DEFF Research Database (Denmark)
an impetus or drive to that account: change, innovation, rupture, or discontinuity. Resonances: Historical Essays on Continuity and Change explores the historiographical question of the modes of interrelation between these motifs in historical narratives. The essays in the collection attempt to realize...... theoretical consciousness through historical narrative ‘in practice’, by discussing selected historical topics from Western cultural history, within the disciplines of history, literature, visual arts, musicology, archaeology, philosophy, and theology. The title Resonances indicates the overall perspective...
DEFF Research Database (Denmark)
2014-01-01
The present invention relates to a method for detecting photo-thermal absorbance of a material utilising a mechanically temperature sensitive resonator (20) and a sample being arrange in thermal communication with the temperature sensitive resonator. The present invention further relates to an ap......The present invention relates to a method for detecting photo-thermal absorbance of a material utilising a mechanically temperature sensitive resonator (20) and a sample being arrange in thermal communication with the temperature sensitive resonator. The present invention further relates...... to an apparatus for detecting photo-thermal absorbance of a sample....
Rajasekar, Shanmuganathan
2016-01-01
This introductory text presents the basic aspects and most important features of various types of resonances and anti-resonances in dynamical systems. In particular, for each resonance, it covers the theoretical concepts, illustrates them with case studies, and reviews the available information on mechanisms, characterization, numerical simulations, experimental realizations, possible quantum analogues, applications and significant advances made over the years. Resonances are one of the most fundamental phenomena exhibited by nonlinear systems and refer to specific realizations of maximum response of a system due to the ability of that system to store and transfer energy received from an external forcing source. Resonances are of particular importance in physical, engineering and biological systems - they can prove to be advantageous in many applications, while leading to instability and even disasters in others. The book is self-contained, providing the details of mathematical derivations and techniques invo...
Esposito, A.; Pilloni, A.; Polosa, A. D.
2017-01-01
Multiquark resonances are undoubtedly experimentally observed. The number of states and the amount of details on their properties have been growing over the years. It is very recent the discovery of two pentaquarks and the confirmation of four tetraquarks, two of which had not been observed before. We mainly review the theoretical understanding of this sector of particle physics phenomenology and present some considerations attempting a coherent description of the so called X and Z resonances. The prominent problems plaguing theoretical models, like the absence of selection rules limiting the number of states predicted, motivate new directions in model building. Data are reviewed going through all of the observed resonances with particular attention to their common features and the purpose of providing a starting point to further research.
Esposito, A.; Polosa, A.D.
2016-01-01
Multiquark resonances are undoubtedly experimentally observed. The number of states and the amount of details on their properties has been growing over the years. It is very recent the discovery of two pentaquarks and the confirmation of four tetraquarks, two of which had not been observed before. We mainly review the theoretical understanding of this sector of particle physics phenomenology and present some considerations attempting a coherent description of the so called X and Z resonances. The prominent problems plaguing theoretical models, like the absence of selection rules limiting the number of states predicted, motivate new directions in model building. Data are reviewed going through all of the observed resonances with particular attention to their common features and the purpose of providing a starting point to further research.
DEFF Research Database (Denmark)
Hjelholt, Morten; Jensen, Tina Blegind
2015-01-01
IT projects are often complex arrangements of technological components, social actions, and organizational transformation that are difficult to manage in practice. This paper takes an analytical discourse perspective to explore the process of legitimizing IT projects. We introduce the concept...... of resonating statements to highlight how central actors navigate in various discourses over time. Particularly, the statements and actions of an IT project manager are portrayed to show how individuals can legitimize actions by connecting statements to historically produced discourses. The case study...... of an IT project in a Danish local government spans a two-year time period and demonstrates a double-loop legitimization process. First, resonating statements are produced to localize a national IT initiative to support the specificity of a local government discourse. Second, the resonating statements are used...
Oset, E; Sun, Bao Xi; Vacas, M J Vicente; Ramos, A; Gonzalez, P; Vijande, J; Torres, A Martinez; Khemchandani, K
2009-01-01
In this talk I show recent results on how many excited baryon resonances appear as systems of one meson and one baryon, or two mesons and one baryon, with the mesons being either pseudoscalar or vectors. Connection with experiment is made including a discussion on old predictions and recent results for the photoproduction of the $\\Lambda(1405)$ resonance, as well as the prediction of one $1/2^+$ baryon state around 1920 MeV which might have been seen in the $\\gamma p \\to K^+ \\Lambda$ reaction.
Energy Technology Data Exchange (ETDEWEB)
Oset, E. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Sarkar, S. [Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata 700064 (India); Sun Baoxi [Institute of Theoretical Physics, College of Applied Sciences, Beijing University of Technology, Beijing 100124 (China); Vicente Vacas, M.J. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Ramos, A. [Departament d' Estructura i Constituents de la Materia and Institut de Ciencies del Cosmos, Universitat de Barcelona, 08028 Barcelona (Spain); Gonzalez, P. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Vijande, J. [Departamento de Fisica Atomica Molecular y Nuclear and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Martinez Torres, A. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Aptdo. 22085, 46071 Valencia (Spain); Khemchandani, K. [Centro de Fisica Computacional, Departamento de Fisica, Universidade de Coimbra, P-3004-516 Coimbra (Portugal)
2010-04-01
In this talk I show recent results on how many excited baryon resonances appear as systems of one meson and one baryon, or two mesons and one baryon, with the mesons being either pseudoscalar or vectors. Connection with experiment is made including a discussion on old predictions and recent results for the photoproduction of the {lambda}(1405) resonance, as well as the prediction of one 1/2{sup +} baryon state around 1920 MeV which might have been seen in the {gamma}p{yields}K{sup +}{lambda} reaction.
DEFF Research Database (Denmark)
Brooks, Anthony Lewis
2013-01-01
sessions are achieved via adaptive action-analyzed activities. These interactive virtual environments are designed to empower patients’ creative and/or playful expressions via digital feedback stimuli. Unconscious self- pushing of limits result from innate distractive mechanisms offered by the alternative...... the unencumbered motion-to-computer-generated activities - ‘Music Making’, ‘Painting’, ‘Robotic’ and ‘Video Game’ control. A focus of this position paper is to highlight how Aesthetic Resonance, in this context, relates to the growing body of research on Neuroaesthetics to evolve Neuroaesthetic Resonance....
Leavey, Sean; Rae, Katherine; Murray, Adam; Courtial, Johannes
2012-09-01
Autostereograms, or "Magic Eye" pictures, are repeating patterns designed to give the illusion of depth. Here we discuss optical resonators that create light patterns which, when viewed from a suitable position by a monocular observer, are autostereograms of the three-dimensional shape of one of the mirror surfaces.
Experiments with Helmholtz Resonators.
Greenslade, Thomas B., Jr.
1996-01-01
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)
MRI (Magnetic Resonance Imaging)
... and Procedures Medical Imaging MRI (Magnetic Resonance Imaging) MRI (Magnetic Resonance Imaging) Share Tweet Linkedin Pin it More sharing options ... usually given through an IV in the arm. MRI Research Programs at FDA Magnetic Resonance Imaging (MRI) ...
Regenerative feedback resonant circuit
Jones, A. Mark; Kelly, James F.; McCloy, John S.; McMakin, Douglas L.
2014-09-02
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.
Resonance and Neck Length for a Spherical Resonator
Directory of Open Access Journals (Sweden)
Emily Corning
2011-06-01
Full Text Available The relationship between the neck length of a spherical resonator and its period of fundamental resonance was investigated. This was done by measuring the frequency of fundamental resonance of the resonator at 6 different neck lengths. It was found that its resonance resembled Helmholtz resonance but was not that of ideal Helmholtz resonance.
Shcheglov, Kirill V. (Inventor); Challoner, A. Dorian (Inventor); Hayworth, Ken J. (Inventor); Wiberg, Dean V. (Inventor); Yee, Karl Y. (Inventor)
2008-01-01
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.
Zielinski, M.L.; van Lenthe, J.H.
2008-01-01
The resonating block localize wave function (RBLW) method is introduced, a resonating modification of the block localized wave functions introduced by Mo et al. [Mo, Y.; Peyerimhoff, S. D. J. Chem. Phys. 1998, 109, 1687].This approach allows the evaluation of resonance energies following Pauling’s r
Controlling Parametric Resonance
DEFF Research Database (Denmark)
Galeazzi, Roberto; Pettersen, Kristin Ytterstad
2012-01-01
Parametric resonance is a resonant phenomenon which takes place in systems characterized by periodic variations of some parameters. While seen as a threatening condition, whose onset can drive a system into instability, this chapter advocates that parametric resonance may become an advantage if t...
Ovenized microelectromechanical system (MEMS) resonator
Olsson, Roy H; Wojciechowski, Kenneth; Kim, Bongsang
2014-03-11
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.
Magnetic resonance energy and topological resonance energy.
Aihara, Jun-Ichi
2016-04-28
Ring-current diamagnetism of a polycyclic π-system is closely associated with thermodynamic stability due to the individual circuits. Magnetic resonance energy (MRE), derived from the ring-current diamagnetic susceptibility, was explored in conjunction with graph-theoretically defined topological resonance energy (TRE). For many aromatic molecules, MRE is highly correlative with TRE with a correlation coefficient of 0.996. For all π-systems studied, MRE has the same sign as TRE. The only trouble with MRE may be that some antiaromatic and non-alternant species exhibit unusually large MRE-to-TRE ratios. This kind of difficulty can in principle be overcome by prior geometry-optimisation or by changing spin multiplicity. Apart from the semi-empirical resonance-theory resonance energy, MRE is considered as the first aromatic stabilisation energy (ASE) defined without referring to any hypothetical polyene reference.
Weinstein, Dana; Bhave, Sunil A
2010-04-14
This paper introduces the resonant body transistor (RBT), a silicon-based dielectrically transduced nanoelectromechanical (NEM) resonator embedding a sense transistor directly into the resonator body. Combining the benefits of FET sensing with the frequency scaling capabilities and high quality factors (Q) of internal dielectrically transduced bar resonators, the resonant body transistor achieves >10 GHz frequencies and can be integrated into a standard CMOS process for on-chip clock generation, high-Q microwave circuits, fundamental quantum-state preparation and observation, and high-sensitivity measurements. An 11.7 GHz bulk-mode RBT is demonstrated with a quality factor Q of 1830, marking the highest frequency acoustic resonance measured to date on a silicon wafer.
Dynamically generated resonances
Oset, E; Sarkar, S; Sun, Bao Xi; Vacas, M J Vicente; González, P; Vijande, J; Jido, D; Sekihara, T; Torres, A Martinez; Khemchandani, K
2009-01-01
In this talk I report on recent work related to the dynamical generation of baryonic resonances, some made up from pseudoscalar meson-baryon, others from vector meson-baryon and a third type from two meson-one baryon systems. We can establish a correspondence with known baryonic resonances, reinforcing conclusions previously drawn and bringing new light on the nature of some baryonic resonances of higher mass.
Electron paramagnetic resonance
Al'tshuler, S A
2013-01-01
Electron Paramagnetic Resonance is a comprehensive text on the field of electron paramagnetic resonance, covering both the theoretical background and the results of experiment. This book is composed of eight chapters that cover theoretical materials and experimental data on ionic crystals, since these are the materials that have been most extensively studied by the methods of paramagnetic resonance. The opening chapters provide an introduction to the basic principles of electron paramagnetic resonance and the methods of its measurement. The next chapters are devoted to the theory of spectra an
Split ring resonator resonance assisted terahertz antennas
Galal, Hossam; Vitiello, Miriam S
2016-01-01
We report on the computational development of novel architectures of low impedance broadband antennas, for efficient detection of Terahertz (THz) frequency beams. The conceived Split Ring Resonator Resonance Assisted (SRR RA) antennas are based on both a capacitive and inductive scheme, exploiting a 200 Ohm and 400 Ohm impedance, respectively. Moreover, the impedance is tunable by varying the coupling parameters in the exploited geometry, allowing for better matching with the detector circuit for maximum power extraction. Our simulation results have been obtained by assuming a 1.5 THz operation frequency.
Resonance and Fractal Geometry
Broer, Henk W.
2012-01-01
The phenomenon of resonance will be dealt with from the viewpoint of dynamical systems depending on parameters and their bifurcations. Resonance phenomena are associated to open subsets in the parameter space, while their complement corresponds to quasi-periodicity and chaos. The latter phenomena oc
Fundamentals of nanomechanical resonators
Schmid, Silvan; Roukes, Michael Lee
2016-01-01
This authoritative book introduces and summarizes the latest models and skills required to design and optimize nanomechanical resonators, taking a top-down approach that uses macroscopic formulas to model the devices. The authors cover the electrical and mechanical aspects of nano electromechanical system (NEMS) devices. The introduced mechanical models are also key to the understanding and optimization of nanomechanical resonators used e.g. in optomechanics. Five comprehensive chapters address: The eigenmodes derived for the most common continuum mechanical structures used as nanomechanical resonators; The main sources of energy loss in nanomechanical resonators; The responsiveness of micro and nanomechanical resonators to mass, forces, and temperature; The most common underlying physical transduction mechanisms; The measurement basics, including amplitude and frequency noise. The applied approach found in this book is appropriate for engineering students and researchers working with micro and nanomechanical...
Monolithic MACS micro resonators
Lehmann-Horn, J. A.; Jacquinot, J.-F.; Ginefri, J. C.; Bonhomme, C.; Sakellariou, D.
2016-10-01
Magic Angle Coil Spinning (MACS) aids improving the intrinsically low NMR sensitivity of heterogeneous microscopic samples. We report on the design and testing of a new type of monolithic 2D MACS resonators to overcome known limitations of conventional micro coils. The resonators' conductors were printed on dielectric substrate and tuned without utilizing lumped element capacitors. Self-resonance conditions have been computed by a hybrid FEM-MoM technique. Preliminary results reported here indicate robust mechanical stability, reduced eddy currents heating and negligible susceptibility effects. The gain in B1 /√{ P } is in agreement with the NMR sensitivity enhancement according to the principle of reciprocity. A sensitivity enhancement larger than 3 has been achieved in a monolithic micro resonator inside a standard 4 mm rotor at 500 MHz. These 2D resonators could offer higher performance micro-detection and ease of use of heterogeneous microscopic substances such as biomedical samples, microscopic specimens and thin film materials.
Neutrino Production of Resonances
Paschos, E A; Yu, J Y; Paschos, Emmanuel A.; Sakuda, Makoto; Yu, Ji--Young
2004-01-01
We take a fresh look at the analysis of resonance production by neutrinos. We consider three resonances $P_{33}, P_{11}$ and $S_{11}$ with a detailed discussion of their form factors. The article presents results for free proton and neutron targets and discusses the corrections which appear on nuclear targets. The Pauli suppression factor is derived in the Fermi gas model and shown to apply to resonance production. The importance of the various resonances is demonstrated with numerical calculations. The $\\Delta$-resonance is described by two formfactors and its differential cross sections are compared with experimental data. The article is self-contained and could be helpful to readers who wish to reproduce and use these cross sections.
Resonance Radiation and Excited Atoms
Mitchell, Allan C. G.; Zemansky, Mark W.
2009-06-01
1. Introduction; 2. Physical and chemical effects connected with resonance radiation; 3. Absorption lines and measurements of the lifetime of the resonance state; 4. Collision processes involving excited atoms; 5. The polarization of resonance radiation; Appendix; Index.
Advances in magnetic resonance 10
Waugh, John S
2013-01-01
Advances in Magnetic Resonance, Volume 10, presents a variety of contributions to the theory and practice of magnetic resonance. The book contains three chapters that examine superoperators in magnetic resonance; ultrasonically modulated paramagnetic resonance; and the utility of electron paramagnetic resonance (EPR) and electron-nuclear double-resonance (ENDOR) techniques for studying low-frequency modes of atomic fluctuations and their significance for understanding the mechanism of structural phase transitions in solids.
Tunable multiwalled nanotube resonator
Zettl, Alex K.; Jensen, Kenneth J.; Girit, Caglar; Mickelson, William E.; Grossman, Jeffrey C.
2011-03-29
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.
Spin Resonance Strength Calculations
Courant, E. D.
2009-08-01
In calculating the strengths of depolarizing resonances it may be convenient to reformulate the equations of spin motion in a coordinate system based on the actual trajectory of the particle, as introduced by Kondratenko, rather than the conventional one based on a reference orbit. It is shown that resonance strengths calculated by the conventional and the revised formalisms are identical. Resonances induced by radiofrequency dipoles or solenoids are also treated; with rf dipoles it is essential to consider not only the direct effect of the dipole but also the contribution from oscillations induced by it.
Spin resonance strength calculations
Energy Technology Data Exchange (ETDEWEB)
Courant,E.D.
2008-10-06
In calculating the strengths of depolarizing resonances it may be convenient to reformulate the equations of spin motion in a coordinate system based on the actual trajectory of the particle, as introduced by Kondratenko, rather than the conventional one based on a reference orbit. It is shown that resonance strengths calculated by the conventional and the revised formalisms are identical. Resonances induced by radiofrequency dipoles or solenoids are also treated; with rf dipoles it is essential to consider not only the direct effect of the dipole but also the contribution from oscillations induced by it.
Kazimierczuk, Marian K
2012-01-01
This book is devoted to resonant energy conversion in power electronics. It is a practical, systematic guide to the analysis and design of various dc-dc resonant inverters, high-frequency rectifiers, and dc-dc resonant converters that are building blocks of many of today's high-frequency energy processors. Designed to function as both a superior senior-to-graduate level textbook for electrical engineering courses and a valuable professional reference for practicing engineers, it provides students and engineers with a solid grasp of existing high-frequency technology, while acquainting them wit
Magnetic Resonance Force Microscopy System
Federal Laboratory Consortium — The Magnetic Resonance Force Microscopy (MRFM) system, developed by ARL, is the world's most sensitive nuclear magnetic resonance (NMR) spectroscopic analysis tool,...
Resonant Diphoton Phenomenology Simplified
Panico, Giuliano; Wulzer, Andrea
2016-01-01
A framework is proposed to describe resonant diphoton phenomenology at hadron colliders in full generality. It can be employed for a comprehensive model-independent interpretation of the experimental data. Within the general framework, few benchmark scenarios are defined as representative of the various phenomenological options and/or of motivated new physics scenarios. Their usage is illustrated by performing a characterization of the 750 GeV excess, based on a recast of available experimental results. We also perform an assessment of which properties of the resonance could be inferred, after discovery, by a careful experimental study of the diphoton distributions. These include the spin J of the new particle and its dominant production mode. Partial information on its CP-parity can also be obtained, but only for J >= 2. The complete determination of the resonance CP properties requires studying the pattern of the initial state radiation that accompanies the resonance production.
Energy Technology Data Exchange (ETDEWEB)
Lutz, Matthias F. M.; Lange, Jens Sören; Pennington, Michael; Bettoni, Diego; Brambilla, Nora; Crede, Volker; Eidelman, Simon; Gillitzer, Albrecht; Gradl, Wolfgang; Lang, Christian B.; Metag, Volker; Nakano, Takashi; Nieves, Juan; Neubert, Sebastian; Oka, Makoto; Olsen, Stephen L.; Pappagallo, Marco; Paul, Stephan; Pelizäus, Marc; Pilloni, Alessandro; Prencipe, Elisabetta; Ritman, Jim; Ryan, Sinead; Thoma, Ulrike; Uwer, Ulrich; Weise, Wolfram
2016-04-01
We report on the EMMI Rapid Reaction Task Force meeting 'Resonances in QCD', which took place at GSI October 12-14, 2015 (Fig.~1). A group of 26 people met to discuss the physics of resonances in QCD. The aim of the meeting was defined by the following three key questions; what is needed to understand the physics of resonances in QCD?; where does QCD lead us to expect resonances with exotic quantum numbers?; and what experimental efforts are required to arrive at a coherent picture? For light mesons and baryons only those with up, down and strange quark content were considered. For heavy-light and heavy-heavy meson systems, those with charm quarks were the focus.This document summarizes the discussions by the participants, which in turn led to the coherent conclusions we present here.
Resonant Thermoelectric Nanophotonics
Mauser, Kelly W; Kim, Seyoon; Fleischman, Dagny; Atwater, Harry A
2016-01-01
Photodetectors are typically based on photocurrent generation from electron-hole pairs in semiconductor structures and on bolometry for wavelengths that are below bandgap absorption. In both cases, resonant plasmonic and nanophotonic structures have been successfully used to enhance performance. In this work, we demonstrate subwavelength thermoelectric nanostructures designed for resonant spectrally selective absorption, which creates large enough localized temperature gradients to generate easily measureable thermoelectric voltages. We show that such structures are tunable and are capable of highly wavelength specific detection, with an input power responsivity of up to 119 V/W (referenced to incident illumination), and response times of nearly 3 kHz, by combining resonant absorption and thermoelectric junctions within a single structure, yielding a bandgap-independent photodetection mechanism. We report results for both resonant nanophotonic bismuth telluride-antimony telluride structures and chromel-alumel...
Markert, Christina
2007-01-01
Hadronic resonances with short life times and strong coupling to the dense medium may exhibit mass shifts and width broadening as signatures of chiral symmetry restoration at the phase transition between hadronic and partonic matter. Resonances with different lifetimes are also used to extract information about the time evolution and temperature of the expanding hadronic medium. In order to collect information about the early stage (at the phase transition) of a heavy-ion collision, resonances and decay particles which are unaffected by the hadronic medium have to be used. We explore a possible new technique to extract signals from the early stage through the selection of resonances from jets. A first attempt of this analysis, using the reconstructed $\\phi$(1020) from 200 GeV Au+Au collisions in STAR, is presented.
Butler, Stephen C
2012-06-01
A detailed analysis is presented of two novel multiple-resonant transducers which produce a wider transmit response than that of a conventional Tonpilz-type transducer. These multi-resonant transducers are Tonpilz-type longitudinal vibrators that produce three coupled resonances and are referred to as triple-resonant transducers (TRTs). One of these designs is a mechanical series arrangement of a tail mass, piezoelectric ceramic stack, central mass, compliant spring, second central mass, second compliant spring, and a piston-radiating head mass. The other TRT design is a mechanical series arrangement of a tail mass, piezoelectric ceramic stack, central mass, compliant spring, and head mass with a quarter-wave matching layer of poly(methyl methacrylate) on the head mass. Several prototype transducer element designs were fabricated that demonstrated proof-of-concept.
Directory of Open Access Journals (Sweden)
Robert H. Morris
2014-11-01
Full Text Available Magnetic Resonance finds countless applications, from spectroscopy to imaging, routinely in almost all research and medical institutions across the globe. It is also becoming more frequently used for specific applications in which the whole instrument and system is designed for a dedicated application. With beginnings in borehole logging for the petro-chemical industry Magnetic Resonance sensors have been applied to fields as varied as online process monitoring for food manufacture and medical point of care diagnostics. This great diversity is seeing exciting developments in magnetic resonance sensing technology published in application specific journals where they are often not seen by the wider sensor community. It is clear that there is enormous interest in magnetic resonance sensors which represents a significant growth area. The aim of this special edition of Sensors was to address the wide distribution of relevant articles by providing a forum to disseminate cutting edge research in this field in a single open source publication.[...
Lutz, Matthias F. M.; Lange, Jens Sören; Pennington, Michael; Bettoni, Diego; Brambilla, Nora; Crede, Volker; Eidelman, Simon; Gillitzer, Albrecht; Gradl, Wolfgang; Lang, Christian B.; Metag, Volker; Nakano, Takashi; Nieves, Juan; Neubert, Sebastian; Oka, Makoto; Olsen, Stephen L.; Pappagallo, Marco; Paul, Stephan; Pelizäus, Marc; Pilloni, Alessandro; Prencipe, Elisabetta; Ritman, Jim; Ryan, Sinead; Thoma, Ulrike; Uwer, Ulrich; Weise, Wolfram
2016-04-01
We report on the EMMI Rapid Reaction Task Force meeting 'Resonances in QCD', which took place at GSI October 12-14, 2015. A group of 26 people met to discuss the physics of resonances in QCD. The aim of the meeting was defined by the following three key questions: What is needed to understand the physics of resonances in QCD? Where does QCD lead us to expect resonances with exotic quantum numbers? What experimental efforts are required to arrive at a coherent picture? For light mesons and baryons only those with up, down and strange quark content were considered. For heavy-light and heavy-heavy meson systems, those with charm quarks were the focus. This document summarizes the discussions by the participants, which in turn led to the coherent conclusions we present here.
Lutz, Matthias F M; Pennington, Michael; Bettoni, Diego; Brambilla, Nora; Crede, Volker; Eidelman, Simon; Gillitzer, Albrecht; Gradl, Wolfgang; Lang, Christian B; Metag, Volker; Nieves, Juan; Neubert, Sebastian; Oka, Makoto; Olsen, Steve L; Pappagallo, Marco; Paul, Stephan; Pelizäus, Marc; Pilloni, Alessandro; Prencipe, Elisabetta; Ritman, Jim; Ryan, Sinead; Thoma, Ulrike; Uwer, Ulrich; Weise, Wolfram
2015-01-01
We report on the EMMI Rapid Reaction Task Force meeting 'Resonances in QCD', which took place at GSI October 12-14, 2015. A group of 26 people met to discuss the physics of resonances in QCD. The aim of the meeting was defined by the following three key questions: What is needed to understand the physics of resonances in QCD? Where does QCD lead us to expect resonances with exotic quantum numbers? What experimental efforts are required to arrive at a coherent picture? For light mesons and baryons only those with ${\\it up}$, ${\\it down}$ and ${\\it strange}$ quark content were considered. For heavy-light and heavy-heavy meson systems, those with ${\\it charm}$ quarks were the focus. This document summarizes the discussions by the participants, which in turn led to the coherent conclusions we present here.
Lattices of dielectric resonators
Trubin, Alexander
2016-01-01
This book provides the analytical theory of complex systems composed of a large number of high-Q dielectric resonators. Spherical and cylindrical dielectric resonators with inferior and also whispering gallery oscillations allocated in various lattices are considered. A new approach to S-matrix parameter calculations based on perturbation theory of Maxwell equations, developed for a number of high-Q dielectric bodies, is introduced. All physical relationships are obtained in analytical form and are suitable for further computations. Essential attention is given to a new unified formalism of the description of scattering processes. The general scattering task for coupled eigen oscillations of the whole system of dielectric resonators is described. The equations for the expansion coefficients are explained in an applicable way. The temporal Green functions for the dielectric resonator are presented. The scattering process of short pulses in dielectric filter structures, dielectric antennas and lattices of d...
Piazza, Gianluca
2017-01-01
This book introduces piezoelectric microelectromechanical (pMEMS) resonators to a broad audience by reviewing design techniques including use of finite element modeling, testing and qualification of resonators, and fabrication and large scale manufacturing techniques to help inspire future research and entrepreneurial activities in pMEMS. The authors discuss the most exciting developments in the area of materials and devices for the making of piezoelectric MEMS resonators, and offer direct examples of the technical challenges that need to be overcome in order to commercialize these types of devices. Some of the topics covered include: Widely-used piezoelectric materials, as well as materials in which there is emerging interest Principle of operation and design approaches for the making of flexural, contour-mode, thickness-mode, and shear-mode piezoelectric resonators, and examples of practical implementation of these devices Large scale manufacturing approaches, with a focus on the practical aspects associate...
Perspective on resonances of metamaterials.
Min, Li; Huang, Lirong
2015-07-27
Electromagnetic resonance as the most important characteristic of metamaterials enables lots of exotic phenomena, such as invisible, negative refraction, man-made magnetism, etc. Conventional LC-resonance circuit model as the most authoritative and classic model is good at explaining and predicting the fundamental resonance wavelength of a metamaterial, while feels hard for high-order resonances, especially for resonance intensity (strength of resonance, determining on the performance and efficiency of metamaterial-based devices). In present work, via an easy-to-understand mass-spring model, we present a different and comprehensive insight for the resonance mechanism of metamaterials, through which both the resonance wavelengths (including the fundamental and high-order resonance wavelengths) and resonance intensities of metamaterials can be better understood. This developed theory has been well verified by different-material and different-structure resonators. This perspective will provide a broader space for exploring novel optical devices based on metamaterials (or metasurfaces).
Geometric Stochastic Resonance
Ghosh, Pulak Kumar; Savel'ev, Sergey E; Nori, Franco
2015-01-01
A Brownian particle moving across a porous membrane subject to an oscillating force exhibits stochastic resonance with properties which strongly depend on the geometry of the confining cavities on the two sides of the membrane. Such a manifestation of stochastic resonance requires neither energetic nor entropic barriers, and can thus be regarded as a purely geometric effect. The magnitude of this effect is sensitive to the geometry of both the cavities and the pores, thus leading to distinctive optimal synchronization conditions.
Peters, Roswell D. M.
1982-01-01
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.
Resonant dielectric metamaterials
Loui, Hung; Carroll, James; Clem, Paul G; Sinclair, Michael B
2014-12-02
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.
Not-so-resonant, resonant absorption
Brunel, F.
1987-07-01
When an intense electromagnetic wave is incident obliquely on a sharply bounded overdense plasma, strong energy absorption can be accounted for by the electrons that are dragged into the vacuum and sent back into the plasma with velocities v~=vosc. This mechanism is more efficient than usual resonant absorption for vosc/ω>L, with L being the density gradient length. In the very high-intensity CO2-laser-target interaction, this mechanism may account for most of the energy absorption.
Magnetic resonance imaging; Imagerie par resonance magnetique
Energy Technology Data Exchange (ETDEWEB)
Fontanel, F. [Centre Hospitalier, 40 - Mont-de -Marsan (France); Clerc, T. [Centre Hospitalier Universitaire, 76 - Rouen (France); Theolier, S. [Hospice Civils de Lyon, 69 - Lyon (France); Verdenet, J. [Centre Hospitalier Universitaire, 25 - Besancon (France)
1997-04-01
The last improvements in nuclear magnetic resonance imaging are detailed here, society by society with an expose of their different devices. In the future the different technological evolutions will be on a faster acquisition, allowing to reduce the examination time, on the development of a more acute cardiac imaging, of a functional neuro-imaging and an interactive imaging for intervention. With the contrast products, staying a longer time in the vascular area, the angiography will find its place. Finally, the studies on magnetic fields should allow to increase the volume to examine. (N.C.).
Hyperbolic Resonances of Metasurface Cavities
Keene, David
2015-01-01
We propose a new class of optical resonator structures featuring one or two metasurface reflectors or metacavities and predict that such resonators support novel hyperbolic resonances. As an example of such resonances we introduce hyperbolic Tamm plasmons (HTPs) and hyperbolic Fabry-Perot resonances (HFPs). The hyperbolic optical modes feature low-loss incident power re-distribution over TM and TE polarization output channels, clover-leaf anisotropic dispersion, and other unique properties which are tunable and are useful for multiple applications.
Directory of Open Access Journals (Sweden)
Downie E.J.
2014-06-01
Full Text Available The quest to understand the physics of any system cannot be said to be complete as long as one cannot predict and fully understand its resonance spectrum. Despite this, due to the experimental challenge of the required double polarization measurements and the difficulty in achieving unambiguous, model-independent extraction and interpretation of the nucleon resonance spectrum of many broad and overlapping resonances, understanding of the structure and dynamics of the nucleon has suffered. The recent improvement in statistical quality and kinematic range of the data made available by such full-solid-angle systems as the CB and TAPS constellation at MAMI, coupled with the high flux polarized photon beam provided by the Glasgow Photon Tagger, and the excellent properties of the Mainz Frozen Spin Target, when paired with new developments in Partial Wave Analysis (PWA methodology make this a very exciting and fruitful time in nucleon resonance studies. Here the recent influx of data and PWA developments are summarized, and the requirements for a complete, unambiguous PWA solution over the first and second resonance region are briefly reviewed.
Kuznetsov, Arseniy I; Fu, Yuan Hsing; Viswanathan, Vignesh; Rahmani, Mohsen; Valuckas, Vytautas; Kivshar, Yuri; Pickard, Daniel S; Lukiyanchuk, Boris
2014-01-01
We introduce a new concept of split-ball resonator and demonstrate a strong omnidirectional magnetic dipole response for both gold and silver spherical plasmonic nanoparticles with nanometer-scale cuts. Tunability of the magnetic dipole resonance throughout the visible spectral range is demonstrated by a change of the depth and width of the nanoscale cut. We realize this novel concept experimentally by employing the laser-induced transfer method to produce near-perfect spheres and helium ion beam milling to make cuts with the nanometer resolution. Due to high quality of the spherical particle shape, governed by strong surface tension forces during the laser transfer process, and the clean, straight side walls of the cut made by helium ion milling, magnetic resonance is observed at 600 nm in gold and at 565 nm in silver nanoparticles. Structuring arbitrary features on the surface of ideal spherical resonators with nanoscale dimensions provides new ways of engineering hybrid resonant modes and ultra-high near-f...
The Resonant Transneptunian Populations
Gladman, B; Petit, J-M; Kavelaars, J; Jones, R L; Parker, J Wm; Van Laerhoven, C; Nicholson, P; Rousselot, P; Bieryla, A; Ashby, M L N
2012-01-01
The transneptunian objects (TNOs) trapped in mean-motion resonances with Neptune were likely emplaced there during planet migration late in the giant-planet formation process. We perform detailed modelling of the resonant objects detected in the Canada-France Ecliptic Plane Survey (CFEPS) in order to provide population estimates and, for some resonances, constrain the complex internal orbital element distribution. Detection biases play a critical role because phase relationships with Neptune make object discovery more likely at certain longitudes. This paper discusses the 3:2, 5:2, 2:1, 3:1, 5:1, 4:3, 5:3, 7:3, 5:4, and 7:4 mean-motion resonances, all of which had CFEPS detections, along with our upper limit on 1:1 Neptune Trojans (which is consistent with their small population estimated elsewhere). For the plutinos (TNOs in the 3:2 resonance) we refine the orbital element distribution given in Kavelaars et al. (2009) and show that steep H-magnitude distributions (N(H) proportional to 10aH, with a=0.8-0.9) a...
Kolpakov, Stanislav A; Loika, Yuri; Tarasov, Nikita; Kalashnikov, Vladimir; Agrawal, Govind P
2015-01-01
A mode locked fibre laser as a source of ultra-stable pulse train has revolutionised a wide range of fundamental and applied research areas by offering high peak powers, high repetition rates, femtosecond range pulse widths and a narrow linewidth. However, further progress in linewidth narrowing seems to be limited by the complexity of the carrier-envelope phase control. Here for the first time we demonstrate experimentally and theoretically a new mechanism of resonance vector self-mode locking where tuning in-cavity birefringence leads to excitation of the longitudinal modes sidebands accompanied by the resonance phase locking of sidebands with the adjacent longitudinal modes. An additional resonance with acoustic phonons provides the repetition rate tunability and linewidth narrowing down to Hz range that drastically reduces the complexity of the carrier-envelope phase control and so will open the way to advance lasers in the context of applications in metrology, spectroscopy, microwave photonics, astronomy...
Quartz resonator processing system
Peters, Roswell D. M.
1983-01-01
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.
Reconfigurable optical routers based on Coupled Resonator Induced Transparency resonances.
Mancinelli, M; Bettotti, P; Fedeli, J M; Pavesi, L
2012-10-08
The interferometric coupling of pairs of resonators in a resonator sequence generates coupled ring induced transparency (CRIT) resonances. These have quality factors an order of magnitude greater than those of single resonators. We show that it is possible to engineer CRIT resonances in tapered SCISSOR (Side Coupled Integrated Space Sequence of Resonator) to realize fast and efficient reconfigurable optical switches and routers handling several channels while keeping single channel addressing capabilities. Tapered SCISSORs are fabricated in silicon-on-insulator technology. Furthermore, tapered SCISSORs show multiple-channel switching behavior that can be exploited in DWDM applications.
Amin, Muhammad
2014-07-01
The resonances with asymmetric Fano line-shapes were originally discovered in the context of quantum mechanics (U. Fano, Phys. Rev., 124, 1866-1878, 1961). Quantum Fano resonances were generated from destructive interference of a discrete state with a continuum one. During the last decade this concept has been applied in plasmonics where the interference between a narrowband polariton and a broader one has been used to generate electromagnetically induced transparency (EIT) (M. Rahmani, et al., Laser Photon. Rev., 7, 329-349, 2013).
Pygmy resonances and nucleosynthesis
Tsoneva, Nadia
2014-01-01
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.
Nanoantenna using mechanical resonance
Chang Hwa Lee,
2010-11-01
Nanoantenna using mechanical resonance vibration is made from an indium tin oxide (ITO) coated vertically aligned nanorod array. Only this structure works as a radio with demodulator without any electrical circuit using field emission phenomenon. A top-down fabrication method of an ITO coated nanorod array is proposed using a modified UV lithography. The received radio frequency and the resonance frequency of nanoantenna can be controlled by the fabrication condition through the height of a nanorod array. The modulated signals are received successfully with the transmission carrier wave frequency (248MHz) and the proposed nanoantenna is expected to be used in communication system for ultra small scale sensor. ©2010 IEEE.
Directory of Open Access Journals (Sweden)
Wada Masayuki
2012-11-01
Full Text Available The results of resonance particle productions (ρ0, ω, K*, ϕ, Σ*, and Λ* measured by the STAR collaboration at RHIC from various colliding systems and energies are presented. Measured mass, width, 〈pT〉, and yield of those resonances are reviewed. No significant mass shifts or width broadening beyond the experiment uncertainties are observed. New measurements of ϕ and ω from leptonic decay channels are presented. The yields from leptonic decay channels are compared with the measurements from hadronic decay channels and the two results are consistent with each other.
Magnetic resonance of phase transitions
Owens, Frank J; Farach, Horacio A
1979-01-01
Magnetic Resonance of Phase Transitions shows how the effects of phase transitions are manifested in the magnetic resonance data. The book discusses the basic concepts of structural phase and magnetic resonance; various types of magnetic resonances and their underlying principles; and the radiofrequency methods of nuclear magnetic resonance. The text also describes quadrupole methods; the microwave technique of electron spin resonance; and the Mössbauer effect. Phase transitions in various systems such as fluids, liquid crystals, and crystals, including paramagnets and ferroelectrics, are also
Resonant filtered fiber amplifiers
DEFF Research Database (Denmark)
Alkeskjold, Thomas Tanggaard; Laurila, Marko; Olausson, Christina Bjarnal Thulin
2013-01-01
In this paper we present our recent result on utilizing resonant/bandgap fiber designs to achieve high performance ytterbium doped fiber amplifers for achieving diffraction limited beam quality in large mode area fibers, robust bending performance and gain shaping for long wavelength operation...
DEFF Research Database (Denmark)
Ansbæk, Thor; Chung, Il-Sug; Semenova, Elizaveta;
2013-01-01
We demonstrate how resonant excitation of a microelectro-mechanical system can be used to increase the tuning range of a vertical-cavity surface-emitting laser two-fold by enabling both blue- and red-shifting of the wavelength. In this way a short-cavity design enabling wide tuning range can be r...
Neutron resonance spectroscopy
Energy Technology Data Exchange (ETDEWEB)
Gunsing, F
2005-06-15
The present document has been written in order to obtain the diploma 'Habilitation a Diriger des Recherches'. Since this diploma is indispensable to supervise thesis students, I had the intention to write a document that can be useful for someone starting in the field of neutron resonance spectroscopy. Although the here described topics are already described elsewhere, and often in more detail, it seemed useful to have most of the relevant information in a single document. A general introduction places the topic of neutron-nucleus interaction in a nuclear physics context. The large variations of several orders of magnitude in neutron-induced reaction cross sections are explained in terms of nuclear level excitations. The random character of the resonances make nuclear model calculation predictions impossible. Then several fields in physics where neutron-induced reactions are important and to which I have contributed in some way or another, are mentioned in a first synthetic chapter. They concern topics like parity nonconservation in certain neutron resonances, stellar nucleosynthesis by neutron capture, and data for nuclear energy applications. The latter item is especially important for the transmutation of nuclear waste and for alternative fuel cycles. Nuclear data libraries are also briefly mentioned. A second chapter details the R-matrix theory. This formalism is the foundation of the description of the neutron-nucleus interaction and is present in all fields of neutron resonance spectroscopy. (author)
Electrically detected ferromagnetic resonance
Goennenwein, S.T.B.; Schink, S.W.; Brandlmaier, A.; Boger, A.; Opel, M.; Gross, R.; Keizer, R.S.; Klapwijk, T.M.; Gupta, A.; Huebl, H.; Bihler, C.; Brandt, M.S.
2007-01-01
We study the magnetoresistance properties of thin ferromagnetic CrO2 and Fe3O4 films under microwave irradiation. Both the sheet resistance ρ and the Hall voltage VHall characteristically change when a ferromagnetic resonance (FMR) occurs in the film. The electrically detected ferromagnetic resonanc
Simulation of quartz resonators
Weinmann, M.; Radius, R.; Mohr, R.
Quartz resonators are suitable as novel sensor elements in the field of profilometry and three dimensional measurement techniques. This application requires a tailoring of the oscillator circuit which is performed by a network analysis program. The equivalent network parameters are computed by a finite element analysis. The mechanical loading of the quartz is modeled by a viscous damping approach.
Wallace, John; Newman, Mike; Gutierrez, Homero; Hoffman, Charlie; Quakenbush, Tim; Waldeck, Dan; Leone, Christopher; Ostaszewski, Miro
2014-10-01
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 μrad 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.
DEFF Research Database (Denmark)
2013-01-01
A waveguide resonator comprising a number of side walls defining a cavity enclosed by said sidewalls defining the cavity; and two or more conductive plates extending into the cavity, each conductive plate having a first side and a second side opposite the first side, and wherein the conductive...
Functional Magnetic Resonance Imaging
Voos, Avery; Pelphrey, Kevin
2013-01-01
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…
Wireless ferroelectric resonating sensor.
Viikari, Ville; Seppa, Heikki; Mattila, Tomi; Alastalo, Ari
2010-04-01
This paper presents a passive wireless resonating sensor that is based on a ferroelectric varactor. The sensor replies with its data at an intermodulation frequency when a reader device illuminates it at 2 closely located frequencies. The paper derives a theoretical equation for the response of such a sensor, verifies the theory by simulations, and demonstrates a temperature sensor based on a ferroelectric varactor.
Single spin magnetic resonance
Wrachtrup, Jörg; Finkler, Amit
2016-08-01
Different approaches have improved the sensitivity of either electron or nuclear magnetic resonance to the single spin level. For optical detection it has essentially become routine to observe a single electron spin or nuclear spin. Typically, the systems in use are carefully designed to allow for single spin detection and manipulation, and of those systems, diamond spin defects rank very high, being so robust that they can be addressed, read out and coherently controlled even under ambient conditions and in a versatile set of nanostructures. This renders them as a new type of sensor, which has been shown to detect single electron and nuclear spins among other quantities like force, pressure and temperature. Adapting pulse sequences from classic NMR and EPR, and combined with high resolution optical microscopy, proximity to the target sample and nanoscale size, the diamond sensors have the potential to constitute a new class of magnetic resonance detectors with single spin sensitivity. As diamond sensors can be operated under ambient conditions, they offer potential application across a multitude of disciplines. Here we review the different existing techniques for magnetic resonance, with a focus on diamond defect spin sensors, showing their potential as versatile sensors for ultra-sensitive magnetic resonance with nanoscale spatial resolution.
Magnetic Resonance Imaging (MRI) Safety
... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) Safety What is MRI and how does it ... and MRI Breast-feeding and MRI What is MRI and how does it work? Magnetic resonance imaging, ...
Resonant photothermal IR spectroscopy of picogram samples with microstring resonator
DEFF Research Database (Denmark)
Yamada, Shoko; Schmid, Silvan; Boisen, Anja
2013-01-01
Here, we report a demonstration of resonant photothermal IR spectroscopy using microstrings in mid-infrared region providing rapid identification of picogram samples. In our microelectromechanical resonant photothermal IR spectroscopy system, samples are deposited directly on microstrings using...... an in-situ sampling method and the resonance frequency of the string is measured optically. Resonance frequency shifts, proportional to the absorbed heat, are recorded in real time as monochromatic infrared light is being scanned over the mid-infrared range. These resonant photothermal IR spectroscopy...
Children's (Pediatric) Magnetic Resonance Imaging
Full Text Available ... Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) uses a powerful ... of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a noninvasive medical ...
Magnetic Resonance Imaging (MRI) -- Head
Full Text Available ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head ... limitations of MRI of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is ...
Characterizing coupled MEMS resonators with an electrical resonator
Tao, Guowei; Choubey, Bhaskar
2016-10-01
Rapid development in micro/nano fabrication has enabled the shrinking of MEMS devices and the ability to fabricate them in large arrays. However, process variations and device mismatch have also raised testability issues in the MEMS industry. MEMS resonators have been coupled to simplify the characterization of the fabrication process and device performance using their collective behaviour. Perturbation analysis using eigenvalues can therefore be applied to extract the system matrix of coupled resonators. We propose a new way of perturbation analysis by coupling an electrical resonator to an array of MEMS resonators. The electrical resonator is simple in structure and easy to readout. It can also precisely control the amount of perturbation based on two available techniques. Coupling between MEMS resonators and electrical resonator opens a new window for process characterization, device testing, material characterization, as well as large sensors array actuation.
RESONANT CAVITY EXCITATION SYSTEM
Baker, W.R.; Kerns, Q.A.; Riedel, J.
1959-01-13
An apparatus is presented for exciting a cavity resonator with a minimum of difficulty and, more specifically describes a sub-exciter and an amplifier type pre-exciter for the high-frequency cxcitation of large cavities. Instead of applying full voltage to the main oscillator, a sub-excitation voltage is initially used to establish a base level of oscillation in the cavity. A portion of the cavity encrgy is coupled to the input of the pre-exciter where it is amplified and fed back into the cavity when the pre-exciter is energized. After the voltage in the cavity resonator has reached maximum value under excitation by the pre-exciter, full voltage is applied to the oscillator and the pre-exciter is tunned off. The cavity is then excited to the maximum high voltage value of radio frequency by the oscillator.
Parallel Magnetic Resonance Imaging
Uecker, Martin
2015-01-01
The main disadvantage of Magnetic Resonance Imaging (MRI) are its long scan times and, in consequence, its sensitivity to motion. Exploiting the complementary information from multiple receive coils, parallel imaging is able to recover images from under-sampled k-space data and to accelerate the measurement. Because parallel magnetic resonance imaging can be used to accelerate basically any imaging sequence it has many important applications. Parallel imaging brought a fundamental shift in image reconstruction: Image reconstruction changed from a simple direct Fourier transform to the solution of an ill-conditioned inverse problem. This work gives an overview of image reconstruction from the perspective of inverse problems. After introducing basic concepts such as regularization, discretization, and iterative reconstruction, advanced topics are discussed including algorithms for auto-calibration, the connection to approximation theory, and the combination with compressed sensing.
Directory of Open Access Journals (Sweden)
Soo-Min Choi
2016-07-01
Full Text Available We consider a resonant SIMP dark matter in models with two singlet complex scalar fields charged under a local dark U(1D. After the U(1D is broken down to a Z5 discrete subgroup, the lighter scalar field becomes a SIMP dark matter which has the enhanced 3→2 annihilation cross section near the resonance of the heavier scalar field. Bounds on the SIMP self-scattering cross section and the relic density can be fulfilled at the same time for perturbative couplings of SIMP. A small gauge kinetic mixing between the SM hypercharge and dark gauge bosons can be used to make SIMP dark matter in kinetic equilibrium with the SM during freeze-out.
Cross Resonant Optical Antenna
Biagioni, P.; Huang, J. S.; Duò, L.; Finazzi, M.; Hecht, B.
2009-06-01
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.
Matsumoto, S; Matsumoto, Sh.
2000-01-01
Time evolution of tunneling in thermal medium is examined using the real-time semiclassical formalism previously developed. Effect of anharmonic terms in the potential well is shown to give a new mechanism of resonance enhanced tunneling. If the friction from environment is small enough, this mechanism may give a very large enhancement for the tunneling rate. The case of the asymmetric wine bottle potential is worked out in detail.
Cross resonant optical antenna.
Biagioni, P; Huang, J S; Duò, L; Finazzi, M; Hecht, B
2009-06-26
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.
Injection-controlled laser resonator
Chang, J.J.
1995-07-18
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. 5 figs.
Persistence, resistance, resonance
Tsadka, Maayan
Sound cannot travel in a vacuum, physically or socially. The ways in which sound operates are a result of acoustic properties, and the ways by which it is considered to be music are a result of social constructions. Therefore, music is always political, regardless of its content: the way it is performed and composed; the choice of instrumentation, notation, tuning; the medium of its distribution; its inherent hierarchy and power dynamics, and more. My compositional praxis makes me less interested in defining a relationship between music and politics than I am in erasing---or at least blurring---the borders between them. In this paper I discuss the aesthetics of resonance and echo in their metaphorical, physical, social, and musical manifestations. Also discussed is a political aesthetic of resonance, manifested through protest chants. I transcribe and analyze common protest chants from around the world, categorizing and unifying them as universal crowd-mobilizing rhythms. These ideas are explored musically in three pieces. Sumud: Rhetoric of Resistance in Three Movements, for two pianos and two percussion players, is a musical interpretation of the political/social concept of sumud, an Arabic word that literally means "steadfastness" and represents Palestinian non-violent resistance. The piece is based on common protest rhythms and uses the acoustic properties inherent to the instruments. The second piece, Three Piano Studies, extends some of the musical ideas and techniques used in Sumud, and explores the acoustic properties and resonance of the piano. The final set of pieces is part of my Critical Mess Music Project. These are site-specific musical works that attempt to blur the boundaries between audience, performers and composer, in part by including people without traditional musical training in the process of music making. These pieces use the natural structure and resonance of an environment, in this case, locations on the UCSC campus, and offer an active
Parametric Resonance in Dynamical Systems
Nijmeijer, Henk
2012-01-01
Parametric Resonance in Dynamical Systems discusses the phenomenon of parametric resonance and its occurrence in mechanical systems,vehicles, motorcycles, aircraft and marine craft, and micro-electro-mechanical systems. The contributors provide an introduction to the root causes of this phenomenon and its mathematical equivalent, the Mathieu-Hill equation. Also included is a discussion of how parametric resonance occurs on ships and offshore systems and its frequency in mechanical and electrical systems. This book also: Presents the theory and principles behind parametric resonance Provides a unique collection of the different fields where parametric resonance appears including ships and offshore structures, automotive vehicles and mechanical systems Discusses ways to combat, cope with and prevent parametric resonance including passive design measures and active control methods Parametric Resonance in Dynamical Systems is ideal for researchers and mechanical engineers working in application fields such as MEM...
Directory of Open Access Journals (Sweden)
Rajiv K Gupta
2011-01-01
Full Text Available Initial stability at the placement and development of osseointegration are two major issues for implant survival. Implant stability is a mechanical phenomenon which is related to the local bone quality and quantity, type of implant, and placement technique used. The application of a simple, clinically applicable, non-invasive test to assess implant stability and osseointegration is considered highly desirable. Resonance frequency analysis (RFA is one of such techniques which is most frequently used now days. The aim of this paper was to review and analyze critically the current available literature in the field of RFA, and to also discuss based on scientific evidence, the prognostic value of RFA to detect implants at risk of failure. A search was made using the PubMed database to find all the literature published on "Resonance frequency analysis for implant stability" till date. Articles discussed in vivo or in vitro studies comparing RFA with other methods of implant stability measurement and articles discussing its reliability were thoroughly reviewed and discussed. A limited number of clinical reports were found. Various studies have demonstrated the feasibility and predictability of the technique. However, most of these articles are based on retrospective data or uncontrolled cases. Randomized, prospective, parallel-armed longitudinal human trials are based on short-term results and long-term follow up are still scarce in this field. Nonetheless, from available literature, it may be concluded that RFA technique evaluates implant stability as a function of stiffness of the implant bone interface and is influenced by factors such as bone type, exposed implant height above the alveolar crest. Resonance frequency analysis could serve as a non-invasive diagnostic tool for detecting the implant stability of dental implants during the healing stages and in subsequent routine follow up care after treatment. Future studies, preferably randomized
Electroexcitation of nucleon resonances
Energy Technology Data Exchange (ETDEWEB)
Inna Aznauryan, Volker D. Burkert
2012-01-01
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.
Resonance frequency in ferromagnetic superlattices
Energy Technology Data Exchange (ETDEWEB)
Qiu Rongke; Huang Andong [School of Science, Shenyang University of Technology, Shenyang 110870 (China); Li Da; Zhang Zhidong, E-mail: rkqiu@163.com [Shenyang National Laboratory for Materials Science, Institute of Metal Research and International Centre for Materials Physics, Chinese Academy of Sciences, Shenyang 110016 (China)
2011-10-19
The resonance frequency in two-layer and three-layer ferromagnetic superlattices is studied, using the Callen's Green function method, the Tyablikov decoupling approximation and the Anderson-Callen decoupling approximation. The effects of interlayer exchange coupling, anisotropy, external magnetic field and temperature on the resonance frequency are investigated. It is found that the resonance frequencies increase with increasing external magnetic field. In a parameter region of the asymmetric system, each sublayer corresponds to its own resonance frequency. The anisotropy of a sublayer affects only the resonance frequency corresponding to this sublayer. The stronger the anisotropy, the higher is the resonance frequency. The interlayer exchange coupling affects only the resonance frequencies belonging to the sublayers connected by it. The stronger the interlayer exchange coupling, the higher are the resonance frequencies. All the resonance frequencies decrease as the reduced temperature increases. The results direct the method to enhance and adjust the resonance frequency of magnetic multilayered materials with a wide band.
Search for resonant $\\widetilde\
Abdallah, J; Adam, W; Adzic, P; Albrecht, T; Alderweireld, T; Alemany-Fernandez, R; Allmendinger, T; Allport, P P; Amaldi, Ugo; Amapane, N; Amato, S; Anashkin, E; Andreazza, A; Andringa, S; Anjos, N; Antilogus, P; Apel, W D; Arnoud, Y; Ask, S; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Ballestrero, A; Bambade, P; Barbier, R; Bardin, Dimitri Yuri; Barker, G; Baroncelli, A; Battaglia, Marco; Baubillier, M; Becks, K H; Begalli, M; Behrmann, A; Ben-Haim, E; Benekos, N C; Benvenuti, Alberto C; Bérat, C; Berggren, M; Berntzon, L; Bertrand, D; Besançon, M; Besson, N; Bloch, D; Blom, M; Bluj, M; Bonesini, M; Boonekamp, M; Booth, P S L; Borisov, G; Botner, O; Bouquet, B; Bowcock, T J V; Boyko, I; Bracko, M; Brenner, R; Brodet, E; Brückman, P; Brunet, J M; Bugge, L; Buschmann, P; Calvi, M; Camporesi, T; Canale, V; Carena, F; Castro, N; Cavallo, F R; Chapkin, M M; Charpentier, P; Checchia, P; Chierici, R; Shlyapnikov, P; Chudoba, J; Chung, S U; Cieslik, K; Collins, P; Contri, R; Cosme, G; Cossutti, F; Costa, M J; Crawley, B; Crennell, D J; Cuevas-Maestro, J; D'Hondt, J; Dalmau, J; Da Silva, T; Da Silva, W; Della Ricca, G; De Angelis, A; de Boer, Wim; De Clercq, C; De Lotto, B; De Maria, N; De Min, A; De Paula, L S; Di Ciaccio, Lucia; Di Simone, A; Doroba, K; Drees, J; Dris, M; Eigen, G; Ekelöf, T J C; Ellert, M; Elsing, M; Espirito-Santo, M C; Fanourakis, G K; Fassouliotis, D; Feindt, Michael; Fernández, J; Ferrer, A; Ferro, F; Flagmeyer, U; Föth, H; Fokitis, E; Fulda-Quenzer, F; Fuster, J A; Gandelman, M; García, C; Gavillet, P; Gazis, E N; Geralis, T; Gokieli, R; Golob, B; Gómez-Ceballos, G; Gonçalves, P; Graziani, E; Grosdidier, G; Grzelak, K; Guy, J; Haag, C; Hallgren, A; Hamacher, K; Hamilton, K; Hansen, J; Haug, S; Hauler, F; Hedberg, V; Hennecke, M; Herr, H; Hoffman, J; Holmgren, S O; Holt, P J; Houlden, M A; Hultqvist, K; Jackson, J N; Jarlskog, G; Jarry, P; Jeans, D; Johansson, E K; Johansson, P D; Jonsson, P; Joram, C; Jungermann, L; Kapusta, F; Katsanevas, S; Katsoufis, E C; Kernel, G; Kersevan, Borut P; Kiiskinen, A P; King, B T; Kjaer, N J; Kluit, P; Kokkinias, P; Kourkoumelis, C; Kuznetsov, O; Krumshtein, Z; Kucharczyk, M; Lamsa, J; Leder, G; Ledroit, F; Leinonen, L; Leitner, R; Lemonne, J; Lepeltier, V; Lesiak, T; Liebig, W; Liko, D; Lipniacka, A; Lopes, J H; López, J M; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J; Malek, A; Maltezos, S; Mandl, F; Marco, J; Marco, R; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Masik, J; Mastroyiannopoulos, N; Matorras, F; Matteuzzi, C; Mazzucato, F; Mazzucato, M; McNulty, R; Meroni, C; Meyer, W T; Migliore, E; Mitaroff, W A; Mjörnmark, U; Moa, T; Moch, M; Mönig, K; Monge, R; Montenegro, J; Moraes, D; Moreno, S; Morettini, P; Müller, U; Münich, K; Mulders, M; Mundim, L M; Murray, W; Muryn, B; Myatt, Gerald; Myklebust, T; Nassiakou, M; Navarria, Francesco Luigi; Nawrocki, K; Nicolaidou, R; Nikolenko, M; Oblakowska-Mucha, A; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Österberg, K; Ouraou, A; Oyanguren, A; Paganoni, M; Paiano, S; Palacios, J P; Palka, H; Papadopoulou, T D; Pape, L; Parkes, C; Parodi, F; Parzefall, U; Passeri, A; Passon, O; Peralta, L; Perepelitsa, V F; Perrotta, A; Petrolini, A; Piedra, J; Pieri, L; Pierre, F; Pimenta, M; Piotto, E; Podobnik, T; Poireau, V; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Pukhaeva, N; Pullia, Antonio; Rames, J; Ramler, L; Read, A; Rebecchi, P; Rehn, J; Reid, D; Reinhardt, R; Renton, P B; Richard, F; Rídky, J; Rivero, M; Rodríguez, D; Romero, A; Ronchese, P; Rosenberg, E I; Roudeau, Patrick; Rovelli, T; Ruhlmann-Kleider, V; Ryabtchikov, D; Sadovskii, A; Salmi, L; Salt, J; Savoy-Navarro, A; Schwickerath, U; Segar, A; Sekulin, R L; Siebel, M; Sissakian, A N; Smadja, G; Smirnova, O G; Sokolov, A; Sopczak, A; Sosnowski, R; Spassoff, Tz; Stanitzki, M; Stocchi, A; Strauss, J; Stugu, B; Szczekowski, M; Szeptycka, M; Szumlak, T; Tabarelli de Fatis, T; Taffard, A C; Tegenfeldt, F; Timmermans, J; Tkatchev, L G; Tobin, M; Todorovova, S; Tomaradze, A G; Tomé, B; Tonazzo, A; Tortosa, P; Travnicek, P; Treille, D; Tristram, G; Trochimczuk, M; Troncon, C; Turluer, M L; Tyapkin, I A; Tyapkin, P; Tzamarias, S; Uvarov, V; Valenti, G; van Dam, P; Van Eldik, J; Van Lysebetten, A; Van Remortel, N; Van Vulpen, I B; Vegni, G; Veloso, F; Venus, W A; Verbeure, F; Verdier, P; Verzi, V; Vilanova, D; Vitale, L; Vrba, V; Wahlen, H; Washbrook, A J; Weiser, C; Wicke, D; Wickens, J H; Wilkinson, G; Winter, M; Witek, M; Yushchenko, O P; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zimin, N I; Zinchenko, A I; Zupan, M
2003-01-01
Searches for resonant ~nu production in e+e collisions under the assumption that R-parity is not conserved and that the dominant R-parity violating coupling is lambda121 or lambda131 used data recorded by DELPHI in 1997 to 2000 at centre-of-mass energies of 183 to 208 GeV. No deviation from the Standard Model was obs erved. Upper limits are given for the lambda121 and lamdba131 couplings as a function of the sneutrino mass and total width. The limits are especially stringent for sneutrino masses equal to the centre-of-mass energies with the highest integrated luminosities recorded.
Jensen, Kenneth J; Zettl, Alexander K; Weldon, Jeffrey A
2014-05-06
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.
Energy Technology Data Exchange (ETDEWEB)
McGarrie, Moritz
2012-07-15
We extend the framework of general gauge mediation to cases where the mediating fields have a nontrivial spectral function, as might arise from strong dynamics. We demonstrate through examples that this setup describes a broad class of possible models of gauge mediated supersymmetry breaking. A main emphasis is to give general formulas for cross sections for {sigma}(visible {yields} hidden) in these resonance models. We will also give formulas for soft masses, A-terms and demonstrate the framework with a holographic setup.
Musial, Walter [Boulder, CO; White, Darris [Superior, CO
2011-05-31
An apparatus (10) for applying at least one load to a specimen (12) according to one embodiment of the invention may comprise a mass (18). An actuator (20) mounted to the specimen (12) and operatively associated with the mass (18) moves the mass (18) along a linear displacement path (22) that is perpendicular to a longitudinal axis of the specimen (12). A control system (26) operatively associated with the actuator (20) operates the actuator (20) to reciprocate the mass (18) along the linear displacement path (22) at a reciprocating frequency, the reciprocating frequency being about equal to a resonance frequency of the specimen (12) in a test configuration.
Fast Resonance Frequency Modulation in Superconducting Stripline Resonator
Segev, Eran; Abdo, Baleegh; Shtempluck, Oleg; Buks, Eyal
2006-01-01
Fast resonance frequency modulation of a superconducting stripline resonator is investigated. The experiments are performed using a novel device which integrates a hot electron detector (HED) into a superconducting stripline ring resonator. Frequency modulation is demonstrated by both applying dc current or voltage to the HED, and by applying optical illumination, with modulation frequencies of up to 4.2GHz. Potential applications for such a device are in telecommunication, quantum cryptograp...
Miniaturised self-resonant split-ring resonator antenna
DEFF Research Database (Denmark)
Kim, Oleksiy S.; Breinbjerg, Olav
2009-01-01
A self-resonant miniaturized antenna composed of a broadside-coupled split-ring resonator (SRR) and an excitation arc-shaped monopole is presented. The size of the antenna and its resonance frequency is essentially defined by the SRR dimensions and geometry, while the input resistance...... at the resonance is governed by the arc length of the monopole. Numerical and experimental results are presented for an antenna configuration of 1/23.4 wavelength in diameter (ka~0.134). The antenna is tuned to 50 ohms without any matching network, and its efficiency is measured to be 17.5%....
Cyclotron resonant interactions in cosmic particle accelerators
Terasawa, T; 10.1007/s11214-012-9878-0
2012-01-01
A review is given for cyclotron resonant interactions in space plasmas. After giving a simple formulation for the test particle approach, illustrative examples for resonant interactions are given. It is shown that for obliquely propagating whistler waves, not only fundamental cyclotron resonance, but also other resonances, such as transit-time resonance, anomalous cyclotron resonance, higher-harmonic cyclotron resonance, and even subharmonic resonance can come into play. A few recent topics of cyclotron resonant interactions, such as electron injection in shocks, cyclotron resonant heating of solar wind heavy ions, and relativistic modifications, are also reviewed.
Nuclear Magnetic Resonance Gyroscope
Larsen, Michael; Griffith, Robert; Bulatowicz, Michael
2014-03-01
The navigation grade micro Nuclear Magnetic Resonance Gyroscope (micro-NMRG) being developed by the Northrop Grumman Corporation (NGC) has concluded 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 presentation will describe the operational principles, design basics, and demonstrated performance of the NMRG including an overview of the NGC designs developed and demonstrated in the DARPA gyro development program.
Electroexcitation of nucleon resonances
Aznauryan, I G
2011-01-01
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 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.
Fermi resonance in optical microcavities
Yi, Chang-Hwan; Yu, Hyeon-Hye; Lee, Ji-Won; Kim, Chil-Min
2015-04-01
Fermi resonance is a phenomenon of quantum mechanical superposition, which most often occurs between normal and overtone modes in molecular systems that are nearly coincident in energy. We find that scarred resonances in deformed dielectric microcavities are the very phenomenon of Fermi resonance, that is, a pair of quasinormal modes interact with each other due to coupling and a pair of resonances are generated through an avoided resonance crossing. Then the quantum number difference of a pair of quasinormal modes, which is a consequence of quantum mechanical superposition, equals periodic orbits, whereby the resonances are localized on the periodic orbits. We derive the relation between the quantum number difference and the periodic orbits and confirm it in an elliptic, a rectangular, and a stadium-shaped dielectric microcavity.
DISSIPATIVE DIVERGENCE OF RESONANT ORBITS
Energy Technology Data Exchange (ETDEWEB)
Batygin, Konstantin [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Morbidelli, Alessandro, E-mail: kbatygin@gps.caltech.edu [Departement Cassiopee, Universite de Nice-Sophia Antipolis, Observatoire de la Cote d' Azur, F-06304 Nice (France)
2013-01-01
A considerable fraction of multi-planet systems discovered by the observational surveys of extrasolar planets reside in mild proximity to first-order mean-motion resonances. However, the relative remoteness of such systems from nominal resonant period ratios (e.g., 2:1, 3:2, and 4:3) has been interpreted as evidence for lack of resonant interactions. Here, we show that a slow divergence away from exact commensurability is a natural outcome of dissipative evolution and demonstrate that libration of critical angles can be maintained tens of percent away from nominal resonance. We construct an analytical theory for the long-term dynamical evolution of dissipated resonant planetary pairs and confirm our calculations numerically. Collectively, our results suggest that a significant fraction of the near-commensurate extrasolar planets are in fact resonant and have undergone significant dissipative evolution.
Dissipative Divergence of Resonant Orbits
Batygin, Konstantin
2012-01-01
A considerable fraction of multi-planet systems discovered by the observational surveys of extrasolar planets reside in mild proximity to first-order mean motion resonances. However, the relative remoteness of such systems from nominal resonant period ratios (e.g. 2:1, 3:2, 4:3) has been interpreted as evidence for lack of resonant interactions. Here we show that a slow divergence away from exact commensurability is a natural outcome of dissipative evolution and demonstrate that libration of critical angles can be maintained tens of percent away from nominal resonance. We construct an analytical theory for the long-term dynamical evolution of dissipated resonant planetary pairs and confirm our calculations numerically. Collectively, our results suggest that a significant fraction of the near-commensurate extrasolar planets are in fact resonant and have undergone significant dissipative evolution.
Precession resonance in water waves
Lucas, Dan; Perlin, Marc
2016-01-01
We describe the theory and present numerical evidence for a new type of nonlinear resonant interaction between gravity waves on the surface of deep water. The resonance constitutes a generalisation of the usual 'exact' resonance as we show that exchanges of energy between the waves can be enhanced when the interaction is three-wave rather than four and the linear frequency mismatch, or detuning, is non-zero i.e. $\\omega_1\\pm\\omega_2\\pm\\omega_3 \
Advances in magnetic resonance 11
Waugh, John S
2013-01-01
Advances in Magnetic Resonance, Volume 11, presents a variety of contributions to the theory and practice of magnetic resonance. The book contains three chapters and begins with a discussion of the principles and applications of dynamic nuclear polarization, with emphasis on molecular motions and collisions, intermolecular couplings, and chemical interactions. Subsequent chapters focus on the assessment of a proposed broadband decoupling method and studies of time-domain (or Fourier transform) multiple-quantum nuclear magnetic resonance.
Efficient primary and parametric resonance excitation of bistable resonators
Ramini, Abdallah
2016-09-12
We experimentally demonstrate an efficient approach to excite primary and parametric (up to the 4th) resonance of Microelectromechanical system MEMS arch resonators with large vibrational amplitudes. A single crystal silicon in-plane arch microbeam is fabricated such that it can be excited axially from one of its ends by a parallel-plate electrode. Its micro/nano scale vibrations are transduced using a high speed camera. Through the parallel-plate electrode, a time varying electrostatic force is applied, which is converted into a time varying axial force that modulates dynamically the stiffness of the arch resonator. Due to the initial curvature of the structure, not only parametric excitation is induced, but also primary resonance. Experimental investigation is conducted comparing the response of the arch near primary resonance using the axial excitation to that of a classical parallel-plate actuation where the arch itself forms an electrode. The results show that the axial excitation can be more efficient and requires less power for primary resonance excitation. Moreover, unlike the classical method where the structure is vulnerable to the dynamic pull-in instability, the axial excitation technique can provide large amplitude motion while protecting the structure from pull-in. In addition to primary resonance, parametrical resonances are demonstrated at twice, one-half, and two-thirds the primary resonance frequency. The ability to actuate primary and/or parametric resonances can serve various applications, such as for resonator based logic and memory devices. (C) 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license
Electromagnetic production of hyperon resonances
Energy Technology Data Exchange (ETDEWEB)
K. Hicks, D. Keller, W. Tang
2011-10-01
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.
Advances in magnetic resonance 12
Waugh, John S
2013-01-01
Advances in Magnetic Resonance, Volume 12, presents a variety of contributions to the theory and practice of magnetic resonance. The book contains six chapters and begins with a discussion of diffusion and self-diffusion measurements by nuclear magnetic resonance. This is followed by separate chapters on spin-lattice relaxation time in hydrogen isotope mixtures; the principles of optical detection of nuclear spin alignment and nuclear quadropole resonance; and the spin-1 behavior, including the relaxation of the quasi-invariants of the motion of a system of pairs of dipolar coupled spin-1/2 nu
Orbital resonances around black holes.
Brink, Jeandrew; Geyer, Marisa; Hinderer, Tanja
2015-02-27
We compute the length and time scales associated with resonant orbits around Kerr black holes for all orbital and spin parameters. Resonance-induced effects are potentially observable when the Event Horizon Telescope resolves the inner structure of Sgr A*, when space-based gravitational wave detectors record phase shifts in the waveform during the resonant passage of a compact object spiraling into the black hole, or in the frequencies of quasiperiodic oscillations for accreting black holes. The onset of geodesic chaos for non-Kerr spacetimes should occur at the resonance locations quantified here.
Theory of Adiabatic Fountain Resonance
Williams, Gary A.
2017-01-01
The theory of "Adiabatic Fountain Resonance" with superfluid ^4{He} is clarified. In this geometry a film region between two silicon wafers bonded at their outer edge opens up to a central region with a free surface. We find that the resonance in this system is not a Helmholtz resonance as claimed by Gasparini et al., but in fact is a fourth sound resonance. We postulate that it occurs at relatively low frequency because the thin silicon wafers flex appreciably from the pressure oscillations of the sound wave.
Frequency Resonance in Stochastic Systems
Institute of Scientific and Technical Information of China (English)
钱敏; 张雪娟
2003-01-01
The phenomenon of frequency resonance, which is usually related to deterministic systems, is investigated in stochastic systems. We show that for those autonomous systems driven only by white noise, if the output power spectrum exhibits a nonzero peak frequency, then applying a periodic signel just on this noise-induced central frequency can also induce a resonance phenomenon, which we call the frequency stochastic resonance. The effect of such a resonance in a coupled stochastic system is shown to be much better than that in a single-oscillator system.
Advances in magnetic resonance 6
Waugh, John S
2013-01-01
Advances in Magnetic Resonance, Volume 6 focuses on the theoretical and practical aspects of applying magnetic resonance methods to various problems in physical chemistry, emphasizing the different aspects of the exegesis of these problems. This book discusses the gas phase magnetic resonance of electronically excited molecules; techniques for observing excited electronic states; NMR studies in liquids at high pressure; and effect of pressure on self-diffusion in liquids. The nuclear magnetic resonance investigations of organic free radicals; measurement of proton coupling constants by NMR; an
Novel resonant cantilever mass change detection and resonant frequency tuning
DEFF Research Database (Denmark)
Grigorov, Alexander; Boisen, Anja
2005-01-01
This paper reports a novel way to detect the resonant frequency of an electro-thermally actuated cantilever sensor that we have previously reported, in order to perform mass detection by resonant frequency shift detection. The device is based on monitoring the rupture of a clamped cantilever stru...
Nonlinear Oscillations of Microscale Piezoelectric Resonators and Resonator Arrays
2006-06-30
static buckling deflection of the resonator d3E, kI(x) d 3 , k(x) can be expressed as Elt -t = Elk ----- T- at X = Xk-_ Here, it is important to note that...a number of the parameters can resonators clearly reveal nonlinear characteristics. Although b icted by usng the ro rg met ersal the dimensions of
Geometrically Protected Resonance Modes and Optical Fano Resonances
Regan, Emma C; Lopez, Josue J; Hsu, Chia Wei; Zhen, Bo; Joannopoulos, John D; Soljacic, Marin
2015-01-01
Traditionally, photonic crystal slabs can support resonances that are strongly confined to the slab but also couple to external radiation. However, when a photonic crystal slab is placed on a substrate, the resonance modes become less confined, and as the index contrast between slab and substrate decreases, they eventually disappear. Using the scale structure of the Dione Juno butterfly wing as an inspiration, we present a low-index zigzag surface structure that supports resonance modes even without index contrast with the substrate. The zigzag structure supports resonances that are contained away from the substrate; this geometrically protects the modes from coupling to the substrate. We experimentally verify the protected resonance property of the zigzag structure in the visible wavelength regime. Potential applications include substrate-independent structural color and light guiding.
Slope tunable Fano resonances in asymmetric embedded microring resonators
Wang, Gencheng; Dai, Tingge; Jiang, Jianfei; Yu, Hui; Hao, Yinlei; Wang, Yuehai; Li, Yubo; Jiang, Xiaoqing; Yang, Jianyi
2017-02-01
An asymmetric embedded microring resonant system is proposed and fabricated on a silicon-on-insulator (SOI) to achieve slope tunable Fano resonances. The Fano resonances originate from the nonlinear phase shift produced by adding an inner ring coupling with the outer ring. The slope of the Fano resonance can be well tuned to be ultra-high by controlling the microheaters to adjust the phase condition. Experimentally, we observe Fano resonance with a maximum extinction ratio of about 40 dB, and the slope can be tuned from -35 dB nm-1 to -93 dB nm-1, which shows good agreement with the theoretical analysis. This device could find potential applications in ultra-high sensitivity sensing systems.
Durka, R
2016-01-01
We explore the $S$-expansion framework to analyze freedom in closing the multiplication tables for the abelian semigroups. Including possibility of the zero element in the resonant decomposition and relating the Lorentz generator with the semigroup identity element leads to the wide class of the expanded Lie algebras introducing interesting modifications to the gauge gravity theories. Among the results we find not only all the Maxwell algebras of type $\\mathfrak{B}_m$, $\\mathfrak{C}_m$, and recently introduced $\\mathfrak{D}_m$, but we also produce new examples. We discuss some prospects concerning further enlarging the algebras and provide all necessary constituents for constructing the gravity actions based on the obtained results.
Durka, R.
2017-04-01
The S-expansion framework is analyzed in the context of a freedom in closing the multiplication tables for the abelian semigroups. Including the possibility of the zero element in the resonant decomposition, and associating the Lorentz generator with the semigroup identity element, leads to a wide class of the expanded Lie algebras introducing interesting modifications to the gauge gravity theories. Among the results, we find all the Maxwell algebras of type {{B}m} , {{C}m} , and the recently introduced {{D}m} . The additional new examples complete the resulting generalization of the bosonic enlargements for an arbitrary number of the Lorentz-like and translational-like generators. Some further prospects concerning enlarging the algebras are discussed, along with providing all the necessary constituents for constructing the gravity actions based on the obtained results.
Energy Technology Data Exchange (ETDEWEB)
Dudek, Jozef [Old Dominion Univ., Norfolk, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2016-03-01
I describe how hadron-hadron scattering amplitudes are related to the eigenstates of QCD in a finite cubic volume. The discrete spectrum of such eigenstates can be determined from correlation functions computed using lattice QCD, and the corresponding scattering amplitudes extracted. I review results from the Hadron Spectrum Collaboration who have used these finite volume methods to study ππ elastic scattering, including the ρ resonance, as well as coupled-channel πK, ηK scattering. The very recent extension to the case where an external current acts is also presented, considering the reaction πγ* → ππ, from which the unstable ρ → πγ transition form factor is extracted. Ongoing calculations are advertised and the outlook for finite volume approaches is presented.
Dorbolo, S; Vandewalle, N; Gilet, T
2008-01-01
When an oil droplet is placed on a quiescent oil bath, it eventually collapses into the bath due to gravity. The resulting coalescence may be eliminated when the bath is vertically vibrated. The droplet bounces periodically on the bath, and the air layer between the droplet and the bath is replenished at each bounce. This sustained bouncing motion is achieved when the forcing acceleration is higher than a threshold value. When the droplet has a sufficiently low viscosity, it significantly deforms : spherical harmonic \\boldmath{$Y_{\\ell}^m$} modes are excited, resulting in resonant effects on the threshold acceleration curve. Indeed, a lower acceleration is needed when $\\ell$ modes with $m=0$ are excited. Modes $m \
Langlois, Michel; Peillex-Delphe, Guy
2005-01-01
Particle accelerators need radio frequency sources. Above 300 MHz, the amplifiers mostly used high power klystrons developed for this sole purpose. As for military equipment, users are drawn to buy "off the shelf" components rather than dedicated devices. IOTs have replaced most klystrons in TV transmitters and find their way in particle accelerators. They are less bulky, easier to replace, more efficient at reduced power. They are also far less powerful. What is the benefit of very compact sources if huge 3 dB couplers are needed to combine the power? To alleviate this drawback, we investigated a resonant combiner, operating in TM010 mode, able to combine 3 to 5 IOTs. Our IOTs being able to deliver 80 kW C.W. apiece, combined power would reach 400 kW minus the minor insertion loss. Values for matching and insertion loss are given. The behavior of the system in case of IOT failure is analyzed.
Clarke, Allan J.; Van Gorder, Stephen
2016-04-01
Near the bottom of a narrow canyon currents that oscillate back and forth along the bottom slope hx in a stratified ocean of buoyancy frequency N do so with a natural internal gravitational frequency Nhx. From May 2012 to May 2013 Acoustic Doppler Current Profiler measurements were made at 715 m depth in the deep narrow part of the DeSoto Canyon south of Pensacola, Florida, in water with 2π/Nhx ≈ 2.5 days. Above the canyon the flow follows the large-scale isobaths, but beneath the canyon rim the current oscillates along the canyon axis with 2-3 day periodicity, and is much stronger than and uncorrelated with the overlying flow. A simple theoretical model explains the resonant response. Published observations from the Hudson and Gully canyons suggest that the strong subinertial current oscillations observed in these canyons occur close to the relevant local frequency Nhx, consistent with the proposed simple model physics.
MRI (Magnetic Resonance Imager)
Energy Technology Data Exchange (ETDEWEB)
Suzuki, Yoshinori [Toshiba Corp., Kawasaki, Kanagawa (Japan)
1995-05-01
MRI is a widely used diagnostic imaging modality because it has excellent diagnostic capabilities, is safe to use and generates images not affected by bone artifacts. Images are obtained by utilizing the phenomenon of Nuclear Magnetic Resonance (NMR) by which protons located in a static magnetic field absorb radio frequency (RF) pulses with a specific frequency and release a part of the energy as a NMR signal. Potentially MRI has the ability to provide functional and metabolic information (such as flow, temperature, diffusion, neuron activity) in addition to morphological information. This paper describes the imaging principles and provides a general outline of some applications: flow imaging, metabolite imaging and temperature imaging. (J.P.N.).
Cascaded resonant bridge converters
Stuart, Thomas A. (Inventor)
1989-01-01
A converter for converting a low voltage direct current power source to a higher voltage, high frequency alternating current output for use in an electrical system where it is desired to use low weight cables and other circuit elements. The converter has a first stage series resonant (Schwarz) converter which converts the direct current power source to an alternating current by means of switching elements that are operated by a variable frequency voltage regulator, a transformer to step up the voltage of the alternating current, and a rectifier bridge to convert the alternating current to a direct current first stage output. The converter further has a second stage series resonant (Schwarz) converter which is connected in series to the first stage converter to receive its direct current output and convert it to a second stage high frequency alternating current output by means of switching elements that are operated by a fixed frequency oscillator. The voltage of the second stage output is controlled at a relatively constant value by controlling the first stage output voltage, which is accomplished by controlling the frequency of the first stage variable frequency voltage controller in response to second stage voltage. Fault tolerance in the event of a load short circuit is provided by making the operation of the first stage variable frequency voltage controller responsive to first and second stage current limiting devices. The second stage output is connected to a rectifier bridge whose output is connected to the input of the second stage to provide good regulation of output voltage wave form at low system loads.
Baryon Spectroscopy and Resonances
Energy Technology Data Exchange (ETDEWEB)
Robert Edwards
2011-12-01
A short review of current efforts to determine the highly excited state spectrum of QCD, and in particular baryons, using lattice QCD techniques is presented. The determination of the highly excited spectrum of QCD is a major theoretical and experimental challenge. The experimental investigation of the excited baryon spectrum has been a long-standing element of the hadronic-physics program, an important component of which is the search for so-called 'missing resonances', baryonic states predicted by the quark model based on three constituent quarks but which have not yet been observed experimentally. Should such states not be found, it may indicate that the baryon spectrum can be modeled with fewer effective degrees of freedom, such as in quark-diquark models. In the past decade, there has been an extensive program to collect data on electromagnetic production of one and two mesons at Jefferson Lab, MIT-Bates, LEGS, MAMI, ELSA, and GRAAL. To analyze these data, and thereby refine our knowledge of the baryon spectrum, a variety of physics analysis models have been developed at Bonn, George Washington University, Jefferson Laboratory and Mainz. To provide a theoretical determination and interpretation of the spectrum, ab initio computations within lattice QCD have been used. Historically, the calculation of the masses of the lowest-lying states, for both baryons and mesons, has been a benchmark calculation of this discretized, finite-volume computational approach, where the aim is well-understood control over the various systematic errors that enter into a calculation; for a recent review. However, there is now increasing effort aimed at calculating the excited states of the theory, with several groups presenting investigations of the low-lying excited baryon spectrum, using a variety of discretizations, numbers of quark flavors, interpolating operators, and fitting methodologies. Some aspects of these calculations remain unresolved and are the subject of
Multiphonon giant resonances in nuclei
Energy Technology Data Exchange (ETDEWEB)
Aumann, T. [Mainz Univ. (Germany). Inst. fuer Kernchemie; Bortignon, P.F. [Milan Univ. (Italy). Dipt. di Fisica]|[Istituto Nazionale di Fisica Nucleare, Milan (Italy); Emling, H. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany)
1998-07-01
We review the present knowledge of multiphonon giant resonances in nuclei. Theoretical concepts approaching the intrinsic structure and excitation mechanisms of multi-phonon states are discussed. The available experimental results are summarized, including a brief description of applied techniques. This review emphasizes electromagnetic excitations of double dipole resonances. Open questions and possible routes toward a solution are addressed. (orig.)
The Resonance of Renaissance Poetry.
Greenblatt, Stephen
1980-01-01
Discusses reading and teaching Renaissance poetry in terms of the poem's "resonance," its capacity to speak to contemporary readers directly and draw them into its historical world. Advises teachers to expand the resonance to illuminate the poem's background, as exemplified by the poetry of Thomas Wyatt in the court of Henry VIII. (DF)
Color confinement multi quark resonance
Energy Technology Data Exchange (ETDEWEB)
Wang Fan [Department of Physics, Nanjing University, Joint Center for Particle Nuclear Physics and Cosmology, Nanjing University and Pupil Mountain Observatory, Nanjing, 210008 (China); Ping, J.L. [Department of Physics, Nanjing Normal University, Nanjing, 210097 (China); Pang, H.R. [Department of Physics, Southeast University, Nanjing, 210008 (China); Chen, L.Z. [Department of Physics, Nanjing University, Joint Center for Particle Nuclear Physics and Cosmology, Nanjing University and Pupil Mountain Observatory, Nanjing, 210008 (China)
2007-06-15
A new kind microscopic resonance, the color confinement multi quark resonance is proposed and studied. The quark delocalization color screening model is compared to one of the chiral quark model, the Salamanca model, and a new mechanism of the intermediate range NN interaction, the mutual distortion of interacting nucleons, is checked to be similar to the {sigma} meson exchange.
Magnetic Resonance Imaging (MRI) -- Head
Full Text Available ... bear denotes child-specific content. Related Articles and Media MR Angiography (MRA) Magnetic Resonance, Functional (fMRI) - Brain Head and Neck Cancer Treatment Brain Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic ...
Integrated silicon optofluidic ring resonator
Testa, G.; Huang, Y.; Sarro, P.M.; Zeni, L.; Bernini, R.
2010-01-01
The feasibility of an integrated silicon optofluidic ring resonator is demonstrated. Liquid core antiresonant reflecting optical waveguides are used to realize a rectangular ring resonator with a multimode interference liquid core coupler between the ring and the bus waveguide. In this configuration
Burkert, Volker D
2016-01-01
Recent results of meson photo-production at the existing electron machines with polarized real photon beams and the measurement of polarization observables of the final state baryons have provided high precision data that led to the discovery of new excited nucleon and $\\Delta$ states using multi-channel partial wave analyses procedures. The internal structure of several prominent excited states has been revealed employing meson electroproduction processes. On the theoretical front, lattice QCD is now predicting the baryon spectrum with very similar characteristics as the constituent quark model, and continuum QCD, such as is represented in the Dyson-Schwinger Equations approach and in light front relativistic quark models, describes the non-perturbative behavior of resonance excitations at photon virtuality of $Q^2 > 1.5GeV^2$. In this talk I discuss the need to continue a vigorous program of nucleon spectroscopy and the study of the internal structure of excited states as a way to reveal the effective degre...
Burkert, Volker D.
2016-10-01
Recent results of meson photo-production at the existing electron machines with polarized real photon beams and the measurement of polarization observables of the final state baryons have provided high precision data that led to the discovery of new excited nucleon and Δ states using multi-channel partial wave analyses procedures. The internal structure of several prominent excited states has been revealed employing meson electroproduction processes. On the theoretical front, lattice QCD is now predicting the baryon spectrum with very similar characteristics as the constituent quark model, and continuum QCD, such as is represented in the Dyson-Schwinger equations approach and in light front relativistic quark models, describes the non-perturbative behavior of resonance excitations at photon virtuality of Q^2 > 1.5 GeV^2. In this talk I discuss the need to continue a vigorous program of nucleon spectroscopy and the study of the internal structure of excited states as a way to reveal the effective degrees of freedom underlying the excited states and their dependence on the distance scale probed.
Tunable Micro- and Nanomechanical Resonators
Zhang, Wen-Ming; Hu, Kai-Ming; Peng, Zhi-Ke; Meng, Guang
2015-01-01
Advances in micro- and nanofabrication technologies have enabled the development of novel micro- and nanomechanical resonators which have attracted significant attention due to their fascinating physical properties and growing potential applications. In this review, we have presented a brief overview of the resonance behavior and frequency tuning principles by varying either the mass or the stiffness of resonators. The progress in micro- and nanomechanical resonators using the tuning electrode, tuning fork, and suspended channel structures and made of graphene have been reviewed. We have also highlighted some major influencing factors such as large-amplitude effect, surface effect and fluid effect on the performances of resonators. More specifically, we have addressed the effects of axial stress/strain, residual surface stress and adsorption-induced surface stress on the sensing and detection applications and discussed the current challenges. We have significantly focused on the active and passive frequency tuning methods and techniques for micro- and nanomechanical resonator applications. On one hand, we have comprehensively evaluated the advantages and disadvantages of each strategy, including active methods such as electrothermal, electrostatic, piezoelectrical, dielectric, magnetomotive, photothermal, mode-coupling as well as tension-based tuning mechanisms, and passive techniques such as post-fabrication and post-packaging tuning processes. On the other hand, the tuning capability and challenges to integrate reliable and customizable frequency tuning methods have been addressed. We have additionally concluded with a discussion of important future directions for further tunable micro- and nanomechanical resonators. PMID:26501294
Tunable Micro- and Nanomechanical Resonators
Directory of Open Access Journals (Sweden)
Wen-Ming Zhang
2015-10-01
Full Text Available Advances in micro- and nanofabrication technologies have enabled the development of novel micro- and nanomechanical resonators which have attracted significant attention due to their fascinating physical properties and growing potential applications. In this review, we have presented a brief overview of the resonance behavior and frequency tuning principles by varying either the mass or the stiffness of resonators. The progress in micro- and nanomechanical resonators using the tuning electrode, tuning fork, and suspended channel structures and made of graphene have been reviewed. We have also highlighted some major influencing factors such as large-amplitude effect, surface effect and fluid effect on the performances of resonators. More specifically, we have addressed the effects of axial stress/strain, residual surface stress and adsorption-induced surface stress on the sensing and detection applications and discussed the current challenges. We have significantly focused on the active and passive frequency tuning methods and techniques for micro- and nanomechanical resonator applications. On one hand, we have comprehensively evaluated the advantages and disadvantages of each strategy, including active methods such as electrothermal, electrostatic, piezoelectrical, dielectric, magnetomotive, photothermal, mode-coupling as well as tension-based tuning mechanisms, and passive techniques such as post-fabrication and post-packaging tuning processes. On the other hand, the tuning capability and challenges to integrate reliable and customizable frequency tuning methods have been addressed. We have additionally concluded with a discussion of important future directions for further tunable micro- and nanomechanical resonators.
Probabilistic interpretation of resonant states
Indian Academy of Sciences (India)
Naomichi Hatano; Tatsuro Kawamoto; Joshua Feinberg
2009-09-01
We provide probabilistic interpretation of resonant states. We do this by showing that the integral of the modulus square of resonance wave functions (i.e., the conventional norm) over a properly expanding spatial domain is independent of time, and therefore leads to probability conservation. This is in contrast with the conventional employment of a bi-orthogonal basis that precludes probabilistic interpretation, since wave functions of resonant states diverge exponentially in space. On the other hand, resonant states decay exponentially in time, because momentum leaks out of the central scattering area. This momentum leakage is also the reason for the spatial exponential divergence of resonant state. It is by combining the opposite temporal and spatial behaviours of resonant states that we arrive at our probabilistic interpretation of these states. The physical need to normalize resonant wave functions over an expanding spatial domain arises because particles leak out of the region which contains the potential range and escape to infinity, and one has to include them in the total count of particles.
From Autonomous Coherence Resonance to Periodically Driven Stochastic Resonance
Institute of Scientific and Technical Information of China (English)
CAO Zhou-Jian; LI Peng-Fei; HU Gang
2007-01-01
In periodically driven nonlinear stochastic systems,noise may play a role of enhancing the output periodic signal (termed as stochastic resonance or SR).While in autonomous excitable systems,noise may play a role of increasing coherent motion(termed as coherence resonance or CR).So far the topics of SR and CR have been investigated separately as two major fields of studying the active roles of noise in nonlinear systems.We find that these two topics are closely related to each other.Specifically,SR occurs in such periodically driven systems that the corresponding autonomous systems show CR.The SR with sensitive frequency dependence can be observed when the corresponding autonomous system shows CR with finite characteristic frequency.Moreover,'resonant noise' and 'resonant frequency' of SR coincide with those of CR.
Advances in magnetic resonance 5
Waugh, John S
2013-01-01
Advances in Magnetic Resonance, Volume 5 deals with the interpretation of ESR spectra and provides descriptions of experimental apparatus. This book discusses the halogen hyperfine interactions; organic radicals in single crystals; pulsed-Fourier-transform nuclear magnetic resonance spectrometer; and inhomogenizer and decoupler. The spectrometers for multiple-pulse NMR; weak collision theory of relaxation in the rotating frame; and spin Hamiltonian for the electron spin resonance of irradiated organic single crystals are also deliberated. This text likewise covers the NMR in helium three and m
Nonlinear behavior of Helmholtz resonators
Hersh, A. S.
1990-10-01
A semi-empirical fluid mechanical model has been derived to predict the nonlinear acoustic behavior of thin-walled, single-orifice Helmholtz resonators. The model assumed that the sound particle velocity field approaches the resonator in a spherically symmetric manner. The incident and cavity sound pressure fields are connected in terms of an orifice discharge coefficient and an end correction parameter whose values are determined empirically. The accuracy of the model was verified by comparing predicted with measured impedance over a wide range of sound amplitudes and frequencies for two different resonator geometries and with measurements conducted by Ingard and Ising.
Advances in magnetic resonance 1
Waugh, John S
2013-01-01
Advances in Magnetic Resonance, Volume 1, discusses developments in various areas of magnetic resonance. The subject matter ranges from original theoretical contributions through syntheses of points of view toward series of phenomena to critical and painstaking tabulations of experimental data. The book contains six chapters and begins with a discussion of the theory of relaxation processes. This is followed by separate chapters on the development of magnetic resonance techniques for studying rate processes in chemistry and the application of these techniques to various problems; the geometri
Nanoscale nonlinear PANDA ring resonator
Yupapin, Preecha
2012-01-01
Microring/nanoring resonator is an interesting device that has been widely studied and investigated by researchers from a variety of specializations. This book begins with the basic background of linear and nonlinear ring resonators. A novel design of nano device known as a PANDA ring resonator is proposed. The use of the device in the form of a PANDA in applications such as nanoelectronics, measurement, communication, sensors, optical and quantum computing, drug delivery, hybrid transistor and a new concept of electron-hole pair is discussed in detail.
Electromagnetic Excitation of Nucleon Resonances
Tiator, L; Kamalov, S S; Vanderhaeghen, M
2011-01-01
Recent progress on the extraction of electromagnetic properties of nucleon resonance excitation through pion photo- and electroproduction is reviewed. Cross section data measured at MAMI, ELSA, and CEBAF are analyzed and compared to the analysis of other groups. On this basis, we derive longitudinal and transverse transition form factors for most of the four-star nucleon resonances. Furthermore, we discuss how the transition form factors can be used to obtain empirical transverse charge densities. Contour plots of the thus derived densities are shown for the Delta, Roper, S11, and D13 nucleon resonances.
Sound-resonance hydrogen sensor
Dong, Shuxiang; Bai, Feiming; Li, Jiefang; Viehland, Dwight D.
2003-01-01
A hydrogen sensor is reported in which a small piezoelectric-sound-resonance-cavity (PSRC) is used as the sensing element. Detection utilizes sound resonance and acoustic property differences between H-2 and air as a sensing mechanism. Changes in H-2 concentration result in a shift of the sound-resonance state of the PSRC. Preliminary experiments have demonstrated a sensitivity limit of 8 ppm, a fast response time similar to1.5 second, and detection capabilities over a broad concentration ran...
Advances in magnetic resonance 9
Waugh, John S
2013-01-01
Advances in Magnetic Resonance, Volume 9 describes the magnetic resonance in split constants and dipolar relaxation. This book discusses the temperature-dependent splitting constants in the ESR spectra of organic free radicals; temperature-dependent splittings in ion pairs; and magnetic resonance induced by electrons. The electron impact excitation of atoms and molecules; intramolecular dipolar relaxation in multi-spin systems; and dipolar cross-correlation problem are also elaborated. This text likewise covers the NMR studies of molecules oriented in thermotropic liquid crystals and diffusion
Single-resonator double-negative metamaterial
Warne, Larry K.; Basilio, Lorena I.; Langston, William L.; Johnson, William A.; Ihlefeld, Jon; Ginn, III, James C.; Clem, Paul G.; Sinclair, Michael B.
2016-06-21
Resonances can be tuned in dielectric resonators in order to construct single-resonator, negative-index metamaterials. For example, high-contrast inclusions in the form of metallic dipoles can be used to shift the first electric resonance down (in frequency) to the first magnetic resonance, or alternatively, air splits can be used to shift the first magnetic resonance up (in frequency) near the first electric resonance. Degenerate dielectric designs become especially useful in infrared- or visible-frequency applications where the resonator sizes associated with the lack of high-permittivity materials can become of sufficient size to enable propagation of higher-order lattice modes in the resulting medium.
Intraoperative magnetic resonance imaging.
Hall, Walter A; Truwit, Charles L
2011-01-01
Neurosurgeons have become reliant on image-guidance to perform safe and successful surgery both time-efficiently and cost-effectively. Neuronavigation typically involves either rigid (frame-based) or skull-mounted (frameless) stereotactic guidance derived from computed tomography (CT) or magnetic resonance imaging (MRI) that is obtained days or immediately before the planned surgical procedure. These systems do not accommodate for brain shift that is unavoidable once the cranium is opened and cerebrospinal fluid is lost. Intraoperative MRI (ioMRI) systems ranging in strength from 0.12 to 3 Tesla (T) have been developed in part because they afford neurosurgeons the opportunity to accommodate for brain shift during surgery. Other distinct advantages of ioMRI include the excellent soft tissue discrimination, the ability to view the surgical site in three dimensions, and the ability to "see" tumor beyond the surface visualization of the surgeon's eye, either with or without a surgical microscope. The enhanced ability to view the tumor being biopsied or resected allows the surgeon to choose a safe surgical corridor that avoids critical structures, maximizes the extent of the tumor resection, and confirms that an intraoperative hemorrhage has not resulted from surgery. Although all ioMRI systems allow for basic T1- and T2-weighted imaging, only high-field (>1.5 T) MRI systems are capable of MR spectroscopy (MRS), MR angiography (MRA), MR venography (MRV), diffusion-weighted imaging (DWI), and brain activation studies. By identifying vascular structures with MRA and MRV, it may be possible to prevent their inadvertent injury during surgery. Biopsying those areas of elevated phosphocholine on MRS may improve the diagnostic yield for brain biopsy. Mapping out eloquent brain function may influence the surgical path to a tumor being resected or biopsied. The optimal field strength for an ioMRI-guided surgical system and the best configuration for that system are as yet
Cardiovascular Magnetic Resonance Imaging
Pelc, Norbert
2000-03-01
Cardiovascular diseases are a major source of morbidity and mortality in the United States. Early detection of disease can often be used to improved outcomes, either through direct interventions (e.g. surgical corrections) or by causing the patient to modify his or her behavior (e.g. smoking cessation or dietary changes). Ideally, the detection process should be noninvasive (i.e. it should not be associated with significant risk). Magnetic Resonance Imaging (MRI) refers to the formation of images by localizing NMR signals, typically from protons in the body. As in other applications of NMR, a homogeneous static magnetic field ( ~0.5 to 4 T) is used to create ``longitudinal" magnetization. A magnetic field rotating at the Larmor frequency (proportional to the static field) excites spins, converting longitudinal magnetization to ``transverse" magnetization and generating a signal. Localization is performed using pulsed gradients in the static field. MRI can produce images of 2-D slices, 3-D volumes, time-resolved images of pseudo-periodic phenomena such as heart function, and even real-time imaging. It is also possible to acquire spatially localized NMR spectra. MRI has a number of advantages, but perhaps the most fundamental is the richness of the contrast mechanisms. Tissues can be differentiated by differences in proton density, NMR properties, and even flow or motion. We also have the ability to introduce substances that alter NMR signals. These contrast agents can be used to enhance vascular structures and measure perfusion. Cardiovascular MRI allows the reliable diagnosis of important conditions. It is possible to image the blood vessel tree, quantitate flow and perfusion, and image cardiac contraction. Fundamentally, the power of MRI as a diagnostic tool stems from the richness of the contrast mechanisms and the flexibility in control of imaging parameters.
Magnetic Resonance Imaging (MRI) -- Head
Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... Brain Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to ...
Controlling Metamaterial Resonances with Light
Chakrabarti, Sangeeta; Wanare, Harshawardhan
2010-01-01
We investigate the use of coherent optical fields as a means of dynamically controlling the resonant behaviour of a variety of composite metamaterials, wherein the metamaterial structures are embedded in a dispersive dielectric medium. Control and switching is implemented by coherently driving the resonant permittivity of the embedding medium by applied optical radiation. The effect of embedding Split ring resonators (SRR) in a frequency- dispersive medium with Lorentz-like dispersion or with dispersion engineered by electromagnetic induced transparency (EIT), is manifested in the splitting of the negative permeability band, the modified (frequency-dependent) filling fractions and dissipation factors. The modified material parameters are strongly linked to the resonant frequencies of the medium, while for an embedding medium exhibiting EIT, also to the strength and detuning of the control field. The robustness of control against the deleterious influence of dissipation associated with the metallic structures ...
Magnetic resonance imaging the basics
Constantinides, Christakis
2014-01-01
Magnetic resonance imaging (MRI) is a rapidly developing field in basic applied science and clinical practice. Research efforts in this area have already been recognized with five Nobel prizes awarded to seven Nobel laureates in the past 70 years. Based on courses taught at The Johns Hopkins University, Magnetic Resonance Imaging: The Basics provides a solid introduction to this powerful technology. The book begins with a general description of the phenomenon of magnetic resonance and a brief summary of Fourier transformations in two dimensions. It examines the fundamental principles of physics for nuclear magnetic resonance (NMR) signal formation and image construction and provides a detailed explanation of the mathematical formulation of MRI. Numerous image quantitative indices are discussed, including (among others) signal, noise, signal-to-noise, contrast, and resolution. The second part of the book examines the hardware and electronics of an MRI scanner and the typical measurements and simulations of m...
Nested trampoline resonators for optomechanics
Energy Technology Data Exchange (ETDEWEB)
Weaver, M. J., E-mail: mweaver@physics.ucsb.edu; Pepper, B.; Luna, F.; Perock, B. [Department of Physics, University of California, Santa Barbara, California 93106 (United States); Buters, F. M.; Eerkens, H. J.; Welker, G.; Heeck, K.; Man, S. de [Huygens-Kamerlingh Onnes Laboratorium, Universiteit Leiden, 2333 CA Leiden (Netherlands); Bouwmeester, D. [Department of Physics, University of California, Santa Barbara, California 93106 (United States); Huygens-Kamerlingh Onnes Laboratorium, Universiteit Leiden, 2333 CA Leiden (Netherlands)
2016-01-18
Two major challenges in the development of optomechanical devices are achieving a low mechanical and optical loss rate and vibration isolation from the environment. We address both issues by fabricating trampoline resonators made from low pressure chemical vapor deposition Si{sub 3}N{sub 4} with a distributed Bragg reflector mirror. We design a nested double resonator structure with 80 dB of mechanical isolation from the mounting surface at the inner resonator frequency, and we demonstrate up to 45 dB of isolation at lower frequencies in agreement with the design. We reliably fabricate devices with mechanical quality factors of around 400 000 at room temperature. In addition, these devices were used to form optical cavities with finesse up to 181 000 ± 1000. These promising parameters will enable experiments in the quantum regime with macroscopic mechanical resonators.
Calligraphic Poling for WGM Resonators
Mohageg, Makan; Strekalov, Dmitry; Savchenkov, Anatoliy; Matsko, Andrey; Ilchenko, Vladimir; Maleki, Lute
2007-01-01
By engineering the geometry of a nonlinear optical crystal, the effective efficiency of all nonlinear optical oscillations can be increased dramatically. Specifically, sphere and disk shaped crystal resonators have been used to demonstrate nonlinear optical oscillations at sub-milliwatt input power when cs light propagates in a Whispering Gallery Mode (WGM) of such a resonant cavity. in terms of both device production and experimentation in quantum optics, some nonlinear optical effects with naturally high efficiency can occult the desired nonlinear scattering process. the structure to the crystal resonator. In this paper, I will discuss a new method for generating poling structures in ferroelectric crystal resonators called calligraphic poling. The details of the poling apparatus, experimental results and speculation on future applications will be discussed.
Children's (Pediatric) Magnetic Resonance Imaging
Full Text Available ... resonance imaging (MRI) uses a powerful magnetic field, radio waves and a computer to produce detailed pictures ... medical conditions. MRI uses a powerful magnetic field, radio frequency pulses and a computer to produce detailed ...
Superhumps, resonances and accretion discs
Energy Technology Data Exchange (ETDEWEB)
Whitehurst, R.; King, A. (Leicester Univ. (UK). Dept. of Astronomy)
1991-03-01
The structure of accretion discs within binary systems is shown to be influenced by the excitation of resonances within the disc. Of particular importance is that near the 3:1 commensurability with the stars' orbit. This can be used to explain the superhump phenomenon of SU Ursae Majoris dwarf novae in superoutburst. This resonance can only appear for mass ratios which satisfy M{sub 2}/M{sub 1} < {approx equal} 0.25-0.33: for larger mass ratios the available resonances are weaker and of the wrong form to produce the superhump phenomenon. The mass-transfer stream is shown to be an important contributor to the growth rate of the resonance. (author).
Nested Trampoline Resonators for Optomechanics
Weaver, Matthew J; Luna, Fernando; Buters, Frank M; Eerkens, Hedwig J; Welker, Gesa; Perock, Blaise; Heeck, Kier; de Man, Sven; Bouwmeester, Dirk
2015-01-01
Two major challenges in the development of optomechanical devices are achieving a low mechanical and optical loss rate and vibration isolation from the environment. We address both issues by fabricating novel trampoline resonators made from low pressure chemical vapor deposition (LPCVD) Si$_3$N$_4$ with a distributed bragg reflector (DBR) mirror. We construct a nested double resonator structure that generates approximately 80 dB of mechanical isolation from the mounting surface, eliminating the strong mounting dependence of the quality factor observed with single resonators. With the consistency provided by this isolation scheme we reliably fabricate devices with mechanical quality factors of around 400,000 at room temperature. In addition these devices were used to form optical cavities with finesse up to 181,000 $\\pm$ 1,000. These promising parameters will enable experiments in the quantum regime with macroscopic mechanical resonators.
Magnetic Resonance Imaging (MRI) -- Head
Full Text Available ... MRI of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive ... of page What are some common uses of the procedure? MR imaging of the head is performed ...
Ion Cyclotron Resonance Facility (ICR)
Federal Laboratory Consortium — his facility is charged with developing and exploiting the unique capabilities of Fourier Transform Ion Cyclotron Resonance (FT-ICR) mass spectrometry, and leads the...
Magnetic Resonance Imaging (MRI) -- Head
... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... that magnetic resonance imaging harms the fetus, pregnant women usually are advised not to have an MRI ...
Magnetic Resonance Imaging (MRI) -- Head
Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... that magnetic resonance imaging harms the fetus, pregnant women usually are advised not to have an MRI ...
Nucleon Resonances in Kaon Photoproduction
Bennhold, C; Waluyo, A; Haberzettl, H; Penner, G; Feuster, T; Mosel, U
1999-01-01
Nucleon resonances are investigated through the electromagnetic production of K-mesons. We study the kaon photoproduction process at tree-level and compare to a recently developed unitary K-matrix approach. Employing hadronic form factors along with the proper gauge prescription yields suppression of the Born terms and leads a resonance dominated process for both K-Lambda and K-Sigma photoproduction. Using new SAPHIR data we find the K+-Lambda photoproduction to be dominated by the S11(1650) at threshold, with additional contributions from the P11(1710) and P13(1720) states. The K-Sigma channel couples to a cluster of Delta resonances around W = 1900 MeV. We briefly discuss some tantalizing evidence for a missing D13 resonance around 1900 MeV with a strong branching ratio into KLambda channel.
Nanocatalytic resonance scattering spectral analysis
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
The resonance scattering spectral technique has been established using the synchronous scanning technique on spectrofluorometry.Because of its advantages of simplicity,rapidity and sensitivity,it has been widely applied to analyses of proteins,nucleic acids and inorganic ions.This paper summarizes the application of immunonanogold and aptamer modified nanogold(AptAu) catalytic resonance scattering spectral technique in combination with the work of our group,citing 53 references.
Advances in magnetic resonance 4
Waugh, John S
2013-01-01
Advances in Magnetic Resonance, Volume 4 deals with the relaxation, irradiation, and other dynamical effects that is specific to systems having resolved structure in their magnetic resonance spectra. This book discusses the anisotropic rotation of molecules in liquids by NMR quadrupolar relaxation; rotational diffusion constants; alternating linewidth effect; and theoretical formulations of the problem. The line shapes in high-resolution NMR; matrix representations of the equations of motion; matrix representations of the equations of motion; and intramolecular hydrogen bonds are also delibera
Electromagnetic properties of baryon resonances
Tiator, Lothar
2012-01-01
Longitudinal and transverse transition form factors for most of the four-star nucleon resonances have been obtained from high-quality cross section data and polarization observables measured at MAMI, ELSA, BATES, GRAAL and CEBAF. As an application, we further show how the transition form factors can be used to obtain empirical transverse charge densities. Contour plots of the thus derived densities are shown and compared for the Roper and S11 nucleon resonances.
Maltz, Jonathan
2016-01-01
A quantum mechanical formulation of de Sitter cosmological spacetimes still eludes string theory. In this paper we conjecture a potentially rigorous framework in which the status of de Sitter space is the same as that of a resonance in a scattering process. We conjecture that transition amplitudes between certain states with asymptotically supersymmetric flat vacua contain resonant poles characteristic meta-stable intermediate states. A calculation employing constrained instantons illustrates this idea.
Advances in magnetic resonance 2
Waugh, John S
2013-01-01
Advances in Magnetic Resonance, Volume 2, features a mixture of experimental and theoretical contributions. The book contains four chapters and begins with an ambitious and general treatment of the problem of signal-to-noise ratio in magnetic resonance. This is followed by separate chapters on the interpretation of nuclear relaxation in fluids, with special reference to hydrogen; and various aspects of molecular theory of importance in NMR.
Micro-machined resonator oscillator
Koehler, Dale R.; Sniegowski, Jeffry J.; Bivens, Hugh M.; Wessendorf, Kurt O.
1994-01-01
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.
Universal formalism of Fano resonance
Energy Technology Data Exchange (ETDEWEB)
Huang, Liang [School of Physical Science and Technology and Key Laboratory for Magnetism and Magnetic Materials of MOE, Lanzhou University, Lanzhou, Gansu 730000 (China); Lai, Ying-Cheng [School of Electrical, Computer, and Energy Engineering, Arizona State University, Tempe, Arizona 85287 (United States); Department of Physics, Arizona State University, Tempe, Arizona 85287 (United States); Institute for Complex Systems and Mathematical Biology, King’s College, University of Aberdeen, Aberdeen AB24 3UE (United Kingdom); Luo, Hong-Gang [School of Physical Science and Technology and Key Laboratory for Magnetism and Magnetic Materials of MOE, Lanzhou University, Lanzhou, Gansu 730000 (China); Beijing Computational Science Research Center, Beijing 100084 (China); Grebogi, Celso [Institute for Complex Systems and Mathematical Biology, King’s College, University of Aberdeen, Aberdeen AB24 3UE (United Kingdom)
2015-01-15
The phenomenon of Fano resonance is ubiquitous in a large variety of wave scattering systems, where the resonance profile is typically asymmetric. Whether the parameter characterizing the asymmetry should be complex or real is an issue of great experimental interest. Using coherent quantum transport as a paradigm and taking into account of the collective contribution from all available scattering channels, we derive a universal formula for the Fano-resonance profile. We show that our formula bridges naturally the traditional Fano formulas with complex and real asymmetry parameters, indicating that the two types of formulas are fundamentally equivalent (except for an offset). The connection also reveals a clear footprint for the conductance resonance during a dephasing process. Therefore, the emergence of complex asymmetric parameter when fitting with experimental data needs to be properly interpreted. Furthermore, we have provided a theory for the width of the resonance, which relates explicitly the width to the degree of localization of the close-by eigenstates and the corresponding coupling matrices or the self-energies caused by the leads. Our work not only resolves the issue about the nature of the asymmetry parameter, but also provides deeper physical insights into the origin of Fano resonance. Since the only assumption in our treatment is that the transport can be described by the Green’s function formalism, our results are also valid for broad disciplines including scattering problems of electromagnetic waves, acoustics, and seismology.
Universal formalism of Fano resonance
Directory of Open Access Journals (Sweden)
Liang Huang
2015-01-01
Full Text Available The phenomenon of Fano resonance is ubiquitous in a large variety of wave scattering systems, where the resonance profile is typically asymmetric. Whether the parameter characterizing the asymmetry should be complex or real is an issue of great experimental interest. Using coherent quantum transport as a paradigm and taking into account of the collective contribution from all available scattering channels, we derive a universal formula for the Fano-resonance profile. We show that our formula bridges naturally the traditional Fano formulas with complex and real asymmetry parameters, indicating that the two types of formulas are fundamentally equivalent (except for an offset. The connection also reveals a clear footprint for the conductance resonance during a dephasing process. Therefore, the emergence of complex asymmetric parameter when fitting with experimental data needs to be properly interpreted. Furthermore, we have provided a theory for the width of the resonance, which relates explicitly the width to the degree of localization of the close-by eigenstates and the corresponding coupling matrices or the self-energies caused by the leads. Our work not only resolves the issue about the nature of the asymmetry parameter, but also provides deeper physical insights into the origin of Fano resonance. Since the only assumption in our treatment is that the transport can be described by the Green’s function formalism, our results are also valid for broad disciplines including scattering problems of electromagnetic waves, acoustics, and seismology.
Mass detection using capacitive resonant silicon resonator employing LC resonant circuit technique.
Kim, Sang-Jin; Ono, Takahito; Esashi, Masayoshi
2007-08-01
Capacitive resonant mass sensing using a single-crystalline silicon resonator with an electrical LC oscillator was demonstrated in ambient atmosphere. Using capacitive detection method, the detectable minimum mass of 1 x 10(-14) g was obtained in the self-oscillation of cantilever with a thickness of 250 nm. The noise amplitude of the sensor output corresponds to a vibration amplitude of 0.05 nm(Hz)(0.5) in the frequency domain compared with the actuation signal, which is equivalent to the detectable minimum capacitance variation of 2.4 x 10(-21) F. Using the capacitive detection method, mass/stress induced resonance frequency shift due to the adsorption of ethanol and moist vapor in a pure N(2) gas as a carrier is successfully demonstrated. These results show the high potential of capacitive silicon resonator for high mass/stress-sensitive sensor.
Study on resonance frequency of thermoacoustic resonance pipes
Institute of Scientific and Technical Information of China (English)
FAN Li; WANG Benren; JIN Tao; ZHANG Shuyi
2005-01-01
For calculating the resonance frequency of practical resonance pipes more precisely, two methods are presented, which are the method of acoustic pressure simulation and the method of minimum point of standing wave. Both methods are based on the theoretical simulation of the acoustic pressure distribution in the pipe and the relation between the minimum point position of the standing wave and the acoustic impedances of the pipe terminations.It is demonstrated that both methods can calculate the resonance frequency of a pipe more precisely by considering the effect of the acoustic resistances of both terminations of the pipe.Therefore both methods presented are more useful in acoustic research fields in which the resonance frequency of a pipe must be controlled strictly. In addition, both methods can get the same calculation results despite of their different ways. The method of the minimum point of standing wave is more convenient, nevertheless the method of acoustic pressure simulation can derive the resonance frequency and the distribution of the acoustic pressure in the pipe simultaneously.
Transmission Line Resonator Segmented with Series Capacitors
DEFF Research Database (Denmark)
Zhurbenko, Vitaliy; Boer, Vincent; Petersen, Esben Thade
2016-01-01
Transmission line resonators are often used as coils in high field MRI. Due to distributed nature of such resonators, coils based on them produce inhomogeneous field. This work investigates application of series capacitors to improve field homogeneity along the resonator. The equations for optimal...... values of evenly distributed capacitors are presented. The performances of the segmented resonator and a regular transmission line resonator are compared....
Structural Colors from Fano Resonances
Shen, Yichen; Wang, Imbert; Stelmakh, Veronika; Joannopoulos, John D; Soljacic, Marin
2014-01-01
Structural coloration is an interference phenomenon where colors emerge when visible light interacts with nanoscopically structured material, and has recently become a most interesting scientific and engineering topic. However, current structural color generation mechanisms either require thick (compared to the wavelength) structures or lack dynamic tunability. This report proposes a new structural color generation mechanism, that produces colors by the Fano resonance effect on thin photonic crystal slab. We experimentally realize the proposed idea by fabricating the samples that show resonance-induced colors with weak dependence on the viewing angle. Finally, we show that the resonance-induced colors can be dynamically tuned by stretching the photonic crystal slab fabricated on an elastic substrate.
Holographic Kondo and Fano Resonances
Erdmenger, Johanna; O'Bannon, Andy; Papadimitriou, Ioannis; Probst, Jonas; Wu, Jackson M S
2016-01-01
We use holography to study a $(1+1)$-dimensional Conformal Field Theory (CFT) coupled to an impurity. The CFT is an $SU(N)$ gauge theory at large $N$, with strong gauge interactions. The impurity is an $SU(N)$ spin. We trigger an impurity Renormalization Group (RG) flow via a Kondo coupling. The Kondo effect occurs only below the critical temperature of a large-$N$ mean-field transition. We show that at all temperatures $T$, spectral functions of certain bosonic operators exhibit a Fano resonance, which in the low-$T$ phase is a large-$N$ manifestation of the Kondo resonance. Such Fano resonances are characteristic features of RG flows between $(0+1)$-dimensional fixed points, and are thus distinct from those observed for example in quantum dots.
Viscoelastic coupling of nanoelectromechanical resonators.
Energy Technology Data Exchange (ETDEWEB)
Simonson, Robert Joseph; Staton, Alan W.
2009-09-01
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.
Resonance Ionization Laser Ion Sources
Marsh, B
2013-01-01
The application of the technique of laser resonance ionization to the production of singly charged ions at radioactive ion beam facilities is discussed. The ability to combine high efficiency and element selectivity makes a resonance ionization laser ion source (RILIS) an important component of many radioactive ion beam facilities. At CERN, for example, the RILIS is the most commonly used ion source of the ISOLDE facility, with a yearly operating time of up to 3000 hours. For some isotopes the RILIS can also be used as a fast and sensitive laser spectroscopy tool, provided that the spectral resolution is sufficiently high to reveal the influence of nuclear structure on the atomic spectra. This enables the study of nuclear properties of isotopes with production rates even lower than one ion per second and, in some cases, enables isomer selective ionization. The solutions available for the implementation of resonance laser ionization at radioactive ion beam facilities are summarized. Aspects such as the laser r...
A MEMS diamond hemispherical resonator
Bernstein, J. J.; Bancu, M. G.; Cook, E. H.; Chaparala, M. V.; Teynor, W. A.; Weinberg, M. S.
2013-12-01
In this paper we report the fabrication of hemispherical polycrystalline diamond resonators fabricated on a novel high-temperature glass substrate. The hemispherical resonator gyroscope is one of the most accurate and rugged of the mechanical gyroscopes, and can be operated in either rate or whole-angle mode due to its high degree of symmetry. A fabrication sequence for creating extremely symmetric 3D MEMS hemispheres is presented. Mode shapes and frequencies obtained with a laser vibrometer are shown, as well as curves of Q versus pressure, and the dependence of frequency on anchor size. Fundamental mode frequency matching to gyroscope operation in whole-angle mode.
Kartashov, Yaroslav V; Vysloukh, Victor A; Torner, Lluis
2014-07-01
We introduce Bloch-wave beatings in arrays of multimode periodically bent waveguides with a transverse refractive index gradient. The new phenomenon manifests itself in the periodic drastic increase of the amplitude of the Bloch oscillations that accompanies resonant conversion of modes guided by the individual waveguides. The Bloch-wave beatings are found to be most pronounced when the length of the resonant mode conversion substantially exceeds the longitudinal period of the Bloch oscillations. The beating frequency decreases when the amplitude of waveguide bending decreases, while the beating amplitude is restricted by the amplitude of the Bloch oscillations that emerge from the second allowed band of the Floquet-Bloch lattice spectrum.
Kartashov, Yaroslav V; Torner, Lluis
2014-01-01
We introduce Bloch-wave beatings in arrays of multimode periodically bent waveguides with a transverse refractive index gradient. The new phenomenon manifests itself in the periodic drastic increase of the amplitude of the Bloch oscillations that accompanies resonant conversion of modes guided by the individual waveguides. The Bloch-wave beatings are found to be most pronounced when the length of the resonant mode conversion substantially exceeds the longitudinal period of the Bloch oscillations. The beating frequency decreases when the amplitude of waveguide bending decreases, while the beating amplitude is restricted by the amplitude of the Bloch oscillations that emerge from the second allowed band of the Floquet-Bloch lattice spectrum.
Coupled-resonator optical waveguides
DEFF Research Database (Denmark)
Raza, Søren; Grgic, Jure; Pedersen, Jesper Goor;
2010-01-01
Coupled-resonator optical waveguides hold potential for slow-light propagation of optical pulses. The dispersion properties may adequately be analyzed within the framework of coupled-mode theory. We extend the standard coupled-mode theory for such structures to also include complex......-valued parameters which allows us to analyze the dispersion properties also in presence of finite Q factors for the coupled resonator states. Near the band-edge the group velocity saturates at a finite value vg/c µ p1/Q while in the band center, the group velocity is unaffected by a finite Q factor as compared...
Parametric resonance in ideal magnetohydrodynamics
Zaqarashvili
2000-08-01
We show that an external nonelectromagnetic periodic inhomogeneous force sets up a parametric resonance in an ideal magnetohydrodynamics. Alfven waves with certain wavelengths grow exponentially in amplitude. Nonlinear interaction between the resonant harmonics produces the long-term modulation of amplitudes. The mechanism of the energy transformation from an external nonelectromagnetic force to magnetic oscillations of the system presented here can be used in understanding the physical background of the gravitational action on the magnetized medium. Future application of this theory to several astrophysical problems is briefly discussed.
magnetic resonance imaging,etc.
Institute of Scientific and Technical Information of China (English)
张福基
1998-01-01
magnetic resonance imaging n.[1984] a noninvasive diagnostic technique that produces computerized images of internal body tissues and is based on nuclear magnetic resonance of atoms within he body induced by the application of radio waves磁共振成像(指一种非侵害 性诊断技术,能生成内部身体组织的计算机化影像,其依据是应用无线电波 感生体内原子并使之产磁共振)
Resonance modes in optical fibres
Institute of Scientific and Technical Information of China (English)
余寿绵; 余恬
2002-01-01
The weakly nonlinear boundary value problem of wave propagation in an optical fibre (for the transverse electric mode, for example) is formulated and a modified linear solution is obtained. It is shown that a self-consistent theory of fibre optics should be weakly nonlinear. The mode of critical refraction that does not exist in the linear theory is obtained, showing that it is a mode consisting of resonance modes. It is shown that the signal carriers in a long fibre are of resonance modes, not normal modes. Some experimental data are given for comparison with the theoretical predictions, and the agreement seems satisfactory.
Resonances in -light nucleus systems
Indian Academy of Sciences (India)
K P Khemchandani; N G Kelkar; M Nowakowski; B K Jain
2006-04-01
We locate resonances in -light nucleus elastic scattering using the time delay method. We solve few-body equations within the finite rank approximation in order to calculate the -matrices and hence the time delay for the - 3He and - 4He systems. We find a resonance very close to the threshold in - 3 He elastic scattering, at about 0.5 MeV above threshold with a width of ∼ 2 MeV. The calculations also hint at the presence of sub-threshold states in both the cases.
Advances in magnetic resonance 8
Waugh, John S
2013-01-01
Advances in Magnetic Resonance, Volume 8 describes the magnetic resonance in spin polarization and saturation transfer. This book discusses the theory of chemically induced dynamic spin polarization; basic results for the radical-pair mechanism; and optical spin polarization in molecular crystals. The theory of optical electronic polarization (OEP); NMR in flowing systems; and applications of NMR in a flowing liquid are also elaborated. This text likewise covers the saturation transfer spectroscopy; studies of spin labels in the intermediate and fast motion regions; and spin-density matrix and
Controlling a diatomic shape resonance with non-resonant light
Aganoglu, Ruzin; Friedrich, Bretislav; González-Férez, Rosario; Koch, Christiane P
2011-01-01
A (diatomic) shape resonance is a metastable state of a pair of colliding atoms quasi-bound by the centrifugal barrier imposed by the angular momentum involved in the collision. The temporary trapping of the atoms' scattering wavefunction corresponds to an enhanced atom pair density at low interatomic separations. This leads to larger overlap of the wavefunctions involved in a molecule formation process such as photoassociation, rendering the process more efficient. However, for an ensemble of atoms, the atom pair density will only be enhanced if the energy of the resonance comes close to the temperature of the atomic ensemble. Herein we explore the possibility of controlling the energy of a shape resonance by shifting it toward the temperature of atoms confined in a trap. The shifts are imparted by the interaction of non-resonant light with the anisotropic polarizability of the atom pair, which affects both the centrifugal barrier and the pair's rotational and vibrational levels. We find that at laser intens...
Quantifying resonant and near-resonant interactions in rotating turbulence
di Leoni, P Clark
2016-01-01
Nonlinear triadic interactions are at the heart of our understanding of turbulence. In flows where waves are present modes must not only be in a triad to interact, but their frequencies must also satisfy an extra condition: the interactions that dominate the energy transfer are expected to be resonant. We derive equations that allow direct measurement of the actual degree of resonance of each triad in a turbulent flow. We then apply the method to the case of rotating turbulence, where eddies coexist with inertial waves. We show that for a range of wave numbers, resonant and near-resonant triads are dominant, the latter allowing a transfer of net energy towards two-dimensional modes that would be inaccessible otherwise. The results are in good agreement with approximations often done in theories of rotating turbulence, and with the mechanism of parametric instability proposed to explain the development of anisotropy in such flows. We also observe that, at least for the moderate Rossby numbers studied here, mar...
Resonant interaction modified by the atomic environment
Energy Technology Data Exchange (ETDEWEB)
Sainz, I; Klimov, A B; Chumakov, S M [Departamento de Fisica, Universidad de Guadalajara, Revolucion 1500, 44410, Guadalajara, Jal. (Mexico)
2003-04-01
The dynamics of a resonant atom interacting with a quantum cavity field in the presence of many off-resonant atoms is studied. In the framework of the effective Hamiltonian approach we show that the results of elimination of non-resonant transitions are (a) a dynamical Stark shift of the field frequency, dependent on the populations of non-resonant atoms, (b) dependence of the coupling constant between the resonant atom and the field on the populations of non-resonant atoms, and (c) an effective dipole-dipole interaction between non-resonant atoms. Two effects (the coherent influence and dephasing) of the off-resonant environment on the dynamics of the resonant atom are discussed.
Resonance, Multi-resonance, and Reverse-resonance Induced by Multiplicative Dichotomous Noise
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
A constant-potential system driven by multiplicative dichotomous noise and subject to an input oscillatory signal is investigated. Two phenomena of stochastic resonance are observed. One is the response as a function of the noise's parameters; the other is that as a function of the input signal frequency. A phenomenon of multi-resonance (there are three or four peaks) is found for the response as a function of a parameter of the noise. A phenomenon of reverse-resonance is found, for which the response of the system to the signal can be weakened by the presence of the noise (there is an optimal minimum). These results help in studies of the systems with multiplicative dichotomous noise, such as the semiconductor, the proteins motor, the chemical reaction, and so on.
Resonance in Bottles with Different Shapes
Directory of Open Access Journals (Sweden)
Amy Elliott
2012-01-01
Full Text Available The Helmholtz Resonance equation derived in the 1800’s describes the nature of resonance in narrow-necked vessels, known as Helmholtz Resonators. It is commonly accepted that when air is blown across the opening of a bottle, the resonance can be modeled by the Helmholtz equation. Resonance was studied in two differently shaped bottles as the volume of the air cavity was varied. It was found that resonance in one of the bottles was accurately modeled by the Helmholtz equation but not in the other.
Helmholtz Resonance in a Water Bottle
Directory of Open Access Journals (Sweden)
Annirudh Balachandran
2011-01-01
Full Text Available The resonance that occurs when blowing across the top of a water bottle filled with different volumes of water was studied. It was shown that, contrary to popular belief, a water bottle is not an ideal Helmholtz resonator. Resonance in a water bottle with an extendable neck was then studied to determine how the length of the neck affects the resonance. The results showed that ideal Helmholtz resonance occurs when the neck length was in a middle range, while for no neck a standing wave resonance occurs. For a very long neck the results were inconclusive.
Meson resonances on the lattice
Energy Technology Data Exchange (ETDEWEB)
Edwards, Robert G. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2016-06-01
There has been recent, significant, advances in the determination of the meson spectrum of QCD. Current efforts have focused on the development and application of finite-volume formalisms that allow for the determination of scattering amplitudes as well as resonance behavior in coupled channel systems. I will review some of these recent developments, and demonstrate the viability of the method in meson systems
Meson Resonances from Lattice QCD
Energy Technology Data Exchange (ETDEWEB)
Edwards, Robert G. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2016-06-01
There has been recent, significant, advances in the determination of the meson spectrum of QCD. Current efforts have focused on the development and application of finite-volume formalisms that allow for the determination of scattering amplitudes as well as resonance behavior in coupled channel systems. I will review some of these recent developments, and demonstrate the viability of the method in meson systems.
Magnetic Resonance Image Wavelet Enhancer
2007-11-02
1Departamento de Ingenieria Electrica, UAM Iztapalapa, Mexico−DF, 09340, Mexico email:arog@xanum.uam.mx. Magnetic Resonance Centre, School of Physics...Number Task Number Work Unit Number Performing Organization Name(s) and Address(es) Departamento de Ingenieria Electrica, UAM Iztapalapa, Mexico-DF
Biosensing by WGM Microspherical Resonators
Directory of Open Access Journals (Sweden)
Giancarlo C. Righini
2016-06-01
Full Text Available Whispering gallery mode (WGM microresonators, thanks to their unique properties, have allowed researchers to achieve important results in both fundamental research and engineering applications. Among the various geometries, microspheres are the simplest 3D WGM resonators; the total optical loss in such resonators can be extremely low, and the resulting extraordinarily high Q values of 108–109 lead to high energy density, narrow resonant-wavelength lines and a lengthy cavity ringdown. They can also be coated in order to better control their properties or to increase their functionality. Their very high sensitivity to changes in the surrounding medium has been exploited for several sensing applications: protein adsorption, trace gas detection, impurity detection in liquids, structural health monitoring of composite materials, detection of electric fields, pressure sensing, and so on. In the present paper, after a general introduction to WGM resonators, attention is focused on spherical microresonators, either in bulk or in bubble format, to their fabrication, characterization and functionalization. The state of the art in the area of biosensing is presented, and the perspectives of further developments are discussed.
Interface losses in multimaterial resonators
DEFF Research Database (Denmark)
Villanueva, L.G.; Amato, B.; Larsen, Tom;
2014-01-01
We present an extensive study shedding light on the role of surface and bulk losses in micromechanical resonators. We fabricate thin silicon nitride membranes of different sizes and we coat them with different thicknesses of metal. We later characterize the 81 lowest out-of-plane flexural vibrati...
Algebraic model of baryon resonances
Bijker, R
1997-01-01
We discuss recent calculations of electromagnetic form factors and strong decay widths of nucleon and delta resonances. The calculations are done in a collective constituent model of the nucleon, in which the baryons are interpreted as rotations and vibrations of an oblate top.
Resonances in retrograde circumbinary discs
Nixon, Chris
2015-01-01
We analyse the interaction of an eccentric binary with a circular coplanar circumbinary disc that rotates in a retrograde sense with respect to the binary. In the circular binary case, no Lindblad resonances lie within the disc and no Lindblad resonant torques are produced, as was previously known. By analytic means, we show that when the binary orbit is eccentric, there exist components of the gravitational potential of the binary which rotate in a retrograde sense to the binary orbit and so rotate progradely with respect to this disc, allowing a resonant interaction to occur between the binary and the disc. The resulting resonant torques distinctly alter the disc response from the circular binary case. We describe results of three-dimensional hydrodynamic simulations to explore this effect and categorise the response of the disc in terms of modes whose strengths vary as a function of binary mass ratio and eccentricity. These mode strengths are weak compared to the largest mode strengths expected in the prog...
Evanescent Waves Nuclear Magnetic Resonance
DEFF Research Database (Denmark)
Halidi, El Mohamed; Nativel, Eric; Akel, Mohamad
2016-01-01
Nuclear Magnetic Resonance spectroscopy and imaging can be classified as inductive techniques working in the near- to far-field regimes. We investigate an alternative capacitive detection with the use of micrometer sized probes positioned at sub wavelength distances of the sample in order...
Children's (Pediatric) Magnetic Resonance Imaging
Full Text Available ... E-mail: Area code: Phone no: Thank you! Images × Image Gallery Radiologist prepping patient for magnetic resonance imaging ( ... address): From (your name): Your e-mail address: Personal message (optional): Bees: Wax: Notice: RadiologyInfo respects your ...
Magnetic Resonance Imaging (MRI) -- Head
Full Text Available ... E-mail: Area code: Phone no: Thank you! Images × Image Gallery Magnetic Resonance Imaging (MRI) procedure View full ... address): From (your name): Your e-mail address: Personal message (optional): Bees: Wax: Notice: RadiologyInfo respects your ...
Tuning Fano Resonances with Graphene
DEFF Research Database (Denmark)
Emani, Naresh K.; Chung, Ting-Fung; Prokopeva, Ludmila
2013-01-01
We demonstrate strong electrical control of plasmonic Fano resonances in dolmen structures using tunable interband transitions in graphene. Such graphene-plasmonic hybrid devices can have applications in light modulation and sensing. OCIS codes: (250.5403) Plasmonics; (160.4670) Optical materials...
Entropy production by resonance decays
Ochs, S; Ochs, Stefan; Heinz, Ulrich
1996-01-01
We investigate entropy production for an expanding system of particles and resonances with isospin symmetry -- in our case pions and \\rho mesons -- within the framework of relativistic kinetic theory. A cascade code to simulate the kinetic equations is developed and results for entropy production and particle spectra are presented.
Biosensing by WGM Microspherical Resonators
Righini, Giancarlo C.; Soria, Silvia
2016-01-01
Whispering gallery mode (WGM) microresonators, thanks to their unique properties, have allowed researchers to achieve important results in both fundamental research and engineering applications. Among the various geometries, microspheres are the simplest 3D WGM resonators; the total optical loss in such resonators can be extremely low, and the resulting extraordinarily high Q values of 108–109 lead to high energy density, narrow resonant-wavelength lines and a lengthy cavity ringdown. They can also be coated in order to better control their properties or to increase their functionality. Their very high sensitivity to changes in the surrounding medium has been exploited for several sensing applications: protein adsorption, trace gas detection, impurity detection in liquids, structural health monitoring of composite materials, detection of electric fields, pressure sensing, and so on. In the present paper, after a general introduction to WGM resonators, attention is focused on spherical microresonators, either in bulk or in bubble format, to their fabrication, characterization and functionalization. The state of the art in the area of biosensing is presented, and the perspectives of further developments are discussed. PMID:27322282
Children's (Pediatric) Magnetic Resonance Imaging
Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... Magnetic resonance imaging (MRI) is a noninvasive medical test that physicians use to diagnose and treat medical ...
Magnetic Resonance Imaging (MRI) -- Head
Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... Magnetic resonance imaging (MRI) is a noninvasive medical test that physicians use to diagnose and treat medical ...
Inelastic scattering in resonant tunneling
DEFF Research Database (Denmark)
Wingreen, Ned S.; Jacobsen, Karsten Wedel; Wilkins, John W.
1989-01-01
The exact resonant-tunneling transmission probability for an electron interacting with phonons is presented in the limit that the elastic coupling to the leads is independent of energy. The phonons produce transmission sidebands but do not affect the integrated transmission probability or the esc...
Composite Resonator Surface Emitting Lasers
Energy Technology Data Exchange (ETDEWEB)
FISCHER,ARTHUR J.; CHOQUETTE,KENT D.; CHOW,WENG W.; ALLERMAN,ANDREW A.; GEIB,KENT M.
2000-05-01
The authors have developed electrically-injected coupled-resonator vertical-cavity lasers and have studied their novel properties. These monolithically grown coupled-cavity structures have been fabricated with either one active and one passive cavity or with two active cavities. All devices use a selectively oxidized current aperture in the lower cavity, while a proton implant was used in the active-active structures to confine current in the top active cavity. They have demonstrated optical modulation from active-passive devices where the modulation arises from dynamic changes in the coupling between the active and passive cavities. The laser intensity can be modulated by either forward or reverse biasing the passive cavity. They have also observed Q-switched pulses from active-passive devices with pulses as short as 150 ps. A rate equation approach is used to model the Q-switched operation yielding good agreement between the experimental and theoretical pulseshape. They have designed and demonstrated the operation of active-active devices which la.se simultaneously at both longitudinal cavity resonances. Extremely large bistable regions have also been observed in the light-current curves for active-active coupled resonator devices. This bistability can be used for high contrast switching with contrast ratios as high as 100:1. Coupled-resonator vertical-cavity lasers have shown enhanced mode selectivity which has allowed devices to lase with fundamental-mode output powers as high as 5.2 mW.
Advances in magnetic and optical resonance
Warren, Warren S
1997-01-01
Since 1965, Advances in Magnetic and Optical Resonance has provided researchers with timely expositions of fundamental new developments in the theory of, experimentation with, and application of magnetic and optical resonance.
Super-Resonant Intracavity Coherent Absorption
Malara, P; Giorgini, A; Avino, S; De Natale, P; Gagliardi, G
2016-01-01
The capability of optical resonators to extend the effective radiation-matter interaction length originates from a multipass effect, hence is intrinsically limited by the resonator quality factor. Here, we show that this constraint can be overcome by combining the concepts of resonant interaction and coherent perfect absorption. We demonstrate and investigate super-resonant coherent absorption in a coupled Fabry-Perot-ring cavity structure. At the FP resonant wavelengths, the described phenomenon gives rise to split modes with a nearly-transparent peak and a peak whose transmission is exceptionally sensitive to the intracavity loss. For small losses, the effective interaction pathlength of these modes is proportional respectively to the ratio and the product of the individual finesse coefficients of the two resonators. The results presented extend the conventional definition of resonant absorption and point to a way of circumventing the technological limitations of ultrahigh-quality resonators in spectroscopy...
Classical and quantum resonances for hyperbolic surfaces
Guillarmou, Colin; Hilgert, Joachim; Weich, Tobias
2016-01-01
For compact and for convex co-compact oriented hyperbolic surfaces, we prove an explicit correspondence between classical Ruelle resonant states and quantum resonant states, except at negative integers where the correspondence involves holomorphic sections of line bundles.
Optical resonance of metal-coated nanoshell
Institute of Scientific and Technical Information of China (English)
Diao Jia-Jie(刁佳杰); Chen Guang-De(陈光德); Xi Cong(席聪); Z Y Fan; Yuan Jin-She(苑进社)
2003-01-01
Metal-coated nanoshell, the nanoparticle consisting of a nanometre-scale dielectric core coated with a thin metallic shell, exhibits three distinct optical resonant forms, the sphere cavity resonance (SCR), plasmon resonance (PR), and concentric dielectric sphere resonance (CDSR). The SCR, PR and CDSR of the metal-coated nanoshell reveal a geometric tunability controlled by the core radius and by the ratio of the core radius to the total radius. Classical electrodynamics and Mie scattering theory are used to treat the resonant forms and the transition state between the resonant forms. Based on previous experimental research, we present a group of resonant equations for all the resonant forms, which depend on the geometric structure of the metal-coated nanoshell.
Spatially coherent surface resonance states derived from magnetic resonances
Wei, Zeyong; Cao, Yang; Wu, Chao; Ren, Jinzhi; Hang, Zhihong; Chen, Hong; Zhang, Daozhong; Chan, C T
2010-01-01
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.
Theory of atomic motion in resonant radiation
Energy Technology Data Exchange (ETDEWEB)
Cook, R.J.
1980-03-01
Atomic motion in resonant and near resonant electromagnetic radiation is investigated theoretically. The exposition begins with a study of atomic motion in a resonant standing light wave, with a view toward isotope separation by selective photodeflection, and proceeds to the investigation of more general problems of atomic motion in resonant radiation. The body of the work consists of six chapters, each of which was prepared as a manuscript for publication in the open literature.
Regeneration of ZVS converter with Resonant inductor
Directory of Open Access Journals (Sweden)
J.Sivavara Prasad
2011-09-01
Full Text Available This paper presents an analysis of the regeneration of zero-voltage-switching converter with resonant inductor, quasi-resonant converters, and full-bridge zero-voltage-switched PWM Converter. The design of a clamping circuit considering a saturable resonant inductor is presented and compared with the design of a clamping circuit with a linear resonant inductor. A diode model with reverse recovery is employed to simulate the effects.
Nonlinear Thermal Compensators for WGM Resonators
Savchenkov, Anatoliy; Matsko, Andrey; Strekalov, Dmitry; Maleki, Lute; Yu, Nan; Iltchenko, Vladimir
2009-01-01
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.
Electrically Tunable Plasmonic Resonances with Graphene
DEFF Research Database (Denmark)
Emani, Naresh K.; Chung, Ting-Fung; Ni, Xingjie
2012-01-01
Real time switching of a plasmonic resonance may find numerous applications in subwavelength optoelectronics, spectroscopy and sensing. We take advantage of electrically tunable interband transitions in graphene to control the strength of the plasmonic resonance.......Real time switching of a plasmonic resonance may find numerous applications in subwavelength optoelectronics, spectroscopy and sensing. We take advantage of electrically tunable interband transitions in graphene to control the strength of the plasmonic resonance....
Study of resonance in wind parks
Monjo, Lluis; Sainz, Luis; Liang, Jun; Pedra, Joaquín
2015-01-01
Wind turbine harmonic current emissions are a well-known power quality problem. These emissions flow through wind park impedances, leading to grid voltage distortion. Parallel resonance may worsen the problem because it increases voltage distortion around the resonance frequency. Hence, it is interesting to analyze the parallel resonance phenomenon. The paper explores this phenomenon in wind parks and provides analytical expressions to determine parallel resonances. (C) 2015 The Authors. Publ...
Parametric resonance in neutrino oscillations in matter
Indian Academy of Sciences (India)
E Kh Akhmedov
2000-01-01
Neutrino oscillations in matter can exhibit a specific resonance enhancement - parametric resonance, which is different from the MSW resonance. Oscillations of atmospheric and solar neutrinos inside the earth can undergo parametric enhancement when neutrino trajectories cross the core of the earth. In this paper we review the parametric resonance of neutrino oscillations in matter. In particular, physical interpretation of the effect and the prospects of its experimental observation in oscillations of solar and atmospheric neutrinos in the earth are discussed.
Electromagnetic Transmission Through Resonant Structures
Young, Steven M.
Electromagnetic resonators store energy in the form of oscillatory electric and magnetic fields and gradually exchange that energy by coupling with their environment. This coupling process can have profound effects on the transmission and reflection properties of nearby interfaces, with rapid transitions from high transmittance to high reflectance over narrow frequency ranges, and has been exploited to design useful optical components such as spectral filters and dielectric mirrors. This dissertation includes analytic, numeric, and experimental investigations of three different electromagnetic resonators, each based on a different method of confining electromagnetic fields near the region of interest. First, we show that a structure with two parallel conducting plates, each containing a subwavelength slit, supports a localized resonant mode bound to the slits and therefore exhibits (in the absence of nonradiative losses), perfect resonant transmission over a narrow frequency range. In practice, the transmission is limited by conduction losses in the sidewalls; nevertheless, experimental results at 10 GHz show a narrowband transmission enhancement by a factor of 104 compared to the non-resonant transmission, with quality factor (ratio of frequency to peak width) Q ~ 3000. Second, we describe a narrowband transmission filter based on a single-layer dielectric grating. We use a group theory analysis to show that, due to their symmetry, several of the grating modes cannot couple to light at normal incidence, while several others have extremely large coupling. We then show how selectively breaking the system symmetry using off-normal light incidence can produce transmission peaks by enabling weak coupling to some of the previously protected modes. The narrowband filtering capabilities are validated by an experimental demonstration in the long wavelength infrared, showing transmission peaks of quality factor Q ~ 100 within a free-spectral range of 8-15 mum. Third, we
Relationship between Fermi Resonance and Solvent Effects
Institute of Scientific and Technical Information of China (English)
JIANG Xiu-Lan; LI Dong-Fei; SUN Cheng-Lin; LI Zhan-Long; YANG Guang; ZHOU Mi; LI Zuo-Wei; GAO Shu-Qin
2011-01-01
We theoretically and experimentally study the relationship between Fermi resonance and solvent effects and investigate the Fermi resonance of p-benzoquinone and cyclopentanone in different solvents and the Fermi resonance of CS2 in C6H6 at different concentrations. Also, we investigate the Fermi resonance of C6H6 and CCl4 in their solution at different pressures. It is found that solvent effects can be utilized to search Fermi resonance parameters such as coupling coefficient and spectral intensity ratio, etc., on the other hand, the mechanism of solvent effects can be revealed according to Fermi resonance at high pressure.%@@ We theoretically and experimentally study the relationship between Fermi resonance and solvent effects and investigate the Fermi resonance of p-benzoquinone and cyclopentanone in different solvents and the Fermi resonance of CS2 in C6H6 at different concentrations.Also,we investigate the Fermi resonance of C6H6 and CCl4 in their solution at different pressures.It is found that solvent effects can be utilized to search Fermi resonance parameters such as coupling coefficient and spectral intensity ratio,etc.,on the other hand,the mechanism of solvent effects can be revealed according to Fermi resonance at high pressure.
Metamaterial localized resonance sensors: prospects and limitations
DEFF Research Database (Denmark)
Jeppesen, Claus; Xiao, Sanshui; Mortensen, Asger;
2010-01-01
The prospects and limitations of metamaterial localized resonance sensors are investigated theoretically and experimentally. Gold split-ring resonators are employed as the model system where the light induced LC-resonance yields a figure-of-merit, sensitivity divided by linewidth, up to 54 depend...
Saturating optical resonances in quantum dots
Nair, Selvakumar V.; Rustagi, K. C.
Optical bistability in quantum dots, recently proposed by Chemla and Miller, is studied in a two-resonance model. We show that for such classical electromagnetic resonances the applicability of a two-resonance model is far more restrictive than for those in atoms.
A Family of Resonant Vibration Control Formats
DEFF Research Database (Denmark)
Krenk, Steen; Høgsberg, Jan Becker
Resonant control makes use of a controller with a resonance frequency and an equivalent damping ratio. A simple explicit calibration procedure is presented for a family of resonant controllers in which the frequency is tuned to the natural frequency of the targeted mode in such a way that the two...
Progress Toward Understanding Baryon Resonances
Crede, Volker
2013-01-01
The composite nature of baryons manifests itself in the existence of a rich spectrum of excited states, in particular in the important mass region 1-2 GeV for the light-flavoured baryons. The properties of these resonances can be identified by systematic investigations using electromagnetic and strong probes, primarily with beams of electrons, photons, and pions. After decades of research, the fundamental degrees of freedom underlying the baryon excitation spectrum are still poorly understood. The search for hitherto undiscovered but predicted resonances continues at many laboratories around the world. Recent results from photo- and electroproduction experiments provide intriguing indications for new states and shed light on the structure of some of the known nucleon excitations. The continuing study of available data sets with consideration of new observables and improved analysis tools have also called into question some of the earlier findings in baryon spectroscopy. Other breakthrough measurements have be...
Soliton crystals in Kerr resonators
Cole, Daniel C; Del'Haye, Pascal; Diddams, Scott A; Papp, Scott B
2016-01-01
Solitons are pulses that propagate without spreading due to a balance between nonlinearity and dispersion (or diffraction), and are universal features of systems exhibiting these effects. Solitons play an important role in plasma physics, fluid dynamics, atomic physics, biology, and optics. In the context of integrated photonics, bright dissipative cavity solitons in Kerr-nonlinear resonators are envisioned to play an important role in next-generation communication, computation, and measurement systems. Here we report the discovery of soliton crystals in Kerr resonators-collectively ordered ensembles of co-propagating solitons with discrete allowed temporal separations. Through analysis of optical spectra, we identify a complicated but discrete space of interacting soliton configurations, including crystals exhibiting vacancies (Schottky defects), shifted pulses (Frenkel defects), and superstructure. Time-domain characterization of the output-coupled soliton pulse train directly confirms our inference of the ...
Optical antennas as nanoscale resonators.
Agio, Mario
2012-02-07
Recent progress in nanotechnology has enabled us to fabricate sub-wavelength architectures that function as antennas for improving the exchange of optical energy with nanoscale matter. We describe the main features of optical antennas for enhancing quantum emitters and review the designs that increase the spontaneous emission rate by orders of magnitude from the ultraviolet up to the near-infrared spectral range. To further explore how optical antennas may lead to unprecedented regimes of light-matter interactions, we draw a relationship between metal nanoparticles, radio-wave antennas and optical resonators. Our analysis points out how optical antennas may function as nanoscale resonators and how these may offer unique opportunities with respect to state-of-the-art microcavities.
Resonantly enhanced filamentation in gases
Doussot, J; Billard, F; Béjot, P; Faucher, O
2016-01-01
In this Letter, a low-loss Kerr-driven optical filament in Krypton gas is experimentally reported in the ultraviolet. The experimental findings are supported by ab initio quantum calculations describing the atomic optical response. Higher-order Kerr effect induced by three-photon resonant transitions is identified as the underlying physical mechanism responsible for the intensity stabilization during the filamentation process, while ionization plays only a minor role. This result goes beyond the commonly-admitted paradigm of filamentation, in which ionization is a necessary condition of the filament intensity clamping. At resonance, it is also experimentally demonstrated that the filament length is greatly extended because of a strong decrease of the optical losses.
Resonant spectra of quadrupolar anions
Fossez, K; Nazarewicz, W; Michel, N; Garrett, W R; Płoszajczak, M
2016-01-01
In quadrupole-bound anions, an extra electron is attached at a sufficiently large quadrupole moment of a neutral molecule, which is lacking a permanent dipole moment. The nature of the bound states and low-lying resonances of such anions is of interest for understanding the threshold behavior of open quantum systems in general. In this work, we investigate the properties of quadrupolar anions as extreme halo systems, the formation of rotational bands, and the transition from a subcritical to supercritical electric quadrupole moment. We solve the electron-plus-molecule problem using a non-adiabatic coupled-channel formalism by employing the Berggren ensemble, which explicitly contains bound states, narrow resonances, and the scattering continuum. We demonstrate that binding energies and radii of quadrupolar anions strictly follow the scaling laws for two-body halo systems. Contrary to the case of dipolar anions, ground-state band of quadrupolar anions smoothly extend into the continuum, and many rotational ban...
Optical antennas as nanoscale resonators
Agio, Mario
2011-01-01
Recent progress in nanotechnology has enabled us to fabricate subwavelength architectures that function as antennas for improving the exchange of optical energy with nanoscale matter. We describe the main features of optical antennas for enhancing quantum emitters and review designs that increase the spontaneous emission rate by orders of magnitude from the ultraviolet up to the near-infrared spectral range. To further explore how optical antennas may lead to unprecedented regimes of light-matter interaction, we draw a relationship between metal nanoparticles, radio-wave antennas and optical resonators. Our analysis points out how optical antennas may function as nanoscale resonators and how these may offer unique opportunities with respect to state-of-the-art microcavities.
Dynamic control of chaotic resonators
Di Falco, A.
2016-02-16
We report on the all-optical control of chaotic optical resonators based on silicon on insulator (SOI) platform. We show that simple non-chaotic cavities can be tuned to exhibit chaotic behavior via intense optical pump- ing, inducing a local change of refractive index. To this extent we have fabricated a number of devices and demonstrated experimentally and theoretically that chaos can be triggered on demand on an optical chip. © 2016 SPIE.
Formation time of hadronic resonances
Directory of Open Access Journals (Sweden)
Vitev Ivan
2012-11-01
Full Text Available In heavy-ion collisions, formation time of hadrons of high transverse momentum can play a pivotal role in determining the perturbative dynamics of the final-state parton and particle system. We present methods to evaluate the formation times of light hadrons, hadronic resonances, open heavy flavor and quarkonia. Experimental implications of the short formation times of heavy particles are discussed in light of recent RHIC and LHC data.
Automated Nuclear Quadruple Resonance Spectrometer
Directory of Open Access Journals (Sweden)
IVANCHUK, M.
2008-06-01
Full Text Available Improvement of an autodyne Nuclear quadruple resonance spectrometer is offered. The change of frequency of oscillatory LC circuit of the spectrometer is carried out in two ways: by varicap and variable capacitor. A processor module for the capacitor and varicap control is developed. The unit allows to scan and measure the level and frequency of the NQR-signal. The unit is controlled by the personal computer.
Strange decays from strange resonances
Bijker, R
2001-01-01
We discuss the mass spectrum and strong decays of baryon resonances belonging to the N, Delta, Sigma, Lambda, Xi and Omega families in a collective string-like model for the nucleon. We find good overall agreement with the available data. Systematic discrepancies are found for lowlying S-wave states, in particular in the strong decays of N(1535), N(1650), Sigma(1750), Lambda(1405), Lambda(1670) and Lambda(1800).
Strange decays from strange resonances
Energy Technology Data Exchange (ETDEWEB)
Bijker, R. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A.P. 70-543, 04510 Mexico D.F. (Mexico); Leviatan, A. [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel)
2001-07-01
We discuss the mass spectrum and strong decays of baryon resonances belonging to the N, {delta}, {sigma}, {lambda}, {xi} and {omega} families in a collective string- like model for the nucleon. We find good overall agreement with the available data. Systematic discrepancies are found for low-lying S-wave states, in particular in the strong decays of N(1535), N(1650), {sigma}(1750), {lambda}{sup *}(1405), {lambda}(1670) and {lambda}(1800). (Author)
Nucleon Resonance Transition Form factors
Energy Technology Data Exchange (ETDEWEB)
Burkert, Volker D. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Mokeev, Viktor I. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Aznauryan, Inna G. [Yerevan Physics Inst. (YerPhI) (Armenia)
2016-08-01
We discuss recent results from CLAS on electromagnetic resonance transition amplitudes and their dependence on the distance scale (Q2). From the comparison of these results with most advanced theoretical calculations within QCD-based approaches there is clear evidence that meson-baryon contributions are present and important at large distances, i.e. small Q2, and that quark core contributions dominate the short distance behavior.
Automated Nuclear Quadruple Resonance Spectrometer
2008-01-01
Improvement of an autodyne Nuclear quadruple resonance spectrometer is offered. The change of frequency of oscillatory LC circuit of the spectrometer is carried out in two ways: by varicap and variable capacitor. A processor module for the capacitor and varicap control is developed. The unit allows to scan and measure the level and frequency of the NQR-signal. The unit is controlled by the personal computer.
Magnetoacoustic resonance in magnetoelectric bilayers
Filippov, D. A.; Bichurin, M. I.; Petrov, V. M.; Srinivasan, G.
2004-03-01
Layered composites of ferrite and ferroelectric single crystal thin films are of interest for studies on magnetoelectric interactions [1,2]. Such interactions result in unique and novel effects that are absent in single phase materials. For example, in a single crystal composite it is possible to control the ferromagnetic resonance (FMR) parameters for the ferrite by means of hypersonic oscillations induced in the ferroelectric phase. The absorption of acoustic oscillations by the ferrite results in variation in FMR line shape and power absorbed. One anticipates resonance absorption of elastic waves when the frequency of elastic waves coincides with the precession frequency of magnetization vector. This work is concerned with the nature of FMR under the influence of acoustic oscillations with the same frequency as FMR. Bilayers of ferrite and piezoelectric single crystals are considered. Hypersonic waves induced in the piezoelectric phase transmit acoustic power into ferrite due to mechanical connectivity between the phases. That transmission depends strongly on interface coupling [3]. We estimate the resulting variations in ferromagnetic resonance line shape. Estimates of magnetoelectric effect at magnetoacoustic resonance are also given. In addition, dependence of absorption of acoustic power on sample dimensions and compliances, electric and magnetic susceptibilities, piezoelectric and magnetostriction coefficients is discussed. The theory provided here is important for an understanding of interface coupling and the nature of magnetoelastic interactions in the composites. 1. M. I. Bichurin and V. M. Petrov, Zh. Tekh. Fiz. 58, 2277 (1988) [Sov. Phys. Tech. Phys. 33, 1389 (1988)]. 2. M.I. Bichurin, I. A. Kornev, V. M. Petrov, A. S. Tatarenko, Yu. V. Kiliba, and G. Srinivasan. Phys. Rev. B 64, 094409 (2001). 3. M. I. Bichurin, V. M. Petrov, and G. Srinivasan, J. Appl. Phys. 92, 7681 (2002). This work was supported by grants from the Russian Ministry of Education (
Proton Resonance Spectroscopy -- Final Report
Energy Technology Data Exchange (ETDEWEB)
Shriner, Jr, J F
2009-07-27
This report summarizes work supported by the DOE Grant DE-FG02-96ER40990 during its duration from June 1996 to May 2009. Topics studied include (1) statistical descriptions of nuclear levels and measurements of proton resonances relevant to such descriptions, including measurements toward a complete level scheme for 30P, (2) the development of methods to estimate the missing fraction of levels in a given measurement, and (3) measurements at HRIBF relevant to nuclear astrophysics.
Capacitance of circular patch resonator
Energy Technology Data Exchange (ETDEWEB)
Miano, G.; Verolino, L. [Dip. di Ingegneria Elettrica, Ist. Nazionale di Fisica Nucleare, Naples (Italy); Panariello, G. [Dip. di Ingegneria Elettronica, Naples (Italy); Vaccaro, V.G. [Ist. Nazionale di Fisica Nucleare, Naples (Italy). Dipt. di Scienze Fisiche
1995-11-01
In this paper the capacitance of the circular microstrip patch resonator is computed. It is shown that the electrostatic problem can be formulated as a system of dual integral equations, and the most interesting techniques of solutions of these systems are reviewed. Some useful approximated formulas for the capacitance are derived and plots of the capacitance are finally given in a wide range of dielectric constants.
Vector-Resonance-Multimode Instability
Sergeyev, S. V.; Kbashi, H.; Tarasov, N.; Loiko, Yu.; Kolpakov, S. A.
2017-01-01
The modulation and multimode instabilities are the main mechanisms which drive spontaneous spatial and temporal pattern formation in a vast number of nonlinear systems ranging from biology to laser physics. Using an Er-doped fiber laser as a test bed, here for the first time we demonstrate both experimentally and theoretically a new type of a low-threshold vector-resonance-multimode instability which inherits features of multimode and modulation instabilities. The same as for the multimode instability, a large number of longitudinal modes can be excited without mode synchronization. To enable modulation instability, we modulate the state of polarization of the lasing signal with the period of the beat length by an adjustment of the in-cavity birefringence and the state of polarization of the pump wave. As a result, we show the regime's tunability from complex oscillatory to periodic with longitudinal mode synchronization in the case of resonance matching between the beat and cavity lengths. Apart from the interest in laser physics for unlocking the tunability and stability of dynamic regimes, the proposed mechanism of the vector-resonance-multimode instability can be of fundamental interest for the nonlinear dynamics of various distributed systems.
Traces of a triboson resonance
Aguilar-Saavedra, J. A.; Collins, J. H.; Lombardo, S.
2016-09-01
We show that the relatively small but coincident excesses observed around 2 TeV in the ATLAS Run 1 and Run 2 hadronic diboson searches — when a cut on the number of tracks in the fat jets is not applied — and the null results of all remaining high-mass diboson searches are compatible with the decay of a triboson resonance R into WZ plus an extra particle X. These decays can take place via new neutral ( Y 0) or charged ( Y ±) particles, namely R → Y 0 W, with Y 0 → ZX, or R → Y ± Z, with Y ± → WX. An obvious candidate for such intermediate particle is a neutral one Y 0, given a 3 .9 σ excess found at 650 GeV by the CMS Collaboration in searches for intermediate mass diboson resonances decaying to ZV, with V = W, Z. We discuss discovery strategies for triboson resonances with small modifications of existing hadronic searches.
Cea, Paolo
2016-01-01
We present an alternative interpretation within the Standard Model of the new LHC resonance at $125 \\; GeV$. We further elaborate on our previous proposal that the resonance at 125 GeV could be interpreted as a pseudoscalar meson with quantum number $J^{PC} = 0^{- +}$. We develop a phenomenological approach where this pseudoscalar mimics the decays of the Standard Model Higgs boson in the vector boson decay channels. We propose that the true Higgs boson should be a heavy resonance with mass of $750 \\, GeV$ as argued in Ref.~\\cite{Cea:2012}. We determine the most relevant decay modes and estimate the partial decay widths and branching ratios. We also discuss briefly the experimental signatures of this heavy Higgs boson. Finally, we attempt a comparison of our theoretical expectations with recent data at $\\sqrt{s} =13 \\,TeV$ from ATLAS and CMS experiments in the so-called golden channel. We find that the available experimental data could be consistent with the heavy Higgs scenario.
eta Photoproduction and N* resonances
Choi, Ki-Seok; Hosaka, Atsushi; Kim, Hyun-Chul
2007-01-01
We investigate the eta photoproduction from the nucleon using the effective Lagrangian approach at tree level. We focus on the nucleon resonance N*(1675) of possibly exotic nature, which was reported by the GRAAL, Tohoku LNS and CB-ELSA examining its spin and parity theoretically. In addition, we consider six nucleon resonances, D_{13}(1520), S_{11}(1535), S_{11}(1650), D_{15}(1675), P_{11}(1710), P_{13}(1720) as well as possible background contributions. We calculate the differential cross sections and beam asymmetries for the neutron and proton targets. They indicate that there is isospin asymmetry which can be interpreted as the large difference in the the transition photon couplings: mu_{gamma p p*} << mu_{gamma n n*}. Moreover, we find that the spin-1/2 state is preferred in order to reproduce the experimental data, although its parity remains undetermined. This observation implies that the new resonance may be identified as a non-strangeness member of the baryon antidecuplet.
Traces of a triboson resonance
Aguilar-Saavedra, J A; Lombardo, S
2016-01-01
We show that the relatively small but coincident excesses observed around 2 TeV in the ATLAS Run 1 and Run 2 hadronic diboson searches --- when a cut on the number of tracks in the fat jets is not applied --- and the null results of all remaining high-mass diboson searches are compatible with the decay of a triboson resonance $R$ into $WZ$ plus an extra particle $X$. These decays can take place via new neutral ($Y^0$) or charged ($Y^\\pm$) particles, namely $R \\to Y^0 \\, W$, with $Y^0 \\to Z X$, or $R \\to Y^\\pm Z$, with $Y^\\pm \\to W X$. An obvious candidate for such intermediate particle is a neutral one $Y^0$, given a $3.9\\sigma$ excess found at 650 GeV by the CMS Collaboration in searches for intermediate mass diboson resonances decaying to $ZV$, with $V=W,Z$. We discuss discovery strategies for triboson resonances with small modifications of existing hadronic searches.
Diphoton resonance confronts dark matter
Choi, Soo-Min; Kang, Yoo-Jin; Lee, Hyun Min
2016-07-01
As an interpretation of the 750 GeV diphoton excesses recently reported by both ATLAS and CMS collaborations, we consider a simple extension of the Standard Model with a Dirac fermion dark matter where a singlet complex scalar field mediates between dark matter and SM particles via effective couplings to SM gauge bosons and/or Higgs-portal. In this model, we can accommodate the diphoton events through the direct and/or cascade decays of pseudo-scalar and real scalar partners of the complex scalar field. We show that mono-jet searches and gamma-ray observations are complementary in constraining the region where the width of the diphoton resonance can be enhanced due to the couplings of the resonance to dark matter and the correct relic density is obtained. In the case of cascade decay of the resonance, the effective couplings of singlet scalars can be smaller, but the model is still testable by the future discrimination between single photon and photon-jet at the LHC as well as the gamma-ray searches for the cascade annihilation of dark matter.
Diphoton resonance confronts dark matter
Choi, Soo-Min; Lee, Hyun Min
2016-01-01
As an interpretation of the 750 GeV diphoton excesses recently reported by both ATLAS and CMS collaborations, we consider a simple extension of the Standard Model with a Dirac fermion dark matter where a singlet complex scalar field mediates between dark matter and SM particles via effective couplings to SM gauge bosons and/or Higgs-portal. In this model, we can accommodate the diphoton events through the direct and/or cascade decays of pseudo-scalar and real scalar partners of the complex scalar field. We show that mono-jet searches and gamma-ray observations are complementary in constraining the region where the width of the diphoton resonance can be enhanced due to the couplings of the resonance to dark matter and the correct relic density is obtained. In the case of cascade decay of the resonance, the effective couplings of singlet scalars can be smaller, but the model is still testable by the future discrimination between single photon and photon-jet at the LHC as well as the gamma-ray searches for the c...
Distributed optical fiber surface plasmon resonance sensors
Institute of Scientific and Technical Information of China (English)
Zhenxin Cao; Lenan Wu; Dayong Li
2006-01-01
@@ The relationships of the resonant wavelength of optical fiber surface plasmon resonance (SPR) sensors to the modulation layer refractive index, thickness and the refractive index of the bulk medium are obtained by using theoretical calculation model of optical fiber SPR sensors under certain conditions, which indicates that resonant wavelength of the sensors is approximately linear with modulation layer thickness. Based on the linear relationship, multiple SPR sensors with different resonant wavelengths can be fabricated in a single optical fiber named as distributed optical fiber surface plasmon resonance sensors (DOFSPRSs).Experimental results are presented, showing that it is practical to fabricate more than one SPR sensors in a single optical fiber.
Spatial filtering with surface plasmon resonance systems
Ghosh, A. K.; Siddharth, V.; Bhagat, M.; Aggarwal, S.; Anurag, P.; Jain, M.
2007-09-01
Surface plasmon resonance based sensors are most useful in measuring the refractive indices of biochemicals. In such sensors a beam of light obliquely incident at an interface of glass and metallic thin film excites resonant plasmon waves in the metal if the angle of incidence or the wavelength is selected properly. The resonance conditions are changed by the refractive indices of any material in contact with the metal film. When resonance occurs the light beam is absorbed strongly. We can easily show that the phenomenon of surface plasmon resonance in such a system acts as a high quality spatial notch or band rejection filter.
Observation of a Hybrid Spin Resonance
Bai, M.; Allgower, C.; Ahrens, L.; Alessi, J.; Brown, K.; Bunce, G.; Cameron, P.; Chu, C. M.; Courant, E. D.; Glenn, J. W.; Huang, H.; Jeon, D.; Kponou, A. E.; Krueger, K.; Luccio, A.; Makdisi, Y. I.; Lee, S. Y.; Ratner, L.; Reece, K.; Roser, T.; Spinka, H.; Syphers, M. J.; Tsoupas, N.; Underwood, D. G.; van Asselt, W.; Williams, N.; Yokosawa, A.
2000-02-01
A new type of spin depolarization resonance has been observed at the Brookhaven Alternating Gradient Synchrotron (AGS). This spin resonance is identified as a strong closed-orbit sideband around the dominant intrinsic spin resonance. The strength of the resonance was proportional to the 9th harmonic component of the horizontal closed orbit and proportional to the vertical betatron oscillation amplitude. This ``hybrid'' spin resonance cannot be overcome by the partial snake at the AGS, but it can be corrected by the harmonic orbit correctors.
The 4:1 resonance (spiral galaxies)
Contopoulos, George
1981-01-01
Studies the resonance omega /sub 1/: omega /sub 2/=4:1 and some near- resonance cases. The main peculiarity of this resonance is that for omega /sub 1/: omega /sub 2/<4 the characteristic of the central periodic orbits is broken into two and each part is joined with a resonant characteristic. The behaviour is described theoretically by means of the 'third' integral. It seems that there are infinite families of simple periodic orbits near the escape region. Finally, a comparison is made with the cases near the omega /sub 1/: omega /sub 2 /=2:1 resonance. (8 refs).
Resonant circuit model for efficient metamaterial absorber.
Sellier, Alexandre; Teperik, Tatiana V; de Lustrac, André
2013-11-04
The resonant absorption in a planar metamaterial is studied theoretically. We present a simple physical model describing this phenomenon in terms of equivalent resonant circuit. We discuss the role of radiative and dissipative damping of resonant mode supported by a metamaterial in the formation of absorption spectra. We show that the results of rigorous calculations of Maxwell equations can be fully retrieved with simple model describing the system in terms of equivalent resonant circuit. This simple model allows us to explain the total absorption effect observed in the system on a common physical ground by referring it to the impedance matching condition at the resonance.
Equivalent Circuit Model for Thick Split Ring Resonators and Thick Spiral Resonators
Mancera, Laura Maria Pulido
2014-01-01
A simple theoretical model which provides circuit parameters and resonance frequency of metallic thick resonators is presented. Two different topologies were studied: the original Pendry's SRR and spiral resonators of two and three turns. Theoretical computations of resonant frequencies are in good agreement with values obtained with a commercial electromagnetic solver. The model could be helpful for designing thick frequency selective surfaces (FSS) based on this types of resonators, so called metasurfaces.
Effect of metal coating and residual stress on the resonant frequency of MEMS resonators
Pandey, Ashok Kumar; Venkatesh, KP; Pratap, Rudra
2009-01-01
MEMS resonators are designed for a fixed resonant frequency. Therefore, any shift in the resonant frequency of the final fabricated structure can be a denting factor for its suitability towards a desired application. There are numerous factors which alter the designed resonant frequency of the fabricated resonator such as the metal layer deposited on top of the beam and the residual stresses present in the fabricated structure. While the metal coating, which acts as electrode, increases t...
Extraordinary acoustic transmission mediated by Helmholtz resonators
Directory of Open Access Journals (Sweden)
Vijay Koju
2014-07-01
Full Text Available We demonstrate perfect transmission of sound through a rigid barrier embedded with Helmholtz resonators. The resonators are confined within a waveguide and they are oriented such that one neck protrudes onto each side of the barrier. Perfect sound transmission occurs even though the open area of the necks is less than 3% of the barrier area. Maximum transmission occurs at the resonant frequency of the Helmholtz resonator. Because the dimensions of the Helmholtz resonators are much smaller than the resonant wavelength, the transmission is independent of the direction of sound on the barrier and of the relative placement of the necks. Further, we show that the transmitted sound experiences a continuous phase transition of π radians as a function of frequency through resonance. In simulations of adjacent resonators with slightly offset resonance frequencies, the phase difference leads to destructive interference. By expanding the simulation to a linear array of tuned Helmholtz resonators we show that it is possible to create an acoustic lens. The ability of Helmholtz resonator arrays to manipulate the phase of a plane acoustic wave enables a new class of sonic beam-forming devices analogous to diffractive optics.
Extraordinary acoustic transmission mediated by Helmholtz resonators
Koju, Vijay; Rowe, Ebony; Robertson, William M.
2014-07-01
We demonstrate perfect transmission of sound through a rigid barrier embedded with Helmholtz resonators. The resonators are confined within a waveguide and they are oriented such that one neck protrudes onto each side of the barrier. Perfect sound transmission occurs even though the open area of the necks is less than 3% of the barrier area. Maximum transmission occurs at the resonant frequency of the Helmholtz resonator. Because the dimensions of the Helmholtz resonators are much smaller than the resonant wavelength, the transmission is independent of the direction of sound on the barrier and of the relative placement of the necks. Further, we show that the transmitted sound experiences a continuous phase transition of π radians as a function of frequency through resonance. In simulations of adjacent resonators with slightly offset resonance frequencies, the phase difference leads to destructive interference. By expanding the simulation to a linear array of tuned Helmholtz resonators we show that it is possible to create an acoustic lens. The ability of Helmholtz resonator arrays to manipulate the phase of a plane acoustic wave enables a new class of sonic beam-forming devices analogous to diffractive optics.
Super-Resonant Intracavity Coherent Absorption
Malara, P.; Campanella, C. E.; Giorgini, A.; Avino, S.; de Natale, P.; Gagliardi, G.
2016-07-01
The capability of optical resonators to extend the effective radiation-matter interaction length originates from a multipass effect, hence is intrinsically limited by the resonator’s quality factor. Here, we show that this constraint can be overcome by combining the concepts of resonant interaction and coherent perfect absorption (CPA). We demonstrate and investigate super-resonant coherent absorption in a coupled Fabry-Perot (FP)/ring cavity structure. At the FP resonant wavelengths, the described phenomenon gives rise to split modes with a nearly-transparent peak and a peak whose transmission is exceptionally sensitive to the intracavity loss. For small losses, the effective interaction pathlength of these modes is proportional respectively to the ratio and the product of the individual finesse coefficients of the two resonators. The results presented extend the conventional definition of resonant absorption and point to a way of circumventing the technological limitations of ultrahigh-quality resonators in spectroscopy and optical sensing schemes.
Compact electric-LC resonators for metamaterials
Withayachumnankul, Withawat; Abbott, Derek
2010-01-01
Alternative designs to an electric-LC (ELC) resonator, which is a type of metamaterial inclusion, are presented in this article. Fitting the resonator with an interdigital capacitor (IDC) helps to increase the total capacitance of the structure. In effect, its resonance frequency is shifted downwards. This implies a decreased overall resonator size with respect to its operating wavelength. As a result, the metamaterial, composed of an array of IDC-loaded ELC resonators with their collective electromagnetic response, possesses improved homogeneity and hence is less influenced by diffraction effects of individual cells. The impact of incorporating an IDC into ELC resonators in terms of the electrical size at resonance and other relevant properties are investigated through both simulation and experiment.
Dielectric square resonator investigated with microwave experiments.
Bittner, S; Bogomolny, E; Dietz, B; Miski-Oglu, M; Richter, A
2014-11-01
We present a detailed experimental study of the symmetry properties and the momentum space representation of the field distributions of a dielectric square resonator as well as the comparison with a semiclassical model. The experiments have been performed with a flat ceramic microwave resonator. Both the resonance spectra and the field distributions were measured. The momentum space representations of the latter evidenced that the resonant states are each related to a specific classical torus, leading to the regular structure of the spectrum. Furthermore, they allow for a precise determination of the refractive index. Measurements with different arrangements of the emitting and the receiving antennas were performed and their influence on the symmetry properties of the field distributions was investigated in detail, showing that resonances with specific symmetries can be selected purposefully. In addition, the length spectrum deduced from the measured resonance spectra and the trace formula for the dielectric square resonator are discussed in the framework of the semiclassical model.
Gold nanodisk array surface plasmon resonance sensor
Tian, Xueli
Surface plasmon resonances in periodic metal nanostructures have been investigated for sensing applications over the last decade. The resonance wavelengths of the nanostructures are usually measured in the transmission or reflection spectrum for chemical and biological sensing. In this thesis, I introduce a nanoscale gap mediated surface plasmon resonance nanodisk array for displacement sensing and a super-period gold nanodisk grating enabled surface plasmon resonance spectrometer sensor. The super-period gold nanodisk grating has a small subwavelength period and a large diffraction grating period. Surface plasmon resonance spectra are measured in the first order diffraction spatial profiles captured by a charge-coupled device (CCD). A surface plasmon resonance sensor for the bovine serum albumin (BSA) protein nanolayer bonding is demonstrated by measuring the surface plasmon resonance shift in the first order diffraction spatial intensity profiles captured by the CCD.
Wijnant, Y.H.
2006-01-01
For quite a few number of years now, the Structural Dynamics and Acoustics group at the University of Twente studies wave propagation in narrow gaps (e.g. thermal-viscous wave propagation in narrow tubes and thin air layers). The waves propagating in these narrow gaps can be described elegantly by m
Resonantly detecting axion-mediated forces with nuclear magnetic resonance.
Arvanitaki, Asimina; Geraci, Andrew A
2014-10-17
We describe a method based on precision magnetometry that can extend the search for axion-mediated spin-dependent forces by several orders of magnitude. By combining techniques used in nuclear magnetic resonance and short-distance tests of gravity, our approach can substantially improve upon current experimental limits set by astrophysics, and probe deep into the theoretically interesting regime for the Peccei-Quinn (PQ) axion. Our method is sensitive to PQ axion decay constants between 10(9) and 10(12) GeV or axion masses between 10(-6) and 10(-3) eV, independent of the cosmic axion abundance.
Campione, Salvatore; Warne, Larry K; Sinclair, Michael B
2014-01-01
In this paper we describe a methodology for tailoring the design of metamaterial dielectric resonators, which represent a promising path toward low-loss metamaterials at optical frequencies. We first describe a procedure to decompose the far field scattered by subwavelength resonators in terms of multipolar field components, providing explicit expressions for the multipolar far fields. We apply this formulation to confirm that an isolated high-permittivity cube resonator possesses frequency separated electric and magnetic dipole resonances, as well as a magnetic quadrupole resonance in close proximity to the electric dipole resonance. We then introduce multiple dielectric gaps to the resonator geometry in a manner suggested by perturbation theory, and demonstrate the ability to overlap the electric and magnetic dipole resonances, thereby enabling directional scattering by satisfying the first Kerker condition. We further demonstrate the ability to push the quadrupole resonance away from the degenerate dipole ...
Guddala, Sriram; Ramakrishna, S Anantha
2016-01-01
A tri-layer metamaterial perfect absorber of light, consisting of (Al/ZnS/Al) films with the top aluminium layer patterned as an array of circular disk nanoantennas, is investigated for resonantly enhancing Raman scattering from C-60 fullerene molecules deposited on the metamaterial. The metamaterial is designed to have resonant bands due to plasmonic and electromagnetic resonances at the Raman pump frequency (725 nm) as well as Stokes emission bands. The Raman scattering from C60 on the metamaterial with resonantly matched bands is measured to be enhanced by an order of magnitude more than from C60 on metamaterials with off-resonant absorption bands peaked at 1090 nm. The Raman pump is significantly enhanced due to the resonance with a propagating surface plasmon band, while the highly impedance matched electromagnetic resonance is expected to couple out the Raman emission efficiently. The nature and hybridization of the plasmonic and electromagnetic resonances to form compound resonances are investigated by...
Locally Resonant Gaps of Phononic Beams Induced by Periodic Arrays of Resonant Shunts
Institute of Scientific and Technical Information of China (English)
CHEN Sheng-Bing; WEN Ji-Hong; WANG Gang; HAN Xiao-Yun; WEN Xi-Sen
2011-01-01
@@ Periodic arrays of shunted piezoelectric patches are employed to control the propagation of elastic waves in phononic beams.Each piezo-patch is connected to a single resistance-inductance-capacitance shunting circuit.Therefore,the resonances of the shunting circuits will produce locally resonant gaps in the phononic beam.However,the existence of locally resonant gaps induced by resonant shunts has not been clearly proved by experiment so far.In this work,the locally resonant gap in a piezo-shunted phononic beam is investigated theoretically and verified by experiment.The results prove that resonances of shunting circuits can produce locally resonant gaps in phononic beams.%Periodic arrays of shunted piezoelectric patches are employed to control the propagation of elastic waves in phononic beams. Each piezo-patch is connected to a single resistance-inductance-capacitance shunting circuit. Therefore, the resonances of the shunting circuits will produce locally resonant gaps in the phononic beam. However, the existence of locally resonant gaps induced by resonant shunts has not been clearly proved by experiment so far. In this work, the locally resonant gap in a piezo-shunted phononic beam is investigated theoretically and verified by experiment. The results prove that resonances of shunting circuits can produce locally resonant gaps in phononic beams.
High performance Vernier racetrack resonators.
Boeck, Robert; Flueckiger, Jonas; Yun, Han; Chrostowski, Lukas; Jaeger, Nicolas A F
2012-12-15
We demonstrate record performance of series-coupled silicon racetrack resonators exhibiting the Vernier effect. Our device has an interstitial peak suppression (IPS) of 25.5 dB, which is 14.5 dB larger than previously reported results. We also demonstrate the relationship between the inter-ring gap distance and the IPS as well as the 3 dB bandwidth (BW) both theoretically and experimentally. Namely, we show that as the inter-ring gap distance increases, the IPS increases and the 3 dB BW decreases.
Evanescent Waves Nuclear Magnetic Resonance.
Halidi, El Mohamed; Nativel, Eric; Akel, Mohamad; Kenouche, Samir; Coillot, Christophe; Alibert, Eric; Jabakhanji, Bilal; Schimpf, Remy; Zanca, Michel; Stein, Paul; Goze-Bac, Christophe
2016-01-01
Nuclear Magnetic Resonance spectroscopy and imaging can be classified as inductive techniques working in the near- to far-field regimes. We investigate an alternative capacitive detection with the use of micrometer sized probes positioned at sub wavelength distances of the sample in order to characterize and model evanescent electromagnetic fields originating from NMR phenomenon. We report that in this experimental configuration the available NMR signal is one order of magnitude larger and follows an exponential decay inversely proportional to the size of the emitters. Those investigations open a new road to a better understanding of the evanescent waves component in NMR with the opportunity to perform localized spectroscopy and imaging.
Magnetic resonance tomography in syringomyelia
Energy Technology Data Exchange (ETDEWEB)
Koehler, D.; Treisch, J.; Hertel, G.; Schoerner, W.; Fiegler, W.
1985-12-01
Thirteen patients with a clinical diagnosis of syringomyelia were examined by nuclear tomography (0.35 T magnet) in the spin-echo mode. In all thirteen patients, the T1 images (Se 400/35) showed a longitudinal cavity with a signal intensity of CSF. The shape and extent of the syrinx could be adequately demonstrated in 12 of the 13 examinations. Downward displacement of the cerebellar tonsils was seen in eight cases. The examination took between half and one hour. Advantages of magnetic resonance tomography (nuclear tomography) include the absence of artifacts, images in the line of the lesion and its non-invasiveness.
Modeling noisy resonant system response
Weber, Patrick Thomas; Walrath, David Edwin
2017-02-01
In this paper, a theory-based model replicating empirical acoustic resonant signals is presented and studied to understand sources of noise present in acoustic signals. Statistical properties of empirical signals are quantified and a noise amplitude parameter, which models frequency and amplitude-based noise, is created, defined, and presented. This theory-driven model isolates each phenomenon and allows for parameters to be independently studied. Using seven independent degrees of freedom, this model will accurately reproduce qualitative and quantitative properties measured from laboratory data. Results are presented and demonstrate success in replicating qualitative and quantitative properties of experimental data.
Advances in magnetic resonance 3
Waugh, John S
2013-01-01
Advances in Magnetic Resonance, Volume 3, describes a number of important developments which are finding increasing application by chemists. The book contains five chapters and begins with a discussion of how the properties of random molecular rotations reflect themselves in NMR and how they show up, often differently, in other kinds of experiments. This is followed by separate chapters on the Kubo method, showing its equivalence to the Redfield approach in the cases of most general interest; the current state of dynamic nuclear polarization measurements in solutions and what they tell us abou
Hadron scattering, resonances, and QCD
Energy Technology Data Exchange (ETDEWEB)
Briceno, Raul [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2016-12-01
The non-perturbative nature of quantum chromodynamics (QCD) has historically left a gap in our understanding of the connection between the fundamental theory of the strong interactions and the rich structure of experimentally observed phenomena. For the simplest properties of stable hadrons, this is now circumvented with the use of lattice QCD (LQCD). In this talk I discuss a path towards a rigorous determination of few-hadron observables from LQCD. I illustrate the power of the methodology by presenting recently determined scattering amplitudes in the light-meson sector and their resonance content.
Hao, T; Edwards, D J; Stevens, C J
2008-01-01
Methods on reducing resonant frequencies and electrical sizes of resonators are reported in this paper. Theoreti-cal and numerical analysis has been used and the results for the broadside-coupled resonators from both studies exhibit good agreement. Initial fabrication techniques are proposed and measurement results are compared with simulations. Further high resolution techniques have been envisaged to enhance the performance of the resona-tors. This class of small resonators with low resonant frequencies indicates a variety of applications in the design of microwave devices.
Dynamical generation of hadronic resonances
Wolkanowski, Thomas
2014-01-01
One type of dynamical generation consists in the formation of multiple hadronic resonances from single seed states by incorporating hadronic loop contributions on the level of $s$-wave propagators. Along this line, we study the propagator poles within two models of scalar resonances and report on the status of our work: (i) Using a simple quantum field theory describing the decay of $f_{0}(500)$ into two pions, we may obtain a second, additional pole on the first Riemann sheet below the pion-pion threshold (i.e., a stable state can emerge). (ii) We perform a numerical study of the pole(s) of $a_{0}(1450)$ by using as an input the results obtained in the extended Linear Sigma Model (eLSM). Here, we do not find any additional pole besides the original one, thus we cannot obtain $a_{0}(980)$ as an emerging state. (iii) We finally demonstrate that, although the coupling constants in typical effective models might be large, the next-to-leading-order contribution to the decay amplitude is usually small and can be n...
Spin-orbit ferromagnetic resonance
Ferguson, Andrew
2013-03-01
In conventional magnetic resonance techniques the magnitude and direction of the oscillatory magnetic field are (at least approximately) known. This oscillatory field is used to probe the properties of a spin ensemble. Here, I will describe experiments that do the inverse. I will discuss how we use a magnetic resonance technique to map out the current-induced effective magnetic fields in the ferromagnetic semiconductors (Ga,Mn)As and (Ga,Mn)(As,P). These current-induced fields have their origin in the spin-orbit interaction. Effective magnetic fields are observed with symmetries which resemble the Dresselhaus and Rashba spin-orbit interactions and which depend on the diagonal and off-diagonal strain respectively. Ferromagnetic semiconductor materials of different strains, annealing conditions and concentrations are studied and the results compared with theoretical calculations. Our original study measured the rectification voltage coming from the product of the oscillatory magnetoresistance, during magnetisation precession, and the alternating current. More recently we have developed an impedance matching technique which enables us to extract microwave voltages from these high resistance (10 k Ω) samples. In this way we measure the microwave voltage coming from the product of the oscillating magneto-resistance and a direct current. The direct current is observed to affect the magnetisation precession, indicating that anti-damping as well as field-like torques can originate from the spin-orbit interaction.
Effective resonant stability of Mercury
Sansottera, M; Lemaître, A
2015-01-01
Mercury is the unique known planet that is situated in a 3:2 spin-orbit resonance nowadays. Observations and models converge to the same conclusion: the planet is presently deeply trapped in the resonance and situated at the Cassini state $1$, or very close to it. We investigate the complete non-linear stability of this equilibrium, with respect to several physical parameters, in the framework of Birkhoff normal form and Nekhoroshev stability theory. We use the same approach adopted for the 1:1 spin-orbit case with a peculiar attention to the role of Mercury's non negligible eccentricity. The selected parameters are the polar moment of inertia, the Mercury's inclination and eccentricity and the precession rates of the perihelion and node. Our study produces a bound to both the latitudinal and longitudinal librations (of 0.1 radians) for a long but finite time (greatly exceeding the age of the solar system). This is the so-called effective stability time. Our conclusion is that Mercury, placed inside the 3:2 s...
Threshold enhancement of diphoton resonances
Bharucha, Aoife; Djouadi, Abdelhak; Goudelis, Andreas
2016-10-01
We revisit a mechanism to enhance the decay width of (pseudo-)scalar resonances to photon pairs when the process is mediated by loops of charged fermions produced near threshold. Motivated by the recent LHC data, indicating the presence of an excess in the diphoton spectrum at approximately 750 GeV, we illustrate this threshold enhancement mechanism in the case of a 750 GeV pseudoscalar boson A with a two-photon decay mediated by a charged and uncolored fermion having a mass at the 1/2MA threshold and a small decay width, photons predominantly through loops of charginos with masses close to 1/2MA and ii) a two Higgs doublet model in which A is again produced by gluon fusion but decays into photons through loops of vector-like charged heavy leptons. In both these scenarios, while the mass of the charged fermion has to be adjusted to be extremely close to half of the A resonance mass, the small total widths are naturally obtained if only suppressed three-body decay channels occur. Finally, the implications of some of these scenarios for dark matter are discussed.
Resonant spectra of quadrupolar anions
Fossez, K.; Mao, Xingze; Nazarewicz, W.; Michel, N.; Garrett, W. R.; Płoszajczak, M.
2016-09-01
In quadrupole-bound anions, an extra electron is attached at a sufficiently large quadrupole moment of a neutral molecule, which is lacking a permanent dipole moment. The nature of the bound states and low-lying resonances of such anions is of interest for understanding the threshold behavior of open quantum systems in general. In this work, we investigate the properties of quadrupolar anions as halo systems, the formation of rotational bands, and the transition from a subcritical to supercritical electric quadrupole moment. We solve the electron-plus-rotor problem using a nonadiabatic coupled-channel formalism by employing the Berggren ensemble, which explicitly contains bound states, narrow resonances, and the scattering continuum. The rotor is treated as a linear triad of point charges with zero monopole and dipole moments and nonzero quadrupole moment. We demonstrate that binding energies and radii of quadrupolar anions strictly follow the scaling laws for two-body halo systems. Contrary to the case of dipolar anions, ground-state band of quadrupolar anions smoothly extend into the continuum, and many rotational bands could be identified above the detachment threshold. We study the evolution of a bound state of an anion as it dives into the continuum at a critical quadrupole moment and we show that the associated critical exponent is α =2 . Everything considered, quadrupolar anions represent a perfect laboratory for the studies of marginally bound open quantum systems.
Threshold enhancement of diphoton resonances
Directory of Open Access Journals (Sweden)
Aoife Bharucha
2016-10-01
Full Text Available We revisit a mechanism to enhance the decay width of (pseudo-scalar resonances to photon pairs when the process is mediated by loops of charged fermions produced near threshold. Motivated by the recent LHC data, indicating the presence of an excess in the diphoton spectrum at approximately 750 GeV, we illustrate this threshold enhancement mechanism in the case of a 750 GeV pseudoscalar boson A with a two-photon decay mediated by a charged and uncolored fermion having a mass at the 12MA threshold and a small decay width, <1 MeV. The implications of such a threshold enhancement are discussed in two explicit scenarios: i the Minimal Supersymmetric Standard Model in which the A state is produced via the top quark mediated gluon fusion process and decays into photons predominantly through loops of charginos with masses close to 12MA and ii a two Higgs doublet model in which A is again produced by gluon fusion but decays into photons through loops of vector-like charged heavy leptons. In both these scenarios, while the mass of the charged fermion has to be adjusted to be extremely close to half of the A resonance mass, the small total widths are naturally obtained if only suppressed three-body decay channels occur. Finally, the implications of some of these scenarios for dark matter are discussed.
Single-molecule stochastic resonance
Hayashi, K; Manosas, M; Huguet, J M; Ritort, F; 10.1103/PhysRevX.2.031012
2012-01-01
Stochastic resonance (SR) is a well known phenomenon in dynamical systems. It consists of the amplification and optimization of the response of a system assisted by stochastic noise. Here we carry out the first experimental study of SR in single DNA hairpins which exhibit cooperatively folding/unfolding transitions under the action of an applied oscillating mechanical force with optical tweezers. By varying the frequency of the force oscillation, we investigated the folding/unfolding kinetics of DNA hairpins in a periodically driven bistable free-energy potential. We measured several SR quantifiers under varied conditions of the experimental setup such as trap stiffness and length of the molecular handles used for single-molecule manipulation. We find that the signal-to-noise ratio (SNR) of the spectral density of measured fluctuations in molecular extension of the DNA hairpins is a good quantifier of the SR. The frequency dependence of the SNR exhibits a peak at a frequency value given by the resonance match...
Spectrally resolved resonant propulsion of dielectric microspheres
Li, Yangcheng; Limberopoulos, Nicholaos I; Urbas, Augustine M; Astratov, Vasily N
2015-01-01
Use of resonant light forces opens up a unique approach to high-volume sorting of microspherical resonators with much higher uniformity of resonances compared to that in coupled-cavity structures obtained by the best semiconductor technologies. In this work, the spectral response of the propulsion forces exerted on polystyrene microspheres near tapered microfibers is directly observed. The measurements are based on the control of the detuning between the tunable laser and internal resonances in each sphere with accuracy higher than the width of the resonances. The measured spectral shape of the propulsion forces correlates well with the whispering-gallery mode resonances in the microspheres. The existence of a stable radial trap for the microspheres propelled along the taper is demonstrated. The giant force peaks observed for 20-{\\mu}m spheres are found to be in a good agreement with a model calculation demonstrating an efficient use of the light momentum for propelling the microspheres.
Developing accelerometer based on graphene nanoribbon resonators
Energy Technology Data Exchange (ETDEWEB)
Kang, Jeong Won, E-mail: jwkang@ut.ac.kr [Department of Computer Engineering, Korea National University of Transportation, Chungju 380-702 (Korea, Republic of); Lee, Jun Ha, E-mail: junha@smu.ac.kr [Department of Computer System Engineering, Sangmyung University, Chonan 330-720 (Korea, Republic of); Hwang, Ho Jung, E-mail: hjhwang@cau.ac.kr [School of Electrical and Electronic Engineering, Chung-Ang University, Seoul 156-756 (Korea, Republic of); Kim, Ki-Sub, E-mail: kks1114@ut.ac.kr [Department of Chemical and Biological Engineering, Korea National University of Transportation, Chungju 380-702 (Korea, Republic of)
2012-10-01
We investigated an ultrahigh sensitive accelerometer based on graphene nanoribbon resonators. Sensing acceleration can be made by their resonance frequency shift and/or their capacitance change. Schematics and the static properties were introduced and the dynamic properties were investigated via classical molecular dynamics simulation. As the acceleration increased, the oscillations of the deflections were going dramatically faster and the mean deflections increased, then the capacitance continually varied with large amplitudes and the resonance frequencies linearly increased in a log–log scale by power regression. The energy loss decreased with increasing time, and the average quality factors were dramatically reduced with increasing acceleration. -- Highlights: ► Ultrahigh sensitive accelerometer based on graphene nanoribbon resonators. ► Sensing acceleration by resonance frequency shift and/or capacitance change. ► Resonance frequencies linearly increased with increasing acceleration in a log–log scale. ► Quality factors were dramatically reduced with increasing acceleration.
Bimaterial Thermal Compensators for WGM Resonators
Savchenkov, Anatoliy; Yu, Nan; Maleki, Lute; Iltchenko, Vladimir; Strekalov, Dmitry
2008-01-01
Bimaterial thermal compensators have been proposed as inexpensive means of preventing (to first order) or reducing temperature-related changes in the resonance frequencies of whispering-gallery-mode (WGM) optical resonators. A bimaterial compensator would apply, to a WGM resonator, a pressure that would slightly change the shape of the resonator and thereby change its resonance frequencies. Through suitable choice of the compensator dimensions and materials, it should be possible to make the temperature dependence of the pressure-induced frequency shift equal in magnitude and opposite in sign to the temperature dependence of the frequency shift of the uncompensated resonator so that, to first order, a change in temperature would cause zero net change in frequency.
Surface acoustic wave mode conversion resonator
Martin, S. J.; Gunshor, R. L.; Melloch, M. R.; Datta, S.; Pierret, R. F.
1983-08-01
The fact that a ZnO-on-Si structure supports two distinct surface waves, referred to as the Rayleigh and the Sezawa modes, if the ZnO layer is sufficiently thick is recalled. A description is given of a unique surface wave resonator that operates by efficiently converting between the two modes at the resonant frequency. Since input and output coupling is effected through different modes, the mode conversion resonator promises enhanced out-of-band signal rejection. A Rayleigh wave traversing the resonant cavity in one direction is reflected as a Sezawa wave. It is pointed out that the off-resonance rejection of the mode conversion resonator could be enhanced by designing the transducers to minimize the level of cross coupling between transducers and propagating modes.
Fano resonances from gradient-index metamaterials.
Xu, Yadong; Li, Sucheng; Hou, Bo; Chen, Huanyang
2016-01-27
Fano resonances - resonant scattering features with a characteristic asymmetric profile - have generated much interest, due to their extensive and valuable applications in chemical or biological sensors, new types of optical switches, lasers and nonlinear optics. They have been observed in a wide variety of resonant optical systems, including photonic crystals, metamaterials, metallic gratings and nanostructures. In this work, a waveguide structure is designed by employing gradient-index metamaterials, supporting strong Fano resonances with extremely sharp spectra. As the changes in the transmission spectrum originate from the interaction of guided modes from different channels, instead of resonance structures or metamolecules, the Fano resonances can be observed for both transverse electric and transverse magnetic polarizations. These findings are verified by fine agreement with analytical calculations and experimental results at microwave, as well as simulated results at near infrared frequencies.
Secular resonances with Ceres and Vesta
Tsirvoulis, Georgios
2016-01-01
In this work we explore dynamical perturbations induced by the massive asteroids Ceres and Vesta on main-belt asteroids through secular resonances. First we determine the location of the linear secular resonances with Ceres and Vesta in the main belt, using a purely numerical technique. Then we use a set of numerical simulations of fictitious asteroids to investigate the importance of these secular resonances in the orbital evolution of main-belt asteroids. We found, evaluating the magnitude of the perturbations in the proper elements of the test particles, that in some cases the strength of these secular resonances is comparable to that of known non-linear secular resonances with the giant planets. Finally we explore the asteroid families that are crossed by the secular resonances we studied, and identified several cases where the latter seem to play an important role in their post-impact evolution.
Torque-mixing Magnetic Resonance Spectroscopy
Losby, Joseph; Fani Sani, Fatemeh; Grandmont, Dylan; Diao, Zhu; Belov, Miro; Burgess, Jacob; Compton, Shawn; Hiebert, Wayne; Vick, Doug; Mohammad, Kaveh; Salimi, Elham; Bridges, Gregory; Thomson, Douglas; Freeman, Mark
A universal, mechanical torque method for magnetic resonance spectroscopy is presented. In analogy to resonance detection by induction, a signal proportional to the transverse component of a precessing dipole moment can be measured as a pure mechanical torque in broadband, frequency-swept spectroscopy. Comprehensive electron spin resonance of a single-crystal, mesoscopic yttrium iron garnet disk at room temperature are presented to demonstrate the method. The rich detail allows analysis of even complex 3D spin textures.
Humanitarian mine detection by acoustic resonance
Energy Technology Data Exchange (ETDEWEB)
Kercel, S.W.
1998-03-01
The JASON Committee at MITRE Corp. was tasked by DARPA to inquire into suitable technologies for humanitarian mine detection. Acoustic resonance was one of the very few technologies that the JASONs determined might be promising for the task, but was as yet unexplored at the time that they conducted their inquiry. The objective of this Seed Money investigation into acoustic resonance was to determine if it would be feasible to use acoustic resonance to provide an improvement to present methods for humanitarian mine detection. As detailed in this report, acoustic resonance methods do not appear to be feasible for this task. Although acoustic resonant responses are relatively easy to detect when they exist, they are very difficult to excite by the non-contact means that must be used for buried objects. Despite many different attempts, this research did not discover any practical means of using sound to excite resonant responses in objects known to have strong resonances. The shaker table experiments did see an effect that might be attributable to the resonance of the object under test, but the effect was weak, and exploited the a priori knowledge of the resonant frequency of the object under test to distinguish it from the background. If experiments that used objects known to have strong acoustic resonances produced such marginal results, this does not seem to be a practical method to detect objects with weak resonances or non-existent resonances. The results of this work contribute to the ORNL countermine initiative. ORNL is exploring several unconventional mine detection technologies, and is proposed to explore others. Since this research has discovered some major pitfalls in non-metallic mine detection, this experience will add realism to other strategies proposed for mine detection technologies. The experiment provided hands-on experience with inert plastic mines under field conditions, and gives ORNL additional insight into the problems of developing practical
Resonance ionization scheme development for europium
Chrysalidis, K; Fedosseev, V N; Marsh, B A; Naubereit, P; Rothe, S; Seiffert, C; Kron, T; Wendt, K
2017-01-01
Odd-parity autoionizing states of europium have been investigated by resonance ionization spectroscopy via two-step, two-resonance excitations. The aim of this work was to establish ionization schemes specifically suited for europium ion beam production using the ISOLDE Resonance Ionization Laser Ion Source (RILIS). 13 new RILIS-compatible ionization schemes are proposed. The scheme development was the first application of the Photo Ionization Spectroscopy Apparatus (PISA) which has recently been integrated into the RILIS setup.
Pressure effects in multiple resonant multiphoton transitions
Maïnos, C.; Le Duff, Y.; Castex, M. C.; Boursey, E.
1989-02-01
Although the rotational structure of a multiphoton process generally remains unaltered over a large range of gas pressure, this is not the case when multiple resonances are present. The rotational structure observed through intermediate rotational levels in a multiphoton process depends strongly on the resonance conditions. We show, for the NO molecule, that this structure changes drastically when the resonance conditions are modified by intermolecular collisions.
Monostable array-enhanced stochastic resonance.
Lindner, J F; Breen, B J; Wills, M E; Bulsara, A R; Ditto, W L
2001-05-01
We present a simple nonlinear system that exhibits multiple distinct stochastic resonances. By adjusting the noise and coupling of an array of underdamped, monostable oscillators, we modify the array's natural frequencies so that the spectral response of a typical oscillator in an array of N oscillators exhibits N-1 different stochastic resonances. Such families of resonances may elucidate and facilitate a variety of noise-mediated cooperative phenomena, such as noise-enhanced propagation, in a broad class of similar nonlinear systems.
Emittance growths in resonance crossing at FFAGs
Energy Technology Data Exchange (ETDEWEB)
Ng, K.Y.; /Fermilab; Pang, X.; Wang, F.; Wang, X.; Lee, S.Y.; /Indiana U.
2007-10-01
Scaling laws of the emittance growth for a beam crossing the 6th-order systematic space-charge resonances and the random-octupole driven 4th-order resonance are obtained by numerical multi-particle simulations. These laws can be important in setting the minimum acceleration rate and maximum tolerable resonance strength for the design of non-scaling fixed-field alternating gradient accelerators.
CMOS-compatible athermal silicon microring resonators.
Guha, Biswajeet; Kyotoku, Bernardo B C; Lipson, Michal
2010-02-15
We propose a new class of resonant silicon optical devices, consisting of a ring resonator coupled to a Mach-Zehnder interferometer, which is passively temperature compensated by tailoring the optical mode confinement in the waveguides. We demonstrate operation of the device over a wide temperature range of 80 degrees. The fundamental principle behind this work can be extended to other photonic devices based on resonators such as modulators, routers, switches and filters.
Tunable coplanar waveguide resonator with nanowires
Institute of Scientific and Technical Information of China (English)
周渝; 郏涛; 翟计全; 汪橙; 钟先茜; 曹志敏; 孙国柱; 康琳; 吴培亨
2015-01-01
A tunable superconducting half-wavelength coplanar waveguide resonator (CPWR) with Nb parallel nanowires ∼300 nm in width embedded in the center conductor was designed, fabricated, and measured. The frequency shift and the amplitude attenuation of the resonance peak under irradiation of 404-nm pulse laser were observed with different light powers at 4.2 K. The RF power supplied to such a CPWR can serve as current bias, which will affect the light response of the resonator.
Study of Mode Coupling on Coaxial Resonators
Institute of Scientific and Technical Information of China (English)
Rui Liu; Hong-Fu Li
2011-01-01
A study of mode coupling phenomenon of coaxial resonators has been conducted with theories.Through establishing the source-free transmission line equation,boundary conditions of the coaxial resonators with a corrugated inner conductor are analyzed.In the end,calculations are performed in a wide range of corrugation parameters for the resonator of the Karisruhe Institute of Technology (KIT) relevant coaxial gyrotron.
Polarization effects in recoil-induced resonances
Lazebnyi, D. B.; Brazhnikov, D. V.; Taichenachev, A. V.; Yudin, V. I.
2017-01-01
The effect of the field polarization on the amplitude of recoil-induced resonances (RIRs) is considered for laser-cooled free atoms and for atoms in a working magneto-optical trap (MOT). For all closed dipole transitions, explicit analytical expressions are obtained for the polarization dependence of the resonance amplitudes within a perturbation theory. Optimal polarization conditions are found for the observation of resonances.
Effective resonant interactions via a driving field
Energy Technology Data Exchange (ETDEWEB)
Klimov, A B [Departamento de FIsica, Universidad de Guadalajara, Revolucion 1500, Guadalajara 44420 (Mexico); Sainz, I [Departamento de FIsica, Universidad de Guadalajara, Revolucion 1500, Guadalajara 44420 (Mexico); Saavedra, C [Center for Quantum Optics and Quantum Information, Departamento de FIsica, Universidad de Concepcion, Casilla 160-C, Concepcion (Chile)
2004-11-01
Effective resonant quantum atom-field interactions are studied. These resonant interactions are induced by the presence of an external classical driving field. An adequate choice for frequencies of the driving field produces nonlinear effective Hamiltonians both for atom-field and for spin-spin interactions. It is shown that the exact numerical evolution for each resonance condition is well described by the corresponding effective Hamiltonian.
Acoustic resonance frequency locked photoacoustic spectrometer
Pilgrim, Jeffrey S.; Bomse, David S.; Silver, Joel A.
2003-09-09
A photoacoustic spectroscopy method and apparatus for maintaining an acoustic source frequency on a sample cell resonance frequency comprising: providing an acoustic source to the sample cell, the acoustic source having a source frequency; repeatedly and continuously sweeping the source frequency across the resonance frequency at a sweep rate; and employing an odd-harmonic of the source frequency sweep rate to maintain the source frequency sweep centered on the resonance frequency.
Micro string resonators as temperature sensors
DEFF Research Database (Denmark)
Larsen, T.; Schmid, S.; Boisen, A.
2013-01-01
The resonance frequency of strings is highly sensitive to temperature. In this work we have investigated the applicability of micro string resonators as temperature sensors. The resonance frequency of strings is a function of the tensile stress which is coupled to temperature by the thermal...... expansion of the string and the frame clamping it. The sensitivity improves when the length and pre-stress are reduced and the difference in thermal expansion, Young's modulus and resonant mode are increased. At low tensile stress, the sensitivity becomes highly dependent on temperature. The investigation...
The resonance phenomena and state of health
Directory of Open Access Journals (Sweden)
Sikura A.Y.
2010-06-01
Full Text Available The question of dependence of the state of health is examined from the resonance phenomena in the liquid environments of organism, roles herein physical loadings. It is rotined that resonance waves can compensate structural violations on a tissue, system levels. The oppressive operating is the same compensated on the organism of man. The physical loading in a complex with other external resonance phenomena causes substantial resonance vibrations in all systems of organism. It is necessary to take into account it on employments on physical education and to use all necessary rehabilitation facilities.
Magnetic resonance imaging of hemochromatosis arthropathy
Energy Technology Data Exchange (ETDEWEB)
Eustace, S. [Dept. of Radiology, Deaconess Hospital and Harvard Medical School, Boston, MA (United States); Buff, B. [Dept. of Radiology, Deaconess Hospital and Harvard Medical School, Boston, MA (United States); McCarthy, C. [The Inst. of Radiological Sciences, Mater Hospital, Dublin (Ireland); MacMathuana, P. [The Inst. of Radiological Sciences, Mater Hospital, Dublin (Ireland); Gilligan, P. [The Inst. of Radiological Sciences, Mater Hospital, Dublin (Ireland); Ennis, J.T. [The Inst. of Radiological Sciences, Mater Hospital, Dublin (Ireland)
1994-10-01
This study was undertaken to compare plain film radiography and magnetic resonance imaging in the assessment of hemochromatosis arthropathy of the knees of ten patients with a biopsy-proven diagnosis. Both modalities enabled visualisation of bony degenerative changes; magnetic resonance imaging enabled additional visualization of deformity of both cartilage and menisci. Magnetic resonance imaging failed reliably to confirm the presence of intra-articular iron in the patients studied. No correlation was observed between synovial fluid magnetic resonance signal values, corresponding serum ferritin levels, or the severity of the observed degenerative changes. (orig.)
Polarimetric Properties of Optically Resonant Nanostructures
Theisen, Michael John
Optically resonant nanostructures have been incorporated into a variety of devices used in a number of different fields. In this thesis, we explore optically resonant nanostructures in two forms. First we investigate a relatively new material, gallium implanted silicon (Si:Ga). We cover the fabrication process and experimentally find the optical properties as a function of both dose and wavelength. We then use the properties of this new material to create suspended arrays of Si:Ga nanowires, and determine their optical characteristics. In the second part of this thesis, we use more conventional materials and fabrication procedures to investigate the phase effects of guided mode resonators. We look at the spectral phase effects for a grating coupled silicon-on-insulator based guided mode resonator. We also look the angular phase effects of a surface plasmon polariton based guided mode resonator, comparing experimental results to theory calculated with rigorous coupled wave analysis for both cases. In addition, the guided mode resonance is modeled as a Fano resonance to gain insight into the functional form of the phase. Knowing the phase response of guided mode resonances may allow the creation of guided mode resonance based devices with higher sensitivity than traditional reflectance based devices.
Demographics of Resonances in Exoplanetary Systems
Ragozzine, Darin; Conaway, James L.; MacDonald, Mariah G.; Sallee, Victor
2016-10-01
NASA's Kepler Space Telescope has identified ~700 systems of multiple transiting exoplanets containing ~1700 planets. Most of these multi-transiting systems have 3-5 planets small planets with periods of roughly 5-50 days and are known as Systems with Tightly-spaced Inner Planets (STIPs). These information-rich exoplanetary systems have precisely measured period ratios which allows for the identification and characterization of orbital mean motion resonances. Improved understanding of the resonant populations will reveal much about the formation and evolution of planetary systems. Lissauer, Ragozzine, et al. 2011 found that most Kepler systems were not in resonance, but that there was a small excess of planets wide of resonance. We present new analyses that rigorously identify the frequency of planets in multiple resonances (including three-body resonances) and thus identify many specific new results on the demographics of resonances. We also show that the apparent over-abundance of resonances can be attributed to a difference in inclinations (potentially from dissipation) with implications for the true underlying frequency of resonant systems. We compare the period ratio distribution of Kepler (corrected for inclination biases) to Radial Velocity (RV) surveys and conclude that RV systems are often missing small intermediate planets. This has serious implications for the completeness of RV identification of planets in STIPs.
Q-enhanced racetrack micro-resonators
Chamorro-Posada, Pedro
2016-01-01
A Q enhancement strategy for racetrack micro -resonators is put forward. The design is based on the modification of the resonator geometry in order to mitigate the two main sources of radiation loss in the presence of curved waveguides: the couplings from the straight waveguides to the bent sections and the continuous loss at the curved waveguide sectors. Numerical calculations show over $100\\%$ improvement of the Q factor in silicon nitride resonators. At the same time, the modifications of the geometry do not affect the coupling properties of the resonators in integrated optical circuits.
RESONANCE RADIATION OF SUBMERGED INFINITE CYLINDRICAL SHELL
Institute of Scientific and Technical Information of China (English)
无
2002-01-01
The resonance sound radiation from submerged infinite elastic cylindrical shell, excited by internal harmonic line force, is investigated. The shell radiation power is presented in terms of resonant modal radiation derived from resonance radiation theory (RRT). The resonance radiation formulae are derived from classical Rayleigh normal mode solution, which are useful for understanding the mechanism of sound radiation from submerged shells. As an example, numerical calculation of a thin steel cylindrical shell is done by using these two methods. It seems that the results of RRT solutions are in good agreement with that of Rayleigh normal mode solutions.
Quantum communication between remote mechanical resonators
Felicetti, S.; Fedortchenko, S.; Rossi, R.; Ducci, S.; Favero, I.; Coudreau, T.; Milman, P.
2017-02-01
Mechanical resonators represent one of the most promising candidates to mediate the interaction between different quantum technologies, bridging the gap between efficient quantum computation and long-distance quantum communication. Here, we introduce an interferometric scheme where the interaction of a mechanical resonator with input-output quantum pulses is controlled by an independent classical drive. We design protocols for state teleportation and direct quantum state transfer, between distant mechanical resonators. The proposed device, feasible with state-of-the-art technology, can serve as a building block for the implementation of long-distance quantum networks of mechanical resonators.
Feshbach Resonances in Kerr Frequency Combs
Matsko, Andrey B
2014-01-01
We show that both the power and repetition rate of a frequency comb generated in a nonlinear ring resonator, pumped with continuous wave (cw) coherent light, are modulated. The modulation is brought about by the interaction of the cw background with optical pulses excited in the resonator, and occurs in resonators with nonzero high-order chromatic dispersion and wavelength-dependent quality factor. The modulation frequency corresponds to the detuning of the pump frequency from the eigenfrequency of the pumped mode in the resonator.
Composite spin-1 resonances at the LHC
Low, Matthew; Wang, Lian-Tao
2015-01-01
In this paper, we discuss the signal of composite spin-1 resonances at the LHC. Motivated by the possible observation of a diboson resonance in the 8 TeV LHC data, we demonstrate that vector resonances from composite Higgs models are able to describe the data. We pay particular attention to the role played by fermion partial compositeness, which is a common feature in composite Higgs models. The parameter space that is both able to account for the diboson excess and passes electroweak precision and flavor tests is explored. Finally, we make projections for signals of such resonances at the 13 TeV run of the LHC.
Few-body resonances in light nuclei
Csoto, A
2000-01-01
We have localized several few-body resonances in light nuclei, using methods which can properly handle two- or three-body resonant states. Among other results, we predict the existence of a three-neutron resonance, small spin-orbit splittings between the low-lying states in He-5 and Li-5, the nonexistence of the soft dipole resonance in He-6, new 1+ states in Li-8 and B-8, and the presence of a nonlinear amplification phenomenon in the 0+_2 state of C-12.
Scalar-Pseudoscalar scattering and pseudoscalar resonances
Albaladejo, M
2010-01-01
The interactions between the f_0(980) and a_0(980) scalar resonances and the lightest pseudoscalar mesons are studied. We first obtain the interacting kernels, without including any ad hoc free parameter, because the lightest scalar resonances are dynamically generated. These kernels are unitarized, giving the final amplitudes, which generate pseudoscalar resonances, associated with the K(1460), \\pi(1300), \\pi(1800), \\eta(1475) and X(1835). We also consider the exotic channels with I=3/2 and I^G=1^+ quantum numbers. The former could be also resonant in agreement with a previous prediction.
Measurement of global and local resonance terms
Tomás, R; Calaga, R; Fischer, W; Franchi, A; Rumolo, Giovanni
2005-01-01
Recently, resonance driving terms were successfully measured in the CERN SPS and the BNL RHIC from the Fourier spectrum of beam position monitor (BPM) data. Based on these measurements a new analysis has been derived to extract truly local observables from BPM data. These local observables are called local resonance terms since they share some similarities with the global resonance terms. In this paper we derive these local terms analytically and present experimental measurements of sextupolar global and local resonance terms in RHIC. Nondestructive measurements of these terms using ac dipoles are also presented.
DEFF Research Database (Denmark)
Johannessen, Christian; Abdali, Salim; White, Peter C.
2007-01-01
to resonance enhanced skeletal porphyrin vibrations, more pronounced than any contribution from the protein back-bone. Combining the intrinsic resonance enhancement of cytochrome c with surface plasmon enhancement by colloidal silver particles, the Surface Enhanced Resonance Raman Scattering (SERRS) and Chiral......, while some disparities were observed between the resonance ROA and ChERS spectra. The difference can be ascribed perturbations of the physical properties of the protein upon adhesion to the surface of the silver colloids....
From QCD to Physical Resonances
Bolton, Daniel R; Wilson, David J
2016-01-01
In this talk, we present the first chiral extrapolation of a resonant scattering amplitude obtained from lattice QCD. Finite-volume spectra, determined by the Hadron Spectrum Collaboration at $m_\\pi = 236$ MeV, for the isotriplet $\\pi\\pi$ channel are analyzed using the L\\"uscher method to determine the infinite-volume scattering amplitude. Unitarized Chiral Perturbation Theory is then used to extrapolate the scattering amplitude to the physical light quark masses. The viability of this procedure is demonstrated by its agreement with the experimentally determined scattering phase shift up to center-of-mass energies of 1.2 GeV. Finally, we analytically continue the amplitude to the complex plane to obtain the $\\rho$-pole at $\\left[755(2)(1)\\left({}^{20}_{02}\\right) - \\frac{i}{2} 129(3)(1)\\left({}^7_1\\right)\\right]$ MeV.
Second order resonant Raman scattering
Energy Technology Data Exchange (ETDEWEB)
Garcia-Cristobal, A.; Catarero, A. [Valencia Univ. (Spain). Dept. de Fisica Aplicada; Trallero-Giner, C. [Instituto Politecnico Nacional, Mexico City (Mexico). Centro de Investigacion y de Estudios Avanzados
1996-03-01
A theoretical model for resonant Raman scattering by two optical phonons in zincblende-type semiconductors is presented. The effect of Coulomb interaction between electrons and holes is taken into account by introducing discrete and continuous excitonic intermediate states. The model can be applied for laser frequencies below and above the band gap. We consider deformation potential and Froehlich interaction for the electron-one-phonon coupling. The absolute value of the scattering efficiency is evaluated for the L-O-phonons, TO-plus LO-phonon and two-TO-photons Raman processes, around the E{sub o} absorption edge of II-VI compound semiconductors. Comparison with the electron-hole uncorrelated theory and experimental data emphasizes the role if the excitonic effects. (author). 10 refs., 2 figs.
A resonance mechanism of earthquakes
Flambaum, V V
2015-01-01
It had been observed in [1] that there are periodic 4-6 hours pulses of ? 200 ?Hz seismogravita- tional oscillations ( SGO ) before 95 % of powerful earthquakes. We explain this by beating between an oscillation eigenmode of a whole tectonic plate and a local eigenmode of an active zone which tranfers the oscillation energy from the tectonic plate to the active zone causing the eathrquake. Oscillation frequencies of the plate and ones of the active zone are tuned to a resonance by an additional pressure applied to the active zone due to collision of neighboring plates or convection in the upper mantia (plume). Corresponding theory may be used for short-term prediction of the earthquakes and tsunami.
Resonant magnetic fields from inflation
Byrnes, Christian T; Jain, Rajeev Kumar; Urban, Federico R
2012-01-01
We propose a novel scenario to generate primordial magnetic fields during inflation induced by an oscillating coupling of the electromagnetic field to the inflaton. This resonant mechanism has two key advantages over previous proposals. First of all, it generates a narrow band of magnetic fields at any required wavelength, thereby allaying the usual problem of a strongly blue spectrum and its associated backreaction. Secondly, it avoids the need for a strong coupling as the coupling is oscillating rather than growing or decaying exponentially. Despite these major advantages, we find that the backreaction is still far too large during inflation if the generated magnetic fields are required to have a strength of ${\\cal O}(10^{-15}\\, \\Gauss)$ today on observationally interesting scales. We provide a more general no-go argument, proving that this problem will apply to any model in which the magnetic fields are generated on subhorizon scales and freeze after horizon crossing.
Introduction to Nuclear Magnetic Resonance
Manatt, Stanley L.
1985-01-01
The purpose of this paper is to try to give a short overview of what the status is on nuclear magnetic resonance (NMR). It's a subject where one really has to spend some time to look at the physics in detail to develop a proper working understanding. I feel it's not appropriate to present to you density matrices, Hamiltonians of all sorts, and differential equations representing the motion of spins. I'm really going to present some history and status, and show a few very simple concepts involved in NMR. It is a form of radio frequency spectroscopy and there are a great number of nuclei that can be studied very usefully with the technique. NMR requires a magnet, a r.f. transmitter/receiver system, and a data acquisition system.
Piezoelectric Resonator with Two Layers
Stephanou, Philip J. (Inventor); Black, Justin P. (Inventor)
2013-01-01
A piezoelectric resonator device includes: a top electrode layer with a patterned structure, a top piezoelectric layer adjacent to the top layer, a middle metal layer adjacent to the top piezoelectric layer opposite the top layer, a bottom piezoelectric layer adjacent to the middle layer opposite the top piezoelectric layer, and a bottom electrode layer with a patterned structure and adjacent to the bottom piezoelectric layer opposite the middle layer. The top layer includes a first plurality of electrodes inter-digitated with a second plurality of electrodes. A first one of the electrodes in the top layer and a first one of the electrodes in the bottom layer are coupled to a first contact, and a second one of the electrodes in the top layer and a second one of the electrodes in the bottom layer are coupled to a second contact.
Regular Motions of Resonant Asteroids
Ferraz-Mello, S.
1990-11-01
RESUMEN. Se revisan resultados analiticos relativos a soluciones regulares del problema asteroidal eliptico promediados en la vecindad de una resonancia con jupiten Mencionamos Ia ley de estructura para libradores de alta excentricidad, la estabilidad de los centros de liberaci6n, las perturbaciones forzadas por la excentricidad de jupiter y las 6rbitas de corotaci6n. ABSTRAC This paper reviews analytical results concerning the regular solutions of the elliptic asteroidal problem averaged in the neighbourhood of a resonance with jupiter. We mention the law of structure for high-eccentricity librators, the stability of the libration centers, the perturbations forced by the eccentricity ofjupiter and the corotation orbits. Key words: ASThROIDS
Enhanced responsivity resonant RF photodetectors.
Liu, R; Dev, S; Zhong, Y; Lu, R; Streyer, W; Allen, J W; Allen, M S; Wenner, B R; Gong, S; Wasserman, D
2016-11-14
The responsivity of room-temperature, semiconductor-based photodetectors consisting of resonant RF circuits coupled to microstrip buslines is investigated. The dependence of the photodetector response on the semiconductor material and RF circuit geometry is presented, as is the detector response as a function of the spatial position of the incident light. We demonstrate significant improvement in detector response by choice of photoconductive material, and for a given material, by positioning our optical signal to overlap with positions of RF field enhancement. Design of RF circuits with strong field enhancement are demonstrated to further improve detector response. The improved detector response demonstrated offers opportunities for applications in RF photonics, materials metrology, or single read-out multiplexed detector arrays.
Multi-resonance split ring resonator structures at sub-terahertz frequencies
Galal, Hossam
2016-01-01
This paper reports on the computational development of novel architectures of multi-resonance Split Ring Resonators (SRRs), for efficient manipulation of Terahertz (THz) frequency beams. The conceived resonators are based on both a capacitive and inductive scheme. Simulation results have been obtained for a 60 GHz to 240 GHz operational bandwidth.
Neutron Resonance Parameters for Ra-226 (Radium)
Sukhoruchkin, S. I.; Soroko, Z. N.
This document is part of the Supplement containing the complete sets of data of Volume 24 `Neutron Resonance Parameters' of Landolt-Börnstein - Group I `Elementary Particles, Nuclei and Atoms'. It provides the neutron resonance parameters for the isotope Ra-226 (Radium).
Magnetic resonance imaging of the prostate
DEFF Research Database (Denmark)
Iversen, P; Kjaer, L; Thomsen, C
1988-01-01
Magnetic resonance imaging offers new possibilities in investigation of the prostate gland. Current results of imaging and tissue discrimination in the evaluation of prostatic disease are reviewed. Magnetic resonance imaging may be useful in the staging of carcinoma of the prostate....
Magnetic resonance imaging of the prostate
DEFF Research Database (Denmark)
Iversen, P; Kjaer, L; Thomsen, C
1987-01-01
Magnetic resonance imaging offers new possibilities in the investigation of the prostate. The current results of imaging and tissue discrimination in the evaluation of prostatic disease are reviewed. Magnetic resonance imaging may be of value in the staging of carcinoma of the prostate....
Simple classical approach to spin resonance phenomena
DEFF Research Database (Denmark)
Gordon, R A
1977-01-01
A simple classical method of describing spin resonance in terms of the average power absorbed by a spin system is discussed. The method has several advantages over more conventional treatments, and a number of important spin resonance phenomena, not normally considered at the introductory level...
Higher order resonances in dynamical systems
Contopoulos, George
1978-01-01
It is shown that the appearance of higher order resonances (that produce higher order islands on a surface of section), is not an indication of non-integrability. Examples are given and a method is described for constructing integrable Hamiltonians with higher order resonances. (11 refs).
Chemical Principles Revisited. Proton Magnetic Resonance Spectroscopy.
McQuarrie, Donald A.
1988-01-01
Discusses how to interpret nuclear magnetic resonance (NMR) spectra and how to use them to determine molecular structures. This discussion is limited to spectra that are a result of observation of only the protons in a molecule. This type is called proton magnetic resonance (PMR) spectra. (CW)
Effect of Systematic Resonance on DBD Device
Institute of Scientific and Technical Information of China (English)
无
2005-01-01
Abnormal phenomena that discharge performance declines with the increase in the frequency of power supply have been observed in many DBD devices. DBD systematic resonance formed by transformer leakage induction and equivalent capacitance of the dielectric layer is a key factor causing such abnormal phenomena. Therefore, the parameters of a DBD device should be optimized to avoid resonance damage and improve DBD discharge characteristics.
Optimal resonant control of flexible structures
DEFF Research Database (Denmark)
Krenk, Steen; Høgsberg, Jan Becker
2009-01-01
When introducing a resonant controller for a particular vibration mode in a structure this mode splits into two. A design principle is developed for resonant control based oil equal damping of these two modes. First the design principle is developed for control of a system with a single degree of...
On the nature of the Roper resonance
Alvarez-Ruso, L
2010-01-01
The lightest N* state, N(1440) P11, also known as Roper resonance, has puzzled physicists for decades. A large variety of theoretical models aimed to understand its properties have been proposed. Some of them are briefly reviewed here, together with the hadronic processes where the Roper resonance is revealed or plays an important role.
Functional Magnetic Resonance Imaging and Pediatric Anxiety
Pine, Daniel S.; Guyer, Amanda E.; Leibenluft, Ellen; Peterson, Bradley S.; Gerber, Andrew
2008-01-01
The use of functional magnetic resonance imaging in investigating pediatric anxiety disorders is studied. Functional magnetic resonance imaging can be utilized in demonstrating parallels between the neural architecture of difference in anxiety of humans and the neural architecture of attention-orienting behavior in nonhuman primates or rodents.…
Matrix methods for bare resonator eigenvalue analysis.
Latham, W P; Dente, G C
1980-05-15
Bare resonator eigenvalues have traditionally been calculated using Fox and Li iterative techniques or the Prony method presented by Siegman and Miller. A theoretical framework for bare resonator eigenvalue analysis is presented. Several new methods are given and compared with the Prony method.
Thermally actuated resonant silicon crystal nanobalances
Hajjam, Arash
As the potential emerging technology for next generation integrated resonant sensors and frequency references as well as electronic filters, micro-electro-mechanical resonators have attracted a lot of attention over the past decade. As a result, a wide variety of high frequency micro/nanoscale electromechanical resonators have recently been presented. MEMS resonators, as low-cost highly integrated and ultra-sensitive mass sensors, can potentially provide new opportunities and unprecedented capabilities in the area of mass sensing. Such devices can provide orders of magnitude higher mass sensitivity and resolution compared to Film Bulk Acoustic resonators (FBAR) or the conventional quartz and Surface Acoustic Wave (SAW) resonators due to their much smaller sizes and can be batch-fabricated and utilized in highly integrated large arrays at a very low cost. In this research, comprehensive experimental studies on the performance and durability of thermally actuated micromechanical resonant sensors with frequencies up to tens of MHz have been performed. The suitability and robustness of the devices have been demonstrated for mass sensing applications related to air-borne particles and organic gases. In addition, due to the internal thermo-electro-mechanical interactions, the active resonators can turn some of the consumed electronic power back into the mechanical structure and compensate for the mechanical losses. Therefore, such resonators can provide self-sustained-oscillation without the need for any electronic circuitry. This unique property has been deployed to demonstrate a prototype self-sustained sensor for air-borne particle monitoring. I have managed to overcome one of the obstacles for MEMS resonators, which is their relatively poor temperature stability. This is a major drawback when compared with the conventional quartz crystals. A significant decrease of the large negative TCF for the resonators has been attained by doping the devices with a high
Coupling Bright and Dark Plasmonic Lattice Resonances
Rodriguez, S R K; Maes, B; Janssen, O T A; Vecchi, G; Rivas, J Gomez
2011-01-01
We demonstrate the coupling of bright and dark Surface Lattice Resonances (SLRs), which are collective Fano resonances in 2D plasmonic crystals. As a result of this coupling, a frequency stop-gap in the dispersion relation of SLRs is observed. The different field symmetries of the low and high frequency SLR bands lead to pronounced differences in their coupling to free space radiation. Standing waves of very narrow spectral width compared to localized surface plasmon resonances are formed at the high frequency band edge, while subradiant damping onsets at the low frequency band edge leading the resonance into darkness. We introduce a coupled oscillator analog to the plasmonic crystal, which serves to elucidate the physics of the coupled plasmonic resonances and to estimate very high quality factors (Q>700) for SLRs, which are the highest known for any 2D plasmonic crystal.
Coherent and incoherent processes in resonant photoemission
Energy Technology Data Exchange (ETDEWEB)
Magnuson, M.; Karis, O.; Weinelt, M. [Uppsala Univ. (Sweden)] [and others
1997-04-01
In this contribution the authors present the distinction between coherent and incoherent processes in resonant photoemission. As a first step they determine whether an autoionization process is photoemission-like or Auger-like. The discussion is based on measurements for a weakly bonded adsorption system, Ar/Pt(111). This type of system is well adapted to investigate these effects since it yields distinctly shifted spectral features depending on the nature of the process. After this, the question of resonance photoemission in metallic systems is addressed. This is done in connection with measurements at the 2p edges for Ni metal. Ni has been one of the prototype systems for resonant photoemission. The resonances have been discussed in connection with the strong correlation and d-band localization effects in this system. Based on the results some general comments about the appearance of resonant effects in metallic systems are made.
Hybrid simulation of electron cyclotron resonance heating
Ropponen, T; Suominen, P; Koponen, T K; Kalvas, T; Koivisto, H
2008-01-01
Electron Cyclotron Resonance (ECR) heating is a fundamentally important aspect in understanding the physics of Electron Cyclotron Resonance Ion Sources (ECRIS). Absorption of the radio frequency (RF) microwave power by electron heating in the resonance zone depends on many parameters including frequency and electric field strength of the microwave, magnetic field structure and electron and ion density profiles. ECR absorption has been studied in the past by e.g. modelling electric field behaviour in the resonance zone and its near proximity. This paper introduces a new ECR heating code that implements damping of the microwave power in the vicinity of the resonance zone, utilizes electron density profiles and uses right hand circularly polarized (RHCP) electromagnetic waves to simulate electron heating in ECRIS plasma.
Resonant superfluidity in an optical lattice
Energy Technology Data Exchange (ETDEWEB)
Titvinidze, Irakli; Hofstetter, Walter [Institut fuer Theoretische Physik, Johann Wolfgang Goethe-Universitaet, 60438 Frankfurt am Main (Germany); Snoek, Michiel [Institute for Theoretical Physics, Valckenierstraat 65, 1018 XE Amsterdam (Netherlands)
2010-07-01
We study a system of ultracold fermionic Potassium ({sup 40}K) atoms in a three-dimensional optical lattice in the neighborhood of an s-wave Feshbach resonance. Close to resonance, the system is described by a multi-band Bose-Fermi Hubbard Hamiltonian. We derive an effective lowest-band Hamiltonian in which the effect of the higher band is incorporated by a self-consistent mean-field approximation. The resulting model is solved by means of Generalized Dynamical Mean-Field Theory. In addition to the BEC/BCS crossover we find on the BCS side of the resonance a phase transition to a fermionic Mott insulator at half filling, induced by the repulsive fermionic background scattering length. We also calculate the critical temperature of the BEC/BCS-state across the resonance and find it to be minimal at resonance.
Observations of Snake Resonance in RHIC
Bai, Mei; Lee, Shyh-Yuan; Lin, Fanglei; MacKay, William; Ptitsyn, Vadim; Roser, Thomas; Tepikian, Steven
2005-01-01
Siberian snakes now become essential in the polarized proton acceleration. With proper configuration of Siberian snakes, the spin precession tune of the beam becomes $\\frac{1}{2}$ which avoids all the spin depolarizing resonance. However, the enhancement of the perturbations on the spin motion can still occur when the betatron tune is near some low order fractional numbers, called snake resonances, and the beam can be depolarized when passing through the resonance. The snake resonances have been confirmed in the spin tracking calculations, and observed in RHIC with polarized proton beam. Equipped with two full Siberian snakes in each ring, RHIC provides us a perfect facility for snake resonance studies. This paper presents latest experimental results. New insights are also discussed.
Silicon on Nothing Mems Electromechanical Resonator
Durand, C; Ancey, P; Judong, F; Talbot, A; Quenouillere, R; Renaud, D; Borel, S; Florin, B; Buchaillot, L
2008-01-01
The very significant growth of the wireless communication industry has spawned tremendous interest in the development of high performances radio frequencies (RF) components. Micro Electro Mechanical Systems (MEMS) are good candidates to allow reconfigurable RF functions such as filters, oscillators or antennas. This paper will focus on the MEMS electromechanical resonators which show interesting performances to replace SAW filters or quartz reference oscillators, allowing smaller integrated functions with lower power consumption. The resonant frequency depends on the material properties, such as Young's modulus and density, and on the movable mechanical structure dimensions (beam length defined by photolithography). Thus, it is possible to obtain multi frequencies resonators on a wafer. The resonator performance (frequency, quality factor) strongly depends on the environment, like moisture or pressure, which imply the need for a vacuum package. This paper will present first resonator mechanisms and mechanical...
Tunable Magnetic Resonance in Microwave Spintronics Devices
Chen, Yunpeng; Fan, Xin; Xie, Yunsong; Zhou, Yang; Wang, Tao; Wilson, Jeffrey D.; Simons, Rainee N.; Chui, Sui-Tat; Xiao, John Q.
2015-01-01
Magnetic resonance is one of the key properties of magnetic materials for the application of microwave spintronics devices. The conventional method for tuning magnetic resonance is to use an electromagnet, which provides very limited tuning range. Hence, the quest for enhancing the magnetic resonance tuning range without using an electromagnet has attracted tremendous attention. In this paper, we exploit the huge exchange coupling field between magnetic interlayers, which is on the order of 4000 Oe and also the high frequency modes of coupled oscillators to enhance the tuning range. Furthermore, we demonstrate a new scheme to control the magnetic resonance frequency. Moreover, we report a shift in the magnetic resonance frequency as high as 20 GHz in CoFe based tunable microwave spintronics devices, which is 10X higher than conventional methods.
Low-Loss Polymer-Based Ring Resonator for Resonant Integrated Optical Gyroscopes
Directory of Open Access Journals (Sweden)
Guang Qian
2014-01-01
Full Text Available Waveguide ring resonator is the sensing element of resonant integrated optical gyroscope (RIOG. This paper reports a polymer-based ring resonator with a low propagation loss of about 0.476 dB/cm for RIOG. The geometrical parameters of the waveguide and the coupler of the resonator were optimally designed. We also discussed the optical properties and gyroscope performance of the polymer resonator which shows a high quality factor of about 105. The polymer-based RIOG exhibits a limited sensitivity of less than 20 deg/h for the low and medium resolution navigation systems.
Directory of Open Access Journals (Sweden)
Yongyao Chen
2012-06-01
Full Text Available We investigate the resonant properties of high quality-factor membrane-based metamaterial resonators functioning in the terahertz regime. A number of factors, including the resonator geometry, dielectric loss, and most importantly the membrane thickness are found to extensively influence the resonance strength and quality factor of the sharp resonance. Further studies on the membrane thickness-dependent-sensitivity for sensing applications reveal that high quality-factor membrane metamaterials with a moderate thickness ranging from 10 to 50 μm are the most promising option towards developing realistic integrated terahertz filters and sensors.
Electron Spin Resonance at the Level of 1 04 Spins Using Low Impedance Superconducting Resonators
Eichler, C.; Sigillito, A. J.; Lyon, S. A.; Petta, J. R.
2017-01-01
We report on electron spin resonance measurements of phosphorus donors localized in a 200 μ m2 area below the inductive wire of a lumped element superconducting resonator. By combining quantum limited parametric amplification with a low impedance microwave resonator design, we are able to detect around 2 ×1 04 spins with a signal-to-noise ratio of 1 in a single shot. The 150 Hz coupling strength between the resonator field and individual spins is significantly larger than the 1-10 Hz coupling rates obtained with typical coplanar waveguide resonator designs. Because of the larger coupling rate, we find that spin relaxation is dominated by radiative decay into the resonator and dependent upon the spin-resonator detuning, as predicted by Purcell.
Lateral acoustic wave resonator comprising a suspended membrane of low damping resonator material
Olsson, Roy H.; El-Kady; , Ihab F.; Ziaei-Moayyed, Maryam; Branch; , Darren W.; Su; Mehmet F.,; Reinke; Charles M.,
2013-09-03
A very high-Q, low insertion loss resonator can be achieved by storing many overtone cycles of a lateral acoustic wave (i.e., Lamb wave) in a lithographically defined suspended membrane comprising a low damping resonator material, such as silicon carbide. The high-Q resonator can sets up a Fabry-Perot cavity in a low-damping resonator material using high-reflectivity acoustic end mirrors, which can comprise phononic crystals. The lateral overtone acoustic wave resonator can be electrically transduced by piezoelectric couplers. The resonator Q can be increased without increasing the impedance or insertion loss by storing many cycles or wavelengths in the high-Q resonator material, with much lower damping than the piezoelectric transducer material.
Study on resonance frequency distribution of high-overtone bulk acoustic resonators
Institute of Scientific and Technical Information of China (English)
ZHANG Hui; WANG Zuoqing; ZHANG Shuyi
2005-01-01
Based on the method of characterizing piezo-films by the resonance frequency distributions, the factors influencing the resonance frequency distribution of a High-overtone Bulk Acoustic Resonator (HBAR) consisting of a piezoelectric thin film with twoelectrodes and a substrate are studied. Some HBARs are simulated. The results manifest that changing the acoustic impedance ratio of the substrate to piezo-film the distribution of the space of the parallel resonance frequency and the effective electromechanical coupling factor are changed. When the fundamental mode of the piezo-film is at high frequency, changing the acoustic impedance ratio of the electrode to piezo-film and the thickness of the electrodes make the resonance frequency distribution of HBARs change. These results manifest that the HBARs can be resonant at specified frequencies by means of adjusting the factors affecting the resonance frequency distribution.
Ionization Cooling using Parametric Resonances
Energy Technology Data Exchange (ETDEWEB)
Johnson, Rolland P.
2008-06-07
Ionization Cooling using Parametric Resonances was an SBIR project begun in July 2004 and ended in January 2008 with Muons, Inc., (Dr. Rolland Johnson, PI), and Thomas Jefferson National Accelerator Facility (JLab) (Dr. Yaroslav Derbenev, Subcontract PI). The project was to develop the theory and simulations of Parametric-resonance Ionization Cooling (PIC) so that it could be used to provide the extra transverse cooling needed for muon colliders in order to relax the requirements on the proton driver, reduce the site boundary radiation, and provide a better environment for experiments. During the course of the project, the theoretical understanding of PIC was developed and a final exposition is ready for publication. Workshops were sponsored by Muons, Inc. in May and September of 2007 that were devoted to the PIC technique. One outcome of the workshops was the interesting and somewhat unexpected realization that the beam emittances using the PIC technique can get small enough that space charge forces can be important. A parallel effort to develop our G4beamline simulation program to include space charge effects was initiated to address this problem. A method of compensating for chromatic aberrations by employing synchrotron motion was developed and simulated. A method of compensating for spherical aberrations using beamline symmetry was also developed and simulated. Different optics designs have been developed using the OptiM program in preparation for applying our G4beamline simulation program, which contains all the power of the Geant4 toolkit. However, no PIC channel design that has been developed has had the desired cooling performance when subjected to the complete G4beamline simulation program. This is believed to be the consequence of the difficulties of correcting the aberrations associated with the naturally large beam angles and beam sizes of the PIC method that are exacerbated by the fringe fields of the rather complicated channel designs that have been
Directory of Open Access Journals (Sweden)
Billy W. Day
2010-11-01
Full Text Available Biosensors have been used extensively in the scientific community for several purposes, most notably to determine association and dissociation kinetics, protein-ligand, protein-protein, or nucleic acid hybridization interactions. A number of different types of biosensors are available in the field, each with real or perceived benefits over the others. This review discusses the basic theory and operational arrangements of four commercially available types of optical biosensors: surface plasmon resonance, resonant mirror, resonance waveguide grating, and dual polarization interferometry. The different applications these techniques offer are discussed from experiments and results reported in recently published literature. Additionally, recent advancements or modifications to the current techniques are also discussed.
Magnetic resonance in Multiple Sclerosis
Energy Technology Data Exchange (ETDEWEB)
Scotti, G.; Scialfa, G.; Biondi, A.; Landoni, L.; Caputo, D.; Cazzullo, C.L.
1986-07-01
Magnetic Resonance Imaging was performed in more than 200 patients with clinical suspicion or knowledge of Multiple Sclerosis. One hundred and forty-seven (60 males and 87 females) had MR evidence of multiple sclerosis lesions. The MR signal of demyelinating plaques characteristically has prolonged T1 and T2 relaxation times and the T2-weighted spin-echo sequences are generally superior to the T1-weighted images because the lesions are better visualized as areas of increased signal intensity. MR is also able to detect plaques in the brainstem, cerebellum and within the cervical spinal cord. MR appears to be an important, non-invasive method for the diagnosis of Multiple Sclerosis and has proven to be diagnostically superior to CT, evoked potentials (EP) and CSF examination. In a selected group of 30 patients, with the whole battery of the relevant MS studies, MR was positive in 100%, CT in 33,3%, EP in 56% and CSF examination in 60%. In patients clinically presenting only with signs of spinal cord involvement or optic neuritis or when the clinical presentation is uncertain MR has proven to be a very useful diagnostic tool for diagnosis of MS by demonstrating unsuspected lesions in the cerebral hemispheres.
String Resonances at Hadron Colliders
Anchordoqui, Luis A; Dai, De-Chang; Feng, Wan-Zhe; Goldberg, Haim; Huang, Xing; Lust, Dieter; Stojkovic, Dejan; Taylor, Tomasz R
2014-01-01
[Abridged] We consider extensions of the standard model based on open strings ending on D-branes. Assuming that the fundamental string mass scale M_s is in the TeV range and that the theory is weakly coupled, we discuss possible signals of string physics at the upcoming HL-LHC run (3000 fb^{-1}) with \\sqrt{s} = 14 TeV, and at potential future pp colliders, HE-LHC and VLHC, operating at \\sqrt{s} = 33 and 100 TeV, respectively. In such D-brane constructions, the dominant contributions to full-fledged string amplitudes for all the common QCD parton subprocesses leading to dijets and \\gamma + jet are completely independent of the details of compactification, and can be evaluated in a parameter-free manner. We make use of these amplitudes evaluated near the first (n=1) and second (n=2) resonant poles to determine the discovery potential for Regge excitations of the quark, the gluon, and the color singlet living on the QCD stack. We show that for string scales as large as 7.1 TeV (6.1 TeV), lowest massive Regge exc...
Aortic dissection: magnetic resonance imaging.
Amparo, E G; Higgins, C B; Hricak, H; Sollitto, R
1985-05-01
Fifteen patients with suspected or known aortic dissection were imaged with magnetic resonance (MR). Thirteen of these patients were eventually shown to have dissection. In most instances the diagnosis was established by aortography and/or computed tomography (CT) prior to the MR study. Surgical proof (6/13) and/or aortographic proof (10/13) were available in 11/13 patients with aortic dissection. MR demonstrated the intimal flap and determined whether the dissection was type A or type B. In addition, MR: differentiated between the true and false lumens; determined the origins of the celiac, superior mesenteric, and renal arteries from the true or false lumen in the cases where the dissection extended into the abdominal aorta (8/12); allowed post-surgical surveillance of the dissection; and identified aortoannular ectasia in the three patients who had Marfan syndrome. In addition to the 13 cases with dissection, there were two cases in whom the diagnosis of dissection was excluded by MR. Our early experience suggests that MR can serve as the initial imaging test in clinically suspected cases of aortic dissection and that the information provided by MR is sufficient to manage many cases. Additionally, MR obviates the use of iodinated contrast media.
Multidimensionally encoded magnetic resonance imaging.
Lin, Fa-Hsuan
2013-07-01
Magnetic resonance imaging (MRI) typically achieves spatial encoding by measuring the projection of a q-dimensional object over q-dimensional spatial bases created by linear spatial encoding magnetic fields (SEMs). Recently, imaging strategies using nonlinear SEMs have demonstrated potential advantages for reconstructing images with higher spatiotemporal resolution and reducing peripheral nerve stimulation. In practice, nonlinear SEMs and linear SEMs can be used jointly to further improve the image reconstruction performance. Here, we propose the multidimensionally encoded (MDE) MRI to map a q-dimensional object onto a p-dimensional encoding space where p > q. MDE MRI is a theoretical framework linking imaging strategies using linear and nonlinear SEMs. Using a system of eight surface SEM coils with an eight-channel radiofrequency coil array, we demonstrate the five-dimensional MDE MRI for a two-dimensional object as a further generalization of PatLoc imaging and O-space imaging. We also present a method of optimizing spatial bases in MDE MRI. Results show that MDE MRI with a higher dimensional encoding space can reconstruct images more efficiently and with a smaller reconstruction error when the k-space sampling distribution and the number of samples are controlled.
Magnetic resonance images of hematospermia
Energy Technology Data Exchange (ETDEWEB)
Hasegawa, Norio; Miki, Kenta; Kato, Nobuki; Furuta, Nozomu; Ohishi, Yukihiko [Jikei Univ., Tokyo (Japan). School of Medicine; Kondo, Naoya; Tashiro, Kazuya
1998-12-01
We performed MRI (magnetic resonance imaging) in the pelvic region of 70 cases with hematospermia and conducted a study on the abnormal MRI findings to which hematospermia could be attributed. We conducted a study on the morphological anomaly and change in the signal intensity in the prostate gland and of the seminal vesicle as well as on the presence or absence of dilation in the plexus venous surrounding the deferent duct or the prostate gland out of the abnormal MRI findings. As for the seminal vesicle, the patients whose seminal vesicle was seen in higher intensity than the prostate gland in T1 weighted images were diagnosed as having hemorrhagic focus and the patients whose seminal vesicle was seen in low intensity both in T1 and T2 weighted images were diagnosed as having fibrosis caused by chronic inflammation. Abnormal MRI findings were seen in 40 out of the 70 cases (57%). Anomaly in the prostate gland was indicated in 6 (9%) cases. Abnormality in the seminal vesicle was indicated in 30 cases (43%) including hemorrhage of seminal vesicle in 25 cases, chronic inflammation in five cases and cyst of seminal vesicle in one case. In conducting an examination of the patients with hematospermia, MRI is the nonivasive and reproducible method and it is possible to identify the hemorrhagic region. Therefore, MRI is thought to be useful to identify the causal organs of hematospermia. (author)
Resonant seismic emission of subsurface objects
Energy Technology Data Exchange (ETDEWEB)
Korneev, Valeri A.
2009-04-15
Numerical modeling results and field data indicate that some contrasting subsurface objects (such as tunnels, caves, pipes, filled pits, and fluid-filled fractures) are capable of generating durable resonant oscillations after trapping seismic energy. These oscillations consist of surface types of circumferential waves that repeatedly propagate around the object. The resonant emission of such trapped energy occurs primarily in the form of shear body waves that can be detected by remotely placed receivers. Resonant emission reveals itself in the form of sharp resonant peaks for the late parts of the records, when all strong direct and primary reflected waves are gone. These peaks were observed in field data for a buried barrel filled with water, in 2D finite-difference modeling results, and in the exact canonical solution for a fluid-filled sphere. A computed animation for the diffraction of a plane wave upon a low-velocity elastic sphere confirms the generation of resonances by durable surface waves. Resonant emission has characteristic quasi-hyperbolic traveltime patterns on shot gathers. The inversion of these patterns can be performed in the frequency domain after muting the strong direct and primary scattered waves. Subsurface objects can be detected and imaged at a single resonance frequency without an accurate knowledge of source trigger time. The imaging of subsurface objects requires information about the shear velocity distribution in an embedding medium, which can be done interactively during inversion.
Acoustic Resonance between Ground and Thermosphere
Directory of Open Access Journals (Sweden)
M Matsumura
2009-04-01
Full Text Available Ultra-low frequency acoustic waves called "acoustic gravity waves" or "infrasounds" are theoretically expected to resonate between the ground and the thermosphere. This resonance is a very important phenomenon causing the coupling of the solid Earth, neutral atmosphere, and ionospheric plasma. This acoustic resonance, however, has not been confirmed by direct observations. In this study, atmospheric perturbations on the ground and ionospheric disturbances were observed and compared with each other to confirm the existence of resonance. Atmospheric perturbations were observed with a barometer, and ionospheric disturbances were observed using the HF Doppler method. An end point of resonance is in the ionosphere, where conductivity is high and the dynamo effect occurs. Thus, geomagnetic observation is also useful, so the geomagnetic data were compared with other data. Power spectral density was calculated and averaged for each month. Peaks appeared at the theoretically expected resonance frequencies in the pressure and HF Doppler data. The frequencies of the peaks varied with the seasons. This is probably because the vertical temperature profile of the atmosphere varies with the seasons, as does the reflection height of infrasounds. These results indicate that acoustic resonance occurs frequently.
Resonant impedance matchers for Mario Schenberg detector
Energy Technology Data Exchange (ETDEWEB)
Frajuca, Carlos; Bortoli, Fabio S. [Centro Federal de Educacao Tecnologica de Sao Paulo, SP (Brazil)
2006-07-01
'Mario Schenberg' is a spherical resonant-mass gravitational wave (GW) detector that will be part of a GW detection array of two detectors, the other one is been built in The Netherlands. Their resonant frequencies will be around 3.2 kHz with a bandwidth of about 200 Hz. This range of frequencies is new in a field where the typical frequencies lay below 1 kHz, making the transducer development much more complex. Some studies indicated that using low mass mechanical resonators (used for impedance matching to the parametric transducer, in a cold damping regime), allow the detector to reach the standard quantum limit. In this work we describe the study of mechanical impedance matcher resonators used to obtain a better coupling between the sphere and the transducers and keeping the same calibration for all transducers, this has been show to be not a easy task since the differential motions of the sphere surface propagates to the motions of the resonant mechanical impedance matchers, when it can be done then the next step is to calculate the effective mass of the resonating mechanical impedance matcher and then, calculate the detector sensitivity, this is also complicated because there is a spread in the resonant mechanical impedance matcher frequencies. (author)
Designing Multipolar Resonances in Dielectric Metamaterials
Butakov, Nikita A.; Schuller, Jon A.
2016-12-01
Dielectric resonators form the building blocks of nano-scale optical antennas and metamaterials. Due to their multipolar resonant response and low intrinsic losses they offer design flexibility and high-efficiency performance. These resonators are typically described in terms of a spherical harmonic decomposition with Mie theory. In experimental realizations however, a departure from spherical symmetry and the use of high-index substrates leads to new features appearing in the multipolar response. To clarify this behavior, we present a systematic experimental and numerical characterization of Silicon disk resonators. We demonstrate that for disk resonators on low-index quartz substrates, the electric and magnetic dipole modes are easily identifiable across a wide range of aspect-ratios, but that higher order peaks cannot be unambiguously associated with any specific multipolar mode. On high-index Silicon substrates, even the fundamental dipole modes do not have a clear association. When arranged into arrays, resonances are shifted and pronounced preferential forward and backward scattering conditions appear, which are not as apparent in individual resonators and may be associated with interference between multipolar modes. These findings present new opportunities for engineering the multipolar scattering response of dielectric optical antennas and metamaterials, and provide a strategy for designing nano-optical components with unique functionalities.
Vibrational resonance in the Morse oscillator
Indian Academy of Sciences (India)
K Abirami; S Rajasekar; M A F Sanjuan
2013-07-01
The occurrence of vibrational resonance is investigated in both classical and quantum mechanical Morse oscillators driven by a biharmonic force. The biharmonic force consists of two forces of widely different frequencies and with $ \\gg $. In the damped and biharmonically driven classical Morse oscillator, by applying a theoretical approach, an analytical expression is obtained for the response amplitude at the low-frequency . Conditions are identified on the parameters for the occurrence of resonance. The system shows only one resonance and moreover at resonance the response amplitude is 1/ where is the coefficient of linear damping. When the amplitude of the high-frequency force is varied after resonance the response amplitude does not decay to zero but approaches a nonzero limiting value. It is observed that vibrational resonance occurs when the sinusoidal force is replaced by a square-wave force. The occurrence of resonance and antiresonance of transition probability of quantum mechanical Morse oscillator is also reported in the presence of the biharmonic external field.
Dynamics and Transit Variations of Resonant Exoplanets
Nesvorný, David; Vokrouhlický, David
2016-06-01
Transit timing variations (TTVs) are deviations of the measured midtransit times from the exact periodicity. One of the most interesting causes of TTVs is the gravitational interaction between planets. Here we consider a case of two planets in a mean motion resonance (orbital periods in a ratio of small integers). This case is important because the resonant interaction can amplify the TTV effect and allow planets to be detected more easily. We develop an analytic model of the resonant dynamics valid for small orbital eccentricities and use it to derive the principal TTV terms. We find that a resonant system should show TTV terms with two basic periods (and their harmonics). The resonant TTV period is proportional (m/M *)-2/3, where m and M * are the planetary and stellar masses. For m = 10-4 M *, for example, the TTV period exceeds the orbital period by about two orders of magnitude. The amplitude of the resonant TTV terms scales linearly with the libration amplitude. The ratio of the TTV amplitudes of two resonant planets is inversely proportional to the ratio of their masses. These and other relationships discussed in the main text can be used to aid the interpretation of TTV observations.
Towards a realistic description of hadron resonances
Schmidt, R. A.; Canton, L.; Schweiger, W.; Plessas, W.
2016-08-01
We report on our attempts of treating excited hadron states as true quantum resonances. Hitherto the spectroscopy of mesons, usually considered as quark-antiquark systems, and of baryons, usually considered as three-quark systems, has been treated through excitation spectra of bound states (namely, confined few-quark systems), corresponding to poles of the quantum-mechanical resolvent at real negative values in the complex energy plane. As a result the wave functions, i.e. the residua of the resolvent, have not exhibited the behaviour as required for hadron resonances with their multiple decay modes. This has led to disturbing shortcomings in the description of hadronic resonance phenomena. We have aimed at a more realistic description of hadron resonances within relativistic constituent-quark models taking into account explicitly meson-decay channels. The corresponding coupled-channels theory is based on a relativistically invariant mass operator capable of producing hadron ground states with real energies and hadron resonances with complex energies, the latter corresponding to poles in the lower half-plane of the unphysical sheet of the complex energy plane. So far we have demonstrated the feasibility of the coupled-channels approach to hadron resonances along model calculations producing indeed the desired properties. The corresponding spectral properties will be discussed in this contribution. More refined studies are under way towards constructing a coupled-channels relativistic constituent-quark model for meson and baryon resonances.
Subwavelength resonant nanostructured films for sensing
Energy Technology Data Exchange (ETDEWEB)
Alvine, Kyle J.; Bernacki, Bruce E.; Suter, Jonathan D.; Bennett, Wendy D.; Edwards, Daniel L.; Mendoza, Albert
2013-05-29
We present a novel subwavelength nanostructure architecture that may be utilized for optical standoff sensing applications. The subwavelength structures are fabricated via a combination of nanoimprint lithography and metal sputtering to create metallic nanostructured films encased within a transparent media. The structures are based on the open ring resonator (ORR) architecture and have their analog in resonant LC circuits, which display a resonance frequency that is inversely proportional to the square root of the product of the inductance and capacitance. Therefore, any perturbation of the nanostructured films due to chemical or environmental effects can alter the inductive or capacitive behavior of the subwavelength features, which can shift the resonant frequency and provide an indication of the external stimulus. This shift in resonance can be interrogated remotely either actively using either laser illumination or passively using hyperspectral or multispectral sensing. These structures may be designed to be either anisotropic or isotropic, which can also provide polarization-sensitive interrogation. Due to the nanometer-scale of the structures, they can be tailored to be optically responsive in the visible or near infrared spectrum with a highly reflective resonant peak that is dependent solely on structural dimensions and material characteristics. We present experimental measurements of the optical response of these structures as a function of wavelength, polarization, and incident angle demonstrating the resonant effect in the near infrared region. Numerical modeling data showing the effect of different fabrication parameters such as structure parameters are also discussed.
On the mechanism of electrochemical modulation of plasmonic resonances
Shao, L.-H.; Ruther, M.; Linden, S.; Wegener, M.; Weissmüller, J.
2012-09-01
Recent electrochemical experiments on gold-based photonic metamaterials have shown a sizable reversible tuning and modulation of plasmonic resonances. Here, we study the mechanism of the electrochemical modulation by measuring the change of the resonance transmittance and resonance frequency during underpotential deposition of Pb, Cu, and electrosorption of OH. The electric resistance change of the resonators is identified as decisive for the resonance transmittance change, while the space-charge layer at the metal surface shifts the resonance frequency.
Electrical Characterization of Microelectromechanical Silicon Carbide Resonators
Directory of Open Access Journals (Sweden)
Christian Zorman
2008-09-01
Full Text Available This manuscript describes the findings of a study to investigate the performance of SiC MEMS resonators with respect to resonant frequency and quality factor under a variety of testing conditions, including various ambient pressures, AC drive voltages, bias potentials and temperatures. The sample set included both single-crystal and polycrystalline 3C-SiC lateral resonators. The experimental results show that operation at reduced pressures increases the resonant frequency as damping due to the gas-rarefaction effect becomes significant. Both DC bias and AC drive voltages result in nonlinearities, but the AC drive voltage is more sensitive to noise. The AC voltage has a voltage coefficient of 1~4ppm/V at a DC bias of 40V. The coefficient of DC bias is about -11ppm/V to - 21ppm/V for poly-SiC, which is more than a factor of two better than a similarly designed polysilicon resonator (-54 ppm/V. The effective stiffness of the resonator decreases (softens as the bias potential is increased, but increases (hardens as drive voltage increase when scan is from low to high frequency. The resonant frequency decreases slightly with increasing temperature, exhibiting a temperature coefficient of -22 ppm/oC, between 22oC and 60oC. The thermal expansion mismatch between the SiC device and the Si substrate could be a reason that thermal coefficient for these SiC resonators is about twofold higher than similar polysilicon resonators. However, the Qs appear to exhibit no temperature dependence in this range.
Indian Academy of Sciences (India)
N D Kataria; Mukul Misra; R Pinto
2002-05-01
Microwave surface resistance s of silver-doped YBa2Cu3O7- (YBCO) thin ﬁlm, deposited by laser ablation technique on 10 mm × 10 mm LaAlO3 substrate, has been measured by resonant techniques in the frequency range from 5 GHz to 20 GHz. The geometrical factor of the sample and the resonator has been determined theoretically by the knowledge of the electromagnetic ﬁeld distribution in the resonators. The microwave surface resistance of the superconducting sample is then extracted from the measured value as a function of temperature. The sensitivity of the s measurement, that is, the relative change in the value with the change in the s value is determined for each resonator.
Photonic molecules formed by coupled hybrid resonators
Peng, Bo; Zhu, Jiangang; Yang, Lan; 10.1364/OL.37.003435
2013-01-01
We describe a method that enables free-standing whispering-gallery-mode microresonators, and report spectral tuning of photonic molecules formed by coupled free and on-chip resonators with different geometries and materials. We study direct coupling via evanescent fields of free silica microtoroids and microspheres with on-chip polymer coated silica microtoroids. We demonstrate thermal tuning of resonance modes to achieve maximal spectral overlap, mode splitting induced by direct coupling, and the effects of distance between the resonators on the splitting spectra.
Kepler-16b: a resonant survivor
Popova, E A
2012-01-01
The planet Kepler-16b is known to follow a circumbinary orbit around a double system of two main-sequence stars. We construct stability diagrams in the "pericentric distance - eccentricity" plane, which show that Kepler-16b is in a hazardous vicinity to the chaos domain - just between the instability "teeth" in the space of orbital parameters. Kepler-16b survives, because it is close to the half-integer 11/2 orbital resonance with the central binary. The neighbouring resonance cells are vacant, because they are "purged" by Kepler-16b, due to overlap of first-order resonances with the planet.
Thermodynamics of the Optical Feshbach Resonance Effect
Blatt, S; Bloom, B J; Williams, J R; Thomsen, J W; Julienne, P S; Ye, J
2011-01-01
Using a narrow intercombination line in alkaline earth atoms to mitigate large inelastic losses, we explore the Optical Feshbach Resonance effect in an ultracold gas of bosonic $^{88}$Sr. A systematic measurement of several resonances allows precise determinations of the OFR strength and scaling law, in agreement with coupled-channels theory. Resonant enhancement of the complex scattering length leads to thermodynamic behavior mediated by elastic and inelastic collisions in an otherwise ideal gas. OFR could be used to control atomic interactions with high spatial and time resolution.
Resonance in a Cone-Topped Tube
Directory of Open Access Journals (Sweden)
Angus Cheng-Huan Chia
2011-06-01
Full Text Available The relationship between ratio of the upper opening diameter of a cone-topped cylinder to the cylinder diameter,and the ratio of the length of the air column to resonant period was examined. Plastic cones with upper openings ranging from 1.3 cm to 3.6 cm and tuning forks with frequencies ranging from 261.6 Hz to 523.3 Hz were used. The transition from a standing wave in a cylindrical column to a Helmholtz-type resonance in a resonant cavity with a narrow opening was observed.
Missing strange resonances in Lattice QCD
Marczenko, Michał
2016-01-01
Recent Lattice QCD (LQCD) studies suggest that there are missing resonances in the strange sector of the Hadron Resonance Gas (HRG) model. By adopting the continuous Hagedorn mass spectrum, we present how different medium compositions influence the HRG predictions of conserved charge fluctuations. It is shown that missing strange resonances may be partially accounted for by applying the Hagedorn mass spectrum extracted from experimentally established hadrons. On the other hand, the strange-baryonic spectra, extracted from LQCD results for fluctuations, are found to be consistent with the unconfirmed states in the Particle Data Group (PDG) database, whilst the strange-mesonic spectrum points towards yet undiscovered states in the intermediate mass region.
Resonance enhancement by suitably chosen frequency detuning
Dutykh, Denys
2014-01-01
In this Letter we report new effects of resonance detuning on various dynamical parameters of a generic 3-wave system. Namely, for suitably chosen values of detuning the variation range of amplitudes can be significantly wider than for exact resonance. Moreover, the range of energy variation is not symmetric with respect to the sign of the detuning. Finally, the period of the energy oscillation exhibits non-monotonic dependency on the magnitude of detuning. These results have important theoretical implications where nonlinear resonance analysis is involved, such as geophysics, plasma physics, fluid dynamics. Numerous practical applications are envisageable e.g. in energy harvesting systems.
Fano Resonances observed in Helium Nanodroplets
LaForge, A C; Jabbari, G; Gokhberg, K; Kryzhevoi, N V; Krishnan, S R; Hess, M; O'Kee?e, P; Ciavardini, A; Prince, K C; Richter, R; Moshammer, R; Cederbaum, L S; Pfeifer, T; Stienkemeier, F; Mudrich, M
2015-01-01
Doubly-excited Rydberg states of helium (He) nanodroplets have been studied using synchrotron radiation. We observed Fano resonances related to the atomic N = 2,0 series as a function of droplet size. Although similar qualitatively to their atomic counterparts, the resonance lines are broader and exhibit a shift in energy which increases for the higher excited states. Furthermore, additional resonances are observed which are not seen in atomic systems. We discuss these features in terms of delocalized atomic states perturbed by the surrounding He atoms and compare to singly excited droplets.
Sound Absorption of Locally Resonant Sonic Materials
Institute of Scientific and Technical Information of China (English)
ZHAO Hong-Gang; LIU Yao-Zong; WEN Ji-Hong; YU Dian-Long; WANG Gang; WEN Xi-Sen
2006-01-01
@@ The acoustic properties of locally resonant sonic materials with viscosity are theoretically investigated by using the multiple-scattering approach. We find that the absorption of a two-layer slab dominates the wave attenuation in the resonant frequency region under the condition of moderate or high viscous level. The fundamental mechanism operating in local resonance for absorption is investigated for the viability by the mode translation in the scattering process of a single scatterer. Finally the absorption performance in a multi-layer system is discussed.
Phonon-Josephson resonances in atomtronic circuits
Bidasyuk, Y. M.; Prikhodko, O. O.; Weyrauch, M.
2016-09-01
We study the resonant excitation of sound modes from Josephson oscillations in Bose-Einstein condensates. From the simulations for various setups using the Gross-Pitaevskii mean-field equations and Josephson equations we observe additional tunneling currents induced by resonant phonons. The proposed experiment may be used for spectroscopy of phonons as well as other low-energy collective excitations in Bose-Einstein condensates. We also argue that the observed effect may mask the observation of Shapiro resonances if not carefully controlled.
Enriched vibrational resonance in certain discrete systems
Indian Academy of Sciences (India)
A Jeevarekha; M Santhiah; P Philominathan
2014-10-01
We wish to report the occurrence of vibrational resonance in certain discrete systems like sine square map and sine circle map, in a unique fashion, comprising of multiple resonant peaks which pave the way for enrichment. As the systems of our choice are capable of exhibiting vibrational resonance behaviour unlike the earlier reports, they are taken for investigation and the necessary numerical and analytical results are presented. Further, we study the effect of external forcing on various attractors of these systems with appropriate bifurcation and Lyapunov exponent diagrams.
Evidence for further charmonium vector resonances
Institute of Scientific and Technical Information of China (English)
Eef van Beveren; George Rupp
2011-01-01
We discuss the shape of threshold signals in production cross sections of the reaction ee → DD, at the opening of the DD and ΛΛ channels. Furthermore, evidence for the ψ(3D), ψ(5S), ψ(4D), ψ(6S), ψ(5D), ψ(7S), ψ(6D), and ψ(8S) new charmonium vector resonances is presented, on the basis of data recently published by the BABAR Collaboration. Central masses and resonance widths are estimated. Confirmation of these resonances would be a huge step in lifting the precision level of hadron spectroscopy towards that of atomic spectroscopy, with far-reaching consequences for theory.
Spin gravitational resonance and graviton detection
Quach, James Q
2016-01-01
We develop a gravitational analogue of spin magnetic resonance, called spin gravitational resonance, whereby a gravitational wave interacts with a magnetic field to produce a spin transition. In particular, an external magnetic field separates the energy spin states of a spin-1/2 particle, and the presence of the gravitational wave produces a perturbation in the components of the magnetic field orthogonal to the gravitational wave propagation. In this framework we test Dyson's conjecture that individual gravitons cannot be detected. Although we find no fundamental laws preventing single gravitons being detected with spin gravitational resonance, we show that it cannot be used in practice, in support of Dyson's conjecture.
Nanoscale constrictions in superconducting coplanar waveguide resonators
Energy Technology Data Exchange (ETDEWEB)
Jenkins, Mark David; Naether, Uta; Ciria, Miguel; Zueco, David; Luis, Fernando, E-mail: fluis@unizar.es [Instituto de Ciencia de Materiales de Aragón, CSIC—Universidad de Zaragoza, 50009 Zaragoza (Spain); Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza (Spain); Sesé, Javier [Instituto de Nanociencia de Aragón, Universidad de Zaragoza, E-50009 Zaragoza (Spain); Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza (Spain); Atkinson, James; Barco, Enrique del [Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States); Sánchez-Azqueta, Carlos [Dpto. de Ingeniería Electrónica y Telecomunicaciones, Universidad de Zaragoza, 50009 Zaragoza (Spain); Majer, Johannes [Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna (Austria)
2014-10-20
We report on the design, fabrication, and characterization of superconducting coplanar waveguide resonators with nanoscopic constrictions. By reducing the size of the center line down to 50 nm, the radio frequency currents are concentrated and the magnetic field in its vicinity is increased. The device characteristics are only slightly modified by the constrictions, with changes in resonance frequency lower than 1% and internal quality factors of the same order of magnitude as the original ones. These devices could enable the achievement of higher couplings to small magnetic samples or even to single molecular spins and have applications in circuit quantum electrodynamics, quantum computing, and electron paramagnetic resonance.
Interfering resonances in a quantum billiard
Persson, E; Rotter, I; Seba, P
1998-01-01
We present a method for numerically obtaining the positions, widths and wavefunctions of resonance states in a two dimensional billiard connected to a waveguide. For a rectangular billiard, we study the dynamics of three resonance poles lying separated from the other ones. As a function of increasing coupling strength between the waveguide and the billiard two of the states become trapped while the width of the third one continues to increase for all coupling strengths. This behavior of the resonance poles is reflected in the time delay function which can be studied experimentally.
Resonant MEMS fundamentals, implementation, and application
Brand, Oliver; Heinrich, Stephen; Josse, Fabien; Fedder, Gary K; Hierold, Christofer; Korvink, Jan G; Tabata, Osamu
2015-01-01
Part of the AMN book series, this book covers the principles, modeling and implementation as well as applications of resonant MEMS from a unified viewpoint. It starts out with the fundamental equations and phenomena that govern the behavior of resonant MEMS and then gives a detailed overview of their implementation in capacitive, piezoelectric, thermal and organic devices, complemented by chapters addressing the packaging of the devices and their stability. The last part of the book is devoted to the cutting-edge applications of resonant MEMS such as inertial, chemical and biosensors, fluid p
Imprisonment dynamics of resonance radiation in gases
Energy Technology Data Exchange (ETDEWEB)
Kosarev, N I; Shaparev, N Y, E-mail: kosarev_nikolai@mail.ru [Institute of Computational Modeling, Siberian Branch of the Russian Academy of Sciences, Krasnoyarsk, 660036 (Russian Federation)
2011-05-28
Imprisonment of resonant radiation in gases on the basis of the numerical solution of the rate balance equation for the excited atoms and the transfer resonant radiation equation is investigated. Calculations of the escape factor for the slab, cylinder and sphere at Doppler and Lorentz forms of absorption and scattering profiles are executed. Calculation results of the escape factor for the cylinder and slab are compared with Holsten's asymptotical solutions. The numerical data for time dependence of a spectrum, the intensity of resonant radiation and the spatial distribution of the excited atomic concentration in a regime of afterglow are also considered.
Optomechanical magnetometry with a macroscopic resonator
Yu, Changqiu; Sheridan, Eoin; McAuslan, David L; Rubinsztein-Dunlop, Halina; Lam, Ping Koy; Zhang, Yundong; Bowen, Warwick P
2015-01-01
We demonstrate a centimeter-scale optomechanical magnetometer based on a crystalline whispering gallery mode resonator. The large size of the resonator allows high magnetic field sensitivity to be achieved in the hertz to kilohertz frequency range. A peak sensitivity of 131 pT per root Hz is reported, in a magnetically unshielded non-cryogenic environment and using optical power levels beneath 100 microWatt. Femtotesla range sensitivity may be possible in future devices with further optimization of laser noise and the physical structure of the resonator, allowing applications in high-performance magnetometry.
Theoretical foundations of electron spin resonance
Harriman, John E
2013-01-01
Theoretical Foundations of Electron Spin Resonance deals with the theoretical approach to electron paramagnetic resonance. The book discusses electron spin resonance in applications related to polyatomic, probably organic, free radicals in condensed phases. The book also focuses on essentially static phenomena, that is, the description and determination of stationary-state energy levels. The author reviews the Dirac theory of the electron in which a four-component wave function is responsible for the behavior of the electron. The author then connects this theory with the nonrelativistic wave f
Mie resonance-based dielectric metamaterials
Directory of Open Access Journals (Sweden)
Qian Zhao
2009-12-01
Full Text Available Increasing attention on metamaterials has been paid due to their exciting physical behaviors and potential applications. While most of such artificial material structures developed so far are based on metallic resonant structures, Mie resonances of dielectric particles open a simpler and more versatile route for construction of isotropic metamaterials with higher operating frequencies. Here, we review the recent progresses of Mie resonance-based metamaterials by providing a description of the underlying mechanisms to realize negative permeability, negative permittivity and double negative media. We address some potential novel applications.
Quantum Stochastic Resonance in Electron Shelving
Huelga, S F
2000-01-01
Stochastic resonance shows that under some circumstances noise can enhance the response of a system to a periodic force. While this effect has been extensively investigated theoretically and demonstrated experimentally in classical systems, there is complete lack of experimental evidence within the purely quantum mechanical domain. Here we demonstrate that stochastic resonance can be exhibited in a single ion and would be experimentally observable using well mastered experimental techniques. We discuss the use of this scheme for the detection of the frequency difference of two lasers to demonstrate that stochastic resonance may have applications in precision measurements at the quantum limit.
Alpha resonant scattering for astrophysical reaction studies
Energy Technology Data Exchange (ETDEWEB)
Yamaguchi, H.; Kahl, D.; Nakao, T. [Center for Nuclear Study (CNS), University of Tokyo, RIKEN campus, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Wakabayashi, Y.; Kubano, S. [The Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Hashimoto, T. [Research Center for Nuclear Physics (RCNP), Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Hayakawa, S. [Istituto Nazionale Fisica Nucleare - Laboratori Nazionali del Sud (INFN-LNS), Via S. Sofia 62, 95125 Catania (Italy); Kawabata, T. [Department of Physics, Kyoto University, Kita-Shirakawa, Kyoto 606-8502 (Japan); Iwasa, N. [Department of Physics, Tohoku University, Aoba, Sendai, Miyagi 980-8578 (Japan); Teranishi, T. [Department of Physics, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-8581 (Japan); Kwon, Y. K. [Institute for Basic Science, 70, Yuseong-daero 1689-gil, Yuseong-gu, Daejeon 305-811 (Korea, Republic of); Binh, D. N. [30 MeV Cyclotron Center, Tran Hung Dao Hospital, Hoan Kiem District, Hanoi (Viet Nam); Khiem, L. H.; Duy, N. G. [Institute of Physics, Vietnam Academy of Science and Technology, 18 Hong Quoc Viet, Nghia do, Hanoi (Viet Nam)
2014-05-02
Several alpha-induced astrophysical reactions have been studied at CRIB (CNS Radioactive Ion Beam separator), which is a low-energy RI beam separator at Center for Nuclear Study (CNS) of the University of Tokyo. One of the methods to study them is the α resonant scattering using the thick-target method in inverse kinematics. Among the recent studies at CRIB, the measurement of {sup 7}Be+α resonant scattering is discussed. Based on the result of the experiment, we evaluated the contributions of high-lying resonances for the {sup 7}Be(α,γ) reaction, and proposed a new cluster band in {sup 11}C.
Resonance spectra of diabolo optical antenna arrays
Guo, Hong; Simpkins, Blake; Caldwell, Joshua D.; Guo, Junpeng
2015-10-01
A complete set of diabolo optical antenna arrays with different waist widths and periods was fabricated on a sapphire substrate by using a standard e-beam lithography and lift-off process. Fabricated diabolo optical antenna arrays were characterized by measuring the transmittance and reflectance with a microscope-coupled FTIR spectrometer. It was found experimentally that reducing the waist width significantly shifts the resonance to longer wavelength and narrowing the waist of the antennas is more effective than increasing the period of the array for tuning the resonance wavelength. Also it is found that the magnetic field enhancement near the antenna waist is correlated to the shift of the resonance wavelength.
Resonance spectra of diabolo optical antenna arrays
Energy Technology Data Exchange (ETDEWEB)
Guo, Hong; Guo, Junpeng, E-mail: guoj@uah.edu [Department of Electrical and Computer Engineering, University of Alabama in Huntsville, 301 Sparkman Drive, Huntsville, AL 35899 (United States); Simpkins, Blake; Caldwell, Joshua D. [Naval Research Laboratory, 4555 Overlook Ave., SW Washington, DC 20375 (United States)
2015-10-15
A complete set of diabolo optical antenna arrays with different waist widths and periods was fabricated on a sapphire substrate by using a standard e-beam lithography and lift-off process. Fabricated diabolo optical antenna arrays were characterized by measuring the transmittance and reflectance with a microscope-coupled FTIR spectrometer. It was found experimentally that reducing the waist width significantly shifts the resonance to longer wavelength and narrowing the waist of the antennas is more effective than increasing the period of the array for tuning the resonance wavelength. Also it is found that the magnetic field enhancement near the antenna waist is correlated to the shift of the resonance wavelength.
Resonant-state expansion Born Approximation
Doost, M B
2015-01-01
The Born Approximation is a fundamental formula in Physics, it allows the calculation of weak scattering via the Fourier transform of the scattering potential. I extend the Born Approximation by including in the formula the Fourier transform of a truncated basis of the infinite number of appropriately normalised resonant states. This extension of the Born Approximation is named the Resonant-State Expansion Born Approximation or RSE Born Approximation. The resonant-states of the system can be calculated using the recently discovered RSE perturbation theory for electrodynamics and normalised correctly to appear in spectral Green's functions via the flux volume normalisation.
Resonances in open quantum systems
Eleuch, Hichem; Rotter, Ingrid
2017-02-01
The Hamilton operator of an open quantum system is non-Hermitian. Its eigenvalues are generally complex and provide not only the energies but also the lifetimes of the states of the system. The states may couple via the common environment of scattering wave functions into which the system is embedded. This causes an external mixing (EM) of the states. Mathematically, EM is related to the existence of singular (the so-called exceptional) points. The eigenfunctions of a non-Hermitian operator are biorthogonal, in contrast to the orthogonal eigenfunctions of a Hermitian operator. A quantitative measure for the ratio between biorthogonality and orthogonality is the phase rigidity of the wave functions. At and near an exceptional point (EP), the phase rigidity takes its minimum value. The lifetimes of two nearby eigenstates of a quantum system bifurcate under the influence of an EP. At the parameter value of maximum width bifurcation, the phase rigidity approaches the value one, meaning that the two eigenfunctions become orthogonal. However, the eigenfunctions are externally mixed at this parameter value. The S matrix and therewith the cross section do contain, in the one-channel case, almost no information on the EM of the states. The situation is completely different in the case with two (or more) channels where the resonance structure is strongly influenced by the EM of the states and interesting features of non-Hermitian quantum physics are revealed. We provide numerical results for two and three nearby eigenstates of a non-Hermitian Hamilton operator that are embedded in one common continuum and are influenced by two adjoining EPs. The results are discussed. They are of interest for an experimental test of the non-Hermitian quantum physics as well as for applications.
Enhanced energy storage in chaotic optical resonators
Liu, Changxu
2013-05-05
Chaos is a phenomenon that occurs in many aspects of contemporary science. In classical dynamics, chaos is defined as a hypersensitivity to initial conditions. The presence of chaos is often unwanted, as it introduces unpredictability, which makes it difficult to predict or explain experimental results. Conversely, we demonstrate here how chaos can be used to enhance the ability of an optical resonator to store energy. We combine analytic theory with ab initio simulations and experiments in photonic-crystal resonators to show that a chaotic resonator can store six times more energy than its classical counterpart of the same volume. We explain the observed increase by considering the equipartition of energy among all degrees of freedom of the chaotic resonator (that is, the cavity modes) and discover a convergence of their lifetimes towards a single value. A compelling illustration of the theory is provided by enhanced absorption in deformed polystyrene microspheres. © 2013 Macmillan Publishers Limited. All rights reserved.
Recent hadronic resonance measurements at ALICE
Knospe, A.G.
2016-01-01
In heavy-ion physics, measurements of short-lived hadronic resonances allow the properties of the hadronic phase of the collision to be studied. In addition, resonances can be used along with stable hadrons to study parton energy loss in the quark-gluon plasma and the mechanisms that shape hadron pT spectra at intermediate transverse momenta. Resonance measurements in small systems serve as a reference for heavy-ion collisions and contribute to searches for collective effects. An overview of recent results on hadronic resonance production measured in ALICE is presented. These results include the pT spectra and yields of the rho(770)0, K*(892)0, and phi(1020) mesons in pp, p-Pb, and Pb-Pb collisions at different energies as well as the Sigma(1385)+/- and Xi(1530)0 baryons in pp and p-Pb collisions.
Thermally tunable quadruple Vernier racetrack resonators.
Boeck, Robert; Chrostowski, Lukas; Jaeger, Nicolas A F
2013-07-15
The spectral responses of series-coupled racetrack resonators exhibiting the Vernier effect have many attractive features as compared to the spectral responses of identical series-coupled racetrack resonators, such as free spectral range (FSR) extension and enhanced wavelength tunability. Here we present experimental results of a thermally tunable quadruple series-coupled silicon racetrack resonator exhibiting the Vernier effect. We thermally tune two of the four racetrack resonators to enable discrete switching of the major peak by 15.54 nm. Also, our device has an interstitial peak suppression of 35.4 dB, a 3 dB bandwidth of 0.45 nm, and an extended FSR of 37.66 nm.
Quark-mass dependence of baryon resonances
Energy Technology Data Exchange (ETDEWEB)
Lutz, M.F.M. [Gesellschaft fuer Schwerionenforschung (GSI), Planck Str. 1, D-64291 Darmstadt (Germany) and Institut fuer Kernphysik, TU Darmstadt, D-64289 Darmstadt (Germany)]. E-mail: m.lutz@gsi.de; Garcia-Recio, C. [Departamento de Fisica Moderna, Universidad de Granada, E-18071 Granada (Spain); Kolomeitsev, E.E. [Niels Bohr Institute, Blegdamsvej 17, DK-2100 Copenhagen (Denmark); Nieves, J. [Departamento de Fisica Moderna, Universidad de Granada, E-18071 Granada (Spain)
2005-05-30
We study the quark-mass dependence of JP=12- s-wave and JP=32- d-wave baryon resonances. Parameter-free results are obtained in terms of the leading order chiral Lagrangian. In the 'heavy' SU(3) limit with m{pi}=mK{approx}500 MeV the s-wave resonances turn into bound states forming two octets plus a singlet representations of the SU(3) group. Similarly the d-wave resonances turn into bound states forming an octet and a decuplet in this limit. A contrasted result is obtained in the 'light' SU(3) limit with m{pi}=mK{approx}140 MeV for which no resonances exist.
Boosting low-mass hadronic resonances
Shimmin, Chase
2016-01-01
Searches for new hadronic resonances typically focus on high-mass spectra, due to overwhelming QCD backgrounds and detector trigger rates. We present a study of searches for relatively low-mass hadronic resonances at the LHC in the case that the resonance is boosted by recoiling against a well-measured high-$p_{\\textrm{T}}$ probe such as a muon, photon or jet. The hadronic decay of the resonance is then reconstructed either as a single large-radius jet or as a resolved pair of standard narrow-radius jets, balanced in transverse momentum to the probe. We show that the existing 2015 LHC dataset of $pp$ collisions with $\\int\\mathcal{L}dt = 4\\ \\mathrm{fb}^{-1}$ should already have powerful sensitivity to a generic $Z'$ model which couples only to quarks, for $Z'$ masses ranging from 20-500 GeV/c$^2$.
Characterization system for resonant micro- and nanocantilevers
DEFF Research Database (Denmark)
Sandberg, Rasmus Kousholt; Boisen, Anja; Svendsen, Winnie Edith
2005-01-01
We present a system for characterization of the resonant properties of micro- and nanocantilever sensors. The system has been constructed as a vacuum chamber with capabilities for controlling environmental conditions such as pressure, temperature, and chemical constituents. Characterization can...
Electronic dipole resonance in smoky quartz
Kerssen, J.; Volger, J.
1967-01-01
Microwave absorption in smoky quartz mono-crystal is ascribed to resonance transitions of trapped electrons between initially configurational degenerated states, which are Stark-splitted by a polarizing electric field.
Visuomotor resonance in autism spectrum disorders
Directory of Open Access Journals (Sweden)
Cristina eBecchio
2012-11-01
Full Text Available When we observe the actions performed by others, our motor system ‘resonates' along with that of the observed agent. Is a similar visuomotor resonant response observed in autism spectrum disorders (ASD? Studies investigating action observation in ASD have yielded inconsistent findings. In this perspective article we examine behavioral and neuroscientific evidence in favor of visuomotor resonance in ASD, and consider the possible role of action-perception coupling in social cognition. We distinguish between different aspects of visuomotor resonance and conclude that while some aspects may be preserved in ASD, abnormalities exist in the way individuals with ASD convert visual information from observed actions into a program for motor execution. Such abnormalities, we surmise, may contribute to but also depend on the difficulties that individuals with ASD encounter during social interaction.
Nanofabricated Optomechanical Whispering Gallery Mode Resonators Project
National Aeronautics and Space Administration — Strong interest in whispering gallery mode resonators (WGMR) for use in chip-scale photonic devices is motivated by their high optical quality, mechanical simplicity...
Quantum Effect in Mesoscopic Open Electron Resonator
Institute of Scientific and Technical Information of China (English)
YAN Zhan-Yuan; ZHANG Xiao-Hong; HAN Ying-Hui
2008-01-01
The open electron resonator is a mesoscopic device that has attracted considerable attention due to its remarkable behavior: conductance oscillations. In this paper, using an improved quantum theory to mesoscopic circuits developed recently by Li and Chen, the mesoscopic electron resonator is quantized based on the fundamental fact that the electric charge takes discrete value. With presentation transformation and unitary transformation, the Schrodinger equation becomes an standard Mathieu equation. Then, the detailed energy spectrum and wave functions in the system are obtained, which will be helpful to the observation of other characters of electron resonator. The average of currents and square of the current are calculated, the results show the existence of the current fluctuation, which causes the noise in the circuits, the influence of inductance to the noise is discussed. With the results achieved, the stability characters of mesoscopic electron resonator are studied firstly, these works would be benefit to the design and control of integrate circuit.
A transmission calibration method for superconducting resonators
Cataldo, Giuseppe; Barrentine, Emily M; Brown, Ari D; Moseley, Samuel H; U-Yen, Kongpop
2014-01-01
A method is proposed and experimentally explored for \\textit{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 was modeled 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 microst...
Resonances and fluctuations in the statistical model
Directory of Open Access Journals (Sweden)
Torrieri Giorgio
2012-11-01
Full Text Available We describe how the study of resonances and fluctuations can help constrain the thermal and chemical freezeout properties of the fireball created in heavy ion collisions. This review is based on [1–5
Characterization of superconducting transmission line resonators
Energy Technology Data Exchange (ETDEWEB)
Goetz, Jan; Summer, Philipp; Meier, Sebastian; Haeberlein, Max; Wulschner, Karl Friedrich; Eder, Peter; Fischer, Michael; Schwarz, Manuel; Deppe, Frank; Fedorov, Kirill; Huebl, Hans; Menzel, Edwin [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany); Krawczyk, Marta; Marx, Achim [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Baust, Alexander; Xie, Edwar; Zhong, Ling; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany); Nanosystems Initiative Munich (NIM), Muenchen (Germany)
2015-07-01
Superconducting transmission line resonators are widely used in circuit quantum electrodynamics experiments as quantum bus or storage devices. For these applications, long coherence times, which can be linked to the internal quality factor of the resonators, are crucial. Here, we show a systematic study of the internal quality factor of niobium thin film resonators. We analyze different cleaning methods and substrate parameters for coplanar waveguide as well as microstrip geometries. In addition, we investigate the impact of a niobium-aluminum interface which is necessary for galvanically coupled flux qubits made from aluminum. This interface can be avoided by fabricating the complete resonator-qubit structure using Al/AlO{sub x}/Al technology during fabrication.
Wideband MEMS Resonator Using Multifrequency Excitation
Jaber, Nizar
2016-03-09
We demonstrate the excitation of combination resonances of additive and subtractive types and their exploitations to realize a large bandwidth micro-machined resonator of large amplitude even at higher harmonic modes of vibrations. The investigation is conducted on a Microelectromechanical systems (MEMS) clamped-clamped microbeam fabricated using polyimide as a structural layer coated with nickel from top and chromium and gold layers from bottom. The microbeam is excited by a two-source harmonic excitation, where the first frequency source is swept around the targeted resonance (first or third mode of vibration) while the second source frequency is kept fixed. We report for the first time a large bandwidth and large amplitude response near the higher order modes of vibration. Also, we show that by properly tuning the frequency and amplitude of the excitation force, the frequency bandwidth of the resonator is controlled.
Topological Insulator Realized with Piezoelectric Resonators
McHugh, S.
2016-07-01
We propose a realization of a two-dimensional topological insulator using an array of microwave piezoelectric resonators. The resonators are coupled electrically, but acoustically isolated. The inter-resonator electromagnetic coupling required to reproduce an effective mechanical topological insulator is found explicitly. Both the acoustic and electric response show the essential features of topological insulator, e.g., helical edge states. The helical edge states may be useful for engineering nonreciprocal electronic devices like isolators and circulators. These components do not often appear in the radios of modern mobile phones since they traditionally require bulky magnetic material. However, a nonreciprocal device based on piezoelectric resonators may meet the demands of phone manufacturers due to their small size, high-linearity, and ease of fabrication.
Boosting low-mass hadronic resonances
Shimmin, Chase; Whiteson, Daniel
2016-09-01
Searches for new hadronic resonances typically focus on high-mass spectra due to overwhelming QCD backgrounds and detector trigger rates. We present a study of searches for relatively low-mass hadronic resonances at the LHC in the case that the resonance is boosted by recoiling against a well-measured high-pT probe such as a muon, photon or jet. The hadronic decay of the resonance is then reconstructed either as a single large-radius jet or as a resolved pair of standard narrow-radius jets, balanced in transverse momentum to the probe. We show that the existing 2015 LHC data set of p p collisions with ∫L d t =4 fb-1 should already have powerful sensitivity to a generic Z' model which couples only to quarks, for Z' masses ranging from 20 - 500 GeV /c2 .
Critical coupling in plasmonic resonator arrays
Balci, Sinan; Kocabas, Coskun; Aydinli, Atilla
2011-08-01
We report critical coupling of electromagnetic waves to plasmonic cavity arrays fabricated on Moiré surfaces. Dark field plasmon microscopy imaging and polarization dependent spectroscopic reflection measurements reveal the critical coupling conditions of the cavities. The critical coupling conditions depend on the superperiod of the Moiré surface, which also defines the coupling between the cavities. Complete transfer of the incident power can be achieved for traveling wave plasmonic resonators, which have a relatively short superperiod. When the superperiod of the resonators increases, the coupled resonators become isolated standing wave resonators in which complete transfer of the incident power is not possible. Analytical and finite difference time domain calculations support the experimental observations.
Acoustic Resonance Reaction Control Thruster (ARCTIC) Project
National Aeronautics and Space Administration — ORBITEC proposes to develop and demonstrate the innovative Acoustic Resonance Reaction Control Thruster (ARCTIC) to provide rapid and reliable in-space impulse...
Fabrication of MEMS Resonators in Thin SOI
Grogg, D; Ionescu, Adrian Mihai
2008-01-01
A simple and fast process for micro-electromechanical (MEM) resonators with deep sub-micron transduction gaps in thin SOI is presented in this paper. Thin SOI wafers are important for advanced CMOS technology and thus are evaluated as resonator substrates for future co-integration with CMOS circuitry on a single chip. As the transduction capacitance scales with the resonator thickness, it is important to fabricate deep sub-micron trenches in order to achieve a good capacitive coupling. Through the combination of conventional UV-lithography and focused ion beam (FIB) milling the process needs only two lithography steps, enabling therefore a way for fast prototyping of MEM-resonators. Different FIB parameters and etching parameters are compared in this paper and their effect on the process are reported.
Resonant Electromagnetic Shunt Damping of Flexible Structures
DEFF Research Database (Denmark)
Høgsberg, Jan Becker
2016-01-01
Electromagnetic transducers convert mechanical energy to electrical energy and vice versa. Effective passive vibration damping of flexible structures can therefore be introduced by shunting with an accurately calibrated resonant electrical network thatcontains a capacitor to create the desired...
Superconducting Resonant Inductive Power Coupling Project
National Aeronautics and Space Administration — The proposed effort will develop a technology to wirelessly and efficiently transfer power over hundreds of meters via resonant inductive coupling. The key...
High Energy Single Frequency Resonant Amplifier Project
National Aeronautics and Space Administration — This SBIR phase I project proposes a single frequency high energy resonant amplifier for remote sensing. Current state-of-art technologies can not provide all...
Your Radiologist Explains Magnetic Resonance Angiography (MRA)
Full Text Available ... with you about magnetic resonance angiography, or as it’s commonly known, MRA. MRA is a noninvasive test ... of the major blood vessels throughout your body. It may be performed with or without contrast material ...
Resonant metallic nanostructures for enhanced terahertz spectroscopy
Toma, A.
2015-11-12
We present our recent studies on terahertz resonant dipole nanoantennas. Exploiting the localization and enhancement capabilities of these devices, we introduce an effective method to perform terahertz spectroscopy on an extremely small number of nano-objects.
Sigma photoproduction in the resonance region
Janssen, S; Debruyne, D; Van Cauteren, T
2002-01-01
A study of p(gamma,K)Sigma processes in an isobar model at tree level is reported. By comparing model calculations to the published SAPHIR data, we explore the possible role of different isospin I=1/2 (N*) and I=3/2 (Delta*) resonances in the reaction dynamics. In our analysis, the inclusion of the ``missing'' D_{13}(1895) resonance does only slightly improve the global description of the Sigma photoproduction data. More convincing signals for the presence of such a ``missing'' resonance emerged in the analysis of the isospin related p(gamma,K+)Lambda reaction. Various implementations of the nonresonant part of the Sigma photoproduction amplitude are presented. The sensitivity of the computed observables and extracted resonance parameters to the uncertainties inherent to the treatment of the nonresonant (background) diagrams are discussed.
Dynamic nonlinear thermal optical effects in coupled ring resonators
Directory of Open Access Journals (Sweden)
Chenguang Huang
2012-09-01
Full Text Available We investigate the dynamic nonlinear thermal optical effects in a photonic system of two coupled ring resonators. A bus waveguide is used to couple light in and out of one of the coupled resonators. Based on the coupling from the bus to the resonator, the coupling between the resonators and the intrinsic loss of each individual resonator, the system transmission spectrum can be classified by three different categories: coupled-resonator-induced absorption, coupled-resonator-induced transparency and over coupled resonance splitting. Dynamic thermal optical effects due to linear absorption have been analyzed for each category as a function of the input power. The heat power in each resonator determines the thermal dynamics in this coupled resonator system. Multiple “shark fins” and power competition between resonators can be foreseen. Also, the nonlinear absorption induced thermal effects have been discussed.
Experimental study of resonance fiber optic gyroscope employing a dual-ring resonator
Fan, Yue; Wang, Wei
2016-09-01
A dual-ring resonator which is available to alter the full width at half maximum (FWHM) without altering the free spectrum range (FSR) for practice applications is analyzed theoretically and set up in practice. The parameters of the dual-ring resonator have been optimized in simulation, the resonance depth and the dynamic range are enhanced. The prototype is set up with single mode fiber of 8 meter and two 95 : 5 couplers for open loop experiment. The FWHM of the dual-ring resonator is demonstrated less than 1.5MHz and the fineness is calculated to be 37 during the frequency sweeping experiment. The frequency locking experiment with demodulation curve method has been accomplished, and the locking time achieves less than 40ms. All these provide a basic reference for optimizing the resonance fiber optic gyro based on dual-ring resonator.
Electrostatically actuated torsional resonant sensors and switches
Younis, Mohammad I.
2016-12-29
Embodiments in accordance of a torsional resonant sensor disclosure is configured to actuate a beam structure using electrostatic actuation with an AC harmonic load (e.g., AC and DC voltage sources) that is activated upon detecting a particular agent having a mass above a predefined level. In various embodiments, the beam structure may be different types of resonant structures that is at least partially coated or layered with a selective material.
Can magnetic resonance imaging differentiate undifferentiated arthritis?
DEFF Research Database (Denmark)
Østergaard, Mikkel; Duer, Anne; Hørslev-Petersen, K
2005-01-01
A high sensitivity for the detection of inflammatory and destructive changes in inflammatory joint diseases makes magnetic resonance imaging potentially useful for assigning specific diagnoses, such as rheumatoid arthritis and psoriatic arthritis in arthritides, that remain undifferentiated after...... conventional clinical, biochemical and radiographic examinations. With recent data as the starting point, the present paper describes the current knowledge on magnetic resonance imaging in the differential diagnosis of undifferentiated arthritis....
Energy Technology Data Exchange (ETDEWEB)
Wilson, David J. [Old Dominion University, Norfolk, VA
2014-06-23
We have obtained clear signals of resonances in coupled-channel pi K - eta K scattering. Using distillation and a large basis of operators we are able to extract a precise spectrum of energy levels using the variational method. These energies are analysed using inelastic extensions of the Luescher method to obtain scattering amplitudes that clearly describe S, P and D wave resonances, corresponding to the physical K_0^*(1430), the K^*(892) and the K_2^*(1430).
Parametric resonance in concrete beam-columns
Sharma,Mamta R.; Singh,Arbind K; Benipal,Gurmail S
2014-01-01
A dynamic instability, called parametric resonance, is exhibited by undampedelastic beam-columns when under the action of pulsating axial force. The scope of the existing theory of parametric resonance is restricted to physically linear beam-columns undergoing finite lateral displacements. In this Paper, the dynamic behaviour of physically nonlinear elastic cracked concrete beam-columns under pulsating axial force and constant lateral force is investigated. The constitutive equations derived ...
Analysis of SAW distributed feedback resonators
Vandewege, J.; Lagasse, P. E.
1981-01-01
The main characteristics and advantages of the surface acoustic wave (SAW) distributed feedback resonator are discussed. A coupled mode analysis provides physical insight and simple formulas for the resonant frequency, the quality factor, and the input impedance. Those results are verified by means of a transmission line computer model and by a number of measurements in the frequency range 30-250 MHz. On YZ LiNbO3 substrates, quality factors of the order of 5,000 are routinely obtained.
Deformation effects in Giant Monopole Resonance
Kvasil, J; Repko, A; Bozik, D; Kleinig, W; Reinhard, P -G
2014-01-01
The isoscalar giant monopole resonance (GMR) in Samarium isotopes (from spherical $^{144}$Sm to deformed $^{148-154}$Sm) is investigated within the Skyrme random-phase-approximation (RPA) for a variety of Skyrme forces. The exact RPA and its separable version (SRPA) are used for spherical and deformed nuclei, respectively. The quadrupole deformation is shown to yield two effects: the GMR broadens and attains a two-peak structure due to the coupling with the quadrupole giant resonance.
Resonant quantum transitions in trapped antihydrogen atoms.
Amole, C; Ashkezari, M D; Baquero-Ruiz, M; Bertsche, W; Bowe, P D; Butler, E; Capra, A; Cesar, C L; Charlton, M; Deller, A; Donnan, P H; Eriksson, S; Fajans, J; Friesen, T; Fujiwara, M C; Gill, D R; Gutierrez, A; Hangst, J S; Hardy, W N; Hayden, M E; Humphries, A J; Isaac, C A; Jonsell, S; Kurchaninov, L; Little, A; Madsen, N; McKenna, J T K; Menary, S; Napoli, S C; Nolan, P; Olchanski, K; Olin, A; Pusa, P; Rasmussen, C Ø; Robicheaux, F; Sarid, E; Shields, C R; Silveira, D M; Stracka, S; So, C; Thompson, R I; van der Werf, D P; Wurtele, J S
2012-03-07
The hydrogen atom is one of the most important and influential model systems in modern physics. Attempts to understand its spectrum are inextricably linked to the early history and development of quantum mechanics. The hydrogen atom's stature lies in its simplicity and in the accuracy with which its spectrum can be measured and compared to theory. Today its spectrum remains a valuable tool for determining the values of fundamental constants and for challenging the limits of modern physics, including the validity of quantum electrodynamics and--by comparison with measurements on its antimatter counterpart, antihydrogen--the validity of CPT (charge conjugation, parity and time reversal) symmetry. Here we report spectroscopy of a pure antimatter atom, demonstrating resonant quantum transitions in antihydrogen. We have manipulated the internal spin state of antihydrogen atoms so as to induce magnetic resonance transitions between hyperfine levels of the positronic ground state. We used resonant microwave radiation to flip the spin of the positron in antihydrogen atoms that were magnetically trapped in the ALPHA apparatus. The spin flip causes trapped anti-atoms to be ejected from the trap. We look for evidence of resonant interaction by comparing the survival rate of trapped atoms irradiated with microwaves on-resonance to that of atoms subjected to microwaves that are off-resonance. In one variant of the experiment, we detect 23 atoms that survive in 110 trapping attempts with microwaves off-resonance (0.21 per attempt), and only two atoms that survive in 103 attempts with microwaves on-resonance (0.02 per attempt). We also describe the direct detection of the annihilation of antihydrogen atoms ejected by the microwaves.
Magnetic resonance imaging of valvular heart disease
DEFF Research Database (Denmark)
Søndergaard, Lise; Ståhlberg, F; Thomsen, C
1999-01-01
The optimum management of patients with valvular heart diseases requires accurate and reproducible assessment of the valvular lesion and its hemodynamic consequences. Magnetic resonance imaging (MRI) techniques, such as volume measurements, signal-void phenomena, and velocity mapping, can be used...... the optimal timing for valvular surgery. This paper reviews the validation of these MRI techniques in assessing valvular heart disease and discusses some typical pitfalls of the techniques, including suggestions for solutions.J. Magn. Reson. Imaging 1999;10:627-638....
Multiport Resonant DC-DC Converter
Tran, Yan-Kim; Dujic, Drazen; Barrade, Philippe
2015-01-01
his paper presents a multiport galvanically isolated LLC resonant DC-DC converter suitable for DC applications. A three-port structure is analyzed, with full bidirectional power flow capabilities, simple control and behavior similar to that expected from a DC transformer. Each port is equipped with half-bridge modules accompanied with tuned resonant tank, partly realized with elements of a multi- winding high frequency transformer. With some restrictions that are explained in the paper, each ...
de Sitter Harmonies: Cosmological Spacetimes as Resonances
Maltz, Jonathan
2016-01-01
The aim of this work is to provided the details of a calculation summarized in the recent paper by Maltz and Susskind which conjectured a potentially rigorous framework where the status of de Sitter space is the same as that of a resonance in a scattering process. The conjecture being that transition amplitudes between certain states with asymptotically supersymmetric flat vacua contain resonant poles characteristic meta-stable intermediate states. A calculation employing constrained instantons is presented that illustrates this idea.
Stochastic resonance in a financial model
Institute of Scientific and Technical Information of China (English)
毛晓明; 孙锴; 欧阳颀
2002-01-01
We report on our model study of stochastic resonance in the stock market using numerical simulation and analysis.In the model, we take the interest rate as the external signal, the randomness of traders' behaviour as the noise, andthe stock price as the output. With computer simulations, we find that the system demonstrates a characteristic ofstochastic resonance as noise intensity varies. An analytical explanation is proposed.
Ring-Resonator/Sol-Gel Interferometric Immunosensor
Bearman, Gregory; Cohen, David
2007-01-01
A proposed biosensing system would be based on a combination of (1) a sensing volume containing antibodies immobilized in a sol-gel matrix and (2) an optical interferometer having a ring resonator configuration. The antibodies would be specific to an antigen species that one seeks to detect. In the ring resonator of the proposed system, light would make multiple passes through the sensing volume, affording greater interaction length and, hence, greater antibody- detection sensitivity.
de Sitter Space as a Resonance
Maltz, Jonathan; Susskind, Leonard
2017-03-01
A quantum mechanical formulation of de Sitter cosmological spacetimes still eludes string theory. In this Letter we conjecture a potentially rigorous framework in which the status of de Sitter space is the same as that of a resonance in a scattering process. We conjecture that transition amplitudes between certain states with asymptotically supersymmetric flat vacua contain resonant pole characteristic metastable intermediate states. A calculation employing constrained instantons illustrates this idea.
An Elimination of Resonance in Electric Drives
Directory of Open Access Journals (Sweden)
Michal Malek
2011-01-01
Full Text Available Flexible couplings together with resonance phenomenon are present mainly in the field of servodrives where high accuracy and dynamic requirements are crucial. When dynamics doesn’t correlate with mechanical system design, unwanted frequencies in the system are exited. Sometimes we haven’t conditions (whether material or space to design mechanical system with resonant frequencies too high to be exited. In that case we must choose compensating methods which can eliminate these phenomenons. This paper is dedicated to them.
Acoustic resonance phase locked photoacoustic spectrometer
Pilgrim, Jeffrey S.; Bomse, David S.; Silver, Joel A.
2003-08-19
A photoacoustic spectroscopy method and apparatus for maintaining an acoustic source frequency on a sample cell resonance frequency comprising: providing an acoustic source to the sample cell to generate a photoacoustic signal, the acoustic source having a source frequency; continuously measuring detection phase of the photoacoustic signal with respect to source frequency or a harmonic thereof; and employing the measured detection phase to provide magnitude and direction for correcting the source frequency to the resonance frequency.
Average resonance parameters evaluation for actinides
Energy Technology Data Exchange (ETDEWEB)
Porodzinskij, Yu.V.; Sukhovitskij, E.Sh. [Radiation Physics and Chemistry Problems Inst., Minsk-Sosny (Belarus)
1997-03-01
New evaluated <{Gamma}{sub n}{sup 0}> and
H∞ Loop shaping control for PLL-based mechanical resonance tracking in NEMS resonant mass sensors
Kharrat, Chady; Colinet, Eric; Voda, Alina
2008-01-01
International audience; Abstract--A simple dynamic detection of the resonance frequency shift in NEMS resonant mass sensors is described. This is done without the use of an external frequency sweep signal nor a frequency counter limiting the dynamic variation detection. Neither an amplitude control nor a phase switcher is required for maintaining the resonant oscillations. The sensor is driven directly by the VCO's output for which the control signal is calculated by a robust H∞ controller us...
Stochastic resonance and chaotic resonance in bimodal maps: A case study
Indian Academy of Sciences (India)
G Ambika; N V Sujatha; K P Harikrishnan
2002-09-01
We present the results of an extensive numerical study on the phenomenon of stochastic resonance in a bimodal cubic map. Both Gaussian random noise as well as deterministic chaos are used as input to drive the system between the basins. Our main result is that when two identical systems capable of stochastic resonance are coupled, the SNR of either system is enhanced at an optimum coupling strength. Our results may be relevant for the study of stochastic resonance in biological systems.
Acoustic resonance for nonmetallic mine detection
Energy Technology Data Exchange (ETDEWEB)
Kercel, S.W.
1998-04-01
The feasibility of acoustic resonance for detection of plastic mines was investigated by researchers at the Oak Ridge National Laboratory`s Instrumentation and Controls Division under an internally funded program. The data reported in this paper suggest that acoustic resonance is not a practical method for mine detection. Representative small plastic anti-personnel mines were tested, and were found to not exhibit detectable acoustic resonances. Also, non-metal objects known to have strong acoustic resonances were tested with a variety of excitation techniques, and no practical non-contact method of exciting a consistently detectable resonance in a buried object was discovered. Some of the experimental data developed in this work may be useful to other researchers seeking a method to detect buried plastic mines. A number of excitation methods and their pitfalls are discussed. Excitation methods that were investigated include swept acoustic, chopped acoustic, wavelet acoustic, and mechanical shaking. Under very contrived conditions, a weak response that could be attributed to acoustic resonance was observed, but it does not appear to be practical as a mine detection feature. Transfer properties of soil were investigated. Impulse responses of several representative plastic mines were investigated. Acoustic leakage coupling, and its implications as a disruptive mechanism were investigated.
Dynamics and Transit Variations of Resonant Exoplanets
Nesvorny, D
2016-01-01
The Transit Timing Variations (TTVs) are deviations of the measured mid-transit times from the exact periodicity. One of the most interesting causes of TTVs is the gravitational interaction between planets. Here we consider a case of two planets in a mean motion resonance (orbital periods in a ratio of small integers). This case is important because the resonant interaction can amplify the TTV effect and allow planets to be detected more easily. We develop an analytic model of the resonant dynamics valid for small orbital eccentricities and use it to derive the principal TTV terms. We find that a resonant system should show TTV terms with two basic periods (and their harmonics). The resonant TTV period is proportional (m/M_*)^(-2/3), where m and M_* are the planetary and stellar masses. For m=10^(-4) M_*, for example, the TTV period exceeds the orbital period by ~2 orders of magnitude. The amplitude of the resonant TTV terms scales linearly with the libration amplitude. The ratio of the TTV amplitudes of two ...
How the $\\gamma \\gamma$ Resonance Stole Christmas
Craig, Nathaniel; Kilic, Can; Thomas, Scott
2015-01-01
The experimental and theoretical implications of heavy di-gauge boson resonances that couple to, or are comprised of, new charged and strongly interacting matter are investigated. Observation and measurement of ratios of the resonant di-gauge boson channels $WW$, $ZZ$, $\\gamma \\gamma$, $Z \\gamma$, and $gg$ in the form of di-jets, provide a rather direct -- and for some ratios a rather robust -- probe of the gauge representations of the new matter. For a spin-zero resonance with the quantum numbers of the vacuum, the ratios of resonant $WW$ and $ZZ$ to $\\gamma \\gamma$ channels, as well as the longitudinal versus transverse polarization fractions in the $WW$ and $ZZ$ channels, provide extraordinarily sensitive probes for possible mixing with the Higgs boson, while di-Higgs and di-top resonant channels, $hh$ and $tt$, provide somewhat less sensitivity. We present a survey of possible underlying models for di-gauge boson resonances by considering various limits for the mass of the new charged and strongly interac...
Integrated plasmonic refractometric sensor using Fano resonance
Sherif, S. M.; Zografopoulos, D. C.; Shahada, L. A.; Beccherelli, R.; Swillam, M.
2017-02-01
We propose a plasmonic refractometric sensor that is based on Fano resonances excited in a resonant rectangular cavity coupled to a metal-insulator-metal bus waveguide. The properties of the resonances are controlled by varying the dimensions of the rectangular resonator and the observed Fano profile stems from the multimode interference of resonant cavity modes. We theoretically investigate the device’s performance as a highly sensitive refractometric plasmonic sensor which operates on gases, water and organic solvent solutions with tens of femtoliters of analyte. The sensor is studied in a wide operational range (0.7-2.7 μm) covering the entire near infrared spectral range, and is characterized by large sensitivity, which reaches 1550 nm RIU-1, and sensitivity per unit volume higher than 107 nm (RIU · nl)-1 at the resonant wavelength of 1.55 μm. The proposed plasmonic structure is very promising for integrated sensing applications owing to its small footprint and surprisingly simple layout.
Do resonating bells increase jellyfish swimming performance?
Hoover, Alexander; Miller, Laura
2013-11-01
A current question in swimming and flight is whether or not driving flexible appendages at their resonant frequency results in faster or more efficient locomotion. It has been suggested that jellyfish swim faster and/or more efficiently when the bell is driven at its resonant frequency. Previous work has modeled the jellyfish bell as a damped harmonic oscillator, and this simplified model suggests that work done by the bell is maximized when force is applied at the resonant frequency of the bell. We extend the idea of resonance phenomena of the jellyfish bell to a fluid structure interaction framework using the immersed boundary method. We first examine the effects of the bending stiffness of the bell on its resonant frequency. We then further our model with the inclusion of a ``muscular'' spring that connects the two sides of a 2D bell and drives it near its resonant frequency. We use this muscular spring to force the bell at varying frequencies and examine the work done by these springs and the resulting swimming speed. We finally augment our model with a flexible, passive bell margin to examine its role in propulsive efficiency.
Stochastic resonance during a polymer translocation process.
Mondal, Debasish; Muthukumar, M
2016-04-14
We have studied the occurrence of stochastic resonance when a flexible polymer chain undergoes a single-file translocation through a nano-pore separating two spherical cavities, under a time-periodic external driving force. The translocation of the chain is controlled by a free energy barrier determined by chain length, pore length, pore-polymer interaction, and confinement inside the donor and receiver cavities. The external driving force is characterized by a frequency and amplitude. By combining the Fokker-Planck formalism for polymer translocation and a two-state model for stochastic resonance, we have derived analytical formulas for criteria for emergence of stochastic resonance during polymer translocation. We show that no stochastic resonance is possible if the free energy barrier for polymer translocation is purely entropic in nature. The polymer chain exhibits stochastic resonance only in the presence of an energy threshold in terms of polymer-pore interactions. Once stochastic resonance is feasible, the chain entropy controls the optimal synchronization conditions significantly.
Directory of Open Access Journals (Sweden)
Hilmi Volkan Demir
2009-11-01
Full Text Available We present circular architecture bioimplant strain sensors that facilitate a strong resonance frequency shift with mechanical deformation. The clinical application area of these sensors is for in vivo assessment of bone fractures. Using a rectangular geometry, we obtain a resonance shift of 330 MHz for a single device and 170 MHz for its triplet configuration (with three side-by-side resonators on chip under an applied load of 3,920 N. Using the same device parameters with a circular isotropic architecture, we achieve a resonance frequency shift of 500 MHz for the single device and 260 MHz for its triplet configuration, demonstrating substantially increased sensitivity.
Guddala, Sriram; Narayana Rao, D.; Ramakrishna, S. Anantha
2016-06-01
A tri-layer metamaterial perfect absorber of light, consisting of (Al/ZnS/Al) films with the top aluminum layer patterned as an array of circular disk nanoantennas, is investigated for resonantly enhancing Raman scattering from C60 fullerene molecules deposited on the metamaterial. The metamaterial is designed to have resonant bands due to plasmonic and electromagnetic resonances at the Raman pump frequency (725 nm) as well as Stokes emission bands. The Raman scattering from C60 on the metamaterial with resonantly matched bands is measured to be enhanced by an order of magnitude more than C60 on metamaterials with off-resonant absorption bands peaking at 1090 nm. The Raman pump is significantly enhanced due to the resonance with a propagating surface plasmon band, while the highly impedance-matched electromagnetic resonance is expected to couple out the Raman emission efficiently. The nature and hybridization of the plasmonic and electromagnetic resonances to form compound resonances are investigated by numerical simulations.
14 CFR 29.663 - Ground resonance prevention means.
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground resonance prevention means. 29.663... Ground resonance prevention means. (a) The reliability of the means for preventing ground resonance must... or tests that malfunction or failure of a single means will not cause ground resonance. (b)...
14 CFR 27.663 - Ground resonance prevention means.
2010-01-01
... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground resonance prevention means. 27.663... resonance prevention means. (a) The reliability of the means for preventing ground resonance must be shown... that malfunction or failure of a single means will not cause ground resonance. (b) The probable...
Single crystal micromechanical resonator and fabrication methods thereof
Energy Technology Data Exchange (ETDEWEB)
Olsson, Roy H.; Friedmann, Thomas A.; Homeijer, Sara Jensen; Wiwi, Michael; Hattar, Khalid Mikhiel; Clark, Blythe; Bauer, Todd; Van Deusen, Stuart B.
2016-12-20
The present invention relates to a single crystal micromechanical resonator. In particular, the resonator includes a lithium niobate or lithium tantalate suspended plate. Also provided are improved microfabrication methods of making resonators, which does not rely on complicated wafer bonding, layer fracturing, and mechanical polishing steps. Rather, the methods allow the resonator and its components to be formed from a single crystal.
Theoretical and experimental investigation of microstrip rhombic resonators
Al-Charchafchi, S. H.; Boulkos, J.
1990-06-01
The resonant behavior of a novel microstrip rhombic resonator is investigated by analyzing an equivalent circuit based on transmission line modeling. Design curves showing the dependence of resonator performance on its parameters, as well as the substrate parameters, are presented. Experiments carried out showed a significant reduction in insertion loss when the rhombic resonator is dielectrically shielded. The resonator could be used as a microwave bandpass filter or a stabilization circuit for microwave oscillators in both hybrid and monolithic integrated circuits.
Cryogenic resonator design for trapped ion experiments in Paul traps
Brandl, Matthias F; Monz, Thomas; Blatt, Rainer
2016-01-01
Trapping ions in Paul traps requires high radio-frequency voltages, which are generated using resonators. When operating traps in a cryogenic environment, an in-vacuum resonator showing low loss is crucial to limit the thermal load to the cryostat. In this study, we present a guide for the design and production of compact, shielded cryogenic resonators. We produced and characterized three different types of resonators and furthermore demonstrate efficient impedance matching of these resonators at cryogenic temperatures.
Directory of Open Access Journals (Sweden)
van Rossum Albert C
2009-03-01
Full Text Available Abstract These reporting guidelines are recommended by the Society for Cardiovascular Magnetic Resonance (SCMR to provide a framework for healthcare delivery systems to disseminate cardiac and vascular imaging findings related to the performance of cardiovascular magnetic resonance (CMR examinations.
Revising the $f_1(1420)$ resonance
Debastiani, V R; Liang, Wei-Hong; Oset, E
2016-01-01
We have studied the production and decay of the $f_1(1285)$ into $\\pi a_0(980)$ and $K^* \\bar K$ as a function of the mass of the resonance and find a shoulder around 1400 MeV, tied to a triangle singularity, for the $\\pi a_0(980)$ mode, and a peak around 1420 MeV with about 60 MeV width for the $K^* \\bar K$ mode. Both these features agree with the experimental information on which the $f_1(1420)$ resonance is based. In addition, we find that if the $f_1(1420)$ is a genuine resonance, coupling mostly to $K^* \\bar K$ as seen experimentally, one finds unavoidably about a 20\\% fraction for $\\pi a_0(980)$ decay of this resonance, in drastic contradiction with all experiments. Altogether, we conclude that the $f_1(1420)$ is not a genuine resonance, but the manifestation of the $\\pi a_0(980)$ and $K^* \\bar K$ decay modes of the $f_1(1285)$ at higher energies than the nominal one.
Scattering by coupled resonating elements in air
Krynkin, Anton; Chong, Alvin Y B; Taherzadeh, Shahram; Attenborough, Keith
2011-01-01
Scattering by (a) a single composite scatterer consisting of a concentric arrangement of an outer N-slit rigid cylinder and an inner cylinder which is either rigid or in the form of a thin elastic shell and (b) by a finite periodic array of these scatterers in air has been investigated analytically and through laboratory experiments. The composite scatterer forms a system of coupled resonators and gives rise to multiple low frequency resonances. The corresponding analytical model employs polar angle dependent boundary conditions on the surface of the N-slit cylinder. The solution inside the slits assumes plane waves. It is shown also that in the low-frequency range the N-slit rigid cylinder can be replaced by an equivalent fluid layer. Further approximations suggest a simple square root dependence of the resonant frequencies on the number of slits and this is confirmed by data. The observed resonant phenomena are associated with Helmholtz-like behaviour of the resonator for which the radius and width of the o...
Simplified limits on resonances at the LHC
Chivukula, R. Sekhar; Ittisamai, Pawin; Mohan, Kirtimaan; Simmons, Elizabeth H.
2016-11-01
In the earliest stages of evaluating new collider data, especially if a small excess may be present, it would be useful to have a method for comparing the data with entire classes of models, to get an immediate sense of which classes could conceivably be relevant. In this paper, we propose a method that applies when the new physics invoked to explain the excess corresponds to the production and decay of a single, relatively narrow, s -channel resonance. A simplifed model of the resonance allows us to convert an estimated signal cross section into general bounds on the product of the branching ratios corresponding to the dominant production and decay modes. This quickly reveals whether a given class of models could possibly produce a signal of the required size at the LHC. Our work sets up a general framework, outlines how it operates for resonances with different numbers of production and decay modes, and analyzes cases of current experimental interest, including resonances decaying to dibosons, diphotons, dileptons, or dijets. If the LHC experiments were to report their searches for new resonances beyond the standard model in the simplified limits variable ζ defined in this paper, that would make it far easier to avoid blind alleys and home in on the most likely candidate models to explain any observed excesses.
Mechanical Resonances of Helically Coiled Carbon Nanowires
Saini, D.; Behlow, H.; Podila, R.; Dickel, D.; Pillai, B.; Skove, M. J.; Serkiz, S. M.; Rao, A. M.
2014-07-01
Despite their wide spread applications, the mechanical behavior of helically coiled structures has evaded an accurate understanding at any length scale (nano to macro) mainly due to their geometrical complexity. The advent of helically coiled micro/nanoscale structures in nano-robotics, nano-inductors, and impact protection coatings has necessitated the development of new methodologies for determining their shear and tensile properties. Accordingly, we developed a synergistic protocol which (i) integrates analytical, numerical (i.e., finite element using COMSOL®) and experimental (harmonic detection of resonance; HDR) methods to obtain an empirically validated closed form expression for the shear modulus and resonance frequency of a singly clamped helically coiled carbon nanowire (HCNW), and (ii) circumvents the need for solving 12th order differential equations. From the experimental standpoint, a visual detection of resonances (using in situ scanning electron microscopy) combined with HDR revealed intriguing non-planar resonance modes at much lower driving forces relative to those needed for linear carbon nanotube cantilevers. Interestingly, despite the presence of mechanical and geometrical nonlinearities in the HCNW resonance behavior the ratio of the first two transverse modes f2/f1 was found to be similar to the ratio predicted by the Euler-Bernoulli theorem for linear cantilevers.
Energy localization in weakly dissipative resonant chains
Kovaleva, Agnessa
2016-08-01
Localization of energy in oscillator arrays has been of interest for a number of years, with special attention paid to the role of nonlinearity and discreteness in the formation of localized structures. This work examines a different type of energy localization arising due to the presence of dissipation in nonlinear resonance arrays. As a basic model, we consider a Klein-Gordon chain of finite length subjected to a harmonic excitation applied at an edge of the chain. It is shown that weak dissipation may be a key factor preventing the emergence of resonance in the entire chain, even if its nondissipative analog is entirely captured into resonance. The resulting process in the dissipative oscillator array represents large-amplitude resonant oscillations in a part of the chain adjacent to the actuator and small-amplitude oscillations in the distant part of the chain. The conditions of the emergence of resonance as well as the conditions of energy localization are derived. An agreement between the obtained analytical results and numerical simulations is demonstrated.
Electrodynamic study of YIG filters and resonators
Krupka, Jerzy; Salski, Bartlomiej; Kopyt, Pawel; Gwarek, Wojciech
2016-01-01
Numerical solutions of coupled Maxwell and Landau-Lifshitz-Gilbert equations for a magnetized yttrium iron garnet (YIG) sphere acting as a one-stage filter are presented. The filter is analysed using finite-difference time-domain technique. Contrary to the state of the art, the study shows that the maximum electromagnetic power transmission through the YIG filter occurs at the frequency of the magnetic plasmon resonance with the effective permeability of the gyromagnetic medium μr ≈ −2, and not at a ferromagnetic resonance frequency. Such a new understanding of the YIG filter operation, makes it one of the most commonly used single-negative plasmonic metamaterials. The frequency of maximum transmission is also found to weakly depend on the size of the YIG sphere. An analytic electromagnetic analysis of resonances in a YIG sphere is performed for circularly polarized electromagnetic fields. The YIG sphere is situated in a free space and in a large spherical cavity. The study demonstrates that both volume resonances and magnetic plasmon resonances can be solutions of the same transcendental equations. PMID:27698467
Terahertz molecular resonance of cancer DNA
Cheon, Hwayeong; Yang, Hee-Jin; Lee, Sang-Hun; Kim, Young A.; Son, Joo-Hiuk
2016-11-01
Carcinogenesis involves the chemical and structural alteration of biomolecules in cells. Aberrant methylation of DNA is a well-known carcinogenic mechanism and a common chemical modification of DNA. Terahertz waves can directly observe changes in DNA because the characteristic energies lie in the same frequency region. In addition, terahertz energy levels are not high enough to damage DNA by ionization. Here, we present terahertz molecular resonance fingerprints of DNA methylation in cancer DNA. Methylated cytidine, a nucleoside, has terahertz characteristic energies that give rise to the molecular resonance of methylation in DNA. Molecular resonance is monitored in aqueous solutions of genomic DNA from cancer cell lines using a terahertz time-domain spectroscopic technique. Resonance signals can be quantified to identify the types of cancer cells with a certain degree of DNA methylation. These measurements reveal the existence of molecular resonance fingerprints of cancer DNAs in the terahertz region, which can be utilized for the early diagnosis of cancer cells at the molecular level.
Resonant non-Gaussianity with equilateral properties
Energy Technology Data Exchange (ETDEWEB)
Gwyn, Rhiannon [Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Potsdam (Germany); Rummel, Markus [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Westphal, Alexander [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
2012-11-15
We discuss the effect of superimposing multiple sources of resonant non-Gaussianity, which arise for instance in models of axion inflation. The resulting sum of oscillating shape contributions can be used to ''Fourier synthesize'' different non-oscillating shapes in the bispectrum. As an example we reproduce an approximately equilateral shape from the superposition of O(10) oscillatory contributions with resonant shape. This implies a possible degeneracy between the equilateral-type non-Gaussianity typical of models with non-canonical kinetic terms, such as DBI inflation, and an equilateral-type shape arising from a superposition of resonant-type contributions in theories with canonical kinetic terms. The absence of oscillations in the 2-point function together with the structure of the resonant N-point functions, imply that detection of equilateral non-Gaussianity at a level greater than the PLANCK sensitivity of f{sub NL} {proportional_to}O(5) will rule out a resonant origin. We comment on the questions arising from possible embeddings of this idea in a string theory setting.
Embroidered Coils for Magnetic Resonance Sensors
Directory of Open Access Journals (Sweden)
Michael I. Newton
2013-04-01
Full Text Available Magnetic resonance imaging is a widely used technique for medical and materials imaging. Even though the objects being imaged are often irregularly shaped, suitable coils permitting the measurement of the radio-frequency signal in these systems are usually made of solid copper. One problem often encountered is how to ensure the coils are both in close proximity and conformal to the object being imaged. Whilst embroidered conductive threads have previously been used as antennae in mobile telecommunications applications, they have not previously been reported for use within magnetic resonance. In this paper we show that an embroidered single loop coil can be used in a commercial unilateral nuclear magnetic resonance system as an alternative to a solid copper. Data is presented showing the determination of both longitudinal (T1 and effective transverse (T2eff relaxation times for a flat fabric coil and the same coil conformed to an 8 cm diameter cylinder. We thereby demonstrate the principles required for the wider use of fabric based conformal coils within nuclear magnetic resonance and magnetic resonance imaging.
REVISITING JOVIAN-RESONANCE INDUCED CHONDRULE FORMATION
Energy Technology Data Exchange (ETDEWEB)
Nagasawa, M. [Interactive Research Center of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Tanaka, K. K.; Tanaka, H. [Institute of Low Temperature Science, Hokkaido University, Kita-19, Nishi-8, Kita-ku, Sapporo 060-0819 (Japan); Nakamoto, T. [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Miura, H. [Graduate School of Natural Sciences, Nagoya City University, 1 Yamanohata, Mizuho-cho, Mizuho-ku, Nagoya 467-8501 (Japan); Yamamoto, T., E-mail: nagasawa.m.ad@m.titech.ac.jp [Center for Planetary Science, Kobe University, 7-1-48 Minamimachi, Minatojima, Chuo-ku, Kobe 650-0047 (Japan)
2014-10-10
It is proposed that planetesimals perturbed by Jovian mean-motion resonances are the source of shock waves that form chondrules. It is considered that this shock-induced chondrule formation requires the velocity of the planetesimal relative to the gas disk to be on the order of ≳ 7 km s{sup –1} at 1 AU. In previous studies on planetesimal excitation, the effects of Jovian mean-motion resonance together with the gas drag were investigated, but the velocities obtained were at most 8 km s{sup –1} in the asteroid belt, which is insufficient to account for the ubiquitous existence of chondrules. In this paper, we reexamine the effect of Jovian resonances and take into account the secular resonance in the asteroid belt caused by the gravity of the gas disk. We find that the velocities relative to the gas disk of planetesimals a few hundred kilometers in size exceed 12 km s{sup –1}, and that this is achieved around the 3:1 mean-motion resonance. The heating region is restricted to a relatively narrowband between 1.5 AU and 3.5 AU. Our results suggest that chondrules were produced effectively in the asteroid region after Jovian formation. We also find that many planetesimals are scattered far beyond Neptune. Our findings can explain the presence of crystalline silicate in comets if the scattered planetesimals include silicate dust processed by shock heating.
Magnetic resonance imaging of iliotibial band syndrome.
Ekman, E F; Pope, T; Martin, D F; Curl, W W
1994-01-01
Seven cases of iliotibial band syndrome and the pathoanatomic findings of each, as demonstrated by magnetic resonance imaging, are presented. These findings were compared with magnetic resonance imaging scans of 10 age- and sex-matched control knees without evidence of lateral knee pain. Magnetic resonance imaging signal consistent with fluid was seen deep to the iliotibial band in the region of the lateral femoral epicondyle in five of the seven cases. Additionally, when compared with the control group, patients with iliotibial band syndrome demonstrated a significantly thicker iliotibial band over the lateral femoral epicondyle (P iliotibial band in the disease group was 5.49 +/- 2.12 mm, as opposed to 2.52 +/- 1.56 mm in the control group. Cadaveric dissections were performed on 10 normal knees to further elucidate the exact nature of the area under the iliotibial band. A potential space, i.e., a bursa, was found between the iliotibial band and the knee capsule. This series suggests that magnetic resonance imaging demonstrates objective evidence of iliotibial band syndrome and can be helpful when a definitive diagnosis is essential. Furthermore, correlated with anatomic dissection, magnetic resonance imaging identifies this as a problem within a bursa beneath the iliotibial band and not a problem within the knee joint.
Resonant response of electromagnetic scattering from ellipsoid
Gavriloaia, Mihai-Bogdan; Vizireanu, Constantin-Radu; Neamtu, Catalin; Preda, Radu; Achimescu, Emanuel; Halunga, Simona
2015-02-01
Modern radars must provide in a very short time: existence, mobility and shape of objects evolving in airspace. Evaluation of the object shapes through active research by using synthetic aperture radar is limited in time, resolution, and cost. A new way of processing non-stationary signals is presented in this article. Signals are obtained from the reflection of the electromagnetic field by objects with complex shape when they are irradiated with linear frequency modulated signals. The amplitude of reflected signal is variable on the radio-impulse duration depending on object shape, causing a certain electromagnetic signature. This phenomenon is caused by specific electromagnetic resonance. The reflected signal has maximum amplitude when the frequency of the incident wave is the same with the resonant frequency of the investigated object. The structure of an radar target can be decomposed into simple geometric shapes such as spheres, ellipsoids, prisms, and so on. Using resonant effect that ensures pattern recognition is exemplified by an object with an aerodynamic profile accepted in many component elements of the aircraft, namely - an ellipsoid. It is a geometric shape used extensively in aviation, because it has a very low aerodynamic resistance. The resonant response of ellipsoid is evaluated in a decade frequency band, but the pattern recognition of this shape is enough for an octave band. The resonant response is assessed for cross polarization of incident electromagnetic field, as well. As a result, the radio-impulse shape can be used in a data base for pattern recognition.
Short-circuit protection of LLC resonant converter using voltages across resonant tank elements
Directory of Open Access Journals (Sweden)
Denys Igorovych Zaikin
2015-06-01
Full Text Available This paper describes two methods for the short-circuit protection of the LLC resonant converter. One of them uses the voltage across the capacitor and the other uses the voltage across the inductor of the resonant tank. These voltages can be processed (integrated or differentiated to recover the resonant tank current. The two circuits illustrated in the described methods make it possible to develop a robust LLC converter design and to avoid using lossy current measurement elements, such as a shunt resistor or current transformer. The methods also allow measuring resonant tank current without breaking high-current paths and connecting the measuring circuit in parallel with the inductor or capacitor of the resonant tank. Practical implementations of these indirect current measurements have been experimentally tested for the short-circuit protection of the 1600 W LLC converter.
Multi-resonance tunneling of acoustic waves in two-dimensional locally-resonant phononic crystals
Yang, Aichao; He, Wei; Zhang, Jitao; Zhu, Liang; Yu, Lingang; Ma, Jian; Zou, Yang; Li, Min; Wu, Yu
2017-03-01
Multi-resonance tunneling of acoustic waves through a two-dimensional phononic crystal (PC) is demonstrated by substituting dual Helmholtz resonators (DHRs) for acoustically-rigid scatterers in the PC. Due to the coupling of the incident waves with the acoustic multi-resonance modes of the DHRs, acoustic waves can tunnel through the PC at specific frequencies which lie inside the band gaps of the PC. This wave tunneling transmission can be further broadened by using the multilayer Helmholtz resonators. Thus, a PC consisting of an array of dual/multilayer Helmholtz resonators can serve as an acoustic band-pass filter, used to pick out acoustic waves with certain frequencies from noise.
Local resonance and Bragg bandgaps in sandwich beams containing periodically inserted resonators
Sharma, Bhisham
2015-01-01
We study the low frequency wave propagation behavior of sandwich beams containing periodically embedded internal resonators. A closed form expression for the propagation constant is obtained using a phased array approach and verified using finite element simulations. We show that local resonance and Bragg bandgaps coexist in such a system and that the width of both bandgaps is a function of resonator parameters as well as their periodicity. The interaction between the two bandgaps is studied by varying the local resonance frequency. We find that a single combined bandgap does not exist for this system and that the Bragg bandgaps transition into sub-wavelength bandgaps when the local resonance frequency is above their associated classical Bragg frequency.
Gil-Santos, Eduardo; Baker, Christopher; Lemaître, Aristide; Gomez, Carmen; Leo, Giuseppe; Favero, Ivan
2017-01-01
Photonic lattices of mutually interacting indistinguishable cavities represent a cornerstone of collective phenomena in optics and could become important in advanced sensing or communication devices. The disorder induced by fabrication technologies has so far hindered the development of such resonant cavity architectures, while post-fabrication tuning methods have been limited by complexity and poor scalability. Here we present a new simple and scalable tuning method for ensembles of microphotonic and nanophotonic resonators, which enables their permanent collective spectral alignment. The method introduces an approach of cavity-enhanced photoelectrochemical etching in a fluid, a resonant process triggered by sub-bandgap light that allows for high selectivity and precision. The technique is presented on a gallium arsenide nanophotonic platform and illustrated by finely tuning one, two and up to five resonators. It opens the way to applications requiring large networks of identical resonators and their spectral referencing to external etalons.
Resonance control of mid-infrared metamaterials using arrays of split-ring resonator pairs
Yue, Weisheng
2016-01-11
We present our design, fabrication and characterization of resonance-controllable metamaterials operating at mid-infrared wavelengths. The metamaterials are composed of pairs of back-to-back or face-to-face U-shape split-ring resonators (SRRs). Transmission spectra of the metamaterials are measured using Fourier-transform infrared spectroscopy. The results show that the transmission resonance is dependent on the distance between the two SRRs in each SRR pair. The dips in the transmission spectrum shift to shorter wavelengths with increasing distance between the two SRRs for both the back-to-back and face-to-face SRR pairs. The position of the resonance dips in the spectrum can hence be controlled by the relative position of the SRRs. This mechanism of resonance control offers a promising way of developing metamaterials with tunability for optical filters and bio/chemical sensing devices in integrated nano-optics.
Resonance control of mid-infrared metamaterials using arrays of split-ring resonator pairs.
Yue, Weisheng; Wang, Zhihong; Whittaker, John; Schedin, Fredrik; Wu, Zhipeng; Han, Jiaguang
2016-02-01
We present our design, fabrication and characterization of resonance-controllable metamaterials operating at mid-infrared wavelengths. The metamaterials are composed of pairs of back-to-back or face-to-face U-shape split-ring resonators (SRRs). Transmission spectra of the metamaterials are measured using Fourier-transform infrared spectroscopy. The results show that the transmission resonance is dependent on the distance between the two SRRs in each SRR pair. The dips in the transmission spectrum shift to shorter wavelengths with increasing distance between the two SRRs for both the back-to-back and face-to-face SRR pairs. The position of the resonance dips in the spectrum can hence be controlled by the relative position of the SRRs. This mechanism of resonance control offers a promising way of developing metamaterials with tunability for optical filters and bio/chemical sensing devices in integrated nano-optics.
Resonance decay effect on conserved number fluctuations in a hadron resonance gas model
Mishra, D K; Netrakanti, P K; Mohanty, A K
2016-01-01
We study the effect of charged secondaries coming from resonance decay on the net-baryon, net-charge and net-strangeness fluctuations in high energy heavy-ion collisions within the hadron resonance gas (HRG) model. We emphasize the importance of including weak decays along with other resonance decays in the HRG, while comparing with the experimental observables. The effect of kinematic cuts on resonances and primordial particles on the conserved number fluctuations are also studied. The HRG model calculations with the inclusion of resonance decays and kinematical cuts are compared with the recent experimental data from STAR and PHENIX experiments. We find a good agreement between our model calculations and the experimental measurements for both net-proton and net-charge distributions.
Effect of resonance decay on conserved number fluctuations in a hadron resonance gas model
Mishra, D. K.; Garg, P.; Netrakanti, P. K.; Mohanty, A. K.
2016-07-01
We study the effect of charged secondaries coming from resonance decay on the net-baryon, net-charge, and net-strangeness fluctuations in high-energy heavy-ion collisions within the hadron resonance gas (HRG) model. We emphasize the importance of including weak decays along with other resonance decays in the HRG, while comparing with the experimental observables. The effect of kinematic cuts on resonances and primordial particles on the conserved number fluctuations are also studied. The HRG model calculations with the inclusion of resonance decays and kinematical cuts are compared with the recent experimental data from STAR and PHENIX experiments. We find good agreement between our model calculations and the experimental measurements for both net-proton and net-charge distributions.
Exotic baryon resonances in the Skyrme model
Diakonov, Dmitri
2008-01-01
We outline how one can understand the Skyrme model from the modern perspective. We review the quantization of the SU(3) rotations of the Skyrmion, leading to the exotic baryons that cannot be made of three quarks. It is shown that in the limit of large number of colours the lowest-mass exotic baryons can be studied from the kaon-Skyrmion scattering amplitudes, an approach known after Callan and Klebanov. We follow this approach and find, both analytically and numerically, a strong Theta+ resonance in the scattering amplitude that is traced to the rotational mode. The Skyrme model does predict an exotic resonance Theta+ but grossly overestimates the width. To understand better the factors affecting the width, it is computed by several methods giving, however, identical results. In particular, we show that insofar as the width is small, it can be found from the transition axial constant. The physics leading to a narrow Theta+ resonance is briefly reviewed and affirmed.
Resonant Behavior of an Augmented Railgun
Bahder, Thomas B
2011-01-01
We consider a lumped circuit model of an augmented electromagnetic railgun that consists of a gun circuit and an augmentation circuit that is inductively coupled to the gun circuit. The gun circuit is driven by a d.c. voltage generator, and the augmentation circuit is driven by an a.c. voltage generator. Using sample parameters, we numerically solve the three non-linear dynamical equations that describe this system. We find that there is a resonant behavior in the armature kinetic energy as a function of the frequency of the voltage generator in the augmentation circuit. This resonant behavior may be exploited to increase armature kinetic energy. Alternatively, if the presence of the kinetic energy resonance is not taken into account, parameters may be chosen that result in less than optimal kinetic energy and efficiency.
Study of acoustic resonance of cascades
Honjo, M.; Tominaga, T.
Discrete sounds and vibrations from guide vanes due to acoustic resonance in the vane flow path, are experimentally investigated. Other causes of pure sounds in stationary vanes are considered, such as direct radiation from wake shedding vortices, bubble vortices or leading edges, and radial or axial modes of air columns. Two-dimensional cascade tests are performed under various conditions, and the data are compared with theoretical results of flat plate cascades. Three-dimensional ducted guide vane model tests are carried out to apply prototype guide vanes, and to confirm the resonance of the two-dimensional tests. Results show that frequency is more sensitive to chord length than pitch length, and the ratio of the fluctuation frequency to fluid sound velocity/pitch length is independent of the scale. Bubble vortices on concave surfaces or leading edges are not exciting sources; and under the limit of solidity, no exciting energy can generate acoustic resonance in correspondence to the mode.
Gas lasers with wave-chaotic resonators
Zaitsev, Oleg
2010-01-01
Semiclassical multimode laser theory is extended to gas lasers with open two-dimensional resonators of arbitrary shape. The Doppler frequency shift of the linear-gain coefficient leads to an additional linear coupling between the modes, which, however, is shown to be negligible. The nonlinear laser equations simplify in the special case of wave-chaotic resonators. In the single-mode regime, the intensity of a chaotic laser, as a function of the mode frequency, displays a local minimum at the frequency of the atomic transition. The width of the minimum scales with the inhomogeneous linewidth, in contrast to the Lamb dip in uniaxial resonators whose width is given by the homogeneous linewidth.
Preheating with Trilinear Interactions: Tachyonic Resonance
Dufaux, J F; Kofman, L; Peloso, M; Podolsky, D
2006-01-01
We investigate the effects of bosonic trilinear interactions in preheating after chaotic inflation. A trilinear interaction term allows for the complete decay of the massive inflaton particles, which is necessary for the transition to radiation domination. We found that typically the trilinear term is subdominant during early stages of preheating, but it actually amplifies parametric resonance driven by the four-legs interaction. In cases where the trilinear term does dominate during preheating, the process occurs through periodic tachyonic amplifications with resonance effects, which is so effective that preheating completes within a few inflaton oscillations. We develop an analytic theory of this process, which we call tachyonic resonance. We also study numerically the influence of trilinear interactions on the dynamics after preheating. The trilinear term eventually comes to dominate after preheating, leading to faster rescattering and thermalization than could occur without it. Finally, we investigate the...
Probabilistic interpretation of compositeness relation for resonances
Guo, Zhi-Hui
2015-01-01
Bound, antibound and resonances states are associated to poles in the on-shell partial wave amplitudes. We show here that from the residues of the pole a rank 1 projection operator associated with any of these states can be extracted, in terms of which a sum rule related to the composition of the state can be derived. Although typically it involves complex coefficients for the compositeness and elementariness, except for the bound state case, we demonstrate that one can formulate a meaningful compositeness relation with only positive coefficients for resonances whose associated Laurent series in the variable $s$ converges in a region of the physical axis around its squared mass. We apply this formalism to study the two-body components of several resonances of interest.
Rectangular Laser Resonators with Astigmatic Compensation
DEFF Research Database (Denmark)
Skettrup, Torben
2005-01-01
An investigation of rectangular resonators with a view to the compensation of astigmatism has been performed. In order to have beam waists placed at the same positions in the tangential and sagittal planes, pairs of equal mirrors were considered. It was found that at least two concave mirrors...... are necessary to obtain compensation. Four-concave-mirror systems are most stable close to the quadratic geometry, although the symmetric quadratic resonator itself cannot be compensated for astigmatism. Using four equal concave mirrors, compensation of astigmatism can be obtained in two arms at the same time....... Usually several stability ranges are found for four-mirror resonators with pair-wise equal mirrors, and it is possible with these systems to obtain small compensated beam waist radii suitable for frequency conversion. Relevant formulae are given and several relevant examples are shown using simulation...
Wideband P-Shaped Dielectric Resonator Antenna
Directory of Open Access Journals (Sweden)
M.Khalily
2013-04-01
Full Text Available A novel P-shaped dielectric resonator antenna (DRA is presented and investigated for wideband wireless application. By using P-shaped resonator, a wideband impedance bandwidth of 80% from 3.5 to 8.2 GHz is achieved. The antenna covers all of wireless systems like C-band, 5.2, 5.5 and 5.8 GHz-WLAN and WiMax. The proposed antenna has a low profile and the thickness of the resonator is only 5.12 mm, which is 0.06-0.14 free space wavelength. A parametric study is presented. The proposed DRA is built and the characteristics of the antenna are measured. Very good agreement between numerical and measured results is obtained.
Resonant charge transfer at dielectric surfaces
Marbach, Johannes; Fehske, Holger
2012-01-01
We report on the theoretical description of secondary electron emission due to resonant charge transfer occurring during the collision of metastable nitrogen molecules with dielectric surfaces. The emission is described as a two step process consisting of electron capture to form an intermediate shape resonance and subsequent electron emission by decay of this ion, either due to its natural life time or its interaction with the surface. The electron capture is modeled using the Keldysh Green's function technique and the negative ion decay is described by a combination of the Keldysh technique and a rate equation approach. We find the resonant capture of electrons to be very efficient and the natural decay to be clearly dominating over the surface-induced decay. Secondary electron emission coefficients are calculated for aluminum oxide, magnesium oxide, silicon oxide, and diamond at several kinetic energies of the projectile. With the exception of magnesium oxide the coefficients turn out to be of the order of...
Aptasensors Based on Whispering Gallery Mode Resonators
Nunzi Conti, Gualtiero; Berneschi, Simome; Soria, Silvia
2016-01-01
In this paper, we review the literature on optical evanescent field sensing in resonant cavities where aptamers are used as biochemical receptors. The combined advantages of highly sensitive whispering gallery mode resonator (WGMR)-based transducers, and of the unique properties of aptamers make this approach extremely interesting in the medical field, where there is a particularly high need for devices able to provide real time diagnosis for cancer, infectious diseases, or strokes. However, despite the superior performances of aptamers compared to antibodies and WGMR to other evanescent sensors, there is not much literature combining both types of receptors and transducers. Up to now, the WGMR that have been used are silica microspheres and silicon oxynitride (SiON) ring resonators. PMID:27438861
Origin of coda waves: earthquake source resonance
Liu, Yinbin
2015-01-01
Seismic coda in local earthquake exhibits the characteristics of uniform spatial distribution energy, selective frequency, and slow temporal decay oscillation. It is usually assumed to be the incoherent waves scattered from random heterogeneity in the earth's lithosphere. Here I show by wave field modeling for 1D heterogeneity that seismic coda is related to the natural resonance of earthquake source around the earthquake's focus. This natural resonance is a kind of wave coherent scattering enhancement phenomenon or coupling oscillations happened in steady state regime in strong small-scale heterogeneity. Its resonance frequency is inversely proportional to the heterogeneous scale and contrast and will shift toward lower frequency with increasing random heterogeneous scale and velocity fluctuations. Its energy weakens with decreasing impedance contrast and increasing random heterogeneous scale and velocity fluctuations.
An investigation on wind turbine resonant vibrations
DEFF Research Database (Denmark)
Tibaldi, Carlo; Kim, Taeseong; Larsen, Torben J.
2016-01-01
in the modeling can have a large influence on the vibration level. The edgewise vibrations are less visible in high turbulent conditions. Using simulations with low-level turbulence intensity will ease this identification and could avoid a redesign. Furthermore, depending on the external excitation, different......Wind turbine resonant vibrations are investigated based on aeroelastic simulations both in frequency and time domain. The investigation focuses on three different aspects: the need of a precise modeling when a wind turbine is operating close to resonant conditions; the importance of estimating wind......, the frequencies at which minimal excitation should be present during operations. The study shows that significant edgewise blade vibrations can occur on modern wind turbines even if the aeroelastic damping of the edgewise modes is positive. When operating close to resonant conditions, small differences...
Resonance Van Hove Singularities in Wave Kinetics
Shi, Yi-Kang
2015-01-01
Wave kinetic theory has been developed to describe the statistical dynamics of weakly nonlinear, dispersive waves. However, we show that systems which are generally dispersive can have resonant sets of wave modes with identical group velocities, leading to a local breakdown of dispersivity. This shows up as a geometric singularity of the resonant manifold and possibly as an infinite phase measure in the collision integral. Such singularities occur widely for classical wave systems, including acoustical waves, Rossby waves, helical waves in rotating fluids, light waves in nonlinear optics and also in quantum transport, e.g. kinetics of electron-hole excitations (matter waves) in graphene. These singularities are the exact analogue of the critical points found by Van Hove in 1953 for phonon dispersion relations in crystals. The importance of these singularities in wave kinetics depends on the dimension of phase space $D=(N-2)d$ ($d$ physical space dimension, $N$ the number of waves in resonance) and the degree ...
Multilayer Integrated Film Bulk Acoustic Resonators
Zhang, Yafei
2013-01-01
Multilayer Integrated Film Bulk Acoustic Resonators mainly introduces the theory, design, fabrication technology and application of a recently developed new type of device, multilayer integrated film bulk acoustic resonators, at the micro and nano scale involving microelectronic devices, integrated circuits, optical devices, sensors and actuators, acoustic resonators, micro-nano manufacturing, multilayer integration, device theory and design principles, etc. These devices can work at very high frequencies by using the newly developed theory, design, and fabrication technology of nano and micro devices. Readers in fields of IC, electronic devices, sensors, materials, and films etc. will benefit from this book by learning the detailed fundamentals and potential applications of these advanced devices. Prof. Yafei Zhang is the director of the Ministry of Education’s Key Laboratory for Thin Films and Microfabrication Technology, PRC; Dr. Da Chen was a PhD student in Prof. Yafei Zhang’s research group.
A Diphoton Resonance from Bulk RS
Csaki, Csaba
2016-01-01
Recent LHC data hints at a 750 GeV mass resonance that decays into two photons. A significant feature of this resonance is that its decays to Higges and to any other Standard Model particles are so far too low to be detected. Such a state has a compelling explanation in terms of a scalar or a pseudoscalar that is strongly coupled to vector states charged under the Standard Model gauge groups. We argue that if the state is a scalar, some form of sequestering is likely to be necessary to naturally explain the suppressed scalar-Higgs interactions. Such a scenario is readily accommodated in bulk RS with a scalar localized in the bulk away from the Higgs. Turning this around, we argue that a good way to find the elusive bulk RS model might be the search for a resonance with prominent couplings to gauge bosons.
Random search for a dark resonance
Kiilerich, Alexander Holm; Mølmer, Klaus
2017-02-01
A pair of resonant laser fields can drive a three-level system into a dark state where it ceases to absorb and emit radiation due to destructive interference. We propose a scheme to search for this resonance by randomly changing the frequency of one of the fields each time a fluorescence photon is detected. The longer the system is probed, the more likely the frequency is close to resonance and the system populates the dark state. Due to the correspondingly long waiting times between detection events, the evolution is nonergodic and the precision of the frequency estimate does not follow from the conventional Cramér-Rao bound of parameter estimation. Instead, a Lévy statistical analysis yields the scaling of the estimation error with time for precision probing of this kind.
A sound absorbing metasurface with coupled resonators
Li, Junfei; Wang, Wenqi; Xie, Yangbo; Popa, Bogdan-Ioan; Cummer, Steven A.
2016-08-01
An impedance matched surface is able, in principle, to totally absorb the incident sound and yield no reflection, and this is desired in many acoustic applications. Here we demonstrate a design of impedance matched sound absorbing surface with a simple construction. By coupling different resonators and generating a hybrid resonance mode, we designed and fabricated a metasurface that is impedance-matched to airborne sound at tunable frequencies with subwavelength scale unit cells. With careful design of the coupled resonators, over 99% energy absorption at central frequency of 511 Hz with a 50% absorption bandwidth of 140 Hz is achieved experimentally. The proposed design can be easily fabricated, and is mechanically stable. The proposed metasurface can be used in many sound absorption applications such as loudspeaker design and architectural acoustics.
A diphoton resonance from bulk RS
Csáki, Csaba; Randall, Lisa
2016-07-01
Recent LHC data hinted at a 750 GeV mass resonance that decays into two photons. A significant feature of this resonance is that its decays to any other Standard Model particles would be too low to be detected so far. Such a state has a compelling explanation in terms of a scalar or a pseudoscalar that is strongly coupled to vector states charged under the Standard Model gauge groups. Such a scenario is readily accommodated in bulk RS with a scalar localized in the bulk away from but close to the Higgs. Turning this around, we argue that a good way to find the elusive bulk RS model might be the search for a resonance with prominent couplings to gauge bosons.
Temperature Sensors Based on WGM Optical Resonators
Savchenkov, Anatoliy; Yu, Nan; Maleki, Lute; Itchenko, Vladimir; Matsko, Andrey; Strekalov, Dmitry
2008-01-01
A proposed technique for measuring temperature would exploit differences between the temperature dependences of the frequencies of two different electromagnetic modes of a whispering gallery-mode (WGM) optical resonator. An apparatus based on this technique was originally intended to be part of a control system for stabilizing a laser frequency in the face of temperature fluctuations. When suitably calibrated, apparatuses based on this technique could also serve as precise temperature sensors for purposes other than stabilization of lasers. A sensor according to the proposal would include (1) a transparent WGM dielectric resonator having at least two different sets of modes characterized by different thermo-optical constants and (2) optoelectronic instrumentation for measuring the difference between the temperature-dependent shifts of the resonance frequencies of the two sets of modes.
Resonant quantum transitions in trapped antihydrogen atoms
Amole, C; Baquero-Ruiz, M; Bertsche, W; Bowe, P D; Butler, E; Capra, A; Cesar, C L; Charlton, M; Deller, A; Donnan, P H; Eriksson, S; Fajans, J; Friesen, T; Fujiwara, M C; Gill, D R; Gutierrez, A; Hangst, J S; Hardy, W N; Hayden, M E; Humphries, A J; Isaac, C A; Jonsell, S; Kurchaninov, L; Little, A; Madsen, N; McKenna, J T K; Menary, S; Napoli, S C; Nolan, P; Olchanski, K; Olin, A; Pusa, P; Rasmussen, C Ø; Robicheaux, F; Sarid, E; Shields, C R; Silveira, D M; Stracka, S; So, C; Thompson, R I; van der Werf, D P; Wurtele, J S
2012-01-01
The hydrogen atom is one of the most important and influential model systems in modern physics. Attempts to understand its spectrum are inextricably linked to the early history and development of quantum mechanics. The hydrogen atom’s stature lies in its simplicity and in the accuracy with which its spectrum can be measured1 and compared to theory. Today its spectrum remains a valuable tool for determining the values of fundamental constants and for challenging the limits of modern physics, including the validity of quantum electrodynamics and—by comparison with measurements on its antimatter counterpart, antihydrogen—the validity of CPT (charge conjugation, parity and time reversal) symmetry. Here we report spectroscopy of a pure antimatter atom, demonstrating resonant quantum transitions in antihydrogen. We have manipulated the internal spin state2, 3 of antihydrogen atoms so as to induce magnetic resonance transitions between hyperfine levels of the positronic ground state. We used resonant microwave...
Fabry-Perot resonance of water waves.
Couston, Louis-Alexandre; Guo, Qiuchen; Chamanzar, Maysamreza; Alam, Mohammad-Reza
2015-10-01
We show that significant water wave amplification is obtained in a water resonator consisting of two spatially separated patches of small-amplitude sinusoidal corrugations on an otherwise flat seabed. The corrugations reflect the incident waves according to the so-called Bragg reflection mechanism, and the distance between the two sets controls whether the trapped reflected waves experience constructive or destructive interference within the resonator. The resulting amplification or suppression is enhanced with increasing number of ripples and is most effective for specific resonator lengths and at the Bragg frequency, which is determined by the corrugation period. Our analysis draws on the analogous mechanism that occurs between two partially reflecting mirrors in optics, a phenomenon named after its discoverers Charles Fabry and Alfred Perot.
Nonlinear plasmonic resonances in graphene nanostructures
You, Jian Wei; Weismann, Martin; Panoiu, Nicolae C.
2016-09-01
Peculiar physical properties of graphene offer remarkable potential for advanced photonics, particularly in the area of nonlinear optics at deep-subwavelength scale. In this article, we use a theoretical and computational analysis to demonstrate an efficient mechanism for enhancing the third-harmonic generation in graphene diffraction gratings. By taking advantage of the relation between the resonance wavelength of localized surface-plasmon polaritons of graphene ribbons and disks their specific geometry, we can engineer the spectral response of graphene gratings so as strong plasmonic resonances exist at both the fundamental frequency and third-harmonic (TH). As a result of this dual resonance mechanism for optical near-field enhancement, the intensity of the TH can be increased greatly.
Simplified Limits on New LHC Resonances
Simmons, Elizabeth H; Ittisamai, Pawin; Mohan, Kirtimaan
2016-01-01
If an excess potentially heralding new physics is noticed in collider data, it would be useful to be able to compare the data with entire classes of models at once. This talk discusses a method that applies when the new physics corresponds to the production and decay of a single, relatively narrow, s-channel resonance. A simplifed model of the resonance allows us to convert an estimated signal cross section into model-independent bounds on the product of the branching ratios corresponding to production and decay. This quickly reveals whether a given class of models could possibly produce a signal of the observed size. We will describe how to apply our analysis framework to cases of current experimental interest, including resonances decaying to dibosons, diphotons, dileptons, or dijets.
Double-excited resonant structure of photoionization
Institute of Scientific and Technical Information of China (English)
刘锦超; 杨向东; 王宗笠; 程延松
1997-01-01
The dominant diagrams were found in double-excited resonant structure of photoionization by using many-body perturbation theory.Based on the characteristics of these diagrams,the couple-equation method was improved,and the summation of specific classes of these diagrams is to an infinite order,and the resonant peaks with the widths are obtained first.The doubled-excited resonant structures (2p,3s)→(3p,np),(3p,nf),(3d,nd),(3d,ns) and (4s,ns) of the photoionization processes 2p→ks,kd are obtained.The photoionization with excitation process (2p,3s)→(3p,kp) was included in the calculations.The results of calculations are compared with the experimental data from 38.5 to 46.8 eV photon energies,which are in good agreement with the experiment.
Resonance spectra of diabolo optical antenna arrays
Directory of Open Access Journals (Sweden)
Hong Guo
2015-10-01
Full Text Available A complete set of diabolo optical antenna arrays with different waist widths and periods was fabricated on a sapphire substrate by using a standard e-beam lithography and lift-off process. Fabricated diabolo optical antenna arrays were characterized by measuring the transmittance and reflectance with a microscope-coupled FTIR spectrometer. It was found experimentally that reducing the waist width significantly shifts the resonance to longer wavelength and narrowing the waist of the antennas is more effective than increasing the period of the array for tuning the resonance wavelength. Also it is found that the magnetic field enhancement near the antenna waist is correlated to the shift of the resonance wavelength.
Resonant interactions of perturbations in MHD flows
Energy Technology Data Exchange (ETDEWEB)
Sagalakov, A.M.; Shtern, V.N.
1977-01-17
The nonlinear theory of hydrodynamic stability differentiates three types of interactions: deformation of the initial velocity profile by Reynolds stress pulsations, multiplication of harmonics, and the resonant interaction of harmonics with dissimilar wave numbers and frequencies. This article analyzes an approach considering the first and third of these non-linear mechanisms, producing an acceptable approximation of the averaged characteristics of a developing pulsation movement, particularly the averaged turbulent velocity profile. The approach consists in analysis of triharmonic oscillations, the parameters of which satisfy the resonant relationships. A model of a triharmonic pulsation mode is studied which is applicable to MHD flows. It is shown in particular how a magnetic field transverse to the flow plane suppresses the resonant interaction of three-dimensional perturbations. This agrees with experimental studies on two-dimensional turbulence conducted earlier. 11 references, 3 figures.
Resonance Project; Music from the ATLAS Experiment
Claudia Marcelloni
2010-01-01
The ATLAS Collaboration comprises physicists, engineers, technicians and support staff from 38 countries who have come together at CERN to build and run one of the largest, most complex scientific experiments known to mankind. Drawn together by our common love of science, many of us are also passionate about music. In October 2008, we marked the completion of the ATLAS detector construction with a series of live performances, and thus was born the idea for Resonance. The recording experience was exciting and enjoyable for all of us, many of whom had never entered a studio before. Resonance is a double CD featuring a variety of musical styles from classical to heavy metal. It also includes a DVD with footage of the recording sessions and interviews with some of the musicians. For more information go to www.atlas-resonance.ch
Flavour Covariant Formalism for Resonant Leptogenesis
Dev, P S Bhupal; Pilaftsis, Apostolos; Teresi, Daniele
2014-01-01
We present a fully flavour-covariant formalism for transport phenomena and apply it to study the flavour-dynamics of Resonant Leptogenesis (RL). We show that this formalism provides a complete and unified description of RL, consistently accounting for three distinct physical phenomena: (i) resonant mixing and (ii) coherent oscillations between different heavy-neutrino flavours, as well as (iii) quantum decoherence effects in the charged-lepton sector. We describe the necessary emergence of higher-rank tensors in flavour space, arising from the unitarity cuts of partial self-energies. Finally, we illustrate the importance of this formalism within a minimal Resonant $\\tau$-Genesis model by showing that, with the inclusion of all flavour effects in a consistent way, the final lepton asymmetry can be enhanced by up to an order of magnitude, when compared to previous partially flavour-dependent treatments.
Internal Subharmonic Resonance in Faraday Experiment
Institute of Scientific and Technical Information of China (English)
WANG Xin-Long; CHEN Yi-Huang; WEI Rong-Jue
2000-01-01
The classical Faraday experiment is a tractable problem in nonlinear physics, and its rich spectrum of nonlinear phenomena has made it a prototype in studying nonlinear wave dynamics in general. Here we report the ob servation of a new type of subharmonic resonances which occurs at some smaller fractional frequencies, such as ν/3, ν/4, and ν/6, where ν is the forcing frequency. As a result of these resonances, the lower-order surface-wave modes whose eigenfrequencies are close to the fractional frequencies participate into the wave motions. Our theory involving quadratically nonlinear mode couplings shows that an already excited mode itself can act as a parametric source on the lower-order primary modes, thus leading to the cascading subharmonic resonances.
Mie resonances in inhomogeneous atomic clouds
Bachelard, Romain; Kaiser, Robin; Piovella, Nicola
2011-01-01
Despite the quantum nature of the process, collective scattering by dense cold samples of two-level atoms can be interpreted classically describing the sample as a macroscopic object with a complex refractive index. We demonstrate that Mie resonances can be easily observable in the cooperative scattering by tuning the frequency of the incident laser field or the atomic number. The solution of the scattering problem is obtained for spherical atomic clouds who have the parabolic density characteristic of BECs, and the cooperative radiation pressure force calculated exhibits resonances in the cloud displacement for dense clouds. Reminescent to uniform clouds which show a complex structure of narrow peaks, these densities show resonances, yet under the form of quite regular and contrasted oscillations.
Materials for Bulk Acoustic Resonators and Filters
Loebl, Hans-Peter
2003-03-01
Highly selective solidly mounted bulk acoustic wave (BAW) band pass filters are suited for mobile and wireless systems in the GHz frequency range between 0.8 and 10 GHz. Electro-acoustic thin film BAW resonators are the building blocks these BAW filters. Piezoelectric materials used in these resonators include mainly AlN or ZnO which can be deposited by dedicated thin film sputter deposition techniques. Using these piezo-electric materials and using suited materials for the acoustic Bragg reflector, BAW resonators with high quality factors can be fabricated. The achievable filter bandwidth is approximately 4Alternatively, also ferroelectric thin films might be used to achieve higher coupling coefficient and thus filter bandwidth. BAW resonators and filters have been designed and fabricated on 6" Silicon and glass wafers. Results are presented for resonators and filters operating between 1.95 and 8 GHz. The talk will give an overview of the material aspects which are important for BAW devices. It will be shown that modeling of the resonator and filter response using 1D electro-acoustic simulation (1,2) which includes losses is essential to extract acoustic and electrical material parameters. (1) Solidly Mounted Bulk Acoustic Wave Filters for the Ghz Frequency Range, H.P. Loebl, C. Metzmacher , D.N.Peligrad , R. Mauczok , M. Klee , W. Brand , R.F. Milsom , P.Lok , F.van Straten , A. Tuinhout , J.W.Lobeek, IEEE 2002 Ultrasonics Symposium Munich, October 2002. (2) Combined Acoustic-Electromagnetic Simulation Of Thin-Film Bulk Acoustic Wave Filters, R.F. Milsom, H-P. Löbl, D.N. Peligrad, J-W. Lobeek, A. Tuinhout, R. H. ten Dolle IEEE 2002 Ultrasonics Symposium Munich, October 2002.
Resonant tunneling in graphene pseudomagnetic quantum dots.
Qi, Zenan; Bahamon, D A; Pereira, Vitor M; Park, Harold S; Campbell, D K; Neto, A H Castro
2013-06-12
Realistic relaxed configurations of triaxially strained graphene quantum dots are obtained from unbiased atomistic mechanical simulations. The local electronic structure and quantum transport characteristics of y-junctions based on such dots are studied, revealing that the quasi-uniform pseudomagnetic field induced by strain restricts transport to Landau level- and edge state-assisted resonant tunneling. Valley degeneracy is broken in the presence of an external field, allowing the selective filtering of the valley and chirality of the states assisting in the resonant tunneling. Asymmetric strain conditions can be explored to select the exit channel of the y-junction.
Highlights of Resonance Measurements With HADES
Directory of Open Access Journals (Sweden)
Epple Eliane
2015-01-01
Full Text Available This contribution aims to give a basic overview of the latest results regarding the production of resonances in different collision systems. The results were extracted from experimental data collected with HADES that is a multipurpose detector located at the GSI Helmholtzzentrum, Darmstadt. The main points discussed here are: the properties of the strange resonances Λ(1405 and Σ(1385, the role of Δ’s as a source of pions in the final state, the production dynamics reflected in form of differential cross sections, and the role of the ϕ meson as a source for K− particles.
Hollow Core, Whispering Gallery Resonator Sensors
Ward, Jonathan M; Chormaic, Síle Nic
2014-01-01
A review of hollow core whispering gallery resonators (WGRs)is given. After a short introduction to the topic of whispering gallery resonators we provide a description of whispering gallery modes in hollow or liquid core WGRs. Next, whispering gallery mode (WGM) sensing mechanisms are outlined and some fabrication methods for microbubbles, microcapillaries and other tubular WGM devices are discussed. We then focus on the most common applications of hollow core WGRs, namely refractive index and temperature sensing, gas sensing, force sensing, biosensing, and lasing. The review highlights some of the key papers in this field and gives the reader a general overview of the current state-of-the-art.
Electron paramagnetic resonance of transition ions
Abragam, A
2012-01-01
This book is a reissue of a classic Oxford text, and provides a comprehensive treatment of electron paramagnetic resonance of ions of the transition groups. The emphasis is on basic principles, with numerous references to publications containing further experimental results and more detailed developments of the theory. An introductory survey gives a general understanding, and a general survey presents such topics as the classical and quantum resonance equations, thespin-Hamiltonian, Endor, spin-spin and spin-lattice interactions, together with an outline of the known behaviour of ions of each
Extraordinary transmission in optical Helmholtz resonators.
Chevalier, Paul; Bouchon, Patrick; Sakat, Emilie; Pelouard, Jean-Luc; Pardo, Fabrice; Haïdar, Riad
2015-06-15
Optical Helmholtz resonators (OHRs) have been adapted from acoustics designs for light absorbing structures, exhibiting extreme light confinement. Here, extraordinary transmission of light is theoretically demonstrated through symmetric OHRs, comprising a cavity with two λ/500 narrow slits on either side. This device has appealing features to act as a spectral bandpass filter in the context of multispectral imaging, in particular its high angular tolerance because of the localized nature of the resonance. Besides, the cavity can be modeled as an inductor and the two slits can be modeled as capacitors, the whole design acting as a LC circuit thus preventing any harmonic features.
Holonomy invariance, orbital resonances, and kilohertz QPOs
Abramowicz, M A; Kluzniak, W; Thampan, A V; Wallinder, F
2002-01-01
Quantized orbital structures are typical for many aspects of classical gravity (Newton's as well as Einstein's). The astronomical phenomenon of orbital resonances is a well-known example. Recently, Rothman, Ellis and Murugan (2001) discussed quantized orbital structures in the novel context of a holonomy invariance of parallel transport in Schwarzschild geometry. We present here yet another example of quantization of orbits, reflecting both orbital resonances and holonomy invariance. This strong-gravity effect may already have been directly observed as the puzzling kilohertz quasi-periodic oscillations (QPOs) in the X-ray emission from a few accreting galactic black holes and several neutron stars.
Induced transparency in optomechanically coupled resonators
Duan, Zhenglu; Stace, Thomas M; Milburn, G J; Holmes, Catherine A
2015-01-01
In this work we theoretically investigate a hybrid system of two optomechanically coupled resonators, which exhibits induced transparency. This is realized by coupling an optical ring resonator to a toroid. In the semiclassical analyses, the system displays bistabilities, isolated branches (isolas) and self-sustained oscillation dynamics. Furthermore, we find that the induced transparency transparency window sensitively relies on the mechanical motion. Based on this fact, we show that the described system can be used as a weak force detector and the optimal sensitivity can beat the standard quantum limit without using feedback control or squeezing under available experimental conditions.