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1

2D Fractional Supersymmetry for Rational Conformal Field Theory. Application for Third-Integer Spin States  

E-print Network

A 2D- fractional supersymmetry theory is algebraically constructed. The Lagrangian is derived using an adapted superspace including, in addition to a scalar field, two fields with spins 1/3,2/3. This theory turns out to be a rational conformal field theory. The symmetry of this model goes beyond the super Virasoro algebra and connects these third-integer spin states. Besides the stress-momentum tensor, we obtain a supercurrent of spin 4/3. Cubic relations are involved in order to close the algebra; the basic algebra is no longer a Lie or a super-Lie algebra. The central charge of this model is found to be 5/3. Finally, we analyse the form that a local invariant action should take.

A. Perez; M. Rausch de Traubenberg; P. Simon

1996-03-22

2

2D fractional supersymmetry for rational conformal field theory application for third-integer spin states  

E-print Network

A 2D- fractional supersymmetry theory is algebraically constructed. The Lagrangian is derived using an adapted superspace including, in addition to a scalar field, two fields with spins 1/3,2/3. This theory turns out to be a rational conformal field theory. The symmetry of this model goes beyond the super Virasoro algebra and connects these third-integer spin states. Besides the stress-momentum tensor, we obtain a supercurrent of spin 4/3. Cubic relations are involved in order to close the algebra; the basic algebra is no longer a Lie or a super-Lie algebra. The central charge of this model is found to be 4/3. Finally, we analyse the form that a local invariant action should take.

Pérez, A; Simon, P; de Traubenberg, M Rausch

1996-01-01

3

Preliminaries toward studying resonant extraction from the Debuncher  

SciTech Connect

A recent proposal to detect {mu} {yields} e direct conversion at Fermilab asks for slow extraction of protons from the antiproton source, specifically from the Debuncher. [1] A third-integer resonance originally was considered for this, partly because of the Debuncher's three-fold symmetry and partly because its operational horizontal tune, {nu}{sub x} {approx} 9.765, is already within 0.1 of {nu}{sub x} = 29/3. Using a half integer resonance, {nu}{sub x} = 19/2, though not part of the original proposal, has been suggested more recently because (a) Fermilab has had a good deal of experience with half-integer extraction from the Tevatron, the Main Injector and the erstwhile Main Ring, and (b) for reasons we shall examine later, it depopulates the entire bunch without an abort at the end. This memo presents considerations preliminary to studying both possibilities. It is meant only as a starting point for investigations to be carried out in the future. The working constraints and assumptions have oscillated between two extremes: (1) making minimal changes in the antiproton source to minimize cost and (2) building another machine in the same tunnel. In this memo we adopt an attitude aligned more toward the first. The assumed parameters are listed in Table 1. A few are not (easily) subject to change, such as those related to the beam's momentum and revolution frequency and the acceptance of the debuncher. Two resonance exemplars are presented in the next section, with an explanation of the analytic and semi-analytic calculations that can be done for each. Section 3 contains preliminary numerical work that was done to validate the exemplars within the context of extraction from the Debuncher. A final section contains a summary. Following the bibliography, appendices contain (a) a qualitative, conceptual discussion of extraction for the novice, (b) a telegraphic review of the perturbative incantations used to filter the exemplars as principal resonances of quadrupole, sextupole and octupole distributions, (c) a brief discussion of linearly independent control circuits, and (d) two files describing the antiproton source's rings in MAD v.8 format, not readily available elsewhere. All figures are located at the end. We emphasize again, the work reported here barely begins the effort that will be required to design, validate and perform resonant extraction from the Debuncher. Our goal was to compile these preliminary notes in one place for easy future reference, preferably by a young, intelligent, motivated and energetic graduate student.

Michelotti, Leo; Johnstone, John; /Fermilab

2009-06-01

4

Space charge effect of the high intensity proton beam during the resonance extraction for the Mu2e experiment at Fermilab  

SciTech Connect

The proposed Mu2e experiment to search for direct {mu} {yields} e conversion at Fermilab plans slow, resonant extraction of a beam with 3 x 10{sup 12} protons from the Debuncher ring. Space charge of this high intensity beam is a critical factor, since it induces significant betatron tune spread and consequently affects resonance extraction processes, such as spill uniformity and beam losses. This study shows the multi-particle simulation results in the early stages of resonance extraction and spill uniformity in the presence of 2D and 3D space charge effects. We have presented the results of the third-integer resonance extraction in early stage for the Mu2e experiment in the presence of space charge effects. In order to track particles and to calculate self-consistent space charge effects, Synergia2 was used, which is capable of parallel computing. The space charge tune shift was computed and was reasonable value compared with the analytical calculation. Locations of the septum and Lambertson were chosen so that particles are kicked and extracted efficiently. The spill rates for with and without space charge effects were uniform, but should be improved for the early stage after the sextupole field ramping.

Park, Chong Shik; Amundson, James; Johnstone, John; Michelotti, Leo; Nagaslaev, Vladimir; Werkema, Steve; /Fermilab

2011-03-01

5

RESONANT EXTRACTION PARAMETERS FOR THE AGS BOOSTER.  

SciTech Connect

Brookhaven's AGS Booster is the injector for the AGS. It is being modified to send resonant extracted heavy ions to a new beam line, the Booster Applications Facility (BAF). The design of the resonant extraction system for BAF was described in [1]. This note will give a more detailed description of the system and describe the predicted resonant beam time structure. We will describe tune space manipulations necessary to extract the resonant beam at the maximum Booster rigidity, schemes for performing resonant extraction, and describe the modifications required to perform bunched beam extraction to the BAF facility.

BROWN,K.A.; CULLEN,J.; GLENN,J.W.; MAPES,M.; MARNERIS,I.; TSOUPAS,N.; SNYDSTRUP,L.; VAN ASSELT,W.

2001-06-18

6

Proposal for a new LEIR slow extraction scheme dedicated to biomedical research  

E-print Network

A proposal is here presented for a new slow extraction scheme for the Low Energy Ion Ring (LEIR) in the context of the feasibility study for a future biomedical research facility at CERN. The new slow extraction system is based on the third-integer resonance. Two resonance driving mechanisms have been studied: the quadrupole-driven method and the RF-knockout technique. Both were made compatible with the tight constraints imposed by parallel operation of LEIR as heavy ion accumulator and care was taken to maximize the use of the available hardware.

Garonna, A; Abler, D

2014-01-01

7

Extracting resonance parameters from lattice data  

NASA Astrophysics Data System (ADS)

Monte Carlo simulations of the 4d O(4) model in the broken phase are performed to determine the parameters of a resonance. The standard method for extracting them on the lattice is through L\\"uscher's formula; recently a new method, based on the probability distribution concept, has been proposed. We study the application of these methods and compare them with Monte Carlo data.

Giudice, P.; McManus, D.; Peardon, M. J.

8

Extracting resonance parameters from lattice data  

E-print Network

Monte Carlo simulations of the 4d O(4) model in the broken phase are performed to determine the parameters of a resonance. The standard method for extracting them on the lattice is through L\\"uscher's formula; recently a new method, based on the probability distribution concept, has been proposed. We study the application of these methods and compare them with Monte Carlo data.

Pietro Giudice; Darran McManus; Mike Peardon

2010-09-30

9

Wave energy extraction by coupled resonant absorbers.  

PubMed

In this article, a range of problems and theories will be introduced that will build towards a new wave energy converter (WEC) concept, with the acronym 'ROTA' standing for resonant over-topping absorber. First, classical results for wave power absorption for WECs constrained to operate in a single degree of freedom will be reviewed and the role of resonance in their operation highlighted. Emphasis will then be placed on how the introduction of further resonances can improve power take-off characteristics by extending the range of frequencies over which the efficiency is close to a theoretical maximum. Methods for doing this in different types of WECs will be demonstrated. Coupled resonant absorbers achieve this by connecting a WEC device equipped with its own resonance (determined from a hydrodynamic analysis) to a new system having separate mass/spring/damper characteristics. It is shown that a coupled resonant effect can be realized by inserting a water tank into a WEC, and this idea forms the basis of the ROTA device. In essence, the idea is to exploit the coupling between the natural sloshing frequencies of the water in the internal tank and the natural resonance of a submerged buoyant circular cylinder device that is tethered to the sea floor, allowing a rotary motion about its axis of attachment. PMID:22184664

Evans, D V; Porter, R

2012-01-28

10

AGS slow extracted beam improvement  

SciTech Connect

The Brookhaven AGS is a strong focusing accelerator which is used to accelerate protons and various heavy ion species to an equivalent proton energy of 29 GeV. Since the late 1960`s it has been serving high energy physics (HEP - proton beam) users of both slow and fast extracted beams. The AGS fixed target program presently uses primary proton and heavy ion beams (HIP) in slowly extracted fashion over spill lengths of 1.5 to 4.0 seconds. Extraction is accomplished by flattoping the main and extraction magnets and exciting a third integer resonance in the AGS. Over the long spill times, control of the subharmonic amplitude components up to a frequency of 1 kilohertz is very crucial. One of the most critical contributions to spill modulation is due to the AGS MMPS. An active filter was developed to reduce these frequencies and it`s operation is described in a previous paper. However there are still frequency components in the 60-720 Hz sub-harmonic ripple range, modulating the spill structure due to extraction power supplies and any remaining structures on the AGS MMPS. A recent scheme is being developed to use the existing tune-trim control horizontal quadrupole magnets and power supply to further reduce these troublesome noise sources. Feedback from an external beam sensor and overcoming the limitations of the quadrupole system by lead/lag compensation techniques will be described.

Marneris, I.; Danowski, G.; Sandberg, J.; Soukas, A.

1997-07-01

11

Proposal for a new LEIR Slow Extraction Scheme dedicated to Biomedical Research  

E-print Network

This report presents a proposal for a new slow extraction scheme for the Low Energy Ion Ring (LEIR) in the context of the feasibility study for a biomedical research facility at CERN. LEIR has to be maintained as a heavy ion accumulator ring for LHC and for fixed-target experiments with the SPS. In parallel to this on-going operation for physics experiments, an additional secondary use of LEIR for a biomedical research facility was proposed [Dosanjh2013, Holzscheiter2012, PHE2010]. This facility would complement the existing research beam-time available at other laboratories for studies related to ion beam therapy. The new slow extraction [Abler2013] is based on the third-integer resonance. The reference beam is composed of fully stripped carbon ions with extraction energies of 20-440 MeV/u, transverse physical emittances of 5-25 µm and momentum spreads of ±2-9•10-4. Two resonance driving mechanisms have been studied: the quadrupole-driven method and the RF-knockout technique. Both were made compatible...

Garonna, A; Carli, C

2014-01-01

12

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

13

Extracting Low-Lying Lambda Resonances Using Correlation Matrix Techniques  

E-print Network

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.

Benjamin J. Menadue; Waseem Kamleh; Derek B. Leinweber; M. S. Mahbub

2011-02-17

14

Extraction of second order piezoelectric parameters in bulk acoustic wave resonators  

NASA Astrophysics Data System (ADS)

In this paper we demonstrate a method to extract the electric field dependence of first order piezoelectric parameters. We fit the Mason model to measured frequency dependent electrical impedance data of aluminum-nitride bulk acoustic wave resonators for various DC biasing. The impedance was fitted accurately at the mechanical resonances and in the quasi-static regime well below the resonance frequency. This revealed the dependence of the piezoelectric stiffness, charge constant, and permittivity on the electric field. From this the four second order piezoelectric parameters were calculated.

van Hemert, Tom; Reimann, Klaus; Hueting, Raymond J. E.

2012-06-01

15

Extraction of Electromagnetic Transition Form Factors for Nucleon Resonances within a Dynamical Coupled-Channels Model  

SciTech Connect

We explain the application of a recently developed analytic continuation method to extract the electromagnetic transition form factors for the nucleon resonances ($N^*$) within a dynamical coupled-channel model of meson-baryon reactions.Illustrative results of the obtained $N^*\\rightarrow \\gamma N$ transition form factors, defined at the resonance pole positions on the complex energy plane, for the well isolated $P_{33}$ and $D_{13}$, and the complicated $P_{11}$ resonances are presented. A formula has been developed to give an unified representation of the effects due to the first two $P_{11}$ poles, which are near the $\\pi\\Delta$ threshold, but are on different Riemann sheets. We also find that a simple formula, with its parameters determined in the Laurent expansions of $\\pi N \\rightarrow \\pi N$ and $\\gamma N \\rightarrow\\pi N$ amplitudes, can reproduce to a very large extent the exact solutions of the considered model at energies near the real parts of the extracted resonance positions. We indicate the differences between our results and those extracted from the approaches using the Breit-Wigner parametrization of resonant amplitudes to fit the data.

N. Suzuki, T. Sato, T.-S. H. Lee

2010-10-01

16

Comparison of analysis techniques for extracting resonance parameters from lattice Monte Carlo data  

NASA Astrophysics Data System (ADS)

Different methods for extracting resonance parameters from Euclidean lattice field theory are tested. Monte Carlo simulations of the O(4) nonlinear sigma model are used to generate energy spectra in a range of different volumes both below and above the inelastic threshold. The applicability of the analysis methods in the elastic region is compared. Problems which arise in the inelastic region are also emphasized.

Giudice, Pietro; McManus, Darran; Peardon, Michael

2012-10-01

17

Model extraction from magnetic resonance volume data using the deformable pyramid  

Microsoft Academic Search

A general framework for automatic model extraction from magnetic resonance (MR) images is described. The framework is based on a two-stage algorithm. In the first stage, a geometrical and topological multiresolution prior model is constructed. It is based on a pyramid of graphs. In the second stage, a matching algorithm is described. This algorithm is used to deform the prior

Jyrki Lötjönen; Pierre-Jean Reissman; Isabelle E. Magnin; Toivo Katila

1999-01-01

18

Study on proton fraction of beams extracted from electron cyclotron resonance ion sourcea)  

NASA Astrophysics Data System (ADS)

A permanent magnet electron cyclotron resonance ion source PMECR II is used to generate proton ions for radio frequency quadrupole (RFQ) injection at Peking University (PKU). The proton fractions of the extracted beam were measured at the positions both after extraction system of ion source and the end of low energy beam transport line (LEBT). Experiments show that the proton fraction has a rise time within a beam pulse, and its value varies with pulse width and microwave power. The proton fractions measured at different positions are comparable.

Xu, R.; Zhao, J.; Peng, S. X.; Yuan, Z. X.; Song, Z. Z.; Yu, J. X.; Guo, Z. Y.

2008-02-01

19

Study on proton fraction of beams extracted from electron cyclotron resonance ion source  

SciTech Connect

A permanent magnet electron cyclotron resonance ion source PMECR II is used to generate proton ions for radio frequency quadrupole (RFQ) injection at Peking University (PKU). The proton fractions of the extracted beam were measured at the positions both after extraction system of ion source and the end of low energy beam transport line (LEBT). Experiments show that the proton fraction has a rise time within a beam pulse, and its value varies with pulse width and microwave power. The proton fractions measured at different positions are comparable.

Xu, R.; Zhao, J.; Peng, S. X.; Yuan, Z. X.; Song, Z. Z.; Yu, J. X.; Guo, Z. Y. [State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China)

2008-02-15

20

Evolution of beam distribution in crossing a Walkinshaw resonance.  

PubMed

The third-integer coupling resonance at ?(x)-2?(z)=?, known as the Walkinshaw resonance, is important in high-power accelerators. We find that, when the betatron tunes ramp through a Walkinshaw resonance the fractional emittance growth (FEG) is a universal function of the effective resonance strength: G(1,-2,?)?[?(xi)]|?(?(x)-2?(z))/?n|(-1/2), where G(1,-2,?) is the resonance strength; ?(xi) and ?(zi) are the initial horizontal and vertical emittances, respectively; and |?(?(x)-2?(z))/?n| is the resonance crossing rate per revolution. At large effective resonance strengths, the FEG reaches an asymptotic maximum value (FEG)(max)~2?(xi)/?(zi) for ?(xi)>1/2?(zi) or ?(zi)/(2?(xi)) for ?(xi)<1/2?(zi). There is little emittance exchange at ?(xi)=1/2?(z), which can be used to minimize emittance growth in crossing a Walkinshaw resonance. PMID:23496717

Lee, S Y; Ng, K Y; Liu, H; Chao, H C

2013-03-01

21

Measurement of Optical Response of a Detuned Resonant Sideband Extraction Interferometer  

E-print Network

We report on the optical response of a suspended-mass detuned resonant sideband extraction (RSE) interferometer with power recycling. The purpose of the detuned RSE configuration is to manipulate and optimize the optical response of the interferometer to differential displacements (induced by gravitational waves) as a function of frequency, independently of other parameters of the interferometer. The design of our interferometer results in an optical gain with two peaks: an RSE optical resonance at around 4 kHz and a radiation pressure induced optical spring at around 41 Hz. We have developed a reliable procedure for acquiring lock and establishing the desired optical configuration. In this configuration, we have measured the optical response to differential displacement and found good agreement with predictions at both resonances and all other relevant frequencies. These results build confidence in both the theory and practical implementation of the more complex optical configuration being planned for Advanced LIGO.

Osamu Miyakawa; Robert Ward; Rana Adhikari; Matthew Evans; Benjamin Abbott; Rolf Bork; Daniel Busby; Jay Heefner; Alexander Ivanov; Michael Smith; Robert Taylor; Stephen Vass; Alan Weinstein; Monica Varvella; Seiji Kawamura; Fumiko Kawazoe; Shihori Sakata; Conor Mow-Lowry

2006-04-18

22

Detection of free radicals in aqueous extracts of cigarette tar by electron spin resonance  

Microsoft Academic Search

Aqueous extracts of cigarette tar (ACT) autooxidize to produce semiquinone, hydroxyl, and superoxide radicals in air-saturated buffered aqueous solutions. The semiquinone species were detected by direct electron spin resonance (ESR) measurements and identified as o-and p-benzosemiquinone radicals by comparison with the ESR signals of catechol and hydroquinone radicals under similar conditions. The rate of formation of these radicals was dependent

Lun-Yi Zang; Koni Stone; William A. Pryor

1995-01-01

23

Polarizability extraction for rapid computation of Fano resonance in nanoring lattices  

NASA Astrophysics Data System (ADS)

Rapid modeling of far-field Fano resonance supported by lattices of complex nanostructures is possible with the coupled dipole approximation (CDA) using point, dipole polarizability extrapolated from a higher order discrete dipole approximation (DDA). Fano resonance in nanostructured metamaterials has been evaluated with CDA for spheroids, for which an analytical form of particle polarizability exists. For complex structures with non-analytic polarizability, such as rings, higher order electrodynamic solutions must be employed at the cost of computation time. Point polarizability is determined from the DDA by summing individual polarizable volume elements from the modeled structure. Extraction of single nanoring polarizability from DDA permitted CDA analysis of nanoring lattices with a 40,000-fold reduction in computational time over 1000 wavelengths. Maxima and minima of predicted Fano resonance energies were within 1% of full volume elements using the DDA. This modeling technique is amenable to other complex nanostructures which exhibit primarily dipolar and/or quadrupolar resonance behavior. Rapid analysis of coupling between plasmons and photon diffraction modes in lattices of nanostructures supports design of plasmonic enhancements in sustainable energy and biomedical devices.

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

2014-09-01

24

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

NASA Astrophysics Data System (ADS)

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 probe to indicate the seasonal variations of lightning activity in three main thunderstorm regions (Africa, southeast Asia, and South America). An inverse method based on genetic algorithms is developed to extract information on lightning intensity in these three regions from observed SR intensity data. Seasonal variations of the lightning activity in three thunderstorm centers are clearly observed in our results. Different SR frequency variations associated with seasonal variations of global lighting activity are also discussed.

Yang, Heng; Pasko, Victor P.; SáTori, Gabriella

2009-01-01

25

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

26

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

E-print Network

Magnification of photonic crystal fluorescence enhancement via TM resonance excitation and TE.1088/0957-4484/21/12/125203 Magnification of photonic crystal fluorescence enhancement via TM resonance excitation and TE resonance. Introduction Fluorescence-based biological assays are used widely for measurements in life-science research

Cunningham, Brian

27

Study of ion beam extraction and transport from an electron cyclotron resonance ion source.  

PubMed

We have started an experimental and theoretical program to better understand the extraction and transport of intense multiply charged ion beams from an electron cyclotron resonance ion source (ECRIS). In this paper we present the first results of this program concerning a simple, monocomponent He(+) beam extracted from an ECRIS. We have calculated the ion trajectories starting from the ECRIS plasma electrode up to the image plane of the analyzing magnet taking into account space-charge effects and fringe fields. The initial phase-space distribution of the He(+) beam at the extraction aperture has been calculated with a particle-in-cell code. To check the simulations we have measured beam profiles with a viewing screen both before and after the analyzing magnet. In addition also measurements with a pepperpot emittance meter located behind the analyzing magnet have been performed. We find good agreement between these measurements and simulations showing that (i) there is a significant compensation of the space charge and that (ii) our analyzing magnet causes a severe increase in effective beam emittance. PMID:20192446

Saminathan, S; Mironov, V; Beijers, J P M; Kremers, R; Brandenburg, S

2010-02-01

28

Resonance  

NSDL National Science Digital Library

For advanced undergraduate students: Observe resonance in a collection of driven, damped harmonic oscillators. Vary the driving frequency and amplitude, the damping constant, and the mass and spring constant of each resonator. Notice the long-lived transients when damping is small, and observe the phase change for resonators above and below resonance.

Simulations, Phet I.; Dubson, Michael; Loeblein, Patricia; Olson, Jonathan; Perkins, Kathy; Gratny, Mindy

2011-07-20

29

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

30

Beam extraction and high stability operation of high current electron cyclotron resonance proton ion source  

NASA Astrophysics Data System (ADS)

A high current electron cyclotron resonance proton ion source is designed and developed for the low energy high intensity proton accelerator at Bhabha Atomic Research Centre. The plasma discharge in the ion source is stabilized by minimizing the reflected microwave power using four stub auto tuner and magnetic field. The optimization of extraction geometry is performed using PBGUNS code by varying the aperture, shape, accelerating gap, and the potential on the electrodes. While operating the source, it was found that the two layered microwave window (6 mm quartz plate and 2 mm boron nitride plate) was damaged (a fine hole was drilled) by the back-streaming electrons after continuous operation of the source for 3 h at beam current of 20-40 mA. The microwave window was then shifted from the line of sight of the back-streaming electrons and located after the water-cooled H-plane bend. In this configuration the stable operation of the high current ion source for several hours is achieved. The ion beam is extracted from the source by biasing plasma electrode, puller electrode, and ground electrode to +10 to +50 kV, -2 to -4 kV, and 0 kV, respectively. The total ion beam current of 30-40 mA is recorded on Faraday cup at 40 keV of beam energy at 600-1000 W of microwave power, 800-1000 G axial magnetic field and (1.2-3.9) × 10-3 mbar of neutral hydrogen gas pressure in the plasma chamber. The dependence of beam current on extraction voltage, microwave power, and gas pressure is investigated in the range of operation of the ion source.

Roychowdhury, P.; Mishra, L.; Kewlani, H.; Patil, D. S.; Mittal, K. C.

2014-03-01

31

Beam extraction and high stability operation of high current electron cyclotron resonance proton ion source.  

PubMed

A high current electron cyclotron resonance proton ion source is designed and developed for the low energy high intensity proton accelerator at Bhabha Atomic Research Centre. The plasma discharge in the ion source is stabilized by minimizing the reflected microwave power using four stub auto tuner and magnetic field. The optimization of extraction geometry is performed using PBGUNS code by varying the aperture, shape, accelerating gap, and the potential on the electrodes. While operating the source, it was found that the two layered microwave window (6 mm quartz plate and 2 mm boron nitride plate) was damaged (a fine hole was drilled) by the back-streaming electrons after continuous operation of the source for 3 h at beam current of 20-40 mA. The microwave window was then shifted from the line of sight of the back-streaming electrons and located after the water-cooled H-plane bend. In this configuration the stable operation of the high current ion source for several hours is achieved. The ion beam is extracted from the source by biasing plasma electrode, puller electrode, and ground electrode to +10 to +50 kV, -2 to -4 kV, and 0 kV, respectively. The total ion beam current of 30-40 mA is recorded on Faraday cup at 40 keV of beam energy at 600-1000 W of microwave power, 800-1000 G axial magnetic field and (1.2-3.9) × 10(-3) mbar of neutral hydrogen gas pressure in the plasma chamber. The dependence of beam current on extraction voltage, microwave power, and gas pressure is investigated in the range of operation of the ion source. PMID:24689571

Roychowdhury, P; Mishra, L; Kewlani, H; Patil, D S; Mittal, K C

2014-03-01

32

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

33

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

34

Magnetic Resonance Imaging of Nonaqueous Phase Liquid During Soil Vapor Extraction in Heterogeneous Porous Media  

NASA Astrophysics Data System (ADS)

Soil vapor extraction (SVE) is commonly used to remediate nonaqueous phase liquids (NAPLs) from the vadose zone. This research aims to determine the effect of grain size heterogeneity on the removal of NAPL in porous media during SVE. Magnetic resonance imaging (MRI) was used to observe and quantify the amount and location of NAPL in flow through columns filled with silica gel grains. MRI is unique because it is non-destructive, allowing three-dimensional images to be taken of the phases as a function of space and time. Columns were packed with silica gel in three ways: coarse grains (250-550 mm) only, fine grains (32-63 mm) only, and a core of fine grains surrounded by a shell of coarse grains. Columns saturated with water were drained under a constant suction head, contaminated with decane, and then drained to different decane saturations. Each column was then continuously purged with water saturated nitrogen gas and images were taken intermittently. Results showed that at residual saturation a sharp volatilization front moved through the columns filled with either coarse or fine grain silica gel. In the heterogeneous column the volatilization front in the core lagged behind the shell because flow was through the shell and decane in the core diffused outward to the shell. When decane saturation in fine grains was above residual saturation, decane volatilization occurred near the inlet, and decane in the core moved to the shell to replenish volatilized decane. These results indicate that NAPL trapped in low permeability zones can spread to replenish areas where NAPL is lost due to SVE. However, when residual NAPL saturation is reached spreading no longer occurs and diffusion limits removal from low permeability zones.

Chu, Y.; Werth, C. J.; Valocchi, A. J.; Webb, A.

2002-12-01

35

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

SciTech Connect

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.

Delferriere, O.; Gobin, R.; Harrault, F.; Nyckees, S.; Sauce, Y.; Tuske, O. [Commissariat a l'Energie Atomique, CEA/Saclay, DSM/IRFU, 91191 Gif/Yvette (France)

2012-02-15

36

Molecular characterization of inhibiting biochar water-extractable substances using electrospray ionization fourier transform ion cyclotron resonance mass spectrometry.  

PubMed

Biochar has gained significant interest worldwide for its potential use as both a carbon sequestration technique and soil amendment. Recently, research has shown that pinewood-derived biochar water extracts inhibited the growth of aquatic photosynthetic microorganisms, both prokaryotic and eukaryotic algae, while chicken litter- and peanut shell-derived biochar water extracts showed no growth inhibition. With the use of electrodialysis, the pinewood-derived biochar water extract is separated into 3 fractions (anode-isolated, center chamber retained, and cathode-isolated substances) all with varying toxic effects. Because of its ultrahigh resolution and mass precision, electrospray ionization (ESI) coupled to Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) is utilized in this study to analyze biochar water extracts at a molecular level to enhance our understanding of the toxic nature of pinewood-derived biochar water extracts as compared to benign peanut shell-derived biochar water extracts. The molecular composition of pinewood-derived biochar water extracts shows unique carbohydrate ligneous components and sulfur containing condensed ligneous components that are both absent from the peanut shell water extracts and more prevalent in the anode-isolated substances. Using Kendrick mass defect analysis, we also determine that the most likely inhibitor species contain carboxyl and hydroxyl homologous series, both of which are characteristic functional groups hypothesized in our previous research for the inhibitor species. We have suggested that inhibition of aquatic photosynthetic microorganism growth is most likely due to degraded lignin-like species rich in oxygen containing functionalities. From the study conducted here, we show the potential of ultrahigh resolution FTICR-MS as a valuable analytical technique for determining whether certain biochars are safe and benign for use as carbon sequestration and soil amendment. PMID:24180747

Smith, Cameron R; Sleighter, Rachel L; Hatcher, Patrick G; Lee, James W

2013-12-01

37

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

38

Spatially resolved charge-state and current-density distributions at the extraction of an electron cyclotron resonance ion source  

SciTech Connect

In this paper we present our measurements of charge-state and current-density distributions performed in very close vicinity (15 mm) of the extraction of our hexapole geometry electron cyclotron resonance ion source. We achieved a relatively high spatial resolution reducing the aperture of our 3D-movable extraction (puller) electrode to a diameter of only 0.5 mm. Thus, we are able to limit the source of the extracted ion beam to a very small region of the plasma electrode's hole (O = 4 mm) and therefore to a very small region of the neutral plasma sheath. The information about the charge-state distribution and the current density in the plane of the plasma electrode at each particular position is conserved in the ion beam. We determined the total current density distribution at a fixed coaxial distance of only 15 mm to the plasma electrode by remotely moving the small-aperture puller electrode which contained a dedicated Faraday cup (FC) across the aperture of the plasma electrode. In a second measurement we removed the FC and recorded m/q-spectra for the different positions using a sector magnet. From our results we can deduce that different ion charge-states can be grouped into bloated triangles of different sizes and same orientation at the extraction with the current density peaking at centre. This confirms observations from other groups based on simulations and emittance measurements. We present our measurements in detail and discuss possible systematic errors.

Panitzsch, Lauri; Peleikis, Thies; Stalder, Michael; Wimmer-Schweingruber, Robert F. [Institute for Experimental and Applied Physics (IEAP), Christian-Albrechts-Universitaet, Kiel (Germany)

2011-09-15

39

Spatially resolved charge-state and current-density distributions at the extraction of an electron cyclotron resonance ion source  

NASA Astrophysics Data System (ADS)

In this paper we present our measurements of charge-state and current-density distributions performed in very close vicinity (15 mm) of the extraction of our hexapole geometry electron cyclotron resonance ion source. We achieved a relatively high spatial resolution reducing the aperture of our 3D-movable extraction (puller) electrode to a diameter of only 0.5 mm. Thus, we are able to limit the source of the extracted ion beam to a very small region of the plasma electrode's hole (Ø = 4 mm) and therefore to a very small region of the neutral plasma sheath. The information about the charge-state distribution and the current density in the plane of the plasma electrode at each particular position is conserved in the ion beam. We determined the total current density distribution at a fixed coaxial distance of only 15 mm to the plasma electrode by remotely moving the small-aperture puller electrode which contained a dedicated Faraday cup (FC) across the aperture of the plasma electrode. In a second measurement we removed the FC and recorded m/q-spectra for the different positions using a sector magnet. From our results we can deduce that different ion charge-states can be grouped into bloated triangles of different sizes and same orientation at the extraction with the current density peaking at centre. This confirms observations from other groups based on simulations and emittance measurements. We present our measurements in detail and discuss possible systematic errors.

Panitzsch, Lauri; Peleikis, Thies; Stalder, Michael; Wimmer-Schweingruber, Robert F.

2011-09-01

40

Spatially resolved charge-state and current-density distributions at the extraction of an electron cyclotron resonance ion source.  

PubMed

In this paper we present our measurements of charge-state and current-density distributions performed in very close vicinity (15 mm) of the extraction of our hexapole geometry electron cyclotron resonance ion source. We achieved a relatively high spatial resolution reducing the aperture of our 3D-movable extraction (puller) electrode to a diameter of only 0.5 mm. Thus, we are able to limit the source of the extracted ion beam to a very small region of the plasma electrode's hole (Ø = 4 mm) and therefore to a very small region of the neutral plasma sheath. The information about the charge-state distribution and the current density in the plane of the plasma electrode at each particular position is conserved in the ion beam. We determined the total current density distribution at a fixed coaxial distance of only 15 mm to the plasma electrode by remotely moving the small-aperture puller electrode which contained a dedicated Faraday cup (FC) across the aperture of the plasma electrode. In a second measurement we removed the FC and recorded m/q-spectra for the different positions using a sector magnet. From our results we can deduce that different ion charge-states can be grouped into bloated triangles of different sizes and same orientation at the extraction with the current density peaking at centre. This confirms observations from other groups based on simulations and emittance measurements. We present our measurements in detail and discuss possible systematic errors. PMID:21974580

Panitzsch, Lauri; Peleikis, Thies; Stalder, Michael; Wimmer-Schweingruber, Robert F

2011-09-01

41

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

42

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

43

Carbon beam extraction with 14.5 GHz electron cyclotron resonance ion source at Korea Atomic Energy Research Institutea)  

NASA Astrophysics Data System (ADS)

A 14.5 GHz Electron Cyclotron Resonance ion source (ECRIS) has been made to produce C4+ beam for using a carbon therapy facility and recently tested at KAERI. Highly charged carbon ions have been successfully extracted. When using only CO2 gas, the beam current of C4+ was almost 14 ?A at 15 kV extraction voltage. To get higher current of the C4+ beam, while optimizing confinement magnetic field configuration (e.g., axial strengths at minimum and extraction side), gas-mixing (CO2/He), and biased disk were introduced. When the gas mixing ratio of the CO2/He gas is 1:8 at an operational pressure of 5 × 10-7 mbar and the disk was biased to -150 V relative to the ion source body, the highest current of the C4+ beam was achieved to be 50 ?A, more than three times higher than previously observed only with CO2 gas. Some details on the operating conditions of the ECRIS were discussed.

Lee, Cheol Ho; Oh, Byung-Hoon; Chang, Dae-Sik; Jeong, Sun-Chan

2014-02-01

44

Carbon beam extraction with 14.5 GHz electron cyclotron resonance ion source at Korea Atomic Energy Research Institute.  

PubMed

A 14.5 GHz Electron Cyclotron Resonance ion source (ECRIS) has been made to produce C(4+) beam for using a carbon therapy facility and recently tested at KAERI. Highly charged carbon ions have been successfully extracted. When using only CO2 gas, the beam current of C(4+) was almost 14 ?A at 15 kV extraction voltage. To get higher current of the C(4+) beam, while optimizing confinement magnetic field configuration (e.g., axial strengths at minimum and extraction side), gas-mixing (CO2/He), and biased disk were introduced. When the gas mixing ratio of the CO2/He gas is 1:8 at an operational pressure of 5 × 10(-7) mbar and the disk was biased to -150 V relative to the ion source body, the highest current of the C(4+) beam was achieved to be 50 ?A, more than three times higher than previously observed only with CO2 gas. Some details on the operating conditions of the ECRIS were discussed. PMID:24593482

Lee, Cheol Ho; Oh, Byung-Hoon; Chang, Dae-Sik; Jeong, Sun-Chan

2014-02-01

45

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

PubMed

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. PMID:22225210

Maimone, F; Celona, L; Lang, R; Mäder, J; Rossbach, J; Spädtke, P; Tinschert, K

2011-12-01

46

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

47

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

48

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

NASA Astrophysics Data System (ADS)

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.; Celona, L.; Lang, R.; Mäder, J.; Roßbach, J.; Spädtke, P.; Tinschert, K.

2011-12-01

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. PMID:24177674

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

2013-01-01

50

Efficient screening of marine extracts for protease inhibitors by combining FRET based activity assays and surface plasmon resonance spectroscopy based binding assays.  

PubMed

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. PMID:24177674

Christopeit, Tony; Øverbø, Kersti; Danielson, U Helena; Nilsen, Inge W

2013-01-01

51

Sequential application of viscous opening and lower leveling for three-dimensional brain extraction on magnetic resonance imaging T1  

NASA Astrophysics Data System (ADS)

A composition of the viscous opening and the lower leveling is introduced to extract brain in magnetic resonance imaging T1. The innovative transformation disconnects chained components and has better control on the reconstruction process of the marker inside of the original image. However, the sequential operator requires setting several parameters, making its application difficult. Due to this situation, a simplification is carried out on it to obtain a more practical method. The proposed morphological transformations were tested with the Internet Brain Segmentation Repository (IBSR) database, which is used as a benchmark among the community. The results are compared using the Jaccard and Dice indices with respect to (i) manual segmentations obtained from the IBSR, (ii) mean indices reported in the current literature, and (iii) segmentations obtained from the Brain Extraction Tool, since this is one of the most popular algorithms used for brain segmentation. The average indices of Jaccard and Dice indicate that the reduced transformation produces similar results to the other methods reported in the literature while the sequential operator presents a better performance.

Mendiola-Santibañez, Jorge Domingo; Gallegos-Duarte, Martín; Arias-Estrada, Miguel Octavio; Santillán-Méndez, Israel Marcos; Rodríguez-Reséndiz, Juvenal; Terol-Villalobos, Iván Ramón

2014-05-01

52

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

53

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

SciTech Connect

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. [CIRIL, avenue Henri Becquerel, BP 5133, F-14070 Caen cedex 05 (France); ATOMKI, Bem ter 18/c, H-4026 Debrecen (Hungary); GANIL, Bd H. Becquerel BP 55027, F-14076 Caen cedex 05 (France); CEA/Saclay, DSM/DAPNIA, 91191 Gif/Yvette (France)

2008-02-15

54

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 Physics.  

PubMed

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. PMID:24593475

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

2014-02-01

55

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. PMID:21980222

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

2011-01-01

56

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

57

Determination of phosphate compounds in meat products by 31Phosphorus Nuclear Magnetic Resonance spectroscopy with methylenediphosphonic acid after alkaline extraction  

Microsoft Academic Search

Modification of the extraction procedure and application of the 31P NMR method for the determination of polyphosphates in meat products were studied. In the elaborated procedure threefold water extraction at alkaline pH (borate buffer and 0.1M EDTA) was applied. Furthermore, the new external standard for 31P NMR determination of phosphates was proposed. Obtained recoveries were between 95 and 99% and

P. Hrynczyszyn; A. Jastrz?bska; E. Sz?yk

2010-01-01

58

The influence of the extraction voltage on the energetic electron population of an electron cyclotron resonance ion source plasmaa)  

NASA Astrophysics Data System (ADS)

An influence of the extraction voltage on the high energy slope of bremsstrahlung radiation spectra has been reported in ECRIS experiments, which is not well understood so far. In order to provide more detailed data on this effect, we have measured bremsstrahlung radiation spectra accompanying especially the evolution of highly charge ions (i.e., by monitoring the Ar14+ charge state) as the extraction voltage is changed from 0 to 20 kV, in dedicated experiments at the Frankfurt 14 GHz-ECRIS.

Stiebing, K. E.; Schächter, L.; Dobrescu, S.

2012-02-01

59

Determination of phosphate compounds in meat products by 31-phosphorus nuclear magnetic resonance spectroscopy with methylenediphosphonic acid after alkaline extraction.  

PubMed

Modification of the extraction procedure and application of the (31)P NMR method for the determination of polyphosphates in meat products were studied. In the elaborated procedure threefold water extraction at alkaline pH (borate buffer and 0.1 M EDTA) was applied. Furthermore, the new external standard for (31)P NMR determination of phosphates was proposed. Obtained recoveries were between 95 and 99% and variation coefficients (CV) was < or = 5%, indicating an increase in accuracy and the precision of the proposed procedure in relation to the spectrophotometric method. The described procedure of sample preparation with (31)P NMR method was applied for the determination of polyphosphate additives in meat products. The satisfactory precision (CV=0.39-3.40%) shows the benefit of the NMR method in the routine analysis of the phosphate ions in meat products. PMID:20630180

Hrynczyszyn, P; Jastrzebska, A; Sz?yk, E

2010-07-12

60

Extracting partial decay rates of helium from complex rotation: autoionizing resonances of the one-dimensional configurations  

E-print Network

Partial autoionization rates of doubly excited one-dimensional helium in the collinear Zee and eZe configuration are obtained by means of the complex rotation method. The approach presented here relies on a projection of back-rotated resonance wave functions onto singly ionized $\\textrm{He}^{+}$ channel wave functions and the computation of the corresponding particle fluxes. In spite of the long-range nature of the Coulomb potential between the electrons and the nucleus, an asymptotic region where the fluxes are stationary is clearly observed. Low-lying doubly excited states are found to decay predomintantly into the nearest single-ionization continuum. This approach paves the way for a systematic analysis of the decay rates observed in higher-dimensional models, and of the role of electronic correlations and atomic structure in recent photoionization experiments.

Zimmermann, Klaus; Jörder, Felix; Heitz, Nicolai; Schmidt, Maximilian; Bouri, Celsus; Rodriguez, Alberto; Buchleitner, Andreas

2014-01-01

61

Extracting amplitudes from photoproduction data  

NASA Astrophysics Data System (ADS)

We consider the problems associated with amplitude extraction, from meson photoproduction data, over the first resonance regions. The notion of a complete experiment has motivated the FROST program at Jefferson Lab. Exercises applied to pion photoproduction data illustrate the problems to be confronted in any attempt to extract underlying resonance signals from these data (without introducing a model for the resonant process).

Workman, R. L.

2011-09-01

62

High resolution ¹?F{¹H} nuclear magnetic resonance spectroscopy and liquid chromatography-solid phase extraction-offline ¹H nuclear magnetic resonance spectroscopy for conclusive detection and identification of cyanide in water samples.  

PubMed

We report herein a new, sensitive and efficient method for detection, identification and quantification of cyanide in water samples. Cyanide was converted (>95% yield) to its versatile and stable derivative, 1-cyano-2,2,2-trifluoro-1-phenylethyl acetate (CTPA).The crude reaction mixture was directly subjected to high resolution fluorine-19 nuclear magnetic resonance ((19)F{(1)H} NMR) spectroscopy. In order to do away with signal overlap and dynamic range problems associated with (1)H NMR spectroscopy, liquid chromatography with UV detection hyphenated to online solid phase extraction (LC-UV-SPE) was performed. The trapped and enriched CTPA was thereafter subjected to offline (1)H NMR spectroscopy. In this way the ?(1)H, ?(19)F spectral signatures and LC-UV retention time were used for specific detection and identification and quantification of cyanide. The three techniques (viz. LC-UV and LC-UV-SPE followed by offline (1)H NMR and (19)F{(1)H} NMR spectroscopy) demonstrated good linearity (r(2)>0.99), reproducibility (inter-day RSD: 1.43-1.89%, 2.60-2.80%, 1.42-1.60; intra-day: RSD 1.20-1.38%, 3.21-3.25%, 1.00-1.19%), accuracy (recoveries: 95.1-97.2%, 77.5-82.8%, 96.8-98.9%) and LODs (1.31 ?g/mL, 4.24 ?g/mL, and 2.14 ?g/mL) respectively. Total time required for the analysis was ?3 h. Utility of the method was demonstrated by the detection and identification of spiked water samples. Since the derivative CTPA was volatile, could also be analyzed by GC-MS and GC-FTIR instruments. PMID:23453678

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

2013-04-01

63

Non-targeted analysis of wastewater treatment plant effluents by high performance liquid chromatography-time slice-solid phase extraction-nuclear magnetic resonance/time-of-flight-mass spectrometry.  

PubMed

Extracts of effluents from two different wastewater treatment plants (WWTP) in Switzerland taken during the application period of pesticides were examined by coupling an HPLC-MS system to a nuclear magnetic resonance spectrometer using a post column peak trapping device. By trapping 1 min portions of the chromatogram onto post column solid phase extraction cartridges (time slice-SPE-NMR) a comprehensive overview of proton carrying constituents could be achieved. Non-supervised statistical analysis of the NMR spectra obtained by this approach revealed NMR resonances pointing to contaminants present in decreasing proton concentration in the extracts. Comparison of exact mass data acquired during the trapping process to these NMR resonances enabled the identification of the pesticides Linuron, Metazachlor, Ethofumesate, Isoproturon, Metamitron, Propazine and Chloridazon. Desaminometamitron, a known transformation product of Metamitron could also be identified together with unexpected highly concentrated C8, C10 and C12 fatty acids and their glycerol mono- and di esters. Other compounds identified were a drug metabolite (3-Carboxymefenamic acid), a sun screen agent (Ensulizole: 2-Phenyl-1H-1,3-benzodiazole-6-sulfonic acid) and industrial chemicals (Benzotriazole, N-Benzyl-indole). In addition, a number of well-resolved proton spectra cannot be attributed to a mass response showing the need of further investigations using 2D-NMR and different ionization techniques. PMID:22098937

Godejohann, Markus; Berset, Jean-Daniel; Muff, Daniel

2011-12-23

64

Object extraction Object extraction  

E-print Network

Object extraction #12;Object extraction · Extracting topographic objects from images · the main goal of aerial photogrammetry · object extraction consists of two steps · image interpretation extraction · Extracting topographic objects from images · identify all objects of a certain class · measure

Giger, Christine

65

Resonances and resonance widths  

SciTech Connect

Two-dimensional betatron resonances are much more important than their simple one-dimensional counterparts and exhibit a strong dependence on the betatron phase advance per cell. A practical definition of ''width'' is expanded upon in order to display these relations in tables. A primarily pedagogical introduction is given to explain the tables, and also to encourage a wider capability for deriving resonance behavior and wider use of ''designer'' resonances.

Collins, T.

1986-05-01

66

Resonance Production in Jet  

E-print Network

Hadronic resonances with short life times and strong coupling to the dense medium may exhibit mass shifts and width broadening as signatures of chiral symmetry restoration at the phase transition between hadronic and partonic matter. Resonances with different lifetimes are also used to extract information about the time evolution and temperature of the expanding hadronic medium. In order to collect information about the early stage (at the phase transition) of a heavy-ion collision, resonances and decay particles which are unaffected by the hadronic medium have to be used. We explore a possible new technique to extract signals from the early stage through the selection of resonances from jets. A first attempt of this analysis, using the reconstructed $\\phi$(1020) from 200 GeV Au+Au collisions in STAR, is presented.

Christina Markert "for the" STAR Collaboration

2007-06-05

67

Analysis of a ginger extract by high-performance liquid chromatography coupled to nuclear magnetic resonance spectroscopy using superheated deuterium oxide as the mobile phase  

Microsoft Academic Search

A methanolic extract of powdered ginger was separated on a Xterra RP 18 column using deuterium oxide as the eluent and a temperature gradient from 50 to 130°C at 4°C\\/min. On-line and off-line HPLC–NMR analysis yielded spectra for vanillin, dihydroferulic acid, zingerone and ferulic acid. The identification of dihydroferulic acid and zingerone were confirmed by mass spectroscopy.

Shikha Saha; Roger M Smith; Eva Lenz; Ian D Wilson

2003-01-01

68

Feature extraction Feature extraction  

E-print Network

(hyperspectral sensors) Meteosat thermal IR channel hyperspectral "image cube" #12;Raw intensities · ProsFeature extraction #12;Feature extraction · Image interpretation: extract information from images · but the desired information may not be explicit in the raw observed pixel intensities · Transform image to make

Giger, Christine

69

Feature extraction Feature extraction  

E-print Network

(hyperspectral sensors) Meteosat thermal IR channel hyperspectral "image cube" #12;Raw intensities ! � ProsFeature extraction #12;Feature extraction ! � Image interpretation: extract information from images � but the desired information may not be explicit in the raw observed pixel intensities � Transform image to make

Giger, Christine

70

Comprehensive analysis of commercial willow bark extracts by new technology platform: combined use of metabolomics, high-performance liquid chromatography-solid-phase extraction-nuclear magnetic resonance spectroscopy and high-resolution radical scavenging assay.  

PubMed

Here, proof-of-concept of a new analytical platform used for the comprehensive analysis of a small set of commercial willow bark products is presented, and compared with a traditional standardization solely based on analysis of salicin and salicin derivatives. The platform combines principal component analysis (PCA) of two chemical fingerprints, i.e., HPLC and (1)H NMR data, and a pharmacological fingerprint, i.e., high-resolution 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) radical cation (ABTS(+)) reduction profile, with targeted identification of constituents of interest by hyphenated HPLC-solid-phase extraction-tube transfer NMR, i.e., HPLC-SPE-ttNMR. Score plots from PCA of HPLC and (1)H NMR fingerprints showed the same distinct grouping of preparations formulated as capsules of Salix alba bark and separation of S. alba cortex. Loading plots revealed this to be due to high amount of salicin in capsules and ampelopsin, taxifolin, 7-O-methyltaxifolin-3'-O-glucoside, and 7-O-methyltaxifolin in S. alba cortex, respectively. PCA of high-resolution radical scavenging profiles revealed clear separation of preparations along principal component 1 due to the major radical scavengers (+)-catechin and ampelopsin. The new analytical platform allowed identification of 16 compounds in commercial willow bark extracts, and identification of ampelopsin, taxifolin, 7-O-methyltaxifolin-3'-O-glucoside, and 7-O-methyltaxifolin in S. alba bark extract is reported for the first time. The detection of the novel compound, ethyl 1-hydroxy-6-oxocyclohex-2-enecarboxylate, is also described. PMID:23021634

Agnolet, Sara; Wiese, Stefanie; Verpoorte, Robert; Staerk, Dan

2012-11-01

71

Resonance Parameter Measurements and Analysis of Gadolinium  

E-print Network

Resonance Parameter Measurements and Analysis of Gadolinium G Leinweber, DP Barry, MJ Trbovich, JA-matrix Bayesian code SAMMY was used to extract resonance parameters. The results of the thermal region analysis are significant. Resonance parameters for the low energy doublet, at 0.025 and 0.032 eV, are presented

Danon, Yaron

72

Alkaloid analysis by high-performance liquid chromatography-solid phase extraction-nuclear magnetic resonance: new strategies going beyond the standard.  

PubMed

The hyphenated technique HPLC-SPE-NMR is an important tool for rapid dereplication of complex mixtures of in particular small molecules and has been successfully employed in natural product research. However, positively charged alkaloids at low pH are often poorly trapped on the generally used SPE cartridge limiting the general application of the procedure. In this work, two new approaches for efficient SPE trapping of alkaloids and elution efficiencies were evaluated using 24 model alkaloids. Use of a 0.1 M NaOH solution as the post-column dilution greatly enhanced trapping of alkaloids on the commonly used cartridge containing divinylbenzene polymer (GP resin). This procedure, however, was unsuitable for trapping phenolic alkaloids. Severe line broadening and immiscibility with water made chloroform-d(1) unsuited as eluent. None of these problems occurred when methanol-d(4) was used as eluent. Previously, mixed mode cation exchange sorbents have not been used in HPLC-SPE-NMR analysis of natural products. In contrast to GP resin this material showed good retention and elution characteristics for retention and elution of alkaloids. As well the use of methanol-d(4) containing 1% aqueous NaOD (40%) as methanol-d(4) containing 5% aqueous NH(4)OH (30%) as eluents were successful, even though elution of alkaloids with pK(a) of the corresponding acid above 10 proved difficult. Alkaloid extracts of Huperzia selago containing complex aliphatic alkaloids and Triclisia patens containing bisbenzylisoquinoline alkaloids were used for validation of the protocols for analysis of a diverse collection of alkaloids. Mixed mode cation exchange sorbent was efficient for trapping and elution of both types of alkaloids as evidenced by acquisition of 2D NMR data for all trapped compounds. In contrast, GP resin proved only viable for all the H. selago alkaloids whereas trapping and elution of bisbenzylisoquinoline alkaloids were dubious. PMID:23195707

Johansen, Kenneth T; Ebild, Sarah J; Christensen, S Brøgger; Godejohann, Markus; Jaroszewski, Jerzy W

2012-12-28

73

Analysis of sesquiterpene lactones, lignans, and flavonoids in wormwood (Artemisia absinthium L.) using high-performance liquid chromatography (HPLC)-mass spectrometry, reversed phase HPLC, and HPLC-solid phase extraction-nuclear magnetic resonance.  

PubMed

Today, the medicinal use of wormwood (Artemisia absinthium) is enjoying a resurgence of popularity. This study presents a specific and validated high-performance liquid chromatography (HPLC)-diode array detection method for the simultaneous determination and quantification of bioactive compounds in wormwood and commercial preparations thereof. Five sesquiterpene lactones, two lignans, and a polymethoxylated flavonoid were baseline separated on RP-18 material, using a solvent gradient consisting of 0.085% (v/v) o-phosphoric acid and acetonitrile. The flow rate was 1.0 mL/min, and chromatograms were recorded at 205 nm. The stability of absinthin was tested exposing samples to light, moisture, and different temperatures. Methanolic and aqueous solutions of absinthin were found to be stable for up to 6 months. This was also the case when the solid compound was kept in the refrigerator at -35 °C. In contrast, the colorless needles, when stored at room temperature, turned yellow. Three degradation compounds (anabsin, anabsinthin, and the new dimer 3'-hydroxyanabsinthin) were identified by HPLC-mass spectrometry and HPLC-solid-phase extraction-nuclear magnetic resonance and quantified by the established HPLC method. PMID:20886883

Aberham, Anita; Cicek, Serhat Sezai; Schneider, Peter; Stuppner, Hermann

2010-10-27

74

Damping of nanomechanical resonators.  

PubMed

We study the transverse oscillatory modes of nanomechanical silicon nitride strings under high tensile stress as a function of geometry and mode index m?9. Reproducing all observed resonance frequencies with classical elastic theory we extract the relevant elastic constants. Based on the oscillatory local strain we successfully predict the observed mode-dependent damping with a single frequency-independent fit parameter. Our model clarifies the role of tensile stress on damping and hints at the underlying microscopic mechanisms. PMID:20867737

Unterreithmeier, Quirin P; Faust, Thomas; Kotthaus, Jörg P

2010-07-01

75

Resonance scraping  

SciTech Connect

Protons lost in a ring leave at a few preferred locations, determined by some non-linear property of the dipoles. This paper suggests taking control of lost protons by beating the magnets at their own game - by means of a designed resonance used as a beam scraper. It is a study of suitable resonances, including estimates of the required multipole element strengths. The appropriate resonances are two-dimensional. A large number of figures is included.

Collins, T.

1986-06-01

76

Dielectric resonators  

Microsoft Academic Search

Microwave passive and active devices containing dielectric resonators and the design procedures used to characterize these components are reviewed. The emphasis has been on low noise, small size, low cost and high temperature stability. Both filter and oscillator applications are described. The applications of dielectric resonators in the millimeter-wave frequency band are also discussed

P. Guillon

1988-01-01

77

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. PMID:25028568

Martinez-Serra, Jordi; Robles, Juan; Nicolàs, Antoni; Gutierrez, Antonio; Ros, Teresa; Amat, Juan Carlos; Alemany, Regina; Vögler, Oliver; Abelló, Aina; Noguera, Aina; Besalduch, Joan

2014-01-01

78

Two-resonator circuit QED: Dissipative Theory  

E-print Network

We present a theoretical treatment for the dissipative two-resonator circuit quantum electrodynamics setup referred to as quantum switch. There, switchable coupling between two superconducting resonators is mediated by a superconducting qubit operating in the dispersive regime, where the qubit transition frequency is far detuned from those of the resonators. We derive an effective Hamiltonian for the quantum switch beyond the rotating wave approximation and study the dissipative dynamics within a Bloch-Redfield quantum master equation approach. We derive analytically how the qubit affects the quantum switch even if the qubit has no dynamics, and we estimate the strength of this influence. The analytical results are corroborated by numerical calculations, where coherent oscillations between the resonators, the decay of coherent and Fock states, and the decay of resonator-resonator entanglement are studied. Finally, we suggest an experimental protocol for extracting the damping constants of qubit and resonators by measuring the quadratures of the resonator fields.

Georg M. Reuther; David Zueco; Frank Deppe; Elisabeth Hoffmann; Edwin P. Menzel; Thomas Weißl; Matteo Mariantoni; Sigmund Kohler; Achim Marx; Enrique Solano; Rudolf Gross; Peter Hänggi

2009-11-13

79

Acoustic Resonators  

NASA Astrophysics Data System (ADS)

Recently my collection of historical physics teaching apparatus was given a group of 19th-century tuning forks on resonant boxes. Figure 1 shows the smallest fork sitting on the largest one. The large tuning fork oscillates at 128 Hz and has a resonator that is 57.9 cm long. The small fork has a frequency 10 times higher, but its resonator has a length of 11.0 cm instead of the 5.8 cm that simple scaling would suggest. How is this possible?

Greenslade, Thomas B.

2012-11-01

80

Magnetic Resonance  

Cancer.gov

Focus Group on Magnetic Resonance Spectroscopy (MRS) in Clinical Oncology(April 1999) To explore the technical requirements for MRS and the application of hydrogen and multinuclear spectroscopy for tumor response to therapy.

81

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

82

Wireless interrogation techniques for sensors utilizing inductively coupled resonance circuits  

Microsoft Academic Search

The methods needed to interrogate passive resonance sensors are studied. A portable impedance measurement unit and the methods to extract a coupling coefficient compensated resonance frequency are presented. The interrogation methods are demonstrated with ECG and pressure measurements. The results show that the quality of the ECG signal measured with a flexible textile coil is sufficient to extract the heart

Timo Salpavaara; Jarmo Verho; Pekka Kumpulainen; Jukka Lekkala

2010-01-01

83

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

84

Resonance conditions  

E-print Network

Non-linear parametric resonances occur frequently in nature. Here we summarize how they can be studied by means of perturbative methods. We show in particular how resonances can affect the motion of a test particle orbiting in the vicinity of a compact object. These mathematical toy-models find application in explaining the structure of the observed kHz Quasi-Periodic Oscillations: we discuss which aspects of the reality naturally enter in the theory, and which one still remain a puzzle.

P. Rebusco

2005-10-14

85

Building Resonance  

NSDL National Science Digital Library

This demonstration of how buildings respond to seismic shaking uses cardboard and stiff paper (such as postcards or computer cards). The effects of building resonance can be found by experimenting with taller and shorter buildings, and varying the frequency of shaking.

Barker, Jeffrey

86

Stochastic resonance  

Microsoft Academic Search

Over the last two decades, stochastic resonance has continuously attracted considerable attention. The term is given to a phenomenon that is manifest in nonlinear systems whereby generally feeble input information (such as a weak signal) can be be amplified and optimized by the assistance of noise. The effect requires three basic ingredients: (i) an energetic activation barrier or, more generally,

Luca Gammaitoni; Peter Hänggi; Peter Jung; Fabio Marchesoni

1998-01-01

87

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

88

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

89

Electroexcitation of nucleon resonances  

NASA Astrophysics Data System (ADS)

We review recent progress in the investigation of the electroexcitation of nucleon resonances, both in experiment and in theory. We describe current experimental facilities, the experiments performed on ? and ? electroproduction off protons, and theoretical approaches used for the extraction of resonance contributions from the experimental data. The status of 2?, K?, and K? electroproduction is also presented. The most accurate results have been obtained for the electroexcitation amplitudes of the four lowest excited states, which have been measured in a range of Q2 up to 8 and 4.5 GeV 2 for ?(1232)P33, N(1535)S11 and N(1440)P11, N(1520)D13, respectively. These results have been confronted with calculations based on lattice QCD, large- Nc relations, perturbative QCD (pQCD), and QCD-inspired models. The amplitudes for the ?(1232) indicate large pion-cloud contributions at low Q2 and do not show any sign of approaching the pQCD regime for Q2<7 GeV. Measured for the first time, the electroexcitation amplitudes of the Roper resonance, N(1440)P11, provide strong evidence for this state as a predominantly radial excitation of a three-quark (3 q) ground state, with additional non-3-quark contributions needed to describe the low Q2 behavior of the amplitudes. The longitudinal transition amplitude for the N(1535)S11 was determined and has become a challenge for quark models. Explanations may require large meson-cloud contributions or alternative representations of this state. The N(1520)D13 clearly shows the rapid changeover from helicity-3/2 dominance at the real photon point to helicity-1/2 dominance at Q2>0.5 GeV, confirming a long-standing prediction of the constituent quark model. The interpretation of the moments of resonance transition form factors in terms of transition transverse charge distributions in infinite momentum frame is presented.

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

2012-01-01

90

If It's Resonance, What is Resonating?  

ERIC Educational Resources Information Center

The phenomenon under the name "resonance," which, is based on the mathematical analogy between mechanical resonance and the behavior of wave functions in quantum mechanical exchange phenomena was described. The resonating system does not have a structure intermediate between those involved in the resonance, but instead a structure which is further…

Kerber, Robert C.

2006-01-01

91

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.

92

Microwave energy storage in resonant cavities  

SciTech Connect

One method of generating short, high-power microwave pulses is to store rf energy in a resonant cavity over a relatively long fill time and extract is rapidly. A power gain roughly equal to the ratio of fill time to extraction time can be obtained. During the filling of a resonant cavity some of the energy is lost in heating the cavity walls, and some will generally be reflected at the input coupling of the cavity. In this paper we discuss the time dependence of the stored energy and related quantities and the way in which it depends on the coupling of the source to the cavity.

Alvarez, R.A.

1983-02-01

93

Stochastic Resonance  

E-print Network

Stochastic resonance (SR) - a counter-intuitive phenomenon in which the signal due to a weak periodic force in a nonlinear system can be {\\it enhanced} by the addition of external noise - is reviewed. A theoretical approach based on linear response theory (LRT) is described. It is pointed out that, although the LRT theory of SR is by definition restricted to the small signal limit, it possesses substantial advantages in terms of simplicity, generality and predictive power. The application of LRT to overdamped motion in a bistable potential, the most commonly studied form of SR, is outlined. Two new forms of SR, predicted on the basis of LRT and subsequently observed in analogue electronic experiments, are described.

M. I. Dykman; D. G. Luchinsky; R. Mannella; P. V. E. McClintock; S. M. Soskin; N. D. Stein; N. G. Stocks

1993-07-17

94

Compressional-Mode Giant Resonances in Deformed Nuclei  

NASA Astrophysics Data System (ADS)

Background-free inelastic scattering spectra have been obtained for the Sm isotopes with 386 MeV ? particles at forward angles (including 0°) to investigate the effect of deformation on the compressional-mode giant resonances. The strength distributions for the isoscalar giant resonances (L ? 3) have been extracted for 144Sm, 148Sm, 150Sm, 152Sm, 154Sm. We have observed that the effects of deformation are different for the low- and high-excitation-energy components of the isoscalar giant dipole resonance in 154Sm. Evidence for the theoretically predicted coupling between the isoscalar dipole resonance and the high-energy octupole resonance is reported.

Itoh, M.; Fujimura, M.; Fujiwara, M.; Hara, K.; Yoshida, H. P.; Sakaguchi, H.; Uchida, M.; Ishikawa, T.; Kawabata, T.; Murakami, T.; Takeda, H.; Taki, T.; Terashima, S.; Tsukahara, N.; Yasuda, Y.; Yosoi, Y.; Garg, U.; Hedden, M.; Kharraja, B.; Koss, M.; Nayak, B. K.; Zhu, S.; Akimune, H.; Harakeh, M. N.; Volkerts, M.

2003-04-01

95

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

96

Detection of kestoses and kestose-related oligosaccharides in extracts of Festuca arundinacea, Dactylis glomerate L. , and Asparagus officinalis L. root cultures and invertase by sup 13 C and sup 1 H nuclear magnetic resonance spectroscopy  

SciTech Connect

Previous studies show that {sup 13}C nuclear magnetic resonance spectroscopy can be used to detect and identify mixtures of 1-kestose and neokestose after conversion to the acetate derivatives. In this study, unequivocal assignments are made for the anomeric carbon and proton signals for the above two trisaccharide acetates as well as for 6-kestose hendecaacetate and for nystose tetradecaacetate (a 1-kestose-derived tetrasaccharide). A number of oligosaccharide fractions were isolated from several plant species, converted to the acetates, and nuclear magnetic resonance spectra obtained. Using the above reference data, the following information was obtained. The trisaccharide fraction from Dactylis gomerata L. stem tissue and Asparagus officinalis L. roots contain both 1-kestose and neokestose, and the tetrasaccharide fractions contain three components, one of which is nystose. Penta- and hexasaccharide acetates were also isolated from A. officinalis L. roots and were found to contain, respectively, four and at least five components. All components of both of the above species appear to contain a kestose residue and to be produced by the sequential addition of fructofuranosyl units to these. The trisaccharide fraction from Festuca arundinacea is complex, and contains at least five different components, two of which appear to be 1-kestose and neokestose.

Forsythe, K.L.; Feather, M.S.; Gracz, H.; Wong, T.C. (Univ. of Missouri, Columbia (USA))

1990-04-01

97

Resonant frequency band estimation using adaptive wavelet decomposition level selection  

Microsoft Academic Search

The vibrations induced by machine faults help in diagnosis and prognosis of the machine. It is crucial for the fault diagnostic system to extract resonant frequency band which carries useful information about the defect frequencies and contains maximum signal to noise ratio. The spectral orientation of the resonant frequency band varies with the variation in machine dynamics. The existing techniques

M. F. Yaqub; I. Gondal; J. Kamruzzaman

2011-01-01

98

Extractant composition  

DOEpatents

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. The extracting solution consists of a 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-benzoyl-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, Barbara F. (Los Alamos, NM); Jarvinen, Gordon D. (Los Alamos, NM); Ryan, Robert R. (Los Alamos, NM)

1990-01-01

99

Stochastic resonance  

NASA Astrophysics Data System (ADS)

We are taught by conventional wisdom that the transmission and detection of signals is hindered by noise. However, during the last two decades, the paradigm of stochastic resonance (SR) proved this assertion wrong: indeed, addition of the appropriate amount of noise can boost a signal and hence facilitate its detection in a noisy environment. Due to its simplicity and robustness, SR has been implemented by mother nature on almost every scale, thus attracting interdisciplinary interest from physicists, geologists, engineers, biologists and medical doctors, who nowadays use it as an instrument for their specific purposes. At the present time, there exist a lot of diversified models of SR. Taking into account the progress achieved in both theoretical understanding and practical application of this phenomenon, we put the focus of the present review not on discussing in depth technical details of different models and approaches but rather on presenting a general and clear physical picture of SR on a pedagogical level. Particular emphasis will be given to the implementation of SR in generic quantum systems—an issue that has received limited attention in earlier review papers on the topic. The major part of our presentation relies on the two-state model of SR (or on simple variants thereof), which is general enough to exhibit the main features of SR and, in fact, covers many (if not most) of the examples of SR published so far. In order to highlight the diversity of the two-state model, we shall discuss several examples from such different fields as condensed matter, nonlinear and quantum optics and biophysics. Finally, we also discuss some situations that go beyond the generic SR scenario but are still characterized by a constructive role of noise.

Wellens, Thomas; Shatokhin, Vyacheslav; Buchleitner, Andreas

2004-01-01

100

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

101

Resonance production in heavy-ion collisions at STAR  

E-print Network

Hadronic resonances are sensitive to the properties of a hot and dense medium created in a heavy ion collisions. During the hadronic phase, after hadronization of quark and gluons into hadrons, resonances are useful to determine the lifetime between chemical and thermal freeze-out, under the assumption that the re-scattering of the decay particles and the probability of regeneration of resonances from hadrons depends on the system properties and the resonance lifetime. The system size and energy dependence of resonance spectra and yields will be shown and discussed in the context of the lifetime and size of the hadronic phase. Elliptic flow measurement will extend the sensitivity of resonance yields to the partonic state through additional information on constituent quark scaling. We also explore a possible new technique to extract signals from the early, potentially chirally symmetric, stage through the selection of resonances from jets.

Christina Markert; for the STAR Collaboration

2007-12-11

102

Determination of the Delta resonance width from lattice QCD  

E-print Network

A method suitable for extracting resonance parameters of unstable baryons in lattice QCD is examined. The method is applied to the strong decay of the Delta to a pion-nucleon state, extracting the pi-N - Delta coupling constant and Delta decay width.

C. Alexandrou; J. W. Negele; M. Petschlies

2014-01-15

103

Resonance Parameters and Uncertainties Derived from Epithermal Neutron Capture and Transmission Measurements of Natural Molybdenum  

E-print Network

Resonance Parameters and Uncertainties Derived from Epithermal Neutron Capture and Transmission capture and transmission measurements were performed by the time-of-flight technique. Resonance parameters were extracted from the data using the multilevel R-matrix Bayesian code SAMMY. A table of resonance

Danon, Yaron

104

DNA Extraction  

NSDL National Science Digital Library

Teachers' Domain presents this interactive, adapted from the University of Nebraska's Plant and Soil Science eLibrary, with reading material and animations to help students learn the basics of DNA extraction. The lesson is divided into and introduction and the four processes involved: cell lysis, dismantling the cell membrane, removing unwanted cell parts, and precipitating the DNA. On the site, visitors will also find a supplemental background essay, discussion questions, and standards alignment from Teachers' Domain.

2010-10-07

105

Capacitive microbeam resonator design  

NASA Astrophysics Data System (ADS)

Resonant clamped-clamped microbeams sealed in a hard vacuum cavity are classified as transducers, which can measure physical variables by converting them into axial strain using an appropriate silicon microstructure. These devices can be constructed, using surface micromachining technology, on a single-crystal silicon substrate. They have fundamental resonant frequencies with high sensitivity to strain. Such devices use resonant frequency changes by variables such as pressure, temperature, force, and acceleration to measure these quantities. Electrostatically driven and sensed microbeam resonators may be used for sensor applications. In order to design such microbeam resonators it is useful to use electrical network theory. This requires that the mechanical parameters for the resonator are converted to electrical equivalents. For electrostatically driven and sensed microbeam resonators the drive voltage must contain a dc bias and a small amplitude sinusoid in order to drive the resonators at the resonant frequency. The effects of these dc biases and parasitics on the resonant frequency and the quality factor are clarified here with theoretical calculations using the electrical equivalents of electrostatic microbeam resonators and experimental results. As a result the dc bias and parasitics are dominant factors in determining the performance of capacitive microbeam resonators, especially effecting the resonant frequency and quality factor. The maximum vibration amplitude requirements for pure sinusoidal operation with low power dissipation in the capacitive microbeam resonator have also been identified.

Ahn, Yongchul; Guckel, Henry; Zook, J. David

2001-01-01

106

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

2014-05-30

107

Coupled unstable resonators  

NASA Astrophysics Data System (ADS)

Coupling of unstable resonators in circulant arrays is considered, in which the array is invariant with respect to the interchange of any pair of resonators. A proof-of-concept experiment performed with six series coupled CO(2) lasers with confocal unstable resonators is reported. Adjoint coupling was used with two symmetrically placed coupling apertures in each resonator output. The results of measurements of the locking range, supermode content, and beam quality for standing wave and ring resonator arrays are presented and interpreted using simplified models. It is pointed out that adjoint coupled unstable resonators provide a modular scaling configuration with modest phase-locking length control requirements.

Palma, G. E.; Benda, J. A.; Townsend, S. S.; Cunningham, P. R.; Forgham, J.

1990-06-01

108

Resonances in barred galaxies  

NASA Astrophysics Data System (ADS)

The inner parts of many spiral galaxies are dominated by bars. These are strong non-axisymmetric features which significantly affect orbits of stars and dark matter particles. One of the main effects is the dynamical resonances between galactic material and the bar. We detect and characterize these resonances in N-body models of barred galaxies by measuring angular and radial frequencies of individual orbits. We found narrow peaks in the distribution of orbital frequencies with each peak corresponding to a specific resonance. We found five different resonances in the stellar disc and two in the dark matter. The corotation resonance (CR) and the inner and outer Lindblad resonances are the most populated. The spatial distributions of particles near resonances are wide. For example, the inner Lindblad resonance is not localized at a given radius. Particles near this resonance are mainly distributed along the bar and span a wide range of radii. On the other hand, particles near the CR are distributed in two broad areas around the two stable Lagrange points. The distribution resembles a wide ring at the corotation radius. Resonances capture disc and halo material in near-resonant orbits. Our analysis of orbits in both N-body simulations and simple analytical models indicates that resonances tend to prevent the dynamical evolution of this trapped material. Only if the bar evolves as a whole, resonances drift through the phase space. In this case particles anchored near resonant orbits track the resonance shift and evolve. The criteria to ensure a correct resonant behaviour discussed by Weinberg and Katz can be achieved with few millions particles because the regions of trapped orbits near resonances are large and evolving.

Ceverino, D.; Klypin, A.

2007-08-01

109

RF excited laser with internally folded resonator  

SciTech Connect

This patent describes a transversely RF excited gas laser with an internally folded resonator. The transversely RF excited gas laser comprising: an elongated chamber of cross- sectional dimensions suitable for confining a laser gas discharge; a plurality of reflectors which form a stable folded laser resonator cavity of a compact geometry in order to efficiently extract laser power from the laser resonator cavity wherein there are at least two of the plurality of reflectors and at least one of the plurality of reflectors is concave; a laser gas which is disposed in the folded resonator cavity which reflect and guide light energy from the laser gas discharge within the elongated chamber; a pair of electrodes are transversely disposed on the elongated chamber and excite the laser gas; a pair of cooling electrodes are transversely disposed on the elongated chamber and electrically coupled to ground; and impedance- matching means for applying RF power to the pair of electrodes. The impedance matching means including three inductors with a center-tapped coil being adjusted so that the voltage potential at the center of the laser discharge between the pair of cooling electrodes is a virtual ground thereby preventing RF current from passing through the pair of grounded cooling electrodes in order to efficiently extract laser power from the laser resonator cavity.

Sutter, L.V.; Cameron, H.A.; Davison, M.R.

1990-01-02

110

High-Resolution ?-Amylase Assay Combined with High-Performance Liquid Chromatography-Solid-Phase Extraction-Nuclear Magnetic Resonance Spectroscopy for Expedited Identification of ?-Amylase Inhibitors: Proof of Concept and ?-Amylase Inhibitor in Cinnamon.  

PubMed

Type 2 diabetes affects millions of people worldwide, and new improved drugs or functional foods containing selective ?-amylase inhibitors are needed for improved management of blood glucose. In this article the development of a microplate-based high-resolution ?-amylase inhibition assay with direct photometric measurement of ?-amylase activity is described. The inhibition assay is based on porcine pancreatic ?-amylase with 2-chloro-4-nitrophenyl-?-d-maltotriose as substrate, which this gives a stable, sensitive, and cheap inhibition assay as requested for high-resolution purposes. In combination with HPLC-HRMS-SPE-NMR, this provides an analytical platform that allows simultaneous chemical and biological profiling of ?-amylase inhibitors in plant extracts. Proof-of-concept with an artificial mixture of six compounds-of which three are known ?-amylase inhibitors-showed that the high-resolution ?-amylase inhibition profiles allowed detection of sub-microgram amounts of the ?-amylase inhibitors. Furthermore, the high-resolution ?-amylase inhibition assay/HPLC-HRMS-SPE-NMR platform allowed identification of cinnamaldehyde as the ?-amylase inhibitor in cinnamon (Cinnamomum verum Presl.). PMID:25368916

Okutan, Leyla; Kongstad, Kenneth T; Jäger, Anna K; Staerk, Dan

2014-11-26

111

Nanomechanical resonance detector  

DOEpatents

An embodiment of a nanomechanical frequency detector includes a support structure and a plurality of elongated nanostructures coupled to the support structure. Each of the elongated nanostructures has a particular resonant frequency. The plurality of elongated nanostructures has a range of resonant frequencies. An embodiment of a method of identifying an object includes introducing the object to the nanomechanical resonance detector. A resonant response by at least one of the elongated nanostructures of the nanomechanical resonance detector indicates a vibrational mode of the object. An embodiment of a method of identifying a molecular species of the present invention includes introducing the molecular species to the nanomechanical resonance detector. A resonant response by at least one of the elongated nanostructures of the nanomechanical resonance detector indicates a vibrational mode of the molecular species.

Grossman, Jeffrey C; Zettl, Alexander K

2013-10-29

112

Magnetic resonance angiography  

MedlinePLUS

MRA; Angiography - magnetic resonance ... Kwong RY. Cardiovascular Magnetic Resonance Imaging. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine . 9th ...

113

Photoacoustic resonance spectroscopy for biological tissue characterization  

NASA Astrophysics Data System (ADS)

By "listening to photons," photoacoustics allows the probing of chromosomes in depth beyond the optical diffusion limit. Here we report the photoacoustic resonance effect induced by multiburst modulated laser illumination, which is theoretically modeled as a damped mass-string oscillator and a resistor-inductor-capacitor (RLC) circuit. Through sweeping the frequency of multiburst modulated laser, the photoacoustic resonance effect is observed experimentally on phantoms and porcine tissues. Experimental results demonstrate different spectra for each phantom and tissue sample to show significant potential for spectroscopic analysis, fusing optical absorption and mechanical vibration properties. Unique RLC circuit parameters are extracted to quantitatively characterize phantom and biological tissues.

Gao, Fei; Feng, Xiaohua; Zheng, Yuanjin; Ohl, Claus-Dieter

2014-06-01

114

Photonic microdisk resonators in aluminum nitride  

NASA Astrophysics Data System (ADS)

We demonstrate integrated photonic microdisk resonators in sputtered c-axis oriented aluminum nitride (AlN) films. A 400 nm thick layer of AlN was patterned in a single lithography step with silicon dioxide used for the top and bottom cladding layers. AlN disks with a radius of 20 ?m at various spacings to an 850 nm wide waveguide were tested. A loaded quality factor of 28 350 is shown in these microdisks, with an extracted peak shift over power ratio of 0.0495 pm/?W. The demonstration of photonic resonators in a piezoelectric material can lead to novel optomechanical functionalities.

Ghosh, Siddhartha; Piazza, Gianluca

2013-01-01

115

Mechanical Stochastic Resonance  

NASA Astrophysics Data System (ADS)

Noise and nonlinearity can produce a stochastic resonance that maximizes a system's output signal-to-noise ratio. Stochastic resonance has been observed in electronic, chemical, optical, magnetic, and biological systems. Here, we report stochastic resonance in a simple mechanical system consisting of a bistable pendulum driven by a harmonic oscillator and the broad-band noise of a flapping flag.

Wainwright, Elliot; Lindner, John

2013-03-01

116

Nuclear Magnetic Resonance  

NASA Astrophysics Data System (ADS)

Author's preface; 1. Introduction; 2. Basic theory; 3. Experimental methods; 4. Measurement of nuclear properties and general physical applications; 5. Nuclear magnetic resonance in liquids and gases; 6. Nuclear magnetic resonance in non-metallic solids; 7. Nuclear magnetic resonance in metals; 8. Quadrupole effects; Appendices 1-6; Glossary of symbols; Bibliography and author index; Subject index.

Andrew, E. R.

2009-06-01

117

ELECTRON PARAMAGNETIC RESONANCE SPECTROSCOPY  

E-print Network

CHAPTER 3 ELECTRON PARAMAGNETIC RESONANCE SPECTROSCOPY 1 Sergei A. Dikanov and 2 Antony R. Crofts 1 for the investigation of unpaired electron spins. Two terms are used in the literature: electron paramagnetic resonance (EPR) and electron spin resonance (ESR). We will use the first term in this chapter. During the sixty

Crofts, Antony R.

118

Stochastic resonance of quantum discord  

E-print Network

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 ...

Lee, Chee Kong

119

Resonant and non-resonant magnetic scattering  

SciTech Connect

The tunability and the polarization of synchrotron radiation open upon new possibilities for the study of magnetism. Studies on magnetic materials performed at the National Synchrotron Light Source are reviewed, and thy fall into four areas: structure, evolution of magnetic order, separation of L and S, and resonance effects. In the vicinity of atomic absorption edges, the Faraday effect, magnetic circular dichroism, and resonant magnetic scattering are all related resonance effects which measure the spin polarized density of states. The production and analysis of polarized beams are discussed in the context of the study of magnetism with synchrotron radiation.

McWhan, D.B.; Hastings, J.B.; Kao, C.C.; Siddons, D.P.

1991-12-31

120

Resonant and non-resonant magnetic scattering  

SciTech Connect

The tunability and the polarization of synchrotron radiation open upon new possibilities for the study of magnetism. Studies on magnetic materials performed at the National Synchrotron Light Source are reviewed, and thy fall into four areas: structure, evolution of magnetic order, separation of L and S, and resonance effects. In the vicinity of atomic absorption edges, the Faraday effect, magnetic circular dichroism, and resonant magnetic scattering are all related resonance effects which measure the spin polarized density of states. The production and analysis of polarized beams are discussed in the context of the study of magnetism with synchrotron radiation.

McWhan, D.B.; Hastings, J.B.; Kao, C.C.; Siddons, D.P.

1991-01-01

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

Phase-conjugate resonator  

SciTech Connect

By incorporating a phase-conjugating process (Stimulated Brillouin Scattering) with a master oscillator power amplifier laser cavity, a new phase-conjugate resonator (PCR) is obtained. The PCR utilizes flashlamp-pumped dye lasers and a resonator cavity that is formed by a 100% mirror on one end and a Stimulated Brillouin Scattering (SBS) cell on the other end. The SBS cell functions as one of the mirrors of the resonator and causes the entire system to operate as a phase-conjugate resonator. The result is vastly improved (an order of magnitude) beam qualities over conventional resonators for large lamp systems.

Russell, S.D.

1988-11-28

123

Optical Helmholtz resonators  

NASA Astrophysics Data System (ADS)

Helmholtz resonators are widely used acoustic components able to select a single frequency. Here, based on an analogy between acoustics and electromagnetism wave equations, we present an electromagnetic 2D Helmholtz resonator made of a metallic slit-box structure. At the resonance, the light is funneled in the ?/800 apertures, and is subsequently absorbed in the cavity. As in acoustics, there is no higher order of resonance, which is an appealing feature for applications such as photodetection or thermal emission. Eventually, we demonstrate that the slit is of capacitive nature while the box behaves inductively. We derive an analytical formula for the resonance wavelength, which does not rely on wave propagation and therefore does not depend on the permittivity of the material filling the box. Besides, in contrast with half-wavelength resonators, the resonance wavelength can be engineered by both the slit aspect ratio and the box area.

Chevalier, Paul; Bouchon, Patrick; Haïdar, Riad; Pardo, Fabrice

2014-08-01

124

Microfiber and Microcoil Resonators and Resonant Sensors  

NASA Astrophysics Data System (ADS)

The manufacture of tapers from optical fibers provides the possibility to get long, uniform, and robust micrometer- or nanometer-size wires. Optical microfibers are fabricated by adiabatically stretching conventional optical fibers and thus preserve the original optical fiber dimensions at their input/output pigtails, allowing ready splicing to standard fibers. Since microfibers have a size comparable to the wavelength of the light propagating in it, a considerable fraction of power can be located in the evanescent field, outside the microfiber physical boundary. When a microfiber is coiled, the mode propagating in it interferes with itself to give a resonator. In this chapter the latest results on the manufacture of optical microfiber resonators are presented. Optical microfibers can be used to fabricate single-loop and multiple-loop (coil) resonators with extremely high Q factors. High Q resonators can be used for refractometric biosensors and because of their design they provide an exceptionally high sensitivity.

Xu, Fei; Brambilla, Gilberto

125

Pade Theory and Phenomenology of Resonance Poles  

E-print Network

The use of Pade approximants for the description of QCD matrix elements is discussed in this talk. We will see how they prove to be an extremely useful tool, specially in the case of resonant amplitudes. It will allow the inclusion of high-energy Euclidian data to improve the determination of low-energy properties, such as the quadratic vector radius. This does not mean that the rational approximations can be arbitrarily employed for the extraction of any desired hadronic parameter. A discussion about the validity, limitations and possible issues of the Pade analysis is carried on along the paper. Finally, based on the de Montessus de Ballore's theorem, a theoretically safe new procedure for the extraction of the pole mass and width of resonances is proposed here and illustrated with the example of the rho(770).

J. J. Sanz-Cillero

2010-02-18

126

Isoscalar Giant Dipole Resonance and Nuclear Incompressibility  

NASA Astrophysics Data System (ADS)

The isoscalar giant dipole resonance (ISGDR) in 208Pb has been studied via inelastic ?-scattering of 400 MeV at extremely forward angles, including 0°. Energy spectra virtually free from instrumental background have been obtained with a ray-tracing technique, and the ISGDR strength distribution has been extracted using a multipole-decomposition analysis. These results lead to a value for nuclear incompressibility that is consistent for both the isoscalar dipole and monopole modes.

Uchida, M.; Sakaguchi, H.; Itoh, M.; Yosoi, M.; Kawabata, T.; Takeda, H.; Yasuda, Y.; Murakami, T.; Ishikawa, T.; Taki, T.; Tsukahara, N.; Terashima, S.; Garg, U.; Hedden, M.; Kharraja, B.; Koss, M.; Nayak, B. K.; Zhu, S.; Fujiwara, M.; Fujimura, H.; Hara, K.; Obayashi, E.; Yoshida, H. P.; Akimune, H.; Harakeh, M. N.; Volkerts, M.

2003-04-01

127

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

128

Systematics of the bimodal isoscalar giant dipole resonance  

NASA Astrophysics Data System (ADS)

The systematic behavior of the isoscalar giant dipole resonance (ISGDR) in 90Zr , 116Sn , 144Sm , and 208Pb is studied with inelastic ? scattering at E? =386 MeV . Multipole-decomposition analysis is applied to extract the excitation strengths of giant resonances from the (?, ?' ) differential cross sections at ?lab = 0.64° 13.5° . The bimodal structure of the ISGDR is discussed and compared with recent theoretical results from Hartree-Fock+random-phase-approximation calculations.

Uchida, M.; Sakaguchi, H.; Itoh, M.; Yosoi, M.; Kawabata, T.; Yasuda, Y.; Takeda, H.; Murakami, T.; Terashima, S.; Kishi, S.; Garg, U.; Boutachkov, P.; Hedden, M.; Kharraja, B.; Koss, M.; Nayak, B. K.; Zhu, S.; Fujiwara, M.; Fujimura, H.; Yoshida, H. P.; Hara, K.; Akimune, H.; Harakeh, M. N.

2004-05-01

129

Europium resonance parameters from neutron capture and transmission measurements in the energy range 0.01200 eV  

E-print Network

Europium resonance parameters from neutron capture and transmission measurements in the energy Transmission Capture Thermal cross section RPI Resonance parameters a b s t r a c t Europium is a good absorber-segment sodium iodide multiplicity detector. Resonance parameters were extracted from the data using

Danon, Yaron

130

Large mode radius resonators  

NASA Technical Reports Server (NTRS)

Resonator configurations permitting operation with large mode radius while maintaining good transverse mode discrimination are considered. Stable resonators incorporating an intracavity telescope and unstable resonator geometries utilizing an output coupler with a Gaussian reflectivity profile are shown to enable large radius single mode laser operation. Results of heterodyne studies of pulsed CO2 lasers with large (11mm e sup-2 radius) fundamental mode sizes are presented demonstrating minimal frequency sweeping in accordance with the theory of laser-induced medium perturbations.

Harris, Michael R.

1987-01-01

131

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

132

Extraction of carboxylic acids by amine extractants  

Microsoft Academic Search

This work examines the chemistry of solvent extraction by long-chain amines for recovery of carboxylic acids from dilute aqueous solution. Long-chain amines act as complexing agents with the acid, which facilitates distribution of the acid into the organic phase. The complexation is reversible, allowing for recovery of the acid from the organic phase and regeneration of the extractant. Batch extraction

Janet Ayako Tamada; C. J. King

1989-01-01

133

Dynamic Nuclear Spin Resonance in n-GaAs  

NASA Astrophysics Data System (ADS)

The dynamics of optically detected nuclear magnetic resonance is studied in n-GaAs via time-resolved Kerr rotation using an on-chip microcoil for rf field generation. Both optically allowed and optically forbidden NMR are observed with a dynamics controlled by the interplay between dynamic nuclear polarization via hyperfine interaction with optically generated spin-polarized electrons and nuclear spin depolarization due to magnetic resonance absorption. Comparing the characteristic nuclear spin relaxation rate obtained in experiment with master equation simulations, the underlying nuclear spin depolarization mechanism for each resonance is extracted.

Chen, Y. S.; Reuter, D.; Wieck, A. D.; Bacher, G.

2011-10-01

134

Dynamic nuclear spin resonance in n-GaAs.  

PubMed

The dynamics of optically detected nuclear magnetic resonance is studied in n-GaAs via time-resolved Kerr rotation using an on-chip microcoil for rf field generation. Both optically allowed and optically forbidden NMR are observed with a dynamics controlled by the interplay between dynamic nuclear polarization via hyperfine interaction with optically generated spin-polarized electrons and nuclear spin depolarization due to magnetic resonance absorption. Comparing the characteristic nuclear spin relaxation rate obtained in experiment with master equation simulations, the underlying nuclear spin depolarization mechanism for each resonance is extracted. PMID:22107431

Chen, Y S; Reuter, D; Wieck, A D; Bacher, G

2011-10-14

135

Magnetic resonance imaging and spectroscopy  

SciTech Connect

This book contains 17 selections. Some of the chapter titles are: Basic Principles of Magnetic Resonance Imaging;Evaluation of Demyelinating Diseases;Respiratory Gating in Magnetic Resonance Imaging;Magnetic Resonance Imaging of the Abdomen;Contrast Agents in Magnetic Resonance Imaging;and Economic Considerations in Magnetic Resonance Imaging.

Mettler, F.A.; Muroff, L.R.; Kulkarni, M.V.

1986-01-01

136

The effect of deformation in the isoscalar giant dipole resonance  

NASA Astrophysics Data System (ADS)

Background-free inelastic scattering spectra have been obtained for 144,148,150,152,154Sm with 386 MeV ? particles at forward angles (including 0°) to investigate the effect of deformation on the isoscalar giant dipole resonance. The strength distributions for isoscalar giant resonances have been extracted via a multipole decomposition analysis using angular distributions calculated in the framework of the density-dependent single-folding model. The effects of deformation are found to be different for the low- and high-excitation energy components of the isoscalar giant dipole resonance. Evidence has been obtained for the theoretically-predicted mixing between the isoscalar giant dipole resonance and the high energy octupole resonance.

Itoh, M.; Sakaguchi, H.; Uchida, M.; Ishikawa, T.; Kawabata, T.; Murakami, T.; Takeda, H.; Taki, T.; Terashima, S.; Tsukahara, N.; Yasuda, Y.; Yosoi, M.; Garg, U.; Hedden, M.; Kharraja, B.; Koss, M.; Nayak, B. K.; Zhu, S.; Fujimura, H.; Fujiwara, M.; Hara, K.; Yoshida, H. P.; Akimune, H.; Harakeh, M. N.; Volkerts, M.

2004-02-01

137

Understanding motor resonance  

Microsoft Academic Search

The discovery of mirror neurons in monkeys, and the finding of motor activity during action observation in humans are generally regarded to support motor theories of action understanding. These theories take motor resonance to be essential in the understanding of observed actions and the inference of action goals. However, the notions of “resonance,” “action understanding,” and “action goal” appear to

Sebo Uithol; Iris van Rooij; Harold Bekkering; Pim Haselager

2011-01-01

138

Helioseismology The Resonant Sun  

E-print Network

Helioseismology The Resonant Sun Professor Bill Chaplin, School of Physics & Astronomy University Eddington #12;The Unseen Interior ''At first sight it would seem that the deep interior of the sun and stars;Overview What are resonant oscillations of the Sun? How do we observe the oscillations? What can we learn

139

Polaritonic Feshbach resonance  

NASA Astrophysics Data System (ADS)

A Feshbach resonance occurs when the energy of two interacting free particles comes into resonance with a molecular bound state. When approaching this resonance, marked changes in the interaction strength between the particles can arise. Feshbach resonances provide a powerful tool for controlling the interactions in ultracold atomic gases, which can be switched from repulsive to attractive, and have allowed a range of many-body quantum physics effects to be explored. Here we demonstrate a Feshbach resonance based on the polariton spinor interactions in a semiconductor microcavity. By tuning the energy of two polaritons with anti-parallel spins across the biexciton bound state energy, we show an enhancement of attractive interactions and a prompt change to repulsive interactions. A mean-field two-channel model quantitatively reproduces the experimental results. This observation paves the way for a new tool for tuning polariton interactions and to move forward into quantum correlated polariton physics.

Takemura, N.; Trebaol, S.; Wouters, M.; Portella-Oberli, M. T.; Deveaud, B.

2014-07-01

140

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

141

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

142

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

143

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

144

An inductively coupled, doubly tuned resonator for in vivo nuclear magnetic resonance spectroscopy  

NASA Astrophysics Data System (ADS)

We present a coil designed for in vivo 31P and 1H nuclear magnetic resonance spectroscopy which consists of a doubly tuned resonator inductively coupled to separate 1H and 31P feed coils. The advantages of the resonator include the ability to 1H shim over the same volume from which 31P spectra are extracted by using a single sample coil, elimination of coupling problems between separate 1H and 31P coils, ease of design and tuning over conventional double-tuned coils, and reduced match/tune sensitivity to coil loading, which is important in in vivo applications. We have used this coil to collect phosphorus spectra from the in situ heart of the western painted turtle (Chrysemys picta bellii) at 2 T. The total heart volume was less than 1 mL and acquisition time was just under 10 min.

McNichols, Roger J.; Wright, Steven M.; Wasser, Jeremy S.; Coté, Gerard L.

1999-08-01

145

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

146

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

147

Spin resonance strength calculations  

SciTech Connect

In calculating the strengths of depolarizing resonances it may be convenient to reformulate the equations of spin motion in a coordinate system based on the actual trajectory of the particle, as introduced by Kondratenko, rather than the conventional one based on a reference orbit. It is shown that resonance strengths calculated by the conventional and the revised formalisms are identical. Resonances induced by radiofrequency dipoles or solenoids are also treated; with rf dipoles it is essential to consider not only the direct effect of the dipole but also the contribution from oscillations induced by it.

Courant,E.D.

2008-10-06

148

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.

Jensen, Kenneth J; Girit, Caglar O; Mickelson, William E; Zettl, Alexander K; Grossman, Jeffrey C

2013-11-05

149

RF voltage modulation at discrete frequencies with applications to crystal channeling extraction  

SciTech Connect

RF voltage modulation at a finite number of discrete frequencies is described in a Hamiltonian resonance framework. The theory is applied to the problem of parasitic extraction of a fixed target beam from a high energy proton collider, using a bent crystal as a thin ``septum`` within an effective width of about one micron. Three modes of employment of discrete resonances are proposed.First, a single relatively strong static ``drive`` resonance may be used to excite a test proton so that it will penetrate deeply into the channeling crystal. Second, a moderately strong ``feed`` resonance with a ramped modulation tune may be used to adiabatically trap protons near the edge of the beam core, and transport them to the drive resonance. Third, several weak resonances may be overlapped to create a chaotic amplitude band, either to transport protons to the drive resonance, or to provide a ``pulse stretching`` buffer between a feed resonance and the drive resonance. Extraction efficiency is semi- quantitatively described in terms of characteristic ``penetration,`` ``depletion,`` and ``repetition`` times. simulations are used to quantitatively confirm the fundamental results of the theory, and to show that a prototypical extraction scheme using all three modes promises good extraction performance.

Gabella, W.; Rosenzweig, J. [California Univ., Los Angeles, CA (United States). Dept. of Physics; Kick, R. [Illinois Math and Science Academy, Aurora, Illinois (United States); Peggs, S. [Fermi National Accelerator Lab., Batavia, IL (United States)

1992-05-01

150

RF voltage modulation at discrete frequencies with applications to crystal channeling extraction  

SciTech Connect

RF voltage modulation at a finite number of discrete frequencies is described in a Hamiltonian resonance framework. The theory is applied to the problem of parasitic extraction of a fixed target beam from a high energy proton collider, using a bent crystal as a thin septum'' within an effective width of about one micron. Three modes of employment of discrete resonances are proposed.First, a single relatively strong static drive'' resonance may be used to excite a test proton so that it will penetrate deeply into the channeling crystal. Second, a moderately strong feed'' resonance with a ramped modulation tune may be used to adiabatically trap protons near the edge of the beam core, and transport them to the drive resonance. Third, several weak resonances may be overlapped to create a chaotic amplitude band, either to transport protons to the drive resonance, or to provide a pulse stretching'' buffer between a feed resonance and the drive resonance. Extraction efficiency is semi- quantitatively described in terms of characteristic penetration,'' depletion,'' and repetition'' times. simulations are used to quantitatively confirm the fundamental results of the theory, and to show that a prototypical extraction scheme using all three modes promises good extraction performance.

Gabella, W.; Rosenzweig, J. (California Univ., Los Angeles, CA (United States). Dept. of Physics); Kick, R. (Illinois Math and Science Academy, Aurora, Illinois (United States)); Peggs, S. (Fermi National Accelerator Lab., Batavia, IL (United States))

1992-05-01

151

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

152

Chemical oxygen-iodine laser power generation with an off-axis hybrid resonator  

Microsoft Academic Search

A rectangular negative branch off-axis hybrid resonator was coupled to a 10 kW class chemical oxygen-iodine laser. Resonator setup and alignment turned out to be straightforward. The extracted power was 6.6 kW and reached approximately 70% of the power for an optimized stable resonator. The divergence of the emitted laser beam in the unstable direction was lower than two times

Jürgen Handke; Wolfgang O. Schall; Thomas Hall; Frank Duschek; Karin M. Grünewald

2006-01-01

153

Neutral Pion Electroproduction in the Delta Resonance Region  

SciTech Connect

The electroproduction of baryon resonances at high Q2 is examined. Analysis focuses on the Delta(1232) resonance via exclusive pseudoscalar meson production of À0 particles. Differential cross sections are extracted for exclusive À0 electroproduction. In the central invariant mass (W) region the cross sections are used to extract resonant multipole amplitudes. In particular, the ratio of the electric quadrupole to magnetic dipole amplitudes (E2/M1) will be discussed for the Delta(1232) resonance. The transition to pQCD is discussed in terms of E2/M1 and other multipoles. The helicity amplitude A3/2 can be used as a baryon helicity conservation meter in this context and will be discussed. The fast shrinking of the resonant contribution in the Delta region is observed at this high momentum transfer. Apart from the observables related to pQCD scaling, the transition form factor G#23;M is extracted along with the scalar to magnetic dipole ratio C2/M1.

Anthony Villano

2007-11-01

154

Optical diagnostics for a ring resonator free-electron lasers  

SciTech Connect

The optical cavity of the Boeing free-electron laser (FEL) was reconfigured as a semiconfocal ring resonator with two glancing incidence hyperboloid-paraboloid telescopes. The challenge for this experiment was the complexity of the ring resonator compared to the simplicity of a concentric cavity. The ring resonator's nonspherical mirror surfaces, its multiple elements, and the size of the components contributed to the problems of keeping the optical mode of the resonator matched to the electron beam in the wiggler. Several new optical diagnostics were developed to determine when the optical mode in the FEL was spatially and temporally matched to the electron beam through the wiggler. These included measurements of the focus position and Rayleigh range of the ring resonator optics to determine the spatial match of the optical mode through the wiggler, and a measurement of the position of the optical axis for multiple passes around the ring resonator to determined the stability of the resonator alignment. This paper also describes the optical measurements that were necessary to achieve reliable lasing. The techniques for measuring ring resonator Rayleigh range and focus position, multiple pass alignment, cavity length, optical energy per micropulse, peak power, optical extraction, small signal gain, ringdown loss, lasing wavelength, electron bunch pulse width, and energy slew are discussed.

Laucks, M.L.; Dowell, D.H.; Lowrey, A.R. (Boeing Defense and Space Group, Seattle, WA (United States)); Bender, S.C.; Lumpkin, A.H. (Los Alamos National Lab., NM (United States)); Bentz, M.P. (Rocketdyne Div. of Rockwell International, Canoga Park, CA (United States))

1993-02-01

155

Resonant Doppler velocimeter  

NASA Technical Reports Server (NTRS)

Narrow linewidth tunable lasers augur a new kind of laser Doppler velocimetry employing resonant absorption and fluorescence from trace atomic species rather than scattering from particles. This technique may provide better turbulence and small volume information than present velocimetry.

Miles, R. B.

1975-01-01

156

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

157

Electrically detected ferromagnetic resonance  

SciTech Connect

We study the magnetoresistance properties of thin ferromagnetic CrO{sub 2} and Fe{sub 3}O{sub 4} films under microwave irradiation. Both the sheet resistance {rho} and the Hall voltage V{sub Hall} characteristically change when a ferromagnetic resonance (FMR) occurs in the film. The electrically detected ferromagnetic resonance (EDFMR) signals closely match the conventional FMR, measured simultaneously, in both resonance fields and line shapes. The sign and the magnitude of the resonant changes {delta}{rho}/{rho} and {delta}V{sub Hall}/V{sub Hall} can be consistently described in terms of a Joule heating effect. Bolometric EDFMR thus is a powerful tool for the investigation of magnetic anisotropy and magnetoresistive phenomena in ferromagnetic micro- or nanostructures.

Goennenwein, S. T. B.; Schink, S. W.; Brandlmaier, A.; Boger, A.; Opel, M.; Gross, R.; Keizer, R. S.; Klapwijk, T. M.; Gupta, A.; Huebl, H.; Bihler, C.; Brandt, M. S. [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching (Germany); Kavli Institute of NanoScience, Delft University of Technology, 2628 CJ Delft (Netherlands); MINT Center, University of Alabama, Tuscaloosa, Alabama 35487 (United States); Walter Schottky Institut, Technische Universitaet Muenchen, 85748 Garching (Germany)

2007-04-16

158

Resonances Do Not Equilibrate  

NASA Astrophysics Data System (ADS)

We discuss, in qualitative and quantitative fashion, the yields of hadron resonances. We show that these yields, in general, are not in chemical equi- librium. We evaluate the non-equilibrium abundances in a dynamic model implementing the 1+2 leftrightarrow 3 resonance formation reactions. Due to the strength of these reactions, we show the Sigma (1385) enhancement, and the Lambda (1520) suppression explicitly.

Kuznetsova, I.; Letessier, J.; Rafelski, J.

2009-04-01

159

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

160

Nuclear magnetic resonance gyroscope  

SciTech Connect

A nuclear magnetic resonance gyro using two nuclear magnetic resonance gases, preferably xenon 129 and xenon 131, together with two alkaline metal vapors, preferably rubidium, potassium or cesium, one of the two alkaline metal vapors being pumped by light which has the wavelength of that alkaline metal vapor, and the other alkaline vapor being illuminated by light which has the wavelength of that other alkaline vapor.

Grover, B.C.

1984-02-07

161

Ferromagnetic resonance in ?-Co magnetic composites.  

PubMed

We investigate the electromagnetic properties of assemblies of nanoscale ?-cobalt crystals with size range between 5 to 35 nm, embedded in a polystyrene matrix, at microwave (1-12 GHz) frequencies. We investigate the samples by transmission electron microscopy imaging, demonstrating that the particles aggregate and form chains and clusters. By using a broadband coaxial-line method, we extract the magnetic permeability in the frequency range from 1 to 12 GHz, and we study the shift of the ferromagnetic resonance (FMR) with respect to an externally applied magnetic field. We find that the zero-magnetic field ferromagnetic resonant peak shifts towards higher frequencies at finite magnetic fields, and the magnitude of complex permeability is reduced. At fields larger than 2.5 kOe the resonant frequency changes linearly with the applied magnetic field, demonstrating the transition to a state in which the nanoparticles become dynamically decoupled. In this regime, the particles inside clusters can be treated as non-interacting, and the peak position can be predicted from Kittel's FMR theory for non-interacting uniaxial spherical particles combined with the Landau-Lifshitz-Gilbert equation. In contrast, at low magnetic fields this magnetic order breaks down and the resonant frequency in zero magnetic field reaches a saturation value reflecting the interparticle interactions as resulting from aggregation. Our results show that the electromagnetic properties of these composite materials can be tuned by external magnetic fields and by changes in the aggregation structure. PMID:25397945

Chalapat, Khattiya; Timonen, Jaakko V I; Huuppola, Maija; Koponen, Lari; Johans, Christoffer; Ras, Robin H A; Ikkala, Olli; Oksanen, Markku A; Seppälä, Eira; Paraoanu, G S

2014-12-01

162

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

163

Optofluidic ring resonator dye lasers  

Microsoft Academic Search

We overview the recent progress on optofluidic ring resonator (OFRR) dye lasers developed in our research group. The fluidics and laser cavity design can be divided into three categories: capillary optofluidic ring resonator (COFRR), integrated cylindrical optofluidic ring resonator (ICOFRR), and coupled optofluidic ring resonator (CpOFRR). The COFRR dye laser is based on a micro-sized glass capillary with a wall

Yuze Sun; Jonathan D. Suter; Xudong Fan

2010-01-01

164

Resonance decay effects on anisotropy parameters  

SciTech Connect

We present the elliptic flow v{sub 2} of pions produced from resonance decays. The transverse momentum p{sub T} spectra of the parent particles are taken from thermal model fits and their v{sub 2} are fit under the assumption that they follow a number-of-constituent-quark (NCQ) scaling law expected from quark-coalescence models. The v{sub 2} of pions from resonance particle decays is found to be similar to the measured pion v{sub 2}. We also propose the measurement of electron v{sub 2} as a means to extract open-charm v{sub 2} and investigate whether a thermalized system of quasi-free quarks and gluons (a quark-gluon plasma) is created in collisions of Au nuclei at RHIC.

Dong, Xin; Esumi, S.; Sorensen, P.; Xu, Nu; Xu, Z.

2004-03-11

165

Hunting resonance poles with Rational Approximants  

E-print Network

Based on the mathematically well defined Pad\\'e Theory, a theoretically safe new procedure for the extraction of the pole mass and width of resonances is proposed. In particular, thanks to the Montessus de Ballore's theorem we are able to unfold the Second Riemann sheet of an amplitude to search the position of the resonant 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. This letter partially covers the material presented by the author at the 15th International QCD Conference: QCD 10 (25th anniversary), Montpellier, France, 28 Jun - 3 Jul 2010 and at the Quark Confinement and the Hadron Spectrum IX, 30 August - 3 September 2010, Madrid, Spain.

Pere Masjuan

2010-12-13

166

Characterization of resonances using finite size effects  

E-print Network

We develop methods to extract resonance widths from finite volume spectra of 1+1 dimensional quantum field theories. Our two methods are based on Luscher's description of finite size corrections, and are dubbed the Breit-Wigner and the improved "mini-Hamiltonian" method, respectively. We establish a consistent framework for the finite volume description of sufficiently narrow resonances that takes into account the finite size corrections and mass shifts properly. Using predictions from form factor perturbation theory, we test the two methods against finite size data from truncated conformal space approach, and find excellent agreement which confirms both the theoretical framework and the numerical validity of the methods. Although our investigation is carried out in 1+1 dimensions, the extension to physical (3+1) space-time dimensions appears straightforward, given sufficiently accurate finite volume spectra.

B. Pozsgay; G. Takacs

2006-04-04

167

ExtractEd from: Transforming higher  

E-print Network

ExtractEd from: Transforming higher educaTion Through Technology-enhanced learning EditEd by t.heacademy.ac.uk/technology isbn 978-1-907207-11-2 © the Higher Education academy december 2009 the Higher Education academy;TranSForming higher educaTion Through TechnoLogy-enhanced Learning 191 a BluePrinT for Transforma

Azzopardi, Leif

168

Extraction of carboxylic acids by amine extractants  

SciTech Connect

This work examines the chemistry of solvent extraction by long-chain amines for recovery of carboxylic acids from dilute aqueous solution. Long-chain amines act as complexing agents with the acid, which facilitates distribution of the acid into the organic phase. The complexation is reversible, allowing for recovery of the acid from the organic phase and regeneration of the extractant. Batch extraction experiments were performed to study the complexation of acetic, lactic, succinic, malonic, fumaric, and maleic acids with Alamine 336, an aliphatic, tertiary amine extractant, dissolved in various diluents. Results were interpreted by a ''chemical'' model, in which stoichiometric ratios of acid and amine molecules are assumed to form complexes in the solvent phase. From fitting of the extraction data, the stoichiometry of complexes formed and the corresponding equilibrium constants were obtained. The results of the model were combined with infrared spectroscopic experiments and results of past studies to analyze the chemical interactions that are responsible for extraction behavior. The information from the equilibrium studies was used to develop guidelines for large-scale staged extraction and regeneration schemes. A novel scheme, in which the diluent composition is shifted between extraction and regeneration, was developed which could achieve both high solute recovery and high product concentration. 169 refs., 57 figs., 15 tabs.

Tamada, Janet Ayako; King, C.J.

1989-01-01

169

Systematic study of L?3 giant resonances in Sm isotopes via multipole decomposition analysis  

NASA Astrophysics Data System (ADS)

Background-free inelastic scattering spectra have been obtained for five Sm isotopes with 386-MeV ? particles at forward angles (including 0° ) to investigate the effect of deformation on the compressional-mode giant resonances. The strength distributions for the L?3 isoscalar giant resonances have been extracted via a multipole decomposition analysis using angular distributions calculated in the framework of the density-dependent single-folding model. We observed a splitting of the giant monopole resonance because of its mixing with the giant quadrupole resonance. For the isoscalar giant dipole resonance, the observed effects of deformation are different for the low- and high-excitation-energy components. Evidence has been obtained for the theoretically predicted mixing between the isoscalar giant dipole resonance and the high energy octupole resonance.

Itoh, M.; Sakaguchi, H.; Uchida, M.; Ishikawa, T.; Kawabata, T.; Murakami, T.; Takeda, H.; Taki, T.; Terashima, S.; Tsukahara, N.; Yasuda, Y.; Yosoi, M.; Garg, U.; Hedden, M.; Kharraja, B.; Koss, M.; Nayak, B. K.; Zhu, S.; Fujimura, H.; Fujiwara, M.; Hara, K.; Yoshida, H. P.; Akimune, H.; Harakeh, M. N.; Volkerts, M.

2003-12-01

170

Split-ball resonator  

E-print Network

We introduce a new concept of split-ball resonator and demonstrate a strong omnidirectional magnetic dipole response for both gold and silver spherical plasmonic nanoparticles with nanometer-scale cuts. Tunability of the magnetic dipole resonance throughout the visible spectral range is demonstrated by a change of the depth and width of the nanoscale cut. We realize this novel concept experimentally by employing the laser-induced transfer method to produce near-perfect spheres and helium ion beam milling to make cuts with the nanometer resolution. Due to high quality of the spherical particle shape, governed by strong surface tension forces during the laser transfer process, and the clean, straight side walls of the cut made by helium ion milling, magnetic resonance is observed at 600 nm in gold and at 565 nm in silver nanoparticles. Structuring arbitrary features on the surface of ideal spherical resonators with nanoscale dimensions provides new ways of engineering hybrid resonant modes and ultra-high near-f...

Kuznetsov, Arseniy I; Fu, Yuan Hsing; Viswanathan, Vignesh; Rahmani, Mohsen; Valuckas, Vytautas; Kivshar, Yuri; Pickard, Daniel S; Lukiyanchuk, Boris

2014-01-01

171

Resonances in Positronium Hydride  

NASA Technical Reports Server (NTRS)

Recently, Ho and his colleagues have calculated the positions and widths of a series of resonances in the Ps+H scattering system, using the complex -rotation method and have compared them with estimates that I made many years ago using a quite different technique. I assumed that the resonance mechanism was the existence in the rearrangement channel [e+ + H-] of an infinite series of perturbed Coulomb bound states. Although these must be broadened and shifted by coupling with the open scattering channel, I expected them to lie very close to the actual resonance positions. To verify this, I did a model calculation for S-waves, including the coupling, and found that the first two resonances were not shifted very far from their unperturbed position. The new, detailed calculation agrees with this result, but when the P-wave was examined it was found, surprisingly, that the lowest resonance indeed moved up in energy by a large amount. With the help of Joseph DiRienzi of the College of Notre Dame of Maryland I am now extending the old calculation to P- and D-waves, in an attempt to understand this unexpected energy shift. Results will be presented at the Workshop.

Drachman, Richard J.; Fisher, Richard R. (Technical Monitor)

2001-01-01

172

Reconfigurable optical routers based on Coupled Resonator Induced Transparency resonances.  

PubMed

The interferometric coupling of pairs of resonators in a resonator sequence generates coupled ring induced transparency (CRIT) resonances. These have quality factors an order of magnitude greater than those of single resonators. We show that it is possible to engineer CRIT resonances in tapered SCISSOR (Side Coupled Integrated Space Sequence of Resonator) to realize fast and efficient reconfigurable optical switches and routers handling several channels while keeping single channel addressing capabilities. Tapered SCISSORs are fabricated in silicon-on-insulator technology. Furthermore, tapered SCISSORs show multiple-channel switching behavior that can be exploited in DWDM applications. PMID:23188351

Mancinelli, M; Bettotti, P; Fedeli, J M; Pavesi, L

2012-10-01

173

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

174

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); Kuokkala, Veli-Tapani (Tampere, FI)

1992-01-01

175

Magnetic Resonance Online Texts  

NSDL National Science Digital Library

This well-organized and very thorough website was developed by the physicist Stanislav Sykora with the aim of providing free online texts, theses, and course materials on the subjects of magnetic resonance (MR), magnetic resonance imaging (MRI), nuclear-magnetic resonance (NMR) and other related topics. The amount of material on the site is impressive. At the top of the page are links to an "MR Blog", as well as to "MR Links" and the "Site Plan & SEARCH". The NMR/MRI Extras section on the right side of the page is particularly useful for visitors interested in all things about MR. Its links to "Events" provides an up-to-date list of symposia, conferences, and meetings, along with links to the events' sites. The "Societies" link offers at least 50 groups about MR, some of which are country-based, and others that are region- or application-based.

Sãâãâ½kora, Stanislav

176

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

177

Proton Resonance Spectroscopy in MAGNESIUM-24  

NASA Astrophysics Data System (ADS)

Excitation functions for proton elastic scattering and proton induced reactions on ('23)Na were measured with the KN Van de Graaff accelerator and associated high resolution system at Triangle Universities Nuclear Laboratory. Differential cross sections for the ('23)Na(p,p(,0)), (p,p(,1)),(p,(alpha)(,0)), and (p,(alpha)(,1)) reactions were obtained for the energy range E(,p) = 1.08 to 4.15 MeV with an overall experimental energy resolution of (TURN)400 eV. Resonance spins, parities, partial widths, and channel spin and orbital angular momentum mixing ratios were extracted with a multi-level, multi-channel R-matrix based computer program. Resonance parameters were determined for 72 levels between 12.72 and 15.05 MeV in the compound system ('24)Mg. An additional nineteen resonances were identified between 15.05 and 16.67 MeV in ('24)Mg; the resonance parameters for these states are incomplete. Two isobaric analog states were identified and two others tentatively located. Coulomb energies and proton spectroscopic factors were determined and compared with ('23)Na(d,p) spectroscopic factors. The s-wave proton strength function ratio of S(,J=2) / S(,J=1) was approximately one. This ratio can be used to set limits on the effective spin-spin interaction between projectile and target. The reduced width sum rule for proton and alpha decay is discussed and comparisons made with the present data. Results from this study indicate that additional measurements and analysis are required in several areas. Spectroscopic information on states in ('24)Na should be extended to allow additional identification of analog states. Improved methods are needed to evaluate and interpret alpha spectroscopic factors. Additional experiments to measure alpha angular distributions will be required to provide resonance parameters for states above E(,p) = 3 MeV.

Vanhoy, Jeffrey Rahn

178

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

179

Nuclear magnetic resonance imaging.  

PubMed

NMR imaging is based on the ability to induce and monitor resonance of the magnetic moment of nuclei with an odd number of protons and/or neutrons in the presence of magnetic fields. By the use of magnetic fields whose strength varies with position, it is possible to define both the location and concentration of resonant nuclei, and, thereby, to create images that reflect their distribution in tissue. Hydrogen because it is the most sensitive of the stable nuclei to NMR and because it is also the most abundant nucleus in the body, is ideally suited for NMR imaging. PMID:7323305

Crooks, L; Herfkens, R; Kaufman, L; Hoenninger, J; Arakawa, M; McRee, R; Watts, J

1981-01-01

180

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

181

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

182

Magnetic resonance annual, 1988  

SciTech Connect

This book features reviews of high-resolution MRI of the knee, MRI of the normal and ischmeic hip, MRI of the heart, and temporomandibular joint imaging, as well as thorough discussion on artifacts in magnetic resonance imaging. Contributors consider the clinical applications of gadolinium-DTPA in magnetic resonance imaging and the clinical use of partial saturation and saturation recovery sequences. Timely reports assess the current status of rapid MRI and describe a new rapid gated cine MRI technique. Also included is an analysis of cerebrospinal fluid flow effects during MRI of the central nervous system.

Kressel, H.Y.

1987-01-01

183

Pygmy resonances and nucleosynthesis  

E-print Network

A microscopic theoretical approach based on a self-consistent density functional theory for the nuclear ground state and QRPA formalism extended with multi-phonon degrees of freedom for the nuclear excited states is implemented in investigations of new low-energy modes called pygmy resonances. Advantage of the method is the unified description of low-energy multiphonon excitations, pygmy resonances and core polarization effects. This is found of crucial importance for the understanding of the fine structure of nuclear response functions at low energies. Aspects of the precise knowledge of nuclear response functions around the neutron threshold are discussed in a connection to nucleosynthesis.

Tsoneva, Nadia

2014-01-01

184

Locally resonant sonic materials  

PubMed

We have fabricated sonic crystals, based on the idea of localized resonant structures, that exhibit spectral gaps with a lattice constant two orders of magnitude smaller than the relevant wavelength. Disordered composites made from such localized resonant structures behave as a material with effective negative elastic constants and a total wave reflector within certain tunable sonic frequency ranges. A 2-centimeter slab of this composite material is shown to break the conventional mass-density law of sound transmission by one or more orders of magnitude at 400 hertz. PMID:10976063

Liu; Zhang; Mao; Zhu; Yang; Chan; Sheng

2000-09-01

185

Optical fiber microcoil resonators  

NASA Astrophysics Data System (ADS)

The optical microfiber coil resonator with self-coupling turns is suggested and investigated theoretically. This type of a microresonator has a three-dimensional geometry and complements the well-known Fabry-Perot (one-dimensional geometry, standing wave) and ring (two-dimensional geometry, traveling wave) types of microresonators. The coupled wave equations for the light propagation along the adiabatically bent coiled microfiber are derived. The particular cases of a microcoil having two and three turns are considered. The effect of microfiber radius variation on the value of Q-factor of resonances is studied.

Sumetsky, M.

2004-05-01

186

Proton resonance spectroscopy  

SciTech Connect

Preparations for studying [sup 30]P via [sup 29]Si(p,[gamma]) have continued. We are exploring both the use of the Fourier transform and the statistical behavior of electromagnetic transition strengths within the shell model as alternate approaches to identifying quantum chaos in nuclei. Analysis of interfering resonances in (p,[alpha]) resonances suggests that improvements in the limits on detailed balance in nuclear reactions are possible, but several issues still must be considered before a definitive conclusion can be reached. Plans for a new control system for the High Resolution Laboratory's electrostatic analyzer are being implemented.

Shriner, J.F. Jr.

1992-11-01

187

Physics of Sports: Resonances  

NASA Astrophysics Data System (ADS)

When force is applied by an athlete to sports equipment resonances can occur. Just a few examples are: the ringing of a spiked volleyball, the strumming of a golf club shaft during a swing, and multiple modes induced in an aluminum baseball bat when striking a ball. Resonances produce acoustic waves which, if conditions are favorable, can be detected off the playing field. This can provide a means to evaluate athletic performance during game conditions. Results are given from the use of a simple hand-held acoustic detector - by a spectator sitting in the stands - to determine how hard volleyballs were spiked during college and high school games.

Browning, David

2000-04-01

188

Physics 2000: Resonance  

NSDL National Science Digital Library

This web page presents the physics of resonance of standing waves in a confined space. It is presented as a conversation between a student and a teacher, making it lively to read. There is a simulation that provides an animated illustration of resonance. The relation between the wavelength and the length of the confined space is described. Some practical examples are also cited. This is part of a tutorial on the physics of microwave ovens and the larger Physics 2000 web site. Physics 2000 introduces some of the results of modern physical science with interactive and engaging web presentations.

Physics 2000; Goldman, Martin

2007-05-15

189

P-31 nuclear magnetic resonance analysis of brain: Normoxic and anoxic brain slices  

Microsoft Academic Search

Perchloric acid extracts were prepared from liquid-N2-frozen gerbil and guinea pig brain slices studied under one of three conditions: O2-incubated, N2-incubated or O2-incubated recovery following N2 incubation. Mole percentages of the various phosphatic components contained in the extracts were determined by phosphorus-31 nuclear magnetic resonance spectroscopy. The brain slice extract spectrum revealed a previously unreported group of brain phosphodiesters at

Maynard M. Cohen; Jay W. Pettegrew; Stephen J. Kopp; Nancy Minshew; Thomas Glonek

1984-01-01

190

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

191

Experiment study of an electron cyclotron resonant ion source based on a tapered resonance cavity  

NASA Astrophysics Data System (ADS)

Electron cyclotron resonant plasma is one type of magnetised plasma generated by continuous microwave energy. It has the property of high degree of ionization and large volume at low gas pressure, which makes it useful for space propulsion and material processing. This article presents the experiment study of the plasma properties and ion beam extraction from an electron cyclotron resonant ion source based on a tapered resonance cavity. Optical emission spectroscopy based on a simple collisional radiation model was used for plasma diagnosis. Experiment results show that, at microwave power setting ranging from 7.06 to 17.40 W and mass flow rate ranging from 1 to 10 sccm, argon gas can be ionized. Ion beam of 109.1 mA from the ion source can be extracted at microwave power of 30 W, mass flow rate of 10 sccm, and accel voltage of 800 V. The diagnosed plasma temperature and density are 2.4-5.2 eV and 2 × 1016-4.8 × 1017 m-3, respectively.

Yang, Juan; Shi, Feng; Jin, Yizhou; Wang, Yunmin; Komurasaki, Kimiya

2013-12-01

192

Proton Resonance Spectroscopy in ARGON-36.  

NASA Astrophysics Data System (ADS)

Excitation functions for proton elastic scattering and for proton-induced reactions on ^{35 }Cl were measured with the KN Van de Graaff accelerator and associated high resolution system at TUNL. Differential cross sections for ^{35}Cl(p,p _0), (p,p_1), (p,p_2), (p,alpha _0), and (p,alpha_1 ) were measured in the range E_{ rm p} = 0.6 to 4.0 MeV. The data were measured at five angles with an overall resolution of about 350 eV. The measured excitation functions were analyzed with a multi-level, multi-channel R-matrix formalism for approximately 200 levels. Resonance parameters were extracted. The resonance parameters included resonance energy, total angular momentum, parity, partial elastic and reaction widths, channel spin or orbital angular momentum mixing ratios, and for some resonances the relative signs of width amplitudes. A number of resonances have strong level-level interference effects. Comparison of these data with the Porter-Thomas distribution resulted in good agreement of almost all channels which had a statistically significant number of resonances. These comparisons indicated that nearly all the proton and alpha strength in ^{36}Ar for this energy range was seen in the present study. The s -wave proton strength function ratio for s = 1 and s = 2 resonances was found to be consistent with previous measurements for 4N nuclei. This ratio can be used to set limits on the effective spin-spin interaction between projectil and target. The reduced width sum rule for proton and alpha decay is discussed and comparisons made with the present data. A large amount of alpha strength was observed for the 1^- states, and a very large amount of alpha strength was measured for the 2 ^+ and the 3^- states. The total alpha strength in the 2^+ and the 3^- states was on the order of a particle width. An appreciable amount of proton strength in the p-wave channels was also observed.

Brooks, William K., Jr.

193

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

194

Micromachined double resonator  

NASA Technical Reports Server (NTRS)

A micromachined resonator mountable to an external support structure has a proof mass coupled to a base structure by a first spring structure, the base structure having a plurality of electrodes, and a second spring structure coupling the base structure to the external support structure.

Gutierrez, Roman (Inventor); Tang, Tony K. (Inventor); Shcheglov, Kirill (Inventor)

2002-01-01

195

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

196

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

197

Exploring Resonance Phenomena.  

ERIC Educational Resources Information Center

Describes a demonstration where two 0.5-kg masses and two 1.0-kg masses are hung on springs on a suspended meterstick. The masses can be made to resonate by putting one partner mass in motion. Relates the motion to the history of the telegraph. (MVL)

Blacksten, H. Ric

1994-01-01

198

Electron Paramagnetic Resonance  

NSDL National Science Digital Library

Purpose â¢Use microwaves to induce and detect electron paramagnetic resonance. â¢Become familiar with a waveguide spectrometer and phase-sensitive detection. â¢Measure the gyromagnetic ratio and transverse relaxation time of the nearly-free electrons in DPPH.

2012-01-18

199

Magnetic Resonance Annual, 1985  

SciTech Connect

The inaugural volume of Magnetic Resonance Annual includes reviews of MRI of the posterior fossa, cerebral neoplasms, and the cardiovascular and genitourinary systems. A chapter on contrast materials outlines the mechanisms of paramagnetic contrast enhancement and highlights several promising contrast agents.

Kressel, H.Y.

1985-01-01

200

Proton resonance spectroscopy  

SciTech Connect

This report discusses the following topics: Complete Level Scheme for {sup 30}P; A Search for Resonances Suitable for Tests of Detailed-Balance Violation; The Fourier Transform as a Tool for Detecting Chaos; Entrance Channel Correlations in p + {sup 27}Al; The Parity Dependence of Level Densities in {sup 49}V; and A Computer Program for the Calculation of Angular Momentum Coupling.

Shriner, J.F. Jr.

1991-11-01

201

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

202

Magnetic Resonance Imaging  

NSDL National Science Digital Library

This lesson ties the preceding lessons together and brings students back to the grand challenge question on MRI safety. During this lesson, students focus on the logistics of magnetic resonance imaging as well as the MRI hardware. Students can then integrate this knowledge with their acquired knowledge on magnetic fields to solve the challenge question.

VU Bioengineering RET Program, School of Engineering,

203

Resonance capture at arbitrary inclination  

E-print Network

Resonance capture is studied numerically in the three-body problem for arbitrary inclinations. Massless particles are set to drift from outside the 1:5 resonance with a Jupiter-mass planet thereby encountering the web of the planet's diverse mean motion resonances. Randomly constructed samples explore parameter space for inclinations from 0 to 180 deg with 5deg increments totalling nearly 6x10^5 numerical simulations. Thirty resonances internal and external to the planet's location are monitored. We find that retrograde resonances are unexpectedly more efficient at capture than prograde resonances and that resonance order is not necessarily a good indicator of capture efficiency at arbitrary inclination. Capture probability drops significantly at moderate sample eccentricity for initial inclinations in the range [10deg,110deg]. Orbit inversion is possible for initially circular orbits with inclinations in the range [60deg,130deg]. Capture in the 1:1 coorbital resonance occurs with great likelihood at large re...

Namouni, Fathi

2014-01-01

204

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

205

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

206

Analysis of Blood Glucose Concentration by Interstitial Fluid Extracted in a Minimally Invasive way  

Microsoft Academic Search

A novel minimally invasive way to measure blood glucose concentration is proposed by combining interstitial fluid (ISF) transdermal extraction and surface plasmon resonance (SPR) detection. 55 kHz low-frequency ultrasound pulses are applied for 30 seconds to enhance the skin permeability and then interstitial fluid is extracted out of skin by vacuum. The glucose concentration in the interstitial fluid is determined

Xiaotang Hu; Kexin Xu; Xuejun Cao; Xinghua Qu; Dachao Li

2009-01-01

207

Interphase mobility and migration of hydrophobic organic metal extractant molecules in solvent-impregnated resins  

Microsoft Academic Search

Solvent-impregnated resins (SIRs) were made from polyvinyl pyridine and polyvinyl benzyl ammonium types of ionic polymers by impregnation of thiophosphoric acid type extractants. Morphological and nuclear magnetic resonance (NMR) studies were performed to observe the physical migration of the extractants under variation of two chemical factors: acidity and metal concentration. Morphological (surface area) measurements of the SIR-type polymer reveal surface

Abraham Warshawsky; Alex G. Strikovsky; Mark Y. Vilensky; Karel Jerabek

2002-01-01

208

Structure of wood extract colloids and effect of CaCl2 on the molecular mobility  

E-print Network

-layered model for the colloid structure for both pinus and spruce wood extracts has been proposed (Qin et alStructure of wood extract colloids and effect of CaCl2 on the molecular mobility Roland Lee, Karen J. Turro KEYWORDS: Wood resin, Pitch, Colloid structure, Electron paramagnetic resonance

Turro, Nicholas J.

209

Efficient utilization of licorice root by alkaline extraction.  

PubMed

Compared to studies of water extracts of plants, those utilising alkaline extracts are limited. Both water and alkaline extracts from licorice root were compared regarding their biological activities. Licorice root was successively extracted first with water or alkaline solution (pH 9 or 12), and the alkaline (pH 12.0) extract was further separated into 50% ethanol-soluble and -insoluble fractions. Viable cell number was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. Antibacterial activity against Porphyromonas gingivalis 381 was determined by turbidity assay. Cytochrome P-450 (CYP)3A4 activity was measured by ?-hydroxylation of testosterone using human recombinant CYP3A4. Radical intensity of superoxide and hydroxyl radicals was determined by electron spin resonance spectroscopy. Alkaline extraction yielded slightly higher amounts of dried materials compared to water extraction. Alkaline extract showed higher anti-HIV and antibacterial activities, and similar magnitudes of CYP3A4 inhibitory and superoxide and hydroxyl radical-scavenging activities, compared to water extract. When alkaline extract was fractionated by 50% ethanol, anti-HIV activity was recovered from the insoluble fraction representing approximately 3% of the alkaline extract, whereas antibacterial activity was concentrated in the soluble fraction rich in glycyrrhizid acid, flavanones and chalcones. All extracts and sub-fractions led to bimodal hormetic dose-response (maximum hormetic response=238%) on the bacterial growth. The present study demonstrated the superiority of alkaline extraction over water extraction for preparing anti-HIV and antibacterial agents at higher yield from licorice root. PMID:25189890

Ohno, Hirokazu; Miyoshi, Shozo; Araho, Daisuke; Kanamoto, Taisei; Terakubo, Shigemi; Nakashima, Hideki; Tsuda, Tadashi; Sunaga, Katsuyoshi; Amano, Shigeru; Ohkoshi, Emika; Sakagami, Hiroshi; Satoh, Kazue; Yamamoto, Masaji

2014-01-01

210

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

211

Eigenproblems in Resonant MEMS Design  

E-print Network

Eigenproblems in Resonant MEMS Design David Bindel UC Berkeley, CS Division Eigenproblems inResonant MEMS Design ­ p.1/21 #12;What are MEMS? Eigenproblems inResonant MEMS Design ­ p.2/21 #12;RF MEMS (better cell phones) Sensing elements (e.g. chemical sensors) Really high-pitch guitars Eigenproblems in

Bai, Zhaojun

212

Magnetic Resonance Facility (Fact Sheet)  

SciTech Connect

This fact sheet provides information about 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 analyze solid and liquid samples on three nuclear magnetic resonance (NMR) spectrometers as well as an electron paramagnetic resonance (EPR) spectrometer.

Not Available

2012-03-01

213

Arnold Flames Resonance Surface Folds*  

E-print Network

Arnold Flames and Resonance Surface Folds* Richard P. McGehee School of Mathematics University parameter plane bifurcation diagrams are "(Arnold) resonance horns" emanating from zero forcing ampli- tude families by Arnold [1983] and Hall [1984] indi- cate the presence of (Arnold) resonance horns emanating

Peckham, Bruce B.

214

Pygmy dipole resonance  

NASA Astrophysics Data System (ADS)

The pygmy dipole resonance (PDR) is a low-energy debris of the 1hslash? El-strength which is pushed by an isovector residual interaction to higher energies to form the giant dipole resonance. It exhausts about 1% of the EWSR below the particle threshold. High energy resolution experiments performed during the last decade reveal fine structure of the PDR in many nuclei. We report on the studies of the PDR fine structure performed within the Quasiparticle-Phonon model. Excited states are described by a wave function which includes one-, two-, and three-phonon configurations, i.e. the configuration space in calculations below the threshold is almost complete. We discuss also some particular features of the PDR excitation in different nuclear reactions.

Ponomarev, Vladimir

2014-09-01

215

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. PMID:23486058

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

2013-01-01

216

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

217

Injection-controlled laser resonator  

DOEpatents

A new injection-controlled laser resonator incorporates self-filtering and self-imaging characteristics with an efficient injection scheme. A low-divergence laser signal is injected into the resonator, which enables the injection signal to be converted to the desired resonator modes before the main laser pulse starts. This injection technique and resonator design enable the laser cavity to improve the quality of the injection signal through self-filtering before the main laser pulse starts. The self-imaging property of the present resonator reduces the cavity induced diffraction effects and, in turn, improves the laser beam quality.

Chang, Jim J. (Dublin, CA)

1995-07-18

218

Resonance production from jet fragmentation  

E-print Network

Short lived resonances are sensitive to the medium properties in heavy-ion collisions. Heavy hadrons have larger probability to be produced within the quark gluon plasma phase due to their short formation times. Therefore heavy mass resonances are more likely to be affected by the medium, and the identification of early produced resonances from jet fragmentation might be a viable option to study chirality. The high momentum resonances on the away-side of a triggered di-jet are likely to be the most modified by the partonic or early hadronic medium. We will discuss first results of triggered hadron-resonance correlations in Cu+Cu heavy ion collisions.

Christina Markert; STAR Collaboration

2009-07-17

219

Resonance Ionization spectroscopy  

NASA Astrophysics Data System (ADS)

The paper presents a retrospective view on the appearance and early development of Resonance Ionization Spectroscopy (RIS) and briefly reviews its basic principles and unique characteristics. Most of the paper concentrates on RIS applications that are most active at present time including on-line facilities with particle accelerators, counting noble gas atoms, ultrasensitive and highly selective techniques, analytical systems which use RIS in combination with thermal atomization (TARIS), laser atomization (LARIS), ion sputtering (SIRIS) and collisional ionization (LEI).

Bekov, G. I.

1995-04-01

220

Resonance Ionization spectroscopy  

SciTech Connect

The paper presents a retrospective view on the appearance and early development of Resonance Ionization Spectroscopy (RIS) and briefly reviews its basic principles and unique characteristics. Most of the paper concentrates on RIS applications that are most active at present time including on-line facilities with particle accelerators, counting noble gas atoms, ultrasensitive and highly selective techniques, analytical systems which use RIS in combination with thermal atomization (TARIS), laser atomization (LARIS), ion sputtering (SIRIS) and collisional ionization (LEI)

Bekov, G. I. [Atom Sciences, Inc., 114 Ridgeway Center, Oak Ridge, TN, 37830 (United States); Institute of Spectroscopy Russian Academy of Sciences, Troitsk, Moscow Region 142092 (Russian Federation)

1995-04-01

221

Direct magnetic resonance arthrography.  

PubMed

Magnetic resonance (MR) arthrography has gained increasing popularity as a diagnostic tool in the assessment of intra-articular derangements. Its role has been studied extensively in the shoulder, but it also has been explored in the hip, elbow, knee, wrist and ankle. This article reviews the current role of direct MR arthrography in several major joints, with consideration of pertinent anatomy, techniques and applications. PMID:15351900

Elentuck, Dmitry; Palmer, William E

2004-11-01

222

Microwave dielectric resonators  

NASA Astrophysics Data System (ADS)

A historical review and a status report on the state of the art of microwave dielectric resonators are presented. Early experimental works predating practical applications are noted, including work on rutile in the 1960s and the breakthrough development of stable low-less barium tetratitanate ceramics. Topics include: theory of operation, coupling to microwave structures, ceramic materials, applications, various filters, diode oscillators, and FET or bipolar transistor oscillators.

Fiedziuszko, S. J.

1986-09-01

223

Optical fiber microcoil resonators  

Microsoft Academic Search

The optical microfiber coil resonator with self-coupling turns is suggested and investigated theoretically. This type of a microresonator has a three-dimensional geometry and complements the well-known Fabry-Perot (one-dimensional geometry, standing wave) and ring (two-dimensional geometry, traveling wave) types of microresonators. The coupled wave equations for the light propagation along the adiabatically bent coiled microfiber are derived. The particular cases of

M. Sumetsky

2004-01-01

224

Cardiovascular Magnetic Resonance  

Microsoft Academic Search

\\u000a Cardiovascular magnetic resonance (CMR) creates images from atomic nuclei with uneven spin using radio waves in the presence\\u000a of a magnetic field. Full details of the physical principles can be found elsewhere [1]. For clinical purposes, MR is performed using hydrogen-1, which is abundant in water and fat. Radiofrequency waves excite\\u000a the area of interest to create tissue magnetization, which

Dudley J. Pennell

2001-01-01

225

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

226

Ghost-vibrational resonance  

E-print Network

Ghost-stochastic resonance is a noise-induced resonance at a fundamental frequency missing in the input signal. We investigate the effect of a high-frequency, instead of a noise, in a single Duffing oscillator driven by a multi-frequency signal $F(t)= \\sum^n_{i=1} f_i \\cos(\\omega_i + \\Delta \\omega_0)t$, $\\omega_i=(k+i-1)\\omega_0$, where $k$ is an integer greater than or equal to two. We show the occurrence of a high-frequency induced resonance at the missing fundamental frequency $\\omega_0$. For the case of the two-frequency input signal, we obtain an analytical expression for the amplitude of the periodic component with the missing frequency. We present the influence of the number of forces $n$, the parameter $k$, the frequency $\\omega_0$ and the frequency shift $\\Delta \\omega_0$ on the response amplitude at the frequency $\\omega_0$. We also investigate the signal propagation in a network of unidirectionally coupled Duffing oscillators. Finally, we show the enhanced signal propagation in the coupled oscillators in absence of a high-frequency periodic force.

S Rajamani; S Rajasekar; MAF Sanjuán

2014-04-22

227

Ghost-vibrational resonance  

NASA Astrophysics Data System (ADS)

Ghost-stochastic resonance is a noise-induced resonance at a fundamental frequency missing in the input signal. We investigate the effect of a high-frequency, instead of a noise, in a single Duffing oscillator driven by a multi-frequency signal F(t)=?i=1nficos(?i+??0)t, ?i=(k+i-1)?0, where k is an integer greater than or equal to two. We show the occurrence of a high-frequency induced resonance at the missing fundamental frequency ?0. For the case of the two-frequency input signal, we obtain an analytical expression for the amplitude of the periodic component with the missing frequency. We present the influence of the number of forces n, the parameter k, the frequency ?0 and the frequency shift ??0 on the response amplitude at the frequency ?0. We also investigate the signal propagation in a network of unidirectionally coupled Duffing oscillators. Finally, we show the enhanced signal propagation in the coupled oscillators in absence of a high-frequency periodic force.

Rajamani, S.; Rajasekar, S.; Sanjuán, M. A. F.

2014-11-01

228

Resonant non-gaussianity  

SciTech Connect

We provide a derivation from first principles of the primordial bispectrum of scalar perturbations produced during inflation driven by a canonically normalized scalar field whose potential exhibits small sinusoidal modulations. A potential of this type has been derived in a class of string theory models of inflation based on axion monodromy. We use this model as a concrete example, but we present our derivations and results for a general slow-roll potential with superimposed modulations. We show analytically that a resonance between the oscillations of the background and the oscillations of the fluctuations is responsible for the production of an observably large non-Gaussian signal. We provide an explicit expression for the shape of this resonant non-Gaussianity. We show that there is essentially no overlap between this shape and the local, equilateral, and orthogonal shapes, and we stress that resonant non-Gaussianity is not captured by the simplest version of the effective field theory of inflation. We hope our analytic expression will be useful to further observationally constrain this class of models.

Flauger, Raphael [Department of Physics, Yale University, New Haven, CT 06520 (United States); Pajer, Enrico, E-mail: raphael.flauger@yale.edu, E-mail: ep295@cornell.edu [Department of Physics, Cornell University, Ithaca, NY 14853 (United States)

2011-01-01

229

Antioxidant properties of aqueous extracts from red tide plankton cultures.  

PubMed

The antioxidant properties of aqueous extracts from the dinophycean flagellates Gymnodinium impudicum and Alexandrium affine and the raphidophycean flagellate Chattonella ovata were examined. An electron spin resonance (ESR)-spin trapping method coupled with steady state kinetic analysis showed that all of the extracts directly scavenge superoxide, and that the superoxide scavenging potential of any of the extracts was comparable to that of L-ascorbic acid. As for hydroxyl radical scavenging, the Fenton reaction and the method of ultraviolet radiation to hydrogen peroxide were used as hydroxyl radical generation systems. All of extracts reduced the level of hydroxyl radicals in both of the systems, indicating that the extracts also directly scavenge hydroxyl radicals. Since the levels of phenolic compounds did not correlate with the antioxidant activities of the extracts, substances other than phenolic compounds also appeared to be attributable to the activities. It is of our interest that the scavenging activities of extract from G. impudicum against superoxide and hydroxyl radicals were increased by heat exposure at 100 degrees C and 200 degrees C respectively. Although the reason for the increased activities of the aqueous extract from G. impudicum is not clear, the heat-resistance of the extract from G. impudicum might make it a desirable antioxidant. PMID:17485850

Niwano, Yoshimi; Sato, Emiko; Kohno, Masahiro; Matsuyama, Yukihiko; Kim, Daekyung; Oda, Tatsuya

2007-05-01

230

Extensive screening for herbal extracts with potent antioxidant properties  

PubMed Central

This paper summarizes our research for herbal extracts with potent antioxidant activity obtained from a large scale screening based on superoxide radical (O2•?) scavenging activity followed by characterization of antioxidant properties. Firstly, scavenging activity against O2•? was extensively screened from ethanol extracts of approximately 1000 kinds of herbs by applying an electron spin resonance (ESR)-spin trapping method, and we chose four edible herbal extracts with prominently potent ability to scavenge O2•?. They are the extracts from Punica granatum (Peel), Syzygium aromaticum (Bud), Mangifera indica (Kernel), and Phyllanthus emblica (Fruit). These extracts were further examined to determine if they also scavenge hydroxyl radical (•OH), by applying the ESR spin-trapping method, and if they have heat resistance as a desirable characteristic feature. Experiments with the Fenton reaction and photolysis of H2O2 induced by UV irradiation demonstrated that all four extracts have potent ability to directly scavenge •OH. Furthermore, the scavenging activities against O2•? and •OH of the extracts of P. granatum (peel), M. indica (kernel) and P. emblica (fruit) proved to be heat-resistant. The results of the review might give useful information when choosing a potent antioxidant as a foodstuff. For instance, the four herbal extracts chosen from extensive screening possess desirable antioxidant properties. In particular, the extracts of the aforementioned three herbs are expected to be suitable for food processing in which thermal devices are used, because of their heat resistance. PMID:21297917

Niwano, Yoshimi; Saito, Keita; Yoshizaki, Fumihiko; Kohno, Masahiro; Ozawa, Toshihiko

2011-01-01

231

Nonlinear Fano-Feshbach resonances.  

PubMed

We study the wave scattering in an one-dimensional discrete system with two side-coupled defects. Each of the defects exhibits the Fano resonance as a resonant suppression of transmission, i.e., resonant reflection. We demonstrate that the interaction between two Fano resonances may give rise to a birth of a very narrow resonance. This effect may be understood in terms of the overlapping resonances, as suggested by Feshbach [Ann. Phys. 5, 357 (1958)]. We consider two cases, when the defects are coupled either locally or nonlocally to the discrete array. In the latter case, a sharp asymmetric resonance appears with a large quality factor. We demonstrate that by introducing a nonlinearity at side-coupled defects a closed loop in the nonlinear transmission coefficient may appear, which results in bistable response. PMID:19391867

Miroshnichenko, Andrey E

2009-02-01

232

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

233

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

234

Wheat Germ DNA Extraction  

NSDL National Science Digital Library

This laboratory exercise is designed to show learners how DNA can easily be extracted from wheat germ 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

235

Avatar Information Extraction System  

Microsoft Academic Search

The AVATAR Information Extraction System (IES) at the IBM Almaden Research Center enables high- precision, rule-based, information extraction from text-documents. Draw ing from our experience we propose the use of probabilistic database techniques as the formal under pinnings of information extrac- tion systems so as to maintain high precision while increasing recall. This involve s building a frame- work where

T. S. Jayram; Rajasekar Krishnamurthy; Sriram Raghavan; Shivakumar Vaithyanathan; Huaiyu Zhu

2006-01-01

236

Standardization of allergen extracts.  

PubMed

Allergens are molecules with the capacity to elicit IgE responses in humans. When stimulated with allergens, most allergic patients respond with production of IgE specific for several proteins/allergens in the source material. The standardization of allergen extracts is essential in order to control variability and to achieve consistency and reproducibility in a clinical setting. Because the IgE binding capacity of an allergen extract is related to the content of one or a few major allergens, it is important that the standardization procedure ensures consistency, not only in the overall IgE binding potency, but also in the content and ratio of individual major allergens. Owing to the complexity of allergen extracts, a key element in standardization of allergen extracts is the use of standards. This chapter describes the principles for standardization of allergen extracts to be used by research laboratories. Other chapters in this volume describe methods in detail. PMID:18612605

Larsen, Jørgen Nedergaard; Dreborg, Sten

2008-01-01

237

Quartz crystal microbalance based on torsional piezoelectric resonators  

SciTech Connect

A quartz crystal microbalance (QCM) is described, which is based on a torsional resonator, rather than a conventional thickness-shear resonator. Typical applications are measurements of film thickness in the coating industry and monitoring of biofouling. The torsional QCM is about a factor of 100 less sensitive than the conventional QCM. On the other hand, it can probe film thicknesses in the range of hundreds of microns, which is impossible with the conventional QCM due to viscoelastic artifacts. Data acquisition and data analysis proceed in analogy to the conventional QCM. An indicator of the material's softness can be extracted from the bandwidth of the resonance. Within the small-load approximation, the frequency shift is independent of whether the sample is applied to the face or to the side of the cylinder. Details of the geometry matter if the viscoelastic properties of the sample are of interest.

Buecking, W.; Du, B.; Turshatov, A.; Koenig, A. M.; Reviakine, I.; Bode, B.; Johannsmann, D. [Institute of Physical Chemistry, Clausthal University of Technology, Arnold-Sommerfeld-Strasse 4, D-38678 Clausthal-Zellerfeld (Germany); Flucon Fluid Control GmbH, Burgstaetter Strasse 6, D-38678 Clausthal-Zellerfeld (Germany); Institute of Physical Chemistry, Clausthal University of Technology, Arnold-Sommerfeld-Strasse 4, D-38678 Clausthal-Zellerfeld (Germany)

2007-07-15

238

Ferromagnetic resonance in $\\epsilon$-Co magnetic composites  

E-print Network

We investigate the electromagnetic properties of assemblies of nanoscale $\\epsilon$-cobalt crystals with size range between 5 nm to 35 nm, embedded in a polystyrene (PS) matrix, at microwave (1-12 GHz) frequencies. We investigate the samples by transmission electron microscopy (TEM) imaging, demonstrating that the particles aggregate and form chains and clusters. By using a broadband coaxial-line method, we extract the magnetic permeability in the frequency range from 1 to 12 GHz, and we study the shift of the ferromagnetic resonance with respect to an externally applied magnetic field. We find that the zero-magnetic field ferromagnetic resonant peak shifts towards higher frequencies at finite magnetic fields, and the magnitude of complex permeability is reduced. At fields larger than 2.5 kOe the resonant frequency changes linearly with the applied magnetic field, demonstrating the transition to a state in which the nanoparticles become dynamically decoupled. In this regime, the particles inside clusters can ...

Chalapat, Khattiya; Huuppola, Maija; Koponen, Lari; Johans, Christoffer; Ras, Robin H A; Ikkala, Olli; Oksanen, Markku A; Seppälä, Eira; Paraoanu, G S

2014-01-01

239

Nonlinear wave-particle resonant interaction in the radiation belts: Landau resonance vs. fundamental cyclotron resonance  

NASA Astrophysics Data System (ADS)

We present selected THEMIS observations of highly-oblique and large amplitude chorus waves at medium latitudes. The major part of observed waves propagates at nearly-electrostatic mode with normal angles close to resonance cone. We use test particle simulations and analytical theory to estimate efficiency of nonlinear particle acceleration by these waves via Landau and fundamental cyclotron resonances. We show that trapping into the Landau resonance corresponds to a decrease of electron equatorial pitch-angles, while trapping into the first cyclotron resonance increases electron equatorial pitch-angles. For 100 keV electrons, the energy gain is larger for the trapping due to Landau resonance. Moreover, trapping into the Landau resonance is accessible for a wider range of initial pitch-angles in comparison with the fundamental resonance.

Krasnoselskikh, V.; Artemyev, A.; Agapitov, O. V.; Mourenas, D.

2013-12-01

240

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

241

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

242

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

PubMed

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. PMID:18315106

Todd, Damon S; Leitner, Daniela; Lyneis, Claude M; Grote, David P

2008-02-01

243

Electroexcitation of nucleon resonances  

SciTech Connect

We review recent progress in the investigation of the electroexcitation of nucleon resonances, both in experiment and in theory. The most accurate results have been obtained for the electroexcitation amplitudes of the four lowest excited states, which have been measured in a range of Q2 up to 8 and 4.5 GeV2 for the Delta(1232)P33, N(1535)S11 and N(1440)P11, N(1520)D13, respectively. These results have been confronted with calculations based on lattice QCD, large-Nc relations, perturbative QCD (pQCD), and QCD-inspired models. The amplitudes for the Delta(1232) indicate large pion-cloud contributions at low Q2 and don't show any sign of approaching the pQCD regime for Q2<7 GeV2. Measured for the first time, the electroexcitation amplitudes of the Roper resonance, N(1440)P11, provide strong evidence for this state as a predominantly radial excitation of a three-quark (3q) ground state, with additional non-3-quark contributions needed to describe the low Q2 behavior of the amplitudes. The longitudinal transition amplitude for the N(1535)S11 was determined and has become a challenge for quark models. Explanations may require large meson-cloud contributions or alternative representations of this state. The N(1520)D13 clearly shows the rapid changeover from helicity-3/2 dominance at the real photon point to helicity-1/2 dominance at Q2 > 0.5 GeV2, confirming a long-standing prediction of the constituent quark model. The interpretation of the moments of resonance transition form factors in terms of transition transverse charge distributions in infinite momentum frame is presented.

Inna Aznauryan, Volker D. Burkert

2012-01-01

244

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

245

Extracting the Max From a DNA Extraction  

NSDL National Science Digital Library

Students of all ages get a thrill out of actually seeing clumps or strands of DNA. The Biotechnology/Bioinformatics Discovery! Project, a professional development workshop offered to science teachers, has always included a DNA-extraction activity. Over the course of four years, as the authors conducted these workshops for scores of teachers, they extended and refined the DNA-extraction activity to make it relevant to middle school students. Although the protocol for this exercise is on their project website along with teaching tips, they describe here the use of oral directions to give teachers many opportunities to interact with their students, and to assess how well students can follow directions and stay focused on the task.

Marek, Edmund; Mulville, Charlotte; Bell, Don

2009-01-01

246

Resonance Ionization spectroscopy  

SciTech Connect

The paper presents a retrospective view on the appearance and early development of Resonance Ionization Spectroscopy (RIS) and briefly reviews its basic principles and unique characteristics. Most of the paper concentrates on RIS applications that are most active at present time including on-line facilities with particle accelerators, counting noble gas atoms, ultrasensitive and highly selective techniques, analytical systems which use RIS in combination with thermal atomization (TARIS), laser atomization (LARIS), ion sputtering (SIRIS) and collisional ionization (LEI). {copyright} 1995 {ital American} {ital Institute} {ital of} {ital Physics}

Bekov, G.I. [Atom Sciences, Inc., 114 Ridgeway Center, Oak Ridge, Tennessee, 37830 (United States)]|[Institute of Spectroscopy Russian Academy of Sciences, Troitsk, Moscow Region 142092 (Russian Federation)

1995-04-01

247

Doubly resonant ultrachirped pulses  

E-print Network

Ultrachirped pulses for which the frequency chirp is of the order of the transition frequency of a two-level atom are examined. When the chirp is large enough, the resonance may be crossed twice, for positive and negative quadrature frequencies. In this scenario the analytic signal and quadrature decompositions of the field into amplitude and phase factors turn out to be quite different. The corresponding interaction pictures are strictly equivalent, but only as long as approximations are not applied. The domain of validity of the formal rotating wave approximation is dramatically enhanced using the analytic signal representation.

S. Ibáñez; A. Peralta Conde; D. Guéry-Odelin; J. G. Muga

2011-05-26

248

Antiferroelectric spin wave resonance  

NASA Astrophysics Data System (ADS)

Antiferroelectric spin wave resonance (AFESWR) and electric spin moment, mathematically predicted by Dirac, were identified for the first time. It has also been found, in addition to well-known SSH-model, that topological quasiparticles, called ?-quasiparticles, can be formed in C sbnd C ?-bonds of organic polymers. Topological ?-polaron lattice is proposed to be responsible for the observed AFESWR both in starting polyvinylidene fluoride (PVDF) films and in carbynoid films, which are the products of PVDF-dehydrohalogenation. Dynamical systems of ?-polarons and ?-solitons, identified in the samples studied, are substantionally nonlinear and can be registered in stochastic regime by usual IR absorption measurements.

Yearchuck, D.; Yerchak, Y.; Alexandrov, A.

2009-01-01

249

Resonance energies of vinylcarbenes.  

PubMed

The stabilization energy provided by resonance in singlet and triplet vinylcarbenes is evaluated using density functional and G3 theory, without symmetry restriction. Structural and charge change upon rotation are reviewed with singlet vinylcarbene exhibiting a larger barrier (1s-TS-1s-E), 5.49 (7.10) kcal/mol, than triplet (1t-TS-1t-E), 4.06 (4.54) kcal/mol. The changes in charge upon rotation for singlet vinylcarbene are consistent with a simple resonance picture for the ground state, whereas there is insignificant charge change for the triplet. Difficulties of the rotational analysis are avoided by evaluating the inductive stabilization difference between ethyl and vinyl in isodesmic equation 1. This inductive difference was determined by comparing the energy change for hydrogen loss for polyene series 2 (n double bonds) with polyene series 3 (n double bonds), which are combined in isodesmic equation 4. The effect of the ultimate vinyl group in equation 2 is restricted to inductive interaction by holding its pi-system so it is orthogonal to the remaining pi-system. Extrapolation of plots of the inductive difference (Delta inductive) revealed for equation 4 versus a through-bond inductive attenuation of 1.75(-2n) to n = 0 provides a Delta inductive for singlet vinylcarbene of -4.52 kcal/mol (R = 0.995) at B3LYP/6-311+G(3df,2p)//B3LYP/6-31G(d) + ZPE at B3LYP/6-31G(d) and -4.16 (R = 0.993) at the G3(MP2)//B3LYP level. Correcting for Delta inductive in eq 1, the resonance energy of singlet vinylcarbene is 9.2 (8.9) kcal/mol. An analogous analysis of triplet vinylcarbene suggests that inductive effects are 0-1 kcal/mol, which leads to a resonance energy of 11-14 kcal/mol. PMID:19055381

Freeman, Peter K

2009-01-16

250

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

251

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

252

Lyapunov exponents in resonance multiplets  

E-print Network

The problem of estimating the maximum Lyapunov exponents of the motion in a multiplet of interacting nonlinear resonances is considered for the case when the resonances have comparable strength. The corresponding theoretical approaches are considered for the multiplets of two, three, and infinitely many resonances (i.e., doublets, triplets, and "infinitets"). The analysis is based on the theory of separatrix and standard maps. A "multiplet separatrix map" is introduced, valid for description of the motion in the resonance multiplet under certain conditions. In numerical experiments it is shown that, at any given value of the adiabaticity parameter (which controls the degree of interaction/overlap of resonances in the multiplet), the value of the maximum Lyapunov exponent in the multiplet of equally-spaced equally-sized resonances is minimal in the doublet case and maximal in the infinitet case. This is consistent with the developed theory.

I. I. Shevchenko

2013-12-19

253

Pitfalls of sequential extraction  

SciTech Connect

Sequential extraction procedures consist of subjecting a given sediment sample to a series of increasingly strong reagents under specified conditions. The most carefully designed and most often followed method is that of Tessier et al. (1979). These procedures, which were conceived as an attempt to determine the particulate speciation of trade elements and radionuclides, have serious limitations. Despite several studies demonstrating the instability of published methods for sequential extraction to determine chemical entities definable by more than the analytical method itself. The purpose of the comment is to discourage the expanding uncritical use of sequential extractions for measuring the particulate speciation of trade elements. (Copyright (c) 1990 Pergamon Press plc.)

Nirel, P.M.V.; Morel, F.M.M.

1994-01-01

254

Reactive oxygen scavenging effect of enzymatic extracts from Sargassum thunbergii.  

PubMed

The free radical scavenging activity of water soluble natural antioxidants from Sargassum thunbergii, which is a brown marine alga, was evaluated by examining the radical scavenging activities of the extracts of hydrolyzates from S. thunbergii on hydroxyl, 1,1-diphenyl-2-picrylhydrazyl (DPPH), and alkyl radicals. A spin-trapping electron spin resonance (ESR) spectrometer was employed, and the results were compared for their ESR signal intensity. S. thunbergii was enzymatically hydrolyzed to prepare water soluble extracts by five carbohydrases (AMG, Celluclast, Termamyl, Ultraflo, and Viscozyme) and proteases (Alcalase, Flavorzyme, Kojizyme, Neutrase, and Protamex). The scavenging activity of the radicals increased with increased concentrations of the extracts. The scavenging results were higher for hydroxyl and alkyl radicals and lower for DPPH radical as compared with vitamin C as a reference. The hydrogen peroxide scavenging activity of the extracts was also investigated; the Alcalase extract showed the highest scavenging activity among the extracts prepared with the five proteases and five carbohydrates. In addition, the DNA damage was determined by using the comet assay with alkaline electrophoresis and was quantified by measuring the tail length. The preventive effect of Alcalase extract from S. thunbergii against DNA damage increased with increments of concentration of the enzymatic extracts. PMID:16104782

Park, Pyo-Jam; Heo, Soo-Jin; Park, Eun-Ju; Kim, Se-Kwon; Byun, Hee-Guk; Jeon, Byong-Tae; Jeon, You-Jin

2005-08-24

255

Resonance capture and Saturn's rings  

SciTech Connect

We have assigned the resonances apparently responsible for the stabilization of the Saturn's shepherd satellites and for the substructure seen in the F-ring and the ringlets in the C-ring. We show that Saturn's narrow ringlets have a substructure determined by three-body resonances with Saturn's ringmoons and the sun. We believe such resonances have important implications to satellite formation. 17 refs., 1 fig., 1 tab.

Patterson, C.W.

1986-05-01

256

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

257

Optimized Design of Microcoil Resonators  

Microsoft Academic Search

Various methods to overcome the difficulties in the fabrication of high-quality (Q) optical nanofiber microcoil resonators are investigated. Modifications of the resonator geometry by wrapping the nanofiber over nonuniform rods and\\/or by varying the pitch alter the resonator Q-factor significantly. These effects are quantified, and geometries, which allow for enhanced tolerance to fabrication uncertainties, are identified. These simulations apply equally

Fei Xu; Peter Horak; Gilberto Brambilla

2007-01-01

258

Macroscopic resonances in planar geometry  

Microsoft Academic Search

Resonating response is a characteristic feature of free-particle system contained between two vibrating planar surfaces. Resonance frequencies and widths are determined by a mean period of motion of particles reflected from the walls. Resonances due to quasiperiodic macroscopic motion appear when the interaction among quasi-particles by means of perturbations of the common self-consistent field is included. They have finite widths

V. M. Strutinskii; S. M. Vydrug-Vlasenko; A. G. Magner

1987-01-01

259

MAGNETIC RESONANCE IN CHEMISTRY Magn. Reson. Chem. 37, 653661 (1999)  

E-print Network

alkaloids (Scheme 1) extracted from the opium poppy Papaver somniferum are known worldwide for their broad approach that would compete economically with the low cost of its extraction from opium poppy has yet

Hudlicky, Tomas

260

Ion cyclotron resonance cell  

DOEpatents

An ion cyclotron resonance cell is disclosed having two adjacent sections separated by a center trapping plate. The first section is defined by the center trapping plate, a first end trapping plate, and excitation and detector electrodes. The second section includes a second end trapping plate spaced apart from the center plate, a mirror, and an analyzer. The analyzer includes a wavelength-selective light detector, such as a detector incorporating an acousto-optical device (AOD) and a photodetector. One or more ion guides, grounded plates with holes for the ion beam, are positioned within the vacuum chamber of the mass spectrometer between the ion source and the cell. After ions are trapped and analyzed by ion cyclotron resonance techniques in the first section, the ions of interest are selected according to their mass and passed into the second section for optical spectroscopic studies. The trapped ions are excited by light from a laser and caused thereby to fluoresce. The fluorescent light emitted by the excited ions is reflected by the mirror and directed onto the detector. The AOD is scanned, and the photodetector output is recorded and analyzed. The ions remain in the second section for an extended period, enabling multiple studies to be carried out on the same ensemble of ions. 5 figs.

Weller, R.R.

1995-02-14

261

nuclear magnetic resonance gyroscope  

SciTech Connect

A nuclear magnetic resonance gyroscope which derives angular rotation thereof from the phases of precessing nuclear moments utilizes a single-resonance cell situated in the center of a uniform DC magnetic field. The field is generated by current flow through a circular array of coils between parallel plates. It also utilizes a pump and read-out beam and associated electronics for signal processing and control. Encapsulated in the cell for sensing rotation are odd isotopes of Mercury Hg/sup 199/ and Hg/sup 201/. Unpolarized intensity modulated light from a pump lamp is directed by lenses to a linear polarizer, quarter wave plate combination producing circularly polarized light. The circularly polarized light is reflected by a mirror to the cell transverse to the field for optical pumping of the isotopes. Unpolarized light from a readout lamp is directed by lenses to another linear polarizer. The linearly polarized light is reflected by another mirror to the cell transverse to the field and orthogonal to the pump lamp light. The linear light after transversing the cell strikes an analyzer where it is converted to an intensity-modulated light. The modulated light is detected by a photodiode processed and utilized as feedback to control the field and pump lamp excitation and readout of angular displacement.

Karwacki, F. A.; Griffin, J.

1985-04-02

262

Ion cyclotron resonance cell  

DOEpatents

An ion cyclotron resonance cell having two adjacent sections separated by a center trapping plate. The first section is defined by the center trapping plate, a first end trapping plate, and excitation and detector electrodes. The second section includes a second end trapping plate spaced apart from the center plate, a mirror, and an analyzer. The analyzer includes a wavelength-selective light detector, such as a detector incorporating an acousto-optical device (AOD) and a photodetector. One or more ion guides, grounded plates with holes for the ion beam, are positioned within the vacuum chamber of the mass spectrometer between the ion source and the cell. After ions are trapped and analyzed by ion cyclotron resonance techniques in the first section, the ions of interest are selected according to their mass and passed into the second section for optical spectroscopic studies. The trapped ions are excited by light from a laser and caused thereby to fluoresce. The fluorescent light emitted by the excited ions is reflected by the mirror and directed onto the detector. The AOD is scanned, and the photodetector output is recorded and analyzed. The ions remain in the second section for an extended period, enabling multiple studies to be carried out on the same ensemble of ions.

Weller, Robert R. (Aiken, SC)

1995-01-01

263

Resonant soliton-impurity interactions  

NASA Astrophysics Data System (ADS)

We describe a new type of soliton-impurity interaction and demonstrate that the soliton can be totally reflected by an attractive impurity if its initial velocity lies in certain resonance ``windows.'' This effect has an analogy with the resonance phenomena in kink-antikink collisions [Campbell, Schonfeld, and Wingate, Physica (Amsterdam) 9D, 1 (1983)], and it can be explained by a resonant energy exchange between the soliton and the impurity mode. Taking the sine-Gordon and ?4 models as examples, we find a number of resonance windows by numerical simulations and develop a collective-coordinate approach to describe the effect analytically.

Kivshar, Yuri S.; Fei, Zhang; Vázquez, Luis

1991-09-01

264

New approach to resonance crossing.  

PubMed

Time-varying nonlinear oscillatory systems produce phenomena of resonance crossing and trapping of particles in resonance islands. Traditionally, such processes have been analyzed in terms of adiabatic conditions. Considering, as an example, a simplified one-dimensional model describing the "electron-cloud pinch" during a bunch passage in a particle accelerator, here we present an approach to resonance trapping which does not require any adiabatic condition. Instead we introduce the concept of the attraction point and investigate invariance and scaling properties of motion close to the attraction point, considering a single resonance crossing. PMID:23368210

Franchetti, G; Zimmermann, F

2012-12-01

265

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

266

Optimized Design of Microcoil Resonators  

NASA Astrophysics Data System (ADS)

Various methods to overcome the difficulties in the fabrication of high-quality (Q) optical nanofiber microcoil resonators are investigated. Modifications of the resonator geometry by wrapping the nanofiber over nonuniform rods and/or by varying the pitch alter the resonator Q-factor significantly. These effects are quantified, and geometries, which allow for enhanced tolerance to fabrication uncertainties, are identified. These simulations apply equally to the fabrication of high-Q microcoil resonators with nanofibers suspended in air or embedded in low-refractive-index materials.

Xu, Fei; Horak, Peter; Brambilla, Gilberto

2007-06-01

267

Acoustic interpretation of resonant voice.  

PubMed

Resonant voice, often described in terms of vibratory sensations in the face, is investigated acoustically by calculating vocal tract inertance. It appears that the ease of production and vibrancy of resonant voice depends more on lowering phonation threshold pressure than on tissue or air resonance in or around the face. Phonation threshold pressure is lowered by increasing air column inertance in the laryngeal vestibule. The fact that the sensations are felt in the face is an indication of effective conversion of aerodynamic energy to acoustic energy, rather than sound resonation in the sinuses or the nasal airways. PMID:11792028

Titze, I R

2001-12-01

268

Electromagnetic production of hyperon resonances  

E-print Network

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 $K_0(800)$ meson. Properties of other hyperon resonances will also be studied in the near future.

K. Hicks; D. Keller; W. Tang

2010-12-14

269

Resonance in Asymmetric Warped Geometry  

E-print Network

We study the spectrum of an asymmetric warped braneworld model with different AdS curvatures on either side of the brane. In addition to the RS-like modes we find a resonance state. Its mass is proportional to the geometric mean of the two AdS curvature scales, while the difference between them determines the strength of the resonance peak. There is a complementarity between the RS zero-mode and the resonance: making the asymmetry stronger weakens the zero-mode but strengthens the resonance, and vice versa. We calculate numerically the braneworld gravitational potential and discuss the holographic correspondence for the asymmetric model.

Gregory Gabadadze; Luca Grisa; Yanwen Shang

2006-04-28

270

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.

271

Threshold voltage extraction circuit  

E-print Network

A novel optimally self-biasing MOSFET threshold-voltage (V[]) extractor circuit is presented. It implements the most popular industrial extraction algorithm of biasing a saturated MOSFET to the linear portion of its [] versus [] characteristic...

Hoon, Siew Kuok

2012-06-07

272

Opto-Acoustic Biosensing with Optomechanofluidic Resonators  

E-print Network

Opto-mechano-fluidic resonators (OMFRs) are a unique optofluidics platform that can measure the acoustic properties of fluids and bioanalytes in a fully-contained microfluidic system. By confining light in ultra-high-Q whispering gallery modes of OMFRs, optical forces such as radiation pressure and electrostriction can be used to actuate and sense structural mechanical vibrations spanning MHz to GHz frequencies. These vibrations are hybrid fluid-shell modes that entrain any bioanalyte present inside. As a result, bioanalytes can now reflect their acoustic properties on the optomechanical vibrational spectrum of the device, in addition to optical property measurements with existing optofluidics techniques. In this work, we investigate acoustic sensing capabilities of OMFRs using computational eigenfrequency analysis. We analyze the OMFR eigenfrequency sensitivity to bulk fluid-phase materials as well as nanoparticles, and propose methods to extract multiple acoustic parameters from multiple vibrational modes. ...

Zhu, Kaiyuan; Carmon, Tal; Fan, Xudong; Bahl, Gaurav

2014-01-01

273

Charmonium resonances and Fano line shapes  

E-print Network

Anomalous line shapes of quarkonia are explained naturally as an interference effect of a $c\\bar c$ confined closed channel with the surrounding continua, well established in other fields of physics as Fano-resonances. We discuss a quark model coupled-channel analysis describing quarkonium as a mixing of closed $Q\\bar Q$ and molecular-like $D\\bar D$ open channels. The asymmetric line shapes observed in $\\psi(3770)$ production cross sections in $e^+e^-$ annihilation to $D^0\\bar{D}^0$ and $D^+ D^-$, respectively, are described very well. The method allows to extract directly from the data the amount of $Q\\bar Q \\leftrightarrow D\\bar D$ configuration mixing.

Xu Cao; H. Lenske

2014-08-24

274

Nuclear Resonance Fluorescence Measurements of High Explosives  

SciTech Connect

Pacific Northwest National Laboratory and Passport Systems have collaborated to perform Nuclear Resonance Fluorescence experiments using several high quality high-explosive simulant samples. These measurements were conducted to determine the feasibility of finding and characterizing high explosive material by NRF interrogation. Electron beams of 5.1, 5.3, 8, and 10 MeV were used to produce bremsstrahlung photon beams, which irradiated the samples. The gamma-ray spectra were collected using high-purity germanium detectors. Nitrogen-to-carbon ratios of the high-explosive simulants were extracted from the 5.1 and 5.3 MeV data and compare favorably with accepted values. Analysis of the 8 and 10 MeV data is in progress; preliminary isotopic comparisons within the samples are consistent with the expected results.

Caggiano, Joseph A.; Warren, Glen A.; Korbly, Steve; Hasty, R.; Klimenko, A.; Park, William H.

2007-12-31

275

Two-dimensional nuclear magnetic resonance petrophysics.  

PubMed

Two-dimensional nuclear magnetic resonance (2D NMR) opens a wide area for exploration in petrophysics and has significant impact to petroleum logging technology. When there are multiple fluids with different diffusion coefficients saturated in a porous medium, this information can be extracted and clearly delineated from CPMG measurements of such a system either using regular pulsing sequences or modified two window sequences. The 2D NMR plot with independent variables of T2 relaxation time and diffusion coefficient allows clear separation of oil and water signals in the rocks. This 2D concept can be extended to general studies of fluid-saturated porous media involving other combinations of two or more independent variables, such as chemical shift and T1/T2 relaxation time (reflecting pore size), proton population and diffusion contrast, etc. PMID:15833623

Sun, Boqin; Dunn, Keh-Jim

2005-02-01

276

Extraction of cyanobacterial endotoxin.  

PubMed

To simplify our efforts in acquiring toxicological information on endotoxins produced by cyanobacteria, a method development study was undertaken to identify relatively hazard-free and efficient procedures for their extraction. One article sourced and two novel methods were evaluated for their ability to extract lipopolysaccharides (LPSs) or endotoxins from cyanobacteria. The Limulus polyphemus amoebocyte lysate (LAL) assay was employed to compare the performance of a novel method utilizing a 1-butanol-water (HBW) solvent system to that of Westphal's (1965) phenol-water system (HPW) for the extraction of endotoxin from various cyanobacteria. The traditional HPW method extracted from 3- to 12-fold more endotoxin from six different cyanobacterial blooms and culture materials than did the novel HBW method. In direct contrast, the novel HBW method extracted ninefold more endotoxin from a non-microcystin producing Microcystis aeruginosa culture as compared to the HPW method. A solvent system utilizing N,N'-dimethylformamide-water (HDW) was compared to both the HPW and HBW methods for the extraction of endotoxin from natural samples of Anabaena circinalis, Microcystis flos-aquae, and a 1:1 mixture of Microcystis aeruginosa/Microcystisflos-aquae. The LAL activities of these extracts showed that the novel HDW method extracted two- and threefold more endotoxin from the Anabaena sample that did the HBW and HPW methods, respectively. The HDW method also extracted approximately 1.5-fold more endotoxin from the Microcystis flos-aquae sample as compared to both the HBW and HPW methods. On the other hand, the HBW method extracted 2- and 14-fold more endotoxin from the Microcystis flos-aquae/Microcystis aeruginosa mixture than did the HPW and HDW methods, respectively. Results of this study demonstrate that significant disparities exist between the physicochemical properties of the cell wall constituents not only of different cyanobacterial species but also of different strains of the same cyanobacterial species, as showing by the varying effectiveness of the solvent systems investigated. Therefore, a sole method cannot be regarded as universal and superior for the extraction of endotoxins from cyanobacteria. Nevertheless, the ability of the novel HBW and HDW methods to utilize easily handled organic solvents that are less hazardous than phenol render them attractive alternatives to the standard HPW method. PMID:14758595

Papageorgiou, John; Linke, Thomas A; Kapralos, Con; Nicholson, Brenton C; Steffensen, Dennis A

2004-02-01

277

Excitation of giant monopole resonance in 208Pb and 116Sn using inelastic deuteron scattering  

NASA Astrophysics Data System (ADS)

The excitation of the isoscalar giant monopole resonance (ISGMR) in 208Pb and 116Sn has been investigated using small-angle (including 0°) inelastic scattering of 100 MeV/u deuteron and multipole-decomposition analysis (MDA). The extracted strength distributions agree well with those from inelastic scattering of 100 MeV/u ? particles. These measurements establish deuteron inelastic scattering at Ed˜100 MeV/u as a suitable probe for extraction of the ISGMR strength with MDA, making feasible the investigation of this resonance in radioactive isotopes in inverse kinematics.

Patel, D.; Garg, U.; Itoh, M.; Akimune, H.; Berg, G. P. A.; Fujiwara, M.; Harakeh, M. N.; Iwamoto, C.; Kawabata, T.; Kawase, K.; Matta, J. T.; Murakami, T.; Okamoto, A.; Sako, T.; Schlax, K. W.; Takahashi, F.; White, M.; Yosoi, M.

2014-07-01

278

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

279

Beam Extraction and Transport  

E-print Network

This chapter gives an introduction to low-energy beam transport systems, and discusses the typically used magnetostatic elements (solenoid, dipoles and quadrupoles) and electrostatic elements (einzel lens, dipoles and quadrupoles). The ion beam emittance, beam space-charge effects and the physics of ion source extraction are introduced. Typical computer codes for analysing and designing ion optical systems are mentioned, and the trajectory tracking method most often used for extraction simulations is described in more detail.

Kalvas, T

2013-01-01

280

Thymus DNA Extractions  

NSDL National Science Digital Library

This laboratory exercise is designed to show learners how DNA can be extracted from a chunk of thymus (sweetbread) or liver. This experiment requires the use of a centrifuge (not included in cost of 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

281

Supercritical Fluid Extraction  

E-print Network

heating or isothermal decompression to the gaseous state. 3. Supercritical fluids can be used to vaporize thermally labile non-volatile substances at moderate temperatures, at which they are non-distillable. At these conditions, the selectivity may... be too low for liquid extraction. 4. Nontoxic, nonhazardous supercritical carbon dioxide can be used in the food and pharmaceutical industries without contaminating the product. Liquid extraction leaves residual toxic organic solvent in the product...

Johnston, K. P.; Flarsheim, W. M.

1984-01-01

282

Epulis granulomatosa: extraction sequellae.  

PubMed

Epulis granulomatosa is a post-surgical lesion emanating from an extraction socket. It can be misdiagnosed with lesions of similar appearance, for example, foreign body or pyogenic granulomas, or as a herniation of the maxillary sinus. Based on clinical appearance and microscopic description, granulomas all appear to represent essentially the same lesion. However, pathonomonically, the epulis granulomatosa emanates only from an extraction socket; the other granulomas can be found anywhere in the body. PMID:9693538

Leong, R; Seng, G F

1998-01-01

283

Fruitful DNA Extraction  

NSDL National Science Digital Library

In this lab activity, learners get to see and touch the genetic material they extract from the cells of a kiwi fruit - no high tech equipment required! After extraction and precipitation, learners will be able to collect the DNA with a wire hook. A facilitator's guide is included for helping educators run the activity, and background information is provided about what's going on, discussion questions, and ideas for inquiry. Biochemistry has never been so accessible - and fun!

Kalamuck, Karen; Exploratorium

2000-01-01

284

Overview of baryon resonances. Present status and perspectives  

NASA Astrophysics Data System (ADS)

The quest to understand the physics of any system cannot be said to be complete as long as one cannot predict and fully understand its resonance spectrum. Despite this, due to the experimental challenge of the required double polarization measurements and the difficulty in achieving unambiguous, model-independent extraction and interpretation of the nucleon resonance spectrum of many broad and overlapping resonances, understanding of the structure and dynamics of the nucleon has suffered. The recent improvement in statistical quality and kinematic range of the data made available by such full-solid-angle systems as the CB and TAPS constellation at MAMI, coupled with the high flux polarized photon beam provided by the Glasgow Photon Tagger, and the excellent properties of the Mainz Frozen Spin Target, when paired with new developments in Partial Wave Analysis (PWA) methodology make this a very exciting and fruitful time in nucleon resonance studies. Here the recent influx of data and PWA developments are summarized, and the requirements for a complete, unambiguous PWA solution over the first and second resonance region are briefly reviewed.

Downie, E. J.

2014-06-01

285

Meson-baryon dynamics as a tool for baryon resonance analysis  

SciTech Connect

The analytical properties of the scattering amplitudes, such as the poles and zeroes on the different Riemann sheets and their residues, determine the global behavior of the amplitude on the real axis. The poles and residues provide a parameterization of the resonances which does not depend on assumptions for the background, and thus allow to relate resonance contributions in different reactions. We show the resonance parameters extracted by using the Juelich coupled reaction channel approach to meson-nucleon scattering and discuss first applications of that approach to photon-induced meson production.

Doering, M.; Hanhart, C.; Krewald, S. [Institut fuer Kernphysik, Forschungszentrum, D-52425 Juelich (Germany); Haberzettl, H. [Center for Nuclear Studies, George Washington University, Washington D.C. (United States); Huang, F.; Nakayama, K. [Department of Physics and Astronomy, University of Athens, Georgia (United States); Meissner, U.-G. [Institut fuer Kernphysik, Forschungszentrum, D-52425 Juelich (Germany); Helmholtz-Institut fuer Strahlen-und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, University of Bonn, 53115 Bonn (Germany)

2010-07-27

286

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

287

Magnetic Resonance Imaging  

PubMed Central

Magnetic resonance imaging (MRI) is an important new imaging modality just arriving on the clinical scene in Canada. MRI uses no ionizing radiation; images are derived from the interaction of hydrogen nuclei, a powerful magnetic field, and radio waves. Images are displayed as tomographic slices, much like CT. Direct transverse, sagittal, coronal or oblique slices can be obtained. Unlike CT, the MRI image does not reflect varying tissue densities. In MRI, tissues are differentiated by variation in the amount of hydrogen they contain and by differences in the magnetic environment at a molecular level. All parts of the body can be examined with MRI, although the CNS is particularly well visualized. In addition to providing high resolution images, MRI has the potential for performing non-invasive angiography and biochemical analysis through spectroscopy. To date, there are no known harmful effects of MRI. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5 PMID:21267205

Fache, J. Stephen

1986-01-01

288

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

289

Baryon Spectroscopy and Resonances  

SciTech Connect

A short review of current efforts to determine the highly excited state spectrum of QCD, and in particular baryons, using lattice QCD techniques is presented. The determination of the highly excited spectrum of QCD is a major theoretical and experimental challenge. The experimental investigation of the excited baryon spectrum has been a long-standing element of the hadronic-physics program, an important component of which is the search for so-called 'missing resonances', baryonic states predicted by the quark model based on three constituent quarks but which have not yet been observed experimentally. Should such states not be found, it may indicate that the baryon spectrum can be modeled with fewer effective degrees of freedom, such as in quark-diquark models. In the past decade, there has been an extensive program to collect data on electromagnetic production of one and two mesons at Jefferson Lab, MIT-Bates, LEGS, MAMI, ELSA, and GRAAL. To analyze these data, and thereby refine our knowledge of the baryon spectrum, a variety of physics analysis models have been developed at Bonn, George Washington University, Jefferson Laboratory and Mainz. To provide a theoretical determination and interpretation of the spectrum, ab initio computations within lattice QCD have been used. Historically, the calculation of the masses of the lowest-lying states, for both baryons and mesons, has been a benchmark calculation of this discretized, finite-volume computational approach, where the aim is well-understood control over the various systematic errors that enter into a calculation; for a recent review. However, there is now increasing effort aimed at calculating the excited states of the theory, with several groups presenting investigations of the low-lying excited baryon spectrum, using a variety of discretizations, numbers of quark flavors, interpolating operators, and fitting methodologies. Some aspects of these calculations remain unresolved and are the subject of intense effort, notably the ordering of the Roper resonance in the low-lying Nucleon spectrum.

Robert Edwards

2011-12-01

290

Matryoshka locally resonant sonic crystal  

Microsoft Academic Search

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

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

2011-01-01

291

Giant resonances in Mg-24  

E-print Network

The giant resonance region in Mg-24 was studied with inelastic scattering of 240 MeV alpha particles at small angles including 0 degrees. The giant resonance peak was found to extend up to E-X = 41 MeV. Isoscalar E0, E1, and E2 strength...

Youngblood, David H.; Lui, YW; Clark, HL.

1999-01-01

292

Asteroid Secular Resonant Proper Elements  

Microsoft Academic Search

A practical algorithm for the computation of the dynamic evolution of asteroids which are inside or close to a secular resonance has been developed. The results are checked with many numerical simulations of both real and fictitious objects. These tests prove that the algorithm is able to identify the dynamic nature of resonant objects and distinguish between future planet crossers

Alessandro Morbidelli

1993-01-01

293

Homoclinic bifurcation at resonant eigenvalues  

Microsoft Academic Search

We consider a bifurcation of homoclinic orbits, which is an analogue of period doubling in the limit of infinite period. This bifurcation can occur in generic two parameter vector fields when a homoclinic orbit is attached to a stationary point with resonant eigenvalues. The resonance condition requires the eigenvalues with positive\\/negative real part closest to zero to be real, simple,

Shui-Nee Chow; Bo Deng; Bernold Fiedler

1990-01-01

294

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

295

Basics of Resonance Chiral Theory  

E-print Network

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 -> (3 pion) nu_tau decay.

J. Portoles

2010-10-16

296

Reactive absorbers Absorption around resonance  

E-print Network

1 Reactive absorbers · Absorption around resonance = 2 m" (-res) +..... ( m"- c 2/l)=(-res) d d [ m silencers ­ Expansion chamber ­ Branch resonator #12;3 Silencers Source ZS Duct 1 Z1 Duct 2 Z2 Receiver ZR

Berlin,Technische Universität

297

Matryoshka Locally Resonant Sonic Crystal  

E-print Network

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. Thi...

Elford, Daniel P; Kusmartsev, Feodor V; Swallowe, Gerry M

2011-01-01

298

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

299

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

300

Resonance Production in RHIC Collisions  

E-print Network

Results of resonance particle production measured at RHIC in $\\sqrt{s_{\\rm NN}} = $ 200 GeV Au+Au collisions are compared to measurements in p+p and d+Au collisions in order to verify the existence of an extended hardronically interacting medium. Yield and momentum distributions of resonances maybe modified during the fireball lifetime due to resonance decay and the subsequent rescattering of their decay daughters as well as the regeneration of resonances from their decay products. Modified momentum spectra in heavy ion collisions may change the nuclear modification factor R$_{\\rm AA}$. The influence on the elliptic flow v$_{2}$ due to late regeneration of resonances is discussed.

Christina Markert "for the" STAR collaboration

2007-06-05

301

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

302

Auxiliary resonant DC tank converter  

DOEpatents

An auxiliary resonant dc tank (ARDCT) converter is provided for achieving soft-switching in a power converter. An ARDCT circuit is coupled directly across a dc bus to the inverter to generate a resonant dc bus voltage, including upper and lower resonant capacitors connected in series as a resonant leg, first and second dc tank capacitors connected in series as a tank leg, and an auxiliary resonant circuit comprising a series combination of a resonant inductor and a pair of auxiliary switching devices. The ARDCT circuit further includes first clamping means for holding the resonant dc bus voltage to the dc tank voltage of the tank leg, and second clamping means for clamping the resonant dc bus voltage to zero during a resonant period. The ARDCT circuit resonantly brings the dc bus voltage to zero in order to provide a zero-voltage switching opportunity for the inverter, then quickly rebounds the dc bus voltage back to the dc tank voltage after the inverter changes state. The auxiliary switching devices are turned on and off under zero-current conditions. The ARDCT circuit only absorbs ripples of the inverter dc bus current, thus having less current stress. In addition, since the ARDCT circuit is coupled in parallel with the dc power supply and the inverter for merely assisting soft-switching of the inverter without participating in real dc power transmission and power conversion, malfunction and failure of the tank circuit will not affect the functional operation of the inverter; thus a highly reliable converter system is expected.

Peng, Fang Z. (Knoxville, TN)

2000-01-01

303

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

304

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

305

Synthesis of silver nanoparticles using medicinal Zizyphus xylopyrus bark extract  

NASA Astrophysics Data System (ADS)

In the present paper, biosynthesis of silver nanoparticles using Zizyphus xylopyrus bark extract is reported. Z. xylopyrus bark extract is efficiently used for the biosynthesis of silver nanoparticles. UV-Visible spectroscopy showed surface plasmon resonance peaks in the range 413-420 nm confirming the formation of silver nanoparticles. Different factors affecting the synthesis of silver nanoparticles like methodology for the preparation of extract, concentration of silver nitrate solution used for biosynthesis and initial pH of the reaction mixture were studied. The extract prepared with 10 mM AgNO3 solution by reflux extraction method at optimum initial pH of 11, resulted in higher conversion of silver ions to silver nanoparticles as compared with those prepared by open heating or ultrasonication. SEM analysis showed that the biosynthesized nanoparticles are spherical in nature and ranged from 60 to 70 nm in size. EDX suggested that the silver nanoparticles must be capped by the organic components present in the plant extract. This simple process for the biosynthesis of silver nanoparticles using aqueous extract of Z. xylopyrus is a green technology without the usage of hazardous and toxic solvents and chemicals and hence is environment friendly. The process has several advantages with reference to cost, compatibility for its application in medical and drug delivery, as well as for large-scale commercial production.

Sumi Maria, Babu; Devadiga, Aishwarya; Shetty Kodialbail, Vidya; Saidutta, M. B.

2014-11-01

306

Polariton path to fully resonant dispersive coupling in optomechanical resonators  

NASA Astrophysics Data System (ADS)

Resonant photoelastic coupling opens new perspectives for strongly enhanced light-sound interaction in semiconductor optomechanical resonators. One potential problem, however, is the reduction of the cavity Q factor induced by dissipation when the resonance is approached. We show in this Rapid Communication through Raman-scattering experiments that cavity-polariton mediation in the light-matter process overcomes this limitation allowing for a strongly enhanced photon-phonon coupling without significant lifetime reduction in the strong-coupling regime. Huge optomechanical coupling factors in the petaHz/nm range are envisaged, three orders of magnitude larger than the backaction produced by the mechanical displacement of the cavity mirrors.

Rozas, G.; Bruchhausen, A. E.; Fainstein, A.; Jusserand, B.; Lemaître, A.

2014-11-01

307

Approximate resonance states in the semigroup decomposition of resonance evolution  

E-print Network

The semigroup decomposition formalism makes use of the functional model for $C_{.0}$ class contractive semigroups for the description of the time evolution of resonances. For a given scattering problem the formalism allows for the association of a definite Hilbert space state with a scattering resonance. This state defines a decomposition of matrix elements of the evolution into a term evolving according to a semigroup law and a background term. We discuss the case of multiple resonances and give a bound on the size of the background term. As an example we treat a simple problem of scattering from a square barrier potential on the half-line.

Y. Strauss; L. P. Horwitz; A. Volovick

2006-12-04

308

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

309

Antioxidant Activities of Uyaku (Lindera Strychnifolia) Leaf Extract: A Natural Extract Used in Traditional Medicine  

PubMed Central

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 (O2·?) 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 (Fe2+ + H2O2)-induced lipid peroxidation, 2-thiobarbituric acid; for (Fe2+ + H2O2)-induced protein carbonyl, 2,4-dinitrophenylhydrazine. Analysis of ESR data of the extracts indicated the direct ·OH and O2·? 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

2007-01-01

310

Phytoplasma plasmid DNA extraction.  

PubMed

Phytoplasma plasmids have generally been detected from DNA extracted from plants and insects using methods designed for the purification of total phytoplasma DNA. Methods include extraction from tissues that are high in phytoplasma titre, such as the phloem of plants, with the use of CsCl-bisbenzimide gradients that exploit the low G+C content of phytoplasma DNA. Many of the methods employed for phytoplasma purification have been described elsewhere in this book. Here we describe in detail two methods that are specifically aimed at isolating plasmid DNA. PMID:22987431

Andersen, Mark T; Liefting, Lia W

2013-01-01

311

MAGNETIC RESONANCE IN CHEMISTRY Magn. Reson. Chem. 2007; 45: 937941  

E-print Network

of Chemistry, Lewis & Clark College, 0615 SW Palatine Hill Road, Portland, OR 97219, USA Received 25 June 2007 & Clark College, 0615 SW Palatine Hill Road, Portland, OR 97219, USA. E-mail: loening@lclark.edu resonance

Loening, Niko

312

Resonance production by neutrinos: The second resonance region  

E-print Network

The article contains new results for spin-3/2 and -1/2 resonances. It specializes to the second resonance region, which includes the $P_{11}(1440)$, $D_{13}(1520)$ and $S_{11}(1535)$ resonances. New data on electroproduction enable us to determine the vector form factors accurately. Estimates for the axial couplings are obtained from decay rates of the resonances with the help of the partially conserved axial current (PCAC) hypothesis. We present cross sections to be compared with the running and future experiments. The article is self--contained and allows the reader to write simple programs for reproducing the cross sections and for obtaining additional differential cross sections.

Olga Lalakulich; Emmanuel A. Paschos; Giorgi Piranishvili

2006-02-22

313

Enhanced Acoustic Energy Harvesting Using Coupled Resonance Structure of Sonic Crystal and Helmholtz Resonator  

NASA Astrophysics Data System (ADS)

An acoustic energy harvester using a coupled resonance structure of a sonic crystal resonator and an electromechanical Helmholtz resonator with a piezoelectric composite diaphragm is proposed to enhance energy harvesting. Due to acoustic resonance coupling between the sonic crystal resonator and the Helmholtz resonator, the coupled resonance structure has a larger acoustic pressure magnification than each individual resonator structure. Consequently, the stronger vibration of the diaphragm and the higher harvesting efficiency are obtained. Experimental results show that the proposed harvester exhibits ?23 and ?262 times higher maximum harvesting efficiencies than the sonic crystal resonator and the Helmholtz resonator structure, respectively.

Yang, Aichao; Li, Ping; Wen, Yumei; Lu, Caijiang; Peng, Xiao; Zhang, Jitao; He, Wei

2013-12-01

314

Nanoparticle arrays: From magnetic response to coupled plasmon resonances  

NASA Astrophysics Data System (ADS)

We study optical properties of optomagnetic metamaterials consisting of regular arrays of single and double Au nanodots (nanopillars). Using a combination of data from variable angle spectroscopic ellipsometry, transmission, and reflection measurements, we identify localized plasmon resonances of gold nanodots and measure their dependence on dot size and substrate type. We demonstrate that arrays of Au nanopillars can support narrow collective plasmon resonances coupled to in-plane and out-of-plane localized plasmon resonances. The spectral positions of these plasmon modes are extracted from the angular dependence of the transmission and reflection spectra for two beam polarizations. We show that nanoarrays exhibit dramatically different optical response on conductive and nonconductive substrates and study its angular dependence. The optical response of nanoarrays is described well by coupled dipole approximation. The procedure for extracting optical constants of metamaterials based on ellipsometry is discussed and applied to our samples resulting in a calculated negative index of refraction for double-dot arrays at green light.

Kravets, V. G.; Schedin, F.; Pisano, G.; Thackray, B.; Thomas, P. A.; Grigorenko, A. N.

2014-09-01

315

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

316

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

317

Ugo Fano and shape resonances  

SciTech Connect

Ugo Fano has been a leader in theoretical Physics in the XX century giving key contributions to our understanding of quantum phenomena. He passed away on 13 February 2001 after 67 years of research activity. I will focus on his prediction of the quantum interference effects to understand the high-energy photoabsorption cross section giving the 'Fano lineshapes'. The Fano results led to the theoretical understanding of 'shape resonances' (called also 'Feshbach resonances') that should be better called 'Fano resonances'. Finally I will show that today this Fano quantum interference effect is behind several new physical phenomena in different fields.

Bianconi, Antonio [Dipartimento di Fisica, Universita di Roma 'La Sapienza', P.le Aldo Moro 2, 00185 Rome (Italy)

2003-01-24

318

Conditions for sustained resonance. II  

NASA Astrophysics Data System (ADS)

A generalized form of Kerkorian's (1974, 1978) model of sustained reentry roll resonance, which occurs when a slightly asymmetric ballistic spacecraft reenters the earth's atmosphere, is examined using a method proposed by Haberman (1983). This method determines the width of the energy band in which solutions are entrained into sustained resonance, thereby enabling a sufficient condition for entrainment to and continuation of sustained resonance to be given. Both the width of the energy band and the sufficient condition are calculated in terms of the slowly varying pitching and yawing frequency, which is assumed to be known.

Kath, W. L.

1983-06-01

319

Resonant Excitation of Plasma Wakefields  

SciTech Connect

We describe characteristics of the bunch train and plasma source used in a resonant plasma wakefield experiment at the Brookhaven National Laboratory Accelerator Test Facility. The bunch train has the proper correlated spread to unambiguously observe the expected energy gain by the witness bunch at resonance. The plasma density in the capillary discharge is sufficiently high to reach the resonance with the typical bunch train spacing of this experiment. It is also uniform over more than 3/4 of the 2 cm-long capillary.

Muggli, P.; Allen, B. [University of Southern California, Los Angeles, CA 90089 (United States); Yakimenko, V.; Fedurin, M.; Kusche, K.; Babzien, M. [Brookhaven National Laboratory, Upton, NY 11973 (United States)

2010-11-04

320

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

321

Top quark as a resonance  

E-print Network

We suggest the description of the dressed fermion propagator with parity non-conservation in the form with separated positive and negative energy poles. We found general form of the $\\gamma$-matrix off-shell projectors and corresponding resonance factors. The parity violation leads to deviation of resonance factors from the naive Breit--Wigner form and to appearance of non-trivial spin corrections. However, for top quark with SM vertex the resonance factor returns to the standard one due to $\\Gamma/m\\ll1$.

A. E. Kaloshin; V. P. Lomov

2011-11-05

322

Magnetic resonance cell  

SciTech Connect

There is disclosed a nuclear magnetic alignment device for use in a nuclear magnetic resonance gyroscope and the like. One embodiment includes a container for gas having a layer of rubidium hydride on its inner surface. The container comprising a spherical portion and a tip portion, is rotationally symmetric about an axis of symmetry. Enclosed within the container is a nuclear moment gas having a nuclear electric quadrupole moment, such as xenon-131, and an optically pumpable substance, such as rubidium. A portion of the rubidium is a vapor. The remainder is a condensed pellet which is deposited in the tip of the container such that the pellet is also rotationally symmetric about the axis of symmetry of the container. A layer of rubidium hydride is deposited on the inner surface of the container. The device further includes means for orienting the symmetry axis of the container at an angle to an applied magnetic field such that the relaxation time constant of the aligned nuclear moment gas is substantially at a maximum.

Kwon, T.M.; Volk, C.H.

1984-05-01

323

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

324

Neutron physics of the Re\\/Os clock. III. Resonance analyses and stellar (n,gamma) cross sections of Os186,187,188  

Microsoft Academic Search

Neutron resonance analyses have been performed for the capture cross sections of Os186, Os187, and Os188 measured at the n_TOF facility at cern. Resonance parameters have been extracted up to 5, 3, and 8 keV, respectively, using the sammy code for a full R-matrix fit of the capture yields. From these results average resonance parameters were derived by a statistical

K. Fujii; M. Mosconi; A. Mengoni; C. Domingo-Pardo; F. Käppeler; U. Abbondanno; G. Aerts; H. Álvarez-Pol; F. Alvarez-Velarde; S. Andriamonje; J. Andrzejewski; P. Assimakopoulos; L. Audouin; G. Badurek; P. Baumann; F. Becvár; F. Belloni; E. Berthoumieux; S. Bisterzo; M. Calviani; F. Calviño; D. Cano-Ott; R. Capote; A. Carrillo de Albornoz; P. Cennini; V. Chepel; E. Chiaveri; N. Colonna; G. Cortes; A. Couture; J. Cox; M. Dahlfors; S. David; I. Dillmann; R. Dolfini; W. Dridi; I. Duran; C. Eleftheriadis; M. Embid-Segura; L. Ferrant; A. Ferrari; R. Ferreira-Marques; L. Fitzpatrick; H. Frais-Koelbl; W. Furman; R. Gallino; I. Goncalves; E. Gonzalez-Romero; A. Goverdovski; F. Gramegna; E. Griesmayer; C. Guerrero; F. Gunsing; B. Haas; R. Haight; M. Heil; A. Herrera-Martinez; M. Igashira; S. Isaev; E. Jericha; Y. Kadi; D. Karamanis; D. Karadimos; M. Kerveno; V. Ketlerov; P. Koehler; V. Konovalov; E. Kossionides; M. Krticka; C. Lamboudis; H. Leeb; A. Lindote; I. Lopes; M. Lozano; S. Lukic; J. Marganiec; L. Marques; S. Marrone; C. Massimi; P. Mastinu; P. M. Milazzo; C. Moreau; F. Neves; H. Oberhummer; M. Oshima; S. O'Brien; J. Pancin; C. Papachristodoulou; C. Papadopoulos; C. Paradela; N. Patronis; A. Pavlik; P. Pavlopoulos; L. Perrot; R. Plag; A. Plompen; A. Plukis; A. Poch; J. Praena; C. Pretel; J. Quesada; T. Rauscher; R. Reifarth; M. Rosetti; C. Rubbia; G. Rudolf; P. Rullhusen; J. Salgado; L. Sarchiapone; I. Savvidis; C. Stephan; G. Tagliente; J. L. Tain; L. Tassan-Got; L. Tavora; R. Terlizzi; G. Vannini; P. Vaz; A. Ventura; D. Villamarin; M. C. Vincente; V. Vlachoudis; R. Vlastou; F. Voss; S. Walter; H. Wendler; M. Wiescher; K. Wisshak

2010-01-01

325

Neutron physics of the Re\\/Os clock. III. Resonance analyses and stellar (n, ) cross sections of 186,187,188Os  

Microsoft Academic Search

Neutron resonance analyses have been performed for the capture cross sections of 186Os, 187Os, and 188Os measured at the n TOF facility at CERN. Resonance parameters have been extracted up to 5, 3, and 8 keV, respectively, using the SAMMY code for a full R-matrix fit of the capture yields. From these results average resonance parameters were derived by a

K. Fujii; Paul Edward Koehler; A. Mengoni; C. Domingo-Pardo; F. Käppeler; U. Abbondanno; G. Aerts; H. Álvarez-Pol; F. Alvarez-Velarde; S. Andriamonje; J. Andrzejewski; P. Assimakopoulos; L. Audouin; G. Badurek; P. Baumann; F. Be?vá?; F. Belloni; E. Berthoumieux; S. Bisterzo; M. Calviani; F. Calviño; D. Cano-Ott; R. Capote; A. Carrillo de Albornoz; P. Cennini; V. Chepel; E. Chiaveri; N. Colonna; G. Cortes; A. Couture; J. Cox; M. Dahlfors; S. David; I. Dillmann; R. Dolfini; W. Dridi; I. Duran; C. Eleftheriadis; M. Embid-Segura; L. Ferrant; A. Ferrari; R. Ferreira-Marques; L. Fitzpatrick; H. Frais-Koelbl; W. Furman; R. Gallino; I. Goncalves; E. Gonzalez-Romero; A. Goverdovski; F. Gramegna; E. Griesmayer; C. Guerrero; F. Gunsing; B. Haas; R. Haight; M. Heil; A. Herrera-Martinez; M. Igashira; S. Isaev; E. Jericha; Y. Kadi; D. Karamanis; D. Karadimos; M. Kerveno; V. Ketlerov; V. Konovalov; E. Kossionides; M. Krti?ka; C. Lamboudis; H. Leeb; A. Lindote; I. Lopes; M. Lozano; S. Lukic; J. Marganiec; L. Marques; S. Marrone; C. Massimi; P. Mastinu; P. Milazzo; C. Moreau; F. Neves; H. Oberhummer; M. Oshima; S. O’Brien; J. Pancin; C. Papachristodoulou; C. Papadopoulos; C. Paradela; N. Patronis; A. Pavlik; P. Pavlopoulos; L. Perrot; R. Plag; A. Plompen; A. Plukis; A. Poch; J. Praena; C. Pretel; J. Quesada; T. Rauscher; R. Reifarth; M. Rosetti; C. Rubbia; G. Rudolf; P. Rullhusen; J. Salgado; L. Sarchiapone; I. Savvidis; C. Stephan; G. Tagliente; J. Tain; L. Tassan-Got; L. Tavora; R. Terlizzi; G. Vannini; P. Vaz; A. Ventura; D. Villamarin; M. Vincente; V. Vlachoudis; R. Vlastou; F. Voss; S. Walter; H. Wendler; M. Wiescher; K. Wisshak

2010-01-01

326

Introduction to DNA Extractions  

NSDL National Science Digital Library

This lab exercise, authored by Lana Hays of Access Excellence at the National Health Museum, giving instructions for the extraction of DNA from several different starting materials. The lab employs everyday material which can be found at your local grocery store. The exercise is designed for the 6-12 grade level.

Hays, Lana

2009-11-04

327

SOLVENT EXTRACTION TREATMENT  

EPA Science Inventory

Solvent extraction does not destroy wastes, but is a means of separating hazardous contaminants from soils, sludges, and sediments, thereby reducing the volume of the hazardous waste that must be treated. enerally it is used as one ina series of unit operations, and can reduce th...

328

Resonant microwave cavity for 8.512 GHz optically detected electron spin resonance with simultaneous nuclear magnetic resonance  

E-print Network

Resonant microwave cavity for 8.5­12 GHz optically detected electron spin resonance with simultaneous nuclear magnetic resonance J. S. Colton1,a and L. R. Wienkes2 1 Department of Physics online 16 March 2009 We present a newly developed microwave resonant cavity for use in optically detected

Hart, Gus

329

Electric Oxygen-Iodine Laser Performance Enhancement using Larger Discharge and Resonator Mode Volumes  

E-print Network

Electric Oxygen-Iodine Laser Performance Enhancement using Larger Discharge and Resonator Mode that significantly higher power was available in the electric oxygen-iodine laser gas flow which could be extracted length of the laser cavity, plus the addition of an iodine pre-dissociator discharge are expected

Carroll, David L.

330

Multinuclear Magnetic Resonance Analysis of Two Humic Acid Fractions from Lowland Rice Soils  

E-print Network

to the mobile humic acid (MHA) and calcium and 15 N and solution 31 P nuclear magnetic resonance (NMR) spectros- humate (CaHA) fractions extracted from 12 soils with copy to analyze the labile mobile humic acid (MHA ourof less humified material in the MHA and CaHA, such as diester phosphorus (P), amide nitrogen (N

Hemminga, Marcus A.

331

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

332

A primer for resonant tunnelling  

E-print Network

Resonant tunnelling is studied numerically and analytically with the help of a three-well quantum one-dimensional time-independent model. The simplest cases are considered where the three-well potential is polynomial or piecewise constant.

Jérémy Le Deunff; Olivier Brodier; Amaury Mouchet

2012-07-27

333

Magnetic resonance angiogram and imaging.  

PubMed

Reports from specialized medical tests may often reveal findings that are ambiguous. In this article, the significance of punctate signal changes and ischemia revealed by magnetic resonance scanning are discussed. PMID:15912911

Goodwin, L

2000-01-01

334

Distribution of neutron resonance widths  

E-print Network

Recent data on neutron resonance widths indicate disagreement with the Porter-Thomas distribution (PTD). I discuss the theoretical arguments for the PTD, possible theoretical modifications, and I summarize the experimantal evidence.

Weidenmueller, Hans A

2011-01-01

335

Distribution of neutron resonance widths  

E-print Network

Recent data on neutron resonance widths indicate disagreement with the Porter-Thomas distribution (PTD). I discuss the theoretical arguments for the PTD, possible theoretical modifications, and I summarize the experimantal evidence.

Hans A. Weidenmueller

2011-10-28

336

Distribution of Neutron Resonance Widths  

NASA Astrophysics Data System (ADS)

Recent data on neutron resonance widths indicate disagreement with the Porter-Thomas distribution (PTD). I discuss the theoretical arguments for the PTD, possible theoretical modifications, and I summarize the experimental evidence.

Weidenmüller, Hans A.

2013-03-01

337

Nuclear magnetic resonance readable sensors  

E-print Network

The monitoring of physiological biomarkers is fundamental to the diagnosis and treatment of disease. We describe here the development of molecular sensors which can be read by magnetic resonance (MR) relaxometry. MR is an ...

Ling, Yibo

2010-01-01

338

The mechanism of stochastic resonance  

Microsoft Academic Search

It is shown that a dynamical system subject to both periodic forcing and random perturbation may show a resonance (peak in the power spectrum) which is absent when either the forcing or the perturbation is absent.

R. Benzi; A. Sutera; A. Vulpiani

1981-01-01

339

Matryoshka Locally Resonant Sonic Crystal  

Microsoft Academic Search

The results of numerical modelling of sonic crystals with resonant array\\u000aelements are reported. The investigated resonant elements include plain slotted\\u000acylinders as well as various their combinations, in particular, Russian doll or\\u000aMatryoshka configurations. The acoustic band structure and transmission\\u000acharacteristics of such systems have been computed with the use of finite\\u000aelement methods. The general concept of a

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

2011-01-01

340

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

341

vhf Pulsed Magnetic Resonance Duplexers  

Microsoft Academic Search

Coupling schemes for pulsed magnetic resonance spectrometers operating in the vhf region are discussed. Three such schemes are described in detail and their performances compared, using the 81Br nuclear quadrupole resonance signal at ?200 MHz in polycrystalline K2PtBr6. The first scheme employs a hybrid T, coaxial ring circuit with the transmitter, receiver, sample coil, and a dummy load in the

B. Michael Moores; Robin L. Armstrong

1971-01-01

342

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

343

Surface Plasmon Resonance Evaluation of Colloidal Metal Aerogel Filters  

NASA Technical Reports Server (NTRS)

Surface plasmon resonance imaging has in the past been applied to the characterization of thin films. In this study we apply the surface plasmon technique not to determine macroscopic spatial variations but rather to determine average microscopic information. Specifically, we deduce the dielectric properties of the surrounding gel matrix and information concerning the dynamics of the gelation process from the visible absorption characteristics of colloidal metal nanoparticles contained in aerogel pores. We have fabricated aerogels containing gold and silver nanoparticles. Because the dielectric constant of the metal particles is linked to that of the host matrix at the surface plasmon resonance, any change 'in the dielectric constant of the material surrounding the metal nanoparticles results in a shift in the surface plasmon wavelength. During gelation the surface plasmon resonance shifts to the red as the average or effective dielectric constant of the matrix increases. Conversely, formation of an aerogel or xerogel through supercritical extraction or evaporation of the solvent produces a blue shift in the resonance indicating a decrease in the dielectric constant of the matrix. From the magnitude of this shift we deduce the average fraction of air and of silica in contact with the metal particles. The surface area of metal available for catalytic gas reaction may thus be determined.

Smith, David D.; Sibille, Laurent; Cronise, Raymond J.; Noever, David A.

1997-01-01

344

Evolution of the pygmy dipole resonance in Sn isotopes  

E-print Network

Nuclear level density and $\\gamma$-ray strength functions of $^{121,122}$Sn below the neutron separation energy are extracted with the Oslo method using the ($^3$He,$^3$He$^\\prime\\gamma$) and ($^3$He,$\\alpha \\gamma$) reactions. The level densities of $^{121,122}$Sn display step-like structures, interpreted as signatures of neutron pair breaking. An enhancement in both strength functions, compared to standard models for radiative strength, is observed in our measurements for $E_\\gamma \\gtrsim 5.2 $ MeV. This enhancement is compatible with pygmy resonances centered at $\\approx 8.4(1)$ and $\\approx 8.6(2)$ MeV, respectively, and with integrated strengths corresponding to $\\approx1.8^{+1}_{-5}%$ of the classical Thomas-Reiche-Kuhn sum rule. Similar resonances were also seen in $^{116-119}$Sn. Experimental neutron-capture cross reactions are well reproduced by our pygmy resonance predictions, while standard strength models are less successful. The evolution as a function of neutron number of the pygmy resonance in $^{116-122}$Sn is described as a clear increase of centroid energy from 8.0(1) to 8.6(2) MeV, but with no observable difference in integrated strengths.

H. K. Toft; A. C. Larsen; A. Bürger; M. Guttormsen; A. Görgen; H. T. Nyhus; T. Renstrøm; S. Siem; G. M. Tveten; A. Voinov

2011-05-18

345

Acoustic resonance scattering from a submerged anisotropic sphere  

NASA Astrophysics Data System (ADS)

The resonance scattering theory (RST) is applied to the problem of sound scattering from an elastic transversely isotropic solid sphere suspended in an ideal acoustic fluid medium. The normal mode expansion technique in conjunction with the Frobenius power series solution method is utilized to deal with the material anisotropy. The presented model, which degenerates to the simple isotropic solution in the case of very weak anisotropy, is initially employed to study sensitivity of various resonant modes of vibration to perturbations in elements of the stiffness matrix. Employing a rigid background subtraction, the target’s spectrum of resonances is extracted from the relevant modal backscattering form functions and subsequently traced and discussed through Regge pole trajectory plots. Also, the backscattering form function and resonance spectra, along with the dispersion curves for selected transversely isotropic solid spheres with distinct degrees of material anisotropy, are calculated and discussed. The various modes of propagation associated with the Rayleigh, Whispering Gallery, and fluid-borne Scholte-Stoneley surface waves are identified and examined.

Hasheminejad, S. M.; Maleki, M.

2008-03-01

346

Modeling and simulation of two-step resonance ionization processes using CW and pulsed lasers  

E-print Network

This thesis derives and discusses equations that describe the evolution of atomic systems subjected to two monochromatic and coherent radiation fields and treats both continuous and temporally pulsed irradiation. This theoretical description is de- veloped mainly to understand the influence of the photon field intensities on experimental ionization spectra. The primary ap- plication of this theoretical framework is on methods that rely on resonant laser excitation and non-resonant laser ionization to extract information on the hyperfine structure of atomic systems. In particular, qualitative and quantitative discussions on the laser-related changes in hyperfine splitting extracted from ion- ization spectra are presented. Also, a method for increasing the resolution of resonance ionization techniques (potentially up un- til the natural linewidth of the electronic transitions) is discussed and theoretically justified. Both topics are illustrated with exper- imental data.

de Groote, Ruben; Flanagan, Kieran

347

Stochastic resonance with matched filtering  

E-print Network

Along with the development of interferometric gravitational wave detector, we enter into an epoch of gravitational wave astronomy, which will open a brand new window for astrophysics to observe our universe. Almost all of the data analysis methods in gravitational wave detection are based on matched filtering. Gravitational wave detection is a typical example of weak signal detection, and this weak signal is buried in strong instrument noise. So it seems attractable if we can take advantage of stochastic resonance. But unfortunately, almost all of the stochastic resonance theory is based on Fourier transformation and has no relation to matched filtering. In this paper we try to relate stochastic resonance to matched filtering. Our results show that stochastic resonance can indeed be combined with matched filtering for both periodic and non-periodic input signal. This encouraging result will be the first step to apply stochastic resonance to matched filtering in gravitational wave detection. In addition, based on matched filtering, we firstly proposed a novel measurement method for stochastic resonance which is valid for both periodic and non-periodic driven signal.

Li-Fang Li; Jian-Yang Zhu

2010-06-28

348

Real time electromagnetic target classification using a novel feature extraction technique with PCA-based fusion  

Microsoft Academic Search

This work introduces an efficient technique to design an electromagnetic target classifier whose reference database is constructed using scattered data at only a few aspects. The suggested technique combines a natural-resonance related feature extraction process with a novel, multiaspect feature fusion scheme. First, moderately aspect-variant late-time features are extracted from scattered field of a given candidate target at several different

Gönül Turhan-Sayan

2005-01-01

349

The Design of the New Fast Extraction Channel for the LHC  

E-print Network

The Large Hadron Collider (LHC) project requires the modification of the existing extraction channel in the long straight section 6 of the CERN Super Proton Synchrotron (SPS). The new extraction will be used to transfer protons at 450 GeV/c as well as ions via the 2.8 km long transfer line TI 2 to the clockwise ring of the LHC. As the resonant extraction to the present SPS West Area will be stopped after 2004, the electrostatic septa will be replaced by new fast extraction kicker magnets. The girder for the existing DC septa will be modified to accommodate a new septum protection element. Other modifications concern the replacement of a machine quadrupole, a new scheme for the extraction bumpers, new instrumentation and interlocks. The requirements and the design of the new extraction channel will be described as well as the modifications which will mainly be carried out in the long SPS shutdown 2005.

Borburgh, J; Gaxiola, E; Goddard, B; Kadi, Y; Uythoven, J

2004-01-01

350

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

351

Ghost-vibrational resonance S. Rajamani a  

E-print Network

Ghost-vibrational resonance S. Rajamani a , S. Rajasekar a, , M.A.F. Sanjuán b a School of Physics Keywords: Ghost resonance Multi-frequency signal Duffing oscillator a b s t r a c t Ghost-stochastic resonance is a noise-induced resonance at a fundamental frequency miss- ing in the input signal. We

Rey Juan Carlos, Universidad

352

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

353

Backscattering suppression in nonreciprocal ring resonators  

NASA Astrophysics Data System (ADS)

Faraday effect in ring resonators leads to the resonance splitting of clockwise and counter-clockwise propagating modes. Thus the backscattering into counter propagating mode of the ring resonator due to the roughness or periodical corrugation of the ring side walls can be suppressed by the Faraday effect. Based on that property, we propose here a novel ring resonator switch. The resonance of the corrugated resonator coupled to a waveguide can be switched off by the application of the external magnetic field. In this case, the resonance is not shifted, as what typically occurs at small perturbation, but suppressed.

Petrov, Alexander Yu.; Jalas, Dirk; Krause, Michael; Eich, Manfred

2010-10-01

354

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

355

Extracting tag hierarchies  

E-print Network

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 betwe...

Tibély, Gergely; Vicsek, Tamás; Palla, Gergely

2014-01-01

356

[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

357

Follicular unit extraction.  

PubMed

The purpose of this article is to introduce the reader to the topic of follicular unit extraction (FUE) and to present an overview of the value of FUE to patients and physicians. In addition to this, the various methods and instrumentation for performing this method of graft harvest are discussed as well as some of the technique's inherent advantages and disadvantages. Topics unique to FUE, including body hair grafting, plug/minigrafts repair, and donor area management are addressed as well. PMID:24017979

Harris, James A

2013-08-01

358

MAGNETIC RESONANCE IN CHEMISTRY Magn. Reson. Chem. 2006; 44: S206S212  

E-print Network

MAGNETIC RESONANCE IN CHEMISTRY Magn. Reson. Chem. 2006; 44: S206�S212 Published online in Wiley 16 March 2006 Sample concentrations can be measured by nuclear magnetic resonance (NMR) spectroscopy contains a resolved resonance; but can also be applied to spectral regions with overlapping resonances

Wider, Gerhard

359

Stochastic Resonance: from climate to biology  

E-print Network

In this paper I will review some basic aspects of the mechanism of stochastic resonance. Stochastic resonance was first introduced as a possible mechanism to explain long term climatic variation. Since then, there have been many applications of stochastic resonance in physical and biological systems. I will show that in complex system, stochastic resonance can substantially change as a function of the ``system complexity''. Also, I will briefly mention how to apply stochastic resonance for the case of Brownian motors.

Roberto Benzi

2007-02-05

360

Ancient DNA extraction from plants.  

PubMed

A variety of protocols for DNA extraction from archaeological and paleobotanical plant specimens have been proposed. This is not surprising given the range of taxa and tissue types that may be preserved and the variety of conditions in which that preservation may take place. Commercially available DNA extraction kits can be used to recover ancient plant DNA, but modifications to standard approaches are often necessary to improve yield. In this chapter, I describe two protocols for extracting DNA from small amounts of ancient plant tissue. The CTAB protocol, which I recommend for use with single seeds, utilizes an incubation period in extraction buffer and subsequent chloroform extraction followed by DNA purification and suspension. The PTB protocol, which I recommend for use with gourd rind and similar tissues, utilizes an overnight incubation of pulverized tissue in extraction buffer, removal of the tissue by centrifugation, and DNA extraction from the buffer using commercial plant DNA extraction kits. PMID:22237524

Kistler, Logan

2012-01-01

361

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

362

Giant Quadrupole and Monopole Resonances in Si-28  

E-print Network

including zero degrees. A total of 66% of the EO energy-weighted sum rule was identified (using a Satchler version 2 form factor) centered at E?=17.9 MeV having a width of 4.8 MeV and 34% of the E2 energy-weighted sum rule was identified above E = 15.3 Me...V centered at 19.0 MeV with a width of 4.4 MeV. The dependence of the extracted EO strength on form factor and optical potential was ex- plored. INTRODUCTION The properties of the giant monopole resonance (GMR) are of particular importance because...

Lui, YW; Bronson, J. D.; Youngblood, David H.; Toba, Y.; Garg, U.

1985-01-01

363

Neural network diagnosis of avascular necrosis from magnetic resonance images  

NASA Astrophysics Data System (ADS)

We have explored the use of artificial neural networks to diagnose avascular necrosis (AVN) of the femoral head from magnetic resonance images. We have developed multi-layer perceptron networks, trained with conjugate gradient optimization, which diagnose AVN from single sagittal images of the femoral head with 100% accuracy on the training data and 97% accuracy on test data. These networks use only the raw image as input (with minimal preprocessing to average the images down to 32 X 32 size and to scale the input data values) and learn to extract their own features for the diagnosis decision. Various experiments with these networks are described.

Manduca, Armando; Christy, Paul S.; Ehman, Richard L.

1993-09-01

364

Resonances in Coupled ? K -? K Scattering from Quantum Chromodynamics  

NASA Astrophysics Data System (ADS)

Using a first-principles calculation within quantum chromodynamics, we are able to determine a pattern of strangeness=1 resonances that appear as complex singularities within coupled ? K -? K scattering amplitudes. We make use of numerical computation in the lattice discretized approach to the quantum field theory with light quark masses corresponding to m?˜400 MeV and at a single lattice spacing. The energy dependence of scattering amplitudes is extracted through their relationship to the discrete spectrum in a finite volume, which we map out in unprecedented detail.

Dudek, Jozef J.; Edwards, Robert G.; Thomas, Christopher E.; Wilson, David J.; Hadron Spectrum Collaboration

2014-10-01

365

Coupling of a locally implanted rare-earth ion ensemble to a superconducting micro-resonator  

NASA Astrophysics Data System (ADS)

We demonstrate the coupling of rare-earth ions locally implanted in a substrate (Gd3+ in Al2O3) to a superconducting NbN lumped-element micro-resonator. The hybrid device is fabricated by a controlled ion implantation of rare-earth ions in well-defined micron-sized areas, aligned to lithographically defined micro-resonators. The technique does not degrade the internal quality factor of the resonators which remain above 105. Using microwave absorption spectroscopy, we observe electron-spin resonances in good agreement with numerical modelling and extract corresponding coupling rates of the order of 1 MHz and spin linewidths of 50-65 MHz.

Wisby, I.; de Graaf, S. E.; Gwilliam, R.; Adamyan, A.; Kubatkin, S. E.; Meeson, P. J.; Tzalenchuk, A. Ya.; Lindström, T.

2014-09-01

366

Green's function method for single-particle resonant states in relativistic mean field theory  

E-print Network

Relativistic mean field theory is formulated with the Green's function method in coordinate space to investigate the single-particle bound states and resonant states on the same footing. Taking the density of states for free particle as a reference, the energies and widths of single-particle resonant states are extracted from the density of states without any ambiguity. As an example, the energies and widths for single-neutron resonant states in $^{120}$Sn are compared with those obtained by the scattering phase-shift method, the analytic continuation in the coupling constant approach, the real stabilization method and the complex scaling method. Excellent agreements are found for the energies and widths of single-neutron resonant states.

T. T. Sun; S. Q. Zhang; Y. Zhang; J. N. Hu; J. Meng

2014-09-30

367

Extraction chemistry of some bidentate organophosphorus compounds  

Microsoft Academic Search

The extraction chemistry of methylenediphosphonates, carbamoylphosphonates, and carbamoylmethylenephosphonates has been investigated. The bidentate organophosphorus compounds extract actinides strongly, extract lanthanides, iron, gallium, molybdenum, titanium, vanadium, and zirconium partially, and do not extract most other elements from 5 to 7 M nitric acid. The properties of the extractants and extraction mechanisms are discussed. The effect of complexing agents on the extraction

L. L. Martella; J. D. Navratil; W. F. Santiago

1978-01-01

368

Lattice QCD Evidence for Exotic Tetraquark Resonance  

E-print Network

We study the manifestly exotic tetraquark D$_{\\rm s0}^{++}(cu\\bar s \\bar d)$ and the scalar tetraquark $f_0(ud \\bar u \\bar d)$ in SU(3)$_c$ anisotropic quenched lattice QCD with the $O(a)$-improved Wilson (clover) fermion with various quark masses including the idealized SU(4)$_f$ case. For $f_0(ud\\bar u \\bar d)$ etc., we only consider connected diagrams at the quenched level, i.e., the tetraquark $f_0(ud\\bar u\\bar d)$ is identical with D$_{\\rm s0}^{++} (cu\\bar s \\bar d)$ in the idealized SU(4)$_f$ case. First, for comparison, we study the lowest $q\\bar q$ scalar meson, and find that it has a large mass of about 1.37GeV after chiral extrapolation, which corresponds to $f_0(1370)$. Second, we investigate the lowest 4Q state in the spatial periodic boundary condition, and find that it is just a scattering state of two pseudoscalar mesons, as is expected. Third, to extract spatially-localized 4Q resonances, we use the Hybrid Boundary Condition (HBC) method, where anti-periodic and periodic boundary conditions are imposed on quarks ($c$,$u$) and antiquarks ($\\bar s$,$\\bar d$), respectively. By applying the HBC on a finite-volume lattice, the threshold of the two-meson scattering state is raised up, while the mass of a compact 4Q resonance is almost unchanged. In HBC, we find a nontrivial 4Q resonance state about 100 MeV below the two-meson threshold in some quark-mass region. Its chiral behavior largely differs from a two-meson scattering state. The scalar tetraquark $f_0(ud\\bar u\\bar d)$ is found to have the mass of about 1.1GeV after chiral extrapolation, and seems to correspond to $f_0(980)$. Then, the manifestly exotic tetraquark D$_{\\rm s0}^{++}(cu\\bar s \\bar d)$ would exist around 1GeV in the idealized SU(4)$_f$ chiral limit. Finally, MEM analysis is applied to obtain the spectral function of the 4Q system.

Hideo Suganuma; Kyosuke Tsumura; Noriyoshi Ishii; Fumiko Okiharu

2005-09-26

369

Energy dissipation in micromechanical resonators  

NASA Astrophysics Data System (ADS)

Recent years have witnessed breakthrough researches in micro- and nano-mechanical resonators with small dissipation. Nano-precision micromachining has enabled the realization of integrated micromechanical resonators with record high Q and high frequency, creating new research horizons. Not too long ago, there was a perception in the MEMS community that the maximum f.Q product of a microresonator is limited to a frequency-independent constant determined by the material properties of the resonator. In this paper, the contribution of phonon interactions in determining the upper limit of f.Q product in micromechanical resonators will be discussed and shown that after certain frequency, the f.Q product is no longer constant but a linear function of frequency. This makes it possible to reach very high Qs in GHz micro- and nano-mechanical resonators and filters. Contributions of other dissipation mechanisms such as thermoelastic damping and support loss in the quality factor of a microresonator will be discussed as well.

Ayazi, Farrokh; Sorenson, Logan; Tabrizian, Roozbeh

2011-06-01

370

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

371

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.

372

Transmission resonances in the bipolar quantum resonant tunneling transistor  

E-print Network

?? (20) where a is the slope and n = 1, 2, . . . The energy at the top of a finite well with slope o and width Lw is E?= oLw. If we then approximate E?by the infinite well result (20), 34 the condition for a resonance, or expression for the slope as a... ?? (20) where a is the slope and n = 1, 2, . . . The energy at the top of a finite well with slope o and width Lw is E?= oLw. If we then approximate E?by the infinite well result (20), 34 the condition for a resonance, or expression for the slope as a...

Mondragon, Antonio Richard

2012-06-07

373

Resonance production by neutrinos: I. J=3/2 Resonances  

E-print Network

The article contains general formulas for the production of J=3/2 resonances by neutrinos and antineutrinos. It specializes to the P_{33}(1232) resonance whose form factors are determined by theory and experiment and then are compared with experimental results at low and high energies. It is shown that the minimum in the low Q^2 region is a consequence of a combined effect from the vanishing of the vector form factors, the muon mass and Pauli blocking. Several improvements for the future investigations are suggested.

Olga Lalakulich; Emmanuel A. Paschos

2005-01-13

374

Resonant Frequency Characteristics of a SAW Device Attached to Resonating Micropillars  

PubMed Central

Recently we reported experimental and simulation results on an increase in resonance frequency of a SAW resonator caused by mass loading of micropillars made of SU-8, attached normal to the surface of the resonator. We concluded that SAW resonator and the SU-8 micropillars in unison form a system of coupled resonators. We have now extended this work and performed a finite element method simulation to study the resonance frequency characteristics of the SAW-based coupled resonator. In this paper we report the effect of the resonance frequency of the micropillars on the resonance frequency of the system of coupled resonators, and observe the coupling of micropillar resonance and the propagating SAW as described in the well known Dybwad system of coupled resonators. PMID:22666001

Ramakrishnan, N.; Nemade, Harshal B.; Palathinkal, Roy Paily

2012-01-01

375

?-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

376

Radiation losses in resonant tubes  

NASA Technical Reports Server (NTRS)

The role of radiation losses in a resonant tube - the transfer of sound energy from the test gas through the confines of the tube to the ambient atmosphere - is investigated both theoretically and experimentally. It is concluded that losses of this sort make no noticeable contribution to the background losses, even at high gas pressures. Nevertheless, if an axial resonant frequency of the test gas closely matches a longitudinal resonant frequency of the tube wall, the internal sound pressure can excite tube displacements of disproportionate magnitude and thus cause excessive losses, not due to radiation but rather to frictional dissipation related to the motion of the tube structure. This mechanism is effective when the mode numbers of the gas and tube have opposite parity, and makes sound absorption measurements at the fundamental gas frequency particularly problematical. An experimental investigation confirms the existence of such additional losses when the parity condition is fulfilled.

Zuckerwar, A. J.; Meredith, R. W.

1981-01-01

377

Structural Colors from Fano Resonances  

E-print Network

Structural coloration is an interference phenomenon where colors emerge when visible light interacts with nanoscopically structured material, and has recently become a most interesting scientific and engineering topic. However, current structural color generation mechanisms either require thick (compared to the wavelength) structures or lack dynamic tunability. This report proposes a new structural color generation mechanism, that produces colors by the Fano resonance effect on thin photonic crystal slab. We experimentally realize the proposed idea by fabricating the samples that show resonance-induced colors with weak dependence on the viewing angle. Finally, we show that the resonance-induced colors can be dynamically tuned by stretching the photonic crystal slab fabricated on an elastic substrate.

Shen, Yichen; Wang, Imbert; Stelmakh, Veronika; Joannopoulos, John D; Soljacic, Marin

2014-01-01

378

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

379

Proton NMR Spectroscopic Studies on Tissue Extracts of Invertebrate Species with Pollution Indicator Potential  

Microsoft Academic Search

High resolution proton nuclear magnetic resonance (1H NMR) spectroscopic methods have been used to characterise tissue extracts of a series of common British invertebrate species with pollution indicator potential. These include two earthworm species Lumbricus rubellus (Hoffmeister) and Eisenia andrei (Savigny), two terrestrial isopods, Oniscus asellus (L.) and Porcellio scaber (Latreille), the diplopodous arthropod, Glomeris marginata (Villers) and a pulmonate

J. O. T Gibb; E Holmes; J. K Nicholson

1997-01-01

380

Comprehensive evaluation of neuroprotective effects of Ginkgo biloba extract EGB against ischemic stroke  

Microsoft Academic Search

EGb761 is a standard extract of Ginkgo biloba, which is a kind of traditional Chinese herbs that has widely used in clinic treatment of stroke in China. However, its effects against ischemic stroke have not been evaluated comprehensively and its neuroprotective mechanism has not really been explored. In the present study, magnetic resonance diffusion-weighted imaging (DWI), neurological behavior and TTC

Zhanjun Zhang; Dantao Peng; Haiyan Zhu; Xiaomin Wang

381

Statistical feature extraction for artifact removal from concurrent fMRI-EEG recordings  

Microsoft Academic Search

We propose a set of algorithms for sequentially removing artifacts related to MRI gradient switching and cardiac pulsations from electroencephalography (EEG) data recorded during functional magnetic resonance imaging (fMRI). Special emphasis is directed upon the use of statistical metrics and methods for the extraction and selection of features that characterize gradient and pulse artifacts. To remove gradient artifacts, we use

Zhongming Liu; Jacco A. de Zwart; Peter van Gelderen; Li-Wei Kuo; Jeff H. Duyn

382

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

383

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. PMID:24391901

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

2013-01-01

384

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. PMID:23939460

Kang, Ji-Hun; -Han Park, Q.

2013-01-01

385

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

386

Elastic scattering of Al25+p to explore the resonance structure in Si26  

NASA Astrophysics Data System (ADS)

Background: The properties of resonances in Si26 are important to better constrain the Al25(p,?)Si26 reaction rate relevant to the synthesis of galactic Al26gs and energy generation in explosive stellar environment at higher temperature. Purpose: Al25+p elastic scattering was measured to further constrain and investigate disagreements in resonance parameters for the high-lying excited states of Si26 with high statistics and without background contamination within the target. Methods: The experiment was performed by bombarding a thick H2 target with an Al25 radioactive ion beam. The resonances at excitation energies of 6.6-8.3 MeV in the Si26 compound nucleus were studied at the low-energy radioactive-ion beam facility CRIB (Center for Nuclear Study Radioactive Ion Beam separator) at the University of Tokyo. Results: Six resonant states were observed and their resonance parameters were extracted by an R-matrix analysis. Our resonance parameters for two levels are in good agreement with the results of previous studies, while for four others, excitation energy, proton partial width, and spin-parity assignment disagree with the results of recent study via elastic scattering of Al25+p. Conclusion: The parameters of resonant states in Si26 determined in the present work for the Al25(p,?)Si26 reaction rate are consistent with that of the previous result, solving spin-parity assignment discrepancies between experiments, relevant at higher temperatures.

Jung, H. S.; Lee, C. S.; Kwon, Y. K.; Moon, J. Y.; Lee, J. H.; Yun, C. C.; Kim, M. J.; Hashimoto, T.; Yamaguchi, H.; Kahl, D.; Kubono, S.; Wakabayashi, Y.; Togano, Y.; Choi, Seonho; Kim, Y. H.; Kim, Y. K.; Park, J. S.; Kim, E. J.; Moon, C.-B.; Teranishi, T.; Iwasa, N.; Yamada, T.; Kato, S.; Cherubini, S.; Hayakawa, S.; Rapisarda, G. G.

2014-09-01

387

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

388

Kozai resonance in extrasolar systems  

NASA Astrophysics Data System (ADS)

Aims: We study the possibility that extrasolar two-planet systems, similar to the ones that are observed, can be in a stable Kozai-resonant state, assuming a mutual inclination of the orbital planes of order I_mut˜ 40-60°. Methods: Five known multi-planet systems that are not in mean motion resonance were selected, according to defined criteria, as “possible prototypes” (? Andromedae, HD 12661, HD 169830, HD 74156, HD 155358). We performed a parametric study, integrating several sets of orbits of the two planets, obtained by varying the (unknown) inclination of their orbital planes and their nodal longitudes, thus changing the values of their masses and mutual inclination. We also take into account the reported observational errors on the orbital elements. These numerical results are characterized using analytical secular theory and frequency analysis. Surface of section techniques are also used to distinguish between stable and chaotic motions. Results: Frequency analysis offers a reliable way of identifying the Kozai resonance in a general reference frame, where the argument of the pericenter of the inner planet does not necessarily librate around ±90° as in the frame of the Laplace plane, through the non-coupling of the eccentricities of the two planets. We find that four of the five selected systems (? Andromedae, HD 12661, HD 169830 and HD 74156) could in principle be in Kozai resonance, as their eccentricities and apsidal orientations are such that the system enters in the stability region of the Kozai resonance in 20-70% of the cases, provided that their mutual inclination is at least 45°. Thus, a large fraction of the observed multi-planet systems has observed orbital characteristics that are consistent with stable, Kozai-type, motion in 3D. Unstable sets of orbits are also found, due to the chaos that develops around the stability islands of the Kozai resonance. A variety of physical mechanisms that could generate the necessary large mutual inclinations are discussed, including (a) planet formation; (b) type II migration and resonant interactions during the gas-dominated phase; (c) planetesimal-driven migration and resonance crossing during the gas-free era; (d) multi-planet scattering, caused by the presence of an additional planet.

Libert, A.-S.; Tsiganis, K.

2009-01-01

389

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

390

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

391

Coronary sinus lead extraction.  

PubMed

Complications are reported more frequently with the implantation of coronary sinus (CS) than other types of leads, and attempts to extract CS leads may also be associated with increased risks. The authors have performed nonthoracotomy lead extraction (LE) since 1981 and maintained a detailed database. By November 2001, 796 leads had been removed from 401 patients. We undertook review of our CS-LE experience to evaluate prevalence, safety, and efficacy. Of 14 patients referred for CS-LE, 7 were treated in the last year. In six the lead had been placed in the CS intentionally, and in eight inadvertently. One recent patient treated with biventricular pacing was septic and died before LE was undertaken. In nine men and four women (mean age 66 years) had one each CS lead and a total of 34 LEs (2.6/patient). Four CS leads had been in place for < 6 months (mean 1.5 month), whereas nine had been in place for between 6 months and 27 years. Several LE methods were used, from simple traction to the use of intraluminal locking stylets and powered sheaths. Complete removal of all leads was achieved in all patients. CS-LE required a mean of 13 minutes, including 1.8 minutes of fluoroscopy. There were no serious complications during the procedures, and the mean hospital stay was 4 days. PMID:12687883

Tyers, G Frank O; Clark, Jacquie; Wang, Yan; Mills, Pauline; Bashir, Jamil

2003-01-01

392

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

393

NDI using mm-wave resonant techniques  

SciTech Connect

Millimeter wave resonant measurements are commonly used for surface and near-surface materials characterization including the detection of cracks and defects, analysis of semiconducting and dielectric materials, and analysis of metallic electrical properties beneath coatings. Recent work has also shown the approach to be useful in evaluating corrosion products and the detection of incipient corrosion and corrosion cracking. In the analysis area, complex permittivity data of the corrosion products can be extracted, usually with accuracy of a few percent or better, to aid in identification of the product and possibly of mechanisms. In the detection area, corrosion-related cracks of order 100{mu}m or less near the surface have been detected and corrosion products have been detected beneath a variety of paints. Surface preparation requirements are minimal, particularly compared to some optical techniques, giving increased hope of field applicability. A number of examples of NDI on aircraft related materials and structures will be presented along with an assessment of detection and accuracy limits.

Martens, J.S.; Sachtjen, S. [Conductus, Inc. (United States); Sorensen, N.R. [Sandia National Labs., Albuquerque, NM (United States)

1995-08-01

394

Double-Grating Displacement Structure for Improving the Light Extraction Efficiency of LEDs  

PubMed Central

To improve the light extraction efficiency of light-emitting diodes (LEDs), grating patterns were etched on GaN and silver film surfaces. The grating-patterned surface etching enabled the establishment of an LED model with a double-grating displacement structure that is based on the surface plasmon resonance principle. A numerical simulation was conducted using the finite difference time domain method. The influence of different grating periods for GaN surface and silver film thickness on light extraction efficiency was analyzed. The light extraction efficiency of LEDs was highest when the grating period satisfied grating coupling conditions. The wavelength of the highest value was also close to the light wavelength of the medium. The plasmon resonance frequencies on both sides of the silver film were affected by silver film thickness. With increasing film thickness, plasmon resonance frequency tended toward the same value and light extraction efficiency reached its maximum. When the grating period for the GaN surface was 365 nm and the silver film thickness was 390 nm, light extraction efficiency reached a maximum of 55%. PMID:23118613

Wang, Zhibin; Hao, Yang; Wang, Zhongdong; Liu, Xian; Zhang, Qian; Zhu, Dandan

2012-01-01

395

Magnetic Resonance Imaging of concrete  

E-print Network

1 Magnetic Resonance Imaging of concrete Dr Chris Burgoyne Department of Engineering University of Cambridge Assessment of Concrete Structures · How can we tell what is going on inside concrete? · We would like to know:- · Has the concrete hardened? · Is there corrosion? · Is there cracking? · Where

Burgoyne, Chris

396

Quantum dot resonant tunneling spectroscopy  

NASA Astrophysics Data System (ADS)

The electronic transport through 3-dimensionally confined semiconductor quantum wells (quantum dots) is investigated and analyzed. The spectra corresponds to resonant tunneling from laterally-confined emitter contact subbands through the discrete 3-dimensionally confined quantum dot states. Momentum nonconservation is observed in these structures. Results on coupled quantum dot states (molccules) will be presented.

Reed, Mark A.; Randall, John N.; Luscombe, James H.; Frensley, William R.; Aggarwal, Raj J.; Matyi, Richard J.; Moore, Tom M.; Wetsel, Anna E.

397

Trends in resonance ionization spectroscopy  

SciTech Connect

The author reviews the history of resonance ionization spectroscopy and then comments on the delineations of RIS with reference to many related laser processes. The substance of the paper deals with the trends in RIS and especially how the needs for sensitive analytical methods have overshadowed the orginal plan to study excited species. 9 refs., 1 fig.

Hurst, G.S.

1986-01-01

398

Giant resonances in O-16  

E-print Network

Giant resonances in O-16 have been studied with inelastic scattering of 240 MeV alpha particles at small angles, Isoscalar E0, E1, and E2 strength corresponding to 48 +/- 10%, 32 +/- 7%, and 53 +/- 10%, of the respective energy-weighted sum rule...

Lui, YW; Clark, HL; Youngblood, David H.

2001-01-01

399

Electron paramagnetic resonance (EPR) biodosimetry  

Microsoft Academic Search

Radiation-induced electron paramagnetic resonance (EPR) signals were first reported by Gordy et al. [Proc. Natl. Acad. Sci. USA 41 (1955) 983]. The application of EPR spectroscopy to ionizing radiation dosimetry was later proposed by Brady et al. [HealthPhys. 15 (1968) 43]. Since that time EPR dosimetry has been applied to accident and epidemiologic dose reconstruction, radiation therapy, food irradiation, quality

Marc Desrosiers; David A Schauer

2001-01-01

400

Controlling metamaterial resonances with light  

SciTech Connect

We investigate the use of coherent optical fields as a means of dynamically controlling the resonant behavior of a variety of composite metamaterials, wherein the metamaterial structures are embedded in a dispersive dielectric medium. Control and switching are implemented by coherently driving the resonant permittivity of the embedding medium with applied optical radiation. The effect of embedding split ring resonators in a frequency-dispersive medium with Lorentz-like dispersion or with dispersion engineered by electromagnetically induced transparency (EIT) is manifested in the splitting of the negative-permeability band, the modified (frequency-dependent) filling fractions, and the dissipation factors. The modified material parameters are strongly linked to the resonant frequencies of the medium, and for an embedding medium exhibiting EIT also to the strength and detuning of the control field. The robustness of control against the deleterious influence of dissipation associated with the metallic structures as well as the inhomogeneous broadening due to structural imperfections is demonstrated. Studies on plasmonic metamaterials that consist of metallic nanorods arranged in loops and exhibit a collective magnetic response at optical frequencies are presented. Control and switching in this class of plasmonic nanorod metamaterials is shown to be possible, for example, by embedding these arrays in a Raman-active liquid like CS{sub 2} and utilizing the inverse Raman effect.

Chakrabarti, Sangeeta; Ramakrishna, S. Anantha; Wanare, Harshawardhan [Department of Physics, Indian Institute of Technology, Kanpur 208016 (India)

2010-08-15

401

Secular resonance in extrasolar system  

Microsoft Academic Search

The two orbits in the HD 160691 planetary system at first appeared highly unstable, but using a new technique called MEGNO (the acronym of Mean Exponential Growth factor of Nearby Orbits), we were able to identify a stability valley in the parameter space. This stability zone is due to the 2:1 mean motion resonance coupled with relative orbital positions of

N. Rambaux; E. Bois

2003-01-01

402

Magnetic resonance imaging of atherosclerosis  

Microsoft Academic Search

Abundant data now link composition of the vascular wall, rather than the degree of luminal narrowing, with the risk for acute ischemic syndromes in the coronary, central nervous system, and peripheral arterial beds. Over the past few years, magnetic resonance angiography has evolved as a well-established method to determine the location and severity of advanced, lumen-encroaching atherosclerotic lesions. In addition,

T. Leiner; S. Gerretsen; R. Botnar; E. Lutgens; V. Cappendijk; E. Kooi; J. van Engelshoven

2005-01-01

403

Cyclotron subharmonics resonant (CSR) heating  

NASA Astrophysics Data System (ADS)

Corresponding to the experiment done with the JIPPT-II-U device [Phys. Rev. Lett. 54, 2339 (1985)], the cyclotron subharmonics resonant (CSR) heating mechanism is studied using particle simulation codes with an emphasis on the relationship between CSR and the nonlinear Landau damping.

Abe, Hirotada

1994-08-01

404

Resonant relaxation in stellar systems  

Microsoft Academic Search

We demonstrate the existence of an enhanced rate of angular momentum relaxation in nearly Keplerian star clusters, such as those found in the centers of galactic nuclei containing massive black holes. The enhanced relaxation arises because the radial and azimuthal orbital frequencies in a Keplerian potential are equal, and hence may be termed resonant relaxation. We explore the dynamics of

Kevin P. Rauch; Scott Tremaine

1996-01-01

405

Microcoil nuclear magnetic resonance spectroscopy  

Microsoft Academic Search

In comparison with most analytical chemistry techniques, nuclear magnetic resonance has an intrinsically low sensitivity, and many potential applications are therefore precluded by the limited available quantity of certain types of sample. In recent years, there has been a trend, both commercial and academic, towards miniaturization of the receiver coil in order to increase the mass sensitivity of NMR measurements.

A. G. Webb

2005-01-01

406

Asteroid Secular Resonant Proper Elements  

NASA Astrophysics Data System (ADS)

A practical algorithm for the computation of the dynamic evolution of asteroids which are inside or close to a secular resonance has been developed. The results are checked with many numerical simulations of both real and fictitious objects. These tests prove that the algorithm is able to identify the dynamic nature of resonant objects and distinguish between future planet crossers and regular bodies. The short CPU time necessary for its execution makes it a useful tool for studying the mechanisms of meteorite transport to the inner Solar System. For this purpose, the sets of initial conditions which lead to large eccentricity in the v6 secular resonance are identified. Finally, the dynamic behavior of 44 numbered asteroids very close to the v6 resonance is analyzed. Only 4 of these asteroids are found in regions dangerous for their stability. A few others become temporary Mars crossers. The rest of them, as 6 Hebe, have a moderate eccentricity during all their quasi-periodic dynamic evolution.

Morbidelli, Alessandro

1993-09-01

407

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

408

Surface plasmon resonance sensors: review  

Microsoft Academic Search

Since the first application of the surface plasmon resonance (SPR) phenomenon for sensing almost two decades ago, this method has made great strides both in terms of instrumentation development and applications. SPR sensor technology has been commercialized and SPR biosensors have become a central tool for characterizing and quantifying biomolecular interactions. This paper attempts to review the major developments in

Ji??? Homola; Sinclair S. Yee; Günter Gauglitz

1999-01-01

409

On gravitational-electromagnetic resonance  

E-print Network

This is an English translation of the paper M.B.Mensky, in: K.P.Stanyukovich (ed.), "Problems of Theory of Gravity and Elementary Particles", issue 6, Moscow, Atomizdat, 1975, p.181-190 (in Russian). This paper elaborates further the idea (formulated in 1971 by Braginsky and Mensky) of detecting high-frequency gravitational waves by observing resonance action of a gravitational wave on the electromagnetic wave in a closed resonator (waveguide). The phenomenon underlying such a detector was called gravitational-electromagnetic resonance (GER). In the present paper both closed (for example circular) resonator or waveguide and long (for example in the shape of a spiral) waveguide are considered as possible gravitational-wave detectors. High-frequency gravitational-wave detectors are now again actual (see A.M.Cruise and R.M.J.Ingley, Class. Quant. Grav. 22, S479, 2005), but the current literature on this topic does not cover all the issues discussed in the present paper.

Michael B. Mensky

2007-12-21

410

SPR: Surface Plasmon Resonance Tutorial  

NSDL National Science Digital Library

This site provides a straightforward introduction to the fundamentals of surface plasmon resonance (SPR), the genesis of the plasmon and the evanescent wave, and how SPR can be used to monitor the chemical nature of species adsorbed to the surface of a metal substrate.

2011-04-06

411

Low field magnetic resonance imaging  

DOEpatents

A method and system of magnetic resonance imaging does not need a large homogenous field to truncate a gradient field. Spatial information is encoded into the spin magnetization by allowing the magnetization to evolve in a non-truncated gradient field and inducing a set of 180 degree rotations prior to signal acquisition.

Pines, Alexander (Berkeley, CA); Sakellariou, Dimitrios (Billancourt, FR); Meriles, Carlos A. (Fort Lee, NJ); Trabesinger, Andreas H. (London, GB)

2010-07-13

412

Microring resonator channel dropping filters  

Microsoft Academic Search

Microring resonators side coupled to signal waveguides provide compact, narrow band, and large free spectral range optical channel dropping filters. Higher order filters with improved passband characteristics and larger out-of-band signal rejection are realized through the coupling of multiple rings. The analysis of these devices is approached by the novel method of coupling of modes in time. The response of

B. E. Little; S. T. Chu; H. A. Haus; J. Foresi; J.-P. Laine

1997-01-01

413

The Electromagnetic Spectrum: Resonating Atmosphere  

NSDL National Science Digital Library

Using a paper and tape device, students experience how atoms and molecules of gas in Earthâs atmosphere absorb electromagnetic energy through resonance. This activity is part of Unit 2 in the Space Based Astronomy guide that contains background information, worksheets, assessments, extensions, and standards.

414

Orbital Resonance and Solar Cycles  

E-print Network

We present an analysis of planetary moves, encoded in DE406 ephemerides. We show resonance cycles between most planets in Solar System, of differing quality. The most precise resonance - between Earth and Venus, which not only stabilizes orbits of both planets, locks planet Venus rotation in tidal locking, but also affects the Sun: This resonance group (E+V) also influences Sunspot cycles - the position of syzygy between Earth and Venus, when the barycenter of the resonance group most closely approaches the Sun and stops for some time, relative to Jupiter planet, well matches the Sunspot cycle of 11 years, not only for the last 400 years of measured Sunspot cycles, but also in 1000 years of historical record of "severe winters". We show, how cycles in angular momentum of Earth and Venus planets match with the Sunspot cycle and how the main cycle in angular momentum of the whole Solar system (854-year cycle of Jupiter/Saturn) matches with climatologic data, assumed to show connection with Solar output power and insolation. We show the possible connections between E+V events and Solar global p-Mode frequency changes. We futher show angular momentum tables and charts for individual planets, as encoded in DE405 and DE406 ephemerides. We show, that inner planets orbit on heliocentric trajectories whereas outer planets orbit on barycentric trajectories.

P. A. Semi

2009-03-29

415

A tunable electromechanical Helmholtz resonator  

NASA Astrophysics Data System (ADS)

Acoustic liners are used in turbofan engine nacelles for the suppression of engine noise. For a given engine, there are different optimum impedance distributions associated with take-off, cut-back, and approach flight conditions. The impedance of conventional acoustic liners is fixed for a given geometry, and conventional active liner approaches are impractical. This project addresses the need for a tunable impedance through the development of an electromechanical Helmholtz resonator (EMHR). The device consists of a Helmholtz resonator with the standard rigid backplate replaced by a compliant piezoelectric composite. Analytical models (i.e., a lumped element model (LEM) and a transfer matrix (TM) representation of the EMHR) are developed to predict the acoustic behavior of the EMHR. The EMHR is experimentally investigated using the standard two-microphone method (TMM). The measurement results validate both the LEM and the TM of the EMHR. Good agreement between predicted and measured impedance is obtained. Short- and open-circuit loads define the limits of the tuning range using resistive and capacitive loads. There is approximately a 9% tuning limit under these conditions for the non-optimized resonator configuration studied. Inductive shunt loads result in a 3 degree-of-freedom (DOF) system and an enhanced tuning range of over 47% that is not restricted by the short- and open-circuit limits. Damping coefficient measurements for a piezoelectric backplate in a vacuum chamber are performed and indicate that the damping is dominated by structural damping losses. A Pareto optimization design based on models of the EMHR is performed with non-inductive loads. The EMHR with non-inductive loads has 2DOF and two resonant frequencies. The tuning ranges of the two resonant frequencies of the EMHR with non-inductive loads cannot be optimized simultaneously, so a trade-off (Pareto solution) must be reached. The Pareto solution shows how design trade-offs can be used to satisfy specific design requirements. The goal of the optimization of the EMHR with inductive loads is to achieve optimal tuning of the three resonant frequencies. The results indicate that it is possible to keep the acoustic reactance of the resonator nearly constant within a given frequency range.

Liu, Fei

416

30 CFR 922.702 - Exemption for coal extraction incidental to the extraction of other minerals.  

... 2014-07-01 false Exemption for coal extraction incidental to the extraction... MICHIGAN § 922.702 Exemption for coal extraction incidental to the extraction...Part 702 of this chapter, Exemption for Coal Extraction Incidental to the...

2014-07-01

417

30 CFR 947.702 - Exemption for coal extraction incidental to the extraction of other minerals.  

... 2014-07-01 false Exemption for coal extraction incidental to the extraction...WASHINGTON § 947.702 Exemption for coal extraction incidental to the extraction...Part 702 of this chapter, Exemption for Coal Extraction Incidental to the...

2014-07-01

418

30 CFR 903.702 - Exemption for coal extraction incidental to the extraction of other minerals.  

... 2014-07-01 false Exemption for coal extraction incidental to the extraction... ARIZONA § 903.702 Exemption for coal extraction incidental to the extraction...Part 702 of this chapter, Exemption for Coal Extraction Incidental to the...

2014-07-01

419

30 CFR 905.702 - Exemption for coal extraction incidental to the extraction of other minerals.  

... 2014-07-01 false Exemption for coal extraction incidental to the extraction...CALIFORNIA § 905.702 Exemption for coal extraction incidental to the extraction...Part 702 of this chapter, Exemption for Coal Extraction Incidental to the...

2014-07-01

420

30 CFR 941.702 - Exemption for coal extraction incidental to the extraction of other minerals.  

... 2014-07-01 false Exemption for coal extraction incidental to the extraction...SOUTH DAKOTA § 941.702 Exemption for coal extraction incidental to the extraction...Part 702 of this chapter, Exemption for Coal Extraction Incidental to the...

2014-07-01

421

30 CFR 910.702 - Exemption for coal extraction incidental to the extraction of other minerals.  

... 2014-07-01 false Exemption for coal extraction incidental to the extraction... GEORGIA § 910.702 Exemption for coal extraction incidental to the extraction...Part 702 of this chapter, Exemption for Coal Extraction Incidental to the...

2014-07-01

422

Studies of Nucleon Resonance Structure in Exclusive Meson Electroproduction  

NASA Astrophysics Data System (ADS)

Studies of the structure of excited baryons are key factors to the N* program at Jefferson Lab (JLab). Within the first year of data taking with the Hall B CLAS12 detector following the 12 GeV upgrade, a dedicated experiment will aim to extract the N* electrocouplings at high photon virtualities Q2. This experiment will allow exploration of the structure of N* resonances at the highest photon virtualities ever achieved, with a kinematic reach up to Q2 = 12 GeV2. This high-Q2 reach will make it possible to probe the excited nucleon structures at distance scales ranging from where effective degrees of freedom, such as constituent quarks, are dominant through the transition to where nearly massless bare-quark degrees of freedom are relevant. In this document, we present a detailed description of the physics that can be addressed through N* structure studies in exclusive meson electroproduction. The discussion includes recent advances in reaction theory for extracting N* electrocouplings from meson electroproduction off protons, along with Quantum Chromodynamics (QCD)-based approaches to the theoretical interpretation of these fundamental quantities. This program will afford access to the dynamics of the nonperturbative strong interaction responsible for resonance formation, and will be crucial in understanding the nature of confinement and dynamical chiral symmetry breaking in baryons, and how excited nucleons emerge from QCD.

Aznauryan, I. G.; Bashir, A.; Braun, V. M.; Brodsky, S. J.; Burkert, V. D.; Chang, L.; Chen, Ch.; El-Bennich, B.; Cloët, I. C.; Cole, P. L.; Edwards, R. G.; Fedotov, G. V.; Giannini, M. M.; Gothe, R. W.; Gross, F.; Lin, Huey-Wen; Kroll, P.; Lee, T.-S. H.; Melnitchouk, W.; Mokeev, V. I.; Peña, M. T.; Ramalho, G.; Roberts, C. D.; Santopinto, E.; de Teramond, G. F.; Tsushima, K.; Wilson, D. J.

2013-06-01

423

Planetary gearbox fault diagnosis using an adaptive stochastic resonance method  

NASA Astrophysics Data System (ADS)

Planetary gearboxes are widely used in aerospace, automotive and heavy industry applications due to their large transmission ratio, strong load-bearing capacity and high transmission efficiency. The tough operation conditions of heavy duty and intensive impact load may cause gear tooth damage such as fatigue crack and teeth missed etc. The challenging issues in fault diagnosis of planetary gearboxes include selection of sensitive measurement locations, investigation of vibration transmission paths and weak feature extraction. One of them is how to effectively discover the weak characteristics from noisy signals of faulty components in planetary gearboxes. To address the issue in fault diagnosis of planetary gearboxes, an adaptive stochastic resonance (ASR) method is proposed in this paper. The ASR method utilizes the optimization ability of ant colony algorithms and adaptively realizes the optimal stochastic resonance system matching input signals. Using the ASR method, the noise may be weakened and weak characteristics highlighted, and therefore the faults can be diagnosed accurately. A planetary gearbox test rig is established and experiments with sun gear faults including a chipped tooth and a missing tooth are conducted. And the vibration signals are collected under the loaded condition and various motor speeds. The proposed method is used to process the collected signals and the results of feature extraction and fault diagnosis demonstrate its effectiveness.

Lei, Yaguo; Han, Dong; Lin, Jing; He, Zhengjia

2013-07-01

424

[Magnetic resonance in biomedical research].  

PubMed

Magnetic resonances are spectroscopic methods by which some structural changes and metabolic processes in biological systems can be followed on the molecular level. There are two main types of magnetic resonance methods: nuclear magnetic resonance (NMR) and electron paramagnetic (spin) resonance (EPR or ESR). By NMR are followed the atomic nuclei with the magnetic moment; in biological systems these are usually 1H, 13C, 31P. By EPR are followed paramagnetic centres in biological systems; these are ions of the transition metal group (Fe3+, Cu2+, Mn2+), which appear as cofactors of the enzymes, or free radicals, which are intermediates in biochemical reactions. Instead of paramagnetic centres, which are native in biological systems, very often the molecules with a free radical are incorporated into the system--spin labels or spin probes. Centres with the magnetic moment serve as markers conveying the information about the metabolic processes in biological systems and about the changes in these processes in pathological conditions or under the influence of biologically active substances. In this work several typical applications of EPR and NMR in biomedical research are described showing a great variety of issues where magnetic resonances can be used. EPR experiments: Study of the microgeography of acetylcholinesterase active centre and the conformational changes of this centre under the influence of cholinergic substances. Changes in cell membrane fluidity under the influence of neurotoxins. Transport of cocarcinogens, forbolesters, through the cell membrane. Application of magnetic field gradient to the investigation of transport through the tissues. NMR experiments: Application of 1H-NMR to characterization of brain tumours in vitro and possible application of NMR tomography in vivo to diagnosis of tumours and other pathological conditions. Application of 31P-NMR for investigation of metabolic properties of skeletal muscles. PMID:2174235

Sentjurc, M

1990-06-01

425

Resonance formation in photon-photon collisions  

SciTech Connect

Recent experimental progress on resonance formation in photon-photon collisions is reviewed with particular emphasis on the pseudoscalar and tensor nonents and on the ..gamma gamma..* production of spin-one resonances. 37 refs., 17 figs., 5 tabs.

Gidal, G.

1988-08-01

426

International Society for Magnetic Resonance in Medicine  

MedlinePLUS

... Workshop & Educational Course Series ISMRM Workshop on Magnetic Resonance in Cancer: Challenges & Unmet Needs 06-09 November ... required) ALS Ice Bucket Challenge Videos Updated! Magnetic Resonance in Medicine 30th Anniversary (Password required) In Memoriam ...

427

Fermion resonance in quantum field theory  

E-print Network

We derive accurately the fermion resonance propagator by means of Dyson summation of the self-energy contribution. It turns out that the relativistic fermion resonance differs essentially from its boson analog.

M. O. Gonchar; A. E. Kaloshin; V. P. Lomov

2006-11-25

428

Adaptive feature extraction expert  

SciTech Connect

The identification of discriminatory features places an upper bound on the recognition rate of any automatic speech recognition (ASR) system. One way to structure the extraction of features is to construct an expert system which applies a set of rules to identify particular properties of the speech patterns. However, these patterns vary for an individual speaker and from speaker to speaker so that another expert is actually needed to learn the new variations. The author investigates the problem by using sets of discriminatory features that are suggested by a feature generation expert, improves the selectivity of these features with a training expert, and finally develops a minimally spanning feature set with a statistical selection expert. 12 references.

Yuschik, M.

1983-01-01

429

Electroproduction of eta mesons in the S11(1535) resonance region at high momentum transfer  

Microsoft Academic Search

The differential cross section for the process p(e,e'p)eta has been measured at Q2~5.7 and 7.0(GeV\\/c)2 for center-of-mass energies from threshold to 1.8 GeV, encompassing the S11(1535) resonance, which dominates the channel. This is the highest momentum-transfer measurement of this exclusive process to date. The helicity-conserving transition amplitude A1\\/2, for the production of the S11(1535) resonance, is extracted from the data.

Mark Dalton; Gary Adams; Abdellah Ahmidouch; Tatiana Angelescu; John Arrington; Razmik Asaturyan; O. K. Baker; Nawal Benmouna; Crystal Bertoncini; Werner Boeglin; Peter Bosted; Herbert Breuer; M. E. Christy; S. H. Connell; Y. Cui; S. Danagoulian; D. Dutta; T. Dodario; James Dunne; N. El Khayari; R. Ent; Howard Fenker; Valera Frolov; Liping Gan; David Gaskell; Kawtar Hafidi; Wendy Hinton; Roy Holt; Tanja Horn; Garth Huber; Ed Hungerford; Xiaodong Jiang; Mark Jones; Kyungseon Joo; Narbe Kalantarians; J. J. Kelly; Cynthia Keppel; V. Kubarovsky; Y. Li; Y. Liang; S. Malace; P. Markowitz; P. McKee; D. G. Meekins; H. Mkrtchyan; B. Moziak; T. Navasardyan; G. Niculescu; I. Niculescu; A. K. Opper; T. Ostapenko; P. E. Reimer; J. Reinhold; J. Roche; S. E. Rock; E. Schulte; E. Segbefia; C. Smith; G. R. Smith; P. Stoler; V. Tadevosyan; L. Tang; V. Tvaskis; M. Ungaro; A. Uzzle; S. Vidakovic; A. Villano; W. F. Vulcan; M. Wang; G. Warren; F. R. Wesselmann; B. Wojtsekhowski; S. A. Wood; C. Xu; L. Yuan; X. Zheng; H. Zhu; Xiaochao Zheng

2009-01-01

430

Nucleon resonance electrocouplings in the non-perturbative regime  

SciTech Connect

There is an extensive search for baryon resonances using the CLAS detector in Hall B of JLab. Extracting the transition helicity amplitudes (or the {gamma}{sub v}NN* photo- and electrocouplings) sheds light on nature of the non-perturbative strong interaction. We have extended the data on differential cross sections to Q{sup 2} = 6.0 GeV{sup 2} for the {pi}N electroproduction channel. Electroproduction data were also collected on the two-charged-pion channel off protons, which provides nine independent differential {pi}{sup +}{pi}{sup -}p cross sections at Q{sup 2} up to 1.5 GeV{sup 2}. The two-pion results, moreover, are consistent with those from independent {pi}N electroproduction analyses, where the background contributions in the two-pion channel are completely different from that of the single-pion one. A phenomenological approach developed at Jefferson Lab - Moscow State University is employed for separating the resonant and non-resonant contributions to the final state. The Q{sup 2}-dependent electrocouplings were then obtained for the P{sub 11}(1440) and D{sub 13}(1520) excited baryon states. The new data will be discussed in light of these new developments in systematically exploring the affects of meson-baryon dressing on the transition helicity amplitudes as a function of Q{sup 2}.

Philip L. Cole, Viktor Mokeev, Ralf Gothe

2012-09-01

431

Designing triple resonance Tesla transformers of arbitrary modal frequency ratio  

NASA Astrophysics Data System (ADS)

The purpose of this article is to disclose an automated method to design and investigate multimegavolt triple resonance Tesla transformers. The pulse transformer's "frequency equation" is presented for the first time. The frequency equation derivation properly models all the inductors, with their self-capacitances, which have yet to be treated in an orthodox manner. The analysis gives new insight into the transformer by showing the relationship between the roots of the frequency equation and the transformer's modal frequencies. The roots are shown to be subject to manipulation, and so the modal frequencies are controllable. The method efficiently extracts solutions (transformer circuits) from the frequency equation constrained to oscillate at an arbitrary and general modal frequency ratio (to include noninteger). A ratio of the present general interest is 1:2:3. This particular ratio forces the maxima of the three coexisting modal oscillations to align, and their amplitudes sum to produce a local maximum, at a specific time. The same alignment phenomenon occurs with the dual resonance transformer with a modal ratio of 1:2. A pulse transformer is designed as a demonstration. The energy in each of the three oscillations is examined at the moment of peak voltage in the demonstration transformer to show the investigative power of the new equations. This generalized tool will prove useful in the campaign to analytically locate global maximums from the triple resonance transformer's governing amplitude equation for output voltage.

Reed, John Randolph

2006-03-01

432

An Extended Keyword Extraction Method  

NASA Astrophysics Data System (ADS)

Among numerous Chinese keyword extraction methods, Chinese characteristics were shortly considered. This phenomenon going against the precision enhancement of the Chinese keyword extraction. An extended term frequency based method(Extended TF) is proposed in this paper which combined Chinese linguistic characteristics with basic TF method. Unary, binary and ternary grammars for the candidate keyword extraction as well as other linguistic features were all taken into account. The method establishes classification model using support vector machine. Tests show that the proposed extraction method improved key words precision and recall rate significantly. We applied the key words extracted by the extended TF method into the text file classification. Results show that the key words extracted by the proposed method contributed greatly to raising the precision of text file classification.

Hong, Bao; Zhen, Deng

433

A Primer on Resonances in Quantum Mechanics  

E-print Network

After a pedagogical introduction to the concept of resonance in classical and quantum mechanics, some interesting applications are discussed. The subject includes resonances occurring as one of the effects of radiative reaction, the resonances involved in the refraction of electromagnetic waves by a medium with a complex refractive index, and quantum decaying systems described in terms of resonant states of the energy. Some useful mathematical approaches like the Fourier transform, the complex scaling method and the Darboux transformation are also reviewed.

O. Rosas-Ortiz; N. Fernandez-Garcia; Sara Cruz y Cruz

2009-02-24

434

A Primer on Resonances in Quantum Mechanics  

E-print Network

After a pedagogical introduction to the concept of resonance in classical and quantum mechanics, some interesting applications are discussed. The subject includes resonances occurring as one of the effects of radiative reaction, the resonances involved in the refraction of electromagnetic waves by a medium with a complex refractive index, and quantum decaying systems described in terms of resonant states of the energy. Some useful mathematical approaches like the Fourier transform, the complex scaling method and the Darboux transformation are also reviewed.

Rosas-Ortiz, O; Cruz, Sara Cruz y; 10.1063/1.3040259

2009-01-01

435

Nonlinear Thermal Compensators for WGM Resonators  

NASA Technical Reports Server (NTRS)

In an alternative version of a proposed bimaterial thermal compensator for a whispering-gallery-mode (WGM) optical resonator, a mechanical element having nonlinear stiffness would be added to enable stabilization of a desired resonance frequency at a suitable fixed working temperature. The previous version was described in "Bimaterial Thermal Compensators for WGM Resonators." Both versions are intended to serve as inexpensive means of preventing (to first order) or reducing temperature-related changes in resonance frequencies.

Savchenkov, Anatoliy; Matsko, Andrey; Strekalov, Dmitry; Maleki, Lute; Yu, Nan; Iltchenko, Vladimir

2009-01-01

436

FDTD study of resonance Processes in metamaterials  

Microsoft Academic Search

The finite-difference time-domain simulations in the frequency domain are used to study resonance phenomena in left-handed metamaterials consisting of the arrays of split-ring resonators (SRRs) and metal rods. It is demonstrated that, at frequencies corresponding to the band of enhanced transmission of the metamaterial, the half-wavelength resonances occur in both the SRRs and rods. The observed resonances in rods make

Elena A. Semouchkina; George B. Semouchkin; Michael Lanagan; Clive A. Randall

2005-01-01

437

Parametric resonance in neutrino oscillations in matter  

E-print Network

Neutrino oscillations in matter can exhibit a specific resonance enhancement -- parametric resonance, which is different from the MSW resonance. Oscillations of atmospheric and solar neutrinos inside the earth can undergo parametric enhancement when neutrino trajectories cross the core of the earth. In this paper we review the parametric resonance of neutrino oscillations in matter. In particular, physical interpretation of the effect and the prospects of its experimental observation in oscillations of solar and atmospheric neutrinos in the earth are discussed.

E. Kh. Akhmedov

1999-07-20

438

Theory of atomic motion in resonant radiation  

SciTech Connect

Atomic motion in resonant and near resonant electromagnetic radiation is investigated theoretically. The exposition begins with a study of atomic motion in a resonant standing light wave, with a view toward isotope separation by selective photodeflection, and proceeds to the investigation of more general problems of atomic motion in resonant radiation. The body of the work consists of six chapters, each of which was prepared as a manuscript for publication in the open literature.

Cook, R.J.

1980-03-01

439

Coupled mode theory of optical resonant cavities  

Microsoft Academic Search

This paper presents a theory describing coupled optical resonant cavities by means of systems of time-dependent coupled equations for the field amplitudes of standing waves in each resonator. The coupling coefficients entering the theory are derived from first principles. The coupling coefficients can approximately be related to the amplitude transmission coefficients of traveling waves passing between the two resonant cavities.

D. Marcuse

1985-01-01

440

The Resonant Body Transistor Dana Weinstein,*,  

E-print Network

The Resonant Body Transistor Dana Weinstein,*, and Sunil A. Bhave Cornell University, 405 Phillips Hall, Ithaca, New York 14853 ABSTRACT This paper introduces the resonant body transistor (RBT), a silicon-based dielectrically transduced nanoelectromechanical (NEM) resonator embedding a sense transistor

Afshari, Ehsan

441

MEMS Tutorial: Nonlinearity in Micromechanical Resonators  

E-print Network

MEMS Tutorial: Nonlinearity in Micromechanical Resonators In this tutorial, we cover the effect in this tutorial follows closely to Landau [2] but the presentation has been slightly modernized. Preliminaries of this tutorial is on resonators, we'll concentrate on the response near the resonance frequency. m k k F X = k

Kaajakari, Ville

442

Reducing the Probability of Capture into Resonance  

E-print Network

A migrating planet can capture planetesimals into mean motion resonances. However, resonant trapping can be prevented when the drift or migration rate is sufficiently high. Using a simple Hamiltonian system for first and second order resonances, we explore how the capture probability depends on the order of the resonance, drift rate and initial particle eccentricity. We present scaling factors as a function of the planet mass and resonance strength to estimate the planetary migration rate above which the capture probability drops to less than 1/2. Applying our framework to multiple extra solar planetary systems that have two planets locked in resonance, we estimate lower limits for the outer planet's migration rate allowing resonance capture of the inner planet. Mean motion resonances are comprised of multiple resonant subterms. We find that the corotation subterm can reduce the probability of capture when the planet eccentricity is above a critical value. We present factors that can be used to estimate this critical planet eccentricity. Applying our framework to the migration of Neptune, we find that Neptune's eccentricity is near the critical value that would make its 2:1 resonance fail to capture twotinos. The capture probability is affected by the separation between resonant subterms and so is also a function of the precession rates of the longitudes of periapse of both planet and particle near resonance.

Alice C. Quillen

2005-07-20

443

Sonic crystal with open resonant cavities  

Microsoft Academic Search

An improved scattering matrix method is developed to study a two-dimensional air-rigid sonic crystal with open resonant cavity, and the band structure and transmission properties are investigated. Numerical results show that both the band structure and the transmission coefficient are sensitive to the shape of the resonant cavity. The relationship between the resonant band gap and the shape of the

Zhilin Hou; Jingtao Liu; Weimin Kuang; Youyan Liu; Shuizhu Wu

2007-01-01

444

Microwave oscillators incorporating cryogenic sapphire dielectric resonators  

Microsoft Academic Search

Progress is reported on efforts to develop a commercially-viable high purity X-band signal source incorporating a cryogenic sapphire dielectric resonator. The resonator design is of the whispering gallery type to take advantage of the excellent electromagnetic field confinement offered by this geometry. Complications resulting from the high spurious mode density of this type of resonator have been eliminated by developing

R. C. Taber; C. A. Flory

1995-01-01

445

Slow Passage through Multiple Parametric Resonance Tongues  

E-print Network

be reduced to the Mathieu equation, and is said to involve a single resonance. However, if the variation has is said to involve multiple resonances. The simplest example of such a system is the Mathieu equation;1582 J. BRIDGE ET AL. Figure 1. Form of the two large resonant tongues in a Mathieu equation with two

Rand, Richard H.

446

Mean motion resonances. [of asteroid belt structure  

NASA Technical Reports Server (NTRS)

Recent research on the resonant structure of the asteroid belt is reviewed. The resonant mechanism is discussed, and analytical models for the study of mean motion resonances are examined. Numerical averaging methods and mapping methods are considered. It is shown how fresh insight can be obtained by means of a new semianalytical approach.

Froeschle, CL.; Greenberg, R.

1989-01-01

447

Transient resonance of rolling finned projectiles  

Microsoft Academic Search

Finned projectiles that are intentionally spun are known to become locked in at a resonance condition where the roll rate matches the pitch\\/yaw frequency. This phenomenon, called roll lock-in, results in an amplification of the trim angle, which can lead to yaw instability. A less severe phenomenon is that of transient resonance where the roll rate locks in at resonance

N Ananthkrishnan; S C Raisinghani; S Pradeep

1999-01-01

448

Resonant frequency of Hilbert curve fractal antennas  

Microsoft Academic Search

An approximate formulation for the resonant frequency of a dipole Hilbert curve fractal antenna (HCFA) is derived here. These can be used as small resonant antennas, useful in VHF\\/UHF communication. The formulas presented here can be appropriately inverted to obtain the design equations for the antenna, for a given resonant frequency

K. J. Vinoy; K. A. Jose; V. K. Varadan; V. V. Varadan

2001-01-01

449

VIBRATIONAL RESONANCE IN AN ASYMMETRIC DUFFING OSCILLATOR  

E-print Network

VIBRATIONAL RESONANCE IN AN ASYMMETRIC DUFFING OSCILLATOR S. JEYAKUMARI, V. CHINNATHAMBI Department- tional resonance. We obtain, numerically and theoretically, the values of the low-frequency and amplitude of the high-frequency forces at which vibrational resonance occurs. Furthermore, we observe that an additional

Rey Juan Carlos, Universidad

450

Extraction chromatography: Progress and opportunities  

SciTech Connect

Extraction chromatography provides a simple and effective method for the analytical and preparative-scale separation of a variety of metal ions. Recent advances in extractant design, particularly the development of extractants capable of metal ion recognition or of strong complex formation in highly acidic media, have significantly improved the utility of the technique. Advances in support design, most notably the introduction of functionalized supports to enhance metal ion retention, promise to yield further improvements. Column instability remains a significant obstacle, however, to the process-scale application of extraction chromatography. 79 refs.

Dietz, M.L.; Horwitz, E.P.; Bond, A.H. [Argonne National Lab., IL (United States). Chemistry Div.

1997-10-01

451

Terminology Extraction from Log Files  

NASA Astrophysics Data System (ADS)

The log files generated by digital systems can be used in management information systems as the source of important information on the condition of systems. However, log files are not exhaustively exploited in order to extract information. The classical methods of information extraction such as terminology extraction methods are irrelevant to this context because of the specific characteristics of log files like their heterogeneous structure, the special vocabulary and the fact that they do not respect a natural language grammar. In this paper, we introduce our approach Exterlog to extract the terminology from log files. We detail how it deals with the particularity of such textual data.

Saneifar, Hassan; Bonniol, Stéphane; Laurent, Anne; Poncelet, Pascal; Roche, Mathieu

452

Passive vapor extraction feasibility study  

SciTech Connect

Demonstration of a passive vapor extraction remediation system is planned for sites in the 200 West Area used in the past for the disposal of waste liquids containing carbon tetrachloride. The passive vapor extraction units will consist of a 4-in.-diameter pipe, a check valve, a canister filled with granular activated carbon, and a wind turbine. The check valve will prevent inflow of air that otherwise would dilute the soil gas and make its subsequent extraction less efficient. The granular activated carbon is used to adsorb the carbon tetrachloride from the air. The wind turbine enhances extraction rates on windy days. Passive vapor extraction units will be designed and operated to meet all applicable or relevant and appropriate requirements. Based on a cost analysis, passive vapor extraction was found to be a cost-effective method for remediation of soils containing lower concentrations of volatile contaminants. Passive vapor extraction used on wells that average 10-stdft{sup 3}/min air flow rates was found to be more cost effective than active vapor extraction for concentrations below 500 parts per million by volume (ppm) of carbon tetrachloride. For wells that average 5-stdft{sup 3}/min air flow rates, passive vapor extraction is more cost effective below 100 ppm.

Rohay, V.J.

1994-06-30

453

Fano resonances in active plasmonic resonators consisting of a nanorod dimer and a nano-emitter  

E-print Network

Fano resonances in active plasmonic resonators consisting of a nanorod dimer and a nano-emitter resonances in active plasmonic resonators consisting of a nanorod dimer and a nano-emitter Zhong-Jian Yang,1; published online 24 August 2011) The optical emission response of a single nano-emitter coupled

454

Design criteria for resonant tank of LLC DC-DC resonant converter  

Microsoft Academic Search

This paper presents the design criteria for the resonant tank of the LLC resonant DC-DC converter. In order to have high efficiency within wide input voltage range, high power factor for the LLC resonant tank should be ensured. The inductance ratio of the series and parallel resonant inductors is designed according to the voltage gain and input power factor of

Ray-Lee Lin; Chiao-Wen Lin

2010-01-01

455

Resonant Tunnelling in Semiconductor Heterostructures  

NASA Astrophysics Data System (ADS)

Available from UMI in association with The British Library. A number of physical processes are investigated in this thesis, with particular regard to the effect of high magnetic fields on the tunnelling process. A brief outline is as follows: In the remainder of this chapter, the fundamental properties of GaAs and (AlGa)As relevant to this thesis are presented followed by a brief outline of some of the basic concepts in the theory of resonant tunnelling. In Chapter 2 the experimental techniques used to obtain the results are described and details of the samples are given. Chapter 3 describes several aspects of both resonant and non-resonant tunnelling in double barrier structures. Section 3.3 uses magnetoquantum oscillations in the tunnel current and differential capacitance to characterise the 2DEG in the emitter accumulation layer, Section 3.4 presents an investigation of the contributions of elastic scattering and scLO phonon scattering to the valley current using high magnetic fields, the temperature dependence of the I(V) characteristics is analysed in Section 3.5 and Section 3.6 discusses ballistic transport and quantum interference effects in wide quantum wells. Chapter 4 presents a detailed study of bistability in double barrier devices, showing first how charge buildup in the quantum well or high-frequency oscillations in the measuring circuit can lead to hysteresis in the current-voltage characteristics and then using an asymmetric structure to enhance charge buildup and observe a genuinely intrinsic bistability. Fourier analysis of magnetoquantum oscillations in a magnetic field applied parallel to the current demonstrates that carriers undergo energy relaxation in the well and therefore the tunnelling process is sequential. Two new effects are noted, the enhancement of charge buildup in high magnetic fields and the observation of a region of inverted bistability in a very asymmetric structure where the off-resonant current actually exceeds the resonant current. Chapter 5 investigates the effect of a magnetic field applied perpendicular to the current. In samples with relatively narrow quantum wells (<200 A), a broadening of the resonance consistent with the conservation of canonical momentum is observed and in wider wells, tunnelling into hybrid magnetoelectric energy levels is seen. Rotation of the magnetic field direction is used to probe the anisotropy of the conduction band and to investigate energy levels in a tilted field. (Abstract shortened by UMI.).

Leadbeater, Mark Levence

1990-01-01

456

Individual resonance parameters for nuclei Z = 2 -100  

E-print Network

Individual resonance parameters for nuclei Z = 2 -100 Thermal cross sections, coherent scattering amplitudes for Z = 1 ­ 100 Average resonance parameters, level spacings, capture widths, neutron strength sections, and resonance integrals Updated introduction stressing the systematics of average resonance

Ohta, Shigemi

457

Isoflavone extraction from okara using water as extractant.  

PubMed

We here report on the use of water as a 'green' extraction solvent for the isolation of isoflavones from okara, a by-product of soymilk production. At a low liquid-to-solid ratio of 20 to 1 and 20 °C, 47% of the isoflavones that can be extracted with 70% aqueous ethanol were extracted. The malonyl-glucosides were fully recovered with a ratio of 20 to 1, while ?-glucosides were recovered with an increased liquid-to-solid ratio of 40 to 1. The extraction of aglycones was better at higher ratios, but leveled off before reaching a 100% yield. Temperature hardly affected the total amount of isoflavones. At a 20 to 1 ratio, 20 °C, and pH 10, there was no significant difference (p>0.05) between isoflavone extraction in water and in 70% aqueous ethanol. The results suggest that water may be used as a green alternative for separation of isoflavones from okara. PMID:24799251

Jankowiak, Lena; Kantzas, Nikolaos; Boom, Remko; van der Goot, Atze Jan

2014-10-01

458

Antioxidative and antiproliferative activities of different horsetail (Equisetum arvense L.) extracts.  

PubMed

In this study we investigated antioxidative and antiproliferative activity of different horsetail (Equisetum arvense L.) extracts. The antioxidative activity was measured by the electron spin resonance (ESR) spectroscopy-spin trapping method. The influence of different horsetail extracts during lipid peroxidation of (1) sunflower oil induced by the lipophilic azo-initiator 4,4'-azobis(4-cyanovaleric acid) and (2) soybean phosphatidylcholine liposomes induced by the hydrophilic azo-initiator 2,2'-azobis(2-amidinopropane) dihydrochloride was studied. Antiproliferative activity was measured using the sulforhodamine B colorimetric assay on the human cancer cell lines HeLa, HT-29, and MCF7. The results of ESR analysis confirmed that the extracts investigated suppressed the formation of lipid peroxyl radicals in both systems investigated in a dose-dependent manner. The results indicate that n-butanol, methanol, ethyl acetate, and water extracts had significant peroxyl radical scavenging activity. Extracts inhibited cell growth that was dependent on cell line, type of extract, and extract concentration. Ethyl acetate extract exhibited the most prominent antiproliferative effect, without inducing any cell growth stimulation on human tumor cell lines. The results obtained suggest that the horsetail extracts could be used as an easily accessible source of natural antioxidants and as potential phytochemicals. PMID:20170379

Cetojevi?-Simin, Dragana D; Canadanovi?-Brunet, Jasna M; Bogdanovi?, Gordana M; Djilas, Sonja M; Cetkovi?, Gordana S; Tumbas, Vesna T; Stojiljkovi?, Bratislav T

2010-04-01

459

Artemisia capillaris extracts as a green factory for the synthesis of silver nanoparticles with antibacterial activities.  

PubMed

We report a green synthesis of silver nanoparticles that uses extracts from the aerial part of Artemisia capillaris. Both water and 70% ethanol extracts successfully generated silver nanoparticles. The formation of silver nanoparticles was confirmed by surface plasmon resonance bands, Fourier transform-infrared spectra, high resolution-transmission electron and atomic force microscopic images. Various shapes of silver nanoparticles were generated with an average diameter of 29.71 nm with water extract and 29.62 nm with 70% ethanol extract. An improvement in antibacterial activity (MIC 8.35-16.7 microg/mL) was observed against a total of twenty different strains of Gram-negative and Gram-positive bacteria. A remarkable enhancement (approximately 12-fold) was observed against Pseudomonas aeruginosa, Escherichia coli, Enterobacter cloacae, Klebsiella oxytoca, and Klebsiella areogenes when compared with the extract alone. Silver nanoparticles produced by the 70% ethanol extract showed slightly higher antibacterial activity than those generated with the water extract. The correlation between total flavonoid content of each extract and the antibacterial activity did not exert any significant relationships. This report suggests that plant extracts have the potential to be used as powerful reducing agents for the production of biocompatible silver nanoparticles possessing enhanced antibacterial activities. PMID:23035437

Park, Youmie; Noh, Hwa Jung; Han, Lina; Kim, Hyun-Seok; Kim, Yong-Jae; Choi, Jae Sue; Kim, Chong-Kook; Kim, Yeong Shik; Cho, Seonho

2012-09-01

460

MULTIPLE SINGLE BUNCH EXTRACTION TO THE AGS SWITCHYARD.  

SciTech Connect

In this report we will describe the multiple single bunch extraction system as utilized to deliver beams to the Brookhaven's Alternating Gradient Synchrotron (AGS) switchyard area. We will describe modifications of the AGS switchyard, necessary to allow it to accept bunched beam, and results of the first commissioning of this system. The AGS Switchyard has for many years been used to simultaneously deliver (unbunched) resonant extracted beam to a set of fixed target experiments. In order to accommodate new fixed target experiments which require bunched beams, a method of sending the bunched beams to the AGS Switchyard was required. In addition, by using the AGS switchyard instead of the upstream section of the Brookhaven's Relativistic Heavy Ion Collider (RHIC) injection line the accelerators can be reconfigured quickly and efficiently for filling RHIC. We will present results of the commissioning of this system, which was done in January 2001.

BROWN,K.A.; AHRENS,L.; GASSNER,D.; GLENN,J.W.; ROSER,T.; SMITH,G.; TSOUPAS,N.; VAN ASSELT,W.; ZENO,K.

2001-06-18

461

Electron current extraction from a permanent magnet waveguide plasma cathode  

NASA Astrophysics Data System (ADS)

An electron cyclotron resonance plasma produced in a cylindrical waveguide with external permanent magnets was investigated as a possible plasma cathode electron source. The configuration is desirable in that it eliminates the need for a physical antenna inserted into the plasma, the erosion of which limits operating lifetime. Plasma bulk density was found to be overdense in the source. Extraction currents over 4 A were achieved with the device. Measurements of extracted electron currents were similar to calculated currents, which were estimated using Langmuir probe measurements at the plasma cathode orifice and along the length of the external plume. The influence of facility effects and trace ionization in the anode-cathode gap are also discussed.

Weatherford, B. R.; Foster, J. E.; Kamhawi, H.

2011-09-01

462

Electron current extraction from a permanent magnet waveguide plasma cathode.  

PubMed

An electron cyclotron resonance plasma produced in a cylindrical waveguide with external permanent magnets was investigated as a possible plasma cathode electron source. The configuration is desirable in that it eliminates the need for a physical antenna inserted into the plasma, the erosion of which limits operating lifetime. Plasma bulk density was found to be overdense in the source. Extraction currents over 4 A were achieved with the device. Measurements of extracted electron currents were similar to calculated currents, which were estimated using Langmuir probe measurements at the plasma cathode orifice and along the length of the external plume. The influence of facility effects and trace ionization in the anode-cathode gap are also discussed. PMID:21974587

Weatherford, B R; Foster, J E; Kamhawi, H

2011-09-01

463

Equivalent Circuit Model for Thick Split Ring Resonators and Thick Spiral Resonators  

E-print Network

A simple theoretical model which provides circuit parameters and resonance frequency of metallic thick resonators is presented. Two different topologies were studied: the original Pendry's SRR and spiral resonators of two and three turns. Theoretical computations of resonant frequencies are in good agreement with values obtained with a commercial electromagnetic solver. The model could be helpful for designing thick frequency selective surfaces (FSS) based on this types of resonators, so called metasurfaces.

Mancera, Laura Maria Pulido

2014-01-01

464

Magnetic Resonance Connectome Automated Pipeline  

E-print Network

This manuscript presents a novel, tightly integrated pipeline for estimating a connectome, which is a comprehensive description of the neural circuits in the brain. The pipeline utilizes magnetic resonance imaging (MRI) data to produce a high-level estimate of the structural connectivity in the human brain. The Magnetic Resonance Connectome Automated Pipeline (MRCAP) is efficient and its modular construction allows researchers to modify algorithms to meet their specific requirements. The pipeline has been validated and over 200 connectomes have been processed and analyzed to date. This tool enables the prediction and assessment of various cognitive covariates, and this research is applicable to a variety of domains and applications. MRCAP will enable MR connectomes to be rapidly generated to ultimately help spur discoveries about the structure and function of the human brain.

Gray, William R; Vogelstein, Joshua T; Landman, Bennett A; Prince, Jerry L; Vogelstein, R Jacob

2011-01-01

465

Resonance microwave volume plasma source  

SciTech Connect

A conceptual design of a microwave gas-discharge plasma source is described. The possibility is considered of creating conditions under which microwave energy in the plasma resonance region would be efficiently converted into the energy of thermal and accelerated (fast) electrons. Results are presented from interferometric and probe measurements of the plasma density in a coaxial microwave plasmatron, as well as the data from probe measurements of the plasma potential and electron temperature. The dynamics of plasma radiation was recorded using a streak camera and a collimated photomultiplier. The experimental results indicate that, at relatively low pressures of the working gas, the nonlinear interaction between the microwave field and the inhomogeneous plasma in the resonance region of the plasmatron substantially affects the parameters of the ionized gas in the reactor volume.

Berezhetskaya, N. K.; Kop'ev, V. A.; Kossyi, I. A.; Malykh, N. I.; Misakyan, M. A.; Taktakishvili, M. I.; Temchin, S. M. [Russian Academy of Sciences, Prokhorov Institute of General Physics (Russian Federation); Lee, Young Dong [Samsung Advanced Institute of Technology (Korea, Republic of)

2007-07-15