body. As an analogy, think about a loaf of bread. You can’t see inside the loaf, so how would you go about finding ...

211

Resonance Ionization, Mass Spectrometry.  

ERIC Educational Resources Information Center

Discussed is an analytical technique that uses photons from lasers to resonantly excite an electron from some initial state of a gaseous atom through various excited states of the atom or molecule. Described are the apparatus, some analytical applications, and the precision and accuracy of the technique. Lists 26 references. (CW)

Young, J. P.; And Others

1989-01-01

212

Cyclotron Resonance in Magnesium.  

National Technical Information Service (NTIS)

Azbel'-Kaner cyclotron resonance has been studied at 22.9 GHz and 2 degrees K in the (10(-1)0), (11(-2)0), (0001), and (10(-1)1) planes of magnesium. Fifteen distinct mass series have been identified and their mass values determined as a function of the o...

D. A. Zych T. G. Eck

1969-01-01

213

Fused microfiber resonators  

Microsoft Academic Search

We demonstrate a ~2.6 mm-diameter optical ring resonator fabricated from a 7.2 mum-thick silica fiber with a CO2 laser-fused coupling region for mechanical robustness. We experimentally obtain a Q-factor of ges25,000 at 1.55 mum.

Parama Pal; Wayne H. Knox

2009-01-01

214

Functional Magnetic Resonance Imaging  

ERIC Educational Resources Information Center

Functional magnetic resonance imaging (fMRI), with its excellent spatial resolution and ability to visualize networks of neuroanatomical structures involved in complex information processing, has become the dominant technique for the study of brain function and its development. The accessibility of in-vivo pediatric brain-imaging techniques…

Voos, Avery; Pelphrey, Kevin

2013-01-01

215

Width of nonlinear resonance  

SciTech Connect

Two approximations are made, one essential and the other not so essential but convenient to keep the analytical treatment manageable: (1) Only one nonlinear resonance is considered at a time so that the treatment is best suited when the tune is close to one resonance only. To improve this approximation, one must go to the next order which involves a canonical transformation of dynamical variables. Analytical treatment of more than one resonance is not possible for general cases. (2) In the formalism using the action-angle variables, the Hamiltonian can have terms which are independent of the angle variables. These terms are called phase-independent terms or shear terms. The tune is then a function of the oscillation amplitudes. In the lowest-order treatment, the (4N)-pole components but not the (4N + 2)-pole components contribute to this dependence. In deriving the resonance width analytically, one ignores these terms in the Hamiltonian for the sake of simplicity. If these are retained, one needs at least three extra parameters and the analytical treatment becomes rather unwieldy.

Ohnuma, S.

1984-03-01

216

Laser beams and resonators  

Microsoft Academic Search

This paper is a review of the theory of laser beams and resonators. It is meant to be tutorial in nature and useful in scope. No attempt is made to be exhaustive in the treatment. Rather, emphasis is placed on formulations and derivations which lead to basic understanding and on results which bear practical significance.

H. Kogelnik; T. Li

1966-01-01

217

High-Q bandpass resonators utilizing bandstop resonator pairs  

NASA Technical Reports Server (NTRS)

A high-Q bandpass resonators utilizing composite bandstop resonator pairs is reported. The bandstop resonator pairs are formed of composite series or parallel connected realizable transmission line elements. The elements are exclusively either quarter-wavelength lines or half-wavelength lines.

Okean, H. C. (inventor)

1973-01-01

218

Basics of Resonance Chiral Theory  

NASA Astrophysics Data System (ADS)

We review the main components that have to be considered, within Resonance Chiral Theory, in the study of processes whose dynamics is dominated by hadron resonances. We show its application in the study of the ?-->????? decay.

Portolés, J.

2010-12-01

219

Coherent synchro-betatron resonance  

SciTech Connect

Coherent synchro-betatron resonances can present a serious limit for low-energy synchrotrons with strong space charge. Here, an excitation of a dipole transverse mode is considered at resonance condition.

Burov, A.; Lebedev, V.; /Fermilab

2006-12-01

220

Microwave Open Resonators for Gyrotrons.  

National Technical Information Service (NTIS)

Weakly irregular waveguides which, under appropriate conditions, can be considered as open resonators are studied. Through the analysis of a variety of resonators, the influence of the cavity geometry on the longitudinal electric field distribution is dis...

J. J. Barroso, A. Montes

1986-01-01

221

Infrared cubic dielectric resonator metamaterial.  

SciTech Connect

Dielectric resonators are an effective means to realize isotropic, low-loss optical metamaterials. As proof of this concept, a cubic resonator is analytically designed and then tested in the long-wave infrared.

Sinclair, Michael B.; Brener, Igal; Peters, David William; Ginn, James Cleveland, III; Ten Eyck, Gregory A.

2010-06-01

222

Resonance lidar detection of the mesospheric nickel layer  

NASA Astrophysics Data System (ADS)

We present the first reported detection of the mesospheric nickel (Ni) layer with resonance lidar. Ni is abundant in meteorites, the source of the metal layers, but has not been previously detected in the mesosphere. We detail the wavelength search we used to find the Ni absorption line and the SNR technique we used to extract the low resonance signal. Simulation results based on measurements of sodium (Na) with our system show that the signals received are as expected. We present an initial estimate of the Ni layer density and spatial parameters and find that the Ni layer characteristics are similar to those of the sodium layer.

Martus, C. M.; Collins, R. L.

2013-12-01

223

Electromagnetic excitation of the Delta(1232) resonance  

SciTech Connect

We review the description of the lowest-energy nucleon excitation--the Delta(1232)-resonance. Much of the recent effort has been focused on the precision measurements of the nucleon to Delta transition by means of electromagnetic probes. We review the results of those measurements and confront them with the state-of-the-art calculations based on chiral effective-field theories (EFT), lattice QCD, and QCD-inspired models. Some of the theoretical approaches are reviewed in detail. In particular, we describe the chiral EFT of QCD in the energy domain of the Delta-resonance, and its applications to the electromagnetic nucleon-to-Delta transition (gamma N Delta). We also describe the recent dynamical and unitary-isobar models of pion electroproduction which are extensively used in the extraction of the gamma* N Delta form factors from experiment. Furthermore, we discuss the link of the gamma* N Delta form factors to generalized parton distributions (GPDs), as well as the predictions of perturbative QCD for these transition form factors. The present status of understanding the Delta-resonance properties and the nature of its excitation is summarized.

V. Pascalutsa; M. Vanderhaeghen; Shin Nan Yang

2006-09-05

224

Continuous-wave intra-cavity singly resonant optical parametric oscillator with resonant wave output coupling.  

PubMed

We report herein the enhancement in both power and efficiency performance of a continuous-wave intra-cavity singly resonant optical parametric oscillator (ICSRO) by introducing finite resonant wave output coupling. While coupling out the resonant wave to useful output, the output coupling increases the SRO threshold properly thus suppresses the back-conversion under high pump power. Therefore, the down-conversion efficiency is maintained under high pump without having to raise the threshold by defocusing. With a T = 9.6% signal wave output coupler used, the SRO threshold is 2.46 W and the down-conversion efficiency is 72.9% under the maximum pump power of 21.4 W. 1.43 W idler power at 3.66 ?m and 5.03 W signal power at 1.5 ?m are obtained, corresponding to a total extraction efficiency of 30.2%. The resonant wave out coupling significantly levels up the upper limit for the power range where the ICSRO exhibits high efficiency, without impeding its advantage of low threshold. PMID:23262741

Sheng, Quan; Ding, Xin; Shang, Ce; Li, Bin; Fan, Chen; Zhang, Haiyong; Yu, Xuanyi; Wen, Wuqi; Ma, Yila; Yao, Jianquan

2012-12-01

225

Spatial Solitons In Nonlinear Resonators  

Microsoft Academic Search

\\u000a We discuss solitons in nonlinear resonators. In particular we discuss the cases of “laser” resonator, laser resonator containing\\u000a a nonlinear absorber, parametric mixing and semiconductor microresonator. In these resonators the following localized structures\\u000a (or spatial solitons) exist: vortices, bright solitons, phase solitons, and bright and dark solitons, respectively. We discuss\\u000a the types of equations to which these systems correspond and

C. O. Weiss; V. B. Taranenko; M. Vaupel; K. Staliunas; G. Slekys; M. F. H. Tarroja

226

Microwave Resonators Containing Diamond Disks  

NASA Technical Reports Server (NTRS)

Synthetic diamond dielectric bodies proposed for use in cylindrical resonators helping to stabilize frequencies of some microwave oscillators. Acting in conjunction with metal resonator cavities in which mounted, such dielectric bodies support "whispering-gallery" waveguide modes characterized by desired frequencies of resonance and by electro-magnetic-field configurations limiting dissipation of power on metal surfaces outside dielectric bodies. Performances at room temperature might exceed those of liquid-nitrogen-cooled sapphire-based resonators.

Dick, G. John; Maleki, Lutfollah; Wang, Rabi T.

1996-01-01

227

The use of nested sampling in the extraction of polarisation observables at CLAS  

SciTech Connect

The extraction of polarisation observables from photoproduction experiments provides an insight into the spectrum of nucleon resonances and the 'missing resonance' problem. Experiments carried out at JLab, Mainz and Bonn cover a wide range of reactions, which will soon result in the first 'complete measurement' in pseudoscalar meson photoproduction. Traditionally, these measurements have been analysed using frequentist statistics, where parameters are extracted by fitting distributions. An alternative method is the application of Bayesian statistics, where any existing knowledge about the results can be used in the initial conditions. One such application of this is nested sampling. This work discusses nested sampling and how it can be applied to the extraction of spin observables.

Stefanie Lewis

2012-09-01

228

On the complex resonant frequency of open dielectric resonators  

NASA Astrophysics Data System (ADS)

An analytical method is presented for calculating accurately the complex resonant frequency of dielectric pillbox resonators. In this method, an approximted field of the resonator is expanded into a truncated series of solutions of the Helmholtz equation in the spherical coordinates, and the boundary condition on the resonator surface is treated in the least-squares sense. The resonant frequency and the intrinsic Q value due to radiation loss are obtained in the form of approximation converging to the exact values. Numerical results are compared with previously published calculations, which show that the present method is a relatively simple and effective one.

Tsuji, M.; Shigesawa, H.; Takiyama, K.

1983-05-01

229

Quantum Phase Extraction in Isospectral Electronic Nanostructures  

SciTech Connect

Quantum phase is not a direct observable and is usually determined by interferometric methods. We present a method to map complete electron wave functions, including internal quantum phase information, from measured single-state probability densities. We harness the mathematical discovery of drum-like manifolds bearing different shapes but identical resonances, and construct quantum isospectral nanostructures possessing matching electronic structure but divergent physical structure. Quantum measurement (scanning tunneling microscopy) of these 'quantum drums' [degenerate two-dimensional electron states on the Cu(111) surface confined by individually positioned CO molecules] reveals that isospectrality provides an extra topological degree of freedom enabling robust quantum state transplantation and phase extraction.

Moon, Christopher

2010-04-28

230

Lumped Mode Microwave Resonant Structures  

Microsoft Academic Search

A new class of electrically small microwave resonators working in lumped mode is described for filter and oscillator applications. These resonators are tunable over a wide range and have a Q of about 2000. Tuning, coupling, and applications of these resonant structures are discussed.

M. Mehdizadeh; T. K. Ishii; J. S. Hyde; W. Froncisz

1983-01-01

231

Noise in microelectromechanical system resonators  

Microsoft Academic Search

Microelectromechanical system (MEMS) and nanoelectromechanical system (NEMS) based resonators and filters, ranging in frequencies from kHz to GHz, have been proposed. The question of how the stabilities of such resonators scale with dimensions is examined in this paper, with emphasis on the noise characteristics. When the dimensions of a resonator become small, instabilities that are negligible in macro-scale devices become

John R. Vig; Yoonkee Kim

1999-01-01

232

Dualband Split Dielectric Resonator Antenna  

Microsoft Academic Search

A dualband dielectric resonator antenna (DRA) is designed by splitting a rectilinear dielectric resonator (DR) and carving notches off the DR. It is observed that notches engraved at different positions affect different modes. Removal of dielectric material from where the electric field is strong incurs a significant increase in resonant frequency. The abrupt change of normal electric field across the

Tze-Hsuan Chang; Jean-Fu Kiang

2007-01-01

233

Repetitive resonant railgun power supply  

DOEpatents

A repetitive resonant railgun power supply provides energy for repetitively propelling projectiles from a pair of parallel rails. The supply comprises an energy storage capacitor, a storage inductor to form a resonant circuit with the energy storage capacitor and a magnetic switch to transfer energy between the resonant circuit and the pair of parallel rails for the propelling of projectiles.

Honig, Emanuel M. (Los Alamos, NM); Nunnally, William C. (Los Alamos, NM)

1988-01-01

234

Extensive Screening for Edible Herbal Extracts with Potent Scavenging Activity against Superoxide Anions  

Microsoft Academic Search

To search for edible herbal extracts with potent antioxidant activity, we conducted a large scale screening based on the superoxide\\u000a scavenging activity. That is, scavenging activity against superoxide anions were extensively screened from ethanol extracts\\u000a of approximately 1,000 kinds of herbs by applying an electron spin resonance (ESR)-spin trapping method. Among them we chose\\u000a four edible herbal extracts with prominently

Keita Saito; Masahiro Kohno; Fumihiko Yoshizaki; Yoshimi Niwano

2008-01-01

235

On the resonances and polarizabilities of split ring resonators  

NASA Astrophysics Data System (ADS)

In this paper, the behavior at resonance of split ring resonators (SRRs) and other related topologies, such as the nonbianisotropic SRR and the broadside-coupled SRR, are studied. It is shown that these structures exhibit a fundamental resonant mode (the quasistatic resonance) and other higher-order modes which are related to dynamic processes. The excitation of these modes by means of a properly polarized time varying magnetic and/or electric fields is discussed on the basis of resonator symmetries. To verify the electromagnetic properties of these resonators, simulations based on resonance excitation by nonuniform and uniform external fields have been performed. Inspection of the currents at resonances, inferred from particle symmetries and full-wave electromagnetic simulations, allows us to predict the first-order dipolar moments induced at the different resonators and to develop a classification of the resonances based on this concept. The experimental data, obtained in SRR-loaded waveguides, are in agreement with the theory and point out the rich phenomenology associated with these planar resonant structures.

García-García, J.; Martín, F.; Baena, J. D.; Marqués, R.; Jelinek, L.

2005-08-01

236

Free radical scavenging activity of red ginseng aqueous extracts.  

PubMed

This study was performed to investigate the free radical scavenging activity of Panax red ginseng C.A. Meyer aqueous extract on 1,1-dipheny-2-picrylhydrazyl (DPPH), carbon-centered radical, hydroxyl and superoxide radicals using Electron Spin Resonance (ESR) spectrometer and spin-trapping techniques. Two different Red ginseng aqueous extracts prepared by boiling water or room temperature extraction exhibited no significant difference in free radical scavenging activity. Ginseng extracts completely eliminated DPPH radical at 2 mg/ml. About 0.5 mg/ml ginseng extracts quenched 80% carbon-centered free radicals generated from 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH). Hydroxyl radical and superoxide radical were generated by UV irradiation and trapped by 5,5-dimethyl-l-pyrroline-N oxide (DMPO). Ginseng extracts scavenged 40% of hydroxyl radical at 0.1 mg/ml. Two mg/ml ginseng extracts completely scavenged superoxide radical. Ginseng extracts did not scavenge nitric oxide. The ESR data demonstrate that red ginseng aqueous extract is not a strong free radical scavenger. PMID:11882354

Kim, Yoo K; Guo, Qiong; Packer, Lester

2002-03-20

237

Probing thermal expansion of graphene and modal dispersion at low-temperature using graphene nanoelectromechanical systems resonators  

Microsoft Academic Search

We use suspended graphene electromechanical resonators to study the variation of resonant frequency as a function of temperature. Measuring the change in frequency resulting from a change in tension, from 300 to 30 K, allows us to extract information about the thermal expansion of monolayer graphene as a function of temperature, which is critical for strain engineering applications. We find

Vibhor Singh; Shamashis Sengupta; Hari S. Solanki; Rohan Dhall; Adrien Allain; Sajal Dhara; Prita Pant; Mandar M. Deshmukh

2010-01-01

238

Measuring thermal expansion of graphene and understanding modal dispersion at low-temperature using graphene NEMS resonators  

Microsoft Academic Search

We use suspended graphene electromechanical resonators to study the evolution of resonant frequency as a function of temperature. Measuring the change in frequency resulting from a change in tension, from 300K to 30K, allows us to extract information about the thermal expansion of monolayer graphene as a function of temperature, which is critical for strain engineering applications. We find that

Mandar Deshmukh; Vibhor Singh; Shamashis Sengupta; Hari S. Solanki; Rohan Dhall; Adrien Allain; Sajal Dhara; Prita Pant

2010-01-01

239

Automatic breast border extraction  

Microsoft Academic Search

In computer aided mammography algorithms there are several processing steps, which must be performed. The basic segmentation procedure involves extracting the principal feature on a mammogram; the breast border. This is performed by segmenting the breast and the non-breast into distinct regions. In this paper, a method for extracting the breast border is proposed. The method has performance similar to

Christina M. Olsen

2005-01-01

240

Onion DNA Extraction  

NSDL National Science Digital Library

This laboratory exercise is designed to show learners how DNA can easily be extracted from onion cells using simple materials. Use this experiment to supplement any unit on genetics and to demonstrate how scientists study DNA. Adult supervision is recommended. This resource guide includes tips and suggestions for instructors as well as other DNA extraction experiments and a chart for learners to answer questions.

Hays, Lana

2009-01-01

241

Resonant Dark Matter  

SciTech Connect

It is usually assumed that dark matter direct detection is sensitive to a large fraction of the dark matter (DM) velocity distribution. We propose an alternative form of dark matter-nucleus scattering which only probes a narrow range of DM velocities due to the existence of a resonance, a DM-nucleus bound state, in the scattering - resonant dark matter (rDM). The scattering cross section becomes highly element dependent, has increased modulation and as a result can explain the DAMA/LIBRA results whilst not being in conflict with other direct detection experiments. We describe a simple model that realizes the dynamics of rDM, where the DM is the neutral component of a fermionic weak triplet whose charged partners differ in mass by approximately 10 MeV.

Bai, Yang; Fox, Patrick J.; /Fermilab

2009-09-01

242

Resonant dark matter  

NASA Astrophysics Data System (ADS)

It is usually assumed that dark matter direct detection is sensitive to a large fraction of the dark matter (DM) velocity distribution. We propose an alternative form of dark matter-nucleus scattering which only probes a narrow range of DM velocities due to the existence of a resonance, a DM-nucleus bound state, in the scattering - resonant dark matter (rDM). The scattering cross section becomes highly element dependent, has increased modulation and as a result can explain the DAMA/LIBRA results whilst not being in conflict with other direct detection experiments. We describe a simple model that realizes the dynamics of rDM, where the DM is the neutral component of a fermionic weak triplet whose charged partners differ in mass by approximately 10 MeV.

Bai, Yang; Fox, Patrick J.

2009-11-01

243

Resonance enhanced turbulent transport  

SciTech Connect

The effect of oscillatory shear flows on turbulent transport of passive scalar fields is studied by numerical computations based on the results provided by E. Kim [Physics of Plasmas 13, 022308 (2006)]. Turbulent diffusion is found to depend crucially on the competition between suppression due to shearing and enhancement due to resonances, depending on the characteristic time and length scales of shear flow and turbulence. Enhancements in transport occur for turbulence with finite memory time either due to Doppler or parametric resonances. Scalings of turbulence amplitude and transport are provided in different parameter spaces. The results suggest that oscillatory shear flows are not only less efficient in regulating turbulence, but also can enhance the value of turbulent diffusion, accelerating turbulent transport.

Newton, Andrew P. L.; Kim, Eun-jin [Department of Applied Mathematics, University of Sheffield, Sheffield, S3 7RH (United Kingdom)

2007-12-15

244

Energetics of stochastic resonance.  

PubMed

In this paper, we discuss the motion of a Brownian particle in a double-well potential driven by a periodic force in terms of energies delivered by the periodic and the noise forces and energy dissipated into the viscous environment. It is shown that, while the power delivered by the periodic force to the Brownian particle is controlled by the strength of the noise, the power delivered by the noise itself is independent of the amplitude and frequency of the periodic force. The implications of this result for the mechanism of stochastic resonance in an equilibrium system is that it is not energy from the noise force which enhances a small periodic force, but rather an increase of energy delivered by the periodic force, regulated by the strength of the noise. We further re-evaluate the frequency dependence of stochastic resonance in terms of energetic terms including efficiency. PMID:22225390

Jung, Peter; Marchesoni, Fabio

2011-12-01

245

Photorefractivity in WGM resonators  

NASA Technical Reports Server (NTRS)

We report on observation of photorefractive effects in whispering gallery mode resonators made of as-grown and magnesium doped lithium niobate and lithium tantalate in the near as well as far infrared. The effects manifested themselves as dynamic modification of the spectra as well as quality factors of the resonators coupled to the laser radiation. We have observed a significant (exceeding 10-4) change of the ordinary index of refraction of all the materials exposed with 780 nm light. Photorefractive effects have also been detected at 1550 nm. Our experiments support the conclusion that the photorefractivity does not have a distinct red boundary. We show that the maximum saturated refractive index change in the infrared is of the same order of magnitude as in the visible light.

Matsko, Andrey; Savchenkov, Anatoliy; Strekalov, Dmitry; Ilchenko, Vladimir; Maleki, Lute

2006-01-01

246

Magnetic Resonance Fingerprinting  

PubMed Central

Summary Magnetic Resonance (MR) is an exceptionally powerful and versatile measurement technique. The basic structure of an MR experiment has remained nearly constant for almost 50 years. Here we introduce a novel paradigm, Magnetic Resonance Fingerprinting (MRF) that permits the non-invasive quantification of multiple important properties of a material or tissue simultaneously through a new approach to data acquisition, post-processing and visualization. MRF provides a new mechanism to quantitatively detect and analyze complex changes that can represent physical alterations of a substance or early indicators of disease. MRF can also be used to specifically identify the presence of a target material or tissue, which will increase the sensitivity, specificity, and speed of an MR study, and potentially lead to new diagnostic testing methodologies. When paired with an appropriate pattern recognition algorithm, MRF inherently suppresses measurement errors and thus can improve accuracy compared to previous approaches.

Ma, Dan; Gulani, Vikas; Seiberlich, Nicole; Liu, Kecheng; Sunshine, Jeffrey L.; Duerk, Jeffrey L.; Griswold, Mark A.

2013-01-01

247

Resonant Cascaded Downconversion  

SciTech Connect

We analyze an optical parametric oscillator (OPO) in which cascaded down-conversion occurs inside a cavity resonant for all modes but the initial pump. Due to the resonant cascade design, the OPO presents two {chi}{sup (2)}-level oscillation thresholds that are therefore much lower than for a {chi}{sup (3)} OPO. This is promising for reaching the regime of an effective third-order nonlinearity well above both thresholds. Such a {chi}{sup (2)} cascaded device also has potential applications in frequency conversion to far-infrared regimes. But, most importantly, it can generate novel multipartite quantum correlations in the output radiation, which represent a step beyond squeezed or entangled light. The output can be highly non-Gaussian and therefore not describable by any semiclassical model. In this paper, we derive quantum stochastic equations in the positive-P representation and undertake an analysis of steady-state and dynamical properties of this system.

Weedbrook, Christian [University of Toronto; Parrett, Ben [University of Queensland, The, Brisbane, Queensland, Australia; Kheruntsyan, Karen [University of Queensland, The, Brisbane, Queensland, Australia; Drummond, Peter [Centre for Atom Optics and Ultrafast Spectroscopy, Swinburne University of Technology, Melbourne; Pooser, Raphael C [ORNL; Pfister, Olivier [University of Virginia

2012-01-01

248

Unstable resonator with high magnification and low output coupling  

NASA Astrophysics Data System (ADS)

The application of standard unstable resonators does not allow for an independent adjustment of the resonator magnification and the output coupling. Either you get a high magnification together with a high output coupling, or vice versa. Certain laser types, like e.g. thin-disc lasers or chemical oxygen iodine lasers, permit only quite low optimum output couplings. The corresponding low resonator magnification is equal to a poor beam quality. In order to apply unstable resonators with a high magnification also to low gain media an additional mirror surface retroreflects a part of the out coupled radiation back into the cavity. The output coupling is reduced efficiently, whereas the resonator magnification stays high. Accordingly low gain media can be operated with high power extraction in combination with a good beam quality. Numerical and experimental investigations are shown. The experiments are performed with a chemical oxygen iodine laser operating at a wavelength of 1.315 ?m and demonstrate the feasibility of this resonator design.

Pargmann, Carsten; Hall, Thomas; Duschek, Frank; Grünewald, Karin M.; Handke, Jürgen

2012-02-01

249

Aberration correction of unstable resonators  

NASA Astrophysics Data System (ADS)

Construction of aspheric reflectors for unstable resonator lasers to provide an arbitrary laser mode inside the resonator to correct aberrations of an output beam by the construction of the shape of an end reflector opposite the output reflector of the resonator cavity, such as aberrations resulting from refraction of a beam exiting the solid of the resonator having an index of refraction greater than 1 or to produce an aberration in the output beam that will precisely compensate for the aberration of an optical train into which the resonator beam is coupled.

Lang, Robert J.

1994-10-01

250

Aberration correction of unstable resonators  

NASA Astrophysics Data System (ADS)

Construction of aspheric reflectors for unstable resonator lasers to provide an arbitrary laser mode inside the resonator to correct aberrations of an output beam by the construction of the shape of an end reflector opposite the output reflector of the resonator cavity, such as aberrations resulting from refraction of a beam exiting the solid of the resonator having an index of refraction greater than 1 or to produce an aberration in the output beam that will precisely compensate for the aberration of an optical train into which the resonator beam is coupled, is described.

Lang, Robert J.

1993-02-01

251

Aberration correction of unstable resonators  

NASA Technical Reports Server (NTRS)

Construction of aspheric reflectors for unstable resonator lasers to provide an arbitrary laser mode inside the resonator to correct aberrations of an output beam by the construction of the shape of an end reflector opposite the output reflector of the resonator cavity, such as aberrations resulting from refraction of a beam exiting the solid of the resonator having an index of refraction greater than 1 or to produce an aberration in the output beam that will precisely compensate for the aberration of an optical train into which the resonator beam is coupled.

Lang, Robert J. (inventor)

1994-01-01

252

Ohmic effects in quasioptical resonators  

SciTech Connect

Several properties of the Fabry-Perot-type open resonator used in the quasioptical gyrotron (QOG) and the quasioptical induced resonance electron cyclotron (IREC) maser are derived. The electric fields of the normal modes are given for the general case of the resonator axis tilted with respect to the direction perpendicular to the electron beam axis. The ohmic quality factor and the power dissipated in the mirrors are derived, as is the energy stored in the resonator. The time dependence of the mirror heating, relevant for pulsed experiments, is also derived. The formulae are applied to an example of current relevance, the quasioptical IREC maser resonator.

Hargreaves, T.A.; Fischer, R.P.; McCowan, R.B.; Fliflet, A.W. (Naval Research Lab., Washington, DC (United States))

1991-01-01

253

Stochastic resonance without tuning  

Microsoft Academic Search

STOCHASTIC resonance1á¤-4 (SR) is a phenomenon wherein the response of a nonlinear system to a weak periodic input signal is optimized by the presence of a particular, non-zero level of noise5 á¤-7. SR has been proposed as a means for improving signal detection in a wide variety of systems, including superconducting quantum interference devices8, and may be used in some

J. J. Collins; Carson C. Chow; Thomas T. Imhoff

1995-01-01

254

Tandem resonator reflectance modulator  

DOEpatents

A wide band optical modulator is grown on a substrate as tandem Fabry-Perot resonators including three mirrors spaced by two cavities. The absorption of one cavity is changed relative to the absorption of the other cavity by an applied electric field, to cause a change in total reflected light, as light reflecting from the outer mirrors is in phase and light reflecting from the inner mirror is out of phase with light from the outer mirrors.

Fritz, Ian J. (Albuquerque, NM); Wendt, Joel R. (Albuquerque, NM)

1994-01-01

255

Tandem resonator reflectance modulator  

DOEpatents

A wide band optical modulator is grown on a substrate as tandem Fabry-Perot resonators including three mirrors spaced by two cavities. The absorption of one cavity is changed relative to the absorption of the other cavity by an applied electric field, to cause a change in total reflected light, as light reflecting from the outer mirrors is in phase and light reflecting from the inner mirror is out of phase with light from the outer mirrors. 8 figs.

Fritz, I.J.; Wendt, J.R.

1994-09-06

256

Ultraminiature resonator accelerometer  

SciTech Connect

A new family of microminiature sensors and clocks is being developed with widespread application potential for missile and weapons applications, as biomedical sensors, as vehicle status monitors, and as high-volume animal identification and health sensors. To satisfy fundamental technology development needs, a micromachined clock and an accelerometer have initially been undertaken as development projects. A thickness-mode quartz resonator housed in a micromachined silicon package is used as the frequency-modulated basic component of the sensor family. Resonator design philosophy follows trapped energy principles and temperature compensation methodology through crystal orientation control, with operation in the 20--100 MHz range, corresponding to quartz wafer thicknesses in the 75--15 micron range. High-volume batch-processing manufacturing is utilized, with package and resonator assembly at the wafer level. Chemical etching of quartz, as well as micromachining of silicon, achieves the surface and volume mechanical features necessary to fashion the resonating element and the mating package. Integration of the associated oscillator and signal analysis circuitry into the silicon package is inherent to the realization of a size reduction requirement. A low temperature In and In/Sn bonding technology allows assembly of the dissimilar quartz and silicon materials, an otherwise challenging task. Unique design features include robust vibration and shock performance, capacitance sensing with micromachined diaphragms, circuit integration, capacitance-to-frequency transduction, and extremely small dimensioning. Accelerometer sensitivities were measured in the 1--3 ppm/g range for the milligram proof-mass structures employed in the prototypes evaluated to date.

Koehler, D.R.; Kravitz, S.H.; Vianco, P.T.

1996-04-01

257

Wireless ferroelectric resonating sensor.  

PubMed

This paper presents a passive wireless resonating sensor that is based on a ferroelectric varactor. The sensor replies with its data at an intermodulation frequency when a reader device illuminates it at 2 closely located frequencies. The paper derives a theoretical equation for the response of such a sensor, verifies the theory by simulations, and demonstrates a temperature sensor based on a ferroelectric varactor. PMID:20378440

Viikari, Ville; Seppa, Heikki; Mattila, Tomi; Alastalo, Ari

2010-04-01

258

Remarks on stochastic resonance  

Microsoft Academic Search

A recent and interesting experimental paper [B. McNamara, K. Wiesenfeld, and R. Roy, Phys. Rev. Lett. 60, 2626 (1988)] has refocused attention on the problem of stochastic resonance by presenting measurements of the singal-to-noise ratio (SNR) of a noise driven, periodically modulated bistable ring laser. We point out that the theoretical SNR, as defined in this and a previous work,

G. Debnath; T. Zhou; Frank Moss

1989-01-01

259

Search for resonant $\\\\widetilde\\\  

Microsoft Academic Search

Searches for resonant ~nu production in e+e collisions under the assumption that R-parity is not conserved and that the dominant R-parity violating coupling is lambda121 or lambda131 used data recorded by DELPHI in 1997 to 2000 at centre-of-mass energies of 183 to 208 GeV. No deviation from the Standard Model was obs erved. Upper limits are given for the lambda121

J Abdallah; P Abreu; W Adam; P Adzic; T Albrecht; T Alderweireld; R Alemany-Fernandez; T Allmendinger; P P Allport; Ugo Amaldi; N Amapane; S Amato; E Anashkin; A Andreazza; S Andringa; N Anjos; P Antilogus; W D Apel; Y Arnoud; S Ask; B Åsman; J E Augustin; A Augustinus; Paul Baillon; A Ballestrero; P Bambade; R Barbier; Dimitri Yuri Bardin; G Barker; A Baroncelli; Marco Battaglia; M Baubillier; K H Becks; M Begalli; A Behrmann; E Ben-Haim; N C Benekos; Alberto C Benvenuti; C Bérat; M Berggren; L Berntzon; D Bertrand; M Besançon; N Besson; D Bloch; M Blom; M Bluj; M Bonesini; M Boonekamp; P S L Booth; G Borisov; O Botner; B Bouquet; T J V Bowcock; I Boyko; M Bracko; R Brenner; E Brodet; P Brückman; J M Brunet; L Bugge; P Buschmann; M Calvi; T Camporesi; V Canale; F Carena; N Castro; F R Cavallo; M M Chapkin; P Charpentier; P Checchia; R Chierici; P Shlyapnikov; J Chudoba; S U Chung; K Cieslik; P Collins; R Contri; G Cosme; F Cossutti; M J Costa; B Crawley; D J Crennell; J Cuevas-Maestro; J D'Hondt; J Dalmau; T Da Silva; W Da Silva; G Della Ricca; A De Angelis; Wim de Boer; C De Clercq; B De Lotto; N De Maria; A De Min; L S De Paula; Lucia Di Ciaccio; A Di Simone; K Doroba; J Drees; M Dris; G Eigen; T J C Ekelöf; M Ellert; M Elsing; M C Espirito-Santo; G K Fanourakis; D Fassouliotis; Michael Feindt; J Fernández; A Ferrer; F Ferro; U Flagmeyer; H Föth; E Fokitis; F Fulda-Quenzer; J A Fuster; M Gandelman; C García; P Gavillet; E N Gazis; T Geralis; R Gokieli; B Golob; G Gómez-Ceballos; P Gonçalves; E Graziani; G Grosdidier; K Grzelak; J Guy; C Haag; A Hallgren; K Hamacher; J Hansen; S Haug; F Hauler; V Hedberg; M Hennecke; H Herr; J Hoffman; S O Holmgren; P J Holt; M A Houlden; K Hultqvist; J N Jackson; G Jarlskog; P Jarry; D Jeans; E K Johansson; P D Johansson; P Jonsson; C Joram; L Jungermann; F Kapusta; S Katsanevas; E C Katsoufis; Borut P Kersevan; A P Kiiskinen; B T King; N J Kjaer; P Kluit; P Kokkinias; C Kourkoumelis; O Kuznetsov; Z Krumshtein; M Kucharczyk; J Lamsa; G Leder; F Ledroit; L Leinonen; R Leitner; J Lemonne; V Lepeltier; T Lesiak; W Liebig; D Liko; A Lipniacka; J H Lopes; J M López; D Loukas; P Lutz; L Lyons; J MacNaughton; A Malek; S Maltezos; F Mandl; J Marco; R Marco; B Maréchal; M Margoni; J C Marin; C Mariotti; A Markou; C Martínez-Rivero; J Masik; N Mastroyiannopoulos; F Matorras; C Matteuzzi; F Mazzucato; M Mazzucato; R McNulty; C Meroni; W T Meyer; E Migliore; W A Mitaroff; U Mjörnmark; T Moa; M Moch; K Mönig; R Monge; J Montenegro; D Moraes; S Moreno; P Morettini; U Müller; K Münich; M Mulders; L M Mundim; W Murray; B Muryn; Gerald Myatt; T Myklebust; M Nassiakou; Francesco Luigi Navarria; K Nawrocki; R Nicolaidou; M Nikolenko; A Oblakowska-Mucha; V F Obraztsov; A G Olshevskii; A Onofre; Risto Orava; K Österberg; A Ouraou; A Oyanguren; M Paganoni; S Paiano; J P Palacios; H Palka; T D Papadopoulou; L Pape; C Parkes; F Parodi; U Parzefall; A Passeri; O Passon; L Peralta; V F Perepelitsa; A Perrotta; A Petrolini; J Piedra; L Pieri; F Pierre; M Pimenta; E Piotto; T Podobnik; V Poireau; M E Pol; G Polok; P Poropat; V Pozdnyakov; N Pukhaeva; Antonio Pullia; J Rames; L Ramler; A Read; P Rebecchi; J Rehn; D Reid; R Reinhardt; P B Renton; F Richard; J Rídky; M Rivero; D Rodríguez; A Romero; P Ronchese; E I Rosenberg; Patrick Roudeau; T Rovelli; V Ruhlmann-Kleider; D Ryabtchikov; A Sadovskii; L Salmi; J Salt; A Savoy-Navarro; U Schwickerath; A Segar; R L Sekulin; M Siebel; A N Sissakian; G Smadja; O G Smirnova; A Sokolov; A Sopczak; R Sosnowski; Tz Spassoff; M Stanitzki; A Stocchi; J Strauss; B Stugu; M Szczekowski; M Szeptycka; T Szumlak; T Tabarelli de Fatis; A C Taffard; F Tegenfeldt; J Timmermans; L G Tkatchev; M Tobin; S Todorovova; A G Tomaradze; B Tomé; A Tonazzo; P Tortosa; P Travnicek; D Treille; G Tristram; M Trochimczuk; C Troncon; M L Turluer; I A Tyapkin; P Tyapkin; S Tzamarias; V Uvarov; G Valenti; P van Dam; J Van Eldik; A Van Lysebetten; N Van Remortel; I B Van Vulpen; G Vegni; F Veloso; W A Venus; F Verbeure; P Verdier; V Verzi; D Vilanova; L Vitale; V Vrba; H Wahlen; A J Washbrook; C Weiser; D Wicke; J H Wickens; G Wilkinson; M Winter; M Witek; O P Yushchenko; A Zalewska-Bak; Piotr Zalewski; D Zavrtanik; N I Zimin; A I Zinchenko; M Zupan

2002-01-01

260

Double resonant quadrature birdcage.  

PubMed

The combined acquisition of proton images and localized spectra is considered essential to the application of NMR techniques to human and animal research. The ideal imaging/spectroscopy coil for our purposes would be one that provides the highest possible signal-to-noise, high homogeneity, and operation on two or more frequencies without retuning requirements or cable changes. To address these needs we have developed a quadrature double-tuned birdcage. We have incorporated our earlier work on the transformer coupled double-tuned surface coil into the birdcage structure by placing two birdcages in a coaxial configuration. This structure resonates at 34.6 MHz (phosphorus resonance at 2.0 T) and 85.5 MHz (proton resonance at 2.0 T). The quadrature performance of this coil for phosphorus was excellent, with a signal-to-noise that was 133% of our linear reference. The proton performance was less efficient, with a signal to noise that was 67% of our linear reference, but still quite sufficient for imaging. A phosphorus spectra and proton image of a rat abdomen are shown. PMID:8396709

Fitzsimmons, J R; Beck, B L; Brooker, H R

1993-07-01

261

A resonant wave theory  

NASA Astrophysics Data System (ADS)

It is shown that a solution of non-linear partial differential equations, including the Navier-Stokes equations can be computed in terms of wave-like series, which are referred to as waves below. The mean flow is a wave of infinitely long wavelength and period, laminar flows contain only one wave, i.e., the mean flow. With a supercritical instability, there are a mean flow, a dominant wave and its harmonics. For turbulence, there are many non-linearly interacting waves. Under this scenario, the amplitude of waves is determined by linear and non-linear terms. The linear case is the target of flow-instability studies and is the well known superposition principle for linear differential equations. The nonlinear case involves energy transfer among the waves satisfying resonance conditions. The wave amplitudes and phases are continuously modified by resonant energy transfer. Since the resonance conditions are algebraic equations for frequencies, so the wave numbers are discrete, form a denumerable set, and is homeomorphic to Cantor's set of rational numbers. Since an infinite number of these sets can exist over a finite real interval, non-linear Navier-Stokes equations have multiple solutions and the initial conditions determine which particular set is excited. Consequently, the influence of initial conditions can persist forever. This phenomenon has been observed for Couette-Taylor instability, turbulent mixing layers, wakes, jets, pipe flows, etc..

Yao, Lun-Shin

1999-11-01

262

Extraction of Bearing Fault Transients from a Strong Continuous Signal Via DWPA Multiple Hand-Pass Filtering.  

National Technical Information Service (NTIS)

This paper presents a new method to enhance the detection and diagnosis of rolling element-bearing faults based on discrete wavelet packet analysis (DWPA). The extraction of attenuated resonant vibrations due to impacts from localized faults in rolling el...

J. Altmann J. Mathew

2001-01-01

263

Superconducting coplanar waveguide resonators for electron spin resonance applications  

NASA Astrophysics Data System (ADS)

Superconducting coplanar waveguide (CPW) resonators are a promising alternative to conventional volume resonators for electron spin resonance (ESR) experiments where the sample volume and thus the number of spins is small. However, the magnetic fields required for ESR could present a problem for Nb superconducting resonators, which can be driven normal. Very thin Nb films (50 nm) and careful alignment of the resonators parallel to the magnetic field avoid driving the Nb normal, but flux trapping can still be an issue. Trapped flux reduces the resonator Q-factor, can lead to resonant frequency instability, and can lead to magnetic field inhomogeneities. At temperatures of 1.9 K and in a magnetic field 0.32 T, we have tested X-band resonators fabricated directly on the surface of a silicon sample. Q-factors in excess of 15,000 have been obtained. A thin layer of GE varnish applied directly to the resonator has been used to glue a sapphire wafer to its surface, and we still find Q-factors of 16,000 or more in the 0.32 T field. ESR applications of these resonators will be discussed.

Sigillito, A. J.; Jock, R. M.; Tyryshkin, A. M.; Malissa, H.; Lyon, S. A.

2013-03-01

264

Wideband energy harvesting for piezoelectric devices with linear resonant behavior.  

PubMed

In this paper, an active energy harvesting technique for a spring-mass-damper mechanical resonator with piezoelectric electromechanical coupling is investigated. This technique applies a square-wave voltage to the terminals of the device at the same frequency as the mechanical excitation. By controlling the magnitude and phase angle of this voltage, an effective impedance matching can be achieved which maximizes the amount of power extracted from the device. Theoretically, the harvested power can be the maximum possible value, even at off-resonance frequencies. However, in actual implementation, the efficiency of the power electronic circuit limits the amount of power harvested. A power electronic full-bridge converter is built to implement the technique. Experimental results show that the active technique can increase the effective bandwidth by a factor of more than 2, and harvests significantly higher power than rectifier-based circuits at off-resonance frequencies. PMID:21768014

Luo, Cheng; Hofmann, Heath F

2011-07-01

265

Resonant cavity LED's optimized for coupling to polymer optical fibers  

Microsoft Academic Search

Planar resonant-cavity light-emitting diodes have been optimized to meet optical interconnect requirements. The microcavity effect is exploited to increase the extraction efficiency into a given numerical aperture and to reduce the crosstalk in parallel optical interconnect applications. Devices are fabricated with an overall quantum efficiency of 3.7% into a polymer optical fiber with a numerical aperture of 0.5 and a

Ronny Bockstaele; Carl Sys; J. Bondelle; Bart Dhoedt; Ingrid Moerman; Peter Van Daele; Piet Demeester; Roel Baets

1999-01-01

266

Texture coding in the rat whisker system: slip-stick versus differential resonance.  

PubMed

Rats discriminate surface textures using their whiskers (vibrissae), but how whiskers extract texture information, and how this information is encoded by the brain, are not known. In the resonance model, whisker motion across different textures excites mechanical resonance in distinct subsets of whiskers, due to variation across whiskers in resonance frequency, which varies with whisker length. Texture information is therefore encoded by the spatial pattern of activated whiskers. In the competing kinetic signature model, different textures excite resonance equally across whiskers, and instead, texture is encoded by characteristic, nonuniform temporal patterns of whisker motion. We tested these models by measuring whisker motion in awake, behaving rats whisking in air and onto sandpaper surfaces. Resonant motion was prominent during whisking in air, with fundamental frequencies ranging from approximately 35 Hz for the long Delta whisker to approximately 110 Hz for the shorter D3 whisker. Resonant vibrations also occurred while whisking against textures, but the amplitude of resonance within single whiskers was independent of texture, contradicting the resonance model. Rather, whiskers resonated transiently during discrete, high-velocity, and high-acceleration slip-stick events, which occurred prominently during whisking on surfaces. The rate and magnitude of slip-stick events varied systematically with texture. These results suggest that texture is encoded not by differential resonant motion across whiskers, but by the magnitude and temporal pattern of slip-stick motion. These findings predict a temporal code for texture in neural spike trains. PMID:18752354

Wolfe, Jason; Hill, Dan N; Pahlavan, Sohrab; Drew, Patrick J; Kleinfeld, David; Feldman, Daniel E

2008-08-26

267

Oilseed extraction process  

SciTech Connect

A process is provided for the recovery of a separate lecithin/phosphatide-rich product during the extraction of soybeans with an isopropanol-based solvent. The invention comprises steps for contacting soybeans with solvent to obtain an extracted seed meal and a solvent extract of seedoils and lecithin and related phosphatides, cooling miscella to a temperature in the range from about 30/sup 0/ to 80/sup 0/ F., phase separating the cooled miscella, recovering from the phase separation an upper solvent-rich phase, an intermediate lecithin/phosphatide-rich phase and a lower crude oil phase, and directly recycling the solvent-rich phase to the extractor.

Sullivan, D. A.

1985-05-07

268

Simulation and beamline experiments for the superconducting electron cyclotron resonance ion source VENUS  

SciTech Connect

The particle-in-cell code WARP has been enhanced to incorporate both two- and three-dimensional sheath extraction models giving WARP the capability of simulating entire ion beam transport systems including the extraction of beams from plasma sources. In this article, we describe a method of producing initial ion distributions for plasma extraction simulations in electron cyclotron resonance (ECR) ion sources based on experimentally measured sputtering on the source biased disk. Using this initialization method, we present preliminary results for extraction and transport simulations of an oxygen beam and compare them with experimental beam imaging on a quartz viewing plate for the superconducting ECR ion source VENUS.

Todd, Damon S.; Leitner, Daniela; Lyneis, Claude M.; Grote, David P. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

2008-02-15

269

Detection and identification of underwater targets by resonance or resonant scattering  

Microsoft Academic Search

This paper presents the resonance or resonant scattering technique for detection and identification of underwater targets. Based on the resonance theory and the resonant scattering theory (RST), all underwater objects resonate at their natural frequencies when impinged by acoustic energy. These resonating natural frequencies appear as modulations on the frequency domain of the target echoes. Since these natural resonances are

Gee-In Goo

1997-01-01

270

Seismic Resonant Emission  

NASA Astrophysics Data System (ADS)

There are several classes of underground objects which can produce resonant emission after being hit by incident seismic waves. Those objects include tunnels, pipes, buried containers, ground-filled excavations, unexploded ordinances, fluid-filled fractures, mine shafts, and the like. Being high contrast scatterers, these objects are capable of generating strong scattered waves where primary PP, PS, SS waves carry away most of the energy which was brought by incident waves. For both high- and low- velocity objects the primary scattered waves have the same order of magnitude as incident waves. The main difference between these groups of objects is in later arrivals of multiple scattered waves. While high-velocity objects effectively radiate most of the energy soon after impact, the low-velocity objects trap some fraction of incident wave energy in the form of circumferential waves which propagate rotating along the interface between the object and the embedding medium. Circumferential waves include surface Rayleigh-type waves (propagating mostly in the embedding medium), Stoneley waves (propagating mostly in the fluid, if present), and Frantz waves (body waves trapped in the object because of its curvature). Strong impedance contrast ensures small radiation loss for circumferential waves and they slowly decay in amplitude while rotating inside/around the object. Some circumferential waves exist in the high-velocity objects but their amplitudes decay very fast because of strong radiation in outer medium. Most of the secondary (multiply reflected from an object's boundaries or multiply circled around the object) resonant-scattered energy radiates in the embedding medium as shear waves. The possibility of neglecting P- waves in late scattering arrivals simplifies imaging as is demonstrated for the field and modeled data of the example. Resonant emission phenomenon provides an effective tool for active monitoring for a number of applications such as tunnel detection, hydrofrac development, mining operations etc.

Korneev, V. A.

2007-12-01

271

Malonamides as New Extractants.  

National Technical Information Service (NTIS)

Diamides of carboxylic acids could be an alternative to the mixture (carbamoylphosphonate, TBP) which is used nowadays in the TRUEX process to extract actinides from radioactive wastes. These solvents are economically interesting because they are easy to ...

C. Cuillerdier H. Hubert P. Hoel C. Musikas

1988-01-01

272

Automated Metadata Extraction.  

National Technical Information Service (NTIS)

Metadata is data that describes data. There are many computer forensic uses of metadata and being able to extract metadata automatically provides positive forensic implications. This thesis presents a new technique for batch processing disk images and aut...

J. Migletz

2008-01-01

273

Peat dewatering: solvent extraction  

SciTech Connect

The objective of this program is to determine the preliminary technical and economic feasibility of using IGT's solvent-extraction process for the dewatering of peat. Parallel objectives of the program are to: identify organic solvents that can be readily used to dewater raw peat by IGT's solvent-extraction process; design, construct, and operate bench-scale equipment for testing the most promising solvents; and estimate the preliminary economics of the process for a commerical-scale peat dewatering plant using a selective solvent. The results indicate that: solvent-extraction dewatering can remove up to 90% of the water in peat; and diethyl ketone (DEK) and benzene appear to dewater peat better than the other solvents tested. A preliminary economic evaluation of solvent-extraction dewatering of peat with DEK shows that the cost of this type of dewatering method is not currently competitive with other peat dewatering methods. (DWC)

Paganessi, J.E.; Mensinger, M.C.; Tsaros, C.L.; Arora, J.

1981-01-01

274

Resonance test system  

DOEpatents

An apparatus (10) for applying at least one load to a specimen (12) according to one embodiment of the invention may comprise a mass (18). An actuator (20) mounted to the specimen (12) and operatively associated with the mass (18) moves the mass (18) along a linear displacement path (22) that is perpendicular to a longitudinal axis of the specimen (12). A control system (26) operatively associated with the actuator (20) operates the actuator (20) to reciprocate the mass (18) along the linear displacement path (22) at a reciprocating frequency, the reciprocating frequency being about equal to a resonance frequency of the specimen (12) in a test configuration.

Musial, Walter (Boulder, CO); White, Darris (Superior, CO)

2011-05-31

275

Breast magnetic resonance imaging.  

PubMed

Mammography has long been considered the gold standard for screening breast cancer. Although it reduces the risk of breast cancer mortality by enabling early diagnosis, it does not detect all breast cancers. Numerous breast imaging technologies are emerging as effective adjunctive diagnostic tools when mammography results are negative or inconclusive. Contrast-enhanced magnetic resonance (CE-MR) imaging, in particular, has demonstrated a high sensitivity and has proven to be most effective, especially with patients at high risk for developing breast cancer. This article discusses the clinical applications for breast MR imaging, use of CE-MR for breast cancer detection, and other emerging breast imaging technologies. PMID:22267704

Johnson, Marlene M

2012-01-01

276

Nuclear Magnetic Resonance Gyroscope  

NASA Astrophysics Data System (ADS)

The navigation grade micro Nuclear Magnetic Resonance Gyroscope (micro-NMRG) being developed by the Northrop Grumman Corporation is currently in phase 4 of the DARPA Navigation Grade Integrated Micro Gyro (NGIMG) program. The micro-NMRG technology is pushing the boundaries of size, weight, power, and performance allowing new small platform applications of navigation grade Inertial Navigation System (INS) technology. Information on the historical development of the technology, basics of operation, task performance goals, application opportunities, and a phase 2 sample of earth rate measurement data will be presented.

Larsen, Michael

2011-06-01

277

DNA Extraction Virtual Lab  

NSDL National Science Digital Library

This virtual lab from the Genetic Science Learning Center at the University of Utah provides a simple overview of DNA extraction, including what it's used for, illustrations, and an activity using cheek cells and laboratory equipment to isolate DNA. The lab is followed by a classroom activity that allows students and teachers to Extract DNA from Anything Living, using household items like spinach but not little sister's big toe.

2006-01-01

278

Liquid chromatographic extraction medium  

DOEpatents

A method and apparatus are disclosed for extracting strontium and technetium values from biological, industrial and environmental sample solutions using a chromatographic column. An extractant medium for the column is prepared by generating a solution of a diluent containing a Crown ether and dispersing the solution on a resin substrate material. The sample solution is highly acidic and is introduced directed to the chromatographic column and strontium or technetium is eluted using deionized water. 1 fig.

Horwitz, E.P.; Dietz, M.L.

1994-09-13

279

Liquid chromatographic extraction medium  

DOEpatents

A method and apparatus for extracting strontium and technetium values from biological, industrial and environmental sample solutions using a chromatographic column is described. An extractant medium for the column is prepared by generating a solution of a diluent containing a Crown ether and dispersing the solution on a resin substrate material. The sample solution is highly acidic and is introduced directed to the chromatographic column and strontium or technetium is eluted using deionized water.

Horwitz, E. Philip (Naperville, IL); Dietz, Mark L. (Evanston, IL)

1994-01-01

280

Stabilizing hadron resonance gas models  

SciTech Connect

We examine the stability of hadron resonance gas models by extending them to include undiscovered resonances through the Hagedorn formula. We find that the influence of unknown resonances on thermodynamics is large but bounded. We model the decays of resonances and investigate the ratios of particle yields in heavy-ion collisions. We find that observables such as hydrodynamics and hadron yield ratios change little upon extending the model. As a result, heavy-ion collisions at the RHIC and LHC are insensitive to a possible exponential rise in the hadronic density of states, thus increasing the stability of the predictions of hadron resonance gas models in this context. Hadron resonance gases are internally consistent up to a temperature higher than the crossover temperature in QCD, but by examining quark number susceptibilities we find that their region of applicability ends below the QCD crossover.

Chatterjee, S.; Godbole, R. M. [Center for High Energy Physics, Indian Institute of Science, Bangalore 560012 (India); Gupta, Sourendu [Department of Theoretical Physics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India)

2010-04-15

281

DISSIPATIVE DIVERGENCE OF RESONANT ORBITS  

SciTech Connect

A considerable fraction of multi-planet systems discovered by the observational surveys of extrasolar planets reside in mild proximity to first-order mean-motion resonances. However, the relative remoteness of such systems from nominal resonant period ratios (e.g., 2:1, 3:2, and 4:3) has been interpreted as evidence for lack of resonant interactions. Here, we show that a slow divergence away from exact commensurability is a natural outcome of dissipative evolution and demonstrate that libration of critical angles can be maintained tens of percent away from nominal resonance. We construct an analytical theory for the long-term dynamical evolution of dissipated resonant planetary pairs and confirm our calculations numerically. Collectively, our results suggest that a significant fraction of the near-commensurate extrasolar planets are in fact resonant and have undergone significant dissipative evolution.

Batygin, Konstantin [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Morbidelli, Alessandro, E-mail: kbatygin@gps.caltech.edu [Departement Cassiopee, Universite de Nice-Sophia Antipolis, Observatoire de la Cote d'Azur, F-06304 Nice (France)

2013-01-01

282

Optical resonator and laser applications  

NASA Technical Reports Server (NTRS)

The invention discloses a semi-ring Fabry-Perot (SRFP) optical resonator structure comprising a medium including an edge forming a reflective facet and a waveguide within the medium, the waveguide having opposing ends formed by the reflective facet. The performance of the SRFP resonator can be further enhanced by including a Mach-Zehnder interferometer in the waveguide on one side of the gain medium. The optical resonator can be employed in a variety of optical devices. Laser structures using at least one SRFP resonator are disclosed where the resonators are disposed on opposite sides of a gain medium. Other laser structures employing one or more resonators on one side of a gain region are also disclosed.

Taghavi-Larigani, Shervin (Inventor); Vanzyl, Jakob J. (Inventor); Yariv, Amnon (Inventor)

2006-01-01

283

States in 12B and primordial nucleosynthesis (II). Resonance properties and astrophysical aspects  

NASA Astrophysics Data System (ADS)

The 9Be(?, p)12B has been used to populate states which could correspond to astrophysically significant resonances in the 8Li(?, n)11B reaction. The branching ratios for neutron decays have been measured and the neutron angular distributions have been used to determine J? for these states. This information, combined with previous measurements of excitation energies and total widths, allows us to extract the resonance strengths for these states. The astrophysical significance of these results is discussed.

Mao, Z. Q.; Vogelaar, R. B.; Champagne, A. E.; Blackmon, J. C.; Das, R. K.; Hahn, K. I.; Yuan, J.

1994-01-01

284

Resonant converter power line conditioner  

Microsoft Academic Search

A power description is given of the operation and design of a power-line conditioner (PLC) utilizing the principles of a resonant converter. The PLC uses an L-C circuit which resonates at a high frequency. The PLC is connected in parallel with a load, and it injects high-frequency resonant current pulses into the supply lines at regular sampling intervals so that

S. Deb; R. G. Hoft

1988-01-01

285

Resonance Broadening of Spectral Lines  

Microsoft Academic Search

A new approach is suggested for dealing with the many-body aspects of resonance broadening of spectral lines in gases. A Liouville-space formalism is used in which the absorption by N identical molecules undergoing resonance-exchange collisions is described by an N-dimensional projection operator in Liouville space. In the impact approximation, under conditions in which the Doppler shift of resonance frequencies can

A. Ben-Reuven

1971-01-01

286

GAUSSIAN BEAM LASER RESONATOR PROGRAM  

NASA Technical Reports Server (NTRS)

In designing a laser cavity, the laser engineer is frequently concerned with more than the stability of the resonator. Other considerations include the size of the beam at various optical surfaces within the resonator or the performance of intracavity line-narrowing or other optical elements. Laser resonators obey the laws of Gaussian beam propagation, not geometric optics. The Gaussian Beam Laser Resonator Program models laser resonators using Gaussian ray trace techniques. It can be used to determine the propagation of radiation through laser resonators. The algorithm used in the Gaussian Beam Resonator program has three major components. First, the ray transfer matrix for the laser resonator must be calculated. Next calculations of the initial beam parameters, specifically, the beam stability, the beam waist size and location for the resonator input element, and the wavefront curvature and beam radius at the input surface to the first resonator element are performed. Finally the propagation of the beam through the optical elements is computed. The optical elements can be modeled as parallel plates, lenses, mirrors, dummy surfaces, or Gradient Index (GRIN) lenses. A Gradient Index lens is a good approximation of a laser rod operating under a thermal load. The optical system may contain up to 50 elements. In addition to the internal beam elements the optical system may contain elements external to the resonator. The Gaussian Beam Resonator program was written in Microsoft FORTRAN (Version 4.01). It was developed for the IBM PS/2 80-071 microcomputer and has been implemented on an IBM PC compatible under MS DOS 3.21. The program was developed in 1988 and requires approximately 95K bytes to operate.

Cross, P. L.

1994-01-01

287

Resonance acoustic field position sensor  

NASA Astrophysics Data System (ADS)

An acoustic position sensor, based on a piezoelectric-sound-resonance cavity (PSRC), is reported in which a resonance acoustic field is used as the sensing mechanism. It has been discovered that an inserted object or an object motion in the sound radiation field results in changes in the resonance state of the PSRC. Experiments have demonstrated a high position resolution in the axial direction, and also good sensitivity in the transverse.

Dong, Shuxiang; Bai, Feiming; Li, Jie-Fang; Viehland, Dwight

2003-06-01

288

Optical resonators and laser beams  

NASA Astrophysics Data System (ADS)

The formation of coherent emission in optical resonators is examined on the basis of the fundamental laws governing the transmission of coherent light beams through a wide range of optical systems. The factors determining the spatial structure of laser emission are analyzed, and recommendations are given concerning the choice of resonator parameters. Methods for varying the emission characteristics through resonator modification are discussed. Particular attention is given to methods of improving the spatial coherence of laser emission and reducing its divergence.

Anan'ev, Iurii A.

289

Abdominal magnetic resonance elastography.  

PubMed

Magnetic resonance elastography (MRE) is a magnetic resonance imaging-based technique for quantitatively assessing the mechanical properties of tissues based on the propagation of shear waves. Multiple studies have described many potential applications of MRE, from characterizing tumors to detecting diffuse disease processes. Studies have shown that MRE can be successfully implemented to assess abdominal organs. The first clinical application of MRE to be well documented is the detection and characterization of hepatic fibrosis, which systematically increases the stiffness of liver tissue. In this diagnostic role, it offers a safer, less expensive, and potentially more accurate alternative to invasive liver biopsy. Emerging results suggest that measurements of liver and spleen stiffness may provide an indirect way to assess portal hypertension. Preliminary studies have demonstrated that it is possible to use MRE to evaluate the mechanical properties of other abdominal structures, such as the pancreas and kidneys. Steady technical progress in developing practical protocols for applying MRE in the abdomen and the pelvis provides opportunities to explore many other potential applications of this emerging technology. PMID:20010062

Yin, Meng; Chen, Jun; Glaser, Kevin J; Talwalkar, Jayant A; Ehman, Richard L

2009-04-01

290

Nuclear Magnetic Resonance Gyroscope  

NASA Astrophysics Data System (ADS)

The navigation grade micro Nuclear Magnetic Resonance Gyroscope (micro-NMRG) being developed by the Northrop Grumman Corporation is concluding the fourth and final phase of the DARPA Navigation Grade Integrated Micro Gyro (NGIMG) program. Traditional MEMS gyros utilize springs as an inherent part of the sensing mechanism, leading to bias and scale factor sensitivity to acceleration and vibration. As a result, they have not met performance expectations in real world environments and to date have been limited to tactical grade applications. The Nuclear Magnetic Resonance Gyroscope (NMRG) utilizes the fixed precession rate of a nuclear spin in a constant magnetic field as an inertial reference for determining rotation. The nuclear spin precession rate sensitivity to acceleration and vibration is negligible for most applications. Therefore, the application of new micro and batch fabrication methods to NMRG technology holds great promise for navigation grade performance in a low cost and compact gyro. This poster will describe the history, operational principles, and design basics of the NMRG including an overview of the NSD designs developed and demonstrated in the DARPA gyro development program. General performance results from phases 3 and 4 will also be presented.

Bulatowicz, Michael; Clark, Philip; Griffith, Robert; Larsen, Michael; Mirijanian, James

2012-06-01

291

Behavioral Stochastic Resonance  

NASA Astrophysics Data System (ADS)

Zooplankton emit weak electric fields into the surrounding water that originate from their own muscular activities associated with swimming and feeding. Juvenile paddlefish prey upon single zooplankton by detecting and tracking these weak electric signatures. The passive electric sense in the fish is provided by an elaborate array of electroreceptors, Ampullae Lorenzini, spread over the surface of an elongated rostrum. We have previously shown that the fish use stochastic resonance to enhance prey capture near the detection threshold of their sensory system. But stochastic resonance requires an external source of electrical noise in order to function. The required noise can be provided by a swarm of plankton, for example Daphnia. Thus juvenile paddlefish can detect and attack single Daphnia as outliers in the vicinity of the swarm by making use of noise from the swarm itself. From the power spectral density of the noise plus the weak signal from a single Daphnia we calculate the signal-to-noise ratio and the Fisher information at the surface of the paddlefish's rostrum. The results predict a specific attack pattern for the paddlefish that appears to be experimentally testable.

Freund, Jan A.; Schimansky-Geier, Lutz; Beisner, Beatrix; Neiman, Alexander; Russell, David F.; Yakusheva, Tatyana; Moss, Frank

2001-03-01

292

Resonant Wave-Particle Manipulation Techniques  

NASA Astrophysics Data System (ADS)

Charged particle dynamics can be altered considerably even by weak electromagnetic waves if some of the particles are in resonance. Depending on the wave parameters, the resonances in the phase space can either be well separated, in which case the particle dynamics is regular almost everywhere, or they can overlap leading to stochastic particle motion in a large volume of the phase space. Although different, both of these regimes allow one to manipulate particle ensembles by arranging resonant interactions with appropriate waves. This thesis is devoted to studying two wave-particle manipulation techniques having potential applications in fusion and laser-plasma interaction research. Specifically, we study the alpha-channeling effect (which relies on stochastic diffusion of resonant particles) and the so-called negative-mass effect (NME) (which involves the conservation of the adiabatic invariant). The alpha-channeling effect entails the use of radio-frequency waves to expel and cool high-energetic alpha particles born in a fusion reactor; the device reactivity can then be increased even further by redirecting the extracted energy to fuel ions. Recently, the alpha-channeling technique, originally proposed for tokamaks, was shown to be suitable for application in mirror machines as well. In the first part of this thesis, we deepen the understanding of issues and possibilities of the alpha-channeling implementation in open-ended reactors. We verify the feasibility of this technique and identify specific waves and supplementary techniques, which can potentially be used for implementing the alpha-channeling in realistic mirror devices. We also propose a new technique for using the alpha-channeling wave energy to catalyze fusion reaction by employing minority ions as a mediator species. In the second part of this thesis, the NME manifesting itself as an unusual response of a resonant particle to external adiabatic perturbations mimicking the behavior of a particle with a negative mass, is discussed. Using the Hamiltonian perturbation theory, the calculation of the effective parallel mass is extended to the non-vacuum waves and the NME is shown to be robust. Also, the consequences of radiation friction and collisions with the background particles on the NME are studied and new collective phenomena emerging in plasmas with negative-mass particles are considered.

Zhmoginov, Andrey I.

293

Hyperon Resonance Photoproduction at CLAS  

SciTech Connect

The study of hyperon resonances has entered a new era of precision with advent of high-statistics photoproduction data from the CLAS detector at Jeffersonnext term Lab. These data have multi-particle final states, allowing clean identification of exclusive reactions associated with strange mesons and baryons. Examples of physics results are: evidence for isospin interference in the decay of the ?(1405) resonance; a strong suggestion of meson cloud effects in the structure of the Sigma (1385) resonance; data from Klow asterisk photoproduction that will test the existence of the purported K0(800) meson. Properties of other hyperon resonances will also be studied in the near future.

K. Hicks, D. Keller, W. Tang

2011-02-01

294

Electromagnetic production of hyperon resonances  

SciTech Connect

The study of hyperon resonances has entered a new era of precision with advent of high-statistics photoproduction data from the CLAS detector at Jefferson Lab. These data have multi-particle final states, allowing clean identification of exclusive reactions associated with strange mesons and baryons. Examples of physics results are: evidence for isospin interference in the decay of the {Lambda}(1405) resonance; a strong suggestion of meson cloud effects in the structure of the {Sigma}(1385) resonance; data from K* photoproduction that will test the existence of the purported K{sub 0}(800) meson. Properties of other hyperon resonances will also be studied in the near future.

Hicks, K.; Keller, D.; Tang, W. [Dept. of Physics and Astronomy, Ohio University, Athens OH 45701 (United States)

2011-10-24

295

Electromagnetic production of hyperon resonances  

SciTech Connect

The study of hyperon resonances has entered a new era of precision with advent of high-statistics photoproduction data from the CLAS detector at Jefferson Lab. These data have multi-particle final states, allowing clean identification of exclusive reactions associated with strange mesons and baryons. Examples of physics results are: evidence for isospin interference in the decay of the {Lambda}(1405) resonance; a strong suggestion of meson cloud effects in the structure of the {Sigma}(1385) resonance; data from K* photoproduction that will test the existence of the purported K{sub 0}(800)$ meson. Properties of other hyperon resonances will also be studied in the near future.

K. Hicks, D. Keller, W. Tang

2011-10-01

296

Fano resonances in magnetic metamaterials  

SciTech Connect

We study the scattering of magnetoinductive plane waves by internal (external) capacitive (inductive) defects coupled to a one-dimensional split-ring resonator array. We examine a number of simple defect configurations where Fano resonances occur and study the behavior of the transmission coefficient as a function of the controllable external parameters. We find that for embedded capacitive defects, the addition of a small amount of coupling to second neighbors is necessary for the occurrence of Fano resonance. For external inductive defects, Fano resonances are commonplace, and they can be tuned by changing the relative orientation or distance between the defect and the SSR array.

Naether, Uta; Molina, Mario I. [Departmento de Fisica, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile) and Center for Optics and Photonics (CEFOP), Casilla 4016, Concepcion (Chile)

2011-10-15

297

Acoustic detection of microbubble resonance  

NASA Astrophysics Data System (ADS)

Large numbers of acoustic signals from single lipid-shelled Definity® microbubbles have been measured using a calibrated microacoustic system and a two population response observed. Theoretical results based on the Mooney-Rivlin strain softening shell model have been used to identify these populations as primary resonant and off-primary resonant scatter. An experimentally measured size distribution was used to provide the initial resting radius for the simulations, and the responses agree well with the experimental data. In this way, the primary resonant or off-primary resonant behavior of a microbubble can be studied, with potential benefits to both signal processing techniques and microbubble manufacture.

Thomas, D. H.; Looney, P.; Steel, R.; Pelekasis, N.; McDicken, W. N.; Anderson, T.; Sboros, V.

2009-06-01

298

Proton spin structure in the resonance region.  

PubMed

We have examined the spin structure of the proton in the region of the nucleon resonances (1.085 GeVextracted the asymmetries A1 and A2, and the spin structure functions g1 and g2. We found a notably nonzero A(perpendicular), significant contributions from higher-twist effects, and only weak support for polarized quark-hadron duality. PMID:17501192

Wesselmann, F R; Slifer, K; Tajima, S; Aghalaryan, A; Ahmidouch, A; Asaturyan, R; Bloch, F; Boeglin, W; Bosted, P; Carasco, C; Carlini, R; Cha, J; Chen, J P; Christy, M E; Cole, L; Coman, L; Crabb, D; Danagoulian, S; Day, D; Dunne, J; Elaasar, M; Ent, R; Fenker, H; Frlez, E; Gan, L; Gaskell, D; Gomez, J; Hu, B; Jones, M K; Jourdan, J; Keith, C; Keppel, C E; Khandaker, M; Klein, A; Kramer, L; Liang, Y; Lichtenstadt, J; Lindgren, R; Mack, D; McKee, P; McNulty, D; Meekins, D; Mkrtchyan, H; Nasseripour, R; Niculescu, I; Normand, K; Norum, B; Pocanic, D; Prok, Y; Raue, B; Reinhold, J; Roche, J; Rohe, D; Rondón, O A; Savvinov, N; Sawatzky, B; Seely, M; Sick, I; Smith, C; Smith, G; Stepanyan, S; Tang, L; Testa, G; Vulcan, W; Wang, K; Warren, G; Wood, S; Yan, C; Yuan, L; Yun, J; Zeier, M; Zhu, H

2007-03-30

299

Proton Spin Structure in the Resonance Region  

SciTech Connect

We have examined the spin structure of the proton in the region of the nucleon resonances (1.085 GeVextracted the asymmetries A{sub 1} and A{sub 2}, and the spin structure functions g{sub 1} and g{sub 2}. We found a notably nonzero A{sub perpendicular}, significant contributions from higher-twist effects, and only weak support for polarized quark-hadron duality.

Wesselmann, F. R. [University of Virginia, Charlottesville, Virginia 22903 (United States); Norfolk State University, Norfolk, Virginia 23504 (United States); Slifer, K.; Tajima, S.; Crabb, D.; Day, D.; Frlez, E.; Lindgren, R.; McKee, P.; McNulty, D.; Norum, B.; Pocanic, D.; Prok, Y.; Rondon, O. A.; Sawatzky, B.; Smith, C.; Wang, K.; Zeier, M.; Zhu, H. [University of Virginia, Charlottesville, Virginia 22903 (United States); Aghalaryan, A.; Asaturyan, R. [Yerevan Physics Institute, Yerevan (Armenia)] (and others)

2007-03-30

300

Vacuum Properties of the ?(1385)+ Resonance  

NASA Astrophysics Data System (ADS)

We present data taken employing a proton beam incident on a liquid hydrogen target with a kinetic energy of 3.5 GeV. A total statistics of ~ 1.2.109 events was collected by the High Acceptance Di-Electron Spectrometer (HADES) and analysed to study the properties of the ?(1385)+-resonance. A clear signal corresponding to a peak of the Breit-Wigner parametrization of M = 1382.98+/-0.79MeV/c2 and a width of ?0 = 38.78+/-2.03 MeV/c2 was extracted. The investigation of the differential production cross- section shows a strong anisotropy in the angular distribution of the ?(1385)+-hyperon with respect to the beam direction in p+p collisions.

Epple, E.

2011-10-01

301

Identification of benzethonium chloride in commercial grapefruit seed extracts.  

PubMed

Commercial grapefruit seed extracts (GSE) were extracted with chloroform. The solvent was evaporated, and the resulting solid was subsequently analyzed by high-performance liquid chromatography, electrospray ionization mass spectrometry, nuclear magnetic resonance (NMR) spectroscopy, and elemental analysis (by proton-induced X-ray emission [PIXE] analysis). The main constituent was identified as benzethonium chloride, a synthetic antimicrobial agent commonly used in cosmetics and other topical applications. This compound comprised 8.03% (n = 2) of the liquid GSE sample. Higher amounts of benzethonium chloride were found in powder GSE samples. PMID:11453769

Takeoka, G; Dao, L; Wong, R Y; Lundin, R; Mahoney, N

2001-07-01

302

Nano-electromembrane extraction.  

PubMed

The present work has for the first time described nano-electromembrane extraction (nano-EME). In nano-EME, five basic drugs substances were extracted as model analytes from 200 ?L acidified sample solution, through a supported liquid membrane (SLM) of 2-nitrophenyl octyl ether (NPOE), and into approximately 8 nL phosphate buffer (pH 2.7) as acceptor phase. The driving force for the extraction was an electrical potential sustained over the SLM. The acceptor phase was located inside a fused silica capillary, and this capillary was also used for the final analysis of the acceptor phase by capillary electrophoresis (CE). In that way the sample preparation performed by nano-EME was coupled directly with a CE separation. Separation performance of 42,000-193,000 theoretical plates could easily be obtained by this direct sample preparation and injection technique that both provided enrichment as well as extraction selectivity. Compared with conventional EME, the acceptor phase volume in nano-EME was down-scaled by a factor of more than 1000. This resulted in a very high enrichment capacity. With loperamide as an example, an enrichment factor exceeding 500 was obtained in only 5 min of extraction. This corresponded to 100-times enrichment per minute of nano-EME. Nano-EME was found to be a very soft extraction technique, and about 99.2-99.9% of the analytes remained in the sample volume of 200 ?L. The SLM could be reused for more than 200 nano-EME extractions, and memory effects in the membrane were avoided by effective electro-assisted cleaning, where the electrical potential was actively used to clean the membrane. PMID:23764444

Payán, María D Ramos; Li, Bin; Petersen, Nickolaj Jacob; Jensen, Henrik; Hansen, Steen Honoré; Pedersen-Bjergaard, Stig

2013-06-27

303

Magnetic Resonance Imaging and Magnetic Resonance Angiography of Vertebrobasilar Dolichoectasia  

Microsoft Academic Search

We performed magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) in 16 patients with vertebrobasilar dolichoectasia (VBD). Five patients had compressive cranial nerve deficits and 11 patients presented with transient or permanent ischemic deficits related to the vertebrobasilar system. VBD did not present with distinct clinical findings and no clear correlation between basilar artery ectasia and the presence of

Franz T. Aichner; Stephan R. Felber; Günther G. Birbamer; Andrea Posch

1993-01-01

304

Mechanism for electric dipole transitions from the broad p-wave neutron resonance in 24Mg  

Microsoft Academic Search

Neutron capture gamma rays from the 84-keV {ital p}ââ-wave resonance, 266-keV {ital p}ââ-wave resonance, and 431-keV {ital p}ââ-wave resonance in ²⁴Mg that have large reduced neutron width have been measured with an anti-Compton NaI(Tl) detector, using a time-of-flight technique. Successful extraction of gamma-ray intensities for transitions to low-lying states in ²⁵Mg was performed by an iterative unfolding method, in order

T. Uchiyama; M. Igashira; H. Kitazawa

1990-01-01

305

Scanning ferromagnetic resonance microscopy and resonant heating of magnetite nanoparticles: Demonstration of thermally detected magnetic resonance  

NASA Astrophysics Data System (ADS)

We report a 9 GHz microwave scanning probe based on a slit aperture for spatially resolved magnetic resonance detection. We use patterned layers of dispersed magnetite Fe3O4 nanoparticles and demonstrate low-field ferromagnetic resonance images with a spatial resolution of 15 ?m. We also demonstrate localized heating of magnetite nanoparticles via ferromagnetic resonance absorption which can be controlled by an external dc magnetic field. Using our microwave probe as a transmitter and a temperature sensor (thermocouple or infrared detector), we show thermally detected magnetic resonance at room temperature.

Sakran, F.; Copty, A.; Golosovsky, M.; Davidov, D.; Monod, P.

2004-05-01

306

Tevatron extraction microcomputer  

NASA Astrophysics Data System (ADS)

Extraction in the fErmilab Tevatron is controlled by a multi-processor Multibus microcomputer system called QXR (Quad extraction Regulator). QXR monitors several analog beam signals and controls three sets of power supplies: the bucker and pulse magnets at a rate of 5760 Hz, and the QXR magnets at 720 Hz. QXR supports multiple slow spills (up to a total of 35 seconds) with multiple fast pulses intermixed. It linearizes the slow spill and bucks out the high frequency components. Fast extraction is done by outputting a variable pulse waveform. Closed loop learning techniques are used to improve performance from cycle to cycle for both slow and fast extraction. The system is connected to the Tevatron clock system so that it can track the machine cycle. QXR is also connected to the rest of the Fermilab control system, ACNET. Through ACNET, human operators and central computers can monitor and control extraction through communications with QXR. The controls hardware and software both employ some standard and some specialized components. This paper gives an overview of QXR as a control system; another paper summarizes performance.

Chapman, L.; Finley, D. A.; Harrison, M.; Merz, W.

1985-06-01

307

Tevatron extraction microcomputer  

SciTech Connect

Extraction in the Fermilab Tevatron is controlled by a multi-processor Multibus microcomputer system called QXR (Quad eXtraction Regulator). QXR monitors several analog beam signals and controls three sets of power supplies: the ''bucker'' and ''pulse'' magnets at a rate of 5760 Hz, and the ''QXR'' magnets at 720 Hz. QXR supports multiple slow spills (up to a total of 35 seconds) with multiple fast pulses intermixed. It linearizes the slow spill and bucks out the high frequency components. Fast extraction is done by outputting a variable pulse waveform. Closed loop learning techniques are used to improve performance from cycle to cycle for both slow and fast extraction. The system is connected to the Tevatron clock system so that it can track the machine cycle. QXR is also connected to the rest of the Fermilab control system, ACNET. Through ACNET, human operators and central computers can monitor and control extraction through communications with QXR. The controls hardware and software both employ some standard and some specialized components. This paper gives an overview of QXR as a control system; another paper summarizes performance.

Chapman, L.; Finley, D.A.; Harrison, M.; Merz, W.

1985-06-01

308

State equations based resonant converters modeling technique  

Microsoft Academic Search

State equations for resonant converters are developed by using orthogonal circuit synthesis. Low frequency state variables are selected for the resonant circuit, such as envelopes of resonant inductor current and resonant capacitor voltage, phase angle between inverter output voltage and output current. For a given resonant tank, its orthogonal counterpart is constructed. These two orthogonal tanks are combined into a

Yingqi Zhang; P. C. Sen

2010-01-01

309

Evaluation and Treatment of Resonance Disorders  

Microsoft Academic Search

Resonance disorders can be caused by a variety of structural abnormalities in the resonating chambers for speech, or by velopharyngeal dysfunction. These abnormalities may result in hypernasality, hypo- or denasality, or cul-de-sac resonance. Resonance disorders are commonly seen in patients with craniofacial anoma- lies, particularly a history of cleft palate. The appropriate evaluation of a resonance disorder includes a speech

Ann W. Kummer; Linda Lee

310

Simple and Inexpensive Classroom Demonstrations of Nuclear Magnetic Resonance and Magnetic Resonance Imaging.  

ERIC Educational Resources Information Center

Describes a set of simple, inexpensive, classical demonstrations of nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) principles that illustrate the resonance condition associated with magnetic dipoles and the dependence of the resonance frequency on environment. (WRM)

Olson, Joel A.; Nordell, Karen J.; Chesnik, Marla A.; Landis, Clark R.; Ellis, Arthur B.; Rzchowski, M. S.; Condren, S. Michael; Lisensky, George C.

2000-01-01

311

New Method for Determining the Quality Factor and Resonance Frequency of Superconducting Micro-resonators from Sonnet Simulation  

NASA Astrophysics Data System (ADS)

Lithographed superconducting microwave resonators (micro-resonators) are useful in a number of important applications including microwave kinetic inductance detectors (MKIDs), as a memory element in quantum information, and readout of qubits and nanomechanical resonators. One of the major tasks in designing these devices is to find the resonance frequency (fr) and quality factor (Q) for these microwave circuits using EM simulation software such as Sonnet. The traditional method iteratively sweeps and zooms in frequency to fit simulated S21 data, which is often time consuming. In this work, we show a new---and much faster---method for determining frand Q by adding an internal (virtual) port in the Sonnet model and examining the input impedance through the added port. Accurate fr and Q values can be retrieved from a single simulation with a wide frequency sweep. This is a robust method that works on many types of resonance circuits and eclipses the speed with which Q is traditionally extracted by eliminating the need for multiple frequency sweeps using Sonnet.

Wisbey, David; Reinisch, Alexander; Gardner, Wesley; Brewster, Jacob; Gao, Jiansong

2013-03-01

312

Cryogenic Resonator Complex  

NASA Astrophysics Data System (ADS)

We describe a unique new-generation laboratory facility for studying dielectric parameters of gases and condensed media, as well as reflectivity of surfaces (reflection loss) in the frequency range 100-500 GHz and pressure interval from 10-3 Torr to the atmospheric pressure at temperatures of 4 to 370 K. The Fabry-Perot resonators with Q-factors of about 106, in which the studied gas, dielectric, or reflector are located, are the measuring elements of the facility. The backward-wave oscillator stabilized by the wideband phased-lock loop is the radiation source. Using this facility, we were able, in particular, to confirm the presence of water dimers in the atmosphere and study some materials for the reflectors of the "Millimetron" space observatory.

Parshin, V. V.; Serov, E. A.; Bubnov, G. M.; Vdovin, V. F.; Koshelev, M. A.; Tretyakov, M. Yu.

2014-01-01

313

Coherent Nuclear Resonance Fluorescence  

NASA Astrophysics Data System (ADS)

For a long time, the impact of ideas with respect to coherency and scattering on the art and science of Mössbauer spectroscopy was not very essential. The main line of development of Mössbauer experiments rested in the frame of absorption spectroscopy. Mössbauer physicists dealt mostly with absorption spectra taken either in traditional transmission experiments or in measurements of the conversion electron yield. For the interpretation and description of these spectra, it was appropriate to use the picture of interaction of ?-quantum with an individual nucleus where the nuclear resonant absorption cross-section was applied. The coherent properties of radiation and those of the interaction mechanism were not explicitly involved in these studies. In the meantime, coherent phenomena with Mössbauer ?-rays were thoroughly investigated, starting soon after Mössbauer's discovery. The present paper is aimed to illuminate this side of the Mössbauer story.

Smirnov, G. V.

314

Nonlinearity of Helmholtz resonators  

NASA Technical Reports Server (NTRS)

Consideration of the nonlinear damping of pressure oscillations by means of acoustic liners consisting of a perforated plate communicating with a volume or of individual Helmholtz resonators. A nonlinear analysis leads to a modified first-order theory; in particular, some second-order damping effects (due to the formation of jets through the orifices) are considered, while other less important damping effects (of second order) are neglected. The effect of the vena contracta in the orifice flow is also taken into account, and the conditions of maximum damping are discussed. A determination is made of the orifice velocity, the cavity pressure, the admittance coefficient, the resistance, and the reactance, and good agreement is found between the theoretically determined resistance and orifice velocity and the pertinent experimental data.

Sirignano, W. A.

1972-01-01

315

Folded dipole plasmonic resonators.  

PubMed

A class of folded ordered plasmonic dipole nanoresonators based on insulator-metal-insulator (IMI) slab waveguides is proposed and studied. This work is motivated by the development of a novel fabrication process that avoids the need for direct write nanolithography and instead relies on accessible UV lithography and other top-down parallel fabrication techniques that result in metallic dolmen structures with nanometre sized gaps. In this context, the dolmen geometry consists of two vertical segments supporting a flat horizontal slab. It is shown using frequency domain finite element analysis that such structures, which are essentially folded dipole antennas, resonate in a similar manner to their linear unfolded counterparts. The effect of the likely fabrication features is also studied. PMID:24216810

Choonee, K; Syms, R R A

2013-11-01

316

Resonances in general relativity  

NASA Astrophysics Data System (ADS)

We study decay properties of linear waves on Kerr and Kerr-de Sitter black hole backgrounds. We are particularly interested in quasi-normal modes (QNMs), which are the complex frequencies of exponentially decaying and oscillating solutions to the wave equation. For slowly rotating Kerr-de Sitter black holes, we show that QNMs obey a quantization condition; that is, they lie asymptotically on a lattice. We also obtain a resonance expansion of linear waves in terms of QNMs. For the general Kerr-de Sitter case and its small stationary perturbations, we use r-normal hyperbolicity of the set of trapped lightlike rays to obtain a band of QNMs with a Weyl law.

Dyatlov, Semen Vladimirovich

317

Immune effects of extractives on bamboo biomass self-plasticization.  

PubMed

Bamboo is a fast-growing renewable bioresource. However, bamboo resources are wasted, and bamboo products release toxic gases. Bamboo biomass was therefore extracted and self-plasticized, and the immune effects of bamboo extractives were determined and investigated using nuclear magnetic resonance (NMR) and Fourier-transform infrared (FT-IR) spectroscopies, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results showed the following. (1) The 1H-NMR signals at ~5.5, 4-8, 7.4-10.2, and 12.22-12.37 ppm were attributed to the chemical shifts of active protons on carbons adjacent to R-OH, RAr-OH, oximes, and -COOH, respectively. This showed that there were highly reactive hydrogen atoms in bamboo benzene/ethanol extractives. The 13C-NMR spectrum gave further confirmation. (2) The extents of the effects of key process parameters were different: temperature > hot pressure > time. The optimal self-plasticizing conditions were temperature 170°C, hot pressure 9 MPa, time 40 min, and extraction of bamboo. (3) SEM, FT-IR, and XRD showed that contact and linkages among bamboo cells were significantly decreased by extractives, so the internal bond strengths of the self-plasticized samples were all higher after bamboo extraction. It was also found that the extractives created a significant barrier to bamboo self-plasticization as a result of their structure and chemical linkage reactions. PMID:25016257

Peng, Wanxi; Xue, Qiu; Ohkoshi, Makoto

2014-07-01

318

Cascaded resonant bridge converters  

NASA Technical Reports Server (NTRS)

A converter for converting a low voltage direct current power source to a higher voltage, high frequency alternating current output for use in an electrical system where it is desired to use low weight cables and other circuit elements. The converter has a first stage series resonant (Schwarz) converter which converts the direct current power source to an alternating current by means of switching elements that are operated by a variable frequency voltage regulator, a transformer to step up the voltage of the alternating current, and a rectifier bridge to convert the alternating current to a direct current first stage output. The converter further has a second stage series resonant (Schwarz) converter which is connected in series to the first stage converter to receive its direct current output and convert it to a second stage high frequency alternating current output by means of switching elements that are operated by a fixed frequency oscillator. The voltage of the second stage output is controlled at a relatively constant value by controlling the first stage output voltage, which is accomplished by controlling the frequency of the first stage variable frequency voltage controller in response to second stage voltage. Fault tolerance in the event of a load short circuit is provided by making the operation of the first stage variable frequency voltage controller responsive to first and second stage current limiting devices. The second stage output is connected to a rectifier bridge whose output is connected to the input of the second stage to provide good regulation of output voltage wave form at low system loads.

Stuart, Thomas A. (Inventor)

1989-01-01

319

Nonlinear resonances: theory, applications, problems  

Microsoft Academic Search

Abstract In this review paper, kinematic theory of nonlinear resonances is introduced as a distinct research area in nonlinear physics. A com- pendious overview is given of speciflc features that can (or cannot) appear in the 2- and more dimensional dispersive systems due to non- linear resonances. Mathematical background and specially developed computational methods are brie?y presented as well as

Elena Kartashova

320

Shape resonances in molecular fields  

SciTech Connect

A shape resonance is a quasibound state in which a particle is temporarily trapped by a potential barrier (i.e., the shape of the potential), through which it may eventually tunnel and escape. This simple mechanism plays a prominent role in a variety of excitation processes in molecules, ranging from vibrational excitation by slow electrons to ionization of deep core levels by x-rays. Moreover, their localized nature makes shape resonances a unifying link between otherwise dissimilar circumstances. One example is the close connection between shape resonances in electron-molecule scattering and in molecular photoionization. Another is the frequent persistence of free-molecule shape resonant behavior upon adsorption on a surface or condensation into a molecular solid. The main focus of this article is a discussion of the basic properties of shape resonances in molecular fields, illustrated by the more transparent examples studied over the last ten years. Other aspects to be discussed are vibrational effects of shape resonances, connections between shape resonances in different physical settings, and examples of shape resonant behavior in more complex cases, which form current challenges in this field.

Dehmer, J.L.

1984-01-01

321

Resonance of metallic wire structures  

Microsoft Academic Search

Metallic wire structures form a common class of physical systems. We illustrate how to understand the general physics of the wire systems with a specific example, the split ring resonantor. We derived simple polynomial equations to determine the entire resonance spectra of split ring structures, which can be analytically solved in the limit of narrow wires. A resonance spectrum very

Lei Zhou; Y. Zhang; Siu Tat Chui

2008-01-01

322

Electromechanical Resonators from Graphene Sheets  

Microsoft Academic Search

Nanoelectromechanical systems were fabricated from single- and multilayer graphene sheets by mechanically exfoliating thin sheets from graphite over trenches in silicon oxide. Vibrations with fundamental resonant frequencies in the megahertz range are actuated either optically or electrically and detected optically by interferometry. We demonstrate room-temperature charge sensitivities down to 8 × 10–4 electrons per root hertz. The thinnest resonator consists

J. Scott Bunch; Arend M. Van der Zande; Scott S. Verbridge; Ian W. Frank; David M. Tanenbaum; Jeevak M. Parpia; Harold G. Craighead; Paul L. McEuen

2007-01-01

323

Plasmon resonance in a nanosphere  

Microsoft Academic Search

The phenomenon of plasmon resonance in a nanosphere and a nanospheroid is considered. As is known, this phenomenon does not\\u000a depend explicitly on the size of these nanoparticles. However, it is shown that, actually, the resonance conditions are determined\\u000a by the diameter of the nanosphere and by the length of the major axis of the nanospheroid.

V. S. Zuev; A. V. Frantsesson; D. V. Vlasov; G. Ya. Zueva

2004-01-01

324

Design of Microwave Dielectric Resonators  

Microsoft Academic Search

The resonant frequencies for the fundamental modes in circular cylindrical and rectangular parallelopiped high dielectric resonators have been calculated by computer for a range of values of physical dimensions and relative dielectric constant. The frequency range extends from zero to 50 kMc\\/s, the relative dielectric constant from 50 to 1800, and physical dimensions from zero to 500 roils. Results are

J. C. Sethares; S. J. Naumann

1966-01-01

325

Whispering Gallery Mode Optomechanical Resonator  

NASA Technical Reports Server (NTRS)

Great progress has been made in both micromechanical resonators and micro-optical resonators over the past decade, and a new field has recently emerged combining these mechanical and optical systems. In such optomechanical systems, the two resonators are strongly coupled with one influencing the other, and their interaction can yield detectable optical signals that are highly sensitive to the mechanical motion. A particularly high-Q optical system is the whispering gallery mode (WGM) resonator, which has many applications ranging from stable oscillators to inertial sensor devices. There is, however, limited coupling between the optical mode and the resonator s external environment. In order to overcome this limitation, a novel type of optomechanical sensor has been developed, offering great potential for measurements of displacement, acceleration, and mass sensitivity. The proposed hybrid device combines the advantages of all-solid optical WGM resonators with high-quality micro-machined cantilevers. For direct access to the WGM inside the resonator, the idea is to radially cut precise gaps into the perimeter, fabricating a mechanical resonator within the WGM. Also, a strategy to reduce losses has been developed with optimized design of the cantilever geometry and positions of gap surfaces.

Aveline, David C.; Strekalov, Dmitry V.; Yu, Nan; Yee, Karl Y.

2012-01-01

326

Basics of Resonance Chiral Theory  

SciTech Connect

We review the main components that have to be considered, within Resonance Chiral Theory, in the study of processes whose dynamics is dominated by hadron resonances. We show its application in the study of the {tau}{yields}{pi}{pi}{pi}{nu}{sub {tau}} decay.

Portoles, J. [Instituto de Fisica Corpuscular, IFIC, CSIC-Universitat de Valencia, Edifici d'Instituts de Paterna, Apt. Correus 22085, E-46071 Valencia (Spain)

2010-12-28

327

Improved Ring-Supported Resonators.  

National Technical Information Service (NTIS)

We have investigated some improved ring-supported (r-s) resonators. These resonators show promise of providing high precision frequencies for a wide temperature range and static and dynamic forces encountered in the field. In this paper, we report the exp...

M. Nakazawa H. Ito

1982-01-01

328

Magma Energy Extraction  

SciTech Connect

The rate at which energy can be extracted from crustal magma bodies has an important influence on the economic viability of the magma energy concept. Open heat exchanger systems where fluid is circulated through solidified magma offer the promise of high energy extraction rates. This concept was successfully demonstrated during experiments in the molten zone of Kilauea Iki lava lake. Ongoing research is directed at developing a fundamental understanding of the establishment and long term operation of open systems in a crustal magma body. These studies show that magma solidifying around a cooled borehole will be extensively fractured and form a permeable medium through which fluid can be circulated. Numerical modeling of the complete magma energy extraction process predicts that high quality thermal energy can be delivered to the wellhead at rates that will produce from 25 to 30 MW electric. 10 figs., 10 refs.

Dunn, J.C.; Ortega, A.; Hickox, C.E.; Chu, T.Y.; Wemple, R.P.; Boehm, R.F.

1987-01-20

329

Thermal Modifications in Softwood Studied by FT?IR and UV Resonance Raman Spectroscopies  

Microsoft Academic Search

Scots pine planks were heat?treated under steam in a temperature range of 100–240°C at every 20°C. Changes in chemical structure of the wood samples were examined with UV resonance Raman (UVRR) and Fourier transform infrared (FT?IR) spectroscopies. Prior to the FT?IR and UVRR analysis, the heartwood part of wood samples were ground and extracted with acetone. Both the extracts and

Mari Nuopponen; Tapani Vuorinen; Saila Jämsä; Pertti Viitaniemi

2005-01-01

330

Delta connected resonant snubber circuit  

DOEpatents

A delta connected, resonant snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the dc supply voltage through the main inverter switches and the auxiliary switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter. 36 figs.

Lai, J.S.; Peng, F.Z.; Young, R.W. Sr.; Ott, G.W. Jr.

1998-01-20

331

Delta connected resonant snubber circuit  

DOEpatents

A delta connected, resonant snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the dc supply voltage through the main inverter switches and the auxiliary switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter.

Lai, Jih-Sheng (Knoxville, TN); Peng, Fang Zheng (Oak Ridge, TN); Young, Sr., Robert W. (Oak Ridge, TN); Ott, Jr., George W. (Knoxville, TN)

1998-01-01

332

Transverse-longitudinal integrated resonator  

DOEpatents

A transverse-longitudinal integrated optical resonator (TLIR) is disclosed which includes a waveguide, a first and a second subwavelength resonant grating in the waveguide, and at least one photonic band gap resonant structure (PBG) in the waveguide. The PBG is positioned between the first and second subwavelength resonant gratings. An electro-optic waveguide material may be used to permit tuning the TLIR and to permit the TLIR to perform signal modulation and switching. The TLIR may be positioned on a bulk substrate die with one or more electronic and optical devices and may be communicably connected to the same. A method for fabricating a TLIR including fabricating a broadband reflective grating is disclosed. A method for tuning the TLIR's transmission resonance wavelength is also disclosed.

Hutchinson, Donald P [Knoxville, TN; Simpson, Marcus L [Knoxville, TN; Simpson, John T [Knoxville, TN

2003-03-11

333

Oil shale extraction process  

SciTech Connect

Hydrocarbon liquids are recovered from kerogen-containing oil shale by treating the oil shale with gaseous ammonia or a gaseous aliphatic amine prior to or during contact of the oil shale with an organic solvent. The hydrocarbon liquids thus extracted from the oil shale are then recovered from the solvent. The gaseous treatment step will normally take place at a temperature between about 500/sup 0/ F. and about 800/sup 0/ F. and at a pressure between about 200 psig and about 1000 psig. Preferably, the kerogen-containing oil shale will be treated with the ammonia or other gas prior to the extraction step.

Baset, Z.H.

1984-01-31

334

Supercritical fluid extraction  

DOEpatents

A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated or lipophilic crown ether or fluorinated dithiocarbamate. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.

Wai, Chien M. (Moscow, ID); Laintz, Kenneth (Pullman, WA)

1994-01-01

335

An LTCC balanced-to-unbalanced extracted-pole bandpass filter with complex load  

Microsoft Academic Search

In this paper, the fundamental characteristics of a novel third-order RF balanced-to-unbalanced filter, namely, a balun filter, for integrated RF module applications are presented. This center-tapped transformer-based new device works concurrently as a balun, an extracted-pole bandpass filter, and a matching network. As coupled resonant tanks are employed to perform the balun type of operation, traditional coupled-resonator filter theory can

Lap Kun Yeung; Ke-Li Wu

2006-01-01

336

Antioxidant activities of uyaku (lindera strychnifolia) leaf extract: a natural extract used in traditional medicine.  

PubMed

Uyaku (Lindera strychnifolia, Sieb. et Zucc.) is used in traditional Asian medicine to treat stomach and renal diseases, neuralgia, rheumatism, and aging. In this study, the effects of lyophilized extracts on hydroxyl ((.)OH) and superoxide (O(2) (.-)) radicals were examined using an electron spin resonance (ESR) spectrometer with the spin trap, 5,5'-dimethyl-1-pyrroline-N-oxide. Inhibitory effects were assessed using the following reagents: for nitric oxide (NO(.)), the Griess reagent; for (Fe(2+) + H(2)O(2))-induced lipid peroxidation, 2-thiobarbituric acid; for (Fe(2+) + H(2)O(2))-induced protein carbonyl, 2,4-dinitrophenylhydrazine. Analysis of ESR data of the extracts indicated the direct (.)OH and O(2) (.-) scavenging. The extracts scavenged NO(.) in a dose-dependent manner, inhibited lipid peroxidation of linolenic acid, and protein carbonyl formation in bovine serum albumin. In conclusion, the Uyaku leaf hot-water extract has potent scavenging activity against reactive oxygen species and reactive nitrogen species, and effectively inhibited lipid peroxidation. These results might contribute to understanding age-associated or free radical-related diseases induced by excess reactive oxygen and also nitrogen species. PMID:18193108

Noda, Yasuko; Mori, Akitane

2007-09-01

337

Combination of matrix solid-phase dispersion extraction and direct on-line liquid chromatography-nuclear magnetic resonance spectroscopy-tandem mass spectrometry as a new efficient approach for the rapid screening of natural products: application to the total asterosaponin fraction of the starfish Asterias rubens.  

PubMed

A combination of matrix solid-phase dispersion extraction (MSPD) and LC-NMR-MS hyphenation is proposed as a rapid screening method of natural products for unknown compounds. In this report, this new analytical approach is applied for the first time. MSPD represents a significant simplification compared to classical extraction procedures and is thus an excellent complement to the fast and powerful LC-NMR-MS: MSPD yields extracts suitable for LC-NMR-MS in one simple preparation step, while LC-NMR-MS yields a wealth of information in one single chromatographic run. The suitability of this technique to characterise glycosidic compounds in the molecular mass range of 1200 to 1400 a.m.u. is demonstrated. The information on the number of exchangeable protons provided by an additional back-exchange experiment proved to be particularly valuable for structural elucidation. The possibility of semi-quantitative LC-NMR measurements through methyl signals H(3)-18 and 19 of the steroidal skeleton is demonstrated and is ensuingly used to provide relative quantitative data of the steroid oligosaccharide fraction. PMID:11403494

Sandvoss, M; Weltring, A; Preiss, A; Levsen, K; Wuensch, G

2001-05-11

338

Powered resonance tubes: resonance characteristics and actuation signal directivity  

NASA Astrophysics Data System (ADS)

The powered resonance tube (PRT) actuator and its variants are new developments in active flow control (AFC) technology. The PRT is attractive because it has no moving parts and can produce acoustic tones that have amplitudes greater than 150 dB over a large frequency bandwidth. The first part of this paper deals with the resonance characteristics of the PRT as a function of the operating parameters such as jet-to-tube spacing ( Sp), tube depth ( d), and nozzle pressure ratio (NPR). It was found that: (1) at low NPR (3.33), the PRT resonates at discrete combinations of spacing and depth. (2) Using theoretical estimates for predicting shock cell lengths, one could observe a correlation between the theoretical prediction for shock cell length and the spacing at which the PRT resonates. (3) At high NPR (4.29), for a fixed depth, the PRT resonates at virtually all spacings. (4) The frequency at which the PRT resonates remains approximately constant, regardless of spacing. The second part of the study focused on examining the directivity of the acoustic radiation from the PRT—significant for developing orientation strategies of the PRT with respect to the target flow in the end application. The directivity of the fundamental PRT tone and that of its harmonics were studied for a variety of resonance frequencies, both separately as well as cumulatively. It was found that the fundamental part of the actuation signal radiated predominantly in the downstream direction of the jet for low resonance frequencies. As the resonance frequency was increased from 3 to 12 kHz, the directivity changed from downstream of the jet to vertically upward, and finally upstream of the jet at the higher frequencies.

Sarpotdar, Shekhar; Raman, Ganesh; Cain, Alan B.

2005-12-01

339

System and Method for Regulating Resonant Inverters.  

National Technical Information Service (NTIS)

A technique is provided for direct digital phase control of resonant inverters based on sensing of one or more parameters of the resonant inverter. The resonant inverter control system includes a switching circuit for applying power signals to the resonan...

L. D. Stevanovic R. A. Zane

2004-01-01

340

Magnetic Resonance Detection Method and and Apparatus.  

National Technical Information Service (NTIS)

A method and apparatus is described for detecting magnetic resonance of a sample. The apparatus uses an exceptionally stable tunnel diode rf oscillator incorporating a LC reentrant cavity resonator. The method entails measuring a magnetic resonance of the...

C. T. Van Degrift D. B. Utton

1977-01-01

341

Magnetic Resonance Studies of Coal. Volume III.  

National Technical Information Service (NTIS)

Electron spin resonance (ESR) and Electron-Nuclear Double Resonance (ENDOR) techniques have been used to study natural radical centers in Alabama coals. Also Nuclear Magnetic Resonance (NMR) techniques have been used for a preliminary study of the hydroge...

I. Miyagawa C. Alexander

1981-01-01

342

Nonlinear optical whispering gallery mode resonators  

NASA Technical Reports Server (NTRS)

Whispering gallery mode (WGM) optical resonators comprising nonlinear optical materials, where the nonlinear optical material of a WGM resonator includes a plurality of sectors within the optical resonator and nonlinear coefficients of two adjacent sectors are oppositely poled.

Ilchenko, Vladimir (Inventor); Matsko, Andrey B. (Inventor); Savchenkov, Anatoliy (Inventor); Maleki, Lutfollah (Inventor)

2005-01-01

343

Electron Paramagnetic Resonance -- Nuclear Magnetic Resonance Three Axis Vector Magnetometer  

NASA Astrophysics Data System (ADS)

The Northrop Grumman Corporation is leveraging the technology developed for the Nuclear Magnetic Resonance Gyroscope (NMRG) to build a combined Electron Paramagnetic Resonance -- Nuclear Magnetic Resonance (EPR-NMR) magnetometer. The EPR-NMR approach provides a high bandwidth and high sensitivity simultaneous measurement of all three vector components of the magnetic field averaged over the small volume of the sensor's one vapor cell. This poster will describe the history, operational principles, and design basics of the EPR-NMR magnetometer including an overview of the NSD designs developed and demonstrated to date. General performance results will also be presented.

Bulatowicz, Michael; Clark, Philip; Griffith, Robert; Larsen, Michael; Mirijanian, James

2012-06-01

344

D- centers probed by resonant tunneling spectroscopy  

NASA Astrophysics Data System (ADS)

A donor-related resonance is observed in double-barrier resonant tunneling devices with Si donors incorporated in the quantum well. In high magnetic fields the resonance becomes dominant over the 1s resonance associated with the ground state of a single donor. The bias position of the donor resonance, its magnetic field dependence, and large amplitude indicate unambiguously that the resonance is due to tunneling through the ground state of a shallow donor with two bound electrons (D- level).

Lok, J. G. S.; Geim, A. K.; Maan, J. C.; Marmorkos, I.; Peeters, F. M.; Mori, N.; Eaves, L.; Foster, T. J.; Main, P. C.; Sakai, J. W.; Henini, M.

1996-04-01

345

ENGINEERING BULLETIN: SOLVENT EXTRACTION  

EPA Science Inventory

Solvent extraction does not destroy hazardous contaminants, but is a means of separating those contaminants from soils, sludges, and sediments, thereby reducing the volume of the hazardous material that must be treated. enerally it is used as one in a series of unit operations an...

346

Oil shale extraction process  

Microsoft Academic Search

Hydrocarbon liquids are recovered from kerogen-containing oil shale by treating the oil shale with gaseous ammonia or a gaseous aliphatic amine prior to or during contact of the oil shale with an organic solvent. The hydrocarbon liquids thus extracted from the oil shale are then recovered from the solvent. The gaseous treatment step will normally take place at a temperature

Baset

1984-01-01

347

The Tevatron Extraction Pulser  

Microsoft Academic Search

The Tevatron QXR (Quadrupole Extraction Regulator) power supply is a linear current pulser combined with a dc transistor regulator. The pulser produces programmable current pulses of up to 250 amps with a maximum duration of 12 ms and a maximum voltage drive of +200\\/-250 volts. Its fastest repetition rate is 1 Hz. Between pulses a single power transistor regulator maintains

H. Pfeffer

1985-01-01

348

Steerable Extraction Rocket.  

National Technical Information Service (NTIS)

The patent application relates to a steerable rocket motor for towing a load or extracting an aircrew member from a disabled aircraft, regardless of aircraft attitude or altitude. The rocket motor is formed from a hollow cylindrical thin walled casing con...

R. B. Dillinger J. W. Stone

1976-01-01

349

Automated document metadata extraction  

Microsoft Academic Search

Web documents are available in various forms, most of which do not carry additional semantics. This paper presents a model for general document metadata extraction. The model, which combines segmentation by keywords and pattern matching techniques, was implemented using PHP, MySQL, JavaScript and HTML. The system was tested with 40 randomly selected PDF documents (mainly theses). An evaluation of the

Bolanle Adefowoke Ojokoh; Olumide Sunday Adewale; Samuel Oluwole Falaki

2009-01-01

350

Lasing from active optomechanical resonators  

PubMed Central

Planar microcavities with distributed Bragg reflectors (DBRs) host, besides confined optical modes, also mechanical resonances due to stop bands in the phonon dispersion relation of the DBRs. These resonances have frequencies in the 10- to 100-GHz range, depending on the resonator’s optical wavelength, with quality factors exceeding 1,000. The interaction of photons and phonons in such optomechanical systems can be drastically enhanced, opening a new route towards the manipulation of light. Here we implemented active semiconducting layers into the microcavity to obtain a vertical-cavity surface-emitting laser (VCSEL). Thereby, three resonant excitations—photons, phonons and electrons—can interact strongly with each other providing modulation of the VCSEL laser emission: a picosecond strain pulse injected into the VCSEL excites long-living mechanical resonances therein. As a result, modulation of the lasing intensity at frequencies up to 40?GHz is observed. From these findings, prospective applications of active optomechanical resonators integrated into nanophotonic circuits may emerge.

Czerniuk, T.; Bruggemann, C.; Tepper, J.; Brodbeck, S.; Schneider, C.; Kamp, M.; Hofling, S.; Glavin, B. A.; Yakovlev, D. R.; Akimov, A. V.; Bayer, M.

2014-01-01

351

Nuclear magnetic resonance contrast agents  

DOEpatents

A family of contrast agents for use in magnetic resonance imaging and a method of enhancing the contrast of magnetic resonance images of an object by incorporating a contrast agent of this invention into the object prior to forming the images or during formation of the images. A contrast agent of this invention is a paramagnetic lanthanide hexaazamacrocyclic molecule, where a basic example has the formula LnC.sub.16 H.sub.14 N.sub.6. Important applications of the invention are in medical diagnosis, treatment, and research, where images of portions of a human body are formed by means of magnetic resonance techniques.

Smith, Paul H. (Los Alamos, NM); Brainard, James R. (Los Alamos, NM); Jarvinen, Gordon D. (Los Alamos, NM); Ryan, Robert R. (Los Alamos, NM)

1997-01-01

352

Biological magnetic resonance: vol. 5  

SciTech Connect

This book discusses magnetic resonance techniques (NMR and ESR) as applied to biochemical research. Topics considered include the applications of carbon-13 NMR spectroscopy in investigations of metabolic pathways in vivo, the use of nitrogen-15 NMR in studies of systems of biological interest, phosphorus-31 NMR investigations of enzyme systems, the principles and state-of-the-art advances in the use of oxygen isotopes in phosphorus-31 and oxygen-17 NMR studies of biophosphates, and electron spin resonance and nuclear magnetic resonance studies of lipid-protein interactions in membranes.

Berliner, L.J.; Reuben, J.

1983-01-01

353

Mechanical resonant immunospecific biological detector  

NASA Astrophysics Data System (ADS)

We have demonstrated high-sensitivity detection of bacteria using an array of bulk micromachined resonant cantilevers. The biological sensor is a micromechanical oscillator that consists of an array of silicon-nitride cantilevers with an immobilized antibody layer on the surface of the resonator. Measured resonant frequency shift as a function of the additional cell loading was observed and correlated to the mass of the specifically bound Escherichia coli O157:H7 cells. Deposition and subsequent detection of E. coli cells was achieved under ambient conditions.

Ilic, B.; Czaplewski, D.; Craighead, H. G.; Neuzil, P.; Campagnolo, C.; Batt, C.

2000-07-01

354

Sound-resonance hydrogen sensor  

NASA Astrophysics Data System (ADS)

A hydrogen sensor is reported in which a small piezoelectric-sound-resonance-cavity (PSRC) is used as the sensing element. Detection utilizes sound resonance and acoustic property differences between H2 and air as a sensing mechanism. Changes in H2 concentration result in a shift of the sound-resonance state of the PSRC. Preliminary experiments have demonstrated a sensitivity limit of 8 ppm, a fast response time ~1.5 second, and detection capabilities over a broad concentration range 10-5

Dong, Shuxiang; Bai, Feiming; Li, Jiefang; Viehland, Dwight

2003-06-01

355

Nuclear magnetic resonance contrast agents  

DOEpatents

A family of contrast agents for use in magnetic resonance imaging and a method of enhancing the contrast of magnetic resonance images of an object by incorporating a contrast agent of this invention into the object prior to forming the images or during formation of the images. A contrast agent of this invention is a paramagnetic lanthanide hexaazamacrocyclic molecule, where a basic example has the formula LnC{sub 16}H{sub 14}N{sub 6}. Important applications of the invention are in medical diagnosis, treatment, and research, where images of portions of a human body are formed by means of magnetic resonance techniques. 10 figs.

Smith, P.H.; Brainard, J.R.; Jarvinen, G.D.; Ryan, R.R.

1997-12-30

356

Multiple resonant railgun power supply  

DOEpatents

A multiple repetitive resonant railgun power supply provides energy for repetitively propelling projectiles from a pair of parallel rails. A plurality of serially connected paired parallel rails are powered by similar power supplies. Each supply comprises an energy storage capacitor, a storage inductor to form a resonant circuit with the energy storage capacitor and a magnetic switch to transfer energy between the resonant circuit and the pair of parallel rails for the propelling of projectiles. The multiple serial operation permits relatively small energy components to deliver overall relatively large amounts of energy to the projectiles being propelled.

Honig, Emanuel M. (Los Alamos, NM); Nunnally, William C. (Los Alamos, NM)

1988-01-01

357

Infrared Extraction Change for the NSLS-II Storage Ring  

SciTech Connect

The short- and long-range wakepotentials have been studied for the design of the infrared (IR) extraction chamber with large full aperture: 67mm vertical and 134mm horizontal. The IR-chamber will be installed within a 2.6m long wide-gap bending magnet with 25m bend radius. Due to the large bend radius it is difficult to separate the light from the electron trajectory. The required parameters of the collected IR radiation at the extraction mirror are {approx}50mrad horizontal and {approx}25mrad vertical (full radiation opening angles). If the extraction mirror is seen by the beam, resonant modes are generated in the chamber. In this paper, we present the detailed calculated impedance for the design of the far-IR chamber, and show that placing the extraction mirror in the proper position eliminates the resonances. In this case, the impedance reduces to that of a simple tapered structure, which is acceptable in regard to its impact on the electron beam.

Blednykh,A.; Carr, L.; Coburn, D.; Krinsky, S.

2009-05-04

358

A resonant wave theory  

NASA Astrophysics Data System (ADS)

Analysis is used to show that a solution of the Navier Stokes equations can be computed in terms of wave-like series, which are referred to as waves below. The mean flow is a wave of infinitely long wavelength and period; laminar flows contain only one wave, i.e. the mean flow. With a supercritical instability, there are a mean flow, a dominant wave and its harmonics. Under this scenario, the amplitude of the waves is determined by linear and nonlinear terms. The linear case is the target of flow-instability studies. The nonlinear case involves energy transfer among the waves satisfying resonance conditions so that the wavenumbers are discrete, form a denumerable set, and are homeomorphic to Cantor's set of rational numbers. Since an infinite number of these sets can exist over a finite real interval, nonlinear Navier Stokes equations have multiple solutions and the initial conditions determine which particular set will be excited. Consequently, the influence of initial conditions can persist forever. This phenomenon has been observed for Couette Taylor instability, turbulent mixing layers, wakes, jets, pipe flows, etc. This is a commonly known property of chaos.

Yao, Lun-Shin

1999-09-01

359

Designing dielectric resonators on substrates: combining magnetic and electric resonances.  

PubMed

High-performance integrated optics, solar cells, and sensors require nanoscale optical components at the surface of the device, in order to manipulate, redirect and concentrate light. High-index dielectric resonators provide the possibility to do this efficiently with low absorption losses. The resonances supported by dielectric resonators are both magnetic and electric in nature. Combined scattering from these two can be used for directional scattering. Most applications require strong coupling between the particles and the substrate in order to enhance the absorption in the substrate. However, the coupling with the substrate strongly influences the resonant behavior of the particles. Here, we systematically study the influence of particle geometry and dielectric environment on the resonant behavior of dielectric resonators in the visible to near-IR spectral range. We show the key role of retardation in the excitation of the magnetic dipole (MD) mode, as well as the limit where no MD mode is supported. Furthermore, we study the influence of particle diameter, shape and substrate index on the spectral position, width and overlap of the electric dipole (ED) and MD modes. Also, we show that the ED and MD mode can selectively be enhanced or suppressed using multi-layer substrates. And, by comparing dipole excitation and plane wave excitation, we study the influence of driving field on the scattering properties. Finally, we show that the directional radiation profiles of the ED and MD modes in resonators on a substrate are similar to those of point-dipoles close to a substrate. Altogether, this work is a guideline how to tune magnetic and electric resonances for specific applications. PMID:24216852

van de Groep, J; Polman, A

2013-11-01

360

Ferromagnetic Resonance Imaging with Magnetic Resonance Force Microscopy  

NASA Astrophysics Data System (ADS)

Magnetic resonance force microscopy achieves very high resolution three-dimensional imaging capabilities of magnetic resonance imaging by taking advantage of very high sensitivity mechanical force detection. This enables non-contacting, microscopic studies and imaging of a broad range of materials. As a consequence of the strong interactions between spins, the assumptions underlying conventional MRI are not applicable to FMR imaging. However, using a new approach to localizing the resonant volume in an FMR measurement founded on the strong, nonuniform magnetic field of the micromagnetic probe tip, we have demonstrated scanned probe Ferromagnetic Resonance (FMR) imaging [1]. The scanned probe FMR images obtained in patterned ferromagnetic films are well explained by detailed numerical modeling. In addition to illuminating the mechanisms underlying localized FMR, the model provides the basis for submicron scanned probe FMR imaging of films and buried ferromagnetic elements. This work was supported by the U.S. Department of Energy through Grant No. DE-FG02-03ER46054. [1] ``Local Ferromagnetic Resonance Imaging with Magnetic Resonance Force Microscopy,'' Yu. Obukhov, D.V. Pelekhov, J. Kim, P. Banerjee, I. Martin, E. Nazaretski, R. Movshovich, S. An, T.J. Gramila, S. Batra, and P. C. Hammel, Phys. Rev. Lett. 100(19), 197601 (2008).

Pelekhov, Denis

2009-03-01

361

Resonance IR: A Coherent Multidimensional Analogue of Resonance Raman.  

PubMed

This work demonstrates the use of triply resonant sum frequency (TRSF) spectroscopy as a "resonance IR" analogue to resonance Raman spectroscopy. TRSF is a four-wave-mixing process where three lasers with independent frequencies interact coherently with a sample to generate an output at their triple summation frequency. The first two lasers are in the infrared and result in two vibrational excitations, while the third laser is visible and induces a two-quantum anti-Stokes resonance Raman transition. The signal intensity grows when the laser frequencies are all in resonance with coupled vibrational and electronic states. The method therefore provides electronic enhancement of IR-active vibrational modes. These modes may be buried beneath solvent in the IR spectrum and also be Raman-inactive and therefore inaccessible by other techniques. The method is presented on the centrosymmetric complex copper phthalocyanine tetrasulfonate. In this study, the two vibrational frequencies were scanned across ring-breathing modes, while the visible frequency was left in resonance with the copper phthalocyanine tetrasulfonate Q band, resulting in a two-dimensional infrared plot that also reveals coupling between vibrational states. TRSF has the potential to be a very useful probe of structurally similar biological motifs such as hemes, as well as synthetic transition-metal complexes. PMID:24707979

Boyle, Erin S; Neff-Mallon, Nathan A; Handali, Jonathan D; Wright, John C

2014-05-01

362

Graph-Cut Energy Minimization for Object Extraction in MRCP Medical Images  

Microsoft Academic Search

Bile duct identification and extraction in magnetic resonance cholangiopancreatography (MRCP) images, is a necessary step\\u000a in the development of computer-aided diagnosis systems using such images. MRCP is becoming the de facto modality in the diagnosis\\u000a of biliary diseases and even in the pre-surgical workup for liver transplants. The energy minimization graph-cut method is\\u000a a proven technique in the extraction of

Rajasvaran Logeswaran; Dongho Kim; Jungwhan Kim; Keechul Jung; Bundo Song

363

Beam current enhancement of microwave plasma ion source utilizing double-port rectangular cavity resonator  

SciTech Connect

Microwave plasma ion source with rectangular cavity resonator has been examined to improve ion beam current by changing wave launcher type from single-port to double-port. The cavity resonators with double-port and single-port wave launchers are designed to get resonance effect at TE-103 mode and TE-102 mode, respectively. In order to confirm that the cavities are acting as resonator, the microwave power for breakdown is measured and compared with the E-field strength estimated from the HFSS (High Frequency Structure Simulator) simulation. Langmuir probe measurements show that double-port cavity enhances central density of plasma ion source by modifying non-uniform plasma density profile of the single-port cavity. Correspondingly, beam current from the plasma ion source utilizing the double-port resonator is measured to be higher than that utilizing single-port resonator. Moreover, the enhancement in plasma density and ion beam current utilizing the double-port resonator is more pronounced as higher microwave power applied to the plasma ion source. Therefore, the rectangular cavity resonator utilizing the double-port is expected to enhance the performance of plasma ion source in terms of ion beam extraction.

Lee, Yuna; Park, Yeong-Shin; Jo, Jong-Gab; Yang, J. J.; Hwang, Y. S. [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)

2012-02-15

364

Comment on ``Magnetic Resonance Spectroscopy Identifies Neural Progenitor Cells in the Live Human Brain''  

Microsoft Academic Search

Manganas et al. (Reports, 9 November 2007, p. 980) reported the discovery of a biomarker specific for neural progenitor cells detectable using magnetic resonance spectroscopy. A new algorithm was developed to extract the biomarker from noisy in vivo data. We question how this algorithm was validated, because the biomarker overlaps with peaks from nonspecific lipid signals.

Jacobus F. A. Jansen; John D. Gearhart; Jeff W. M. Bulte

2008-01-01

365

Knowledge-based extraction of cerebral vasculature from anatomical MRI  

NASA Astrophysics Data System (ADS)

A vessel extraction approach is presented that permits visualization of the cerebral vasculature in 3D from anatomical proton density (PD) weighted magnetic resonance imaging (MRI) volumes. The approach presented utilizes general knowledge about the shape and size of the cerebral vasculature and is divided into multi-scale vessel enhancement filtering, centre-line extraction, and surface modeling. To improve the discrimination between blood vessels and other tissue a multi-scale filtering method that enhances tubular structures is used as a pre-processing step. Centre-line extraction is applied to roughly estimate the centre-line of the vasculature involving both segmentation and skeletonization. The centre-line is used to initialize an active contour modeling process where cylinders are used to model the 3D surface of the blood vessels. The accuracy and robustness of the vessel extraction approach have been demonstrated on both simulated and real data (1mm3 voxels). On simulated data, the mean error of the estimated radii was found to be less than 0.4mm. On real data, the vasculature was successfully extracted from 20 MRI data sets using the same input parameters. An expert found the extracted vessel surfaces to coincide with the vessel walls in the data. Results from CTA data indicate that the approach will work successfully with other imaging modalities as well.

Oestergaard, Lasse R.; Larsen, Ole V.; Haase, Jens; Van Meer, Frederick; Evans, Alan C.; Collins, D. Louis

2001-07-01

366

Laboratory Measurements of Subsynchronous Resonance.  

National Technical Information Service (NTIS)

A selection of results obtained from a laboratory system specially designed to investigate subsynchronous resonance are presented. This laboratory system was designed to model as closely as possible the nuclear powered turbo-generators to be installed at ...

D. J. N. Limebeer R. G. Harley M. A. Lahoud H. L. Nattrass

1980-01-01

367

Relativistic Broadening Near Cyclotron Resonance.  

National Technical Information Service (NTIS)

Relativistic broadening of absorption (or emission) lines near cyclotron resonance in a warm plasma is investigated using the linearized relativistic Vlasov-Maxwell system. The unperturbed state is assumed to be isotropic, but not necessarily Maxwellian. ...

K. Imre H. Weitzner

1983-01-01

368

Subharmonic growth by parametric resonance  

NASA Astrophysics Data System (ADS)

An experimental investigation is conducted in order to quantify the nonlinear and parametric resonance mechanisms that are associated with the subharmonic growth in the transition to turbulence in plane mixing layers. Higher-order digital statistical analysis techniques are used to investigate the nonlinear and parametric mechanisms responsible for the energy transfer to the subharmonic. The results show that the dominant interaction is a parametric resonance mechanism between the fundamental and the subharmonic modes which leads to a pronounced growth of the subharmonic. Measurements also indicate that the fundamental, besides interacting with the subharmonic, is also engaged in redistributing its energy to the other Fourier components of the flow via nonlinear three-wave interactions. Local wavenumber measurements verify that frequency-wavenumber resonance matching conditions exist between the fundamental and subharmonic in the region where the subharmonic gains its energy by parametric resonance. The results are in general agreement with theoretical models by Kelly (1967), and Monkewitz (1988) on subharmonic growth.

Hajj, M. R.; Miksad, R. W.; Powers, E. J.

1992-03-01

369

Morphological resonances for multicomponent immunoassays  

NASA Astrophysics Data System (ADS)

An immunoassay technique capable of detecting and identifying a number of species of microorganisms in a single analysis is described. The method uses optical-resonance size discrimination of microspheres to identify antibodies to which stained microorganisms are bound.

Whitten, W. B.; Shapiro, M. J.; Ramsey, J. M.; Bronk, B. V.

1995-06-01

370

Chemically Polished High Frequency Resonators.  

National Technical Information Service (NTIS)

The upper frequency limit of quartz resonators is determined by the physical properties of quartz and restrictions imposed by processing techniques. More often than not, the processing limitations are reached long before the physical limitations. Mechanic...

W. P. Hanson

1983-01-01

371

Lunar hydrogen extraction  

NASA Technical Reports Server (NTRS)

This paper examines the power and mass requirements of a lunar hydrogen extraction plant producing five metric tons of hydrogen per year. These power and mass requirements are based upon experimental work that determined gaseous hydrogen release rates from lunar samples at various heating rates and temperatures. An optimum heating temperature and rate can be selected to minimize the processing plant's power and mass requirements. The impact of thermal recovery on the power and mass requirements is studied, as is the use of nuclear waste heat for processing the regolith. In addition, the potential of using the extracted hydrogen in the form of methane as a propellant for a Lunar Excursion Vehicle is examined.

Snaufer, M. J.; Alred, J. W.

1991-01-01

372

Extracting concentrated guided light.  

PubMed

The maximum concentration of radiation is proportional to the square of the refractive index of the medium in which it propagates. A medium with a high refractive index can also serve as a lightguide for concentrated radiation. However, if concentrated radiation is extracted from one medium, with a high refractive index, to another, whose index is lower (e.g., from fused silica into air), part of the radiation may be lost because of the total internal reflection at the interface. We present polygonal shapes suitable for efficient extraction of the concentrated radiation in a controllable way, without increasing the cross-section area (or diameter) of the lightguide. It is shown analytically and experimentally that the use of a secondary concentrator, followed by such a light extractor, both having a high refractive index, can provide considerably more power to a solar receiver with a specific aperture. PMID:18253285

Ries, H; Segal, A; Karni, J

1997-05-01

373

Ion extraction system optimization  

SciTech Connect

The extraction of a beam from ion sources is dominated by the strong space charge of the beam, due to the initial low speed of the particles. Several mathematical and computational issues are discussed, with reference to a diode design based on thin anode lens effect, yielding a parallel beam at its exit, which is the first block of many high current electrostatic accelerators. Perturbation to uniform current density are analyzed. Effect of a thick anode lens is also treated.

Cavenago, Marco [INFN-LNL, v.le dell'Universita n 2, I-35020, Legnaro (Italy)

2013-07-18

374

Neural Network Knowledge Extraction  

Microsoft Academic Search

The usage of ANNs in "safety-critical" domains, which include theeconomic and financial applications, is hindered by their "black box"- type approach,which makes it difficult to verify and debug software that includes ANNcomponents. Significant advantages can be gained by combining the symbolic knowledgeof a domain theory (DT), with the empirical sub-symbolic knowledge stored in an ANNtrained on examples. Rule extraction adds

Alexandra I. Cristea; Paul D. Cristea; Toshio Okamoto

1997-01-01

375

Solid phase extraction membrane  

DOEpatents

A wet-laid, porous solid phase extraction sheet material that contains both active particles and binder and that possesses excellent wet strength is described. The binder is present in a relatively small amount while the particles are present in a relatively large amount. The sheet material is sufficiently strong and flexible so as to be pleatable so that, for example, it can be used in a cartridge device.

Carlson, Kurt C [Nashville, TN; Langer, Roger L [Hudson, WI

2002-11-05

376

Coal Extraction - Environmental Prediction  

USGS Publications Warehouse

Coal from the Appalachian region has supplied energy to the Nation for more than 200 years. Appalachian coal fueled America through a civil war and helped win two world wars. Appalachian coal has also provided fuel for keeping America warm in the winter and cool in the summer and has served as the basis for the steel, automobile, organic chemicals, chlorine, and aluminum industries. These benefits have not come without environmental costs, however. Coal extraction and utilization have had significant environmental impacts.

Cecil, C. Blaine; Tewalt, Susan J.

2002-01-01

377

Prospex: Protocol Specification Extraction  

Microsoft Academic Search

Protocol reverse engineering is the process of extracting application-level specifications for network protocols. Such specifications are very useful in a number of security-related contexts, for example, to perform deep packet inspection and black-box fuzzing, or to quickly understand custom botnet command and control (C&C) channels. Since manual re- verse engineering is a time-consuming and tedious process, a number of systems

Paolo Milani Comparetti; Gilbert Wondracek; Christopher Kruegel; Engin Kirda

2009-01-01

378

[Skeleton extractions and applications].  

SciTech Connect

This paper focuses on the extraction of skeletons of CAD models and its applications in finite element (FE) mesh generation. The term 'skeleton of a CAD model' can be visualized as analogous to the 'skeleton of a human body'. The skeletal representations covered in this paper include medial axis transform (MAT), Voronoi diagram (VD), chordal axis transform (CAT), mid surface, digital skeletons, and disconnected skeletons. In the literature, the properties of a skeleton have been utilized in developing various algorithms for extracting skeletons. Three main approaches include: (1) the bisection method where the skeleton exists at equidistant from at least two points on boundary, (2) the grassfire propagation method in which the skeleton exists where the opposing fronts meet, and (3) the duality method where the skeleton is a dual of the object. In the last decade, the author has applied different skeletal representations in all-quad meshing, hex meshing, mid-surface meshing, mesh size function generation, defeaturing, and decomposition. A brief discussion on the related work from other researchers in the area of tri meshing, tet meshing, and anisotropic meshing is also included. This paper concludes by summarizing the strengths and weaknesses of the skeleton-based approaches in solving various geometry-centered problems in FE mesh generation. The skeletons have proved to be a great shape abstraction tool in analyzing the geometric complexity of CAD models as they are symmetric, simpler (reduced dimension), and provide local thickness information. However, skeletons generally require some cleanup, and stability and sensitivity of the skeletons should be controlled during extraction. Also, selecting a suitable application-specific skeleton and a computationally efficient method of extraction is critical.

Quadros, William Roshan

2010-05-01

379

Magnetostatic wave resonators and oscillators  

Microsoft Academic Search

The purpose of this paper is to describe the current status of magnetostatic wave tunable resonators operating between 2 and 12GHz and their applications to microwave oscillators, the wave propagating in a pure yttrium-iron-garnet epi-layer. The first section deals with magnetostatic surface wave (MSSW) resonators consisting of a pair of reflective grooved gratings and two microstrip-transducers set between the gratings.

J. P. Castéra; P. Hartemann

1985-01-01

380

Resonant ultrasonic attenuation in emulsions  

NASA Astrophysics Data System (ADS)

We report the achievement of scattering resonant emulsions devoted to the frequency-control of acoustic attenuation in the megahertz range. By means of robotics, we produced highly monodisperse, in both size and shape, fluorinated-oil droplet suspensions, providing experimental evidence of several Mie scattering resonances. Ultrasonic experiments performed in such complex media are compared, with an excellent quantitative agreement, to theoretical predictions derived within the framework of the independent scattering approximation.

Brunet, Thomas; Mascaro, Benoit; Poncelet, Olivier; Aristégui, Christophe; Raffy, Simon; Mondain-Monval, Olivier; Leng, Jacques

2013-08-01

381

Field Line Resonance at Mercury  

NASA Astrophysics Data System (ADS)

When an incident compressional wave propagates across an Alfven velocity gradient in multi-fluid plasmas, the compressional wave can couple with the Alfven resonance for lower frequency and/or the ion-ion hybrid (IIH) resonance for higher frequency. Recently, a wave simulation in electron-hydrogen-sodium plasmas suggested that the field line resonance at Mercury is expected to occur when the IIH and/or Alfven resonance conditions are satisfied. However, the relative efficiency of wave energy absorption at these resonances has not been studied in the context of Mercury's magnetosphere. To understand the efficiency of wave absorption, we evaluate absorption coefficients (A) at the IIH and Alfven resonances for variable concentrations of sodium, ?Na = NNa / Ne, where Nj is number density for particle species j, and azimuthal (p) and field-aligned (q) wave numbers. Our results show that (1) The maximum values of absorption are up to 100 %; (2). The values of ?Na, where A has a maximum, increase as q increases; (3) The value of p where A has a maximum is almost same for different q values, but the width p of the absorption window become wider as q increases; and (4) When q increases, A oscillates in ?Na. These results suggest that the mode conversion efficiency is sensitive to the azimuthal and field aligned wave numbers and heavy ion concentration rates. Therefore when MESSENGER enters orbit around Mercury and detects field-line resonances, it is expected that discontinuities in the resonance frequencies could be observed in the radial direction.

Lee, K.; Kim, E.; Johnson, J.

2010-12-01

382

Impurity resonances in carbon nanotubes  

NASA Astrophysics Data System (ADS)

Analytical expressions are derived for the self-energies of electrons in carbon nanotubes while interacting with impurity atoms. Results are reported for armchair and zigzag tubes. It is shown that the impurity causes a bound electron donor or acceptor state beneath every semiconductor band edge. If the tubes are metallic, these bound states become resonance states. The analytical formulas give resonance shapes in good agreement with former numerical calculations.

Mahan, G. D.

2004-03-01

383

Electromagnetic properties of baryon resonances  

NASA Astrophysics Data System (ADS)

Longitudinal and transverse transition form factors for most of the four-star nucleon resonances have been obtained from high-quality cross section data and polarization observables measured at MAMI, ELSA, BATES, GRAAL and CEBAF. As an application, we further show how the transition form factors can be used to obtain empirical transverse charge densities. Contour plots of the thus derived densities are shown and compared for the Roper and S11 nucleon resonances.

Tiator, Lothar

2013-10-01

384

Giant resonances in 112Sn  

NASA Astrophysics Data System (ADS)

The isoscalar giant quadrupole resonance and the giant monopole resonance in 112Sn were identified at Ex=13.3+/-0.2 MeV and 15.7+/-0.3 MeV, respectively, using small angle inelastic scattering of 129 MeV alpha particles. The nuclear incompressibility parameters for the volume term (Kvol), the surface term (Ksurf), and the symmetry term (Ksym) were determined including 112Sn.

Lui, Y.-W.; Bogucki, P.; Bronson, J. D.; Youngblood, D. H.; Garg, U.

1984-07-01

385

Laterally Driven Polysilicon Resonant Microstructures  

Microsoft Academic Search

Interdigitated finger (comb) structures are demonstrated to be effective for exciting electro- statically the resonance of polysilicon microstruc- tures parallel to the plane of the substrate. Linear plates suspended by a folded-cantilever truss and torsional plates suspended by spiral and serpen- tine springs are fabricated from a 2\\/~m-thick phosphorus-doped low-pressure chemical-vapor- deposited (LPCVD) polysilicon film. Resonance is observed visually, with

WILLIAM C. TANG; TU-CUONG H. NGUYEN; ROGER T. HOWE

1989-01-01

386

Surface-micromachined resonant accelerometer  

Microsoft Academic Search

This paper discusses the design and testing of a resonant accelerometer developed for integrated surface-micromachining processes. First- and second-generation designs are presented. The sensors use leverage mechanisms to transfer force from a proof mass to double-ended tuning fork (DETF) resonators used as force transducers. Each fork forms the basis of an integrated oscillator to provide the output waveforms. The DETFs

Trey A. Roessig; Roger T. Howe; Albert P. Pisano; James H. Smith

1997-01-01

387

Constructive role of Brownian motion: Brownian motors and Stochastic Resonance  

NASA Astrophysics Data System (ADS)

Noise is usually thought of as the enemy of order rather as a constructive influence. For the phenomena of Stochastic Resonance [1] and Brownian motors [2], however, stochastic noise can play a beneficial role in enhancing detection and/or facilitating directed transmission of information in absence of biasing forces. Brownian motion assisted Stochastic Resonance finds useful applications in physical, technological, biological and biomedical contexts [1,3]. The basic principles that underpin Stochastic Resonance are elucidated and novel applications for nonlinear classical and quantum systems will be addressed. The presence of non-equilibrium disturbances enables to rectify Brownian motion so that quantum and classical objects can be directed around on a priori designed routes in biological and physical systems (Brownian motors). In doing so, the energy from the haphazard motion of (quantum) Brownian particles is extracted to perform useful work against an external load. This very concept together with first experimental realizations are discussed [2,4,5]. [1] L. Gammaitoni, P. Hä'nggi, P. Jung and F. Marchesoni, Stochastic Resonance, Rev. Mod. Phys. 70, 223 (1998).[2] R. D. Astumian and P. Hä'nggi, Brownian motors, Physics Today 55 (11), 33 (2002).[3] P. Hä'nggi, Stochastic Resonace in Physics and Biology, ChemPhysChem 3, 285 (2002).[4] H. Linke, editor, Special Issue on Brownian Motors, Applied Physics A 75, No. 2 (2002).[5] P. Hä'nggi, F. Marchesoni, F. Nori, Brownian motors, Ann. Physik (Leipzig) 14, xxx (2004); cond-mat/0410033.

Hänggi, Peter

2005-03-01

388

An astigmatic unstable resonator with an intracavity deformable mirror  

SciTech Connect

Many side-pumped lasers exhibit significant index gradients across the gain region aperture. For pulsed lasers where these gradients are time dependent, extraction with good beam quality requires the use of an adaptive optic. Since these inhomogeneities are systematic, wavefront correction can be performed with a model deformable mirror. We have designed a resonator which uses a cylindrically deformable mirror to correct for wavefront aberrations in a pulsed nuclear-reactor-driven laser. The mirror is capable of correcting up to ten waves of cylindrical focus error while maintaining tip/tilt alignment of the resonator. It is based around the flat plate bending using magnetostrictive actuators. A cylindrical intracavity beam expander is used to image the DM into the laser gain region. The beam expander can be adjusted to vary the resonator magnification in one axis, or to control the stability of the resonator. The mirror is controlled closed loop using a four channel wavefront sensor and a digital control system. 16 refs., 14 figs.

Neal, D.R. (Sandia National Labs., Albuquerque, NM (United States)); McMillin, P.L. (Kaman Aerospace Corp., Tucson, AZ (United States)); Michie, R.B. (Mission Research Corp., Albuquerque, NM (United States))

1991-01-01

389

Extraction of primary and secondary metabolites.  

PubMed

Several new methods besides the usual organic solvent extraction have been developed over the last few years for the extraction of primary and secondary metabolites. These are: alcohol extraction with various biocompatible solvents, recovery of carboxylic acids and antibiotics with reactive extraction, dissociation extraction, aqueous two-phase extraction, and supercritical and near critical fluid extraction. Extraction and re-extraction processes are integrated into a single step by emulsion liquid membrane and solid supported liquid membrane extractions. These extraction processes are discussed and compared in this review, along with extraction with reversed micelles, and reactive extraction with the formation of a third phase at the organic-aqueous interface. PMID:15791931

Schügerl, K

2005-01-01

390

Micro-machined resonator oscillator  

DOEpatents

A micro-miniature resonator-oscillator is disclosed. Due to the miniaturization of the resonator-oscillator, oscillation frequencies of one MHz and higher are utilized. A thickness-mode quartz resonator housed in a micro-machined silicon package and operated as a telemetered sensor beacon'' that is, a digital, self-powered, remote, parameter measuring-transmitter in the FM-band. The resonator design uses trapped energy principles and temperature dependence methodology through crystal orientation control, with operation in the 20--100 MHz range. High volume batch-processing manufacturing is utilized, with package and resonator assembly at the wafer level. Unique design features include squeeze-film damping for robust vibration and shock performance, capacitive coupling through micro-machined diaphragms allowing resonator excitation at the package exterior, circuit integration and extremely small (0.1 in. square) dimensioning. A family of micro-miniature sensor beacons is also disclosed with widespread applications as bio-medical sensors, vehicle status monitors and high-volume animal identification and health sensors. The sensor family allows measurement of temperatures, chemicals, acceleration and pressure. A microphone and clock realization is also available. 21 figs.

Koehler, D.R.; Sniegowski, J.J.; Bivens, H.M.; Wessendorf, K.O.

1994-08-16

391

Micro-machined resonator oscillator  

DOEpatents

A micro-miniature resonator-oscillator is disclosed. Due to the miniaturization of the resonator-oscillator, oscillation frequencies of one MHz and higher are utilized. A thickness-mode quartz resonator housed in a micro-machined silicon package and operated as a "telemetered sensor beacon" that is, a digital, self-powered, remote, parameter measuring-transmitter in the FM-band. The resonator design uses trapped energy principles and temperature dependence methodology through crystal orientation control, with operation in the 20-100 MHz range. High volume batch-processing manufacturing is utilized, with package and resonator assembly at the wafer level. Unique design features include squeeze-film damping for robust vibration and shock performance, capacitive coupling through micro-machined diaphragms allowing resonator excitation at the package exterior, circuit integration and extremely small (0.1 in. square) dimensioning. A family of micro-miniature sensor beacons is also disclosed with widespread applications as bio-medical sensors, vehicle status monitors and high-volume animal identification and health sensors. The sensor family allows measurement of temperatures, chemicals, acceleration and pressure. A microphone and clock realization is also available.

Koehler, Dale R. (Albuquerque, NM); Sniegowski, Jeffry J. (Albuquerque, NM); Bivens, Hugh M. (Albuquerque, NM); Wessendorf, Kurt O. (Albuquerque, NM)

1994-01-01

392

Lasing from active optomechanical resonators.  

PubMed

Planar microcavities with distributed Bragg reflectors (DBRs) host, besides confined optical modes, also mechanical resonances due to stop bands in the phonon dispersion relation of the DBRs. These resonances have frequencies in the 10- to 100-GHz range, depending on the resonator's optical wavelength, with quality factors exceeding 1,000. The interaction of photons and phonons in such optomechanical systems can be drastically enhanced, opening a new route towards the manipulation of light. Here we implemented active semiconducting layers into the microcavity to obtain a vertical-cavity surface-emitting laser (VCSEL). Thereby, three resonant excitations-photons, phonons and electrons-can interact strongly with each other providing modulation of the VCSEL laser emission: a picosecond strain pulse injected into the VCSEL excites long-living mechanical resonances therein. As a result, modulation of the lasing intensity at frequencies up to 40?GHz is observed. From these findings, prospective applications of active optomechanical resonators integrated into nanophotonic circuits may emerge. PMID:25008784

Czerniuk, T; Brüggemann, C; Tepper, J; Brodbeck, S; Schneider, C; Kamp, M; Höfling, S; Glavin, B A; Yakovlev, D R; Akimov, A V; Bayer, M

2014-01-01

393

Nucleon resonance electrocouplings from the CLAS meson electroproduction data  

NASA Astrophysics Data System (ADS)

Transition helicity amplitudes ??NN* (electrocouplings) were determined for prominent excited proton states with masses below 1.8 GeV in independent analyses of major meson electroproduction channels: ?+n, ?0p and ?+?-p. Consistent results on resonance electrocouplings obtained from analyses of these exclusive reactions with different non-resonant contributions demonstrate reliable extraction of these fundamental quantities for states that have significant decays for either N? or N?? channels. Preliminary results on electrocouplings of N* states with masses above 1.6 GeV have become available from the CLAS data on ?+?-p electroproduction off protons for the first time. Comparison with quark models and coupled-channel approaches strongly suggest that N* structure is determined by contributions from an internal core of three constituent quarks and an external meson-baryon cloud at the distances covered in these measurements with the CLAS detector.

Aznauryan, I. G.; Burkert, V. D.; Mokeev, V. I.

2012-04-01

394

Resonance ionization mass spectrometry for precise measurements of iostope ratios.  

SciTech Connect

Resonance ionization mass spectrometry offers extremely high sensitivity and elemental selectivity in microanalysis, but the isotopic precision attainable by this technique has been limited. Measured isotope ratios are sensitive to small fluctuations in the pointing, pulse timing, and wavelength of the resonance lasers. We show that, by minimizing these fluctuations using feedback controls and by power-broadening the optical transitions, we are able to measure chromium isotope ratios with statistics-limited precision better than 1%. Small additional improvements in reproducibility come from careful shaping of the electric field in the region where atoms are photoionized and from minimizing pulse-to-pulse variations in the time-of-flight mass spectrometer through which the photoions travel. The increased reproducibility of isotopic measurements on standard materials has enabled us to detect anomalous chromium isotopic abundances in presolar SiC grains extracted from primitive meteorites.

Levine, J.; Savina, M. R.; Stephan, T.; Dauphas, N.; Davis, A. M.; Knight, K. B.; Pellin, M. J.; Materials Science Division; Chicago Center for Cosmochemistry; Univ.of Chicago; Univ. of California at Berkeley; LLNL

2009-11-01

395

Resonance ionization mass spectrometry for precise measurements of isotope ratios  

NASA Astrophysics Data System (ADS)

Resonance ionization mass spectrometry offers extremely high sensitivity and elemental selectivity in microanalysis, but the isotopic precision attainable by this technique has been limited. Measured isotope ratios are sensitive to small fluctuations in the pointing, pulse timing, and wavelength of the resonance lasers. We show that, by minimizing these fluctuations using feedback controls and by power-broadening the optical transitions, we are able to measure chromium isotope ratios with statistics-limited precision better than 1%. Small additional improvements in reproducibility come from careful shaping of the electric field in the region where atoms are photoionized and from minimizing pulse-to-pulse variations in the time-of-flight mass spectrometer through which the photoions travel. The increased reproducibility of isotopic measurements on standard materials has enabled us to detect anomalous chromium isotopic abundances in presolar SiC grains extracted from primitive meteorites.

Levine, Jonathan; Savina, Michael R.; Stephan, Thomas; Dauphas, Nicolas; Davis, Andrew M.; Knight, Kim B.; Pellin, Michael J.

2009-12-01

396

Modern Michelson-Morley Experiment using Cryogenic Optical Resonators  

NASA Astrophysics Data System (ADS)

We report on a new test of Lorentz invariance performed by comparing the resonance frequencies of two orthogonal cryogenic optical resonators subject to Earth's rotation over ˜1 yr. For a possible anisotropy of the speed of light c, we obtain ??c/c0=(2.6±1.7)×10-15. Within the Robertson-Mansouri-Sexl (RMS) test theory, this implies an isotropy violation parameter ?-?-1/2=(-2.2±1.5)×10-9, about 3 times lower than the best previous result. Within the general extension of the standard model of particle physics, we extract limits on seven parameters at accuracies down to 10-15, improving the best previous result by about 2 orders of magnitude.

Müller, Holger; Herrmann, Sven; Braxmaier, Claus; Schiller, Stephan; Peters, Achim

2003-07-01

397

Soil saccharide extraction and detection  

Microsoft Academic Search

Extraction of soil saccharides involves the use of reagents effective in breaking hydrogen and covalent bonds between soil\\u000a constituents and the saccharides. Of the many extractants proposed for saccharide determination, water is commonly used for\\u000a extraction of water-soluble mono- and polysaccharides in soil. Analysis of these water extracts by colorimetric assays (anthrone-sulfuric\\u000a acid and phenol-sulfuric acid methods) often show color

D. A. Martens; W. T. Frankenberger

1993-01-01

398

Graded-index whispering gallery mode resonators  

NASA Technical Reports Server (NTRS)

Whispering gallery mode optical resonators which have spatially-graded refractive indices. In one implementation, the refractive index spatially increases with a distance from an exterior surface of such a resonator towards an interior of the resonator to produce substantially equal spectral separations for different whispering gallery modes. An optical coupler may be used with such a resonator to provide proper optical coupling.

Savchenkov, Anatoliy (Inventor); Maleki, Lutfollah (Inventor); Ilchenko, Vladimir (Inventor); Matsko, Andrey B. (Inventor)

2005-01-01

399

Extraordinary Resonant Scattering in Imperfect Acoustic Cloak  

Microsoft Academic Search

We present a systematic study on the extraordinary resonant scattering in imperfect acoustic cloak by means of acoustic scattering theory. Analysis results demonstrate that the resonances are inevitable due to the perturbation to the ideal cloak, and specific resonance modes are excited by specific order waves. The strength of resonance is determined by the magnitude of perturbation and each order

Ying Cheng; Xiao-Jun Liu

2009-01-01

400

Resonant forcing of multidimensional chaotic map dynamics  

Microsoft Academic Search

We study resonances of chaotic map dynamics. We use the calculus of variations to determine the additive forcing function that induces the largest response. We find that resonant forcing functions complement the separation of nearby trajectories, in that the product of the displacement of nearby trajectories and the resonant forcing is a conserved quantity. As a consequence, the resonant function

Glenn Foster; Alfred W. Hübler; Karin Dahmen

2007-01-01

401

Text Mining with Information Extraction  

Microsoft Academic Search

Text mining concerns looking for patterns in unstructured text. The related task of Informa- tion Extraction (IE) is about locating specific items in natural-language documents. This paper presents a framework for text mining, called DISCOTEX (Discovery from Text EXtraction), using a learned information extraction system to transform text into more structured data which is then mined for interesting relationships. The

Raymond J. Mooney; Un Yong Nahm

2002-01-01

402

Learning for Collective Information Extraction  

Microsoft Academic Search

An Information Extraction (IE) system analyses a set of documents with the aim of identifying certain types of entities and relations between them. Most IE systems treat separate potential extractions as independent. However, in many cases, considering influence s between different candidate extractions could improve overall accuracy. For example, phrase repetitions inside a document are usually associated with the same

Razvan C. Bunescu

2004-01-01

403

Microelectromechanical resonator and method for fabrication  

DOEpatents

A method is disclosed for the robust fabrication of a microelectromechanical (MEM) resonator. In this method, a pattern of holes is formed in the resonator mass with the position, size and number of holes in the pattern being optimized to minimize an uncertainty .DELTA.f in the resonant frequency f.sub.0 of the MEM resonator due to manufacturing process variations (e.g. edge bias). A number of different types of MEM resonators are disclosed which can be formed using this method, including capacitively transduced Lame, wineglass and extensional resonators, and piezoelectric length-extensional resonators.

Wittwer, Jonathan W. (Albuquerque, NM); Olsson, Roy H. (Albuquerque, NM)

2010-01-26

404

Microelectromechanical resonator and method for fabrication  

DOEpatents

A method is disclosed for the robust fabrication of a microelectromechanical (MEM) resonator. In this method, a pattern of holes is formed in the resonator mass with the position, size and number of holes in the pattern being optimized to minimize an uncertainty .DELTA.f in the resonant frequency f.sub.0 of the MEM resonator due to manufacturing process variations (e.g. edge bias). A number of different types of MEM resonators are disclosed which can be formed using this method, including capacitively transduced Lame, wineglass and extensional resonators, and piezoelectric length-extensional resonators.

Wittwer, Jonathan W. (Albuquerque, NM); Olsson, Roy H. (Albuquerque, NM)

2009-11-10

405

Efficiency Analysis of Magnetic Resonance Wireless Power Transfer With Intermediate Resonant Coil  

Microsoft Academic Search

This letter presents an efficiency analysis of a mag- netic resonance wireless power transfer (WPT) system with an intermediate resonant coil. A helical coil and a spiral coil with an additional capacitor are considered as resonant coils for the WPT system. The intermediate resonant coil is set up coaxially and perpendicular to both the Tx and Rx resonant coils in

JinWook Kim; Hyeon-Chang Son; Kwan-Ho Kim; Young-Jin Park

2011-01-01

406

Extraordinary Resonant Scattering in Imperfect Acoustic Cloak  

NASA Astrophysics Data System (ADS)

We present a systematic study on the extraordinary resonant scattering in imperfect acoustic cloak by means of acoustic scattering theory. Analysis results demonstrate that the resonances are inevitable due to the perturbation to the ideal cloak, and specific resonance modes are excited by specific order waves. The strength of resonance is determined by the magnitude of perturbation and each order wave's sensitivity to the perturbation. Further studies reveal the unique scattering characters of different resonance modes.

Cheng, Ying; Liu, Xiao-Jun

2009-01-01

407

Pediatric Brain Extraction Using Learning-based Meta-algorithm  

PubMed Central

Magnetic resonance imaging of pediatric brain provides valuable information for early brain development studies. Automated brain extraction is challenging due to the small brain size and dynamic change of tissue contrast in the developing brains. In this paper, we propose a novel Learning Algorithm for Brain Extraction and Labeling (LABEL) specially for the pediatric MR brain images. The idea is to perform multiple complementary brain extractions on a given testing image by using a meta-algorithm, including BET and BSE, where the parameters of each run of the meta-algorithm are effectively learned from the training data. Also, the representative subjects are selected as exemplars and used to guide brain extraction of new subjects in different age groups. We further develop a level-set based fusion method to combine multiple brain extractions together with a closed smooth surface for obtaining the final extraction. The proposed method has been extensively evaluated in subjects of three representative age groups, such as neonate (less than 2 months), infant (1–2 years), and child (5–18 years). Experimental results show that, with 45 subjects for training (15 neonates, 15 infant, and 15 children), the proposed method can produce more accurate brain extraction results on 246 testing subjects (75 neonates, 126 infants, and 45 children), i.e., at average Jaccard Index of 0.953, compared to those by BET (0.918), BSE (0.902), ROBEX (0.901), GCUT (0.856), and other fusion methods such as Majority Voting (0.919) and STAPLE (0.941). Along with the largely-improved computational efficiency, the proposed method demonstrates its ability of automated brain extraction for pediatric MR images in a large age range.

Shi, Feng; Wang, Li; Dai, Yakang; Gilmore, John H.; Lin, Weili; Shen, Dinggang

2012-01-01

408

Noise-enabled precision measurements of a duffing nanomechanical resonator.  

PubMed

We report quantitative measurements of the nonlinear response of a radio frequency mechanical resonator with a very high quality factor. We measure the noise-free transitions between the two basins of attraction that appear in the nonlinear regime, and find good agreement with theory. We measure the transition rate response to controlled levels of white noise, and extract the basin activation energy. This allows us to obtain precise values for the relevant frequencies and the cubic nonlinearity in the Duffing oscillator, with applications to parametric sensing. PMID:15904165

Aldridge, J S; Cleland, A N

2005-04-22

409

Nonadiabatic dynamics of two strongly coupled nanomechanical resonator modes.  

PubMed

The Landau-Zener transition is a fundamental concept for dynamical quantum systems and has been studied in numerous fields of physics. Here, we present a classical mechanical model system exhibiting analogous behavior using two inversely tunable, strongly coupled modes of the same nanomechanical beam resonator. In the adiabatic limit, the anticrossing between the two modes is observed and the coupling strength extracted. Sweeping an initialized mode across the coupling region allows mapping of the progression from diabatic to adiabatic transitions as a function of the sweep rate. PMID:22861892

Faust, Thomas; Rieger, Johannes; Seitner, Maximilian J; Krenn, Peter; Kotthaus, Jörg P; Weig, Eva M

2012-07-20

410

Deposition of diamondlike films by electron cyclotron resonance microwave plasmas  

NASA Technical Reports Server (NTRS)

Hard a-C:H films have been deposited through electron cyclotron resonance (ECR) microwave plasma decomposition of CH4 diluted with H2 gas. It has been found that hard diamondlike films could only be produced under a RF-induced negative self-bias of the substrate stage. Raman spectra indicate the deposition of two distinct film types: one film type exhibiting well-defined bands at 1360 and 1580/cm and another displaying a broad Raman peak centered at approximately 1500/cm. Variation of the mirror magnetic-field profile of the ECR system was examined, demonstrating the manipulation of film morphology through the extraction of different ion energies.

Pool, F. S.; Shing, Y. H.

1990-01-01

411

Extracting tag hierarchies.  

PubMed

Tagging items with descriptive annotations or keywords is a very natural way to compress and highlight information about the properties of the given entity. Over the years several methods have been proposed for extracting a hierarchy between the tags for systems with a "flat", egalitarian organization of the tags, which is very common when the tags correspond to free words given by numerous independent people. Here we present a complete framework for automated tag hierarchy extraction based on tag occurrence statistics. Along with proposing new algorithms, we are also introducing different quality measures enabling the detailed comparison of competing approaches from different aspects. Furthermore, we set up a synthetic, computer generated benchmark providing a versatile tool for testing, with a couple of tunable parameters capable of generating a wide range of test beds. Beside the computer generated input we also use real data in our studies, including a biological example with a pre-defined hierarchy between the tags. The encouraging similarity between the pre-defined and reconstructed hierarchy, as well as the seemingly meaningful hierarchies obtained for other real systems indicate that tag hierarchy extraction is a very promising direction for further research with a great potential for practical applications. Tags have become very prevalent nowadays in various online platforms ranging from blogs through scientific publications to protein databases. Furthermore, tagging systems dedicated for voluntary tagging of photos, films, books, etc. with free words are also becoming popular. The emerging large collections of tags associated with different objects are often referred to as folksonomies, highlighting their collaborative origin and the "flat" organization of the tags opposed to traditional hierarchical categorization. Adding a tag hierarchy corresponding to a given folksonomy can very effectively help narrowing or broadening the scope of search. Moreover, recommendation systems could also benefit from a tag hierarchy. PMID:24391901

Tibély, Gergely; Pollner, Péter; Vicsek, Tamás; Palla, Gergely

2013-01-01

412

Extracting Tag Hierarchies  

PubMed Central

Tagging items with descriptive annotations or keywords is a very natural way to compress and highlight information about the properties of the given entity. Over the years several methods have been proposed for extracting a hierarchy between the tags for systems with a "flat", egalitarian organization of the tags, which is very common when the tags correspond to free words given by numerous independent people. Here we present a complete framework for automated tag hierarchy extraction based on tag occurrence statistics. Along with proposing new algorithms, we are also introducing different quality measures enabling the detailed comparison of competing approaches from different aspects. Furthermore, we set up a synthetic, computer generated benchmark providing a versatile tool for testing, with a couple of tunable parameters capable of generating a wide range of test beds. Beside the computer generated input we also use real data in our studies, including a biological example with a pre-defined hierarchy between the tags. The encouraging similarity between the pre-defined and reconstructed hierarchy, as well as the seemingly meaningful hierarchies obtained for other real systems indicate that tag hierarchy extraction is a very promising direction for further research with a great potential for practical applications. Tags have become very prevalent nowadays in various online platforms ranging from blogs through scientific publications to protein databases. Furthermore, tagging systems dedicated for voluntary tagging of photos, films, books, etc. with free words are also becoming popular. The emerging large collections of tags associated with different objects are often referred to as folksonomies, highlighting their collaborative origin and the “flat” organization of the tags opposed to traditional hierarchical categorization. Adding a tag hierarchy corresponding to a given folksonomy can very effectively help narrowing or broadening the scope of search. Moreover, recommendation systems could also benefit from a tag hierarchy.

Tibely, Gergely; Pollner, Peter; Vicsek, Tamas; Palla, Gergely

2013-01-01

413

Reverse resonance and stochastic resonance in intracellular calcium oscillations  

NASA Astrophysics Data System (ADS)

The roles of time delay on the coherence resonance are investigated in the intracellular calcium oscillation system described by the processes of active and passive transport of intracellular Ca2+ driven by colored noises. From the numerical simulation of the reciprocal coefficient of variance of interspike intervals of calcium spikes by the method of second-order algorithm, the results indicate that: (i) The stochastic or reverse synchronization is induced by a certain value of time delay or correlation time; (ii) A phenomenon of reverse resonance can be obtained in the function of reciprocal coefficient of variance vs. time delay or vs. strength of noises as time delay increases; (iii) Both stochastic and reverse resonance are observed in the function of reciprocal coefficient of variance vs. correlation time with varying strength of noises.

Duan, Wei-Long; Long, Fei; Li, Chun

2014-05-01

414

Method of extracting tetrodotoxin  

US Patent & Trademark Office Database

The present invention relates to a new process of extracting tetrodotoxin from the tissues of an organism. The invention provides increased yield of tetrodotoxin from animal tissues. In the invention, a lixiviated solution is obtained by soaking the tissues with water and a weak organic acid. Soluble proteins are removed by heating the lixiviated solution at a temperature below the boiling point. After pH adjustment, the solution is passed through a cation exchange column. Inorganic salts and alkaline amino acids are removed, and then the tetrodotoxin is adsorbed and eluted from activated carbon. The tetrodotoxin is crystallized by adjusting the pH to 8-10.

2003-04-22

415

Coal extraction - environmental prediction  

SciTech Connect

To predict and help minimize the impact of coal extraction in the Appalachian region, the U.S. Geological Survey (USGS) is addressing selected mine-drainage issues through the following four interrelated studies: spatial variability of deleterious materials in coal and coal-bearing strata; kinetics of pyrite oxidation; improved spatial geologic models of the potential for drainage from abandoned coal mines; and methodologies for the remediation of waters discharged from coal mines. As these goals are achieved, the recovery of coal resources will be enhanced. 2 figs.

C. Blaine Cecil; Susan J. Tewalt

2002-08-01

416

Stability of the BSCC heart valve outlet strut resonant frequency under changing physiological conditions and observation times  

Microsoft Academic Search

Acoustic monitoring techniques have been developed to determine the state of BSCC (Bjork-Shiley Convexo-Concave) artificial heart valves. The signal processing is based primarily on time-windowed Fourier analysis that extracts the resonant frequency of the intact outlet strut (IOS). The absence of the resonant waveform is an indicator that the outlet strut has one of its legs separated from the valve's

Terry D. Plemons; S. G. Schreck; R. S. Inderbitzen

1994-01-01

417

Wideband measurement of the dielectric constant of an FR4 substrate using a parallel-coupled microstrip resonator  

Microsoft Academic Search

We have made a wideband measurement of the real part of the dielectric constant of flame retardant #4 epoxy (FR4), a common high-frequency printed-circuit-board insulator. We designed a novel test circuit, an electrically long parallel-coupled microstrip resonator, which was etched on a 0.014-in FR4 substrate, manufactured by NELCO, Melville, NY. We used a computer model of the resonator to extract

Eric L. Holzman

2006-01-01

418

Robust Brain Extraction Across Datasets and Comparison With Publicly Available Methods  

Microsoft Academic Search

Automatic whole-brain extraction from magnetic resonance images (MRI), also known as skull stripping, is a key component in most neuroimage pipelines. As the first element in the chain, its robustness is critical for the overall performance of the system. Many skull stripping methods have been proposed, but the problem is not considered to be completely solved yet. Many systems in

Juan Eugenio Iglesias; Cheng-Yi Liu; Paul M. Thompson; Zhuowen Tu

2011-01-01

419

Automated 3-D Extraction of Inner and Outer Surfaces of Cerebral Cortex from MRI  

Microsoft Academic Search

Automatic computer processing of large multidimensional images such as those produced by magnetic resonance imaging (MRI) is greatly aided by deformable models, which are used to extract, identify, and quantify specific neuroanatomic structures. A general method of deforming polyhedra is presented here, with two novel features. First, explicit prevention of self-intersecting surface geometries is provided, unlike conventional deformable models, which

David MacDonald; Noor Kabani; David Avis; Alan C. Evans

2000-01-01

420

Specific boundary conditions for the simulation of extraction for ECRIS, LIS, and H--sources  

Microsoft Academic Search

The necessity of a three-dimensional simulation of the extraction has been accepted for electron cyclotron resonance ion sources (ECRIS) as well as for negative ion sources. For an ECRIS, the magnetic hexapole together with the solenoidal mirror field defines a minimum B structure which confines the plasma. Depending on the magnetic flux density distribution, the plasma density in front of

P. Spadtke; K. Tinschert

2005-01-01

421

Pattern formation in optical resonators  

NASA Astrophysics Data System (ADS)

We review pattern formation in optical resonators. The emphasis is on 'particle-like' structures such as vortices or spatial solitons. On the one hand, similarities impose themselves with other fields of physics (condensed matter, phase transitions, particle physics, fluds/super fluids). On the other hand the feedback is led by the resonator mirrors to bi- and multi-stability of the spatial field structure, which is the basic ingredient for optical information processing. The spatial dimension or the 'parallelism' is the strength of optics compared to electronics (and will have to be employed to fully use the advantages optics offers in information processing). But even in the 'serial' processing tasks of telecoms (e.g. information buffering) spatial resonator solitons can do better than the schemes proposed so far—including 'slow light'. Pattern formation in optical resonators will likely be the key to brain-like information processing like cognition, learning and association; to complement the precise but limited algorithmic capabilities of electronic processing. But even in the short term it will be useful for solving serial optical processing problems. The prospects for technical uses of pattern formation in resonators are one motivation for this research. The fundamental similarities with other fields of physics, on the other hand, inspire transfer of concepts between fields; something that has always proven fruitful for gaining deeper insights or for solving technical problems.

Weiss, C. O.; Larionova, Ye

2007-02-01

422

Anti-resonance mixing filter  

NASA Technical Reports Server (NTRS)

In a closed loop control system that governs the movement of an actuator a filter is provided that attenuates the oscillations generated by the actuator when the actuator is at a resonant frequency. The filter is preferably coded into the control system and includes the following steps. Sensing the position of the actuator with an LVDT and sensing the motor position where motor drives the actuator through a gear train. When the actuator is at a resonant frequency, a lag is applied to the LVDT signal and then combined with the motor position signal to form a combined signal in which the oscillation generated by the actuator are attenuated. The control system then controls ion this combined signal. This arrangement prevents the amplified resonance present on the LVDT signal, from causing control instability, while retaining the steady state accuracy associated with the LVDT signal. It is also a characteristic of this arrangement that the signal attenuation will always coincide with the load resonance frequency of the system so that variations in the resonance frequency will not effectuate the effectiveness of the filter.

Evans, Paul S. (Inventor)

2001-01-01

423

Matryoshka locally resonant sonic crystal  

NASA Astrophysics Data System (ADS)

The results of numerical modelling of sonic crystals with resonant array elements are reported. The investigated resonant elements include plain slotted cylinders as well as various their combinations, in particular, Russian doll or Matryoshka configurations. The acoustic band structure and transmission characteristics of such systems have been computed with the use of finite element methods. The general concept of a locally resonant sonic crystal is proposed, which utilises acoustic resonances to form additional band gaps that are decoupled from Bragg gaps. An existence of a separate attenuation mechanism associated with the resonant elements, which increases performance in the lower frequency regime has been identified. The results show a formation of broad band gaps positioned significantly below the first Bragg frequency. For low frequency broadband attenuation a most optimal configuration is the Matryoshka sonic crystal, where each scattering unit is composed of multiple concentric slotted cylinders. This system forms numerous gaps in the lower frequency regime, below Bragg bands, whilst maintaining a reduced crystal size viable for noise barrier technology. The finding opens new perspectives for construction of sound barriers in the low frequency range usually inaccessible by traditional means including conventional sonic crystals.

Elford, Daniel P.; Chalmers, Luke; Kusmartsev, Feodor V.; Swallowe, Gerry M.

424

Schumann's resonances: A particular example of a spherical resonant cavity  

NASA Astrophysics Data System (ADS)

The resonances between the Earth as one boundary and the ionosphere as the other, known as Schumann's resonances, represent an interesting example of a spherical cavity. We consider a simple model in which the boundaries behave as perfect conductors and then take into account the finite conductivity of the boundaries. Numerical results are obtained for both models and compared with available data. Good agreement is shown to exist between the analytical results and the experimental values when finite conductivity of the walls is considered.

Ciappina, M. F.; Febbo, M.

2004-05-01

425

COMMISSIONING RESULTS OF SLOW EXTRACTION OF HEAVY IONS FROM THE AGS BOOSTER.  

SciTech Connect

Brookhaven's AGS Booster has been modified to deliver slow extracted beam to a new beam line, the NASA Space Radiation Laboratory (NSRL). This facility was constructed in collaboration with NASA for the purpose of performing radiation effect studies for the NASA space program. The design of the resonant extraction system has been described in [1]. A more detailed description, which includes predictions of the slow extracted beam time structure has been described in [2]. In this report we will present results of the system commissioning and performance.

Brown, K A; Bellavia, S; Binello, S; Brelsford, B; Dumont, D; Eng, W; Gardner, G; Gassner, D; Glenn, J W; Hammons, L; Hock, J; Hoff, L; Hutchinson, E; Jamilkowski, J; Kling, N; Kotlyar, Y; Krishock, A; Lockey, R; Mapes, M; Marneris, I; Marr, G; McNerney, A; Meyer, A; Morris, J; Naylor, C; Nemesure, S; Phillips, D; Rusek, A; Ryan, J; Shrey, T; Snydstrup, L; Tsoupas, N; Vankuik, B; Zahariou-Cohen, K

2003-05-12

426

Fast-extraction modulators for Los Alamos Scientific LaboratorY Proton Storage Ring  

SciTech Connect

The development of a short-bunch mode fast-extraction modulator for the LASL proton storage ring has made necessary the design and development of a resonant transformer charging circuit and the design of a new FIB line circuit to provide bipolar pulse outputs with low prepulse, postpulse, and an optimum high-voltage switch environments. The systems are now being developed to operate reliably at the high-average powers required. The short-bunch mode fast-extraction modulator prototype is presently operating. The initial construction of the long-bunch mode fast-extraction modulator prototype is under way, with results expected within the year.

Nunnally, W.C.; Hudgings, D.W.; Sarjeant, W.J.

1980-01-01

427

Aqueous extracts of cigarette tar containing the tar free radical cause DNA nicks in mammalian cells.  

PubMed Central

The ability of aqueous extracts of cigarette tar to nick DNA was investigated using viable mammalian cells. Tar extracts contain a radical with a stable electron spin resonance (ESR) signal at g = 2.0036 characteristic of a semiquinone. The association of the tar component that carries the ESR signal with DNA was demonstrated using viable rat alveolar macrophages. The formation of single-strand DNA breaks caused by cigarette tar extracts in viable rat thymocytes follows saturation kinetics, indicating a tar component associates with DNA and then nicks it. These studies support our hypothesis that tar components that contain the cigarette tar radical can enter cells, associate with, and then nick DNA.

Stone, K K; Bermudez, E; Pryor, W A

1994-01-01

428

Antimicrobial efficacy of henna extracts.  

PubMed

Lawsonia inermis (henna plant) has been used in herbal medicine for ages. However, the medical benefits of this plant have been discussed in only a few publications. In this study, the antibacterial effects of water, alcoholic and oily extracts of Lawsonia inermis leaves against bacterial cultures isolated from various skin diseases were investigated and compared with Tetracycline, Ampicillin, Gentamicin and Ciprofloxacin antibiotics. Cultures of Staphylococcus aureus Staphylococcus epidermidis (Co-agulase negative staphylococci or CONS), ß-hemolytic streptococci and Pseudomonas aeruginosa species were obtained from 74 (35 females, 39 males) patients with different skin infections who attended the Dermatology outpatient clinic in Basra General Hospital. The bacterial isolates were treated with L. inermis extracts in vitro. Alcoholic and oily extracts were more effective than the water extract which had no effects using standard method of NCCL, 2000.Alcoholic extracts had the highest antibacterial activity with a MIC of 0.125-0.150 µg/ml against ß-hemolytic streptococci and against CONS was 0.125-175 µg/ml .Oily extracts had a MIC of 0.25-0.30 µg/ml against Staphylococcus epidermidis (cons). Both alcoholic and oily extracts had the same MIC (0.5 µg/ml) on Staphylococcus aureus. However, alcoholic extracts were more effective on Pseudomonas aeruginosa with a MIC of 0.5-0.57 µg/ml than oily extract (MIC of 0.20-0.28 µg/ml). However, there were no statically differences between the effects of oily and alcoholic henna extracts (p= 0.050).When comparing the extracts' MICs with those of antibiotics, alcoholic extracts showed pronounced antibacterial effects against the isolated bacteria in vitro but oily extracts had much similar MICs to those of antibiotics and there are significant difference between effect of both extracts and antibiotics p>0.050. PMID:22334837

Al-Rubiay, Kathem K; Jaber, Nawres N; Alrubaiy, Laith K

2008-10-01

429

Resonance Effects in the NASA Transonic Flutter Cascade Facility  

NASA Technical Reports Server (NTRS)

Investigations of unsteady pressure loadings on the blades of fans operating near the stall flutter boundary are carried out under simulated conditions in the NASA Transonic Flutter Cascade facility (TFC). It has been observed that for inlet Mach numbers of about 0.8, the cascade flowfield exhibits intense low-frequency pressure oscillations. The origins of these oscillations were not clear. It was speculated that this behavior was either caused by instabilities in the blade separated flow zone or that it was a tunnel resonance phenomenon. It has now been determined that the strong low-frequency oscillations, observed in the TFC facility, are not a cascade phenomenon contributing to blade flutter, but that they are solely caused by the tunnel resonance characteristics. Most likely, the self-induced oscillations originate in the system of exit duct resonators. For sure, the self-induced oscillations can be significantly suppressed for a narrow range of inlet Mach numbers by tuning one of the resonators. A considerable amount of flutter simulation data has been acquired in this facility to date, and therefore it is of interest to know how much this tunnel self-induced flow oscillation influences the experimental data at high subsonic Mach numbers since this facility is being used to simulate flutter in transonic fans. In short, can this body of experimental data still be used reliably to verify computer codes for blade flutter and blade life predictions? To answer this question a study on resonance effects in the NASA TFC facility was carried out. The results, based on spectral and ensemble averaging analysis of the cascade data, showed that the interaction between self-induced oscillations and forced blade motion oscillations is very weak and can generally be neglected. The forced motion data acquired with the mistuned tunnel, when strong self-induced oscillations were present, can be used as reliable forced pressure fluctuations provided that they are extracted from raw data sets by an ensemble averaging procedure.

Lepicovsky, J.; Capece, V. R.; Ford, C. T.

2003-01-01

430

A potential commercial source of fucoxanthin extracted from the microalga Phaeodactylum tricornutum.  

PubMed

Fucoxanthin, one of the main marine carotenoids, is abundant in macro- and microalgae. Here, fucoxanthin was isolated and structurally identified as the major carotenoid in the diatom Phaeodactylum tricornutum through chromatographic and spectroscopic methods, such as liquid chromatography-positive-ion atmospheric pressure chemical ionization/mass spectroscopy and nuclear magnetic resonance. This pigment was quantified by reverse-phase high-performance liquid chromatography, and a number of extraction procedures were assessed to investigate the effect of solvent type, extraction time, temperature, and extraction method (maceration, ultrasound-assisted extraction, Soxhlet extraction, and pressurized liquid extraction). Among the investigated solvents, ethanol provided the best fucoxanthin extraction yield (15.71 mg/g freeze-dried sample weight). Fucoxanthin content in the extracts produced by the different methods was quite constant (15.42-16.51 mg/g freeze-dried sample weight) but increased steeply based on the percentage of ethanol in water, emphasizing the importance of ethanol in the extraction. The results indicate that P. tricornutum is a rich source of fucoxanthin (at least ten times more abundant than that in macroalgae) that is easily extracted with ethanol, suggesting potential applications in human and animal food, health, and cosmetics. PMID:22371063

Kim, Sang Min; Jung, Yu-Jin; Kwon, Oh-Nam; Cha, Kwang Hyun; Um, Byung-Hun; Chung, Donghwa; Pan, Cheol-Ho

2012-04-01

431

Viscoelastic coupling of nanoelectromechanical resonators.  

SciTech Connect

This report summarizes work to date on a new collaboration between Sandia National Laboratories and the California Institute of Technology (Caltech) to utilize nanoelectromechanical resonators designed at Caltech as platforms to measure the mechanical properties of polymeric materials at length scales on the order of 10-50 nm. Caltech has succeeded in reproducibly building cantilever resonators having major dimensions on the order of 2-5 microns. These devices are fabricated in pairs, with free ends separated by reproducible gaps having dimensions on the order of 10-50 nm. By controlled placement of materials that bridge the very small gap between resonators, the mechanical devices become coupled through the test material, and the transmission of energy between the devices can be monitored. This should allow for measurements of viscoelastic properties of polymeric materials at high frequency over short distances. Our work to date has been directed toward establishing this measurement capability at Sandia.

Simonson, Robert Joseph; Staton, Alan W.

2009-09-01

432

?-meson photoproduction and N* resonances  

NASA Astrophysics Data System (ADS)

We investigate the ? photoproduction using the effective Lagrangian approach at the tree level. We include eight nucleon resonances, that is, D13(1520), S11(1535), S11(1650), D15(1675), F15(1680), D13(1700), P11(1710), P13(1720) as well as possible background contributions. In addition, we introduce the new nucleon resonance N*(1675) which was announced by the GRAAL, CB-ELSA and Tohoku LNS-GeV-? experiments. We investigate a possible role of the resonance with testing its spin and parity for four different cases of JP = 1/2± and 3/2±. We calculate various cross sections including beam asymmetries for neutron and proton targets. We find noticeable isospin asymmetry in transition amplitudes for proton and neutron targets.

Choi, K. S.; Nam, S. I.; Hosaka, A.; Kim, H. Ch

2009-01-01

433

High-temperature superconducting resonators.  

PubMed

Preliminary measurements on high-T(c) superconducting resonators are reported and why they are attractive candidates for incorporation in low-noise oscillators is discussed. Some of the important contributions to oscillator noise are reviewed and how they depend on the resonator parameters is shown. A preliminary YBaCu (3)O(7)/LaAlO(3) resonator with a Q of 9x10(4) at 6.9 GHz and 7x10(4) at 3.5 GHz has been fabricated. The temperature sensitivity, power dependence, and residual phase noise are discussed. An upper-limit on the coefficient of the 1/f component of fractional-frequency fluctuations has been measured to be -204 dB at 60 K. PMID:18267649

Taber, R C; Hollenhorst, J N; Cutler, L S; Bagwell, T L; Newman, N; Cole, B F

1992-01-01

434

Clamping instability and van der waals forces in carbon nanotube mechanical resonators.  

PubMed

We investigate the role of weak clamping forces, typically assumed to be infinite, in carbon nanotube mechanical resonators. Due to these forces, we observe a hysteretic clamping and unclamping of the nanotube device that results in a discrete drop in the mechanical resonance frequency on the order of 5-20 MHz, when the temperature is cycled between 340 and 375 K. This instability in the resonant frequency results from the nanotube unpinning from the electrode/trench sidewall where it is bound weakly by van der Waals forces. Interestingly, this unpinning does not affect the Q-factor of the resonance, since the clamping is still governed by van der Waals forces above and below the unpinning. For a 1 ?m device, the drop observed in resonance frequency corresponds to a change in nanotube length of approximately 50-65 nm. On the basis of these findings, we introduce a new model, which includes a finite tension around zero gate voltage due to van der Waals forces and shows better agreement with the experimental data than the perfect clamping model. From the gate dependence of the mechanical resonance frequency, we extract the van der Waals clamping force to be 1.8 pN. The mechanical resonance frequency exhibits a striking temperature dependence below 200 K attributed to a temperature-dependent slack arising from the competition between the van der Waals force and the thermal fluctuations in the suspended nanotube. PMID:24758201

Aykol, Mehmet; Hou, Bingya; Dhall, Rohan; Chang, Shun-Wen; Branham, William; Qiu, Jing; Cronin, Stephen B

2014-05-14

435

Fractional tunnelling resonance in plasmonic media  

NASA Astrophysics Data System (ADS)

Metals can transmit light by tunnelling when they possess skin-depth thickness. Tunnelling can be resonantly enhanced if resonators are added to each side of a metal film, such as additional dielectric layers or periodic structures on a metal surface. Here we show that, even with no additional resonators, tunnelling resonance can arise if the metal film is confined and fractionally thin. In a slit waveguide filled with a negative permittivity metallic slab of thickness L, resonance is shown to arise at fractional thicknesses (L = Const./m; m = 1,2,3,…) by the excitation of `vortex plasmons'. We experimentally demonstrate fractional tunnelling resonance and vortex plasmons using microwave and negative permittivity metamaterials. The measured spectral peaks of the fractional tunnelling resonance and modes of the vortex plasmons agree with theoretical predictions. Fractional tunnelling resonance and vortex plasmons open new perspectives in resonance physics and promise potential applications in nanotechnology.

Kang, Ji-Hun; -Han Park, Q.

2013-08-01

436

Fractional tunnelling resonance in plasmonic media  

PubMed Central

Metals can transmit light by tunnelling when they possess skin-depth thickness. Tunnelling can be resonantly enhanced if resonators are added to each side of a metal film, such as additional dielectric layers or periodic structures on a metal surface. Here we show that, even with no additional resonators, tunnelling resonance can arise if the metal film is confined and fractionally thin. In a slit waveguide filled with a negative permittivity metallic slab of thickness L, resonance is shown to arise at fractional thicknesses (L = Const./m; m = 1,2,3,…) by the excitation of ‘vortex plasmons'. We experimentally demonstrate fractional tunnelling resonance and vortex plasmons using microwave and negative permittivity metamaterials. The measured spectral peaks of the fractional tunnelling resonance and modes of the vortex plasmons agree with theoretical predictions. Fractional tunnelling resonance and vortex plasmons open new perspectives in resonance physics and promise potential applications in nanotechnology.

Kang, Ji-Hun; -Han Park, Q.

2013-01-01

437

Giant resonances: Progress, new directions, new challenges  

SciTech Connect

A review of some recent developments in the field of giant multipole resonances is presented. Particular emphasis is placed on directions that the authors feel will be followed in this field during the next several years. In particular, the use of high-energy heavy ions to excite the giant resonances is shown to provide exciting new capabilities for giant resonance studies. Among subjects covered are: Coulomb excitation of giant resonances, photon decay of giant resonances, the recent controversy over the identity of the giant monopole resonance, the most recent value for incompressibility of nuclear matter from analysis of giant monopole data, the isospin character of the 63 A/sup /minus/1/3/ GQR, agreement between (e,e/prime/) and (hadron, hadron/prime/) excitation of the giant quadrupole resonance, prospects for multiphonon giant resonance observation, and isolation of the isovector giant quadrupole resonance. 55 refs., 23 figs., 4 tabs.

Bertrand, J.R.; Beene, J.R.

1989-01-01

438

Fractional tunnelling resonance in plasmonic media.  

PubMed

Metals can transmit light by tunnelling when they possess skin-depth thickness. Tunnelling can be resonantly enhanced if resonators are added to each side of a metal film, such as additional dielectric layers or periodic structures on a metal surface. Here we show that, even with no additional resonators, tunnelling resonance can arise if the metal film is confined and fractionally thin. In a slit waveguide filled with a negative permittivity metallic slab of thickness L, resonance is shown to arise at fractional thicknesses (L = Const./m; m = 1,2,3,…) by the excitation of 'vortex plasmons'. We experimentally demonstrate fractional tunnelling resonance and vortex plasmons using microwave and negative permittivity metamaterials. The measured spectral peaks of the fractional tunnelling resonance and modes of the vortex plasmons agree with theoretical predictions. Fractional tunnelling resonance and vortex plasmons open new perspectives in resonance physics and promise potential applications in nanotechnology. PMID:23939460

Kang, Ji-Hun; Park, Q-Han

2013-01-01

439

21 CFR 73.1410 - Logwood extract.  

Code of Federal Regulations, 2010 CFR

...CERTIFICATION Drugs § 73.1410 Logwood extract. (a) Identity. The color additive logwood extract is a reddish brown-to-black solid material extracted from... (b) Specifications. Logwood extract shall conform to...

2010-04-01

440

21 CFR 73.1410 - Logwood extract.  

Code of Federal Regulations, 2010 CFR

...CERTIFICATION Drugs § 73.1410 Logwood extract. (a) Identity. The color additive logwood extract is a reddish brown-to- black solid material extracted from... (b) Specifications. Logwood extract shall conform to...

2009-04-01

441

Gallium nitride nanowire electromechanical resonators  

NASA Astrophysics Data System (ADS)

Nanoscale mechanical resonators are of great interest for high-resolution sensing applications, where the small resonator mass and high quality factor (Q, defined as resonance frequency f0 over full width at half maximum power) lead to unprecedented sensitivity. Here, we investigate gallium nitride (GaN) nanowire (NW) resonators. The single-crystal, c-axis NWs are 5 mum -- 20 mum long, with diameters from 50 nm -- 500 nm, and grow essentially free of defects. Our initial experiments involve measuring the resonances of as-grown NWs in a scanning electron microscope, where we observe exceptionally high Q values of 10 4 -- 105, one to two orders of magnitude higher than most NWs of comparable size. Using a single NW as a mass sensor, we then demonstrate a sub-attogram mass sensitivity. To provide a more flexible measurement technique that avoids electron-microscope detection, we fabricate doubly clamped NWs with an entirely electronic drive and readout scheme using a combination of lithographic patterning and dielectrophoresis. An electrostatic gate induces vibration, while readout utilizes the piezoresistivity of GaN. Observed resonances range from 9--36 MHz with Q values typically around 103 at room temperature and 10 -4 Pa. We use the behavior of f0 and Q to sense the NW's local environment, such as the additional sources of energy dissipation not present in the as-grown NWs. By cooling the device to 8 K, Q increases by an order of magnitude to above 104, with a highest value to date of 26,000 under vacuum. We explore additional NW properties through the thermal noise in the NW's mechanical motion and the exponential decay of mechanical motion in the presence of burst drive. Finally, we investigate the low-frequency 1/f parameter noise displayed by f0. We show that the noise in f0 is consistent with noise in the NW's resistance leading to temperature noise from local Joule heating, which in turn generates resonance frequency noise. For sensor applications, there will be optimal drive conditions that balance the f 0 noise with the signal-to-noise ratio of the system. With these insights, along with the simple drive and readout technique, these GaN-NW doubly clamped resonators have significant potential for high-resolution sensing applications.

Gray, Jason Michael

442

Atomic negative-ion resonances  

SciTech Connect

The authors attempt to give a comprehensive discussion of observations of atomic negative-ion resonances throughout the periodic table. A review of experimental and theoretical approaches to the study of negative-ion resonances is given together with a consideration of the various schemes that are used for their classification. In addition to providing, where possible, tabulated data for the energies, widths, and symmetries of these states, the authors also attempt to highlight regularities in their behavior both within groups of the periodic table and along isoionic sequences.

Buckman, S.J. (Electron Physics Group, Research School of Physical Sciences Engineering, Institute of Advanced Studies, The Australian National University, Canberra ACT 2601 (Australia)); Clark, C.W. (U. S. Department of Commerce, Technology Administration, National Institute of Standards and Technology, Electron and Optical Physics Division, Gaithersburg, Maryland 20899 (United States))

1994-04-01

443

Single resonance theory with maps  

SciTech Connect

We describe how one can perform a single resonance calculation using the single resonance map and the co-moving map. Again we emphasize that all the concepts of this paper have been implemented for the most complicated situations using the Differential Algebra Package of Berz. In theory, it is possible and desirable to do similar calculations on fitted maps (a la Warnock) with fitted canonical transformations, unfortunately the tools based on fitted maps are not yet as versatile as DA-based tools. 5 refs.

Forest, E. (Lawrence Berkeley Lab., CA (USA)); Irwin, J. (Stanford Linear Accelerator Center, Menlo Park, CA (USA))

1990-04-01

444

Whispering gallery mode diamond resonator.  

PubMed

We demonstrate a nearly spherical diamond whispering gallery mode resonator with quality factor (Q factor) Q=2.4×10(7) limited by material loss approaching ?=4×10(-3) cm(-1). The Q factor does not depend on the wavelength: it is approximately the same at 1319 and 1550 nm. Resonators with this range of Q (<10 MHz at 1550 nm wavelength) are attractive for laser locking and stabilization. Applications such as stable compact optical comb generators as well as Raman optical frequency shifters will be feasible with further improvement of the material. PMID:24177083

Ilchenko, V S; Bennett, A M; Santini, P; Savchenkov, A A; Matsko, A B; Maleki, L

2013-11-01

445

Stepped impedance resonators for high-field magnetic resonance imaging.  

PubMed

Multi-element volume radio-frequency (RF) coils are an integral aspect of the growing field of high-field magnetic resonance imaging. In these systems, a popular volume coil of choice has become the transverse electromagnetic (TEM) transceiver coil consisting of microstrip resonators. In this paper, to further advance this design approach, a new microstrip resonator strategy in which the transmission line is segmented into alternating impedance sections, referred to as stepped impedance resonators (SIRs), is investigated. Single-element simulation results in free space and in a phantom at 7 T (298 MHz) demonstrate the rationale and feasibility of the SIR design strategy. Simulation and image results at 7 T in a phantom and human head illustrate the improvements in a transmit magnetic field, as well as RF efficiency (transmit magnetic field versus specific absorption rate) when two different SIR designs are incorporated in 8-element volume coil configurations and compared to a volume coil consisting of microstrip elements. PMID:23508243

Akgun, Can E; DelaBarre, Lance; Yoo, Hyoungsuk; Sohn, Sung-Min; Snyder, Carl J; Adriany, Gregor; Ugurbil, Kamil; Gopinath, Anand; Vaughan, J Thomas

2014-02-01

446

Stochastic resonance in electrical circuits. I. Conventional stochastic resonance  

Microsoft Academic Search

Stochastic resonance (SR), a phenomenon in which a periodic signal in a nonlinear system can be amplified by added noise, is introduced and discussed. Techniques for investigating SR using electronic circuits are described in practical terms. The physical nature of SR, and the explanation of weak-noise SR as a linear response phenomenon, are considered. Conventional SR, for systems characterized by

Dmitrii G. Luchinsky; Riccardo Mannella; Peter V. E. McClintock; Nigel G. Stocks

1999-01-01

447

Microwave Frequency Discriminator With Sapphire Resonator  

NASA Technical Reports Server (NTRS)

Cooled sapphire resonator provides ultralow phase noise. Apparatus comprises microwave oscillator operating at nominal frequency of about 8.1 GHz, plus frequency-discriminator circuit measuring phase fluctuations of oscillator output. One outstanding feature of frequency discriminator is sapphire resonator serving as phase reference. Sapphire resonator is dielectric ring resonator operating in "whispering-gallery" mode. Functions at room temperature, but for better performance, typically cooled to operating temperature of about 80 K. Similar resonator described in "Sapphire Ring Resonator for Microwave Oscillator" (NPO-18082).

Santiago, David G.; Dick, G. John

1994-01-01

448

SNAKE DEPLORIZING RESONANCE STUDY IN RHIC  

SciTech Connect

Snake depolarizing resonances due to the imperfect cancellation of the accumulated perturbations on the spin precession between snakes were observed at the Relativistic Heavy Ion Collider (RHIC). During the RHIC 2005 and 2006 polarized proton runs, we mapped out the spectrum of odd order snake resonance at Q{sub y} = 7/10. Here, Q, is the beam vertical betatron tune. We also studied the beam polarization after crossing the 7/10th resonance as a function of resonance crossing rate. This paper reports the measured resonance spectrum as well as the results of resonance crossing.

BAI,M.; CAMERON, P.; LUCCIO, A.; HUANG, H.; PITISYN, V.; ET AL.

2007-06-25

449

Wavelength-tunable optical ring resonators  

DOEpatents

Optical ring resonator devices are disclosed that can be used for optical filtering, modulation or switching, or for use as photodetectors or sensors. These devices can be formed as microdisk ring resonators, or as open-ring resonators with an optical waveguide having a width that varies adiabatically. Electrical and mechanical connections to the open-ring resonators are made near a maximum width of the optical waveguide to minimize losses and thereby provide a high resonator Q. The ring resonators can be tuned using an integral electrical heater, or an integral semiconductor junction.

Watts, Michael R. (Albuquerque, NM); Trotter, Douglas C. (Albuquerque, NM); Young, Ralph W. (Albuquerque, NM); Nielson, Gregory N. (Albuquerque, NM)

2011-07-19

450

Wavelength-tunable optical ring resonators  

DOEpatents

Optical ring resonator devices are disclosed that can be used for optical filtering, modulation or switching, or for use as photodetectors or sensors. These devices can be formed as microdisk ring resonators, or as open-ring resonators with an optical waveguide having a width that varies adiabatically. Electrical and mechanical connections to the open-ring resonators are made near a maximum width of the optical waveguide to minimize losses and thereby provide a high resonator Q. The ring resonators can be tuned using an integral electrical heater, or an integral semiconductor junction.

Watts, Michael R. (Albuquerque, NM); Trotter, Douglas C. (Albuquerque, NM); Young, Ralph W. (Albuquerque, NM); Nielson, Gregory N. (Albuquerque, NM)

2009-11-10

451

Miniature Sapphire Acoustic Resonator - MSAR  

NASA Technical Reports Server (NTRS)

A room temperature sapphire acoustics resonator incorporated into an oscillator represents a possible opportunity to improve on quartz ultrastable oscillator (USO) performance, which has been a staple for NASA missions since the inception of spaceflight. Where quartz technology is very mature and shows a performance improvement of perhaps 1 dB/decade, these sapphire acoustic resonators when integrated with matured quartz electronics could achieve a frequency stability improvement of 10 dB or more. As quartz oscillators are an essential element of nearly all types of frequency standards and reference systems, the success of MSAR would advance the development of frequency standards and systems for both groundbased and flight-based projects. Current quartz oscillator technology is limited by quartz mechanical Q. With a possible improvement of more than x 10 Q with sapphire acoustic modes, the stability limit of current quartz oscillators may be improved tenfold, to 10(exp -14) at 1 second. The electromagnetic modes of sapphire that were previously developed at JPL require cryogenic temperatures to achieve the high Q levels needed to achieve this stability level. However sapphire fs acoustic modes, which have not been used before in a high-stability oscillator, indicate the required Q values (as high as Q = 10(exp 8)) may be achieved at room temperature in the kHz range. Even though sapphire is not piezoelectric, such a high Q should allow electrostatic excitation of the acoustic modes with a combination of DC and AC voltages across a small sapphire disk (approximately equal to l mm thick). The first evaluations under this task will test predictions of an estimated input impedance of 10 kilohms at Q = 10(exp 8), and explore the Q values that can be realized in a smaller resonator, which has not been previously tested for acoustic modes. This initial Q measurement and excitation demonstration can be viewed similar to a transducer converting electrical energy to mechanical energy and back. Such an electrostatic tweeter type excitation of a mechanical resonator will be tested at 5 MHz. Finite element calculation will be applied to resonator design for the desired resonator frequency and optimum configuration. The experiment consists of the sapphire resonator sandwiched between parallel electrodes. A DC+AC voltage can be applied to generate a force to act on a sapphire resonator. With the frequency of the AC voltage tuned to the sapphire resonator frequency, a resonant condition occurs and the sapphire Q can be measured with a high-frequency impedance analyzer. To achieve high Q values, many experimental factors such as vacuum seal, gas damping effects, charge buildup on the sapphire surface, heat dissipation, sapphire anchoring, and the sapphire mounting configuration will need attention. The effects of these parameters will be calculated and folded into the resonator design. It is envisioned that the initial test configuration would allow for movable electrodes to check gap spacing dependency and verify the input impedance prediction. Quartz oscillators are key components in nearly all ground- and space-based communication, tracking, and radio science applications. They play a key role as local oscillators for atomic frequency standards and serve as flywheel oscillators or to improve phase noise in high performance frequency and timing distribution systems. With ultra-stable performance from one to three seconds, an Earth-orbit or moon-based MSAR can enhance available performance options for spacecraft due to elimination of atmospheric path degradation.

Wang, Rabi T.; Tjoelker, Robert L.

2011-01-01

452

Actinide extraction methods  

DOEpatents

Methods of separating actinides from lanthanides are disclosed. A regio-specific/stereo-specific dithiophosphinic acid having organic moieties is provided in an organic solvent that is then contacted with an acidic medium containing an actinide and a lanthanide. The method can extend to separating actinides from one another. Actinides are extracted as a complex with the dithiophosphinic acid. Separation compositions include an aqueous phase, an organic phase, dithiophosphinic acid, and at least one actinide. The compositions may include additional actinides and/or lanthanides. A method of producing a dithiophosphinic acid comprising at least two organic moieties selected from aromatics and alkyls, each moiety having at least one functional group is also disclosed. A source of sulfur is reacted with a halophosphine. An ammonium salt of the dithiophosphinic acid product is precipitated out of the reaction mixture. The precipitated salt is dissolved in ether. The ether is removed to yield the dithiophosphinic acid.

Peterman, Dean R. (Idaho Falls, ID) [Idaho Falls, ID; Klaehn, John R. (Idaho Falls, ID) [Idaho Falls, ID; Harrup, Mason K. (Idaho Falls, ID) [Idaho Falls, ID; Tillotson, Richard D. (Moore, ID) [Moore, ID; Law, Jack D. (Pocatello, ID) [Pocatello, ID

2010-09-21

453

The root extraction problem  

NASA Astrophysics Data System (ADS)

The Nth root extraction problem for germs of diffeomorphisms f :(C,0)?(C,0) is the problem of finding a germ of diffeomorphism g :(C,0)?(C,0) such that g=f, where g is the Nth iterate of g under composition. Depending on f and on the multiplier of g at the origin there can be formal and analytic obstructions to a solution of the problem. By considering an unfolding of f we explain these obstructions. Indeed each analytic obstruction corresponds to an accumulation of periodic points which, in turn, are an obstruction to taking an Nth root of the unfolding. We apply this to the problem of the section of a curvilinear angle in N equal parts in conformal geometry.

Rousseau, C.

454

Nuclear magnetic resonance methods for metabolic fluxomics.  

PubMed

Fluxomics, through its core methodology of metabolic flux analysis (MFA), enables quantification of carbon traffic through cellular biochemical pathways. Isotope labeling experiments aid MFA by providing information on intracellular fluxes, especially through parallel and cyclic pathways. Nuclear magnetic resonance (NMR) and mass spectrometry (MS) are two complementary methods to measure abundances of isotopomers generated in these experiments. 2-D [(13)C, (1)H] heteronuclear correlation NMR spectra can detect (13)C isotopes coupled to protons and thus noninvasively separate molecules and atoms with a specific isotopic content from a mixture of molecular species. Furthermore, the fine structures of the peaks in these spectra can reveal scalar couplings between chemically bonded carbon atoms in the sample, from which isotopomer abundances can be quantified. This chapter introduces methods for NMR sample preparation and spectral acquisition of 2-D [(13)C, (1)H] correlation maps, followed by a detailed presentation of methods to process the spectra and quantify isotopomer abundances. We explain the use of the software NMRViewJ for spectral visualization and processing, as well as MATLAB scripts developed by us for peak extraction, deconvolution of overlapping peaklets, and isotopomer abundance quantification. Finally, we discuss the applications of NMR-derived isotopomer data toward quantitatively understanding metabolic pathways. PMID:23417811

Nargund, Shilpa; Joffe, Max E; Tran, Dennis; Tugarinov, Vitali; Sriram, Ganesh

2013-01-01

455

Automatic breast border extraction  

NASA Astrophysics Data System (ADS)

In computer aided mammography algorithms there are several processing steps, which must be performed. The basic segmentation procedure involves extracting the principal feature on a mammogram; the breast border. This is performed by segmenting the breast and the non-breast into distinct regions. In this paper, a method for extracting the breast border is proposed. The method has performance similar to established techniques but with higher degrees of automatization and robustness. It iteratively adapts a model of the background to ensure a robust object detection yielding a smooth outline of the breast. The main idea is to identify the "knee" in the cumulative intensity histogram of the image. The intensity value at the knee is thereafter used to automatically define a region, to be modelled by a two-dimensional polynomial surface of degree two. The modelled background is then subtracted from the original image. The procedure described is iteratively performed until the degree of non-uniformity of the grey-scale background is smaller then a certain value. Thereafter the difference image is post-processed by a flood-filling algorithm, a new threshold is estimated as above and applied to yield a binary image. Lastly morphological operations are performed to smoothen the breast border. In conclusion, the strength in the proposed method, compared to similar methods, is that it makes use of an iterative approach to reduce the effects of the background, it produces smooth edges and automatically finds thresholds. It is also evaluated on the entire MIAS database (322 images) with a performance of 94%.

Olsen, Christina M.

2005-04-01

456

Quantification of High-Resolution 1H NMR Spectra from Rat Brain Extracts  

PubMed Central

Extracting quantitative information about absolute concentrations from high-resolution 1H NMR spectra of complex mixtures such as brain extracts remains challenging. Partial overlap of resonances complicates integration, whereas simple line fitting algorithms cannot accommodate the spectral complexity of coupled spin-systems. Here it is shown that high-resolution 1H NMR spectra of rat brain extracts from 11 distinct brain regions can be reproducibly quantified using a basis set of 29 compounds. The basis set is simulated with the density matrix formalism using complete prior knowledge of chemical shifts and scalar couplings. A crucial aspect to obtain reproducible results was the inclusion of a line shape distortion common among all 73 resonances of the 29 compounds. All metabolites could be quantified with <10% and <3% inter- and intrasubject variation, respectively.

de Graaf, Robin A.; Chowdhury, Golam M. I.; Behar, Kevin L.

2013-01-01

457

RNA extraction from plant tissues  

Microsoft Academic Search

Several protocols and commercial kits are used for the extraction of nucleic acids from different plant tissues. Although\\u000a there are several procedures available to remove sugars, which hinder the extraction of clean genomic DNA, there are few to\\u000a assist with extraction of RNA. Those presently used include precipitations with ethylene glycol monobutyl ether or lithium\\u000a chloride (LiCl), or centrifugation in

Valeriano Dal Cin; Marcello Danesin; Fabio Massimo Rizzini; Angelo Ramina

2005-01-01

458

Antioxidant activities of buckwheat extracts  

Microsoft Academic Search

The antioxidant activities of buckwheat (Fagopyrum esculentum Möench) extracts were evaluated and compared with butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tertiary butylhydroquinone (TBHQ) using a ?-carotene bleaching assay, a 2,2-diphenyl-?-picrylhydrazyl (DPPH) assay and the Rancimat method. Buckwheat was extracted with solvents of different polarities. The methanol extract showed the highest antioxidant activity coefficient (AAC) of 627±40.0 at 200 mg\\/l

Ting Sun; Chi-Tang Ho

2005-01-01

459

Taxonomic discrimination of cyanobacteria by metabolic fingerprinting using proton nuclear magnetic resonance spectra and multivariate statistical analysis  

Microsoft Academic Search

When whole-cell extracts are analyzed, proton nuclear magnetic resonance (1H NMR) spectroscopy provides biochemical profiles that contain overlapping signals of the majority of the compounds. To determine\\u000a whether cyanobacteria could be taxonomically discriminated on the basis of metabolic fingerprinting, we subjected whole-cell\\u000a extracts of the cyanobacteria to1H NMR. The1H NMR spectra revealed a predominance of signals in the aliphatic region.

Suk Weon Kim; Sung Hee Ban; Chi Yong Ahn; Hee Mock Oh; Hoeil Chung; Soo Hwa Cho; Young Mok Park; Jang Ryol Liu

2006-01-01

460

Stimulated raman scattering in micro sphere resonators  

NASA Astrophysics Data System (ADS)

Micro sphere resonators that hold optical whisper gallery modes (WGMs) provide an innovative option for implementing micro optical resonators. The unique properties of the micro sphere resonator make it capable to introduce resonance for various optical phenomenon, like stimulated Raman scattering (SRS), in micron scale. This thesis illustrates the characteristics of micro sphere resonators and demonstrates the resonance-enhanced SRS in micro sphere resonators with reduce threshold power. Both theoretical and experimental results are presented. Coupling model for WGM is derived in transfer matrix method. Simulation analyses for mode pattern of WGMs are solved based on mathematic model and finite element method (FEM). Fabrication of devices like silica binocular tapered fiber couplers and silica micro spheres is developed. The measurement setup is established, based on which characteristics of silica micro sphere resonators are measured. The result is compared to theoretical analysis to obtain the Q-factor of the resonator. The correspondence of the Q-factor on the coupling condition and the degradation of the Q factor over time are further discussed. SRS in silica micro sphere resonators is demonstrated with a reduced threshold power as low as 1 mW, which is 2 to 3 orders lower than that in fiber-based devices. Fabrication and measurement on chalcogenide glass micro sphere resonators are presented, according to which the threshold for SRS is also calculated. Further work is needed to improve the Q-factor of the chalcogenide glass micro sphere resonator for demonstrating the resonance-enhanced SRS in this material.

Zhang, Ruoyu

461

Dielectric Resonator Stabilized Microstrip Oscillator.  

National Technical Information Service (NTIS)

A microstrip L-band bipolar dielectric resonator stabilized oscillator (DRO) devised in a moderate size (2 ft. x 5 in. x 3.6 in.), low-cost, reproducible circuit. Embedment of back to back varactors in the DRO provide voltage tuning for phase lock applica...

E. E. Niehenke P. A. Green

1985-01-01

462

Nuclear Magnetic Resonance Massmetric Flowmeter.  

National Technical Information Service (NTIS)

Based on earlier research work in the measurement of jet and rocket propellants by means of Nuclear Magnetic Resonance (NMR), a propellant mass flow meter based on the NMR principle was designed and constructed. The mass flow measurement is derived by mul...

J. H. Battocletti W. H. Vander Heyden W. K. Genthe

1972-01-01

463

Electroweak-scale resonant leptogenesis  

NASA Astrophysics Data System (ADS)

We study minimal scenarios of resonant leptogenesis near the electroweak phase transition. These models offer a number of testable phenomenological signatures for low-energy experiments and future high-energy colliders. Our study extends previous analyses of the relevant network of Boltzmann equations, consistently taking into account effects from out of equilibrium sphalerons and single lepton flavors. We show that the effects from single lepton flavors become very important in variants of resonant leptogenesis, where the observed baryon asymmetry in the Universe is created by lepton-to-baryon conversion of an individual lepton number, for example, that of the ?-lepton. The predictions of such resonant ?-leptogenesis models for the final baryon asymmetry are almost independent of the initial lepton-number and heavy neutrino abundances. These models accommodate the current neutrino data and have a number of testable phenomenological implications. They contain electroweak-scale heavy Majorana neutrinos with appreciable couplings to electrons and muons, which can be probed at future e+e- and ?+?- high-energy colliders. In particular, resonant ?-leptogenesis models predict sizable 0??? decay, as well as e- and ?-number-violating processes, such as ??e? and ??e conversion in nuclei, with rates that are within reach of the experiments proposed by the MEG and MECO collaborations.

Pilaftsis, Apostolos; Underwood, Thomas E. J.

2005-12-01

464

Duffing's Equation and Nonlinear Resonance  

ERIC Educational Resources Information Center

The phenomenon of nonlinear resonance (sometimes called the "jump phenomenon") is examined and second-order van der Pol plane analysis is employed to indicate that this phenomenon is not a feature of the equation, but rather the result of accumulated round-off error, truncation error and algorithm error that distorts the true bounded solution onto…

Fay, Temple H.

2003-01-01

465

Nucleon Resonances from FLIC Fermions  

NASA Astrophysics Data System (ADS)

The Fat Link Irrelevant Clover (FLIC) fermion action and its associated phenomenology are described. The scaling analysis indicates FLIC fermions provide a new form of nonperturbative Oa) improvement where near-continuum results are obtained at finite lattice spacing. Spin-{1over 2} and spin-{3over 2}, even and odd parity nucleon resonances are investigated.

Leinweber, D.; Hedditch, J.; Melnitchouk, W.; Williams, A.; Zanotti, J.

466

Resonant photonic crystals and quasicrystals  

NASA Astrophysics Data System (ADS)

We discuss resonant photonic crystals and quasicrystals focusing on the quantum well (QW)-based structures. Formation of exciton-polaritons in the light-coupled Fibonacci QWs is demonstrated. Analytical two-wave approximation, allowing to obtain optical spectra and polaritonic band structure and to interpret experimental results, is presented.

Poddubny, Alexander N.

2012-05-01

467

Collective motion and giant resonances  

SciTech Connect

This book compiles the papers presented at the conference on the subject of collective motion and giant resonances. Specifically discussed topics are: Beta decay of nuclei and astrophysics; inner hole states and their fragmentation; quantum chrome-dynamics, nuclear reactions of uranium and collective excitations; electron-positron interactions and collective model.

Wilhelmi, Z.; Kicinska-Habior, M.

1986-01-01

468

Composite Resonator Surface Emitting Lasers  

SciTech Connect

The authors have developed electrically-injected coupled-resonator vertical-cavity lasers and have studied their novel properties. These monolithically grown coupled-cavity structures have been fabricated with either one active and one passive cavity or with two active cavities. All devices use a selectively oxidized current aperture in the lower cavity, while a proton implant was used in the active-active structures to confine current in the top active cavity. They have demonstrated optical modulation from active-passive devices where the modulation arises from dynamic changes in the coupling between the active and passive cavities. The laser intensity can be modulated by either forward or reverse biasing the passive cavity. They have also observed Q-switched pulses from active-passive devices with pulses as short as 150 ps. A rate equation approach is used to model the Q-switched operation yielding good agreement between the experimental and theoretical pulseshape. They have designed and demonstrated the operation of active-active devices which la.se simultaneously at both longitudinal cavity resonances. Extremely large bistable regions have also been observed in the light-current curves for active-active coupled resonator devices. This bistability can be used for high contrast switching with contrast ratios as high as 100:1. Coupled-resonator vertical-cavity lasers have shown enhanced mode selectivity which has allowed devices to lase with fundamental-mode output powers as high as 5.2 mW.

FISCHER,ARTHUR J.; CHOQUETTE,KENT D.; CHOW,WENG W.; ALLERMAN,ANDREW A.; GEIB,KENT M.

2000-05-01

469

Simulating the Resonant Acoustic Mixer.  

National Technical Information Service (NTIS)

This report utilizes a state-of-the-art multiphase physics computer code to develop a rationale and a procedure for simulating the fluid dynamics of the Resonant Acoustic Mixer. This type of mixer does not require the use of blades to create high shear in...

D. V. Nance

2013-01-01

470

Alfven Wave Resonance Cone Propagation  

Microsoft Academic Search

Using a 2.5-D code, we studied the propagation of inertial Alfven (IA) waves radiated from a localized oscillating source. Structure of the resonance cone in the fields, current, and density including nonlinear effects is investigated. Electron parallel drifts in the large current region generate secondary electrostatic waves affecting significant bulk heating as well as formation of elongated tail in the

I. Khazanov; N. Singh

2005-01-01

471

Transverse Bragg resonance laser amplifier  

Microsoft Academic Search

We propose and analyze a new type of optical amplifier that is formed by addition of gai