WorldWideScience

Sample records for circular intensity differential

  1. Circular Intensity Differential Scattering of chiral molecules

    Energy Technology Data Exchange (ETDEWEB)

    Bustamante, C.J.

    1980-12-01

    In this thesis a theory of the Circular Intensity Differential Scattering (CIDS) of chiral molecules as modelled by a helix oriented with respect to the direction of incidence of light is presented. It is shown that a necessary condition for the existence of CIDS is the presence of an asymmetric polarizability in the scatterer. The polarizability of the scatterer is assumed generally complex, so that both refractive and absorptive phenomena are taken into account.

  2. High intensity circular proton accelerators

    International Nuclear Information System (INIS)

    Circular machines suitable for the acceleration of high intensity proton beams include cyclotrons, FFAG accelerators, and strong-focusing synchrotrons. This paper discusses considerations affecting the design of such machines for high intensity, especially space charge effects and the role of beam brightness in multistage accelerators. Current plans for building a new generation of high intensity 'kaon factories' are reviewed. 47 refs

  3. Circular intensity differential scattering (CIDS) measurements in the soft x-ray region of the spectrum (@16 eV to 500 eV)

    Energy Technology Data Exchange (ETDEWEB)

    Maestre, M.F. (Lawrence Berkeley Lab., CA (United States)); Bustamante, C. (Oregon Univ., Eugene, OR (United States). Dept. of Chemistry); Snyder, P. (Florida Atlantic Univ., Boca Raton, FL (United States). Dept. of Chemistry); Rowe, E.; Hansen, R. (Wisconsin Univ., Stoughton, WI (United States). Synchrotron Radiation Center)

    1991-03-01

    We propose the use of recently developed techniques of circular intensity differential scattering (CIDS), as extended to the soft x-ray region of the spectrum (16 eV to 500 eV), to study the higher order organization of the eukaryotic chromosome. CIDS is the difference in scattering power of an object when illuminated by right circularly polarized vs. left circularly polarized electromagnetic radiation of arbitrary wavelength. CIDS has been shown to be a very sensitive measure of the helical organization of the scattering object eg. the eukaryotic chromosome. Preliminary results of measurements of samples of bacteriophages and octopus sperm done at SRC, Wisconsin, show the technique to be very sensitive to the dimensional parameters of the particles interrogated by circularly polarized light. 7 refs., 5 figs.

  4. Design of circular differential microphone arrays

    CERN Document Server

    Benesty, Jacob; Cohen, Israel

    2015-01-01

    Recently, we proposed a completely novel and efficient way to design differential beamforming algorithms for linear microphone arrays. Thanks to this very flexible approach, any order of differential arrays can be designed. Moreover, they can be made robust against white noise amplification, which is the main inconvenience in these types of arrays. The other well-known problem with linear arrays is that electronic steering is not really feasible.  In this book, we extend all these fundamental ideas to circular microphone arrays and show that we can design small and compact differential arrays of any order that can be electronically steered in many different directions and offer a good degree of control of the white noise amplification problem, high directional gain, and frequency-independent response. We also present a number of practical examples, demonstrating that differential beamforming with circular microphone arrays is likely one of the best candidates for applications involving speech enhancement (i....

  5. Total and Differential Efficiencies for a Circular Detector Viewing a Circular Radiator of Finite Thickness

    International Nuclear Information System (INIS)

    Total and differential detection efficiencies have been computed for a circular detector viewing a circular radiator of finite thickness. Isotropic, cosines and n-p scattering angular emission distributions of the radiated particles are considered. Tables are given for the total efficiencies as well as for the differential efficiencies in the n-p scattering case

  6. Scaled, circular-emitter Penning SPS for intense H- beams

    International Nuclear Information System (INIS)

    The Los Alamos versions of the Penning Surface-Plasma Source (SPS) routinely generate H- ion beams with pulsed currents over 100 mA. However, these sources employ geometries that result in the extraction of slit beams (0.5 x 10 mm2). Our modeling with the SNOW code indicates that the beam from a 5.4-mm-diam circular emitter will have lower emittance and divergence for transport to and injection into our radio-frequency quadrupole (RFQ) accelerator. This paper describes a newly constructed Penning SPS that has most of its discharge chamber dimensions scaled up by a factor of 4 to accommodate this circular emitter

  7. Generation of circularly polarized attosecond pulses by intense ultrashort laser pulses from extended asymmetric molecular ions

    Science.gov (United States)

    Yuan, Kai-Jun; Bandrauk, André D.

    2011-08-01

    We present a method for generation of single circularly polarized attosecond pulses in extended asymmetric HHe2+ molecular ions. By employing an intense ultrashort circularly polarized laser pulse with intensity 4.0×1014 W/cm2, wavelength 400 nm, and duration 10 optical cycles, molecular high-order-harmonic generation (MHOHG) spectra with multiple plateaus exhibit characters of circular polarization. Using a classical laser-induced collision model, double collisions of continuum electrons first with neighboring ions and then second with parent ions are presented at a particular internuclear distance and confirmed from numerical solutions of a time-dependent Schrödinger equation. We analyze the MHOHG spectra with a Gabor time window and find that, due to the asymmetry of HHe2+, a single collision trajectory of continuum electrons with ions can produce circularly polarized harmonics, leading to single circularly polarized attosecond pulses for specific internuclear distances.

  8. Generation of circularly polarized attosecond pulses by intense ultrashort laser pulses from extended asymmetric molecular ions

    International Nuclear Information System (INIS)

    We present a method for generation of single circularly polarized attosecond pulses in extended asymmetric HHe2+ molecular ions. By employing an intense ultrashort circularly polarized laser pulse with intensity 4.0x1014 W/cm2, wavelength 400 nm, and duration 10 optical cycles, molecular high-order-harmonic generation (MHOHG) spectra with multiple plateaus exhibit characters of circular polarization. Using a classical laser-induced collision model, double collisions of continuum electrons first with neighboring ions and then second with parent ions are presented at a particular internuclear distance and confirmed from numerical solutions of a time-dependent Schroedinger equation. We analyze the MHOHG spectra with a Gabor time window and find that, due to the asymmetry of HHe2+, a single collision trajectory of continuum electrons with ions can produce circularly polarized harmonics, leading to single circularly polarized attosecond pulses for specific internuclear distances.

  9. Generation of circularly polarized attosecond pulses by intense ultrashort laser pulses from extended asymmetric molecular ions

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Kai-Jun; Bandrauk, Andre D. [Laboratoire de Chimie Theorique, Faculte des Sciences, Universite de Sherbrooke, Sherbrooke, Quebec, J1K 2R1 (Canada)

    2011-08-15

    We present a method for generation of single circularly polarized attosecond pulses in extended asymmetric HHe{sup 2+} molecular ions. By employing an intense ultrashort circularly polarized laser pulse with intensity 4.0x10{sup 14} W/cm{sup 2}, wavelength 400 nm, and duration 10 optical cycles, molecular high-order-harmonic generation (MHOHG) spectra with multiple plateaus exhibit characters of circular polarization. Using a classical laser-induced collision model, double collisions of continuum electrons first with neighboring ions and then second with parent ions are presented at a particular internuclear distance and confirmed from numerical solutions of a time-dependent Schroedinger equation. We analyze the MHOHG spectra with a Gabor time window and find that, due to the asymmetry of HHe{sup 2+}, a single collision trajectory of continuum electrons with ions can produce circularly polarized harmonics, leading to single circularly polarized attosecond pulses for specific internuclear distances.

  10. Attosecond-magnetic-field-pulse generation by intense few-cycle circularly polarized UV laser pulses

    Science.gov (United States)

    Yuan, Kai-Jun; Bandrauk, André D.

    2013-07-01

    Intense attosecond-magnetic-field pulses are predicted to be produced by intense few-cycle attosecond circularly polarized UV pulses. Numerical solutions of the time-dependent Schrödinger equation for H2+ are used to study the electronic dynamical process. Spinning attosecond circular electron wave packets are created on subnanometer molecular dimensions, thus generating attosecond magnetic fields of several tens of Teslas (105 G). Simulations show that the induced magnetic field is critically dependent on the pulse wavelength λ and pulse duration nτ (n is number of cycles) as predicted by a classical model. For ultrashort few-cycle circularly polarized attosecond pulses, molecular orientation influences the generation of the induced magnetic fields as a result of preferential ionization perpendicular to the molecular axis. The nonspherical asymmetry of molecules allows for efficient attosecond-magnetic-field-pulse generation.

  11. Attosecond Magnetic Field Pulse Generation by Intense Few Cycle Circularly Polarized UV Pulses

    CERN Document Server

    Yuan, Kai-Jun

    2013-01-01

    Intense attosecond magnetic field pulses are predicted to be produced by intense few cycle circularly polarized UV pulses. Numerical solutions of the time dependent Schr\\"{o}dinger equation for H$_2^+$ are used to study the dynamical process. Spiralling attosecond circular electron wave packets are created with nanometer molecular dimensions, thus generating magnetic fields of several tens of Teslas ($10^5$ Gauss). Simulations show that the induced magnetic field is critically dependent on the pulse wavelength $\\lambda$ and pulse duration $n\\tau$ ($n$ number of cycle) as predicted by a classical model. For ultrashort few cycle circularly polarized attosecond pulses, molecular orientation influences the generation of the induced magnetic fields as a result of preferential ionization perpendicular to the molecular axis.

  12. Stress Intensity Factors of Semi-Circular Bend Specimens with Straight-Through and Chevron Notches

    Science.gov (United States)

    Ayatollahi, M. R.; Mahdavi, E.; Alborzi, M. J.; Obara, Y.

    2016-04-01

    Semi-circular bend specimen is one of the useful test specimens for determining fracture toughness of rock and geo-materials. Generally, in rock test specimens, initial cracks are produced in two shapes: straight-edge cracks and chevron notches. In this study, the minimum dimensionless stress intensity factors of semi-circular bend specimen (SCB) with straight-through and chevron notches are calculated. First, using finite element analysis, a suitable relation for the dimensionless stress intensity factor of SCB with straight-through crack is presented based on the normalized crack length and half-distance between supports. For evaluating the validity and accuracy of this relation, the obtained results are then compared with numerical and experimental results reported in the literature. Subsequently, by performing some experiments and also finite element analysis of the SCB specimen with chevron notch, the minimum dimensionless stress intensity factor of this specimen is obtained. Using the new equation for the dimensionless stress intensity factor of SCB with straight-through crack and an analytical method, i.e., Bluhm's slice synthesis method, the minimum (critical) dimensionless stress intensity factor of chevron notched semi-circular bend specimens is calculated. Good agreement is observed between the results of two mentioned methods.

  13. Energetics, structures, vibrational frequencies, vibrational absorption, vibrational circular dichroism and Raman intensities of Leu-enkephalin

    DEFF Research Database (Denmark)

    Jalkanen, Karl J.

    2003-01-01

    Here we present several low energy conformers of Leu-enkephalin (LeuE) calculated with the density functional theory using the Becke 3LYP hybrid functional and the 6-31G* basis set. The structures, conformational energies, vibrational frequencies, vibrational absorption (VA) intensities......, vibrational circular dichroism (VCD) intensities and Raman scattering intensities are reported for the conformers of LeuE which are expected to be populated at room temperature. The species of LeuE-present in non-polar solvents is the neutral non-ionic species with the NH2 and CO2H groups, in contrast to the...

  14. Circularly polarized attosecond pulses from molecular high-order harmonic generation by ultrashort intense bichromatic circularly and linearly polarized laser pulses

    Science.gov (United States)

    Yuan, Kai-Jun; Bandrauk, André D.

    2012-04-01

    We describe the generation of high-order elliptically and circularly polarized harmonic spectra in an aligned H+2 molecule ion by a combination of two-colour ultrashort intense laser fields from numerical solutions of the corresponding time-dependent Schrödinger equation (TDSE). In intense bichromatic circularly and linearly or circularly polarized laser pulses with intensity I0 and angular frequencies ω0 and 2ω0, it is found that maximum molecular high-order harmonic generation (MHOHG) energies are functions of the molecular internuclear distance. Based on a classical model of laser-induced electron collisions with neighbouring ions, the optimal values of the pulse relative carrier envelope phase phi, the molecular internuclear distance R and the angle thetav of molecular alignment to the laser polarization axis are obtained for efficiently producing MHOHG spectra with the maximum harmonic energy Ip + 13.5Up, where Ip is the ionization potential of the molecule and Up = I0/4meω20 is the ponderomotive energy of the continuum electron at intensity I0 and frequency ω0 of the laser pulse. The results have been confirmed from corresponding TDSE nonperturbative numerical simulations. The polarization property of the generated harmonics is also presented. The mechanism of MHOHG is further characterized with a Gabor time frequency analysis. It is confirmed that a single collision trajectory of the continuum electron with neighbouring ions dominates in the MHOHG processes. The high efficiency of the proposed MHOHG scheme provides a possible source for production of elliptically and/or circularly polarized attosecond extreme ultraviolet pulses. Circularly polarized attosecond pulses can also be generated by using intense ultrashort circularly polarized laser pulses in combination with static electric fields of comparable intensity for H+2 at equilibrium. A time frequency analysis also confirms the role of single recollisions as the dominant mechanism of the generation

  15. Circularly polarized attosecond pulses from molecular high-order harmonic generation by ultrashort intense bichromatic circularly and linearly polarized laser pulses

    International Nuclear Information System (INIS)

    We describe the generation of high-order elliptically and circularly polarized harmonic spectra in an aligned H+2 molecule ion by a combination of two-colour ultrashort intense laser fields from numerical solutions of the corresponding time-dependent Schrödinger equation (TDSE). In intense bichromatic circularly and linearly or circularly polarized laser pulses with intensity I0 and angular frequencies ω0 and 2ω0, it is found that maximum molecular high-order harmonic generation (MHOHG) energies are functions of the molecular internuclear distance. Based on a classical model of laser-induced electron collisions with neighbouring ions, the optimal values of the pulse relative carrier envelope phase φ, the molecular internuclear distance R and the angle thetav of molecular alignment to the laser polarization axis are obtained for efficiently producing MHOHG spectra with the maximum harmonic energy Ip + 13.5Up, where Ip is the ionization potential of the molecule and Up = I0/4meω20 is the ponderomotive energy of the continuum electron at intensity I0 and frequency ω0 of the laser pulse. The results have been confirmed from corresponding TDSE nonperturbative numerical simulations. The polarization property of the generated harmonics is also presented. The mechanism of MHOHG is further characterized with a Gabor time frequency analysis. It is confirmed that a single collision trajectory of the continuum electron with neighbouring ions dominates in the MHOHG processes. The high efficiency of the proposed MHOHG scheme provides a possible source for production of elliptically and/or circularly polarized attosecond extreme ultraviolet pulses. Circularly polarized attosecond pulses can also be generated by using intense ultrashort circularly polarized laser pulses in combination with static electric fields of comparable intensity for H+2 at equilibrium. A time frequency analysis also confirms the role of single recollisions as the dominant mechanism of the generation

  16. Molecular photoelectron angular distributions with intense attosecond circularly polarized UV laser pulses

    Science.gov (United States)

    Yuan, Kai-Jun; Chelkowski, Szczepan; Bandrauk, André D.

    2014-01-01

    We investigate effects of intermediate resonant electronic states on molecular photoelectron angular distributions (MPADs) by intense circularly polarized attosecond UV laser pulses. Simulations are performed on aligned H2+ by numerically solving the corresponding three dimensional time dependent Schrödinger equations. MPADs exhibit signature of rotations, which is shown to be critically sensitive to the symmetry of the intermediate resonant electronic state and the pulse intensity. This sensitivity is attributed to the coherent population transfer in the initial and intermediate resonant states, thus suggesting a method to control molecular photoionization on attosecond time scale.

  17. Crack detection in circular cylindrical shells using differential quadrature method

    International Nuclear Information System (INIS)

    The differential quadrature method combined with an evolutionary optimization algorithm has been proposed for crack detection in cylindrical shell structures. The circumferential crack, which is assumed to be open, is modeled by the extended rotational spring. A crack with finite length divides the shell into four segments. The governing differential equations of motion of the shell are formulated based on Flugge's shell theory. Applying differential quadrature to the differential equations of each segment and the corresponding boundary and continuity conditions results in an algebraic system of equations. Then, an eigenvalue analysis is performed to obtain the natural frequencies of the cracked shell. To identify the crack parameters, an optimization problem is defined and minimized by Bees algorithm, a swarm-based evolutionary optimization technique. The integrity and applicability of the proposed method is confirmed by some experimental case studies. The results show that the crack statuses are predicted well. -- Highlights: • The problem of crack detection in cylindrical shell structures is investigated. • To do this, the differential quadrature method and bees algorithm has been used. • Numerical and experimental studies on the cracked free–free shells were conducted. • The results showed that the crack locations, sizes and depths were predicted well

  18. The nonlinear effect in relativistic Compton scattering for an intense circularly polarized laser

    Science.gov (United States)

    Luo, W.; Zhuo, H. B.; Ma, Y. Y.; Zhu, Z. C.; Fan, G. T.; Xu, W.; Song, Y. M.

    2014-07-01

    Compton scattering between an intense laser pulse and a relativistic electron beam offers a promising development path toward high-energy, high-brightness x- and gamma-ray sources. Increasing laser peak power to obtain intense x- and gamma rays causes nonlinear Compton scattering to occur. To predict high-order harmonic radiation properties, we upgrade a Monte Carlo laser-Compton scattering simulation code (MCLCSS) by taking into account the nonlinear effect for the relativistic Compton scattering process. The energy spectra and angular and harmonic intensity distributions of the scattered photons are investigated using nonlinear Compton scattering of an intense circularly polarized laser. It is found that the laser parameter {{a}_{0}}\\equiv e{\\rm{A}}\\;{{m}_{e}}{{c}^{-2}} plays an important role in the generation of high-order harmonic radiation. Our study also suggests that the high-energy tails of the second and higher harmonics will stray from the backscattering region.

  19. Molecular above-threshold-ionization angular distributions with intense circularly polarized attosecond XUV laser pulses

    Science.gov (United States)

    Yuan, Kai-Jun; Bandrauk, André D.

    2012-05-01

    Photoionization of aligned and fixed nuclei three-dimensional H2+ and two-dimensional H2 by intense circularly polarized attosecond extreme ultraviolet laser pulses is investigated from numerical solutions of the time-dependent Schrödinger equation. Molecular above-threshold-ionization angular distributions are found to be rotated with respect to the two laser perpendicular polarizations or, equivalently the symmetry axes of the molecule. The angle of rotation is critically sensitive to laser wavelength λ, photoelectron energy Een, and molecular internuclear distance R. The correlated interaction of the two electrons in H2 is shown to also influence such angular distribution rotations in different electronic states.

  20. Attospiral generation upon interaction of circularly polarized intense laser pulses with cone-like targets

    CERN Document Server

    Lécz, Zsolt

    2015-01-01

    Generation of high intensity attopulses is investigated in cylindrical geometry by using 3D particle-in-cell plasma simulation code. Due to the rotation symmetric target, a circularly polarized laser pulse is considered propagating on the axis of a hollow cone-like target. The large incidence angle and constant ponderomotive pressure leads to nano-bunching of relativistic electrons responsible for the laser-driven synchrotron emission. A numerical method is developed to find the source and direction of the coherent radiation that is responsible for the existence of attopulses. The intensity modulation in the harmonic spectrum is well described by the model of coherent synchrotron emission extended to the regime of higher order \\gamma-spikes. The spatial distribution of the higher harmonics resembles a spiral shape which gets focused into a small volume behind the target.

  1. Axial magnetic field generation by intense circularly polarized laser pulses in underdense plasmas

    International Nuclear Information System (INIS)

    Axial magnetic field generation by intense circularly polarized laser beams in underdense plasmas has been studied with three-dimensional particle-in-cell simulations and by means of theoretical analysis. Comparisons between analytical models and simulation results have identified an inverse Faraday effect as the main mechanism of the magnetic field generation in inhomogeneous plasmas. The source of azimuthal nonlinear currents and of the axial magnetic field depends on the transverse inhomogeneities of the electron density and laser intensity. The fields reach a maximum strength of several tens of megagauss for laser pulses undergoing relativistic self-focusing and channeling in moderately relativistic regime. Ultrarelativistic laser conditions inhibit magnetic field generation by directly reducing a source term and by generating fully evacuated plasma channels.

  2. Ultra-intense single attosecond pulse generated from circularly polarized laser interacting with overdense plasma

    Science.gov (United States)

    Ji, Liangliang; Shen, Baifei; Zhang, Xiaomei; Wen, Meng; Xia, Changquan; Wang, Wenpeng; Xu, Jiancai; Yu, Yahong; Yu, Mingyang; Xu, Zhizhan

    2011-08-01

    Few-cycle relativistic circularly polarized (CP) laser pulse reflected from overdense plasma is investigated by analysis and particle-in-cell simulations. It is found that through the laser-induced one-time drastic oscillation of the plasma boundary, an ultra-intense single attosecond light pulse can be generated naturally. An analytical model is proposed to describe the interaction and it agrees well with simulation results. They both indicate that peak intensity of the generated attosecond pulse is higher when the plasma density is closer to the relativistic transparency threshold and/or the pulse duration is closer to plasma oscillating period. Two dimensional simulation shows that a two-cycle 1021 W/cm2 CP laser can generate a single 230 attosecond 2 × 1021 W/cm2 pulse of light at a conversion efficiency greater than 10-2.

  3. Rotations of molecular photoelectron angular distributions with intense ultrashort circularly polarized attosecond laser pulses

    Science.gov (United States)

    Yuan, Kai-Jun; Chelkowski, Szczepan; Bandrauk, André D.

    2013-04-01

    Molecular photoelectron angular distributions (MPADs) by intense (I0 ⩾ 1014 W/cm2) circularly polarized ultrashort, few cycle (attosecond) ultraviolet laser pulses are presented from numerical solutions of time dependent Schrödinger equations. For the aligned molecular ion H_2^+, the MPADs exhibit rotations with respect to the polarization and molecular symmetry axes which are determined by the symmetry of the initial electronics states. It is also found that the rotation angle of MPADs is insensitive to the pulse intensity. We attribute these effects to the asymmetry between the parallel and perpendicular (to the molecular axis) polarization photoionization. Influence of the molecular alignment and ionizing pulse ellipticity on the rotation of MPADs is also shown to allow control of the nonsymmetric ionization.

  4. Ultra-intense single attosecond pulse generated from circularly polarized laser interacting with overdense plasma

    Energy Technology Data Exchange (ETDEWEB)

    Ji Liangliang; Shen Baifei; Zhang Xiaomei; Wen Meng; Xia Changquan; Wang Wenpeng; Xu Jiancai; Yu Yahong; Xu Zhizhan [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P. O. Box 800-211, Shanghai 201800 (China); Yu Mingyang [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China)

    2011-08-15

    Few-cycle relativistic circularly polarized (CP) laser pulse reflected from overdense plasma is investigated by analysis and particle-in-cell simulations. It is found that through the laser-induced one-time drastic oscillation of the plasma boundary, an ultra-intense single attosecond light pulse can be generated naturally. An analytical model is proposed to describe the interaction and it agrees well with simulation results. They both indicate that peak intensity of the generated attosecond pulse is higher when the plasma density is closer to the relativistic transparency threshold and/or the pulse duration is closer to plasma oscillating period. Two dimensional simulation shows that a two-cycle 10{sup 21} W/cm{sup 2} CP laser can generate a single 230 attosecond 2 x 10{sup 21} W/cm{sup 2} pulse of light at a conversion efficiency greater than 10{sup -2}.

  5. Irreversible Denaturation of Maltodextrin Glucosidase Studied by Differential Scanning Calorimetry, Circular Dichroism, and Turbidity Measurements

    OpenAIRE

    Goyal, Megha; Chaudhuri, Tapan K; Kuwajima, Kunihiro

    2014-01-01

    Thermal denaturation of Escherichia coli maltodextrin glucosidase was studied by differential scanning calorimetry, circular dichroism (230 nm), and UV-absorption measurements (340 nm), which were respectively used to monitor heat absorption, conformational unfolding, and the production of solution turbidity. The denaturation was irreversible, and the thermal transition recorded at scan rates of 0.5–1.5 K/min was significantly scan-rate dependent, indicating that the thermal denaturation was ...

  6. Quasistatic limit of the strong-field approximation describing atoms in intense laser fields: Circular polarization

    CERN Document Server

    Bauer, J H

    2010-01-01

    In the recent work of Vanne and Saenz [Phys. Rev. A 75, 063403 (2007)] the quasistatic limit of the velocity gauge strong-field approximation describing the ionization rate of atomic or molecular systems exposed to linearly polarized laser fields was derived. It was shown that in the low-frequency limit the ionization rate is proportional to the laser frequency (for a constant intensity of the laser field). In the present work I show that for circularly polarized laser fields the ionization rate is proportional to higher powers of the laser frequency for hydrogenic atoms. The new analytical expressions for asymptotic ionization rates (which become accurate in the quasistatic limit) contain no summations over multiphoton contributions. For very low laser frequencies (optical or infrared), these expressions usually remain with an order-of-magnitude agreement with the velocity gauge strong-field approximation.

  7. Energetically efficient proportional-integral-differential (PID) control of wake vortices behind a circular cylinder

    Science.gov (United States)

    Das, Pramode K.; Mathew, Sam; Shaiju, A. J.; Patnaik, B. S. V.

    2016-02-01

    The control of vortex shedding behind a circular cylinder is a precursor to a wide range of external shear flow problems in engineering, in particular the flow-induced vibrations. In the present study, numerical simulation of an energetically efficient active flow control strategy is proposed, for the control of wake vortices behind a circular cylinder at a low Reynolds number of 100. The fluid is assumed to be incompressible and Newtonian with negligible variation in properties. Reflectionally symmetric controllers are designed such that, they are located on a small sector of the cylinder over which, tangential sliding mode control is imparted. In the field of modern controls, proportional (P), integral (I) and differential (D) control strategies and their numerous combinations are extremely popular in industrial practice. To impart suitable control actuation, the vertically varying lift force on the circular cylinder, is synthesised for the construction of an error term. Four different types of controllers considered in the present study are, P, I, PI and PID. These controllers are evaluated for their energetic efficiency and performance. A linear quadratic optimal control problem is formulated, to minimise the cost functional. By performing detailed simulations, it was observed that, the system is energetically efficient, even when the twin eddies are still persisting behind the circular cylinder. To assess the adaptability of the controllers, the actuators were switched on and off to study their dynamic response.

  8. Energetics, structures, vibrational frequencies, vibrational absorption, vibrational circular dichroism and Raman intensities of Leu-enkephalin

    International Nuclear Information System (INIS)

    Here we present several low energy conformers of Leu-enkephalin (LeuE) calculated with the density functional theory using the Becke 3LYP hybrid functional and the 6-31G* basis set. The structures, conformational energies, vibrational frequencies, vibrational absorption (VA) intensities, vibrational circular dichroism (VCD) intensities and Raman scattering intensities are reported for the conformers of LeuE which are expected to be populated at room temperature. The species of LeuE present in non-polar solvents is the neutral non-ionic species with the NH2 and CO2H groups, in contrast to the zwitterionic neutral species with the NH3+ and CO2- groups which predominates in aqueous solution and in the crystal. All of our attempts to find the zwitterionic species in the isolated state failed, with the result that a hydrogen atom from the positively charged N-terminus ammonium group transferred either to one of the oxygens of the carboxylate group of the C-terminus or to the oxygen of the amide group of one of the other residues. Hence we conclude that the zwitterionic species of LeuE is not stable in the isolated state. Spectral simulations of the species expected to be found in the isolated state can be compared to the measured VA, VCD and Raman spectra of LeuE in non-polar solvents to identify which conformer or conformers of LeuE are present in these media. Characteristic features in the VCD spectra are more sensitive to conformational changes than those in either the VA or Raman spectra, similar to the characteristic features in electronic circular dichroism spectra with respect to those in the UV-vis electronic absorption spectra. Finally, we have also attempted to stabilize the zwitterionic species by treating the aqueous environment by using a continuum solvent approach, the Onsager model. Here we found that the zwitterionic species is now stable. The neutral species in an aqueous environment was also modelled by the continuum solvent approaches to determine the

  9. Propagation of intense and short circularly polarized pulses in a molecular gas: From multiphoton ionization to nonlinear macroscopic effects

    Science.gov (United States)

    Lytova, M.; Lorin, E.; Bandrauk, A. D.

    2016-07-01

    We present a detailed analysis of the propagation dynamics of short and intense circularly polarized pulses in an aligned diatomic gas. Compared to linearly polarized intense pulses, high harmonic generation (HHG) and the coherent generation of attosecond pulses in the intense-circular-polarization case are a new research area. More specifically, we numerically study the propagation of intense and short circularly polarized pulses in the one-electron H2+ molecular gas, using a micro-macro Maxwell-Schrödinger model. In this model, the macroscopic polarization is computed from the solution of a large number of time-dependent Schrödinger equations, the source of dipole moments, and using a trace operator. We focus on the intensity and the phase of harmonics generated in the H2+ gas as a function of the pulse-propagation distance. We show that short coherent circularly polarized pulses of same helicity can be generated in the molecular gas as a result of cooperative phase-matching effects.

  10. Transfrontier macroseismic data exchange in NW Europe: examples of non-circular intensity distributions

    Science.gov (United States)

    Van Noten, Koen; Lecocq, Thomas; Hinzen, Klaus-G.; Sira, Christophe; Camelbeeck, Thierry

    2016-04-01

    Macroseismic data acquisition recently received a strong increase in interest due to public crowdsourcing through internet-based inquiries and real-time smartphone applications. Macroseismic analysis of felt earthquakes is important as the perception of people can be used to detect local/regional site effects in areas without instrumentation. We will demonstrate how post-processing macroseismic data improves the quality of real-time intensity evaluation of new events. Instead of using the classic DYFI representation in which internet intensities are averaged per community, we, first, geocoded all individual responses and structure the model area into 100 km2grid cells. Second, the average intensity of all answers within a grid cell is calculated. The resulting macroseismic grid cell distribution shows a less subjective and more homogeneous intensity distribution than the classical irregular community distribution and helps to improve the calculation of intensity attenuation functions. In this presentation, the 'Did You Feel It' (DYFI) macroseismic data of several >M4, e.g. the 2002 ML 4.9 Alsdorf and 2011 ML 4.3 Goch (Germany) and the 2015 ML 4.1 Ramsgate (UK), earthquakes felt in Belgium, Germany, The Netherlands, France, Luxemburg and UK are analysed. Integration of transfrontier DYFI data of the ROB-BNS, KNMI, BCSF and BGS networks results in a particular non-circular, distribution of the macroseismic data in which the felt area for all these examples extends significantly more in E-W than N-S direction. This intensity distribution cannot be explained by geometrical amplitude attenuation alone, but rather illustrates a low-pass filtering effect due to the south-to-north increasing thickness of cover sediments above the London-Brabant Massif. For the studied M4 to M5 earthquakes, the thick sediments attenuate seismic energy at higher frequencies and consequently less people feel the vibrations at the surface. This example of successful macroseismic data exchange

  11. Single Circularly Polarized Attosecond Pulse Generation by Intense Few Cycle Elliptically Polarized Laser Pulses and Terahertz Fields from Molecular Media

    Science.gov (United States)

    Yuan, Kai-Jun; Bandrauk, André D.

    2013-01-01

    We present a method for producing a single circularly polarized attosecond pulse by an intense few cycle elliptically polarized laser pulse combined with a terahertz field from numerical solutions of the time-dependent Schrödinger equation for the molecular ion H2+. It is found that in the presence of a 62.5 THz (λ=4800nm) field at an intensity of ˜1014W/cm2, a single circularly polarized 114 as pulse can be generated by an elliptical polarized laser pulse at a wavelength of 400 nm with an ellipticity of ɛ=0.59. The efficiency of circular polarization attosecond pulse generation is interpreted based on a classical model of single electron recollision with the parent ion.

  12. Proposal of coherent Cherenkov radiation matched to circular plane wave for intense terahertz light source

    Energy Technology Data Exchange (ETDEWEB)

    Sei, Norihiro, E-mail: sei.n@aist.go.jp [Research Institute for Measurement and Analytical Instrumentation, National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Sakai, Takeshi; Hayakawa, Ken; Tanaka, Toshinari; Hayakawa, Yasushi; Nakao, Keisuke; Nogami, Kyoko; Inagaki, Manabu [Laboratory for Electron Beam Research and Application, Nihon University, 7-24-1 Narashinodai, Funabashi 274-8501 (Japan)

    2015-10-09

    Highlights: • We proposed a new intense terahertz-wave source based on coherent Cherenkov radiation (CCR). • A hollow conical dielectric is used to generate the CCR beam. • The wave front of the CCR beam can be matched to the basal plane. • The peak-power of the CCR beam is above 1 MW per micropulse with a short interval of 350 ps. - Abstract: We propose a high-peak-power terahertz-wave source based on an electron accelerator. By passing an electron beam through a hollow conical dielectric with apex facing the incident electron beam, the wave front of coherent Cherenkov radiation generated on the inner surface of the hollow conical dielectric matches the basal plane. Using the electron beam generated at the Laboratory for Electron Beam Research and Application at Nihon University, the calculated power of coherent Cherenkov radiation that matched the circular plane (CCR-MCP) was above 1 MW per micropulse with a short interval of 350 ps, for wavelengths ranging from 0.5 to 5 mm. The electron beam is not lost for generating the CCR-MCP beam by using the hollow conical dielectric. It is possible to combine the CCR-MCP beams with other light sources based on an accelerator.

  13. Responsivity of the differential-intensity surface plasmon resonance instrument

    OpenAIRE

    Abayzeed, Sidahmed A.; Richard J. Smith; Webb, Kevin F.; Somekh, Michael G.; See, Chung W.

    2016-01-01

    Surface plasmon resonance is used for the sensitive measurement of minute concentrations of bio-analytes and probing of electrochemical processes. Typical refractive index sensitivity, for the intensity approach, is around 10−6 refractive index units (RIUs). A better sensitivity has been suggested by developing a differential-intensity detection method. This method relies on the excitation of surface plasmons using a weakly focused beam with the average angle of incidence equal to the resonan...

  14. Computational efficiency improvement with Wigner rotation technique in studying atoms in intense few-cycle circularly polarized pulses

    International Nuclear Information System (INIS)

    We show that by introducing Wigner rotation technique into the solution of time-dependent Schrödinger equation in length gauge, computational efficiency can be greatly improved in describing atoms in intense few-cycle circularly polarized laser pulses. The methodology with Wigner rotation technique underlying our openMP parallel computational code for circularly polarized laser pulses is described. Results of test calculations to investigate the scaling property of the computational code with the number of the electronic angular basis function l as well as the strong field phenomena are presented and discussed for the hydrogen atom

  15. Optical time-domain differentiation based on intensive differential group delay

    Institute of Scientific and Technical Information of China (English)

    Li Zheng-Yong; Yu Xiang-Zhi; Wu Chong-Qing

    2011-01-01

    An optical time-domain differentiation scheme is proposed and demonstrated based on the intensive differential group delay in a high birefringence fibre waveguide.Results show that the differentiation waveforms agree well with the mathematically calculated derivatives.Both error and efficiency will increase when the birefringence fibre becomes longer,and the error rises up more quickly while the efficiency approaches to a maximum of ~0.25.By using a 1-m birefringence fibre a lower error of ~0.26% is obtained with an efficiency of 1% for the first-order differentiation of 10-ps Gaussian optical pulses,and the high-order optical differentiation up to 4th order is achieved with an error less than 3%.Due to its compact structure being easy to integrate and cascade into photonic circuits,our scheme has great potential for ultrafast signal processing.

  16. Optical time-domain differentiation based on intensive differential group delay

    International Nuclear Information System (INIS)

    An optical time-domain differentiation scheme is proposed and demonstrated based on the intensive differential group delay in a high birefringence fibre waveguide. Results show that the differentiation waveforms agree well with the mathematically calculated derivatives. Both error and efficiency will increase when the birefringence fibre becomes longer, and the error rises up more quickly while the efficiency approaches to a maximum of ∼0.25. By using a 1-m birefringence fibre a lower error of ∼0.26% is obtained with an efficiency of 1% for the first-order differentiation of 10-ps Gaussian optical pulses, and the high-order optical differentiation up to 4th order is achieved with an error less than 3%. Due to its compact structure being easy to integrate and cascade into photonic circuits, our scheme has great potential for ultrafast signal processing. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  17. Generation of intense circularly polarized attosecond light bursts from relativistic laser plasmas

    CERN Document Server

    Ma, Guangjin; Yu, M Y; Shen, Baifei; Veisz, Laszlo

    2016-01-01

    We have investigated the polarization of attosecond light bursts generated by nanobunches of electrons from relativistic few-cycle laser pulse interaction with the surface of overdense plasmas. Particle-in-cell simulation shows that the polarization state of the generated attosecond burst depends on the incident-pulse polarization, duration, carrier envelope phase, as well as the plasma scale length. Through laser and plasma parameter control, without compromise of generation efficiency, a linearly polarized laser pulse with azimuth $\\theta^i=10^\\circ$ can generate an elliptically polarized attosecond burst with azimuth $|\\theta^r_{\\rm atto}|\\approx61^\\circ$ and ellipticity $\\sigma^r_{\\rm atto}\\approx0.27$; while an elliptically polarized laser pulse with $\\sigma^i\\approx0.36$ can generate an almost circularly polarized attosecond burst with $\\sigma^r_{\\rm atto}\\approx0.95$. The results propose a new way to a table-top circularly polarized XUV source as a probe with attosecond scale time resolution for many a...

  18. Angle-dependent molecular above-threshold ionization with ultrashort intense linearly and circularly polarized laser pulses

    International Nuclear Information System (INIS)

    We present molecular above-threshold ionization (MATI) spectra generated by ultrashort intense linearly and circularly polarized laser pulses from nonperturbative numerical solutions of the corresponding time-dependent Schroedinger equation in the molecular-ion H2+. It is found that high-order MATI spectra with maximum kinetic energy 32Up, where Up=I0/4meω02 is the ponderomotive energy at intensity I0 and frequency ω0, can be obtained in H2+ at great internuclear distances R for both linear and circular polarizations. Quasiclassical laser-induced collision models confirm that such high-order MATIs mainly result from a collision with neighboring ions of the ionized electron. Interference patterns in the high-order MATI spectra are critically sensitive to both the internuclear distance R of the molecules and the polarizations of the driving laser pulses. Moreover, with few-cycle laser pulses, the carrier-envelope phase sensitivity of MATI angular distributions is also investigated for varying internuclear distances R. At critical internuclear distances for charge-resonance-enhanced ionization, we also find that enhanced interference patterns occur.

  19. Two-center interference in molecular photoelectron energy spectra with intense attosecond circularly polarized XUV laser pulses

    Science.gov (United States)

    Yuan, Kai-Jun; Bian, Xue-Bin; Bandrauk, André D.

    2014-08-01

    We study two-center electron interference in molecular photoionization processes by intense attosecond circularly polarized extreme ultraviolet (XUV) laser pulses in both symmetric H2+ and nonsymmetric HHe2+ one-electron diatomic systems. Simulations from numerical solutions of time-dependent Schrödinger equations for the oriented symmetric molecular ion H2+ exhibit a signature of interference with double peaks (minima) in molecular attosecond photoelectron energy spectra (MAPES) at critical angles ϑc between the continuum electron momentum pe and the molecular internuclear R axis. The interference patterns are shown to be influenced by the molecular Coulomb potential, leading to a shift of the critical angle ϑc. Dependence of the two-center interference on the pulse ellipticity is also investigated. Furthermore, it is found that the interference phenomena are critically sensitive to the molecular orbital symmetry. For the nonsymmetric molecular ion HHe2+, such double peaks in MAPES also occur, thus suggesting a method for imaging orbitals in molecules by intense ultrashort circularly polarized XUV pulses on the attosecond time scale.

  20. Ionization of oriented carbonyl sulfide molecules by intense circularly polarized laser pulses

    DEFF Research Database (Denmark)

    Dimitrovski, Darko; Abu-Samha, Mahmoud; Madsen, Lars Bojer;

    2011-01-01

    We present combined experimental and theoretical results on strong-field ionization of oriented carbonyl sulfide molecules by circularly polarized laser pulses. The obtained molecular frame photoelectron angular distributions show pronounced asymmetries perpendicular to the direction of the......-dimensionally-oriented polar molecules, in particular asymmetries in the emission direction of the photoelectrons. In the following article [Phys. Rev. A 83, 023406 (2011)] the focus is to understand strong-field ionization from three-dimensionally-oriented asymmetric top molecules, in particular the suppression of electron...... molecular electric dipole moment. These findings are explained by a tunneling model invoking the laser-induced Stark shifts associated with the dipoles and polarizabilities of the molecule and its unrelaxed cation. The focus of the present article is to understand the strong-field ionization of one...

  1. Acoustics flow analysis in circular duct using sound intensity and dynamic mode decomposition

    International Nuclear Information System (INIS)

    Sound intensity generation in hard-walled duct with acoustic flow (no mean-flow) is treated experimentally and shown graphically. In paper, numerous methods of visualization illustrating the vortex flow (2D, 3D) can graphically explain diffraction and scattering phenomena occurring inside the duct and around open end area. Sound intensity investigation in annular duct gives a physical picture of sound waves in any duct mode. In the paper, modal energy analysis are discussed with particular reference to acoustics acoustic orthogonal decomposition (AOD). The image of sound intensity fields before and above 'cut-off' frequency region are found to compare acoustic modes which might resonate in duct. The experimental results show also the effects of axial and swirling flow. However acoustic field is extremely complicated, because pressures in non-propagating (cut-off) modes cooperate with the particle velocities in propagating modes, and vice versa. Measurement in cylindrical duct demonstrates also the cut-off phenomenon and the effect of reflection from open end. The aim of experimental study was to obtain information on low Mach number flows in ducts in order to improve physical understanding and validate theoretical CFD and CAA models that still may be improved.

  2. Nonlinear optics as a path to high-intensity circular machines

    CERN Document Server

    Nagaitsev, Sergei; Danilov, V

    2012-01-01

    What prevents us from building super-high intensity accelerators? The answer is case-specific, but it often points to one of the following phenomena: machine resonances, various tune shifts (and spreads), and instabilities. These three phenomena are interdependent in all present machines. In this paper we propose a path toward alleviating these phenomena by making accelerators nonlinear. This idea is not new: Orlov (1963) and McMillan (1967) have proposed initial ideas on nonlinear focusing systems for accelerators. However, practical implementations of such ideas proved elusive, until recently.

  3. Anharmonic Effects on Vibrational Spectra Intensities: Infrared, Raman, Vibrational Circular Dichroism, and Raman Optical Activity.

    Science.gov (United States)

    Bloino, Julien; Biczysko, Malgorzata; Barone, Vincenzo

    2015-12-10

    The aim of this paper is 2-fold. First, we want to report the extension of our virtual multifrequency spectrometer (VMS) to anharmonic intensities for Raman optical activity (ROA) with the full inclusion of first- and second-order resonances for both frequencies and intensities in the framework of the generalized second-order vibrational perturbation theory (GVPT2) for all kinds of vibrational spectroscopies. Then, from a more general point of view, we want to present and validate the performance of VMS for the parallel analysis of different vibrational spectra for medium-sized molecules (IR, Raman, VCD, ROA) including both mechanical and electric/magnetic anharmonicity. For the well-known methyloxirane benchmark, careful selection of density functional, basis set, and resonance thresholds permitted us to reach qualitative and quantitative agreement between experimental and computed band positions and shapes. Next, the whole series of halogenated azetidinones is analyzed, showing that it is now possible to interpret different spectra in terms of mass, electronegativity, polarizability, and hindrance variation between closely related substituents, chiral spectroscopies being particular effective in this connection. PMID:26580121

  4. Exercise intensity differentially impacts sensitivity thresholds to specific tastes

    Directory of Open Access Journals (Sweden)

    Nakanishi Y

    2015-04-01

    Full Text Available The purpose of this study was to compare the impact of exercise intensity on sensitivity to four major tastes of sweet, sour, salty, and bitter. Ten subjects completed two separate 30-min cycling exercise bouts, one at low intensity (50% V •O2max and the other at high intensity (70% V •O2max. Sensitivity to the four tastes was assessed before and after each exercise bout, using taste discs. Comparative data were analyzed using paired t-tests and the relationships between work-related physiologic measures and taste sensitivities were calculated using Pearson correlation. Significance was established at the 0.05 level of probability. Post-exercise sourness threshold was higher (p≤0.05 following the high intensity exercise compared to the low intensity exercise, sweetness threshold decreased following the higher intensity exercise (p≤0.05, while no differences were observed in threshold sensitivities for the other two tastes at either workload. The increased sensitivity to sweetness (decreased threshold was strongly related to changes in blood glucose following both low (r2=0.62; p<0.01 and high (r2=0.50; p≤0.05 intensity exercises. As well, changes observed in sourness threshold were directly related to the changes in core temperature (r2=0.49; p≤0.05 but only for the low intensity exercise bout.

  5. Differential Predictability of Four Dimensions of Affect Intensity

    Science.gov (United States)

    Rubin, David C.; Hoyle, Rick H.; Leary, Mark R.

    2013-01-01

    Individual differences in affect intensity are typically assessed with the Affect Intensity Measure (AIM). Previous factor analyses suggest that the AIM is comprised of four weakly correlated factors: Positive Affectivity, Negative Reactivity, Negative Intensity and Positive Intensity or Serenity. However, little data exist to show whether its four factors relate to other measures differently enough to preclude use of the total scale score. The present study replicated the four-factor solution and found that subscales derived from the four factors correlated differently with criterion variables that assess personality domains, affective dispositions, and cognitive patterns that are associated with emotional reactions. The results show that use of the total AIM score can obscure relationships between specific features of affect intensity and other variables and suggest that researchers should examine the individual AIM subscales. PMID:21707262

  6. EXPERIMENTAL IMPACT ASSESSMENT OF PARAMETERS PERTAINING TO BLANK TWO-DIMENSIONAL CIRCULAR MOTION ON INTENSITY OF ITS CUTTING AND QUALITY OF MACHINED SURFACE

    Directory of Open Access Journals (Sweden)

    M. G. Kiselev

    2014-01-01

    Full Text Available The purpose of the paper is to make an experimental impact assessment of parameters pertaining to blank two-dimensional circular blank motion on intensity of its cutting and quality of the machined surfaces. Experimental data have been obtained that reveal efficiency in application of blank circular motion and improvement of its output cutting indices.A methodology has been developed for execution of comparative experimental investigations on cutting glass, nephrite and jasper specimens as under conventional conditions required for the operation so while transferring induced oscillations to boom suspension assembly that ensure specimen.The proposed methodology makes it possible to assess quantitatively intensity of specimen cutting and quality of its machined surface. The paper has shown that a positive impact of the specimen circular motion on quality improvement of its cross-cut surface is related to peculiar kinematics features pertaining to relative motion of disc side surface with cross-cut portions of the specimen surface. It has been shown that the intensifying impact of the specimen circular motion on the cutting process is primarily related to the changes in dynamic conditions of its interaction with the cutting edge of the disc. In contrast to conventional cutting when the process is going on under static pressure of contacting surfaces there is their periodical impact-frictional interaction due to transfer of circular motion to the specimen along elliptical trajectory. In this case the rate of the positive impact of the specimen circular motion on its cross-cut surface becomes higher while increasing vertical velocity component that concerns its sliding relative to disc side surface that is ensured by increasing oscillation frequency which is transferred to the boom suspension assembly. Moreover, the rate of positive impact of the specimen circulatory motion on the quality of its cross-cut surface becomes higher while increasing

  7. Principles, effects and problems of differential power pricing policy for energy intensive industries in China

    International Nuclear Information System (INIS)

    The Chinese government canceled the preferential power pricing policies for energy intensive industries and imposed a reverse differential pricing policy in order to promote energy efficiency and the adjustment and upgrading of the industrial structure. This article analyzes the principles of China's differential power pricing policy, the externalities of energy and the modified Ramsey pricing rule, and also points out the policy implications of China's differential power pricing policy. In our samples, we investigate eight power intensive products in the Henan province with respect to their power consumption per unit (power intensity), electricity cost, total cost, the electricity tariff and profit, in order to test the effects of the differential power pricing policy. The results show that the primary effect of the differential power pricing policy is that enterprises decrease their total costs and improve their productive efficiencies in advance, in anticipating a higher electricity tariff. -- Research highlights: → The article suggests a modified Ramsey pricing model where demand elasticity is replaced by elasticity of energy consumption and polluting elasticity to internalize the negative externality of high energy intensive industry. → The article assesses the effects of differential pricing policy through on-site survey of high energy intensive industries in Henan province and analyzes the reasons behind those effects. → The article presents the lessons and policy implications of implementing differential pricing policy aimed at energy conservation and emission reduction.

  8. Administrative Circulars

    CERN Multimedia

    Département des Ressources humaines

    2004-01-01

    Administrative Circular N° 2 (Rev. 2) - May 2004 Guidelines and procedures concerning recruitment and probation period of staff members This circular has been revised. It cancels and replaces Administrative Circular N° 2 (Rev. 1) - March 2000. Administrative Circular N° 9 (Rev. 3) - May 2004 Staff members contracts This circular has been revised. It cancels and replaces Administrative Circular N° 9 (Rev. 2) - March 2000. Administrative Circular N° 26 (Rev. 4) - May 2004 Procedure governing the career evolution of staff members This circular has also been revised. It Administrative Circulars Administrative Circular N° 26 (Rev. 3) - December 2001 and brings up to date the French version (Rev. 4) published on the HR Department Web site in January 2004. Operational Circular N° 7 - May 2004 Work from home This circular has been drawn up. Operational Circular N° 8 - May 2004 Dealing with alcohol-related problems...

  9. Band intensities in the circular dichroism and absorption spectra and the states of d ions in absorbing media: I. Octahedrally coordinated positions of d ions

    International Nuclear Information System (INIS)

    The factors affecting the band intensity in circular dichroism (CD) and absorption spectra (selection rules, point group of structural position, and the electron density of the ground state of octahedrally coordinated d ion in absorbing medium) are considered. The intensities of CD and absorption bands are calculated and compared with the experimental data. It is shown that the differences in the spatial inversion of the electric- and magnetic-dipole moment transformations lead to a more rigorous validity of the symmetry selection rules and increase the resolution of peaks and transparency window of medium absorption in CD spectra (in contrast to absorption ones). Some criteria for estimating the valence and structural states of d ions are formulated.

  10. Ionization of one- and three-dimensionally-oriented asymmetric-top molecules by intense circularly polarized femtosecond laser pulses

    DEFF Research Database (Denmark)

    Hansen, Jonas Lerche; Holmegaard, Lotte; Kalhøj, Line;

    2011-01-01

    We present a combined experimental and theoretical study on strong-field ionization of a three-dimensionally-oriented asymmetric top molecule, benzonitrile (C7H5N), by circularly polarized, nonresonant femtosecond laser pulses. Prior to the interaction with the strong field, the molecules are......-oriented asymmetric top molecules, in particular the suppression of electron emission in nodal planes of molecular orbitals. In the preceding article [Dimitrovski et al., Phys. Rev. A 83, 023405 (2011)] the focus is to understand the strong-field ionization of one-dimensionally-oriented polar molecules, in particular...... quantum-state selected using a deflector and three-dimensionally (3D) aligned and oriented adiabatically using an elliptically polarized laser pulse in combination with a static electric field. A characteristic splitting in the molecular frame photoelectron momentum distribution reveals the position of...

  11. Fractional Differentiation-Based Active Contour Model Driven by Local Intensity Fitting Energy

    Directory of Open Access Journals (Sweden)

    Ming Gu

    2016-01-01

    Full Text Available A novel active contour model is proposed for segmentation images with inhomogeneity. Firstly, fractional order filter is defined by eight convolution masks corresponding to the image orientation in the eight compass directions. Then, the fractional order differentiation image is obtained and applied to the level set method. Secondly, we defined a new energy functional based on local image information and fractional order differentiation image; the proposed model not only can describe the input image more accurately but also can deal with intensity inhomogeneity. Local fitting term can enhance the ability of the model to deal with intensity inhomogeneity. The defined penalty term is used to reduce the occurrence of false boundaries. Finally, in order to eliminate the time-consuming step of reinitialization and ensure stable evolution of level set function, the Gaussian filtering method is used. Experiments on synthetic and real images show that the proposed model is efficient for images with intensity inhomogeneity and flexible to initial contour.

  12. Transport-of-intensity phase imaging using Savitzky-Golay differentiation filter--theory and applications.

    Science.gov (United States)

    Zuo, Chao; Chen, Qian; Yu, Yingjie; Asundi, Anand

    2013-03-11

    Several existing strategies for estimating the axial intensity derivative in the transport-of-intensity equation (TIE) from multiple intensity measurements have been unified by the Savitzky-Golay differentiation filter--an equivalent convolution solution for differentiation estimation by least-squares polynomial fitting. The different viewpoint from the digital filter in signal processing not only provides great insight into the behaviors, the shortcomings, and the performance of these existing intensity derivative estimation algorithms, but more important, it also suggests a new way of improving solution strategies by extending the applications of Savitzky-Golay differentiation filter in TIE. Two novel methods for phase retrieval based on TIE are presented--the first by introducing adaptive-degree strategy in spatial domain and the second by selecting optimal spatial frequencies in Fourier domain. Numerical simulations and experiments verify that the second method outperforms the existing methods significantly, showing reliable retrieved phase with both overall contrast and fine phase variations well preserved. PMID:23482106

  13. Rotations of molecular photoelectron angular distributions in above threshold ionization of H2+ by intense circularly polarized attosecond UV laser pulses

    International Nuclear Information System (INIS)

    We present molecular photoelectron angular distributions (MPADs) in multi-photon ionization processes by circularly polarized attosecond UV laser pulses. Simulations are performed on the single electron aligned molecular ion H2+ by solving corresponding 3D time-dependent Schrödinger equations. Numerical results of molecular above threshold ionization (MATI) show that rotations of MPADs with respect to the molecular and polarization axes depend on pulse intensities and photoelectron kinetic energies. We attribute the rotation to Γ, the difference between parallel and perpendicular ionization probabilities. It is found that in a resonant ionization process, the rotation angle is also a function of the symmetry of intermediate electronic states. The coherent population transfer between the initial and the resonant electronic states is controlled by pulse intensities. Such dependence of rotations on the pulse intensity is absent in Rydberg resonant ionizations as well as in MATI at large energy photons ℏω > Ip, where ω is angular frequency of photons and Ip is the molecular ionization potential. We describe these processes by a multi-photon perturbation theory model. Effects of molecular alignment and pulse ellipticities on rotations are investigated, confirming the essence of the ionization parameter Γ in rotations of MPADs. (paper)

  14. Rotations of molecular photoelectron angular distributions in above threshold ionization of H2+ by intense circularly polarized attosecond UV laser pulses

    Science.gov (United States)

    Yuan, Kai-Jun; Chelkowski, Szczepan; Bandrauk, André D.

    2014-10-01

    We present molecular photoelectron angular distributions (MPADs) in multi-photon ionization processes by circularly polarized attosecond UV laser pulses. Simulations are performed on the single electron aligned molecular ion H_2^+ by solving corresponding 3D time-dependent Schrödinger equations. Numerical results of molecular above threshold ionization (MATI) show that rotations of MPADs with respect to the molecular and polarization axes depend on pulse intensities and photoelectron kinetic energies. We attribute the rotation to Γ, the difference between parallel and perpendicular ionization probabilities. It is found that in a resonant ionization process, the rotation angle is also a function of the symmetry of intermediate electronic states. The coherent population transfer between the initial and the resonant electronic states is controlled by pulse intensities. Such dependence of rotations on the pulse intensity is absent in Rydberg resonant ionizations as well as in MATI at large energy photons ℏω > Ip, where ω is angular frequency of photons and Ip is the molecular ionization potential. We describe these processes by a multi-photon perturbation theory model. Effects of molecular alignment and pulse ellipticities on rotations are investigated, confirming the essence of the ionization parameter Γ in rotations of MPADs.

  15. Low-intensity pulsed ultrasound regulates proliferation and differentiation of osteoblasts through osteocytes

    International Nuclear Information System (INIS)

    Highlights: ► CM from LIPUS-stimulated osteocytes inhibits proliferation of osteoblasts. ► CM from LIPUS-stimulated osteocytes enhances differentiation of osteoblasts. ► LIPUS stimulates MLO-Y4 cells to secrete PGE2 and NO. -- Abstract: Low-intensity pulsed ultrasound (LIPUS) has been used as a safe and effective modality to enhance fracture healing. As the most abundant cells in bone, osteocytes orchestrate biological activities of effector cells via direct cell-to-cell contacts and by soluble factors. In this study, we have used the osteocytic MLO-Y4 cells to study the effects of conditioned medium from LIPUS-stimulated MLO-Y4 cells on proliferation and differentiation of osteoblastic MC3T3-E1 cells. Conditioned media from LIPUS-stimulated MLO-Y4 cells (LIPUS-Osteocyte-CM) were collected and added on MC3T3-E1 cell cultures. MC3T3-E1 cells cultured in LIPUS-Osteocyte-CM demonstrated a significant inhibition of proliferation and an increased alkaline phosphatase activity. The results of PGE2 and NO assay showed that LIPUS could enhance PGE2 and NO secretion from MLO-Y4 cells at all time points within 24 h after LIPUS stimulation. We conclude that LIPUS regulates proliferation and differentiation of osteoblasts through osteocytes in vitro. Increased secretion of PGE2 from osteocytes may play a role in this effect.

  16. Application of contrast enhanced sonography combined with time-intensity analysis in the differential diagnosis of breast lesions

    International Nuclear Information System (INIS)

    Objective: To explore the value of contrast enhanced sonography combined with time-intensity curve analysis in breast lesions. Methods: Based on pathologic analysis, thirty-six lesions were examined by contrast enhanced sonography, the time-intensity curve were evaluated respectively. Results: Typical malignant solid breast lesions had some characteristic enhancement modes. The time-intensity curve of malignant lesion was rather different form that of surround- ing tissues, but the time-intensity curve of benign mass was close to that of surrounding tissues. Conclusion: Contrast enhanced sonography combined with time-intensity analysis was helpful in the differential diagnosis of breast masses. (authors)

  17. Information Circulars

    International Nuclear Information System (INIS)

    Information circulars are published from time to time under the symbol INFCIRC/. . . . for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A list of the circulars which were of current interest on 15 January 1969 is given below, followed by an index to their subject matter. Other circulars can be traced by reference to earlier issues of the present document.

  18. Information circulars

    International Nuclear Information System (INIS)

    Information circulars are published from time to time under the symbol INFCIRC/... for the purpose of bringing matters of general interest to the attention of all Members of the Agency. The present revision contains INFCIRCs published up to mid-August 1994. A complete numerical list of information circulars is reproduced with their titles in the Annex

  19. Information circulars

    International Nuclear Information System (INIS)

    The document summarizes the Information Circulars published by the IAEA for the purpose of bringing matters of general interest to the attention of all Members of the Agency. This revision contains INFCIRCs published up to mid-August 1992. A complete numerical lift of Information Circulars with their titles is reproduced in an Annex

  20. Information circulars

    International Nuclear Information System (INIS)

    The document summarizes the Information Circulars published by the IAEA for the purpose of bringing matters of general interest to the attention of all Member States. This revision contains INFCIRCs published up to the end of May 1999, grouped by field of activity. A complete list of information circulars in numerical order is given in an annex

  1. Information Circulars

    International Nuclear Information System (INIS)

    Information circulars are published from time to time under the symbol INFCIRC/. for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A list of the circulars that were current on 31 December 1964 is given, followed by an index to their subject matter.

  2. Information circulars

    International Nuclear Information System (INIS)

    The document summarizes the Information Circulars published by the IAEA for the purpose of bringing matters of general interest to the attention of all Member States. This revision contains INFCIRCs published up to February 1997, grouped by field of activity. A complete list of information circulars in numerical order is given in an annex

  3. Information circulars

    International Nuclear Information System (INIS)

    Information circulars are published from time to time under the symbol INFCIRC/... for the purpose of bringing matters of general interest to the attention of all Members of the Agency. The present revision contains INFCIRCs published up to the end of April 2002. A complete numerical list of information circulars is reproduced with their titles in the Annex

  4. Low-intensity pulsed ultrasound regulates proliferation and differentiation of osteoblasts through osteocytes.

    Science.gov (United States)

    Li, Lei; Yang, Zheng; Zhang, Hai; Chen, Wenchuan; Chen, Mengshi; Zhu, Zhimin

    2012-02-10

    Low-intensity pulsed ultrasound (LIPUS) has been used as a safe and effective modality to enhance fracture healing. As the most abundant cells in bone, osteocytes orchestrate biological activities of effector cells via direct cell-to-cell contacts and by soluble factors. In this study, we have used the osteocytic MLO-Y4 cells to study the effects of conditioned medium from LIPUS-stimulated MLO-Y4 cells on proliferation and differentiation of osteoblastic MC3T3-E1 cells. Conditioned media from LIPUS-stimulated MLO-Y4 cells (LIPUS-Osteocyte-CM) were collected and added on MC3T3-E1 cell cultures. MC3T3-E1 cells cultured in LIPUS-Osteocyte-CM demonstrated a significant inhibition of proliferation and an increased alkaline phosphatase activity. The results of PGE(2) and NO assay showed that LIPUS could enhance PGE(2) and NO secretion from MLO-Y4 cells at all time points within 24h after LIPUS stimulation. We conclude that LIPUS regulates proliferation and differentiation of osteoblasts through osteocytes in vitro. Increased secretion of PGE(2) from osteocytes may play a role in this effect. PMID:22266313

  5. Low-intensity pulsed ultrasound regulates proliferation and differentiation of osteoblasts through osteocytes

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lei, E-mail: geraldleelei@163.com [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu (China); Yang, Zheng [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu (China); Zhang, Hai [Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA (United States); Chen, Wenchuan [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu (China); Chen, Mengshi [Department of Biomechanics, Sichuan University, Chengdu (China); Zhu, Zhimin, E-mail: hxzhimin@163.com [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu (China)

    2012-02-10

    Highlights: Black-Right-Pointing-Pointer CM from LIPUS-stimulated osteocytes inhibits proliferation of osteoblasts. Black-Right-Pointing-Pointer CM from LIPUS-stimulated osteocytes enhances differentiation of osteoblasts. Black-Right-Pointing-Pointer LIPUS stimulates MLO-Y4 cells to secrete PGE{sub 2} and NO. -- Abstract: Low-intensity pulsed ultrasound (LIPUS) has been used as a safe and effective modality to enhance fracture healing. As the most abundant cells in bone, osteocytes orchestrate biological activities of effector cells via direct cell-to-cell contacts and by soluble factors. In this study, we have used the osteocytic MLO-Y4 cells to study the effects of conditioned medium from LIPUS-stimulated MLO-Y4 cells on proliferation and differentiation of osteoblastic MC3T3-E1 cells. Conditioned media from LIPUS-stimulated MLO-Y4 cells (LIPUS-Osteocyte-CM) were collected and added on MC3T3-E1 cell cultures. MC3T3-E1 cells cultured in LIPUS-Osteocyte-CM demonstrated a significant inhibition of proliferation and an increased alkaline phosphatase activity. The results of PGE{sub 2} and NO assay showed that LIPUS could enhance PGE{sub 2} and NO secretion from MLO-Y4 cells at all time points within 24 h after LIPUS stimulation. We conclude that LIPUS regulates proliferation and differentiation of osteoblasts through osteocytes in vitro. Increased secretion of PGE{sub 2} from osteocytes may play a role in this effect.

  6. Circular Updates

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Circular Updates are periodic sequentially numbered instructions to debriefing staff and observers informing them of changes or additions to scientific and specimen...

  7. Information circulars

    International Nuclear Information System (INIS)

    The document summarizes the information circulars published by the IAEA for the purpose of bringing matters of general interest to the attention of all Members of the Agency. In the main body of the document only those documents which are regarded as likely to be of current interest are listed. A complete numerical list of information circulars with their titles is reproduced in the Annex

  8. Value of MRI in differentiating adrenal masses: Quantitative analysis of tumor signal intensity

    International Nuclear Information System (INIS)

    Several reports show that MR imaging, especially using the chemical-shift sequence, provides highly reliable differentiation of adrenal adenomas from non-adenomas. The aim of the study was to evaluate the ability of MRI to distinguish adenomas from other adrenal masses using quantitative analysis of the tumors' signal intensity. Fifty-four patients with 57 adrenal masses underwent MRI. The tumors were determined during surgery as pheochromocytomas, metastases, adrenal cortical carcinoma, and adenomas. Nineteen masses were diagnosed as adenomas on the basis of stability on imaging followup and the absence of clinical and endocrinological dysfunction. Chemical-shift-weighted images (T1TFE sequence) and T2-weighted images (TSE sequence) were used for quantitative analysis which included the T2 index (adrenal mass SI to liver SI ratio) and the CSI ratio (the adrenal mass SI on the in-phase image minus the adrenal mass SI on the opposed-phase image divided by the adrenal mass SI on the in-phase image). Statistical analysis was performed with the Mann-Whitney U test. Receiver operating characteristic (ROC) analysis of the calculated parameters was performed. Significant differences in T2 index between adenomas (mean: 1.43±0.50) and pheochromocytomas (2.66±0.67) as well as between metastases (1.64±0.22) and pheochromocytomas were noted (p≤0.05). The Mann-Whitney U test revealed no significant difference in T2 index for adenomas vs. metastases (p=0.1). The CSI ratio was significantly different for adenomas (0.36±0.18) vs. pheochromocytomas (-0.15±0.16) as well as for adenomas vs. metastases (-0.23±0.26). No significant difference occurred in the CSI ratios between pheochromocytomas and metastases. ROC analysis showed that the discriminatory ability of adenoma diagnosis with the CSI ratio is better than with the T2 index (areas under the ROC curve: 0.980 vs. 0.867). Quantitative methods using signal intensity ratios and indexes calculated from MR images are helpful

  9. Ionization of oriented targets by intense circularly polarized laser pulses: Imprints of orbital angular nodes in the two-dimensional momentum distribution

    DEFF Research Database (Denmark)

    Martiny, Christian; Abu-Samha, Mahmoud; Madsen, Lars Bojer

    2010-01-01

    We solve the three-dimensional time-dependent Schrödinger equation for a few-cycle circularly polarized femtosecond laser pulse that interacts with an oriented target exemplified by an argon atom, initially in a 3px or 3py state. The photoelectron momentum distributions show distinct signatures of....... Furthermore, we show that ionization by a circularly polarized pulse completely maps out the angular nodal structure of the initial state, thus providing a potential tool for studying orbital symmetry in individual systems or during chemical reactions....

  10. Sequential attack with intensity modulation on the differential-phase-shift quantum-key-distribution protocol

    International Nuclear Information System (INIS)

    In this paper, we discuss the security of the differential-phase-shift quantum-key-distribution (DPSQKD) protocol by introducing an improved version of the so-called sequential attack, which was originally discussed by Waks et al. [Phys. Rev. A 73, 012344 (2006)]. Our attack differs from the original form of the sequential attack in that the attacker Eve modulates not only the phases but also the amplitude in the superposition of the single-photon states which she sends to the receiver. Concentrating especially on the 'discretized Gaussian' intensity modulation, we show that our attack is more effective than the individual attack, which had been the best attack up to present. As a result of this, the recent experiment with communication distance of 100 km reported by Diamanti et al. [Opt. Express 14, 13073 (2006)] turns out to be insecure. Moreover, it can be shown that in a practical experimental setup which is commonly used today, the communication distance achievable by the DPSQKD protocol is less than 95 km

  11. Circular polarization analyzer with polarization tunable focusing of surface plasmon polaritons

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Sen; Zhang, Yan, E-mail: yzhang@mail.cnu.edu.cn [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); Beijing Key Laboratory for Metamaterials and Devices, and Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, Beijing 100048 (China); Wang, Xinke [Beijing Key Laboratory for Metamaterials and Devices, and Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics, Capital Normal University, Beijing 100048 (China); Kan, Qiang [State Key Laboratory for Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Qu, Shiliang [Optoelectronics Department, Harbin Institute of Technology at Weihai, Weihai 264209 (China)

    2015-12-14

    A practical circular polarization analyzer (CPA) that can selectively focus surface plasmon polaritons (SPPs) at two separate locations, according to the helicity of the circularly polarized light, is designed and experimentally verified in the terahertz frequency range. The CPA consists of fishbone-slit units and is designed using the simulated annealing algorithm. By differentially detecting the intensities of the two SPPs focuses, the helicity of the incident circularly polarized light can be obtained and the CPA is less vulnerable to the noise of incident light. The proposed device may also have wide potential applications in chiral SPPs photonics and the analysis of chiral molecules in biology.

  12. Circular polarization analyzer with polarization tunable focusing of surface plasmon polaritons

    International Nuclear Information System (INIS)

    A practical circular polarization analyzer (CPA) that can selectively focus surface plasmon polaritons (SPPs) at two separate locations, according to the helicity of the circularly polarized light, is designed and experimentally verified in the terahertz frequency range. The CPA consists of fishbone-slit units and is designed using the simulated annealing algorithm. By differentially detecting the intensities of the two SPPs focuses, the helicity of the incident circularly polarized light can be obtained and the CPA is less vulnerable to the noise of incident light. The proposed device may also have wide potential applications in chiral SPPs photonics and the analysis of chiral molecules in biology

  13. Differential Effects of Differing Intensities of Acute Exercise on Speed and Accuracy of Cognition: A Meta-Analytical Investigation

    Science.gov (United States)

    McMorris, Terry; Hale, Beverley J.

    2012-01-01

    The primary purpose of this study was to examine, using meta-analytical techniques, the differential effects of differing intensities of acute exercise on speed and accuracy of cognition. Overall, exercise demonstrated a small, significant mean effect size (g = 0.14, p less than 0.01) on cognition. Examination of the comparison between speed and…

  14. Operational Circulars

    CERN Document Server

    2003-01-01

    Operational Circular N° 4 - April 2003 Conditions for use by members of the CERN personnel of vehicles belonging to or rented by CERN - This circular has been drawn up. Operational Circular N° 5 - October 2000 Use of CERN computing facilities - Further details on the personal use of CERN computing facilities Operational Circular N° 5 and its Subsidiary Rules http://cern.ch/ComputingRules defines the rules for the use of CERN computing facilities. One of the basic principles governing such use is that it must come within the professional duties of the user concerned, as defined by the user's divisional hierarchy. However, personal use of the computing facilities is tolerated or allowed provided : a) It is in compliance with Operational Circular N° 5 and not detrimental to official duties, including those of other users; b) the frequency and duration is limited and there is a negligible use of CERN resources; c) it does not constitute a political, commercial and/or profit-making activity; d) it is not...

  15. Amplifying vibrational circular dichroism by manipulation of the electronic manifold.

    Science.gov (United States)

    Domingos, Sérgio R; Panman, Matthijs R; Bakker, Bert H; Hartl, Frantisek; Buma, Wybren J; Woutersen, Sander

    2012-01-11

    Vibrational circular dichroism is a powerful technique to study the stereochemistry of chiral molecules, but often suffers from small signal intensities. Electrochemical modulation of the energies of the electronically excited state manifold is now demonstrated to lead to an order of magnitude enhancement of the differential absorption. Quantum-chemical calculations show that increased mixing between ground and excited states is at the origin of this amplification. PMID:22002107

  16. Exploration of resistive targets within shallow marine environments using the circular electrical dipole and the differential electrical dipole methods: a time-domain modelling study

    Science.gov (United States)

    Haroon, Amir; Mogilatov, Vladimir; Goldman, Mark; Bergers, Rainer; Tezkan, Bülent

    2016-05-01

    Two novel transient controlled source electromagnetic methods called circular electrical dipole (CED) and differential electrical dipole (DED) are theoretically analysed for applications in shallow marine environments. 1-D and 3-D time-domain modelling studies are used to investigate the detectability and applicability of the methods when investigating resistive layers/targets representing hydrocarbon-saturated formations. The results are compared to the conventional time-domain horizontal electrical dipole (HED) and vertical electrical dipole (VED) sources. The applied theoretical modelling studies demonstrate that CED and DED have higher signal detectability towards resistive targets compared to TD-CSEM, but demonstrate significantly poorer signal amplitudes. Future CED/DED applications will have to solve this issue prior to measuring. Furthermore, the two novel methods have very similar detectability characteristics towards 3-D resistive targets embedded in marine sediments as VED while being less susceptible towards non-verticality. Due to the complex transmitter design of CED/DED the systems are prone to geometrical errors. Modelling studies show that even small transmitter inaccuracies have strong effects on the signal characteristics of CED making an actual marine application difficult at the present time. In contrast, the DED signal is less affected by geometrical errors in comparison to CED and may therefore be more adequate for marine applications.

  17. Differential attenuation imaging for the characterization of high intensity focused ultrasound lesions.

    Science.gov (United States)

    Ribault, M; Chapelon, J Y; Cathignol, D; Gelet, A

    1998-07-01

    High intensity focused ultrasound (HIFU) is an effective technique for creating coagulative necrotic lesions in biological tissue, with a view to treating localized tumors. Although good results have already been obtained, notably in urology, current systems lack a real time monitoring system to check the efficacy of the treatment procedures. This study describes the development and assessment of a noninvasive system for making local measurements of attentuation variations during HIFU treatment procedures. An apparatus (Ablatherm, Edap-Technomed, France), combining a 2.5 MHz therapeutic transducer and a 5.5 MHz twin plane imaging probe (connected to an ultrasound scanner), was used to produce lesions. The rf signals needed to calculate the attenuation were recorded as outputs from the ultrasound scanner, before and after the high intensity firing sequences, which were performed on ten pieces of porcine liver. Each firing sequence involved producing a lesion volume comprising 42 individual lesions. A number of recordings were also made without producing lesions, in order to test the reproducibility of the measurements. The attenuation function was evaluated locally using the centroid and the multinarrowband methods. Initially, changes in the integrated attenuation alpha (mean attenuation in the 4-7 MHz range) and the attenuation slope beta were examined for the lesion volume. beta values did not vary significantly within this range, whereas alpha values varied significantly (in the region of 86% of the initial level) in comparison to measurements performed without forming lesions. The differential attenuation delta alpha (representing local variations in alpha) was subsequently used to generate images revealing the lesion areas. There was a strong similarity between these 'delta alpha images' and the lesion volumes defined by the operator. 'delta alpha images' offer several advantages over existing attenuation imaging techniques. Any problems related to the

  18. Information circulars

    International Nuclear Information System (INIS)

    The document summarizes the Information Circulars published by the IAEA under the symbol INFCIRC/ for the purpose of bringing matters of general interest to the attention of all Members of the Agency. A complete list of INFCIRCs in numerical order with their titles is given in the Annex

  19. ADMINISTRATIVE CIRCULARS

    CERN Multimedia

    Division des ressources humaines

    2000-01-01

    N° 2 (Rev. 1) - March 2000Guidelines and procedures concerning recruitment and probation period of staff membersN° 9 (Rev. 2) - March 2000Staff members contractsN° 16 (Rev. 2) - January 2000TrainingN° 30 (Rev. 1) - January 2000Indemnities and reimbursements upon taking up appointment and termination of contractN° 32 - February 2000Principles and procedures governing complaints of harassmentThese circular have been amended (No 2, N° 9, N° 16 and N° 30) or drawn up (N° 32).Copies are available in the Divisional Secretariats.Note:\tAdministrative and operational circulars, as well as the lists of those in force, are available for consultation in the server SRV4_Home in the Appletalk zone NOVELL (as GUEST or using your Novell username and password), volume PE Division Data Disk.The Word files are available in the folder COM, folder Public, folder ADM.CIRC.docHuman Resources DivisionTel. 74128

  20. Differential pain response at local and remote muscle sites following aerobic cycling exercise at mild and moderate intensity

    OpenAIRE

    Micalos, Peter S.; Arendt-Nielsen, Lars

    2016-01-01

    Physical exercise has been shown to inhibit experimental pain response in the post-exercise period. Modulation of the pain system may be differentiated between muscle sites engaging in contractile activity. The purpose of this study was to assess the pain response at remote and local muscle sites following aerobic exercise at different work intensities. Participants included 10 healthy and physically active males (mean age ± SD, 21.2 ± 3.4). Somatic pressure pain threshold (PPT) at the rectus...

  1. Fractional Differentiation-Based Active Contour Model Driven by Local Intensity Fitting Energy

    OpenAIRE

    Ming Gu; Renfang Wang

    2016-01-01

    A novel active contour model is proposed for segmentation images with inhomogeneity. Firstly, fractional order filter is defined by eight convolution masks corresponding to the image orientation in the eight compass directions. Then, the fractional order differentiation image is obtained and applied to the level set method. Secondly, we defined a new energy functional based on local image information and fractional order differentiation image; the proposed model not only can describe the inpu...

  2. Duration and intensity of shade differentially affects mycorrhizal growth- and phosphorus uptake responses of Medicago truncatula

    Czech Academy of Sciences Publication Activity Database

    Konvalinková, T.; Püschel, David; Janoušková, Martina; Gryndler, M.; Jansa, J.

    2015-01-01

    Roč. 6, FEB 13 (2015), s. 1-11. ISSN 1664-462X Institutional support: RVO:67985939 Keywords : arbuscular mycorrhizal symbiosis * light intensity * shading duration Subject RIV: EE - Microbiology, Virology Impact factor: 3.948, year: 2014

  3. Duration and intensity of shade differentially affects mycorrhizal growth- and phosphorus uptake responses of Medicago truncatula

    Czech Academy of Sciences Publication Activity Database

    Konvalinková, Tereza; Püschel, David; Janoušková, Martina; Gryndler, Milan; Jansa, Jan

    2015-01-01

    Roč. 6, FEB 13 (2015), s. 1-11. ISSN 1664-462X R&D Projects: GA MŠk(CZ) LK11224 Institutional support: RVO:61388971 Keywords : arbuscular mycorrhizal symbiosis * light intensity * shading duration Subject RIV: EE - Microbiology, Virology Impact factor: 3.948, year: 2014

  4. Stress intensity factors for large aspect ratio surface and corner cracks at a semi-circular notch in a tension specimen

    Science.gov (United States)

    Shivakumar, K. N.; Newman, J. C., Jr.

    1991-01-01

    Stress intensity factor solutions for semielliptic surface and quarter-elliptic corner cracks emanating from a semicircular notch in a tension specimen are presented. A three-dimensional finite-element analysis in conjunction with the equivalent domain integral was used to calculate stress intensity factors (SIF). SIF solutions for surface or corner crack (crack length to depth ratio of 2) at a notch are presented for a wide range of crack sizes and notch radii. Results showed that the SIF are larger for larger crack lengths and for larger notch radii. The SIF are nearly constant all along the crack front for deep surface cracks and for all corner cracks analysed.

  5. New optical scheme for differential measurements of diffraction reflection intensity on X-radiation sliding incidence

    International Nuclear Information System (INIS)

    An X-ray optical scheme for differential measurements of X-ray diffraction under sliding incidence conditions is proposed and an attachment design realizng this scheme, using standard equipment, is described. The main feature of the scheme is the following: collimation according to the Bragg angle is carried out for the reflected beam rather than the incident one. Goniometers can be used from DRON, TRS, GS-5 and other spectrometers. The goniometer head carrying the sample is standard, it is a part of the DRON, TRS and DTS. The crystal analyzer is fixed on the attachment. The angular position of the crystal monochromator is controlled by an inductive sensor. The experimental differential curves of X-ray diffraction under conditions of sliding incidence, taken for a silicon crystal having the 111 orientation, are given as well

  6. SPATIAL DIFFERENTIATION AND DROUGHT INTENSITY IN THE UPPER SILESIA REGION, POLAND

    OpenAIRE

    WYPYCH AGNIESZKA; PALARZ ANGELIKA; KUBACKA DANUTA

    2015-01-01

    Drought estimation and monitoring seems to be crucial both in agricultural activities as well as in water management. The aim of the study is to estimate the drought vulnerability of the Upper Silesia Region using selected drought indices. The evaluation was based on daily meteorological data from the period 1981-2010 and conducted for particular administrative units. On the basis of 30-years of observations the spatial distribution of drought phenomena as well as its intensity and duration w...

  7. Are There Differential Effects of Price and Policy on College Students' Drinking Intensity?

    OpenAIRE

    Jenny Williams; Frank J. Chaloupka; Henry Wechsler

    2002-01-01

    This paper investigates whether college students' response to alcohol price and policies differ according to their drinking intensity. Individual level data on drinking behavior, price paid per drink, and college alcohol policies come from the student and administrator components of the 1997 and 1999 waves of the Harvard School of Public Health (HSPH) College Alcohol Study (CAS). Students drinking behavior is classified on the basis of the number of drinks they typically consume on a drinking...

  8. Switchable circular beam deflectors

    Science.gov (United States)

    Shang, Xiaobing; Joshi, Pankaj; Tan, Jin-Yi; De Smet, Jelle; Cuypers, Dieter; Baghdasaryan, Tigran; Vervaeke, Michael; Thienpont, Hugo; De Smet, Herbert

    2016-04-01

    In this work, we report two types of electrically tunable photonic devices with circularly symmetric polarization independent beam steering performance (beam condensing resp. beam broadening). The devices consist of circular micro grating structures combined with nematic liquid crystal (LC) layers with anti-parallel alignment. A single beam deflector converts a polarized and monochromatic green laser beam (λ =543.5 nm) into a diffraction pattern, with the peak intensity appearing at the third order when 0~{{V}\\text{pp}} is applied and at the zeroth order (no deflection) for voltages above 30~{{V}\\text{pp}} . Depending on the shape of the grating structure (non-inverted or inverted), the deflection is inwards or outwards. Both grating types can be made starting from the same diamond-tooled master mold. A polarized white light beam is symmetrically condensed resp. broadened over 2° in the off state and is passed through unchanged in the on state. By stacking two such devices with mutually orthogonal LC alignment layers, polarization independent switchable circular beam deflectors are realized with a high transmittance (>80%), and with the same beam steering performance as the polarization dependent single devices.

  9. Correction of terrestrial LiDAR intensity channel using Oren-Nayar reflectance model: An application to lithological differentiation

    Science.gov (United States)

    Carrea, Dario; Abellan, Antonio; Humair, Florian; Matasci, Battista; Derron, Marc-Henri; Jaboyedoff, Michel

    2016-03-01

    and are independent from range, incidence angle and scanned surface geometry. The corrected intensity values significantly improve the material differentiation.

  10. Differential effect of metabolic alkalosis and hypoxia on high-intensity cycling performance.

    Science.gov (United States)

    Flinn, Samantha; Herbert, Kathryn; Graham, Kenneth; Siegler, Jason C

    2014-10-01

    The purpose of this study was to investigate the effects of sodium bicarbonate (NaHCO3) ingestion and acute hypoxic exposure on repeated bouts of high-intensity cycling to task failure. Twelve subjects completed 4 separate intermittent cycling bouts cycling bouts to task failure (120% peak power output for 30-second interspersed with 30-second active recovery) under the following conditions: normoxia (FIO2% at 20.93%) alkalosis (NA), normoxia placebo (NP), hypoxia (FIO2% at 14.7%) alkalosis (HA), and hypoxia placebo (HP). For the NA and HA trials, the buffer solution (0.3 g·kg of NaHCO3) was dispensed into gelatin capsules and consumed over 90 minutes with 1 L of water. Whole-blood acid-base findings demonstrated metabolic alkalosis in both NA and HA before exercise (HCO3: 32.8 ± 1.8 mmol·L). Time to task failure was significantly impaired in the hypoxic conditions (NA: 199.1 ± 62.3 seconds, NP: 183.8 ± 45.0 seconds, HA: 127.8 ± 27.9 seconds, HP: 133.3 ± 28.7 seconds; p hypoxia and NaHCO3 concurrently to improve performance under these conditions does not seem warranted. PMID:24983849

  11. Differential Salt-Induced Dissociation of the p53 Protein Complexes with Circular and Linear Plasmid DNA Substrates Suggest Involvement of a Sliding Mechanism

    Directory of Open Access Journals (Sweden)

    Peter Šebest

    2015-01-01

    Full Text Available A study of the effects of salt conditions on the association and dissociation of wild type p53 with different ~3 kbp long plasmid DNA substrates (supercoiled, relaxed circular and linear, containing or lacking a specific p53 binding site, p53CON using immunoprecipitation at magnetic beads is presented. Salt concentrations above 200 mM strongly affected association of the p53 protein to any plasmid DNA substrate. Strikingly different behavior was observed when dissociation of pre-formed p53-DNA complexes in increased salt concentrations was studied. While contribution from the p53CON to the stability of the p53-DNA complexes was detected between 100 and 170 mM KCl, p53 complexes with circular DNAs (but not linear exhibited considerable resistance towards salt treatment for KCl concentrations as high as 2 M provided that the p53 basic C-terminal DNA binding site (CTDBS was available for DNA binding. On the contrary, when the CTDBS was blocked by antibody used for immunoprecipitation, all p53-DNA complexes were completely dissociated from the p53 protein in KCl concentrations ≥200 mM under the same conditions. These observations suggest: (a different ways for association and dissociation of the p53-DNA complexes in the presence of the CTDBS; and (b a critical role for a sliding mechanism, mediated by the C-terminal domain, in the dissociation process.

  12. Putative null distributions corresponding to tests of differential expression in the Golden Spike dataset are intensity dependent

    Directory of Open Access Journals (Sweden)

    Gaile Daniel P

    2007-04-01

    Full Text Available Abstract Background We provide a re-analysis of the Golden Spike dataset, a first generation "spike-in" control microarray dataset. The original analysis of the Golden Spike dataset was presented in a manuscript by Choe et al. and raised questions concerning the performance of several statistical methods for the control of the false discovery rate (across a set of tests for differential expression. These original findings are now in question as it has been reported that the p-values associated with the tests of differential expression for null probesets (i.e., probesets designed to be fold change 1 across the two arms of the experiment are not uniformly distributed. Two recent publications have speculated as to the reasons the null distributions are non-uniform. A publication by Dabney and Storey concludes that the non-uniform distributions of null p-values are the direct consequence of an experimental design which requires technical replicates to approximate biological replicates. Irizarry et al. identify four characteristics of the feature level data (three related to experimental design and one artifact. Irizarry et al. argue that the four observed characteristics imply that the assumptions common to most pre-processing algorithms are not satisfied and hence the expression measure methodologies considered by Choe et al. are likely to be flawed. Results We replicate and extend the analyses of Dabney and Storey and present our results in the context of a two stage analysis. We provide evidence that the Stage I pre-processing algorithms considered in Dabney and Storey fail to provide expression values that are adequately centered or scaled. Furthermore, we demonstrate that the distributions of the p-values, test statistics, and probabilities associated with the relative locations and variabilities of the Stage II expression values vary with signal intensity. We provide diagnostic plots and a simple logistic regression based test statistic to

  13. Towards a reliability check for the multi-specimen differential pTRM paleo-intensity method

    International Nuclear Information System (INIS)

    Complete text of publication follows. The multi-specimen differential pTRM paleo-intensity method (Dekkers and Boehnel, 2006, EPSL 248, 507-516) presently lacks a constraint for the selection of the pTRM acquisition temperature. For reliable results (of any paleo-intensity (PI) method) no or very little changes in magnetic state should occur during the experiment. The occurrence of such changes is directly related to the pTRM acquisition temperature (also referred to as set-point temperature) at which the experiment is carried out. It is therefore important to constrain this temperature. This would yield an indication for the reliability of the outcome of the PI experiment independent of the actual result in technical terms. Detecting changes in magnetic state as function of temperature along with thermo-chemical alteration has shown to be not trivial. Various ways have been proposed, including measurement of changes in low-field susceptibility or magnetization as function of temperature, and measurement of the susceptibility or hysteresis properties before and after the PI experiment. While insightful in some ways, these methods gave equivocal results when applying them on a sample set from historic (20th century) lavas from mount Etna, Italy: no alterations were detected after heating at 160 deg C, while the multi-specimen method yielded an underestimate of the PI of about 25% compared to the IGRF. This indicates that very subtle changes in magnetic state, that go undetected by the aforementioned magnetic measurements, do have a large influence on the outcome of the PI method. Here we explore the suitability of ARM acquisition curves to diagnose subtle changes in magnetic state. As is well known, specific ARM intensity varies strongly with magnetic grain size, particularly in the SD grain-size realm. By using the automated SQUID magnetometer with in-line rock magnetic facilities available in the Utrecht paleomagnetic laboratory, high-resolution ARM acquisition

  14. Circularity and Lambda Abstraction

    DEFF Research Database (Denmark)

    Danvy, Olivier; Thiemann, Peter; Zerny, Ian

    2013-01-01

    In this tribute to Doaitse Swierstra, we present the rst transformation between lazy circular programs a la Bird and strict cir- cular programs a la Pettorossi. Circular programs a la Bird rely on lazy recursive binding: they involve circular unknowns and make sense equa- tionally. Circular...... unknowns from what is done to them, which we lambda-abstract with functions. The circular unknowns then become dead variables, which we eliminate. The result is a strict circu- lar program a la Pettorossi. This transformation is reversible: given a strict circular program a la Pettorossi, we introduce...

  15. Circular-rubbing Manipulation

    Institute of Scientific and Technical Information of China (English)

    SHEN Guo-quan; XIAO Yuan-chun

    2003-01-01

    @@ "Mo" literally means "rubbing between two things"and "eliminating". Circular-rubbing is one of the earliest manipulations used in clinical practice. Circular-rubbing differs from pressing actually. Pressing is a static manipulation and acts to inhibit motion; circular-rubbing is a movable manipulation and serves to eliminate stationary. Circular-rubbing can be performed by either the palm or the finger.

  16. Circular trimers of gelatinase B/matrix metalloproteinase-9 constitute a distinct population of functional enzyme molecules differentially regulated by tissue inhibitor of metalloproteinases-1

    DEFF Research Database (Denmark)

    Vandooren, Jennifer; Born, Benjamin; Solomonov, Inna;

    2015-01-01

    knowledge about the overall structure of proMMP-9 monomers and multimers is limited. We investigated biochemical, biophysical and functional characteristics of zymogen and activated forms of MMP-9 monomers and multimers. In contrast with a conventional notion of a dimeric nature of MMP-9 homomultimers, we...... in a higher extent of TIMP-1 inhibition of angiogenesis induced by trimers compared with monomers. Our results show that proMMP-9 trimers constitute a novel structural and functional entity that is differentially regulated by TIMP-1....

  17. PUBLICATION OF ADMINISTRATIVE CIRCULAR

    CERN Multimedia

    HR Department

    2008-01-01

    ADMINISTRATIVE CIRCULAR NO. 23 (REV. 2) – SPECIAL WORKING HOURS Administrative Circular No. 23 (Rev. 2) entitled "Special working hours", approved following discussion in the Standing Concertation Committee meeting of 9 December 2008, will be available on the intranet site of the Human Resources Department as from 19 December 2008: http://cern.ch/hr-docs/admincirc/admincirc.asp It cancels and replaces Administrative Circular No. 23 (Rev. 1) entitled "Stand-by duty" of April 1988. A "Frequently Asked Questions" information document on special working hours will also be available on this site. Paper copies of this circular will shortly be available in departmental secretariats. Human Resources Department Tel. 78003

  18. Publication of administrative circular

    CERN Multimedia

    HR Department

    2009-01-01

    ADMINISTRATIVE CIRCULAR NO. 23 (REV. 2) – SPECIAL WORKING HOURS Administrative Circular No. 23 (Rev. 2) entitled "Special working hours", approved following discussion in the Standing Concertation Committee on 9 December 2008, will be available on the intranet site of the Human Resources Department as from 19 December 2008: http://cern.ch/hr-docs/admincirc/admincirc.asp It cancels and replaces Administrative Circular No. 23 (Rev. 1) entitled "Stand-by duty" of April 1988. A "Frequently Asked Questions" information document on special working hours will also be available on this site. Paper copies of this circular will shortly be available in Departmental Secretariats. Human Resources Department Tel. 78003

  19. Toroidal circular dichroism

    Science.gov (United States)

    Raybould, T. A.; Fedotov, V. A.; Papasimakis, N.; Kuprov, I.; Youngs, I. J.; Chen, W. T.; Tsai, D. P.; Zheludev, N. I.

    2016-07-01

    We demonstrate that the induced toroidal dipole, represented by currents flowing on the surface of a torus, makes a distinct and indispensable contribution to circular dichroism. We show that toroidal circular dichroism supplements the well-known mechanism involving electric dipole and magnetic dipole transitions. We illustrate this with rigorous analysis of the experimentally measured polarization-sensitive transmission spectra of an artificial metamaterial, constructed from elements of toroidal symmetry. We argue that toroidal circular dichroism will be found in large biomolecules with elements of toroidal symmetry and should be taken into account in the interpretation of circular dichroism spectra of organics.

  20. Nanoconfined circular and linear DNA - equilibrium conformations and unfolding kinetics

    CERN Document Server

    Alizadehheidari, M; Noble, C; Reiter-Schad, M; Nyberg, L K; Fritzsche, J; Mehlig, B; Tegenfeldt, J O; Ambjörnsson, T; Persson, F; Westerlund, F

    2016-01-01

    Studies of circular DNA confined to nanofluidic channels are relevant both from a fundamental polymer-physics perspective and due to the importance of circular DNA molecules in vivo. We here observe the unfolding of DNA from the circular to linear configuration as a light-induced double strand break occurs, characterize the dynamics, and compare the equilibrium conformational statistics of linear and circular configurations. This is important because it allows us to determine to which extent existing statistical theories describe the extension of confined circular DNA. We find that the ratio of the extensions of confined linear and circular DNA configurations increases as the buffer concentration decreases. The experimental results fall between theoretical predictions for the extended de Gennes regime at weaker confinement and the Odijk regime at stronger confinement. We show that it is possible to directly distinguish between circular and linear DNA molecules by measuring the emission intensity from the DNA....

  1. The Circular Camera Movement

    DEFF Research Database (Denmark)

    Hansen, Lennard Højbjerg

    2014-01-01

    It has been an accepted precept in film theory that specific stylistic features do not express specific content. Nevertheless, it is possible to find many examples in the history of film in which stylistic features do express specific content: for instance, the circular camera movement is used...... circular camera movement. Keywords: embodied perception, embodied style, explicit narration, interpretation, style pattern, television style...

  2. Perfect Circular Dichroic Metamirrors

    CERN Document Server

    Wang, Zuojia; Liu, Yongmin

    2015-01-01

    In nature, the beetle Chrysina gloriosa derives its iridescence by selectively reflecting left-handed circularly polarized light only. Here, for the first time, we introduce and demonstrate the optical analogue based on an ultrathin metamaterial, which we term circular dichroic metamirror. A general method to design the circular dichroic metasmirror is presented under the framework of Jones calculus. It is analytically shown that the metamirror can be realized by two layers of anisotropic metamaterial structures, in order to satisfy the required simultaneous breakings of n-fold rotational (n>2) and mirror symmetries. We design an infrared metamirror, which shows perfect reflectance for left-handed circularly polarized light without reversing its handedness, while almost completely absorbs right-handed circularly polarized light. These findings offer new methodology to realize novel chiral optical devices for a variety of applications, including polarimetric imaging, molecular spectroscopy, as well as quantum ...

  3. Polarimetric investigation of materials with both linear and circular anisotropy

    DEFF Research Database (Denmark)

    Naydenova, I.; Nikolova, L.; Todorov, T.; Andruzzi, F.; Hvilsted, Søren; Ramanujam, P.S.

    1997-01-01

    We investigate light propagation through materials with both linear and circular anisotropy and find the relation of the amplitude and polarization transfer functions to the four anisotropic characteristics: linear circular birefringence, and linear and circular dichroism. We determine these four...... characteristics of anisotropic samples by measuring the output intensity and polarization corresponding to different input polarization azimuths and fitting the theoretical and experimental results. In our experiments we have used films of side-chain azobenzene polyesters in which optical anisotropy had been...

  4. Circular statistics in R

    CERN Document Server

    Pewsey, Arthur; Ruxton, Graeme D

    2013-01-01

    Circular Statistics in R provides the most comprehensive guide to the analysis of circular data in over a decade. Circular data arise in many scientific contexts whether it be angular directions such as: observed compass directions of departure of radio-collared migratory birds from a release point; bond angles measured in different molecules; wind directions at different times of year at a wind farm; direction of stress-fractures in concretebridge supports; longitudes of earthquake epicentres or seasonal and daily activity patterns, for example: data on the times of day at which animals are c

  5. Effect of Exercise Intensity on Differentiated and Undifferentiated Ratings of Perceived Exertion During Cycle and Treadmill Exercise in Recreationally Active and Trained Women

    OpenAIRE

    Bolgar, Melinda R.; Carol E. Baker; Goss, Fredric L.; Elizabeth Nagle; Robert J. Robertson

    2010-01-01

    The purpose of the study is to examine the effect of aerobic exercise intensity on components of the differentiated perceived exertion model in young women performing weight bearing and non-weight bearing aerobic exercise. Subjects were 18-25 yr old women who were recreationally active (n = 19; VO2max = 33.40 ml·kg-1·min-1) and trained (N = 22; VO2max = 43.3 ml·kg-1·min-1). Subjects underwent two graded exercise tests (GXT) on a treadmill and bike which were separated by 48 hours. RPE-Overall...

  6. Circular depolarization ratios of single water droplets and finite ice circular cylinders: a modeling study

    Directory of Open Access Journals (Sweden)

    M. Nicolet

    2011-11-01

    Full Text Available Computations of the phase matrix elements for single water droplets and ice crystals in fixed orientations are presented to determine if circular depolarization δ±C is more accurate than linear depolarization for phase discrimination. T-matrix simulations were performed to calculate right-handed and left-handed circular depolarization ratios δ+C, respectively δ−C and to compare them with linear ones. Ice crystals are assumed to have a circular cylindrical shape where their surface-equivalent diameters range up to 5 μm. The circular depolarization ratios of ice particles were generally higher than linear depolarization and depended mostly on the particle orientation as well as their sizes. The fraction of non-detectable ice crystals (δ < 0.05 was smaller considering a circular polarized light source, reaching 4.5%. However, water droplets also depolarized light circularly for scattering angles smaller than 179° and size parameters smaller than 6 at side- and backscattering regions. Differentiation between ice crystals and water droplets might be difficult for experiments performing at backscattering angles which deviate from 180° unlike lidar applications. If the absence of the liquid phase is confirmed, the use of circular depolarization in single particle detection is more sensitive and less affected by particle orientation.

  7. Apoptotic cell death during Drosophila oogenesis is differentially increased by electromagnetic radiation depending on modulation, intensity and duration of exposure.

    Science.gov (United States)

    Sagioglou, Niki E; Manta, Areti K; Giannarakis, Ioannis K; Skouroliakou, Aikaterini S; Margaritis, Lukas H

    2016-01-01

    Present generations are being repeatedly exposed to different types and doses of non-ionizing radiation (NIR) from wireless technologies (FM radio, TETRA and TV stations, GSM and UMTS phones/base stations, Wi-Fi networks, DECT phones). Although there is controversy on the published data regarding the non-thermal effects of NIR, studies have convincingly demonstrated bioeffects. Their results indicate that modulation, intensity, exposure duration and model system are important factors determining the biological response to irradiation. Attempting to address the dependence of NIR bioeffectiveness on these factors, apoptosis in the model biological system Drosophila melanogaster was studied under different exposure protocols. A signal generator was used operating alternatively under Continuous Wave (CW) or Frequency Modulation (FM) emission modes, at three power output values (10 dB, 0, -10 dB), under four carrier frequencies (100, 395, 682, 900 MHz). Newly emerged flies were exposed either acutely (6 min or 60 min on the 6th day), or repeatedly (6 min or 60 min daily for the first 6 days of their life). All exposure protocols resulted in an increase of apoptotic cell death (ACD) observed in egg chambers, even at very low electric field strengths. FM waves seem to have a stronger effect in ACD than continuous waves. Regarding intensity and temporal exposure pattern, EMF-biological tissue interaction is not linear in response. Intensity threshold for the induction of biological effects depends on frequency, modulation and temporal exposure pattern with unknown so far mechanisms. Given this complexity, translating such experimental data into possible human exposure guidelines is yet arbitrary. PMID:25333897

  8. Crop rotation as a factor differentiating the intensity of the diseases of field pea (Pisum sativum L.)

    OpenAIRE

    Tomasz P. Kurowski; Bożena Cwalina-Ambroziak; Tadeusz Sadowski

    2013-01-01

    The research was conducted in the years 1998-2001. The aim of the research was to determine the health of the field pea cv. Kormoran grown in four various crop rotations and to determine the patogens causing the root-rot. On the pea plants the following diseases were found: root rot (complex of fungi), ascochyta blight (Ascochyta pisi, Phoma pinodella, Mycospaerella pinodes) and fusarium foot rot (Fusarium spp.). All the diseases occurred in the highest intensity on the pea cultivated in thre...

  9. Compact waveguide circular polarizer

    Energy Technology Data Exchange (ETDEWEB)

    Tantawi, Sami G.

    2016-08-16

    A multi-port waveguide is provided having a rectangular waveguide that includes a Y-shape structure with first top arm having a first rectangular waveguide port, a second top arm with second rectangular waveguide port, and a base arm with a third rectangular waveguide port for supporting a TE.sub.10 mode and a TE.sub.20 mode, where the end of the third rectangular waveguide port includes rounded edges that are parallel to a z-axis of the waveguide, a circular waveguide having a circular waveguide port for supporting a left hand and a right hand circular polarization TE.sub.11 mode and is coupled to a base arm broad wall, and a matching feature disposed on the base arm broad wall opposite of the circular waveguide for terminating the third rectangular waveguide port, where the first rectangular waveguide port, the second rectangular waveguide port and the circular waveguide port are capable of supporting 4-modes of operation.

  10. Crop rotation as a factor differentiating the intensity of the diseases of field pea (Pisum sativum L.

    Directory of Open Access Journals (Sweden)

    Tomasz P. Kurowski

    2013-12-01

    Full Text Available The research was conducted in the years 1998-2001. The aim of the research was to determine the health of the field pea cv. Kormoran grown in four various crop rotations and to determine the patogens causing the root-rot. On the pea plants the following diseases were found: root rot (complex of fungi, ascochyta blight (Ascochyta pisi, Phoma pinodella, Mycospaerella pinodes and fusarium foot rot (Fusarium spp.. All the diseases occurred in the highest intensity on the pea cultivated in three-field crop rotation without manure. The weather conditions affected the intensity of the diseases. From the roots of seedlings with the symptoms of root rot 44,7% of fungi with pathogenic potential in relation to pea were obtained. The most commonly isolated were Fusarium oxysporum (26,7% of all isolates, Rhizoctonia solani (10,7%, F.solani (3,3%, F.avenaceum (2,7% and F.equiseti (1,3%. From the infected root necks, 55,3% of potential pathogens of field pea were obtained. Among the isolates the most commonly found was F.oxysporum (31,1% of all isolates. Other fungi of the Fusarium genus constituted 15,4% of isolates, R.solani 7,0%, and Sclerotinia sclerotiorum 1,8%.

  11. Differential pain response at local and remote muscle sites following aerobic cycling exercise at mild and moderate intensity

    DEFF Research Database (Denmark)

    Micalos, Peter S.; Arendt-Nielsen, Lars

    2016-01-01

    following aerobic exercise at different work intensities. Participants included 10 healthy and physically active males (mean age ± SD, 21.2 ± 3.4). Somatic pressure pain threshold (PPT) at the rectus femoris (local) and brachioradialis (remote) muscle site was measured at before (Pre), 5 min after (Post1......), and 15 min after (Post2) aerobic cycling exercise at 70 and 30 % of peak oxygen uptake (VO2peak) performed on different occasions in a counterbalanced order, separated by minimum of 3 days interval. Repeated measures ANOVA for PPT reveals significant main effect for time (f = 3.581, p = 0.......049, observed power = 0.588) and muscle site (f = 17.931, p = 0.002, observed power = 0.963). There was a significant interaction shown for exercise intensity by time (f = 11.390, p = 0.012, observed power = 0.790). PPT at rectus femoris following cycling exercise at 70 % of VO2peak reveals a significant...

  12. EFFECT OF EXERCISE INTENSITY ON DIFFERENTIATED AND UNDIFFERENTIATED RATINGS OF PERCEIVED EXERTION DURING CYCLE AND TREADMILL EXERCISE IN RECREATIONALLY ACTIVE AND TRAINED WOMEN

    Directory of Open Access Journals (Sweden)

    Melinda R. Bolgar

    2010-12-01

    Full Text Available The purpose of the study is to examine the effect of aerobic exercise intensity on components of the differentiated perceived exertion model in young women performing weight bearing and non-weight bearing aerobic exercise. Subjects were 18-25 yr old women who were recreationally active (n = 19; VO2max = 33.40 ml·kg-1·min-1 and trained (N = 22; VO2max = 43.3 ml·kg-1·min-1. Subjects underwent two graded exercise tests (GXT on a treadmill and bike which were separated by 48 hours. RPE-Overall, -Legs, and -Chest, as well as oxygen uptake (VO2 and heart rate were recorded each minute. Individual regression analyses were used to identify RPE-Overall,-Legs, and -Chest at 40, 60, 80% VO2max/peak. Separate two factor (site (3 x intensity (3 ANOVAs with repeated measures on site and intensity were computed for each training status. Furthermore, RPE responses were also examined with a one factor (site (3 within subject ANOVA with repeated measure on site at the ventilatory breakpoint. For both the recreationally active and trained groups no significant differences were observed for RPE-Overall, -Legs, and -Chest during treadmill exercise. However, for cycling exercise results indicated that RPE-Legs was significantly greater at all exercise intensities than RPE-Overall and RPE-Chest for trained subjects while for recreationally active subjects RPE-Legs was only significantly higher at the highest exercise intensity. Responses at the ventilatory breakpoint during cycle exercise indicated that RPE-Legs was significantly greater than RPE-Chest and RPE-Overall for trained subjects but not for recreationally active subjects. Signal dominance was not observed at an intensity equivalent to the ventilatory breakpoint during treadmill exercise in either of the groups. In recreationally active and trained females signal dominance was demonstrated only during cycling exercise, but not during treadmill exercise. Signal integration could not be demonstrated during

  13. Wiimote Experiments: Circular Motion

    Science.gov (United States)

    Kouh, Minjoon; Holz, Danielle; Kawam, Alae; Lamont, Mary

    2013-01-01

    The advent of new sensor technologies can provide new ways of exploring fundamental physics. In this paper, we show how a Wiimote, which is a handheld remote controller for the Nintendo Wii video game system with an accelerometer, can be used to study the dynamics of circular motion with a very simple setup such as an old record player or a…

  14. Circular depolarization ratios of single water droplets and finite ice circular cylinders: a modeling study

    Directory of Open Access Journals (Sweden)

    M. Nicolet

    2012-05-01

    Full Text Available Computations of the phase matrix elements for single water droplets and ice crystals in fixed orientations are presented to determine if circular depolarization δC is more accurate than linear depolarization for phase discrimination. T-matrix simulations were performed to calculate right-handed and left-handed circular depolarization ratios δ+C, respectively δ−C and to compare them with linear ones. Ice crystals are assumed to have a circular cylindrical shape where their surface-equivalent diameters range up to 5 μm. The circular depolarization ratios of ice particles were generally higher than linear depolarization and depended mostly on the particle orientation as well as their sizes. The fraction of non-detectable ice crystals (δ<0.05 was smaller considering a circular polarized light source, reaching 4.5%. However, water droplets also depolarized light circularly for scattering angles smaller than 179° and size parameters smaller than 6 at side- and backscattering regions. Differentiation between ice crystals and water droplets might be difficult for experiments performed at backscattering angles which deviate from 180° unlike LIDAR applications. Instruments exploiting the difference in the P44/P11 ratio at a scattering angle around 115° are significantly constrained in distinguishing between water and ice because small droplets with size parameters between 5 and 10 do cause very high circular depolarizations at this angle. If the absence of the liquid phase is confirmed, the use of circular depolarization in single particle detection is more sensitive and less affected by particle orientation.

  15. The Nonlinear Instability Modes of Dished Shallow Shells under Circular Line Loads

    OpenAIRE

    Liu Chang-Jiang; Zheng Zhou-Lian; Huang Cong-Bing; He Xiao-Ting; Sun Jun-Yi; Chen Shan-Lin

    2011-01-01

    This paper investigated the nonlinear stability problem of dished shallow shells under circular line loads. We derived the dimensionless governing differential equations of dished shallow shell under circular line loads according to the nonlinear theory of plates and shells and solved the governing differential equations by combing the free-parameter perturbation method (FPPM) with spline function method (SFM) to analyze the nonlinear instability modes of dished shallow shell under circular l...

  16. Combination of signal intensity measurements of lesions in the peripheral zone of prostate with MRI and serum PSA level for differentiating benign disease from prostate cancer

    International Nuclear Information System (INIS)

    The aim of this study was to predict the benign or malignant nature of a prostatic lesion by defining a threshold value of signal intensity ratio and a limiting value of serum prostate-specific antigen (PSA) in patients with elevated PSA level. Twenty-six patients with elevated PSA level and no hypoechogenic lesions at endosonography underwent MR imaging using an endorectal body phased-array coil at 1.5 T (Siemens Magnetom Symphony). A T2-weighted turbo-spin-echo (TSE) pulse sequence was applied in a transverse orientation. Two radiologists evaluated the images. In the presence of a pathological finding they defined regions of interest (ROI) in the suspicious pathological area of the peripheral zone and in muscle for reference. The quotient of the two ROIs was calculated and then correlated with the actual PSA level. Diagnosis was confirmed by prostate biopsy. Ten of 12 patients with quotients smaller than 4 showed cancer at histology. Nine of 12 men with cancer proven by biopsy had PSA levels higher than 10 ng/ml. A significant difference (p < 0.001) was found between the quotients of cancer and quotients of chronic prostatitis, fibrosis, or glandular atrophy. The accuracy of tumor differentiation of the method was 77 %. Measurement of signal intensity quotients in the peripheral zone of the prostate in combination with knowledge of defined limits of PSA levels the technique could be helpful in detecting additional cancer areas for prostate biopsy. False-negative tumor results of standard sextant biopsy can be reduced. In men with high PSA values the method has a role in differentiating between patients who require prostate biopsy and those of clinical observation. (orig.)

  17. Usefulness of perfusion weighted magnetic resonance imaging with signal-intensity curves analysis in the differential diagnosis of sellar and parasellar tumors: Preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Bladowska, Joanna, E-mail: asia.bladowska@gmail.com [Department of General Radiology, Interventional Radiology and Neuroradiology, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Zimny, Anna, E-mail: abernac@wp.pl [Department of General Radiology, Interventional Radiology and Neuroradiology, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Guziński, Maciej, E-mail: guziol@wp.pl [Department of General Radiology, Interventional Radiology and Neuroradiology, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Hałoń, Agnieszka, E-mail: ahalon2@gmail.com [Department of Pathomorphology and Oncological Cytology, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Tabakow, Paweł, E-mail: p.tabakov@wp.pl [Department of Neurosurgery, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Czyż, Marcin, E-mail: mt.czyz@gmail.com [Department of Neurosurgery, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Czapiga, Bogdan, E-mail: bogdanczapiga@op.pl [Department of Neurosurgery, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Jarmundowicz, Włodzimierz, E-mail: jarmund@wp.pl [Department of Neurosurgery, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Sąsiadek, Marek J., E-mail: marek.sasiadek@am.wroc.pl [Department of General Radiology, Interventional Radiology and Neuroradiology, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland)

    2013-08-15

    Purpose: The most common pituitary tumors are adenomas, which however may be mimicked by other tumors that can show a very similar appearance in plain MRI. The aim of our study was to evaluate the usefulness of perfusion weighted MR imaging (PWI), including signal-intensity curves analysis in the differential diagnosis of sellar/parasellar tumors. Methods: Forty-one patients with sellar/parasellar tumors (23 macroadenomas, 10 meningiomas, 5 craniopharyngiomas, 1 intrasellar hemangioblastoma, 1 intrasellar prostate cancer metastasis, 1 suprasellar glioma), underwent plain MRI followed by PWI using a 1.5T unit. In each tumor, the mean and maximum values of relative cerebral blood volume (rCBV), as well as the relative peak height (rPH) and the relative percentage of signal intensity recovery (rPSR) were calculated. Results: The high perfusion tumors were: macroadenomas, meningiomas, squamous-papillary type of craniopharyngiomas, hemangioblastoma, glioma and metastasis. The low perfusion neoplasms included adamantinomatous type of craniopharyngiomas. By comparing adenomas and meningiomas, we found statistically significant differences in the mean and maximum rCBV values (p = 0.026 and p = 0.019, respectively), but not in rPH and rPSR. The maximum rCBV values >7.14 and the mean rCBV values >5.74 with the typical perfusion curve were very suggestive of the diagnosis of meningioma. There were differences between adenomas and other high perfusion tumors in rPH and rPSR values. Conclusions: PWI can provide additional information helpful in differential diagnosis of sellar/parasellar tumors. In our opinion PWI, as an easy to perform and fast technique should be incorporated into the MR protocol of all intracranial neoplasms including sellar/parasellar tumors.

  18. Usefulness of perfusion weighted magnetic resonance imaging with signal-intensity curves analysis in the differential diagnosis of sellar and parasellar tumors: Preliminary report

    International Nuclear Information System (INIS)

    Purpose: The most common pituitary tumors are adenomas, which however may be mimicked by other tumors that can show a very similar appearance in plain MRI. The aim of our study was to evaluate the usefulness of perfusion weighted MR imaging (PWI), including signal-intensity curves analysis in the differential diagnosis of sellar/parasellar tumors. Methods: Forty-one patients with sellar/parasellar tumors (23 macroadenomas, 10 meningiomas, 5 craniopharyngiomas, 1 intrasellar hemangioblastoma, 1 intrasellar prostate cancer metastasis, 1 suprasellar glioma), underwent plain MRI followed by PWI using a 1.5T unit. In each tumor, the mean and maximum values of relative cerebral blood volume (rCBV), as well as the relative peak height (rPH) and the relative percentage of signal intensity recovery (rPSR) were calculated. Results: The high perfusion tumors were: macroadenomas, meningiomas, squamous-papillary type of craniopharyngiomas, hemangioblastoma, glioma and metastasis. The low perfusion neoplasms included adamantinomatous type of craniopharyngiomas. By comparing adenomas and meningiomas, we found statistically significant differences in the mean and maximum rCBV values (p = 0.026 and p = 0.019, respectively), but not in rPH and rPSR. The maximum rCBV values >7.14 and the mean rCBV values >5.74 with the typical perfusion curve were very suggestive of the diagnosis of meningioma. There were differences between adenomas and other high perfusion tumors in rPH and rPSR values. Conclusions: PWI can provide additional information helpful in differential diagnosis of sellar/parasellar tumors. In our opinion PWI, as an easy to perform and fast technique should be incorporated into the MR protocol of all intracranial neoplasms including sellar/parasellar tumors

  19. TRAJECTORY GENERATION AND CONTROL FOR NON-CIRCULAR CNC TURNING

    Institute of Scientific and Technical Information of China (English)

    JIANG Simin; YAN Han; WANG Xiankui

    2008-01-01

    A trajectory generation method which is based on NURBS interpolation is studied to improve the fitting accuracy and smoothness of non-circular cross section and obtain higher accuracy of the final non-circular profile control. After using the NURBS, the most optimized and smooth trajectory for the linear actuator can be obtained. For the purpose of machining the non-circular cross section by CNC turning, the fast response linear actuator has been used. The control algorithm which is compound control of proportional-integral-differential (PID) and iterative learning control has been developed for non-circular profile generation. By using the NURBS interpolation and the compound control of PID and iterative learning control, the final motion accuracy of linear actuator has been improved, therefore, the machining accuracy of the non-circular turning can be improved.

  20. MR imaging differentiation of malignant soft tissue tumors from peripheral schwannomas with large size and heterogeneous signal intensity

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhaohui, E-mail: zzh_zs@qq.com [Department of Medical Imaging, The First Affiliated Hospital of Sun Yat-sen University, 58 Zhongshan 2nd Road, Guangzhou, Guangdong 510080 (China); Deng, Lei [Department of Radiology, Dongguan People' s Hospital, 3 Wandao Road, Dongguan, Guangdong 52300 (China); Ding, Lei; Meng, Quanfei [Department of Medical Imaging, The First Affiliated Hospital of Sun Yat-sen University, 58 Zhongshan 2nd Road, Guangzhou, Guangdong 510080 (China)

    2015-05-15

    Highlights: • Soft tissue sarcomas can be distinguished from large schwannomas on MR imaging. • Presence of split fat sign and bright rim sign favors the diagnosis of schwannoma. • Absence of lobular shape and extensive edema is also favorable to schwannoma. • Capsule is unreliable in distinguishing soft tissue sarcomas from schwannomas. - Abstract: Objective: To determine the value of MR imaging features at and near the margin of the tumor in differentiating peripheral schwannomas with large size (maximum diameter >5 cm) and heterogeneous appearance from malignant soft tissue tumors (MSTTs). Materials and methods: We retrospectively reviewed MR images of 25 MSTTs and 15 peripheral schwannomas with heterogeneous appearance on MR imaging and maximum diameter ranged from 5 cm to 11 cm. The soft tissue masses were evaluated for split fat sign, bright rim sign, lobular shape (with two or more deep lobulations), peritumoral edema, and capsule. The Fisher's exact test was used to determine whether these imaging features differed significantly between schwannomas and MSTTs. A nonparametric Mann–Whitney test was used to compare the maximal extent of peritumoral edema of schwannomas and MSTTs. The optimal cutoff value of the maximal extent of peritumoral edema was calculated by means of receiver operating characteristic analysis for distinguishing between schwannomas and MSTTs. Interobserver agreement in the assessment of imaging features was evaluated using Cohen κ statistic and percentage agreement. Results: The split fat sign, bright rim sign were more common in schwannomas than in MSTTs (P < 0.001). The incidence of lobular shape was higher for MSTTs than for schwannomas (P < 0.001). The peritumoral edema was present more frequently in MSTTs than in schwannomas (P = 0.001). The median (interquartile range) of the maximal peritumoral edema extent was 13 mm (9.5–17 mm) for schwannomas and 46 mm (24–75.5 mm) for MSTTs, respectively (P < 0.001). The

  1. MR imaging differentiation of malignant soft tissue tumors from peripheral schwannomas with large size and heterogeneous signal intensity

    International Nuclear Information System (INIS)

    Highlights: • Soft tissue sarcomas can be distinguished from large schwannomas on MR imaging. • Presence of split fat sign and bright rim sign favors the diagnosis of schwannoma. • Absence of lobular shape and extensive edema is also favorable to schwannoma. • Capsule is unreliable in distinguishing soft tissue sarcomas from schwannomas. - Abstract: Objective: To determine the value of MR imaging features at and near the margin of the tumor in differentiating peripheral schwannomas with large size (maximum diameter >5 cm) and heterogeneous appearance from malignant soft tissue tumors (MSTTs). Materials and methods: We retrospectively reviewed MR images of 25 MSTTs and 15 peripheral schwannomas with heterogeneous appearance on MR imaging and maximum diameter ranged from 5 cm to 11 cm. The soft tissue masses were evaluated for split fat sign, bright rim sign, lobular shape (with two or more deep lobulations), peritumoral edema, and capsule. The Fisher's exact test was used to determine whether these imaging features differed significantly between schwannomas and MSTTs. A nonparametric Mann–Whitney test was used to compare the maximal extent of peritumoral edema of schwannomas and MSTTs. The optimal cutoff value of the maximal extent of peritumoral edema was calculated by means of receiver operating characteristic analysis for distinguishing between schwannomas and MSTTs. Interobserver agreement in the assessment of imaging features was evaluated using Cohen κ statistic and percentage agreement. Results: The split fat sign, bright rim sign were more common in schwannomas than in MSTTs (P < 0.001). The incidence of lobular shape was higher for MSTTs than for schwannomas (P < 0.001). The peritumoral edema was present more frequently in MSTTs than in schwannomas (P = 0.001). The median (interquartile range) of the maximal peritumoral edema extent was 13 mm (9.5–17 mm) for schwannomas and 46 mm (24–75.5 mm) for MSTTs, respectively (P < 0.001). The

  2. Enhancement of osteogenic differentiation and proliferation in human mesenchymal stem cells by a modified low intensity ultrasound stimulation under simulated microgravity.

    Directory of Open Access Journals (Sweden)

    Sardar M Z Uddin

    Full Text Available Adult stem cells can differentiate into multiple lineages depending on their exposure to differing biochemical and biomechanical inductive factors. Lack of mechanical signals due to disuse can inhibit osteogenesis and induce adipogenesis of mesenchymal stem cells (MSCs. Long-term bed rest due to both brain/spinal cord injury and space travel can lead to disuse osteoporosis that is in part caused by a reduced number of osteoblasts. Thus, it is essential to provide proper mechanical stimulation for cellular viability and osteogenesis, particularly under disuse conditions. The objective of this study was to examine the effects of low intensity pulsed ultrasound (LIPUS on the osteogenic differentiation of adipose-derived human stem cells (Ad-hMSC in simulated microgravity conditions. Cells were cultured in a 1D clinostat to simulate microgravity (SMG and treated with LIPUS at 30mW/cm(2 for 20 min/day. It was hypothesized that the application of LIPUS to SMG cultures would restore osteogenesis in Ad-hMSCs. The results showed significant increases in ALP, OSX, RANKL, RUNX2, and decreases in OPG in LIPUS treated SMG cultures of Ad-MSC compared to non-treated cultures. LIPUS also restored OSX, RUNX2 and RANKL expression in osteoblast cells. SMG significantly reduced ALP positive cells by 70% (p<0.01 and ALP activity by 22% (p<0.01, while LIPUS treatment restored ALP positive cell number and activity to equivalence with normal gravity controls. Extracellular matrix collagen and mineralization was assessed by Sirius red and Alizarin red staining, respectively. SMG cultures showed little or no collagen or mineralization, but LIPUS treatment restored collagen content to 50% (p<0.001 and mineralization by 45% (p<0.001 in LIPUS treated-SMG cultures relative to SMG-only cultures. The data suggest that LIPUS treatment can restore normal osteogenic differentiation of MSCs from disuse by daily short duration stimulation.

  3. Circularity-Measuring System

    Science.gov (United States)

    WHIPPO. WALTER B.; Rohrkaste, G. R.; Miller, John E.

    1989-01-01

    Shape gauge and associated computer constitute system measuring deviations of large cylinders from roundness. Shaped and held somewhat like crossbow, measures relative locations of three points on surface of large, round object. By making connected series of measurements around periphery technician using gauge determines deviation of object from perfect circularity. Used to measure straightness, roundness, or complicated shapes of such large geometrical objects as surfaces of aircraft and hulls of ships.

  4. SIMULTANEOUS MEASUREMENT OF CIRCULAR DICHROISM AND FLUORESCENCE POLARIZATION ANISOTROPY.

    Energy Technology Data Exchange (ETDEWEB)

    SUTHERLAND,J.C.

    2002-01-19

    Circular dichroism and fluorescence polarization anisotropy are important tools for characterizing biomolecular systems. Both are used extensively in kinetic experiments involving stopped- or continuous flow systems as well as titrations and steady-state spectroscopy. This paper presents the theory for determining circular dichroism and fluorescence polarization anisotropy simultaneously, thus insuring the two parameters are recorded under exactly the same conditions and at exactly the same time in kinetic experiments. The approach to measuring circular dichroism is that used in almost all conventional dichrographs. Two arrangements for measuring fluorescence polarization anisotropy are described. One uses a single fluorescence detector and signal processing with a lock-in amplifier that is similar to the measurement of circular dichroism. The second approach uses classic ''T'' format detection optics, and thus can be used with conventional photon-counting detection electronics. Simple extensions permit the simultaneous measurement of the absorption and excitation intensity corrected fluorescence intensity.

  5. Circular arc structures

    KAUST Repository

    Bo, Pengbo

    2011-07-01

    The most important guiding principle in computational methods for freeform architecture is the balance between cost efficiency on the one hand, and adherence to the design intent on the other. Key issues are the simplicity of supporting and connecting elements as well as repetition of costly parts. This paper proposes so-called circular arc structures as a means to faithfully realize freeform designs without giving up smooth appearance. In contrast to non-smooth meshes with straight edges where geometric complexity is concentrated in the nodes, we stay with smooth surfaces and rather distribute complexity in a uniform way by allowing edges in the shape of circular arcs. We are able to achieve the simplest possible shape of nodes without interfering with known panel optimization algorithms. We study remarkable special cases of circular arc structures which possess simple supporting elements or repetitive edges, we present the first global approximation method for principal patches, and we show an extension to volumetric structures for truly threedimensional designs. © 2011 ACM.

  6. Recollision with circular polarization

    Science.gov (United States)

    Mauger, Francois; Kamor, Adam; Bandrauk, Andre; Chandre, Cristel; Uzer, Turgay

    2013-05-01

    Since its identification in the 90s, the recollision scenario has revealed to be very helpful in explaining many phenomena in atomic and molecular systems subjected to strong and short laser pulses, and it is now at the core of the strong field physics and attosecond science. For linearly polarized laser fields, the recollision scenario has been able to explain nonsequential double ionization (NSDI), high harmonic generation (HHG) and laser induced diffraction (LIED), just to cite them. The same scenario also predicts the absence of recollision when the field is circularly polarized, therefore leading to the absence of NSDI, HHG or LIED. Recently, the influence of the ellipticity of the laser has drawn an increasing level of interest in the strong field community as it is seen as a way to control the electronic dynamics and, for instance, HHG. Using classical models, the common belief of the absence of recollision with circularly polarized laser fields has been proven wrong. In my talk I will present classical and quantum evidence of the presence of recollision with circular polarization. I will discuss the conditions under which such recollisions happen and what they imply.

  7. Aharonov-Bohm effect induced by circularly polarized light

    Science.gov (United States)

    Sigurdsson, H.; Kibis, O. V.; Shelykh, I. A.

    2015-11-01

    We demonstrated theoretically that the strong electron interaction with circularly polarized photons in ring-like nanostructures changes the phase of electron wave. This optically-induced effect is caused by the breaking of time-reversal symmetry and is similar to the Aharonov-Bohm effect. As a consequence of this phenomenon, the conductance of mesoscopic rings irradiated by a circularly polarized electromagnetic wave behaves as an oscillating function of the intensity and frequency of the wave.

  8. Underwater Shock Response of Circular HSLA Steel Plates

    OpenAIRE

    Rajendran, R; Narasimhan, K.

    2000-01-01

    Studies on shock response of circular plates subjected to underwater explosion is of interest to ship designers. Non-contact underwater explosion experiments were carried out on air backed circular High Strength Low Alloy (HSLA) steel plates of 4 mm thickness and 290 mm diameter. The experiments were carried out in two phases. In the first phase, strain gauges were fixed at intervals of 30 mm from the centre of the plate and strains were recorded for the shock intensity gradually increasing t...

  9. Circularly polarized antennas

    CERN Document Server

    Gao, Steven; Zhu, Fuguo

    2013-01-01

    This book presents a comprehensive insight into the design techniques for different types of CP antenna elements and arrays In this book, the authors address a broad range of topics on circularly polarized (CP) antennas. Firstly, it introduces to the reader basic principles, design techniques and characteristics of various types of CP antennas, such as CP patch antennas, CP helix antennas, quadrifilar helix antennas (QHA), printed quadrifilar helix antennas (PQHA), spiral antenna, CP slot antennas, CP dielectric resonator antennas, loop antennas, crossed dipoles, monopoles and CP horns. Adva

  10. Antennas on circular cylinders

    DEFF Research Database (Denmark)

    Knudsen, H. L.

    1959-01-01

    antenna in a circular cylinder. By a procedure similar to the one used by Silver and Saunders, expressions have been derived for the field radiated from an arbitrary surface current distribution on a cylinder surface coaxial with a perfectly conducting cylinder. The cases where the space between the two...... cylindrical surfaces have the sane characteristic constants and different constants are treated separately. Extensive numerical computations of the field radiated from the slot antennas described here are being carried out, but no numerical results are yet available...

  11. Differential impact of acute high-intensity exercise on circulating endothelial microparticles and insulin resistance between overweight/obese males and females.

    Directory of Open Access Journals (Sweden)

    Cody Durrer

    Full Text Available An acute bout of exercise can improve endothelial function and insulin sensitivity when measured on the day following exercise. Our aim was to compare acute high-intensity continuous exercise (HICE to high-intensity interval exercise (HIIE on circulating endothelial microparticles (EMPs and insulin sensitivity in overweight/obese men and women.Inactive males (BMI = 30 ± 3, 25 ± 6 yr, n = 6 and females (BMI = 28 ± 2, 21 ± 3 yr, n = 7 participated in three experimental trials in a randomized counterbalanced crossover design: 1 No exercise control (Control; 2 HICE (20 min cycling @ just above ventilatory threshold; 3 HIIE (10 X 1-min @ ∼ 90% peak aerobic power. Exercise conditions were matched for external work and diet was controlled post-exercise. Fasting blood samples were obtained ∼ 18 hr after each condition. CD62E(+ and CD31(+/CD42b- EMPs were assessed by flow cytometry and insulin resistance (IR was estimated by homeostasis model assessment (HOMA-IR.There was a significant sex X exercise interaction for CD62E(+ EMPs, CD31(+/CD42b- EMPs, and HOMA-IR (all P < 0.05. In males, both HICE and HIIE reduced EMPs compared to Control (P ≤ 0.05. In females, HICE increased CD62E(+ EMPs (P < 0.05 vs. Control whereas CD31(+/CD42b- EMPs were unaltered by either exercise type. There was a significant increase in HOMA-IR in males but a decrease in females following HIIE compared to Control (P<0.05.Overweight/obese males and females appear to respond differently to acute bouts of high-intensity exercise. A single session of HICE and HIIE reduced circulating EMPs measured on the morning following exercise in males but in females CD62E(+ EMPs were increased following HICE. Next day HOMA-IR paradoxically increased in males but was reduced in females following HIIE. Future research is needed to investigate mechanisms responsible for potential differential responses between males and females.

  12. Differential effect of soy isoflavones in enhancing high intensity radiotherapy and protecting lung tissue in a pre-clinical model of lung carcinoma

    International Nuclear Information System (INIS)

    Background: Radiotherapy of locally-advanced non-small cell lung cancer is limited by radiation-induced pneumonitis and fibrosis. We have further investigated the role of soy isoflavones to improve the effect of a high intensity radiation and reduce lung damage in a pre-clinical lung tumor model. Methods: Human A549 NSCLC cells were injected i.v. in nude mice to generate a large tumor burden in the lungs. Mice were treated with lung irradiation at 10 Gy and with oral soy. The therapy effect on the tumor cells and surrounding lung tissue was analyzed on lung sections stained with H and E, Ki-67 and Masson’s Trichrome. Pneumonitis and vascular damage were evaluated by measurements of alveolar septa and immunofluorescent staining of vessel walls. Results: Combined soy and radiation caused a significantly stronger inhibition of tumor progression compared to each modality alone in contrast to large invasive tumor nodules seen in control mice. At the same time, soy reduced radiation injury in lung tissue by decreasing pneumonitis, fibrosis and protecting alveolar septa, bronchioles and vessels. Conclusions: These studies demonstrate a differential effect of soy isoflavones on augmenting tumor destruction induced by radiation while radioprotecting the normal lung tissue and support using soy to alleviate radiotoxicity in lung cancer

  13. Double ionization of H2 by intense attosecond laser pulses

    Science.gov (United States)

    Lee, Teck-Ghee; Pindzola, M. S.; Robicheaux, F.

    2010-08-01

    We present calculations of the double ionization of H2 induced by an intense attosecond laser pulse at a photon energy of 40 eV using the time-dependent close-coupling method within the fixed nuclei approximation. We focus on two-photon absorption processes and examine how the response of the ejected electrons, in particular the single- and the double-energy differential probabilities, is affected by linear and circular polarizations at laser-field intensities ranging from 10^{15}\\; \\rm W\\,cm^{-2} to 10^{16}\\; \\rm W\\,cm^{-2} . In general, we find that for both linearly and circularly polarized pulses, sequential peaks and non-sequential wells that appear in both the single- and double-energy differential probabilities are akin to the analogous two-electron photoemission processes in the helium atom driven by intense attosecond pulses. In addition, for the case of a linearly polarized pulse, a clear signature of the sequential double-electron above the threshold ionization process can be seen in these spectra.

  14. Double ionization of H2 by intense attosecond laser pulses

    International Nuclear Information System (INIS)

    We present calculations of the double ionization of H2 induced by an intense attosecond laser pulse at a photon energy of 40 eV using the time-dependent close-coupling method within the fixed nuclei approximation. We focus on two-photon absorption processes and examine how the response of the ejected electrons, in particular the single- and the double-energy differential probabilities, is affected by linear and circular polarizations at laser-field intensities ranging from 1015 W cm-2 to 1016 W cm-2. In general, we find that for both linearly and circularly polarized pulses, sequential peaks and non-sequential wells that appear in both the single- and double-energy differential probabilities are akin to the analogous two-electron photoemission processes in the helium atom driven by intense attosecond pulses. In addition, for the case of a linearly polarized pulse, a clear signature of the sequential double-electron above the threshold ionization process can be seen in these spectra.

  15. Pi, Archimedes and circular splines

    OpenAIRE

    Sablonnière, Paul

    2013-01-01

    In the present paper, we give approximate values of $\\pi$ deduced from the areas of inscribed and circumscribed quadratic and cubic circular splines. Similar results on circular splines of higher degrees and higher approximation orders can be obtained in the same way. We compare these values to those obtained by computing the {\\em perimeters} of those circular splines. We observe that the former are much easier to compute than the latter and give results of the same order. It also appears tha...

  16. Circular PVDF Airborne Transducer

    Institute of Scientific and Technical Information of China (English)

    JIAO Li-hua; XU Li-mei; HONG Hu

    2007-01-01

    With the required increased audio pressure of the parametric ultrasonic transducer array and the difficulty to theoretically analyse the complex ultrasonic structure in audio beam application, an computafionally efficient model is desired to describe the characteristic of the parametric ultrasonic transducer array for the system design and optimization. By applying the symmetry boundary conditions at the mid-plane in the thickness direction, a finite element model based on the half thickness simplification is presented to analyze the parametric circular transducer which is designed by gluing the poly Vinylidene fluoride film (PVDF). The validity of the proposed model is confirmed by a comparison of finite element aalysis results with the theoretical value and experimental data, which show that they are making a good agreement with each other.

  17. Operational circular No. 1 (Rev. 1) – Operational circulars

    CERN Multimedia

    HR Department

    2011-01-01

    Operational Circular No. 1 (Rev. 1) is applicable to members of the personnel and other persons concerned. Operational Circular No. 1 (Rev. 1) entitled "Operational circulars", approved following discussion at the Standing Concertation Committee meeting on 4 May 2011, is available on the intranet site of the Human Resources Department: https://hr-docs.web.cern.ch/hr-docs/opcirc/opcirc.asp It cancels and replaces Operational Circular No. 1 entitled "Operational Circulars” of December 1996. This new version clarifies, in particular, that operational circulars do not necessarily arise from the Staff Rules and Regulations, and the functional titles have been updated to bring them into line with the current CERN organigram. Department Head Office  

  18. Computational simulations of hydrogen circular migration in protonated acetylene induced by circularly polarized light.

    Science.gov (United States)

    Shi, Xuetao; Li, Wen; Schlegel, H Bernhard

    2016-08-28

    The hydrogens in protonated acetylene are very mobile and can easily migrate around the C2 core by moving between classical and non-classical structures of the cation. The lowest energy structure is the T-shaped, non-classical cation with a hydrogen bridging the two carbons. Conversion to the classical H2CCH(+) ion requires only 4 kcal/mol. The effect of circularly polarized light on the migration of hydrogens in oriented C2H3 (+) has been simulated by Born-Oppenheimer molecular dynamics. Classical trajectory calculations were carried out with the M062X/6-311+G(3df,2pd) level of theory using linearly and circularly polarized 32 cycle 7 μm cosine squared pulses with peak intensity of 5.6 × 10(13) W/cm(2) and 3.15 × 10(13) W/cm(2), respectively. These linearly and circularly polarized pulses transfer similar amounts of energy and total angular momentum to C2H3 (+). The average angular momentum vectors of the three hydrogens show opposite directions of rotation for right and left circularly polarized light, but no directional preference for linearly polarized light. This difference results in an appreciable amount of angular displacement of the three hydrogens relative to the C2 core for circularly polarized light, but only an insignificant amount for linearly polarized light. Over the course of the simulation with circularly polarized light, this corresponds to a propeller-like motion of the three hydrogens around the C2 core of protonated acetylene. PMID:27586924

  19. Implementing circularity using partial evaluation

    DEFF Research Database (Denmark)

    Lawall, Julia Laetitia

    2001-01-01

    Complex data dependencies can often be expressed concisely by defining a variable in terms of part of its own value. Such a circular reference can be naturally expressed in a lazy functional language or in an attribute grammar. In this paper, we consider circular references in the context of an...

  20. Circular chemiresistors for microchemical sensors

    Science.gov (United States)

    Ho, Clifford K.

    2007-03-13

    A circular chemiresistor for use in microchemical sensors. A pair of electrodes is fabricated on an electrically insulating substrate. The pattern of electrodes is arranged in a circle-filling geometry, such as a concentric, dual-track spiral design, or a circular interdigitated design. A drop of a chemically sensitive polymer (i.e., chemiresistive ink) is deposited on the insulating substrate on the electrodes, which spreads out into a thin, circular disk contacting the pair of electrodes. This circularly-shaped electrode geometry maximizes the contact area between the pair of electrodes and the polymer deposit, which provides a lower and more stable baseline resistance than with linear-trace designs. The circularly-shaped electrode pattern also serves to minimize batch-to-batch variations in the baseline resistance due to non-uniform distributions of conductive particles in the chemiresistive polymer film.

  1. Autler-Townes effects in attosecond circular polarization molecular photoionization

    International Nuclear Information System (INIS)

    We present molecular photoionization simulations by intense (I ∼ 1016 W/cm2) few cycle circularly polarized attosecond extreme ultraviolet laser pulses for aligned H2+ from numerical solutions of the corresponding time-dependent Schrodinger equation. With appropriate laser pulse parameters, circular attosecond coherent electron wave packets (CEWPs) are created in excited Rydberg states. Such CEWPs are spatially localized during ionization processes, thus resulting in sufficient population oscillations between the resonant excited Rydberg states and the initial ground state. Consequently Autler-Townes splitting in circular polarization energy spectra is predicted, which is shown to be critically sensitive to the pulse intensity, duration, and polarization. The resulting photoelectron angular distributions are rotated with respect to the molecular axis due to the nonspherical Coulomb potential of the molecule, resulting in different ionization rates at different laser polarization-molecular angles.

  2. Future Circular Colliders

    CERN Document Server

    AUTHOR|(CDS)2108454; Zimmermann, Frank

    2015-01-01

    In response to a request from the 2013 Update of the European Strategy for Particle Physics, the global Future Circular Collider (FCC) study is preparing the foundation for a next-generation large-scale accelerator infrastructure in the heart of Europe. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh), to be accommodated in a new ∼100 km tunnel near Geneva. It also includes the design of a high-luminosity electron-positron collider (FCC-ee), which could be installed in the same tunnel as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detectors, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on Nb3Sn superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton collider. The interna...

  3. Future Circular Colliders

    CERN Document Server

    AUTHOR|(CDS)2108454; Zimmermann, Frank

    2015-01-01

    In response to a request from the 2013 Update of the European Strategy for Particle Physics, the global Future Circular Collider (FCC) study is preparing the foundation for a next-generation large-scale accelerator infrastructure in the heart of Europe. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh), to be accommodated in a new ∼100 km tunnel near Geneva. It also includes the design of a high-luminosity electron-positron collider (FCC-ee), which could be installed in the same tunnel as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detector, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on Nb3Sn superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton collider. The internat...

  4. Towards Future Circular Colliders

    CERN Document Server

    AUTHOR|(CDS)2108454; Zimmermann, Frank

    2015-01-01

    The Large Hadron Collider (LHC) at CERN presently provides proton-proton collisions at a centre-of-mass (c.m.) energy of 13 TeV. The LHC design was started more than 30 years ago, and its physics programme will extend through the second half of the 2030’s. The global Future Circular Collider (FCC) study is now preparing for a post-LHC project. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh) in a new ∼100 km tunnel. It also includes the design of a high-luminosity electron-positron collider (FCC-ee) as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detectors, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on $Nb_3Sn$ superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton c...

  5. Discussion of Differentiation and Treatment of Traditional Chinese Medicine on Intensive Hand-foot-mouth Disease%手足口病重症辨证论治探讨

    Institute of Scientific and Technical Information of China (English)

    陈争光; 汪受传

    2011-01-01

    The paper summarizes and evaluates research about the intensive hand-foot-mouth disease,which was studied by Chinese medicine experts in recent years. The advice about the differentiation and treatment of traditional Chinese medicine on the intensive hand-foot-mouth disease is brought up by investigating expert questionnaires.%综述近年来中医专家对手足口病重症的研究报道并加以评价,通过专家调查问卷的方式,提出手足口病重症的中医辨证分型及据证施方的意见.

  6. Circularly-Polarized Microstrip Antenna

    Science.gov (United States)

    Stanton, P. H.

    1985-01-01

    Microstrip construction compact for mobile applications. Circularly polarized microstrip antenna made of concentric cylindrical layers of conductive and dielectric materials. Coaxial cable feedlines connected to horizontal and vertical subelements from inside. Vertical subelement acts as ground for horizontal subelement.

  7. Coloring fuzzy circular interval graphs

    OpenAIRE

    Eisenbrand, Friedrich; Niemeier, Martin

    2012-01-01

    Computing the weighted coloring number of graphs is a classical topic in combinatorics and graph theory. Recently these problems have again attracted a lot of attention for the class of quasi-line graphs and more specifically fuzzy circular interval graphs. The problem is NP-complete for quasi-line graphs. For the subclass of fuzzy circular interval graphs however, one can compute the weighted coloring number in polynomial time using recent results of Chudnovsky and Ovetsky and of King and Re...

  8. Energy dissipation in circular tube

    OpenAIRE

    A.D. Girgidov

    2012-01-01

    Energy dissipation distribution along the circular tube radius is important in solving such problems as calculation of heat transfer by the air flow through building envelope; calculation of pressure loss in spiral flows; calculation of cyclones with axial and tangential supply of dust-containing gas.Two types of one-dimensional radially axisymmetric flows in circular tube were considered: axial flow and rotation about the axis (Rankine vortex). Relying on two- and four-layer description of a...

  9. Elastostatic bending of a bimaterial plate with a circular interface

    Science.gov (United States)

    Ogbonna, Nkem

    2015-08-01

    The elastostatic bending of an arbitrarily loaded bimaterial plate with a circular interface is analysed. It is shown that the deflections in the composite solid are directly related to the deflection in the corresponding homogeneous material by integral and differential operators. It is further shown that, by a simple transformation of elastic constants, the Airy stress function induced in the composite by a stretching singularity can be deduced from the deflection induced by a bending singularity. This result is significant for reduction of mathematical labour and for systematic construction of solutions for more complex structures with circular geometry.

  10. Axisymmetrical bending of circular plates with eccentric stiffeners

    International Nuclear Information System (INIS)

    Small deflection bending theory of stiffened circular plates with uniformly spaced radial and circunferential ribs is presented. Equilibrium differential equations for the axisymmetric case, in terms of the displacements u and w of the middle surface of the plate are derived, and their general solutions are found. Closed form solutions for the circular plate with uniformly distributed bending moments along its edge are given for the special case in which geometrical and elastic properties of the ribs are constant and equal along both radial and circunferential directions. (Author)

  11. Modeling and Simulation of Nonlinear Micro-electromechanical Circular Plate

    Directory of Open Access Journals (Sweden)

    Chin-Chia Liu

    2013-09-01

    Full Text Available In the present study, the hybrid differential transformation and finite difference method is applied to analyze the dynamic behavior of the nonlinear micro-electromechanical circular plate actuated by combined DC / AC loading schemes. The analysis takes account of the axial residual stress and hydrostatic pressure acting on micro circular plate upper surface. The dynamic response of the plate as a function of the magnitude of the AC driving voltage is explored. Moreover, the effect of the initial gap height on the pull-in voltage of the plate is systematically explored.

  12. Beam diagnostics in circular machines: Review of new developments

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, G.

    1990-06-01

    Recent developments in beam diagnostic equipment and measurement techniques have been driven by commercial technological advances, better data analysis algorithms, and the need to measure complex beam properties. The need for such developments is due to the increased diversity, beam intensity, and luminosity/brightness requirements of charged particle circular accelerators. In addition, the advent of fast analog-to-digital converters and cheap, powerful microprocessors have fundamentally changed the approach to beam diagnosis, allowing designers to create systems where signal processing is performed locally at each detector. New beam monitors from a wide variety of circular accelerators are reviewed. A number of interesting or innovative ideas are presented in detail. 56 refs.

  13. THE PROBLEM OF AN EXTERNAL CIRCULAR CRACK UNDER ASYMMETRIC LOADINGS

    Institute of Scientific and Technical Information of China (English)

    王银邦

    2001-01-01

    Using the boundary integral equation method, the problem of an external circular crack in a three-dimensional infinite elastic body under asymmetric loadings is investigated. The two- dimensional singular boundary integral equations of the problem were reduced to a system of Abel integral equations by means of Fourier series and hypergeometric functions. The exact solutions of stress intensity factors are obtained for the problem of an external circular crack under asymmetric loadings, which are even more universal than the results obtained by the use of Hankel transform method. The results demonstrate that the boundary integral equation method has great potential as a new analytic method.

  14. Large Enhancement of Circular Dichroism Using an Embossed Chiral Metamaterial

    CERN Document Server

    Mousavi, S Hamed Shams; El-Sayed, Mostafa A; Eftekhar, Ali A; Adibi, Ali

    2016-01-01

    In the close vicinity of a chiral nanostructure, the circular dichroism of a biomolecule could be greatly enhanced, due to the interaction with the local superchiral fields. Modest enhancement of optical activity using a planar metamaterial, with some chiral properties, and achiral nanoparticles has been previously reported. A more substantial chirality enhancement can be achieved in the local filed of a chiral nanostructure with a three-dimensional arrangement. Using an embossed chiral nanostructure designed for chiroptical sensing, we measure the circular dichroism spectra of two biomolecules, Chlorophylls A and B, at the molecular level, using a simple polarization resolved reflection measurement. This experiment is the first realization of the on-resonance surface-enhanced circular dichroism, achieved by matching the chiral resonances of a strongly chiral metamaterial with that of a chiral molecule, resulting in an unprecedentedly large differential CD spectrum from a monolayer of a chiral material.

  15. Circularly polarized open-loop antenna

    OpenAIRE

    Li, Rong-Lin; Fusco, Vincent F.; Nakano, Hisamatsu

    2003-01-01

    A printed circular open-loop antenna is introduced as a simple structure for producing circular polarization; the antenna is fed with a coaxial probe. By introducing a gap within the circular loop a traveling-wave current is excited and thus circularly polarized radiation can be achieved. An optimized circularly polarized antenna is designed through numerical analysis using a so-called parametric method of moment technique. Experimental verification of the new antenna is presented. The antenn...

  16. Claw-free circular-perfect graphs

    OpenAIRE

    Pecher, Arnaud; Zhu, Xuding

    2007-01-01

    The circular chromatic number of a graph is a well studied refinement of the chromatic number. Circular perfect graphs is a superclass of perfect graphs defined by means of this more general coloring concept. This paper studies claw free circular perfect graphs. A consequence of the strong perfect graph theorem is that minimal circular perfect graphs G. In contrast to this result, it is shown in that minimal circular imperfect graphs G can have arbitrarily large independence number and arbitr...

  17. Podokinetic circular vection: characteristics and interaction with optokinetic circular vection.

    Science.gov (United States)

    Becker, W; Kliegl, K; Kassubek, J; Jürgens, R

    2016-07-01

    Stabilising horizontal body orientation in space without sight on a rotating platform by holding to a stationary structure and circular 'treadmill' stepping in the opposite direction can elicit an illusion of self-turning in space (Bles and Kapteyn in Agressologie 18:325-328, 1977). Because this illusion is analogous to the well-known illusion of optokinetic circular vection (oCV), we call it 'podokinetic circular vection' (pCV) here. Previous studies using eccentric stepping on a path tangential to the rotation found that pCV was always contraversive relative to platform rotation. In contrast, when our subjects stepped at the centre of rotation about their vertical axis, we observed an inverted, ipsiversive pCV as a reproducible trait in many of our subjects. This ipCV occurred at the same latency as the pCV of subjects reporting the actually expected contraversive direction, but had lower gain. In contrast to pCV, the nystagmus accompanying circular treadmill stepping had the same direction in all individuals (slow phase in the direction of platform motion). The direction of an individual's pCV predicted the characteristics of the CV resulting from combined opto- and podokinetic stimulation (circular treadmill stepping while viewing a pattern rotating together with the platform): in individuals with contraversive pCV, latency shortened and both gain and felt naturalness increased in comparison with pure oCV, whereas the opposite (longer latency, reduced gain and naturalness) occurred in individuals with ipCV. Taken together, the reproducibility of ipCV, the constant direction of nystagmus and the fact that pCV direction predicts the outcome of combined stimulation suggest that ipCV is an individual trait of many subjects during compensatory stepping at the centre of rotation. A hypothetical model is presented of how ipCV possibly could arise. PMID:26965438

  18. Differential effects of low-intensity motor cortical stimulation on the inspiratory activity in scalene muscles during voluntary and involuntary breathing

    DEFF Research Database (Denmark)

    Petersen, Nicolas Caesar; Taylor, Janet L; Murray, Nicholas P S; Gandevia, Simon C; Butler, Jane E

    2011-01-01

    To assess the cortical contribution to breathing, low-intensity transcranial magnetic stimulation (TMS) was delivered over the motor cortex in 10 subjects during: (i) voluntary static inspiratory efforts, (ii) hypocapnic voluntary ventilation (end-tidal CO(2), 2.7±0.4% mean±SD), and (iii) hyperca...

  19. Circular RNA expands its territory.

    Science.gov (United States)

    Bao, Chunyang; Lyu, Dongbin; Huang, Shenglin

    2016-03-01

    Circular RNAs (circRNAs) represent a novel class of widespread non-coding RNAs in eukaryotes. They are unusually stable RNA molecules with cell type-specific expression patterns, and are predominantly present in the cytoplasm. We recently demonstrated the existence of abundant circRNAs in exosomes and suggest a potential application of exosomal circRNAs for cancer detection. PMID:27308606

  20. Circular polarization observed in bioluminescence

    NARCIS (Netherlands)

    Wijnberg, Hans; Meijer, E.W.; Hummelen, J.C.; Dekkers, H.P.J.M.; Schippers, P.H.; Carlson, A.D.

    1980-01-01

    While investigating circular polarization in luminescence, and having found it in chemiluminescence, we have studied bioluminescence because it is such a widespread and dramatic natural phenomenon. We report here that left and right lanterns of live larvae of the fireflies, Photuris lucicrescens and

  1. Application of circular filter inserts

    International Nuclear Information System (INIS)

    High efficiency particulate air (HEPA) filters are used in the ventilation of nuclear plant as passive clean-up devices. Traditionally, the work-horse of the industry has been the rectangular HEPA filter. An assessment of the problems associated with remote handling, changing, and disposal of these rectangular filters suggested that significant advantages to filtration systems could be obtained by the adoption of HEPA filters with circular geometry for both new and existing ventilation plants. This paper covers the development of circular geometry filters and highlights the advantages of this design over their rectangular counterparts. The work has resulted in a range of commercially available filters for flows from 45 m3/h up to 3400 m3/h. This paper also covers the development of a range of sizes and types of housings that employ simple change techniques which take advantage of the circular geometry. The systems considered here have been designed in response to the requirements for shielded (remote filter change) and for unshielded facilities (potentially for bag changing of filters). Additionally the designs have allowed for the possibility of retrofitting circular geometry HEPA filters in place of the rectangular geometry filter

  2. Mammography. Advanced, intensive course and atlas. Senology, screening, radiographic morphology, differential diagnosis, unusual findings, false treatment as a case in court

    International Nuclear Information System (INIS)

    Differential diagnosis is the focal point of this richly illustrated atlas intended for experienced mammographers. Mammographs of different histology but with similar features are presented side by side for easy comparison; pinpointed questions accompanying the pictures are guiding the reader to systematically develop the differential dioagnosis, with correct answers being given on the next pages together with characteristic and typical pictures explaining the correct and false diagnoses, including clinical photographs and sonographic images. Unusual mammographic findings are discussed in a separate chapter, and other chapters deal with the history of senology and with problems encountered in examinations for early diagnosis, as reported in the German Mammography Study and in international screening projects. The concluding chapter deals with legal aspects such as liability of the physician in case of missed detection of tumors, explaining the most frequent causes of false diagnosis as a guide to preventing errors, and giving practical hints and information for the event of damages being claimed from a physician. (orig.)

  3. Electron scattering from Xe: the relation between the differential elastic cross section and shape and intensity of the energy loss spectra

    Energy Technology Data Exchange (ETDEWEB)

    Vos, Maarten, E-mail: maarten.vos@anu.edu.a [Atomic and Molecular Physics Laboratories, Research School of Physics and Engineering, Australian National University, Canberra, ACT (Australia)

    2010-11-14

    The measurement of the energy loss spectra of energetic electrons scattered from Xe over large angles is reported. The incoming energy was chosen between 600 eV and 1550 eV. The calculated Xe elastic scattering cross section has a sharp minimum for 750 eV electrons near 135{sup 0}. This minimum is confirmed by studying a Xe-H{sub 2} mixture and separating their elastic peak based on the recoil effect. The energy loss part of the Xe spectra is rich in structure. Surprisingly the shape and intensity (relative to the elastic peak) changes dramatically if one approaches the scattering conditions for which the elastic cross section has a minimum. These observations are rationalized by describing the inelastic intensity semi-classically, as a consequence of a two-step process occurring at the same atom involving scattering from the nucleus and an electronic excitation. The change in shape of the loss spectra is attributed to a large increase in relative intensity of the dipole-forbidden transitions near sharp minima in the elastic cross section.

  4. Double ionization of H{sub 2} by intense attosecond laser pulses

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Teck-Ghee; Pindzola, M S; Robicheaux, F, E-mail: tg10002@auburn.ed [Department of Physics, Auburn University, Auburn, AL 36849 (United States)

    2010-08-28

    We present calculations of the double ionization of H{sub 2} induced by an intense attosecond laser pulse at a photon energy of 40 eV using the time-dependent close-coupling method within the fixed nuclei approximation. We focus on two-photon absorption processes and examine how the response of the ejected electrons, in particular the single- and the double-energy differential probabilities, is affected by linear and circular polarizations at laser-field intensities ranging from 10{sup 15} W cm{sup -2} to 10{sup 16} W cm{sup -2}. In general, we find that for both linearly and circularly polarized pulses, sequential peaks and non-sequential wells that appear in both the single- and double-energy differential probabilities are akin to the analogous two-electron photoemission processes in the helium atom driven by intense attosecond pulses. In addition, for the case of a linearly polarized pulse, a clear signature of the sequential double-electron above the threshold ionization process can be seen in these spectra.

  5. Simulation of erasure of photoinduced anisotropy by circularly polarized light

    DEFF Research Database (Denmark)

    Sajti, Sz.; Kerekes, Á.; Barabás, M.; Lorincz, E; Hvilsted, Søren; Ramanujam, P.S.

    The temporal evolution of photoinduced birefringence is investigated on the basis of a model proposed by Pedersen and co-workers, This model is extended for the case of elliptically polarized light, and used to describe the erasure of photoinduced birefringence by circularly polarized light. It i...... shown that the anisotropy is not erased, only the direction of the optical axis is changed, and this is measured as erasure. The computed results are compared with measurements and show good agreement for several intensities....

  6. Convex mappings on some circular domains

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this paper,we consider some circular domains.And we give an extension theorem for some normalized biholomorphic convex mapping on some circular domains.Especially,we discover the normalized biholomorphic convex mapping on some circular domains have the form f(z) =(f1(z1),...,fn(zn)),where fj:D → C are normalized biholomorphic convex mapping.

  7. Modelling the impacts of a carbon emission-differentiated vehicle tax system on CO2 emissions intensity from new vehicle purchases in Ireland

    International Nuclear Information System (INIS)

    The increasing awareness of the effects of climate change on the environment and the economic pressure on oil supply has focused international attention on reducing CO2 emissions and energy usage across all sectors. In order to meet their Kyoto protocol commitments and in line with European Union policy, the Irish government has introduced a carbon-based tax system for new vehicles purchased from the 1st of July 2008. This new legislation aims to reduce carbon emissions in the transport sector, a sector which is responsible for a significant proportion of both. This paper presents the results of the development, calibration, and application of a car choice model which predicts the changes in CO2 emissions intensity from new vehicle purchases as a result of the changes in vehicle tax policy and fuel price in Ireland. The model also predicts the impact of such changes on tax revenue for the Irish government and the changes in the split between the number of diesel and petrol vehicles purchased. The investigation found that the introduction of these new carbon-based taxes in Ireland will result in a reduction of 3.6-3.8% in CO2 emissions intensity and a reduction in annual tax revenue of EUR191 M. (author)

  8. Modelling the impacts of a carbon emission-differentiated vehicle tax system on CO2 emissions intensity from new vehicle purchases in Ireland

    International Nuclear Information System (INIS)

    The increasing awareness of the effects of climate change on the environment and the economic pressure on oil supply has focused international attention on reducing CO2 emissions and energy usage across all sectors. In order to meet their Kyoto protocol commitments and in line with European Union policy, the Irish government has introduced a carbon-based tax system for new vehicles purchased from the 1st of July 2008. This new legislation aims to reduce carbon emissions in the transport sector, a sector which is responsible for a significant proportion of both. This paper presents the results of the development, calibration, and application of a car choice model which predicts the changes in CO2 emissions intensity from new vehicle purchases as a result of the changes in vehicle tax policy and fuel price in Ireland. The model also predicts the impact of such changes on tax revenue for the Irish government and the changes in the split between the number of diesel and petrol vehicles purchased. The investigation found that the introduction of these new carbon-based taxes in Ireland will result in a reduction of 3.6-3.8% in CO2 emissions intensity and a reduction in annual tax revenue of Euro 191 M

  9. Quantitative assessment of the use of modified nucleoside triphosphates in expression profiling: differential effects on signal intensities and impacts on expression ratios

    Directory of Open Access Journals (Sweden)

    Dorris David

    2002-07-01

    Full Text Available Abstract Background The power of DNA microarrays derives from their ability to monitor the expression levels of many genes in parallel. One of the limitations of such powerful analytical tools is the inability to detect certain transcripts in the target sample because of artifacts caused by background noise or poor hybridization kinetics. The use of base-modified analogs of nucleoside triphosphates has been shown to increase complementary duplex stability in other applications, and here we attempted to enhance microarray hybridization signal across a wide range of sequences and expression levels by incorporating these nucleotides into labeled cRNA targets. Results RNA samples containing 2-aminoadenosine showed increases in signal intensity for a majority of the sequences. These results were similar, and additive, to those seen with an increase in the hybridization time. In contrast, 5-methyluridine and 5-methylcytidine decreased signal intensities. Hybridization specificity, as assessed by mismatch controls, was dependent on both target sequence and extent of substitution with the modified nucleotide. Concurrent incorporation of modified and unmodified ATP in a 1:1 ratio resulted in significantly greater numbers of above-threshold ratio calls across tissues, while preserving ratio integrity and reproducibility. Conclusions Incorporation of 2-aminoadenosine triphosphate into cRNA targets is a promising method for increasing signal detection in microarrays. Furthermore, this approach can be optimized to minimize impact on yield of amplified material and to increase the number of expression changes that can be detected.

  10. Energy dissipation in circular tube

    Directory of Open Access Journals (Sweden)

    A.D. Girgidov

    2012-01-01

    Full Text Available Energy dissipation distribution along the circular tube radius is important in solving such problems as calculation of heat transfer by the air flow through building envelope; calculation of pressure loss in spiral flows; calculation of cyclones with axial and tangential supply of dust-containing gas.Two types of one-dimensional radially axisymmetric flows in circular tube were considered: axial flow and rotation about the axis (Rankine vortex. Relying on two- and four-layer description of axial turbulent flow energy dissipation was calculated in each layer.Similar calculation for Rankine vortex with viscous sublayer at the tube surface was provided. By employing the dissipation minimum principle the boundary radius between rigid rotation and free vortex is calculated. Approximation of the velocity distribution in Rankine vortex is proposed.

  11. Capacitance of circular patch resonator

    International Nuclear Information System (INIS)

    In this paper the capacitance of the circular microstrip patch resonator is computed. It is shown that the electrostatic problem can be formulated as a system of dual integral equations, and the most interesting techniques of solutions of these systems are reviewed. Some useful approximated formulas for the capacitance are derived and plots of the capacitance are finally given in a wide range of dielectric constants

  12. Capacitance of circular patch resonator

    Energy Technology Data Exchange (ETDEWEB)

    Miano, G.; Verolino, L. [Dip. di Ingegneria Elettrica, Ist. Nazionale di Fisica Nucleare, Naples (Italy); Panariello, G. [Dip. di Ingegneria Elettronica, Naples (Italy); Vaccaro, V.G. [Ist. Nazionale di Fisica Nucleare, Naples (Italy). Dipt. di Scienze Fisiche

    1995-11-01

    In this paper the capacitance of the circular microstrip patch resonator is computed. It is shown that the electrostatic problem can be formulated as a system of dual integral equations, and the most interesting techniques of solutions of these systems are reviewed. Some useful approximated formulas for the capacitance are derived and plots of the capacitance are finally given in a wide range of dielectric constants.

  13. Longitudinal motion in circular accelerators

    International Nuclear Information System (INIS)

    A general description is given of the longitudinal motion of an idealized synchronous particle, exactly in step with the radiofrequency field of a circular accelerator, and a domain in phase and energy, called a bucket, around this particle within which particles are focused around the synchronous particle. This general picture is then made more precise and quantitative. The equations of longitudinal motion and their solutions and the resulting motion are discussed, followed by applications and amplication of the theory. 7 refs., 8 figs

  14. Design and construction of a mode converter from TE10(rectangular) to TE11(circular)

    International Nuclear Information System (INIS)

    The design and manufacturing of a wavelength mode converter from the TE10 (rectangular) mode in oversized rectangular to the TE11 (circular) mode in oversized circular waveguide is described. A differential equation for the cross-sectional shape of the converter was solved numerically. A stainless-steel mandrel was produced on a numerically controlled milling machine. Sixteen converters were produced by means of electroforming on one mandrel. (Auth.)

  15. Circular Polarization in Pulsar Integrated Profiles: Updates

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    We update the systematic studies of circular polarization in integrated pulse profiles by Han et al. Data of circular polarization profiles are compiled. Sense reversals can occur in core or cone components, or near the intersection between components. The correlation between the sense of circular polarization and the sense of position angle variation for conal-double pulsars is confirmed with a much large database. Circular polarization of some pulsars has clear changes with frequency.Circular polarization of millisecond pulsars is marginally different from that of normal pulsars.

  16. Total positive curvature of circular DNA

    DEFF Research Database (Denmark)

    Bohr, Jakob; Olsen, Kasper Wibeck

    2013-01-01

    micro-DNAs longer than the minimum length must be concave, a result that is consistent with typical atomic force microscopy images of plasmids. Predictions for the total positive curvature of circular micro-DNAs are given as a function of length, and comparisons with circular DNAs from the literature...... molecules, e.g., plasmids, it is shown to have implications for the total positive curvature integral. For small circular micro-DNAs it follows as a consequence of Fenchel's inequality that there must exist a minimum length for the circular plasmids to be double stranded. It also follows that all circular...

  17. Countermeasures for Circular Agricultural Development of Chongqing Based on AHP Approach

    OpenAIRE

    Yang, Taiyan; Bai, Shuo; SUN, Shunqiang

    2014-01-01

    With rapid economic development, resource and environment problems become more and more prominent. Chongqing Municipality, as a city focusing on industrial development in the past, has serious problem of environmental pollution and scarce agricultural resources. At present, it is urgent to find out how to develop circular agriculture and coordinate economic, social, environmental development. On the basis of understanding the intension of circular agriculture, this paper built evaluation indi...

  18. THREE-DIMENSIONAL INTERACTIONS OF CIRCULAR CRACK IN TRANSVERSELY ISOTROPIC PIEZOELECTRIC SPACE WITH RESULTANT SOURCES

    Institute of Scientific and Technical Information of China (English)

    HOU Peng-fei; DING Hao-jiang; Leung Andraw-YT

    2006-01-01

    Exact solutions in form of elementary functions were derived for the stress and electric displacement intensity factors of a circular crack in a transversely isotropic piezoelectric space interacting with various stress and charge sources: force dipoles, electric dipoles, moments, force dilatation and rotation. The circular crack includes penny-shaped crack and external circular crack and the locations and orientations of these resultant sources with respect to the crack are arbitrary. Such stress and charge sources may model defects like vacancies, foreign particles, and dislocations. Numerical results are presented at last.

  19. A computational protocol for the study of circularly polarized phosphorescence and circular dichroism in spin-forbidden absorption.

    Science.gov (United States)

    Kamiński, Maciej; Cukras, Janusz; Pecul, Magdalena; Rizzo, Antonio; Coriani, Sonia

    2015-07-15

    We present a computational methodology to calculate the intensity of circular dichroism (CD) in spin-forbidden absorption and of circularly polarized phosphorescence (CPP) signals, a manifestation of the optical activity of the triplet-singlet transitions in chiral compounds. The protocol is based on the response function formalism and is implemented at the level of time-dependent density functional theory. It has been employed to calculate the spin-forbidden circular dichroism and circularly polarized phosphorescence signals of valence n → π* and n ← π* transitions, respectively, in several chiral enones and diketones. Basis set effects in the length and velocity gauge formulations have been explored, and the accuracy achieved when employing approximate (mean-field and effective nuclear charge) spin-orbit operators has been investigated. CPP is shown to be a sensitive probe of the triplet excited state structure. In many cases the sign of the spin-forbidden CD and CPP signals are opposite. For the β,γ-enones under investigation, where there are two minima on the lowest triplet excited state potential energy surface, each minimum exhibits a CPP signal of a different sign. PMID:26126575

  20. Deterministic Circular Self Test Path

    Institute of Scientific and Technical Information of China (English)

    WEN Ke; HU Yu; LI Xiaowei

    2007-01-01

    Circular self test path (CSTP) is an attractive technique for testing digital integrated circuits(IC) in the nanometer era, because it can easily provide at-speed test with small test data volume and short test application time. However, CSTP cannot reliably attain high fault coverage because of difficulty of testing random-pattern-resistant faults. This paper presents a deterministic CSTP (DCSTP) structure that consists of a DCSTP chain and jumping logic, to attain high fault coverage with low area overhead. Experimental results on ISCAS'89 benchmarks show that 100% fault coverage can be obtained with low area overhead and CPU time, especially for large circuits.

  1. Differential dosimetric benefit of proton beam therapy over intensity modulated radiotherapy for a variety of targets in patients with intracranial germ cell tumors

    International Nuclear Information System (INIS)

    We performed dosimetric comparisons between proton beam therapy and intensity modulated radiotherapy (IMRT) of intracranial germ cell tumors (ICGCTs) arising in various locations of the brain. IMRT, passively scattered proton therapy (PSPT), and spot scanning proton therapy (SSPT) plans were performed for four different target volumes: the whole ventricle (WV), pineal gland (PG), suprasellar (SS), and basal ganglia (BG). Five consecutive clinical cases were selected from the patients treated between 2011 and 2014 for each target volume. Total 20 cases from the 17 patients were included in the analyses with three overlap cases which were used in plan comparison both for the whole ventricle and boost targets. The conformity index, homogeneity index, gradient index, plan quality index (PQI), and doses applied to the normal substructures of the brain were calculated for each treatment plan. The PQI was significantly superior for PSPT and SSPT than IMRT for ICGCTs in all locations (median; WV: 2.89 and 2.37 vs 4.06, PG: 3.38 and 2.70 vs 4.39, SS: 3.92 and 2.49 vs 4.46, BG: 3.01 and 2.49 vs 4.45). PSPT and SSPT significantly reduced the mean dose, and the 10 and 15 Gy dose volumes applied to the normal brain compared with IMRT (p ≤ 0.05). PSPT and SSPT saved significantly greater volumes of the temporal lobes and hippocampi (p < 0.05) in the SS and PG targets than IMRT. For tumors arising in the BG, PSPT and SSPT also saved greater volumes of the contralateral temporal lobes. PSPT and SSPT provide superior target volume coverage and saved more normal tissue compared with IMRT for ICGCTs in various locations. Future studies should assess whether the extent of normal tissue saved has clinical benefits in children with ICGCTs. The online version of this article (doi:10.1186/s13014-015-0441-5) contains supplementary material, which is available to authorized users

  2. Physics at Future Circular Colliders

    Science.gov (United States)

    Kotwal, Ashutosh

    2016-03-01

    The Large Hadron Collider has been a grand success with the discovery of the Higgs boson, with bright prospects for additional discoveries since the recent increase in collider energy and the anticipated large datasets. Big open questions such as the nature of dark matter, the origin of the matter-antimatter asymmetry in the Universe, and the theoretical puzzle of the finely-tuned parameters in the Higgs sector, demand new physics principles that extend the established Standard Model paradigm. Future circular colliders in a substantially larger tunnel can house both a high luminosity electron-positron collider for precision measurements of Higgs and electroweak parameters, as well as a very high energy proton-proton collider which can directly manifest particles associated with these new physics principles. We discuss the physics goals of these future circular colliders, and the prospects for elucidating fundamental new laws of nature that will significantly extend our understanding of the Universe. Detailed studies of the discovery potential in specific benchmark models will be presented, with implications for detector design.

  3. Exact axisymmetric solutions for laminated transversely isotropic piezoelectric circular plate (Ⅰ)——Exact solutions for piezoelectric circular plate

    Institute of Scientific and Technical Information of China (English)

    丁皓江; 徐荣桥; 国凤林

    1999-01-01

    Based on three-dimensional elastic equations for piezoelectric materials, the state equations for piezoelectric circular plate under axisymmetric deformation are derived. Applying Hankel transform to them and letting the free boundary terms resulting from Hankel transform be zero, a set of ordinary differential equations with constant coefficients and associated boundary conditions are obtained. Furthermore, two exact solutions corresponding to generalized rigid slipping and generalized elastic simple support are deduced. Then, the governing equations obtained reduce to equations for axisymmetric problem of transversely isotropic circular plate. Under the two types of boundary conditions of elastic simple support and rigid slipping, exact solutions are derived. Finally, numerical results are presented and applicability of the classical plate theory is discussed.

  4. Mixing in Circular and Non-circular Jets in Crossflow

    DEFF Research Database (Denmark)

    Salewski, Mirko; Stankovic, D.; Fuchs, L.

    2008-01-01

    are compared for circular, elliptic, and square nozzles. For the latter configurations, effects of orientation are considered. The computations reveal that the distribution of a passive scalar in a cross-sectional plane can be single- or double-peaked, depending on the nozzle shape and orientation. A proper...... orthogonal decomposition of the transverse velocity indicates that coherent structures may be responsible for this phenomenon. Nozzles which have a single-peaked distribution have stronger modes in transverse direction. The global mixing performance is superior for these nozzle types. This is the case...... for the blunt square nozzle and for the elliptic nozzle with high aspect ratio. It is further demonstrated that the flow field contains large regions in which a passive scalar is transported up the mean gradient (counter-gradient transport) which implies failure of the gradient diffusion hypothesis....

  5. CIRCULAR ECONOMY IN ROMANIA WITHIN EUROPEAN CONTEXT

    OpenAIRE

    Cornelia Marcela Danu; Valentin Nedeff

    2015-01-01

    In the present paper we have approached some conceptual and coordinated marks of the societal reality connected to the circular economy. Generated by „the limits of certainty” regarding the future of the world business, the operationalization of the circular economy has become a part of the EU strategies and started the various stages of implementation as an active process in all countries. We have highlighted the opportunities and the risks related to the circular economy, the European dimen...

  6. A COMPACT CIRCULARLY POLARIZED SLOTTED MICROSTRIP ANTENNA

    OpenAIRE

    V. Jebaraj; K.R.S. Ravi Kumar; D. Mohanageetha

    2014-01-01

    Slot antennas are often used at UHF and microwave frequencies. In slot antenna for RFID reader applications the frequency ranges from 902-923MHz to achieve circular polarization. The shapes and size of the slot, as well as the driving frequency, determine the radiation distribution pattern. The proposed compact size circularly polarized slotted microstrip antenna are summarized with design rules. The circularly polarized radiation in square patch antenna can be obtained by perturbation techni...

  7. Reconfigurable Monopole Antennas With Circular Polarization

    OpenAIRE

    Panahi, Afshin

    2015-01-01

    This thesis presents research on printed circularly-polarized monopole antennas and their application in reconfigurable monopole antennas. The proposed circularly-polarised monopole antennas benefit from advantages such as small size, low-cost, low-profile and simple designs. The first part of this thesis introduces three printed circularly-polarized monopole antennas for global navigation satellite systems and Wi-Fi applications. The primary focus is on the ground plane which is used as a ra...

  8. A computational protocol for the study of circularly polarized phosphorescence and circular dichroism in spin-forbidden absorption

    DEFF Research Database (Denmark)

    Kaminski, Maciej; Cukras, Janusz; Pecul, Magdalena;

    2015-01-01

    We present a computational methodology to calculate the intensity of circular dichroism (CD) in spinforbidden absorption and of circularly polarized phosphorescence (CPP) signals, a manifestation of the optical activity of the triplet–singlet transitions in chiral compounds. The protocol is based...... chiral enones and diketones. Basis set effects in the length and velocity gauge formulations have been explored, and the accuracy achieved when employing approximate (mean-field and effective nuclear charge) spin–orbit operators has been investigated. CPP is shown to be a sensitive probe of the triplet...... excited state structure. In many cases the sign of the spin-forbidden CD and CPP signals are opposite. For the b,g-enones under investigation, where there are two minima on the lowest triplet excited state potential energy surface, each minimum exhibits a CPP signal of a different sign....

  9. Focal hepatic nodules with high signal intensity on T1-weighted MR imaging : differentiation of small hepatocellular carcinoma from dysplastic nodule by quantitative analysis of multi-phase contrast-enhanced dynamic MR imaging

    International Nuclear Information System (INIS)

    To evaluate the usefulness of quantitative analysis of the degree of enhancement in dynamic MR imaging used to differentiate dysplastic nodule (DN) from small hepatocellular carcinoma (HCC), both of which show high signal intensity on T1-weighted images. From 26 small HCCs and 71 DNs, all of which showed homogeneous high signal intensity on T1-weighted images among 42 patients with liver cirrhosis, we selected 16 small HCCs and 10 DNs of more than 1cm in diameter which were diagnosed by biopsy and follow-up imaging. Dynamic MR imaging of the entire liver was obtained using the breath-hold technique at postinjection 10 sec. (phase 1), 35 sec. (phase 2), 60 sec. (phase 3), and 5 min. (delayed) after intravenous manual injection of Gd-DTPA (0.1 mmol/kg) at a velocity of 3-4 cc/sec. Nodule-to-liver contrast-to-noise ratios (CNR) during each phase were calculated by measurement of the region of interest. On precontrast T1-weighted images, the mean CNR of small HCCs was 2.873, and that of DNs was 3.854, there was thus no significant statistical difference (p>0.01). On postcontrast images, the CNR of small HCCs during each phase was 5.565, 3.790, 1.704, and 1.282, with peak CNR phase 1 and a mostly decreasing trend thereafter. However, the CNR of DNs during each phase was 3.053, 1.561, 0.919, and 1.038 ; there was thus showed no significant increase during phase 1 in comparison with the CNRs seen on precontrast images. During the precontrast stage and phase 1, the average difference in CNR was 2.691 for small HCCs and 0.801 for DNs the difference was thus significant (p<0.01). Quantitative analysis of CNR, reflecting the degree of nodule-to-liver enhancement in dynamic MR imaging, was found to be useful for the differentiation of small HCCs from DNs, both of which show high signal intensity on T1-weighted images

  10. Focal hepatic nodules with high signal intensity on T1-weighted MR imaging : differentiation of small hepatocellular carcinoma from dysplastic nodule by quantitative analysis of multi-phase contrast-enhanced dynamic MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kwang Hun; Yu, Jeong Sik; Kim, Ki Whang; Cho, Na Ri Ya; Jeong, Mi Gyoung; Kim, Jai Keun [Research Institute of Radiological Science, Yonsei Univ. College of Medicine, Seoul (Korea, Republic of)

    1999-06-01

    To evaluate the usefulness of quantitative analysis of the degree of enhancement in dynamic MR imaging used to differentiate dysplastic nodule (DN) from small hepatocellular carcinoma (HCC), both of which show high signal intensity on T1-weighted images. From 26 small HCCs and 71 DNs, all of which showed homogeneous high signal intensity on T1-weighted images among 42 patients with liver cirrhosis, we selected 16 small HCCs and 10 DNs of more than 1cm in diameter which were diagnosed by biopsy and follow-up imaging. Dynamic MR imaging of the entire liver was obtained using the breath-hold technique at postinjection 10 sec. (phase 1), 35 sec. (phase 2), 60 sec. (phase 3), and 5 min. (delayed) after intravenous manual injection of Gd-DTPA (0.1 mmol/kg) at a velocity of 3-4 cc/sec. Nodule-to-liver contrast-to-noise ratios (CNR) during each phase were calculated by measurement of the region of interest. On precontrast T1-weighted images, the mean CNR of small HCCs was 2.873, and that of DNs was 3.854, there was thus no significant statistical difference (p>0.01). On postcontrast images, the CNR of small HCCs during each phase was 5.565, 3.790, 1.704, and 1.282, with peak CNR phase 1 and a mostly decreasing trend thereafter. However, the CNR of DNs during each phase was 3.053, 1.561, 0.919, and 1.038 ; there was thus showed no significant increase during phase 1 in comparison with the CNRs seen on precontrast images. During the precontrast stage and phase 1, the average difference in CNR was 2.691 for small HCCs and 0.801 for DNs the difference was thus significant (p<0.01). Quantitative analysis of CNR, reflecting the degree of nodule-to-liver enhancement in dynamic MR imaging, was found to be useful for the differentiation of small HCCs from DNs, both of which show high signal intensity on T1-weighted images.

  11. Molecular alignment using circularly polarized laser pulses

    CERN Document Server

    Smeenk, C T L

    2013-01-01

    We show that circularly polarized femtosecond laser pulses produce field-free alignment in linear and planar molecules. We study the rotational wavepacket evolution of O$_2$ and benzene created by circularly polarized light. For benzene, we align the molecular plane to the plane of polarization. For O$_2$, we demonstrate that circular polarization yields a net alignment along the laser propagation axis at certain phases of the evolution. Circular polarization gives us the ability to control alignment of linear molecules outside the plane of polarization, providing new capabilities for molecular imaging.

  12. Circular migration patterns and determinants in Nairobi slum settlements

    Directory of Open Access Journals (Sweden)

    Donatien Beguy

    2010-09-01

    Full Text Available This paper measures migration flows and determinants in two slum settlements in Nairobi City between 2003 and 2007. The results confirm the high intensity of migration with a quarter of the total slum population and a third of those aged 15-30 being renewed annually. A circular migration system is at play whereby the majority of slum dwellers are short-term migrants spending on average less than 3 years in the area. Migration is more intense during early adulthood (20-24, and despite very similar determinants across gender, mobility is more intense among women compared to men. The increasing feminization of migration is likely to change the face of slum settlements, resulting in more balanced sex ratios, in line with city-wide trends in Nairobi over the past half century. The high population turnover is due to the insecurity of livelihoods, tenure, and poor basic amenities and social services in slum settlements.

  13. La raó circular

    OpenAIRE

    Pinyol i Bori, Francesc

    2007-01-01

    És un text epistemològic sobre les qüestions cognitives circulars que apareixen: a) Quan el subjecte forma part de l'objecte estudiat; b) En la recerca de les bases del coneixement; c) Al voler justificar la inducció; d) En algunes interpretacions filosòfiques i científiques. S'hi explica l'estat del punt a) el més problemàtic, i s'aclareixen els altres tres punts: els b) i c) pel fet científic que l'evolució cognitiva humana ha anat acoblada a l'evolució biològica, la qual ha generat els a p...

  14. The Circular RFQ Storage Ring

    International Nuclear Information System (INIS)

    This paper presents a novel idea of storage ring for the accumulation of intense beams of light and heavy ions at low energy. The new concept is a natural development of the combined features of conventional storage rings and ion traps, and is basically a linear RFQ bent on itself. The advantages are: smaller beam dimensions, higher beam intensity, and a more compact storage device

  15. The circular RFQ storage ring

    International Nuclear Information System (INIS)

    This paper presents a novel idea of storage ring for the accumulation of intense beams of light and heavy ions at low energy. The new concept is a natural development of the combined features used in a conventional storage ring and an ion trap, and is basically a linear RFQ bend on itself. In summary the advantages are: smaller beam dimensions, higher beam intensity, and a more compact storage device

  16. Multiphoton ionization of the hydrogen atom exposed to circularly or linearly polarized laser pulses

    International Nuclear Information System (INIS)

    This paper studies the multiphoton ionization of the hydrogen atom exposed to the linearly or circularly polarized laser pulses by solving the time-dependent Schrödinger equation. It finds that the ratio of the ionization probabilities by linearly and circularly polarized laser pulses varies with the numbers of absorbing photons. With the same laser intensity, the circularly polarized laser pulse favors to ionize the atom with more ease than the linearly polarized laser pulse if only two or three photons are necessary to be absorbed. For the higher order multiphoton ionization, the linearly polarized laser pulse has the advantage over circularly polarized laser pulse to ionize the atom. (atomic and molecular physics)

  17. Countermeasures for Circular Agricultural Development of Chongqing Based on AHP Approach

    Institute of Scientific and Technical Information of China (English)

    Taiyan; YANG; Shuo; BAI; Shunqiang; SUN

    2014-01-01

    With rapid economic development,resource and environment problems become more and more prominent. Chongqing Municipality, as a city focusing on industrial development in the past,has serious problem of environmental pollution and scarce agricultural resources. At present,it is urgent to find out how to develop circular agriculture and coordinate economic,social,environmental development. On the basis of understanding the intension of circular agriculture,this paper built evaluation indicator system for development of circular agriculture from social and economic development,resource reduction input,resource recycling use,and resource and environment safety. Then,it made an evaluation of circular agricultural development of Chongqing Municipality by AHP approach combined with gray correlation analysis. Finally,it came up with countermeasures,including reducing input of agricultural production materials,strengthening land management,promoting scientific and technological progress,and improving policy systems.

  18. Microstrip Antenna Generates Circularly Polarized Beam

    Science.gov (United States)

    Huang, J.

    1986-01-01

    Circular microstrip antenna excited with higher order transverse magnetic (TM) modes generates circularly polarized, conical radiation patterns. Found both theoretically and experimentally that peak direction of radiation pattern is varied within wide angular range by combination of mode selection and loading substrate with materials of different dielectric constants.

  19. Circular Loudspeaker Array with Controllable Directivity

    DEFF Research Database (Denmark)

    Møller, Martin; Olsen, Martin; Agerkvist, Finn T.;

    2010-01-01

    Specific directivity patterns for circular arrays of loudspeakers can be achieved by utilizing the concept of phase-modes, which expands the directivity pattern into a series of circular harmonics. This paper investigates the applicability of this concept applied on a loudspeaker array on a...

  20. QED cascades induced by circularly polarized laser fields

    CERN Document Server

    Elkina, N V; Kostyukov, I Yu; Legkov, M V; Narozhny, N B; Nerush, E N; Ruhl, H

    2010-01-01

    The results of Monte-Carlo simulations of electron-positron-photon cascades initiated by slow electrons in circularly polarized fields of ultra-high strength are presented and discussed. Our results confirm previous qualitative estimations [A.M. Fedotov, et al., PRL 105, 080402 (2010)] of the formation of cascades. This sort of cascades has revealed the new property of the restoration of energy and dynamical quantum parameter due to the acceleration of electrons and positrons by the field and may become a dominating feature of laser-matter interactions at ultra-high intensities. Our approach incorporates radiation friction acting on individual electrons and positrons.

  1. The Nonlinear Instability Modes of Dished Shallow Shells under Circular Line Loads

    Directory of Open Access Journals (Sweden)

    Liu Chang-Jiang

    2011-01-01

    Full Text Available This paper investigated the nonlinear stability problem of dished shallow shells under circular line loads. We derived the dimensionless governing differential equations of dished shallow shell under circular line loads according to the nonlinear theory of plates and shells and solved the governing differential equations by combing the free-parameter perturbation method (FPPM with spline function method (SFM to analyze the nonlinear instability modes of dished shallow shell under circular line loads. By analyzing the nonlinear instability modes and combining with concrete computational examples, we obtained the variation rules of the maximum deflection area of initial instability with different geometric parameters and loading action positions and discussed the relationship between the initial instability area and the maximum deflection area of initial instability. The results obtained from this paper provide some theoretical basis for engineering design and instability prediction and control of shallow-shell structures.

  2. CIRCULAR ECONOMY IN ROMANIA WITHIN EUROPEAN CONTEXT

    Directory of Open Access Journals (Sweden)

    Cornelia Marcela Danu

    2015-07-01

    Full Text Available In the present paper we have approached some conceptual and coordinated marks of the societal reality connected to the circular economy. Generated by „the limits of certainty” regarding the future of the world business, the operationalization of the circular economy has become a part of the EU strategies and started the various stages of implementation as an active process in all countries. We have highlighted the opportunities and the risks related to the circular economy, the European dimension and, in particular, the Romanian one of this process, the role of the triad: consumer-company-natural environment, while implementing the circular economy. Circular economy is both a new approach of the societal life, based on changing the mentalities of the individuals having the role of decision makers at the company level and public administration and the decision makers – consumers, as well as a policy meant to be made operational across all entities: governmental, entrepreneurial, individually – human.

  3. Gauge-Invariant Formulation of Circular Dichroism.

    Science.gov (United States)

    Raimbault, Nathaniel; de Boeij, Paul L; Romaniello, Pina; Berger, J A

    2016-07-12

    Standard formulations of magnetic response properties, such as circular dichroism spectra, are plagued by gauge dependencies, which can lead to unphysical results. In this work, we present a general gauge-invariant and numerically efficient approach for the calculation of circular dichroism spectra from the current density. First we show that in this formulation the optical rotation tensor, the response function from which circular dichroism spectra can be obtained, is independent of the origin of the coordinate system. We then demonstrate that its trace is independent of the gauge origin of the vector potential. We also show how gauge invariance can be retained in practical calculations with finite basis sets. As an example, we explain how our method can be applied to time-dependent current-density-functional theory. Finally, we report gauge-invariant circular dichroism spectra obtained using the adiabatic local-density approximation. The circular dichroism spectra we thus obtain are in good agreement with experiment. PMID:27295541

  4. Nanofocusing in circular sector-like nanoantennas

    DEFF Research Database (Denmark)

    Zenin, Volodymyr; Pors, Anders Lambertus; Han, Zhanghua;

    2014-01-01

    Gold circular sector-like nanoantennas (with a radius of 500 nm and a taper angle of 60°, 90°, and 120°) on glass are investigated in a near-infrared wavelength range (900 - 2100 nm). Amplitude- and phase-resolved near-field images of circular sector-like antenna modes at telecom wavelength feature...... a concentric circular line of phase contrast, demonstrating resonant excitation of a standing wave of counter-propagating surface plasmons, travelling between a tip and opposite circular edge of the antenna. Transmission spectra obtained in the range 900 - 2100 nm are in good agreement with...... makes circular sector-like nanoantennas very promising for implementing bowtie antennas and attractive for many applications....

  5. Sound Intensity

    DEFF Research Database (Denmark)

    Crocker, M.J.; Jacobsen, Finn

    This chapter is an overview, intended for readers with no special knowledge about this particular topic. The chapter deals with all aspects of sound intensity and its measurement from the fundamental theoretical background to practical applications of the measurement technique.......This chapter is an overview, intended for readers with no special knowledge about this particular topic. The chapter deals with all aspects of sound intensity and its measurement from the fundamental theoretical background to practical applications of the measurement technique....

  6. Sound intensity

    DEFF Research Database (Denmark)

    Crocker, Malcolm J.; Jacobsen, Finn

    This chapter is an overview, intended for readers with no special knowledge about this particular topic. The chapter deals with all aspects of sound intensity and its measurement from the fundamental theoretical background to practical applications of the measurement technique.......This chapter is an overview, intended for readers with no special knowledge about this particular topic. The chapter deals with all aspects of sound intensity and its measurement from the fundamental theoretical background to practical applications of the measurement technique....

  7. Numerical Solution of Stokes Flow in a Circular Cavity Using Mesh-free Local RBF-DQ

    DEFF Research Database (Denmark)

    Kutanaai, S Soleimani; Roshan, Naeem; Vosoughi, A; Saghafi, S; Barari, Amin; Soleimani, Soheil

    2012-01-01

    This work reports the results of a numerical investigation of Stokes flow problem in a circular cavity as an irregular geometry using mesh-free local radial basis function-based differential quadrature (RBF-DQ) method. This method is the combination of differential quadrature approximation of der...

  8. Circular dichroism in laser-assisted proton-hydrogen collisions

    International Nuclear Information System (INIS)

    Full text: We investigated the effects of a strong circularly polarized 1064 nm laser field on electron capture and emission in slow (keV) proton-hydrogen collisions within a reduced-dimensionality model of the scattering system in which both the motion of the active electron and the laser electric field vector are confined to the scattering plane. During the collision, the proton is assumed to move on a straight-line trajectory with impact parameter b. The rotating laser electric field breaks the azimuthal symmetry, and the projectile either follows the rotating laser field ('co-rotating' collisions) or moves against the rotating electric field ('counter-rotating' collisions). By solving the time-dependent Schroedinger equation, we examined the probabilities for electron capture and ionization as a function of laser intensity, impact parameter, and the laser phase that determines the orientation of the laser electric field with respect to the internuclear axis at the time of closest approach between target and projectile. Our results for the b-dependent ionization and capture probabilities show a strong dependence on the helicity of the circularly polarized laser light. For intensities above 2x1012 W/cm2, our model predicts a noticeable circular dichroism in the capture probability. Interestingly, this dichroism persists after averaging over . Capture and electron emission probabilities defer significantly from results for laser-unassisted collisions. Furthermore, we find evidence for a charge resonance enhanced ionization mechanism that may enable the measurement of the absolute laser phase φ. For a fixed impact parameter, the capture probability as a function of φ shows large amplitude oscillations and differs from the field-free results most strikingly at φ = 0o and 180o. It displays a strong dichroism effect, i.e., a substantial difference in the electron capture probability for co-rotating as compared to counter-rotating collisions. Ionization

  9. Breaking the fault tree circular logic

    International Nuclear Information System (INIS)

    Event tree - fault tree approach to model failures of nuclear plants as well as of other complex facilities is noticeably dominant now. This approach implies modeling an object in form of unidirectional logical graph - tree, i.e. graph without circular logic. However, genuine nuclear plants intrinsically demonstrate quite a few logical loops (circular logic), especially where electrical systems are involved. This paper shows the incorrectness of existing practice of circular logic breaking by elimination of part of logical dependencies and puts forward a formal algorithm, which enables the analyst to correctly model the failure of complex object, which involves logical dependencies between system and components, in form of fault tree. (author)

  10. Entanglement of quantum circular states of light

    Science.gov (United States)

    Horoshko, D. B.; De Bièvre, S.; Kolobov, M. I.; Patera, G.

    2016-06-01

    We present a general approach to calculating the entanglement of formation for superpositions of two-mode coherent states, placed equidistantly on a circle in phase space. We show that in the particular case of rotationally invariant circular states the Schmidt decomposition of two modes, and therefore the value of their entanglement, are given by analytical expressions. We analyze the dependence of the entanglement on the radius of the circle and number of components in the superposition. We also show that the set of rotationally invariant circular states creates an orthonormal basis in the state space of the harmonic oscillator, and this basis is advantageous for representation of other circular states of light.

  11. Symmetric Circular Matchings and RNA Folding

    DEFF Research Database (Denmark)

    Hofacker, Ivo L.; Reidys, Christian; Stadler, Peter F.

    2012-01-01

    RNA secondary structures can be computed as optimal solutions of certain circular matching problems. An accurate treatment of this energy minimization problem has to account for the small --- but non-negligible --- entropic destabilization of secondary structures with non-trivial automorphisms....... Such intrinsic symmetries are typically excluded from algorithmic approaches, however, because the effects are small, they play a role only for RNAs with symmetries at sequence level, and they appear only in particular settings that are less frequently used in practical application, such as circular...... asymptotic results for both the circular and the co-folding version are derived....

  12. Circular polarization memory in polydisperse scattering media

    CERN Document Server

    Macdonald, Callum M; Meglinski, Igor

    2015-01-01

    We investigate the survival of circularly polarized light in random scattering media. The surprising persistence of this form of polarization has a known dependence on the size and refractive index of scattering particles, however a general description regarding polydisperse media is lacking. Through analysis of Mie theory, we present a means of calculating the magnitude of circular polarization memory in complex media, with total generality in the distribution of particle sizes and refractive indices. Quantification of this memory effect enables an alternate pathway towards recovering particle size distribution, based on measurements of diffusing circularly polarized light.

  13. 77 FR 42077 - Environmental Justice: Final Circular

    Science.gov (United States)

    2012-07-17

    ... social service providers to identify transportation challenges and mitigation strategies. FTA is... Register notice (76 FR 60590). II. Chapter-by-Chapter Analysis A. General Comments This section addresses... Circular does not contain any new responsibilities for recipients. Recipients' responsibilities...

  14. Dual frequency launcher for circularly polarized antenna

    Science.gov (United States)

    Chen, Ming H.

    1989-10-01

    A dual frequency antenna feed is formed from a central, circular waveguide connected to the flat boundry of circular, disk-shaped resonant cavity. A second circular waveguide is connected one end of a disk-shaped resonant cavity. Energy of one frequency enters and exits the cavity along the common axis of the waveguides. Energy of the second frequency is introduced to the same resonant cavity by way of a plurality of bandpass filters, also connected to the cavity. This energy enters by way of slots in the cylindrical walls of the cavity. The central circular waveguide is propagating at one frequency but cut off at the second frequency. These bandpass filters are at this pass band for the second frequency, but at the rejection band for the first frequency. Therefore, the isolation between these two input ports are obtained.

  15. Radiative trapping in intense laser beams

    Science.gov (United States)

    Kirk, J. G.

    2016-08-01

    The dynamics of electrons in counter-propagating, circularly polarized laser beams are shown to exhibit attractors whose ability to trap particles depends on the ratio of the beam intensities and a single parameter describing radiation reaction. Analytical expressions are found for the underlying limit cycles and the parameter range in which they are stable. In high-intensity optical pulses, where radiation reaction strongly modifies the trajectories, the production of collimated gamma-rays and the initiation of non-linear cascades of electron–positron pairs can be optimized by a suitable choice of the intensity ratio.

  16. Radiative trapping in intense laser beams

    CERN Document Server

    Kirk, J G

    2016-01-01

    The dynamics of electrons in counter-propagating, circularly polarized laser beams are shown to exhibit attractors whose ability to trap particles depends on the ratio of the beam intensities and a single parameter describing radiation reaction. Analytical expressions are found for the underlying limit cycles and the parameter range in which they are stable. In high-intensity optical pulses, where radiation reaction strongly modifies the trajectories, the production of collimated gamma-rays and the initiation of non-linear cascades of electron-positron pairs can be optimized by a suitable choice of the intensity ratio.

  17. Unleashing the Power of the Circular Economy

    Energy Technology Data Exchange (ETDEWEB)

    Kok, L.; Wurpel, G.; Ten Wolde, A. [IMSA Amsterdam, Amsterdam (Netherlands)

    2013-04-15

    The concept of circular economy is an economic and industrial system that focuses on the reusability of products and raw materials, reduces value destruction in the overall system and aims at value creation within each tier of the system. This report for Circle Economy (CE) outlines the general direction and concrete steps that must be taken to accomplish a breakthrough to a circular economy. It also provides a knowledge base behind the concept, connecting it to sustainability.

  18. Construction of Circular Economy Industrial System

    Institute of Scientific and Technical Information of China (English)

    Cao Man; Ye Wenhu

    2007-01-01

    It is difficult to realize the transformation from traditional economy industrial system to circular economy industrial system.Regarding primary raw materials as the indicators,the industrial system has been specified according to the divergence among the indicators and the circular utilization modes.In comparison with the association among industrial systems,the relationship among industrial sub-systems is named as industrial cross-linking in this paper.The industrial system which could completely utilize and recycle the indicators should be increased and strengthened,and the circular economy industrial system with complete industrial association and industrial cross-linking should also be constructed.Taking the development of circular agricultural system basing on the traditional agricultural system as an example,the traditional agricultural products are regarded as the indicators which have been divided into foodstuff and crop straws which are used to produce food and articlesfor use,like fertilizer,energy and papers etc.The way to construct the circular agricultural industrial system is to increase the industrial systems that could utilize the products generated from crop straws,feces and other castoffs and transform the wastewater and other trucks into environmental friendly products.It has also been pointed out that the construction of circular economy industrial system is conducive to the foundation of circular industrial economics and the establishment of the construction layout of circular economy and the application schemes.Suggestions to the theoretical and practical work of the next step have also been brought forward in this paper.

  19. A Conceptual Framework for Circular Design

    Directory of Open Access Journals (Sweden)

    Mariale Moreno

    2016-09-01

    Full Text Available Design has been recognised in the literature as a catalyst to move away from the traditional model of take-make-dispose to achieve a more restorative, regenerative and circular economy. As such, for a circular economy to thrive, products need to be designed for closed loops, as well as be adapted to generate revenues. This should not only be at the point of purchase, but also during use, and be supported by low-cost return chains and reprocessing structures, as well as effective policy and regulation. To date, most academic and grey literature on the circular economy has focused primarily on the development of new business models, with some of the latter studies addressing design strategies for a circular economy, specifically in the area of resource cycles and design for product life extension. However, these studies primarily consider a limited spectrum of the technical and biological cycles where materials are recovered and restored and nutrients (e.g., materials, energy, water are regenerated. This provides little guidance or clarity for designers wishing to design for new circular business models in practice. As such, this paper aims to address this gap by systematically analysing previous literature on Design for Sustainability (DfX (e.g., design for resource conservation, design for slowing resource loops and whole systems design and links these approaches to the current literature on circular business models. A conceptual framework is developed for circular economy design strategies. From this conceptual framework, recommendations are made to enable designers to fully consider the holistic implications for design within a circular economy.

  20. Dual-band Omnidirectional Circularly Polarized Antenna

    OpenAIRE

    Narbudowicz, Adam; Bao, Xiulong; Ammann, Max

    2013-01-01

    A dual-band omnidirectional circularly polarized antenna is proposed. The antenna comprises back-to-back microstrip patches fed by a coplanar waveguide. A very low frequency ratio of 1.182 has been achieved, which can be easily tuned by adjusting four lumped capacitors incorporated into the antenna. An analysis of the omnidirectional circular polarization mechanism as well the dual band operation is provided and confirmed by numerical and experimental data. Key parameters to tune the resonant...

  1. Single particle dynamics in circular accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Ruth, R.D.

    1986-10-01

    The purpose of this paper is to introduce the reader to the theory associated with the transverse dynamics of single particle, in circular accelerators. The discussion begins with a review of Hamiltonian dynamics and canonical transformations. The case of a single particle in a circular accelerator is considered with a discussion of non-linear terms and chromaticity. The canonical perturbation theory is presented and nonlinear resonances are considered. Finally, the concept of renormalization and residue criterion are examined. (FI)

  2. CIRCULAR RIBBON FLARES AND HOMOLOGOUS JETS

    International Nuclear Information System (INIS)

    Solar flare emissions in the chromosphere often appear as elongated ribbons on both sides of the magnetic polarity inversion line (PIL), which has been regarded as evidence of a typical configuration of magnetic reconnection. However, flares having a circular ribbon have rarely been reported, although it is expected in the fan-spine magnetic topology involving reconnection at a three-dimensional (3D) coronal null point. We present five circular ribbon flares with associated surges, using high-resolution and high-cadence Hα blue wing observations obtained from the recently digitized films of Big Bear Solar Observatory. In all the events, a central parasitic magnetic field is encompassed by the opposite polarity, forming a circular PIL traced by filament material. Consequently, a flare kernel at the center is surrounded by a circular flare ribbon. The four homologous jet-related flares on 1991 March 17 and 18 are of particular interest, as (1) the circular ribbons brighten sequentially, with cospatial surges, rather than simultaneously, (2) the central flare kernels show an intriguing 'round-trip' motion and become elongated, and (3) remote brightenings occur at a region with the same magnetic polarity as the central parasitic field and are co-temporal with a separate phase of flare emissions. In another flare on 1991 February 25, the circular flare emission and surge activity occur successively, and the event could be associated with magnetic flux cancellation across the circular PIL. We discuss the implications of these observations combining circular flare ribbons, homologous jets, and remote brightenings for understanding the dynamics of 3D magnetic restructuring.

  3. On the circular polarization of pulsar radiation

    OpenAIRE

    Lyubarskii, Y. E.; Petrova, S. A.

    1999-01-01

    We consider the polarization behaviour of radio waves propagating through an ultrarelativistic highly magnetized electron-positron plasma in a pulsar magnetosphere. The rotation of magnetosphere gives rise to the wave mode coupling in the polarization-limiting region. The process is shown to cause considerable circular polarization in the linearly polarized normal waves. Thus, the circular polarization observed for a number of pulsars, despite the linear polarization of the emitted normal wav...

  4. Angle-resolved x-ray circular and magnetic circular dichroisms: Definitions and applications

    OpenAIRE

    Tong, DSY; X Guo; Tobin, JG; Waddill, GD

    1996-01-01

    We introduce definitions of angle-resolved x-ray circular dichroism (ARXCD) and magnetic x-ray circular dichroism (ARMXCD). As defined, the much larger effect of circular dichroism (ARXCD) is separated from the smaller magnetic (ARMXCD) effect. In all materials, ARXCD is zero along mirror planes while nonzero elsewhere. ARMXCD is nonzero only in magnetic materials. The measurement and analysis of ARMXCD allow element specific surface magnetism and surface structure as well as their inter-rela...

  5. Broadband circularly polarized planar antenna using partially covered circular wide-slot and L-probe

    OpenAIRE

    Fukusako, Takeshi; Sakami, Ryo; Iwata, Kazuki; フクサコ, タケシ; サカミ, リョウ; イワタ, カズキ; 福迫, 武; 酒見, 遼; 岩田, 一樹

    2008-01-01

    The novel structure of a unique circularly polarized broadband antenna that combines an L-shaped probe with a partially covered circular slot has been presented. A principle that can be used to generate CP using the proposed structure has been presented using an L-shaped probe and a modified circular wide slot. Using the above, a 3 -dB AR bandwidth of 58% and matching bandwidth of 57% were obtained at 3.2 GHz.

  6. Separation of closed circular DNA from linear DNA by electrophoresis in two dimensions in agarose gels.

    OpenAIRE

    Oppenheim, A

    1981-01-01

    A method that provides an easy, rapid, and reproducible way for separating closed circular DNA species from linear DNA and nicked circles is described. The method is based on the difference in mobility of form I (supercoiled) DNA and form II (nicked circles), and the differential mobility of relaxed circular DNA in the presence and absence of ethidium bromide (EtdBr). It can be used for detection or for purification of plasmid, episomal, or viral DNA from the bulk of cellular DNA, or from oth...

  7. Semi-Analytical Solution of Functionally Graded Circular Short Hollow Cylinder Subject to Transient Thermal Loading

    Directory of Open Access Journals (Sweden)

    Eskandari Jam Jafar

    2014-12-01

    Full Text Available In this paper, by using a semi-analytical solution based on multi-layered approach, the authors present the solutions of temperature, displacements, and transient thermal stresses in functionally graded circular hollow cylinders subjected to transient thermal boundary conditions. The cylinder has finite length and is subjected to axisymmetric thermal loads. It is assumed that the functionally graded circular hollow cylinder is composed of N fictitious layers and the properties of each layer are assumed to be homogeneous and isotropic. Time variations of the temperature, displacements, and stresses are obtained by employing series solving method for ordinary differential equation, Laplace transform techniques and a numerical Laplace inversion.

  8. Exciton circular dichroism in channelrhodopsin.

    Science.gov (United States)

    Pescitelli, Gennaro; Kato, Hideaki E; Oishi, Satomi; Ito, Jumpei; Maturana, Andrés Daniel; Nureki, Osamu; Woody, Robert W

    2014-10-16

    Channelrhodopsins (ChRs) are of great interest currently because of their important applications in optogenetics, the photostimulation of neurons. The absorption and circular dichroism (CD) spectra of C1C2, a chimera of ChR1 and ChR2 of Chlamydomonas reinhardtii, have been studied experimentally and theoretically. The visible absorption spectrum of C1C2 shows vibronic fine structure in the 470 nm band, consistent with the relatively nonpolar binding site. The CD spectrum has a negative band at 492 nm (Δε(max) = -6.17 M(-1) cm(-1)) and a positive band at 434 nm (Δε(max) = +6.65 M(-1) cm(-1)), indicating exciton coupling within the C1C2 dimer. Time-dependent density functional theory (TDDFT) calculations are reported for three models of the C1C2 chromophore: (1) the isolated protonated retinal Schiff base (retPSB); (2) an ion pair, including the retPSB chromophore, two carboxylate side chains (Asp 292, Glu 162), modeled by acetate, and a water molecule; and (3) a hybrid quantum mechanical/molecular mechanical (QM/MM) model depicting the binding pocket, in which the QM part consists of the same ion pair as that in (2) and the MM part consists of the protein residues surrounding the ion pair within 10 Å. For each of these models, the CD of both the monomer and the dimer was calculated with TDDFT. For the dimer, DeVoe polarizability theory and exciton calculations were also performed. The exciton calculations were supplemented by calculations of the coupling of the retinal transition with aromatic and peptide group transitions. For the dimer, all three methods and three models give a long-wavelength C2-axis-polarized band, negative in CD, and a short-wavelength band polarized perpendicular to the C2 axis with positive CD, differing in wavelength by 1-5 nm. Only the retPSB model gives an exciton couplet that agrees qualitatively with experiment. The other two models give a predominantly or solely positive band. We further analyze an N-terminal truncated mutant

  9. PLANAR MOTION OF A SLIGHTLY DISTORTED CIRCULAR CYLINDER AROUND ANOTHER CIRCULAR ONE

    Institute of Scientific and Technical Information of China (English)

    SUN Ren; CHWANG Allen T.

    2004-01-01

    Accurate prediction of the motion of a body moving around another one in an unbounded fluid and determi-nation of the hydrodynamic interaction between them are im-portant in the coastal and offshore engineering. For two-dimensional cases, most of the previous studies were focused on the interaction between circular cylinders without considering the non-circular situation. To break through the limitation of"circular" bodies, in the present paper the boundary perturbation method was employed to investigate the motion of a slightly distorted circular cylinder around a circular one. An approximate complex velocity potential in terms of double infinite series expanded at two singular points was derived using the method of continued fractions. The hydrodynamic interaction between two cylinders was computed by solving the dynamical equations of motion. In a relative coordinate system moving with the uniform stream, the kinetic energy of the fluid was expressed as a function of fifteen added masses. Approximate analytical solutions of added masses in the series form were obtained and applied to determine the trajectories of the slightly distorted circular cylinder around a fixed circular one. Numerical results show that the presence of the circular cylinder affects the planar motion of the slightly distorted cirular cylinder and the initial configuration of the slightly distorted circular cylinder has a decisive influence on the development of its rotational motion.

  10. Propagation of intense laser pulses in strongly magnetized plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Yang, X. H., E-mail: xhyang@nudt.edu.cn; Ge, Z. Y.; Xu, B. B.; Zhuo, H. B.; Ma, Y. Y.; Shao, F. Q. [College of Science, National University of Defense Technology, Changsha 410073 (China); Yu, W., E-mail: weiyu@mail.shcnc.ac.cn [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Xu, H. [School of Computer Science, National University of Defense Technology, Changsha 410073 (China); Yu, M. Y., E-mail: myyu@zju.edu.cn [Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 (China); Institut für Theoretische Physik I, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Borghesi, M. [School of Mathematics and Physics, Queen' s University of Belfast, Belfast BT7 1NN (United Kingdom)

    2015-06-01

    Propagation of intense circularly polarized laser pulses in strongly magnetized inhomogeneous plasmas is investigated. It is shown that a left-hand circularly polarized laser pulse propagating up the density gradient of the plasma along the magnetic field is reflected at the left-cutoff density. However, a right-hand circularly polarized laser can penetrate up the density gradient deep into the plasma without cutoff or resonance and turbulently heat the electrons trapped in its wake. Results from particle-in-cell simulations are in good agreement with that from the theory.

  11. Intensive mobilities:

    DEFF Research Database (Denmark)

    Vannini, Phillip; Bissell, David; Jensen, Ole B.

    This paper explores the intensities of long distance commuting journeys as a way of exploring how bodily sensibilities are being changed by the mobilities that they undertake. The context of this paper is that many people are travelling further to work than ever before owing to a variety of factors...... which relate to transport, housing and employment. Yet we argue that the experiential dimensions of long distance mobilities have not received the attention that they deserve within geographical research on mobilities. This paper combines ideas from mobilities research and contemporary social theory...... with fieldwork conducted in Canada, Denmark and Australia to develop our understanding of the experiential politics of long distance workers. Rather than focusing on the extensive dimensions of mobilities that are implicated in patterns and trends, our paper turns to the intensive dimensions of this...

  12. Surface plasmon resonance coupled circular dichroism of DNA–gold nanorods assembly

    International Nuclear Information System (INIS)

    Linker mediated self-assembly of gold nanoparticles is emerging as an interesting strategy for construction of hybrid nanoscale systems with enhanced plasmonic circular dichroism (PCD) signals. Herein, gold nanorods were assembled via DNA linker to investigate the possibility of signal enhancement. Assemblies were characterized by UV–visible, fluorescence, dynamic light scattering and circular dichroism (CD) spectroscopy. Hybridization of complementary strands resulted in PCD signal enhancement, which was further monitored by the increase of real time PicoGreen fluorescence intensity. Impressively, such changes in the real time fluorescence and plasmonic CD responses could be used as a new detection method for ultrasensitive sensors. (paper)

  13. Analytical Solutions of Temporal Evolution of Populations in Optically-Pumped Atoms with Circularly Polarized Light

    Directory of Open Access Journals (Sweden)

    Heung-Ryoul Noh

    2016-03-01

    Full Text Available We present an analytical calculation of temporal evolution of populations for optically pumped atoms under the influence of weak, circularly polarized light. The differential equations for the populations of magnetic sublevels in the excited state, derived from rate equations, are expressed in the form of inhomogeneous second-order differential equations with constant coefficients. We present a general method of analytically solving these differential equations, and obtain explicit analytical forms of the populations of the ground state at the lowest order in the saturation parameter. The obtained populations can be used to calculate lineshapes in various laser spectroscopies, considering transit time relaxation.

  14. OPERATIONAL CIRCULAR NO 6 - JUNE 2001 'CERN SCIENTIFIC DOCUMENTS'

    CERN Multimedia

    Human Resources Division

    2001-01-01

    This new operational circular has been drawn up. It cancels and replaces Administrative Circular N° 29 entitled "Principles and procedures governing CERN publications and reports and other publications arising from CERN work". Copies are available from Divisional Secretariats. Note : Administrative and operational circulars, as well as the lists of those in force, are available for consultation on WWW : ADMINISTRATIVE CIRCULARSOPERATIONAL CIRCULARS

  15. Researches on Relationship between Circular Agriculture and Industrial Diversity

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    First, this paper establishes the conceptual model of circular agriculture, conducts systematic analysis on the circular agriculture on the basis of conceptual model, and discusses the characteristics of closeness and openness of circular agriculture and relationship between closeness and openness of circular agriculture. Second, this paper introduces the industrial diversity related to circular agriculture, defines the concept of industry and the concept of industries related to agriculture, and illustrates the related industries that are conducive to circular agriculture and the related industries that are not conducive to circular agriculture. Finally, this paper analyzes the mutual relationship between circular agriculture and industrial diversity as follows: in the system of circular agriculture, the industrial diversity can transform the wastes in upstream industries into resources in downstream industries; the industrial diversity creates possibility for recycling of agricultural byproducts; the industrial diversity is conducive to the diversification of industries related to circular agriculture.

  16. Angular momentum-induced circular dichroism in non-chiral nanostructures

    CERN Document Server

    Zambrana-Puyalto, Xavier; Molina-Terriza, Gabriel

    2014-01-01

    Circular dichroism (CD), i.e. the differential response of a system to left and right circularly polarized light, is one of the only techniques capable of providing morphological information of certain samples. In biology, for instance, CD spectroscopy is widely used to study the structure of proteins. More recently, it has also been used to characterize metamaterials and plasmonic structures. Typically, CD can only be observed in chiral objects. Here, we present experimental results showing that a non-chiral sample such as a sub-wavelength circular nano-aperture can produce giant CD when a vortex beam is used to excite it. These measurements can be understood by studying the symmetries of the sample and the total angular momentum that vortex beams carry. Our results show that CD can provide a wealth of information about the sample when combined with the control of the total angular momentum of the input field.

  17. Non-Sequential Double Ionization by Counter Rotating Circularly Polarized Two-Color Laser Fields

    CERN Document Server

    Eckart, S; Kunitski, M; Hartung, A; Rist, J; Henrichs, K; Schlott, N; Kang, H; Bauer, T; Sann, H; Schmidt, L Ph H; Schöffler, M; Jahnke, T; Dörner, R

    2016-01-01

    We report on non-sequential double ionization of Ar by a laser pulse consisting of two counter rotating circularly polarized fields (390 nm and 780 nm). The double ionization probability depends strongly on the relative intensity of the two fields and shows a "knee"-like structure as function of intensity. We conclude that double ionization is driven by a beam of nearly monoenergetic recolliding electrons, which can be controlled in intensity and energy by the field parameters. The electron momentum distributions show the recolliding electron as well as a second electron which escapes from an intermediate excited state of Ar$^+$.

  18. A broadband, circular-polarization selective surface

    Science.gov (United States)

    Momeni Hasan Abadi, Seyed Mohamad Amin; Behdad, Nader

    2016-06-01

    We introduce a new technique for designing wideband circular-polarization selective surfaces (CPSSs) based on anisotropic miniaturized element frequency selective surfaces. The proposed structure is a combination of two linear-to-circular polarization converters sandwiching a linear polarizer. This CPSS consists of a number of metallic layers separated from each other by thin dielectric substrates. The metallic layers are in the form of two-dimensional arrays of subwavelength capacitive patches and inductive wire grids with asymmetric dimensions and a wire grid polarizer with sub-wavelength period. The proposed device is designed to offer a wideband circular-polarization selection capability allowing waves with left-hand circular polarization to pass through while rejecting those having right-hand circular polarization. A synthesis procedure is developed that can be used to design the proposed CPSS based on its desired band of operation. Using this procedure, a prototype of the proposed CPSS operating in the 12-18 GHz is designed. Full-wave electromagnetic simulations are used to predict the response of this structure. These simulation results confirm the validity of the proposed design concept and synthesis procedure and show that proposed CPSS operates within a fractional bandwidth of 40% with a co-polarization transmission discrimination of more than 15 dB. Furthermore, the proposed design is shown to be capable of providing an extremely wide field of view of ±60°.

  19. Environmental issues elimination through circular economy

    Science.gov (United States)

    Špirková, M.; Pokorná, E.; Šujanová, J.; Samáková, J.

    2016-04-01

    Environmental efforts of European Union are currently going towards circular economy. Tools like Extended Producer Responsibility and Eco-design were established. The circular economy deals with resources availability issue on one hand and waste management on the other hand. There are few pioneering companies all over the world with some kind of circular economy practice. Generally the concept is not very wide-spread. The paper aims to evaluate possibility of transition towards circular economy in Slovak industrial companies. They need to have an active approach to material treatment of their products after usage stage. Innovation is another important pre-condition for the transition. Main problem of current cradle to grave system is landfilling of valuable materials after one cycle of usage. Their potential value for next manufacturing cycles is lost. Companies may do not see connection between waste management and material resource prices and volatility of supplies. Municipalities are responsible for municipal waste collection and treatment in Slovakia. The circular economy operates by cradle to cradle principle. Company manages material flow until the material comes back to the beginning of manufacturing process by itself or by another partners. Stable material supplies with quite low costs are provided this way. It is necessary to deal with environmental problems in phase of product design. Questionnaire survey results show on one hand low involvement of industrial companies in waste management area, however on the other hand they are open to environmental innovations in future.

  20. A COMPACT CIRCULARLY POLARIZED SLOTTED MICROSTRIP ANTENNA

    Directory of Open Access Journals (Sweden)

    V. Jebaraj

    2014-12-01

    Full Text Available Slot antennas are often used at UHF and microwave frequencies. In slot antenna for RFID reader applications the frequency ranges from 902-923MHz to achieve circular polarization. The shapes and size of the slot, as well as the driving frequency, determine the radiation distribution pattern. The proposed compact size circularly polarized slotted microstrip antenna are summarized with design rules. The circularly polarized radiation in square patch antenna can be obtained by perturbation technique with different shapes of slot in the orthogonal direction. A single feed configuration based symmetric slotted microstrip antenna is adapted to realize the compact circularly polarized microstrip antennas. Based on the perimeter, the size of the slot on microstrip slot antenna are studied and compared. The Operating frequency of the antenna is 912MHz that can be tuned by varying the perimeter of the slot while the keeping the circularly polarized radiation unchanged. The schematic and layout are configured by using Advanced Design System (ADS. Return loss, Resonant Frequency, Axial Ratio (AR, and Gain were determined for the proposed system using ADS. A measured 3dB Axial Ratio (AR bandwidth around 6MHz with 16MHz impedance bandwidth has been achieved for the antenna on a RO3004C substrate with dielectric constant 3.38.

  1. Circular Ribbon Flares and Homologous Jets

    CERN Document Server

    Wang, Haimin

    2012-01-01

    Solar flare emissions in the chromosphere often appear as elongated ribbons on both sides of the magnetic polarity inversion line (PIL), and this has been regarded as evidence of a typical configuration of magnetic reconnection. However, flares having a closed circular ribbon have rarely been reported, although it is expected in the fan--spine magnetic topology involving reconnection at a three-dimensional (3D) coronal null point. We present five circular ribbon flares with associated surges, using high-resolution and high-cadence \\ha blue wing observations obtained from the recently digitized films of Big Bear Solar Observatory (BBSO). In all the events, a central parasitic magnetic field is encompassed by the opposite magnetic polarity, forming a circular PIL that is also traced by filament material. Consequently, a flare kernel at the center is surrounded by a circular flare ribbon. The four homologous jet-related flares on 1991 March 17 and 18 are of particular interest, as (1) the circular ribbons bright...

  2. Hollow circular-truncated cone resonator and its hollow variable biconical laser beam

    Science.gov (United States)

    Liu, Jinglun; Chen, Mei; Wang, Qionghua; Sun, Nianchun

    2014-05-01

    To obtain a hollow variable biconical laser beam (HVBLB), a CO2 laser having a hollow circular-truncated cone resonator (HCTCR) is presented. This HCTCR comprises a rotationally symmetric total-reflecting concave mirror at the bottom, a rotationally symmetric part-reflecting convex mirror at the top, and a hollow circular-truncated cone discharge tube at the middle. The cross section of this generated biconical laser beam changes from annulus to circular to annulus and the size of this cross section from big to small to large as the propagation distance increases. So, a kind of laser beam with variable center intensity from zero to peak value to zero is obtained and is known as HVBLB. Due to the inclusion of part of the hollow laser beam (HLB) and solid laser beam, this HVBLB requires no additional beam-shaping element and has broad applications such as optical trapping and commercial manufacturing.

  3. A study on flow characteristics with ultrasonic forcing in a coaxial circular pipe by PIV measurement

    Energy Technology Data Exchange (ETDEWEB)

    Koo, J.H.; Park, Y.H.; Choi, W.C.; Song, M.G. [Gyeongsang National University Graduate School, Jinju (Korea); Ju, E.S. [Gyeongsang National University, Jinju (Korea)

    2000-11-01

    An experiment on the enhancement of turbulent flow with ultrasonic forcing was carried out by using PIV measurement in a coaxial circular pipe which could offer characteristics of the turbulence flow plentifully through its jet. A large transparent acryl tank and a coaxial circular pipe nozzle were made for the above research. City water of 25 deg.C was selected as an experimental liquid and the front flow field of the coaxial circular pipe was divided vertically as 3 measuring regions to observe characteristics of flow phenomena. Characteristics of fluid flow such as velocity vector distribution, kinetic energy, turbulent intensity and etc. were visualized, observed, examined and considered at 5 kinds of Re No. such as Re=1 X 10{sup 3}, 2 X 10{sup 3}, 3 X 10{sup 3}, 5 X 10{sup 3}, 1 X 10{sup 4}. In result it was proved that ultrasonic vibration affected the enhancement of turbulent flow. (author). 12 refs., 6 figs.

  4. Geometry- and diffraction-independent ionization probabilities in intense laser fields: probing atomic ionization mechanisms with effective intensity matching

    OpenAIRE

    Bryan, W. A.; Stebbings, S. L.; English, E.M.L.; Goodworth, T. R. J.; Newell, W. R.; McKenna, J; Suresh, M.; Srigengan, B.; Williams, I. D.; Turcu, I. C. E.; Smith, J M; Divall, E. J.; Hooker, C. J.; Langley, A. J.

    2005-01-01

    We report a novel experimental technique for the comparison of ionization processes in ultrafast laser pulses irrespective of pulse ellipticity. Multiple ionization of xenon by 50 fs 790 nm, linearly and circularly polarized laser pulses is observed over the intensity range 10 TW/cm^2 to 10 PW/cm^2 using Effective Intensity Matching (EIM), which is coupled with Intensity Selective Scanning (ISS) to recover the geometry-independent probability of ionization. Such measurements, made possible by...

  5. Chiral Recognition of 2-Alkylalcohols with Magnetic Circular Dichroism Measurement of Porphyrin J-Aggregate on Silica Gel Plate.

    Science.gov (United States)

    Watarai, Hitoshi; Kurahashi, Yuriko

    2016-05-01

    Simple chiral recognition method of 2-alkylalcohols on a silica gel plate was proposed by using the induced circular dichroism (ICD) of J-aggregates of diprotonated tetraphenylporphyrin and magnetic circular dichroism (MCD) spectrometry. To the silica gel on a glass slide including a chiral 2-alkylalcohol and 4 M sulfuric acid, the porphyrin in toluene was added and mixed. Then, the glass slide was used for in situ MCD measurement. The observed ICD spectra could recognize well the chirality of the alcohols and the ICD intensity normalized by the MCD intensity of the J-aggregate correlated linearly to the amount of the chiral alcohols in the silica gel. PMID:27074095

  6. Circularly symmetric light scattering from nanoplasmonic spirals.

    Science.gov (United States)

    Trevino, Jacob; Cao, Hui; Dal Negro, Luca

    2011-05-11

    In this paper, we combine experimental dark-field imaging, scattering, and fluorescence spectroscopy with rigorous electrodynamics calculations in order to investigate light scattering from planar arrays of Au nanoparticles arranged in aperiodic spirals with diffuse, circularly symmetric Fourier space. In particular, by studying the three main types of Vogel's spirals fabricated by electron-beam lithography on quartz substrates, we demonstrate polarization-insensitive planar light diffraction in the visible spectral range. Moreover, by combining dark-field imaging with analytical multiparticle calculations in the framework of the generalized Mie theory, we show that plasmonic spirals support distinctive structural resonances with circular symmetry carrying orbital angular momentum. The engineering of light scattering phenomena in deterministic structures with circular Fourier space provides a novel strategy for the realization of optical devices that fully leverage on enhanced, polarization-insensitive light-matter coupling over planar surfaces, such as thin-film plasmonic solar cells, plasmonic polarization devices, and optical biosensors. PMID:21466155

  7. Analytical Optimization of Piezoelectric Circular Diaphragm Generator

    Directory of Open Access Journals (Sweden)

    S. Mohammadi

    2013-01-01

    Full Text Available This paper presents an analytical study of the piezoelectric circular diaphragm microgenerator using strain energy method. Piezoelectrics are the intelligent materials that can be used as transducer to convert mechanical energy into electrical energy and vice versa. The aim of this paper is to optimize produced electrical energy from mechanical pressure. Therefore, the circular metal plate equipped with piezoelectric circular patch has been considered with simply and clamped supports. A comprehensive modeling, parametrical study and the effect of the boundary conditions on the performance of the microgenerator have been investigated. The system is under variable pressure from an oscillating pressure source. Results are presented for PZT and PMN-PT piezoelectric materials with steel and aluminum substrates. An optimal value for the radius and thickness of the piezoelectric layer with a special support condition has been obtained.

  8. Charged Particle Optics in Circular Higgs Factory

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Yunhai [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-02-26

    Similar to a super B-factory, a circular Higgs factory will require strong focusing systems near the interaction points and a low-emittance lattice in arcs to achieve a factory luminosity. At electron beam energy of 120 GeV, beamstrahlung effects during the collision pose an additional challenge to the collider design. In particular, a large momentum acceptance at 2 percent level is necessary to retain an adequate beam lifetime. This turns out to be the most challenging aspect in the design of circular Higgs factory. In this paper, an example will be provided to illustrate the beam dynamics in circular Higgs factory, emphasizing on the chromatic optics. Basic optical modules and advanced analysis will be presented. Most important, we will show that 2% momentum aperture is achievable

  9. Circular object recognition based on shape parameters

    Institute of Scientific and Technical Information of China (English)

    Chen Aijun; Li Jinzong; Zhu Bing

    2007-01-01

    To recognize circular objects rapidly in satellite remote sensing imagery, an approach using their geometry properties is presented.The original image is segmented to be a binary one by one dimension maximum entropy threshold algorithm and the binary image is labeled with an algorithm based on recursion technique.Then, shape parameters of all labeled regions are calculated and those regions with shape parameters satisfying certain conditions are recognized as circular objects.The algorithm is described in detail, and comparison experiments with the randomized Hough transformation (RHT) are also provided.The experimental results on synthetic images and real images show that the proposed method has the merits of fast recognition rate, high recognition efficiency and the ability of anti-noise and anti-jamming.In addition, the method performs well when some circular objects are little deformed and partly misshapen.

  10. Chaotic Motion of Corrugated Circular Plates

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Large deflection theory of thin anisotropic circular plates was used to analyze the bifurcation behavior and chaotic phenomena of a corrugated thin circular plate with combined transverse periodic excitation and an in-plane static boundary load. The nonlinear dynamic equation for the corrugated plate was derived by employing Galerkin's technique. The critical conditions for occurrence of the homoclinic and subharmonic bifurcations as well as chaos were studied theoretically using the Melnikov function method. The chaotic motion was also simulated numerically using Maple, with the Poincaré map and phase curve used to evaluate when chaotic motion appears. The results indicate some chaotic motion in the corrugated plate. The method is directly applicable to chaotic analysis of an isotropic circular plate.

  11. Underwater Shock Response of Circular HSLA Steel Plates

    Directory of Open Access Journals (Sweden)

    R. Rajendran

    2000-01-01

    Full Text Available Studies on shock response of circular plates subjected to underwater explosion is of interest to ship designers. Non-contact underwater explosion experiments were carried out on air backed circular High Strength Low Alloy (HSLA steel plates of 4 mm thickness and 290 mm diameter. The experiments were carried out in two phases. In the first phase, strain gauges were fixed at intervals of 30 mm from the centre of the plate and strains were recorded for the shock intensity gradually increasing to yielding. Semi-analytical models were derived for the elastic strain prediction which showed good agreement with the experiments. Dynamic yield stress and the shock factor for yielding were established. In the second phase, individual plates were subjected to increasing shock severity until fracture and the apex bulge depth and the thickness strains were measured. Empirical models were derived to predict the plastic deformation which were validated through a fresh set of experiments. Analysis of the fractured surface by visual examination showed that there was slant fracture indicating ductile mode of failure and the same was corroborated by Scanning Electron Microscopic (SEM examination.

  12. Spin dynamics of electron beams in circular accelerators

    International Nuclear Information System (INIS)

    Experiments using high energy beams of spin polarized, charged particles still prove to be very helpful in disclosing a deeper understanding of the fundamental structure of matter. An important aspect is to control the beam properties, such as brilliance, intensity, energy, and degree of spin polarization. In this context, the present studies show various numerical calculations of the spin dynamics of high energy electron beams in circular accelerators. Special attention has to be paid to the emission of synchrotron radiation, that occurs when deflecting charged particles on circular orbits. In the presence of the fluctuation of the kinetic energy due to the photon emission, each electron spin moves non-deterministically. This stochastic effect commonly slows down the speed of all numeric estimations. However, the shown simulations cover - using appropriate approximations - trackings for the motion of thousands of electron spins for up to thousands of turns. Those calculations are validated and complemented by empirical investigations at the electron stretcher facility ELSA of the University of Bonn. They can largely be extended to other boundary conditions and thus, can be consulted for new accelerator layouts.

  13. Domain structure of circular and ring magnets

    International Nuclear Information System (INIS)

    We present the results of a study of the domain structure and the magnetization reversal processes in arrays of circular and ring magnets, obtained by magnetic force microscopy and magnetization measurements. The particles, with outer diameter 0.55 and 2.2 μm, were made of Permalloy films of thickness 24 and 66 nm. In the circular elements two domain configurations were observed: a vortex structure with perpendicular magnetization at the core and a 'bud' state. In the ring elements the domain structure was found to depend on the ring width: a flux closed state was formed in wide rings and the 'onion' state was observed in narrow rings

  14. Circular economy in China and recommendations

    Institute of Scientific and Technical Information of China (English)

    Zhou Hongchun

    2006-01-01

    @@ It is an overall, urgent and long-term strategic task for China to vigorously develop the circular economy and build a resource-saving and environmental-friendly society. China is now at the accelerating stage of industrialization and urbanization.Lower per-capita resource amount and tendency of environmental deterioration has not been fundamentally averted. Therefore a circular economy development is an inevitable choice to realize the goal of building a well-off society, ensure sustainable development of national economy, and coordinate the relationship between mankind and nature.

  15. Circularly polarized U-Slot antenna

    OpenAIRE

    Tong, K. F.; Wong, T P

    2007-01-01

    Circularly polarized single-layer U-slot microstrip patch antenna has been proposed. The suggested asymmetrical U-slot can generate the two orthogonal modes for circular polarization without chamfering any corner of the probe-fed square patch microstrip antenna. A parametric study has been carried out to investigate the effects caused by different arm lengths of the U-slot. The thickness of the foam substrate is about 8.5% of the wavelength at the operating frequency. The 3 dB axial ratio ban...

  16. Broadband Suspended Microstrip Antenna For Circular Polarization

    OpenAIRE

    Kasabegoudar, VG; Vinoy, KJ

    2009-01-01

    In this paper we propose a circularly polarized (CP) microstrip antenna on a suspended substrate with a coplanar capacitive feed and a slot within the rectangular patch. The antenna has an axial ratio bandwidth (< 3 dB) of 7.1%. The proposed antenna exhibits a much higher impedance bandwidth of about 49% (S11 < -10 dB) and also yields return loss better than -15 dB in the useful range of circular polarization. Measured characteristics of the antenna are in good agreement with the simulated re...

  17. Free vibrations of circular cylindrical shells

    CERN Document Server

    Armenàkas, Anthony E; Herrmann, George

    2013-01-01

    Free Vibrations of Circular Cylindrical Shells deals with thin-walled structures that undergo dynamic loads application, thereby resulting in some vibrations. Part I discusses the treatment of problems associated with the propagation of plane harmonic waves in a hollow circular cylinder. In such search for solutions, the text employs the framework of the three-dimensional theory of elasticity. The text explains the use of tables of natural frequencies and graphs of representative mode shapes of harmonic elastic waves bounding in an infinitely long isotropic hollow cylinder. The tables are

  18. Circularly Polarized Luminescence from Simple Organic Molecules.

    Science.gov (United States)

    Sánchez-Carnerero, Esther M; Agarrabeitia, Antonia R; Moreno, Florencio; Maroto, Beatriz L; Muller, Gilles; Ortiz, María J; de la Moya, Santiago

    2015-09-21

    This article aims to show the identity of "circularly polarized luminescent active simple organic molecules" as a new concept in organic chemistry due to the potential interest of these molecules, as availed by the exponentially growing number of research articles related to them. In particular, it describes and highlights the interest and difficulty in developing chiral simple (small and non-aggregated) organic molecules able to emit left- or right-circularly polarized light efficiently, the efforts realized up to now to reach this challenging objective, and the most significant milestones achieved to date. General guidelines for the preparation of these interesting molecules are also presented. PMID:26136234

  19. Rectangular-to-circular groove waveguide junction

    Institute of Scientific and Technical Information of China (English)

    CUI; Licheng; (崔立成); YANG; Hongsheng; (杨鸿生)

    2003-01-01

    Mode matching method is used to analyze the scattering characteristics of the rectangular-to-circular groove waveguide junction. Firstly, the scattering matrix equation is obtained by matching the electromagnetic fields at the boundary of the junction. The scattering coefficients can be obtained from the equation. Secondly the scattering characteristics of the iris with rectangular window positioned in circular groove waveguide are briefly analyzed. Thirdly, the convergent problem is discussed and the numerical results are given. At last experiment is made and good agreement is found between the calculated results and the measured results.

  20. Electron Interference in Molecular Circular Polarization Attosecond XUV Photoionization

    Directory of Open Access Journals (Sweden)

    Kai-Jun Yuan

    2015-01-01

    Full Text Available Two-center electron interference in molecular attosecond photoionization processes is investigated from numerical solutions of time-dependent Schrödinger equations. Both symmetric H\\(_2^+\\ and nonsymmetric HHe\\(^{2+}\\ one electron diatomic systems are ionized by intense attosecond circularly polarized XUV laser pulses. Photoionization of these molecular ions shows signature of interference with double peaks (minima in molecular attosecond photoelectron energy spectra (MAPES at critical angles \\(\\vartheta_c\\ between the molecular \\(\\textbf{R}\\ axis and the photoelectron momentum \\(\\textbf{p}\\. The interferences are shown to be a function of the symmetry of electronic states and the interference patterns are sensitive to the molecular orientation and pulse polarization. Such sensitivity offers possibility for imaging of molecular structure and orbitals.

  1. Interpreting tunneling time in circularly polarized strong-laser ionization

    CERN Document Server

    Yuan, MingHu; Chu, TianShu; Liu, HongPing

    2016-01-01

    We propose a method to study the tunneling process by analyzing the time-dependent ionization yield in circularly polarized laser. A numerical calculation shows that for an atom exposed to a long laser pulse, if its initial electronic state wave function is non-spherical symmetric, the delayed phase shift of the ionization rate vs. the laser cycle period in real time in the region close to the peak intensity of the laser pulse can be used to probe the tunneling time. In this region, an obvious delay phase shift is observed, showing the tunneling time is in order of tens of attoseconds. Further study shows the atom has a longer tunneling time in the ionization under a shorter wavelength laser pulse. In our method, a Wigner rotation technique is employed to numerically solve the time-dependent Schr\\"odinger equation of a single-active-electron in a three dimensional spherical coordinate system.

  2. Interaction between heat dipole and circular interracial crack

    Institute of Scientific and Technical Information of China (English)

    Wan-shen XIAO; Chao XIE; You-wen LIU

    2009-01-01

    The heat dipole consists of a heat source and a heat sink. The problem of an interfacial crack of a composite containing a circular inclusion under a heat dipole is investigated by using the analytical extension technique, the generalized Liouville theo-rem, and the Muskhelishvili boundary value theory. Temperature and stress fields are formulated. The effects of the temperature field and the inhomogeneity on the interracial fracture are analyzed. As a numerical illustration, the thermal stress intensity factors of the interfacial crack are presented for various material combinations and different po-sitions of the heat dipole. The characteristics of the interfacial crack depend on the elasticity, the thermal property of the composite, and the condition of the dipole.

  3. Differential rotation on both components of the pre main-sequence binary system HD 155555

    CERN Document Server

    Dunstone, N J; Cameron, A Collier; Marsden, S C; Jardine, M; Barnes, J R; Vlex, J C Ramirez; Donati, J -F

    2008-01-01

    We present the first measurements of surface differential rotation on a pre-main sequence binary system. Using intensity (Stokes I) and circularly polarised (Stokes V) timeseries spectra, taken over eleven nights at the Anglo-Australian Telescope (AAT), we incorporate a solar-like differential rotation law into the surface imaging process. We find that both components of the young, 18 Myr, HD 155555 (V824 Ara, G5IV + K0IV) binary system show significant differential rotation. The equator-pole laptimes as determined from the intensity spectra are 80 days for the primary star and 163 days for the secondary. Similarly for the magnetic spectra we obtain equator-pole laptimes of 44 and 71 days respectively, showing that the shearing timescale of magnetic regions is approximately half that found for stellar spots. Both components are therefore found to have rates of differential rotation similar to those of the same spectral type main sequence single stars. The results for HD 155555 are therefore in contrast to tho...

  4. Vibronic Coupling Explains the Different Shape of Electronic Circular Dichroism and of Circularly Polarized Luminescence Spectra of Hexahelicenes.

    Science.gov (United States)

    Liu, Yanli; Cerezo, Javier; Mazzeo, Giuseppe; Lin, Na; Zhao, Xian; Longhi, Giovanna; Abbate, Sergio; Santoro, Fabrizio

    2016-06-14

    We present the simulation of the absorption (ABS), electronic circular dichroism (ECD), emission (EMI), and circularly polarized luminescence (CPL) spectra for the weak electronic transition between the ground (S0) and the lowest excited state (S1) of hexahelicene, 2-methylhexahelicene, 2-bromohexahelicene, and 5-azahexahelicene. Vibronic contributions have been computed at zero Kelvin and at room temperature in harmonic approximation including Duschinsky effects and accounting for both Franck-Condon and Herzberg-Teller contributions. Our results nicely capture the effects of the different substituents on the experimental spectra. They also show that HT effects dominate the shape of ECD and CPL spectra where they even induce changes of signs; HT effects are also relevant in ABS and EMI, tuning the relative intensities of the different vibronic bands. HT effects are the main reason for the differences in the line shapes of ABS and ECD and of EMI and CPL spectra and for the mirror-symmetry breaking between ABS and EMI and between ECD and CPL spectra. In order to check the robustness of our results, given also that few examples of calculations of vibronic CPL spectra exist, we adopted both adiabatic and vertical approaches to define the model potential energy surfaces of the (S0) and the (S1) states; moreover we expanded the electric and magnetic dipole transition moments around both the S0 and S1 equilibrium geometries. PMID:27120334

  5. MHD mixed convection flow through a diverging channel with heated circular obstacle

    Science.gov (United States)

    Alam, Md. S.; Shaha, J.; Khan, M. A. H.; Nasrin, R.

    2016-07-01

    A numerical study of steady MHD mixed convection heat transfer and fluid flow through a diverging channel with heated circular obstacle is carried out in this paper. The circular obstacle placed at the centre of the channel is hot with temperature Th. The top and bottom walls are non-adiabatic. The basic nonlinear governing partial differential equations are transformed into dimensionless ordinary differential equations using similarity transformations. These equations have been solved numerically for different values of the governing parameters, namely Reynolds number (Re), Hartmann number (Ha), Richardson number (Ri) and Prandtl number (Pr) using finite element method. The streamlines, isotherms, average Nusselt number and average temperature of the fluid for various relevant dimensionless parameters are displayed graphically. The study revealed that the flow and thermal fields in the diverging channel depend significantly on the heated body. In addition, it is observed that the magnetic field acts to increase the rate of heat transfer within the channel.

  6. Beam Dynamics and Beam Losses - Circular Machines

    CERN Document Server

    Kain, V

    2016-01-01

    A basic introduction to transverse and longitudinal beam dynamics as well as the most relevant beam loss mechanisms in circular machines will be presented in this lecture. This lecture is intended for physicists and engineers with little or no knowledge of this subject.

  7. The Global Future Circular Colliders Effort

    CERN Document Server

    Benedikt, Michael

    2013-01-01

    This presentation has been given during the P5 Workshop at BNL Brookhaven (US). It contains - Global Future Circular Collier Studies Overview and Status - Main challenges and R&D areas for hadron collider - Main challenges and R&D areas for lepton collider - Conclusions

  8. Circular Vibration Planing of Inconel 718

    Science.gov (United States)

    Hettiarachchi, Nandita Kalyanakumara; Moriwaki, Toshimichi; Shibasaka, Toshiro; Nakamoto, Keiichi

    Circular vibration milling (CVM) is achieved by vibrating a milling cutter about the machine tool spindle axis in a circular path, in addition to its rotary motion. CVM has been proven capable of producing better surface finishes on difficult to cut materials. However, the CVM process is far slower than conventional milling process. In circular vibration planing (CVP) process, the cutting tool is clamped without rotation and fed at a speed comparable to the feed speed of conventional milling. By superimposing circular vibration motion, necessary cutting speed could be achieved keeping the feed speed at realistic values. Inconel 718 was machined by CVP and conventional milling at a similar feed rate. It was observed that CVP could reduce tool wear and hence produce better surface finishes than conventional milling. A geometric simulation showed a major difference between uncut chip shapes of the two processes. The difference of uncut chip shapes suggests that in CVP process, less rubbing occurs between tool flank face and work before the tool penetrates in to the work to form a chip. The reduced rubbing of the flank face is proposed as the reson for reduced tool wear in CVP when compared with conventional milling.

  9. Numerical simulation of flow past circular duct

    Directory of Open Access Journals (Sweden)

    Ze-gao YIN

    2010-06-01

    Full Text Available On the basis of Fluent software, Renormalization Group (RNGk-ε turbulent model and Volume of Fluid (VOF method are employed to simulate the flow past circular duct to obtain and analyze the hydraulic parameters. According to various upper and bottom gap-ratios, the force on duct is calculated. Firstly, when bottom gap-ratio is 0, drag force coefficient, lift force coefficient and composite force reach the maximum respectively and azimuth reaches the minimum. Secondly, with the increase of bottom gap-ratio from 0 to 1, drag force coefficient and composite force decrease sharply, lift force coefficient decreases a little, but azimuth increases dramatically. Thirdly, with the continuous increase of bottom gap-ratio from 1, drag force coefficient, lift force coefficient, composite force and azimuth vary little. So, bottom gap-ratio is the key factor influencing the force on circular duct. When bottom gap-ratio is less than 1, upper gap-ratio has the remarkable influence on the circular duct force. When bottom gap-ratio is greater than 1, the varation of upper gap-ratio has a little influence on the circular duct force.

  10. Dynamics of the circular bosonic string

    International Nuclear Information System (INIS)

    After a brief discussion about the Nambu-Goto action, we introduce the concept of transverse velocity and find it for a closed circular bosonic string, then we study and solve the string's equations of movement by using the energy conservation law and finally we sketch its corresponding world sheet. (author).

  11. Discrete Fresnel Transform and Its Circular Convolution

    CERN Document Server

    Ouyang, Xing; Gunning, Fatima; Zhang, Hongyu; Guan, Yong Liang

    2015-01-01

    Discrete trigonometric transformations, such as the discrete Fourier and cosine/sine transforms, are important in a variety of applications due to their useful properties. For example, one well-known property is the convolution theorem for Fourier transform. In this letter, we derive a discrete Fresnel transform (DFnT) from the infinitely periodic optical gratings, as a linear trigonometric transform. Compared to the previous formulations of DFnT, the DFnT in this letter has no degeneracy, which hinders its mathematic applications, due to destructive interferences. The circular convolution property of the DFnT is studied for the first time. It is proved that the DFnT of a circular convolution of two sequences equals either one circularly convolving with the DFnT of the other. As circular convolution is a fundamental process in discrete systems, the DFnT not only gives the coefficients of the Talbot image, but can also be useful for optical and digital signal processing and numerical evaluation of the Fresnel ...

  12. Helically corrugated circular waveguides as antenna feeders

    Science.gov (United States)

    Jecko, F.; Papiernik, A.

    1983-07-01

    Rotation of the plane of polarization of the TE(11)-mode is predicted and observed in a helically corrugated circular waveguide. Rotation is suppressed by a longitudinal deformation produced on the corrugation. This modified structure can be used as an antenna feeder with low losses.

  13. Numerical simulation of flow past circular duct

    Institute of Scientific and Technical Information of China (English)

    Ze-gao YIN; Xian-wei Cao; Hong-da SHI; Jian MA

    2010-01-01

    The Renormalization Group(RNG)k-ε turbulence model and Volume of Fluid(VOF)method were employed to simulate the flow past a circular duct in order to obtain and analyze hydraulic parameters.According to various upper and bottom gap ratios,the force on the duct was calculated.When the bottom gap ratio is 0,the drag force coefficient,lift force coefficient,and composite force reach their maximum values,and the azimuth reaches its minimum.With an increase of the bottom gap ratio from 0 to 1,the drag force coefficient and composite force decrease sharply,and the lift force coefficient does not decreases so much,but the azimuth increases dramatically.With a continuous increase of the bottom gap ratio from 1 upward,the drag force coefficient,lift force coefficient,composite force,and azimuth vary little.Thus,the bottom gap ratio is the key factor influencing the force on the circular duct.When the bottom gap ratio is less than 1,the upper gap ratio has a remarkable influence on the force of the circular duct.When the bottom gap ratio is greater than 1,the variation of the upper gap ratio has little influence on the force of the circular duct.

  14. Oblique stability of circularly polarized MHD waves

    International Nuclear Information System (INIS)

    The stability of finite-amplitude weakly dispersive circularly polarized MHD wave trains with respect to oblique modulations is investigated. The mathematical model is a multi-dimensional extension of the DNLS equation. It is found that the right-hand-polarized wave, which is stable with respect to parallel modulations, is unstable with respect to certain oblique modulations for most primary wavenumbers. (author)

  15. Time can't be circular

    CERN Multimedia

    2003-01-01

    "Delivering the Albert Einstein lecture at the Centre for Philosophy and Foundations of Science on Tuesday, Nobel Laureate Professor Gerard Hooft said that any notion of time can not be circular or have loops or multi dimensionality" (1/2 page).

  16. Nuclear spin circular dichroism in fullerenes

    Czech Academy of Sciences Publication Activity Database

    Straka, Michal

    Brno : Masaryk University Press, 2015 - (Sklenář, V.). s. 153 ISBN 978-80-210-7890-1. [EUROMAR 2015. 05.07.2015-10.07.2015, Praha] R&D Projects: GA ČR(CZ) GA14-03564S Institutional support: RVO:61388963 Keywords : nuclear spin circular dichroism * fullerenes Subject RIV: CF - Physical ; Theoretical Chemistry

  17. Vibrational circular dichroism of nucleic acids

    Czech Academy of Sciences Publication Activity Database

    Andrushchenko, Valery; Wieser, H.; Bouř, Petr

    Brescia, 2009. s. 60-60. [International Conference on Circular Dichroism /12./. Interdisciplinary Symposium on Biological Chirality /5./. 30.08.2009-04.09.2009, Brescia] Institutional research plan: CEZ:AV0Z40550506 Keywords : VCD * G-quadruplex Subject RIV: CF - Physical ; Theoretical Chemistry

  18. Self-organization in circular shear layers

    DEFF Research Database (Denmark)

    Bergeron, K.; Coutsias, E.A.; Lynov, Jens-Peter;

    1996-01-01

    Experiments on forced circular shear layers performed in both magnetized plasmas and in rotating fluids reveal qualitatively similar self-organization processes leading to the formation of patterns of coherent vortical structures with varying complexity. In this paper results are presented from...

  19. CIRCULAR CHROMATIC NUMBER AND MYCIELSKI GRAPHS

    Institute of Scientific and Technical Information of China (English)

    Liu Hongmei

    2006-01-01

    For a general graph G, M(G) denotes its Mycielski graph. This article gives a number of new sufficient conditions for G to have the circular chromatic number xc (M(G))equals to the chromatic number x(M(G)), which have improved some best sufficient conditions published up to date.

  20. Applications of circularly polarized photons at the ALS with a bend magnet source

    Energy Technology Data Exchange (ETDEWEB)

    1992-02-01

    The purpose of this workshop is to focus attention on, and to stimulate the scientific exploitation of, the natural polarization properties of bend-magnet synchrotron radiation at the ALS -- for research in biology, materials science, physics, and chemistry. The topics include: The Advanced Light Source; Magnetic Circular Dichroism and Differential Scattering on Biomolecules; Tests of Fundamental Symmetries; High {Tc} Superconductivity; Photoemission from Magnetic and Non-magnetic Solids; Studies of Highly Correlated Systems; and Instrumentation for Photon Transport and Polarization Measurements.

  1. Applications of circularly polarized photons at the ALS with a bend magnet source

    International Nuclear Information System (INIS)

    The purpose of this workshop is to focus attention on, and to stimulate the scientific exploitation of, the natural polarization properties of bend-magnet synchrotron radiation at the ALS -- for research in biology, materials science, physics, and chemistry. The topics include: The Advanced Light Source; Magnetic Circular Dichroism and Differential Scattering on Biomolecules; Tests of Fundamental Symmetries; High Tc Superconductivity; Photoemission from Magnetic and Non-magnetic Solids; Studies of Highly Correlated Systems; and Instrumentation for Photon Transport and Polarization Measurements

  2. Laser shaping of a relativistic circularly polarized pulse by laser foil interaction

    International Nuclear Information System (INIS)

    Laser shaping of a relativistic circularly polarized laser pulse in ultra-intense laser thin-foil interaction is investigated by theoretical analysis and particle-in-cell simulations. It is found that the plasma foil as a nonlinear optical shutter has an obvious cut-out effect on the laser temporal and spatial profiles. Two-dimensional particle-in-cell simulations show that the high intensity part of a Gaussian laser pulse can be well extracted from the whole pulse. The transmitted pulse with longitudinal steep rise front and transverse super-Gaussian profile is thus obtained which would be beneficial for the radiation pressure acceleration regime. The Rayleigh-Taylor-like instability is observed in the simulations, which destroys the foil and results in the cut-out effect of the pulse in the rise front of a circularly polarized laser

  3. Propagation of radially polarized beams diffracted at a circular aperture in turbulent atmosphere

    Science.gov (United States)

    Jia, Xinting; Yang, Yingping

    2012-12-01

    Based on the extended Huygens-Fresnel integral and the beam coherence-polarization matrix, the analytical formulae for the average intensity and the degree of polarization of the radially polarized beams diffracted at a circular aperture in turbulent atmosphere are derived, which provide a convenient approach to study the propagation and polarization properties of the apertured radially polarized beams in turbulent atmosphere. The unapertured and free-space cases can be viewed as the special cases of our general result. The analyses indicate that the average intensity and the degree of polarization are closely related to the propagation distance, the structure constant of the atmospheric turbulence, and the truncation parameter. The existence of the circular aperture weakens the influence of the atmospheric turbulence on the evolution properties of the radially polarized beams.

  4. Mechanistic Analysis of Rock Damage Anisotropy and Rotation Around Circular Cavities

    Science.gov (United States)

    Xu, Hao; Arson, Chloé

    2015-11-01

    We used the differential stress-induced damage (DSID) model to predict anisotropic crack propagation under tensile and shear stress. The damage variable is similar to a crack density tensor. The damage function and the damage potential are expressed as functions of the energy release rate, defined as the thermodynamic force that is work-conjugate to damage. Contrary to the previous damage models, flow rules are obtained by deriving dissipation functions by the energy release rate, and thermodynamic consistency is ensured. The damage criterion is adapted from the Drucker-Prager yield function. Simulations of biaxial stress tests showed that: (1) three-dimensional states of damage can be obtained for three-dimensional states of stress; (2) no damage propagates under isotropic compression; (3) crack planes propagate in the direction parallel to major compression stress; (4) damage propagation hardens the material; (5) stiffness and deformation anisotropy result from the anisotropy of damage. There is no one-to-one relationship between stress and damage. We demonstrated the effect of the loading sequence in a two-step simulation (a shear loading phase and a compression loading phase): the current state of stress and damage can be used to track the effect of stress history on damage rotation. We finally conducted a sensitivity analysis with the finite element method, to explore the stress conditions in which damage is expected to rotate around a circular cavity subject to pressurization or depressurization. Simulation results showed that: (1) before damage initiation, the DSID model matches the analytical solution of stress distribution obtained with the theory of elasticity; (2) the DSID model can predict the extent of the tensile damage zone at the crown, and that of the compressive damage zone at the sidewalls; (3) damage generated during a vertical far-field compression followed by a depressurization of the cavity is more intense than that generated during a

  5. Solid Angle Computations for a Circular Radiator and a Circular Detector

    International Nuclear Information System (INIS)

    The problem of particle detection, when using an isotropic neutron point source at different distances from a circular target or a radioactive source as seen by a circular detector, e. g. a solid state counter, is dealt with. Tables are given for different distances of the source when the reaction at the target has an isotropic or a cosine angular distribution in the laboratory system

  6. A simple circular-polarized antenna: Circular waveguide horn coated with lossy magnetic material

    Science.gov (United States)

    Lee, Choon S.; Justice, D. W.; Lee, Shung-Wu

    1988-02-01

    It is shown that a circular waveguide horn coated with a lossy material in its interior wall can be used as an alternative to a corrugated waveguide for radiating a circularly polarized (CP) field. To achieve good CP radiation, the diameter of the structure must be larger than the free-space wavelength, and the coating material must be sufficiently lossy and magnetic. The device is cheaper and lighter in weight than the corrugated one.

  7. Mode Ⅰ Plane Crack Interacting with an Interfacial Crack Along a Circular Inhomogeneity

    Institute of Scientific and Technical Information of China (English)

    WANG Rui; MA Jian-jun; LIU Zheng-guang

    2006-01-01

    The elastic interaction of the mode Ⅰ plane crack with an interfacial crack along a circular inhomogeneity is dealt with. The dislocation density and the stress intensity factors (SIFs) of the mode I plane crack are obtained numerically. A new kind of dislocation equilibrium equation about the plane crack is applied. The influence of some material parameters on the dislocation density and SIFs are analyzed.

  8. Deep subsurface waveguides with circular cross section produced by femtosecond laser writing

    OpenAIRE

    Diez-Blanco, V.; Siegel, Jan; A. Ferrer; Ruiz de la Cruz, A.; Solís Céspedes, Javier

    2007-01-01

    A combination of low numerical aperture focusing optics, in order to minimize spherical aberration, and beam shaping with a slit has been used to produce waveguides in fused silica by femtosecond laser writing. Waveguides with circular cross section and low losses are produced over a large depth window (>7 mm) without changing any experimental parameter. Diffraction induces beam divergence along the axis perpendicular to the slit, leading to a shift of the focal plane. The focal intensity dis...

  9. Relativistic Propagation of Linearly/Circularly Polarized Laser Radiation in Plasmas

    OpenAIRE

    Sonu Sen; Meenu Asthana Varshney; Dinesh Varshney

    2013-01-01

    Paraxial theory of relativistic self-focusing of Gaussian laser beams in plasmas for arbitrary magnitude of intensity of the beam has been presented in this paper. The nonlinearity in the dielectric constant arises on account of relativistic variation of mass. An appropriate expression for the nonlinear dielectric constant has been used to study laser beam propagation for linearly/circularly polarized wave. The variation of beamwidth parameter with distance of propagation, self-trapping condi...

  10. Flat Plate Wake Velocity Statistics Obtained With Circular And Elliptic Trailing Edges

    Science.gov (United States)

    Rai, Man Mohan

    2016-01-01

    The near wake of a flat plate with circular and elliptic trailing edges is investigated with data from direct numerical simulations. The plate length and thickness are the same in both cases. The separating boundary layers are turbulent and statistically identical. Therefore the wake is symmetric in the two cases. The emphasis in this study is on a comparison of the wake-distributions of velocity components, normal intensity and fluctuating shear stress obtained in the two cases.

  11. Homotopy analysis method for mixed convective boundary layer flow of a nanofluid over a vertical circular cylinder

    OpenAIRE

    Dinarvand Saeed; Abbassi Abbas; Hosseini Reza; Pop Ioan

    2015-01-01

    This article deals with the study of the steady axisymmetric mixed convective boundary layer flow of a nanofluid over a vertical circular cylinder with prescribed external flow and surface temperature. By means of similarity transformation, the governing partial differential equations are reduced into highly non-linear ordinary differential equations. The resulting non-linear system has been solved analytically using an efficient technique namely homotopy a...

  12. Circular Economy Development Mode Based on System Theory

    Institute of Scientific and Technical Information of China (English)

    Xiao Huamao; Wang Fengqi

    2007-01-01

    The paper tries to explore circular economy from the viewpoint of the system theory.Circular economy is a kind of complicated economic acdvity,and it is a wholly new ecotype economy pmposed by Western countries after they had summed up many experiences and lessons from traditional economy.It is an entirety and has many layers.It keeps an open and dynamic balance.Because the system theory is the theoretical foundation of circular economy,we should systemically analyze and study circular economy from the macroscopic view,correctly grasp its operational laws,improve its service functions,and realize human beings's ustainable development.The paper introduces the content and general characteristics of the system theory and the idea of circular economy.Then it analyzes circular economy based on the systemtheory.The paper concludes that the intonation of circular economy and the system theory can promote the functions of circular economy.

  13. SOME RESULTS ON CIRCULAR PERFECT GRAPHS AND PERFECT GRAPHS

    Institute of Scientific and Technical Information of China (English)

    XU Baogang

    2005-01-01

    An r-circular coloring of a graph G is a map f from V(G) to the set of open unit intervals of an Euclidean circle of length r,such that f(u) ∩ f(v) = φ whenever uv ∈ E(G).Circular perfect graphs are defined analogously to perfect graphs by means of two parameters,the circular chromatic number and the circular clique number.In this paper,we study the properties of circular perfect graphs.We give (1) a necessary condition for a graph to be circular perfect,(2) some circular critical imperfect graphs,and (3) a characterization of graphs with the property that each of their induced subgraphs has circular clique number the same as its clique number,and then the two conjectures that are equivalent to the perfect graph conjecture.

  14. Beaming circularly polarized photons from quantum dots coupled with plasmonic spiral antenna.

    Science.gov (United States)

    Rui, Guanghao; Chen, Weibin; Abeysinghe, Don C; Nelson, Robert L; Zhan, Qiwen

    2012-08-13

    Coupling nanoscale emitters via optical antennas enables comprehensive control of photon emission in terms of intensity, directivity and polarization. In this work we report highly directional emission of circularly polarized photons from quantum dots coupled to a spiral optical antenna. The structural chirality of the spiral antenna imprints spin state to the emitted photons. Experimental results reveal that a circular polarization extinction ratio of 10 is obtainable. Furthermore, increasing the number of turns of the spiral gives rise to higher antenna gain and directivity, leading to higher field intensity and narrower angular width of emission pattern in the far field. For a five-turn Archimedes' spiral antenna, field intensity increase up to 70-fold simultaneously with antenna directivity of 11.7 dB has been measured in the experiment. The highly directional circularly polarized photon emission from such optically coupled spiral antenna may find important applications in single molecule sensing, quantum optics information processing and integrated photonic circuits as a nanoscale spin photon source. PMID:23038571

  15. Molecular alignment from circular dichroic photoelectron angular distributions in (n+1) resonance enhanced multiphoton ionization

    International Nuclear Information System (INIS)

    The theory for determination of molecular alignment from circular dichroism in photoelectron angular distributions is generalized to treat the case in which the excitation polarization direction and the laboratory z axis do not coincide. A new method of data analysis is presented here. Alignment created by surface scattering or photofragmentation should be obtainable by these procedures. For studies of orientation with elliptically polarized excitation, differential cross sections at a given collection angle are found to be, to a good approximation, independent of excited-state alignment. Orientation can thus be obtained from differential cross sections by the methods developed by Kummel, Sitz, and Zare [J. Chem. Phys. 88, 6707 (1988)

  16. Chirality and Circular Polarization in Models of Inflation

    CERN Document Server

    Alexander, Stephon; Sims, Robert

    2016-01-01

    We investigate the possibility that a chiral asymmetry during inflation can manifest as net circular polarization in photons. Using an example known to produce a helicity imbalance in fermions, we show that superhorizon photon modes produced during inflation acquire net circular polarization. Modes that reenter the horizon around last scattering can thermalize into the Cosmic Microwave Background while retaining a portion of their net circular polarization. We also consider the possibility of direct detection of the circular polarization in the CMB.

  17. Novel X band Compact Waveguide Dual Circular Polarizer

    CERN Document Server

    Xu, Chen; Wang, Juwen

    2014-01-01

    A novel type of dual circular polarizer is developed to convert the TE10 mode into two different polarization TE11 modes in a circular waveguide. This design consists two major parts: a TE10 to TE10/TE20 converter and an overmoded TE10/TE20 to circular TE11 modes converter.

  18. Photoinduced Circular Anisotropy in Side-Chain Azobenzene Polyesters

    DEFF Research Database (Denmark)

    Nikolova, L.; Todorov, T.; Ivanov, M.;

    1997-01-01

    We report for the first time the inducing of large circular anisotropy in previously unoriented films of side-chain azobenzene polyesters on illumination with circularly polarized light at a wavelength of 488 nm. The circular dichroism and optical activity are measured simultaneously in real time...

  19. Generalized M2 factor of a partially coherent beam propagating through a circular hard-edged aperture.

    Science.gov (United States)

    Chu, Xiaoliang; Zhang, Bin; Wen, Qiao

    2003-07-20

    The second-order intensity moments and the beam-propagation M2 factor of partially coherent beams that propagate through a circular-symmetry hard-edged aperture are in the cylindrical coordinate system. AJo-correlated Schell-model beam with a Gaussian intensity distribution is an example. The analytical expression for the generalized M2 factor is derived. The numerical calculation results are analyzed. PMID:12921275

  20. Shock structure in non-circular jets

    Science.gov (United States)

    Morris, Philip J.; Bhat, Thonse R. S.

    1989-01-01

    The shock-cell structure of supersonic jets with non-circular exit geometry is modeled using a linearized analysis. The model takes into account the finite thickness of the jet shear layer using realistic velocity and density profiles. The effects of the shear layer turbulence are included by incorporating eddy-viscosity terms. A finite-difference numerical method is used to solve the steady linearized equations of motion. A body-fitted coordinate system is used to describe the shear layer. The variation of the pressure fluctuation with downstream distance is given for circular jets and for an elliptic jet of aspect ratio 2.0. Comparisons with experimental data are made. Difficulties with the numerical technique are also discussed.

  1. The Biogenesis of Nascent Circular RNAs

    Directory of Open Access Journals (Sweden)

    Yang Zhang

    2016-04-01

    Full Text Available Steady-state circular RNAs (circRNAs have been mapped to thousands of genomic loci in mammals. We studied circRNA processing using metabolic tagging of nascent RNAs with 4-thiouridine (4sU. Strikingly, the efficiency of circRNA processing from pre-mRNA is extremely low endogenously. Additional studies revealed that back-splicing outcomes correlate with fast RNA Polymerase II elongation rate and are tightly controlled by cis-elements in vivo. Additionally, prolonged 4sU labeling in cells shows that circRNAs are largely processed post-transcriptionally and that circRNAs are stable. Circular RNAs that are abundant at a steady-state level tend to accumulate. This is particularly true in cells, such as neurons, that have slow division rates. This study uncovers features of circRNA biogenesis by investigating the link between nascent circRNA processing and transcription.

  2. Circular machine design techniques and tools

    International Nuclear Information System (INIS)

    Some of the basic optics principles involved in the design of circular accelerators such as Alternating Gradient Synchrotrons, Storage and Collision Rings, and Pulse Stretcher Rings are outlined. Typical problems facing a designer are defined, and the main references and computational tools are reviewed that are presently available. Two particular classes of problems that occur typically in accelerator design are listed - global value problems, which affect the control of parameters which are characteristic of the complete closed circular machine, and local value problems. Basic mathematical formulae are given that are considered useful for a first draft of a design. The basic optics building blocks that can be used to formulate an initial machine design are introduced, giving only the elementary properties and transfer matrices only in one transverse plane. Solutions are presented for some first-order and second-order design problems

  3. Circular polarization sensitive absorbers based on graphene

    Science.gov (United States)

    Yang, Kunpeng; Wang, Min; Pu, Mingbo; Wu, Xiaoyu; Gao, Hui; Hu, Chenggang; Luo, Xiangang

    2016-01-01

    It is well known that the polarization of a linearly polarized (LP) light would rotate after passing through a single layer graphene under the bias of a perpendicular magnetostatic field. Here we show that a corresponding phase shift could be expected for circularly polarized (CP) light, which can be engineered to design the circular polarization sensitive devices. We theoretically validate that an ultrathin graphene-based absorber with the thickness about λ/76 can be obtained, which shows efficient absorption >90% within incident angles of ±80°. The angle-independent phase shift produced by the graphene is responsible for the nearly omnidirectional absorber. Furthermore, a broadband absorber in frequencies ranging from 2.343 to 5.885 THz with absorption over 90% is designed by engineering the dispersion of graphene. PMID:27034257

  4. Plasmon-mediated circularly polarized luminescence of GaAs in a scanning tunneling microscope

    International Nuclear Information System (INIS)

    The electroluminescence from p-type GaAs(110) in a scanning tunneling microscope has been investigated at 6 K. Unexpectedly, high degrees of circular polarization have often been observed with ferromagnetic Ni tips and also with paramagnetic W and Ag tips. The data are interpreted in terms of two distinct excitation mechanisms. Electron injection generates intense luminescence with low polarization. Plasmon-mediated generation of electron-hole pairs leads to less intense emission, which, however, is highly polarized for many tips

  5. Plasmon-mediated circularly polarized luminescence of GaAs in a scanning tunneling microscope

    Energy Technology Data Exchange (ETDEWEB)

    Mühlenberend, Svenja; Gruyters, Markus; Berndt, Richard, E-mail: berndt@physik.uni-kiel.de [Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel (Germany)

    2015-12-14

    The electroluminescence from p-type GaAs(110) in a scanning tunneling microscope has been investigated at 6 K. Unexpectedly, high degrees of circular polarization have often been observed with ferromagnetic Ni tips and also with paramagnetic W and Ag tips. The data are interpreted in terms of two distinct excitation mechanisms. Electron injection generates intense luminescence with low polarization. Plasmon-mediated generation of electron-hole pairs leads to less intense emission, which, however, is highly polarized for many tips.

  6. Tangent hyperbolic circular frequency diverse array radars

    OpenAIRE

    Sarah Saeed; Ijaz Mansoor Qureshi; Waseem Khan; Ayesha Salman

    2016-01-01

    Frequency diverse array (FDA) with uniform frequency offset (UFO) has been in spot light of research for past few years. Not much attention has been devoted to non-UFOs in FDA. This study investigates tangent hyperbolic (TH) function for frequency offset selection scheme in circular FDAs (CFDAs). Investigation reveals a three-dimensional single-maximum beampattern, which promises to enhance system detection capability and signal-to-interference plus noise ratio. Furthermore, by utilising the ...

  7. Resonant Laser Cooling of Circular Accelerator Beams

    OpenAIRE

    Tumanian, R. V.

    2004-01-01

    The resonant laser cooling of circular accelerator beams of relativistic charged particle is studied. It is shown that in the approximation of the given external electromagnetic wave amplitude (small gain free electron laser) the emittance of a beam of charged particles decreases. In the field of particle energy about 100 in the mass energy units the beam energy losses are negligible. The discovered effect can be used for cooling of charged particle beams in various accelerators. The signific...

  8. Circular Proteins from Plants and Fungi*

    OpenAIRE

    Göransson, Ulf; Burman, Robert; Gunasekera, Sunithi; Strömstedt, Adam A.; Rosengren, K. Johan

    2012-01-01

    Circular proteins, defined as head-to-tail cyclized polypeptides originating from ribosomal synthesis, represent a novel class of natural products attracting increasing interest. From a scientific point of view, these compounds raise questions of where and why they occur in nature and how they are formed. From a rational point of view, these proteins and their structural concept may be exploited for crop protection and novel pharmaceuticals. Here, we review the current knowledge of three prot...

  9. SEAMLESS TECHNOLOGY ON CIRCULAR KNITTING MACHINES

    OpenAIRE

    CRETU Viorica

    2014-01-01

    With industrial progress, the advancements in garment manufacturing have evolved from cut & sew to complete garment knitting, which produces one entire garment without sewing or linking process. Seamless knitting technology is similar to sock manufacture, the specialized circular knitting machines producing 3 dimensional garments with no side seams, with the waistband integrated with body of the garment and with knitted washing instructions and logos. The paper starts by presenting the main a...

  10. FROM CIRCULAR ECONOMY TO BLUE ECONOMY

    OpenAIRE

    Iustin-Emanuel, ALEXANDRU; Alexandru, TASNADI

    2014-01-01

    Addressing the subject of this essay is based on the background ideas generated by a new branch of science - Biomimicry. According to European Commissioner for the Environment, "Nature is the perfect model of circular economy". Therefore, by imitating nature, we are witnessing a process of cycle redesign: production-consumption-recycling. The authors present some reflections on the European Commission's decision to adopt after July 1, 2014 new measures concerning the development of more circu...

  11. Circular symmetrization of condensers on Riemann surfaces

    Science.gov (United States)

    Dubinin, V. N.

    2015-01-01

    We give a simplified definition of the new version of circular symmetrization which has previously been suggested by the author for solving extremal problems in geometric function theory. A proof of the symmetrization principle for the capacities of condensers on Riemann surfaces is presented. In addition, the class of condensers under consideration is extended and all the cases of equality in the symmetrization principle are found. Bibliography: 22 titles.

  12. Gravitational collapse of a circularly symmetric star

    OpenAIRE

    Sharma, Ranjan; Das, Shyam; Rahaman, Farook; Shit, Gopal Chandra

    2015-01-01

    We investigate the collapse of a circularly symmetric star with outgoing radiation in ($2+1$)-dimensional anti-de Sitter spacetime. The exterior spacetime of the collapsing star is assumed to be described by the non-static generalization of the Ba\\~nados, Teitelboim and Zanelli [{\\em Phys. Rev. Lett.} {\\bf 69} (1992) 1849 ] metric. Making use of the junction conditions joining smoothly the interior and the exterior spacetimes across the boundary, we analyze the impacts of various factors on t...

  13. Introduction to transfer lines and circular machines

    International Nuclear Information System (INIS)

    This course was given in the 1983-84 Academic Training Programme. It is designed as an elementary introduction to both the theory and the hardware for transfer lines and circular machines. The course is limited to linear problems and treates the topics of single particle motion in the transverse and longitudinal planes, emittance ellipses, parameterisation, optical properties of some specific modules, stabilities in the transverse and longitudinal planes, field and gradient errors, and scattering in thin windows. (orig.)

  14. Circular Modes for Flat Beams in LHC

    CERN Document Server

    Burov, A

    2013-01-01

    Typically x/y optical coupling is considered as unwanted and thus suppressed--particular exclusions are electron and ionization coolers. Could some special coupled modes be effectively applied for the LHC complex? Apparently, the answer is positive: use of the circular modes in the injectors with their transformation into planar modes in the LHC allows both the space charge and beam-beam luminosity limitations to be significantly reduced, if not practically eliminated.

  15. Drops with non-circular footprints

    OpenAIRE

    Ravazzoli, Pablo D.; González, Alejandro G.; Diez, Javier A.

    2015-01-01

    In this paper we study the morphology of drops formed on partially wetting substrates, whose footprint is not circular. This type of drops is a consequence of the breakup processes occurring in thin films when anisotropic contact line motions take place. The anisotropy is basically due to hysteresis effects of the contact angle since some parts of the contact line are wetting, while others are dewetting. Here, we obtain a peculiar drop shape from the rupture of a long liquid filament sitting ...

  16. Broadband circularly polarized antennas for UHF SATCOM

    OpenAIRE

    Tekin, İbrahim; Tekin, Ibrahim; Manzhura, Oksana; Niver, Edip

    2011-01-01

    Novel circularly polarized (CP) antenna configurations derived from Moxon type antenna (bent dipole element over a ground plane) for broadband VHF SATCOM applications. A sequence of topologies starting from a single vertical element to two vertical elements of the Moxon arms, then widened strip arm elements were studied. Further, arms were widened to bow tie structures with bents at 900.for achieving broadband operation. Bow tie elements were further split and optimized at a certain angle to...

  17. Covalently closed circular deoxyribonucleic acids in spiroplasmas.

    OpenAIRE

    Ranhand, J M; Mitchell, W. O.; Popkin, T J; Cole, R. M.

    1980-01-01

    Ten of twelve spiroplasma strains from different sources carried multiple covalently closed circular duplex deoxyribonucleic acid molecules, as shown by ethidium bromide-cesium chloride gradient centrifugation of cell lysates and examination of resulting bands by electron microscopy and agarose gel electrophoresis. Two to eight size classes per strain, comprising molecules of masses from 1 X 10(6) to 26 X 10(6), were detected. Several size classes of molecules were found in common in differen...

  18. FROM CIRCULAR ECONOMY TO BLUE ECONOMY

    Directory of Open Access Journals (Sweden)

    Iustin-Emanuel, ALEXANDRU

    2014-11-01

    Full Text Available Addressing the subject of this essay is based on the background ideas generated by a new branch of science - Biomimicry. According to European Commissioner for the Environment, "Nature is the perfect model of circular economy". Therefore, by imitating nature, we are witnessing a process of cycle redesign: production-consumption-recycling. The authors present some reflections on the European Commission's decision to adopt after July 1, 2014 new measures concerning the development of more circular economies. Starting from the principles of Ecolonomy, which is based on the whole living paradigm, this paper argues for the development within each economy of entrepreneurial policies related to the Blue economy. In its turn, Blue economy is based on scientific analyses that identify the best solutions in a business. Thus, formation of social capital will lead to healthier and cheaper products, which will stimulate entrepreneurship. Blue economy is another way of thinking economic practice and is a new model of business design. It is a healthy, sustainable business, designed for people. In fact, it is the core of the whole living paradigm through which, towards 2020, circular economy will grow more and more.

  19. Continuous-wave circular polarization terahertz imaging

    Science.gov (United States)

    Martin, Jillian P.; Joseph, Cecil S.; Giles, Robert H.

    2016-07-01

    Biomedical applications of terahertz (THz) radiation are appealing because THz radiation is nonionizing and has the demonstrated ability to detect intrinsic contrasts between cancerous and normal tissue. A linear polarization-sensitive detection technique for tumor margin delineation has already been demonstrated; however, utilization of a circular polarization-sensitive detection technique has yet to be explored at THz frequencies. A reflective, continuous-wave THz imaging system capable of illuminating a target sample at 584 GHz with either linearly or circularly polarized radiation, and capable of collecting both cross- and copolarized signals remitted from the target, is implemented. To demonstrate the system's utility, a fresh ex vivo human skin tissue specimen containing nonmelanoma skin cancer was imaged. Both polarization-sensitive detection techniques showed contrast between tumor and normal skin tissue, although some differences in images were observed between the two techniques. Our results indicate that further investigation is required to explain the contrast mechanism, as well as to quantify the specificity and sensitivity of the circular polarization-sensitive detection technique.

  20. Pulsed Accretion onto Eccentric and Circular Binaries

    CERN Document Server

    Muñoz, Diego J

    2016-01-01

    We present numerical simulations of circumbinary accretion onto eccentric and circular binaries using the moving-mesh code AREPO. This is the first set of simulations to tackle the problem of binary accretion using a finite-volume scheme on a freely moving mesh, which allows for accurate measurements of accretion onto individual stars for arbitrary binary eccentricity. While accretion onto a circular binary shows bursts with period of ~5 times the binary period P_b,accretion onto an eccentric binary is predominantly modulated at the period ~1P_b. For an equal-mass circular binary, the accretion rates onto individual stars are quite similar to each other, following the same variable pattern in time. By contrast, for eccentric binaries, one of the stars can accrete at a rate 10-20 times larger than its companion. This "symmetry breaking" between the stars, however, alternates over timescales of order 200 P_b, and can be attributed to a slowly precessing, eccentric circumbinary disk. Over longer timescales, the ...

  1. Application of circular polarized synchrotron radiation

    International Nuclear Information System (INIS)

    The idea of using the polarizing property of light for physical experiment by controlling it variously has been known from old time, and the Faraday effect and the research by polarizing microscopy are its examples. The light emitted from the electron orbit of an accelerator has the different polarizing characteristics from those of the light of a laboratory light source, and as far as observing it within the electron orbit plane, it becomes linearly polarized light. By utilizing this property well, research is carried out at present in synchrotron experimental facilities. Recently, the technology related to the insert type light cources using permanent magnets has advanced remarkably, and circular polarized light has become to be producible. If the light like this can be obtained with the energy not only in far ultraviolet region but also to x-ray region at high luminance, new possibility should open. At the stage that the design of an insert type light source was finished, and its manufacture was started, the research on the method of evaluating the degree of circular polarization and the research on the utilization of circular polarized synchrotron radiation are earnestly carried out. In this report, the results of researches presented at the study meeting are summarized. Moreover, the design and manufacture of the beam lines for exclusive use will be carried out. (Kako, I.)

  2. Online inspection of circular fluorescent lamp

    Science.gov (United States)

    Ang, Beng-Hoe

    1998-10-01

    One step in the manufacture of circular fluorescent lamps is the mercury (Hg) injection process in which a small amount of mercury approximately 20 mg is injected into the fluorescent tube. An on-line detection of mercury is required to ensure that the amount of mercury residual inside the tube is within the acceptable tolerance. This critical operation is to reduce manufacturing overhead by controlling cost and reducing waste of materials. In view of this, an attempt has been made to design and develop an on- line mercury detection system with important benefits to the manufacturers, such as increased throughput, accuracy, reliability and consistency. This paper presents the configuration and development works of the on-line circular fluorescent lamp inspection system developed by Industrial Project Group--Machine Vision Center of Nanyang Polytechnic. The inspection system performs on-line detection of mercury particles (Hg) inside the circular fluorescent lamp. Taking the orientation and translation offsets of the lamp into consideration, it detects the presence/absence as well as the size of the injected mercury. The system has been successfully operating 15 hours per day and inspecting more than 22 thousands lamps in the production plant.

  3. Intense low energy positron beams

    Energy Technology Data Exchange (ETDEWEB)

    Lynn, K.G.; Jacobsen, F.M.

    1993-12-31

    Intense positron beams are under development or being considered at several laboratories. Already today a few accelerator based high intensity, low brightness e{sup +} beams exist producing of the order of 10{sup 8} {minus} 10{sup 9} e{sup +}/sec. Several laboratories are aiming at high intensity, high brightness e{sup +} beams with intensities greater than 10{sup 9} e{sup +}/sec and current densities of the order of 10{sup 13} {minus} 10{sup 14} e{sup +} sec{sup {minus}} {sup 1}cm{sup {minus}2}. Intense e{sup +} beams can be realized in two ways (or in a combination thereof) either through a development of more efficient B{sup +} moderators or by increasing the available activity of B{sup +} particles. In this review we shall mainly concentrate on the latter approach. In atomic physics the main trust for these developments is to be able to measure differential and high energy cross-sections in e{sup +} collisions with atoms and molecules. Within solid state physics high intensity, high brightness e{sup +} beams are in demand in areas such as the re-emission e{sup +} microscope, two dimensional angular correlation of annihilation radiation, low energy e{sup +} diffraction and other fields. Intense e{sup +} beams are also important for the development of positronium beams, as well as exotic experiments such as Bose condensation and Ps liquid studies.

  4. Architectural Surfaces and Structures from Circular Arcs

    KAUST Repository

    Shi, Ling

    2013-12-01

    In recent decades, the popularity of freeform shapes in contemporary architecture poses new challenges to digital design. One of them is the process of rationalization, i.e. to make freeform skins or structures affordable to manufacture, which draws the most attention from geometry researchers. In this thesis, we aim to realize this process with simple geometric primitives, circular arcs. We investigate architectural surfaces and structures consisting of circular arcs. Our focus is lying on how to employ them nicely and repetitively in architectural design, in order to decrease the cost in manufacturing. Firstly, we study Darboux cyclides, which are algebraic surfaces of order ≤ 4. We provide a computational tool to identify all families of circles on a given cyclide based on the spherical model of M ̈obius geometry. Practical ways to design cyclide patches that pass through certain inputs are presented. In particular, certain triples of circle families on Darboux cyclides may be suitably arranged as 3-webs. We provide a complete classification of all possible 3-webs of circles on Darboux cyclides. We then investigate the circular arc snakes, which are smooth sequences of circu- lar arcs. We evolve the snakes such that their curvature, as a function of arc length, remains unchanged. The evolution of snakes is utilized to approximate given surfaces by circular arcs or to generated freeform shapes, and it is realized by a 2-step pro- cess. More interestingly, certain 6-arc snake with boundary constraints can produce a smooth self motion, which can be employed to build flexible structures. Another challenging topic is approximating smooth freeform skins with simple panels. We contribute to this problem area by approximating a negatively-curved 5 surface with a smooth union of rational bilinear patches. We provide a proof for vertex consistency of hyperbolic nets using the CAGD approach of the rational B ́ezier form. Moreover, we use Darboux transformations for the

  5. Background, Pattern and Policy of China for Developing Circular Economy

    Institute of Scientific and Technical Information of China (English)

    Zhu Dajian

    2008-01-01

    Circular economy has become one of China's important strategies to realize scientific development and build ecological civilization at present. As in China circular economy was put forward as a new economic pattern, the international community generally holds that this is an innovative move for China's economy to realize leap-forward development and hopes to learn more about the theory, policy and practice relating to China's circular economy. This article introduces and comments on the necessity to develop circular economy in China, implications and characteristics of China's circular economy, and China's main practices and policies to promote it at present.

  6. Experimental verification of the Keldysh approximation for circularly polarized light

    International Nuclear Information System (INIS)

    Full text: Several nonperturbative approaches have been developed in past decades to describe ionization of an atomic system in a strong laser field. One of them, the Keldysh-Faisal-Reiss (KFR) theory, treats the problem analytically. The KFR theory however is based on the assumption of a short range binding potential. This is obviously not fulfilled in atoms due to the long range Coulomb interaction of the electron with the atomic core. In negative ions on the other hand this problem does not appear. It makes negative ions an ideal atomic system for verification of Keldysh-like theories. In our previous experiments on F- we have shown that the angle resolved spectrum of electrons detached in a linear polarized laser field is well reproduced by a Keldysh-like theory by Gribakin and Kuchiev. In particular we observed the predicted quantum interference effect. The question whether or not such an interference effect would also be present in the case of a circularly polarized light is addressed here experimentally. In our experiment negatively charged fluorine ions are exposed to a strong circularly polarized infrared laser pulse of approximately 120 fs duration and a peak intensity on the order of 1013 W/cm2. The photodetached electrons are projected onto a 2D position sensitive detector lying in a plane parallel to the laser propagation axis. The cylindrical symmetry in the electron angular distribution is then used to recover the full 3D distribution by a back projection algorithm, yielding the angle resolved energy distribution of the photodetached electrons. In contrast to our previous experiments using linear polarized light, the spectrum does not exhibit any structure that can be associated with the quantum interference effect. This is in agreement with our recent predictions. Comparison of our experimental data with predictions using the length and velocity gauges will be discussed. Refs. 3 (author)

  7. Beam Induced Hydrodynamic Tunneling in the Future Circular Collider Components

    Science.gov (United States)

    Tahir, N. A.; Burkart, F.; Schmidt, R.; Shutov, A.; Wollmann, D.; Piriz, A. R.

    2016-08-01

    A future circular collider (FCC) has been proposed as a post-Large Hadron Collider accelerator, to explore particle physics in unprecedented energy ranges. The FCC is a circular collider in a tunnel with a circumference of 80-100 km. The FCC study puts an emphasis on proton-proton high-energy and electron-positron high-intensity frontier machines. A proton-electron interaction scenario is also examined. According to the nominal FCC parameters, each of the 50 TeV proton beams will carry an amount of 8.5 GJ energy that is equivalent to the kinetic energy of an Airbus A380 (560 t) at a typical speed of 850 km /h . Safety of operation with such extremely energetic beams is an important issue, as off-nominal beam loss can cause serious damage to the accelerator and detector components with a severe impact on the accelerator environment. In order to estimate the consequences of an accident with the full beam accidently deflected into equipment, we have carried out numerical simulations of interaction of a FCC beam with a solid copper target using an energy-deposition code (fluka) and a 2D hydrodynamic code (big2) iteratively. These simulations show that, although the penetration length of a single FCC proton and its shower in solid copper is about 1.5 m, the full FCC beam will penetrate up to about 350 m into the target because of the "hydrodynamic tunneling." These simulations also show that a significant part of the target is converted into high-energy-density matter. We also discuss this interesting aspect of this study.

  8. Unsteady flow around two-dimensional circular cylinder bundles in fluid elastic vibration

    International Nuclear Information System (INIS)

    We describe the unsteady flow around two-dimensional circular cylinder bundles supported by the leaf spring in the fluid-elastic vibration. The experiment was carried out in a circuit-type wind tunnel having a 200 mm x 200 mm working section of 2,000 mm length at the Reynolds number Re of 6,300. Two-dimensional circular cylinders with diameter D = 20 mm were aligned at regular spaces S in the square array of three rows. The spacing ratio between two adjoining circular cylinders was constant as S/D = 1.5. The time-mean velocity, turbulent intensities and Reynolds stress were measured by use of a laser Doppler velocimeter. The unsteady flow pattern around an oscillating cylinder was observed by the flow visualization in a water channel. Consequently, it was found that the occurrence of the fluid-elastic vibration is caused by the phenomenon of wake-switch for the circular cylinder bundles of three rows. (author)

  9. Flow Characteristics of a Liquid Crystal Mixture in a Circular Pipe Electrode

    Science.gov (United States)

    Tsukiji, Tetsuhiro; Koyabu, Eitaro

    A circular pipe electrode was developed to control the pressure and the flow rate of the ER(Electro-rheological) fluids by one of the authors. The shape of the electrode is a circular pipe and some parts of the inner surface of the pipe are the electrode. The diameter of the tube is 1mm and the four pairs of the electrode are used. In the present study a liquid crystal mixture is selected for a homogeneous ER fluid and the pressure drop of the circular pipe electrode is measured for the constant flow rates under application of the voltages. The voltages are added in the peripheral direction. The director which is the average direction of the molecular of the liquid crystal is perpendicular to the flow direction. On the other hands, numerical analysis of the electric fields and the flow in the circular pipe electrode is conducted and the relations between the flow rate and the pressure are obtained for various electric field intensities, which almost agree with experimental results. The emphasized point of the present flow analysis is assuming that the viscosity of a liquid crystal mixture distributes in the flow field. Furthermore the pulse-wave voltages are added to the electrodes to control the pressure drop using the pulse width modulation. It is found that the pressure can be controlled using the pulse width modulation in the some range of the parameters.

  10. Development of database on circular abandoned channel in Japan

    International Nuclear Information System (INIS)

    To develop a method for estimating late Quaternary uplift rates of inland mountainous terrains where fluvial terraces are poorly developed, we focused on 'circular abandoned channels', formed by meander cut-offs or river capture of an incised meandering river. We studied about 1,000 circular abandoned channels distributed throughout the Islands of Japan, and developed GIS database on circular abandoned channel in Japan. This database contains formation process, relative heights, degree of dissection and bedrocks of circular abandoned channels. Circular abandoned channels are distributed in inland mountainous terrains, where late Quaternary uplift rates are unknown, and indicate different relative heights along the same river. Relative heights tend to correlate with degree of dissection of the circular abandoned channels, which may indicate that degree of dissection correlate with ages of abandonment of circular abandoned channels. A CD-ROM is attached as an appendix. (J.P.N.)

  11. Propagation and radiation characteristics of the circular electric, circular magnetic and hybrid waveguide modes

    International Nuclear Information System (INIS)

    The field distributions and propagation constants of the circular electric, circular magnetic and hybrid modes of oversized waveguides are expressed, taking the effects of walls into account. The near and far field patterns are derived in the case of real wall functions. It is shown that, for very oversized waveguides, the terms containing wall functions can be ignored in the calculations, and it results that the expressions of fields and propagation constants become independent of the types of waveguides. An application to corrugated waveguides for Electron Cyclotron Resonance Heating experiments shows the variations of the radiation characteristics versus geometric parameters of the corrugations and determines the ranges of interest for these parameters. (author)

  12. Controlling electron-ion rescattering in two-color circularly polarized femtosecond laser fields

    Science.gov (United States)

    Mancuso, Christopher A.; Hickstein, Daniel D.; Dorney, Kevin M.; Ellis, Jennifer L.; Hasović, Elvedin; Knut, Ronny; Grychtol, Patrik; Gentry, Christian; Gopalakrishnan, Maithreyi; Zusin, Dmitriy; Dollar, Franklin J.; Tong, Xiao-Min; Milošević, Dejan B.; Becker, Wilhelm; Kapteyn, Henry C.; Murnane, Margaret M.

    2016-05-01

    High-harmonic generation driven by two-color counter-rotating circularly polarized laser fields was recently demonstrated experimentally as a breakthrough source of bright, coherent, circularly polarized beams in the extreme ultraviolet and soft-x-ray regions. However, the conditions for optimizing the single-atom yield are significantly more complex than for linearly polarized driving lasers and are not fully understood. Here we present a comprehensive study of strong-field ionization—the complementary process to high-harmonic generation—driven by two-color circularly polarized fields. We uncover the conditions that lead to enhanced electron-ion rescattering, which should correspond to the highest single-atom harmonic flux. Using a velocity map imaging photoelectron spectrometer and tomographic reconstruction techniques, we record three-dimensional photoelectron distributions resulting from the strong-field ionization of argon atoms across a broad range of driving laser intensity ratios. In combination with analytical predictions and advanced numerical simulations, we show that "hard" electron-ion rescattering is optimized when the second-harmonic field has an intensity approximately four times higher than that of the fundamental driving field. We also investigate electron-ion rescattering with co-rotating fields, and find that rescattering is significantly suppressed when compared with counter-rotating fields.

  13. Multipole Analysis of Circular Cylindircal Magnetic Systems

    Energy Technology Data Exchange (ETDEWEB)

    J Selvaggi

    2006-01-09

    This thesis deals with an alternate method for computing the external magnetic field from a circular cylindrical magnetic source. The primary objective is to characterize the magnetic source in terms of its equivalent multipole distribution. This multipole distribution must be valid at points close to the cylindrical source and a spherical multipole expansion is ill-equipped to handle this problem; therefore a new method must be introduced. This method, based upon the free-space Green's function in cylindrical coordinates, is developed as an alternative to the more familiar spherical harmonic expansion. A family of special functions, called the toroidal functions or Q-functions, are found to exhibit the necessary properties for analyzing circular cylindrical geometries. In particular, the toroidal function of zeroth order, which comes from the integral formulation of the free-space Green's function in cylindrical coordinates, is employed to handle magnetic sources which exhibit circular cylindrical symmetry. The toroidal functions, also called Q-functions, are the weighting coefficients in a ''Fourier series-like'' expansion which represents the free-space Green's function. It is also called a toroidal expansion. This expansion can be directly employed in electrostatic, magnetostatic, and electrodynamic problems which exhibit cylindrical symmetry. Also, it is shown that they can be used as an alternative to the Elliptic integral formulation. In fact, anywhere that an Elliptic integral appears, one can replace it with its corresponding Q-function representation. A number of problems, using the toroidal expansion formulation, are analyzed and compared to existing known methods in order to validate the results. Also, the equivalent multipole distribution is found for most of the solved problems along with its corresponding physical interpretation. The main application is to characterize the external magnetic field due to a six

  14. MHD stability of an almost circular tokamak

    International Nuclear Information System (INIS)

    In a tokamak, the ratio β between the plasma pressure and that of the magnetic field is limited by the appearance of instabilities. The magnetic field in a tokamak reactor will always be limited by technological constraints. It is therefore crucial to know what factors have an effect on the β limit, since a zero resistivity plasma fluid model allows for theoretical reproduction of the β limits observed experimentally. Theoretical studies have shown that the distributions of pressure and current density may have a substantial effect on the β limit. The effect of the current density and pressure distributions on the β limit has been studied for tokamak with a circular core section. The best results are obtained when the current density is concentrated in the centre of the section and is nil at the periphery. But the second region of stability against ballooning modes cannot be obtained in a circular tokamak owing to the destabilisation of the universal modes. This study was then extended to the stability of plasmas the section of which is almost circular and has a point of reflection. Such configurations are vital for fusion since they allow systems in which the confinement time does not deteriorate with an increase in the additional heating power. The β limit was calculated for different positions of the reflection point. The results show that when it is displaced from the interior towards the exterior of the torus, the stability of the overall modes is progressively improved until it is vertical. But if the point of reflection is further displaced from this vertical position towards the exterior of the torus, localised modes close to the edge of the plasma are destabilised and bring about a drop in the β limit. (author) figs., tabs., 80 refs

  15. Porphyrin Protonation Studied by Magnetic Circular Dichroism

    Czech Academy of Sciences Publication Activity Database

    Štěpánek, Petr; Andrushchenko, Valery; Ruud, K.; Bouř, Petr

    2012-01-01

    Roč. 116, č. 1 (2012), s. 778-783. ISSN 1089-5639 R&D Projects: GA ČR GAP208/11/0105; GA ČR GA203/09/2037; GA ČR GAP208/10/0559; GA MŠk(CZ) LH11033 Institutional research plan: CEZ:AV0Z40550506 Keywords : magnetic circular dichroism (MCD) * TPPS * spectra simulations * porphyrin protonation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.771, year: 2012

  16. The radiating part of circular sources

    OpenAIRE

    Carley, Michael

    2010-01-01

    An analysis is developed linking the form of the sound field from a circular source to the radial structure of the source, without recourse to far-field or other approximations. It is found that the information radiated into the field is limited, with the limit fixed by the wavenumber of source multiplied by the source radius (Helmholtz number). The acoustic field is found in terms of the elementary fields generated by a set of line sources whose form is given by Chebyshev polynomials of the ...

  17. Wideband Circularly Polarized Dielectric Rod Antenna

    OpenAIRE

    Min Guo; Ji-Jun Yan; Shun-Shi Zhong; Zhu Sun

    2012-01-01

    A new dielectric rod antenna (DRA) is introduced to produce circular polarization (CP) over a wide frequency band without a complex feed network. Along with the simulated results, measured results of the antenna prototype are presented, showing a 3 dB axial ratio (AR) CP bandwidth of 17.7%. The radiation characteristics of the fabricated antenna are also demonstrated showing the measured gain of better than 6.2 dBi. Moreover, the measured impedance bandwidth (VSWR ≤2) reaches 20.1%, from 8.75...

  18. Build a circularly polarized waveguide slot antenna

    Science.gov (United States)

    Kisliuk, M.; Axelrod, A.

    1987-06-01

    The development and design of a circularly polarized waveguide slot antenna are described. Consideration is given to the resonance frequency, radiation efficiencies, excitement, and resonant conductance of the transverse and longitudinal slots. The transverse and longitudinal slots in a rectangular guide are analyzed. The voltage distribution across the slot is calculated from the solution of a standard transmission line equation; and using the Poynting theorem the fields scattered by the slot in an arbitrary frequency range are determined. The proposed antenna is examined using an equivalent circuit; a diagram of the circuit is given. The radiation, slot, and antenna efficiencies are measured.

  19. Denaturation of circular DNA: Supercoils and overtwist

    OpenAIRE

    Kabakçıoğlu, Alkan; Bar, Amir ; Mukamel, David

    2012-01-01

    PHYSICAL REVIEW E 86, 061904 (2012) Denaturation of circular DNA: Supercoils and overtwist Amir Bar,1,2 Alkan Kabakc¸ıo˘glu,3 and David Mukamel1 1Department of Physics of Complex Systems, The Weizmann Institute of Science, Rehovot 76100, Israel 2Department of Computer Science and Applied Mathematics, The Weizmann Institute of Science, Rehovot 76100, Israel 3Department of Physics, Koc¸ University, Sarıyer 34450 ˙Istanbul, Turkey (Received 30 July 2012; published 11 December 2...

  20. Nonuniform micromagnetic states in thin circular dots

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Z.-H. E-mail: zhwei@phys.ntu.edu.tw; Lai, M.-F.; Chang, C.-R.; Usov, N.A.; Wu, J.C.; Lai, J.-Y

    2004-11-01

    Micromagnetic states are strongly related to sizes of nano-dots. The quasiuniform state becomes unstable and transforms to a new nonuniform state as the diameter of the permalloy circular dot exceeds some critical size. The magnetization curvature increases gradually as the diameter increases. Finally, when the diameter is larger than another critical size, the new nonuniform state becomes unstable and a vortex enters the particle. Hence the new nonuniform state plays an intermediate role in the evolution from the quasiuniform state to the vortex state as the diameter increases.

  1. Circular orbits on a warped spandex fabric

    CERN Document Server

    Middleton, Chad A

    2013-01-01

    We present a theoretical and experimental analysis of circular-like orbits made by a marble rolling on a warped spandex fabric. We show that the mass of the fabric interior to the orbital path influences the motion of the marble in a nontrivial way, and can even dominate the orbital characteristics. We also compare a Kepler-like expression for such orbits to similar expressions for orbits about a spherically-symmetric massive object in the presence of a constant vacuum energy, as described by general relativity.

  2. Polarized triplet production by circularly polarized photons

    CERN Document Server

    Bytev, V V; Galynsky, M V; Potylitsin, A P

    2002-01-01

    A process of the pair production by a circularly polarized photon in the field of unpolarized atomic electron has been considered in the Weizaecker-Williams approximation. The degree of longitudinal polarization of positron and electron has been calculated. An exclusive cross-section as well as a spectral distribution are obtained. We estimate the accuracy of our calculations at the level of a few percent. We show the identity of the positron polarization for considered process and for process of pair production in the screened Coulomb field of nucleus.

  3. Nonlinear traveling wave vibration of a circular cylindrical shell subjected to a moving concentrated harmonic force

    Science.gov (United States)

    Wang, Y. Q.; Guo, X. H.; Li, Y. G.; Li, J.

    2010-03-01

    This is a study of nonlinear traveling wave response of a cantilever circular cylindrical shell subjected to a concentrated harmonic force moving in a concentric circular path at a constant velocity. Donnell's shallow-shell theory is used, so that moderately large vibrations are analyzed. The problem is reduced to a system of ordinary differential equations by means of the Galerkin method. Frequency-responses for six different mode expansions are studied and compared with that for single mode to find the more contracted and accurate mode expansion investigating traveling wave vibration. The method of harmonic balance is applied to study the nonlinear dynamic response in forced oscillations of this system. Results obtained with analytical method are compared with numerical simulation, and the agreement between them bespeaks the validity of the method developed in this paper. The stability of the period solutions is also examined in detail.

  4. Circular Permutation of a Chaperonin Protein: Biophysics and Application to Nanotechnology

    Science.gov (United States)

    Paavola, Chad; Chan, Suzanne; Li, Yi-Fen; McMillan, R. Andrew; Trent, Jonathan

    2004-01-01

    We have designed five circular permutants of a chaperonin protein derived from the hyperthermophilic organism Sulfolobus shibatae. These permuted proteins were expressed in E. coli and are well-folded. Furthermore, all the permutants assemble into 18-mer double rings of the same form as the wild-type protein. We characterized the thermodynamics of folding for each permutant by both guanidine denaturation and differential scanning calorimetry. We also examined the assembly of chaperonin rings into higher order structures that may be used as nanoscale templates. The results show that circular permutation can be used to tune the thermodynamic properties of a protein template as well as facilitating the fusion of peptides, binding proteins or enzymes onto nanostructured templates.

  5. Dynamic stability of viscoelastic circular cylindrical shells taking into account shear deformation and rotatory inertia

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The present work discusses the problem of dynamic stability of a viscoelastic circular cylindrical shell, according to revised Timoshenko theory, with an account of shear deformation and rotatory inertia in the geometrically nonlinear statement. Proceeding by Bubnov-Galerkin method in combination with a numerical method based on the quadrature formula the problem is reduced to a solution of a system of nonlinear integro-differential equations with singular kernel of relaxation. For a wide range of variation of physical mechanical and geometrical parameters, the dynamic behavior of the shell is studied. The influence of viscoelastic properties of the material on the dynamical stability of the circular cylindrical shell is shown. Results obtained using different theories are compared.

  6. Estimating SI violation in CMB due to non-circular beam and complex scan in minutes

    CERN Document Server

    Pant, Nidhi; Rotti, Aditya; Mitra, Sanjit; Souradeep, Tarun

    2015-01-01

    Mild, unavoidable deviations from circular-symmetry of instrumental beams along with scan strategy can give rise to measurable Statistical Isotropy (SI) violation in Cosmic Microwave Background (CMB) experiments. If not accounted properly, this spurious signal can complicate the extraction of other SI violation signals (if any) in the data. However, estimation of this effect through exact numerical simulation is computationally intensive and time consuming. A generalized analytical formalism not only provides a quick way of estimating this signal, but also gives a detailed understanding connecting the leading beam anisotropy components to a measurable BipoSH characterisation of SI violation. In this paper, we provide an approximate generic analytical method for estimating the SI violation generated due to a non-circular (NC) beam and arbitrary scan strategy, in terms of the Bipolar Spherical Harmonic (BipoSH) spectra. Our analytical method can predict almost all the features introduced by a NC beam in a compl...

  7. Simple Broadband Circular Polarizer in Oversized Waveguide

    Science.gov (United States)

    Stange, Torsten

    2016-02-01

    In this paper, a possibility is shown to realize a simple waveguide polarizer producing nearly the same circular polarization over a broad frequency range up to an octave. It is based upon the combination of two smoothly squeezed oversized waveguides with different diameters. The principle is similar to an achromatic lens in optics, where two counteracting lenses with differently sloped wavelength dependencies of the refractive index are combined to compensate the dispersion in the desired wavelength range. Consequently, two different wavelengths of light are brought into focus at the same plane. A waveguide for the transmission of microwaves has a similar frequency dependence of the refractive index resulting in a frequency-dependent phase shift between two propagating waves polarized along the symmetry axes of a waveguide with an elliptical cross section. For this reason, an incident wave with a linear polarization between the axes of symmetry can be only converted into a circularly polarized wave over a limited frequency range. However, the diameter and the shape along two counteracting squeezed waveguides can be adjusted in such a way that the frequency dependence of the resultant phase shift is finally canceled out.

  8. High Performance Circularly Polarized Microstrip Antenna

    Science.gov (United States)

    Bondyopadhyay, Probir K. (Inventor)

    1997-01-01

    A microstrip antenna for radiating circularly polarized electromagnetic waves comprising a cluster array of at least four microstrip radiator elements, each of which is provided with dual orthogonal coplanar feeds in phase quadrature relation achieved by connection to an asymmetric T-junction power divider impedance notched at resonance. The dual fed circularly polarized reference element is positioned with its axis at a 45 deg angle with respect to the unit cell axis. The other three dual fed elements in the unit cell are positioned and fed with a coplanar feed structure with sequential rotation and phasing to enhance the axial ratio and impedance matching performance over a wide bandwidth. The centers of the radiator elements are disposed at the corners of a square with each side of a length d in the range of 0.7 to 0.9 times the free space wavelength of the antenna radiation and the radiator elements reside in a square unit cell area of sides equal to 2d and thereby permit the array to be used as a phased array antenna for electronic scanning and is realizable in a high temperature superconducting thin film material for high efficiency.

  9. The Circular Velocity Function of Group Galaxies

    CERN Document Server

    Abramson, Louis E; Benson, Andrew J; Kollmeier, Juna A; Mulchaey, John S

    2013-01-01

    A robust prediction of LCDM cosmology is the halo circular velocity function (CVF), a dynamical cousin of the halo mass function. However, the correspondence between theoretical and observed CVFs is uncertain: cluster galaxies are reported to exhibit a power-law CVF consistent with N-body simulations, but that of the field is distinctly Schechter-like, flattened relative to LCDM expectations at circular velocities v_c < 200 km/s. Groups offer a powerful probe of the role of environment in this discrepancy as they bridge the field and clusters. Here, we construct the CVF for a large, mass- and multiplicity-complete sample of group galaxies from the Sloan Digital Sky Survey. Using independent photometric v_c estimators, we find no transition from field- to LCDM-shaped CVF above v_c = 50 km/s as a function of group halo mass. All groups with 12.4 < log(M_halo/M_sun) < 15.1 (Local Group analogs to rich clusters) display similar Schechter-like CVFs that are marginally suppressed at low-v_c compared to tha...

  10. Circular economy: from an institutional perspective

    Institute of Scientific and Technical Information of China (English)

    Lu Jingchao

    2007-01-01

    Circular economy (CE) has been put fonvard as an important environmental and resource strategy in China.Aiming at the high utilization rate of resources and reduction of pollutants,CE means to realize a shift of fundamental paradigm.With the mode of production and consumption from linear to recycling model,the promotion requires transdisciplinary researches which integrate technological,ecological,social-cultural and other sciences.The present study focuses on the implementation of circular economy from an institutional perspective.Institution acts as a crucial factor by providing incentives for technical innovation,leading investment orientation and determining policy effectiveness,etc.This paper mainly discusses about: firstly,the feature of institution,institutional changes and institutional innovation is articulated,together with eco-industrial park strategy,extended producer's responsibility and dematerialization principle as innovative institutional arrangements; secondly,as policy plays great role on institutional changing process,the mechanism of policy implementation is needed to be related; as a result,coevolution of institutions and policies is thus presented; at last,a pilot attempt is made to find out some operational avenues in accomplishment of CE through both theoretical and practical methodology,special resolutions are put forward after some projecting difficulties and dilemmas in China are described.

  11. Circular RNAs are abundant, conserved, and associated with ALU repeats

    OpenAIRE

    Jeck, William R.; Sorrentino, Jessica A.; Wang, Kai; Slevin, Michael K.; Christin E Burd; Liu, Jinze; Marzluff, William F.; Sharpless, Norman E.

    2013-01-01

    Using a novel approach to identify exonic circular RNAs (ecircRNAs), the authors show widespread production of circular RNAs from a significant fraction of expressed genes in murine and human cells. They demonstrate that several of these noncoding transcripts are stable and abundant and can be targeted by siRNA. Bioinformatic analysis of the entire ecircRNA complement revealed gene features associated with RNA circularization.

  12. Remodelling fashion via circular economy driven luxury concept

    OpenAIRE

    Kuivanen, Pyry

    2016-01-01

    The thesis aimed to research circular economy’s intangible value in the global textile industry. The focus targeted on investigating, how luxury could become a positive input to a circular economy driven brand. The goal was to find and understand different perceptions of business concepts, customers and brands in order to build a notion of circular economy driven luxury fashion brand identity. Brand identity study was conducted by analyzing brands’ identities key facets. Scrutinizing mult...

  13. Microstrip-fed Wideband Circularly Polarized Printed Antenna

    OpenAIRE

    Bao, Xiulong; Ammann, Max; McEvoy, Patrick

    2010-01-01

    A wideband circularly-polarized printed antenna is proposed, which employs an asymmetrical dipole and a slit in the ground plane which are fed by an L-shaped microstrip feedline using a via. The proposed antenna geometry is arranged so that the orthogonal surface currents, which are generated in the dipole, feedline and ground plane, have the appropriate phase to provide circular polarization. A parametric study of the key parameters is made and the mechanism for circular polarization is desc...

  14. High Performance Circularly Polarized Antenna Based on Fractal EBG Structure

    OpenAIRE

    Bao, Xiulong; Ammann, Max; Ruvio, Giuseppe; John, Matthias

    2006-01-01

    Circularly polarized patch antennas have been widely applied in wireless communication system, global positioning system, etc., because of their low-profile, lightweight, ease of fabrication and low lost [1,2]. To achieve high performance for circularly polarized patch antennas, some new structures were reported in the literature, such as antennas array, stack layer antennas, using periodic structures [3-7], etc. In this paper, a high performance circularly polarized low frequency patch anten...

  15. Two-Phase Flow in Circular Secondary Sedimentation Tanks

    OpenAIRE

    Matko, T. I. R.

    1997-01-01

    The main objective of this work was to optimise a numerical model to predict the flow in circular secondary sedimentation tanks. The numerical models in the literature were reviewed and the new opportunities for research were identified. Single-phase flow characteristics of two circular sedimentation tanks were investigated using the CFD program, CFX-F3D. The flow in the circular clarifiers were modelled in two dimensions (axial and radial) and using the standard k-E turbule...

  16. Analysis of FFAG accelerators and the evolution of circular accelerators

    International Nuclear Information System (INIS)

    After rapidly comparing circular machines with the linear accelerator and the reasons for the choice of an annular high energy and very high intensity accelerator, recent problems concerning accelerator theory are discussed, with emphasis on their physical character. The FFAG principle. The limit of the energy of FFAG cyclotron. The setting-up and interpreting of mean energy of focusing terms for a spiral FFAG synchrotron. The limiting amplitude stable near the non-linear resonance 2Qz = Qr, as well as the linear coupling resonance of Walkinshaw 2Qz = Qr. The crossed-beam accelerator. The 40 MeV electron model of MURA. Two other parts deal with linear and non-linear methods of injection and extraction using a variable disturbance applied to the magnetic field, as well as to collective effects. The interaction of the beam with the accelerating cavities and the walls. The modification of the phase oscillation equation. The influence of the beams' high frequency fields on the Nielsen longitudinal instability. (author)

  17. Higher order vortex gyrotropic modes in circular ferromagnetic nanodots.

    Science.gov (United States)

    Ding, Junjia; Kakazei, Gleb N; Liu, Xinming; Guslienko, Konstantin Y; Adeyeye, Adekunle O

    2014-01-01

    Magnetic vortex that consists of an in-plane curling magnetization configuration and a needle-like core region with out-of-plane magnetization is known to be the ground state of geometrically confined submicron soft magnetic elements. Here magnetodynamics of relatively thick (50-100 nm) circular Ni80Fe20 dots were probed by broadband ferromagnetic resonance in the absence of external magnetic field. Spin excitation modes related to the thickness dependent vortex core gyrotropic dynamics were detected experimentally in the gigahertz frequency range. Both analytical theory and micromagnetic simulations revealed that these exchange dominated modes are flexure oscillations of the vortex core string with n = 0,1,2 nodes along the dot thickness. The intensity of the mode with n = 1 depends significantly on both dot thickness and diameter and in some cases is higher than the one of the uniform mode with n = 0. This opens promising perspectives in the area of spin transfer torque oscillators. PMID:24762659

  18. Heparin-induced circular dichroism of an achiral, bicyclic species.

    Science.gov (United States)

    Stanley, Floyd E; Warner, Andrew M; McWilliams, Kayla M; Stalcup, Apryll M

    2011-01-01

    Antimalarial drugs have shown potential in suppressing the role of glycosaminoglycans (GAGs) in the pathology of prion protein conformational disorders (e.g. "Mad Cow" disease) by competing for sites of electrostatic interaction. In this study, circular dichroism (CD) and UV/Visible (UV/Vis) absorption spectroscopy techniques were used to investigate the interactions between N-methyl-N'-(7-chloro-4-quinolyl)-1,3-diaminopropane (QD), an achiral, bicyclic compound similar to previously investigated antimalarial drugs, and heparin, a complex GAG that is frequently used as a clinical anticoagulant. Relatively intense heparin-induced CD features were observed for QD and were noted to be radically different from previous studies using related chiral drugs, underscoring the importance of the Pfieffer effect on this and similar heparin research. Additionally, the induced CD for QD was observed to be highly dependent upon drug concentration, heparin concentration, system pH, equilibration time, and ionic strength. These results, in connection with recent work, provide new insight into the nature of the association between GAGs and antimalarial species. PMID:21125690

  19. Magnetism in the light of circular polarized x-rays

    International Nuclear Information System (INIS)

    Modern synchrotron X-ray sources providing highly intense X-rays of well-defined polarization led to the development of powerful techniques to get new insights into magnetic aspects of the electronic, crystallographic and geometric structure of solids. These methods are based on the X-ray magnetic circular dichroism (XMCD) resulting from the dependence of the X-ray absorption on the magnetization relative to the photon helicity. These effects which can be larger than 50 % occur at inner-shell absorption edges and reflect the spin and orbital polarization of the empty density of state allowing a quantitative determination of local magnetic spin and orbital moments with a high sensitivity up to 0.001 Bohr magnetons. The experimental aspects are outlined, a simple model for the origin of XMCD is presented and typical results are discussed. The unique possibility of using x-ray microscopy in combination with XMCD, which can combine lateral resolution of 15 nm and time resolution of 10 psec, is described and its potential to study magnetization dynamics in nanostructures demonstrated. (author)

  20. Velocity Profiles between Two Baffles in a Horizontal Circular Tube

    Institute of Scientific and Technical Information of China (English)

    Tae-Hyun Chang; Hae-Soo Lee; Keon-Je Oh; Doeg Hee Doh; Chang-Hoan Lee

    2014-01-01

    The shell and tube heat exchanger is an essential part of a power plant for recovering heat transfer between the feed water of a boiler and the wasted heat.The baffles are also an important element inside the heat exchanger.Internal materials influence the flow pattern in the bed.The influence of baffles in the velocity profiles was observed using a three-dimensional particle image velocimetry around baffles in a horizontal circular tube.The velocity of the particles was measured before the baffle and between them in the test tube.Results show that the flows near the front baffle flow were parallel to the vertical wall,and then concentrate on the upper opening of the front baffle.The flows circulate in the front and rear baffles.These flow profiles are related to the Reynolds number (Re) or the flow intensity.The velocity profiles at lower Re number showed a complicated mixing,concentrating on the lower opening of the rear baffle as front wall.Swirling flow was employed in this study,which was produced using tangential velocities at the inlet.At the entrance of the front baffle,the velocity vector profiles with swirl were much different from that without swirl.However,velocities between two baffles are not much different from those without swirl.

  1. Velocity profiles between two baffles in a horizontal circular tube

    Science.gov (United States)

    Chang, Tae-Hyun; Lee, Hae-Soo; Oh, Keon-Je; Doh, Doeg Hee; Lee, Chang-Hoan

    2014-12-01

    The shell and tube heat exchanger is an essential part of a power plant for recovering heat transfer between the feed water of a boiler and the wasted heat. The baffles are also an important element inside the heat exchanger. Internal materials influence the flow pattern in the bed. The influence of baffles in the velocity profiles was observed using a three-dimensional particle image velocimetry around baffles in a horizontal circular tube. The velocity of the particles was measured before the baffle and between them in the test tube. Results show that the flows near the front baffle flow were parallel to the vertical wall, and then concentrate on the upper opening of the front baffle. The flows circulate in the front and rear baffles. These flow profiles are related to the Reynolds number (Re) or the flow intensity. The velocity profiles at lower Re number showed a complicated mixing, concentrating on the lower opening of the rear baffle as front wall. Swirling flow was employed in this study, which was produced using tangential velocities at the inlet. At the entrance of the front baffle, the velocity vector profiles with swirl were much different from that without swirl. However, velocities between two baffles are not much different from those without swirl.

  2. The quantum spectra analysis of the circular billiards in wells

    Institute of Scientific and Technical Information of China (English)

    Zhang Yan-Hui; Zhang Li-Qin; Xu Xue-You; Ge Mei-Hua; Lin Sheng-Lu; Du Meng-Li

    2006-01-01

    We use a recently defined quantum spectral function and apply the method of closed-orbit theory to the 2D circular billiard system. The quantum spectra contain rich information of all classical orbits connecting two arbitrary points in the well. We study the correspondence between quantum spectra and classical orbits in the circular, 1/2 circular and 1/4 circular wells using the analytic and numerical methods. We find that the peak positions in the Fourier-transformed quantum spectra match accurately with the lengths of the classical orbits. These examples show evidently that semi-classical method provides a bridge between quantum and classical mechanics.

  3. Circularly Polarized Attosecond Pulses and Molecular Atto-Magnetism

    CERN Document Server

    Bandrauk, Andre D

    2014-01-01

    Various schemes are presented for the generation of circularly polarized molecular high-order harmonic generation (MHOHG) from molecules. In particular it is shown that combinations of counter-rotating circularly polarized pulses produce the lowest frequency Coriolis forces with the highest frequency recollisions, thus generating new harmonics which are the source of circular polarized attosecond pulses (CPAPs). These can be used to generate circularly polarized electronic currents in molecular media on attosecond time scale. Molecular attosecond currents allow then for the generation of ultrashort magnetic field pulses on the attosecond time scale, new tools for molecular atto-magnetism (MOLAM).

  4. Tunneling theory of H2 in presence of strong linear and circular polarized fields

    International Nuclear Information System (INIS)

    The ratio R of the angular ionization probabilities of H2 between parallel and perpendicular molecular orientations in a linear and a circular polarized fields using a molecular tunneling theory (MO-ADK) is studied. It is found that the ratio R for an H2 molecule in a strong field generally decreases with increases laser intensity, and the pattern of decrease depends on the duration of the laser pulse. A reasonable agreement with the experimental data is observed. These results invalidate the main result and corresponding statements in other works, where it is claimed that MO-ADK theory fails to predict the intensity-dependent anisotropy of H2. Furthermore, the effect of the focal-volume averaging on the anisotropy is studied. Finally, an extention of the MO-ADK model into the barrier-suppression regime is also given. A further improvement of the results at high intensities is found, if this correction is considered.

  5. Circular Orbits in the Taub-NUT and mass-less Taub-NUT Space-time

    CERN Document Server

    Pradhan, Parthapratim

    2016-01-01

    In this work we study the equatorial causal geodesics of the Taub-NUT(TN) space-time in comparison with \\emph{mass-less} TN space-time. We emphasized both on the null circular geodesics and time-like circular geodesics. From the effective potential diagram of null and time-like geodesics, we differentiate the geodesics structure between TN spacetime and mass-less TN space-time. It has been shown that there is a key role of the NUT parameter to changes the shape of pattern of the potential well in the NUT spacetime in comparison with mass-less NUT space-time. We compared the ISCO (innermost stable circular orbit), MBCO (marginally bound circular orbit) and CPO (circular photon orbit) of the said space-time with graphically in comparison with mass-less cases. Moreover, we compute the radius of ISCO, MBCO and CPO for \\emph{extreme} TN black hole. Interestingly, we show that these \\emph{three radii} coincides with the Killing horizon i.e. the null geodesic generators of the horizon. Finally in Appendix, we comput...

  6. Miniature magnetic bottle confined by circularly polarized laser light and measurements of the inverse Faraday effect in plasmas

    International Nuclear Information System (INIS)

    A new concept of hot plasma confinement in a miniature magnetic bottle induced by circularly polarized laser light is suggested. Magnetic fields generated by circularly polarized laser light may be of the order of megagauss, depending on the laser intensity. In this configuration the circularly polarized light is used to obtain confinement of a plasma contained in a good conductor vessel. The confinement in this scheme is supported by the magnetic forces. The Lawson criterion for a DT plasma might be achieved for number density n = 5*1021 cm-3 and confinement time τ= 20 ns. The laser and plasma parameters required to obtain an energetic gain are calculated. Experiments and preliminary calculations were performed to study the feasibility of the above scheme. Measurements of the axial magnetic field induced by circularly polarized laser light, the so called inverse Faraday effect, and of the absorption of circularly polarized laser light in plasma, are reported. The experiments were performed with a circularly polarized Nd:YAG laser, having a wavelength of 1.06 τm and a pulse duration of 7 ns, in a range of irradiances from 109 to 1014 W/cm2. Axial magnetic fields from 500 Gauss to 2 megagauss were measured. Up to 5*1013 W/cm3 the results are in agreement with a nonlinear model of the inverse Faraday effect dominated by the ponderomotive force. For the laser irradiance studied here, 9*1013 - 2.5*1014 W/cm2, the absorption of circularly polarized light was 14% higher relative to the absorption of linear polarized light

  7. Oil shale generators with circular retorting chamber

    International Nuclear Information System (INIS)

    The method of semi-coking oil shale in the circular retorting chamber makes it possible to ensure a more uniform distribution of the heat carriers gas across the shale bed, than in the vertically placed retorting chambers with cross-current heat carrier flow, and in the generators using the counter-current method of heat exchange. This also ensures the most favourable conditions for effective heat transfer in the retorting chamber from the gas flow to the shale bed due to the following factors: absence of the lateral outer walls in the retorting chamber; the concentrical arrangement of the retorting chamber and the passage of the gaseous heat carrier through the shale bed from the periphery of the retort to its center; the bulk of the oil shale charged passes through the hot part of the retorting chamber (i.e. on the side of inlet of the gaseous heat carrier into the shale bed). As a result, processing the oil shale in the generators with circular retorting chambers leads to a decrease in the temperature of oil vapours at the gas outlet on an average from 220 to 150o C and the reduction of the specific air consumption for the process - from 360 to 250 m3/t. According to the calculated data, it ensures an increase in oil yield from 78 to 84% of the Fischer assay oil. The application of the circular retorting chamber in the generators, creates conditions for increased unit throughput rates of the retorts 1.5-2.0 times with a simultaneous increase in the oil yield. For processing oil shales rich in organic material, which readily bitumenize, retorts for a throughput of 1500 tonnes per day have been developed and are already under construction at the P O 'Slantsekhim'. Project designs for the leaner shales can be developed for throughput rates in excess of 5000-6000 tonnes per day. The retorts will have a comparatively small diameter and a simpler design than the 1000 t/day generators being now in operation. (author). 14 refs., 2 tabs., fig

  8. Liquid crystal adaptive lens with circular electrodes

    Science.gov (United States)

    Sun, Yi

    The liquid crystal adaptive lens (LCAL) developed in this research is an electro-optical device using a set of electrodes to grade the refractive index across its aperture. Adjusting the applied voltages permits continuous control of focal length. The first effort at developing an LCAL using circular electrodes to provide a simpler architecture than previous devices using linear electrodes is presented in this dissertation. A theoretical study for an LCAL with circular electrodes is performed. The liquid crystal behavior and the applied voltage profile required for different focal lengths is discussed. Numerical simulation of the refractive index change and the Point Spread Function is developed to study the aberrations and predict performance with circular electrode geometry. A Fresnel lens phase profile is applied to yield a lens with a useful F-number, and a previously unexplored aberration is identified and characterized. An LCAL prototype was designed with a set of high-density electrodes in the conductive ladder meshing configuration, which results in a small number of externally controlled electrodes. A new electronic controller was designed and built with a fast response and accurate output to apply the voltage set to the LCAL. An electro-optical feedback control system based on LabVIEW software was developed to optimize control output voltages using signals from a CID camera. A prototype LCAL was designed with a 7.86 mm diameter aperture and a focal length adjustable from 0.2 m to infinity. It was fabricated on a glass substrate with two layers of transparent electrodes, insulating layers, and vias to connect the two conducting layers. The special fabrication challenges involved are discussed. Focusing experiments were performed by auto-dithering using the electro-optical feedback control system. The point spread function measurement results are presented, demonstrating that the focal spot size reaches the diffraction limit, but astigmatism created by the

  9. Constraint Differentiation

    DEFF Research Database (Denmark)

    Mödersheim, Sebastian Alexander; Basin, David; Viganò, Luca

    2010-01-01

    We introduce constraint differentiation, a powerful technique for reducing search when model-checking security protocols using constraint-based methods. Constraint differentiation works by eliminating certain kinds of redundancies that arise in the search space when using constraints to represent...... experimentation. Our results show that constraint differentiation substantially reduces search and considerably improves the performance of OFMC, enabling its application to a wider class of problems....

  10. SCATTERING OF SH-WAVES BY AN INTERACTING INTERFACE LINEAR CRACK AND A CIRCULAR CAVITY NEAR BIMATERIAL INTERFACE

    Institute of Scientific and Technical Information of China (English)

    LIU Diankui; LIN Hong

    2004-01-01

    An analytical method is developed for scattering of SH-waves and dynamic stress concentration by an interacting interface crack and a circular cavity near bimaterial interface. A suitable Green's function is contructed, which is the fundamental solution of the displacement field for an elastic half space with a circular cavity impacted by an out-plane harmonic line source loading at the horizontal surface. First, the bimaterial media is divided into two parts along the horizontal interface, one is an elastic half space with a circular cavity and the other is a complete half space.Then the problem is solved according to the procedure of combination and by the Green's function method. The horizontal surfaces of the two half spaces are loaded with undetermined anti-plane forces in order to satisfy continuity conditions at the linking section, or with some forces to recover cracks by means of crack-division technique. A series of Fredholm integral equations of first kind for determining the unknown forces can be set up through continuity conditions as expressed in terms of the Green's function. Moreover, some expressions are given in this paper, such as dynamic stress intensity factor (DSIF) at the tip of the interface crack and dynamic stress concentration factor (DSCF) around the circular cavity edge. Numerical examples are provided to show the influences of the wave numbers,the geometrical location of the interface crack and the circular cavity, and parameter combinations of different media upon DSIF and DSCF.

  11. Hybrid ion acceleration with ultrathin composite foils irradiated by high intensity circularly-polarized laser light

    International Nuclear Information System (INIS)

    A complete analytical description of ion acceleration in the laser radiation-pressure regime is presented. The combined effects of hot electron and light-pressure phenomena are used to qualitatively and quantitatively describe most recent experimental results in this regime. An essential part of the developed model is exhibited in the calculation of nonlinear laser light reflection and transmission properties, as well as in the spectral characterization of the laser light after interaction. The validity of the analytical model is supported by recent experimental results and by particle-in-cell simulations.

  12. Energetics, structures, vibrational frequencies, vibrational absorption, vibrational circular dichroism and Raman intensities of Leu-enkephalin

    DEFF Research Database (Denmark)

    Jalkanen, Karl J.

    2003-01-01

    can be compared to the measured VA, VCD and Raman spectra of LeuE in non-polar solvents to identify which conformer or conformers of LeuE are present in these media. Characteristic features in the VCD spectra are more sensitive to conformational changes than those in either the VA or Raman spectra...... species is higher than neutral species, in contradiction to experiment. Hence the use of explicit water molecules plus either this or another continuum model to treat the bulk water environment is necessary to make the zwitterionic species more stable than the neutral species. We are pursuing explicit...

  13. Differential manifolds

    CERN Document Server

    Kosinski, Antoni A

    2007-01-01

    The concepts of differential topology form the center of many mathematical disciplines such as differential geometry and Lie group theory. Differential Manifolds presents to advanced undergraduates and graduate students the systematic study of the topological structure of smooth manifolds. Author Antoni A. Kosinski, Professor Emeritus of Mathematics at Rutgers University, offers an accessible approach to both the h-cobordism theorem and the classification of differential structures on spheres.""How useful it is,"" noted the Bulletin of the American Mathematical Society, ""to have a single, sho

  14. Polarization-Dependence of Coulomb Explosion of CO Irradiated with an Intense Femtosecond Laser Pulse

    Institute of Scientific and Technical Information of China (English)

    陈建新; 马日; 任海振; 李霞; 杨宏; 龚旗煌

    2003-01-01

    Laser-induced Coulomb explosion of CO is studied experimentally using differently polarized femtosecond laser pulses of 2 × 1015 W/cm2 intensity at λ = 800 nm. The channels of molecular Coulomb explosion are observed to be independent of the laser polarizations. The critical distance R is deduced to be larger for the circularly polarized light in comparison with the linearly polarized light. The initial emissions of C+, C2+, O+, and O2+ions are anisotropic for linear polarization and isotropic for circular polarization. The suppression of ionization occurs for the elliptically and circularly polarized lasers.

  15. Transition from Poisson to circular unitary ensemble

    Indian Academy of Sciences (India)

    Vinayak; Akhilesh Pandey

    2009-09-01

    Transitions to universality classes of random matrix ensembles have been useful in the study of weakly-broken symmetries in quantum chaotic systems. Transitions involving Poisson as the initial ensemble have been particularly interesting. The exact two-point correlation function was derived by one of the present authors for the Poisson to circular unitary ensemble (CUE) transition with uniform initial density. This is given in terms of a rescaled symmetry breaking parameter Λ. The same result was obtained for Poisson to Gaussian unitary ensemble (GUE) transition by Kunz and Shapiro, using the contour-integral method of Brezin and Hikami. We show that their method is applicable to Poisson to CUE transition with arbitrary initial density. Their method is also applicable to the more general ℓ CUE to CUE transition where CUE refers to the superposition of ℓ independent CUE spectra in arbitrary ratio.

  16. Gravitational collapse of a circularly symmetric star

    CERN Document Server

    Sharma, Ranjan; Rahaman, Farook; Shit, Gopal Chandra

    2015-01-01

    We investigate the collapse of a circularly symmetric star with outgoing radiation in ($2+1$)-dimensional anti-de Sitter spacetime. The exterior spacetime of the collapsing star is assumed to be described by the non-static generalization of the Ba\\~nados, Teitelboim and Zanelli [{\\em Phys. Rev. Lett.} {\\bf 69} (1992) 1849 ] metric. Making use of the junction conditions joining smoothly the interior and the exterior spacetimes across the boundary, we analyze the impacts of various factors on the evolution of the star which begins its collapse from an initial static configuration. In particular, depending on initial conditions, two possible outcomes of the collapse process are shown: (i) formation of a BTZ black hole, and (ii) evaporation of all mass-energy even before the singularity is reached.

  17. Heavy ions at the Future Circular Collider

    CERN Document Server

    Dainese, A; Armesto, N; d'Enterria, D; Jowett, J M; Lansberg, J -P; Milhano, J G; Salgado, C A; Schaumann, M; van Leeuwen, M; Albacete, J L; Andronic, A; Antonioli, P; Apolinario, L; Bass, S; Beraudo, A; Bilandzic, A; Borsanyi, S; Braun-Munzinger, P; Chen, Z; Mendez, L Cunqueiro; Denicol, G S; Eskola, K J; Floerchinger, S; Fujii, H; Giubellino, P; Greiner, C; Grosse-Oetringhaus, J F; Ko, C -M; Kotko, P; Krajczar, K; Kutak, K; Laine, M; Liu, Y; Lombardo, M P; Luzum, M; Marquet, C; Masciocchi, S; Okorokov, V; Paquet, J -F; Paukkunen, H; Petreska, E; Pierog, T; Ploskon, M; Ratti, C; Rezaeian, A H; Riegler, W; Rojo, J; Roland, C; Rossi, A; Salam, G P; Sapeta, S; Schicker, R; Schmidt, C; Stachel, J; Uphoff, J; van Hameren, A; Watanabe, K; Xiao, B -W; Yuan, F; Zaslavsky, D; Zhou, K; Zhuang, P

    2016-01-01

    The Future Circular Collider (FCC) Study is aimed at assessing the physics potential and the technical feasibility of a new collider with centre-of-mass energies, in the hadron-hadron collision mode, seven times larger than the nominal LHC energies. Operating such machine with heavy ions is an option that is being considered in the accelerator design studies. It would provide, for example, Pb-Pb and p-Pb collisions at sqrt{s_NN} = 39 and 63 TeV, respectively, per nucleon-nucleon collision, with integrated luminosities above 30 nb^-1 per month for Pb-Pb. This is a report by the working group on heavy-ion physics of the FCC Study. First ideas on the physics opportunities with heavy ions at the FCC are presented, covering the physics of the Quark-Gluon Plasma, of gluon saturation, of photon-induced collisions, as well as connections with other fields of high-energy physics.

  18. On inner constraints in plane circular arches

    Energy Technology Data Exchange (ETDEWEB)

    Ruta, G.C. [Universita di Roma ' ' La Sapienza' ' , Dipartimento di Ingegneria Strutturale e Geotecnica, via Eudossiana 18, I-00184 Roma (Italy)

    2004-12-01

    A one-dimensional model of plane circular arches with rigid sections is introduced. Suitable strain measures are defined as deviations from rigid displacements. If the arch is thin, constitutive arguments make the shearing strain negligible. Hence, the shearing indeformability will be assumed as inner constraint. By means of a formal power series expansion of the exact measures of deformation it is shown that the shearing indeformability implies some constraints on the axial strain. In particular, the first-order axial strain must vanish in the case of infinitesimal displacements. The same procedure is applied to pure flexible arches, in order to compare the two sets of results. It is shown that the hypothesis of finite pure flexibility is not compatible with small deformations of the arch. An example is provided to evaluate the effects of the two constraints at the first non-linear step of the perturbation expansions. (orig.)

  19. Omnidirectional, circularly polarized, cylindrical microstrip antenna

    Science.gov (United States)

    Stanton, Philip H. (Inventor)

    1985-01-01

    A microstrip cylindrical antenna comprised of two concentric subelements on a ground cylinder, a vertically polarized (E-field parallel to the axis of the antenna cylinder) subelement on the inside and a horizontally polarized (E-field perpendicular to the axis) subelement on the outside. The vertical subelement is a wraparound microstrip radiator. A Y-shaped microstrip patch configuration is used for the horizontally polarized radiator that is wrapped 1.5 times to provide radiating edges on opposite sides of the cylindrical antenna for improved azimuthal pattern uniformity. When these subelements are so fed that their far fields are equal in amplitude and phased 90.degree. from each other, a circularly polarized EM wave results. By stacking a plurality of like antenna elements on the ground cylinder, a linear phased array antenna is provided that can be beam steered to the desired elevation angle.

  20. Wideband Circularly Polarized Dielectric Rod Antenna

    Directory of Open Access Journals (Sweden)

    Min Guo

    2012-01-01

    Full Text Available A new dielectric rod antenna (DRA is introduced to produce circular polarization (CP over a wide frequency band without a complex feed network. Along with the simulated results, measured results of the antenna prototype are presented, showing a 3 dB axial ratio (AR CP bandwidth of 17.7%. The radiation characteristics of the fabricated antenna are also demonstrated showing the measured gain of better than 6.2 dBi. Moreover, the measured impedance bandwidth (VSWR ≤2 reaches 20.1%, from 8.75 GHz to 10.7 GHz, while the CP beamwidth (AR ≤3 dB at the central frequency is measured over 120°.

  1. Tangent hyperbolic circular frequency diverse array radars

    Directory of Open Access Journals (Sweden)

    Sarah Saeed

    2016-03-01

    Full Text Available Frequency diverse array (FDA with uniform frequency offset (UFO has been in spot light of research for past few years. Not much attention has been devoted to non-UFOs in FDA. This study investigates tangent hyperbolic (TH function for frequency offset selection scheme in circular FDAs (CFDAs. Investigation reveals a three-dimensional single-maximum beampattern, which promises to enhance system detection capability and signal-to-interference plus noise ratio. Furthermore, by utilising the versatility of TH function, a highly configurable type array system is achieved, where beampatterns of three different configurations of FDA can be generated, just by adjusting a single function parameter. This study further examines the utility of the proposed TH-CFDA in some practical radar scenarios.

  2. Rectenna composed of a circular microstrip antenna

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, K.; Ohgane, T.; Ogawa, Y.

    1986-01-01

    One of the big problems in the SPS system is reradiation of the harmonic waves generated by the rectifying diode. The authors proposed the use of a circular microstrip antenna (CMSA), since the CMSA has no higher resonance-harmonic of integer multiple of the dominant resonance frequency. However, characteristics of a large rectenna array of CMSA's have not been clarified. This paper is concerned with the absorption efficiency of the rectenna composed of the CMSA. The efficiency is estimated explicitly using an infinite array model. The results show that the absorption efficiency of the infinite rectenna array composed of the CMSA is 100%. Also, this paper considers the effect of the losses of the composed of the CMSA is 100%. Also, this paper considers the effect of the losses of the CMSA. 4 references, 4 figures.

  3. Circular arc snakes and kinematic surface generation

    KAUST Repository

    Barton, Michael

    2013-05-01

    We discuss the theory, discretization, and numerics of curves which are evolving such that part of their shape, or at least their curvature as a function of arc length, remains unchanged. The discretization of a curve as a smooth sequence of circular arcs is well suited for such purposes, and allows us to reduce evolution of curves to the evolution of a control point collection in a certain finite-dimensional shape space. We approach this evolution by a 2-step process: linearized evolution via optimized velocity fields, followed by optimization in order to exactly fulfill all geometric side conditions. We give applications to freeform architecture, including "rationalization" of a surface by congruent arcs, form finding and, most interestingly, non-static architecture. © 2013 The Author(s) Computer Graphics Forum © 2013 The Eurographics Association and Blackwell Publishing Ltd.

  4. 3D measurement using circular gratings

    Science.gov (United States)

    Harding, Kevin

    2013-09-01

    3D measurement using methods of structured light are well known in the industry. Most such systems use some variation of straight lines, either as simple lines or with some form of encoding. This geometry assumes the lines will be projected from one side and viewed from another to generate the profile information. But what about applications where a wide triangulation angle may not be practical, particularly at longer standoff distances. This paper explores the use of circular grating patterns projected from a center point to achieve 3D information. Originally suggested by John Caulfield around 1990, the method had some interesting potential, particularly if combined with alternate means of measurement from traditional triangulation including depth from focus methods. The possible advantages of a central reference point in the projected pattern may offer some different capabilities not as easily attained with a linear grating pattern. This paper will explore the pros and cons of the method and present some examples of possible applications.

  5. TRIPLET CIRCULAR HOUGH TRANSFORM FOR CIRCLE DETECTION

    Institute of Scientific and Technical Information of China (English)

    Luo Daisheng; He Xiaohai; Teng Qizhi; Tao Qingchuan

    2002-01-01

    A new method, triplet circular Hough transform, is proposed for circle detection in image processing and pattern recognition. In the method, a curve in an image is first detected.Next, a sequence of three points on the curve are selected, a sequence of parameters (a,b,r)corresponding to the three points are calculated by solving the circle equation of the curve, and two 2-D accumulators A(a,b) and R(a,b) are accumulated with 1 and r, respectively. Then the parameters {(a, b, r)} of the circles fitting the curve are determined from A(a, b) and R(a, b) by searching for the local maximum over A(a,b). Because no computation loops over center (a, b)and/or radius r are needed, the method is faster than the basic and directional gradient methods.It needs also much smaller memory for accumulation.

  6. Unsteady compressible boundary layer flow over a circular cone near aplane of symmetry

    OpenAIRE

    Chamkha, AJ; Takhar, HS; G. Nath

    2005-01-01

    An analysis has been performed to study the unsteady laminar compressible boundary layer governing the hypersonic flow over a circular cone at an angle of attack near a plane of symmetry with either in flow or out flow in the presence of suction. The flow is assumed to be steady at time t= 0 and at t > 0 it becomes unsteady due to the time-dependent free stream velocity which varies arbitrarily with time. The nonlinear coupled parabolic partial differential equations under boundary layer a...

  7. Free vibration of symmetric angle-ply laminated circular cylindrical shells

    International Nuclear Information System (INIS)

    Free vibration of symmetric angle-ply laminated circular cylindrical shells is studied using Spline approximation. The equations of motions in longitudinal, circumferential and transverse displacement components, are derived using Love's first approximation theory. The coupled differential equations are solved using Spline approximation to obtain the generalized eigenvalue problem. Parametric studies are performed to analyse the frequency response of the shell with reference to the material properties, number of layers, ply orientation, length and circumferential node number and different boundary conditions

  8. THE COUPLING IMPEDANCE OF A TOROIDAL BEAM TUBE WITH CIRCULAR CROSS SECTION

    International Nuclear Information System (INIS)

    IN THIS PAPER, THE LONGITUDINAL COUPLING IMPEDANCE OF A TOROIDAL BEAM TUBE WITH CIRCULAR CROSS SECION IS DERIVED IN THE FREQUENCY DOMAIN USING THE TOROIDAL COORDINATE SYSTEM. EXACT, ALTHOUGH COUPLED, DIFFERENTIAL EQUATIONS FOR THE AZIMUTHAL FIELD COMPONENTS ARE OBTAINED. AN APPROXIAMTE SOLUTION, VALID IN THE LIMIT OF SMALL CURVATURE, IS THEN DERIVED. ASSUMING EXTREME RELATIVISTIC ENERGIES AND A BEAM TUBE WITH PERFECTLY CONDUCTING WALLS, ONE FINDS A CLOSED-FORM EXPRESSION FOR THE PURELY REACTIVE COUPLING IMPEDANCE WHICH AT LOW MODE NUMBERS IS DEPENDENT ON THE TUBE GEOMETRY BUT WHICH AT VERY LARGE MODE NUMBERS APPROACHES THE FREE SPACE IMPEDANCE

  9. Thermohydraulics of Turbulent Flow Through Heat Exchanger Tubes Fitted with Circular-rings and Twisted Tapes

    Institute of Scientific and Technical Information of China (English)

    Smith Eiamsa-ard; Vichan Kongkaitpaiboon; Kwanchai Nanan

    2013-01-01

    The influences of circular-ring turbulators (CRT) and twisted tape (TT) swirl generators on the heat transfer enhancement,pressure drop and thermal performance factor characteristics in a round tube are reported.The circular-ring turbulators were individually employed and together with the twisted tape swirl generators in the heated section of the tube.Three different pitch ratios (l/D =1.0,1.5,and 2.0) of the CRT and three different twist ratios (y/W=3,4,and 5) of the TT were introduced.The experiments were conducted using air as the working fluid under a uniform wall heat flux condition,for the Reynolds number between 6000 and 20000.The experimental resuits reveal that the heat transfer rate,friction factor and thermal performance factor of the combined CRT and TT are considerably higher than those of CRT alone.For the range examined,the ìncreases of mean Nusselt number,friction factor and thermal performance,in the tube equipped with combined devices,respectively,are 25.8%,82.8% and 6.3% over those in the tube with the CRT alone.The highest thermal performance factor of 1.42 is found for the combined device consisting of the CRT with l/D =1.0 and TT with y/W=3.The correlations of the Nusselt number,friction factor and thermal performance factor of the tubes with combined devices are also developed in terms of Reynolds number,Prandtl number,twist ratio and pitch ratio.

  10. Spatial-temporal differentiation of urban land area expansion intensity and the influence factors in Guizhou%贵州省城镇用地扩展强度时空分异及影响因素

    Institute of Scientific and Technical Information of China (English)

    周志明; 李阳兵; 张元洪; 罗光杰

    2012-01-01

    The land use data are acquired from the TM images of 1995, 2000, 2007 with the aid of Erdas and Arcview software. The urban expansion intensity index in every county of Guizhou are calculated and the influence factors to the expansion of urban and town involving transportation, economy and natural conditions are analyzed. The results show that:1) there are 16 cities and towns with high expansion speed from 2001 to 2007, but in the period of 1995-2000 there are only 5 cities and towns with high expansion speed;2) big cities on the North-South traffic axis (Zun-Chong Expressway, Gui-Zun Expressway, Gui-Xin Expressway, State Road 210) and East-West traffic axis (Kai-Ma Expressway, Gui-Huang Expressway, State Road 320) expand faster, and the rapidly expanding locations appear near the center of traffic intersection and this trend gets more and more obvious; 3) in view of the expansion intensity grade, the expansion intensity gradually increases, from low speed, low-medium speed, medium speed, medium-high speed to high speed. There is a direct proportion between the grade of road and the urban expansion intensity, in other words, the high the grade of road, the larger the urban land area expansion intensity along the road. Economy is an important factor to urban expansion, high speed development of economy strengthens urban expansion. Flat landform is beneficial to urban expansion, while uneven land can impede urban expansion.%以贵州省1995年、2000年、2007年TM遥感影像资料为数据源,利用Erdas软件对该三期影像进行矫正和监督分类,应用ArcView进行修改.然后,再以ArcGIS空间分析模块,提取贵州省1995年、2000年、2007年三个时期的城镇土地利用数据.在此基础上,运用城镇扩展强度指数公式计算城镇扩展强度指数,并从交通、经济和自然环境等方面对贵州省城镇土地利用扩展的影响因素进行分析研究.结果表明:(1)2001-2007年,高速扩展城镇16个,高于1995-2000

  11. Flow-induced vibration of circular cylindrical structures

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S.S.

    1985-06-01

    This report summarizes the flow-induced vibration of circular cylinders in quiescent fluid, axial flow, and crossflow, and applications of the analytical methods and experimental data in design evaluation of various system components consisting of circular cylinders. 219 figs., 30 tabs. (JDB)

  12. THE PROJECTIVE PLANE CROSSING NUMBERS OF CIRCULAR GRAPHS

    Institute of Scientific and Technical Information of China (English)

    Dengju MA; Han REN

    2008-01-01

    The authors give an upper bound for the projective plane crossing number of a circular graph. Also, the authors prove the projective plane crossing numbers of circular graph C (8,3) and C (9,3) are 2 and 1, respectively.

  13. Flow-induced vibration of circular cylindrical structures

    International Nuclear Information System (INIS)

    This report summarizes the flow-induced vibration of circular cylinders in quiescent fluid, axial flow, and crossflow, and applications of the analytical methods and experimental data in design evaluation of various system components consisting of circular cylinders. 219 figs., 30 tabs

  14. Calculations of circular waveguide with a rectangular metal insert.

    Directory of Open Access Journals (Sweden)

    Yu. K. Sydoruk

    2010-05-01

    Full Text Available Calculated and analyzed the basic parameters of electromagnetic wave in a circular waveguide with a rectangular metal plate in the following cases: when  the circular waveguide without metal plate for a H11 wave of subcritical, critical and supercritical. For calculations was used a finite element method and Ansoft HFSS program.

  15. On the Recognition of Fuzzy Circular Interval Graphs

    CERN Document Server

    Oriolo, Gianpaolo; Stauffer, Gautier

    2011-01-01

    Fuzzy circular interval graphs are a generalization of proper circular arc graphs and have been recently introduced by Chudnovsky and Seymour as a fundamental subclass of claw-free graphs. In this paper, we provide a polynomial-time algorithm for recognizing such graphs, and more importantly for building a suitable representation.

  16. Structures of generalized 3-circular projections for symmetric norms

    Indian Academy of Sciences (India)

    A B Abubaker; S Dutta

    2016-05-01

    Recently several authors investigated structures of generalized bi-circular projections in spaces where the descriptions of the group of surjective isometries are known. Following the same idea in this paper we give complete descriptions of generalized 3-circular projections for symmetric norms on ${\\mathbb C}^n$ and ${\\mathbb M}_{m \\times n}({\\mathbb C})$.

  17. GRAPHS WHOSE CIRCULAR CLIQUE NUMBER EQUAL THE CLIQUE NUMBER

    Institute of Scientific and Technical Information of China (English)

    XU Baogang; ZHOU Xinghe

    2005-01-01

    The circular clique number of a graph G is the maximum fractional k/d such that Gkd admits a homomorphism to G. In this paper, we give some sufficient conditions for graphs whose circular clique number equal the clique number, we also characterize the K1,3-free graphs and planar graphs with the desired property.

  18. LARGE DEFORMATION OF CIRCULAR MEMBRANE UNDER THE CONCENTRATED FORCE

    Institute of Scientific and Technical Information of China (English)

    陈山林; 郑周练

    2003-01-01

    Making use of basic equation of large deformation of circular membrane underthe concentrated force and its boundary conditions and Hencky transformation, the problemsof nonlinear boundary condition were solved. The Hencky transformation was extended anda exact solution of large deformation of circular membrane under the concentrated force hasbeen obtained.

  19. Modal radiation patterns of baffled circular plates and membranes

    DEFF Research Database (Denmark)

    Christiansen, Thomas Lehrmann; Hansen, Ole; Thomsen, Erik Vilain;

    2014-01-01

    The far field velocity potential and radiation pattern of baffled circular plates and membranes are found analytically using the full set of modal velocity profiles derived from the corresponding equation of motion. The derivation is valid for a plate or membrane subjected to an external excitation...... circular radiator....

  20. Circularization pathway of a bacterial group II intron.

    Science.gov (United States)

    Monat, Caroline; Cousineau, Benoit

    2016-02-29

    Group II introns are large RNA enzymes that can excise as lariats, circles or in a linear form through branching, circularization or hydrolysis, respectively. Branching is by far the main and most studied splicing pathway while circularization was mostly overlooked. We previously showed that removal of the branch point A residue from Ll.LtrB, the group II intron from Lactococcus lactis, exclusively leads to circularization. However, the majority of the released intron circles harbored an additional C residue of unknown origin at the splice junction. Here, we exploited the Ll.LtrB-ΔA mutant to study the circularization pathway of bacterial group II introns in vivo. We demonstrated that the non-encoded C residue, present at the intron circle splice junction, corresponds to the first nt of exon 2. Intron circularization intermediates, harboring the first 2 or 3 nts of exon 2, were found to accumulate showing that branch point removal leads to 3' splice site misrecognition. Traces of properly ligated exons were also detected functionally confirming that a small proportion of Ll.LtrB-ΔA circularizes accurately. Overall, our data provide the first detailed molecular analysis of the group II intron circularization pathway and suggests that circularization is a conserved splicing pathway in bacteria. PMID:26673697

  1. REFLOW OF NON-CIRCULAR NANO-PILLARS TO FABRICATE NANO-SCALE SOLID IMMERSION LENSES

    OpenAIRE

    Kim, Myun-Sik; Keeler, Ethan; Rydberg, Skyler; Nakagawa, Wataru; Osowiecki, Gaël David; Scharf, Toralf; Herzig, Hans Peter

    2012-01-01

    We investigate the reflow of non-circular, i.e., triangular and square, shaped pillars to fabricate nano-scale solid immersion lenses (SILs). Electron beam lithography (EBL) and thermal reflow are the core of the fabrication process. For the optical characterization at lambda = 642 nm, nano-SILs are replicated on a transparent substrate by soft lithography. The focal spots produced by the nano-SILs show both spot-size reduction and peak-intensity enhancement, which are consistent with the imm...

  2. Wiebel instability of microwave gas discharge in strong linear and circular pulsed fields

    International Nuclear Information System (INIS)

    Being much weaker than the atomic fields, the gas breakdown produced by high-power pulsed microwave fields is investigated in the nonrelativistic case. The distribution function of the electrons produced by the interaction with intense linearly and circularly polarized microwave fields is obtained and it is shown that it is in a nonequilibrium state and anisotropic. The discharge mechanism for the gas atoms is governed by electron-impact avalanche ionization. By analyzing the instability of the system and by finding its growth rate, it is shown that the instability which is governed by the anisotropic property of the distribution function is Wiebel instability

  3. Bifurcation and chaos of thin circular functionally graded plate in thermal environment

    Energy Technology Data Exchange (ETDEWEB)

    Hu Yuda, E-mail: huyuda03@163.com [School of Civil Engineering and Mechanics, Yanshan University, Qinhuangdao 066004 (China); Zhang Zhiqiang, E-mail: zhangzqvib@126.com [School of Civil Engineering and Mechanics, Yanshan University, Qinhuangdao 066004 (China)

    2011-09-15

    Highlights: > We study bifurcations and chaotic dynamics of a FGM circular plate. > We consider the effect of temperature-dependent material properties. > Increasing volume fraction index will increase chaotic regions. > Increasing temperature will reduce chaotic regions. > The FGM plate exists chaotic motions, multiple periodic and periodic motions. - Abstract: A ceramic/metal functionally graded circular plate under one-term and two-term transversal excitations in the thermal environment is investigated, respectively. The effects of geometric nonlinearity and temperature-dependent material properties are both taken into account. The material properties of the functionally graded plate are assumed to vary continuously through the thickness, according to a power law distribution of the volume fraction of the constituents. Using the principle of virtual work, the nonlinear partial differential equations of FGM plate subjected to transverse harmonic forcing excitation and thermal load are derived. For the circular plate with clamped immovable edge, the Duffing nonlinear forced vibration equation is deduced using Galerkin method. The criteria for existence of chaos under one-term and two-term periodic perturbations are given with Melnikov method. Numerical simulations are carried out to plot the bifurcation curves for the homolinic orbits. Effects of the material volume fraction index and temperature on the criterions are discussed and the existences of chaos are validated by plotting phase portraits, Poincare maps. Also, the bifurcation diagrams and corresponding maximum Lyapunov exponents are plotted. It was found that periodic, multiple periodic solutions and chaotic motions exist for the FGM plate under certain conditions.

  4. Circular Interpolation Algorithms of 5-Axis Simultaneous CNC System

    Institute of Scientific and Technical Information of China (English)

    ZHENG Kuijing; SHANG Bo

    2006-01-01

    Spatial circular arc can be machined conveniently by a 5-axis NC machine tool. Based on the data sampling method, circular interpolation in two-dimensional plane is discussed briefly. The key is to solve the problem of circular center expressed in the workpiece coordinate system by means of the transformation matrix. Circular interpolation in three-dimensional space is analyzed in detail. The method of undetermined coefficient is used to solve the center of the spatial circle and the method of coordinate transformation is used to transform the spatial circle into the XY_plane. Circular arc in three-dimensional space can be machined by the positional 5-axis machining and the conical surface can be machined by the continuous 5-axis machining. The velocity control is presented to avoid the feedrate fluctuation. The interpolation algorithms are tested by a simulation example and the interpolation algorithms are proved feasible. The algorithms are applied to the 5-axis CNC system software.

  5. Conversion from linear to circular polarization in FPGA

    CERN Document Server

    Das, Koyel; Keller, R; Tuccari, G

    2011-01-01

    Context: Radio astronomical receivers are now expanding their frequency range to cover large (octave) fractional bandwidths for sensitivity and spectral flexibility, which makes the design of good analogue circular polarizers challenging. Better polarization purity requires a flatter phase response over increasingly wide bandwidth, which is most easily achieved with digital techniques. They offer the ability to form circular polarization with perfect polarization purity over arbitrarily wide fractional bandwidths, due to the ease of introducing a perfect quadrature phase shift. Further, the rapid improvements in field programmable gate arrays provide the high processing power, low cost, portability and reconfigurability needed to make practical the implementation of the formation of circular polarization digitally. Aims: Here we explore the performance of a circular polarizer implemented with digital techniques. Methods: We designed a digital circular polarizer in which the intermediate frequency signals from...

  6. Choke position effects in double-choked circular waveguide antennas

    Science.gov (United States)

    Miyata, K.; Suzuki, M.

    1984-06-01

    A number of studies have been conducted regarding choke-loaded circular waveguide antennas. Aoki et al. (1970) have obtained improved results with respect to the beam circularity and the wide-angle radiation properties. Cowan (1973) suggested the employment of suitable compact, double choked feeds for frequency-reuse application. Further improvements can apparently be obtained by loading double chokes on a circular waveguide. The present investigation is concerned with the variation of the radiated fields for various choke positions in double-choked circular waveguide antennas. In the case of double-choked small circular waveguide antennas, it is found that the choke position has a pronounced effect on the radiation properties. Particularly sensitive to the choke position is the cross-polar level.

  7. Circularization of Tidally Disrupted Stars around Spinning Supermassive Black Holes

    CERN Document Server

    Hayasaki, Kimitake; Loeb, Abraham

    2015-01-01

    We study the circularization of tidally disrupted stars on bound orbits around spinning supermassive black holes by performing three-dimensional smoothed particle hydrodynamic simulations with Post-Newtonian corrections. Our simulations reveal that debris circularization depends sensitively on the efficiency of radiative cooling. There are two stages in debris circularization if radiative cooling is inefficient: first, the stellar debris streams self-intersect due to relativistic apsidal precession; shocks at the intersection points thermalize orbital energy and the debris forms a geometrically thick, ring-like structure around the black hole. The ring rapidly spreads via viscous diffusion, leading to the formation of a geometrically thick accretion disk. In contrast, if radiative cooling is efficient, the stellar debris circularizes due to self-intersection shocks and forms a geometrically thin ring-like structure. In this case, the dissipated energy can be emitted during debris circularization as a precurso...

  8. Detection of circular polarization in light scattered from photosynthetic microbes

    CERN Document Server

    Sparks, William B; Germer, Thomas A; Chen, Feng; DasSarma, Shiladitya; DasSarma, Priya; Robb, Frank T; Manset, Nadine; Kolokolova, Ludmilla; Reid, Neill; Macchetto, F Duccio; Martin, William; 10.1073/pnas.0810215106

    2009-01-01

    The identification of a universal biosignature that could be sensed remotely is critical to the prospects for success in the search for life elsewhere in the universe. A candidate universal biosignature is homochirality, which is likely to be a generic property of all biochemical life. Due to the optical activity of chiral molecules, it has been hypothesized that this unique characteristic may provide a suitable remote sensing probe using circular polarization spectroscopy. Here, we report the detection of circular polarization in light scattered by photosynthetic microbes. We show that the circular polarization appears to arise from circular dichroism of the strong electronic transitions of photosynthetic absorption bands. We conclude that circular polarization spectroscopy could provide a powerful remote sensing technique for generic life searches.

  9. Nearest Neighbor Estimates of Entropy for Multivariate Circular Distributions

    Directory of Open Access Journals (Sweden)

    Neeraj Misra

    2010-05-01

    Full Text Available In molecular sciences, the estimation of entropies of molecules is important for the understanding of many chemical and biological processes. Motivated by these applications, we consider the problem of estimating the entropies of circular random vectors and introduce non-parametric estimators based on circular distances between n sample points and their k th nearest neighbors (NN, where k (≤ n – 1 is a fixed positive integer. The proposed NN estimators are based on two different circular distances, and are proven to be asymptotically unbiased and consistent. The performance of one of the circular-distance estimators is investigated and compared with that of the already established Euclidean-distance NN estimator using Monte Carlo samples from an analytic distribution of six circular variables of an exactly known entropy and a large sample of seven internal-rotation angles in the molecule of tartaric acid, obtained by a realistic molecular-dynamics simulation.

  10. Administrative Circular No. 26 (Rev.10) - Recognition of merit

    CERN Multimedia

    2014-01-01

    Administrative Circular No. 26 (Rev. 10) entitled “Recognition of Merit”, approved by the Director-General following discussion at the Standing Concertation Committee meeting of 5 December 2013 and entering into force on 1 January 2014, is available on the intranet site of the Human Resources Department (see here).   This circular is applicable to staff members. It cancels and replaces Administrative Circular No. 26 (Rev. 9) entitled “Recognition of Merit” of December 2011. The circular was revised in order to take into account the work performed in the framework of an elective mandate during the exercise of merit recognition of staff members. In addition, the circular was revised to provide that, in the case of staff members on special leave for professional reasons for a period equal to or longer than half a year, it will no longer be possible to grant an exceptional advancement. Department Head Office HR Department

  11. The Diagonal Compression Field Method using Circular Fans

    DEFF Research Database (Denmark)

    Hansen, Thomas

    2006-01-01

    modification of the traditional method, the modification consisting of the introduction of circular fan stress fields. To ensure proper behaviour for the service load the -value ( = cot, where  is the angle relative to the beam axis of the uniaxial concrete compression) chosen should not be too large. As a...... increased in regions with low shear stresses. Thus the shear reinforcement would be reduced and the concrete strength would be utilized in a better way. In the paper it is shown how circular fan stress fields may be used whenever changes in the concrete compression direction are desired. Between two...... homogeneous stress regions a circular fan stress field may be used to change the inclination of the concrete compression. Unfortunately, the circular fan stress field becomes strongly inhomogeneous if the angle between the two inclined faces limiting the fan becomes large. Thus normally more than one circular...

  12. Analysis of electroluminescence images in small-area circular CdTe solar cells

    Science.gov (United States)

    Bokalič, Matevž; Raguse, John; Sites, James R.; Topič, Marko

    2013-09-01

    The electroluminescence (EL) imaging process of small area solar cells is investigated in detail to expose optical and electrical effects that influence image acquisition and corrupt the acquired image. An approach to correct the measured EL images and to extract the exact EL radiation as emitted from the photovoltaic device is presented. EL images of circular cadmium telluride (CdTe) solar cells are obtained under different conditions. The power-law relationship between forward injection current and EL emission and a negative temperature coefficient of EL radiation are observed. The distributed Simulation Program with Integrated Circuit Emphasis (SPICE®) model of the circular CdTe solar cell is used to simulate the dark J-V curve and current distribution under the conditions used during EL measurements. Simulation results are presented as circularly averaged EL intensity profiles, which clearly show that the ratio between resistive parameters determines the current distribution in thin-film solar cells. The exact resistance values for front and back contact layers and for CdTe bulk layer are determined at different temperatures, and a negative temperature coefficient for the CdTe bulk resistance is observed.

  13. Backward stimulated radiation from filaments in Nitrogen gas and air pumped by circularly polarized 800 nm femtosecond laser pulses

    OpenAIRE

    Mitryukovskiy, Sergey; Liu, Yi; Ding, PengJi; Houard, Aurélien; Mysyrowicz, André

    2014-01-01

    We report on strong backward stimulated emission at 337 nm in Nitrogen gas pumped by circularly polarized femtosecond laser pulses at 800 nm. A distinct dependence of the backward UV spectrum on pump laser polarization and intensity is observed, pointing to the occurrence of backward amplified spontaneous emission inside filaments. We attribute the population inversion to inelastic collision between the free electrons produced by the pump laser and neutral N 2 molecules. The addition of Oxyge...

  14. Differential games

    CERN Document Server

    Friedman, Avner

    2006-01-01

    This volume lays the mathematical foundations for the theory of differential games, developing a rigorous mathematical framework with existence theorems. It begins with a precise definition of a differential game and advances to considerations of games of fixed duration, games of pursuit and evasion, the computation of saddle points, games of survival, and games with restricted phase coordinates. Final chapters cover selected topics (including capturability and games with delayed information) and N-person games.Geared toward graduate students, Differential Games will be of particular interest

  15. Forced Convection Heat Transfer in Circular Pipes

    Science.gov (United States)

    Tosun, Ismail

    2007-01-01

    One of the pitfalls of engineering education is to lose the physical insight of the problem while tackling the mathematical part. Forced convection heat transfer (the Graetz-Nusselt problem) certainly falls into this category. The equation of energy together with the equation of motion leads to a partial differential equation subject to various…

  16. Frequency analysis of the non-principal-axis rotation of uniaxial space debris in circular orbit subjected to gravity-gradient torque

    Science.gov (United States)

    Lin, Hou-Yuan; Zhao, Chang-Yin; Zhang, Ming-Jiang

    2016-03-01

    The non-principal-axis rotational motion of uniaxial space debris can be decomposed into periodic motions associated with two frequencies: the polhode frequency of the space debris rotating around the symmetry axis, and the tumbling frequency of the symmetry axis rotating around the angular momentum. To determine from optical measurements the rotational motion of upper rocket stages in circular orbits subjected to gravity-gradient torque, the evolutions of these two frequencies need to be analyzed. Taking into account only the long-term changes in the long-period variables, the differential equations of the non-principal axis rotational motion of the uniaxial space debris are averaged and reduced, from which the evolutions of the polhode and tumbling frequencies are then obtained analytically. The theoretical results are verified by numerical simulations of the diffuse reflection model. The frequencies in the variation of the reflected light intensity in the simulation are analyzed using the frequency map analysis (FMA) method. Errors of these results are found to be less than 1%. Based on the theoretical expressions, the rotational state of the uniaxial space debris can be estimated in the simulation without any prior information except the orbital parameters. A series of state variables are estimated, including the ratio of the moments of inertia about the transverse axis and the symmetry axis, the instantaneous rotation velocity, the orientation of the angular momentum, and the precession cone of the symmetry axis.

  17. Differential topology

    CERN Document Server

    Mukherjee, Amiya

    2015-01-01

    This book presents a systematic and comprehensive account of the theory of differentiable manifolds and provides the necessary background for the use of fundamental differential topology tools. The text includes, in particular, the earlier works of Stephen Smale, for which he was awarded the Fields Medal. Explicitly, the topics covered are Thom transversality, Morse theory, theory of handle presentation, h-cobordism theorem, and the generalised Poincaré conjecture. The material is the outcome of lectures and seminars on various aspects of differentiable manifolds and differential topology given over the years at the Indian Statistical Institute in Calcutta, and at other universities throughout India. The book will appeal to graduate students and researchers interested in these topics. An elementary knowledge of linear algebra, general topology, multivariate calculus, analysis, and algebraic topology is recommended.

  18. Challenges for highest energy circular colliders

    CERN Document Server

    Benedikt, M; Wenninger, J; Zimmermann, F

    2014-01-01

    A new tunnel of 80–100 km circumference could host a 100 TeV centre-of-mass energy-frontier proton collider (FCC-hh/VHE-LHC), with a circular lepton collider (FCCee/TLEP) as potential intermediate step, and a leptonhadron collider (FCC-he) as additional option. FCC-ee, operating at four different energies for precision physics of the Z, W, and Higgs boson and the top quark, represents a significant push in terms of technology and design parameters. Pertinent R&D efforts include the RF system, topup injection scheme, optics design for arcs and final focus, effects of beamstrahlung, beam polarization, energy calibration, and power consumption. FCC-hh faces other challenges, such as high-field magnet design, machine protection and effective handling of large synchrotron radiation power in a superconducting machine. All these issues are being addressed by a global FCC collaboration. A parallel design study in China prepares for a similar, but smaller collider, called CepC/SppC.

  19. SEAMLESS TECHNOLOGY ON CIRCULAR KNITTING MACHINES

    Directory of Open Access Journals (Sweden)

    CRETU Viorica

    2014-05-01

    Full Text Available With industrial progress, the advancements in garment manufacturing have evolved from cut & sew to complete garment knitting, which produces one entire garment without sewing or linking process. Seamless knitting technology is similar to sock manufacture, the specialized circular knitting machines producing 3 dimensional garments with no side seams, with the waistband integrated with body of the garment and with knitted washing instructions and logos. The paper starts by presenting the main advantages of seamless garments but also some limitations because the technology. Because for a seamless garment, which is realized as a knitted tub, is very important to ensure the required final chest size, it was presented the main components involved: the knitting machine, the garment design and the yarns used. The knitting machines, beside the values of diameters and gauges with a great impact on the chest size, are characterized by a very innovative and complex construction. The design of a seamless garment is fundamental different compared to garments produced on a traditional way because the designer must to work backwards from a finished garment to create the knitting programme that will ultimately give the correct finished size. On the end of the paper it was presented some of the applications of the seamless products that cover intimate apparel and other bodywear, outwear, activewear and functional sportswear, upholstery, industrial, automotive and medical textiles.

  20. Magnetoresistance of single Permalloy circular rings

    International Nuclear Information System (INIS)

    We have measured magnetoresistance in single, 1 μm external diameter, Permalloy (Ni80Fe20) circular rings with varied inner hole diameter of 150, 300, and 600 nm and film thickness of 25 nm. The Permalloy ring structures and the 10-nm-thick, 250-nm-wide Au nanocontacts were fabricated on a SiO2/Si substrate using e-beam lithography. Using a four contact geometry we studied the dependence of the magnetoresistance on the direction of the applied field. The experimental data are explained by considering only the conventional anisotropic magnetoresistance effect. Numerical simulations of the current distribution within the samples combined with micromagnetic simulations of the field dependent magnetization profile, yield good agreement with the experimental data. Upon increasing the inner hole diameter (viz. decreasing the ring width) the magnetoresistance measurements show a transition of the reversal process from the 'vortex nucleation-displacement-annihilation' sequence to the 'onion state-reversed onion state' sequence, typical of narrow nanorings

  1. Superfluid Turbulence in a Nonuniform Circular Channel

    Science.gov (United States)

    Murphy, Paul Joseph

    The excess dissipation due to the presence of quantized vorticity in flowing helium has been studied extensively. The success of the microscopic theory proposed by Schwarz in describing many properties of this dissipation led to a belief that the major aspects of the problem had been understood at the microscopic level. The experiment of Kafkalidis and Tough demonstrated that a weak one dimensional nonuniformity in the flow field led to a dramatic departure between the observed behavior and the predictions of the Schwarz theory using the local uniformity approximation (LUA). The research presented in this thesis was undertaken to measure the dissipative states for thermal counterflow with a weak two dimensional nonuniformity. The experiment of Kafkalidis and Tough used a flow channel with a high aspect ratio. Such channels are known to exhibit only one state of superfluid turbulence. In this research the channel is circular in cross section and shows two distinct turbulent states (T-I and T-II). This experiment demonstrates that there is no difference in the excess dissipation for flows that are either converging or diverging. The T-I state is described by the same parameters as the T-I state in uniform channels. The turbulence exhibits front behavior at the transition between states. These conclusions are consistent with the LUA. The T-II state is at variance with the LUA, but is consistant with the results found in the Kafkalidis and Tough experiment.

  2. Superfluid turbulence in a nonuniform circular channel

    International Nuclear Information System (INIS)

    The excess dissipation due to the presence of quantized vorticity in flowing helium has been studied extensively. The success of the microscopic theory proposed by Schwarz in describing many properties of this dissipation led to a belief that the major aspects of the problem had been understood at the microscopic level. The experiment of Kafkalidis and Tough demonstrated that a weak one dimensional nonuniformity in the flow field led to a dramatic departure between the observed behavior and the predictions of the Schwarz theory using the local uniformity approximation (LUA). The research presented in this thesis was undertaken to measure the dissipative states for thermal counterflow with a weak two dimensional nonuniformity. The experiment of Kafkalidis and Tough used a flow channel with a high aspect ratio. Such channels are known to exhibit only one state of superfluid turbulence. In this research the channel is circular in cross section and shows two distinct turbulent states (T-I and T-II). This experiment demonstrates that there is no difference in the excess dissipation for flows that are either converging or diverging. The T-I state is described by the same parameters as the T-I state in uniform channels. The turbulence exhibits front behavior at the transition between states. These conclusions are consistent with the LUA. The T-II state is at variance with the LUA, but is consistent with the results found in the Kafkalidis and Tough experiment

  3. Circular SAR Optimization Imaging Method of Buildings

    Directory of Open Access Journals (Sweden)

    Wang Jian-feng

    2015-12-01

    Full Text Available The Circular Synthetic Aperture Radar (CSAR can obtain the entire scattering properties of targets because of its great ability of 360° observation. In this study, an optimal orientation of the CSAR imaging algorithm of buildings is proposed by applying a combination of coherent and incoherent processing techniques. FEKO software is used to construct the electromagnetic scattering modes and simulate the radar echo. The FEKO imaging results are compared with the isotropic scattering results. On comparison, the optimal azimuth coherent accumulation angle of CSAR imaging of buildings is obtained. Practically, the scattering directions of buildings are unknown; therefore, we divide the 360° echo of CSAR into many overlapped and few angle echoes corresponding to the sub-aperture and then perform an imaging procedure on each sub-aperture. Sub-aperture imaging results are applied to obtain the all-around image using incoherent fusion techniques. The polarimetry decomposition method is used to decompose the all-around image and further retrieve the edge information of buildings successfully. The proposed method is validated with P-band airborne CSAR data from Sichuan, China.

  4. Incipient Wigner localization in circular quantum dots

    Science.gov (United States)

    Ghosal, Amit; Güçlü, A. D.; Umrigar, C. J.; Ullmo, Denis; Baranger, Harold U.

    2007-08-01

    We study the development of electron-electron correlations in circular quantum dots as the density is decreased. We consider a wide range of both electron number, N⩽20 , and electron gas parameter, rs≲18 , using the diffusion quantum Monte Carlo technique. Features associated with correlation appear to develop very differently in quantum dots than in bulk. The main reason is that translational symmetry is necessarily broken in a dot, leading to density modulation and inhomogeneity. Electron-electron interactions act to enhance this modulation ultimately leading to localization. This process appears to be completely smooth and occurs over a wide range of density. Thus there is a broad regime of “incipient” Wigner crystallization in these quantum dots. Our specific conclusions are (i) the density develops sharp rings while the pair density shows both radial and angular inhomogeneity; (ii) the spin of the ground state is consistent with Hund’s (first) rule throughout our entire range of rs for all 4⩽N⩽20 ; (iii) the addition energy curve first becomes smoother as interactions strengthen—the mesoscopic fluctuations are damped by correlation—and then starts to show features characteristic of the classical addition energy; (iv) localization effects are stronger for a smaller number of electrons; (v) finally, the gap to certain spin excitations becomes small at the strong interaction (large rs ) side of our regime.

  5. LED downlights with non-circular spots

    Science.gov (United States)

    Parkyn, William A.; Pelka, David G.

    2005-09-01

    The ubiquitous downlight inhabits our ceilings by the millions. Hot, inefficient, and electrically wasteful, it is next in line for replacement by the latest high-brightness, high-efficacy white LEDs. The conventional downlight configuration of a large incandescent spotlight in a low-cost, ceiling-recessed metal can, represents the culmination of old technology, fated never to improve significantly. Incandescent downlights add greatly both to direct and indirect electrical consumption, with the lamps requiring relatively frequent replacement. The small size of LED emitters means small optical elements can produce much higher-quality beams than incandescent spotlight-lamps can produce. Herein we introduce compact high-luminosity LED downlights with lenses that deliver uniform illumination to delimited targets such as tables. One version utilizes circular lenses and micro-diffuser films to deliver square outputs. The other uses lenses cut to the target shape. In particular, one of these lenses is the first to offer a semicircular spot suitable for gambling tables.

  6. Administrative Circular No. 14 (Rev. 2)

    CERN Multimedia

    HR Department

    2007-01-01

    The HR Department wishes to draw the attention of members of the personnel to a number of amendments to Administrative Circular No. 14 (Rev. 2) entitled "Protection of members of the personnel against the financial consequences of illness, accident and disability" which came into force on 1st July 2006 (cf. Weekly Bulletin of 14 and 21 August 2006). Occupational Accident Declaration Form (HS50) https://cern.ch/service-procedures/AdminMan/Forms/HS50E.doc •\tIt must be completed within 10 working days of the date on which the accident occurred (§ 29.2.1), unless the person concerned is materially unable to meet this deadline. • The completed formula must be accompanied by a medical certificate giving details of any bodily injuries resulting from the accident (Annex 1, § 5). The medical certificate must be obtained from the doctor who has been consulted for that purpose. Benefits resulting from illnesses and accidents Medical treatment will cease to be reimbursed under ...

  7. Drops with non-circular footprints

    Science.gov (United States)

    Ravazzoli, Pablo D.; González, Alejandro G.; Diez, Javier A.

    2016-04-01

    In this paper we study the morphology of drops formed on partially wetting substrates, whose footprint is not circular. These drops are consequence of the breakup processes occurring in thin films when anisotropic contact line motions take place. The anisotropy is basically due to the hysteresis of the contact angle since there is a wetting process in some parts of the contact line, while a dewetting occurs in other parts. Here, we obtain a characteristic drop shape from the rupture of a long liquid filament sitting on a solid substrate. We analyze its shape and contact angles by means of goniometric and refractive techniques. We also find a non-trivial steady state solution for the drop shape within the long wave approximation (lubrication theory), and we compare most of its features with experimental data. This solution is presented both in Cartesian and polar coordinates, whose constants must be determined by a certain group of measured parameters. Besides, we obtain the dynamics of the drop generation from numerical simulations of the full Navier-Stokes equation, where we emulate the hysteretic effects with an appropriate spatial distribution of the static contact angle over the substrate.

  8. Drops with non-circular footprints

    CERN Document Server

    Ravazzoli, Pablo D; Diez, Javier A

    2015-01-01

    In this paper we study the morphology of drops formed on partially wetting substrates, whose footprint is not circular. This type of drops is a consequence of the breakup processes occurring in thin films when anisotropic contact line motions take place. The anisotropy is basically due to hysteresis effects of the contact angle since some parts of the contact line are wetting, while others are dewetting. Here, we obtain a peculiar drop shape from the rupture of a long liquid filament sitting on a solid substrate, and analyze its shape and contact angles by means of goniometric and refractive techniques. We also find a non--trivial steady state solution for the drop shape within the long wave approximation (lubrication theory), and compare most of its features with experimental data. This solution is presented both in Cartesian and polar coordinates, whose constants must be determined by a certain group of measured parameters. Besides, we obtain the dynamics of the drop generation from numerical simulations of...

  9. Circularly Polarized Light and Growth of Plants

    Science.gov (United States)

    Shibayev, Pavel; Pergolizzi, Robert

    2011-03-01

    The influence of linearly polarized light on the direction of plants growth has been recently demonstrated. The state of circularly polarized (CP) light can also change when it is reflected from the surface of leaves and stems. However, the role of light handedness in the development of plants and CP light interaction with the complexes of chlorophyll molecules have still not been studied enough. In this work, the role of left CP light in the accelerated growth of lentil and pea plants is revealed and studied. The mechanism of such an enhancement is discussed in terms of the model considering transmission, absorption, and scattering of CP light on micro and macro levels of leaf organization. Theoretical modeling of light interaction with the interior of the leaf was conducted for a number of recently proposed models of organization of chlorophyll molecules and chloroplasts. All the calculations were performed by employing a 4x4 matrix method in solving Maxwell equations. It is shown that left-handed chiral organization of chlorophyll molecules can greatly enhance the absorption of light and therefore lead to the enhanced growth of the whole plant under CP light.

  10. Circularly Polarized Broadband RFID Microstrip Tag Antenna

    Directory of Open Access Journals (Sweden)

    B. Rajini

    2014-04-01

    Full Text Available In recent years, the application of radio frequency identification (RFID operating in the ultra-high frequency (UHF band (860-960MHz are expanding exponentially, due to the advantages such as long reading distance, high data transfer rate, and small tag size. So the design of a CP tag antenna with broadband characteristic is presently one of the most challenging topics. This project presents a square patch passive RFID tag antenna designed for UHF band. To achieve compact size broadband and circular polarization (CP radiation, the square patch is embedded with a cross slot, while an L-shaped open-end microstrip line coupled to the patch. By selecting an appropriate length for the microstrip line and its coupling distance with the radiating element, easy control on the input impedance of the designed tag antenna which leads to excellent impedance matching is achieved. The measured 10-dB return-loss bandwidth of the tag antenna is 27MHz (from 901–928 MHz.

  11. On Introducing Asymmetry into Circular Distributions

    Directory of Open Access Journals (Sweden)

    Dale Umbach

    2012-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} We give a brief history of the results which led to the introduction of asymmetry into symmetric circular distributions. This is followed by the presentation of another method of introducing asymmetry. Some properties of the induced distributions are studied. Finally, this new distribution is shown to be a reasonable fit to the Jander ant data as presented in Fisher (1993.

  12. TRIPLET CIRCULAR HOUGH TRANSFORM FOR CIRCLE DETECTION

    Institute of Scientific and Technical Information of China (English)

    LuoDaisheng; HeXiaohai; 等

    2002-01-01

    A new method,triplet circular Hough transform,is proposed for circle detection in image processing and pattern recognition.In the method,a curve in an image is first detected.Next,a sequence of three points on the curve are selected.a sequence of parameters(a,b,r)corresponding to the three points are calculated by solving the circle equation of the curve,and two 2-D accumulators A(a,b)and R(a,b)are accumulated with 1 and r,respectively,Then the parameters{(a,b,r)}of the circles fitting the curve are determined from A(a,b)and R(a,b) by searching for the local maximum over A(a,b).Because no computation loops over center(a,b) and/or radius r are needed,the method is faster than the basic and directional gradient methods It needs also much smaller memory for accumulation.

  13. A novel broadband circularly polarised monopole antenna

    Science.gov (United States)

    Kang, Ding; Cheng, Gao; Tongbin, Yu; Dexin, Qu

    2015-11-01

    A novel broadband circularly polarised (CP) monopole antenna is designed and implemented in this article. The antenna consists of a radiating patch that is composed of an annular-ring linked by a square ring over the corner and a modified ground plane. The broadband property is achieved based on a novel monopole structure that is connected by two perturbed loops, so the CP wave is generated due to the perturbation. Besides, by cutting a rectangular slit and embedding a vertical stub on the ground plane, the impedance and axial-ratio (AR) bandwidths can be greatly enhanced. The measured results reveal that the proposed monopole antenna has an impedance bandwidth of 4.575 GHz from 2.3 to 6.85 GHz, reaching the particularly broad bandwidth of 99.5%. Furthermore, a wide 3-dB AR bandwidth of 34.6% (1.53 GHz, 3.65-5.18 GHz) centred at 4.42 GHz is achieved. The radiation characteristics of the designed antenna are also presented.

  14. Resonance and coupling effects in circular accelerators

    International Nuclear Information System (INIS)

    This thesis deals with a general theory for the description of resonance and coupling effects in circular particle accelerators. The theory is mainly applied to the proposed proton accumulator ring IKOR in West Germany and to an electron storage ring which is characteristic of existing synchrotron radiation facilities (PAMPUS; this project has since been dismissed by the Dutch government). In chapter 1 the author expands the general Hamilton function for the description of the relativistic particle motion in a time-dependent magnetic field and a HF accelerating electric field (in order to study transverse-longitudinal coupling effects) as well as for the motion in a time-independent magnetic field without acceleration (to study transverse coupling effects). The linear transverse motion is discussed in chapter 2. Analytical formulae for the so-called Twiss parameters are derived from the linear Hamilton theory. The simultaneous treatment of the betatron and synchrotron motion is developed in chapter 3 and a theory for the description of the one-dimensional non-linear betatron motion is elaborated in chapter 4. The two-dimensional non-linear betatron resonances are treated in chapter 5. The description of these resonances can be reduced rather simply to a one-dimensional problem and are treated by examination of trajectories in a phase plane. (Auth.)

  15. The Exact Solution for Linear Thermoelastic Axisymmetric Deformations of Generally Laminated Circular Cylindrical Shells

    Science.gov (United States)

    Nemeth, Michael P.; Schultz, Marc R.

    2012-01-01

    A detailed exact solution is presented for laminated-composite circular cylinders with general wall construction and that undergo axisymmetric deformations. The overall solution is formulated in a general, systematic way and is based on the solution of a single fourth-order, nonhomogeneous ordinary differential equation with constant coefficients in which the radial displacement is the dependent variable. Moreover, the effects of general anisotropy are included and positive-definiteness of the strain energy is used to define uniquely the form of the basis functions spanning the solution space of the ordinary differential equation. Loading conditions are considered that include axisymmetric edge loads, surface tractions, and temperature fields. Likewise, all possible axisymmetric boundary conditions are considered. Results are presented for five examples that demonstrate a wide range of behavior for specially orthotropic and fully anisotropic cylinders.

  16. Micropolarity-Ramification of Laminar/Turbulent Circular-Plane-Jet

    CERN Document Server

    Siddiqui, Abuzar Abid

    2016-01-01

    In the present work we formulated the boundary-value-problem, comprising partial differential equations (PDEs) of steady flow for laminar/turbulent circular jet of a micropolar fluid. A new boundary layer-similarity transformation/solution was derived which is valid not only for the Newtonian fluids but also for the micropolar fluids. Through this transformation PDEs are transformed into the ordinary differential equations (ODEs). These ODEs were solved numerically by the finite-difference method. The obtained results were compared with existing results [9] for the Newtonian fluids. The comparison was favourable. The micropolarity influences were highlighted in the present work. The axial-fluid-speed and normal stress-component decreases but radial-fluid-speed, microspin and one of the normal stress-component increase as the micropolarity effect enhances. The fluid-speed, microspin, shear stresses, normal stresses and couple stresses are dominant in the vicinity of the jet-source whereas they all vanish as fa...

  17. Curved-Line Cutting Using a Flexible Circular Saw

    Science.gov (United States)

    Yamada, Yohei; Osumi, Nobuyuki; Takasugi, Akio; Sasahara, Hiroyuki

    We propose a flexible circular saw for high-speed cutting of curved lines in carbon fiber-reinforced plastic (CFRP). A conventional circular saw is appropriate for straight line cutting, but it cannot be applied to curved line cutting because of the interference between the saw body and the machined surface. To eliminate this problem, the flexible circular saw is deflected into a bowl shape by circular forced displacement, and the cross-section of the saw becomes a circular arc. A curved line can be cut by the bowl-like-deflection. The deflection shape is very important to realize the curved-line cutting without interference. We investigated the deflection of the flexible circular saw by a finite element method (FEM) analysis. Suitable slit shapes for the saw body are also proposed, based on the FEM results regarding stress in the saw body, the minimum radius of curvature, and the effects of cutting force and centrifugal force and eigenvalue. We also conducted a curved-line cutting test on a CFRP plate, and we found that the flexible circular saw can cut curved lines with high accuracy and high speed without interference between the saw body and the machined surface.

  18. Inversion of the circular averages transform using the Funk transform

    International Nuclear Information System (INIS)

    The integral of a function defined on the half-plane along the semi-circles centered on the boundary of the half-plane is known as the circular averages transform. Circular averages transform arises in many tomographic image reconstruction problems. In particular, in synthetic aperture radar (SAR) when the transmitting and receiving antennas are colocated, the received signal is modeled as the integral of the ground reflectivity function of the illuminated scene over the intersection of spheres centered at the antenna location and the surface topography. When the surface topography is flat the received signal becomes the circular averages transform of the ground reflectivity function. Thus, SAR image formation requires inversion of the circular averages transform. Apart from SAR, circular averages transform also arises in thermo-acoustic tomography and sonar inverse problems. In this paper, we present a new inversion method for the circular averages transform using the Funk transform. For a function defined on the unit sphere, its Funk transform is given by the integrals of the function along the great circles. We used hyperbolic geometry to establish a diffeomorphism between the circular averages transform, hyperbolic x-ray and Funk transforms. The method is exact and numerically efficient when fast Fourier transforms over the sphere are used. We present numerical simulations to demonstrate the performance of the inversion method. Dedicated to Dennis Healy, a friend of Applied Mathematics and Engineering

  19. Sources of varieties and quality of circular Fructus Ligustri Lucidi.

    Science.gov (United States)

    Li, Yan-Peng; Wang, Si-Jia; Zang, Yi-Mei; Hu, Zhong-Sheng; Liu, Chun-Sheng

    2016-03-01

    This study aimed to trace sources and quantitatively analyze the specnuezhenide content of circular Fructus Ligustri Lucidi for clinical use. Different specifications of Fructus Ligustri Lucidi were identified using DNA barcoding technology and the specnuezhenide content was analyzed by High Performance Liquid Chromatography (HPLC). The ITS sequence of circular Fructus Ligustri Lucidi was identical to that of standard privet, which was determined through botanical identification. ITS sequence similarity between circular Fructus Ligustri Lucidi and Fructus Ligustri Lucidi which was registered in NCBI ranged from 99.5% to 100%. The sequences of circular and other Fructus Ligustri Lucidi were clustered in a Neighbor-Joining tree with bootstrap value of 95, and these sequences could be distinguished from adulterants. Conforming to pharmacopoeia standard, the average specnuezhenide content of circular Fructus Ligustri Lucidi was higher than that of chicken waist Fructus Ligustri Lucidi. Circular Fructus Ligustri Lucidi derived from Ligustrum lucidum Ait. and the specnuezhenide content was higher in circular Fructus Ligustri Lucidi than that in chicken waist Fructus Ligustri Lucidi. PMID:27025372

  20. Cutting force prediction for circular end milling process

    Institute of Scientific and Technical Information of China (English)

    Wu Baohai; Yan Xue; Luo Ming; Gao Ge

    2013-01-01

    A deduced cutting force prediction model for circular end milling process is presented in this paper.Traditional researches on cutting force model usually focus on linear milling process which does not meet other cutting conditions,especially for circular milling process.This paper presents an improved cutting force model for circular end milling process based on the typical linear milling force model.The curvature effects of tool path on chip thickness as well as entry and exit angles are analyzed,and the cutting force model of linear milling process is then corrected to fit circular end milling processes.Instantaneous cutting forces during circular end milling process are predicted according to the proposed model.The deduced cutting force model can be used for both linear and circular end milling processes.Finally,circular end milling experiments with constant and variable radial depth were carried out to verify the availability of the proposed method.Experiment results show that measured results and simulated results corresponds well with each other.

  1. Iowa Intensive Archaeological Survey

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This shape file contains intensive level archaeological survey areas for the state of Iowa. All intensive Phase I surveys that are submitted to the State Historic...

  2. Product Quality, Advertising Intensity and Market Size

    OpenAIRE

    Bing Han; Hayley Chouinard

    2013-01-01

    We develop a model of product differentiation in which firms strategically compete in product quality and advertising intensity. Consumers face a trade-off between higher quality goods and price. Increased competition may lead to higher or lower quality products. Consumers always benefit from more competition as a reduction in price offsets reduced quality.

  3. Rainfed intensive crop systems

    DEFF Research Database (Denmark)

    Olesen, Jørgen E

    2014-01-01

    This chapter focuses on the importance of intensive cropping systems in contributing to the world supply of food and feed. The impact of climate change on intensive crop production systems is also discussed.......This chapter focuses on the importance of intensive cropping systems in contributing to the world supply of food and feed. The impact of climate change on intensive crop production systems is also discussed....

  4. Intensity modulated proton therapy

    OpenAIRE

    Kooy, H. M.; Grassberger, C

    2015-01-01

    Intensity modulated proton therapy (IMPT) implies the electromagnetic spatial control of well-circumscribed “pencil beams” of protons of variable energy and intensity. Proton pencil beams take advantage of the charged-particle Bragg peak—the characteristic peak of dose at the end of range—combined with the modulation of pencil beam variables to create target-local modulations in dose that achieves the dose objectives. IMPT improves on X-ray intensity modulated beams (intensity modulated radio...

  5. Anisotropic elliptical dichroism and influence of imperfection of circular polarization upon anisotropic circular dichroism

    International Nuclear Information System (INIS)

    In spite of the importance of anisotropic circular dichroism, in practice, it is difficult to get rid of the artifacts that arise from the imperfection of the circular polarization. Undesirable linear dichroism, interference of two orthogonal polarization states, and linear birefringence prevent us from making accurate measurements. We propose a theoretical method for evaluating the contributions of the first two, which are thought to be the main artifacts when specimens are not thick enough. Using the time-dependent perturbation theory and taking into account the direction of light propagation toward an orientationally fixed molecule, we formulated the transition probability of systems perturbed by arbitrarily polarized light and the absorption difference associated with two kinds of polarized light. We also formulated, as an extension of the dissymmetry factor of circular dichroism, a newly defined dissymmetry factor associated with two arbitrary polarization states. Furthermore, we considered a mixed-state of photon ensemble in which polarization states distribute at a certain width around a certain average. Although the purity of polarization and ellipticity does not correspond immediately, by considering the mixed state it is possible to treat them consistently. We used quantum statistical mechanics to describe the absorption difference for two kinds of photon ensembles and applied the consequent formula to examine the reported experimental results of single-molecule chiroptical responses under discussion in the recent past. The artifacts are theoretically suggested to be sensitive to the incident direction of elliptically polarized light and to the oriented systems, the ellipticity, and the orientation of ellipse. The mixed state has little, if any, effect when the polarization state distribution is narrow

  6. Anisotropic elliptical dichroism and influence of imperfection of circular polarization upon anisotropic circular dichroism

    Science.gov (United States)

    Wakabayashi, Masamitsu; Yokojima, Satoshi; Fukaminato, Tuyoshi; Ohtani, Hiroyuki; Nakamura, Shinichiro

    2015-04-01

    In spite of the importance of anisotropic circular dichroism, in practice, it is difficult to get rid of the artifacts that arise from the imperfection of the circular polarization. Undesirable linear dichroism, interference of two orthogonal polarization states, and linear birefringence prevent us from making accurate measurements. We propose a theoretical method for evaluating the contributions of the first two, which are thought to be the main artifacts when specimens are not thick enough. Using the time-dependent perturbation theory and taking into account the direction of light propagation toward an orientationally fixed molecule, we formulated the transition probability of systems perturbed by arbitrarily polarized light and the absorption difference associated with two kinds of polarized light. We also formulated, as an extension of the dissymmetry factor of circular dichroism, a newly defined dissymmetry factor associated with two arbitrary polarization states. Furthermore, we considered a mixed-state of photon ensemble in which polarization states distribute at a certain width around a certain average. Although the purity of polarization and ellipticity does not correspond immediately, by considering the mixed state it is possible to treat them consistently. We used quantum statistical mechanics to describe the absorption difference for two kinds of photon ensembles and applied the consequent formula to examine the reported experimental results of single-molecule chiroptical responses under discussion in the recent past. The artifacts are theoretically suggested to be sensitive to the incident direction of elliptically polarized light and to the oriented systems, the ellipticity, and the orientation of ellipse. The mixed state has little, if any, effect when the polarization state distribution is narrow.

  7. Anisotropic elliptical dichroism and influence of imperfection of circular polarization upon anisotropic circular dichroism

    Energy Technology Data Exchange (ETDEWEB)

    Wakabayashi, Masamitsu [Department of Biomolecular Engineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8501 (Japan); RIKEN, Research Cluster for Innovation, Nakamura Lab, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Yokojima, Satoshi, E-mail: yokojima@toyaku.ac.jp [Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachiouji-shi, Tokyo 192-0392 (Japan); RIKEN, Research Cluster for Innovation, Nakamura Lab, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Fukaminato, Tuyoshi [Research Institute for Electronic Science, Hokkaido University, N20, W10, Kita-ku, Sapporo 001-0020 (Japan); PRESTO, Japan Science and Technology Agency (JST), Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan); Ohtani, Hiroyuki [Department of Biomolecular Engineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8501 (Japan); Nakamura, Shinichiro, E-mail: snakamura@riken.jp [RIKEN, Research Cluster for Innovation, Nakamura Lab, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

    2015-04-21

    In spite of the importance of anisotropic circular dichroism, in practice, it is difficult to get rid of the artifacts that arise from the imperfection of the circular polarization. Undesirable linear dichroism, interference of two orthogonal polarization states, and linear birefringence prevent us from making accurate measurements. We propose a theoretical method for evaluating the contributions of the first two, which are thought to be the main artifacts when specimens are not thick enough. Using the time-dependent perturbation theory and taking into account the direction of light propagation toward an orientationally fixed molecule, we formulated the transition probability of systems perturbed by arbitrarily polarized light and the absorption difference associated with two kinds of polarized light. We also formulated, as an extension of the dissymmetry factor of circular dichroism, a newly defined dissymmetry factor associated with two arbitrary polarization states. Furthermore, we considered a mixed-state of photon ensemble in which polarization states distribute at a certain width around a certain average. Although the purity of polarization and ellipticity does not correspond immediately, by considering the mixed state it is possible to treat them consistently. We used quantum statistical mechanics to describe the absorption difference for two kinds of photon ensembles and applied the consequent formula to examine the reported experimental results of single-molecule chiroptical responses under discussion in the recent past. The artifacts are theoretically suggested to be sensitive to the incident direction of elliptically polarized light and to the oriented systems, the ellipticity, and the orientation of ellipse. The mixed state has little, if any, effect when the polarization state distribution is narrow.

  8. Circular RNA oligonucleotides. Synthesis, nucleic acid binding properties, and a comparison with circular DNAs.

    Science.gov (United States)

    Wang, S; Kool, E T

    1994-06-25

    We report the synthesis and nucleic acid binding properties of two cyclic RNA oligonucleotides designed to bind single-stranded nucleic acids by pyr.pur.pyr-type triple helix formation. The circular RNAs are 34 nucleotides in size and were cyclized using a template-directed nonenzymatic ligation. To ensure isomeric 3'-5' purity in the ligation reaction, one nucleotide at the ligation site is a 2'-deoxyribose. One circle (1) is complementary to the sequence 5'-A12, and the second (2) is complementary to 5'-AAGAAAGAAAAG. Results of thermal denaturation experiments and mixing studies show that both circles bind complementary single-stranded DNA or RNA substrates by triple helix formation, in which two domains in a pyrimidine-rich circle sandwich a central purine-rich substrate. The affinities of these circles with their purine complements are much higher than the affinities of either the linear precursors or simple Watson-Crick DNA complements. For example, circle 1 binds rA12 (pH 7.0, 10 mM MgCl2, 100 mM NaCl) with a Tm of 48 degrees C and a Kd (37 degrees C) of 4.1 x 10(-9) M, while the linear precursor of the circle binds with a Tm of 34 degrees C and a Kd of 1.2 x 10(-6) M. The complexes of circle 2 are pH-dependent, as expected for triple helical complexes involving C(+)G.C triads, and mixing plots for both circles reveal one-to-one stoichiometry of binding either to RNA or DNA substrates. Comparison of circular RNAs with previously synthesized circular DNA oligonucleotides of the same sequence reveals similar behavior in the binding of DNA, but strikingly different behavior in the binding of RNA. The cyclic DNAs show high DNA-binding selectivity, giving relatively weaker duplex-type binding with complementary RNAs. The relative order of thermodynamic stability for the four types of triplex studied here is found to be DDD > RRR > RDR > DRD. The results are discussed in the context of recent reports of strong triplex dependence on RNA versus DNA backbones. Triplex

  9. Plastic welding techniques based on torsional and circular motion.

    Science.gov (United States)

    Kising, J

    2001-05-01

    The torsion ultrasonic welding process and the frequency decoupled circular friction process at low frequencies deliver low particle production. In addition, the even, circular movement of the circular welding process over the whole seam area and the freely selectable frequency open up applications in the medical field that cannot be achieved, or can only be achieved with difficulty, by traditional welding processes. The processes are fast and can be process controlled to a fine degree with a facility to be integrated into automation lines. PMID:11521653

  10. Mathematical model for light scanning system based on circular laser

    Institute of Scientific and Technical Information of China (English)

    Peiquan Xu; Shun Yao; Fenggui Lu; Xinhua Tang; Wei Zhang

    2005-01-01

    A novel light scanning system based on circular laser trajectory for welding robot is developed. With the help of image processing technique, intelligent laser welding could be realized. According to laser triangulation algorithm and Scheimpflug condition, mathematical model for circular laser vision is built.This scanning system projects circular laser onto welded seams and recovers the depth of the welded seams,escapes from shortcomings of less information, explains ambiguity and single tracking direction inherent in "spot" or "line" type laser trajectory. Three-dimensional (3D) model for welded seams could be recognized after depth recovery. The imaging error is investigated also.

  11. Administrative Circular No. 26 (Rev. 9) – Recognition of Merit

    CERN Multimedia

    2012-01-01

    Administrative Circular No. 26 (Rev. 9) entitled "Recognition of Merit”, approved by the Director-General following discussion in the Standing Concertation Committee meeting on 27 September 2011 is available on the intranet site of the Human Resources Department: https://cern.ch/hr-docs/admincirc/admincirc.asp The circular was above all revised in order to integrate the new CERN Competency Model into the annual procedure of performance appraisal. It cancels and replaces Administrative Circular No. 26 (Rev. 8) entitled "Recognition of merit” of September 2008. Department Head Office HR Department

  12. A New Wideband Circularly Polarized Dielectric Resonator Antenna

    OpenAIRE

    M Khalily; Kamarudin, M. R.; Mokayef, M.; Sh. Danesh; Ghahferokhi, S. E. A.

    2014-01-01

    A wideband and compact circularly polarized (CP) C-shaped dielectric resonator antenna (DRA) is presented. The proposed C-shaped DR is excited by a simple stripe line connected to a coplanar waveguide (CPW) feeding line. The C-shaped DRA is circularly polarized with 19% axial ratio (AR) bandwidth. It is found that the CP bandwidth can be expanded by using a narrow short circuit strip. The final design achieves CP with 50% AR bandwidth. The proposed circularly polarized DRA (CPDRA) with good r...

  13. Absorbed Power Minimization in Cellular Users with Circular Antenna Arrays

    Science.gov (United States)

    Christofilakis, Vasilis; Votis, Constantinos; Tatsis, Giorgos; Raptis, Vasilis; Kostarakis, Panos

    2010-01-01

    Nowadays electromagnetic pollution of non ionizing radiation generated by cellular phones concerns millions of people. In this paper the use of circular antenna array as a means of minimizing the absorbed power by cellular phone users is introduced. In particular, the different characteristics of radiation patterns produced by a helical conventional antenna used in mobile phones operating at 900 MHz and those produced by a circular antenna array, hypothetically used in the same mobile phones, are in detail examined. Furthermore, the percentage of decrement of the power absorbed in the head as a function of direction of arrival is estimated for the circular antenna array.

  14. Helically assembled π-conjugated polymers with circularly polarized luminescence

    International Nuclear Information System (INIS)

    We review the recent progress in the field of helically assembled π-conjugated polymers, focusing on aromatic conjugated polymers with interchain helical π-stacking that exhibit circularly polarized luminescence (CPL). In Part 1, we discuss optically active polymers with white-colored CPL and the amplification of the circular polarization through liquid crystallinity. In Part 2, we focus on the stimuli-responsive CPL that results from changes in the conformation and aggregation state of π-conjugated molecules and polymers. In Part 3, we discuss the self-assembly of achiral cationic π-conjugated polymers into circularly polarized luminescent supramolecular nanostructures with the aid of other chiral molecules. (review)

  15. Administrative Circular No. 26 (Rev. 7) – May 2007

    CERN Multimedia

    HR Department

    2007-01-01

    Recognition of Merit of Staff Members Administrative Circular No. 26 (Rev. 7) is now available on the intranet site of the Human Resources Department. This circular cancels and replaces Administrative Circular No. 26 (Rev. 6) - Procedures governing the career development of staff members. Copies will shortly be available in Departmental secretariats. If you require any additional information on the new staff-member merit assessment and recognition system, you may consult the FAQ, which has been available on the Human Resources Department intranet site since February 2007. Human Resources Department Tel. 78003

  16. Circular neighbor-balanced designs universally optimal for total effects

    Institute of Scientific and Technical Information of China (English)

    Ling-yau; CHAN

    2007-01-01

    In many experiments, the performance of a subject may be affected by some previous treatments applied to it apart from the current treatment. This motivates the studies of the residual effects of the treatments in a block design. This paper shows that a circular block design neighbor-balanced at distances up toγ≤k - 1, where k is the block size, is universally optimal for total effects under the linear models containing the neighbor effects at distances up toγamong the class of all circular binary block designs. Some combinatorial approaches to constructing these circular block designs neighbor-balanced at distances up to k - 1 are provided.

  17. THE SPATIAL DISTRIBUTION AND MOMENTS OF CIRCULAR FREELY JOINTED CHAIN

    Institute of Scientific and Technical Information of China (English)

    HAO Minghong

    1991-01-01

    The spatial distribution function and second moments of circular freely jointed chain are derived based on an analytical method. The circular Gauss chain, which is simple for long chains, is compared with the circular freely jointed chain, which is exact for short chains. It is shown that the Gauss chain model predicts a more compact configurational distribution than the exact freely jointed chain. The two chain models, however, become closer to each other when the chain length increases.It is found that the difference of the mean square radius of gyration calculated with these two chain models is a constant, independent of the chain length.

  18. Circular neighbor-balanced designs universally optimal for total effects

    Institute of Scientific and Technical Information of China (English)

    Ming-yao AI; Gen-nian GE; Ling-yau CHAN

    2007-01-01

    In many experiments, the performance of a subject may be affected by some previous treatments applied to it apart from the current treatment. This motivates the studies of the residual effects of the treatments in a block design. This paper shows that a circular block design neighborbalanced at distances up to γ≤ k- 1, where k is the block size, is universally optimal for total effects under the linear models containing the neighbor effects at distances up to γ among the class of all circular binary block designs. Some combinatorial approaches to constructing these circular block designs neighbor-balanced at distances up to k - 1 are provided.

  19. Circularly polarized light emission from semiconductor planar chiral nanostructures.

    Science.gov (United States)

    Konishi, Kuniaki; Nomura, Masahiro; Kumagai, Naoto; Iwamoto, Satoshi; Arakawa, Yasuhiko; Kuwata-Gonokami, Makoto

    2011-02-01

    We demonstrate circularly polarized light emission from InAs quantum dots embedded in the waveguide region of a GaAs-based chiral nanostructure. The observed phenomenon originates due to a strong imbalance between left- and right-circularly polarized components of the vacuum field and results in a degree of polarization as high as 26% at room temperature. A strong circular anisotropy of the vacuum field modes inside the chiral nanostructure is visualized using numerical simulation. The results of the simulation agree well with experimental results. PMID:21405435

  20. Computational Investigation of Dipole Traps Formed by the Projection of Diffraction Patterns from a Circular Aperture

    Science.gov (United States)

    Gillen, Glen D.; Gillen-Christandl, Katharina

    2011-05-01

    Previously we have shown that laser light incident upon a circular diffracting aperture produces intensity distributions suitable for either red-detuned (RDT) or blue-detuned (BDT) optical dipole traps for cold neutral atoms. Typically, the calculated traps are located within a millimeter of the diffracting aperture, which requires the aperture to be located inside of the vacuum chamber. Using a combination of scalar diffraction theory and beam propagation techniques, a mathematical model has been developed to project the diffraction pattern away from the aperture. Projected intensity distributions allow for the diffracting aperture and optics to be located outside of the vacuum chamber. We will present calculations which show that the properties of the RDT and BDT sites are not only maintained through the projection, but also can be manipulated using a simple single-lens optical system. Work supported by the NSF Grant No. PHY-0855524.

  1. A study of aliphatic amino acids using simulated vibrational circular dichroism and Raman optical activity spectra

    CERN Document Server

    Ganesan, Aravindhan; Wang, Feng

    2013-01-01

    Vibrational optical activity (VOA) spectra, such as vibrational circular dichroism (VCD) and Raman optical activity (ROA) spectra, of aliphatic amino acids are simulated using density functional theory (DFT) methods in both gas phase (neutral form) and solution (zwitterionic form), together with their respective infrared (IR) and Raman spectra of the amino acids. The DFT models, which are validated by excellent agreements with the available experimental Raman and ROA spectra of alanine in solution, are employed to study other aliphatic amino acids. The inferred (IR) intensive region (below 2000 cm-1) reveals the signature of alkyl side chains, whereas the Raman intensive region (above 3000 cm-1) contains the information of the functional groups in the amino acids. Furthermore, the chiral carbons of the amino acids (except for glycine) dominate the VCD and ROA spectra in the gas phase, but the methyl group vibrations produce stronger VCD and ROA signals in solution. The C-H related asymmetric vibrations domina...

  2. Vibrational circular dichroism of tetraphenylporphyrin in peptide complexes? A computational study.

    Science.gov (United States)

    Bour, P; Záruba, K; Urbanová, M; Setnicka, V; Matejka, P; Fiedler, Z; Král, V; Volka, K

    2000-05-01

    The Raman and absorption spectra of tetraphenylporphyrin (TPP) were calculated and compared to experiment. The computation was based on the harmonic molecular force field and electric tensors obtained ab initio at the BPW91/6-31G* level. Good agreement was found between experimental and calculated frequencies and intensities. In order to estimate whether induced optical activity in chiral complexes interferes with the signal of peptide vibrations, the vibrational circular dichroism (VCD) spectra of TPP were simulated. The magnetic field perturbation theory (MFP) and the gauge-invariant atomic orbitals (GIAO) were used for the simulation. Such spectra were compared to theoretical VCD intensities of a model tripeptide as well to experimental spectra of a complex of the peptide and tetrakis(p-sulfonatophenyl)porphyrin (TSPP). No significant contribution to VCD signal from the TPP residue was found in experimental spectra. Thus, possible peptide conformational changes occurring during the complexation can be monitored directly in the amide I frequency region. PMID:10790189

  3. Hole dynamics and spin currents after ionization in strong circularly polarized laser fields

    International Nuclear Information System (INIS)

    We apply the time-dependent analytical R-matrix theory to develop a movie of hole motion in a Kr atom upon ionization by strong circularly polarized field. We find rich hole dynamics, ranging from rotation to swinging motion. The motion of the hole depends on the final energy and the spin of the photoelectron and can be controlled by the laser frequency and intensity. Crucially, hole rotation is a purely non-adiabatic effect, completely missing in the framework of quasistatic (adiabatic) tunneling theories. We explore the possibility to use hole rotation as a clock for measuring ionization time. Analyzing the relationship between the relative phases in different ionization channels we show that in the case of short-range electron-core interaction the hole is always initially aligned along the instantaneous direction of the laser field, signifying zero delays in ionization. Finally, we show that strong-field ionization in circular fields creates spin currents (i.e. different flow of spin-up and spin-down density in space) in the ions. This phenomenon is intimately related to the production of spin-polarized electrons in strong laser fields Barth and Smirnova (2013 Phys. Rev. A 88 013401). We demonstrate that rich spin dynamics of electrons and holes produced during strong field ionization can occur in typical experimental conditions and does not require relativistic intensities or strong magnetic fields. (paper)

  4. Gamma ray vortices from nonlinear inverse Compton scattering of circularly polarized light

    CERN Document Server

    Taira, Yoshitaka; Katoh, Masahiro

    2016-01-01

    Inverse Compton scattering (ICS) is an elemental radiation process that produces high-energy photons both in nature and in the laboratory. Non-linear ICS is a process in which multiple photons are converted to a single high-energy photon. Here, we theoretically show that the photon produced by non-linear ICS of circularly polarized photons is a vortex, which means that it possesses a helical wave front and carries orbital angular momentum. Our work explains a recent experimental result regarding non-linear Compton scattering that clearly shows an annular intensity distribution as a remarkable feature of a vortex beam. Our work implies that gamma ray vortices should be produced in various situations in astrophysics in which high-energy electrons and intense circularly polarized light fields coexist. They should play a critical role in stellar nucleosynthesis. Non-linear ICS is the most promising radiation process for realizing a gamma ray vortex source based on currently available laser and accelerator technol...

  5. Ionization and excitation of the excited hydrogen atom in strong circularly polarized laser fields

    CERN Document Server

    Bauer, J H; O'Mahony, Patrick F; Piraux, Bernard; Warda, K

    2014-01-01

    In the recent work of Herath et al. [Phys. Rev. Lett. 109, 043004 (2012)] the first experimental observation of a dependence of strong-field ionization rate on the sign of the magnetic quantum number m (of the initial bound state (n,l.m)) was reported. The experiment with nearly circularly polarized light could not distinguish which sign of m favors faster ionization. We perform ab initio calculations for the hydrogen atom initially in one of the four bound sub states with the principal quantum number n=2 and irradiated by a short circularly polarized laser pulse of 800nm. In the intensity range of 10^12 to 10^13 Watts/cm^2 excited bound states play a very important role, but also up to some 10^15 Watts/cm^2 they can not be neglected in a full description of the laser-atom interaction. We explore the region that with increasing intensity switches from multiphoton to over the barrrier ionization and we find unlike in tunneling-type theories, that the ratio of ionization rates for electrons initially counter-ro...

  6. Vibrational Circular Dichroism Spectra for Large Molecules through Molecules-in-Molecules Fragment-Based Approach.

    Science.gov (United States)

    Jose, K V Jovan; Beckett, Daniel; Raghavachari, Krishnan

    2015-09-01

    We present the first implementation of the vibrational circular dichroism (VCD) spectrum of large molecules through the Molecules-in-Molecules (MIM) fragment-based method. An efficient projection of the relevant higher energy derivatives from smaller fragments to the parent molecule enables the extension of the MIM method for the evaluation of VCD spectra (MIM-VCD). The overlapping primary subsystems in this work are constructed from interacting fragments using a number-based scheme and the dangling bonds are saturated with link hydrogen atoms. Independent fragment calculations are performed to evaluate the energies, Hessian matrix, atomic polar tensor (APT), and the atomic axial tensor (AAT). Subsequently, the link atom tensor components are projected back onto the corresponding host and supporting atoms through the Jacobian projection method, as in the ONIOM approach. In the two-layer model, the long-range interactions between fragments are accounted for using a less computationally intensive lower level of theory. The performance of the MIM model is calibrated on the d- and l-enantiomers of 10 carbohydrate benchmark molecules, with strong intramolecular interactions. The vibrational frequencies and VCD intensities are accurately reproduced relative to the full, unfragmented, results for these systems. In addition, the MIM-VCD method is employed to predict the VCD spectra of perhydrotriphenylene and cryptophane-A, yielding spectra in agreement with experiment. The accuracy and performance of the benchmark systems validate the MIM-VCD model for exploring vibrational circular dichroism spectra of large molecules. PMID:26575919

  7. Locating irregularly shaped clusters of infection intensity

    Directory of Open Access Journals (Sweden)

    Niko Yiannakoulias

    2010-05-01

    Full Text Available Patterns of disease may take on irregular geographic shapes, especially when features of the physical environment influence risk. Identifying these patterns can be important for planning, and also identifying new environmental or social factors associated with high or low risk of illness. Until recently, cluster detection methods were limited in their ability to detect irregular spatial patterns, and limited to finding clusters that were roughly circular in shape. This approach has less power to detect irregularly-shaped, yet important spatial anomalies, particularly at high spatial resolutions. We employ a new method of finding irregularly-shaped spatial clusters at micro-geographical scales using both simulated and real data on Schistosoma mansoni and hookworm infection intensities. This method, which we refer to as the “greedy growth scan”, is a modification of the spatial scan method for cluster detection. Real data are based on samples of hookworm and S. mansoni from Kitengei, Makueni district, Kenya. Our analysis of simulated data shows how methods able to find irregular shapes are more likely to identify clusters along rivers than methods constrained to fixed geometries. Our analysis of infection intensity identifies two small areas within the study region in which infection intensity is elevated, possibly due to local features of the physical or social environment. Collectively, our results show that the “greedy growth scan” is a suitable method for exploratory geographical analysis of infection intensity data when irregular shapes are suspected, especially at micro-geographical scales.

  8. Circular RNAs and systemic lupus erythematosus.

    Science.gov (United States)

    Li, Lian-Ju; Huang, Qing; Pan, Hai-Feng; Ye, Dong-Qing

    2016-08-15

    Circular RNAs (circRNAs) are a large class of noncoding RNAs that form covalently closed RNA circles. The discovery of circRNAs discloses a new layer of gene regulation occurred post-transcriptionally. Identification of endogenous circRNAs benefits from the advance in high-throughput RNA sequencing and remains challenging. Many studies probing into the mechanisms of circRNAs formation occurred cotranscriptionally or posttranscriptionally emerge and conclude that canonical splicing mechanism, sequence properties, and certain regulatory factors are at play in the process. Although our knowledge on functions of circRNAs is rather limited, a few circRNAs are shown to sponge miRNA and regulate gene transcription. The clearest case is one circRNA CDR1as that serves as sponge of miR-7. Researches on circRNAs in human diseases such as cancers highlight the function and physical relevance of circRNAs. Given the implication of miRNAs in the initiation and progression of systemic lupus erythematosus (SLE) and the roles of circRNAs in sponging miRNA and gene regulation, it is appealing to speculate that circRNAs may associate with SLE and may be potential therapeutic targets for treatment of SLE. Future studies should attach more importance to the relationship between circRNAs and SLE. This review will concern identification, biogenesis, and function of circRNAs, introduce reports exploring the association of circRNAs with human diseases, and conjecture the potential roles of circRNAs in SLE. PMID:27450756

  9. Failure of Non-Circular Composite Cylinders

    Science.gov (United States)

    Hyer, M. W.

    2004-01-01

    In this study, a progressive failure analysis is used to investigate leakage in internally pressurized non-circular composite cylinders. This type of approach accounts for the localized loss of stiffness when material failure occurs at some location in a structure by degrading the local material elastic properties by a certain factor. The manner in which this degradation of material properties takes place depends on the failure modes, which are determined by the application of a failure criterion. The finite-element code STAGS, which has the capability to perform progressive failure analysis using different degradation schemes and failure criteria, is utilized to analyze laboratory scale, graphite-epoxy, elliptical cylinders with quasi-isotropic, circumferentially-stiff, and axially-stiff material orthotropies. The results are divided into two parts. The first part shows that leakage, which is assumed to develop if there is material failure in every layer at some axial and circumferential location within the cylinder, does not occur without failure of fibers. Moreover before fibers begin to fail, only matrix tensile failures, or matrix cracking, takes place, and at least one layer in all three cylinders studied remain uncracked, preventing the formation of a leakage path. That determination is corroborated by the use of different degradation schemes and various failure criteria. Among the degradation schemes investigated are the degradation of different engineering properties, the use of various degradation factors, the recursive or non-recursive degradation of the engineering properties, and the degradation of material properties using different computational approaches. The failure criteria used in the analysis include the noninteractive maximum stress criterion and the interactive Hashin and Tsai-Wu criteria. The second part of the results shows that leakage occurs due to a combination of matrix tensile and compressive, fiber tensile and compressive, and inplane

  10. Stochastic conditional intensity processes

    DEFF Research Database (Denmark)

    Bauwens, Luc; Hautsch, Nikolaus

    2006-01-01

    model allows for a wide range of (cross-)autocorrelation structures in multivariate point processes. The model is estimated by simulated maximum likelihood (SML) using the efficient importance sampling (EIS) technique. By modeling price intensities based on NYSE trading, we provide significant evidence......In this article, we introduce the so-called stochastic conditional intensity (SCI) model by extending Russell’s (1999) autoregressive conditional intensity (ACI) model by a latent common dynamic factor that jointly drives the individual intensity components. We show by simulations that the proposed...... for a joint latent factor and show that its inclusion allows for an improved and more parsimonious specification of the multivariate intensity process...

  11. High intensity hadron accelerators

    International Nuclear Information System (INIS)

    In this paper we give an introductory discussion of high intensity hadron accelerators with special emphasis on the high intensity feature. The topics selected for this discussion are: Types of acclerator - The principal actions of an accelerator are to confine and to accelerate a particle beam. Focusing - This is a discussion of the confinement of single particles. Intensity limitations - These are related to confinement of intense beams of particles. Power economics - Considerations related to acceleration of intense beams of particles. Heavy ion kinematics - The adaptation of accelerators to accelerate all types of heavy ions

  12. Comparing modal noise and FRD of circular and non-circular cross-section fibres

    Science.gov (United States)

    Sablowski, D. P.; Plüschke, D.; Weber, M.; Strassmeier, K. G.; Järvinen, A.

    2016-03-01

    Modal noise is a common source of noise introduced to the measurements by optical fibres and is particularly important for fibre-fed spectroscopic instruments, especially for high-resolution measurements. This noise source can limit the signal-to-noise ratio and jeopardize photon-noise limited data. The subject of the present work is to compare measurements of modal noise and focal-ratio degradation (FRD) for several commonly used fibres. We study the influence of a simple mechanical scrambling method (excenter) on both FRD and modal noise. Measurements are performed with circular and octagonal fibres from Polymicro Technology (FBP-Series) with diameters of 100, 200, and 300 μm and for square and rectangular fibres from CeramOptec, among others. FRD measurements for the same sample of fibres are performed as a function of wavelength. Furthermore, we replaced the circular fibre of the STELLA-échelle-spectrograph (SES) in Tenerife with an octagonal and found a SNR increase by a factor of 1.6 at 678 nm. It is shown in the laboratory that an excenter with a large amplitude and low frequency will not influence the FRD but will reduce modal noise rather effectively by up to 180%.

  13. Vibration of circular plate with multiple eccentric circular perforations by the Rayleigh-Ritz method

    International Nuclear Information System (INIS)

    The free vibration of a circular plate with multiple perforations is analyzed by using the Rayleigh-Ritz method. Admissible functions are assumed to be separable functions of radial and tangential coordinates. Trigonometric functions are assumed in the circumferential direction. The radial shape functions are the boundary characteristic orthogonal polynomials generated following the Gram-Schmidt recurrence scheme. The assumed functions are used to estimate the kinetic and the potential energies of the plate depending on the number and the position of the perforations. The eigenvalues, representing the dimensionless natural frequencies, are compared with the results obtained using Bessel functions, where the exact solution is available. Moreover, the eigenvectors, which are the unknown coefficients of the Rayleigh-Ritz method, are used to present the mode shapes of the plate. To validate the analytical results of the plates with multiple perforations, experimental investigations are also performed. Two unique case studies that are not addressed in the existing literature are considered. The results of the Rayleigh-Ritz method are found to be in good agreement with those from the experiments. Although the method presented can be employed in the vibration analysis of plates with different boundary conditions and shapes of the perforations, circular perforations that are free on the edges are studied in this paper. The results are presented in terms of dimensionless frequencies and mode shapes

  14. Comparing modal noise and FRD of circular and non-circular cross- section fibres

    CERN Document Server

    Sablowski, D P; Weber, M; Strassmeier, K G; Järvinen, A

    2015-01-01

    Modal noise is a common source of noise introduced to the measurements by optical fibres and is particularly important for fibre-fed spectroscopic instruments, especially for high-resolution measurements. This noise source can limit the signal-to-noise ratio and jeopardize photon-noise limited data. The subject of the present work is to compare measurements of modal noise and focal-ratio degradation (FRD) for several commonly-used fibres. We study the influence of a simple mechanical scrambling method (excenter) on both FRD and modal noise. Measurements are performed with circular and octagonal fibres from Polymicro Technology (FBP-Series) with diameters of 100, 200 and 300 {\\mu}m and for square and rectangular fibres from CeramOptec, among others. FRD measurements for the same sample of fibres are performed as a function of wavelength. Furthermore, we replaced the circular fibre of the STELLA-echelle-spectrograph (SES) in Tenerife with an octagonal and found a SNR increase by a factor of 1.6 at 678 nm. It is...

  15. Circular Polarization of Radio Emission from Relativistic Jets

    CERN Document Server

    Beckert, T; Beckert, Thomas; Falcke, Heino

    2002-01-01

    In inhomogeneous optically thick synchrotron sources a substantial part of the electron population at low energies can be hidden by self-absorption and overpowered by high energy electrons in optically thin emission. These invisible electrons produce Faraday rotation and conversion, leaving their footprints in the linear and circular polarized radiation of the source. An important factor is also the magnetic field structure, which can be characterized in most cases by a global magnetic field and a turbulent component. We present the basic radiative transfer coefficients for polarized synchrotron radiation and apply them to the standard jet model for relativistic radio jets. The model can successfully explain the unusual circular and linear polarization of the Galactic Centre radio source Sgr A* and its sibling M81*. It also can account for the circular polarization found in jets of more luminous quasars and X-ray binaries. The high ratio of circular to linear polarization requires the presence of a significan...

  16. An analysis of near-circular lunar mapping orbits

    Indian Academy of Sciences (India)

    R V Ramanan; V Adimurthy

    2005-12-01

    Numerical investigations have been carried out to analyse the evolution of lunar circular orbits and the influence of the higher order harmonics of the lunar gravity field.The aim is to select the appropriate near-circular orbit characteristics,which extend orbit life through passive orbit maintenance.The spherical harmonic terms that make major contributions to the orbital behaviour are identified through many case studies.It is found that for low circular orbits,the 7th and the 9th zonal harmonics have predominant effect in the case of orbits for which the evolution is stable and the life is longer,and also in the case of orbits for which the evolution is unstable and a crash takes place in a short duration.By analysing the contribution of the harmonic terms to the orbit behaviour,the appropriate near-circular orbit characteristics are identified.

  17. Monotonic Loading of Circular Surface Footings on Clay

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Barari, Amin

    2011-01-01

    Appropriate modeling of offshore foundations under monotonic loading is a significant challenge in geotechnical engineering. This paper reports experimental and numerical analyses, specifically investigating the response of circular surface footings during monotonic loading and elastoplastic...

  18. Shock wave propagation of circular dam break problems

    International Nuclear Information System (INIS)

    We examine the behavior of shock wave propagation of circular (radial) dam break problems. A dam break problem represents a reservoir having two sides of water at rest initially with different depth separated by a wall, then water flows after the wall is removed. The behavior of shock wave propagation is investigated with respect to water levels and with respect to the speeds of the shock waves. To the author's knowledge, such investigation for circular dam break problems had never been done before. Therefore, this new work shall be important for applied computational mathematics and physics communities as well as fluid dynamic researchers. Based on our research results, the propagation speed of shock wave in a circular dam break is lower than that of shock wave in a planar dam break having the same initial water levels as in the circular dam break

  19. Electrically pumped semiconductor laser with monolithic control of circular polarization.

    Science.gov (United States)

    Rauter, Patrick; Lin, Jiao; Genevet, Patrice; Khanna, Suraj P; Lachab, Mohammad; Giles Davies, A; Linfield, Edmund H; Capasso, Federico

    2014-12-30

    We demonstrate surface emission of terahertz (THz) frequency radiation from a monolithic quantum cascade laser with built-in control over the degree of circular polarization by "fishbone" gratings composed of orthogonally oriented aperture antennas. Different grating concepts for circularly polarized emission are introduced along with the presentation of simulations and experimental results. Fifth-order gratings achieve a degree of circular polarization of up to 86% within a 12°-wide core region of their emission lobes in the far field. For devices based on an alternative transverse grating design, degrees of circular polarization as high as 98% are demonstrated for selected far-field regions of the outcoupled THz radiation and within a collection half-angle of about 6°. Potential and limitations of integrated antenna gratings for polarization-controlled emission are discussed. PMID:25512515

  20. Numerical simulation for flow around two circular cylinders in tandem

    Science.gov (United States)

    Kondo, Norio; Matsukuma, Daisuke

    2005-05-01

    We use a third-order upwind finite element scheme in order to perform numerical stabilization of solutions of the Navier Stokes equations and present numerical results of flow around two circular cylinders in tandem arrangement by two- and three-dimensional computations. The two circular cylinders are arranged with some spacings between the cylinders. It is well known from experimental data that the flow around two circular cylinders denotes very complicated phenomena with the variation of spacing between two cylinders. In addition, the time-averaged drag coefficients of two circular cylinders suddenly change at a certain spacing between the cylinders. We, therefore, make an investigation of such phenomena at the Reynolds number of 1000 by the use of a numerical approach, and the obtained numerical results are also qualitatively compared with experimental data.

  1. Procedure for Detecting Outliers in a Circular Regression Model

    Science.gov (United States)

    Rambli, Adzhar; Abuzaid, Ali H. M.; Mohamed, Ibrahim Bin; Hussin, Abdul Ghapor

    2016-01-01

    A number of circular regression models have been proposed in the literature. In recent years, there is a strong interest shown on the subject of outlier detection in circular regression. An outlier detection procedure can be developed by defining a new statistic in terms of the circular residuals. In this paper, we propose a new measure which transforms the circular residuals into linear measures using a trigonometric function. We then employ the row deletion approach to identify observations that affect the measure the most, a candidate of outlier. The corresponding cut-off points and the performance of the detection procedure when applied on Down and Mardia’s model are studied via simulations. For illustration, we apply the procedure on circadian data. PMID:27064566

  2. Diagnostics of Circular Sawblade Vibration by Displacement Sensors

    Directory of Open Access Journals (Sweden)

    Přemysl Veselý

    2012-06-01

    Full Text Available The paper deals with problems of the circular sawblade vibration. In the introductory part, theoretical bases are summarized to determine the form of vibrations and critical and resonant rotational frequency. A diagnostic method is proposed for the direct measurement of amplitudes of a circular sawblade by displacement sensors with the subsequent Fast Fourier Transform (FFT analysis. This method with the spectral analysis of a signal in the time area makes possible to determine the size and shape of vibration of a circular sawblade with respect to usability/applicability under operational conditions. Unlike standard methods, when the sawblade is excited by external sources, natural vibrations are used such as disk deformations and the dynamic unbalance of a circular sawblade, effects of chucking/gripping and machine vibration and, last but not least, the disk and sawn wood interaction.

  3. Generation of Circular Polarization of the Cosmic Microwave Background

    CERN Document Server

    Alexander, Stephon; Kosowsky, Arthur

    2008-01-01

    The standard cosmological model, which includes only Compton scattering photon interactions at energy scales near recombination, results in zero primordial circular polarization of the cosmic microwave background. In this paper we consider a particular renormalizable and gauge-invariant standard model extension coupling photons to an external vector field via a Chern-Simons term, which arises as a radiative correction if gravitational torsion couples to fermions. We compute the transport equations for polarized photons from a Boltzmann-like equation, showing that such a coupling will source circular polarization of the microwave background. For the particular coupling considered here, the circular polarization effect is always negligible compared to the rotation of the linear polarization orientation, also derived using the same formalism. We note the possibility that limits on microwave background circular polarization may probe other photon interactions and related fundamental effects such as violations of ...

  4. The interaction of circularly polarised electromagnetic waves with a plasma

    International Nuclear Information System (INIS)

    The interaction of left and right handed circularly polarised waves with a plasma are studied. The individual trajectories of charges of both signs are traced with a analogical simulator. Applications to plasma heating and diagnostic are deduced. (author)

  5. Administrative Circular No. 23 (Rev. 4) - Special working hours

    CERN Multimedia

    Department Head Office - HR Department

    2016-01-01

    Administrative Circular No. 23 (Rev. 4) entitled "Special working hours", approved by the Director-General following discussion in the Standing Concertation Committee meeting on 22 March 2016, will be available on 1st September 2016 via the following link: https://cds.cern.ch/record/2208539.   This revised circular cancels and replaces Administrative Circular No. 23 (Rev. 3) also entitled "Special working hours" of January 2013. This document contains modifications to reflect the new career structure and ensuring the provision consistent with practice that compensation or remuneration of special working hours performed remotely is possible only in case of emergency.   This circular will enter into force on 1st September 2016.

  6. Circular orbits in extremal Reissner-Nordstrom spacetime

    Energy Technology Data Exchange (ETDEWEB)

    Pradhan, Parthapratim, E-mail: pppradhan77@gmail.co [Department of Physics, Vivekananda Satabarshiki Mahavidyalaya, Manikpara, Paschim Medinipur, WestBengal 721513 (India); Majumdar, Parthasarathi, E-mail: parthasarathi.majumdar@saha.ac.i [Saha Institute of Nuclear Physics, Kolkata 700 064 (India)

    2011-01-17

    Circular null geodesic orbits, in extremal Reissner-Nordstrom spacetime, are examined with regard to their stability, and compared with similar orbits in the near-extremal situation. Extremization of the effective potential for null circular orbits shows the existence of a stable circular geodesic in the extremal spacetime, precisely on the event horizon which coincides with the null geodesic generator. Such a null orbit on the horizon is also indicated by the global minimum of the effective potential for circular timelike orbits. This type of geodesic is of course absent in the corresponding near-extremal spacetime, as we show here, testifying to differences between the extremal limit of a generic RN spacetime and the exactly extremal geometry.

  7. Differential equations

    CERN Document Server

    Tricomi, FG

    2012-01-01

    Based on his extensive experience as an educator, F. G. Tricomi wrote this practical and concise teaching text to offer a clear idea of the problems and methods of the theory of differential equations. The treatment is geared toward advanced undergraduates and graduate students and addresses only questions that can be resolved with rigor and simplicity.Starting with a consideration of the existence and uniqueness theorem, the text advances to the behavior of the characteristics of a first-order equation, boundary problems for second-order linear equations, asymptotic methods, and differential

  8. Differential geometry

    CERN Document Server

    Guggenheimer, Heinrich W

    1977-01-01

    This is a text of local differential geometry considered as an application of advanced calculus and linear algebra. The discussion is designed for advanced undergraduate or beginning graduate study, and presumes of readers only a fair knowledge of matrix algebra and of advanced calculus of functions of several real variables. The author, who is a Professor of Mathematics at the Polytechnic Institute of New York, begins with a discussion of plane geometry and then treats the local theory of Lie groups and transformation groups, solid differential geometry, and Riemannian geometry, leading to a

  9. Piezoelectric shunt damping of a circular saw blade with autonomous power supply for noise and vibration reduction

    Science.gov (United States)

    Pohl, Martin; Rose, Michael

    2016-01-01

    Circular saws are widespread tools for machining metal, wood or even ceramics. Due to the thin blade and excitation by the workpiece contact of the cutting edges, circular saws are prone to vibration and intense noise emission. Damping the blade will lower the hearing protection requirements of the users and possibly increase precision. Therefore a new damping concept for circular saw blades is presented in this paper. It is based on negative capacitance shunted piezoelectric transducers which are applied to the saw blade core. The required energy for the electronics is harvested from the rotation by a generator, so that no change of the machine tool is required. All components are integrated into an autonomous saw tool. Finally, the system is experimentally investigated without rotation, in idling and in cutting condition in a circular saw test stand in the Institute for Machine Tools and Production Engineering (IWF) at TU Braunschweig. The experimental investigation shows a good reduction of the vibration amplitude over a wide frequency range in the non-rotating condition. When rotating, the damping effect is lower and limited to some narrow frequency bands. The proposed reason for the reduced damping effect in rotating condition consists in the saturation of the electronic circuits due to the limited supply voltage capabilities.

  10. Limiting Geometries of Two Circular Maldacena-Wilson Loop Operators

    OpenAIRE

    Arutyunov, G.; Plefka, J.; Staudacher, M.

    2001-01-01

    We further analyze a recent perturbative two-loop calculation of the expectation value of two axi-symmetric circular Maldacena-Wilson loops in [Script N] = 4 gauge theory. Firstly, it is demonstrated how to adapt the previous calculation of anti-symmetrically oriented circles to the symmetric case. By shrinking one of the circles to zero size we then explicitly work out the first few terms of the local operator expansion of the loop. Our calculations explicitly demonstrate that circular Mald...

  11. Contactless Measurement of Angular Velocity using Circularly Polarized Antennas

    OpenAIRE

    Sipal, Vit; Narbudowicz, Adam; Ammann, Max

    2014-01-01

    An innovative method to measure the angular velocity using circularly polarized antennas is proposed. Due to the properties of circular polarization, the angular velocity is frequency modulated (FM) on a wireless carrier. This enables a low-cost precise continuous measurement of angular velocity using a standard FM demodulator. The hardware can be easily adapted for both high and low angular velocity values. The precise alignment angle between the antennas can be determined if the initial ant...

  12. Possible potentials responsible for stable circular relativistic orbits

    OpenAIRE

    Kumar, Prashant; Bhattacharya, Kaushik

    2011-01-01

    Bertrand's theorem in classical mechanics of the central force fields attracts us because of its predictive power. It categorically proves that there can only be two types of forces which can produce stable, circular orbits. In the present article an attempt has been made to generalize Bertrand's theorem to the central force problem of relativistic systems. The stability criterion for potentials which can produce stable, circular orbits in the relativistic central force problem has been deduc...

  13. Designing out waste: an exploratory study of circular business models

    OpenAIRE

    Poutiainen, Paige Swaffer

    2015-01-01

    The circular economy is an emerging model that experts believe is able to resolve the conflict between resource constraints, environmental degradation and economic growth. In short, it is a model for an economy designed to work in harmony with the environment by designing out waste, relying on renewable energy and embracing diversity and systems thinking. Many have claimed that companies will lead the transition to a circular economy. However, much is still not understood about how companies ...

  14. Electronic and vibrational circular dichroism spectra of (R)-(-)-apomorphine

    Science.gov (United States)

    Abbate, Sergio; Longhi, Giovanna; Lebon, France; Tommasini, Matteo

    2012-09-01

    Apomorphine is a chiral drug molecule; notwithstanding its extraordinary importance, little attention has been paid to the characterization of its chiroptical properties. Here we report on its electronic circular dichroism (ECD) spectra, recorded in methanol and water, and vibrational circular dichroism (VCD) in methanol and dimethyl sulfoxide (DMSO) solutions. Density functional theory (DFT) calculations have allowed us to interpret the spectra and to evaluate the role of possible conformations, charge-states and interactions with counter ions.

  15. Omnidirectional Circularly Polarized Patch Antenna with Post Manufacture Characteristic Refinement

    OpenAIRE

    Narbudowicz, Adam; Bao, Xiulong; Ammann, Max

    2013-01-01

    We propose an omnidirectional circularly polarised planar microstrip patch antenna, in which both impedance bandwidth and circular polarization properties can be adjusted after antenna manufacture. This is done by appropriately tuning four adjustable capacitors, incorporated into the patches. To demonstrate the properties, the proposed antenna is tuned to the GPS L1 band and then re-tuned for Beidou/Galileo E2 band by only changing capacitors values. Design guidelines for such retuning are pr...

  16. Simulation, Kringing, and Visualization of Circular-Spatial Data

    OpenAIRE

    Morphet, William James

    2009-01-01

    The circular dataimage is defined by displaying direction as the color at the same direction in a color wheel composed of a sequence of two-color gradients with color continuity between gradients. The resulting image of circular-spatial data is continuous with high resolution. Examples include ocean wind direction, Earth's main magnetic field, and rocket nozzle internal combustion flow. The cosineogram is defined as the mean cosine of the angle between random components of direction as a f...

  17. The benefits of planar circular mouths on suction feeding performance

    OpenAIRE

    Skorczewski, Tyler; Cheer, Angela; Wainwright, Peter C

    2012-01-01

    Suction feeding is the most common form of prey capture across aquatic feeding vertebrates and many adaptations that enhance efficiency and performance are expected. Many suction feeders have mechanisms that allow the mouth to form a planar and near-circular opening that is believed to have beneficial hydrodynamic effects. We explore the effects of the flattened and circular mouth opening through computational fluid dynamics simulations that allow comparisons with other mouth profiles. Compar...

  18. The Propagation of Circularly Polarized Waves in Quantum Plasma

    OpenAIRE

    Rehab Albrulosy; Bahaa F. Mohamed

    2013-01-01

    The quantum effects on the propagation circularly polarized waves have been investigated in electron magnetized quantum plasmas. We obtain the dispersion equations of the propagation of circularly polarized laser beam through cold plasma. The results show that the laser can be propagated due to the quantum effects which enhance the propagation phase velocity. For this purpose, the quantum hydrodynamic (QHD) equations with magnetic field and Maxwell’s equations system is used to derive these ...

  19. Circular dichroism induced by Fano resonances in planar chiral oligomers

    CERN Document Server

    Hopkins, Ben; Miroshnichenko, Andrey E; Kivshar, Yuri S

    2016-01-01

    We present a general theory of circular dichroism induced in planar chiral nanostructures with rotational symmetry. It is demonstrated, analytically, that the handedness of the incident field's polarization can control whether a nanostructure induces either absorption or scattering losses, even when the total loss (extinction) is polarization-independent. We then show that this effect is a consequence of modal interference so that strong circular dichroism in absorption and scattering can be engineered by combining Fano resonances with chiral nanoparticle clusters.

  20. Circular dichroism from Fano resonances in planar chiral oligomers

    Science.gov (United States)

    Hopkins, Ben; Poddubny, Alexander N.; Miroshnichenko, Andrey E.; Kivshar, Yuri S.

    2015-05-01

    Here we present a general approach for describing the physics of Fano resonances in nanoparticle oligomers. It is shown that the interference of nonorthogonal collective eigenmodes is a sufficient condition to produce Fano resonances. We then show that such nonorthogonality between eigenmodes also permits the existence of a new form circular dichroism in the absorption and scattering cross-sections, even when circular dichroism is forbidden in the extinction cross-section.