Sample records for attached vibrational probe

  1. Vibrationally Resolved Electron Attachment to Oxygen Clusters (United States)

    Matejcik, S.; Kiendler, A.; Stampfli, P.; Stamatovic, A.; Märk, T. D.


    Highly monochromatized electrons (with 30 meV FWHM) are used in a crossed beam experiment to investigate electron attachment to oxygen clusters \\(O2\\)n at electron energies from approximately 0 to 2 eV. At energies close to zero, the attachment cross section for the reaction \\(O2\\)n+e-->O-2 rises strongly with decreasing electron energy compatible with s-wave electron capture to \\(O2\\)n. Peaks in the attachment cross section present at higher energies can be ascribed to vibrational levels of the oxygen anion. The vibrational spacings observed can be quantitatively accounted for by model calculations.

  2. Vibrationally Resolved Electron Attachment to Oxygen Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Matejcik, S.; Kiendler, A.; Stampfli, P.; Stamatovic, A.; Maerk, T.D. [Intitut fuer Ionenphysik, Leopold Franzens Universitaet, Technikerstrasse 25, A-6020 Innsbruck (Austria)


    Highly monochromiatized electrons (with 30meV FWHM) are used in a crossed beam experiment to investigate electron attachment to oxygen clusters (O{sub 2}){sub {ital n}} at electron energies from approximately 0 to 2eV.At energies close to zero, the attachment cross section for the reaction (O{sub 2}){sub {ital n}}+{ital e}{r_arrow}O{sub 2}{sup {minus}} rises strongly with decreasing electron energy compatible with {ital s}-wave electron capture to (O{sub 2}){sub {ital n}}. Peaks in the attachment cross section present at higher energies can be ascribed to vibrational levels of the oxygen anion. The vibrational spacings observed can be quantitatively accounted for by model calculations. {copyright} {ital 1996 The American Physical Society.}

  3. Probing zeolites by vibrational spectroscopies. (United States)

    Bordiga, Silvia; Lamberti, Carlo; Bonino, Francesca; Travert, Arnaud; Thibault-Starzyk, Frédéric


    This review addresses the most relevant aspects of vibrational spectroscopies (IR, Raman and INS) applied to zeolites and zeotype materials. Surface Brønsted and Lewis acidity and surface basicity are treated in detail. The role of probe molecules and the relevance of tuning both the proton affinity and the steric hindrance of the probe to fully understand and map the complex site population present inside microporous materials are critically discussed. A detailed description of the methods needed to precisely determine the IR absorption coefficients is given, making IR a quantitative technique. The thermodynamic parameters of the adsorption process that can be extracted from a variable-temperature IR study are described. Finally, cutting-edge space- and time-resolved experiments are reviewed. All aspects are discussed by reporting relevant examples. When available, the theoretical literature related to the reviewed experimental results is reported to support the interpretation of the vibrational spectra on an atomic level.

  4. Comparison of vibrational dynamics between non-ionic and ionic vibrational probes in water: Experimental study with two-dimensional infrared and infrared pump-probe spectroscopies (United States)

    Okuda, Masaki; Ohta, Kaoru; Tominaga, Keisuke


    Dynamics of the hydration structure around small vibrational probes have been extensively studied over the past few decades. However, we need to gain insight into how vibrational dynamics is affected by the molecular nature of the probe molecules in water. In this study, 2-nitro-5-thiocyanate benzoic acid (NTBA), which has an SCN group attached to an aromatic ring, and thiocyanate ion (SCN-) were used to investigate the vibrational dynamics of two vibrational probes, including vibrational frequency fluctuations and rotational relaxation. By performing two-dimensional infrared spectroscopic measurements, the vibrational frequency fluctuations of the SCN anti-stretching modes of these solutes were compared. The frequency-frequency time correlation function (FFTCF) of these solutes can be modeled by a delta function plus an exponential function and a constant. The FFTCF of NTBA was characterized by a time constant of 1.1 ps, which is similar to that of SCN-. Moreover, no component was longer than this constant. Consequently, the loss of the correlation in frequency fluctuations of the SCN anti-stretching mode of NTBA may be controlled by a mechanism similar to that of the ionic probe, which involves the hydrogen bonding dynamics of water. Polarization-controlled IR pump-probe measurements were performed for these vibrational probes in water to study the vibrational energy relaxation (VER) and reorientational relaxation processes. The VER rate of NTBA is much smaller than that of SCN-, which indicates that the intramolecular relaxation process is significant for VER of NTBA. Based on the rotational relaxation time of NTBA being shorter than that of SCN-, the internal rotational motion of the SCN group around the Cphenyl-S bond axis, where Cphenyl denotes a carbon atom of the aromatic ring to which the SCN group is attached, may play an important role in the anisotropic decay of NTBA in H2O.

  5. Low-energy electron attachment and detachment in vibrationally excited oxygen (United States)

    Aleksandrov, N. L.; Anokhin, E. M.


    Three-body electron attachment to O2 molecules and electron detachment from O_{2}^{-} ions have been theoretically studied in vibrationally excited oxygen and O2-containing mixtures. Assuming that electron attachment and detachment proceed via the formation of vibrationally excited temporary O_{2}^{-} ions, the rates of these processes were determined on the basis of the statistical approach for the vibrational transfer and relaxation in collisions between O_{2}^{-} ions and O2 molecules. The calculated attachment and detachment rate constants turned out to agree well with available measurements in unexcited oxygen. This method was extended to calculate attachment and detachment rates in vibrationally excited oxygen. It was shown that the effect of vibrational excitation on electron detachment is profound, whereas attachment of low-energy electrons to vibrationally excited O2 is inefficient. The calculated vibrational distribution of stable O_{2}^{-} ions turned out to be non-equilibrium in an excited gas and the effective vibrational temperature of the ions was much lower than the vibrational temperature of molecules. An analytical method was suggested to determine this distribution and the effective vibrational temperature. The calculated rate constants were used to simulate the formation and decay of an electron-beam-generated plasma in N2 : O2 mixtures at elevated vibrational temperatures. The calculations showed that vibrational excitation of molecules leads to orders of magnitude increase in the plasma density and in the plasma lifetime, in agreement with available observations.

  6. Ground vibration test and flutter analysis of air sampling probe (United States)

    Ellison, J. F.


    The Dryden Flight Research Facility of NASA Ames Research Center conducted a ground vibration test and a flutter analysis of an air sampling probe that was to be mounted on a Convair 990 airplane. The probe was a steel, wing-shaped structure used to gather atmospheric data. The ground vibration test was conducted to update the finite-element model used in the flutter analysis. The analysis predicted flutter speeds well outside the operating flight envelope of the Convair 990 airplane.

  7. Dissociative electron attachment and vibrational excitation of CF{sub 3}Cl: Effect of two vibrational modes revisited

    Energy Technology Data Exchange (ETDEWEB)

    Tarana, Michal [Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588 (United States); JILA, University of Colorado and NIST, Boulder, Colorado 80309-0440 (United States); Houfek, Karel; Horacek, Jiri [Institute of Theoretical Physics, Faculty of Mathematics and Physics, Charles University in Prague, V Holesovickach 2, Prague (Czech Republic); Fabrikant, Ilya I. [Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588 (United States); Department of Physics and Astronomy, Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom)


    We present a study of dissociative electron attachment and vibrational excitation processes in electron collisions with the CF{sub 3}Cl molecule. The calculations are based on the two-dimensional nuclear dynamics including the C-Cl symmetric stretch coordinate and the CF{sub 3} symmetric deformation (umbrella) coordinate. The complex potential energy surfaces are calculated using the ab initio R-matrix method. The results for dissociative attachment and vibrational excitation of the umbrella mode agree quite well with experiment whereas the cross section for excitation of the C-Cl symmetric stretch vibrations is about a factor-of-three too low in comparison with experimental data.

  8. Low-energy electron attachment and detachment in vibrationally excited oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Aleksandrov, N L; Anokhin, E M, E-mail: nick_aleksandrov@mail.r, E-mail: [Moscow Institute of Physics and Technology, Dolgoprudny, 141700 (Russian Federation)


    Three-body electron attachment to O{sub 2} molecules and electron detachment from O{sub 2}{sup -} ions have been theoretically studied in vibrationally excited oxygen and O{sub 2}-containing mixtures. Assuming that electron attachment and detachment proceed via the formation of vibrationally excited temporary O{sub 2}{sup -} ions, the rates of these processes were determined on the basis of the statistical approach for the vibrational transfer and relaxation in collisions between O{sub 2}{sup -} ions and O{sub 2} molecules. The calculated attachment and detachment rate constants turned out to agree well with available measurements in unexcited oxygen. This method was extended to calculate attachment and detachment rates in vibrationally excited oxygen. It was shown that the effect of vibrational excitation on electron detachment is profound, whereas attachment of low-energy electrons to vibrationally excited O{sub 2} is inefficient. The calculated vibrational distribution of stable O{sub 2}{sup -} ions turned out to be non-equilibrium in an excited gas and the effective vibrational temperature of the ions was much lower than the vibrational temperature of molecules. An analytical method was suggested to determine this distribution and the effective vibrational temperature. The calculated rate constants were used to simulate the formation and decay of an electron-beam-generated plasma in N{sub 2} : O{sub 2} mixtures at elevated vibrational temperatures. The calculations showed that vibrational excitation of molecules leads to orders of magnitude increase in the plasma density and in the plasma lifetime, in agreement with available observations.

  9. Vibration Damping Via Acoustic Treatment Attached To Vehicle Body Panels (United States)

    Gambino, Carlo

    Currently, in the automotive industry, the control of noise and vibration is the subject of much research, oriented towards the creation of innovative solutions to improve the comfort of the vehicle and to reduce its cost and weight. This thesis fits into this particular framework, as it aims to investigate the possibility of integrating the functions of sound absorptioninsulation and vibration damping in a unique component. At present the bituminous viscoelastic treatments, which are bonded to the car body panels, take charge of the vibration damping, while the sound absorption and insulation is obtained by means of the poroacoustic treatments. The solution proposed here consists of employing porous materials to perform both these functions, thus allowing the partial or complete removal of the viscoelastic damping treatments from the car body. This should decrease the weight of the vehicle, reducing fuel consumption and emissions, and it might also benefit production costs.

  10. Vibrational relaxation and decoherence of Rb_2 attached to helium nanodroplets

    CERN Document Server

    Grüner, Barbara; Heister, Philipp; Strunz, Walter T; Stienkemeier, Frank; Mudrich, Marcel


    The vibrational wave-packet dynamics of diatomic rubidium molecules (Rb_2) in triplet states formed on the surface of superfluid helium nanodroplets is investigated both experimentally and theoretically. Detailed comparison of experimental femtosecond pump-probe spectra with dissipative quantum dynamics simulations reveals that vibrational relaxation is the main source of decoherence. The rate constant for vibrational relaxation in the first excited triplet state is found to be constant ~0.5ns^-1 for the lowest vibrational levels v< 15 and to increase sharply when exciting to higher energies.

  11. Forced vibration of a ball attached to a cable

    Directory of Open Access Journals (Sweden)

    Douglas Oliver


    Full Text Available This work describes an analytic solution to predict the forced oscillation of a suspended cable and an attached ball. The oscillations are driven by a sinusoidal movement at the fixed end of the cable. This problem may be used in the verification of numerical software which is commonly used to design systems with suspended cables.

  12. Analysis of Steady Collision Vibration in Cantilever Beam Having an Attached Mass (United States)

    Aihara, Tatsuhito; Kumano, Hiroyuki; Hara, Shin-Ichi

    This paper deals with response analysis of collision vibration in continuous system excited by periodic displacement with arbitrary functions. A system of steady vibration in a cantilever beam having an attached mass at free-end is considered. The cantilever beam has structural damping in the beam, and it is being put in the viscous fluid with hydrodynamic drag. The attached mass collides elastically with the coil spring clamped on asymmetrical faces when the amplitude of mass exceeds the clearance between the coil spring and the attached mass. Then, the restoring force is assumed to be an asymmetric piecewise-linear system. For such a system, the beam undergoes a nonlinear vibration when the attached mass collides with the coil spring. In order to analyze harmonic, superharmonic and subharmonic resonances for the system, Fourier series method is applied to obtain an exact solution for resulting vibration. Next, the numerical calculation is performed to obtain the resonance curves. The numerical results show effects of the mass ratio, the amplitude ratio of excitation, the spring constant ratio, the structural damping ratio and the external damping ratio on the resonance curves. The numerical experiments are also carried out to verify the numerical results.

  13. Equilibria and vibration of a buckled beam with attached masses or spring-mass systems (United States)

    Plaut, Raymond H.; Virgin, Lawrence N.


    A buckled beam with immovable pinned ends is considered. Attached to the beam are either one concentrated mass, two concentrated masses, a spring-mass system (that could model a human, robot, or passive vibration absorber), or a horizontal rigid bar with two vertical end springs (a "bounce-pitch" system that could model an animal or a vehicle). In the theoretical analysis, the beam is modeled as an inextensible elastica. Equilibrium configurations are determined first. Then small free vibrations about equilibrium are examined, and the lowest frequencies and corresponding modes are computed. The effects of various parameters are investigated, such as the ratio of the span to the total arc length of the beam, the locations and weights of the attached masses and systems, and the stiffnesses of the springs. For the case of a single attached mass, experiments are conducted and the results are compared to the theoretical ones.

  14. Vibration of nonuniform carbon nanotube with attached mass via nonlocal Timoshenko beam theory

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Hai Li; Shen, Zhi Bin; Li, Dao Kui [National University of Defense Technology, Changsha (China)


    This paper studies the vibrational behavior of nonuniform single-walled carbon nanotube (SWCNT) carrying a nanoparticle. A nonuniform cantilever beam with a concentrated mass at the free end is analyzed according to the nonlocal Timoshenko beam theory. A governing equation of a nonuniform SWCNT with attached mass is established. The transfer function method incorporating with the perturbation method is utilized to obtain the resonant frequencies of a vibrating nonlocal cantilever-mass system. The effects of the nonlocal parameter, taper ratio and attached mass on the natural frequencies and frequency shifts are discussed. Obtained results indicate that the sensitivity of the frequency shifts on the attached mass increases when the length-to-diameter ratio decreases. Tapered SWCNT possesses higher fundamental frequencies if the taper ratio becomes larger.

  15. Study of a vibrating fiber probing system for 3-D micro-structures: performance improvement (United States)

    Murakami, H.; Katsuki, A.; Sajima, T.; Suematsu, T.


    This paper presents a system for measuring 3D micro-structures that uses an optical fiber probe equipped with a piezo element that causes the probe to vibrate. The optical fiber probe consists of a stylus shaft with a diameter of 3 µm and a glass ball with a diameter of 5 µm attached to the tip. The stylus is vibrated in a circular motion in a single plane. The vibrator mechanism is introduced to prevent adhesion of the stylus tip to the surface being measured. This adhesion, which adversely affects the accuracy and time of the measurement, is caused by intermolecular, electrostatic, and liquid bridge forces. The measuring principle involves monitoring the vibrational amplitude of the stylus shaft that is required to prevent the adhesion of the stylus tip to the surface being measured, this amplitude being measured optically. In our previous report (Murakami et al 2012 Key Eng. Mater. 523-524 907-12), we found that the stylus shaft actually moves in an elliptical motion when it is set to describe a circular motion in the X-Y plane. Therefore, when a measurement is taken, it is necessary to adjust the motion of the piezoelectric tube to compensate for the difference between the diameter of the perfect circle and the actual elliptical motion of the stylus shaft displacement. In this study, the stylus characteristics were examined and the motion of the stylus shaft was then corrected to attain the desired circular motion. Next, the expansion of the measuring area by using a line laser was investigated. Finally, an experiment involving the measurement of a micro-hole was performed to demonstrate the practicality of the vibrating fiber probe. As a result, it was shown that the displacement between the diameter of the perfect circle and the actual elliptical motion of the stylus tip was about 0.034 µm after compensation. In addition, it was confirmed that the measurement area can be expanded by using an optical slit, but the standard deviation of the

  16. Rate coefficients for dissociative attachment and resonant electron-impact dissociation involving vibrationally excited O{sub 2} molecules

    Energy Technology Data Exchange (ETDEWEB)

    Laporta, V. [Istituto di Metodologie Inorganiche e dei Plasmi, CNR, Bari, Italy and Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Celiberto, R. [Dipartimento di Ingegneria Civile, Ambientale, del Territorio, Edile e di Chimica, Politecnico di Bari, Italy and Istituto di Metodologie Inorganiche e dei Plasmi, CNR, Bari (Italy); Tennyson, J. [Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom)


    Rate coefficients for dissociative electron attachment and electron-impact dissociation processes, involving vibrationally excited molecular oxygen, are presented. Analytical fits of the calculated numerical data, useful in the applications, are also provided.

  17. Modeling and experimental vibration analysis of nanomechanical cantilever active probes (United States)

    Salehi-Khojin, Amin; Bashash, Saeid; Jalili, Nader


    Nanomechanical cantilever (NMC) active probes have recently received increased attention in a variety of nanoscale sensing and measurement applications. Current modeling practices call for a uniform cantilever beam without considering the intentional jump discontinuities associated with the piezoelectric layer attachment and the NMC cross-sectional step. This paper presents a comprehensive modeling framework for modal characterization and dynamic response analysis of NMC active probes with geometrical discontinuities. The entire length of the NMC is divided into three segments of uniform beams followed by applying appropriate continuity conditions. The characteristics matrix equation is then used to solve for system natural frequencies and mode shapes. Using an equivalent electromechanical moment of a piezoelectric layer, forced motion analysis of the system is carried out. An experimental setup consisting of a commercial NMC active probe from Veeco and a state-of-the-art microsystem analyzer, the MSA-400 from Polytec, is developed to verify the theoretical developments proposed here. Using a parameter estimation technique based on minimizing the modeling error, optimal values of system parameters are identified. Mode shapes and the modal frequency response of the system for the first three modes determined from the proposed model are compared with those obtained from the experiment and commonly used theory for uniform beams. Results indicate that the uniform beam model fails to accurately predict the actual system response, especially in multiple-mode operation, while the proposed discontinuous beam model demonstrates good agreement with the experimental data. Such detailed and accurate modeling framework can lead to significant enhancement in the sensitivity of piezoelectric-based NMC sensors for use in variety of sensing and imaging applications.

  18. Dissociative electron attachment and electron-impact resonant dissociation of vibrationally excited O2 molecules

    CERN Document Server

    Laporta, V; Tennyson, J


    State-by-state cross sections for dissociative electron attachment and electron-impact dissociation for molecular oxygen are computed using ab initio resonance curves calculated with the R-matrix method. When O2 is in its vibrational ground state, the main contribution for both processes comes from the $^2\\Pi_u$ resonance state of $O_2^-$ but with a significant contribution from the $^4\\Sigma$ resonant state. Vibrational excitation leads to an increased contribution from the low-lying $^2\\Pi_{g}$ resonance, greatly increased cross sections for both processes, and the threshold moving to lower energies. These results provide important input for models of O2-containing plasmas in nonequilibrium conditions.

  19. Vibrational dynamics of aqueous hydroxide solutions probed using broadband 2DIR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Aritra [Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, University of Chicago, Chicago, Illinois 60637 (United States); Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Tokmakoff, Andrei, E-mail: [Department of Chemistry, James Franck Institute, and Institute for Biophysical Dynamics, University of Chicago, Chicago, Illinois 60637 (United States)


    We employed ultrafast transient absorption and broadband 2DIR spectroscopy to study the vibrational dynamics of aqueous hydroxide solutions by exciting the O–H stretch vibrations of the strongly hydrogen-bonded hydroxide solvation shell water and probing the continuum absorption of the solvated ion between 1500 and 3800 cm{sup −1}. We observe rapid vibrational relaxation processes on 150–250 fs time scales across the entire probed spectral region as well as slower vibrational dynamics on 1–2 ps time scales. Furthermore, the O–H stretch excitation loses its frequency memory in 180 fs, and vibrational energy exchange between bulk-like water vibrations and hydroxide-associated water vibrations occurs in ∼200 fs. The fast dynamics in this system originate in strong nonlinear coupling between intra- and intermolecular vibrations and are explained in terms of non-adiabatic vibrational relaxation. These measurements indicate that the vibrational dynamics of the aqueous hydroxide complex are faster than the time scales reported for long-range transport of protons in aqueous hydroxide solutions.

  20. Probing and extracting the structure of vibrating SF6 molecules with inner-shell photoelectrons (United States)

    Nguyen, Ngoc-Ty; Lucchese, R. R.; Lin, C. D.; Le, Anh-Thu


    We propose a scheme for probing the structure of vibrating molecules with photoelectrons generated from ultrashort soft-x-ray pulses. As an example we analyze below-100-eV photoelectrons liberated from the S (2 p ) orbital of vibrating SF6 molecules to image very small structural changes of molecular vibration. In particular, photoionization cross sections and photoelectron angular distributions (PAD) at nonequilibrium geometries can be retrieved accurately with photoelectrons near the shape resonance at 13 eV. This is achieved with a pump-probe scheme, in which the symmetric stretch mode is first Raman excited predominantly by a relatively short laser pulse and then later probed at different time delays by a few-femtosecond soft-x-ray pulse with photon energy near 200 eV.

  1. Spectroscopic probes of vibrationally excited molecules at chemically significant energies

    Energy Technology Data Exchange (ETDEWEB)

    Rizzo, T.R. [Univ. of Rochester, NY (United States)


    This project involves the application of multiple-resonance spectroscopic techniques for investigating energy transfer and dissociation dynamics of highly vibrationally excited molecules. Two major goals of this work are: (1) to provide information on potential energy surfaces of combustion related molecules at chemically significant energies, and (2) to test theoretical modes of unimolecular dissociation rates critically via quantum-state resolved measurements.

  2. Towards vibrational spectroscopy on surface-attached colloids performed with a quartz crystal microbalance

    Directory of Open Access Journals (Sweden)

    Diethelm Johannsmann


    Full Text Available Colloidal spheres attached to a quartz crystal microbalance (QCM produce the so-called “coupled resonances”. They are resonators of their own, characterized by a particle resonance frequency, a resonance bandwidth, and a modal mass. When the frequency of the main resonator comes close to the frequency of the coupled resonance, the bandwidth goes through a maximum. A coupled resonance can be viewed as an absorption line in acoustic shear-wave spectroscopy. The known concepts from spectroscopy apply. This includes the mode assignment problem, selection rules, and the oscillator strength. In this work, the mode assignment problem was addressed with Finite Element calculations. These reveal that a rigid sphere in contact with a QCM displays two modes of vibration, termed “slipping” and “rocking”. In the slipping mode, the sphere rotates about its center; it exerts a tangential force onto the resonator surface at the point of contact. In the rocking mode, the sphere rotates about the point of contact; it exerts a torque onto the substrate. In liquids, both axes of rotation are slightly displaced from their ideal positions. Characteristic for spectroscopy, the two modes do not couple to the mechanical excitation equally well. The degree of coupling is quantified by an oscillator strength. Because the rocking mode mostly exerts a torque (rather than a tangential force, its coupling to the resonator's tangential motion is weak; the oscillator strength consequently is small. Recent experiments on surface-adsorbed colloidal spheres can be explained by the mode of vibration being of the rocking type.

  3. Using Vibrations to Probe and Control Photoisomerization in Liquids (United States)


    toward the conical intersection. Resonance Raman scattering experiments show that the C=C stretching vibration of the central ethylenic bond has a...Figure 1, that controls the passage of the system towards the conical intersection. Because crossing the barrier takes substantially longer than the...teristic times for motion on the excited- and ground-state surfaces. The excited molecule moves to the conical intersection in about 300 fs and takes

  4. The distribution of lipid attached spin probes in bilayers: application to membrane protein topology. (United States)

    Vogel, Alexander; Scheidt, Holger A; Huster, Daniel


    The distribution of the lipid-attached doxyl electron paramagnetic resonance (EPR) spin label in 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine membranes has been studied by (1)H and (13)C magic angle spinning nuclear magnetic resonance relaxation measurements. The doxyl spin label was covalently attached to the 5th, 10th, and 16th carbons of the sn-2 stearic acid chain of a 1-palmitoyl-2-stearoyl-(5/10/16-doxyl)-sn-glycero-3-phosphocholine analog. Due to the unpaired electron of the spin label, (1)H and (13)C lipid relaxation rates are enhanced by paramagnetic relaxation. For all lipid segments the influence of paramagnetic relaxation is observed even at low probe concentrations. Paramagnetic relaxation rates provide a measure for the interaction strength between lipid segments and the doxyl group. Plotted along the membrane director a transverse distribution profile of the EPR probe is obtained. The chain-attached spin labels are broadly distributed in the membrane with a maximum at the approximate chain position of the probe. Both (1)H and (13)C relaxation measurements show these broad distributions of the doxyl group in the membrane indicating that (1)H spin diffusion does not influence the relaxation measurements. The broad distributions of the EPR label result from the high degree of mobility and structural heterogeneity in liquid-crystalline membranes. Knowing the distribution profiles of the EPR probes, their influence on relaxation behavior of membrane inserted peptide and protein segments can be studied by (13)C magic angle spinning nuclear magnetic resonance. As an example, the location of Ala residues positioned at three sites of the transmembrane WALP-16 peptide was investigated. All three doxyl-labeled phospholipid analogs induce paramagnetic relaxation of the respective Ala site. However, for well ordered secondary structures the strongest relaxation enhancement is observed for that doxyl group in the closest proximity to the respective Ala. Thus

  5. Cable vibration control with both lateral and rotational dampers attached at an intermediate location (United States)

    Chen, Lin; Sun, Limin; Nagarajaiah, Satish


    Lateral dampers have been extensively studied and implemented for supplementing modal damping in cable vibration mitigation. When considering the cable flexural stiffness that is actually present, albeit small, there is another degree of freedom of the cable at the lateral damper, namely the rotation, that can be constrained by a rotational damper to achieve larger additional damping. This is of particular significance for long cables where the near-anchorage lateral damper alone is usually insufficient. The problem of a cable with bending stiffness, attached with both lateral and rotational dampers at an intermediate point, is therefore considered in this study. The characteristic equation of the resulting system is formulated by assembling the dynamic stiffness from the two segments divided by the damper, which is subsequently solved using argument principle method. Dynamics of the controlled system is thus discussed in general through parametric analysis. For the case where the damper location is close to the anchorage, asymptotic solutions for complex frequency and damping ratio are provided; explicit formulas for determining the optimal damper coefficients are also derived. It is found that when the lateral and rotational damper coefficients are properly balanced, the proposed strategy can achieve up to 30 percent damping enhancement compared to the case with only the lateral damper, in practical cable bending stiffness range.

  6. Mitigation of electron attachment to oxygen in high pressure air plasmas by vibrational excitation (United States)

    Frederickson, K.; Lee, W.; Palm, P.; Adamovich, I. V.; Rich, J. W.; Lempert, W. R.


    A series of time resolved microwave attenuation measurements are performed of the electron number density of an electron beam generated, CO laser excited nonequilibrium O2/N2 plasma. Resonant absorption of infrared radiation from the CO laser produces the nonequilibrium state, in which the heavy species vibrational modes are disproportionately excited, compared to the rotational and translational modes (Tvib≈2000-3000K vs TR /T≈300K). It is shown that this results in an increase in the plasma free electron lifetime by two orders of magnitude compared to the unexcited cold gas, an effect which is ascribed to complete mitigation of rapid three-body electron attachment to molecular oxygen. A series of heavy species filtered pure rotational Raman scattering measurements are also presented, which exhibit minimal temperature change (+50K), indicating that the observed lifetime increase cannot be due to heavy-species thermal effects. Finally, computational modeling results infer an increase in the rate of O2- detachment by four to five orders of magnitude, compared to the equilibrium value.

  7. Double resonant absorption measurement of acetylene symmetric vibrational states probed with cavity ring down spectroscopy

    CERN Document Server

    Karhu, J; Vainio, M; Metsälä, M; Hoekstra, S; Halonen, L


    A novel mid-infrared/near-infrared double resonant absorption setup for studying infrared-inactive vibrational states is presented. A strong vibrational transition in the mid-infrared region is excited using an idler beam from a singly resonant continuous-wave optical parametric oscillator, to populate an intermediate vibrational state. High output power of the optical parametric oscillator and the strength of the mid-infrared transition result in efficient population transfer to the intermediate state, which allows measuring secondary transitions from this state with a high signal-to-noise ratio. A secondary, near-infrared transition from the intermediate state is probed using cavity ring down spectroscopy, which provides high sensitivity in this wavelength region. Due to the narrow linewidths of the excitation sources, the rovibrational lines of the secondary transition are measured with sub-Doppler resolution. The setup is used to access a previously unreported symmetric vibrational state of acetylene, $\

  8. A framework for the analysis of vibrations of structures with uncertain attachments (United States)

    Li, Shuo; Mace, Brian R.; Ferguson, Neil S.; Halkyard, Roger


    Attachments affect the dynamic response of an assembled structure. When engineers are modelling structures, small attachments will often not be included in the “bare” model, especially in the initial design stages. The location of these attachments might be poorly known, yet they affect the response of the structure. This paper considers how attachments jointed to the structure at uncertain points, can be included in the dynamic model of a structure. Two approaches are proposed. In the time domain, a combination of component mode synthesis, characteristic constraint modes and modal analysis gives a computationally efficient basis for subsequent analysis using, for example, Monte Carlo simulation. The frequency domain approach is based on assembly of frequency response functions of bare structure and attachment. Numerical examples of a beam and a plate with a point mass added at an uncertain location are considered and predictions compared with experiment results.

  9. A novel universal real-time PCR system using the attached universal duplex probes for quantitative analysis of nucleic acids

    Directory of Open Access Journals (Sweden)

    Wilson Zoe A


    Full Text Available Abstract Background Real-time PCR techniques are being widely used for nucleic acids analysis, but one limitation of current frequently employed real-time PCR is the high cost of the labeled probe for each target molecule. Results We describe a real-time PCR technique employing attached universal duplex probes (AUDP, which has the advantage of generating fluorescence by probe hydrolysis and strand displacement over current real-time PCR methods. AUDP involves one set of universal duplex probes in which the 5' end of the fluorescent probe (FP and a complementary quenching probe (QP lie in close proximity so that fluorescence can be quenched. The PCR primer pair with attached universal template (UT and the FP are identical to the UT sequence. We have shown that the AUDP technique can be used for detecting multiple target DNA sequences in both simplex and duplex real-time PCR assays for gene expression analysis, genotype identification, and genetically modified organism (GMO quantification with comparable sensitivity, reproducibility, and repeatability with other real-time PCR methods. Conclusion The results from GMO quantification, gene expression analysis, genotype identification, and GMO quantification using AUDP real-time PCR assays indicate that the AUDP real-time PCR technique has been successfully applied in nucleic acids analysis, and the developed AUDP real-time PCR technique will offer an alternative way for nucleic acid analysis with high efficiency, reliability, and flexibility at low cost.

  10. Double resonant absorption measurement of acetylene symmetric vibrational states probed with cavity ring down spectroscopy (United States)

    Karhu, J.; Nauta, J.; Vainio, M.; Metsälä, M.; Hoekstra, S.; Halonen, L.


    A novel mid-infrared/near-infrared double resonant absorption setup for studying infrared-inactive vibrational states is presented. A strong vibrational transition in the mid-infrared region is excited using an idler beam from a singly resonant continuous-wave optical parametric oscillator, to populate an intermediate vibrational state. High output power of the optical parametric oscillator and the strength of the mid-infrared transition result in efficient population transfer to the intermediate state, which allows measuring secondary transitions from this state with a high signal-to-noise ratio. A secondary, near-infrared transition from the intermediate state is probed using cavity ring-down spectroscopy, which provides high sensitivity in this wavelength region. Due to the narrow linewidths of the excitation sources, the rovibrational lines of the secondary transition are measured with sub-Doppler resolution. The setup is used to access a previously unreported symmetric vibrational state of acetylene, ν 1 + ν 2 + ν 3 + ν4 1 + ν5 - 1 in the normal mode notation. Single-photon transitions to this state from the vibrational ground state are forbidden. Ten lines of the newly measured state are observed and fitted with the linear least-squares method to extract the band parameters. The vibrational term value was measured to be at 9775.0018(45) cm-1, the rotational parameter B was 1.162 222(37) cm-1, and the quartic centrifugal distortion parameter D was 3.998(62) × 10-6 cm-1, where the numbers in the parenthesis are one-standard errors in the least significant digits.

  11. Remote vibration measurement: a wireless passive surface acoustic wave resonator fast probing strategy. (United States)

    Friedt, J-M; Droit, C; Ballandras, S; Alzuaga, S; Martin, G; Sandoz, P


    Surface acoustic wave (SAW) resonators can advantageously operate as passive sensors which can be interrogated through a wireless link. Amongst the practical applications of such devices, structural health monitoring through stress measurement and more generally vibration characteristics of mechanical structures benefit from the ability to bury such sensors within the considered structure (wireless and battery-less). However, measurement bandwidth becomes a significant challenge when measuring wideband vibration characteristics of mechanical structures. A fast SAW resonator measurement scheme is demonstrated here. The measurement bandwidth is limited by the physical settling time of the resonator (Q/π periods), requiring only two probe pulses through a monostatic RADAR-like electronic setup to identify the sensor resonance frequency and hence stress on a resonator acting as a strain gauge. A measurement update rate of 4800 Hz using a high quality factor SAW resonator operating in the 434 MHz Industrial, Scientific and Medical band is experimentally demonstrated.

  12. Local Environment and Interactions of Liquid and Solid Interfaces Revealed by Spectral Line Shape of Surface Selective Nonlinear Vibrational Probe

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shun-Li; Fu, Li; Chase, Zizwe A.; Gan, Wei; Wang, Hong-Fei


    Vibrational spectral lineshape contains important detailed information of molecular vibration and reports its specific interactions and couplings to its local environment. In this work, recently developed sub-1 cm-1 high-resolution broadband sum frequency generation vibrational spectroscopy (HR-BB-SFG-VS) was used to measure the -C≡N stretch vibration in the 4-n-octyl-4’-cyanobiphenyl (8CB) Langmuir or Langmuir-Blodgett (LB) monolayer as a unique vibrational probe, and the spectral lineshape analysis revealed the local environment and interactions at the air/water, air/glass, air/calcium fluoride and air/-quartz interfaces for the first time. The 8CB Langmuir or LB film is uniform and the vibrational spectral lineshape of its -C≡N group has been well characterized, making it a good choice as the surface vibrational probe. Lineshape analysis of the 8CB -C≡N stretch SFG vibrational spectra suggests the coherent vibrational dynamics and the structural and dynamic inhomogeneity of the -C≡N group at each interface are uniquely different. In addition, it is also found that there are significantly different roles for water molecules in the LB films on different substrate surfaces. These results demonstrated the novel capabilities of the surface nonlinear spectroscopy in characterization and in understanding the specific structures and chemical interactions at the liquid and solid interfaces in general.

  13. Free vibration analysis of elastically supported Timoshenko columns with attached masses by transfer matrix and finite element methods

    Indian Academy of Sciences (India)

    Oktay Demirdaǧ


    This paper deals with the free vibration of Timoshenko columns with attached masses having rotary inertia. The support of the model is elastically restrained against rotation. The concept of fixity factor is used to define the stiffness of the elastic connection relative to that of the column. The governing equation of the column elements is solved by applying the separation of variables method in the transfer matrix method (TMM) algorithm. The same problems are solved, also, by finite element method (FEM) algorithm in which the matrices in equation of motion are obtained for Timoshenko column, and the results are compared with the ones of TMM. The comparison graphs are presented in numerical analysis to show the effectiveness of the considered methods, and it is resulted that FEM gives closer results to TMM.

  14. Thermal insulation attaching means. [adhesive bonding of felt vibration insulators under ceramic tiles (United States)

    Leger, L. J. (Inventor)


    An improved isolation system is provided for attaching ceramic tiles of insulating material to the surface of a structure to be protected against extreme temperatures of the nature expected to be encountered by the space shuttle orbiter. This system isolates the fragile ceramic tiles from thermally and mechanically induced vehicle structural strains. The insulating tiles are affixed to a felt isolation pad formed of closely arranged and randomly oriented fibers by means of a flexible adhesive and in turn the felt pad is affixed to the metallic vehicle structure by an additional layer of flexible adhesive.

  15. Exact free vibration of multi-step Timoshenko beam system with several attachments (United States)

    Farghaly, S. H.; El-Sayed, T. A.


    This paper deals with the analysis of the natural frequencies, mode shapes of an axially loaded multi-step Timoshenko beam combined system carrying several attachments. The influence of system design and the proposed sub-system non-dimensional parameters on the combined system characteristics are the major part of this investigation. The effect of material properties, rotary inertia and shear deformation of the beam system for each span are included. The end masses are elastically supported against rotation and translation at an offset point from the point of attachment. A sub-system having two degrees of freedom is located at the beam ends and at any of the intermediate stations and acts as a support and/or a suspension. The boundary conditions of the ordinary differential equation governing the lateral deflections and slope due to bending of the beam system including the shear force term, due to the sub-system, have been formulated. Exact global coefficient matrices for the combined modal frequencies, the modal shape and for the discrete sub-system have been derived. Based on these formulae, detailed parametric studies of the combined system are carried out. The applied mathematical model is valid for wide range of applications especially in mechanical, naval and structural engineering fields.

  16. The use of enamel matrix derivative (Emdogain) for improvement of probing attachment level of the autotransplanted teeth. (United States)

    Hamamoto, Yoshioki; Takahashi, Kouji; Sakurai, Hiromasa; Akiba, Katsumi; Izumi, Naoya; Kanoh, Hiroyuki; Yoshizawa, Michiko; Saito, Chikara


    The enamel matrix derivative (EMD, Emdogain) was used for the purpose to obtain the periodontal regeneration on the denuded root-surfaces of the donor teeth in two cases of the immediate tooth-transplantation. The root-surfaces at the cervical portion of the teeth were denuded because of extrusion. The healthy periodontium of each tooth remained at the apical portion of the roots. The denuded root-surfaces were cleansed before extraction. Then, the donor teeth were gently extracted with forceps, administered EMD, and transplanted so that the denuded surfaces were covered by gingival flaps. After the transplantation, the mean probing attachment level (PAL) improved 3.2 mm and 1.5 mm, respectively. The mean probing pocket depth was within normal level. The actual supporting areas of the roots of the transplanted teeth increased and the teeth worked as the abutments of prosthetic bridges.

  17. Probing QED and fundamental constants through laser spectroscopy of vibrational transitions in HD+

    CERN Document Server

    Biesheuvel, J; Hilico, L; Eikema, K S E; Ubachs, W; Koelemeij, J C J


    The simplest molecules in nature, molecular hydrogen ions in the form of H2+ and HD+, provide an important benchmark system for tests of quantum electrodynamics in complex forms of matter. Here, we report on such a test based on a frequency measurement of a vibrational overtone transition in HD+ by laser spectroscopy. We find that the theoretical and experimental frequencies are equal to within 0.6(1.1) parts per billion, which represents the most stringent test of molecular theory so far. Our measurement not only confirms the validity of high-order quantum electrodynamics in molecules, but also enables the long predicted determination of the proton-to-electron mass ratio from a molecular system, as well as improved constraints on hypothetical fifth forces and compactified higher dimensions at the molecular scale. With the perspective of comparisons between theory and experiment at the 0.01 part-per-billion level, our work demonstrates the potential of molecular hydrogen ions as a probe of fundamental physica...

  18. Formation and properties of electroactive fullerene based films with a covalently attached ferrocenyl redox probe

    Energy Technology Data Exchange (ETDEWEB)

    Wysocka-Zolopa, Monika [Institute of Chemistry, University of Bialystok, Hurtowa 1, 15-399 Bialystok (Poland); Winkler, Krzysztof, E-mail: [Institute of Chemistry, University of Bialystok, Hurtowa 1, 15-399 Bialystok (Poland); Caballero, Ruben [Instituto de Nanociencia, Nanotecnologia y Materiales Moleculares (INAMOL), Universidad de Castilla-La Mancha, 45071 Toledo (Spain); Langa, Fernando, E-mail: [Instituto de Nanociencia, Nanotecnologia y Materiales Moleculares (INAMOL), Universidad de Castilla-La Mancha, 45071 Toledo (Spain)


    Highlights: > Formation of redox active films of ferrocene derivatives of C{sub 60} and palladium. > Fullerene moieties are covalently bonded to palladium atoms to form a polymeric network. > Electrochemical activity at both positive and negative potentials. > Charge transfer processes accompanied by transport of supporting electrolyte to and from the polymer layers. - Abstract: Redox active films have been produced via electrochemical reduction in a solution containing palladium(II) acetate and ferrocene derivatives of C{sub 60} (Fc-C{sub 60} and bis-Fc-C{sub 60}). In these films, fullerene moieties are covalently bonded to palladium atoms to form a polymeric network. Fc-C{sub 60}/Pd and bis-Fc-C{sub 60}/Pd films form uniform and relatively smooth layers on the electrode surface. These films are electrochemically active in both the positive and negative potential regions. At negative potentials, reduction of fullerene moiety takes place resulting in voltammetric behavior resembles typical of conducting polymers. In the positive potential range, oxidation of ferrocene is responsible for the formation of a sharp and symmetrical peak on the voltammograms. In this potential range, studied films behave as typical redox polymers. The charge associated with the oxidation process depends on the number of ferrocene units attached to the C{sub 60} moiety. Oxidation and reduction of these redox active films are accompanied by transport of supporting electrolyte to and from the polymer layer. Films also show a higher permeability to anions than to cations.

  19. Cβ-H stretching vibration as a new probe for conformation of n-propanol in gaseous and liquid states. (United States)

    Yu, Yuanqin; Wang, Yuxi; Hu, Naiyin; Lin, Ke; Zhou, Xiaoguo; Liu, Shilin


    The development of potential probes to identify molecular conformation is essential in organic and biological chemistry. In this work, we investigated a site-specific C-H stretching vibration as a conformational probe for a model compound, 1,1,3,3,3-deuterated n-propanol (CD3CH2CD2OH), using stimulated photoacoustic Raman spectroscopy in the gas phase and conventional spontaneous Raman spectroscopy in the liquid state. Along with quantum chemistry calculations, the experiment shows that the CH2 symmetric stretching mode at the β-carbon position is very sensitive to the conformational structure of n-propanol and can serve as a new probe for all five of its conformers. Compared with the O-H stretching vibration, a well-established conformational sensor for n-propanol, the Cβ-H stretching vibration presented here shows better conformational resolution in the liquid state. Furthermore, using this probe, we investigated the conformational preference of n-propanol in pure liquid and in dilute water solution. It is revealed that in pure liquid, n-propanol molecules prefer the trans-OH conformation, and in dilute water solution, this preference is enhanced, indicating that the water molecules play a role of further stabilizing the trans-OH n-propanol conformers. This leads to conformational evolution that n-propanol molecules with gauche-OH structure are transferred to the trans-OH structure upon diluting with water. These results not only provide important information on structures of n-propanol in different environments, but also demonstrate the potential of the C-H stretching vibration as a new tool for conformational analysis. This is especially important when considering that hydrocarbon chains are structural units in organic and biological molecules.

  20. Measuring Work Functions Of "Dirty" Surfaces With A Vibrating Capacitive Probe (United States)

    Yost, William T.


    Apparatus measures work function of possibly contaminated surface of specimen of metal or other electrically conductive material. Measures work function of specimen indirectly, by vibrating capacitive measurement of contact potential. Work function of specimen affected by microstructure and by contamination.

  1. Molecular photoionization as a probe of vibrational{endash}rotational{endash}electronic correlations

    Energy Technology Data Exchange (ETDEWEB)

    Rao, R.M. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Poliakoff, E.D. [Department of Chemistry and Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Wang, K.; McKoy, V. [Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125 (United States)


    We determine the rotationally state-resolved 2{sigma}{sub {ital u}}{sup {minus}1} photoionization of N{sub 2} into alternative vibrational channels as a function of energy over a 200 eV range. Experiment and theory reveal that Cooper minima highlight the coupling between electronic, vibrational, and rotational degrees of freedom over this very wide range. {copyright} {ital 1996 American Institute of Physics.}

  2. Probing anharmonic properties of nuclear surface vibration by heavy-ion fusion reactions

    CERN Document Server

    Takigawa, N; Kuyucak, S


    Describing fusion reactions between ^{16}O and ^{154}Dy and, between ^{16}O and ^{144}Sm by the $sd-$ and $sdf-$ interacting boson model, we show that heavy-ion fusion reactions are strongly affected by anharmonic properties of nuclear surface vibrations and nuclear shape, and thus provide a powerful method to study details of nuclear structure and dynamics.

  3. Vibrational excitons in ionophores: Experimental probes for quantum coherence-assisted ion transport and selectivity in ion channels

    CERN Document Server

    Ganim, Ziad; Vaziri, Alipasha


    Despite a large body of work, the exact molecular details underlying ion-selectivity and transport in the potassium channel have not been fully laid to rest. One major reason has been the lack of experimental methods that can probe these mechanisms dynamically on their biologically relevant time scales. Recently it was suggested that quantum coherence and its interplay with thermal vibration might be involved in mediating ion-selectivity and transport. In this work we present an experimental strategy for using time resolved infrared spectroscopy to investigate these effects. We show the feasibility by demonstrating the IR absorption and Raman spectroscopic signatures of potassium binding model molecules that mimic the transient interactions of potassium with binding sites of the selectivity filter during ion conduction. In addition to guide our experiments on the real system we have performed molecular dynamic-based simulations of the FTIR and 2DIR spectra of the entire KcsA complex, which is the largest comp...

  4. Dynamic characterization of small fibers based on the flexural vibrations of a piezoelectric cantilever probe (United States)

    Zhang, Xiaofei; Ye, Xuan; Li, Xide


    In this paper, we present a cantilever-probe system excited by a piezoelectric actuator, and use it to measure the dynamic mechanical properties of a micro- and nanoscale fiber. Coupling the fiber to the free end of the cantilever probe, we found the dynamic stiffness and damping coefficient of the fiber from the resonance frequency and the quality factor of the fiber-cantilever-probe system. The properties of Bacillus subtilis fibers measured using our proposed system agreed with tensile measurements, validating our method. Our measurements show that the piezoelectric actuator coupled to cantilever probe can be made equivalent to a clamped cantilever with an effective length, and calculated results show that the errors of measured natural frequency of the system can be ignored if the coupled fiber has an inclination angle of alignment of less than 10°. A sensitivity analysis indicates that the first or second resonant mode is the sensitive mode to test the sample’s dynamic stiffness, while the damping property has different sensitivities for the first four modes. Our theoretical analysis demonstrates that the double-cantilever probe is also an effective sensitive structure that can be used to perform dynamic loading and characterize dynamic response. Our method has the advantage of using amplitude-frequency curves to obtain the dynamic mechanical properties without directly measuring displacements and forces as in tensile tests, and it also avoids the effects of the complex surface structure and deformation presenting in contact resonance method. Our method is effective for measuring the dynamic mechanical properties of fiber-like one-dimensional (1D) materials.

  5. An analytical model for the propagation of bending waves on a plant stem due to vibration of an attached insect. (United States)

    Miles, R N


    A mathematical model is presented to examine the propagation of bending waves on a plant stem that are induced by vibratory excitation from an attached insect. This idealized model represents the insect body as a mass and the legs as a linear spring along with a general time-varying force that is assumed to act in parallel with the spring. The spring connects the mass to a stem modeled as a beam having uniform geometric and material properties. The linearly elastic beam is assumed to undergo pure vibratory bending and to be infinitely long in each direction. The equations that govern the insect-induced, coupled motions of both the beam and the mass are solved for arbitrary time varying forces produced by the insect's legs. Solutions for the frequency response indicate that the response is dominated by frequency components near the natural resonant frequency of the attached insect while at higher frequencies the amplitude of the response is strongly influenced only by the properties of the stem.

  6. 2D IR spectroscopy of histidine: probing side-chain structure and dynamics via backbone amide vibrations. (United States)

    Ghosh, Ayanjeet; Tucker, Matthew J; Gai, Feng


    It is well known that histidine is involved in many biological functions due to the structural versatility of its side chain. However, probing the conformational transitions of histidine in proteins, especially those occurring on an ultrafast time scale, is difficult. Herein we show, using a histidine dipeptide as a model, that it is possible to probe the tautomer and protonation status of a histidine residue by measuring the two-dimensional infrared (2D IR) spectrum of its amide I vibrational transition. Specifically, for the histidine dipeptide studied, the amide unit of the histidine gives rise to three spectrally resolvable amide I features at approximately 1630, 1644, and 1656 cm(-1), respectively, which, based on measurements at different pH values and frequency calculations, are assigned to a τ tautomer (1630 cm(-1) component) and a π tautomer with a hydrated (1644 cm(-1) component) or dehydrated (1656 cm(-1) component) amide. Because of the intrinsic ultrafast time resolution of 2D IR spectroscopy, we believe that the current approach, when combined with the isotope editing techniques, will be useful in revealing the structural dynamics of key histidine residues in proteins that are important for function.

  7. Dynamic acousto-elastic test using continuous probe wave and transient vibration to investigate material nonlinearity. (United States)

    Eiras, J N; Vu, Q A; Lott, M; Payá, J; Garnier, V; Payan, C


    This study demonstrates the feasibility of the dynamic acousto-elastic effect of a continuous high frequency wave for investigating the material nonlinearity upon transient vibration. The approach is demonstrated on a concrete sample measuring 15×15×60cm(3). Two ultrasonic transducers (emitter and receiver) are placed at its middle span. A continuous high frequency wave of 500kHz propagates through the material and is modulated with a hammer blow. The position of the hammer blow on the sample is configured to promote the first bending mode of vibration. The use of a continuous wave allows discrete time extraction of the nonlinear behavior by a short-time Fourier transform approach, through the simultaneous comparison of a reference non-modulated signal and an impact-modulated signal. The hammer blow results in phase shifts and variations of signal amplitude between reference and perturbed signals, which are driven by the resonant frequency of the sample. Finally, a comprehensive analysis of the relaxation mechanisms (modulus and attenuation recovery) is conducted to untangle the coupled fast and slow hysteretic effects.

  8. Interfacial Water Structure in Langmuir Monolayer and Gibbs Layer Probed by Sum Frequency Generation Vibrational Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    张贞; 郭源


    Langmuir monolayer and Gibbs layer exhibit surface-active properties and it can be used as simple model systems to investigate the physicochemical properties of biological membranes. In this report, we presented the OH stretching vibration of H2O in the 4"-n-pentyl-4-cyano-p-terphenyl (5CT), nonadecanenitrile (C18CN) Langmuir monolayer and compared them with CH3CN Gibbs layer at the air/water interface with polarization SFG-VS. This study demonstrated that the hydrogen bond network is different in the Langmuir monolayer of 5CT, C18CN from CH3CN Gibbs layer at the air/water interface which showed two different water structures on the different surface layer. The results provided a deeper insight into understanding the hydrogen bond on the interfaces.

  9. Using vibrational branching ratios to probe initial and final state effects in molecular photoionization

    Energy Technology Data Exchange (ETDEWEB)

    Lucchese, Robert R [Department of Chemistry, Texas A and M University, College Station, TX 77843-3255 (United States); Bozek, John D [Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Das, Aloke [Indian Institute of Science Education and Research, Pune, Maharashtra 411008 (India); Poliakoff, E D, E-mail: lucchese@mail.chem.tamu.ed [Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803 (United States)


    Recent computed and experimental results for ICN, BF{sub 3} and C{sub 6}F{sub 6} will be presented. In ICN we consider the ionization leading to the X{sup 2} {Pi}{sub 1/2,3/2} states of ICN{sup +}. We show how the geometry dependence of the initial state orbital can be studied using vibrational branching ratios. In C{sub 6}F{sub 6}, we consider the excitation of the effects of two prominent shape resonances on the symmetric stretching modes in the photoionization leading to the C {sup 3}B{sub 2u} state of the ion. In BF{sub 3}, the excitation of both the symmetric stretching and the degenerate asymmetric stretching modes are considered in the photoionization leading to the E{sup 2}A{sub 1}' state of the ion.

  10. Probing elasticity at the nanoscale: Terahertz acoustic vibration of small metal nanoparticles. (United States)

    Juvé, Vincent; Crut, Aurélien; Maioli, Paolo; Pellarin, Michel; Broyer, Michel; Del Fatti, Natalia; Vallée, Fabrice


    The acoustic response of surface-controlled metal (Pt) nanoparticles is investigated in the small size range, between 1.3 and 3 nm (i.e., 75-950 atoms), using time-resolved spectroscopy. Acoustic vibration of the nanoparticles is demonstrated, with frequencies ranging from 1.1 to 2.6 THz, opening the way to the development of THz acoustic resonators. The frequencies, measured with a noncontact optical method, are in excellent agreement with the prediction of a macroscopic approach based on the continuous elastic model, together with the bulk material elastic constants. This demonstrates the validity of this model at the nanoscale and the weak impact of size reduction on the elastic properties of a material, even for nanoparticles formed by less than 100 atoms.

  11. Vibrational sensitivity of the subgenual organ complex in female Sipyloidea sipylus stick insects in different experimental paradigms of stimulus direction, leg attachment, and ablation of a connective tibial sense organ. (United States)

    Strauß, Johannes; Lakes-Harlan, Reinhard


    We document the sensitivity to sinusoidal vibrations for chordotonal organs in the stick insect tibia (Sipyloidea sipylus). In the tibia, the scolopidial subgenual organ (~40 scolopidial sensilla), distal organ (~20 scolopidial sensilla), and distal tibial chordotonal organ (~7 scolopidial sensilla) are present. We study the sensitivity of tibial sensory organs in all leg pairs to vibration stimuli as sensory thresholds by recording summed action potentials from Nervus cruris in the femur. The tibia was stimulated with a minishaker delivering vibrational stimuli. Because different experimental procedures may affect the vibration sensitivity, we here analysed possible effects of different experimental conditions: (1) the stimulus direction delivered in either horizontal or vertical direction to the leg; (2) recording responses only from the subgenual organ complex after ablation of the distal tibial chordotonal organ, and (3) the attachment of the leg to the minishaker by plastilin, beeswax-colophony, or freely standing legs. The tibial scolopidial organs give summed responses to vibration stimuli with highest sensitivity between 500 and 1000Hz for all leg pairs. In the different experimental series, we find that (1) thresholds were influenced by stimulation direction with lower thresholds in response to vertical vibrations, (2) ablating the distal tibial chordotonal organ by cutting the distal-most tibia did not change the summed sensory thresholds significantly, and (3) the attachment material between legs and the minishaker (plastilin or beeswax-colophony mixture) did not significant influence the sensory thresholds against free-standing tarsi. The distal tibial chordotonal organ is a connective chordotonal organ attached to a tendon and is likely a proprioceptive organ. These results emphasise that vibrational thresholds are mainly direction-sensitive. Thus, the direction of stimulus delivery during electrophysiological recordings is relevant for comparisons of

  12. Wave packet dynamics of potassium dimers attached to helium nanodroplets


    Claas, P.; Droppelmann, G.; Schulz, C. P.; Mudrich, M.; Stienkemeier, F.


    The dynamics of vibrational wave packets excited in K$_2$ dimers attached to superfluid helium nanodroplets is investigated by means of femtosecond pump-probe spectroscopy. The employed resonant three-photon-ionization scheme is studied in a wide wavelength range and different pathways leading to K$^+_2$-formation are identified. While the wave packet dynamics of the electronic ground state is not influenced by the helium environment, perturbations of the electronically excited states are obs...

  13. Lanthanide tris(β-diketonates) as useful probes for chirality determination of biological amino alcohols in vibrational circular dichroism: ligand to ligand chirality transfer in lanthanide coordination sphere. (United States)

    Miyake, Hiroyuki; Terada, Keiko; Tsukube, Hiroshi


    A series of lanthanide tris(β-diketonates) functioned as useful chirality probes in the vibrational circular dichroism (VCD) characterization of biological amino alcohols. Various chiral amino alcohols induced intense VCD signals upon ternary complexation with racemic lanthanide tris(β-diketonates). The VCD signals observed around 1500 cm(-1) (β-diketonate IR absorption region) correlated well with the stereochemistry and enantiomeric purity of the targeted amino alcohol, while the corresponding monoalcohol, monoamine, and diol substrates induced very weak VCD signals. The high-coordination number and dynamic property of the lanthanide complex offer an effective chirality VCD probing of biological substrates.

  14. Calculations of Nonlinear Wave-Packet Interferometry Signals in the Pump-Probe Limit as Tests for Vibrational Control over Electronic Excitation Transfer

    CERN Document Server

    Biggs, Jason D


    The preceding paper describes a strategy for externally influencing the course of short-time electronic excitation transfer (EET) in molecular dimers and observing the process by nonlinear wave-packet interferometry (nl-WPI). Within a sample of isotropically oriented dimers having a specified internal geometry, a vibrational mode internal to the acceptor chromophore can be preferentially driven by electronically nonresonant impulsive stimulated Raman (or resonant infrared) excitation with a short polarized control pulse. A subsequent electronically resonant polarized pump then preferentially excites the donor, and EET ensues. Here we test both the control strategy and its spectroscopic investigation-with some sacrifice of amplitude-level detail-by calculating the pump-probe difference signal. That signal is the limiting case of the control-influenced nl-WPI signal in which the two pulses in the pump pulse-pair coincide, as do the two pulses in the probe pulse-pair. We present calculated pump-probe difference ...

  15. Structure-Dependent Vibrational Dynamics of Mg(BH4)2 Polymorphs Probed with Neutron Vibrational Spectroscopy and First-Principles Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Dimitrievska, Mirjana; White, James L.; Zhou, Wei; Stavila, Vitalie; Klebanoff, Leonard E.; Udovic, Terrence J.


    The structure-dependent vibrational properties of different Mg(BH4)2 polymorphs (..alpha.., ..beta.., ..gamma.., and phases) were investigated with a combination of neutron vibrational spectroscopy (NVS) measurements and density functional theory (DFT) calculations, with emphasis placed on the effects of the local structure and orientation of the BH4- anions. DFT simulations closely match the neutron vibrational spectra. The main bands in the low-energy region (20-80 meV) are associated with the BH4- librational modes. The features in the intermediate energy region (80-120 meV) are attributed to overtones and combination bands arising from the lower-energy modes. The features in the high-energy region (120-200 meV) correspond to the BH4- symmetric and asymmetric bending vibrations, of which four peaks located at 140, 142, 160, and 172 meV are especially intense. There are noticeable intensity distribution variations in the vibrational bands for different polymorphs. This is explained by the differences in the spatial distribution of BH4- anions within various structures. An example of the possible identification of products after the hydrogenation of MgB2, using NVS measurements, is presented. These results provide fundamental insights of benefit to researchers currently studying these promising hydrogen-storage materials.

  16. Positron-attachment to small molecules: Vibrational enhancement of positron affinities with configuration interaction level of multi-component molecular orbital approach

    Energy Technology Data Exchange (ETDEWEB)

    Tachikawa, Masanori [Quantum Chemistry Division, Graduate School of NanoBioScience, Yokohama City University, 22-2 Seto, Kanazawa, Yokohama 236-0027 (Japan)


    To theoretically demonstrate the binding of a positron to small polarized molecules, we have calculated the vibrational averaged positron affinity (PA) values along the local vibrational contribution with the configuration interaction level of multi-component molecular orbital method. This method can take the electron-positron correlation contribution into account through single electronic - single positronic excitation configurations. The PA values are enhanced by including the local vibrational contribution from vertical PA values due to the anharmonicity of the potential.

  17. Probing highly-obscured galaxy nuclei with vibrationally excited HCN - Extreme luminosity densities inside self-absorbed v=0 HCN and HCO+

    CERN Document Server

    Aalto, S; Gonzalez-Alfonso, E; Muller, S; Sakamoto, K; Fuller, G A; Garcia-Burillo, S; van der Werf, P; Neri, R; Spaans, M; Combes, F; Viti, S; Muehle, S; Armus, L; Evans, A; Sturm, E; Cernicharo, J; Henkel, C; Greve, T R


    We present high resolution (0."4) IRAM PdBI and ALMA mm and submm observations of the (Ultra) Luminous Infrared Galaxies ((U)LIRGs) IRAS17208-0014, Arp220, IC860 and Zw049.057 that reveal intense line emission from vibrationally excited (v2=1) J=3-2 and 4-3 HCN. The emission is emerging from buried, compact (r5e13 Lsun/kpc2. These nuclei are likely powered by accreting supermassive black holes (SMBHs) and/or hot (>200 K) extreme starbursts. Vibrational, v2=1, lines of HCN are excited by intense 14 micron mid-infrared emission and are excellent probes of the dynamics, masses and physical conditions of (U)LIRG nuclei when H2 column densities exceed 1e24 cm-2. It is clear that these lines open up a new interesting avenue to gain access to the most obscured AGNs and starbursts. Vibrationally excited HCN acts as a proxy for the absorbed mid-infrared emission from the embedded nuclei, which allows for reconstruction of the intrinsic, hotter dust SED. In contrast, the ground vibrational state (v=0), J=3-2 and 4-3 ro...

  18. Fast contactless vibrating structure characterization using real time field programmable gate array-based digital signal processing: demonstrations with a passive wireless acoustic delay line probe and vision. (United States)

    Goavec-Mérou, G; Chrétien, N; Friedt, J-M; Sandoz, P; Martin, G; Lenczner, M; Ballandras, S


    Vibrating mechanical structure characterization is demonstrated using contactless techniques best suited for mobile and rotating equipments. Fast measurement rates are achieved using Field Programmable Gate Array (FPGA) devices as real-time digital signal processors. Two kinds of algorithms are implemented on FPGA and experimentally validated in the case of the vibrating tuning fork. A first application concerns in-plane displacement detection by vision with sampling rates above 10 kHz, thus reaching frequency ranges above the audio range. A second demonstration concerns pulsed-RADAR cooperative target phase detection and is applied to radiofrequency acoustic transducers used as passive wireless strain gauges. In this case, the 250 ksamples/s refresh rate achieved is only limited by the acoustic sensor design but not by the detection bandwidth. These realizations illustrate the efficiency, interest, and potentialities of FPGA-based real-time digital signal processing for the contactless interrogation of passive embedded probes with high refresh rates.

  19. Interactions of nitrogen and hydrogen with various 1D and 3D carbon materials probed via in-situ vibrational spectroscopy (United States)

    Ray, Paramita

    Nanostructured carbon materials are perhaps the most widely studied adsorbents, and cryogenic nitrogen adsorption is likely the most common method to assess textural properties of adsorbents. Yet, in-situ vibrational spectroscopic studies of nitrogen's interactions with three nanostructured carbon materials have provided new insight into carbon-nitrogen interactions. In this dissertation I present the work of 2 projects: (i) Study of the interaction of N2 with different carbon geometries at a molecular level and (ii) exploration of novel C-H interactions on carbon materials via mechano-chemistry. Both of these projects utilize in-situ Raman spectroscopy for exploring gas-surface interactions. Chapters 2 and 3 explore the interaction of molecular Nitrogen on carbon surfaces. With complementary theoretical studies and systematic experimental studies at various temperatures and pressures for different surfaces, I demonstrate how the spectroscopic peak features of N2 gives an indication of gas-surface binding energy, pore structure, and surface chemistry. Using 1D and 3D carbon architectures, spectroscopic perturbation of N2 is probed as a function of adsorption potential and pore dimension, and the spectroscopic response is mapped to the cryogenic volumetric adsorption isotherms. Whereas the latter required multiple days and ˜100 mg of sample, the spectroscopic technique provided similar structural information in the matter of a few hours for a few micrograms of the sample. It is anticipated that the development of the site-specific spectroscopic technique will advance the understanding of adsorbent geometry versus chemical functionality in a way not possible with deconstruction of bulk gas adsorption measurements of pore dimension, surface area, and diffusivity. The second project probed mechanochemical means to polymerize aromatics and hydro-aromatics in the presence of hydrogen in an attempt to form localized carbon cages that trap hydrogen. Interesting aspects of

  20. Probing the structure and nano-scale mechanical properties of polymer surfaces with scanning force microscopy and sum frequency vibrational spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gracias, David Hugo [Univ. of California, Berkeley, CA (United States)


    Scanning Force Microscopy (SFM) has been used to quantitatively measure the elastic modulus, friction and hardness of polymer surfaces with special emphasis on polyethylene and polypropylene. In the experiments, tips of different radii of curvature ranging from 20 nm to 1000 nm have been used and the high pressure applied by the SFM have been observed to affect the values obtained in the measurements. The contact of the SFM tip with the polymer surface is explained by fitting the experimental curves to theoretical predictions of contact mechanics. Sum Frequency Generation (SFG) Vibrational Spectroscopy has been used to measure vibrational spectra of polymer surfaces in the vibrational range of 2700 to 3100 cm-1. Strong correlations are established between surface chemistry and surface structure as probed by SFG and mechanical properties measured by SFM on the surfaces. In these studies segregation of low surface energy moieties, from the bulk of the polymer to the surface have been studied. It was found that surface segregation occurs in miscible polymer blends and a small concentration of surface active polymer can be used to totally modify the surface properties of the blend. A novel high vacuum SFM was built to do temperature dependent measurements of mechanical changes occurring at the surface of polypropylene during the glass transition of the polymer. Using this instrument the modulus and friction of polypropylene was measured in the range of room temperature to ˜-60°C. An increase in the ordering of the backbone of the polymer chains below the glass transition measured by SFG correlates well with the increase in modulus measured on the same surface with SFM. Friction measurements have been done on polyethylene with three different instruments by applying loads ranging from nN to sub newton i.e. over eight orders of magnitude. Pressure and contact area effects were observed to play a significant role in determining the frictional response of the polymer

  1. Product Attachment

    NARCIS (Netherlands)

    Mugge, R.


    The topic of this doctoral research is the concept of product attachment for ordinary consumer durables. Product attachment is defined as the strength of the emotional bond a consumer experiences with a specific product. Specifically, the research investigated how this bond develops over time and th

  2. Optically probing Al—O and O—H vibrations to characterize water adsorption and surface reconstruction on α-alumina: An experimental and theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Yujin, E-mail:; Kirsch, Harald; Wolf, Martin; Campen, R. Kramer, E-mail: [Fritz Haber Institute of the Max Planck Society, 14195 Berlin (Germany); Wirth, Jonas; Saalfrank, Peter [Institute of Chemistry, University of Potsdam, 14476 Potsdam OT Golm (Germany)


    Oxide/water interfaces are ubiquitous in a wide variety of applications and the environment. Despite this ubiquity, and attendant decades of study, gaining molecular level insight into water/oxide interaction has proven challenging. In part, this challenge springs from a lack of tools to concurrently characterize changes in surface structure (i.e., water/oxide interaction from the perspective of the solid) and O—H population and local environment (i.e., water/oxide interaction from the water perspective). Here, we demonstrate the application of surface specific vibrational spectroscopy to the characterization of the interaction of the paradigmatic α-Al{sub 2}O{sub 3}(0001) surface and water. By probing both the interfacial Al—O (surface phonon) and O—H spectral response, we characterize this interaction from both perspectives. Through electronic structure calculation, we assign the interfacial Al—O response and rationalize its changes on surface dehydroxylation and reconstruction. Because our technique is all-optical and interface specific, it is equally applicable to oxide surfaces in vacuum, ambient atmospheres and at the solid/liquid interface. Application of this approach to additional alumina surfaces and other oxides thus seems likely to significantly expand our understanding of how water meets oxide surfaces and thus the wide variety of phenomena this interaction controls.

  3. Detailed study of dissipative quantum dynamics of K-2 attached to helium nanodroplets

    CERN Document Server

    Schlesinger, Martin


    We thoroughly investigate vibrational quantum dynamics of dimers attached to He droplets motivated by recent measurements with K-2 [1]. For those femtosecond pump-probe experiments, crucial observed features are not reproduced by gas phase calculations but agreement is found using a description based on dissipative quantum dynamics, as briefly shown in [2]. Here we present a detailed study of the influence of possible effects induced by the droplet. The helium droplet causes electronic decoherence, shifts of potential surfaces, and relaxation of wave packets in attached dimers. Moreover, a realistic description of (stochastic) desorption of dimers off the droplet needs to be taken into account. Step by step we include and study the importance of these effects in our full quantum calculation. This allows us to reproduce and explain all major experimental findings. We find that desorption is fast and occurs already within 2-10 ps after electronic excitation. A further finding is that slow vibrational motion in ...

  4. The Comparison Analysis of Two Typical Torsional Vibration Viscosity Probe Sensitivity%两种典型扭振式粘度测头的灵敏度对比分析

    Institute of Scientific and Technical Information of China (English)

    孙培元; 赵美蓉; 马金玉


    针对扭振式粘度测量中,不同测头形状所受到的粘性力不同,进而对测量灵敏度产生影响的问题,基于FBG扭矩微振粘度测量原理,研究柱形与球面两种测头装置的测量精度及灵敏度.通过对不同形状的测头建立数学模型,得出相应的电压-粘度关系式,在实验室环境下通过标定实验确定待定系数,并比较两种测头的测量特性.实验数据表明,柱形测头的测量精度及灵敏度高于球面测头,验证了理论分析.同时,对测量误差来源进行了分析,为后续研究提供了理论基础.%Aiming at the problems in torsional vibration viscosity measurement that sensitivity is influenced by different shapes of probe subjected to different viscous force, the measuring accuracy and sensitivity of cylindrical probe and spherical probe are studied according to the principle of viscosity measurement based on FBG micro-torsional vibration. Through the mathematical model built for different probes, corresponding voltage-viscosity formulas are derived,then in laboratory environment,the undetermined coefficient is got from calibration experiment,and the measuring characteristics are compared between the two probes. The experimental data shows that cylindrical probe is more accurate and more sensitive than spherical probe,which verifying the theoretical analysis. At the same time,we also analysis the measuring error sources to provide theoretical basis for the further study.

  5. Vibration control of multi-degrees-of-freedom system with dynamic absorbers based on power flow

    Institute of Scientific and Technical Information of China (English)

    WANG Quanjuan; HUANG Wenhua; XIA Songbo; LI Jimin; SUN Zhizhuo


    In accordance with a multiple degrees of freedom vibration system with dynamicvibration absorbers (DVAs), an equivalent admittance matrix and the power flows input majorstructure and minor structure are deduced on the basis of the theories of structure mobility.Furthermore, regarding the net power flow of main vibration system as the controlled object,probed into are the single and multiple model controls of multi-degrees-of-freedom system withone or several absorbers attached. And the control mechanism and effect of dynamic vibrationabsorbers are revealed.

  6. Facile sonochemical synthesis and morphology control of CePO{sub 4} nanostructures via an oriented attachment mechanism: Application as luminescent probe for selective sensing of Pb{sup 2+} ion in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Shiralizadeh Dezfuli, Amin [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Ganjali, Mohammad Reza, E-mail: [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Biosensor Research Center, Endocrinology and Metabolism Molecular–Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Norouzi, Parviz [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Biosensor Research Center, Endocrinology and Metabolism Molecular–Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)


    CePO{sub 4} nanostructures with hexagonal phase were controllably synthesized using Ce(NO{sub 3}){sub 3} reaction with NH{sub 4}H{sub 2}PO{sub 4} through a sonochemical method by simply varying the reaction conditions. By adding ethanol and polyethylene glycol (PEG), coral-reef nanostructures (CRNs) were synthesized and controlling over pH caused to nanorods/nanowires. Oriented attachment (OA) is proposed as dominant mechanism on the growth of nanostructures which is in competition with Ostwald ripening (OR). The crystal structure and morphology of the nanostructures were characterized by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM), respectively. The luminescent properties of CePO{sub 4} with different morphologies have been studied. Among the nanostructures, nanoparticles with the highest intensity of fluorescent have been used as luminescent probe for selective sensing of Pb{sup 2+} ion in aqueous solution. - Highlights: • Facile sonochemical method has been used for synthesis of CePO{sub 4} nanostructures. • Coral-reef as a new morphology of nanostructures is introduced. • CePO{sub 4} NPs have been used as luminescent probe for selective sensing of Pb{sup 2+} ion.

  7. 2008 Vibrational Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Philip J. Reid


    The conference focuses on using vibrational spectroscopy to probe structure and dynamics of molecules in gases, liquids, and interfaces. The goal is to bring together a collection of researchers who share common interests and who will gain from discussing work at the forefront of several connected areas. The intent is to emphasize the insights and understanding that studies of vibrations provide about a variety of systems.

  8. Probing the Vibrational Spectroscopy of the Deprotonated Thymine Radical by Photodetachment and State-Selective Autodetachment Photoelectron Spectroscopy via Dipole-Bound States (United States)

    Huang, Dao-Ling; Zhu, Guo-Zhu; Wang, Lai-Sheng


    Deprotonated thymine can exist in two different forms, depending on which of its two N sites is deprotonated: N1[T-H]^- or N3[T-H]^-. Here we report a photodetachment study of the N1[T-H]^- isomer cooled in a cryogenic ion trap and the observation of an excited dipole-bound state. Eighteen vibrational levels of the dipole-bound state are observed, and its vibrational ground state is found to be 238 ± 5 wn below the detachment threshold of N1[T-H]^-. The electron affinity of the deprotonated thymine radical (N1[T-H]^.) is measured accruately to be 26 322 ± 5 wn (3.2635 ± 0.0006 eV). By tuning the detachment laser to the sixteen vibrational levels of the dipole-bound state that are above the detachment threshold, highly non-Franck-Condon resonant-enhanced photoelectron spectra are obtained due to state- and mode-selective vibrational autodetachment. Much richer vibrational information is obtained for the deprotonated thymine radical from the photodetachment and resonant-enhanced photoelectron spectroscopy. Eleven fundamental vibrational frequencies in the low-frequency regime are obtained for the N1[T-H]^. radical, including the two lowest-frequency internal rotational modes of the methyl group at 70 ± 8 wn and 92 ± 5 wn. D. L. Huang, H. T. Liu, C. G. Ning, G. Z. Zhu and L. S. Wang, Chem. Sci., 6, 3129-3138 (2015)

  9. Vibrational Spectroscopy of Biomembranes (United States)

    Schultz, Zachary D.; Levin, Ira W.


    Vibrational spectroscopy, commonly associated with IR absorption and Raman scattering, has provided a powerful approach for investigating interactions between biomolecules that make up cellular membranes. Because the IR and Raman signals arise from the intrinsic properties of these molecules, vibrational spectroscopy probes the delicate interactions that regulate biomembranes with minimal perturbation. Numerous innovative measurements, including nonlinear optical processes and confined bilayer assemblies, have provided new insights into membrane behavior. In this review, we highlight the use of vibrational spectroscopy to study lipid-lipid interactions. We also examine recent work in which vibrational measurements have been used to investigate the incorporation of peptides and proteins into lipid bilayers, and we discuss the interactions of small molecules and drugs with membrane structures. Emerging techniques and measurements on intact cellular membranes provide a prospective on the future of vibrational spectroscopic studies of biomembranes.

  10. Experimental and modeling study of thermal rate coefficients and cross sections for electron attachment to C(60). (United States)

    Viggiano, Albert A; Friedman, Jeffrey F; Shuman, Nicholas S; Miller, Thomas M; Schaffer, Linda C; Troe, Jürgen


    Thermal electron attachment to C(60) has been studied by relative rate measurements in a flowing afterglow Langmuir probe apparatus. The rate coefficients of the attachment k(1) are shown to be close to 10(-6) cm(3) s(-1) with a small negative temperature coefficient. These results supersede measurements from the 1990s which led to much smaller values of k(1) with a large positive temperature coefficient suggesting an activation barrier. Theoretical modeling of k(1) in terms of generalized Vogt-Wannier capture theory shows that k(1) now looks more consistent with measurements of absolute attachment cross sections sigma(at) than before. The comparison of capture theory and experimental rate or cross section data leads to empirical correction factors, accounting for "intramolecular vibrational relaxation" or "electron-phonon coupling," which reduce k(1) below the capture results and which, on a partial wave-selected level, decrease with increasing electron energy.

  11. Clinical evaluation of mandibular implant overdentures via Locator implant attachment and Locator bar attachment (United States)

    Seo, Yong-Ho; Bae, Eun-Bin; Kim, Jung-Woo; Lee, So-Hyoun; Jeong, Chang-Mo; Jeon, Young-Chan


    PURPOSE The aim of this study was to evaluate the clinical findings and patient satisfaction on implant overdenture designed with Locator implant attachment or Locator bar attachment in mandibular edentulous patients. MATERIALS AND METHODS Implant survival rate, marginal bone loss, probing depth, peri-implant inflammation, bleeding, plaque, calculus, complications, and satisfaction were evaluated on sixteen patients who were treated with mandibular overdenture and have used it for at least 1 year (Locator implant attachment: n=8, Locator bar attachment: n=8). RESULTS Marginal bone loss, probing depth, plaque index of the Locator bar attachment group were significantly lower than the Locator implant attachment group (P.05). The replacement of the attachment components was the most common complication in both groups. Although there was no correlation between marginal bone loss and plaque index, a significant correlation was found between marginal bone loss and probing depth. CONCLUSION The Locator bar attachment group indicates lesser marginal bone loss and need for maintenance, as compared with the Locator implant attachment group. This may be due to the splinting effect among implants rather than the types of Locator attachment. PMID:27555901

  12. Investigation for parametric vibration of rolling mill

    Institute of Scientific and Technical Information of China (English)

    唐华平; 丁睿; 吴运新; 钟掘


    The vibration unsteady condition of rolling mill caused by flexural vibration of strip has been investigated. The parametric flexural vibration equation of rolled strip has been established. The parametric flexural vibration stability of rolled strip has been studied and the regions of stability and unstability have been determined based on Floquet theory and perturbation method. The flexural-vibration of strip is unstable when the frequency of variable tension is two times as the natural frequency of flexural-vibration strip. The characteristic of current in a temp driving motor's main loop has been studied and tested, it has been proved that there are 6 harmonic component and 12 harmonic component in main loop of driving motor electricity. The vertical vibration of working roller has been tested, the test result approves that the running unsteady is caused by parametric vibration. It attaches importance to the parametric vibration of rolling mill.

  13. Probing chiral solute-water hydrogen bonding networks by chirality transfer effects: A vibrational circular dichroism study of glycidol in water (United States)

    Yang, Guochun; Xu, Yunjie


    Vibrational absorption (VA) and vibrational circular dichroism (VCD) spectra of (S)-(-)-glycidol were measured in water with a concentration of 6.0M in the 1000-1750 cm-1 region. Prominent and complex VCD spectral features were detected at the water bending vibrational region. Our experimental results show that water molecules can become optically active through hydrogen bonding interactions with glycidol molecules. To model the glycidol-water hydrogen bonding network in the solution, molecular dynamics simulations using the AMBER9 suite of programs were carried out. Altogether, 34 conformers of the small glycidol-(water)N clusters with N =1, 2, 3, and 4 were considered. Geometry optimizations, harmonic frequency calculations, and the VA and VCD intensity predictions of these small glycidol-water clusters were performed at the B3LYP/6-311++G(d,p) level of theory using the GAUSSIAN 03 program package. Strong cooperative hydrogen bonding effects were detected in the larger glycidol-(water)N clusters. The population weighted VA and VCD spectra of each N group of glycidol (water)N=1,2,3,4 were used to produce the simulated VA and VCD spectra, which are in good agreement with the experimental VA and VCD spectra. The study shows that all these clusters make important contributions to the observed spectra and are the most important species in the aqueous solution with complicated equilibriums among them.

  14. Priming the Secure Attachment Schema: Effects on Emotion Information Processing

    Directory of Open Access Journals (Sweden)

    Panoraia Andriopoulos


    Full Text Available The present study examined the effects of secure schema activation on selective attention towards attachment-related and emotional information. Seventy two participants were randomly allocated into two conditions–subliminal priming of mental representations of supportive attachment figures (a Picasso sketch of a mother holding a baby and looking into his eyes and a no priming condition followed by an administration of a dot probe task that included positive and negative attachment-related and emotion words. The results showed that the activation of the secure prime in conjunction with chronic attachment orientations affected the processing of positive and negative attachment-unrelated emotional information. Results highlight relationships between higher-order processes of the attachment system (attachment schema activation with early stage information processing (selective attention as assessed by the dot probe task. Methodological issues are discussed with reference to the priming method used and the traditional version of the dot-probe task.

  15. Structural dynamics inside a functionalized metal–organic framework probed by ultrafast 2D IR spectroscopy (United States)

    Nishida, Jun; Tamimi, Amr; Fei, Honghan; Pullen, Sonja; Ott, Sascha; Cohen, Seth M.; Fayer, Michael D.


    The structural elasticity of metal–organic frameworks (MOFs) is a key property for their functionality. Here, we show that 2D IR spectroscopy with pulse-shaping techniques can probe the ultrafast structural fluctuations of MOFs. 2D IR data, obtained from a vibrational probe attached to the linkers of UiO-66 MOF in low concentration, revealed that the structural fluctuations have time constants of 7 and 670 ps with no solvent. Filling the MOF pores with dimethylformamide (DMF) slows the structural fluctuations by reducing the ability of the MOF to undergo deformations, and the dynamics of the DMF molecules are also greatly restricted. Methodology advances were required to remove the severe light scattering caused by the macroscopic-sized MOF particles, eliminate interfering oscillatory components from the 2D IR data, and address Förster vibrational excitation transfer. PMID:25512539

  16. Direct observation of the cyclic dimer in liquid acetic acid by probing the C=O vibration with ultrafast coherent Raman spectroscopy. (United States)

    Lütgens, Matthias; Friedriszik, Frank; Lochbrunner, Stefan


    We present a comparison of spontaneous Raman and ultrafast coherent anti-Stokes Raman scattering (CARS) spectra of the C=O vibration of liquid acetic acid. The former technique cannot clearly reveal the number of contributions in the spectrum. However, the additional time and spectrally resolved CARS experiment supports strictly the existence of four modes, which proves the coexistence of more than one H-bonded configuration in liquid acetic acid. A comparably slowly dephasing mode which is obscured by a broad band in the linear Raman spectrum is assigned to the cyclic dimer and can be observed freed from all other contributions by ultrafast CARS.

  17. Paternal Attachment, Parenting Beliefs and Children's Attachment (United States)

    Howard, Kimberly S.


    Relationships between fathers' romantic attachment style, parenting beliefs and father-child attachment security and dependence were examined in a diverse sample of 72 fathers of young children. Paternal romantic attachment style was coded based on fathers' endorsement of a particular style represented in the Hazan and Shaver Three-Category…

  18. Evidence for Landau's critical velocity in superfluid helium nanodroplets from wave packet dynamics of attached potassium dimers

    CERN Document Server

    Schlesinger, Martin; Stienkemeier, Frank; Strunz, Walter T


    Femtosecond pump-probe spectroscopy has been used to study vibrational dynamics of potassium dimers attached to superfluid helium nanodroplets. Comparing the measured data with theoretical results based on dissipative quantum dynamics we propose that the most important effect of the helium environment is a general damping of the vibrational dynamics as a result of the interaction between dimer and collective degrees of freedom of the helium droplet. The calculations allow us to explain crucial experimental findings that are unobserved in gas-phase measurements. Remarkably, best agreement with experiment is found for a model where we neglect damping once a wave packet moves below a critical velocity. In this way the results provide first direct evidence for the Landau critical velocity in superfluid nanodroplets.

  19. Attachment behavior in rats

    NARCIS (Netherlands)

    Sigling, H.O.


    This thesis describes studies into the rat as an animal model for attachment, along the lines of Bowlby's attachment theory. First, the relation between attachment and human psychopathology is reviewed. The conclusion is that psychopathology is more frequent in insecure attached persons and that the

  20. Vibrational spectroscopy at electrified interfaces

    CERN Document Server

    Wieckowski, Andrzej; Braunschweig, Björn


    Reviews the latest theory, techniques, and applications Surface vibrational spectroscopy techniques probe the structure and composition of interfaces at the molecular level. Their versatility, coupled with their non-destructive nature, enables in-situ measurements of operating devices and the monitoring of interface-controlled processes under reactive conditions. Vibrational Spectroscopy at Electrified Interfaces explores new and emerging applications of Raman, infrared, and non-linear optical spectroscopy for the study of charged interfaces. The book draws from hu

  1. Depression and attachment problems.


    Pettem, O; M. West; Mahoney, A; Keller, A.


    This study investigated the characteristics related to attachment of 42 depressed psychiatric patients and 42 non-depressed psychiatric controls. The depressed subjects demonstrated an anxious pattern of attachment, characterized by either intense care-seeking in relation to their attachment figure or angry withdrawal from their attachment figure when their desire for security was frustrated. The results are discussed in terms of Bowlby's attachment construct.

  2. Adult attachment styles

    Directory of Open Access Journals (Sweden)

    Maša Žvelc


    Full Text Available Theory of attachment primarily described early relationships between a child and his caretakers. In the last twenty years there is a growing interest in adult attachment research. Theories and research findings of adult attachment stem from two different methodological approaches. The first approach measures adult attachment through Adult Attachment Interview (AAI; Main, 1991 where the attachment is assessed through the narratives of adult people of their early child experiences with their primary caretakers. The second approach measures adult attachment with the help of self-evaluative questionnaires, developed by (a Hazan and Shaver (1987 who started this approach in the field of personality and social psychology, and (b Bartholomew and Horowitz (1991. Research shows that there is significant correlation between early and adult attachment style. Attachment styles are passed from generation to generation. Basic adult attachment styles are: securely attached, preoccupied, fearful-avoidant, dismissing-avoidant and disorganized. Previous research using Barholomew and Horowitz (1991 Relationship Questionnaire on 176 Slovenian students showed that 48% students are securely attached, 29% are fearful-avoidant, 10% are dismissing-avoidant, and 13% have preoccupied attachment style. Theory of attachment is very useful for understanding the behavior and subjective experiences of children and adults. It is applicable to different contexts (psychotherapy, counseling, education .... The paper proposes further research focused on integration of adult attachment styles and types of object relations measured by Test of object relations (Žvelc, 1998 and Pictorial test of Separation and Individuation (Žvelc, 2003.

  3. Femtosecond nonlinear spectroscopy at surfaces: Second-harmonic probing of hole burning at the Si(111)7x7 surface and fourier-transform sum-frequency vibrational spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    McGuire, John Andrew [Univ. of California, Berkeley, CA (United States)


    The high temporal resolution and broad bandwidth of a femtosecond laser system are exploited in a pair of nonlinear optical studies of surfaces. The dephasing dynamics of resonances associated with the adatom dangling bonds of the Si(111)7 x 7 surface are explored by transient second-harmonic hole burning, a process that can be described as a fourth-order nonlinear optical process. Spectral holes produced by a 100 fs pump pulse at about 800 nm are probed by the second harmonic signal of a 100 fs pulse tunable around 800 nm. The measured spectral holes yield homogeneous dephasing times of a few tens of femtoseconds. Fits with a Lorentzian spectral hole centered at zero probe detuning show a linear dependence of the hole width on pump fluence, which suggests that charge carrier-carrier scattering dominates the dephasing dynamics at the measured excitation densities. Extrapolation of the deduced homogeneous dephasing times to zero excitation density yields an intrinsic dephasing time of {approx} 70 fs. The presence of a secondary spectral hole indicates that scattering of the surface electrons with surface optical phonons at 570 cm-1 occurs within the first 200 fs after excitation. The broad bandwidth of femtosecond IR pulses is used to perform IR-visible sum frequency vibrational spectroscopy. By implementing a Fourier-transform technique, we demonstrate the ability to obtain sub-laser-bandwidth spectral resolution. FT-SFG yields a greater signal when implemented with a stretched visible pulse than with a femtosecond visible pulse. However, when compared with multichannel spectroscopy using a femtosecond IR pulse but a narrowband visible pulse, Fourier-transform SFG is found to have an inferior signal-to-noise ratio. A mathematical analysis of the signal-to-noise ratio illustrates the constraints on the Fourier-transform approach.

  4. Reactive Attachment Disorder (United States)

    ... Reactive Attachment Disorder and Disinhibited Social Engagement Disorder. Reactive Attachment Disorder (RAD) Children with RAD are less likely to interact with other people because of negative experiences with adults in their early years. They have difficulty calming ...

  5. Belt attachment and system (United States)

    Schneider, Abraham D.; Davidson, Erick M.


    Disclosed herein is a belt assembly including a flexible belt with an improved belt attachment. The belt attachment includes two crossbars spaced along the length of the belt. The crossbars retain bearings that allow predetermined movement in six degrees of freedom. The crossbars are connected by a rigid body that attaches to the bearings. Implements that are attached to the rigid body are simply supported but restrained in pitching rotation.

  6. Attachment Without Fear



    John Bowlby hypothesized an attachment system that interacts with caregiving, exploration, and fear systems in the brain, with a particular emphasis on fear. Neurobiological research confirms many of his hypotheses and also raises some new questions. A psychological model based on this neurobiological research is presented here. The model extends conventional attachment theory by describing additional attachment processes independent of fear. In this model, the attachment elements of trust, o...

  7. Attachment Without Fear. (United States)

    Bell, David C


    John Bowlby hypothesized an attachment system that interacts with caregiving, exploration, and fear systems in the brain, with a particular emphasis on fear. Neurobiological research confirms many of his hypotheses and also raises some new questions. A psychological model based on this neurobiological research is presented here. The model extends conventional attachment theory by describing additional attachment processes independent of fear. In this model, the attachment elements of trust, openness, and dependence interact with the caregiving elements of caring, empathy, and responsibility.

  8. Attachment over Time. (United States)

    Lewis, Michael; Feiring, Candice; Rosenthal, Saul


    Examined continuity in attachment classification from infancy through adolescence and related it to autobiographical memories of childhood, divorce, and maladjustment in white middle-class children. Found no continuity in attachment classification from 1 to 18 years and no relation between infant attachment status and adolescent adjustment.…

  9. Attachment and Psychopathology

    Directory of Open Access Journals (Sweden)

    Mehmet Fatih Ustundag


    Full Text Available The type of attachment defined in the early stages of life and thought to be continuous, is a phenomenon that shapes the pattern of how a person makes contact with others. The clinical appearance of every type of attachment is different and each one has prospective and retrospective phenomenological reflections. In all stages of life and in close relationships, it can be observed if a person gets in close contact with someone else and if this relation bears supportive and protective qualities. According to attachment theorists, once it is defined as safe or unsafe during nursing period, it shows little change. Starting from Bowlby’s work, unsafe attachment type is considered as the determining factor of psychopathology in the later periods of life, while safe attachment is considered as in relation with healthy processes. The nature’s original model is safe attachment. Anxious/indecisive attachment, an unsafe attachment type, is associated with anxiety disorders and depressive disorder, while avoidant attachment is associated with behavior disorder and other extroverted pathologies. Disorganized/disoriented attachment is considered to be together with dissociative disorder. The aim of this paper is to review attachment theory and the relation between attachment and psychopathology.

  10. Waves & vibrations


    Nicolas, Maxime


    Engineering school; This course is designed for students of Polytech Marseille, engineering school. It covers first the physics of vibration of the harmonic oscillator with damping and forcing, coupled oscillators. After a presentation of the wave equation, the vibration of strings, beams and membranes are studied.

  11. Attachment Security and Pain

    DEFF Research Database (Denmark)

    Andersen, Tonny Elmose; Lahav, Yael; Defrin, Ruth;


    The present study assesses for the first time, the possible disruption effect of posttraumatic stress symptoms (PTSS) with regard to the protective role of attachment on pain, among ex-POWs. While secure attachment seems to serve as a buffer, decreasing the perception of pain, this function may...... be disrupted by PTSS. The study sample included 104 subjects who were combat veterans of the 1973 Yom Kippur War comprising of 60 male ex-prisoners of war (ex-POWs) and 44 comparable male combat veterans. Both attachment and pain were investigated experimentally in the laboratory and via questionnaires. We...... found that ex-POWs showed higher levels of clinical pain and attachment insecurities compared to controls. Moreover, attachment avoidance and soothing effect of attachment (SEA) were both associated with lower levels of clinical pain. Most importantly, PTSS moderated the associations between attachment...

  12. Mobile Probing and Probes

    DEFF Research Database (Denmark)


    Mobile probing is a method, developed for learning about digital work situations, as an approach to discover new grounds. The method can be used when there is a need to know more about users and their work with certain tasks, but where users at the same time are distributed (in time and space......). Mobile probing was inspired by the cultural probe method, and was influenced by qualitative interview and inquiry approaches. The method has been used in two subsequent projects, involving school children (young adults at 15-17 years old) and employees (adults) in a consultancy company. Findings point...... to mobile probing being a flexible method for uncovering the unknowns, as a way of getting rich data to the analysis and design phases. On the other hand it is difficult to engage users to give in depth explanations, which seem easier in synchronous dialogs (whether online or face2face). The development...

  13. Mobile Probing and Probes

    DEFF Research Database (Denmark)


    Mobile probing is a method, which has been developed for learning about digital work situations, as an approach to discover new grounds. The method can be used when there is a need to know more about users and their work with certain tasks, but where users at the same time are distributed (in time...... and space). Mobile probing was inspired by the cultural probe method, and was influenced by qualitative interview and inquiry approaches. The method has been used in two subsequent projects, involving school children (young adults at 15-17 years old) and employees (adults) in a consultancy company. Findings...... point to mobile probing being a flexible method for uncovering the unknowns, as a way of getting rich data to the analysis and design phases. On the other hand it is difficult to engage users to give in depth explanations, which seem easier in synchronous dialogs (whether online or face2face...

  14. Single-nanoparticle-terminated tips for scanning probe microscopy. (United States)

    Vakarelski, Ivan U; Higashitani, Ko


    We have developed a wet-chemistry procedure to attach a 10-40 nm colloidal gold nanoparticle to the top of a scanning probe microscopy (SPM) probe tip, making experiments of single nanoparticle interaction possible. This procedure of particle attachment is flexible and can be modified to attach nanoparticles of different kinds and sizes. The single-nanoparticle-terminated tips also have potential in various other applications, such as probes of enhanced sensitivity for optical and magnetic modes SPM.

  15. Blade attachment assembly (United States)

    Garcia-Crespo, Andres Jose; Delvaux, John McConnell; Miller, Diane Patricia


    An assembly and method for affixing a turbomachine rotor blade to a rotor wheel are disclosed. In an embodiment, an adaptor member is provided disposed between the blade and the rotor wheel, the adaptor member including an adaptor attachment slot that is complementary to the blade attachment member, and an adaptor attachment member that is complementary to the rotor wheel attachment slot. A coverplate is provided, having a coverplate attachment member that is complementary to the rotor wheel attachment slot, and a hook for engaging the adaptor member. When assembled, the coverplate member matingly engages with the adaptor member, and retains the blade in the adaptor member, and the assembly in the rotor wheel.

  16. Good Vibrations


    Panesar, Lucy


    Good Vibrations was a market research exercise conducted by Felicity (my alter-ego) and assistants to help develop marketing and packaging for an electro-therapeutic device (vibrator) used to treat hysteria and other female stress related disorders. It was a live art work commissioned by The Live Art Development Agency for East End Collaborations on 6th May 2007 and the South London Gallery for Bonkersfest on 2nd June 2007.

  17. Vibration sensors (United States)

    Gupta, Amita; Singh, Ranvir; Ahmad, Amir; Kumar, Mahesh


    Today, vibration sensors with low and medium sensitivities are in great demand. Their applications include robotics, navigation, machine vibration monitoring, isolation of precision equipment & activation of safety systems e.g. airbags in automobiles. Vibration sensors have been developed at SSPL, using silicon micromachining to sense vibrations in a system in the 30 - 200 Hz frequency band. The sensing element in the silicon vibration sensor is a seismic mass suspended by thin silicon hinges mounted on a metallized glass plate forming a parallel plate capacitor. The movement of the seismic mass along the vertical axis is monitored to sense vibrations. This is obtained by measuring the change in capacitance. The movable plate of the parallel plate capacitor is formed by a block connected to a surrounding frame by four cantilever beams located on sides or corners of the seismic mass. This element is fabricated by silicon micromachining. Several sensors in the chip sizes 1.6 cm x 1.6 cm, 1 cm x 1 cm and 0.7 cm x 0.7 cm have been fabricated. Work done on these sensors, techniques used in processing and silicon to glass bonding are presented in the paper. Performance evaluation of these sensors is also discussed.

  18. Determining the vibrations between sensor and sample in SQUID microscopy (United States)

    Schiessl, Daniel; Kirtley, John R.; Paulius, Lisa; Rosenberg, Aaron J.; Palmstrom, Johanna C.; Ullah, Rahim R.; Holland, Connor M.; Fung, Y.-K.-K.; Ketchen, Mark B.; Gibson, Gerald W.; Moler, Kathryn A.


    Vibrations can cause noise in scanning probe microscopies. Relative vibrations between the scanning sensor and the sample are important but can be more difficult to determine than absolute vibrations or vibrations relative to the laboratory. We measure the noise spectral density in a scanning SQUID microscope as a function of position near a localized source of magnetic field and show that we can determine the spectra of all three components of the relative sensor-sample vibrations. This method is a powerful tool for diagnosing vibrational noise in scanning microscopies.

  19. Attachment and psychosis

    NARCIS (Netherlands)

    Korver, N.


    The main goal of this thesis was to further our understanding of current psychosocial models by introducing attachment as a relevant developmental framework. Firstly, attachment theory provides a psychosocial model for a developmental pathway to psychosis. Secondly, after expression of psychotic sym

  20. Attachment Theory and Mindfulness (United States)

    Snyder, Rose; Shapiro, Shauna; Treleaven, David


    We initiate a dialog between two central areas in the field of psychology today: attachment theory/research and mindfulness studies. The impact of the early mother-infant relationship on child development has been well established in the literature, with attachment theorists having focused on the correlation between a mother's capacity for…

  1. Temperament and Attachment Disorders (United States)

    Zeanah, Charles H.; Fox, Nathan A.


    Reviewed in this article is research on children with reactive attachment disorder (RAD) who exhibit specific patterns of socially aberrant behavior resulting from being maltreated or having limited opportunities to form selective attachments. There are no data explaining why 2 different patterns of the disorder, an emotionally withdrawn-inhibited…

  2. Reactive Attachment Disorder. (United States)

    Chapman, Sue


    Written by a British parent, this case study tells the story of an adopted child who experienced many difficulties adjusting to life at home and school. It describes attachment disorder, possible causes of attachment difficulties, the bonding cycle, therapeutic parenting, and how schools can support the re-nurturing process. (Contains references.)…

  3. Adolescent attachment and psychopathology. (United States)

    Rosenstein, D S; Horowitz, H A


    The relationships among attachment classification, psychopathology, and personality traits were examined in a group of 60 psychiatrically hospitalized adolescents. The concordance of attachment classification was examined in 27 adolescent-mother pairs. Both adolescent and maternal attachment status were overwhelmingly insecure and were highly concordant. Adolescents showing a dismissing attachment organization were more likely to have a conduct or substance abuse disorder, narcissistic or antisocial personality disorder, and self-reported narcissistic, antisocial, and paranoid personality traits. Adolescents showing a preoccupied attachment organization were more likely to have an affective disorder, obsessive-compulsive, histrionic, borderline or schizotypal personality disorder, and self-reported avoidant, anxious, and dysthymic personality traits. The results support a model of development of psychopathology based partially on relational experiences with parents.

  4. Late-life attachment. (United States)

    Freitas, Mélanie; Rahioui, Hassan


    Old age is likely to cause a crisis in one's life because of the vulnerabilities it brings up, acting as stressful elements disrupting the elder's feeling of security. It leads to the activation of what is called his attachment system, consisting in attachment styles and interpersonal emotional regulation strategies. To recover a higher sense of safety, the elder would refer to his attachment figures, that is to say closed people paying attention to him, showing towards him availability and consideration. However older adults particularly see their tolerance threshold lowered, regarding an accumulation of losses (true or symbolic) and stressful events within their lifetime. In a psychological and organic exhaustion phenomenon, the risk is to wear out the interpersonal emotional regulation strategies. These are as much vulnerabilities that may increase psychiatric decompensation, including depression. To resolve the tension of this period and to found a necessary secure feeling, the elder will have to redesign the attachment links previously settled and proceed to adjustments to this new context. The need of relational closeness comes back in the elders' attachment behaviour, counting on attachment figures not only to help their loneliness or dependency, but essentially to support them in a narcissist and affective way. That is why attachment theory enlightens the late life period, such as the new challenges older adults have to face. Many studies recognize its value in understanding the transition to old age, but without proposing conceptualization. We aim first to focus on attachment conception to say how much it is relevant with elderly, and then to describe specific terms of attachment within this population in order to better understand those patients. To finish, we must think about new therapeutic proposals taking into consideration the attachment perspective for a better understanding of old age transition.

  5. Urban vibrations

    DEFF Research Database (Denmark)

    Morrison, Ann; Knudsen, L.; Andersen, Hans Jørgen


    In   this   paper   we   describe   a   field   study   conducted   with   a   wearable   vibration   belt   where   we   test   to   determine   the   vibration   intensity   sensitivity   ranges   on   a   large   diverse   group   of   participants   with   evenly   distributed  ages  and......   lab   studies   in   that   we   found   a   decreased   detection   rate   in   busy   environments.   Here   we   test   with   a   much   larger   sample   and   age   range,   and   contribute   with   the   first   vibration  sensitivity  testing  outside  the  lab  in  an  urban   public...

  6. Vibration transmission characteristics of the legs of freely standing honeybees

    DEFF Research Database (Denmark)

    Rohrseitz, Kristin; Kilpinen, Ole


    The leg vibrations of honeybees standing on a vibrating substrate were measured with laser Doppler vibrometry, both in freely standing bees and in bees attached to a holder. In both cases, no resonances were found. In the fixed bee preparation, the legs moved with approximately the same amplitude...

  7. Matching Vibration Testing to "Real-World" Conditions (United States)

    Olsen, Albert D., Jr.; Keblaitis, A. V.


    Vibration spectrum of test machine adjusted to that observed in operation. Test specimen placed in test fixture and attached to shaker. Shaker initially operated at one-quarter full level of input spectrum to prevent overloading. Short vibration test run, and specimen response compared to control spectrum. Imput spectrum then adjusted until response resembles control spectrum.

  8. Attachment-related psychodynamics. (United States)

    Shaver, Phillip R; Mikulincer, Mario


    Because there has been relatively little communication and cross-fertilization between the two major lines of research on adult attachment, one based on coded narrative assessments of defensive processes, the other on simple self-reports of 'attachment style' in close relationships, we here explain and review recent work based on a combination of self-report and other kinds of method, including behavioral observations and unconscious priming techniques. The review indicates that considerable progress has been made in testing central hypotheses derived from attachment theory and in exploring unconscious, psychodynamic processes related to affect-regulation and attachment-system activation. The combination of self-report assessment of attachment style and experimental manipulation of other theoretically pertinent variables allows researchers to test causal hypotheses. We present a model of normative and individual-difference processes related to attachment and identify areas in which further research is needed and likely to be successful. One long-range goal is to create a more complete theory of personality built on attachment theory and other object relations theories.

  9. Mechanism of bubble detachment from vibrating walls

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dongjun; Park, Jun Kwon, E-mail:; Kang, Kwan Hyoung [Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Pohang 790-784 (Korea, Republic of); Kang, In Seok [Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-dong, Pohang 790-784 (Korea, Republic of)


    We discovered a previously unobserved mechanism by which air bubbles detach from vibrating walls in glasses containing water. Chaotic oscillation and subsequent water jets appeared when a wall vibrated at greater than a critical level. Wave forms were developed at water-air interface of the bubble by the wall vibration, and water jets were formed when sufficiently grown wave-curvatures were collapsing. Droplets were pinched off from the tip of jets and fell to the surface of the glass. When the solid-air interface at the bubble-wall attachment point was completely covered with water, the bubble detached from the wall. The water jets were mainly generated by subharmonic waves and were generated most vigorously when the wall vibrated at the volume resonant frequency of the bubble. Bubbles of specific size can be removed by adjusting the frequency of the wall's vibration.

  10. The neurobiology of attachment. (United States)

    Insel, T R; Young, L J


    It is difficult to think of any behavioural process that is more intrinsically important to us than attachment. Feeding, sleeping and locomotion are all necessary for survival, but humans are, as Baruch Spinoza famously noted, "a social animal" and it is our social attachments that we live for. Over the past decade, studies in a range of vertebrates, including humans, have begun to address the neural basis of attachment at a molecular, cellular and systems level. This review describes some of the important insights from this work.

  11. Vibration and acoustic environments for payload/cargo integration (United States)

    Hill, R. E.; Coody, M. C.


    Shuttle orbiter launch vibration and acoustic environments for cargo bay/payload interfaces are predicted. Data acquired during Shuttle flight tests are compared with the preflight estimates. Vibration response data for payload attachment locations are presented, along with acoustic data in the form of noise-level spectra measured at various locations in the cargo bay and space averages of the noise levels. It is shown that the payload-bay vibration and acoustic environments are generally less severe than predicted.

  12. Vibrating minds

    CERN Multimedia


    Ed Witten is one of the leading scientists in the field of string theory, the theory that describes elementary particles as vibrating strings. This week he leaves CERN after having spent a few months here on sabbatical. His wish is that the LHC will unveil supersymmetry.

  13. Theoretical modelling of a beam with attached spring-mass-damper system

    Directory of Open Access Journals (Sweden)

    Azmirul Mohd Rozlan Syaiful


    Full Text Available Vibrations are always undesirable, wasting energy besides producing noise. In this case, beams which are prominent component in most engineering having no exemption from the vibration effect when imposed by dynamic loading. One of the approach to attenuate vibration of a structure is by having a spring-mass-damper (SMD system or typically known as vibration neutralizer attached to the vibrating structure. This method is more promising as it does not contribute significant additional energy to the structure. The work presented in this paper describes the frequency response (FRF of a simply supported beam with an attached SMD system. A mathematical model of a beam was at first developed in the study which was further derived to include the attachment of SMD system. In order to transform the derived equations into a form of graph that can be analysed, Matlab® software was used. The outcome from Matlab® shows that the attachment of SMD onto beam attenuates its vibration significantly. The result also displays a good resemblance FRF when compared with numerical finite element analysis of Ansys®. It is expected that the theoretical derivation demonstrated in this paper provide a helpful reference to future researchers who endeavour to find equations of a simply supported beam with an attached SMD system as well as for a vibration control study.

  14. Aggression And Attachment Security

    Directory of Open Access Journals (Sweden)

    Prem Verma


    Full Text Available Objective:The aim of the present study is to examine the factors related aggression in Iranian and Indian school children. Method: Attachment security (dependency, availability, and total considered as the variable. The KSS questionnaire was administrated students in the 5th grade; 300 were Iranian and 300 were Indian consisted of 150 boys and 150 girls. Results: Attachment security demonstrated significant negative correlations with aggression in the boys, girls and the total Iranian sample. The dependency on mothers was the only case with insignificant correlation.In the Indian sample, attachment security was also found to be significantly negatively correlated with aggression. The only exception was the correlation between mother's availability and aggression in girls, which was not significant Conclusion: It is important that parents treat their children in a tender, manner so that a secure attachment develop between them.

  15. Attachment to land

    Directory of Open Access Journals (Sweden)

    Paul Rozin


    Full Text Available This is a first study on attachment to national and sacred land and land as a protected value. A measure of attachment to the land of Israel is developed and administered to two groups, Jewish college students in Israel and the United States. Levels of land attachment are high and not significantly different in the two groups, with a great deal of variation. Land may become more important through being inhabited by a group over centuries. This is a positive contagion effect, and is opposed in some cases by negative contagion produced when the ``enemies'' live on the land for some period of time. We demonstrate a significant correlation of positive contagion sensitivity with attachment to the land of Israel. Unlike many other cases of the interaction of positive and negative contagion, negative contagion does not overwhelm positive contagion in the domain of land attachment. We also present evidence for linkages between political positions, religiosity, importance of Israel, Arab aversion, and vulnerability of Israel with attachment to land, but these do not fully account for the contagion effects. A number of significant differences between Israelis and Americans are described.

  16. Propellant grain dynamics in aft attach ring of shuttle solid rocket booster (United States)

    Verderaime, V.


    An analytical technique for implementing simultaneously the temperature, dynamic strain, real modulus, and frequency properties of solid propellant in an unsymmetrical vibrating ring mode is presented. All dynamic parameters and sources are defined for a free vibrating ring-grain structure with initial displacement and related to a forced vibrating system to determine the change in real modulus. Propellant test data application is discussed. The technique was developed to determine the aft attach ring stiffness of the shuttle booster at lift-off.

  17. Multidimensional Time-Resolved Spectroscopy of Vibrational Coherence in Biopolyenes (United States)

    Buckup, Tiago; Motzkus, Marcus


    Multidimensional femtosecond time-resolved vibrational coherence spectroscopy allows one to investigate the evolution of vibrational coherence in electronic excited states. Methods such as pump-degenerate four-wave mixing and pump-impulsive vibrational spectroscopy combine an initial ultrashort laser pulse with a nonlinear probing sequence to reinduce vibrational coherence exclusively in the excited states. By carefully exploiting specific electronic resonances, one can detect vibrational coherence from 0 cm-1 to over 2,000 cm-1 and map its evolution. This review focuses on the observation and mapping of high-frequency vibrational coherence for all-trans biological polyenes such as β-carotene, lycopene, retinal, and retinal Schiff base. We discuss the role of molecular symmetry in vibrational coherence activity in the S1 electronic state and the interplay of coupling between electronic states and vibrational coherence.

  18. Multidimensional time-resolved spectroscopy of vibrational coherence in biopolyenes. (United States)

    Buckup, Tiago; Motzkus, Marcus


    Multidimensional femtosecond time-resolved vibrational coherence spectroscopy allows one to investigate the evolution of vibrational coherence in electronic excited states. Methods such as pump-degenerate four-wave mixing and pump-impulsive vibrational spectroscopy combine an initial ultrashort laser pulse with a nonlinear probing sequence to reinduce vibrational coherence exclusively in the excited states. By carefully exploiting specific electronic resonances, one can detect vibrational coherence from 0 cm(-1) to over 2,000 cm(-1) and map its evolution. This review focuses on the observation and mapping of high-frequency vibrational coherence for all-trans biological polyenes such as β-carotene, lycopene, retinal, and retinal Schiff base. We discuss the role of molecular symmetry in vibrational coherence activity in the S1 electronic state and the interplay of coupling between electronic states and vibrational coherence.

  19. Attachment and coercive sexual behavior. (United States)

    Smallbone, S W; Dadds, M R


    This study examined the relationships between childhood attachment and coercive sexual behavior. One hundred sixty-two male undergraduate students completed self-report measures of childhood maternal attachment, childhood paternal attachment, adult attachment, antisociality, aggression, and coercive sexual behavior. As predicted, insecure childhood attachment, especially insecure paternal attachment, was associated with antisociality, aggression, and coercive sexual behavior. Moreover, childhood attachment independently predicted coercive sexual behavior after antisociality and aggression were statistically controlled. The hypothesis that paternal avoidant attachment would predict coercive sexual behavior independently of its relationship with aggression and antisociality was also supported. Posthoc analysis indicated that maternal anxious attachment was associated with antisociality and that paternal avoidant attachment was associated with both antisociality and coercive sexual behavior. These results are consistent with criminological and psychological research linking adverse early family experiences with offending and lend support to an attachment-theoretical framework for understanding offending behavior in general and sexual offending behavior in particular.

  20. Pain, Affect, and Attachment

    Directory of Open Access Journals (Sweden)

    Carl Eduard Scheidt


    Full Text Available Various psychodynamic processes may underlie the development of psychogenic pain disorder such as conversion, the displacement of affect, or narcissistic defenses. However, many of the processes suggested are related to a disorder of affect regulation. The term affect regulation in psychoanalytic literature refers to phenomena which are often described by the concept of alexithymia. Empirical observations suggest that alexithymia is correlated to insecure attachment, especially an insecure dismissing representation of attachment. Psychodynamic psychotherapy in psychogenic pain disorder should focus on the reintegration of split-off affects which may provoke intensive counter-transference and which in order to be used therapeutically must be linked to attachment experiences within and outside of the therapeutic relationship.

  1. Love attitudes and attachment

    Directory of Open Access Journals (Sweden)

    María Elena Brenlla


    Full Text Available Love styles described by Lee are Eros (passionate love, Ludus (game-pla- ying love, Storge (friendship love, Mania (possessive, dependent love, Pragma (logical, “shopping list” love and Agape (all-giving, selfless love. Based on those types, Hendrick and Hendrick developed a 42-ítem rating questionnaire with 7 items measuring each love style (Love Attitudes Scale. Beside, inform about frequency in love relationships and attachment style. The purpose of this study was analyze the reliability and factor structure of the Love Attitudes Scale and to investigate the association between love attitudes and the attachment style. The results (N=280 participants indicate adequate internal consistency (alfa = 0,73. The items were intercorrelated and factored. The best solution extracted six factors using varimax rotation and all six factors accounted 41% of the total variance. Secure attachment was related positively to eros. 


    Directory of Open Access Journals (Sweden)

    Venkata Ratnam Tatavolu


    Full Text Available Research on Active Vibration Control System (AVCS is being carried out to reduce structural vibrations caused by unwanted vibrations in many application areas such as in space, aircraft structures, satellites, automobiles and civil structures (bridges, particularly at low frequencies. The unwanted vibration may cause damage to the structure or degradation to the structure’s performance. The AVCS comprises physical plant, a sensor to detect the source vibration, a DSP based electronic controller using an actuator connected to the structure generates a counter force that is appropriately out of phase but equal in amplitude to the source vibration. As a result two equal and opposite forces cancel each other by the principle of super position and structure stops vibrating. The main objective of this research work is to develop an embedded computer based real time AVCS for reducing low frequency tonal vibration response of a vibrating flexible cantilever beam by automatic modification of the vibrating beam’s structural response and to verify the performance of the developed system experimentally. The developed AVCS is a generic design platform that can be applied for designing adaptive feed forward AVC and feedback AVC. This study presents the vibration control methodology adapted for reducing tonal vibration generated by a sine generator connected to the primary source actuator attached to one end of the cantilever beam. The secondary actuator is attached to the beam on the other end through the AVCS to reduce primary vibration by destructive interference with the original response of the system, caused by the primary source of vibration. Adaptive feed forward Active Vibration Control (AVC technique is used with Filtered-X Least Mean Square (FxLMS algorithm using FIR digital filter. A cantilever beam was considered as plant and embedded computer based AVCS was tested and evaluated using an experimental setup. The experimental results are

  3. Attachment Theory in Tourism


    Korstanje, Maximiliano


    The following work is intended to a revision on attachment theory. The postulates of the theory of the sure base point that the system of exploration meets in narrow relation the system of conducts of attachment and the figure of the keepers. The conducts that characterize and symbolize the relation of the adult with the environment are carried back to the early age, in the moment in which the child develops the affective capacity. What difference does exist between someone who decides to jou...

  4. Ladder attachment platform (United States)

    Swygert,; Richard, W [Springfield, SC


    A ladder attachment platform is provided that includes a base for attachment to a ladder that has first and second side rails and a plurality of rungs that extend between in a lateral direction. Also included is a user platform for having a user stand thereon that is carried by the base. The user platform may be positioned with respect to the ladder so that it is not located between a first plane that extends through the first side rail and is perpendicular to the lateral direction and a second plane that extends through the second side rail and is perpendicular to the lateral direction.

  5. Attachment and Women's Faith Development (United States)

    Joung, Eun Sim


    This article explores the relationship between human attachment and God attachment, particularly in Christian women's experiences of faith. It is based on the attachment perspective as a conceptual framework. The main aim was to evolve an attachment-theoretical approach to women's faith development and to offer a complementary path to interpret…

  6. Linear and nonlinear piezoelectric shunting strategies for vibration mitigation

    Directory of Open Access Journals (Sweden)

    Soltani P.


    Full Text Available This paper studies linear and nonlinear piezoelectric vibration absorbers that are designed based on the equal-peak method. A comparison between the performance of linear mechanical and electrical tuned vibration absorbers coupled to a linear oscillator is first performed. Nonlinearity is then introduced in the primary oscillator to which a new nonlinear electrical tuned vibration absorber is attached. Despite the frequency-energy dependence of nonlinear oscillations, we show that the nonlinear absorber is capable of effectively mitigating the vibrations of the nonlinear primary system in a large range of forcing amplitudes.

  7. Adaptive vibration isolation system for diesel engine

    Institute of Scientific and Technical Information of China (English)

    YANG Tie-jun; ZHANG Xin-yu; XIAO You-hong; HUANG Jin-e; LIU Zhi-gang


    An active two-stage isolation mounting, on which servo-hydraulic system is used as the actuator (secondary vibration source) and a diesel engine is used as primary vibration source, has been built. The upper mass of the mounting is composed of a 495diesel and an electrical eddy current dynamometer. The lower mass is divided into four small masses to which servo-hydraulic actuator and rubber isolators are attached. According to the periodical characteristics of diesel vibration signals, a multi-point adaptive strategy based on adaptive comb filtered algorithm is applied to active multi-direction coupled vibrations control for the engine. The experimental results demonstrate that a good suppression in the effective range of phase compensation in secondary path (within 100Hz) at different operation conditions is achieved, and verify that this strategy is effective. The features of the active system, the development activities carried out on the system and experimental results are discussed in the paper.

  8. Day Care and Attachment (United States)

    Portnoy, Fern C.; Simmons, Carolyn H.


    The attachment behavior of 35 white, middle-class 3 1/2- to 4-year-olds who had experienced different rearing histories was observed through a series of standardized episodes involving separations and reunions with the mother and a stranger. (Author/JMB)

  9. Attachment and Personality Disorders (United States)

    Sinha, Preeti; Sharan, Pratap


    Personality disorders (PDs) arise from core psychopathology of interpersonal relationships and understanding of self and others. The distorted representations of self and others, as well as unhealthy relationships that characterize persons with various PDs, indicate the possibility that persons with PDs have insecure attachment. Insecure…

  10. God attachment, mother attachment, and father attachment in early and middle adolescence. (United States)

    Sim, Tick Ngee; Yow, Amanda Shixian


    The present study examined the interplay of attachment to God, attachment to mother, and attachment to father with respect to adjustment (hope, self-esteem, depression) for 130 early and 106 middle adolescents in Singapore. Results showed that the parental attachments were generally linked (in expected directions) to adjustment. God attachment, however, had unique results. At the bivariate level, God attachment was only linked to early adolescents' self-esteem. When considered together with parental attachments (including interactions), God attachment did not emerge as the key moderator in attachment interactions and yielded some unexpected results (e.g., being positively linked to depression). These results are discussed viz-a-viz the secure base and safe haven functions that God and parental attachments may play during adolescence.

  11. Vibrational relaxation of pure liquid water

    NARCIS (Netherlands)

    Lindner, J; Vohringer, P; Pshenichnikov, MS; Cringus, D; Wiersma, DA; Mostovoy, M; Vöhringer, Peter; Pshenichnikov, Maxim S.


    Multicolor infrared ultrafast spectroscopy is applied to investigate the vibrational relaxation dynamics in liquid water at room temperature. In a sequence of experiments, both the stretching and the bending mode are photoexcited and probed. A unified model, capable of the reproduction of as much as

  12. Picturing Urban Green Attachments

    DEFF Research Database (Denmark)

    Blok, Anders; Meilvang, Marie Leth


    in the plural’ in the city. In particular, we stress the role assumed in such engagements by various image-making practices, as means for activists to express, share and render publicly visible a range of embodied urban attachments. Pragmatic sociology, we conclude, may contribute to a novel understanding......In this article, we explore the cultural-political tensions and ambiguities of urban ecology, by way of following how activists move and translate between ‘familiar’ and ‘public’ engagements in the green city. Empirically, we locate our exploration in and around Nordhavnen (The North Harbor...... of urban politics as inclusive learning processes, more hospitable to a wider diversity of familiar attachments to cities and their ecologies....

  13. Theory of vibration protection

    CERN Document Server

    Karnovsky, Igor A


    This text is an advancement of the theory of vibration protection of mechanical systems with lumped and distributed parameters. The book offers various concepts and methods of solving vibration protection problems, discusses the advantages and disadvantages of different methods, and the fields of their effective applications. Fundamental approaches of vibration protection, which are considered in this book, are the passive, parametric and optimal active vibration protection. The passive vibration protection is based on vibration isolation, vibration damping and dynamic absorbers. Parametric vibration protection theory is based on the Shchipanov-Luzin invariance principle. Optimal active vibration protection theory is based on the Pontryagin principle and the Krein moment method. The book also contains special topics such as suppression of vibrations at the source of their occurrence and the harmful influence of vibrations on humans. Numerous examples, which illustrate the theoretical ideas of each chapter, ar...

  14. Probing halo molecules with nonresonant light

    CERN Document Server

    Lemeshko, Mikhail


    We show that halo molecules can be probed by "shaking" in a pulsed nonresonant laser field. The field introduces a centrifugal term which expels the highest vibrational level from the potential that binds it. Our numerical simulations as well as an analytic model applied to the Rb$_2$ and KRb Feshbach molecules indicate that shaking by feasible laser pulses can be used to accurately recover the square of the vibrational wavefunction and, by inversion, also the molecular potential.

  15. Fast and reliable method of conductive carbon nanotube-probe fabrication for scanning probe microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dremov, Vyacheslav, E-mail:; Fedorov, Pavel; Grebenko, Artem [Institute of Solid State Physics, RAS, 142432 Chernogolovka (Russian Federation); Interdisciplinary Center for Basic Research, Moscow Institute of Physics and Technology, 141700 Dolgoprudniy (Russian Federation); Fedoseev, Vitaly [Institute of Solid State Physics, RAS, 142432 Chernogolovka (Russian Federation)


    We demonstrate the procedure of scanning probe microscopy (SPM) conductive probe fabrication with a single multi-walled carbon nanotube (MWNT) on a silicon cantilever pyramid. The nanotube bundle reliably attached to the metal-covered pyramid is formed using dielectrophoresis technique from the MWNT suspension. It is shown that the dimpled aluminum sample can be used both for shortening/modification of the nanotube bundle by applying pulse voltage between the probe and the sample and for controlling the probe shape via atomic force microscopy imaging the sample. Carbon nanotube attached to cantilever covered with noble metal is suitable for SPM imaging in such modulation regimes as capacitance contrast microscopy, Kelvin probe microscopy, and scanning gate microscopy. The majority of such probes are conductive with conductivity not degrading within hours of SPM imaging.

  16. Positron-molecule interactions: resonant attachment, annihilation, and bound states

    CERN Document Server

    Gribakin, G F; Surko, C M; 10.1103/RevModPhys.82.2557


    This article presents an overview of current understanding of the interaction of low-energy positrons with molecules with emphasis on resonances, positron attachment and annihilation. Annihilation rates measured as a function of positron energy reveal the presence of vibrational Feshbach resonances (VFR) for many polyatomic molecules. These resonances lead to strong enhancement of the annihilation rates. They also provide evidence that positrons bind to many molecular species. A quantitative theory of VFR-mediated attachment to small molecules is presented. It is tested successfully for selected molecules (e.g., methyl halides and methanol) where all modes couple to the positron continuum. Combination and overtone resonances are observed and their role is elucidated. In larger molecules, annihilation rates from VFR far exceed those explicable on the basis of single-mode resonances. These enhancements increase rapidly with the number of vibrational degrees of freedom. While the details are as yet unclear, intr...

  17. Probe Storage

    NARCIS (Netherlands)

    Gemelli, Marcellino; Abelmann, Leon; Engelen, Johan B.C.; Khatib, Mohammed G.; Koelmans, Wabe W.; Zaboronski, Olog; Campardo, Giovanni; Tiziani, Federico; Laculo, Massimo


    This chapter gives an overview of probe-based data storage research over the last three decades, encompassing all aspects of a probe recording system. Following the division found in all mechanically addressed storage systems, the different subsystems (media, read/write heads, positioning, data chan

  18. Cultural probes

    DEFF Research Database (Denmark)

    Madsen, Jacob Østergaard


    The aim of this study was thus to explore cultural probes (Gaver, Boucher et al. 2004), as a possible methodical approach, supporting knowledge production on situated and contextual aspects of occupation.......The aim of this study was thus to explore cultural probes (Gaver, Boucher et al. 2004), as a possible methodical approach, supporting knowledge production on situated and contextual aspects of occupation....

  19. Attachment: Theoretical Development and Critique (United States)

    Slater, Ruth


    Zeanah argues that ethological attachment theory, as outlined by John Bowlby, has provided one of the most important frameworks for understanding crucial risk and protective factors in social and emotional development. However, although attachment theory and the notion of attachment disorders have influenced such initiatives, many psychologists,…

  20. Attachment Theory: Retrospect and Prospect. (United States)

    Bretherton, Inge


    Provides overview of attachment theory as parented by John Bowlby in "Attachment and Loss". Uses two major concepts from this work to interpret refinements and elaborations of attachment theory attibuted to Mary Ainsworth. Considers how recent insights into development of socioemotional understanding and development of event…

  1. Adopting Children with Attachment Problems. (United States)

    Hughes, Daniel A.


    Notes that attachment behavior in infants is a facet of normal child development, and that children with attachment problems require special attention during and after the adoption process. Presents actions needed to increase the probability that such children can be successfully adopted, detailed attachment patterns, and parenting strategies and…

  2. Attachment Theory: Retrospect and Prospect. (United States)

    Bretherton, Inge


    Provides overview of attachment theory as parented by John Bowlby in "Attachment and Loss". Uses two major concepts from this work to interpret refinements and elaborations of attachment theory attibuted to Mary Ainsworth. Considers how recent insights into development of socioemotional understanding and development of event representation can be…

  3. Electron attachment to oxygen clusters studied with high energy resolution (United States)

    Matejcik, S.; Stampfli, P.; Stamatovic, A.; Scheier, P.; Märk, T. D.


    Highly monochromatized electrons (with energy distributions of less than 30 meV FWHM) are used in a crossed beam experiments to investigate electron attachment to oxygen clusters (O2)n at electron energies from approximately zero eV up to several eV. At energies close to zero the attachment cross section for the reaction (O2)n+e→(O2)m- (for m=1, 2, and 3) rises strongly with decreasing electron energy compatible with s-wave electron capture to (O2)n. Peaks in the oxygen attachment cross sections present at higher energies (≈80 meV, 193 meV, 302 meV) can be ascribed to vibrational levels of the anion populated by attachment of an electron to a single oxygen molecule within the target cluster via a direct Franck-Condon transition from the ground vibrational state v=0 to a vibrational excited state v'=7,8,9,… of the anion produced. The vibrational structures observed here for the first time can be quantitatively accounted for by model calculations using a microscopic model to examine the attachment of an electron to an oxygen molecule inside a cluster. This involves (i) molecular dynamics simulations to calculate the structure of neutral clusters prior to the attachment process and (ii) calculation of the solvation energy of an oxygen anion in the cluster from the electrostatic polarization of the molecules of the cluster. The occurrence of this polarization energy at the surface of larger clusters explains the appearance of an s-wave capturing cross section at 0 eV and the slightly smaller spacings (compared to the monomer case) between the peaks at finite energy, as observed experimentally. The relative transition probabilities from the ground state of the neutral oxygen molecule to the different vibrational levels of the anion are obtained by calculating the corresponding Franck-Condon factors thereby resulting in a reasonable theoretical fit to the observed yields of negatively charged oxygen molecules and clusters.

  4. Electron attachment to the SF{sub 6} molecule

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, B. M., E-mail:; Kosarim, A. V. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)


    Various models for transition between electron and nuclear subsystems are compared in the case of electron attachment to the SF{sub 6} molecule. Experimental data, including the cross section of electron attachment to this molecule as a function of the electron energy and vibrational temperature, the rate constants of this process in swarm experiments, and the rates of the chemionization process involving Rydberg atoms and the SF{sub 6} molecule, are collected and treated. Based on the data and on the resonant character of electron capture into an autodetachment ion state in accordance with the Breit–Wigner formula, we find that intersection of the molecule and negative ion electron terms proceeds above the potential well bottom of the molecule with the barrier height 0.05–0.1 eV, and the transition between these electron terms has both the tunnel and abovebarrier character. The limit of small electron energies e for the electron attachment cross section at room vibrational temperature takes place at ε ≪ 2 meV, while in the range 2 meV ≪ ε ≪ 80 meV, the cross section is inversely proportional to ε. In considering the attachment process as a result of the interaction between the electron and vibrational degrees of freedom, we find the coupling factor f between them to be f = aT at low vibrational temperatures T with a ≈ 3 × 10{sup −4} K{sup −1}. The coupling factor is independent of the temperature at T > 400 K.

  5. Report of the APSAC task force on attachment therapy, reactive attachment disorder, and attachment problems. (United States)

    Chaffin, Mark; Hanson, Rochelle; Saunders, Benjamin E; Nichols, Todd; Barnett, Douglas; Zeanah, Charles; Berliner, Lucy; Egeland, Byron; Newman, Elana; Lyon, Tom; LeTourneau, Elizabeth; Miller-Perrin, Cindy


    Although the term attachment disorder is ambiguous, attachment therapies are increasingly used with children who are maltreated, particularly those in foster care or adoptive homes. Some children described as having attachment disorders show extreme disturbances. The needs of these children and their caretakers are real. How to meet their needs is less clear. A number of attachment-based treatment and parenting approaches purport to help children described as attachment disordered. Attachment therapy is a young and diverse field, and the benefits and risks of many treatments remain scientifically undetermined. Controversies have arisen about potentially harmful attachment therapy techniques used by a subset of attachment therapists. In this report, the Task Force reviews the controversy and makes recommendations for assessment, treatment, and practices. The report reflects American Professional Society on the Abuse of Children's (APSAC) position and also was endorsed by the American Psychological Association's Division 37 and the Division 37 Section on Child Maltreatment.

  6. Experimental Study on Piezoelectric Energy Harvesting from Vortex-Induced Vibrations and Wake-Induced Vibrations

    Directory of Open Access Journals (Sweden)

    Min Zhang


    Full Text Available A rigid circular cylinder with two piezoelectric beams attached on has been tested through vortex-induced vibrations (VIV and wake-induced vibrations (WIV by installing a big cylinder fixed upstream, in order to study the influence of the different flow-induced vibrations (FIV types. The VIV test shows that the output voltage increases with the increases of load resistance; an optimal load resistance exists for the maximum output power. The WIV test shows that the vibration of the small cylinder is controlled by the vortex frequency of the large one. There is an optimal gap of the cylinders that can obtain the maximum output voltage and power. For a same energy harvesting device, WIV has higher power generation capacity; then the piezoelectric output characteristics can be effectively improved.

  7. Attachment is a dynamic system

    Directory of Open Access Journals (Sweden)

    Zlatka Cugmas


    Full Text Available On the basis of the study of recent scientific literature about the development of attachment, the author answers the following questions: which are the postulates the theory of attachment has about the stability of the patterns of attachment, which level of stability in the patterns of attachment from infancy to adulthood these studies illuminate and which factors significantly influence the (instability of the patterns of attachment in time. The theory of attachment assumes that normal circumstances elicit stability. Changes, however, can be the result of important events influencing the sensitivity of the object of attachment. Agreement has not yet been reached regarding the percentage of stability in the patterns of attachment. There is more agreement regarding attachment in adulthood than that in childhood. The results depend on the size and characteristics of the subjects of the research, the measuring instruments, type of data analysis etc. The author concludes that attachment is a dynamic system influenced by significant changes in life (the cognitive development of the child, external care, parents' divorce, different stressful situations. As the influence of stressful events on the individual person' s quality of attachment is examined, it is necessary to consider also his/her temperamental characteristics, role of other people in their lives, etc.

  8. Attachment Theory in Tourism

    Directory of Open Access Journals (Sweden)

    Maximiliano Korstanje


    Full Text Available The following work is intended to a revision on attachment theory. The postulates of the theory of the sure base point that the system of exploration meets in narrow relation the system of conducts of attachment and the figure of the keepers. The conducts that characterize and symbolize the relation of the adult with the environment are carried back to the early age, in the moment in which the child develops the affective capacity. What difference does exist between someone who decides to journey to England and that one that one decides to travel to Mar del Plata? How it is possible to study this topic of on a manner trustworthy? These three questions were key to begin the investigation. Nevertheless, the matter began to find certain limitations linked to the methodology that had to be in use. It is possible to use careless they on the leisure scope, a theory which still demonstrates certain inconsistencies in its own clinical application?

  9. Behavior of Cell on Vibrating Micro Ridges

    Directory of Open Access Journals (Sweden)

    Haruka Hino


    Full Text Available The effect of micro ridges on cells cultured at a vibrating scaffold has been studied in vitro. Several parallel lines of micro ridges have been made on a disk of transparent polydimethylsiloxane for a scaffold. To apply the vibration on the cultured cells, a piezoelectric element was attached on the outside surface of the bottom of the scaffold. The piezoelectric element was vibrated by the sinusoidal alternating voltage (Vp-p < 16 V at 1.0 MHz generated by a function generator. Four kinds of cells were used in the test: L929 (fibroblast connective tissue of C3H mouse, Hepa1-6 (mouse hepatoma, C2C12 (mouse myoblast, 3T3-L1 (mouse fat precursor cells. The cells were seeded on the micro pattern at the density of 2000 cells/cm2 in the medium containing 10% FBS (fetal bovine serum and 1% penicillin/ streptomycin. After the adhesion of cells in several hours, the cells are exposed to the ultrasonic vibration for several hours. The cells were observed with a phase contrast microscope. The experimental results show that the cells adhere, deform and migrate on the scaffold with micro patterns regardless of the ultrasonic vibration. The effects of the vibration and the micro pattern depend on the kind of cells.

  10. Mechanical vibration to electrical energy converter (United States)

    Kellogg, Rick Allen; Brotz, Jay Kristoffer


    Electromechanical devices that generate an electrical signal in response to an external source of mechanical vibrations can operate as a sensor of vibrations and as an energy harvester for converting mechanical vibration to electrical energy. The devices incorporate a magnet that is movable through a gap in a ferromagnetic circuit, wherein a coil is wound around a portion of the ferromagnetic circuit. A flexible coupling is used to attach the magnet to a frame for providing alignment of the magnet as it moves or oscillates through the gap in the ferromagnetic circuit. The motion of the magnet can be constrained to occur within a substantially linear range of magnetostatic force that develops due to the motion of the magnet. The devices can have ferromagnetic circuits with multiple arms, an array of magnets having alternating polarity and, encompass micro-electromechanical (MEM) devices.

  11. Magnetoelastic metastructures for passive broadband vibration suppression (United States)

    Hobeck, Jared D.; Inman, Daniel J.


    This paper presents an experimental and theoretical analysis of a novel metamaterial-inspired distributed vibration suppression system. The proposed research takes advantage of uniquely designed cantilevered zigzag structures that can have natural frequencies orders of magnitude lower than a simple cantilever of the same scale. A key advantage of the proposed vibration suppression system is that the dynamic response of each zigzag structure can be made highly nonlinear with the use of magnets. Arrays of these compact linear and nonlinear zigzag structures are integrated into a host structure to form what is referred to here as a metastructure. The proposed and experimentally validated analytical model employs a Rayleigh-Ritz formulation for a linear metastructure represented as a cantilever beam with a distributed array of attached single degree of freedom oscillators. These attached oscillators are lumped parameter representations of the zigzag structures. Experimental modal analysis results are shown comparing the response of the nonlinear metastructure to that of both the linear metastructure and also to the host structure with no vibration suppression. Results show that the linear system can reduce the maximum response of the host structure by 41.0% while the nonlinear system can achieve over twice that with a reduction of 84.5%. These promising preliminary results provide motivation for future work to be focused on developing nonlinear metastructures for vibration suppression.

  12. Structural Vibration Control Using Solid Particle Damper

    Directory of Open Access Journals (Sweden)

    Haseena. A


    Full Text Available In this paper the effectiveness of a solid particle damper to control structural vibration is experimentally investigated. The vibration control performance and its influencing parameters are examined by a Multi Degree of Freedom (MDOF structure attached with a particle damper (PD under horizontal excitation. In a particle damping system damping is achieved using solid particles or granules and is a passive damping method. Here the enclosure filled with particles is attached to the primary structure undergoing vibration. As the primary structure vibrates, particles undergo inelastic collision within the enclosure resulting high amount of energy dissipation. Based on the analytical study of undamped frame in ANSYS WORKBENCH, dimensions of the frame were fixed and shake table study of a two storied steel frame with and without damper system are carried out. Results shows that effectiveness of damping depends on various parameters like mass, particle size, shape etc. The effectiveness is compared with a friction damper (FD and is observed that PD is more efficient than FD since 31.80% energy is dissipated more in PD compared to FD

  13. In situ, controlled and reproducible attachment of carbon nanotubes onto conductive AFM tips

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jianxun [International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Chinese Academy of Science Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafty, National Center for Nanoscience and Technology of China, No. 11, Bei yi tiao, Zhong Guan Cun, Beijing 100190 (China); Shingaya, Yoshitaka [International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Zhao, Yuliang [Chinese Academy of Science Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafty, National Center for Nanoscience and Technology of China, No. 11, Bei yi tiao, Zhong Guan Cun, Beijing 100190 (China); Nakayama, Tomonobu, E-mail: [International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)


    Graphical abstract: - Highlights: • An effective and controllable method was developed to fabricate CNT AFM probes in-situ. • Individual carbon nanotube was assembled. • The alignment angle and protruding length of as-produced CNT probes are excellent. - Abstract: Owing to the small diameter, wear resistance, high aspect ratio of their cylindrical structure and outstanding young's modulus, carbon nanotubes are regarded as excellent probes for atomic force microscope (AFM) imaging and various applications. To take the best out of carbon nanotubes’ potentials as AFM probes, we present a facile and reliable method to attach a single carbon nanotube onto an AFM probe covered with conductive Au layer. The method involves the following steps: positioning the AFM probe exactly onto a designated multiple-walled carbon nanotube growing vertically on a conductive substrate, establishing physical contact of the probe apex to the carbon nanotube with an appropriate force, and finally flowing a DC current of typically 100 μA from the AFM probe to the substrate through the carbon nanotube. The current flow results in the fracture and attachment of the carbon nanotube onto the AFM probe. Our method is similar to that reported in previous studies to cut and assemble carbon nanotubes by flowing current under SEM, but by our method we succeed to achieve superior control of protruding length and reproducible attachment angle of the carbon nanotube in one step. Moreover, it is now possible to reliably prepare carbon nanotube probes in-situ during AFM experiments.

  14. Borderline disorder and attachment pathology. (United States)

    West, M; Keller, A; Links, P; Patrick, J


    In this paper, the authors investigate the theoretical and empirical association between dysfunctions of the attachment system and borderline personality disorder. Attachment theory focuses on the maintenance of a sense of safety and security through a close personal relationship with a particular person. Based on a biological behavioural system, functional attachment relationships in adulthood rely on experiences and expectations of security within the relationship. These issues are also important to the definition and dynamics of borderline personality disorder. The dimensions and patterns of reciprocal attachment were compared with other scales measuring components of psychopathology and interpersonal relationships. In a sample of 85 female outpatients, only four of the attachment scales--feared loss, secure base, compulsive care-seeking and angry withdrawal--identified patients with high scores on a measure of borderline disorder. Of these four scales, feared loss had the predominant effect. These empirical results support the hypothesized relationship between dysfunctions of the attachment system and borderline disorder.

  15. Sentence-Level Attachment Prediction (United States)

    Albakour, M.-Dyaa; Kruschwitz, Udo; Lucas, Simon

    Attachment prediction is the task of automatically identifying email messages that should contain an attachment. This can be useful to tackle the problem of sending out emails but forgetting to include the relevant attachment (something that happens all too often). A common Information Retrieval (IR) approach in analyzing documents such as emails is to treat the entire document as a bag of words. Here we propose a finer-grained analysis to address the problem. We aim at identifying individual sentences within an email that refer to an attachment. If we detect any such sentence, we predict that the email should have an attachment. Using part of the Enron corpus for evaluation we find that our finer-grained approach outperforms previously reported document-level attachment prediction in similar evaluation settings.

  16. Attachment and Outcomes in Life

    Directory of Open Access Journals (Sweden)

    Neslim Guvendeger Doksat


    Full Text Available The term and ldquo;attachment and rdquo; is used to imply the bonding between mother and child or the relationship between parents and child. Establishment of secure attachment is the healthiest way for the mental and physical development of the child. Secure attachment system constitutes a protection mechanism from high levels of stress. Insecurely attached children are presented with mental and physical developmental delays and problems in identity formation and personality in the future. To avoid all these, all the requirements of the child by means of affection, nutrition, protection, shelter and health are required to be met in a consistent and healthy way by the caregiver. This review article discuss the term attachment; features associated with insecure attachment and its negative influences in adulthood. [Archives Medical Review Journal 2016; 25(4.000: 489-501


    Institute of Scientific and Technical Information of China (English)

    HU Hong; SHI Hongyan; BEN MRAD Ridha


    A novel active Vibration control technique on the basis of linearized piezoelectric actuators is presented. An experimental apparatus consisting of a cantilever beam to which are attached strain patches and piezoceramic actuators to be used for active Vibration suppression is described. A dynamical model of the cantilever beam using Lagrange's equation and two coordinate Systems are presented. Based on the Lyapunov's direct method, an active Vibration Controller with hysteresis compensation is designed. The Controller is designed so that it guarantees the global stability of the overall System. The Controller developed is assessed experimentally.

  18. Characterization of Akiyama probe applied to dual-probes atomic force microscope (United States)

    Wang, Hequn; Gao, Sitian; Li, Wei; Shi, Yushu; Li, Qi; Li, Shi; Zhu, Zhendong


    The measurement of nano-scale line-width has always been important and difficult in the field of nanometer measurements, while the rapid development of integrated circuit greatly raises the demand again. As one kind of scanning probe microscope (SPM), atomic force microscope (AFM) can realize quasi three-dimensional measurement, which is widely used in nanometer scale line-width measurement. Our team researched a dual-probes atomic force microscope, which can eliminate the prevalent effect of probe width on measurement results. In dual-probes AFM system, a novel head are newly designed. A kind of self-sensing and self-exciting probes which is Nanosensors cooperation's patented probe—Akiyama probe, is used in this novel head. The Akiyama probe applied to dual-probe atomic force microscope is one of the most important issues. The characterization of Akiyama probe would affect performance and accuracy of the whole system. The fundamental features of the Akiyama probe are electrically and optically characterized in "approach-withdraw" experiments. Further investigations include the frequency response of an Akiyama probe to small mechanical vibrations externally applied to the tip and the effective loading force yielding between the tip and the sample during the periodic contact. We hope that the characterization of the Akiyama probe described in this paper will guide application for dual-probe atomic force microscope.

  19. Adult attachment and psychosocial functioning


    Pielage, Suzanne Brenda


    In the trilogy Attachment, Separation and Loss (1969, 1973, 1980), Bowlby theorized that early experiences with caregivers affect the quality of individuals’ later (romantic) relationships and, consequently, their mental health. The current thesis set out to examine the relationships between adult attachment and psychosocial functioning, predominately in the realm of close relationships. In the first part of the thesis, the focus lay on the assessment of the adult attachment construct. In Cha...

  20. Attachment-security priming attenuates amygdala activation to social and linguistic threat. (United States)

    Norman, Luke; Lawrence, Natalia; Iles, Andrew; Benattayallah, Abdelmalek; Karl, Anke


    A predominant expectation that social relationships with others are safe (a secure attachment style), has been linked with reduced threat-related amygdala activation. Experimental priming of mental representations of attachment security can modulate neural responding, but the effects of attachment-security priming on threat-related amygdala activation remains untested. Using functional magnetic resonance imaging, the present study examined the effects of trait and primed attachment security on amygdala reactivity to threatening stimuli in an emotional faces and a linguistic dot-probe task in 42 healthy participants. Trait attachment anxiety and attachment avoidance were positively correlated with amygdala activation to threatening faces in the control group, but not in the attachment primed group. Furthermore, participants who received attachment-security priming showed attenuated amygdala activation in both the emotional faces and dot-probe tasks. The current findings demonstrate that variation in state and trait attachment security modulates amygdala reactivity to threat. These findings support the potential use of attachment security-boosting methods as interventions and suggest a neural mechanism for the protective effect of social bonds in anxiety disorders.

  1. Attachment disorganization in different clinical groups: What underpins unresolved attachment?

    Directory of Open Access Journals (Sweden)

    Juen Florian


    Full Text Available This paper summarizes findings and clinical implications of research on attachment disorganization in diverse clinical groups. Disorganized/unresolved attachment is overrepresented in these groups compared to healthy control participants, but disorder specific characteristics of this attachment pattern are still poorly understood. The focus of this study was to explore defensive processes in participants whose narratives were classified as disorganized/unresolved using the Adult Attachment Projective Picture System (AAP. Besides the predominance of disorganized attachment, clinical participants demonstrated more “segregated system material” especially in stories representing aloneness and more “Personal Experience material” compared to healthy individuals. Within the disorganized/ unresolved clinical individuals, BPD and PTSD patients showed the highest proportion of attachment disorganization and were less able to use other attachment-related defenses to maintain organized. Furthermore, PTSD patients were emotionally overwhelmed by the projective attachment scenes compared to the other clinical groups as indexed by an incapacity to complete sections of the AAP. BPD and addicted patients were characterized by a high degree of self-other boundary confusion. Depressive and schizophrenic patients showed a high overall defensive intensity to remain organized.

  2. Portable vibration exciter (United States)

    Beecher, L. C.; Williams, F. T.


    Gas-driven vibration exciter produces a sinusoidal excitation function controllable in frequency and in amplitude. It allows direct vibration testing of components under normal loads, removing the possibility of component damage due to high static pressure.

  3. Parallel scanning probe arrays: their applications

    Directory of Open Access Journals (Sweden)

    Chang Liu


    Full Text Available Since the invention of the scanning tunneling microscope (STM1 and the atomic force microscope (AFM2, the field of scanning probe microscopy (SPM instruments has grown steadily and has had a profound influence in materials research, chemistry, biology, nanotechnology, and electronics3,4. Today, scanning probe instruments are used for metrology, characterization5, detection6, manipulation7, patterning8,9, and material modification. A wide range of scanning probe applications are available, taking advantage of various modes of tip–substrate interactions, including force, optics10,11, electrochemistry12, electromagnetics, electrostatics, thermal and mass transfer13,14, and vibration15,16.

  4. Dissociative Electron Attachment (United States)

    Arreola, Esmeralda; Esmeralda Arreola Collaboration; Leigh Hargreaves Collaboration

    Since the pioneering work of Boudiaffa et al., it has been understood that electrons, even with energies near or below the ionization threshold, are capable of initiating strand-breaks in human DNA. This discovery raised important questions for cancer treatments, since sub-ionizing electrons are known to be the most copiously produced secondary product of radiation therapy. But even to date these factors are largely excluded from dosimetry calculations. This lack of inclusion is, at least in part, certainly due to the dearth of fundamental data describing low-energy electron interactions with nucleotide molecules that form the basis of DNA. Understanding of how such slow electrons are able to damage DNA remains incomplete, but the strongly peaked nature of Boudiaffa et al.'s data gives strong hints at resonantly driven collision processes. DNA damage is therefore most likely driven by ``dissociative electron attachment'' (DEA). DEA is a rather complicated process to model due to the coupling of electronic and nuclear degrees of freedom in the molecule. At the California State University Fullerton, we are currently commissioning a new spectrometer to study dissociation channels, reaction rates and orientation effects in DEA collisions between slow electrons and nucleotide molecules. At the meeting we will present design parameters and commissioning data for this new apparatus.

  5. Protein Attachment on Nanodiamonds. (United States)

    Lin, Chung-Lun; Lin, Cheng-Huang; Chang, Huan-Cheng; Su, Meng-Chih


    A recent advance in nanotechnology is the scale-up production of small and nonaggregated diamond nanoparticles suitable for biological applications. Using detonation nanodiamonds (NDs) with an average diameter of ∼4 nm as the adsorbents, we have studied the static attachment of three proteins (myoglobin, bovine serum albumin, and insulin) onto the nanoparticles by optical spectroscopy, mass spectrometry, and dynamic light scattering, and electrophoretic zeta potential measurements. Results show that the protein surface coverage is predominantly determined by the competition between protein-protein and protein-ND interactions, giving each protein a unique and characteristic structural configuration in its own complex. Specifically, both myoglobin and bovine serum albumin show a Langmuir-type adsorption behavior, forming 1:1 complexes at saturation, whereas insulin folds into a tightly bound multimer before adsorption. The markedly different adsorption patterns appear to be independent of the protein concentration and are closely related to the affinity of the individual proteins for the NDs. The present study provides a fundamental understanding for the use of NDs as a platform for nanomedical drug delivery.

  6. Conductivity Probe (United States)


    The Thermal and Electrical Conductivity Probe (TECP) for NASA's Phoenix Mars Lander took measurements in Martian soil and in the air. The needles on the end of the instrument were inserted into the Martian soil, allowing TECP to measure the propagation of both thermal and electrical energy. TECP also measured the humidity in the surrounding air. The needles on the probe are 15 millimeters (0.6 inch) long. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  7. Mirror Metrology Using Nano-Probe Supports (United States)

    Robinson, David; Hong, Maoling; Byron, Glenn; McClelland, Ryan; Chan, Kai-Wing


    Thin, lightweight mirrors are needed for future x-ray space telescopes in order to increase x-ray collecting area while maintaining a reduced mass and volume capable of being launched on existing rockets. However, it is very difficult to determine the undistorted shape of such thin mirrors because the mounting of the mirror during measurement causes distortion. Traditional kinematic mounts have insufficient supports to control the distortion to measurable levels and prevent the mirror from vibrating during measurement. Over-constrained mounts (non-kinematic) result in an unknown force state causing mirror distortion that cannot be determined or analytically removed. In order to measure flexible mirrors, it is necessary to over-constrain the mirror. Over-constraint causes unknown distortions to be applied to the mirror. Even if a kinematic constraint system can be used, necessary imperfections in the kinematic assumption can lead to an unknown force state capable of distorting the mirror. Previously, thicker, stiffer, and heavier mirrors were used to achieve low optical figure distortion. These mirrors could be measured to an acceptable level of precision using traditional kinematic mounts. As lighter weight precision optics have developed, systems such as the whiffle tree or hydraulic supports have been used to provide additional mounting supports while maintaining the kinematic assumption. The purpose of this invention is to over-constrain a mirror for optical measurement without causing unacceptable or unknown distortions. The invention uses force gauges capable of measuring 1/10,000 of a Newton attached to nano-actuators to support a thin x-ray optic with known and controlled forces to allow for figure measurement and knowledge of the undeformed mirror figure. The mirror is hung from strings such that it is minimally distorted and in a known force state. However, the hanging mirror cannot be measured because it is both swinging and vibrating. In order to

  8. Attachment, caring and prosocial behavior

    NARCIS (Netherlands)

    Erez, Ayelet


    The thesis focuses on 5 studies examining the role of adult attachment in volunteering by defining volunteerism as a form of caregiving. By that we suggest an effect of one behavioral system, attachment, on another, caring or prosocial behaviors in individual or group settings. Studies 1 and 2 ex

  9. Coherent acoustic vibration of metal nanoshells. (United States)

    Guillon, C; Langot, P; Del Fatti, N; Vallée, F; Kirakosyan, A S; Shahbazyan, T V; Cardinal, T; Treguer, M


    Using time-resolved pump-probe spectroscopy, we have performed the first investigation of the vibrational modes of gold nanoshells. The fundamental isotropic mode launched by a femtosecond pump pulse manifests itself in a pronounced time-domain modulation of the differential transmission probed at the frequency of nanoshell surface plasmon resonance. The modulation amplitude is significantly stronger, and the period is longer than that in a gold nanoparticle of the same overall size, in agreement with theoretical calculations. This distinct acoustical signature of nanoshells provides a new and efficient method for identifying these versatile nanostructures and for studying their mechanical and structural properties.

  10. Attachment styles in alcoholic inpatients. (United States)

    De Rick, Ann; Vanheule, Stijn


    Despite the fact that addiction has often been identified as an attachment disorder, empirical studies on this topic are rather scarce. In our study we explore attachment style (secure vs. insecure) in alcoholic inpatients and its relationship with perceived parenting and alcohol-related and psychiatric problems in a sample of 101 alcoholic inpatients (Belgium). Our results reveal that in comparison to the securely-attached group, insecurely-attached alcoholic inpatients perceived their mother as more controlling, reported more severe psychiatric problems in the European Addiction Severity Index, had higher scores on the Beck Depression Inventory, showed more schizotypal and depressive personality traits and had more difficulties with communicating emotions (alexithymia). We argue that it makes sense to differentiate alcoholic inpatients on the basis of attachment style and that both groups (secure/insecure) need different treatment approaches.

  11. Wideband Piezomagnetoelastic Vibration Energy Harvesting

    DEFF Research Database (Denmark)

    Lei, Anders; Thomsen, Erik Vilain


    This work presents a small-scale wideband piezomagnetoelastic vibration energy harvester (VEH) aimed for operation at frequencies of a few hundred Hz. The VEH consists of a tape-casted PZT cantilever with thin sheets of iron foil attached on each side of the free tip. The wideband operation...... softening effect. In linear operation (without magnets) the harvester generates a RMS power of 141 μW/g2 at 588 Hz with a relative bandwidth of 3.8% over a 100 kΩ load resistor. When operated with one magnet ideally positioned opposite the cantilever, a RMS power of 265 μW/g2 is generated at 270 Hz...

  12. Pollution Probe. (United States)

    Chant, Donald A.

    This book is written as a statement of concern about pollution by members of Pollution Probe, a citizens' anti-pollution group in Canada. Its purpose is to create public awareness and pressure for the eventual solution to pollution problems. The need for effective government policies to control the population explosion, conserve natural resources,…

  13. Nonlinear targeted energy transfer of two coupled cantilever beams coupled to a bistable light attachment (United States)

    Mattei, P.-O.; Ponçot, R.; Pachebat, M.; Côte, R.


    In order to control the sound radiation by a structure, one aims to control vibration of radiating modes of vibration using "Energy Pumping" also named "Targeted Energy Transfer". This principle is here applied to a simplified model of a double leaf panel. This model is made of two beams coupled by a spring. One of the beams is connected to a nonlinear absorber. This nonlinear absorber is made of a 3D-printed support on which is clamped a buckled thin small beam with a small mass fixed at its centre having two equilibrium positions. The experiments showed that, once attached onto a vibrating system to be controlled, under forced excitation of the primary system, the light bistable oscillator allows a reduction of structural vibration up to 10 dB for significant amplitude and frequency range around the first two vibration modes of the system.

  14. Transient vibration analytical modeling and suppressing for vibration absorber system under impulse excitation (United States)

    Wang, Xi; Yang, Bintang; Yu, Hu; Gao, Yulong


    The impulse excitation of mechanism causes transient vibration. In order to achieve adaptive transient vibration control, a method which can exactly model the response need to be proposed. This paper presents an analytical model to obtain the response of the primary system attached with dynamic vibration absorber (DVA) under impulse excitation. The impulse excitation which can be divided into single-impulse excitation and multi-impulse excitation is simplified as sinusoidal wave to establish the analytical model. To decouple the differential governing equations, a transform matrix is applied to convert the response from the physical coordinate to model coordinate. Therefore, the analytical response in the physical coordinate can be obtained by inverse transformation. The numerical Runge-Kutta method and experimental tests have demonstrated the effectiveness of the analytical model proposed. The wavelet of the response indicates that the transient vibration consists of components with multiple frequencies, and it shows that the modeling results coincide with the experiments. The optimizing simulations based on genetic algorithm and experimental tests demonstrate that the transient vibration of the primary system can be decreased by changing the stiffness of the DVA. The results presented in this paper are the foundations for us to develop the adaptive transient vibration absorber in the future.

  15. Vibration of hydraulic machinery

    CERN Document Server

    Wu, Yulin; Liu, Shuhong; Dou, Hua-Shu; Qian, Zhongdong


    Vibration of Hydraulic Machinery deals with the vibration problem which has significant influence on the safety and reliable operation of hydraulic machinery. It provides new achievements and the latest developments in these areas, even in the basic areas of this subject. The present book covers the fundamentals of mechanical vibration and rotordynamics as well as their main numerical models and analysis methods for the vibration prediction. The mechanical and hydraulic excitations to the vibration are analyzed, and the pressure fluctuations induced by the unsteady turbulent flow is predicted in order to obtain the unsteady loads. This book also discusses the loads, constraint conditions and the elastic and damping characters of the mechanical system, the structure dynamic analysis, the rotor dynamic analysis and the system instability of hydraulic machines, including the illustration of monitoring system for the instability and the vibration in hydraulic units. All the problems are necessary for vibration pr...

  16. University scientists test Mars probe equipment

    CERN Multimedia


    Scientists at Leicester University have spent four years researching and designing the Flight Model Position Adjustable Workbench (PAW) at the university. It will be attached to the Beagle 2 probe before being sent to the Red Planet in the spring (1/2 page).

  17. Vibration and Acoustic Radiation from Submerged Spherical Double-Shell

    Institute of Scientific and Technical Information of China (English)

    陈军明; 黄玉盈; 陈应波


    Based on the motion differential equations of vibration and acoustic coupling system for a thin elastic spherical double-shell with several elastic plates attached to the shells, in which Dirac-δ functions are employed to introduce the forces and moments applied by the attachments, and by means of expanding field quantities as the Legendre series, a semi-analytic solution is derived for the solution to the vibration and acoustic radiation from a submerged spherical double-shell. This solution has a satisfying computational effectiveness and precision for arbitrary frequency range excitation. It is concluded that the internal plates attached to shells can change significantly the mechanical and acoustical characteristics of shells, and make the coupling system have a very rich resonance frequency spectrum. Moreover, the present method can be used to study the acoustic radiation mechanism of the type of structure.

  18. The effect of vibration on bed voidage behaviors in fluidized beds with large particles

    Energy Technology Data Exchange (ETDEWEB)

    Jin, H.; Zhang, J.; Zhang, B.


    The effects of vibration parameters, operating conditions and material properties on bed voidage were investigated using an optical fiber probe approach in a vibrating fluidized bed with a diameter of 148 mm. Variables studied included frequency (0-282 s{sup -1}), amplitude (0 mm-1 mm), bed height (0.1 m-0.4 m) as well as four kinds of particles (belonging to Geldart's B and D groups). The axial and radial voidage distribution with vibration is compared with that without vibration, which shows vibration can aid in the fluidization behaviors of particles. For a larger vibration amplitude, the vibration seriously affects bed voidage. The vibration energy can damp out for particle layers with increasing the bed height. According to analysis of experimental data, an empirical correlation for predicting bed voidage, giving good agreement with the experimental data and a deviation within {+-}15%, was proposed. 20 refs., 8 figs., 2 tabs.

  19. The effect of vibration on bed voidage behaviors in fluidized beds with large particles

    Directory of Open Access Journals (Sweden)

    H. Jin


    Full Text Available The effects of vibration parameters, operating conditions and material properties on bed voidage were investigated using an optical fiber probe approach in a vibrating fluidized bed with a diameter of 148 mm. Variables studied included frequency (0-282 s-1, amplitude (0 mm-1 mm, bed height (0.1 m-0.4 m as well as four kinds of particles (belonging to Geldart's B and D groups. The axial and radial voidage distribution with vibration is compared with that without vibration, which shows vibration can aid in the fluidization behaviors of particles. For a larger vibration amplitude, the vibration seriously affects bed voidage. The vibration energy can damp out for particle layers with increasing the bed height. According to analysis of experimental data, an empirical correlation for predicting bed voidage, giving good agreement with the experimental data and a deviation within ±15%, was proposed.

  20. Everything You Want To Know about Attachment. (United States)

    Honig, Alice Sterling

    This paper discusses infant attachment, which it defines as a long-lasting emotional bond revealed when a child under stress seeks out and tries to stay close to a specific figure. The paper addresses: (1) What is attachment? Who are the pioneers in attachment theory?; (2) How do we notice attachment in action?; (3) Is attachment the only…

  1. Electron Attachment to Oxygen and Nitric-Oxide Clusters with High Energy Resolution (United States)

    Scheier, P.; Senn, G.; Stampfli, P.; Mńrk, T. D.; Chu, Y.; Matejcik, S.; Stamatovic, A.; Illenberger, E.

    Highly monochrornatized electrons (with energy distributions of less than 15 meV FWHM) are used in a crossed beams experiment to investigate electron attachment to oxygen clusters (O2)n and nitric-oxide clusters (NO)n at electron energies from approximately zero eV up to several eV. At energies close to zero the attachment cross section for the reaction (X)n + e → X- (for X=O2 and NO, respectively) rises strongly with decreasing electron energy compatible with s-wave electron capture to Xn. Peaks in the oxygen attachment cross sections present at higher energies (80 meV, 193 meV,…) can be ascribed to vibrational levels of the anion. The vibrational spacings observed can be quantitatively accounted for by model calculations. In contrast, peaks at higher energies (220 meV, 440 meV,…) in the dissociative attachment cross sections for NOn are due to direct excitation of the vibrational levels in neutral NO prior to localization of the excess charge in the cluster (vibrational autoscavenging).


    Energy Technology Data Exchange (ETDEWEB)

    Brooks Pate


    The Vibrational Spectroscopy conference focuses on using vibrational spectroscopy to probe structure and dynamics of molecules in gases, liquids, and at interfaces. The conference explores the wide range of state-of-the-art techniques based on vibrational motion. These techniques span the fields of time-domain, high-resolution frequency-domain, spatially-resolved, nonlinear and multidimensional spectroscopies. The conference highlights the application of these techniques in chemistry, materials, biology, and medicine. The theory of molecular vibrational motion and its connection to spectroscopic signatures and chemical reaction dynamics is the third major theme of the meeting. The goal is to bring together a collection of researchers who share common interests and who will gain from discussing work at the forefront of several connected areas. The intent is to emphasize the insights and understanding that studies of vibrations provide about a variety of molecular systems ranging from small polyatomic molecules to large biomolecules and nanomaterials.

  3. Ultrafast vibrational energy relaxation of the water bridge. (United States)

    Piatkowski, Lukasz; Wexler, Adam D; Fuchs, Elmar C; Schoenmaker, Hinco; Bakker, Huib J


    We report the energy relaxation of the OH stretch vibration of HDO molecules contained in an HDO:D(2)O water bridge using femtosecond mid-infrared pump-probe spectroscopy. We found that the vibrational lifetime is shorter (~630 ± 50 fs) than for HDO molecules in bulk HDO:D(2)O (~740 ± 40 fs). In contrast, the thermalization dynamics following the vibrational relaxation are much slower (~1.5 ± 0.4 ps) than in bulk HDO:D(2)O (~250 ± 90 fs). These differences in energy relaxation dynamics strongly indicate that the water bridge and bulk water differ on a molecular scale.

  4. Thermal Vibrational Convection (United States)

    Gershuni, G. Z.; Lyubimov, D. V.


    Recent increasing awareness of the ways in which vibrational effects can affect low-gravity experiments have renewed interest in the study of thermal vibrational convection across a wide range of fields. For example, in applications where vibrational effects are used to provide active control of heat and mass transfer, such as in heat exchangers, stirrers, mineral separators and crystal growth, a sound understanding of the fundamental theory is required. In Thermal Vibrational Convection, the authors present the theory of vibrational effects caused by a static gravity field, and of fluid flows which appear under vibration in fluid-filled cavities. The first part of the book discusses fluid-filled cavities where the fluid motion only appears in the presence of temperature non-uniformities, while the second considers those situations where the vibrational effects are caused by a non-uniform field. Throughout, the authors concentrate on consideration of high frequency vibrations, where averaging methods can be successfully applied in the study of the phenomena. Written by two of the pioneers in this field, Thermal Vibrational Convection will be of great interest to scientists and engineers working in the many areas that are concerned with vibration, and its effect on heat and mass transfer. These include hydrodynamics, hydro-mechanics, low gravity physics and mechanics, and geophysics. The rigorous approach adopted in presenting the theory of this fascinating and highly topical area will facilitate a greater understanding of the phenomena involved, and will lead to the development of more and better-designed experiments.

  5. Attachment at work and performance. (United States)

    Neustadt, Elizabeth A; Chamorro-Premuzic, Tomas; Furnham, Adrian


    This paper examines the relations between self-reported attachment orientation at work and personality, self-esteem, trait emotional intelligence (aka emotional self-efficacy), and independently assessed career potential and job performance. Self-report data were collected from 211 managers in an international business in the hospitality industry; independent assessments of these managers' job performance and career potential were separately obtained from the organization. A self-report measure of romantic attachment was adapted for application in the work context; a two-factor solution was found for this measure. Secure/autonomous attachment orientation at work was positively related to self-esteem, trait emotional intelligence, extraversion, agreeableness, and conscientiousness, and also to job performance. Not only was secure/autonomous attachment orientation at work statistically predictive of job performance, but the new measure also made a distinct contribution, beyond conscientiousness, to this prediction.

  6. Mapping and measuring place attachment

    DEFF Research Database (Denmark)

    Brown, Greg; Raymond, Christopher Mark; Corcoran, Jonathan


    in a regional study in South Australia. Our research objectives were to (1) analyze and present the spatial results of the mapping method as a benchmark for future research, (2) compare mapped place attachment to the more common practice of mapping landscape values in PPGIS that comprise a values home range, (3......-based measures. The area of place attachment is influenced by occupational roles such as farming or conservation, as well as home location, especially in coastal versus non-coastal contexts. The spatial distribution of mapped landscape values or values home range is related to, but not identical to mapped place......The concept of place attachment has been studied extensively across multiple disciplines but only recently with empirical measurement using public participation GIS (PPGIS) and related crowd-sourcing mapping methods. This research trialed a spatially explicit method for identifying place attachment...

  7. Attachment Narratives in Refugee Children

    DEFF Research Database (Denmark)

    De Haene, L.; Dalgård, Nina Thorup; Montgomery, E.


    J Trauma Stress. 2013 Jun;26(3):413-7. doi: 10.1002/jts.21820. Attachment narratives in refugee children: interrater reliability and qualitative analysis in pilot findings from a two-site study.......J Trauma Stress. 2013 Jun;26(3):413-7. doi: 10.1002/jts.21820. Attachment narratives in refugee children: interrater reliability and qualitative analysis in pilot findings from a two-site study....

  8. Vibrating fuel grapple. [LMFBR (United States)

    Chertock, A.J.; Fox, J.N.; Weissinger, R.B.

    A reactor refueling method is described which utilizes a vibrating fuel grapple for removing spent fuel assemblies from a reactor core. It incorporates a pneumatic vibrator in the grapple head which allows additional withdrawal capability without exceeding the allowable axial force limit. The only moving part in the vibrator is a steel ball, pneumatically driven by a gas, such as argon, around a track, with centrifugal force created by the ball being transmitted through the grapple to the assembly handling socket.

  9. Infrared vibrational nanocrystallography and nanoimaging (United States)

    Muller, Eric A.; Pollard, Benjamin; Bechtel, Hans A.; van Blerkom, Peter; Raschke, Markus B.


    Molecular solids and polymers can form low-symmetry crystal structures that exhibit anisotropic electron and ion mobility in engineered devices or biological systems. The distribution of molecular orientation and disorder then controls the macroscopic material response, yet it is difficult to image with conventional techniques on the nanoscale. We demonstrated a new form of optical nanocrystallography that combines scattering-type scanning near-field optical microscopy with both optical antenna and tip-selective infrared vibrational spectroscopy. From the symmetry-selective probing of molecular bond orientation with nanometer spatial resolution, we determined crystalline phases and orientation in aggregates and films of the organic electronic material perylenetetracarboxylic dianhydride. Mapping disorder within and between individual nanoscale domains, the correlative hybrid imaging of nanoscale heterogeneity provides insight into defect formation and propagation during growth in functional molecular solids. PMID:27730212

  10. Infrared vibrational nanocrystallography and nanoimaging. (United States)

    Muller, Eric A; Pollard, Benjamin; Bechtel, Hans A; van Blerkom, Peter; Raschke, Markus B


    Molecular solids and polymers can form low-symmetry crystal structures that exhibit anisotropic electron and ion mobility in engineered devices or biological systems. The distribution of molecular orientation and disorder then controls the macroscopic material response, yet it is difficult to image with conventional techniques on the nanoscale. We demonstrated a new form of optical nanocrystallography that combines scattering-type scanning near-field optical microscopy with both optical antenna and tip-selective infrared vibrational spectroscopy. From the symmetry-selective probing of molecular bond orientation with nanometer spatial resolution, we determined crystalline phases and orientation in aggregates and films of the organic electronic material perylenetetracarboxylic dianhydride. Mapping disorder within and between individual nanoscale domains, the correlative hybrid imaging of nanoscale heterogeneity provides insight into defect formation and propagation during growth in functional molecular solids.

  11. Vibrational properties of uracil

    Institute of Scientific and Technical Information of China (English)

    WANG Zhiping; ZHANG Fengshou; ZENG Xianghua; ZHOU Hongyu; GU Bin; CHENG Wei


    A semiempirical molecular dynamics model is developed to study the vibrational frequencies of uracil at very low kinetic temperature by using the Fourier transform of velocity autocorrelation function of trajectories of molecular dynamics simulations. The finite difference harmonic method is used to assign the vibrational frequency of each mode. The calculated frequencies are found to be in good agreement with experimental measurements. Moreover, we make up for the lost vibrational modes in experiments self-consistently. A total of 30 vibrational modes and their corresponding frequencies are reported.

  12. Two-dimensional Infrared Spectroscopy of vibrational polaritons of molecules in an optical cavity

    CERN Document Server

    Saurabh, Prasoon


    Strong coupling of molecular vibrations to an infrared cavity mode affects their nature by creating dressed polariton states. We show how the single and double vibrational polariton manifolds may be controlled by varying the cavity coupling strength, and probed by a time domain 2DIR technique, Double Quantum Coherence (DQC). Applications are made to the amide-I ($CO$) and amide-II ($CN$) bond vibrations of $N-methylacetamide$ (NMA).

  13. The vibrational spectrum of the atoms in the grain boundaries of nanocrystalline Pd

    Energy Technology Data Exchange (ETDEWEB)

    Stuhr, U. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Wipf, H.; Hahn, H. [Technische Hochschule Darmstadt (Germany); Natter, H.; Hemperlmann, R. [Universitaet des Saarlandes, Saarbruecken (Germany); Andersen, K. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)


    The vibrational excitations of the atoms in nanocrystalline Pd was investigated by neutron-time-of-flight spectroscopy. Hydrogen was used as a probe for the vibrations in the grain boundaries. The separation between the H and Pd vibrations was done by spin analysis. The results show that in the grain boundary the density of states of low energy excitations ({<=}5 meV) is drastically increased. (author) 3 figs., 3 refs.

  14. Vibration Suppression of an Axially Moving String with Transverse Wind Loadings by a Nonlinear Energy Sink

    Directory of Open Access Journals (Sweden)

    Ye-Wei Zhang


    Full Text Available Nonlinear targeted energy transfer (TET is applied to suppress the excessive vibration of an axially moving string with transverse wind loads. The coupling dynamic equations used are modeled by a nonlinear energy sink (NES attached to the string to absorb vibrational energy. By a two-term Galerkin procedure, the equations are discretized, and the effects of vibration suppression by numerical methods are demonstrated. Results show that the NES can effectively suppress the vibration of the axially moving string with transverse wind loadings, thereby protecting the string from excessive movement.

  15. Formation and stabilization of C6- by radiative electron attachment (United States)

    Chandrasekaran, Vijayanand; Prabhakaran, Aneesh; Kafle, Bhim; Rubinstein, Hilel; Heber, Oded; Rappaport, Michael; Toker, Yoni; Zajfman, Daniel


    Radiative electron attachment (REA) plays an important role in forming molecular anions in various astrophysical environments. In this work, we determined the rate coefficient for the formation of C6- by REA based on a detailed balance approach. C6- ions are stored in an electrostatic ion beam trap and are photoexcited above their adiabatic detachment energy (4.18 eV). Due to fast internal conversion and intramolecular vibrational redistribution, photoexcitation leads to the formation of temporary negative ions (TNIs), the same as those one formed by the electron attachment. Absolute vibrational autodetachment and recurrent (or Poincaré) fluorescence (RF) rate coefficients have already been reported [V. Chandrasekaran et al., J. Phys. Chem. Lett. 5, 4078 (2014)]. Knowing the branching ratios of the various competing rate coefficients is decisive to the understanding of the formation probability of anions via REA. The radiative stabilization rate of C6-, shown to be dominated by RF, was determined to be 5 × 104 s-1 at the electron detachment energy, i.e., at least a factor of 100 faster than the stabilization by infrared transitions. The RF is found to very effectively stabilize the TNI formed by electron attachment. Using detailed balance to link the measured delayed detachment rate to the rate of electron attachment, we estimate the REA rate leading to the formation of C6- to be 3 × 10-7 cm3 s-1 at 300 K in agreement with theory (1.7 × 10-7 cm3 s-1 [R. Terzieva and E. Herbst, Int. J. Mass Spectrom. 201, 135 (2000)]). Such a high rate for REA to C6 indicates that REA may play a prominent role in the formation of anions in the interstellar medium.

  16. Floor Vibrations - as Induced and Reduced by Humans

    DEFF Research Database (Denmark)

    Pedersen, Lars

    . The appropriateness and accuracy of this modelling approach is evaluated. Implications of human-floor interaction are studied with focus on the impact of the interaction on the size of vibration levels of human-occupied floors and on the impact on floor dynamic characteristics. The influence of the interaction......The work is a contribution to the problem of modelling human-induced dynamic loads on floors and to the problem of modelling the interaction between stationary crowds of people and a vibrating floor. Experimental investigations are made to examine, update and refine currently available models....... As for dynamic loads focus is placed on heel impact excitation and actions of jumping people causing floor vibrations. As for interaction between stationary humans and the vibrating floor focus is on modelling humans as oscillating spring-mass-damper systems attached to the floor rather than as simple added mass...

  17. PREFACE: Vibrations at surfaces Vibrations at surfaces (United States)

    Rahman, Talat S.


    This special issue is dedicated to the phenomenon of vibrations at surfaces—a topic that was indispensible a couple of decades ago, since it was one of the few phenomena capable of revealing the nature of binding at solid surfaces. For clean surfaces, the frequencies of modes with characteristic displacement patterns revealed how surface geometry, as well as the nature of binding between atoms in the surface layers, could be different from that in the bulk solid. Dispersion of the surface phonons provided further measures of interatomic interactions. For chemisorbed molecules on surfaces, frequencies and dispersion of the vibrational modes were also critical for determining adsorption sites. In other words, vibrations at surfaces served as a reliable means of extracting information about surface structure, chemisorption and overlayer formation. Experimental techniques, such as electron energy loss spectroscopy and helium-atom-surface scattering, coupled with infra-red spectroscopy, were continually refined and their resolutions enhanced to capture subtleties in the dynamics of atoms and molecules at surfaces. Theoretical methods, whether based on empirical and semi-empirical interatomic potential or on ab initio electronic structure calculations, helped decipher experimental observations and provide deeper insights into the nature of the bond between atoms and molecules in regions of reduced symmetry, as encountered on solid surfaces. Vibrations at surfaces were thus an integral part of the set of phenomena that characterized surface science. Dedicated workshops and conferences were held to explore the variety of interesting and puzzling features revealed in experimental and theoretical investigations of surface vibrational modes and their dispersion. One such conference, Vibrations at Surfaces, first organized by Harald Ibach in Juelich in 1980, continues to this day. The 13th International Conference on Vibrations at Surfaces was held at the University of

  18. Low-energy electron attachment to the dichlorodifluoromethane (CCl2F2) molecule. (United States)

    Graupner, K; Haughey, S A; Field, T A; Mayhew, C A; Hoffmann, T H; May, O; Fedor, J; Allan, M; Fabrikant, I I; Illenberger, E; Braun, M; Ruf, M-W; Hotop, H


    Results from a joint experimental study of electron attachment to dichlorodifluoromethane (CCl(2)F(2)) molecules in the gas phase are reported. In a high resolution electron beam experiment involving two versions of the laser photoelectron attachment method, the relative cross section for formation of the dominant anion Cl(-) was measured over the energy range 0.001-1.8 eV at the gas temperature T(G) = 300 K. It exhibits cusp structure at thresholds for vibrational excitation of the nu(3)(a(1)) mode due to interaction with the attachment channels. With reference to the thermal attachment rate coefficient k(T = 300 K) = 2.2(8) x 10(-9) cm(3) s(-1) (fitted average from several data), a new highly resolved absolute attachment cross section for T(G) = 300 K was determined. Partial cross sections for formation of the anions Cl(-), Cl(2)(-), F(-), ClF(-), and CCl(2)F(-) were measured over the range 0-12 eV, using three different electron beam experiments of medium energy resolution. The dependence of the attachment rate coefficient k(T(e);T(G) = 300 K) on electron temperature T(e) was calculated over the range 50-15 000 K, based on a newly constructed total cross section for anion formation at T(G) = 300 K. R-matrix calculations for Cl(-) production have been carried out for comparison with the experimental data. The R-matrix results are in line with the main experimental observations and predict the dependence of the DEA cross section on the initial vibrational level nu(3)() and on the vibrational temperature. Furthermore, the cross section for vibrational excitation of the nu(3) mode has been computed.


    Energy Technology Data Exchange (ETDEWEB)

    Andrei Tokmakoff, MIT (Conference Chair); Paul Champion, Northeastern University; Edwin J. Heilweil, NIST; Keith A. Nelson, MIT; Larry Ziegler, Boston University


    This document contains the Proceedings from the 14th International Conference on Time-Resolved Vibrational Spectroscopy, which was held in Meredith, NH from May 9-14, 2009. The study of molecular dynamics in chemical reaction and biological processes using time-resolved spectroscopy plays an important role in our understanding of energy conversion, storage, and utilization problems. Fundamental studies of chemical reactivity, molecular rearrangements, and charge transport are broadly supported by the DOE’s Office of Science because of their role in the development of alternative energy sources, the understanding of biological energy conversion processes, the efficient utilization of existing energy resources, and the mitigation of reactive intermediates in radiation chemistry. In addition, time-resolved spectroscopy is central to all five of DOE’s grand challenges for fundamental energy science. The Time-Resolved Vibrational Spectroscopy conference is organized biennially to bring the leaders in this field from around the globe together with young scientists to discuss the most recent scientific and technological advances. The latest technology in ultrafast infrared, Raman, and terahertz spectroscopy and the scientific advances that these methods enable were covered. Particular emphasis was placed on new experimental methods used to probe molecular dynamics in liquids, solids, interfaces, nanostructured materials, and biomolecules.

  20. Time-resolved vibrational spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tokmakoff, Andrei [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Champion, Paul [Northeastern Univ., Boston, MA (United States); Heilweil, Edwin J. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States); Nelson, Keith A. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Ziegler, Larry [Boston Univ., MA (United States)


    This document contains the Proceedings from the 14th International Conference on Time-Resolved Vibrational Spectroscopy, which was held in Meredith, NH from May 9-14, 2009. The study of molecular dynamics in chemical reaction and biological processes using time-resolved spectroscopy plays an important role in our understanding of energy conversion, storage, and utilization problems. Fundamental studies of chemical reactivity, molecular rearrangements, and charge transport are broadly supported by the DOE's Office of Science because of their role in the development of alternative energy sources, the understanding of biological energy conversion processes, the efficient utilization of existing energy resources, and the mitigation of reactive intermediates in radiation chemistry. In addition, time-resolved spectroscopy is central to all fiveof DOE's grand challenges for fundamental energy science. The Time-Resolved Vibrational Spectroscopy conference is organized biennially to bring the leaders in this field from around the globe together with young scientists to discuss the most recent scientific and technological advances. The latest technology in ultrafast infrared, Raman, and terahertz spectroscopy and the scientific advances that these methods enable were covered. Particular emphasis was placed on new experimental methods used to probe molecular dynamics in liquids, solids, interfaces, nanostructured materials, and biomolecules.

  1. Electron attachment to molecules and clusters of atmospheric relevance: oxygen and ozone (United States)

    Matejcik, S.; Kiendler, A.; Cicman, P.; Skalny, J.; Stampfli, P.; Illenberger, E.; Chu, Y.; Stamatovic, A.; Märk, T. D.


    Highly monochromatized electrons are used in a crossed beams experiment to investigate electron attachment to oxygen clusters 0963-0252/6/2/007/img1 at electron energies from approximately zero up to 2 eV. At energies close to zero the attachment cross section for the reaction 0963-0252/6/2/007/img2 varies inversely with the electron energy, indicative of s-wave electron capture to 0963-0252/6/2/007/img1. Peaks in the attachment cross section present at higher energies can be ascribed to vibrational levels of the oxygen anion. The vibrational spacings observed can be quantitatively accounted for. In addition, electron attachment to ozone and mixed oxygen/ozone clusters has been studied in the energy range up to 4 eV. Absolute attachment cross sections for both fragment ions, 0963-0252/6/2/007/img4 and 0963-0252/6/2/007/img5, from ozone could be deduced. Moreover, despite the initially large excess of oxygen molecules in the neutral oxygen/ozone clusters the dominant attachment products are undissociated clusters ions 0963-0252/6/2/007/img6 including the 0963-0252/6/2/007/img7 monomer while oxygen ions 0963-0252/6/2/007/img8 appear with comparatively low intensity.

  2. Mechanical vibration and shock analysis, sinusoidal vibration

    CERN Document Server

    Lalanne, Christian


    Everything engineers need to know about mechanical vibration and one authoritative reference work! This fully updated and revised 3rd edition addresses the entire field of mechanical vibration and shock as one of the most important types of load and stress applied to structures, machines and components in the real world. Examples include everything from the regular and predictable loads applied to turbines, motors or helicopters by the spinning of their constituent parts to the ability of buildings to withstand damage from wind loads or explosions, and the need for cars to m

  3. [Vibration on agricultural tractors]. (United States)

    Peretti, Alessandro; Delvecchio, Simone; Bonomini, Francesco; di Bisceglie, Anita Pasqua; Colosio, Claudio


    In the article, details related to the diffusion of agricultural tractors in Italy are given and considerations about the effects of vibration on operators, the sources of vibration and suggestions to reduce them are presented. The acceleration values observed in Italy amongst 244 tractors and levels of worker exposure are shown by means of histograms. The relevant data variability is discussed.

  4. Picking up good vibrations

    NARCIS (Netherlands)

    Eijk, A.


    The methods that need to be employed to develop the better vibration guidelines to assess the integrity of a reciprocating compressor system are discussed. An R&D project of the European Forum of Reciprocating Compressors (EFRC) has been initiated to develop guidelines for vibrations in reciprocatin

  5. Vibrational Schroedinger Cats (United States)

    Kis, Z.; Janszky, J.; Vinogradov, An. V.; Kobayashi, T.


    The optical Schroedinger cat states are simple realizations of quantum states having nonclassical features. It is shown that vibrational analogues of such states can be realized in an experiment of double pulse excitation of vibrionic transitions. To track the evolution of the vibrational wave packet we derive a non-unitary time evolution operator so that calculations are made in a quasi Heisenberg picture.

  6. Vibration Theory, Vol. 3

    DEFF Research Database (Denmark)

    Nielsen, Søren R. K.

    The present textbook has been written based on previous lecture notes for a course on stochastic vibration theory that is being given on the 9th semester at Aalborg University for M. Sc. students in structural engineering. The present 4th edition of this textbook on linear stochastic vibration...

  7. Vibration Theory, Vol. 3

    DEFF Research Database (Denmark)

    Nielsen, Søren R. K.

    The present textbook has been written based on previous lecture notes for a course on stochastic vibration theory that is being given on the 9th semester at Aalborg University for M. Sc. students in structural engineering. The present 2nd edition of this textbook on linear stochastic vibration th...

  8. Hamiltonian Dynamics of Preferential Attachment

    CERN Document Server

    Zuev, Konstantin; Krioukov, Dmitri


    Prediction and control of network dynamics are grand-challenge problems in network science. The lack of understanding of fundamental laws driving the dynamics of networks is among the reasons why many practical problems of great significance remain unsolved for decades. Here we study the dynamics of networks evolving according to preferential attachment, known to approximate well the large-scale growth dynamics of a variety of real networks. We show that this dynamics is Hamiltonian, thus casting the study of complex networks dynamics to the powerful canonical formalism, in which the time evolution of a dynamical system is described by Hamilton's equations. We derive the explicit form of the Hamiltonian that governs network growth in preferential attachment. This Hamiltonian turns out to be nearly identical to graph energy in the configuration model, which shows that the ensemble of random graphs generated by preferential attachment is nearly identical to the ensemble of random graphs with scale-free degree d...

  9. Vibration control in accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Montag, C.


    In the vast majority of accelerator applications, ground vibration amplitudes are well below tolerable magnet jitter amplitudes. In these cases, it is necessary and sufficient to design a rigid magnet support structure that does not amplify ground vibration. Since accelerator beam lines are typically installed at an elevation of 1-2m above ground level, special care has to be taken in order to avoid designing a support structure that acts like an inverted pendulum with a low resonance frequency, resulting in untolerable lateral vibration amplitudes of the accelerator components when excited by either ambient ground motion or vibration sources within the accelerator itself, such as cooling water pumps or helium flow in superconducting magnets. In cases where ground motion amplitudes already exceed the required jiter tolerances, for instance in future linear colliders, passive vibration damping or active stabilization may be considered.

  10. A novel wireless and temperature-compensated SAW vibration sensor. (United States)

    Wang, Wen; Xue, Xufeng; Huang, Yangqing; Liu, Xinlu


    A novel wireless and passive surface acoustic wave (SAW) based temperature-compensated vibration sensor utilizing a flexible Y-cut quartz cantilever beam with a relatively substantial proof mass and two one-port resonators is developed. One resonator acts as the sensing device adjacent to the clamped end for maximum strain sensitivity, and the other one is used as the reference located on clamped end for temperature compensation for vibration sensor through the differential approach. Vibration directed to the proof mass flex the cantilever, inducing relative changes in the acoustic propagation characteristics of the SAW travelling along the sensing device, and generated output signal varies in frequency as a function of vibration.  A theoretical mode using the Rayleigh method was established to determine the optimal dimensions of the cantilever beam. Coupling of Modes (COM) model was used to extract the optimal design parameters of the SAW devices prior to fabrication. The performance of the developed SAW sensor attached to an antenna towards applied vibration was evaluated wirelessly by using the precise vibration table, programmable incubator chamber, and reader unit.  High vibration sensitivity of ~10.4 kHz/g, good temperature stability, and excellent linearity were observed in the wireless measurements.

  11. A Novel Wireless and Temperature-Compensated SAW Vibration Sensor

    Directory of Open Access Journals (Sweden)

    Wen Wang


    Full Text Available A novel wireless and passive surface acoustic wave (SAW based temperature-compensated vibration sensor utilizing a flexible Y-cut quartz cantilever beam with a relatively substantial proof mass and two one-port resonators is developed. One resonator acts as the sensing device adjacent to the clamped end for maximum strain sensitivity, and the other one is used as the reference located on clamped end for temperature compensation for vibration sensor through the differential approach. Vibration directed to the proof mass flex the cantilever, inducing relative changes in the acoustic propagation characteristics of the SAW travelling along the sensing device, and generated output signal varies in frequency as a function of vibration.  A theoretical mode using the Rayleigh method was established to determine the optimal dimensions of the cantilever beam. Coupling of Modes (COM model was used to extract the optimal design parameters of the SAW devices prior to fabrication. The performance of the developed SAW sensor attached to an antenna towards applied vibration was evaluated wirelessly by using the precise vibration table, programmable incubator chamber, and reader unit.  High vibration sensitivity of ~10.4 kHz/g, good temperature stability, and excellent linearity were observed in the wireless measurements.

  12. Attachment Processes in Eating Disorder and Depression. (United States)

    Cole-Detke, Holland; Kobak, Roger


    Examines the relationship between attachment strategies and symptom reporting among college women (N=61). The Adult Attachment Interview (AAI) was administered and interview transcripts were rated with the Attachment Interview Q-Sort. Findings support the hypothesis that secondary or defensive attachment strategies predispose individuals toward…

  13. Structural Interfaces and Attachments in Biology

    CERN Document Server

    Birman, Victor; Genin, Guy


    Attachment of dissimilar materials in engineering and surgical practice is a perennial challenge. Bimaterial attachment sites are common locations for injury, repeated injury, and mechanical failure. Nature presents several highly effective solutions to the challenge of bimaterial attachment that differ from those found in engineering practice. Structural Interfaces and Attachments in Biology describes the attachment of dissimilar materials from multiple perspectives. The text will simultaneously elucidate natural bimaterial attachments and outline engineering principles underlying successful attachments to the communities of tissue engineers and surgeons. Included an in-depth analysis of the biology of attachments in the body and mechanisms by which robust attachments are formed, a review of current concepts of attaching dissimilar materials in surgical practice and a discussion of bioengineering approaches that are currently being developed. This book also: Provides the first comprehensive treatment of phys...

  14. Spectroscopic investigation of photoinduced charge-transfer processes in FTO/TiO2/N719 photoanodes with and without covalent attachment through silane-based linkers. (United States)

    Pandit, Bill; Luitel, Tulashi; Cummins, Dustin R; Thapa, Arjun K; Druffel, Thad; Zamborini, Frank; Liu, Jinjun


    Understanding electron-transfer (ET) processes in dye-sensitized solar cells (DSSCs) is crucial to improving their device performance. Recently, covalent attachment of dye molecules to mesoporous semiconductor nanoparticle films via molecular linkers has been employed to increase the stability of DSSC photoanodes. The power conversion efficiency (PCE) of these DSSCs, however, is lower than DSSCs with conventional unmodified photoanodes in this study. Ultrafast transient absorption pump-probe spectroscopy (TAPPS) has been used to study the electron injection process from N719 dye molecules to TiO2 nanoparticles (NPs) in DSSC photoanodes with and without the presence of two silane-based linker molecules: 3-aminopropyltriethoxysilane (APTES) and p-aminophenyltrimethoxysilane (APhS). Ultrafast biphasic electron injection kinetics were observed in all three photoanodes using a 530 nm pump wavelength and 860 nm probe wavelength. Both the slow and fast decay components, attributed to electron injection from singlet and triplet excited states, respectively, of the N719 dye to the TiO2 conduction band, are hindered by the molecular linkers. The hindering effect is less significant with the APhS linker than the APTES linker and is more significant for the singlet-state channel than the triplet-state one. Electron injection from the vibrationally excited states is less affected by the linkers. The spectroscopic results are interpreted on the basis of the standard ET theory and can be used to guide selection of molecular linkers for DSSCs with better device performance. Other factors that affect the efficiency and stability of the DSSCs are also discussed. The relatively lower PCE of the covalently attached photoanodes is attributed to the multilayer and aggregation of the dye molecules as well as the linkers.

  15. Bar overdentures utilizing the Locator attachment. (United States)

    Schneider, A L; Kurtzman, G M


    Implant-retained overdentures are a restorative option for both the fully and partially edentulous arches. A new attachment, the Locator, which features a reduced interarch requirement and the advantage of built-in guide planes providing precise insertion, is described. The Locator is an advancement in attachment technology, with an improved design combined from the best features of a ball attachment, an ERA attachment, and a cap attachment.


    Directory of Open Access Journals (Sweden)

    Lindsay Stewart


    Full Text Available This article is the Keynote Address given at the 5th International Integrative Psychotherapy Association Conference in Vichy, France, April 21, 2011. In the article author describes development of secure attachment with the help of the case study.

  17. Adult attachment and psychosocial functioning

    NARCIS (Netherlands)

    Pielage, Suzanne Brenda


    In the trilogy Attachment, Separation and Loss (1969, 1973, 1980), Bowlby theorized that early experiences with caregivers affect the quality of individuals’ later (romantic) relationships and, consequently, their mental health. The current thesis set out to examine the relationships between adult a

  18. Vibration Analysis of a Residential Building

    Directory of Open Access Journals (Sweden)

    Sampaio Regina Augusta


    Full Text Available The aim of this paper is to present the results of a study regarding vibration problems in a 17 storey residential building during pile driving in its vicinity. The structural design of the building was checked according to the Brazilian standards NBR6118 and NBR6123, and using commercial finite element software. An experimental analysis was also carried out using low frequency piezo-accelerometers attached to the building structure. Structure vibrations were recorded under ambient conditions. Four monitoring tests were performed on different days. The objective of the first monitoring test was an experimental modal analysis. To obtain de modal parameters, data was processed in the commercial software ARTEMIS employing two methods: the Stochastic Subspace Identification and the Frequency Domain Decomposition. Human comfort was investigated considering the International Standard ISO 2631. The Portuguese standard, NP2074, was also used as a reference, since it aims to limit the adverse effects of vibrations in structures caused by pile driving in the vicinity of the structure. The carried out experimental tests have shown that, according to ISO2301, the measure vibration levels are above the acceptance limits. However, velocity peaks are below the limits established by NP2074. It was concluded that, although the structure has adequate capacity to resist internal forces according to normative criteria, it has low horizontal stiffness, which could be verified by observing the vibration frequencies and mode shapes obtained with the finite element models, and its similarity with the experimental results. Thus, the analyses indicate the occurrence of discomfort by the residents.

  19. Shedding light on the specificity of school-aged children's attachment narratives. (United States)

    Borelli, Jessica L; Somers, Jennifer A; West, Jessica L; Coffey, John K; Shmueli-Goetz, Yael


    A prominent research tradition within the field of attachment involves analyzing relationship narratives for qualities thought to reveal important information regarding the organization of attachment, and the different ways in which attachment insecurity presents. Researchers increasingly use this method to assess attachment in middle childhood, but further work needs to be conducted with respect to the divergent validity of attachment narratives in this age range. Thus, the current study examined differential associations between children's discursive style and linguistic behavior when completing an attachment interview (Child Attachment Interview [CAI]) and Non-Relational Interview (NRI). In addition, the discriminant validity of attachment narratives was assessed in predicting children's physiological reactivity to a relational challenge. Children (N = 125) completed the NRI and the CAI at Time 1. A subset of the original sample (n = 64) completed another assessment 1.5 years later involving simulated non-relational and relational challenges. While narrative coherence was moderately associated across the two interviews, CAI narrative coherence uniquely predicted reactivity to a relational probe. We discuss implications for understanding children's narrative styles across discourse topics as well as the significance of the results for using attachment interviews in this age range.

  20. An improved fabrication method for carbon nanotube probe

    Institute of Scientific and Technical Information of China (English)

    XU Zong-wei; GUO Li-qiu; DONG Shen; ZHAO Qing-liang


    An improved arc discharge method is developed to fabricate the carbon nanotube probe.In this method,the silicon probe and the carbon nanotube were manipulated under an optical microscope.When the silicon probe and the carbon nanotube were very close,30-60 V dc or ac was applied between them,and the carbon nanotube was divided and attached to the end of the silicon probe.Comparing with the arc discharge method,the new method need not coat the silicon probe with metal in advance,which Can greatly reduce the fabrication difficulty and cost.The fabricated carbon nanotube probe exhibits the good property of hish aspect ratio and can reflect the true topography more accurately than the silicon probe.

  1. Coherent vibrational dynamics

    CERN Document Server

    Lanzani, Guglielmo; De Silvestri, Sandro


    Vibrational spectroscopy is a powerful investigation tool for a wide class of materials covering diverse areas in physics, chemistry and biology. The continuous development in the laser field regarding ultrashort pulse generation has led to the possibility of producing light pulses that can follow vibrational motion coupled to the electronic transitions in molecules and solids in real time. Aimed at researchers and graduate students using vibrational spectroscopy, this book provides both introductory chapters as well as more advanced contents reporting on recent progress. It also provides a good starting point for scientists seeking a sound introduction to ultrafast optics and spectroscopic techniques.

  2. Vibration enhanced quantum transport

    CERN Document Server

    Semião, F L; Milburn, G J


    In this paper, we study the role of a collective vibrational motion in the phenomenon of electronic energy transfer (EET) between chromophores with different electronic transition frequencies. Previous experimental work on EET in conjugated polymer samples has suggested that the common structural framework of the macromolecule introduce correlations in the energy gap fluctuations which cause coherent EET. We present a simple model describing the coupling between the chromophores and a common vibrational mode, and find that vibration can indeed lead to an enhancement in the transport of excitations across the quantum network. Furthermore, in our model phase information is partially retained in the transfer process from a donor to an acceptor, as experimentally demonstrated in the conjugated polymer system. Consequently, this mechanism of vibration enhanced quantum transport might find applications in quantum information transfer of qubit states or entanglement.

  3. NIF Ambient Vibration Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Noble, C.R.; Hoehler, M.S., S.C. Sommer


    LLNL has an ongoing research and development project that includes developing data acquisition systems with remote wireless communication for monitoring the vibrations of large civil engineering structures. In order to establish the capability of performing remote sensing over an extended period of time, the researchers needed to apply this technology to a real structure. The construction of the National Ignition Facility provided an opportunity to test the data acquisition system on a large structure to monitor whether the facility is remaining within the strict ambient vibration guidelines. This document will briefly discuss the NIF ambient vibration requirements and summarize the vibration measurements performed during the Spring and Summer of 1999. In addition, a brief description of the sensors and the data acquisition systems will be provided in Appendix B.

  4. Vibrating wire alignment technique

    CERN Document Server

    Xiao-Long, Wang; lei, Wu; Chun-Hua, Li


    Vibrating wire alignment technique is a kind of method which through measuring the spatial distribution of magnetic field to do the alignment and it can achieve very high alignment accuracy. Vibrating wire alignment technique can be applied for magnet fiducialization and accelerator straight section components alignment, it is a necessary supplement for conventional alignment method. This article will systematically expound the international research achievements of vibrating wire alignment technique, including vibrating wire model analysis, system frequency calculation, wire sag calculation and the relation between wire amplitude and magnetic induction intensity. On the basis of model analysis this article will introduce the alignment method which based on magnetic field measurement and the alignment method which based on amplitude and phase measurement. Finally, some basic questions will be discussed and the solutions will be given.

  5. Nano surface interaction and mo del of vibrating prob e%纳米表面相互作用及振动测头模型∗

    Institute of Scientific and Technical Information of China (English)

    陈丽娟; 陈晓怀; 刘芳芳; 王景凡


    The high precision measurement has been a focus in the field of manufacturing and microelectronics in this year. The micro/nano probe for coordinate measuring machine (CMM) acts as a key characteristic because it can measure the high-aspect-ratio components with high precision. Various micro/nano-CMM probes with different principles and different structures have been developed in the last decade. However, most of these studies focused on the sensing principle and measurement methods. There is little research on the behavior of the surface interaction between the probe tip and the workpiece. And the measurement accuracy and reliability of the current probe, especially those of the low stiffness probe, are limited by interaction forces including capillary force, van der Waals force, electrostatic force and Casimir force. Therefore, it becomes a challenge to reduce the effect of the surface interaction forces for the Micro/nano CMM probe. A new trigger probe based on the vibrating principle is analyzed and an optimal method for the appropriate vibrating parameters is presented in this paper. The structure and principle of the probe are briefly described in the first part. In this system, a tungsten stylus with a tip-ball is fixed to the floating plate, which is supported by four L-shape high-elasticity leaf springs. The fiber Bargg grating (FBG) sensors are used in the probe for micro-CMM due to their superiority in t of small size, high sensitivity, large linear measuring range, immunity to electromagnetic interference, and low cost. One end of FBG is attached to a floating plate, and the other end to a retention plate which is connected with the piezoelectric ceramic actuator (PZT). The probe is driven by the PZT vibrating. Assuming that the driving forces can offset the surface interaction forces, then the probe can be described as a forced vibration model of the spring oscillator. Therefore, the equivalent model of the probe is set up. In the second part, a

  6. Carbon monoxide dissociative attachment and resonant dissociation by electron-impact (United States)

    Laporta, V.; Tennyson, J.; Celiberto, R.


    Low-energy dissociative electron attachment and resonant electron impact dissociation of CO molecule are considered. Ro-vibrationally resolved cross sections and rate coefficients for both the processes are calculated using an ab-initio model based on the low-lying \\text{X}{{}2}\\Pi resonance of CO-. Final results show that the cross sections increases very rapidly as a function of the ro-vibrational level; these cross sections should be useful for understanding kinetic dissociation of CO in strongly non-equilibrium plasmas.

  7. Design, fabrication and testing of two electrohydraulic vibration isolation systems for helicopter environments (United States)

    Allen, R. E.; Calcaterra, P. C.


    Two electrohydraulic vibration isolation systems were designed and fabricated to reduce the vertical vibrations transmitted to the XH-51N research helicopter cabin at the blade passage frequency (18 Hz) and its first harmonic (36 Hz). Hydraulic power and electrical control are provided to two separate servoactuators from a common power supply and control electronics package located behind the pilot's seat. One servoactuator is installed between the cabin and fuselage and replaces an existing passive spring. A second servoactuator is mounted between the existing seat and cabin floor. Both servoactuators incorporate a mechanical failsafe design. The control electronics circuitry provides automatic tracking of the blade passage frequency. Results of laboratory, environmental and ground vibration tests employing an XH-51A stripped down helicopter fuselage show that the active cabin isolator reduces the vertical vibrations transmitted from the fuselage attachment point to the cabin attachment point at 18 and 36 Hz (or as an alternative, 6 Hz) by better than 90 percent.

  8. Proximal Probes Facility (United States)

    Federal Laboratory Consortium — The Proximal Probes Facility consists of laboratories for microscopy, spectroscopy, and probing of nanostructured materials and their functional properties. At the...

  9. Attachable rock bolters for roadheaders

    Energy Technology Data Exchange (ETDEWEB)

    Weibezahn, K. [Wirth Maschinen- und Bohrgeraete-Fabrik GmbH, Erkelenz (Germany); West, M. [Deilmann-Haniel Mining Systems GmbH (Germany)


    Roadheaders are used in mining and tunnelling in medium hard rock formations. The excavated space is made safe either by NATM-technology or a steel support system. The application of a rock bolting system up to now was restricted to formations that can cope with at least some support lag. A new system was developed in close cooperation between WIRTH Maschinen- und Bohrgeraetefabrik GmbH and deilmann-haniel mining systems gmbh that allows to carry out rock bolting with two drill rigs whicht are attached to the cutting boom of the roadheader even in front of the cutter head directly after cutting. Alternatively a robot may be attached to above named system that enables remotely controlled shot-creting close to the face.

  10. Bubble oscillations and motion under vibration

    CERN Document Server

    O'Hern, Tim; Torczynski, John


    Bubbles under vibration can behave in unusual ways, e.g., moving downward against the force of buoyancy. While the bubble downward motion due to the Bjerknes force is well known at acoustic frequencies close to the bubble resonant frequency, these experiments demonstrate that these effects can be observed at relatively low frequencies as well. Experiments were performed in a thin, quasi-two-dimensional rectangular acrylic box partially filled with 20-cSt PDMS silicone oil with overlying ambient air. The apparatus was subjected to sinusoidal axial vibration that produced breakup of the gas-liquid free surface, producing liquid jets into the air, droplets pinching off from these jets, gas cavities in the liquid from impacts of these droplets, and bubble transport below the interface. Vibration conditions for the attached videos are 280 Hz frequency, 15 g acceleration, and 94 micron peak-to-peak displacement. Behaviors shown in the videos include the following. 1. Free surface breakup into jets and droplets, and...

  11. Vibration reduction on automotive shafts using piezoceramics (United States)

    Kunze, Holger; Riedel, Mathias; Schmidt, Knut; Bianchini, Emanuele


    This paper reports an experimental study on active vibration reduction for automotive shafts with the use of piezoelectric material. The work focuses on an axle of an Audi A2. The demand in the automobile sector for higher comfort in the vehicle is of a great importance alongside the requirements of lighter weight and low fuel consumption. These requirements are typically in conflict with each other. One solution is the use of intelligent materials instead of viscoelastic materials and proof mass absorbers. These solutions are quite heavy especially at low frequencies. Active vibration control and piezoelectric devices are advantageous in this application due to their low mass to performance ratio. Our research study explores the use of such piezoelectric devices for an axle. In conjunction with electronics it will reduce vibrations in the first natural bending mode of the axle. Laboratory tests simulated the condition present in the road. At first a stationary set up was used, then a simulated disturbance was input at the attachment points of the shaft. Finally, a test with rotating shaft was performed. Piezoelectric devices (custom QuickPacks from ACX, a Division of Cymer) were used as sensors and as actuators to properly control the axle during the different operating conditions. The power consumption of each actuator pair was less than 20W. The work described here details the test setup, the control strategy, the hardware implementation as well as the test results obtained.

  12. On power flow suppression in straight elastic pipes by use of equally spaced eccentric inertial attachments

    DEFF Research Database (Denmark)

    Sorokin, Sergey; Holst-Jensen, Ole


    of the problem in vibrations of this structure. The power flow analysis in a pipe with and without equally spaced eccentric inertial attachments is performed and the effect of suppression of the energy transmission is demonstrated theoretically. These results are put in the context of predictions from......The paper addresses the power flow suppression in an elastic beam of the tubular cross section (a pipe) at relatively low excitation frequencies by deploying a small number of equally spaced inertial attachments. The methodology of boundary integral equations is used to obtain an exact solution...

  13. Vibrational Study of Melatonin and its Radioprotective Activity towards Hydroxyl Radical (United States)

    Singh, Gurpreet; Kaur, Sarvpreet; Saini, G. S. S.


    Vibrational study of Melatonin (N-acetyl 5-methoxytrypatamin) was done using FTIR and Raman spectroscopy. DFT calculations were employed to the structural analysis of melatonin and to the end products. The theoretical calculations confirmed the different observed vibrational modes. The optimized structure energy calculations of the different end products confirmed the most probable site of the hydroxyl radical attack is the hydrogen attached to nitrogen present in the indole ring.

  14. Adult attachment processes: individual and couple perspectives. (United States)

    Bartholomew, K


    This paper overviews a new approach to understanding the range of difficulties experienced in close attachment relationships in adulthood. Drawing on the work of Bowlby, four prototypic adult attachment patterns are defined in terms of the intersection of two underlying dimensions, the positivity of the person's self-image and the positivity of the person's image of others (Bartholomew, 1990; Bartholomew & Horowitz, 1991). The distinct interpersonal difficulties associated with each attachment pattern are described. Findings are presented indicating that individual differences in attachment have implications for the quality of adults' romantic relationships, and that attachment theory may be helpful in understanding violent spousal relationships. Five current issues in the study of adult attachment are addressed: the stability of attachment patterns, the associations between attachment and general personality factors, the relative merits of categorical and prototype assessments of attachment, the identification of multiple attachments in adulthood, and the specificity of adult attachment patterns. It is suggested that the four-category model of adult attachment is especially sensitive to the range and complexity of attachment-related difficulties experienced in adulthood.

  15. Vibrational control of electron-transfer reactions: a feasibility study for the fast coherent transfer regime. (United States)

    Antoniou, P; Ma, Z; Zhang, P; Beratan, D N; Skourtis, S S


    Molecular vibrations and electron-vibrational interactions are central to the control of biomolecular electron and energy-transfer rates. The vibrational control of molecular electron-transfer reactions by infrared pulses may enable the precise probing of electronic-vibrational interactions and of their roles in determining electron-transfer mechanisms. This type of electron-transfer rate control is advantageous because it does not alter the electronic state of the molecular electron-transfer system or irreversibly change its molecular structure. For bridge-mediated electron-transfer reactions, infrared (vibrational) excitation of the bridge linking the electron donor to the electron acceptor was suggested as being capable of influencing the electron-transfer rate by modulating the bridge-mediated donor-to-acceptor electronic coupling. This kind of electron-transfer experiment has been realized, demonstrating that bridge-mediated electron-transfer rates can be changed by exciting vibrational modes of the bridge. Here, we use simple models and ab initio computations to explore the physical constraints on one's ability to vibrationally perturb electron-transfer rates using infrared excitation. These constraints stem from the nature of molecular vibrational spectra, the strengths of the electron-vibrational coupling, and the interaction between molecular vibrations and infrared radiation. With these constraints in mind, we suggest parameter regimes and molecular architectures that may enhance the vibrational control of electron transfer for fast coherent electron-transfer reactions.

  16. Alkyl CH Stretch Vibrations as a Probe of Conformational Preferences (United States)

    Sibert, Edwin L. Sibert, Iii; Buchanan, Evan G.; Zwier, Timothy S.


    Theoretical IR spectra of 1,2-diphenoxyethane (C_6H_5-O-CH_2-CH_2-O-C_6H_5 DPOE) and 1,2-diphenylethane (C_6H_5-CH_2-CH_2-C_6H_5 DPE) are presented and compared to results of single-conformation spectroscopy of jet cooled molecules. The theoretical transition energies and intensites are obtained from a model based on a local mode Hamiltonian that includes all local cubic stretch-bend couplings that are then projected onto the normal modes. The model parameters are obtained from density functional theory methods. Full dimensional calculations are compared to those of reduced dimensions that include anharmonic CH streches Fermi coupled to scissor modes. Excellent agreement is found. Scale factors of select terms in the reduced dimensional Hamiltonian are determined by fitting the theoretical Hamiltonian to the anti DPE spectrum. Using the same scaling, Hamiltonians for other conformers of the above molecules are generated and used to predict structures by comparing to experimentally determined spectra in the alkyl CH stretch region. The level patterns in the resulting spectra are elucidated in terms of the model parameters. The model results are extended to interpret the spectra of more complicated macrocycles containing multiple -CH_2CH_2- ethano bridges such as the dibenzo-15-crown-5 ether and 2,2,2-paracyclophane.

  17. Emanuel Miller Lecture: Attachment Insecurity, Disinhibited Attachment, and Attachment Disorders--Where Do Research Findings Leave the Concepts? (United States)

    Rutter, Michael; Kreppner, Jana; Sonuga-Barke, Edmund


    Background: Despite the evidence on anomalous attachment patterns, there has been a tendency to interpret most of these as reflecting differences in security/insecurity. Methods: Empirical research findings are reviewed in relation to attachment/insecurity as evident in both infancy and later childhood, disorganised attachment, inhibited…

  18. Attaching Chuck Keys to Machine Tools (United States)

    Richardson, V.


    Chuck keys attached to portable machine tools by retracting lanyards. Lanyard held taut by recoil caddy attached to tool base. Chuck key available for use when needed and safely secured during operation of tool.

  19. Surface Acoustic Wave Vibration Sensors for Measuring Aircraft Flutter (United States)

    Wilson, William C.; Moore, Jason P.; Juarez, Peter D.


    Under NASA's Advanced Air Vehicles Program the Advanced Air Transport Technology (AATT) Project is investigating flutter effects on aeroelastic wings. To support that work a new method for measuring vibrations due to flutter has been developed. The method employs low power Surface Acoustic Wave (SAW) sensors. To demonstrate the ability of the SAW sensor to detect flutter vibrations the sensors were attached to a Carbon fiber-reinforced polymer (CFRP) composite panel which was vibrated at six frequencies from 1Hz to 50Hz. The SAW data was compared to accelerometer data and was found to resemble sine waves and match each other closely. The SAW module design and results from the tests are presented here.

  20. Performance Study of Diagonally Segmented Piezoelectric Vibration Energy Harvester

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Eun [Catholic Univ. of Daegu, Daegu (Korea, Republic of)


    This study proposes a piezoelectric vibration energy harvester composed of two diagonally segmented energy harvesting units. An auxiliary structural unit is attached to the tip of a host structural unit cantilevered to a vibrating base, where the two components have beam axes in opposite directions from each other and matched short-circuit resonant frequencies. Contrary to the usual observations in two resonant frequency-matched structures, the proposed structure shows little eigenfrequency separation and yields a mode sequence change between the first two modes. These lead to maximum power generation around a specific frequency. By using commercial finite element software, it is shown that the magnitude of the output power from the proposed vibration energy harvester can be substantially improved in comparison with those from conventional cantilevered energy harvesters with the same footprint area and magnitude of a tip mass.

  1. Multi-link piezoelectric structure for vibration energy harvesting (United States)

    Aryanpur, Rameen M.; White, Robert D.


    Work in piezoelectric vibration energy harvesting has typically focused on single member cantilevered structures with transverse tip displacement at a known frequency, taking advantage of the optimal coupling characteristics of piezoceramics in the 3-1 bending mode. Multi-member designs could be advantageous in delivering power to a load in environments with random or wide-band vibrations. The design presented in this work consists of two hinged piezoceramic (PZT-5A) beams x-poled for series operation. Each beam measures 31.8mm x 12.7mm x 0.38mm and consists of two layers of nickel-plated piezoceramic adhered to a brass center shim. The hinge device consists of two custom-machined aluminum attachments epoxied to the end of a beam and connected using a 1.59mm diameter alloy steel dowel. A stainless steel torsion spring is placed over the pin and attached to the aluminum body to provide a restoring torque when under rotation. The design is modeled using the piezoelectric constitutive equations to solve for voltage and power for a set of electromechanical boundary conditions. Experimental measurements on the design are achieved by bolting one end of the structure to a vibration shaker and fixing the other to a rigid framework of industrial aluminum framing material. For a given frequency of vibration, power output of the structure can be obtained by measuring voltage drop across a resistive load.

  2. Loneliness and Attachment Patterns in Young Adults. (United States)

    Hecht, Diana Taylor; Baum, Steven K.


    Investigated the relationship between loneliness and patterns of attachment in 47 college students. Results revealed a moderate to strong relationship between feeling lonely and early disrupted attachment, consistent with the notion that underlying attachment disorders may affect psychological development and social behavior. (JAC)

  3. Attachment in rat pups, an experimental approach

    NARCIS (Netherlands)

    Gispen, W.H.; Sigling, H.; Engeland, H. van; Spruijt, B.M.


    John Bowlby's attachment theory states that attachment behavior has been strengthened throughout evolution as a consequence of its adaptive value. We investigated the presence of attachment-like behavior in rat pups, by offering a choice between the home nest and a same aged other nest. Rat pups sho

  4. Cesarean Births and Attachment Behaviors of Fathers. (United States)


    Apgar scores are 7 or greater at both 1 and 5...status, indications for cesarean delivery, anesthesis, and infant’s gestational age, birth weight, and apgar scores . Prior to meeting the father, and attachment score ; highest school grade completed and attachment score ; and age and child care experience of the father and attachment score

  5. Secondary Attachments and Adolescent Self Concept. (United States)

    Adams-Price, Carolyn; Greene, A. L.


    In a study examining attachments to celebrity figures, 79 male and female fifth, eighth, and eleventh graders and college sophomores described themselves and their favorite celebrities. It was found that such attachments are equally important to males and females, and that gender and age affect the nature of the attachment. (DM)

  6. Easy Attachment Of Panels To A Truss (United States)

    Thomson, Mark; Gralewski, Mark


    Conceptual antenna dish, solar collector, or similar structure consists of hexagonal panels supported by truss erected in field. Truss built in increments to maintain access to panel-attachment nodes. Each panel brought toward truss at angle and attached to two nodes. Panel rotated into attachment at third node.

  7. Reactive Attachment Disorder: Recommendations for School Counselors. (United States)

    Hayes, Susanna H.


    Using a case study, explores a unique counseling relationship. Examines how the quality of parent-child attachment and care of a child during the formative preschool years affects interpersonal relationship skills and school adjustment. Discusses reactive attachment disorders, the pervasiveness of attachment disorders, and recommendations for…

  8. Attachment in Middle Childhood: Progress and Prospects (United States)

    Bosmans, Guy; Kerns, Kathryn A.


    Contrary to the substantial amount of research on infant, preschool, adolescent, and adult attachment, middle childhood has long been neglected by the international attachment research community. In the past two decades, however, there has been a steep increase in research focusing on middle childhood attachment. This article provides an overview…

  9. 21 CFR 872.3165 - Precision attachment. (United States)


    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Precision attachment. 872.3165 Section 872.3165...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3165 Precision attachment. (a) Identification. A precision attachment or preformed bar is a device made of austenitic alloys or alloys containing 75...

  10. Probe tip heating assembly (United States)

    Schmitz, Roger William; Oh, Yunje


    A heating assembly configured for use in mechanical testing at a scale of microns or less. The heating assembly includes a probe tip assembly configured for coupling with a transducer of the mechanical testing system. The probe tip assembly includes a probe tip heater system having a heating element, a probe tip coupled with the probe tip heater system, and a heater socket assembly. The heater socket assembly, in one example, includes a yoke and a heater interface that form a socket within the heater socket assembly. The probe tip heater system, coupled with the probe tip, is slidably received and clamped within the socket.

  11. Enhanced ground-based vibration testing for aerodynamic environments (United States)

    Daborn, P. M.; Ind, P. R.; Ewins, D. J.


    Typical methods of replicating aerodynamic environments in the laboratory are generally poor. A structure which flies "freely" in its normal operating environment, excited over its entire external surface by aerodynamic forces and in all directions simultaneously, is then subjected to a vibration test in the laboratory whilst rigidly attached to a high impedance shaker and excited by forces applied through a few attachment points and in one direction only. The two environments could hardly be more different. The majority of vibration testing is carried out at commercial establishments and it is understandable that little has been published which demonstrates the limitations with the status quo. The primary objective of this research is to do just that with a view to identifying significant improvements in vibration testing in light of modern technology. In this paper, case studies are presented which highlight some of the limitations with typical vibration tests showing that they can lead to significant overtests, sometimes by many orders of magnitude, with the level of overtest varying considerably across a wide range of frequencies. This research shows that substantial benefits can be gained by "freely" suspending the structure in the laboratory and exciting it with a relatively small number of electrodynamic shakers using Multi-Input-Multi-Output (MIMO) control technology. The shaker configuration can be designed to excite the modes within the bandwidth utilising the inherent amplification of the resonances to achieve the desired response levels. This free-free MIMO vibration test approach is shown to result in substantial benefits that include extremely good replication of the aerodynamic environment and significant savings in time as all axes are excited simultaneously instead of the sequential X, Y and Z testing required with traditional vibration tests. In addition, substantial cost savings can be achieved by replacing some expensive large shaker systems

  12. On the control of vibrations using synchrophasing (United States)

    Dench, M. R.; Brennan, M. J.; Ferguson, N. S.


    This paper describes the application of a technique, known as synchrophasing, to the control of machinery vibration. It is applicable to machinery installations, in which several synchronous machines, such as those driven by electrical motors, are fitted to an isolated common structure known as a machinery raft. To reduce the vibration transmitted to the host structure to which the machinery raft is attached, the phase of the electrical supply to the motors is adjusted so that the net transmitted force to the host structure is minimised. It is shown that while this is relatively simple for an installation consisting of two machines, it is more complicated for installations in which there are more than two machines, because of the interaction between the forces generated by each machine. The development of a synchrophasing scheme, which has been applied to propeller aircraft, and is known as Propeller Signature Theory (PST) is discussed. It is shown both theoretically and experimentally, that this is an efficient way of controlling the phase of multiple machines. It is also shown that synchrophasing is a worthwhile vibration control technique, which has the potential to suppress vibration transmitted to the host structure by up to 20 dB at certain frequencies. Although the principle of synchronisation has been demonstrated on a one-dimensional structure, it is believed that this captures the key features of the approach. However, it should be realised that the mode-shapes of a machinery raft may be more complex than that of a one-dimensional structure and this may need to be taken into account in a real application.

  13. Vibrational spectroscopy at high external pressures the diamond anvil cell

    CERN Document Server

    Ferraro, John R


    Vibrational Spectroscopy at High External Pressures: The Diamond Anvil Cell presents the effects of high pressure on the vibrational properties of materials as accomplished in a diamond anvil cell (DAC). The DAC serves the dual purpose of generating the pressures and being transparent to infrared radiation, allowing the observation of changes caused by pressure. The optical probes highlighted will deal principally with infrared and Raman scattering, although some observations in the visible region will also be presented. The book begins with a discussion of the effects of pressure and pres

  14. Bound and continuum vibrational states of the bifluoride anion (United States)

    Špirko, V.; Šindelka, M.; Shirsat, R. N.; Leszczynski, J.


    The energies of the bound vibrational states and energy density spectra of the continuum vibrational states of FHF - are calculated, 'exactly' and 'adiabatically', using a new ab initio (CCSD(T)) potential energy surface. Statistical properties of the bound states are probed in terms of the density of states and nearest neighbor level spacing distributions (NNSD). Importantly, the approximate 'adiabatic' densities coincide nearly quantitatively with their 'exact' counterparts. A quantitative fitting of the NNSDs is achieved with a new empirical modification of the Wigner distribution.

  15. Reactive attachment disorder--a theoretical model beyond attachment. (United States)

    Minnis, Helen; Marwick, Helen; Arthur, Julie; McLaughlin, Alexis


    Despite its importance in public health, reactive attachment disorder (RAD) is an under-researched and little used clinical category. Abnormalities of social relatedness have long been documented in children who have been abused, neglected or institutionalised, but there have been more recent efforts to define these behaviours within the psychiatric nosology. There has been an implicit assumption that the central deficit in RAD is in the attachment system, but this has caused controversy and may have blocked research. We propose that RAD is better construed within the framework of intersubjectivity, which has a central role in the development of core brain and social functions and may also have had an important role in the evolution of a key human characteristic-complex social functioning. This broader framework may potentially explain apparently diverse symptoms such as indiscriminate friendliness and negative or unpredictable reunion responses. Finally, we suggest that a change of name may be useful in progressing the field, but accept that this may be difficult until there is better agreement in the clinical and scientific communities about the core features and aetiology of this disorder.

  16. Vibration modeling of structural fuzzy with continuous boundary

    DEFF Research Database (Denmark)

    Friis, Lars; Ohlrich, Mogens


    From experiments it is well known that the vibration response of a main structure with many attached substructures often shows more damping than structural losses in the components can account for. In practice, these substructures, which are not attached in an entirely rigid manner, behave like...... a multitude of different sprung masses each strongly resisting any motion of the main structure (master) at their base antiresonance. The “theory of structural fuzzy” is intended for modeling such high damping. In the present article the theory of fuzzy structures is briefly outlined and a method of modeling...... effect of the fuzzy with spatial memory is demonstrated by numerical simulations of a main beam structure with fuzzy attachments. It is shown that the introduction of spatial memory reduces the damping effect of the fuzzy and in certain cases the damping effect may even be eliminated completely....

  17. Effects of different manual periodontal probes on periodontal measurements (United States)

    Holtfreter, Birte; Alte, Dietrich; Schwahn, Christian; Desvarieux, Moïse; Kocher, Thomas


    Aim To quantify the digit preference effect for three manual periodontal probes and to calculate correction values to enable comparison of studies with equal recording protocols, but different periodontal probes. Material and Methods A prospective in vivo crossover study was conducted with a six-sequence three-period design. Six examiners assessed attachment loss (AL), probing pocket depth (PD) and gingiva height (GH) at four surfaces, full-mouth, in six generally healthy subjects using three manual probes: PCP11 (3-3-3-2 mm increments), PCP2 (2 mm increments), and PCPUNC15 (1 mm increments). Results Distributions of AL, PD and GH differed between probes (p < 0.001). Compared with PCPUNC15, periodontal measurements coinciding with probe markings of PCP11 and PCP2, respectively, were preferentially named by examiners. Digit preference was most pronounced for PD, but less for AL and GH. In multilevel models, PD differed significantly between all three probes (p < 0.05); probe- and examiner-related effects were also observed for AL and GH. Correction values for pairwise combinations of probes were determined. Conclusions We provided empirical evidence and quantified the effect of probe type on periodontal measurements. Differences in probe type should be considered when comparing periodontal data within and between epidemiological studies and appropriate corrections, provided here, should be applied. PMID:22924328

  18. Vibrations and waves

    CERN Document Server

    Kaliski, S


    This book gives a comprehensive overview of wave phenomena in different media with interacting mechanical, electromagnetic and other fields. Equations describing wave propagation in linear and non-linear elastic media are followed by equations of rheological models, models with internal rotational degrees of freedom and non-local interactions. Equations for coupled fields: thermal, elastic, electromagnetic, piezoelectric, and magneto-spin with adequate boundary conditions are also included. Together with its companion volume Vibrations and Waves. Part A: Vibrations this work provides a wealth

  19. Vibrational spectroscopy of resveratrol (United States)

    Billes, Ferenc; Mohammed-Ziegler, Ildikó; Mikosch, Hans; Tyihák, Ernő


    In this article the authors deal with the experimental and theoretical interpretation of the vibrational spectra of trans-resveratrol (3,5,4'-trihydroxy- trans-stilbene) of diverse beneficial biological activity. Infrared and Raman spectra of the compound were recorded; density functional calculations were carried out resulting in the optimized geometry and several properties of the molecule. Based on the calculated force constants, a normal coordinate analysis yielded the character of the vibrational modes and the assignment of the measured spectral bands.

  20. Vibrations and Stability

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel

    dynamical phenomena that can be encountered in engineering and scientific practice. It progresses steadily from linear vibration theory over various levels of nonlinearity to bifurcation analysis, global dynamics and chaotic vibrations. It trains the student to analyze simple models, recognize nonlinear...... phenomena and work with advanced tools such as perturbation analysis and bifurcation analysis. Explaining theory in terms of relevant examples from real systems, this book is user-friendly and meets the increasing interest in non-linear dynamics in mechanical/structural engineering and applied mathematics...

  1. Damping of acoustic vibrations in gold nanoparticles (United States)

    Pelton, Matthew; Sader, John E.; Burgin, Julien; Liu, Mingzhao; Guyot-Sionnest, Philippe; Gosztola, David


    Studies of acoustic vibrations in nanometre-scale particles can provide fundamental insights into the mechanical properties of materials because it is possible to precisely characterize and control the crystallinity and geometry of such nanostructures. Metal nanoparticles are of particular interest because they allow the use of ultrafast laser pulses to generate and probe high-frequency acoustic vibrations, which have the potential to be used in a variety of sensing applications. So far, the decay of these vibrations has been dominated by dephasing due to variations in nanoparticle size. Such inhomogeneities can be eliminated by performing measurements on single nanoparticles deposited on a substrate, but unknown interactions between the nanoparticles and the substrate make it difficult to interpret the results of such experiments. Here, we show that the effects of inhomogeneous damping can be reduced by using bipyramidal gold nanoparticles with highly uniform sizes. The inferred homogeneous damping is due to the combination of damping intrinsic to the nanoparticles and the surrounding solvent; the latter is quantitatively described by a parameter-free model.

  2. Vibration Propagation in Spider Webs (United States)

    Hatton, Ross; Otto, Andrew; Elias, Damian

    Due to their poor eyesight, spiders rely on web vibrations for situational awareness. Web-borne vibrations are used to determine the location of prey, predators, and potential mates. The influence of web geometry and composition on web vibrations is important for understanding spider's behavior and ecology. Past studies on web vibrations have experimentally measured the frequency response of web geometries by removing threads from existing webs. The full influence of web structure and tension distribution on vibration transmission; however, has not been addressed in prior work. We have constructed physical artificial webs and computer models to better understand the effect of web structure on vibration transmission. These models provide insight into the propagation of vibrations through the webs, the frequency response of the bare web, and the influence of the spider's mass and stiffness on the vibration transmission patterns. Funded by NSF-1504428.

  3. Fault diagnosis of the rolling bearing with optical fiber Bragg grating vibration sensor (United States)

    Wei, Peng; Dai, Zejing; Zheng, Leilei; Li, Ming


    Fault diagnosis of the rolling bearing means a lot for property and life safety. In this paper the Fiber Bragg Grating (FBG) vibration sensor and resonance demodulation technology are used in the fault diagnosis of the rolling bearing. Traditionally, the vibration signals are measured by the resistance strain gauge, accelerometer, etc. But those traditional electronic sensors are usually influenced by the industry electromagnetic noise. But the FBG vibration sensor is totally different. It has a lot of advantages such as small volume, light weight, easy connection and so on. And the high industry electromagnetic noise means nothing to the FBG sensors. In this paper, we use the FBG vibration and temperature sensors to measure the fast strain and temperature signal of the rolling bearing. In order to extract the fault signals from strong background noise, the resonant demodulation technology is used to analyze and process the vibration signals collected by the FBG sensors. In order to verify the reliability of the FBG vibration sensor and resonance demodulation technology applied in the fault diagnosis of the rolling bearing, several experiments are done. Five FBG vibration sensors are attached on the different parts of the rolling bearing to verify its function and its influence on the fault diagnosis of the rolling bearing. The results of the experiments show that the FBG vibration sensor method could be used in fault diagnosis of the rolling bearing. The repetitive experiments show the reliability of the FBG vibration sensors method.

  4. Development of vibrating insoles

    NARCIS (Netherlands)

    Hijmans, J.M.; Geertzen, J.H.B.; Schokker, B.; Postema, K.


    The objective of this study was to describe the development of vibrating insoles. Insoles, providing a subsensory mechanical noise signal to the plantar side of the feet, may improve balance in healthy young and older people and in patients with stroke or diabetic neuropathy. This study describes th

  5. Vibration Sensitive Keystroke Analysis

    NARCIS (Netherlands)

    Lopatka, M.; Peetz, M.-H.; van Erp, M.; Stehouwer, H.; van Zaanen, M.


    We present a novel method for performing non-invasive biometric analysis on habitual keystroke patterns using a vibration-based feature space. With the increasing availability of 3-D accelerometer chips in laptop computers, conventional methods using time vectors may be augmented using a distinct fe

  6. Vibration characteristics of ultrasonic complex vibration for hole machining (United States)

    Asami, Takuya; Miura, Hikaru


    Complex vibration sources that use diagonal slits as a longitudinal-torsional vibration converter have been applied to ultrasonic motors, ultrasonic rock drilling, and ultrasonic welding. However, there are few examples of the application of these sources to ultrasonic machining in combination with an abrasive. Accordingly, a new method has been developed for machining of holes in brittle materials by using the ultrasonic longitudinal and torsional vibration of a hollow-type stepped horn with a diagonal slit vibration converter. In this paper, we compared vibration of a uniform rod and a hollow-type stepped horn, both with diagonal slits, when the conditions of the diagonal slits are constant.

  7. Mobile Game Probes

    DEFF Research Database (Denmark)

    Borup Lynggaard, Aviaja


    This paper will examine how probes can be useful for game designers in the preliminary phases of a design process. The work is based upon a case study concerning pervasive mobile phone games where Mobile Game Probes have emerged from the project. The new probes are aimed towards a specific target...... group and the goal is to specify the probes so they will cover the most relevant areas for our project. The Mobile Game Probes generated many interesting results and new issues occurred, since the probes came to be dynamic and favorable for the process in new ways....

  8. A subcutaneous channeling probe for implanting long leads (United States)

    Lund, G. F.; Simmonds, R. C.; Williams, B. A.


    The channeling probe described in the present paper was designed to overcome surgical problems of the type that were encountered when a multichannel radio transmitter had to be implanted in a cow. The probe was made of a flexible but sufficiently stiff 9.5-mm-diam nylon rod, consisting of 46-cm sections for convenience in sterilization and surgical handling. Stainless steel sleaves reinforced the threaded connecting joints. At one end, arrowhead-shaped channeling heads could be attached to produce wide channels for large sensors. The other end was tapered for narrow channels. Postoperative problems were not encountered in the use of this probe in cows, sheep, and dogs.

  9. The effects of vibration-reducing gloves on finger vibration. (United States)

    Welcome, Daniel E; Dong, Ren G; Xu, Xueyan S; Warren, Christopher; McDowell, Thomas W


    Vibration-reducing (VR) gloves have been used to reduce the hand-transmitted vibration exposures from machines and powered hand tools but their effectiveness remains unclear, especially for finger protection. The objectives of this study are to determine whether VR gloves can attenuate the vibration transmitted to the fingers and to enhance the understanding of the mechanisms of how these gloves work. Seven adult male subjects participated in the experiment. The fixed factors evaluated include hand force (four levels), glove condition (gel-filled, air bladder, no gloves), and location of the finger vibration measurement. A 3-D laser vibrometer was used to measure the vibrations on the fingers with and without wearing a glove on a 3-D hand-arm vibration test system. This study finds that the effect of VR gloves on the finger vibration depends on not only the gloves but also their influence on the distribution of the finger contact stiffness and the grip effort. As a result, the gloves increase the vibration in the fingertip area but marginally reduce the vibration in the proximal area at some frequencies below 100 Hz. On average, the gloves reduce the vibration of the entire fingers by less than 3% at frequencies below 80 Hz but increase at frequencies from 80 to 400 Hz. At higher frequencies, the gel-filled glove is more effective at reducing the finger vibration than the air bladder-filled glove. The implications of these findings are discussed.

  10. Active vibration control of structures undergoing bending vibrations (United States)

    Pla, Frederic G. (Inventor); Rajiyah, Harindra (Inventor)


    An active vibration control subassembly for a structure (such as a jet engine duct or a washing machine panel) undergoing bending vibrations caused by a source (such as the clothes agitator of the washing machine) independent of the subassembly. A piezoceramic actuator plate is vibratable by an applied electric AC signal. The plate is connected to the structure such that vibrations in the plate induced by the AC signal cause canceling bending vibrations in the structure and such that the plate is compressively pre-stressed along the structure when the structure is free of any bending vibrations. The compressive prestressing increases the amplitude of the canceling bending vibrations before the critical tensile stress level of the plate is reached. Preferably, a positive electric DC bias is also applied to the plate in its poling direction.

  11. 吸振器底座对减振效果的影响%Study on Influence of Vibration Absorber' s Base on Its Vibration Attenuation Effect

    Institute of Scientific and Technical Information of China (English)



    In reality, all vibration absorbers have bases. When the vibration absorber is fixed to a flexible base, the base will affect its vibration attenuation effect. Aiming at this problem, simulation researches are carried out with the power flow method in this paper. A mathematical model of the system composed of the vibration absorber with a base and coupled with an ends-fixed beam is established. With this model, the vibration attenuation effects of the vibration absorbers fixed at different positions of the beam are simulated, and the influence of the base size on the vibration attenuation effect is analyzed. On the basis, the vibration attenuation effect with double vibration absorbers attached is compared with that with a single vibration absorber attached. The results show that the vibration attenuation effect of the vibration absorber can be improved effectively by optimizing its base and installation condition. This work provides guidance for the engineering application of the vibration absorbers.%实际使用的吸振器都具有一定尺寸的安装底座.当吸振器安装于柔性主系统时,底座将影响吸振器的减振效果.针对此问题,利用功率流方法进行仿真研究.建立有底座吸振器和两端固支梁主系统耦合的数学模型.利用该模型对吸振器安装在梁上三个不同位置的情况进行仿真研究,并分析底座尺寸的影响,在此基础上比较两个吸振器和单个吸振器的减振效果.研究结果表明,通过优化吸振器的底座和安装方式能够有效地改善吸振器的减振性能.这为吸振器的工程应用提供一定的参考.


    Directory of Open Access Journals (Sweden)

    K. U. Pantsialeyeu


    Full Text Available The contact potential difference probes distinguished by great variety and produced mostly in the laboratory for specific experimental applications. As a rule, they consist of commercially available instrumentation, and have a number of disadvantages: large dimensions, complexity and high cost, small sensitivity, operating speed, noiseproof, etc. The purpose of this paper is to describe the basic approaches to design of the small dimension, complete contact potential difference probes, providing high sensitivity, operating speed, and noise immunity. In this paper the contact potential difference probe, which is a electrometer with dynamic capacitor plate at about 0.1–5 mm2 . These probes are could be used in scanning systems, such as a Scanning Kelvin Probe, as well as for controlling system of manufacturing processes, e.g. under friction. The design of such contact potential difference probes conducted using modern electronic components, unique circuitry and design solutions described in detail at paper. The electromechanical modulator applied for mechanical vibrations of the reference sample. To provide a high amplitude and phase stability the upgraded generator with Wien bridge was used instead traditional oscillation sensor. The preamplifier made on the base of modern operational amplifiers with femtoampere current input. The power of the preamplifier designed with «floating ground». It allows keeping the relation constant potential to the probe components when changing over a wide range the compensation voltage. The phase detector-integrator based on the electronic antiphase switches with the modulation frequency of the contact potential difference and the integrator. Fullwave phase detection would greatly increase the sensitivity of the probe. In addition, the application of the phase detection allows suppressing noise and crosstalk at frequencies different from the modulation frequency. The preamplifier and the reference sample

  13. Phase-sensitive imaging of tissue acoustic vibrations using spectrally encoded interferometry. (United States)

    Ilgayev, Ovadia; Yelin, Dvir


    Acoustic vibrations in tissue are often difficult to image, requiring high-speed scanning, high sensitivity and nanometer-scale axial resolution. Here we use spectrally encoded interferometry to measure the vibration pattern of two-dimensional surfaces, including the skin of a volunteer, at nanometric resolution, without the need for rapid lateral scanning and with no prior knowledge of the driving acoustic waveform. Our results demonstrate the feasibility of this technique for measuring tissue biomechanics using simple and compact imaging probes.

  14. Pattern Matching of Harmonic Vibrations in Nonlinearly Generated Acoustic Modes in Bovine Bone Samples (United States)

    Alippi, A.; Biagioni, A.; Germano, M.; Passeri, D.


    Local probing of nonlinear generation of harmonic vibrations has been done on bone plate samples and the evaluation of the nonlinear term is derived from a limited number of cases of bovine thigh bones, that shows that a low level of nonlinearity is present in bone structures. This is consistent with the assumption that in low level nonlinear samples the distribution of harmonic vibrations matches the corresponding power distribution of the fundamental mode.

  15. Attachment theory: A review of research

    Directory of Open Access Journals (Sweden)

    Polovina Nada


    Full Text Available Research of attachment is numerous and versatile. They differ according to problems addressed, methodology applied (longitudinal studies, studies with horizontal designs, different instruments used, different methods of data analysis, and characteristics of samples involved (concerning age socio/economic status, family ecology. The research is commonly relied on the core assumptions of the theory itself, and the shared characteristic is orientation to explore complex phenomena of human experience and functioning. From the vast variety of research only those who most directly test the basic assumptions of the attachment theory are focused and addressed in the paper: representation of patterns of attachment in the childhood and adulthood, stability and change of attachment security from infancy to early adulthood, transgenerational transmission of attachment characteristics, the place and the role of attachment behavioral system in the personality development. The aim of the paper is to highlight the basic research and theory issues and directions, and illustrate them with concrete research date.

  16. Wear simulation effects on overdenture stud attachments. (United States)

    Rutkunas, Vygandas; Mizutani, Hiroshi; Takahashi, Hidekazu; Iwasaki, Naohiko


    The aim of this study was to evaluate wear effects on overdenture resilient attachments. Six commercially available attachments were investigated: ERA orange and white (EO and EW), Locator pink, white and blue (LRP, LRW and LRB) and OP anchor (OP). Five specimens were used for wear simulation while other two specimens served as controls. Fifteen thousands insertion-removal cycles were simulated. Dimensional changes and surface characteristics were evaluated using light microscopy and SEM, respectively. Sudden decrease of retentive force was characteristic for EO and EW attachments. Retentive force of Locator attachments fluctuated throughout the wear simulation period. Dimensional changes and surface wear was more expressed on plastic cores than on plastic rings of attachment males. Based on SEM analysis, some of the specimens obtained smoother surface after wear simulation. Mechanism of retention loss of resilient overdenture attachments can be only partially explained by dimensional changes and surface alterations.

  17. Association Between Insecure Attachment and ADHD

    DEFF Research Database (Denmark)

    Storebo, Ole Jakob; Darling Rasmussen, Pernille; Simonsen, Erik


    Objective: Psychological theories have postulated an association between insecure attachment and ADHD. The objective of this study is to investigate possible association between insecure attachment and ADHD in children and adults. Method: Review of literature was performed using the Psyc......INFO, Medline, and EMBASE databases. Results: Twenty-nine studies were included in the review. Overall, the studies showed that parental attachment problems and environmental mediating factors were significantly associated with childhood ADHD. Adults with ADHD had a much higher incidence of insecure attachment...... styles than reported in the general population. Conclusion: There seems to be a clear association between ADHD and insecure attachment. It is likely that early intervention in the form of parent training and pharmacological treatment may prevent development of attachment problems. But such studies have...

  18. Histologic evaluation of an Nd:YAG laser-assisted new attachment procedure in humans. (United States)

    Yukna, Raymond A; Carr, Ronald L; Evans, Gerald H


    This report presents histologic results in humans following a laser-assisted new attachment procedure (LANAP) for the treatment of periodontal pockets. Six pairs of single-rooted teeth with moderate to advanced chronic periodontitis associated with subgingival calculus deposits were treated. A bur notch was placed within the pocket at the clinically and radiographically measured apical extent of calculus. All teeth were scaled and root planed with ultrasonic and hand scalers. One of each pair of teeth received treatment of the inner pocket wall with a free-running pulsed neodymium:yttrium-aluminum-garnet (Nd:YAG) laser to remove the pocket epithelium, and the test pockets were lased a second time to seal the pocket. After 3 months, all treated teeth were removed en bloc for histologic processing. LANAP-treated teeth exhibited greater probing depth reductions and clinical probing attachment level gains than the control teeth. All LANAP-treated specimens showed new cementum and new connective tissue attachment in and occasionally coronal to the notch, whereas five of the six control teeth had a long junctional epithelium with no evidence of new attachment or regeneration. There was no evidence of any adverse histologic changes around the LANAP specimens. These cases support the concept that LANAP can be associated with cementum-mediated new connective tissue attachment and apparent periodontal regeneration of diseased root surfaces in humans.

  19. Animal Communications Through Seismic Vibrations

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Peggy (University of Tulsa)


    Substrate vibration has been important to animals as a channel of communication for millions of years, but our literature on vibration in this context of biologically relevant information is only decades old. The jaw mechanism of the earliest land vertebrates allowed them to perceive substrate vibrations as their heads lay on the ground long before airborne sounds could be heard. Although the exact mechanism of vibration production and the precise nature of the wave produced are not always understood, recent development of affordable instrumentation to detect and measure vibrations has allowed researchers to answer increasingly sophisticated questions about how animals send and receive vibration signals. We now know that vibration provides information used in predator defense, prey detection, recruitment to food, mate choice, intrasexual competition, and maternal/brood social interactions in a variety of insect orders, spiders, crabs, scorpions, chameleons, frogs, golden moles, mole rats, kangaroos rats, wallabies, elephants and bison.

  20. Improved Active Vibration Isolation Systems

    Institute of Scientific and Technical Information of China (English)


    The control force, feedback gain, and actuator stroke of several active vibration isolation systems were analyzed based on a single-layer active vibration isolation system. The analysis shows that the feedback gain and actuator stroke cannot be selected independently and the active isolation system design must make a compromise between the feedback gain and actuator stroke. The performance of active isolation systems can be improved by the joint vibration reduction using an active vibration isolation system with an adaptive dynamic vibration absorber. The results show that the joint vibration reduction method can successfully avoid the compromise between the feedback gain and actuator stroke. The control force and the object vibration amplitude are also greatly reduced.

  1. Experimental Study on External Low Frequency Vibration Influence on SPM

    Institute of Scientific and Technical Information of China (English)

    CHEN Jinping; GUO Tong; HU Xiaodong; HU Xiaotang


    The influence of external Iow frequency (0-100 Hz) vibration on the tip-sample interaction in SPM is the main concern of this paper. A concept, vibration rejection ratio (VRR) proposed by Thompson et al, was investigated theoretically and experimentally. A concise theoretical background was introduced, a vibration stimulating and measuring system for SPM was built up, and an experimental research of the influence on SPM VRR was carried out with different SPM probes, samples, tip pre-loads and open/close loops of tip-sample interaction. It was proved both in theory and experiment that SPM VRR had correlations with the spring constant, the air damping constant, the effective mass of the cantilever, the contact spring constant and the contact damping constant between tip and sample. SPM's vibration rejecting ability can be improved by longer cantilever probe, softer sample surface, greater tip pre-load, and close-loop control for tip-sample interaction. More attention should be paid to a proper combination of the above parameters.

  2. Maladie des vibrations (United States)

    Shen, Shixin (Cindy); House, Ronald A.


    Résumé Objectif Permettre aux médecins de famille de comprendre l’épidémiologie, la pathogenèse, les symptômes, le diagnostic et la prise en charge de la maladie des vibrations, une maladie professionnelle importante et courante au Canada. Sources d’information Une recherche a été effectuée sur MEDLINE afin de relever les recherches et comptes rendus portant sur la maladie des vibrations. Une recherche a été effectuée sur Google dans le but d’obtenir la littérature grise qui convient au contexte canadien. D’autres références ont été tirées des articles relevés. Message principal La maladie des vibrations est une maladie professionnelle répandue touchant les travailleurs de diverses industries qui utilisent des outils vibrants. La maladie est cependant sous-diagnostiquée au Canada. Elle compte 3 éléments : vasculaire, sous la forme d’un phénomène de Raynaud secondaire; neurosensoriel; et musculosquelettique. Aux stades les plus avancés, la maladie des vibrations entraîne une invalidité importante et une piètre qualité de vie. Son diagnostic exige une anamnèse minutieuse, en particulier des antécédents professionnels, un examen physique, des analyses de laboratoire afin d’éliminer les autres diagnostics, et la recommandation en médecine du travail aux fins d’investigations plus poussées. La prise en charge consiste à réduire l’exposition aux vibrations, éviter les températures froides, abandonner le tabac et administrer des médicaments. Conclusion Pour assurer un diagnostic rapide de la maladie des vibrations et améliorer le pronostic et la qualité de vie, les médecins de famille devraient connaître cette maladie professionnelle courante, et pouvoir obtenir les détails pertinents durant l’anamnèse, recommander les patients aux cliniques de médecine du travail et débuter les demandes d’indemnisation de manière appropriée. PMID:28292812

  3. Properties of Ultrasound Probes


    Rusina, M.


    This work deals with the measurement properties of ultrasound probes. Ultrasound probes and their parameters significantly affect the quality of the final image. In this work there are described the possibility of measuring the spatial resolution, sensitivity of the probe and measuring the length of the dead zone. Ultrasound phantom ATS Multi Purpose Phantom Type 539 was used for measurements.

  4. Theoretical Analysis of Vibration Frequency of Graphene Sheets Used as Nanomechanical Mass Sensor

    Directory of Open Access Journals (Sweden)

    Toshiaki Natsuki


    Full Text Available Nanoelectromechanical resonator sensors based on graphene sheets (GS show ultrahigh sensitivity to vibration. However, many factors such as the layer number and dimension of the GSs will affect the sensor characteristics. In this study, an analytical model is proposed to investigate the vibration behavior of double-layered graphene sheets (DLGSs with attached nanoparticles. Based on nonlocal continuum mechanics, the influences of the layer number, dimensions of the GSs, and of the mass and position of nanoparticles attached to the GSs on the vibration response of GS resonators are discussed in detail. The results indicate that nanomasses can easily be detected by GS resonators, which can be used as a highly sensitive nanomechanical element in sensor systems. A logarithmically linear relationship exists between the frequency shift and the attached mass when the total mass attached to GS is less than about 1.0 zg. Accordingly, it is convenient to use a linear calibration for the calculation and determination of attached nanomasses. The simulation approach and the parametric investigation are useful tools for the design of graphene-based nanomass sensors and devices.

  5. Control Application of Piezoelectric Materials to Aeroelastic Self-Excited Vibrations

    Directory of Open Access Journals (Sweden)

    Mohammad Amin Rashidifar


    Full Text Available A method for application of piezoelectric materials to aeroelasticity of turbomachinery blades is presented. The governing differential equations of an overhung beam are established. The induced voltage in attached piezoelectric sensors due to the strain of the beam is calculated. In aeroelastic self-excited vibrations, the aerodynamic generalized force of a specified mode can be described as a linear function of the generalized coordinate and its derivatives. This simplifies the closed loop system designed for vibration control of the corresponding structure. On the other hand, there is an industrial interest in measurement of displacement, velocity, acceleration, or a contribution of them for machinery condition monitoring. Considering this criterion in quadratic optimal control systems, a special style of performance index is configured. Utilizing the current relations in an aeroelastic case with proper attachment of piezoelectric elements can provide higher margin of instability and lead to lower vibration magnitude.

  6. Ultrathin lensed fiber-optic probe for optical coherence tomography. (United States)

    Qiu, Y; Wang, Y; Belfield, K D; Liu, X


    We investigated and validated a novel method to develop ultrathin lensed fiber-optic (LFO) probes for optical coherence tomography (OCT) imaging. We made the LFO probe by attaching a segment of no core fiber (NCF) to the distal end of a single mode fiber (SMF) and generating a curved surface at the tip of the NCF using the electric arc of a fusion splicer. The novel fabrication approach enabled us to control the length of the NCF and the radius of the fiber lens independently. By strategically choosing these two parameters, the LFO probe could achieve a broad range of working distance and depth of focus for different OCT applications. A probe with 125μm diameter and lateral resolution up to 10μm was demonstrated. The low-cost, disposable and robust LFO probe is expected to have great potential for interstitial OCT imaging.

  7. All-optical photoacoustic imaging system using fiber ultrasound probe and hollow optical fiber bundle. (United States)

    Miida, Yusuke; Matsuura, Yuji


    An all-optical 3D photoacoustic imaging probe that consists of an optical fiber probe for ultrasound detection and a bundle of hollow optical fibers for excitation of photoacoustic waves was developed. The fiber probe for ultrasound is based on a single-mode optical fiber with a thin polymer film attached to the output end surface that works as a Fabry Perot etalon. The input end of the hollow fiber bundle is aligned so that each fiber in the bundle is sequentially excited. A thin and flexible probe can be obtained because the probe system does not have a scanning mechanism at the distal end.

  8. Attachment theory: Old and new approach

    Directory of Open Access Journals (Sweden)

    Polovina Nada


    Full Text Available The article is an attempt to present holistically the key concepts of attachment theory rediscovered for its potentials. The presented concepts include: narrow definition of attachment, behavioral control system of attachment, attachment working model and patterns of attachment. The concepts are presented in the context of child attachment theory and adult attachment theory, in addition to description of the development of attachment. Concepts, as well as developmental processes are presented from the stand point of pioneers in this field (John Bowlby and Mary Ainsworth as well as from the standpoint of their successors (Everett Waters and Malcolm West. Compacted ness of the theory, possibilities for operationalization of its key concepts and its application to empirical studies of complex psychological issues that have never been scientifically explored, makes it a very prospective theory in view of possible integration of existing research findings and initiating new research and new practices in psychotherapy, social work and work in schools. The goal of this integral presentation of attachment theory is to highlight its benefits and possibilities for understanding and research complex field of human's psychosocial functioning.

  9. Sine-Bar Attachment For Machine Tools (United States)

    Mann, Franklin D.


    Sine-bar attachment for collets, spindles, and chucks helps machinists set up quickly for precise angular cuts that require greater precision than provided by graduations of machine tools. Machinist uses attachment to index head, carriage of milling machine or lathe relative to table or turning axis of tool. Attachment accurate to 1 minute or arc depending on length of sine bar and precision of gauge blocks in setup. Attachment installs quickly and easily on almost any type of lathe or mill. Requires no special clamps or fixtures, and eliminates many trial-and-error measurements. More stable than improvised setups and not jarred out of position readily.

  10. Overdenture locator attachments for atrophic mandible. (United States)

    Mahajan, Neerja; Thakkur, Rahul K


    Implant-supported overdentures provide a good opportunity for dentists to improve oral health and quality-of-life of patients. Atrophic mandible poses a significant challenge to successful oral rehabilitation with dental implants. In this article, the fabrication of lower overdenture by two narrow platform implants is described with dual retentive, resilient, self-locating locator attachment system. The locator attachment system has the lowest profile in comparison with the ball and bar attachments and is versatile up to 40° of divergence between two implants. By using locators as attachments, we can meet functional, economic and social expectation of patients with ease and satisfaction.

  11. Overdenture locator attachments for atrophic mandible

    Directory of Open Access Journals (Sweden)

    Neerja Mahajan


    Full Text Available Implant-supported overdentures provide a good opportunity for dentists to improve oral health and quality-of-life of patients. Atrophic mandible poses a significant challenge to successful oral rehabilitation with dental implants. In this article, the fabrication of lower overdenture by two narrow platform implants is described with dual retentive, resilient, self-locating locator attachment system. The locator attachment system has the lowest profile in comparison with the ball and bar attachments and is versatile up to 40΀ of divergence between two implants. By using locators as attachments, we can meet functional, economic and social expectation of patients with ease and satisfaction.

  12. Temperament and attachment: one construct or two? (United States)

    Mangelsdorf, S C; Frosch, C A


    In this chapter we described the constructs of temperament and attachment and have discussed similarities and differences between the two. We addressed the issue of whether temperament contributes to overall attachment security or to the specific type of attachment that children display. We conclude that although temperament may influence the type of secure and insecure attachment relationship children form with their parent, temperament alone will not determine if a child is classified as securely or insecurely attached. We presented evidence suggesting that certain dimensions of temperament, specifically negative emotionality, may be associated with infants' behavior during the Strange Situation, such as proneness-to-distress during separations. However, we noted that these temperament dimensions do not predict overall security of attachment. It is likely that although no single temperament characteristic, such as proneness-to-distress, in and of itself determines overall attachment security, it is possible that a constellation of temperament characteristics may be more strongly related to attachment security. The examination of constellations of temperament characteristics may be particularly useful for furthering our understanding of individual differences within attachment classifications. Such an approach may elucidate the reasons why infants are classified into one subgroup of secure, insecure-avoidant, or insecure-resistant attachment versus another subgroup. Furthermore, we suggest that the collection of findings regarding temperament and attachment not only underscores the importance of a transactional approach to early social-emotional development, but emphasizes that temperament and attachment can make unique and interactive contributions to children's social-emotional functioning. That is, the goodness-of-fit between infant and parent characteristics may best predict security of attachment. Although child characteristics clearly contribute to the

  13. the Analysis of Coupled Lateral Torsional Vibrations

    Directory of Open Access Journals (Sweden)

    Tomasz Szolc


    Full Text Available In the paper, dynamic investigations of the rotor shaft systems are performed by means of the discrete-continuous mechanical models. In these models the rotor shaft segments are represented by the rotating cylindrical flexurally and torsionally deformable continuous viscoelastic elements. These elements are mutually connected according to the structure of the real system in the form of a stepped shaft which is suspended on concentrated inertial viscoelastic supports of linear or non-linear characteristics. At appropriate shaft crosssections, by means of massless membranes, there are attached rigid rings representing rotors, disks, gears, flywheels and others. The proposed model enables us to investigate coupled linear or non-linear lateral torsional Vibrations of the rotating systems in steady-state and transient operating conditions. As demonstrative examples, for the steam turbo-compressor under coupled lateral torsional vibrations, the transient response due to a blade falling out from the turbine rotor as well as the steady-state response in the form of parametric resonance caused by residual unbalances are presented.

  14. Nonlinear characteristics of an autoparametric vibration system (United States)

    Yan, Zhimiao; Taha, Haithem E.; Tan, Ting


    The nonlinear characteristics of an autoparametric vibration system are investigated. This system consists of a base structure and a cantilever beam with a tip mass. The dynamic equations for the system are derived using the extended Hamilton's principle. The method of multiple scales (MMS) is used to determine an approximate analytical solution of the nonlinear governing equations and, hence, analyze the stability and bifurcation of the system. Compared with the numerical simulation, the first-order MMS is not sufficient. A Lagrangian-based approach is proposed to perform a second-order analysis, which is applicable to a large class of nonlinear systems. The effects of the amplitude and frequency of the external force, damping and frequency of the attached cantilever beam, and the tip mass on the nonlinear responses of the autoparametric vibration system are determined. The results show that this system exhibits many interesting nonlinear phenomena including saturation, jumps, hysteresis and different kinds of bifurcations, such as saddle-node, supercritical pitchfork and subcritical pitchfork bifurcations. Power spectra, phase portraits and Poincare maps are employed to analyze the unstable behavior and the associated Hopf bifurcation and chaos. Depending on the application of such a system, its dynamical behaviors could be exploited or avoided.

  15. Vibration energy harvesting for unmanned aerial vehicles (United States)

    Anton, Steven R.; Inman, Daniel J.


    Unmanned aerial vehicles (UAVs) are a critical component of many military operations. Over the last few decades, the evolution of UAVs has given rise to increasingly smaller aircraft. Along with the development of smaller UAVs, termed mini UAVs, has come issues involving the endurance of the aircraft. Endurance in mini UAVs is problematic because of the limited size of the fuel systems that can be incorporated into the aircraft. A large portion of the total mass of many electric powered mini UAVs, for example, is the rechargeable battery power source. Energy harvesting is an attractive technology for mini UAVs because it offers the potential to increase their endurance without adding significant mass or the need to increase the size of the fuel system. This paper investigates the possibility of harvesting vibration and solar energy in a mini UAV. Experimentation has been carried out on a remote controlled (RC) glider aircraft with a 1.8 m wing span. This aircraft was chosen to replicate the current electric mini UAVs used by the military today. The RC glider was modified to include two piezoelectric patches placed at the roots of the wings and a cantilevered piezoelectric beam installed in the fuselage to harvest energy from wing vibrations and rigid body motions of the aircraft, as well as two thin film photovoltaic panels attached to the top of the wings to harvest energy from sunlight. Flight testing has been performed and the power output of the piezoelectric and photovoltaic devices has been examined.

  16. Detection of protease and protease activity using a single nanoscrescent SERS probe (United States)

    Liu, Gang L.; Ellman, Jonathan A.; Lee, Luke P.; Chen, Fanqing Frank


    This invention pertains to the in vitro detection of proteases using a single peptide-conjugate nanocrescent surface enhanced Raman scattering (SERS) probes with at least nanomolar sensitivity. The probe enables detection of proteolytic activity in extremely small volume and at low concentration. In certain embodiments the probes comprise an indicator for the detection of an active protease, where the indicator comprises a nanocrescent attached to a peptide, where said peptide comprises a recognition site for the protease and a Raman tag attached to the peptide.

  17. Hydroelastic Vibrations of Ships

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher; Folsø, Rasmus


    A formula for the necessary hull girder bending stiffness required to avoid serious springing vibrations is derived. The expression takes into account the zero crossing period of the waves, the ship speed and main dimensions. For whipping vibrations the probability of exceedance for the combined...... wave- and whipping induced bending moment is derived under the assumption that the maximum peak value in a whipping sequence occurs simultaneously with a peak in sagging wave-induced bending moment, but that the magnitudes of these two peaks are statistically independent. The expression can be written...... as the usual Rayleigh distribution for the wave response multiplied by a factor independent of the significant wave height. Finally, the springing and whipping predictions are compared with model test results....

  18. Development of Fluorescent Protein Probes Specific for Parallel DNA and RNA G-Quadruplexes. (United States)

    Dang, Dung Thanh; Phan, Anh Tuân


    We have developed fluorescent protein probes specific for parallel G-quadruplexes by attaching cyan fluorescent protein to the G-quadruplex-binding motif of the RNA helicase RHAU. Fluorescent probes containing RHAU peptide fragments of different lengths were constructed, and their binding to G-quadruplexes was characterized. The selective recognition and discrimination of G-quadruplex topologies by the fluorescent protein probes was easily detected by the naked eye or by conventional gel imaging.

  19. Random vibration movements of liquid nanosized Pb inclusions in Al

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, E.; Andersen, J.S.; Levinsen, M.; Steenstrup, S.; Prokofjev, S.; Zhilin, V.; Dahmen, U.; Radetic, T.; Turner, J.H


    Transmission electron microscopy has been used to study the behavior of liquid nanosized Pb inclusions in Al ribbons made by rapid solidification. In situ heating experiments carried out in the temperature range from around 375 to 450 deg. C have shown that liquid inclusions with sizes from around 10-50 nm, that are trapped on dislocations, perform random vibrations around their positions of attachment with vibration periods of some fractions of seconds. The amplitudes of the vibrations in directions perpendicular to the dislocations are a few nanometers, while the motion in directions parallel to the dislocations can be more than an order of magnitude larger. Under conditions where two or more inclusions, attached to a dislocation line, display one-dimensional random motion the inclusions are rarely seen to coalesce. Movement of the inclusions has been monitored by video and shorter sequences have been digitized and analyzed frame-by-frame. The analysis shows that the step lengths have Gaussian distributions indicative of random walks. Fractal analysis of the paths shows that the fractal dimension is close to two which agrees well with the observations that the inclusions carry out linear random walks in a confined space.

  20. Vibration Induced Microfluidic Atomization (United States)

    Yeo, Leslie; Qi, Aisha; Friend, James


    We demonstrate rapid generation of micron aerosol droplets in a microfluidic device in which a fluid drop is exposed to surface vibration as it sits atop a piezoelectric substrate. Little, however, is understood about the processes by which these droplets form due to the complex hydrodynamic processes that occur across widely varying length and time scales. Through experiments, scaling theory and numerical modelling, we elucidate the interfacial destabilization mechanisms that lead to droplet formation. Droplets form due to the axisymmetric break-up of cylindrical liquid jets ejected as a consequence of interfacial destabilization. Their 10 μm size correlates with the jet radius and the instability wavelength, both determined from a viscous-capillary dominant force balance and confirmed through a numerical solution. With the exception of drops that spread into thin films with thicknesses on the order of the boundary layer dimension, the free surface is always observed to vibrate at the capillary-viscous resonance frequency despite the surface vibration frequency being several orders larger. This is contrary to common assumptions used in deriving subharmonic models resulting in a Mathieu equation, which has commonly led to spurious predictions in the droplet size.

  1. Vibrational stability of graphene

    Directory of Open Access Journals (Sweden)

    Yangfan Hu


    Full Text Available The mechanical stability of graphene as temperature rises is analyzed based on three different self-consistent phonon (SCP models. Compared with three-dimensional (3-D materials, the critical temperature Ti at which instability occurs for graphene is much closer to its melting temperature Tm obtained from Monte Carlo simulation (Ti ≃ 2Tm, K. V. Zakharchenko, A. Fasolino, J. H. Los, and M. I. Katsnelson, J. Phys. Condens. Matter 23, 202202. This suggests that thermal vibration plays a significant role in melting of graphene while melting for 3-D materials is often dominated by topologic defects. This peculiar property of graphene derives from its high structural anisotropy, which is characterized by the vibrational anisotropic coefficient (VAC, defined upon its Lindermann ratios in different directions. For any carbon based material with a graphene-like structure, the VAC value must be smaller than 5.4 to maintain its stability. It is also found that the high VAC value of graphene is responsible for its negative thermal expansion coefficient at low temperature range. We believe that the VAC can be regarded as a new criterion concerning the vibrational stability of any low-dimensional (low-D materials.

  2. Pickin’ up good vibrations

    CERN Multimedia

    Katarina Anthony


    In preparation for the civil engineering work on the HL-LHC, vibration measurements were carried out at the LHC’s Point 1 last month. These measurements will help evaluate how civil engineering work could impact the beam, and will provide crucial details about the site’s geological make-up before construction begins.   A seismic truck at Point 1 generated wave-like vibrations measured by EN/MME. From carrying out R&D to produce state-of-the-art magnets to developing innovative, robust materials capable of withstanding beam impact, the HL-LHC is a multi-faceted project involving many groups and teams across CERN’s departments. It was in this framework that the project management mandated CERN's Mechanical and Materials Engineering (EN/MME) group to measure the propagation of vibrations around Point 1. Their question: can civil engineering work for the HL-LHC – the bulk of which is scheduled for LS2 – begin while the LHC is running? Alth...

  3. Contact resonances of U-shaped atomic force microscope probes

    Energy Technology Data Exchange (ETDEWEB)

    Rezaei, E.; Turner, J. A., E-mail: [Mechanical and Materials Engineering, University of Nebraska-Lincoln, W342 Nebraska Hall, Lincoln, Nebraska 68588 (United States)


    Recent approaches used to characterize the elastic or viscoelastic properties of materials with nanoscale resolution have focused on the contact resonances of atomic force microscope (CR-AFM) probes. The experiments for these CR-AFM methods involve measurement of several contact resonances from which the resonant frequency and peak width are found. The contact resonance values are then compared with the noncontact values in order for the sample properties to be evaluated. The data analysis requires vibration models associated with the probe during contact in order for the beam response to be deconvolved from the measured spectra. To date, the majority of CR-AFM research has used rectangular probes that have a relatively simple vibration response. Recently, U-shaped AFM probes have created much interest because they allow local sample heating. However, the vibration response of these probes is much more complex such that CR-AFM is still in its infancy. In this article, a simplified analytical model of U-shaped probes is evaluated for contact resonance applications relative to a more complex finite element (FE) computational model. The tip-sample contact is modeled using three orthogonal Kelvin-Voigt elements such that the resonant frequency and peak width of each mode are functions of the contact conditions. For the purely elastic case, the frequency results of the simple model are within 8% of the FE model for the lowest six modes over a wide range of contact stiffness values. Results for the viscoelastic contact problem for which the quality factor of the lowest six modes is compared show agreement to within 13%. These results suggest that this simple model can be used effectively to evaluate CR-AFM experimental results during AFM scanning such that quantitative mapping of viscoelastic properties may be possible using U-shaped probes.

  4. Electron attachment to the interhalogens ClF, ICl, and IBr (United States)

    Miller, T. M.; Wiens, J. P.; Sawyer, J. C.; Shuman, N. S.; Viggiano, A. A.; Khamesian, M.; Kokoouline, V.; Fabrikant, I. I.


    Electron attachment rate coefficients have been measured for the interhalogens ClF, ICl, and IBr over the range 300-900 K using a flowing-afterglow Langmuir-probe apparatus. The ClF case was also studied theoretically. ClF was found to attach electrons somewhat inefficiently with a rate coefficient of 7.5x 10-9 cm3/s at 300 K, doubling by 700 K. Even so, attachment to ClF is more efficient than seen earlier for F2 and Cl2, which brings up the interesting distinction that attachment to F2 and Cl2 is known to have p-wave threshold behavior, while in ClF the inversion symmetry is broken, allowing an s-wave component. The increase in the rate coefficient for attachment to ClF with temperature was found to be less pronounced than with F2 and Cl2. Ab initio potential energy curves were calculated for ClF and ClF-, and R-matrix theory was used to obtain the resonance widths and energies for the ground state curve crossing, which takes place near the equilibrium internuclear separation in ClF. A local complex potential model was used to calculate attachment cross sections and thermal rate coefficients. There is reasonable agreement between theory and experiment within the estimated 25% uncertainties in the data. Cl- is the only product ion from thermal electron attachment to ClF. Attachment to ICl is even less efficient by almost an order of magnitude than to ClF, namely, 9.5x 10-10 cm3/s at 300 K. Attachment to IBr is small enough that we place an upper limit of < 10-10 cm3/s at 300 K. Supported by AFOSR, DOE, and NSF.

  5. Insect attachment on crystalline bioinspired wax surfaces formed by alkanes of varying chain lengths

    Directory of Open Access Journals (Sweden)

    Elena Gorb


    Full Text Available The impeding effect of plant surfaces covered with three-dimensional wax on attachment and locomotion of insects has been shown previously in numerous experimental studies. The aim of this study was to examine the effect of different parameters of crystalline wax coverage on insect attachment. We performed traction experiments with the beetle Coccinella septempunctata and pull-off force measurements with artificial adhesive systems (tacky polydimethylsiloxane semi-spheres on bioinspired wax surfaces formed by four alkanes of varying chain lengths (C36H74, C40H82, C44H90, and C50H102. All these highly hydrophobic coatings were composed of crystals having similar morphologies but differing in size and distribution/density, and exhibited different surface roughness. The crystal size (length and thickness decreased with an increase of the chain length of the alkanes that formed these surfaces, whereas the density of the wax coverage, as well as the surface roughness, showed an opposite relationship. Traction tests demonstrated a significant, up to 30 fold, reduction of insect attachment forces on the wax surfaces when compared with the reference glass sample. Attachment of the beetles to the wax substrates probably relied solely on the performance of adhesive pads. We found no influence of the wax coatings on the subsequent attachment ability of beetles. The obtained data are explained by the reduction of the real contact between the setal tips of the insect adhesive pads and the wax surfaces due to the micro- and nanoscopic roughness introduced by wax crystals. Experiments with polydimethylsiloxane semi-spheres showed much higher forces on wax samples when compared to insect attachment forces measured on these surfaces. We explain these results by the differences in material properties between polydimethylsiloxane probes and tenent setae of C. septempunctata beetles. Among wax surfaces, force experiments showed stronger insect attachment and higher

  6. Detection of dust grains vibrations with a laser heterodyne receiver of scattered light

    Energy Technology Data Exchange (ETDEWEB)

    Serozhkin, Yuriy [V. Lashkaryov Institute of Semiconductor Physics, 41, Nauky Prospect, Kyiv 03028 (Ukraine)], E-mail:; Kollyukh, Olexiy; Venger, Yevgen [V. Lashkaryov Institute of Semiconductor Physics, 41, Nauky Prospect, Kyiv 03028 (Ukraine)


    We present the results of measurement of grains vibrations under external action in gas and liquid with a laser heterodyne receiver of scattered radiation. For investigation of dynamic characteristics of particles we made the laser heterodyne receiver with sensitivity about 2x10{sup -17} W/Hz and source of probing with radiation power 1 mW. In our pilot experiments, measurement of vibration amplitude of nanoparticles in gas (cigarette smoke) and microparticles in fluid (toothpaste in water) was made. We measured values of vibration amplitudes about 20-30 nm.

  7. Coexistence in preferential attachment networks

    CERN Document Server

    Antunović, Tonći; Racz, Miklos Z


    Competition in markets is ubiquitous: cell-phone providers, computer manufacturers, and sport gear brands all vie for customers. Though several coexisting competitors are often observed in empirical data, many current theoretical models of competition on small-world networks predict a single winner taking over the majority of the network. We introduce a new model of product adoption that focuses on word-of-mouth recommendations to provide an explanation for this coexistence of competitors. The key property of our model is that customer choices evolve simultaneously with the network of customers. When a new node joins the network, it chooses neighbors according to preferential attachment, and then chooses its type based on the number of initial neighbors of each type. This can model a new cell-phone user choosing a cell-phone provider, a new student choosing a laptop, or a new athletic team member choosing a gear provider. We provide a detailed analysis of the new model; in particular, we determine the possibl...

  8. Biliprotein maturation: the chromophore attachment. (United States)

    Scheer, H; Zhao, K-H


    Biliproteins are a widespread group of brilliantly coloured photoreceptors characterized by linear tetrapyrrolic chromophores, bilins, which are covalently bound to the apoproteins via relatively stable thioether bonds. Covalent binding stabilizes the chromoproteins and is mandatory for phycobilisome assembly; and, it is also important in biliprotein applications such as fluorescence labelling. Covalent binding has, on the other hand, also considerably hindered biliprotein research because autocatalytic chromophore additions are rare, and information on enzymatic addition by lyases was limited to a single example, an EF-type lyase attaching phycocyanobilin to cysteine-alpha84 of C-phycocyanin. The discovery of new activities for the latter lyases, and of new types of lyases, have reinvigorated research activities in the subject. So far, work has mainly concentrated on cyanobacterial phycobiliproteins. Methodological advances in the process, however, as well as the finding of often large numbers of homologues, opens new possibilities for research on the subsequent assembly/disassembly of the phycobilisome in cyanobacteria and red algae, on the assembly and organization of the cryptophyte light-harvesting system, on applications in basic research such as protein folding, and on the use of phycobiliproteins for labelling.

  9. Measuring Patients’ Attachment Avoidance in Psychotherapy: Development of the Attachment Avoidance in Therapy Scale (AATS

    Directory of Open Access Journals (Sweden)

    András Láng


    Full Text Available A new scale measuring patient-therapist attachment avoidance was developed. Attachment Avoidance in Therapy Scale is a new measure based on the Bartholomew model of adult attachment (Bartholomew & Horowitz, 1991 and the Experience in Close Relationships Scale (Brennan, Clark, & Shaver, 1998 to measure patients’ attachment avoidance towards therapists. With 112 patient-therapist dyads participating in the study, validation of a preliminary scale – measuring both attachment anxiety and attachment avoidance in therapy – took place using therapists’ evaluations of patients’ relational behavior and patients’ self-reports about their attitude toward psychotherapy. Analysis of the data revealed six underlying scales. Results showed all six scales to be reliable. Validation of scales measuring attachment anxiety failed. The importance of Attachment Avoidance in Therapy Scale and its subscales is discussed.

  10. Novel laser contact probe for periodontal treatment (United States)

    Watanabe, Hisashi; Kataoka, Kenzo; Ishikawa, Isao


    Application of the erbium: YAG laser to periodontal treatment has been attempted and preferable results have been reported for calculus removal, vaporization of granulation tissue, periodontal pocket sterilization and so on. However, it has been difficult to reach and treat some conditions involving complex root morphology and furcated rots with conventional probes. The new broom probe was designed and tested to overcome these obstacles. The probe was made of 20 super-fine optical fibers bound into a broom shape. The experiments were carried out to evaluate the destructive power of a single fiber and to examine the morphology of tissue destruction and the accessibility to a bifurcated root of a human tooth using the broom probe. The Er:YAG laser prototype was used. A flat specimen plate was made by cutting the root of a cow tooth and then attached to an electrically operated table and irradiated under various conditions. The specimens were examined with both an optical and scanning electron microscope. The irradiated surfaces were also examined with a roughness meter. An irradiation applied with a single fiber with an energy level of 1 to 1.5 mJ at its tip results in a destruction depth of 3 to 24 micrometers . The optimum conditions for the fibers of this probe was 1.0 mJ at 10 pps and a scanning speed of 100 mm/min. No part of the tooth surface remained un-irradiated after using the broom probe to cover the surface 5 times parallel to the tooth axis and then five times at a 30 degree angle to the previous irradiation at a power of 20 mJ at 10 pps. Also curved and irregular surface were destroyed to a maximum depth of 19 micrometers . In conclusion, these results suggest that the broom probe would be applicable for periodontal laser treatments even if the tooth surface has a complex and irregular shape.

  11. Production of vibrationally excited hydrogen molecules by atom recombination on Cu and W materials. (United States)

    Markelj, Sabina; Čadež, Iztok


    We have measured vibrational population of H(2) and D(2) molecules produced by atom (H or D) recombination on tungsten and copper material. The vibrational spectroscopy, based on the properties of dissociative electron attachment to hydrogen molecule, was used. The vibrationally excited molecules were produced by atom recombination in a cell where the studied sample is exposed to hydrogen atoms, from hot tungsten filament. Vibrational populations were obtained for the studied materials, which can be well described by the Boltzmann distribution, with specific vibrational temperatures for each material. The experimentally obtained vibrational populations for copper approximately agree with the theoretical predictions, whereas the experimentally obtained vibrational temperature for tungsten is higher and thus showing a considerable overpopulation of highly excited vibrational states than predicted. We propose that the origin of this higher excitation is related to the existence of high hydrogen surface coverage on tungsten, where hydrogen is occupying binding sites with different desorption energies. In order to obtain an insight into the recombination mechanism with more than one binding site per unit cell, a Monte Carlo simulation was performed, where it was assumed that the main production of molecules proceeds through the hot-atom recombination with an adsorbed atom. The results show that the recombination proceeds mainly through the weak binding sites, once they are occupied.


    Institute of Scientific and Technical Information of China (English)

    Siegfried Ripperger; Konrad Hein


    The vibration method represents a practical method for the measurement of adhesion forces and adhesion force distributions. This method causes sinusoidally altemating stresses and yields detachment and contact forces between particles and substrate of the same order of magnitude. Alternating contact forces of the vibration method can cause an adhesion force intensification through flattening of asperities. The measuring principle of the vibration method and the analysis of experimental results are described in the article. Normal adhesion forces (pull-off forces) are measured using the vibration method and the colloidal probe technique. The results of both methods show good agreement for small particle sizes. The influence of the detachment force direction is shown by comparing tangential and normal adhesion forces measured using particle reentrainment in a turbulent air flow and the vibration method, respectively. The surface roughness of the substrate and the relative humidity are shown to significantly influence the measured adhesion forces. For the calculation of the adhesion forces, an approach by Rabinovich was combined with approximations of plastic micro asperity flattening. The Rabinovich approach accounts for roughness effects on the van der Waals force by incorporating the rms roughness of the interacting surfaces. rms-values of the particles and substrates were measured with atomic force microscopy at different scanning areas.

  13. Vibrational Förster transfer to hydrated protons. (United States)

    Timmer, R L A; Tielrooij, K J; Bakker, H J


    We have studied the influence of excess protons on the vibrational energy relaxation of the O-H and O-D stretching modes in water using femtosecond pump-probe spectroscopy. Without excess protons, we observe exponential decays with time constants of 1.7 and 4.3 ps for the bulk and anion bound O-D stretch vibrations. The addition of protons introduces a new energy relaxation pathway, which leads to an increasingly nonexponential decay of the O-D stretch vibration. This new pathway is attributed to a distance-dependent long range dipole-dipole (Forster) interaction between the O-D stretching vibration and modes associated with dissolved protons. The high efficiency of hydrated protons as receptors of vibrational energy follows from the very large absorption cross section and broad bandwidth of protons in water. For a proton concentration of 1M we find that Forster energy transfer occurs over an average distance of 4.5 A, which corresponds to a separation of about two water molecules.

  14. Anxiety, cortisol, and attachment predict plasma oxytocin

    NARCIS (Netherlands)

    Tops, Mattie; Van Peer, Jacobien M.; Korf, Jakob; Wijers, Albertus A.; Tucker, Don M.


    Oxytocin and attachment seem to interact in suppressing subjective anxiety and physiological stress responses. In this study we investigated the relationships between individual differences in trait attachment scores, state and trait anxiety, plasma cortisol, and plasma oxytocin levels in healthy pr

  15. Adolescent Self-Esteem, Attachment and Loneliness (United States)

    Dhal, Anubha; Bhatia, Sangeeta; Sharma, Vidhi; Gupta, Priyanka


    Objectives: To assess self-esteem, loneliness and attachment styles among adolescents and examine their association with each other and with age and gender. Method: Adolescents (55 males and 55 females) from a public school in Delhi, aged 10-13 years were administered Coopersmith Self-Esteem Inventory (School Form), Attachment Scale and UCLA…

  16. An Attachment Perspective on Anger among Adolescents (United States)

    Konishi, Chiaki; Hymel, Shelley


    Extending John Bowlby's hypothesis that dysfunctional anger is a predictable outcome of insecure attachments to parents, this study investigated the relationship between current parent-adolescent attachment and both the experience and expression of anger. Participants included 776 students (379 boys and 397 girls) in grades 8-12. As predicted…

  17. Separation-individuation theory and attachment theory. (United States)

    Blum, Harold P


    Separation-individuation and attachment theories are compared and assessed in the context of psychoanalytic developmental theory and their application to clinical work. As introduced by Margaret Mahler and John Bowlby, respectively, both theories were initially regarded as diverging from traditional views. Separation-individuation theory, though it has had to be corrected in important respects, and attachment theory, despite certain limitations, have nonetheless enriched psychoanalytic thought. Without attachment an infant would die, and with severely insecure attachment is at greater risk for serious disorders. Development depends on continued attachment to a responsive and responsible caregiver. Continued attachment to the primary object was regarded by Mahler as as intrinsic to the process of separation-individuation. Attachment theory does not account for the essential development of separateness, and separation-individuation is important for the promotion of autonomy, independence, and identity. Salient historical and theoretical issues are addressed, including the renewed interest in attachment theory and the related decline of interest in separation-individuation theory.

  18. Attachment of Salmonella spp. to pork meat

    DEFF Research Database (Denmark)

    Hansen, Trine; Riber, Leise; Löfström, Charlotta


    Five strains of Salmonella, one wildtype and four knock-out mutants (the prg, flhDC, yhjH and fliC genes) were investigated based on their probability to attach and subsequently detach from a surface of pork fillet. The attachment followed by detachment was measured and modelled for two different...

  19. Attachment, emotion regulation and adult crying

    NARCIS (Netherlands)

    Maas, J.; Laan, A.; Vingerhoets, A.J.J.M.


    Attachment serves to facilitate the contact with and proximity to the primary caregiver, in that way contributing to a safe exploration of the environment. However, due to inconsistencies in the reaction of the caregiver or her/his absence, insecure attachment styles may develop. This chapter summar

  20. Forgiveness and health: The role of attachment

    NARCIS (Netherlands)

    Lawler-Row, K.A.; Hyatt-Edwards, L.; Wünsch, K.L.; Karremans, J.C.T.M.


    Attachment was examined for its association to forgiveness and health. Young adults were interviewed about a time of conflict with a parent; during rest and interview periods, readings of blood pressure and heart rate were taken. Participants completed surveys of forgiveness, attachment, relationshi

  1. Parent-Child Attachment and Emotion Regulation (United States)

    Brumariu, Laura E.


    Given the centrality of both parent-child attachment and emotion regulation in children's development and adjustment, it is important to evaluate the relations between these constructs. This article discusses conceptual and empirical links between attachment and emotion regulation in middle childhood, highlights progress and challenges in the…

  2. Attachment Disorder, Basic Trust and Educational Psychology (United States)

    King, Michael G.; Newnham, Karyn


    The label Attachment Disorder (AD) is used as either a description of a child's presentation, or as a diagnostic category. It is unclear whether this label is intended to be identical with the DSM-IV Reactive Attachment Disorder (RAD) diagnostic category, or if it is a separate diagnosis based on Randolph's Questionnaire and the premises…

  3. Attachment and Socioemotional Problems in Middle Childhood (United States)

    Moss, Ellen; Lecompte, Vanessa


    In this article, we will evaluate the evidence concerning links between attachment and behavior problems in the middle childhood period. We will first provide a general introduction to the question of attachment and maladaptation in the middle childhood period, and then examine the recent empirical evidence with respect to both externalizing and…

  4. An Attachment Perspective on Anger among Adolescents (United States)

    Konishi, Chiaki; Hymel, Shelley


    Extending John Bowlby's hypothesis that dysfunctional anger is a predictable outcome of insecure attachments to parents, this study investigated the relationship between current parent-adolescent attachment and both the experience and expression of anger. Participants included 776 students (379 boys and 397 girls) in grades 8-12. As predicted by…

  5. An Attachment Model of University Connectedness (United States)

    Wilson, Steffen; Gore, Jonathan


    Students with high levels of connectedness to the university have been found to be more likely to complete their college degree than are students with low levels of university connectedness. This study examined the role of parental and peer attachment as distal predictors of school connectedness. As predicted, it was found that attachment style to…

  6. Adult Attachment as a Risk Factor for Intimate Partner Violence : The "Mispairing" of Partners' Attachment Styles (United States)

    Doumas, Diana M.; Pearson, Christine L.; Elgin, Jenna E.; McKinley, Lisa L.


    This study examined the relationship between intimate partner violence and adult attachment in a sample of 70 couples. The attachment style of each partner and the interaction of the partners' attachment styles were examined as predictors of intimate partner violence. Additional analyses were conducted to examine violence reciprocity and to…

  7. Attachment and children's biased attentional processing: evidence for the exclusion of attachment-related information.

    Directory of Open Access Journals (Sweden)

    Eva Vandevivere

    Full Text Available Research in both infants and adults demonstrated that attachment expectations are associated with the attentional processing of attachment-related information. However, this research suffered from methodological issues and has not been validated across ages. Employing a more ecologically valid paradigm to measure attentional processes by virtue of eye tracking, the current study tested the defensive exclusion hypothesis in late childhood. According to this hypothesis, insecurely attached children are assumed to defensively exclude attachment-related information. We hypothesized that securely attached children process attachment- related neutral and emotional information in a more open manner compared to insecurely attached children. Sixty-two children (59.7% girls, 8-12 years completed two different tasks, while eye movements were recorded: task one presented an array of neutral faces including mother and unfamiliar women and task two presented the same with happy and angry faces. Results indicated that more securely attached children looked longer at mother's face regardless of the emotional expression. Also, they tend to have more maintained attention to mother's neutral face. Furthermore, more attachment avoidance was related to a reduced total viewing time of mother's neutral, happy, and angry face. Attachment anxiety was not consistently related to the processing of mother's face. Findings support the theoretical assumption that securely attached children have an open manner of processing all attachment-related information.

  8. Adult Attachment, Culturally Adjusted Attachment, and Interpersonal Difficulties of Taiwanese Adults (United States)

    Wang, Chia-Chih DC; Scalise, Dominick A.


    This study examines the applicability of Western adult attachment perspectives to interpersonal difficulties experienced by individuals with indigenous Chinese cultural backgrounds. A total of 275 Taiwanese university students completed self-report surveys of adult attachment, ideal attachment, and interpersonal problems. Culturally adjusted…

  9. Attachment to groups: theory and measurement. (United States)

    Smith, E R; Murphy, J; Coats, S


    Aspects of people's identification with groups may be understood by borrowing theoretical ideas and measurement strategies from research on attachment in close relationships. People have mental models of the self as a group member and of groups as sources of identity and esteem. These models affect thoughts, emotions, and behaviors related to group membership. Three studies show that two dimensions of attachment to groups, attachment anxiety and avoidance, can be assessed with good reliability, validity, and over-time stability. These factors are distinct from relationship attachment and from other measures of group identification. Group attachment predicts several important outcomes, including emotions concerning the group, time and activities shared with a group, social support, collective self-esteem, and ways of resolving conflict. This conceptualization provides new insights into the nature of people's psychological ties to groups.

  10. Security of attachment and preschool friendships. (United States)

    Park, K A; Waters, E


    Attachment theory proposes that the quality of the mother-child tie predicts the quality of a child's other close relationships. The purpose of this study was to test whether security of attachment to mother is related to the quality of a preschooler's best friendships. 33 4-year-old and their best friends participated (mean age = 46 months). Attachment Q-set data were collected to score security of mother-child attachment. Security data were used to classify the friend pairs as secure-secure or secure-insecure. Best friend dyads were observed for a 1-hour free-play session. Each pair's behavior was described with the Dyadic Relationships Q-set, a measure designed to describe the behavior of a pair of children. Secure-secure pairs were more harmonious, less controlling, more responsive, and happier than secure-insecure pairs. The results are related to previous work on attachment and social competence.

  11. The Antimicrobial Activity of Porphyrin Attached Polymers (United States)

    Thompson, Lesley


    We are interested in testing the antimicrobial activity of a porphyrin that is attached to a polymer. The porphyrin (5-(4-carboxyphenyl)-10,15,20-tris-(4-pryridyl)) was synthesized from methyl 4-formyl benzoate, 4-pyridinecarboxaldehyde, and pyrrole and attached to a copolymer of polystyrene/poly(vinyl benzyl chloride), which was synthesized by free radical polymerization. The antimicrobial activity of the polymer-attached porphyrin was then determined for gram-negative E. Coli grown to 0.80 OD. In this procedure, glass slides were coated with polymer-attached porphyrin via dip-coating, and the E. Coli bacteria were plated in Luria Broth media. The plates were subsequently exposed to light overnight before they were incubated as porphyrins act as photo-sensitizers when irradiated with light. The polymer-attached porphyrin did exhibit antimicrobial activity and parameters that affect its efficiency will be discussed.

  12. Job Cognition and Justice Influencing Organizational Attachment

    Directory of Open Access Journals (Sweden)

    Sangeeta Sahu


    Full Text Available Organizational attachment echoes the psychological bond between employee and employer relations, differing from affective component of commitment in terms of employees’ psychological and behavioral involvement. This study examines the extent to which employee perception about procedural, distributive justice and job cognition contributes toward organizational attachment in India. The effect of justice and job cognition variables relates differently to previous studies from western part of the globe. First, in past studies, procedural justice predicted commitment, whereas, for Indian employees, distributive justice contributed to organizational attachment. Second, the contribution of extrinsic job cognition in organizational attachment was evident in the model developed using Structural Equation Modeling (SEM; AMOS. Organizations must take cognizance of the outcomes exhibited by the behavior of managers while following the laid down policies and processes. Cognition of fairness at workplace and attachment can play key role in limiting retention. Practical implications and future research directions are discussed.


    Directory of Open Access Journals (Sweden)

    Smirnov Vladimir Alexandrovich


    Full Text Available The article deals with the probability analysis for a vibration isolation system of high-precision equipment, which is extremely sensitive to low-frequency oscillations even of submicron amplitude. The external sources of low-frequency vibrations may include the natural city background or internal low-frequency sources inside buildings (pedestrian activity, HVAC. Taking Gauss distribution into account, the author estimates the probability of the relative displacement of the isolated mass being still lower than the vibration criteria. This problem is being solved in the three dimensional space, evolved by the system parameters, including damping and natural frequency. According to this probability distribution, the chance of exceeding the vibration criteria for a vibration isolation system is evaluated. Optimal system parameters - damping and natural frequency - are being developed, thus the possibility of exceeding vibration criteria VC-E and VC-D is assumed to be less than 0.04.

  14. Acceleration of the reaction OH + CO → H + CO2 by vibrational excitation of OH. (United States)

    Kohno, Nanase; Izumi, Mari; Kohguchi, Hiroshi; Yamasaki, Katsuyoshi


    The collision complex formed from a vibrationally excited reactant undergoes redissociation to the reactant, intramolecular vibrational relaxation (randomization of vibrational energy), or chemical reaction to the products. If attractive interaction between the reactants is large, efficient vibrational relaxation in the complex prevents redissociation to the reactants with the initial vibrational energy, and the complex decomposes to the reactants with low vibrational energy or converts to the products. In this paper, we have studied the branching ratios between the intramolecular vibrational relaxation and chemical reaction of an adduct HO(v)-CO formed from OH(X(2)Π(i)) in different vibrational levels v = 0-4 and CO. OH(v = 0-4) generated in a gaseous mixture of O(3)/H(2)/CO/He irradiated at 266 nm was detected with laser-induced fluorescence (LIF) via the A(2)Σ(+)-X(2)Π(i) transition, and H atoms were probed by the two-photon excited LIF technique. From the kinetic analysis of the time-resolved LIF intensities of OH(v) and H, we have found that the intramolecular vibrational relaxation is mainly governed by a single quantum change, HO(v)-CO → HO(v-1)-CO, followed by redissociation to OH(v-1) and CO. With the vibrational quantum number v, chemical process from the adduct to H + CO(2) is accelerated, and vibrational relaxation is decelerated. The countertrend is elucidated by the competition between chemical reaction and vibrational relaxation in the adduct HOCO.

  15. Vibrational energy relaxation pathways of water (United States)

    Pakoulev, Andrei; Wang, Zhaohui; Pang, Yoonsoo; Dlott, Dana D.


    Vibrational energy relaxation (VR) of the OH stretch νOH and bend δH 2O in water is studied by the mid-IR pump with anti-Stokes Raman probe technique. The broad νOH band in water consists of two inhomogeneously broadened subbands. VR in the larger red-shifted subband νOHR, with T1=0.55 ps, is shown to occur by the mechanism νOH→ δH 2O (1/3) and νOH → ground state (2/3). VR in the smaller longer-lived blue-shifted subband νOHB, with T1=0.75 ps, occurs by the mechanism νOH → ground state. The bending fundamental δH 2O decays directly to the ground state with T1=1.4 ps.

  16. Computer analysis of railcar vibrations (United States)

    Vlaminck, R. R.


    Computer models and techniques for calculating railcar vibrations are discussed along with criteria for vehicle ride optimization. The effect on vibration of car body structural dynamics, suspension system parameters, vehicle geometry, and wheel and rail excitation are presented. Ride quality vibration data collected on the state-of-the-art car and standard light rail vehicle is compared to computer predictions. The results show that computer analysis of the vehicle can be performed for relatively low cost in short periods of time. The analysis permits optimization of the design as it progresses and minimizes the possibility of excessive vibration on production vehicles.

  17. ER fluid applications to vibration control devices and an adaptive neural-net controller (United States)

    Morishita, Shin; Ura, Tamaki


    Four applications of electrorheological (ER) fluid to vibration control actuators and an adaptive neural-net control system suitable for the controller of ER actuators are described: a shock absorber system for automobiles, a squeeze film damper bearing for rotational machines, a dynamic damper for multidegree-of-freedom structures, and a vibration isolator. An adaptive neural-net control system composed of a forward model network for structural identification and a controller network is introduced for the control system of these ER actuators. As an example study of intelligent vibration control systems, an experiment was performed in which the ER dynamic damper was attached to a beam structure and controlled by the present neural-net controller so that the vibration in several modes of the beam was reduced with a single dynamic damper.

  18. Experimental investigation of the flow-induced vibration of hydrofoils in cavitating flows (United States)

    Wang, Guoyu; Wu, Qin; Huang, Biao; Gao, Yuan


    The objective of this paper is to investigate the correlation between fluid induced vibration and unsteady cavitation behaviours. Experimental results are presented for a modified NACA66 hydrofoil, which is fixed at α=8°. The high-speed camera is synchronized with a single point Laser Doppler Vibrometer to analyze the transient cavitating flow structures and the corresponding structural vibration characteristics. The results showed that, with the decreasing of the cavitation number, the cavitating flows in a water tunnel display several types of cavitation patterns, such as incipient cavitation, sheet cavitation and cloud cavitation. The cavity shedding frequency reduces with the decrease of the cavitation number. As for the cloud cavitation regime, the trend of the vibration velocity goes up with the growth of the attached cavity, accompanied with small amplitude fluctuations. Then the collapse and shedding of the large-scale cloud cavities leads to substantial increase of the vibration velocity fluctuations.

  19. Measurement of the Resonant Characteristics of a Single Bubble Vibration by Using a Laser Doppler Vibrometer (United States)

    Yoshikawa, Taisuke; Kotera, Hironori; Yoshida, Kenji; Koyama, Daisuke; Nakamura, Kentaro; Watanabe, Yoshiaki


    We constructed the experimental system with a laser Doppler vibrometer (LDV) for measuring the vibration of a single microbubble. It was demonstrated that the system enabled the capture of the vibration with an amplitude of nanometer order. We attempted to experimentally measure the resonant characteristics of a bubble attached to a wall by using the system. As a result, we succeeded in measuring the characteristics and evaluating the Q factor and the resonant radius at a driving frequency of 27.8 kHz, although these values are different from those predicted on the basis of the theory for a single free bubble. The LDV measurement system is expected to an effective tool for evaluating bubble vibrations with very small displacement amplitudes, such as the vibration of a microcapsule.

  20. Lattice Vibrations in Chlorobenzenes:

    DEFF Research Database (Denmark)

    Reynolds, P. A.; Kjems, Jørgen; White, J. W.


    Lattice vibrational dispersion curves for the ``intermolecular'' modes in the triclinic, one molecule per unit cell β phase of p‐C6D4Cl2 and p‐C6H4Cl2 have been obtained by inelastic neutron scattering. The deuterated sample was investigated at 295 and at 90°K and a linear extrapolation to 0°K...... by consideration of electrostatic forces or by further anisotropy in the dispersion forces not described in the atom‐atom model. Anharmonic effects are shown to be large, but the dominant features in the temperature variation of frequencies are describable by a quasiharmonic model....

  1. Anharmonic vibrations in nuclei

    CERN Document Server

    Fallot, M; Andrés, M V; Catara, F; Lanza, E G; Scarpaci, J A; Chomaz, Ph.


    In this letter, we show that the non-linearitites of large amplitude motions in atomic nuclei induce giant quadrupole and monopole vibrations. As a consequence, the main source of anharmonicity is the coupling with configurations including one of these two giant resonances on top of any state. Two-phonon energies are often lowered by one or two MeV because of the large matrix elements with such three phonon configurations. These effects are studied in two nuclei, 40Ca and 208Pb.

  2. Chaotic vortex induced vibrations

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, J.; Sheridan, J. [Fluids Laboratory for Aeronautical and Industrial Research (FLAIR), Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, Victoria 3800 (Australia); Leontini, J. S. [Department of Mechanical and Product Design Engineering, Swinburne University of Technology, Hawthorn, Victoria 3122 (Australia); Lo Jacono, D. [Institut de Mécanique des Fluides de Toulouse (IMFT), CNRS, UPS and Université de Toulouse, 31400 Toulouse (France)


    This study investigates the nature of the dynamic response of an elastically mounted cylinder immersed in a free stream. A novel method is utilized, where the motion of the body during a free vibration experiment is accurately recorded, and then a second experiment is conducted where the cylinder is externally forced to follow this recorded trajectory. Generally, the flow response during both experiments is identical. However, particular regimes exist where the flow response is significantly different. This is taken as evidence of chaos in these regimes.

  3. Man-Induced Vibrations

    DEFF Research Database (Denmark)

    Jönsson, Jeppe; Hansen, Lars Pilegaard


    Human motion can cause various types of periodic or transient dynamic loads. The periodic loads are mainly due to jumping, running, dancing, walking and body rocking. Transient loads primarily result from single impulse loads, such as jumping and falling from elevated positions. The response...... concerned with spectator-induced vertical vibrations on grandstands. The idea is to use impulse response analysis and base the load description on the load impulse. If the method is feasable, it could be used in connection with the formulation of requirements in building codes. During the last two decades...

  4. Characterisation of vibration input to flywheel used on urban bus (United States)

    Wang, L.; Kanarachos, S.; Christensen, J.


    Vibration induced from road surface has an impact on the durability and reliability of electrical and mechanical components attached on the vehicle. There is little research published relevant to the durability assessment of a flywheel energy recovery system installed on city and district buses. Relevant international standards and legislations were reviewed and large discrepancy was found among them, in addition, there are no standards exclusively developed for kinetic energy recovery systems on vehicles. This paper describes the experimentation of assessment of road surface vibration input to the flywheel on a bus as obtained at the MIRA Proving Ground. Power density spectra have been developed based on the raw data obtained during the experimentation. Validation of this model will be carried out using accelerated life time tests that will be carried out on a shaker rig using an accumulated profile based on the theory of fatigue damage equivalence in time and frequency domain aligned with the model predictions.

  5. Model reduction and analysis of a vibrating beam microgyroscope

    KAUST Repository

    Ghommem, Mehdi


    The present work is concerned with the nonlinear dynamic analysis of a vibrating beam microgyroscope composed of a rotating cantilever beam with a tip mass at its end. The rigid mass is coupled to two orthogonal electrodes in the drive and sense directions, which are attached to the rotating base. The microbeam is driven by an AC voltage in the drive direction, which induces vibrations in the orthogonal sense direction due to rotation about the microbeam axis. The electrode placed in the sense direction is used to measure the induced motions and extract the underlying angular speed. A reduced-order model of the gyroscope is developed using the method of multiple scales and used to examine its dynamic behavior. © The Author(s) 2012 Reprints and permissions:

  6. Spray characterization during vibration-induced drop atomization (United States)

    Vukasinovic, Bojan; Smith, Marc K.; Glezer, Ari


    Vibration-induced drop atomization is a process of rapid droplet ejection from a larger liquid drop. This occurs when a liquid drop resting on a thin diaphragm is vibrated under the appropriate forcing conditions using an attached piezoelectric actuator. The resulting spray of small droplets is characterized in this work using high-speed imaging and particle-tracking techniques. The results show that the average spatial and velocity distributions of the spray droplets are fairly axisymmetric during all stages of the atomization. The mean diameter of the droplets depends on the forcing frequency to the -2/3 power. The ejection velocity of the spray droplets depends on both the magnitude and the rate of change of the forcing amplitude. Thus, controlling the characteristics of the forcing signal may lead to strategies for controlling the spray process in specific applications.

  7. A principle of similarity for nonlinear vibration absorbers (United States)

    Habib, G.; Kerschen, G.


    This paper develops a principle of similarity for the design of a nonlinear absorber, the nonlinear tuned vibration absorber (NLTVA), attached to a nonlinear primary system. Specifically, for effective vibration mitigation, we show that the NLTVA should feature a nonlinearity possessing the same mathematical form as that of the primary system. A compact analytical formula for the nonlinear coefficient of the absorber is then derived. The formula, valid for any polynomial nonlinearity in the primary system, is found to depend only on the mass ratio and on the nonlinear coefficient of the primary system. When the primary system comprises several polynomial nonlinearities, we demonstrate that the NLTVA obeys a principle of additivity, i.e., each nonlinear coefficient can be calculated independently of the other nonlinear coefficients using the proposed formula.

  8. Vibration damping and heat transfer using material phase changes (United States)

    Kloucek, Petr (Inventor); Reynolds, Daniel R. (Inventor)


    A method and apparatus wherein phase changes in a material can dampen vibrational energy, dampen noise and facilitate heat transfer. One embodiment includes a method for damping vibrational energy in a body. The method comprises attaching a material to the body, wherein the material comprises a substrate, a shape memory alloy layer, and a plurality of temperature change elements. The method further comprises sensing vibrations in the body. In addition, the method comprises indicating to at least a portion of the temperature change elements to provide a temperature change in the shape memory alloy layer, wherein the temperature change is sufficient to provide a phase change in at least a portion of the shape memory alloy layer, and further wherein the phase change consumes a sufficient amount of kinetic energy to dampen at least a portion of the vibrational energy in the body. In other embodiments, the shape memory alloy layer is a thin film. Additional embodiments include a sensor connected to the material.

  9. Effect of Hand Transmitted Vibration through Tractor during Ploughing Field

    Directory of Open Access Journals (Sweden)

    Md. Zakaullah Zaka


    Full Text Available In this study, transmission of vibration from the steering wheel of the tractor without any trailer attached with it is discussed. The vibration measurements were carried out on the tractor randomly.An investigation was conducted to determine the transmission of vibration from the steering wheel of the hand tractor to the wrist and upper arm of the operator under actual field conditions during ploughing field. The vibration level on the steering wheel was measured and analyzed and the frequency spectra for the chosen working conditions were obtained. The results indicate that the maximum transmissibility was observed in the first two frequency interval (in Hz i.e. 1-20 and 20-40, which may harm the operator. The frequency interval was 1-20 (target-wrist, 1-20 (target-upper arm, 20-40 (base-steering, 20-40 (base-steering and frequency zone was 0.022, 0.3974, 0.2066 and 0.1531 respectively.

  10. Longitudinal association between adolescent attachment, adult romantic attachment, and emotion regulation strategies. (United States)

    Pascuzzo, Katherine; Cyr, Chantal; Moss, Ellen


    Attachment security towards parents and peers in adolescence, and romantic attachment styles and emotion regulation strategies in young adulthood, were evaluated using an eight-year longitudinal design. Fifty-six young adults completed the Inventory of Parent and Peer Attachment (IPPA) at age 14, and then, at age 22, the Experience in Close Relationships (ECR) and the Coping Inventory for Stressful Situations (CISS), an emotion regulation questionnaire concerning coping strategies, including task-oriented versus emotion-oriented foci. Results indicated that greater insecurity to parents and peers in adolescence predicted a more anxious romantic attachment style and greater use of emotion-oriented strategies in adulthood. Concurrently, anxious adult attachment style was related to more emotion-oriented strategies, whereas an avoidant attachment style was related to less support-seeking. Analyses also identified emotion-oriented coping strategies as a partial mediator of the link between adolescent attachment insecurity to parents and adult anxious attachment, and a complete mediator of the association between adolescent attachment insecurity to peers and adult anxious attachment. These findings support the core assumption of continuity in attachment theory, where relationships to parents influence close romantic relationships in adulthood.

  11. The attachment system in fledgling relationships: an activating role for attachment anxiety. (United States)

    Eastwick, Paul W; Finkel, Eli J


    Is it sensible to study attachment dynamics between potential romantic partners before they share a full-fledged attachment bond? The present data indicate that such an approach may reveal novel insights about initial attraction processes. Four studies suggest that the state-like experience of attachment anxiety has functional implications within fledgling (i.e., desired or undeveloped) romantic relationships, well before the formation of an attachment bond. Studies 1 and 3 reveal that attachment anxiety directed toward a particular romantic interest is elevated before (in comparison with after) participants report being in an established relationship. Studies 2 and 3 demonstrate that such partner-specific attachment anxiety predicts attachment-relevant outcomes in fledgling relationships, including proximity seeking, safe haven, secure base, passionate love, and other approach behaviors. These associations were reliable above and beyond (and were typically as strong as or stronger than) the effect of sexual desire. Finally, Study 4 presents evidence that partner-specific attachment anxiety may cause several of these attachment-relevant outcomes. Attachment anxiety seems to be a normative experience and may signal the activation of the attachment system during the earliest stages of romantic relationships.

  12. Vibrational relaxation and vibrational cooling in low temperature molecular crystals (United States)

    Hill, Jeffrey R.; Chronister, Eric L.; Chang, Ta-Chau; Kim, Hackjin; Postlewaite, Jay C.; Dlott, Dana D.


    The processes of vibrational relaxation (VR) and vibrational cooling (VC) are investigated in low temperature crystals of complex molecules, specifically benzene, naphthalene, anthracene, and durene. In the VR process, a vibration is deexcited, while VC consists of many sequential and parallel VR steps which return the crystal to thermal equilibrium. A theoretical model is developed which relates the VR rate to the excess vibrational energy, the molecular structure, and the crystal structure. Specific relations are derived for the vibrational lifetime T1 in each of three regimes of excess vibrational energy. The regimes are the following: Low frequency regime I where VR occurs by emission of two phonons, intermediate frequency regime II where VR occurs by emission of one phonon and one vibration, and high frequency regime III where VR occurs by evolution into a dense bath of vibrational combinations. The VR rate in each regime depends on a particular multiphonon density of states and a few averaged anharmonic coefficients. The appropriate densities of states are calculated from spectroscopic data, and together with available VR data and new infrared and ps Raman data, the values of the anharmonic coefficients are determined for each material. The relationship between these parameters and the material properties is discussed. We then describe VC in a master equation formalism. The transition rate matrix for naphthalene is found using the empirically determined parameters of the above model, and the time dependent redistribution in each mode is calculated.

  13. Preschool teacher attachment and attention skills. (United States)

    Commodari, Elena


    Attention underlies and energizes all cognitive and behavioral activities. Many studies showed that the quality of child attachment (both to parental and non parental figures) influences cognitive functions and attention. This study aimed to investigate the relationships among attachment to preschool teachers and attention in a sample of preschoolers. In particular, the study analyzed whether child attachment security to preschool teachers influences the different aspects of their attention skills. In addition, gender- and age-related differences in attention and teacher attachment were explored. Research was conducted using two standardized instruments: the Attention and Concentration Battery, and the Attachment Q Sort. Participants were 279 children (147 male, 132 female) who attended two preschools in a town in Southern Italy. Descriptive analyses, t-tests analyses, and correlation and regression analyses were carried out. Findings highlighted several interesting points concerning the relationships that occur among attachment to preschool teachers and attention. Children with secure attachments presented higher reaction time and better auditory, visual, and visual spatial selectivity and maintenance.

  14. Environmental and genetic influences on early attachment

    Directory of Open Access Journals (Sweden)

    Gervai Judit


    Full Text Available Abstract Attachment theory predicts and subsequent empirical research has amply demonstrated that individual variations in patterns of early attachment behaviour are primarily influenced by differences in sensitive responsiveness of caregivers. However, meta-analyses have shown that parenting behaviour accounts for about one third of the variance in attachment security or disorganisation. The exclusively environmental explanation has been challenged by results demonstrating some, albeit inconclusive, evidence of the effect of infant temperament. In this paper, after reviewing briefly the well-demonstrated familial and wider environmental influences, the evidence is reviewed for genetic and gene-environment interaction effects on developing early attachment relationships. Studies investigating the interaction of genes of monoamine neurotransmission with parenting environment in the course of early relationship development suggest that children's differential susceptibility to the rearing environment depends partly on genetic differences. In addition to the overview of environmental and genetic contributions to infant attachment, and especially to disorganised attachment relevant to mental health issues, the few existing studies of gene-attachment interaction effects on development of childhood behavioural problems are also reviewed. A short account of the most important methodological problems to be overcome in molecular genetic studies of psychological and psychiatric phenotypes is also given. Finally, animal research focusing on brain-structural aspects related to early care and the new, conceptually important direction of studying environmental programming of early development through epigenetic modification of gene functioning is examined in brief.

  15. An attachment research perspective on ADHD. (United States)

    Kissgen, Ruediger; Franke, Sebastian


    Since the beginning of clinical attachment research in the mid-1980s the number of research projects in this area has been continuously increasing. The research questions so far can be allocated to numerous medical disciplines such as psychosomatic medicine, adult psychiatry or child and adolescent psychiatry. Recently, children with ADHD and their families have also become subjects of this branch of research. Their specific behavioral characteristics from early childhood on constitute unique challenges on the parent-child interaction. If these interactions develop in a suboptimal way, children may develop an insecure or even a disorganized attachment quality. The latter represents a risk factor for a clinically significant psychopathological development.This article initially presents basic principles of attachment theory and discusses the relevance of the cardinal symptoms of ADHD for clinical attachment research. Subsequently, it outlines and discusses the main results of existing research regarding attachment and ADHD. It concludes with a perspective on research questions that need to be addressed in the future with regard to a transgenerational model that highlights the importance of parental attachment representations to the development of children's attachment quality.

  16. Carbon-deuterium bonds as non-perturbative infrared probes of protein dynamics, electrostatics, heterogeneity, and folding. (United States)

    Zimmermann, Jörg; Romesberg, Floyd E


    Vibrational spectroscopy is uniquely able to characterize protein dynamics and microenvironmental heterogeneity because it possesses an inherently high temporal resolution and employs probes of ultimately high structural resolution-the bonds themselves. The use of carbon-deuterium (C-D) bonds as vibrational labels circumvents the spectral congestion that otherwise precludes the use of vibrational spectroscopy to proteins and makes the observation of single vibrations within a protein possible while being wholly non-perturbative. Thus, C-D probes can be used to site-specifically characterize conformational heterogeneity and thermodynamic stability. C-D probes are also uniquely useful in characterizing the electrostatic microenvironment experienced by a specific residue side chain or backbone due to its effect on the C-D absorption frequency. In this chapter we describe the experimental procedures required to use C-D bonds and FT IR spectroscopy to characterize protein dynamics, structural and electrostatic heterogeneity, ligand binding, and folding.

  17. Carbon nanotubes as in vivo bacterial probes (United States)

    Bardhan, Neelkanth M.; Ghosh, Debadyuti; Belcher, Angela M.


    With the rise in antibiotic-resistant infections, non-invasive sensing of infectious diseases is increasingly important. Optical imaging, although safer and simpler, is less developed than other modalities such as radioimaging, due to low availability of target-specific molecular probes. Here we report carbon nanotubes (SWNTs) as bacterial probes for fluorescence imaging of pathogenic infections. We demonstrate that SWNTs functionalized using M13 bacteriophage (M13-SWNT) can distinguish between F‧-positive and F‧-negative bacterial strains. Moreover, through one-step modification, we attach an anti-bacterial antibody on M13-SWNT, making it easily tunable for sensing specific F‧-negative bacteria. We illustrate detection of Staphylococcus aureus intramuscular infections, with ~3.4 × enhancement in fluorescence intensity over background. SWNT imaging presents lower signal spread ~0.08 × and higher signal amplification ~1.4 × , compared with conventional dyes. We show the probe offers greater ~5.7 × enhancement in imaging of S. aureus infective endocarditis. These biologically functionalized, aqueous-dispersed, actively targeted, modularly tunable SWNT probes offer new avenues for exploration of deeply buried infections.

  18. On the attached length of orifices (United States)

    Komkin, A. I.; Mironov, M. A.; Yudin, S. I.


    The attached length of orifices in reactive mufflers has been estimated based on numerical calculations by the finite-element method. The numerical results for a diaphragm in a duct are compared with the theoretical data obtained by Rayleigh, Fock, Karal, and Ingard. The dependence of the attached length on the diaphragm thickness is given. The results obtained are generalized for the case in which the orifice is a Helmholtz resonator neck. The effect of the resonator length on the attached length of the neck is analyzed.

  19. Combined Prosthesis with Extracoronal Castable Precision Attachments

    Directory of Open Access Journals (Sweden)

    Naveen Gupta


    Full Text Available Satisfactory restoration in a patient with a partially edentulous situation can be challenging especially when unilateral or bilateral posterior segment of teeth is missing. Successful restoration can be done with various conventional and contemporary treatment options. One such treatment modality is attachment-retained cast partial dentures. This paper describes a case report of a patient with maxillary bilateral distal extension edentulous span restored with a cast partial denture having an extracoronal castable precision attachment (RHEIN 83 OT CAP attachments system.

  20. A tip-attached tuning fork sensor for the control of DNA translocation through a nanopore (United States)

    Hyun, Changbae; Kaur, Harpreet; Huang, Tao; Li, Jiali


    In this work, we demonstrate that a tuning fork can be used as a force detecting sensor for manipulating DNA molecules and for controlling the DNA translocation rate through a nanopore. One prong of a tuning fork is glued with a probe tip which DNA molecules can be attached to. To control the motion and position of the tip, the tuning fork is fixed to a nanopositioning system which has sub-nanometer position control. A fluidic chamber is designed to fulfill many requirements for the experiment: for the access of a DNA-attached tip approaching to a nanopore, for housing a nanopore chip, and for measuring ionic current through a solid-state nanopore with a pair of electrodes. The location of a nanopore is first observed by transmission electron microscopy, and then is determined inside the liquid chambers with an optical microscope combined with local scanning the probe tip on the nanopore surface. When a DNA-immobilized tip approaches a membrane surface near a nanopore, free ends of the immobilized DNA strings can be pulled and trapped into the pore by an applied voltage across the nanopore chip, resulting in an ionic current reduction through the nanopore. The trapped DNA molecules can be lifted up from the nanopore at a user controlled speed. This integrated apparatus allows manipulation of biomolecules (DNA, RNA, and proteins) attached to a probe tip with sub-nanometer precision, and simultaneously allows measurement of the biomolecules by a nanopore device.

  1. Give Them Roots, Then Let Them Fly: Understanding Attachment Therapy. (United States)

    McKelvey, Carole A., Ed.

    This book describes attachment theory, presents the attachment therapy program in place at the Evergreen Attachment Center at Evergreen, Colorado, and examines the implications of attachment therapy. The chapters are: (1) "An Overview" (Carole A. McKelvey, John Alston); (2) "Attachment Theory and Assessment" (Michael Orlans, Terry Levy); (3)…

  2. 30 CFR 77.1436 - Drum end attachment. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drum end attachment. 77.1436 Section 77.1436... Hoisting Wire Ropes § 77.1436 Drum end attachment. (a) For drum end attachment, wire rope shall be attached... anchor bolts, clamps, or wedges, provided that the attachment is a design feature of the hoist...

  3. Vibrations and Stability: Solved Problems

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel

    Worked out solutions for exercise problems in J. J. Thomsen 'Vibrations and Stability: Advanced Theory, Analysis, and Tools', Springer, Berlin - Heidelberg, 2003.......Worked out solutions for exercise problems in J. J. Thomsen 'Vibrations and Stability: Advanced Theory, Analysis, and Tools', Springer, Berlin - Heidelberg, 2003....

  4. Vibrational spectra of ordered perovskites

    NARCIS (Netherlands)

    Corsmit, A.F.; Hoefdraad, H.E.; Blasse, G.


    The vibrational spectra of the molecular M6+O6 (M = Mo, Te, W) group in ordered perovskites of the type Ba2M2+M6+O6 are reported. These groups have symmetry Oh, whereas their site symmetry is also Oh. An assignment of the internal vibrations is presented.

  5. Studies Of Vibrations In Gearboxes (United States)

    Choy, Fred K.; Ruan, Yeefeng F.; Tu, Yu K.; Zakrajsek, James J.; Oswald, Fred B.; Coy, John J.; Townsend, Dennis P.


    Three NASA technical memorandums summarize studies of vibrations in gearboxes. Directed toward understanding and reducing gearbox noise caused by coupling of vibrations from meshing gears, through gear shafts and their bearings, to surfaces of gearbox housings. Practical systems in which understanding and reduction of gearbox noise beneficial include helicopter, car, and truck transmissions; stationary geared systems; and gear-driven actuator systems.

  6. Interferometric strain measurements with a fiber-optic probe (United States)

    Burnham-Fay, E. D.; Jacobs-Perkins, D. W.; Ellis, J. D.


    Experience at the Laboratory for Laser Energetics has shown that broadband base vibrations make it difficult to position cryogenic inertial confinement fusion targets. These effects must be mitigated for National Ignition Facility-scale targets; to this end an active vibration stabilization system is proposed. A single-mode optical fiber strain probe and a novel fiber contained heterodyne interferometer have been developed as a position feedback sensor for the vibration control system. A resolution limit of 54.5 nƐ; is measured with the optical strain gauge, limited by the lock-in amplifier. Experimental measurements of the sensor that show good agreement with reference resistive strain gauge measurements are presented.

  7. Nuclear probes and intraoperative gamma cameras. (United States)

    Heller, Sherman; Zanzonico, Pat


    Gamma probes are now an important, well-established technology in the management of cancer, particularly in the detection of sentinel lymph nodes. Intraoperative sentinel lymph node as well as tumor detection may be improved under some circumstances by the use of beta (negatron or positron), rather than gamma detection, because the very short range (∼ 1 mm or less) of such particulate radiations eliminates the contribution of confounding counts from activity other than in the immediate vicinity of the detector. This has led to the development of intraoperative beta probes. Gamma camera imaging also benefits from short source-to-detector distances and minimal overlying tissue, and intraoperative small field-of-view gamma cameras have therefore been developed as well. Radiation detectors for intraoperative probes can generally be characterized as either scintillation or ionization detectors. Scintillators used in scintillation-detector probes include thallium-doped sodium iodide, thallium- and sodium-doped cesium iodide, and cerium-doped lutecium orthooxysilicate. Alternatives to inorganic scintillators are plastic scintillators, solutions of organic scintillation compounds dissolved in an organic solvent that is subsequently polymerized to form a solid. Their combined high counting efficiency for beta particles and low counting efficiency for 511-keV annihilation γ-rays make plastic scintillators well-suited as intraoperative beta probes in general and positron probes in particular Semiconductors used in ionization-detector probes include cadmium telluride, cadmium zinc telluride, and mercuric iodide. Clinical studies directly comparing scintillation and semiconductor intraoperative probes have not provided a clear choice between scintillation and ionization detector-based probes. The earliest small field-of-view intraoperative gamma camera systems were hand-held devices having fields of view of only 1.5-2.5 cm in diameter that used conventional thallium

  8. Magnetically Attached Multifunction Maintenance Rover (United States)

    Bar-Cohen, Yoseph; Joffe, Benjamin


    A versatile mobile telerobot, denoted the magnetically attached multifunction maintenance rover (MAGMER), has been proposed for use in the inspection and maintenance of the surfaces of ships, tanks containing petrochemicals, and other large ferromagnetic structures. As its name suggests, this robot would utilize magnetic attraction to adhere to a structure. As it moved along the surface of the structure, the MAGMER would perform tasks that could include close-up visual inspection by use of video cameras, various sensors, and/or removal of paint by water-jet blasting, laser heating, or induction heating. The water-jet nozzles would be mounted coaxially within compressed-air-powered venturi nozzles that would collect the paint debris dislodged by the jets. The MAGMER would be deployed, powered, and controlled from a truck, to which it would be connected by hoses for water, compressed air, and collection of debris and by cables for electric power and communication (see Figure 1). The operation of the MAGMER on a typical large structure would necessitate the use of long cables and hoses, which can be heavy. To reduce the load of the hoses and cables on the MAGMER and thereby ensure its ability to adhere to vertical and overhanging surfaces, the hoses and cables would be paid out through telescopic booms that would be parts of a MAGMER support system. The MAGMER would move by use of four motorized, steerable wheels, each of which would be mounted in an assembly that would include permanent magnets and four pole pieces (see Figure 2). The wheels would protrude from between the pole pieces by only about 3 mm, so that the gap between the pole pieces and the ferromagnetic surface would be just large enough to permit motion along the surface but not so large as to reduce the magnetic attraction excessively. In addition to the wheel assemblies, the MAGMER would include magnetic adherence enhancement fixtures, which would comprise arrays of permanent magnets and pole pieces

  9. The origins of vibration theory (United States)

    Dimarogonas, A. D.


    The Ionian School of natural philosophy introduced the scientific method of dealing with natural phenomena and the rigorous proofs for abstract propositions. Vibration theory was initiated by the Pythagoreans in the fifth century BC, in association with the theory of music and the theory of acoustics. They observed the natural frequency of vibrating systems and proved that it is a system property and that it does not depend on the excitation. Pythagoreans determined the fundamental natural frequencies of several simple systems, such as vibrating strings, pipes, vessels and circular plates. Aristoteles and the Peripatetic School founded mechanics and developed a fundamental understanding of statics and dynamics. In Alexandrian times there were substantial engineering developments in the field of vibration. The pendulum as a vibration, and probably time, measuring device was known in antiquity, and was further developed by the end of the first millennium AD.

  10. Exploiting synthetic aperture radar imagery for retrieving vibration signatures of concealed machinery (United States)

    Pérez, Francisco; Campbell, Justin B.; Jaramillo, Monica; Dunkel, Ralf; Atwood, Thomas; Doerry, Armin; Gerstle, Walter H.; Santhanam, Balu; Hayat, Majeed M.


    It has been demonstrated that the instantaneous acceleration associated with vibrating objects that are directly imaged by synthetic aperture radar (SAR) can be estimated through the application of the discrete fractional Fourier transform (DFrFT) using the information contained in the complex SAR image. In general, vibration signatures may include, for example, the number of chirped sinusoids as well as their respective base frequencies and chirp rates. By further processing the DFrFT-processed data for clutter-noise rejection by means of pseudo- subspace methods, has been shown that the SAR-vibrometry method can be reliable as long as the signal-to-noise ratio (SNR) and the signal-to-clutter ratio (SCR) of the slow-time SAR signal at the range-line of interest exceeds 15dB. Meanwhile, the Nyquist theorem dictates that the maximum measurable vibration frequency is limited by half of the pulse-repetition frequency. This paper focuses on the detection and estimation of vibrations generated by machinery concealed within buildings and other structures. This is a challenging task in general because the vibration signatures of the source are typically altered by their housing structure; moreover, the SNR at the surface of the housing structure tends to be reduced. Here, experimental results for three different vibrating targets, including one concealed target, are reported using complex SAR images acquired by the General Atomics Lynx radar at resolutions of 1-ft and 4-in. The concealed vibrating target is actuated by a gear motor with an off-balance weight attached to it, which is enclosed by a wooden housing. The vibrations of the motor are transmitted to a chimney that extends above the housing structure. Using the SAR vibrometry approach, it is shown that it is possible to distinguish among the three vibrating objects based upon their vibration signatures.

  11. Are anxiously attached women better mindreaders? (United States)

    Hünefeldt, Thomas; Laghi, Fiorenzo; Ortu, Francesca


    This research was aimed at providing first evidence concerning the relationship between adults' self-reported attachment style and their performance on a standard 'theory of mind' task. Based on adult attachment theory, we hypothesized that the two dimensions of self-reported adult attachment, anxiety and avoidance, are differently related to 'theory of mind,' and that this relationship is moderated by variables concerning the 'theory of mind' stimuli. The 'Experiences in Close Relationships' questionnaire and the 'Reading the Mind in the Eyes' test were administered to 132 young women. In line with our expectations, women's attachment-related anxiety was associated with better mind reading concerning stimuli that were emotionally neutral or difficult to recognize.

  12. Personality disorders, attachment and psychodynamic psychotherapy. (United States)

    Weinstein, Lissa; Perez-Rodriguez, M Mercedes; Siever, Larry


    While attachment has been a fruitful and critical concept in understanding enduring individual templates for interpersonal relationships, it does not have a well-understood relationship to personality disorders, where impairment of interpersonal functioning is paramount. Despite the recognition that attachment disturbances do not simply reflect nonoptimal caretaking environments, the relationship of underlying temperamental factors to these environmental insults has not been fully explored. In this paper we provide an alternate model for the role of neurobiological temperamental factors, including brain circuitry and neuropeptide modulation, in mediating social cognition and the internalization and maintenance of attachment patterns. The implications of these altered attachment patterns on personality disorders and their neurobiological and environmental roots for psychoanalytically based treatment models designed to ameliorate difficulties in interpersonal functioning through the medium of increased access to mature forms of mentalization is discussed.

  13. God as an Attachment Figure : A Case Study of the God Attachment Language and God Concepts of Anxiously Attached Christian Youths in South Africa

    NARCIS (Netherlands)

    Counted, Victor


    This study examines the role of the Christian God as an attachment figure, using the attachment language criteria of a strong and enduring affectionate bond. Respondents were 15 anxiously attached Christian youths, purposefully selected for in-depth interviews to explore their God attachment languag

  14. Attachment of Gold Nanoparticles to Carbon Nanotubes

    Institute of Scientific and Technical Information of China (English)

    Xi Cheng MA; Ning LUN; Shu Lin WEN


    Carbon nanotubes were initially chemically modified with an H2SO4-HNO3 treatment,and subsequently activated with Pd-Sn catalytic nuclei via a one-step activation approach. These activated nanotubes were used as precursors for obtaining gold nanoparticles-attached nanotubes via simple electroless plating. This approach provides an efficient method for attachment of metal nanostructures to carbon nanotubes. Such novel hybrid nanostructures are attractive for many applications.

  15. Understanding Members’ Attachment to Social Networking Sites

    DEFF Research Database (Denmark)

    Lim, Eric T. K.; Cyr, Dianne; Tan, Chee-Wee


    Social Networking Sites (SNSs) are pervasive phenomena in today’s society. With greater connectivity and interactivity enabled through emerging technologies, SNSs provide communication platforms for individuals to bridge spatial and temporal differences when making friends, sharing experiences...... and competitive mentality towards others within SNSs. We further construct a theoretical model of members’ communal attachments within SNSs that is then empirically validated via an online survey of 787 active members of SNSs. Empirical findings suggest that members’ communal attachments play an instrumental role...

  16. Structure and behaviour of proteins, nucleic acids and viruses from vibrational Raman optical activity

    DEFF Research Database (Denmark)

    Barron, L.D.; Blanch, E.W.; McColl, I.H.;


    On account of its sensitivity to chirality Raman optical activity (ROA), which may be measured as a small difference in vibrational Raman scattering from chiral molecules in right- and left-circularly polarized incident light, is a powerful probe of structure and behaviour of biomolecules in aque...

  17. Broadband UV-Vis vibrational coherence spectrometer based on a hollow fiber compressor (United States)

    Gueye, Moussa; Nillon, Julien; Crégut, Olivier; Léonard, Jérémie


    We describe a broadband transient absorption (TA) spectrometer devised to excite and probe, in the blue to UV range, vibrational coherence dynamics in organic molecules in condensed phase. A 800-nm Ti:Sa amplifier and a hollow fiber compressor are used to generate a 6-fs short pulse at 1 kHz. Broadband sum frequency generation with the fundamental pulse is implemented to produce a 400-nm, 8-fs Fourier limited short pulse. A UV-Vis white-light supercontinuum is implemented as a probe with intensity self-referencing to achieve a shot-noise-limited sensitivity. Rapid scanning of the pump-probe delay is shown very efficient in suppressing the noise resulting from low-frequency pump intensity fluctuations. Using either of the 800-nm or 400-nm broadband pulses as the pump for TA spectroscopy of organic molecules in solution, we resolve oscillatory signals down to the 320 nm probing wavelength with a 3200 cm-1 FWHM bandwidth. Their Fourier transformation reveals the corresponding molecular vibrational spectra. Finally, we demonstrate the use of this setup as a vibrational coherence spectrometer for the investigation of the vibrational dynamics accompanying the sub-ps C=C photoisomerization of a retinal-like molecular switch through a conical intersection.

  18. Personality and Attachment in Transsexual Adults. (United States)

    Lingiardi, Vittorio; Giovanardi, Guido; Fortunato, Alexandro; Nassisi, Valentina; Speranza, Anna Maria


    The main aim of this study was to investigate the associations between personality features and attachment patterns in transsexual adults. We explored mental representations of attachment, assessed personality traits, and possible personality disorders. Forty-four individuals diagnosed with gender identity disorder (now gender dysphoria), 28 male-to-female and 16 female-to-male, were evaluated using the Shedler-Westen assessment procedure-200 (SWAP-200) to assess personality traits and disorders; the adult attachment interview was used to evaluate their attachment state-of-mind. With respect to attachment, our sample differed both from normative samples because of the high percentage of disorganized states of mind (50% of the sample), and from clinical samples for the conspicuous percentage of secure states of mind (37%). Furthermore, we found that only 16% of our sample presented a personality disorder, while 50% showed a high level of functioning according to the SWAP-200 scales. In order to find latent subgroups that shared personality characteristics, we performed a Q-factor analysis. Three personality clusters then emerged: Healthy Functioning (54% of the sample); Depressive/Introverted (32%) and Histrionic/Extroverted (14%). These data indicate that in terms of personality and attachment, GD individuals are a heterogeneous sample and show articulate and diverse types with regard to these constructs.

  19. Attachment of Adolescents to Parents: Turkey Profile

    Directory of Open Access Journals (Sweden)

    Turkan Dogan


    Full Text Available The present study aims to determine the attachment of adolescents to their parents according to geographical regions in Turkey and gender. The research group consisted of 6061 adolescents. With an age average of 15.53 years. The Inventory of Attachment to Parents and Friends- Brief Form (EABE was used as data acquisition tool. The results of the study indicated significant difference between the scores of students regarding the inventory of attachment to parents according to regions. Evaluating the findings regarding attachment to father and mother together, the findings were similar, and the attachment levels of adolescents in Middle Anatolia, Eastern Anatolia and Black Sea Region were found to be higher than the ones in other regions. This result may be related with socioeconomic, geographical and cultural structures of the regions. Examining the finding according to gender variable, the scores of male students are significantly lower than the scores of female students. As a result according to the data gained from a wide sample group; the main factors for the attachment of adolescents to their parents in Turkey are the geographical regions in Turkey and the gender. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2016; 8(4.000: 406-419

  20. The relationship between attachment and cognitive development

    Directory of Open Access Journals (Sweden)

    Tošić Milica


    Full Text Available Emotional and cognitive development of personality have mostly been explored independently in the history of psychology. However, in the last decades, there have been more and more frequent arguments in favour of the idea that the emotional relationship between the mother and the child in early childhood, through forming a secure or insecure attachment style, is to a certain extent linked to the cognitive development. For example, securely attached children, compared to the insecurely attached, have more frequent and longer episodes of symbolic play and are more advanced in the domain of language in early childhood. Securely attached children are also more efficient and persistent in solving problems. Before starting school, securely attached children understand better the feelings and beliefs of others, as well as the fact that these determine people’s behaviour, thus having an opportunity to understand and predict this behaviour better. In this paper, we will attempt to point out some of the mechanisms that are assumed to be mediators between the emotional and cognitive development. Namely, since it enables a more independent exploration of the surroundings, more quality social relations among children, higher self-esteem, better focus and more developed communicative skills, secure attachment might potentially be linked to the cognitive development. [Projekat Ministarstva nauke Republike Srbije, br. 179002

  1. Attachment Theory and the Social Work Curriculum

    Directory of Open Access Journals (Sweden)

    Timothy Page


    Full Text Available Attachment theory, as developed by Bowlby and Ainsworth, represented a major departure from the current theories of human development of the time, particularly in its rejection of the major tenets of psychoanalytic theory and its integration of core ideas from evolution theory and cybernetics (Ainsworth & Bowlby, 1991. Attachment theory posits that a foundational human instinct, the desire to achieve safety and protection through proximity to a protective figure, is responsible for the formation of a special class of life-long affectional bonds, referred to as “attachments.” Emotional security is derived to a great extent, according to the theory, from experience with caregivers who are consistently responsive to the developing infant’s expression of attachment behavior toward them. Forty years of empirical research has shown that attachment is a universal characteristic that predicts children’s development of cognitive and social competence, emotional regulation, and positive self-image (Weinfield, Sroufe, Egeland, & Carlson, 1999. Social work educators are currently challenged to better integrate the findings of attachment research into their curricula to reflect more the current state of developmental science.

  2. Vibrational relaxation of NO stretching modes in ferrous NO and ferric NO in model heme (United States)

    Park, Jaeheung; Lee, Taegon; Lim, Manho


    Femtosecond IR-pump-IR-probe spectroscopy was used to measure the vibrational lifetimes (T1) of NO stretching modes of ferrous NO near 1600 cm-1 and ferric NO near 1900 cm-1 at room temperature. The T1 of NO bound to the heme, ranging from 3.5 to 34 ps, is much shorter in ferrous NO. The vibrational relaxation (VR) of NO was independent of solvent used and excess imidazole concentration, suggesting that intramolecular VR into the internal vibrational modes of the probed molecule may be the dominant pathway for VR of the bound NO. With estimated T1 of the bound NO, we simulated transient spectra of NO bound to ferrous hemoglobin (HbII) after photodeligation of HbIINO and discussed the influence of the hot band on the determination of the dynamics of geminate rebinding of NO to HbII using the change in the magnitude of the fundamental band.

  3. Characterization of single 1.8-nm Au nanoparticle attachments on AFM tips for single sub-4-nm object pickup. (United States)

    Cheng, Hui-Wen; Chang, Yuan-Chih; Tang, Song-Nien; Yuan, Chi-Tsu; Tang, Jau; Tseng, Fan-Gang


    This paper presents a novel method for the attachment of a 1.8-nm Au nanoparticle (Au-NP) to the tip of an atomic force microscopy (AFM) probe through the application of a current-limited bias voltage. The resulting probe is capable of picking up individual objects at the sub-4-nm scale. We also discuss the mechanisms involved in the attachment of the Au-NP to the very apex of an AFM probe tip. The Au-NP-modified AFM tips were used to pick up individual 4-nm quantum dots (QDs) using a chemically functionalized method. Single QD blinking was reduced considerably on the Au-NP-modified AFM tip. The resulting AFM tips present an excellent platform for the manipulation of single protein molecules in the study of single protein-protein interactions.

  4. Pioneer Jupiter orbiter probe mission 1980, probe description (United States)

    Defrees, R. E.


    The adaptation of the Saturn-Uranus Atmospheric Entry Probe (SUAEP) to a Jupiter entry probe is summarized. This report is extracted from a comprehensive study of Jovian missions, atmospheric model definitions and probe subsystem alternatives.

  5. Attachment to the Romantic Partner and Sibling: Attachment Hierarchies of Twins and Non-Twin Siblings

    Directory of Open Access Journals (Sweden)

    Sascha Schwarz


    Full Text Available Previous studies have shown that romantic partners and siblings are important attachment figures. This study compares the attachment to the romantic partner with the attachment to the sibling as a function of the participant’s sibling type among monozygotic (MZ twins, dizygotic (DZ twins, and non-twin (NT siblings. The results show that MZ twins prefer their sibling to their romantic partner whereas DZ twins are equally attached to their sibling and romantic partner. In contrast, NT siblings are more attached to their romantic partner compared to their sibling. These results indicate that genetic relatedness has profound impact on a person’s attachment hierarchy and the relative rank of the romantic partner and the sibling.

  6. Laparoscopic four-way ultrasound probe with histologic biopsy facility using a flexible tru-cut needle

    DEFF Research Database (Denmark)

    Durup Scheel-Hincke, J; Mortensen, M B; Pless, T;


    Laparoscopic ultrasound (LUS) is widely used in the staging of upper gastrointestinal malignancies. However, accurate N-staging and pathological confirmation of metastases have proved difficult. A new four-way laparoscopic ultrasound probe has been developed. The probe has a biopsy attachment......, the equipment and the technique are described....

  7. An experimental evaluation of the State Adult Attachment Measure: the influence of attachment primes on the content of state attachment representations


    Bosmans, Guy; Bowles, David P.; Dewitte, Marieke; Winter, Simon; Braet, Caroline


    Attachment theory predicts cross-contextual stability of attachment representations, but research findings are rather mixed. Recently, it has been suggested that these mixed findings reflect the existence of both state and trait attachment components. The development of the State Adult Attachment Measure (SAAM) has enabled an investigation of this hypothesis. The current study aimed to evaluate the extent to which the SAAM is a useful instrument for studying such state attachment hypotheses. ...

  8. An experimental evaluation of the State Adult Attachment Measure: The Influence of Attachment Primes on the Content of State Attachment Representations


    Bosmans, Guy; Bowles, David; Dewitte, Marieke; Winter, Simon; Braet, Caroline


    Attachment theory predicts cross-contextual stability of attachment representations, but research findings are rather mixed. Recently, it has been suggested that these mixed findings reflect the existence of both state and trait attachment components. The development of the State Adult Attachment Measure (SAAM) has enabled an investigation of this hypothesis. The current study aimed to evaluate the extent to which the SAAM is a useful instrument for studying such state attachment hypotheses. ...

  9. Simple vibration modeling of structural fuzzy with continuous boundary by including two-dimensional spatial memory

    DEFF Research Database (Denmark)

    Friis, Lars; Ohlrich, Mogens


    Many complicated systems of practical interest consist basically of a well-defined outer shell-like master structure and a complicated internal structure with uncertain dynamic properties. Using the "fuzzy structure theory" for predicting audible frequency vibration, the internal structure......-dimensional continuous boundary. Additionally, a simple method for determining the so-called equivalent coupling factor is presented. The validity of this method is demonstrated by numerical simulations of the vibration response of a master plate structure with fuzzy attachments. It is revealed that the method performs...

  10. Implant-supported mandibular overdentures retained with ball or bar attachments: a randomized prospective 5-year study

    DEFF Research Database (Denmark)

    Gotfredsen, K; Holm, B


    Astra Tech dental implants placed in the anterior part of the mandible. The denture attachment system for the patients was chosen randomly by drawing lots. Eleven patients drew the bar attachment system and fifteen patients drew the ball attachment system. Plaque Index, Gingival Index, and probing......PURPOSE: The aim of the present study was to evaluate the periimplant conditions and the maintenance requirements for implant-supported overdentures in the mandible retained with ball or bar attachments during a 5-year period. MATERIALS AND METHODS: Twenty-six completely edentulous patients had two...... pocket depth were assessed around each implant. Periotest values were recorded, and periodically identical intraoral radiographs were obtained with a specially designed film-holding device. RESULTS: No implants were lost from baseline to the 5-year registration. The periimplant conditions were very...

  11. Temperature-independent vibrational dynamics in an organic photovoltaic material. (United States)

    Pensack, Ryan D; Banyas, Kyle M; Asbury, John B


    Ultrafast orientational motion and spectral diffusion of the carbonyl stretch vibration of the functionalized fullerene, PCBM, blended with the conjugated polymer, CN-MEH-PPV, are examined with two-dimensional infrared and polarization-resolved IR pump probe spectroscopy. In previous contributions from our group, the carbonyl stretch frequency of PCBM has been used as a local vibrational reporter to measure the temperature dependence of the time scale for dissociation of charge transfer excitons in CN-MEH-PPV:PCBM polymer blends. It was found that the rate of charge separation is independent of temperature, indicating that charge separation occurs through an activationless pathway. This assignment was supported by the observation at room temperature that thermal fluctuations do not give rise to spectral diffusion of the carbonyl stretch vibration on the picosecond and longer time scale. In this contribution, we examine the temperature dependence of the carbonyl vibrational dynamics to determine whether thermal fluctuations might give rise to spectral diffusion at other temperatures. We find that the time scale for fast wobbling-in-cone orientational motion is independent of temperature on the subpicosecond time scale. Similarly, spectral diffusion is not observed on the picosecond and longer time scale at all temperatures examined confirming our earlier interpretation of the frequency shift dynamics exclusively in terms of charge separation. Interestingly, the half angle characterizing the wobbling-in-cone orientational motion does increase at higher temperature due to increased free-volume resulting from thermal expansion of the polymer blend.

  12. Fiber optic vibration sensor using bifurcated plastic optical fiber (United States)

    Abdullah, M.; Bidin, N.; Yasin, M.


    An extrinsic fiber optic vibration sensor is demonstrated for a fiber optic displacement sensor based on a bundled multimode fiber to measure a vibration frequency ranging from 100 until 3000 Hz. The front slope has a sensitivity of 0.1938mV/mm and linearity of 99.7% within a measurement range between 0.15-3.00 mm. By placing the diaphragm of the concave load-speaker within the linear range from the probe, the frequency of the vibration can be measured with error percentage of less than 1.54%. The graph of input against output frequency for low, medium and high frequency range show very high linearity up to 99%. Slope for low, medium, and high frequency range are calculated as 1.0026, 0.9934, and 1.0007 respectively. Simplicity, long term stability, low power consumption, wide dynamic and frequency ranges, noise reduction, ruggedness, linearity and light weight make it promising alternative to other well-establish methods for vibration frequency measurement.

  13. Frequency Identification of Vibration Signals Using Video Camera Image Data

    Directory of Open Access Journals (Sweden)

    Chia-Hung Wu


    Full Text Available This study showed that an image data acquisition system connecting a high-speed camera or webcam to a notebook or personal computer (PC can precisely capture most dominant modes of vibration signal, but may involve the non-physical modes induced by the insufficient frame rates. Using a simple model, frequencies of these modes are properly predicted and excluded. Two experimental designs, which involve using an LED light source and a vibration exciter, are proposed to demonstrate the performance. First, the original gray-level resolution of a video camera from, for instance, 0 to 256 levels, was enhanced by summing gray-level data of all pixels in a small region around the point of interest. The image signal was further enhanced by attaching a white paper sheet marked with a black line on the surface of the vibration system in operation to increase the gray-level resolution. Experimental results showed that the Prosilica CV640C CMOS high-speed camera has the critical frequency of inducing the false mode at 60 Hz, whereas that of the webcam is 7.8 Hz. Several factors were proven to have the effect of partially suppressing the non-physical modes, but they cannot eliminate them completely. Two examples, the prominent vibration modes of which are less than the associated critical frequencies, are examined to demonstrate the performances of the proposed systems. In general, the experimental data show that the non-contact type image data acquisition systems are potential tools for collecting the low-frequency vibration signal of a system.

  14. In-vehicle vibration study of child safety seats. (United States)

    Giacomin, J; Gallo, S


    This paper reports experimental measurements of the in-vehicle vibrational behaviour of stage 0&1 child safety seats. Road tests were performed for eight combinations of child, child seat and automobile. Four accelerometers were installed in the vehicles and orientated to measure as closely as possible in the vertical direction; two were attached to the floor and two located at the human interfaces. An SAE pad was placed under the ischial tuberosities of the driver at the seat cushion and a child pad, designed for the purpose of this study, was placed under the child. Four test runs were made over a pave' (cobblestone) surface for the driver's seat and four for the child seat at both 20 km h(-1) and 40 km h(-1). Power spectral densities were determined for all measurement points and acceleration transmissibility functions (ATFs) were estimated from the floor of the vehicle to the human interfaces. The system composed of automobile seat, child seat and child was found to transmit greater vibration than the system composed of automobile seat and driver. The ensemble mean transmissibility in the frequency range from 1 to 60 Hz was found to be 77% for the child seats systems as opposed to 61% for the driver's seats. The acceleration transmissibility for the child seat system was found to be higher than that of the driver's seat at most frequencies above 10 Hz for all eight systems tested. The measured ATFs suggest that the principal whole-body vibration resonance of the children occurred at a mean frequency of 8.5, rather than the 3.5 to 5.0 Hz typically found in the case of seated adults. It can be concluded that current belt-fastened child seats are less effective than the vehicle primary seating systems in attenuating vibrational disturbances. The results also suggest the potential inability of evaluating child comfort by means of existing whole-body vibration standards.

  15. Frequency identification of vibration signals using video camera image data. (United States)

    Jeng, Yih-Nen; Wu, Chia-Hung


    This study showed that an image data acquisition system connecting a high-speed camera or webcam to a notebook or personal computer (PC) can precisely capture most dominant modes of vibration signal, but may involve the non-physical modes induced by the insufficient frame rates. Using a simple model, frequencies of these modes are properly predicted and excluded. Two experimental designs, which involve using an LED light source and a vibration exciter, are proposed to demonstrate the performance. First, the original gray-level resolution of a video camera from, for instance, 0 to 256 levels, was enhanced by summing gray-level data of all pixels in a small region around the point of interest. The image signal was further enhanced by attaching a white paper sheet marked with a black line on the surface of the vibration system in operation to increase the gray-level resolution. Experimental results showed that the Prosilica CV640C CMOS high-speed camera has the critical frequency of inducing the false mode at 60 Hz, whereas that of the webcam is 7.8 Hz. Several factors were proven to have the effect of partially suppressing the non-physical modes, but they cannot eliminate them completely. Two examples, the prominent vibration modes of which are less than the associated critical frequencies, are examined to demonstrate the performances of the proposed systems. In general, the experimental data show that the non-contact type image data acquisition systems are potential tools for collecting the low-frequency vibration signal of a system.

  16. Bubble colloidal AFM probes formed from ultrasonically generated bubbles. (United States)

    Vakarelski, Ivan U; Lee, Judy; Dagastine, Raymond R; Chan, Derek Y C; Stevens, Geoffrey W; Grieser, Franz


    Here we introduce a simple and effective experimental approach to measuring the interaction forces between two small bubbles (approximately 80-140 microm) in aqueous solution during controlled collisions on the scale of micrometers to nanometers. The colloidal probe technique using atomic force microscopy (AFM) was extended to measure interaction forces between a cantilever-attached bubble and surface-attached bubbles of various sizes. By using an ultrasonic source, we generated numerous small bubbles on a mildly hydrophobic surface of a glass slide. A single bubble picked up with a strongly hydrophobized V-shaped cantilever was used as the colloidal probe. Sample force measurements were used to evaluate the pure water bubble cleanliness and the general consistency of the measurements.

  17. Molecular vibrations the theory of infrared and Raman vibrational spectra

    CERN Document Server

    Wilson, E Bright; Cross, Paul C


    Pedagogical classic and essential reference focuses on mathematics of detailed vibrational analyses of polyatomic molecules, advancing from application of wave mechanics to potential functions and methods of solving secular determinant.

  18. Magnetic damping of ski vibrations

    Energy Technology Data Exchange (ETDEWEB)

    Yonnet, J.-P. [CNRS, St. Martin d' Heres (France). Lab. d' Electrotech. de Grenoble; Patton, A.C.; Philippe; Arnould; Bressan, C. [CNRS, St. Martin d' Heres (France). Lab. d' Electrotech. de Grenoble]|[Skis Dynastar S.A., Sallanches (France)


    An original damping device has been developed to reduce ski vibrations. Ski movement is transmitted to a conductive sheet situated in a multipole magnetic field created by permanent magnets. The conductive sheet is simultaneously submitted to eddy current and friction forces, giving the damping effect. The eddy current damper is more efficient for high frequency than for low frequency vibrations and consequently is very well adapted to ski vibrations. Bench and snow tests show the positive effects of the damper, which will be commercially available before the end of this year. (orig.)

  19. Vibrational Spectroscopy of Methyl benzoate

    CERN Document Server

    Maiti, Kiran Sankar


    Methyl benzoate (MB) is studied as a model compound for the development of new IR pulse schemes with possible applicability to biomolecules. Anharmonic vibrational modes of MB are calculated on different level (MP2, SCS, CCSD(T) with varying basis sets) ab-initio PESs using the vibrational self-consistent field (VSCF) method and its correlation corrected extensions. Dual level schemes, combining different quantum chemical methods for diagonal and coupling potentials, are systematically studied and applied successfully to reduce the computational cost. Isotopic substitution of {\\beta}-hydrogen by deuterium is studied to obtain a better understanding of the molecular vibrational coupling topology.

  20. A distributed optical fiber sensing system for synchronous vibration and loss measurement (United States)

    Zhang, Xu-ping; Qiao, Wei-yan; Sun, Zhen-hong; Shan, Yuan-yuan; Zeng, Jie; Zhang, Yi-xin


    We propose a fully distributed fusion system combining phase-sensitive optical time-domain reflectometry (Φ-OTDR) and OTDR for synchronous vibration and loss measurement by setting an ingenious frequency sweep rate ( FSR) of the optical source. The relationships between FSR, probe pulse width and repeat period are given to balance the amplitude fluctuation of OTDR traces, the dead zone probability and the measurable frequency range of vibration events. In the experiment, we achieve synchronous vibration and loss measurement with FSR of 40 MHz/s, the proble pulse width of 100 ns and repeat rate of 0.4 ms. The fluctuation of OTDR trace is less than 0.45 dB when the signal-to-noise ratio ( SNR) is over 12 dB for a captured vibration event located at 9.1 km. The proposed method can be used for not only detection but also early warning of damage events in optical communication networks.

  1. Spectroscopic investigation of the vibrational quasi-continuum arising from internal rotation of a methyl group

    Energy Technology Data Exchange (ETDEWEB)

    Hougen, J.T. [NIST, Gaithersburg, MD (United States)


    The goal of this project is to use spectroscopic techniques to investigate in detail phenomena involving the vibrational quasi-continuum in a simple physical system. Acetaldehyde was chosen for the study because: (i) methyl groups have been suggested to be important promotors of intramolecular vibrational relaxation, (ii) the internal rotation of a methyl group is an easily describle large-amplitude motion, which should retain its simple character even at high levels of excitation, and (iii) the aldehyde carbonyl group offers the possibility of both vibrational and electronic probing. The present investigation of the ground electronic state has three parts: (1) understanding the {open_quotes}isolated{close_quotes} internal-rotation motion below, at, and above the top of the torsional barrier, (2) understanding in detail traditional (bond stretching and bending) vibrational fundamental and overtone states, and (3) understanding interactions involving states with multiquantum excitations of at least one of these two kinds of motion.

  2. Vibration Characteristics of Aircraft Engine-Bladed-Disk Assembly

    Directory of Open Access Journals (Sweden)

    J. S. Rao


    Full Text Available This paper is concerned with the vibration characteristics of a gas-turbine blade-disk assembly and a third stage of compressor blade-disk assembly of an orpheus aircraft engine. The assembly is analyzed by considering each component individually and then combining them together with a receptance coupling technique by matching forces and displacements at each junction point. The blade is modelled by number of free-free aerofoil section beams staggered at different angles to the plane of the disk, and the non-uniform disk is modelled as numbers of concentric annuli. The natural frequencies and mode shapes for each case have been obtained. Results obtained are verified by testing both the above assemblies on a microprocessor based vibration exciter and real time analyzer. The mode shape corresponding to each natural frequency was obtained by probing with hand held accelerometer.

  3. Vibrational and structural relaxation of hydrated protons in Nafion membranes (United States)

    Liu, Liyuan; Lotze, Stephan; Bakker, Huib J.


    We study the vibrational dynamics of the bending mode at 1730 cm-1 of proton hydration structures in Nafion membranes with polarization-resolved infrared (IR) pump-probe spectroscopy. The bending mode relaxes to an intermediate state with a time constant T1 of 170 ± 30 fs. Subsequently, the dissipated energy equilibrates with Teq of 1.5 ± 0.2 ps. The transient absorption signals show a long-living anisotropy, which indicates that for part of the excited proton hydration clusters the vibrational energy dissipation results in a local structural change, e.g. the breaking of a local hydrogen bond. This structural relaxation relaxes with a time constant of 38 ± 4 ps.

  4. Phase-referenced probe interferometer for biological surface profiling and displacement measurements (United States)

    Fang-Yen, Christopher; Chu, Mark C.; Seung, H. Sebastian; Dasari, Ramachandra R.; Feld, Michael S.


    We present a probe-based, phase-referenced low coherence interferometer in which the reference field is provided by a fiber end reflection. A gradient-index microlens focuses light onto a sample and collects reflected light. We use the probe interferometer to measure surface profiles of the compound eye of a housefly (Musca domestica) and measure nanometer-scale vibrations in a test sample.

  5. Vibrational Infrared Lifetime of the Anesthetic nitrous oxide gas in solution

    CERN Document Server

    Chieffo, Logan; Shattuck, Jeffrey; Hong, Mi K; Ziegler, Lawrence; Erramilli, Shyamsunder


    The lifetime of the asymmetric fundamental stretching 2218 cm$^{-1}$ vibration of the anesthetic gas nitrous oxide (N$_2$O) dissolved in octanol and olive oil is reported. These solvents are model systems commonly used to assess anesthetic potency. Picosecond time-scale molecular dynamics simulations have suggested that protein dynamics or membrane dynamics play a role in the molecular mechanism of anesthetic action. Ultrafast infrared spectroscopy with 100 fs time resolution is an ideal tool to probe dynamics of anesthetic molecules on such timescales. Pump-probe studies at the peak of the vibrational band yield a lifetime of $55 \\pm 1$ ps in olive oil and $52 \\pm 1 ps$ in octanol. The similarity of lifetimes suggests that energy relaxation of the anesthetic is determined primarily by the hydrophobic nature of the environment, consistent with models of anesthetic action. The results show that nitrous oxide is a good model system for probing anesthetic-solvent interactions using nonlinear infrared spectroscop...

  6. Vibration transmissibility characteristics of smart spring vibration isolation system

    Institute of Scientific and Technical Information of China (English)

    倪德; 朱如鹏; 陆凤霞; 鲍和云; 付秋菊


    The objective of this work was to study the vibration transmissibility characteristics of the undamped and damped smart spring systems. The frequency response characteristics of them were analyzed by using the equivalent linearization technique, and the possible types of the system motion were distinguished by using the starting and ending frequencies. The influences of system parameters on the vibration transmissibility characteristics were discussed. The following conclusions may be drawn from the analysis results. The undamped smart spring system may simultaneously have one starting frequency and one ending frequency or only have one starting frequency, and the damped system may simultaneously have two starting frequencies and one ending frequency. There is an optimal control parameter to make the peak value of the vibration transmissibility curve of the system be minimum. When the mass ratio is far away from the stiffness ratio, the vibration transmissibility is small. The effect of the damping ratio on the system vibration transmissibility is significant while the control parameter is less than its optimal value. But the influence of the relative damping ratio on the vibration transmissibility is small.

  7. Design and synthesis of fluorescent and biotin tagged probes for the study of molecular actions of FAF1 inhibitor. (United States)

    Yoo, Sung-eun; Yu, Changsun; Jung, SeoHee; Kim, Eunhee; Kang, Nam Sook


    To study the molecular action of ischemic Fas-mediated cell death inhibitor, we prepared fluorescent-tagged and biotin-tagged probes of the potent inhibitor, KR-33494, of ischemic cell death. We used the molecular modeling technique to find the proper position for attaching those probes with minimum interference in the binding process of probes with Fas-mediated cell death target, FAF1.

  8. Surface-attachment sequence in Vibrio Cholerae (United States)

    Utada, Andrew; Gibiansky, Maxsim; Wong, Gerard


    Vibrio cholerae is a gram-negative bacterium that causes the human disease cholera. It is found natively in brackish costal waters in temperate climates, where it attaches to the surfaces of a variety of different aquatic life. V. cholerae has a single polar flagellum making it highly motile, as well as a number of different pili types, enabling it to attach to both biotic and abiotic surfaces. Using in-house built tracking software we track all surface-attaching bacteria from high-speed movies to examine the early-time attachment profile of v. cholerae onto a smooth glass surface. Similar to previous work, we observe right-handed circular swimming trajectories near surfaces; however, in addition we see a host of distinct motility mechanisms that enable rapid exploration of the surface before forming a more permanent attachment. Using isogenic mutants we show that the motility mechanisms observed are due to a complex combination of hydrodynamics and pili-surface interactions. Lauga, E., DiLuzio, W. R., Whitesides, G. M., Stone, H. A. Biophys. J. 90, 400 (2006).

  9. Mother-infant attachment in adoptive families. (United States)

    Singer, L M; Brodzinsky, D M; Ramsay, D; Steir, M; Waters, E


    Data from 2 separate samples using the Strange Situation paradigm were combined to assess the quality of attachment relationships in adoptive and nonadoptive mother-infant pairs. Infants were between 13 and 18 months at the time of observation. Results indicated no differences in mother-infant attachment between nonadopted and intraracial adopted subjects or between intraracial and interracial adopted subjects. Interracial adoptive mother-infant pairs did show a higher incidence of insecure attachment in comparison to nonadoptive pairs. Mothers of interracial adopted infants also were less comfortable having others care for their babies and perceived less emotional support from extended family and friends for their decision to adopt a child prior to the actual adoption than did other mothers. No relation was found, however, between quality of mother-infant attachment and either perceived social support, infant developmental quotient, infant temperament, number of foster homes experienced by the infant, or infant's age at the time of adoption placement. It was suggested that the higher incidence of psychological problems found among adoptees in middle childhood and adolescence cannot be explained in terms of insecure attachment relationships during the infancy years.

  10. Parental incarceration, attachment and child psychopathology. (United States)

    Murray, Joseph; Murray, Lynne


    Theory and evidence relating parental incarceration, attachment, and psychopathology are reviewed. Parental incarceration is a strong risk factor for long-lasting psychopathology, including antisocial and internalizing outcomes. Parental incarceration might threaten children's attachment security because of parent-child separation, confusing communication about parental absence, restricted contact with incarcerated parents, and unstable caregiving arrangements. Parental incarceration can also cause economic strain, reduced supervision, stigma, home and school moves, and other negative life events for children. Thus, there are multiple possible mechanisms whereby parental incarceration might increase risk for child psychopathology. Maternal incarceration tends to cause more disruption for children than paternal incarceration and may lead to greater risk for insecure attachment and psychopathology. Children's prior attachment relations and other life experiences are likely to be of great importance for understanding children's reactions to parental incarceration. Several hypotheses are presented about how prior insecure attachment and social adversity might interact with parental incarceration and contribute to psychopathology. Carefully designed longitudinal studies, randomized controlled trials, and cross-national comparative research are required to test these hypotheses.

  11. Ultrafast time-resolved pump-probe spectroscopy of PYP by a sub-8 fs pulse laser at 400 nm. (United States)

    Liu, Jun; Yabushita, Atsushi; Taniguchi, Seiji; Chosrowjan, Haik; Imamoto, Yasushi; Sueda, Keiichi; Miyanaga, Noriaki; Kobayashi, Takayoshi


    Impulsive excitation of molecular vibration is known to induce wave packets in both the ground state and excited state. Here, the ultrafast dynamics of PYP was studied by pump-probe spectroscopy using a sub-8 fs pulse laser at 400 nm. The broadband spectrum of the UV pulse allowed us to detect the pump-probe signal covering 360-440 nm. The dependence of the vibrational phase of the vibrational mode around 1155 cm(-1) on the probe photon energy was observed for the first time to our knowledge. The vibrational mode coupled to the electronic transition observed in the probe spectral ranges of 2.95-3.05 and 3.15-3.35 eV was attributed to the wave packets in the ground state and the excited state, respectively. The frequencies in the ground state and excited state were determined to be 1155 ± 1 and 1149 ± 1 cm(-1), respectively. The frequency difference is due to change after photoexcitation. This means a reduction of the bond strength associated with π-π* excitation, which is related to the molecular structure change associated with the primary isomerization process in the photocycle in PYP. Real-time vibrational modes at low frequency around 138, 179, 203, 260, and 317 cm(-1) were also observed and compared with the Raman spectrum for the assignment of the vibrational wave packet.

  12. Hard probes 2006 Asilomar

    CERN Multimedia


    "The second international conference on hard and electromagnetic probes of high-energy nuclear collisions was held June 9 to 16, 2006 at the Asilomar Conference grounds in Pacific Grove, California" (photo and 1/2 page)

  13. An Ultrasonographic Periodontal Probe (United States)

    Bertoncini, C. A.; Hinders, M. K.


    Periodontal disease, commonly known as gum disease, affects millions of people. The current method of detecting periodontal pocket depth is painful, invasive, and inaccurate. As an alternative to manual probing, an ultrasonographic periodontal probe is being developed to use ultrasound echo waveforms to measure periodontal pocket depth, which is the main measure of periodontal disease. Wavelet transforms and pattern classification techniques are implemented in artificial intelligence routines that can automatically detect pocket depth. The main pattern classification technique used here, called a binary classification algorithm, compares test objects with only two possible pocket depth measurements at a time and relies on dimensionality reduction for the final determination. This method correctly identifies up to 90% of the ultrasonographic probe measurements within the manual probe's tolerance.

  14. Attachment of human primary osteoblast cells to modified polyethylene surfaces. (United States)

    Poulsson, Alexandra H C; Mitchell, Stephen A; Davidson, Marcus R; Johnstone, Alan J; Emmison, Neil; Bradley, Robert H


    Ultra-high-molecular-weight polyethylene (UHMWPE) has a long history of use in medical devices, primarily for articulating surfaces due to its inherent low surface energy which limits tissue integration. To widen the applications of UHMWPE, the surface energy can be increased. The increase in surface energy would improve the adsorption of proteins and attachment of cells to allow tissue integration, thereby allowing UHMWPE to potentially be used for a wider range of implants. The attachment and function of human primary osteoblast-like (HOB) cells to surfaces of UHMWPE with various levels of incorporated surface oxygen have been investigated. The surface modification of the UHMWPE was produced by exposure to a UV/ozone treatment. The resulting surface chemistry was studied using X-ray photoelectron spectroscopy (XPS), and the topography and surface structure were probed by atomic force microscopy (AFM) and scanning electron microscopy (SEM), which showed an increase in surface oxygen from 11 to 26 atom % with no significant change to the surface topography. The absolute root mean square roughness of both untreated and UV/ozone-treated surfaces was within 350-450 nm, and the water contact angles decreased with increasing oxygen incorporation, i.e., showing an increase in surface hydrophilicity. Cell attachment and functionality were assessed over a 21 day period for each cell-surface combination studied; these were performed using SEM and the alamarBlue assay to study cell attachment and proliferation and energy-dispersive X-ray (EDX) analysis to confirm extracellular mineral deposits, and total protein assay to examine the intra- and extracellular protein expressed by the cells. HOB cells cultured for 21 days on the modified UHMWPE surfaces with 19 and 26 atom % oxygen incorporated showed significantly higher cell densities compared to cells cultured on tissue culture polystyrene (TCPS) from day 3 onward. This indicated that the cells attached and proliferated more

  15. Vibration interaction in a multiple flywheel system (United States)

    Firth, Jordan; Black, Jonathan


    This paper investigates vibration interaction in a multiple flywheel system. Flywheels can be used for kinetic energy storage in a satellite Integrated Power and Attitude Control System (IPACS). One hitherto unstudied problem with IPACS is vibration interaction between multiple unbalanced wheels. This paper uses a linear state-space dynamics model to study the impact of vibration interaction. Specifically, imbalance-induced vibration inputs in one flywheel rotor are used to cause a resonant whirling vibration in another rotor. Extra-synchronous resonant vibrations are shown to exist, but with damping modeled the effect is minimal. Vibration is most severe when both rotors are spinning in the same direction.

  16. Vibration insensitive optical ring cavity

    Institute of Scientific and Technical Information of China (English)

    Miao Jin; Jiang Yan-Yi; Fang Su; Bi Zhi-Yi; Ma Long-Sheng


    The mounting configuration of an optical ring cavity is optimized for vibration insensitivity by finite element analysis. A minimum response to vertical accelerations is found by simulations made for different supporting positions.

  17. Childhood Sexual Abuse, Attachment, and Trauma Symptoms in College Females: The Moderating Role of Attachment (United States)

    Aspelmeier, Jeffery E.; Elliott, Ann N.; Smith, Christopher H.


    Objective: The present study tests a model linking attachment, childhood sexual abuse (CSA), and adult psychological functioning. It expands on previous work by assessing the degree to which attachment security moderates the relationship between a history of child sexual abuse and trauma-related symptoms in college females. Method: Self-reports of…

  18. The Secure-Base Hypothesis: Global Attachment, Attachment to Counselor, and Session Exploration in Psychotherapy (United States)

    Romano, Vera; Fitzpatrick, Marilyn; Janzen, Jennifer


    This study explored J. Bowlby's (1988) secure-base hypothesis, which predicts that a client's secure attachment to the therapist, as well as the client's and the therapist's global attachment security, will facilitate in-session exploration. Volunteer clients (N = 59) and trainee counselors (N = 59) in short-term therapy completed the Experiences…

  19. Parent Attachment, Childrearing Behavior, and Child Attachment: Mediated Effects Predicting Preschoolers' Externalizing Behavior (United States)

    Roskam, Isabelle; Meunier, Jean-Christophe; Stievenart, Marie


    Attachment theory provides an interesting background for thinking about externalizing behavior (EB) in early childhood and for understanding how parenting influences the child's outcomes. The study examined how attachment and parenting could be combined to explain preschoolers' EB. Data were collected from 117 preschoolers aged from 4 to 6…

  20. Modified relaxation dynamics and coherent energy exchange in coupled vibration-cavity polaritons (United States)

    Dunkelberger, A. D.; Spann, B. T.; Fears, K. P.; Simpkins, B. S.; Owrutsky, J. C.


    Coupling vibrational transitions to resonant optical modes creates vibrational polaritons shifted from the uncoupled molecular resonances and provides a convenient way to modify the energetics of molecular vibrations. This approach is a viable method to explore controlling chemical reactivity. In this work, we report pump-probe infrared spectroscopy of the cavity-coupled C-O stretching band of W(CO)6 and the direct measurement of the lifetime of a vibration-cavity polariton. The upper polariton relaxes 10 times more quickly than the uncoupled vibrational mode. Tuning the polariton energy changes the polariton transient spectra and relaxation times. We also observe quantum beats, so-called vacuum Rabi oscillations, between the upper and lower vibration-cavity polaritons. In addition to establishing that coupling to an optical cavity modifies the energy-transfer dynamics of the coupled molecules, this work points out the possibility of systematic and predictive modification of the excited-state kinetics of vibration-cavity polariton systems.

  1. Attachment theory: a biological basis for psychotherapy? (United States)

    Holmes, J


    John Bowlby bemoaned the separation between the biological and psychological approaches in psychiatry, and hoped that attachment theory, which brings together psychoanalysis and the science of ethology, would help bridge the rift between them. Recent findings in developmental psychology have delineated features of parent-infant interaction, especially responsiveness, attunement, and modulation of affect, which lead to either secure or insecure attachment. Similar principles can be applied to the relationship between psychotherapist and patient--the provision of a secure base, the emergence of a shared narrative ('autobiographical competence'), the processing of affect, coping with loss--these are common to most effective psychotherapies and provide the basis for a new interpersonal paradigm within psychotherapy. Attachment theory suggests they rest on a sound ethological and hence biological foundation.

  2. [Attachment and Adoption: Diagnostics, Psychopathology, and Therapy]. (United States)

    Brisch, Karl-Heinz


    This presentation describes the development of attachment between adopted children and their adoptive parents with a focus on the particular issues seen in international adoptions. The questions of settling in, trauma in the country of origin, and the motivations of the adoptive parents will be discussed. Diagnosis and various psychopathological manifestations will be examined, as will outpatient and inpatient modes of therapy. The treatment of children of various ages will be covered along with the necessity for intensive counseling and psychotherapy for the adoptive parents. This will enable the parents to work through early trauma, which will give them and their adopted child the basis for developing healthy attachment patterns. This in turn will enable the child to mature and integrate into society. Possibilities of prevention are discussed. Many of the approaches discussed here regarding attachment and adoption may be applied to foster children and their foster parents.

  3. [ADHD and attachment processes: are they related?]. (United States)

    Franc, N; Maury, M; Purper-Ouakil, D


    Attention-deficit/hyperactivity disorder (ADHD) is defined on the basis of developmentally inappropriate inattention, motor activity and impulsivity that emerges early in development and causes impairment in social and academic functioning. ADHD is described as a multifactorial disease, with a well studied genetic vulnerability, and early environmental factors also playing an important role in the development and course of the disorder. Current aetiological models emphasize interaction between genes and environment. The concept of attachment, as proposed by John Bowlby, reflects quality of early interactions, and should therefore be considered as an early developmental factor. First, clinical findings emphasize similitude between both disorders; emotional dysregulation is an important feature in reactive attachment disorder as well as in ADHD. Emotion regulation is highly related to attachment security in young children and could play a part in the development of early attention processes. Moreover, difficult temperament is associated with higher risk for ADHD on the one hand, and can disturb the process of attachment on the other. Parental caregiving - including maternal sensitivity, positive parenting practices - is a main factor involved in the development of attachment, and has shown to be associated with better outcomes in ADHD children, especially with less oppositional/conduct disorders. Second, the aim of our review is to present clinical studies that have looked for a link between ADHD and attachment: the type of attachment could play a part in the course of the disorder: insecure and disorganised attachment types tend to be associated with a higher risk of externalised behaviors in children. For ADHD, this effect seems to be weaker than for other externalised disorders, and has been shown only in populations of at-risk children. Clinical studies also raise the question of possible links between reactive attachment disorder and ADHD. In children suffering

  4. Attachment relationships as determinants of physical health. (United States)

    Maunder, Robert G; Hunter, Jonathan J


    Childhood adversity alters the relational world of the child and inhibits the development of secure attachment bonds. The purpose of this article is to survey recent evidence that attachment insecurity has the potential to impair physical health throughout the lifespan. It is proposed that attachment insecurity contributes to disease risk through a range of mechanisms which include (1) disturbances in arousal and recovery within physiological systems that respond to stress; (2) physiological links between the mediators of social relationships, stress, and immunity; (3) links between relationship style and various health behaviors; and (4) disease risk factors that serve as external regulators of dysphoric affect, such as nicotine and alcohol. The evidence for these mechanisms, particularly the evidence that has accumulated since the model was first proposed in 2000, is presented and discussed.

  5. Harmonic vibrations of multispan beams

    DEFF Research Database (Denmark)

    Dyrbye, Claes


    Free and forced harmonic vibrations of multispan beams are determined by a method which implies 1 equation regardless of the configuration. The necessary formulas are given in the paper. For beams with simple supports and the same length of all (n) spans, there is a rather big difference between...... the n´th and the (n+1)´th eigenfrequency. The reason for this phenomenon is explained.Keywords: Vibrations, Eigenfrequencies, Beams....

  6. Vibration Theory, Vol. 1B

    DEFF Research Database (Denmark)

    Asmussen, J. C.; Nielsen, Søren R. K.

    The present collection of MATLAB exercises has been published as a supplement to the textbook, Svingningsteori, Bind 1 and the collection of exercises in Vibration theory, Vol. 1A, Solved Problems. Throughout the exercise references are made to these books. The purpose of the MATLAB exercises is ...... is to give a better understanding of the physical problems in linear vibration theory and to surpress the mathematical analysis used to solve the problems. For this purpose the MATLAB environment is excellent....

  7. Semiactive control for vibration attenuation

    Energy Technology Data Exchange (ETDEWEB)

    Leitmann, G. [Univ. of California, Berkeley, CA (United States). Coll. of Engineering


    With the advent of materials, such as electrorheological fluids, whose material properties can be altered rapidly by means of external stimuli, employing such materials as actuators for the controlled attenuation of undesirable vibrations is now possible. Such control schemes are dubbed semiactive in that they attenuate vibrations whether applied actively or passively. The author investigates various such control schemes, allowing for both separate and joint control of the stiffness and damping characteristics of the material.

  8. C-130J Human Vibration (United States)


    during an attack of blanching (Griffin, 1990; Wasserman, 1987). Bone and joint disorders (e.g., osteoarthritis, degeneration or deformity of bones of...1756 4 vibrate in the range of 8 to 1000 Hz (Griffin, 1990). Local vibration has been associated with circulatory disorders, bone and joint ... disorders , neurological disorders, muscle disorders and other general disorders (e.g., central nervous system) (Griffin, 1990). The most prominent

  9. Free vibration investigation of nano mass sensor using differential transformation method (United States)

    Zarepour, Misagh; Hosseini, S. Amirhosein; Ghadiri, Majid


    In the present study, transverse vibration of nano-cantilever beam with attached mass and two rotational and transverse springs at its end is studied. Resonance frequency of vibrating system is influenced by changing mass particle and stiffness coefficients. Euler-Bernoulli beam theory, nonlocal constitutive equations of Eringen, and Hamilton's principle are used to develop equations of motion. Differential transformation method (DTM) is applied to solve the governing equations of the nanobeam with attached mass particle. Accurate results with minimum mathematical calculation are the advantages of DTM. A detailed parametric study is conducted to investigate the influences of nonlocal parameter. The results can be used in designing of nanoelectromechanical systems. To verify the results, some comparisons are presented between differential transform method results and open literature to show the accuracy of this new approach.

  10. Simulating Displacement and Velocity Signals by Piezoelectric Sensor in Vibration Control Applications

    Directory of Open Access Journals (Sweden)

    G. J. Sheu


    Full Text Available Intelligent structures with built-in piezoelectric sensor and actuator that can actively change their physical geometry and/or properties have been known preferable in vibration control. However, it is often arguable to determine if measurement of piezoelectric sensor is strain rate, displacement, or velocity signal. This paper presents a neural sensor design to simulate the sensor dynamics. An artificial neural network with error backpropagation algorithm is developed such that the embedded and attached piezoelectric sensor can faithfully measure the displacement and velocity without any signal conditioning circuitry. Experimental verification shows that the neural sensor is effective to vibration suppression of a smart structure by embedded sensor/actuator and a building structure by surface-attached piezoelectric sensor and active mass damper.

  11. Aircraft vibration and flutter

    Directory of Open Access Journals (Sweden)

    R. R. Aggarwal


    Full Text Available "The paper outlines the theoretical and experimental procedure one has to adopt for flutter prevention during the various stages (project, design and prototype of the development of modern aircraft. With the advent of high speed, the aerodynamic coefficients have to be calculated with due regards to the effects of compressibility, finite aspect ratio of the lifting surfaces, sweep back and other peculiar shapes of the wings. The use of thin, small aspect ratio with external masses, necessitates the computation of higher frequency modes of vibration. Single degree of freedom flutter and the effect of control surface non-linearities has also become very important. Thus, it is shown how the availability of high speed computing machines, improved experimental technique for model and full scale testing has not kept pace with the uncertainties associated with the transonic speeds, low aspect ratio and the high frequency modes. Cross-checking of theoretical and experimental results at every stage seem to be the only answer."

  12. Family systems theory, attachment theory, and culture. (United States)

    Rothbaum, Fred; Rosen, Karen; Ujiie, Tatsuo; Uchida, Nobuko


    Family systems theory and attachment theory have important similarities and complementarities. Here we consider two areas in which the theories converge: (a) in family system theorists' description of an overly close, or "enmeshed," mother-child dyad, which attachment theorists conceptualize as the interaction of children's ambivalent attachment and mothers' preoccupied attachment; (b) in family system theorists' description of the "pursuer-distance cycle" of marital conflict, which attachment theorists conceptualize as the interaction of preoccupied and dismissive partners. We briefly review family systems theory evidence, and more extensively review attachment theory evidence, pertaining to these points of convergence. We also review cross-cultural research, which leads us to conclude that the dynamics described in both theories reflect, in part, Western ways of thinking and Western patterns of relatedness. Evidence from Japan suggests that extremely close ties between mother and child are perceived as adaptive, and are more common, and that children experience less adverse effects from such relationships than do children in the West. Moreover, in Japan there is less emphasis on the importance of the exclusive spousal relationship, and less need for the mother and father to find time alone to rekindle romantic, intimate feelings and to resolve conflicts by openly communicating their differences. Thus, the "maladaptive" pattern frequently cited by Western theorists of an extremely close mother-child relationship, an unromantic, conflictual marriage characterized by little verbal communication and a peripheral, distant father, may function very differently in other cultures. While we believe that both theories will be greatly enriched by their integration, we caution against the application of either theory outside the cultures in which they were developed.

  13. VESPA: The vibrational spectrometer for the European Spallation Source (United States)

    Fedrigo, Anna; Colognesi, Daniele; Bertelsen, Mads; Hartl, Monika; Lefmann, Kim; Deen, Pascale P.; Strobl, Markus; Grazzi, Francesco; Zoppi, Marco


    VESPA, Vibrational Excitation Spectrometer with Pyrolytic-graphite Analysers, aims to probe molecular excitations via inelastic neutron scattering. It is a thermal high resolution inverted geometry time-of-flight instrument designed to maximise the use of the long pulse of the European Spallation Source. The wavelength frame multiplication technique was applied to provide simultaneously a broad dynamic range (about 0-500 meV) while a system of optical blind choppers allows to trade flux for energy resolution. Thanks to its high flux, VESPA will allow the investigation of dynamical and in situ experiments in physical chemistry. Here we describe the design parameters and the corresponding McStas simulations.

  14. Effect of attachment strategies on bipartite networks

    DEFF Research Database (Denmark)

    Ganguly, N.; Saha, S.; Maiti, A.;


    rate. Here, we focus on the case where one of the partitions can be assumed to be fixed while the other partition grows in time as observed in the codon-gene or alphabet-word network. We show that subtle changes in growth dynamics, particularly in the attachment kernel, can lead to drastic changes...... of the emergent topological properties. We present a detail analysis of various growth strategies, including sequential and parallel addition of nodes, as well as with and without replacement attachment kernels. Analytical results have been compared with stochastic simulations as well as with real systems showing...

  15. The Child Attachment Interview: A Narrative Review (United States)

    Privizzini, Antonella


    Attachment theory promoted an impressive body of research on the psychic developmental processes, resulting in studies on both typical and atypical development. Much of the diffusion of the attachment theory in the clinical field was related to the design of reliable instruments to evaluate the organization of attachment in infancy as well as in adulthood. Until recently, the lack of a suitable instrument to assess attachment in middle childhood as well as in adolescence hindered the expansion of research in these developmental phases during which the parent-child relationship takes on a different, albeit still crucial, role. The Child Attachment Interview (CAI), a measure that was recently designed to assess attachment at a representational level in middle childhood and adolescence, filled the measurement gap. The aim of the current review was to summarize previous empirical investigations concerning CAI in order to (a) provide an overview of the state of current research, (b) identify unanswered questions, and (c) propose future research directions. A narrative review was conducted to map the current research findings by searching for the term “Child Attachment Interview” in the Medline, Scopus, Web of Science, and PsychINFO databases, followed by a search in Mendeley. Limits were set to exclude dissertations, chapters in books, and qualitative or theoretical papers, while empirical studies were included if they used the CAI and were published in English language, peer-reviewed journals by July, 2016. The review, which ultimately included 39 studies meeting the criteria, showed that the CAI is a reliable instrument to assess attachment organization in clinical and non-clinical samples, thus providing a worthwhile contribution to the investigation of the influence of the parent-child relationship beyond infancy and early childhood. Nevertheless, the review pointed out a number of relevant open issues, the most critical of which concerned the CAI coding and

  16. Attachment of Salmonella spp. to pork meat

    DEFF Research Database (Denmark)

    Hansen, Trine; Riber, Leise; Löfström, Charlotta;


    Five strains of Salmonella, one wildtype and four knock-out mutants (the prg, flhDC, yhjH and fliC genes) were investigated based on their probability to attach and subsequently detach from a surface of pork fillet. The attachment followed by detachment was measured and modelled for two different...... contact times using cells coming from either a planktonic or an immobilized state of growth. The results showed that the probability of detachment generally decreased when the contact time increased and that the highest difference between contact times was achieved when the cells were grown planktonic....

  17. Adult Attachment Style, Hardiness, and Mood (United States)


    Separated 72 5.6 Divorced 76 5.9 Widowed 3 0.2 ADULT ATTACHMENT STYLE, HARDINESS, AND MOOD 131 D ow nl oa de d by [ Pa ul T . B ar to ne ] at 1 2: 35...Kobak, R. R., & Sceery, A. (1988). Attachment in late adolescence : Work- ing models, affect regulation, and representations of self and others. Child...Reassessing the dimensions of tem- peramental individuality across the lifespan: The revised dimensions of temperament survey (DOTS-R). Journal of Adolescent

  18. The Child Attachment Interview: A Narrative Review. (United States)

    Privizzini, Antonella


    Attachment theory promoted an impressive body of research on the psychic developmental processes, resulting in studies on both typical and atypical development. Much of the diffusion of the attachment theory in the clinical field was related to the design of reliable instruments to evaluate the organization of attachment in infancy as well as in adulthood. Until recently, the lack of a suitable instrument to assess attachment in middle childhood as well as in adolescence hindered the expansion of research in these developmental phases during which the parent-child relationship takes on a different, albeit still crucial, role. The Child Attachment Interview (CAI), a measure that was recently designed to assess attachment at a representational level in middle childhood and adolescence, filled the measurement gap. The aim of the current review was to summarize previous empirical investigations concerning CAI in order to (a) provide an overview of the state of current research, (b) identify unanswered questions, and (c) propose future research directions. A narrative review was conducted to map the current research findings by searching for the term "Child Attachment Interview" in the Medline, Scopus, Web of Science, and PsychINFO databases, followed by a search in Mendeley. Limits were set to exclude dissertations, chapters in books, and qualitative or theoretical papers, while empirical studies were included if they used the CAI and were published in English language, peer-reviewed journals by July, 2016. The review, which ultimately included 39 studies meeting the criteria, showed that the CAI is a reliable instrument to assess attachment organization in clinical and non-clinical samples, thus providing a worthwhile contribution to the investigation of the influence of the parent-child relationship beyond infancy and early childhood. Nevertheless, the review pointed out a number of relevant open issues, the most critical of which concerned the CAI coding and

  19. Assortativity in generalized preferential attachment models

    CERN Document Server

    Krot, Alexander


    In this paper, we analyze assortativity of preferential attachment models. We deal with a wide class of preferential attachment models (PA-class). It was previously shown that the degree distribution in all models of the PA-class follows a power law. Also, the global and the average local clustering coefficients were analyzed. We expand these results by analyzing the assortativity property of the PA-class of models. Namely, we analyze the behavior of $d_{nn}(d)$ which is the average degree of a neighbor of a vertex of degree $d$.

  20. Effects of Emotion Regulation Training on Attachment Style of Primiparous Pregnant Women with Insecure Attachment

    Directory of Open Access Journals (Sweden)

    Tayebeh Reyhani


    Full Text Available Background: Pregnant women with insecure attachment style are at high risk of psychiatric disorders. Since emotions are the first coordinators of attachment behavior, emotion regulation training can alter maternal attachment style. In this study, we aimed to evaluate the effects of emotion regulation training on the attachment styles of primiparous pregnant women with insecure attachment style. Aim: This study aimed to evaluate the effects of training programs on the headache of patients after spinal anesthesia. Method: This randomized, clinical trial on 40 primiparous pregnant women with age range of 30-34 years, who were referred to healthcare centers of Mashhad, Iran, during 2014. The data collection instrument was Revised Adult Attachment Scale (RAAS. The participants were assigned to intervention and control groups. A training program was implemented on emotion regulation based on dialectical behavior therapy (DBT for the intervention group. After delivery, RAAS was completed by the mothers again. The control group only received the routine care. To analyze the data, Chi-square and independent t-test were run using SPSS, version 15. Results: Mean ages of the mothers in the intervention and control groups were 26.9±4.04 and 27.5±3.5 years, respectively. According to the results of independent t-test, the difference between the groups was non-significant (P=0.77. The groups were analogous in terms of attachment style pre-intervention. After the intervention, independent t-test did not reflect any significant differences between the groups regarding avoidant (P=0.37 and anxious (P=0.11 attachment styles. However, mean score for secure attachment style was significantly enhanced (P=0.01. Implications for Practice: Our findings revealed that implementation of emotion regulation training increased secure attachment scores. Thus, implementing emotion regulation training program is recommended as part of a program for pre-natal care in healthcare

  1. Design and Calibration Tests of an Active Sound Intensity Probe

    Directory of Open Access Journals (Sweden)

    Thomas Kletschkowski


    Full Text Available The paper presents an active sound intensity probe that can be used for sound source localization in standing wave fields. The probe consists of a sound hard tube that is terminated by a loudspeaker and an integrated pair of microphones. The microphones are used to decompose the standing wave field inside the tube into its incident and reflected part. The latter is cancelled by an adaptive controller that calculates proper driving signals for the loudspeaker. If the open end of the actively controlled tube is placed close to a vibrating surface, the radiated sound intensity can be determined by measuring the cross spectral density between the two microphones. A one-dimensional free field can be realized effectively, as first experiments performed on a simplified test bed have shown. Further tests proved that a prototype of the novel sound intensity probe can be calibrated.

  2. Attachment and the Processing of Social Information in Adolescence (United States)

    Dykas, Matthew J.; Cassidy, Jude


    A key proposition of attachment theory is that experience-based cognitive representations of attachment, often referred to as internal working models of attachment, influence the manner in which individuals process attachment-relevant social information (Bowlby, 1969/1982, 1973, 1980; Bretherton & Munholland, 1999; Main, Kaplan, & Cassidy, 1985).…

  3. Attachment Disorder: An Emerging Concern for School Counselors. (United States)

    Parker, Kandis Cooke; Forrest, Donald


    Explains attachment theory and posits that, if proper bonding and subsequent attachment, usually between mother and child, does not occur, the child develops mistrust and deep-seated rage. Presents evidence of the problem of attachment disorders, lists symptoms of unattached children, examines treatment of attachment disorders, and discusses…

  4. Role of Attachment in Response to Pet Loss (United States)

    Field, Nigel P.; Orsini, Lisa; Gavish, Roni; Packman, Wendy


    This study examined the impact of attachment on grief severity following the death of a pet. Seventy-one participants who had lost a dog or cat within the past year completed a set of measures that included an attachment measure assessing individual differences in attachment anxiety and avoidance, strength of the past attachment to the pet, the…

  5. 30 CFR 56.19026 - Drum end attachment. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drum end attachment. 56.19026 Section 56.19026... Ropes § 56.19026 Drum end attachment. (a) For drum end attachment, wire rope shall be attached— (1... bolts, clamps, or wedges, provided that the attachment is a design feature of the hoist drum....

  6. 30 CFR 75.1436 - Drum end attachment. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drum end attachment. 75.1436 Section 75.1436... attachment. (a) For drum end attachment, wire rope shall be attached— (1) Securely by clips after making one... that the attachment is a design feature of the hoist drum. Design feature means either the...

  7. 30 CFR 57.19026 - Drum end attachment. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drum end attachment. 57.19026 Section 57.19026... Wire Ropes § 57.19026 Drum end attachment. (a) For drum end attachment, wire rope shall be attached— (1... bolts, clamps, or wedges, provided that the attachment is a design feature of the hoist drum....

  8. Electron impact cross sections of vibrationally and electronically excited molecules

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jung-Sik, E-mail: [Plasma Technology Research Center, National Fusion Research Institute, 814-2, Osikdo-Dong, Gunsan, Jeollabuk-Do, 573-540 (Korea, Republic of); Song, Mi-Young; Kwon, Deuk-Chul; Choi, Heechol [Plasma Technology Research Center, National Fusion Research Institute, 814-2, Osikdo-Dong, Gunsan, Jeollabuk-Do, 573-540 (Korea, Republic of); Kim, Chang-Geun [National Center for Standard Reference Data, Korea Research Institute of Standards and Science, Doryong-Dong, Yuseong-Gu, Daejeon 305-340 (Korea, Republic of); Kumar, Vijay [B-82, Aarohi Twin Bungalows, Near Govt. Tubewell, Bopal, Ahmedabad-380058 (India)


    It is well known that the electron impact cross sections for elastic and inelastic processes for the vibrationally and electronically excited molecules are predominantly different than those for molecules in the ground state. Collisions of low energy electrons with excited molecules play an important role in explaining the behavior of gas discharges in laser and plasma physics, in planetary atmospheres, stars, and interstellar medium and in plasmas widely used in the fabrication of microelectronics. This explains as to why there is a need for having validated sets of electron impact cross sections for different processes. This work reviews the subject of electron collisions with vibrationally and electronically excited molecules in a comprehensive way. The survey has been carried out for a few excited molecules such as H{sub 2}, D{sub 2}, T{sub 2}, HD, HT, DT, N{sub 2}, O{sub 2}, and CO{sub 2}. This review includes the discussion on the methods to produce and detect vibrationally and electronically excited molecules. We will take up the cross section data available in the literature for such molecules on electron scattering, dissociation, ionization and attachment processes and will discuss, evaluate and well-validate the same wherever and whenever possible.

  9. Experimental investigation of jet pulse control on flexible vibrating structures (United States)

    Karaiskos, Grigorios; Papanicolaou, Panos; Zacharopoulos, Dimitrios


    The feasibility of applying on-line fluid jet pulses to actively control the vibrations of flexible structures subjected to harmonic and earthquake-like base excitations provided by a shake table is explored. The operating principles and capabilities of the control system applied have been investigated in a simplified small-scale laboratory model that is a mass attached at the top free end of a vertical flexible slender beam with rectangular cross-section, the other end of which is mounted on an electrodynamic shaker. A pair of opposite jets placed on the mass at the top of the cantilever beam applied the appropriate forces by ejecting pressurized air pulses controlled by on/off solenoid electro-valves via in house developed control software, in order to control the vibration caused by harmonic, periodic and random excitations at pre-selected frequency content provided by the shaker. The dynamics of the structure was monitored by accelerometers and the jet impulses by pressure sensors. The experimental results have demonstrated the effectiveness and reliability of Jet Pulse Control Systems (JPCS). It was verified that the measured root mean square (RMS) vibration levels of the controlled structure from harmonic and earthquake base excitations, could be reduced by approximately 50% and 33% respectively.

  10. Application of a load-bearing passive and active vibration isolation system in hydraulic drives (United States)

    Unruh, Oliver; Haase, Thomas; Pohl, Martin


    Hydraulic drives are widely used in many engineering applications due to their high power to weight ratio. The high power output of the hydraulic drives produces high static and dynamic reaction forces and moments which must be carried by the mounts and the surrounding structure. A drawback of hydraulic drives based on rotating pistons consists in multi-tonal disturbances which propagate through the mounts and the load bearing structure and produce structure borne sound at the surrounding structures and cavities. One possible approach to overcome this drawback is to use an optimised mounting, which combines vibration isolation in the main disturbance direction with the capability to carry the reaction forces and moments. This paper presents an experimental study, which addresses the vibration isolation performance of an optimised mounting. A dummy hydraulic drive is attached to a generic surrounding structure with optimised mounting and excited by multiple shakers. In order to improve the performance of the passive vibration isolation system, piezoelectric transducers are applied on the mounting and integrated into a feed-forward control loop. It is shown that the optimised mounting of the hydraulic drive decreases the vibration transmission to the surrounding structure by 8 dB. The presented study also reveals that the use of the active control system leads to a further decrease of vibration transmission of up to 14 dB and also allows an improvement of the vibration isolation in an additional degree of freedom and higher harmonic frequencies.

  11. Electrostatic energy harvesting device with dual resonant structure for wideband random vibration sources at low frequency (United States)

    Zhang, Yulong; Wang, Tianyang; Zhang, Ai; Peng, Zhuoteng; Luo, Dan; Chen, Rui; Wang, Fei


    In this paper, we present design and test of a broadband electrostatic energy harvester with a dual resonant structure, which consists of two cantilever-mass subsystems each with a mass attached at the free edge of a cantilever. Comparing to traditional devices with single resonant frequency, the proposed device with dual resonant structure can resonate at two frequencies. Furthermore, when one of the cantilever-masses is oscillating at resonance, the vibration amplitude is large enough to make it collide with the other mass, which provides strong mechanical coupling between the two subsystems. Therefore, this device can harvest a decent power output from vibration sources at a broad frequency range. During the measurement, continuous power output up to 6.2-9.8 μW can be achieved under external vibration amplitude of 9.3 m/s2 at a frequency range from 36.3 Hz to 48.3 Hz, which means the bandwidth of the device is about 30% of the central frequency. The broad bandwidth of the device provides a promising application for energy harvesting from the scenarios with random vibration sources. The experimental results indicate that with the dual resonant structure, the vibration-to-electricity energy conversion efficiency can be improved by 97% when an external random vibration with a low frequency filter is applied.

  12. Vibrational excitation in O2and Cl2inductively-coupled plasmas and DC discharges (United States)

    Booth, Jean-Paul; Marinov, Daniil; Foucher, Mickael; Annusova, Adriana; Guerra, Vasco


    Low-energy electrons can interact with molecules via resonances to cause vibrational excitation with large cross-sections. Such processes can absorb significant energy from the plasma electrons, affecting the electron energy distribution and potentially (via vibration-translation (VT) energy transfer) causing substantial gas heating. The presence of vibrationally excited molecules may significant increase the rates of collisional processes, including electron dissociative attachment and electron impact dissociation into neutral atoms. However, the cross-sections of these processes are often poorly known since they are extremely difficult to measure directly, and reliable theoretical calculations are only now appearing for simple diatomic molecules. We have measured the vibrational distributions in discharges in pure O2 and pure Cl2, using high-sensitivity ultra-broadband ultraviolet absorption spectroscopy. In O2 plasmas significant vibrational excitation is observed, up to v'' =18, with a tail temperature of around 8000K. In Cl2 excitation is only observed up to v'' =3, and the distribution appears to be in local equilibrium with the gas translational temperature (up to 1500K). We are developing a detailed self-consistent 0D global model of these systems including vibrational excitation. Work performed in the LABEX Plas@par project, with financial state aid (ANR-11-IDEX-0004-02 and ANR-13-BS09-0019).

  13. Adult attachment and incidental memory for emotional words

    Directory of Open Access Journals (Sweden)

    Nanxin Li


    Full Text Available A dual task of attachment priming and memory recognition was proposed to explore the effect of adult attachment styles on the incidental memory for emotional words. Subjects completed an attachment priming task which intends to activate internal working model of attachment by describing attachment-related scenes, and then an incidental memory recognition test of words which differ in emotional meaning and relevance of attachment styles. Signal detection theory was used to compare the discriminability index and decision criterion of emotional words in subjects of different attachment style. Results showed that subjects with secure attachment styles performed better than insecure-attached subjects in the memory recognition test, in terms of higher hit rate, lower false alarm rate, and higher discriminability index. We extended the influence of attachment styles on cognition to lower level of incidental memory, not just on higher cognitive level with emotional arousal as suggested by previous research.

  14. Theoretical study of radiative electron attachment to CN, C2H, and C4H radicals

    CERN Document Server

    Douguet, Nicolas; Raoult, Maurice; Dulieu, Olivier; Orel, Ann E; Kokoouline, Viatcheslav


    A first-principle theoretical approach to study the process of radiative electron attachment is developed and applied to the negative molecular ions CN$^-$, C$_4$H$^-$, and C$_2$H$^-$. Among these anions, the first two have already been observed in the interstellar space. Cross sections and rate coefficients for formation of these ions by radiative electron attachment to the corresponding neutral radicals are calculated. For completeness of the theoretical approach, two pathways for the process have been considered: (i) A direct pathway, in which the electron in collision with the molecule spontaneously emits a photon and forms a negative ion in one of the lowest vibrational levels, and (ii) an indirect, or two-step pathway, in which the electron is initially captured through non-Born-Oppenheimer coupling into a vibrationally resonant excited state of the anion, which then stabilizes by radiative decay. We develop a general model to describe the second pathway and show that its contribution to the formation o...

  15. An Attachable Electromagnetic Energy Harvester Driven Wireless Sensing System Demonstrating Milling-Processes and Cutter-Wear/Breakage-Condition Monitoring

    Directory of Open Access Journals (Sweden)

    Tien-Kan Chung


    Full Text Available An attachable electromagnetic-energy-harvester driven wireless vibration-sensing system for monitoring milling-processes and cutter-wear/breakage-conditions is demonstrated. The system includes an electromagnetic energy harvester, three single-axis Micro Electro-Mechanical Systems (MEMS accelerometers, a wireless chip module, and corresponding circuits. The harvester consisting of magnets with a coil uses electromagnetic induction to harness mechanical energy produced by the rotating spindle in milling processes and consequently convert the harnessed energy to electrical output. The electrical output is rectified by the rectification circuit to power the accelerometers and wireless chip module. The harvester, circuits, accelerometer, and wireless chip are integrated as an energy-harvester driven wireless vibration-sensing system. Therefore, this completes a self-powered wireless vibration sensing system. For system testing, a numerical-controlled machining tool with various milling processes is used. According to the test results, the system is fully self-powered and able to successfully sense vibration in the milling processes. Furthermore, by analyzing the vibration signals (i.e., through analyzing the electrical outputs of the accelerometers, criteria are successfully established for the system for real-time accurate simulations of the milling-processes and cutter-conditions (such as cutter-wear conditions and cutter-breaking occurrence. Due to these results, our approach can be applied to most milling and other machining machines in factories to realize more smart machining technologies.

  16. An Attachable Electromagnetic Energy Harvester Driven Wireless Sensing System Demonstrating Milling-Processes and Cutter-Wear/Breakage-Condition Monitoring. (United States)

    Chung, Tien-Kan; Yeh, Po-Chen; Lee, Hao; Lin, Cheng-Mao; Tseng, Chia-Yung; Lo, Wen-Tuan; Wang, Chieh-Min; Wang, Wen-Chin; Tu, Chi-Jen; Tasi, Pei-Yuan; Chang, Jui-Wen


    An attachable electromagnetic-energy-harvester driven wireless vibration-sensing system for monitoring milling-processes and cutter-wear/breakage-conditions is demonstrated. The system includes an electromagnetic energy harvester, three single-axis Micro Electro-Mechanical Systems (MEMS) accelerometers, a wireless chip module, and corresponding circuits. The harvester consisting of magnets with a coil uses electromagnetic induction to harness mechanical energy produced by the rotating spindle in milling processes and consequently convert the harnessed energy to electrical output. The electrical output is rectified by the rectification circuit to power the accelerometers and wireless chip module. The harvester, circuits, accelerometer, and wireless chip are integrated as an energy-harvester driven wireless vibration-sensing system. Therefore, this completes a self-powered wireless vibration sensing system. For system testing, a numerical-controlled machining tool with various milling processes is used. According to the test results, the system is fully self-powered and able to successfully sense vibration in the milling processes. Furthermore, by analyzing the vibration signals (i.e., through analyzing the electrical outputs of the accelerometers), criteria are successfully established for the system for real-time accurate simulations of the milling-processes and cutter-conditions (such as cutter-wear conditions and cutter-breaking occurrence). Due to these results, our approach can be applied to most milling and other machining machines in factories to realize more smart machining technologies.

  17. Tailored probes for atomic force microscopy fabricated by two-photon polymerization (United States)

    Göring, Gerald; Dietrich, Philipp-Immanuel; Blaicher, Matthias; Sharma, Swati; Korvink, Jan G.; Schimmel, Thomas; Koos, Christian; Hölscher, Hendrik


    3D direct laser writing based on two-photon polymerization is considered as a tool to fabricate tailored probes for atomic force microscopy. Tips with radii of 25 nm and arbitrary shape are attached to conventionally shaped micro-machined cantilevers. Long-term scanning measurements reveal low wear rates and demonstrate the reliability of such tips. Furthermore, we show that the resonance spectrum of the probe can be tuned for multi-frequency applications by adding rebar structures to the cantilever.

  18. Vibration Characteristics of An Offshore Platform and Its Vibration Control

    Institute of Scientific and Technical Information of China (English)

    李华军; 王树青; 杨永春; 王燕


    A template offshore platform, located in the Bohai Bay of China, has exhibited excessive, unexpected vibration un-der mildly hostile sea conditions, which has affected the normal operation of the platform. Since the structure was de-signed to sustain more severe wave climate, the cause of the excessive vibration has been suspected to originate from othersources. The main objectives of this study are to investigate the causes of the excessive vibration, and to explore possibleremedies to solve the problem. In this paper, the vibration behavior of the offshore platform is analyzed by means of finiteelement (FE) modeling, field measurements and laboratory test. Results of analysis suggest that relative movement andimpact between the piles and the jacket legs exist, i.e. the piles and the jacket are not perfectly connected. The discon-nection of the piles and jacket weakens the overall stiffness of the platform, and therefore produces unexpected excessivevibration. In this study, measures for reducing the excessive vibration are proposed to control the response of the platform .

  19. Development of a novel nanoindentation technique by utilizing a dual-probe AFM system. (United States)

    Cinar, Eyup; Sahin, Ferat; Yablon, Dalia


    A novel instrumentation approach to nanoindentation is described that exhibits improved resolution and depth sensing. The approach is based on a multi-probe scanning probe microscopy (SPM) tool that utilizes tuning-fork based probes for both indentation and depth sensing. Unlike nanoindentation experiments performed with conventional AFM systems using beam-bounce technology, this technique incorporates a second probe system with an ultra-high resolution for depth sensing. The additional second probe measures only the vertical movement of the straight indenter attached to a tuning-fork probe with a high spring constant and it can also be used for AFM scanning to obtain an accurate profiling. Nanoindentation results are demonstrated on silicon, fused silica, and Corning Eagle Glass. The results show that this new approach is viable in terms of accurately characterizing mechanical properties of materials through nanoindentation with high accuracy, and it opens doors to many other exciting applications in the field of nanomechanical characterization.

  20. Development of a novel nanoindentation technique by utilizing a dual-probe AFM system

    Directory of Open Access Journals (Sweden)

    Eyup Cinar


    Full Text Available A novel instrumentation approach to nanoindentation is described that exhibits improved resolution and depth sensing. The approach is based on a multi-probe scanning probe microscopy (SPM tool that utilizes tuning-fork based probes for both indentation and depth sensing. Unlike nanoindentation experiments performed with conventional AFM systems using beam-bounce technology, this technique incorporates a second probe system with an ultra-high resolution for depth sensing. The additional second probe measures only the vertical movement of the straight indenter attached to a tuning-fork probe with a high spring constant and it can also be used for AFM scanning to obtain an accurate profiling. Nanoindentation results are demonstrated on silicon, fused silica, and Corning Eagle Glass. The results show that this new approach is viable in terms of accurately characterizing mechanical properties of materials through nanoindentation with high accuracy, and it opens doors to many other exciting applications in the field of nanomechanical characterization.

  1. [Attachment behavior with respect to mothers and fathers and attachment representations in five and seven-year-old children]. (United States)

    König, Lilith; Gloger-Tippelt, Gabriele; Zweyer, Karen


    During preschool and early school age attachment quality can be assessed by different means: at the behavioral level by the Strange Situation (SS), at the representational level by semiprojective methods using story stems or pictures. Both methods gain access to different levels of a theoretically assumed inner working model of attachment, in which attachment at the behavioral level is supposed to be person specific, attachment at the representational level generalized. This study aimed at analyzing whether attachment behavior to mother and father is associated, and how it is linked to the generalized attachment representation. It was also examined whether in the case of no association between mother and father attachment behavior towards the major attachment figure is linked to the attachment representation. In the Duesseldorf study 67 children aged 5 years were observed in the SS with mother, 31 of them also in the SS with father. At the age of 6.5 years an attachment story completion task was conducted. When person specific attachment to mother and father was congruent (SS secure n=6, or insecure n=8) the attachment representation was consistent as well, when father and mother attachment were discrepant no association with attachment representation could be found. The findings did not confirm a stronger influence of the major attachment figure on the formation of the attachment representation.

  2. An Exploratory Study of the Association between Reactive Attachment Disorder and Attachment Narratives in Early School-Age Children (United States)

    Minnis, Helen; Green, Jonathan; O'Connor, Thomas G.; Liew, Ashley; Glaser, D.; Taylor, E.; Follan, M.; Young, D.; Barnes, J.; Gillberg, C.; Pelosi, A.; Arthur, J.; Burston, A.; Connolly, B.; Sadiq, F. A.


    Objective: To explore attachment narratives in children diagnosed with reactive attachment disorder (RAD). Method: We compared attachment narratives, as measured by the Manchester Child Attachment Story Task, in a group of 33 children with a diagnosis of RAD and 37 comparison children. Results: The relative risk (RR) for children with RAD having…

  3. Direct Probes of 4 nm Diameter Gold Nanoparticles Interacting with Supported Lipid Bylayers

    Energy Technology Data Exchange (ETDEWEB)

    Troiano, Julianne; Olenick, Laura L.; Kuech, Thomas R.; Melby, Eric S.; Hu, Dehong; Lohse, Samuel E.; Mensch, Arielle C.; Dogangun, Merve; Vartanian, Arlane M.; Torelli, Marco; Ehimiaghe, Eseohi; Walter, Stephanie R.; Fu, Li; Anderton, Christopher R.; Zhu, Zihua; Wang, Hongfei; Orr, Galya; Murphy, Catherine; Hamers, Robert J.; Pedersen, Joel A.; Geiger, Franz M.


    Interfacial charge densities and potentials are determined for silica-supported phospholipid bilayers formed from lipids having zwitterionic, negatively charged, and positively charged headgroups. Quartz crystal microbalance with dissipation (QCM-D), fluorescence recovery after photobleaching (FRAP), and atomic force microscopy demonstrate the presence of well-formed supported lipid bilayers, which, as probed by vibrational sum frequency generation (SFG), undergo negligible structural changes along their alkyl chains when NaCl concentration is raised from 0.001 to 0.1 M. From second harmonic generation (SHG) measurements we estimate that each zwitterionic headgroup of the bilayer formed from pure DOPC is associated with an apparent charge of -0.028(+0.008/-0.007)×10-¹⁹C, corresponding to 1.8 ± 0.5 % of an elementary negative charge. Moreover, we show that a supported lipid bilayer carrying an apparent negative interfacial potential may interact with not just positively charged 4-nm diameter gold nanoparticles but also negatively charged gold nanoparticles. In this latter case, charge-charge repulsion does not appear to inhibit particle-bilayer interactions and is likely overcome by multivalent interactions that are estimated to involve 3-5 hydrogen-bond equivalents. FRAP, QCM-D, and SFG measurements indicate that the bilayers remain intact under the conditions of the experiments. SHG charge screening experiments are consistent with an apparent zero net charge density associated with the positively charged gold nanoparticles when they are attached to a supported lipid bilayer carrying an apparent negative potential. The results presented here serve to benchmark experimental and computational studies of the nano-bio interface.

  4. Bowlby's attachment theory: implications for health visiting. (United States)

    Partis, M


    This article reviews the current state of research in attachment theory. It also examines the relations between attachment, child care and development, and the significance of attachment to adult functioning and well-being. It seems likely that humans need close emotional relationships or bonds with others. This need applies particularly to infants, who look to parents or other care givers for love and security. The best-known psychological explanation of this need is attachment theory, which has been influential in increasing our understanding of the early mother-infant relationship, and in the formulation of guidelines for child care (Melhuish, 1998). Good-quality parental care may be difficult to define, and questions remain regarding the nature of child care and the consequences that it can have for later development. This article concludes with a discussion of the possible implications for health-visitor intervention within families, which are intended to improve the quality of the relationship between parents or care givers and the infant.

  5. Maternal anxiety, maternal sensitivity, and attachment

    NARCIS (Netherlands)

    Stevenson-Hinde, Joan; Chicot, Rebecca; Shouldice, Anne; Hinde, Camilla A.


    Previous research has related maternal anxiety to insecurity of attachment. Here we ask whether different aspects of maternal sensitivity mediate this link. From a community sample of intact families with 1-3 children, mothers with 4.5-year-olds were selected for low, medium, or high anxiety leve

  6. No Strings Attached: Open Source Solutions (United States)

    Fredricks, Kathy


    Imagine downloading a new software application and not having to worry about licensing, finding dollars in the budget, or incurring additional maintenance costs. Imagine finding a Web design tool in the public domain--free for use. Imagine major universities that provide online courses with no strings attached. Imagine online textbooks without a…

  7. Childhood Abuse and Attachment Styles of Adolescents (United States)

    Karakus, Ozlem


    Introduction: The fact that emotional and social experiences in early childhood period within the family influence the experiences in adolescence and adulthood (communication skills, interpersonal relations) is not a new case. Therefore, the aim of this study is to examine the relationship between childhood abuse and attachment styles. Method: The…

  8. What is preferential to preferential attachment?

    CERN Document Server

    Small, Michael; Stemler, Thomas


    Preferential attachment --- where new nodes are added and attached to existing nodes with probability proportional to the existing nodes' degree --- has become the standard growth model for scale-free networks, where the asymptotic probability of a node having degree $k$ is proportional to $k^{-\\gamma}$. However, the motivation for this model is entirely {\\em ad hoc}. We use exact likelihood arguments and show that the optimal way to build a scale-free network is to preferentially attach to low degree nodes. Asymptotically, the optimal strategy is to attach the new node to one of the nodes of degree $k$ (in a network with $N$ nodes) with probability proportional to $\\frac{1}{N+\\zeta(\\gamma)(k+1)^\\gamma}$. The algorithm we propose to do this can be employed to generate optimally scale-free networks (maximum likelihood realisations) as well as a random sampling of the space of all scale-free networks with a given degree exponent $\\gamma$. While we focus on scale free networks, these methods can be applied to a ...

  9. Attachment Styles, Abuse Experiences and Depression (United States)

    Gunduz, Bulent; Capri, Burhan; Akbay, Sinem Evin; Tunc, Aygul


    This study aims to examine the relationship between abuse experiences, depression and attachment styles. The data for this study was collected from 251 students (123 females and 128 males) who attend Mersin University. As a part of the data collection, students completed the Experiences in Affiliation Inventory, Childhood Trauma Scale and Brief…

  10. Reactive attachment disorder as an evolutionary adaptation. (United States)

    Balbernie, Robin


    This paper suggests that the behaviours associated with the formal diagnosis of the "disinhibited" form of reactive attachment disorder (RAD) might be seen as a functional adaptation rather than a mental health problem, a facultative response enhancing the probability of survival that is triggered by certain conditions. Although disinhibited RAD is most commonly observed in institutionalised children, similar behaviours may also be a part of the emotional difficulties displayed by some fostered and adopted children (the latter includes those once institutionalised), and these may demonstrate not so much a discrete attachment disorder as either the need to fend for oneself following loss of dedicated caregiving or a lack of opportunity to build specific intimate relationships with dedicated caregivers. In many cases this may be inextricably mixed with the neurobiological and psychological seqelae of maltreatment. Indiscriminate attachment behaviour, from this proposed evolutionary perspective, is less a syndrome of mental ill-health than an astute survival manoeuvre following being orphaned, abandoned or fecklessly reared. Such a response, allied to the innate facility to access caregiving from different adults, could be expected to be initiated by specific events as are the other attachment configurations. Classing disinhibited RAD as an adaptation has implications for helping children brought up under extreme duress when their caregiving environment has changed for the better.

  11. Reactive Attachment Disorder in Maltreated Toddlers (United States)

    Zeanah, Charles H.; Scheeringa, Michael; Boris, Neil W.; Heller, Sherryl S.; Smyke, Anna T.; Trapani, Jennifer


    Objective: To determine if Reactive Attachment Disorder (RAD) can be reliably identified in maltreated toddlers in foster care, if the two types of RAD are independent, and to estimate the prevalence of RAD in these maltreated toddlers. Methods: Clinicians treating 94 maltreated toddlers in foster care were interviewed regarding signs of…

  12. Hidden Regulators in Attachment, Separation, and Loss. (United States)

    Hofer, Myron A.


    This essay discusses the similarities between animal behavior and human attachment behavior demonstrated by infants and their mothers. The provision of warmth, the tactile and olfactory stimulation of the mother's physical interactions, and the oral sensory and absorptive consequences of nursing are found to provide specific and independent…

  13. Maternal anxiety, maternal sensitivity, and attachment

    NARCIS (Netherlands)

    Stevenson-Hinde, J.; Chicot, R.; Schouldice, A.; Hinde, C.A.


    Previous research has related maternal anxiety to insecurity of attachment. Here we ask whether different aspects of maternal sensitivity mediate this link. From a community sample of intact families with 1-3 children, mothers with 4.5-year-olds were selected for low, medium, or high anxiety levels

  14. Should Charity Donations Have Strings Attached?

    Institute of Scientific and Technical Information of China (English)


    The commonly held belief among most people is that acts of charity are carried out with no thought of getting something in return, or of attaching conditions to those who receive donations. It’s perhaps for this rea- son that events surrounding the Henan Charity Federation’s recent decision to add an agenda to students’ financial aid caused such a public outcry.

  15. Sexuality examined through the lens of attachment theory: attachment, caregiving, and sexual satisfaction. (United States)

    Péloquin, Katherine; Brassard, Audrey; Lafontaine, Marie-France; Shaver, Phillip R


    Attachment researchers have proposed that the attachment, caregiving, and sexual behavioral systems are interrelated in adult love relationships (Mikulincer & Shaver, 2007 ). This study examined whether aspects of partners' caregiving (proximity, sensitivity, control, compulsive caregiving) mediated the association between their attachment insecurities (anxiety and avoidance) and each other's sexual satisfaction in two samples of committed couples (Study 1: 126 cohabiting or married couples from the general community; Study 2: 55 clinically distressed couples). Partners completed the Experiences in Close Relationships measure (Brennan, Clark, & Shaver, 1998 ), the Caregiving Questionnaire (Kunce & Shaver, 1994 ), and the Global Measure of Sexual Satisfaction (Lawrance & Byers, 1998 ). Path analyses based on the actor-partner interdependence model (APIM) revealed that caregiving proximity mediated the association between low attachment avoidance and partners' sexual satisfaction in distressed and nondistressed couples. Sensitivity mediated this association in nondistressed couples only. Control mediated the association between men's insecurities (attachment-related avoidance and anxiety) and their partners' low sexual satisfaction in nondistressed couples. Attachment anxiety predicted compulsive caregiving, but this caregiving dimension was not a significant mediator. These results are discussed in light of attachment theory and their implications for treating distressed couples.

  16. Measuring infant attachment security in rhesus macaques (Macaca mulatta): adaptation of the attachment Q-set. (United States)

    Warfield, James J; Kondo-Ikemura, Kiyomi; Waters, Everett


    John Bowlby defined offspring-parent attachment as a relationship in which an infant or child uses one or a few preferred adults as a secure base from which to explore and as a haven of safety. He defined attachment security in terms of confidence in the adult's availability and responsiveness and the smooth organization of exploration and proximity seeking. Developmental psychologists have found this perspective productive in both observational and laboratory research. At the same time, they emphasize that such a construct cannot be operationalized in terms of one or a few behaviors. Instead, naturalistic observations of human infant attachment typically employ the Q-sort method to develop the Attachment q-set (AQS), 90 behaviorally descriptive items sorted in terms of how characteristic each item is of the infant's typical behavior. Meta-analyses of research using the AQS attest to its reliability and validity. This article reports an adaptation of the AQS to the task of assessing infant attachment security in nonhuman primates and illustrates its use. The availability of comparable measures of attachment security will contribute to an expanded understanding of patterns of attachment behavior in nonhuman primate societies and will facilitate interaction between comparative and developmental psychologists.

  17. Effect of Attachment-Based Therapy on Behavioral Disorders in Girls with Attachment Problems

    Directory of Open Access Journals (Sweden)

    Marzieh Jahanbakhsh


    Full Text Available Background: Multidimensional and complex nature of children`s behavioral disorders requires assessment and usage of modern treatments. The present study investigated the effects of attachment-based therapy on behavioral disorders (depression, over anxiety and oppositional defiant in girl students of primary school who had attachment problems. Materials and Methods: This study is an empirical plan with pretest-posttest and control group. The target samples were 34 individuals of 388 second and fourth grade students of primary school that had highest scores on attachment problems and behavioral disorders (depression, over anxiety and oppositional defiant. Evaluation implemented using Randolph attachment disorder questionnaire (RADQ and Ontario mental health test. Mothers were presented in 10 group sessions of attachment-based intervention and its effects investigated in their girl`s behavioral disorders (depression, over anxiety and oppositional defiant. Results: Reduction rate of behavioral disorders general scores (depression, over anxiety and oppositional defiant of experimental group compared with control group showed significant decreases in posttest and three months follow up. Conclusion: The attachment based therapy offered for mothers of the girls with attachment problems was effective to reduction of behavioral disorders (depression, over anxiety and oppositional defiant symptoms in their children and the mother`s continues attention to interventional methods showed more improvement in follow up evaluation.

  18. Infant attachment, adult attachment, and maternal sensitivity: revisiting the intergenerational transmission gap. (United States)

    Behrens, Kazuko Y; Haltigan, John D; Bahm, Naomi I Gribneau


    This study investigated the intergenerational transmission of attachment, utilizing the Adult Attachment Interview (AAI), the Strange Situation Procedure (SSP), and the Maternal Behavioral Q-Set (MBQS). We revisited fundamental questions in attachment theory and research by examining: (1) the level of intergenerational agreement between maternal attachment representations and infant attachment security, and (2) whether maternal sensitivity serves as an intergenerational mediator between adult and infant attachment security. Significant categorical matches between the AAI and the SSP as well as mean differences for MBQS scores between adult attachment secure-insecure groups were found. Consistent with earlier intergenerational research, maternal sensitivity only partially mediated the AAI-SSP link, indicating the transmission gap remains. Consistent with recent mediation studies, using more contemporary analytical techniques, it was confirmed that maternal sensitivity did mediate the direct pathway between AAI security and SSP security. Thus, the transmission gap appears somewhat different depending on the statistical method used to measure mediation. Post hoc analyses considered mothers' childhood experiences of separation/divorce and this helped make sense of intergenerational mismatches.

  19. Inducing spin-dependent tunneling to probe magnetic correlations in optical lattices

    DEFF Research Database (Denmark)

    Pedersen, Kim-Georg; Andersen, Brian; Syljuåsen, Olav;


    We suggest a simple experimental method for probing antiferromagnetic spin correlations of two-component Fermi gases in optical lattices. The method relies on a spin selective Raman transition to excite atoms of one spin species to their first excited vibrational mode where the tunneling is large...

  20. Vibration amplitude of a tip-loaded quartz tuning fork during shear force microscopy scanning (United States)

    Sandoz, P.; Friedt, J.-M.; Carry, É.


    This Note reports on experimental results obtained with a recently published vision method for in-plane vibration measurement [Sandoz et al., Rev. Sci. Instrum. 78, 023706 (2007)]. The latter is applied to a tip-loaded quartz tuning fork frequently used in scanning probe microscopy for shear-force monitoring of the tip-sample distance. The vibration amplitude of the tip-loaded prong is compared to that of the free one and the damping induced by tip-surface interactions is measured. The tuning-fork behavior is characterized during approaches from free space to surface contact. Tip-surface contact is clearly identified by a drastic reduction in the prong vibration amplitude. However, no differences were observed between hydrophilic and hydrophobic surfaces. Experiments reported here show that the vibration amplitude of the quartz tuning fork in free space is a good estimate of the vibration amplitude of the tip interacting with the sample surface during shear force sample-tip feedback. The experimental setup for measuring the amplitude is easily integrated in an inverted microscope setup on which the shear force microscope is installed for simultaneous scanning probe and optical microscopy analysis of the sample.

  1. Application of tuned liquid damper in vibration suppression of wind towers

    Energy Technology Data Exchange (ETDEWEB)

    Poshnejad, A. [Ryerson Polytechnic Univ., Toronto, ON (Canada)


    The structural responses of a wind turbine were simulated with an attached damping tuned liquid damper (TLD) designed to control vibrations. The proposed TLD was an annular liquid container designed to be installed below the nacelle around the tower body. The TLD-structure system was formulated as a nonlinear coupled response between the TLD hydrodynamic force and the structure response. The effectiveness of the damper was compared with the dampers typically used in antenna designs. A circuit shallow TLD was used as a vibration damper. The sloshing behaviour of water was then modelled using a computational fluid dynamics (CFD) tool and an equivalent mechanical model. Vibration dynamics were considered for the rotor blades; the mechanical-electrical drive train; the yaw system; and the entire wind turbine. Results of the investigation demonstrated that the TLD effectively increased the damping of the wind tower. tabs., figs.

  2. Active control of sound radiated by a submarine in bending vibration (United States)

    Caresta, Mauro


    This paper theoretically investigates the use of inertial actuators to reduce the sound radiated by a submarine hull in bending vibration under harmonic excitation from the propeller. The radial forces from the propeller are tonal at the blade passing frequency and are transmitted to the hull through the stern end cone. The hull is modelled as a fluid loaded cylindrical shell with ring stiffeners and two equally spaced bulkheads. The cylinder is closed by end-plates and conical end caps. The actuators are arranged in circumferential arrays and attached to the prow end cone. Both Active Vibration Control and Active Structural Acoustic Control are analysed. The inertial actuators can provide control forces with a magnitude large enough to reduce the sound radiated by the vibrations of the hull in some frequency ranges.

  3. Vibration Compensation for Scanning Tunneling Microscope

    Institute of Scientific and Technical Information of China (English)

    LI Meng-chao; FU Xing; WEI Xiao-lei; HU Xiao-tang


    The influence of vibration is already one of main obstacles for improving the nano measuring accuracy.The techniques of anti-vibration,vibration isolation and vibration compensation become an important branch in nano measuring field.Starting with the research of sensitivity to vibration of scanning tunneling microscope(STM),the theory,techniques and realization methods of nano vibration sensor based on tunnel effect are initially investigated,followed by developing the experimental devices.The experiments of the vibration detection and vibration compensation are carried out.The experimental results show that vibration sensor based on tunnel effect is characterized by high sensitivity,good frequency characteristic and the same vibratory response characteristic consistent with STM.


    Energy Technology Data Exchange (ETDEWEB)



    Recently studies examining the colonization of Clostridial pathogens on agar and human tissue culture cells, demonstrated that (C. sporogenes ATCC 3584, C. difficile ATCC 43594 [patient isolate], C. difficile ATCC 9689 [non-clinical], C. clostridioforme [patient isolate]) bacterial spores (endospores) of the genus Clostridia have an outer membrane that becomes responsive at activation and exhibits extensions of the exosporial membrane that facilitate and maintain spore attachment to a nutritive substrate during germination and initial outgrowth of the newly developed bacterial cell. Therefore this attachment phenomenon plays an important role in insuring bacterial colonization of a surface and the initial stages of the infective process. To see if other non-clinical members of this genus also have this ability to attach to a substrate or food-source during spore germination, and how this attachment process in environmental thermophiles compares to the clinical paradigm (in relation to time sequence, exosporial membrane structure, type of attachment structures, composition of the membrane etc...), sediment samples were collected in sterile transport containers at 4 geothermal sites at Yellowstone National Park in Wyoming. Because spore forming bacteria will produce spores when conditions are unfavorable for growth, the samples were sealed and stored at 4 C. After 8 months the samples were screened for the presence of spores by light microscope examination using malachite green/safranin, and traditional endospores were identified in significant quantities from the Terrace Spring site (a 46 C lake with bacterial mats and a rapidly moving run-off channel leading to a traditional hot spring). The highest spore population was found in the top sediment and benthic water of the run-off channel, pH 8.1.


    Institute of Scientific and Technical Information of China (English)

    X.C.Zhao; Y.D.Zhang; H.W.Zhang; Q.Wu


    A finite element model is developed for the simulation of vibration stress relief (VSR) after welding.For the nonresonant vibration,the reduction in stress strongly depends on the amplitude of vibration.For the resonant vibration,the vibration frequency is the key for stress relief.The vibration frequency should be close to the structure natural frequency for the desired vibration mode.Only small vibration amplitude is required,which will be amplified during vibration.Vibration time does not have a major impact on vibration stress relief.When the amplitude of vibration stress relief is large,the treatment will be more effective.

  6. Electron attachment rate constant measurement by photoemission electron attachment ion mobility spectrometry (PE-EA-IMS) (United States)

    Su, Desheng; Niu, Wenqi; Liu, Sheng; Shen, Chengyin; Huang, Chaoqun; Wang, Hongmei; Jiang, Haihe; Chu, Yannan


    Photoemission electron attachment ion mobility spectrometry (PE-EA-IMS), with a source of photoelectrons induced by vacuum ultraviolet radiation on a metal surface, has been developed to study electron attachment reaction at atmospheric pressure using nitrogen as the buffer gas. Based on the negative ion mobility spectra, the rate constants for electron attachment to tetrachloromethane and chloroform were measured at ambient temperature as a function of the average electron energy in the range from 0.29 to 0.96 eV. The experimental results are in good agreement with the data reported in the literature.

  7. Analysis of a Lorentz force based vibration exciter using permanent magnets mounted on a piezoelectric stack

    Indian Academy of Sciences (India)

    Arghya Nandi; Sumanta Neogy; Sankha Bhaduri


    This work presents performance analysis of a Lorentz force based noncontact vibration exciter by mounting a couple of permanent magnets on a piezoelectric stack. A conductor is attached to the structure to be excited and is placed midway between unlike poles of a couple of permanent magnets. The permanent magnets are placed on a piezoelectric stack. This stack, because of its nano-positioning capabilities, can impart an accurate and adjustable harmonic vibratory motion to the couple of permanent magnets. The piezoelectric stack, because of its high stiffness remains uncoupled with the dynamics of the structure. Due to the relative motion between the magnets and the conductor, Lorentz force is generated within the conductor. This Lorentz force is responsible for vibration of the structure in a plane parallel to the pole faces of the magnets. This keeps the magnetic field almost independent of the vibration of the structure and the chance of the structure hitting the magnet during large vibration is totally eliminated. If the amplitude of displacement of the stack is kept constant, the non-contact excitation force in this exciter remains proportional to the excitation frequency. Though use of this exciter eliminates mass (apart from that of the conductor attached to the structure) and stiffness coupling, a known damping term gets added to that of the excited structure.

  8. Microelectronics Instrument Products Shock and Vibration Electro-Optics. Section B; Acceptance Data Package (United States)


    The motor/encoder (henceforth referred to as the UUT) test sequence began with a baseline functional evaluation, which demonstrated that the motor satisfied the operating torque, cogging torque, winding resistance, and mechanical requirements of SOW. In addition, the encoder electrical requirements were verified, as well as the alignment of the encoder outputs relative to the motor shaft position. There were no discrepancies observed in this portion of the test. The UUT was then exposed to a number of environments, including thermal vacuum, thermal cycling, random and sine vibration, and mechanical shock. During the thermal environments, the performance of the UUT under load was verified at specified points in the cycles, as described in ATP 20049. In addition, the UUT was bench tested between the two thermal environments. No anomalies were observed during the thermal tests. The vibration and shock tests were performed by East-West Technology Corporation, West Babylon, New York. The UUT was delivered to the lab in a sealed vibration fixture in order to maintain the cleanliness levels required by the SOW. In addition, a three ounce load was attached to the motor shaft. The attachment method of this load caused damage to the shaft and bearing during random vibration of S/N 0003 on April 28, 1995, and is described further in NCR 00168.


    Institute of Scientific and Technical Information of China (English)

    XU Zongwei; DONG Shen; GUO Liqiu; ZHAO Qingliang


    An improved arc discharge method is developed to fabricate carbon nanotube probe of atomic force microscopy (AFM) here. First, silicon probe and carbon nanotube are manipulated under an optical microscope by two high precision microtranslators. When silicon probe and carbon nanotube are very close, several tens voltage is applied between them. And carbon nanotube is divided and attached to the end of silicon probe, which mainly due to the arc welding function.Comparing with the arc discharge method before, the new method here needs no coat silicon probe with metal film in advance, which can greatly reduce the fabrication's difficulty. The fabricated carbon nanotube probe shows good property of higher aspect ratio and can more accurately reflect the true topography of silicon grating than silicon probe. Under the same image drive force, carbon nanotube probe had less indentation depth on soft triblock copolymer sample than silicon probe. This showed that carbon nanotube probe has lower spring constant and less damage to the scan sample than silicon probe.

  10. Vibrational Microspectroscopy for Cancer Screening

    Directory of Open Access Journals (Sweden)

    Fiona M. Lyng


    Full Text Available Vibrational spectroscopy analyses vibrations within a molecule and can be used to characterise a molecular structure. Raman spectroscopy is one of the vibrational spectroscopic techniques, in which incident radiation is used to induce vibrations in the molecules of a sample, and the scattered radiation may be used to characterise the sample in a rapid and non-destructive manner. Infrared (IR spectroscopy is a complementary vibrational spectroscopic technique based on the absorption of IR radiation by the sample. Molecules absorb specific frequencies of the incident light which are characteristic of their structure. IR and Raman spectroscopy are sensitive to subtle biochemical changes occurring at the molecular level allowing spectral variations corresponding to disease onset to be detected. Over the past 15 years, there have been numerous reports demonstrating the potential of IR and Raman spectroscopy together with multivariate statistical analysis techniques for the detection of a variety of cancers including, breast, lung, brain, colon, oral, oesophageal, prostate and cervical cancer. This paper discusses the recent advances and the future perspectives in relation to cancer screening applications, focussing on cervical and oral cancer.

  11. Design for Vibrator Field Experiment Based- on Vibrator- earth System

    Institute of Scientific and Technical Information of China (English)

    Chen Zubin; Lin Jun; Liang Tiecheng; Zhang Linhang


    Source- generated energy in seismic vibrator records high frequency harmonic behavior. Conventional vibratorearth coupling model was set up on the linear system. Some assumptions in the application of linear theory to the vibrator problem play an insignificant role in the overall coupling structure. Obviously, non- linear behaviors can be modeled using a "hard - spring" form of the Duffing equation. Model dedicates that a qualitatively similar harmonic component is present for a broad range of possible mathematical descriptions. After some qualitative analysis about the non- linear system, some conclusion can be drawn. Firstly, The design of the vibrator weight should be abided by two points as followed: In order to avoid decoupling for the vibrator to the earth, the weight should be greater than the peak of the driving force amplitude as to keep the resultant force pointing to the earth's core. On the other hand, for the limited energy output, the vibrator overweight may damage the system high - frequency ability. Secondly, as the driving force frequency approaching to the ground hard- spring inherent frequency, the energy transmission was found to climb its peak from the system energy absorbed curve. At last, due to the non- linear coupling model system, its load curve would come into unstable frequency range,which might limit the application of the Vibroseis conventional sweeping pattern - linear sweep. A new sweeping pattern was listed: the driving signal was the pseudo- random sequence modulated by a fixed frequency cosine signal satisfying with the exploration precision and absorbing efficiency. The synthesized signal was ready to be realized by the electromagnetic driven system. Even the side- lobes noise of its auto- correlation function was restrained well. The theory coming from the Vibrator- earth coupling model was applied to the design of the Portable High- frequency Vibrator System (PHVS), and the good result was obtained. By the analysis of the

  12. Research on cylindrical shell vibration reduction systems

    Institute of Scientific and Technical Information of China (English)

    XING Xiao-liang; WANG Min-qing


    Longitudinal and horizontal vibration must both be reduced in an effective vibration isolation system. We present a cylindrical shell vibration isolator as a dynamic system composed of four springs and dampers. Vibration is directly produced by the motion of machinery, and more is subsequently generated by harmonic frequencies within their structure. To test the effectiveness of our isolator, we first determined equations for the transmission of vibration from the machine to its cylindrical shell. Damping effects produced by the vibration parameters of our system are then analyzed.

  13. Alignment, vibronic level splitting, and coherent coupling effects on the pump-probe polarization anisotropy. (United States)

    Smith, Eric R; Jonas, David M


    The pump-probe polarization anisotropy is computed for molecules with a nondegenerate ground state, two degenerate or nearly degenerate excited states with perpendicular transition dipoles, and no resonant excited-state absorption. Including finite pulse effects, the initial polarization anisotropy at zero pump-probe delay is predicted to be r(0) = 3/10 with coherent excitation. During pulse overlap, it is shown that the four-wave mixing classification of signal pathways as ground or excited state is not useful for pump-probe signals. Therefore, a reclassification useful for pump-probe experiments is proposed, and the coherent anisotropy is discussed in terms of a more general transition dipole and molecular axis alignment instead of experiment-dependent ground- versus excited-state pathways. Although coherent excitation enhances alignment of the transition dipole, the molecular axes are less aligned than for a single dipole transition, lowering the initial anisotropy. As the splitting between excited states increases beyond the laser bandwidth and absorption line width, the initial anisotropy increases from 3/10 to 4/10. Asymmetric vibrational coordinates that lift the degeneracy control the electronic energy gap and off-diagonal coupling between electronic states. These vibrations dephase coherence and equilibrate the populations of the (nearly) degenerate states, causing the anisotropy to decay (possibly with oscillations) to 1/10. Small amounts of asymmetric inhomogeneity (2 cm(-1)) cause rapid (130 fs) suppression of both vibrational and electronic anisotropy beats on the excited state, but not vibrational beats on the ground electronic state. Recent measurements of conical intersection dynamics in a silicon napthalocyanine revealed anisotropic quantum beats that had to be assigned to asymmetric vibrations on the ground electronic state only [Farrow, D. A.; J. Chem. Phys. 2008, 128, 144510]. Small environmental asymmetries likely explain the observed absence

  14. 3'-functionalized adamantyl cannabinoid receptor probes. (United States)

    Ogawa, Go; Tius, Marcus A; Zhou, Han; Nikas, Spyros P; Halikhedkar, Aneetha; Mallipeddi, Srikrishnan; Makriyannis, Alexandros


    The aliphatic side chain plays a pivotal role in determining the cannabinergic potency of tricyclic classical cannabinoids, and we have previously shown that this chain could be substituted successfully by adamantyl or other polycyclic groups. In an effort to explore the pharmacophoric features of these conformationally fixed groups, we have synthesized a series of analogues in which the C3 position is substituted directly with an adamantyl group bearing functionality at one of the tertiary carbon atoms. These substituents included the electrophilic isothiocyanate and photoactivatable azido groups, both of which are capable of covalent attachment with the target protein. Our results show that substitution at the 3'-adamantyl position can lead to ligands with improved affinities and CB1/CB2 selectivities. Our work has also led to the development of two successful covalent probes with high affinities for both cannabinoid receptors, namely, the electrophilic isothiocyanate AM994 and the photoactivatable aliphatic azido AM993 analogues.

  15. A prospective 9-month human clinical evaluation of Laser-Assisted New Attachment Procedure (LANAP) therapy. (United States)

    Nevins, Marc; Kim, Soo-Woo; Camelo, Marcelo; Martin, Ignacio Sanz; Kim, David; Nevins, Myron


    This investigation was designed and implemented as a single-center, prospective study to evaluate the clinical response to the Laser-Assisted New Attachment Procedure (LANAP). Eight patients with advanced periodontitis were enrolled and treated with full-mouth LANAP therapy and monitored for 9 months. Fullmouth clinical measurements, including clinical attachment level (CAL), probing depth (PD), and recession, were provided at baseline and after 9 months of healing by a single calibrated examiner, including a total of 930 sites and 444 sites with initial PD equal to or greater than 5 mm. Clinical results for the 930 sites measured pre- and postoperatively revealed that mean PD was reduced from 4.62 ± 2.29 mm to 3.14 ± 1.48 mm after 9 months (P LANAP therapy should be further investigated with long-term clinical trials to compare the stability of clinical results with conventional therapy.

  16. Porcine dentin sialoprotein glycosylation and glycosaminoglycan attachments

    Directory of Open Access Journals (Sweden)

    Yamakoshi Fumiko


    Full Text Available Abstract Background Dentin sialophosphoprotein (Dspp is a multidomain, secreted protein that is critical for the formation of tooth dentin. Mutations in DSPP cause inherited dentin defects categorized as dentin dysplasia type II and dentinogenesis imperfecta type II and type III. Dentin sialoprotein (Dsp, the N-terminal domain of dentin sialophosphoprotein (Dspp, is a highly glycosylated proteoglycan, but little is known about the number, character, and attachment sites of its carbohydrate moieties. Results To identify its carbohydrate attachment sites we isolated Dsp from developing porcine molars and digested it with endoproteinase Glu-C or pronase, fractionated the digestion products, identified fractions containing glycosylated peptides using a phenol sulfuric acid assay, and characterized the glycopeptides by N-terminal sequencing, amino acid analyses, or LC/MSMS. To determine the average number of sialic acid attachments per N-glycosylation, we digested Dsp with glycopeptidase A, labeled the released N-glycosylations with 2-aminobenzoic acid, and quantified the moles of released glycosylations by comparison to labeled standards of known concentration. Sialic acid was released by sialidase digestion and quantified by measuring β-NADH reduction of pyruvic acid, which was generated stoichiometrically from sialic acid by aldolase. To determine its forms, sialic acid released by sialidase digestion was labeled with 1,2-diamino-4,5-methyleneoxybenzene (DMB and compared to a DMB-labeled sialic acid reference panel by RP-HPLC. To determine the composition of Dsp glycosaminoglycan (GAG attachments, we digested Dsp with chondroitinase ABC and compared the chromotagraphic profiles of the released disaccharides to commercial standards. N-glycosylations were identified at Asn37, Asn77, Asn136, Asn155, Asn161, and Asn176. Dsp averages one sialic acid per N-glycosylation, which is always in the form of N-acetylneuraminic acid. O-glycosylations were

  17. Attaching Thermocouples by Peening or Crimping (United States)

    Murtland, Kevin; Cox, Robert; Immer, Christopher


    Two simple, effective techniques for attaching thermocouples to metal substrates have been devised for high-temperature applications in which attachment by such conventional means as welding, screws, epoxy, or tape would not be effective. The techniques have been used successfully to attach 0.005- in. (0.127-mm)-diameter type-S thermocouples to substrates of niobium alloy C-103 and stainless steel 416 for measuring temperatures up to 2,600 F (1,427 C). The techniques are equally applicable to other thermocouple and substrate materials. In the first technique, illustrated in the upper part of the figure, a hole slightly wider than twice the diameter of one thermocouple wire is drilled in the substrate. The thermocouple is placed in the hole, then the edge of the hole is peened in one or more places by use of a punch (see figure). The deformed material at the edge secures the thermocouple in the hole. In the second technique a hole is drilled as in the first technique, then an annular relief area is machined around the hole, resulting in structure reminiscent of a volcano in a crater. The thermocouple is placed in the hole as in the first technique, then the "volcano" material is either peened by use of a punch or crimped by use of sidecutters to secure the thermocouple in place. This second technique is preferable for very thin thermocouples [wire diameter .0.005 in. (.0.127 mm)] because standard peening poses a greater risk of clipping one or both of the thermocouple wires. These techniques offer the following advantages over prior thermocouple-attachment techniques: . Because these techniques involve drilling of very small holes, they are minimally invasive . an important advantage in that, to a first approximation, the thermal properties of surrounding areas are not appreciably affected. . These techniques do not involve introduction of any material, other than the substrate and thermocouple materials, that could cause contamination, could decompose, or oxidize

  18. Source model for blasting vibration

    Institute of Scientific and Technical Information of China (English)

    DING; Hua(丁桦); ZHENG; Zhemin(郑哲敏)


    By analyzing and comparing the experimental data, the point source moment theory and the cavity theory, it is concluded that the vibrating signals away from the blasting explosive come mainly from the natural vibrations of the geological structures near the broken blasting area. The source impulses are not spread mainly by the inelastic properties (such as through media damping, as believed to be the case by many researchers) of the medium in the propagation pass, but by this structure. Then an equivalent source model for the blasting vibrations of a fragmenting blasting is proposed, which shows the important role of the impulse of the source's time function under certain conditions. For the purpose of numerical simulation, the model is realized in FEM, The finite element results are in good agreement with the experimental data.

  19. Vibration analysis of atomising discs

    Energy Technology Data Exchange (ETDEWEB)

    Deng, H; Ouyang, H, E-mail: [Department of Engineering, University of Liverpool, Liverpool L69 3GH (United Kingdom)


    The centrifugal atomisation of metallic melts using a spinning disc is an important process for powder production and spray deposition. In the manufacturing process the high-temperature melt flows down to the surface of the atomising disc spinning at very high speed. It is observed that there is a hydraulic jump of the melt flow prior to atomisation. In this paper, the dynamic model of the atomising disc as a spinning Kirchhoff plate with this hydraulic jump is established. The flowing melt is modelled as moving mass and weight force in the radial direction. Using a Galerkin method, it is found that the vibration properties of the atomising disc vary with the disc clamping ratio. The amplitude of the vibration is largely raised when the clamping ratio is smaller than the critical jump radius ratio. It is also found that the disc vibration is non-stationary before becoming steady and the amplitude decreases with increasing disc speed.

  20. Mechanical Vibrations Modeling and Measurement

    CERN Document Server

    Schmitz, Tony L


    Mechanical Vibrations:Modeling and Measurement describes essential concepts in vibration analysis of mechanical systems. It incorporates the required mathematics, experimental techniques, fundamentals of modal analysis, and beam theory into a unified framework that is written to be accessible to undergraduate students,researchers, and practicing engineers. To unify the various concepts, a single experimental platform is used throughout the text to provide experimental data and evaluation. Engineering drawings for the platform are included in an appendix. Additionally, MATLAB programming solutions are integrated into the content throughout the text. This book also: Discusses model development using frequency response function measurements Presents a clear connection between continuous beam models and finite degree of freedom models Includes MATLAB code to support numerical examples that are integrated into the text narrative Uses mathematics to support vibrations theory and emphasizes the practical significanc...