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1

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

2

Temporal feature extraction in photorefractive resonators  

NASA Astrophysics Data System (ADS)

A holographic optical system listens to an incoming signal and extracts the most common repetitive temporal features of that signal. An example might be to extract the features of Morse code, which consists of two tone lengths and two pause lengths. This optical system is self-organizing, in that very little a priori information is imbeded in the system to indicate what form the temporal signals take. The primary constraints imposed on the signal is: (1) finite bandwidth; (2) limited feature duration; and (3) rates of reoccurrence. The optical apparatus uses a photorefractively pumped multimode optical oscillator having a delay line in the feedback loop. The delay line serves to translate the temporal dimension into a spatial one, and it also builds into the system a notion of the direction of time. Temporal feature extraction takes place as a competitive interaction among sets of modes, which are termed chronomodes. Experiments illustrate the principles of such a system by extracting the two most probable temporal features from a signal imposed on a laser beam.

Anderson, Dana Z.; Zhou, Gan; Montemezzani, Germano

1994-12-01

3

Power-recycled Michelson interferometer with resonant sideband extraction.  

PubMed

We present a system for the control and signal extraction of a power-recycled Michelson interferometer with resonant sideband extraction. This control system is capable of locking four degrees of freedom to a fixed point while locking the signal cavity to an arbitrary detuned point. One of the strengths of this system is that it can quickly change the instrument's frequency response without disrupting continuous operation. We report on an experimental implementation of this control system on a benchtop prototype and present broadband measurements of the prototype's frequency response for a range of signal cavity detunings. PMID:12638885

Shaddock, Daniel A; Gray, Malcolm B; Mow-Lowry, Conor; McClelland, David E

2003-03-01

4

Antioxidant activity of enzymatic extracts from the brown seaweed Undaria pinnatifida by electron spin resonance spectroscopy  

Microsoft Academic Search

Enzyme assisted extraction of Undaria pinnatifida was performed using five proteases (Alcalase, Flavourzyme, Neutrase, Trypsin and Protamex) and six carbohydrases (AMG, Dextrozyme, Maltogenase, Promozyme, Viscozyme and Celluclast) in order to acquire extracts rich in antioxidants. Antioxidant activity of the extracts was investigated using electron spin resonance (ESR) spectroscopy on 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and superoxide radicals. Extracts exhibited strong radical scavenging

Jae-Young Je; Pyo-Jam Park; Eun-Kyung Kim; Jung-Suk Park; Ho-Dong Yoon; Kwang-Rae Kim; Chang-Bum Ahn

2009-01-01

5

Improved ion extraction from an electron cyclotron resonance ion source by a metal-dielectric-extraction electrode  

NASA Astrophysics Data System (ADS)

The goal of the experiment was to study the influence and the physics of the boundary region (between the plasma and the extraction potential) with direct impact on the source ion-beam output. A specially processed high-emissive metal-dielectric structure was installed on the extraction electrode of the Frankfurt 14GHz electron cyclotron resonance ion source (ECRIS), forming a so-called metal-dielectric- (MD) extraction electrode. The emissive layer of the disk faced the plasma; its inner hole was about the size of the normal extraction hole of the ECRIS. The output of the ECRIS in the presence of the MD electrode was compared with the outputs for the standard configuration (overall stainless-steel plasma chamber) and with the same plasma chamber with the radial wall covered by a highly electron emissive MD liner that raise the plasma electron density and temperature. The charge state distributions of the argon ions extracted from the source show an important increase of the ion beam for the high charge states as compared to the standard situation whereas the low charge states are less reduced than in the case of the presence of a MD liner. Due to the special position of the dielectric layer, the MD electrode introduces a new effect, which is connected to its property of becoming a positively charged surface under electron and ion bombardment. The MD electrode creates a quasiconfinement of the peripheral ions in the extraction, those ions that are normally lost to a conducting extraction electrode.

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

2006-03-01

6

Improved ion extraction from an electron cyclotron resonance ion source by a metal-dielectric-extraction electrode  

SciTech Connect

The goal of the experiment was to study the influence and the physics of the boundary region (between the plasma and the extraction potential) with direct impact on the source ion-beam output. A specially processed high-emissive metal-dielectric structure was installed on the extraction electrode of the Frankfurt 14 GHz electron cyclotron resonance ion source (ECRIS), forming a so-called metal-dielectric- (MD) extraction electrode. The emissive layer of the disk faced the plasma; its inner hole was about the size of the normal extraction hole of the ECRIS. The output of the ECRIS in the presence of the MD electrode was compared with the outputs for the standard configuration (overall stainless-steel plasma chamber) and with the same plasma chamber with the radial wall covered by a highly electron emissive MD liner that raise the plasma electron density and temperature. The charge state distributions of the argon ions extracted from the source show an important increase of the ion beam for the high charge states as compared to the standard situation whereas the low charge states are less reduced than in the case of the presence of a MD liner. Due to the special position of the dielectric layer, the MD electrode introduces a new effect, which is connected to its property of becoming a positively charged surface under electron and ion bombardment. The MD electrode creates a quasiconfinement of the peripheral ions in the extraction, those ions that are normally lost to a conducting extraction electrode.

Schachter, L.; Dobrescu, S.; Stiebing, K.E. [National Institute for Physics and Nuclear Engineering (IFIN-HH), P.O. Box MG-6, Bucharest (Romania); Institut fuer Kernphysik der Johann Wolfgang Goethe-Universitaet (IKF), Max-von-Laue-Strasse 1, D-60438 Frankfurt (Germany)

2006-03-15

7

Weak feature extraction of gear fault based on stochastic resonance denoising  

NASA Astrophysics Data System (ADS)

To solve the problem of feature extraction of weak gear fault under strong noise background, an early feature extraction method based on cascaded monostable stochastic resonance (CMSR) system and empirical mode decomposition (EMD) with teager energy operator demodulation was proposed. The model of monostable stochastic resonance expanded the processing range of characteristic frequency of the measured signal, and had a good effect on denoising performance by cascading. Firstly CMSR was employed as the preprocessor to remove noise, then the denoised signal was decomposed into a series of intrinsic mode functions (IMFs) of different scales by EMD, and finally teager energy operator demodulation was applied to obtain amplitudes and frequencies of each effective IMF to extract the weak gear fault feature. Simulation and application results showed that the proposed method could effectively detect the characteristic frequency of gear fault of local damage after the noise reduction by CMSR.

Zhao, Jun; Lai, Xin-huan; Kong, Ming; Guo, Tian-tai

2013-01-01

8

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

SciTech Connect

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

Sidorov, A.; Dorf, M.; Zorin, V.; Bokhanov, A.; Izotov, I.; Razin, S.; Skalyga, V.; Rossbach, J.; Spaedtke, P.; Balabaev, A. [Institute of Applied Physics, RAS, 46 Ulyanov St., 603950 Nizhny Novgorod (Russian Federation); Gesellschaft fur Schwerionenforschung (GSI), Planckstr. 1, 64291 Darmstadt (Germany); Institute for Theoretical and Experimental Physics, 25 B. Cheremushkinskaya St., 117259 Moscow (Russian Federation)

2008-02-15

9

Resonance extractions in the {alpha}+{sup 8}He slow scattering  

SciTech Connect

The {alpha}+{sup 8}He low-energy reactions and the exotic structures of {sup 12}Be={alpha}+{alpha}+4N are studied by the application of the generalized two-center cluster model. In the two-neutron transfer reactions, {alpha}+{sup 8}He{sub g.s.}{yields}{sup 6}He{sub g.s.}+{sup 6}He{sub g.s.}, resonant structures with a sharp width of {Gamma}<1 MeV appear in the central collision (J{sup {pi}=}0{sup +}). The reaction mechanism is analyzed, and we confirmed that the transfer coupling plays essential roles in the resonance formation with sharp width. Angular distributions for the scattered {sup 6}He are analyzed to extract resonant structures for individual partial waves. We found that, for the low-spin resonances, the angular selection around 90 deg. in the center-of-mass system, which is usually employed in the high-spin resonances of light-ion systems, is not necessarily appropriate to separate the resonance contribution with a definite spin. The validity of the selection angle around 90 deg. is discussed in the higher partial waves.

Ito, Makoto [Pure and Applied Physics, Kansai University, Yamate-cho 3-3-35, Suita 564-8680 (Japan); Research Center for Nuclear Physics (RCNP), Osaka University, Mihogaoka 10-1, Suita 567-0047 (Japan); RIKEN Nishina Center for Accelerator-based Science, RIKEN, Wako, 351-0198, Saitama (Japan); Suzuki, Daisuke [National Superconducting Cyclotron Laboratory, Michigan State University, 1 Cyclotron, East Lansing, Michigan 48824-1321 (United States)

2011-07-15

10

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

11

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

12

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

13

Extracting Information about the Rotator Cuff from Magnetic Resonance Images Using Deterministic and Random Techniques  

PubMed Central

We consider some methods to extract information about the rotator cuff based on magnetic resonance images; the study aims to define an alternative method of display that might facilitate the detection of partial tears in the supraspinatus tendon. Specifically, we are going to use families of ellipsoidal triangular patches to cover the humerus head near the affected area. These patches are going to be textured and displayed with the information of the magnetic resonance images using the trilinear interpolation technique. For the generation of points to texture each patch, we propose a new method that guarantees the uniform distribution of its points using a random statistical method. Its computational cost, defined as the average computing time to generate a fixed number of points, is significantly lower as compared with deterministic and other standard statistical techniques. PMID:25650281

De Los Ríos, F. A.; Paluszny, M.

2015-01-01

14

An Analysis Method for Superconducting Resonator Parameter Extraction with Complex Baseline Removal  

NASA Technical Reports Server (NTRS)

A new semi-empirical model is proposed for extracting the quality (Q) factors of arrays of superconducting microwave kinetic inductance detectors (MKIDs). The determination of the total internal and coupling Q factors enables the computation of the loss in the superconducting transmission lines. The method used allows the simultaneous analysis of multiple interacting discrete resonators with the presence of a complex spectral baseline arising from reflections in the system. The baseline removal allows an unbiased estimate of the device response as measured in a cryogenic instrumentation setting.

Cataldo, Giuseppe

2014-01-01

15

Extracting phase and amplitude modifications of laser-coupled Fano resonances.  

PubMed

Fano line shapes observed in absorption spectra encode information on the amplitude and phase of the optical dipole response. A change in the Fano line shape, e.g., by interaction with short-pulsed laser fields, allows us to extract dynamical modifications of the amplitude and phase of the coupled excited quantum states. We introduce and apply this physical mechanism to near-resonantly coupled doubly excited states in helium. This general approach provides a physical understanding of the laser-induced spectral shift of absorption-line maxima on a sub-laser-cycle time scale as they are ubiquitously observed in attosecond transient-absorption measurements. PMID:24679285

Kaldun, Andreas; Ott, Christian; Blättermann, Alexander; Laux, Martin; Meyer, Kristina; Ding, Thomas; Fischer, Andreas; Pfeifer, Thomas

2014-03-14

16

Extracting Phase and Amplitude Modifications of Laser-Coupled Fano Resonances  

NASA Astrophysics Data System (ADS)

Fano line shapes observed in absorption spectra encode information on the amplitude and phase of the optical dipole response. A change in the Fano line shape, e.g., by interaction with short-pulsed laser fields, allows us to extract dynamical modifications of the amplitude and phase of the coupled excited quantum states. We introduce and apply this physical mechanism to near-resonantly coupled doubly excited states in helium. This general approach provides a physical understanding of the laser-induced spectral shift of absorption-line maxima on a sub-laser-cycle time scale as they are ubiquitously observed in attosecond transient-absorption measurements.

Kaldun, Andreas; Ott, Christian; Blättermann, Alexander; Laux, Martin; Meyer, Kristina; Ding, Thomas; Fischer, Andreas; Pfeifer, Thomas

2014-03-01

17

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

18

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

NASA Astrophysics Data System (ADS)

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

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

2014-01-01

19

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

SciTech Connect

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

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

2012-02-15

20

Adaptive bistable stochastic resonance and its application in mechanical fault feature extraction  

NASA Astrophysics Data System (ADS)

Stochastic resonance (SR) is an important approach to detect weak vibration signals from heavy background noise. In order to increase the calculation speed and improve the weak feature detection performance, a new bistable model has been built. With this model, an adaptive and fast SR method based on dyadic wavelet transform and least square system parameters solving is proposed in this paper. By adding the second-order differential item into the traditional bistable model, noise utilization can be increased and the quality of SR output signal can be improved. The iteration algorithm for implementing the adaptive SR is given. Compared with the traditional adaptive SR method, this algorithm does not need to set up the searching range and searching step size of the system parameters, but only requires a few iterations. The proposed method, discrete wavelet transform and the traditional adaptive SR method are applied to analyzing simulated vibration signals and extracting the fault feature of a rotor system. The contrastive results verify the superiority of the proposed method, and it can be effectively applied to weak mechanical fault feature extraction.

Qin, Yi; Tao, Yi; He, Ye; Tang, Baoping

2014-12-01

21

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

22

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

23

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

SciTech Connect

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{sup ?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., E-mail: pradipr@barc.gov.in; Mishra, L.; Kewlani, H.; Mittal, K. C. [Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)] [Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Patil, D. S. [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)] [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

2014-03-15

24

Comparative Study on Finite Element Analysis & System Model Extraction for Non-Resonant 3DoF Microgyroscope  

Microsoft Academic Search

This paper reports a comparative study of full transient start up analysis of a Non-Resonant Micromachined Gyroscope using Finite Element Analysis (FEA) and System Model Extraction (SME) techniques. FEA is a popular numerical technique based on Finite Element Method (FEM) for carrying out different engineering analyses. But one of the major disadvantages of this FEA is its computational time. While

Rana I. Shakoor; Shafaat A. Bazaz; Y. Lai; M. M. Hasan

2008-01-01

25

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

26

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

SciTech Connect

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

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

1985-01-01

27

Simulations of Various Driving Mechanisms for the 3rd Order Resonant Extraction from the MedAustron Medical Synchrotron  

E-print Network

The MedAustron medical synchrotron is based on the CERN-PIMMS design and its technical implementation by CNAO [1]. This document elaborates on studies performed on the baseline betatron-core driven extraction method and investigates the feasibility of alternative resonance driving mechanisms like RF-knockout, RF-noise and the lattice tune. Single particle tracking results are presented, explained and compared to analytical results.

Feldbauer, G; Dorda, U

2011-01-01

28

Magnetic resonance imaging of nonaqueous phase liquid during soil vapor extraction in heterogeneous porous media.  

PubMed

Soil vapor extraction (SVE) is commonly used to remediate nonaqueous phase liquids (NAPLs) from the vadose zone. This paper 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 nondestructive, 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 microm) only, fine grains (32-63 microm) 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-grain or fine-grain silica gel. In the heterogeneous columns, the volatilization front in the core lagged just behind the shell because gas flow was greater through the shell and decane in the core diffused outward to the shell. When decane saturation in the core was above residual saturation, decane volatilization occurred near the inlet, the relative decane saturation throughout the core dropped uniformly, and decane in the core flowed in the liquid phase to the shell to replenish volatilized decane. These results indicate that NAPL trapped in low-permeability zones can flow to replenish areas where NAPL is lost due to SVE. However, when residual NAPL saturation is reached, NAPL flow no longer occurs and diffusion limits removal from low-permeability zones. PMID:15336788

Chu, Yanjie; Werth, Charles J; Valocchi, Albert J; Yoon, Hongkyu; Webb, Andrew G

2004-09-01

29

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

PubMed

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

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

2012-02-01

30

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

31

Resonance  

NSDL National Science Digital Library

All About Circuits is a website that â??provides 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.

32

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

33

Automatic bone segmentation and bone-cartilage interface extraction for the shoulder joint from magnetic resonance images  

NASA Astrophysics Data System (ADS)

We present a statistical shape model approach for automated segmentation of the proximal humerus and scapula with subsequent bone-cartilage interface (BCI) extraction from 3D magnetic resonance (MR) images of the shoulder region. Manual and automated bone segmentations from shoulder MR examinations from 25 healthy subjects acquired using steady-state free precession sequences were compared with the Dice similarity coefficient (DSC). The mean DSC scores between the manual and automated segmentations of the humerus and scapula bone volumes surrounding the BCI region were 0.926? ± ?0.050 and 0.837? ± ?0.059, respectively. The mean DSC values obtained for BCI extraction were 0.806? ± ?0.133 for the humerus and 0.795? ± ?0.117 for the scapula. The current model-based approach successfully provided automated bone segmentation and BCI extraction from MR images of the shoulder. In future work, this framework appears to provide a promising avenue for automated segmentation and quantitative analysis of cartilage in the glenohumeral joint.

Yang, Zhengyi; Fripp, Jurgen; Chandra, Shekhar S.; Neubert, Aleš; Xia, Ying; Strudwick, Mark; Paproki, Anthony; Engstrom, Craig; Crozier, Stuart

2015-02-01

34

Automatic bone segmentation and bone-cartilage interface extraction for the shoulder joint from magnetic resonance images.  

PubMed

We present a statistical shape model approach for automated segmentation of the proximal humerus and scapula with subsequent bone-cartilage interface (BCI) extraction from 3D magnetic resonance (MR) images of the shoulder region. Manual and automated bone segmentations from shoulder MR examinations from 25 healthy subjects acquired using steady-state free precession sequences were compared with the Dice similarity coefficient (DSC). The mean DSC scores between the manual and automated segmentations of the humerus and scapula bone volumes surrounding the BCI region were 0.926? ± ?0.050 and 0.837? ± ?0.059, respectively. The mean DSC values obtained for BCI extraction were 0.806? ± ?0.133 for the humerus and 0.795? ± ?0.117 for the scapula. The current model-based approach successfully provided automated bone segmentation and BCI extraction from MR images of the shoulder. In future work, this framework appears to provide a promising avenue for automated segmentation and quantitative analysis of cartilage in the glenohumeral joint. PMID:25611124

Yang, Zhengyi; Fripp, Jurgen; Chandra, Shekhar S; Neubert, Aleš; Xia, Ying; Strudwick, Mark; Paproki, Anthony; Engstrom, Craig; Crozier, Stuart

2015-02-21

35

Energy Extraction in Idealized Models of Global and Regional Tides: Effects of Boundary Conditions and Tidal Resonance  

NASA Astrophysics Data System (ADS)

Ocean tide is generated by astronomical processes at the global scale. However, most regional models of marine hydrodynamics have tides imposed at the edge of the model domain as boundary conditions, and often omit local tide-generating force. This introduces uncertainties into results of regional models when used in tidal energy applications, because a regional model cannot represent a complete energetics of the tide unambiguously. We have set up a highly idealized model of a global ocean-estuary system, in which tides are forced astronomically and thus the integrated energy balance is complete and unambiguous; and a suite of subdomain models forced by tides sampled from the global model. We use both models to perform experiments simulating tidal energy extraction, where locally enhanced quadratic drag is used to mimic the effect of a tidal energy array. We consider the physical limit of extraction and effects on the estuarine tide, and how these compare in regional models with the global model. Previous experiments showed that tidal response to energy extraction is sensitive to the configuration of the subdomain model, and that adding local tide-generating force to the subdomain model leads to small but significant improvement in the agreement of results with the full domain model. In this study, we investigate the effects of various commonly-used boundary conditions for regional models on extraction limit and tidal regime change. We also consider a case in which the estuary is extended to become nearly quarter-wave resonant with the semi-diurnal tide, in which case local source of energy from astronomical forcing is expected to be more prominent.

Kawase, M.; Gedney, M.

2012-12-01

36

A femtogram resolution mass sensor platform, based on SOI electrostatically driven resonant cantilever. Part I: electromechanical model and parameter extraction.  

PubMed

A microcantilever based platform for mass detection in the femtogram range has been integrated in the doped top silicon layer of a SOI substrate. The on-plane fundamental resonance mode of the cantilever is excited electrostatically and detected capacitively by means of two parallel placed electrodes in a two port configuration. An electromechanical model of the cantilever-electrodes transducer and its implementation in a SPICE environment are presented. The model takes into account non-linearities from variable cantilever-electrode gap, fringing field contributions and real deflection shape of the cantilever for the calculation of the driving electrostatic force. A fitting of the model to the measured S(21) transmitted power frequency response is performed to extract the characteristic sensor parameters as Young modulus, Q factor, electrical parasitics and mass responsivity. PMID:16675119

Teva, J; Abadal, G; Torres, F; Verd, J; Pérez-Murano, F; Barniol, N

2006-01-01

37

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

SciTech Connect

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

Hiroyuki Kamano

2012-04-01

38

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

39

Metabonomic analysis of water extracts from different angelica roots by ¹H-nuclear magnetic resonance spectroscopy.  

PubMed

Angelica Radix, the roots of the genus Angelica, has been used for more than 2,000 years as a traditional medicine in Eastern Asia. The Chinese Pharmacopoeia records more than 100 herbal formulae containing Angelica roots. There are two common sources of Angelica roots, Angelica sinensis from China and A. gigas from Korea. The two species of Angelica roots differ in their chemical compositions, pharmacological properties and clinical efficacy. ¹H-NMR metabolic profiling has recently emerged as a promising quality control method for food and herbal chemistry. We explored the use of ¹H-NMR metabolic profiling for the quality control of Angelica Radix. Unlike previous work, we performed the metabolic profiling on hot water extracts, so as to mimic the clinically relevant preparation method. Unsupervised principle component analyses of both the full spectral profile and a selection of targeted molecules revealed a clear differentiation of three types of Angelica roots. In addition, the levels of 13 common metabolites were measured. Statistically significant differences in the levels of glucose, fructose and threonine were found between different sources of Angelica. Ferulic acid, a marker commonly used to evaluate Angelica root, was detected in our samples, but the difference in ferulic acid levels between the samples was not statistically significant. Overall, we successfully applied ¹H-NMR metabolic profiling with water extraction to discriminate all three sources of Angelica roots, and obtained quantitative information of many common metabolites. PMID:24658570

Chan, Pui Hei; Zhang, Wendy L; Lau, Chung-Ho; Cheung, Chi Yuen; Keun, Hector C; Tsim, Karl W K; Lam, Henry

2014-01-01

40

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

41

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

42

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

43

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

44

Identification and Quantitation of Phosphorus Metabolites in Yeast Neutral pH Extracts by Nuclear Magnetic Resonance Spectroscopy  

Microsoft Academic Search

31P NMR spectroscopy offers a possibility to obtain a survey of all low-molecular-weight phosphorylated compounds in yeast. The yeast cells have been extracted using chloroform into a neutral aqueous phase. The use of high fields and the neutral pH extracts, which are suitable for NMR analysis, results in well-resolved 31P NMR spectra. Two-dimensional NMR experiments, such as proton-detected heteronuclear single

Anita Teleman; Peter Richard; Mervi Toivari; Merja Penttilä

1999-01-01

45

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

46

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

E-print Network

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

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

2008-04-25

47

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

48

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

NASA Astrophysics Data System (ADS)

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 H{{e}+} 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; Lugan, Pierre; Jörder, Felix; Heitz, Nicolai; Schmidt, Maximilian; Bouri, Celsus; Rodriguez, Alberto; Buchleitner, Andreas

2015-01-01

49

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

50

1H nuclear magnetic resonance spectra of chloroform extracts of honey for chemometric determination of its botanical origin.  

PubMed

In this work, we present a new NMR study, coupled with chemometric analysis, on nonvolatile organic honey components. The extraction method is simple and reproducible. The 1H NMR spectra of chloroform extracts acquired with a fast and new pulse sequence were used to characterize and differentiate by chemometric analysis 118 honey samples of four different botanical origins (chestnut, acacia, linden, and polyfloral). The spectra collection, processing, and analysis require only 30 min. The 1H spectrum provides a fingerprint for each honey type, showing many characteristic peaks in all spectral regions. Principal component analysis (PCA) and projection to latent structures by partial least squares-discriminant analysis (PLS-DA) were performed on selected signals of the spectra to discriminate the different botanical types and to identify characteristic metabolites for each honey type. A distinct discrimination among samples was achieved. According to the distance to model criterion, there was no overlap between the four models, which proved to be specific for each honey type. The PLS-DA model obtained has a correlation coefficient R2 of 0.67 and a validation correlation coefficient Q2 of 0.77. The discriminant analysis allowed us to classify correctly 100% of the samples. A classification index can be calculated and used to determine the floral origin of honey as an alternative to the melissopalinology test and possibly to determine the percentage of various botanical species in polyfloral samples. Preliminary data on the identification of marker compounds for each botanical origin are presented. PMID:19938861

Schievano, Elisabetta; Peggion, Evaristo; Mammi, Stefano

2010-01-13

51

Reaction product analysis by high-performance liquid chromatography-solid-phase extraction-nuclear magnetic resonance Application to the absolute configuration determination of naturally occurring polyyne alcohols.  

PubMed

The absolute configuration of secondary hydroxy functions of seven natural occurring polyyne derivatives has been elucidated by the application of Mosher method of diastereomeric methoxy-2-trifluoromethyl-phenylacetyl (MTPA) ester formation. High-performance liquid chromatography with diode array detection (HPLC-DAD) of the reaction mixture using a water/acetonitrile gradient allowed monitoring the reaction progress. Coupling of high-performance liquid chromatography to solid-phase extraction combined with nuclear magnetic resonance (HPLC-SPE-NMR) was utilized to generate highly reproducible (1)H and (19)F NMR data needed as input for the absolute configuration determination based on the analysis of relative shift differences. Chromatographic peaks of reaction substrates and reaction products bearing less 10mug analyte were trapped on SPE cartridges with the aid of water as makeup solvent. Deuterated chloroform was used to elute and transfer the peak content from the SPE to the 60mul flow cell of a 500MHz NMR spectrometer. For each analyte (1)H NMR spectra were obtained within 15min. Additionally (19)F NMR spectra were recorded for selected analytes in the same timeframe. Based on the obtained NMR data, the absolute configuration of all polyynes under investigation was successfully designated. PMID:17027010

Seger, Christoph; Godejohann, Markus; Spraul, Manfred; Stuppner, Hermann; Hadacek, Franz

2006-12-01

52

Direct proof by 13C-nuclear magnetic resonance of semi-purified extract and isolation of ent-Catechin from leaves of Eucalyptus cinerea  

PubMed Central

Background: Eucalyptus cinerea F. Muell. ex Benth. is native to Australia and acclimatized to Southern Brazil. Its aromatic leaves are used for ornamental purposes and have great potential for essential oil production, although reports of its use in folk medicine are few. Objective: This study evaluated the composition of E. cinerea leaves using the solid state 13C-nuclear magnetic resonance (NMR) and isolation of the compound from the semipurified extract (SE). Materials and Methods: The SE of E. cinerea leaves was evaluated in the solid state by 13C-NMR spectrum, and the SE was chromatographed on a Sephadex LH-20 column, followed by high-speed counter-current chromatography to isolate the compound. The SE was analyzed by 13C-NMR and matrix-assisted laser desorption/ionization-time-of-flight spectra. Results: Flavan-3-ol units were present, suggesting the presence of proanthocyanidins as well as a gallic acid unit. The uncommon ent-catechin was isolated. Conclusion: The presence of ent-catechin is reported for the first time in this genus and species. PMID:25210302

Silva, Sayonara Mendes; Abe, Simone Yae; Bueno, Fernanda Giacomini; Lopes, Norberto Peporine; de Mello, João Carlos Palazzo; Nakashima, Tomoe

2014-01-01

53

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

PubMed

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

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

2006-04-21

54

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

55

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

SciTech Connect

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

Kishii, Y., E-mail: Ando.Yasuto@ct.MitsubishiElectric.co.jp; Kawasaki, S. [Energy Systems Center, Mitsubishi Electric Corporation, 1-1-2 Wadasaki-cho, Hyogo-ku, Kobe 652-8555 (Japan)] [Energy Systems Center, Mitsubishi Electric Corporation, 1-1-2 Wadasaki-cho, Hyogo-ku, Kobe 652-8555 (Japan); Kitagawa, A.; Muramatsu, M. [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan)] [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan); Uchida, T. [Bio-Nano Electronics Research Center, Toyo University, 2100 Kujirai, Kawagoe 350-8585 (Japan) [Bio-Nano Electronics Research Center, Toyo University, 2100 Kujirai, Kawagoe 350-8585 (Japan); Graduate School of Interdisciplinary New Science, Toyo University, 2100 Kujirai, Kawagoe 350-8585 (Japan)

2014-02-15

56

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

57

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

58

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

PubMed

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

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

2010-04-23

59

Feshbach Resonances in Ultracold Gases  

NASA Astrophysics Data System (ADS)

In this chapter, we describe scattering resonance phenomena in general, and focus on the mechanism of Feshbach resonances, for which a multi-channel treatment is required. We derive the dependence of the scattering phase shift on magnetic field and collision energy. From this, the scattering length and effective range coefficient can be extracted -- expressions which are particularly useful for ultracold gases.

Kokkelmans, Servaas

2015-09-01

60

Optical resonator  

NASA Technical Reports Server (NTRS)

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

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

2006-01-01

61

Contour extraction from cardiac MRI studies using snakes  

Microsoft Academic Search

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

Surendra Ranganath

1995-01-01

62

Dark resonance  

SciTech Connect

We construct explicit models of particle dark matter where the attractive force in the dark matter sector creates a narrow near-threshold resonance that qualitatively changes the energy dependence of the annihilation cross section. In these models, the resonant enhancement of the dark matter annihilation can easily source the excess of energetic leptons observed by the PAMELA experiment. The distinct feature of these models is that by construction the enhancement of the annihilation cross section shuts off when the dark matter velocity falls below the typical Milky Way values, thus automatically satisfying constraints on dark matter annihilation imposed by the CMB anisotropies and gamma ray constraints from satellite galaxies. However, the resonant enhancement of annihilation can be probed through the most recent FERMI-LAT constraints on the diffuse galactic gamma ray emission.

An, Haipeng; Pospelov, Maxim, E-mail: han@perimeterinstitute.ca, E-mail: mpospelov@perimeterinstitute.ca [Perimeter Institute for Theoretical Physics, Waterloo, ON, N2J 2W9 (Canada)

2012-11-01

63

Tooth Extraction  

MedlinePLUS

... loosens the tooth with an instrument called an elevator. Then the dentist uses an instrument called a ... difficult extractions. Smokers and women who take birth control pills are more likely to have a dry ...

64

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).

2012-06-26

65

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

66

Bevalac extraction  

SciTech Connect

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

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

1992-02-01

67

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

68

Resonant behavior of dielectric objects (electrostatic resonances).  

PubMed

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

Fredkin, D R; Mayergoyz, I D

2003-12-19

69

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

70

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

71

All-Resonant Control of Superconducting Resonators  

E-print Network

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

Frederick W. Strauch

2012-08-17

72

Resonance-assisted decay of nondispersive wave packets  

E-print Network

We present a quantitative semiclassical theory for the decay of nondispersive electronic wave packets in driven, ionizing Rydberg systems. Statistically robust quantities are extracted combining resonance assisted tunneling with subsequent transport across chaotic phase space and a final ionization step.

Sandro Wimberger; Peter Schlagheck; Christopher Eltschka; Andreas Buchleitner

2006-07-17

73

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.

74

Detection of Kestoses and Kestose-Related Oligosaccharides in Extracts of Festuca arundinacea, Dactylis glomerata L., and Asparagus officinalis L. Root Cultures and Invertase by 13C and 1H Nuclear Magnetic Resonance Spectroscopy 1  

PubMed Central

A previous study (KL Forsythe, MS Feather [1989] Carbohydr Res 185: 315-319) showed that 13C 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 glomerata 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. PMID:16667365

Forsythe, Kathlene L.; Feather, Milton S.; Gracz, Hanna; Wong, Tuck C.

1990-01-01

75

Resonant Nucleation  

E-print Network

We investigate the role played by fast quenching on the decay of metastable (or false vacuum) states. Instead of the exponentially-slow decay rate per unit volume, $\\Gamma_{\\rm HN} \\sim \\exp[-E_b/k_BT]$ ($E_b$ is the free energy of the critical bubble), predicted by Homogeneous Nucleation theory, we show that under fast enough quenching the decay rate is a power law $\\Gamma_{\\rm RN} \\sim [E_b/k_BT]^{-B}$, where $B$ is weakly sensitive to the temperature. For a range of parameters, large-amplitude oscillations about the metastable state trigger the resonant emergence of coherent subcritical configurations. Decay mechanisms for different $E_b$ are proposed and illustrated in a (2+1)-dimensional scalar field model.

Marcelo Gleiser; Rafael Howell

2005-03-16

76

Magnetic Resonance Imaging in Endodontic Treatment Prediction  

Microsoft Academic Search

The necessary condition for successful endodontic treatment is the precise mapping of the shape of dental cavities. The aim of this work has been an elaboration and verification of the possibility of using three-dimensional (3D) spin echo magnetic resonance imaging (MRI) techniques in dentistry. Six extracted molar teeth were used for measurements without additional preparation and after endodontic preparation. MRI

Marta Tanasiewicz

2010-01-01

77

Experiments with Helmholtz Resonators.  

ERIC Educational Resources Information Center

Presents experiments that use Helmholtz resonators and have been designed for a sophomore-level course in oscillations and waves. Discusses the theory of the Helmholtz resonator and resonance curves. (JRH)

Greenslade, Thomas B., Jr.

1996-01-01

78

Regenerative feedback resonant circuit  

DOEpatents

A regenerative feedback resonant circuit for measuring a transient response in a loop is disclosed. The circuit includes an amplifier for generating a signal in the loop. The circuit further includes a resonator having a resonant cavity and a material located within the cavity. The signal sent into the resonator produces a resonant frequency. A variation of the resonant frequency due to perturbations in electromagnetic properties of the material is measured.

Jones, A. Mark; Kelly, James F.; McCloy, John S.; McMakin, Douglas L.

2014-09-02

79

Relation Extraction from Wikipedia Text Relation Extraction  

E-print Network

Relation Extraction from Wikipedia Text Relation Extraction from Wikipedia Text Wikipedia Mining Seminar Universität des Saarlandes Miriam Käshammer January 18, 2010 #12;Relation Extraction from Wikipedia Text Introduction Outline Introduction PORE: Positive-Only Relation Extraction from Wikipedia Text

Neumann, Günter

80

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

81

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

Microsoft Academic Search

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

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

2008-01-01

82

Analysis and calibration techniques for superconducting resonators.  

PubMed

A method is proposed and experimentally explored for in-situ calibration of complex transmission data for superconducting microwave resonators. This cryogenic calibration method accounts for the instrumental transmission response between the vector network analyzer reference plane and the device calibration plane. Once calibrated, the observed resonator response is analyzed in detail by two approaches. The first, a phenomenological model based on physically realizable rational functions, enables the extraction of multiple resonance frequencies and widths for coupled resonators without explicit specification of the circuit network. In the second, an ABCD-matrix representation for the distributed transmission line circuit is used to model the observed response from the characteristic impedance and propagation constant. When used in conjunction with electromagnetic simulations, the kinetic inductance fraction can be determined with this method with an accuracy of 2%. Datasets for superconducting microstrip and coplanar-waveguide resonator devices were investigated and a recovery within 1% of the observed complex transmission amplitude was achieved with both analysis approaches. The experimental configuration used in microwave characterization of the devices and self-consistent constraints for the electromagnetic constitutive relations for parameter extraction are also presented. PMID:25638068

Cataldo, Giuseppe; Wollack, Edward J; Barrentine, Emily M; Brown, Ari D; Moseley, S Harvey; U-Yen, Kongpop

2015-01-01

83

Analysis and calibration techniques for superconducting resonators  

NASA Astrophysics Data System (ADS)

A method is proposed and experimentally explored for in-situ calibration of complex transmission data for superconducting microwave resonators. This cryogenic calibration method accounts for the instrumental transmission response between the vector network analyzer reference plane and the device calibration plane. Once calibrated, the observed resonator response is analyzed in detail by two approaches. The first, a phenomenological model based on physically realizable rational functions, enables the extraction of multiple resonance frequencies and widths for coupled resonators without explicit specification of the circuit network. In the second, an ABCD-matrix representation for the distributed transmission line circuit is used to model the observed response from the characteristic impedance and propagation constant. When used in conjunction with electromagnetic simulations, the kinetic inductance fraction can be determined with this method with an accuracy of 2%. Datasets for superconducting microstrip and coplanar-waveguide resonator devices were investigated and a recovery within 1% of the observed complex transmission amplitude was achieved with both analysis approaches. The experimental configuration used in microwave characterization of the devices and self-consistent constraints for the electromagnetic constitutive relations for parameter extraction are also presented.

Cataldo, Giuseppe; Wollack, Edward J.; Barrentine, Emily M.; Brown, Ari D.; Moseley, S. Harvey; U-Yen, Kongpop

2015-01-01

84

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

85

Integral resonator gyroscope  

NASA Technical Reports Server (NTRS)

The present invention discloses an inertial sensor having an integral resonator. A typical sensor comprises a planar mechanical resonator for sensing motion of the inertial sensor and a case for housing the resonator. The resonator and a wall of the case are defined through an etching process. A typical method of producing the resonator includes etching a baseplate, bonding a wafer to the etched baseplate, through etching the wafer to form a planar mechanical resonator and the wall of the case and bonding an end cap wafer to the wall to complete the case.

Shcheglov, Kirill V. (Inventor); Challoner, A. Dorian (Inventor); Hayworth, Ken J. (Inventor); Wiberg, Dean V. (Inventor); Yee, Karl Y. (Inventor)

2008-01-01

86

Optical Fano resonance of an individual semiconductor nanostructure  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

87

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

88

Neutron resonance averaging  

SciTech Connect

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

Chrien, R.E.

1986-10-01

89

Phase I ResonantSonic CRADA report  

SciTech Connect

This test report describes the Phase 1 testing and results of the ResonantSonic drilling method. This effort was conducted as part of a Cooperative Research and Development Agreement (CRADA) between the US Department of Energy, Pacific Northwest Laboratory, Westinghouse Hanford Company and Water Development Corporation. The purpose of this demonstration was to evaluate the Water Development Corporation`s ResonantSonic drilling system, modify components as necessary and determine compatible drilling applications for the ResonantSonic drilling method for use at facilities in the DOE complex and private industry. Initially, the ResonantSonic drill was used to drill several test holes at the Drilling Technology Test Site to assess the feasibility of drilling vertical and angle holes. After this initial phase, a 45 degree angle vapor extraction well was drilled to a depth of 168 feet at the 200 West Carbon Tetrachloride Site. This well was drilled and completed in nine days. Extensive geologic and vapor sampling were conducted while drilling this well. In addition, testing was also conducted at the test site to evaluated drilling with larger diameter casing (8 5/8 inch). Evaluation of the Resonant Sonic drilling method will be continued during the Phase 2 portion of testing to determine if improvements to the ResonantSonic system will make it a more viable method for drilling and sampling.

Richterich, L.R.; Amos, L.O.; Fancher, J.D.; McLellan, G.W.; Setzer, W.V.; Tuttle, B.G. [Westinghouse Hanford Co., Richland, WA (United States); Hockey, R.L.; Ferris, R.H.; Riechers, D.M.; Pitman, S.G. [Pacific Northwest Lab., Richland, WA (United States)

1994-03-28

90

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

91

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

92

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

93

Ovenized microelectromechanical system (MEMS) resonator  

DOEpatents

An ovenized micro-electro-mechanical system (MEMS) resonator including: a substantially thermally isolated mechanical resonator cavity; a mechanical oscillator coupled to the mechanical resonator cavity; and a heating element formed on the mechanical resonator cavity.

Olsson, Roy H; Wojciechowski, Kenneth; Kim, Bongsang

2014-03-11

94

Resonance neutron capture in 136Ba  

NASA Astrophysics Data System (ADS)

The neutron capture cross section of 136Ba, which was determined recently with the Karlsruhe 4? barium fluoride detector, has been reanalyzed in the low energy region using a shape analysis program. Parameters of 45 resonances were extracted which allow a more reliable determination of the averaged cross section below 20 keV. The results confirm our first analysis and the reported stellar cross sections. Accordingly, the results of the s-process studies based on these data remain unchanged.

Voss, F.; Wisshak, K.; Käppeler, F.

1995-08-01

95

Secular resonances. [of asteroidal dynamics  

NASA Technical Reports Server (NTRS)

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

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

1989-01-01

96

Acoustic wave flow sensor using quartz thickness shear mode resonator.  

PubMed

A quartz thickness shear mode (TSM) bulk acoustic wave resonator was used for in situ and real-time detection of liquid flow rate in this study. A special flow chamber made of 2 parallel acrylic plates was designed for flow measurement. The flow chamber has a rectangular flow channel, 2 flow reservoirs for stabilizing the fluid flow, a sensor mounting port for resonator holding, one inlet port, and one outlet port for pipe connection. A 5-MHz TSM quartz resonator was edge-bonded to the sensor mounting port with one side exposed to the flowing liquid and other side exposed to air. The electrical impedance spectra of the quartz resonator at different volumetric flow rate conditions were measured by an impedance analyzer for the extraction of the resonant frequency through a data-fitting method. The fundamental, 3rd, 5th, 7th, and 9th resonant frequency shifts were found to be around 920, 3572, 5947, 8228, and 10,300 Hz for flow rate variation from 0 to 3000 mL/min, which had a corresponding Reynolds number change from 0 to 822. The resonant frequency shifts of different modes are found to be quadratic with flow rate, which is attributed to the nonlinear effect of quartz resonator due to the effective normal pressure imposing on the resonator sensor by the flowing fluid. The results indicate that quartz TSM resonators can be used for flow sensors with characteristics of simplicity, fast response, and good repeatability. PMID:19811997

Qin, Lifeng; Zeng, Zijing; Cheng, Hongbin; Wang, Qing-Ming

2009-09-01

97

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

98

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

99

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

100

The Delta-resonance in a finite volume  

E-print Network

We study the extraction of Delta-resonance parameters from lattice data for small quark masses, corresponding to the case of an unstable Delta. To this end, we calculate the spectrum of the correlator of two Delta-fields in a finite Euclidian box up-to-and-including O(epsilon^3) in the small scale expansion using infrared regularization. On the basis of our numerical study, we argue that the extraction of the parameters of the Delta-resonance (in particular, of the mass and the pion-nucleon-delta coupling constant) from the measured volume dependence of the lowest energy levels should be feasible.

Véronique Bernard; Ulf-G. Meißner; Akaki Rusetsky

2007-02-07

101

In Situ Root System Architecture Extraction from Magnetic Resonance  

E-print Network

grown in natural sand with a resolution of 0.39 Ã? 0.39 Ã? 1.1 mm. The automated reconstruction algorithm system architecture (RSA) is a crucial plant component of productivity: plant resistance to drought stress, nutrient acquisition and plant yield are strongly influenced by the plant's capacity

Behnke, Sven

102

Resonant elastic light scattering and coherence relaxation in semiconductor structures  

NASA Astrophysics Data System (ADS)

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

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

1996-06-01

103

Substrate effects on terahertz metamaterial resonances for various metal thicknesses  

NASA Astrophysics Data System (ADS)

We demonstrate dielectric substrate effects on the resonance shift of terahertz metamaterials with various metal thicknesses by using finite-difference time-domain simulations. We found a small red shift in the metamaterial resonance with increasing metal thickness for the free-standing case. Conversely, when the metamaterial pattern was supported by a substrate with a high dielectric constant, the resonant frequency exhibited a large blue shift because the relative contribution of the substrate's refractive index to the resonant frequency decreased drastically as we increased the metal thickness. We determined the substrate's refractive index, 1.26, at which the metamaterial resonance was independent of the metal thickness. We extracted the effective refractive index as a function of the substrate's refractive index explicitly, which was noticeably different for different film thicknesses.

Park, S. J.; Ahn, Y. H.

2014-12-01

104

Resonances on hedgehog manifolds  

E-print Network

We discuss resonances for a nonrelativistic and spinless quantum particle confined to a two- or three-dimensional Riemannian manifold to which a finite number of semiinfinite leads is attached. Resolvent and scattering resonances are shown to coincide in this situation. Next we consider the resonances together with embedded eigenvalues and ask about the high-energy asymptotics of such a family. For the case when all the halflines are attached at a single point we prove that all resonances are in the momentum plane confined to a strip parallel to the real axis, in contrast to the analogous asymptotics in some metric quantum graphs; we illustrate it on several simple examples. On the other hand, the resonance behaviour can be influenced by a magnetic field. We provide an example of such a `hedgehog' manifold at which a suitable Aharonov-Bohm flux leads to absence of any true resonance, i.e. that corresponding to a pole outside the real axis.

Pavel Exner; Jiri Lipovsky

2013-02-21

105

Mistletoe Extracts (PDQ)  

MedlinePLUS

... Trials Cancer Statistics Research & Funding News About NCI Mistletoe Extracts (PDQ®) Patient Version Health Professional Version Last Modified: 02/20/2014 Mistletoe Extracts (PDQ®) Overview Questions and Answers About Mistletoe ...

106

PITFALLS OF SEQUENTIAL EXTRACTION  

EPA Science Inventory

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

107

Endovascular extraction techniques  

PubMed Central

The use of lead extraction is expanding with the introduction of new endovascular extraction techniques. Indications for extraction of chronically implanted pacemaker leads have been classified as mandatory, necessary or discretionary, but their rationale is often based on clinical judgement without corresponding support from the literature. We reviewed the literature of pacemaker lead-related complications as a starting point for discussing the indications for lead extraction. ImagesFigure 1Figure 2Figure 3

Bracke, F.A.; Meijer, A.; van Gelder, B.

2001-01-01

108

Threshold voltage extraction circuit  

E-print Network

Vosz. . 22 23 A detailed schematic of the improved NMOS Vr extraction circuit. . . . . . . . . . . . . . . . . . 21 Fig. 15. Improved PMOS Vz extraction circuit. . 24 Fig. 16. Graph of i//n and r)(z/fn)/r)(Vos) versus Vos of a NMOS transistor... of DUT. . . . . . , . . . , 118 LIST OF TABLES Page Table I A comparison of Vr extraction techniques . Table 2 Component dimensions for improved NMOS Vr extraction circuit. . . . . . . . . . . . . . Table 3 Component dimensions for improved PMOS Vr...

Hoon, Siew Kuok

2012-06-07

109

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

110

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

111

Information extraction system  

DOEpatents

An information extraction system and methods of operating the system are provided. In particular, an information extraction system for performing meta-extraction of named entities of people, organizations, and locations as well as relationships and events from text documents are described herein.

Lemmond, Tracy D; Hanley, William G; Guensche, Joseph Wendell; Perry, Nathan C; Nitao, John J; Kidwell, Paul Brandon; Boakye, Kofi Agyeman; Glaser, Ron E; Prenger, Ryan James

2014-05-13

112

Photoluminescence measurements of quantum-dot-containing semiconductor microdisk resonators using optical fiber taper waveguides  

E-print Network

Photoluminescence measurements of quantum-dot-containing semiconductor microdisk resonators using for injecting pump light into and extracting the light emitted by semiconductor quantum dots into microdisk photoluminescence measurements of AlGaAs microdisk resonant cavities with embedded self-assembled InAs quantum dots

New Mexico, University of

113

Resonant control of solitons  

NASA Astrophysics Data System (ADS)

It is shown that the effect of “scattering on resonance” can be used to control envelope solitons in the driven nonlinear Schrödinger equation. The control occurs by the frequency modulated driving with multiple crossing of the resonant frequency of the soliton.

Batalov, S. V.; Shagalov, A. G.

2013-05-01

114

Nanoengineering of optical resonances  

Microsoft Academic Search

Metal nanoshells, consisting of a dielectric core with a metallic shell of nanometer thickness, are a new, composite nanoparticle whose optical resonance can be “designed in” in a controlled manner. By varying the relative dimensions of the core and shell, the optical resonance of these nanoparticles can be varied over hundreds of nanometers in wavelength, across the visible and into

S. J. Oldenburg; R. D. Averitt; S. L. Westcott; N. J. Halas

1998-01-01

115

Nuclear Quadrupole Resonance  

Microsoft Academic Search

Nuclear quadrupole resonance is a recently developed branch of radio-frequency spectroscopy which is concerned with magnetic resonance absorption in crystals. This absorption is due to reorientation of the nonspherical atomic nuclei against crystalline electric fields. Related phenomena in isolated molecules are briefly mentioned in the Introduction A. This is followed in Sec. B by an elementary treatment of the electrostatic

H. G. Dehmelt

1954-01-01

116

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

117

The resonator handbook  

NASA Technical Reports Server (NTRS)

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

Cook, Jerry D.; Zhou, Shiliang

1993-01-01

118

MEMS resonator temperature compensation  

Microsoft Academic Search

This paper presents the study of an electromechanical resonator temperature compensation principle. It consists in the use of a coating material presenting opposite properties over temperature compared to the silicon resonator structural material. Simulated results, using the FEM Coventor® software, show the great potential of this CMOS compatible principle for industrial perspectives.

F. Casset; C. Durand; Y. Civet; E. Ollier; J. F. Carpentier; P. Ancey; P. Robert

2010-01-01

119

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

120

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

121

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

122

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

123

Resonance-assisted decay of nondispersive wave packets.  

PubMed

We present a quantitative semiclassical theory for the decay of nondispersive electronic wave packets in driven, ionizing Rydberg systems. Statistically robust quantities are extracted combining resonance-assisted tunneling with subsequent transport across chaotic phase space and a final ionization step. PMID:16907569

Wimberger, Sandro; Schlagheck, Peter; Eltschka, Christopher; Buchleitner, Andreas

2006-07-28

124

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

125

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

126

Analysis of Glucose Concentration in Interstitial Fluid by Micro Surface Plasmon Resonance Sensor  

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

Dachao Li; Xian Huang; Haixia Yu; Xiaotang Hu; Kexin Xu; Robert C Roberts; Norman Tien

2007-01-01

127

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

E-print Network

Structure 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 of model wood extractive colloids composed of a resin acid (abietic acid), a fatty acid (oleic acid

Turro, Nicholas J.

128

A Novel Minimally Invasive Method to Detect Glucose Concentration without Blood Extraction  

Microsoft Academic Search

A novel minimally invasive way to measure the diabetic's real-time blood glucose concentration in vitro is proposed by combining interstitial fluid transdermal extraction ultrasonically and surface plasma resonance detecting. Low-frequency ultrasound is employed to enhance the skin permeability to interstitial fluid by disrupting the stratum corneum lipid bilayers and then interstitial fluid is extracted out of skin successfully by vacuum.

Dachao Li; Xian Huang; Haixia Yu; Zengfii Zhang; Fuxiang Huang; Kexin Xu; Xiaotang Hu

2006-01-01

129

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

130

Resonant optical antennas.  

PubMed

We have fabricated nanometer-scale gold dipole antennas designed to be resonant at optical frequencies. On resonance, strong field enhancement in the antenna feed gap leads to white-light supercontinuum generation. The antenna length at resonance is considerably shorter than one-half the wavelength of the incident light. This is in contradiction to classical antenna theory but in qualitative accordance with computer simulations that take into account the finite metallic conductivity at optical frequencies. Because optical antennas link propagating radiation and confined/enhanced optical fields, they should find applications in optical characterization, manipulation of nanostructures, and optical information processing. PMID:15947182

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

2005-06-10

131

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

132

Tunable multiwalled nanotube resonator  

DOEpatents

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

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

2011-03-29

133

Fuzzy wavelet packet based feature extraction method and its application to biomedical signal classification.  

PubMed

In this paper, we develop an efficient fuzzy wavelet packet (WP) based feature extraction method for the classification of high-dimensional biomedical data such as magnetic resonance spectra. The key design phases involve: 1) a WP transformation mapping the original signals to many WP feature spaces and finding optimal WP decomposition for signal classification; 2) feature extraction based on the optimal WP decomposition; and 3) signal classification realized by a linear classifier. In contrast to the standard method of feature extraction used in WPs, guided by the criteria of signal compression or signal energy, our method is used to extract discriminatory features from the WP coefficients of the optimal decomposition. The extraction algorithm constructs fuzzy sets of features (via fuzzy clustering) to assess their discriminatory effectiveness. This paper includes a number of numerical experiments using magnetic resonance spectra. Classification results are compared with those obtained from common feature extraction methods in the WP domain. PMID:15977743

Li, Deqiang; Pedrycz, Witold; Pizzi, Nicolino J

2005-06-01

134

Time scales in nuclear giant resonances  

E-print Network

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

WD Heiss; RG Nazmitdinov; FD Smit

2009-12-18

135

Fano resonances in prism-coupled multimode square micropillar resonators.  

PubMed

We report Fano resonances in a multimode square glass micropillar resonator; the resonances were obtained by using angle-resolved prism coupling. Our experiments reveal characteristically asymmetric line shapes of high-Q resonances and of detuned low-Q resonances in multimode reflection spectra. The asymmetric resonance line shapes evolve for an approximately pi phase within a 0.5 degree range of reflection angles. We model our observed asymmetric multimode resonances by the far-field interference between a light wave that is evanescently coupled with a high-Q mode orbit and a coherent light wave that is refractively coupled with a detuned low-Q mode orbit. PMID:16007796

Lee, Ho-Tong; Zhou, Linjie; Poon, Andrew W

2005-06-15

136

Resonances in Positronium Hydride  

NASA Technical Reports Server (NTRS)

We re-examine the problem of calculating the positions and widths of the lowest-lying resonances in the Ps + H scattering system which consists of two electrons, one positron and one proton. The first of these resonances, for L=0, was found by the methods of complex rotation and stabilization, and later described as a Feshbach resonance lying close to a bound state in the closed-channel e (+) + H (-) system. Recently, results for the L=1 and 2 scattering states were published, and it was found, surprisingly, that there is a larae shift in the positions of these resonances. In this work we repeat the analysis for L=1 and find an unexpected explanation for the shift.

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

2001-01-01

137

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

138

Validating resonance properties using nuclear resonance fluorescence  

NASA Astrophysics Data System (ADS)

Measurement of a resonance's integrated cross section using nuclear resonance fluorescence can be a valuable tool for verifying the properties of the resonance because of the clear and unambiguous physical connection to the spin, lifetime, and ground state branching ratio of the level. We demonstrate this idea by measuring the integrated cross section of the 3.004-MeV level in 27Al to 4% using the monoenergetic ? -ray beam at the High Intensity ? -ray Source. That level was the subject of much debate experimentally in the 1960s, especially its spin, and even now only has a current tentative spin assignment of J =(9 /2 ) . The consistency check between this integrated cross section and the known properties of the level indicate that one (or more) of the literature properties is incorrect. Based on the range of extent of each property, a reassignment of spin to a tentative J =(7 /2 ) may be warranted, but this would need to be confirmed with other measurements. This result demonstrates the utility of NRF as a way to verify the properties of states in the literature before undertaking more extensive measurements.

Angell, C. T.; Hajima, R.; Hayakawa, T.; Shizuma, T.; Karwowski, H. J.; Silano, J.

2014-11-01

139

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

SciTech Connect

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

Stefanie Lewis

2012-09-01

140

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

141

Injector with integrated resonator  

DOEpatents

The system may include a turbine engine. The turbine engine may include a fuel nozzle. The fuel nozzle may include an air path. The fuel nozzle may also include a fuel path such that the fuel nozzle is in communication with a combustion zone of the turbine engine. Furthermore, the fuel nozzle may include a resonator. The resonator may be disposed in the fuel nozzle directly adjacent to the combustion zone.

Johnson, Thomas Edward; Ziminsky, Willy Steve; York, William David; Stevenson, Christian Xavier

2014-07-29

142

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

143

Atomic resonance and scattering  

SciTech Connect

Experiments were conducted in the following areas: mapping of energy levels of a Rydberg lithium atom in a strong magnetic field in the vicinity of a crossing between levels from different principle quantum numbers, electrodynamics in a cavity, resonance enhanced multiphoton ionization, velocity dependence of rotational rainbow structure in Na2-Ar, high precision mass measurement on single ions using cyclotron resonance, low temperature energy transfer, trapping of neutral atoms, and vibrationally inelastic collisions.

Kleppner, D.; Pritchard, D.E.; Ahmad-Bitar, R.; Ducas, T.; Kelleher, D.; Ligare, M.; Lyyra, A.M.; Moskowitz, P.; Saenger, K.L.; Smith, N.

1984-01-01

144

Luminescence resonance energy transfer  

Microsoft Academic Search

Fluorescence resonance energy transfer (FRET), in which a fluorescent donor molecule transfers energy via a nonradiative dipole-dipole interaction to an acceptor molecule (which is usually a fluorescent molecule), is a standard spectroscopic technique for measuring distances in the 10-70 Angstrom range. We have used a luminescent europium chelate as donor and an organic dye, CY-5, as acceptor. This luminescence resonance

Paul R. Selvin; Tariq M. Rana; John E. Hearst

1994-01-01

145

Resonant dielectric metamaterials  

DOEpatents

A resonant dielectric metamaterial comprises a first and a second set of dielectric scattering particles (e.g., spheres) having different permittivities arranged in a cubic array. The array can be an ordered or randomized array of particles. The resonant dielectric metamaterials are low-loss 3D isotropic materials with negative permittivity and permeability. Such isotropic double negative materials offer polarization and direction independent electromagnetic wave propagation.

Loui, Hung; Carroll, James; Clem, Paul G; Sinclair, Michael B

2014-12-02

146

Optical Feshbach Resonances: Field-Dressed Theory and Experimental Comparisons  

E-print Network

Optical Feshbach resonances (OFRs) have generated significant experimental interest in recent years. These resonances are promising for many-body physics experiments, yet the practical application of OFRs has been limited. The theory of OFRs has been based on an approximate model that fails in important detuning regimes, and the incomplete theoretical understanding of this effect has hindered OFR experiments. We present the most complete theoretical treatment of OFRs to date, demonstrating important characteristics that must be considered in OFR experiments and comparing OFRs to the well studied case of magnetic Feshbach resonances. We also present a comprehensive treatment of the approximate OFR model, including a study of the range of validity for this model. Finally, we derive experimentally useful expressions that can be applied to real experimental data to extract important information about the resonance structure of colliding atoms.

Nicholson, T L; Bloom, B J; Williams, J R; Thomsen, J W; Ye, J; Julienne, P S

2015-01-01

147

Review: Magnetic resonance imaging techniques in ophthalmology  

PubMed Central

Imaging the eye with magnetic resonance imaging (MRI) has proved difficult due to the eye’s propensity to move involuntarily over typical imaging timescales, obscuring the fine structure in the eye due to the resulting motion artifacts. However, advances in MRI technology help to mitigate such drawbacks, enabling the acquisition of high spatiotemporal resolution images with a variety of contrast mechanisms. This review aims to classify the MRI techniques used to date in clinical and preclinical ophthalmologic studies, describing the qualitative and quantitative information that may be extracted and how this may inform on ocular pathophysiology. PMID:23112569

Fagan, Andrew J.

2012-01-01

148

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

149

Quantum Phase Extraction in Isospectral Electronic Nanostructures  

E-print Network

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.

Christopher R. Moon; Laila S. Mattos; Brian K. Foster; Gabriel Zeltzer; Wonhee Ko; Hari C. Manoharan

2008-03-16

150

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.

Lana Hays

2009-01-01

151

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.

Lana Hays

2009-01-01

152

Yeast DNA Extraction  

NSDL National Science Digital Library

This laboratory exercise is designed to show learners how DNA can easily be extracted from yeast 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.

Lana Hays

2009-01-01

153

Mandibular incisor extraction  

Microsoft Academic Search

Cranio-mandibular dysfunction therapy of a moderate Angle Class III malocclusion with retroclined incisors with anterior crossbite and pronounced crowding was based not on extraction of the first premolars but on protrusion of the incisors and the extraction of one lower incisor.

Hans-Jürgen Pauls

1999-01-01

154

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 Microguitars from Cornell University (1997 and 2003) MHz-GHz mechanical resonators Uses: RF signal processing

Bai, Zhaojun

155

Resonant Quadrupole Peter Cameron -BNL  

E-print Network

Resonant Quadrupole Monitor Peter Cameron - BNL #12;LARP Workshop at FNAL6/9/2003 2 Resonant BPM · M. Kesselman et al - PAC 2001 · Stub-tuned 1/4 wave resonator · Simulated in Spice · frequency ~ 240MHz (8.5xRF) · Qloaded ~ 100 optimal coupling · In-tunnel hybrid for and · Resonate difference mode

Large Hadron Collider Program

156

Distribution behavior of astatine: Solvent extraction and back extraction  

Microsoft Academic Search

The distribution behavior of astatine was studied at tracer concentrations and over a wide range of carrier iodide concentration in both solvent extraction and back extraction processes. Astatine compounds were extracted instantly into the organic solvent, CS2 from the carrier free and carrier iodide containing solutions. Back extraction of astatine with various NaOH solutions followed by solvent extraction caused the

M. S. Sultana; A. Toyoshima; N. Takahashi; H. Baba

2001-01-01

157

Quantify Resonance Inspection with Finite Element-Based Modal Analyses  

SciTech Connect

Resonance inspection uses the natural acoustic resonances of a part to identify anomalous parts. Modern instrumentation can measure the many resonant frequencies rapidly and accurately. Sophisticated sorting algorithms trained on sets of good and anomalous parts can rapidly and reliably inspect and sort parts. This paper aims at using finite-element-based modal analysis to put resonance inspection on a more quantitative basis. A production-level automotive steering knuckle is used as the example part for our study. First, the resonance frequency spectra for the knuckle are measured with two different experimental techniques. Next, scanning laser vibrometry is used to determine the mode shape corresponding to each resonance. The material properties including anisotropy are next measured to high accuracy using resonance spectroscopy on cuboids cut from the part. Then, finite element model (FEM) of the knuckle is generated by meshing the actual part geometry obtained with computed tomography (CT). The resonance frequencies and mode shapes are next predicted with a natural frequency extraction analysis after extensive mesh size sensitivity study. The good comparison between the predicted and the experimentally measured resonance spectra indicate that finite-element-based modal analyses have the potential to be a powerful tool in shortening the training process and improving the accuracy of the resonance inspection process for a complex, production level part. The finite element based analysis can also provide a means to computationally test the sensitivity of the frequencies to various possible defects such as porosity or oxide inclusions especially in the high stress regions that the part will experience in service.

Lai, Canhai; Sun, Xin; Dasch, Cameron; Harmon, George; Jones, Martin

2011-06-01

158

Quantify Resonance Inspection with Finite Element-Based Modal Analyses  

SciTech Connect

Resonance inspection uses the natural acoustic resonances of a part to identify anomalous parts. Modern instrumentation can measure the many resonant frequencies rapidly and accurately. Sophisticated sorting algorithms trained on sets of good and anomalous parts can rapidly and reliably inspect and sort parts. This paper aims at using finite-element-based modal analysis to put resonance inspection on a more quantitative basis. A production-level automotive steering knuckle is used as the example part for our study. First, the resonance frequency spectra for the knuckle are measured with two different experimental techniques. Next, scanning laser vibrometry is used to determine the mode shape corresponding to each resonance. The material properties including anisotropy are next measured to high accuracy using resonance spectroscopy on cuboids cut from the part. Then, finite element model (FEM) of the knuckle is generated by meshing the actual part geometry obtained with computed tomography (CT). The resonance frequencies and mode shapes are next predicted with a natural frequency extraction analysis after extensive mesh size sensitivity study. The good comparison between the predicted and the experimentally measured resonance spectra indicate that finite-element-based modal analyses have the potential to be a powerful tool in shortening the training process and improving the accuracy of the resonance inspection process for a complex, production level part. The finite element based analysis can also provide a means to computationally test the sensitivity of the frequencies to various possible defects such as porosity or oxide inclusions especially in the high stress regions that the part will experience in service.

Sun, Xin; Lai, Canhai; Dasch, Cameron

2010-11-10

159

Tunable Resonant Scanners  

NASA Astrophysics Data System (ADS)

The most attractive features of resonant scanners are high reliability and eternal life as well as extremely low wobble and jitter. Power consumption is also low, electronic drive is simple, and the device is capable of handling large beams. All of these features are delivered at a low cost in a small package. The resonant scanner's use in numerous high precision applications, however, has been limited because of the difficulty in controlling its phase and resonant frequency. This paper introduces the concept of tunable/controllable resonant scanners, discusses their features, and offers a number of tuning techniques. It describes two angular scanner designs and presents data on tunable range and life tests. It also reviews applications for these new tunable resonant scanners that preserve the desirable features of earlier models while removing the old problems with synchronization or time base flexibility. The three major types of raster scanning applications where the tunable resonant scanner may be of benefit are: 1. In systems with multiple time bases such as multiple scanner networks or with scanners keyed to a common clock (the line frequency or data source) or a machine with multiple resonant scanners. A typical application is image and text transmission, also a printer with a large data base where a buffer is uneconomical. 2. In systems sharing data processing or laser equipment for reasons of cost or capacity, typically multiple work station manufacturing processes or graphic processes. 3. In systems with extremely precise time bases where the frequency stability of conventional scanners cannot be relied upon.

Montagu, Jean I.

1987-01-01

160

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

SciTech Connect

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 × 10{sup 16}–4.8 × 10{sup 17} m{sup ?3}, respectively.

Yang, Juan; Shi, Feng; Jin, Yizhou; Wang, Yunmin [College of Astronautics, Northwestern Polytechnic University, Xi'an, Shaanxi 710072 (China)] [College of Astronautics, Northwestern Polytechnic University, Xi'an, Shaanxi 710072 (China); Komurasaki, Kimiya [Department of Aeronautics and Astronautics, The University of Tokyo, Hongo 7-3-1, Bunkyo, Tokyo 113-8656 (Japan)] [Department of Aeronautics and Astronautics, The University of Tokyo, Hongo 7-3-1, Bunkyo, Tokyo 113-8656 (Japan)

2013-12-15

161

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

162

Resonant ultrasound spectrometer  

DOEpatents

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

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

1990-01-01

163

MACHINERY RESONANCE AND DRILLING  

SciTech Connect

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

Leishear, R.; Fowley, M.

2010-01-23

164

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.

S�½kora, Stanislav

165

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

166

Double Entropic Stochastic Resonance  

E-print Network

We demonstrate the appearance of a purely entropic stochastic resonance (ESR) occurring in a geometrically confined system, where the irregular boundaries cause entropic barriers. The interplay between a periodic input signal, a constant bias and intrinsic thermal noise leads to a resonant ESR-phenomenon in which feeble signals become amplified. This new phenomenon is characterized by the presence of two peaks in the spectral amplification at corresponding optimal values of the noise strength. The main peak is associated with the manifest stochastic resonance synchronization mechanism involving the inter-well noise-activated dynamics while a second peak relates to a regime of optimal sensitivity for intra-well dynamics. The nature of ESR, occurring when the origin of the barrier is entropic rather than energetic, offers new perspectives for novel investigations and potential applications. ESR by itself presents yet another case where one constructively can harvest noise in driven nonequilibrium systems.

P. S. Burada; G. Schmid; D. Reguera; J. M. Rubi; P. Hänggi

2009-08-24

167

Superdimensional Metamaterial Resonators  

E-print Network

We propose a fundamentally new method for the design of metamaterial arrays, valid for any waves modeled by the Helmholtz equation, including scalar optics and acoustics. The design and analysis of these devices is based on eigenvalue and eigenfunction asymptotics of solutions to Schr\\"odinger wave equations with harmonic and degenerate potentials. These resonators behave superdimensionally, with a higher local density of eigenvalues and greater concentration of waves than expected from the physical dimension, e.g., planar resonators function as 3- or higher-dimensional media, and bulk material as effectively of dimension 4 or higher. Applications include antennas with a high density of resonant frequencies and giant focussing, and are potentially broadband.

Greenleaf, Allan; Kurylev, Yaroslav; Lassas, Matti; Uhlmann, Gunther

2014-01-01

168

Quartz resonator processing system  

DOEpatents

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

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

1983-01-01

169

Medicinal yeast extracts.  

PubMed

Alcoholic extracts of bakers' yeast (Saccharomyces cerevisiae) have been used for over 60 years in over-the-counter medications for the treatment of hemorrhoids, burns, and wounds. Although previous studies suggested that small peptides were responsible for the medical observations, the peptides were never resolved into separate fractions and identified. In the present report, a protein fraction was prepared by RPC18 chromatography of the extract which enhances wound closure in both diabetic and non-diabetic littermates. The peptides are active in nanomolar amounts and are 600 times more active than the initial extract. SDS-PAGE and N-terminal amino acid sequencing identified 4 polypeptides in the extract. Three of the proteins were small molecular weight stress-associated proteins: copper, zinc superoxide-dismutase, ubiquitin, and glucose lipid regulated protein (HSP 12). The fourth protein, acyl-CoA binding protein II, has not been previously associated with stress proteins. PMID:10547066

Schlemm, D J; Crowe, M J; McNeill, R B; Stanley, A E; Keller, S J

1999-09-01

170

The {Delta}(1232) resonance transition form factor  

SciTech Connect

Old and new measurements of inclusive e--p cross sections in the {Delta}(1232) resonance region have been combined, and a global data fit has been made. Using this fit to parameterize the nonresonant background, the transition form factors have been extracted out to a four-momentum transfer, Q{sup 2}, of 9.8 (GeV/c){sup 2}. The results are systematically higher than those from a previous analysis, but agree within errors. A similar analysis has been done with e--d cross sections, and {sigma}{sub n}/{sigma}{sub p} in the {Delta}(1232) resonance region has been extracted out to a Q{sup 2} of 7.9 (GeV/c){sup 2}. {sigma}{sub n}/{sigma}{sub p} for {Delta}(1232) production is consistent with unity, while {sigma}{sub n}/{sigma}{sub p} for the nonresonant background is constant with Q{sup 2} at approximately 0.4.

Staurt, L.M. [California Univ., Davis, CA (United States)]|[Lawrence Livermore National Lab., CA (United States); Bosted, P.E.; Lung, A. [The American Univ., Washington, DC (United States)] [and others

1993-08-01

171

Viscoelastic property mapping with contact resonance force microscopy.  

PubMed

We demonstrate the accurate nanoscale mapping of near-surface loss and storage moduli on a polystyrene-polypropylene blend with contact resonance force microscopy (CR-FM). These viscoelastic properties are extracted from spatially resolved maps of the contact resonance frequency and quality factor of the AFM cantilever. We consider two methods of data acquisition: (i) discrete stepping between mapping points and (ii) continuous scanning. For point mapping and low-speed scanning, the values of the relative loss and storage modulus are in good agreement with the time-temperature superposition of low-frequency dynamic mechanical analysis measurements to the high frequencies probed by CR-FM. PMID:22054300

Killgore, J P; Yablon, D G; Tsou, A H; Gannepalli, A; Yuya, P A; Turner, J A; Proksch, R; Hurley, D C

2011-12-01

172

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

173

Liquid chromatographic extraction medium  

DOEpatents

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

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

1994-01-01

174

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.

Lana Hays

2009-01-01

175

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.

2007-02-02

176

Liquid chromatographic extraction medium  

DOEpatents

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

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

1994-09-13

177

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

178

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

179

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.

Nadia Tsoneva; Horst Lenske

2014-10-09

180

Method for resonant measurement  

DOEpatents

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

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

1996-01-01

181

Hexagonal quartz resonator  

DOEpatents

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

Peters, R.D.M.

1982-11-02

182

Method for resonant measurement  

DOEpatents

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

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

1996-03-05

183

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

184

Inexpensive Resonance Analysis  

NASA Astrophysics Data System (ADS)

A Barton's Pendulums device is a great tool for teaching students about resonance. Such a setup typically has several pendulums attached to a single string or solid support, where each pendulum is excited at a single frequency. The excitation can be produced by a large pendulum mass or by a motor. If a pendulum has a natural frequency that closely matches the excitation frequency, it swings with a large amplitude; otherwise, it does not. While these visual demonstrations are helpful, resonance behavior can be even better understood by graphically displaying the responses of oscillators to different excitations.

Moran, Timothy J.; Hill, Bradford K.

2009-12-01

185

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

PubMed

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

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

2012-12-01

186

Magnetic Resonance Imaging and Magnetic Resonance Spectroscopy in Dementias  

PubMed Central

This article reviews recent studies of magnetic resonance imaging and magnetic resonance spectroscopy in dementia, including Alzheimer's disease, frontotemporal dementia, dementia with Lewy bodies, idiopathic Parkinson's disease, Huntington's disease, and vascular dementia. Magnetic resonance imaging and magnetic resonance spectroscopy can detect structural alteration and biochemical abnormalities in the brain of demented subjects and may help in the differential diagnosis and early detection of affected individuals, monitoring disease progression, and evaluation of therapeutic effect. PMID:11563438

Hsu, Yuan-Yu; Du, An-Tao; Schuff, Norbert; Weiner, Michael W.

2007-01-01

187

Resonant tank and transformer design in series resonant converter  

Microsoft Academic Search

The objective of this paper is to establish the industrial design procedure of the resonant tank components and HF transformer in series-resonant converter or inverter. Based on the analysis of the main operation principles of the resonant tank and HF transformer, an industrial design process of these components is given by considering the design requirements which is acquired via the

Jin Xiaoyi; Wu Weiyang; Sun Xiaofeng; Liu Jun

2005-01-01

188

Meson and Baryon resonances  

E-print Network

In this talk I review recent advances on the structure of the meson and baryon resonances which can be dynamically generated from the interaction of mesons or mesons and baryons. Particular emphasis is put on results involving vector mesons, which bring new light into the nature of some of the observed higher mass mesons and baryons and make predictions for new states.

E. Oset; L. S. Geng; D. Gamermann; R. Molina; D. Nicmorus. Yamagata-Sekihara; H. Nagahiro; S. Hirenzaki; D. Jido; M. Döring; A. Ramos

2009-01-14

189

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

190

Screening Resonances In Plasmas  

SciTech Connect

When it was suggested that a new recombination mechanism (Resonant Radiative Recombination (RRR)) which, based on very general physical arguments, should happen in dense plasmas and promises to provide useful information for the local temperature and density diagnostics of plasmas, they assumed the existence of screening resonances. For model potentials the existence of screening resonances has been demonstrated beyond reasonable doubt in a number of calculations. The key question, how well those potentials describe the dominant effects of a real plasma remains open. The relation of theoretical predictions to experimentally measurable effects is an important issue at the present stage of their research. In particular, RRR is expected to account for enhanced recombination rates of low energetic electrons with their ions, since the first stage is the resonant capture of a slow electron by an atom or ion. The mechanism that traps an electron is a combination of complicated many-body interactions of the ions and electrons. For clarity they start here, however, with a discussion in terms of local potential traps the shapes of which are determined predominantly and in an average way by two factors: the degree of screening present at the ionic site and the degree of short-range order in the immediate neighborhood of this ion.

Winkler, P.

1998-12-01

191

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

192

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

193

Magnetic resonance imaging  

SciTech Connect

The authors present a review of magnetic resonance imaging. Many topics are explored from instrumentation, spectroscopy, blood flow and sodium imaging to detailed clinical applications such as the differential diagnosis of multiple sclerosis or adrenal adenoma. The emphasis throughout is on descriptions of normal multiplanar anatomy and pathology as displayed by MRI.

Stark, D.D.; Bradley, W.G. Jr.

1988-01-01

194

Magnetic Resonance Spectroscopy (MRS)  

E-print Network

does not require any ionizing radiation. It provides a wealth of information (in vivo) on variousMagnetic Resonance Spectroscopy (MRS) and Its Application in Alzheimer's Disease PRAVAT K. MANDAL1 alterations and the pathophysiology of disease. This article provides a comprehensive description of the MRS

Mandal, Pravat K.

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

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,

197

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

198

Resonant scanning mechanism  

NASA Astrophysics Data System (ADS)

Ball Aerospace & Technologies Corp. developed a Resonant Scanning Mechanism (RSM) capable of combining a 250- Hz resonant scan about one axis with a two-hertz triangular scan about the orthogonal axis. The RSM enables a rapid, high-density scan over a significant field of regard (FOR) while minimizing size, weight, and power requirements. The azimuth scan axis is bearing mounted allowing for 30° of mechanical travel, while the resonant elevation axis is flexure and spring mounted with five degrees of mechanical travel. Pointing-knowledge error during quiescent static pointing at room temperature across the full range is better than 100 ?rad RMS per axis. The compact design of the RSM, roughly the size of a soda can, makes it an ideal mechanism for use on low-altitude aircraft and unmanned aerial vehicles. Unique aspects of the opto-mechanical design include i) resonant springs which allow for a high-frequency scan axis with low power consumption; and ii) an independent lower-frequency scan axis allowing for a wide FOR. The pointing control system operates each axis independently and employs i) a position loop for the azimuth axis; and ii) a unique combination of parallel frequency and amplitude control loops for the elevation axis. All control and pointing algorithms are hosted on a 200-MHz microcontroller with 516 KB of RAM on a compact 3"×4" digital controller, also of Ball design.

Wallace, John; Newman, Mike; Gutierrez, Homero; Hoffman, Charlie; Quakenbush, Tim; Waldeck, Dan; Leone, Christopher; Ostaszewski, Miro

2014-10-01

199

NUCLEAR SPIN RESONANCE  

Microsoft Academic Search

The first experiments on nuclear quadrupole interactions in crystals ; were carried out by R. V. Pound (Phys. Rev., magnetic resonance lines and by H. ; G. Dehmelt and H. Kruger (Naturwiss., 37: 111(1950)) who observed the absorption ; of radiowaves in a neutral magnetic field. The work was subsequently continued ; in two directions: toward the study of large,

V. S. Grechishkin; N. E. Ainbinder

1963-01-01

200

NUCLEAR SPIN RESONANCE  

Microsoft Academic Search

I. Introduction 566 II. NSR energy levels and frequencies 568 1. Energy levels for resonating nuclei with spins 1 or 3\\/2 568 2. NSR energy levels for spin 5\\/2 571 III. Relative intensities of NSR lines 571 1. Relative intensities of Zeeman components in NQR 571 2. Generalized NSR equations 572 3. Relative intensities of NSR lines for spin 1

Vadim S Grechishkin; N. E. Ajnbinder

1964-01-01

201

Seismic Resonant Emission  

Microsoft Academic Search

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

V. A. Korneev

2007-01-01

202

Clinical magnetic resonance imaging  

SciTech Connect

This book presents clinical applications of magnetic resonance imaging with a strong clinical orientation. Covers technique, instrumentation, and contrast agents. Describes MRI of the neck, brain, heart, spine, TMJ and orbit, chest abdomen, pelvis, and the joints. Also includes a high field atlas of the central nervous system.

Brady, T.J.; Edelman, R.R.

1988-01-01

203

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

204

Voltage tunable microwave ferrite resonator  

E-print Network

A novel method of implementing a tunable resonator using an applied voltage is presented. Stress is used to tune a microstrip resonator fabricated on a polycrystalline ferrite substrate. The stress was applied either ...

Oates, Daniel E.

205

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

206

Microwave Resonators Containing Diamond Disks  

NASA Technical Reports Server (NTRS)

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

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

1996-01-01

207

Introduction Magnetic Resonance Imaging (MRI)  

E-print Network

Introduction Statistics Magnetic Resonance Imaging (MRI) Statistics in the UK Statistics at UCL and Beyond #12;Introduction Statistics Magnetic Resonance Imaging (MRI) Statistics in the UK Statistics Magnetic Resonance Imaging (MRI) Statistics in the UK Statistics at UCL Outline Why do Statistics? Some

Wirosoetisno, Djoko

208

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

209

Synchronisation of Resonances with Thresholds  

Microsoft Academic Search

The mechanism by which a resonance may be attracted to a sharp threshold is described with several examples. It involves a threshold cusp interfering constructively with either or both (i) a resonance produced via confinement, (ii) attractive t- and u-channel exchanges. More generally, it is suggested that resonances are eigenstates generated by mixing between confined states and long-range meson and

David V. Bugg

2009-01-01

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, E.M.; Nunnally, W.C.

1985-06-19

211

Encapsulation of olive leaf extract in beta-cyclodextrin.  

PubMed

Olive leaf extract, rich in oleuropein, formed an inclusion complex with beta-cyclodextrin (beta-CD) upon mixing of the components in aqueous media and subsequent freeze-drying. Inclusion complex formation was confirmed by differential scanning calorimetry (DSC). DSC thermograms indicated that the endothermic peaks of both the olive leaf extract and the physical mixture of olive leaf extract with beta-CD, attributed to the melting of crystals of the extract, were absent in DSC thermogram of inclusion complex. Moreover, DSC studies under oxidative conditions indicated that the complex of olive leaf extract with beta-CD was protected against oxidation, since it remained intact at temperatures where the free olive leaf extract was oxidized. Phase solubility studies afforded A L type diagrams, 1:1 complex stoichiometry, a moderate binding constant ( approximately 300 M (-1)), and an increase of the aqueous solubility by approximately 50%. The formation of the inclusion complex was also confirmed by nuclear magnetic resonance (NMR) studies of beta-CD solutions in the presence of both pure oleuropein and olive leaf extract. The NMR data have established the formation of a 1:1 complex with beta-CD that involves deep insertion of the dihydroxyphenethyl moiety inside the cavity from its secondary side. PMID:17764146

Mourtzinos, Ioannis; Salta, Fotini; Yannakopoulou, Konstantina; Chiou, Antonia; Karathanos, Vaios T

2007-10-01

212

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

213

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

214

Measurement of glucose concentration in interstitial fluid by surface plasmon resonance with D-galactose\\/D-glucose binding protein  

Microsoft Academic Search

A novel minimally invasive way to measure blood glucose concentration is proposed by combining interstitial fluid transdermal extraction and surface plasma resonance (SPR) detecting. 55K Hz low-frequency ultrasound pulse is applied for less than 30 seconds to enhance the skin permeability and then interstitial fluid is extracted out of skin by vacuum. The mathematical model to express the correlation between

D. C. Li; J. X. Zhang; P. Wu; F. X. Huang; B. Song; K. X. Xu

2009-01-01

215

Genotoxicity of plant extracts.  

PubMed

Aqueous extracts of seven species used in Brazilian popular medicine (Achyrocline satureoides, Iodina rhombifolia, Desmodium incanum, Baccharis anomala, Tibouchina asperior, Luehea divaricata, Maytenus ilicifolia) were screened to the presence of mutagenic activity in the Ames test (Salmonella/microsome). Positive results were obtained for A. satureoides, B. anomala and L. divaricata with microsomal activation. As shown elsewhere (Vargas et al., 1990) the metabolites of A. satureoides extract also show the capacity to induce prophage and/or SOS response in microscreen phage induction assay and SOS spot chromotest. PMID:1842016

Vargas, V M; Guidobono, R R; Henriques, J A

1991-01-01

216

Supercritical fluid extraction  

DOEpatents

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

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

1994-01-01

217

Damping of metallized bilayer nanomechanical resonators at room temperature  

NASA Astrophysics Data System (ADS)

We investigate the influence of gold thin-films subsequently deposited on a set of initially bare, doubly clamped, high-stress silicon nitride string resonators at room temperature. Analytical expressions for resonance frequency, quality factor and damping for both in- and out-of-plane flexural modes of the bilayer system are presented, which allows for the determination of effective elastic parameters of the composite structure from our experimental data. We find the inverse quality factor to scale linearly with the gold film thickness, indicating that the overall damping is governed by losses in the metal. Correspondingly, the mechanical linewidth increases by more than one order of magnitude compared to the bare silicon nitride string resonator. Furthermore, we extract mechanical quality factors of the gold film for both flexural modes and show that they can be enhanced by complete deposition of the metal in a single step, suggesting that surface and interface losses play a vital role in metal thin-films.

Seitner, Maximilian J.; Gajo, Katrin; Weig, Eva M.

2014-11-01

218

Oversized interference switches of active resonant microwave compressors  

NASA Astrophysics Data System (ADS)

Interference switches of resonant microwave compressors made of single mode waveguides provide high coupling factors after switching and rapid energy extraction. The disadvantage of these switches is low electrical strength which limits output power values. Oversized waveguides maintain higher electrical strength due to large dimensions of a cross section but mode transformation disturbs the regular operation of the switch. Operation of interference switches with a gaseous discharge gap as a switching element in oversized rectangular waveguides was studied experimentally. Conditions of their effective switching in active resonant microwave compressors were derived. It was shown that the stable microwave pulses of gigawatt power level in S-band and pulses of 0.1 GW pulse power in X- band can be produced in resonant microwave compressors with oversized interference switches. Possible switch designs are discussed.

Avgustinovich, V.; Artemenko, S.; Kaminsky, V.; Novikov, S.; Yushkov, Yu; Osipov, V.

2014-11-01

219

Surface-resistance measurements using superconducting stripline resonators  

SciTech Connect

We present a method to measure the absolute surface resistance of conductive samples at a set of GHz frequencies with superconducting lead stripline resonators at temperatures 1–6 K. The stripline structure can easily be applied for bulk samples and allows direct calculation of the surface resistance without the requirement of additional calibration measurements or sample reference points. We further describe a correction method to reduce experimental background on high-Q resonance modes by exploiting TEM-properties of the external cabling. We then show applications of this method to the reference materials gold, tantalum, and tin, which include the anomalous skin effect and conventional superconductivity. Furthermore, we extract the complex optical conductivity for an all-lead stripline resonator to find a coherence peak and the superconducting gap of lead.

Hafner, Daniel; Dressel, Martin; Scheffler, Marc, E-mail: scheffl@pi1.physik.uni-stuttgart.de [1. Physikalisches Institut, Universität Stuttgart, D-70550 Stuttgart (Germany)] [1. Physikalisches Institut, Universität Stuttgart, D-70550 Stuttgart (Germany)

2014-01-15

220

Surface-resistance measurements using superconducting stripline resonators.  

PubMed

We present a method to measure the absolute surface resistance of conductive samples at a set of GHz frequencies with superconducting lead stripline resonators at temperatures 1-6 K. The stripline structure can easily be applied for bulk samples and allows direct calculation of the surface resistance without the requirement of additional calibration measurements or sample reference points. We further describe a correction method to reduce experimental background on high-Q resonance modes by exploiting TEM-properties of the external cabling. We then show applications of this method to the reference materials gold, tantalum, and tin, which include the anomalous skin effect and conventional superconductivity. Furthermore, we extract the complex optical conductivity for an all-lead stripline resonator to find a coherence peak and the superconducting gap of lead. PMID:24517793

Hafner, Daniel; Dressel, Martin; Scheffler, Marc

2014-01-01

221

Feshbach resonances in ultracold gases  

SciTech Connect

Feshbach resonances are the essential tool to control the interaction between atoms in ultracold quantum gases. They have found numerous experimental applications, opening up the way to important breakthroughs. This review broadly covers the phenomenon of Feshbach resonances in ultracold gases and their main applications. This includes the theoretical background and models for the description of Feshbach resonances, the experimental methods to find and characterize the resonances, a discussion of the main properties of resonances in various atomic species and mixed atomic species systems, and an overview of key experiments with atomic Bose-Einstein condensates, degenerate Fermi gases, and ultracold molecules.

Chin Cheng; Grimm, Rudolf; Julienne, Paul; Tiesinga, Eite [Department of Physics and James Franck Institute, University of Chicago, Chicago, Illinois 60637 (United States); Center for Quantum Physics and Institute of Experimental Physics, University of Innsbruck, Technikerstrasse 25, 6020 Innsbruck (Austria) and Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Otto-Hittmair-Platz 1, 6020 Innsbruck (Austria); Joint Quantum Institute, National Institute of Standards and Technology and University of Maryland, 100 Bureau Drive, Gaithersburg, Maryland 20899-8423 (United States)

2010-04-15

222

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

223

Resonant Cascaded Downconversion  

SciTech Connect

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

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

2012-01-01

224

Surface Plasmon Resonance Laboratory  

NSDL National Science Digital Library

This lab focuses on the optical generation and modeling of Surface Plasmons, in particular the attempt of predicting and generating a resonance condition in a three layer system; glass, metal and air. The lab is designed to easily create a film and test itâs resonance with minimal cost and time to prepare the setup between testing. This concept can be demonstrated in a more elaborate setup, but is not necessary unless this demonstration will be used as a research instrument afterwards. This lab is comprised of four main parts: 1. Understanding the theory of SPR, through deriving the Fresnel equations from Maxwell Equations. 2. Determining the optimal conditions for the Prism Coating (Modeling). 3. Fabricating the coated prism with a deposition system. 4. Comparing modeling and experiment, explain error.

Sã¡nchez, Erik

2010-11-24

225

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

226

Photorefractivity in WGM resonators  

NASA Technical Reports Server (NTRS)

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

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

2006-01-01

227

Cross resonant optical antenna.  

PubMed

We propose a novel cross resonant optical antenna consisting of two perpendicular nanosized gold dipole antennas with a common feed gap. We demonstrate that the cross antenna is able to convert propagating fields of any polarization state into correspondingly polarized, localized, and enhanced fields and vice versa. The cross antenna structure therefore opens the road towards the control of light-matter interactions based on polarized light as well as the analysis of polarized fields on the nanometer scale. PMID:19659107

Biagioni, P; Huang, J S; Duò, L; Finazzi, M; Hecht, B

2009-06-26

228

Tandem resonator reflectance modulator  

DOEpatents

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

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

1994-09-06

229

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

230

A nonlinear resonant switch  

Microsoft Academic Search

A resonant switch is introduced that uses linear tank elements. Zero-current switching is obtained even through the peak transistor voltage and current stresses can approach those of an equivalent ideal pulsewidth-modulated converter. Reduced switching loss without a substantial increase in conduction loss is therefore possible. An approximate analysis is outlined, and transistor peak-voltage and current stresses are shown to be

R. W. Erickson; A. F. Hernandez; A. F. Witulski; R. Xu

1989-01-01

231

Cesium Atomic Resonance Filter  

Microsoft Academic Search

An atomic resonance filter (ARF), composed of a cell containing an absorbing gas and two interference\\/absorption filter stacks, is designed to be both wide angle and ultra -narrowband. The bandwidth of this filter, in the range of 1-10mA, is determined by the absorption linewidth of the absorbing gas. Light entering the ARF within this bandwidth excites the gas to a

Brian James Batdorf

1991-01-01

232

Tandem resonator reflectance modulator  

DOEpatents

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

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

1994-01-01

233

Ultraminiature resonator accelerometer  

SciTech Connect

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

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

1996-04-01

234

Resonant non-gaussianity  

NASA Astrophysics Data System (ADS)

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; Pajer, Enrico

2011-01-01

235

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

236

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

237

Undulator induced resonances  

SciTech Connect

Undulators appear to be nearly ideal radiation sources for use in storage rings because of their high brightness and small perturbation on stored beam characteristics. We consider the effects of higher-order magnetic field errors and show how they increase beam size and may lead to unstable growth of betatron oscillations. We have observed such effects in SPEAR at betatron tunes satisfying the equations: 3nu/sub x/ + nu/sub y/ = 21 and nu/sub x/ + 3nu/sub y/ = 21. The widths of these resonances were measured to be GAMMA = 0.008 +- 0.004. They are clearly visible on the synchrotron light monitors with a very dynamic and characteristic beam blow-up pattern (reminiscent of a Miller beer label). A model is developed which predicts the locations of resonances, their widths and the projected shapes observed on the light monitors. By inducing such high-order coupling resonances one could study such things as the beam distribution in electron rings or possibly turbulent motion in proton rings.

Harris, J.; Morton, P.; Spencer, J.; Winick, H.

1983-08-01

238

Extracting Hydrogen Electricity from  

E-print Network

Extracting Hydrogen Electricity from B R U C E E . L O G A N T H E P E N N S Y L V A N I in vehicles. Hydrogen is considered a mobile source of energy, but it must have renewable starting materials Association, a nonprofit organization, 9.2 billion cubic meters (m3) of hydrogen, with an estimated value

239

ENGINEERING BULLETIN: SOLVENT EXTRACTION  

EPA Science Inventory

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

240

Underground mineral extraction  

Microsoft Academic Search

A method for extracting an underground mineral such as coal, which avoids the need for sending personnel underground and which enables the mining of steeply pitched seams of the mineral. The method includes the use of a narrow vehicle which moves underground along the mineral seam and which is connected by pipes or hoses to water pumps at the surface

R. A. Frosch; C. G. Miller; J. B. Stephens

1980-01-01

241

Underground mineral extraction  

Microsoft Academic Search

A method was developed for extracting underground minerals such as coal, which avoids the need for sending personnel underground and which enables the mining of steeply pitched seams of the mineral. The method includes the use of a narrow vehicle which moves underground along the mineral seam and which is connected by pipes or hoses to water pumps at the

C. G. Miller; J. B. Stephens

1980-01-01

242

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...

243

Dipole broadening of resonance lines in spin systems having a nonequidistant spectrum  

Microsoft Academic Search

1. In many problems involving magnetic resonance, it is necessary to extract the secular part H~I from the energy H d of the magnetic dipole-dipole (d-d) interaction between spins; the secular part commutes with the Hamiltonian determining the spin-system energy spectrum. We use H~t, for example, in calculating the moments of resonance absorption lines broadened by d-d interactions [1]. The

G. A. Volgina; M. D. Zviadadze

1975-01-01

244

Comparison of sub-coulomb stripping and analog resonance results in 93Zr  

NASA Astrophysics Data System (ADS)

The 92Zr(d, p) 93Zr reaction, leading to states in 93Zr which are parents of analog states observed in 92Zr(p, p) elastic scattering, has been studied for incident deuteron energies below the Coulomb barrier. For each of the parent states the reduced normalization has been extracted, and these have been compared with the reduced normalizations calculated for the analog resonances on the basis of various analog resonance theories.

Kent, J. J.; Morgan, J. F.; Seyler, R. G.

1972-12-01

245

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

246

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

247

Comparison of the outcomes of the lower incisor extraction, premolar extraction and non-extraction treatments.  

PubMed

The aim of this retrospective study was to evaluate the treatment outcome of lower incisor extraction and to compare it with premolar extraction and non-extraction treatment. The sample consisted of 60 subjects with Class I malocclusion and moderate crowding. The sample was separated into three groups: extraction of a lower incisor group, extraction of a four first premolar group and a non-extraction group. All groups involved 13 girls and 7 boys with a total of 20 patients. The Peer assessment rating (PAR) index was applied to a patient's pre-treatment (T1) and post-treatment (T2) dental casts. T1 dental casts were also used for determining Bolton discrepancy. One-way analysis of variance and post hoc Tukey HSD tests were used for statistical analysis. For the mean percentage PAR score reduction for each group, there was one significant difference seen between the lower incisor extraction group and the non-extraction group (P = 0.047). For the mean anterior ratios, there were significant differences among premolar extraction group versus non-extraction group (P = 0.042) and non-extraction group versus lower incisor extraction group (P = 0.000). For the mean overall ratios, there were significant differences among the premolar extraction group versus lower incisor extraction group (P = 0.048) and the non-extraction group versus lower incisor extraction group (P = 0.001). Orthodontic treatment without extraction has a better treatment outcome than the four-first premolar extraction and single lower incisor extraction protocols in Class I cases with moderate to severe mandibular anterior crowding. PMID:21745824

Ileri, Zehra; Basciftci, Faruk Ayhan; Malkoc, Siddik; Ramoglu, Sabri Ilhan

2012-12-01

248

Frequency-resonance-enhanced vibrational resonance in bistable systems.  

PubMed

The dynamics in an overdamped bistable system subject to the action of two periodic forces (assuming their frequencies are ? and ?, and amplitudes are A and B, respectively) is studied. For the usual vibrational resonance, the nonmonotonic dependence of signal output of the low frequency ? on the change of B for a fixed ?, the condition ??? is always assumed in all previous studies. Here, removing this restriction, we find that a resonant behavior can extensively occur with respect to the changes of both the frequency ? and amplitude B. Especially, the resonance becomes stronger when ? is chosen such that it is exactly in frequency resonance with ?. This combinative behavior, called frequency-resonance-enhanced vibrational resonance, is of great interest and may shed an improved light on our understanding of the dynamics of nonlinear systems subject to a biharmonic force. PMID:21797317

Yao, Chenggui; Liu, Yan; Zhan, Meng

2011-06-01

249

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

250

Multiresolutional graph cuts for brain extraction from MR images  

NASA Astrophysics Data System (ADS)

This paper presents a multiresolutional brain extraction framework which utilizes graph cuts technique to classify head magnetic resonance (MR) images into brain and non-brain regions. Starting with an over-extracted brain region, we refine the segmentation result by trimming non-brain regions in a coarse-to-fine manner. The extracted brain at the coarser level will be propagated to the finer level to estimate foreground/background seeds as constraints. The short-cut problem of graph cuts is reduced by the proposed pre-determined foreground from the coarser level. In order to consider the impact of the intensity inhomogeneities, we estimate the intensity distribution locally by partitioning volume images of each resolution into different numbers of smaller cubes. The graph cuts method is individually applied for each cube. Compared with four existing methods, the proposed method performs well in terms of sensitivity and specificity in our experiments for performance evaluation.

Chen, Yong-Sheng; Chen, Li-Fen; Wang, Yi-Ting

2013-07-01

251

Resonance Analysis in the Region of Unresolved Resonances  

NASA Astrophysics Data System (ADS)

The independent analysis of new experimental data for 232Th cross sections in the unresolved region performed on the basis of the existing scheme and method of evaluation confirm the previously obtained average resonance parameters. The method of statistical modeling of the resonant cross-section structure in the unresolved resonance region, proposed and developed earlier by introducing the characteristic function of R-matrix elements distribution and the presentation of this by a ladder of fixed "resonances," is used for calculation of the self-shielding factors of 232Th. The results are given in comparison with those of the code NJOY and experimental data.

Lukyanov, A. A.; Koyumdjieva, N. T.; Janeva, N. B.; Volev, K. N.; Schillebeeckx, P.

2005-05-01

252

Pressure dependent resonant frequency of micromechanical drumhead resonators  

SciTech Connect

We examine the relationship between squeeze film effects and resonance frequency in drum-type resonators. We find that the resonance frequency increases linearly with pressure as a result of the additional restoring force contribution from compression of gas within the drum cavity. We demonstrate trapping of the gas by squeeze film effects and geometry. The pressure sensitivity is shown to scale inversely with cavity height and sound radiation is found to be the predominant loss mechanism near and above atmospheric pressure. Drum resonators exhibit linearity and sensitivity suitable to barometry from below 10 Torr up to several atmospheres.

Southworth, D. R.; Craighead, H. G.; Parpia, J. M. [Center for Materials Research, Cornell University, Ithaca, New York 14853 (United States)

2009-05-25

253

Analysis of human muscle extracts by proton NMR  

SciTech Connect

Perchloric acid extracts were prepared from pooled human muscle biopsies from patients diagnosed with scoliosis (SCOL) and cerebral palsy (CP). After neutralization with KOH and removal of perchlorate, the extracts were concentrated by freeze drying and dissolved in /sup 2/H/sub 2/O to contain 120 O.D. units at 280 nm per 0.5 ml. /sup 1/H NMR spectroscopy was performed with the 5 mm probe of a Varian XL300 instrument. Creatine, lactate, carnosine, and choline were the major resonances in the one-dimensional spectra of both extracts. With creatine as reference, 2.5-fold more lactate was found in SCOL than in CP, and a much smaller difference was also found in their carnosine content. Two-dimensional COSY comparison revealed several differences between the two extracts. Taurine, N-acetyl glutamate, glycerophosphoryl choline (or phosphoryl choline) and an unidentified spot were present only in the extract from SCOL but not in that from CP. On the other hand, aspartate, hydroxy-proline, carnitine and glycerophosphoryl ethanolamine were only present in CP but absent in SCOL. Alanine, cysteine, lysine and arginine appeared in both extracts without an apparent intensity difference.

Venkatasubramanian, P.N.; Barany, M.; Arus, C.

1986-03-01

254

LIPID EXTRACTION FROM WHEAT FLOUR USING SUPERCRITICAL FLUID EXTRACTION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Environmental concerns, the disposal cost of hazardous waste, and the time required for extraction encouraged us to look for a method to extract lipids from wheat flour that would be faster, less costly, and more environmentally acceptable. Supercritical Fluid Extraction (SFE) with carbon dioxide (...

255

Resonance strength in Ne22(p,?)Na23 from depth profiling in aluminum  

NASA Astrophysics Data System (ADS)

A novel method for extracting absolute resonance strengths has been investigated. By implanting Ne22 ions into a thick aluminum backing and simultaneously measuring the Ne22+p and Al27+p reactions, the strength of the Erlab=479 keV resonance in Ne22(p,?)Na23 was determined to be ??=0.524(51) eV. This result has significantly reduced uncertainties compared to earlier work. Our results are important for the absolute normalizations of resonance strengths in the Ne22(p,?)Na23 hydrogen-burning reaction and in the Ne22+?s-process neutron-source reactions.

Longland, R.; Iliadis, C.; Cesaratto, J. M.; Champagne, A. E.; Daigle, S.; Newton, J. R.; Fitzgerald, R.

2010-05-01

256

Proton Spin Structure in the Resonance Region  

SciTech Connect

The RSS collaboration has measured the spin structure functions g{sub 1} and g{sub 2} of the proton at Jefferson Lab using the lab's polarized electron beam, the Hall C HMS spectrometer and the UVa polarized solid target. The asymmetries A{sub parallel} and A{sub perp} were measured at the elastic peak and in the region of the nucleon resonances (1.085 GeV < W < 1.910 GeV) at an average four momentum transfer of Q{sup 2} = 1.3 GeV{sup 2}. The extracted spin structure functions and their kinematic dependence make a significant contribution in the study of higher-twist effects and polarized duality tests.

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

2006-10-11

257

A Coupled Global Registration and Segmentation Framework With Application to Magnetic Resonance Prostate Imagery  

Microsoft Academic Search

Extracting the prostate from magnetic resonance (MR) imagery is a challenging and important task for medical image analysis and surgical planning. We present in this work a unified shape-based framework to extract the prostate from MR prostate imagery. In many cases, shape-based segmentation is a two-part problem. First, one must properly align a set of training shapes such that any

Yi Gao; Romeil Sandhu; Gabor Fichtinger; Allen Robert Tannenbaum

2010-01-01

258

Effects of hot water extraction and fungal decay on wood crystalline cellulose structure  

Microsoft Academic Search

The effect of hot-water extraction and two types of fungal decay, brown rot and white rot, on wood crystalline cellulose structure\\u000a was examined using a combination of X-ray diffraction (XRD) and 13C solid-state nuclear magnetic resonance (NMR) spectroscopy. Although having opposite effects on the overall crystallinity\\u000a of the wood, the XRD results revealed that both extraction and brown-rot decay caused

Caitlin HowellAnne; Anne Christine Steenkjær Hastrup; Rory Jara; Flemming Hofmann Larsen; Barry Goodell; Jody Jellison

259

Extractable work from correlations  

E-print Network

Work and quantum correlations are two fundamental resources in thermodynamics and quantum information theory. In this work we study how to use correlations among quantum systems to optimally store work. We analyse this question for isolated quantum ensembles, where the work can be naturally divided into two contributions: a local contribution from each system, and a global contribution originating from correlations among systems. We focus on the latter and consider quantum systems which are locally thermal, thus from which any extractable work can only come from correlations. We compute the maximum extractable work for general entangled states, separable states, and states with fixed entropy. Our results show that while entanglement gives an advantage for small quantum ensembles, this gain vanishes for a large number of systems.

Martí Perarnau-Llobet; Karen V. Hovhannisyan; Marcus Huber; Paul Skrzypczyk; Nicolas Brunner; Antonio Acín

2014-07-29

260

Extracting Decision Correlation Rules  

NASA Astrophysics Data System (ADS)

In this paper, two concepts are introduced: decision correlation rules and contingency vectors. The first concept results from a cross fertilization between correlation and decision rules. It enables relevant links to be highlighted between sets of patterns of a binary relation and the values of target items belonging to the same relation on the twofold basis of the Chi-Squared measure and of the support of the extracted patterns. Due to the very nature of the problem, levelwise algorithms only allow extraction of results with long execution times and huge memory occupation. To offset these two problems, we propose an algorithm based both on the lectic order and contingency vectors, an alternate representation of contingency tables.

Casali, Alain; Ernst, Christian

261

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

262

[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

263

Solvent extraction of molybdenum  

SciTech Connect

The equilibrium and the kinetics of the reaction of Mo(VI) with 8-hydroxyquinoline; 8-hydroxyquinaldine; KELEX 100; LIX63; and LIX65N were studied by solvent extraction. From the equilibrium studies it was concluded that in weakly acidic solution (pH 5 to 6) the complexation reaction requires four protons to convert molybdate into molybdenyl. The extractions constants for LIX63 and 8-hydroxyquinaldine, corrected for the side reaction of the ligand and metal, are 10/sup 16.43/ and 10/sup 14.40/, respectively. In the case of LIX65N, the plot of log(D) vs pH has a maximum at pH 1.0, which was explained qualitatively in terms of protonation of the ligand and molybdic acid at low pH. The extraction constant for the reaction of molybdic acid and the neutral ligand was estimated to be 100,000. The kinetics of extraction Mo (VI) with LIX63, 8-hydroxyquinoline, 8-hydroxyquinaldine, and Kelex 100 were studied in this work. In all cases, except 8-hydroxyquinoline, the rate-determining step of the reaction involves the formation of a 1:1 complex between the neutral ligand and several Mo(VI) species differing in the degree of protonation. The rate-determining step for the reaction of Mo(VI) with 8-hydroxyquinoline involves the formation of a 1:2 complex. The rate constant for the reaction of HMoO/sub 4/ with 8-hydroxyquinaldine is four orders of magnitude smaller than the corresponding value reported in the literature for 8-hydroxyquinoline. The slower reaction with 8-hydroxyquinaldine was attributed to the presence of the methyl group next to the nitrogen atom of the ligand which hinders its binding with molybdenum in the rate determining step of the reaction.

Trujillo, R.A.

1987-01-01

264

Ion extraction system optimization  

SciTech Connect

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

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

2013-07-18

265

Prospex: Protocol Specification Extraction  

Microsoft Academic Search

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

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

2009-01-01

266

Ellipsometric surface plasmon resonance  

NASA Astrophysics Data System (ADS)

We develop a new multifunctional optical biochip system that integrates an ellipsometer with a surface plasmon resonance (SPR) feature. This newly developed biochip biosensor, which we call ESPR for an ellipsometric SPR, provides us with a system to retrieve detailed information such as the optical properties of immobilized biomolecular monolayers, surface concentration variations of biomedical reactions, and kinetic affinity between biomolecules required for further biotech analysis. Our ESPR can also serve as both a research and development tool and a manufacturing tool for various biomedical applications.

Hsu, Wei-Liang; Lee, Shu-Sheng; Lee, Chih-Kung

2009-03-01

267

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

268

Diversity-induced resonance.  

PubMed

We present conclusive evidence showing that different sources of diversity, such as those represented by quenched disorder or noise, can induce a resonant collective behavior in an ensemble of coupled bistable or excitable systems. Our analytical and numerical results show that when such systems are subjected to an external subthreshold signal, their response is optimized for an intermediate value of the diversity. These findings show that intrinsic diversity might have a constructive role and suggest that natural systems might profit from their diversity in order to optimize the response to an external stimulus. PMID:17155633

Tessone, Claudio J; Mirasso, Claudio R; Toral, Raúl; Gunton, James D

2006-11-10

269

Nanotube resonator devices  

DOEpatents

A fully-functional radio receiver fabricated from a single nanotube is being disclosed. Simultaneously, a single nanotube can perform the functions of all major components of a radio: antenna, tunable band-pass filter, amplifier, and demodulator. A DC voltage source, as supplied by a battery, can power the radio. Using carrier waves in the commercially relevant 40-400 MHz range and both frequency and amplitude modulation techniques, successful music and voice reception has been demonstrated. Also disclosed are a radio transmitter and a mass sensor using a nanotube resonator device.

Jensen, Kenneth J; Zettl, Alexander K; Weldon, Jeffrey A

2014-05-06

270

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

271

Feature extraction of multispectral data  

NASA Technical Reports Server (NTRS)

A method is presented for feature extraction of multispectral scanner data. Non-training data is used to demonstrate the reduction in processing time that can be obtained by using feature extraction rather than feature selection.

Crane, R. B.; Crimmins, T.; Reyer, J. F.

1973-01-01

272

GAMMA DENSITY CONTROLS EXTRACTION COLUMN  

Microsoft Academic Search

Gamma absorption density gauging can monitor both the organic extract ; and the aqueous raffinate and can control column feed rates to maintain normal ; steadystate operation in a liquid-liquid uranium extraction process. (auth);

Ryle

1957-01-01

273

Hadron resonance probes of QGP  

E-print Network

We discuss the indirect and direct role of the short-lived resonances as probes of QGP freeze-out process. The indirect effect is the distortion of stable single particle yields and spectra by contributions of decaying resonances, which alter significantly the parameters obtained in fits to experimental data. We than discuss the direct observation of short-lived resonances as a probe of post-hadronization dynamics allowing to distinguish between different hadronization models.

Giorgio Torrieri; Johann Rafelski

2004-10-25

274

Resonance capture at arbitrary inclination  

NASA Astrophysics Data System (ADS)

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° with 5° increments totalling nearly 6 × 105 numerical simulations. 30 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 [10°,110°]. Orbit inversion is possible for initially circular orbits with inclinations in the range [60°,130°]. Capture in the 1:1 co-orbital resonance occurs with great likelihood at large retrograde inclinations. The planet's orbital eccentricity, if larger than 0.1, reduces the capture probabilities through the action of the eccentric Kozai-Lidov mechanism. A capture asymmetry appears between inner and outer resonances as prograde orbits are preferentially trapped in inner resonances. The relative capture efficiency of retrograde resonance suggests that the dynamical lifetimes of Damocloids and Centaurs on retrograde orbits must be significantly larger than those on prograde orbits implying that the recently identified asteroids in retrograde resonance, 2006 BZ8, 2008 SO218, 2009 QY6 and 1999 LE31 may be among the oldest small bodies that wander between the outer giant planets.

Namouni, F.; Morais, M. H. M.

2015-01-01

275

Synchonisation of Resonances with Thresholds  

E-print Network

The mechanism by which a resonance may be attracted to a sharp threshold is described with several examples. It involves a threshold cusp interfering constructively with either or both (i) a resonance produced via confinement, (ii) attractive t- and u-channel exchanges. More generally, it is suggested that resonances are eigenstates generated by mixing between confined states and long-range meson and baryon exchanges.

D. V. Bugg

2008-07-05

276

UHF SAW resonators and applications  

Microsoft Academic Search

Surface acoustic wave resonators suitable for systems applications have been produced at frequencies as high as 1.43 GHz. These resonators are two-port single-pole devices with distortionless response characteristics and an unloaded Q value of 10,400\\/F(GHz) or more; they can be used to stabilize UHF oscillators or as narrowband filters. The resonators are characterized by low matched insertion loss (approximately 3

W. J. Tanski

1980-01-01

277

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

278

Control of the slow extraction process in a dedicated proton synchrotron for hadron therapy  

E-print Network

The ring design of the synchrotron for cancer treatment, based on the third-order resonant extraction, was been performed to meet the special medical requirements. The uniformity of the slow extracted beam from the proton synchrotron is the main requirement on the beam quality determined by the medical application. The smooth extraction during at least 400 msec should be realized for the `raster' scanning of tumours. Control of the slow extraction over the whole spill time is discussed in this report. To keep all lattice functions of the ring constant during the extraction a slow movement of the accelerated particles into the resonance can be used. To reduce degradation of the uniformity of the extracted beam by ripples from the power converters of the magnetic elements, the RF empty-bucket channeling method should be utilized. This method allows reduce the ripple influence during slow extraction. Both methods are analyzed to control the slow extraction for the dedicated proton synchrotron. The main parameter...

Molodozhentsev, A Yu

1999-01-01

279

Polarographic determination of extraction constants.  

PubMed

The extraction constant of three organic compounds containing nitrogen as a picrate ion pair in a water-chloroform system were determined by following polarographically the picrate concentration in the aqueous phase as a function of the added amount of reagent. The extraction constants were also determined spectrophotometrically (via batch extraction). The obtained results are in good agreement. The proposed method is applicable for extraction constants with values between 10(3) and 10(9). PMID:3658646

Dingjan, H A; Van Bennekom, W P; Bult, A

1987-08-21

280

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

281

Compact biaxial micromachined resonant accelerometer  

NASA Astrophysics Data System (ADS)

This paper presents a biaxial silicon resonant microaccelerometer characterized by a high sensitivity and a low cross-axis sensitivity. The device has a detection structure with a single inertial mass and two pairs of resonating beams allowing for the simultaneous differential measurement of acceleration acting along two different axes. The design of the accelerometer and in particular the geometrical configuration of the resonating elements is analytically optimized and finalized through finite element simulations. Experimental results on a fabricated device demonstrate a mean differential sensitivity of 250 Hz?g-1 at a polarization voltage of 4 V, around a resonance frequency of 84 kHz.

Caspani, Alessandro; Comi, Claudia; Corigliano, Alberto; Langfelder, Giacomo; Tocchio, Alessandro

2013-10-01

282

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

283

Electromagnetic production of hyperon resonances  

SciTech Connect

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

K. Hicks, D. Keller, W. Tang

2011-10-01

284

Electromagnetic production of hyperon resonances  

SciTech Connect

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

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

2011-10-24

285

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

286

Fano resonances in nanoscale structures  

SciTech Connect

Modern nanotechnology allows one to scale down various important devices (sensors, chips, fibers, etc.) and thus opens up new horizons for their applications. The efficiency of most of them is based on fundamental physical phenomena, such as transport of wave excitations and resonances. Short propagation distances make phase-coherent processes of waves important. Often the scattering of waves involves propagation along different paths and, as a consequence, results in interference phenomena, where constructive interference corresponds to resonant enhancement and destructive interference to resonant suppression of the transmission. Recently, a variety of experimental and theoretical work has revealed such patterns in different physical settings. The purpose of this review is to relate resonant scattering to Fano resonances, known from atomic physics. One of the main features of the Fano resonance is its asymmetric line profile. The asymmetry originates from a close coexistence of resonant transmission and resonant reflection and can be reduced to the interaction of a discrete (localized) state with a continuum of propagation modes. The basic concepts of Fano resonances are introduced, their geometrical and/or dynamical origin are explained, and theoretical and experimental studies of light propagation in photonic devices, charge transport through quantum dots, plasmon scattering in Josephson-junction networks, and matter-wave scattering in ultracold atom systems, among others are reviewed.

Miroshnichenko, Andrey E.; Flach, Sergej; Kivshar, Yuri S. [Nonlinear Physics Centre and Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Research School of Physics and Engineering, Australian National University, Canberra, Australian Capital Territory 0200 (Australia); Max-Planck-Institut fuer Physik Komplexer Systeme, Noethnitzer Strasse 38, D-01187 Dresden (Germany); Nonlinear Physics Centre and Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Research School of Physics and Engineering, Australian National University, Canberra, Australian Capital Territory 0200 (Australia)

2010-07-15

287

Innovative Drying and Nutrients Extraction  

E-print Network

to the extraction process. This method evaporates the water from the products but also drives off up to 70 percent methods. Project Description This project will evaluate whether the new drying and nutrients extraction process. . Prototype innovative drying and nutrients extraction system Photo credit: Grimmway Enterprises

288

Exploring DNA Extraction Erica Butts  

E-print Network

(By adding a protease) DNA Binding (DNA Binds to magnetic or silica beads and is washed) Precipitation;Applied Genetics Definition of Relative Extraction Efficiency · Recovery compared to another method to precipitate DNA · Rehydrated with 100 µL TE #12;Applied Genetics Blood Extracted DNA Cells Extraction

Perkins, Richard A.

289

Challenges in Managing Information Extraction  

ERIC Educational Resources Information Center

This dissertation studies information extraction (IE), the problem of extracting structured information from unstructured data. Example IE tasks include extracting person names from news articles, product information from e-commerce Web pages, street addresses from emails, and names of emerging music bands from blogs. IE is all increasingly…

Shen, Warren H.

2009-01-01

290

Resonance neutron capture studies.  

NASA Astrophysics Data System (ADS)

Neutron capture studies taking place at the newly refurbished GELINA pulsed neutron facility are presented. These investigations are of two types: first, the total neutron capture cross section is measured with high resolution in the keV region for isotopes which are particularly interesting for the study of s-process nucleosynthesis. From the obtained resonance parameters and/or capture areas, one can derive the stellar capture rate as a function of the temperature kT. Results have recently been obtained for the bottlenecks 138Ba and 208Pb, and for the s-only isotope 136Ba. A second type of experiment consists of measuring with Ge-detectors primary and secondary gamma-rays from neutron capture in single resonances in an effort to derive their spins and parities. These values are important for the interpretation of the results of parity-non-conservation measurements performed at LANSCE (LANL) by the TRIPLE collaboration. Results have just been obtained for the isotope 109Ag.

Corvi, F.; Athanassopulos, K.; Beer, H.; Mutti, P.; Postma, H.; Zanini, L.

291

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

292

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

293

Nuclear Magnetic Resonance Gyroscope  

NASA Astrophysics Data System (ADS)

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

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

2012-06-01

294

Luminescence resonance energy transfer  

SciTech Connect

Fluorescence resonance energy transfer (FRET), in which a fluorescent donor molecule transfers energy via a nonradiative dipole-dipole interaction to an acceptor molecule (which is usually a fluorescent molecule), is a standard spectroscopic technique for measuring distances in the 10-70 Angstrom range. We have used a luminescent europium chelate as donor and an organic dye, CY-5, as acceptor. This luminescence resonance energy transfer (LRET) has several advantages over the more conventional FRET. The distance at which 50% of the energy is transferred (R[sub 0]) is large, 70 [angstrom]; the donor lifetime is single exponential and long (0.63 ms in H[sub 2]O; 2.5 ms in D[sub 2]O), making lifetime measurements facile and highly accurate; the orientation dependence (k[sup 2]) of energy transfer is minimized by the donor's multiple electronic transitions and long lifetime, limiting uncertainty in the measured distance due to orientation effects to [+-]12% in the worst case; the sensitized emission of the acceptor can be measured with little or no interfering background, yielding a >50-fold improvement in signal to background over standard donor-acceptor pairs and enabling distances several times R[sub 0] to be measured. 13 refs., 4 figs.

Selvin, P.R.; Rana, T.M.; Hearst, J.E. (Univ. of California, Berkeley, CA (United States) Lawrence Berkeley Lab., CA (United States))

1994-06-29

295

TE10 resonant iris with angular alignment  

E-print Network

TE10 resonant iris with angular alignment TE101 mode cavities TM110 mode cavities TE01 (TE10) resonant iris 1a 1b Fig. 1: Filter configurations utilizing cavity and iris resonances. Resonant irises and resonant irises. Two different configurations, which allow precise control of the direct couplings between

Bornemann, Jens

296

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

297

MRI feature extraction using a linear transformation  

NASA Astrophysics Data System (ADS)

We present development and application of a feature extraction method for magnetic resonance imaging (MRI), without explicit calculation of tissue parameters. We generate a three-dimensional (3-D) feature space representation of the data, in which normal tissues are clustered around pre-specified target positions and abnormalities are clustered somewhere else. This is accomplished by a linear minimum mean square error transformation of categorical data to target positions. From the 3-D histogram (cluster plot) of the transformed data, we identify clusters and define regions of interest (ROIs) for normal and abnormal tissues. There ROIs are used to estimate signature (feature) vectors for each tissue type which in turn are used to segment the MRI scene. The proposed feature space is compared to those generated by tissue-parameter-weighted images, principal component images, and angle images, demonstrating its superiority for feature extraction. The method and its performance are illustrated using a computer simulation and MRI images of an egg phantom and a human brain.

Soltanian-Zadeh, Hamid; Windham, Joe P.; Peck, Donald J.

1993-09-01

298

Fission product solvent extraction  

SciTech Connect

Two main objectives concerning removal of fission products from high-level tank wastes will be accomplished in this project. The first objective entails the development of an acid-side Cs solvent-extraction (SX) process applicable to remediation of the sodium-bearing waste (SBW) and dissolved calcine waste (DCW) at INEEL. The second objective is to develop alkaline-side SX processes for the combined removal of Tc, Cs, and possibly Sr and for individual separation of Tc (alone or together with Sr) and Cs. These alkaline-side processes apply to tank wastes stored at Hanford, Savannah River, and Oak Ridge. This work exploits the useful properties of crown ethers and calixarenes and has shown that such compounds may be economically adapted to practical processing conditions. Potential benefits for both acid- and alkaline-side processing include order-of-magnitude concentration factors, high rejection of bulk sodium and potassium salts, and stripping with dilute (typically 10 mM) nitric acid. These benefits minimize the subsequent burden on the very expensive vitrification and storage of the high-activity waste. In the case of the SRTALK process for Tc extraction as pertechnetate anion from alkaline waste, such benefits have now been proven at the scale of a 12-stage flowsheet tested in 2-cm centrifugal contactors with a Hanford supernatant waste simulant. SRTALK employs a crown ether in a TBP-modified aliphatic kerosene diluent, is economically competitive with other applicable separation processes being considered, and has been successfully tested in batch extraction of actual Hanford double-shell slurry feed (DSSF).

Moyer, B.A.; Bonnesen, P.V.; Sachleben, R.A. [and others

1998-02-01

299

Extracting tag hierarchies.  

PubMed

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

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

2013-01-01

300

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

301

Electromechanical Resonators from Graphene Sheets  

Microsoft Academic Search

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

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

2007-01-01

302

Acceleration-resistant crystal resonator  

NASA Astrophysics Data System (ADS)

A crystal resonator features two crystals mounted such that the acceleration sensitivity vector of one crystal is in an antiparallel relationship to the acceleration sensitivity vector of the other crystal. The composite resonator eliminates acceleration-induced frequency shifts for acceleration in all directions.

Filler, R. L.

1983-10-01

303

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

304

Whispering Gallery Mode Optomechanical Resonator  

NASA Technical Reports Server (NTRS)

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

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

2012-01-01

305

Strange attractor in resonant tunneling  

Microsoft Academic Search

We consider the process of resonant electron tunneling through a double-barrier potential, taking into account nonlinear dynamical effects generated by charge accumulation in the interbarrier space. We use the perturbation approach of Davydov and Ermakov, which was developed for investigating intrinsic bistability in resonant tunneling. For incoming electron flow, which is modulated slowly in time, we show that the resulting

Kirill N. Alekseev; Gennady P. Berman; David K. Campbell

1998-01-01

306

Virtual magnetic resonance colonography  

PubMed Central

Colorectal cancer screening has vast potential. Beyond considerations for cost and diagnostic accuracy, the effectiveness of any colorectal screening strategy will be dependent on the degree of patient acceptance. Magnetic resonance (MR) colonography has been shown to be accurate regarding the detection of clinically relevant colonic polyps exceeding 10 mm in size, with reported sensitivity and specificity values exceeding 95%. To further increase patient acceptance, strategies for fecal tagging have recently been developed. By modulating the signal of fecal material to be identical to the signal characteristics of the enema applied to distend the colon, fecal tagging in conjunction with MR colonography obviates the need for bowel cleansing. The review will describe the techniques underlying MR colonography and describe early clinical experience with fecal tagging techniques. PMID:12746264

Debatin, J; Lauenstein, T

2003-01-01

307

Nonlinearity of Helmholtz resonators  

NASA Technical Reports Server (NTRS)

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

Sirignano, W. A.

1972-01-01

308

Electron resonances in DIET  

NASA Astrophysics Data System (ADS)

The appearance of peaks or maxima in desorption yield functions, obtained by 5 to 20 eV electrons impinging from vacuum onto atomic or molecular solid films, reveals the formation of transient anions (i.e. electron resonances) at specific energies. Depending on the interaction of the incident electron with a particular atom or molecule and with the surrounding medium, the transient anion can cause desorption of a stable anion and one or more neutral fragments or only neutral particle ejection. The former process occurs when the transitory anionic state dissociates before autoionization, whereas decay by electron emission can, under certain circumstances, result in neutral atom or molecule desorption. Details on these mechanisms are given in this article. They are illustrated from desorption yield functions recorded for 5-20 eV electron impact on thin film targets made of pure Ar, CO 2, D 2O and mixtures of Ar with H 2O, O 2 and n-hexane.

Sanche, Léon

2000-04-01

309

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

310

Investigation of magnetic resonances for different split-ring resonator parameters and designs  

Microsoft Academic Search

We investigate the magnetic resonance of split-ring resonators (SRR) experimentally and numerically. The dependence of the geometrical parameters on the magnetic resonance frequency of SRR is studied. We further investigate the effect of lumped capacitors integrated to the SRR on the magnetic resonance frequency for tunable SRR designs. Different resonator structures are shown to exhibit magnetic resonances at various frequencies

Koray Aydin; Irfan Bulu; Kaan Guven; Maria Kafesaki; Costas M Soukoulis; Ekmel Ozbay

2005-01-01

311

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

312

Continuous layer gap plasmon resonators.  

PubMed

We demonstrate both theoretically and experimentally that a gold nanostrip supported by a thin dielectric (silicon dioxide) film and a gold underlay forms an efficient (Fabry-Perot) resonator for gap surface plasmons. Periodic nanostrip arrays are shown to exhibit strong and narrow resonances with nearly complete absorption and quality factors of ~15-20 in the near-infrared. Two-photon luminescence microscopy measurements reveal intensity enhancement factors of ~120 in the 400-nm-period array of 85-nm-wide gold strips atop a 23-nm-thick silica film at the resonance wavelength of ~770 nm. Excellent resonant characteristics, the simplicity of tuning the resonance wavelength by adjusting the nanostrip width and/or the dielectric film thickness and the ease of fabrication with (only) one lithography step required make the considered plasmonic configuration very attractive for a wide variety of applications, ranging from surface sensing to photovoltaics. PMID:21996871

Nielsen, Michael G; Gramotnev, Dmitri K; Pors, Anders; Albrektsen, Ole; Bozhevolnyi, Sergey I

2011-09-26

313

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

314

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

315

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

316

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

317

Optics design of the extraction lines for the MedAustron hadron therapy centre  

Microsoft Academic Search

The MedAustron hadron therapy centre will provide proton and carbon ion beams for tumour treatment. The accelerator complex is based on a synchrotron that will employ slow resonant extraction to provide beams with the time structure required for active scanning. Four medical treatment rooms and two research rooms are foreseen for the centre. The present paper describes the optics design

Michael Benedikt

2005-01-01

318

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

Microsoft Academic Search

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

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

2000-01-01

319

Resonant double photoionisation spectroscopy of magnesium  

NASA Astrophysics Data System (ADS)

Resonant triple-differential cross-section (TDCS) measurements on atomic magnesium on the 2p ? 3d resonance are presented. These measurements are similar to recent measurements made in strontium at the 4p ? 4d resonance [1].

Sokell, Emma; Safgren, Stephan; Bolognesi, Paola; Feyer, Vitaliy; Coreno, Marcello; Avaldi, Lorenzo

2012-11-01

320

Pressure modulated changes in resonance frequency of microchannel string resonators  

NASA Astrophysics Data System (ADS)

Resonating strings have shown promise in a variety of applications including micron-scale mass and temperature sensors. We present microchannel string resonators (MSRs) which have resonance frequency modulated by the internal gauge pressure of silicon nitride microchannels sitting atop the strings. We present an analytical model to predict the pressure sensitivity (Hz/kPa) of the first resonance frequency as well as experimental results for three identical MSRs. While the highest experimental sensitivity of one of the resonators is 5.19 Hz/kPa (0.5 Hz/mbar), the analytical model suggests sensitivity could increase by two orders of magnitude if the microchannels are fabricated at nanometer scale with a length of 10 ?m, a channel width of 600 nm, and a channel thickness of 50 nm. The average pressure resolution of the sensors is 0.4 kPa. These results are for a calibrated range of pressure from 50 kPa to 100 kPa (500 mbar to 1000 mbar). However, the analytical model shows that resonance frequency is a linear function of pressure over a range of several MPa, suggesting that the microchannel resonators could have a pressure sensing range (dynamic range) suitable for many applications.

Khan, M. F.; Knowles, B.; Dennison, C. R.; Ghoraishi, M. S.; Thundat, T.

2014-07-01

321

Functional properties of spice extracts obtained via supercritical fluid extraction.  

PubMed

In the present study the antioxidant, anticancer, and antimycobacterial activities of extracts from ginger (Zingiber officinale Roscoe), rosemary (Rosmarinus officinalis L.), and turmeric (Curcuma longa L.) were evaluated. The extracts were obtained using supercritical CO(2) with and without ethanol and/or isopropyl alcohol as cosolvent. The extracts' antioxidant power was assessed using the reaction between beta-carotene and linolenic acid, the antimycobacterial activity against M. tuberculosis was measured by the MABA test, and their anticancer action was tested against nine human cancer ancestries: lung, breast, breast resistant, melanoma, colon, prostate, leukemia, and kidney. The rosemary extracts exhibited the strongest antioxidant and the lowest antimycobacterial activities. Turmeric extracts showed the greatest antimycobacterial activity. Ginger and turmeric extracts showed selective anticancer activities. PMID:12696930

Leal, Patrícia F; Braga, Mara E M; Sato, Daisy N; Carvalho, João E; Marques, Marcia O M; Meireles, M Angela A

2003-04-23

322

Powered resonance tubes: resonance characteristics and actuation signal directivity  

NASA Astrophysics Data System (ADS)

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

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

2005-12-01

323

The Ex Project: Web Information Extraction Using Extraction Ontologies  

Microsoft Academic Search

Extraction ontologies represent a novel paradigm in web information extraction (as one of ‘deductive’ species of web mining)\\u000a allowing to swiftly proceed from initial domain modelling to running a functional prototype, without the necessity of collecting\\u000a and labelling large amounts of training examples. Bottlenecks in this approach are however the tedium of developing an extraction\\u000a ontology adequately covering the semantic

Martin Labský; Vojt?ch Svátek; Marek Nekvasil; Dušan Rak

324

Parasitic slow extraction of extremely weak beam from a high-intensity proton rapid cycling synchrotron  

NASA Astrophysics Data System (ADS)

This paper proposes a novel method to extract extremely weak beam from a high-intensity proton rapid cycling synchrotron (RCS) in the parasitic mode, while maintaining the normal fast extraction. The usual slow extraction method from a synchrotron by employing third-order resonance cannot be applied in a high-intensity RCS due to a very short flat-top at the extraction energy and the strict control on beam loss. The proposed parasitic slow extraction method moves the beam to scrape a scattering foil prior to the fast beam extraction by employing either a local orbit bump or momentum deviation or their combination, so that the halo part of the beam will be scattered. A part of the scattered particles will be extracted from the RCS and guided to the experimental area. The slow extraction process can last about a few milliseconds before the beam is extracted by the fast extraction system. The method has been applied to the RCS of China Spallation Neutron Source. With 1.6 GeV in the extraction energy, 62.5 ?A in the average current and 25 Hz in the repetition rate for the RCS, the proton intensity by the slow extraction method can be up to 2×104 protons per cycle or 5×105 protons per second. The extracted beam has also a good time structure of approximately uniform in a spill which is required for many applications such as detector tests. Detailed studies including the scattering effect in the foil, the local orbit bump by the bump magnets and dispersive orbit bump by modifying the RF pattern, the multi-particle simulations by ORBIT and TURTLE codes, and some technical features for the extraction magnets are presented.

Zou, Ye; Tang, Jingyu; Yang, Zheng; Jing, Hantao

2014-02-01

325

Lasing from active optomechanical resonators  

PubMed Central

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

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

2014-01-01

326

Garlic extract for HIV?  

PubMed

Garlic has been used for hundreds of years to treat fungal, parasitic, and viral infections, and has anti-inflammatory properties that show promise for prevention of cardiovascular disease. Researchers are focusing on an extract of garlic called ajoene which also appears to protect CD+ cells from attack by HIV early in the viral life cycle. At low concentrations, the drug appears to have little toxicity, and its anti-HIV activity is 45 times more powerful than the drug dextran sulfate. Ajoene is found only in fresh garlic and is not readily available. One researcher found that garlic impairs the activity of the liver enzymes that process protease inhibitors and raises the protease inhibitor levels. PMID:11365438

1998-05-01

327

Underground mineral extraction  

NASA Technical Reports Server (NTRS)

A method was developed for extracting underground minerals such as coal, which avoids the need for sending personnel underground and which enables the mining of steeply pitched seams of the mineral. The method includes the use of a narrow vehicle which moves underground along the mineral seam and which is connected by pipes or hoses to water pumps at the surface of the Earth. The vehicle hydraulically drills pilot holes during its entrances into the seam, and then directs sideward jets at the seam during its withdrawal from each pilot hole to comminute the mineral surrounding the pilot hole and combine it with water into a slurry, so that the slurried mineral can flow to a location where a pump raises the slurry to the surface.

Miller, C. G.; Stephens, J. B.

1980-01-01

328

Aqueous acetone extraction of cottonseed  

Microsoft Academic Search

Extraction of cottonseed flakes with acetone containing 25-30% water removes essentially all of the gossypol, most of the\\u000a free fatty acids, about half the raffinose, and negligible quanti-ties of neutral oil and protein. After drying and re-flaking\\u000a of the aqueous acetone extracted marc, the oil may be removed either by hexane extrac-tion or pressing to produce light-colored\\u000a meals exceptionally low

Walter A. Pons; Paul H. Eaves

1967-01-01

329

Ethanol production by extractive fermentation  

Microsoft Academic Search

The ideal method to produce a terminal metabolite inhibitor of cell growth and production is to remove and recover it from the fermenting broth as it is formed. Extractive fermentation is achieved in the case of ethanol production by coupling both fermentation and liquid-liquid extraction. The solvent of extraction is 1-dodecanol (or a mixture 1-dodecanol, 1-tetradecanol); study of the inhibitory

M. Minier; G. Goma

1982-01-01

330

Evaluation of the Chromium Resonance Parameters Including Resonance Parameter Covariance  

SciTech Connect

The intent of this work is to report the results and describe the procedures utilized to evaluate the chromium isotopes' cross sections, i.e., (50)Cr, (52)Cr, (53)Cr, and (54)Cr, for criticality safety applications. The evaluations were done in the resolved resonance region using the reduced Reich-Moore R-matrix formalism. The novel aspect of this evaluation is the inclusion of new transmission and capture cross-section measurements performed at the Oak Ridge Electron Linear Accelerator (ORELA) for energies below 100 keV and the extension of the (53)Cr energy region. The resonance analysis was performed with the multilevel R-matrix code, SAMMY, which utilizes the generalized least-squares technique based on the Bayes' theory. Complete sets of resonance parameters and resonance parameter covariance matrices (RPCMs) were obtained for each of the chromium isotopes from the SAMMY analysis of the experimental database.

Leal, Luiz C [ORNL; Derrien, Herve [ORNL; Guber, Klaus H [ORNL; Arbanas, Goran [ORNL; Wiarda, Dorothea [ORNL

2011-01-01

331

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

332

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

333

An astigmatic unstable resonator with an intracavity deformable mirror  

SciTech Connect

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

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

1991-01-01

334

Rigrod laser-pumped-laser resonator model: I. Theoretical considerations  

NASA Astrophysics Data System (ADS)

Dilute laser materials whose ion doping is minimized are attractive because Auger up-conversion is minimized, substantially lower heat fractions result and transverse or longitudinal gain and heat deposition gradients are reduced. In addition, amplified spontaneous emission (ASE) effects are minimized as well. Lasers using dilute laser materials, however, tend to have lowered efficiencies due to the difficulty in obtaining efficient absorption in laser crystals of reasonable length. This is primarily because of the use of simple single or double-passed pump absorption schemes. While this difficulty may be overcome using multi-passed absorption pump beams, as has been successfully demonstrated in connection with the development of thin-disc lasers, higher absorption and efficiency are obtained with added complexity and cost. In this paper, we present an alternative method in which a dilute or thin absorbing laser material is placed intra-cavity to a pump laser resonator. With the absorbing laser crystal acting as an effective outcoupler, we find that the highest absorption and resonator extraction efficiencies are obtained with the most dilute or thin materials when resonator mirrors of near unity reflectivity are used. This counter-intuitive result is explained by a corresponding long photon lifetime inside the laser resonator, which effectively multi-passes the absorbing laser crystal, leading to a very high absorption efficiency.

Brown, D. C.

2014-08-01

335

Neutron resonances in 166Ho  

NASA Astrophysics Data System (ADS)

We report the results of a high-resolution study of neutron resonances below 500 eV in 166Ho. We find nine previously unreported weak resonances at energies 24.79, 75.08, 119.98, 187.94, 210.86, 227.87, 235.94, 248.60, and 264.98 eV. Bayesian probability analysis of the widths indicates they are formed primarily by s-wave capture and are therefore negative-parity resonances. If they have measurable d-wave neutron widths, they are candidates for the fivefold correlation test of time reversal.

Huffman, P. R.; Frankle, C. M.; Gould, C. R.; Haase, D. G.; Harvey, J. A.; Roberson, N. R.; Weston, L. W.

1996-10-01

336

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

337

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, E.M.; Nunnally, W.C.

1985-06-19

338

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

339

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

340

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

341

Powered resonance tubes: resonance characteristics and actuation signal directivity  

Microsoft Academic Search

The powered resonance tube (PRT) actuator and its variants are new developments in active flow control (AFC) technology. The\\u000a PRT is attractive because it has no moving parts and can produce acoustic tones that have amplitudes greater than 150 dB over\\u000a a large frequency bandwidth. The first part of this paper deals with the resonance characteristics of the PRT as a

Shekhar Sarpotdar; Ganesh Raman; Alan B. Cain

2005-01-01

342

Interventional magnetic resonance imaging.  

PubMed

The development of minimally invasive surgical and interventional techniques has created a need for more accurate and sensitive image guidance and monitoring. Magnetic resonance imaging, with its superior soft tissue discrimination and multiplanar facilities, seems the obvious choice for an ideal image-guidance tool. Until recently, the employment of MRI in this role has been prevented by the physical constraints of conventional, closed-configuration machines. The problem has now been overcome by the development of an open design allowing both horizontal and vertical access to the patient in the scanner so that procedures can be performed concurrent with image acquisition. This configuration, together with the use of fast gradient echo sequences which can scan at speeds close to real time, means that a wide range of interventional procedures can be performed with on-line image guidance and monitoring. In addition, the versatility of the open design means that patients can assume physiological positions to allow dynamic joint imaging to be performed. This opens up a whole new field in the understanding of joint pathophysiology. This review article discusses these recent technological developments and their clinical applications. In particular, the potential role in guidance of biopsies, monitoring of thermal ablation techniques and applications in endoscopic surgery is outlined. PMID:9534721

Lamb, G M; Gedroyc, W M

1997-11-01

343

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

344

Resonant and non-resonant tunneling through a double barrier  

NASA Astrophysics Data System (ADS)

An explicit expression is obtained for the phase-time corresponding to tunneling of a (non-relativistic) particle through two rectangular barriers, both in the case of resonant and in the case of non-resonant tunneling. It is shown that the behavior of the transmission coefficient and of the tunneling phase-time near a resonance is given by expressions with "Breit-Wigner type" denominators. By contrast, it is shown that, when the tunneling probability is low (but not negligible), the non-resonant tunneling time depends on the barrier width and on the distance between the barriers only in a very weak (exponentially decreasing) way: This can imply in various cases, as well known, the highly superluminal tunneling associated with the so-called "generalized Hartman Effect": but we are now able to improve and modify the mathematical description of such an effect, and to compare more in detail our results with the experimental data for non-resonant tunneling of photons. Finally, as a second example, the tunneling phase-time is calculated, and compared with the available experimental results, in the case of the quantum-mechanical tunneling of neutrons through two barrier-filters at the resonance energy of the set-up. Our analysis appears to explain satisfactorily both sets of experiments.

Olkhovsky, V. S.; Recami, E.; Zaichenko, A. K.

2005-06-01

345

Resonance IR: a coherent multidimensional analogue of resonance Raman.  

PubMed

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

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

2014-05-01

346

Oil shale extraction using super-critical extraction  

NASA Technical Reports Server (NTRS)

Significant improvement in oil shale extraction under supercritical conditions is provided by extracting the shale at a temperature below 400 C, such as from about 250 C to about 350 C, with a solvent having a Hildebrand solubility parameter within 1 to 2 Hb of the solubility parameter for oil shale bitumen.

Compton, L. E. (inventor)

1983-01-01

347

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

348

Resonant and non-resonant microwave absorption as a probe of the magnetic dynamics and switching in spin valves  

NASA Astrophysics Data System (ADS)

We use the resonant and non-resonant microwave absorption to probe the dynamic and static magnetic parameters of weakly coupled spin valves. The sample series include spin valve structures with varying thickness of the non-magnetic metallic spacer and reference samples comprised only a free or fixed magnetic layer. Beside the common resonance absorption peaks, the observed microwave spectra present step-like features with hysteretic behavior. The latter effect is a direct manifestation of the interlayer coupling between the ferromagnetic layers and provides two static magnetic parameters, the switching field and coercivity of the fixed layer. The analysis of the microwave absorption spectra under in-plane rotation of the applied magnetic field at different spacer thicknesses permits a deeper insight in the magnetic interactions in this system as compared to the conventional magnetometry. We combine the standard Smit-Beljers formalism for the angular dependence of the resonance fields with a Landau-Lifshitz-Gilbert dynamics extended to describe in detail the intensity of microwave absorption in the spin valves. In this way, we extract a set of parameters for each layer including the effective magnetization and anisotropy, exchange bias and interlayer coupling, as well as Gilbert damping. The model reproduces well the experimental findings, both qualitatively and quantitatively, and the estimated parameters are in a reasonable agreement with the values known from the literature. The proposed theoretical treatment can be adopted for other multilayered dynamic systems as, e.g., spin-torque oscillators.

Timopheev, A. A.; Sobolev, N. A.; Pogorelov, Y. G.; Talalaevskij, A. V.; Teixeira, J. M.; Cardoso, S.; Freitas, P. P.; Kakazei, G. N.

2013-07-01

349

COMBINING NEUTRAL AND ACIDIC EXTRACTANTS FOR RECOVERING TRANSURANIC ELEMENTS FROM NUCLEAR FUEL  

SciTech Connect

We have been investigating a solvent extraction system that combines a neutral extractant--octyl(phenyl)-N,N-diisobutyl-carbamoylmethylphosphine oxide (CMPO)--with an acidic extractant--bis(2-ethylhexyl)phosphoric acid (HDEHP)--to form a single process solvent for separating Am and Cm from the other components of irradiated nuclear fuel. It was originally hypothesized that the extraction chemistry of CMPO would dominate under conditions of high acidity (> 1 M HNO3), resulting in co-extraction of the transuranic and lanthanide elements into the organic phase. Contacting the loaded solvent with a solution of diethylenetriaminepentaacetate (DTPA) buffered with lactic or citric acid at pH {approx}3 to 4 would result in a condition in which the HDEHP chemistry dominates. Although the data somewhat support this hypothesis, it is clear that there are interactions between the two extractants such that they do not act independently in the extraction and stripping regimes. We report here studies directed at determining the nature and extent of interaction between CMPO and HDEHP, the synergistic behavior of CMPO and HDEHP in the extraction of americium and neodymium, and progress towards determining the thermodynamics of this extraction system. Neodymium and americium behave similarly in the combined solvent system, with a significant synergy between CMPO and HDEHP in the extraction of both of these trivalent elements from lactate-buffered DTPA solutions. In contrast, a much weaker synergistic behaviour is observed for europium. Thus, investigations into the fundamental chemistry involved in this system have focused on the neodymium extraction. The extraction of neodymium has been systematically investigated, individually varying the HDEHP concentration, the CMPO concentration, or the aqueous phase composition. Thermodynamic modeling of the neodymium extraction system has been initiated. Interactions between CMPO and HDEHP in the organic phase must be taken into account in the thermodynamic modeling; such interactions have been quantified by nuclear magnetic resonance measurements.

Lumetta, Gregg J.; Neiner, Doinita; Sinkov, Sergey I.; Carter, Jennifer C.; Braley, Jenifer C.; Latesky, Stanley; Gelis, Artem V.; Tkac, Peter; Vandegrift, George F.

2011-10-03

350

Microring Resonators for Biochemical Sensing  

NASA Astrophysics Data System (ADS)

Resonant microcavities have recently become popular for research in optical biosensor applications. Whispering Gallery Mode (WGM) microresonators are preferred as active sensing surfaces due to their high-Q values which provide measurable shifts in mode frequencies as surface characteristics change. In this study, the active sensing surface is a microring resonator vertically coupled to waveguides and mounted to a flow cell. Resonant transmission at a specific wavelength is measured as a function of time as flow solution concentrations are varied, and high sensitivity to surface refractive index changes and repeatability are demonstrated. To investigate Avidin-Biotin binding, surfaces are modified with silane and Avidin, followed by Biotinylated Lectin flow. Surface characterization performed by ellipsometry and XPS shows successful deposition of discrete layers. Preliminary results show detection of binding and near complete regeneration of the sensing surface, indicating a high potential for sensitive and selective biosensor applications of microring resonators.

Yalcin, Ayca; Popat, Ketul C.; Chbouki, Nabil; Unlu, M. Selim; Goldberg, Bennett B.

2005-03-01

351

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

352

Finite aperture waveguide laser resonators  

NASA Technical Reports Server (NTRS)

A general theory of finite aperture waveguide laser resonators is developed which represents the external reflectors by matrices which couple linearly polarized waveguide modes having the same azimuthal symmetry. The theory allows the determination of resonator efficiency, resonator frequencies, and laser near and far field patterns. Computations of the coupling loss for the fundamental waveguide mode as a function of mirror curvature, separation, and aperture are in agreement with recent infinite aperture calculations in the limit of large apertures and indicate three low-loss configurations: large radius of curvature mirrors close to the guide; large radius of curvature mirrors centered at the guide entrance; and generally smaller curvature mirrors separated by half their curvature from the guide entrance. Design guidelines for construction of high efficiency CO2, CO and He-Ne waveguide laser resonators are summarized in tabular form.

Degnan, J. J.; Hall, D. R.

1973-01-01

353

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

354

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

355

Recoilless Resonant Capture of Antineutrinos  

E-print Network

Resonant capture of antineutrinos can be accomplished by exploiting the monoenergetic antineutrinos emitted in bound state beta-decay. Extending this idea, I explore conditions for recoilless resonant capture in the system 3H - 3He. Observation of such transitions can set the stage for placing stringent limits on the neutrino parameter theta-13 on an ultra-short baseline of ~9 m and for observing the gravitational red shift of neutrinos

R. S. Raghavan

2005-11-15

356

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

357

Empathy in schizophrenia: impaired resonance  

Microsoft Academic Search

Resonance is the phenomenon of one person unconsciously mirroring the motor actions as basis of emotional expressions of another\\u000a person. This shared representation serves as a basis for sharing physiological and emotional states of others and is an important\\u000a component of empathy. Contagious laughing and contagious yawning are examples of resonance. In the interpersonal contact with\\u000a individuals with schizophrenia we

Helene Haker; Wulf Rössler

2009-01-01

358

UHF SAW Resonators and Applications  

Microsoft Academic Search

Surface acoustic wave (SAW) resonators suitable for systems applications are being produced in our laboratory at frequencies as high as 1.43 GHz. These two-port single-pole devices, which have distortionless response characteristics and high Q values [Q >-lO,400\\/F(GHz)l may be used to stabilize UHF oscil!l!ators or as narrowband filters. These resonators have the advantages of small size, low matched insertion loss

William J. Tanski

1980-01-01

359

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

360

Coupling effects at the ? z = {3}/{4} resonance in a three-sector superconducting cyclotron  

NASA Astrophysics Data System (ADS)

The fourth-order resonance ? z = {3}/{4} often occurs in the pre-extraction region of three-sector superconducting cyclotrons, and acceleration through this resonance can deform the vertical (and radial) phase space of the beam. The phase-space properties near the resonance have been explored using an improved version of the Z4 Orbit Code and magnetic field data from the K1200 superconducting cyclotron at this laboratory. The orbit code results have been compared with those obtained from a standard theoretical analysis based on an expansion of the Hamiltonian. This comparison shows that relatively good agreement can be obtained if and only if certain third-order coupling effects are included in the theory. These effects are associated with particular coupling resonances that are not very far from the operating point.

Jeon, Dong-o.; Gordon, M. M.

1994-09-01

361

P-wave resonant state of the He4? hypernucleus in the 4He (K- ,?-) reaction  

NASA Astrophysics Data System (ADS)

We theoretically investigate a possible existence of a p-wave He4? resonant state with J? =1-, T ? 1 / 2 above the ? threshold, using a coupled (3 N- ?) + (3 N- ?) model with a spreading potential. We calculate inclusive and ?-? conversion ?- spectra in a 4He (K- ,?-) reaction at 1.5 GeV/c, ?lab = 4- 12 ° by the Green's function method in a distorted-wave impulse approximation. The pole position for the p-wave ? resonant state in He4? is determined on the Riemann sheets in the complex E plane. The result shows that a peak of the He4? resonant state is clearly obtained in the conversion spectra above the ? threshold, and that the angular distributions of these spectra enable extraction of the contribution of the resonant state from the ?- spectra. Effects of the ?-nucleus potential and the interference between ? and ? on the spectra are also discussed.

Harada, Toru; Hirabayashi, Yoshiharu

2015-01-01

362

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

NASA Astrophysics Data System (ADS)

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 particles 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 120Sn 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 with these methods are found for the energies and widths of single-neutron resonant states.

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

2014-11-01

363

On fine orbit selection for particular geodetic and oceanographic missions involving passage through resonances  

NASA Astrophysics Data System (ADS)

The identification of mean semi-major axes (suitably defined) for satellite orbits to satisfy a variety of requirements for geodesy, geophysics and oceanography, in terms of repeat orbits (with orbital resonances), is investigated. Various options for the definition of semi-major axis, from the viewpoint of satellite dynamics, are described. Simple simulations of the expected resonant changes in inclination are presented, and tools for the analysis of orbit resonances to extract certain lumped harmonic coefficients of the geopotential (e.g. from the very precise CHAMP orbit) are resurrected. Finally, a preliminary example of the 46th-order resonance analysis possible for CHAMP, based on the mean orbital elements produced by GFZ (GeoForschungs Zentrum) for ephemeris prediction, is presented.

Kloko?ník, J.; Kostelecký, J.; Gooding, R. H.

2003-05-01

364

Fractal dimension of cerebral surfaces using magnetic resonance images  

SciTech Connect

The calculation of the fractal dimension of the surface bounded by the grey matter in the normal human brain using axial, sagittal, and coronal cross-sectional magnetic resonance (MR) images is presented. The fractal dimension in this case is a measure of the convolutedness of this cerebral surface. It is proposed that the fractal dimension, a feature that may be extracted from MR images, may potentially be used for image analysis, quantitative tissue characterization, and as a feature to monitor and identify cerebral abnormalities and developmental changes.

Majumdar, S.; Prasad, R.R.

1988-11-01

365

Resonances in coupled ?K,?K scattering from quantum chromodynamics  

E-print Network

Using first-principles calculation within Quantum Chromodynamics, we are able to determine a pattern of strangeness=1 resonances which appear as complex singularities within coupled $\\pi K$, $\\eta K$ scattering amplitudes. We make use of numerical computation in the lattice discretized approach to the quantum field theory with light quark masses corresponding to $m_\\pi \\sim 400\\, \\textrm{MeV}$ 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.

Jozef J. Dudek; Robert G. Edwards; Christopher E. Thomas; David J. Wilson

2014-10-23

366

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

367

Resonances in coupled ?K-?K scattering from quantum chromodynamics.  

PubMed

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. PMID:25396360

Dudek, Jozef J; Edwards, Robert G; Thomas, Christopher E; Wilson, David J

2014-10-31

368

Micro-machined resonator oscillator  

DOEpatents

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

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

1994-01-01

369

Micro-machined resonator oscillator  

DOEpatents

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

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

1994-08-16

370

Empathy in schizophrenia: impaired resonance.  

PubMed

Resonance is the phenomenon of one person unconsciously mirroring the motor actions as basis of emotional expressions of another person. This shared representation serves as a basis for sharing physiological and emotional states of others and is an important component of empathy. Contagious laughing and contagious yawning are examples of resonance. In the interpersonal contact with individuals with schizophrenia we can often experience impaired empathic resonance. The aim of this study is to determine differences in empathic resonance-in terms of contagion by yawning and laughing-in individuals with schizophrenia and healthy controls in the context of psychopathology and social functioning. We presented video sequences of yawning, laughing or neutral faces to 43 schizophrenia outpatients and 45 sex- and age-matched healthy controls. Participants were video-taped during the stimulation and rated regarding contagion by yawning and laughing. In addition, we assessed self-rated empathic abilities (Interpersonal Reactivity Index), psychopathology (Positive and Negative Syndrome Scale in the schizophrenia group resp. Schizotypal Personality Questionnaire in the control group), social dysfunction (Social Dysfunction Index) and executive functions (Stroop, Fluency). Individuals with schizophrenia showed lower contagion rates for yawning and laughing. Self-rated empathic concern showed no group difference and did not correlate with contagion. Low rate of contagion by laughing correlated with the schizophrenia negative syndrome and with social dysfunction. We conclude that impaired resonance is a handicap for individuals with schizophrenia in social life. Blunted observable resonance does not necessarily reflect reduced subjective empathic concern. PMID:19377866

Haker, Helene; Rössler, Wulf

2009-09-01

371

Lasing from active optomechanical resonators.  

PubMed

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

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

2014-01-01

372

Sterilization of Extracted Human Teeth.  

ERIC Educational Resources Information Center

At present, there is no specific recommendation for sterilization of extracted human teeth used in dental technique courses. The purpose of this study was to determine whether autoclaving would be effective in the sterilization of extracted teeth without compromising the characteristics that make their use in clinical simulations desirable. (MLW)

Pantera, Eugene A., Jr.; Schuster, George S.

1990-01-01

373

TRACE EXTRACTION FROM OBLIQUE IONOGRAMS  

E-print Network

TRACE EXTRACTION FROM OBLIQUE IONOGRAMS M. Roughan 1 and D.J. Percival 2 1 Cooperative Research an oblique ionogram and select the F2­layer o­mode trace for input to an inversion algorithm. MOTIVATION To automate ionogram trace extraction, as part of a real­time propagation advice algorithm for HF radar

Roughan, Matthew

374

Extraction of neptunium by trilaurylamine  

Microsoft Academic Search

Trilaurylamine (TLA) is considered as useful solvent for the final purification of plutonium and neptunium. As TLA is considered as an alternate possible extractant for the final purification of plutonium and neptunium at Tarapur Reprocessing Plant under construction, it was considered necessary to study the optimum conditions for the extraction of neptunium using TLA.

S. K. Patil; R. Swarup; M. V. Ramaniah; N. Srinivasan

1972-01-01

375

Supercritical multicomponent solvent coal extraction  

NASA Technical Reports Server (NTRS)

The yield of organic extract from the supercritical extraction of coal with larger diameter organic solvents such as toluene is increased by use of a minor amount of from 0.1 to 10% by weight of a second solvent such as methanol having a molecular diameter significantly smaller than the average pore diameter of the coal.

Corcoran, W. H.; Fong, W. S.; Pichaichanarong, P.; Chan, P. C. F.; Lawson, D. D. (inventors)

1983-01-01

376

Integrated modeling of electron cyclotron resonance ion sources and charge breeders with GEM, MCBC, and IonEx  

SciTech Connect

A numerical toolset to help in understanding physical processes in the electron cyclotron resonance charge breeder (ECRCB) and further to help optimization and design of current and future machines is presented. The toolset consists of three modules (Monte Carlo charge breeding code, generalized electron cyclotron resonance ion source modeling, and ion extraction), each modeling different processes occurring in the ECRCB from beam injection to extraction. The toolset provides qualitative study, such as parameter studies, and scaling of the operation, and physical understanding in the ECRCB. The methodology and a sample integrated modeling are presented.

Kim, J. S.; Zhao, L.; Cluggish, B. P.; Galkin, S. A.; Grubert, J. E. [FAR-TECH, Inc., 3550 General Atomics Court, MS 15-155, San Diego, California 92121 (United States); Pardo, R. C.; Vondrasek, R. C. [Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2010-02-15

377

Detection of graphene microelectromechanical system resonance  

NASA Astrophysics Data System (ADS)

We present an experimental setup for fast detection of resonances of graphene microelectromechanical structures of different quality. The relatively simple technique used to read-out of the resonance frequency is the main advantage of the proposed system. The resolution is good enough to detect vibrations of the graphene resonator with the quality factor of ˜24 and resonance frequency of 104 MHz.

Wiesner, M.; Lindvall, N.; Yurgens, A.

2014-12-01

378

DIVERSE RESONANCE TUNING STRATEGIES FOR WOMEN SINGERS  

E-print Network

that can increase loudness with little extra vocal effort [2,3,4]. Furthermore, it has been suggested resonances (R1 and R2) of the vocal tract. This allows diverse techniques of resonance tuning. Resonances by the first two acoustic resonances of the vocal tract, with frequencies R1 and R2. The resultant formants

Paris-Sud XI, Université de

379

Electron current extraction from a permanent magnet waveguide plasma cathode  

SciTech Connect

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. [University of Michigan, Ann Arbor, Michigan 48109 (United States); Kamhawi, H. [NASA Glenn Research Center, Cleveland, Ohio 44135 (United States)

2011-09-15

380

Swelling of coal extracts  

SciTech Connect

There has been a rapid growth in research that deals with the solvent swelling of coal. Much of this effort has been directed toward the application of modern polymer and network theories to coal, with the purpose of better understanding their network structures. One of the most fundamental parameters of a network structure is the average molecular weight between crosslinks. Several research groups have attempted to estimate this for coal from solvent swelling data and the Flory-Rehner equation. The equation incorporates both the Flory-Huggins theory of polymer solutions and the Gaussian elastic network theory. An important parameter embodied in the Flory-Huggins theory is the interaction parameter, /chi/. /chi/ is a thermodynamic parameter describing the energetics of the polymer-solvent interaction. Very few reliable methods have been developed to evaluate /chi/ for coal-solvent systems. It is the purpose of this research to develop a reliable method for its evaluation. The solvent swelling of coal extracts; utilizing benzene as the solvent, is discussed. 9 figs., 6 tabs.

Green, T.K.; Chamberlin, J.M.; Lopez-Froedge, L.; Ball, J.E.

1989-01-01

381

Extraction of Questions Behind Messages  

NASA Astrophysics Data System (ADS)

To overcome the limitation of conventional text-mining approaches in which frequent patterns of word occurrences are to be extracted to understand obvious user needs, this paper proposes an approach to extracting questions behind messages to understand potential user needs. We first extract characteristic case frames by comparing the case frames constructed from target messages with the ones from 25M sentences in the Web and 20M sentences in newspaper articles of 20 years. Then we extract questions behind messages by transforming the characteristic case frames into interrogative sentences based on new information and old information, i.e., replacing new information with WH-question words. The proposed approach is, in other words, a kind of classification of word occurrence pattern. Qualitative evaluations of our preliminary experiments suggest that extracted questions show problem consciousness and alternative solutions -- all of which help to understand potential user needs.

Matsumura, Naohiro; Kawahara, Daisuke; Okamoto, Masashi; Kurohashi, Sadao; Nishida, Toyoaki

382

Electron cyclotron resonance charge breeder (invited)  

NASA Astrophysics Data System (ADS)

Initially developed for radioactive ion beam production, the electron cyclotron resource (ECR) charge breeder shows that the beam injection of a primary beam inside an ECR ion source is a very general process for beam production. In this article we will review the latest results obtained on the ISN Grenoble test bench for the production of clockwise (CW) or pulsed metallic ion beams with the so-called "1+/n+" method. New results are given for CW operation where the efficiency is particularly optimized for application to multicharged radioactive ion production (for example, 3.5% for Zn1+?Zn9+, 4.2% for Pb1+?Pb24+, 5% for Rb1+?Rb15+). Different ion sources have been used to study the variation of the efficiency as a function of the energy of the 1+ primary beam. Charge state distributions are especially measured for Pb and Rb ions. A new mode of operation, the electron cyclotron resonance ion trap breeder/buncher, which permits the trapping and the bunching of the n+ ion beam is demonstrated and experimentally verified. The injection of a 400 nAeRb1+ ion beam leads to a 11.5 ?Ae peak current of the Rb15+ ion beam extracted during the first ms. The temporal evolution of the cumulated particle transformation and trapping efficiency is measured in the case of Rb15+. This new method shows that it is possible to modify the time structure of the injected beam, just by trapping the ions inside the plasma and re-extracting them by using the "afterglow pulsed mode." It will also be shown that it is possible to produce "multi-charged metallic ions" by using a primary source for the dissociation of a complex molecule and then by injecting the low charge state beam inside the multicharged electron cyclotron resonance ion source. A preliminary example will be presented for the production of U26+ by injection of U3+ obtained from dissociation of UF6 gas.

Sortais, P.; Bruandet, J. F.; Bouly, J. L.; Chauvin, N.; Curdy, J. C.; Geller, R.; Lamy, T.; Sole, P.; Vieux-Rochaz, J. L.

2000-02-01

383

H Loop shaping control for PLL-based mechanical resonance tracking in NEMS resonant mass sensors  

E-print Network

H Loop shaping control for PLL-based mechanical resonance tracking in NEMS resonant mass sensors--A simple dynamic detection of the resonance frequency shift in NEMS resonant mass sensors is described the resonant oscillations. The sensor is driven directly by the VCO's output for which the control signal

Boyer, Edmond

384

Observation of ferromagnetic resonance in a microscopic sample using magnetic resonance force microscopy  

E-print Network

can be measured. Employing magnetic resonance force microscopy MRFM we have observed a strong FMRObservation of ferromagnetic resonance in a microscopic sample using magnetic resonance force resonance force microscopy MRFM . The large signal intensity in the resonance spectra suggests that MRFM

Hammel, P. Chris

385

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

386

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

387

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

388

Tubular Surface Segmentation for Extracting Anatomical Structures From Medical Imagery  

PubMed Central

This work provides a model for tubular structures, and devises an algorithm to automatically extract tubular anatomical structures from medical imagery. Our model fits many anatomical structures in medical imagery, in particular, various fiber bundles in the brain (imaged through diffusion-weighted magnetic resonance (DW-MRI)) such as the cingulum bundle, and blood vessel trees in computed tomography angiograms (CTAs). Extraction of the cingulum bundle is of interest because of possible ties to schizophrenia, and extracting blood vessels is helpful in the diagnosis of cardiovascular diseases. The tubular model we propose has advantages over many existing approaches in literature: fewer degrees-of-freedom over a general deformable surface hence energies defined on such tubes are less sensitive to undesirable local minima, and the tube (in 3-D) can be naturally represented by a 4-D curve (a radius function and centerline), which leads to computationally less costly algorithms and has the advantage that the centerline of the tube is obtained without additional effort. Our model also generalizes to tubular trees, and the extraction algorithm that we design automatically detects and evolves branches of the tree. We demonstrate the performance of our algorithm on 20 datasets of DW-MRI data and 32 datasets of CTA, and quantify the results of our algorithm when expert segmentations are available. PMID:21118754

Sundaramoorthi, Ganesh; Tannenbaum, Allen

2011-01-01

389

Optimized Brain Extraction for Pathological Brains (optiBET)  

PubMed Central

The study of structural and functional magnetic resonance imaging data has greatly benefitted from the development of sophisticated and efficient algorithms aimed at automating and optimizing the analysis of brain data. We address, in the context of the segmentation of brain from non-brain tissue (i.e., brain extraction, also known as skull-stripping), the tension between the increased theoretical and clinical interest in patient data, and the difficulty of conventional algorithms to function optimally in the presence of gross brain pathology. Indeed, because of the reliance of many algorithms on priors derived from healthy volunteers, images with gross pathology can severely affect their ability to correctly trace the boundaries between brain and non-brain tissue, potentially biasing subsequent analysis. We describe and make available an optimized brain extraction script for the pathological brain (optiBET) robust to the presence of pathology. Rather than attempting to trace the boundary between tissues, optiBET performs brain extraction by (i) calculating an initial approximate brain extraction; (ii) employing linear and non-linear registration to project the approximate extraction into the MNI template space; (iii) back-projecting a standard brain-only mask from template space to the subject’s original space; and (iv) employing the back-projected brain-only mask to mask-out non-brain tissue. The script results in up to 94% improvement of the quality of extractions over those obtained with conventional software across a large set of severely pathological brains. Since optiBET makes use of freely available algorithms included in FSL, it should be readily employable by anyone having access to such tools. PMID:25514672

Lutkenhoff, Evan S.; Rosenberg, Matthew; Chiang, Jeffrey; Zhang, Kunyu; Pickard, John D.; Owen, Adrian M.; Monti, Martin M.

2014-01-01

390

Silhouette Extraction Silhouettes in Hough Space  

E-print Network

Silhouette Extraction Silhouettes in Hough Space Results Conclusions Silhouette Extraction in Hough Olson and Hao Zhang Silhouette Extraction in Hough Space #12;Silhouette Extraction Silhouettes in Hough Space Results Conclusions Outline 2 1 Silhouette Extraction Defining the Problem Previous Work 2

Zhang, Richard "Hao"

391

Method of purifying neutral organophosphorus extractants  

DOEpatents

A method for removing acidic contaminants from neutral mono and bifunctional organophosphorous extractants by contacting the extractant with a macroporous cation exchange resin in the H.sup.+ state followed by contact with a macroporous anion exchange resin in the OH.sup.- state, whereupon the resins take up the acidic contaminants from the extractant, purifying the extractant and improving its extraction capability.

Horwitz, E. Philip (Naperville, IL); Gatrone, Ralph C. (Naperville, IL); Chiarizia, Renato (Rome, IT)

1988-01-01

392

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

393

Endovascular extraction techniques for pacemaker and ICD lead extraction  

PubMed Central

In the last few years, comprehensive endovascular techniques have been developed to extract chronically implanted pacemaker and defibrillator leads. It is important that referring physician have knowledge of the advantages and limitations of the different techniques. In this paper we discuss the techniques and results of the currently used endovascular extraction techniques. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6Figure 7

Bracke, F.A.; Meijer, A.; van Gelder, B.

2001-01-01

394

Coal extraction by aprotic dipolar solvents. Final report. [Tetramethylurea, hexa-methylphosphoramide  

SciTech Connect

The overall goals of this project were to examine the rate and amount of extraction of coals at low temperature by a class of solvents with a generic structure to include tetramethylurea (TMU) and hexa-methylphosphoramide (HMPA) and to examine the nature of the extracted coal chemicals. The class of solvents with similar action, however, can be classified as aprotic, base solvents or, somewhat more broadly, specific solvents. The action of solvents by this last classification was then examined to postulate a mechanism of attack. Experimental work was conducted to explain the specific solvent attack including (1) pure solvent extraction, (2) extraction in mixtures with otherwise inert solvents and inhibitors, and (3) extraction with simultaneous catalytic enhancement attempts including water-gas shift conversion. Thus nuclear magnetic resonance (NMR) and gas-chromatograph mass spectrometer (GC-MS) analysis of extract molecules and extraction with high-pressure CO in TMU (plus 2% H2O) was performed. Effects of solvent additives such as cumene and quinone of large amounts of inert solvents such as tetralin, liminone, or carbon disulfide on extraction were also determined. Results are discussed. 82 refs., 36 figs., 37 tabs.

Sears, J T

1985-12-01

395

Evaluation of the antioxidant, anti-inflammatory, and anticancer activities of Euphorbia hirta ethanolic extract.  

PubMed

This study evaluated the chemical composition, antioxidant, anti-inflammatory and anticancer activities of a Euphorbia hirta L. extract. The antioxidant activities of whole E. hirta ethanol extract were determined by electron spin resonance spectrophotometric analysis of 1,1-diphenyl-2-picryl-hydrazyl (DPPH), hydroxyl, and alkyl radical levels and by using an online high-performance liquid chromatography (HPLC)-2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assay. The E. hirta ethanol extract (0.5 mg/mL) exhibited DPPH-scavenging activity of 61.19% ± 0.22%, while the positive control (0.5 mg/mL ascorbic acid) had 100% ± 0.22% activity. The concentration of the extract required to trap 50% of DPPH (IC50) was 0.205 mg/mL. Online HPLC analysis of the extract also showed strong antioxidant activity. The anti-inflammatory activity of the E. hirta extract was assessed in lipopolysaccharide-induced RAW 264.7 macrophages. The anti-inflammatory activity was highest in the presence of 200 µg/mL E. hirta extract, and nitric oxide production was decreased significantly (p < 0.05). The extract also showed selective anticancer activity at a concentration of 100 µg/mL (p < 0.05). These results indicated that E. hirta may warrant further investigation for the development of antioxidant, anti-inflammatory, and anticancer herbal medications. PMID:25225720

Sharma, Neelesh; Samarakoon, Kalpa W; Gyawali, Rajendra; Park, Yang-Ho; Lee, Sung-Jin; Oh, Sung Jong; Lee, Tae-Hoon; Jeong, Dong Kee

2014-01-01

396

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

397

Active vibration control using delayed resonant feedback  

NASA Astrophysics Data System (ADS)

Delayed feedback (DF) control is a well-established technique to suppress single frequency vibration of a non-minimum phase system. Modal control is also a well-established technique to control multiple vibration modes of a minimum phase system. In this paper these techniques are combined to simultaneously suppress multiple vibration modes of a non-minimum phase system involving a small time delay. The control approach is called delayed resonant feedback (DRF) where each modal controller consists of a modal filter to extract the target mode signal from the vibration response, and a phase compensator to account for the phase delay of the mode. The methodology is first discussed using a single mode system. A multi-mode system is then studied and experimental results are presented to demonstrate the efficacy of the control approach for two modes of a beam. It is shown that the system behaves as if each mode under control has a dynamic vibration absorber attached to it, even though the actuator and the sensor are not collocated and there is a time delay in the control system.

Kim, Sang-Myeong; Brennan, Michael J.

2013-09-01

398

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

399

A Simply Fruity DNA Extraction  

NSDL National Science Digital Library

In this activity, learners extract DNA from a strawberry and discover that DNA is in the food they eat. Learners use simple materials to break open the cells of a strawberry and see DNA with their very own eyes.

Mission Science Workshop

2012-01-01

400

DNA Extraction & Staging Laboratory (DESL)  

Cancer.gov

As part of the Cancer Genomics Research Laboratory (CGR), the DNA Extraction and Staging Laboratory (DESL) located in Frederick, MD, is responsible for the preparation of samples for investigators at NCI's Division of Cancer Epidemiology and Genetics (DCEG).

401

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

402

Extraction of N* information from the limited p(gamma,K+)Lambda data set  

E-print Network

Nucleon resonance information is often obtained from fitting hadrodynamical model calculations to data, where model parameters such as resonance coupling constants are the free parameters in the fitting procedure. For reactions with a limited data set, such as p(gamma, K+)Lambda, complications in the extraction of reliable N* information occur not only through theoretical uncertainties, but also due to technical difficulties in the fitting procedure. In this article we outline a fitting strategy based on a genetic algorithm and illustrate the kind of ambiguities which can arise.

S. Janssen; D. G. Ireland; J. Ryckebusch

2003-02-18

403

Heavy metals extraction by microemulsions.  

PubMed

The objective of this study is the heavy metal extraction by microemulsion, using regional vegetable oils as surfactants. Firstly, the main parameters, which have influence in the microemulsion region, such as: nature of cosurfactant, influence of cosurfactant (C)/surfactant (S) ratio and salinity were studied, with the objective of choosing the best extraction system. The extraction/reextraction process by microemulsion consists of two stages. In the first one, the heavy metal ion present in the aqueous phase is extracted by the microemulsion. In a second step, the reextraction process occurs: the microemulsion phase, rich in metal, is acidified and the metal is recovered in a new aqueous phase, with higher concentration. The used system had the following parameters: surfactant-saponified coconut oil; cosurfactant-n-butanol; oil phase-kerosene; C/S ratio=4; salinity-2% (NaCl); temperature of 27+/-1 degrees C; water phase-aqueous solution that varied according to the heavy metal in study (Cr, Cu, Fe, Mn, Ni and Pb). A methodology of experimental planning was used (Scheffé Net) to study the behavior of the extraction in a chosen domain. The extraction was accomplished in one step and yielded extraction percentage higher than 98% for all metals. In the reextraction HCl-8M was used as reextraction agent and the influence of the pH and time were verified. This work showed the great efficiency of the microemulsion, indicating that it is possible to extract selectively the heavy metals from the aqueous phase. PMID:12753848

Dantas, T N Castro; Dantas Neto, A A; Moura, M C P A; Barros Neto, E L; Forte, K R; Leite, R H L

2003-06-01

404

Liquid-Liquid Extraction Processes  

E-print Network

tries; a modern example of such use is the removal of caffeine from coffee beans by the use of super critical carbon dioxide solvent. There are many more examples of extraction applications that could be mentioned, but the above should provide some.... Insolubility of solvent. If the solvent is too soluble in the raffinate, signifi cant solvent losses can occur. 5. Recoverability. It is desirable to make a clean separation of extractant and solvent in the stripper, without excessive energy requirements...

Fair, J. R.; Humphrey, J. L.

1983-01-01

405

Lima Bean Bacteria DNA Extraction  

NSDL National Science Digital Library

This laboratory exercise is designed to show learners how DNA can easily be extracted from lima bean bacteria. 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.

Lana Hays

2009-01-01

406

1. EXTRACTING FROM NOISY DATA  

E-print Network

Knowledge extraction (KE) efforts have often used corpora of heavily edited writing and sources written to provide the desired knowledge (e.g., newspapers or textbooks). However, the proliferation of diverse, up-to-date, unedited writing on the Web, especially in weblogs, offers new challenges for KE tools. We describe our efforts to extract general knowledge implicit in this noisy data and examine whether such sources can be an adequate substitute for resources like Wikipedia.

Jonathan Gordon; Benjamin Van Durme; Lenhart Schubert

407

Work extraction from tripartite entanglement  

E-print Network

The work extractable from correlated bipartite quantum systems can be used to distinguish entanglement from classical correlation. A natural question is now whether it can be generalised to multipartite systems. In this paper, we devise a protocol to distinguish the GHZ, the W, and separable states in terms of the thermodynamically extractable work under local operations and classical communication, and compare the results with those obtained from Mermin's inequalities.

Vincent Viguie; Koji Maruyama; Vlatko Vedral

2005-04-20

408

Interventional Cardiovascular Magnetic Resonance Imaging  

PubMed Central

Cardiovascular magnetic resonance (CMR) combines excellent soft-tissue contrast, multiplanar views, and dynamic imaging of cardiac function without ionizing radiation exposure. Interventional cardiovascular magnetic resonance (iCMR) leverages these features to enhance conventional interventional procedures or to enable novel ones. Although still awaiting clinical deployment, this young field has tremendous potential. We survey promising clinical applications for iCMR. Next, we discuss the technologies that allow CMR-guided interventions and, finally, what still needs to be done to bring them to the clinic. PMID:19909937

Saikus, Christina E.; Lederman, Robert J.

2010-01-01

409

Ruthenium pure quadrupole resonance spectroscopy  

NASA Astrophysics Data System (ADS)

The unique chemistry of ruthenium and consequent potential importance of the quadrupole coupling constants and asymmetry parameters of 99Ru and 101Ru has prompted us to initiate an apparently original investigation of the pure nuclear quadrupole resonance spectroscopy of these two isotopes. A means for prediction of the expected resonance frequencies based on Mossbauer data is given and detailed circuit diagrams of a spectrometer which has been constructed primarily for ruthenium studies are presented. Preliminary searches carried out for ruthenium tris-acetylacetonate and bis-ruthenium tetroxide have so far failed to yield signals. Possible explanations for this are discussed and the value of continuing the work defended.

Carter, J. C.; Good, M. L.

410

Loss mechanisms in resonant spectrophones  

SciTech Connect

Quality factors and resonant frequencies of a resonant spectrophone have been measured as a function of pressure and the results compared to theoretical predictions which took into account classical surface and volumetric losses and molecular relaxation. Buffer gases investigated included the five nobel gases, H/sub 2/, N/sub 2/, O/sub 2/, CO/sub 2/, N/sub 2/O, and SF/sub 6/. Typically 95% of the cavity losses were accounted for theoretically. Frequency shifts due to relaxational dispersion, nonideal gas behavior, and classical boundary layer effects were observed; all behaved as predicted by theory.

Johnson, R.H.; Gerlach, R.; Thomas, L.J. III; Amer, N.M.

1982-01-01

411

Chemical extraction of mixed waste  

SciTech Connect

IT Corporation was contracted to conduct treatability studies on low level radioactive and mixed waste. A remedial investigation was initiated to develop remedial actions to control the impacts on human health and the environment. Several alternative technologies were investigated for the remediation of waste stored on site. The treatment technologies investigated by IT consisted of chemical extraction, cement based stabilization, vitrification, and soil washing. This paper focuses on the chemical extraction study. The major constituents of concern were radium, lead, and uranium. A tiered experimental approach was used that emulates the EPA`s remedy screening and remedy selection phases. Hydrochloric acid, nitric acid, acetic acid, EDTA, and KCl solutions were used to extract the radioactive components. EDTA was the most effective reagent to decrease the total activity of the waste. Acetic acid was about 80 percent as effective as hydrochloric and nitric acids. The largest radioactivity decrease was realized from sequential extractions using combination of acids with EDTA or KCl with EDTA. The TCLP of the chemically extracted material met the TC regulatory requirements. The radium concentration in the extracted material was decreased by greater than 95 percent.

Stine, E.F. Jr.; Morren, C.E.

1994-12-31

412

Stochastic resonance in electrical circuits. I. Conventional stochastic resonance  

Microsoft Academic Search

Stochastic resonance (SR), a phenomenon in which a periodic signal in a nonlinear system can be amplified by added noise, is introduced and discussed. Techniques for investigating SR using electronic circuits are described in practical terms. The physical nature of SR, and the explanation of weak-noise SR as a linear response phenomenon, are considered. Conventional SR, for systems characterized by

Dmitrii G. Luchinsky; Riccardo Mannella; Peter V. E. McClintock; Nigel G. Stocks

1999-01-01

413

Frequency-resonance-enhanced vibrational resonance in bistable systems  

Microsoft Academic Search

The dynamics in an overdamped bistable system subject to the action of two periodic forces (assuming their frequencies are omega and Omega, and amplitudes are A and B, respectively) is studied. For the usual vibrational resonance, the nonmonotonic dependence of signal output of the low frequency omega on the change of B for a fixed Omega, the condition Omega≫omega is

Chenggui Yao; Yan Liu; Meng Zhan

2011-01-01

414

Slow noise processes in superconducting resonators  

NASA Astrophysics Data System (ADS)

Slow noise processes, with characteristic timescales ˜1 s, have been studied in planar superconducting resonators. A frequency-locked loop is employed to track deviations of the resonator center frequency with high precision and bandwidth. Comparative measurements are made in varying microwave drive and temperature, and between bare resonators and those with an additional dielectric layer. All resonators are found to exhibit flicker frequency noise which increases with decreasing microwave drive. We also show that an increase in temperature results in a saturation of flicker noise in resonators with an additional dielectric layer, while bare resonators stop exhibiting flicker noise, instead showing a random frequency walk process.

Burnett, J.; Lindström, T.; Oxborrow, M.; Harada, Y.; Sekine, Y.; Meeson, P.; Tzalenchuk, A. Ya.

2013-04-01

415

Microwave Frequency Discriminator With Sapphire Resonator  

NASA Technical Reports Server (NTRS)

Cooled sapphire resonator provides ultralow phase noise. Apparatus comprises microwave oscillator operating at nominal frequency of about 8.1 GHz, plus frequency-discriminator circuit measuring phase fluctuations of oscillator output. One outstanding feature of frequency discriminator is sapphire resonator serving as phase reference. Sapphire resonator is dielectric ring resonator operating in "whispering-gallery" mode. Functions at room temperature, but for better performance, typically cooled to operating temperature of about 80 K. Similar resonator described in "Sapphire Ring Resonator for Microwave Oscillator" (NPO-18082).

Santiago, David G.; Dick, G. John

1994-01-01

416

SNAKE DEPLORIZING RESONANCE STUDY IN RHIC  

SciTech Connect

Snake depolarizing resonances due to the imperfect cancellation of the accumulated perturbations on the spin precession between snakes were observed at the Relativistic Heavy Ion Collider (RHIC). During the RHIC 2005 and 2006 polarized proton runs, we mapped out the spectrum of odd order snake resonance at Q{sub y} = 7/10. Here, Q, is the beam vertical betatron tune. We also studied the beam polarization after crossing the 7/10th resonance as a function of resonance crossing rate. This paper reports the measured resonance spectrum as well as the results of resonance crossing.

BAI,M.; CAMERON, P.; LUCCIO, A.; HUANG, H.; PITISYN, V.; ET AL.

2007-06-25

417

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

418

Fluorine-19 nuclear magnetic resonance studies of Escherichia coli membranes.  

PubMed Central

Several fluorinated fatty acids of the general structure CH3(CH2)13--mCF2(CH2)m--2COOH are incorporated biosynthetically as unsaturated fatty acid analogues into the phospholipids of Escherichia coli. Under optimum conditions an unsaturated fatty acid autotroph, K1060B5, can be grown so that 50% of the total phospholipid fatty acids are 8,8-difluoromyristate. Conditions are found for which more than 20% of the fatty acids are fluorinated before a decrease in growth rate is observed. We have used 19F nuclear magnetic resonance to examine membranes isolated from E. coli grown under the latter conditions. A comparison is made with spectra of aqueous dispersions of extracted E. coli phospholipids and model multilayer phospholipid membranes. An explanation of the 19F resonance line shape in these membrane systems and the relationship to a molecular order parameter is given. It is apparent that 19F nuclear magnetic resonance is more sensitive to the degree of ordering or fluidity of phospholipids than spin labels or fluorescent probes. For instance, a dramatic effect of membrane protein on lipid fluidity can be seen. Finally, this method can be used to measure the proportion of frozen and fluid lipid in biological membranes at temperatures within the span of the gel-to-lipid phase transition. PMID:345274

Gent, M P; Cottam, P F; Ho, C

1978-01-01

419

Micromachined thin film plate acoustic wave resonators (FPAR): Part II.  

PubMed

Improved performance thin-film plate acoustic wave resonators (FPAR) using the lowest order symmetric Lamb wave (S0) propagating in highly textured AlN membranes have been previously demonstrated for the first time. In this work, an experimental study of the resonators' performance vs. a variety of design parameters is performed. Devices operating in the vicinity of the stopband center exhibiting a Q-value of up to 3000 at a frequency of around 875 MHz are demonstrated. Further, low-loss high-Q micromachined 2-port longitudinally coupled thin-film resonators using the S0 mode are demonstrated for the first time. For the analysis of the proposed structures, the coupling-of-modes (COM) approach is successfully employed. Initially, the COM model is used for the extraction of physical parameters from one-port FPAR measurements. Subsequently, using the COM model, a satisfactory agreement with the proposed experimental frequency characteristics of S0 2-port FPARs has been achieved, and possibilities for further improvements in the performance discussed. Finally, the frequency spectrum of the one-port devices has been studied and the excited plate modes at different frequencies identified and presented with their Q-factors and temperature coefficients of frequency (TCF). PMID:20040407

Yantchev, Ventsislav; Arapan, Lilia; Katardjiev, Ilia

2009-12-01

420

The Study of ? + 14C Cluster States of 18O Through the Resonant Breakup Reaction 12C(18O, 14C?) at E(18O) = 94.5 MeV  

NASA Astrophysics Data System (ADS)

In this work, we study the alpha cluster structure of 18O using resonant particle spectroscopy technique. Resonance breakup reaction of the projectile is studied experimentally to extract the excitation energy spectrum of the 18O nucleus. The observed resonant states in the present work are 15.62, 15.82 (5-), 16.02, 16.22, 16.42, 16.92, 17.22, and 17.82 MeV.

Adhikari, S.; Basu, C.; Behera, B. R.; Ray, S.; Mitra, A. K.; Kumar, Suresh; Chatterjee, A.

421

Extractant composition including crown ether and calixarene extractants  

DOEpatents

An extractant composition comprising a mixed extractant solvent consisting of calix[4] arene-bis-(tert-octylbenzo)-crown-6 ("BOBCalixC6"), 4',4',(5')-di-(t-butyldicyclo-hexano)-18-crown-6 ("DtBu18C6"), and at least one modifier dissolved in a diluent. The DtBu18C6 may be present at from approximately 0.01M to approximately 0.4M, such as at from approximately 0.086 M to approximately 0.108 M. The modifier may be 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol ("Cs-7SB") and may be present at from approximately 0.01M to approximately 0.8M. In one embodiment, the mixed extractant solvent includes approximately 0.15M DtBu18C6, approximately 0.007M BOBCalixC6, and approximately 0.75M Cs-7SB modifier dissolved in an isoparaffinic hydrocarbon diluent. The extractant composition further comprises an aqueous phase. The mixed extractant solvent may be used to remove cesium and strontium from the aqueous phase.

Meikrantz, David H. (Idaho Falls, ID); Todd, Terry A. (Aberdeen, ID); Riddle, Catherine L. (Idaho Falls, ID); Law, Jack D. (Pocalello, ID); Peterman, Dean R. (Idaho Falls, ID); Mincher, Bruce J. (Idaho Falls, ID); McGrath, Christopher A. (Blackfoot, ID); Baker, John D. (Blackfoot, ID)

2009-04-28

422

Turn-By Beam Extraction during Acceleration in a Synchrotron  

NASA Astrophysics Data System (ADS)

A synchrotron to accelerate protons or carbon ions for medical applications is being designed at Brookhaven National Laboratory (BNL). Single beam bunches with maximum beam energy of 1.18 GeV and 400 MeV/u for protons and carbon ions respectively will be extracted from the synchrotron at 15 Hz. For protons, the maximum required energy for irradiating a tumor is ˜206 MeV. A pencil-like proton beam containing ˜5.4×107 p/bunch delivers a therapeutic dose of 2.5 Gy in ˜1.5 minutes to treat a tumor of 1 liter volume. It will take ˜80 minutes with bunches containing 4.5×104 ions/bunch to deliver the same dose of 2.5 Gy with a 400 MeV/u pencil-like carbon beam. This extended treatment time when using carbon ions is not acceptable. In addition, the synchrotron cannot be controlled with a beam bunch containing such a low number of carbon ions. To overcome these two problems of the extended treatment time and the low bunch intensity required for the treatment when carbon ions are used, we have devised a method to “peel” the required 4.5×104 carbon-ions/bunch from the accelerating carbon beam bunch containing ˜108 ions/bunch and deliver them to the tumor on a “turn-by-turn” basis. Unlike other methods of beam extraction from a synchrotron, such as resonance extraction, this method does not allow for any beam losses during the extraction and the carbon beam can be peeled off in less than 15 ms during the acceleration or deceleration cycle of the synchrotron. Thus, this turn-by-turn beam extraction method provides beam with variable energy and precisely controlled beam current during the 30 ms acceleration or deceleration time.

Tsoupas, Nicholaos; Trbojevic, Dejan

2014-02-01

423

INVESTIGATION OF RESONANT OPTOACOUSTIC CELLS  

EPA Science Inventory

A theory describing the optoacoustic signal is presented; dependence on both cell and gas parameters are given and the advantage of operating at a resonant frequency is discussed. Three elliptical cells with major axes 5.8, 12.7, and 15.2 cm (corresponding minor axes 5.5, 11.0; a...

424

Atom localization via resonance fluorescence  

Microsoft Academic Search

We propose a simple scheme of atom localization based on resonance fluorescence from a standing-wave field. The Rabi frequency is position dependent and therefore the spontaneously emitted photon carries the information of the atomic center-of-mass motion. This leads to atom localization even during the flight through the standing-wave field.

Sajid Qamar; Shi-Yao Zhu; M. Suhail Zubairy

2000-01-01

425

N AND RESONANCES I. Introduction  

E-print Network

) G37 i (2300) H39 d (2350) D35 d (2390) F37 e (2400) G39 n (2420) H3 11 (2750) I3 13­ 1­ N AND RESONANCES I. Introduction The excited states of the nucleon have been studied in a large number of formation and production experiments. The conventional (i.e., Breit-Wigner) masses, pole

426

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

427

Model for resonant plasma probe.  

SciTech Connect

This report constructs simple circuit models for a hairpin shaped resonant plasma probe. Effects of the plasma sheath region surrounding the wires making up the probe are determined. Electromagnetic simulations of the probe are compared to the circuit model results. The perturbing effects of the disc cavity in which the probe operates are also found.

Warne, Larry Kevin; Johnson, William Arthur; Hebner, Gregory Albert; Jorgenson, Roy E.; Coats, Rebecca Sue

2007-04-01

428

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

429

Stochastic Resonance and Information Processing  

NASA Astrophysics Data System (ADS)

A dynamical system giving rise to multiple steady states and subjected to noise and a periodic forcing is analyzed from the standpoint of information theory. It is shown that stochastic resonance has a clearcut signature on information entropy, information transfer and other related quantities characterizing information transduction within the system.

Nicolis, C.

2014-12-01

430

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

431

Spin Motion Near Snake Resonances  

SciTech Connect

We give a brief account of on-going work on the loss of polarisation during acceleration close to so-called snake resonances in proton storage rings. We show that within the model studied here the polarisation can be preserved if the rate of acceleration is low enough.

Barber, D. P.; Vogt, M. [Deutsches Elektronen-Synchrotron, DESY, Notkestrasse 85, 22607 Hamburg (Germany)

2007-06-13

432

Research on the selection of wavelet function for the feature extraction of shock fault in the bearing diagnosis  

Microsoft Academic Search

For the rolling bearing diagnosis, how to identify the fault feature effectively is the key issue. Due to the resonance modulation characteristic induced by shock fault of the rolling bearings, the wavelet transform technology can extract the modulation information effectively. On the other hand, as there are no fixed kernel functions in wavelet analysis, the transform results are closely related

Jian-Yu Zhang; Ling-Li Cui; Gui-Yan Yao; Li-Xin Gao

2007-01-01

433

High quality-factor optical resonators  

NASA Astrophysics Data System (ADS)

Various resonators are investigated for microwave photonic applications. Micro-sphere, disk and fiber ring resonators were designed, realized and characterized. Obtained quality factors are as high as Q = 1010.

Henriet, Rémi; Salzenstein, Patrice; Ristic, Davor; Coillet, Aurélien; Mortier, Michel; Rasoloniaina, Alphonse; Saleh, Khaldoun; Cibiel, Gilles; Dumeige, Yannick; Ferrari, Maurizio; Chembo, Yanne K.; Llopis, Olivier; Féron, Patrice

2014-09-01

434

Piezoelectric MEMS resonator characterization and filter design  

E-print Network

This thesis presents modeling and first measurements of a new piezoelectric MEMS resonator developed at Draper Laboratory. In addition, some simple filter designs incorporating the resonator with predicted performance ...

Kang, Joung-Mo, 1978-

2004-01-01

435

14 CFR 29.241 - Ground resonance.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Ground resonance. 29.241 Section 29.241...TRANSPORT CATEGORY ROTORCRAFT Flight Ground and Water Handling Characteristics § 29.241 Ground resonance. The rotorcraft may have...

2010-01-01

436

14 CFR 27.241 - Ground resonance.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 2014-01-01 false Ground resonance. 27.241 Section 27.241...STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Ground and Water Handling Characteristics § 27.241 Ground resonance. The rotorcraft may have...

2014-01-01

437

14 CFR 27.241 - Ground resonance.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Ground resonance. 27.241 Section 27.241...STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Ground and Water Handling Characteristics § 27.241 Ground resonance. The rotorcraft may have...

2013-01-01

438

14 CFR 27.241 - Ground resonance.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Ground resonance. 27.241 Section 27.241...STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Ground and Water Handling Characteristics § 27.241 Ground resonance. The rotorcraft may have...

2012-01-01

439

14 CFR 27.241 - Ground resonance.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Ground resonance. 27.241 Section 27.241...STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Ground and Water Handling Characteristics § 27.241 Ground resonance. The rotorcraft may have...

2010-01-01

440

14 CFR 29.241 - Ground resonance.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Ground resonance. 29.241 Section 29.241...TRANSPORT CATEGORY ROTORCRAFT Flight Ground and Water Handling Characteristics § 29.241 Ground resonance. The rotorcraft may have...

2013-01-01

441

14 CFR 27.241 - Ground resonance.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Ground resonance. 27.241 Section 27.241...STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Ground and Water Handling Characteristics § 27.241 Ground resonance. The rotorcraft may have...

2011-01-01

442

14 CFR 29.241 - Ground resonance.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Ground resonance. 29.241 Section 29.241...TRANSPORT CATEGORY ROTORCRAFT Flight Ground and Water Handling Characteristics § 29.241 Ground resonance. The rotorcraft may have...

2011-01-01

443

14 CFR 29.241 - Ground resonance.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Ground resonance. 29.241 Section 29.241...TRANSPORT CATEGORY ROTORCRAFT Flight Ground and Water Handling Characteristics § 29.241 Ground resonance. The rotorcraft may have...

2012-01-01

444

14 CFR 29.241 - Ground resonance.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 2014-01-01 false Ground resonance. 29.241 Section 29.241...TRANSPORT CATEGORY ROTORCRAFT Flight Ground and Water Handling Characteristics § 29.241 Ground resonance. The rotorcraft may have...

2014-01-01

445

Phobos and Triton at Resonances  

NASA Astrophysics Data System (ADS)

The current routes of Phobos and Triton which are spiralling in towards their host planets can give rise to interesting discussions. In the case of Phobos, some important resonances between the elements of the satellite and the mean motion of the Sun can occur. In this work, considering the precession of Mars' equator and also the variation of the obliquity we show a possible and interesting case of capture in a 2:1 resonance (longitude of Phobos' node and mean motion of the Sun). In this scenario, Phobos' inclination suffers a large variation, increasing rapidly, from 10 to more than 200. This capture, however, is temporary and our calculations show that escape occurs before any other critical inclination is attained. For Triton, under certain hypothesis on the tidal model, we obtained a simplified equation that gives the evolution of its inclination in terms of the semi-major axis (Chyba, Jankowski, Nicholson, 1989). Then it is possible to predict the values of Triton's inclination when some mean motion resonances between Triton and Proteus will occur. An analytical expansion of the classical disturbing function for the retrograde case is obtained in order to better understand the problem. The effects of these retrograde resonances are studied and mainly, for first order resonances they become very important since Proteus' eccentricity undergoes large variations. In many cases the final result is an escaping trajectory. Therefore the onset of this instability can become important for the whole Neptunian inner satellites. This research was funded by FAPESP (98-15867-8, 00-14405-2).

Yokoyama, T.; Nascimento, C.; Mana, M. R.

2001-11-01

446

Stochastic resonance in visual sensitivity.  

PubMed

It is well known from psychophysical studies that stochastic resonance, in its simplest threshold paradigm, can be used as a tool to measure the detection sensitivity to fine details in noise contaminated stimuli. In the present manuscript, we report simulation studies conducted in the similar threshold paradigm of stochastic resonance. We have estimated the contrast sensitivity in detecting noisy sine-wave stimuli, with varying area and spatial frequency, as a function of noise strength. In all the cases, the measured sensitivity attained a peak at intermediate noise strength, which indicate the occurrence of stochastic resonance. The peak sensitivity exhibited a strong dependence on area and spatial frequency of the stimulus. We show that the peak contrast sensitivity varies with spatial frequency in a nonmonotonic fashion and the qualitative nature of the sensitivity variation is in good agreement with human contrast sensitivity function. We also demonstrate that the peak sensitivity first increases and then saturates with increasing area, and this result is in line with the results of psychophysical experiments. Additionally, we also show that critical area, denoting the saturation of contrast sensitivity, decreases with spatial frequency and the associated maximum contrast sensitivity varies with spatial frequency in a manner that is consistent with the results of psychophysical experiments. In all the studies, the sensitivities were elevated via a nonlinear filtering operation called stochastic resonance. Because of this nonlinear effect, it was not guaranteed that the sensitivities, estimated at each frequency, would be in agreement with the corresponding results of psychophysical experiments; on the contrary, close agreements were observed between our results and the findings of psychophysical investigations. These observations indicate the utility of stochastic resonance in human vision and suggest that this paradigm can be useful in psychophysical studies. PMID:25398687

Kundu, Ajanta; Sarkar, Sandip

2014-11-15

447

Dissociation of chloromethanes upon resonant ?* excitation studied by x-ray scattering  

NASA Astrophysics Data System (ADS)

The dissociation process following the Cl K-shell excitation to ?* resonances is studied by high resolution spectroscopy of resonant elastic and inelastic x-ray scattering on CH3Cl, CH2Cl2, CHCl3, and CCl4 molecules. Calculations employing the transition potential and Delta-Kohn-Sham DFT approach are in good agreement with the measured total fluorescence yield and show the presence of a second quasidegenerate group of states with ?* character above the lowest ?* unoccupied molecular orbital for molecules with more than one Cl atom. A bandwidth narrowing and a nonlinear dispersion behavior is extracted from the K? spectral maps for both ?* resonances. The fitted data indicate that the widths of the Franck-Condon distributions for the first and second ?* resonances are comparable for all the molecules under study. In addition, an asymmetric broadening of the emission peaks is observed for resonant elastic x-ray scattering with zero detuning on both ?* resonances. This is attributed to the fast dissociation, transferring about 0.15 of the scattering probability into higher vibrational modes.

Bohinc, R.; Žitnik, M.; Bu?ar, K.; Kav?i?, M.; Journel, L.; Guillemin, R.; Marchenko, T.; Simon, M.; Cao, W.

2013-10-01

448

Dissociation of chloromethanes upon resonant ?{sup *} excitation studied by x-ray scattering  

SciTech Connect

The dissociation process following the Cl K-shell excitation to ?{sup *} resonances is studied by high resolution spectroscopy of resonant elastic and inelastic x-ray scattering on CH{sub 3}Cl, CH{sub 2}Cl{sub 2}, CHCl{sub 3}, and CCl{sub 4} molecules. Calculations employing the transition potential and Delta-Kohn-Sham DFT approach are in good agreement with the measured total fluorescence yield and show the presence of a second quasidegenerate group of states with ?{sup *} character above the lowest ?{sup *} unoccupied molecular orbital for molecules with more than one Cl atom. A bandwidth narrowing and a nonlinear dispersion behavior is extracted from the K? spectral maps for both ?{sup *} resonances. The fitted data indicate that the widths of the Franck-Condon distributions for the first and second ?{sup *} resonances are comparable for all the molecules under study. In addition, an asymmetric broadening of the emission peaks is observed for resonant elastic x-ray scattering with zero detuning on both ?{sup *} resonances. This is attributed to the fast dissociation, transferring about 0.15 of the scattering probability into higher vibrational modes.

Bohinc, R.; Bu?ar, K.; Kav?i?, M. [Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia)] [Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); Žitnik, M. [Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia) [Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); Faculty of Mathematics and Physics, University of Ljubljana, Jadranska ulica 19, SI-1000 Ljubljana (Slovenia); Journel, L.; Guillemin, R.; Marchenko, T.; Simon, M. [UPMC, Université Paris 06, CNRS, UMR 7614, LCPMR, 11 rue Pierre et Marie Curie, 75231, Paris Cedex 05 (France)] [UPMC, Université Paris 06, CNRS, UMR 7614, LCPMR, 11 rue Pierre et Marie Curie, 75231, Paris Cedex 05 (France); Cao, W. [Department of Physics, University of Oulu, P.O. Box 3000, FIN-90014 Oulu (Finland) [Department of Physics, University of Oulu, P.O. Box 3000, FIN-90014 Oulu (Finland); Department of Physics, University of Fribourg, Ch-1700 Fribourg (Switzerland); Department of Chemistry, 110 Science Place, Saskatoon, Saskatchewan S7N 5C9 (Canada)

2013-10-07

449

Sphericity determination using resonant ultrasound spectroscopy  

Microsoft Academic Search

A method is provided for grading production quantities of spherical objects, such as roller balls for bearings. A resonant ultrasound spectrum (RUS) is generated for each spherical object and a set of degenerate sphere-resonance frequencies is identified. From the degenerate sphere-resonance frequencies and known relationships between degenerate sphere-resonance frequencies and Poisson's ratio, a Poisson's ratio can be determined, along with

R. D. Dixon; A. Migliori; W. M. Visscher

1994-01-01

450

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

451

Gaussian-Beam Laser-Resonator Program  

NASA Technical Reports Server (NTRS)

Gaussian Beam Laser Resonator Program models laser resonators by use of Gaussian-beam-propagation techniques. Used to determine radii of beams as functions of position in laser resonators. Algorithm used in program has three major components. First, ray-transfer matrix for laser resonator must be calculated. Next, initial parameters of beam calculated. Finally, propagation of beam through optical elements computed. Written in Microsoft FORTRAN (Version 4.01).

Cross, Patricia L.; Bair, Clayton H.; Barnes, Norman

1989-01-01

452

Resonant Problems for Ordinary Dierential Equations  

E-print Network

Resonant Problems for Ordinary Dierential Equations P. Amster, P. De Nápoli and M.C. Mariani Abstract We review some aspects of the theory of resonant ordinary dierential equations, and present some recent results about higher order resonant dierential equations. 1 Introduction In the last years

De Nápoli, Pablo Luis

453

MICROMACHINED ACOUSTIC RESONATORS FOR MICROJET PROPULSION  

Microsoft Academic Search

The thrust produced by synthetic jets designed for micro jet propulsion is discussed. The proposed propulsion system consists of synthetic wall jets located at the throat of an ejector shroud that are powered by Helmholtz-type acoustic resonators. The theory of acoustic resonators is described and the thrust produced by the resonators calculated. Theoretical results of the exit velocity and thrust

Michael O. Müller; Luis P. Bernal; Robert P. Moran; Peter D. Washabaugh

2000-01-01

454

LC Resonant Circuits Dr. Roger King  

E-print Network

series-resonant LC circuits. Fig. 1(a) shows the classic textbook form of the circuit, including a series and damping resistor are all in series. Fig. 2 displays two parallel-resonant LC circuits. Fig. 2(a or the capacitor voltage v. 1 of 14 #12;The series-resonant configuration arises naturally in a circuit having

King, Roger

455

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

456

VIBRATIONAL RESONANCE IN AN ASYMMETRIC DUFFING OSCILLATOR  

E-print Network

VIBRATIONAL RESONANCE IN AN ASYMMETRIC DUFFING OSCILLATOR S. JEYAKUMARI, V. CHINNATHAMBI Department of the high-frequency forces at which vibrational resonance occurs. Furthermore, we observe that an additional: Vibrational resonance; asymmetric Duffing oscillator; biperiodic force. 1 #12;I. INTRODUCTION The study

Rey Juan Carlos, Universidad

457

Bistable electron magnetic resonance in solids  

Microsoft Academic Search

This paper describes the phenomenon of Bistable Electron Magnetic Resonance, which manifests itself by a resonance line with a distorted shark fin-like shape. This effect requires only a fluctuating hyperfine interaction between electron spins and nuclear spins. It is demonstrated for shallow donors in semiconductors and conduction electrons in light metals. Bistability is an intrinsic property of electron magnetic resonance

Didier Gourier; Laurent Binet; Olivier Guillot-Noël

2004-01-01

458

Embedding optical microfiber coil resonators in Teflon  

Microsoft Academic Search

A method to manufacture optical microfiber coil resonators embedded in Teflon has been demonstrated for what is the first time to the best of our knowledge. The resonator was obtained by wrapping a microfiber on a low refractive index rod and coating it with a Teflon resin. The coating process is investigated and discussed. Resonances in excess of 9 dB,

Fei Xu; Gilberto Brambilla

2007-01-01

459

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

460

Extraction of anthraquinones from roots of Morinda citrifolia by pressurized hot water: Antioxidant activity of extracts  

Microsoft Academic Search

The effectiveness of pressurized hot water extraction (PHWE) of anthraquinones from Morinda citrifolia was evaluated by determining the capability of the extracts to scavenge the free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) in vitro, as compared with the extracts obtained by other conventional extraction methods such as ethanol extraction in stirred vessel, Soxhlet extraction, and ultrasound-assisted extraction (UAE). It was found that PHWE

Boonchai Pongnaravane; Motonobu Goto; Mitsuru Sasaki; Thitiporn Anekpankul; Prasert Pavasant; Artiwan Shotipruk

2006-01-01

461

Three Resonant Ultra-Cold Bosons: Off-Resonance Effects Mattia Jona-Lasinio(1)  

E-print Network

for a description of three-body properties at finite detun- ing, where off-resonant scattering effects comeThree Resonant Ultra-Cold Bosons: Off-Resonance Effects Mattia Jona-Lasinio(1) and Ludovic) We solve a finite range two-channel model for three resonant identical bosons. The model pro- vides

Paris-Sud XI, Université de

462

Ferromagnetic resonance imaging of Co films using magnetic resonance force microscopy  

E-print Network

Ferromagnetic resonance imaging of Co films using magnetic resonance force microscopy B. J. Suh, P is similar to that used in magnetic force microscopy MFM ,4 where only the spin magnetization in the vicinity of microscopic ferromagnetic resonance FMR detected using the magnetic resonance force microscope MRFM

Hammel, P. Chris

463

Extracting Facts with Columbus from C++ Code  

E-print Network

Extracting Facts with Columbus from C++ Code Rudolf Ferenc, Árpád Beszédes and Tibor Gyimóthy Department Fact Extraction with Columbus C++ source code analysis Extracted facts conform to well defined Engineering Department Columbus Framework Fact Extraction Process Project handling Compiler wrapping IDE

Ferenc, Rudolf

464

Forest-Based Translation Rule Extraction  

E-print Network

Forest-Based Translation Rule Extraction EMNLP 2008 talk, Honolulu, Hawaii, October 2008 Haitao Mi #12;Forest-based Translation Rule Extraction Translation Rule Extraction · rule extraction ("syntax") from either or both sides · more informed translation thanks to syn. categories

Plotkin, Joshua B.

465

Double-wavelength Fano resonance and enhanced coupled-resonator-induced transparency in a double-microcavity resonator system.  

PubMed

We present a theoretical study on resonance control in a double-microcavity resonator system coupled to a waveguide with gain in one microresonator and loss in the other. We demonstrate the variation of the output spectra in the waveguide from initial double-wavelength-wide symmetric resonance to double-wavelength sharper asymmetric Fano profiles when gain is introduced in one of the two microresonators, as well as the inversion of the Fano resonance pattern when gain is introduced in the other microresonator. We also investigate the enhanced coupled-resonator-induced-transparency effect in such a system. PMID:16783436

Lu, Ying; Xu, Lijuan; Yu, Yizhong; Wang, Peng; Yao, Jianquan

2006-07-01

466

Accurate extraction of the News  

E-print Network

We propose a new scheme for extracting gravitational radiation from a characteristic numerical simulation of a spacetime. This method is similar in conception to our earlier work but analytical and numerical implementation is different. The scheme is based on direct transformation to the Bondi coordinates and the gravitational waves are extracted by calculating the Bondi news function in Bondi coordinates. The entire calculation is done in a way which will make the implementation easy when we use uniform Bondi angular grid at $\\mathcal I^+$. Using uniform Bondi grid for news calculation has added advantage that we have to solve only ordinary differential equations instead of partial differential equation. For the test problems this new scheme allows us to extract gravitational radiation much more accurately than the previous schemes.

Shrirang S. Deshingkar

2006-09-14

467

Extraction of silicones from soil  

SciTech Connect

Silicone polymer, polydimethylsiloxane (PDMS), was extracted from soil incubated at 100 mg kg[sup [minus]1] for 0,1,3,7,14, and 28 d with mean recovery of 95.4% ([sigma] = 2.1%). From four agricultural soils incubated for one week at 1, 10, and 100 mg kg[sup [minus]1], mean extraction recovery was 95.6% ([sigma] = 3.2%). The method is now being used in [sup 14]C studies on the fate of silicones in the soil environment and will later be used for extraction of silicones from field samples. Silicone polymers have a variety of uses, including lubricants, electrical insulators, and texturizers in personal care products. They can enter the environment through wastewater treatment systems in which they adsorb to the solids, and are then applied to the soil during disposal of the sludge.

Lehmann, R.G. (Dow Corning Corp., Midland, MI (United States). Health and Environmental Sciences)

1993-10-01

468

Shuttle seated extraction feasibility study  

NASA Astrophysics Data System (ADS)

Following the Space Shuttle Challenger accident, serious attention has turned to in-flight escape. Prior to the resumption of flight, a manual bailout system was qualified and installed. For the long term, a seated extraction system to expand the escape envelope is being investigated. This paper describes a 1987 study, conducted jointly by NASA/Johnson Space Center and Langley Research Center, to determine the feasibility of modifying the Space Shuttle Orbiters to incorporate the seated extraction system. Results of the study are positive, indicating retrofit opportunity and high probability of escape for early ascent, late entry, and even for uncontrolled flight such as the Challenger breakup. The system, as envisioned, can extract seven crewmembers within two seconds.

Onagel, Steven R.; Bement, Laurence J.

469

Shuttle seated extraction feasibility study  

NASA Technical Reports Server (NTRS)

Following the Space Shuttle Challenger accident, serious attention has turned to in-flight escape. Prior to the resumption of flight, a manual bailout system was qualified and installed. For the long term, a seated extraction system to expand the escape envelope is being investigated. This paper describes a 1987 study, conducted jointly by NASA/Johnson Space Center and Langley Research Center, to determine the feasibility of modifying the Space Shuttle Orbiters to incorporate the seated extraction system. Results of the study are positive, indicating retrofit opportunity and high probability of escape for early ascent, late entry, and even for uncontrolled flight such as the Challenger breakup. The system, as envisioned, can extract seven crewmembers within two seconds.

Onagel, Steven R.; Bement, Laurence J.

1989-01-01

470

Identification and boundary extraction of blobs in complex imagery.  

PubMed

Automated identification and boundary extraction of blobs in "real world" imagery is a difficult task because the boundaries are so irregular that there is often insufficient a priori information describing these boundaries and traditional methods fail. This paper has proposed a progressive segmentation approach and a boundary estimation method to identify the blobs and to yield an accurate description of its boundary. The multiresolution image processing technique is incorporated into the whole work. This work has been applied to the problem of identifying and extracting the boundaries of major vessels (e.g., the aorta) in Magnetic Resonance (MR) imagery and the results are satisfactory. A Laplacian of Gaussian (LOG) operator is utilized as a spot detector to locate the approximate position of the blob of interest. A subimage centered on this approximate position is extracted to eliminate unwanted portions of the image and facilitate further processing. A histogram pyramid is created for the subimage histogram for automated determination of the threshold in the noisy histogram. A shrink-expand operation is then employed to reduced noise and undesired structures in the subimage. The rough and irregular boundary of the blob of interest obtained by thresholding is reparameterized into polar coordinates to create a Fourier descriptor representation of the boundary. Then, the discrete Fourier transform is applied to the reparameterized 1-D discrete curve to permit appropriate smoothing, as required, in frequency space. Finally, the boundary estimation is completed by taking the inverse Fourier transform to reconstruct the boundary of interest. PMID:2804943

Jiang, T; Merickel, M B

1989-01-01

471

Formation of multi-charged ion beams by focusing effect of mid-electrode on electron cyclotron resonance ion source  

SciTech Connect

We are constructing a tandem type electron cyclotron resonance ion source (ECRIS) and a beam line for extracting ion beams. The ion beam is extracted from the second stage by an accel-decel extraction system with a single-hole and the ion beam current on each electrode is measured. The total ion beam current is measured by a faraday cup downstream the extraction electrodes. We measure these currents as a function of the mid-electrode potential. We also change the gap length between electrodes and perform similar measurement. The behaviors of these currents obtained experimentally against the mid-electrode potential show qualitatively good agreement with a simple theoretical consideration including sheath potential effects. The effect of mid-electrode potential is very useful for decreasing the beam loss for enhancing ion beam current extracted from ECRIS.

Imai, Youta, E-mail: imai@nf.eie.eng.osaka-u.ac.jp; Kimura, Daiju; Kurisu, Yosuke; Nozaki, Dai; Yano, Keisuke; Kumakura, Sho; Sato, Fuminobu; Kato, Yushi; Iida, Toshiyuki [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan)] [Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan)

2014-02-15

472

Spatially coherent surface resonance states derived from magnetic resonances  

NASA Astrophysics Data System (ADS)

A thin metamaterial slab comprising a dielectric spacer sandwiched between a metallic grating and a ground plane is shown to possess spatially coherent surface resonance states that span a large frequency range and can be tuned by structural and material parameters. They give rise to nearly perfect angle-selective absorption and thus exhibit directional thermal emissivity. Direct numerical simulations show that the metamaterial slab supports spatially coherent thermal emission in a wide frequency range that is robust against structural disorder.

Wei, Zeyong; Li, Hongqiang; Cao, Yang; Wu, Chao; Ren, Jinzhi; Hang, Zhihong; Chen, Hong; Zhang, Daozhong; Chan, C. T.

2010-09-01

473

Stochastic resonance in electrical circuits. II. Nonconventional stochastic resonance  

Microsoft Academic Search

For pt.I see ibid., vol.46, no.9, pp.1205-14 (1999). Stochastic resonance (SR), in which a periodic signal in a nonlinear system can be amplified by added noise, is discussed. The application of circuit modeling techniques to the conventional form of SR, which occurs in static bistable potentials, was considered in a companion paper. Here, the investigation of nonconventional forms of SR

Dmitrii G. Luchinsky; Riccardo Mannella; Peter V. E. McClintock; Nigel G. Stocks

1999-01-01

474

Proton Resonance Spectroscopy in SILICON-28 and PHOSPHORUS-30.  

NASA Astrophysics Data System (ADS)

Excitation functions for proton elastic scattering and for proton induced reactions were measured with the KN Van de Graaff and associated high resolution system at TUNL for two odd-mass targets. Excitation functions for ('29)Si(p,p), (p,p(,1)), and (p,p(,2)) were obtained in the range E(,p) = 1.29 to 3.30 MeV, and the ('27)Al(p,p), (p,p(,1)), (p,p(,2)), (p,(alpha)(,0)), and (p(alpha)(,1)) differential cross sections were measured in the range E(,p) = 0.92 to 3.05 MeV. The data were measured at four angles with an overall resolution that varied between 350 - 450 eV, full width at half maximum. The measured excitation functions were analyzed with a multi-level, multi-channel R-matrix formalism. The parameters extracted from the data include the resonance energy, total angular momentum, partial elastic and reaction widths, and channel spin and orbital angular momentum mixing ratios. Resonance parameters were determined for 66 resonances in ('30)P in the range E(,x) = 6.85 to 8.79 MeV, and for 104 resonances in ('28)Si in the range E(,x) = 12.47 to 14.53 MeV. The dependence of the resonance shapes on the channel spin mixing ratio and on the l-mixing ratio was investigated for proton scattering on target nuclei with. (DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI). Seven isobaric analog states were identified in ('30)P and eighteen analog states were identified in ('28)Si. Coulomb energies and proton spectroscopic factors were determined and the analog strengths compared with the parent state (d,p) spectroscopic factors. The proton elastic scattering width of the 6(' -), T = 1, stretched state at E(,x) = 14.36 MeV in ('28)Si was measured. Results of calculations relating the measured width to the strength of this state in intermediate energy inelastic scattering are presented. A precise value of the l-mixing ratio was determined for the 2('+) resonance at E(,p) = 1.365 MeV from a measurement of the ('27)Al(p,(alpha)(,0)) reaction. This measurement is relevant to a previous test of time reversal invariance.

Nelson, Ronald Owen

475

Reliability test of an electron cyclotron resonance ion source for accelerator driven sub-critical system.  

PubMed

The reliability test of an electron cyclotron resonance ion source developed for accelerator driven sub-critical system is carried out in China Institute of Atomic Energy. A unique technique to improve the reliability is adopted. The source is operated for more than 200 h at 75 keV, 100 mA extracted hydrogen current, while 2 beam trips are recorded in the period, and uninterrupted operation time is about 150 h. The experimental result is described. PMID:22380168

Cui, B; Tang, B; Ma, R; Huang, Q; Ma, Y; Chen, L; Jiang, W

2012-02-01

476

Reliability test of an electron cyclotron resonance ion source for accelerator driven sub-critical system  

SciTech Connect

The reliability test of an electron cyclotron resonance ion source developed for accelerator driven sub-critical system is carried out in China Institute of Atomic Energy. A unique technique to improve the reliability is adopted. The source is operated for more than 200 h at 75 keV, 100 mA extracted hydrogen current, while 2 beam trips are recorded in the period, and uninterrupted operation time is about 150 h. The experimental result is described.

Cui, B.; Tang, B.; Ma, R.; Huang, Q.; Ma, Y.; Chen, L.; Jiang, W. [China Institute of Atomic Energy, P. O. Box 275(27), Beijing 102413 (China)

2012-02-15

477

Dynamical Coupled-Channel Model of Meson Production Reactions in the Nucleon Resonance Region  

SciTech Connect

A dynamical coupled-channel model is presented for investigating the nucleon resonances (N*) in the meson production reactions induced by pions and photons. Our objective is to extract the N* parameters and to investigate the meson production reaction mechanisms for mapping out the quark-gluon substructure of N* from the data. The model is based on an energy-independent Hamiltonian which is derived from a set of Lagrangians by using a unitary transformation method.

T.-S. H. Lee; A. Matsuyama; T. Sato

2006-11-15

478

Fine structure of the isoscalar giant quadrupole resonance in 40Ca due to Landau damping?  

Microsoft Academic Search

The fragmentation of the Isoscalar Giant Quadrupole Resonance (ISGQR) in 40Ca has been investigated in high energy-resolution experiments using proton inelastic scattering at Ep=200 MeV. Fine structure is observed in the region of the ISGQR and its characteristic energy scales are extracted from the experimental data by means of a wavelet analysis. The experimental scales are well described by Random

I. Usman; Z. Buthelezi; J. Carter; G. R. J. Cooper; R. W. Fearick; S. V. Förtsch; H. Fujita; Y. Fujita; Y. Kalmykov; P. von Neumann-Cosel; R. Neveling; P. Papakonstantinou; A. Richter; R. Roth; A. Shevchenko; E. Sideras-Haddad; F. D. Smit

2011-01-01

479

Metabolism of Lactate in Cultured GABAergic Neurons Studied by 13C Nuclear Magnetic Resonance Spectroscopy  

Microsoft Academic Search

Primary cultures of mouse cerebral cortical neurons (GABAergic) were incubated for 4 hours in media without glucose containing 1.0 mmol\\/L [U-13C]lactate in the absence or presence of 0.5 mmol\\/L glutamine. Redissolved, lyophilized cell extracts were analyzed by 13C nuclear magnetic resonance spectroscopy to investigate neuronal metabolism of lactate and by HPLC for determination of the total amounts of glutamate (Glu),

Helle S. Waagepetersen; Inger J. Bakken; Orla M. Larsson; Ursala Sonnewald; Arne Schousboe

1998-01-01

480

Detection of the inhibitory neurotransmitter GABA in macrophages by magnetic resonance spectroscopy  

Microsoft Academic Search

Macrophages are key components of the inflammatory response to tissue injury, but their activities can exacerbate neuropathology. High-resolution magnetic resonance spectroscopy was used to identify metabolite levels in perchloric acid extracts of cultured cells of the RAW 264.7 murine macrophage line under resting and lipo- polysaccharide-activated conditions. Over 25 me- tabolites were identified including -aminobutyric acid (GABA), an inhibitory neurotransmitter

D. J. Stuckey; D. C. Anthony; J. P. Lowe; J. Miller; W. M. Palm; V. H. Perry; A. M. Blamire; N. R. Sibson

2005-01-01

481

Finite frequency noise for Laughlin state investigated by a resonant circuit  

NASA Astrophysics Data System (ADS)

We study the finite frequency (F.F.) noise properties of edge states in the Laughlin state. We investigate the model of a resonant detector coupled to a quantum point contact in the weak-backscattering limit. In particular we discuss the impact of possible renormalization of the Luttinger exponent, due to environmental effects, on the measured quantities and we propose a simple way to extract such non-universal parameters from noise measurements.

Carrega, M.; Ferraro, D.; Braggio, A.; Sassetti, M.

2014-12-01

482

Noise in nonlinear nanoelectromechanical resonators  

NASA Astrophysics Data System (ADS)

Nano-Electro-Mechanical Systems (NEMS), due to their nanometer scale size, possess a number of desirable attributes: high sensitivity to applied forces, fast response times, high resonance frequencies and low power consumption. However, ultra small size and low power handling result in unwanted consequences: smaller signal size and higher dissipation, making the NEMS devices more susceptible to external and intrinsic noise. The simplest version of a NEMS, a suspended nanomechanical structure with two distinct excitation states, can be used as an archetypal two state system to study a plethora of fundamental phenomena such as Duffing nonlinearity, stochastic resonance, and macroscopic quantum tunneling at low temperatures. From a technical perspective, there are numerous applications such nanomechanical memory elements, microwave switches and nanomechanical computation. The control and manipulation of the mechanical response of these two state systems can be realized by exploiting a (seemingly) counterintuitive physical phenomenon, Stochastic Resonance: in a noisy nonlinear mechanical system, the presence of noise can enhance the system response to an external stimulus. This Thesis is mainly dedicated to study possible applications of Stochastic Resonance in two-state nanomechanical systems. First, on chip signal amplification by 1/falpha is observed. The effectiveness of the noise assisted amplification is observed to decrease with increasing a. Experimental evidence shows an increase in asymmetry between the two states with increasing noise color. Considering the prevalence of 1/f alpha noise in the materials in integrated circuits, the signal enhancement demonstrated here, suggests beneficial use of the otherwise detrimental noise. Finally, a nanomechanical device, operating as a reprogrammable logic gate, and performing fundamental logic functions such as AND/OR and NAND/NOR is presented. The logic function can be programmed (from AND to OR) dynamically, by adjusting the resonator's operating parameters. The device can access one of two stable steady states, according to a specific logic function; this operation is mediated by the noise floor, which can be directly adjusted, or dynamically "tuned" via an adjustment of the underlying nonlinearity of the resonator. The demonstration of this reprogrammable nanomechanical logic gate affords a path to the practical realization of a new generation of mechanical computer.

Guerra Vidal, Diego N.

483

Solvent extraction: the coordination chemistry behind extractive metallurgy.  

PubMed

The modes of action of the commercial solvent extractants used in extractive hydrometallurgy are classified according to whether the recovery process involves the transport of metal cations, M(n+), metalate anions, MXx(n-), or metal salts, MXx into a water-immiscible solvent. Well-established principles of coordination chemistry provide an explanation for the remarkable strengths and selectivities shown by most of these extractants. Reagents which achieve high selectivity when transporting metal cations or metal salts into a water-immiscible solvent usually operate in the inner coordination sphere of the metal and provide donor atom types or dispositions which favour the formation of particularly stable neutral complexes that have high solubility in the hydrocarbons commonly used in recovery processes. In the extraction of metalates, the structures of the neutral assemblies formed in the water-immiscible phase are usually not well defined and the cationic reagents can be assumed to operate in the outer coordination spheres. The formation of secondary bonds in the outer sphere using, for example, electrostatic or H-bonding interactions are favoured by the low polarity of the water-immiscible solvents. PMID:24088789

Wilson, A Matthew; Bailey, Phillip J; Tasker, Peter A; Turkington, Jennifer R; Grant, Richard A; Love, Jason B

2014-01-01

484

Extraction of many-body configurations from nonlinear absorption in semiconductor quantum wells.  

PubMed

Detailed electronic many-body configurations are extracted from quantitatively measured time-resolved nonlinear absorption spectra of resonantly excited GaAs quantum wells. The microscopic theory assigns the observed spectral changes to a unique mixture of electron-hole plasma, exciton, and polarization effects. Strong transient gain is observed only under cocircular pump-probe conditions and is attributed to the transfer of pump-induced coherences to the probe. PMID:20867334

Smith, R P; Wahlstrand, J K; Funk, A C; Mirin, R P; Cundiff, S T; Steiner, J T; Schafer, M; Kira, M; Koch, S W

2010-06-18

485

[Antioxidant properties of plant extracts].  

PubMed

Investigation of antioxidant properties of some plants was carried out. A group of plants exhibited antimicrobial activity was studied in detail. Efficiency of plants as antioxidants was tested by the influence of their extracts on the yield of photochemiluminescence of Gly-Trp solutions. Antioxidant properties were examined under conditions when their own absorption was minimized. Riboflavin as additional sensitizer was used in this experiment for superoxide generation. The antioxidant effect was evaluated with regard to single dose of plant extracts and their concentration in human organism. The effect decreases in the following consequence: Hypericum perforatum > Potentilla erectra > Ledum palustre > Plantago major > Salvia officinalis > Chamomilla recutita > Arctostaphylos uva. PMID:9591094

Bol'shakova, I V; Lozovskaia, E L; Sapezhinski?, I I

1998-01-01

486

Catastrophic extraction of anomalous events  

NASA Astrophysics Data System (ADS)

In this paper we discuss extraction of anomalous events based on the theory of catastrophes, a mathematical theory of continuous geometrical manifolds with discrete singularities called catastrophes. Intelligence exploitation syst