Role of depth and location of minima of a double-well potential on vibrational resonance
International Nuclear Information System (INIS)
Rajasekar, S; Jeyakumari, S; Chinnathambi, V; Sanjuan, M A F
2010-01-01
We report our investigation into the role of depth and location of minima of a double-well potential on vibrational resonance in both underdamped and overdamped Duffing oscillators. The systems are driven by both low- and high-frequency periodic forces. We obtain theoretical expressions for the amplitude g of the high-frequency force at which resonances occur. The depth and location of the minima of the potential wells have a distinct effect on vibrational resonance in the underdamped and overdamped cases. In the underdamped system at least one resonance and at most two resonances occur and the number of resonances can be altered by varying the depth and location of the minima of the potential wells. We show that in the overdamped system there is always one and only one resonance, and the value of g at which resonance occurs is independent of the depth of the wells, but varies linearly with the locations of the minima of the wells.
Shape resonances in molecular fields
International Nuclear Information System (INIS)
Dehmer, J.L.
1984-01-01
A shape resonance is a quasibound state in which a particle is temporarily trapped by a potential barrier (i.e., the shape of the potential), through which it may eventually tunnel and escape. This simple mechanism plays a prominent role in a variety of excitation processes in molecules, ranging from vibrational excitation by slow electrons to ionization of deep core levels by x-rays. Moreover, their localized nature makes shape resonances a unifying link between otherwise dissimilar circumstances. One example is the close connection between shape resonances in electron-molecule scattering and in molecular photoionization. Another is the frequent persistence of free-molecule shape resonant behavior upon adsorption on a surface or condensation into a molecular solid. The main focus of this article is a discussion of the basic properties of shape resonances in molecular fields, illustrated by the more transparent examples studied over the last ten years. Other aspects to be discussed are vibrational effects of shape resonances, connections between shape resonances in different physical settings, and examples of shape resonant behavior in more complex cases, which form current challenges in this field
Lim, Ik Soo; Leek, E Charles
2012-07-01
Previous empirical studies have shown that information along visual contours is known to be concentrated in regions of high magnitude of curvature, and, for closed contours, segments of negative curvature (i.e., concave segments) carry greater perceptual relevance than corresponding regions of positive curvature (i.e., convex segments). Lately, Feldman and Singh (2005, Psychological Review, 112, 243-252) proposed a mathematical derivation to yield information content as a function of curvature along a contour. Here, we highlight several fundamental errors in their derivation and in its associated implementation, which are problematic in both mathematical and psychological senses. Instead, we propose an alternative mathematical formulation for information measure of contour curvature that addresses these issues. Additionally, unlike in previous work, we extend this approach to 3-dimensional (3D) shape by providing a formal measure of information content for surface curvature and outline a modified version of the minima rule relating to part segmentation using curvature in 3D shape. Copyright 2012 APA, all rights reserved.
Beucher , Serge
2013-01-01
Implementation of various operators: minima, maxima, extended minima and maxima, dynamics.; The purpose of this document is just to provide additional information about the concepts of maxima and minima in MM. This paper must simply be considered as a clarification of these notions. The notion of dynamics is also addressed. Mamba implementations of the operators are also provided.
Determination of Dimensionless Attenuation Coefficient in Shaped Resonators
Daniels, C.; Steinetz, B.; Finkbeiner, J.; Raman, G.; Li, X.
2003-01-01
The value of dimensionless attenuation coefficient is an important factor when numerically predicting high-amplitude acoustic waves in shaped resonators. Both the magnitude of the pressure waveform and the quality factor rely heavily on this dimensionless parameter. Previous authors have stated the values used, but have not completely explained their methods. This work fully describes the methodology used to determine this important parameter. Over a range of frequencies encompassing the fundamental resonance, the pressure waves were experimentally measured at each end of the shaped resonators. At the corresponding dimensionless acceleration, the numerical code modeled the acoustic waveforms generated in the resonator using various dimensionless attenuation coefficients. The dimensionless attenuation coefficient that most closely matched the pressure amplitudes and quality factors of the experimental and numerical results was determined to be the value to be used in subsequent studies.
International Nuclear Information System (INIS)
Brixner, B.
1981-01-01
The widespread belief that local minima exist in the least squares lens-design error function is not confirmed by the Los Alamos Scientific Laboratory (LASL) optimization program. LASL finds the optimum-mimimum region, which is characterized by small parameter gradients of similar size, small performance improvement per iteration, and many designs that give similar performance. Local minima and unique prescriptions have not been found in many-parameter problems. The reason for these absences is that image errors caused by a change in one parameter can be compensated by changes in the remaining parameters. False local minima have been found, and four cases are discussed
Analysis of acoustic resonator with shape deformation using finite ...
Indian Academy of Sciences (India)
G M KALMSEa, AJAY CHAUDHARIb and P B PATILb a Science College, PB No. 62, Nanded 431603, India b Department of Physics, Dr B A M University, Aurangabad 431 004, India e-mail: bamuaur@bom4.vsnl.net.in. MS received 23 September 1999. Abstract. An acoustic resonator with shape deformation has been ...
Line shapes of atomic-candle-type Rabi resonances
International Nuclear Information System (INIS)
Coffer, J.G.; Camparo, J.C.; Sickmiller, B.; Presser, A.
2002-01-01
When atoms interact with a phase-modulated field, the probability of finding the atom in the excited-state oscillates at the second harmonic of the modulation frequency, 2ω m . The amplitude of this oscillating probability is a resonant function of the Rabi frequency Ω, and this is termed a β Rabi resonance. In this work, we examine the line shape of the β Rabi resonance both theoretically and experimentally. We find that a small-signal theory of the β-Rabi-resonance condition captures much of the line shape's character, and, in particular, that the resonance's 'line Q' (i.e., 2δΩ 1/2 /Ω) is proportional to the modulation frequency. This result can be applied to the atomic candle, where β Rabi resonances are employed to stabilize field strength. Considering our results in the context of developing an optical atomic candle, we find that a free-running diode laser's intensity noise could be improved by orders of magnitude using the atomic candle concept
Effect of the Potential Shape on the Stochastic Resonance Processes
Kenmoé, G. Djuidjé; Ngouongo, Y. J. Wadop; Kofané, T. C.
2015-10-01
The stochastic resonance (SR) induced by periodic signal and white noises in a periodic nonsinusoidal potential is investigated. This phenomenon is studied as a function of the friction coefficient as well as the shape of the potential. It is done through an investigation of the hysteresis loop area which is equivalent to the input energy lost by the system to the environment per period of the external force. SR is evident in some range of the shape parameter of the potential, but cannot be observed in the other range. Specially, variation of the shape potential affects significantly and not trivially the heigh of the potential barrier in the Kramers rate as well as the occurrence of SR. The finding results show crucial dependence of the temperature of occurrence of SR on the shape of the potential. It is noted that the maximum of the input energy generally decreases when the friction coefficient is increased.
Resonance Transport of Graphene Nanoribbon T-Shaped Junctions
International Nuclear Information System (INIS)
Xiao-Lan, Kong; Yong-Jian, Xiong
2010-01-01
We investigate the transport properties of T-shaped junctions composed of armchair graphene nanoribbons of different widths. Three types of junction geometries are considered. The junction conductance strongly depends on the atomic features of the junction geometry. When the shoulders of the junction have zigzag type edges, sharp conductance resonances usually appear in the low energy region around the Dirac point, and a conductance gap emerges. When the shoulders of the junction have armchair type edges, the conductance resonance behavior is weakened significantly, and the metal-metal-metal junction structures show semimetallic behaviors. The contact resistance also changes notably due to the various interface geometries of the junction
Observing shape resonances in ultraslow H^++H elastic scattering
Macek, J. H.; Schultz, D. R.; Ovchinnikov, S. Yu.; Krstic, P. S.
2004-05-01
We have calculated highly accurate elastic and charge transfer cross sections for proton-hydrogen scattering at energies 0.0001-10 eV, using fully quantal approach (P.S. Krstic and D.R. Schultz, J. Phys. B 32, 3485 (1999)). A number of resonances are observed. We calculate the positions and widths of the shape resonances in the effective potentials for various orbital angular momenta (J. H. Macek and S. Yu. Ovchinnikov, Phys. Rev. A 50, 468 (1994)). These correlate well with the observed resonances. We acknowledge support from the US DOE through ORNL, managed by UT-Battelle, LLC under contract DE-AC05-00OR22725.
Maxima and Minima Without Calculus.
Birnbaum, Ian
1982-01-01
Approaches to extrema that do not require calculus are presented to help free maxima/minima problems from the confines of calculus. Many students falsely suppose that these types of problems can only be dealt with through calculus, since few, if any, noncalculus examples are usually presented. (MP)
Effect of resonance line shape on precision measurements of nuclear magnetic resonance shifts
International Nuclear Information System (INIS)
Kachurin, A.M.; Smelyanskij, A.Ya.
1986-01-01
Effect of resonance line shape on the systematic error of precision measurements of nuclear magnetic resonance (NMR) shifts of high resolution (on the center of NMR dispersion line) is analysed. Effect of the device resonance line form-function asymmetry is evaluated; the form-function is determined by configuration of the spectrometer magnetic field and enters the convolution, which describes the resonance line form. It is shown that with the increase of the relaxation line width the form-function effect on the measurement error yields to zero. The form-function effect on measurements and correction of a phase angle of NMR detection is evaluated. The method of semiquantitative evaluation of resonance line and NMR spectrometer parameters, guaranteeing the systematic error of the given infinitesimal, is presented
Shape resonance in K-shell photodetachment from C-
International Nuclear Information System (INIS)
Walter, C. W.; Gibson, N. D.; Bilodeau, R. C.; Berrah, N.; Bozek, J. D.; Ackerman, G. D.; Aguilar, A.
2006-01-01
The core-excited (1s2s 2 2p 4 4 P) negative ion shape resonance of C - near 281.7 eV has been investigated using the merged ion beam--photon beam photodetachment technique on the Advanced Light Source beamline 10.0.1. C + ions formed by double detachment were detected as a function of photon energy. Higher resolution spectra yield more precise values for the energy and width of the resonance than our previous measurements [N. D. Gibson et al., Phys. Rev. A 67, 030703(R) (2003)]. The absolute cross section for double detachment from C - following 1s photoexcitation is measured for the first time and the spectrum is compared to previous theoretical calculations. These measurements also provide information on the lowest core-excited state of neutral carbon (1s2s 2 2p 3 5 S)
The giant resonance and the shape of hot nuclei
Energy Technology Data Exchange (ETDEWEB)
Bracco, A; Camera, F; Million, B; Pignanelli, M [Milan Univ. (Italy). Ist. di Fisica; Gaardhoje, J J; Maj, A; Atac, A [Niels Bohr Inst., Copenhagen (Denmark)
1992-08-01
The gamma decay of the giant dipole resonance is a sensitive tool for investigating how nuclear shape changes with spin and excitation energy, but the information is coded in a subtle way, inasmuch as the shape and orientation of nuclei at finite temperature display large fluctuations. At the time of the conference, the three systems {sup 109-110}Sn, {sup 161-162}Yb and {sup 165-167}Er had recently been studied on the HECTOR spectrometer. The Sn nuclei are spherical in their ground states, and are expected to become oblate under the stress of rotation. The Yb and Er nuclei are prolate, and are expected to become first spherical, then oblate. While the patterns of the measured angular anisotropies are consistent with this general picture, many questions still remain open. 3 refs., 1 tab., 3 figs.
International Nuclear Information System (INIS)
Haeggblom, H.
1968-08-01
The method of calculating the resonance interaction effect by series expansions has been studied. Starting from the assumption that the neutron flux in a homogeneous mixture is inversely proportional to the total cross section, the expression for the flux can be simplified by series expansions. Two types of expansions are investigated and it is shown that only one of them is generally applicable. It is also shown that this expansion gives sufficient accuracy if the approximate resonance line shape function is reasonably representative. An investigation is made of the approximation of the resonance shape function with a Gaussian function which in some cases has been used to calculate the interaction effect. It is shown that this approximation is not sufficiently accurate in all cases which can occur in practice. Then, a rational approximation is introduced which in the first order approximation gives the same order of accuracy as a practically exact shape function. The integrations can be made analytically in the complex plane and the method is therefore very fast compared to purely numerical integrations. The method can be applied both to statistically correlated and uncorrelated resonances
Energy Technology Data Exchange (ETDEWEB)
Haeggblom, H
1968-08-15
The method of calculating the resonance interaction effect by series expansions has been studied. Starting from the assumption that the neutron flux in a homogeneous mixture is inversely proportional to the total cross section, the expression for the flux can be simplified by series expansions. Two types of expansions are investigated and it is shown that only one of them is generally applicable. It is also shown that this expansion gives sufficient accuracy if the approximate resonance line shape function is reasonably representative. An investigation is made of the approximation of the resonance shape function with a Gaussian function which in some cases has been used to calculate the interaction effect. It is shown that this approximation is not sufficiently accurate in all cases which can occur in practice. Then, a rational approximation is introduced which in the first order approximation gives the same order of accuracy as a practically exact shape function. The integrations can be made analytically in the complex plane and the method is therefore very fast compared to purely numerical integrations. The method can be applied both to statistically correlated and uncorrelated resonances.
Li, Yunlong; Oh, Inkyu; Chen, Jiehao; Hu, Yuhang
2018-06-01
Conventional membrane resonators are bulky, and once the geometries and materials are fixed in the fabricated device, the resonators’ characteristics are fixed. In this work, we introduce the active membrane, dielectric elastomer (DE), into the resonator design. Attaching a stiffer passive membrane onto the active DE membrane forms a two-layer system, which generates an out-of-plane deformation when the DE is actuated through a DC voltage applied across the thickness of the DE membrane. When an AC voltage is applied, the two-layer system can generate an out-of-plane oscillation which enables its use as membrane resonators. Both experiments and simulations are carried out to study the dynamic characteristics of the system. The resonant frequencies and mode shapes of the resonator can be tuned through the passive layer properties such as the modulus, thickness, density, and size. The effective stiffness of the DE film changes as the magnitude of the voltage applied on the film changes, which provides an active way to tune the dynamic characteristics of the two-layer resonator even after the device is set. The system is also light weight, low cost, and easy to fabricate, and has great potential in many engineering applications.
Implications of Extended Solar Minima
Adams, Mitzi L.; Davis, J. M.
2009-01-01
Since the discovery of periodicity in the solar cycle, the historical record of sunspot number has been carefully examined, attempting to make predictions about the next cycle. Much emphasis has been on predicting the maximum amplitude and length of the next cycle. Because current space-based and suborbital instruments are designed to study active phenomena, there is considerable interest in estimating the length and depth of the current minimum. We have developed criteria for the definition of a minimum and applied it to the historical sunspot record starting in 1749. In doing so, we find that 1) the current minimum is not yet unusually long and 2) there is no obvious way of predicting when, using our definition, the current minimum may end. However, by grouping the data into 22- year cycles there is an interesting pattern of extended minima that recurs every fourth or fifth 22-year cycle. A preliminary comparison of this pattern with other records, suggests the possibility of a correlation between extended minima and lower levels of solar irradiance.
Shape resonances in low-energy-electron collisions with halopyrimidines
Energy Technology Data Exchange (ETDEWEB)
Barbosa, Alessandra Souza; Bettega, Márcio H. F., E-mail: bettega@fisica.ufpr.br [Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-990 Curitiba, Paraná (Brazil)
2013-12-07
We report calculated cross sections for elastic collisions of low-energy electrons with halopyrimidines, namely, 2-chloro, 2-bromo, and 5-bromopyrimidine. We employed the Schwinger multichannel method with pseudopotentials to compute the cross sections in the static-exchange and static-exchange plus polarization levels of approximation for energies up to 10 eV. We found four shape resonances for each molecule: three of π* nature localized on the ring and one of σ* nature localized along the carbon–halogen bond. We compared the calculated positions of the resonances with the electron transmission spectroscopy data measured by Modelli et al. [J. Phys. Chem. A 115, 10775 (2011)]. In general the agreement between theory and experiment is good. In particular, our results show the existence of a π* temporary anion state of A{sub 2} symmetry for all three halopyrimidines, in agreement with the dissociative electron attachment spectra also reported by Modelli et al. [J. Phys. Chem. A 115, 10775 (2011)].
Influence of the whispering-gallery mode resonators shape on its inertial movement sensitivity
Filatov, Yuri V.; Kukaev, Alexander S.; Shalymov, Egor V.; Venediktov, Vladimir Yu.
2018-01-01
The optical whispering-gallery mode (WGM) resonators are axially symmetrical resonators with smooth edges, supporting the existence of the WGMs by the total internal reflection on the surface of the resonator. As of today, various types of such resonators have been developed, namely the ball shaped, tor shaped, bottle shaped, disk shaped, etc. The movement of WGM resonators in inertial space causes the changes in their shape. The result is a spectral shift of the WGMs. Optical methods allow to register this shift with high precision. It can be used in particular for the measurement of angular velocities in inertial orientation and navigation systems. However, different types of resonators react to the movement in different manners. In addition, their sensitivity to movement can be changed when changing the geometric parameters of these resonators. The work is devoted to investigation of these aspects.
The influence of the whispering gallery modes resonators shape on their sensitivity to the movement
Filatov, Yuri V.; Govorenko, Ekaterina V.; Kukaev, Alexander S.; Shalymov, Egor V.; Venediktov, Vladimir Yu.
2017-05-01
The optical whispering gallery modes resonators are axially symmetrical resonators with smooth edges, supporting the existence of the whispering gallery modes by the total internal reflection on the surface of the resonator. For today various types of such resonators were developed, namely the ball-shaped, tor-shaped, bottle-shaped, disk-shaped etc. The movement of whispering gallery modes resonators in inertial space causes the changes of their shape. The result is a spectral shift of the whispering gallery modes. Optical methods allow to register this shift with high precision. It can be used in particular for the measurement of angular velocities in inertial orientation and navigation systems. However, different types of resonators react to the movement on a miscellaneous. In addition, their sensitivity to movement can be changed when changing the geometric parameters of these resonators. This work is devoted to a research of these aspects.
Mutual Coupling Reduction of E-Shaped MIMO Antenna with Matrix of C-Shaped Resonators
Directory of Open Access Journals (Sweden)
Raghad Ghalib Saadallah Alsultan
2018-01-01
Full Text Available E-shaped multiple-input-multiple-output (MIMO microstrip antenna systems operating in WLAN and WiMAX bands (between 5 and 7.5 GHz are proposed with enhanced isolation features. The systems are comprised of two antennas that are placed parallel and orthogonal to each other, respectively. According to the simulation results, the operating frequency of the MIMO antenna system is 6.3 GHz, and mutual coupling is below −18 dB in a parallel arrangement, whereas they are 6.4 GHz and −25 dB, respectively, in the orthogonal arrangement. The 2 × 3 matrix of C-shaped resonator (CSR is proposed and placed between the antenna elements over the substrate, to reduce the mutual coupling and enhance the isolation between the antennas. More than 30 dB isolation between the array elements is achieved at the resonant frequency for both of the configurations. The essential parameters of the MIMO array such as mutual coupling, surface current distribution, envelop correlation coefficient (ECC, diversity gain (DG, and the total efficiency have been simulated to verify the reliability and the validity of the MIMO system in both parallel and orthogonal configurations. The experimental results are also provided and compared for the mutual coupling with simulated results. An adequate match between the measured and simulated results is achieved.
Use of Green functions in line shape problems in nuclear Magnetic resonance
International Nuclear Information System (INIS)
Martin, M.; Moreno, J.A.
1982-01-01
A method based on the two times Green function formalism is presented. It permits the straightforward determination of the line shape in Magnetic Resonance experiments together with its temperature behavior. Model calculations are made on a two-spin system attached to a one-dimensional rotor obtaining the temperature dependence of its Magnetic Resonance line shape and second moment
International Nuclear Information System (INIS)
Pal, Sourav; Sajeev, Y.; Vaval, Nayana
2006-01-01
The Fock space multi-reference coupled-cluster (FSMRCC) method is used for the study of the shape resonance energy and width in an electron-atom/molecule collision. The procedure is based upon combining a complex absorbing potential (CAP) with FSMRCC theory. Accurate resonance parameters are obtained by solving a small non-Hermitian eigen-value problem. We study the shape resonances in e - -C 2 H 4 and e - -Mg
Liu, Xianchao; Wang, Jun; Li, Ling; Gou, Jun; Zheng, Jie; Huang, Zehua; Pan, Rui
2018-05-01
Mie resonance sphere-lens-lithography has proved to be a good candidate for fabrication of large-area tunable surface nanopattern arrays. Different patterns on photoresist surface are obtained theoretically by adjusting optical coupling among neighboring spheres with different gap sizes. The effect of light reflection from the substrate on the pattern produced on the photoresist with a thin thickness is also discussed. Sub-micron hexagonal star-shaped and ring-shaped patterns arrays are achieved with close-packed spheres arrays and spheres arrays with big gaps, respectively. Changing of star-shaped vertices is induced by different polarization of illumination. Experimental results agree well with the simulation. By using smaller resonance spheres, sub-400 nm star-shaped and ring-shaped patterns can be realized. These tunable patterns are different from results of previous reports and have enriched pattern morphology fabricated by sphere-lens-lithography, which can find application in biosensor and optic devices.
Shape of the Hα emission line in non resonant charge exchange in hydrogen plasmas
International Nuclear Information System (INIS)
Susino Bueno, A.; Zurro Hernandez, B.
1977-01-01
The Hα line shape emitted from a maxwellian hydrogen plasma and produced by non resonant change exchange has been calculated. Its explicit shape depends on the ion temperature, on background neutral energy and on the relative shape of the collision cross section. A comparison between theoretical and experimental shapes of the Hα line is carried out to check the model and to deduce the ion plasma temperature. (author) [es
Mauluidy Soehartono, Alana; Mueller, Aaron David; Tobing, Landobasa Yosef Mario; Chan, Kok Ken; Zhang, Dao Hua; Yong, Ken-Tye
2017-10-01
Strong light localization within metal nanostructures occurs by collective oscillations of plasmons in the form of electric and magnetic resonances. This so-called localized surface plasmon resonance (LSPR) has gained much interest in the development of low-cost sensing platforms in the visible spectrum. However, demonstrations of LSPR-based sensing are mostly limited to electric resonances due to the technological limitations for achieving magnetic resonances in the visible spectrum. In this work, we report the first demonstration of LSPR sensing based on fundamental magnetic resonance in the visible spectrum using ultrasmall gold v-shaped split ring resonators. Specifically, we show the ability for detecting adsorption of bovine serum albumin and cytochrome c biomolecules at monolayer levels, and the selective binding of protein A/G to immunoglobulin G.
Method of shaping fields of controlled extension in a resonator with a large electrical length
International Nuclear Information System (INIS)
Bomko, V.A.; Rudiak, B.I.
A method is discussed for controlling the energy of particles accelerated in a linear accelerator consisting of a volume resonator with drift tubes. Results are described for experimental studies of problems with field shaping of controlled extension of fields in an accelerating structure having drift tubes and a large electrical length. The possibility of shaping the field in a resonator using a stabilizing system of the ''antipode'' type is considered
Resonant infiltration of an opal: Reflection line shape and contribution from in-depth regions.
Maurin, Isabelle; Bloch, Daniel
2015-06-21
We analyze the resonant variation of the optical reflection on an infiltrated artificial opal made of transparent nanospheres. The resonant infiltration is considered as a perturbation in the frame of a previously described one-dimensional model based upon a stratified effective index. We show that for a thin slice of resonant medium, the resonant response oscillates with the position of this slice. We derive that for adequate conditions of incidence angle, this spatially oscillating behavior matches the geometrical periodicity of the opal and hence the related density of resonant infiltration. Close to these matching conditions, the resonant response of the global infiltration varies sharply in amplitude and shape with the incidence angle and polarization. The corresponding resonant reflection originates from a rather deep infiltration, up to several wavelengths or layers of spheres. Finally, we discuss the relationship between the present predictions and our previous observations on an opal infiltrated with a resonant vapor.
Directory of Open Access Journals (Sweden)
Martina Gerken
2013-06-01
Full Text Available Multiferroic composite magnetoelectric (ME sensors are based on the elastic coupling of a magnetostrictive phase and a piezoelectric phase. A deformation of the magnetostrictive phase causes strain in the piezoelectric phase and thus an induced voltage. Such sensors may be applied both for static as well as for dynamic magnetic field measurements. Particularly high sensitivities are achieved for operation at a mechanical resonance. Here, the resonance line shape of layered (2-2 composite cantilever ME sensors at the first bending-mode resonance is investigated theoretically. Finite element method (FEM simulations using a linear material model reveal an asymmetric resonance profile and a zero-response frequency for the ME coefficient. Frequency-dependent strain and electric potential distributions inside the magnetoelectric composite are studied for the case of a magnetostrictive-piezoelectric bilayer. It is demonstrated that a positive or a negative voltage may be induced across the piezoelectric layer depending on the position of the neutral plane. The frequency-dependent induced electric potential is investigated for structured cantilevers that exhibit magnetostriction only at specific positions. For static operation an induced voltage is obtained locally at positions with magnetostriction. In addition to this direct effect a resonance-assisted effect is observed for dynamic operation. Magnetostriction in a limited area of the cantilever causes a global vibration of the cantilever. Thus, deformation of the piezoelectric layer and an induced electric potential also occur in areas of the cantilever without magnetostriction. The direct and the resonance-assisted pathway may induce voltages of equal or of opposite sign. The net induced voltage results from the superposition of the two effects. As the resonance-assisted induced voltage changes sign upon passing the resonance frequency, while the direct component is constant, an asymmetric line
The natural line shape of the giant dipole resonance
International Nuclear Information System (INIS)
Gordon, E.F.; Pitthan, R.
1977-01-01
Investigation of photoabsorption experiments in the spherical nucleus 141 Pr, the quasispherical dynamically deformed 197 Au, and the statically deformed 165 Ho showed that the function which describes best the energy dependence of the reduced transition probability is given by the Breit-Wigner form rather than the Lorentz form. However, the form of the resulting measured cross section is approximately of the Lorentz type. The dependence of the giant resonance width GAMMA on the excitation energy was also investigated, and found to be less than 1% per MeV if one considered the known isovector E2 resonance above the giant dipole resonance. Best fit values of the reduced transition probabilities for the three nuclei are given and compared to (e,e') results. (Auth.)
Shape dependent resonance light scattering properties of gold nanorods
International Nuclear Information System (INIS)
Zhu Jian; Huang Liqing; Zhao Junwu; Wang Yongchang; Zhao Yanrui; Hao Limei; Lu Yimin
2005-01-01
Suspended gold nanorods with mean aspect ratio 2.5 have been synthesized via electrochemical method. Resonance scattering properties have been studied. Two scattering peaks fixed at 400 and 640 nm are due to the scattering of the gold nanorods via coupling to the transverse and longitudinal surface plasmon resonance. The quasi-static calculation results indicate that with the increasing aspect ratio of the nanorods, the longer wavelength scattering peak red shifts linearly and the shorter wavelength peak blue shifts non-linearly. When aspect ratio a/b = 1.0, ellipse degenerate to sphere and the two peaks unite into one peak at 450 nm
Piezoelectric Lead Zirconate Titanate (PZT) Ring Shaped Contour-Mode MEMS Resonators
Kasambe, P. V.; Asgaonkar, V. V.; Bangera, A. D.; Lokre, A. S.; Rathod, S. S.; Bhoir, D. V.
2018-02-01
Flexibility in setting fundamental frequency of resonator independent of its motional resistance is one of the desired criteria in micro-electromechanical (MEMS) resonator design. It is observed that ring-shaped piezoelectric contour-mode MEMS resonators satisfy this design criterion than in case of rectangular plate MEMS resonators. Also ring-shaped contour-mode piezoelectric MEMS resonator has an advantage that its fundamental frequency is defined by in-plane dimensions, but they show variation of fundamental frequency with different Platinum (Pt) thickness referred as change in ratio of fNEW /fO . This paper presents the effects of variation in geometrical parameters and change in piezoelectric material on the resonant frequencies of Platinum piezoelectric-Aluminium ring-shaped contour-mode MEMS resonators and its electrical parameters. The proposed structure with Lead Zirconate Titanate (PZT) as the piezoelectric material was observed to be a piezoelectric material with minimal change in fundamental resonant frequency due to Platinum thickness variation. This structure was also found to exhibit extremely low motional resistance of 0.03 Ω as compared to the 31-35 Ω range obtained when using AlN as the piezoelectric material. CoventorWare 10 is used for the design, simulation and corresponding analysis of resonators which is Finite Element Method (FEM) analysis and design tool for MEMS devices.
Surface vibrational modes in disk-shaped resonators.
Dmitriev, A V; Gritsenko, D S; Mitrofanov, V P
2014-03-01
The natural frequencies and distributions of displacement components for the surface vibrational modes in thin isotropic elastic disks are calculated. In particular, the research is focused on even solutions for low-lying resonant vibrations with large angular wave numbers. Several families of modes are found which are interpreted as modified surface modes of an infinitely long cylinder and Lamb modes of a plate. The results of calculation are compared with the results of the experimental measurements of vibrational modes generated by means of resonant excitation in duraluminum disk with radius of ≈90 mm and thickness of 16 mm in the frequency range of 130-200 kHz. An excellent agreement between the calculated and measured frequencies is found. Measurements of the structure of the resonant peaks show splitting of some modes. About a half of the measured modes has splitting Δfsplit/fmode at the level of the order of 10(-5). The Q-factors of all modes measured in vacuum lie in the interval (2…3)×10(5). This value is typical for duraluminum mechanical resonators in the ultrasonic frequency range. Copyright © 2013 Elsevier B.V. All rights reserved.
Path Minima Queries in Dynamic Weighted Trees
DEFF Research Database (Denmark)
Davoodi, Pooya; Brodal, Gerth Stølting; Satti, Srinivasa Rao
2011-01-01
In the path minima problem on a tree, each edge is assigned a weight and a query asks for the edge with minimum weight on a path between two nodes. For the dynamic version of the problem, where the edge weights can be updated, we give data structures that achieve optimal query time\\todo{what about...
Spectral signature barcodes based on S-shaped Split Ring Resonators (S-SRRs
Directory of Open Access Journals (Sweden)
Herrojo Cristian
2016-01-01
Full Text Available In this paper, it is shown that S-shaped split ring resonators (S-SRRs are useful particles for the implementation of spectral signature (i.e., a class of radiofrequency barcodes based on coplanar waveguide (CPW transmission lines loaded with such resonant elements. By virtue of its S shape, these resonators are electrically small. Hence S-SRRs are of interest for the miniaturization of the barcodes, since multiple resonators, each tuned at a different frequency, are used for encoding purposes. In particular, a 10-bit barcode occupying 1 GHz spectral bandwidth centered at 2.5 GHz, with dimensions of 9 cm2, is presented in this paper.
Experimental verification of the line-shape distortion in resonance Auger spectra
International Nuclear Information System (INIS)
Aksela, S.; Kukk, E.; Aksela, H.; Svensson, S.
1995-01-01
When the mean excitation energy and the width of a broad photon band are varied the Kr 3d 5/2 -1 5p→4p -2 5p resonance Auger electron lines show strong asymmetry and their average kinetic energies shift. Even extra peaks appear. Our results demonstrate experimentally, for the first time, that the incident photon energy distribution has very crucial importance on the resonance Auger line shape and thus on the reliable data analysis of complicated Auger spectra
Dual-band plasmonic resonator based on Jerusalem cross-shaped nanoapertures
Cetin, Arif E.; Kaya, Sabri; Mertiri, Alket; Aslan, Ekin; Erramilli, Shyamsunder; Altug, Hatice; Turkmen, Mustafa
2015-06-01
In this paper, we both experimentally and numerically introduce a dual-resonant metamaterial based on subwavelength Jerusalem cross-shaped apertures. We numerically investigate the physical origin of the dual-resonant behavior, originating from the constituting aperture elements, through finite difference time domain calculations. Our numerical calculations show that at the dual-resonances, the aperture system supports large and easily accessible local electromagnetic fields. In order to experimentally realize the aperture system, we utilize a high-precision and lift-off free fabrication method based on electron-beam lithography. We also introduce a fine-tuning mechanism for controlling the dual-resonant spectral response through geometrical device parameters. Finally, we show the aperture system's highly advantageous far- and near-field characteristics through numerical calculations on refractive index sensitivity. The quantitative analyses on the availability of the local fields supported by the aperture system are employed to explain the grounds behind the sensitivity of each spectral feature within the dual-resonant behavior. Possessing dual-resonances with large and accessible electromagnetic fields, Jerusalem cross-shaped apertures can be highly advantageous for wide range of applications demanding multiple spectral features with strong nearfield characteristics.
International Nuclear Information System (INIS)
Alhassid, Y.; Bush, B.; Yale Univ., New Haven, CT
1990-01-01
The effects of time-dependent shape fluctuations on the giant dipole resonance (GDR) in hot rotating nuclei are investigated. Using the framework of the Landau theory of shape transitions we develop a realistic macroscopic stochastic model to describe the quadrupole time-dependent shape fluctuations and their coupling to the dipole degrees of freedom. In the adiabatic limit the theory reduces to a previous adiabatic theory of static fluctuations in which the GDR cross section is calculated by averaging over the equilibrium distribution with the unitary invariant metric. Nonadiabatic effects are investigated in this model and found to cause structural changes in the resonance cross section and motional narrowing. Comparisons with experimental data are made and deviations from the adiabatic calculations can be explained. In these cases it is possible to determine from the data the damping of the quadrupole motion at finite temperature. (orig.)
Design of a broadband hexagonal-shaped zeroth-order resonance antenna with metamaterials
Energy Technology Data Exchange (ETDEWEB)
Woo, Dong Sik; Kim, Kang Wook; Choi, Hyun Chul [Kyungpook National University, Daegu (Korea, Republic of)
2014-11-15
A broadband hexagonal-shaped metamaterials (MTMs)-based zeroth-order resonant (ZOR) antenna was designed and fabricated. The hexagonal shape of a top patch on a mushroom structure makes not only direct-current paths between the two ends of the patch but also round-current paths along the outside of the patch, thereby widening the resonance frequency of the mushroom MTM antenna. According to the shape of the hexagon patch, the presented antenna achieved impedance bandwidth of 58.6% corresponding to ultra-wideband technology. The proposed ZOR antenna was modeled by utilizing a composite right- and left-handed (CRLH) transmission line and provided 4 to 9.3 dBi of the antenna gain with reduced size as compared to conventional microstrip antennas at Ku- to K-band frequencies.
Far from Equilibrium Percolation, Stochastic and Shape Resonances in the Physics of Life
Directory of Open Access Journals (Sweden)
Antonio Bianconi
2011-10-01
Full Text Available Key physical concepts, relevant for the cross-fertilization between condensed matter physics and the physics of life seen as a collective phenomenon in a system out-of-equilibrium, are discussed. The onset of life can be driven by: (a the critical fluctuations at the protonic percolation threshold in membrane transport; (b the stochastic resonance in biological systems, a mechanism that can exploit external and self-generated noise in order to gain efficiency in signal processing; and (c the shape resonance (or Fano resonance or Feshbach resonance in the association and dissociation processes of bio-molecules (a quantum mechanism that could play a key role to establish a macroscopic quantum coherence in the cell.
Scalable nanofabrication of U-shaped nanowire resonators with tunable optical magnetism.
Zhou, Fan; Wang, Chen; Dong, Biqin; Chen, Xiangfan; Zhang, Zhen; Sun, Cheng
2016-03-21
Split ring resonators have been studied extensively in reconstituting the diminishing magnetism at high electromagnetic frequencies in nature. However, breakdown in the linear scaling of artificial magnetism is found to occur at the near-infrared frequency mainly due to the increasing contribution of self-inductance while reducing dimensions of the resonators. Although alternative designs have enabled artificial magnetism at optical frequencies, their sophisticated configurations and fabrication procedures do not lend themselves to easy implementation. Here, we report scalable nanofabrication of U-shaped nanowire resonators (UNWRs) using the high-throughput nanotransfer printing method. By providing ample area for conducting oscillating electric current, UNWRs overcome the saturation of the geometric scaling of the artificial magnetism. We experimentally demonstrated coarse and fine tuning of LC resonances over a wide wavelength range from 748 nm to 1600 nm. The added flexibility in transferring to other substrates makes UNWR a versatile building block for creating functional metamaterials in three dimensions.
A Near-Threshold Shape Resonance in the Valence-Shell Photoabsorption of Linear Alkynes
Energy Technology Data Exchange (ETDEWEB)
Jacovella, U.; Holland, D. M. P.; Boyé-Péronne, S.; Gans, Bérenger; de Oliveira, N.; Ito, K.; Joyeux, D.; Archer, L. E.; Lucchese, R. R.; Xu, Hong; Pratt, S. T.
2015-12-17
The room-temperature photoabsorption spectra of a number of linear alkynes with internal triple bonds (e.g., 2-butyne, 2-pentyne, and 2- and 3-hexyne) show similar resonances just above the lowest ionization threshold of the neutral molecules. These features result in a substantial enhancement of the photoabsorption cross sections relative to the cross sections of alkynes with terminal triple bonds (e.g., propyne, 1-butyne, 1-pentyne,...). Based on earlier work on 2-butyne [Xu et al., J. Chem. Phys. 2012, 136, 154303], these features are assigned to excitation from the neutral highest occupied molecular orbital (HOMO) to a shape resonance with g (l = 4) character and approximate pi symmetry. This generic behavior results from the similarity of the HOMOs in all internal alkynes, as well as the similarity of the corresponding g pi virtual orbital in the continuum. Theoretical calculations of the absorption spectrum above the ionization threshold for the 2- and 3-alkynes show the presence of a shape resonance when the coupling between the two degenerate or nearly degenerate pi channels is included, with a dominant contribution from l = 4. These calculations thus confirm the qualitative arguments for the importance of the l = 4 continuum near threshold for internal alkynes, which should also apply to other linear internal alkynes and alkynyl radicals. The 1-alkynes do not have such high partial waves present in the shape resonance. The lower l partial waves in these systems are consistent with the broader features observed in the corresponding spectra.
Multi-resonant wideband energy harvester based on a folded asymmetric M-shaped cantilever
Energy Technology Data Exchange (ETDEWEB)
Wu, Meng; Mao, Haiyang; Li, Zhigang; Liu, Ruiwen; Ming, Anjie [Key laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academic of Sciences, Beijing 100029 (China); Ou, Yi; Ou, Wen [Key laboratory of Microelectronics Devices & Integrated Technology, Institute of Microelectronics, Chinese Academic of Sciences, Beijing 100029 (China); Smart Sensor Engineering Center, Jiangsu R& D Center for Internet of Things, Wuxi 214315 (China)
2015-07-15
This article reports a compact wideband piezoelectric vibration energy harvester consisting of three proof masses and an asymmetric M-shaped cantilever. The M-shaped beam comprises a main beam and two folded and dimension varied auxiliary beams interconnected through the proof mass at the end of the main cantilever. Such an arrangement constitutes a three degree-of-freedom vibrating body, which can tune the resonant frequencies of its first three orders close enough to obtain a utility wide bandwidth. The finite element simulation results and the experimental results are well matched. The operation bandwidth comprises three adjacent voltage peaks on account of the frequency interval shortening mechanism. The result shows that the proposed piezoelectric energy harvester could be efficient and adaptive in practical vibration circumstance based on multiple resonant modes.
Multi-resonant wideband energy harvester based on a folded asymmetric M-shaped cantilever
International Nuclear Information System (INIS)
Wu, Meng; Mao, Haiyang; Li, Zhigang; Liu, Ruiwen; Ming, Anjie; Ou, Yi; Ou, Wen
2015-01-01
This article reports a compact wideband piezoelectric vibration energy harvester consisting of three proof masses and an asymmetric M-shaped cantilever. The M-shaped beam comprises a main beam and two folded and dimension varied auxiliary beams interconnected through the proof mass at the end of the main cantilever. Such an arrangement constitutes a three degree-of-freedom vibrating body, which can tune the resonant frequencies of its first three orders close enough to obtain a utility wide bandwidth. The finite element simulation results and the experimental results are well matched. The operation bandwidth comprises three adjacent voltage peaks on account of the frequency interval shortening mechanism. The result shows that the proposed piezoelectric energy harvester could be efficient and adaptive in practical vibration circumstance based on multiple resonant modes
Yang, Jin; Hu, Chuxiong; Zhu, Yu; Wang, Ze; Zhang, Ming
2017-08-01
In this paper, shaping disturbance observer (SDOB) is investigated for precision mechatronic stages with middle-frequency zero/pole type resonance to achieve good motion control performance in practical manufacturing situations. Compared with traditional standard disturbance observer (DOB), in SDOB a pole-zero cancellation based shaping filter is cascaded to the mechatronic stage plant to meet the challenge of motion control performance deterioration caused by actual resonance. Noting that pole-zero cancellation is inevitably imperfect and the controller may even consequently become unstable in practice, frequency domain stability analysis is conducted to find out how each parameter of the shaping filter affects the control stability. Moreover, the robust design criterion of the shaping filter, and the design procedure of SDOB, are both proposed to guide the actual design and facilitate practical implementation. The SDOB with the proposed design criterion is applied to a linear motor driven stage and a voice motor driven stage, respectively. Experimental results consistently validate the effectiveness nature of the proposed SDOB scheme in practical mechatronics motion applications. The proposed SDOB design actually could be an effective unit in the controller design for motion stages of mechanical manufacture equipments.
International Nuclear Information System (INIS)
Uberall, H.; Gaunaurd, G.C.; Tanglis, E.
1983-01-01
The T-matrix approach, which describes the scattering of acoustic waves (or of other waves) from objects of arbitrary shape and geometry, is here 'married' to the resonance scattering theory in order to obtain the (complex) resonance frequencies of an arbitrary shaped target. For the case of nearly impenetrable targets the partial-wave scattering amplitudes are splitted into terms corresponding to 'internal' resonances, plus an apparently nonresonant background amplitude which, however, contains the broad resonances caused by 'external' diffracted (or Franz-type, creeping) waves, in addition to geometrically reflected and refracted (ray) contributions
Research on Bell-Shaped Vibratory Angular Rate Gyro’s Character of Resonator
Directory of Open Access Journals (Sweden)
Hong Liu
2013-04-01
Full Text Available Bell-shaped vibratory angular rate gyro (abbreviated as BVG is a new type Coriolis vibratory gyro that was inspired by Chinese traditional clocks. The resonator fuses based on a variable thickness axisymmetric multicurved surface shell. Its characteristics can directly influence the performance of BVG. The BVG structure not only has capabilities of bearing high overload, high impact and, compared with the tuning fork, vibrating beam, shell and a comb structure, but also a higher frequency to overcome the influence of the disturbance of the exterior environment than the same sized hemispherical resonator gyroscope (HRG and the traditional cylinder vibratory gyroscope. It can be widely applied in high dynamic low precision angular rate measurement occasions. The main work is as follows: the issue mainly analyzes the structure and basic principle, and investigates the bell-shaped resonator’s mathematical model. The reasonable structural parameters are obtained from finite element analysis and an intelligent platform. Using the current solid vibration gyro theory analyzes the structural characteristics and principles of BVG. The bell-shaped resonator is simplified as a paraboloid of the revolution mechanical model, which has a fixed closed end and a free opened end. It obtains the natural frequency and vibration modes based on the theory of elasticity. The structural parameters are obtained from the orthogonal method by the research on the structural parameters of the resonator analysis. It obtains the modal analysis, stress analysis and impact analysis with the chosen parameters. Finally, using the turntable experiment verifies the gyro effect of the BVG.
Feshbach shape resonance for high Tc superconductivity in superlattices of nanotubes
International Nuclear Information System (INIS)
Bianconi, Antonio
2006-01-01
The case of a Feshbach shape resonance in the pairing mechanism for high T c superconductivity in a crystalline lattice of doped metallic nanotubes is described. The superlattice of doped metallic nanotubes provides a superconductor with a strongly asymmetric gap. The disparity and different spatial locations of the wave functions of electrons in different subbands at the Fermi level should suppress the single electron impurity interband scattering giving multiband superconductivity in the clean limit. The Feshbach resonances will arise from the component single-particle wave functions out of which the electron pair wave function is constructed: pairs of wave functions which are time inverse of each other. The Feshbach shape resonance increases the critical temperature by tuning the chemical potential at the Lifshitz electronic topological transition (ETT) where the Fermi surface of one of the bands changes from the one dimensional (1D) to the two dimensional (2D) topology (1D/2D ETT). (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (Abstract Copyright [2006], Wiley Periodicals, Inc.)
Hippocampus shape analysis for temporal lobe epilepsy detection in magnetic resonance imaging
Kohan, Zohreh; Azmi, Reza
2016-03-01
There are evidences in the literature that Temporal Lobe Epilepsy (TLE) causes some lateralized atrophy and deformation on hippocampus and other substructures of the brain. Magnetic Resonance Imaging (MRI), due to high-contrast soft tissue imaging, is one of the most popular imaging modalities being used in TLE diagnosis and treatment procedures. Using an algorithm to help clinicians for better and more effective shape deformations analysis could improve the diagnosis and treatment of the disease. In this project our purpose is to design, implement and test a classification algorithm for MRIs based on hippocampal asymmetry detection using shape and size-based features. Our method consisted of two main parts; (1) shape feature extraction, and (2) image classification. We tested 11 different shape and size features and selected four of them that detect the asymmetry in hippocampus significantly in a randomly selected subset of the dataset. Then, we employed a support vector machine (SVM) classifier to classify the remaining images of the dataset to normal and epileptic images using our selected features. The dataset contains 25 patient images in which 12 cases were used as a training set and the rest 13 cases for testing the performance of classifier. We measured accuracy, specificity and sensitivity of, respectively, 76%, 100%, and 70% for our algorithm. The preliminary results show that using shape and size features for detecting hippocampal asymmetry could be helpful in TLE diagnosis in MRI.
Hajjaj, Amal Z.; Alcheikh, Nouha; Younis, Mohammad I.
2017-01-01
We investigate experimentally and analytically the effect of initial shapes, arc and cosine wave, on the static and dynamic behavior of microelectromechanical systems (MEMS) arch resonators. We show that by carefully choosing the geometrical
International Nuclear Information System (INIS)
Dehmer, J.L.; Dill, D.
1979-01-01
Most of our detailed information on the spectroscopy and dynamics of the electronic continuum of molecules is based on the complementary probes - photoionization and electron scattering. Though usually studied separately, it is most useful to appreciate the connections between these two processes since our understanding of one is often the key to interpreting or even generating new results in the other. We approach this subject in two steps. First, we very briefly outline the well-established connections, e.g., the Bethe-Born theory and comparisons of isoelectronic systems. Then we focus on a point of contact - the role of shape resonances in molecular photoionization and electron-molecule scattering - for which a substantial amount of new information has become available. Specific topics include mapping of resonances from the neutral (hν + molecule) to the negative ion (e + molecule) system, angular distributions, and interaction with vibration
Computing resonant frequency of C-shaped compact microstrip antennas by using ANFIS
Akdagli, Ali; Kayabasi, Ahmet; Develi, Ibrahim
2015-03-01
In this work, the resonant frequency of C-shaped compact microstrip antennas (CCMAs) operating at UHF band is computed by using the adaptive neuro-fuzzy inference system (ANFIS). For this purpose, 144 CCMAs with various relative dielectric constants and different physical dimensions were simulated by the XFDTD software package based on the finite-difference time domain (FDTD) method. One hundred and twenty-nine CCMAs were employed for training, while the remaining 15 CCMAs were used for testing of the ANFIS model. Average percentage error (APE) values were obtained as 0.8413% and 1.259% for training and testing, respectively. In order to demonstrate its validity and accuracy, the proposed ANFIS model was also tested over the simulation data given in the literature, and APE was obtained as 0.916%. These results show that ANFIS can be successfully used to compute the resonant frequency of CCMAs.
Dual and tri-band bandpass filters based on novel Π-shaped resonator
Xiao, Jian-Kang; Zhu, Wen-Jun; Zhao, Wei
2014-05-01
A novel Π-shaped resonator is proposed, and compact dual-band and tri-band bandpass filters that meet IEEE 802.11 application requirements by using the new resonator are designed. The dual-band bandpass filter centres at 2.45 and 5.6 GHz with a simulated passband insertion loss of no more than 0.8 dB, and the tri-band bandpass filter which is got by two-path coupling achieves simulated passband insertion loss of no more than 1.1 dB. The new designs are demonstrated by experiment. The new filters have advantages of simple and compact structures, low passband insertion losses, good frequency selectivity and miniature circuit sizes. All these have prospect to be applied in future wireless communication systems.
Resonant transmission and mode modulation of acoustic waves in H-shaped metallic gratings
International Nuclear Information System (INIS)
Deng, Yu-Qiang; Fan, Ren-Hao; Zhang, Kun; Peng, Ru-Wen; Qi, Dong-Xiang
2015-01-01
In this work, we demonstrate that resonant full transmission of acoustic waves exists in subwavelength H-shaped metallic gratings, and transmission peaks can be efficiently tuned by adjusting the grating geometry. We investigate this phenomenon through both numerical simulations and theoretical calculations based on rigorous-coupled wave analysis. The transmission peaks are originated from Fabry-Perot resonances together with the couplings between the diffractive wave on the surface and the multiple guided modes in the slits. Moreover, the transmission modes can be efficiently tuned by adjusting the cavity geometry, without changing the grating thickness. The mechanism is analyzed based on an equivalent circuit model and verified by both the theoretical calculations and the numerical simulations. This research has potential application in acoustic-device miniaturization over a wide range of wavelengths
Feshbach shape resonance for high Tc pairing in superlattices of quantum stripes and quantum wells
Directory of Open Access Journals (Sweden)
A Bianconi
2006-09-01
Full Text Available The Feshbach shape resonances in the interband pairing in superconducting superlattices of quantum wells or quantum stripes is shown to provide the mechanism for high Tc superconductivity. This mechanism provides the Tc amplification driven by the architecture of material: superlattices of quantum wells (intercalated graphite or diborides and superlattices of quantum stripes (doped high Tc cuprate perovskites where the chemical potential is tuned to a Van Hove-Lifshitz singularity (vHs in the electronic energy spectrum of the superlattice associated with the change of the Fermi surface dimensionality in one of the subbands.
Gap plasmon resonator arrays for unidirectional launching and shaping of surface plasmon polaritons
Energy Technology Data Exchange (ETDEWEB)
Lei, Zeyu; Yang, Tian, E-mail: tianyang@sjtu.edu.cn [State Key Laboratory of Advanced Optical Communication Systems and Networks, Key Laboratory for Thin Film and Microfabrication of the Ministry of Education, UM-SJTU Joint Institute, Shanghai Jiao Tong University, Shanghai 200240 (China)
2016-04-18
We report the design and experimental realization of a type of miniaturized device for efficient unidirectional launching and shaping of surface plasmon polaritons (SPPs). Each device consists of an array of evenly spaced gap plasmon resonators with varying dimensions. Particle swarm optimization is used to achieve a theoretical two-dimensional launching efficiency of about 51%, under the normal illumination of a 5-μm waist Gaussian beam at 780 nm. By modifying the wavefront of the SPPs, unidirectional SPPs with focused, Bessel, and Airy profiles are launched and imaged with leakage radiation microscopy.
Shape of a clamped stiff harpsichord wire driven at a resonant frequency
Hanson, Roger J.; Macomber, Hilliard Kent; Boucher, Mathew A.
2002-05-01
A wire transversely driven by a sinusoidal force at the resonant frequency of a vibrational mode vibrates at the driving frequency and at harmonics generated by nonlinear processes in the wire. If the amplitude of a harmonic is measured as a function of position along the wire, its shape is revealed. It differs significantly from a sinusoid in the vicinity of either end of the wire because the ends are clamped and the wire has significant stiffness. The shapes of various harmonics have been determined for a brass harpsichord wire, 70 cm long, from optical detector measurements made at different distances from a clamped end. Knowledge of shape facilitates the determination of antinode amplitudes of harmonics when the gross motion of the wire is so large that the detectors must be positioned near an end of the wire because of their very limited dynamic range. Some observations of harmonics and related phenomena were reported previously [Hanson et al., J. Acoust Soc. Am. 108, 2592 (2000); 106, 2141 (1999)]. The shape information is also needed to help separate nonlinear effects possibly occurring in the detectors from those of interest, occurring in the wire itself.
Vibrational structures in electron-CO2 scattering below the 2Πu shape resonance
International Nuclear Information System (INIS)
Allan, Michael
2002-01-01
Structures of vibrational origin were discovered in vibrationally inelastic electron-CO 2 cross sections in the energy range 0.4-0.9 eV, well below the 2 Π u shape resonance. They appear in the excitation of higher vibrational levels, in particular the highest members of the Fermi polyads of the type (n, 2m, 0) with n+m=2-4. The lowest two structures, at 0.445 and 0.525 eV, are narrow; higher-lying structures are broader and boomerang-like. The structures are absent when the antisymmetric stretch is co-excited. The structures are interpreted in terms of a wavepacket of the nuclei reflected from a potential surface of the CO 2 - anion in a bent and stretched geometry. A state emerging from the virtual state upon bending and stretching and the state resulting from bending the 2 Π u shape resonance are discussed as possibly being responsible for the structures. (author). Letter-to-the-editor
Rhaphiostylis minima Jongkind (Icacinaceae, a new liana species from Ivory Coast & Liberia
Directory of Open Access Journals (Sweden)
Carel C.H. Jongkind
2015-09-01
Full Text Available A new species of Rhaphiostylis, R. minima sp. nov. from Liberia and Ivory Coast, is described and illustrated here. It is characterised by its comparatively small size, an ovate to lanceolate leaf blade with long drip tip and a partly glabrous ovary that is in shape in between those of R. elegans Engl. and R. preussii Engl. Rhaphiostylis elegans is lectotypified and illustrated here.
Air Damping in a Fan-Shaped Rotational Resonator with Comb Electrodes
Uchida, Yuki; Sugano, Koji; Tsuchiya, Toshiyuki; Tabata, Osamu; Ikehara, Tsuyoshi
We theoretically and experimentally evaluated the damping effect in a rotational resonator with a comb-drive actuator and sensor. The resonator was fabricated from an SOI wafer and has a fan-shaped mass. The underlying substrate was removed using back side deep reactive ion etching. One set of comb electrodes was attached to each side of the mass: one for electrostatic driving and the other for capacitive detection. In our theoretical analysis, the dynamics of the resonator were simplified so that they could be represented by a lumped system. In this lumped system, the damping coefficient was estimated by assuming the damping to be slide film damping and the air flow to be a Stokes flow. The phase shift due to the slide film damping of thick air layers was included in the lumped system. In the experimental evaluation, one side of the rotational combs was removed step-by-step and a half of the mass using a laser trimming tool so that the individual damping effects caused by the comb electrodes and mass could be determined quantitatively. We compared the experimental results with the results of the theoretical analysis and found that the difference in the damping coefficients between the experimental results and results of the theoretical analysis was less than 40%.
Stachiv, I.; Sittner, P.; Olejnicek, J.; Landa, M.; Heller, L.
2017-11-01
Shape memory alloy (SMA) films are very attractive materials for microactuators because of their high energy density. However, all currently developed SMA actuators utilize martensitic transformation activated by periodically generated heating and cooling; therefore, they have a slow actuation speed, just a few Hz, which restricts their use in most of the nanotechnology applications such as high frequency microcantilever based physical and chemical sensors, atomic force microscopes, or RF filters. Here, we design tunable high frequency SMA microcantilevers for nanotechnology applications. They consist of a phase transforming NiTi SMA film sputtered on the common elastic substrate material; in our case, it is a single-crystal silicon. The reversible tuning of microcantilever resonant frequencies is then realized by intentionally changing the Young's modulus and the interlayer stress of the NiTi film by temperature, while the elastic substrate guarantees the high frequency actuation (up to hundreds of kHz) of the microcantilever. The experimental results qualitatively agree with predictions obtained from the dedicated model based on the continuum mechanics theory and a phase characteristic of NiTi. The present design of SMA microcantilevers expands the capability of current micro-/nanomechanical resonators by enabling tunability of several consecutive resonant frequencies.
An unusual π* shape resonance in the near-threshold photoionization of S1 para-difluorobenzene
Bellm, Susan M.; Davies, Julia A.; Whiteside, Paul T.; Guo, Jingwei; Powis, Ivan; Reid, Katharine L.
2005-06-01
Previously reported dramatic changes in photoelectron angular distributions (PADs) as a function of photoelectron kinetic energy following the ionization of S1p-difluorobenzene are shown to be explained by a shape resonance in the b2g symmetry continuum. The characteristics of this resonance are clearly demonstrated by a theoretical multiple-scattering treatment of the photoionization dynamics. New experimental data are presented which demonstrate an apparent insensitivity of the PADs to both vibrational motion and prepared molecular alignment, however, the calculations suggest that strong alignment effects may nevertheless be recognized in the detail of the comparison with experimental data. The apparent, but unexpected, indifference to vibrational excitation is rationalized by considering the nature of the resonance. The correlation of this shape resonance in the continuum with a virtual π* antibonding orbital is considered. Because this orbital is characteristic of the benzene ring, the existence of similar resonances in related substituted benzenes is discussed.
Charge and color breaking minima in supersymmetric models
International Nuclear Information System (INIS)
Brhlik, Michal
2001-01-01
Supersymmetric extensions of the Standard Model include complicated scalar sectors leading to the possible occurrence of non-standard minima along suitable directions in the field space. These minima usually break charge and/or color and their presence in the theory would require an explanation why the universe has settled in the standard electroweak symmetry breaking minimum. In this talk I illustrate the relevance of the charge and color breaking minima in the framework of the minimal supergravity model and a string motivated Horava-Witten scenario
Magnetic Resonance Flow Velocity and Temperature Mapping of a Shape Memory Polymer Foam Device
Energy Technology Data Exchange (ETDEWEB)
Small IV, W; Gjersing, E; Herberg, J L; Wilson, T S; Maitland, D J
2008-10-29
Interventional medical devices based on thermally responsive shape memory polymer (SMP) are under development to treat stroke victims. The goals of these catheter-delivered devices include re-establishing blood flow in occluded arteries and preventing aneurysm rupture. Because these devices alter the hemodynamics and dissipate thermal energy during the therapeutic procedure, a first step in the device development process is to investigate fluid velocity and temperature changes following device deployment. A laser-heated SMP foam device was deployed in a simplified in vitro vascular model. Magnetic resonance imaging (MRI) techniques were used to assess the fluid dynamics and thermal changes associated with device deployment. Spatial maps of the steady-state fluid velocity and temperature change inside and outside the laser-heated SMP foam device were acquired. Though non-physiological conditions were used in this initial study, the utility of MRI in the development of a thermally-activated SMP foam device has been demonstrated.
Hajjaj, Amal Z.
2017-07-19
We investigate experimentally and analytically the effect of initial shapes, arc and cosine wave, on the static and dynamic behavior of microelectromechanical systems (MEMS) arch resonators. We show that by carefully choosing the geometrical parameters and the initial shape of the arch, the veering phenomenon (avoided-crossing) among the first two symmetric modes can be strongly activated. To demonstrate this, we study electrothermally tuned and electrostatically driven initially curved MEMS resonators. Upon changing the electrothermal voltage, we demonstrate high frequency tunability of arc resonators compared to the cosine-configuration resonators for the first and third resonance frequencies. For arc beams, we show that the first resonance frequency increases up to twice its fundamental value and the third resonance frequency decreases until getting very close to the first resonance frequency triggering the veering phenomenon. Around the veering regime, we study experimentally and analytically the dynamic behavior of the arc beam for different electrostatic loads. The analytical study is based on a reduced order model of a nonlinear Euler–Bernoulli shallow arch beam model. The veering phenomenon is also confirmed through a finite-element multi-physics and nonlinear model.
International Nuclear Information System (INIS)
Paulo, A S; GarcIa-Sanchez, D; Perez-Murano, F; Bachtold, A; Black, J; Bokor, J; Esplandiu, M J; Aguasca, A
2008-01-01
We describe a method based on the use of higher order bending modes of the cantilever of a dynamic force microscope to characterize vibrations of micro and nanomechanical resonators at arbitrarily large resonance frequencies. Our method consists on using a particular cantilever eigenmode for standard feedback control in amplitude modulation operation while another mode is used for detecting and imaging the resonator vibration. In addition, the resonating sample device is driven at or near its resonance frequency with a signal modulated in amplitude at a frequency that matches the resonance of the cantilever eigenmode used for vibration detection. In consequence, this cantilever mode is excited with an amplitude proportional to the resonator vibration, which is detected with an external lock-in amplifier. We show two different application examples of this method. In the first one, acoustic wave vibrations of a film bulk acoustic resonator around 1.6 GHz are imaged. In the second example, bending modes of carbon nanotube resonators up to 3.1 GHz are characterized. In both cases, the method provides subnanometer-scale sensitivity and the capability of providing otherwise inaccessible information about mechanical resonance frequencies, vibration amplitude values and mode shapes
Energy Technology Data Exchange (ETDEWEB)
Barbosa, Alessandra Souza [Departamento de Física, Universidade Federal do Paraná, CP 19044, 81531-990 Curitiba, Paraná (Brazil); Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Varella, Márcio T. do N. [Instituto de Física, Universidade de São Paulo, Rua do Matão 1731, 05508-090 São Paulo, SP (Brazil); Sanchez, Sergio d’A.; Bettega, Márcio H. F., E-mail: bettega@fisica.ufpr.br [Departamento de Física, Universidade Federal do Paraná, CP 19044, 81531-990 Curitiba, Paraná (Brazil); Ameixa, João; Limão-Vieira, Paulo; Ferreira da Silva, Filipe [Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Blanco, Francisco [Departamento de Física Atómica, Molecular y Nuclear, Facultad de Ciencias Físicas, Universidad Complutense de Madrid, E-28040 Madrid (Spain); and others
2016-08-28
In this work, we report theoretical and experimental cross sections for elastic scattering of electrons by chlorobenzene (ClB). The theoretical integral and differential cross sections (DCSs) were obtained with the Schwinger multichannel method implemented with pseudopotentials (SMCPP) and the independent atom method with screening corrected additivity rule (IAM-SCAR). The calculations with the SMCPP method were done in the static-exchange (SE) approximation, for energies above 12 eV, and in the static-exchange plus polarization approximation, for energies up to 12 eV. The calculations with the IAM-SCAR method covered energies up to 500 eV. The experimental differential cross sections were obtained in the high resolution electron energy loss spectrometer VG-SEELS 400, in Lisbon, for electron energies from 8.0 eV to 50 eV and angular range from 7{sup ∘} to 110{sup ∘}. From the present theoretical integral cross section (ICS) we discuss the low-energy shape-resonances present in chlorobenzene and compare our computed resonance spectra with available electron transmission spectroscopy data present in the literature. Since there is no other work in the literature reporting differential cross sections for this molecule, we compare our theoretical and experimental DCSs with experimental data available for the parent molecule benzene.
Gong, Jianxiao; Zhou, Fei; Li, Zhiyuan; Tang, Zhiyong
2012-06-19
We have synthesized Au@Ag core-shell nanocubes containing Au cores with varying shapes and sizes through modified seed-mediated methods. Bromide ions are found to be crucial in the epitaxial growth of Ag atoms onto Au cores and in the formation of the shell's cubic shape. The Au@Ag core-shell nanocubes exhibit very abundant and distinct localized surface plasmon resonance (LSPR) properties, which are core-shape and size-dependent. With the help of theoretical calculation, the physical origin and the resonance mode profile of each LSPR peak are identified and studied. The core-shell nanocrystals with varying shaped cores offer a new rich category for LSPR control through the plasmonic coupling effect between core and shell materials.
International Nuclear Information System (INIS)
Vijayakumar, C.; Bhargava, Sunil; Gharpure, Damayanti Chandrashekhar
2008-01-01
A novel Neuro - level set shape detection algorithm is proposed and evaluated for segmentation and grading of brain tumours. The algorithm evaluates vascular and cellular information provided by dynamic contrast susceptibility magnetic resonance images and apparent diffusion coefficient maps. The proposed neural shape detection algorithm is based on the levels at algorithm (shape detection algorithm) and utilizes a neural block to provide the speed image for the level set methods. In this study, two different architectures of level set method have been implemented and their results are compared. The results show that the proposed Neuro-shape detection performs better in differentiating the tumor, edema, necrosis in reconstructed images of perfusion and diffusion weighted magnetic resonance images. (author)
Yang, Jing; Zhang, Jiasen
2013-04-08
We propose a nano-polarization-converter made of a resonant L-shaped slot antenna in a gold film and study its optical properties using the finite-difference time-domain method. Phase retardation between the fast and slow axes of the nano-polarization-converter originates from the simultaneous excitation of both single-surface first-order magnetic plasmon resonance mode and second-order magnetic plasmon resonance mode at the working wavelength. By adjusting the size of the slot antenna, which is still much smaller than the wavelength, the working wavelength can be tuned within a large wavelength range.
International Nuclear Information System (INIS)
Ruiz-Díez, V; Hernando-García, J; Toledo, J; Manzaneque, T; Sánchez-Rojas, J L; Kucera, M; Pfusterschmied, G; Schmid, U
2016-01-01
In this work, roof tile-shaped modes of MEMS (micro electro-mechanical systems) cantilever resonators with various geometries and mode orders are analysed. These modes can be efficiently excited by a thin piezoelectric film and a properly designed top electrode. The electrical and optical characterization of the resonators are performed in liquid media and the device performance is evaluated in terms of quality factor, resonant frequency and motional conductance. A quality factor as high as 165 was measured in isopropanol for a cantilever oscillating in the seventh order roof tile-shaped mode at 2 MHz. To support the results of the experimental characterization, a 2D finite element method simulation model is presented and studied. An analytical model for the estimation of the motional conductance was also developed and validated with the experimental measurements. (paper)
FPSPH DFPSPF, Line Shape Function for Doppler Broadened Resonance Cross-Sections Calculation
International Nuclear Information System (INIS)
Ribon, P.
1982-01-01
1 - Description of problem or function: In the computation of Doppler- broadened resonance cross sections, use is made of the symmetric and anti-symmetric line shape functions. These functions usually denoted as Psi and Phi (Psi and Chi in Anglo-Saxon formalism) are defined in terms of the real and imaginary parts of the error function for complex arguments. They are the product of the convolution of a Gaussian function with the symmetric and anti-symmetric Breit-Wigner functions, respectively. FPSPH and DFPSPH compute these functions. 2 - Method of solution: For (1+x 2 ) > 20 Beta 2 , the calculation is based upon the asymptotic expansion: Psi+(i*Phi) = 1/(1-ix)*(1-t+3t 2 -3.5t 3 +3.5+7t 4 ---), with: t = 1/(2z 2 ); z = (1-ix)/Beta. The half-plane (Beta,x) is split in several parts, and use is made of PADE approximants. For 1 + x 2 2 , the calculation is based upon the relation with the erf function: Psi + i*Phi = SQRT(Pi)/Beta*(e (z 2 ) )*(1-erf(z)) (z = (1-ix)/Beta, and erf(z) being calculated from its analytic expansion: erf(z) = 2/SQRT(Pi)*z*e (-z 2 ) *(1+z 2 /3+z 4 /(3*5) + z 6 /(3*5*7)+---). PADE approximants are used to compute the expansion and e z 2
A novel L-shaped linear ultrasonic motor operating in a single resonance mode
Zhang, Bailiang; Yao, Zhiyuan; Liu, Zhen; Li, Xiaoniu
2018-01-01
In this study, a large thrust linear ultrasonic motor using an L-shaped stator is described. The stator is constructed by two mutually perpendicular rectangular plate vibrators, one of which is mounted in parallel with the slider to make the motor structure to be more compact. The symmetric and antisymmetric modes of the stator based on the first order bending vibration of two vibrators are adopted, in which each resonance mode is assigned to drive the slider in one direction. The placement of piezoelectric ceramics in a stator could be determined by finite element analysis, and the influence of slots in the head block on the vibration amplitudes of driving foot was studied as well. Three types of prototypes (non-slotted, dual-slot, and single-slot) were fabricated and experimentally investigated. Experimental results demonstrated that the prototype with one slot exhibited the best mechanical output performance. The maximum loads under the excitation of symmetric mode and antisymmetric mode were 65 and 90 N, respectively.
Effect of non-ideal clamping shape on the resonance frequencies of silicon nanocantilevers
Energy Technology Data Exchange (ETDEWEB)
Guillon, Samuel; Saya, Daisuke; Mazenq, Laurent; Nicu, Liviu [CNRS, LAAS, 7 Avenue du Colonel Roche, F-31077 Toulouse Cedex 4 (France); Perisanu, Sorin; Vincent, Pascal [LPMCN, Universite Claude Bernard Lyon 1 et CNRS, 43 boulevard du 11 novembre 1918, 69622 Villeurbanne Cedex (France); Lazarus, Arnaud; Thomas, Olivier, E-mail: sguillon@laas.fr [Structural Mechanics and Coupled Systems Laboratory, Conservatoire National des Arts et Metiers, 2 rue Conte, 75003 Paris (France)
2011-06-17
In this paper, we investigate the effects of non-ideal clamping shapes on the dynamic behavior of silicon nanocantilevers. We fabricated silicon nanocantilevers using silicon on insulator (SOI) wafers by employing stepper ultraviolet (UV) lithography, which permits a resolution of under 100 nm. The nanocantilevers were driven by electrostatic force inside a scanning electron microscope (SEM). Both lateral and out-of-plane resonance frequencies were visually detected with the SEM. Next, we discuss overhanging of the cantilever support and curvature at the clamping point in the silicon nanocantilevers, which generally arises in the fabrication process. We found that the fundamental out-of-plane frequency of a realistically clamped cantilever is always lower than that for a perfectly clamped cantilever, and depends on the cantilever width and the geometry of the clamping point structure. Using simulation with the finite-elements method, we demonstrate that this discrepancy is attributed to the particular geometry of the clamping point (non-zero joining curvatures and a flexible overhanging) that is obtained in the fabrication process. The influence of the material orthotropy is also investigated and is shown to be negligible.
International Nuclear Information System (INIS)
Burgt, P.J.M. van der; Eck, J. van; Heideman, H.G.M.
1986-01-01
Optical excitation functions of singly excited helium states are presented, measured by detecting the yield of emitted photons as a function of the incident electron energy from 56 to 66 eV. Many structures are observed, which are caused by negative-ion resonances and by the decay of autoionising states followed by post-collision interaction. Some of the structures are interpreted as being caused by hitherto unknown shape resonances lying very close to the thresholds of a particular class of autoionising states. As these shape resonances almost exclusively decay to their respective parent (autoionising) states, thereby considerably enhancing the threshold excitation cross sections of these states, they can only be observed via the PCI effect on the excitation functions of (higher lying) singly excited states. Using the recently introduced supermultiplet classification for doubly excited states a selection rule for the near-threshold excitation of doubly excited states by electron impact is deduced from the measurements. Only states with large probabilities in the Wannier region of configuration space (where the two electrons are at nearly equal distances and on opposite sides of the nucleus) are strongly excited. It is pointed out that these states are precisely the states that can support the above mentioned shape resonances at their thresholds. (author)
Pulskamp, Jeffrey S; Bedair, Sarah S; Polcawich, Ronald G; Smith, Gabriel L; Martin, Joel; Power, Brian; Bhave, Sunil A
2012-05-01
This paper reports theoretical analysis and experimental results on a numerical electrode shaping design technique that permits the excitation of arbitrary modes in arbitrary geometries for piezoelectric resonators, for those modes permitted to exist by the nonzero piezoelectric coefficients and electrode configuration. The technique directly determines optimal electrode shapes by assessing the local suitability of excitation and detection electrode placement on two-port resonators without the need for iterative numerical techniques. The technique is demonstrated in 61 different electrode designs in lead zirconate titanate (PZT) thin film on silicon RF micro electro-mechanical system (MEMS) plate, beam, ring, and disc resonators for out-of-plane flexural and various contour modes up to 200 MHz. The average squared effective electromechanical coupling factor for the designs was 0.54%, approximately equivalent to the theoretical maximum value of 0.53% for a fully electroded length-extensional mode beam resonator comprised of the same composite. The average improvement in S(21) for the electrode-shaped designs was 14.6 dB with a maximum improvement of 44.3 dB. Through this piezoelectric electrodeshaping technique, 95% of the designs showed a reduction in insertion loss.
V-shaped resonators for addition of broad-area laser diode arrays
Liu, Bo; Liu, Yun; Braiman, Yehuda Y.
2012-12-25
A system and method for addition of broad-area semiconductor laser diode arrays are described. The system can include an array of laser diodes, a V-shaped external cavity, and grating systems to provide feedback for phase-locking of the laser diode array. A V-shaped mirror used to couple the laser diode emissions along two optical paths can be a V-shaped prism mirror, a V-shaped stepped mirror or include multiple V-shaped micro-mirrors. The V-shaped external cavity can be a ring cavity. The system can include an external injection laser to further improve coherence and phase-locking.
Origin of the resistivity minima in granular superconductors
International Nuclear Information System (INIS)
Simanek, E.
1982-01-01
The recently observed minima in the temperature dependence of the electrical resistivity of a granular superconductor are explained with use of a percolation model of a disordered granular array, which takes into account the electrostatic charging energy. The thermally activated tunneling of Cooper pairs is shown to play an important role in the interpretation of the experimental data on tin films
On the Local Minima of the Order of Appearance Function
Directory of Open Access Journals (Sweden)
Florian Luca
2015-01-01
Full Text Available The order of appearance z(n of the positive integer n is the smallest positive integer k such that n divides Fk, the kth member of the Fibonacci sequence. In this paper, we improve upon some results from (Marques, 2011 concerning local minima of z(n.
3-D Printed Fabry–Pérot Resonator Antenna with Paraboloid-Shape Superstrate for Wide Gain Bandwidth
Directory of Open Access Journals (Sweden)
Qiang Chen
2017-11-01
Full Text Available A three-dimensional (3-D printed Fabry–Pérot resonator antenna (FPRA, which designed with a paraboloid-shape superstrate for wide gain bandwidth is proposed. In comparison with the commonly-adopted planar superstrate, the paraboloid-shape superstrate is able to provide multiple resonant heights and thus satisfy the resonant condition of the FPRA in a wide frequency band. A FPRA working at 6 GHz is designed, fabricated, and tested. Considering the fabrication difficulty caused by its complex structure, the prototype antenna was fabricated by using the 3-D printing technology, i.e., all components of the prototype antenna were printed with photopolymer resin and then treated by the surface metallization process. Measurement results agree well with the simulation results, and show the 3-D printed FPRA has a |S11| < −10 dB impedance bandwidth of 12.4%, and a gain of 16.8 dBi at its working frequency of 6 GHz. Moreover, in comparison with the planar superstrate adopted in traditional FPRAs, the paraboloid-shape superstrate of the proposed FPRA significantly improves the 3-dB gain bandwidth from 6% to 22.2%.
Optimizer convergence and local minima errors and their clinical importance
International Nuclear Information System (INIS)
Jeraj, Robert; Wu, Chuan; Mackie, Thomas R
2003-01-01
Two of the errors common in the inverse treatment planning optimization have been investigated. The first error is the optimizer convergence error, which appears because of non-perfect convergence to the global or local solution, usually caused by a non-zero stopping criterion. The second error is the local minima error, which occurs when the objective function is not convex and/or the feasible solution space is not convex. The magnitude of the errors, their relative importance in comparison to other errors as well as their clinical significance in terms of tumour control probability (TCP) and normal tissue complication probability (NTCP) were investigated. Two inherently different optimizers, a stochastic simulated annealing and deterministic gradient method were compared on a clinical example. It was found that for typical optimization the optimizer convergence errors are rather small, especially compared to other convergence errors, e.g., convergence errors due to inaccuracy of the current dose calculation algorithms. This indicates that stopping criteria could often be relaxed leading into optimization speed-ups. The local minima errors were also found to be relatively small and typically in the range of the dose calculation convergence errors. Even for the cases where significantly higher objective function scores were obtained the local minima errors were not significantly higher. Clinical evaluation of the optimizer convergence error showed good correlation between the convergence of the clinical TCP or NTCP measures and convergence of the physical dose distribution. On the other hand, the local minima errors resulted in significantly different TCP or NTCP values (up to a factor of 2) indicating clinical importance of the local minima produced by physical optimization
Yan, Haitao; Han, Daofu; Li, Ming; Lin, Bo
2017-01-01
This paper presents the design, fabrication, and characterization of a D-shaped fiber coated with polyvinyl alcohol (PVA) embedding an Au grating-based relative humidity (RH) sensor. The Au grating is fabricated on a D-shaped fiber to match the wave-vector and excite the surface plasmon, and the PVA is embedded in the Au grating as a sensitive cladding film. The refractive index of PVA changes with the ambient humidity. Measurements in a controlled environment show that the RH sensor can achieve a sensitivity of 5.4 nm per relative humidity unit in the RH range from 0% to 70% RH. Moreover, the surface plasmon resonance can be realized and used for RH sensing at the C band of optical fiber communication instead of the visible light band due to the metallic grating microstructure on the D-shaped fiber.
International Nuclear Information System (INIS)
Minkin, A.V.; Tsarevskij, S.L.
2006-01-01
For high-temperature superconductors the shape of a NMR spectrum line is built regarding for variation of inhomogeneity of irregular vortex lattice magnetic field near superconductor surface. It is shown that the shape of a NMR line is not simply widened but noticeably varies depending on the degree of irregularity of a superconductor vortex lattice. This variation is associated with a local symmetry decrease in an irregular vortex lattice of the superconductor. Taking into account these circumstances may considerably change conclusions about the type of a vortex lattice and superconductor parameters which are commonly gained from NMR line shape analysis [ru
International Nuclear Information System (INIS)
Lu Liu; Xu Xiaoliang; Shi Chaoshu; Ming Hai
2010-01-01
Localized surface plasmon resonance (LSPR) enhanced photoluminescences (PL) from CdSe quantum dots (QDs) on worm-like or quasi-spherical silver colloids have been investigated. The shape of silver colloid film is controlled by annealing temperature (200 o C∼350 o C). Strong PL enhancements of CdSe QDs on both as-grown and annealed silver colloid films are observed. The results show that the PL enhancement factor of CdSe QDs on worm-like silver colloid film reaches as high as 15-fold. Moreover, the enhancement factor is 5 times larger than that obtained from the quasi-spherical silver colloids. The superiority of worm-like silver nanostructure on LSPR enhanced photoluminescence is attributed to its larger size, hot spots and multiple dipole resonance modes coupling, which are induced by aggregation effect.
Jost, Gregor; Endrikat, Jan; Pietsch, Hubertus
2017-01-01
To compare injector-based contrast agent (CA) administration with hand injection in magnetic resonance angiography (MRA). Gadobutrol was administered in 6 minipigs with 3 protocols: (a) hand injection (one senior technician), (b) hand injection (6 less-experienced technicians), and (c) power injector administration. The arterial bolus shape was quantified by test bolus measurements. A head and neck MRA was performed for quantitative and qualitative comparison of signal enhancement. A significantly shorter time to peak was observed for protocol C, whereas no significant differences between protocols were found for peak height and bolus width. However, for protocol C, these parameters showed a much lower variation. The MRA revealed a significantly higher signal-to-noise ratio for injector-based administration. A superimposed strong contrast of the jugular vein was found in 50% of the hand injections. Injector-based CA administration results in a more standardized bolus shape, a higher vascular contrast, and a more robust visualization of target vessels.
Prabhakar, Amit; Mukherji, Soumyo
2010-12-21
In this study, a novel embedded optical waveguide based sensor which utilizes localized surface plasmon resonance of gold nanoparticles coated on a C-shaped polymer waveguide is being reported. The sensor, as designed, can be used as an analysis chip for detection of minor variations in the refractive index of its microenvironment, which makes it suitable for wide scale use as an affinity biosensor. The C-shaped waveguide coupled with microfluidic channel was fabricated by single step patterning of SU8 on an oxidized silicon wafer. The absorbance due to the localized surface plasmon resonance (LSPR) of SU8 waveguide bound gold nano particle (GNP) was found to be linear with refractive index changes between 1.33 and 1.37. A GNP coated C-bent waveguide of 200 μ width with a bend radius of 1 mm gave rise to a sensitivity of ~5 ΔA/RIU at 530 nm as compared to the ~2.5 ΔA/RIU (refractive index units) of the same dimension bare C-bend SU8 waveguide. The resolution of the sensor probe was ~2 × 10(-4) RIU.
Nuclear magnetic resonance line-shape analysis and determination of exchange rates
International Nuclear Information System (INIS)
Rao, B.D.
1989-01-01
The fact that chemical exchange processes occur at rates that cover a broad range and produce readily detectable effects on the spectrum is one of the attractive features of high-resolution NMR. The description of these line shapes in the presence of spin-spin coupling requires the density matrix theory which is rather complex. Analysis of the line shapes usually needs computer simulations and is capable of providing reliable information on the exchange rates as well as spectral parameters in the absence of exchange. Simplified procedures, ignoring spin-spin coupling, often result in deviations in these exchange and spectral parameters determined. A step-by-step procedure is detailed in this chapter for setting up the matrices required for computing the line shapes of exchanges involving weakly coupled spin systems on the basis of the density matrix theory without the need for a detailed understanding of the theory. A knowledge of the energy level structure and allowed transitions in the NMR spectra of the individual weakly coupled spin systems is all that is required. The procedure is amenable to numerical computation. The group of illustrative examples chosen to demonstrate the development of the computational tools cover some of the commonly encountered cases of exchange from simple systems to rather complex ones. Such exchanges occur frequently in biological molecules, especially those involving enzyme-substrate complexes. In cases where the experimental line shapes are obtained with respectable precision, and the relevant exchange processes are unambiguously identifiable, the computer simulation method of line-shape analysis is capable of providing useful and incisive information. The example of the 31P exchanges in the adenylate kinase is illustrative of this point
International Nuclear Information System (INIS)
Galbraith, H.W.; Dubs, M.; Steinfeld, J.I.
1982-01-01
We calculate the steady-state probe absorption line-shape function for a strongly driven, Zeeman-degenerate molecular system. The probe laser is treated to lowest order while the pump laser is dealt with to all orders. We obtain the probe line shape for the cases of parallel and perpendicular linear polarization of the two lasers. As expected, the effects of M degeneracy, as well as differences due to the relative laser polarizations, are most pronounced when Doppler broadening is not important. However, even in the presence of large Doppler broadening we find a narrowing of the population hole by including the Zeeman degeneracy and a further narrowing if perpendicular laser polarizations are used
The Multiple-Minima Problem in Protein Folding
Scheraga, Harold A.
1991-10-01
The conformational energy surface of a polypeptide or protein has many local minima, and conventional energy minimization procedures reach only a local minimum (near the starting point of the optimization algorithm) instead of the global minimum (the multiple-minima problem). Several procedures have been developed to surmount this problem, the most promising of which are: (a) build up procedure, (b) optimization of electrostatics, (c) Monte Carlo-plus-energy minimization, (d) electrostatically-driven Monte Carlo, (e) inclusion of distance restraints, (f) adaptive importance-sampling Monte Carlo, (g) relaxation of dimensionality, (h) pattern-recognition, and (i) diffusion equation method. These procedures have been applied to a variety of polypeptide structural problems, and the results of such computations are presented. These include the computation of the structures of open-chain and cyclic peptides, fibrous proteins and globular proteins. Present efforts are being devoted to scaling up these procedures from small polypeptides to proteins, to try to compute the three-dimensional structure of a protein from its amino sequence.
Meyer, Dominik C; Rahm, Stefan; Farshad, Mazda; Lajtai, Georg; Wieser, Karl
2013-08-19
It seems appropriate to assume, that for a full and strong global shoulder function a normally innervated and active deltoid muscle is indispensable. We set out to analyse the size and shape of the deltoid muscle on MR-arthrographies, and analyse its influence on shoulder function and its adaption (i.e. atrophy) for reduced shoulder function. The fatty infiltration (Goutallier stages), atrophy (tangent sign) and selective myotendinous retraction of the rotator cuff, as well as the thickness and the area of seven anatomically defined segments of the deltoid muscle were measured on MR-arthrographies and correlated with shoulder function (i.e. active abduction). Included were 116 patients, suffering of a rotator cuff tear with shoulder mobility ranging from pseudoparalysis to free mobility. Kolmogorov-Smirnov test was used to determine the distribution of the data before either Spearman or Pearson correlation and a multiple regression was applied to reveal the correlations. Our developed method for measuring deltoid area and thickness showed to be reproducible with excellent interobserver correlations (r = 0.814-0.982).The analysis of influencing factors on active abduction revealed a weak influence of the amount of SSP tendon (r = -0.25; p muscle retraction (r = -0.27; p muscle infiltration (GFDI: r = -0.36; p muscle shape with the degree of active glenohumeral abduction. Furthermore, long-standing rotator cuff tears did not appear to influence the deltoid shape, i.e. did not lead to muscle atrophy. Our data support that in chronic rotator cuff tears, there seems to be no disadvantage to exhausting conservative treatment and to delay implantation of reverse total shoulder arthroplasty, as the shape of deltoid muscle seems only to be influenced by natural aging, but to be independent of reduced shoulder motion.
Processing of complex shapes with single-mode resonant frequency microwave applicators
International Nuclear Information System (INIS)
Fellows, L.A.; Delgado, R.; Hawley, M.C.
1994-01-01
Microwave processing is an alternative to conventional composite processing techniques. Single-mode microwave applicators efficiently couple microwave energy into the composite. The application of the microwave energy is greatly affected by the geometry of the composite. In the single mode microwave applicator, two types of modes are available. These modes are best suited to processing flat planar samples or cylindrical samples with geometries that align with the electric fields. Mode-switching is alternating between different electromagnetic modes with the intelligent selection of the modes to alleviate undesirable temperature profiles. This method has improved the microwave heating profiles of materials with complex shapes that do not align with either type of electric field. Parts with two different complex geometries were fabricated from a vinyl toluene/vinyl ester resin with a continuous glass fiber reinforcement by autoclaving and by microwave techniques. The flexural properties of the microwave processed samples were compared to the flexural properties of autoclaved samples. The trends of the mechanical properties for the complex shapes were consistent with the results of experiments with flat panels. This demonstrated that mode-switching techniques are as applicable for the complex shapes as they are for the simpler flat panel geometry
Zhang, Weiwei; Serna, Samuel; Le Roux, Xavier; Vivien, Laurent; Cassan, Eric
2016-05-01
breakthrough of the performance of slot ring resonator sensing ability. Different from the normal sensing regime by monitoring one specific resonance (λres) peak shift, the proposed approach stems from the sensitivity of the RR critical coupling. The critical coupling peak is auto-selected out by matching the following condition: the ring resonator's round trip attenuation coefficient a(λ) being equal to the coupler self-coupling coefficient k(λ), thus resulting in the deepest extinction ratio (ER) among the spectrum RR comb. The obtained sensing comb, based on a V-shape spectrum envelop, is engineered by controlling a(λ) and k(λ) with opposite monotonicities. Both a(λ)and k(λ) are tuned to have a large dispersion along the wavelength, which means that |a(λ)-k(λ)| keeps rapidly increasing as λres is far away from λc, eliminating the resonance ER quickly down to 0. Experimentally, slot waveguide ring resonators with a radius of 50µm have been fabricated on a standard silicon platform with a Si thickness of 220nm, loaded by racetrack couplers with a straight coupling length of 20µm. Sensing experiments have been carried out by changing the top cladding material from a series of Cargille optical liquids with refraction index values ranging from 1.3 to 1.5. The Q factors of critical coupling resonances was monitored from 2,000 to 6,000, and measured wavelength shifts of this peak are from 1.41µm to 1.56µm. The maximum sensitivity of 1300nm/RIU is observed in the cladding index range 1.30-1.35. To conclude, a new sensing regime by tracking the critical coupling resonance λc of slot waveguide ring resonators is demonstrated. The reported sensitivity is up 1300nm/RIU around the water RI of 1.33, and the monitored sensing FOM is about 2300, which is very close to the FOM values achieved from nanobeam cavities. This work can thus contribute to future integrated optical sensing schemes based on slot RRs.
Tunable Fano resonance in MDM stub waveguide coupled with a U-shaped cavity
Yi, Xingchun; Tian, Jinping; Yang, Rongcao
2018-04-01
A new compact metal-dielectric-metal waveguide system consisting of a stub coupled with a U-cavity is proposed to produce sharp and asymmetric Fano resonance. The transmission properties of the proposed structure are numerically studied by the finite element method and verified by the coupled mode theory. Simulation results reveal that the spectral profile can be easily tuned by adjusting the geometric parameters of the structure. One of the potential application of the proposed structure as a highly efficient plasmonic refractive index nanosensor was investigated with its sensitivity of more than 1000 nm/RIU and a figure of merit of up to 5500. Another application is integrated slow-light device whose group index can be greater than 6. In addition, multiple Fano resonances will occur in the broadband transmission spectrum by adding another U-cavity or (and) stub. The characteristics of the proposed structure are very promising for the highly performance filters, on-chip nanosensors, and slow-light devices.
Design of Compact Wilkinson Power Divider with Harmonic Suppression using T-Shaped Resonators
Siahkamari, Hesam; Yasoubi, Zahra; Jahanbakhshi, Maryam; Mousavi, Seyed Mohammad Hadi; Siahkamari, Payam; Nouri, Mohammad Ehsan; Azami, Sajad; Azadi, Rasoul
2018-04-01
A novel scheme of a shrunken Wilkinson power divider with harmonic suppression, using two identical resonators in the conventional Wilkinson power divider is designed. Moreover, the LC equivalent circuit and its relevant formulas are provided. To substantiate the functionality and soundness of design, a microstrip implementation of this design operating at 1 GHz with the second to eighth harmonic suppression, is developed. The proposed circuit is relatively smaller than the conventional circuit, (roughly 55% of the conventional circuit). Simulation and measurement results for the proposed scheme, which are highly consistent with one another, indicate a good insertion loss about 3.1 dB, input return loss of 20 dB and isolation of 20 dB, while sustaining high-power handling capability over the Wilkinson power divider.
International Nuclear Information System (INIS)
Froehner, F.H.
1977-11-01
A least-squares shape analysis program is described which is used at the Karlsruhe Nuclear Research Center for the extraction of resonance parameters from high-resolution capture data. The FORTRAN program was written for light to medium-weight or near-magic target nuclei whose cross sections are characterized on one hand by broad s-wave levels with negligible Doppler broadening but pronounced multi-level interference, on the other hand by narrow p-, d- ... wave resonances with negligible multi-level interference but pronounced Doppler broadening. Accordingly the Reich-Moore multi-level formalism without Doppler broadening is used for s-wave levels, and a single-level description with Doppler braodening for p-, d- ... wave levels. Calculated capture yields are resolution broadened. Multiple-collision events are simulated by Monte Carlo techniques. Up to five different time-of-flight capture data sets can be fitted simultaneously for samples containing up to ten isotopes. Input and output examples are given and a FORTRAN list is appended. (orig.)
Beyer, Maximilian; Merkt, Frederic
2017-06-01
The recent observations [1,2] of shape and Feshbach resonances in the high-resolution photoelectron spectra of H_2, HD and D_2 in the vicinity of the dissociation thresholds of H_2^+, HD^+ and D_2^+ raise questions concerning their potential role in the formation of H_2^+ and its isotopomers in the early universe by radiative association, a topic of astrophysical interest [3]. Close-coupling calculations for the cross sections of the reactions {H}^+ + {H} &\\to {H}_2^+ + hν {H}^+ + {D} &\\to {HD}^+ + hν {D}^+ + {H} &\\to {HD}^+ + hν {D}^+ + {D} &\\to {D}_2^+ + hν, will be presented which take into account nonadiabatic couplings involving rovibronic and hyperfine interactions, as well as relativistic and radiative corrections. The calculated energies and widths will be compared with the experimental results of Ref. [1,2] for H_2^+ and new data for HD^+ and D_2^+. The effect of the resonances on the radiative association rate coefficients will be discussed, also in comparison with earlier studies [4]. [1] M. Beyer and F. Merkt, Phys. Rev. Lett. 116, 093001 (2016). [2] M. Beyer and F. Merkt, J. Mol. Spectrosc. 330, 147 (2016). [3] Molecule formation in dust-poor environments, J. F. Babb and K. P. Kirby, in "The molecular astrophysics of stars and galaxies", T. W. Hartquist and D. A. Williams, eds., Oxford University Press, Oxford, 1998, pp. 11-34. [4] D. E. Ramaker and J. M. Peek, Phys. Rev. A 13, 58 (1976).
SOLAR ROTATION EFFECTS ON THE HELIOSHEATH FLOW NEAR SOLAR MINIMA
International Nuclear Information System (INIS)
Borovikov, Sergey N.; Pogorelov, Nikolai V.; Ebert, Robert W.
2012-01-01
The interaction between fast and slow solar wind (SW) due to the Sun's rotation creates corotating interaction regions (CIRs), which further interact with each other creating complex plasma structures at large heliospheric distances. We investigate the global influence of CIRs on the SW flow in the inner heliosheath between the heliospheric termination shock (TS) and the heliopause. The stream interaction model takes into account the major global effects due to slow-fast stream interaction near solar minima. The fast and slow wind parameters are derived from the Ulysses observations. We investigate the penetration of corotating structures through the TS and their further propagation through the heliosheath. It is shown that the heliosheath flow structure may experience substantial modifications, including local decreases in the radial velocity component observed by Voyager 1.
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....
Directory of Open Access Journals (Sweden)
Gregor Jost
2017-04-01
Full Text Available Objective: To compare injector-based contrast agent (CA administration with hand injection in magnetic resonance angiography (MRA. Methods: Gadobutrol was administered in 6 minipigs with 3 protocols: (a hand injection (one senior technician, (b hand injection (6 less-experienced technicians, and (c power injector administration. The arterial bolus shape was quantified by test bolus measurements. A head and neck MRA was performed for quantitative and qualitative comparison of signal enhancement. Results: A significantly shorter time to peak was observed for protocol C, whereas no significant differences between protocols were found for peak height and bolus width. However, for protocol C, these parameters showed a much lower variation. The MRA revealed a significantly higher signal-to-noise ratio for injector-based administration. A superimposed strong contrast of the jugular vein was found in 50% of the hand injections. Conclusions: Injector-based CA administration results in a more standardized bolus shape, a higher vascular contrast, and a more robust visualization of target vessels.
Tan, Zhixin; Hao, Xin; Shao, Yonghong; Chen, Yuzhi; Li, Xuejin; Fan, Ping
2014-06-16
We numerically investigate a D-shaped fiber surface plasmon resonance sensor based on all-solid photonic crystal fiber (PCF) with finite element method. In the side-polished PCF sensor, field leakage is guided to penetrate through the gap between the rods, causing a pronounced phase modulation in the deep polishing case. Taking advantage of these amplified phase shifts, a high-performance fiber sensor design is proposed. The significant enhancements arising from this new sensor design should lift the performance of the fiber SPR sensor into the range capable of detecting a wide range of biochemical interactions, which makes it especially attractive for many in vivo and in situ bioanalysis applications. Several parameters which influence the field leakage, such as the polishing position, the pitch of the PCF, and the rod diameter, are inspected to evaluate their impacts. Furthermore, we develop a mathematical model to describe the effects of varying the structural parameters of a D-shaped PCF sensor on the evanescent field and the sensor performance.
Kang, S. K.; Seo, Y. S.; Lee, H. Wk; Aman-ur-Rehman; Kim, G. C.; Lee, J. K.
2011-11-01
A new type of microwave-excited atmospheric pressure plasma source, based on the principle of parallel plate transmission line resonator, is developed for the treatment of large areas in biomedical applications such as skin treatment and wound healing. A stable plasma of 20 mm width is sustained by a small microwave power source operated at a frequency of 700 MHz and a gas flow rate of 0.9 slm. Plasma impedance and plasma density of this plasma source are estimated by fitting the calculated reflection coefficient to the measured one. The estimated plasma impedance shows a decreasing trend while estimated plasma density shows an increasing trend with the increase in the input power. Plasma uniformity is confirmed by temperature and optical emission distribution measurements. Plasma temperature is sustained at less than 40 °C and abundant amounts of reactive species, which are important agents for bacteria inactivation, are detected over the entire plasma region. Large area treatment ability of this newly developed device is verified through bacteria inactivation experiment using E. coli. Sterilization experiment shows a large bacterial killing mark of 25 mm for a plasma treatment time of 10 s.
Heave and Flow: Understanding the role of resonance and shape evolution for heaving flexible panels
Hoover, Alexander; Cortez, Ricardo; Tytell, Eric; Fauci, Lisa
2017-11-01
Many animals that swim or fly use their body to accelerate the fluid around them, transferring momentum from their bodies to the surrounding fluid. The emergent kinematics from this transfer are a result of the coupling between the fluid and the material properties of the body. Here we present a computational study of a 3-dimensional flexible panel that is heaved at its leading edge in an incompressible, viscous fluid. These high-fidelity numerical simulations enable us to examine the role of resonance, fluid forces, and panel deformations have on swimming performance. Varying both the passive material properties and the heaving frequency of the panel, we find peaks in trailing edge amplitude and forward swimming speed are determined by a dimensionless quantity, the effective flexibility. Modal decompositions of panel deflections reveal that the strength of each mode is related to the effective flexibility and peaks in the swimming speed and trailing edge amplitude correspond to peaks in the contributions of different modes. Panels of different material properties but with similar effective flexibilities have modal contributions that evolve similarly over the phase of the heaving cycle and agreement in dominant vortex structures generated by the panel. NSF RTG 1043626.
Shape resonances of Be- and Mg- investigated with the method of analytic continuation
Čurík, Roman; Paidarová, I.; Horáček, J.
2018-05-01
The regularized method of analytic continuation is used to study the low-energy negative-ion states of beryllium (configuration 2 s2ɛ p 2P ) and magnesium (configuration 3 s2ɛ p 2P ) atoms. The method applies an additional perturbation potential and requires only routine bound-state multi-electron quantum calculations. Such computations are accessible by most of the free or commercial quantum chemistry software available for atoms and molecules. The perturbation potential is implemented as a spherical Gaussian function with a fixed width. Stability of the analytic continuation technique with respect to the width and with respect to the input range of electron affinities is studied in detail. The computed resonance parameters Er=0.282 eV, Γ =0.316 eV for the 2 p state of Be- and Er=0.188 eV, Γ =0.167 for the 3 p state of Mg- agree well with the best results obtained by much more elaborate and computationally demanding present-day methods.
International Nuclear Information System (INIS)
Heinze, J.; Kowalczyk, P.; Engelke, F.
1988-01-01
Quasibound levels and shape resonances in the (B 1 Pi/sub u/ -X 1 Σ + /sub g/) band system of 39 K 2 have been recorded by crossed laser-molecular beam techniques. Using optical--optical double resonance, individual rovibrational levels (v'' = 15--18, J'' = 3--25) of the K 2 state are prepared by Franck--Condon pumping (FCP) in a supersonic nozzle beam. Excitation into quasibound levels below and above the (B 1 Pi/sub u/) state barrier is detected as molecular and atomic (K4 2 P 3 /sub // 2 →4 2 S 1 /sub // 2 only) fluorescence. The resonance transition frequencies and shapes are measured and the results are used (a) to determine the scattering resonance energies, widths, and lifetimes; (b) to compare them with values obtained by a ''maximum internal amplitude'' approach [R. J. LeRoy and R. B. Bernstein, J. Chem. Phys. 54, 5114 (1971)]; and (c) to check the agreement with exact calculations of the B state potential using the ''inverted perturbation approach (IPA).'' The bound and quasibound part of the B 1 Pi/sub u/ state including the locus (R = 8.08 +- 0.05 A) of the barrier maximum (298 +- 8 cm -1 above the adiabatic dissociation limit) is found in excellent agreement with previous results. The shape resonances are not highly sensitive to the long-range interatomic forces, here the repulsive dipole--dipole resonance interaction
Gutha, Rithvik R.; Sharp, Christina; Wing, Waylin J.; Sadeghi, Seyed M.
2018-02-01
Chemical sensing based on Localized Surface Plasmonic Resonances (LSPR) and the ultra-sharp optical features of surface lattice resonances (SLR) of arrays of metallic nanoantennas have attracted much attention. Recently we studied biosensing based on the transition between LSPR and SLR (hybridization phase), demonstrating significantly higher refractive index sensitivity than each of these resonances individually. In this contribution we study the impact of size and shape of the metallic nanoantennas on the hybridization process and the way they influence application of this process for biosensing, wherein miniscule variation of the refractive index of the environment leads to dramatic changes in the spectral properties of the arrays.
Yakshina, E. A.
2016-10-21
The observation of the Stark-tuned Förster resonances between Rydberg atoms excited by narrowband cw laser radiation requires usage of a Stark-switching technique in order to excite the atoms first in a fixed electric field and then to induce the interactions in a varied electric field, which is scanned across the Förster resonance. In our experiments with a few cold Rb Rydberg atoms, we have found that the transients at the edges of the electric pulses strongly affect the line shapes of the Förster resonances, since the population transfer at the resonances occurs on a time scale of ∼100 ns, which is comparable with the duration of the transients. For example, a short-term ringing at a certain frequency causes additional radio-frequency-assisted Förster resonances, while nonsharp edges lead to asymmetry. The intentional application of the radio-frequency field induces transitions between collective states, whose line shape depends on the interaction strengths and time. Spatial averaging over the atom positions in a single interaction volume yields a cusped line shape of the Förster resonance. We present a detailed experimental and theoretical analysis of the line shape and time dynamics of the Stark-tuned Förster resonances Rb(nP3/2)+Rb(nP3/2)→Rb(nS1/2)+Rb([n+1]S1/2) for two Rb Rydberg atoms interacting in a time-varying electric field.
Yakshina, E. A.; Tretyakov, D. B.; Beterov, I. I.; Entin, V. M.; Andreeva, C.; Cinins, A.; Markovski, A.; Iftikhar, Z.; Ekers, Aigars; Ryabtsev, I. I.
2016-01-01
The observation of the Stark-tuned Förster resonances between Rydberg atoms excited by narrowband cw laser radiation requires usage of a Stark-switching technique in order to excite the atoms first in a fixed electric field and then to induce the interactions in a varied electric field, which is scanned across the Förster resonance. In our experiments with a few cold Rb Rydberg atoms, we have found that the transients at the edges of the electric pulses strongly affect the line shapes of the Förster resonances, since the population transfer at the resonances occurs on a time scale of ∼100 ns, which is comparable with the duration of the transients. For example, a short-term ringing at a certain frequency causes additional radio-frequency-assisted Förster resonances, while nonsharp edges lead to asymmetry. The intentional application of the radio-frequency field induces transitions between collective states, whose line shape depends on the interaction strengths and time. Spatial averaging over the atom positions in a single interaction volume yields a cusped line shape of the Förster resonance. We present a detailed experimental and theoretical analysis of the line shape and time dynamics of the Stark-tuned Förster resonances Rb(nP3/2)+Rb(nP3/2)→Rb(nS1/2)+Rb([n+1]S1/2) for two Rb Rydberg atoms interacting in a time-varying electric field.
Czech Academy of Sciences Publication Activity Database
Landa, Michal; Sedlák, Petr; Šittner, Petr; Seiner, Hanuš; Heller, Luděk
481-482, - (2008), s. 567-573 ISSN 0921-5093 R&D Projects: GA ČR GA101/06/0768 Institutional research plan: CEZ:AV0Z20760514; CEZ:AV0Z10100520 Keywords : modal resonant ultrasound spectroscopy * elastic properties * shape memory alloy s Subject RIV: BI - Acoustics Impact factor: 1.806, year: 2008
The '0.4 eV' shape resonance of electron scattering from mercury in a Franck-Hertz tube
International Nuclear Information System (INIS)
Nicoletopoulos, Peter
2004-01-01
The alternative version of the Franck-Hertz experiment with mercury, in which a two-grid tube is used as a combination of electron gun, equipotential collision space and detection cell, was analysed recently in considerable detail. In particular, it was inferred that, at optimal pressure, the formation of peaks in the anode current at inelastic thresholds is mediated inside the detection cell by the large variation, a maximum at 0.4 eV, in the cross section for elastic scattering. This variation is due to a shape resonance in the electron-mercury system and is observable persuasively at the onset of anode current as a sharp peak followed by a clear minimum. In this paper, the passage of electrons through the second grid to the anode region is analysed in terms of kinetic theory. The discussion is based on a simplified expression for the electron current derivable from an approximate form of the Boltzmann transport equation that maintains the spatial density gradient but omits elastic energy losses. The estimated range of pressure underlying this kind of idealization is in good agreement with experiment. An explicit solution is obtained by constructing an analytic expression for the momentum transfer cross section of mercury using a recent theory of generalized Fano profiles for overlapping resonances. This solution is used in order to model successfully the formation of peaks at the threshold of anode current and at excitation potentials, and to explain the dependence of the observed profiles on the pressure and on the sign and magnitude of the potential across the detection cell
Observations of linear polarization in deep minima of WW Vul
International Nuclear Information System (INIS)
Grinin, V.P.; Kiselev, N.N.; Minikulov, N.Kh.; Chernova, G.P.; AN Tadzhikskoj SSR, Dushanbe. Inst. Astrofiziki)
1988-01-01
In the course of patrol photometric and polarimetric observations of WW Vul, initiated in 1986 in the Crimea and Sanglok, a broad photometrical minimum was registered, the deepest part of which being composed of three consecutive weakenings of brightness. The increase of linear polarization up to 5-6% (in V band) was observed in each of them. The analysis of the observational data shows, that the main part of polarized light occurs due to scattering of star radiation by dust particles of the circumstellar envelope. the contribution of this polarized radiation increases when the occultation of the star by the opaque dust cloud weakenes the direct (non-polarized) radiation of the star. Additional source of light polarization is the alignement of non-spherical particles in the dust cloud, which are responsible for occultation. Some arguments are given in favor to the idea, that the asymmetry axis of the circumstellar disc - like envelope of WW Vul is oriented parallel to the local interstellar magnetic field. If and alignment of non-spherical particles is caused by magnetic field of the disc, magnetic lines should follow the plane of the disc. The observations confirm the hypothesis, that the source of blue emission, observed in deep minima of such type stars, is the scattered radiation of circumstellar dust
INTERPLANETARY MAGNETIC FLUX DEPLETION DURING PROTRACTED SOLAR MINIMA
International Nuclear Information System (INIS)
Connick, David E.; Smith, Charles W.; Schwadron, Nathan A.
2011-01-01
We examine near-Earth solar wind observations as assembled within the Omni data set over the past 15 years that constitute the latest solar cycle. We show that the interplanetary magnetic field continues to be depleted at low latitudes throughout the protracted solar minimum reaching levels below previously predicted minima. We obtain a rate of flux removal resulting in magnetic field reduction by 0.5 nT yr -1 at 1 AU when averaged over the years 2005-2009 that reduces to 0.3 nT yr -1 for 2007-2009. We show that the flux removal operates on field lines that follow the nominal Parker spiral orientation predicted for open field lines and are largely unassociated with recent ejecta. We argue that the field line reduction can only be accomplished by ongoing reconnection of nominally open field lines or very old closed field lines and we contend that these two interpretations are observationally equivalent and indistinguishable.
Shape resonances and EXAFS scattering in the $Pt L_{2,3}$ XANES from a Pt electrode
O'Grady, W E
1999-01-01
Atomic hydrogen and oxygen adsorption on a platinum electrode in H /sub 2/SO/sub 4/ and HClO/sub 4/ electrolytes were studied by Pt L /sub 23/ XANES. The Pt electrode was formed of highly dispersed 1.5-3.0 nm particles supported on $9 carbon. A difference procedure utilizing the L/sub 2/ and L/sub 3/ spectra at various applied voltages was used to isolate the electronic and geometric effects in the XANES spectra. At 0.54 V (relative to RHE) the Pt electrode in $9 HClO/sub 4/ is assumed to be "clean". By taking the difference between the spectra at 0.0 and 0.54 V, the Pt-H antibonding state (electronic effect) is isolated and found to have a Fano-resonance line shape. In addition, a $9 significant Pt-H EXAFS scattering (geometric effect) was found for photon energies 0 to 20 eV above the edge. The difference between the spectra at 1.14 and 0.54 V allows isolation of the Pt-O antibonding state and the Pt-O EXAFS $9 scattering. (7 refs).
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...
Vampola, Tomáš; Horáček, Jaromír; Laukkanen, Anne-Maria; Švec, Jan G
2015-04-01
Resonance frequencies of the vocal tract have traditionally been modelled using one-dimensional models. These cannot accurately represent the events in the frequency region of the formant cluster around 2.5-4.5 kHz, however. Here, the vocal tract resonance frequencies and their mode shapes are studied using a three-dimensional finite element model obtained from computed tomography measurements of a subject phonating on vowel [a:]. Instead of the traditional five, up to eight resonance frequencies of the vocal tract were found below the prominent antiresonance around 4.7 kHz. The three extra resonances were found to correspond to modes which were axially asymmetric and involved the piriform sinuses, valleculae, and transverse vibrations in the oral cavity. The results therefore suggest that the phenomenon of speaker's and singer's formant clustering may be more complex than originally thought.
Nazari, Tavakol; Khazaeinezhad, Reza; Jung, Woohyun; Joo, Boram; Kong, Byung-Joo; Oh, Kyunghwan
2015-07-13
Dual resonant bands in UV and the visible range were simultaneously observed in the enhanced optical transmission (EOT) through star-shaped plasmonic structures. EOTs through four types of polygonal bull's eyes with a star aperture surrounded by the concentric star grooves were analyzed and compared for 3, 4, 5, and 6 corners, using finite difference time domain (FDTD) method. In contrast to plasmonic resonances in the visible range, the UV-band resonance intensity was found to scale with the number of corners, which is related with higher order multipole interactions. Spectral positions and relative intensities of the dual resonances were analyzed parametrically to find optimal conditions to maximize EOT in UV-visible dual bands.
Multiple local minima in IMRT optimization based on dose-volume criteria
International Nuclear Information System (INIS)
Wu Qiuwen; Mohan, Radhe
2002-01-01
Multiple local minima traps are known to exist in dose-volume and dose-response objective functions. Nevertheless, their presence and consequences are not considered impediments in finding satisfactory solutions in routine optimization of IMRT plans using gradient methods. However, there is often a concern that a significantly superior solution may exist unbeknownst to the planner and that the optimization process may not be able to reach it. We have investigated the soundness of the assumption that the presence of multiple minima traps can be ignored. To find local minima, we start the optimization process a large number of times with random initial intensities. We investigated whether the occurrence of local minima depends upon the choice of the objective function parameters and the number of variables and whether their existence is an impediment in finding a satisfactory solution. To learn about the behavior of multiple minima, we first used a symmetric cubic phantom containing a cubic target and an organ-at-risk surrounding it to optimize the beam weights of two pairs of parallel-opposed beams using a gradient technique. The phantom studies also served to test our software. Objective function parameters were chosen to ensure that multiple minima would exist. Data for 500 plans, optimized with random initial beam weights, were analyzed. The search process did succeed in finding the local minima and showed that the number of minima depends on the parameters of the objective functions. It was also found that the consequences of local minima depended on the number of beams. We further searched for the multiple minima in intensity-modulated treatment plans for a head-and-neck case and a lung case. In addition to the treatment plan scores and the dose-volume histograms, we examined the dose distributions and intensity patterns. We did not find any evidence that multiple local minima affect the outcome of optimization using gradient techniques in any clinically
Lee, Mi Gyoung; Moon, Cheon Woo; Park, Hoonkee; Sohn, Woonbae; Kang, Sung Bum; Lee, Sanghan; Choi, Kyoung Jin; Jang, Ho Won
2017-10-01
The performance of plasmonic Au nanostructure/metal oxide heterointerface shows great promise in enhancing photoactivity, due to its ability to confine light to the small volume inside the semiconductor and modify the interfacial electronic band structure. While the shape control of Au nanoparticles (NPs) is crucial for moderate bandgap semiconductors, because plasmonic resonance by interband excitations overlaps above the absorption edge of semiconductors, its critical role in water splitting is still not fully understood. Here, first, the plasmonic effects of shape-controlled Au NPs on bismuth vanadate (BiVO 4 ) are studied, and a largely enhanced photoactivity of BiVO 4 is reported by introducing the octahedral Au NPs. The octahedral Au NP/BiVO 4 achieves 2.4 mA cm -2 at the 1.23 V versus reversible hydrogen electrode, which is the threefold enhancement compared to BiVO 4 . It is the highest value among the previously reported plasmonic Au NPs/BiVO 4 . Improved photoactivity is attributed to the localized surface plasmon resonance; direct electron transfer (DET), plasmonic resonant energy transfer (PRET). The PRET can be stressed over DET when considering the moderate bandgap semiconductor. Enhanced water oxidation induced by the shape-controlled Au NPs is applicable to moderate semiconductors, and shows a systematic study to explore new efficient plasmonic solar water splitting cells. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
International Nuclear Information System (INIS)
Schaden, M.; Zhao, K. F.; Wu, Z.
2007-01-01
In an evanescent wave magnetometer the Zeeman polarization is probed at micrometer to submicrometer distances from the cell surface. The electron paramagnetic resonance lines of an evanescent wave magnetometer in the presence of a magnetic field gradient exhibit edge enhancement seen previously in nuclear magnetic resonance lines. We present a theoretical model that describes quantitatively the shape of the magnetic resonance lines of an evanescent wave magnetometer under a wide range of experimental conditions. It accounts for diffusion broadening in the presence of a magnetic field gradient as well as interactions of spin polarized Rb atoms with the coated Pyrex glass surfaces. Depending on the field gradient, cell thickness, and buffer gas pressure, the resonance line may have the form of a single asymmetric peak or two peaks localized near the front and back surfaces in frequency space. The double-peaked response depends on average characteristics of the surface interactions. Its shape is sensitive to the dwell time, relaxation probability, and average phase shift of adsorbed spin polarized Rb atoms
Directory of Open Access Journals (Sweden)
Hamidreza Barikani
2014-01-01
Full Text Available Background: The aim of this in vitro study was to evaluate the effect of shape, diameter and length of implants on their primary stability based on resonance frequency analysis. Materials and Methods: Replace select tapered and Branemark MK III implants were selected. Each of these two selected groups was divided into nine subgroups based on the implant length (IL (short, medium and long and the implant diameter (ID (narrow platform [NP], regular platform [RP] and wide platform [WP]. Five implants were assigned to each of the nine subgroups. Implants were placed in artificial bone blocks with bone quality similar to D3 bone. Immediately after the implant placement, its primary stability was measured using Osstell Mentor equipment. T-test and Tukey′s honest significant difference Post hoc were performed for data analysis. Statistical significance was defined at P < 0.05. Results: Replace select system showed significantly higher primary stability compared to the Branemark system, when using the short implants for all three diameters (P ≤ 0.004. However, in medium length implants there were no significant differences between the two implant systems (P ≥ 0.31. In long implants, only when the NP and RP implants were used, the Replace Select system showed significantly higher primary stability compared to the Branemark system (P = 0.000. In the replace select system, long implants had a significantly higher primary stability compared to medium and short length implants (P ≤ 0.003. In the NP and RP Branemark implants, short implants showed significantly lower primary stability compared to medium and long implants (P ≤ 0.002. However, in WP Branemark implants, primary stability increased significantly with increasing the IL from short to medium and from medium to long (P = 0.000. There were also significant differences between NP and the two other wider implants in both systems (P = 0.000. Conclusion: The use of tapered implants is
Recovery from Maunder-like Grand Minima in a Babcock–Leighton Solar Dynamo Model
Karak, Bidya Binay; Miesch, Mark
2018-06-01
The Sun occasionally goes through Maunder-like extended grand minima when its magnetic activity drops considerably from the normal activity level for several decades. Many possible theories have been proposed to explain the origin of these minima. However, how the Sun managed to recover from such inactive phases every time is even more enigmatic. The Babcock–Leighton type dynamos, which are successful in explaining many features of the solar cycle remarkably well, are not expected to operate during grand minima due to the lack of a sufficient number of sunspots. In this Letter, we explore the question of how the Sun could recover from grand minima through the Babcock–Leighton dynamo. In our three-dimensional dynamo model, grand minima are produced spontaneously as a result of random variations in the tilt angle of emerging active regions. We find that the Babcock–Leighton process can still operate during grand minima with only a minimal number of sunspots, and that the model can emerge from such phases without the need for an additional generation mechanism for the poloidal field. The essential ingredient in our model is a downward magnetic pumping, which inhibits the diffusion of the magnetic flux across the solar surface.
International Nuclear Information System (INIS)
Techapiesancharoenkij, Ratchatee; Kostamo, Jari; Allen, Samuel M.; O'Handley, Robert C.
2011-01-01
The prospect of using ferromagnetic shape memory alloys (FSMAs) is promising for a resonant actuator that requires large strain output and a drive frequency below 1 kHz. In this investigation, three FSMA actuators, equipped with tetragonal off-stoichiometric Ni 2 MnGa single crystals, were developed to study their frequency response and resonant characteristics. The first actuator, labeled as A1, was constructed with low-k bias springs and one Ni-Mn-Ga single crystal. The second actuator, labeled as A2, was constructed with high-k bias springs and one Ni-Mn-Ga crystal. The third actuator, labeled as A3, was constructed with high-k bias springs and two Ni-Mn-Ga crystals connected in parallel. The three actuators were magnetically driven over the frequency range of 10 Hz-1 kHz under 2 and 3.5 kOe magnetic-field amplitudes. The field amplitude of 2 kOe is insufficient to generate significant strain output from all three actuators; the maximum magnetic-field-induced strain (MFIS) at resonance is 2%. The resonant MFIS output improves to 5% under 3.5-kOe amplitude. The frequency responses of all three actuators show a strong effect of the spring k constant and the Ni-Mn-Ga modulus stiffness on the resonant frequencies. The resonant frequency of the Ni-Mn-Ga actuator was raised from 450 to 650 Hz by increasing bias spring k constant and/or the number of Ni-Mn-Ga crystals. The higher number of the Ni-Mn-Ga crystals not only increases the magnetic force output but also raises the total stiffness of the actuator resulting in a higher resonant frequency. The effective modulus of the Ni-Mn-Ga is calculated from the measured resonant frequencies using the mass-spring equation; the calculated modulus values for the three actuators fall in the range of 50-60 MPa. The calculated effective modulus appears to be close to the average modulus value between the low twinning modulus and high elastic modulus of the untwined Ni-Mn-Ga crystal. - Highlights: → Dynamic FSMA actuation shows
International Nuclear Information System (INIS)
Even, J; Loualiche, S
2003-01-01
The problem of the energy levels and electronic wavefunctions in quantum dots is studied in the parabolic coordinates system. A conventional effective mass Hamiltonian is written. For an infinite potential barrier, it is related to the more general problem of finding the resonance modes in a cavity. The problem is found to be separable for a biconvex-shaped cavity or quantum dot with an infinite potential barrier. This first shape of quantum dot corresponds to the intersection of two orthogonal confocal parabolas. Then plano-convex lens-shaped cavities or quantum dots are studied. This problem is no more separable in the parabolic coordinates but using symmetry properties, we show that the exact solutions of the problem are simple combinations of the previous solutions. The same approach is used for spherical coordinates and hemispherical quantum dots. It is finally shown that convex lens-shaped quantum dots give a good description of self-organized InAs quantum dots grown on InP
Mori, Koichi; Hagino, Hirofumi; Saitou, Osamu; Yotsutsuji, Takashi; Tonami, Syuichi; Nakamura, Mamoru; Kuranishi, Makoto
2002-01-01
Recently, an increasing number of volumetric studies of the human brain have been reported, using three-dimensional magnetic resonance imaging (3D-MRI). To our knowledge, however, there are few investigations on the relation of the volume and shape of voxels which constitute an MR image to the accuracy in volume measurement of an imaged object. The purpose of this study was to evaluate the effect of a different shape of voxel, that is, isotropic or anisotropic, as well as the volume of a voxel on the volume measurement based on the original image data and multiplanar reconstruction (MPR) data, respectively. In the experiment, we repeatedly acquired contiguous sagittal images of a single globe phantom with a known volume under the condition in which the volume and shape of voxels varied, on a 1.5T MR scanner. We used a gradient echo sequence (3D FLASH). The volume of the globe phantom from both original images and MPR ones was measured on workstations employing a semi-automated local thresholding technique. As a result, the smaller volume of voxels tended to give us the more correct measurement, and an isotropic voxel reduced measurement errors as compared to an anisotropic one. Therefore, it is concluded that the setting of voxel with both an isotropic shape and small volume, e.g., a voxel of 1 mm x 1 mm x 1 mm at present, is recommended in order to get a precise volume measurement using 3D-MRI.
International Nuclear Information System (INIS)
Mori, Koichi; Tonami, Syuichi; Nakamura, Mamoru; Kuranishi, Makoto; Hagino, Hirofumi; Saitou, Osamu; Yotsutsuji, Takashi
2002-01-01
Recently, an increasing number of volumetric studies of the human brain have been reported, using three-dimensional magnetic resonance imaging (3D-MRI). To our knowledge, however, there are few investigations on the relation of the volume and shape of voxels which constitute and MR image to the accuracy in volume measurement of an imaged object. The purpose of this study was to evaluate the effect of a different shape of voxel, that is, isotropic or anisotropic, as well as the volume of a voxel on the volume measurement based on the original image data and multiplanar reconstruction (MPR) data, respectively. In the experiment, we repeatedly acquired contiguous sagittal images of a single globe phantom with a known volume under the condition in which the volume and shape of voxels varied, on a 1.5 T MR scanner. We used a gradient echo sequence (3D FLASH). The volume of the globe phantom from both original images and MPR ones was measured on workstations employing a semi-automated local thresholding technique. As a result, the smaller volume of voxels tended to give us the more correct measurement, and an isotropic voxel reduced measurement errors as compared to an anisotropic one. Therefore, it is concluded that the setting of voxel with both an isotropic shape and small volume, e.g., a voxel of 1 mm x 1 mm x 1 mm at present, is recommended in order to get a precise volume measurement using 3D-MRI. (author)
Erica multiflora (Ericaceae), Onosma pygmaeum (Boraginaceae) and Typha minima (Typhaceae) in Albania
DEFF Research Database (Denmark)
Mullaj, Alfred; Tan, Kit
2010-01-01
Erica multiflora (Ericaceae) in Albania is confirmed to occur in the Karaburun Peninsula as well as other regions in Albania. This links the distribution of the species in Croatia to that of western Greece. Onosma pygmaeum (Boraginaceae) and Typha minima (Typhaceae) are reported as new for the Al......Erica multiflora (Ericaceae) in Albania is confirmed to occur in the Karaburun Peninsula as well as other regions in Albania. This links the distribution of the species in Croatia to that of western Greece. Onosma pygmaeum (Boraginaceae) and Typha minima (Typhaceae) are reported as new...
Energy Technology Data Exchange (ETDEWEB)
Giangregorio, Maria M. [Institute of Inorganic Methodologies and of Plasmas, CNR-IMIP; Dastmalchi, Babak [Ames Laboratory; Suvorova, Alexandra [University of Western Australia; Bianco, Giuseppe V. [Institute of Inorganic Methodologies and of Plasmas, CNR-IMIP; Hingerl, Kurt [Johannes Kepler University Linz; Bruno, Giovanni [Institute of Inorganic Methodologies and of Plasmas, CNR-IMIP; Losurdo, Maria [Institute of Inorganic Methodologies and of Plasmas, CNR-IMIP
2014-01-01
For device integration purposes plasmonic metal nanoparticles must be supported/deposited on substrates. Therefore, it is important to understand the interaction between surfactant-free plasmonic metal nanoparticles and different substrates, as well as to identify factors that drive nanoparticles nucleation and formation. Here we show that for nanoparticles grown directly on supports, the substrate/nanoparticle interfacial energy affects the equilibrium shape of nanoparticles. Therefore, oblate, spherical and prolate Au nanoparticles (NPs) with different shapes have been deposited by radiofrequency sputtering on substrates with different characteristics, namely a dielectric oxide Al2O3 (0001), a narrow bandgap semiconductor Si (100), and a polar piezoelectric wide bandgap semiconductor 4H–SiC (0001). We demonstrate that the higher the substrate surface energy, the higher the interaction with the substrate, resulting in flat prolate Au nanoparticles. The resulting localized surface plasmon resonance characteristics of Au NPs/Al2O3, Au NPs/Si and Au NPs/SiC have been determined by spectroscopic ellipsometry and correlated with their structure and shape studied by transmission electron microscopy. Finally, we have demonstrated the diverse response of the tailored plasmonic substrates as ultrasensitive SERS chemical sensors. Flat oblates Au NPs on SiC result in an enhanced and more stable SERS response. The experimental findings are validated by numerical simulations of electromagnetic fields.
On the minima of the time integrated perturbation factor in the Scherer-Blume theory
International Nuclear Information System (INIS)
Silveira, E.F. da; Freire Junior, F.L.; Massolo, C.P.; Schaposnik, F.A.
1981-09-01
The minima in the correlation time dependence of the Scherer-Blume time integrated attenuation coefficients for the hyperfine perturbation of ions recoiling in gas are studied. Its position and depth are determined for different physical situations and comparison with experimental data is shown. (Author) [pt
Oferkin, Igor V; Katkova, Ekaterina V; Sulimov, Alexey V; Kutov, Danil C; Sobolev, Sergey I; Voevodin, Vladimir V; Sulimov, Vladimir B
2015-01-01
The adequate choice of the docking target function impacts the accuracy of the ligand positioning as well as the accuracy of the protein-ligand binding energy calculation. To evaluate a docking target function we compared positions of its minima with the experimentally known pose of the ligand in the protein active site. We evaluated five docking target functions based on either the MMFF94 force field or the PM7 quantum-chemical method with or without implicit solvent models: PCM, COSMO, and SGB. Each function was tested on the same set of 16 protein-ligand complexes. For exhaustive low-energy minima search the novel MPI parallelized docking program FLM and large supercomputer resources were used. Protein-ligand binding energies calculated using low-energy minima were compared with experimental values. It was demonstrated that the docking target function on the base of the MMFF94 force field in vacuo can be used for discovery of native or near native ligand positions by finding the low-energy local minima spectrum of the target function. The importance of solute-solvent interaction for the correct ligand positioning is demonstrated. It is shown that docking accuracy can be improved by replacement of the MMFF94 force field by the new semiempirical quantum-chemical PM7 method.
Directory of Open Access Journals (Sweden)
Igor V. Oferkin
2015-01-01
Full Text Available The adequate choice of the docking target function impacts the accuracy of the ligand positioning as well as the accuracy of the protein-ligand binding energy calculation. To evaluate a docking target function we compared positions of its minima with the experimentally known pose of the ligand in the protein active site. We evaluated five docking target functions based on either the MMFF94 force field or the PM7 quantum-chemical method with or without implicit solvent models: PCM, COSMO, and SGB. Each function was tested on the same set of 16 protein-ligand complexes. For exhaustive low-energy minima search the novel MPI parallelized docking program FLM and large supercomputer resources were used. Protein-ligand binding energies calculated using low-energy minima were compared with experimental values. It was demonstrated that the docking target function on the base of the MMFF94 force field in vacuo can be used for discovery of native or near native ligand positions by finding the low-energy local minima spectrum of the target function. The importance of solute-solvent interaction for the correct ligand positioning is demonstrated. It is shown that docking accuracy can be improved by replacement of the MMFF94 force field by the new semiempirical quantum-chemical PM7 method.
Learning behavior and temporary minima of two-layer neural networks
Annema, Anne J.; Hoen, Klaas; Hoen, Klaas; Wallinga, Hans
1994-01-01
This paper presents a mathematical analysis of the occurrence of temporary minima during training of a single-output, two-layer neural network, with learning according to the back-propagation algorithm. A new vector decomposition method is introduced, which simplifies the mathematical analysis of
Solar Cycle Variability and Grand Minima Induced by Joy's Law Scatter
Karak, Bidya Binay; Miesch, Mark S.
2017-08-01
The strength of the solar cycle varies from one cycle to another in an irregular manner and the extreme example of this irregularity is the Maunder minimum when Sun produced only a few spots for several years. We explore the cause of these variabilities using a 3D Babcock--Leighton dynamo. In this model, based on the toroidal flux at the base of the convection zone, bipolar magnetic regions (BMRs) are produced with flux, tilt angle, and time of emergence all obtain from their observed distributions. The dynamo growth is limited by a tilt quenching.The randomnesses in the BMR emergences make the poloidal field unequal and eventually cause an unequal solar cycle. When observed fluctuations of BMR tilts around Joy's law, i.e., a standard deviation of 15 degrees, are considered, our model produces a variation in the solar cycle comparable to the observed solar cycle variability. Tilt scatter also causes occasional Maunder-like grand minima, although the observed scatter does not reproduce correct statistics of grand minima. However, when we double the tilt scatter, we find grand minima consistent with observations. Importantly, our dynamo model can operate even during grand minima with only a few BMRs, without requiring any additional alpha effect.
The Nature of Grand Minima and Maxima from Fully Nonlinear Flux Transport Dynamos
Energy Technology Data Exchange (ETDEWEB)
Inceoglu, Fadil; Arlt, Rainer [Leibniz-Institute for Astrophysics Potsdam, An der Sternwarte 16, D-14482, Potsdam (Germany); Rempel, Matthias, E-mail: finceoglu@aip.de [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 (United States)
2017-10-20
We aim to investigate the nature and occurrence characteristics of grand solar minimum and maximum periods, which are observed in the solar proxy records such as {sup 10}Be and {sup 14}C, using a fully nonlinear Babcock–Leighton type flux transport dynamo including momentum and entropy equations. The differential rotation and meridional circulation are generated from the effect of turbulent Reynolds stress and are subjected to back-reaction from the magnetic field. To generate grand minimum- and maximum-like periods in our simulations, we used random fluctuations in the angular momentum transport process, namely the Λ-mechanism, and in the Babcock–Leighton mechanism. To characterize the nature and occurrences of the identified grand minima and maxima in our simulations, we used the waiting time distribution analyses, which reflect whether the underlying distribution arises from a random or a memory-bearing process. The results show that, in the majority of the cases, the distributions of grand minima and maxima reveal that the nature of these events originates from memoryless processes. We also found that in our simulations the meridional circulation speed tends to be smaller during grand maximum, while it is faster during grand minimum periods. The radial differential rotation tends to be larger during grand maxima, while it is smaller during grand minima. The latitudinal differential rotation, on the other hand, is found to be larger during grand minima.
Abd El-Gawad, Ahmed M; El-Amier, Yasser A; Bonanomi, Giuliano
2018-01-01
Aromatic plants attract the attention of many researchers worldwide due to their worthy applications in agriculture, human prosperity, and the environment. Essential oil (EO) could be exploited as effective alternatives to synthetic compounds as it has several biological activities including allelopathy. The EO from the aerial parts of Rhynchosia minima was extracted by hydrodistillation and investigated by gas chromatography/mass spectrometry (GC/MS). Different concentrations (50, 100, 150 and 200 μL L -1 ) of the EO were prepared for investigation of their allelopathic potential on two weeds; Dactyloctenium aegyptium and Rumex dentatus. Twenty-eight compounds, mainly sesquiterpenes (69.13%) were determined. The major compounds are α-eudesmol, 2-allyl-5-tert-butylhydroquinone, caryophyllene oxide, trans-caryophyllene, and τ-cadinol. The EO from the R. minima showed a significant inhibition of D. aegyptium and R. dentatus germination, while the seedling growth was stimulated. Therefore, it is not recommended to treat these noxious weeds with the EO of R. minima before the germination. In contrast, the apparent stimulatory effect on the seedling growth offers further studies to use the EO of R. minima to enhance the fitness of different economic crops. However, characterization of green bio-herbicides such as EO (allelochemicals) from wild plants raises a new opportunity for the incorporation of new technology of bio-control against the noxious weeds. © 2018 Wiley-VHCA AG, Zurich, Switzerland.
Patsis, P. A.; Harsoula, M.
2018-05-01
Context. We present and discuss the orbital content of a rather unusual rotating barred galaxy model, in which the three-dimensional (3D) family, bifurcating from x1 at the 2:1 vertical resonance with the known "frown-smile" side-on morphology, is unstable. Aims: Our goal is to study the differences that occur in the phase space structure at the vertical 2:1 resonance region in this case, with respect to the known, well studied, standard case, in which the families with the frown-smile profiles are stable and support an X-shaped morphology. Methods: The potential used in the study originates in a frozen snapshot of an N-body simulation in which a fast bar has evolved. We follow the evolution of the vertical stability of the central family of periodic orbits as a function of the energy (Jacobi constant) and we investigate the phase space content by means of spaces of section. Results: The two bifurcating families at the vertical 2:1 resonance region of the new model change their stability with respect to that of most studied analytic potentials. The structure in the side-on view that is directly supported by the trapping of quasi-periodic orbits around 3D stable periodic orbits has now an infinity symbol (i.e. ∞-type) profile. However, the available sticky orbits can reinforce other types of side-on morphologies as well. Conclusions: In the new model, the dynamical mechanism of trapping quasi-periodic orbits around the 3D stable periodic orbits that build the peanut, supports the ∞-type profile. The same mechanism in the standard case supports the X shape with the frown-smile orbits. Nevertheless, in both cases (i.e. in the new and in the standard model) a combination of 3D quasi-periodic orbits around the stable x1 family with sticky orbits can support a profile reminiscent of the shape of the orbits of the 3D unstable family existing in each model.
Tewari, Vinod Kumar; Tripathi, Ravindra; Aggarwal, Subodh; Hussain, Mazhar; Das Gupta, Hari Kishan
2017-01-01
The existing Intraoperative MRI (IMRI) of developed countries is too costly to be affordable in any developing country and out of the reach of common and poor people of developing country at remote areas. We have used the pre-existing (refurbished) 3 side open "C" shaped 0.2 Tesla MRI for IMRI in a very remote area. In this technique the 0.2 Tesla MRI and the operating theatre were merged. MRI table was used as an operation table. We have operated 36 cases via IMRI from November 2005 to till date. First case operated was on 13 th nov 2005. Low (0.2) Tesla open setup costs very low (around Rs 40 lakhs) so highly affordable to management and thus to patients, used for diagnostic and therapeutic purposes both, the equipments like Nitrous, oxygen and suction is outside the MRI room so no noise inside operative room, positioning the patient didn't take much time due to manual adjustments, no special training to nurses and technicians required because of low (0.2) Tesla power of magnet and same instruments and techniques, sequencing took only 1.31 mints per sequence and re registration is not required since we always note down the two orthogonal axis in x and y axis in preoperative imaging and we were able to operate on posterior fossa tumors as well because of no head fixation except with leucoplast strap. Moreover the images we got intraoperative are highly acceptable. Three side open 0.2 Tesla MRI system, if used for intraoperative guidance, is highly affordable and overcomes the limitations of western setup of IMRI. Postoperative MRI images were highly acceptable and also highly affordable too.
Koshelev, Alexei
2013-03-01
Stacks of intrinsic Josephson-junctions are realized in mesas fabricated out of layered superconducting single crystals, such as Bi2Sr2CaCu2O8 (BSCCO). Synchronization of phase oscillations in different junctions can be facilitated by the coupling to the internal cavity mode leading to powerful and coherent electromagnetic radiation in the terahertz frequency range. An important characteristic of this radiation is the shape of the emission line. A finite line width appears due to different noise sources leading to phase diffusion. We investigated the intrinsic line shape caused by the thermal noise for a mesa fabricated on the top of a BSCCO single crystal. In the ideal case of fully synchronized stack the finite line width is coming from two main contributions, the quasiparticle-current noise inside the mesa and the fluctuating radiation in the base crystal. We compute both contributions and conclude that for realistic mesa's parameters the second mechanism typically dominates. The role of the cavity quality factor in the emission line spectrum is clarified. Analytical results were verified by numerical simulations. In real mesa structures part of the stack may not be synchronized and chaotic dynamics of unsynchronized junctions may determine the real line width. Work supported by UChicago Argonne, LLC, under contract No. DE-AC02-06CH11357.
Yue, Z. K.; Liu, Z. Z.; Hou, Y. J.; Zeng, H.; Liang, L. H.; Cui, S.
2017-11-01
The problem that misalignment between the transmitting coil and the receiving coil significantly impairs the transmission power and efficiency of the system has been attached more and more attention. In order to improve the uniformity of the magnetic field between the two coils to solve this problem, a new type of coil called pan-shaped coil is proposed. Three-dimension simulation models of the planar-core coil and the pan-shaped coil are established using Ansoft Maxwell software. The coupling coefficient between the transmitting coil and the receiving coil is obtained by simulating the magnetic field with the receiving coil misalignment or not. And the maximum percentage difference strength along the radial direction which is defined as the magnetic field uniformity factor is calculated. According to the simulation results of the two kinds of coil structures, it is found that the new type of coil structure can obviously improve the uniformity of the magnetic field, coupling coefficient and power transmission properties between the transmitting coil and the receiving coil.
DEFF Research Database (Denmark)
García-Fernández, Juan Antonio; Jurado-Navas, Antonio; Fernández-Navarro, Mariano
2015-01-01
of avoiding any local minima. In this manner, errors in the positioning algorithm are only due to multipath environment and co-channel interference, ensuring that local minima do not affect the result offered by the positioning method. A provisional patent application based on this method has been filed...
Resonances in photoabsorption: Predissociation line shapes in the 3pπD1Π+u ← Χ1Σg+ system in H2
International Nuclear Information System (INIS)
Mezei, J. Zs.; Schneider, I. F.; Glass-Maujean, M.; Jungen, Ch.
2014-01-01
The predissociation of the 3pπD 1 Π u + ,v≥3,N=1, N = 2, and N = 3 levels of diatomic hydrogen is calculated by ab initio multichannel quantum defect theory combined with a R-matrix type approach that accounts for interfering predissociation and autoionization. The theory yields absorption line widths and shapes that are in good agreement with those observed in the high-resolution synchrotron vacuum-ultraviolet absorption spectra obtained by Dickenson et al. [J. Chem. Phys. 133, 144317 (2010)] at the DESIRS beamline of the SOLEIL synchrotron. The theory predicts further that many of the D state resonances with v ⩾ 6 exhibit a complex fine structure which cannot be modeled by the Fano profile formula and which has not yet been observed experimentally
International Nuclear Information System (INIS)
Yuan, J.; Zhang, Z.
1993-01-01
Spin polarizations (SP's) of elastic electron scattering from alkaline-earth-metal atoms in Ramsauer-Townsend (RT) and low-lying shape resonance (SR) regions are calculated using a relativistic method. The detailed SP distributions both with scattering angle and with electron energy are presented via the energy- and angle-dependent surfaces of SP parameters. It is shown that the SP effects of the collisions of electrons with Ca, Sr, and Ba atoms in the RT region are significant in a considerable area on the energy-angle plane and that the spin-orbit interaction is well increased around the low-lying p-wave SR states of Be and Mg and the d-wave SR states of Ca, Sr, and Ba
A Gauss-Newton method for the integration of spatial normal fields in shape Space
Balzer, Jonathan
2011-01-01
to solving a nonlinear least-squares problem in shape space. Previously, the corresponding minimization has been performed by gradient descent, which suffers from slow convergence and susceptibility to local minima. Newton-type methods, although significantly
Herrojo, Cristian; Mata-Contreras, Javier; Paredes, Ferran; Martín, Ferran
2017-11-01
The data density per surface (DPS) is a figure of merit in chipless radiofrequency identification (chipless-RFID) tags. In this paper, it is demonstrated that chipless-RFID tags with high DPS can be implemented by using double-chains of S-shaped split ring resonators (S-SRRs). Tag reading is achieved by near-field coupling between the tag and the reader, a CPW transmission line fed by a harmonic signal tuned to the resonance frequency of the S-SRRs. By transversally displacing the tag over the CPW, the transmission coefficient of the line is modulated by tag motion. This effectively modulates the amplitude of the injected (carrier) signal at the output port of the line, and the identification (ID) code, determined by the presence or absence of S-SRRs at predefined and equidistant positions in the chains, is contained in the envelope function. The DPS is determined by S-SRR dimensions and by the distance between S-SRRs in the chains. However, by using two chains of S-SRRs, the number of bits per unit length that can be accommodated is very high. This chipless-RFID system is of special interest in applications where the reading distance can be sacrificed in favor of data capacity (e.g., security and authentication). Encoding of corporate documents, ballots, exams, etc., by directly printing the proposed tags on the item product to prevent counterfeiting is envisaged.
Energy Technology Data Exchange (ETDEWEB)
Kivimäki, A., E-mail: kivimaki@iom.cnr.it [CNR—Istituto Officina dei Materiali (IOM), Laboratorio TASC, 34149 Trieste (Italy); Coreno, M. [CNR—Istituto di Struttura della Materia (ISM), Basovizza Area Science Park, 34149 Trieste (Italy); Miotti, P.; Frassetto, F.; Poletto, L. [CNR—Istituto di Fotonica e Nanotecnologie (IFN), via Trasea 7, 35131 Padova (Italy); Stråhlman, C. [MAX IV Laboratory, Lund University, P.O. Box 118, 22100 Lund (Sweden); Simone, M. de [CNR—Istituto Officina dei Materiali (IOM), Laboratorio TASC, 34149 Trieste (Italy); Richter, R. [Elettra-Sincrotrone Trieste, Area Science Park Basovizza, 34149 Trieste (Italy)
2016-05-15
Highlights: • The soft X-ray emission spectrum of SF{sub 6} changes at the S 2p → 4e{sub g} shape resonance. • The emission band around 172 eV indicates the population of the 6a{sub 1g} orbital. • Shake-up processes accompanying S 2p ionization can explain the new emissions. • Field ionization of neutral high Rydberg (HR) fragments reveals F and S atoms. • The yield of neutral HR fragments increases at the S 2p → 4e{sub g} shape resonance. - Abstract: We have studied the nature of the S 2p → 4e{sub g} shape resonance in the SF{sub 6} molecule by performing two different experiments. Soft X-ray emission spectra measured at the 4e{sub g} shape resonance reveal features that do not originate from the S 2p{sup −1} states. One of the features can be assigned to the 6a{sub 1g} → S 2p transition. The 6a{sub 1g} orbital, which is empty in the molecular ground state, can be populated either in core–valence double excitations or in S 2p shake-up transitions. Both these channels are considered. We have also studied the fragmentation of SF{sub 6} molecule after the decay of the S 2p core-hole states by observing neutral fragments in high-Rydberg states, where an electron occupies an orbital with n ≥ 20 (n is the principal quantum number). Such neutral fragments become, in relative terms, more abundant at the S 2p → 4e{sub g} shape resonance with respect to the S 2p → 2t{sub 2g} shape resonance, which is a pure one-electron phenomenon.
Directory of Open Access Journals (Sweden)
Paweł Olczyk
2017-01-01
Full Text Available Background. The evidence exists that radicals are crucial agents necessary for the wound regeneration helping to enhance the repair process. Materials and methods. The lineshape of the electron paramagnetic resonance (EPR spectra of the burn wounds measured with the low microwave power (2.2 mW was numerically analyzed. The experimental spectra were fitted by the sum of two and three lines. Results. The number of the lines in the EPR spectrum corresponded to the number of different groups of radicals in the natural samples after thermal treatment. The component lines were described by Gaussian and Lorentzian functions. The spectra of the burn wounds were superposition of three lines different in shape and in linewidths. The best fitting was obtained for the sum of broad Gaussian, broad Lorentzian, and narrow Lorentzian lines. Dipolar interactions between the unpaired electrons widened the broad Gaussian and broad Lorentzian lines. Radicals with the narrow Lorentzian lines existed mainly in the tested samples. Conclusions. The spectral shape analysis may be proposed as a useful method for determining the number of different groups of radicals in the burn wounds.
International Nuclear Information System (INIS)
Landa, Michal; Sedlak, Petr; Sittner, Petr; Seiner, Hanus; Heller, Ludek
2008-01-01
Elastic constants of austenite and martensite phases in shape memory alloys reflect fundamental thermodynamic properties of these materials-i.e. important physical information can be deduced not just from the values of the constants but, mainly from their temperature and stress dependencies. As regards to the parent austenite phase, such information is available in the literature for most of the known shape memory alloys. For the martensitic phases, however, only few reliable experimental data exist, due to the experimental difficulties with the preparation of martensite single crystals as well as due to the difficulties with the ultrasonic measurement of elastic properties of strongly anisotropic media with low symmetry. In this work, the temperature dependence of all elastic constants of cubic austenite and orthorhombic 2H martensite phases in Cu-Al-Ni alloy determined by resonance ultrasound spectroscopy (RUS) is reported. Experimental and theoretical improvements of the RUS method which had to be made to perform the successful measurements on strongly anisotropic and martensitic phases are discussed
International Nuclear Information System (INIS)
Martarelli, M; Castellini, P; Santolini, C; Tomasini, E P
2011-01-01
In rotating machinery, variations of modal parameters with rotation speed may be extremely important in particular for very light and undamped structures, such as helicopter rotors or wind turbines. The natural frequency dependence on rotation speed is conventionally measured by varying the rotor velocity and plotting natural frequencies versus speed in the so-called Campbell diagram. However, this kind of analysis does not give any information about the vibration spatial distribution i.e. the mode shape variation with the rotation speed must be investigated with dedicated procedures. In several cases it is not possible to fully control the rotating speed of the machine and only coast-down tests can be performed. Due to the reduced inertia of rotors, the coast-down process is usually an abrupt transient and therefore an experimental technique, able to determine operational deflection shapes (ODSs) in short time, with high spatial density and accuracy, appears very promising. Moreover coast-down processes are very difficult to control, causing unsteady vibrations. Hence, a very efficient approach for the rotation control and synchronous acquisition must be developed. In this paper a continuous scanning system able to measure ODSs and natural frequencies excited during rotor coast-down is shown. The method is based on a laser Doppler vibrometer (LDV) whose laser beam is driven to scan continuously over the rotor surface, in order to measure the ODS, and to follow the rotation of the rotor itself even in coast-down. With a single measurement the ODSs can be recovered from the LDV output time history in short time and with huge data saving. This technique has been tested on a laboratory test bench, i.e. a rotating two-blade fan, and compared with a series of non-contact approaches based on LDV: - traditional experimental modal analysis (EMA) results obtained under non-rotating conditions by measuring on a sequence of points on the blade surface excited by an impact
Dust around young stars. Observations of the polarization of UX Ori in deep minima
International Nuclear Information System (INIS)
Voshchinnikov, N.V.; Grinin, V.P.; Kiselev, N.N.; Minikulov, N.K.
1988-01-01
Photometric and polarimetric monitoring observations of UX Ori begun in 1986 in the Crimea and Bolivia have resulted in the observation of two deep minima of the brightness during which a growth of the linear polarization (to ≅7%) was observed, together with a tendency for the circular polarization to increase (up to ≅1%). Analysis of the observational data shows that the main source of the polarized radiation in the deep minima is the emission of the star scattered by grains of circumstellar dust. On the basis of Mie's theory for a polydisperse graphite-silicate mixtures of particles the optical properties of ellipsoidal dust envelopes have been calculated and a model of the Algol-like minimum constructed
Dynamical SUSY Breaking at Meta-Stable Minima from D-branes at Obstructed Geometries
Franco, S; Franco, Sebastian; Uranga, Angel M .
2006-01-01
We study the existence of long-lived meta-stable supersymmetry breaking vacua in gauge theories with massless quarks, upon the addition of extra massive flavors. A simple realization is provided by a modified version of SQCD with N_{f,0} < N_c massless flavors, N_{f,1} massive flavors and additional singlet chiral fields. This theory has local meta-stable minima separated from a runaway behavior at infinity by a potential barrier. We find further examples of such meta-stable minima in flavored versions of quiver gauge theories on fractional branes at singularities with obstructed complex deformations, and study the case of the dP_1 theory in detail. Finally, we provide an explicit String Theory construction of such theories. The additional flavors arise from D7-branes on non-compact 4-cycles of the singularity, for which we find a new efficient description using dimer techniques.
Flow-duration-frequency behaviour of British rivers based on annual minima data
Zaidman, Maxine D.; Keller, Virginie; Young, Andrew R.; Cadman, Daniel
2003-06-01
A comparison of different probability distribution models for describing the flow-duration-frequency behaviour of annual minima flow events in British rivers is reported. Twenty-five catchments were included in the study, each having stable and natural flow records of at least 30 years in length. Time series of annual minima D-day average flows were derived for each record using durations ( D) of 1, 7, 30, 60, 90, and 365 days and used to construct low flow frequency curves. In each case the Gringorten plotting position formula was used to determine probabilities (of non-exceedance). Four distribution types—Generalised Extreme Value (GEV), Generalised Logistic (GL), Pearson Type-3 (PE3) and Generalised Pareto (GP)—were used to model the probability distribution function for each site. L-moments were used to parameterise individual models, whilst goodness-of-fit tests were used to assess their match to the sample data. The study showed that where short durations (i.e. 60 days or less) were considered, high storage catchments tended to be best represented by GL and GEV distribution models whilst low storage catchments were best described by PE3 or GEV models. However, these models produced reasonable results only within a limited range (e.g. models for high storage catchments did not produce sensible estimates of return periods where the prescribed flow was less than 10% of the mean flow). For annual minima series derived using long duration flow averages (e.g. more than 90 days), GP and GEV models were generally more applicable. The study suggests that longer duration minima do not conform to the same distribution types as short durations, and that catchment properties can influence the type of distribution selected.
[Supercomputer investigation of the protein-ligand system low-energy minima].
Oferkin, I V; Sulimov, A V; Katkova, E V; Kutov, D K; Grigoriev, F V; Kondakova, O A; Sulimov, V B
2015-01-01
The accuracy of the protein-ligand binding energy calculations and ligand positioning is strongly influenced by the choice of the docking target function. This work demonstrates the evaluation of the five different target functions used in docking: functions based on MMFF94 force field and functions based on PM7 quantum-chemical method accounting or without accounting the implicit solvent model (PCM, COSMO or SGB). For these purposes the ligand positions corresponding to the minima of the target function and the experimentally known ligand positions in the protein active site (crystal ligand positions) were compared. Each function was examined on the same test-set of 16 protein-ligand complexes. The new parallelized docking program FLM based on Monte Carlo search algorithm was developed to perform the comprehensive low-energy minima search and to calculate the protein-ligand binding energy. This study demonstrates that the docking target function based on the MMFF94 force field can be used to detect the crystal or near crystal positions of the ligand by the finding the low-energy local minima spectrum of the target function. The importance of solvent accounting in the docking process for the accurate ligand positioning is also shown. The accuracy of the ligand positioning as well as the correlation between the calculated and experimentally determined protein-ligand binding energies are improved when the MMFF94 force field is substituted by the new PM7 method with implicit solvent accounting.
Tsuboyama, Takahiro; Jost, Gregor; Pietsch, Hubertus; Tomiyama, Noriyuki
2017-09-01
The aim of this study was to compare power versus manual injection in bolus shape and image quality on contrast-enhanced magnetic resonance angiography (CE-MRA). Three types of CE-MRA (head-neck 3-dimensional [3D] MRA with a test-bolus technique, thoracic-abdominal 3D MRA with a bolus-tracking technique, and thoracic-abdominal time-resolved 4-dimensional [4D] MRA) were performed after power and manual injection of gadobutrol (0.1 mmol/kg) at 2 mL/s in 12 pigs (6 sets of power and manual injections for each type of CE-MRA). For the quantitative analysis, the signal-to-noise ratio was measured on ascending aorta, descending aorta, brachiocephalic trunk, common carotid artery, and external carotid artery on the 6 sets of head-neck 3D MRA, and on ascending aorta, descending aorta, brachiocephalic trunk, abdominal aorta, celiac trunk, and renal artery on the 6 sets of thoracic-abdominal 3D MRA. Bolus shapes were evaluated on the 6 sets each of test-bolus scans and 4D MRA. For the qualitative analysis, arterial enhancement, superimposition of nontargeted enhancement, and overall image quality were evaluated on 3D MRA. Visibility of bolus transition was assessed on 4D MRA. Intraindividual comparison between power and manual injection was made by paired t test, Wilcoxon rank sum test, and analysis of variance by ranks. Signal-to-noise ratio on 3D MRA was statistically higher with power injection than with manual injection (P < 0.001). Bolus shapes (test-bolus, 4D MRA) were represented by a characteristic standard bolus curve (sharp first-pass peak followed by a gentle recirculation peak) in all the 12 scans with power injection, but only in 1 of the 12 scans with manual injection. Standard deviations of time-to-peak enhancement were smaller in power injection than in manual injection. Qualitatively, although both injection methods achieved diagnostic quality on 3D MRA, power injection exhibited significantly higher image quality than manual injection (P = 0.001) due to
VizieR Online Data Catalog: UY UMa and EF Boo compiled time of minima (Yu+, 2017)
Yu, Y.-X.; Zhang, X.-D.; Hu, K.; Xiang, F.-Y.
2017-11-01
In order to construct the (O-C) diagram to analyze the period change of UY UMa, we have performed a careful search for all available times of light minima. A total of 76 times of light minima were collected and listed in Table 2. >From the literatures and two well-known databases (i.e., the O-C gateway (http://var.astro.cz/ocgate) and the Lichtenknecker database of the BAV (http://www.bav-astro.de/LkDB/index.php)), we have collected a total of 75 available times of light minima for EF Boo, which are summarized in Table 3. (3 data files).
Energy Technology Data Exchange (ETDEWEB)
Chhipa, Mayur Kumar, E-mail: mayurchhipa1@gmail.com; Dusad, Lalit Kumar [Government Engineering College Ajmer, Rajasthan (India); Rajasthan Technical University, Kota, Rajasthan (India)
2016-05-06
In this paper, the design & performance of two dimensional (2-D) photonic crystal structure based channel drop filter is investigated using quad shaped photonic crystal ring resonator. In this paper, Photonic Crystal (PhC) based on square lattice periodic arrays of Gallium Indium Phosphide (GaInP) rods in air structure have been investigated using Finite Difference Time Domain (FDTD) method and photonic band gap is being calculated using Plane Wave Expansion (PWE) method. The PhC designs have been optimized for telecommunication wavelength λ= 1571 nm by varying the rods lattice constant. The number of rods in Z and X directions is 21 and 20, with lattice constant 0.540 nm it illustrates that the arrangement of Gallium Indium Phosphide (GaInP) rods in the structure which gives the overall size of the device around 11.4 µm × 10.8 µm. The designed filter gives good dropping efficiency using 3.298, refractive index. The designed structure is useful for CWDM systems. This device may serve as a key component in photonic integrated circuits. The device is ultra compact with the overall size around 123 µm{sup 2}.
2 µm high-power dissipative soliton resonance in a compact σ-shaped Tm-doped double-clad fiber laser
Du, Tuanjie; Li, Weiwei; Ruan, Qiujun; Wang, Kaijie; Chen, Nan; Luo, Zhengqian
2018-05-01
We report direct generation of a high-power, large-energy dissipative soliton resonance (DSR) in a 2 µm Tm-doped double-clad fiber laser. A compact σ-shaped cavity is formed by a fiber Bragg grating and a 10/90 fiber loop mirror (FLM). The 10/90 FLM is not only used as an output mirror, but also acts as a nonlinear optical loop mirror for initiating mode locking. The mode-locked laser can deliver high-power, nanosecond DSR pulses at 2005.9 nm. We further perform a comparison study of the effect of the FLM’s loop length on the mode-locking threshold, peak power, pulse energy, and optical spectrum of the DSR pulses. We achieve a maximum average output power as high as 1.4 W, a maximum pulse energy of 353 nJ, and a maximum peak power of 84 W. This is, to the best of our knowledge, the highest power for 2 µm DSR pulses obtained in a mode-locked fiber laser.
Polar and equatorial coronal hole winds at solar minima: From the heliosphere to the inner corona
Energy Technology Data Exchange (ETDEWEB)
Zhao, L.; Landi, E., E-mail: lzh@umich.edu [Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, MI 48105 (United States)
2014-02-01
Fast solar wind can be accelerated from at least two different sources: polar coronal holes and equatorial coronal holes. Little is known about the relationship between the wind coming from these two different latitudes and whether these two subcategories of fast wind evolve in the same way during the solar cycle. Nineteen years of Ulysses observations, from 1990 to 2009, combined with ACE observations from 1998 to the present provide us with in situ measurements of solar wind properties that span two entire solar cycles. These missions provide an ideal data set to study the properties and evolution of the fast solar wind originating from equatorial and polar holes. In this work, we focus on these two types of fast solar wind during the minima between solar cycles 22 and 23 and 23 and 24. We use data from SWICS, SWOOPS, and VHM/FGM on board Ulysses and SWICS, SWEPAM, and MAG on board ACE to analyze the proton kinetic, thermal, and dynamic characteristics, heavy ion composition, and magnetic field properties of these two fast winds. The comparison shows that: (1) their kinetic, thermal, compositional, and magnetic properties are significantly different at any time during the two minima and (2) they respond differently to the changes in solar activity from cycle 23 to 24. These results indicate that equatorial and polar fast solar wind are two separate subcategories of fast wind. We discuss the implications of these results and relate them to remote-sensing measurements of the properties of polar and equatorial coronal holes carried out in the inner corona during these two solar minima.
Polar and equatorial coronal hole winds at solar minima: From the heliosphere to the inner corona
International Nuclear Information System (INIS)
Zhao, L.; Landi, E.
2014-01-01
Fast solar wind can be accelerated from at least two different sources: polar coronal holes and equatorial coronal holes. Little is known about the relationship between the wind coming from these two different latitudes and whether these two subcategories of fast wind evolve in the same way during the solar cycle. Nineteen years of Ulysses observations, from 1990 to 2009, combined with ACE observations from 1998 to the present provide us with in situ measurements of solar wind properties that span two entire solar cycles. These missions provide an ideal data set to study the properties and evolution of the fast solar wind originating from equatorial and polar holes. In this work, we focus on these two types of fast solar wind during the minima between solar cycles 22 and 23 and 23 and 24. We use data from SWICS, SWOOPS, and VHM/FGM on board Ulysses and SWICS, SWEPAM, and MAG on board ACE to analyze the proton kinetic, thermal, and dynamic characteristics, heavy ion composition, and magnetic field properties of these two fast winds. The comparison shows that: (1) their kinetic, thermal, compositional, and magnetic properties are significantly different at any time during the two minima and (2) they respond differently to the changes in solar activity from cycle 23 to 24. These results indicate that equatorial and polar fast solar wind are two separate subcategories of fast wind. We discuss the implications of these results and relate them to remote-sensing measurements of the properties of polar and equatorial coronal holes carried out in the inner corona during these two solar minima.
Amin, Muhammad; Farhat, Mohamed; Bagci, Hakan
2014-01-01
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
Iterative h-minima-based marker-controlled watershed for cell nucleus segmentation.
Koyuncu, Can Fahrettin; Akhan, Ece; Ersahin, Tulin; Cetin-Atalay, Rengul; Gunduz-Demir, Cigdem
2016-04-01
Automated microscopy imaging systems facilitate high-throughput screening in molecular cellular biology research. The first step of these systems is cell nucleus segmentation, which has a great impact on the success of the overall system. The marker-controlled watershed is a technique commonly used by the previous studies for nucleus segmentation. These studies define their markers finding regional minima on the intensity/gradient and/or distance transform maps. They typically use the h-minima transform beforehand to suppress noise on these maps. The selection of the h value is critical; unnecessarily small values do not sufficiently suppress the noise, resulting in false and oversegmented markers, and unnecessarily large ones suppress too many pixels, causing missing and undersegmented markers. Because cell nuclei show different characteristics within an image, the same h value may not work to define correct markers for all the nuclei. To address this issue, in this work, we propose a new watershed algorithm that iteratively identifies its markers, considering a set of different h values. In each iteration, the proposed algorithm defines a set of candidates using a particular h value and selects the markers from those candidates provided that they fulfill the size requirement. Working with widefield fluorescence microscopy images, our experiments reveal that the use of multiple h values in our iterative algorithm leads to better segmentation results, compared to its counterparts. © 2016 International Society for Advancement of Cytometry. © 2016 International Society for Advancement of Cytometry.
STRUCTURE IN THE 3D GALAXY DISTRIBUTION. II. VOIDS AND WATERSHEDS OF LOCAL MAXIMA AND MINIMA
International Nuclear Information System (INIS)
Way, M. J.; Gazis, P. R.; Scargle, Jeffrey D.
2015-01-01
The major uncertainties in studies of the multi-scale structure of the universe arise not from observational errors but from the variety of legitimate definitions and detection methods for individual structures. To facilitate the study of these methodological dependencies, we have carried out 12 different analyses defining structures in various ways. This has been done in a purely geometrical way by utilizing the HOP algorithm as a unique parameter-free method of assigning groups of galaxies to local density maxima or minima. From three density estimation techniques (smoothing kernels, Bayesian blocks, and self-organizing maps) applied to three data sets (the Sloan Digital Sky Survey Data Release 7, the Millennium simulation, and randomly distributed points) we tabulate information that can be used to construct catalogs of structures connected to local density maxima and minima. We also introduce a void finder that utilizes a method to assemble Delaunay tetrahedra into connected structures and characterizes regions empty of galaxies in the source catalog
Directory of Open Access Journals (Sweden)
Xuejing Jia
2015-11-01
Full Text Available Box-Behnken design (BBD, one of the most common response surface methodology (RSM methods, was used to optimize the experimental conditions for ultrasound-assisted extraction of polysaccharides from Rhynchosia minima root (PRM. The antioxidant abilities and anticancer activity of purified polysaccharide fractions were also measured. The results showed that optimal extraction parameters were as follows: ultrasound exposure time, 21 min; ratio of water to material, 46 mL/g; ultrasound extraction temperature, 63 °C. Under these conditions, the maximum yield of PRM was 16.95% ± 0.07%. Furthermore, the main monosaccharides of purified fractions were Ara and Gal. PRM3 and PRM5 exhibited remarkable DPPH radical scavenging activities and reducing power in vitro. PRM3 showed strong inhibitory activities on the growth of MCF-7 cells in vitro. The above results indicate that polysaccharides from R. minima root have the potential to be developed as natural antioxidants and anticancer ingredients for the food and pharmaceutical industries.
Jia, Xuejing; Zhang, Chao; Hu, Jie; He, Muxue; Bao, Jiaolin; Wang, Kai; Li, Peng; Chen, Meiwan; Wan, Jianbo; Su, Huanxing; Zhang, Qingwen; He, Chengwei
2015-11-23
Box-Behnken design (BBD), one of the most common response surface methodology (RSM) methods, was used to optimize the experimental conditions for ultrasound-assisted extraction of polysaccharides from Rhynchosia minima root (PRM). The antioxidant abilities and anticancer activity of purified polysaccharide fractions were also measured. The results showed that optimal extraction parameters were as follows: ultrasound exposure time, 21 min; ratio of water to material, 46 mL/g; ultrasound extraction temperature, 63 °C. Under these conditions, the maximum yield of PRM was 16.95%±0.07%. Furthermore, the main monosaccharides of purified fractions were Ara and Gal. PRM3 and PRM5 exhibited remarkable DPPH radical scavenging activities and reducing power in vitro. PRM3 showed strong inhibitory activities on the growth of MCF-7 cells in vitro. The above results indicate that polysaccharides from R. minima root have the potential to be developed as natural antioxidants and anticancer ingredients for the food and pharmaceutical industries.
Energy Technology Data Exchange (ETDEWEB)
Ciller, Carlos, E-mail: carlos.cillerruiz@unil.ch [Department of Radiology, Lausanne University Hospital and University of Lausanne, Lausanne (Switzerland); Ophthalmic Technology Group, ARTORG Center of the University of Bern, Bern (Switzerland); Centre d’Imagerie BioMédicale, University of Lausanne, Lausanne (Switzerland); De Zanet, Sandro I.; Rüegsegger, Michael B. [Ophthalmic Technology Group, ARTORG Center of the University of Bern, Bern (Switzerland); Department of Ophthalmology, Inselspital, Bern University Hospital, Bern (Switzerland); Pica, Alessia [Department of Radiation Oncology, Inselspital, Bern University Hospital, Bern (Switzerland); Sznitman, Raphael [Ophthalmic Technology Group, ARTORG Center of the University of Bern, Bern (Switzerland); Department of Ophthalmology, Inselspital, Bern University Hospital, Bern (Switzerland); Thiran, Jean-Philippe [Department of Radiology, Lausanne University Hospital and University of Lausanne, Lausanne (Switzerland); Signal Processing Laboratory, École Polytechnique Fédérale de Lausanne, Lausanne (Switzerland); Maeder, Philippe [Department of Radiology, Lausanne University Hospital and University of Lausanne, Lausanne (Switzerland); Munier, Francis L. [Unit of Pediatric Ocular Oncology, Jules Gonin Eye Hospital, Lausanne (Switzerland); Kowal, Jens H. [Ophthalmic Technology Group, ARTORG Center of the University of Bern, Bern (Switzerland); Department of Ophthalmology, Inselspital, Bern University Hospital, Bern (Switzerland); and others
2015-07-15
Purpose: Proper delineation of ocular anatomy in 3-dimensional (3D) imaging is a big challenge, particularly when developing treatment plans for ocular diseases. Magnetic resonance imaging (MRI) is presently used in clinical practice for diagnosis confirmation and treatment planning for treatment of retinoblastoma in infants, where it serves as a source of information, complementary to the fundus or ultrasonographic imaging. Here we present a framework to fully automatically segment the eye anatomy for MRI based on 3D active shape models (ASM), and we validate the results and present a proof of concept to automatically segment pathological eyes. Methods and Materials: Manual and automatic segmentation were performed in 24 images of healthy children's eyes (3.29 ± 2.15 years of age). Imaging was performed using a 3-T MRI scanner. The ASM consists of the lens, the vitreous humor, the sclera, and the cornea. The model was fitted by first automatically detecting the position of the eye center, the lens, and the optic nerve, and then aligning the model and fitting it to the patient. We validated our segmentation method by using a leave-one-out cross-validation. The segmentation results were evaluated by measuring the overlap, using the Dice similarity coefficient (DSC) and the mean distance error. Results: We obtained a DSC of 94.90 ± 2.12% for the sclera and the cornea, 94.72 ± 1.89% for the vitreous humor, and 85.16 ± 4.91% for the lens. The mean distance error was 0.26 ± 0.09 mm. The entire process took 14 seconds on average per eye. Conclusion: We provide a reliable and accurate tool that enables clinicians to automatically segment the sclera, the cornea, the vitreous humor, and the lens, using MRI. We additionally present a proof of concept for fully automatically segmenting eye pathology. This tool reduces the time needed for eye shape delineation and thus can help clinicians when planning eye treatment and confirming the extent of the tumor.
Ciller, Carlos; De Zanet, Sandro I; Rüegsegger, Michael B; Pica, Alessia; Sznitman, Raphael; Thiran, Jean-Philippe; Maeder, Philippe; Munier, Francis L; Kowal, Jens H; Cuadra, Meritxell Bach
2015-07-15
Proper delineation of ocular anatomy in 3-dimensional (3D) imaging is a big challenge, particularly when developing treatment plans for ocular diseases. Magnetic resonance imaging (MRI) is presently used in clinical practice for diagnosis confirmation and treatment planning for treatment of retinoblastoma in infants, where it serves as a source of information, complementary to the fundus or ultrasonographic imaging. Here we present a framework to fully automatically segment the eye anatomy for MRI based on 3D active shape models (ASM), and we validate the results and present a proof of concept to automatically segment pathological eyes. Manual and automatic segmentation were performed in 24 images of healthy children's eyes (3.29 ± 2.15 years of age). Imaging was performed using a 3-T MRI scanner. The ASM consists of the lens, the vitreous humor, the sclera, and the cornea. The model was fitted by first automatically detecting the position of the eye center, the lens, and the optic nerve, and then aligning the model and fitting it to the patient. We validated our segmentation method by using a leave-one-out cross-validation. The segmentation results were evaluated by measuring the overlap, using the Dice similarity coefficient (DSC) and the mean distance error. We obtained a DSC of 94.90 ± 2.12% for the sclera and the cornea, 94.72 ± 1.89% for the vitreous humor, and 85.16 ± 4.91% for the lens. The mean distance error was 0.26 ± 0.09 mm. The entire process took 14 seconds on average per eye. We provide a reliable and accurate tool that enables clinicians to automatically segment the sclera, the cornea, the vitreous humor, and the lens, using MRI. We additionally present a proof of concept for fully automatically segmenting eye pathology. This tool reduces the time needed for eye shape delineation and thus can help clinicians when planning eye treatment and confirming the extent of the tumor. Copyright © 2015 Elsevier Inc. All rights reserved.
International Nuclear Information System (INIS)
Ciller, Carlos; De Zanet, Sandro I.; Rüegsegger, Michael B.; Pica, Alessia; Sznitman, Raphael; Thiran, Jean-Philippe; Maeder, Philippe; Munier, Francis L.; Kowal, Jens H.
2015-01-01
Purpose: Proper delineation of ocular anatomy in 3-dimensional (3D) imaging is a big challenge, particularly when developing treatment plans for ocular diseases. Magnetic resonance imaging (MRI) is presently used in clinical practice for diagnosis confirmation and treatment planning for treatment of retinoblastoma in infants, where it serves as a source of information, complementary to the fundus or ultrasonographic imaging. Here we present a framework to fully automatically segment the eye anatomy for MRI based on 3D active shape models (ASM), and we validate the results and present a proof of concept to automatically segment pathological eyes. Methods and Materials: Manual and automatic segmentation were performed in 24 images of healthy children's eyes (3.29 ± 2.15 years of age). Imaging was performed using a 3-T MRI scanner. The ASM consists of the lens, the vitreous humor, the sclera, and the cornea. The model was fitted by first automatically detecting the position of the eye center, the lens, and the optic nerve, and then aligning the model and fitting it to the patient. We validated our segmentation method by using a leave-one-out cross-validation. The segmentation results were evaluated by measuring the overlap, using the Dice similarity coefficient (DSC) and the mean distance error. Results: We obtained a DSC of 94.90 ± 2.12% for the sclera and the cornea, 94.72 ± 1.89% for the vitreous humor, and 85.16 ± 4.91% for the lens. The mean distance error was 0.26 ± 0.09 mm. The entire process took 14 seconds on average per eye. Conclusion: We provide a reliable and accurate tool that enables clinicians to automatically segment the sclera, the cornea, the vitreous humor, and the lens, using MRI. We additionally present a proof of concept for fully automatically segmenting eye pathology. This tool reduces the time needed for eye shape delineation and thus can help clinicians when planning eye treatment and confirming the extent of the tumor
Saba, Mohammad; Ebrahimi, Hossein Ali; Ahmadi-Pour, Habibeh; Khodadoust, Mohammad
2017-10-07
Background: Several studies indicate contribution of hypothalamus-pituitary-adrenal (HPA) axis in multiple sclerosis (MS) disease. This study was designed to determine whether there is an effective difference in pituitary height, shape, and anterior-posterior diameter (APD) between patients with MS and the control group. Methods: In this study, sagittal pituitary height and APD of 134 men and women (64 patients with MS and 70 healthy subjects as control group) were measured by T1 sequence magnetic resonance imaging (MRI). All the subjects were free of sellar or parasellar pathology without a history of surgical intervention or prolactin affecting drugs like bromocriptine and cabergoline or corticosteroid consumption. Results: Mean height of pituitary gland was 6.62 ± 1.43 and 5.78 ± 1.15 mm for patients and the control group, respectively, and the difference between the two groups was statistically significant (P = 0.001). Mean APD was 10.40 ± 1.29 mm for the group of patients and 10.25 ± 1.41 mm for the control group, respectively, without significant differences. 46.9%, 37.5%, and 15.6% of patients had flat, convex, and concave hypophyseal surfaces, respectively. This rate was 50%, 30%, and 20% among the control group, respectively. There was no significant difference between our measurements among patients on whom imaging study was performed at time of disease onset with others. Conclusion: Mean height of pituitary gland among patients with MS was significantly greater than the control group (P = 0.001). So can we consider the same etiology for pituitary hypertrophy among patients with MS as a hypothesis?
Anomalous Arctic surface wind patterns and their impacts on September sea ice minima and trend
Directory of Open Access Journals (Sweden)
Bingyi Wu
2012-05-01
Full Text Available We used monthly mean surface wind data from the National Centers for Environmental Prediction/National Centers for Atmospheric Research (NCEP/NCAR reanalysis dataset during the period 1979–2010 to describe the first two patterns of Arctic surface wind variability by means of the complex vector empirical orthogonal function (CVEOF analysis. The first two patterns respectively account for 31 and 16% of its total anomalous kinetic energy. The leading pattern consists of the two subpatterns: the northern Laptev Sea (NLS pattern and the Arctic dipole (AD pattern. The second pattern contains the northern Kara Sea (NKS pattern and the central Arctic (CA pattern. Over the past two decades, the combined dynamical forcing of the first two patterns has contributed to Arctic September sea ice extent (SIE minima and its declining trend. September SIE minima are mainly associated with the negative phase of the AD pattern and the positive phase of the CA pattern during the summer (July to September season, and both phases coherently show an anomalous anticyclone over the Arctic Ocean. Wind patterns affect September SIE through their frequency and intensity. The negative trend in September SIE over the past two decades is associated with increased frequency and enhanced intensity of the CA pattern during the melting season from April to September. Thus, it cannot be simply attributed to the AD anomaly characterised by the second empirical orthogonal function mode of sea level pressure north of 70°N. The CA pattern exhibited interdecadal variability in the late 1990s, and an anomalous cyclone prevailed before 1997 and was then replaced by an anomalous anticyclone over the Arctic Ocean that is consistent with the rapid decline trend in September SIE. This paper provides an alternative way to identify the dominant patterns of climate variability and investigate their associated Arctic sea ice variability from a dynamical perspective. Indeed, this study
Energy Technology Data Exchange (ETDEWEB)
Llacer, Jorge [EC Engineering Consultants, LLC 130, Forest Hill Drive, Los Gatos, CA (United States); Deasy, Joseph O [Department of Radiation Oncology, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO (United States); Bortfeld, Thomas R [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, 30 Fruit Street, Boston, MA (United States); Solberg, Timothy D [Department of Radiation Oncology, University of California, Los Angeles, CA (United States); Promberger, Claus [BrainLAB AG, Ammerthalstrasse 8, 85551 Heimstetten (Germany)
2003-01-21
This paper reports on the analysis of intensity modulated radiation treatment optimization problems in the presence of non-convex feasible parameter spaces caused by the specification of dose-volume constraints for the organs-at-risk (OARs). The main aim was to determine whether the presence of those non-convex spaces affects the optimization of clinical cases in any significant way. This was done in two phases: (1) Using a carefully designed two-dimensional mathematical phantom that exhibits two controllable minima and with randomly initialized beamlet weights, we developed a methodology for exploring the nature of the convergence characteristics of quadratic cost function optimizations (deterministic or stochastic). The methodology is based on observing the statistical behaviour of the residual cost at the end of optimizations in which the stopping criterion is progressively more demanding and carrying out those optimizations to very small error changes per iteration. (2) Seven clinical cases were then analysed with dose-volume constraints that are stronger than originally used in the clinic. The clinical cases are two prostate cases differently posed, a meningioma case, two head-and-neck cases, a spleen case and a spine case. Of the 14 different sets of optimizations (with and without the specification of maximum doses allowed for the OARs), 12 fail to show any effect due to the existence of non-convex feasible spaces. The remaining two sets of optimizations show evidence of multiple minima in the solutions, but those minima are very close to each other in cost and the resulting treatment plans are practically identical, as measured by the quality of the dose-volume histograms (DVHs). We discuss the differences between fluence maps resulting from those similar treatment plans. We provide a possible reason for the observed results and conclude that, although the study is necessarily limited, the annealing characteristics of a simulated annealing method may not be
Perthold, Jan Walther; Oostenbrink, Chris
2018-05-17
Enveloping distribution sampling (EDS) is an efficient approach to calculate multiple free-energy differences from a single molecular dynamics (MD) simulation. However, the construction of an appropriate reference-state Hamiltonian that samples all states efficiently is not straightforward. We propose a novel approach for the construction of the EDS reference-state Hamiltonian, related to a previously described procedure to smoothen energy landscapes. In contrast to previously suggested EDS approaches, our reference-state Hamiltonian preserves local energy minima of the combined end-states. Moreover, we propose an intuitive, robust and efficient parameter optimization scheme to tune EDS Hamiltonian parameters. We demonstrate the proposed method with established and novel test systems and conclude that our approach allows for the automated calculation of multiple free-energy differences from a single simulation. Accelerated EDS promises to be a robust and user-friendly method to compute free-energy differences based on solid statistical mechanics.
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.
Quantiifcation of methyl esters of fatty acids in the oil of Physalis minima by GC-MS
Institute of Scientific and Technical Information of China (English)
Muhammad Nasimullah Qureshi; Fazal Wajid; Inayat-ur-Rahman
2015-01-01
Objective:To investigate quantification of methyl esters of fatty acids in the oil extracted from Physalis minima (P. minima) using gas chromatography-mass spectrometer. Methods: Oil was extracted from the shade dried plant with n-hexane through Soxhlet extraction. Fatty acids that present in the oil were derivatized to fatty acid methyl esters and analysed through gas chromatography-mass spectrometer. Results:A total of nine fatty acids were detected in quantifiable amount in the oil. Both the saturated fatty acids and unsaturated fatty acids were identified. Palmitic acid was found in the highest concentration as 46.83%. Linoleic acid (ω-6) and linolenic acid (ω-3) were obtained in appreciable amount as 16.98%and 14.80%respectively among the unsaturated fatty acids in the oil under study. From the literature review, it appeared that fatty acids were determined for the first time in the oil of P. minima. Conclusions: Presence of these important fatty acids in high amount makes P. minima oil beneficial for health, which can be used in the preparation of phytopharmaceutical or pharmaceutical preparations. Moreover, the results of this study are useful for the phytopharmaceutical industries to establish their quality control profile.
Quantification of methyl esters of fatty acids in the oil of Physalis minima by GC-MS
Directory of Open Access Journals (Sweden)
Muhammad Nasimullah Qureshi
2015-02-01
Full Text Available Objective: To investigate quantification of methyl esters of fatty acids in the oil extracted from Physalis minima (P. minima using gas chromatography-mass spectrometer. Methods: Oil was extracted from the shade dried plant with n-hexane through Soxhlet extraction. Fatty acids that present in the oil were derivatized to fatty acid methyl esters and analysed through gas chromatography-mass spectrometer. Results: A total of nine fatty acids were detected in quantifiable amount in the oil. Both the saturated fatty acids and unsaturated fatty acids were identified. Palmitic acid was found in the highest concentration as 46.83%. Linoleic acid (ω-6 and linolenic acid (ω-3 were obtained in appreciable amount as 16.98% and 14.80% respectively among the unsaturated fatty acids in the oil under study. From the literature review, it appeared that fatty acids were determined for the first time in the oil of P. minima. Conclusions: Presence of these important fatty acids in high amount makes P. minima oil beneficial for health, which can be used in the preparation of phytopharmaceutical or pharmaceutical preparations. Moreover, the results of this study are useful for the phytopharmaceutical industries to establish their quality control profile.
Using vibrational Cooper minima to determine strong-field molecular-dissociation pathways
Severt, T.; Zohrabi, M.; Armstrong, G. S. J.; McKenna, J.; Gaire, B.; Kling, Nora G.; Ablikim, U.; Carnes, K. D.; Esry, B. D.; Ben-Itzhak, I.
2015-05-01
We explore the possibility of using vibrational ``Cooper minima'' (VCM) locations as a method to determine dissociation pathways of molecules in a strong laser field. As a test case, we study the laser-induced dissociation of an O2+ion beam by several wavelengths (λ = 800 , 400, and 266 nm) using a coincidence three-dimensional momentum imaging technique. Vibrational structure is observed in the kinetic energy release spectra, revealing a suppression of the dissociation of certain vibrational levels, which is a manifestation of the VCM effect. Previously, it has been shown in H2+that first-order time-dependent perturbation theory can be used to predict the locations of the VCM. We explore if the VCM locations predicted by perturbation theory can help uniquely identify dissociation pathways in O2+and consider its utility for other systems. Supported by the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy. TS was partially supported by NSF-REU under Grant No. PHY-0851599.
Exploration of minima on the C7H surface: Structural, stability- and ...
Indian Academy of Sciences (India)
index for aromaticity could distinguish well between aromatic, non-aromatic and anti-aromatic ... 7 isomers; cation stability; cation geometry; charge distribution; NICS; hybridization state; ..... resonance hybrid or as the most important canoni-.
International Nuclear Information System (INIS)
Kondev, F.G.; Carpenter, M.P.; Janssens, R.V.F.; Lister, C.J.; Abu Saleem, K.; Ahmad, I.; Amro, H.; Caggiano, J.; Davids, C.N.; Heinz, A.; Herskind, B.; Khoo, T.L.; Lauristen, T.; Ma, W.C.; Ressler, J.J.; Reviol, W.; Riedinger, L.L.; Sarantites, D.G.; Seweryniak, D.; Siem, S.; Sonzongni, A.A.; Varmette, P.G.; Wiedenhoever, I.
2002-01-01
Excited structures in the neutron-deficient nucleus 179 Hg have been established for the first time using the Gammasphere spectrometer in conjunction with the fragment mass analyzer. Competing states originating from three different minima associated with nearly spherical, oblate, and prolate deformations were found. This result can be contrasted with the situation in heavier odd-mass Hg isotopes where only two minima (oblate and prolate) have been seen. The implications of these three shapes at low spin and excitation energy are discussed in the general context of shape coexistence in this mass region.
International Nuclear Information System (INIS)
Jung, Yousung; Shao, Yihan; Gordon, Mark S.; Doren, Douglas J.; Head-Gordon, Martin
2003-01-01
We report a spin-unrestricted density functional theory (DFT) solution at the symmetric dimer structure for cluster models of Si(100). With this solution, it is shown that the symmetric structure is a minimum on the DFT potential energy surface, although higher in energy than the buckled structure. In restricted DFT calculations the symmetric structure is a saddle point connecting the two buckled minima. To further assess the effects of electron correlation on the relative energies of symmetric versus buckled dimers on Si(100), multireference second order perturbation theory (MRMP2) calculations are performed on these DFT optimized minima. The symmetric structure is predicted to be lower in energy than the buckled structure via MRMP2, while the reverse order is found by DFT. The implications for recent experimental interpretations are discussed
Directory of Open Access Journals (Sweden)
Dian Nugrahenny
2018-02-01
Full Text Available The administration of deoxy-corticosterone acetate (DOCA-salt can induce oxidative stress leading to decrease the bioavailability of nitric oxide (NO, increase senescence of circulating endothelial progenitor cells (EPCs, thus contributing to endothelial dysfunction. This study was aimed to investigate the effects of Physalis minima L. leaves extract on serum NO levels, circulating EPCs number, and histopathology of tail artery endothelial cells in DOCA-salt-induced endothelial dysfunction in rats. Twenty-five male Wistar rats were randomly divided into five groups: rats without any treatment (normal, rats treated with DOCA (10 mg/kgBW s.c. twice weekly and given 0.9% NaCl to drink ad libitum for 6 weeks, and DOCA-salt-induced rats orally supplemented with P. minima leaves extract at doses of 500, 1500, or 2500 mg/kgBW for 4 weeks. Serum NO levels were measured by colorimetry. The number of circulating EPCs (CD34+/CD133+ cells was determined by flow cytometry. The tail artery sections were histologically processed with hematoxylin-eosin staining. DOCA-salt-induced rats showed significantly (p<0.05 decrease in serum NO levels and circulating EPCs number compared to the normal. There was also more detached tail artery endothelial cells in DOCA-salt-induced rats. P. minima leaves extract at a dose of 500 mg/kgBW significantly (p<0.05 increased serum NO level and circulating EPCs number, and also induced an optimal re-endothelialization in DOCA-salt-induced rats. P. minima leave extract dose-dependently increases NO bioavailability contributing to enhanced EPCs mobilization, thereby promoting re-endothelialization in DOCA-salt-induced endothelial dysfunction in rats.
Czech Academy of Sciences Publication Activity Database
Vampola, T.; Horáček, Jaromír; Laukkanen, A. M.; Švec, J. G.
2015-01-01
Roč. 40, č. 1 (2015), s. 14-23 ISSN 1401-5439 R&D Projects: GA ČR(CZ) GAP101/12/1306 Institutional support: RVO:61388998 Keywords : acoustic mode shapes of vibration * speaker's and singer's formant * biomechanics of human voice * voice production modelling Subject RIV: BI - Acoustics Impact factor: 0.750, year: 2015
DEFF Research Database (Denmark)
Masharawi, Y; Kjær, Per; Manniche, C
2012-01-01
ABSTRACT: Study Design. A longitudinal descriptive MRI study on the changes of the supine lumbar lordosis (SLL), supine sacral slope (SSS), and sagittal wedging of the vertebral body (VB) and intervertebral discs (IVD) in children from the general population.Objective. To compare the shape...
Directory of Open Access Journals (Sweden)
Andrea Colombi
2017-08-01
Full Text Available In metamaterial science, local resonance and hybridization are key phenomena strongly influencing the dispersion properties; the metasurface discussed in this article created by a cluster of resonators, subwavelength rods, atop an elastic surface being an exemplar with these features. On this metasurface, band-gaps, slow or fast waves, negative refraction, and dynamic anisotropy can all be observed by exploring frequencies and wavenumbers from the Floquet–Bloch problem and by using the Brillouin zone. These extreme characteristics, when appropriately engineered, can be used to design and control the propagation of elastic waves along the metasurface. For the exemplar we consider, two parameters are easily tuned: rod height and cluster periodicity. The height is directly related to the band-gap frequency and, hence, to the slow and fast waves, while the periodicity is related to the appearance of dynamic anisotropy. Playing with these two parameters generates a gallery of metasurface designs to control the propagation of both flexural waves in plates and surface Rayleigh waves for half-spaces. Scalability with respect to the frequency and wavelength of the governing physical laws allows the application of these concepts in very different fields and over a wide range of lengthscales.
Ratnam, Challa; Lakshmana Rao, Vadlamudi; Lachaa Goud, Sivagouni
2006-10-01
In the present paper, and a series of papers to follow, the Fourier analytical properties of multiple annuli coded aperture (MACA) and complementary multiple annuli coded aperture (CMACA) systems are investigated. First, the transmission function for MACA and CMACA is derived using Fourier methods and, based on the Fresnel-Kirchoff diffraction theory, the formulae for the point spread function are formulated. The PSF maxima and minima are calculated for both the MACA and CMACA systems. The dependence of these properties on the number of zones is studied and reported in this paper.
International Nuclear Information System (INIS)
Ratnam, Challa; Rao, Vadlamudi Lakshmana; Goud, Sivagouni Lachaa
2006-01-01
In the present paper, and a series of papers to follow, the Fourier analytical properties of multiple annuli coded aperture (MACA) and complementary multiple annuli coded aperture (CMACA) systems are investigated. First, the transmission function for MACA and CMACA is derived using Fourier methods and, based on the Fresnel-Kirchoff diffraction theory, the formulae for the point spread function are formulated. The PSF maxima and minima are calculated for both the MACA and CMACA systems. The dependence of these properties on the number of zones is studied and reported in this paper
Marginal Shape Deep Learning: Applications to Pediatric Lung Field Segmentation.
Mansoor, Awais; Cerrolaza, Juan J; Perez, Geovanny; Biggs, Elijah; Nino, Gustavo; Linguraru, Marius George
2017-02-11
Representation learning through deep learning (DL) architecture has shown tremendous potential for identification, localization, and texture classification in various medical imaging modalities. However, DL applications to segmentation of objects especially to deformable objects are rather limited and mostly restricted to pixel classification. In this work, we propose marginal shape deep learning (MaShDL), a framework that extends the application of DL to deformable shape segmentation by using deep classifiers to estimate the shape parameters. MaShDL combines the strength of statistical shape models with the automated feature learning architecture of DL. Unlike the iterative shape parameters estimation approach of classical shape models that often leads to a local minima, the proposed framework is robust to local minima optimization and illumination changes. Furthermore, since the direct application of DL framework to a multi-parameter estimation problem results in a very high complexity, our framework provides an excellent run-time performance solution by independently learning shape parameter classifiers in marginal eigenspaces in the decreasing order of variation. We evaluated MaShDL for segmenting the lung field from 314 normal and abnormal pediatric chest radiographs and obtained a mean Dice similarity coefficient of 0.927 using only the four highest modes of variation (compared to 0.888 with classical ASM 1 (p-value=0.01) using same configuration). To the best of our knowledge this is the first demonstration of using DL framework for parametrized shape learning for the delineation of deformable objects.
Directory of Open Access Journals (Sweden)
JAUNATRE, Renaud
2018-01-01
Full Text Available Pour se protéger des crues en montagne, les hommes ont transformé et artificialisé les cours d’eau, avec comme conséquence une perte en surface d’habitats pour la biodiversité. Ainsi, les populations de petite massette (Typha minima Hoppe, plante des berges des cours d’eau, ont régressé de 85 % en un siècle dans les Alpes ! Aujourd’hui, la législation est plus attentive à la préservation de la biodiversité dans le cadre de projets d’aménagement et elle rend obligatoire un certain nombre de mesures permettant de compenser les impacts sur les écosystèmes. Pour les aménageurs du territoire, la restauration de populations de T. minima pose cependant des questions auxquelles cet article apporte des éléments de réponses.
Qin, Zhang-jian; Chen, Chuan; Luo, Jun-song; Xie, Xing-hong; Ge, Liang-quan; Wu, Qi-fan
2018-04-01
It is a usual practice for improving spectrum quality by the mean of designing a good shaping filter to improve signal-noise ratio in development of nuclear spectroscopy. Another method is proposed in the paper based on discriminating pulse-shape and discarding the bad pulse whose shape is distorted as a result of abnormal noise, unusual ballistic deficit or bad pulse pile-up. An Exponentially Decaying Pulse (EDP) generated in nuclear particle detectors can be transformed into a Mexican Hat Wavelet Pulse (MHWP) and the derivation process of the transform is given. After the transform is performed, the baseline drift is removed in the new MHWP. Moreover, the MHWP-shape can be discriminated with the three parameters: the time difference between the two minima of the MHWP, and the two ratios which are from the amplitude of the two minima respectively divided by the amplitude of the maximum in the MHWP. A new type of nuclear spectroscopy was implemented based on the new digital shaping filter and the Gamma-ray spectra were acquired with a variety of pulse-shape discrimination levels. It had manifested that the energy resolution and the peak-Compton ratio were both improved after the pulse-shape discrimination method was used.
International Nuclear Information System (INIS)
Ivanov, I. P.
2008-01-01
We continue to explore the consequences of the recently discovered Minkowski space structure of the Higgs potential in the two-Higgs-doublet model. Here, we focus on the vacuum properties. The search for extrema of the Higgs potential is reformulated in terms of 3-quadrics in the 3+1-dimensional Minkowski space. We prove that 2HDM cannot have more than two local minima in the orbit space and that a twice-degenerate minimum can arise only via spontaneous violation of a discrete symmetry of the Higgs potential. Investigating topology of the 3-quadrics, we give concise criteria for existence of noncontractible paths in the Higgs orbit space. We also study explicit symmetries of the Higgs potential/Lagrangian and their spontaneous violation from a wider perspective than usual
Uncertainty in the inelastic resonant scattering assisted by phonons
International Nuclear Information System (INIS)
Garcia, N.; Garcia-Sanz, J.; Solana, J.
1977-01-01
We have analyzed the inelastic minima observed in new results of He atoms scattered from LiF(001) surfaces. This is done considering bound state resonance processes assisted by phonons. The analysis presents large uncertainties. In the range of uncertainty, we find two ''possible'' bands associated with the vibrations of F - and Li + , respectively. Many more experimental data are necessary to confirm the existence of these processes
Energy Technology Data Exchange (ETDEWEB)
Fuentes, Ignacio I.; Espadas-Gil, Francisco; Talavera-May, Carlos; Fuentes, Gabriela; Santamaría, Jorge M., E-mail: jorgesm@cicy.mx
2014-10-15
Highlights: • We document the capacity of an aquatic fern to hyper-accumulate Ni. • Effects of high Ni concentrations uptake on plant performance is documented. • High concentration of Ni in tissues damage photosynthesis. • Damage is related to carboxylation mechanisms than to electron transfer efficiency. • S. minima is a good candidate for remediation of water bodies contaminated with Ni. - Abstract: An experiment was designed to assess the capacity of Salvinia minima Baker to uptake and accumulate nickel in its tissues and to evaluate whether or not this uptake can affect its physiology. Our results suggest that S. minima plants are able to take up high amounts of nickel in its tissues, particularly in roots. In fact, our results support the idea that S. minima might be considered a hyper-accumulator of nickel, as it is able to accumulate 16.3 mg g{sup −1} (whole plant DW basis). Our results also showed a two-steps uptake pattern of nickel, with a fast uptake of nickel at the first 6 to 12 h of being expose to the metal, followed by a slow take up phase until the end of the experiment at 144 h. S. minima thus, may be considered as a fern useful in the phytoremediation of residual water bodies contaminated with this metal. Also from our results, S. minima can tolerate fair concentrations of the metal; however, at concentrations higher than 80 μM Ni (1.5 mg g{sup −1} internal nickel concentration), its physiological performance can be affected. For instance, the integrity of cell membranes was affected as the metal concentration and exposure time increased. The accumulation of high concentrations of internal nickel did also affect photosynthesis, the efficiency of PSII, and the concentration of photosynthetic pigments, although at a lower extent.
Inductive Cross Shaped Metal Meshes in Silicon Substrate
National Research Council Canada - National Science Library
Sternberg, O; Moller, K. D; Grebel, H; Stewart, K. P; Henry, R. M
2002-01-01
.... The Micro-Stripes program was used for the calculation of resonance wavelength and width of resonance of cross shaped metal meshes and best- fit formulas were developed for the presentation of the data...
Covariant description of shape evolution and shape coexistence in neutron-rich nuclei at N≈60
International Nuclear Information System (INIS)
Xiang, J.; Li, Z.P.; Li, Z.X.; Yao, J.M.; Meng, J.
2012-01-01
The shape evolution and shape coexistence phenomena in neutron-rich nuclei at N≈60, including Kr, Sr, Zr, and Mo isotopes, are studied in the covariant density functional theory (DFT) with the new parameter set PC-PK1. Pairing correlations are treated using the BCS approximation with a separable pairing force. Sharp rising in the charge radii of Sr and Zr isotopes at N=60 is observed and shown to be related to the rapid changing in nuclear shapes. The shape evolution is moderate in neighboring Kr and Mo isotopes. Similar as the results of previous Hartree–Fock–Bogoliubov (HFB) calculations with the Gogny force, triaxiality is observed in Mo isotopes and shown to be essential to reproduce quantitatively the corresponding charge radii. In addition, the coexistence of prolate and oblate shapes is found in both 98 Sr and 100 Zr. The observed oblate and prolate minima are related to the low single-particle energy level density around the Fermi surfaces of neutron and proton respectively. Furthermore, the 5-dimensional (5D) collective Hamiltonian determined by the calculations of the PC-PK1 energy functional is solved for 98 Sr and 100 Zr. The resultant excitation energy of 0 2 + state and E0 transition strength ρ 2 (E0;0 2 + →0 1 + ) are in rather good agreement with the data. It is found that the lower barrier height separating the two competing minima along the γ deformation in 100 Zr gives rise to the larger ρ 2 (E0;0 2 + →0 1 + ) than that in 98 Sr.
International Nuclear Information System (INIS)
Stacey, V.J.
1984-01-01
The two laminarian brown algae Laminaria pallida Grev. ex. J. Ag. and Ecklonia maxima were studied. The red algae, growing attached to the brown algae namely, Carpoblepharis minima Bart. and Suhria vittata (L.) J. Ag. Pallida/C. minima and E. maxima/S. vittata associations were studied. Carpoblepharis minima has only been observed on L. pallida, whereas S. vittata has been found attached to various substrates as well as to E. maxima. Physiological studies were undertaken on both brown and red algae. Translocation was found to occur in the brown algae at a velocity of 50-100mm h- 1 in L. pallida and 240-300mm h- 1 in E. maxima after incubation in seawater containing 14 C-sodium bicarbonate (1μCi ml- 1 ). Movement of 14 C-assimilates in L. pallida was slower than in E. maxima probably due to a difference in the medulla structure. The only 14 C-labelled assimilates in the brown/red algal association were the acyclic polyol mannitol and certain amino acids. Mannitol was the major translocant in L. pallida and E. maxima. The mannitol concentration varied seasonally. Studies using 15 N-potassium nitrate showed that the major 'free' amino acids in L. pallida were alanine, glutamic acid and histadine, whereas in E. maxima they were alanine, glutamic acid and glutamine. The red algae contained mannitol and the major 'free' aminoacids were alanine, glutamine and histadine in C. minima and glutamine, glutamic acid and glycine in S. vittata. Both red algae were found to possess photosynthetic pigments, undergo 14 C-assimilation and to incorporate exogenously supplied mannitol. There was transfer of the 14 C-labelled assimilates of photosynthesis from the brown to the red algal partner in the L. pallida/C. minima association, but this did not occur in th E. maxima/S. vittata relationship
Data Analysis of Minima Total Cross-sections of Nitrogen-14 on JENDL-3.2Nuclear Data File
International Nuclear Information System (INIS)
Suwoto; Pandiangan, Tumpal; Ferhat-Aziz
2000-01-01
The integral tests of neutron cross-section for shielding material suchas nitrogen-14 contained in JENDL-3.2 file have been performed. Analysis ofthe calculation for nitrogen-14 was based on the MAEKER's ORNL-BroomstickExperiment at ORNL-USA. For the data comparison, the calculation analysiswith JENDL-3.1 file, ENDF/B-IV file, ENDF/B-VI file and JEF2.2 have also beencarried out. The overall calculation results by using JENDL-3.2 evaluationshowed good agreement with the experimental data, as well as those with theENDF/B-VI evaluation. In particular, the JENDL-3.2 evaluation gave betterresults than JENDL-3.1 evaluation and ENDF/B-IV. It was been concluded thatthe total cross-sections of Nitrogen-14 contained in JENDL-3.2 file is invery good agreement with the experimental results, although the totalcross-section in the energy range between 0.5 MeV and 0.9 MeV on fileJENDL-3.2 was small (about 4% lower), and minima of total cross-sections wasdeeper. (author)
Kitaura, Francisco-Shu; Chuang, Chia-Hsun; Liang, Yu; Zhao, Cheng; Tao, Charling; Rodríguez-Torres, Sergio; Eisenstein, Daniel J; Gil-Marín, Héctor; Kneib, Jean-Paul; McBride, Cameron; Percival, Will J; Ross, Ashley J; Sánchez, Ariel G; Tinker, Jeremy; Tojeiro, Rita; Vargas-Magana, Mariana; Zhao, Gong-Bo
2016-04-29
Sound waves from the primordial fluctuations of the Universe imprinted in the large-scale structure, called baryon acoustic oscillations (BAOs), can be used as standard rulers to measure the scale of the Universe. These oscillations have already been detected in the distribution of galaxies. Here we propose to measure BAOs from the troughs (minima) of the density field. Based on two sets of accurate mock halo catalogues with and without BAOs in the seed initial conditions, we demonstrate that the BAO signal cannot be obtained from the clustering of classical disjoint voids, but it is clearly detected from overlapping voids. The latter represent an estimate of all troughs of the density field. We compute them from the empty circumsphere centers constrained by tetrahedra of galaxies using Delaunay triangulation. Our theoretical models based on an unprecedented large set of detailed simulated void catalogues are remarkably well confirmed by observational data. We use the largest recently publicly available sample of luminous red galaxies from SDSS-III BOSS DR11 to unveil for the first time a >3σ BAO detection from voids in observations. Since voids are nearly isotropically expanding regions, their centers represent the most quiet places in the Universe, keeping in mind the cosmos origin and providing a new promising window in the analysis of the cosmological large-scale structure from galaxy surveys.
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...
Spectra of resonance surface photoionization
Energy Technology Data Exchange (ETDEWEB)
Antsiferov, V.V.; Smirnov, G.I.; Telegin, G.G. [Budker Nuclear Physics Institute, Novosibirsk (Russian Federation)
1995-09-01
The theory of nonactivated electron transfer between atoms interacting reasonantly with coherent radiation and a metal surface is developed. The spectral resonances in photoabsorption and surface photoionization are found to be related to nonlinear interference effects in the interaction between discrete atomic levels and the continuum formed by the quasi-continuous electron spectrum of a normal metal. The asymmetry in the resonance surface photoionization spectrum is shown to have a shape typical of the Fano autoionization resonances. 18 refs.
Energy Technology Data Exchange (ETDEWEB)
Miliordos, Evangelos; Aprà, Edoardo; Xantheas, Sotiris S.
2013-01-01
We report the first optimum geometries and harmonic vibrational frequencies for the ring pentamer and several water hexamer (prism, cage, cyclic and two book) at the CCSD(T)/aug-cc-pVDZ level of theory. All five hexamer isomer minima previously reported by MP2 are also minima on the CCSD(T) potential energy surface (PES). In addition, all CCSD(T) minimum energy structures for the n=2-6 cluster isomers are quite close to the ones previously obtained by MP2 on the respective PESs, as confirmed by a modified Procrustes analysis that quantifies the difference between any two cluster geometries. The CCSD(T) results confirm the cooperative effect of the homodromic ring networks (systematic contraction of the nearest-neighbor (nn) intermolecular separations with cluster size) previously reported by MP2, albeit with O-O distances shorter by ~0.02 Å, indicating that MP2 overcorrects this effect. The harmonic frequencies at the minimum geometries were obtained by the double differentiation of the CCSD(T) energy using an efficient scheme based on internal coordinates that reduces the number of required single point energy evaluations by ~15% when compared to the corresponding double differentiation using Cartesian coordinates. Negligible differences between MP2 and CCSD(T) are found for the librational modes, while uniform increases of ~15 and ~25 cm^{-1} are observed for the bending and “free” OH harmonic frequencies. The largest differences between MP2 and CCSD(T) are observed for the harmonic hydrogen bonded frequencies. The CCSD(T) red shifts from the monomer frequencies (Δω) are smaller than the MP2 ones, due to the fact that the former produces shorter elongations (ΔR) of the respective hydrogen bonded OH lengths from the monomer value with respect to the latter. Both the MP2 and CCSD(T) results for the hydrogen bonded frequencies were found to closely follow the relation - Δω = s · ΔR, with a rate of s = 20.3 cm^{-1} / 0.001 Å. The CCSD
Bohr model description of the critical point for the first order shape phase transition
Budaca, R.; Buganu, P.; Budaca, A. I.
2018-01-01
The critical point of the shape phase transition between spherical and axially deformed nuclei is described by a collective Bohr Hamiltonian with a sextic potential having simultaneous spherical and deformed minima of the same depth. The particular choice of the potential as well as the scaled and decoupled nature of the total Hamiltonian leads to a model with a single free parameter connected to the height of the barrier which separates the two minima. The solutions are found through the diagonalization in a basis of Bessel functions. The basis is optimized for each value of the free parameter by means of a boundary deformation which assures the convergence of the solutions for a fixed basis dimension. Analyzing the spectral properties of the model, as a function of the barrier height, revealed instances with shape coexisting features which are considered for detailed numerical applications.
Bohr model description of the critical point for the first order shape phase transition
Directory of Open Access Journals (Sweden)
R. Budaca
2018-01-01
Full Text Available The critical point of the shape phase transition between spherical and axially deformed nuclei is described by a collective Bohr Hamiltonian with a sextic potential having simultaneous spherical and deformed minima of the same depth. The particular choice of the potential as well as the scaled and decoupled nature of the total Hamiltonian leads to a model with a single free parameter connected to the height of the barrier which separates the two minima. The solutions are found through the diagonalization in a basis of Bessel functions. The basis is optimized for each value of the free parameter by means of a boundary deformation which assures the convergence of the solutions for a fixed basis dimension. Analyzing the spectral properties of the model, as a function of the barrier height, revealed instances with shape coexisting features which are considered for detailed numerical applications.
Evolving shape coexistence in the lead isotopes: The geometry of configuration mixing in nuclei
International Nuclear Information System (INIS)
Frank, Alejandro; Isacker, Piet van; Vargas, Carlos E.
2004-01-01
A matrix coherent-state approach is applied to the interacting boson model (IBM) with configuration mixing to describe the evolving geometry of neutron-deficient Pb isotopes. It is found that for small mixing with parameters determined previously, the potential energy surface of 186 Pb has three minima, which correspond to spherical, oblate, and prolate shapes, in agreement with recent measurements and mean-field calculations. Away from midshell, in the heavier Pb isotopes, no deformed minima occur. Our analysis suggests that the configuration-mixing IBM, used in conjunction with a matrix coherent-state method, may be a reliable tool for the study of geometric aspects of shape coexistence in nuclei
Directory of Open Access Journals (Sweden)
BABA SENOWBARI-DARYAN
2009-07-01
Full Text Available Two hypercalcified sphinctozoan sponges are described from several localities of dolomitic Norian reefs of northern Calabria (southern Italy. Solenolmia? parva n. sp. occurs as an extremely abundant, albeit local, component in peculiar bioconstructions dominated by serpulids and microbialitic crusts. Discosiphonella minima Senowbari-Daryan & Link, previously recognized only in the type locality of Turkey, has been now found also as a minor component in association with other typical "Dachstein" reef biota, such as corals, sponges, microbial crusts and fragments of "microproblematica". Solenolmia? parva assemblage represents the primary framebuilder of small build-ups which developed on the margins of restricted intraplatform basins. The Discosiphonella minima assemblages were found as resedimented blocks along the slope of intraplatform anoxic basins. The distribution of the different reefal assemblages of Northern Calabria can be related to the paleogeographic position of northern Calabria with respect to the evolution of Triassic crustal extension in western Mediterranean.
Evolution of nuclear shapes at high spins
International Nuclear Information System (INIS)
Johnson, N.R.
1985-01-01
The dynamic electric quadrupole (E2) moments are a direct reflection of the collective aspects of the nuclear wave functions. For this, Doppler-shift lifetime measurements have been done utilizing primarily the recoil-distance technique. The nuclei with neutron number N approx. 90 possess many interesting properties. These nuclei have very shallow minima in their potential energy surfaces, and thus, are very susceptible to deformation driving influences. It is the evolution of nuclear shapes as a function of spin or rotational frequency for these nuclei that has commanded much interest in the lifetime measurements discussed here. There is growing evidence that many deformed nuclei which have prolate shapes in their ground states conform to triaxial or oblate shapes at higher spins. Since the E2 matrix elements along the yrast line are sensitive indicators of deformation changes, measurements of lifetimes of these states to provide the matrix elements has become the major avenue for tracing the evolving shape of a nucleus at high spin. Of the several nuclei we have studied with N approx. 90, those to be discussed here are /sup 160,161/Yb and 158 Er. In addition, the preliminary, but interesting and surprising results from our recent investigation of the N = 98 nucleus, 172 W are briefly discussed. 14 refs., 5 figs
Listening to the Shape of a Drum
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 3; Issue 10. Listening to the Shape of a Drum - You Cannot Hear the Shape of a Drum! S Kesavan. General Article Volume 3 Issue 10 October 1998 pp 49-58. Fulltext. Click here to view fulltext PDF. Permanent link:
The shape of the melting curve and phase transitions in the liquid state
International Nuclear Information System (INIS)
Yahel, Eyal
2014-01-01
The phase diagram of elemental liquids has been found to be surprisingly rich, including variations in the melting curve and transitions in the liquid phase. The effect of these transitions on the shape of the melting curve is reviewed and analyzed. First-order phase transitions intersecting the melting curve imply piecewise continuous melting curves, with solid-solid transitions generating upward kinks or minima and liquid-liquid transitions generating downward kinks or maxima
CSIR Research Space (South Africa)
Forbes, A
2010-01-01
Full Text Available Laser, a high- power laser to shoot down missiles, fills an entire Boeing 747! By customising the laser resonator it is possible to design light to order. Laser technology has been around for 50 years, yet new research and ideas are ensuring... that it will remain an active area of investigation for years to come. ? Professor Andrew Forbes is Chief Researcher and Research Group Leader at the CSIR National Laser Centre, and holds honorary positions in the Schools of Physics at both the University...
International Nuclear Information System (INIS)
Kumar, K.
1980-01-01
The dynamic deformation model has been improved and applied to calculate the potential energies of deformation and the collective spectra of 16 O, 72 Se, and 240 Pu. A comprehensive view based on the dynamics of five-dimensional quadrupole motion is provided for three seemingly different types of shape coexistence: spherical (Op - Oh) and deformed (2p - 2h) shapes in 16 O, spherical and deformed minima in the potential energy surface of 72 Se, ground-state shape and the fission-isomer shape of 240 Pu. 5 figures, 3 tables
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).
Nanoparticle shape, thermodynamics and kinetics
International Nuclear Information System (INIS)
Marks, L D; Peng, L
2016-01-01
Nanoparticles can be beautiful, as in stained glass windows, or they can be ugly as in wear and corrosion debris from implants. We estimate that there will be about 70 000 papers in 2015 with nanoparticles as a keyword, but only one in thirteen uses the nanoparticle shape as an additional keyword and research focus, and only one in two hundred has thermodynamics. Methods for synthesizing nanoparticles have exploded over the last decade, but our understanding of how and why they take their forms has not progressed as fast. This topical review attempts to take a critical snapshot of the current understanding, focusing more on methods to predict than a purely synthetic or descriptive approach. We look at models and themes which are largely independent of the exact synthetic method whether it is deposition, gas-phase condensation, solution based or hydrothermal synthesis. Elements are old dating back to the beginning of the 20th century—some of the pioneering models developed then are still relevant today. Others are newer, a merging of older concepts such as kinetic-Wulff constructions with methods to understand minimum energy shapes for particles with twins. Overall we find that while there are still many unknowns, the broad framework of understanding and predicting the structure of nanoparticles via diverse Wulff constructions, either thermodynamic, local minima or kinetic has been exceedingly successful. However, the field is still developing and there remain many unknowns and new avenues for research, a few of these being suggested towards the end of the review. (topical review)
On channel selection and shape co-existence
International Nuclear Information System (INIS)
Dracoulis, G.D.
1993-08-01
Ambivalence with respect to a favoured shape is emerging as a ubiquitous phenomenon in nuclei. Multiple minima in the nuclear potential well occur because of the delicate balance in nuclei between the long and short-range properties of the nuclear force and the contribution specific particle orbitals make in forcing the nucleus to a decision. Exploration of the dependence of the resulting shape co-existence on particle number and orbital is a prominent area of research. Experimental aspects of spectroscopy studies using heavy ion fusion, evaporation reactions and channel selection are discussed, with focus on shape co-existence in the light Os-Pt-Hg-Pb region. 42 refs., 8 figs
International Nuclear Information System (INIS)
Shore, B.W.
1977-01-01
The long-time average of level populations in a coherently-excited anharmonic sequence of energy levels (e.g., an anharmonic oscillator) exhibits sharp resonances as a function of laser frequency. For simple linearly-increasing anharmonicity, each resonance is a superposition of various multiphoton resonances (e.g., a superposition of 3, 5, 7, . . . photon resonances), each having its own characteristic width predictable from perturbation theory
The digital holographic interferometry in resonant acoustic spectroscopy
International Nuclear Information System (INIS)
GAPONOV, V.E.; AZAMATOV, Z.T.; REDKORECHEV, V.I.; ISAEV, A.M.
2014-01-01
The opportunities of application of digital holographic interferometry method for studies of shapes of resonant modes in resonant acoustic spectroscopy are shown. The results of experimental measurements and analytical calculations are submitted. (authors)
International Nuclear Information System (INIS)
Kreiner, J.M.; Tremko, J.
1980-01-01
Changes were investigated in the shape of the light curve of the close binary TX Ursae Maioris in the vicinity of the primary minimum and changes in the period were analysed. It was proved that the change in the shape of the light curve was asymmetric and the effect on determining the minimum epoch was established. The hypothesis of the existence of the effect of the rotation of the line of apsides was disproved. It was found that processes leading to a change in the period occurred at least three times. In the first approximation the values of the periods in all intervals are constant. The run of the last change indicates that it did not occur suddenly but over a period of several years. The light changes during the recent period can be expressed by a linear ephemeris derived from the photoelectric epochs of the minimum. (author)
International Nuclear Information System (INIS)
1977-03-01
At the 1975 Particle Accelerator Conference it was reported that a class of resonances were observed in SPEAR II that had not appeared before in SPEAR I. While the existence of sideband resonances of the main betatron oscillation frequencies has been previously observed and analyzed, the resonances observed in SPEAR do not appear to be of the same variety. Experiments were performed at SPEAR to identify the mechanism believed to be the most likely explanation. Some of the current experimental knowledge and theoretical views on the source of these resonances are presented
International Nuclear Information System (INIS)
Tepikian, S.
1988-01-01
Siberian Snakes provide a practical means of obtaining polarized proton beams in large accelerators. The effect of snakes can be understood by studying the dynamics of spin precession in an accelerator with snakes and a single spin resonance. This leads to a new class of energy independent spin depolarizing resonances, called snake resonances. In designing a large accelerator with snakes to preserve the spin polarization, there is an added constraint on the choice of the vertical betatron tune due to the snake resonances. 11 refs., 4 figs
Togami, Izumi; Sasai, Nobuya; Tsunoda, Masatoshi; Sei, Tetsuro; Yabuki, Takayuki; Kitagawa, Takahiro; Mitani, Masahiko; Akaki, Shiro; Kuroda, Masahiro; Hiraki, Yoshio
2001-01-01
A preliminary study was conducted to evaluate the superior and inferior glenoid labra with abductive movement using an open-type MR unit in asymptomatic healthy volunteers. Both fast low angle shot (FLASH) and turbo spin echo (TSE) images were obtained to evaluate the shapes of both the superior and inferior labra, as well as to assess changes in signal at these sites. As the abduction angle was increased, the shape of the superior labrum changed from round or triangular to crescentic and a h...
The shape of soap films and Plateau borders
International Nuclear Information System (INIS)
Fortes, M A; Teixeira, P I C; Deus, A M
2007-01-01
We have calculated the shapes of flat liquid films, and of the transition region to the associated Plateau borders (PBs), by integrating the Laplace equation with a position-dependent surface tension γ(x), where 2x is the local film thickness. We discuss films in either zero or non-zero gravity, using standard γ(x) potentials for the interaction between the two bounding surfaces. We have investigated the effects of the film flatness, liquid underpressure, and gravity on the shape of films and their PBs. Films may exhibit 'humps' and/or 'dips' associated with inflection points and minima of the film thickness. Finally, we propose an asymptotic analytical solution for the film width profile
The shape of soap films and Plateau borders
Energy Technology Data Exchange (ETDEWEB)
Fortes, M A [Departamento de Engenharia de Materiais and Instituto de Ciencia e Engenharia de Materiais e SuperfIcies, Instituto Superior Tecnico, Avenida Rovisco Pais, P-1049-001 Lisbon (Portugal); Teixeira, P I C [Instituto Superior de Engenharia de Lisboa Rua Conselheiro EmIdio Navarro 1, P-1950-062 Lisbon (Portugal); Deus, A M [Departamento de Engenharia de Materiais and Instituto de Ciencia e Engenharia de Materiais e SuperfIcies, Instituto Superior Tecnico, Avenida Rovisco Pais, P-1049-001 Lisbon (Portugal)
2007-06-20
We have calculated the shapes of flat liquid films, and of the transition region to the associated Plateau borders (PBs), by integrating the Laplace equation with a position-dependent surface tension {gamma}(x), where 2x is the local film thickness. We discuss films in either zero or non-zero gravity, using standard {gamma}(x) potentials for the interaction between the two bounding surfaces. We have investigated the effects of the film flatness, liquid underpressure, and gravity on the shape of films and their PBs. Films may exhibit 'humps' and/or 'dips' associated with inflection points and minima of the film thickness. Finally, we propose an asymptotic analytical solution for the film width profile.
Shape mixing in sup(184,186)Hg
International Nuclear Information System (INIS)
Baba, C.V.K.
1976-01-01
Recent potential energy calculations on even Hg isotopes have shown that sup(184,186)Hg are possibly deformed with two energy minima one each for oblate (β 2 =-0.14) and prolate (β 2 =0.28) shapes. The quasi-rotational levels in these nuclei have been studied by heavy ion reactions at Berley and Chalk River. The salient features of these studies are: a deviation of the energy levels from a rotational sequence for I + →2 + and 2 + →0 + , E2 transition rates from the rotational value with β 2 =0.28. These features of the spectra are explained on the basis of mixing of bands based on the oblate and prolate shapes. The results of a simple band mixing calculation are presented and they reproduce the observed level spacings and B(E2) values. (author)
Calculation of the resonance cross section functions
International Nuclear Information System (INIS)
Slipicevic, K.F.
1967-11-01
This paper includes the procedure for calculating the Doppler broadened line shape functions ψ and χ which are needed for calculation of resonance cross section functions. The obtained values are given in tables
Calculation of the resonance cross section functions
Energy Technology Data Exchange (ETDEWEB)
Slipicevic, K F [Institute of nuclear sciences Boris Kidric, Vinca, Beograd (Yugoslavia)
1967-11-15
This paper includes the procedure for calculating the Doppler broadened line shape functions {psi} and {chi} which are needed for calculation of resonance cross section functions. The obtained values are given in tables.
International Nuclear Information System (INIS)
Yoon Jung-Sik; Jung Young-Dae
1999-01-01
Orientation phenomena for direct 1s→2p +-1 electron-ion collisional excitations in weakly coupled plasma are investigated using the semiclassical trajectory method including the close-encounter effects. In weakly coupled plasmas, the electron-ion interaction potential is given by the classical nonspherical Debye-Hueckel model. The semiclassical screened hyperbolic-orbit trajectory method is applied to describe the motion of the projectile electron in order to investigate the variation of the orientation parameter as a function of the impact parameter, projectile energy, and Debye length. A comparison is also given for the hyperbolic-orbit and straight-line trajectory methods. The results show that the orientation parameters obtained by the hyperbolic-orbit trajectory method have maxima and minima for small impact parameter regions. In other words, there are complete 1s→2p +1 (maxima) and complete 1s→2p -1 (minima) transitions for certain impact parameters. These maxima cannot be found using the straight-line trajectory method. The variation of the propensity of the 1s→2p -1 transitions due to the plasma screening effects on the atomic wave functions is also discussed
Energy Technology Data Exchange (ETDEWEB)
Peterson, David; Stofleth, Jerome H.; Saul, Venner W.
2017-07-11
Linear shaped charges are described herein. In a general embodiment, the linear shaped charge has an explosive with an elongated arrowhead-shaped profile. The linear shaped charge also has and an elongated v-shaped liner that is inset into a recess of the explosive. Another linear shaped charge includes an explosive that is shaped as a star-shaped prism. Liners are inset into crevices of the explosive, where the explosive acts as a tamper.
International Nuclear Information System (INIS)
Kobayasi, Masato; Matsuyanagi, Kenichi; Nakatsukasa, Takashi; Matsuo, Masayuki
2003-01-01
The adiabatic self-consistent collective coordinate method is applied to an exactly solvable multi-O(4) model that is designed to describe nuclear shape coexistence phenomena. The collective mass and dynamics of large amplitude collective motion in this model system are analyzed, and it is shown that the method yields a faithful description of tunneling motion through a barrier between the prolate and oblate local minima in the collective potential. The emergence of the doublet pattern is clearly described. (author)
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...
Periods, poles, and shapes of Saturn's irregular moons
Denk, Tilmann; Mottola, Stefano
2016-10-01
We report rotational-lightcurve observations of irregular moons of Saturn based on disk-integrated observations with the Narrow-Angle Camera of the Cassini spacecraft. From 24 measured rotation periods, 20 are now known with an accuracy of ~2% or better. The numbers are as follows (in hours; an '*' marks the less reliable periods): Hati 5.42; Mundilfari 6.74; Loge 6.94*; Skoll 7.26; Kari 7.70; Suttungr 7.82*, Bergelmir 8.13; Phoebe 9.274; Siarnaq 10.188; Narvi 10.21; Tarvos 10.69; Skathi 11.30; Ymir 11.922; Hyrrokkin 12.76; Greip 12.79*; Ijiraq 13.03; Albiorix 13.32; Bestla 14.624; Bebhionn 16.40; Paaliaq 18.75; Kiviuq 21.96; Erriapus 28.15; Thrymr 35 or >45* Tarqeq 76.8.More recent data strengthen the notion that objects in orbits with an inclination supplemental angle i' > 27° have significantly slower spin rates than those at i' 27°, Siarnaq, stands opposed to at least eight objects with faster spins and i' 27° bin contains all nine known prograde moons and four retrograde objects.A total of 25 out of 38 known outer moons has been observed with Cassini, and there is no chance to observe the 13 missing objects until end-of-mission. However, all unobserved objects are part of the i' 27° are known, and none of them is a fast rotator, with no exception.Several objects were observed repeatedly to determine pole directions, sidereal periods, and convex shapes. A few lightcurves have been observed to show three maxima and three minima even at low phase angles, suggesting objects with a triangular equatorial cross-section. Some objects with 2 maxima/ 2 minima are probably quite elongated. One moon even shows lightcurves with 4 maxima/ 4 minima.
Neutron resonance parameters of CM isotopes
International Nuclear Information System (INIS)
Belanova, T.S.; Kolesov, A.G.; Poruchikov, V.A.
1977-01-01
The total neutron cross sections of isotopes 244, 245, 246, 248 Curium have been measured on reactor CM-2 using the time-of-flight method. Single-level Breit-Wigner resonance parameters: energy E 0 , neutron width 2g GITAn, total width GITA, total neutron cross section in resonance sigma 0 have been obtained by the shape and area methods
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.
Liu, Jiamin; Udupa, Jayaram K
2009-04-01
Active shape models (ASM) are widely employed for recognizing anatomic structures and for delineating them in medical images. In this paper, a novel strategy called oriented active shape models (OASM) is presented in an attempt to overcome the following five limitations of ASM: 1) lower delineation accuracy, 2) the requirement of a large number of landmarks, 3) sensitivity to search range, 4) sensitivity to initialization, and 5) inability to fully exploit the specific information present in the given image to be segmented. OASM effectively combines the rich statistical shape information embodied in ASM with the boundary orientedness property and the globally optimal delineation capability of the live wire methodology of boundary segmentation. The latter characteristics allow live wire to effectively separate an object boundary from other nonobject boundaries with similar properties especially when they come very close in the image domain. The approach leads to a two-level dynamic programming method, wherein the first level corresponds to boundary recognition and the second level corresponds to boundary delineation, and to an effective automatic initialization method. The method outputs a globally optimal boundary that agrees with the shape model if the recognition step is successful in bringing the model close to the boundary in the image. Extensive evaluation experiments have been conducted by utilizing 40 image (magnetic resonance and computed tomography) data sets in each of five different application areas for segmenting breast, liver, bones of the foot, and cervical vertebrae of the spine. Comparisons are made between OASM and ASM based on precision, accuracy, and efficiency of segmentation. Accuracy is assessed using both region-based false positive and false negative measures and boundary-based distance measures. The results indicate the following: 1) The accuracy of segmentation via OASM is considerably better than that of ASM; 2) The number of landmarks
Screening Resonances In Plasmas
International Nuclear Information System (INIS)
Winkler, P.
1998-01-01
When it was suggested that a new recombination mechanism (Resonant Radiative Recombination (RRR)) which, based on very general physical arguments, should happen in dense plasmas and promises to provide useful information for the local temperature and density diagnostics of plasmas, they assumed the existence of screening resonances. For model potentials the existence of screening resonances has been demonstrated beyond reasonable doubt in a number of calculations. The key question, how well those potentials describe the dominant effects of a real plasma remains open. The relation of theoretical predictions to experimentally measurable effects is an important issue at the present stage of their research. In particular, RRR is expected to account for enhanced recombination rates of low energetic electrons with their ions, since the first stage is the resonant capture of a slow electron by an atom or ion. The mechanism that traps an electron is a combination of complicated many-body interactions of the ions and electrons. For clarity they start here, however, with a discussion in terms of local potential traps the shapes of which are determined predominantly and in an average way by two factors: the degree of screening present at the ionic site and the degree of short-range order in the immediate neighborhood of this ion
Nuclear magnetic resonance apparatus
International Nuclear Information System (INIS)
Lambert, R.
1991-01-01
In order to include the effect of a magnetic object in a subject under investigation, Nuclear Magnetic Resonance (NMR) apparatus is operable at more than one radio frequency (RF) frequency. The apparatus allows normal practice as far as obtaining an NMR response or image from a given nuclear species is concerned, but, in addition, interrogates the nuclear spin system at a frequency which is different from the resonance frequency normally used for the given nuclear species, as determined from the applied magnetic field. The magnetic field close to a magnetised or magnetisable object is modified and the given nuclear species gives a response at the different frequency. Thus detection of a signal at the frequency indicates the presence of the chosen nuclei close to the magnetised or magnetisable object. Applications include validation of an object detection or automatic shape inspection system in the presence of magnetic impurities, and the detection of magnetic particles which affect measurement of liquid flow in a pipe. (author)
Shapes of tree representations of spin-glass landscapes
International Nuclear Information System (INIS)
Hordijk, Wim; Fontanari, Jose F; Stadler, Peter F
2003-01-01
Much of the information about the multi-valley structure of disordered spin systems can be convened in a simple tree structure - a barrier tree - the leaves and internal nodes of which represent, respectively, the local minima and the lowest energy saddles connecting those minima. Here we apply several statistics used in the study of phylogenetic trees to barrier trees that result from the energy landscapes of p-spin models. These statistics give information about the shape of these barrier trees, in particular about balance and symmetry. We then ask if they can be used to classify different types of landscapes, compare them with results obtained from random trees, and investigate the structure of subtrees of the barrier trees. We conclude that at least one of the used statistics is capable of distinguishing different types of landscapes, that the barrier trees from p-spin energy landscapes are quite different from random trees, and that subtrees of barrier trees do not reflect the overall tree structure, but their structure is correlated with their 'depth' in the tree
International Nuclear Information System (INIS)
Fon, W.C.
1986-07-01
Recently, several electron scattering experiments using improved experimental techniques have been reported for Ar and Kr in the region of Ramsauer-Townsend minima. The calculations of Fon et al. on electrons colliding with inert-gas atoms are extended to examine these experimental data. These calculations using a single pseudo-state to account for the dipole polarisability of the ground state atom while ignoring a whole host of excitation mechanisms, have been the subject of considerable controversy (e.g. Reinhardt 1981; Walters 1981). The answers to the questions raised by Walters (1981) may well lie in the present calculation and those of Fon et al. (1983, 1984) in which the 1 P pseudo-states used in these calculations give polarisabilities at least 15% larger than the experimental values. (author)
International Nuclear Information System (INIS)
Lites, B.W.; Skumanich, A.; Rees, D.E.; Murphy, G.A.; Carlsson, M.; Sydney Univ., Australia; Oslo Universitetet, Norway)
1987-01-01
Observed Stokes profiles of Mg I 4571 A are analyzed as a diagnostic of the magnetic field and thermal structure at the temperature minimum of sunspot umbrae. Multilevel non-LTE transfer calculations of the Mg I-II-III excitation and ionization balance in model umbral atmospheres show: (1) Mg I to be far less ionized in sunspot umbrae than in the quiet sun, leading to greatly enhanced opacity in 4571 A, and (2) LTE excitation of 4571 A. Existing umbral models predict emission cores of the Stokes I profile due to the chromospheric temperature rise. This feature is not present in observed umbral profiles. Moreover, such an emission reversal causes similar anomalous features in the Stokes Q, U, V profiles, which are also not observed. Umbral atmospheres with extended temperature minima are suggested. Implications for chromospheric heating mechanisms and the utility of this line for solar vector magnetic field measurements are discussed. 35 references
Leal-Alvarado, Daniel A; Martínez-Hernández, A; Calderón-Vázquez, C L; Uh-Ramos, D; Fuentes, G; Ramírez-Prado, J H; Sáenz-Carbonell, L; Santamaría, J M
2017-12-01
Lead (Pb) is one of the most serious environmental pollutants. The aquatic fern Salvinia minima Baker is capable to hyper-accumulate Pb in their tissues. However, the molecular mechanisms involved in its Pb accumulation and tolerance capacity are not fully understood. In order to investigate the molecular mechanisms that are activated by S. minima in response to Pb, we constructed a suppression subtractive hybridization library (SSH) in response to an exposure to 40μM of Pb(NO 3 ) 2 for 12h. 365 lead-related differentially expressed sequences tags (ESTs) were isolated and sequenced. Among these ESTs, 143 unique cDNA (97 were registered at the GenBank and 46 ESTs were not registered, because they did not meet the GenBank conditions). Those ESTs were identified and classified into 3 groups according to Blast2GO. In terms of metabolic pathways, they were grouped into 29 KEGG pathways. Among the ESTs, we identified some that might be part of the mechanism that this fern may have to deal with this metal, including abiotic-stress-related transcription factors, some that might be involved in tolerance mechanisms such as ROS scavenging, membrane protection, and those of cell homeostasis recovery. To validate the SSH library, 4 genes were randomly selected from the library and analyzed by qRT-PCR. These 4 genes were transcriptionally up-regulated in response to lead in at least one of the two tested tissues (roots and leaves). The present library is one of the few genomics approaches to study the response to metal stress in an aquatic fern, representing novel molecular information and tools to understand the molecular physiology of its Pb tolerance and hyperaccumulation capacity. Further research is required to elucidate the functions of the lead-induced genes that remain classified as unknown, to perhaps reveal novel molecular mechanisms of Pb tolerance and accumulation capacity in aquatic plants. Copyright © 2017 Elsevier B.V. All rights reserved.
Quantum Computation with Ultrafast Laser Pulse Shaping
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 10; Issue 6. Quantum Computation with Ultrafast Laser Pulse Shaping. Debabrata Goswami. General Article Volume 10 Issue 6 June 2005 pp 8-14. Fulltext. Click here to view fulltext PDF. Permanent link:
Listening to the Shape of a Drum
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 3; Issue 9. Listening to the Shape of a Drum - The Mathematics of Vibrating Drums. S Kesavan. General Article Volume 3 Issue 9 September 1998 pp 26-34. Fulltext. Click here to view fulltext PDF. Permanent link:
Esposito, A.; Polosa, A.D.
2016-01-01
Multiquark resonances are undoubtedly experimentally observed. The number of states and the amount of details on their properties has been growing over the years. It is very recent the discovery of two pentaquarks and the confirmation of four tetraquarks, two of which had not been observed before. We mainly review the theoretical understanding of this sector of particle physics phenomenology and present some considerations attempting a coherent description of the so called X and Z resonances. The prominent problems plaguing theoretical models, like the absence of selection rules limiting the number of states predicted, motivate new directions in model building. Data are reviewed going through all of the observed resonances with particular attention to their common features and the purpose of providing a starting point to further research.
DEFF Research Database (Denmark)
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 stimuli. Unconscious self- pushing of limits result from innate distractive mechanisms offered by the alternative...... the unencumbered motion-to-computer-generated activities - ‘Music Making’, ‘Painting’, ‘Robotic’ and ‘Video Game’ control. A focus of this position paper is to highlight how Aesthetic Resonance, in this context, relates to the growing body of research on Neuroaesthetics to evolve Neuroaesthetic Resonance....
Peric, Mirna; Bales, Barney L; Peric, Miroslav
2012-03-22
The work in part 6 of this series (J. Phys. Chem. A 2009, 113, 4930), addressing the task of separating the effects of Heisenberg spin exchange (HSE) and dipole-dipole interactions (DD) on electron paramagnetic resonance (EPR) spectra of nitroxide spin probes in solution, is extended experimentally and theoretically. Comprehensive measurements of perdeuterated 2,2,6,6-tetramethyl-4-oxopiperidine-1-oxyl (pDT) in squalane, a viscous alkane, paying special attention to lower temperatures and lower concentrations, were carried out in an attempt to focus on DD, the lesser understood of the two interactions. Theoretically, the analysis has been extended to include the recent comprehensive treatment by Salikhov (Appl. Magn. Reson. 2010, 38, 237). In dilute solutions, both interactions (1) introduce a dispersion component, (2) broaden the lines, and (3) shift the lines. DD introduces a dispersion component proportional to the concentration and of opposite sign to that of HSE. Equations relating the EPR spectral parameters to the rate constants due to HSE and DD have been derived. By employing nonlinear least-squares fitting of theoretical spectra to a simple analytical function and the proposed equations, the contributions of the two interactions to items 1-3 may be quantified and compared with the same parameters obtained by fitting experimental spectra. This comparison supports the theory in its broad predictions; however, at low temperatures, the DD contribution to the experimental dispersion amplitude does not increase linearly with concentration. We are unable to deduce whether this discrepancy is due to inadequate analysis of the experimental data or an incomplete theory. A new key aspect of the more comprehensive theory is that there is enough information in the experimental spectra to find items 1-3 due to both interactions; however, in principle, appeal must be made to a model of molecular diffusion to separate the two. The permanent diffusion model is used to
Self-resonance after inflation: Oscillons, transients, and radiation domination
Lozanov, Kaloian D.; Amin, Mustafa A.
2018-01-01
Homogeneous oscillations of the inflaton after inflation can be unstable to small spatial perturbations even without coupling to other fields. We show that for inflaton potentials ∝|ϕ |2n near |ϕ |=0 and flatter beyond some |ϕ |=M , the inflaton condensate oscillations can lead to self-resonance, followed by its complete fragmentation. We find that for nonquadratic minima (n >1 ), shortly after backreaction, the equation of state parameter, w →1 /3 . If M ≪mPl, radiation domination is established within less than an e -fold of expansion after the end of inflation. In this case self-resonance is efficient and the condensate fragments into transient, localised spherical objects which are unstable and decay, leaving behind them a virialized field with mean kinetic and gradient energies much greater than the potential energy. This end-state yields w =1 /3 . When M ˜mPl we observe slow and steady, self-resonance that can last many e -folds before backreaction eventually shuts it off, followed by fragmentation and w →1 /3 . We provide analytical estimates for the duration to w →1 /3 after inflation, which can be used as an upper bound (under certain assumptions) on the duration of the transition between the inflationary and the radiation dominated states of expansion. This upper bound can reduce uncertainties in CMB observables such as the spectral tilt ns, and the tensor-to-scalar ratio r . For quadratic minima (n =1 ), w →0 regardless of the value of M . This is because when M ≪mPl, long-lived oscillons form within an e -fold after inflation, and collectively behave as pressureless dust thereafter. For M ˜mPl, the self-resonance is inefficient and the condensate remains intact (ignoring long-term gravitational clustering) and keeps oscillating about the quadratic minimum, again implying w =0 .
International Nuclear Information System (INIS)
Oset, E.; Sarkar, S.; Sun Baoxi; Vicente Vacas, M.J.; Ramos, A.; Gonzalez, P.; Vijande, J.; Martinez Torres, A.; Khemchandani, K.
2010-01-01
In this talk I show recent results on how many excited baryon resonances appear as systems of one meson and one baryon, or two mesons and one baryon, with the mesons being either pseudoscalar or vectors. Connection with experiment is made including a discussion on old predictions and recent results for the photoproduction of the Λ(1405) resonance, as well as the prediction of one 1/2 + baryon state around 1920 MeV which might have been seen in the γp→K + Λ reaction.
Indian Academy of Sciences (India)
IAS Admin
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Indian Academy of Sciences (India)
IAS Admin
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Indian Academy of Sciences (India)
IAS Admin
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International Nuclear Information System (INIS)
Anon.
1977-01-01
At the 1975 Particle Accelerator Conference it was reported that a class of resonances were observed in SPEAR II that had not appeared before in SPEAR I. These resonances occur when the betatron oscillation wave numbers ν/sub x/ or ν/sub y/ and the synchrotron wave number ν/sub s/ satisfy the relation (ν/sub x,y/ - mν/sub s/) = 5, with m an integer denoting the m/sup th/ satellite. The main difference between SPEAR II and SPEAR I is the value of ν/sub s/, which in SPEAR II is approximately 0.04, an order of magnitude larger than in SPEAR I. An ad hoc meeting was held at the 1975 Particle Accelerator Conference, where details of the SPEAR II results were presented and various possible mechanisms for producing these resonances were discussed. Later, experiments were performed at SPEAR to identify the mechanism believed to be the most likely explanation. Some of the current experimental knowledge and theoretical views on the source of these resonances are presented
Reinforced Airfoil Shaped Body
DEFF Research Database (Denmark)
2011-01-01
The present invention relates to an airfoil shaped body with a leading edge and a trailing edge extending along the longitudinal extension of the body and defining a profile chord, the airfoil shaped body comprising an airfoil shaped facing that forms the outer surface of the airfoil shaped body...
Giant resonances: reaction theory approach
International Nuclear Information System (INIS)
Toledo Piza, A.F.R. de; Foglia, G.A.
1989-09-01
The study of giant resonances through the use of reaction theory approach is presented and discussed. Measurements of cross-sections to the many available decay channels following excitation of giant multipole resonances (GMR) led one to view these phenomena as complicated dynamical syndromes so that theoretical requirements for their study must be extended beyond the traditional bounds of nuclear structure models. The spectra of decay products following GMR excitation in heavy nuclei are well described by statistical model (Hauser-Feshback, HF) predictions indicated that spreading of the collective modes plays a major role in shaping exclusive cross-sections. (A.C.A.S.) [pt
Energy Technology Data Exchange (ETDEWEB)
Wilson, Thomas S.; Bearinger, Jane P.
2017-08-29
New shape memory polymer compositions, methods for synthesizing new shape memory polymers, and apparatus comprising an actuator and a shape memory polymer wherein the shape memory polymer comprises at least a portion of the actuator. A shape memory polymer comprising a polymer composition which physically forms a network structure wherein the polymer composition has shape-memory behavior and can be formed into a permanent primary shape, re-formed into a stable secondary shape, and controllably actuated to recover the permanent primary shape. Polymers have optimal aliphatic network structures due to minimization of dangling chains by using monomers that are symmetrical and that have matching amine and hydroxl groups providing polymers and polymer foams with clarity, tight (narrow temperature range) single transitions, and high shape recovery and recovery force that are especially useful for implanting in the human body.
Wilson, Thomas S.; Bearinger, Jane P.
2015-06-09
New shape memory polymer compositions, methods for synthesizing new shape memory polymers, and apparatus comprising an actuator and a shape memory polymer wherein the shape memory polymer comprises at least a portion of the actuator. A shape memory polymer comprising a polymer composition which physically forms a network structure wherein the polymer composition has shape-memory behavior and can be formed into a permanent primary shape, re-formed into a stable secondary shape, and controllably actuated to recover the permanent primary shape. Polymers have optimal aliphatic network structures due to minimization of dangling chains by using monomers that are symmetrical and that have matching amine and hydroxyl groups providing polymers and polymer foams with clarity, tight (narrow temperature range) single transitions, and high shape recovery and recovery force that are especially useful for implanting in the human body.
Exotic nuclear shapes - Axial and nonaxial octupoles at normal and at super-deformation
Energy Technology Data Exchange (ETDEWEB)
Skalski, J [Soltan Inst. for Nuclear Studies, Otwock-Swierk (Poland); [Universite Libre de Bruxelles (Belgium); Heenen, P [Universite Libre de Bruxelles (Belgium); Bonche, P [CEA Centre d` Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France). Centre d` Application et de Promotion des Rayonnements Ionisants; Flocard, H [Paris-11 Univ., 91 - Orsay (France); Meyer, J [Lyon-1 Univ., 69 - Villeurbanne (France)
1992-08-01
We have studied collective octupole dynamics including nonaxial components of the octupole mean field, mainly at superdeformed shape in the Hg-Pb region. Both the Strutinsky method combined with cranking and the generator coordinate method within the self-consistent Hartree-Fock basis suggest the existence of collective octupole excitations at the superdeformed minima. GCM calculations point out to the E1 transitions as their most prominent experimental manifestation. We also comment on the nonaxial octupole components influence on octupole dynamics in traditional octupole region of Ra-Th nuclei. (author). 38 refs., 6 figs.
International Nuclear Information System (INIS)
Tkaczyk, Eric R.; Tkaczyk, Alan H.; Mauring, Koit; Ye, Jing Yong; Baker, James R.; Norris, Theodore B.
2010-01-01
We demonstrate that DiI and rhodamine B, which are not easily distinguishable to one-photon measurements, can be differentiated and in fact quantified in mixture via tailored two-photon excitation pulses found by a genetic algorithm (GA). A nearly three-fold difference in the ratio of two-photon fluorescence of the two dyes is achieved, without a drop in signal of the favored fluorophore. Implementing an acousto-optic interferometer, we were able to prove that the mechanism of discrimination is second-harmonic tuning by the phase-shaped pulses to the relative maxima and minima of these cross-sections.
Resonant non-Gaussianity with equilateral properties
International Nuclear Information System (INIS)
Gwyn, Rhiannon; Rummel, Markus
2012-11-01
We discuss the effect of superimposing multiple sources of resonant non-Gaussianity, which arise for instance in models of axion inflation. The resulting sum of oscillating shape contributions can be used to ''Fourier synthesize'' different non-oscillating shapes in the bispectrum. As an example we reproduce an approximately equilateral shape from the superposition of O(10) oscillatory contributions with resonant shape. This implies a possible degeneracy between the equilateral-type non-Gaussianity typical of models with non-canonical kinetic terms, such as DBI inflation, and an equilateral-type shape arising from a superposition of resonant-type contributions in theories with canonical kinetic terms. The absence of oscillations in the 2-point function together with the structure of the resonant N-point functions, imply that detection of equilateral non-Gaussianity at a level greater than the PLANCK sensitivity of f NL ∝O(5) will rule out a resonant origin. We comment on the questions arising from possible embeddings of this idea in a string theory setting.
Resonant non-Gaussianity with equilateral properties
Energy Technology Data Exchange (ETDEWEB)
Gwyn, Rhiannon [Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Potsdam (Germany); Rummel, Markus [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Westphal, Alexander [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
2012-11-15
We discuss the effect of superimposing multiple sources of resonant non-Gaussianity, which arise for instance in models of axion inflation. The resulting sum of oscillating shape contributions can be used to ''Fourier synthesize'' different non-oscillating shapes in the bispectrum. As an example we reproduce an approximately equilateral shape from the superposition of O(10) oscillatory contributions with resonant shape. This implies a possible degeneracy between the equilateral-type non-Gaussianity typical of models with non-canonical kinetic terms, such as DBI inflation, and an equilateral-type shape arising from a superposition of resonant-type contributions in theories with canonical kinetic terms. The absence of oscillations in the 2-point function together with the structure of the resonant N-point functions, imply that detection of equilateral non-Gaussianity at a level greater than the PLANCK sensitivity of f{sub NL} {proportional_to}O(5) will rule out a resonant origin. We comment on the questions arising from possible embeddings of this idea in a string theory setting.
Energy Technology Data Exchange (ETDEWEB)
Slabko, V V; Tsipotan, A S; Aleksandrovsky, A S [Institute of Engineering Physics and Radio Electronics, Siberian Federal University, Krasnoyarsk (Russian Federation)
2013-05-31
The influence of the oscillation phases of the dipole moments induced in metal nanoparticles and quantum dots by an external laser field on their interaction energy is considered. It is shown that a difference in resonant frequencies leads to the formation of additional minima and maxima, which are absent in the spectral dependence of the interaction energy of identical particles at similar orientations of the pair of particles with respect to the plane of polarisation of radiation. These features are due to the fact that the oscillation phase difference of the induced dipole moments of particles reaches values close to {pi}. (interaction of laser radiation with matter. laser plasma)
DEFF Research Database (Denmark)
Hjelholt, Morten; Jensen, Tina Blegind
2015-01-01
IT projects are often complex arrangements of technological components, social actions, and organizational transformation that are difficult to manage in practice. This paper takes an analytical discourse perspective to explore the process of legitimizing IT projects. We introduce the concept...... of resonating statements to highlight how central actors navigate in various discourses over time. Particularly, the statements and actions of an IT project manager are portrayed to show how individuals can legitimize actions by connecting statements to historically produced discourses. The case study...... as part of a feedback loop to re-attach the localized IT project to the broader national discourse. The paper concludes with reflections on how to actively build on resonating statements as a strategic resource for legitimizing IT projects...
Autoionization spectral line shapes in dense plasmas
International Nuclear Information System (INIS)
Rosmej, F.B.; Hoffmann, D.H.H.; Faenov, A.Ya.; Pikuz, T.A.; Suess, W.; Geissel, M.
2001-01-01
The distortion of resonance line shapes due to the accumulation of a large number of satellite transitions is discovered by means of X-ray optical methods with simultaneous high spectral (λ/δλ≅8000) and spatial resolution (δx≅7 μm). Disappearance of the He α resonance line emission near the target surface is observed while Rydberg satellite intensity accumulates near the resonance line position. He β and He γ resonance line shapes are also shown to be seriously affected by opacity, higher-order line emissions from autoionizing states and inhomogeneous spatial emission. Opposite to resonance line emissions the He β satellites originate only from a very narrow spatial interval. New temperature and density diagnostics employing the 1s2131' and 1s3131'-satellites are developed. Moreover, even-J components of the satellite line emissions were resolved in the present high resolution experiments. Line transitions from the autoionizing states 1s2131' are therefore also proposed for space resolved Stark broadening analysis and local high density probing. Theorists are encouraged to provide accurate Stark broadening data for the transitions 1s2131 ' →1s 2 21+hv
Gravitoelectromagnetic resonances
International Nuclear Information System (INIS)
Tsagas, Christos G.
2011-01-01
The interaction between gravitational and electromagnetic radiation has a rather long research history. It is well known, in particular, that gravity-wave distortions can drive propagating electromagnetic signals. Since forced oscillations provide the natural stage for resonances to occur, gravitoelectromagnetic resonances have been investigated as a means of more efficient gravity-wave detection methods. In this report, we consider the coupling between the Weyl and the Maxwell fields on a Minkowski background, which also applies to astrophysical environments where gravity is weak, at the second perturbative level. We use covariant methods that describe gravitational waves via the transverse component of the shear, instead of pure-tensor metric perturbations. The aim is to calculate the properties of the electromagnetic signal, which emerges from the interaction of its linear counterpart with an incoming gravitational wave. Our analysis shows how the wavelength and the amplitude of the gravitationally driven electromagnetic wave vary with the initial conditions. More specifically, for certain initial data, the amplitude of the induced electromagnetic signal is found to diverge. Analogous, diverging, gravitoelectromagnetic resonances were also reported in cosmology. Given that, we extend our Minkowski space study to cosmology and discuss analogies and differences in the physics and in the phenomenology of the Weyl-Maxwell coupling between the aforementioned two physical environments.
Magnetic resonance annual 1986
International Nuclear Information System (INIS)
Kressel, H.Y.
1986-01-01
This book contains papers written on magnetic resonance during 1986. Topics include: musculosketetal magnetic resonance imaging; imaging of the spine; magnetic resonance chemical shift imaging; magnetic resonance imaging in the central nervous system; comparison to computed tomography; high resolution magnetic resonance imaging using surface coils; magnetic resonance imaging of the chest; magnetic resonance imaging of the breast; magnetic resonance imaging of the liver; magnetic resonance spectroscopy of neoplasms; blood flow effects in magnetic resonance imaging; and current and potential applications of clinical sodium magnetic resonance imaging
Shen, Kai-kai; Fripp, Jurgen; Mériaudeau, Fabrice; Chételat, Gaël; Salvado, Olivier; Bourgeat, Pierrick; Saradha, A.; Abdi, Hervé; Abdulkadir, Ahmed; Acharya, Deepa; Achuthan, Anusha; Adluru, Nagesh; Aghajanian, Jania; Agrusti, Antonella; Agyemang, Alex; Ahdidan, Jamila; Ahmad, Duaa; Ahmed, Shiek; Aisen, Paul; Akhondi-Asl, Alireza; Aksu, Yaman; Alberca, Roman; Alcauter, Sarael; Alexander, Daniel; Alin, Aylin; Almeida, Fabio; Alvarez-Lineara, Juan; Amlien, Inge; Anand, Shyam; Anderson, Dallas; Ang, Amma; Angersbach, Steve; Ansarian, Reza; Aoyama, Eiji; Appannah, Arti; Arfanakis, Konstantinos; Armor, Tom; Arrighi, Michael; Arumughababu, S. Vethanayaki; Arunagiri, Vidhya; Ashe-McNalley, Cody; Ashford, Wes; Le Page, Aurelie; Avants, Brian; Aviv, Richard; Awasthi, Sukrati; Ayache, Nicholas; Chen, Wei; Richard, Edo; Schmand, Ben
2012-01-01
The hippocampus is affected at an early stage in the development of Alzheimer's disease (AD). With the use of structural magnetic resonance (MR) imaging, we can investigate the effect of AD on the morphology of the hippocampus. The hippocampal shape variations among a population can be usually
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 ...
International Nuclear Information System (INIS)
Lee, S.Y.
1993-01-01
We found that the perturbed spin tune due to the imperfection resonance plays an important role in beam depolarization at snake resonances. We also found that even order snake resonances exist in the overlapping intrinsic and imperfection resonances. Due to the perturbed spin tune shift of imperfection resonances, each snake resonance splits into two
DEFF Research Database (Denmark)
Rasmussen, Majken Kirkegård; Pedersen, Esben Warming; Petersen, Marianne Graves
2015-01-01
Shape change is increasingly used in physical user interfaces, both as input and output. Yet, the progress made and the key research questions for shape-changing interfaces are rarely analyzed systematically. We review a sample of existing work on shape-changing interfaces to address these shortc......Shape change is increasingly used in physical user interfaces, both as input and output. Yet, the progress made and the key research questions for shape-changing interfaces are rarely analyzed systematically. We review a sample of existing work on shape-changing interfaces to address...... these shortcomings. We identify eight types of shape that are transformed in various ways to serve both functional and hedonic design purposes. Interaction with shape-changing interfaces is simple and rarely merges input and output. Three questions are discussed based on the review: (a) which design purposes may...
Reading, Matthew W.
2017-07-04
Technologies for making self-erecting structures are described herein. An exemplary self-erecting structure comprises a plurality of shape-memory members that connect two or more hub components. When forces are applied to the self-erecting structure, the shape-memory members can deform, and when the forces are removed the shape-memory members can return to their original pre-deformation shape, allowing the self-erecting structure to return to its own original shape under its own power. A shape of the self-erecting structure depends on a spatial orientation of the hub components, and a relative orientation of the shape-memory members, which in turn depends on an orientation of joining of the shape-memory members with the hub components.
Magnetically coupled Fano resonance of dielectric pentamer oligomer
International Nuclear Information System (INIS)
Zhang, Fuli; Li, Chang; He, Xuan; Chen, Lei; Fan, Yuancheng; Zhao, Qian; Zhang, Weihong; Zhou, Ji
2017-01-01
We present magnetically induced Fano resonance inside a dielectric metamaterial pentamer composed of ceramic bricks. Unlike previous reports where different sizes of dielectric resonators were essential to produce Fano resonance, under external magnetic field excitation, central and outer dielectric bricks with identical sizes exhibit in-phase and out-of-phase magnetic Mie oscillations. An asymmetric line shape of Fano resonance along with enhanced group delay is observed due to the interference between the magnetic resonance of the central brick and the symmetric magnetic resonance of outer bricks. Besides, Fano resonance blueshifts with the increasing resonance of the smaller central brick. The thermal-dependent permittivity of ceramics allows Fano resonance to be reversibly tuned by 300 MHz when temperature varies by 60 °C. (paper)
Albertazzi, Liliana; Da Pos, Osvaldo; Canal, Luisa; Micciolo, Rocco; Malfatti, Michela; Vescovi, Massimo
2013-01-01
This article presents an experimental study on the naturally biased association between shape and color. For each basic geometric shape studied, participants were asked to indicate the color perceived as most closely related to it, choosing from the Natural Color System Hue Circle. Results show that the choices of color for each shape were not…
Dimitrova, M.; Cahyna, P.; Peterka, M.; Hasan, E.; Popov, Tsv K.; Ivanova, P.; Vasileva, E.; Panek, R.; Cavalier, J.; Seidl, J.; Markovic, T.; Havlicek, J.; Dejarnac, R.; Weinzettl, V.; Hacek, P.; Tomes, M.; the COMPASS Team; the EUROfusion MST1 Team
2018-02-01
The resonant magnetic perturbation (RMP) has proven to be a useful way to suppress edge-localized modes that under certain conditions can damage the device by the large power fluxes carried from the bulk plasma to the wall. The effect of RMP on the L-mode plasma parameters in the divertor region of the COMPASS tokamak was studied using the array of 39 Langmuir probes embedded into the divertor target. The current-voltage (IV) probe characteristics were processed by the first-derivative probe technique to obtain the plasma potential and the electron energy distribution function (EEDF) which was approximated by a bi-Maxwellian EEDF with a low-energy (4-6 eV) fraction and a high-energy (11-35 eV) one, the both factions having similar electron density. Clear splitting was observed during the RMP pulse in the low-field-side scrape-off-layer profiles of the floating potential U fl and the ion saturation current density J sat; these two quantities were obtained both by direct continuous measurement and by evaluation of the IV characteristics of probes with swept bias. The negative peaks of U fl induced by RMP spatially overlaps with the local minima of J sat (and n e) rather than with its local maxima which is partly caused by the spatial variation of the plasma potential and partly by the changed shape of the EEDF. The effective temperature of the whole EEDF is not correlated with the negative peaks of U fl, and the profile of the parallel power flux density shows secondary maxima due to RMP which mimic those of J sat.
Magnetic resonance imaging of muscle tears
International Nuclear Information System (INIS)
De Smet, A.A.; Fisher, D.R.; Heiner, J.P.; Keene, J.S.
1990-01-01
Magnetic resonance scans were obtained on 17 patients with acute, subacute, or chronic muscle tears. These patients presented with complaints of persistent pain or a palpable mass. Magnetic resonance findings were characterized according to alterations in muscle shape and the presence of abnormal high signal within the injured muscle. These areas of high signal were noted on both T1-weighted and T2-weighted scans and were presumed to represent areas of intramuscular hemorrhage. (orig.)
Shape coexistence of light, even A mercury isotopes
International Nuclear Information System (INIS)
Cole, J.D.
1978-01-01
The results of the studies of the decay of thallium isotopes establish the coexistence and crossing of two bands in the mercury isotopes. The two bands are built on states of different deformation. The band built upon the ground state has an associated small negative β value (oblate shape) while the second band has a large positive β value (prolate shape). The band heads for the deformed bands in the 184 186 188 Hg isotopes are established as 0 + levels at 375.2, 523.8, and 824.5 keV respectively. A comparison between the experimental results and the predictions of calculations based upon the coexistence of two different nuclear deformations has been made. The presence of two different deformations as described by two minima in the nuclear potential energy curve is termed ''shape coexistence.'' The good agreement of the calculations with the experimental results adds further support to the coexistence interpretation. The coexistence and crossing of two bands of different deformation explains the unusual behavior of the yrast level spacing that is referred to as 'backbending' when discussing moment of inertia versus rotational frequency plots based on the yrast levels. The studies of the 186 188 Pt levels have established the lower members of the ground state band and of a rotation-alignment band. The experimental results confirm the rotation-alignment explanation of backbending in the platinum cases discussed. (Auth.)
Nuclear Fusion Rate Study of a Muonic Molecule via Nuclear Threshold Resonances
Faghihi, F.; Eskandari, M. R.
This work follows our previous calculations of the ground state binding energy, size, and the effective nuclear charge of the muonic T3 molecule, using the Born-Oppenheimer adiabatic approximation. In our past articles, we showed that the system possesses two minimum positions, the first one at the muonic distance and the second at the atomic distance. Also, the symmetric planner vibrational model assumed between the two minima and the approximated potential were calculated. Following from the previous studies, we now calculate the fusion rate of the T3 muonic molecule according to the overlap integral of the resonance nuclear compound nucleus and the molecular wave functions.
DEFF Research Database (Denmark)
Winter, Pawel; Sterner, Henrik; Sterner, Peter
2009-01-01
We provide a unified description of (weighted) alpha shapes, beta shapes and the corresponding simplicialcomplexes. We discuss their applicability to various protein-related problems. We also discuss filtrations of alpha shapes and touch upon related persistence issues.We claim that the full...... potential of alpha-shapes and related geometrical constructs in protein-related problems yet remains to be realized and verified. We suggest parallel algorithms for (weighted) alpha shapes, and we argue that future use of filtrations and kinetic variants for larger proteins will need such implementation....
Perspectives of shaped pulses for EPR spectroscopy
Spindler, Philipp E.; Schöps, Philipp; Kallies, Wolfgang; Glaser, Steffen J.; Prisner, Thomas F.
2017-07-01
This article describes current uses of shaped pulses, generated by an arbitrary waveform generator, in the field of EPR spectroscopy. We show applications of sech/tanh and WURST pulses to dipolar spectroscopy, including new pulse schemes and procedures, and discuss the more general concept of optimum-control-based pulses for applications in EPR spectroscopy. The article also describes a procedure to correct for experimental imperfections, mostly introduced by the microwave resonator, and discusses further potential applications and limitations of such pulses.
International Nuclear Information System (INIS)
Kaszuwara, W.
2004-01-01
Shape memory alloys (SMA), when deformed, have the ability of returning, in certain circumstances, to their initial shape. Deformations related to this phenomenon are for polycrystals 1-8% and up to 15% for monocrystals. The deformation energy is in the range of 10 6 - 10 7 J/m 3 . The deformation is caused by martensitic transformation in the material. Shape memory alloys exhibit one directional or two directional shape memory effect as well as pseudoelastic effect. Shape change is activated by temperature change, which limits working frequency of SMA to 10 2 Hz. Other group of alloys exhibit magnetic shape memory effect. In these alloys martensitic transformation is triggered by magnetic field, thus their working frequency can be higher. Composites containing shape memory alloys can also be used as shape memory materials (applied in vibration damping devices). Another group of composite materials is called heterostructures, in which SMA alloys are incorporated in a form of thin layers The heterostructures can be used as microactuators in microelectromechanical systems (MEMS). Basic SMA comprise: Ni-Ti, Cu (Cu-Zn,Cu-Al, Cu-Sn) and Fe (Fe-Mn, Fe-Cr-Ni) alloys. Shape memory alloys find applications in such areas: automatics, safety and medical devices and many domestic appliances. Currently the most important appears to be research on magnetic shape memory materials and high temperature SMA. Vital from application point of view are composite materials especially those containing several intelligent materials. (author)
New properties of giant resonances in highly excited nuclei
International Nuclear Information System (INIS)
Morsch, H.P.
1991-01-01
Studies on the giant dipole resonance in very hot nuclei investigated in heavy ion-induced particle-γ coincidence experiments are reviewed. A signature is found in the γ-decay of excited nuceli which shows direct decay of the giant dipole resonance. This provides a new dimension in giant resonance studies and the possibility to study the dependence of giant resonance energy, width and sum rule strength on excitation energy and rotation of the system. Further, the fact that the giant resonance splits in deformed nuclei provides a unique way to get information on the shape of hot nuclei. First results are obtained on the following questions: (i)What is the nuclear shape at high temperature (T≥2 MeV)? (ii)Is there a phase transition in the nuclear shape at T∼1.7 MeV? (iii)Does motional narrowing exist in hot nuclei? (author). 19 refs., 11 figs
Applied neutron resonance theory
International Nuclear Information System (INIS)
Froehner, F.H.
1980-01-01
Utilisation of resonance theory in basic and applications-oriented neutron cross section work is reviewed. The technically important resonance formalisms, principal concepts and methods as well as representative computer programs for resonance parameter extraction from measured data, evaluation of resonance data, calculation of Doppler-broadened cross sections and estimation of level-statistical quantities from resonance parameters are described. (author)
Applied neutron resonance theory
International Nuclear Information System (INIS)
Froehner, F.H.
1978-07-01
Utilisation of resonance theory in basic and applications-oriented neutron cross section work is reviewed. The technically important resonance formalisms, principal concepts and methods as well as representative computer programs for resonance parameter extraction from measured data, evaluation of resonance data, calculation of Doppler-broadened cross sections and estimation of level-statistical quantities from resonance parameters are described. (orig.) [de
A parity checker circuit based on microelectromechanical resonator logic elements
Hafiz, Md Abdullah Al
2017-01-11
Micro/nano-electromechanical resonator based logic computation has attracted significant attention in recent years due to its dynamic mode of operation, ultra-low power consumption, and potential for reprogrammable and reversible computing. Here we demonstrate a 4-bit parity checker circuit by utilizing recently developed logic gates based on MEMS resonators. Toward this, resonance frequencies of shallow arch shaped micro resonators are electrothermally tuned by the logic inputs to constitute the required logic gates for the proposed parity checker circuit. This study demonstrates that by utilizing MEMS resonator based logic elements, complex digital circuits can be realized.
A parity checker circuit based on microelectromechanical resonator logic elements
Hafiz, Md Abdullah Al; Li, Ren; Younis, Mohammad I.; Fariborzi, Hossein
2017-01-01
Micro/nano-electromechanical resonator based logic computation has attracted significant attention in recent years due to its dynamic mode of operation, ultra-low power consumption, and potential for reprogrammable and reversible computing. Here we demonstrate a 4-bit parity checker circuit by utilizing recently developed logic gates based on MEMS resonators. Toward this, resonance frequencies of shallow arch shaped micro resonators are electrothermally tuned by the logic inputs to constitute the required logic gates for the proposed parity checker circuit. This study demonstrates that by utilizing MEMS resonator based logic elements, complex digital circuits can be realized.
Chenciner, Alain; Venturelli, Andrea
2000-09-01
We consider the problem of 4 bodies of equal masses in R 3 for the Newtonian r-1 potential. We address the question of the absolute minima of the action integral among (anti)symmetric loops of class H 1 whose period is fixed. It is the simplest case for which the results of [4] (corrected in [5]) do not apply: the minima cannot be the relative equilibria whose configuration is an absolute minimum of the potential among the configurations having a given moment of inertia with respect to their center of mass. This is because the regular tetrahedron cannot have a relative equilibrium motion in R 3 (see [2]). We show that the absolute minima of the action are not homographic motions. We also show that if we force the configuration to admit a certain type of symmetry of order 4, the absolute minimum is a collisionless orbit whose configuration ‘hesitates’ between the central configuration of the square and the one of the tetrahedron. We call these orbits ‘hip-hop’. A similar result holds in case of a symmetry of order 3 where the central configuration of the equilateral triangle with a body at the center of mass replaces the square.
International Nuclear Information System (INIS)
Mackintosh, R.S.
1977-01-01
For the class of nuclei which are 'strongly deformed' it is possible to introduce the idea of an empirically measurable static nuclear shape. The limitations of this concept as applied to nuclei (fundamentally quantum-mechanical objects) are discussed. These are basically the limitations of the rotational model which must be introduced in order to define and measure nuclear shape. A unified discussion of the ways in which the shape has been parametrized is given with emphasis on the fact that different parametrizations correspond to different nuclear structures. Accounts of the various theoretical procedures for calculating nuclear shapes and of the interaction between nuclear shapes and nuclear spectroscopy are given. A coherent account of a large subset of nuclei (strongly deformed nuclei) can be given by means of a model in which the concept of nuclear shape plays a central role. (author)
Leonard, Kathryn; Tari, Sibel; Hubert, Evelyne; Morin, Geraldine; El-Zehiry, Noha; Chambers, Erin
2018-01-01
Based on the second Women in Shape (WiSH) workshop held in Sirince, Turkey in June 2016, these proceedings offer the latest research on shape modeling and analysis and their applications. The 10 peer-reviewed articles in this volume cover a broad range of topics, including shape representation, shape complexity, and characterization in solving image-processing problems. While the first six chapters establish understanding in the theoretical topics, the remaining chapters discuss important applications such as image segmentation, registration, image deblurring, and shape patterns in digital fabrication. The authors in this volume are members of the WiSH network and their colleagues, and most were involved in the research groups formed at the workshop. This volume sheds light on a variety of shape analysis methods and their applications, and researchers and graduate students will find it to be an invaluable resource for further research in the area.
Perspectives in shape analysis
Bruckstein, Alfred; Maragos, Petros; Wuhrer, Stefanie
2016-01-01
This book presents recent advances in the field of shape analysis. Written by experts in the fields of continuous-scale shape analysis, discrete shape analysis and sparsity, and numerical computing who hail from different communities, it provides a unique view of the topic from a broad range of perspectives. Over the last decade, it has become increasingly affordable to digitize shape information at high resolution. Yet analyzing and processing this data remains challenging because of the large amount of data involved, and because modern applications such as human-computer interaction require real-time processing. Meeting these challenges requires interdisciplinary approaches that combine concepts from a variety of research areas, including numerical computing, differential geometry, deformable shape modeling, sparse data representation, and machine learning. On the algorithmic side, many shape analysis tasks are modeled using partial differential equations, which can be solved using tools from the field of n...
International Nuclear Information System (INIS)
Balick, B.
1987-01-01
The phases of stellar evolution and the development of planetary nebulae are examined. The relation between planetary nebulae and red giants is studied. Spherical and nonspherical cases of shaping planetaries with stellar winds are described. CCD images of nebulae are analyzed, and it is determined that the shape of planetary nebulae depends on ionization levels. Consideration is given to calculating the distances of planetaries using radio images, and molecular hydrogen envelopes which support the wind-shaping model of planetary nebulae
Linear signal processing using silicon micro-ring resonators
DEFF Research Database (Denmark)
Peucheret, Christophe; Ding, Yunhong; Ou, Haiyan
2012-01-01
We review our recent achievements on the use of silicon micro-ring resonators for linear optical signal processing applications, including modulation format conversion, phase-to-intensity modulation conversion and waveform shaping.......We review our recent achievements on the use of silicon micro-ring resonators for linear optical signal processing applications, including modulation format conversion, phase-to-intensity modulation conversion and waveform shaping....
A parity checker circuit based on microelectromechanical resonator logic elements
Energy Technology Data Exchange (ETDEWEB)
Hafiz, Md Abdullah Al, E-mail: abdullah.hafiz@kaust.edu.sa [CEMSE Division, King Abdullah University of Science and Technology, Thuwal (Saudi Arabia); Li, Ren [CEMSE Division, King Abdullah University of Science and Technology, Thuwal (Saudi Arabia); Younis, Mohammad I. [PSE Division, King Abdullah University of Science and Technology, Thuwal (Saudi Arabia); Fariborzi, Hossein [CEMSE Division, King Abdullah University of Science and Technology, Thuwal (Saudi Arabia)
2017-03-03
Micro/nano-electromechanical resonator based logic computation has attracted significant attention in recent years due to its dynamic mode of operation, ultra-low power consumption, and potential for reprogrammable and reversible computing. Here we demonstrate a 4-bit parity checker circuit by utilizing recently developed logic gates based on MEMS resonators. Toward this, resonance frequencies of shallow arch shaped micro-resonators are electrothermally tuned by the logic inputs to constitute the required logic gates for the proposed parity checker circuit. This study demonstrates that by utilizing MEMS resonator based logic elements, complex digital circuits can be realized. - Highlights: • A 4-bit parity checker circuit is proposed and demonstrated based on MEMS resonator based logic elements. • Multiple copies of MEMS resonator based XOR logic gates are used to construct a complex logic circuit. • Functionality and feasibility of micro-resonator based logic platform is demonstrated.
International Nuclear Information System (INIS)
Kajdalov, A.B.
1986-01-01
Experimental data on np interactions indicating to existence of narrow resonances in pp-system are discussed. Possible theoretical interpretations of these resonances are given. Experimental characteristics of the dibaryon resonances with isospin I=2 are considered
MRI (Magnetic Resonance Imaging)
... Procedures Medical Imaging MRI (Magnetic Resonance Imaging) MRI (Magnetic Resonance Imaging) Share Tweet Linkedin Pin it More sharing options Linkedin Pin it Email Print Magnetic Resonance Imaging (MRI) is a medical imaging procedure for ...
Regenerative feedback resonant circuit
Jones, A. Mark; Kelly, James F.; McCloy, John S.; McMakin, Douglas L.
2014-09-02
A regenerative feedback resonant circuit for measuring a transient response in a loop is disclosed. The circuit includes an amplifier for generating a signal in the loop. The circuit further includes a resonator having a resonant cavity and a material located within the cavity. The signal sent into the resonator produces a resonant frequency. A variation of the resonant frequency due to perturbations in electromagnetic properties of the material is measured.
Resonance – Journal of Science Education | Indian Academy of ...
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education. S Kesavan. Articles written in Resonance – Journal of Science Education. Volume 3 Issue 9 September 1998 pp 26-34 General Article. Listening to the Shape of a Drum - The Mathematics of Vibrating Drums · S Kesavan · More Details Fulltext PDF. Volume 3 ...
Resonances, resonance functions and spectral deformations
International Nuclear Information System (INIS)
Balslev, E.
1984-01-01
The present paper is aimed at an analysis of resonances and resonance states from a mathematical point of view. Resonances are characterized as singular points of the analytically continued Lippman-Schwinger equation, as complex eigenvalues of the Hamiltonian with a purely outgoing, exponentially growing eigenfunction, and as poles of the S-matrix. (orig./HSI)
Static electromagnetic properties of giant resonances
International Nuclear Information System (INIS)
Koo, W.K.
1986-03-01
Static electric monopole and quadrupole matrix elements, which are related to the mean square radius and quadrupole moment respectively, are derived for giant resonances of arbitrary multipolarity. The results furnish information on the size and shape of the nucleus in the excited giant states. (author)
A 2:1 MUX Based on Multiple MEMS Resonators
Hafiz, Md Abdullah Al
2017-01-09
Micro/nano-electromechanical resonator based mechanical computing has recently attracted significant attention. This paper reports a realization of a 2:1 MUX, a concatenable digital logic element, based on electrothermal frequency tuning of electrically connected multiple arch resonators. Toward this, shallow arch shaped microresonators are electrically connected and their resonance frequencies are tuned based on an electrothermal frequency modulation scheme. This study demonstrates that by reconfiguring the same basic building block, the arch microresonator, complex logic circuits can be realized.
A 2:1 MUX Based on Multiple MEMS Resonators
Hafiz, Md Abdullah Al; Kosuru, Lakshmoji; Younis, Mohammad I.; Fariborzi, Hossein
2017-01-01
Micro/nano-electromechanical resonator based mechanical computing has recently attracted significant attention. This paper reports a realization of a 2:1 MUX, a concatenable digital logic element, based on electrothermal frequency tuning of electrically connected multiple arch resonators. Toward this, shallow arch shaped microresonators are electrically connected and their resonance frequencies are tuned based on an electrothermal frequency modulation scheme. This study demonstrates that by reconfiguring the same basic building block, the arch microresonator, complex logic circuits can be realized.
Kappers, A.M.L.; Bergmann Tiest, W.M.
2014-01-01
The shape of objects cannot only be recognized by vision, but also by touch. Vision has the advantage that shapes can be seen at a distance, but touch has the advantage that during exploration many additional object properties become available, such as temperature (Jones, 2009), texture (Bensmaia,
Cady, Jo Ann; Wells, Pamela
2016-01-01
The Odd Shape Out task was an open-ended problem that engaged students in comparing shapes based on their properties. Four teachers submitted the work of 116 students from across the country. This article compares various student's responses to the task. The problem allowed for differentiation, as shown by the many different ways that students…
Discriminative Shape Alignment
DEFF Research Database (Denmark)
Loog, M.; de Bruijne, M.
2009-01-01
, not taking into account that eventually the shapes are to be assigned to two or more different classes. This work introduces a discriminative variation to well-known Procrustes alignment and demonstrates its benefit over this classical method in shape classification tasks. The focus is on two...
International Nuclear Information System (INIS)
Wellens, Thomas; Shatokhin, Vyacheslav; Buchleitner, Andreas
2004-01-01
We are taught by conventional wisdom that the transmission and detection of signals is hindered by noise. However, during the last two decades, the paradigm of stochastic resonance (SR) proved this assertion wrong: indeed, addition of the appropriate amount of noise can boost a signal and hence facilitate its detection in a noisy environment. Due to its simplicity and robustness, SR has been implemented by mother nature on almost every scale, thus attracting interdisciplinary interest from physicists, geologists, engineers, biologists and medical doctors, who nowadays use it as an instrument for their specific purposes. At the present time, there exist a lot of diversified models of SR. Taking into account the progress achieved in both theoretical understanding and practical application of this phenomenon, we put the focus of the present review not on discussing in depth technical details of different models and approaches but rather on presenting a general and clear physical picture of SR on a pedagogical level. Particular emphasis will be given to the implementation of SR in generic quantum systems-an issue that has received limited attention in earlier review papers on the topic. The major part of our presentation relies on the two-state model of SR (or on simple variants thereof), which is general enough to exhibit the main features of SR and, in fact, covers many (if not most) of the examples of SR published so far. In order to highlight the diversity of the two-state model, we shall discuss several examples from such different fields as condensed matter, nonlinear and quantum optics and biophysics. Finally, we also discuss some situations that go beyond the generic SR scenario but are still characterized by a constructive role of noise
Directory of Open Access Journals (Sweden)
Kaba Dramane
2010-10-01
Full Text Available Abstract Background Landmark based geometric morphometrics (GM allows the quantitative comparison of organismal shapes. When applied to systematics, it is able to score shape changes which often are undetectable by traditional morphological studies and even by classical morphometric approaches. It has thus become a fast and low cost candidate to identify cryptic species. Due to inherent mathematical properties, shape variables derived from one set of coordinates cannot be compared with shape variables derived from another set. Raw coordinates which produce these shape variables could be used for data exchange, however they contain measurement error. The latter may represent a significant obstacle when the objective is to distinguish very similar species. Results We show here that a single user derived dataset produces much less classification error than a multiple one. The question then becomes how to circumvent the lack of exchangeability of shape variables while preserving a single user dataset. A solution to this question could lead to the creation of a relatively fast and inexpensive systematic tool adapted for the recognition of cryptic species. Conclusions To preserve both exchangeability of shape and a single user derived dataset, our suggestion is to create a free access bank of reference images from which one can produce raw coordinates and use them for comparison with external specimens. Thus, we propose an alternative geometric descriptive system that separates 2-D data gathering and analyzes.
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
Compared with piezoelectric ceramics and magnetostrictive materials, the shape memory materials possess larger recoverable strain and recovery stress but slower response to external field. It is expected that the magneto-shape memory materials may develop considerable strain as well as rapid and precise shape control. Pseudoelasticity and shape memory effect (SME) resulted from martensitic transformation and its reverse transformation in shape memory materials were generally described. The requirements of appearing the shape memory effect in materials and the criteria for thermoelastic martensitic transformation were given. Some aspects concerning characteristics of martensitic transformation, and factors affecting SME in Ni-Ti, Cu-Zn-Al and Fe-Mn-Si based alloys as well as ZrO2 containing ceramics were briefly reviewed. Thermodynamic calculation of Ms temperature as function of grain size and parent ordering in Cu-Zn-Al was presented. The works on prediction of Ms in Fe-Mn-Si based alloys and in ZrO2-CeO2 were mentioned. Magnetic shape memory materials were briefly introduced.
Analytic Solution of the Electromagnetic Eigenvalues Problem in a Cylindrical Resonator
Energy Technology Data Exchange (ETDEWEB)
Checchin, Mattia [Fermilab; Martinello, Martina [Fermilab
2016-10-06
Resonant accelerating cavities are key components in modern particles accelerating facilities. These take advantage of electromagnetic fields resonating at microwave frequencies to accelerate charged particles. Particles gain finite energy at each passage through a cavity if in phase with the resonating field, reaching energies even of the order of $TeV$ when a cascade of accelerating resonators are present. In order to understand how a resonant accelerating cavity transfers energy to charged particles, it is important to determine how the electromagnetic modes are exited into such resonators. In this paper we present a complete analytical calculation of the resonating fields for a simple cylindrical-shaped cavity.
Magnetic resonance tomography in syringomyelia
International Nuclear Information System (INIS)
Koehler, D.; Treisch, J.; Hertel, G.; Schoerner, W.; Fiegler, W.; Staedtisches Rudolf-Virchow Krankenhaus, Berlin
1985-01-01
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. (orig.) [de
Resonance control of mid-infrared metamaterials using arrays of split-ring resonator pairs
Yue, Weisheng
2016-01-11
We present our design, fabrication and characterization of resonance-controllable metamaterials operating at mid-infrared wavelengths. The metamaterials are composed of pairs of back-to-back or face-to-face U-shape split-ring resonators (SRRs). Transmission spectra of the metamaterials are measured using Fourier-transform infrared spectroscopy. The results show that the transmission resonance is dependent on the distance between the two SRRs in each SRR pair. The dips in the transmission spectrum shift to shorter wavelengths with increasing distance between the two SRRs for both the back-to-back and face-to-face SRR pairs. The position of the resonance dips in the spectrum can hence be controlled by the relative position of the SRRs. This mechanism of resonance control offers a promising way of developing metamaterials with tunability for optical filters and bio/chemical sensing devices in integrated nano-optics.
Resonance control of mid-infrared metamaterials using arrays of split-ring resonator pairs
Yue, Weisheng; Wang, Zhihong; Whittaker, John; Schedin, Fredrik; Wu, Zhipeng; Han, Jiaguang
2016-01-01
We present our design, fabrication and characterization of resonance-controllable metamaterials operating at mid-infrared wavelengths. The metamaterials are composed of pairs of back-to-back or face-to-face U-shape split-ring resonators (SRRs). Transmission spectra of the metamaterials are measured using Fourier-transform infrared spectroscopy. The results show that the transmission resonance is dependent on the distance between the two SRRs in each SRR pair. The dips in the transmission spectrum shift to shorter wavelengths with increasing distance between the two SRRs for both the back-to-back and face-to-face SRR pairs. The position of the resonance dips in the spectrum can hence be controlled by the relative position of the SRRs. This mechanism of resonance control offers a promising way of developing metamaterials with tunability for optical filters and bio/chemical sensing devices in integrated nano-optics.
Magnetic shape memory behaviour
International Nuclear Information System (INIS)
Brown, P.J.; Gandy, A.P.; Ishida, K.; Kainuma, R.; Kanomata, T.; Matsumoto, M.; Morito, H.; Neumann, K.-U.; Oikawa, K.; Ouladdiaf, B.; Ziebeck, K.R.A.
2007-01-01
Materials that can be transformed at one temperature T F , then cooled to a lower temperature T M and plastically deformed and on heating to T F regain their original shape are currently receiving considerable attention. In recovering their shape the alloys can produce a displacement or a force, or a combination of the two. Such behaviour is known as the shape memory effect and usually takes place by change of temperature or applied stress. For many applications the transformation is not sufficiently rapid or a change in temperature/pressure not appropriate. As a result, considerable effort is being made to find a ferromagnetic system in which the effect can be controlled by an applied magnetic field. The results of recent experiments on ferromagnetic shape memory compounds aimed at understanding the underlying mechanism will be reviewed
National Research Council Canada - National Science Library
Rittenhouse, Wiley P; Kwinn, Jr, Michael J
2005-01-01
...) - to meet the future needs of the Army for commissioned officers. It is designed to shape each cohort to meet the Army's specific needs in terms of component, academic disciplines, race/ethnic makeup goals, gender, and targeted missions...
Characterization of the Bell-Shaped Vibratory Angular Rate Gyro
Directory of Open Access Journals (Sweden)
Junfang Fan
2013-08-01
Full Text Available The bell-shaped vibratory angular rate gyro (abbreviated as BVG is a novel shell vibratory gyroscope, which is inspired by the Chinese traditional bell. It sensitizes angular velocity through the standing wave precession effect. The bell-shaped resonator is a core component of the BVG and looks like the millimeter-grade Chinese traditional bell, such as QianLong Bell and Yongle Bell. It is made of Ni43CrTi, which is a constant modulus alloy. The exciting element, control element and detection element are uniformly distributed and attached to the resonator, respectively. This work presents the design, analysis and experimentation on the BVG. It is most important to analyze the vibratory character of the bell-shaped resonator. The strain equation, internal force and the resonator's equilibrium differential equation are derived in the orthogonal curvilinear coordinate system. When the input angular velocity is existent on the sensitive axis, an analysis of the vibratory character is performed using the theory of thin shells. On this basis, the mode shape function and the simplified second order normal vibration mode dynamical equation are obtained. The coriolis coupling relationship about the primary mode and secondary mode is established. The methods of the signal processing and control loop are presented. Analyzing the impact resistance property of the bell-shaped resonator, which is compared with other shell resonators using the Finite Element Method, demonstrates that BVG has the advantage of a better impact resistance property. A reasonable means of installation and a prototypal gyro are designed. The gyroscopic effect of the BVG is characterized through experiments. Experimental results show that the BVG has not only the advantages of low cost, low power, long work life, high sensitivity, and so on, but, also, of a simple structure and a better impact resistance property for low and medium angular velocity measurements.
Sroufe, Paul; Phithakkitnukoon, Santi; Dantu, Ram; Cangussu, João
2010-01-01
Email has become an integral part of everyday life. Without a second thought we receive bills, bank statements, and sales promotions all to our inbox. Each email has hidden features that can be extracted. In this paper, we present a new mechanism to characterize an email without using content or context called Email Shape Analysis. We explore the applications of the email shape by carrying out a case study; botnet detection and two possible applications: spam filtering, and social-context bas...
STEREOLOGICAL ANALYSIS OF SHAPE
Directory of Open Access Journals (Sweden)
Asger Hobolth
2011-05-01
Full Text Available This paper concerns the problem of making stereological inference about the shape variability in a population of spatial particles. Under rotational invariance the shape variability can be estimated from central planar sections through the particles. A simple, but flexible, parametric model for rotation invariant spatial particles is suggested. It is shown how the parameters of the model can be estimated from observations on central sections. The corresponding model for planar particles is also discussed in some detail.
International Nuclear Information System (INIS)
Sushilov, N.V.; Kholodkevich, E.D.
1995-01-01
An analytical expression is derived for the polarization induced by a weak probe field with periodically modulated amplitude in a two-level medium saturated by a strong amplitude-and phase-modulated resonance field. It is shown that the absorption spectrum of the probe field includes parametric resonances, the maxima corresponding to the condition δ= 2nΓ-Ω w and the minima to that of δ= (2n + 1)Γ- w , where δ is the probe-field detuning front the resonance frequency, Ω w is the modulation frequency of the probe-field amplitude, and Γ is the transition line width, n = 1, 2, 3, hor-ellipsis. At the specific modulation parameters, a substantial region of negative values (i.e., the region of amplification without the population inversion) exists in the absorption spectrum of the probe field
Universality of fragment shapes.
Domokos, Gábor; Kun, Ferenc; Sipos, András Árpád; Szabó, Tímea
2015-03-16
The shape of fragments generated by the breakup of solids is central to a wide variety of problems ranging from the geomorphic evolution of boulders to the accumulation of space debris orbiting Earth. Although the statistics of the mass of fragments has been found to show a universal scaling behavior, the comprehensive characterization of fragment shapes still remained a fundamental challenge. We performed a thorough experimental study of the problem fragmenting various types of materials by slowly proceeding weathering and by rapid breakup due to explosion and hammering. We demonstrate that the shape of fragments obeys an astonishing universality having the same generic evolution with the fragment size irrespective of materials details and loading conditions. There exists a cutoff size below which fragments have an isotropic shape, however, as the size increases an exponential convergence is obtained to a unique elongated form. We show that a discrete stochastic model of fragmentation reproduces both the size and shape of fragments tuning only a single parameter which strengthens the general validity of the scaling laws. The dependence of the probability of the crack plan orientation on the linear extension of fragments proved to be essential for the shape selection mechanism.
Non-conventional ordering studied by magnetic resonance in Fe-doped manganites
International Nuclear Information System (INIS)
Gutierrez, J.; Siruguri, V.; Barandiaran, J.M.; Pena, A.; Lezama, L.; Rojo, T.
2006-01-01
Coexistence of ferromagnetic (FM) and paramagnetic (PM) phases in La 0.7 Pb 0.3 (Mn 1-x Fe x )O 3 (0.1=< x=<0.3) manganites is studied by the electron spin resonance (ESR) technique. Doping with Fe gives rise to a progressive decrease both in the low-temperature magnetic moment and magnetic order temperature values. Obtained spectra show narrow resonance signals above Curie temperature that transform to asymmetric Dyson-like signals as temperature decreases. The evolution of line width with temperature shows minima that correlate directly with the obtained paramagnetic Curie temperatures. Analysis of spectra above and below magnetic order temperatures reveals features of complex PM to FM transitions and coexistence of both type of phases in a wide range of temperatures
Shapes of interacting RNA complexes
DEFF Research Database (Denmark)
Fu, Benjamin Mingming; Reidys, Christian
2014-01-01
Shapes of interacting RNA complexes are studied using a filtration via their topological genus. A shape of an RNA complex is obtained by (iteratively) collapsing stacks and eliminating hairpin loops.This shape-projection preserves the topological core of the RNA complex and for fixed topological...... genus there are only finitely many such shapes. Our main result is a new bijection that relates the shapes of RNA complexes with shapes of RNA structures. This allows to compute the shape polynomial of RNA complexes via the shape polynomial of RNA structures. We furthermore present a linear time uniform...... sampling algorithm for shapes of RNA complexes of fixed topological genus....
2011-10-01
11:15 – 11:45 Invited Talk – Stars in Magnetic Grand Minima: Where Are They and What Are They Like? Steven Saar (Presentation file) 11:45 – 12:00...of Archaeology and Ancient History, University Rd, Leicester LE1 7RH, United Kingdom IAUS 279 Death of Massive Stars: Supernovae and Gamma-Ray Bursts...of Astronomy & Astrophysics, 525 Davey Lab, University Park, PA 16802, USA IAUS 283 Planetary Nebulae: an Eye to the Future A. MANCHADO, Instituto de
Shapes and dynamics from the time-dependent mean field
International Nuclear Information System (INIS)
Stevenson, P.D.; Goddard, P.M.; Rios, A.
2015-01-01
Explaining observed properties in terms of underlying shape degrees of freedom is a well-established prism with which to understand atomic nuclei. Self-consistent mean-field models provide one tool to understand nuclear shapes, and their link to other nuclear properties and observables. We present examples of how the time-dependent extension of the mean-field approach can be used in particular to shed light on nuclear shape properties, particularly looking at the giant resonances built on deformed nuclear ground states, and at dynamics in highly-deformed fission isomers. Example calculations are shown of 28 Si in the first case, and 240 Pu in the latter case
Transverse electron resonance accelerator
International Nuclear Information System (INIS)
Osonka, P.L.
1985-01-01
Transverse (to the velocity, v-bar, of the particles to be accelerated) electron oscillations are generated in high (e.g. solid) density plasms by either an electromagnetic wave or by the field of charged particles traveling parallel to v-bar. The generating field oscillates with frequency ω = ω/sub p/, where ω/sub p/ is the plasma frequency. The plasma is confined to a sequence of microstructures with typical dimensions of d≅2πc/ω/sub p/, allowing the generating fields to penetrate. Since ω/sub p/ is now high, the time scales, T, are correspondingly reduced. The microstructures are allowed to explode after t = T, until then they are confined by ion inertia. As a result of resonance, the electric field, E, inside the microstructures can exceed the generating field E/sub L/. The generating force is proportional to E/sub L/ (as opposed to E 2 /sub L/). Phase matching of particles is possible by appropriate spacing of the microstructures or by a gas medium. The generating beam travels outside the plasma, filamentation is not a problem. The mechanism is relatively insensitive to the exact shape and position of the microstructures. This device contains features of various earlier proposed acceleration mechanisms and may be considered as the limiting case of several of those for small d, T and high E
Transverse electron resonance accelerator
International Nuclear Information System (INIS)
Csonka, P.L.
1985-01-01
Transverse (to the velocity, v, of the particles to be accelerated) electron oscillations are generated in high (e.g. solid) density plasmas by either an electromagnetic wave or by the field of charged particles traveling parallel to v. The generating field oscillates with frequency ω = ω/sub p/, where ω/sub p/ is the plasma frequency. The plasma is confined to a sequence of microstructures with typical dimensions of d approx. = 2πc/ω/sub p/, allowing the generating fields to penetrate. Since ω/sub p/ is now high, the time scales, T, are correspondingly reduced. The microstructures are allowed to explode after t = T, until then they are confined by ion inertia. As a result of resonance, the electric field, E, inside the microstructures can exceed the generating field E/sub L/. The generating force is proportional to E/sub L/ (as opposed to E/sub L/ 2 ). Phase matching of particles is possible by appropriate spacing of the microstructures or by a gas medium. The generating beam travels outside the plasma, filamentation is not a problem. The mechanism is relatively insensitive to the exact shape and position of the microstructures. This device contains features of various earlier proposed acceleration mechanisms and may be considered as the limiting case of several of those for small d, T and high E
The osseous external auditory canal : Surgery, shape, and sound
van Spronsen, E.
2018-01-01
This thesis describes three aspects of the osseous external auditory canal (OEAC) which are related to each other: Surgery of the OEAC, the shape of the OEAC and the perceived sound quality due to the resonance function of the OEAC. Several aspects of the surgical intervention (Canalplasty) in
False Memories for Shape Activate the Lateral Occipital Complex
Karanian, Jessica M.; Slotnick, Scott D.
2017-01-01
Previous functional magnetic resonance imaging evidence has shown that false memories arise from higher-level conscious processing regions rather than lower-level sensory processing regions. In the present study, we assessed whether the lateral occipital complex (LOC)--a lower-level conscious shape processing region--was associated with false…
SHAPE selection (SHAPES) enrich for RNA structure signal in SHAPE sequencing-based probing data
DEFF Research Database (Denmark)
Poulsen, Line Dahl; Kielpinski, Lukasz Jan; Salama, Sofie R
2015-01-01
transcriptase. Here, we introduce a SHAPE Selection (SHAPES) reagent, N-propanone isatoic anhydride (NPIA), which retains the ability of SHAPE reagents to accurately probe RNA structure, but also allows covalent coupling between the SHAPES reagent and a biotin molecule. We demonstrate that SHAPES...
Vogt, Dominik Walter; Leonhardt, Rainer
2017-11-01
We report on Fano resonances in a high-quality (Q) whispering-gallery mode (WGM) spherical resonator coupled to a multi-mode waveguide in the terahertz (THz) frequency range. The asymmetric line shape and phase of the Fano resonances detected with coherent continuous-wave (CW) THz spectroscopy measurements are in excellent agreement with the analytical model. A very high Q factor of 1600, and a finesse of 22 at critical coupling is observed around 0.35 THz. To the best of our knowledge this is the highest Q factor ever reported for a THz WGM resonator.
Shape memory polymer medical device
Maitland, Duncan [Pleasant Hill, CA; Benett, William J [Livermore, CA; Bearinger, Jane P [Livermore, CA; Wilson, Thomas S [San Leandro, CA; Small, IV, Ward; Schumann, Daniel L [Concord, CA; Jensen, Wayne A [Livermore, CA; Ortega, Jason M [Pacifica, CA; Marion, III, John E.; Loge, Jeffrey M [Stockton, CA
2010-06-29
A system for removing matter from a conduit. The system includes the steps of passing a transport vehicle and a shape memory polymer material through the conduit, transmitting energy to the shape memory polymer material for moving the shape memory polymer material from a first shape to a second and different shape, and withdrawing the transport vehicle and the shape memory polymer material through the conduit carrying the matter.
International Nuclear Information System (INIS)
Sutcliffe, P.W.; Isaacs, J.W.; Lyon, C.E.
1979-01-01
A method for the preparation of a shaped body includes pressing a powder to give a 'green' shaped body, the powder having been made by comminuting a material prepared by means of a gelation process, the material prior to comminuting being of a selected physical configuration (e.g. spherical). Thus, a material prepared by means of a gelation process can be transported and handled in an environmentally desirable, substantially dust-free form (e.g. spherical particles) and then comminuted to produce a powder for pressing into e.g. a shaped nuclear fuel body (e.g. pellets of (70%U/30%Pu)O 2 ), which can be sintered. (author)
Microelectromechanical resonator based digital logic elements
Hafiz, Md Abdullah Al
2016-10-20
Micro/nano-electromechanical resonator based mechanical computing has recently attracted significant attention. However, its full realization has been hindered by the difficulty in realizing complex combinational logics, in which the logic function is constructed by cascading multiple smaller logic blocks. In this work we report an alternative approach for implementation of digital logic core elements, multiplexer and demultiplexer, which can be used to realize combinational logic circuits by suitable concatenation. Toward this, shallow arch shaped microresonators are electrically connected and their resonance frequencies are tuned based on an electrothermal frequency modulation scheme. This study demonstrates that by reconfiguring the same basic building block, the arch microresonator, complex logic circuits can be realized.
Microelectromechanical resonator based digital logic elements
Hafiz, Md Abdullah Al; Kosuru, Lakshmoji; Younis, Mohammad I.; Fariborzi, Hossein
2016-01-01
Micro/nano-electromechanical resonator based mechanical computing has recently attracted significant attention. However, its full realization has been hindered by the difficulty in realizing complex combinational logics, in which the logic function is constructed by cascading multiple smaller logic blocks. In this work we report an alternative approach for implementation of digital logic core elements, multiplexer and demultiplexer, which can be used to realize combinational logic circuits by suitable concatenation. Toward this, shallow arch shaped microresonators are electrically connected and their resonance frequencies are tuned based on an electrothermal frequency modulation scheme. This study demonstrates that by reconfiguring the same basic building block, the arch microresonator, complex logic circuits can be realized.
A multilevel shape fit analysis of neutron transmission data
International Nuclear Information System (INIS)
Naguib, K.; Sallam, O.H.; Adib, M.
1989-01-01
A multilevel shape fit analysis of neutron transmission data is presented. A multilevel computer code SHAPE is used to analyse clean transmission data obtained from time-of-flight (TOF) measurements. The shape analysis deduces the parameters of the observed resonances in the energy region considered in the measurements. The shape code is based upon a least square fit of a multilevel Breit-Wigner formula and includes both instrumental resolution and Doppler broadenings. Operating the SHAPE code on a test example of a measured transmission data of 151 Eu, 153 Eu and natural Eu in the energy range 0.025-1 eV acquired a good result for the used technique of analysis. (author)
DEFF Research Database (Denmark)
Buur, Jacob; Mack, Alexandra
- in particular in a large corporation? This workshop explores how innovation is socially shaped in organizations. Based on our experiences with practices around innovation and collaboration, we start from three proposition about the social shaping of innovation: • Ideas don't thrive as text (i.e. we need...... to consider other media) • Ideas need socialization (ideas are linked to people, we need to be careful about how we support the social innovation context) • Ideas are local (ideas spring out of a local contingency, we need to take care in how we like them to travel)....
Directory of Open Access Journals (Sweden)
Oswin Aichholzer
2014-05-01
Full Text Available Can folding a piece of paper flat make it larger? We explore whether a shape S must be scaled to cover a flat-folded copy of itself. We consider both single folds and arbitrary folds (continuous piecewise isometries \\(S\\to\\mathbb{R}^2\\. The underlying problem is motivated by computational origami, and is related to other covering and fixturing problems, such as Lebesgue's universal cover problem and force closure grasps. In addition to considering special shapes (squares, equilateral triangles, polygons and disks, we give upper and lower bounds on scale factors for single folds of convex objects and arbitrary folds of simply connected objects.
International Nuclear Information System (INIS)
Koshimizu, S.
1992-01-01
Although the pseudo- or super-elasticity phenomena and the shape memory effect were known since the 1940's, the enormous curiosity and the great interest to their practical applications emerged with the development of the NITINOL alloy (Nickel-Titanium Naval Ordance Laboratory) by the NASA during the 1960's. This fact marked the appearance of a new class of materials, popularly known as shape memory effect alloys (SMEA). The objective of this work is to present a state-of-the-art of the development and applications for the SMEA. (E.O.)
Neutron cross sections in the unresolved resonance region
International Nuclear Information System (INIS)
Janeva, N.; Lukyanov, A.; Koyumdjieva, N.; Volev, K.
2005-01-01
In this work a development of the characteristic function model, created to reveal the resonance cross section structure in the unresolved resonance region is presented. The main advantage of this model is the calculation of resonance averaged self-shielding factors analytically. To determine average values of the cross sections and their functionals the function of joint statistical distribution of the R-matrix real and imaginary parts should be used. The characteristic function of such distribution is determined and the resonance ladder for the unresolved region is optimized to calculate the group averaged functionals in the same way as it is in the resolved resonance region. The main advantage of this model is the calculation of resonance averaged self-shielding factors analytically. The neutron width energy dependence leads to some deformation in the shape of resonances. This deformation is most apparent near the inelastic scattering threshold. For the case when the inelastic channel momentum is zero we present the formula for level shape bellow and over the inelastic threshold and the calculated resonance deformation in dependence of the position of the resonance in respect to the threshold. (authors)
Determination of giant resonance strengths
International Nuclear Information System (INIS)
Serr, F.E.
1983-01-01
Using theoretical strength functions to describe the different giant resonances expected at excitation energies of the order of (60-85)/Asup(1/3) MeV, we calculate the double differential cross sections d 2 sigma/dΩ dE associated with the reactions 208 Pb(α, α') and 90 Zr(α, α') (Esub(α) = 152 MeV). The angular distributions for the giant quadrupole and giant monopole resonances obtained from fits to these spectra, making simple, commonly used assumptions for the peak shapes and background, are compared to the original angular distributions. The differences between them are an indication of some of the uncertainties affecting the giant resonance strengths extracted from hadron inelastic scattering data. Fits to limited angular regions lead to errors of up to 50% in the value of the energy-weighted sum rule, depending on the angles examined. While it seems possible to extract the correct EWSR for the GMR by carrying out the analyses at 0 0 , no single privileged angle seems to exist in the case of the GQR. (orig.)
International Nuclear Information System (INIS)
Collins, T.
1985-08-01
A simple criterion governs the beam distortion and/or loss of protons on a fast resonance crossing. Results from numerical integrations are illustrated for simple sextupole, octupole, and 10-pole resonances
International Nuclear Information System (INIS)
Chrien, R.E.
1986-10-01
The principles of resonance averaging as applied to neutron capture reactions are described. Several illustrations of resonance averaging to problems of nuclear structure and the distribution of radiative strength in nuclei are provided. 30 refs., 12 figs
Energy Technology Data Exchange (ETDEWEB)
Collins, T.
1985-08-01
A simple criterion governs the beam distortion and/or loss of protons on a fast resonance crossing. Results from numerical integrations are illustrated for simple sextupole, octupole, and 10-pole resonances.
DEFF Research Database (Denmark)
Stenholt, Rasmus; Madsen, Claus B.
2011-01-01
Enabling users to shape 3-D boxes in immersive virtual environments is a non-trivial problem. In this paper, a new family of techniques for creating rectangular boxes of arbitrary position, orientation, and size is presented and evaluated. These new techniques are based solely on position data...
Martínez, Sol Sáez; de la Rosa, Félix Martínez; Rojas, Sergio
2017-01-01
In Advanced Calculus, our students wonder if it is possible to graphically represent a tornado by means of a three-dimensional curve. In this paper, we show it is possible by providing the parametric equations of such tornado-shaped curves.
Sounds Exaggerate Visual Shape
Sweeny, Timothy D.; Guzman-Martinez, Emmanuel; Ortega, Laura; Grabowecky, Marcia; Suzuki, Satoru
2012-01-01
While perceiving speech, people see mouth shapes that are systematically associated with sounds. In particular, a vertically stretched mouth produces a /woo/ sound, whereas a horizontally stretched mouth produces a /wee/ sound. We demonstrate that hearing these speech sounds alters how we see aspect ratio, a basic visual feature that contributes…
Aerodynamically shaped vortex generators
DEFF Research Database (Denmark)
Hansen, Martin Otto Laver; Velte, Clara Marika; Øye, Stig
2016-01-01
An aerodynamically shaped vortex generator has been proposed, manufactured and tested in a wind tunnel. The effect on the overall performance when applied on a thick airfoil is an increased lift to drag ratio compared with standard vortex generators. Copyright © 2015 John Wiley & Sons, Ltd....
2002-01-01
A Japanese team has found a way to bend and shape silicon substrates by growing a thin layer of diamond on top. The technique has been proposed as an alternative to mechanical bending, which is currently used to make reflective lenses for X-ray systems and particle physics systems (2 paragraphs).
Pesyna, Colin; Pundi, Krishna; Flanders, Martha
2011-03-09
The neural control of hand movement involves coordination of the sensory, motor, and memory systems. Recent studies have documented the motor coordinates for hand shape, but less is known about the corresponding patterns of somatosensory activity. To initiate this line of investigation, the present study characterized the sense of hand shape by evaluating the influence of differences in the amount of grasping or twisting force, and differences in forearm orientation. Human subjects were asked to use the left hand to report the perceived shape of the right hand. In the first experiment, six commonly grasped items were arranged on the table in front of the subject: bottle, doorknob, egg, notebook, carton, and pan. With eyes closed, subjects used the right hand to lightly touch, forcefully support, or imagine holding each object, while 15 joint angles were measured in each hand with a pair of wired gloves. The forces introduced by supporting or twisting did not influence the perceptual report of hand shape, but for most objects, the report was distorted in a consistent manner by differences in forearm orientation. Subjects appeared to adjust the intrinsic joint angles of the left hand, as well as the left wrist posture, so as to maintain the imagined object in its proper spatial orientation. In a second experiment, this result was largely replicated with unfamiliar objects. Thus, somatosensory and motor information appear to be coordinated in an object-based, spatial-coordinate system, sensitive to orientation relative to gravitational forces, but invariant to grasp forcefulness.
Gross, Michael
2015-10-05
Earth is much more complex than all the other solar system objects that we know. Thanks to its rich and diverse geology, our planet can offer habitats to a wide range of living species. Emerging insights suggest that this is not just a happy coincidence, but that life itself has in many ways helped to shape the planet.
Interactive shape metamorphosis
Chen, David T.; State, Andrei; Banks, David
1994-01-01
A technique for controlled metamorphosis between surfaces in 3-space is described. Well-understood techniques to produce shape metamorphosis between models in a 2D parametric space is applied. The user selects morphable features interactively, and the morphing process executes in real time on a high-performance graphics multicomputer.
Pediatric magnetic resonance imaging
International Nuclear Information System (INIS)
Cohen, M.D.
1986-01-01
This book defines the current clinical potential of magnetic resonance imaging and focuses on direct clinical work with pediatric patients. A section dealing with the physics of magnetic resonance imaging provides an introduction to enable clinicians to utilize the machine and interpret the images. Magnetic resonance imaging is presented as an appropriate imaging modality for pediatric patients utilizing no radiation
Resonant thermonuclear reaction rate
International Nuclear Information System (INIS)
Haubold, H.J.; Mathai, A.M.
1986-01-01
Basic physical principles for the resonant and nonresonant thermonuclear reaction rates are applied to find their standard representations for nuclear astrophysics. Closed-form representations for the resonant reaction rate are derived in terms of Meijer's G-function. Analytic representations of the resonant and nonresonant nuclear reaction rates are compared and the appearance of Meijer's G-function is discussed in physical terms
Electrothermally actuated tunable clamped-guided resonant microbeams
Alcheikh, Nouha
2017-06-11
We present simulation and experimental investigation demonstrating active alteration of the resonant and frequency response behavior of resonators by controlling the electrothermal actuation method on their anchors. In-plane clamped-guided arch and straight microbeams resonators are designed and fabricated with V-shaped electrothermal actuators on their anchors. These anchors not only offer various electrothermal actuation options, but also serve as various mechanical stiffness elements that affect the operating resonance frequency of the structures. We have shown that for an arch, the first mode resonance frequency can be increased up to 50% of its initial value. For a straight beam, we have shown that before buckling, the resonance frequency decreases to very low values and after buckling, it increases up to twice of its initial value. These results can be promising for the realization of different wide–range tunable microresonator. The experimental results have been compared to multi-physics finite-element simulations showing good agreement among them.
Electrothermally actuated tunable clamped-guided resonant microbeams
Alcheikh, N.; Hajjaj, A. Z.; Jaber, N.; Younis, M. I.
2018-01-01
We present simulation and experimental investigation demonstrating active alteration of the resonant and frequency response behavior of resonators by controlling the electrothermal actuation method on their anchors. In-plane clamped-guided arch and straight microbeams resonators are designed and fabricated with V-shaped electrothermal actuators on their anchors. These anchors not only offer various electrothermal actuation options, but also serve as various mechanical stiffness elements that affect the operating resonance frequency of the structures. We have shown that for an arch, the first mode resonance frequency can be increased up to 50% of its initial value. For a straight beam, we have shown that before buckling, the resonance frequency decreases to very low values and after buckling, it increases up to twice of its initial value. These results can be promising for the realization of different wide-range tunable microresonator. The experimental results have been compared to multi-physics finite-element simulations showing good agreement among them.
International Nuclear Information System (INIS)
Cisneros S, A.; McIntosh, H.V.
1982-01-01
A discussion of the nature of quantum mechanical resonances is presented from the point of view of the spectral theory of operators. In the case of Bohr-Feshbach resonances, graphs are presented to illustrate the theory showing the decay of a doubly excited metastable state and the excitation of the resonance by an incident particle with proper energy. A characterization of resonances is given as well as a procedure to determine widths using the spectral density function. A sufficient condition is given for the validity of the Breit-Wigner formula for Bohr-Feshbach resonances. (author)
Spectral Line Shapes. Proceedings
International Nuclear Information System (INIS)
Zoppi, M.; Ulivi, L.
1997-01-01
These proceedings represent papers presented at the 13th International Conference on Spectral Line Shapes which was held in Firenze,Italy from June 16-21, 1996. The topics covered a wide range of subjects emphasizing the physical processes associated with the formation of line profiles: high and low density plasma; atoms and molecules in strong laser fields, Dopple-free and ultra-fine spectroscopy; the line shapes generated by the interaction of neutrals, atoms and molecules, where the relavant quantities are single particle properties, and the interaction-induced spectroscopy. There were 131 papers presented at the conference, out of these, 6 have been abstracted for the Energy Science and Technology database
Surface Plasmon Resonance Biosensor
Directory of Open Access Journals (Sweden)
Nina GRIDINA
2013-02-01
Full Text Available Performed in this paper is numerical modeling of the angular dependence for light reflectivity R(F in surface plasmon-polariton resonance (SPR realized in Kretschmann geometry when studying the interface gold/suspension of spherical particles (cells in the assumption that the dielectric permittivity of particles suspension is described by the theory of effective medium. It has been shown that availability of suspended particles in solution inevitably results in appearance of an intermediate layer with the ε gradient between gold surface and suspension bulk, as a result of which the SPR angle shifts to lower values. Near the critical angle, the first derivative dR/dF demonstrates a clearly pronounced peak, which allows determining the value for suspension bulk and the gradient in the intermediate layer. Obtained in our experiments were SPR curves for two suspensions of erythrocytes – the dense one (erythrocyte mass after centrifuging and loose solution (whole blood. In the case of erythrocyte mass, fitting the experimental and calculated curves enabled us to quantitatively determine the bulk value for this erythrocyte mass (εb =1.96, thickness of the intermediate layer dm (300…400 nm and gradient in the intermediate layer. On the contrary, the SPR curve for whole blood appeared to be close to that of pure plasma. This fact allows only estimation of the thickness dm~2000...3000 nm as well as minimum ε value in the intermediate layer, which is close to that of plasma (ε = 1.79. Also, discussed is the mechanism of influence of the cell shape near the gold surface on the SPR effect.
International Nuclear Information System (INIS)
Zitniak, J.; Pargac, M.
2005-01-01
In the Slovak Environmental Agency during relative short time originated the first version of software product using of GPS technology for monitoring of negative phenomena in nature. It was denominated as readShape and its primary goal is to minister for conservator of environment geographically strictly to observe endangered territories as are, for example, fire, fish kill, impact of motor vehicle accident or dangerous objects as are illegal stock-piles, wastes and other. Process of monitoring is described
Varma, Venugopal K.
2001-01-01
An actuator for cycling between first and second positions includes a first shaped memory alloy (SMA) leg, a second SMA leg. At least one heating/cooling device is thermally connected to at least one of the legs, each heating/cooling device capable of simultaneously heating one leg while cooling the other leg. The heating/cooling devices can include thermoelectric and/or thermoionic elements.
Bulbous Bow Shape Optimization
Blanchard , Louis; Berrini , Elisa; Duvigneau , Régis; Roux , Yann; Mourrain , Bernard; Jean , Eric
2013-01-01
International audience; The aim of this study is to prove the usefulness of a bulbous bow for a fishing vessel, in terms of drag reduction, using an automated shape optimization procedure including hydrodynamic simulations. A bulbous bow is an appendage that is known to reduce the drag, thanks to its influence on the bow wave system. However, the definition of the geometrical parameters of the bulb, such as its length and thickness, is not intuitive, as both parameters are coupled with regard...
Memory for shape reactivates the lateral occipital complex.
Karanian, Jessica M; Slotnick, Scott D
2015-04-07
Memory is thought to be a constructive process in which the cortical regions associated with processing event features are reactivated during retrieval. Although there is evidence for non-detailed cortical reactivation during retrieval (e.g., memory for visual or auditory information reactivates the visual or auditory processing regions, respectively), there is limited evidence that memory can reactivate cortical regions associated with processing detailed, feature-specific information. Such evidence is critical to our understanding of the mechanisms of episodic retrieval. The present functional magnetic resonance imaging (fMRI) study assessed whether the lateral occipital complex (LOC), a region that preferentially processes shape, is associated with retrieval of shape information. During encoding, participants were presented with colored abstract shapes that were either intact or scrambled. During retrieval, colored disks were presented and participants indicated whether the corresponding shape was previously "intact" or "scrambled". To assess whether conscious retrieval of intact shapes reactivated LOC, we conducted a conjunction of shape perception/encoding and accurate versus inaccurate retrieval of intact shapes, which produced many activations in LOC. To determine whether activity in LOC was specific to intact shapes, we conducted a conjunction of shape perception/encoding and intact versus scrambled shapes, which also produced many activations in LOC. Furthermore, memory for intact shapes in each hemifield produced contralateral activity in LOC (e.g., memory for left visual field intact shapes activated right LOC), which reflects the specific reinstatement of perception/encoding activity. The present results extend previous feature-specific memory reactivation evidence and support the view that memory is a constructive process. Copyright © 2015 Elsevier B.V. All rights reserved.
Resonances for Obstacles in Hyperbolic Space
Hintz, Peter; Zworski, Maciej
2017-12-01
We consider scattering by star-shaped obstacles in hyperbolic space and show that resonances satisfy a universal bound { Im λ ≤ - 1/2 } , which is optimal in dimension 2. In odd dimensions we also show that { Im λ ≤ - μ/ρ } for a universal constant {μ} , where { ρ } is the radius of a ball containing the obstacle; this gives an improvement for small obstacles. In dimensions 3 and higher the proofs follow the classical vector field approach of Morawetz, while in dimension 2 we obtain our bound by working with spaces coming from general relativity. We also show that in odd dimensions resonances of small obstacles are close, in a suitable sense, to Euclidean resonances.
Audiometric shape and presbycusis.
Demeester, Kelly; van Wieringen, Astrid; Hendrickx, Jan-jaap; Topsakal, Vedat; Fransen, Erik; van Laer, Lut; Van Camp, Guy; Van de Heyning, Paul
2009-04-01
The aim of this study was to describe the prevalence of specific audiogram configurations in a healthy, otologically screened population between 55 and 65 years old. The audiograms of 1147 subjects (549 males and 598 females between 55 and 65 years old) were collected through population registries and classified according to the configuration of hearing loss. Gender and noise/solvent-exposure effects on the prevalence of the different audiogram shapes were determined statistically. In our population 'Flat' audiograms were most dominantly represented (37%) followed by 'High frequency Gently sloping' audiograms (35%) and 'High frequency Steeply sloping' audiograms (27%). 'Low frequency Ascending' audiograms, 'Mid frequency U-shape' audiograms and 'Mid frequency Reverse U-shape' audiograms were very rare (together less than 1%). The 'Flat'-configuration was significantly more common in females, whereas the 'High frequency Steeply sloping'-configuration was more common in males. Exposure to noise and/or solvents did not change this finding. In addition, females with a 'Flat' audiogram had a significantly larger amount of overall hearing loss compared to males. Furthermore, our data reveal a significant association between the prevalence of 'High frequency Steeply sloping' audiograms and the degree of noise/solvent exposure, despite a relatively high proportion of non-exposed subjects showing a 'High frequency Steeply sloping' audiogram as well.
Microstrip resonators for electron paramagnetic resonance experiments
Torrezan, A. C.; Mayer Alegre, T. P.; Medeiros-Ribeiro, G.
2009-07-01
In this article we evaluate the performance of an electron paramagnetic resonance (EPR) setup using a microstrip resonator (MR). The design and characterization of the resonator are described and parameters of importance to EPR and spin manipulation are examined, including cavity quality factor, filling factor, and microwave magnetic field in the sample region. Simulated microwave electric and magnetic field distributions in the resonator are also presented and compared with qualitative measurements of the field distribution obtained by a perturbation technique. Based on EPR experiments carried out with a standard marker at room temperature and a MR resonating at 8.17 GHz, the minimum detectable number of spins was found to be 5×1010 spins/GHz1/2 despite the low MR unloaded quality factor Q0=60. The functionality of the EPR setup was further evaluated at low temperature, where the spin resonance of Cr dopants present in a GaAs wafer was detected at 2.3 K. The design and characterization of a more versatile MR targeting an improved EPR sensitivity and featuring an integrated biasing circuit for the study of samples that require an electrical contact are also discussed.
Microstrip resonators for electron paramagnetic resonance experiments.
Torrezan, A C; Mayer Alegre, T P; Medeiros-Ribeiro, G
2009-07-01
In this article we evaluate the performance of an electron paramagnetic resonance (EPR) setup using a microstrip resonator (MR). The design and characterization of the resonator are described and parameters of importance to EPR and spin manipulation are examined, including cavity quality factor, filling factor, and microwave magnetic field in the sample region. Simulated microwave electric and magnetic field distributions in the resonator are also presented and compared with qualitative measurements of the field distribution obtained by a perturbation technique. Based on EPR experiments carried out with a standard marker at room temperature and a MR resonating at 8.17 GHz, the minimum detectable number of spins was found to be 5 x 10(10) spins/GHz(1/2) despite the low MR unloaded quality factor Q0=60. The functionality of the EPR setup was further evaluated at low temperature, where the spin resonance of Cr dopants present in a GaAs wafer was detected at 2.3 K. The design and characterization of a more versatile MR targeting an improved EPR sensitivity and featuring an integrated biasing circuit for the study of samples that require an electrical contact are also discussed.
Mode Coupling and Nonlinear Resonances of MEMS Arch Resonators for Bandpass Filters
Hajjaj, Amal Z.
2017-01-30
We experimentally demonstrate an exploitation of the nonlinear softening, hardening, and veering phenomena (near crossing), where the frequencies of two vibration modes get close to each other, to realize a bandpass filter of sharp roll off from the passband to the stopband. The concept is demonstrated based on an electrothermally tuned and electrostatically driven MEMS arch resonator operated in air. The in-plane resonator is fabricated from a silicon-on-insulator wafer with a deliberate curvature to form an arch shape. A DC current is applied through the resonator to induce heat and modulate its stiffness, and hence its resonance frequencies. We show that the first resonance frequency increases up to twice of the initial value while the third resonance frequency decreases until getting very close to the first resonance frequency. This leads to the phenomenon of veering, where both modes get coupled and exchange energy. We demonstrate that by driving both modes nonlinearly and electrostatically near the veering regime, such that the first and third modes exhibit softening and hardening behavior, respectively, sharp roll off from the passband to the stopband is achievable. We show a flat, wide, and tunable bandwidth and center frequency by controlling the electrothermal actuation voltage.
Doubly excited P-wave resonance states of H− in Debye plasmas
International Nuclear Information System (INIS)
Jiao, L. G.; Ho, Y. K.
2013-01-01
We investigate the doubly excited P-wave resonance states of H − system in Debye plasmas modeled by static screened Coulomb potentials. The screening effects of the plasma environment on resonance parameters (energy and width) are investigated by employing the complex-scaling method with Hylleraas-type wave functions for both the shape and Feshbach resonances associated with the H(N = 2 to 6) thresholds. Under the screening conditions, the H(N) threshold states are no longer l degenerate, and all the H − resonance energy levels are shifted away from their unscreened values toward the continuum. The influence of Debye plasmas on resonance widths has also been investigated. The shape resonance widths are broadened with increasing plasma screening strength, whereas the Feshbach resonance widths would generally decrease. Our results associated with the H(N = 2) and H(N = 3) thresholds are compared with others in the literature
Optical characterization of Jerusalem cross-shaped nanoaperture antenna arrays
Turkmen, Mustafa; Aslan, Ekin; Aslan, Erdem
2014-03-01
Recent advances in nanofabrication and computational electromagnetic design techniques have enabled the realization of metallic nanostructures in different shapes and sizes with adjustable resonance frequencies. To date, many metamaterial designs in various geometries with the used of different materials have been presented for the applications of surface plasmons, cloaking, biosensing, and frequency selective surfaces1-5. Surface plasmons which are collective electron oscillations on metal surfaces ensure that plasmonic nanoantennas can be used in many applications like biosensing at infrared (IR) and visible regions. The nanostructure that we introduce has a unit cell that consists of Jerusalem crossshaped nanoaperture on a gold layer, which is standing on suspended SiNx, Si or glass membranes. The proposed nanoaperture antenna array has a regular and stable spectral response. In this study, we present sensitivity of the resonance characteristics of Jerusalem cross-shaped nanoaperture antenna arrays to the changes in substrate parameters and metal thickness. We demonstrate that resonance frequency values can be adjusted by changing the thicknesses and types of the dielectric substrate and the metallic layer. Numerical calculations on spectral response of the nanoantenna array are performed by using Finite Difference Time Domain (FDTD) method6. The results of the simulations specify that resonance frequencies, the reflectance and transmittance values at resonances, and the band gap vary by the change of substrate parameters and metal thicknesses. These variations is a sign of that the proposed nanoantenna can be employed for sensing applications.
Energy Technology Data Exchange (ETDEWEB)
Ahmad, I.; Davids, C.; Janssens, R.V.F. [and others
1995-08-01
The interaction between coexisting shapes in nuclei near closed shells was of great interest in the past decade. Excited 0{sup +} states at low energy can often be identified as the bandheads of structures with differing shapes built on those states, These structures were identified in {sup 190-198}Pb via beta decay and alpha decay {open_quotes}fine structure{close_quotes} studies. Coexistence of different shapes in Pb nuclei was predicted by Nilsson-Strutinsky calculations, in which both the oblate and prolate minima were predicted to have excitation energies near 1 MeV. It was our intention to continue the systematic study of the Pb nuclides by searching for excited O{sup +} states in {sup 188}Pb by observing the fine structure in the alpha decay of {sup 192}Po.
Luque-Ceballos, Jonathan C.; Posada-Borbón, Alvaro; Herrera-Urbina, Ronaldo; Aceves, R.; Juárez-Sánchez, J. Octavio; Posada-Amarillas, Alvaro
2018-03-01
Spectroscopic properties of gas-phase copper sulfide clusters (CuS)n (n = 2-6) are calculated using Density Functional Theory (DFT) and time-dependent (TD) DFT approaches. The energy landscape of the potential energy surface is explored through a basin-hopping DFT methodology. Ground-state and low-lying isomer structures are obtained. The global search was performed at the B3PW91/SDD level of theory. Normal modes are calculated to validate the existence of optimal cluster structures. Energetic properties are obtained for the ground-state and isomer clusters and their relative energies are evaluated for probing isomerization. This is a few tenths of an eV, except for (CuS)2 cluster, which presents energy differences of ∼1 eV. Notable differences in the infrared spectra exist between the ground-state and first isomer structures, even for the (CuS)5 cluster, which has in both configurations a core copper pyramid. TDDFT provides the simulated absorption spectrum, presenting a theoretical description of optical absorption bands in terms of electronic excitations in the UV and visible regions. Results exhibit a significant dependence of the calculated UV/vis spectra on clusters size and shape regarding the ground state structures. Optical absorption is strong in the UV region, and weak or forbidden in the visible region of the spectrum.
An analysis of stripping to isolated analog resonances
International Nuclear Information System (INIS)
Pessoa, E.F.; Toledo Piza, A.F.R. de.
1983-04-01
The Feshbach projection formalism is used to calculate the form factors for the (d,n) stripping process to isolated analog resonances. These are used in a standard DWBA stripping calculation in which the radial integration over all space is accomplished by including outerspace contributions evaluated along the complex contours of Vincent and Fortune. It turns out that the shape and magnitude of the predicted cross section is quite insensitive to the continuum proton wave emanating from the resonant residual state. (Author) [pt
Shape descriptors for mode-shape recognition and model updating
International Nuclear Information System (INIS)
Wang, W; Mottershead, J E; Mares, C
2009-01-01
The most widely used method for comparing mode shapes from finite elements and experimental measurements is the Modal Assurance Criterion (MAC), which returns a single numerical value and carries no explicit information on shape features. New techniques, based on image processing (IP) and pattern recognition (PR) are described in this paper. The Zernike moment descriptor (ZMD), Fourier descriptor (FD), and wavelet descriptor (WD), presented in this article, are the most popular shape descriptors having properties that include efficiency of expression, robustness to noise, invariance to geometric transformation and rotation, separation of local and global shape features and computational efficiency. The comparison of mode shapes is readily achieved by assembling the shape features of each mode shape into multi-dimensional shape feature vectors (SFVs) and determining the distances separating them.
Energy Technology Data Exchange (ETDEWEB)
Rodriguez Rodriguez; Marco Helio [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, Baja California (Mexico)]. E-mail: marco.rodriguez01@cfe.gob.mx
2009-01-15
Minimal thermodynamic conditions in the Cerro Prieto geothermal reservoir for steam production are defined, taking into account the minimal acceptable steam production at the surface, considering a rank of mixed-enthalpies for different well-depths, and allowing proper assessments for the impacts of the changes in fluid reservoir pressure and enthalpy. Factors able to influence steam production are discussed. They have to be considered when deciding whether or not to drill or repair a well in a particular area of the reservoir. These evaluations become much more relevant by considering the huge thermodynamic changes that have occurred at the Cerro Prieto geothermal reservoir from its development, starting in 1973, which has lead to abandoning some steam producing areas in the field. [Spanish] Las condiciones termodinamicas minimas del yacimiento geotermico de Cerro Prieto, BC, para producir vapor se determinan tomando en cuenta la minima produccion de vapor aceptable en superficie, considerando un rango de entalpias de la mezcla y para diferentes profundidades de pozos, lo que permite valorar adecuadamente el impacto de la evolucion de la presion y entalpia del fluido en el yacimiento. Se discuten los factores que pueden afectar la produccion de vapor, los cuales se deben tomar en cuenta para determinar la conveniencia o no de perforar o reparar un pozo en determinada zona del yacimiento. Estas evaluaciones adquieren gran relevancia al considerar los enormes cambios termodinamicos que ha presentado el yacimiento geotermico de Cerro Prieto, como resultado de su explotacion iniciada en 1973, lo que ha llevado a abandonar algunas zonas del campo para la produccion de vapor. Palabras Clave: Cerro Prieto, entalpia, evaluacion de yacimientos, politicas de explotacion, presion, produccion de vapor.
Symmetric metamaterials based on flower-shaped structure
International Nuclear Information System (INIS)
Tuong, P.V.; Park, J.W.; Rhee, J.Y.; Kim, K.W.; Cheong, H.; Jang, W.H.; Lee, Y.P.
2013-01-01
We proposed new models of metamaterials (MMs) based on a flower-shaped structure (FSS), whose “meta-atoms” consist of two flower-shaped metallic parts separated by a dielectric layer. Like the non-symmetric MMs based on cut-wire-pairs or electric ring resonators, the symmetrical FSS demonstrates the negative permeability at GHz frequencies. Employing the results, we designed a symmetric negative-refractive-index MM [a symmetric combined structure (SCS)], which is composed of FSSs and cross continuous wires. The MM properties of the FSS and the SCS are presented numerically and experimentally. - Highlights: • A new designed of sub-wavelength metamaterial, flower-shaped structure was proposed. • Flower-shaped meta-atom illustrated effective negative permeability. • Based on the meta-atom, negative refractive index was conventionally gained. • Negative refractive index was demonstrated with symmetric properties for electromagnetic wave. • Dimensional parameters were studied under normal electromagnetic wave
Shape memory alloys as damping materials
International Nuclear Information System (INIS)
Humbeeck, J. van
2000-01-01
Shape memory alloys are gaining an increased interest as passive as well as active damping materials. This damping ability when applied in structural elements can lead to a better noise control, improved life time and even better performance of the envisaged tools. By passive damping, it is understood that the material converts a significant part of unwanted mechanical energy into heat. This mechanical energy can be a (resonance) vibration, impact loading or shock waves. This high damping capacity finds its origin in the thermoelastic martensitic phase due to the hysteretic mobility of martensite-variants or different phase interfaces. The damping capacity increases with increasing amplitude of the applied vibration or impact and is almost frequency independent. Special interest exists moreover for damping extreme large displacements by applying the mechanical hysteresis performed during pseudoelastic loading. This aspect is nowadays very strongly studied as a tool for protecting buildings against earthquakes in seismic active regions. Active damping can be obtained in hybrid composites by controlling the recovery stresses or strains of embedded shape memory alloy wires. This controls the internal energy fo a structure which allows controlled modal modification and tuning of the dynamical properties of structural elements. But also impact damage, acoustic radiation, dynamic shape control can be actively controlled. As a consequence improved fatigue-resistance, better performance and a longer lifetime of the structural elements can be obtained. (orig.)
Continuous neutron slowing down theory applied to resonances
International Nuclear Information System (INIS)
Segev, M.
1977-01-01
Neutronic formalisms that discretize the neutron slowing down equations in large numerical intervals currently account for the bulk effect of resonances in a given interval by the narrow resonance approximation (NRA). The NRA reduces the original problem to an efficient numerical formalism through two assumptions: resonance narrowness with respect to the scattering bands in the slowing down equations and resonance narrowness with respect to the numerical intervals. Resonances at low energies are narrow neither with respect to the slowing down ranges nor with respect to the numerical intervals, which are usually of a fixed lethargy width. Thus, there are resonances to which the NRA is not applicable. To stay away from the NRA, the continuous slowing down (CSD) theory of Stacey was invoked. The theory is based on a linear expansion in lethargy of the collision density in integrals of the slowing down equations and had notable success in various problems. Applying CSD theory to the assessment of bulk resonance effects raises the problem of obtaining efficient quadratures for integrals involved in the definition of the so-called ''moderating parameter.'' The problem was solved by two approximations: (a) the integrals were simplified through a rationale, such that the correct integrals were reproduced for very narrow or very wide resonances, and (b) the temperature-broadened resonant line shapes were replaced by nonbroadened line shapes to enable analytical integration. The replacement was made in such a way that the integrated capture and scattering probabilities in each resonance were preserved. The resulting formalism is more accurate than the narrow-resonance formalisms and is equally as efficient
Light squeezing through arbitrarily shaped plasmonic channels and sharp bends
International Nuclear Information System (INIS)
Alu, Andrea; Engheta, Nader
2008-01-01
We propose a mechanism for optical energy squeezing and anomalous light transmission through arbitrarily-shaped plasmonic ultranarrow channels and bends connecting two larger plasmonic metal-insulator-metal waveguides. It is shown how a proper design of subwavelength optical channels at cutoff, patterned by plasmonic implants and connecting larger plasmonic waveguides, may allow enhanced resonant transmission inspired by the anomalous properties of epsilon-near-zero (ENZ) metamaterials. The resonant transmission is shown to be only weakly dependent on the channel length and its specific geometry, such as possible presence of abruptions and bends
Polarization insensitive metamaterial absorber based on E-shaped all-dielectric structure
Directory of Open Access Journals (Sweden)
Liyang Li
2015-03-01
Full Text Available In this paper, we designed a metamaterial absorber performed in microwave frequency band. This absorber is composed of E-shaped dielectrics which are arranged along different directions. The E-shaped all-dielectric structure is made of microwave ceramics with high permittivity and low loss. Within about 1 GHz frequency band, more than 86% absorption efficiency was observed for this metamaterial absorber. This absorber is polarization insensitive and is stable for incident angles. It is figured out that the polarization insensitive absorption is caused by the nearly located varied resonant modes which are excited by the E-shaped all-dielectric resonators with the same size but in the different direction. The E-shaped dielectric absorber contains intensive resonant points. Our research work paves a way for designing all-dielectric absorber.
Electron cyclotron resonance plasma photos
Energy Technology Data Exchange (ETDEWEB)
Racz, R.; Palinkas, J. [Institute of Nuclear Research (ATOMKI), H-4026 Debrecen, Bem ter 18/c (Hungary); University of Debrecen, H-4010 Debrecen, Egyetem ter 1 (Hungary); Biri, S. [Institute of Nuclear Research (ATOMKI), H-4026 Debrecen, Bem ter 18/c (Hungary)
2010-02-15
In order to observe and study systematically the plasma of electron cyclotron resonance (ECR) ion sources (ECRIS) we made a high number of high-resolution visible light plasma photos and movies in the ATOMKI ECRIS Laboratory. This required building the ECR ion source into an open ECR plasma device, temporarily. An 8MP digital camera was used to record photos of plasmas made from Ne, Ar, and Kr gases and from their mixtures. We studied and recorded the effect of ion source setting parameters (gas pressure, gas composition, magnetic field, and microwave power) to the shape, color, and structure of the plasma. The analysis of the photo series gave us many qualitative and numerous valuable physical information on the nature of ECR plasmas.
Electron cyclotron resonance plasma photos
International Nuclear Information System (INIS)
Racz, R.; Palinkas, J.; Biri, S.
2010-01-01
In order to observe and study systematically the plasma of electron cyclotron resonance (ECR) ion sources (ECRIS) we made a high number of high-resolution visible light plasma photos and movies in the ATOMKI ECRIS Laboratory. This required building the ECR ion source into an open ECR plasma device, temporarily. An 8MP digital camera was used to record photos of plasmas made from Ne, Ar, and Kr gases and from their mixtures. We studied and recorded the effect of ion source setting parameters (gas pressure, gas composition, magnetic field, and microwave power) to the shape, color, and structure of the plasma. The analysis of the photo series gave us many qualitative and numerous valuable physical information on the nature of ECR plasmas.
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...
International Nuclear Information System (INIS)
Bohrer, S.P.; Klein, A.; Martin, W.
1985-01-01
''V'' shaped widening of the predens space (PDS) in flexion can be a worrisome finding in traume patients, possibly representing injury to the transverse ligament. These patients may also show widening of the C-1/C-2 interspinous distance. We think this appearance is usually due to increased flexion mobility at the atlantoaxial level with developmental elongation or laxity of the cranial end of the transverse ligament and/or the posterior ligamentous complex. Tearing of only the cranial end of the transverse ligament must be extremely rare, if it occurs at all; there is no reported proven case. Tearing of only posterior ligaments seems possible and should be evaluated clinically. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Ng, H.P. [NUS Graduate School for Integrative Sciences and Engineering (Singapore); Biomedical Imaging Lab., Agency for Science Technology and Research (Singapore); Foong, K.W.C. [NUS Graduate School for Integrative Sciences and Engineering (Singapore); Dept. of Preventive Dentistry, National Univ. of Singapore (Singapore); Ong, S.H. [Dept. of Electrical and Computer Engineering, National Univ. of Singapore (Singapore); Div. of Bioengineering, National Univ. of Singapore (Singapore); Liu, J.; Nowinski, W.L. [Biomedical Imaging Lab., Agency for Science Technology and Research (Singapore); Goh, P.S. [Dept. of Diagnostic Radiology, National Univ. of Singapore (Singapore)
2007-06-15
The masseter plays a critical role in the mastication system. A hybrid method to shape-based interpolation is used to build the masseter model from magnetic resonance (MR) data sets. The main contribution here is the localizing of determinative slices in the data sets where clinicians are required to perform manual segmentations in order for an accurate model to be built. Shape-based criteria were used to locate the candidates for determinative slices and fuzzy-c-means (FCM) clustering technique was used to establish the determinative slices. Five masseter models were built in our work and the average overlap indices ({kappa}) achieved is 85.2%. This indicates that there is good agreement between the models and the manual contour tracings. In addition, the time taken, as compared to manually segmenting all the slices, is significantly lesser. (orig.)
International Nuclear Information System (INIS)
Ng, H.P.; Foong, K.W.C.; Ong, S.H.; Liu, J.; Nowinski, W.L.; Goh, P.S.
2007-01-01
The masseter plays a critical role in the mastication system. A hybrid method to shape-based interpolation is used to build the masseter model from magnetic resonance (MR) data sets. The main contribution here is the localizing of determinative slices in the data sets where clinicians are required to perform manual segmentations in order for an accurate model to be built. Shape-based criteria were used to locate the candidates for determinative slices and fuzzy-c-means (FCM) clustering technique was used to establish the determinative slices. Five masseter models were built in our work and the average overlap indices (κ) achieved is 85.2%. This indicates that there is good agreement between the models and the manual contour tracings. In addition, the time taken, as compared to manually segmenting all the slices, is significantly lesser. (orig.)
Mast Wake Reduction by Shaping
National Research Council Canada - National Science Library
Beauchamp, Charles H
2005-01-01
The present invention relates to various mast shapes, in which the mast shapes minimize the production of visible, electro-optic, infrared and radar cross section wake signatures produced by water surface piercing masts...
Pairwise harmonics for shape analysis
Zheng, Youyi
2013-07-01
This paper introduces a simple yet effective shape analysis mechanism for geometry processing. Unlike traditional shape analysis techniques which compute descriptors per surface point up to certain neighborhoods, we introduce a shape analysis framework in which the descriptors are based on pairs of surface points. Such a pairwise analysis approach leads to a new class of shape descriptors that are more global, discriminative, and can effectively capture the variations in the underlying geometry. Specifically, we introduce new shape descriptors based on the isocurves of harmonic functions whose global maximum and minimum occur at the point pair. We show that these shape descriptors can infer shape structures and consistently lead to simpler and more efficient algorithms than the state-of-the-art methods for three applications: intrinsic reflectional symmetry axis computation, matching shape extremities, and simultaneous surface segmentation and skeletonization. © 2012 IEEE.
Magnetic resonance imaging apparatus
International Nuclear Information System (INIS)
Ehnholm, G.J.
1991-01-01
This patent describes an electron spin resonance enhanced magnetic resonance (MR) imaging (ESREMRI) apparatus able to generate a primary magnetic field during periods of nuclear spin transition excitation and magnetic resonance signal detection. This allows the generation of ESREMRI images of a subject. A primary magnetic field of a second and higher value generated during periods of nuclear spin transition excitation and magnetic resonance signal detection can be used to generate conventional MR images of a subject. The ESREMRI and native MR images so generated may be combined, (or superimposed). (author)
Electron paramagnetic resonance
Al'tshuler, S A
2013-01-01
Electron Paramagnetic Resonance is a comprehensive text on the field of electron paramagnetic resonance, covering both the theoretical background and the results of experiment. This book is composed of eight chapters that cover theoretical materials and experimental data on ionic crystals, since these are the materials that have been most extensively studied by the methods of paramagnetic resonance. The opening chapters provide an introduction to the basic principles of electron paramagnetic resonance and the methods of its measurement. The next chapters are devoted to the theory of spectra an
Ramifide resonators for cyclotrons
International Nuclear Information System (INIS)
Smirnov, Yu.V.
2000-01-01
The resonators with the conductors ramified form for cyclotrons are systematized and separated into the self-contained class - the ramified resonators for cyclotrons (Carr). The ramified resonators are compared with the quarter-wave and half-wave nonramified resonators, accomplished from the transmitting lines fragments. The CRR are classified into two types: ones with the additional structural element, switched in parallel and in series. The CRR may include several additional structural elements. The CRR calculations may be concluded by analytical methods - the method of matrix calculation or the method of telegraph equations and numerical methods - by means of the ISFEL3D, MAFIA and other programs [ru
Zhu, Zhaoxuan; Wiese, Kay Jörg
2017-12-01
In disordered elastic systems, driven by displacing a parabolic confining potential adiabatically slowly, all advance of the system is in bursts, termed avalanches. Avalanches have a finite extension in time, which is much smaller than the waiting time between them. Avalanches also have a finite extension ℓ in space, i.e., only a part of the interface of size ℓ moves during an avalanche. Here we study their spatial shape 〈S(x ) 〉 ℓ given ℓ , as well as its fluctuations encoded in the second cumulant 〈S2(x ) 〉 ℓ c. We establish scaling relations governing the behavior close to the boundary. We then give analytic results for the Brownian force model, in which the microscopic disorder for each degree of freedom is a random walk. Finally, we confirm these results with numerical simulations. To do this properly we elucidate the influence of discretization effects, which also confirms the assumptions entering into the scaling ansatz. This allows us to reach the scaling limit already for avalanches of moderate size. We find excellent agreement for the universal shape and its fluctuations, including all amplitudes.
Issues in Biological Shape Modelling
DEFF Research Database (Denmark)
Hilger, Klaus Baggesen
This talk reflects parts of the current research at informatics and Mathematical Modelling at the Technical University of Denmark within biological shape modelling. We illustrate a series of generalizations, modifications, and applications of the elements of constructing models of shape or appear......This talk reflects parts of the current research at informatics and Mathematical Modelling at the Technical University of Denmark within biological shape modelling. We illustrate a series of generalizations, modifications, and applications of the elements of constructing models of shape...
Embroidered Coils for Magnetic Resonance Sensors
Directory of Open Access Journals (Sweden)
Michael I. Newton
2013-04-01
Full Text Available Magnetic resonance imaging is a widely used technique for medical and materials imaging. Even though the objects being imaged are often irregularly shaped, suitable coils permitting the measurement of the radio-frequency signal in these systems are usually made of solid copper. One problem often encountered is how to ensure the coils are both in close proximity and conformal to the object being imaged. Whilst embroidered conductive threads have previously been used as antennae in mobile telecommunications applications, they have not previously been reported for use within magnetic resonance. In this paper we show that an embroidered single loop coil can be used in a commercial unilateral nuclear magnetic resonance system as an alternative to a solid copper. Data is presented showing the determination of both longitudinal (T1 and effective transverse (T2eff relaxation times for a flat fabric coil and the same coil conformed to an 8 cm diameter cylinder. We thereby demonstrate the principles required for the wider use of fabric based conformal coils within nuclear magnetic resonance and magnetic resonance imaging.
Coherent enhancement of resonance-mediated multiphoton absorption
International Nuclear Information System (INIS)
Zhang, Shian; Zhang, Hui; Jia, Tianqing; Wang, Zugeng; Sun, Zhenrong
2010-01-01
In this paper, we theoretically investigate the coherent enhancement of resonance-mediated (2+2) four-photon absorption. It is found that by shaping the spectral phase with a π phase step, the resonance-mediated (2+2) four-photon transition probability can be enhanced. Furthermore, the coherent enhancement dependences on the detuning between the two two-photon absorptions, laser spectral bandwidth and laser centre frequency are explicitly discussed and analysed. We believe these theoretical results may play an important role in enhancing more complex resonance-mediated multiphoton absorption processes.
Evaluation of stable tungsten isotopes in the resolved resonance region
Directory of Open Access Journals (Sweden)
Schillebeeckx P.
2013-03-01
Full Text Available In the last decade benchmark experiments and simulations, together with newly obtained neutron cross section data, have pointed out deficiencies in evaluated data files of W isotopes. The role of W as a fundamental structural material in different nuclear applications fully justifies a new evaluation of 182, 183, 184, 186W neutron resonance parameters. In this regard transmission and capture cross section measurements on natural and enriched tungsten samples were performed at the GELINA facility of the EC-JRC-IRMM. A resonance parameter file used as input in the resonance shape analysis was prepared based on the available literature and adjusted in first instance to transmission data.
Canonical Skeletons for Shape Matching
Eede, M. van; Macrini, D.; Telea, A.; Sminchisescu, C.; Dickinson, S.
2006-01-01
Skeletal representations of 2-D shape, including shock graphs, have become increasingly popular for shape matching and object recognition. However, it is well known that skeletal structure can be unstable under minor boundary deformation, part articulation, and minor shape deformation (due to, for
Ferromagnetic shape memory materials
Tickle, Robert Jay
Ferromagnetic shape memory materials are a new class of active materials which combine the properties of ferromagnetism with those of a diffusionless, reversible martensitic transformation. These materials have been the subject of recent study due to the unusually large magnetostriction exhibited in the martensitic phase. In this thesis we report the results of experiments which characterize the magnetic and magnetomechanical properties of both austenitic and martensitic phases of ferromagnetic shape memory material Ni2MnGa. In the high temperature cubic phase, anisotropy and magnetostriction constants are determined for a range of temperatures from 50°C down to the transformation temperature, with room temperature values of K1 = 2.7 +/- 104 ergs/cm3 and lambda100 = -145 muepsilon. In the low temperature tetragonal phase, the phenomenon of field-induced variant rearrangement is shown to produce anomalous results when traditional techniques for determining anisotropy and magnetostriction properties are employed. The requirement of single variant specimen microstructure is explained, and experiments performed on such a specimen confirm a uniaxial anisotropy within each martensitic variant with anisotropy constant Ku = 2.45 x 106 ergs/cm3 and a magnetostriction constant of lambdasv = -288 +/- 73 muepsilon. A series of magnetomechanical experiments investigate the effects of microstructure bias, repeated field cycling, varying field ramp rate, applied load, and specimen geometry on the variant rearrangement phenomenon in the martensitic phase. In general, the field-induced strain is found to be a function of the variant microstructure. Experiments in which the initial microstructure is biased towards a single variant state with an applied load generate one-time strains of 4.3%, while those performed with a constant bias stress of 5 MPa generate reversible strains of 0.5% over a period of 50 cycles. An increase in the applied field ramp rate is shown to reduce the
Interaction between confined phonons and photons in periodic silicon resonators
Iskandar, A.; Gwiazda, A.; Younes, J.; Kazan, M.; Bruyant, A.; Tabbal, M.; Lerondel, G.
2018-03-01
In this paper, we demonstrate that phonons and photons of different momenta can be confined and interact with each other within the same nanostructure. The interaction between confined phonons and confined photons in silicon resonator arrays is observed by means of Raman scattering. The Raman spectra from large arrays of dielectric silicon resonators exhibited Raman enhancement accompanied with a downshift and broadening. The analysis of the Raman intensity and line shape using finite-difference time-domain simulations and a spatial correlation model demonstrated an interaction between photons confined in the resonators and phonons confined in highly defective regions prompted by the structuring process. It was shown that the Raman enhancement is due to collective lattice resonance inducing field confinement in the resonators, while the spectra downshift and broadening are signatures of the relaxation of the phonon wave vector due to phonon confinement in defective regions located in the surface layer of the Si resonators. We found that as the resonators increase in height and their shape becomes cylindrical, the amplitude of their coherent oscillation increases and hence their ability to confine the incoming electric field increases.
DEFF Research Database (Denmark)
Park, Kidong; Shim, Jeong; Solovyeva, Vita
2012-01-01
We examined the hydrodynamic loading of vertically resonating microfabricated plates immersed in liquids with different viscosities. The planar structures were patterned with focused ion beam, perforating various shapes with identical area but varying perimeters. The hydrodynamic loading of various...
Effect of Initial Curvature on the Static and Dynamic Behavior of MEMS Resonators
Hajjaj, Amal Z.; Alcheikh, Nouha; Younis, Mohammad I.
2017-01-01
In this paper, we investigate experimentally and analytically the effect of the initial shape, arc and cosine wave, on the static and dynamic behavior of microelectromechanical (MEMS) resonators. We show that by carefully choosing the geometrical
A Gauss-Newton method for the integration of spatial normal fields in shape Space
Balzer, Jonathan
2011-08-09
We address the task of adjusting a surface to a vector field of desired surface normals in space. The described method is entirely geometric in the sense, that it does not depend on a particular parametrization of the surface in question. It amounts to solving a nonlinear least-squares problem in shape space. Previously, the corresponding minimization has been performed by gradient descent, which suffers from slow convergence and susceptibility to local minima. Newton-type methods, although significantly more robust and efficient, have not been attempted as they require second-order Hadamard differentials. These are difficult to compute for the problem of interest and in general fail to be positive-definite symmetric. We propose a novel approximation of the shape Hessian, which is not only rigorously justified but also leads to excellent numerical performance of the actual optimization. Moreover, a remarkable connection to Sobolev flows is exposed. Three other established algorithms from image and geometry processing turn out to be special cases of ours. Our numerical implementation founds on a fast finite-elements formulation on the minimizing sequence of triangulated shapes. A series of examples from a wide range of different applications is discussed to underline flexibility and efficiency of the approach. © 2011 Springer Science+Business Media, LLC.
Digital pulse shape discrimination
International Nuclear Information System (INIS)
Miller, L. F.; Preston, J.; Pozzi, S.; Flaska, M.; Neal, J.
2007-01-01
Pulse-shape discrimination (PSD) has been utilised for about 40 years as a method to obtain estimates for dose in mixed neutron and photon fields. Digitizers that operate close to GHz are currently available at a reasonable cost, and they can be used to directly sample signals from photomultiplier tubes. This permits one to perform digital PSD rather than the traditional, and well-established, analogous techniques. One issue that complicates PSD for neutrons in mixed fields is that the light output characteristics of typical scintillators available for PSD, such as BC501A, vary as a function of energy deposited in the detector. This behaviour is more easily accommodated with digital processing of signals than with analogous signal processing. Results illustrate the effectiveness of digital PSD. (authors)
Salzbrenner, R.
1984-06-01
The mechanical shape memory effect associated with a thermoelastic martensitic transformation can be used to convert heat directly into mechanical work. Laboratory simulation of two types of heat engine cycles (Stirling and Ericsson) has been performed to measure the amount of work available/cycle in a Ni-45 at. pct Ti alloy. Tensile deformations at ambient temperature induced martensite, while a subsequent increase in temperature caused a reversion to the parent phase during which a load was carried through the strain recovery (i.e., work was accomplished). The amount of heat necessary to carry the engines through a cycle was estimated from calorimeter measurements and the work performed/cycle. The measured efficiency of the system tested reached a maximum of 1.4 percent, which was well below the theoretical (Carnot) maximum efficiency of 35.6 percent.
DEFF Research Database (Denmark)
Andersen, Susan; Tolstrup, Janne Schurmann; Rod, Morten Hulvej
2015-01-01
is a comprehensive programme integrating social and educational activities to promote student well-being and reduce smoking and dropout in upper secondary vocational education. The evaluation design is reported here. METHODS/DESIGN: The evaluation employed a non-randomised cluster controlled design, and schools were...... % and 81 % of eligible students, and 22 % of all technical/agricultural vocational schools in Denmark. Follow-up assessment was conducted 10 weeks after baseline and at the same time teachers of the intervention classes answered a questionnaire about implementation. School dropout rates will be tracked via...... national education registers through a 2-year follow-up period. DISCUSSION: Shaping the Social was designed to address that students at Danish vocational schools constitute a high risk population concerning health behaviour as well as school dropout by modifying the school environment, alongside developing...
International Nuclear Information System (INIS)
Schlaffer, Matthias; Spannowsky, Michael; Wymant, Chris
2014-05-01
The inclusive Higgs production rate through gluon fusion has been measured to be in agreement with the Standard Model (SM). We show that even if the inclusive Higgs production rate is very SM-like, a precise determination of the boosted Higgs transverse momentum shape offers the opportunity to see effects of natural new physics. These measurements are generically motivated by effective field theory arguments and specifically in extensions of the SM with a natural weak scale, like composite Higgs models and natural supersymmetry. We show in detail how a measurement at high transverse momentum of H→2l+p T via H→ττ and H→WW * could be performed and demonstrate that it offers a compelling alternative to the t anti tH channel. We discuss the sensitivity to new physics in the most challenging scenario of an exactly SM-like inclusive Higgs cross-section.
Geometric Topology and Shape Theory
Segal, Jack
1987-01-01
The aim of this international conference the third of its type was to survey recent developments in Geometric Topology and Shape Theory with an emphasis on their interaction. The volume contains original research papers and carefully selected survey of currently active areas. The main topics and themes represented by the papers of this volume include decomposition theory, cell-like mappings and CE-equivalent compacta, covering dimension versus cohomological dimension, ANR's and LCn-compacta, homology manifolds, embeddings of continua into manifolds, complement theorems in shape theory, approximate fibrations and shape fibrations, fibered shape, exact homologies and strong shape theory.
Luo, E C; Ling, H; Dai, W; Yu, G Y
2006-12-22
In this paper, an experimental study of the effect of the resonator shape on the performance of a traveling-wave thermoacoustic engine is presented. Two different resonators were tested in the thermoacoustic-Stirling heat. One resonator is an iso-diameter one, and the other is a tapered one. To have a reasonable comparison reference, we keep the same traveling-wave loop, the same resonant frequency and the same operating pressure. The experiment showed that the resonator shape has significant influence on the global performance of the thermoacoustic-Stirling heat engine. The tapered resonator gives much better performance than the iso-diameter resonator. The tapered resonator system achieved a maximum pressure ratio of about 1.3, a maximum net acoustical power output of about 450 W and a highest thermoacoustic efficiency of about 25%.
International Nuclear Information System (INIS)
Kumar, K.
1979-01-01
It has been shown that the gross features of the collective spectra of even-even nuclei ranging from 12 C to 240 Pu are reproduced by the dynamic deformation model without any fitting parameters. We apply another test to be same model in the present study. Can this single model explain three seemingly different types of shape co-existence proposed previously: spherical op-oh and deformed 2p-2h shapes in 16 O, spherical and prolate-deformed minima in the potential energy surface of 72 Se, ground state shape and fission isomer shape of 240 Pu. Of these three nuclei, only the nucleus 72 Se is off the line of beta-stability. The calculated potential energy surfaces and collective spectra of 16 O, 72 Se, and 240 Pu are discussed and compared with experiments. The three different kinds of shape coexistence proposed previously for 16 O, 72 Se, and 240 Pu are all reproduced by the present version of the dynamic deformation model within the same model and without any fitting parameters. We conclude that the combination of the dynamics of the nine-dimensional quadrupole and pairing motions with a large space microscopic calculation provides a rather powerful tool for studying practically all even-even nuclei
Controlling Parametric Resonance
DEFF Research Database (Denmark)
Galeazzi, Roberto; Pettersen, Kristin Ytterstad
2012-01-01
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...
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:
Electromagnetic resonance waves
International Nuclear Information System (INIS)
Villaba, J.M.; Manjon, F.J.; Guirao, A.; Andres, M.V.
1994-01-01
We describe in this paper a set of experiments designed to make qualitative and quantitative measurements on electromagnetic resonances of several simple systems. The experiments are designed for the undergraduate laboratory of Electricity and Magnetism in Physics. These experiments can help the students understanding the concept of resonance, which appears in different fields of Physics. (Author) 8 refs
Laser magnetic resonance spectroscopy
International Nuclear Information System (INIS)
Ferrari, C.A.
1985-01-01
The technique of laser resonance magnetic resonance allows one to study the high-resolution spectroscopy of transient paramagnetic species, viz, atoms, radicals, and molecular ions. This article is a brief exposition of the method, describing the principles, instrumentation and applicability of the IR and FIR-LMR and shows results of HF + . (Author) [pt
Resonance and Fractal Geometry
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
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: https://www.ias.ac.in/article/fulltext/reso/009/01/0034-0049. Keywords.
Cardiac magnetic resonance imaging
African Journals Online (AJOL)
2011-03-06
Mar 6, 2011 ... Cardiac magnetic resonance imaging. Cardiovascular magnetic resonance imaging is becoming a routine diagnostic technique. BRUCE s sPOTTiswOOdE, PhD. MRC/UCT Medical Imaging Research Unit, University of Cape Town, and Division of Radiology, Stellenbosch University. Bruce Spottiswoode ...
Energy Technology Data Exchange (ETDEWEB)
Ferdinand, Benedikt; Wiedmaier, Dominik; Koelle, Dieter; Kleiner, Reinhold [Physikalisches Institut and Center for Quantum Science in LISA+, Universitaet Tuebingen (Germany); Bothner, Daniel [Physikalisches Institut and Center for Quantum Science in LISA+, Universitaet Tuebingen (Germany); Kavli Institute of Nanoscience, Delft University of Technology, Delft (Netherlands)
2016-07-01
We intend to investigate a hybrid quantum system where ultracold atomic gases play the role of a long-living quantum memory, coupled to a superconducting qubit via a coplanar waveguide transmission line resonator. As a first step we developed a resonator chip containing a Z-shaped trapping wire for the atom trap. In order to suppress parasitic resonances due to stray capacitances, and to achieve good ground connection we use hybrid superconductor - normal conductor chips. As an additional degree of freedom we add a ferroelectric capacitor making the resonators voltage-tunable. We furthermore show theoretical results on the expected coupling strength between resonator and atomic cloud.
Fundamentals of nanomechanical resonators
Schmid, Silvan; Roukes, Michael Lee
2016-01-01
This authoritative book introduces and summarizes the latest models and skills required to design and optimize nanomechanical resonators, taking a top-down approach that uses macroscopic formulas to model the devices. The authors cover the electrical and mechanical aspects of nano electromechanical system (NEMS) devices. The introduced mechanical models are also key to the understanding and optimization of nanomechanical resonators used e.g. in optomechanics. Five comprehensive chapters address: The eigenmodes derived for the most common continuum mechanical structures used as nanomechanical resonators; The main sources of energy loss in nanomechanical resonators; The responsiveness of micro and nanomechanical resonators to mass, forces, and temperature; The most common underlying physical transduction mechanisms; The measurement basics, including amplitude and frequency noise. The applied approach found in this book is appropriate for engineering students and researchers working with micro and nanomechanical...
Lai, Jih-Sheng; Young, Sr., Robert W.; Chen, Daoshen; Scudiere, Matthew B.; Ott, Jr., George W.; White, Clifford P.; McKeever, John W.
1997-01-01
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.
Rotor Embedded with Shape Memory Alloy Wires
Directory of Open Access Journals (Sweden)
K. Gupta
2000-01-01
Full Text Available In the present analysis, the fundamental natural frequency of a Jeffcott and a two-mass rotor with fibre reinforced composite shaft embedded with shape memory alloy (SMA wires is evaluated by Rayleigh's procedure. The flexibility of rotor supports is taken into account. The effect of three factors, either singly or in combination with each other, on rotor critical speed is studied. The three factors are: (i increase in Young's modulus of SMA (NITINOL wires when activated, (ii tension in wires because of phase recovery stresses, and (iii variation of support stiffness by three times because of activation of SMA in rotor supports. It is shown by numerical examples that substantial variation in rotor critical speeds can be achieved by a combination of these factors which can be effectively used to avoid resonance during rotor coast up/down.
Designing H-shaped micromechanical filters
International Nuclear Information System (INIS)
Arhaug, O P; Soeraasen, O
2006-01-01
This paper investigates the design constraints and possibilities given when designing a micromechanical band pass filter for intermediate frequencies (e.g. 10 MHz). The class of filters are based on coupled clamped-clamped beams constituting an H-shaped structure. A primary beam can electrostatically be activated in one of its different harmonic modes, setting the filter center frequency. The motion is transferred to an accompanying beam of equal dimensions by a mechanical coupling beam. The placement or coupling points of the quarterwavelength coupling beam which connects the vertically resonating beams is critical with respect to the bandwidth of the filters. Of special concern has been to investigate realistic dimensions allowing the filters to be processed by an actual foundry process and to find out how the choice of materials and actual dimensions would affect the performance
Low losses left-handed materials with optimized electric and magnetic resonance
Zhou, Xin; Liu, Yahong; Zhao, Xiaopeng
2010-03-01
We propose that the losses in left-handed materials (LHMs) can be significantly affected by changing the coupling relationship between electric and magnetic resonance. A double bowknot shaped structure (DBS) is used to construct the LHMs. And the magnetic resonance of the DBS, which resonated in the case of lower and higher frequencies than the electric resonant dip, is studied in simulation and experiment by tailoring the structural parameters. The case of magnetic resonance located at low electric resonance frequencies band is confirmed to have relatively low losses. Using full wave simulation of prism shaped structure composed of DBS unit cells, we prove the negative refraction behavior in such a frame. This study can serve as a guide for designing other similar metal-dielectric-metal (MDM) in low losses at terahertz or higher frequencies.
First observation of the Λ(1405) line shape in electroproduction
Lu, H. Y.; Schumacher, R. A.; Adhikari, K. P.; Adikaram, D.; Aghasyan, M.; Amaryan, M. J.; Pereira, S. Anefalos; Ball, J.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A. S.; Boiarinov, S.; Briscoe, W. J.; Brooks, W. K.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Cole, P. L.; Collins, P.; Contalbrigo, M.; Cortes, O.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Doughty, D.; Dupre, R.; Egiyan, H.; Alaoui, A. El; Fassi, L. El; Eugenio, P.; Fedotov, G.; Fegan, S.; Fleming, J. A.; Gabrielyan, M.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Guo, L.; Hafidi, K.; Hakobyan, H.; Harrison, N.; Heddle, D.; Hicks, K.; Ho, D.; Holtrop, M.; Hyde, C. E.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jo, H. S.; Joo, K.; Keller, D.; Khandaker, M.; Kim, W.; Klein, A.; Klein, F. J.; Koirala, S.; Kubarovsky, A.; Kubarovsky, V.; Kuleshov, S. V.; Lewis, S.; Livingston, K.; MacGregor, I. J. D.; Martinez, D.; Mayer, M.; McKinnon, B.; Meyer, C. A.; Mineeva, T.; Mirazita, M.; Mokeev, V.; Montgomery, R. A.; Moriya, K.; Moutarde, H.; Munevar, E.; Camacho, C. Munoz; Nadel-Turonski, P.; Nepali, C. S.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Pappalardo, L. L.; Paremuzyan, R.; Park, K.; Park, S.; Pasyuk, E.; Peng, P.; Phelps, E.; Phillips, J. J.; Pisano, S.; Pogorelko, O.; Pozdniakov, S.; Price, J. W.; Procureur, S.; Prok, Y.; Protopopescu, D.; Puckett, A. J. R.; Raue, B. A.; Rimal, D.; Ripani, M.; Rosner, G.; Rossi, P.; Sabatié, F.; Saini, M. S.; Salgado, C.; Schott, D.; Seder, E.; Seraydaryan, H.; Sharabian, Y. G.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Stepanyan, S. S.; Stoler, P.; Strauch, S.; Taiuti, M.; Tang, W.; Tian, Ye; Tkachenko, S.; Torayev, B.; Vernarsky, B.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Weygand, D. P.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z. W.
2013-10-01
We report the first observation of the line shape of the Λ(1405) from electroproduction, and show that it is not a simple Breit-Wigner resonance. Electroproduction of K+Λ(1405) off the proton was studied by using data from CLAS at Jefferson Lab in the range 1.0
Advances in magnetic resonance 10
Waugh, John S
2013-01-01
Advances in Magnetic Resonance, Volume 10, presents a variety of contributions to the theory and practice of magnetic resonance. The book contains three chapters that examine superoperators in magnetic resonance; ultrasonically modulated paramagnetic resonance; and the utility of electron paramagnetic resonance (EPR) and electron-nuclear double-resonance (ENDOR) techniques for studying low-frequency modes of atomic fluctuations and their significance for understanding the mechanism of structural phase transitions in solids.
A Map for a Group of Resonant Cases in a Quartic Galactic ...
Indian Academy of Sciences (India)
R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22
used in order to find the x − px Poincare phase plane for each resonance. ... tori give birth to families of regular orbits with similar shape to that of the parent resonant ..... of and the stability characteristics are the same for the two phase planes.
International Nuclear Information System (INIS)
Elliott, C.J.; Feldman, B.J.
1979-02-01
A detailed theoretical analysis is presented of the interaction of intense near-resonant monochromatic radiation with an N-level anharmonic oscillator. In particular, the phenomenon of multiple photon resonance, the process by which an N-level system resonantly absorbs two or more photons simultaneously, is investigated. Starting from the Schroedinger equation, diagrammatic techniques are developed that allow the resonant process to be analyzed quantitatively, in analogy with well-known two-level coherent phenomena. In addition, multiple photon Stark shifts of the resonances, shifts absent in two-level theory, are obtained from the diagrams. Insights into the nature of multiple photon resonances are gained by comparing the quantum mechanical system with classical coupled pendulums whose equations of motion possess identical eigenvalues and eigenvectors. In certain limiting cases, including that of the resonantly excited N-level harmonic oscillator and that of the equally spaced N-level system with equal matrix elements, analytic results are derived. The influence of population relaxation and phase-disrupting collisions on the multiple photon process are also analyzed, the latter by extension of the diagrammatic technique to the density matrix equations of motion. 11 figures
Properties of spiral resonators
International Nuclear Information System (INIS)
Haeuser, J.
1989-10-01
The present thesis deals with the calculation and the study of the application possibilities of single and double spiral resonators. The main aim was the development and the construction of reliable and effective high-power spiral resonators for the UNILAC of the GSI in Darmstadt and the H - -injector for the storage ring HERA of DESY in Hamburg. After the presentation of the construction and the properties of spiral resonators and their description by oscillating-circuit models the theoretical foundations of the bunching are presented and some examples of a rebuncher and debuncher and their influence on the longitudinal particle dynamics are shown. After the description of the characteristic accelerator quantities by means of an oscillating-circuit model and the theory of an inhomogeneous λ/4 line it is shown, how the resonance frequency and the efficiency of single and double spiral resonators can be calculated from the geometrical quantities of the structure. In the following the dependence of the maximal reachable resonator voltage in dependence on the gap width and the surface of the drift tubes is studied. Furthermore the high-power resonators are presented, which were built for the different applications for the GSI in Darmstadt, DESY in Hamburg, and for the FOM Institute in Amsterdam. (orig./HSI) [de
Structural resonance and mode of flutter of hummingbird tail feathers.
Clark, Christopher J; Elias, Damian O; Girard, Madeline B; Prum, Richard O
2013-09-15
Feathers can produce sound by fluttering in airflow. This flutter is hypothesized to be aeroelastic, arising from the coupling of aerodynamic forces to one or more of the feather's intrinsic structural resonance frequencies. We investigated how mode of flutter varied among a sample of hummingbird tail feathers tested in a wind tunnel. Feather vibration was measured directly at ~100 points across the surface of the feather with a scanning laser Doppler vibrometer (SLDV), as a function of airspeed, Uair. Most feathers exhibited multiple discrete modes of flutter, which we classified into types including tip, trailing vane and torsional modes. Vibratory behavior within a given mode was usually stable, but changes in independent variables such as airspeed or orientation sometimes caused feathers to abruptly 'jump' from one mode to another. We measured structural resonance frequencies and mode shapes directly by measuring the free response of 64 feathers stimulated with a shaker and recorded with the SLDV. As predicted by the aeroelastic flutter hypothesis, the mode shape (spatial distribution) of flutter corresponded to a bending or torsional structural resonance frequency of the feather. However, the match between structural resonance mode and flutter mode was better for tip or torsional mode shapes, and poorer for trailing vane modes. Often, the 3rd bending structural harmonic matched the expressed mode of flutter, rather than the fundamental. We conclude that flutter occurs when airflow excites one or more structural resonance frequencies of a feather, most akin to a vibrating violin string.
Electron scattering from CO in the 2Pi resonance region
International Nuclear Information System (INIS)
Buckman, S.J.; Lohmann, B.
1986-01-01
The total cross section for electron scattering from CO in the energy range 0.5--5 eV has been measured with use of a time-of-flight spectrometer. This energy region encompasses the 2 π shape resonance, and a comparison is made with other experimental and theoretical results with regard to the magnitude and position of this structure
Resonance – Journal of Science Education | Indian Academy of ...
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 12. What are the shapes of the f - orbitals. K L Sebastian. Think It Over Volume 2 Issue 12 December 1997 pp 88-91. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/002/12/0088-0091 ...
Vaccines: Shaping global health.
Pagliusi, Sonia; Ting, Ching-Chia; Lobos, Fernando
2017-03-14
The Developing Countries Vaccine Manufacturers' Network (DCVMN) gathered leaders in immunization programs, vaccine manufacturing, representatives of the Argentinean Health Authorities and Pan American Health Organization, among other global health stakeholders, for its 17th Annual General Meeting in Buenos Aires, to reflect on how vaccines are shaping global health. Polio eradication and elimination of measles and rubella from the Americas is a result of successful collaboration, made possible by timely supply of affordable vaccines. After decades of intense competition for high-value markets, collaboration with developing countries has become critical, and involvement of multiple manufacturers as well as public- and private-sector investments are essential, for developing new vaccines against emerging infectious diseases. The recent Zika virus outbreak and the accelerated Ebola vaccine development exemplify the need for international partnerships to combat infectious diseases. A new player, Coalition for Epidemic Preparedness Innovations (CEPI) has made its entrance in the global health community, aiming to stimulate research preparedness against emerging infections. Face-to-face panel discussions facilitated the dialogue around challenges, such as risks of viability to vaccine development and regulatory convergence, to improve access to sustainable vaccine supply. It was discussed that joint efforts to optimizing regulatory pathways in developing countries, reducing registration time by up to 50%, are required. Outbreaks of emerging infections and the global Polio eradication and containment challenges are reminders of the importance of vaccines' access, and of the importance of new public-private partnerships. Copyright © 2017.
An extension of command shaping methods for controlling residual vibration using frequency sampling
Singer, Neil C.; Seering, Warren P.
1992-01-01
The authors present an extension to the impulse shaping technique for commanding machines to move with reduced residual vibration. The extension, called frequency sampling, is a method for generating constraints that are used to obtain shaping sequences which minimize residual vibration in systems such as robots whose resonant frequencies change during motion. The authors present a review of impulse shaping methods, a development of the proposed extension, and a comparison of results of tests conducted on a simple model of the space shuttle robot arm. Frequency shaping provides a method for minimizing the impulse sequence duration required to give the desired insensitivity.
Magnetic Resonance Force Microscopy System
Federal Laboratory Consortium — The Magnetic Resonance Force Microscopy (MRFM) system, developed by ARL, is the world's most sensitive nuclear magnetic resonance (NMR) spectroscopic analysis tool,...
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
Excitation of Nucleon Resonances
International Nuclear Information System (INIS)
Burkert, Volker D.
2001-01-01
I discuss developments in the area of nucleon resonance excitation, both necessary and feasible, that would put our understanding of nucleon structure in the regime of strong QCD on a qualitatively new level. They involve the collection of high quality data in various channels, a more rigorous approach in the search for ''missing'' resonances, an effort to compute some critical quantities in nucleon resonance excitations from first principles, i.e. QCD, and a proposal focused to obtain an understanding of a fundamental quantity in nucleon structure
Dihadronic and dileptonic resonances
International Nuclear Information System (INIS)
Gareev, F.A.; Barabanov, M.Yu.; Kazacha, G.S.
1997-01-01
Simple phenomenological rules are suggested for calculation of dihadron and dilepton resonance masses. A general interpretation is given for different exotic resonances in nuclear physics: Darmstadt-effect, dibaryon, dipion and other resonances. Information about the inner structure of e ± , proton, neutron, pions and so on can be obtained from the usual reactions of the type e + + e - =>γγ, e ± +γ=>e ± γ, e ± μ ± , e ± N... at low, intermediate and high energies using existing experimental devices
International Nuclear Information System (INIS)
Shahbazian, B.A.
1982-01-01
The invariant mass spectra of forty nine hadronic systems with hypercharge, strangeness and baryon number, varied in wide limits have been studied. Resonance peaks have been found in the invariant mass spectra of Y 2 and #betta#pπ 2495 MeV/c 2 resonant states. Three more candidates for anti qq 4 states were found #bettaπ# + π + : 1705, 2072, 2605 MeV/c 2 . The masses of all these candidates are in good agreement with Bag Model predictions. A hypercharge selection rule is suggested: ''The hypercharge of hadronic resonances in weak gravitational fields cannot exceed one Y <= 1
Resonant halide perovskite nanoparticles
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.
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 two......, 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....
Doubly resonant multiphoton ionization
International Nuclear Information System (INIS)
Crance, M.
1978-01-01
A particular case of doubly resonant multiphoton ionization is theoretically investigated. More precisely, two levels quasi-resonant with two successive harmonics of the field frequency are considered. The method used is based on the effective operator formalism first introduced for this problem by Armstrong, Beers and Feneuille. The main result is to show the possibility of observing large interference effects on the width of the resonances. Moreover this treatment allows us to make more precise the connection between effective operator formalism and standard perturbation theory
Combined Shape and Topology Optimization
DEFF Research Database (Denmark)
Christiansen, Asger Nyman
Shape and topology optimization seeks to compute the optimal shape and topology of a structure such that one or more properties, for example stiffness, balance or volume, are improved. The goal of the thesis is to develop a method for shape and topology optimization which uses the Deformable...... Simplicial Complex (DSC) method. Consequently, we present a novel method which combines current shape and topology optimization methods. This method represents the surface of the structure explicitly and discretizes the structure into non-overlapping elements, i.e. a simplicial complex. An explicit surface...... representation usually limits the optimization to minor shape changes. However, the DSC method uses a single explicit representation and still allows for large shape and topology changes. It does so by constantly applying a set of mesh operations during deformations of the structure. Using an explicit instead...
Shape Synthesis in Mechanical Design
C. P. Teng; S. Bai; J. Angeles
2007-01-01
The shaping of structural elements in the area of mechanical design is a recurrent problem. The mechanical designer, as a rule, chooses what is believed to be the “simplest” shapes, such as the geometric primitives: lines, circles and, occasionally, conics. The use of higher-order curves is usually not even considered, not to speak of other curves than polynomials. However, the simplest geometric shapes are not necessarily the most suitable when the designed element must withstand loads that ...
Virtual Technologies and Social Shaping
Kreps , David
2010-01-01
International audience; Virtual Technologies have enabled us all to become publishers and broadcasters. The world of information has become saturated with a multitude of opinions, and opportunities to express them. Track 2 "Virtual Technologies and Social Shaping" of the 9th Conference on Human Choice and Computers (HCC9) explores some of the issues that have arisen in this new information society, how we are shaped by it, and how we shape it, through i) two papers addressing issues of identi...
Parametric resonance of intrinsic localized modes in coupled cantilever arrays
Energy Technology Data Exchange (ETDEWEB)
Kimura, Masayuki, E-mail: kimura.masayuki.8c@kyoto-u.ac.jp [Department of Electrical Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan); Matsushita, Yasuo [Advanced Mathematical Institute, Osaka City University, 3-3-138 Sughimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan); Hikihara, Takashi [Department of Electrical Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan)
2016-08-19
In this study, the parametric resonances of pinned intrinsic localized modes (ILMs) were investigated by computing the unstable regions in parameter space consisting of parametric excitation amplitude and frequency. In the unstable regions, the pinned ILMs were observed to lose stability and begin to fluctuate. A nonlinear Klein–Gordon, Fermi–Pasta–Ulam-like, and mixed lattices were investigated. The pinned ILMs, particularly in the mixed lattice, were destabilized by parametric resonances, which were determined by comparing the shapes of the unstable regions with those in the Mathieu differential equation. In addition, traveling ILMs could be generated by parametric excitation. - Highlights: • Destabilization of intrinsic localized modes (ILMs) by parametric excitation is investigated for FPU, NKG, and mixed lattices. • Frequency and amplitude of parametric excitation is determined based on characteristic multipliers of ILMs. • Unstable regions for the mixed lattice case show very similar shape to those of the Mathieu equation. • ILMs become unstable by causing parametric resonance.
Parametric resonance of intrinsic localized modes in coupled cantilever arrays
International Nuclear Information System (INIS)
Kimura, Masayuki; Matsushita, Yasuo; Hikihara, Takashi
2016-01-01
In this study, the parametric resonances of pinned intrinsic localized modes (ILMs) were investigated by computing the unstable regions in parameter space consisting of parametric excitation amplitude and frequency. In the unstable regions, the pinned ILMs were observed to lose stability and begin to fluctuate. A nonlinear Klein–Gordon, Fermi–Pasta–Ulam-like, and mixed lattices were investigated. The pinned ILMs, particularly in the mixed lattice, were destabilized by parametric resonances, which were determined by comparing the shapes of the unstable regions with those in the Mathieu differential equation. In addition, traveling ILMs could be generated by parametric excitation. - Highlights: • Destabilization of intrinsic localized modes (ILMs) by parametric excitation is investigated for FPU, NKG, and mixed lattices. • Frequency and amplitude of parametric excitation is determined based on characteristic multipliers of ILMs. • Unstable regions for the mixed lattice case show very similar shape to those of the Mathieu equation. • ILMs become unstable by causing parametric resonance.
Women in Shape Modeling Workshop
Tari, Sibel
2015-01-01
Presenting the latest research from the growing field of mathematical shape analysis, this volume is comprised of the collaborations of participants of the Women in Shape Modeling (WiSh) workshop, held at UCLA's Institute for Pure and Applied Mathematics in July 2013. Topics include: Simultaneous spectral and spatial analysis of shape Dimensionality reduction and visualization of data in tree-spaces, such as classes of anatomical trees like airways and blood vessels Geometric shape segmentation, exploring shape segmentation from a Gestalt perspective, using information from the Blum medial axis of edge fragments in an image Representing and editing self-similar details on 3D shapes, studying shape deformation and editing techniques Several chapters in the book directly address the problem of continuous measures of context-dependent nearness and right shape models. Medical and biological applications have been a major source of motivation in shape research, and key topics are examined here in detail. All...
Coherent control through near-resonant Raman transitions
International Nuclear Information System (INIS)
Dai Xingcan; Lerch, Eliza-Beth W.; Leone, Stephen R.
2006-01-01
The phase of an electronic wave function is shown to play an important role in coherent control experiments. By using a pulse shaping system with a femtosecond laser, we explore the phase relationships among resonant and off-resonant Raman transitions in Li 2 by measuring the phases of the resulting wave packets, or quantum beats. Specific pixels in a liquid-crystal spatial light modulator are used to isolate the resonant and off-resonant portions of the Raman transitions in Li 2 . The off-resonant Raman transitions have an approximately 90 degree sign phase shift with respect to the resonant Raman transition, and there is an approximately 180 degree sign phase shift between the blue-detuned and the red-detuned off-resonant Raman transitions. Calculations using second-order time-dependent perturbation theory for the electronic transitions agree with the experimental results for the laser pulse intensities used here. Interferences between the off-resonant Raman transitions as a function of detuning are used to demonstrate coherent control of the Raman quantum wave packet
A Multilevel Shape Fit Analysis of Neutron Transmission Data
Naguib, K.; Sallam, O. H.; Adib, M.; Ashry, A.
A multilevel shape fit analysis of neutron transmission data is presented. A multilevel computer code SHAPE is used to analyse clean transmission data obtained from time-of-flight (TOF) measurements. The shape analysis deduces the parameters of the observed resonances in the energy region considered in the measurements. The shape code is based upon a least square fit of a multilevel Briet-Wigner formula and includes both instrumental resolution and Doppler broadenings. Operating the SHAPE code on a test example of a measured transmission data of 151Eu, 153Eu and natural Eu in the energy range 0.025-1 eV accquired a good result for the used technique of analysis.Translated AbstractAnalyse von Neutronentransmissionsdaten mittels einer VielniveauformanpassungNeutronentransmissionsdaten werden in einer Vielniveauformanpassung analysiert. Dazu werden bereinigte Daten aus Flugzeitmessungen mit dem Rechnerprogramm SHAPE bearbeitet. Man erhält die Parameter der beobachteten Resonanzen im gemessenen Energiebereich. Die Formanpassung benutzt eine Briet-Wignerformel und berücksichtigt Linienverbreiterungen infolge sowohl der Meßeinrichtung als auch des Dopplereffekts. Als praktisches Beispiel werden 151Eu, 153Eu und natürliches Eu im Energiebereich 0.025 bis 1 eV mit guter Übereinstimmung theoretischer und experimenteller Werte behandelt.
Magnetic Resonance (MR) Defecography
... to a CD or uploaded to a digital cloud server. Magnetic resonance (MR) defecography is a special ... with you. top of page What are the benefits vs. risks? Benefits MR defecography helps assess pelvic ...
International Nuclear Information System (INIS)
Heller, E.J.
1996-01-01
It is well known that at long wavelengths λ an s-wave scatterer can have a scattering cross section σ on the order of λ 2 , much larger than its physical size, as measured by the range of its potential. Very interesting phenomena can arise when two or more identical scatterers are placed close together, well within one wavelength. We show that, for a pair of identical scatterers, an extremely narrow p-wave open-quote open-quote proximity close-quote close-quote resonance develops from a broader s-wave resonance of the individual scatterers. A new s-wave resonance of the pair also appears. The relation of these proximity resonances (so called because they appear when the scatterers are close together) to the Thomas and Efimov effects is discussed. copyright 1996 The American Physical Society
Energy Technology Data Exchange (ETDEWEB)
Lutz, Matthias F.M., E-mail: m.lutz@gsi.de [GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Technische Universität Darmstadt, D-64289 Darmstadt (Germany); Lange, Jens Sören, E-mail: Soeren.Lange@exp2.physik.uni-giessen.de [II. Physikalisches Institut, Justus-Liebig-Universität Giessen, D-35392 Giessen (Germany); Pennington, Michael, E-mail: michaelp@jlab.org [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Bettoni, Diego [Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, 44122 Ferrara (Italy); Brambilla, Nora [Physik Department, Technische Universität München, D-85747 Garching (Germany); Crede, Volker [Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Eidelman, Simon [Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Budker Istitute of Nuclear Physics SB RAS, Novosibirsk 630090 (Russian Federation); Gillitzer, Albrecht [Institut für Kernphysik, Forschungszentrum Jülich GmbH, D-52425 Jülich (Germany); Gradl, Wolfgang [Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, D-55128 Mainz (Germany); Lang, Christian B. [Institut für Physik, Universität Graz, A-8010 Graz (Austria); Metag, Volker [II. Physikalisches Institut, Justus-Liebig-Universität Giessen, D-35392 Giessen (Germany); Nakano, Takashi [Research Center for Nuclear Physics, Osaka University, Osaka 567-0047 (Japan); and others
2016-04-15
We report on the EMMI Rapid Reaction Task Force meeting ‘Resonances in QCD’, which took place at GSI October 12–14, 2015. A group of 26 people met to discuss the physics of resonances in QCD. The aim of the meeting was defined by the following three key questions: • What is needed to understand the physics of resonances in QCD? • Where does QCD lead us to expect resonances with exotic quantum numbers? • What experimental efforts are required to arrive at a coherent picture? For light mesons and baryons only those with up, down and strange quark content were considered. For heavy–light and heavy–heavy meson systems, those with charm quarks were the focus. This document summarizes the discussions by the participants, which in turn led to the coherent conclusions we present here.
Magnetic resonance angiography (MRA)
International Nuclear Information System (INIS)
Arlart, I.P.; Guhl, L.
1992-01-01
An account is given in this paper of the physical and technical principles underlying the 'time-of-flight' technique for imaging of vessels by magnetic resonance tomography. Major indications for the new procedure of magnetic resonance angiography at present are intracerebral and extracerebral vessels, with digital subtraction angiography quite often being required to cope with minor alterations (small aneurysms, small occlusions). Magnetic resonance angiography and digital subtraction angiography are compared to each other for advantages and disadvantages. Basically, replacement of radiological angiography by magnetic resonance angiography appears to be possible only within limits, since X-ray diagnostics primarily provides morphological information about vessels, whereas flow dynamics is visualized by the 'time-of-flight' technique. (orig.) [de
Magnetic Resonance Cholangiopancreatography (MRCP)
... radio waves and a computer to evaluate the liver, gallbladder, bile ducts, pancreas and pancreatic duct for disease. It is ... of the hepatobiliary and pancreatic systems, including the liver, gallbladder, bile ducts, pancreas and pancreatic duct . Magnetic resonance imaging (MRI) ...
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...
Lattices of dielectric resonators
Trubin, Alexander
2016-01-01
This book provides the analytical theory of complex systems composed of a large number of high-Q dielectric resonators. Spherical and cylindrical dielectric resonators with inferior and also whispering gallery oscillations allocated in various lattices are considered. A new approach to S-matrix parameter calculations based on perturbation theory of Maxwell equations, developed for a number of high-Q dielectric bodies, is introduced. All physical relationships are obtained in analytical form and are suitable for further computations. Essential attention is given to a new unified formalism of the description of scattering processes. The general scattering task for coupled eigen oscillations of the whole system of dielectric resonators is described. The equations for the expansion coefficients are explained in an applicable way. The temporal Green functions for the dielectric resonator are presented. The scattering process of short pulses in dielectric filter structures, dielectric antennas and lattices of d...
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.
Accidental degeneracy of resonances
International Nuclear Information System (INIS)
Hernandez, E.; Mondragon, A.; Jauregui, A.
2001-01-01
Full text: It will be shown that a degeneracy of resonances is associated with a second rank pole in the scattering matrix and a Jordan cycle of generalized eigenfunctions of the radial Schrodinger equation. The generalized Gamow-Jordan eigenfunctions are basis elements of an expansion in complex resonance energy eigenfunctions. In this orthonormal basis, the Hamiltonian is represented by a non-diagonal complex matrix with a Jordan block of rank two. Some general properties of the degeneracy of resonances will be exhibited and discussed in an explicit example of degeneracy of resonant states and double poles in the scattering matrix of a double barrier potential. The cross section, scattering wave functions and Jordan-Gamow eigenfunctions are computed at degeneracy and their properties as functions of the control parameters of the system are discussed. (Author)
Resonant diphoton phenomenology simplified
International Nuclear Information System (INIS)
Panico, Giuliano; Vecchi, Luca; Wulzer, Andrea
2016-01-01
A framework is proposed to describe resonant diphoton phenomenology at hadron colliders in full generality. It can be employed for a comprehensive model-independent interpretation of the experimental data. Within the general framework, few benchmark scenarios are defined as representative of the various phenomenological options and/or of motivated new physics scenarios. Their usage is illustrated by performing a characterization of the 750 GeV excess, based on a recast of available experimental results. We also perform an assessment of which properties of the resonance could be inferred, after discovery, by a careful experimental study of the diphoton distributions. These include the spin J of the new particle and its dominant production mode. Partial information on its CP-parity can also be obtained, but only for J≥2. The complete determination of the resonance CP properties requires studying the pattern of the initial state radiation that accompanies the resonant diphoton production.
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.[...
Magnetic resonance angiography
... Saunders; 2015:chap 17. Litt H, Carpenter JP. Magnetic resonance imaging. In: Cronenwett JL, Johnston KW, eds. Rutherford's Vascular Surgery . 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap ...
International Nuclear Information System (INIS)
Ethier, R.; Melanson, D.; Peters, T.M.
1983-01-01
Ten years following computerized tomography, a new technique called nuclear magnetic resonance revolutionizes the field of diagnostic imaging. A major advantage of nuclear magnetic resonance is that the danger of radiation is non-existent as compared to computerized tomography. When parts of the human body are subject to radio-frequencies while in a fixed magnetic field, its most detailed structures are revealed. The quality of images, the applications, as well as the indications are forever increasing. Images obtained at the level of the brain and spinal cord through nuclear magnetic resonance supercede those obtained through computerized tomography. Hence, it is most likely that myelography, along with pneumoencephalography will be eliminated as a diagnostic means. It is without a doubt that nuclear magnetic resonance is tomorrow's computerized tomography [fr
Fabrication of nanoplate resonating structures via micro-masonry
International Nuclear Information System (INIS)
Bhaswara, A; Legrand, B; Mathieu, F; Nicu, L; Leichle, T; Keum, H; Rhee, S; Kim, S
2014-01-01
Advantages of using nanoscale membrane and plate resonators over more common cantilever shapes include higher quality factor (Q factor) for an equivalent mass and better suitability to mass sensing applications in fluid. Unfortunately, the current fabrication methods used to obtain such membranes and plates are limited in terms of materials and thickness range, and can potentially cause stiction. This study presents a new method to fabricate nanoplate resonating structures based on micro-masonry, which is the advanced form of the transfer printing technique. Nanoplate resonators were fabricated by transfer printing 0.34 µm thick square-shaped silicon plates by means of polydimethylsiloxane microtip stamps on top of silicon oxide base structures displaying 20 µm diameter cavities, followed by a thermal annealing step to create a rigid bond. Typical resulting suspended structures display vibration characteristics, i.e. a resonance frequency of a few MHz and Q factors above 10 in air at atmospheric pressure, which are in accordance with theory. Moreover, the presented fabrication method enables the realization of multiple suspended structures in a single step and on the same single base, without mechanical crosstalk between the resonators. This work thus demonstrates the suitability and the advantages of the micro-masonry technique for the fabrication of plate resonators for mass sensing purpose. (paper)
Design and fabrication of bandwidth tunable HTS transmit filter using {pi}-shaped waveguides
Energy Technology Data Exchange (ETDEWEB)
Sekiya, N., E-mail: nsekiya@yamanashi.ac.j [Department of Electrical Engineering, Yamanashi University, Nakagawa-Sekiya Laboratory, 4-3-11 Takeda, Kofu 400-8511 (Japan); Harada, H.; Nakagawa, Y. [Department of Electrical Engineering, Yamanashi University, Nakagawa-Sekiya Laboratory, 4-3-11 Takeda, Kofu 400-8511 (Japan); Ono, S.; Ohshima, S. [Yamagata University, 4-3-16 Johnan, Yonezawa 992-8510 (Japan)
2010-11-01
We have developed a method for tuning the bandwidth of a high-temperature superconducting (HTS) microstrip filter. Several {pi}-shaped waveguides are placed between the resonators, and the bandwidth is tuned in discrete steps by changing the switch states of the waveguides, which changes the coupling coefficient between the resonators. The filter contains 3-pole half-wavelength straight-line resonators and two {pi}-shaped waveguides for bandwidth tuning. It also has several electrical pads distributed around the feed lines for trimming after tuning. The filter was fabricated by depositing YBa{sub 2}Cu{sub 3}O{sub 7} thin film on an MgO substrate and has a measured center frequency of 5.17 GHz and bandwidth of 220 MHz. Use of the {pi}-shaped waveguides to adjust the coupling coefficients and the electrical pads to adjust the external quality factors resulted in 80-MHz bandwidth tuning without increased insertion loss.
International Nuclear Information System (INIS)
Robertson, Angus
1990-01-01
An assessment is made of the clinical benefits of expensive diagnostic technology, such as the magnetic resonance imaging. It is concluded that to most radiologists, magnetic resonance imaging has a definite place in the diagnostic scenario, especially for demonstrating central nervous system lesions in multiple sclerosis. While it is recognized that medical and financial resources are limited, it is emphasised that the cost to society must be balanced against the patient benefit. 17 refs
Comment on resonant absorption
International Nuclear Information System (INIS)
Hammerling, P.
1977-01-01
An average over angles of incidence of the usual resonant absorption function is presented. This form is appropriate under experimental conditions where the angles of incidence vary greatly and in an unknown manner. For comparison a lens-ellipsoidal mirror illumination system with a known longitudinal aberration is considered. In the latter example the angles of incidence are readily obtained and the resulting resonance absorption function evaluated. The associated fields are calculated in a similar fashion. (author)
Nuclear magnetic resonance gyroscope
International Nuclear Information System (INIS)
Grover, B.C.
1984-01-01
A nuclear magnetic resonance gyro using two nuclear magnetic resonance gases, preferably xenon 129 and xenon 131, together with two alkaline metal vapors, preferably rubidium, potassium or cesium, one of the two alkaline metal vapors being pumped by light which has the wavelength of that alkaline metal vapor, and the other alkaline vapor being illuminated by light which has the wavelength of that other alkaline vapor
Microwave Resonators and Filters
2015-12-22
1 Microwave Resonators and Filters Daniel E. Oates MIT Lincoln Laboratory 244 Wood St. Lexington, MA 02478 USA Email: oates@ll.mit.edu...explained in other chapters, the surface resistance of superconductors at microwave frequencies can be as much as three orders of magnitude lower than the...resonators and filters in the first edition of this handbook (Z.-Y. Shen 2003) discussed the then state of the art of microwave frequency applications
Resonance phenomena near thresholds
International Nuclear Information System (INIS)
Persson, E.; Mueller, M.; Rotter, I.; Technische Univ. Dresden
1995-12-01
The trapping effect is investigated close to the elastic threshold. The nucleus is described as an open quantum mechanical many-body system embedded in the continuum of decay channels. An ensemble of compound nucleus states with both discrete and resonance states is investigated in an energy-dependent formalism. It is shown that the discrete states can trap the resonance ones and also that the discrete states can directly influence the scattering cross section. (orig.)
Nuclear magnetic resonance imaging
International Nuclear Information System (INIS)
Young, I.R.
1984-01-01
In a method of imaging a body in which nuclear magnetic resonance is excited in a region including part of the body, and the free induction decay signal is measured, a known quantity of a material of known nuclear magnetic resonance properties, for example a bag of water, is included in the region so as to enhance the measured free induction decay signal. This then reduces the generation of noise during subsequent processing of the signal. (author)
Detecting hippocampal shape changes in Alzheimer's disease using statistical shape models
Shen, Kaikai; Bourgeat, Pierrick; Fripp, Jurgen; Meriaudeau, Fabrice; Salvado, Olivier
2011-03-01
The hippocampus is affected at an early stage in the development of Alzheimer's disease (AD). Using brain Magnetic Resonance (MR) images, we can investigate the effect of AD on the morphology of the hippocampus. Statistical shape models (SSM) are usually used to describe and model the hippocampal shape variations among the population. We use the shape variation from SSM as features to classify AD from normal control cases (NC). Conventional SSM uses principal component analysis (PCA) to compute the modes of variations among the population. Although these modes are representative of variations within the training data, they are not necessarily discriminant on labelled data. In this study, a Hotelling's T 2 test is used to qualify the landmarks which can be used for PCA. The resulting variation modes are used as predictors of AD from NC. The discrimination ability of these predictors is evaluated in terms of their classification performances using support vector machines (SVM). Using only landmarks statistically discriminant between AD and NC in SSM showed a better separation between AD and NC. These predictors also showed better correlation to the cognitive scores such as mini-mental state examination (MMSE) and Alzheimer's disease assessment scale (ADAS).
Influence of edge roughness on graphene nanoribbon resonant tunnelling diodes
International Nuclear Information System (INIS)
Liang Gengchiau; Khalid, Sharjeel Bin; Lam, Kai-Tak
2010-01-01
The edge roughness effects of graphene nanoribbons on their application in resonant tunnelling diodes with different geometrical shapes (S, H and W) were investigated. Sixty samples for each 5%, 10% and 15% edge roughness conditions of these differently shaped graphene nanoribbon resonant tunnelling diodes were randomly generated and studied. Firstly, it was observed that edge roughness in the barrier regions decreases the effective barrier height and thickness, which increases the broadening of the quantized states in the quantum well due to the enhanced penetration of the wave-function tail from the electrodes. Secondly, edge roughness increases the effective width of the quantum well and causes the lowering of the quantized states. Furthermore, the shape effects on carrier transport are modified by edge roughness due to different interfacial scattering. Finally, with the effects mentioned above, edge roughness has a considerable impact on the device performance in terms of varying the peak-current positions and degrading the peak-to-valley current ratio.
A numerical investigation of sub-wavelength resonances in polygonal metamaterial cylinders
DEFF Research Database (Denmark)
Arslanagic, Samel; Breinbjerg, Olav
2009-01-01
The sub-wavelength resonances, known to exist in metamaterial radiators and scatterers of circular cylindrical shape, are investigated with the aim of determining if these resonances also exist for polygonal cylinders and, if so, how they are affected by the shape of the polygon. To this end, a set...... of polygonal cylinders excited by a nearby electric line current is analyzed numerically and it is shown, through detailed analysis of the near-field distribution and radiation resistance, that these polygonal cylinders do indeed support sub-wavelength resonances similar to those of the circular cylinders...
Reconstruing U-Shaped Functions
Werker, Janet F.; Hall, D. Geoffrey; Fais, Laurel
2004-01-01
U-shaped developmental functions, and their N-shaped cousins, have intrigued developmental psychologists for decades because they provide a compelling demonstration that development does not always entail a monotonic increase across age in a single underlying ability. Instead, the causes of development are much more complex. Indeed,…
Resonant experience in emergent events of analysis
DEFF Research Database (Denmark)
Revsbæk, Line
2018-01-01
Theory, and the traditions of thought available and known to us, give shape to what we are able to notice of our field of inquiry, and so also of our practice of research. Building on G. H. Mead’s Philosophy of the Present (1932), this paper draws attention to ‘emergent events’ of analysis when...... in responsive relating to (case study) others is made generative as a dynamic in and of case study analysis. Using a case of being a newcomer (to research communities) researching newcomer innovation (of others), ‘resonant experience’ is illustrated as a heuristic in interview analysis to simultaneously...
Resonant driving of a nonlinear Hamiltonian system
International Nuclear Information System (INIS)
Palmisano, Carlo; Gervino, Gianpiero; Balma, Massimo; Devona, Dorina; Wimberger, Sandro
2013-01-01
As a proof of principle, we show how a classical nonlinear Hamiltonian system can be driven resonantly over reasonably long times by appropriately shaped pulses. To keep the parameter space reasonably small, we limit ourselves to a driving force which consists of periodic pulses additionally modulated by a sinusoidal function. The main observables are the average increase of kinetic energy and of the action variable (of the non-driven system) with time. Applications of our scheme aim for driving high frequencies of a nonlinear system with a fixed modulation signal.
Intrinsic Energy Dissipation Limits in Nano and Micromechanical Resonators
Iyer, Srikanth Subramanian
Resonant microelectromechanical Systems (MEMS) have enabled miniaturization of high-performance inertial sensors, radio-frequency filters, timing references and mass-based chemical sensors. Despite the increasing prevalence of MEMS resonators for these applications, the energy dissipation in these structures is not well-understood. Accurate prediction of the energy loss and the resulting quality factor (Q) has significant design implications because it is directly related to device performance metrics including sensitivity for resonant sensors, bandwidth for radio-frequency filters and phase-noise for timing references. In order to assess the future potential for MEMS resonators it is critically important to evaluate the energy dissipation limits, which will dictate the ultimate performance resonant MEMS devices can achieve. This work focuses on the derivation and evaluation of the intrinsic mechanical energy dissipation limit for single-crystal nano and micromechanical resonators due to anharmonic phonon-phonon scattering in the Akhiezer regime. The energy loss is derived using perturbation theory and the linearized Boltzmann transport equation for phonons, and includes the direction and polarization dependent mode-Gruneisen parameters in order to capture the strain-induced anharmonicity among phonon branches. Evaluation of the quality factor limit reveals that Akhiezer damping, previously thought to depend only on material properties, has a strong dependence on crystal orientation and resonant mode shape. The robust model provides a dissipation limit for all resonant modes including shear-mode vibrations, which have significantly reduced energy loss because dissipative phonon-phonon scattering is restricted to volume-preserving phonon branches, indicating that Lame or wine-glass mode resonators will have the highest upper limit on mechanical efficiency. Finally, the analytical dissipation model is integrated with commercial finite element software in order to
Functional and shape data analysis
Srivastava, Anuj
2016-01-01
This textbook for courses on function data analysis and shape data analysis describes how to define, compare, and mathematically represent shapes, with a focus on statistical modeling and inference. It is aimed at graduate students in analysis in statistics, engineering, applied mathematics, neuroscience, biology, bioinformatics, and other related areas. The interdisciplinary nature of the broad range of ideas covered—from introductory theory to algorithmic implementations and some statistical case studies—is meant to familiarize graduate students with an array of tools that are relevant in developing computational solutions for shape and related analyses. These tools, gleaned from geometry, algebra, statistics, and computational science, are traditionally scattered across different courses, departments, and disciplines; Functional and Shape Data Analysis offers a unified, comprehensive solution by integrating the registration problem into shape analysis, better preparing graduate students for handling fu...
Parity horizons in shape dynamics
International Nuclear Information System (INIS)
Herczeg, Gabriel
2016-01-01
I introduce the notion of a parity horizon, and show that many simple solutions of shape dynamics possess them. I show that the event horizons of the known asymptotically flat black hole solutions of shape dynamics are parity horizons and that this notion of parity implies that these horizons possess a notion of CPT invariance that can in some cases be extended to the solution as a whole. I present three new solutions of shape dynamics with parity horizons and find that not only do event horizons become parity horizons in shape dynamics, but observer-dependent horizons and Cauchy horizons do as well. The fact that Cauchy horizons become (singular) parity horizons suggests a general chronology protection mechanism in shape dynamics that prevents the formation of closed timelike curves. (paper)
Shape coexistence in selenium isotopes
International Nuclear Information System (INIS)
Liu Ying; Cao Zhongbin; Xu Furong
2010-01-01
Nuclear shape change and shape coexistence in the Selenium isotopes have been investigated by Total-Routhian-Surface (TRS) calculations. It is found that nuclear shapes vary significantly with increasing neutron number. The TRS calculations for the ground states of 66,72,92,94 Se isotopes show that both neutron-deficient and neutron-dripline Selenium isotopes have oblate and prolate shape coexistence. The cranking shell-model calculations for 72,94 Se give that prolate and oblate shape coexistence in low rotational frequency. However, oblate rotational bands disappear and prolate rotational bands become yrast bands with increasing rotational frequency, which is due to the intrusion of the g 9/2 orbitals. (authors)
Determination of edge plasma parameters by a genetic algorithm analysis of spectral line shapes
International Nuclear Information System (INIS)
Marandet, Y.; Genesio, P.; Godbert-Mouret, L.; Koubiti, M.; Stamm, R.; Capes, H.; Guirlet, R.
2003-01-01
Comparing an experimental and a theoretical line shape can be achieved by a genetic algorithm (GA) based on an analogy to the mechanisms of natural selection. Such an algorithm is able to deal with complex non-linear models, and can avoid local minima. We have used this optimization tool in the context of edge plasma spectroscopy, for a determination of the temperatures and fractions of the various populations of neutral deuterium emitting the D α line in 2 configurations of Tore-Supra: ergodic divertor and toroidal pumped limiter. Using the GA fit, the neutral emitters are separated into up to 4 populations which can be identified as resulting from molecular dissociation reactions, charge exchange, or reflection. In all the edge plasmas studied, a significant fraction of neutrals emit in the line wings, leading to neutrals with a temperature up to a few hundreds eV if a Gaussian line shape is assumed. This conclusion could be modified if the line wing exhibits a non Gaussian behavior
Li7(BH)5(+): a new thermodynamically favored star-shaped molecule.
Torres-Vega, Juan J; Vásquez-Espinal, Alejandro; Beltran, Maria J; Ruiz, Lina; Islas, Rafael; Tiznado, William
2015-07-15
The potential energy surfaces (PESs) of Lin(BH)5(n-6) systems (where n = 5, 6, and 7) were explored using the gradient embedded genetic algorithm (GEGA) program, in order to find their global minima conformations. This search predicts that the lowest-energy isomers of Li6(BH)5 and Li7(BH)5(+) contain a (BH)5(6-) pentagonal fragment, which is isoelectronic and structurally analogous to the prototypical aromatic hydrocarbon anion C5H5(-). Li7(BH)5(+), along with Li7C5(+), Li7Si5(+) and Li7Ge5(+), joins a select group of clusters that adopt a seven-peak star-shape geometry, which is favored by aromaticity in the central five-membered ring, and by the preference of Li atoms for bridging positions. The theoretical analysis of chemical bonding, based on magnetic criteria, supports the notion that electronic delocalization is an important stabilization factor in all these star-shaped clusters.
Determination of edge plasma parameters by a genetic algorithm analysis of spectral line shapes
Energy Technology Data Exchange (ETDEWEB)
Marandet, Y.; Genesio, P.; Godbert-Mouret, L.; Koubiti, M.; Stamm, R. [Universite de Provence (PIIM), Centre de Saint-Jerome, 13 - Marseille (France); Capes, H.; Guirlet, R. [Association Euratom-CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee
2003-07-01
Comparing an experimental and a theoretical line shape can be achieved by a genetic algorithm (GA) based on an analogy to the mechanisms of natural selection. Such an algorithm is able to deal with complex non-linear models, and can avoid local minima. We have used this optimization tool in the context of edge plasma spectroscopy, for a determination of the temperatures and fractions of the various populations of neutral deuterium emitting the D{sub {alpha}} line in 2 configurations of Tore-Supra: ergodic divertor and toroidal pumped limiter. Using the GA fit, the neutral emitters are separated into up to 4 populations which can be identified as resulting from molecular dissociation reactions, charge exchange, or reflection. In all the edge plasmas studied, a significant fraction of neutrals emit in the line wings, leading to neutrals with a temperature up to a few hundreds eV if a Gaussian line shape is assumed. This conclusion could be modified if the line wing exhibits a non Gaussian behavior.
The role of spin-orbit potential in nuclear prolate-shape dominance
Energy Technology Data Exchange (ETDEWEB)
Takahara, Satoshi, E-mail: staka@ks.kyorin-u.ac.jp [Kyorin University, School of Medicine, Mitaka, Tokyo 181-8611 (Japan); Onishi, Naoki [University of Tokyo (Japan); University of Yamanashi (Japan); Shimizu, Yoshifumi R. [Department of Physics, Graduate School of Science, Kyushu University, Fukuoka 812-8581 (Japan); Tajima, Naoki [Department of Applied Physics, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507 (Japan)
2011-08-26
It is confirmed, in terms of the Woods-Saxon-Strutinsky method, that the spin-orbit potential plays a decisive role in the predominance of prolate deformation, which has been a long standing problem in nuclear physics. It is originated from the combined effects of the spin-orbit coupling and the diffused surface of the potential, in agreement with the previous work based on a more schematic Nilsson-Strutinsky method. The degree of prolate-shape dominance exhibits an oscillatory behavior with respect to the strength of spin-orbit potential and, the prolate-shape dominance is realized at the proper strength of the spin-orbit potential together with the standard surface diffuseness; this oscillatory behavior disappears in case of small diffuseness corresponding to ellipsoidal cavity. The calculated energy differences between oblate and prolate minima in this Letter are consistent with those of our extensive self-consistent calculations of the Hartree-Fock + BCS method with the Skyrme interaction.
The role of spin-orbit potential in nuclear prolate-shape dominance
International Nuclear Information System (INIS)
Takahara, Satoshi; Onishi, Naoki; Shimizu, Yoshifumi R.; Tajima, Naoki
2011-01-01
It is confirmed, in terms of the Woods-Saxon-Strutinsky method, that the spin-orbit potential plays a decisive role in the predominance of prolate deformation, which has been a long standing problem in nuclear physics. It is originated from the combined effects of the spin-orbit coupling and the diffused surface of the potential, in agreement with the previous work based on a more schematic Nilsson-Strutinsky method. The degree of prolate-shape dominance exhibits an oscillatory behavior with respect to the strength of spin-orbit potential and, the prolate-shape dominance is realized at the proper strength of the spin-orbit potential together with the standard surface diffuseness; this oscillatory behavior disappears in case of small diffuseness corresponding to ellipsoidal cavity. The calculated energy differences between oblate and prolate minima in this Letter are consistent with those of our extensive self-consistent calculations of the Hartree-Fock + BCS method with the Skyrme interaction.
Resonance probe; La sonde a resonance
Energy Technology Data Exchange (ETDEWEB)
Lepechinsky, D; Messiaen, A; Rolland, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires
1966-07-01
After a brief review of papers recently published on the resonance probe as a tool for plasma diagnostics, the main features of the theory proposed by one of us are recalled. In this theory the geometry of the resonator formed by the probe, the ion sheath and the plasma is explicitly taken into account with the quasi-static and cold plasma approximations. Some new results emerging from this theory are indicated and a comparison with experimental data obtained with a spherical probe placed in a quiescent mercury-vapour plasma is made. A good quantitative agreement has been observed, indicating that the theory is satisfactory and justifying the assumptions involved. Nevertheless it appears that in some cases experimental results can only be interpreted when non collisional damping phenomena are taken into consideration. (author) [French] Apres un apercu des etudes recemment publiees sur la sonde a resonance pour le diagnostic des plasmas, on rappelle l'essentiel de la theorie proposee par l'un de nous ou il est tenu compte explicitement de la geometrie du resonateur forme par le systeme sonde-gaine ionique-plasma dans l'approximation quasi-statique et du plasma froid. On indique quelques resultats nouveaux pouvant etre tires de cette theorie et on la confronte avec les donnees experimentales obtenues pour une sonde spherique placee dans un plasma de mercure en equilibre. Un tres bon accord quantitatif a ete constate, indiquant que la theorie est satisfaisante et justifiant les approximations faites dans celle-ci. Il apparait toutefois que certains resultats experimentaux ne peuvent etre interpretes qu'en tenant compte des phenomenes d'amortissement non collisionnels. (auteur)
HTS microstrip disk resonator with an upper dielectric layer for 4GHz
International Nuclear Information System (INIS)
Yamanaka, Kazunori; Kai, Manabu; Akasegawa, Akihiko; Nakanishi, Teru
2006-01-01
We propose HTS microstrip disk resonator with an upper dielectric layer as a candidate resonator structure of HTS compact power filter for 4GHz band. The electromagnetic simulations on the upper dielectric layer examined the current distributions of the HTS resonators that had TM 11 mode resonance of about 4 GHz. By the simulations, it is evaluated that of the maximum current density near the end portion of the disk-shape pattern of the resonator with the thick upper-layered structure decreases by roughly 30-50 percent, as compared with that of the resonator without it. Then, we designed and fabricated the resonator samples with and without the upper dielectrics. The RF power measurement results indicated that the upper dielectric layer leads to an increase in handling power
Maxima and Minima in Fuzzified Linear Orderings
Czech Academy of Sciences Publication Activity Database
Běhounek, Libor
2016-01-01
Roč. 289, 15 April (2016), s. 82-93 ISSN 0165-0114 R&D Projects: GA ČR GPP103/10/P234; GA MŠk ED1.1.00/02.0070 Grant - others:GA MŠk(CZ) EE2.3.30.0010 Institutional support: RVO:67985807 Keywords : fuzzy relations * similarity relations * fuzzy orderings * higher-order fuzzy logic Subject RIV: BA - General Mathematics Impact factor: 2.718, year: 2016
Sails and norm minima of lattices
International Nuclear Information System (INIS)
German, O N
2005-01-01
It is known that a real number is badly approximable if and only if its partial quotients are uniformly bounded. In this paper an analogous assertion is proved for the so-called sails, which is one of the most natural multidimensional generalizations of continued fractions.
Resonant enhancement in leptogenesis
Dev, P. S. B.; Garny, M.; Klaric, J.; Millington, P.; Teresi, D.
2018-02-01
Vanilla leptogenesis within the type I seesaw framework requires the mass scale of the right-handed neutrinos to be above 109 GeV. This lower bound can be avoided if at least two of the sterile states are almost mass degenerate, which leads to an enhancement of the decay asymmetry. Leptogenesis models that can be tested in current and upcoming experiments often rely on this resonant enhancement, and a systematic and consistent description is therefore necessary for phenomenological applications. In this paper, we give an overview of different methods that have been used to study the saturation of the resonant enhancement when the mass difference becomes comparable to the characteristic width of the Majorana neutrinos. In this limit, coherent flavor transitions start to play a decisive role, and off-diagonal correlations in flavor space have to be taken into account. We compare various formalisms that have been used to describe the resonant regime and discuss under which circumstances the resonant enhancement can be captured by simplified expressions for the CP asymmetry. Finally, we briefly review some of the phenomenological aspects of resonant leptogenesis.
Resonant ultrasound spectrometer
Migliori, Albert; Visscher, William M.; Fisk, Zachary
1990-01-01
An ultrasound resonant spectrometer determines the resonant frequency spectrum of a rectangular parallelepiped sample of a high dissipation material over an expected resonant response frequency range. A sample holder structure grips corners of the sample between piezoelectric drive and receive transducers. Each transducer is mounted on a membrane for only weakly coupling the transducer to the holder structure and operatively contacts a material effective to remove system resonant responses at the transducer from the expected response range. i.e., either a material such as diamond to move the response frequencies above the range or a damping powder to preclude response within the range. A square-law detector amplifier receives the response signal and retransmits the signal on an isolated shield of connecting cabling to remove cabling capacitive effects. The amplifier also provides a substantially frequency independently voltage divider with the receive transducer. The spectrometer is extremely sensitive to enable low amplitude resonance to be detected for use in calculating the elastic constants of the high dissipation sample.
Electrothermally Tunable Arch Resonator
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
A theory of shape identification
Cao, Frédéric; Morel, Jean-Michel; Musé, Pablo; Sur, Frédéric
2008-01-01
Recent years have seen dramatic progress in shape recognition algorithms applied to ever-growing image databases. They have been applied to image stitching, stereo vision, image mosaics, solid object recognition and video or web image retrieval. More fundamentally, the ability of humans and animals to detect and recognize shapes is one of the enigmas of perception. The book describes a complete method that starts from a query image and an image database and yields a list of the images in the database containing shapes present in the query image. A false alarm number is associated to each detection. Many experiments will show that familiar simple shapes or images can reliably be identified with false alarm numbers ranging from 10-5 to less than 10-300. Technically speaking, there are two main issues. The first is extracting invariant shape descriptors from digital images. The second is deciding whether two shape descriptors are identifiable as the same shape or not. A perceptual principle, the Helmholtz princi...
Lu, Lehui; Ai, Kelong; Ozaki, Yukihiro
2008-02-05
We report a facile and environmentally friendly strategy for high-yield synthesis of highly monodisperse gold nanoparticles with urchin-like shape. A simple protein, gelatin, was first used for the control over shape and orientation of the gold nanoparticles. These nanoparticles, ready to use for biological systems, are promising in the optical imaging-based disease diagnostics and therapy because of their tunable surface plasmon resonance (SPR) and excellent surface-enhanced Raman scattering (SERS) activity.
Garland, G D; Wilson, J T
2013-01-01
The Earth's Shape and Gravity focuses on the progress of the use of geophysical methods in investigating the interior of the earth and its shape. The publication first offers information on gravity, geophysics, geodesy, and geology and gravity measurements. Discussions focus on gravity measurements and reductions, potential and equipotential surfaces, absolute and relative measurements, and gravity networks. The text then elaborates on the shape of the sea-level surface and reduction of gravity observations. The text takes a look at gravity anomalies and structures in the earth's crust; interp
Wu, Jiayang; Moein, Tania; Xu, Xingyuan; Moss, David J.
2018-04-01
We demonstrate advanced integrated photonic filters in silicon-on-insulator (SOI) nanowires implemented by cascaded Sagnac loop reflector (CSLR) resonators. We investigate mode splitting in these standing-wave (SW) resonators and demonstrate its use for engineering the spectral profile of on-chip photonic filters. By changing the reflectivity of the Sagnac loop reflectors (SLRs) and the phase shifts along the connecting waveguides, we tailor mode splitting in the CSLR resonators to achieve a wide range of filter shapes for diverse applications including enhanced light trapping, flat-top filtering, Q factor enhancement, and signal reshaping. We present the theoretical designs and compare the CSLR resonators with three, four, and eight SLRs fabricated in SOI. We achieve versatile filter shapes in the measured transmission spectra via diverse mode splitting that agree well with theory. This work confirms the effectiveness of using CSLR resonators as integrated multi-functional SW filters for flexible spectral engineering.
Directory of Open Access Journals (Sweden)
Jiayang Wu
2018-04-01
Full Text Available We demonstrate advanced integrated photonic filters in silicon-on-insulator (SOI nanowires implemented by cascaded Sagnac loop reflector (CSLR resonators. We investigate mode splitting in these standing-wave (SW resonators and demonstrate its use for engineering the spectral profile of on-chip photonic filters. By changing the reflectivity of the Sagnac loop reflectors (SLRs and the phase shifts along the connecting waveguides, we tailor mode splitting in the CSLR resonators to achieve a wide range of filter shapes for diverse applications including enhanced light trapping, flat-top filtering, Q factor enhancement, and signal reshaping. We present the theoretical designs and compare the CSLR resonators with three, four, and eight SLRs fabricated in SOI. We achieve versatile filter shapes in the measured transmission spectra via diverse mode splitting that agree well with theory. This work confirms the effectiveness of using CSLR resonators as integrated multi-functional SW filters for flexible spectral engineering.
Josephson junctions array resonators
Energy Technology Data Exchange (ETDEWEB)
Gargiulo, Oscar; Muppalla, Phani; Mirzaei, Iman; Kirchmair, Gerhard [Institute for Quantum Optics and Quantum Information, Innsbruck (Austria)
2016-07-01
We present an experimental analysis of the self- and cross-Kerr effect of extended plasma resonances in Josephson junction chains. The chain consists of 1600 individual junctions and we can measure quality factors in excess of 10000. The Kerr effect manifests itself as a frequency shift that depends linearly on the number of photons in a resonant mode. By changing the input power we are able to measure this frequency shift on a single mode (self-kerr). By changing the input power on another mode while measuring the same one, we are able to evaluate the cross-kerr effect. We can measure the cross-Kerr effect by probing the resonance frequency of one mode while exciting another mode of the array with a microwave drive.
Electrothermally Tunable Bridge Resonator
Hajjaj, Amal Z.; Alcheikh, Nouha; Ramini, Abdallah; Hafiz, Md Abdullah Al; Younis, Mohammad I.
2016-01-01
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.
Electrothermally Tunable Bridge Resonator
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.
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.)
A DOUBLE E SHAPED MICROSTRIP PATCH ANTENNA FOR MULTIBAND APPLICATIONS
Directory of Open Access Journals (Sweden)
Pristin K Mathew
2014-06-01
Full Text Available This paper presents a dual band Compact double E shaped Microstrip Patch antenna with enhanced gain for Worldwide Interoperability for Microwave Access (WI-MAX, Universal Mobile Telecommunication Systems (UMTS and Satellite applications. The modified E shaped patch antenna is designed using CADFEKO and the results of return loss, Voltage Standing Wave Ratio (VSWR, gain of the proposed antenna are compared with a conventional E shaped patch antenna. The results show that the double E shaped wideband patch antenna has an impedance bandwidth of 10.7 % with a return loss of -13.6dB, -12.4 dB, -12.1dB and -14.2dB at resonant frequencies of 1.96 GHz, 3.62 GHz, 5.76 GHz and 6.82 GHz, whereas a conventional E shaped patch antenna operates at 2.5 GHz, 3.4 GHz and 5.5 GHz with a return loss of -16 dB each and impedance bandwidth of 10.6 %. Both the antennas uses Coaxial Probe feeding technique and Flame Retardant 4 (FR-4 as the substrate material with a thickness of 2.87 mm. A parametric study has been done so as to understand the effect of each parameter to obtain a better performance and optimised results.
Augmented Endoscopic Images Overlaying Shape Changes in Bone Cutting Procedures.
Nakao, Megumi; Endo, Shota; Nakao, Shinichi; Yoshida, Munehito; Matsuda, Tetsuya
2016-01-01
In microendoscopic discectomy for spinal disorders, bone cutting procedures are performed in tight spaces while observing a small portion of the target structures. Although optical tracking systems are able to measure the tip of the surgical tool during surgery, the poor shape information available during surgery makes accurate cutting difficult, even if preoperative computed tomography and magnetic resonance images are used for reference. Shape estimation and visualization of the target structures are essential for accurate cutting. However, time-varying shape changes during cutting procedures are still challenging issues for intraoperative navigation. This paper introduces a concept of endoscopic image augmentation that overlays shape changes to support bone cutting procedures. This framework handles the history of the location of the measured drill tip as a volume label and visualizes the remains to be cut overlaid on the endoscopic image in real time. A cutting experiment was performed with volunteers, and the feasibility of this concept was examined using a clinical navigation system. The efficacy of the cutting aid was evaluated with respect to the shape similarity, total moved distance of a cutting tool, and required cutting time. The results of the experiments showed that cutting performance was significantly improved by the proposed framework.
Magnetic resonance annual, 1988
International Nuclear Information System (INIS)
Kressel, H.Y.
1987-01-01
This book features reviews of high-resolution MRI of the knee, MRI of the normal and ischmeic hip, MRI of the heart, and temporomandibular joint imaging, as well as thorough discussion on artifacts in magnetic resonance imaging. Contributors consider the clinical applications of gadolinium-DTPA in magnetic resonance imaging and the clinical use of partial saturation and saturation recovery sequences. Timely reports assess the current status of rapid MRI and describe a new rapid gated cine MRI technique. Also included is an analysis of cerebrospinal fluid flow effects during MRI of the central nervous system
International Nuclear Information System (INIS)
Snover, K.A.
1989-01-01
Giant nuclear resonances are elementary mods of oscillation of the whole nucleus, closely related to the normal modes of oscillation of coupled mechanical systems. They occur systematically in most if not all nuclei, with oscillation energies typically in the range 10-30 MeV. One of the best - known examples is the giant electric dipole (El) resonance, in which all the protons and all the neutrons oscillate with opposite phase, producing a large time - varying electric dipole moment which acts as an effective antenna for radiating gamma ray. This paper discusses this mode as well as quadrupole and monopole modes
Nanoantenna using mechanical resonance
Chang Hwa Lee,
2010-11-01
Nanoantenna using mechanical resonance vibration is made from an indium tin oxide (ITO) coated vertically aligned nanorod array. Only this structure works as a radio with demodulator without any electrical circuit using field emission phenomenon. A top-down fabrication method of an ITO coated nanorod array is proposed using a modified UV lithography. The received radio frequency and the resonance frequency of nanoantenna can be controlled by the fabrication condition through the height of a nanorod array. The modulated signals are received successfully with the transmission carrier wave frequency (248MHz) and the proposed nanoantenna is expected to be used in communication system for ultra small scale sensor. ©2010 IEEE.
International Nuclear Information System (INIS)
Aguiar, F.M. de
2011-01-01
The Helmholtz equation describing transverse magnetic modes in a closed flat microwave resonator with 60 randomly distributed discs is numerically solved. At lower frequencies, the calculated wave intensity spatially distributed obeys the universal Porter-Thomas form if localized modes are excluded. A superposition of resonant modes is shown to lead to rare events of extreme intensities (freak waves) at localized 'hot spots'. The temporally distributed intensity of such a superposition at the center of a hot spot also follows the Porter-Thomas form. Branched modes are found at higher frequencies. The results bear resemblance to recent experiments reported in an open cavity.
Browning, David
2000-04-01
When force is applied by an athlete to sports equipment resonances can occur. Just a few examples are: the ringing of a spiked volleyball, the strumming of a golf club shaft during a swing, and multiple modes induced in an aluminum baseball bat when striking a ball. Resonances produce acoustic waves which, if conditions are favorable, can be detected off the playing field. This can provide a means to evaluate athletic performance during game conditions. Results are given from the use of a simple hand-held acoustic detector - by a spectator sitting in the stands - to determine how hard volleyballs were spiked during college and high school games.
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.
International Nuclear Information System (INIS)
Shimizu, Isao; Fujii, Taketsugu
1995-01-01
It has been desired to eliminate or collect the contamination particles of radioisotope in each sort of species or shape and size non-invasively. The shape and size of particle can be determined from the shape and distribution of diffraction pattern of particle in the parallel laser beam, the species of particle can be discriminated by the fluorescence from resonance of laser beam, or by the laser Raman scattering, and the particle suspended in the air or falling down in a vacuum can be levitated against the gravity and trapped by the radiation force and the trapping force of the focussed laser beam in the atmosphere or in a vacuum. For the purpose of the non-invasive manipulation of contamination particles, the laser manipulation technique, image processing technique with Multiplexed Matched Spatial Filter and the determination technique of laser Raman scattering or fluorescence from resonance of laser light were combined in the experiments. The shape, size and species of particles trapped in the focal plane of focused Ar laser beam can be determined simultaneously and instantaneously from the shape and intensity distributions of diffraction patterns of the particles in the irradiation of parallel coherent beam of He-Ne laser, and fluorescence from the resonance of YAG laser beam with variable wave length. In this research, a new technique is proposed to manipulate non-invasively the contamination particles determined with the shape, size and species in the atmosphere or in a vacuum, by laser beam. (author)
Thermal and particle size distribution effects on the ferromagnetic resonance in magnetic fluids
International Nuclear Information System (INIS)
Marin, C.N.
2006-01-01
Thermal and particle size distribution effects on the ferromagnetic resonance of magnetic fluids were theoretically investigated, assuming negligible interparticle interactions and neglecting the viscosity of the carrier liquid. The model is based on the usual approach for the ferromagnetic resonance description of single-domain magnetic particle systems, which was amended in order to take into account the finite particle size effect, the particle size distribution and the orientation mobility of the particles within the magnetic fluid. Under these circumstances the shape of the resonance line, the resonance field and the line width are found to be strongly affected by the temperature and by the particle size distribution of magnetic fluids
International Nuclear Information System (INIS)
Dey, Gautam; Sarkar, S.; Chakraborty, A.; Krishichayan; Ghugre, S.S.; Sinha, A.K.; Kshetri, Ritesh; Ray, I.; Ganguly, S.; Pradhan, M.K.; Raut, R.; Goswami, A.; Banerjee, P.; Mukherjee, A.; Bhattacharya, S.; Saha Sarkar, S.; Ray Basu, M.; Ganguly, G.; Ray, M.; Basu, S.K.
2006-01-01
The motivation for the present work are to firmly assign spins and parities of the excited levels and to investigate shape evolution in 153 Ho as expected phenomenologically from the level spectra and feeding patterns
Pairwise harmonics for shape analysis
Zheng, Youyi; Tai, Chiewlan; Zhang, Eugene; Xu, Pengfei
2013-01-01
efficient algorithms than the state-of-the-art methods for three applications: intrinsic reflectional symmetry axis computation, matching shape extremities, and simultaneous surface segmentation and skeletonization. © 2012 IEEE.