Sample records for acoustically driven programmable

  1. Acoustically-driven microfluidic systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, A W; Benett, W J; Tarte, L R


    We have demonstrated a non-contact method of concentrating and mixing particles in a plastic microfluidic chamber employing acoustic radiation pressure. A flaw cell package has also been designed that integrates liquid sample interconnects, electrical contacts and a removable sample chamber. Experiments were performed on 1, 3, 6, and 10 {micro}m polystyrene beads. Increased antibody binding to a solid-phase substrate was observed in the presence of acoustic mixing due to improve mass transport.

  2. Computational dynamics of acoustically driven microsphere systems. (United States)

    Glosser, Connor; Piermarocchi, Carlo; Li, Jie; Dault, Dan; Shanker, B


    We propose a computational framework for the self-consistent dynamics of a microsphere system driven by a pulsed acoustic field in an ideal fluid. Our framework combines a molecular dynamics integrator describing the dynamics of the microsphere system with a time-dependent integral equation solver for the acoustic field that makes use of fields represented as surface expansions in spherical harmonic basis functions. The presented approach allows us to describe the interparticle interaction induced by the field as well as the dynamics of trapping in counter-propagating acoustic pulses. The integral equation formulation leads to equations of motion for the microspheres describing the effect of nondissipative drag forces. We show (1) that the field-induced interactions between the microspheres give rise to effective dipolar interactions, with effective dipoles defined by their velocities and (2) that the dominant effect of an ultrasound pulse through a cloud of microspheres gives rise mainly to a translation of the system, though we also observe both expansion and contraction of the cloud determined by the initial system geometry.

  3. Problem based Masters Programme in Acoustics - ten years of experience

    DEFF Research Database (Denmark)

    Nielsen, Sofus Birkedal


    The Section of Acoustics at Aalborg University in Denmark has more than 10 years of experience in offering a masters programme in Acoustics. The programme provides students with classical and modern aspects of physical acoustics, psychoacoustics and electro acoustics. Also signal processing which...

  4. Acoustic metamaterials with circular sector cavities and programmable densities. (United States)

    Akl, W; Elsabbagh, A; Baz, A


    Considerable interest has been devoted to the development of various classes of acoustic metamaterials that can control the propagation of acoustical wave energy throughout fluid domains. However, all the currently exerted efforts are focused on studying passive metamaterials with fixed material properties. In this paper, the emphasis is placed on the development of a class of composite one-dimensional acoustic metamaterials with effective densities that are programmed to adapt to any prescribed pattern along the metamaterial. The proposed acoustic metamaterial is composed of a periodic arrangement of cell structures, in which each cell consists of a circular sector cavity bounded by actively controlled flexible panels to provide the capability for manipulating the overall effective dynamic density. The theoretical analysis of this class of multilayered composite active acoustic metamaterials (CAAMM) is presented and the theoretical predictions are determined for a cascading array of fluid cavities coupled to flexible piezoelectric active boundaries forming the metamaterial domain with programmable dynamic density. The stiffness of the piezoelectric boundaries is electrically manipulated to control the overall density of the individual cells utilizing the strong coupling with the fluid domain and using direct acoustic pressure feedback. The interaction between the neighboring cells of the composite metamaterial is modeled using a lumped-parameter approach. Numerical examples are presented to demonstrate the performance characteristics of the proposed CAAMM and its potential for generating prescribed spatial and spectral patterns of density variation.

  5. Drift and ion acoustic wave driven vortices with superthermal electrons

    Energy Technology Data Exchange (ETDEWEB)

    Ali Shan, S. [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan); National Centre For Physics (NCP), Shahdra Valley Road, QAU Campus, 44000 Islamabad (Pakistan); Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad (Pakistan); Haque, Q. [Theoretical Plasma Physics Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan); National Centre For Physics (NCP), Shahdra Valley Road, QAU Campus, 44000 Islamabad (Pakistan)


    Linear and nonlinear analysis of coupled drift and acoustic mode is presented in an inhomogeneous electron-ion plasma with {kappa}-distributed electrons. A linear dispersion relation is found which shows that the phase speed of both the drift wave and the ion acoustic wave decreases in the presence of superthermal electrons. Several limiting cases are also discussed. In the nonlinear regime, stationary solutions in the form of dipolar and monopolar vortices are obtained. It is shown that the condition for the boundedness of the solution implies that the speed of drift wave driven vortices reduces with increase in superthermality effect. Ignoring density inhomogeniety, it is investigated that the lower and upper limits on the speed of the ion acoustic driven vortices spread with the inclusion of high energy electrons. The importance of results with reference to space plasmas is also pointed out.

  6. Computational dynamics of acoustically-driven microsphere systems

    CERN Document Server

    Glosser, Connor A; Dault, Daniel L; Piermarocchi, Carlo; Shanker, Balasubramaniam


    We propose a computational framework for the self-consistent dynamics of a microsphere system driven by a pulsed acoustic field in an ideal fluid. Our framework combines a molecular dynamics integrator describing the dynamics of the microsphere system with a time-dependent integral equation solver for the acoustic field that makes use of fields represented as surface expansions in spherical harmonic basis functions. The presented approach allows us to describe the inter-particle interaction induced by the field as well as the dynamics of trapping in counter-propagating acoustic pulses. The integral equation formulation leads to equations of motion for the microspheres describing the effect of non-dissipative drag forces. We show (1) that the field-induced interactions between the microspheres give rise to effective dipolar interactions, with effective dipoles defined by their velocities, and (2) that the dominant effect of an ultrasound pulse through a cloud of microspheres gives rise mainly to a translation ...

  7. Modeling Acoustically Driven Microbubbles by Macroscopic Discrete-Mechanical Analogues

    Directory of Open Access Journals (Sweden)

    Víctor Sánchez-Morcillo


    Full Text Available The dynamics of continuous systems that exhibit circular or spherical symmetry like drops, bubbles or some macromolecules, under the influence of some external excitation, develop surface patters that are hard to predict in most practical situations. In the particular case of acoustically driven microbubbles (ultrasound contrast agent, the study of the behavior of the bubble shell requires complex modeling even for describe the most simple oscillation patterns. Furthermore, due to the smallness of the spatio-temporal scale of the problem, an experimental approach requires expensive hardware setup. Despite the complexity of the particular physical problem, the basic dynamical features of some continuous physical systems can be captured by simple models of coupled oscillators. In this work we consider an analogy between a shelled-gas bubble cavitating under the action of an acoustic field and a discrete mechanical system. Thus, we present a theoretical and experimental study of the spatial instabilities of a circular ring of coupled pendulums parametrically driven by a vertical harmonic force. The system is capable of wave propagation and exhibit nonlinearities and dispersion, so manifest rich dynamics: normal oscillation modes (breathing, dipole, quadrupole... and localized patterns of different types (breathers and kinks witch are predicted by finite-differences numerical solutions and observed experimentally. On the basis of this analogy, the oscillation patterns and localized modes observed experimentally in acoustically driven bubbles are interpreted and discussed.

  8. Acoustically Driven Magnetized Target Fusion At General Fusion: An Overview (United States)

    O'Shea, Peter; Laberge, M.; Donaldson, M.; Delage, M.; the Fusion Team, General


    Magnetized Target Fusion (MTF) involves compressing an initial magnetically confined plasma of about 1e23 m-3, 100eV, 7 Tesla, 20 cm radius, >100 μsec life with a 1000x volume compression in 100 microseconds. If near adiabatic compression is achieved, the final plasma of 1e26 m-3, 10keV, 700 Tesla, 2 cm radius, confined for 10 μsec would produce interesting fusion energy gain. General Fusion (GF) is developing an acoustic compression system using pneumatic pistons focusing a shock wave on the CT plasma in the center of a 3 m diameter sphere filled with liquid lead-lithium. Low cost driver, straightforward heat extraction, good tritium breeding ratio and excellent neutron protection could lead to a practical power plant. GF (65 employees) has an active plasma R&D program including both full scale and reduced scale plasma experiments and simulation of both. Although acoustic driven compression of full scale plasmas is the end goal, present compression studies use reduced scale plasmas and chemically accelerated Aluminum liners. We will review results from our plasma target development, motivate and review the results of dynamic compression field tests and briefly describe the work to date on the acoustic driver front.

  9. Single-electron transport driven by surface acoustic waves: Moving quantum dots versus short barriers

    DEFF Research Database (Denmark)

    Utko, Pawel; Hansen, Jørn Bindslev; Lindelof, Poul Erik;


    We have investigated the response of the acoustoelectric-current driven by a surface-acoustic wave through a quantum point contact in the closed-channel regime. Under proper conditions, the current develops plateaus at integer multiples of ef when the frequency f of the surface-acoustic wave or t...

  10. Filamentation instability of current-driven dust ion-acoustic waves in a collisional dusty plasma

    Energy Technology Data Exchange (ETDEWEB)

    Niknam, A. R. [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran 19839-63113 (Iran, Islamic Republic of); Haghtalab, T.; Khorashadizadeh, S. M. [Physics Department, Birjand University, Birjand 97179-63384 (Iran, Islamic Republic of)


    A theoretical investigation has been made of the dust ion-acoustic filamentation instability in an unmagnetized current-driven dusty plasma by using the Lorentz transformation formulas. The effect of collision between the charged particles with neutrals and their thermal motion on this instability is considered. Developing the filamentation instability of the current-driven dust ion-acoustic wave allows us to determine the period and the establishment time of the filamentation structure and threshold for instability development.

  11. Acoustic instability driven by cosmic-ray streaming (United States)

    Begelman, Mitchell C.; Zweibel, Ellen G.


    We study the linear stability of compressional waves in a medium through which cosmic rays stream at the Alfven speed due to strong coupling with Alfven waves. Acoustic waves can be driven unstable by the cosmic-ray drift, provided that the streaming speed is sufficiently large compared to the thermal sound speed. Two effects can cause instability: (1) the heating of the thermal gas due to the damping of Alfven waves driven unstable by cosmic-ray streaming; and (2) phase shifts in the cosmic-ray pressure perturbation caused by the combination of cosmic-ray streaming and diffusion. The instability does not depend on the magnitude of the background cosmic-ray pressure gradient, and occurs whether or not cosmic-ray diffusion is important relative to streaming. When the cosmic-ray pressure is small compared to the gas pressure, or cosmic-ray diffusion is strong, the instability manifests itself as a weak overstability of slow magnetosonic waves. Larger cosmic-ray pressure gives rise to new hybrid modes, which can be strongly unstable in the limits of both weak and strong cosmic-ray diffusion and in the presence of thermal conduction. Parts of our analysis parallel earlier work by McKenzie & Webb (which were brought to our attention after this paper was accepted for publication), but our treatment of diffusive effects, thermal conduction, and nonlinearities represent significant extensions. Although the linear growth rate of instability is independent of the background cosmic-ray pressure gradient, the onset of nonlinear eff ects does depend on absolute value of DEL (vector differential operator) P(sub c). At the onset of nonlinearity the fractional amplitude of cosmic-ray pressure perturbations is delta P(sub C)/P(sub C) approximately (kL) (exp -1) much less than 1, where k is the wavenumber and L is the pressure scale height of the unperturbed cosmic rays. We speculate that the instability may lead to a mode of cosmic-ray transport in which plateaus of uniform cosmic

  12. Surface-acoustic-wave-driven luminescence from a lateral p-n junction (United States)

    Gell, J. R.; Atkinson, P.; Bremner, S. P.; Sfigakis, F.; Kataoka, M.; Anderson, D.; Jones, G. A. C.; Barnes, C. H. W.; Ritchie, D. A.; Ward, M. B.; Norman, C. E.; Shields, A. J.


    The authors report surface-acoustic-wave-driven luminescence from a lateral p-n junction formed by molecular beam epitaxy regrowth of a modulation doped GaAs /AlGaAs quantum well on a patterned GaAs substrate. Surface-acoustic-wave-driven transport is demonstrated by peaks in the electrical current and light emission from the GaAs quantum well at the resonant frequency of the transducer. This type of junction offers high carrier mobility and scalability. The demonstration of surface-acoustic-wave luminescence is a significant step towards single-photon applications in quantum computation and quantum cryptography.

  13. Open Air Laboratories (OPAL): A community-driven research programme

    Energy Technology Data Exchange (ETDEWEB)

    Davies, L., E-mail: [Imperial College London, London SW7 2AZ (United Kingdom); Bell, J.N.B.; Bone, J.; Head, M.; Hill, L. [Imperial College London, London SW7 2AZ (United Kingdom); Howard, C. [Natural History Museum, London SW7 5BD (United Kingdom); Hobbs, S.J. [Environment Department, University of York, Heslington, York YO10 5DD (United Kingdom); Jones, D.T. [Imperial College London, London SW7 2AZ (United Kingdom); Natural History Museum, London SW7 5BD (United Kingdom); Power, S.A. [Imperial College London, London SW7 2AZ (United Kingdom); Rose, N. [Department of Geography, University College London, London WC1E 6BT (United Kingdom); Ryder, C.; Seed, L. [Imperial College London, London SW7 2AZ (United Kingdom); Stevens, G. [Natural History Museum, London SW7 5BD (United Kingdom); Toumi, R.; Voulvoulis, N. [Imperial College London, London SW7 2AZ (United Kingdom); White, P.C.L. [Environment Department, University of York, Heslington, York YO10 5DD (United Kingdom)


    OPAL is an English national programme that takes scientists into the community to investigate environmental issues. Biological monitoring plays a pivotal role covering topics of: i) soil and earthworms; ii) air, lichens and tar spot on sycamore; iii) water and aquatic invertebrates; iv) biodiversity and hedgerows; v) climate, clouds and thermal comfort. Each survey has been developed by an inter-disciplinary team and tested by voluntary, statutory and community sectors. Data are submitted via the web and instantly mapped. Preliminary results are presented, together with a discussion on data quality and uncertainty. Communities also investigate local pollution issues, ranging from nitrogen deposition on heathlands to traffic emissions on roadside vegetation. Over 200,000 people have participated so far, including over 1000 schools and 1000 voluntary groups. Benefits include a substantial, growing database on biodiversity and habitat condition, much from previously unsampled sites particularly in urban areas, and a more engaged public. - Highlights: > Environmental research conducted jointly by the public and scientists. > Over 200,000 people involved, 8000 sites surveyed, uncertainty minimised. > New insights into urban pollution. > A more engaged and informed society. - Research is enriched where the public and scientists work together.

  14. Pulse Compression by Filamentation in Argon with an Acoustic Optical Programmable Dispersive Filter for Predispersion Compensation

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-Wei; JIANG Yong-Liang; LENG Yu-Xin; LIU Jun; GE Xiao-Chun; LI Ru-Xin; XU Zhi-Zhan


    @@ We have experimentally demonstrated pulses 0.4 mJ in duration smaller than 12 fs with an excellent spatial beam profile by self-guided propagation in argon. The original 52fs pulses from the chirped pulsed amplification laser system are first precompressed to 32 fs by inserting an acoustic optical programmable dispersive filter instrument into the laser system for spectrum reshaping and dispersion compensation, and the pulse spectrum is subsequently broadened by filamentation in an argon cell. By using chirped mirrors for post-dispersion compensation, the pulses are successfully compressed to smaller than 12fs.

  15. Thermal convection driven by acoustic field under microgravity


    Tanabe, Mitsuaki; 田辺 光昭


    Natural convection is suppressed in space environment due to the weightlessness. Only centrifugal force is utilized currently to drive gas-phase thermal convection in space. This paper presents an alternative way to drive thermal convection. From the investigation of combustion oscillation in rocket motors, a new thermal convection had been found in stationary acoustic fields. Analyzing the phenomena, acoustic radiation force is found to be the candidate driving force. With a simplified syste...

  16. Numerical study of acoustophoretic motion of particles in a PDMS microchannel driven by surface acoustic waves. (United States)

    Nama, Nitesh; Barnkob, Rune; Mao, Zhangming; Kähler, Christian J; Costanzo, Francesco; Huang, Tony Jun


    We present a numerical study of the acoustophoretic motion of particles suspended in a liquid-filled PDMS microchannel on a lithium niobate substrate acoustically driven by surface acoustic waves. We employ a perturbation approach where the flow variables are divided into first- and second-order fields. We use impedance boundary conditions to model the PDMS microchannel walls and we model the acoustic actuation by a displacement function from the literature based on a numerical study of piezoelectric actuation. Consistent with the type of actuation, the obtained first-order field is a horizontal standing wave that travels vertically from the actuated wall towards the upper PDMS wall. This is in contrast to what is observed in bulk acoustic wave devices. The first-order fields drive the acoustic streaming, as well as the time-averaged acoustic radiation force acting on suspended particles. We analyze the motion of suspended particles driven by the acoustic streaming drag and the radiation force. We examine a range of particle diameters to demonstrate the transition from streaming-drag-dominated acoustophoresis to radiation-force-dominated acoustophoresis. Finally, as an application of our numerical model, we demonstrate the capability to tune the position of the vertical pressure node along the channel width by tuning the phase difference between two incoming surface acoustic waves.

  17. Mixing high-viscosity fluids via acoustically driven bubbles (United States)

    Orbay, Sinem; Ozcelik, Adem; Lata, James; Kaynak, Murat; Wu, Mengxi; Huang, Tony Jun


    We present an acoustofluidic micromixer which can perform rapid and homogeneous mixing of highly viscous fluids in the presence of an acoustic field. In this device, two high-viscosity polyethylene glycol (PEG) solutions were co-injected into a three-inlet PDMS microchannel with the center inlet containing a constant stream of nitrogen flow which forms bubbles in the device. When these bubbles were excited by an acoustic field generated via a piezoelectric transducer, the two solutions mixed homogenously due to the combination of acoustic streaming, droplet ejection, and bubble eruption effects. The mixing efficiency of this acoustofluidic device was evaluated using PEG-700 solutions which are ~106 times more viscous than deionized (DI) water. Our results indicate homogenous mixing of the PEG-700 solutions with a ~0.93 mixing index. The acoustofluidic micromixer is compact, inexpensive, easy to operate, and has the capacity to mix highly viscous fluids within 50 ms.

  18. Temporal characteristics of surface-acoustic-wave-driven luminescence from a lateral p-n junction (United States)

    Gell, J. R.; Ward, M. B.; Shields, A. J.; Atkinson, P.; Bremner, S. P.; Anderson, D.; Kataoka, M.; Barnes, C. H. W.; Jones, G. A. C.; Ritchie, D. A.


    Short radio frequency pulses were used to study the surface-acoustic-wave-driven light emission from a molecular beam epitaxy regrown GaAs /AlGaAs lateral p-n junction. The luminescence provides a fast probe of the signals arriving at the junction allowing the authors to temporally separate the effect of the surface-acoustic-wave from pickup of the free space electromagnetic wave. Oscillations in the light intensity are resolved at the resonant frequency of the transducer, suggesting that the surface-acoustic-wave is transporting electrons across the junction in packets.

  19. Solar wind driven dust acoustic instability with Lorentzian kappa distribution

    Energy Technology Data Exchange (ETDEWEB)

    Arshad, Kashif [National Center for Physics (NCP), Quaid-i-Azam University Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan); Pakistan Institute of Engineering and Applied Sciences, P.O. Nilore, Islamabad and University of Wah, Wah Cantt 47040 (Pakistan); Ehsan, Zahida, E-mail: [National Center for Physics (NCP), Quaid-i-Azam University Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan); Universita degli Studi del Molise, 86090 Pesche - IS (Italy); INFN Sezione di Napoli, 80126 Napoli (Italy); Department of Physics, COMSATS Institute of Information Technology (CIIT), Defence Road, Off Raiwind Road, Lahore 86090 (Pakistan); Khan, S. A. [National Center for Physics (NCP), Quaid-i-Azam University Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan); Mahmood, S. [Theoretical Plasma Physics Division, PINSTEC, PO Box Nilore, Islamabad 44000 (Pakistan)


    In a three species electron-ion-dust plasma following a generalized non-Maxwellian distribution function (Lorentzian or kappa), it is shown that a kinetic instability of dust-acoustic mode exists. The instability threshold is affected when such (quasineutral) plasma permeates through another static plasma. Such case is of interest when the solar wind is streaming through the cometary plasma in the presence of interstellar dust. In the limits of phase velocity of the waves larger and smaller than the thermal velocity of dust particles, the dispersion properties and growth rate of dust-acoustic mode are investigated analytically with validation via numerical analysis.

  20. Different quantization mechanisms in single-electron pumps driven by surface acoustic waves

    DEFF Research Database (Denmark)

    Utko, P.; Gloos, K.; Hansen, Jørn Bindslev


    We have studied the acoustoelectric current in single-electron pumps driven by surface acoustic waves. We have found that in certain parameter ranges two different sets of quantized steps dominate the acoustoelectric current versus gate-voltage characteristics. In some cases, both types of quanti......We have studied the acoustoelectric current in single-electron pumps driven by surface acoustic waves. We have found that in certain parameter ranges two different sets of quantized steps dominate the acoustoelectric current versus gate-voltage characteristics. In some cases, both types...

  1. Preliminary design of an advanced programmable digital filter network for large passive acoustic ASW systems. [Parallel processor

    Energy Technology Data Exchange (ETDEWEB)

    McWilliams, T.; Widdoes, Jr., L. C.; Wood, L.


    The design of an extremely high performance programmable digital filter of novel architecture, the LLL Programmable Digital Filter, is described. The digital filter is a high-performance multiprocessor having general purpose applicability and high programmability; it is extremely cost effective either in a uniprocessor or a multiprocessor configuration. The architecture and instruction set of the individual processor was optimized with regard to the multiple processor configuration. The optimal structure of a parallel processing system was determined for addressing the specific Navy application centering on the advanced digital filtering of passive acoustic ASW data of the type obtained from the SOSUS net. 148 figures. (RWR)

  2. Perceptually-Driven Signal Analysis for Acoustic Event Classification (United States)


    study of musical timbre . Defined as "the subjective attribute of sound which differentiates two or more sounds that have the same loudness, pitch and...therefore a better estimate of the likelihood function. 56 Bibliography [1] J. M. Grey, -AMultidimensional perceptual scaling of musical timbres ...Display, 2005. [10] J. M. Grey, "Perceptual effects of spectral modifications on musical timbres ," Journal of the Acoustical Society of America, vol. 63

  3. Current-less solar wind driven dust acoustic instability in cometary plasma

    Energy Technology Data Exchange (ETDEWEB)

    Vranjes, J. [Belgian Institute for Space Aeronomy, Ringlaan 3, 1180 Brussels (Belgium)


    A quantitative analysis is presented of the dust acoustic wave instability driven by the solar and stellar winds. This is a current-less kinetic instability which develops in permeating plasmas, i.e.., when one quasi-neutral electron-ion wind plasma in its propagation penetrates through another quasi-neutral plasma which contains dust, electrons, and ions.

  4. Filamentation instability of nonextensive current-driven plasma in the ion acoustic frequency range

    Energy Technology Data Exchange (ETDEWEB)

    Khorashadizadeh, S. M., E-mail:; Rastbood, E. [Physics Department of Birjand University, Birjand (Iran, Islamic Republic of); Niknam, A. R., E-mail: [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran (Iran, Islamic Republic of)


    The filamentation and ion acoustic instabilities of nonextensive current-driven plasma in the ion acoustic frequency range have been studied using the Lorentz transformation formulas. Based on the kinetic theory, the possibility of filamentation instability and its growth rate as well as the ion acoustic instability have been investigated. The results of the research show that the possibility and growth rate of these instabilities are significantly dependent on the electron nonextensive parameter and drift velocity. Besides, the increase of electrons nonextensive parameter and drift velocity lead to the increase of the growth rates of both instabilities. In addition, the wavelength region in which the filamentation instability occurs is more stretched in the presence of higher values of drift velocity and nonextensive parameter. Finally, the results of filamentation and ion acoustic instabilities have been compared and the conditions for filamentation instability to be dominant mode of instability have been presented.

  5. A model for an acoustically driven microbubble inside a rigid tube

    KAUST Repository

    Qamar, Adnan


    A theoretical framework to model the dynamics of acoustically driven microbubble inside a rigid tube is presented. The proposed model is not a variant of the conventional Rayleigh-Plesset category of models. It is derived from the reduced Navier-Stokes equation and is coupled with the evolving flow field solution inside the tube by a similarity transformation approach. The results are computed, and compared with experiments available in literature, for the initial bubble radius of Ro=1.5μm and 2μm for the tube diameter of D=12μm and 200μm with the acoustic parameters as utilized in the experiments. Results compare quite well with the existing experimental data. When compared to our earlier basic model, better agreement on a larger tube diameter is obtained with the proposed coupled model. The model also predicts, accurately, bubble fragmentation in terms of acoustic and geometric parameters.

  6. Temporal isolation of surface-acoustic-wave-driven luminescence from a lateral p n junction using pulsed techniques (United States)

    Gell, J. R.; Ward, M. B.; Atkinson, P.; Bremner, S. P.; Anderson, D.; Norman, C. E.; Kataoka, M.; Barnes, C. H. W.; Jones, G. A. C.; Shields, A. J.; Ritchie, D. A.


    The authors report surface-acoustic-wave-driven luminescence from a lateral p-n junction formed by molecular-beam epitaxy regrowth of a modulation doped GaAs/AlGaAs quantum well on a patterned GaAs substrate. Pulsed techniques are used to isolate the surface-acoustic-wave-driven emission from any emission due to pick-up of the free-space electromagnetic wave. The luminescence provides a fast probe of the signals arriving at the p-n junction allowing the response of the junction to the surface-acoustic-wave to be studied in the time domain. Oscillations in the surface-acoustic-wave-driven component of the light intensity are resolved at the resonant frequency of the transducer, suggesting that the surface-acoustic-wave is transporting electrons across the junction in packets.

  7. Microfluidic pumping through miniaturized channels driven by ultra-high frequency surface acoustic waves

    Energy Technology Data Exchange (ETDEWEB)

    Shilton, Richie J., E-mail: [Center for Nanotechnology Innovation @ NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa (Italy); Travagliati, Marco [Center for Nanotechnology Innovation @ NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa (Italy); NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12, 56127 Pisa (Italy); Beltram, Fabio [NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12, 56127 Pisa (Italy); Center for Nanotechnology Innovation @ NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa (Italy); Cecchini, Marco, E-mail: [NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12, 56127 Pisa (Italy)


    Surface acoustic waves (SAWs) are an effective means to pump fluids through microchannel arrays within fully portable systems. The SAW-driven acoustic counterflow pumping process relies on a cascade phenomenon consisting of SAW transmission through the microchannel, SAW-driven fluid atomization, and subsequent coalescence. Here, we investigate miniaturization of device design, and study both SAW transmission through microchannels and the onset of SAW-driven atomization up to the ultra-high-frequency regime. Within the frequency range from 47.8 MHz to 754 MHz, we show that the acoustic power required to initiate SAW atomization remains constant, while transmission through microchannels is most effective when the channel widths w ≳ 10 λ, where λ is the SAW wavelength. By exploiting the enhanced SAW transmission through narrower channels at ultra-high frequencies, we discuss the relevant frequency-dependent length scales and demonstrate the scaling down of internal flow patterns and discuss their impact on device miniaturization strategies.

  8. Research Programme for the 660 Mev Proton Accelerator Driven MOX-Plutonium Subcritical Assembly

    CERN Document Server

    Barashenkov, V S; Buttseva, G L; Dudarev, S Yu; Polanski, A; Puzynin, I V; Sissakian, A N


    The paper presents a research programme of the Experimental Acclerator Driven System (ADS), which employs a subcritical assembly and a 660 MeV proton acceletator operating at the Laboratory of Nuclear Problems of the JINR, Dubna. MOX fuel (25% PuO_2 + 75% UO_2) designed for the BN-600 reactor use will be adopted for the core of the assembly. The present conceptual design of the experimental subcritical assembly is based on a core of a nominal unit capacity of 15 kW (thermal). This corresponds to the multiplication coefficient k_eff = 0.945, energetic gain G = 30 and the accelerator beam power 0.5 kW.

  9. Heat release and flame structure measurements of self-excited acoustically-driven premixed methane flames

    Energy Technology Data Exchange (ETDEWEB)

    Kopp-Vaughan, Kristin M.; Tuttle, Steven G.; Renfro, Michael W. [Department of Mechanical Engineering, University of Connecticut, 191 Auditorium Rd, U-3139, Storrs, CT 06269 (United States); King, Galen B. [School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907 (United States)


    An open-open organ pipe burner (Rijke tube) with a bluff-body ring was used to create a self-excited, acoustically-driven, premixed methane-air conical flame, with equivalence ratios ranging from 0.85 to 1.05. The feed tube velocities corresponded to Re = 1780-4450. Coupled oscillations in pressure, velocity, and heat release from the flame are naturally encouraged at resonant frequencies in the Rijke tube combustor. This coupling creates sustainable self-excited oscillations in flame front area and shape. The period of the oscillations occur at the resonant frequency of the combustion chamber when the flame is placed {proportional_to}1/4 of the distance from the bottom of the tube. In this investigation, the shape of these acoustically-driven flames is measured by employing both OH planar laser-induced fluorescence (PLIF) and chemiluminescence imaging and the images are correlated to simultaneously measured pressure in the combustor. Past research on acoustically perturbed flames has focused on qualitative flame area and heat release relationships under imposed velocity perturbations at imposed frequencies. This study reports quantitative empirical fits with respect to pressure or phase angle in a self-generated pressure oscillation. The OH-PLIF images were single temporal shots and the chemiluminescence images were phase averaged on chip, such that 15 exposures were used to create one image. Thus, both measurements were time resolved during the flame oscillation. Phase-resolved area and heat release variations throughout the pressure oscillation were computed. A relation between flame area and the phase angle before the pressure maximum was derived for all flames in order to quantitatively show that the Rayleigh criterion was satisfied in the combustor. Qualitative trends in oscillating flame area were found with respect to feed tube flow rates. A logarithmic relation was found between the RMS pressure and both the normalized average area and heat release rate

  10. Distributions of the high temperature and the high pressure inside a single acoustically driven bubble

    Institute of Scientific and Technical Information of China (English)

    应崇福; 安宇


    The physical circumstances inside an acoustically driven single gas bubble in water has been intensively explored during the past few years. Starting from the results obtained for a typical case in a well known early paper (Wu, C. C., Roberts, P. H., Phys. Rev. Lett., 1993, 70(22): 3424) and introducing successively several corrections to the physical model, this paper computes in corresponding order the temporal and spatial distributions of significant physical parameters, including the temperature and the pressure, in the bubble around the moment of the bubble's violent collapse, until expectations in consistence with the present points of view are procured. For the peak temperature our results agree with the prevailing belief that in a typical stable single bubble it is of the order of ten thousand degrees.

  11. A novel coupling configuration for thermoacoustically-driven pulse tube coolers: Acoustic amplifier

    Institute of Scientific and Technical Information of China (English)

    DAI Wei; LUO Ercang; HU Jianying; CHEN Yanyan


    Thermoacoustically-driven pulse tube cooler can provide cryogenic cooling power with no moving components. Up to now, pulse tube cooler is directly coupled with the thermoacoustic engine and obtainable pressure ratio for the pulse tube cooler is limited by the capability of the thermoacoustic engine. The authors propose here the concept of acoustic amplifier, which is actually a long tube connecting the engine with the pulse tube cooler. Theoretical calculation shows that suitable length and diameter of the tube can lead to a pressure wave amplification effect which means that pressure wave amplitude coming from the thermoacoustic engine can be much amplified to drive the pulse tube cooler. Based on this, a 2.8 m long copper tube with 8 mm inner diameter is used as the acoustic amplifier in experiments. The experimental results show that due to the amplification effect, pressure wave amplitude at the inlet of the pulse tube cooler is over 2.5 times of that at the engine outlet. Typically, with 1.67 kW heating power, the pressure ratio provided by the engine is 1.11 while at the inlet of the pulse tube cooler the pressure ratio is 1.32, which leads to a lowest no-load temperature of 65.7 K.

  12. Numerical simulation of 3D boundary-driven acoustic streaming in microfluidic devices. (United States)

    Lei, Junjun; Hill, Martyn; Glynne-Jones, Peter


    This article discusses three-dimensional (3D) boundary-driven streaming in acoustofluidic devices. Firstly, the 3D Rayleigh streaming pattern in a microchannel is simulated and its effect on the movement of microparticles of various sizes is demonstrated. The results obtained from this model show good comparisons with 3D experimental visualisations and demonstrate the fully 3D nature of the acoustic streaming field and the associated acoustophoretic motion of microparticles in acoustofluidic devices. This method is then applied to another acoustofluidic device in order to gain insights into an unusual in-plane streaming pattern. The origin of this streaming has not been fully described and its characteristics cannot be explained from the classical theory of Rayleigh streaming. The simulated in-plane streaming pattern was in good agreement with the experimental visualisation. The mechanism behind it is shown to be related to the active sound intensity field, which supports our previous findings on the mechanism of the in-plane acoustic streaming pattern visualised and modelled in a thin-layered capillary device.

  13. Periodic shock-emission from acoustically driven cavitation clouds: a source of the subharmonic signal. (United States)

    Johnston, Keith; Tapia-Siles, Cecilia; Gerold, Bjoern; Postema, Michiel; Cochran, Sandy; Cuschieri, Alfred; Prentice, Paul


    Single clouds of cavitation bubbles, driven by 254kHz focused ultrasound at pressure amplitudes in the range of 0.48-1.22MPa, have been observed via high-speed shadowgraphic imaging at 1×10(6) frames per second. Clouds underwent repetitive growth, oscillation and collapse (GOC) cycles, with shock-waves emitted periodically at the instant of collapse during each cycle. The frequency of cloud collapse, and coincident shock-emission, was primarily dependent on the intensity of the focused ultrasound driving the activity. The lowest peak-to-peak pressure amplitude of 0.48MPa generated shock-waves with an average period of 7.9±0.5μs, corresponding to a frequency of f0/2, half-harmonic to the fundamental driving. Increasing the intensity gave rise to GOC cycles and shock-emission periods of 11.8±0.3, 15.8±0.3, 19.8±0.2μs, at pressure amplitudes of 0.64, 0.92 and 1.22MPa, corresponding to the higher-order subharmonics of f0/3, f0/4 and f0/5, respectively. Parallel passive acoustic detection, filtered for the fundamental driving, revealed features that correlated temporally to the shock-emissions observed via high-speed imaging, p(two-tailed) subharmonic spectral peaks, in the frequency domain. The larger cavitation clouds (>200μm diameter, at maximum inflation), that developed under insonations of peak-to-peak pressure amplitudes >1.0MPa, emitted shock-waves with two or more fronts suggesting non-uniform collapse of the cloud. The observations indicate that periodic shock-emissions from acoustically driven cavitation clouds provide a source for the cavitation subharmonic signal, and that shock structure may be used to study intra-cloud dynamics at sub-microsecond timescales.

  14. A programmable acoustic stimuli and auditory evoked potential measurement system for objective tinnitus diagnosis research. (United States)

    Ku, Yunseo; Ahn, Joong Woo; Kwon, Chiheon; Suh, Myung-Whan; Lee, Jun Ho; Oh, Seung Ha; Kim, Hee Chan


    This paper presents the development of a single platform that records auditory evoked potential synchronized to specific acoustic stimuli of the gap prepulse inhibition method for objective tinnitus diagnosis research. The developed system enables to program various parameters of the generated acoustic stimuli. Moreover, only by simple filter modification, the developed system provides high flexibility to record not only short latency auditory brainstem response but also late latency auditory cortical response. The adaptive weighted averaging algorithm to minimize the time required for the experiment is also introduced. The results show that the proposed algorithm can reduce the number of the averaging repetitions to 70% compared with conventional ensemble averaging method.


    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Rodrigo; Socrates, Aristotle [Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States)


    We examine the nonlinear development of unstable magnetosonic waves driven by a background radiative flux-the radiation-driven magneto-acoustic instability (RMI, a.k.a. the ''photon bubble'' instability). The RMI may serve as a persistent source of density, radiative flux, and magnetic field fluctuations in stably stratified, optically thick media. The conditions for instability are present in a variety of astrophysical environments and do not require the radiation pressure to dominate or the magnetic field to be strong. Here, we numerically study the saturation properties of the RMI, covering three orders of magnitude in the relative strength of radiation, magnetic field, and gas energies. Two-dimensional, time-dependent radiation-magnetohydrodynamic simulations of local, stably stratified domains are conducted with Zeus-MP in the optically thick, highly conducting limit. Our results confirm the theoretical expectations of Blaes and Socrates in that the RMI operates even in gas-pressure-dominated environments that are weakly magnetized. The saturation amplitude is a monotonically increasing function of the ratio of radiation to gas pressure. Keeping this ratio constant, we find that the saturation amplitude peaks when the magnetic pressure is comparable to the radiation pressure. We discuss the implications of our results for the dynamics of magnetized stellar envelopes, where the RMI should act as a source of sub-photospheric perturbations.

  16. Nonlinear Evolution of the Radiation-Driven Magneto-Acoustic Instability (RMI)

    CERN Document Server

    Fernández, Rodrigo


    We examine the nonlinear development of unstable magnetosonic waves driven by a background radiative flux -- the Radiation-Driven Magneto-Acoustic Instability (RMI, a.k.a. the "photon bubble" instability). The RMI may serve as a persistent source of density, radiative flux, and magnetic field fluctuations in stably-stratified, optically-thick media. The conditions for instability are present in a variety of astrophysical environments, and do not require the radiation pressure to dominate or the magnetic field to be strong. Here we numerically study the saturation properties of the RMI, covering three orders of magnitude in the relative strength of radiation, magnetic field, and gas energies. Two-dimensional, time-dependent radiation-MHD simulations of local, stably-stratified domains are conducted with Zeus-MP in the optically-thick, highly-conducting limit. Our results confirm the theoretical expectations of Blaes and Socrates (2003) in that the RMI operates even in gas pressure-dominated environments that a...

  17. A numerical study of microparticle acoustophoresis driven by acoustic radiation forces and streaming-induced drag forces

    DEFF Research Database (Denmark)

    Muller, Peter Barkholt; Barnkob, Rune; Jensen, Mads Jakob Herring;


    We present a numerical study of the transient acoustophoretic motion of microparticles suspended in a liquid-filled microchannel and driven by the acoustic forces arising from an imposed standing ultrasound wave: the acoustic radiation force from the scattering of sound waves on the particles...... parameters using a numerical particle-tracking scheme. The model shows the transition in the acoustophoretic particle motion from being dominated by streaming-induced drag to being dominated by radiation forces as a function of particle size, channel geometry, and material properties....

  18. Numerical analysis of acoustically driven viscous flow through a circular hole (United States)

    Notomi, Tetsuo; Namba, Masanobu


    Periodic viscous flows through a circular hole driven by fluctuating far field pressure are numerically studied. The time-dependent incompressible Navier-Stokes equations formulated with orthogonal curvilinear coordinates are solved by using a finite difference method. The flow patterns are classified into three regimes by fluctuating pressure amplitude and frequency: flows with no laminar separation (high frequency-low pressure range), flows with attached separation bubble (intermediate frequency and pressure range) and flows with detached vortex ring (low frequency-high pressure range). The flow resistance of the circular hole is proportional to the acoustic particle velocity but independent of the viscosity of the fluid and almost invariant with the frequency for the low frequency-high pressure range. On the other hand, for the high frequency-low pressure range, the flow resistance is independent of the periodic pressure amplitude and varies directly with 2/3 powers of frequency. Finally, the predicted circular hole impedance is in good agreement with Ingard and Ising's (1967) experimental data for the orifice impedance.

  19. Energetic particle driven geodesic acoustic mode in a toroidally rotating tokamak plasma (United States)

    Ren, Haijun


    Energetic particle (EP) driven geodesic acoustic modes (EGAMs) in toroidally rotating tokamak plasmas are analytically investigated using the hybrid kinetic-fluid model and gyrokinetic equations. By ignoring high-order terms and ion Landau damping, the kinetic dispersion relation is reduced to the hybrid one in the large safety factor limit. There is one high-frequency branch with a frequency larger than {ωt0} , the transit frequency of EPs with initial energy, which is always stable. Two low-frequency solutions with a frequency smaller than {ωt0} are complex conjugates in the hybrid limit. In the presence of ion Landau damping, the growth rate of the unstable branch is decreased and the damping rate of the damped branch is increased. The toroidal Mach number is shown to increase {{ Ω }\\text{r}} , the normalized real frequency of both branches. Although not affecting the instability critical condition, the Mach number decreases the growth rate when {{ Ω }\\text{r}} is larger than a critical value Ω \\text{r}\\text{cri} and enlarges the growth rate when {{ Ω }\\text{r}}Landau damping effect is negligible for large M. But the discrepancy between the kinetic dispersion relation and the hybrid one becomes ignorable only for q≳ 7 .

  20. An evaluation of a Canadian peer-driven injury prevention programme for high-risk adolescents. (United States)

    Tenn, L; Dewis, M E


    The mortality and morbidity resulting from serious trauma in adolescence, particularly head and spinal cord injury, constitutes a health problem of major proportions. Although many community-based prevention programmes have been reported in this last decade, few of these describe an evaluation component. In this study, a school-based prevention programme was developed by a peer group and presented by them to high-risk adolescents. The study aimed to test the efficacy of this intervention compared to the delivery of a prevention presentation to a similar group by a health care professional and compared to a control group. Measures of health locus of control, self-efficacy and behavioural intent were supplemented by open-ended items related to risk-taking behaviour change. At post-test and at 4-month follow-up, there was little evidence in the quantitative measures to support the effectiveness of the intervention for reducing injury risk factors. More encouraging findings were seen in the qualitative data. Explanations for why the intervention did not result in the expected outcomes are offered.

  1. Thermal and fluid dynamic analysis of partially premixed turbulent combustion driven by thermo acoustic effects

    NARCIS (Netherlands)

    Shahi, M.; Kok, J.B.W.; Pozarlik, A.K.; Sponfeldner, Thomas; Malcolm, M.J.; Pawelczyk, M.; Paosawatyangyong, B.


    Thermo-acoustic instability can be caused by the feedback mechanism between unsteady heat release, acoustic oscillations and flow perturbations. In a gas turbine combustor limit cycles of pressure oscillations at elevated temperatures generated by the unstable combustion process enhance the structur

  2. High amplitude nonlinear acoustic wave driven flow fields in cylindrical and conical resonators. (United States)

    Antao, Dion Savio; Farouk, Bakhtier


    A high fidelity computational fluid dynamic model is used to simulate the flow, pressure, and density fields generated in a cylindrical and a conical resonator by a vibrating end wall/piston producing high-amplitude standing waves. The waves in the conical resonator are found to be shock-less and can generate peak acoustic overpressures that exceed the initial undisturbed pressure by two to three times. A cylindrical (consonant) acoustic resonator has limitations to the output response observed at one end when the opposite end is acoustically excited. In the conical geometry (dissonant acoustic resonator) the linear acoustic input is converted to high energy un-shocked nonlinear acoustic output. The model is validated using past numerical results of standing waves in cylindrical resonators. The nonlinear nature of the harmonic response in the conical resonator system is further investigated for two different working fluids (carbon dioxide and argon) operating at various values of piston amplitude. The high amplitude nonlinear oscillations observed in the conical resonator can potentially enhance the performance of pulse tube thermoacoustic refrigerators and these conical resonators can be used as efficient mixers.

  3. 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.

  4. A programmable and configurable multi-port System-on-Chip for stimulating electrokinetically-driven microfluidic devices. (United States)

    Lopez, Martha Salome; Gerstlauer, Andreas; Avila, Alfonso; Martinez-Chapa, Sergio O


    Recent research has demonstrated the use of microfluidic devices and electro-kinetics in areas such as medicine, genetics, embryology, epidemiology and pollution analysis, where manipulation of particles suspended in liquid media is required. Micro-fabrication technology has made it possible to increase system complexity and functionality by allowing integration of different processing and analysis stages in a single chip. However, fully integrated and autonomous microfluidic systems supporting ad-hoc stimulation have yet to be developed. This paper presents a flexible, configurable and programmable stimulator for electro-kinetically driven microfluidic devices. The stimulator is a dedicated System-on-Chip (SoC) architecture that generates sine, triangle, and sawtooth signals within a frequency range of 1 Hz to 20 MHz, capable of delivering single, dual, and superimposed waveforms, in a user defined test sequence for a selected time period. The system is designed to be integrated into complete, autonomous Lab-on-Chip, portable or implantable devices. As such, it is expected to help significantly advance current and future research on particle manipulation.

  5. Subharmonic generation, chaos, and subharmonic resurrection in an acoustically driven fluid-filled cavity. (United States)

    Cantrell, John H; Adler, Laszlo; Yost, William T


    Traveling wave solutions of the nonlinear acoustic wave equation are obtained for the fundamental and second harmonic resonances of a fluid-filled cavity. The solutions lead to the development of a non-autonomous toy model for cavity oscillations. Application of the Melnikov method to the model equation predicts homoclinic bifurcation of the Smale horseshoe type leading to a cascade of period doublings with increasing drive displacement amplitude culminating in chaos. The threshold value of the drive displacement amplitude at tangency is obtained in terms of the acoustic drive frequency and fluid attenuation coefficient. The model prediction of subharmonic generation leading to chaos is validated from acousto-optic diffraction measurements in a water-filled cavity using a 5 MHz acoustic drive frequency and from the measured frequency spectrum in the bifurcation cascade regime. The calculated resonant threshold amplitude of 0.2 nm for tangency is consistent with values estimated for the experimental set-up. Experimental evidence for the appearance of a stable subharmonic beyond chaos is reported.

  6. Subharmonic generation, chaos, and subharmonic resurrection in an acoustically driven fluid-filled cavity

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, John H., E-mail:; Yost, William T. [NASA Langley Research Center, Research Directorate, Hampton, Virginia 23681 (United States); Adler, Laszlo [Adler Consultants, Inc./Ohio State University, Columbus, Ohio 43210 (United States)


    Traveling wave solutions of the nonlinear acoustic wave equation are obtained for the fundamental and second harmonic resonances of a fluid-filled cavity. The solutions lead to the development of a non-autonomous toy model for cavity oscillations. Application of the Melnikov method to the model equation predicts homoclinic bifurcation of the Smale horseshoe type leading to a cascade of period doublings with increasing drive displacement amplitude culminating in chaos. The threshold value of the drive displacement amplitude at tangency is obtained in terms of the acoustic drive frequency and fluid attenuation coefficient. The model prediction of subharmonic generation leading to chaos is validated from acousto-optic diffraction measurements in a water-filled cavity using a 5 MHz acoustic drive frequency and from the measured frequency spectrum in the bifurcation cascade regime. The calculated resonant threshold amplitude of 0.2 nm for tangency is consistent with values estimated for the experimental set-up. Experimental evidence for the appearance of a stable subharmonic beyond chaos is reported.

  7. High-speed imaging of an ultrasound-driven bubble in contact with a wall: " Narcissus" effect and resolved acoustic streaming

    NARCIS (Netherlands)

    Marmottant, Philippe; Versluis, Michel; Jong, de Nico; Hilgenfeldt, Sascha; Lohse, Detlef


    We report microscopic observations of the primary flow oscillation of an acoustically driven bubble in contact with a wall, captured with the ultra high-speed camera Brandaris 128 (Chin et al. 2003). The driving frequency is up to 200 kHz, and the imaging frequency is up to 25 MHz. The details of th

  8. Lamb Wave-Based Acoustic Radiation Force-Driven Particle Ring Formation Inside a Sessile Droplet. (United States)

    Destgeer, Ghulam; Ha, Byunghang; Park, Jinsoo; Sung, Hyung Jin


    We demonstrate an acoustofluidic device using Lamb waves (LWs) to manipulate polystyrene (PS) microparticles suspended in a sessile droplet of water. The LW-based acoustofluidic platform used in this study is advantageous in that the device is actuated over a range of frequencies without changing the device structure or electrode pattern. In addition, the device is simple to operate and cheap to fabricate. The LWs, produced on a piezoelectric substrate, attenuate inside the fluid and create acoustic streaming flow (ASF) in the form of a poloidal flow with toroidal vortices. The PS particles experience direct acoustic radiation force (ARF) in addition to being influenced by the ASF, which drive the concentration of particles to form a ring. This phenomenon was previously attributed to the ASF alone, but the present experimental results confirm that the ARF plays an important role in forming the particle ring, which would not be possible in the presence of only the ASF. We used a range of actuation frequencies (45-280 MHz), PS particle diameters (1-10 μm), and droplet volumes (5, 7.5, and 10 μL) to experimentally demonstrate this phenomenon.

  9. Nonlinear activity of acoustically driven gas bubble near a rigid boundary

    Energy Technology Data Exchange (ETDEWEB)

    Maksimov, Alexey [Pacific Oceanological Institute, Vladivostok 690041 (Russian Federation)


    The presence of a boundary can produce considerable changes in the oscillation amplitude of the bubble and its scattered echo. The present study fills a gap in the literature, in that it is concerned theoretically with the bubble activity at relatively small distances from the rigid boundary. It was shown that the bi-spherical coordinates provide separation of variables and are more suitable for analysis of the dynamics of these constrained bubbles. Explicit formulas have been derived which describe the dependence of the bubble emission near a rigid wall on its size and the separation distance between the bubble and the boundary. As applications, time reversal technique for gas leakage detection and radiation forces that are induced by an acoustic wave on a constrained bubble were analyzed.

  10. Very-Low-Frequency Subionospheric Remote Sensing of Thunderstorm-driven Acoustic and Gravity Waves in the D-region (United States)

    Marshall, R. A.; Snively, J. B.


    We present observations of thunderstorm-driven perturbations to the D-region ionosphere measured by VLF subionospheric remote sensing (VLF-SRS). VLF-SRS is sensitive to electron density and collision frequency disturbances in a narrow altitude range near 85 km along the great-circle-path (GCP) between a VLF transmitter and a receiver some thousands of km away. These disturbances are measured as amplitude and/or phase perturbations to the continuous VLF transmitter signal. On March 20, 2001, a prominent event was observed by VLF receivers in Colorado monitoring the VLF transmitter in Puerto Rico, exhibiting unusually strong amplitude perturbations of up to 0.6 dB, with periods of 1-3 minutes, but no detectable phase perturbations. As these periods are well below the minimum Brunt-Vaisala period of about 5 minutes, we hypothesize that they may be associated with thunderstorm-generated acoustic waves (AWs). The GCPs from this transmitter to the receivers passed through two thunderstorms at the time of the AW event, one near the southern tip of Florida and the other over the Florida panhandle. The apparent AW event lasted for about one hour and was observed on four near-parallel GCPs separated by a few tens of km at the thunderstorm location. This data shows that VLF-SRS may provide a new, high-time-resolution (better than 1 Hz) monitoring system for acoustic and gravity waves in the upper atmosphere. To investigate the hypothesized AW source for this event, we use a two-step simulation process. A nonlinear, compressible, atmospheric dynamics model is used to simulate acoustic wave propagation from a defined source near the ground to 200 km altitude. Case studies are constructed to investigate different source configurations and perturbations to ionospheric density profiles. The modified electron and neutral density are then input to a finite-difference electromagnetic code that simulates the VLF transmitter signal propagation to the receiver over a distance of ~5000

  11. An IT R&D-programme without new code?! –State driven IT-development in Denmark

    DEFF Research Database (Denmark)

    Koch, Christian; Haugen, Tore


    clients of buildings cooperates with the consortia established in the programme and the assumption is that the construction sector actors will engage in developing a basis for a future legislated digital interaction with the public clients. The funding is in the same spirit limited (a total of 4 millions......The paper evaluates a public R&D programme on IT in Construction. The particular programme theory is presented. We identify the vision, the means and the awaited effects of the programmes and analyse on the background of other public development programs how this one might work. We use innovation...... network theory to establish the point that the program theory and its initial program coalition is weaved into a political process, that makes the development a emergent process of network building. Some of the main elements of the program are: There is no funding for developing new software. Rather...

  12. Modeling of an omni-directional electromagnetic acoustic transducer driven by the Lorentz force mechanism (United States)

    Wang, Shen; Huang, Songling; Zhang, Yu; Zhao, Wei


    The electromagnetic acoustic transducers (EMATs) are gaining much attention in recent years due to their non-contact operation in ultrasonic wave generation and reception in NDT field. Quite often the transduction efficiency of EMATs is low, so efforts are always necessary to gain a better understanding of their complex and multi-physics transduction mechanism. In this work, we focused on modeling of an omni-directional Lorentz force-based EMAT operating on an aluminum disk and containing a rounded meander coil to generate a pure Lamb wave mode. We introduced an approach to solve the underlying eddy current equations in cylindrical coordinates directly, and applied this approach to a multi-conductor electromagnetic model to investigate the skin and proximity effects. These effects existed both for the complete and incomplete equations. Then we built the omni-directional EMAT model composed of three sub-models and two geometries. The two-geometry structure made it possible to reduce the total number of elements. Time varying spatial distribution of the Lorentz force vector was plotted. Propagation velocity of the simulated wave packet was compared with the group velocity of desired S0 mode Lamb waves. Interaction of the waves with a slot defect with a depth of 50% thickness was studied. The response to high current excitation and dynamic magnetic field was also investigated.

  13. Angular Momentum Transport and Variability in Boundary Layers of Accretion Disks Driven by Global Acoustic Modes

    CERN Document Server

    Belyaev, Mikhail A; Stone, James M


    Disk accretion onto a weakly magnetized central object, e.g. a star, is inevitably accompanied by the formation of a boundary layer near the surface, in which matter slows down from the highly supersonic orbital velocity of the disk to the rotational velocity of the star. We perform high resolution 2D hydrodynamical simulations in the equatorial plane of an astrophysical boundary layer with the goal of exploring the dynamics of non-axisymmetric structures that form there. We generically find that the supersonic shear in the boundary layer excites non-axisymmetric quasi-stationary acoustic modes that are trapped between the surface of the star and a Lindblad resonance in the disk. These modes rotate in a prograde fashion, are stable for hundreds of orbital periods, and have a pattern speed that is less than and of order the rotational velocity at the inner edge of the disk. The origin of these intrinsically global modes is intimately related to the operation of a corotation amplifier in the system. Dissipation...

  14. Analysis Grid for Environments Linked to Obesity (ANGELO) framework to develop community-driven health programmes in an Indigenous community in Canada. (United States)

    Willows, Noreen; Dyck Fehderau, David; Raine, Kim D


    Indigenous First Nations people in Canada have high chronic disease morbidity resulting in part from enduring social inequities and colonialism. Obesity prevention strategies developed by and for First Nations people are crucial to improving the health status of this group. The research objective was to develop community-relevant strategies to address childhood obesity in a First Nations community. Strategies were derived from an action-based workshop based on the Analysis Grid for Environments Linked to Obesity (ANGELO) framework. Thirteen community members with wide-ranging community representation took part in the workshop. They combined personal knowledge and experience with community-specific and national research to dissect the broad array of environmental factors that influenced childhood obesity in their community. They then developed community-specific action plans focusing on healthy eating and physical activity for children and their families. Actions included increasing awareness of children's health issues among the local population and community leadership, promoting nutrition and physical activity at school, and improving recreation opportunities. Strengthening children's connection to their culture was considered paramount to improving their well-being; thus, workshop participants developed programmes that included elders as teachers and reinforced families' acquaintance with First Nations foods and activities. The research demonstrated that the ANGELO framework is a participatory way to develop community-driven health programmes. It also demonstrated that First Nations people involved in the creation of solutions to health issues in their communities may focus on decolonising approaches such as strengthening their connection to indigenous culture and traditions. External funds were not available to implement programmes and there was no formal follow-up to determine if community members implemented programmes. Future research needs to examine the

  15. A laboratory acoustic emission experiment and numerical simulation of rock fracture driven by a high-pressure fluid source

    Directory of Open Access Journals (Sweden)

    Xinglin Lei


    Full Text Available In order to improve our understanding of rock fracture and fault instability driven by high-pressure fluid sources, the authors carried out rock fracture tests using granite under a confining pressure of 80 MPa with fluid injection in the laboratory. Furthermore, we tested a number of numerical models using the FLAC3D modeling software to find the best model to represent the experimental results. The high-speed multichannel acoustic emission (AE waveform recording system used in this study made it possible to examine the total fracture process through detailed monitoring of AE hypocenters and seismic velocity. The experimental results show that injecting high-pressure oil into the rock sample can induce AE activity at very low stress levels and can dramatically reduce the strength of the rock. The results of the numerical simulations show that major experimental results, including the strength, the temporal and spatial patterns of the AE events, and the role of the fluid can be represented fairly well by a model involving (1 randomly distributed defect elements to model pre-existing cracks, (2 random modification of rock properties to represent inhomogeneity introduced by different mineral grains, and (3 macroscopic inhomogeneity. Our study, which incorporates laboratory experiments and numerical simulations, indicates that such an approach is helpful in finding a better model not only for simulating experimental results but also for upscaling purposes.

  16. Magneto-acoustic waves driven by self-generated magnetic field: relevance to helical structures in MagLIF experiments (United States)

    Davies, Jonathan; Barnak, Daniel; Betti, Riccardo; Carreon, Adam; Chang, Po-Yu; Fiksel, Gennady


    The observation of coherent helical structures in liner implosions on Z when an axial magnetic field more than 100 times smaller than the azimuthal field is added has yet to be adequately explained. The results have been reproduced in a 3D MHD code by initializing helices on the outer surface, but this produces helices independently of the axial magnetic field. We present the hypothesis that helices are seeded by self-generated magnetic field, which adds a driving term to the dispersion relation for magneto-acoustic waves when there is a temperature gradient perpendicular to the fluid motion. The key feature of this instability is that it is stable when magnetic pressure exceeds a fraction of the thermal pressure, therefore, instability driven by the helical field resulting from the combination of the initial axial field and the growing azimuthal field will stabilize before the net field has a small pitch angle and before the implosion starts, seeding helices on the surface. This work was supported by the Department of Energy National Nuclear Security Administration, Award Number DE-NA0001944, and the Fusion Science Center supported by the Office of Fusion Energy Sciences, Number DE-FG02-04ER54786.

  17. An acoustically-driven biochip - Impact of flow on the cell-association of targeted drug carriers

    CERN Document Server

    Fillafer, Christian; Neumann, Jürgen; Guttenberg, Zeno; Dissauer, Silke; Lichtscheidl, Irene; Wirth, Michael; Gabor, Franz; Schneider, Matthias; 10.1039/B906006E


    The interaction of targeted drug carriers with epithelial and endothelial barriers in vivo is largely determined by the dynamics of the body fluids. To simulate these conditions in binding assays, a fully biocompatible in vitro model was developed which can accurately mimic a wide range of physiological flow conditions on a thumbnail-format cell-chip. This acoustically-driven microfluidic system was used to study the interaction characteristics of protein-coated particles with cells. Poly(D,L-lactide-co-glycolide) (PLGA) microparticles (2.86 {\\pm} 0.95 {\\mu}m) were conjugated with wheat germ agglutinin (WGA-MP, cytoadhesive protein) or bovine serum albumin (BSA-MP, nonspecific protein) and their binding to epithelial cell monolayers was investigated under stationary and flow conditions. While mean numbers of 1500 {\\pm} 307 mm-2 WGA-MP and 94 {\\pm} 64 mm-2 BSA-MP respectively were detected to be cell-bound in the stationary setup, incubation at increasing flow velocities increasingly antagonized the attachment...

  18. Ion temperature anisotropy effects on threshold conditions of a shear-modified current driven electrostatic ion-acoustic instability in the topside auroral ionosphere


    Perron, P. J. G.; J.-M. A. Noël; Kabin, K.; St-Maurice, J.-P.


    Temperature anisotropies may be encountered in space plasmas when there is a preferred direction, for instance, a strong magnetic or electric field. In this paper, we study how ion temperature anisotropy can affect the threshold conditions of a shear-modified current driven electrostatic ion-acoustic (CDEIA) instability. In particular, this communication focuses on instabilities in the context of topside auroral F-region situations and in the limit where finite Larmor radius...

  19. Digital stroboscopic holographic interferometry for power flow measurements in acoustically driven membranes (United States)

    Keustermans, William; Pires, Felipe; De Greef, Daniël; Vanlanduit, Steve J. A.; Dirckx, Joris J. J.


    Despite the importance of the eardrum and the ossicles in the hearing chain, it remains an open question how acoustical energy is transmitted between them. Identifying the transmission path at different frequencies could lead to valuable information for the domain of middle ear surgery. In this work a setup for stroboscopic holography is combined with an algorithm for power flow calculations. With our method we were able to accurately locate the power sources and sinks in a membrane. The setup enabled us to make amplitude maps of the out-of-plane displacement of a vibrating rubber membrane at subsequent instances of time within the vibration period. From these, the amplitude maps of the moments of force and velocities are calculated. The magnitude and phase maps are extracted from this amplitude data, and form the input for the power flow calculations. We present the algorithm used for the measurements and for the power flow calculations. Finite element models of a circular plate with a local energy source and sink allowed us to test and optimize this algorithm in a controlled way and without the present of noise, but will not be discussed below. At the setup an earphone was connected with a thin tube which was placed very close to the membrane so that sound impinges locally on the membrane, hereby acting as a local energy source. The energy sink was a little piece of foam carefully placed against the membrane. The laser pulses are fired at selected instants within the vibration period using a 30 mW HeNe continuous wave laser (red light, 632.8 nm) in combination with an acousto-optic modulator. A function generator controls the phase of these illumination pulses and the holograms are recorded using a CCD camera. We present the magnitude and phase maps as well as the power flow measurements on the rubber membrane. Calculation of the divergence of this power flow map provides a simple and fast way of identifying and locating an energy source or sink. In conclusion

  20. Dependency of colorectal cancer on a TGF-beta-driven programme in stromal cells for metastasis initiation (United States)

    Calon, Alexandre; Espinet, Elisa; Palomo-Ponce, Sergio; Tauriello, Daniele V. F.; Iglesias, Mar; Céspedes, María Virtudes; Sevillano, Marta; Nadal, Cristina; Jung, Peter; Zhang, Xiang H.-F.; Byrom, Daniel; Riera, Antoni; Rossell, David; Mangues, Ramón; Massague, Joan; Sancho, Elena; Batlle, Eduard


    SUMMARY A large proportion of colorectal cancers (CRCs) display mutational inactivation of the TGF-beta pathway yet paradoxically, they are characterized by elevated TGF-beta production. Here, we unveil a prometastatic programme induced by TGF-beta in the microenvironment that associates with a high-risk of CRC relapse upon treatment. The activity of TGF-beta on stromal cells increases the efficiency of organ colonization by CRC cells whereas mice treated with a pharmacological inhibitor of TGFBR1 are resilient to metastasis formation. Secretion of IL11 by TGF-beta-stimulated cancer-associated fibroblasts (CAFs) triggers GP130/STAT3 signalling in tumour cells. This crosstalk confers a survival advantage to metastatic cells. The dependency on the TGF-beta stromal programme for metastasis initiation could be exploited to improve the diagnosis and treatment of CRC. PMID:23153532

  1. Ion temperature anisotropy effects on threshold conditions of a shear-modified current driven electrostatic ion-acoustic instability in the topside auroral ionosphere

    Directory of Open Access Journals (Sweden)

    P. J. G. Perron


    Full Text Available Temperature anisotropies may be encountered in space plasmas when there is a preferred direction, for instance, a strong magnetic or electric field. In this paper, we study how ion temperature anisotropy can affect the threshold conditions of a shear-modified current driven electrostatic ion-acoustic (CDEIA instability. In particular, this communication focuses on instabilities in the context of topside auroral F-region situations and in the limit where finite Larmor radius corrections are small. We derived a new fluid-like expression for the critical drift which depends explicitly on ion anisotropy. More importantly, for ion to electron temperature ratios typical of F-region, solutions of the kinetic dispersion relation show that ion temperature anisotropy may significantly lower the drift threshold required for instability. In some cases, a perpendicular to parallel ion temperature ratio of 2 and may reduce the relative drift required for the onset of instability by a factor of approximately 30, assuming the ion-acoustic speed of the medium remains constant. Therefore, the ion temperature anisotropy should be considered in future studies of ion-acoustic waves and instabilities in the high-latitude ionospheric F-region.

  2. From Architectural Acoustics to Acoustical Architecture Using Computer Simulation

    DEFF Research Database (Denmark)

    Schmidt, Anne Marie Due; Kirkegaard, Poul Henning


    Architectural acoustics design has in the past been based on simple design rules. However, with a growing complexity in architectural acoustics and the emergence of room acoustic simulation programmes with considerable potential, it is now possible to subjectively analyse and evaluate acoustic...... properties prior to the actual construction of a building. With the right tools applied, acoustic design can become an integral part of the architectural design process. The aim of this paper is to investigate the field of application that an acoustic simulation programme can have during an architectural...... acoustic design process and to set up a strategy to develop future programmes. The emphasis is put on the first three out of four phases in the working process of the architect and a case study is carried out in which each phase is represented by typical results ? as exemplified with reference...

  3. A surface acoustic wave-driven micropump for particle uptake investigation under physiological flow conditions in very small volumes

    Directory of Open Access Journals (Sweden)

    Florian G. Strobl


    Full Text Available Static conditions represent an important shortcoming of many in vitro experiments on the cellular uptake of nanoparticles. Here, we present a versatile microfluidic device based on acoustic streaming induced by surface acoustic waves (SAWs. The device offers a convenient method for introducing fluid motion in standard cell culture chambers and for mimicking capillary blood flow. We show that shear rates over the whole physiological range in sample volumes as small as 200 μL can be achieved. A precise characterization method for the induced flow profile is presented and the influence of flow on the uptake of Pt-decorated CeO2 particles by endothelial cells (HMEC-1 is demonstrated. Under physiological flow conditions the particle uptake rates for this system are significantly lower than at low shear conditions. This underlines the vital importance of the fluidic environment for cellular uptake mechanisms.

  4. Can diving-induced tissue nitrogen supersaturation increase the chance of acoustically driven bubble growth in marine mammals? (United States)

    Houser, D S; Howard, R; Ridgway, S


    The potential for acoustically mediated causes of stranding in cetaceans (whales and dolphins) is of increasing concern given recent stranding events associated with anthropogenic acoustic activity. We examine a potentially debilitating non-auditory mechanism called rectified diffusion. Rectified diffusion causes gas bubble growth, which in an insonified animal may produce emboli, tissue separation and high, localized pressure in nervous tissue. Using the results of a dolphin dive study and a model of rectified diffusion for low-frequency exposure, we demonstrate that the diving behavior of cetaceans prior to an intense acoustic exposure may increase the chance of rectified diffusion. Specifically, deep diving and slow ascent/descent speed contributes to increased gas-tissue saturation, a condition that amplifies the likelihood of rectified diffusion. The depth of lung collapse limits nitrogen uptake per dive and the surface interval duration influences the amount of nitrogen washout from tissues between dives. Model results suggest that low-frequency rectified diffusion models need to be advanced, that the diving behavior of marine mammals of concern needs to be investigated to identify at-risk animals, and that more intensive studies of gas dynamics within diving marine mammals should be undertaken.

  5. Frequency-shift vibro-acoustic modulation driven by low-frequency broadband excitations in a bistable cantilever oscillator (United States)

    He, Qingbo; Xu, Yanyan; Lu, Siliang; Shao, Yong


    This paper reports a frequency-shift vibro-acoustic modulation (VAM) effect in a bistable microcracked cantilever oscillator. Low-frequency broadband excitations induced a VAM effect with a shifted modulation frequency through involving a microcracked metal beam in a bistable oscillator model. We used nonlinear dynamics equations and principles to describe the mechanism of a bistable oscillator whose natural frequency varied as the oscillation amplitude increased. We demonstrated this frequency-shift VAM effect using a prototype bistable oscillator model designed to efficiently detect microcracks in solid materials via the VAM effect using ambient vibration excitations.

  6. Current-driven ion-acoustic and potential-relaxation instabilities excited in plasma plume during electron beam welding (United States)

    Trushnikov, D. N.; Mladenov, G. M.; Belenkiy, V. Ya.; Koleva, E. G.; Varushkin, S. V.


    Many papers have sought correlations between the parameters of secondary particles generated above the beam/work piece interaction zone, dynamics of processes in the keyhole, and technological processes. Low- and high-frequency oscillations of the current, collected by plasma have been observed above the welding zone during electron beam welding. Low-frequency oscillations of secondary signals are related to capillary instabilities of the keyhole, however; the physical mechanisms responsible for the high-frequency oscillations (>10 kHz) of the collected current are not fully understood. This paper shows that peak frequencies in the spectra of the collected high-frequency signal are dependent on the reciprocal distance between the welding zone and collector electrode. From the relationship between current harmonics frequency and distance of the collector/welding zone, it can be estimated that the draft velocity of electrons or phase velocity of excited waves is about 1600 m/s. The dispersion relation with the properties of ion-acoustic waves is related to electron temperature 10 000 K, ion temperature 2 400 K and plasma density 1016 m-3, which is analogues to the parameters of potential-relaxation instabilities, observed in similar conditions. The estimated critical density of the transported current for creating the anomalous resistance state of plasma is of the order of 3 A.m-2, i.e. 8 mA for a 3-10 cm2 collector electrode. Thus, it is assumed that the observed high-frequency oscillations of the current collected by the positive collector electrode are caused by relaxation processes in the plasma plume above the welding zone, and not a direct demonstration of oscillations in the keyhole.

  7. Acoustic ground impedance meter (United States)

    Zuckerwar, A. J. (Inventor)


    A method and apparatus are presented for measuring the acoustic impedance of a surface in which the surface is used to enclose one end of the chamber of a Helmholz resonator. Acoustic waves are generated in the neck of the resonator by a piston driven by a variable speed motor through a cam assembly. The acoustic waves are measured in the chamber and the frequency of the generated acoustic waves is measured by an optical device. These measurements are used to compute the compliance and conductance of the chamber and surface combined. The same procedure is followed with a calibration plate having infinite acoustic impedance enclosing the chamber of the resonator to compute the compliance and conductance of the chamber alone. Then by subtracting, the compliance and conductance for the surface is obtained.

  8. On architectural acoustic design using computer simulation

    DEFF Research Database (Denmark)

    Schmidt, Anne Marie Due; Kirkegaard, Poul Henning


    acoustic design process. The emphasis is put on the first three out of five phases in the working process of the architect and a case study is carried out in which each phase is represented by typical results ? as exemplified with reference to the design of Bagsværd Church by Jørn Utzon. The paper......Architectural acoustics design has in the past been based on simple design rules. However, with a growing complexity in architectural acoustics and the emergence of room acoustic simulation programmes with considerable potential, it is now possible to subjectively analyse and evaluate acoustic...... properties prior to the actual construction of a building. With the right tools applied, acoustic design can become an integral part of the architectural design process. The aim of this paper is to investigate the field of application that an acoustic simulation programme can have during an architectural...

  9. Acoustic cryocooler (United States)

    Swift, Gregory W.; Martin, Richard A.; Radenbaugh, Ray


    An acoustic cryocooler with no moving parts is formed from a thermoacoustic driver (TAD) driving a pulse tube refrigerator (PTR) through a standing wave tube. Thermoacoustic elements in the TAD are spaced apart a distance effective to accommodate the increased thermal penetration length arising from the relatively low TAD operating frequency in the range of 15-60 Hz. At these low operating frequencies, a long tube is required to support the standing wave. The tube may be coiled to reduce the overall length of the cryocooler. One or two PTR's are located on the standing wave tube adjacent antinodes in the standing wave to be driven by the standing wave pressure oscillations. It is predicted that a heat input of 1000 W at 1000 K will maintian a cooling load of 5 W at 80 K.

  10. Observation of acoustic-phonon-like mode driven by magnetic imbalance between neighboring Fe atoms in Fe1+yTe (y < 0 . 12) (United States)

    Fobes, David; Zaliznyak, Igor; Xu, Zhijun; Gu, Genda; Tranquada, John M.; He, Xu-Gang; Ku, Wei; Garlea, Ovidiu


    We have studied the evolution with temperature of the low-energy inelastic spectra of Fe1+yTe (y < 0 . 12), a parent compound of the iron-chalcogenide superconductor family, revealing an acoustic mode at an unexpected position. Recently, we found evidence for the formation of a bond-order wave leading to ferro-orbital order in the monoclinic phase, in part due to the observation of an elastic structural peak at (100) in the low-temperature monoclinic phase [D. Fobes, et al., arXiv:1307.7162]. In the inelastic spectra we observe a sharp acoustic-phonon-like mode dispersing out of the (100) position in the monoclinic phase. Surprisingly, the mode survives in the tetragonal phase, despite the absence of a Bragg peak at (100); such a peak is forbidden by symmetry. LDA calculations suggest this mode could involve significant magnetic scattering. By assuming in-phase virtual displacement of the Fe atoms from their equilibrium position in a frozen phonon calculation, we have found a small but significant imbalance in the magnetic moments between the two Fe atoms within the unit cell, suggesting magnetic contribution to the mode. Work at BNL supported by Office of Basic Energy Sciences, US DOE, under Contract No. DE-AC02-98CH10886. Research conducted at ORNL Spallation Neutron Source was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, US DOE.

  11. Communication Acoustics

    DEFF Research Database (Denmark)

    Blauert, Jens

    Communication Acoustics deals with the fundamentals of those areas of acoustics which are related to modern communication technologies. Due to the advent of digital signal processing and recording in acoustics, these areas have enjoyed an enormous upswing during the last 4 decades. The book...... the book a source of valuable information for those who want to improve or refresh their knowledge in the field of communication acoustics - and to work their way deeper into it. Due to its interdisciplinary character Communication Acoustics is bound to attract readers from many different areas, such as......: acoustics, cognitive science, speech science, and communication technology....

  12. Tools to evaluate seafloor integrity: comparison of multi-device acoustic seafloor classifications for benthic macrofauna-driven patterns in the German Bight, southern North Sea (United States)

    Holler, Peter; Markert, Edith; Bartholomä, Alexander; Capperucci, Ruggero; Hass, H. Christian; Kröncke, Ingrid; Mielck, Finn; Reimers, H. Christian


    To determine the spatial resolution of sediment properties and benthic macrofauna communities in acoustic backscatter, the suitability of four acoustic seafloor classification devices (single-beam echosounder with RoxAnn and QTC 5.5 seafloor classification system, sidescan sonar with QTC Swathview seafloor classification, and multi-beam echosounder with QTC Swathview seafloor classification) was compared in a study area of approx. 6 km2 northwest of the island of Helgoland in the German Bight, southern North Sea. This was based on a simple similarity index between simultaneous sidescan sonar, single-beam echosounder and multi-beam echosounder profiling spanning the period 2011-2014. The results show a high similarity between seafloor classifications based on sidescan sonar and RoxAnn single-beam systems, in turn associated with a lower similarity for the multi-beam echosounder system. Analyses of surface sediment samples at 39 locations along four transects (0.1 m2 Van Veen grab) revealed the presence of sandy mud (southern and western parts), coarse sand, gravel and cobbles. Rock outcrops were identified in the north-eastern and eastern parts. A typical Nucula nitidosa-Abra alba community was found in sandy muds to muddy sands in the northern part, whereas the southern part is characterised by widespread occurrence of the ophiuroid brittle star Amphiura filiformis. A transitional N. nitidosa-A. filiformis community was detected in the central part. Moreover, the southern part is characterised by a high abundance of A. filiformis and its commensal bivalve Kurtiella bidentata. The high number of A. filiformis feeding arms (up to ca. 6,800 per m2) can largely explain the gentle change of backscatter intensity along the tracks, because sediment composition and/or seafloor structures showed no significant variability.

  13. Acoustic telemetry (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — To determine movements of green turtles in the nearshore foraging areas, we deployed acoustic tags and determined their movements through active and passive acoustic...

  14. Technology Programme

    Energy Technology Data Exchange (ETDEWEB)

    Batistoni, Paola; De Marco, Francesco; Pieroni, Leonardo (ed.)


    The technology activities carried out by the Euratom-ENEA Association in the framework of the European Fusion Development Agreement concern the Next Step (International Thermonuclear Experimental Reactor - ITER), the Long-Term Programme (breeder blanket, materials, International Fusion Materials Irradiation Facility - IFMIF), Power Plant Conceptual Studies and Socio-Economic Studies. The Underlying Technology Programme was set up to complement the fusion activities as well to develop technologies with a wider range of interest. The Technology Programme mainly involves staff from the Frascati laboratories of the Fusion Technical and Scientific Unit and from the Brasimone laboratories of the Advanced Physics Technologies Unit. Other ENEA units also provide valuable contributions to the programme. ENEA is heavily engaged in component development/testing and in design and safety activities for the European Fusion Technology Programme. Although the work documented in the following covers a large range of topics that differ considerably because they concern the development of extremely complex systems, the high level of integration and coordination ensures the capability to cover the fusion system as a whole. In 2004 the most significant testing activities concerned the ITER primary beryllium-coated first wall. In the field of high-heat-flux components, an important achievement was the qualification of the process for depositing a copper liner on carbon fibre composite (CFC) hollow tiles. This new process, pre-brazed casting (PBC), allows the hot radial pressing (HRP) joining procedure to be used also for CFC-based armour monoblock divertor components. The PBC and HRP processes are candidates for the construction of the ITER divertor. In the materials field an important milestone was the commissioning of a new facility for chemical vapour infiltration/deposition, used for optimising silicon carbide composite (SiCf/SiC) components. Eight patents were deposited during 2004

  15. The EU fusion programme and roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Pero, H., E-mail: [European Commission, DG-RTD, CDMA 05/146, B-1049 Brussels (Belgium); Paidassi, S. [European Commission, DG-RTD, CDMA 05/146, B-1049 Brussels (Belgium)


    Highlights: ► The EU fusion programme has to evolve from today's research to a strong goal-oriented programme driven by an ambitious roadmap. ► The programme shall focus on ITER and reactor-relevant technologies development. ► A new structure based on joint programming will be developed to implement the programme during Horizon 2020. -- Abstract: To meet ITER and fusion energy challenges, a gradual transition of the EU fusion programme priorities from today's fusion research to a strongly goal-oriented programme with clear milestones is required. This transition and the programme priorities should be driven by an ambitious, yet realistic roadmap to be agreed by EU fusion stakeholders. The programme must primarily focus on: ensuring the success of ITER; and research and development of reactor-relevant technologies. Industry must be involved early in the implementation and international collaboration should be conducted as part of a strategic approach. Joint programming should be a cornerstone of the EU fusion programme in Horizon 2020. Options for the new structure and current actions required to implement the roadmap during Horizon 2020 will be presented.


    CERN Multimedia

    Fedosseev, V; Lynch, K M; Grob, L K; Herfurth, F; Scheidenberger, C; Geppert, C; Gorges, C; Ratajczyk, T; Vogel, S; Munch, M K; Nieminen, P; Pakarinen, J J A; Lecesne, N; Bouzomita, H; Grinyer, J; Marques moreno, F M; Parlog, M; Pedroza, J; Ghetta, V; Lozeva, R; Guillemaud mueller, D S; Cottereau, E; Cheikh mhamed, M; Tusseau nenez, S; Tungate, G; Walker, P M; Smith, A G; Fitzpatrick, C; Dominik, W M; Karny, M; Ciemny, A A; Nyman, G H; Thies, R M A; Lindberg, S K G; Langouche, G F; Delaure, B J P; Mayet, P; Ory, G T; Kesteloot, N J K; Papuga, J; Dehairs, M H R; Callens, M; Boudreau, M; Domnanich, K A; Richter, D; Lutter, R J; Wiehr, S; Nacher gonzalez, E; Jungclaus, A; Ribeiro jimenez, G; Marroquin alonso, I; Cal gonzalez, J; Paziy, V; Salsac, M; Murphy, C; Podolyak, Z F; Bajoga, A D; Butler, P; Pritchard, A; Steer, A N; Fox, S P; Wadsworth, B A; Truesdale, V L; Al monthery, M; Guttormsen, M S; Ingeberg, V W; Badea, M N; Calinescu, S; Cederkall, J A; Zemlyanoy, S; Donets, E D; Golovkov, M; Wu, C; Harrichunder, S; Ncube, M; Gerten, R F; Lehnert, J; Gladnishki, K A; Rainovski, G I; Pospisil, S; Datta pramanik, U; Benzoni, G; Fedorov, D; Molkanov, P; Pfeiffer, B; Griesel, T; Wehner, L W; Mikkelsen, M; Recchia, F; Smith, J F; Kelly, C M; De melo bandeira tavares, P M; Vieira, J M; Martins da silva, M A; Lima lopes, A M; Mader, J; Kessler, P; Laurent, B G; Schweikhard, L C; Marx, G H; Kulczycka, E; Komorowska, M; Da silva, M F; Goncalves marques, C P; Baptista peres, M A; Welander, J E; Leimbach, D; Coeck, S; Ryssens, W A M; Knoops, G; Vanbuel, J; Reiter, P; Miller, C; Martin sanchez-cano, D; Wiens, A; Blazhev, A A; Braun, N; Cappellazzo, M V; Birkenbach, B; Gerst, R; Dannhoff, M F; Sithole, M J; Bilgier, B; Nardelli, S; Vetter, U; Araujo mendes, C M; Agramunt ros, J; Valencia marin, E; Pantea, E; Hessberger, F P; Leduc, A J; Mitsuoka, S; Carbonari, A W; Buchegger, F J; Garzon camacho, A; Stachura, M K; Stora, T; Marsh, B A; Thiboud, J A; Antalic, S; Stahl, C; Bauer, C; Thurauf, M; Maass, B; Sturm, S; Boehm, C; Ways, M; Heylen, H; Riisager, K; Ruotsalainen, P A; Bastin, B; Duval, F T; Penessot, G; Flechard, X D; Desrues, P; Giovinazzo, J; Blank, B A; Kurtukian nieto, T; Ascher, P E L; Roccia, S; Matea, I; Croizet, H A G; Bonnin, C M; Morfouace, P; Smith, A J; Guin, R; Banerjee, D; Gunnlaugsson, H P; Ohtsubo, T; Zhukov, M V; Tengborn, E A; Dessagne, P; Juscamaita vivanco, Y; De rydt, M A E; Vermaelen, P; Monten, R; Yang, X; De coster, A; Kruecken, R; Nowak, A K; Cano ott, D; Murphy, A S J; Shand, C M; Regan, P H; Jones, G D; Herzberg, R; Ikin, P; Napoli, D R; Scarel, G; Larsen, A; Tornyi, T G; Pascu, S G; Stroe, L; Toma, S; Jansson, K; Dronjak fahlander, M; Krupko, S; Hurst, A M; Veskovic, M; Nikolov, J; Sibanda, W N; Rocchini, M; Klimo, J; Deicher, M; Wichert, T; Wolf, E; Kronenberg, J; Helmke, A; Meliani, Z; Ivanov, V S; Kuti, I; Halasz, Z; Henry, M O; Bras de sequeira amaral, V; Espirito santo, F; Da silva, D J; Carvalho teixeira, R C; Rosendahl, S; Speidel, K; Agarwal, I; Faul, T; Kownacki, J M; Martins correia, J G; Lorenz, K; Costa miranda, S M; Granadeiro costa, A R; Da costa pereira, L M; Keupers, M; Stukken, R; Wursten, E J; Kotthaus, T; Pfeiffer, M; Gironi, L; Cakirli, R B; Jensen, A; Romstedt, F; Constantino silva furtado, I; Heredia cardona, J A; Jordan martin, M D; Montaner piza, A; Zacate, M O; Plewinski, F; Mesli, A; Pichard, A; Hergemoller, F; Fallis starhunter, J P; Voulot, D; Mrazek, J; Ugryumov, V; Savreux, R P; Kojouharov, I M; Stegmann, R; Kern, R O; Fitting, J; Lauer, M; Kirsebom, O S; Jensen, K L; Jokinen, A; Rahkila, P J; Hager, U D K; Konki, J P; Dubois, M; Orr, N A; Fabian, X; Huikari, J E; Goigoux, T; Magron, C; Zakari, A A; Maietta, M; Bachelet, C E M; Roussiere, B; Li, R; Foster, R M; Mertzimekis, T; Gislason, H P; Shayestehaminzadeh, S; Qi, B; Mukai, M; Watanabe, Y; Willmann, L; Kurcewicz, W; Wimmer, K; Meisel, Z P; Dorvaux, O; Nowacki, F; Lievens, P; Neyens, G; Darby, I G; Descamps, B O; Ceruti, S; Bunka, M; Vermeulen, C; Umbricht, C A; De boer, J; Podadera aliseda, I; Alcorta moreno, M; Pesudo fortes, V; Zielinska, M; Korten, W; Wang, C H; Lotay, G J; Mason, P; Rice, S J; Willenegger, L M; Judson, D S; Revill, J P; Andreev, A; Yavuzkanat, N; Hass, M; Kumar, V; Crespo campo, L; Zamfir, N - V; Deleanu, D; Jeppesen, H B; Pain, S D; Stracener, D W; Matousek, V; Venhart, M; Birova, M; Li, X; Stuchbery, A E; Lellep, G M; Chakraborty, S; Leoni, S; Chupp, T; Yilmaz, C; Severin, G; Garcia ramos, J E; Hadinia, B; Mc glynn, E; Monteiro de sena silvares de carvalho, I; Friedag, P; Koos, V; Meot, V H; Pauwels, D B; Jancso, A; Srebrny, J; Alves, E J; David bosne, E; Dexters, W M M; Velten, P; Kalkuehler, M; Albers, M; Bharuth-ram, K; Akkus, B; Hemmingsen, L B S; Pedersen, J T; Dos santos redondo, L M; Rubio barroso, B; Algora, A; Kozlov, V; Mokhles gerami, A; Bernardo da silva, E; Unzueta solozabal, I; Schell, J; Szybowicz, M; Lassen, J; Johnston, K; Miyazaki, A; Macko, M; Coquard, L; Bloch, T P; Bonig, E S; Ignatov, A; Paschalis, S; Fernandez martinez, G; Schilling, M; Habermann, T; Von hahn, R; Minaya ramirez, E E; Manea, V; De roubin, A A J; Karthein, J; Moore, I D; Wang, Y; Saastamoinen, A J; Grahn, T; Herzan, A; Stolze, S M; Clement, E; Dijon, A; Shornikov, A; Lienard, E; Gibelin, J D; Pain, C; Canchel, G; Simpson, G S; Latrasse, L P; Huang, W; Forest, D H; Billowes, J; Flanagan, K; Strashnov, I; Binnersley, C L; Simpson, J; Morrall, P S; Grant, A F; Charisopoulos, S; Lagogiannis, A; Bhattacharya, C; Olafsson, S; Tornqvist, H T; Heinz, A M; White iv, E R; Vermote, S L; Courtin, S; Marechal, F; Randisi, G; Rajabali, M M; Lannoo, B J M; Frederickx, R; De coster, T J C; Roovers, N; De lemos lima, T A; Haller, S; Rizzi, M; Reichert, S B; Bonn, J; Thirolf, P G; Garcia rios, A R; Gugliermina, V M; Cubero campos, M A; Sanchez tembleque, V; Benito garcia, J; Senoville, M; Mountford, D J; Gelletly, W; Alharbi, T S T; Wilson, E; Rigby, S V; Andreoiu, C; Paul, E S; O'neill, G G; Harkness, L J; Wraith, C; Van esbroeck, K; Wadsworth, R; Cubiss, J G; Doherty, D T; Harding, R D; Vaintraub, S; Mandal, S K; Hadynska-klek, K; Scarpa, D; Hoff, P; Syed naeemul, H; Borcea, R; Balabanski, D L; Marginean, R; Rotaru, F; Rudolph, D; Fahlander, C H; Chudoba, V; Naidoo, D; Veselsky, M; Kliman, J; Raisanen, J A; Dietrich, M; Maung maung than, M M T; Reed, M W; Danchev, M T; Ray, J; Roy, M; Hammen, M; Capponi, L; Veghne csatlos, M M; Fryar, J; Mirzadeh vaghefi, S P; Trindade pereira, A M; Bakenecker, A; Tramm, C; Germic, V; Morel, P A; Kowalczyk, M; Matejska-minda, M; Ringvall moberg, A; Kana, T; Vermeeren, B R M; Dockx, K; Mantovan, R; Fransen, C H; Radeck, F; Schneiders, D W; Steinbach, T; Vibenholt, J E; Magnussen, M J; Stevnhoved, H M; Comas lijachev, V; Dasenbrock-gammon, N M; Perkowski, J; Matveev, Y; Wegner, M; Garcia borge, M J; Molholt, T E; Srnka, D; Dlouhy, Z; Beck, D; Homm, I; Eliseev, S; Blaum, K; Probst, M B; Kaiser, C J; Martin, J A; Refsgaard, J; Papadakis, F; Peura, P J; Greenlees, P T; Auranen, K; Delahaye, P; Traykov, E K; Perez loureiro, D; Mery, A A; Couratin, C; Tsekhanovich, I; Lunney, D; Gaulard, C V; Althubiti, N A S; Mottram, A D; Das, S K; Van de walle, J; Mazzocchi, C; Jonson, B N G; Woehr, A; Lesher, S R; Zuber, K T; Koudriavtsev, I; De witte, H J; Van den bergh, P A M; Raabe, R; Depuydt, M J F; Radulov, D P; Elseviers, J; Reynders, K L T; Sels, S M C; Verlinde, M; Delombaerde, L; De maesschalck, D; Dunlop, R A; Tarasava, K; Gernhaeuser, R A; Weinzierl, W; Berger, C; Wendt, K; Achtzehn, T; Gottwald, T; Schug, M; Rossel, R E; Dominguez reyes, R R; Briz monago, J A; Koester, U H; Bunce, M R; Bowry, M D; Nakhostin, M; Shearman, R; Cresswell, J R; Joss, D T; Gredley, A; Groombridge, D; Laird, A M; Aslanoglou, X; Siem, S; Weterings, J A; Renstrom, T; Szpak, B T; Luczkowski, M J; Ghita, D; Bezbakh, A; Bollmann, J; Bhattacharya, P; Roy, S; Rahaman, M A; Wlodarski, T; Carvalho soares, J; Barzakh, A; Werner, V R; Schertz, F; Froemmgen, N E; Liberati, V; Foy, B E; De pinho oliveira, G N; Weinheimer, C P; Zboril, M; Figuera, P; Simon, R E; Popescu, L A; Czosnyka, T; Miranda jana, P A; Buescher, J S L; Plociennik, W A; Ruchowska, E E; Chiara, C J; Eberth, J H; Thomas, T; Thole, P; Queiser, M T; Lo bianco, G; D'amico, F; Muller, S; Sanchez alarcon, R M; Tain enriquez, J L; Orrigo, S E A; Orlandi, R; Plazaola muguruza, F C; Pallada, S; Lepareur, N G; Wildner, E; Kowalska, M; Malbrunot, S; Slezak, M; Roeckl, E; Schrieder, G H; Ilieva, S K; Koenig, K L; Amoretti, M A; Lommen, J M; Fynbo, H O U; Weyer, G O P; Koldste, G T; Madsboll, K; Jensen, J H; Nieminen, A M; Reponen, M; Villari, A; Thomas, J; Saint-laurent, M; Sorlin, O H; Carniol, B; Pereira lopez, J; Grevy, S; Plaisir, C; Marie-jeanne, M J; Georgiev, G P; Etile, A M; Le blanc, F M; Verney, D; Stefan, G I; Assie, M; Suzuki, D; Guillot, J; Vazquez rodriguez, L; Campbell, P; Deacon, A N; Ware, T; Flueras, A; Xie, L; Banerjee, K; Piersa, M; Johansson, H T; Schwarz, S; Welker, A; Krauth, M R; Perrot, F; Aumont, J; Sferrazza, M; Van duppen, P L E; Versyck, S; Dehaes, J; Bree, N C F; Neyskens, P; Martinez palenzuela, Y; De groote, R P; Carlier, L M F; De schepper, S; Dewolf, K W A; Kabir, L R; Garcia ruiz, R F; Khodery ahmad, M A; Zadvornaya, A; Xu, Z; Smolders, P; Krastev, P; Rapisarda, E; Reber, J A; Mattolat, C F; Raeder, S; Habs, D; Martinez perez, T; Fraile prieto, L M; Vidal, M; Perez liva, M; Calvo portela, P; Ulla pedrera, F J; Wood, R T; Lalkovski, S; Page, R; Petri, M; Barton, C J; Nichols, A J; Vermeulen, M J; Bloor, D M; Henderson, J; Wilson, G L; De angelis, G; Buerger, A; Klintefjord, M L; Fornal, B A; Marginean, R; Sava, T; Suvaila, R; Lica, R; Costache, C; Mihai, R; Ionescu, A; Baeck, T M; Masenda, H; Sedlak, M; Koskelo, O K; Kyaw myat, K M; Ganguly, B; Goncalves marques, J; Cardoso, S; Seliverstov, M; Niessen, B D; Gutt, L E; Chapman, R; Spagnoletti, P N; Lopes, C; De oliveira amorim, C; Batista lopes, C M; Araujo, J; Schielke, S J; Daugas, J R; Gaudefroy, L; Chevrier, R; Szunyogh, D M; Napiorkowski, P J; Wrzosek-lipska, K; Wahl, U; Catarino, N; Pereira carvalho alves de sequeira, M; Decoster, S J; Porobic, T; Babo, M; Walters, W; Hess, H E; Holler, A; Bettermann, L; Geibel, K; Taprogge, J; Lewandowski, L T N; Manchado de sola, F; Das gupta, S; Thulstrup, P W; Heinz, U; Nogwanya, T; Neidherr, D M; Domingo pardo, C; Morales lopez, A I; Gumenyuk, O; Peaker, A R; Wakabayashi, Y; Abrahams, K J; Mach, H A; Souza ribeiro junior, I; He, J; Giles, T J; Dorsival, A; Kalaninova, Z; Venos, D; Kraemer, J; Saha, S; Neugart, R; Eronen, T O; Kreim, K D; Heck, M K; Goncharov, M; Julin, R J; Jakobsson, E H U; Eleon, C; Achouri, N L; Grinyer, G F; Fontbonne, C M; Alfaurt, P; Kusoglu, A; Wilkins, S G; Brown, A R; Imai, N; Pomorski, M J; Janiak, L; Nilsson, T; Stroke, H H; Stanja, J; Dangelser, E; Heenen, P; Mallion, S N; Diriken, J V J; Ghys, L H L; Khamehchi, M A; Van beveren, C; Gins, W A M; Bouma, J T; Koszorus, A; Mcnulty, J F; Ohlert, C M; Schwerdtfeger, W; Tengblad, O; Becerril reyes, A D; Perea martinez, A; Martinez perez, M C; Margerin, V; Rudigier, M; Alexander, T D; Patel, Z V; Hammond, N; Wearing, F; Patel, A; Jenkins, D G; Debernardi, A; Giacoppo, F; Tveten, G M; Malatji, K L; Krolas, W A; Stanoiu, M A; Rickert, E U; Ter-akopian, G; Cline, D; Riihimaeki, I A; Simon, K D; Wagner, F E; Turker, M; Neef, M H; Jakubek, J; Vagena, E; Bottoni, S; Nishimura, K; Correia, J; Rodrigues valdrez, C J; Ostrowski, A N; Hallmann, O; Scheck, M; Wady, P T; Lane, J; Krasznahorkay, A J; Kunne sohler, D; Meaney, A J; Baptista barbosa, M; Hochschulz, F; Roig, O; Houngbo, D; Behan, C C; Kargoll, S; Kemnitz, S; Redondo cubero, A; Dirkx, D; Stegemann, S T; Tallarida, G; Kaczarowski, R; Finke, F; Linnemann, A; Altenkirch, R; Saed-samii, N; Ansari, S H; Dlamini, W B; Adoons, V N; Ronning, C R; Wiedeking, M; Guadilla gomez, V; Herlert, A J; Mehl, C V; Judge, S M; Catherall, R; Lettry, J; Wenander, F J C; Zakoucky, D; Catchen, G L; Noertershaeuser, W; Kroell, T; Leske, J; Shubina, D; Murray, I M; Pancin, J; Delaunay, F; Poincheval, J J L; Audirac, L L; Gerbaux, M T; Aouadi, M; Sole, P G P; Fallot, M P; Onillon, A; Duchemin, C; Formento cavaier, R; Audi, G; Boukhari, A; Lau, C; Martin, J A; Barre, N H; Berry, T A; Procter, T J; Farooq-smith, G J; Bladen, L K; Axiotis, M; Muto, S; Jeong, S C; Hirayama, Y; Korgul, A B; Minamisono, K; Bingham, C R; Aprahamian, A; Bucher, B M; Huyse, M L; Himpe, P; Ferrer garcia, R; Sambi, S; Budincevic, I; Neven, M; Bomans, P; Romano, N; Maugeri, E A; Klupp, S C; Dehn, M H; Heinke, R M; Naubereit, P; Maira vidal, A; Vedia fernandez, M V; Ibanez garcia, P B; Bruyneel, B J E; Materna, T; Al-dahan, N; Alazemi, N; Carroll, R J; Babcock, C; Eleme, Z; Dhal, A; Valiente dobon, J J; Sahin, E; Goergen, A; Maj, A; Bednarczyk, P A; Borcea, C; Negoita, F; Suliman, G; Marginean, N M; Sotty, C O; Negret, A L; Nae, S A; Nita, C; Golubev, P I; Knyazev, A; Jost, C U; Petrik, K; Strisovska, J; Vaeyrynen, S A; Dracoulis, G D; Uher, J; Fernandez dominguez, B; Chakraborty, P; Avigo, R; Galaviz redondo, D; Castro ribeiro da silva, M; Bernards, C W; Falahat, S; Lekovic, F; Dorrer, H J; Derkx, X; Angus, L J; Sandhu, K S; Gregor, E; Byrne, D J; Haas, H; Lourenco, A A; Sousa pereira, S M; Sousa, J B; De melo mendonca, T M; Tavares de sousa, C; Guerreiro dos santos oliveira custodio, L M; Da rocha rodrigues, P M; Yamaguchi, T; Thompson, P C; Rosenbusch, M; Wienholtz, F; Fischer, P; Iwanicki, J S; Rusek, K M; Hanstorp, D; Severijns, N; Vanpoucke, B R S; Finlay, P E J; Park, S H; Warr, N V; Doornenbal, P C; Imig, A; Seidlitz, M; Moschner, K; Vogt, A; Kaya, L; Martel bravo, I; Orduz, A K; Serot, O; Majola, S N; Litvinov, Y; Bommert, M; Hensel, S; Markevich, V; Nishio, K; Ota, S; Matos, I; Zenkevich, A; Picado sandi, E; Forstner, O


    The experiments aim at a broad exploration of the properties of atomic nuclei far away from the region of beta stability. Furthermore, the unique radioactive beams of over 60~elements produced at the on-line isotope separators ISOLDE-2 and ISOLDE-3 are used in a wide programme of atomic, solid state and surface physics. Around 300 scientists are involved in the project, coming from about 70 laboratories. \\\\ \\\\ The electromagnetic isotope separators are connected on-line with their production targets in the extracted 600 MeV proton or 910~MeV Helium-3 beam of the Synchro-Cyclotron. Secondary beams of radioactive isotopes are available at the facility in intensities of 10$^1

  17. Acoustical Imaging

    CERN Document Server

    Litniewski, Jerzy; Kujawska, Tamara; 31st International Symposium on Acoustical Imaging


    The International Symposium on Acoustical Imaging is a unique forum for advanced research, covering new technologies, developments, methods and theories in all areas of acoustics. This interdisciplinary Symposium has been taking place continuously since 1968. In the course of the years the proceedings volumes in the Acoustical Imaging Series have become a reference for cutting-edge research in the field. In 2011 the 31st International Symposium on Acoustical Imaging was held in Warsaw, Poland, April 10-13. Offering both a broad perspective on the state-of-the-art as well as  in-depth research contributions by the specialists in the field, this Volume 31 in the Series contains an excellent collection of papers in six major categories: Biological and Medical Imaging Physics and Mathematics of Acoustical Imaging Acoustic Microscopy Transducers and Arrays Nondestructive Evaluation and Industrial Applications Underwater Imaging

  18. Seismo-acoustic evidence for an avalanche driven phreatic eruption through a beheaded hydrothermal system: An example from the 2012 Tongariro eruption (United States)

    Jolly, A.D.; Jousset, P.; Lyons, J.J.; Carniel, R.; Fournier, R.; Fry, B.; Miller, C.


    The 6 August 2012 Te Maari eruption comprises a complex eruption sequence including multiple eruption pulses, a debris avalanche that propagated ~ 2 km from the vent, and the formation of a 500 m long, arcuate chasm, located ~ 300 m from the main eruption vent. The eruption included 6 distinct impulses that were coherent across a local infrasound network marking the eruption onset at 11:52:18 (all times UTC). An eruption energy release of ~ 3 × 1012 J was calculated using a body wave equation for radiated seismic energy. A similar calculation based on the infrasound record, shows that ~ 90% of the acoustic energy was released from three impulses at onset times 11:52:20 (~ 20% of total eruption energy), 11:52:27 (~ 50%), and 11:52:31 (~ 20%). These energy impulses may coincide with eyewitness accounts describing an initial eastward directed blast, followed by a westward directed blast, and a final vertical blast. Pre-eruption seismic activity includes numerous small unlocatable micro-earthquakes that began at 11:46:50. Two larger high frequency earthquakes were recorded at 11:49:06 and 11:49:21 followed directly by a third earthquake at 11:50:17. The first event was located within the scarp based on an arrival time location from good first P arrival times and probably represents the onset of the debris avalanche. The third event was a tornillo, characterised by a 0.8 Hz single frequency resonance, and has a resonator attenuation factor of Q ~ 40, consistent with a bubbly fluid filled resonator. This contrasts with a similar tornillo event occurring 2.5 weeks earlier having Q ~ 250–1000, consistent with a dusty gas charged resonator. We surmise from pre-eruption seismicity, and the observed attenuation change, that the debris avalanche resulted from the influx of fluids into the hydrothermal system, causing destabilisation and failure. The beheaded hydrothermal system may have then caused depressurisation frothing of the remaining gas charged system leading to the

  19. Acoustic textiles

    CERN Document Server

    Nayak, Rajkishore


    This book highlights the manufacturing and applications of acoustic textiles in various industries. It also includes examples from different industries in which acoustic textiles can be used to absorb noise and help reduce the impact of noise at the workplace. Given the importance of noise reduction in the working environment in several industries, the book offers a valuable guide for companies, educators and researchers involved with acoustic materials.

  20. Acoustic biosensors


    Fogel, Ronen; Limson, Janice; Seshia, Ashwin A.


    Resonant and acoustic wave devices have been researched for several decades for application in the gravimetric sensing of a variety of biological and chemical analytes. These devices operate by coupling the measurand (e.g. analyte adsorption) as a modulation in the physical properties of the acoustic wave (e.g. resonant frequency, acoustic velocity, dissipation) that can then be correlated with the amount of adsorbed analyte. These devices can also be miniaturized with advantages in terms of ...

  1. Reactor Physics Programme

    Energy Technology Data Exchange (ETDEWEB)

    De Raedt, C


    The Reactor Physics and Department of SCK-CEN offers expertise in various areas of reactor physics, in particular in neutronics calculations, reactor dosimetry, reactor operation, reactor safety and control and non-destructive analysis on reactor fuel. This expertise is applied within the Reactor Physics and MYRRHA Research Department's own research projects in the VENUS critical facility, in the BR1 reactor and in the MYRRHA project (this project aims at designing a prototype Accelerator Driven System). Available expertise is also used in programmes external to the Department such as the reactor pressure steel vessel programme, the BR2 reactor dosimetry, and the preparation and interpretation of irradiation experiments. Progress and achievements in 1999 in the following areas are reported on: (1) investigations on the use of military plutonium in commercial power reactors; (2) neutron and gamma calculations performed for BR-2 and for other reactors; (3) the updating of neutron and gamma cross-section libraries; (4) the implementation of reactor codes; (6) the management of the UNIX workstations; and (6) fuel cycle studies.

  2. Acoustofluidics 14: Applications of acoustic streaming in microfluidic devices. (United States)

    Wiklund, Martin; Green, Roy; Ohlin, Mathias


    In part 14 of the tutorial series "Acoustofluidics--exploiting ultrasonic standing wave forces and acoustic streaming in microfluidic systems for cell and particle manipulation", we provide a qualitative description of acoustic streaming and review its applications in lab-on-a-chip devices. The paper covers boundary layer driven streaming, including Schlichting and Rayleigh streaming, Eckart streaming in the bulk fluid, cavitation microstreaming and surface-acoustic-wave-driven streaming.

  3. Radiation acoustics

    CERN Document Server

    Lyamshev, Leonid M


    Radiation acoustics is a developing field lying at the intersection of acoustics, high-energy physics, nuclear physics, and condensed matter physics. Radiation Acoustics is among the first books to address this promising field of study, and the first to collect all of the most significant results achieved since research in this area began in earnest in the 1970s.The book begins by reviewing the data on elementary particles, absorption of penetrating radiation in a substance, and the mechanisms of acoustic radiation excitation. The next seven chapters present a theoretical treatment of thermoradiation sound generation in condensed media under the action of modulated penetrating radiation and radiation pulses. The author explores particular features of the acoustic fields of moving thermoradiation sound sources, sound excitation by single high-energy particles, and the efficiency and optimal conditions of thermoradiation sound generation. Experimental results follow the theoretical discussions, and these clearl...

  4. Test-driven programming (United States)

    Georgiev, Bozhidar; Georgieva, Adriana


    In this paper, are presented some possibilities concerning the implementation of a test-driven development as a programming method. Here is offered a different point of view for creation of advanced programming techniques (build tests before programming source with all necessary software tools and modules respectively). Therefore, this nontraditional approach for easier programmer's work through building tests at first is preferable way of software development. This approach allows comparatively simple programming (applied with different object-oriented programming languages as for example JAVA, XML, PYTHON etc.). It is predictable way to develop software tools and to provide help about creating better software that is also easier to maintain. Test-driven programming is able to replace more complicated casual paradigms, used by many programmers.

  5. High-Fidelity Prediction of Launch Vehicle Lift-off Acoustic Environment Project (United States)

    National Aeronautics and Space Administration — Launch vehicles experience extreme acoustic loads during liftoff driven by the interaction of rocket plumes and plume-generated acoustic waves with ground...

  6. Acoustical Imaging

    CERN Document Server

    Akiyama, Iwaki


    The 29th International Symposium on Acoustical Imaging was held in Shonan Village, Kanagawa, Japan, April 15-18, 2007. This interdisciplinary Symposium has been taking place every two years since 1968 and forms a unique forum for advanced research, covering new technologies, developments, methods and theories in all areas of acoustics. In the course of the years the volumes in the Acoustical Imaging Series have developed and become well-known and appreciated reference works. Offering both a broad perspective on the state-of-the-art in the field as well as an in-depth look at its leading edge research, this Volume 29 in the Series contains again an excellent collection of seventy papers presented in nine major categories: Strain Imaging Biological and Medical Applications Acoustic Microscopy Non-Destructive Evaluation and Industrial Applications Components and Systems Geophysics and Underwater Imaging Physics and Mathematics Medical Image Analysis FDTD method and Other Numerical Simulations Audience Researcher...

  7. Battlefield acoustics

    CERN Document Server

    Damarla, Thyagaraju


    This book presents all aspects of situational awareness in a battlefield using acoustic signals. It starts by presenting the science behind understanding and interpretation of sound signals. The book then goes on to provide various signal processing techniques used in acoustics to find the direction of sound source, localize gunfire, track vehicles, and detect people. The necessary mathematical background and various classification and fusion techniques are presented. The book contains majority of the things one would need to process acoustic signals for all aspects of situational awareness in one location. The book also presents array theory, which is pivotal in finding the direction of arrival of acoustic signals. In addition, the book presents techniques to fuse the information from multiple homogeneous/heterogeneous sensors for better detection. MATLAB code is provided for majority of the real application, which is a valuable resource in not only understanding the theory but readers, can also use the code...

  8. Acoustics Research (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Fisheries acoustics data are collected from more than 200 sea-days each year aboard the FRV DELAWARE II and FRV ALBATROSS IV (decommissioned) and the FSV Henry B....

  9. Room Acoustics (United States)

    Kuttruff, Heinrich; Mommertz, Eckard

    The traditional task of room acoustics is to create or formulate conditions which ensure the best possible propagation of sound in a room from a sound source to a listener. Thus, objects of room acoustics are in particular assembly halls of all kinds, such as auditoria and lecture halls, conference rooms, theaters, concert halls or churches. Already at this point, it has to be pointed out that these conditions essentially depend on the question if speech or music should be transmitted; in the first case, the criterion for transmission quality is good speech intelligibility, in the other case, however, the success of room-acoustical efforts depends on other factors that cannot be quantified that easily, not least it also depends on the hearing habits of the listeners. In any case, absolutely "good acoustics" of a room do not exist.

  10. Holograms for acoustics (United States)

    Melde, Kai; Mark, Andrew G.; Qiu, Tian; Fischer, Peer


    Holographic techniques are fundamental to applications such as volumetric displays, high-density data storage and optical tweezers that require spatial control of intricate optical or acoustic fields within a three-dimensional volume. The basis of holography is spatial storage of the phase and/or amplitude profile of the desired wavefront in a manner that allows that wavefront to be reconstructed by interference when the hologram is illuminated with a suitable coherent source. Modern computer-generated holography skips the process of recording a hologram from a physical scene, and instead calculates the required phase profile before rendering it for reconstruction. In ultrasound applications, the phase profile is typically generated by discrete and independently driven ultrasound sources; however, these can only be used in small numbers, which limits the complexity or degrees of freedom that can be attained in the wavefront. Here we introduce monolithic acoustic holograms, which can reconstruct diffraction-limited acoustic pressure fields and thus arbitrary ultrasound beams. We use rapid fabrication to craft the holograms and achieve reconstruction degrees of freedom two orders of magnitude higher than commercial phased array sources. The technique is inexpensive, appropriate for both transmission and reflection elements, and scales well to higher information content, larger aperture size and higher power. The complex three-dimensional pressure and phase distributions produced by these acoustic holograms allow us to demonstrate new approaches to controlled ultrasonic manipulation of solids in water, and of liquids and solids in air. We expect that acoustic holograms will enable new capabilities in beam-steering and the contactless transfer of power, improve medical imaging, and drive new applications of ultrasound.

  11. Acoustic biosensors (United States)

    Fogel, Ronen; Seshia, Ashwin A.


    Resonant and acoustic wave devices have been researched for several decades for application in the gravimetric sensing of a variety of biological and chemical analytes. These devices operate by coupling the measurand (e.g. analyte adsorption) as a modulation in the physical properties of the acoustic wave (e.g. resonant frequency, acoustic velocity, dissipation) that can then be correlated with the amount of adsorbed analyte. These devices can also be miniaturized with advantages in terms of cost, size and scalability, as well as potential additional features including integration with microfluidics and electronics, scaled sensitivities associated with smaller dimensions and higher operational frequencies, the ability to multiplex detection across arrays of hundreds of devices embedded in a single chip, increased throughput and the ability to interrogate a wider range of modes including within the same device. Additionally, device fabrication is often compatible with semiconductor volume batch manufacturing techniques enabling cost scalability and a high degree of precision and reproducibility in the manufacturing process. Integration with microfluidics handling also enables suitable sample pre-processing/separation/purification/amplification steps that could improve selectivity and the overall signal-to-noise ratio. Three device types are reviewed here: (i) bulk acoustic wave sensors, (ii) surface acoustic wave sensors, and (iii) micro/nano-electromechanical system (MEMS/NEMS) sensors. PMID:27365040

  12. Acoustic streaming jets: A scaling and dimensional analysis (United States)

    Botton, V.; Moudjed, B.; Henry, D.; Millet, S.; Ben-Hadid, H.; Garandet, J. P.


    We present our work on acoustic streaming free jets driven by ultrasonic beams in liquids. These jets are steady flows generated far from walls by progressive acoustic waves. As can be seen on figure 1, our set-up, denominated AStrID for Acoustic Streaming Investigation Device, is made of a water tank in which a 29 mm plane source emits continuous ultrasonic waves at typically 2 MHz. Our approach combines an experimental characterization of both the acoustic pressure field (hydrophone) and the obtained acoustic streaming velocity field (PIV visualization) on one hand, with CFD using an incompressible Navier-Stokes solver on the other hand.

  13. Acoustic streaming jets: A scaling and dimensional analysis

    Energy Technology Data Exchange (ETDEWEB)

    Botton, V., E-mail:; Henry, D.; Millet, S.; Ben-Hadid, H. [LMFA, UMR CNRS 5509, Université de Lyon, ECL/INSA Lyon/Univ. Lyon 1, 36 avenue Guy deCollongue, 69134 Ecully Cedex (France); Moudjed, B. [LMFA, UMR CNRS 5509, Université de Lyon, ECL/INSA Lyon/Univ. Lyon 1, 36 avenue Guy deCollongue, 69134 Ecully Cedex (France); LIEFT, CEA-Saclay, 91191 Gif-sur-Yvette cedex (France); Garandet, J. P. [LIEFT, CEA-Saclay, 91191 Gif-sur-Yvette cedex (France)


    We present our work on acoustic streaming free jets driven by ultrasonic beams in liquids. These jets are steady flows generated far from walls by progressive acoustic waves. As can be seen on figure 1, our set-up, denominated AStrID for Acoustic Streaming Investigation Device, is made of a water tank in which a 29 mm plane source emits continuous ultrasonic waves at typically 2 MHz. Our approach combines an experimental characterization of both the acoustic pressure field (hydrophone) and the obtained acoustic streaming velocity field (PIV visualization) on one hand, with CFD using an incompressible Navier-Stokes solver on the other hand.

  14. Olympic Partner Programme

    Institute of Scientific and Technical Information of China (English)


    @@ The Olympic Partner Programme (TOP) is an international Olympic marketing programme created by the International Olympic Committee (IOC),which includes the Organising Committees of the Games,the National Olympic Committees and the TOP Partners.

  15. Droplets Acoustics

    CERN Document Server

    Dahan, Raphael; Carmon, Tal


    Contrary to their capillary resonances (Rayleigh, 1879) and their optical resonances (Ashkin, 1977), droplets acoustical resonances were rarely considered. Here we experimentally excite, for the first time, the acoustical resonances of a droplet that relies on sound instead of capillary waves. Droplets vibrations at 37 MHz rates and 100 quality factor are optically excited and interrogated at an optical threshold of 68 microWatt. Our vibrations span a spectral band that is 1000 times higher when compared with drops previously-studied capillary vibration.

  16. UNESCO's Ethics Education Programme.

    NARCIS (Netherlands)

    Have, H.A.M.J. ten


    Unesco initiated the Ethics Education Programme in 2004 at the request of member states to reinforce and increase the capacities in the area of ethics teaching. The programme is focused on providing detailed information about existing teaching programmes. It also develops and promotes teaching throu

  17. Pulsed-Source Interferometry in Acoustic Imaging (United States)

    Shcheglov, Kirill; Gutierrez, Roman; Tang, Tony K.


    A combination of pulsed-source interferometry and acoustic diffraction has been proposed for use in imaging subsurface microscopic defects and other features in such diverse objects as integrated-circuit chips, specimens of materials, and mechanical parts. A specimen to be inspected by this technique would be mounted with its bottom side in contact with an acoustic transducer driven by a continuous-wave acoustic signal at a suitable frequency, which could be as low as a megahertz or as high as a few hundred gigahertz. The top side of the specimen would be coupled to an object that would have a flat (when not vibrating) top surface and that would serve as the acoustical analog of an optical medium (in effect, an acoustical "optic").

  18. Product Sound: Acoustically pleasant motor drives

    DEFF Research Database (Denmark)

    Mathe, Laszlo

    The work in this thesis is focused on the acoustic noise generated by electrical motors driven by a pulse width modulated (PWM) power electronic inverter. In a usual inverter based electrical drive, the modulation uses fixed switching frequency; that introduces a set of harmonics in the acoustic...... spectra transforming the acoustic noise generated by the motor in a strong whistling noise. To maintain high efficiency for the entire drive, the switching frequency is typically kept around 4 kHz. However, this is the range where the human ear is the most sensitive. The main goal of this thesis...... is to ameliorate this whistling acoustic noise, while maintaining the efficiency of the drive. The first chapter of the report is an introductory chapter where the motivation, objectives, limitations and an overview on electrical motor acoustics are presented. A list of main contributions of this PhD project...

  19. Acoustic dose and acoustic dose-rate. (United States)

    Duck, Francis


    Acoustic dose is defined as the energy deposited by absorption of an acoustic wave per unit mass of the medium supporting the wave. Expressions for acoustic dose and acoustic dose-rate are given for plane-wave conditions, including temporal and frequency dependencies of energy deposition. The relationship between the acoustic dose-rate and the resulting temperature increase is explored, as is the relationship between acoustic dose-rate and radiation force. Energy transfer from the wave to the medium by means of acoustic cavitation is considered, and an approach is proposed in principle that could allow cavitation to be included within the proposed definitions of acoustic dose and acoustic dose-rate.

  20. Finnish bioenergy research programme

    Energy Technology Data Exchange (ETDEWEB)

    Asplund, D. [VTT Energy, Jyvaeskylae (Finland)


    Finland is a leading country in the use of biofuels and has excellent opportunities to increase the use of biofuels by up to 25-30 %. The Finnish Government has set an objective for the promotion of bioenergy. The aim is to increase the use of bioenergy by about 25 % from the present level by 2005, and the increment corresponds to 1.5 million tonnes of oil equivalent (toe) per year. The R and D work has been considered as an important factor to achieve this ambitious goal. Energy research was organised into a series of research programmes in 1988 in accordance with the proposal of Finnish Energy Research Committee. The object of the research programmes is to enhance research activities and to bundle individual projects together into larger research packages. The common target of the Finnish energy research programmes is to proceed from basic and applied research to product development and pilot operation, and after that to the first commercial applications, e.g. demonstrations. As the organisation of energy research to programmes has led to good results, the Finnish Ministry of Trade and Industry decided to go on with this practice by launching new six-year programmes in 1993-1998. One of these programmes is the Bioenergy Research Programme and the co-ordination of this programme is carried out by VTT Energy. Besides VTT Energy the Finnish Forest Research Institute, Work Efficiency Institute, Metsaeteho and University of Joensuu are participating in the programme 7 refs.

  1. Ultrafast magnetoelastic probing of surface acoustic transients

    NARCIS (Netherlands)

    Janusonis, J.; Chang, C. L.; Jansma, T.; Gatilova, A.; Vlasov, V. S.; Lomonosov, A. M.; Temnov, V. V.; Tobey, R. I.


    We generate in-plane magnetoelastic waves in nickel films using the all-optical transient grating technique. When performed on amorphous glass substrates, two dominant magnetoelastic excitations can be resonantly driven by the underlying elastic distortions, the Rayleigh surface acoustic wave and th

  2. SET-Routes programme

    CERN Multimedia

    CERN audiovisual service


    The SET-Routes programme, launched in 2007 with the goal of attracting girls and young women to careers in science, came to an end in April this year. The result of a collaboration between EMBL, EMBO and CERN, the programme established a network of "ambassadors", women scientists who went out to talk about their careers in science at schools and universities across Europe.

  3. Programmable Logic Controllers. (United States)

    Insolia, Gerard; Anderson, Kathleen

    This document contains a 40-hour course in programmable logic controllers (PLC), developed for a business-industry technology resource center for firms in eastern Pennsylvania by Northampton Community College. The 10 units of the course cover the following: (1) introduction to programmable logic controllers; (2) DOS primer; (3) prerequisite…

  4. Acoustic noise simulation for switched reluctance motors with audible output p

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, P.O.; Blaabjerg, F.; Pedersen, J.K.; Kjaer, P.C. [Aalborg Univ., Inst. of Energy Technology (Denmark); Miller, T.J.E. [Univ. of Glasgow, SPEED Lab., Dep. of Electronics and Electrical Engineering (United Kingdom)


    Acoustic noise in switched reluctance motors is one of the last problems which have to be solved before a more widespread use will come. In order to design a low noise Switched Reluctance Motor drive, simulation tools are needed, and this paper describes a design programme where acoustic noise of electromagnetic origin can be estimated and even be heard by the motor-designer. The design program is based on a new, simple developed vibrational and acoustic model where the parameters can be calculated based on the geometry of the motor. The vibrational and acoustic model is verified in both time and frequency domain where vibrations and acoustic noise have been considered. (au)


    Directory of Open Access Journals (Sweden)


    Full Text Available Centre for Education and Rehabilitation of Physi­cally Handicapped Children and Adolescents Kamnik (Zavod za usposabljanje invalidne mlad­ine Kamnik; hereinafter: ZUIM perform verified or state-ap­proved programme the Rehabilitation practical pro­gramme. The programme is intended for all those young people, who have completed primary school education, but cannot continue regular schooling in secondary school pro­grammes. The programme con­sists of several equivalent parts: education, practical work, train­ing work, health, therapeutic, psychologi­cal, and other activities. For every beginner in the first month of education members of the operative team create an individualized programme, which in­cludes individualized school work, individualized training programme, and other expert activities. The programme can last for 6 years maximum, it can however be completed earlier, when the op­erative team feels the training is no longer neces­sary. Pro­gress of a young person is what matters the most, and if there is no progress, the training is brought to an end. Training of young people in the Rehabilitation practical programme is only the be­ginning. The country will have to start considering social enter­prises, which are found elsewhere in the world, for example in Scandinavian countries and in the USA.

  6. Use of acoustic vortices in acoustic levitation

    DEFF Research Database (Denmark)

    Cutanda Henriquez, Vicente; Santillan, Arturo Orozco; Juhl, Peter Møller


    Acoustic fields are known to exert forces on the surfaces of objects. These forces are noticeable if the sound pressure is sufficiently high. Two phenomena where acoustic forces are relevant are: i) acoustic levitation, where strong standing waves can hold small objects at certain positions......, counterbalancing their weight, and ii) acoustic vortices, spinning sound fields that can impinge angular momentum and cause rotation of objects. In this contribution, both force-creating sound fields are studied by means of numerical simulations. The Boundary Element Method is employed to this end. The simulation...... of acoustical vortices uses an efficient numerical implementation based on the superposition of two orthogonal sound fields with a delay of 90° between them. It is shown that acoustic levitation and the use of acoustic vortices can be combined to manipulate objects in an efficient and controlled manner without...

  7. Acoustic telemetry.

    Energy Technology Data Exchange (ETDEWEB)

    Drumheller, Douglas Schaeffer; Kuszmaul, Scott S.


    Broadcasting messages through the earth is a daunting task. Indeed, broadcasting a normal telephone conversion through the earth by wireless means is impossible with todays technology. Most of us don't care, but some do. Industries that drill into the earth need wireless communication to broadcast navigation parameters. This allows them to steer their drill bits. They also need information about the natural formation that they are drilling. Measurements of parameters such as pressure, temperature, and gamma radiation levels can tell them if they have found a valuable resource such as a geothermal reservoir or a stratum bearing natural gas. Wireless communication methods are available to the drilling industry. Information is broadcast via either pressure waves in the drilling fluid or electromagnetic waves in the earth and well tubing. Data transmission can only travel one way at rates around a few baud. Given that normal Internet telephone modems operate near 20,000 baud, these data rates are truly very slow. Moreover, communication is often interrupted or permanently blocked by drilling conditions or natural formation properties. Here we describe a tool that communicates with stress waves traveling through the steel drill pipe and production tubing in the well. It's based on an old idea called Acoustic Telemetry. But what we present here is more than an idea. This tool exists, it's drilled several wells, and it works. Currently, it's the first and only acoustic telemetry tool that can withstand the drilling environment. It broadcasts one way over a limited range at much faster rates than existing methods, but we also know how build a system that can communicate both up and down wells of indefinite length.

  8. Greek Teachers Programme 2015

    CERN Multimedia

    Hoch, Michael


    The 3rd edition of this year's Greek Teachers Programme was co-organized by CERN Education Group and the Hellenic Physical Society and took place from 8 to 12 November 2015. The programme targets physics high-school teachers from all over Greece. It aims to help teachers inspire the next generation of scientists and engineers by motivating their students to understand and appreciate how science works at the world's largest physics laboratory, whereby increasing their interest in pursuing studies in STEM fields in secondary and post-secondary education. 33 teachers took part in this programme which comprised lectures by Greek members of the CERN scientific community, with visits to experimental facilities, hands-on activities and dedicated sessions on effective and creative ways through which participants may bring physics, particle physics and CERN closer to their school classroom. In 2015, more than 100 teachers took part in the three editions of the Greek Teachers Programme.

  9. The HAWC GRB Programme (United States)

    Lennarz, D.; Taboada, I.


    HAWC is a very-high-energy gamma-ray extensive air shower detector located in central Mexico at an altitude of 4,100 m above sea level. This contribution summarises recent results of the HAWC GRB programme.

  10. FAST joins Breakthrough programme (United States)

    Banks, Michael


    The 180m Five-hundred-meter Aperture Spherical radio Telescope (FAST) - the world's largest single-aperture radio receiver - has become part of the Breakthrough Listen programme, which launched in July 2015 to look for intelligent life beyond Earth.

  11. Elukestva õppe programm : Erasmus+

    Index Scriptorium Estoniae


    Erasmus+ programm liidab senised koostööprogrammid „Euroopa elukestva õppe programm“, „Euroopa Noored“ ning Euroopa komisjoni rahvusvahelised kõrgharidusprogrammid. Elukestva õppe programmi 2013 kokkuvõte

  12. Fellows, Associates & Students Programmes

    CERN Document Server


    The present document reviews the CERN Fellows, Associates and Students Programmes emphasizing the developments since 2000, when the previous review was presented to the Scientific Policy Committee, Finance Committee and Council (CERN/2325), and makes proposals for the coming five years. In summary, it is proposed to â?¢ Simplify the payment scheme for the Paid Scientific Associates Programme, which will no longer depend on candidateâ??s home support and age; â?¢ Broaden the scope of the Fellowship Programme, in order to facilitate the recruitment of young graduates in computing and engineering. Age-related eligibility conditions and payment levels will be replaced with experience-based criteria; â?¢ Modify subsistence rates for the Doctoral and Technical Student Programme in order to harmonize CERNâ??s payment levels with those offered by other research establishments. This document is presented for discussion and recommendation by the Scientific Policy Committee and approval by the Council. Additiona...

  13. Visual Basic educational programme


    Pranaitis, Arūnas


    Visual basic educational programme Informational Technologies has become such a popular subject that they are applied in all works of life. However, Informational Technologies are still rarely used in the lessons at school. There are such reasons of the mentioned issue: · Insufficient base of computers, · The old software and its disadvantages, · The lack of computerized educational programmes. The aim of the work was to prove that it is actual to create computerized educat...

  14. Punch Card Programmable Microfluidics


    George Korir; Manu Prakash


    Small volume fluid handling in single and multiphase microfluidics provides a promising strategy for efficient bio-chemical assays, low-cost point-of-care diagnostics and new approaches to scientific discoveries. However multiple barriers exist towards low-cost field deployment of programmable microfluidics. Incorporating multiple pumps, mixers and discrete valve based control of nanoliter fluids and droplets in an integrated, programmable manner without additional required external component...

  15. Responsive acoustic surfaces

    DEFF Research Database (Denmark)

    Peters, Brady; Tamke, Martin; Nielsen, Stig Anton;


    Acoustic performance is defined by the parameter of reverberation time; however, this does not capture the acoustic experience in some types of open plan spaces. As many working and learning activities now take place in open plan spaces, it is important to be able to understand and design...... for the acoustic conditions of these spaces. This paper describes an experimental research project that studied the design processes necessary to design for sound. A responsive acoustic surface was designed, fabricated and tested. This acoustic surface was designed to create specific sonic effects. The design...... was simulated using custom integrated acoustic software and also using Odeon acoustic analysis software. The research demonstrates a method for designing space- and sound-defining surfaces, defines the concept of acoustic subspace, and suggests some new parameters for defining acoustic subspaces....

  16. Springer Handbook of Acoustics

    CERN Document Server

    Rossing, Thomas D


    Acoustics, the science of sound, has developed into a broad interdisciplinary field encompassing the academic disciplines of physics, engineering, psychology, speech, audiology, music, architecture, physiology, neuroscience, and others. The Springer Handbook of Acoustics is an unparalleled modern handbook reflecting this richly interdisciplinary nature edited by one of the acknowledged masters in the field, Thomas Rossing. Researchers and students benefit from the comprehensive contents spanning: animal acoustics including infrasound and ultrasound, environmental noise control, music and human speech and singing, physiological and psychological acoustics, architectural acoustics, physical and engineering acoustics, signal processing, medical acoustics, and ocean acoustics. This handbook reviews the most important areas of acoustics, with emphasis on current research. The authors of the various chapters are all experts in their fields. Each chapter is richly illustrated with figures and tables. The latest rese...

  17. Acoustic Spatiality

    Directory of Open Access Journals (Sweden)

    Brandon LaBelle


    Full Text Available Experiences of listening can be appreciated as intensely relational, bringing us into contact with surrounding events, bodies and things. Given that sound propagates and expands outwardly, as a set of oscillations from a particular source, listening carries with it a sensual intensity, whereby auditory phenomena deliver intrusive and disruptive as well as soothing and assuring experiences. The physicality characteristic of sound suggests a deeply impressionistic, locational "knowledge structure" – that is, the ways in which listening affords processes of exchange, of being in the world, and from which we extend ourselves. Sound, as physical energy reflecting and absorbing into the materiality around us, and even one's self, provides a rich platform for understanding place and emplacement. Sound is always already a trace of location.Such features of auditory experience give suggestion for what I may call an acoustical paradigm – how sound sets in motion not only the material world but also the flows of the imagination, lending to forces of signification and social structure, and figuring us in relation to each other. The relationality of sound brings us into a steady web of interferences, each of which announces the promise or problematic of being somewhere.

  18. Acoustic Neurinomas

    Directory of Open Access Journals (Sweden)

    Mohammad Faraji Rad


    Full Text Available Acoustic neuromas (AN are schwann cell-derived tumors that commonly arise from the vestibular portion of the eighth cranial nerve also known as vestibular schwannoma(VS causes unilateral hearing loss, tinnitus, vertigo and unsteadiness. In many cases, the tumor size may remain unchanged for many years following diagnosis, which is typically made by MRI. In the majority of cases the tumor is small, leaving the clinician and patient with the options of either serial scanning or active treatment by gamma knife radiosurgery (GKR or microneurosurgery. Despite the vast number of published treatment reports, comparative studies are few. The predominant clinical endpoints of AN treatment include tumor control, facial nerve function and hearing preservation. Less focus has been put on symptom relief and health-related quality of life (QOL. It is uncertain if treating a small tumor leaves the patient with a better chance of obtaining relief from future hearing loss, vertigo or tinnitus than by observing it without treatment.   In this paper we review the literature for the natural course, the treatment alternatives and the results of AN. Finally, we present our experience with a management strategy applied for more than 30 years.

  19. Acoustic spin pumping in magnetoelectric bulk acoustic wave resonator

    Directory of Open Access Journals (Sweden)

    N. I. Polzikova


    Full Text Available We present the generation and detection of spin currents by using magnetoelastic resonance excitation in a magnetoelectric composite high overtone bulk acoustic wave (BAW resonator (HBAR formed by a Al-ZnO-Al-GGG-YIG-Pt structure. Transversal BAW drives magnetization oscillations in YIG film at a given resonant magnetic field, and the resonant magneto-elastic coupling establishes the spin-current generation at the Pt/YIG interface. Due to the inverse spin Hall effect (ISHE this BAW-driven spin current is converted to a dc voltage in the Pt layer. The dependence of the measured voltage both on magnetic field and frequency has a resonant character. The voltage is determined by the acoustic power in HBAR and changes its sign upon magnetic field reversal. We compare the experimentally observed amplitudes of the ISHE electrical field achieved by our method and other approaches to spin current generation that use surface acoustic waves and microwave resonators for ferromagnetic resonance excitation, with the theoretically expected values.

  20. Acoustic source for generating an acoustic beam

    Energy Technology Data Exchange (ETDEWEB)

    Vu, Cung Khac; Sinha, Dipen N.; Pantea, Cristian


    An acoustic source for generating an acoustic beam includes a housing; a plurality of spaced apart piezo-electric layers disposed within the housing; and a non-linear medium filling between the plurality of layers. Each of the plurality of piezoelectric layers is configured to generate an acoustic wave. The non-linear medium and the plurality of piezo-electric material layers have a matching impedance so as to enhance a transmission of the acoustic wave generated by each of plurality of layers through the remaining plurality of layers.

  1. Canonical Acoustics and Its Application to Surface Acoustic Wave on Acoustic Metamaterials (United States)

    Shen, Jian Qi


    In a conventional formalism of acoustics, acoustic pressure p and velocity field u are used for characterizing acoustic waves propagating inside elastic/acoustic materials. We shall treat some fundamental problems relevant to acoustic wave propagation alternatively by using canonical acoustics (a more concise and compact formalism of acoustic dynamics), in which an acoustic scalar potential and an acoustic vector potential (Φ ,V), instead of the conventional acoustic field quantities such as acoustic pressure and velocity field (p,u) for characterizing acoustic waves, have been defined as the fundamental variables. The canonical formalism of the acoustic energy-momentum tensor is derived in terms of the acoustic potentials. Both the acoustic Hamiltonian density and the acoustic Lagrangian density have been defined, and based on this formulation, the acoustic wave quantization in a fluid is also developed. Such a formalism of acoustic potentials is employed to the problem of negative-mass-density assisted surface acoustic wave that is a highly localized surface bound state (an eigenstate of the acoustic wave equations). Since such a surface acoustic wave can be strongly confined to an interface between an acoustic metamaterial (e.g., fluid-solid composite structures with a negative dynamical mass density) and an ordinary material (with a positive mass density), it will give rise to an effect of acoustic field enhancement on the acoustic interface, and would have potential applications in acoustic device design for acoustic wave control.

  2. Punch Card Programmable Microfluidics

    CERN Document Server

    Korir, George


    Small volume fluid handling in single and multiphase microfluidics provides a promising strategy for efficient bio-chemical assays, low-cost point-of-care diagnostics and new approaches to scientific discoveries. However multiple barriers exist towards low-cost field deployment of programmable microfluidics. Incorporating multiple pumps, mixers and discrete valve based control of nanoliter fluids and droplets in an integrated, programmable manner without additional required external components has remained elusive. Combining the idea of punch card programming with arbitrary fluid control, here we describe a self-contained, hand-crank powered, multiplex and robust programmable microfluidic platform. A paper tape encodes information as a series of punched holes. A mechanical reader/actuator reads these paper tapes and correspondingly executes a series of operations onto a microfluidic chip coupled to the platform in a plug-and-play fashion. Enabled by the complexity of codes that can be represented by a series ...

  3. External Mobility Programme

    CERN Multimedia

    HR Department


    Every year, a significant number of highly-skilled staff members leave the Organization and offer their talents on the European job market. CERN is launching a programme aiming to help staff members to whom the Organization cannot offer an indefinite contract in the transition towards their next employment. The programme, which is based on the establishment of a number of partnerships with potential employers in the private sector, will run on a voluntary basis. Staff members who have received confirmation that they will not be offered an indefinite contract and who are interested in availing themselves of the opportunities offered by the programme, are invited to enrol by following the procedure described at: Applications will be processed in the strictest confidence by the Human Resources Department and eligible profiles will then be made available to partner companies for recruitment purposes. Any subsequent ...

  4. Atlantic Herring Acoustic Surveys (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NEFSC Advanced Sampling Technologies Research Group conducts annual fisheries acoustic surveys using state-of-the-art acoustic, midwater trawling, and underwater...

  5. Computer mathematics for programmers

    CERN Document Server

    Abney, Darrell H; Sibrel, Donald W


    Computer Mathematics for Programmers presents the Mathematics that is essential to the computer programmer.The book is comprised of 10 chapters. The first chapter introduces several computer number systems. Chapter 2 shows how to perform arithmetic operations using the number systems introduced in Chapter 1. The third chapter covers the way numbers are stored in computers, how the computer performs arithmetic on real numbers and integers, and how round-off errors are generated in computer programs. Chapter 4 details the use of algorithms and flowcharting as problem-solving tools for computer p

  6. Air Quality Monitoring Programme

    DEFF Research Database (Denmark)

    Kemp, K.; Palmgren, F.

    The Danish Air Quality Monitoring Programme (LMP IV) has been revised in accordance with the Framework Directive and the first three daughter directives of SO2, NOx/NO2, PM10, lead, benzene, CO and ozone. PM10 samplers are under installation and the installation will be completed during 2002....... The PM10 results from 2000 are spares, only TSP are thus included in this report. The data sets for year 2000 is complete for many stations. The monitoring programme consists of 10 stations plus 2 extra stations under the Municipality of Copenhagen. The SO2 and lead levels are still decreasing and far...

  7. A programmer's geometry

    CERN Document Server

    Bowyer, Adrian


    A Programmer's Geometry provides a guide in programming geometric shapes. The book presents formulas and examples of computer representation and coding of geometry. Each of the nine chapters of the text deals with the representation and solution of a specific geometrical problem, such as areas, vectors, and volumes. The last chapter provides a brief discussion on generating image through a computer. The codes presented in the book are written in FORTRAN 77. The text will be of great use to programmers who are working on projects that involve geometric calculations.

  8. Acoustic Communications (ACOMMS) ATD (United States)


    develop and demonstrate emerging undersea acoustic communication technologies at operationally useful ranges and data rates. The secondary objective...Technology Demonstration program (ACOMMS ATD) was to demonstrate long range and moderate data rate underwater acoustic communications between a submarine...moderate data rate acoustic communications capability for tactical use between submarines, surface combatants, unmanned undersea vehicles (UUVs), and other

  9. Tutorial on architectural acoustics (United States)

    Shaw, Neil; Talaske, Rick; Bistafa, Sylvio


    This tutorial is intended to provide an overview of current knowledge and practice in architectural acoustics. Topics covered will include basic concepts and history, acoustics of small rooms (small rooms for speech such as classrooms and meeting rooms, music studios, small critical listening spaces such as home theatres) and the acoustics of large rooms (larger assembly halls, auditoria, and performance halls).

  10. SET-Routes programme

    CERN Multimedia

    Marietta Schupp, EMBL Photolab


    Dr Sabine Hentze, specialist in human genetics, giving an Insight Lecture entitled "Human Genetics – Diagnostics, Indications and Ethical Issues" on 23 September 2008 at EMBL Heidelberg. Activities in a achool in Budapest during a visit of Angela Bekesi, Ambassadors for the SET-Routes programme.

  11. VAM programme 14

    Energy Technology Data Exchange (ETDEWEB)

    Youngman, Michael [National Radiological Protection Board, Chilton (United Kingdom)


    Since 1988, the Department of Trade and Industry (DTI) has supported a Valid Analytical Measurement (VAM) initiative. VAM programming 14 is concerned with sampling and measurement of aerosols and particulates in the gas phase. The programme of work is summarised here. (author).

  12. The European Programme Manager

    DEFF Research Database (Denmark)

    Larson, Anne; Bergman, E.; Ehlers, S.;

    The publication is a result of a cooperation between organisations in six European countries with the aim to develop a common European education for programme managers. It contains of a description of the different elements of the education together with a number of case-studies from the counties...

  13. User programmable virtualized networks

    NARCIS (Netherlands)

    Meijer, R.J.; Strijkers, R.J.; Gommans, L.; Laat,


    This paper introduces the concept of a User Programmable Virtualized Network, which allows networks to deliver application specific services using network element components that developers can program as part of a users application. The use of special tokens in data or control packets is the basis

  14. Progressive Retirement Programme

    CERN Multimedia

    HR Department


    Following the Standing Concertation Committee meeting of 2 December 2008, please note that the Progressive Retirement Programme has been extended by one year, i.e. until 31 March 2010. Further information is available on : HR Department, tel. 73903

  15. En model for programmer

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak

    Dette undervisningsmateriale beskriver en model for, hvordan programmer er opbygget. Materialet er skrevet til brug i det gymnasiale forsøgsfag Informationsteknologi. Seneste version af dette undervisningsmateriale kan findes på http:// Tak til Elisabeth Husum for en kritisk...

  16. Acoustic metamaterials: From local resonances to broad horizons. (United States)

    Ma, Guancong; Sheng, Ping


    Within a time span of 15 years, acoustic metamaterials have emerged from academic curiosity to become an active field driven by scientific discoveries and diverse application potentials. This review traces the development of acoustic metamaterials from the initial findings of mass density and bulk modulus frequency dispersions in locally resonant structures to the diverse functionalities afforded by the perspective of negative constitutive parameter values, and their implications for acoustic wave behaviors. We survey the more recent developments, which include compact phase manipulation structures, superabsorption, and actively controllable metamaterials as well as the new directions on acoustic wave transport in moving fluid, elastic, and mechanical metamaterials, graphene-inspired metamaterials, and structures whose characteristics are best delineated by non-Hermitian Hamiltonians. Many of the novel acoustic metamaterial structures have transcended the original definition of metamaterials as arising from the collective manifestations of constituent resonating units, but they continue to extend wave manipulation functionalities beyond those found in nature.

  17. Acoustic elliptical cylindrical cloaks

    Institute of Scientific and Technical Information of China (English)

    Ma Hua; Qu Shao-Bo; Xu Zhuo; Wang Jia-Fu


    By making a comparison between the acoustic equations and the 2-dimensional (2D) Maxwell equations, we obtain the material parameter equations (MPE) for acoustic elliptical cylindrical cloaks. Both the theoretical results and the numerical results indicate that an elliptical cylindrical cloak can realize perfect acoustic invisibility when the spatial distributions of mass density and bulk modulus are exactly configured according to the proposed equations. The present work is the meaningful exploration of designing acoustic cloaks that are neither sphere nor circular cylinder in shape, and opens up possibilities for making complex and multiplex acoustic cloaks with simple models such as spheres, circular or elliptic cylinders.

  18. Indoor acoustic gain design (United States)

    Concha-Abarca, Justo Andres


    The design of sound reinforcement systems includes many variables and usually some of these variables are discussed. There are criteria to optimize the performance of the sound reinforcement systems under indoor conditions. The equivalent acoustic distance, the necessary acoustic gain, and the potential acoustic gain are parameters which must be adjusted with respect to the loudspeaker array, electric power and directionality of loudspeakers, the room acoustics conditions, the distance and distribution of the audience, and the type of the original sources. The design and installation of front of the house and monitoring systems have individual criteria. This article is about this criteria and it proposes general considerations for the indoor acoustic gain design.

  19. Automated design of programmable enzyme-driven DNA circuits

    NARCIS (Netherlands)

    Roekel, van Hendrik W.H.; Meijer, Lenny H.H.; Masroor, Saeed; Félix Garza, Zandra C.; Estévez-Torres, André; Rondelez, Yannick; Zagaris, Antonios; Peletier, Mark A.; Hilbers, Peter A.J.; Greef, de Tom F.A.


    Molecular programming allows for the bottom-up engineering of biochemical reaction networks in a controlled in vitro setting. These engineered biochemical reaction networks yield important insight in the design principles of biological systems and can potentially enrich molecular diagnostic systems.

  20. Frequency effects on the scale and behavior of acoustic streaming. (United States)

    Dentry, Michael B; Yeo, Leslie Y; Friend, James R


    Acoustic streaming underpins an exciting range of fluid manipulation phenomena of rapidly growing significance in microfluidics, where the streaming often assumes the form of a steady, laminar jet emanating from the device surface, driven by the attenuation of acoustic energy within the beam of sound propagating through the liquid. The frequencies used to drive such phenomena are often chosen ad hoc to accommodate fabrication and material issues. In this work, we seek a better understanding of the effects of sound frequency and power on acoustic streaming. We present and, using surface acoustic waves, experimentally verify a laminar jet model that is based on the turbulent jet model of Lighthill, which is appropriate for acoustic streaming seen at micro- to nanoscales, between 20 and 936 MHz and over a broad range of input power. Our model eliminates the critically problematic acoustic source singularity present in Lighthill's model, replacing it with a finite emission area and enabling determination of the streaming velocity close to the source. At high acoustic power P (and hence high jet Reynolds numbers ReJ associated with fast streaming), the laminar jet model predicts a one-half power dependence (U∼P1/2∼ ReJ) similar to the turbulent jet model. However, the laminar model may also be applied to jets produced at low powers-and hence low jet Reynolds numbers ReJ-where a linear relationship between the beam power and streaming velocity exists: U∼P∼ReJ2. The ability of the laminar jet model to predict the acoustic streaming behavior across a broad range of frequencies and power provides a useful tool in the analysis of microfluidics devices, explaining peculiar observations made by several researchers in the literature. In particular, by elucidating the effects of frequency on the scale of acoustically driven flows, we show that the choice of frequency is a vitally important consideration in the design of small-scale devices employing acoustic streaming

  1. Aurora europe's space exploration programme (United States)

    Ongaro, F.; Swings, J. P.; Condessa, R.


    What will happen after the ISS in terms of space exploration, specifically to the human presence beyond Earth? What will be the role of Europe in the future international venture to explore space? What are the most immediate actions to be undertaken in Europe in order to best profit from the efforts made through the participation in the ISS and to position Europe's capabilities according to its interests? As approved by the Ministers at the Edinburgh Council in November 2001, the European Space Exploration Programme - Aurora - is ESA's programme in charge of defining and implementing the long term plan for human and robotic exploration of the Solar system. The Aurora programme started in 2002 and extends until the end goal of Aurora: the first human mission to Mars, expected in the 2025-2030 time-frame. The approach of Aurora is to implement a robust development of technologies and robotic missions, in parallel to the utilization phase of the ISS, to prepare for a continuous and sustainable future of human space exploration (which shall include the Moon, Mars and the asteroids as targets), in which Europe will be a valuable partner. Two classes of missions are foreseen in the programme's strategy: Flagships, defined as major missions driving to soft landing, in-situ analysis, sample return from other planetary bodies and eventually human missions; and Arrows, defined as cost-capped, short development time missions to demonstrate new technologies or mission approaches, or to exploit opportunities for payloads on European or international missions. So far the participating national delegations have approved two Flagships (ExoMars and Mars Sample Return) and two Arrows (Earth Re-entry and Mars Aerocapture) for phase A industrial studies. Although the last call for ideas of Aurora resulted in the definition of two Flagship missions targeted to Mars, the next one might be aimed to the Moon. At this stage the role of the Moon, on the path of Mars exploration is not

  2. The INTEGRAL Core Observing Programme

    DEFF Research Database (Denmark)

    Winkler, C.; Gehrels, N.; Lund, Niels


    The Core Programme of the INTEGRAL mission is defined as the portion of the scientific programme covering the guaranteed time observations for the INTEGRAL Science Working Team. This paper describes the current status of the Core Programme preparations and summarizes the key elements...

  3. The ACIGA Data Analysis programme

    CERN Document Server

    Scott, S M; Cusack, B J; McClelland, D E; Scott, Susan M; Searle, Antony C; Cusack, Benedict J; Clelland, David E Mc


    The Data Analysis programme of the Australian Consortium for Interferometric Gravitational Astronomy (ACIGA) was set up in 1998 by the first author to complement the then existing ACIGA programmes working on suspension systems, lasers and optics, and detector configurations. The ACIGA Data Analysis programme continues to contribute significantly in the field; we present an overview of our activities.

  4. On-line surveillance of lubricants in bearings by means of surface acoustic waves. (United States)

    Lindner, Gerhard; Schmitt, Martin; Schubert, Josephine; Krempel, Sandro; Faustmann, Hendrik


    The acoustic wave propagation in bearings filled with lubricants and driven by pulsed excitation of surface acoustic waves has been investigated with respect to the presence and the distribution of different lubricants. Experimental setups, which are based on the mode conversion between surface acoustic waves and compression waves at the interface between a solid substrate of the bearing and a lubricant are described. The results of preliminary measurements at linear friction bearings, rotation ball bearings and axial cylinder roller bearings are presented.

  5. The Mathematica programmer

    CERN Document Server

    Maeder, Roman E


    The Mathematica Programmer covers the fundamental programming paradigms and applications of programming languages. This book is organized into two parts encompassing 10 chapters. Part 1 begins with an overview of the programming paradigms. This part also treats abstract data types, polymorphism and message passing, object-oriented programming, and relational databases. Part 2 looks into the practical aspects of programming languages, including in lists and power series, fractal curves, and minimal surfaces.This book will prove useful to mathematicians and computer scientists.

  6. Programmable mechanical metamaterials. (United States)

    Florijn, Bastiaan; Coulais, Corentin; van Hecke, Martin


    We create mechanical metamaterials whose response to uniaxial compression can be programmed by lateral confinement, allowing monotonic, nonmonotonic, and hysteretic behavior. These functionalities arise from a broken rotational symmetry which causes highly nonlinear coupling of deformations along the two primary axes of these metamaterials. We introduce a soft mechanism model which captures the programmable mechanics, and outline a general design strategy for confined mechanical metamaterials. Finally, we show how inhomogeneous confinement can be explored to create multistability and giant hysteresis.

  7. Punch card programmable microfluidics. (United States)

    Korir, George; Prakash, Manu


    Small volume fluid handling in single and multiphase microfluidics provides a promising strategy for efficient bio-chemical assays, low-cost point-of-care diagnostics and new approaches to scientific discoveries. However multiple barriers exist towards low-cost field deployment of programmable microfluidics. Incorporating multiple pumps, mixers and discrete valve based control of nanoliter fluids and droplets in an integrated, programmable manner without additional required external components has remained elusive. Combining the idea of punch card programming with arbitrary fluid control, here we describe a self-contained, hand-crank powered, multiplex and robust programmable microfluidic platform. A paper tape encodes information as a series of punched holes. A mechanical reader/actuator reads these paper tapes and correspondingly executes operations onto a microfluidic chip coupled to the platform in a plug-and-play fashion. Enabled by the complexity of codes that can be represented by a series of holes in punched paper tapes, we demonstrate independent control of 15 on-chip pumps with enhanced mixing, normally-closed valves and a novel on-demand impact-based droplet generator. We demonstrate robustness of operation by encoding a string of characters representing the word "PUNCHCARD MICROFLUIDICS" using the droplet generator. Multiplexing is demonstrated by implementing an example colorimetric water quality assays for pH, ammonia, nitrite and nitrate content in different water samples. With its portable and robust design, low cost and ease-of-use, we envision punch card programmable microfluidics will bring complex control of microfluidic chips into field-based applications in low-resource settings and in the hands of children around the world.

  8. Punch card programmable microfluidics.

    Directory of Open Access Journals (Sweden)

    George Korir

    Full Text Available Small volume fluid handling in single and multiphase microfluidics provides a promising strategy for efficient bio-chemical assays, low-cost point-of-care diagnostics and new approaches to scientific discoveries. However multiple barriers exist towards low-cost field deployment of programmable microfluidics. Incorporating multiple pumps, mixers and discrete valve based control of nanoliter fluids and droplets in an integrated, programmable manner without additional required external components has remained elusive. Combining the idea of punch card programming with arbitrary fluid control, here we describe a self-contained, hand-crank powered, multiplex and robust programmable microfluidic platform. A paper tape encodes information as a series of punched holes. A mechanical reader/actuator reads these paper tapes and correspondingly executes operations onto a microfluidic chip coupled to the platform in a plug-and-play fashion. Enabled by the complexity of codes that can be represented by a series of holes in punched paper tapes, we demonstrate independent control of 15 on-chip pumps with enhanced mixing, normally-closed valves and a novel on-demand impact-based droplet generator. We demonstrate robustness of operation by encoding a string of characters representing the word "PUNCHCARD MICROFLUIDICS" using the droplet generator. Multiplexing is demonstrated by implementing an example colorimetric water quality assays for pH, ammonia, nitrite and nitrate content in different water samples. With its portable and robust design, low cost and ease-of-use, we envision punch card programmable microfluidics will bring complex control of microfluidic chips into field-based applications in low-resource settings and in the hands of children around the world.


    CERN Multimedia

    Academic Training; Tel. 73127


    Main Auditorium bldg. 500 Date Time Lecturer Title Monday 13 August 9:15 10:15 11:15 Student Session (3/3) Course Review Course Review Tuesday 14 August 16:00 Poster Session Further information can be obtained on the web at the following URL: Summer Student Lecture ProgrammeSummer Student Lectures are available at:

  10. NSF announces diversity programme (United States)

    Kruesi, Liz


    The US National Science Foundation (NSF) has initiated a new funding programme that will create schemes to increase diversity in science, technology, engineering and mathematics (STEM). The initiative - Inclusion across the Nation of Communities of Learners of Underrepresented Discoverers in Engineering and Science (INCLUDES) - aims to increase the participation of women, those with a low socioeconomic status, people with disabilities and those from minority racial backgrounds.

  11. A new video programme

    CERN Multimedia

    CERN video productions


    "What's new @ CERN?", a new monthly video programme, will be broadcast on the Monday of every month on Aimed at the general public, the programme will cover the latest CERN news, with guests and explanatory features. Tune in on Monday 3 October at 4 pm (CET) to see the programme in English, and then at 4:20 pm (CET) for the French version.   var flash_video_player=get_video_player_path(); insert_player_for_external('Video/Public/Movies/2011/CERN-MOVIE-2011-129/CERN-MOVIE-2011-129-0753-kbps-640x360-25-fps-audio-64-kbps-44-kHz-stereo', 'mms://', 'false', 480, 360, '', '1383406', true, 'Video/Public/Movies/2011/CERN-MOVIE-2011-129/CERN-MOVIE-2011-129-0600-kbps-maxH-360-25-fps-...

  12. Vibro-acoustics

    CERN Document Server

    Nilsson, Anders


    This three-volume book gives a thorough and comprehensive presentation of vibration and acoustic theories. Different from traditional textbooks which typically deal with some aspects of either acoustic or vibration problems, it is unique of this book to combine those two correlated subjects together. Moreover, it provides fundamental analysis and mathematical descriptions for several crucial phenomena of Vibro-Acoustics which are quite useful in noise reduction, including how structures are excited, energy flows from an excitation point to a sound radiating surface, and finally how a structure radiates noise to a surrounding fluid. Many measurement results included in the text make the reading interesting and informative. Problems/questions are listed at the end of each chapter and the solutions are provided. This will help the readers to understand the topics of Vibro-Acoustics more deeply. The book should be of interest to anyone interested in sound and vibration, vehicle acoustics, ship acoustics and inter...

  13. Springer handbook of acoustics

    CERN Document Server


    Acoustics, the science of sound, has developed into a broad interdisciplinary field encompassing the academic disciplines of physics, engineering, psychology, speech, audiology, music, architecture, physiology, neuroscience, and electronics. The Springer Handbook of Acoustics is also in his 2nd edition an unparalleled modern handbook reflecting this richly interdisciplinary nature edited by one of the acknowledged masters in the field, Thomas Rossing. Researchers and students benefit from the comprehensive contents. This new edition of the Handbook features over 11 revised and expanded chapters, new illustrations, and 2 new chapters covering microphone arrays  and acoustic emission.  Updated chapters contain the latest research and applications in, e.g. sound propagation in the atmosphere, nonlinear acoustics in fluids, building and concert hall acoustics, signal processing, psychoacoustics, computer music, animal bioacousics, sound intensity, modal acoustics as well as new chapters on microphone arrays an...

  14. Deep Water Ocean Acoustics (United States)


    OASIS, INC. 1 Report No. QSR-14C0172-Ocean Acoustics-043016 Quarterly Progress Report Technical and Financial Deep Water Ocean Acoustics...understanding of the impact of the ocean and seafloor environmental variability on deep- water (long-range) ocean acoustic propagation and to...improve our understanding. During the past few years, the physics effects studied have been three-dimensional propagation on global scales, deep water

  15. Nearfield Acoustical Holography (United States)

    Hayek, Sabih I.

    Nearfield acoustical holography (NAH) is a method by which a set of acoustic pressure measurements at points located on a specific surface (called a hologram) can be used to image sources on vibrating surfaces on the acoustic field in three-dimensional space. NAH data are processed to take advantage of the evanescent wavefield to image sources that are separated less that one-eighth of a wavelength.

  16. Laboratory for Structural Acoustics (United States)

    Federal Laboratory Consortium — FUNCTION: Supports experimental research where acoustic radiation, scattering, and surface vibration measurements of fluid-loaded and non-fluid-loaded structures are...

  17. Handbook of Engineering Acoustics

    CERN Document Server

    Möser, Michael


    This book examines the physical background of engineering acoustics, focusing on empirically obtained engineering experience as well as on measurement techniques and engineering methods for prognostics. Its goal is not only to describe the state of art of engineering acoustics but also to give practical help to engineers in order to solve acoustic problems. It deals with the origin, the transmission and the methods of the abating different kinds of air-borne and structure-borne sounds caused by various mechanisms – from traffic to machinery and flow-induced sound. In addition the modern aspects of room and building acoustics, as well as psychoacoustics and active noise control, are covered.

  18. Acoustic Technology Laboratory (United States)

    Federal Laboratory Consortium — This laboratory contains an electro-magnetic worldwide data collection and field measurement capability in the area of acoustic technology. Outfitted by NASA Langley...

  19. Localized acoustic surface modes (United States)

    Farhat, Mohamed; Chen, Pai-Yen; Bağcı, Hakan


    We introduce the concept of localized acoustic surface modes. We demonstrate that they are induced on a two-dimensional cylindrical rigid surface with subwavelength corrugations under excitation by an incident acoustic plane wave. Our results show that the corrugated rigid surface is acoustically equivalent to a cylindrical scatterer with uniform mass density that can be represented using a Drude-like model. This, indeed, suggests that plasmonic-like acoustic materials can be engineered with potential applications in various areas including sensing, imaging, and cloaking.

  20. Shallow Water Acoustic Laboratory (United States)

    Federal Laboratory Consortium — FUNCTION: Supports experimental research where high-frequency acoustic scattering and surface vibration measurements of fluid-loaded and non-fluid-loaded structures...

  1. Localized Acoustic Surface Modes

    KAUST Repository

    Farhat, Mohamed


    We introduce the concept of localized acoustic surface modes (ASMs). We demonstrate that they are induced on a two-dimensional cylindrical rigid surface with subwavelength corrugations under excitation by an incident acoustic plane wave. Our results show that the corrugated rigid surface is acoustically equivalent to a cylindrical scatterer with uniform mass density that can be represented using a Drude-like model. This, indeed, suggests that plasmonic-like acoustic materials can be engineered with potential applications in various areas including sensing, imaging, and cloaking.

  2. Acoustic Signals and Systems

    DEFF Research Database (Denmark)


    The Handbook of Signal Processing in Acoustics will compile the techniques and applications of signal processing as they are used in the many varied areas of Acoustics. The Handbook will emphasize the interdisciplinary nature of signal processing in acoustics. Each Section of the Handbook...... will present topics on signal processing which are important in a specific area of acoustics. These will be of interest to specialists in these areas because they will be presented from their technical perspective, rather than a generic engineering approach to signal processing. Non-specialists, or specialists...

  3. Electrically Driven Technologies for Radioactive Aerosol Abatement

    Energy Technology Data Exchange (ETDEWEB)

    David W. DePaoli; Ofodike A. Ezekoye; Costas Tsouris; Valmor F. de Almeida


    The purpose of this research project was to develop an improved understanding of how electriexecy driven processes, including electrocoalescence, acoustic agglomeration, and electric filtration, may be employed to efficiently treat problems caused by the formation of aerosols during DOE waste treatment operations. The production of aerosols during treatment and retrieval operations in radioactive waste tanks and during thermal treatment operations such as calcination presents a significant problem of cost, worker exposure, potential for release, and increased waste volume.

  4. CASINDO Programme Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Van der Linden, N.; Smekens, K.; Bole-Rentel, T.; Saidi, R. [Unit ECN Policy Studies, Energy research Centre of the Netherlands ECN, Petten (Netherlands); Wijnker, M. [Eindhoven University of Technology TUE, Eindhoven (Netherlands); Kamphuis, E. [ETC Netherlands, Leusden (Netherlands); Winarno, Oetomo Tri [Institute of Technology, Bandung (Indonesia); Permana, Iman [Technical Education Development Centre, Bandung (Indonesia)


    The overall objective of the CASINDO programme is to establish a self-sustaining and self-developing structure at both the national and regional level to build and strengthen human capacity to enable the provinces of North Sumatra, Yogyakarta, Central Java, West Nusa Tenggara and Papua to formulate sound policies for renewable energy and energy efficiency and to develop and implement sustainable energy projects. CASINDO stands for Capacity development and strenghtening for energy policy formulation adn implementation of sustainable energy projects in Indonesia.

  5. Programmable pulse generator

    CERN Document Server

    Xue Zhi Hua; Duan Xiao Hui


    The author introduces the design of programmable pulse generator that is based on a micro-controller and controlled by RS232 interface of personal computer. The whole system has good stability. The pulse generator can produce TTL pulse and analog pulse. The pulse frequency can be selected by EPLD. The voltage amplitude and pulse width of analog pulse can be adjusted by analog switches and digitally-controlled potentiometers. The software development tools of computer is National Instruments LabView5.1. The front panel of this virtual instrumentation is intuitive and easy-to-use. Parameters can be selected and changed conveniently by knob and slide

  6. Binary mask programmable hologram. (United States)

    Tsang, P W M; Poon, T-C; Zhou, Changhe; Cheung, K W K


    We report, for the first time, the concept and generation of a novel Fresnel hologram called the digital binary mask programmable hologram (BMPH). A BMPH is comprised of a static, high resolution binary grating that is overlaid with a lower resolution binary mask. The reconstructed image of the BMPH can be programmed to approximate a target image (including both intensity and depth information) by configuring the pattern of the binary mask with a simple genetic algorithm (SGA). As the low resolution binary mask can be realized with less stringent display technology, our method enables the development of simple and economical holographic video display.

  7. The ONTARGET trial programme

    DEFF Research Database (Denmark)

    Unger, Thomas; Kintscher, Ulrich; Kappert, Kai;


    The ONTARGET trial programme tested the effects of the angiotensin AT1 receptor blocker (ARB), telmisartan, alone or in combination with the angiotensin converting enzyme (ACE) inhibitor, ramipril, in more than 25.000 patients at high cardiovascular risk including diabetes on a combined endpoint ....... Telmisartan thus proved to be the first and so far the only representative of the ARB class that can be used as an alternative to the "gold standard" ACE-inhibitor, ramipril, in patients at high cardiovascular risk with or without hypertension. © 2009 Bentham Science Publishers Ltd....

  8. Flexible programmable logic module

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, Perry J. (Albuquerque, NM); Hutchinson, Robert L. (Albuquerque, NM); Pierson, Lyndon G. (Albuquerque, NM)


    The circuit module of this invention is a VME board containing a plurality of programmable logic devices (PLDs), a controlled impedance clock tree, and interconnecting buses. The PLDs are arranged to permit systolic processing of a problem by offering wide data buses and a plurality of processing nodes. The board contains a clock reference and clock distribution tree that can drive each of the PLDs with two critically timed clock references. External clock references can be used to drive additional circuit modules all operating from the same synchronous clock reference.

  9. Finnish energy technology programmes 1998

    Energy Technology Data Exchange (ETDEWEB)



    The Finnish Technology Development Centre (Tekes) is responsible for the financing of research and development in the field of energy production technology. A considerable part of the financing goes to technology programmes. Each technology programme involves major Finnish institutions - companies, research institutes, universities and other relevant interests. Many of the energy technology programmes running in 1998 were launched collectively in 1993 and will be completed at the end of 1998. They are complemented by a number of other energy-related technology programmes, each with a timetable of its own. Because energy production technology is horizontal by nature, it is closely connected with research and development in other fields, too, and is an important aspect in several other Tekes technology programmes. For this reason this brochure also presents technology programmes where energy is only one of the aspects considered but which nevertheless contribute considerably to research and development in the energy production sector


    CERN Multimedia

    Human Resources Division


    27 March 2001 from 2.00 p.m. to 5.30 p.m. 28 March 2001 from 2.00 p.m. to 5.30 p.m. 29 March 2001 from 2.00 p.m. to 5.30 p.m. 30 March 2001 from 2.00 p.m. to 4.45 p.m. Auditorium (Main Building) After the success of the preparation seminars held in recent years, it has been decided that the programme should continue. The forthcoming seminar has been prepared in close collaboration with the CERN Pensioners' Association. The programme will be organised over several half-day sessions. Once again this year, a special session will be devoted to the 10th revision of the Swiss state pension scheme, the 'AVS' (Assurance-Vieillesse et Survivants), and the consequences for international civil servants. A talk will be given by Mrs Danièle Siebold, Director of the Caisse Cantonale Genevoise de Compensation, aimed mainly at those residing in or intending to move to Switzerland, or who worked in Switzerland before joining CERN. To enable Mrs Siebold to respond to your concerns as effectively as possible, please ...

  11. Copernicus Earth observation programme (United States)

    Žlebir, Silvo

    European Earth observation program Copernicus is an EU-wide programme that integrates satellite data, in-situ data and modeling to provide user-focused information services to support policymakers, researchers, businesses and citizens. Land monitoring service and Emergency service are fully operational already, Atmosphere monitoring service and Marine environment monitoring service are preoperational and will become fully operational in the following year, while Climate change service and Security service are in an earlier development phase. New series of a number of dedicated satellite missions will be launched in the following years, operated by the European Space Agency and EUMETSAT, starting with Sentinel 1A satellite early this year. Ground based, air-borne and sea-borne in-situ data are provided by different international networks and organizations, EU member states networks etc. European Union is devoting a particular attention to secure a sustainable long-term operational provision of the services. Copernicus is also stated as a European Union’s most important contribution to Global Earth Observation System of Systems (GEOSS). The status and the recent development of the Copernicus programme will be presented, together with its future perspective. As Copernicus services have already demonstrated their usability and effectiveness, some interesting cases of their deployment will be presented. Copernicus free and open data policy, supported by a recently adopted EU legislative act, will also be presented.

  12. The Global Atmosphere Watch Programme: New Challenges and Opportunities (United States)

    Terblanche, D. E.; Tarasova, O. A.


    The Global Atmosphere Watch Programme, one of the tree research Programmes of the World Meteorological Organization (WMO/GAW) is the only existing long-term international global programme that coordinates observations and analysis of atmospheric composition changes. The GAW Programme builds on a partnership of more than 100 countries. Within its 25 years of existence WMO/GAW has matured to the system that provides reliable long-term high quality observations in support of international policy making. WMO/GAW includes globally coordinated observational network, complemented by a comprehensive quality assurance system and capacity development. In spite of the fact that GAW has embraced the IGACO strategy (Integrated Global Atmospheric Chemistry Observations), the programme in its current form still has a strong observational bias. Future development of WMO/GAW requires the further evolution of the programme concept toward "science for services". New challenges call for the changes in the GAW station requirements and data managements, for new approaches to collaboration with the contributing networks and better involvement of the modelling community. The programme structure is evolving to streamline better to user requirements with the move from precipitation chemistry to total deposition and from near-real-time data delivery to applications (modeling) requiring such data delivery. The updated concept of GAW will include more cross-cutting applications. A new category of local station is introduced to help with the verification of some applications including those related to urban areas and the impacts of urban complexes regionally and globally. The evolution of the GAW Programme towards user driven cross-cutting applications provides a new opportunity to the National Meteorological and Hydrological Services in partnership with other science - based institutions to increase their relevance to society.

  13. Programmable fast data acquisition system (United States)

    Montebugnoli, S.; Bianchi, G.; Zoni, L.

    The goal of this work is to investigate the possibility to install on modern radiotelescopes a fast and programmable backend instead of several backends, each dedicated to a single acquisition task. Such an approach could lower the costs and make available a more compact and flexible back end. Exploiting the state-of-the-art of the FPGAs (Field Programmable Gate Arrays) and innovative architectures, a programmable system might be conceived.

  14. Programmable pH buffers (United States)

    Gough, Dara Van; Huber, Dale L.; Bunker, Bruce C.; Roberts, Mark E.


    A programmable pH buffer comprises a copolymer that changes pK.sub.a at a lower critical solution temperature (LCST) in water. The copolymer comprises a thermally programmable polymer that undergoes a hydrophobic-to-hydrophilic phase change at the LCST and an electrolytic polymer that exhibits acid-base properties that are responsive to the phase change. The programmable pH buffer can be used to sequester CO.sub.2 into water.

  15. Acoustic fluidization for earthquakes?


    Sornette, D.; Sornette, A.


    Melosh [1996] has suggested that acoustic fluidization could provide an alternative to theories that are invoked as explanations for why some crustal faults appear to be weak. We show that there is a subtle but profound inconsistency in the theory that unfortunately invalidates the results. We propose possible remedies but must acknowledge that the relevance of acoustic fluidization remains an open question.

  16. Cochlear bionic acoustic metamaterials (United States)

    Ma, Fuyin; Wu, Jiu Hui; Huang, Meng; Fu, Gang; Bai, Changan


    A design of bionic acoustic metamaterial and acoustic functional devices was proposed by employing the mammalian cochlear as a prototype. First, combined with the experimental data in previous literatures, it is pointed out that the cochlear hair cells and stereocilia cluster are a kind of natural biological acoustic metamaterials with the negative stiffness characteristics. Then, to design the acoustic functional devices conveniently in engineering application, a simplified parametric helical structure was proposed to replace actual irregular cochlea for bionic design, and based on the computational results of such a bionic parametric helical structure, it is suggested that the overall cochlear is a local resonant system with the negative dynamic effective mass characteristics. There are many potential applications in the bandboard energy recovery device, cochlear implant, and acoustic black hole.

  17. Computational Ocean Acoustics

    CERN Document Server

    Jensen, Finn B; Porter, Michael B; Schmidt, Henrik


    Since the mid-1970s, the computer has played an increasingly pivotal role in the field of ocean acoustics. Faster and less expensive than actual ocean experiments, and capable of accommodating the full complexity of the acoustic problem, numerical models are now standard research tools in ocean laboratories. The progress made in computational ocean acoustics over the last thirty years is summed up in this authoritative and innovatively illustrated new text. Written by some of the field's pioneers, all Fellows of the Acoustical Society of America, Computational Ocean Acoustics presents the latest numerical techniques for solving the wave equation in heterogeneous fluid–solid media. The authors discuss various computational schemes in detail, emphasizing the importance of theoretical foundations that lead directly to numerical implementations for real ocean environments. To further clarify the presentation, the fundamental propagation features of the techniques are illustrated in color. Computational Ocean A...

  18. Ocean acoustic reverberation tomography. (United States)

    Dunn, Robert A


    Seismic wide-angle imaging using ship-towed acoustic sources and networks of ocean bottom seismographs is a common technique for exploring earth structure beneath the oceans. In these studies, the recorded data are dominated by acoustic waves propagating as reverberations in the water column. For surveys with a small receiver spacing (e.g., ocean acoustic reverberation tomography, is developed that uses the travel times of direct and reflected waves to image ocean acoustic structure. Reverberation tomography offers an alternative approach for determining the structure of the oceans and advancing the understanding of ocean heat content and mixing processes. The technique has the potential for revealing small-scale ocean thermal structure over the entire vertical height of the water column and along long survey profiles or across three-dimensional volumes of the ocean. For realistic experimental geometries and data noise levels, the method can produce images of ocean sound speed on a smaller scale than traditional acoustic tomography.

  19. Laser Imaging of Airborne Acoustic Emission by Nonlinear Defects (United States)

    Solodov, Igor; Döring, Daniel; Busse, Gerd


    Strongly nonlinear vibrations of near-surface fractured defects driven by an elastic wave radiate acoustic energy into adjacent air in a wide frequency range. The variations of pressure in the emitted airborne waves change the refractive index of air thus providing an acoustooptic interaction with a collimated laser beam. Such an air-coupled vibrometry (ACV) is proposed for detecting and imaging of acoustic radiation of nonlinear spectral components by cracked defects. The photoelastic relation in air is used to derive induced phase modulation of laser light in the heterodyne interferometer setup. The sensitivity of the scanning ACV to different spatial components of the acoustic radiation is analyzed. The animated airborne emission patterns are visualized for the higher harmonic and frequency mixing fields radiated by planar defects. The results confirm a high localization of the nonlinear acoustic emission around the defects and complicated directivity patterns appreciably different from those observed for fundamental frequencies.

  20. Photovoltaic programme - edition 2003

    Energy Technology Data Exchange (ETDEWEB)



    This publication issued by the Swiss Federal Office of Energy's Photovoltaics (PV) Programme presents an overview (in English) of activities and projects in the photovoltaics research and pilot and demonstration area in Switzerland. Progress in the area of future solar cell technologies, modules and building integration, system technologies, planning and operating aids is summarised. Also, PV for applications in developing countries, thermo-photovoltaics and international co-operation are commented on. In the area of pilot and demonstration projects, component development, PV integration in sloping roofs, on flat roofs and noise barriers as well as further PV plant are looked at. Also, measurement campaigns, studies, statistics and further PV-related topics are summarised. This volume also presents the abstracts of reports made by the project managers of 73 research and pilot and demonstration projects in these areas for 2002.

  1. Programmable ferroelectric tunnel memristor

    Directory of Open Access Journals (Sweden)

    Andy eQuindeau


    Full Text Available We report an analogously programmable memristor based on genuine electronic resistive switching combining ferroelectric switching and electron tunneling. The tunnel current through an 8 unit cell thick epitaxial Pb(Zr[0.2]Ti[0.8]O[3] film sandwiched between La[0.7]Sr[0.3]MnO[3] and cobalt electrodes obeys the Kolmogorov-Avrami-Ishibashi model for bidimensional growth with a characteristic switching time in the order of 10^-7 seconds. The analytical description of switching kinetics allows us to develop a characteristic transfer function that has only one parameter viz. the characteristic switching time and fully predicts the resistive states of this type of memristor.

  2. Flat acoustic lens by acoustic grating with curled slits

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Pai; Xiao, Bingmu; Wu, Ying, E-mail:


    We design a flat sub-wavelength lens that can focus acoustic wave. We analytically study the transmission through an acoustic grating with curled slits, which can serve as a material with tunable impedance and refractive index for acoustic waves. The effective parameters rely on the geometry of the slits and are independent of frequency. A flat acoustic focusing lens by such acoustic grating with gradient effective refractive index is designed. The focusing effect is clearly observed in simulations and well predicted by the theory. We demonstrate that despite the large impedance mismatch between the acoustic lens and the matrix, the intensity at the focal point is still high due to Fabry–Perot resonance. - Highlights: • Expression of transmission coefficient of an acoustic grating with curled slits. • Non-dispersive and tunable effective medium parameters for the acoustic grating. • A flat acoustic focusing lens with gradient index by using the acoustic grating.

  3. Advanced Applications for Underwater Acoustic Modeling

    Directory of Open Access Journals (Sweden)

    Paul C. Etter


    Full Text Available Changes in the ocean soundscape have been driven by anthropogenic activity (e.g., naval-sonar systems, seismic-exploration activity, maritime shipping and windfarm development and by natural factors (e.g., climate change and ocean acidification. New regulatory initiatives have placed additional restrictions on uses of sound in the ocean: mitigation of marine-mammal endangerment is now an integral consideration in acoustic-system design and operation. Modeling tools traditionally used in underwater acoustics have undergone a necessary transformation to respond to the rapidly changing requirements imposed by this new soundscape. Advanced modeling techniques now include forward and inverse applications, integrated-modeling approaches, nonintrusive measurements, and novel processing methods. A 32-year baseline inventory of modeling techniques has been updated to reflect these new developments including the basic mathematics and references to the key literature. Charts have been provided to guide soundscape practitioners to the most efficient modeling techniques for any given application.

  4. Predicting Acoustics in Class Rooms

    DEFF Research Database (Denmark)

    Christensen, Claus Lynge; Rindel, Jens Holger


    Typical class rooms have fairly simple geometries, even so room acoustics in this type of room is difficult to predict using today's room acoustic computer modeling software. The reasons why acoustics of class rooms are harder to predict than acoustics of complicated concert halls might...

  5. Underwater Applications of Acoustical Holography

    Directory of Open Access Journals (Sweden)

    P. C. Mehta


    Full Text Available The paper describes the basic technique of acoustical holography. Requirements for recording the acoustical hologram are discussed with its ability for underwater imaging in view. Some practical systems for short-range and medium-range imaging are described. The advantages of acoustical holography over optical imaging, acoustical imaging and sonars are outlined.

  6. Acoustic mapping velocimetry (United States)

    Muste, M.; Baranya, S.; Tsubaki, R.; Kim, D.; Ho, H.; Tsai, H.; Law, D.


    Knowledge of sediment dynamics in rivers is of great importance for various practical purposes. Despite its high relevance in riverine environment processes, the monitoring of sediment rates remains a major and challenging task for both suspended and bed load estimation. While the measurement of suspended load is currently an active area of testing with nonintrusive technologies (optical and acoustic), bed load measurement does not mark a similar progress. This paper describes an innovative combination of measurement techniques and analysis protocols that establishes the proof-of-concept for a promising technique, labeled herein Acoustic Mapping Velocimetry (AMV). The technique estimates bed load rates in rivers developing bed forms using a nonintrusive measurements approach. The raw information for AMV is collected with acoustic multibeam technology that in turn provides maps of the bathymetry over longitudinal swaths. As long as the acoustic maps can be acquired relatively quickly and the repetition rate for the mapping is commensurate with the movement of the bed forms, successive acoustic maps capture the progression of the bed form movement. Two-dimensional velocity maps associated with the bed form migration are obtained by implementing algorithms typically used in particle image velocimetry to acoustic maps converted in gray-level images. Furthermore, use of the obtained acoustic and velocity maps in conjunction with analytical formulations (e.g., Exner equation) enables estimation of multidirectional bed load rates over the whole imaged area. This paper presents a validation study of the AMV technique using a set of laboratory experiments.

  7. Programmable architecture for quantum computing

    NARCIS (Netherlands)

    Chen, J.; Wang, L.; Charbon, E.; Wang, B.


    A programmable architecture called “quantum FPGA (field-programmable gate array)” (QFPGA) is presented for quantum computing, which is a hybrid model combining the advantages of the qubus system and the measurement-based quantum computation. There are two kinds of buses in QFPGA, the local bus and t

  8. SWOV programme 2003-2006.

    NARCIS (Netherlands)


    SWOV uses a four-year programme to structure its activities over a longer period of time. The current four-year programme, for 2003-2006, includes proposals for so-called planning office activities, anticipatory research, knowledge management, and knowledge dissemination. The research activities are

  9. An automatic bibliography indexing programme

    Directory of Open Access Journals (Sweden)

    J. W. Morris


    Full Text Available A relatively simple FORTRAN IV programme, designed for a small computer, for author and key-word indexes to bibliographic records is described, and examples of output are given. It is com­pared with some other systems. Suggested improvements to the programme are given.

  10. Japan's Eco-School Programme (United States)

    Mori, Masayuki


    Since 1997, several ministries in Japan have collaborated on an eco-school programme, which applies to both newly constructed and renovated school buildings, in an effort to make its schools more environmentally friendly. The programme equips school buildings with ecological features such as photovoltaic cells, solar thermal collectors, other new…

  11. 'Motor challenge' pilot programme; Motor Challenge Pilotprogramm. Schweizer Teilnahme im SAVE-Programm: pilot actions for motor systems industrial energy use challenge

    Energy Technology Data Exchange (ETDEWEB)

    Nipkow, J.


    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of a pilot project associated with the Motor Challenge Programme (MCP) initiated by the European Commission (Transport and Energy Committee). The programme is briefly described, which aims to improve the efficiency of electrical motors used in industrial compressed-air, pump and ventilator systems as well as in comprehensive motor driven systems. Switzerland's participation in this pilot project is examined, which was concluded after a period of two years when the Motor Challenge Programme itself was launched in February 2003. The mechanisms of the programme are described, whereby companies may become involved in the programme either as partners (users of drive systems) or as endorsers (suppliers, planners, etc., of such systems). Experience gained with two companies in Switzerland - a food processing group and a major chemical pulp producer - who participated in the programme is presented. Efficiency potentials of around 3 GWh/a were identified; these represent a high proportion of the estimated total of 18 GWh/a in the overall programme. A follow-up project is proposed that is to provide detailed information and initiate further efficiency projects in order to encourage other companies to participate in the MCP programme.

  12. Acoustic Igniter Project (United States)

    National Aeronautics and Space Administration — An acoustic igniter eliminates the need to use electrical energy to drive spark systems to initiate combustion in liquid-propellant rockets. It does not involve the...

  13. Acoustic imaging system (United States)

    Kendall, J. M., Jr.


    Tool detects noise sources by scanning sound "scene" and displaying relative location of noise-producing elements in area. System consists of ellipsoidal acoustic mirror and microphone and a display device.

  14. Acoustic imaging system (United States)

    Smith, Richard W.


    An acoustic imaging system for displaying an object viewed by a moving array of transducers as the array is pivoted about a fixed point within a given plane. A plurality of transducers are fixedly positioned and equally spaced within a laterally extending array and operatively directed to transmit and receive acoustic signals along substantially parallel transmission paths. The transducers are sequentially activated along the array to transmit and receive acoustic signals according to a preestablished sequence. Means are provided for generating output voltages for each reception of an acoustic signal, corresponding to the coordinate position of the object viewed as the array is pivoted. Receptions from each of the transducers are presented on the same display at coordinates corresponding to the actual position of the object viewed to form a plane view of the object scanned.

  15. An acoustic invisible gateway

    CERN Document Server

    Zhu, Yi-Fan; Liang, Bin; Kan, Wei-Wei; Yang, Jun; Cheng, Jian-Chun


    The recently-emerged concept of "invisible gateway" with the extraordinary capability to block the waves but allow the passage of other entities has attracted great attentions due to the general interests in illusion devices. However, the possibility to realize such a fascinating phenomenon for acoustic waves has not yet been explored, which should be of paramount significance for acoustical applications but would necessarily involve experimental difficulty. Here we design and experimentally demonstrate an acoustic invisible gateway (AIG) capable of concealing a channel under the detection of sound. Instead of "restoring" a whole block of background medium by using transformation acoustics that inevitably requires complementary or restoring media with extreme parameters, we propose an inherently distinct methodology that only aims at engineering the surface impedance at the "gate" to mimic a rigid "wall" and can be conveniently implemented by decorating meta-structures behind the channel. Such a simple yet ef...

  16. Acoustics Noise Test Cell (United States)

    Federal Laboratory Consortium — The Acoustic Noise Test Cell at the NASA/Caltech Jet Propulsion Laboratory (JPL) is located adjacent to the large vibration system; both are located in a class 10K...

  17. Thermal Acoustic Fatigue Apparatus (United States)

    Federal Laboratory Consortium — The Thermal Acoustic Fatigue Apparatus (TAFA) is a progressive wave tube test facility that is used to test structures for dynamic response and sonic fatigue due to...

  18. Autonomous Acoustic Receiver System (United States)

    Federal Laboratory Consortium — FUNCTION: Collects underwater acoustic data and oceanographic data. Data are recorded onboard an ocean buoy and can be telemetered to a remote ship or shore station...

  19. Principles of musical acoustics

    CERN Document Server

    Hartmann, William M


    Principles of Musical Acoustics focuses on the basic principles in the science and technology of music. Musical examples and specific musical instruments demonstrate the principles. The book begins with a study of vibrations and waves, in that order. These topics constitute the basic physical properties of sound, one of two pillars supporting the science of musical acoustics. The second pillar is the human element, the physiological and psychological aspects of acoustical science. The perceptual topics include loudness, pitch, tone color, and localization of sound. With these two pillars in place, it is possible to go in a variety of directions. The book treats in turn, the topics of room acoustics, audio both analog and digital, broadcasting, and speech. It ends with chapters on the traditional musical instruments, organized by family. The mathematical level of this book assumes that the reader is familiar with elementary algebra. Trigonometric functions, logarithms and powers also appear in the book, but co...

  20. Symptoms of Acoustic Neuroma (United States)

    ... Programs & Services Search Connect with us! Symptoms of Acoustic Neuroma Each heading slides to reveal more information. Early Symptoms Early Symptoms Early symptoms are easily overlooked, thus making diagnosis ...

  1. Good on paper: the gap between programme theory and real-world context in Pakistan's Community Midwife programme (United States)

    Mumtaz, Z; Levay, A; Bhatti, A; Salway, S


    Objective To understand why skilled birth attendance—an acknowledged strategy for reducing maternal deaths—has been effective in some settings but is failing in Pakistan and to demonstrate the value of a theory-driven approach to evaluating implementation of maternal healthcare interventions. Design Implementation research was conducted using an institutional ethnographic approach. Setting and population National programme and local community levels in Pakistan. Methods Observations, focus group discussions, and in-depth interviews were conducted with 38 Community Midwives (CMWs), 20 policymakers, 45 healthcare providers and 136 community members. A critical policy document review was conducted. National and local level data were brought together. Main outcomes Alignment of programme theory with real-world practice. Results Data revealed gaps between programme theory, assumptions and reality on the ground. The design of the programme failed to take into account: (1) the incongruity between the role of a midwife and dominant class and gendered norms that devalue such a role; (2) market and consumer behaviour that prevented CMWs from establishing private practices; (3) the complexity of public–private sector cooperation. Uniform deployment policies failed to consider existing provider density and geography. Conclusions Greater attention to programme theory and the ‘real-world’ setting during design of maternal health strategies is needed to achieve consistent results in different contexts. PMID:25315837

  2. A theory-driven evaluation of a wellness initiative

    Directory of Open Access Journals (Sweden)

    Carren Field


    Full Text Available Orientation: By reporting on an evaluation of a wellness initiative, this article brings together an element of organisational development (employee wellness with an approach to programme evaluation (programme theory-driven evaluation. Research purpose: Two questions were addressed: ‘What is the causal logic of the wellness initiative?’ and ‘Is this a plausible programme theory according to social science research and literature?’Motivation for the study: A study that could demonstrate the usefulness of the theory-driven evaluation approach, especially in the local human resource (HR domain, was considered to be valuable. In addition, this evaluation provided a careful consideration of how plausible it is for such interventions to achieve what they set out to do.Research design, approach and method: The evaluation relied mainly on qualitative methods (the examination of secondary data and interviewing to extract programme theory, and on literature to assess plausibility.Main findings: The study had two main outcomes: the finalisation of a model of how the programme is supposed to work according to programme staff, and the conclusion that the model is plausible, provided it is implemented at full strength.Practical/managerial implications: Programme staff are advised to pay particular attention to implementation fidelity, especially to employee participation and involvement in the programme’s activities. A number of strategies are recommended to strengthen the effect of the model.Contribution/value-add: This evaluation showed the importance of conducting a theory- driven evaluation, not only in order to understand the programme and its context, but also to provide a basis for an implementation and outcome evaluation.

  3. Anal acoustic reflectometry

    DEFF Research Database (Denmark)

    Mitchell, Peter J; Klarskov, Niels; Telford, Karen J;


    Anal acoustic reflectometry is a new technique of assessing anal sphincter function. Five new variables reflecting anal canal function are measured: the opening and closing pressure, the opening and closing elastance, and hysteresis.......Anal acoustic reflectometry is a new technique of assessing anal sphincter function. Five new variables reflecting anal canal function are measured: the opening and closing pressure, the opening and closing elastance, and hysteresis....

  4. Summer Student Lecture Programme

    CERN Multimedia


    Main Auditorium, bldg. 500 More Information DATE TIME LECTURER TITLE Wednesday 7 July 09:15 - 10:00 L. Fayard, O. Ullaland, D. Heagerty (CERN) Programme Presentation Workshops presentation Information on Computing Rules 10:15 - 11:00 R. Aymar (CERN) Introduction to CERN (1/2) 11:15 - 12:00 J. Engelen (CERN) Introduction to CERN (2/2) 15:00 - 16:30 H. Menzel (CERN) An Introduction to Radiation Protection DATE TIME LECTURER TITLE Thursday 8 july 09:15 - 10:00 L. Di Lella (CERN) Introduction to Particle Physics (1/4) 10:15 - 11:00 L. Di Lella (CERN) Introduction to Particle Physics (2/4) 11:15 - 12:00 P. Chomaz (GANIL / CERN) Fundamental questions in modern nuclear physics: The challenge of exotic nuclei (1/2) DATE TIME LECTURER TITLE Friday 9 July 09:15 - 10:00 L. Di Lella (CERN) Introduction to Particle Physics (3/4) 10:15 - 11:00 P. Chomaz (GANIL / CERN) Fundamental questions in modern nuclear physics: The challenge of exotic nuclei (2/2) 11:15 - 12:00 P....


    CERN Multimedia

    Françoise Benz


    SUMMER STUDENT LECTURE PROGRAMME Main Auditorium, bldg. 500   DATE TIME LECTURER TITLE Monday 29 July 09:15 - 10:00 R. RATTAZZI Beyond the Standard Model (3/3) 10:15 - 11:00 P. WELLS Experimental test of the SM - LEP (3/3) 11:15 - 12:00 P. WELLS Discussion Session 14:00 - 16:00 R. ASSMANN The CLIC Concept for a Future Particle Collider at the Energy Frontier Tuesday 30 July 09:15 - 10:00 F. ANTINORI Heavy Ions (1/2) 10:15 - 12:00 F. DYDAK Neutrino Physics (1&2/4) Wednesday 31 July  09:15 - 10:00 F. ANTINORI Heavy Ions (2/2) 10:15 - 11:00 F. DYDAK Neutrino Physics (3/4) 11:15 - 12:00 F. DYDAK / F. ANTINORI Discussion Session Thursday 1 August 09:15 - 10:00 T. NAKADA CP Violation (1/4) 10:15 - 11:00 F. DYDAK Neutrino Physics (4/4) 11:15 - 12:00 F. BEDESCHI Experimental test of the SM Tevatron (1/2) Friday 2 August 09:15 - 10:00 T. NAKADA CP Violation (2/4) 10:15 ? 11:00 F. BEDESCHI Experimental test of the SM Tevatron (2/2) 11:15 ? 12:00 F. BEDESCHI / T. NAKADA Di...

  6. FPGAs for software programmers

    CERN Document Server

    Hannig, Frank; Ziener, Daniel


    This book makes powerful Field Programmable Gate Array (FPGA) and reconfigurable technology accessible to software engineers by covering different state-of-the-art high-level synthesis approaches (e.g., OpenCL and several C-to-gates compilers). It introduces FPGA technology, its programming model, and how various applications can be implemented on FPGAs without going through low-level hardware design phases. Readers will get a realistic sense for problems that are suited for FPGAs and how to implement them from a software designer’s point of view. The authors demonstrate that FPGAs and their programming model reflect the needs of stream processing problems much better than traditional CPU or GPU architectures, making them well-suited for a wide variety of systems, from embedded systems performing sensor processing to large setups for Big Data number crunching. This book serves as an invaluable tool for software designers and FPGA design engineers who are interested in high design productivity through behavi...

  7. Summer Student Programme

    CERN Multimedia


    Date Time Title Speaker 05/07/2006 09:15 - 10:00 Presentation of the Summer Student Programme F. CERUTTI Information on Computing Rules D. HEAGERTY Workshops presentation O. ULLALAND 10:15 - 11:00 Introduction to CERN J. ENGELEN 11:15 Film on CERN 11:00 Introduction to Particle Physics F. CLOSE 11:15 - 12:00 Accelerators (1/5) S. GILARDONI / E. METRAL 12:00 Discussion Session 7/07/2006 09:15 - 11:00 Introduction to Particle Physics F. CLOSE 11:15 - 12:00 Accelerators (2/5) S. GILARDONI / E. METRAL 12:00 Discussion Session 09:15 - 10:00 Accelerators (3/5) S. GILARDONI / E. METRAL 10:15 - 12:00 Detectors (1-2/5) O. ULLALAND 12:00 Discussion Session 11/07/2006 09:15 - 10:00 Accelerators (4/5) S. GILARDONI / E. METRAL 10:15 - 11:00 Detectors (3/5) O. ULLALAND 11:15 - 12:00 Introduction to Nuclear Physics (1/4) P. CHOMAZ P. CHOMAZ 10:15 - 11:00 Accelerators (5/5) S. GILARDONI / E. METRAL 11:15 - 12:00 Detectors (4/5) O. ULLALAND 12:00 Discus...

  8. Management and Communication programme

    CERN Multimedia

    Nathalie Dumeaux


    We are pleased to announce the launch of three new courses in the Management and Communication programme: 1.     Managing Time (Open to all Staff Members) The objectives are: To enhance your personal effectiveness through better organisation skills To acquire ways of making the most of your time through improved work habits To reduce stress For the description of this course, please see: 2.     Service Orientation (Open to all Staff Members working in a service-related function) The objectives are: To understand the key elements in an effective client/service provider relationship To develop a client focused approach to providing services For the description of this course, please see: 3.   Introduction to Leadership (Open to Staff in Career Paths E & above, including newly appointed supervisors and Sect...

  9. Management and Communication programme

    CERN Multimedia

    Nathalie Dumeaux


    We are pleased to announce the launch of three new courses in the Management and Communication programme: 1.     Managing Time (Open to all Staff Members) The objectives are: To enhance your personal effectiveness through better organisation skills To acquire ways of making the most of your time through improved work habits To reduce stress For the description of this course, please see: 2.     Service Orientation (Open to all Staff Members working in a service-related function) The objectives are: To understand the key elements in an effective client/service provider relationship To develop a client focused approach to providing services For the description of this course, please see: 3.   Introduction to Leadership (Open to Staff in Career Paths E & above, including newly appointed supervisors and Secti...

  10. The BGAN extension programme (United States)

    Rivera, Juan J.; Trachtman, Eyal; Richharia, Madhavendra


    Mobile satellite telecommunications systems have undergone an enormous evolution in the last decades, with the interest in having advanced telecommunications services available on demand, anywhere and at any time, leading to incredible advances. The demand for braodband data is therefore rapidly gathering pace, but current solutions are finding it increasingly difficult to combine large bandwidth with ubiquitous coverage, reliability and portability. The BGAN (Broadband Global Area Network) system, designed to operate with the Inmarsat-4 satellites, provides breakthrough services that meet all of these requirements. It will enable broadband connection on the move, delivering all the key tools of the modern office. Recognising the great impact that Inmarsat's BGAN system will have on the European satellite communications industry, and the benefits that it will bring to a wide range of European industries, in 2003 ESA initiated the "BGAN Extension" project. Its primary goals are to provide the full range of BGAN services to truly mobile platforms, operating in aeronautical, vehicular and maritime environments, and to introduce a multicast service capability. The project is supported by the ARTES Programme which establishes a collaboration agreement between ESA, Inmarsat and a group of key industrial and academic institutions which includes EMS, Logica, Nera and the University of Surrey (UK).

  11. ALICE pp physics programme

    CERN Document Server

    Kraus, Ingrid


    The physics programme of the ALICE experiment at CERN-LHC comprises besides studies of high-energy heavy-ion collisions measurements of proton-proton interactions at unprecedented energies, too. This paper focuses on the global event characterisation in terms of the multiplicity distribution of charged hadrons and mean transverse momentum. These bulk observables become accessible because the detector features excellent track reconstruction, especially at low transverse momenta. The measurement of strange hadrons is of particular interest since the strange-particle phase-space was found to be suppressed beyond canonical reduction at lower center-of-mass energies and the production mechanism of soft particles is not yet fully understood. Here we benefit in particular from particle identification down to very low transverse momentum, i.e. 100 - 300 MeV/c, giving access to spectra and integrated yields of identified hadrons. Equipped with these features, ALICE will play a complementary role w.r.t. other LHC exper...

  12. Photovoltaic programme, edition 2004

    Energy Technology Data Exchange (ETDEWEB)



    This comprehensive publication issued by the Swiss Federal Office of Energy's Photovoltaics (PV) Programme presents an overview (in English) of activities and projects in the photovoltaics research and pilot and demonstration areas in Switzerland for the year 2003. Progress in future solar cell technologies as well as in the area of modules, building integration and system technologies is summarised. Also, national and international co-operation and multi-national pilot and demonstration projects are commented on. Associated projects such as eco-balances for PV systems, forecasting and modelling tools as well as system monitoring tools are discussed. In the area of pilot and demonstration projects, component development, PV integration in sloping roofs, on flat roofs and on facades as well as further PV plant are looked at. Also, measurement campaigns, studies, statistics and other PV-related topics are summarised. This volume presents a list of 92 projects in the PV area including the appropriate Internet links and is completed with a collection of project abstracts.


    CERN Multimedia

    Françoise Benz


    Main Auditorium, bldg. 500   DATE TIME LECTURER TITLE Wednesday 3 July 09:15 - 10:00 L. FAYARD, O. ULLALAND Presentation of the Summer Student Programm 10:15 - 12:00 L. MAIANI Introduction to CERN (1&2/2) 14:00 - 15:00 G. Stevenson Radiation Protection (Council Chamber, bldg.503) Thursday 4 July 09:15 - 11:00 F. CLOSE Introduction to Particle Physics for non Physics Students (1&2/4) 11:15 - 12:00 C. JORAM Particle Detectors (1/5) Friday 5 July 09:15 - 11:00 F. CLOSE Introduction to Particle Physics for non Physics Students (3&4/4) 11:15 - 12:00 Discussion Session Monday 8 July 09:15 - 10:00 R. KLEISS Fundamental Concepts of Particle Physics (1/6) 10:15 - 11:00 C. JORAM Particle Detectors (2/5) 11:15 - 12:00 M. FRANKLIN Classic Experiments (1/3) 14:00 - 15:00 M. LINDROOS Isolde 15:30 - 16:30 M. LINDROOS Visit of the Experiment Tuesday 9 july 09:15 - 10:00 R. KLEISS Fundamental Concepts of Particle Physics (2/6) 10:15 - 11:00 C. JORAM Part...

  14. Experimental programs; Programmes experimentaux

    Energy Technology Data Exchange (ETDEWEB)



    The aim of this Workshop is to establish the status of the experiments for transmutation demonstration and assessment, especially for innovative options and accelerator driven systems (ADS), to establish the results expected to be available for 2006 and to indicate the needs, and to exchange information on experiments. Only one communication is available and concerns the PROFIL irradiation experiments performed with the Phenix reactor. In these experiments, isotopes are separately set in a fuel needle which is placed in a fuel assembly close to the core centre. Samples are analyzed after irradiation in order to determine their variation of composition. These experiments supply precious information about basic nuclear data (capture, fission, n,2n and branching factors) with limited uncertainties. (J.S.)

  15. Acoustic vector sensor signal processing

    Institute of Scientific and Technical Information of China (English)

    SUN Guiqing; LI Qihu; ZHANG Bin


    Acoustic vector sensor simultaneously, colocately and directly measures orthogonal components of particle velocity as well as pressure at single point in acoustic field so that is possible to improve performance of traditional underwater acoustic measurement devices or detection systems and extends new ideas for solving practical underwater acoustic engineering problems. Although acoustic vector sensor history of appearing in underwater acoustic area is no long, but with huge and potential military demands, acoustic vector sensor has strong development trend in last decade, it is evolving into a one of important underwater acoustic technology. Under this background, we try to review recent progress in study on acoustic vector sensor signal processing, such as signal detection, DOA estimation, beamforming, and so on.

  16. Dynamics of coupled light waves and electron-acoustic waves. (United States)

    Shukla, P K; Stenflo, L; Hellberg, M


    The nonlinear interaction between coherent light waves and electron-acoustic waves in a two-electron plasma is considered. The interaction is governed by a pair of equations comprising a Schrödinger-like equation for the light wave envelope and a driven (by the light pressure) electron-acoustic wave equation. The newly derived nonlinear equations are used to study the formation and dynamics of envelope light wave solitons and light wave collapse. The implications of our investigation to space and laser-produced plasmas are pointed out.

  17. CERN openlab summer student programme

    CERN Multimedia


    CERN openlab is currently taking applications for its summer student programme. The closing date for applications is 31 March 2013.   The openlab summer student programme is open for applications from bachelor, master and PhD students in computer science and physics. Successful applicants will spend 9 weeks at CERN, during the period from June to September 2013, working with some of the latest hardware and software technologies. The programme is more than just a summer at CERN: it can lead to follow-on projects at the home institute and may even inspire students to become entrepreneurs in cutting-edge computing technologies. A series of lectures will be given by experts in various domains of CERN-related high-throughput computing. Study tours of external companies and universities as well as of CERN facilities are also part of the programme. Please visit the CERN openlab website for more information.

  18. CERN openlab Summer Student Programme

    CERN Multimedia


    CERN openlab is currently taking applications for its summer student programme. The closing date for applications is 30 March 2012.   The openlab Summer Student Programme is open for applications from bachelor, master and PhD students in computer science and physics. Successful applicants will spend 8 weeks at CERN, during the period June to September 2012, to work with some of the latest hardware and software technologies. The programme is more than just a summer at CERN: it can lead to follow-on projects at the home institute and may even inspire the students to become entrepreneurs in cutting-edge computing technologies. A series of lectures will be given by experts in various domains of CERN related high-throughput computing. Study tours to external companies and universities as well as to CERN facilities are also part of the programme. Please visit for more information.

  19. Acoustic comfort in eating establishments

    DEFF Research Database (Denmark)

    Svensson, David; Jeong, Cheol-Ho; Brunskog, Jonas


    The subjective concept of acoustic comfort in eating establishments has been investigated in this study. The goal was to develop a predictive model for the acoustic comfort, by means of simple objective parameters, while also examining which other subjective acoustic parameters could help explain...... the feeling of acoustic comfort. Through several layers of anal ysis, acoustic comfort was found to be rather complex, and could not be explained entirely by common subjective parameters such as annoyance, intelligibility or privacy. A predictive model for the mean acoustic comfort for an eating establishment...

  20. Interactions in an acoustic world

    CERN Document Server

    Simaciu, Ion; Borsos, Zoltan; Bradac, Mariana


    The present paper aims to complete an earlier paper where the acoustic world was introduced. This is accomplished by analyzing the interactions which occur between the inhomogeneities of the acoustic medium, which are induced by the acoustic vibrations traveling in the medium. When a wave packet travels in a medium, the medium becomes inhomogeneous. The spherical wave packet behaves like an acoustic spherical lens for the acoustic plane waves. According to the principle of causality, there is an interaction between the wave and plane wave packet. In specific conditions the wave packet behaves as an acoustic black hole.

  1. Field Evaluation of Programmable Thermostats

    Energy Technology Data Exchange (ETDEWEB)

    Sachs, O. [Fraunhofer Center for Sustainable Energy Systems (CSE), Cambridge, MA (United States); Tiefenbeck, V. [Fraunhofer Center for Sustainable Energy Systems (CSE), Cambridge, MA (United States); Duvier, C. [Fraunhofer Center for Sustainable Energy Systems (CSE), Cambridge, MA (United States); Qin, A. [Fraunhofer Center for Sustainable Energy Systems (CSE), Cambridge, MA (United States); Cheney, K. [Fraunhofer Center for Sustainable Energy Systems (CSE), Cambridge, MA (United States); Akers, C. [Fraunhofer Center for Sustainable Energy Systems (CSE), Cambridge, MA (United States); Roth, K. [Fraunhofer Center for Sustainable Energy Systems (CSE), Cambridge, MA (United States)


    Prior research suggests that poor programmable thermostats usability may prevent their effective use to save energy. The Fraunhofer team hypothesized that home occupants with high-usability thermostats would be more likely to use them to save energy than people with a basic thermostats. In this report, the team discusses results of a project in which the team monitored and compared programmable thermostats with basic thermostats in an affordable housing apartment complex.

  2. Norwegian mastitis control programme

    Directory of Open Access Journals (Sweden)

    Østerås O


    changes in attitude and breeding, eradicating bovine virus diarrhoea virus (BVDV and a better implementation of mastitis prevention programmes.

  3. Assessing the Financial Viability of Academic Programmes (United States)

    Swift, Lynette


    This paper reviews and examines approaches to determining the financial viability of academic programmes as a critical component of assessing a programme's overall sustainability. Key to assessing the financial viability of a programme is understanding the teaching activities required to deliver the programme and the cost of those activities. A…

  4. A Century of Acoustic Metrology

    DEFF Research Database (Denmark)

    Rasmussen, Knud


    The development in acoustic measurement technique over the last century is reviewed with special emphasis on the metrological aspect.......The development in acoustic measurement technique over the last century is reviewed with special emphasis on the metrological aspect....

  5. Advanced Active Acoustics Lab (AAAL) (United States)

    Federal Laboratory Consortium — The Advanced Active Acoustics Lab (AAAL) is a state-of-the-art Undersea Warfare (USW) acoustic data analysis facility capable of both active and passive underwater...

  6. Acoustic detection of pneumothorax (United States)

    Mansy, Hansen A.; Royston, Thomas J.; Balk, Robert A.; Sandler, Richard H.


    This study aims at investigating the feasibility of using low-frequency (pneumothorax detection were tested in dogs. In the first approach, broadband acoustic signals were introduced into the trachea during end-expiration and transmitted waves were measured at the chest surface. Pneumothorax was found to consistently decrease pulmonary acoustic transmission in the 200-1200-Hz frequency band, while less change was observed at lower frequencies (ppneumothorax states (pPneumothorax was found to be associated with a preferential reduction of sound amplitude in the 200- to 700-Hz range, and a decrease of sound amplitude variation (in the 300 to 600-Hz band) during the respiration cycle (pPneumothorax changed the frequency and decay rate of percussive sounds. These results imply that certain medical conditions may be reliably detected using appropriate acoustic measurements and analysis. [Work supported by NIH/NHLBI #R44HL61108.

  7. Practical acoustic emission testing

    CERN Document Server


    This book is intended for non-destructive testing (NDT) technicians who want to learn practical acoustic emission testing based on level 1 of ISO 9712 (Non-destructive testing – Qualification and certification of personnel) criteria. The essential aspects of ISO/DIS 18436-6 (Condition monitoring and diagnostics of machines – Requirements for training and certification of personnel, Part 6: Acoustic Emission) are explained, and readers can deepen their understanding with the help of practice exercises. This work presents the guiding principles of acoustic emission measurement, signal processing, algorithms for source location, measurement devices, applicability of testing methods, and measurement cases to support not only researchers in this field but also and especially NDT technicians.

  8. Passive broadband acoustic thermometry (United States)

    Anosov, A. A.; Belyaev, R. V.; Klin'shov, V. V.; Mansfel'd, A. D.; Subochev, P. V.


    The 1D internal (core) temperature profiles for the model object (plasticine) and the human hand are reconstructed using the passive acoustothermometric broadband probing data. Thermal acoustic radiation is detected by a broadband (0.8-3.5 MHz) acoustic radiometer. The temperature distribution is reconstructed using a priori information corresponding to the experimental conditions. The temperature distribution for the heated model object is assumed to be monotonic. For the hand, we assume that the temperature distribution satisfies the heat-conduction equation taking into account the blood flow. The average error of reconstruction determined for plasticine from the results of independent temperature measurements is 0.6 K for a measuring time of 25 s. The reconstructed value of the core temperature of the hand (36°C) generally corresponds to physiological data. The obtained results make it possible to use passive broadband acoustic probing for measuring the core temperatures in medical procedures associated with heating of human organism tissues.

  9. Acoustics of courtyard theatres

    Institute of Scientific and Technical Information of China (English)

    WANG Jiqing


    The traditional Chinese theatre was often built with a courtyard. In such open-top space, the absence of a roof would mean little reverberation and non-diffused sound field.Acoustically the situation is quite different from that of any enclosed space. The refore, theclassic room acoustics, such as Sabine reverberation formula, would no longer be applicable due to the lack of sound reflections from the ceiling. As the parameter of reverberation time T30 shows the decay rate only, it would not properly characterize the prominent change in the fine structure of the echogram, particularly in case of a large reduction of reflections during the decay process. The sense of reverbrance in a courtyard space would differ noticeably from that of the equivalent 3D-T30 in an enclosed space. Based upon the characteristic analysis of the sound field in an open-top space, this paper presents a preliminary study on the acoustics of the courtyard theatres.

  10. Acoustics waves and oscillations

    CERN Document Server

    Sen, S.N.


    Parameters of acoustics presented in a logical and lucid style Physical principles discussed with mathematical formulations Importance of ultrasonic waves highlighted Dispersion of ultrasonic waves in viscous liquids explained This book presents the theory of waves and oscillations and various applications of acoustics in a logical and simple form. The physical principles have been explained with necessary mathematical formulation and supported by experimental layout wherever possible. Incorporating the classical view point all aspects of acoustic waves and oscillations have been discussed together with detailed elaboration of modern technological applications of sound. A separate chapter on ultrasonics emphasizes the importance of this branch of science in fundamental and applied research. In this edition a new chapter ''Hypersonic Velocity in Viscous Liquids as revealed from Brillouin Spectra'' has been added. The book is expected to present to its readers a comprehensive presentation of the subject matter...

  11. Acoustically Induced Vibration of Structures: Reverberant Vs. Direct Acoustic Testing (United States)

    Kolaini, Ali R.; O'Connell, Michael R.; Tsoi, Wan B.


    Large reverberant chambers have been used for several decades in the aerospace industry to test larger structures such as solar arrays and reflectors to qualify and to detect faults in the design and fabrication of spacecraft and satellites. In the past decade some companies have begun using direct near field acoustic testing, employing speakers, for qualifying larger structures. A limited test data set obtained from recent acoustic tests of the same hardware exposed to both direct and reverberant acoustic field testing has indicated some differences in the resulting structural responses. In reverberant acoustic testing, higher vibration responses were observed at lower frequencies when compared with the direct acoustic testing. In the case of direct near field acoustic testing higher vibration responses appeared to occur at higher frequencies as well. In reverberant chamber testing and direct acoustic testing, standing acoustic modes of the reverberant chamber or the speakers and spacecraft parallel surfaces can strongly couple with the fundamental structural modes of the test hardware. In this paper data from recent acoustic testing of flight hardware, that yielded evidence of acoustic standing wave coupling with structural responses, are discussed in some detail. Convincing evidence of the acoustic standing wave/structural coupling phenomenon will be discussed, citing observations from acoustic testing of a simple aluminum plate. The implications of such acoustic coupling to testing of sensitive flight hardware will be discussed. The results discussed in this paper reveal issues with over or under testing of flight hardware that could pose unanticipated structural and flight qualification issues. Therefore, it is of paramount importance to understand the structural modal coupling with standing acoustic waves that has been observed in both methods of acoustic testing. This study will assist the community to choose an appropriate testing method and test setup in

  12. Room Acoustical Fields

    CERN Document Server

    Mechel, Fridolin


    This book presents the theory of room acoustical fields and revises the Mirror Source Methods for practical computational use, emphasizing the wave character of acoustical fields.  The presented higher methods include the concepts of “Mirror Point Sources” and “Corner sources which allow for an excellent approximation of complex room geometries and even equipped rooms. In contrast to classical description, this book extends the theory of sound fields describing them by their complex sound pressure and the particle velocity. This approach enables accurate descriptions of interference and absorption phenomena.

  13. Acoustic black holes

    CERN Document Server

    Visser, M


    Acoustic propagation in a moving fluid provides a conceptually clean and powerful analogy for understanding black hole physics. As a teaching tool, the analogy is useful for introducing students to both General Relativity and fluid mechanics. As a research tool, the analogy helps clarify what aspects of the physics are kinematics and what aspects are dynamics. In particular, Hawking radiation is a purely kinematical effect, whereas black hole entropy is intrinsically dynamical. Finally, I discuss the fact that with present technology acoustic Hawking radiation is almost experimentally testable.

  14. Suppression of Spontaneous Gas Oscillations by Acoustic Self-Feedback (United States)

    Biwa, Tetsushi; Sawada, Yoshiki; Hyodo, Hiroaki; Kato, Soichiro


    This paper demonstrates a method of acoustical self-feedback to suppress spontaneous gas oscillations such as those observed in combustors of gas-turbine engines. Whereas a conventional feedback system consists of electromechanical devices, the present method achieves acoustical self-feedback with a hollow tube that connects two positions of the oscillation system. A model oscillator of combustion-driven gas oscillations is designed and built to demonstrate the applicability of the self-feedback concept. Stability analysis through measurements of Q values (quality factor) of oscillations shows that the desired delay time and gain are obtained when the tube length is equal to the odd integer times half the wavelength of the anticipated acoustic oscillations.

  15. The "Uptake" of a Sport-for-Development Programme in South Africa (United States)

    Burnett, Cora


    This article reports on the "uptake" dynamics and resultant manifestations of a school-based, incentive-driven, sport-for-development programme in the South African context of poverty. The ecological systems theory of Brofenbrenner, the theory of complexity and a neo-liberal framework underpin the social constructions of local meanings…

  16. Energy Management Programmes for Industry

    Energy Technology Data Exchange (ETDEWEB)



    The IEA Policy Pathway publications provide details on how to implement specific recommendations drawn from the IEA 25 Energy Efficiency Policy Recommendations. This Policy Pathway, jointly produced by the International Energy Agency and the Institute for Industrial Productivity, develops the critical steps for policy makers implementing energy management programmes for industry. Optimising energy use in industry is essential to improve industrial competitiveness and achieve wider societal goals such as energy security, economic recovery and development, climate change mitigation and environmental protection. While there is significant potential to decrease energy consumption in this sector, opportunities to improve energy efficiency are still under-exploited. Energy management programmes have shown to be instrumental in addressing many of the barriers that inhibit wide-scale uptake of energy management in industry. The Policy Pathway builds on lessons learned from country experiences and provides actionable guidance on how to plan and design, implement, evaluate and monitor energy management programmes for industry.

  17. A Statistical Programme Assignment Model

    DEFF Research Database (Denmark)

    Rosholm, Michael; Staghøj, Jonas; Svarer, Michael

    When treatment effects of active labour market programmes are heterogeneous in an observable way  across the population, the allocation of the unemployed into different programmes becomes a particularly  important issue. In this paper, we present a statistical model designed to improve the present...... assignment  mechanism, which is based on the discretionary choice of case workers. This is done in a duration model context, using the timing-of-events framework to identify causal effects. We compare different assignment  mechanisms, and the results suggest that a significant reduction in the average...... duration of unemployment spells may result if a statistical programme assignment model is introduced. We discuss several issues regarding the  plementation of such a system, especially the interplay between the statistical model and  case workers....

  18. The RESCueH Programme

    DEFF Research Database (Denmark)

    Søgaard Nielsen, Anette; Nielsen, Bent; Andersen, Kjeld;


    Excessive alcohol consumption is one of the most important lifestyle factors affecting the disease burden in the Western world. The results of treatment in daily practice are modest at best. The aim of the RESCueH programme is to develop and evaluate methods, which are as practice-near as possible......, and therefore can be implemented quickly and easily in everyday clinical practice. It is the first clinical alcohol programme to be transatlantic in scope, with implementation in treatment centers located in Denmark, Germany and the US. The RESCueH programme comprises 5 randomized controlled trials......, and the studies can be expected to result in (1) more patients starting treatment in specialized outpatient clinics, (2) a greater number of elderly patients being treated, (3) increased patient motivation for treatment and thus improved adherence, (4) more patients with stable positive outcomes after treatment...

  19. The internationalisation of postgraduate programmes

    DEFF Research Database (Denmark)

    Fink, Flemming Kobberøe; Andersen, Ole K.; Bak, Thomas;


    This paper presents the efforts and experiences of globalisation of the study programmes within electronic engineering at Aalborg University. The Project-Organised Problem-Based Learning Model, which have been employed since 1974 is presented and discussed. The consequences this has for the inter......This paper presents the efforts and experiences of globalisation of the study programmes within electronic engineering at Aalborg University. The Project-Organised Problem-Based Learning Model, which have been employed since 1974 is presented and discussed. The consequences this has...... for the international students are presented and discussed in terms of e.g. the teamwork situation, professional and cultural differences. A student enrolment programme, implemented through the provision of scholarships, jointly paid by government and industry funds is presented...

  20. Radon programmes and health marketing. (United States)

    Fojtikova, Ivana; Rovenska, Katerina


    Being aware of negative health effects of radon exposure, many countries aim for the reduction of the radon exposure of their population. The Czech radon programme was commenced >20 y ago. Since then experts have gathered a lot of knowledge, necessary legislation has been enacted, tens of thousands of inhabitants have been offered free measurement and subsidy for the mitigation. Despite the effort, the effectiveness of the radon programme seems to be poor. Newly built houses still exhibit elevated radon concentrations and the number of houses mitigated is very low. Is it possible to enhance the effectivity of radon programme while keeping it on a voluntary basis? One possible way is to employ health marketing that draws together traditional marketing theories and science-based strategies to prevention. The potential of using marketing principles in communication and delivery of radon information will be discussed.

  1. Parametric Analysis of Acoustical Requirements for Lateral Reflections: Melbourne Recital Hall Case Study

    Directory of Open Access Journals (Sweden)

    Erica Claustro


    Full Text Available This paper is an investigation of the Melbourne Recital Centre as a case study to define the parameters necessary for good acoustical quality as it relates to the Binaural Quality Index and determining the intimacy of the hall by its initial time delay gap. The Melbourne Recital Centre, designed by Ashton Raggatt McDougall Architects, is a significant case study, as its design was driven by the acoustic requirements of reflection and diffusion through Odeon Acoustical Software. It achieves the same acoustical quality of older, ornately designed shoebox concert halls, from the perspective of contemporary design and fabrication tools and techniques. The sleek design of the Melbourne Recital Centre successfully reflects sound waves in low, mid, and high frequencies due to corresponding wall panel differentiation in the corresponding scales, as engineered by Arup Acoustics.

  2. Dust-acoustic waves and stability in the permeating dust plasma: II. Power-law distributions

    CERN Document Server

    Gong, Jingyu; Du, Jiulin


    The dust-acoustic waves and their stability driven by a flowing dust plasma when it cross through a static (target) dust plasma (the so-called permeating dust plasma) are investigated when the components of the dust plasma obey the power-law q-distributions in nonextensive statistics. The frequency, the growth rate and the stability condition of the dust-acoustic waves are derived under this physical situation, which express the effects of the nonextensivity as well as the flowing dust plasma velocity on the dust-acoustic waves in this dust plasma. The numerical results illustrate some new characteristics of the dust-acoustic waves, which are different from those in the permeating dust plasma when the plasma components are the Maxwellian distribution. In addition, we show that the flowing dust plasma velocity has a significant effect on the dust-acoustic waves in the permeating dust plasma with the power-law q-distribution.

  3. A viable method to predict acoustic streaming in presence of cavitation. (United States)

    Louisnard, O


    The steady liquid flow observed under ultrasonic emitters generating acoustic cavitation can be successfully predicted by a standard turbulent flow calculation. The flow is driven by the classical averaged volumetric force density calculated from the acoustic field, but the inertial term in Navier-Stokes equations must be kept, and a turbulent solution must be sought. The acoustic field must be computed with a realistic model, properly accounting for dissipation by the cavitation bubbles [Louisnard, Ultrason. Sonochem., 19, (2012) 56-65]. Comparison with 20kHz experiments, involving the combination of acoustic streaming and a perpendicular forced flow in a duct, shows reasonably good agreement. Moreover, the persistence of the cavitation effects on the wall facing the emitter, in spite of the deflection of the streaming jet, is correctly reproduced by the model. It is also shown that predictions based either on linear acoustics with the correct turbulent solution, or with Louisnard's model with Eckart-Nyborg's theory yields unrealistic results.

  4. Developer Driven and User Driven Usability Evaluations

    DEFF Research Database (Denmark)

    Bruun, Anders


    Usability evaluation provide software development teams with insights on the degree to which a software application enables a user to achieve his/her goals, how fast these goals can be achieved, how easy it is to learn and how satisfactory it is in use Although usability evaluations are crucial....... The four primary findings from my studies are: 1) The developer driven approach reveals a high level of thoroughness and downstream utility. 2) The user driven approach has higher performance regarding validity 3) The level of reliability is comparable between the two approaches. 4) The user driven...

  5. Evoked acoustic emission

    DEFF Research Database (Denmark)

    Elberling, C; Parbo, J; Johnsen, N J;


    Stimulated acoustic emissions were recorded in response to tonal stimuli at 60 dB p.e. SPL in a small group of normal-hearing adults. Power spectral analysis reveals that the evoked activity from each ear contains energy in preferential frequency bands and the change of stimulus frequency has onl...

  6. Evoked acoustic emission

    DEFF Research Database (Denmark)

    Elberling, C; Parbo, J; Johnsen, N J;


    Stimulated acoustic emissions were recorded in response to tonal stimuli at 60 dB p.e. SPL in a small group of normal-hearing adults. Power spectral analysis reveals that the evoked activity from each ear contains energy in preferential frequency bands and the change of stimulus frequency has only...

  7. Indigenous Acoustic Detection. (United States)


    considerable distances, and they act as good sensors of human presence. Though singing insects are ubiquitous in warm areas, even in the desert ( Nevo and...methodology. DTIC. CD-58-PL. Lloyd, J. E. 1981. Personnel communication. Nevo , E. and S. A. Blondheim. 1972. Acoustic isolation in the speciation of

  8. Deep Water Ocean Acoustics (United States)


    sound speed profile is range-independent; since there is little expectation there will be significant mesoscale phenomenon given the lack of solar ...34 Journal of the Acoustical Society of America 93 (4), 1736-1742 (1993). 2 Chris H. Harrison and Martin Siderius, "Effective Parameters for Matched

  9. Planar near-field acoustical holography based on equivalent source method and its experimental investigation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yongbin; CHEN Xinzhao; BI Chuanxing; CHEN Jian


    The current main approach to reconstruct and predict the acoustic field of a planar source is Near-field Acoustical Holography (NAH) based on FFT. But this method has some disadvantages such as wraparound error and edge Gibbs phenomena which will contaminate the results badly. A planar NAH based on equivalent source approach is developed, which has no wraparound error and edge Gibbs phenomena, and it is beneficial for engineering application.The experimental results of acoustic radiation generated by a point-driven plate with clamped boundaries validate the correctness and availability of the method.

  10. An acoustic energy framework for predicting combustion-driven acoustic instabilities in premixed gas-turbines (United States)

    Ibrahim, Zuhair M. A.

    The purpose of this study was to discover and assess student financial services delivered to students enrolled at East Tennessee State University. The research was undertaken for institutional self-improvement. The research explored changes that have occurred in student financial services in the dynamic higher education market. The research revealed universities pursued best practices for the delivery of student financial services through expanded employee knowledge, restructured organizations, and integrated information technologies. The research was conducted during October and November, 2006. The data were gathered from an online student survey of student financial services. The areas researched included: the Bursar office, the Financial Aid office, and online services. The results of the data analysis revealed problems with the students' perceived quality of existing financial services and the additional services students desire. The research focused on student perceptions of the quality of financial services by age and gender classifications and response categories. Although no statistically significant difference was found between the age-gender classifications on the perception of the quality of the financial services studied, the research adds to our understanding of student financial services at East Tennessee State University. Recommendation for continued research included annual surveys of segmented student populations that include ethnicity, age, gender, and educational level. The research would be used for continuous improvement efforts and student relationship management. Also additional research was recommended for employee learning in relation to the institution's mission, goals, and values.

  11. Acoustic field modulation in regenerators (United States)

    Hu, J. Y.; Wang, W.; Luo, E. C.; Chen, Y. Y.


    The regenerator is a key component that transfers energy between heat and work. The conversion efficiency is significantly influenced by the acoustic field in the regenerator. Much effort has been spent to quantitatively determine this influence, but few comprehensive experimental verifications have been performed because of difficulties in modulating and measuring the acoustic field. In this paper, a method requiring two compressors is introduced and theoretically investigated that achieves acoustic field modulation in the regenerator. One compressor outputs the acoustic power for the regenerator; the other acts as a phase shifter. A RC load dissipates the acoustic power out of both the regenerator and the latter compressor. The acoustic field can be modulated by adjusting the current in the two compressors and opening the RC load. The acoustic field is measured with pressure sensors instead of flow-field imaging equipment, thereby greatly simplifying the experiment.

  12. Controlling sound with acoustic metamaterials

    DEFF Research Database (Denmark)

    Cummer, Steven A. ; Christensen, Johan; Alù, Andrea


    Acoustic metamaterials can manipulate and control sound waves in ways that are not possible in conventional materials. Metamaterials with zero, or even negative, refractive index for sound offer new possibilities for acoustic imaging and for the control of sound at subwavelength scales....... The combination of transformation acoustics theory and highly anisotropic acoustic metamaterials enables precise control over the deformation of sound fields, which can be used, for example, to hide or cloak objects from incident acoustic energy. Active acoustic metamaterials use external control to create......-scale metamaterial structures and converting laboratory experiments into useful devices. In this Review, we outline the designs and properties of materials with unusual acoustic parameters (for example, negative refractive index), discuss examples of extreme manipulation of sound and, finally, provide an overview...

  13. NDA National Graduate Programme 'nucleargraduates'

    Energy Technology Data Exchange (ETDEWEB)

    Dawson, Carl


    institutions and will have a blend of leading technical proficiency mixed with indications of 'high performer' potential. Professional - Throughout the programme the graduates will be working towards achieving professional qualifications though the relevant 'Institute' for their discipline, such as the IMECHE. The training and experience gained from the scheme is programmed around a syllabus of work and courses, which will be accredited retrospectively by the 'Institutes'. The two year 'initial professional development' programme whilst the graduate is with the NDA is then fitted into a further two years with stakeholders for their first 'substantive role'. Whilst there is no monetary contribution from the stakeholders there is a significant resource support from the programme stakeholders. They will provide a sophisticated matrix of support in attraction and assessment support, professional development, mentoring, training and scheme evaluation. The programme will be using cutting edge marketing, assessment, recruitment and training tools. It will also deliver a pioneering socio economic programme that will combine professional training with cultural and behavioural insight work. The aims of the programme are aligned with the NDA succession plan and Skills Strategy Document. The graduate profile by the end of the two year programme is 'mobile, professional, aware and ambitious.' The Programme is driven by a group comprising of companies across the industry including the NDA, SLC's, defence operators, operational power station organisations, regulators and the supply chain. Uniquely, the programme offers no 'specific job' with the NDA after the two year programme is completed. The programme will be integrated into the existing partners' schemes to ensure smooth progression. The Graduate's progress after 2 years will be facilitated by a careers service and formal rules governing the behaviour

  14. Programme documentation to control programme for Solar-tracker; Programdokumentation til styringsprogram til Solar-tracker

    Energy Technology Data Exchange (ETDEWEB)

    Rudbeck, C.


    The report contains the programme documentation partly for a programme to control of a tracking system and partly a programme, which uses this programme to make measurements of transmittance for covering layer. Both the transmittance measurement programme and the programme is built in Borland Pascal v7.0, and is compiled in Real mode for the use on a processor of the 80X86-family. The source code for the programme for transmittance measurements and the programmes (the positioning routines) are described in Appendix B. (EHS)

  15. Portugal's Secondary School Modernisation Programme (United States)

    Heitor, Teresa V.; Freire da Silva, Jose M. R.


    The aim of the Secondary School Modernisation Programme, being implemented in Portugal by "Parque Escolar, EPE", is based on the pursuit of quality and makes Portuguese education a potential international benchmark. This paper discusses the strategies adopted to reorganise school spaces. It describes the conceptual model and highlights the…

  16. The Massey Kiwi Friend Programme (United States)

    Ramsey, Philip; Ramsey, Deborah; Mason, Robyn


    Like many institutions, Massey University has experienced growth in enrolments of international students. Increasing numbers of international students has led to frustrations for international and domestic students, and for staff. This paper describes an innovative programme designed to help with the orientation of international students. Domestic…

  17. Summer Student Programme – Report

    CERN Document Server

    Bellora, Andrea


    This is the report on the studies about radiation damage on silicon strips detectors I've performed during my Summer Student Programme. A parameter to describe the damage amount has been defined, as well as his behaviour over time and absorbed dose.

  18. Portugal's Secondary School Modernisation Programme (United States)

    Heitor, Teresa V.; Freire da Silva, Jose M. R.


    The aim of the Secondary School Modernisation Programme, being implemented in Portugal by "Parque Escolar, EPE", is based on the pursuit of quality and makes Portuguese education a potential international benchmark. This paper discusses the strategies adopted to reorganise school spaces. It describes the conceptual model and highlights…

  19. Early diagnosis of acoustic neuroma by the vestibular test

    Energy Technology Data Exchange (ETDEWEB)

    Haid, T.; Rettinger, G.; Berg, M.; Wigand, M.E.


    In a series of 390 cases with suspicion of acoustic neurinomas 78 such tumors could be diagnosed, including 12 early stage neurinomas. This relatively high detection quote of small neurinomas is due to a special diagnostical programme: Every patient with unilateral and sensoneural hearingloss, independent of vertigo anamnesis or of the result of X-rays must be further examined by a vestibular test. All 78 patients with acoustic neuroma had pathological vestibular findings. The positional test turned out to be the most sensitive examination in the early diagnosis of acoustic neuromas and yields a still higher incidence than the thermic test: 95% of the patients with a neuroma showed pathological findings in the positional test. Every patient suffering from an unidentified unilateral and sensoneural hearingloss combined with a pathological result in the positional test must be further checked by a cisternomeatography or computerized tomography using airinsufflation. Every fifth of these patients showed typical signs of an acoustic neuroma in the neuroradiological tests. 68 neuromas are operated today and verfied histologically, 10 patients are still waiting for surgical treatment.

  20. Flat acoustic lens by acoustic grating with curled slits

    KAUST Repository

    Peng, Pai


    We design a flat sub-wavelength lens that can focus acoustic wave. We analytically study the transmission through an acoustic grating with curled slits, which can serve as a material with tunable impedance and refractive index for acoustic waves. The effective parameters rely on the geometry of the slits and are independent of frequency. A flat acoustic focusing lens by such acoustic grating with gradient effective refractive index is designed. The focusing effect is clearly observed in simulations and well predicted by the theory. We demonstrate that despite the large impedance mismatch between the acoustic lens and the matrix, the intensity at the focal point is still high due to Fabry-Perot resonance.

  1. Manipulate acoustic waves by impedance matched acoustic metasurfaces (United States)

    Wu, Ying; Mei, Jun; Aljahdali, Rasha

    We design a type of acoustic metasurface, which is composed of carefully designed slits in a rigid thin plate. The effective refractive indices of different slits are different but the impedances are kept the same as that of the host medium. Numerical simulations show that such a metasurface can redirect or reflect a normally incident wave at different frequencies, even though it is impedance matched to the host medium. We show that the underlying mechanisms can be understood by using the generalized Snell's law, and a unified analytic model based on mode-coupling theory. We demonstrate some simple realization of such acoustic metasurface with real materials. The principle is also extended to the design of planar acoustic lens which can focus acoustic waves. Manipulate acoustic waves by impedance matched acoustic metasurfaces.

  2. Programmable shape transformation of elastic spherical domes. (United States)

    Abdullah, Arif M; Braun, Paul V; Hsia, K Jimmy


    We investigate mismatch strain driven programmable shape transformation of spherical domes and report the effects of different geometric and structural characteristics on dome behavior in response to applied mismatch strain. We envision a bilayer dome design where the differential swelling of the inner layer with respect to the passive outer layer in response to changes in dome surroundings (such as the introduction of an organic solvent) introduces mismatch strain within the bilayer system and causes dome shape transformation. Finite element analysis reveals that, in addition to snap-through, spherical domes undergo bifurcation buckling and eventually gradual bending to morph into cylinders with increasing mismatch strain. Besides demonstrating how the snap-through energy barrier depends on the spherical dome shape, our analysis identifies three distinct groups of dome geometries based on their mismatch strain-transformed configuration relationships. Our experiments with polymer-based elastic bilayer domes that exhibit differential swelling in organic solvents qualitatively confirm the finite element predictions. We establish that, in addition to externally applied stimuli (mismatch strain), bilayer spherical dome morphing can be tuned and hence programmed through its geometry and structural characteristics. Incorporation of an elastic instability mechanism such as snap-through within the framework of stimuli-responsive functional devices can improve their response time which is otherwise controlled by diffusion. Hence, our proposed design guidelines can be used to realize deployable, multi-functional, reconfigurable, and therefore, adaptive structures responsive to a diverse set of stimuli across multiple length scales.

  3. Influence of thermal inhibitor position and temperature on vortex-shedding-driven pressure oscillations

    Institute of Scientific and Technical Information of China (English)

    Su Wanxing; Li Shipeng; Zhang Qiao; Li Junwei; Ye Qingqing; Wang Ningfei


    Vortex-acoustic coupling is one of the most important potential sources of combustion instability in solid rocket motors (SRMs).Based on the Von Karman Institute for Fluid Dynamics (VKI) experimental motor,the influence of the thermal inhibitor position and temperature on vortex-shedding-driven pressure oscillations is numerically studied via the large eddy simulation (LES)method.The simulation results demonstrate that vortex shedding is a periodic process and its accurate frequency can be numerically obtained.Acoustic modes could be easily excited by vortex shedding.The vortex shedding frequency and second acoustic frequency dominate the pressure oscillation characteristics in the chamber.Thermal inhibitor position and gas temperature have little effect on vortex shedding frequency,but have great impact on pressure oscillation amplitude.Pressure amplitude is much higher when the thermal inhibitor locates at the acoustic velocity anti-nodes.The farther the thermal inhibitor is to the nozzle head,the more vortex energy would be dissipated by the turbulence.Therefore,the vortex shedding amplitude at the second acoustic velocity antinode near 3/4L (L is chamber length) is larger than those of others.Besides,the natural acoustic frequencies increase with the gas temperature.As the vortex shedding frequency departs from the natural acoustic frequency,the vortex-acoustic feedback loop is decoupled.Consequently,both the vortex shedding and acoustic amplitudes decrease rapidly.

  4. A Martian acoustic anemometer. (United States)

    Banfield, Don; Schindel, David W; Tarr, Steve; Dissly, Richard W


    An acoustic anemometer for use on Mars has been developed. To understand the processes that control the interaction between surface and atmosphere on Mars, not only the mean winds, but also the turbulent boundary layer, the fluxes of momentum, heat and molecular constituents between surface and atmosphere must be measured. Terrestrially this is done with acoustic anemometers, but the low density atmosphere on Mars makes it challenging to adapt such an instrument for use on Mars. This has been achieved using capacitive transducers and pulse compression, and was successfully demonstrated on a stratospheric balloon (simulating the Martian environment) and in a dedicated Mars Wind Tunnel facility. This instrument achieves a measurement accuracy of ∼5 cm/s with an update rate of >20 Hz under Martian conditions.

  5. Acoustic absorption by sunspots (United States)

    Braun, D. C.; Labonte, B. J.; Duvall, T. L., Jr.


    The paper presents the initial results of a series of observations designed to probe the nature of sunspots by detecting their influence on high-degree p-mode oscillations in the surrounding photosphere. The analysis decomposes the observed oscillations into radially propagating waves described by Hankel functions in a cylindrical coordinate system centered on the sunspot. From measurements of the differences in power between waves traveling outward and inward, it is demonstrated that sunspots appear to absorb as much as 50 percent of the incoming acoustic waves. It is found that for all three sunspots observed, the amount of absorption increases linearly with horizontal wavenumber. The effect is present in p-mode oscillations with wavelengths both significantly larger and smaller than the diameter of the sunspot umbrae. Actual absorption of acoustic energy of the magnitude observed may produce measurable decreases in the power and lifetimes of high-degree p-mode oscillations during periods of high solar activity.


    Directory of Open Access Journals (Sweden)

    J. J. Almeida-Pérez


    Full Text Available In this paper appears a solution for acoustic emission analysis commonly known as noise. For the accomplishmentof this work a personal computer is used, besides sensors (microphones and boards designed and built for signalconditioning. These components are part of a virtual instrument used for monitoring the acoustical emission. Themain goal of this work is to develop a virtual instrument that supplies many important data as the result of ananalysis allowing to have information in an easy and friendly way. Moreover this information is very useful forstudying and resolving several situations in planning, production and testing areas.The main characteristics of the virtual instrument are: signal analysis in time, effective power measurement inDecibels (dB, average intensity taken from the principle of paired microphones, as well as the data analysis infrequency. These characteristics are included to handle two information channels.

  7. Electromagnetic acoustic imaging. (United States)

    Emerson, Jane F; Chang, David B; McNaughton, Stuart; Jeong, Jong Seob; Shung, K K; Cerwin, Stephen A


    Electromagnetic acoustic imaging (EMAI) is a new imaging technique that uses long-wavelength RF electromagnetic (EM) waves to induce ultrasound emission. Signal intensity and image contrast have been found to depend on spatially varying electrical conductivity of the medium in addition to conventional acoustic properties. The resultant conductivity- weighted ultrasound data may enhance the diagnostic performance of medical ultrasound in cancer and cardiovascular applications because of the known changes in conductivity of malignancy and blood-filled spaces. EMAI has a potential advantage over other related imaging techniques because it combines the high resolution associated with ultrasound detection with the generation of the ultrasound signals directly related to physiologically important electrical properties of the tissues. Here, we report the theoretical development of EMAI, implementation of a dual-mode EMAI/ultrasound apparatus, and successful demonstrations of EMAI in various phantoms designed to establish feasibility of the approach for eventual medical applications.

  8. Impact evaluation of child nutrition programmes

    NARCIS (Netherlands)

    Hoorweg, J.C.


    Review of current practices and recent developments in impact evaluation of nutrition programmes for preschool children in developing countries. A survey of the major types of nutrition programmes for young children - nutrition education, food supplementation, and nutrition rehabilitation - is follo

  9. Feedback control of acoustic musical instruments: collocated control using physical analogs. (United States)

    Berdahl, Edgar; Smith, Julius O; Niemeyer, Günter


    Traditionally, the average professional musician has owned numerous acoustic musical instruments, many of them having distinctive acoustic qualities. However, a modern musician could prefer to have a single musical instrument whose acoustics are programmable by feedback control, where acoustic variables are estimated from sensor measurements in real time and then fed back in order to influence the controlled variables. In this paper, theory is presented that describes stable feedback control of an acoustic musical instrument. The presentation should be accessible to members of the musical acoustics community who may have limited or no experience with feedback control. First, the only control strategy guaranteed to be stable subject to any musical instrument mobility is described: the sensors and actuators must be collocated, and the controller must emulate a physical analog system. Next, the most fundamental feedback controllers and the corresponding physical analog systems are presented. The effects that these controllers have on acoustic musical instruments are described. Finally, practical design challenges are discussed. A proof explains why changing the resonance frequency of a musical resonance requires much more control power than changing the decay time of the resonance.

  10. A heat-driven thermoacoustic cryocooler capable of reaching below liquid hydrogen temperature

    Institute of Scientific and Technical Information of China (English)

    HU JianYing; LUO ErCang; DAI Wei; Zhou Yuan


    A "double-gas acoustic amplifier" is introduced to couple a thermoacoustic heat engine and a two-stage pulse tube cooler in this paper. Compared with previous acoustic amplifiers, this new acoustic amplifier maintains the function of amplification for pressure amplitude. In particular, the novel acoustic amplifier with a reservoir makes it possible to install an acoustic transparent but gas blocking elastic membrane between the engine and the cooler. Thus, the engine can use nitrogen as the working gas to work at low frequency; and meanwhile, the cooler can still use helium as the working gas to maintain its high performance. With this new amplifier, the cooling temperature of a two-stage pulse tube cooler driven by an energy-focused thermoacoustic engine reached 18.7 K.

  11. Acoustic emission source modeling

    Directory of Open Access Journals (Sweden)

    Hora P.


    Full Text Available The paper deals with the acoustic emission (AE source modeling by means of FEM system COMSOL Multiphysics. The following types of sources are used: the spatially concentrated force and the double forces (dipole. The pulse excitation is studied in both cases. As a material is used steel. The computed displacements are compared with the exact analytical solution of point sources under consideration.

  12. Acoustic Characterization of Soil (United States)


    ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER Dept. of Electrical & Computer Enginnering Dept Natural Resources...same transduction device is used for transmit and receive, and the broad-band mechanical matching between the transduction device and the acoustic...has a direct influence over the imaging depth for a given dynamic range. Figure 10 demonstrated the influence of the roundtrip propagation loss as a

  13. Acoustic Communications for UUVs (United States)


    through use of high-gain, error-control coding coupled with a modified decision feedback equalizer (DFE) which allows the gain to be exploited prior to...finished it wait for feedback from the receiver. At the host each packet is decoded and displayed if it is correct, or added to a list of bad packets if it...Systems Laboratory, Florida Alantic University, July 1998. L. Freitag el al: ‘A Bidriectional Coherent Acoustic Communications Systems for Underwater

  14. Acoustically enhanced heat transport

    Energy Technology Data Exchange (ETDEWEB)

    Ang, Kar M.; Hung, Yew Mun; Tan, Ming K., E-mail: [School of Engineering, Monash University Malaysia, 47500 Bandar Sunway, Selangor (Malaysia); Yeo, Leslie Y. [Micro/Nanophysics Research Laboratory, RMIT University, Melbourne, VIC 3001 (Australia); Friend, James R. [Department of Mechanical and Aerospace Engineering, University of California, San Diego, California 92093 (United States)


    We investigate the enhancement of heat transfer in the nucleate boiling regime by inducing high frequency acoustic waves (f ∼ 10{sup 6} Hz) on the heated surface. In the experiments, liquid droplets (deionized water) are dispensed directly onto a heated, vibrating substrate. At lower vibration amplitudes (ξ{sub s} ∼ 10{sup −9} m), the improved heat transfer is mainly due to the detachment of vapor bubbles from the heated surface and the induced thermal mixing. Upon increasing the vibration amplitude (ξ{sub s} ∼ 10{sup −8} m), the heat transfer becomes more substantial due to the rapid bursting of vapor bubbles happening at the liquid-air interface as a consequence of capillary waves travelling in the thin liquid film between the vapor bubble and the air. Further increases then lead to rapid atomization that continues to enhance the heat transfer. An acoustic wave displacement amplitude on the order of 10{sup −8} m with 10{sup 6} Hz order frequencies is observed to produce an improvement of up to 50% reduction in the surface temperature over the case without acoustic excitation.

  15. Acoustics, computers and measurements (United States)

    Truchard, James J.


    The human ear has created a high standard for the requirements of acoustical measurements. The transient nature of most acoustical signals has limited the success of traditional volt meters. Professor Hixson's pioneering work in electroacoustical measurements at ARL and The University of Texas helped set the stage for modern computer-based measurements. The tremendous performance of modern PCs and extensive libraries of signal processing functions in virtual instrumentation application software has revolutionized the way acoustical measurements are made. Today's analog to digital converters have up to 24 bits of resolution with a dynamic range of over 120 dB and a single PC processor can process 112 channels of FFTs at 4 kHz in real time. Wavelet technology further extends the capabilities for analyzing transients. The tools available for measurements in speech, electroacoustics, noise, and vibration represent some of the most advanced measurement tools available. During the last 50 years, Professor Hixson has helped drive this revolution from simple oscilloscope measurements to the modern high performance computer-based measurements.

  16. Acoustically enhanced heat transport (United States)

    Ang, Kar M.; Yeo, Leslie Y.; Friend, James R.; Hung, Yew Mun; Tan, Ming K.


    We investigate the enhancement of heat transfer in the nucleate boiling regime by inducing high frequency acoustic waves (f ˜ 106 Hz) on the heated surface. In the experiments, liquid droplets (deionized water) are dispensed directly onto a heated, vibrating substrate. At lower vibration amplitudes (ξs ˜ 10-9 m), the improved heat transfer is mainly due to the detachment of vapor bubbles from the heated surface and the induced thermal mixing. Upon increasing the vibration amplitude (ξs ˜ 10-8 m), the heat transfer becomes more substantial due to the rapid bursting of vapor bubbles happening at the liquid-air interface as a consequence of capillary waves travelling in the thin liquid film between the vapor bubble and the air. Further increases then lead to rapid atomization that continues to enhance the heat transfer. An acoustic wave displacement amplitude on the order of 10-8 m with 106 Hz order frequencies is observed to produce an improvement of up to 50% reduction in the surface temperature over the case without acoustic excitation.

  17. A theory evaluation of an induction programme

    Directory of Open Access Journals (Sweden)

    Kenrick Hendricks


    Full Text Available Orientation: An induction programme is commonly used to help new employees understand their job within the organisation. Research purpose: The main aim of this study was to examine whether or not the programme theory of an induction programme was plausible and would lead to the intended outcomes as described by the programme manager.Motivation for the study: Induction training is one of the most common training programmes in an organisation. However, there is little research to evaluate whether or not the activities of an induction programme will lead to the intended outcomes of such a programme.Research design, approach and method: This theory evaluation used a descriptive design. One hundred and thirteen employees of a media company completed a ten-item, five-point Likert scale which measured their perceptions of the programme’s outcome, identification with the organisation and intentions to stay with the organisation.Main findings: From this theory evaluation it was apparent that an induction programme based on an implausible programme theory could be problematic. An implausible programme theory affects the design of the programme activities and unsuitable activities may not deliver the desired outcomes.Practical/managerial implications: The intention of the evaluation is to guide human resource managers through a process of replacing an implausible programme theory with one that is plausible, and which ensures better alignment of programme activities and outcomes.Contribution/value-add: The evaluators showed how a plausible programme theory could improve programme design. This redesigned induction programme may lead to benefits, such as staff retention and company identification, rather than the vague assumption that it has been conforming to a legal obligation.

  18. Agri-Environment Programme for Croatia


    Znaor, Darko; Karoglan Todorović, Sonja


    In the period 2002-2004, the Netherlands Government's Pin-Matra programme funded an international project aiming to support the introduction of an agri-environment programme (AE) in Croatia. The project resulted in proposals for national and pilot agri-environment programmes. The project addressed key actors working on agri-environmental issues in Croatia, such as government representatives, scientists, farmers, environmental and nature conservation NGOs. An AE Programme has been operatin...

  19. The JOSHUA (J80) system programmer`s manual

    Energy Technology Data Exchange (ETDEWEB)

    Smetana, A.O.; McCort, J.T.; Westmoreland, B.W.


    The JOSHUA system routines (JS routines) can be used to manage a JOSHUA data base and execute JOSHUA modules on VAX/VMS and IBM/MVS computer systems. This manual provides instructions for using the JS routines and information about the internal data structures and logic used by the routines. It is intended for use primarily by JOSHUA systems programmers, however, advanced applications programmers may also find it useful. The JS routines are, as far as possible, written in ANSI FORTRAN 77 so that they are easily maintainable and easily portable to different computer systems. Nevertheless, the JOSHUA system provides features that are not available in ANSI FORTRAN 77, notably dynamic module execution and a data base of named, variable length, unformatted records, so some parts of the routines are coded in nonstandard FORTRAN or assembler (as a last resort). In most cases, the nonstandard sections of code are different for each computer system. To make it easy for programmers using the JS routines to avoid naming conflicts, the JS routines and common block all have six character names that begin with the characters {open_quotes}JS.{close_quotes} Before using this manual, one should be familiar with the JOSHUA system as described in {open_quotes}The JOSHUA Users` Manual,{close_quotes} ANSI FORTRAN 77, and at least one of the computer systems for which the JS routines have been implemented.

  20. High-Frequency Seafloor Acoustics

    CERN Document Server

    Jackson, Darrell R


    High-Frequency Seafloor Acoustics is the first book in a new series sponsored by the Office of Naval Research on the latest research in underwater acoustics. This exciting new title provides ready access to experimental data, theory, and models relevant to high-frequency seafloor acoustics and will be of interest to sonar engineers and researchers working in underwater acoustics. The physical characteristics of the seafloor affecting acoustic propagation and scattering are covered, including physical and geoacoustic properties and surface roughness. Current theories for acoustic propagation in sediments are presented along with corresponding models for reflection, scattering, and seafloor penetration. The main text is backed up by an extensive bibliography and technical appendices.

  1. Latest Trends in Acoustic Sensing

    Directory of Open Access Journals (Sweden)

    Cinzia Caliendo


    Full Text Available Acoustics-based methods offer a powerful tool for sensing applications. Acoustic sensors can be applied in many fields ranging from materials characterization, structural health monitoring, acoustic imaging, defect characterization, etc., to name just a few. A proper selection of the acoustic wave frequency over a wide spectrum that extends from infrasound (<20 Hz up to ultrasound (in the GHz–band, together with a number of different propagating modes, including bulk longitudinal and shear waves, surface waves, plate modes, etc., allow acoustic tools to be successfully applied to the characterization of gaseous, solid and liquid environments. The purpose of this special issue is to provide an overview of the research trends in acoustic wave sensing through some cases that are representative of specific applications in different sensing fields.

  2. Fundamentals of Shallow Water Acoustics

    CERN Document Server

    Katsnelson, Boris; Lynch, James


    Shallow water acoustics (SWA), the study of how low and medium frequency sound propagates and scatters on the continental shelves of the world's oceans, has both technical interest and a large number of practical applications. Technically, shallow water poses an interesting medium for the study of acoustic scattering, inverse theory, and propagation physics in a complicated oceanic waveguide. Practically, shallow water acoustics has interest for geophysical exploration, marine mammal studies, and naval applications. Additionally, one notes the very interdisciplinary nature of shallow water acoustics, including acoustical physics, physical oceanography, marine geology, and marine biology. In this specialized volume, the authors, all of whom have extensive at-sea experience in U.S. and Russian research efforts, have tried to summarize the main experimental, theoretical, and computational results in shallow water acoustics, with an emphasis on providing physical insight into the topics presented.

  3. Acceptors of Population Programme in Pakistan




    Data from Pakistan's population planning programme, the Nationa11mpact Survey (1968) and the Pakistan Fertility Survey (1975) are ana1ysed to estimate the number of 'births averted' in Pakistan by various contraceptives. Limitations of the population planning programme statistics for determining the impact of the programme on fertility rates are pointed out.

  4. Financial Aspects of Loyalty Programmes Implementation

    Directory of Open Access Journals (Sweden)

    Agnieszka Woś


    Full Text Available Financial aspects of implementation of loyalty programmes are the most crucial factors moldings their effectiveness. The following article covers costs of loyalty programmes and stages of their creation and functioning in companies. It also interprets the part of KIMSF 13 Loyalty Programmes which deals with the ways of recognizing income in case of granting promotional points to the customers.

  5. Spacecraft Internal Acoustic Environment Modeling (United States)

    Chu, S. Reynold; Allen, Chris


    The objective of the project is to develop an acoustic modeling capability, based on commercial off-the-shelf software, to be used as a tool for oversight of the future manned Constellation vehicles. The use of such a model will help ensure compliance with acoustic requirements. Also, this project includes modeling validation and development feedback via building physical mockups and conducting acoustic measurements to compare with the predictions.

  6. Acoustic Imaging of Combustion Noise (United States)

    Ramohalli, K. N.; Seshan, P. K.


    Elliposidal acoustic mirror used to measure sound emitted at discrete points in burning turbulent jets. Mirror deemphasizes sources close to target source and excludes sources far from target. At acoustic frequency of 20 kHz, mirror resolves sound from region 1.25 cm wide. Currently used by NASA for research on jet flames. Produces clearly identifiable and measurable variation of acoustic spectral intensities along length of flame. Utilized in variety of monitoring or control systems involving flames or other reacting flows.

  7. Acoustic streaming with heat exchange (United States)

    Gubaidullin, A. A.; Pyatkova, A. V.


    Acoustic streaming in a cylindrical cavity with heat exchange is numerically investigated. The cavity is filled with air. The boundaries of the cavity are maintained at constant temperature. The features of acoustic streaming manifesting with the decrease in the frequency of vibration in comparison with the resonant frequency are determined. The influence of the nonlinearity of process on acoustic streaming is shown. The nonlinearity is caused by the increase of the vibration amplitude.

  8. The Implementation of a Behavioural Support Programme: Teachers' Perceptions of the Programme and Themselves as Providers (United States)

    Ingemarson, Maria; Bodin, Maria; Rubenson, Birgitta; Guldbrandsson, Karin


    Purpose: The purpose of this paper is to investigate how teachers received and perceived the school programme Prevention in School (PS), a positive behavioural support programme; how did the teachers perceive the programme characteristics and themselves as providers; and how did this affect programme implementation? Design/methodology/approach:…

  9. JavaScript programmer's reference

    CERN Document Server

    Valentine, Thomas


    JavaScript Programmer's Reference is an invaluable resource that won't stray far from your desktop (or your tablet!). It contains detailed information on every JavaScript object and command, and combines that reference with practical examples showcasing how you can use those commands in the real world. Whether you're just checking the syntax of a method or you're starting out on the road to JavaScript mastery, the JavaScript Programmer's Reference will be an essential aid.  With a detailed and informative tutorial section giving you the ins and outs of programming with JavaScript and the DOM f

  10. Combined Environment Acoustic Chamber (CEAC) (United States)

    Federal Laboratory Consortium — Purpose: The CEAC imposes combined acoustic, thermal and mechanical loads on aerospace structures. The CEAC is employed to measure structural response and determine...

  11. Acoustic Communications Measurement Systems (ACOMMS) (United States)

    Federal Laboratory Consortium — FUNCTION: Design and develop adaptive signal processing techniques to improve underwater acoustic communications and networking. Phase coherent and incoherent signal...

  12. Programmable snapping composites with bio-inspired architecture. (United States)

    Schmied, Jascha U; Le Ferrand, Hortense; Ermanni, Paolo; Studart, André R; Arrieta, Andres F


    The development of programmable self-shaping materials enables the onset of new and innovative functionalities in many application fields. Commonly, shape adaptation is achieved by exploiting diffusion-driven swelling or nano-scale phase transition, limiting the change of shape to slow motion predominantly determined by the environmental conditions and/or the materials specificity. To address these shortcomings, we report shape adaptable programmable shells that undergo morphing via a snap-through mechanism inspired by the Dionaea muscipula leaf, known as the Venus fly trap. The presented shells are composite materials made of epoxy reinforced by stiff anisotropic alumina micro-platelets oriented in specific directions. By tailoring the microstructure via magnetically-driven alignment of the platelets, we locally tune the pre-strain and stiffness anisotropy of the composite. This novel approach enables the fabrication of complex shapes showing non-orthotropic curvatures and stiffness gradients, radically extending the design space when compared to conventional long-fibre reinforced multi-stable composites. The rare combination of large stresses, short actuation times and complex shapes, results in hinge-free artificial shape adaptable systems with large design freedom for a variety of morphing applications.

  13. Analog circuit for controlling acoustic transducer arrays

    Energy Technology Data Exchange (ETDEWEB)

    Drumheller, Douglas S. (Cedar Crest, NM)


    A simplified ananlog circuit is presented for controlling electromechanical transducer pairs in an acoustic telemetry system. The analog circuit of this invention comprises a single electrical resistor which replaces all of the digital components in a known digital circuit. In accordance with this invention, a first transducer in a transducer pair of array is driven in series with the resistor. The voltage drop across this resistor is then amplified and used to drive the second transducer. The voltage drop across the resistor is proportional and in phase with the current to the transducer. This current is approximately 90 degrees out of phase with the driving voltage to the transducer. This phase shift replaces the digital delay required by the digital control circuit of the prior art.


    Busquets, A. M.


    The Programmable Display Pushbutton (PDP) is a pushbutton device available from Micro Switch which has a programmable 16 x 35 matrix of LEDs on the pushbutton surface. Any desired legends can be displayed on the PDPs, producing user-friendly applications which greatly reduce the need for dedicated manual controls. Because the PDP can interact with the operator, it can call for the correct response before transmitting its next message. It is both a simple manual control and a sophisticated programmable link between the operator and the host system. The Programmable Display Pushbutton Legend Editor, PDPE, is used to create the LED displays for the pushbuttons. PDPE encodes PDP control commands and legend data into message byte strings sent to a Logic Refresh and Control Unit (LRCU). The LRCU serves as the driver for a set of four PDPs. The legend editor (PDPE) transmits to the LRCU user specified commands that control what is displayed on the LED face of the individual pushbuttons. Upon receiving a command, the LRCU transmits an acknowledgement that the message was received and executed successfully. The user then observes the effect of the command on the PDP displays and decides whether or not to send the byte code of the message to a data file so that it may be called by an applications program. The PDPE program is written in FORTRAN for interactive execution. It was developed on a DEC VAX 11/780 under VMS. It has a central memory requirement of approximately 12800 bytes. It requires four Micro Switch PDPs and two RS-232 VAX 11/780 terminal ports. The PDPE program was developed in 1985.

  15. LEP Celebration : the official programme

    CERN Document Server

    CERN. Geneva


    At 14:00: Groupe de Jazz "Wolfgang & The Werewolves" . The official programme begins at 15:00 with an introduction from the Director General, and Professor Martinus Veltman will give the keynote speech. Heads of national delegations represented at ministerial level will then make their speeches, following which a commemorative plaque will be unveiled. A specially commissioned ballet by Maurice Béjart will bring the ceremony to a close.

  16. Fast reactor programme in India

    Indian Academy of Sciences (India)

    P Chellapandi; P R Vasudeva Rao; Prabhat Kumar


    Role of fast breeder reactor (FBR) in the Indian context has been discussed with appropriate justification. The FBR programme since 1985 till 2030 is highlighted focussing on the current status and future direction of fast breeder test reactor (FBTR), prototype fast breeder reactor (PFBR) and FBR-1 and 2. Design and technological challenges of PFBR and design and safety targets with means to achieve the same are the major highlights of this paper.

  17. Programmability of Co-antidot lattices of optimized geometry (United States)

    Schneider, Tobias; Langer, Manuel; Alekhina, Julia; Kowalska, Ewa; Oelschlägel, Antje; Semisalova, Anna; Neudert, Andreas; Lenz, Kilian; Potzger, Kay; Kostylev, Mikhail P.; Fassbender, Jürgen; Adeyeye, Adekunle O.; Lindner, Jürgen; Bali, Rantej


    Programmability of stable magnetization configurations in a magnetic device is a highly desirable feature for a variety of applications, such as in magneto-transport and spin-wave logic. Periodic systems such as antidot lattices may exhibit programmability; however, to achieve multiple stable magnetization configurations the lattice geometry must be optimized. We consider the magnetization states in Co-antidot lattices of ≈50 nm thickness and ≈150 nm inter-antidot distance. Micromagnetic simulations were applied to investigate the magnetization states around individual antidots during the reversal process. The reversal processes predicted by micromagnetics were confirmed by experimental observations. Magnetization reversal in these antidots occurs via field driven transition between 3 elementary magnetization states – termed G, C and Q. These magnetization states can be described by vectors, and the reversal process proceeds via step-wise linear operations on these vector states. Rules governing the co-existence of the three magnetization states were empirically observed. It is shown that in an n × n antidot lattice, a variety of field switchable combinations of G, C and Q can occur, indicating programmability of the antidot lattices.

  18. A hot air driven thermoacoustic-Stirling engine

    Energy Technology Data Exchange (ETDEWEB)

    Tijani, M.E.H.; Spoelstra, S. [ECN Biomass and Energy Efficiency, Petten (Netherlands)


    Significant energy savings can be obtained by implementing a thermally driven heat pump into industrial or domestic applications. Such a thermally driven heat pump uses heat from a high-temperature source to drive the system which upgrades an abundantly available heat source (industrial waste heat, air, water, geothermal). A way to do this is by coupling a thermoacoustic engine with a thermoacoustic heat pump. The engine is driven by a burner and produces acoustic power and heat at the required temperature. The acoustic power is used to pump heat in the heat pump to the required temperature. This system is attractive since it uses a noble gas as working medium and has no moving mechanical parts. This paper deals with the first part of this system: the engine. In this study, hot air is used to simulate the flue gases originating from a gas burner. This is in contrast with a lot of other studies of thermoacoustic engines that use an electrical heater as heat source. Using hot air resembles to a larger extent the real world application. The engine produces about 300W of acoustic power with a performance of 41% of the Carnot efficiency at a hot air temperature of 620C.

  19. The INTEGRAL LMXRB Monitoring Programme

    CERN Document Server

    Paizis, A; Vilhu, O; Chernyakova, M; Tikkanen, T; Bazzano, A; Beckmann, V; Chenevez, J; Cocchi, M; Ebisawa, K; Farinelli, R; Frontera, F; Giménez, A; Goldoni, P; Hannikainen, D C; Kuulkers, E; Lund, N; Oosterbroek, T; Piraino, S; Rodríguez, J; Santangelo, A; Walter, R; Zdziarski, A A; Heras, J A Z


    Our collaboration is responsible for the study of a sample of 72 low mass X-ray binaries (LMXRB) using the INTEGRAL Core Programme data. In this paper we describe the monitoring programme we have started and the current variability and spectral results on a sample of 8 persistently bright LMXRBs hosting a neutron star (Z and Atoll sources). Current results show that among our sample of sources there seems to be no important difference in the variability of Z sources with respect to Atolls and the first colour-colour and hardness intensity diagrams built in the "traditional" energy bands display the expected patterns. Z sources seem to be harder than the bright Atolls of our sample (above 20 keV) and present no evident cut-off until about 50 keV. A hint of a non-thermal hard tail is seen in Sco X-1 with ISGRI and SPI, similarly to what was previously detected by D'Amico et al. (2001) with RXTE. These results, even if preliminary, show the importance of such a programme and the potential underlying it to unders...

  20. Acoustic transparency and slow sound using detuned acoustic resonators

    DEFF Research Database (Denmark)

    Santillan, Arturo Orozco; Bozhevolnyi, Sergey I.


    We demonstrate that the phenomenon of acoustic transparency and slowsound propagation can be realized with detuned acoustic resonators (DAR), mimicking thereby the effect of electromagnetically induced transparency (EIT) in atomic physics. Sound propagation in a pipe with a series of side...

  1. Query Driven Visualization

    CERN Document Server

    Buddelmeijer, Hugo


    The request driven way of deriving data in Astro-WISE is extended to a query driven way of visualization. This allows scientists to focus on the science they want to perform, because all administration of their data is automated. This can be done over an abstraction layer that enhances control and flexibility for the scientist.

  2. Enlargement of the External Mobility Programme

    CERN Document Server

    HR Department


    The External Mobility Programme was launched at the end of September 2007. Initially, the programme was aimed at staff members on limited-duration contracts, having received formal notification of the termination of their employment contract at CERN, to help them towards their next employment. The programme provides a privileged, fast-track entry into the recruitment process of partner companies. Despite the short time since its inception, the programme has already delivered some encouraging and concrete results in terms of interviews granted to participating staff. The Programme has raised considerable interest from both CERN personnel as well as from several major European companies. CERN Management has decided to broaden the scope of the External Mobility Programme. The Programme is now open to: All staff members whose limited duration contract will end in less than one year, as well as all those with indefinite contracts. All fellows who have been employed by CERN fo...

  3. Enlargement of the External Mobility Programme

    CERN Document Server

    HR Department


    The External Mobility Programme was launched at the end of September 2007. Initially, the programme was aimed at staff members on limited-duration contracts having received formal notification of the termination of their employment contract at CERN, to help them towards their next employment. The programme provides a privileged, fast-track entry into the recruitment process of partner companies. Despite the short time since its inception, the programme has already delivered some encouraging and concrete results in terms of interviews granted to participating staff. The Programme has attracted considerable interest from both CERN personnel as well as from several major European companies. The CERN Management has decided to broaden the scope of the External Mobility Programme. The Programme is now open to: All staff members whose limited duration contract will end in less than one year, as well as all those with indefinite contracts. All fellows who have been employed by CE...

  4. Swiss Biomass Programme - Overview report on the 2007 research programme; Programm Biomasse: Ueberblicksbericht zum Forschungsprogramm 2007

    Energy Technology Data Exchange (ETDEWEB)

    Binggeli, D.; Guggisberg, B.


    This illustrated report for the Swiss Federal Office of Energy (SFOE) presents an overview of the results obtained in 2007 within the framework of the Swiss Biomass research programme. The potential for biomass use in Switzerland is reviewed and the emphases of the national programme are discussed. The results obtained are noted for the following areas: process optimisation, including - amongst others - particle emissions and control aspects as well as combined wood-pellets and solar heating systems. Projects involving non-wood biomass are reported on, including biomass digesters and various biogas systems. Further reports deal with the analysis and optimisation of material flows, organic pollutants and methane losses. New conversion technologies are reported on. Further reports deal with basic strategies and concepts in the area of biomass usage. National and international co-operation is also discussed. A selection of innovative pilot and demonstration projects is also presented and research and development projects are listed.

  5. Integrating acoustic analysis in the architectural design process using parametric modelling

    DEFF Research Database (Denmark)

    Peters, Brady


    This paper discusses how parametric modeling techniques can be used to provide architectural designers with a better understanding of the acoustic performance of their designs and provide acoustic engineers with models that can be analyzed using computational acoustic analysis software. Architects...... are increasingly using parametric modeling techniques in their design processes to allow the exploration of large numbers of design options using multiple criteria. Parametric modeling software can be performance-driven and sound has the potential to become one of these performance-driven dimensions. This can...... provide a method by which architects and engineers can work together more efficiently and communicate better. This research is illustrated through the design of an architectural project, a new school in Copenhagen, Denmark by JJW Architects, where parametric modeling techniques have been used in different...

  6. Frequency steerable acoustic transducers (United States)

    Senesi, Matteo

    Structural health monitoring (SHM) is an active research area devoted to the assessment of the structural integrity of critical components of aerospace, civil and mechanical systems. Guided wave methods have been proposed for SHM of plate-like structures using permanently attached piezoelectric transducers, which generate and sense waves to evaluate the presence of damage. Effective interrogation of structural health is often facilitated by sensors and actuators with the ability to perform electronic, i.e. phased array, scanning. The objective of this research is to design an innovative directional piezoelectric transducer to be employed for the localization of broadband acoustic events, or for the generation of Lamb waves for active interrogation of structural health. The proposed Frequency Steerable Acoustic Transducers (FSATs) are characterized by a spatial arrangement of active material which leads to directional characteristics varying with frequency. Thus FSATs can be employed both for directional sensing and generation of guided waves without relying on phasing and control of a large number of channels. The analytical expression of the shape of the FSATs is obtained through a theoretical formulation for continuously distributed active material as part of a shaped piezoelectric device. The FSAT configurations analyzed in this work are a quadrilateral array and a geometry which corresponds to a spiral in the wavenumber domain. The quadrilateral array is experimentally validated, confirming the concept of frequency-dependent directionality. Its limited directivity is improved by the Wavenumber Spiral FSAT (WS-FSAT), which, instead, is characterized by a continuous frequency dependent directionality. Preliminary validations of the WS-FSAT, using a laser doppler vibrometer, are followed by the implementation of the WS-FSAT as a properly shaped piezo transducer. The prototype is first used for localization of acoustic broadband sources. Signal processing

  7. Acoustic Mechanical Feedthroughs (United States)

    Sherrit, Stewart; Walkemeyer, Phillip; Bao, Xiaoqi; Bar-Cohen, Yoseph; Badescu, Mircea


    Electromagnetic motors can have problems when operating in extreme environments. In addition, if one needs to do mechanical work outside a structure, electrical feedthroughs are required to transport the electric power to drive the motor. In this paper, we present designs for driving rotary and linear motors by pumping stress waves across a structure or barrier. We accomplish this by designing a piezoelectric actuator on one side of the structure and a resonance structure that is matched to the piezoelectric resonance of the actuator on the other side. Typically, piezoelectric motors can be designed with high torques and lower speeds without the need for gears. One can also use other actuation materials such as electrostrictive, or magnetostrictive materials in a benign environment and transmit the power in acoustic form as a stress wave and actuate mechanisms that are external to the benign environment. This technology removes the need to perforate a structure and allows work to be done directly on the other side of a structure without the use of electrical feedthroughs, which can weaken the structure, pipe, or vessel. Acoustic energy is pumped as a stress wave at a set frequency or range of frequencies to produce rotary or linear motion in a structure. This method of transferring useful mechanical work across solid barriers by pumping acoustic energy through a resonant structure features the ability to transfer work (rotary or linear motion) across pressure or thermal barriers, or in a sterile environment, without generating contaminants. Reflectors in the wall of barriers can be designed to enhance the efficiency of the energy/power transmission. The method features the ability to produce a bi-directional driving mechanism using higher-mode resonances. There are a variety of applications where the presence of a motor is complicated by thermal or chemical environments that would be hostile to the motor components and reduce life and, in some instances, not be

  8. Taming Acoustic Cavitation

    CERN Document Server

    Rivas, David Fernandez; Enriquez, Oscar R; Versluis, Michel; Prosperetti, Andrea; Gardeniers, Han; Lohse, Detlef


    In this fluid dynamics video we show acoustic cavitation occurring from pits etched on a silicon surface. By immersing the surface in a liquid, gas pockets are entrapped in the pits which upon ultrasonic insonation, are observed to shed cavitation bubbles. Modulating the driving pressure it is possible to induce different behaviours based on the force balance that determines the interaction among bubbles and the silicon surface. This system can be used for several applications like sonochemical water treatment, cleaning of surfaces with deposited materials such as biofilms.

  9. Wind turbine acoustics (United States)

    Hubbard, Harvey H.; Shepherd, Kevin P.


    Available information on the physical characteristics of the noise generated by wind turbines is summarized, with example sound pressure time histories, narrow- and broadband frequency spectra, and noise radiation patterns. Reviewed are noise measurement standards, analysis technology, and a method of characterizing wind turbine noise. Prediction methods are given for both low-frequency rotational harmonics and broadband noise components. Also included are atmospheric propagation data showing the effects of distance and refraction by wind shear. Human perception thresholds, based on laboratory and field tests, are given. Building vibration analysis methods are summarized. The bibliography of this report lists technical publications on all aspects of wind turbine acoustics.

  10. Acoustic Ground-Impedance Meter (United States)

    Zuckerwar, A. J.


    Helmoltz resonator used in compact, portable meter measures acoustic impedance of ground or other surfaces. Earth's surface is subject of increasing acoustical investigations because of its importance in aircraft noise prediction and measurment. Meter offers several advantages. Is compact and portable and set up at any test site, irrespective of landscape features, weather or other environmental condition.

  11. Propagation of Ion Acoustic Perturbations

    DEFF Research Database (Denmark)

    Pécseli, Hans


    Equations describing the propagation of ion acoustic perturbations are considered, using the assumption that the electrons are Boltzman distributed and isothermal at all times. Quasi-neutrality is also considered.......Equations describing the propagation of ion acoustic perturbations are considered, using the assumption that the electrons are Boltzman distributed and isothermal at all times. Quasi-neutrality is also considered....

  12. Acoustic Center or Time Origin?

    DEFF Research Database (Denmark)

    Staffeldt, Henrik


    The paper discusses the acoustic center in relation to measurements of loudspeaker polar data. Also, it presents the related concept time origin and discusses the deviation that appears between positions of the acoustic center found by wavefront based and time based measuring methods....

  13. Acoustic cavitation and sonochemistry

    NARCIS (Netherlands)

    Stricker, L.


    Sonochemistry is the use of cavitation for achieving a chemical conversion. When microbubbles are driven in the nonlinear regime, localized extreme temperatures (up to 10000 K) and pressures (up to 1000 bar) can be reached upon collapse, the surrounding liquid remaining ambient,thus giving origin to

  14. Instant RSpec test driven development how-to

    CERN Document Server

    Feduke, Charles


    Filled with practical, step-by-step instructions and clear explanations for the most important and useful tasks. A concise guide that delivers immediate results with practical recipes on learning practical hints.This book is aimed at Ruby developers with beginner level expertise who want to use RSpec and test driven development methodology to improve the code they write. Experienced programmers new to Ruby will also benefit from this book which also covers creating testable, idiomatic Ruby code

  15. Observing the formation of flare-driven coronal rain


    Scullion, E.; Rouppe van der Voort, L.; Antolin, P.; Wedemeyer, S.; Vissers, G.; E. P. Kontar; Gallagher, P


    PA. GV are funded by the European Research Council under the European Union Seventh Framework Programme (FP7/2007-2013) / ERC grant agreement nr. 291058 Flare-driven coronal rain can manifest from rapidly cooled plasma condensations near coronal loop-tops in thermally unstable post-flare arcades. We detect 5 phases that characterise the post-flare decay:heating, evaporation, conductive cooling dominance for ~120 s, radiative/ enthalpy cooling dominance for ~4700 s and finally catastrophic ...

  16. Acoustic Absorption in Porous Materials (United States)

    Kuczmarski, Maria A.; Johnston, James C.


    An understanding of both the areas of materials science and acoustics is necessary to successfully develop materials for acoustic absorption applications. This paper presents the basic knowledge and approaches for determining the acoustic performance of porous materials in a manner that will help materials researchers new to this area gain the understanding and skills necessary to make meaningful contributions to this field of study. Beginning with the basics and making as few assumptions as possible, this paper reviews relevant topics in the acoustic performance of porous materials, which are often used to make acoustic bulk absorbers, moving from the physics of sound wave interactions with porous materials to measurement techniques for flow resistivity, characteristic impedance, and wavenumber.

  17. Acoustics and Hearing

    CERN Document Server

    Damaske, Peter


    When one listens to music at home, one would like to have an acoustic impression close to that of being in the concert hall. Until recently this meant elaborate multi-channelled sound systems with 5 or more speakers. But head-related stereophony achieves the surround-sound effect in living rooms with only two loudspeakers. By virtue of their slight directivity as well as an electronic filter the limitations previously common to two-speaker systems can be overcome and this holds for any arbitrary two-channel recording. The book also investigates the question of how a wide and diffuse sound image can arise in concert halls and shows that the quality of concert halls decisively depends on diffuse sound images arising in the onset of reverberation. For this purpose a strong onset of reverberation is modified in an anechoic chamber by electroacoustic means. Acoustics and Hearing proposes ideas concerning signal processing in the auditory system that explain the measured results and the resultant sound effects plea...

  18. MEMS Based Acoustic Array (United States)

    Sheplak, Mark (Inventor); Nishida, Toshikaza (Inventor); Humphreys, William M. (Inventor); Arnold, David P. (Inventor)


    Embodiments of the present invention described and shown in the specification aid drawings include a combination responsive to an acoustic wave that can be utilized as a dynamic pressure sensor. In one embodiment of the present invention, the combination has a substrate having a first surface and an opposite second surface, a microphone positioned on the first surface of the substrate and having an input and a first output and a second output, wherein the input receives a biased voltage, and the microphone generates an output signal responsive to the acoustic wave between the first output and the second output. The combination further has an amplifier positioned on the first surface of the substrate and having a first input and a second input and an output, wherein the first input of the amplifier is electrically coupled to the first output of the microphone and the second input of the amplifier is electrically coupled to the second output of the microphone for receiving the output sinual from the microphone. The amplifier is spaced from the microphone with a separation smaller than 0.5 mm.

  19. Acoustic data transmission method

    Energy Technology Data Exchange (ETDEWEB)

    Duckworth, A.


    This patent describes a method for transmitting time line data through a drillstring having drill pipe sections connected end-to-end by joints from a first location below the surface of the earth to a second location at or near the surface of the earth, the length and cross-sectional area of the drill pipe sections being different from the length and cross-sectional area of the joints. It comprises generating acoustic data signals having a single frequency content in at least one passband of the drillstring; transmitting the data signals through the drillstring from either the first location to the second location or from the second location to the first location during a time period prior to the onset of reflective interference caused by the data signals reflecting from along the length of the drillstring, the time period being equal to or less than the time for the data signals to travel three lengths of the drillstring; stopping the transmission of data signals at the onset of the reflective interference and allowing the acoustic signals to substantially attenuate; and detecting the data signals at the respective first or second location.

  20. Nondestructive Evaluation of Metal Fatigue Using Nonlinear Acoustics (United States)

    Cantrell, John H., Jr.


    Safe-life and damage-tolerant design philosophies of high performance structures have driven the development of various methods to evaluate nondestructively the accumulation of damage in such structures resulting from cyclic loading. Although many techniques have proven useful, none has been able to provide an unambiguous, quantitative assessment of damage accumulation at each stage of fatigue from the virgin state to fracture. A method based on nonlinear acoustics is shown to provide such a means to assess the state of metal fatigue. The salient features of an analytical model are presented of the microelastic-plastic nonlinearities resulting from the interaction of an acoustic wave with fatigue-generated dislocation substructures and cracks that predictably evolve during the metal fatigue process. The interaction is quantified by the material (acoustic) nonlinearity parameter extracted from acoustic harmonic generation measurements. The parameters typically increase monotonically by several hundred percent over the fatigue life of the metal, thus providing a unique measure of the state of fatigue. Application of the model to aluminum alloy 2024-T4, 410Cb stainless steel, and IN100 nickel-base superalloy specimens fatigued using different loading conditions yields good agreement between theory and experiment. Application of the model and measurement technique to the on-site inspection of steam turbine blades is discussed.

  1. Programmable Multi-Chip Module (United States)

    Kautz, David; Morgenstern, Howard; Blazek, Roy J.


    A multi-chip module comprising a low-temperature co-fired ceramic substrate having a first side on which are mounted active components and a second side on which are mounted passive components, wherein this segregation of components allows for hermetically sealing the active components with a cover while leaving accessible the passive components, and wherein the passive components are secured using a reflow soldering technique and are removable and replaceable so as to make the multi-chip module substantially programmable with regard to the passive components.

  2. Waste Disposal: The PRACLAY Programme

    Energy Technology Data Exchange (ETDEWEB)

    De Bruyn, D


    Principal achievements in 2000 with regard to the PRACLAY programme are presented. The PRACLAY project has been conceived: (1) to demonstrate the construction and the operation of a gallery for the disposal of HLW in a clay formation; (2) to improve knowledge on deep excavations in clay through modelling and monitoring; (3) to design, install and operate a complementary mock-up test (OPHELIE) on the surface. In 1999, efforts were focussed on the operation of the OPHELIE mock-up and the CLIPEX project to monitor the evolution of hydro-mechanical parameters of the Boom Clay Formation near the face of a gallery during excavation.

  3. Final Draft Programme Support Document

    DEFF Research Database (Denmark)

    Enemark, Ulrika; Schleimann, Finn; Vagnby, Bo Hellisen

    The HSPS III is the third phase of Danish support to the Ghanaian Health Sector. The support is in line with the Ministy of Health's Medium Term Strategy and the Second Five-Year Programme of Work; the latter also bring in line with the Ghana Poverty Reduction Strategy. The majority of funds (340...... million DKK) are chanelled through the common Health Account for all MOH expenditure items except staff salaries. The rest of the funds are utilised for support in the following specific areas: - Health estate and building management; - Improving access to health care; - Stregthening public and private...

  4. Academic Training Lecture - Regular Programme

    CERN Multimedia

    PH Department


    Regular Lecture Programme 9 May 2011 ACT Lectures on Detectors - Inner Tracking Detectors by Pippa Wells (CERN) 10 May 2011 ACT Lectures on Detectors - Calorimeters (2/5) by Philippe Bloch (CERN) 11 May 2011 ACT Lectures on Detectors - Muon systems (3/5) by Kerstin Hoepfner (RWTH Aachen) 12 May 2011 ACT Lectures on Detectors - Particle Identification and Forward Detectors by Peter Krizan (University of Ljubljana and J. Stefan Institute, Ljubljana, Slovenia) 13 May 2011 ACT Lectures on Detectors - Trigger and Data Acquisition (5/5) by Dr. Brian Petersen (CERN) from 11:00 to 12:00 at CERN ( Bldg. 222-R-001 - Filtration Plant )

  5. le programme SET-Routes

    CERN Multimedia

    CERN Audiovisual Service


    Les routes de la science sont plus escarpées pour les femmes Le programme SET-Routes, qui visait à sensibiliser les jeunes filles à l’intérêt des carrières scientifiques, a pris fin en avril. Porté par l’EMBL, l’EMBO et le CERN, il a mis en place un réseau de femmes scientifiques, des ambassadrices qui se sont rendues dans les établissements scolaires européens pour parler de leur parcours scientifique.

  6. First trial postural reactions to unexpected balance disturbances: a comparison with the acoustic startle reaction. (United States)

    Oude Nijhuis, Lars B; Allum, John H J; Valls-Solé, Josep; Overeem, Sebastiaan; Bloem, Bastiaan R


    Unexpected support-surface movements delivered during stance elicit "first trial" postural reactions, which are larger and cause greater instability compared with habituated responses. The nature of this first trial reaction remains unknown. We hypothesized that first trial postural reactions consist of a generalized startle reaction, with a similar muscle synergy as the acoustic startle response, combined with an automatic postural reaction. Therefore we compared acoustic startle responses to first trial postural reactions. Eight healthy subjects stood on a support surface that unexpectedly rotated backwards 10 times, followed by 10 startling acoustic stimuli, or vice versa. Outcome measures included full body kinematics and surface EMG from muscles involved in startle reactions or postural control. Postural perturbations and startling acoustic stimuli both elicited a clear first trial reaction, as reflected by larger kinematic and EMG responses. The ensuing habituation rate to repeated identical stimuli was comparable for neck and trunk muscles in both conditions. Onset latencies in neck muscles occurred significantly later for first trial perturbations compared with startle responses, but earlier in trunk muscles. Our results show that platform tilting initially induces reactions larger than needed to maintain equilibrium. For neck and trunk muscles, these first trial postural reactions resembled acoustic startle reflexes. First trial postural reactions may be triggered by interaction of afferent volleys formed by somatosensory and vestibular inputs. Acoustic startle reactions may also be partially triggered by vestibular inputs. Similar muscle activation driven by vestibular inputs may be the common element of first trial postural responses and acoustic startle reactions.

  7. Teaching in English-medium programmes

    DEFF Research Database (Denmark)

    Lauridsen, Karen M.; Cozart, Stacey Marie

    This contribution describes and discusses the module Teaching in English-medium programmes, an elective module offered as part of the teacher training programme for assistant professors (“adjunktpædagogikum”) at Aarhus University. In order to complete the whole programme, assistant professors must...... have at least one such elective module ( Aarhus University offers the teacher training programme in Danish and in English for international faculty. Teaching in English-medium programmes is part of the Danish track, but taught through English. Building...... on the foundation module in the whole course, this particular module has been established especially for those Danish assistant professors who are to teach in the EMI programmes. The intended learning outcomes are that, at the end of the course, participants should be able to plan and deliver their teaching...

  8. Anomalous absorption of laser light on ion acoustic fluctuations (United States)

    Rozmus, Wojciech; Bychenkov, Valery Yu.


    Theory of laser light absorption due to ion acoustic turbulence (IAT) is discussed in high Z plasmas where ion acoustic waves are weakly damped. Our theory applies to the whole density range from underdense to critical density plasmas. It includes an absorption rate for the resonance anomalous absorption due to linear conversion of electromagnetic waves into electron plasma oscillations by the IAT near the critical density in addition to the absorption coefficient due to enhanced effective electron collisionality. IAT is driven by large electron heat flux through the return current instability. Stationary spectra of IAT are given by weak plasma turbulence theory and applied in description of the anomalous absorption in the inertial confinement fusion plasmas at the gold walls of a hohlraum. This absorption is anisotropic in nature due to IAT angular anisotropy and differs for p- and s-polarization of the laser radiation. Possible experiments which could identify the resonance anomalous absorption in a laser heated plasma are discussed.

  9. Analytical description of nonlinear acoustic waves in the solar chromosphere (United States)

    Litvinenko, Yuri E.; Chae, Jongchul


    Aims: Vertical propagation of acoustic waves of finite amplitude in an isothermal, gravitationally stratified atmosphere is considered. Methods: Methods of nonlinear acoustics are used to derive a dispersive solution, which is valid in a long-wavelength limit, and a non-dispersive solution, which is valid in a short-wavelength limit. The influence of the gravitational field on wave-front breaking and shock formation is described. The generation of a second harmonic at twice the driving wave frequency, previously detected in numerical simulations, is demonstrated analytically. Results: Application of the results to three-minute chromospheric oscillations, driven by velocity perturbations at the base of the solar atmosphere, is discussed. Numerical estimates suggest that the second harmonic signal should be detectable in an upper chromosphere by an instrument such as the Fast Imaging Solar Spectrograph installed at the 1.6-m New Solar Telescope of the Big Bear Observatory.

  10. Apprendre à programmer avec Python

    CERN Document Server

    Swinnen, Gérard


    Quel meilleur choix pour apprendre la programmation qu'un langage moderne et élégant tel que Python, aussi bon pour le développement d'applications web que pour la réalisation de scripts système ou l'analyse de fichiers textuels ? Un support de cours réputé et adopté par de nombreux enseignants, avec 40 pages d'exercices corrigés Reconnu et utilisé par les enseignants de nombreuses écoles et IUT, complété d'exercices accompagnés de leurs corrigés, cet ouvrage original et érudit est une référence sur tous les fondamentaux de la programmation : choix d'une structure de données, paramétrage, modularité, orientation objet et héritage, conception d'interface, multithreading et gestion d'événements, protocoles de communication et gestion réseau, formulaires web et (GI, bases de données) jusqu'à la désormais indispensable norme Unicode (le format UTF-8).


    CERN Multimedia

    Academic Training; Tel. 73127


    1ST TERM 1ST OCTOBER - 23 NOVEMBER 2001 LECTURE SERIES FOR POSTGRADUATE STUDENTS The Autumn term of the Academic Training Programme is about to start. As usual, the first term includes lectures primarily dedicated to Post-graduate students. These are meant to help students complement the courses available from their home Universities with lectures on topics close to CERN activities. The lectures are nevertheless open to all CERN staff, and in particular to young Fellows. This year's series include courses on Accelerator Physics, on Field Theory, and on Symmetry Breaking Phenomena in Physics. The course on Accelerators by Dr. Wilson has been a regular feature on the Academic Training programme for many previous editions. This year, the course will be updated to include new sections on Colliders and on future facilities such as the Neutrino Factory. A good introduction to this very successful course can be found in the previous version of these lectures, available from the Web Lecture Archive Project: http://w...

  12. Laser-Driven Fusion. (United States)

    Gibson, A. F.


    Discusses the present status and future prospects of laser-driven fusion. Current research (which is classified under three main headings: laser-matter interaction processes, compression, and laser development) is also presented. (HM)

  13. Acoustic Signal Feature Extraction of Vehicle Targets

    Institute of Scientific and Technical Information of China (English)

    蓝金辉; 马宝华; 李科杰


    Acoustic signal feature extraction is an important part of target recognition. The mechanisms for producing acoustic signals and their propagation are analyzed to extract the features of the radiated noise from different targets. Analysis of the acoustic spectra of typical vehicle targets acquired outdoors shows that the vehicles can be classified based on the acoustic spectra and amplitudes.

  14. Discovery Driven Growth

    DEFF Research Database (Denmark)

    Bukh, Per Nikolaj


    Anmeldelse af Discovery Driven Growh : A breakthrough process to reduce risk and seize opportunity, af Rita G. McGrath & Ian C. MacMillan, Boston: Harvard Business Press. Udgivelsesdato: 14 august......Anmeldelse af Discovery Driven Growh : A breakthrough process to reduce risk and seize opportunity, af Rita G. McGrath & Ian C. MacMillan, Boston: Harvard Business Press. Udgivelsesdato: 14 august...

  15. The state repatriation programme: four years later

    Directory of Open Access Journals (Sweden)

    Kirillova Yelena


    Full Text Available This article analyses the problems of the state voluntary repatriation programme and describes its key functions and implementation mechanisms. The author identifies the causes of deceleration in the repatriation process as well as the weak points of the Programme and the ways to improve it. The article offers data on the resettlement of compatriots over the three years of the Programme implementation, its demographic structure, and the regions of resettlement.

  16. A comparison of two CSA treatment programmes



    The development of effective treatment programmes to ameliorate the sequelae of CSA is imperative. Ideally such programmes should address intrapsychic psychological difficulties through individually based child-focused interventions; peer-related interpersonal problems through group-based interventions; and difficulties within the family and wider social network through family therapy and systemic interventions. It would be expected that some programmes might be more effective than others for...

  17. Budgeting for a district VISION 2020 programme

    Directory of Open Access Journals (Sweden)

    Susan Lewallen


    Full Text Available Core concepts of a strong VISION 2020 programme Many eye care professionals view the prospect of budgeting with about as much pleasure as a visit to the dentist! Nevertheless, if VISION 2020 is going to succeed, programme managers will have to acquire some basic skills in budgeting. First, it is useful to identify some of the core concepts of a strong, practical VISION 2020 programme to be considered when preparing a budget.

  18. The anti-torture norm and cooperation in the CIA black site programme

    DEFF Research Database (Denmark)

    Keating, Vincent Charles


    Does the interstate cooperation in the CIA rendition programme imply the anti-torture norm was severely degraded in the war on terror? Most scholarship currently suggests yes, pointing to the widespread cooperation of dozens of states, including many liberal democracies, in a programme designed...... to facilitate torture. This article argues that this conclusion is driven primarily by a focus on outcome, that states cooperated, and ignores the process through which cooperation happened. Using the data provided in the Senate report on the CIA’s detention and interrogation programme, this article...... demonstrates that studying the process of cooperation instead of merely the outcome allows us to see that the anti-torture norm had continuous causal effects that are currently unrecognised in the literature. This finding not only provides a counterpoint to much of the literature on the United States rendition...

  19. Building a global business continuity programme. (United States)

    Lazcano, Michael


    Business continuity programmes provide an important function within organisations, especially when aligned with and supportive of the organisation's goals, objectives and organisational culture. Continuity programmes for large, complex international organisations, unlike those for compact national companies, are more difficult to design, build, implement and maintain. Programmes for international organisations require attention to structural design, support across organisational leadership and hierarchy, seamless integration with the organisation's culture, measured success and demonstrated value. This paper details practical, but sometimes overlooked considerations for building successful global business continuity programmes.

  20. A leadership programme for critical care. (United States)

    Crofts, Linda


    This paper describes the genesis, design and implementation of a leadership programme for critical care. This was an initiative funded by the National Health Service (NHS) Nursing Leadership Project and had at the core of its design flexibility to meet the needs of the individual hospitals, which took part in it. Participation was from the multi-disciplinary critical care team. Six NHS hospitals took part in the programme which was of 20 days duration and took place on hospital sites. The programme used the leadership model of as its template and had a number of distinct components; a baseline assessment, personal development, principles of leadership and critical case reviews. The programme was underpinned by three themes; working effectively in multi-professional teams to provide patient focussed care, managing change through effective leadership and developing the virtual critical care service. Each group set objectives pertinent to their own organisation's needs. The programme was evaluated by a self-reporting questionnaire; group feedback and feedback from stakeholders. Programme evaluation was positive from all the hospitals but it was clear that the impact of the programme varied considerably between the groups who took part. It was noted that there was some correlation between the success of the programme and organisational 'buy in' as well as the organisational culture within which the participants operated. A key feature of the programme success was the critical case reviews, which were considered to be a powerful learning tool and medium for group learning and change management.

  1. Acoustic classification of dwellings

    DEFF Research Database (Denmark)

    Berardi, Umberto; Rasmussen, Birgit


    Schemes for the classification of dwellings according to different building performances have been proposed in the last years worldwide. The general idea behind these schemes relates to the positive impact a higher label, and thus a better performance, should have. In particular, focusing on soun...... exchanging experiences about constructions fulfilling different classes, reducing trade barriers, and finally increasing the sound insulation of dwellings.......Schemes for the classification of dwellings according to different building performances have been proposed in the last years worldwide. The general idea behind these schemes relates to the positive impact a higher label, and thus a better performance, should have. In particular, focusing on sound...... insulation performance, national schemes for sound classification of dwellings have been developed in several European countries. These schemes define acoustic classes according to different levels of sound insulation. Due to the lack of coordination among countries, a significant diversity in terms...

  2. Acoustic cavitation movies (United States)

    Crum, Lawrence A.


    Acoustic cavitation is a phenomenon that occurs on microsecond time scales and micron length scales, yet, it has many macroscopic manifestations. Accordingly, it is often difficult, at least for the author, to form realistic physical descriptions of the specific mechanisms through which it expresses itself in our macroscopic world. For example, there are still many who believe that cavitation erosion is due to the shock wave that is emitted by bubble implosion, rather than the liquid jet created on asymmetric collapse...and they may be right. Over the years, the author has accumulated a number of movies and high-speed photographs of cavitation activity, which he uses to form his own visual references. In the time allotted, he will show a number of these movies and photographs and discuss their relevance to existing technological problems. A limited number of CDs containing the presented materials will be available to interested individuals. [Work supported in part by the NIH, USAMRMC, and the ONR.

  3. Acoustic/Magnetic Stress Sensor (United States)

    Heyman, J. S.; Namkung, M.


    High-resolution sensor fast, portable, does not require permanent bonding to structure. Sensor measures nondestructively type (compressive or tensile) and magnitude of stresses and stress gradients present in class of materials. Includes precise high-resolution acoustic interferometer, sending acoustic transducer, receiving acoustic transducer, electromagnet coil and core, power supply, and magnetic-field-measuring device such as Hall probe. This measurement especially important for construction and applications where steel is widely used. Sensor useful especially for nondestructive evaluation of stress in steel members because of portability, rapid testing, and nonpermanent installation.

  4. Acoustics of friction. (United States)

    Akay, Adnan


    This article presents an overview of the acoustics of friction by covering friction sounds, friction-induced vibrations and waves in solids, and descriptions of other frictional phenomena related to acoustics. Friction, resulting from the sliding contact of solids, often gives rise to diverse forms of waves and oscillations within solids which frequently lead to radiation of sound to the surrounding media. Among the many everyday examples of friction sounds, violin music and brake noise in automobiles represent the two extremes in terms of the sounds they produce and the mechanisms by which they are generated. Of the multiple examples of friction sounds in nature, insect sounds are prominent. Friction also provides a means by which energy dissipation takes place at the interface of solids. Friction damping that develops between surfaces, such as joints and connections, in some cases requires only microscopic motion to dissipate energy. Modeling of friction-induced vibrations and friction damping in mechanical systems requires an accurate description of friction for which only approximations exist. While many of the components that contribute to friction can be modeled, computational requirements become prohibitive for their contemporaneous calculation. Furthermore, quantification of friction at the atomic scale still remains elusive. At the atomic scale, friction becomes a mechanism that converts the kinetic energy associated with the relative motion of surfaces to thermal energy. However, the description of the conversion to thermal energy represented by a disordered state of oscillations of atoms in a solid is still not well understood. At the macroscopic level, friction interacts with the vibrations and waves that it causes. Such interaction sets up a feedback between the friction force and waves at the surfaces, thereby making friction and surface motion interdependent. Such interdependence forms the basis for friction-induced motion as in the case of

  5. Why do tougher caseworkers increase employment? The role of programme assignment as a causal mechanism

    DEFF Research Database (Denmark)

    Huber, Martin; Lechner, Michael; Mellace, Giovanni


    find that the positive employment effects of less accommodating caseworkers are not driven by a particularly effective mix of labour market programmes, but rather by other dimensions of the counselling process, possibly including threat effects of sanctions and pressure to accept jobs.......Previous research found that less accommodating caseworkers are more successful in placing unemployed workers into employment. This paper explores the causal mechanisms behind this result using semiparametric mediation analysis. Analysing rich linked jobseeker-caseworker data for Switzerland, we...

  6. Biomass programme: Overview of the 2006 Swiss research programme; Programm Biomasse. Ueberblicksbericht zum Forschungsprogramm 2006

    Energy Technology Data Exchange (ETDEWEB)

    Binggeli, D.; Guggisberg, B.


    This report for the Swiss Federal Office of Energy (SFOE) reviews work done within the framework of the Swiss biomass research programme in 2006. The programme concentrates on the efficient conversion of biomass into heat, electrical power and motor fuels. Projects concerned with the optimisation of processes are reported on, including low-particle-emission systems, control systems for bivalent heating installations, use of demanding biomass fuels, combined pellets and solar heating systems and the elimination of ammonia emissions. In the material flow area, measurement campaigns, organic pollutants in compost, the effects of fermented wastes in agriculture and methane losses in biogas conditioning are reported on. New conversion technologies are reviewed, including hydro-thermal gasification, plant-oil fuelled combined heat and power units, flameless burners and catalytic direct liquefaction. In the area of basics, studies and concepts, eco-balances and life-cycle analyses are reported on; the production of synthetic natural gas and the influence of combustion particles are discussed and decentralised power generation from solid biomass is reported on. National and international co-operation is reviewed. The report is concluded with a review of eight pilot and demonstration projects, a review of work to be done in 2007 and a list of research and demonstration projects.

  7. Power optimized programmable embedded controller

    CERN Document Server

    Kamaraju, M; Tilak, A V N; 10.5121/ijcnc.2010.2409


    Now a days, power has become a primary consideration in hardware design, and is critical in computer systems especially for portable devices with high performance and more functionality. Clock-gating is the most common technique used for reducing processor's power. In this work clock gating technique is applied to optimize the power of fully programmable Embedded Controller (PEC) employing RISC architecture. The CPU designed supports i) smart instruction set, ii) I/O port, UART iii) on-chip clocking to provide a range of frequencies , iv) RISC as well as controller concepts. The whole design is captured using VHDL and is implemented on FPGA chip using Xilinx .The architecture and clock gating technique together is found to reduce the power consumption by 33.33% of total power consumed by this chip.

  8. Field Evaluation of Programmable Thermostats

    Energy Technology Data Exchange (ETDEWEB)

    Sachs, O.; Tiefenbeck, V.; Duvier, C.; Qin, A.; Cheney, K.; Akers, C.; Roth, K.


    Prior research suggests that poor programmable thermostats usability may prevent their effective use to save energy. We hypothesized that home occupants with a high-usability thermostats would be more likely to use them to save energy than people with a basic thermostat. We randomly installed a high-usability thermostat in half the 77 apartments of an affordable housing complex, installing a basic thermostat in the other half. During the heating season, we collected space temperature and furnace on-off data to evaluate occupant interaction with the thermostats, foremost nighttime setbacks. We found that thermostat usability did not influence energy-saving behaviors, finding no significant difference in temperature maintained among apartments with high- and low-usability thermostats.

  9. Rheumatic Fever Programme in Samoa. (United States)

    Viali, Satupaitea; Saena, Puleiala; Futi, Vailogoua


    Rheumatic fever is very common in Samoa. The following paper describes the Rheumatic Fever Programme in Samoa and looks at the incidence of acute rheumatic fever (ARF) and rheumatic heart disease (RHD). The incidence of ARF has decreased to 30 per 100,000 in 2005, 12.8 per 100,000 in 2007, 7.3 per 100,000 in 2008, and 9.5 per 100,000 in 2009. The incidence of RHD has decreased to 40.2 per 100,000 in 2007, 34 per 100,000 in 2008, and 31.8 per 100,000 in 2009. Cardiac surgery in New Zealand is expensive, but is cheaper to perform in Samoa. RHD screening with echocardiogram at schools may be the best way to reduce the burden and suffering from RHD.

  10. The Immunization Programme In India

    Directory of Open Access Journals (Sweden)

    Sokhey J


    Full Text Available The immunization Programme was started in India in 1978 with the objective of reducing the mortality due to vaccine preventable diseases. Immunization coverage levels in infants and pregnant women have increased substantially over the last decade. Immunization coverage levels of 69 to 82% with various vaccines were reported in 1989-90. There is however, a wide disparity in the coverage levels in states and in the districts. While the priority to remains to increase immunization coverage levels, surveillance of vaccine preventable diseases is receiving high priority to identify weak pockets for intensification of immunization services and to document impact. Besides completeness of reporting., emphasis of the surveillance system in many areas has shifted to obtaining information on cases as early as possible to allow epidemiological investigations and effective follow-up action. The achievements in a large number of districts show that the goal of universal immunization, while difficult and challenging, is attainable.


    CERN Multimedia

    Françoise Benz


    1st TERM : November - December 2002   LECTURE SERIES FOR POSTGRADUATE STUDENTS 18, 19, 20, 21, 22 November 2002 Telling the Truth with Statistics by R. Barlow / Univ. of Manchester, UK 11:00-12:00 - Auditorium, bldg. 500     REGULAR LECTURE PROGRAMME 2, 3, 4, 5 December 2002 Introduction to String Theory by W. Lerche / CERN-TH 11:00-12:00 - Auditorium, bldg. 500 The lectures are open to all those interested, without application. The abstract of the lectures, as well as any change to the above information (title, dates, time, place etc.) will be published in the CERN bulletin, the WWW, and by Notices before each term and for each series of lectures. Françoise Benz Tel. 73127


    Institute of Scientific and Technical Information of China (English)

    LI Weibing; CHEN Jian; YU Fei; CHEN Xinzhao


    In the semi-free acoustic field, the actual acoustic pressure at any point is composed of two parts: The direct acoustic pressure and the reflected acoustic pressure. The general acoustic holographic theories and algorithms request that there is only the direct acoustic pressure contained in the pressure at any point on the hologram surface, consequently, they cannot be used to reconstruct acoustic source and predict acoustic field directly. To take the reflected pressure into consideration, near-field acoustic holography for semi-free acoustic field based on wave superposition approach is proposed to realize the holographic reconstruction and prediction of the semi-free acoustic field, and the wave superposition approach is adopted as a holographic transform algorithm. The proposed theory and algorithm are realized and verified with a numerical example,and the drawbacks of the general theories and algorithms in the holographic reconstruction and prediction of the semi-free acoustic field are also demonstrated by this numerical example.

  13. Reverberant Acoustic Test Facility (RATF) (United States)

    Federal Laboratory Consortium — The very large Reverberant Acoustic Test Facility (RATF) at the NASA Glenn Research Center (GRC), Plum Brook Station, is currently under construction and is due to...

  14. Frequency Steered Acoustic Transducer Project (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project is to develop, fabricate, and characterize a novel frequency steered acoustic transducer (FSAT) for the...

  15. Cryogenic Acoustic Suppression Testing Project (United States)

    National Aeronautics and Space Administration — The proposed project will explore and test the feasibility and effectiveness of using a cryogenic fluid (liquid nitrogen) to facilitate acoustic suppression in a...


    Institute of Scientific and Technical Information of China (English)

    Yang Ruiliang; Wang Hongzhen


    It is shown that the basis of the ellipsoidal acoustic infinite element Burnett method,the multipole expansion,cannot represent real ellipsoidal acoustic field exactly.To solve the problem,a weight of angular direction is added to the multipole expansion.The comparison of the modified method and the prime method shows that the modified method can describe and solve the ellipsoidal acoustic field more accurately than ever.A dilating sphere is used to test the new method further.Unlike other infinite element methods,varied ratio of the ellipsoidal artificial boundary instead of sphere is used.The pressure value of the artificial boundary is utilized as the initial value of the new method.Then the radiating phenomena of the ellipsoidal acoustic field can be researched using the new method.These examples show the feasibility of the adaptive method.

  17. Frequency Steered Acoustic Transducer Project (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase II project is to fabricate, characterize, and verify performance of a new type of frequency steered acoustic transducer...

  18. Norwegian participation in the IEA Heat Pump Programme Annex 34 - final report

    Energy Technology Data Exchange (ETDEWEB)

    Nordtvedt, S.R.


    This report is the Norwegian team contribution to Task A within the IEA Heat Pumps Programme Annex 34 on #Left Double Quotation Mark#Thermally driven heat pumps#Right Double Quotation Mark#. It aims to give an overview of the thermally driven heat pump (TDHP) and chiller (TDC) market, recent developments in the area of TDHP and TDC, as well as to give an outlook of the progress of this technology. There are no Norwegian manufacturers on the TDHP market. There are only seven existing thermally driven absorption system installations in Norway. Three are district heat driven water/LiBr chillers, one is a steam driven water/LiBr chiller, one water/LiBr heat pump for flue gas condensation in a wood chip heating unit, and two gas driven ammonia-water chillers. The future market for thermally driven heat pumps and chillers in Norway is expected to be in combination of biomass, district heat or waste heat. (Author)

  19. Biological Effects of Acoustic Cavitation (United States)


    rectified diffusion. 56 III. STABLE CAVITATION A. Introduction There are manv areas associated with the biological effects of ultrasound in which the...used said as cavitation indicators. Further, if clinical ultrasound systems are found to be inducing cavitation , either stable or transient, it will...O BIOLOGICAL EFFECTS OF ACOUSTIC CAVITATION by Lawrence A. Crum -- Physical Acoustics Research Laboratory Department of Physics and Astronomy ’ CTE

  20. Autonomous Adaptive Acoustic Relay Positioning (United States)


    equipment construction and repair tasks [51]. Commercial ROVs range from large, versatile work-class vehicles like Soil Machine Dynamics (SMD) QUANTUM and...range-only formation control using teams of heterogeneous vehicles with wifi and acoustic communications. Shankar and Chitre formulated the multi-armed...acoustic communication and sensing by marine robots. IEEE Journal of Oceanographic Engineering, 38:522–533, 2013. [43] S. Shankar and Chitre. Tuning

  1. Acoustic Multipurpose Cargo Transfer Bag (United States)

    Baccus, Shelley


    The Logistics Reduction (LR) project within the Advanced Exploration Systems (AES) program is tasked with reducing logistical mass and repurposing logistical items. Multipurpose Cargo Transfer Bags (MCTB) are designed to be the same external volume as a regular cargo transfer bag, the common logistics carrier for the International Space Station. After use as a cargo bag, the MCTB can be unzipped and unfolded to be reused. This Acoustic MCTBs transform into acoustic blankets after the initial logistics carrying objective is complete.

  2. Acoustic Rectification in Dispersive Media (United States)

    Cantrell, John H.


    It is shown that the shapes of acoustic radiation-induced static strain and displacement pulses (rectified acoustic pulses) are defined locally by the energy density of the generating waveform. Dispersive properties are introduced analytically by assuming that the rectified pulses are functionally dependent on a phase factor that includes both dispersive and nonlinear terms. The dispersion causes an evolutionary change in the shape of the energy density profile that leads to the generation of solitons experimentally observed in fused silica.

  3. Study Acoustic Emissions from Composites (United States)

    Walker, James; Workman,Gary


    The purpose of this work will be to develop techniques for monitoring the acoustic emissions from carbon epoxy composite structures at cryogenic temperatures. Performance of transducers at temperatures ranging from ambient to cryogenic and the characteristics of acoustic emission from composite structures will be studied and documented. This entire effort is directed towards characterization of structures used in NASA propulsion programs such as the X-33.

  4. Integrated Human Development Programme in Angola


    UNDP - UNOPS EDINFODEC Project - Cooperazione italiana,


    This report is an excerpt from the sixth UNDP-UNOPS-Cooperazione Italiana Report on Multilateral Human Development Programmes (2004). The Integrated Human Development Programme in Angola began in 1999 and ended in 2003. It focused on the maintenance and consolidation of the Local Economic Development Agencies (LEDAs). The PDHI helped set up the LEDAs in the Provinces of Bengo, Benguela and Kwanza Sul.

  5. Tema 1: Programmering af robotenheder i grundskolen

    Directory of Open Access Journals (Sweden)

    Stine Ejsing-Duun


    Full Text Available I denne artikel undersøger vi potentialerne for at lære matematik gennem programmering af robotter. Vi foreslår en model med tre indbyrdes afhængige læringspotentialer, som programmering fordrer. Det omfatter elevens evne til at; (1 tænke i algoritmer, (2 producere viden og artefakter gennem brug af matematik og (3 foretage abstraktion og indkapsling. Programmering er blevet en del af grundskolens læringsmål i flere lande. I Danmark er programmering et læringsmål i forenklede fælles mål for Fysik/Kemi og desuden en del af den nationale undervisningsvejledning for matematik. En analyse af potentialerne i at anvende programmering i forbindelse med disse fag er derfor væsentlig. I denne artikel fokuserer vi på samspillet mellem matematik og programmering gennem litteraturstudier og analyse af empiriske situationer fra undervisning i programmering af LEGO Mindstorms. Teoretisk anvendes den instrumentelle tilgang til teknologi i matematikundervisning. Analysen viser en række måder, hvorpå didaktisk opmærksomhed på epistemisk forhandling kan understøtte læring af matematik gennem programmering.

  6. Sonic ingredients in television food programmes

    Directory of Open Access Journals (Sweden)

    Charlotte Rørdam Larsen


    Full Text Available The main focus of this article is the use, significance, and role of sound in food and food travel programmes, exemplified by cooking programmes broadcast on Danish television – public service and commercial channels. The aim is to demonstrate how sound and music in this kind of programme plays an important part mediating both the cooking and the kitchen as wellordered and well organized. The use of music represents flow, but refers also to locality, globality and identity, and is often linked to the notions of nostalgia, tradition and authenticity, and contributes to an aesthetization of food programmes as it forms part of the performance and presentation of meals. The early kitchen programmes emphasized on information, as a kind of living cooking books as the idea was to enlighten the housewives and their practices by challenging their common sense choices introducing a more French inspired kitchen. In relation to such kitchen programmes todays cooking programmes seem to appeal to a broader sensibility as they present us to the possibilities of modern life, and the chefs’ multisensuorious performances underlines this – often induced by the sound. It is through the sounds in food programmes that an authentic experience of taste and smell is mediated to the viewer: both through the lustful, approving sounds made by presenters and through the cooks’ handling of raw materials. What looks delicious, also smells and tastes delicious – mediated through sound.

  7. Teaching design engineering in an interdisciplinary programme

    NARCIS (Netherlands)

    Wits, Wessel; Homminga, Jasper; Endedijk, Maaike; Visscher, Klaasjan; Krab-Hüsken, Leonie; Berg, van den Frank; Wilhelm, Pascal


    ATLAS, the Academy of Technology and Liberal Arts & Sciences, is an interdisciplinary three-year Bachelor of Science honours programme for talented students that opened its doors in September 2013. This international programme uses the concept of project-led education to teach students to integrate

  8. Report Open Course Programme Wageningen UR, 2010

    NARCIS (Netherlands)

    Hijweege, W.L.; Dorp, van M.


    Annually, the Wageningen UR open course programme for mid-career professionals provides some six hundred individuals with the opportunity to update their competencies and insights. EL&I co-finances this course programme with the aim to maintain close linkages with international policy priorities

  9. Multi-output programmable quantum processor


    Yu, Yafei; Feng, Jian; Zhan, Mingsheng


    By combining telecloning and programmable quantum gate array presented by Nielsen and Chuang [Phys.Rev.Lett. 79 :321(1997)], we propose a programmable quantum processor which can be programmed to implement restricted set of operations with several identical data outputs. The outputs are approximately-transformed versions of input data. The processor successes with certain probability.

  10. Three years of an intensive Programme

    DEFF Research Database (Denmark)

    Pedersen, Jens Myrup; Lopez, Jose Manuel Guterrez Lopez; Kirikova, Marite;


    This paper summarizes valuable experiences and learning points from three years of the Erasmus funded Intensive Programme on “Implementing Europe’s Future Broadband Infrastructure”. The programme consisted of a course held each year 2012-2014 during two weeks of July, where 30-35 students and 10-...

  11. Concept of the Flemish human biomonitoring programme. (United States)

    Schoeters, Greet; Den Hond, Elly; Colles, Ann; Loots, Ilse; Morrens, Bert; Keune, Hans; Bruckers, Liesbeth; Nawrot, Tim; Sioen, Isabelle; De Coster, Sam; Van Larebeke, Nicolas; Nelen, Vera; Van de Mieroop, Els; Vrijens, Jan; Croes, Kim; Goeyens, Karen; Baeyens, Willy


    Since 2002 a human biomonitoring network has been established in Flanders (Belgium) as part of a programme on environmental health surveillance. The human biomonitoring network should support environmental health policy by identifying priorities for further action. The first cycle of the programme (2002-2006) confirmed the hypotheses that living in areas with different environmental pressure is reflected in different loads of environmental chemicals in the residents. In the second cycle of the programme (2007-2011) the number of environmental chemicals for which human biomonitoring data were obtained was expanded substantially. The goal of the Flemish programme is to use and translate the scientific results into policy actions. Its further orientation in the second cycle to human biomonitoring in hot spots and sensitive age groups or susceptible persons with underlying complications (e.g. persons with diabetes) are linked to these goals. Interaction with stakeholders is embedded in the programme emphasizing transparency of the choices that are made and direct communication. The Flemish human biomonitoring programme is organized centrally with major involvement of research partners from different disciplines which allows engrafting environmental health research on the programme. One of the major focuses is the question whether combinations of pollutants in the general population are associated with biological effects. The objective of this paper is to review and discuss the options that were taken in the human biomonitoring programme in order to achieve its goals.

  12. Environmental Assessment of R&D Programmes

    DEFF Research Database (Denmark)

    Lyhne, Ivar; Byriel, Inger Pihl


    Despite their important role in shaping the technologies of the future, public research and development (R&D) programmes are rarely based on systematic assessments of the environmental effects. R&D programmes thus allocate a huge amount of financial resources to projects, which potentially may...

  13. Opto-acoustic cell permeation

    Energy Technology Data Exchange (ETDEWEB)

    Visuri, S R; Heredia, N


    Optically generated acoustic waves have been used to temporarily permeate biological cells. This technique may be useful for enhancing transfection of DNA into cells or enhancing the absorption of locally delivered drugs. A diode-pumped frequency-doubled Nd:YAG laser operating at kHz repetition rates was used to produce a series of acoustic pulses. An acoustic wave was formed via thermoelastic expansion by depositing laser radiation into an absorbing dye. Generated pressures were measured with a PVDF hydrophone. The acoustic waves were transmitted to cultured and plated cells. The cell media contained a selection of normally- impermeable fluorescent-labeled dextran dyes. Following treatment with the opto-acoustic technique, cellular incorporation of dyes, up to 40,000 Molecular Weight, was noted. Control cells that did not receive opto-acoustic treatment had unremarkable dye incorporation. Uptake of dye was quantified via fluorescent microscopic analysis. Trypan Blue membrane exclusion assays and fluorescent labeling assays confirmed the vitality of cells following treatment. This method of enhanced drug delivery has the potential to dramatically reduce required drug dosages and associated side effects and enable revolutionary therapies.

  14. Management of Industrial Processes with Programmable Logic Controller

    Directory of Open Access Journals (Sweden)

    Marius Tufoi


    Full Text Available In a modern economy, automation (the control is primarily to raise the competitiveness of a product, either directly through price or quality, or indirectly through the improvement of working conditions of staff productive. The control of industrial processes involves the management of dynamic systems that have continuous states. These systems are described by differential equations and, in general, analog inputs and outputs. Management of these systems is achieved, in general, with classical automation, by automation or with analog computers which contains modules with input / output analog performance. If states, inputs and outputs of a system can be modeled using binary variables, then these systems can be driven with Programmable Logic Controller.

  15. Programme impact on current contraception in Bangladesh. (United States)

    Latif, M A


    "This paper analyses the impact of three credit programmes--the Bangladesh Rural Advancement Committee (BRAC), the Bangladesh Rural Development Board's Rural Development-12 (BRDB RD-12), and the Grameen Bank (GB), on current rate of contraception. These programmes are targeted to alleviate poverty by providing group-based credit to the rural poor in creating self employment opportunities. With small credits, these programmes combine family planning activities in terms of consciousness raising, awareness building and motivation. Sample survey data are used to analyse the problem of impact evaluation. The analyses show that the BRAC and the GB programmes have [a] significantly positive impact on the current rate of contraception, while the BRDB RD-12 programme does not have any such impact. It is also found that education, both of female[s] and male[s] separately, and child survivorship have independently positive impact[s] on current contraception."

  16. Programmer`s manual for CAMCON: Compliance Assessment Methodology CONtroller

    Energy Technology Data Exchange (ETDEWEB)

    Rechard, R.P. [Sandia National Labs., Albuquerque, NM (United States); Gilkey, A.P.; Rudeen, D.K.; Byle, K.A. [New Mexico Engineering Research Inst., Albuquerque, NM (United States); Iuzzolino, H.J. [Geo-Centers, Inc., Albuquerque, NM (United States)


    CAMCON, the Compliance Assessment Methodology CONtroller, is an analysis system that assists in assessing the compliance of the Waste Isolation Pilot Plant (WIPP) with applicable long-term regulations of the US Environmental Protection Agency, including Subpart B of the Environmental Standards for the Management and Disposal of spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes, 40 CFR 191 and 40CFR268.6, which is the portion of the Land Disposal Restrictions implementing the Resource, Conservative, and Recovery Act of 1976, as amended that states the conditions for disposal of hazardous chemical wastes. This manual provides an architectural overview of the CAMCON system. Furthermore this manual presents guidelines and presents suggestions for programmers developing the many different types of software necessary to investigate various events and physical processes of the WIPP. These guidelines include user interface requirements, minimum quality assurance requirements, coding style suggestions, and the use of numerous software libraries developed specifically for or adapted for the CAMCON system.

  17. Building Digital Economy - The Research Councils Programme and the Vision (United States)

    Hand, John

    We at the Research Councils believe that there are many aspects of society and business that could be transformed by the innovative design and use of digital technologies. This has led to the Digital Economy Programme. The Digital Economy is an RCUK Cross-Research Council Programme, led by the EPSRC, but working closely with ESRC, MRC, AHRC and TSB. What is Digital Economy? Digital Economy is the novel design or use of information and communication technology to help transform the lives of individuals, society or business. All Digital Economy research involves the user community. This can include industry, government, society, charities or other groups as applicable. The research will understand the technologies and also why change is needed, what the impacts will be and who will benefit. Research in this cross-research council area can be driven by economic, social or technical need. The early involvement of the user community is vital if new technologies are to be integrated successfully into business opportunities, technical solutions or commercial products and processes. Challenges in the Digital Economy will require multi-disciplinary academic input, including, but not limited to, the arts and humanities, economic and social sciences and medical sciences, in addition to engineering and physical sciences.

  18. Microcontroller-driven fluid-injection system for atomic force microscopy. (United States)

    Kasas, S; Alonso, L; Jacquet, P; Adamcik, J; Haeberli, C; Dietler, G


    We present a programmable microcontroller-driven injection system for the exchange of imaging medium during atomic force microscopy. Using this low-noise system, high-resolution imaging can be performed during this process of injection without disturbance. This latter circumstance was exemplified by the online imaging of conformational changes in DNA molecules during the injection of anticancer drug into the fluid chamber.

  19. Eco-Driven Chemical Research in the Boundary between Academia and Industry (United States)

    Sjöström, Jesper


    This paper examines and discusses the views on science and society held among PhD students working in two different industrially and environmentally driven research programmes in the broad area of green chemistry. It is based on thirteen in-depth interviews. The analysis shows three main ways of handling the situation as "post-academic"…

  20. Covert underwater acoustic communications. (United States)

    Ling, Jun; He, Hao; Li, Jian; Roberts, William; Stoica, Petre


    Low probability of detection (LPD) communications are conducted at a low received signal-to-noise ratio (SNR) to deter eavesdroppers to sense the presence of the transmitted signal. Successful detection at intended receiver heavily relies on the processing gain achieved by employing the direct-sequence spread-spectrum (DSSS) technique. For scenarios that lack a sufficiently low SNR to maintain LPD, another metric, referred to as low probability of interception (LPI), is of interest to protect the privacy of the transmitted information. If covert communications take place in underwater acoustic (UWA) environments, then additional challenges are present. The time-varying nature of the UWA channel prevents the employment of a long spreading waveform. Furthermore, UWA environments are frequency-selective channels with long memory, which imposes challenges to the design of the spreading waveform. In this paper, a covert UWA communication system that adopts the DSSS technique and a coherent RAKE receiver is investigated. Emphasis is placed on the design of a spreading waveform that not only accounts for the transceiver structure and frequency-selective nature of the UWA channel, but also possesses a superior LPI. The proposed techniques are evaluated using both simulated and SPACE'08 in-water experimental data.

  1. Passive Acoustic Vessel Localization (United States)

    Suwal, Pasang Sherpa

    This thesis investigates the development of a low-cost passive acoustic system for localizing moving vessels to monitor areas where human activities such as fishing, snorkeling and poaching are restricted. The system uses several off-the-shelf sensors with unsynchronized clocks where the Time Difference of Arrival (TDOA) or time delay is extracted by cross-correlation of the signal between paired sensors. The cross-correlation function uses phase correlation or Phase Transform (PHAT) which whitens the cross-spectrum in order to de-emphasize dominant frequency components. Using the locations of pairs of sensors as foci, hyperbolic equations can be defined using the time delay between them. With three or more sensors, multiple hyperbolic functions can be calculated which intersect at a unique point: the boat's location. It is also found that increasing separation distances between sensors decreased the correlation between the signals. However larger separation distances have better localization capability than with small distances. Experimental results from the Columbia and Willamette Rivers are presented to demonstrate performance.

  2. Acoustic Signal Processing (United States)

    Hartmann, William M.; Candy, James V.

    Signal processing refers to the acquisition, storage, display, and generation of signals - also to the extraction of information from signals and the re-encoding of information. As such, signal processing in some form is an essential element in the practice of all aspects of acoustics. Signal processing algorithms enable acousticians to separate signals from noise, to perform automatic speech recognition, or to compress information for more efficient storage or transmission. Signal processing concepts are the building blocks used to construct models of speech and hearing. Now, in the 21st century, all signal processing is effectively digital signal processing. Widespread access to high-speed processing, massive memory, and inexpensive software make signal processing procedures of enormous sophistication and power available to anyone who wants to use them. Because advanced signal processing is now accessible to everybody, there is a need for primers that introduce basic mathematical concepts that underlie the digital algorithms. The present handbook chapter is intended to serve such a purpose.

  3. Collision and recombination driven instabilities in variable charged dusty plasmas

    Indian Academy of Sciences (India)

    S Bal; M Bose


    The dust-acoustic instability driven by recombination of electrons and ions on the surface of charged and variably-charged dust grains as well as by collisions in dusty plasmas with significant pressure of background neutrals have been theoretically investigated. The recombination driven instability is shown to be dominant in the long wavelength regime even in the presence of dust-neutral and ion-neutral collisions, while in the shorter wavelength regime, the dust-neutral collision is found to play a major role. In an earlier research work, the dust-neutral collision was neglected in comparison to the effect due to the recombination for estimating the dust-acoustic instability; later the other report shows that the recombination effect is negligible in the presence of dust-neutral collisions. In line of this present situation our investigation revealed that the recombination is more important than dust-neutral collisions in laboratory plasma and fusion plasma, while the dust-neutral collision frequency is dominant in the interstellar plasmas. The effects of ion and dust densities and ion streaming on the recombination and collision driven mode in parameter regimes relevant for many experimental studies on dusty plasmas have also been calculated.

  4. Focusing of Acoustic Waves through Acoustic Materials with Subwavelength Structures

    KAUST Repository

    Xiao, Bingmu


    In this thesis, wave propagation through acoustic materials with subwavelength slits structures is studied. Guided by the findings, acoustic wave focusing is achieved with a specific material design. By using a parameter retrieving method, an effective medium theory for a slab with periodic subwavelength cut-through slits is successfully derived. The theory is based on eigenfunction solutions to the acoustic wave equation. Numerical simulations are implemented by the finite-difference time-domain (FDTD) method for the two-dimensional acoustic wave equation. The theory provides the effective impedance and refractive index functions for the equivalent medium, which can reproduce the transmission and reflection spectral responses of the original structure. I analytically and numerically investigate both the validity and limitations of the theory, and the influences of material and geometry on the effective spectral responses are studied. Results show that large contrasts in impedance and density are conditions that validate the effective medium theory, and this approximation displays a better accuracy for a thick slab with narrow slits in it. Based on the effective medium theory developed, a design of a at slab with a snake shaped" subwavelength structure is proposed as a means of achieving acoustic focusing. The property of focusing is demonstrated by FDTD simulations. Good agreement is observed between the proposed structure and the equivalent lens pre- dicted by the theory, which leads to robust broadband focusing by a thin at slab.

  5. Acoustic loading effects on oscillating rod bundles

    Energy Technology Data Exchange (ETDEWEB)

    Lin, W.H.


    An analytical study of the interaction between an infinite acoustic medium and a cluster of circular rods is described. The acoustic field due to oscillating rods and the acoustic loading on the rods are first solved in a closed form. The acoustic loading is then used as a forcing function for rod responses, and the acousto-elastic couplings are solved simultaneously. Numerical examples are presented for several cases to illustrate the effects of various system parameters on the acoustic reaction force coefficients. The effect of the acoustic loading on the coupled eigenfrequencies are discussed.

  6. Reflective echo tomographic imaging using acoustic beams

    Energy Technology Data Exchange (ETDEWEB)

    Kisner, Roger; Santos-Villalobos, Hector J


    An inspection system includes a plurality of acoustic beamformers, where each of the plurality of acoustic beamformers including a plurality of acoustic transmitter elements. The system also includes at least one controller configured for causing each of the plurality of acoustic beamformers to generate an acoustic beam directed to a point in a volume of interest during a first time. Based on a reflected wave intensity detected at a plurality of acoustic receiver elements, an image of the volume of interest can be generated.

  7. Modelling of acoustic transmission through perforated layer

    Directory of Open Access Journals (Sweden)

    Lukeš V.


    Full Text Available The paper deals with modeling the acoustic transmission through a perforated interface plane separating two halfspaces occupied by the acoustic medium. We considered the two-scale homogenization limit of the standard acoustic problem imposed in the layer with the perforated periodic structure embedded inside. The homogenized transmission conditions govern the interface discontinuity of the acoustic pressure associated with the two halfspaces and the magnitude of the fictitious transversal acoustic velocity. By numerical examples we illustrate this novel approach of modeling the acoustic impedance of perforated interfaces.

  8. Eesti Ettevõtluse toetamise programm / Indrek Ustav

    Index Scriptorium Estoniae

    Ustav, Indrek, 1973-


    Eesti Ettevõtluse toetamise programm ehk Eesti BAS Programm (Estonian Business Advisory Service Programm) tegutseb Taani, Soome, Rootsi, Norra, Islandi ja EBRD vahelise lepingu alusel Eesti väikese ja keskmise suurusega ettevõtete toetamiseks

  9. The Driven Spinning Top (United States)

    Grosu, Ioan; Featonby, David


    This driven top is quite a novelty and can, with some trials, be made using the principles outlined here. This new top has many applications in developing both understanding and skills and these are detailed in the article. Depending on reader's available time and motivation they may feel an urge to make one themselves, or simply invest a few…

  10. The European Framework Programme under way

    CERN Multimedia


    The new European Framework Programme - FP7 - has recently started and will offer various possibilities for CERN to participate in EU co-funded projects for research and technological development. In December 2006, the Council of the European Union (EU) formally adopted the 7th European Framework Programme for research, technological development and demonstration activities (FP7). FP7 started on 1st January 2007 and will cover the period 2007 to 2013. With a total budget of 50.5 billion euros, FP7 is the largest Framework Programme in the history of the EU. FP7 consists of four major sub-programmes, referred to as 'Specific Programmes'. 'Cooperation' is focused on collaborative research and is divided into 10 research themes. 'Ideas' is a new EU programme for funding frontier research in all fields of science. 'Capacities' aims at strengthening the research capacities in Europe. Finally, 'People' succeeds the previous Marie Curie Programmes and targets the development of Europe's human potential. On 22 Decem...

  11. The European Framework Programme under way

    CERN Multimedia


    The new European Framework Programme - FP7 - has recently started and will offer various possibilities for CERN to participate in EU co-funded projects for research and technological development. In December 2006, the Council of the European Union (EU) formally adopted the 7th European Framework Programme for research, technological development and demonstration activities (FP7). FP7 started on 1 January 2007 and will cover the period 2007 to 2013. With a total budget of 50.5 B-Euros, FP7 is the largest Framework Programme in the history of the EU. FP7 consists of four major sub-programmes, referred to as 'Specific Programmes'. 'Cooperation' is focused on collaborative research and is divided into 10 research themes. 'Ideas' is a new EU programme for funding of frontier research in all fields of science. 'Capacities' aims at strengthening the research capacities in Europe. Finally, 'People' succeeds the previous Marie Curie Programmes and targets the development of Europe's human potential. On 22 December...

  12. National and regional asthma programmes in Europe

    Directory of Open Access Journals (Sweden)

    Olof Selroos


    Full Text Available This review presents seven national asthma programmes to support the European Asthma Research and Innovation Partnership in developing strategies to reduce asthma mortality and morbidity across Europe. From published data it appears that in order to influence asthma care, national/regional asthma programmes are more effective than conventional treatment guidelines. An asthma programme should start with the universal commitments of stakeholders at all levels and the programme has to be endorsed by political and governmental bodies. When the national problems have been identified, the goals of the programme have to be clearly defined with measures to evaluate progress. An action plan has to be developed, including defined re-allocation of patients and existing resources, if necessary, between primary care and specialised healthcare units or hospital centres. Patients should be involved in guided self-management education and structured follow-up in relation to disease severity. The three evaluated programmes show that, thanks to rigorous efforts, it is possible to improve patients' quality of life and reduce hospitalisation, asthma mortality, sick leave and disability pensions. The direct and indirect costs, both for the individual patient and for society, can be significantly reduced. The results can form the basis for development of further programme activities in Europe.

  13. The ATLAS Forward Proton Programme

    CERN Document Server

    Trzebinski, M; The ATLAS collaboration


    The ATLAS Forward Proton Programme - talk for the Low-x 2012 Meeting Quartic anomalous couplings measurement at μ = 46 and a total luminosity of 300 fb−1 is possible. The full AFP simulation in presence of pile-up confirms the gain in sensitivity between one and two orders of magnitude with respect to the standard (non-AFP) ATLAS methods. The use of the AFP allows reaching the values expected in Higgs-less or extra-dimension models. The production of exclusive dijet for μ = 23 and a total luminosity of 40 fb−1 the measurement is possible and interesting due to the huge model uncertainties at present level of the theory understanding. The measurement of the W asymmetry in a specific configuration at low μ allows to get a decisive understanding on the diffractive exchange. For all physics cases, AFP capabilities in terms of proton tagging and timing resolution are key and unique features unprecedented sensitivity to quartic anomalous coupling or novel QCD measurements.


    CERN Multimedia


    LECTURE SERIES 6 & 8 May 2008 11:00 -12:00 – Main Auditorium, bldg. 500-1 Energy isn’t Everything: CERN’s Fixed Target Niche Prof. John DAINTON / Cockcroft Institute & Liverpool University, UK Fixed target physics at CERN remains an essential part of the Laboratory’s scientific programme and horizon. In recent years fixed target and decay physics using CERN’s unique accelerator and beam facilities has continued to enable unique experiments to be undertaken. An overview is presented of the status of this physics and, wherever appropriate, of its future. LECTURE SERIES 7 May 2008 11:00 -12:00 – TH Auditorium – Bldg. 4-3-006 A rich revenue from the use of radioactive beams and radioactive targets: recent highlights from the nTOF and ISOLDE facilities 9 May 2008 11:00 -12:00 – Main Auditorium, bldg. 500-1 The fifth decade of ISOLDE: HIE-ISOLDE Professor Mark HUYSE, Leuven University, BE The On-Line Isotope Mass Separator ISOLDE is a facility dedicated to the production of a...



    Uddin, M. Mosleh; Kabir, M.; Alam, M. Mostafa; Boss, G. K.


    This study describes the Impact of rural maintenance programme on rural markets in Bangladesh. Rural Maintenance programme (RMP) is a year-round programme for maintenance ol 16 miles earthen roads In each selected union. The programme is run by crews consisting of 15 destitute women. The findings suggest that better road maintenance by RMP in the programme areas has resulted in more traffic f low through which the markets in the programme areas have been expanded. Better supply of services su...

  16. Academic Training Lecture Regular Programme

    CERN Multimedia


    AMS_02 Particle Physics Detector Technologies Orbiting the Earth (1/2), by Corrado Gargiulo (CERN).   Thursday, April 19, 2012 from 11:00 to 12:30 (Europe/Zurich) at CERN ( 4-3-006 - TH Conference Room ) AMS-02 has taken the high performance technologies used in particle physics and implemented them for use in low Earth orbit. Safety aspects for the Space Shuttle flight, that carried AMS_02 to the International Space Station, Space environment and inaccessibility during the life of AMS_02 are some of the aspects which have driven the design of the experiment. The technical challenges to build such a detector have been surmounted through the close collaboration amongst the AMS scientists and industries around the world. Their efforts have resulted in the development of new technologies and higher standards of precision.

  17. Evaluating a training programme for executive coaches

    Directory of Open Access Journals (Sweden)

    Karolyne Beets


    Full Text Available Orientation: The evaluation of training programmes provides methodological and logistical challenges to evaluators and human resource (HR managers. The training of executive coaches is no exception in this regard. Research purpose: The study aimed to investigate one particular aspect of the results of an executive coach training programme, and the extent to which knowledge, skills and attitudes acquired during the programme were applied in practical settings.Motivation for the study: Too little is known in South Africa about the effectiveness of training programmes, including executive coach training programmes. There is a need to demonstrate methodological approaches that would provide valid and reliable data.Research design, approach and method: The success case method (SCM was used to guide the study, consisting first of a survey of 80 participants in the training programme, followed by eight interviews to compare successful with less successful cases of skills transfer.Main findings: All six successful coaches were applying the proximal outcomes from the training with good results, with several valuable consequences resulting from the training. Barriers to successful implementation included personal circumstances and unfulfilled expectations of the programme content.Practical/managerial implications: Aspects of the training programme that could be improved included: the buddy selection system, more individualised feedback about self-development, closer supervision, and more support from programme managers.Contribution/value-add: This evaluation contributes to the evaluation literature by providing a documented exploration of a systematic application of the SCM. It also contributes to the coach training literature by providing a systematic evaluation of a coach training intervention in South Africa.

  18. Sonification of acoustic emission data (United States)

    Raith, Manuel; Große, Christian


    While loading different specimens, acoustic emissions appear due to micro crack formation or friction of already existing crack edges. These acoustic emissions can be recorded using suitable ultrasonic transducers and transient recorders. The analysis of acoustic emissions can be used to investigate the mechanical behavior of different specimens under load. Our working group has undertaken several experiments, monitored with acoustic emission techniques. Different materials such as natural stone, concrete, wood, steel, carbon composites and bone were investigated. Also the experimental setup has been varied. Fire-spalling experiments on ultrahigh performance concrete and pullout experiments on bonded anchors have been carried out. Furthermore uniaxial compression tests on natural stone and animal bone had been conducted. The analysis tools include not only the counting of events but the analysis of full waveforms. Powerful localization algorithms and automatic onset picking techniques (based on Akaikes Information Criterion) were established to handle the huge amount of data. Up to several thousand events were recorded during experiments of a few minutes. More sophisticated techniques like moment tensor inversion have been established on this relatively small scale as well. Problems are related to the amount of data but also to signal-to-noise quality, boundary conditions (reflections) sensor characteristics and unknown and changing Greens functions of the media. Some of the acoustic emissions recorded during these experiments had been transferred into audio range. The transformation into the audio range was done using Matlab. It is the aim of the sonification to establish a tool that is on one hand able to help controlling the experiment in-situ and probably adjust the load parameters according to the number and intensity of the acoustic emissions. On the other hand sonification can help to improve the understanding of acoustic emission techniques for training

  19. Acoustic constituents of prosodic typology (United States)

    Komatsu, Masahiko

    Different languages sound different, and considerable part of it derives from the typological difference of prosody. Although such difference is often referred to as lexical accent types (stress accent, pitch accent, and tone; e.g. English, Japanese, and Chinese respectively) and rhythm types (stress-, syllable-, and mora-timed rhythms; e.g. English, Spanish, and Japanese respectively), it is unclear whether these types are determined in terms of acoustic properties, The thesis intends to provide a potential basis for the description of prosody in terms of acoustics. It argues for the hypothesis that the source component of the source-filter model (acoustic features) approximately corresponds to prosody (linguistic features) through several experimental-phonetic studies. The study consists of four parts. (1) Preliminary experiment: Perceptual language identification tests were performed using English and Japanese speech samples whose frequency spectral information (i.e. non-source component) is heavily reduced. The results indicated that humans can discriminate languages with such signals. (2) Discussion on the linguistic information that the source component contains: This part constitutes the foundation of the argument of the thesis. Perception tests of consonants with the source signal indicated that the source component carries the information on broad categories of phonemes that contributes to the creation of rhythm. (3) Acoustic analysis: The speech samples of Chinese, English, Japanese, and Spanish, differing in prosodic types, were analyzed. These languages showed difference in acoustic characteristics of the source component. (4) Perceptual experiment: A language identification test for the above four languages was performed using the source signal with its acoustic features parameterized. It revealed that humans can discriminate prosodic types solely with the source features and that the discrimination is easier as acoustic information increases. The


    Directory of Open Access Journals (Sweden)

    Aleksandr Skvortsov


    Full Text Available The research of influence of life environment adverse factors on physical development and health of population is an actual problem of ecology. The aspects of the most actual problems of the modern world, namely environmental industrial noise pollution are considered in the article. Industrial facilities everywhere have noisy equipment. Noise is a significant factors of negative influenceon people and environment. Combined effects of noise and of other physical pollutions on people may cause amplification of their negative impact. If the noise pollution level from the object in a residential area exceeds the permissible levels (MPL, noise protection measures can be initiated. Today, the most common design decisions for noise protection are sound absorbing construction, noise screens and barriers, acousting housings, soundproff cabins. Many of them are popular, others are less known. The article deals with one of the most wide spread means of noise protection – a portable acoustic screen. The aim of the research is to determine the efficiency of portable acoustic screens. It is shown that the installation of such structures can reduce the average value of the sound level. The authors analyzed acoustic screens as device to reduce noise pollution. The authors offer a potable acoustic screen differing from the used easyness, mobility, minimum price and good sound protective properties. Effectiveness, a sound absorption coefficient and sound conductivity coefficient of a portable acoustic screen are evaluated. The descriptions of the algorithm calculations and the combination of technical solutions have practical originality. The results of the research demonstrate the advantages of the proposed solutions for reducing noise levels in the agro-industrial complex.

  1. The Danish Air Quality Monitoring Programme

    DEFF Research Database (Denmark)

    Kemp, K.; Palmgren, F.

    The Danish Air Quality Monitoring Programme (LMP) was started in 1982 as the first nation-wide urban air pollution monitoring programme in Denmark. The programme has been adjusted to the pollution pattern by two revisions. The present phase (LMP III) was started in 1992. From 2000 a new phase...... concentrations an increase was observed in 1999. This is probably mainly due to the meteorological conditions in 1999. The SO2 concentrations have been continuously decreasing since 1982. In 1999 they were only about 1/10 of the limit values. They are also far below the new values proposed by the EU commission...

  2. Lessons from a microfinance recapitalisation programme. (United States)

    Poston, Angus


    Following a major disaster, microfinance institutions (MFIs) often face high levels of bad debt, which may require the institutions to be recapitalised. This paper describes a recapitalisation programme implemented by the SANASA movement of Sri Lanka in 390 microfinance societies following the December 2004 tsunami, and highlights lessons for other similar programmes. MFI recapitalisation is a good use of funds in post-disaster situations. To create successful programmes, donors should expect to relax some of their usual project requirements and MFIs should focus on maintaining credit discipline.

  3. The Danish Air Quality Monitoring Programme

    DEFF Research Database (Denmark)

    Kemp, K.; Palmgren, F.; Manscher, O. H.

    The Danish Air Quality Monitoring Programme (LMP) was started in 1982 as the first nation-wide urban air pollution monitoring programme in Denmark. The programme has been adjusted to the pollution pattern by two revisions. The present phase (LMP III) was started in 1992. This report presents...... Copenhagen the same program is con-ducted as at the street stations with the inclusion of O3. Only NO, NO2 and O3 are reported from the other rural site. Air quality limit values have been implemented in Den-mark for NO2, SO2, TSP in order to protect human health. All limit values are based on EU limit...

  4. Kohaliku omaalgatuse programm paneb maaelule õla alla / Taavi Tuur

    Index Scriptorium Estoniae

    Tuur, Taavi


    Kohaliku omaalgatuse programm on riigieelarvest rahastatav regionaalse arengu programm, mille eesmärk on kohalik areng ja piirkondade konkurentsivõime suurenemine kogukonna kaasamise ja tugevdamise kaudu

  5. Factors Affecting Detection Probability of Acoustic Tags in Coral Reefs

    KAUST Repository

    Bermudez, Edgar F.


    Acoustic telemetry is an important tool for studying the movement patterns, behaviour, and site fidelity of marine organisms; however, its application is challenged in coral reef environments where complex topography and intense environmental noise interferes with acoustic signals, and there has been less study. Therefore, it is particularly critical in coral reef telemetry studies to first conduct a long-term range test, a tool that provides informa- tion on the variability and periodicity of the transmitter detection range and the detection probability. A one-month range test of a coded telemetric system was conducted prior to a large-scale tagging project investigating the movement of approximately 400 fishes from 30 species on offshore coral reefs in the central Red Sea. During this range test we determined the effect of the following factors on transmitter detection efficiency: distance from receiver, time of day, depth, wind, current, moon-phase and temperature. The experiment showed that biological noise is likely to be responsible for a diel pattern of -on average- twice as many detections during the day as during the night. Biological noise appears to be the most important noise source in coral reefs overwhelming the effect of wind-driven noise, which is important in other studies. Detection probability is also heavily influenced by the location of the acoustic sensor within the reef structure. Understanding the effect of environmental factors on transmitter detection probability allowed us to design a more effective receiver array for the large-scale tagging study.

  6. Three-Dimensional Phenomena in Microbubble Acoustic Streaming (United States)

    Marin, Alvaro; Rossi, Massimiliano; Rallabandi, Bhargav; Wang, Cheng; Hilgenfeldt, Sascha; Kähler, Christian J.


    Ultrasound-driven oscillating microbubbles are used as active actuators in microfluidic devices to perform manifold tasks such as mixing, sorting, and manipulation of microparticles. A common configuration consists of side bubbles created by trapping air pockets in blind channels perpendicular to the main channel direction. This configuration consists of acoustically excited bubbles with a semicylindrical shape that generate significant streaming flow. Because of the geometry of the channels, such flows are generally considered as quasi-two-dimensional. Similar assumptions are often made in many other microfluidic systems based on flat microchannels. However, in this Letter we show that microparticle trajectories actually present a much richer behavior, with particularly strong out-of-plane dynamics in regions close to the microbubble interface. Using astigmatism particle-tracking velocimetry, we reveal that the apparent planar streamlines are actually projections of a stream surface with a pseudotoroidal shape. We, therefore, show that acoustic streaming cannot generally be assumed as a two-dimensional phenomenon in confined systems. The results have crucial consequences for most of the applications involving acoustic streaming such as particle trapping, sorting, and mixing.

  7. Direct Intracochlear Acoustic Stimulation Using a PZT Microactuator

    Directory of Open Access Journals (Sweden)

    Chuan Luo


    Full Text Available Combined electric and acoustic stimulation has proven to be an effective strategy to improve hearing in some cochlear implant users. We describe an acoustic microactuator to directly deliver stimuli to the perilymph in the scala tympani. The 800 µm by 800 µm actuator has a silicon diaphragm driven by a piezoelectric thin film (e.g., lead-zirconium-titanium oxide or PZT. This device could also be used as a component of a bimodal acoustic-electric electrode array. In the current study, we established a guinea pig model to test the actuator for its ability to deliver auditory signals to the cochlea in vivo. The actuator was placed through the round window of the cochlea. Auditory brainstem response (ABR thresholds, peak latencies, and amplitude growth were calculated for an ear canal speaker versus the intracochlear actuator for tone burst stimuli at 4, 8, 16, and 24 kHz. An ABR was obtained after removal of the probe to assess loss of hearing related to the procedure. In some animals, the temporal bone was harvested for histologic analysis of cochlear damage. We show that the device is capable of stimulating ABRs in vivo with latencies and growth functions comparable to stimulation in the ear canal. Further experiments will be necessary to evaluate the efficiency and safety of this modality in long-term auditory stimulation and its ability to be integrated with conventional cochlear implant arrays.

  8. Virtual acoustic displays (United States)

    Wenzel, Elizabeth M.


    A 3D auditory display can potentially enhance information transfer by combining directional and iconic information in a quite naturalistic representation of dynamic objects in the interface. Another aspect of auditory spatial clues is that, in conjunction with other modalities, it can act as a potentiator of information in the display. For example, visual and auditory cues together can reinforce the information content of the display and provide a greater sense of presence or realism in a manner not readily achievable by either modality alone. This phenomenon will be particularly useful in telepresence applications, such as advanced teleconferencing environments, shared electronic workspaces, and monitoring telerobotic activities in remote or hazardous situations. Thus, the combination of direct spatial cues with good principles of iconic design could provide an extremely powerful and information-rich display which is also quite easy to use. An alternative approach, recently developed at ARC, generates externalized, 3D sound cues over headphones in realtime using digital signal processing. Here, the synthesis technique involves the digital generation of stimuli using Head-Related Transfer Functions (HRTF's) measured in the two ear-canals of individual subjects. Other similar approaches include an analog system developed by Loomis, et. al., (1990) and digital systems which make use of transforms derived from normative mannikins and simulations of room acoustics. Such an interface also requires the careful psychophysical evaluation of listener's ability to accurately localize the virtual or synthetic sound sources. From an applied standpoint, measurement of each potential listener's HRTF's may not be possible in practice. For experienced listeners, localization performance was only slightly degraded compared to a subject's inherent ability. Alternatively, even inexperienced listeners may be able to adapt to a particular set of HRTF's as long as they provide adequate

  9. EMSP Final Report: Electrically Driven Technologies for Radioactive Aerosol Abatement

    Energy Technology Data Exchange (ETDEWEB)

    DePaoli, D.W.


    The purpose of this research project was to develop an improved understanding of how electrically driven processes, including electrocoalescence, acoustic agglomeration, and electric filtration, may be employed to efficiently treat problems caused by the formation of aerosols during DOE waste treatment operations. The production of aerosols during treatment and retrieval operations in radioactive waste tanks and during thermal treatment operations such as calcination presents a significant problem of cost, worker exposure, potential for release, and increased waste volume. There was anecdotal evidence in the literature that acoustic agglomeration and electrical coalescence could be used together to change the size distribution of aerosol particles in such a way as to promote easier filtration and less frequent maintenance of filtration systems. As such, those electrically driven technologies could potentially be used as remote technologies for improved treatment; however, existing theoretical models are not suitable for prediction and design. To investigate the physics of such systems, and also to prototype a system for such processes, a collaborative project was undertaken between Oak Ridge National Laboratory (ORNL) and the University of Texas at Austin (UT). ORNL was responsible for the larger-scale prototyping portion of the project, while UT was primarily responsible for the detailed physics in smaller scale unit reactors. It was found that both electrical coalescence and acoustic agglomeration do in fact increase the rate of aggregation of aerosols. Electrical coalescence requires significantly less input power than acoustic agglomeration, but it is much less effective in its ability to aggregate/coalesce aerosols. The larger-scale prototype showed qualitatively similar results as the unit reactor tests, but presented more difficulty in interpretation of the results because of the complex multi-physics coupling that necessarily occur in all larger

  10. On Architectural Acoustics Design using Computer Simulation

    DEFF Research Database (Denmark)

    Schmidt, Anne Marie Due; Kirkegaard, Poul Henning


    is to investigate the field of application an acoustic simulation program can have during an architectural acoustics design process. A case study is carried out in order to represent the iterative working process of an architect. The working process is divided into five phases and represented by typical results......The acoustical quality of a given building, or space within the building, is highly dependent on the architectural design. Architectural acoustics design has in the past been based on simple design rules. However, with a growing complexity in the architectural acoustic and the emergence of potent...... room acoustic simulation programs it is now possible to subjectively analyze and evaluate acoustic properties prior to the actual construction of a facility. With the right tools applied, the acoustic design can become an integrated part of the architectural design process. The aim of the present paper...

  11. Acoustic remote sensing of ocean flows

    Digital Repository Service at National Institute of Oceanography (India)

    Joseph, A.; Desa, E.

    Acoustic techniques have become powerful tools for measurement of ocean circulation mainly because of the ability of acoustic signals to travel long distances in water, and the inherently non-invasive nature of measurement. The satellite remote...

  12. Golden Gate and Pt. Reyes Acoustic Detections (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains detections of acoustic tagged fish from two general locations: Golden Gate (east and west line) and Pt. Reyes. Several Vemco 69khz acoustic...

  13. Acoustic network event classification using swarm optimization (United States)

    Burman, Jerry


    Classifying acoustic signals detected by distributed sensor networks is a difficult problem due to the wide variations that can occur in the transmission of terrestrial, subterranean, seismic and aerial events. An acoustic event classifier was developed that uses particle swarm optimization to perform a flexible time correlation of a sensed acoustic signature to reference data. In order to mitigate the effects from interference such as multipath, the classifier fuses signatures from multiple sensors to form a composite sensed acoustic signature and then automatically matches the composite signature with reference data. The approach can classify all types of acoustic events but is particularly well suited to explosive events such as gun shots, mortar blasts and improvised explosive devices that produce an acoustic signature having a shock wave component that is aperiodic and non-linear. The classifier was applied to field data and yielded excellent results in terms of reconstructing degraded acoustic signatures from multiple sensors and in classifying disparate acoustic events.

  14. Acoustic Localization with Infrasonic Signals (United States)

    Threatt, Arnesha; Elbing, Brian


    Numerous geophysical and anthropogenic events emit infrasonic frequencies (wind turbines and tornadoes. These sounds, which cannot be heard by the human ear, can be detected from large distances (in excess of 100 miles) due to low frequency acoustic signals having a very low decay rate in the atmosphere. Thus infrasound could be used for long-range, passive monitoring and detection of these events. An array of microphones separated by known distances can be used to locate a given source, which is known as acoustic localization. However, acoustic localization with infrasound is particularly challenging due to contamination from other signals, sensitivity to wind noise and producing a trusted source for system development. The objective of the current work is to create an infrasonic source using a propane torch wand or a subwoofer and locate the source using multiple infrasonic microphones. This presentation will present preliminary results from various microphone configurations used to locate the source.

  15. Classroom acoustics: Three pilot studies (United States)

    Smaldino, Joseph J.


    This paper summarizes three related pilot projects designed to focus on the possible effects of classroom acoustics on fine auditory discrimination as it relates to language acquisition, especially English as a second language. The first study investigated the influence of improving the signal-to-noise ratio on the differentiation of English phonemes. The results showed better differentiation with better signal-to-noise ratio. The second studied speech perception in noise by young adults for whom English was a second language. The outcome indicated that the second language learners required a better signal-to-noise ratio to perform equally to the native language participants. The last study surveyed the acoustic conditions of preschool and day care classrooms, wherein first and second language learning occurs. The survey suggested an unfavorable acoustic environment for language learning.

  16. Acoustic Communication for Medical Nanorobots

    CERN Document Server

    Hogg, Tad


    Communication among microscopic robots (nanorobots) can coordinate their activities for biomedical tasks. The feasibility of in vivo ultrasonic communication is evaluated for micron-size robots broadcasting into various types of tissues. Frequencies between 10MHz and 300MHz give the best tradeoff between efficient acoustic generation and attenuation for communication over distances of about 100 microns. Based on these results, we find power available from ambient oxygen and glucose in the bloodstream can readily support communication rates up to 10,000 bits/second between micron-sized robots. We discuss techniques, such as directional acoustic beams, that can increase this rate. The acoustic pressure fields enabling this communication are unlikely to damage nearby tissue, and short bursts at considerably higher power could be of therapeutic use.

  17. Acoustic multivariate condition monitoring - AMCM

    Energy Technology Data Exchange (ETDEWEB)

    Rosenhave, P.E. [Vestfold College, Maritime Dept., Toensberg (Norway)


    In Norway, Vestfold College, Maritime Department presents new opportunities for non-invasive, on- or off-line acoustic monitoring of rotating machinery such as off-shore pumps and diesel engines. New developments within acoustic sensor technology coupled with chemometric data analysis of complex signals now allow condition monitoring of hitherto unavailable flexibility and diagnostic specificity. Chemometrics paired with existing knowledge yields a new and powerful tool for condition monitoring. By the use of multivariate techniques and acoustics it is possible to quantify wear and tear as well as predict the performance of working components in complex machinery. This presentation describes the AMCM method and one result of a feasibility study conducted onboard the LPG/C `Norgas Mariner` owned by Norwegian Gas Carriers as (NGC), Oslo. (orig.) 6 refs.

  18. Particle analysis in an acoustic cytometer

    Energy Technology Data Exchange (ETDEWEB)

    Kaduchak, Gregory; Ward, Michael D


    The present invention is a method and apparatus for acoustically manipulating one or more particles. Acoustically manipulated particles may be separated by size. The particles may be flowed in a flow stream and acoustic radiation pressure, which may be radial, may be applied to the flow stream. This application of acoustic radiation pressure may separate the particles. In one embodiment, the particles may be separated by size, and as a further example, the larger particles may be transported to a central axis.

  19. Absorption boundary conditions for geomertical acoustics

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho


    Defining accurate acoustical boundary conditions is of crucial importance for room acoustic simulations. In predicting sound fields using phased geometrical acoustics methods, the absorption coefficients or surface impedances of the boundary surfaces can be used, but no guideline has been developed...... solutions. Two rectangular rooms with uniform and non-uniform absorption distributions are tested. It is concluded that the impedance and random incidence absorption boundary conditions produce reasonable results with some exceptions at low frequencies for acoustically soft materials....

  20. France: the programme of festivities is unveiled

    CERN Document Server


    The programme of events to be held in the local French area in honour of CERN's fiftieth anniversary was unveiled in the CMS hall on 26 April at a ceremony attended by many local authority representatives.

  1. Establishing a national universal vaccination programme. (United States)

    Duma, R


    The collaborative efforts of healthcare providers, governmental policy and law makers and the public are often needed to provide the pressure necessary to establish a national universal vaccination programme. Key initiatives for those beginning to establish such a programme are the following: secure a scientific consensus or base of support; clarify relevance of the subject to all concerned; increase awareness of everyone (providers and consumers); recruit and involve influential people (angels) for support; seek out agendas within which to review the topic; generate cost-benefit data; encourage a consensus to be reached; identify legislative pathways to be used; convince politicians of the value of such a programme; request budgeting and funding; and, finally, follow up with surveillance studies to demonstrate the benefits of the programme.

  2. Questions over alternatives to detention programmes

    Directory of Open Access Journals (Sweden)

    Stephanie J Silverman


    Full Text Available Alternative to detention programmes may be less restrictive and less expensive than formal detention but they may still have drawbacks. The provision of competent legal advice appears to be key to low rates of absconding.

  3. The CERN & Society programme launches its newsletter

    CERN Multimedia

    Matteo Castoldi


    The newsletter will be issued quarterly. Sign up to remain informed about the latest initiatives of the CERN & Society programme!    The CERN & Society programme encompasses projects in the areas of education and outreach, innovation and knowledge exchange, and culture and creativity that spread the CERN spirit of scientific curiosity for the inspiration and benefit of society. The programme is funded primarily by the CERN & Society Foundation, a charitable foundation established by CERN and supported by individuals, trusts, organisations and commercial companies. The projects are inspired or enabled by CERN but lie outside of the Laboratory’s specific research mandate. We especially want to help young talent from around the world to flourish in the future. The programme is now launching its newsletter, which will be issued quarterly. Everybody who wants to be informed about CERN & Society’s activities, stay up-to-date with its latest in...

  4. Indian programme on radioactive waste management

    Indian Academy of Sciences (India)

    P K Wattal


    The primary objective of radioactive waste management is protection of human health, environment and future generation. This article describes, briefly, the Indian programme on management of different radioactive wastes arising in the entire nuclear fuel cycle adhering to this objective.

  5. Control programme for cystic echinococcosis in Uruguay. (United States)

    Irabedra, Pilar; Ferreira, Ciro; Sayes, Julio; Elola, Susana; Rodríguez, Miriam; Morel, Noelia; Segura, Sebastian; Santos, Estela Dos; Guisantes, Jorge A


    Cystic echinococcosis is a highly endemic parasitic zoonosis that is present in the Southern Cone countries of America. For several decades, various prevention and control programmes have been implemented in different countries and regions, with varying results. In Uruguay, a new control programme was implemented in 2006 that employed new strategies for canine diagnosis and treatment, dog population control, diagnosis in humans, epidemiological surveillance, and health education, including community participation. The control programme in Uruguay addresses the control and surveillance of the disease from a holistic perspective based on Primary Health Care, which has strengthened the community's participation in developing and coordinating activities in an interdisciplinary manner. Similarly, the control programme that is currently implemented is based on a risk-focused approach. The surveillance and control measures were focused on small villages and extremely poor urban areas. In this study, the strategies used and the results obtained from 2008-2013 are analysed and discussed.

  6. Control programme for cystic echinococcosis in Uruguay (United States)

    Irabedra, Pilar; Ferreira, Ciro; Sayes, Julio; Elola, Susana; Rodríguez, Miriam; Morel, Noelia; Segura, Sebastian; dos Santos, Estela; Guisantes, Jorge A


    Cystic echinococcosis is a highly endemic parasitic zoonosis that is present in the Southern Cone countries of America. For several decades, various prevention and control programmes have been implemented in different countries and regions, with varying results. In Uruguay, a new control programme was implemented in 2006 that employed new strategies for canine diagnosis and treatment, dog population control, diagnosis in humans, epidemiological surveillance, and health education, including community participation. The control programme in Uruguay addresses the control and surveillance of the disease from a holistic perspective based on Primary Health Care, which has strengthened the community’s participation in developing and coordinating activities in an interdisciplinary manner. Similarly, the control programme that is currently implemented is based on a risk-focused approach. The surveillance and control measures were focused on small villages and extremely poor urban areas. In this study, the strategies used and the results obtained from 2008-2013 are analysed and discussed. PMID:27223652

  7. The UNESCO Bioethics Programme: a review. (United States)

    Langlois, Adéle


    UNESCO's Bioethics Programme was established in 1993. In twenty years it has adopted three international declarations, on the human genome (1997), human genetic data (2003) and bioethics (2005); produced reports on a wide range of bioethics issues; and developed capacity building and public education programmes in bioethics. Yet UNESCO has sometimes struggled to assert its authority in the wider bioethics world. Some bioethicists have criticized the 2005 declaration and suggested that the World Health Organization might be better placed to advance bioethics. In 2011, after four years of debate, UNESCO decided not to draft a convention on human reproductive cloning, because consensus on the issue proved impossible. This article reviews the standard setting and capacity building activities of the UNESCO Bioethics Programme. While the Programme faces challenges common to most intergovernmental organizations, its achievements in expanding international law and building bioethics capacity should not be underestimated.

  8. Control programme for cystic echinococcosis in Uruguay

    Directory of Open Access Journals (Sweden)

    Pilar Irabedra


    Full Text Available Cystic echinococcosis is a highly endemic parasitic zoonosis that is present in the Southern Cone countries of America. For several decades, various prevention and control programmes have been implemented in different countries and regions, with varying results. In Uruguay, a new control programme was implemented in 2006 that employed new strategies for canine diagnosis and treatment, dog population control, diagnosis in humans, epidemiological surveillance, and health education, including community participation. The control programme in Uruguay addresses the control and surveillance of the disease from a holistic perspective based on Primary Health Care, which has strengthened the community’s participation in developing and coordinating activities in an interdisciplinary manner. Similarly, the control programme that is currently implemented is based on a risk-focused approach. The surveillance and control measures were focused on small villages and extremely poor urban areas. In this study, the strategies used and the results obtained from 2008-2013 are analysed and discussed.

  9. Evaluation of a nurse leadership development programme. (United States)

    West, Margaret; Smithgall, Lisa; Rosler, Greta; Winn, Erin


    The challenge for nursing leaders responsible for workforce planning is to predict the knowledge, skills and abilities required to lead future healthcare delivery systems effectively. Succession planning requires a constant, competitive pool of qualified nursing leader candidates, and retention of those interested in career growth. Formal nursing leadership education in the United States is available through graduate education and professional nursing organisation programmes, such as the Emerging Nurse Leader Institute of the American Organization of Nurse Executives. However, there is also a need for local development programmes tailored to the needs of individual organisations. Leaders at Geisinger Health System, one of the largest rural health systems in the US, identified the need for an internal professional development scheme for nurses. In 2013 the Nurses Emerging as Leaders programme was developed to prepare nurse leaders for effective leadership and successful role transition. This article describes the programme and an evaluation of its effectiveness.

  10. General outline of scientific programme for 1971

    CERN Multimedia


    A description of the 1971 scientific and technical programme at CERN was prepared for the Scientific Policy Committee and was used to accompany the budget document. The opening chapter is reproduced here with a few minor modifications.

  11. Acoustic behaviors of unsaturated soils (United States)

    Lu, Z.


    Soils are unconsolidated granular materials, consisting of solid particles, water and air. Their mechanical and dynamic behaviors are determined by the discrete nature of the media as well as external and inter-particle forces. For unsaturated soils, two factors significantly affect soils acoustic/seismic responses: external pressure and internal water potential/matric suction. In triaxial cell tests, unsaturated soils were subjected to predefined stress paths to undergo stages of normal consolidation, unload-reload cycles, and failure. The stress deformation curve and stress-P-wave velocity were measured and compared. The study revealed that soil's dynamic response to external pressure are similar to those of the load-deformation behaviors and demonstrated that acoustic velocity can be used to monitor the state of stress of soils. In a long term field soil survey, the P-wave velocities were found to be correlated with water potential as expressed as a power-law relationship. The above phenomena can be understood by using the Terzaghi' s the principle of effective stress. The measured results were in good agreement with Brutsaert theory. The effective stress concept can also be applied to explain the observations in a soil pipe flow study in which soil internal erosion processes were monitored and interpreted by the temporal evolution of the P-wave velocity. In addition to above linear acoustic behaviors, soils, like other earth materials, exhibit astonishing non-classical nonlinear behaviors such as end-point memory, hysteresis, strain -dependent shear modulus, resonant frequency shift, and phase shift, harmonics generation, etc. A nonlinear acoustic study of a soil as a function of water content showed that the nonlinear acoustic parameter are much sensitive to the variations of soil water content than that of the acoustic velocity.

  12. CT findings of acoustic neuroma

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Do Choul; Lee, Jae Mun; Shinn, Kyung Sub; Bahk, Yong Whee [Catholic Univ., Seoul (Korea, Republic of)


    Computed Tomography (CT) is very accurate in evaluating the location, size, shape and extension of acoustic neuroma. We analysed CT findings of 23 acoustic neuromas seen at Department of Radiology, Kangnam St. Mary's Hospital, Catholic University Medical College during the period of from January 1981 to June 1987. 1. Five (22%) were men and 18 (78%) were women with the high incidence occurring in the 4th and 5th decades. 2. Twenty two cases were diagnosed satisfactorily by CT examinations which included axial, coronal and reconstruction images. One with the smallest dimension of 8 mm in diameter could not be detected by the conventional CT scan. But is could be seen after metrizamide cisternography. mean size of the tumor masses was estimated 3.6 cm in diameter. 3. The shape of the tumor was oval in 50%, round in 27% and lobulated in 23%. The masses were presented as hypodense in 50%, isodense in 32% and hyperdense in 18%. All tumors were extended from the internal acoustic and toward the cerebellopontine angle. The internal acoustic canal was widened in 77%. Hydrocephalus was associated in 45%. Widening of cerebellopontine angle cistern was noted in 50%. 4. After contrast infusion the tumors were enhanced markedly in 45%, moderately in 32% and mildly in 23%. The enhanced pattern was homogeneous in 41%, mixed in 41% and rim in 18%. The margin of the tumors was sharply defined in 82%. The tumors were attached to the petrous bone with acute angle in 73%. Cystic change within the tumor was found in 27%. The peritumoral edema was noted in 45%. In conclusion, CT is of most effective modalities to evaluate size, shape, extent and internal architecture of acoustic neuroma as well as relationship with adjacent anatomic structures including the internal acoustic canal.

  13. Acoustically-Induced Electrical Signals (United States)

    Brown, S. R.


    We have observed electrical signals excited by and moving along with an acoustic pulse propagating in a sandstone sample. Using resonance we are now studying the characteristics of this acousto-electric signal and determining its origin and the controlling physical parameters. Four rock samples with a range of porosities, permeabilities, and mineralogies were chosen: Berea, Boise, and Colton sandstones and Austin Chalk. Pore water salinity was varied from deionized water to sea water. Ag-AgCl electrodes were attached to the sample and were interfaced to a 4-wire electrical resistivity system. Under computer control, the acoustic signals were excited and the electrical response was recorded. We see strong acoustically-induced electrical signals in all samples, with the magnitude of the effect for each rock getting stronger as we move from the 1st to the 3rd harmonics in resonance. Given a particular fluid salinity, each rock has its own distinct sensitivity in the induced electrical effect. For example at the 2nd harmonic, Berea Sandstone produces the largest electrical signal per acoustic power input even though Austin Chalk and Boise Sandstone tend to resonate with much larger amplitudes at the same harmonic. Two effects are potentially responsible for this acoustically-induced electrical response: one the co-seismic seismo-electric effect and the other a strain-induced resistivity change known as the acousto-electric effect. We have designed experimental tests to separate these mechanisms. The tests show that the seismo-electric effect is dominant in our studies. We note that these experiments are in a fluid viscosity dominated seismo-electric regime, leading to a simple interpretation of the signals where the electric potential developed is proportional to the local acceleration of the rock. Toward a test of this theory we have measured the local time-varying acoustic strain in our samples using a laser vibrometer.

  14. Microcontroller-based underwater acoustic ECG telemetry system. (United States)

    Istepanian, R S; Woodward, B


    This paper presents a microcontroller-based underwater acoustic telemetry system for digital transmission of the electrocardiogram (ECG). The system is designed for the real time, through-water transmission of data representing any parameter, and it was used initially for transmitting in multiplexed format the heart rate, breathing rate and depth of a diver using self-contained underwater breathing apparatus (SCUBA). Here, it is used to monitor cardiovascular reflexes during diving and swimming. The programmable capability of the system provides an effective solution to the problem of transmitting data in the presence of multipath interference. An important feature of the paper is a comparative performance analysis of two encoding methods, Pulse Code Modulation (PCM) and Pulse Position Modulation (PPM).

  15. Acoustic Test Characterization of Melamine Foam for Usage in NASA's Payload Fairing Acoustic Attenuation Systems (United States)

    Hughes, William O.; McNelis, Anne M.; McNelis, Mark E.


    The external acoustic liftoff levels predicted for NASA's future heavy lift launch vehicles are expected to be significantly higher than the environment created by today's commercial launch vehicles. This creates a need to develop an improved acoustic attenuation system for future NASA payload fairings. NASA Glenn Research Center initiated an acoustic test series to characterize the acoustic performance of melamine foam, with and without various acoustic enhancements. This testing was denoted as NEMFAT, which stands for NESC Enhanced Melamine Foam Acoustic Test, and is the subject of this paper. Both absorption and transmission loss testing of numerous foam configurations were performed at the Riverbank Acoustical Laboratory in July 2013. The NEMFAT test data provides an initial acoustic characterization and database of melamine foam for NASA. Because of its acoustic performance and lighter mass relative to fiberglass blankets, melamine foam is being strongly considered for use in the acoustic attenuation systems of NASA's future launch vehicles.

  16. The Norwegian research programme on advanced robotic systems

    Directory of Open Access Journals (Sweden)

    Olav Egeland


    Full Text Available The Norwegian research programme on advanced robot systems has been focused on sensory control of robots for industrial applications and telerobotics for underwater operations. This paper gives an overview of experimental work and ongoing research. An exciting area in sensory control is visual servoing where camera images at video rate are used to grasp moving objects. Also compliant motion in partially unknown environments is a research topic. New robot control systems have been developed to apply sensory control to robotic manipulators at an acceptable sampling rate. In telerobotics the main work has been on the combination of remote control and local sensory loops in the manipulator. Also in this case visual servoing anti force control are important. The generation and updating of a world model used in a graphic display of the worksite using sensory information has been tested in combination with large delay times in the communication channel. The use of visual and acoustic data for the control of remotely operated vehicles and autonomous underwater vehicles is studied for use in robotic systems. Light-weight robot manipulators with redundant degrees of freedom and high performance joints are being designed for mobile robot applications.

  17. Electrically driven optical antennas (United States)

    Kern, Johannes; Kullock, René; Prangsma, Jord; Emmerling, Monika; Kamp, Martin; Hecht, Bert


    Unlike radiowave antennas, so far optical nanoantennas cannot be fed by electrical generators. Instead, they are driven by light or indirectly via excited discrete states in active materials in their vicinity. Here we demonstrate the direct electrical driving of an in-plane optical antenna by the broadband quantum-shot noise of electrons tunnelling across its feed gap. The spectrum of the emitted photons is determined by the antenna geometry and can be tuned via the applied voltage. Moreover, the direction and polarization of the light emission are controlled by the antenna resonance, which also improves the external quantum efficiency by up to two orders of magnitude. The one-material planar design offers facile integration of electrical and optical circuits and thus represents a new paradigm for interfacing electrons and photons at the nanometre scale, for example for on-chip wireless communication and highly configurable electrically driven subwavelength photon sources.

  18. Physical foundations of technical acoustics

    CERN Document Server

    Malecki, I


    Physical Foundations of Technical Acoustics discusses theoretical foundations of acoustical engineering. It is not so much a technical compendium as a systematic statement of physical laws so conceived that technologists might find in it all the information they need to become acquainted with the physical meaning and mathematical expression of phenomena they encounter in their work. To facilitate the acquirement of notions, which lie beyond a layman's grasp, the plan of narration adopted consists in beginning with the simplest idealized cases and then gradually moving on to the truest possibl

  19. Oscillating nonlinear acoustic shock waves

    DEFF Research Database (Denmark)

    Gaididei, Yuri; Rasmussen, Anders Rønne; Christiansen, Peter Leth


    We investigate oscillating shock waves in a tube using a higher order weakly nonlinear acoustic model. The model includes thermoviscous effects and is non isentropic. The oscillating shock waves are generated at one end of the tube by a sinusoidal driver. Numerical simulations show that at resona......We investigate oscillating shock waves in a tube using a higher order weakly nonlinear acoustic model. The model includes thermoviscous effects and is non isentropic. The oscillating shock waves are generated at one end of the tube by a sinusoidal driver. Numerical simulations show...

  20. Requirements for laboratory animals in health programmes*


    Held, J. R.


    Laboratory animals are essential for the successful execution of many health programmes. A wide variety of animal models is used in the worldwide efforts to improve the control of various diseases, and in the basic research needed to improve health care. Biomedical programmes require specially-bred animals reared under controlled conditions, with close attention given to such factors as physical environment, nutrition, microbiological status, and genetic background. The need for a regular sup...

  1. National programme for prevention of burn injuries

    Directory of Open Access Journals (Sweden)

    Gupta J


    Full Text Available The estimated annual burn incidence in India is approximately 6-7 million per year. The high incidence is attributed to illiteracy, poverty and low level safety consciousness in the population. The situation becomes further grim due to the absence of organized burn care at primary and secondary health care level. But the silver lining is that 90% of burn injuries are preventable. An initiative at national level is need of the hour to reduce incidence so as to galvanize the available resources for more effective and standardized treatment delivery. The National Programme for Prevention of Burn Injuries is the endeavor in this line. The goal of National programme for prevention of burn injuries (NPPBI would be to ensure prevention and capacity building of infrastructure and manpower at all levels of health care delivery system in order to reduce incidence, provide timely and adequate treatment to burn patients to reduce mortality, complications and provide effective rehabilitation to the survivors. Another objective of the programme will be to establish a central burn registry. The programme will be launched in the current Five Year Plan in Medical colleges and their adjoining district hospitals in few states. Subsequently, in the next five year plan it will be rolled out in all the medical colleges and districts hospitals of the country so that burn care is provided as close to the site of accident as possible and patients need not to travel to big cities for burn care. The programme would essentially have three components i.e. Preventive programme, Burn injury management programme and Burn injury rehabilitation programme.

  2. Debriefing Note Secondary Education Support Programme

    DEFF Research Database (Denmark)

    Webster, Neil; Vagnby, Bo Hellisen; Thomsen, Thomas J.

    Debriefing note regarding joint programming for the Secondary Education Support Programme (2003- 2007). The note specifies preparation of SIP Physical Guidelines; Training needs assessment for Physical School Status and Rapid Technical Assessments; SIP/DEP preparation; Selection criteria for dist......Debriefing note regarding joint programming for the Secondary Education Support Programme (2003- 2007). The note specifies preparation of SIP Physical Guidelines; Training needs assessment for Physical School Status and Rapid Technical Assessments; SIP/DEP preparation; Selection criteria...

  3. Benchmarking Danish Vocational Education and Training Programmes

    DEFF Research Database (Denmark)

    Bogetoft, Peter; Wittrup, Jesper

    This study paper discusses methods whereby Danish vocational education and training colleges can be benchmarked, and presents results from a number of models. It is conceptually complicated to benchmark vocational colleges, as the various colleges in Denmark offer a wide range of course programmes...... attempt to summarise the various effects that the colleges have in two relevant figures, namely retention rates of students and employment rates among students who have completed training programmes....

  4. The EC-ASEAN COGEN programme

    Energy Technology Data Exchange (ETDEWEB)

    Pennington, M.; Lacrosse, L. [Asian Institute of Technology (Thailand); Schenkel, Y. [Centre de Recherches Agronomiques (Belgium)


    The EC-ASEAN COGEN Programme is a co-operation programme between the European Commission (EC) and the Association of South East Asian Nations (ASEAN) co-ordinated by the Asian Institute of Technology (AIT), Bangkok, Thailand. Its aim is to accelerate the implementation of proven technologies generating heat and/or power from wood and agroindustrial residues through partnerships between European and ASEAN companies. (orig.)

  5. Acoustic waveform of continuous bubbling in a non-Newtonian fluid. (United States)

    Vidal, Valérie; Ichihara, Mie; Ripepe, Maurizio; Kurita, Kei


    We study experimentally the acoustic signal associated with a continuous bubble bursting at the free surface of a non-Newtonian fluid. Due to the fluid rheological properties, the bubble shape is elongated, and, when bursting at the free surface, acts as a resonator. For a given fluid concentration, at constant flow rate, repetitive bubble bursting occurs at the surface. We report a modulation pattern of the acoustic waveform through time. Moreover, we point out the existence of a precursor acoustic signal, recorded on the microphone array, previous to each bursting. The time delay between this precursor and the bursting signal is well correlated with the bursting signal frequency content. Their joint modulation through time is driven by the fluid rheology, which strongly depends on the presence of small satellite bubbles trapped in the fluid due to the yield stress.

  6. Probing thermomechanics at the nanoscale: impulsively excited pseudosurface acoustic waves in hypersonic phononic crystals. (United States)

    Nardi, Damiano; Travagliati, Marco; Siemens, Mark E; Li, Qing; Murnane, Margaret M; Kapteyn, Henry C; Ferrini, Gabriele; Parmigiani, Fulvio; Banfi, Francesco


    High-frequency surface acoustic waves can be generated by ultrafast laser excitation of nanoscale patterned surfaces. Here we study this phenomenon in the hypersonic frequency limit. By modeling the thermomechanics from first-principles, we calculate the system's initial heat-driven impulsive response and follow its time evolution. A scheme is introduced to quantitatively access frequencies and lifetimes of the composite system's excited eigenmodes. A spectral decomposition of the calculated response on the eigemodes of the system reveals asymmetric resonances that result from the coupling between surface and bulk acoustic modes. This finding allows evaluation of impulsively excited pseudosurface acoustic wave frequencies and lifetimes and expands our understanding of the scattering of surface waves in mesoscale metamaterials. The model is successfully benchmarked against time-resolved optical diffraction measurements performed on one-dimensional and two-dimensional surface phononic crystals, probed using light at extreme ultraviolet and near-infrared wavelengths.

  7. Affinity driven social networks (United States)

    Ruyú, B.; Kuperman, M. N.


    In this work we present a model for evolving networks, where the driven force is related to the social affinity between individuals of a population. In the model, a set of individuals initially arranged on a regular ordered network and thus linked with their closest neighbors are allowed to rearrange their connections according to a dynamics closely related to that of the stable marriage problem. We show that the behavior of some topological properties of the resulting networks follows a non trivial pattern.

  8. Location of an acoustic window in dolphins. (United States)

    Popov, V V; Supin, A Y


    Auditory brainstem responses (ABR) to sound clicks from sources in different positions were recorded in dolphins Inia geoffrensis. The position of the acoustic window was determined by measurement of acoustic delays. The acoustic window was found to lie close to the auditory meatus and the bulla rather than on the lower jaw.

  9. Predicting and auralizing acoustics in classrooms

    DEFF Research Database (Denmark)

    Christensen, Claus Lynge


    Although classrooms have fairly simple geometries, this type of room is known to cause problems when trying to predict their acoustics using room acoustics computer modeling. Some typical features from a room acoustics point of view are: Parallel walls, low ceilings (the rooms are flat), uneven...

  10. Outdoor Acoustics as a General Discipline

    DEFF Research Database (Denmark)

    Rasmussen, Karsten Bo


    A tutorial paper exploring the characteristics of sound outdoors. Outdoor acoustics is contrasted to room acoustics. A number of important aspects of outdoor acoustics are exemplified and theoretical approaches are outlined. These are influence of ground impedance, influence of weather, screening...

  11. Aero-acoustic Computations of Wind Turbines

    DEFF Research Database (Denmark)

    Shen, Wen Zhong; Michelsen, Jess; Sørensen, Jens Nørkær


    A numerical algorithm for acoustic noise generation is extended to 3D flows. The approach involves two parts comprising a viscous incompressible flow part and an inviscid acoustic part. In order to simulate noise generated from a wind turbine, the incompressible and acoustic equations are written...

  12. Effect of temperature programmes on protein crystallisation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xi-Kai; Yin, Da-Chuan; Zhang, Chen-Yan; Lu, Qin-Qin; Guo, Yun-Zhu; Guo, Wei-Hong [Key Laboratory for Space Bioscience and Biotechnology, Faculty of Life Sciences, Northwestern Polytechnical University, Shaanxi (China)


    Varying the temperature has been proven to be beneficial for improving the screening efficiency of protein crystallisation, and thus a crystallisation screening strategy based on this phenomenon can be developed. Such a temperature varying strategy can be applied in practical crystallisation screening, however, there are no guidelines for determining what temperature programme should be utilised. It is therefore necessary to investigate how the temperature programme affects the crystallisation process, so as to help people design a suitable temperature programme. For this purpose, we investigated the effect of temperature programmes on the protein crystallisation (lysozyme, proteinase K, and concanavalin A) that are characterised by different solubility behaviours with respect to temperature. Judging from the reproducibility studies of protein crystallisation with different temperature programmes, we recommend using linear temperature programmes for a moderate time period (24 to 48 h) and a large temperature range according to the properties of the proteins. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Cost-effectiveness of energy efficiency programmes. Evaluating the impacts of a regional programme in France

    Energy Technology Data Exchange (ETDEWEB)

    Suerkemper, F.; Thomas, S. [Wuppertal Institute for Climate, Environment and Energy, Doeppersberg 19, 42103 Wuppertal (Germany); Osso, D. [EDF-R and D, Site des Renardieres-Avenue des Renardieres, Ecuelles, 77818 Moret-sur-Loing cedex (France); Baudry, P. [EDF-R and D, 1, Avenue du General de Gaulle, 92141 Clamart Cedex (France)


    This paper presents the evaluation of a regional energy efficiency programme implemented in two 'departements' of France. Electricite de France (EDF), a French energy company, provides refurbishment advice and financial incentives to end-users in the residential sector as well as specific training courses and certification to local installation contractors and building firms. Refurbishment measures analysed in this paper are efficient space heating equipment (condensing boilers, heat pumps and wood stoves or boilers), solar water heating systems and the installation of double-glazed windows. A billing analysis based on a survey of programme participants' energy consumption is used to calculate the energy savings attributed to the programme. In order to receive an economic feedback of this demonstration programme, the evaluation of both saved energy and programme costs is of importance. Detailed knowledge of the programme's cost-effectiveness is essential for EDF to achieve the saving obligations imposed by the French White Certificate scheme at the lowest cost. Results of this evaluation can support the development and implementation of further energy efficiency programmes with similar characteristics in other regions of France. The cost-effectiveness is determined from the perspective of the programme participant and the society as well as the energy company in charge of the programme. All cost and benefit components are calculated in Euro per kilowatt-hour, which allows a direct comparison of levelized costs of conserved energy with the avoidable costs of the energy supply system.

  14. Coherent coupling between radio frequency, optical, and acoustic waves in piezo-optomechanical circuits. (United States)

    Balram, Krishna C; Davanço, Marcelo I; Song, Jin Dong; Srinivasan, Kartik


    Optomechanical cavities have been studied for applications ranging from sensing to quantum information science. Here, we develop a platform for nanoscale cavity optomechanical circuits in which optomechanical cavities supporting co-localized 1550 nm photons and 2.4 GHz phonons are combined with photonic and phononic waveguides. Working in GaAs facilitates manipulation of the localized mechanical mode either with a radio frequency (RF) field through the piezo-electric effect, which produces acoustic waves that are routed and coupled to the optomechanical cavity by phononic crystal waveguides, or optically through the strong photoelastic effect. Along with mechanical state preparation and sensitive readout, we use this to demonstrate an acoustic wave interference effect, similar to atomic coherent population trapping, in which RF-driven coherent mechanical motion is cancelled by optically-driven motion. Manipulating cavity optomechanical systems with equal facility through both photonic and phononic channels enables new architectures for signal transduction between the optical, electrical, and mechanical domains.

  15. Acoustic and Cavitation Fields of Shock Wave Therapy Devices (United States)

    Chitnis, Parag V.; Cleveland, Robin O.


    Extracorporeal shock wave therapy (ESWT) is considered a viable treatment modality for orthopedic ailments. Despite increasing clinical use, the mechanisms by which ESWT devices generate a therapeutic effect are not yet understood. The mechanistic differences in various devices and their efficacies might be dependent on their acoustic and cavitation outputs. We report acoustic and cavitation measurements of a number of different shock wave therapy devices. Two devices were electrohydraulic: one had a large reflector (HMT Ossatron) and the other was a hand-held source (HMT Evotron); the other device was a pneumatically driven device (EMS Swiss DolorClast Vet). Acoustic measurements were made using a fiber-optic probe hydrophone and a PVDF hydrophone. A dual passive cavitation detection system was used to monitor cavitation activity. Qualitative differences between these devices were also highlighted using a high-speed camera. We found that the Ossatron generated focused shock waves with a peak positive pressure around 40 MPa. The Evotron produced peak positive pressure around 20 MPa, however, its acoustic output appeared to be independent of the power setting of the device. The peak positive pressure from the DolorClast was about 5 MPa without a clear shock front. The DolorClast did not generate a focused acoustic field. Shadowgraph images show that the wave propagating from the DolorClast is planar and not focused in the vicinity of the hand-piece. All three devices produced measurable cavitation with a characteristic time (cavitation inception to bubble collapse) that varied between 95 and 209 μs for the Ossatron, between 59 and 283 μs for the Evotron, and between 195 and 431 μs for the DolorClast. The high-speed camera images show that the cavitation activity for the DolorClast is primarily restricted to the contact surface of the hand-piece. These data indicate that the devices studied here vary in acoustic and cavitation output, which may imply that the

  16. The EuroDIVERSITY Programme: Challenges of Biodiversity Science in Europe (United States)

    Jonckheere, I.


    In close cooperation with its Member Organisations, the European Science Foundation (ESF) has launched since late 2003 a series of European Collaborative Research (EUROCORES) Programmes. Their aim is to enable researchers in different European countries to develop cooperation and scientific synergy in areas where European scale and scope are required in a global context. The EUROCORES instrument represents the first large scale attempt of national research (funding) agencies to act together against fragmentation, asynchronicity and duplication of research (funding) within Europe. Although covering all scientific fields, there are presently 13 EUROCORES Programmes dealing with cutting edge science in the fields of Earth, Climate and Environmental Sciences. The aim of the EuroDIVERSITY Programme is to support the emergence of an integrated biodiversity science based on an understanding of fundamental ecological and social processes that drive biodiversity changes and their impacts on ecosystem functioning and society. Ecological systems across the globe are being threatened or transformed at unprecedented rates from local to global scales due to the ever-increasing human domination of natural ecosystems. In particular, massive biodiversity changes are currently taking place, and this trend is expected to continue over the coming decades, driven by the increasing extension and globalisation of human affairs. The EuroDIVERSITY Programme meets the research need triggered by the increasing human footprint worldwide with a focus on generalisations across particular systems and on the generation and validation of theory relevant to experimental and empirical data. The EURODIVERSITY Programme tries to bridge the gaps between the natural and social sciences, between research work on terrestrial, freshwater and marine ecosystems, and between research work on plants, animals and micro-organisms. The Programme was launched in April 2006 and includes 10 international

  17. Mainstreaming nutrition into maternal and child health programmes: scaling up of exclusive breastfeeding. (United States)

    Bhandari, Nita; Kabir, A K M Iqbal; Salam, Mohammed Abdus


    Interventions to promote exclusive breastfeeding have been estimated to have the potential to prevent 13% of all under-5 deaths in developing countries and are the single most important preventive intervention against child mortality. According to World Health Organization and United Nations Children Funds (UNICEF), only 39% infants are exclusively breastfed for less than 4 months. This review examines programme efforts to scale up exclusive breastfeeding in different countries and draws lesson for successful scale-up. Opportunities and challenges in scaling up of exclusive breastfeeding into Maternal and Child Health programmes are identified. The key processes required for exclusive breastfeeding scale-up are: (1) an evidence-based policy and science-driven technical guidelines; and (2) an implementation strategy and plan for achieving high exclusive breastfeeding rates in all strata of society, on a sustainable basis. Factors related to success include political will, strong advocacy, enabling policies, well-defined short- and long-term programme strategy, sustained financial support, clear definition of roles of multiple stakeholders and emphasis on delivery at the community level. Effective use of antenatal, birth and post-natal contacts at homes and through community mobilization efforts is emphasized. Formative research to ensure appropriate intervention design and delivery is critical particularly in areas with high HIV prevalence. Strong communication strategy and support, quality trainers and training contributed significantly to programme success. Monitoring and evaluation with feedback systems that allow for periodic programme corrections and continued innovation are central to very high coverage. Legal framework must make it possible for mothers to exclusively breastfeed for at least 4 months. Sustained programme efforts are critical to achieve high coverage and this requires strong national- and state-level leadership.

  18. On the Source of Propagating Slow Magneto-acoustic Waves in Sunspots


    S. Krishna Prasad; Jess, D. B.; Khomenko, Elena


    Recent high-resolution observations of sunspot oscillations using simultaneously operated ground- and space-based telescopes reveal the intrinsic connection between different layers of the solar atmosphere. However, it is not clear whether these oscillations are externally driven or generated in-situ. We address this question by using observations of propagating slow magneto-acoustic waves along a coronal fan loop system. In addition to the generally observed decreases in oscillation amplitud...

  19. Breast and cervical cancer screening programme implementation in 16 countries

    DEFF Research Database (Denmark)

    Dowling, Emily C; Klabunde, Carrie; Patnick, Julietta;


    There is a continuing need to monitor and evaluate the impact of organized screening programmes on cancer incidence and mortality. We report results from a programme assessment conducted within the International Cancer Screening Network (ICSN) to understand the characteristics of cervical screening...... programmes within countries that have established population-based breast cancer screening programmes....

  20. 4th Pacific Rim Underwater Acoustics Conference

    CERN Document Server

    Xu, Wen; Cheng, Qianliu; Zhao, Hangfang


    These proceedings are a collection of 16 selected scientific papers and reviews by distinguished international experts that were presented at the 4th Pacific Rim Underwater Acoustics Conference (PRUAC), held in Hangzhou, China in October 2013. The topics discussed at the conference include internal wave observation and prediction; environmental uncertainty and coupling to sound propagation; environmental noise and ocean dynamics; dynamic modeling in acoustic fields; acoustic tomography and ocean parameter estimation; time reversal and matched field processing; underwater acoustic localization and communication as well as measurement instrumentations and platforms. These proceedings provide insights into the latest developments in underwater acoustics, promoting the exchange of ideas for the benefit of future research.

  1. Longitudinal bulk acoustic mass sensor

    DEFF Research Database (Denmark)

    Hales, Jan Harry; Teva, Jordi; Boisen, Anja


    A polycrystalline silicon longitudinal bulk acoustic cantilever is fabricated and operated in air at 51 MHz. A mass sensitivity of 100 Hz/fg (1 fg=10(-15) g) is obtained from the preliminary experiments where a minute mass is deposited on the device by means of focused ion beam. The total noise i...

  2. Acoustics SIMOPS: managing the unnecessary

    Energy Technology Data Exchange (ETDEWEB)

    Hanton, Samuel John [Nautronix Marine Technology Solutions, Rio de Janeiro, RJ (Brazil)


    Time is money, and offshore operations are expensive. The desire therefore, is to increase efficiency through the condensing of schedules. This inevitably leads to SIMOPS of some degree, and this paper discusses SIMOPS along with, more specifically, the challenges they provide to acoustic positioning. (author)

  3. Topology optimization for acoustic problems

    DEFF Research Database (Denmark)

    Dühring, Maria Bayard


    In this paper a method to control acoustic properties in a room with topology optimization is presented. It is shown how the squared sound pressure amplitude in a certain part of a room can be minimized by distribution of material in a design domain along the ceiling in 2D and 3D. Nice 0-1 design...

  4. Acoustic Microscopy at Cryogenic Temperatures. (United States)


    intensities are used, and quantitatitvely acount for the onset of nonlinear excess attenuation. Aooeuuaiol For DTIC TAB Unaranounc ed Just if icat to acoustic power is a reasonable value and can be acounted for by assuming a one-way transducer conversion loss of 5 dB, a lens illumination loss of

  5. APL - North Pacific Acoustic Laboratory (United States)


    the roles of internal waves, ocean spice, internal tides, fronts and eddies in causing fluctuations in acoustic receptions. 5. To improve basin-scale...Farmer, R. Gentry, T. Gross, A. Hawkins, F.~Li, K. Metcalf , J.H. Miller, D. Moretti, C. Rodrigo, and T. Shinke, (2011). “An International Quiet

  6. Acoustic Climb to Cruise Test (United States)


    Flight test film footage of three different aircraft testing the acoustical noise levels during take-off, climb, maneuvers, and touch and go landings are described. These sound tests were conducted on two fighter aircraft and one cargo aircraft. Results from mobile test vehicle are shown.

  7. Acoustic Absorption Characteristics of People. (United States)

    Kingsbury, H. F.; Wallace, W. J.


    The acoustic absorption characteristics of informally dressed college students in typical classroom seating are shown to differ substantially from data for formally dressed audiences in upholstered seating. Absorption data, expressed as sabins per person or absorption coefficient per square foot, shows that there is considerable variation between…

  8. Fundamentals of Acoustic Backscatter Imagery (United States)


    41 6.12 Geocoding ...47 7.6 Errors in Geocoding .............................................................................................................. 47...h = z - R cos6 (39a) and x = rt sin6. (39b) 6.12 Geocoding Acoustic backscatter imagery data are collected by recording the across-track signals

  9. Numerical investigation of acoustic solitons

    CERN Document Server

    Lombard, Bruno; Richoux, Olivier


    Acoustic solitons can be obtained by considering the propagation of large amplitude sound waves across a set of Helmholtz resonators. The model proposed by Sugimoto and his coauthors has been validated experimentally in previous works. Here we examine some of its theoretical properties: low-frequency regime, balance of energy, stability. We propose also numerical experiments illustrating typical features of solitary waves.

  10. Acoustic Liner for Turbomachinery Applications (United States)

    Huff, Dennis L.; Sutliff, Daniel L.; Jones, Michael G.; Hebsur, Mohan G.


    The purpose of this innovation is to reduce aircraft noise in the communities surrounding airports by significantly attenuating the noise generated by the turbomachinery, and enhancing safety by providing a containment barrier for a blade failure. Acoustic liners are used in today's turbofan engines to reduce noise. The amount of noise reduction from an acoustic liner is a function of the treatment area, the liner design, and the material properties, and limited by the constraints of the nacelle or casement design. It is desirable to increase the effective area of the acoustic treatment to increase noise suppression. Modern turbofan engines use wide-chord rotor blades, which means there is considerable treatment area available over the rotor tip. Turbofan engines require containment over the rotors for protection from blade failure. Traditional methods use a material wrap such as Kevlar integrated with rub strips and sometimes metal layers (sandwiches). It is possible to substitute the soft rub-strip material with an open-cell metallic foam that provides noise-reduction benefits and a sacrificial material in the first layer of the containment system. An open-cell foam was evaluated that behaves like a bulk acoustic liner, serves as a tip rub strip, and can be integrated with a rotor containment system. Foams can be integrated with the fan-containment system to provide sufficient safety margins and increased noise attenuation. The major innovation is the integration of the foam with the containment.

  11. MTCI acoustic agglomeration particulate control

    Energy Technology Data Exchange (ETDEWEB)

    Chandran, R.R.; Mansour, M.N. [Manufacturing and Technology Conversion International, Inc., Columbia, MD (United States); Scaroni, A.W.; Koopmann, G.H. [Pennsylvania State Univ., University Park, PA (United States); Loth, J.L. [West Virginia Univ., Morgantown, WV (United States)


    The overall objective of this project is to demonstrate pulse combination induced acoustic enhancement of coal ash agglomeration and sulfur capture at conditions typical of direct coal-fired turbines and PFBC hot gas cleanup. MTCI has developed an advanced compact pulse combustor island for direct coal-firing in combustion gas turbines. This combustor island comprises a coal-fired pulse combustor, a combined ash agglomeration and sulfur capture chamber (CAASCC), and a hot cyclone. In the MTCI proprietary approach, the pulse combustion-induced high intensity sound waves improve sulfur capture efficiency and ash agglomeration. The resulting agglomerates allow the use of commercial cyclones and achieve very high particulate collection efficiency. In the MTCI proprietary approach, sorbent particles are injected into a gas stream subjected to an intense acoustic field. The acoustic field serves to improve sulfur capture efficiency by enhancing both gas film and intra-particle mass transfer rates. In addition, the sorbent particles act as dynamic filter foci, providing a high density of stagnant agglomerating centers for trapping the finer entrained (in the oscillating flow field) fly ash fractions. A team has been formed with MTCI as the prime contractor and Penn State University and West Virginia University as subcontractors to MTCI. MTCI is focusing on hardware development and system demonstration, PSU is investigating and modeling acoustic agglomeration and sulfur capture, and WVU is studying aerovalve fluid dynamics. Results are presented from all three studies.

  12. Satellite and acoustic tracking device

    KAUST Repository

    Berumen, Michael L.


    The present invention relates a method and device for tracking movements of marine animals or objects in large bodies of water and across significant distances. The method and device can track an acoustic transmitter attached to an animal or object beneath the ocean surface by employing an unmanned surface vessel equipped with a hydrophone array and GPS receiver.

  13. Acoustic design by topology optimization

    DEFF Research Database (Denmark)

    Dühring, Maria Bayard; Jensen, Jakob Søndergaard; Sigmund, Ole


    To bring down noise levels in human surroundings is an important issue and a method to reduce noise by means of topology optimization is presented here. The acoustic field is modeled by Helmholtz equation and the topology optimization method is based on continuous material interpolation functions...

  14. Current and noise in driven heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, Franz


    propagating waves. For a qualitative analysis of surface acoustic wave driven quantum dot systems, we adopted our model to the static situation and extracted the numerical values. Recent measurements of the photoconductive gain and more detailed studies on photo induced ballistic transport indicated an influence of geometrical constraints on the electron path. Within this thesis we numerically evaluate the current for latter in two distinct geometries. Unlike in the other systems discussed in this thesis, we simulate the electrons as free non-interacting particles. (orig.)

  15. Handbook of Signal Processing in Acoustics

    CERN Document Server

    Havelock, David; Vorländer, Michael


    The Handbook of Signal Processing in Acoustics presents signal processing as it is practiced in the field of acoustics. The Handbook is organized by areas of acoustics, with recognized leaders coordinating the self-contained chapters of each section. It brings together a wide range of perspectives from over 100 authors to reveal the interdisciplinary nature of signal processing in acoustics. Success in acoustic applications often requires juggling both the acoustic and the signal processing parameters of the problem. This handbook brings the key issues from both into perspective and is complementary to other reference material on the two subjects. It is a unique resource for experts and practitioners alike to find new ideas and techniques within the diversity of signal processing in acoustics.

  16. A synchronous serial bus for multidimensional array acoustic logging tool (United States)

    Men, Baiyong; Ju, Xiaodong; Lu, Junqiang; Qiao, Wenxiao


    In high-temperature and spatial borehole applications, a distributed structure is employed in a multidimensional array acoustic logging tool (MDALT) based on a phased array technique for electronic systems. However, new challenges, such as synchronous multichannel data acquisition, multinode real-time control and bulk data transmission in a limited interval, have emerged. To address these challenges, we developed a synchronous serial bus (SSB) in this study. SSB works in a half-duplex mode via a master-slave architecture. It also consists of a single master, several slaves, a differential clock line and a differential data line. The clock line is simplex, whereas the data line is half-duplex and synchronous to the clock line. A reliable communication between the master and the slaves with real-time adjustment of synchronisation is achieved by rationally designing the frame format and protocol of communication and by introducing a scramble code and a Hamming error-correcting code. The control logic of the master and the slaves is realized in field programmable gate array (FPGA) or complex programmable logic device (CPLD). The clock speed of SSB is 10 MHz, the effective data rate of the bulk data transmission is over 99%, and the synchronous errors amongst the slaves are less than 10 ns. Room-temperature test, high-temperature test (175 °C) and field test demonstrate that the proposed SSB is qualified for MDALT.

  17. The MISTRALS programme data portal (United States)

    Brissebrat, Guillaume; Albert-Aguilar, Alexandre; Belmahfoud, Nizar; Cloché, Sophie; Darras, Sabine; Descloitres, Jacques; Ferré, Hélène; Fleury, Laurence; Focsa, Loredana; Henriot, Nicolas; Labatut, Laurent; Petit de la Villéon, Loïc; Ramage, Karim; Schmechtig, Catherine; Vermeulen, Anne


    Mediterranean Integrated STudies at Regional And Local Scales (MISTRALS) is a decennial programme for systematic observations and research dedicated to the understanding of the Mediterranean Basin environmental process and its evolution under the planet global change. It is composed of eight multidisciplinary projects that cover all the components of the Earth system (atmosphere, ocean, continental surfaces, lithosphere...) and their interactions, all the disciplines (physics, chemistry, marine biogeochemistry, biology, geology, sociology...) and different time scales. For example Hydrological cycle in the Mediterranean eXperiment (HyMeX) aims at improving the predictability of rainfall extreme events, and assessing the social and economic vulnerability to extreme events and adaptation capacity. Paleo Mediterranean Experiment (PaleoMeX) is dedicated to the study of the interactions between climate, societies and civilizations of the Mediterranean world during the last 10000 years. Many long term monitoring research networks are associated with MISTRALS, such as Mediterranean Ocean Observing System on Environment (MOOSE), Centre d'Observation Régional pour la Surveillance du Climat et de l'environnement Atmosphérique et océanographique en Méditerranée occidentale (CORSICA) and the environmental observations from Mediterranean Eurocentre for Underwater Sciences and Technologies (MEUST-SE). Therefore, the data generated or used by the different MISTRALS projects are very heterogeneous. They include in situ observations, satellite products, model outputs, social sciences surveys... Some datasets are automatically produced by operational networks, and others come from research instruments and analysis procedures. They correspond to different time scales (historical time series, observatories, campaigns...) and are managed by several data centres. They originate from many scientific communities, with different data sharing practices, specific expectations and using

  18. Constellations-driven innovation

    DEFF Research Database (Denmark)

    Hansbøl, Mikala


    The paper presents a science and technology studies and actor-network-theory inspired approach to understanding the development and ongoing re-didactication and re-design of a Danish developed presentation tool called the Theme Board ( It is argued that this approach provides a par...... a particularly useful point of departure for engaging in researching innovation and didactic design of digital teaching and learning instruments such as the Theme Board that are programmed and serviced 'in the sky'. I call this approach: constellation-driven innovations....

  19. Bolsa Família (Family Grant Programme: an analysis of Brazilian income transfer programme

    Directory of Open Access Journals (Sweden)

    Luciana Mourão


    Full Text Available Income transfer programmes are common in various countries and play an important role in combating poverty. This article presents a review of the results of the Bolsa Família (Family Grant Programme, implemented in Brazil by the government of Lula da Silva in 2004. Over the last seven years many evaluations of the programme have been conducted, allowing an overview of its results and its strong and weak points to be mapped. Five central aspects relating to the programme are discussed in article five: (1 programme access, (2 hunger fighting results, (3 programme financial impacts, (4 conditioning factors of education and health, (5 supplementary programs and social mobility. The results of scientific research were presented for each of these aspects, and any of these believed to be convergent or divergent were discussed. As a general result it was concluded that the programme has generated significant results for the country, but there are still some issues that need to be reviewed, such as conditioning factors and the integrated management of the programme.

  20. Bolsa Família (Family Grant) Programme: an analysis of Brazilian income transfer programme

    NARCIS (Netherlands)

    L. Mourao (Luciana); A. Macedo de Jesus (Anderson)


    markdownabstract__Abstract__ Income transfer programmes are common in various countries and play an important role in combating poverty. This article presents a review of the results of the Bolsa Família (Family Grant) Programme, implemented in Brazil by the government of Lula da Silva in 2004. Ove

  1. Embracing the complexity of educational programmes

    Directory of Open Access Journals (Sweden)

    Elly Govers


    Full Text Available Systems of monitoring and control have left many educators and organisations in the field of post-compulsory education struggling to find ways to meet the needs of an increasingly diverse society. Education is complex. Many educators would agree that it is influenced by many, often contradictory, voices and power structures. Based on the findings of a case study involving multiple programmes in a post-compulsory education institution in Aotearoa/New Zealand, this paper aims to unravel this complexity for the case of educational programmes. It describes how programmes can be seen as complex systems, created by people and directed by discourses in society, some of which are more influential than others. If programmes are seen as complex systems, the experience of struggle as referred to above can be understood as a consequence of the attempt to control the complexity rather than work with it. This control limits the possibilities for development and innovation. Alternatively, as this paper will explain, acknowledging and embracing the complexity of programmes helps open up spaces for innovation that would otherwise remain hidden. It is argued that the ultimate space for change is educators’ personal and collective responsibility for the discourses in society they choose to follow.

  2. Setting up a structured laboratory mentoring programme

    Directory of Open Access Journals (Sweden)

    Talkmore Maruta


    Full Text Available Introduction: Laboratory mentoring programmes can be an important vehicle to establish and solidify quality management systems and help laboratories achieve accreditation goals. Different mentoring approaches have been used with varying levels of success. The authors provide a guide to implementing a structured laboratory mentorship programme based on their practical field experience.Method: The study is based on experience in Lesotho as well as subsequent roll out of a similar approach in the other African countries of Zimbabwe, Mozambique, Swaziland and Cameroon between 2009 and 2011.Summary: We highlight critical elements to consider when setting up a long-term, sustainable and well-structured mentorship programme. These elements include: well-defined goals; sufficient length of mentor engagement on site; standardised approach across laboratories; measurement of progress using standardised tools; well-structured reporting mechanisms; alignment of the programme with overall Ministry of Health plans; and selection and training of the mentors. These elements will differ in application, depending on countries’ needs and available resources. A structured approach allows for scalability, comparison across laboratories and countries and an easier approach to budgeting and planning for countries intending to set up similar programmes.

  3. Acoustic field interaction with a boiling system under terrestrial gravity and microgravity. (United States)

    Sitter, J S; Snyder, T J; Chung, J N; Marston, P L


    Pool boiling experiments from a platinum wire heater in FC-72 liquid were conducted under terrestrial and microgravity conditions, both with and without the presence of a high-intensity acoustic standing wave within the fluid. The purpose of this research was to study the interaction between an acoustic field and a pool boiling system in normal gravity and microgravity. The absence of buoyancy in microgravity complicates the process of boiling. The acoustic force on a vapor bubble generated from a heated wire in a standing wave was shown to be able to play the role of buoyancy in microgravity. The microgravity environment was achieved with 0.6 and 2.1-s drop towers. The sound was transmitted through the fluid medium by means of a half wavelength sonic transducer driven at 10.18 kHz. At high enough acoustic pressure amplitudes cavitation and streaming began playing an important role in vapor bubble dynamics and heat transfer. Several different fixed heat fluxes were chosen for the microgravity experiment and the effects of acoustics on the surface temperature of the heater were recorded and the vapor bubble movement was filmed. Video images of the pool boiling processes and heat transfer data are presented.

  4. Improved optically driven microrotors (United States)

    Asavei, Theodor; Loke, Vincent L. Y.; Nieminen, Timo A.; Heckenberg, Norman R.; Rubinsztein-Dunlop, Halina


    Two-photon polymerization of optically curing resins is a powerful method to fabricate micron sized objects which can be used as tools to measure properties at small scales. These microdevices can be driven by means of externally applied focused laser beams (optical tweezers) through angular momentum exchange, giving rise to a net torque. The advantage of the optical drive is that no contact is required, therefore making the microdevices suited to non-invasive biological applications. The fabrication method is versatile and allows building objects of any 3D shape. We discuss the design and modelling of various optically driven rotors. In particular, we consider fabrication of microspheres with an internal shape birefringence in order to obtain rotation in an optical trap. The reason for fabricating this type of object is that they are well-suited for studies of mechanical properties of single biomolecules such as the torsional stiffness of DNA or torque generated by molecular motors. The microspheres fabricated are able to transduce torques of 2000 pNnm with optical powers of 500 mW and could be rotated with frequencies up to 40 Hz in circularly polarized light.

  5. Libration driven multipolar instabilities

    CERN Document Server

    Cébron, David; Herreman, Wietze


    We consider rotating flows in non-axisymmetric enclosures that are driven by libration, i.e. by a small periodic modulation of the rotation rate. Thanks to its simplicity, this model is relevant to various contexts, from industrial containers (with small oscillations of the rotation rate) to fluid layers of terrestial planets (with length-of-day variations). Assuming a multipolar $n$-fold boundary deformation, we first obtain the two-dimensional basic flow. We then perform a short-wavelength local stability analysis of the basic flow, showing that an instability may occur in three dimensions. We christen it the Libration Driven Multipolar Instability (LDMI). The growth rates of the LDMI are computed by a Floquet analysis in a systematic way, and compared to analytical expressions obtained by perturbation methods. We then focus on the simplest geometry allowing the LDMI, a librating deformed cylinder. To take into account viscous and confinement effects, we perform a global stability analysis, which shows that...

  6. Heat driven pulse pump (United States)

    Benner, Steve M (Inventor); Martins, Mario S. (Inventor)


    A heat driven pulse pump includes a chamber having an inlet port, an outlet port, two check valves, a wick, and a heater. The chamber may include a plurality of grooves inside wall of the chamber. When heated within the chamber, a liquid to be pumped vaporizes and creates pressure head that expels the liquid through the outlet port. As liquid separating means, the wick, disposed within the chamber, is to allow, when saturated with the liquid, the passage of only liquid being forced by the pressure head in the chamber, preventing the vapor from exiting from the chamber through the outlet port. A plurality of grooves along the inside surface wall of the chamber can sustain the liquid, which is amount enough to produce vapor for the pressure head in the chamber. With only two simple moving parts, two check valves, the heat driven pulse pump can effectively function over the long lifetimes without maintenance or replacement. For continuous flow of the liquid to be pumped a plurality of pumps may be connected in parallel.

  7. High-overtone Bulk-Acoustic Resonator gravimetric sensitivity: towards wideband acoustic spectroscopy

    CERN Document Server

    Rabus, D; Ballandras, S; Baron, T; Lebrasseur, E; Carry, E


    In the context of direct detection sensors with compact dimensions, we investigate the gravimetric sensitivity of High-overtone Bulk Acoustic Resonators, through modeling of their acoustic characteristics and experiment. The high frequency characterizing such devices is expected to induce a significant effect when the acoustic field boundary conditions are modified by a thin adlayer. Furthermore, the multimode spectral characteristics is considered for wideband acoustic spectroscopy of the adlayer, once the gravimetric sensitivity dependence of the various overtones is established. Finally, means of improving the gravimetric sensitivity by confining the acoustic field in a low acoustic-impedance layer is theoretically established.

  8. Design studies of a high-current radiofrequency quadrupole for accelerator-driven systems programme

    Indian Academy of Sciences (India)

    S V L S Rao; P Singh


    A 3 MeV, 30 mA radiofrequency quadrupole (RFQ) accelerator has been designed for the low-energy high-intensity proton accelerator (LEHIPA) project at BARC, India. The beam and cavity dynamics studies were performed using the computer codes LIDOS, TOUTATIS, SUPERFISH and CST microwave studio. We have followed the conventional design technique with slight modifications and compared that with the equipartitioned (EP) type of design. The sensitivity of the RFQ to the variation of input beam Twiss–Courant parameters and emittance has also been studied. In this article we discuss both design strategies and the details of the 3D cavity simulation studies.

  9. Transformation challenges following the efficient lean practice implementation in the programme organized, project driven change process

    DEFF Research Database (Denmark)

    Matthiesen, Rikke Vestergaard

    Ph.d. studiet tager sit udgangspunkt i en case virksomhed der har etableret en central programorganisation til at varetage effektiv implementering af lean teknikker og værktøjer ved hjælp af lean projekter der rulles ud i alle dele af virksomhedens produktion. Studiet beskæftiger sig med at afdække...... hvorledes lokale produktionsenheders erfaringer med disse projekter og ibrugtagning af implementerede systemer bidrager til udviklingen af adfærd og systemer i overensstemmelse med lean tankegangen. Ved hjælp af interviews og observation indsnævrer studiet nogle karakteristika ved en vedvarende...

  10. Policy Pathways: Energy Management Programmes for Industry

    Energy Technology Data Exchange (ETDEWEB)



    The IEA Policy Pathway publications provide details on how to implement specific recommendations drawn from the IEA 25 Energy Efficiency Policy Recommendations. This Policy Pathway, jointly produced by the International Energy Agency and the Institute for Industrial Productivity, develops the critical steps for policy makers implementing energy management programmes for industry. Optimising energy use in industry is essential to improve industrial competitiveness and achieve wider societal goals such as energy security, economic recovery and development, climate change mitigation and environmental protection.While there is significant potential to decrease energy consumption in this sector, opportunities to improve energy efficiency are still under-exploited. Energy management programmes have shown to be instrumental in addressing many of the barriers that inhibit wide-scale uptake of energy management in industry. The Policy Pathway builds on lessons learned from country experiences and provides actionable guidance on how to plan and design, implement, evaluate and monitor energy management programmes for industry.

  11. Evaluation of the cleaner technology programme

    DEFF Research Database (Denmark)

    Andersen, Mikael Skou; Jørgensen, Ulrik

    The report presents an independent evaluation of the Danish development programme for cleaner technology 1986-1989 and of the Action Plan for Cleaner Technology 1990-1992. The evaluation focuses on the results of technology development and implementation projects, on an examination of the dissemi...... of the dissemination of cleaner technology solutions achieved in six industrial branches, and on the overall programme and its effects, in particular environmental impacts, but also results in the form of employment, environmental export, strenghtening of Danish know-how etc.......The report presents an independent evaluation of the Danish development programme for cleaner technology 1986-1989 and of the Action Plan for Cleaner Technology 1990-1992. The evaluation focuses on the results of technology development and implementation projects, on an examination...

  12. Evaluation and impact of cardiotocography training programmes

    DEFF Research Database (Denmark)

    Pehrson, Caroline; Sorensen, J. L.; Amer-Wåhlin, I.


    with improvements on all Kirkpatrick levels, resulting in increased CTG knowledge and interpretive skills, higher interobserver agreement, better management of intrapartum CTG, and improved quality of care. Computer-based training (CBT) might be less time-consuming than classroom teaching. Clinical skills seem......Background: The interpretation and management of cardiotocography (CTG) tracings are often criticised in obstetric malpractice cases. As a consequence, regular CTG training has been recommended, even though little is known about the effect of CTG training. Objectives: To perform a systematic review...... of the existing literature on studies on CTG training in order to assess educational strategies, evaluation of training programmes, and impact of training programmes. Search strategy: The Medline database was searched to identify studies describing and/or evaluating CTG training programmes. The literature search...

  13. The volunteer programme ‘Night Ravens’:

    DEFF Research Database (Denmark)

    Larsen, Britt Østergaard; Bendix Kleif, Helle; Kolodziejczyk, Christophe


    are based on a longitudinal data set containing socio-demographic information on all 585 postcode districts in Denmark and quarterly records of six different categories of reported crimes in the years 2001–2010.We apply a difference-in-difference design and compare development in crime rates in districts...... with NR organizations to districts without NR organizations. The results show no difference in the crime rates between Danish postcode districts with and without the NR programme. Hence, we cannot identify positive effects of situational crime prevention when evaluating this Scandinavian volunteer......The volunteer programme ‘Night Ravens’ (NR) was founded in Sweden in 1987 and has, over the years, developed into a Scandinavian concept covering large areas of Sweden, Denmark, Norway, Greenland and the Faroe Islands. The NR programme is a crime prevention initiative with adults walking...

  14. Programmable DNA-mediated multitasking processor

    CERN Document Server

    Shu, Jian-Jun; Yong, Kian-Yan; Shao, Fangwei; Lee, Kee Jin


    Because of DNA appealing features as perfect material, including minuscule size, defined structural repeat and rigidity, programmable DNA-mediated processing is a promising computing paradigm, which employs DNAs as information storing and processing substrates to tackle the computational problems. The massive parallelism of DNA hybridization exhibits transcendent potential to improve multitasking capabilities and yield a tremendous speed-up over the conventional electronic processors with stepwise signal cascade. As an example of multitasking capability, we present an in vitro programmable DNA-mediated optimal route planning processor as a functional unit embedded in contemporary navigation systems. The novel programmable DNA-mediated processor has several advantages over the existing silicon-mediated methods, such as conducting massive data storage and simultaneous processing via much fewer materials than conventional silicon devices.

  15. System Synthesis for Networks of Programmable Blocks

    CERN Document Server

    Mannion, Ryan; Cotterell, Susan; Vahid, Frank


    The advent of sensor networks presents untapped opportunities for synthesis. We examine the problem of synthesis of behavioral specifications into networks of programmable sensor blocks. The particular behavioral specification we consider is an intuitive user-created network diagram of sensor blocks, each block having a pre-defined combinational or sequential behavior. We synthesize this specification to a new network that utilizes a minimum number of programmable blocks in place of the pre-defined blocks, thus reducing network size and hence network cost and power. We focus on the main task of this synthesis problem, namely partitioning pre-defined blocks onto a minimum number of programmable blocks, introducing the efficient but effective PareDown decomposition algorithm for the task. We describe the synthesis and simulation tools we developed. We provide results showing excellent network size reductions through such synthesis, and significant speedups of our algorithm over exhaustive search while obtaining...

  16. Sellafield Decommissioning Programme - Update and Lessons Learned

    Energy Technology Data Exchange (ETDEWEB)

    Lutwyche, P. R.; Challinor, S. F.


    The Sellafield site in North West England has over 240 active facilities covering the full nuclear cycle from fuel manufacture through generation, reprocessing and waste treatment. The Sellafield decommissioning programme was formally initiated in the mid 1980s though several plants had been decommissioned prior to this primarily to create space for other plants. Since the initiation of the programme 7 plants have been completely decommissioned, significant progress has been made in a further 16 and a total of 56 major project phases have been completed. This programme update will explain the decommissioning arrangements and strategies and illustrate the progress made on a number of the plants including the Windscale Pile Chimneys, the first reprocessing plan and plutonium plants. These present a range of different challenges and requiring approaches from fully hands on to fully remote. Some of the key lessons learned will be highlighted.

  17. Astroparticle physics: the new ASPERA-2 programme

    CERN Multimedia


    On 7 July the ASPERA-2 programme funded by the European Commission was officially launched in Hamburg with the goal of creating a sustainable structure for the coordination of astroparticle physics in Europe. CERN, which is a participant in the programme, could play an important role in this respect. Artist’s impression of the CTA (Cherenkov Telescope Array). The CTA is one of the "Magnificent Seven", the seven large astroparticle physics infrastructures planned for the coming years. It is the next-generation facility destined to succeed the H.E.S.S. telescope in Namibia and the MAGIC telescope in the Canary Islands. (Credit ASPERA/G.Toma/A.Saftoiu). Following the success of ASPERA-1, the European network for astroparticle physics (see box), funding agency representatives gathered in Hamburg on 7 July 2009 for the official launch of ASPERA-2, a new three-year programme funded by the European Commission. Today the strategic roles of ...

  18. The SAS-3 programmable telemetry system (United States)

    Peterson, M. R.


    Basic concept, system design and operation principles of the telemetry system developed for the Small Astronomy Satellite-3 (SAS-3) are analyzed. The concept of programmable format selected for the SAS-3 represents an optical combination of the fixed format system of SAS-1 and SAS-2, and the adaptive format concept. The programmable telemetry system permits a very wide range of changes in the data sampling order by a ground control station, depending on the experimental requirements, so that the maximal amount of useful data can be returned from orbit. The programmable system also allows the data format to differ from one spacecraft to another without changing hardware. Attention is given to the command requirements and redundancy of the SAS-3 telemetry system.


    Institute of Scientific and Technical Information of China (English)


    Conventional element based methods for modeling acoustic problems are limited to low-frequency applications due to the huge computational efforts. For high-frequency applications, probabilistic techniques, such as statistical energy analysis (SEA), are used. For mid-frequency range, currently no adequate and mature simulation methods exist. Recently, wave based method has been developed which is based on the indirect TREFFTZ approach and has shown to be able to tackle problems in the mid-frequency range. In contrast with the element based methods, no discretization is required. A sufficient, but not necessary, condition for convergence of this method is that the acoustic problem domain is convex. Non-convex domains have to be partitioned into a number of (convex) subdomains. At the interfaces between subdomains, specific coupling conditions have to be imposed. The considered two-dimensional coupled vibro-acoustic problem illustrates the beneficial convergence rate of the proposed wave based prediction technique with high accuracy. The results show the new technique can be applied up to much higher frequencies.

  20. Spontaneous assembly of chemically encoded two-dimensional coacervate droplet arrays by acoustic wave patterning (United States)

    Tian, Liangfei; Martin, Nicolas; Bassindale, Philip G.; Patil, Avinash J.; Li, Mei; Barnes, Adrian; Drinkwater, Bruce W.; Mann, Stephen


    The spontaneous assembly of chemically encoded, molecularly crowded, water-rich micro-droplets into periodic defect-free two-dimensional arrays is achieved in aqueous media by a combination of an acoustic standing wave pressure field and in situ complex coacervation. Acoustically mediated coalescence of primary droplets generates single-droplet per node micro-arrays that exhibit variable surface-attachment properties, spontaneously uptake dyes, enzymes and particles, and display spatial and time-dependent fluorescence outputs when exposed to a reactant diffusion gradient. In addition, coacervate droplet arrays exhibiting dynamical behaviour and exchange of matter are prepared by inhibiting coalescence to produce acoustically trapped lattices of droplet clusters that display fast and reversible changes in shape and spatial configuration in direct response to modulations in the acoustic frequencies and fields. Our results offer a novel route to the design and construction of `water-in-water' micro-droplet arrays with controllable spatial organization, programmable signalling pathways and higher order collective behaviour.