WorldWideScience

Sample records for c-1430 resonances

  1. Resonance

    DEFF Research Database (Denmark)

    Petersen, Nils Holger

    2014-01-01

    A chapter in a book about terminology within the field of medievalism: the chapter discusses the resonance of medieval music and ritual in modern (classical) music culture and liturgical practice.......A chapter in a book about terminology within the field of medievalism: the chapter discusses the resonance of medieval music and ritual in modern (classical) music culture and liturgical practice....

  2. Resonances

    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...... of the book: how connotations of past meanings may resonate through time, in new contexts, assuming new meanings without surrendering the old....

  3. RESONANCE

    Indian Academy of Sciences (India)

    Nuclear magnetic resonance (NMR) is a mani- festation of an intrinsic property of the nucleus, i.e. nuclear spin angular momen- tum. Spin angular momentum gives rise to magnetic moments. Thus, nuclei that pos- sess net magnetic moments behave like very small bar magnets. NMR spectroscopy in- volves the study of the ...

  4. 849 RESONANCE | September 2013

    Indian Academy of Sciences (India)

    IAS Admin

    849. RESONANCE | September 2013. Page 2. 850. RESONANCE | September 2013. Page 3. 851. RESONANCE | September 2013. Page 4. 852. RESONANCE | September 2013. Page 5. 853. RESONANCE | September 2013. Page 6. 854. RESONANCE | September 2013. Page 7. 855. RESONANCE | September 2013.

  5. Photothermal resonance

    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...

  6. Nonlinear resonances

    CERN Document Server

    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...

  7. Neuroaesthetic Resonance

    DEFF Research Database (Denmark)

    Brooks, Anthony Lewis

    2013-01-01

    Neuroaesthetic Resonance emerged from a mature body of patient- centered gesture-control research investigating non-formal rehabilitation via ICT-enhanced-Art to question ‘Aesthetic Resonance’. Motivating participation, ludic engagement, and augmenting physical motion in non-formal (fun) treatment...... 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....

  8. Multiquark Resonances

    CERN Document Server

    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.

  9. 996 RESONANCE November 2013

    Indian Academy of Sciences (India)

    IAS Admin

    996. RESONANCE. November 2013. Page 2. 997. RESONANCE. November 2013. Page 3. 998. RESONANCE. November 2013. Page 4. 999. RESONANCE. November 2013. Page 5. 1000. RESONANCE. November 2013. Page 6. 1001. RESONANCE. November 2013. Page 7. 1002. RESONANCE. November 2013 ...

  10. 817 RESONANCE September 2013

    Indian Academy of Sciences (India)

    IAS Admin

    817. RESONANCE ⎜ September 2013. Page 2. 818. RESONANCE ⎜ September 2013. Page 3. 819. RESONANCE ⎜ September 2013. Page 4. 820. RESONANCE ⎜ September 2013. Page 5. 821. RESONANCE ⎜ September 2013. Page 6. 822. RESONANCE ⎜ September 2013. Page 7. 823. RESONANCE ⎜ September ...

  11. 369 RESONANCE April 2016

    Indian Academy of Sciences (India)

    IAS Admin

    369. RESONANCE ⎜ April 2016. Page 2. 370. RESONANCE ⎜ April 2016. Page 3. 371. RESONANCE ⎜ April 2016. Page 4. 372. RESONANCE ⎜ April 2016. Page 5. 373. RESONANCE ⎜ April 2016. Page 6. 374. RESONANCE ⎜ April 2016. Page 7. 375. RESONANCE ⎜ April 2016.

  12. Autostereogram resonators

    Science.gov (United States)

    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.

  13. Resonant behavior of dielectric objects (electrostatic resonances).

    Science.gov (United States)

    Fredkin, D R; Mayergoyz, I D

    2003-12-19

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

  14. Neuroaesthetic Resonance

    OpenAIRE

    Brooks, Anthony Lewis

    2013-01-01

    Neuroaesthetic Resonance emerged from a mature body of patient- centered gesture-control research investigating non-formal rehabilitation via ICT-enhanced-Art to question ‘Aesthetic Resonance’. Motivating participation, ludic engagement, and augmenting physical motion in non-formal (fun) treatment 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 stimu...

  15. Magnetic Resonance (MR) Defecography

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Magnetic Resonance (MR) Defecography Magnetic resonance (MR) defecography is a ... the limitations of MRI defecography? What is magnetic resonance (MR) defecography? Magnetic resonance imaging (MRI) is a ...

  16. 1004 RESONANCE November 2013

    Indian Academy of Sciences (India)

    IAS Admin

    1004. RESONANCE │ November 2013. Page 2. 1005. RESONANCE │ November 2013. Page 3. 1006. RESONANCE │ November 2013. Page 4. 1007. RESONANCE │ November 2013. Page 5. 1008. RESONANCE │ November 2013. Page 6. 1009. RESONANCE │ November 2013. Page 7. 1010. RESONANCE ...

  17. MRI (Magnetic Resonance Imaging)

    Science.gov (United States)

    ... 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) ...

  18. Magnetic Resonance Imaging

    Science.gov (United States)

    ... specific information about your own examination. What is magnetic resonance imaging (MRI)? What is MRI used for? How safe ... What is the MRI examination like? What is magnetic resonance imaging (MRI)? MRI, or magnetic resonance imaging, is a ...

  19. Regenerative feedback resonant circuit

    Science.gov (United States)

    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.

  20. Integral resonator gyroscope

    Science.gov (United States)

    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.

  1. Partially orthogonal resonators for magnetic resonance imaging

    Science.gov (United States)

    Chacon-Caldera, Jorge; Malzacher, Matthias; Schad, Lothar R.

    2017-02-01

    Resonators for signal reception in magnetic resonance are traditionally planar to restrict coil material and avoid coil losses. Here, we present a novel concept to model resonators partially in a plane with maximum sensitivity to the magnetic resonance signal and partially in an orthogonal plane with reduced signal sensitivity. Thus, properties of individual elements in coil arrays can be modified to optimize physical planar space and increase the sensitivity of the overall array. A particular case of the concept is implemented to decrease H-field destructive interferences in planar concentric in-phase arrays. An increase in signal to noise ratio of approximately 20% was achieved with two resonators placed over approximately the same planar area compared to common approaches at a target depth of 10 cm at 3 Tesla. Improved parallel imaging performance of this configuration is also demonstrated. The concept can be further used to increase coil density.

  2. Crossing a Nonlinear Resonance

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 9. Crossing a Nonlinear Resonance: Adiabatic Invariants and the Melnikov-Arnold Integral. Sudhir R Jain. General Article Volume 19 Issue 9 September 2014 pp 797-813 ...

  3. Nanomechanical resonance detector

    Science.gov (United States)

    Grossman, Jeffrey C; Zettl, Alexander K

    2013-10-29

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

  4. Magnetic resonance angiography

    Science.gov (United States)

    MRA; Angiography - magnetic resonance ... Kwong RY. Cardiovascular magnetic resonance imaging. In: Bonow RO, Mann DL, Zipes DP, Libby P, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular ...

  5. Ovenized microelectromechanical system (MEMS) resonator

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. 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 the system undergoing it could transform the large amplitude motion into, for example, energy. Therefore the development of control strategies to induce parametric resonance into a system can be as valuable as those which aim at stabilizing the resonant oscillations. By means of a mechanical equivalent...... the authors review the conditions for the onset of parametric resonance, and propose a nonlinear control strategy in order to both induce the resonant oscillations and to stabilize the unstable motion. Lagrange’s theory is used to derive the dynamics of the system and input–output feedback linearization...

  7. Atlas of neutron resonances

    CERN Document Server

    Mughabghab, Said

    2018-01-01

    Atlas of Neutron Resonances: Resonance Properties and Thermal Cross Sections Z= 1-60, Sixth Edition, contains an extensive list of detailed individual neutron resonance parameters for Z=1-60, as well as thermal cross sections, capture resonance integrals, average resonance parameters and a short survey of the physics of thermal and resonance neutrons. The long introduction contains: nuclear physics formulas aimed at neutron physicists; topics of special interest such as valence neutron capture, nuclear level density parameters, and s-, p-, and d-wave neutron strength functions; and various comparisons of measured quantities with the predictions of nuclear models, such as the optical model. As in the last edition, additional features have been added to appeal to a wider spectrum of users. These include: spin-dependent scattering lengths that are of interest to solid-state physicists, nuclear physicists and neutron evaluators; calculated and measured Maxwellian average 5-keV and 30-keV capture cross sections o...

  8. Electron paramagnetic resonance

    CERN Document Server

    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

  9. Logical Stochastic Resonance

    Indian Academy of Sciences (India)

    andoh

    input signals, consisting of random square waves. We find that, in an optimal band of noise, the output consistently is a logical combination of the input signals: Logical Stochastic Resonance. (LSR) with K. Murali, W.L. Ditto, A. Bulsara. Physical Review Letters, March 2009. Sudeshna Sinha. Logical Stochastic Resonance ...

  10. A New Resonance Tube

    Science.gov (United States)

    Bates, Alan

    2017-01-01

    The measurement of the speed of sound in air with the resonance tube is a popular experiment that often yields accurate results. One approach is to hold a vibrating tuning fork over an air column that is partially immersed in water. The column is raised and lowered in the water until the generated standing wave produces resonance: this occurs at…

  11. Resonance and Fractal Geometry

    NARCIS (Netherlands)

    Broer, Henk W.

    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

  12. Electron Paramagnetic Resonance Spectroscopy

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 11. Electron Paramagnetic Resonance Spectroscopy: Biological Applications. B G Hegde. General Article Volume 20 Issue 11 November 2015 pp 1017-1032. Fulltext. Click here to view fulltext PDF. Permanent link:

  13. Nuclear Magnetic Resonance Spectroscopy

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 1. Nuclear Magnetic Resonance Spectroscopy. Susanta Das. General Article Volume 9 Issue 1 January 2004 pp 34-49. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/009/01/0034-0049. Keywords.

  14. Resonant snubber inverter

    Science.gov (United States)

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

    1997-06-24

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

  15. Writing with resonance

    DEFF Research Database (Denmark)

    Meier, Ninna; Wegener, Charlotte

    2017-01-01

    In this article, we explore what organization and management scholars can do to write with resonance and to facilitate an emotional, bodily, or in other ways sensory connection between the text and the reader. We propose that resonance can be relevant for organization and management scholars in t......, and thus bring forward the field of research in question. We propose that writing with resonance may be a way to further the impact of academic work by extending the modalities with which our readers can relate to and experience our work.......In this article, we explore what organization and management scholars can do to write with resonance and to facilitate an emotional, bodily, or in other ways sensory connection between the text and the reader. We propose that resonance can be relevant for organization and management scholars in two...

  16. Fundamentals of nanomechanical resonators

    CERN Document Server

    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...

  17. Enhanced quadruple-resonant terahertz metamaterial with asymmetric hybrid resonators

    Science.gov (United States)

    Shi, Minglei; Lan, Feng; Mazumder, Pinaki; Aghadjani, Mahdi; Yang, Ziqiang; Meng, Lin; Zhou, Jun

    2018-01-01

    This paper presents the design, fabrication and investigation of a quadruple-resonant terahertz metamaterial that comprises two different Electric-inductance capacitance (ELC) resonators in a vertical configuration. Owing to asymmetric electric field coupling between the two resonators, the combined structure exhibits better performance in terms of transmission minima and bandwidths than the individual particles. The distributions of the surface current and electric field reveal quasi-quadrupole resonance, electric dipolar resonance and coupling between these resonances at different resonant frequencies. Moreover, the resonant frequencies are tunable by adjusting the corresponding geometrical parameters. Above all, the excellent performance of the proposed structure makes it promising for application in multiband terahertz devices.

  18. Magnetic Resonance Imaging (MRI) -- Head

    Science.gov (United States)

    ... 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 ...

  19. Magnetic Resonance Imaging (MRI) - Spine

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Spine Magnetic resonance imaging (MRI) of the spine ... limitations of MRI of the Spine? What is MRI of the Spine? Magnetic resonance imaging (MRI) is ...

  20. Resonant detectors for gravitational waves

    Energy Technology Data Exchange (ETDEWEB)

    Pizzella, G. [Rome Univ. `Tor Vergata` (Italy). Dip. di Fisica]|[Istituto di Fisica Nucleare, Frascati, Rome (Italy)

    1995-11-01

    The principles of the gravitational wave detection by means of resonant antennas are illustrated and a review of the resonant antenna experiments in the world is given. Possible plans for the future resonant antennas are indicated.

  1. LABCOM resonator Phase 3

    Energy Technology Data Exchange (ETDEWEB)

    Keres, L.J.

    1990-11-01

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

  2. Magnetic Resonance Force Microscopy System

    Data.gov (United States)

    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,...

  3. Resonant halide perovskite nanoparticles

    Science.gov (United States)

    Tiguntseva, Ekaterina Y.; Ishteev, Arthur R.; Komissarenko, Filipp E.; Zuev, Dmitry A.; Ushakova, Elena V.; Milichko, Valentin A.; Nesterov-Mueller, Alexander; Makarov, Sergey V.; Zakhidov, Anvar A.

    2017-09-01

    The hybrid halide perovskites is a prospective material for fabrication of cost-effective optical devices. Unique perovskites properties are used for solar cells and different photonic applications. Recently, perovskite-based nanophotonics has emerged. Here, we consider perovskite like a high-refractive index dielectric material, which can be considered to be a basis for nanoparticles fabrication with Mie resonances. As a result, we fabricate and study resonant perovskite nanoparticles with different sizes. We reveal, that spherical nanoparticles show enhanced photoluminescence signal. The achieved results lay a cornerstone in the field of novel types of organic-inorganic nanophotonics devices with optical properties improved by Mie resonances.

  4. Tunable multiwalled nanotube resonator

    Science.gov (United States)

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

    2013-11-05

    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.

  5. Resonant power converters

    CERN Document Server

    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

  6. Magnetic Resonance Sensors

    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.[...

  7. Resonant Thermoelectric Nanophotonics

    CERN Document Server

    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...

  8. Piezoelectric MEMS resonators

    CERN Document Server

    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...

  9. Ghost magnetic resonance angiography

    National Research Council Canada - National Science Library

    Koktzoglou, Ioannis; Edelman, Robert R

    2009-01-01

    Traditional methods for magnetic resonance angiography (MRA) involve the radiofrequency excitation of vascular spins within a selected region of tissue, followed by gradient localization and imaging of those spins within that same region...

  10. Triple-resonant transducers.

    Science.gov (United States)

    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.

  11. Resonant diphoton phenomenology simplified

    Energy Technology Data Exchange (ETDEWEB)

    Panico, Giuliano [IFAE, Universitat Autònoma de Barcelona,E-08193 Bellaterra, Barcelona (Spain); Vecchi, Luca [SISSA,via Bonomea 265, 34136, Trieste (Italy); Dipartimento di Fisica e Astronomia, Università di Padova and INFN - Sezione di Padova,via Marzolo 8, I-35131 Padova (Italy); Wulzer, Andrea [Dipartimento di Fisica e Astronomia, Università di Padova and INFN - Sezione di Padova,via Marzolo 8, I-35131 Padova (Italy)

    2016-06-30

    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 resonant diphoton production.

  12. Lattices of dielectric resonators

    CERN Document Server

    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...

  13. Resonances in QCD

    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.

  14. Magnetic Resonance Sensors

    OpenAIRE

    Morris, RH; Newton, MI

    2014-01-01

    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 medica...

  15. Resonant dielectric metamaterials

    Science.gov (United States)

    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.

  16. Hexagonal quartz resonator

    Science.gov (United States)

    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.

  17. 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.).

  18. Overview of baryon resonances

    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.

  19. Electrothermally Tunable Arch Resonator

    KAUST Repository

    Hajjaj, Amal Z.

    2017-03-18

    This paper demonstrates experimentally, theoretically, and numerically a wide-range tunability of electrothermally actuated microelectromechanical arch beams. The beams are made of silicon and are intentionally fabricated with some curvature as in-plane shallow arches. An electrothermal voltage is applied between the anchors of the beam generating a current that controls the axial stress caused by thermal expansion. When the electrothermal voltage increases, the compressive stress increases inside the arch beam. This leads to an increase in its curvature, thereby increasing its resonance frequencies. We show here that the first resonance frequency can increase monotonically up to twice its initial value. We show also that after some electrothermal voltage load, the third resonance frequency starts to become more sensitive to the axial thermal stress, while the first resonance frequency becomes less sensitive. These results can be used as guidelines to utilize arches as wide-range tunable resonators. Analytical results based on the nonlinear Euler Bernoulli beam theory are generated and compared with the experimental data and the results of a multi-physics finite-element model. A good agreement is found among all the results. [2016-0291

  20. Electrothermally Tunable Bridge Resonator

    KAUST Repository

    Hajjaj, Amal Z.

    2016-12-05

    This paper demonstrates experimentally, theoretically, and numerically a wide-range tunability of an in-plane clamped-clamped microbeam, bridge, and resonator compressed by a force due to electrothermal actuation. We demonstrate that a single resonator can be operated at a wide range of frequencies. The microbeam is actuated electrothermally, by passing a DC current through it. We show that when increasing the electrothermal voltage, the compressive stress inside the microbeam increases, which leads eventually to its buckling. Before buckling, the fundamental frequency decreases until it drops to very low values, almost to zero. After buckling, the fundamental frequency increases, which is shown to be as high as twice the original resonance frequency. Analytical results based on the Galerkin discretization of the Euler Bernoulli beam theory are generated and compared to the experimental data and to simulation results of a multi-physics finite-element model. A good agreement is found among all the results.

  1. Quartz resonator processing system

    Science.gov (United States)

    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.

  2. Pygmy Dipole Resonances

    Science.gov (United States)

    Krewald, S.; Speth, J.

    Electric dipole strength below the particle emission threshold both in stable nuclei and short-lived isotopes has received increasing interest due to its astrophysical impact. In analogy to the giant dipole resonance, this strength is commonly referred to as pygmy resonance. Coulomb dissociation of neutron-rich unstable isotopes and nuclear resonance fluorescence photon scattering have begun to provide systematic data on electric dipole strength in various isotope chains. We review the present state of the art of theoretical approaches and point out some open problems. We emphasize the necessity of a simultaneous theoretical treatment of the nucleon separation energies and the energetically low-lying dipole strength because the presently available data do not exclude a non-collective nature of the pygmy strength.

  3. Reconfigurable optical routers based on Coupled Resonator Induced Transparency resonances.

    Science.gov (United States)

    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.

  4. Higgs-photon resonances

    Energy Technology Data Exchange (ETDEWEB)

    Dobrescu, Bogdan A.; Fox, Patrick J.; Kearney, John [Fermilab, Theoretical Physics Department, Batavia, IL (United States)

    2017-10-15

    We study models that produce a Higgs boson plus photon (h{sup 0}γ) resonance at the LHC. When the resonance is a Z{sup '} boson, decays to h{sup 0}γ occur at one loop. If the Z{sup '} boson couples at tree level to quarks, then the h{sup 0}γ branching fraction is typically of order 10{sup -5} or smaller. Nevertheless, there are models that would allow the observation of Z{sup '} → h{sup 0}γ at √(s) = 13 TeV with a cross section times branching fraction larger than 1 fb for a Z{sup '} mass in the 200-450 GeV range, and larger than 0.1 fb for a mass up to 800 GeV. The one-loop decay of the Z{sup '} into lepton pairs competes with h{sup 0}γ, even if the Z{sup '} couplings to leptons vanish at tree level. We also present a model in which a Z{sup '} boson decays into a Higgs boson and a pair of collimated photons, mimicking an h{sup 0}γ resonance. In this model, the h{sup 0}γ resonance search would be the discovery mode for a Z{sup '} as heavy as 2 TeV. When the resonance is a scalar, although decay to h{sup 0}γ is forbidden by angular momentum conservation, the h{sup 0} plus collimated photons channel is allowed. We comment on prospects of observing an h{sup 0}γ resonance through different Higgs decays, on constraints from related searches, and on models where h{sup 0} is replaced by a nonstandard Higgs boson. (orig.)

  5. Higgs-photon resonances

    Energy Technology Data Exchange (ETDEWEB)

    Dobrescu, Bogdan A. [Fermilab; Fox, Patrick J. [Fermilab; Kearney, John [Fermilab

    2017-05-23

    We study models that produce a Higgs boson plus photon ($h^0 \\gamma$) resonance at the LHC. When the resonance is a $Z'$ boson, decays to $h^0 \\gamma$ occur at one loop. If the $Z'$ boson couples at tree-level to quarks, then the $h^0 \\gamma$ branching fraction is typically of order $10^{-5}$ or smaller. Nevertheless, there are models that would allow the observation of $Z' \\to h^0 \\gamma$ at $\\sqrt{s} = 13$ TeV with a cross section times branching fraction larger than 1 fb for a $Z'$ mass in the 200--450 GeV range, and larger than 0.1 fb for a mass up to 800 GeV. The 1-loop decay of the $Z'$ into lepton pairs competes with $h^0 \\gamma$, even if the $Z'$ couplings to leptons vanish at tree level. We also present a model in which a $Z'$ boson decays into a Higgs boson and a pair of collimated photons, mimicking an $h^0 \\gamma$ resonance. In this model, the $h^0 \\gamma$ resonance search would be the discovery mode for a $Z'$ as heavy as 2 TeV. When the resonance is a scalar, although decay to $h^0 \\gamma$ is forbidden by angular momentum conservation, the $h^0$ plus collimated photons channel is allowed. We comment on prospects of observing an $h^0 \\gamma$ resonance through different Higgs decays, on constraints from related searches, and on models where $h^0$ is replaced by a nonstandard Higgs boson.

  6. Nanoantenna using mechanical resonance

    KAUST Repository

    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.

  7. Hadronic Resonances from STAR

    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.

  8. Acoustic Fano resonators

    KAUST Repository

    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).

  9. Electron Paramagnetic Resonance Imaging

    Indian Academy of Sciences (India)

    IAS Admin

    Resonance Imaging (MRI). Unlike MRI which addresses the naturally occurring abundant water protons in vivo, EPRI re- quires the administration of non-toxic paramagnetic free radicals into the living system prior to monitoring their distribution. The principle behind imaging is to generate profiles of EPR spectra in presence ...

  10. Nuclear Magnetic Resonance

    Indian Academy of Sciences (India)

    IAS Admin

    This article summarizes the early history of nuclear magnetic resonance (NMR) during the first 25–30 years. The method- ology went through vigorous growth and development during this time, laying the theoretical basis for understanding a wide array of applications. The stage was set for the breath- taking advances the ...

  11. Functional Magnetic Resonance Imaging

    Science.gov (United States)

    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…

  12. 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)

  13. Editorial -RE-SONANCE

    Indian Academy of Sciences (India)

    having seen the initial issues of Resonance. They have also made several valuable suggestions for improvements. We are grateful for the former, and ... back cover), in a burst of enthusiasm we described his principle of least time in optics as the earliest example of a minimum principle in physics. This was a fortunate error, ...

  14. r-es-onance

    Indian Academy of Sciences (India)

    molecules, D-D, N-D, D-N and N-N and one fourth of the total molecules will be functional. That is, out of 3000, only 750 will be functional. Whose statement do you think is correct? The biochemist's or the mathematician's? And why?,. 2. Organic Readion Mechanisms. In the February 1997 issue of Resonance, two multi-step.

  15. Electrically detected ferromagnetic resonance

    NARCIS (Netherlands)

    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 ? and the Hall voltage VHall characteristically change when a ferromagnetic resonance (FMR) occurs in the film. The electrically detected ferromagnetic

  16. Resonant MEMS tunable VCSEL

    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...

  17. 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...

  18. Electron Paramagnetic Resonance Spectroscopy

    Indian Academy of Sciences (India)

    IAS Admin

    Recently, electron paramagnetic resonance (EPR) spectros- copy has emerged as a powerful tool to study the structure and dynamics of biological macromolecules such as proteins, protein aggregates, RNA and DNA. It is used in combination with molecular modelling to study complex systems such as soluble proteins ...

  19. Electron Paramagnetic Resonance Imaging

    Indian Academy of Sciences (India)

    IAS Admin

    Electron Paramagnetic Resonance Imaging. 2. Radiofrequency FT-EPR Imaging. Sankaran Subramanian and Murali C Krishna. Keywords. FT-EPR, Hahn-echo, acquisition delay, single-point imaging (SPI), gradient-echo, k-space, echo-SPI, carbogen, oxygen relaxivity, T2*. T2- and T1-based oximetry, co- registration ...

  20. Electron Paramagnetic Resonance Imaging

    Indian Academy of Sciences (India)

    Twentieth century bore witness to remarkable scientists whohave advanced our understanding of the brain. Among them,EPR (Electron Paramagnetic Resonance) imaging is particularlyuseful in monitoring hypoxic zones in tumors which arehighly resistant to radiation and chemotherapeutic treatment.This first part of the ...

  1. Resonant photothermal IR spectroscopy of picogram samples with microstring resonator

    DEFF Research Database (Denmark)

    Yamada, Shoko; Schmid, Silvan; Boisen, Anja

    2013-01-01

    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...

  2. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) uses a powerful magnetic field, radio waves ...

  3. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... information on the chemicals present in the body's cells, may also be performed during the MRI exam ... and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic Resonance Imaging ( ...

  4. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a powerful magnetic field, radio waves and a computer to produce ...

  5. Magnetic Resonance Imaging (MRI) Safety

    Science.gov (United States)

    ... 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, ...

  6. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) uses a powerful magnetic field, radio ...

  7. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... 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 ...

  8. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... the same effect. A very irregular heartbeat may affect the quality of images obtained using techniques that ... and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic Resonance Imaging ( ...

  9. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... 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 ...

  10. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... data suggest that it is safe to continue breastfeeding after receiving intravenous contrast. For further information please ... Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic Resonance Imaging ( ...

  11. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... for Brain Tumors Radiation Therapy for Head and Neck Cancer Others : American Stroke Association National Stroke Association ... MRA) Magnetic Resonance, Functional (fMRI) - Brain Head and Neck Cancer Treatment Brain Tumor Treatment Magnetic Resonance Imaging ( ...

  12. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... techniques that time the imaging based on the electrical activity of the heart, such as electrocardiography (ECG). ... Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic Resonance Imaging (MRI) Safety Contrast Materials Children ...

  13. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... may sense a temporary metallic taste in their mouth after the contrast injection. If you do not ... Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic Resonance Imaging ( ...

  14. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    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 ...

  15. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    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 ...

  16. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging ( ... the limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a ...

  17. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a powerful ... Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive medical test that ...

  18. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) ... limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a noninvasive ...

  19. Molecular Cardiovascular Magnetic Resonance

    DEFF Research Database (Denmark)

    Bender, Yvonne Y; Pfeifer, Andreas; Ebersberger, Hans U

    2016-01-01

    In the Western world and developing countries, the number one causes of mortality and morbidity result from cardiovascular diseases. Cardiovascular diseases represent a wide range of pathologies, including myocardial infarction, peripheral vascular disease, and cerebrovascular disease, which...... impact on society, there are still limitations in the early diagnosis and the prevention of the disease. Current imaging methods mainly focus on morphological changes that occur at an advanced disease stage, e.g., degree of stenosis. Cardiovascular magnetic resonance imaging and specifically molecular...... cardiovascular magnetic resonance imaging are capable to reveal pathophysiological changes already occurring during early atherosclerotic plaque formation. This allows for the assessment of cardiovascular disease on a level, which goes beyond morphological or anatomical criteria. In this review, we...

  20. Nanowire resonant tunneling diodes

    Science.gov (United States)

    Björk, M. T.; Ohlsson, B. J.; Thelander, C.; Persson, A. I.; Deppert, K.; Wallenberg, L. R.; Samuelson, L.

    2002-12-01

    Semiconductor heterostructures and their implementation into electronic and photonic devices have had tremendous impact on science and technology. In the development of quantum nanoelectronics, one-dimensional (1D) heterostructure devices are receiving a lot of interest. We report here functional 1D resonant tunneling diodes obtained via bottom-up assembly of designed segments of different semiconductor materials in III/V nanowires. The emitter, collector, and the central quantum dot are made from InAs and the barrier material from InP. Ideal resonant tunneling behavior, with peak-to-valley ratios of up to 50:1 and current densities of 1 nA/μm2 was observed at low temperatures.

  1. Ultraminiature resonator accelerometer

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-04-01

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

  2. Resonant state expansions

    Energy Technology Data Exchange (ETDEWEB)

    Lind, P.

    1993-02-01

    The completeness properties of the discrete set of bound state, virtual states and resonances characterizing the system of a single nonrelativistic particle moving in a central cutoff potential is investigated. From a completeness relation in terms of these discrete states and complex scattering states one can derive several Resonant State Expansions (RSE). It is interesting to obtain purely discrete expansion which, if valid, would significantly simplify the treatment of the continuum. Such expansions can be derived using Mittag-Leffler (ML) theory for a cutoff potential and it would be nice to see if one can obtain the same expansions starting from an eigenfunction theory that is not restricted to a finite sphere. The RSE of Greens functions is especially important, e.g. in the continuum RPA (CRPA) method of treating giant resonances in nuclear physics. The convergence of RSE is studied in simple cases using square well wavefunctions in order to achieve high numerical accuracy. Several expansions can be derived from each other by using the theory of analytic functions and one can the see how to obtain a natural discretization of the continuum. Since the resonance wavefunctions are oscillating with an exponentially increasing amplitude, and therefore have to be interpreted through some regularization procedure, every statement made about quantities involving such states is checked by numerical calculations.Realistic nuclear wavefunctions, generated by a Wood-Saxon potential, are used to test also the usefulness of RSE in a realistic nuclear calculation. There are some fundamental differences between different symmetries of the integral contour that defines the continuum in RSE. One kind of symmetry is necessary to have an expansion of the unity operator that is idempotent. Another symmetry must be used if we want purely discrete expansions. These are found to be of the same form as given by ML. (29 refs.).

  3. Off-resonance NOVEL

    Science.gov (United States)

    Jain, Sheetal K.; Mathies, Guinevere; Griffin, Robert G.

    2017-10-01

    Dynamic nuclear polarization (DNP) is theoretically able to enhance the signal in nuclear magnetic resonance (NMR) experiments by a factor γe/γn, where γ 's are the gyromagnetic ratios of an electron and a nuclear spin. However, DNP enhancements currently achieved in high-field, high-resolution biomolecular magic-angle spinning NMR are well below this limit because the continuous-wave DNP mechanisms employed in these experiments scale as ω0-n where n ˜ 1-2. In pulsed DNP methods, such as nuclear orientation via electron spin-locking (NOVEL), the DNP efficiency is independent of the strength of the main magnetic field. Hence, these methods represent a viable alternative approach for enhancing nuclear signals. At 0.35 T, the NOVEL scheme was demonstrated to be efficient in samples doped with stable radicals, generating 1H NMR enhancements of ˜430. However, an impediment in the implementation of NOVEL at high fields is the requirement of sufficient microwave power to fulfill the on-resonance matching condition, ω0I = ω1S, where ω0I and ω1S are the nuclear Larmor and electron Rabi frequencies, respectively. Here, we exploit a generalized matching condition, which states that the effective Rabi frequency, ω1S e f f, matches ω0I. By using this generalized off-resonance matching condition, we generate 1H NMR signal enhancement factors of 266 (˜70% of the on-resonance NOVEL enhancement) with ω1S/2π = 5 MHz. We investigate experimentally the conditions for optimal transfer of polarization from electrons to 1H both for the NOVEL mechanism and the solid-effect mechanism and provide a unified theoretical description for these two historically distinct forms of DNP.

  4. Tandem resonator reflectance modulator

    Science.gov (United States)

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

    1994-09-06

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

  5. Magnetic Resonance Safety

    OpenAIRE

    Sammet, Steffen

    2016-01-01

    Magnetic Resonance Imaging (MRI) has a superior soft-tissue contrast compared to other radiological imaging modalities and its physiological and functional applications have led to a significant increase in MRI scans worldwide. A comprehensive MRI safety training to protect patients and other healthcare workers from potential bio-effects and risks of the magnetic fields in an MRI suite is therefore essential. The knowledge of the purpose of safety zones in an MRI suite as well as MRI appropri...

  6. Optical resonator theory

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jaeg Won; Cho, Sunh Oh; Jeong, Young Uk; Lee, Byung Cheol; Lee, Jong Min

    2000-10-01

    In this report we present a theoretical study of bare optical resonators having in mind to extend it to active resonators. To compute diffractional losses, phase shifts, intensity distributions and phases of radiation fields on mirrors, we coded a package of numerical procedures on bases of a pair of integral equations. Two numerical schemes, a matrix formalism and an iterative method, are programmed for finding numeric solutions to the pair of integral equations. The iterative method had been tried by Fox and Li, but it was not applicable to cases for high Fresnel numbers since the numerical errors involved propagate and accumulate uncontrollably. In this report, we implemented the matrix method to extend the computational limit further. A great deal of case studies are carried out with various configurations of stable and unstable resonators. Our results presented in this report show not only a good agreement with the results previously obtained by Fox and Li, but also a legitimacy of our numerical procedures in high Fresnel numbers.

  7. [Nuclear magnetic resonance tomography].

    Science.gov (United States)

    Ganssen, A; Loeffler, W; Oppelt, A; Schmidt, F

    1981-04-01

    Imaging methods based on nuclear magnetic resonance allow the production of sectional images of the human body without ionizing radiation. It is possible to measure the density and relaxation times of the water protons in body fluids or tissue. This allows not only to obtain morphological information but also to get some insight into the spatial distribution of physiological data. Starting with a review of the principles of nuclear magnetic resonance it is explained how the measured signal can be associated with an image point; it is also explained what type of apparatus is necessary and what the physical limitations are. Possible risks the patient may be exposed to in an examination using nuclear magnetic resonance are discussed. The present state of the technical development enables the production of whole-body sectional images of a living person within about one minute. By means of some typical examples the nature and properties of these images are explained. Although extensive clinical studies will be necessary before a more general assessment can be made of this method, an outlook is provided on expected further developments and possible future fields of application.

  8. Integrated Ring Resonators The Compendium

    CERN Document Server

    Rabus, Dominik G

    2007-01-01

    The optical filter, which has emerged in the last few years in integrated optics, is resonator based. Ring-resonator filters do not require facets or gratings for optical feedback and are thus particularly suited for monolithic integration with other components. Ring resonators find applications not only in optical networks, but also as sensors. The required passband shape of ring resonator-filters can be custom designed by the use of configurations of various ring coupled resonators. This book describes the current state-of-the-art on these devices with respect to design, fabrication and application.

  9. Persistence, resistance, resonance

    Science.gov (United States)

    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

  10. Parametric Resonance in Dynamical Systems

    CERN Document Server

    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...

  11. Superconducting coplanar waveguide resonators for electron spin resonance applications

    Science.gov (United States)

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

    2013-03-01

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

  12. Resonance frequency analysis

    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

  13. 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.

  14. Resonance test system

    Science.gov (United States)

    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.

  15. Nanotube resonator devices

    Science.gov (United States)

    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.

  16. Search for resonant $\\widetilde\

    CERN Document Server

    AUTHOR|(CDS)2072679; 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.

  17. Folded waveguide resonator

    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...... plates are adapted to cause a standing electromagnetic wave to fold around the conductive plates along at least a first and a second direction and to extend on both sides of each of the conductive plates; wherein the conductive plates are adapted to cause the standing electromagnetic wave to fold...

  18. 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%....

  19. Ion cyclotron resonance cell

    Science.gov (United States)

    Weller, R.R.

    1995-02-14

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

  20. Advances in magnetic resonance 11

    CERN Document Server

    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.

  1. GAUSSIAN BEAM LASER RESONATOR PROGRAM

    Science.gov (United States)

    Cross, P. L.

    1994-01-01

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

  2. Efficient primary and parametric resonance excitation of bistable resonators

    KAUST Repository

    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

  3. Theory of Adiabatic Fountain Resonance

    Science.gov (United States)

    Williams, Gary A.

    2017-06-01

    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.

  4. Advances in magnetic resonance 12

    CERN Document Server

    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

  5. Orbital resonances around black holes.

    Science.gov (United States)

    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.

  6. Advances in magnetic resonance 6

    CERN Document Server

    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

  7. Hadron Resonances from QCD

    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.

  8. Resonant High Power Combiners

    CERN Document Server

    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.

  9. Probabilistic interpretation of resonant states

    Indian Academy of Sciences (India)

    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 ...

  10. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic Resonance Imaging ( ...

  11. Resonance-Origins and Usage

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 1. Resonance - Origins and Usage. J Chandrasekhar. Article-in-a-Box Volume 1 Issue 1 January 1996 pp 6-6. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/001/01/0006-0006. Author Affiliations.

  12. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... have special pediatric considerations. The teddy 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) ...

  13. Monopole resonances and Jastrow correlations

    Energy Technology Data Exchange (ETDEWEB)

    Dehesa, J.S.; Guardiola, R. (Granada Univ. (Spain). Dept. de Fisica Nuclear); Polls, A.; Ros, J. (Granada Univ. (Spain). Dept. de Fisica Teorica)

    1982-12-02

    The effect of short range correlations on isoscalar monopole resonances in /sup 4/He, /sup 16/O and /sup 40/Ca is analyzed by using a correlated generator coordinate method. We observe an important increase of the excitation energies of the first resonances with respect to the calculation without src, but small effects on the saturation of the EWSR.

  14. Imperfect Fabry-Perot resonators

    NARCIS (Netherlands)

    Klaassen, Thijs

    2006-01-01

    The initial goal of this thesis was to demonstrate chaos in an open two-mirror resonator. We have designed a bifocal mirror that forms a resonator with an unstable inner and a stable outer part. To be able to distinguish phenomena unique for configuration from phenomena also present in conventional

  15. Delta connected resonant snubber circuit

    Science.gov (United States)

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

    1998-01-20

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

  16. Integrated unaligned resonant modulator tuning

    Science.gov (United States)

    Zortman, William A.; Lentine, Anthony L.

    2017-10-03

    Methods and systems for tuning a resonant modulator are disclosed. One method includes receiving a carrier signal modulated by the resonant modulator with a stream of data having an approximately equal number of high and low bits, determining an average power of the modulated carrier signal, comparing the average power to a predetermined threshold, and operating a tuning device coupled to the resonant modulator based on the comparison of the average power and the predetermined threshold. One system includes an input structure, a plurality of processing elements, and a digital control element. The input structure is configured to receive, from the resonant modulator, a modulated carrier signal. The plurality of processing elements are configured to determine an average power of the modulated carrier signal. The digital control element is configured to operate a tuning device coupled to the resonant modulator based on the average power of the modulated carrier signal.

  17. 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.

  18. Nucleon Resonance Physics

    Energy Technology Data Exchange (ETDEWEB)

    Burkert, Volker D.

    2016-07-25

    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 degrees of freedom underlying the excited states and their dependence on the distance scale probed.

  19. Optofluidic ring resonator dye lasers

    Science.gov (United States)

    Sun, Yuze; Suter, Jonathan D.; Fan, Xudong

    2010-02-01

    We overview the recent progress on optofluidic ring resonator (OFRR) dye lasers developed in our research group. The fluidics and laser cavity design can be divided into three categories: capillary optofluidic ring resonator (COFRR), integrated cylindrical optofluidic ring resonator (ICOFRR), and coupled optofluidic ring resonator (CpOFRR). The COFRR dye laser is based on a micro-sized glass capillary with a wall thickness of a few micrometers. The capillary circular cross-section forms the ring resonator and supports the whispering gallery modes (WGMs) that interact evanescently with the gain medium in the core. The laser cavity structure is versatile to adapt to the gain medium of any refractive index. Owing to the high Q-factor (>109), the lasing threshold of 25 nJ/mm2 is achieved. Besides directly pump the dye molecules, lasing through fluorescence resonance energy transfer (FRET) between the donor and acceptor dye molecules is also studied in COFRR laser. The energy transfer process can be further controlled by designed DNA scaffold labeled with donor/acceptor molecules. The ICOFRR dye laser is based on a cylindrical ring resonator fused onto the inner surface of a thick walled glass capillary. The structure has robust mechanical strength to sustain rapid gain medium circulation. The CpOFRR utilizes a cylindrical ring resonator fused on the inner surface of the COFRR capillary. Since the capillary wall is thin, the individual WGMs of the cylindrical ring resonator and the COFRR couples strongly and forms Vernier effect, which provides a way to generate a single mode dye laser.

  20. Shedding light on diphoton resonances

    Science.gov (United States)

    Craig, Nathaniel; Draper, Patrick; Kilic, Can; Thomas, Scott

    2016-06-01

    The experimental and theoretical implications of heavy digauge 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 digauge boson channels W W , Z Z , γ γ , Z γ , and g g in the form of dijets 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 W W and Z Z to γ γ channels, as well as the longitudinal vs transverse polarization fractions in the W W and Z Z channels, provide probes for possible mixing with the Higgs boson, while di-Higgs and ditop resonant channels, h h and t t , provide somewhat less sensitivity. We present a survey of possible underlying models for digauge boson resonances by considering various limits for the mass of the new charged and strongly interacting matter fields as well as the confinement scale of new hypergauge interactions under which they may also be charged. In these limits, resonances may be included as elementary weakly coupled spin-zero states or can correspond to hyperglueballs, hyperonia, or pseudoscalar hypermesons. For each of these cases, we make predictions for additional states that could be resonantly or pair produced and observed at the Large Hadron Collider or in future collider experiments. Heavy digauge boson resonances can provide a unified explanation for a number of small discrepancies and excesses in reported data from the Large Hadron Collider.

  1. Single-resonator double-negative metamaterial

    Science.gov (United States)

    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.

  2. Advances in magnetic resonance 1

    CERN Document Server

    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

  3. Coupled optical resonance laser locking

    CSIR Research Space (South Africa)

    Burd, CC

    2014-10-01

    Full Text Available . The coupled resonance technique discussed here overcomes this obstacle, and works as follows. If the 2S1/2 → 2P1/2 transition is driven at resonance, there will be a net increase of ions in the 2D3/2 state and a decrease in the population of ions in the ground... stream_source_info Burd_2014.pdf.txt stream_content_type text/plain stream_size 31258 Content-Encoding UTF-8 stream_name Burd_2014.pdf.txt Content-Type text/plain; charset=UTF-8 Coupled optical resonance laser locking S...

  4. Advances in magnetic resonance 9

    CERN Document Server

    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

  5. Nuclear magnetic resonance contrast agents

    Science.gov (United States)

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

    1997-12-30

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

  6. Superresolution Imaging Using Resonant Multiples

    KAUST Repository

    Guo, Bowen

    2017-12-22

    A resonant multiple is defined as a multiple reflection that revisits the same subsurface location along coincident reflection raypaths. We show that resonant first-order multiples can be migrated with either Kirchhoff or wave-equation migration methods to give images with approximately twice the spatial resolution compared to post-stack primary-reflection images. A moveout-correction stacking method is proposed to enhance the signal-to-noise ratios (SNRs) of the resonant multiples before superresolution migration. The effectiveness of this procedure is validated by synthetic and field data tests.

  7. Advances in magnetic resonance 5

    CERN Document Server

    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

  8. Nanoscale nonlinear PANDA ring resonator

    CERN Document Server

    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.

  9. Cardiovascular Magnetic Resonance Imaging

    Science.gov (United States)

    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.

  10. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic Resonance Imaging (MRI) Safety Contrast Materials Children and Radiation Safety Videos related to Children’s ( ...

  11. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... an IV line, into a vein in your hand or arm. A saline solution may be used ... Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic ...

  12. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... Videos About Us News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic ... very early stage by mapping the motion of water molecules in the tissue. This water motion, known ...

  13. Magnetic resonance imaging the basics

    CERN Document Server

    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...

  14. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... be necessary. Your doctor will explain the exact reason why another exam is requested. Sometimes a follow- ... necessary in trauma situations. Although there is no reason to believe that magnetic resonance imaging harms the ...

  15. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... and may cause you and/or others nearby harm. These items include: jewelry, watches, credit cards and ... no reason to believe that magnetic resonance imaging harms the fetus, pregnant women usually are advised not ...

  16. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... magnetic resonance imaging (MRI) uses a powerful magnetic field, radio waves and a computer to produce detailed ... problems, medications, recent surgeries and allergies. The magnetic field is not harmful, but it may cause some ...

  17. 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.

  18. Nested trampoline resonators for optomechanics

    Science.gov (United States)

    Weaver, M. J.; Pepper, B.; Luna, F.; Buters, F. M.; Eerkens, H. J.; Welker, G.; Perock, B.; Heeck, K.; de Man, S.; Bouwmeester, D.

    2016-01-01

    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 trampoline resonators made from low pressure chemical vapor deposition Si3N4 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.

  19. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... have a personal story about radiology? Share your patient story here Images ... (fMRI) - Brain Head and Neck Cancer Treatment Brain Tumor Treatment Magnetic Resonance Imaging (MRI) ...

  20. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... scanner. top of page How does the procedure work? Unlike conventional x-ray examinations and computed tomography ( ... that magnetic resonance imaging harms the fetus, pregnant women usually are advised not to have an MRI ...

  1. Ion Cyclotron Resonance Facility (ICR)

    Data.gov (United States)

    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...

  2. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... is not harmful, but it may cause some medical devices to malfunction. Most orthopedic implants pose no ... Head? Magnetic resonance imaging (MRI) is a noninvasive medical test that physicians use to diagnose medical conditions. ...

  3. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... the same effect. A very irregular heartbeat may affect the quality of images obtained using techniques that ... Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic ...

  4. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... or thyroid problems. Any of these conditions may influence the decision on whether contrast material will be ... bear denotes child-specific content. Related Articles and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's ( ...

  5. Resonate-and-fire neurons.

    Science.gov (United States)

    Izhikevich, E M

    2001-01-01

    We suggest a simple spiking model-resonate-and-fire neuron, which is similar to the integrate-and-fire neuron except that the state variable is complex. The model provides geometric illustrations to many interesting phenomena occurring in biological neurons having subthreshold damped oscillations of membrane potential. For example, such neurons prefer a certain resonant frequency of the input that is nearly equal to their eigenfrequency, they can be excited or inhibited by a doublet (two pulses) depending on its interspike interval, and they can fire in response to an inhibitory input. All these properties could be observed in Hodgkin-Huxley-type models. We use the resonate-and-fire model to illustrate possible sensitivity of biological neurons to the fine temporal structure of the input spike train. Being an analogue of the integrate-and-fire model, the resonate-and-fire model is computationally efficient and suitable for simulations of large networks of spiking neurons.

  6. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... monitors so that your child may watch a movie or TV show during the exam. It is ... patient for magnetic resonance imaging (MRI) exam. View full size with caption Pediatric Content Some imaging tests ...

  7. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... the limitations of MRI of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive ... top of page What are some common uses of the procedure? MR imaging of the head is ...

  8. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... a CD or uploaded to a digital cloud server. Currently, MRI is the most sensitive imaging test ... Brain Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic ...

  9. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... the same effect. A very irregular heartbeat may affect the quality of images obtained using techniques that ... Brain Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to ...

  10. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... have a personal story about radiology? Share your patient story here Images × Image Gallery Magnetic Resonance Imaging (MRI) procedure View full size with caption Pediatric Content Some imaging tests and treatments have special ...

  11. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... patient story here Images × Image Gallery Radiologist prepping patient for magnetic resonance imaging (MRI) exam. View full size with caption Pediatric Content Some imaging tests and treatments have special ...

  12. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... are the limitations of MRI of the Head? What is MRI of the Head? Magnetic resonance imaging ( ... brain) in routine clinical practice. top of page What are some common uses of the procedure? MR ...

  13. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... story about radiology? Share your patient story here Images × Image Gallery Magnetic Resonance Imaging (MRI) procedure View full ... possible charges you will incur. Web page review process: This Web page is reviewed regularly by a ...

  14. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... story about radiology? Share your patient story here Images × Image Gallery Radiologist prepping patient for magnetic resonance imaging ( ... possible charges you will incur. Web page review process: This Web page is reviewed regularly by a ...

  15. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... copied to a CD or uploaded to a digital cloud server. Currently, MRI is the most sensitive ... Brain Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic ...

  16. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... bones of the skull and spine without radiation. MRI of the brain and spine is used to: detect a variety ... and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT ... and Radiation Safety ...

  17. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    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 ...

  18. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    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 ...

  19. Advances in magnetic resonance 4

    CERN Document Server

    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

  20. Advances in magnetic resonance 2

    CERN Document Server

    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.

  1. Triplet State Resonance Raman Spectroscopy

    DEFF Research Database (Denmark)

    Wilbrandt, Robert Walter; Jensen, N. H.; Pagsberg, Palle Bjørn

    1978-01-01

    Makes the first report on the resonance Raman spectrum of a molecule in its triplet state generated by pulse radiolysis. A solution of 0.01 mol dm-3 of p-terphenyl in benzene was studied......Makes the first report on the resonance Raman spectrum of a molecule in its triplet state generated by pulse radiolysis. A solution of 0.01 mol dm-3 of p-terphenyl in benzene was studied...

  2. Thermal Resonance in Signal Transmission

    OpenAIRE

    Reigada Sanz, Ramon; Sarmiento, Antonio; Lindenberg, Katja

    2001-01-01

    We use temperature tuning to control signal propagation in simple one-dimensional arrays of masses connected by hard anharmonic springs and with no local potentials. In our numerical model a sustained signal is applied at one site of a chain immersed in a thermal environment and the signal-to-noise ratio is measured at each oscillator. We show that raising the temperature can lead to enhanced signal propagation along the chain, resulting in thermal resonance effects akin to the resonance obse...

  3. Empathy in schizophrenia: impaired resonance.

    Science.gov (United States)

    Haker, Helene; Rössler, Wulf

    2009-09-01

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

  4. Asymmetric liberations in exterior resonances

    Science.gov (United States)

    Beauge, C.

    1994-10-01

    The purpose of this paper is to present a general analysis of the planar circular restricted problem of three bodies in the case of exterior mean-motion resonances. Particularly, our aim is to map the phase space of various commensurabilities and determine the singular solutions of the averaged system, comparing them to the well-known case of interior resonances. In some commensurabilities (e.g. 1/2, 1/3) we show the existence of asymmetric librations; that is, librations in which the stationary value of the critical angle theta = (p+q) lambda1-p lambda-q pi is not equal to either zero or pi. The origin, stability and morphogenesis of these solutions are discussed and compared to symmetric librations. However, in some other resonances (e.g. 2/3, 3/4), these fixed points of the mean system seem to be absent. Librations in such cases are restricted to theta = O mod(pi). Asymmetric singular solutions of the plane circular problem are unknown in the case of interior resonances and cannot be reproduced by the reduced Andoyer Hamiltonian known as the Second Fundamental Model for Resonance. However, we show that the extended version of this Hamiltonian function, in which harmonics up to order two are considered, can reproduce fairly well the principal topological characteristics of the phase space and thereby constitutes a simple and useful analytical approximation for these resonances.

  5. 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.

  6. Magnetic resonance imaging

    Science.gov (United States)

    Liu, Wei; Fan, Jin; Bai, Jianling; Tang, Pengyu; Chen, Jian; Luo, Yongjun; Zhou, Kuai; Cai, Weihua

    2017-01-01

    Abstract Background and Objectives: Convincing evidence supporting the use of magnetic resonance imaging (MRI) as an effective tool for evaluating cervical sagittal alignment is lacking. This study aims to analyze the differences and correlations between cervical sagittal parameters on x-ray and MRI in patients with cervical disc herniation and to determine whether MRI could substitute for cervical x-ray for measurement of cervical sagittal parameters. Methods: One hundred forty-three adults with cervical disc herniation were recruited. Each patient had both an x-ray and MRI examination of the cervical spine. The cervical sagittal parameters were measured and compared on x-ray and MRI including: C2–C7 Cobb angle, C2–C7 sagittal vertical axis (C2–C7 SVA), cervical tilt (CT), T1 Slope (T1S), and neck tilt (NT). The data were analyzed using a paired-samples t test, a Pearson correlation test, and linear regression. Results: The values of C2–C7 Cobb angle, C2–C7 SVA, CT and T1S on X-ray were larger than those on MRI (P sagittal parameters had a significant correlation with the corresponding one on MRI (r = 0.699, 0.585, 0.574, 0.579 and 0.613, respectively) (C2–C7 Cobb MRI = 0.957 + 0.721 C2–C7 Cobb X, C2–C7 SVA MRI = 6.423 + 0.500 C2–C7 SVAX, CT MRI = 3.121 + 0.718 CTX, T1S MRI = 7.416 + 0.613 T1SX, NT MRI = 22.548 + 0.601 NTX). Conclusion: Although MRI and x-ray measurements of cervical sagittal parameters were different, there were significant correlations between the results. MRI could be used to evaluate the sagittal balance of the cervical spine with great reliability. PMID:28953681

  7. Magnetic resonance force detection using a membrane resonator.

    Science.gov (United States)

    Scozzaro, N; Ruchotzke, W; Belding, A; Cardellino, J; Blomberg, E C; McCullian, B A; Bhallamudi, V P; Pelekhov, D V; Hammel, P C

    2016-10-01

    The availability of compact, low-cost magnetic resonance imaging instruments would further broaden the substantial impact of this technology. We report highly sensitive detection of magnetic resonance using low-stress silicon nitride (SiNx) membranes. We use these membranes as low-loss, high-frequency mechanical oscillators and find they are able to mechanically detect spin-dependent forces with high sensitivity enabling ultrasensitive magnetic resonance detection. The high force detection sensitivity stems from their high mechanical quality factor Q∼10(6)[1,2] combined with the low mass of the resonator. We use this excellent mechanical force sensitivity to detect the electron spin magnetic resonance using a SiNx membrane as a force detector. The demonstrated force sensitivity at 300K is 4fN/Hz, indicating a potential low temperature (4K) sensitivity of 25aN/Hz. Given their sensitivity, robust construction, large surface area and low cost, SiNx membranes can potentially serve as the central component of a compact room-temperature ESR and NMR instrument having spatial resolution superior to conventional approaches. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. 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....

  9. Highly Tunable Electrostatic Nanomechanical Resonators

    KAUST Repository

    Kazmi, Syed Naveed Riaz

    2017-11-24

    There has been significant interest towards highly tunable resonators for on-demand frequency selection in modern communication systems. Here, we report highly tunable electrostatically actuated silicon-based nanomechanical resonators. In-plane doubly-clamped bridges, slightly curved as shallow arches due to residual stresses, are fabricated using standard electron beam lithography and surface nanomachining. The resonators are designed such that the effect of mid-plane stretching dominates the softening effect of the electrostatic force. This is achieved by controlling the gap-to-thickness ratio and by exploiting the initial curvature of the structure from fabrication. We demonstrate considerable increase in the resonance frequency of nanoresonators with the dc bias voltages up to 108% for 180 nm thick structures with a transduction gap of 1 $mu$m separating them from the driving/sensing electrodes. The experimental results are found in good agreement with those of a nonlinear analytical model based on the Euler-Bernoulli beam theory. As a potential application, we demonstrate a tunable narrow band-pass filter using two electrically coupled nanomechanical arch resonators with varied dc bias voltages.

  10. Magnetic Resonance with Squeezed Microwaves

    Science.gov (United States)

    Bienfait, A.; Campagne-Ibarcq, P.; Kiilerich, A. H.; Zhou, X.; Probst, S.; Pla, J. J.; Schenkel, T.; Vion, D.; Esteve, D.; Morton, J. J. L.; Moelmer, K.; Bertet, P.

    2017-10-01

    Vacuum fluctuations of the electromagnetic field set a fundamental limit to the sensitivity of a variety of measurements, including magnetic resonance spectroscopy. We report the use of squeezed microwave fields, which are engineered quantum states of light for which fluctuations in one field quadrature are reduced below the vacuum level, to enhance the detection sensitivity of an ensemble of electronic spins at millikelvin temperatures. By shining a squeezed vacuum state on the input port of a microwave resonator containing the spins, we obtain a 1.2-dB noise reduction at the spectrometer output compared to the case of a vacuum input. This result constitutes a proof of principle of the application of quantum metrology to magnetic resonance spectroscopy.

  11. Resonance Ionization Laser Ion Sources

    CERN Document Server

    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...

  12. Photoproduction of exotic baryon resonances

    Directory of Open Access Journals (Sweden)

    Marek Karliner

    2016-01-01

    Full Text Available We point out that the new exotic resonances recently reported by LHCb in the J/ψp channel are excellent candidates for photoproduction off a proton target. This test is crucial to confirming the resonant nature of such states, as opposed to their being kinematical effects. We specialize to an interpretation of the heavier narrow state as a molecule composed of Σc and D¯⁎, and estimate its production cross section using vector dominance. The relevant photon energies and fluxes are well within the capabilities of the GlueX and CLAS12 detectors at Thomas Jefferson National Accelerator Facility (JLAB. A corresponding calculation is also performed for photoproduction of an analogous resonance which is predicted to exist in the ϒp channel.

  13. Extended Fundamental Model of Resonance

    Science.gov (United States)

    Breiter, Sławomir

    2003-03-01

    Fundamental models are the simplest, one degree of freedom Hamiltonians that serve as a tool to understand the qualitative effects of various resonances. A new, extended fundamental model (EFM) is proposed in order to improve the classical, Andoyer type, second fundamental model (SFM). The EFM Hamiltonian differs from the SFM by the addition of a term with the third power of momentum; it depends on two free parameters. The new model is studied for the case of a first-order resonance, where up to five critical points can be present. Similarly, to the respective SFM, it admits only the saddle-node bifurcations of critical points, but its advantage lies in the capability of generating the separatrix bifurcations, known also as saddle connections. The reduction of parameters for the EFM has been performed in a way that allows the use of the model in the case of the so-called abnormal resonance.

  14. Interventional Cardiovascular Magnetic Resonance Imaging

    Science.gov (United States)

    Saikus, Christina E.; Lederman, Robert J.

    2010-01-01

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

  15. Resonant-state perturbation formalisms

    Energy Technology Data Exchange (ETDEWEB)

    Romo, W.J. (Carleton Univ., Ottawa, Ontario (Canada). Dept. of Physics)

    1983-05-02

    Three different formalisms for determining bound-state, virtual-state, and resonant-state energies of a perturbed system are developed. Two of the formalisms are based on expansions of the unperturbed Green function in terms of bound-state, resonant-state and deformed-continuum-state contributions of the form developed by T. Berggren. The third formalism is based on a Mittag-Leffler expansion of the unperturbed Green function. The three formalisms are compared and the relative merits of calculation schemes based on them are examined.

  16. Optical Microbottle Resonators for Sensing

    Directory of Open Access Journals (Sweden)

    Pablo Bianucci

    2016-11-01

    Full Text Available Whispering gallery mode (WGM optical microresonators have been shown to be the basis for sensors able to detect minute changes in their environment. This has made them a well-established platform for highly sensitive physical, chemical, and biological sensors. Microbottle resonators (MBR are a type of WGM optical microresonator. They share characteristics with other, more established, resonator geometries such as cylinders and spheres, while presenting their unique spectral signature and other distinguishing features. In this review, we discuss recent advances in the theory and fabrication of different kinds of MBRs, including hollow ones, and their application to optofluidic sensing.

  17. Advances in magnetic resonance 8

    CERN Document Server

    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

  18. Migraine and magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Younis, Samaira; Hougaard, Anders; Vestergaard, Mark B.

    2017-01-01

    Purpose of review: To present an updated and streamlined overview of the metabolic and biochemical aspect of the migraine pathophysiology based on findings from phosphorous (31P) and hydrogen (1H) magnetic resonance spectroscopy (MRS) studies. Recent findings: Despite of the variation in the meth......Purpose of review: To present an updated and streamlined overview of the metabolic and biochemical aspect of the migraine pathophysiology based on findings from phosphorous (31P) and hydrogen (1H) magnetic resonance spectroscopy (MRS) studies. Recent findings: Despite of the variation...

  19. Efficient Measurement of Superconducting Resonators

    Science.gov (United States)

    Sendelbach, Steven; Stoutimore, Micah; Strong, Josh; Naaman, Ofer; Campbell, Brooks; Martinis, John

    2014-03-01

    S-parameter measurements of high-Q superconducting resonators at single-photon drive powers often require significant averaging with associated long acquisition time. We have developed a procedure for optimizing the frequency sweep-plan of the measurement, and found that an appropriate choice of frequencies has a significant impact on its efficiency. An optimized sweep-plan design offers up to a factor of two reduction in the variance of extracted parameters, in comparison to a linear sweep-plan having the same total acquisition time. We experimentally compare the performance of the optimized and linear sweeps in measurements of high-Q aluminum CPW resonators.

  20. 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......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...

  1. Nanoelectromechanical resonator for logic operations

    KAUST Repository

    Kazmi, Syed N. R.

    2017-08-29

    We report an electro-thermally tunable in-plane doubly-clamped nanoelectromechanical resonator capable of dynamically performing NOR, NOT, XNOR, XOR, and AND logic operations. Toward this, a silicon based resonator is fabricated using standard e-beam lithography and surface nanomachining of a highly conductive device layer of a silicon-on-insulator (SOI) wafer. The performance of this logic device is examined at elevated temperatures, ranging from 25 °C to 85 °C, demonstrating its resilience for most of the logic operations; thereby paving the way towards nano-elements-based mechanical computing.

  2. $0^{++}$ Resonances Observed at BES

    OpenAIRE

    Zou, B. S.; Collaboration, for BES

    2008-01-01

    In last 10 years, $0^{++}$ resonances have been observed and studied at BES in many processes, such as $J/\\psi\\to\\gamma\\pi^+\\pi^-\\pi^+\\pi^-$, $\\gamma\\pi^+\\pi^-$, $\\gamma\\pi^0\\pi^0$, $\\gamma K^+K^-$, $\\gamma K_SK_S$, $\\gamma\\omega\\phi$, $\\omega\\pi^+\\pi^-$, $\\omega K^+K^-$, $\\phi\\pi^+\\pi^-$, $\\phi K^+K^-$, $\\psi(2S)\\to J/\\psi\\pi^+\\pi^-$, $\\chi_{c0}\\to\\pi^+\\pi^-K^+K^-$, $\\pi^+\\pi^-\\pi^+\\pi^-$ etc.. The results on $0^{++}$ resonances observed at BES are reviewed.

  3. 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.

  4. Stochastic resonance and chaotic resonance in bimodal maps: A ...

    Indian Academy of Sciences (India)

    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 ...

  5. Stochastic resonance and chaotic resonance in bimodal maps: A ...

    Indian Academy of Sciences (India)

    Abstract. 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 ...

  6. 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.

  7. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    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 medical conditions. MRI ...

  8. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    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 medical conditions. MRI ...

  9. Low field magnetic resonance imaging

    Science.gov (United States)

    Pines, Alexander; Sakellariou, Dimitrios; Meriles, Carlos A.; Trabesinger, Andreas H.

    2010-07-13

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

  10. Linearization of hyperbolic resonant germs

    NARCIS (Netherlands)

    Bonckaert, P; Naudot, [No Value; Yang, JH

    In this paper we develop an explicit normal form conjugacy procedure, called an 'LMT normal form', to study linearization of a smooth vector field in the neighbourhood of a hyperbolic equilibrium point with resonant eigenvalues. We give an asymptotic expression for such a linearization in terms of

  11. 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.

  12. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... the brain caused by an injury or a stroke diagnose infectious or autoimmune diseases like encephalopathy or ... broad range of conditions, including cancer, heart and vascular disease, and muscular and bone ... (Pediatric) CT (Computed Tomography) Magnetic Resonance Imaging ( ...

  13. Probabilistic interpretation of resonant states

    Indian Academy of Sciences (India)

    This is in contrast with the conventional employment of a bi-orthogonal basis that precludes probabilistic interpretation, since wave ... In many textbooks, resonance is defined as a pole of the S matrix. It is, however, ..... [1] M Razavy, Quantum theory of tunneling §§5.2 & 5.3 (World Scientific, Singapore,. 2003) and references ...

  14. Resonance | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Resonance. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. Theory Of Evolution. Posted on 23 January 2018. Joint Statement by the Three Science Academies of India on the teaching ...

  15. 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...

  16. R-ES-ONAN-CE

    Indian Academy of Sciences (India)

    Resonance iournal of science education. March 1997 Volume 2 Number 3. SERIES ARTICLES. 8 The Challenge of Weather Prediction. Old and Modern Ways of Weather Forecasting. B N Goswami. 16 Algorithms. Algorithms for Sorting and. Searching. R K Shyamasundar. 33 Error Correcting Codes. Reed Solomon Codes.

  17. Model for resonant plasma probe.

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-04-01

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

  18. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... are the limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is ... top of page What are some common uses of the procedure? MRI is used to help diagnose ...

  19. Resonance journal of science education

    Indian Academy of Sciences (India)

    IAS Admin

    Resonance journal of science education. January 2016 Volume 21 Number 1. GENERALARTICLES. 11. IEEE Standard for Floating Point Numbers. V Rajaraman ... Refresher Course on Mountain Hydrology and. Climate Change. Science Academies' Seventy-Fifth Refresher Course in Experimental Physics. Information & ...

  20. Resonance iournal of science education

    Indian Academy of Sciences (India)

    Kaun Banega Crorepati-AMiIIlon Dollars for a. I'Aathernatk:lan. Poincare Coniecture. M S Raghunathan. 56. --------~--------. 6. RESONANCE I September 2002. Page 2. 69 Haber Process for Ammonia Synthesis. Jayant M Modak. 86 CLASSICS. The Synthesis of Ammonia from its Elements. Fritz Haber. Front Cover. Nitrogen ...

  1. Performance of thermally excited resonators

    NARCIS (Netherlands)

    Lammerink, Theodorus S.J.; Elwenspoek, Michael Curt; van Ouwerkerk, R.H.; Bouwstra, S.; Bouwstra, S.; Fluitman, J.H.J.

    A study of electrothermal excitation of micro-machined silicon beams is reported. The temperature distribution is calculated as a function of the position of the transducer, resulting in stress in the structure which reduces the resonance frequency. Test samples are realized and measurements or

  2. 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.

  3. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... What are the limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) ... to a digital cloud server. top of page What are some common uses of the procedure? MRI ...

  4. ENZYME CATALYTIC RESONANCE SCATTERING SPECTRAL ...

    African Journals Online (AJOL)

    Preferred Customer

    ABSTRACT. Hydrogen peroxide oxidized guaiacol to form tetramer particles that exhibited a strong resonance scattering (RS) peak at 530 nm in the presence of horseradish peroxidase (HRP) in citric acid-Na2HPO4 buffer solution of pH 4.4. The RS peak increased when the concentration of hydrogen peroxide increased.

  5. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... of which shows a thin slice of the body. The images can then be studied from different angles by ... about radiology? Share your patient story here Images ... Articles and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's ( ...

  6. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... of which shows a thin slice of the body. The images can then be studied from different angles by ... about radiology? Share your patient story here Images ... Related Articles and Media MR Angiography (MRA) Magnetic Resonance, Functional (fMRI) - Brain ...

  7. Jet-associated resonance spectroscopy

    Science.gov (United States)

    Englert, Christoph; Ferretti, Gabriele; Spannowsky, Michael

    2017-12-01

    We present a model-independent study aimed at characterising the nature of possible resonances in the jet-photon or jet- Z final state at hadron colliders. Such resonances are expected in many models of compositeness and would be a clear indication of new physics. At leading order, in the narrow width approximation, the matrix elements are parameterised by just a few constants describing the coupling of the various helicities to the resonance. We present the full structure of such amplitudes up to spin 2 and use them to simulate relevant kinematic distributions that could serve to constrain the coupling structure. This also generalises the signal generation strategy that is currently pursued by ATLAS and CMS to the most general case in the considered channels. While the determination of the P/CP properties of the interaction seems to be out of reach within this framework, there is a wealth of information to be gained about the spin of the resonance and the relative couplings of the helicities.

  8. Neutron resonances in planar waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Kozhevnikov, S. V., E-mail: kozhevn@nf.jinr.ru, E-mail: kzh-sv@mail.ru; Ignatovich, V. K.; Petrenko, A. V. [Joint Institute for Nuclear Research, Neutron Physics Laboratory (Russian Federation); Radu, F. [Helmholtz-Zentrum Berlin für Materialen und Energie (Germany)

    2016-12-15

    We report on the results of the experimental investigation of the spectral width of neutron resonances in planar waveguides using the time-of-flight method and recording the microbeam emerging from the waveguide end. Experimental data are compared with the results of theoretical calculations.

  9. 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...

  10. Coupled-resonator optical waveguides

    DEFF Research Database (Denmark)

    Raza, Søren; Grgic, Jure; Pedersen, Jesper Goor

    2010-01-01

    to ideal resonators without any damping. However, the maximal group delay that can be envisioned is a balance between having a low group velocity while not jeopardizing the propagation length. We find that the maximal group delay remains roughly constant over the entire bandwidth, being given by the photon...

  11. Resonance journal of science education

    Indian Academy of Sciences (India)

    IAS Admin

    384. A Visit to the South Pole. Adventures of the First Indian to Winter-Over the. South Pole and Explore Antarctica. Parmjit Singh Sehra. 302. 363. 321. Page 2. 301. RESONANCE | April 2010. DEPARTMENTS. Editorial. G K Ananthasuresh. Gharial, a critically endangered reptile with an estimated adult population of 200 in ...

  12. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... if a finding is stable or changed over time. top of page What are the benefits vs. risks? Benefits MRI is a ... resonance imaging harms the fetus, pregnant women usually are advised not to have an ... take more time to perform than other imaging modalities. top of ...

  13. 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.

  14. 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

  15. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... structures of the brain and can also provide functional information (fMRI) in selected cases. MR images of ... Articles and Media MR Angiography (MRA) Magnetic Resonance, Functional (fMRI) - Brain Head and Neck Cancer Treatment Brain ...

  16. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... Children’s magnetic resonance imaging (MRI) uses a powerful magnetic field, radio waves and a computer to produce detailed ... health problems, medications, recent surgeries and allergies. The magnetic field is not harmful, but it may cause some ...

  17. 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...

  18. R-ES-ON--ANCE

    Indian Academy of Sciences (India)

    More commonly, the word is associated with music. (resonance of a piano or organ) and in a figurative sense with positive qualities. These are evident in the following powerful phrases: 'For the beaute, for the force and for the resonaunce' (Ordinary Crysten. Men, 1502) and in the pious wish: "So ought our hearts ... to have ...

  19. A tunable electromechanical Helmholtz resonator

    Science.gov (United States)

    Liu, Fei

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

  20. Magnetic Resonance Imaging (MRI): Brain (For Parents)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Magnetic Resonance Imaging (MRI): Brain KidsHealth / For Parents / Magnetic Resonance Imaging (MRI): Brain What's in this article? What It ...

  1. Magnetic Resonance Imaging (MRI): Dynamic Pelvic Floor

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) – Dynamic Pelvic Floor Dynamic pelvic floor magnetic resonance imaging (MRI) is a noninvasive test that uses a ...

  2. International Society for Magnetic Resonance in Medicine

    Science.gov (United States)

    ... information. And check out the MRM blog: Magnetic Resonance in Medicine Highlights Featured Journal Research Submit Research | ... Meetings Connect With Us International Society for Magnetic Resonance in Medicine 2300 Clayton Road, Suite 620 | Concord, ...

  3. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography (MRA) Transcript Welcome to Radiology Info dot ... d like to talk with you about magnetic resonance angiography, or as it’s commonly known, MRA. MRA ...

  4. Glass cavity resonators for low microwave frequencies

    Science.gov (United States)

    Howson, D. P.; Hamer, G.

    1995-05-01

    A series of experiments were undertaken to confirm the feasibility of the use of various glasses as walls in microwave cavity resonators with the objective of achieving low drift of resonant frequency with temperature.

  5. 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....

  6. Study of resonance in wind parks

    OpenAIRE

    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...

  7. Magnetic Resonance Imaging (MRI) (For Parents)

    Science.gov (United States)

    ... Help a Child Cope With a Parent's Suicide? Magnetic Resonance Imaging (MRI) KidsHealth > For Parents > Magnetic Resonance Imaging (MRI) Print A A A What's ... Child If You Have Questions What It Is Magnetic resonance imaging (MRI) is a safe and painless ...

  8. resonant inverter supplied interior permanent magnet (ipm)

    African Journals Online (AJOL)

    user

    ABSTRACT. In this paper, rotor position in relation to the resonant frequency component current in the stator winding of DC-voltage link resonant inverter supplied Interior Permanent Magnet. (IPM) motor has been developed. Six reference frames are used to relate the rotor position angle to the resonant frequency ...

  9. Enriched vibrational resonance in certain discrete systems

    Indian Academy of Sciences (India)

    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 ...

  10. Waveguide couplers for ferroelectric optical resonators

    OpenAIRE

    Grudinin, Ivan S.; Kozhanov, A.; Yu, N.

    2014-01-01

    We report a study of using the same material to fabricate a whispering gallery mode resonator and a coupler. Coupling to high Q whispering gallery modes of the lithium niobate resonator is demonstrated by means of the titanium-doped waveguide. The waveguide coupling approach opens possibilities for simpler and wider practical usage of whispering gallery mode resonators and their integration into optical devices.

  11. ON THE RESONANT FREQUENCIES OF THE OJA

    African Journals Online (AJOL)

    Dr Obe

    1997-09-01

    Sep 1, 1997 ... It is also shown that for resonant frequencies below about 2000Hz, the differences between the theoretical and experimental data are in qualitative agreement with the findings of earlier investigators with regard to the effect of a mouth-cavity resonance on the resonant frequencies of a wood-wind instrument ...

  12. 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...

  13. Single and Double Superconducting Coplanar Waveguide Resonators

    Science.gov (United States)

    Zhao, Na; Liu, Jian-She; Li, Hao; Li, Tie-Fu; Chen, Wei

    2012-08-01

    Transmission characteristics of single and double coplanar waveguide (CPW) resonators are simulated. The crosstalk of two CPW resonators located on the same chip is observed in simulation as well as in low temperature measurement results. The crosstalk behaves as exponential attenuation versus the distance between two resonators.

  14. Resonance Raman spectroscopic investigation of MLCT character ...

    Indian Academy of Sciences (India)

    Administrator

    Resonance Raman spectroscopy, because of its utility in understanding resonant state dynamics and structure, is an ideal tool to investigate MLCT states of inorganic complexes. In particular, the tunability of the excitation wavelength and thus the resulting resonance Raman intensities provide information on the nuclear ...

  15. Resonant activation of population extinctions

    Science.gov (United States)

    Spalding, Christopher; Doering, Charles R.; Flierl, Glenn R.

    2017-10-01

    Understanding the mechanisms governing population extinctions is of key importance to many problems in ecology and evolution. Stochastic factors are known to play a central role in extinction, but the interactions between a population's demographic stochasticity and environmental noise remain poorly understood. Here we model environmental forcing as a stochastic fluctuation between two states, one with a higher death rate than the other. We find that, in general, there exists a rate of fluctuations that minimizes the mean time to extinction, a phenomenon previously dubbed "resonant activation." We develop a heuristic description of the phenomenon, together with a criterion for the existence of resonant activation. Specifically, the minimum extinction time arises as a result of the system approaching a scenario wherein the severity of rare events is balanced by the time interval between them. We discuss our findings within the context of more general forms of environmental noise and suggest potential applications to evolutionary models.

  16. Magnetic Resonance Force Microscope Development

    Energy Technology Data Exchange (ETDEWEB)

    Hammel, P.C.; Zhang, Z.; Suh, B.J.; Roukes, M.L.; Midzor, M.; Wigen, P.E.; Childress, J.R.

    1999-06-03

    Our objectives were to develop the Magnetic Resonance Force Microscope (MRFM) into an instrument capable of scientific studies of buried structures in technologically and scientifically important electronic materials such as magnetic multilayer materials. This work resulted in the successful demonstration of MRFM-detected ferromagnetic resonance (FMR) as a microscopic characterization tool for thin magnetic films. Strong FMR spectra obtained from microscopic Co thin films (500 and 1000 angstroms thick and 40 x 200 microns in lateral extent) allowed us to observe variations in sample inhomogeneity and magnetic anisotropy field. We demonstrated lateral imaging in microscopic FMR for the first time using a novel approach employing a spatially selective local field generated by a small magnetically polarized spherical crystallite of yttrium iron garnet. These successful applications of the MRFM in materials studies provided the basis for our successful proposal to DOE/BES to employ the MRF M in studies of buried interfaces in magnetic materials.

  17. Simultaneous electrical and mechanical resonance drive for large signal amplification of micro resonators

    KAUST Repository

    Hasan, M. H.

    2018-01-12

    Achieving large signal-noise ratio using low levels of excitation signal is key requirement for practical applications of micro and nano electromechanical resonators. In this work, we introduce the double electromechanical resonance drive concept to achieve an order-of-magnitude dynamic signal amplification in micro resonators. The concept relies on simultaneously activating the micro-resonator mechanical and electrical resonance frequencies. We report an input voltage amplification up to 15 times for a micro-resonator when its electrical resonance is tuned to match the mechanical resonance that leads to dynamic signal amplification in air (Quality factor enhancement). Furthermore, using a multi-frequency excitation technique, input voltage and vibrational amplification of up to 30 times were shown for the same micro-resonator while relaxing the need to match its mechanical and electrical resonances.

  18. Magnetic resonance imaging in hemosiderosis

    Energy Technology Data Exchange (ETDEWEB)

    Kessing, P.H.L.; Falke, T.H.M.; Steiner, R.M.; Bloem, H.; Peters, A. (Rijksuniversiteit Leiden (Netherlands). Academisch Ziekenhuis)

    1985-01-15

    The case of a patient with iron deposition disease is presented to illustrate the value of magnetic resonance imaging (MRI) in the evaluation of this entity. The image characteristics of MRI are discussed and the results are compared with those of computer tomography (CT). The importance of a decrease in T2 relaxation time as the determinant parameter for signal intensity in MRI of the liver in such patients is emphasized.

  19. Magnetic resonance and its applications

    CERN Document Server

    Chizhik, Vladimir I; Donets, Alexey V; Frolov, Vyacheslav V; Komolkin, Andrei V; Shelyapina, Marina G

    2014-01-01

    The book provides a basic understanding of the underlying theory, fundamentals and applications of magnetic resonance The book implies a few levels of the consideration (from simple to complex) of phenomena, that can be useful for different groups of readers The introductory chapter provides the necessary underpinning knowledge for newcomers to the methods The exposition of theoretical materials goes from initial to final formulas through detailed intermediate expressions.

  20. Dynamic control of chaotic resonators

    KAUST Repository

    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.

  1. 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.

  2. Proton Resonance Spectroscopy -- Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Shriner, Jr., J. F. [Tennessee Technological Univ., Cookeville, TN (United States)

    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.

  3. 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.

  4. Bidirectional resonant tunneling spin pump

    OpenAIRE

    Ting, David Z. -Y.; Cartoixà Soler, Xavier

    2003-01-01

    We propose a mechanism for achieving bidirectional spin pumping in conventional nonmagnetic semiconductorresonant tunnelingheterostructures under zero magnetic field. The device is designed specifically to take advantage of the special spin configuration described by the Rashba effect in asymmetric quantum wells. It induces the simultaneous flow of oppositely spin-polarized current components in opposite directions through spin-dependent resonant tunneling, and can thus generate significant l...

  5. Multi Resonance Shear Mode Transducers

    Science.gov (United States)

    2016-11-21

    and a central mass (cross-hatched). The resonance frequency of each motor section can be controlled through the dimensions (width, height or...modeled using ATILA++ finite element code. Refinements were made to the central mass geometry and materials to produce a desirable frequency response...scanning laser vibrometer. In-air testing was done on the finished unit. These data were compared to model predictions. Figure 2 Model (1 /4 symmetry

  6. Resonant circuit model for efficient metamaterial absorber.

    Science.gov (United States)

    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.

  7. Zeroth-order resonance phenomenon in an acoustic composite right/left-handed metamaterial resonator.

    Science.gov (United States)

    Kim, Wan-Gu; Kang, Hwi Suk; Yoon, Suk Wang; Lee, Kang Il

    2017-10-01

    This study proposes an acoustic theory that describes the resonance phenomena in a resonator made of acoustic composite right/left-handed (CRLH) metamaterials, and verifies it through numerical simulation. The established theory for a microwave CRLH metamaterial resonator is adapted to explain the resonance phenomena in an acoustic CRLH metamaterial resonator. In particular, attention is focused on the zeroth-order resonance phenomenon which has several interesting properties. When a resonator is composed of a CRLH metamaterial, a resonance with a flat acoustic field distribution may occur at one of the frequencies where the wavenumber becomes zero. This resonance is called zeroth-order resonance. Through numerical simulation, such unusual resonance phenomenon in acoustics is observed in more detail and the proposed theory is verified. The results of the theory and the numerical simulation clearly show that zeroth-order resonance can exist at those frequencies where the acoustic field distribution is flat due to infinite wavelength. It is also shown that the resonance frequency and the Q factor of this resonance depend on the boundary condition at both ends of the resonator, and they basically do not change even when the number of units is reduced or increased.

  8. Seismic resonances of acoustic cavities

    Science.gov (United States)

    Schneider, F. M.; Esterhazy, S.; Perugia, I.; Bokelmann, G.

    2016-12-01

    The goal of an On-Site Inspection (OSI) is to clarify at a possible testsite whether a member state of the Comprehensive nuclear Test Ban Treaty (CTBT)has violated its rules by conducting a underground nuclear test. Compared toatmospheric and underwater tests underground nuclear explosions are the mostdifficult to detect.One primary structural target for the field team during an OSI is the detectionof an underground cavity, created by underground nuclear explosions. Theapplication of seismic-resonances of the cavity for its detection has beenproposed in the CTBT by mentioning "resonance seismometry" as possibletechnique during OSIs. We modeled the interaction of a seismic wave-field withan underground cavity by a sphere filled with an acoustic medium surrounded byan elastic full space. For this setting the solution of the seismic wave-fieldcan be computed analytically. Using this approach the appearance of acousticresonances can be predicted in the theoretical calculations. Resonance peaksappear in the spectrum derived for the elastic domain surrounding the acousticcavity, which scale in width with the density of the acoustic medium. For lowdensities in the acoustic medium as for an gas-filled cavity, the spectralpeaks become very narrow and therefore hard to resolve. The resonancefrequencies, however can be correlated to the discrete set of eigenmodes of theacoustic cavity and can thus be predicted if the dimension of the cavity isknown. Origin of the resonance peaks are internal reverberations of wavescoupling in the acoustic domain and causing an echoing signal that couples outto the elastic domain again. In the gas-filled case the amplitudes in timedomain are very low.Beside theoretical considerations we seek to find real data examples fromsimilar settings. As example we analyze a 3D active seismic data set fromFelsőpetény, Hungary that has been conducted between 2012 and 2014 on behalf ofthe CTBTO. In the subsurface of this area a former clay mine is

  9. RESONANCE

    Indian Academy of Sciences (India)

    they should prefer to invest in their sisters and brothers in the ratio 3: 1 (0.75 : 0.25). A particu- larly fascinating aspect of this prediction is that the workers' preferred ratio of investment (3: 1) is in conflict with the queen's preferred ratio of investment of 1: 1 in her daughters and sons. Hamilton's prediction and the prediction of.

  10. RESONANCE

    Indian Academy of Sciences (India)

    grew into a veritable legend, he more and more became the very conscience of the community of theoretical physicists. "His critical nature helped him foresee difficulties exceedingly quickly, and probably held back his own creativity. Tomonaga has characterised the situation thus: " ... Pauli's perfectionism was phenomenal.

  11. RESONANCE

    Indian Academy of Sciences (India)

    The word supercomputer was coined in the late 70s to describe a machine which was built by Seymour Cray while he was a designer with the Control Data Corporation and designed the. CDC 7600 which was at that time one order of magnitude faster than the fastest computers of the day. At that time the two major.

  12. RESONANCE

    Indian Academy of Sciences (India)

    On the other hand. (and this is one of my major complaints), the author has been completely (and inexplicably) silent on his scientific interactions with Prof. GNR. The book would certainly have been richer had the author shared with the readers how it was to work with his research supervisor. Another negative point is the.

  13. RESONANCE

    Indian Academy of Sciences (India)

    The debris of pine accumulates as it takes a long time to decompose; the intervening period is one of high fire risk. In the deciduous forests of southern India, leaf shedding begins early in the year and by April the ground below is covered with large amounts of litter. This pattern in leaf shedding is common in the Mudumalai, ...

  14. RESONANCE

    Indian Academy of Sciences (India)

    Without undue emphasis on psychoanalysis, however, Westfall's book makes the point that such a beginning contributed to the loneliness, isolation and the accompanying neuroses and obsessions in Newton's later years. Even the formative years at the grammar school showed how his mind would work in his prime years.

  15. RESONANCE

    Indian Academy of Sciences (India)

    quadratic equations to the golden period in. Italian mathematics (Fibonacci: A.D. 1180-. 1240, del Ferro, Tartaglia, Cardano and. Ferrari: A.D. 1450-1580). It is during this period in Italy that the seeds of modern algebra were sown. There was the solution of the cubic by del Ferro, the controversy between Tartaglia.

  16. RESONANCE

    Indian Academy of Sciences (India)

    In an article on cognitive psychology, Kamala Mukunda takes us behind the retina to tell us how and where we actually 'see' anything in its wholeness; in the Classroom Section we learn of the difficulties of teaching Darwinian evolution. The almost universal tendency to think along Lamarckian lines here reminds.

  17. RESONANCE

    Indian Academy of Sciences (India)

    "if you miss the Ascension, your wife gets a pension." Early tagging studies demonstrated that the same turtles returned to Ascension year after year. DNA studies have shown that this population was distinct from other green turtle populations, strengthening the claim that they show high site-fidelity, and also that the turtles.

  18. RESONANCE

    Indian Academy of Sciences (India)

    Vainu Bappu was probably my closest friend. For. 33 years the strands of our lives have interwoven, even to the extent of his being best man at my wedding, and my just missing (because of aca- demic schedules) being something of an equiva- lent at his wedding in India. I mention this be- cause so few now in the IAU have ...

  19. resonance

    Indian Academy of Sciences (India)

    American in the Library of the National. College, Basavanagudi, Bangalore, that is res- ponsible for many of us who studied there taking to Science as a career. One of the books. I particularly remember is a Kannada adap- tation, VichitralOkadalli Vidyalankara ,of Mr. Tompkinsin WonderlandbyB V Subbaryappa;. Gamow ...

  20. RESONANCE

    Indian Academy of Sciences (India)

    house in London. He also dispensed a considerable sum of money to various relatives in need. "Newton's charity works to soften the image left by the quarrels with Flamsteed and Leibniz. The quarrels were real. So was the charity to unfortunates, as though he hoped to compensate for his own short- comings.

  1. Resonance

    Indian Academy of Sciences (India)

    IAS Admin

    Demand draft or Money order is preferred. ❖ Drafts are to be drawn in favour of. INDIAN ACADEMY OF SCIENCES. ❖ For renewals, please quote subscription number. ❖ Use photo copies if more order forms are required;. ❖ Accepted for calendar year (January–December) only. ❖ Personal subscriptions accepted for a ...

  2. RESONANCE

    Indian Academy of Sciences (India)

    Success might be much hastened by an association of searchers in this field of inquiry [flight j, for no one man is likely to be simultaneously an inventor to imagine new shapes and new motors, a mechanical engineer to design the arrangement of the apparatus, a mathematician to calculate its strength and stresses, ...

  3. RESONANCE

    Indian Academy of Sciences (India)

    views on evolution. Chesterton is the more easily dealt with. He is greatly impressed by the fact that some prehistoric men drew pictures, and points out that they are presumably quite human from the psychological point of view, and quite different from animals. Now the earliest known art is of the Aurignacian period, ...

  4. RESONANCE

    Indian Academy of Sciences (India)

    circle well. He is really a highly abstract thinker and went into mathematical logic, which was perfect for him. This was not Einstein's style. Einstein grasped the world in ... professors at the Swiss Technical University, as well as his being a Jew, probably explain his .... few people can actually work under such conditions.

  5. Resonance

    Indian Academy of Sciences (India)

    Administrator

    Refresher Course in. Experimental Physics. Refresher Course on. Advanced in Biophysics. IISc Young Science. Fellowship Programme. Inside Back Cover. Flowering Trees. (Credit: K Sankara Rao,IISc,. Bangalore). 97. 83. Classics. REFLECTIONS. 71 Integrative Microbiology – The Third Golden Age. Moselio Schaechter.

  6. RESONANCE

    Indian Academy of Sciences (India)

    Analysis of Results: a) By looking at the Fp one can say that the gene (s) for the normal grey body colour is dominant over the allele for the ebony colour (Law of Dominance of Mendel). b) The FI data do not tell us whether this body colour phenotype is due to one or more genes_ Therefore one has to look at the F2 progeny_.

  7. RESONANCE

    Indian Academy of Sciences (India)

    Three.J ... Infinity. In the section dealing with complex numbers, we find the following quotation from Euler's book on algebra: "All such expressions (-1 )1/2 , (_2)112 as etc. are impossible or imaginary numbers, since they represent roots of negative quantities, and of such numbers we may truly assert that they are nei ther ...

  8. Resonance

    Indian Academy of Sciences (India)

    IAS Admin

    International subscriptions are processed by Springer (www.springer.com). For details contact: Springer Distribution Centre GmbH, Customer Service Journals. Haberstrasse 7, D-69126 Heidelberg, Germany. The Americas (North, South, Central and the Caribbean): journals-ny@springer.com. Outside the Americas: ...

  9. RESONANCE

    Indian Academy of Sciences (India)

    He compiled his ideas on quantum mechanics into a textbook. Principles of Quantum Mechanics, which remains a classic to this day. As Kragh writes,. Dirac's book was the only pre-1957 book on quantum mechanics that did not assume parity conservation in physical laws. It was only in 1957 that the weak force was shown.

  10. Resonance

    Indian Academy of Sciences (India)

    IAS Admin

    : The Circulation Department, Indian Academy of Sciences,. C V Raman Avenue, P. B. No. 8005, Bangalore 560 080, India. Online orders for India are also accepted by Scholars without Borders (www.swb.co.in). Email:hello@swb.co.in.

  11. RESONANCE

    Indian Academy of Sciences (India)

    ally ser.ved traditional Tamil food on plan- tain leaves and requested to squat on the tioor alld eat Ilsillg bare hands! Pillai had strong beliefs with regard to pnblic issues: he was highly critical of the first 1lse of the atomic bomb and espoused quitting the. Commonwealth while retailling the Ellglish language. He is said to ...

  12. Resonance

    Indian Academy of Sciences (India)

    Age-specific mortality rate (8) 67 (RN). Albert Einstein - The man behind the myths by. John Stachel (8) 76 (RF). Algebra (1) 8 (SA). Algebra in ancient and modern times by. V S Varadarajan (6) 80 (BR). Algebraic integers (7) 28 (GA). Algebraic number theory (7) 28 (GA). Algorithmic complexities (4) 72 (GA). Almost complex ...

  13. Resonant primordial gravitational waves amplification

    Directory of Open Access Journals (Sweden)

    Chunshan Lin

    2016-01-01

    Full Text Available We propose a mechanism to evade the Lyth bound in models of inflation. We minimally extend the conventional single-field inflation model in general relativity (GR to a theory with non-vanishing graviton mass in the very early universe. The modification primarily affects the tensor perturbation, while the scalar and vector perturbations are the same as the ones in GR with a single scalar field at least at the level of linear perturbation theory. During the reheating stage, the graviton mass oscillates coherently and leads to resonant amplification of the primordial tensor perturbation. After reheating the graviton mass vanishes and we recover GR.

  14. 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.

  15. Micro-optomechanical trampoline resonators

    Science.gov (United States)

    Pepper, Brian; Kleckner, Dustin; Sonin, Petro; Jeffrey, Evan; Bouwmeester, Dirk

    2011-03-01

    Recently, micro-optomechanical devices have been proposed for implementation of experiments ranging from non-demolition measurements of phonon number to creation of macroscopic quantum superpositions. All have strenuous requirements on optical finesse, mechanical quality factor, and temperature. We present a set of devices composed of dielectric mirrors on Si 3 N4 trampoline resonators. We describe the fabrication process and present data on finesse and quality factor. The authors gratefully acknowledge support from NSF PHY-0804177 and Marie Curie EXT-CT-2006-042580.

  16. SHARE: Statistical hadronization with resonances

    Science.gov (United States)

    Torrieri, G.; Steinke, S.; Broniowski, W.; Florkowski, W.; Letessier, J.; Rafelski, J.

    2005-05-01

    SHARE is a collection of programs designed for the statistical analysis of particle production in relativistic heavy-ion collisions. With the physical input of intensive statistical parameters, it generates the ratios of particle abundances. The program includes cascade decays of all confirmed resonances from the Particle Data Tables. The complete treatment of these resonances has been known to be a crucial factor behind the success of the statistical approach. An optional feature implemented is the Breit-Wigner distribution for strong resonances. An interface for fitting the parameters of the model to the experimental data is provided. Program summaryTitle of the program:SHARE, October 2004, version 1.2 Catalogue identifier: ADVD Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADVD Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Computer: PC, Pentium III, 512 MB RAM (not hardware dependent) Operating system: Linux: RedHat 6.1, 7.2, FEDORA, etc. (not system dependent) Programming language:FORTRAN77: g77, f77 as well as Mathematica, ver. 4 or 5, for the case of full chemical equilibrium and particle widths set to zero Size of the package: 645 KB directory including example programs (87 KB compressed distribution archive) External routines: KERNLIB, MATHLIB and PACKLIB from the CERN Program Library (see http://cernlib.web.cern.ch for download and installation instructions) Distribution format: tar.gz Number of lines in distributed program, including test data, etc.: 15 277 Number of bytes in distributed program, including test data, etc.: 88 522 Computer: Any computer with an f77 compiler Nature of the physical problem: Statistical analysis of particle production in relativistic heavy-ion collisions involves the formation and the subsequent decays of a large number of resonances. With the physical input of thermal parameters, such as the temperature and fugacities, and considering cascading decays, along with weak

  17. Advances in magnetic resonance 3

    CERN Document Server

    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

  18. [Use of magnetic resonance imaging].

    Science.gov (United States)

    Chabanova, Elizaveta; Larsen, Lone; Løgager, Vibeke Berg; Møller, Jakob M; Thomsen, Henrik S

    2014-01-06

    Magnetic resonance imaging (MRI) is one of the four imaging modalities used in radiology. In contrast to computed tomography (CT), it does not use radiation. MRI is still developing and the diagnostic capabilities are growing. There are many indications for MRI and in some fields it has replaced CT. With few exceptions MRI is used mainly for elective examinations, and because of the new techniques like diffusion and perfusion MRI in cancer imaging the use is increasing both with regard to work-up and follow-up. For non-malignant lesions MRI is increasingly used thanks to its great soft-tissue contrast capabilities.

  19. Nanofiber-segment ring resonator

    CERN Document Server

    Jones, D E; Franson, J D; Pittman, T B

    2016-01-01

    We describe a fiber ring resonator comprised of a relatively long loop of standard single-mode fiber with a short nanofiber segment. The evanescent mode of the nanofiber segment allows the cavity-enhanced field to interact with atoms in close proximity to the nanofiber surface. We report on an experiment using a warm atomic vapor and low-finesse cavity, and briefly discuss the potential for reaching the strong coupling regime of cavity QED by using trapped atoms and a high-finesse cavity of this kind.

  20. 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.

  1. Tunable Fano and coupled-resonator-induced transparency resonances in the waveguide-coupled inverted nested ring resonator

    Science.gov (United States)

    Yu, Changqiu; Tian, He; Qian, Zhenghong; Bai, Ru; Zhu, Liyao; Zhang, Yundong

    2017-12-01

    A waveguide-coupled inverted nested ring resonator structure is proposed and theoretically investigated. The effects of the parameters of such a structure on its transmission properties are demonstrated. Results show that both Fano resonance and coupled-resonator-induced transparency (CRIT) spectra can be produced within this structure, depending on the length ratio of the feedback waveguide and ring. In addition, the slope of the Fano resonance can be tuned and reversed by varying coupling coefficients and effective refractive index. Besides, CRIT-based tunable group delay can be obtained with high transmittance. Therefore, this structure has potential applications in optical sensors and optical communication.

  2. Single-Molecule Stochastic Resonance

    Directory of Open Access Journals (Sweden)

    K. Hayashi

    2012-08-01

    Full Text Available 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 (random or probabilistic noise. Here we carry out the first experimental study of SR in single DNA hairpins which exhibit cooperatively transitions from folded to unfolded configurations under the action of an oscillating mechanical force applied with optical tweezers. By varying the frequency of the force oscillation, we investigate the folding and unfolding kinetics of DNA hairpins in a periodically driven bistable free-energy potential. We measure 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 a good quantifier of the SR is the signal-to-noise ratio (SNR of the spectral density of measured fluctuations in molecular extension of the DNA hairpins. The frequency dependence of the SNR exhibits a peak at a frequency value given by the resonance-matching condition. Finally, we carry out experiments on short hairpins that show how SR might be useful for enhancing the detection of conformational molecular transitions of low SNR.

  3. Resonance ionization spectroscopy in dysprosium

    Energy Technology Data Exchange (ETDEWEB)

    Studer, D., E-mail: dstuder@uni-mainz.de; Dyrauf, P.; Naubereit, P.; Heinke, R.; Wendt, K. [Johannes Gutenberg-Universität Mainz, Institut für Physik (Germany)

    2017-11-15

    We report on resonance ionization spectroscopy (RIS) of high-lying energy levels in dysprosium. We developed efficient excitation schemes and re-determined the first ionization potential (IP) via analysis of Rydberg convergences. For this purpose both two- and three-step excitation ladders were investigated. An overall ionization efficiency of 25(4) % could be demonstrated in the RISIKO mass separator of Mainz University, using a three-step resonance ionization scheme. Moreover, an extensive analysis of the even-parity 6sns- and 6snd-Rydberg-series convergences, measured via two-step excitation was performed. To account for strong perturbations in the observed s-series, the approach of multichannel quantum defect theory (MQDT) was applied. Considering all individual series limits we extracted an IP-value of 47901.76(5) cm{sup −1}, which agrees with the current literature value of 47901.7(6) cm{sup −1}, but is one order of magnitude more precise.

  4. Engineering resonances in infrared metamaterials.

    Science.gov (United States)

    Kanté, Boubacar; de Lustrac, André; Lourtioz, Jean-Michel; Gadot, Frédérique

    2008-05-12

    Engineering resonances in metamaterials has been so far the main way of reaching simultaneously negative permittivity and negative permeability leading to negative index materials. In this paper, we present an experimental and numerical analysis of the infrared response of metamaterials made of continuous nanowires and split ring resonators (SRR) deposited on low-doped silicon when the geometry of the SRRs is gradually altered. The impact of the geometric transformation of the SRRs on the spectra of the composite metamaterial is measured in the 20-200 THz frequency range (i.e., in the 1.5-15 microm wavelength range) for the two field polarizations under normal to plane propagation. We show experimentally and numerically that tuning the SRRs towards elementary cut wires translates in a predictable manner the frequency response of the artificial material. We also analyze coupling effects between the SRRs and the continuous nanowires for different spacings between them. The results of our study are expected to provide useful guidelines for the design of negative index metamaterials on silicon.

  5. Migraine and magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Younis, Samaira; Hougaard, Anders; Vestergaard, Mark B.

    2017-01-01

    Purpose of review: To present an updated and streamlined overview of the metabolic and biochemical aspect of the migraine pathophysiology based on findings from phosphorous (31P) and hydrogen (1H) magnetic resonance spectroscopy (MRS) studies. Recent findings: Despite of the variation in the meth......Purpose of review: To present an updated and streamlined overview of the metabolic and biochemical aspect of the migraine pathophysiology based on findings from phosphorous (31P) and hydrogen (1H) magnetic resonance spectroscopy (MRS) studies. Recent findings: Despite of the variation...... in the methodology and quality of the MRS migraine studies over time, some results were consistent and reproducible. 31P-MRS studies suggested reduced availability of neuronal energy and implied a mitochondrial dysfunction in the migraine brain. 1H-MRS studies reported interictal abnormalities in the excitatory...... and inhibitory neurotransmitters, glutamate and g-aminobutyric acid (GABA), suggesting persistent altered excitability in migraine patients. N-Acetylaspartate levels were decreased in migraine, probably due to a mitochondrial dysfunction and abnormal energy metabolism. The reported abnormalities may increase...

  6. Threshold enhancement of diphoton resonances

    CERN Document Server

    Bharucha, Aoife; Goudelis, Andreas

    2016-10-10

    The data collected by the LHC collaborations at an energy of 13 TeV indicates the presence of an excess in the diphoton spectrum that would correspond to a resonance of a 750 GeV mass. The apparently large production cross section is nevertheless very difficult to explain in minimal models. We consider the possibility that the resonance is a pseudoscalar boson $A$ with a two--photon decay mediated by a charged and uncolored fermion having a mass at the $\\frac12 M_A$ threshold and a very small decay width, $\\ll 1$ MeV; one can then generate a large enhancement of the $A\\gamma\\gamma$ amplitude which explains the excess without invoking a large multiplicity of particles propagating in the loop, large electric charges and/or very strong Yukawa couplings. 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...

  7. 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.

  8. 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.

  9. 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

  10. Resonance ionization scheme development for europium

    CERN Document Server

    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.

  11. Tuned driving of piezoelectric resonators: impedance matching

    OpenAIRE

    Pons, J. L.; Fernández, J .F.; Villegas, M.; Ochoa, P; Ceres, R.; L. Calderón; E. Rocon

    2006-01-01

    For optimal operation of piezoelectric resonators, the electrical impedance of electronic drivers and the resonator itself must be matched. Lack of matching results in a non smooth transmission of electrical power between the drive and the load which, in turn, leads to heating and poor efficiency. The rest of properties of the driving voltage (frequency, amplitude and phase) are also affected by this mismatch. This paper presents the optimal design of power drivers for piezoelectric resonator...

  12. Resonance ionization scheme development for europium

    Energy Technology Data Exchange (ETDEWEB)

    Chrysalidis, K., E-mail: katerina.chrysalidis@cern.ch; Goodacre, T. Day; Fedosseev, V. N.; Marsh, B. A. [CERN (Switzerland); Naubereit, P. [Johannes Gutenberg-Universität, Institiut für Physik (Germany); Rothe, S.; Seiffert, C. [CERN (Switzerland); Kron, T.; Wendt, K. [Johannes Gutenberg-Universität, Institiut für Physik (Germany)

    2017-11-15

    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.

  13. Resonant vibration control of rotating beams

    DEFF Research Database (Denmark)

    Svendsen, Martin Nymann; Krenk, Steen; Høgsberg, Jan Becker

    2011-01-01

    Rotatingstructures,like e.g.wind turbine blades, may be prone to vibrations associated with particular modes of vibration. It is demonstrated, how this type of vibrations can be reduced by using a collocated sensor–actuator system, governed by a resonant controller. The theory is here demonstrated...... modal connectivity, only very limited modal spill-over is generated. The controller acts by resonance and therefore has only a moderate energy consumption, and successfully reduces modal vibrations at the resonance frequency....

  14. Resonances in odd-odd 182Ta

    OpenAIRE

    Brits C.P.; Wiedeking M.; Bello Garrote F. L.; Bleuel D. L.; Giacoppo F.; Görgen A.; Guttormsen M.; Hadynska-Klek K.; Hagen T.W.; Ingeberg V.W.; Kheswa B.V.; Klintefjord M.; Larsen A.C.; Malatji K.L.; Nyhus H. T.

    2017-01-01

    Enhanced γ-decay on the tail of the giant electric dipole resonance, such as the scissors or pygmy resonances, can have significant impact on (n,γ) reaction rates. These rates are important input for modeling processes that take place in astrophysical environments and nuclear reactors. Recent results from the University of Oslo indicate the existence of a significant enhancement in the photon strength function for nuclei in the actinide region due to the scissors resonance. Further, the M1 st...

  15. Fano resonances in planar silver nanosphere clusters

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Kui; Nordlander, Peter [Rice Quantum Institute, Laboratory for Nanophotonics, Houston (United States); Rice University, Department of Physics, Houston, TX (United States); Mirin, Nikolay A. [Rice Quantum Institute, Laboratory for Nanophotonics, Houston (United States); Rice University, Department of Chemistry, Houston, TX (United States)

    2010-08-15

    The plasmonic properties of silver nanosphere clusters are investigated using the finite element and the plasmon hybridization methods. The nanoparticle clusters are found to exhibit multiple plasmon resonances with large induced electromagnetic field enhancements. For symmetric clusters, we show how group theory can be used to identify the microscopic nature of the plasmon resonances. For larger clusters, we show that narrow Fano resonances are frequently present in their optical spectra. (orig.)

  16. 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...... resonance and a resistor to dissipate the correct amount of vibration energy. The modal interaction with residual vibration forms not targeted by the resonant shunt is represented by supplemental flexibility and inertia terms. This leads to modified calibration formulae that maintain the desired damping...

  17. 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.

  18. Analysis of Alternative Ring Resonator Designs

    Science.gov (United States)

    2014-08-01

    also change the current path in the soil possibly introducing small inductances or capacitances into the resonator antenna system. Since Q of a circuit... inductance , L, and capacitance , C, of the effective ring resonator circuit could then change its resonance and therefore the result of the measurement...as radar waves are reflected from soil and penetrate into it. In particular, knowledge of these properties is critical for detection and location of

  19. 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...... depending on the split-ring resonator design and engineering of the light-plasmon coupling. This highest measured value is comparable to quasi-static predictions, suggesting incremental improvements beyond this point. Further optimization attempts show the effect of inhomogeneous broadening giving some...

  20. Coherence of magnetic resonators in a metamaterial

    Directory of Open Access Journals (Sweden)

    Yumin Hou

    2013-12-01

    Full Text Available The coherence of periodic magnetic resonators (MRs under oblique incidence is studied using simulations. The correlated phase of interaction including both the retardation effect and relative phase difference between two MRs is defined, and it plays a key role in the MR interaction. The correlated phase is anisotropic, as is the coherence condition. The coherence condition is the same as the Wood's anomaly and verified by the Fano resonance. This study shows that the applications of the Fano resonance of periodic MRs will become widespread owing to achieving the Fano resonance simply by tuning the incident angle.

  1. Photon decay of giant multipole resonances

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-01-01

    A brief review of the excitation of giant multipole resonances via Coulomb excitation is given which emphasizes the very large cross sections that can be realized through this reaction for both isoscalar and isovector resonances. Discussion and results where available, are provided for the measurement of the photon decay of one and two phonon giant resonances. It is pointed out throughout the presentation that the use of E1 photons as a tag'' provides a means to observe weakly excited resonances that cannot be observed in the shingles spectra. 26 refs., 16 figs., 1 tab.

  2. Quantum communication between remote mechanical resonators

    Science.gov (United States)

    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.

  3. Improvements in Mechanical Detection of Magnetic Resonance

    National Research Council Canada - National Science Library

    Fainchtein, Raul

    2005-01-01

    This program intended to provide substantial improvements to conditions that affect imaging nanoscale structures with atomic resolution and chemical specificity by magnetic resonance force microscopy...

  4. Under-Coupling Whispering Gallery Mode Resonator Applied to Resonant Micro-Optic Gyroscope.

    Science.gov (United States)

    Qian, Kun; Tang, Jun; Guo, Hao; Liu, Wenyao; Liu, Jun; Xue, Chenyang; Zheng, Yongqiu; Zhang, Chengfei

    2017-01-06

    As an important sensing element, the whispering gallery mode resonator (WGMR) parameters seriously affect the resonant micro-optic gyroscope (RMOG) performance. This work proposes an under-coupling resonator to improve the resonator's Q value and to optimize the coupling coefficient to maximize the RMOG's sensitivity. GeO₂-doped silica waveguide-type resonators with different coupling coefficients were simulated, designed, fabricated and tested. An under-coupling ring resonator with a quality factor of 10 million is reported. The RMOG system was built based on this resonator and the scale factor was tested on a uniaxial high-precision rotating platform. Experimental results show that this resonator could improve the RMOG sensitivity by five times.

  5. Quasi-resonant converter with divided resonant capacitor on primary and secondary side

    OpenAIRE

    Shiroyama, Hironobu; Matsuo, Hirofumi; Ishizuka, Yoichi

    2009-01-01

    This paper presents a quasi-resonant converter with divided resonant capacitor on primary and secondary side of the isolation transformer. A conventional quasi-resonant converter using flyback topology can realize soft switching with simple circuit. However, relatively large surge voltage is generated in the switching device. To suppress such surge voltage, resonant capacitor is divided on primary side and secondary side in the proposed converter. In case of prototype 95W converter, the volta...

  6. Fabrication and Characterization of Superconductive Coplanar Waveguide Resonators : Fabrication and Characterization of Superconductive Coplanar Waveguide Resonators

    OpenAIRE

    Ergül, Adem

    2009-01-01

    The objective of this thesis is to evaluate a generic process for fabrication and characterization of the Superconductive coplanar waveguide (CPW) resonators. Superconductive CPW resonators with various lengths and shapes are designed to investigate their electrical and magnetic properties as well as resonance properties and sensitivities. In the first part of thesis, two different models are introduced in order to estimate the nonlinear kinetic inductance of a superconducting CPW resonator. ...

  7. A New Look at an Old Activity: Resonance Tubes Used to Teach Resonance

    Science.gov (United States)

    Nelson, Jim; Nelson, Jane

    2017-01-01

    There are several variations of resonance laboratory activities used to determine the speed of sound. This is "not" one of them. This activity uses the resonance tube idea to teach "resonance," not to verify the speed of sound. Prior to this activity, the speed of sound has already been measured using computer sound-sensors and…

  8. One-loop renormalization of Resonance Chiral Theory: scalar and pseudoscalar resonances

    Energy Technology Data Exchange (ETDEWEB)

    Rosell, Ignasi [Departament de FIsica Teorica, IFIC, CSIC - Universitat de Valencia, Edifici d' Instituts de Paterna, Apt. Correus 22085, E-46071 Valencia (Spain); Ruiz-FemenIa, Pedro [Theory Division, Max-Planck-Institut fuer Physik, Foehringer Ring 6, D-80805 Munich (Germany); Portoles, Jorge [Departament de FIsica Teorica, IFIC, CSIC - Universitat de Valencia, Edifici d' Instituts de Paterna, Apt. Correus 22085, E-46071 Valencia (Spain)

    2005-12-15

    We consider the Resonance Chiral Theory with one multiplet of scalar and pseudoscalar resonances, up to bilinear couplings in the resonance fields, and evaluate its {beta}-function at one-loop with the use of the background field method. Thus we also provide the full set of operators that renormalize the theory at one loop and render it finite.

  9. The resonance energy of benzene: a revisit.

    Science.gov (United States)

    Mo, Yirong

    2009-04-30

    Zielinski and van Lenthe recently extended the block-localized wave function (BLW) method by introducing the resonating BLW (RBLW) method and performed test calculations on hexagonal H(6) and benzene [J. Phys. Chem. A 2008, 112, 13197]. However, the Pauling's resonance energies from their RBLW and ab initio valence bond (VB) calculations were greatly underestimated largely due to the imperfect use of either one-electron orbitals (method = delocal) or resonance structures (method = local). Whereas it has been well recognized that electronic resonance within a molecular system plays a stabilizing role, there are many indirect experimental evidences available to evaluate the resonance energy and, thus, to justify computational results. Here we used the BLW method, which can be regarded as the simplest variant of modern ab initio VB theory, to re-evaluate the resonance energy of benzene at the B3LYP level, following the original definition by Pauling and Wheland, who obtained the resonance energy "by subtracting the actual energy of the molecule in question from that of the most stable contributing structure". The computed vertical resonance energy (or quantum mechanical resonance energy) in benzene is 88.8, 92.2, or 87.9 kcal/mol with the basis sets of 6-31G(d), 6-311+G(d,p), or cc-pVTZ, respectively, while the adiabatic resonance energy (or theoretical resonance energy) is 61.4, 63.2, or 62.4 kcal/mol, exhibiting insignificant basis set dependency for moderate basis sets. In line with predictions, the geometry optimization of the elusive cyclohexatriene (i.e., the Kekule structure) with the BLW method also resulted in carbon-carbon bond lengths (e.g., 1.322 and 1.523 A with the cc-pVTZ basis set) comparable to those in ethylene or ethane.

  10. The analytical basis for the resonances and anti-resonances of loop antennas and meta-material ring resonators

    Science.gov (United States)

    McKinley, A. F.; White, T. P.; Maksymov, I. S.; Catchpole, K. R.

    2012-11-01

    Interest in the electromagnetic properties of loop structures has surged with the recent appearance of split-ring resonator meta-materials (SRRs) and nano-antennas. Understanding the resonances, anti-resonances, and harmonics of these loops is key to understanding their response to a wide range of excitation wavelengths. We present the classical analytical solution for the input impedance of a loop structure with circumference on the order of the wavelength, and we show how to identify these resonances from the function. We transform the classical solution into a new RLC formulation and show that each natural mode of the loop can be represented as a series resonant circuit, such that the full response function can be resolved by placing all of these circuits in parallel. We show how this formulation applies to SRRs.

  11. Resonant ion transport in EBT

    Energy Technology Data Exchange (ETDEWEB)

    Hastings, D.E.; Jaeger, E.F.; Hedrick, C.L.; Tolliver, J.S.

    1983-05-01

    We use a model for the ELMO Bumpy Torus as a bumpy cylinder with a toroidally induced vertical drift imposed on the plasma. With this model we obtain the neoclassical plasma-transport coefficients for ions in both the banana and plateau resonant regimes. The problem of solving the linearized bounce-averaged drift kinetic equation is formulated as a variational principle, which is shown to be valid for both the banana and plateau regimes. We use limiting forms of this principle to obtain a continuous collisionality approximation to the energy-dependent flux. We then use this approximation to obtain analytic formulae for the particle- and energy-diffusion coefficients. These are shown to give excellent agreement with numerical results.

  12. Piezoelectric Resonator with Two Layers

    Science.gov (United States)

    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.

  13. Magnetic Resonance Imaging of Electrolysis.

    Science.gov (United States)

    Meir, Arie; Hjouj, Mohammad; Rubinsky, Liel; Rubinsky, Boris

    2015-01-01

    This study explores the hypothesis that Magnetic Resonance Imaging (MRI) can image the process of electrolysis by detecting pH fronts. The study has relevance to real time control of cell ablation with electrolysis. To investigate the hypothesis we compare the following MR imaging sequences: T1 weighted, T2 weighted and Proton Density (PD), with optical images acquired using pH-sensitive dyes embedded in a physiological saline agar solution phantom treated with electrolysis and discrete measurements with a pH microprobe. We further demonstrate the biological relevance of our work using a bacterial E. Coli model, grown on the phantom. The results demonstrate the ability of MRI to image electrolysis produced pH changes in a physiological saline phantom and show that these changes correlate with cell death in the E. Coli model grown on the phantom. The results are promising and invite further experimental research. PMID:25659942

  14. Resonant structures for infrared detection.

    Science.gov (United States)

    Choi, K K; Allen, S C; Sun, J G; Wei, Y; Olver, K A; Fu, R X

    2017-01-20

    We are developing resonator-quantum well infrared photodetectors (R-QWIPs) for long-wavelength applications. Detector pixels with 25 μm pitch were hybridized to fan-out circuits for radiometric measurements. With a moderate doping of 0.5×1018  cm-3, we achieved a quantum efficiency (QE) of 37% and conversion efficiency (CE) of 15% in a 1.3 μm thick active material and 35% QE and 21% CE in a 0.6 μm thick active material. Both detectors are cutoff at 10.5 μm with a 2 μm bandwidth. The temperature at which photocurrent equals dark current is about 65 K under F/2 optics. The thicker detector shows a large QE polarity asymmetry due to nonlinear potential drop in the QWIP material layers.

  15. Astrophysically Interesting Resonances; Another Approach

    Science.gov (United States)

    Austin, Roby; Jenkins, David

    2008-10-01

    R.A.E. Austin, R. Kanungo, A. Campbell, S. Colosimo, S. Reeve Saint Mary's University; D.G. Jenkins, C.Aa.Diget, A. Robinson, University of York, UK; P.J. Woods T. Davinson University of Edinburgh; C.-Y. Wu A. Hurst J.A. Becker Lawrence Livermore National Laboratory; G.C. Ball M. Djongolov G. Hackman A.C. Morton, C. Pearson, S.J. Williams TRIUMF; A.A. Phillips, M. Schumaker, University of Guelph H.Boston, A. Grint, D. Oxley, University of Liverpool; D. Cline, A. Hayes, University of Rochester; We describe a prototype experiment to measure resonances of interest in astrophysical reactions. We use the TIGRESS to detect gamma rays in coincidence with charged particles, inelastically scattered in inverse kinematics. The particles are detected with the Bambino detector modified to a δE-E silicon telescope spanning 15-40 degrees in the lab.

  16. ELECTRON PARAMAGNETIC RESONANCE IN BIOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    Androes, G.M.; Calvin, Melvin.

    1961-08-15

    A review of the theories of electron paramagnetic resonance in biology is presented, including a discussion of the nature of the physical observation, followed by examples of materials of biological interest. Iq discussing these examples, information is presented in terms of the nature of the starting material under observation rather than the nature of the magnetic entities observed. The examples proceed from the simpler molecules of biological interest (metabolites, vitamins, cofactors) into the more complex materials (polymers, proteins, nucleic acids) toward cellular organelles (mitochondria, chloroplasts) and, finally, to whole cells, organisms and organs. The observation of photoinduced unpaired electrons in photosynthetic material is described and the various parameters controlling it are discussed. The basic observation is interpreted in terms of a primary photophysical act of quantum conversion.

  17. Resonant magnetic fields from inflation

    CERN Document Server

    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.

  18. Protein folding and wring resonances

    DEFF Research Database (Denmark)

    Bohr, Jakob; Bohr, Henrik; Brunak, Søren

    1997-01-01

    The polypeptide chain of a protein is shown to obey topological contraints which enable long range excitations in the form of wring modes of the protein backbone. Wring modes of proteins of specific lengths can therefore resonate with molecular modes present in the cell. It is suggested...... that protein folding takes place when the amplitude of a wring excitation becomes so large that it is energetically favorable to bend the protein backbone. The condition under which such structural transformations can occur is found, and it is shown that both cold and hot denaturation (the unfolding...... of proteins) are natural consequences of the suggested wring mode model. Native (folded) proteins are found to possess an intrinsic standing wring mode....

  19. Magnetic Resonance Imaging of Neurosarcoidosis

    Directory of Open Access Journals (Sweden)

    Daniel T Ginat

    2011-01-01

    Full Text Available Neurosarcoidosis is an uncommon condition with protean manifestations. Magnetic resonance imaging (MRI is often used in the diagnostic evaluation and follow-up of patients with neurosarcoidosis. Therefore, familiarity with the variety of MRI appearances is important. In this pictorial essay, the range of possible patterns of involvement in neurosarcoidosis are depicted and discussed. These include intracranial and spine leptomeningeal involvement, cortical and cerebral white matter lesions, corpus callosum involvement, sellar and suprasellar involvement, periventricular involvement, cranial nerve involvement, cavernous sinus involvement, hydrocephalus, dural involvement, ischemic lesions, perivascular involvement, orbit lesions, osseous involvement, nerve root involvement, and spinal cord intramedullary involvement. Differential diagnoses for each pattern of involvement of neurosarcoidosis are also provided.

  20. Classical and Quantum Stochastic Resonance

    Science.gov (United States)

    Hänggi, Peter

    1996-03-01

    The idea that noise can assist the formation of order might sound paradoxical but does indeed occur in nonlinear systems with the phenomenon of Stochastic Resonance (SR)(F. Moss et al., Stochastic Resonance: Tutorial and Update), Int. J. Bif. and Chaos 4, 1383 (1994); K. Wiesenfeld and F. Moss, Nature 373, 33 (1995); P. Jung, Phys. Rep. 234 C, 175 (1993). This term is given to the effect where the detection of weak periodic signals is enhanced in presence of noise activated crossings of barriers or threshold levels. After introducing the audience into the common characterization of SR by use of the power spectrum of the output signal and/or the probability density of correponding residence times, I shall report new features for nonlinear SR where strong driving can give rise to anomalous amplification of higher harmonics, hole-burning in power spectra, or SR-induced, almost complete deletion of higher harmonics(R. Bartussek, P. Jung, P. Hänggi, Phys. Rev. E49), 3930 (1994); V. Shneidman, P. Jung, P. Hänggi, Phys. Rev. Lett. 72, 2682 (1994). These novel effects have recently been confirmed experimentally in a magnetic flux driven sensitive detection device (superconducting quantum-interference device)(R. Rouse, S. Han, J.E. Lukens, Appl. Phys. Lett. 66), 108 (1995). This device constitutes a macroscopic quantum system where with decreasing temperature quantum tunneling transitions begin to modify and blur the classical SR-responce. Recent progress in the quest of SR phenomena in the deep quantum regime(M. Grifoni and P. Hänggi, submitted to PRL) is reviewed together with experimental proposals where Quantum-SR induced manipulation of individual atoms, or whole molecular groups, can be observed.

  1. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... Sponsored by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography (MRA) Transcript Welcome to Radiology Info ... I’d like to talk with you about magnetic resonance angiography, or as it’s commonly known, MRA. ...

  2. Single voxel magnetic resonance spectroscopy in distinguishing ...

    African Journals Online (AJOL)

    Objective: Assess diagnostic utility of combined magnetic resonance imaging and magnetic resonance spectroscopy (MRI, MRS) in differentiating focal neoplastic lesions from focal non- neoplastic (infective or degenerative) brain lesions. Design: Descriptive, analytical - prospective study. Setting: The Aga Khan University ...

  3. Intraoperative magnetic resonance imaging and meningioma surgery

    African Journals Online (AJOL)

    Objective: To determine if intraoperative magnetic resonance imaging improves surgical resection and postoperative outcome of intracranial meningioma. Study design: Prospective, non-randomized, cohort study. Method: Intraoperative Magnetic Resonance Imaging (iMRI) was used to evaluate patients with meningioma ...

  4. 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....

  5. 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....

  6. Resonant coherent excitation of channeled ions

    Energy Technology Data Exchange (ETDEWEB)

    Datz, S.; Moak, C.D.; Crawford, O.H.; Krause, H.F.; Dittner, P.F.; Gomez del Campo, J.; Biggerstaff, J.A.; Miller, P.D.; Hvelplund, P.; Knudsen, H.

    1978-03-27

    We have observed resonant excitation of swift channeled hydrogenlike ions (Z = 5 to Z = 9) and heliumlike F/sup 7 +/ which arises from a coherent periodic perturbation by the atoms in the bounding crystal rows. The resonance excitation was seen through the reduction in the transmission of fixed-charge-state ions through channels in thin crystals of Au and Ag.

  7. Resonance modeling and control via magnetorheological dampers

    Science.gov (United States)

    Letelier, Mario F.; Siginer, Dennis A.; Stockle, Juan S.

    2016-08-01

    A method to model and minimize resonant structural oscillations using magnetorheological dampers is presented. The response of the magnetorheological fluid flowing in a circular tube under a pressure gradient to the applied variable magnetic field is tailored to determine the optimum stress field in the fluid to mitigate resonance effects.

  8. ASCAP. Resonance Region Cross Section Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Smith, J.R.; Young, R.C. [EG and G Idaho Inc., Idaho Falls, ID (United States)

    1972-09-01

    ACSAP may be used to compute neutron cross section data from neutron resonance input. Total, fission, capture, or scattering cross section data may be computed. Experimental data may be compared by means of a wide selection of representations. ACSAP can also determine cross section resonance parameters from input experimental data.

  9. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... Sponsored by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography (MRA) Transcript Welcome to Radiology Info dot org ... I’d like to talk with you about magnetic resonance angiography, or as it’s commonly known, MRA. MRA is ...

  10. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Science.gov (United States)

    ... Sponsored by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography (MRA) Transcript Welcome to Radiology Info dot org ... I’d like to talk with you about magnetic resonance angiography, or as it’s commonly known, MRA. MRA is ...

  11. Higher-Order Resonances in Dynamical Systems

    NARCIS (Netherlands)

    Tuwankotta, J.M.

    2002-01-01

    This thesis is a collection of studies on higher-order resonances in an important class of dynamical systems called coupled oscillators systems. After giving an overview of the mathematical background, we start in Chapter 1 by presenting a study on resonances in two degrees of freedom, autonomous,

  12. Neutron Resonance Parameters for Pu-239 (Plutonium)

    Science.gov (United States)

    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 Pu-239 (Plutonium).

  13. 14 CFR 29.241 - Ground resonance.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground resonance. 29.241 Section 29.241 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... resonance. The rotorcraft may have no dangerous tendency to oscillate on the ground with the rotor turning...

  14. Josephson plasma resonance in superconducting multilayers

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig

    1999-01-01

    We derive an analytical solution for the josephson plasma resonance of superconducting multilayers. This analytical solution is derived mainly for low T-c systems with magnetic coupling between the superconducting layers, but many features of our results are more general, and thus an application...... to the recently derived plasma resonance phenomena for high T-c superconductors of the BSCCO type is discussed....

  15. 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...

  16. 14 CFR 27.241 - Ground resonance.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground resonance. 27.241 Section 27.241 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... resonance. The rotorcraft may have no dangerous tendency to oscillate on the ground with the rotor turning...

  17. Microwave power coupling with electron cyclotron resonance ...

    Indian Academy of Sciences (India)

    Electron cyclotron resonance (ECR) plasma was produced at 2.45 GHz using 200 – 750 W microwave power. The plasma was produced from argon gas at a pressure of 2 × 10−4 mbar. Three water-cooled solenoid coils were used to satisfy the ECR resonant conditions inside the plasma chamber. The basic parameters of ...

  18. Functional Magnetic Resonance Imaging and Pediatric Anxiety

    Science.gov (United States)

    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.…

  19. 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...

  20. Resonances in η-light nucleus systems

    Indian Academy of Sciences (India)

    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 ...

  1. Resonance propagation in heavy-ion scattering

    Indian Academy of Sciences (India)

    We also observe that, for not so heavy nuclear systems and/or for fast moving resonances, the shape, magnitude and peak position of the invariant mass distribution is substantially different if the contributions from the resonance decay inside and outside are summedup at the amplitude level (coherently) or at the cross ...

  2. Resonance propagation in heavy-ion scattering

    Indian Academy of Sciences (India)

    of about 120 MeV is required. We also observe that, for not so heavy nuclear systems and/or for fast moving resonances, the shape, magnitude and peak position of the invariant mass distribution is substantially different if the contributions from the resonance decay inside and outside are summed- up at the amplitude level ...

  3. Method for fabricating a microelectromechanical resonator

    Energy Technology Data Exchange (ETDEWEB)

    Wojciechowski, Kenneth E; Olsson, III, Roy H

    2013-02-05

    A method is disclosed which calculates dimensions for a MEM resonator in terms of integer multiples of a grid width G for reticles used to fabricate the resonator, including an actual sub-width L.sub.a=NG and an effective electrode width W.sub.e=MG where N and M are integers which minimize a frequency error f.sub.e=f.sub.d-f.sub.a between a desired resonant frequency f.sub.d and an actual resonant frequency f.sub.a. The method can also be used to calculate an overall width W.sub.o for the MEM resonator, and an effective electrode length L.sub.e which provides a desired motional impedance for the MEM resonator. The MEM resonator can then be fabricated using these values for L.sub.a, W.sub.e, W.sub.o and L.sub.e. The method can also be applied to a number j of MEM resonators formed on a common substrate.

  4. Control of resonances in photonic crystal waveguides

    NARCIS (Netherlands)

    Lian, Jin

    2016-01-01

    Photonic crystal waveguides (PhCWG) with intentional defects and unavoidable disorder exhibit high quality factor (Q) resonances. Single- and multi-resonance systems based on them are suitable for applications such as optical memories, delay lines and cavity QED. Therefore, characterization, control

  5. Periodic motions and resonances of impact oscillators

    Science.gov (United States)

    Dyskin, Arcady V.; Pasternak, Elena; Pelinovsky, Efim

    2012-06-01

    Bilinear oscillators - the oscillators whose springs have different stiffnesses in compression and tension - model a wide range of phenomena. A limiting case of bilinear oscillator with infinite stiffness in compression - the impact oscillator - is studied here. We investigate a special set of impact times - the eigenset, which corresponds to the solution of the homogeneous equation, i.e. the oscillator without the driving force. We found that this set and its subsets are stable with respect to variation of initial conditions. Furthermore, amongst all periodic sets of impact times with the period commensurate with the period of driving force, the eigenset is the only one which can support resonances, in particular the multi-'harmonic' resonances. Other resonances should produce non-periodic sets of impact times. This funding indicates that the usual simplifying assumption [e.g., S.W. Shaw, P.J. Holmes, A periodically forced piecewise linear oscillator, Journal of Sound and Vibration 90 (1983) 129-155] that the times between impacts are commensurate with the period of the driving force does not always hold. We showed that for the first sub-'harmonic resonance' - the resonance achieved on a half frequency of the main resonance - the set of impact times is asymptotically close to the eigenset. The envelope of the oscillations in this resonance increases as a square root of time, opposite to the linear increase characteristic of multi-'harmonic' resonances.

  6. Monitoring Subsurface Objects Using Resonant Seismic Emission

    Science.gov (United States)

    Konstantinov, V.; Korneev, V.

    2008-12-01

    The numerical modeling results and field data indicate that some contrast subsurface objects (such as tunnels, caves, pipes, filled pits, and fluid-filled fractures) are capable to trap seismic energy and generate durable resonant oscillations. These oscillations are comprised of surface types of circumferential waves which multiply rotate around the object. Resonant emission of such trapped energy occurs primarily in form of shear body waves that can be detected by remotely placed receivers. Resonant emission reveals itself in form of sharp resonant peaks for the late parts of the records, when all strong direct and primary reflected waves are gone. These peaks are observed in the field data for a buried barrel filled with water, in 2D finite- difference modeling results and in exact canonical solution for a fluid-filled sphere. Computed movie for diffraction of a plane wave upon low-velocity elastic sphere confirms generation of resonances by durable surface waves. We show that resonant emission has characteristic quasi-hyperbolic travel-time patterns on shot-gathers. Inversion of these patterns can be performed in frequency domain after muting strong direct and primary scattered waves. Subsurface objects can be detected and imaged at a single resonance frequency without an accurate knowledge about source trigger time. Imaging of subsurface objects requires information about shear velocity distribution in an embedding medium, which can be done interactively during inversion. Resonant emission data processing is done using KinetiK Professional visualization and processing software.

  7. Dynamic Resonance Sensitivity Analysis in Wind Farms

    DEFF Research Database (Denmark)

    Ebrahimzadeh, Esmaeil; Blaabjerg, Frede; Wang, Xiongfei

    2017-01-01

    Unlike conventional power systems, where resonance frequencies are mainly determined by passive impedances, wind farms present a more complex situation, where the control systems of the power electronic converters introduce also active impedances. This paper presents an approach to find...... the resonance frequencies of wind farms by considering both active and passive impedances and to identify which bus of the wind farm has more contribution to resonance frequencies. In the approach, a wind farm is introduced as a Multi-Input Multi-Output (MIMO) dynamic system and the bus Participation Factors...... (PFs) are calculated by critical eigenvalue sensitivity analysis versus the entries of the MIMO matrix. The PF analysis locates the most exciting bus of the resonances, where can be the best location to install the passive or active filters to reduce the harmonic resonance problems. Time...

  8. Tunable Magnetic Resonance in Microwave Spintronics Devices

    Science.gov (United States)

    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.

  9. Stochastic resonance in noisy threshold neurons.

    Science.gov (United States)

    Kosko, Bart; Mitaim, Sanya

    2003-01-01

    Stochastic resonance occurs when noise improves how a nonlinear system performs. This paper presents two general stochastic-resonance theorems for threshold neurons that process noisy Bernoulli input sequences. The performance measure is Shannon mutual information. The theorems show that small amounts of independent additive noise can increase the mutual information of threshold neurons if the neurons detect subthreshold signals. The first theorem shows that this stochastic-resonance effect holds for all finite-variance noise probability density functions that obey a simple mean constraint that the user can control. A corollary shows that this stochastic-resonance effect occurs for the important family of (right-sided) gamma noise. The second theorem shows that this effect holds for all infinite-variance noise types in the broad family of stable distributions. Stable bell curves can model extremely impulsive noise environments. So the second theorem shows that this stochastic-resonance effect is robust against violent fluctuations in the additive noise process.

  10. 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.

  11. Contour mode resonators with acoustic reflectors

    Science.gov (United States)

    Olsson, Roy H [Albuquerque, NM; Fleming, James G [Albuquerque, NM; Tuck, Melanie R [Albuquerque, NM

    2008-06-10

    A microelectromechanical (MEM) resonator is disclosed which has a linear or ring-shaped acoustic resonator suspended above a substrate by an acoustic reflector. The acoustic resonator can be formed with a piezoelectric material (e.g. aluminum nitride, zinc oxide or PZT), or using an electrostatically-actuated material. The acoustic reflector (also termed an acoustic mirror) uses alternating sections of a relatively low acoustic impedance Z.sub.L material and a relatively high acoustic impedance Z.sub.H material to isolate the acoustic resonator from the substrate. The MEM resonator, which can be formed on a silicon substrate with conventional CMOS circuitry, has applications for forming oscillators, rf filters, and acoustic sensors.

  12. Observations of Snake Resonance in RHIC

    CERN Document Server

    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.

  13. Linear spreading speeds from nonlinear resonant interaction

    Science.gov (United States)

    Faye, Grégory; Holzer, Matt; Scheel, Arnd

    2017-06-01

    We identify a new mechanism for propagation into unstable states in spatially extended systems, that is based on resonant interaction in the leading edge of invasion fronts. Such resonant invasion speeds can be determined solely based on the complex linear dispersion relation at the unstable equilibrium, but rely on the presence of a nonlinear term that facilitates the resonant coupling. We prove that these resonant speeds give the correct invasion speed in a simple example, we show that fronts with speeds slower than the resonant speed are unstable, and corroborate our speed criterion numerically in a variety of model equations, including a nonlocal scalar neural field model. GF received support from the project NONLOCAL (ANR-14-CE25-0013) funded by the French National Research Agency. MH was partially supported by the National Science Foundation through grant NSF-DMS-1516155. AS was partially supported by the National Science Foundation through grant NSF-DMS-1311740 and through a DAAD Fellowship.

  14. 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.

  15. Temperature dependence of resonance characteristics of silicon resonators and thermal stability improvement by differential operation method

    Science.gov (United States)

    Sana, Amrita Kumar; Jun, Maeda; Yokoyama, Shuhei; Amemiya, Yoshiteru; Yokoyama, Shin

    2017-04-01

    In this paper, we describe the mechanism and solution for dominating temperature effects on refractive-index-based Si optical resonator sensors such as ring resonator and photonic crystal resonator sensors. The temperature change affects the silicon refractive index and also the resonator mechanical shape. As a result, it is reported that the refractive index change is marked, whereas the mechanical deformation effect is negligible. We also demonstrated that the differential operation is effective for suppressing the temperature effect for Si ring resonator sensors.

  16. Membrane metamaterial resonators with a sharp resonance: A comprehensive study towards practical terahertz filters and sensors

    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.

  17. Coplanar photonic bandgap resonators for low temperature electron and nuclear magnetic resonance spectroscopy

    Science.gov (United States)

    Sigillito, A. J.; Tyryshkin, A. M.; Lyon, S. A.

    In recent years, superconducting coplanar waveguide (CPW) resonators have become a useful tool for low temperature pulsed electron spin resonance (ESR), even at dilution refrigerator temperatures. Their small mode volumes make CPW resonators particularly well suited to measuring small numbers of spins near the resonator surface, since in this region the spin sensitivity is very high. While these resonators have proven useful for ESR at single microwave frequencies, it is difficult to also manipulate nuclear spins in electron-nuclear-double resonance (ENDOR) experiments, since manipulation of nuclear spins requires radio frequency (RF) magnetic fields. Ideally one would simply generate these fields by passing RF currents through the CPW, but because conventional CPW resonators are capacitively coupled, they will not transmit low-frequency RF currents. In this talk, we discuss the use of one dimensional photonic bandgap (PBG) resonators to overcome this challenge. PBG resonators are a promising alternative to conventional CPW resonators since they offer high quality factors at microwave frequencies, while simultaneously allowing transmission of nonresonant RF currents below the photonic bandgap. Here, we will discuss PBG resonator designs and present data showing their use for low temperature ESR of donors in 28Si. Initial ENDOR results will also be presented.

  18. 3C-SiC microdisk mechanical resonators with multimode resonances at radio frequencies

    Science.gov (United States)

    Lee, Jaesung; Zamani, Hamidrera; Rajgopal, Srihari; Zorman, Christian A.; X-L Feng, Philip

    2017-07-01

    We report on the design, modeling, fabrication and measurement of single-crystal 3C-silicon carbide (SiC) microdisk mechanical resonators with multimode resonances operating at radio frequencies (RF). These microdisk resonators (center-clamped on a vertical stem pedestal) offer multiple flexural-mode resonances with frequencies dependent on both disk and anchor dimensions. The resonators are made using a novel fabrication method comprised of focused ion beam nanomachining and hydroflouic : nitric : acetic (HNA) acid etching. Resonance peaks (in the frequency spectrum) are detected through laser-interferometry measurements. Resonators with different dimensions are tested, and multimode resonances, mode splitting, energy dissipation (in the form of quality factor measurement) are investigated. Further, we demonstrate a feedback oscillator based on a passive 3C-SiC resonator. This investigation provides important guidelines for microdisk resonator development, ranging from an analytical prediction of frequency scaling law to fabrication, suggesting RF microdisk resonators can be good candidates for future sensing applications in harsh environments.

  19. Under-Coupling Whispering Gallery Mode Resonator Applied to Resonant Micro-Optic Gyroscope

    Directory of Open Access Journals (Sweden)

    Kun Qian

    2017-01-01

    Full Text Available As an important sensing element, the whispering gallery mode resonator (WGMR parameters seriously affect the resonant micro-optic gyroscope (RMOG performance. This work proposes an under-coupling resonator to improve the resonator’s Q value and to optimize the coupling coefficient to maximize the RMOG’s sensitivity. GeO2-doped silica waveguide-type resonators with different coupling coefficients were simulated, designed, fabricated and tested. An under-coupling ring resonator with a quality factor of 10 million is reported. The RMOG system was built based on this resonator and the scale factor was tested on a uniaxial high-precision rotating platform. Experimental results show that this resonator could improve the RMOG sensitivity by five times.

  20. Lateral acoustic wave resonator comprising a suspended membrane of low damping resonator material

    Science.gov (United States)

    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.

  1. Theory and Applications of Surface Plasmon Resonance, Resonant Mirror, Resonant Waveguide Grating, and Dual Polarization Interferometry Biosensors

    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.

  2. String resonances at hadron colliders

    Science.gov (United States)

    Anchordoqui, Luis A.; Antoniadis, Ignatios; Dai, De-Chang; Feng, Wan-Zhe; Goldberg, Haim; Huang, Xing; Lüst, Dieter; Stojkovic, Dejan; Taylor, Tomasz R.

    2014-09-01

    We consider extensions of the standard model based on open strings ending on D-branes, with gauge bosons due to strings attached to stacks of D-branes and chiral matter due to strings stretching between intersecting D-branes. Assuming that the fundamental string mass scale Ms 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 (integrated luminosity =3000 fb-1) with a center-of-mass energy of √s =14 TeV and at potential future pp colliders, HE-LHC and VLHC, operating at √s =33 and 100 TeV, respectively (with the same integrated luminosity). In such D-brane constructions, the dominant contributions to full-fledged string amplitudes for all the common QCD parton subprocesses leading to dijets and γ +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 excitations are open to discovery at the ≥5σ in dijet (γ +jet) HL-LHC data. We also show that for n=1 the dijet discovery potential at HE-LHC and VLHC exceedingly improves: up to 15 TeV and 41 TeV, respectively. To compute the signal-to-noise ratio for n=2 resonances, we first carry out a complete calculation of all relevant decay widths of the second massive level string states (including decays into massless particles and a massive n=1 and a massless particle), where we rely on factorization and conformal field theory techniques. Helicity wave functions of arbitrary higher spin massive bosons are also constructed. We demonstrate that for string scales Ms≲10.5 TeV (Ms≲28 TeV) detection of n =2 Regge recurrences at HE-LHC (VLHC) would become the smoking gun for D

  3. 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

  4. Design and characterization of a novel diamond resonator

    OpenAIRE

    Maricar, Mohamed Ismaeel; Glover, James; Evans, Gwynne; Khalid, Ata-ul-Habib; Cumming, David; Oxley, Chris

    2014-01-01

    In this article, the resonant frequency and quality factor of a novel coplanar waveguide (cpw) diamond-shaped resonator were analyzed using advanced design system-2009 momentum model software. The diamond resonator was compared with the cpw radial stub resonator on gallium arsenide (GaAs); the work indicated that the diamond resonator had a smaller physical size and higher quality factor (Q) at millimetric wave frequencies. Experimentally measured diamond cpw resonators fabricated on GaAs wer...

  5. Fano resonance Rabi splitting of surface plasmons.

    Science.gov (United States)

    Liu, Zhiguang; Li, Jiafang; Liu, Zhe; Li, Wuxia; Li, Junjie; Gu, Changzhi; Li, Zhi-Yuan

    2017-08-14

    Rabi splitting and Fano resonance are well-known physical phenomena in conventional quantum systems as atoms and quantum dots, arising from strong interaction between two quantum states. In recent years similar features have been observed in various nanophotonic and nanoplasmonic systems. Yet, realization of strong interaction between two or more Fano resonance states has not been accomplished either in quantum or in optical systems. Here we report the observation of Rabi splitting of two strongly coupled surface plasmon Fano resonance states in a three-dimensional plasmonic nanostructure consisting of vertical asymmetric split-ring resonators. The plasmonic system stably supports triple Fano resonance states and double Rabi splittings can occur between lower and upper pairs of the Fano resonance states. The experimental discovery agrees excellently with rigorous numerical simulations, and is well explained by an analytical three-oscillator model. The discovery of Fano resonance Rabi splitting could provide a stimulating insight to explore new fundamental physics in analogous atomic systems and could be used to significantly enhance light-matter interaction for optical sensing and detecting applications.

  6. 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.

  7. 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.

  8. Ultralow-Dissipation Superfluid Micromechanical Resonator

    Science.gov (United States)

    Souris, F.; Rojas, X.; Kim, P. H.; Davis, J. P.

    2017-04-01

    Micro- and nanomechanical resonators with ultralow dissipation have great potential as useful quantum resources. The superfluid micromechanical resonators presented here possess several advantageous characteristics: straightforward thermalization, dissipationless flow, and in situ tunability. We identify and quantitatively model the various dissipation mechanisms in two resonators, one fabricated from borosilicate glass and one from single-crystal quartz. As the resonators are cryogenically cooled into the superfluid state, the damping from thermal effects and from the normal-fluid component are strongly suppressed. At our lowest temperatures, damping is limited solely by internal dissipation in the substrate materials, and the resonators reach quality factors of up to 913 000 at 13 mK. By lifting this limitation through substrate-material choice and resonator design, modeling suggests that the resonators could reach quality factors as high as 108 at 100 mK, putting this architecture in an ideal position to harness mechanical quantum effects and to facilitate the study of superfluids in confined geometries.

  9. A delta configured auxiliary resonant snubber inverter

    Energy Technology Data Exchange (ETDEWEB)

    Lai, J.S.; Young, R.W.; Ott, G.W. Jr.; McKeever, J.W. [Oak Ridge National Lab., TN (United States). Engineering Technology Div.; Peng, F.Z. [Univ. of Tennessee, Knoxville, TN (United States)]|[Oak Ridge National Lab., TN (United States)

    1995-09-01

    A delta ({Delta}) configured auxiliary resonant snubber inverter is developed to overcome the voltage floating problem in a wye (Y) configured resonant snubber inverter. The proposed inverter is to connect auxiliary resonant branches between phase outputs to avoid a floating point voltage which may cause over-voltage failure of the auxiliary switches. Each auxiliary branch consists of a resonant inductor and a reverse blocking auxiliary switch. Instead of using an anti-paralleled diode to allow resonant current to flow in the reverse direction, as in the Y-configured version, the resonant branch in the {Delta}-configured version must block the negative voltage, typically done by a series diode. This paper shows single-phase and three-phase versions of {Delta}-configured resonant snubber inverters and describes in detail the operating principle of a single-phase version. The extended three-phase version is proposed with non-adjacent state space vector modulation. For hardware implementation, a single-phase 1-kW unit and a three-phase 100-kW unit were built to prove the concept. Experimental results show the superiority of the proposed topology.

  10. Resonant cortical dynamics of speech perception

    Science.gov (United States)

    Grossberg, Stephen

    2003-04-01

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

  11. Multidimensionally encoded magnetic resonance imaging.

    Science.gov (United States)

    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. Copyright © 2012 Wiley Periodicals, Inc.

  12. Voltage control of ferromagnetic resonance

    Directory of Open Access Journals (Sweden)

    Ziyao Zhou

    2016-06-01

    Full Text Available Voltage control of magnetism in multiferroics, where the ferromagnetism and ferroelectricity are simultaneously exhibiting, is of great importance to achieve compact, fast and energy efficient voltage controllable magnetic/microwave devices. Particularly, these devices are widely used in radar, aircraft, cell phones and satellites, where volume, response time and energy consumption is critical. Researchers realized electric field tuning of magnetic properties like magnetization, magnetic anisotropy and permeability in varied multiferroic heterostructures such as bulk, thin films and nanostructure by different magnetoelectric (ME coupling mechanism: strain/stress, interfacial charge, spin–electromagnetic (EM coupling and exchange coupling, etc. In this review, we focus on voltage control of ferromagnetic resonance (FMR in multiferroics. ME coupling-induced FMR change is critical in microwave devices, where the electric field tuning of magnetic effective anisotropic field determines the tunability of the performance of microwave devices. Experimentally, FMR measurement technique is also an important method to determine the small effective magnetic field change in small amount of magnetic material precisely due to its high sensitivity and to reveal the deep science of multiferroics, especially, voltage control of magnetism in novel mechanisms like interfacial charge, spin–EM coupling and exchange coupling.

  13. Magnetic resonance image guided brachytherapy.

    Science.gov (United States)

    Tanderup, Kari; Viswanathan, Akila N; Kirisits, Christian; Frank, Steven J

    2014-07-01

    The application of magnetic resonance image (MRI)-guided brachytherapy has demonstrated significant growth during the past 2 decades. Clinical improvements in cervix cancer outcomes have been linked to the application of repeated MRI for identification of residual tumor volumes during radiotherapy. This has changed clinical practice in the direction of individualized dose administration, and resulted in mounting evidence of improved clinical outcome regarding local control, overall survival as well as morbidity. MRI-guided prostate high-dose-rate and low-dose-rate brachytherapies have improved the accuracy of target and organs-at-risk delineation, and the potential exists for improved dose prescription and reporting for the prostate gland and organs at risk. Furthermore, MRI-guided prostate brachytherapy has significant potential to identify prostate subvolumes and dominant lesions to allow for dose administration reflecting the differential risk of recurrence. MRI-guided brachytherapy involves advanced imaging, target concepts, and dose planning. The key issue for safe dissemination and implementation of high-quality MRI-guided brachytherapy is establishment of qualified multidisciplinary teams and strategies for training and education. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. String Resonances at Hadron Colliders

    CERN Document Server

    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...

  15. 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.

  16. A resonant dc-dc power converter assembly

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a resonant DC-DC power converter assembly comprising a first resonant DC-DC power converter and a second resonant DC-DC power converter having identical circuit topologies. A first inductor of the first resonant DC-DC power converter and a second inductor of the s......The present invention relates to a resonant DC-DC power converter assembly comprising a first resonant DC-DC power converter and a second resonant DC-DC power converter having identical circuit topologies. A first inductor of the first resonant DC-DC power converter and a second inductor...

  17. Magnetic resonance force microscopy using ferromagnetic resonance of a magnetic tip excited by microwave transmission via a coaxial resonator

    Science.gov (United States)

    Kinoshita, Yukinori; Li, Yan Jun; Yoshimura, Satoru; Saito, Hitoshi; Sugawara, Yasuhiro

    2017-12-01

    The present work proposes magnetic resonance force microscopy (MRFM) based on ferromagnetic resonance (FMR) modulation of a magnetic tip using microwave transmission via a coaxial resonator instead of using conventional microwave irradiation by an external antenna. In this MRFM, the coaxial resonator is electrically connected to the magnetic cantilever tip, which enables simple implementation of FMR excitation of a magnetic tip in conventional magnetic force microscopy. The FMR frequency of the tip can be easily extracted from the reflection spectrum of a transmission line connected to the magnetic tip. The excitation of tip FMR is confirmed from the microwave frequency dependence of the mechanical response of the tip oscillation. This MRFM is effective for extracting the magnetic interaction force near a sample surface without perturbation of its magnetic state. Nanometer-scale imaging of magnetic domain structures on a demagnetized thin-film permanent magnet is successfully demonstrated.

  18. 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.

  19. Development of optical WGM resonators for biosensors

    Science.gov (United States)

    Brice, I.; Pirktina, A.; Ubele, A.; Grundsteins, K.; Atvars, A.; Viter, R.; Alnis, J.

    2017-12-01

    Whispering Gallery Mode (WGM) resonators are very sensitive to nanoparticles attaching to the surface. We simulate this process using COMSOL Wave Optics module. Our spherical WGM resonators are produced by melting a tip of an optical fiber and we measure optical Q factors in the 105 range. Molecular oxygen lines of the air in the 760 nm region are used as reference markers when looking for the shifts of the WGM resonance lines. We demonstrate WGM microresonator surface coating with a layer of ZnO nanorods as well as with polystyrene microspheres. Coatings produce increased contact surface. Additional layer of antigens/antibodies will be coated to make high-specificity biosensors.

  20. Trampoline metamaterial: Local resonance enhancement by springboards

    Science.gov (United States)

    Bilal, Osama R.; Hussein, Mahmoud I.

    2013-09-01

    We investigate the dispersion characteristics of locally resonant elastic metamaterials formed by the erection of pillars on the solid regions in a plate patterned by a periodic array of holes. We show that these solid regions effectively act as springboards leading to an enhanced resonance behavior by the pillars when compared to the nominal case of pillars with no holes. This local resonance amplification phenomenon, which we define as the trampoline effect, is shown to cause subwavelength bandgaps to increase in size by up to a factor of 4. This outcome facilitates the utilization of subwavelength metamaterial properties over exceedingly broad frequency ranges.

  1. Spatial solitons in a pumped semiconductor resonator.

    Science.gov (United States)

    Taranenko, V B; Weiss, C O; Stolz, W

    2001-10-15

    Bright and dark spatial solitons are observed in an optically pumped semiconductor resonator. The pumping allows us to reduce considerably the light intensity necessary for the existence of the solitons and alleviates thermal load problems. Experiments are found to agree qualitatively with calculations based on a simple large-aperture semiconductor resonator model. The role of the signs of the absorptive and reactive nonlinearities in soliton existence is discussed in relation to the nonlinear resonance effect, the tilted-wave mechanism of pattern formation, and the sign of the population inversion.

  2. Josephson plasma resonance in superconducting multilayers

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig; Sakai, S

    1998-01-01

    We derive an analytical solution for the Josephson plasma resonance of superconducting multilayers. This analytical solution is derived mainly for low-T-c systems with magnetic coupling between the superconducting layers. but many features of our results are more general, and thus an application...... to the recently derived plasma resonance phenomena for high-T-c superconductors of the Bi2Sr2CaCu2Ox type is discussed. Our approach allows us to give full details of the different plasma resonance excitations, and we also predict the existence of new nonlinear effects, so far only identified in single junctions....

  3. 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...... to the low thermal mass of the strings. A temperature resolution of 2.5×10-4 °C has been achieved with silicon nitride strings. The theoretical limit for the temperature resolution of 8×10-8 °C has not been reached yet and requires further improvement of the sensor....

  4. Engineering resonance dynamics of plasmon hybridized systems

    Science.gov (United States)

    Kodigala, Ashok; Lepetit, Thomas; Kanté, Boubacar

    2015-01-01

    The ability to control resonances is crucial in advancing applications of plasmonics ranging from chemical and biological sensing at the single molecule level to on-chip communication via fully optical interconnects. To this end, a method employing an effective Hamiltonian formalism is described to study and tailor resonances of plasmonic systems at optical frequencies. Using this method, we compute the complex poles of the scattering matrix and investigate resonance dynamics of coupled plasmonic bars. We show that symmetry breaking, by tailoring near-field interactions in the whole complex plane, provides a very large degree of tunability, including a controllable negative coupling regime.

  5. 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.

  6. Theoretical foundations of electron spin resonance

    CERN Document Server

    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

  7. Electron spin resonance (ESR), electron nuclear double resonance (ENDOR) and general triple resonance of irradiated biocarbonates

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, D.U.; Rossi, A.M. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)

    1996-11-01

    Several irradiated bicarbonates were studied by magnetic resonance techniques. Seven paramagnetic species, attributed to CO{sub 2}{sup -}, SO{sub 2}{sup -} and SO{sub 3}{sup -} were identified. Comparison between radiation induced defects in bioaragonites and aragonite single-crystals show that isotropic and orthorhombic CO{sub 2}{sup -}centers with broad line spectra are not produced in the latter samples. Vibrational and rotational properties of isotropic CO{sub 2}{sup -} centers were studied from low temperature Q-band spectras. Vibrational frequency is determined from the {sup 13}CO{sub 2}{sup -} hyperfine spectrum and yielded {nu} 1.54 x 10{sup 13} s{sup -1}. The correlation time for isotropic CO{sub 2}{sup -}, ({tau}c) = 1.2 x 10{sup -11}s (T = 300 K0), is typical of radicals rotating in liquids. ENDOR and General Triple spectroscopy show that orthorhombic CO{sub 2}{sup -} centres are surrounded by water molecules located in the second nearest CO{sub 2}{sup 2-} sites at 5.14, 5.35 and 6.02 A. Water molecules replacing carbonates or as liquid inclusion of growth solution in local crystal imperfections may be responsible for the variety of orthorhombic and isotropic CO{sub 2}{sup -} species, respectively. (author).

  8. 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.

  9. Mitigating Thermoelastic Dissipation of Flexural Micromechanical Resonators by Decoupling Resonant Frequency from Thermal Relaxation Rate

    Science.gov (United States)

    Zhou, Xin; Xiao, Dingbang; Wu, Xuezhong; Li, Qingsong; Hou, Zhanqiang; He, Kaixuan; Wu, Yulie

    2017-12-01

    This paper reports an alternative design strategy to reduce thermoelastic dissipation (TED) for isothermal-mode micromechanical resonators. This involves hanging lumped masses on a frame structure to decouple the resonant frequency and the effective beamwidth of the resonators, which enables the separation of the thermal relaxation rate and frequency of vibration. This approach is validated using silicon-based micromechanical disklike resonators engineered to isolate TED. A threefold improvement in the quality factor and a tenfold improvement in the decay-time constant is demonstrated. This work proposes a solution for isothermal-mode (flexural) micromechanical resonators to effectively mitigate TED. Specifically, this approach is ideal for designing high-performance gyroscope resonators based on microelectromechanical systems (MEMS) technology. It may pave the way for the next generation inertial-grade MEMS gyroscope, which remains a great challenge and is very appealing.

  10. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... Imaging Costs Video: Abdominal Ultrasound Video: Pelvic Ultrasound Radiology and You Sponsored by Image/Video Gallery Your ... Explains Magnetic Resonance Angiography (MRA) Transcript Welcome to Radiology Info dot org Hello, I’m Dr. Elliot ...

  11. Superconducting Resonant Inductive Power Coupling Project

    Data.gov (United States)

    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...

  12. 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.

  13. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... Lung Cancer Awareness Month Recently posted: Carotid Intima-Media Thickness Test Medical Imaging Costs Video: Abdominal Ultrasound Video: Pelvic Ultrasound Radiology and You Sponsored by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography ( ...

  14. Exploring Nurse Faculty Incivility and Resonant Leadership.

    Science.gov (United States)

    Casale, Katherine R

    The purpose of this quantitative correlational study was to explore the relationship between the frequency of interfaculty incivility among nurses in academia and observed levels of resonant leadership of immediate supervisors. Despite mandates to address incivility in health care, nurse faculty report high levels of horizontal incivility among their peers. No known quantitative research has measured the relationship between nurse faculty-to-faculty incivility and resonant leadership traits of leaders. Nursing faculty from 17 universities (n = 260) were emailed an anonymous link to answer survey questions about horizontal peer incivility and leaders' management styles. There was a significant inverse relationship (Pearson's r, -.560) between the frequency of experienced faculty-to-faculty incivility and the level of observed resonant leadership behaviors of participants' immediate supervisors. Resonant supervisory behaviors inversely correlated with nurse faculty peer incivility, with potential to impact satisfaction, recruitment, and retention.

  15. Central diffractive resonance production at the LHC

    Directory of Open Access Journals (Sweden)

    Fiore Roberto

    2016-01-01

    Full Text Available Central production of resonances resulting from the scattering of Pomerons in the central rapidity region of proton-proton scattering is studied. Estimates for relevant cross sections are presented.

  16. single voxel magnetic resonance spectroscopy in distinguishing

    African Journals Online (AJOL)

    2011-03-03

    Mar 3, 2011 ... magnetic resonance spectroscopy (MRI, MRS) in differentiating focal neoplastic lesions from focal non- neoplastic (infective or degenerative) brain lesions. Design: Descriptive, analytical - prospective study. Setting: The Aga Khan University MRI department. Subject: Seventy four consecutive patients.

  17. Review of cardiovascular magnetic resonance in human ...

    African Journals Online (AJOL)

    In recent times, cardiovascular magnetic resonance (CMR) imaging has emerged as the gold standard tool for assessment of a variety of indications, allowing comprehensive characterisation of functional, morphological, metabolic and haemodynamic sequelae of several cardiovascular pathologies. Furthermore, continued ...

  18. The role of magnetic resonance cholangiopancreatography and ...

    African Journals Online (AJOL)

    ) is accepted as the gold standard, there is a place for magnetic resonance cholangiopancreatography (MRCP) and diffusion-weighted imaging (DWI) in the diagnosis of obstructive biliary disorders. Aim: To compare the findings of MRCP with ...

  19. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... Video: Pelvic Ultrasound Radiology and You Sponsored by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography ( ... pictures of the major blood vessels throughout your body. It may be performed with or without contrast ...

  20. Nanofabricated Optomechanical Whispering Gallery Mode Resonators Project

    Data.gov (United States)

    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...

  1. 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 b...

  2. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... Dr. Elliot Fishman, a radiologist at Johns Hopkins Hospital in Baltimore, Maryland. I’d like to talk with you about magnetic resonance angiography, or as it’s commonly known, MRA. ...

  3. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    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 ...

  4. Wideband MEMS Resonator Using Multifrequency Excitation

    KAUST Repository

    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.

  5. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... mild sedative prior to the examination. For more information about Magnetic Resonance Angiography of MRA or any ... Inc. (RSNA). To help ensure current and accurate information, we do not permit copying but encourage linking ...

  6. Fano resonances in plasmonic nanoparticle aggregates.

    Science.gov (United States)

    Mirin, Nikolay A; Bao, Kui; Nordlander, Peter

    2009-04-23

    We investigate the plasmonic properties of a symmetric silver sphere septamer and show that the extinction spectrum exhibits a narrow Fano resonance. Using the plasmon hybridization approach and group theory we show that this Fano resonance is caused by the interference of two bonding dipolar subradiant and superradiant plasmon modes of E(1u) symmetry. We investigate the effect of structural symmetry breaking and show that the energy and shape of the Fano resonance can be tuned over a broad wavelength range. We show that the wavelength of the Fano resonance depends very sensitively on the dielectric permittivity of the surrounding media with one of the highest LSPR sensitivities reported for a finite nanostructure.

  7. Microwave mode structure of superconducting metamaterial resonators

    Science.gov (United States)

    Wang, Haozhi; Rouxinol, Francisco; Lahaye, Matthew; Plourde, Britton

    2015-03-01

    Arrays of lumped circuit elements can be used to form metamaterial resonant structures that exhibit novel behavior compared to resonators made from conventional distributed transmission lines. By engineering the parameters and configurations of the lumped elements composing the unit cell of such a metamaterial resonator, one can generate spectra with wide stop-bands as well as pass-bands with dense microwave modes. If the metamaterials are fabricated from superconducting traces, the losses can be low enough to allow for these dense modes to be resolved and potentially coupled to quantum systems, such as superconducting qubits. We will present our low-temperature measurements of a variety of superconducting metamaterial resonators and we will compare these with numerical simulations of the microwave properties.

  8. Magnetic Resonance Spectroscopy of Breast Disease

    National Research Council Canada - National Science Library

    Ikeda, Debra

    2001-01-01

    We have developed a unique magnetic resonance imaging multi voxel pulse sequence producing spectroscopic images of key metabolites found in breast cancer, and validated our work with in vitro spectra and pathology...

  9. Acoustic Resonance Reaction Control Thruster (ARCTIC) Project

    Data.gov (United States)

    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...

  10. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... and You Take our survey Sponsored by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography (MRA) ... Carotid Intima-Media Thickness Test Medical Imaging Costs Video: Abdominal Ultrasound Video: Pelvic Ultrasound Radiology and You ...

  11. Internal and external resonances of dielectric disks

    NARCIS (Netherlands)

    Dettmann, C. P.; Morozov, G. V.; Sieber, M.; Waalkens, H.

    Circular microresonators (microdisks) are micron size dielectric disks embedded in a material of lower refractive index. They possess modes with complex eigenvalues (resonances) which are solutions of analytically given transcendental equations. The behavior of such eigenvalues in the small opening

  12. Wireless Magnetoelastic Resonance Sensors: A Critical Review

    Directory of Open Access Journals (Sweden)

    Keat G. Ong

    2002-07-01

    Full Text Available This paper presents a comprehensive review of magnetoelastic environmental sensor technology; topics include operating physics, sensor design, and illustrative applications. Magnetoelastic sensors are made of amorphous metallic glass ribbons or wires, with a characteristic resonant frequency inversely proportional to length. The remotely detected resonant frequency of a magnetoelastic sensor shifts in response to different physical parameters including stress, pressure, temperature, flow velocity, liquid viscosity, magnetic field, and mass loading. Coating the magnetoelastic sensor with a mass changing, chemically responsive layer enables realization of chemical sensors. Magnetoelastic sensors can be remotely interrogated by magnetic, acoustic, or optical means. The sensors can be characterized in the time domain, where the resonant frequency is determined through analysis of the sensor transient response, or in the frequency domain where the resonant frequency is determined from the frequency-amplitude spectrum of the sensor.

  13. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... Index A-Z Spotlight Recently posted: Carotid Intima-Media Thickness Test Medical Imaging Costs Video: Abdominal Ultrasound Video: Pelvic Ultrasound Radiology and You Sponsored by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography ( ...

  14. 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.

  15. Pseudomorphic Bipolar Quantum Resonant-Tunneling Transistor

    National Research Council Canada - National Science Library

    Seabaugh, Alan C; Frensley, William R; Randall, John N; Reed, Mark A; Farrington, Dewey L; Matyi, Richard J

    1989-01-01

    ...+ InGaAs quantum well of a double-barrier resonant-tunneling structure. The heterojunction transistor consists of an n-GaAs emitter and collector, undoped AlAs tunnel barriers, and a pseudomorphic p...

  16. High Energy Single Frequency Resonant Amplifier Project

    Data.gov (United States)

    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...

  17. Electronic dipole resonance in smoky quartz

    NARCIS (Netherlands)

    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.

  18. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... of Radiology (IDoR) Radiology and You Sponsored by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography ( ... pictures of the major blood vessels throughout your body. It may be performed with or without contrast ...

  19. 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...

  20. Enhanced energy storage in chaotic optical resonators

    KAUST Repository

    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.

  1. Resonant metallic nanostructures for enhanced terahertz spectroscopy

    KAUST Repository

    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.

  2. Thermally tunable quadruple Vernier racetrack resonators.

    Science.gov (United States)

    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.

  3. Nanoporous polymer ring resonators for biosensing

    OpenAIRE

    Mancuso, Matthew; Goddard, Julie M.; Erickson, David

    2011-01-01

    Optically resonant devices are promising as label-free biomolecular sensors due to their ability to concentrate electromagnetic energy into small mode volumes and their capacity for multiplexed detection. A fundamental limitation of current optical biosensor technology is that the biomolecular interactions are limited to the surface of the resonant device, while the highest intensity of electromagnetic energy is trapped within the core. In this paper, we present nanoporous polymer optofluidic...

  4. SS-HORSE method for studying resonances

    Energy Technology Data Exchange (ETDEWEB)

    Blokhintsev, L. D. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation); Mazur, A. I.; Mazur, I. A., E-mail: 008043@pnu.edu.ru [Pacific National University (Russian Federation); Savin, D. A.; Shirokov, A. M. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)

    2017-03-15

    A new method for analyzing resonance states based on the Harmonic-Oscillator Representation of Scattering Equations (HORSE) formalism and analytic properties of partial-wave scattering amplitudes is proposed. The method is tested by applying it to the model problem of neutral-particle scattering and can be used to study resonance states on the basis of microscopic calculations performed within various versions of the shell model.

  5. 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....

  6. de Sitter Space as a Resonance

    Science.gov (United States)

    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.

  7. de Sitter harmonies: Cosmological spacetimes as resonances

    Science.gov (United States)

    Maltz, Jonathan

    2017-03-01

    The aim of this work is to provide 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 is that transition amplitudes between certain states with asymptotically supersymmetric flat vacua contain resonant poles characteristic metastable intermediate states. A calculation employing constrained instantons is presented that illustrates this idea.

  8. Pulsed Adiabatic Photoassociation via Scattering Resonances

    OpenAIRE

    Han, Alex C.; Shapiro, Evgeny A.; Shapiro, Moshe

    2011-01-01

    We develop the theory for the Adiabatic Raman Photoassociation (ARPA) of ultracold atoms to form ultracold molecules in the presence of scattering resonances. Based on a computational method in which we replace the continuum with a discrete set of "effective modes", we show that the existence of resonances greatly aids in the formation of deeply bound molecular states. We illustrate our general theory by computationally studying the formation of $^{85}$Rb$_2$ molecules from pairs of colliding...

  9. Resonances in pi-K scattering

    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).

  10. Tuned driving of piezoelectric resonators: impedance matching

    OpenAIRE

    Fernández Lozano, José Francisco; Villegas, Marina; Ochoa, Pilar; Pons Rovira, José Luis; Ceres Ruiz, Ramón; Calderón Estévez, Leopoldo; Rocón, Eduardo

    2006-01-01

    [EN] For optimal operation of piezoelectric resonators, the electrical impedance of electronic drivers and the resonator itself must be matched. Lack of matching results in a non smooth transmission of electrical power between the drive and the load which, in turn, leads to heating and poor efficiency. The rest of properties of the driving voltage (frequency, amplitude and phase) are also affected by this mismatch. This paper presents the optimal design of power drivers for piezoelec...

  11. Majorana Fermion Induced Resonant Andreev Reflection

    OpenAIRE

    Law, K. T.; Lee, Patrick A.; Ng, T. K.

    2009-01-01

    We describe experimental signatures of Majorana fermion edge states, which form at the interface between a superconductor and the surface of a topological insulator. If a lead couples to the Majorana fermions through electron tunneling, the Majorana fermions induce \\textit{resonant} Andreev reflections from the lead to the grounded superconductor. The linear tunneling conductance is $0 $ ($2 e^2/h$) if there is an even (odd) number of vortices in the superconductor. Similar resonance occurs f...

  12. Resonant quantum transitions in trapped antihydrogen atoms.

    Science.gov (United States)

    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.

  13. Introduction to magnetic resonance methods in photosynthesis

    OpenAIRE

    Huber, Martina

    2009-01-01

    Electron paramagnetic resonance (EPR) and, more recently, solid-state nuclear magnetic resonance (NMR) have been employed to study photosynthetic processes, primarily related to the light-induced charge separation. Information obtained on the electronic structure, the relative orientation of the cofactors, and the changes in structure during these reactions should help to understand the efficiency of light-induced charge separation. A short introduction to the observables derived from magneti...

  14. Resonance controlled transport in phase space

    Science.gov (United States)

    Leoncini, Xavier; Vasiliev, Alexei; Artemyev, Anton

    2018-02-01

    We consider the mechanism of controlling particle transport in phase space by means of resonances in an adiabatic setting. Using a model problem describing nonlinear wave-particle interaction, we show that captures into resonances can be used to control transport in momentum space as well as in physical space. We design the model system to provide creation of a narrow peak in the distribution function, thus producing effective cooling of a sub-ensemble of the particles.

  15. 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 values for {sup 238}U, {sup 237}Np, {sup 243}Cm, {sup 245}Cm, {sup 246}Cm and {sup 241}Am nuclei in the resolved resonance region are presented. The applied method based on the idea that experimental resonance missing results in correlated changes of reduced neutron widths and level spacings distributions is discussed. (author)

  16. Resonance width distribution for open quantum systems

    OpenAIRE

    Shchedrin, Gavriil; Zelevinsky, Vladimir

    2011-01-01

    Recent measurements of resonance widths for low-energy neutron scattering off heavy nuclei show large deviations from the standard Porter-Thomas distribution. We propose a new resonance width distribution based on the random matrix theory for an open quantum system. Two methods of derivation lead to a single analytical expression; in the limit of vanishing continuum coupling, we recover the Porter-Thomas distribution. The result depends on the ratio of typical widths $\\Gamma$ to the energy le...

  17. Nanocrystalline diamond enhanced thickness shear mode resonator

    OpenAIRE

    WILLIAMS, Oliver; MORTET, Vincent; DAENEN, Michael; HAENEN, Ken

    2007-01-01

    A nanocrystalline diamond coated thickness shear mode resonator has been fabricated as an alternative to the quartz crystal microbalance. Due to the low temperature phase transition of quartz, the piezoelectric material was replaced with langasite, a piezoelectric with no phase transition up to its melting point. The resulting device shows clear resonant behavior and oscillates in both air and in liquid. The diamond coating shows clear faceting by scanning electron microscopy and sp(3) bondin...

  18. Nanocrystalline diamond enhanced thickness shear mode resonator

    Science.gov (United States)

    Williams, Oliver A.; Mortet, Vincent; Daenen, Michael; Haenen, Ken

    2007-02-01

    A nanocrystalline diamond coated thickness shear mode resonator has been fabricated as an alternative to the quartz crystal microbalance. Due to the low temperature phase transition of quartz, the piezoelectric material was replaced with langasite, a piezoelectric with no phase transition up to its melting point. The resulting device shows clear resonant behavior and oscillates in both air and in liquid. The diamond coating shows clear faceting by scanning electron microscopy and sp3 bonding by Raman spectroscopy.

  19. Nuclear Magnetic Resonance Imaging: Current Capabilities

    OpenAIRE

    Davis, Peter L.; Crooks, Lawrence E.; Margulis, Alexander R.; Kaufman, Leon

    1982-01-01

    Nuclear magnetic resonance imaging can produce tomographic images of the body without ionizing radiation. Images of the head, chest, abdomen, pelvis and extremities have been obtained and normal structures and pathology have been identified. Soft tissue contrast with this method is superior to that with x-ray computerized tomography and its spatial resolution is approaching that of x-ray computerized tomography. In addition, nuclear magnetic resonance imaging enables us to image along the sag...

  20. Chains of nonlinear and tunable superconducting resonators

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Michael; Eder, Peter; Xie, Edwar; Deppe, Frank; Huebl, Hans; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching (Germany); Physik-Department, TU Muenchen, 85748 Garching (Germany); Nanosystems Initiative Munich (NIM), 80799 Muenchen (Germany); Wulschner, Friedrich; Goetz, Jan [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching (Germany); Physik-Department, TU Muenchen, 85748 Garching (Germany); Fedorov, Kirill; Marx, Achim [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching (Germany)

    2016-07-01

    We present progress towards the fabrication and characterization of a quantum simulation system of the Bose-Hubbard-Hamiltonian in the driven dissipative regime in the realm of circuit QED. The system consists of series-connected, capacitively coupled, nonlinear and tunable superconducting resonators. The nonlinearity is achieved by galvanically coupled SQUIDs, placed in the current anti-node of each resonator and can be tuned by external coils and on-chip antennas.

  1. Green function in the resonance region

    Energy Technology Data Exchange (ETDEWEB)

    Cirigliano, V. [Department of Physics, California Institute of Technology Pasadena, CA 91125 (United States); Ecker, G. [Institut fuer Theoretische Physik, Universitaet Wien, Boltzmanngasse 5, A-1090 Vienna (Austria); Eidemueller, M. [Departament de Fisica Teorica, IFIC, CSIC-Universitat de Valencia, Edifici d' Instituts de Paterna, Apt. Correus 22085, E-46071 Valencia (Spain); Pich, A. [Departament de Fisica Teorica, IFIC, CSIC-Universitat de Valencia, Edifici d' Instituts de Paterna, Apt. Correus 22085, E-46071 Valencia (Spain); Portoles, J. [Departament de Fisica Teorica, IFIC, CSIC-Universitat de Valencia, Edifici d' Instituts de Paterna, Apt. Correus 22085, E-46071 Valencia (Spain)]. E-mail: jorge.portoles@ific.uv.es

    2004-08-19

    We analyze the three-point function of vector, axial-vector and pseudoscalar currents. In the spirit of large NC, a resonance dominated Green function is confronted with the leading high-energy behaviour from the operator product expansion. The matching is shown to be fully compatible with a chiral resonance Lagrangian and it allows to determine some of the chiral low-energy constants of O(p6)

  2. Resonance-Enhanced Nonlinear Optical Effects

    Science.gov (United States)

    Sun, Xuan

    Nonlinear optical processes, which manifest as many interesting phenomena such as nonlinear wave mixing, optical rectification, intensity-dependent refractive index change, harmonic generation, etc., have found very broad applications. Unfortunately, most optical media exhibit rather weak optical nonlinearities and a majority of nonlinear optical processes have to rely on substantial optical powers to support nonlinear wave interactions, which becomes a major challenge for nonlinear photonic application. This thesis is devoted to exploring enhanced nonlinear optical phenomena, by taking advantage of a certain type of resonance to enhance the nonlinear wave interactions. For this purpose, we employed both natural atomic resonances via electron transition and engineered optical resonances in micro/nanophotonic device structures, for different applications. These two types of resonances, although distinctive in their physical natures, both are able to significantly increase the strength and elongate the time of optical wave interactions, thus leading to dramatic enhancement of nonlinear optical effects. On one hand, we utilized unique energy-level structures in alkali vapor plasmas to dramatically enhance the electron tunneling ionization process and to produce significant resonance-enhanced four-wave mixing for efficient terahertz (THz) wave generation that is crucial for long-wave application. On the other hand, we utilized the enhancement offered by high-Q optical resonances inside microresonators to produce significant photothermal backaction to dramatically suppress the fundamental temperature fluctuations of microresonators, which is essential for sensing and metrology applications. With such cavity-resonance enhancement, we revealed a new regime of nonlinear optical oscillation dynamics in lithium niobate microresonators that results from unique competition between the thermo-optic nonlinear effect and the photorefractive effect, which is inaccessible to

  3. Feshbach resonances in ultracold {sup 39}K

    Energy Technology Data Exchange (ETDEWEB)

    D' Errico, Chiara [LENS and Dipartimento di Fisica, Universita di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Zaccanti, Matteo [LENS and Dipartimento di Fisica, Universita di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Fattori, Marco [Museo Storico della Fisica e Centro Studi e Ricerche ' Enrico Fermi' , Compendio del Viminale, 00184 Roma (Italy); Roati, Giacomo [LENS and Dipartimento di Fisica, Universita di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Inguscio, Massimo [LENS and Dipartimento di Fisica, Universita di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Modugno, Giovanni [LENS and Dipartimento di Fisica, Universita di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Simoni, Andrea [Laboratoire de Physique des Atomes, Lasers, Molecules et Surfaces, UMR 6627 du CNRS and Universite de Rennes, 35042 Rennes Cedex (France)

    2007-07-15

    We discover several magnetic Feshbach resonances in collisions of ultracold {sup 39}K atoms, by studying atom losses and molecule formation. Accurate determination of the magnetic-field resonance locations allows us to optimize a quantum collision model for potassium isotopes. We employ the model to predict the magnetic-field dependence of scattering lengths and of near-threshold molecular levels. Our findings will be useful to plan future experiments on ultracold {sup 39}K atoms and molecules.

  4. Pygmy dipole resonance in stable nuclei

    Indian Academy of Sciences (India)

    the ∆L = 0 spin-flip M1 resonance. A case study of the 208Pb(p, p ) reaction at. E = 295 MeV was performed. A background-subtracted spectrum measured at 0◦ spectrometer angle is displayed in the top part of figure 3. In the giant resonance region, prominent excitation of the GDR is observed. Because of the excellent.

  5. Strong Coupling Optimization With Planar Spiral Resonators

    CERN Document Server

    Klein, Avraham; 10.1016/j.cap.2011.02.017

    2011-01-01

    Planar spirals offer a highly scalable geometry appropriate for wireless power transfer via strongly coupled inductive resonators. We numerically derive a set of geometric scale and material independent coupling terms, and analyze a simple model to identify design considerations for a variety of different materials. We use our model to fabricate integrated planar resonators of handheld sizes, and optimize them to achieve high Q factors, comparable to much larger systems, and strong coupling over significant distances with approximately constant efficiency.

  6. Electrostatically actuated torsional resonant sensors and switches

    KAUST Repository

    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.

  7. Plasmon resonant cavities in vertical nanowire arrays

    Energy Technology Data Exchange (ETDEWEB)

    Bora, M; Bond, T; Behymer, E; Chang, A

    2010-02-23

    We investigate tunable plasmon resonant cavity arrays in paired parallel nanowire waveguides. Resonances are observed when the waveguide length is an odd multiple of quarter plasmon wavelengths, consistent with boundary conditions of node and antinode at the ends. Two nanowire waveguides satisfy the dispersion relation of a planar metal-dielectric-metal waveguide of equivalent width equal to the square field average weighted gap. Confinement factors over 103 are possible due to plasmon focusing in the inter-wire space.

  8. Collective light forces on atoms in resonators

    Energy Technology Data Exchange (ETDEWEB)

    Black, Adam T; Thompson, James K; Vuletic, Vladan [Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2005-05-14

    We study resonator-induced light forces arising from cooperative atom-light interaction. For such collective processes, the force on the sample can be orders of magnitude larger than the sum of conventional light forces on individual atoms. Since resonator-induced light forces can be dissipative even when the incident light is far detuned from atomic transitions, they may be applicable to target particles with a complex level structure.

  9. Collaborative resonant writing and musical improvisation to explore the concept of resonance

    DEFF Research Database (Denmark)

    Bonde, Lars Ole

    2018-01-01

    and acoustic sounding that offers a clear logic, (2) a metaphorical conceptualization used to describe and understand complex psychological processes of human relationships. The process of collaborative writing led to the discovery or development of a nine-step procedure including different collaborative......, resonant writing procedures and musical improvisation as well as a series of metaphors to explain therapeutic interaction, resonant learning and ways of resonant exploration....

  10. Do resonating bells increase jellyfish swimming performance?

    Science.gov (United States)

    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.

  11. Slow Light in Coupled Resonator Optical Waveguides

    Science.gov (United States)

    Chang, Hongrok; Gates, Amanda L.; Fuller, Kirk A.; Gregory, Don A.; Witherow, William K.; Paley, Mark S.; Frazier, Donald O.; Smith, David D.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    Recently, we discovered that a splitting of the whispering gallery modes (WGMs) occurs in coupled resonator optical waveguides (CROWs), and that these split modes are of a higher Q than the single-resonator modes, leading to enormous circulating intensity magnification factors that dramatically reduce thresholds for nonlinear optical (NLO) processes. As a result of the enhancements in Q, pulses propagating at a split resonance can propagate much slower (faster) for over (under)-coupled structures, due to the modified dispersion near the split resonance. Moreover, when loss is considered, the mode-splitting may be thought of as analogous to the Autler-Townes splitting that occurs in atomic three-level lambda systems, i.e., it gives rise to induced transparency as a result of destructive interference. In under- or over-coupled CROWs, this coupled resonator induced transparency (CRIT) allows slow light to be achieved at the single-ring resonance with no absorption, while maintaining intensities such that NLO effects are maximized. The intensity magnification of the circulating fields and phase transfer characteristics are examined in detail.

  12. 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.

  13. Fluid mechanical model of the Helmholtz resonator

    Science.gov (United States)

    Hersh, A. S.; Walker, B.

    1977-01-01

    A semi-empirical fluid mechanical model of the acoustic behavior of Helmholtz resonators is presented which predicts impedance as a function of the amplitude and frequency of the incident sound pressure field and resonator geometry. The model assumes that the particle velocity approaches the orifice in a spherical manner. The incident and cavity sound fields are connected by solving the governing oscillating mass and momentum conservation equations. The model is in agreement with the Rayleigh slug-mass model at low values of incident sound pressure level. At high values, resistance is predicted to be independent of frequency, proportional to the square root of the amplitude of the incident sound pressure field, and virtually independent of resonator geometry. Reactance is predicted to depend in a very complicated way upon resonator geometry, incident sound pressure level, and frequency. Nondimensional parameters are defined that divide resonator impedance into three categories corresponding to low, moderately low, and intense incident sound pressure amplitudes. The two-microphone method was used to measure the impedance of a variety of resonators. The data were used to refine and verify the model.

  14. Frequency latching in nonlinear micromechanical resonators

    Science.gov (United States)

    Wei, Xueyong; Zhang, Tianyi; Jiang, Zhuangde; Ren, Juan; Huan, Ronghua

    2017-04-01

    The resonance frequency of a nonlinear micromechanical resonator has a dependence on its modal amplitude known as the A-f effect. Here, we experimentally demonstrated that the A-f effect can be limited by the mode interaction in micromechanical resonators. The clamped-clamped beam resonator investigated in this work has a nonlinear in-plane (IP) vibration mode and a linear out-of-plane (OOP) vibration mode. In the case of single ended driving with various Vdc, the resonance frequency of the IP mode tuned through the A-f effect reaches that of the OOP mode and is limited by the OOP mode due to the modal interaction and electrostatic softening effect. In the case of double ended driving, however, the resonance frequency of the IP mode is latched to that of the OOP mode after A-f tuning and a frequency stabilized region is observed. A theoretical model is also put forward to explain this phenomenon through numerical simulations.

  15. Resonant oscillations in open axisymmetric tubes

    Science.gov (United States)

    Amundsen, D. E.; Mortell, M. P.; Seymour, B. R.

    2017-12-01

    We study the behaviour of the isentropic flow of a gas in both a straight tube of constant cross section and a cone, open at one end and forced at or near resonance at the other. A continuous transition between these configurations is provided through the introduction of a geometric parameter k associated with the opening angle of the cone where the tube corresponds to k=0. The primary objective is to find long-time resonant and near-resonant approximate solutions for the open tube, i.e. k→ 0. Detailed analysis for both the tube and cone in the limit of small forcing (O(ɛ 3)) is carried out, where ɛ 3 is the Mach number of the forcing function and the resulting flow has Mach number O(ɛ ). The resulting approximate solutions are compared with full numerical simulations. Interesting distinctions between the cone and the tube emerge. Depending on the damping and detuning, the responses for the tube are continuous and of O(ɛ ). In the case of the cone, the resonant response involves an amplification of the fundamental resonant mode, usually called the dominant first-mode approximation. However, higher modes must be included for the tube to account for the nonlinear generation of higher-order resonances. Bridging these distinct solution behaviours is a transition layer of O(ɛ 2) in k. It is found that an appropriately truncated set of modes provides the requisite modal approximation, again comparing well to numerical simulations.

  16. Asymmetrically coupled resonators for mass sensing

    Science.gov (United States)

    Marquez, S.; Alvarez, M.; Plaza, J. A.; Villanueva, L. G.; Dominguez, C.; Lechuga, L. M.

    2017-09-01

    Mechanically coupled resonators have been applied in the last years to the development of nanomechanical mass-sensors based on the detection of the different vibration modes of the system by measuring on a single resonator. Their sensitivity and capability for detecting multiple analytes strongly depends on the design and coupling strength between the mechanically coupled resonators in an array format. We present a theoretical and experimental study of the behavior of an asymmetrically coupled array of four different resonators. These doubly clamped beam resonators are elastically coupled by an overhang region of varying length along the transversal axis of the array. The results show that parameters such as the gap between microbeams and the overhang length affect the coupling strength, tuning the system from highly disordered and highly localized (weak coupling) to highly delocalized (strong coupling). In the strong coupling and partially localized case, the distances between resonant peaks are larger, reaching higher eigenfrequency values. In this case, relative changes in a specific eigenstate, due to an added mass, can be markedly large due to the energy distribution over a single microbeam. A strong coupling also facilitates performing the detection on the relative frequency shift mode, which can usually be resolved with better precision than the amplitude changes.

  17. Resonances in odd-odd 182Ta

    Directory of Open Access Journals (Sweden)

    Brits C.P.

    2017-01-01

    Full Text Available Enhanced γ-decay on the tail of the giant electric dipole resonance, such as the scissors or pygmy resonances, can have significant impact on (n,γ reaction rates. These rates are important input for modeling processes that take place in astrophysical environments and nuclear reactors. Recent results from the University of Oslo indicate the existence of a significant enhancement in the photon strength function for nuclei in the actinide region due to the scissors resonance. Further, the M1 strength distribution of the scissors resonances in rare earth nuclei has been studied extensively over the years. To investigate the evolution and persistence of the scissor resonance in other mass regions, an experiment was performed utilizing the NaI(Tl γ-ray detector array (CACTUS and silicon particle telescopes (SiRi at the University of Oslo Cyclotron laboratory. Particle-γ coincidences from the 181Ta(d,p182Ta and 181Ta(d,d'181Ta reactions were used to measure the nuclear level density and photon strength function of the well-deformed 181Ta and 182Ta systems, to investigate the existence of resonances below the neutron separation energy.

  18. Resonances in odd-odd 182Ta

    Science.gov (United States)

    Brits, C. P.; Wiedeking, M.; Bello Garrote, F. L.; Bleuel, D. L.; Giacoppo, F.; Görgen, A.; Guttormsen, M.; Hadynska-Klek, K.; Hagen, T. W.; Ingeberg, V. W.; Kheswa, B. V.; Klintefjord, M.; Larsen, A. C.; Malatji, K. L.; Nyhus, H. T.; Papka, P.; Renstrøm, T.; Rose, S.; Sahin, E.; Siem, S.; Tveten, G. M.; Zeiser, F.

    2017-09-01

    Enhanced γ-decay on the tail of the giant electric dipole resonance, such as the scissors or pygmy resonances, can have significant impact on (n,γ) reaction rates. These rates are important input for modeling processes that take place in astrophysical environments and nuclear reactors. Recent results from the University of Oslo indicate the existence of a significant enhancement in the photon strength function for nuclei in the actinide region due to the scissors resonance. Further, the M1 strength distribution of the scissors resonances in rare earth nuclei has been studied extensively over the years. To investigate the evolution and persistence of the scissor resonance in other mass regions, an experiment was performed utilizing the NaI(Tl) γ-ray detector array (CACTUS) and silicon particle telescopes (SiRi) at the University of Oslo Cyclotron laboratory. Particle-γ coincidences from the 181Ta(d,p)182Ta and 181Ta(d,d')181Ta reactions were used to measure the nuclear level density and photon strength function of the well-deformed 181Ta and 182Ta systems, to investigate the existence of resonances below the neutron separation energy. Note to the reader: the title of this article has been corrected on September 19, 2017.

  19. Miniaturized resonant sensors for harsh environments

    Science.gov (United States)

    Schmidtchen, Silja; Richter, Denny; Sauerwald, Jan; Fritze, Holger

    2013-05-01

    Miniaturized active structures for operation temperatures between 500 and 1000 °C are presented. They base on langasite single crystals (La3Ga5SiO14) which exhibit piezoelectrically excited bulk acoustic waves up to at least 1000 °C. Those devices enable new high-temperature sensing approaches. Resonant microbalances are of particular interest since they correlate very small gas composition-dependent mass changes of thin films already deposited onto the resonators with the resonance frequency shift of such devices. Thereby, high-temperature processes as occurring in combustion systems can be monitored in-situ. Miniaturization of those sensor devices improves the sensitivity due to higher operation frequencies. Arrays consisting preferably of miniaturized devices increase the selectivity. Miniaturization of high-temperature devices requires even more stable materials due to the increased effect of e. g. diffusion processes. Further, the resonator design, the arrangement of electrodes and sensor films, the vibration profiles etc. must be reviewed critically in order to take account for their miniaturization. Beside the characterization of the electromechanical properties such as temperature dependent resonance frequency and loss, the specific vibration profiles of devices like membranes of different shape, cantilevers and tuning forks are determined. For this purpose a novel measurement system based on a laser Doppler vibrometer is used to characterize different types of resonant sensor devices in-situ at high temperatures and in different atmospheres. Mapping of the sample surfaces provides the spatial distribution of the mechanical displacement and, thereby, the vibration modes.

  20. Stochastic resonance during a polymer translocation process.

    Science.gov (United States)

    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.

  1. Composite lateral electric field excited piezoelectric resonator.

    Science.gov (United States)

    Zaitsev, B D; Shikhabudinov, A M; Borodina, I A; Teplykh, A A; Kuznetsova, I E

    2017-01-01

    The novel method of suppression of parasitic oscillations in lateral electric field excited piezoelectric resonator is suggested. Traditionally such resonator represents the piezoelectric plate with two electrodes on one side of the plate. The crystallographic orientation of the plate is selected so that the tangential components of electric field excite bulk acoustic wave with given polarization travelling along the normal to the plate sides. However at that the normal components of field excite the parasitic Lamb waves and bulk waves of other polarization which deteriorate the resonant properties of the resonator. In this work we suggest to separate the source of the HF electric field and resounded piezoelectric plate by air gap. In this case the tangential components of the field in piezoelectric plate do not practically weaken but normal components significantly decrease. This method is realized on the composite resonator having the structure "glass plate with rectangular electrodes - air gap - plate of 128 Y-X lithium niobate." It has been shown that there exist the optimal value of the width gap which ensure the good quality of series and parallel resonances in frequency range 3-4MHz with record values of Q-factor of ∼15,000 in both cases. Copyright © 2016. Published by Elsevier B.V.

  2. Imaging of surfaces by concurrent surface plasmon resonance and surface plasmon resonance-enhanced fluorescence.

    Directory of Open Access Journals (Sweden)

    Rahber Thariani

    Full Text Available Surface plasmon resonance imaging and surface plasmon induced fluorescent are sensitive tools for surface analysis. However, existing instruments in this area have provided limited capability for concurrent detection, and may be large and expensive. We demonstrate a highly cost-effective system capable of concurrent surface plasmon resonance microscopy (SPRM and surface plasmon resonance-enhanced fluorescence (SPRF imaging, allowing for simultaneous monitoring of reflectivity and fluorescence from discrete spatial regions. The instrument allows for high performance imaging and quantitative measurements with surface plasmon resonance, and surface plasmon induced fluorescence, with inexpensive off-the-shelf components.

  3. An actively controlled silicon ring resonator with a fully tunable Fano resonance

    Science.gov (United States)

    Li, A.; Bogaerts, W.

    2017-09-01

    We demonstrate a novel way to generate Fano resonance with tunable wavelength, extinction ratio, and slope rate. The device is a silicon add-drop microring with two integrated tunable reflectors inside, which form an embedded Fabry-Perot cavity. The fabrication is executed at a commercial CMOS foundry. Fano resonance at the drop port is generated from the interference between the Fabry-Perot cavity mode and the ring resonance mode. By tuning the reflectivities of these two reflectors with integrated heaters, various Fano resonance shapes can be achieved with a maximum extinction ratio over 40 dB and a slope rate more than 700 dB/nm.

  4. Geometry dependence of temperature coefficient of resonant frequency in highly sensitive resonant thermal sensors

    Science.gov (United States)

    Inomata, Naoki; Ono, Takahito

    2017-08-01

    In this paper, the geometry dependence of the temperature coefficient of resonant frequency (TCRF) is investigated and compared with a theoretical thermal stress change using Si mechanical microresonators. The used resonators have Y, T, I (conventional double-supported type) and arrow shapes, and in each shape the resonant frequency change of the resonator is measured in relation to changes in the amount of heat input to the resonator. The change trend in the experimental resonant frequency and the theoretical thermal stress in changing the temperature are consist. The TCRF in each resonator is Y: -653, T: -162, I: -417, and the arrow is 174 ppm/K. These absolute values are much higher than those of conventional cantilevered Si resonators (-34.9 ppm/K). In addition, the frequency fluctuations based on Allan deviation are experimentally evaluated considering the theoretical thermal fluctuation noise. It is considered that use of this technique to improve the TCRF of resonators by changing the geometry has the possibility of creating a sensor with highly sensitive thermal detection.

  5. An Electromagnetic Resonance Circuit for Liquid Level Detection

    Science.gov (United States)

    Hauge, B. L.; Helseth, L. E.

    2012-01-01

    Electromagnetic resonators are often used to detect foreign materials. Here we present a simple experiment for the measurement of liquid level. The resonator, consisting of a coil and a capacitor, is brought to resonance by an external magnetic field source, and the corresponding resonance frequency is determined using Fourier analysis combined…

  6. Transverse Mode Multi-Resonant Single Crystal Transducer

    Science.gov (United States)

    Snook, Kevin A. (Inventor); Liang, Yu (Inventor); Luo, Jun (Inventor); Hackenberger, Wesley S. (Inventor); Sahul, Raffi (Inventor)

    2015-01-01

    A transducer is disclosed that includes a multiply resonant composite, the composite having a resonator bar of a piezoelectric single crystal configured in a d(sub 32) transverse length-extensional resonance mode having a crystallographic orientation set such that the thickness axis is in the (110) family and resonance direction is the (001) family.

  7. 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.

  8. Experimental evidence of resonant effective permittivity in a dielectric metamaterial

    Science.gov (United States)

    Lepetit, T.; Akmansoy, É.; Ganne, J.-P.

    2011-01-01

    We designed and fabricated a dielectric metamaterial consisting of one set of high permittivity resonators. We experimentally showed that this metamaterial exhibits resonant effective permittivity, issued from the second mode of Mie resonances of these resonators. Therefore, metamaterials consisting of high permittivity resonators may provide either effective permeability or permittivity issued from the first two modes of Mie resonances, respectively. This ensures that all-dielectric metamaterials involving two sets of matched high permittivity resonators may exhibit negative index issued from these two modes, notably up to the terahertz domain.

  9. Fano resonance formula for lossy two-port systems.

    Science.gov (United States)

    Yoon, Jae Woong; Magnusson, Robert

    2013-07-29

    We provide a modified Fano resonance formula applicable to dissipative two-port resonance systems. Based on a generic coupled-resonator model, the formula embodies loss-related correction terms and fundamental resonance parameters that can be determined by an analytic method or experimentally as opposed to finding phenomenological parameters by fitting to numerical results. The theory applies physically meaningful resonance parameters including resonance frequency, total decay rates, and partial radiation probabilities. For example, it shows that the classic Fano shape parameter q is given directly in terms of the phase difference between the resonant and non-resonant transmission pathways. Our new resonance formula quantitatively expresses the resonance spectra pertaining to modal nanophotonic and surface-plasmonic thin-film structures as verified by comparing with exact numerical models.

  10. Resonance region measurements of dysprosium and rhenium

    Directory of Open Access Journals (Sweden)

    Leinweber Gregory

    2017-01-01

    Full Text Available Neutron capture and transmission measurements have been performed, and resonance parameter analysis has been completed for dysprosium, Dy, and rhenium, Re. The 60 MeV electron accelerator at RPI Gaerttner LINAC Center produced neutrons in the thermal and epithermal energy regions for these measurements. Transmission measurements were made using 6Li glass scintillation detectors. The neutron capture measurements were made with a 16-segment NaI multiplicity detector. The detectors for all experiments were located at ≈25 m except for thermal transmission, which was done at ≈15 m. The dysprosium samples included one highly enriched 164Dy metal, 6 liquid solutions of enriched 164Dy, two natural Dy metals. The Re samples were natural metals. Their capture yield normalizations were corrected for their high gamma attenuation. The multi-level R-matrix Bayesian computer code SAMMY was used to extract the resonance parameters from the data. 164Dy resonance data were analyzed up to 550 eV, other Dy isotopes up to 17 eV, and Re resonance data up to 1 keV. Uncertainties due to resolution function, flight path, burst width, sample thickness, normalization, background, and zero time were estimated and propagated using SAMMY. An additional check of sample-to-sample consistency is presented as an estimate of uncertainty. The thermal total cross sections and neutron capture resonance integrals of 164Dy and Re were determined from the resonance parameters. The NJOY and INTER codes were used to process and integrate the cross sections. Plots of the data, fits, and calculations using ENDF/B-VII.1 resonance parameters are presented.

  11. Magnetic resonance imaging of the fetal brain.

    Science.gov (United States)

    Tee, L Mf; Kan, E Yl; Cheung, J Cy; Leung, W C

    2016-06-01

    This review covers the recent literature on fetal brain magnetic resonance imaging, with emphasis on techniques, advances, common indications, and safety. We conducted a search of MEDLINE for articles published after 2010. The search terms used were "(fetal OR foetal OR fetus OR foetus) AND (MR OR MRI OR [magnetic resonance]) AND (brain OR cerebral)". Consensus statements from major authorities were also included. As a result, 44 relevant articles were included and formed the basis of this review. One major challenge is fetal motion that is largely overcome by ultra-fast sequences. Currently, single-shot fast spin-echo T2-weighted imaging remains the mainstay for motion resistance and anatomical delineation. Recently, a snap-shot inversion recovery sequence has enabled robust T1-weighted images to be obtained, which is previously a challenge for standard gradient-echo acquisitions. Fetal diffusion-weighted imaging, diffusion tensor imaging, and magnetic resonance spectroscopy are also being developed. With multiplanar capabilities, superior contrast resolution and field of view, magnetic resonance imaging does not have the limitations of sonography, and can provide additional important information. Common indications include ventriculomegaly, callosum and posterior fossa abnormalities, and twin complications. There are safety concerns about magnetic resonance-induced heating and acoustic damage but current literature showed no conclusive evidence of deleterious fetal effects. The American College of Radiology guideline states that pregnant patients can be accepted to undergo magnetic resonance imaging at any stage of pregnancy if risk-benefit ratio to patients warrants that the study be performed. Magnetic resonance imaging of the fetal brain is a safe and powerful adjunct to sonography in prenatal diagnosis. It can provide additional information that aids clinical management, prognostication, and counselling.

  12. Characteristics of mechanically tunable superconductive resonators

    Energy Technology Data Exchange (ETDEWEB)

    Mine, Shigenobu; Terakago, Masafumi; Sakatani, Tomotaka; Hontsu, Shigeki; Nishikawa, Hiroaki [Department of Electronic System and Information Engineering, Faculty of Biology-Oriented Science and Technology, Kinki University, Naga-gun, Wakayama (Japan); Fujimaki, Akira [Department of Quantum Engineering, Nagoya University, Chikusa-ku, Nagoya (Japan); Nakamori, Masaya [Department of Electrical and Information Engineering, Kinki University Technical College, Kumano, Mie (Japan); Tabata, Hitoshi; Kawai, Tomoji [Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka (Japan)

    2002-04-01

    In order to realize superconductive microwave devices with large tuning characteristics, we have studied a mechanically tunable superconductive resonator beneath a dielectric and/or magnetic floating plate (FP) as a first step. The resonator consists of a half-wavelength coplanar waveguide (CPW). The principle of the mechanically tunable method is that variations of the effective permittivity and/or the effective permeability for the microwave waveguide line can be obtained by changing the distance between the resonator and the FP. In computer simulations of electromagnetic fields for the mechanically tunable half-wavelength CPW resonator, we have obtained a large shift of the resonant frequency with a band of 1.75 GHz to 7 GHz (tunability is approximately 25%) using the (La{sub 0.3}Sr{sub 0.7})(Al{sub 0.65}Ta{sub 0.35})O{sub 3} (LSAT) single crystal (dielectric constant ({epsilon}{sub r})=22.8, loss tangent (tan{delta})=1.7x10{sup -4}) as the FP. Based on the results, we have performed an experiment using a half-wavelength CPW resonator made from YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} thin film and the LSAT FP. The result shows a drastic resonant frequency shift of approximately 1.36 GHz (tunability is approximately 20%) when the LSAT FP is moved, using an electromagnetic actuator. In this experiment, it is also noted that the insertion loss is quite low, less than 0.8 dB, compared to previous reports for various tunable filters. Moreover, we have also measured the tuning characteristics with a TiO{sub 2} single crystal ({epsilon}{sub r}=85.4, tan{delta}=2.5x10{sup -4}) as the FP. As a result, we have obtained quite large tuning characteristics of approximately 2 GHz (tunability is approximately 28%). (author)

  13. Resonance region measurements of dysprosium and rhenium

    Science.gov (United States)

    Leinweber, Gregory; Block, Robert C.; Epping, Brian E.; Barry, Devin P.; Rapp, Michael J.; Danon, Yaron; Donovan, Timothy J.; Landsberger, Sheldon; Burke, John A.; Bishop, Mary C.; Youmans, Amanda; Kim, Guinyun N.; Kang, yeong-rok; Lee, Man Woo; Drindak, Noel J.

    2017-09-01

    Neutron capture and transmission measurements have been performed, and resonance parameter analysis has been completed for dysprosium, Dy, and rhenium, Re. The 60 MeV electron accelerator at RPI Gaerttner LINAC Center produced neutrons in the thermal and epithermal energy regions for these measurements. Transmission measurements were made using 6Li glass scintillation detectors. The neutron capture measurements were made with a 16-segment NaI multiplicity detector. The detectors for all experiments were located at ≈25 m except for thermal transmission, which was done at ≈15 m. The dysprosium samples included one highly enriched 164Dy metal, 6 liquid solutions of enriched 164Dy, two natural Dy metals. The Re samples were natural metals. Their capture yield normalizations were corrected for their high gamma attenuation. The multi-level R-matrix Bayesian computer code SAMMY was used to extract the resonance parameters from the data. 164Dy resonance data were analyzed up to 550 eV, other Dy isotopes up to 17 eV, and Re resonance data up to 1 keV. Uncertainties due to resolution function, flight path, burst width, sample thickness, normalization, background, and zero time were estimated and propagated using SAMMY. An additional check of sample-to-sample consistency is presented as an estimate of uncertainty. The thermal total cross sections and neutron capture resonance integrals of 164Dy and Re were determined from the resonance parameters. The NJOY and INTER codes were used to process and integrate the cross sections. Plots of the data, fits, and calculations using ENDF/B-VII.1 resonance parameters are presented.

  14. Lithium-Niobate-Silica Hybrid Whispering-Gallery-Mode Resonators.

    Science.gov (United States)

    Bo, Fang; Wang, Jie; Cui, Jiao; Ozdemir, Sahin Kaya; Kong, Yongfa; Zhang, Guoquan; Xu, Jingjun; Yang, Lan

    2015-12-22

    Lithium-niobate-silica hybrid resonators with quality factors higher than 10(5) are fabricated by depositing a layer of polycrystalline lithium niobate on the flat top surfaces of inverted-wedge silica microdisk resonators. All-optical modulation with improved performance over silica-only resonators and electro-optic modulation not achievable in silica-only resonators are realized in the hybrid resonators. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Periodicity of resonant tunneling current induced by the Stark resonances in semiconductor nanowire

    Science.gov (United States)

    Wołoszyn, M.; Adamowski, J.; Wójcik, P.; Spisak, B. J.

    2013-10-01

    The modification of the electronic current resulting from Stark resonances has been studied for the semiconductor nanowire with the double-barrier structure. Based on the calculated current-voltage characteristics, we have shown that the resonant tunneling current is a periodic function of the width of the spacer layer. We have also demonstrated that the simultaneous change of the source-drain voltage and the voltage applied to the gate located near the nanowire leads to almost periodic changes of the resonant tunneling current as a function of the source-drain and gate voltages. The periodic properties of the resonant tunneling current result from the formation of the Stark resonance states. If we change the electric field acting in the nanowire, the Stark states periodically acquire the energies from the transport window and enhance the tunneling current in a periodic manner. We have found that the separations between the resonant current peaks on the source-drain voltage scale can be described by a slowly increasing linear function of the Stark state quantum number. This allows us to identify the quantum states that are responsible for the enhancement of the resonant tunneling. We have proposed a method of the experimental observation of the Stark resonances in semiconductor double-barrier heterostructures.

  16. Resonator modeling by field tracing: a flexible approach for fully vectorial laser resonator modeling

    Science.gov (United States)

    Asoubar, Daniel; Wyrowski, Frank; Schweitzer, Hagen; Hellmann, Christian; Kuhn, Michael

    2014-05-01

    Nowadays lasers cover a broad spectrum of applications, like laser material processing, metrology and communications. Therefore a broad variety of different lasers, containing various active media and resonator setups, are used to provide high design flexibility. The optimization of such multi-parameter laser setups requires powerful simulation techniques. In literature mainly three practical resonator modeling techniques can be found: Rigorous techniques, e.g. the finite element method (FEM), approximated solutions based on paraxial Gaussian beam tracing by ABCD matrices and the Fox and Li algorithm are used to analyze transversal resonator modes. All of these existing approaches have in common, that only a single simulation technique is used for the whole resonator. In contrast we reformulate the scalar Fox and Li integral equation for resonator eigenmode calculation into a fully vectorial field tracing operator equation. This allows the flexible combination of different modeling techniques in different subdomains of the resonator. The work introduces the basic concepts of field tracing in resonators to calculate vectorial, transversal eigenmodes of stable and unstable resonators.

  17. Theoretical characterization of the collective resonance states underlying the xenon giant dipole resonance

    CERN Document Server

    Chen, Yi-Jen; Karamatskou, Antonia; Santra, Robin

    2015-01-01

    We present a detailed theoretical characterization of the two fundamental collective resonances underlying the xenon giant dipole resonance (GDR). This is achieved consistently by two complementary methods implemented within the framework of the configuration-interaction singles (CIS) theory. The first method accesses the resonance states by diagonalizing the many-electron Hamiltonian using the smooth exterior complex scaling technique. The second method involves a new application of the Gabor analysis to wave-packet dynamics. We identify one resonance at an excitation energy of 74 eV with a lifetime of 27 as, and the second at 107 eV with a lifetime of 11 as. Our work provides a deeper understanding of the nature of the resonances associated with the GDR: a group of close-lying intrachannel resonances splits into two far-separated resonances through interchannel couplings involving the 4d electrons. The CIS approach allows a transparent interpretation of the two resonances as new collective modes. Due to the...

  18. Line with attached segment as a model of Helmholtz resonator: Resonant states completeness

    Directory of Open Access Journals (Sweden)

    I.Y. Popov

    2017-01-01

    Full Text Available Quantum graph consisting of a line with attached segment is considered as a simple model of the Helmholtz resonator. Completeness of resonant states in the space of square integrable functions on the segment is proved. Relation between the completeness and the factorization of the characteristic function in Sz.-Nagy model is discussed.

  19. Experimental Investigation of 2:1 and 3:1 Internal Resonances in Nonlinear MEMS Arch Resonators

    KAUST Repository

    Ramini, Abdallah

    2016-12-05

    We demonstrate experimentally internal resonances in MEMS resonators. The investigation is conducted on in-plane MEMS arch resonators fabricated with a highly doped silicon. The resonators are actuated electrostatically and their stiffness are tuned by electrothermal loading by passing an electrical current though the microstructures. We show that through this tuning, the ratio of the various resonance frequencies can be varied and set at certain ratios. Particularly, we adjust the resonance frequencies of two different vibrational modes to 2:1 and 3:1. Finally, we validate the internal resonances at these ratios through frequency-response curves and FFTs.

  20. Multi-tunable microelectromechanical system (MEMS) resonators

    Energy Technology Data Exchange (ETDEWEB)

    Stalford, Harold L. (Norman, OK); Butler, Michael A. (Andover, MA); Schubert, W. Kent (Albuquerque, NM)

    2006-08-22

    A method for tuning a vibratory device including a cantilevered resonator comprising the steps of increasing a voltage V.sub.0 supplied to the vibratory device to thereby increase the bandwidth of the vibratory device; and keeping the resonant frequency of the vibratory device at substantially that natural frequency of the cantilevered resonator, wherein the vibratory device comprises: a capacitor including a movable plate and a fixed plate spaced from each other, the movable plate being part of the cantilevered resonator; a voltage source connected to the capacitor for providing voltage V.sub.0 across the capacitor to produce an attractive force between movable plate and fixed plate; a circuit connecting the voltage source to the capacitor; and a load resistor in said circuit having a resistance R.sub.L satisfying the following equation: .mu..omega..times..times..lamda. ##EQU00001## where: .mu. is at least 10; .omega..sub.0 is the beam constant for the cantilevered resonator; c.sub.0 is the capacitance for the capacitor; and .lamda. is the voltage dependent coupling parameter for voltage V.sub.0.