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Sample records for tiny whispering gallery

  1. Effects of whispering gallery mode in microsphere super-resolution imaging

    Science.gov (United States)

    Zhou, Song; Deng, Yongbo; Zhou, Wenchao; Yu, Muxin; Urbach, H. P.; Wu, Yihui

    2017-09-01

    Whispering Gallery modes have been presented in microscopic glass spheres or toruses with many applications. In this paper, the possible approaches to enhance the imaging resolution by Whispering Gallery modes are discussed, including evanescent waves coupling, transformed and illustration by Whispering Gallery modes. It shows that the high-order scattering modes play the dominant role in the reconstructed virtual image when the Whispering Gallery modes exist. Furthermore, we find that the high image resolution of electric dipoles can be achieved, when the out-of-phase components exist from the illustration of Whispering Gallery modes. Those results of our simulation could contribute to the knowledge of microsphere-assisted super-resolution imaging and its potential applications.

  2. Whispering gallery mode emission from a composite system of J-aggregates and photonic microcavity

    Energy Technology Data Exchange (ETDEWEB)

    Melnikau, Dzmitry; Savateeva, Diana [Centro de Física de Materiales (MPC, CSIC-UPV/EHU) and Donostia International Physics Center (DIPC), Po Manuel de Lardizabal 5, Donostia, San Sebastian 20018 (Spain); Rusakov, Konstantin I. [Department of Physics, Brest State Technical University, Brest 224017 (Belarus); Rakovich, Yury P., E-mail: Yury.Rakovich@ehu.es [Centro de Física de Materiales (MPC, CSIC-UPV/EHU) and Donostia International Physics Center (DIPC), Po Manuel de Lardizabal 5, Donostia, San Sebastian 20018 (Spain); IKERBASQUE, Basque Foundation for Science, Bilbao (Spain)

    2014-01-15

    We report on development and characterization of Whispering Gallery Modes spherical microcavities integrated with organic dye molecules in a J-aggregate state. The microcavities are studied using micro-photoluminescence spectroscopy, and fluorescence lifetime imaging confocal microscopy. Directional emission of light from the microcavity is also experimentally demonstrated and attributed to the photonic jets generated in the microsphere. -- Highlights: • Report on the development and characterization of hybrid system consisting of thin shell of J-aggregates and spherical Whispering Gallery Mode microcavity. • An investigation of spontaneous emission rate in the shell of J-aggregates integrated with a Whispering Gallery Mode cavity. • Demonstration of directional emission from Whispering Gallery Mode cavity with J-aggregates which is highly desirable functionality for both micro- and nano-scale cavities.

  3. Whispering Gallery Mode Spectroscopy as a Diagnostic for Dusty Plasmas

    International Nuclear Information System (INIS)

    Thieme, G.; Basner, R.; Ehlbeck, J.; Roepcke, J.; Maurer, H.; Kersten, H.; Davies, P. B.

    2008-01-01

    Whispering-gallery-mode spectroscopy is being assessed as a diagnostic method for the characterisation of size and chemical composition of spherical particles levitated in a plasma. With a pulsed laser whispering gallery modes (cavity resonances) are excited in individual microspheres leading to enhanced Raman scattering or fluorescence at characteristic wavelengths. This method can be used to gain specific information from the particle surface and is thus of great interest for the characterisation of layers deposited on microparticles, e.g. in molecular plasmas. We present investigations of different microparticles in air and results from fluorescent particles levitated in an Argon rf plasma.

  4. The influence of the whispering gallery modes resonators shape on their sensitivity to the movement

    Science.gov (United States)

    Filatov, Yuri V.; Govorenko, Ekaterina V.; Kukaev, Alexander S.; Shalymov, Egor V.; Venediktov, Vladimir Yu.

    2017-05-01

    The optical whispering gallery modes resonators are axially symmetrical resonators with smooth edges, supporting the existence of the whispering gallery modes by the total internal reflection on the surface of the resonator. For today various types of such resonators were developed, namely the ball-shaped, tor-shaped, bottle-shaped, disk-shaped etc. The movement of whispering gallery modes resonators in inertial space causes the changes of their shape. The result is a spectral shift of the whispering gallery modes. Optical methods allow to register this shift with high precision. It can be used in particular for the measurement of angular velocities in inertial orientation and navigation systems. However, different types of resonators react to the movement on a miscellaneous. In addition, their sensitivity to movement can be changed when changing the geometric parameters of these resonators. This work is devoted to a research of these aspects.

  5. Whispering gallery mode selection in optical bottle microresonators

    Science.gov (United States)

    Ding, Ming; Senthil Murugan, Ganapathy; Brambilla, Gilberto; Zervas, Michalis N.

    2012-02-01

    We demonstrated a method to excite selected whispering gallery modes in optical bottle microresonators (BMR) by inscribing microgroove scars on their surface by focused ion beam milling. Substantial spectral clean-up is obtained in appropriately scarred BMRs, providing the potential for high performance sensors and other optical devices.

  6. The whispering gallery as an optical component in the X-ray region

    International Nuclear Information System (INIS)

    Howells, M.R.

    1995-08-01

    The whispering gallery phenomenon in acoustics has been known and studied for more than a century, and the same effect has been observed to take place with waves other than sound waves. In this paper we review the theoretical basis and attractive features of the whispering gallery as a soft x-ray optical component and indicate some of its potential applications. We then describe what may be its most unique capability which, in favorable cases, is to provide a way. to manipulate the phase difference between the s and p polarization components and thus to generate circularly or elliptically polarized soft x-rays

  7. Detecting single viruses and nanoparticles using whispering gallery microlasers.

    Science.gov (United States)

    He, Lina; Ozdemir, Sahin Kaya; Zhu, Jiangang; Kim, Woosung; Yang, Lan

    2011-06-26

    There is a strong demand for portable systems that can detect and characterize individual pathogens and other nanoscale objects without the use of labels, for applications in human health, homeland security, environmental monitoring and diagnostics. However, most nanoscale objects of interest have low polarizabilities due to their small size and low refractive index contrast with the surrounding medium. This leads to weak light-matter interactions, and thus makes the label-free detection of single nanoparticles very difficult. Micro- and nano-photonic devices have emerged as highly sensitive platforms for such applications, because the combination of high quality factor Q and small mode volume V leads to significantly enhanced light-matter interactions. For example, whispering gallery mode microresonators have been used to detect and characterize single influenza virions and polystyrene nanoparticles with a radius of 30 nm (ref. 12) by measuring in the transmission spectrum either the resonance shift or mode splitting induced by the nanoscale objects. Increasing Q leads to a narrower resonance linewidth, which makes it possible to resolve smaller changes in the transmission spectrum, and thus leads to improved performance. Here, we report a whispering gallery mode microlaser-based real-time and label-free detection method that can detect individual 15-nm-radius polystyrene nanoparticles, 10-nm gold nanoparticles and influenza A virions in air, and 30 nm polystyrene nanoparticles in water. Our approach relies on measuring changes in the beat note that is produced when an ultra-narrow emission line from a whispering gallery mode microlaser is split into two modes by a nanoscale object, and these two modes then interfere. The ultimate detection limit is set by the laser linewidth, which can be made much narrower than the resonance linewidth of any passive resonator. This means that microlaser sensors have the potential to detect objects that are too small to be

  8. Microwave oscillator with 'whispering gallery' resonator

    International Nuclear Information System (INIS)

    Kirichenko, A.Ya.; Prokopenko, Yu.V.; Filippov, Yu.F.; Lonin, Yu.F.; Papkovich, V.G.; Ponomarev, A.G.; Prokopenko, Yu.V.; Uvarov, V.T.

    2010-01-01

    It was presented researches of a generation of microwave radiation into system with azimuthally periodical relativistic electron beam current that excites a high-Q quasi-optical dielectric resonator. The Eigen parameters of cylindrical Teflon resonator were determined by numerical computation. Registration of the microwave radiation realizes by a crystal set of 8-mm wavelength range. Research projects of microwave oscillators with high-Q resonators, in which 'whispering gallery' oscillations are excited by an electron flow, are presented. Multiresonator oscillators ideology is based on principles of microwave generation in klystrons with both subcritical and supercritical electron beams currents.

  9. Whispering gallery effect in relativistic optics

    Science.gov (United States)

    Abe, Y.; Law, K. F. F.; Korneev, Ph.; Fujioka, S.; Kojima, S.; Lee, S.-H.; Sakata, S.; Matsuo, K.; Oshima, A.; Morace, A.; Arikawa, Y.; Yogo, A.; Nakai, M.; Norimatsu, T.; d'Humières, E.; Santos, J. J.; Kondo, K.; Sunahara, A.; Gus'kov, S.; Tikhonchuk, V.

    2018-03-01

    relativistic laser pulse, confined in a cylindrical-like target, under specific conditions may perform multiple scattering along the internal target surface. This results in the confinement of the laser light, leading to a very efficient interaction. The demonstrated propagation of the laser pulse along the curved surface is just yet another example of the "whispering gallery" effect, although nonideal due to laser-plasma coupling. In the relativistic domain its important feature is a gradual intensity decrease, leading to changes in the interaction conditions. The proccess may pronounce itself in plenty of physical phenomena, including very efficient electron acceleration and generation of relativistic magnetized plasma structures.

  10. Sensitivity optimization in whispering gallery mode optical cylindrical biosensors

    Science.gov (United States)

    Khozeymeh, F.; Razaghi, M.

    2018-01-01

    Whispering-gallery-mode resonances propagated in cylindrical resonators have two angular and radial orders of l and i. In this work, the higher radial order whispering-gallery-mode resonances, (i = 1 - 4), at a fixed l are examined. The sensitivity of theses resonances is analysed as a function of the structural parameters of the cylindrical resonator like different radii and refractive index of composed material of the resonator. A practical application where cylindrical resonators are used for the measurement of glucose concentration in water is presented as a biosensor demonstrator. We calculate the wavelength shifts of the WG1-4, in several glucose/water solutions, with concentrations spanning from 0.0% to 9.0.% (weight/weight). Improved sensitivity can be achieved using multi-WGM cylindrical resonators with radius of R = 100 μm and resonator composed material of MgF 2 with refractive index of nc = 1.38. Also the effect of polarization on sensitivity is considered for all four WGMs. The best sensitivity of 83.07 nm/RIU for the fourth WGM with transverse magnetic polarization, is reported. These results propose optimized parameters aimed to fast designing of cylindrical resonators as optical biosensors, where both the sensitivity and the geometries can be optimized.

  11. Two photon versus one photon fluorescence excitation in whispering gallery mode microresonators

    International Nuclear Information System (INIS)

    Pastells, Carme; Marco, M.-Pilar; Merino, David; Loza-Alvarez, Pablo; Pasquardini, Laura; Lunelli, Lorenzo; Pederzolli, Cecilia; Daldosso, Nicola; Farnesi, Daniele; Berneschi, Simone; Righini, Giancarlo C.; Quercioli, Franco; Nunzi Conti, Gualtiero; Soria, Silvia

    2016-01-01

    We investigate the feasibility of both one photon and two photon fluorescence excitation using whispering gallery mode microresonators. We report the linear and non linear fluorescence real-time detection of labeled IgG covalently bonded to the surface of a silica whispering gallery mode resonator (WGMR). The immunoreagents have been immobilized onto the surface of the WGMR sensor after being activated with an epoxy silane and an orienting layer. The developed immunosensor presents great potential as a robust sensing device for fast and early detection of immunoreactions. We also investigate the potential of microbubbles as nonlinear enhancement platform. The dyes used in these studies are dylight800, tetramethyl rhodamine isothiocyanate, rhodamine 6G and fluorescein. All measurements were performed in a modified confocal microscope. - Highlights: • One photon fluorescence overlaps with the semiconductor pump laser gain bandwidth. • We report on the feasibility to excite two photon fluorescence in microbubble resonators. • Our functionalization process maintains a good quality factor of the microresonator.

  12. Two photon versus one photon fluorescence excitation in whispering gallery mode microresonators

    Energy Technology Data Exchange (ETDEWEB)

    Pastells, Carme; Marco, M.-Pilar [Nanobiotechnology for Diagnostics Group (Nb4Dg), IQAC-CSIC, 08034 Barcelona (Spain); CIBER de Bioingeniería, Biomateriales y Nanomedicina, 08034 Barcelona (Spain); Merino, David; Loza-Alvarez, Pablo [ICFO-Institut de Ciències Fotòniques, Castelldefels, 08860 Barcelona (Spain); Pasquardini, Laura [Fondazione Bruno Kessler, 38123 Povo, TN (Italy); Lunelli, Lorenzo [Fondazione Bruno Kessler, 38123 Povo, TN (Italy); IBF-CNR, 38123 Povo, TN (Italy); Pederzolli, Cecilia [Fondazione Bruno Kessler, 38123 Povo, TN (Italy); Daldosso, Nicola [Department of Computer Science, University of Verona, Strada le Grazie 15, 37134 Verona (Italy); Farnesi, Daniele [CNR-IFAC “Nello Carrara” Institute of Applied Physics, 50019 Sesto Fiorentino, FI (Italy); Museo Storico della Fisica e Centro Studi e Ricerche “E. Fermi”, 00184 Roma (Italy); Berneschi, Simone [CNR-IFAC “Nello Carrara” Institute of Applied Physics, 50019 Sesto Fiorentino, FI (Italy); Righini, Giancarlo C. [CNR-IFAC “Nello Carrara” Institute of Applied Physics, 50019 Sesto Fiorentino, FI (Italy); Museo Storico della Fisica e Centro Studi e Ricerche “E. Fermi”, 00184 Roma (Italy); Quercioli, Franco [CNR-INO National Institute of Optics, Sesto Fiorentino, FI (Italy); Nunzi Conti, Gualtiero [CNR-IFAC “Nello Carrara” Institute of Applied Physics, 50019 Sesto Fiorentino, FI (Italy); Soria, Silvia, E-mail: s.soria@ifac.cnr.it [CNR-IFAC “Nello Carrara” Institute of Applied Physics, 50019 Sesto Fiorentino, FI (Italy)

    2016-02-15

    We investigate the feasibility of both one photon and two photon fluorescence excitation using whispering gallery mode microresonators. We report the linear and non linear fluorescence real-time detection of labeled IgG covalently bonded to the surface of a silica whispering gallery mode resonator (WGMR). The immunoreagents have been immobilized onto the surface of the WGMR sensor after being activated with an epoxy silane and an orienting layer. The developed immunosensor presents great potential as a robust sensing device for fast and early detection of immunoreactions. We also investigate the potential of microbubbles as nonlinear enhancement platform. The dyes used in these studies are dylight800, tetramethyl rhodamine isothiocyanate, rhodamine 6G and fluorescein. All measurements were performed in a modified confocal microscope. - Highlights: • One photon fluorescence overlaps with the semiconductor pump laser gain bandwidth. • We report on the feasibility to excite two photon fluorescence in microbubble resonators. • Our functionalization process maintains a good quality factor of the microresonator.

  13. Advanced sensing with micro-optical whispering-gallery-mode resonators

    CERN Document Server

    Righini, Giancarlo C

    2017-01-01

    This Spotlight examines an increasingly popular class of optical sensors that comprises microresonators based on the propagation of whispering gallery modes (WGMs). Several 2D and 3D WGM microresonators have already proved their capabilities as general-purpose sensors (especially as biosensors), and they have potential applications outside of research laboratories. Topics include the fundamentals of WGM propagation, types and characterization of microresonators, microfabrication issues, categories of sensing (physical, chemical, and biological), and state of the art sensors.

  14. Identifying modes of large whispering-gallery mode resonators from the spectrum and emission pattern.

    Science.gov (United States)

    Schunk, Gerhard; Fürst, Josef U; Förtsch, Michael; Strekalov, Dmitry V; Vogl, Ulrich; Sedlmeir, Florian; Schwefel, Harald G L; Leuchs, Gerd; Marquardt, Christoph

    2014-12-15

    Identifying the mode numbers in whispering-gallery mode resonators (WGMRs) is important for tailoring them to experimental needs. Here we report on a novel experimental mode analysis technique based on the combination of frequency analysis and far-field imaging for high mode numbers of large WGMRs. The radial mode numbers q and the angular mode numbers p = ℓ-m are identified and labeled via far-field imaging. The polar mode numbers ℓ are determined unambiguously by fitting the frequency differences between individual whispering gallery modes (WGMs). This allows for the accurate determination of the geometry and the refractive index at different temperatures of the WGMR. For future applications in classical and quantum optics, this mode analysis enables one to control the narrow-band phase-matching conditions in nonlinear processes such as second-harmonic generation or parametric down-conversion.

  15. Aptasensors Based on Whispering Gallery Mode Resonators

    Directory of Open Access Journals (Sweden)

    Gualtiero Nunzi Conti

    2016-07-01

    Full Text Available In this paper, we review the literature on optical evanescent field sensing in resonant cavities where aptamers are used as biochemical receptors. The combined advantages of highly sensitive whispering gallery mode resonator (WGMR-based transducers, and of the unique properties of aptamers make this approach extremely interesting in the medical field, where there is a particularly high need for devices able to provide real time diagnosis for cancer, infectious diseases, or strokes. However, despite the superior performances of aptamers compared to antibodies and WGMR to other evanescent sensors, there is not much literature combining both types of receptors and transducers. Up to now, the WGMR that have been used are silica microspheres and silicon oxynitride (SiON ring resonators.

  16. Identifying modes of large whispering-gallery mode resonators from the spectrum and emission pattern

    DEFF Research Database (Denmark)

    Schunk, Gerhard; Fuerst, Josef U.; Förtsch, Michael

    2014-01-01

    Identifying the mode numbers in whispering-gallery mode resonators (WGMRs) is important for tailoring them to experimental needs. Here we report on a novel experimental mode analysis technique based on the combination of frequency analysis and far-field imaging for high mode numbers of large WGMR...

  17. Integrated optics nano-opto-fluidic sensor based on whispering gallery modes for picoliter volume refractometry

    NARCIS (Netherlands)

    Gilardi, G.; Beccherelli, R.

    2013-01-01

    We propose and numerically investigate an integrated optics refractometric nano-opto-fluidic sensor based on whispering gallery modes in sapphire microspheres. A measurand fluid is injected in a micromachined reservoir defined in between the microsphere and an optical waveguide. The wavelength shift

  18. Frequency tuning of single photons from a whispering-gallery mode resonator to MHz-wide transitions

    DEFF Research Database (Denmark)

    Schunk, G.; Vogl, U.; Sedlmeir, F.

    2016-01-01

    photons, which is based on parametric down-conversion in a triply resonant whispering-gallery mode resonator, with alkaline transitions [Schunk et al., Optica 2015, 2, 773]. In this paper, we analyse our source in terms of phase matching, available wavelength-tuning mechanisms and applications...

  19. Microwave photonics systems based on whispering-gallery-mode resonators.

    Science.gov (United States)

    Coillet, Aurélien; Henriet, Rémi; Phan Huy, Kien; Jacquot, Maxime; Furfaro, Luca; Balakireva, Irina; Larger, Laurent; Chembo, Yanne K

    2013-08-05

    Microwave photonics systems rely fundamentally on the interaction between microwave and optical signals. These systems are extremely promising for various areas of technology and applied science, such as aerospace and communication engineering, sensing, metrology, nonlinear photonics, and quantum optics. In this article, we present the principal techniques used in our lab to build microwave photonics systems based on ultra-high Q whispering gallery mode resonators. First detailed in this article is the protocol for resonator polishing, which is based on a grind-and-polish technique close to the ones used to polish optical components such as lenses or telescope mirrors. Then, a white light interferometric profilometer measures surface roughness, which is a key parameter to characterize the quality of the polishing. In order to launch light in the resonator, a tapered silica fiber with diameter in the micrometer range is used. To reach such small diameters, we adopt the "flame-brushing" technique, using simultaneously computer-controlled motors to pull the fiber apart, and a blowtorch to heat the fiber area to be tapered. The resonator and the tapered fiber are later approached to one another to visualize the resonance signal of the whispering gallery modes using a wavelength-scanning laser. By increasing the optical power in the resonator, nonlinear phenomena are triggered until the formation of a Kerr optical frequency comb is observed with a spectrum made of equidistant spectral lines. These Kerr comb spectra have exceptional characteristics that are suitable for several applications in science and technology. We consider the application related to ultra-stable microwave frequency synthesis and demonstrate the generation of a Kerr comb with GHz intermodal frequency.

  20. Directional interacting whispering-gallery modes in coupled dielectric microdisks

    International Nuclear Information System (INIS)

    Ryu, Jung-Wan; Lee, Soo-Young; Kim, Chil-Min; Park, Young-Jai

    2006-01-01

    We study the optical interaction in a coupled dielectric microdisks by investigating the splitting of resonance positions of interacting whispering-gallery modes (WGM's) and their pattern change, depending on the distance between the microdisks. It is shown that the interaction between the WGM's with odd parity about the y axis becomes appreciable at a distance less than a wavelength and causes directional emissions of the resulting interacting WGM's. The directionality of the interacting WGM's can be understood in terms of an effective boundary deformation in ray dynamical analysis. We also discuss the oscillation of the splitting when the distance is greater than a wavelength

  1. Whispering galleries and the control of artificial atoms.

    Science.gov (United States)

    Forrester, Derek Michael; Kusmartsev, Feodor V

    2016-04-28

    Quantum computation using artificial-atoms, such as novel superconducting circuits, can be sensitively controlled by external electromagnetic fields. These fields and the self-fields attributable to the coupled artificial-atoms influence the amount of quantum correlation in the system. However, control elements that can operate without complete destruction of the entanglement of the quantum-bits are difficult to engineer. Here we investigate the possibility of using closely-spaced-linear arrays of metallic-elliptical discs as whispering gallery waveguides to control artificial-atoms. The discs confine and guide radiation through the array with small notches etched into their sides that act as scatterers. We focus on π-ring artificial-atoms, which can generate their own spontaneous fluxes. We find that the micro-discs of the waveguides can be excited by terahertz frequency fields to exhibit whispering-modes and that a quantum-phase-gate composed of π-rings can be operated under their influence. Furthermore, we gauge the level of entanglement through the concurrence measure and show that under certain magnetic conditions a series of entanglement sudden-deaths and revivals occur between the two qubits. This is important for understanding the stability and life-time of qubit operations using, for example, a phase gate in a hybrid of quantum technologies composed of control elements and artificial-atoms.

  2. All-polymer photonic sensing platform based on whispering-gallery mode microgoblet lasers

    OpenAIRE

    Wienhold, T.; Kraemmer, S.; Wondimu, S.F.; Siegle, T.; Bog, U.; Weinzierl, U.; Schmidt, S.; Becker, H.; Kalt, H.; Mappes, T.; Koeber, S.; Koos, C.

    2015-01-01

    We present an all-polymer photonic sensing platform based on whispering-gallery mode microgoblet lasers integrated into a microfluidic chip. The chip is entirely made from polymers, enabling the use of the devices as low-cost disposables. The microgoblet cavities feature quality factors exceeding 105 and are fabricated from poly(methyl methacrylate) (PMMA) using spin-coating, mask-based optical lithography, wet chemical etching, and thermal reflow. In contrast to silica-based microtoroid reso...

  3. Ultra-high Q terahertz whispering-gallery modes in a silicon resonator

    Science.gov (United States)

    Vogt, Dominik Walter; Leonhardt, Rainer

    2018-05-01

    We report on the first experimental demonstration of terahertz (THz) whispering-gallery modes (WGMs) with an ultra-high quality factor of 1.5 × 104 at 0.62 THz. The WGMs are observed in a high resistivity float zone silicon spherical resonator coupled to a sub-wavelength silica waveguide. A detailed analysis of the coherent continuous wave THz spectroscopy measurements combined with a numerical model based on Mie-Debye-Aden-Kerker theory allows us to unambiguously identify the observed higher order radial THz WGMs.

  4. Elementary modes of coupled oscillators as whispering-gallery microresonators

    Science.gov (United States)

    Banerjee, Rabin; Mukherjee, Pradip

    2015-10-01

    We obtain the elementary modes of a system of parity-time reversal (PT)-symmetric coupled oscillators with balanced loss and gain. These modes are used to give a physical picture of the phase transition recently reported [C. M. Bender, M. Gianfreda, B. Peng, S. K. Özdemir and L. Yang, Phys. Rev. A 88, 062111 (2013); L. Yang, S. K. Özdemir and B. Peng, 12th Int. Workshop and Conf. Pseudo-Hermitian Hamiltonians in Quantum Physics, Istanbul, Turkey, July 2013; B. Peng, S. K. Özdemir, F. Lei, F. Monifi, M. Gianfreda, G. L. Long, S. Fan, F. Nori, C. M. Bender and L. Yang, Nat. Phys. 10, 394 (2014)] in experiments with whispering-gallery microresonators.

  5. Silica hollow bottle resonators for use as whispering gallery mode based chemical sensors

    Science.gov (United States)

    Stoian, Razvan-Ionut; Bui, Khoa V.; Rosenberger, A. T.

    2015-12-01

    A simple three-step method for making silica hollow bottle resonators (HBRs) was developed. This procedure is advantageous because it uses commercially available materials, is cost effective, and is easy to implement. Additionally, the use of these HBRs as whispering gallery mode based chemical sensors is demonstrated by preliminary absorption sensing results in the near infrared (1580-1660 nm) using a trace gas (CH4) in air at atmospheric pressure and a dye (SDA2072) in methanol solution.

  6. Rapid 3D µ-printing of polymer optical whispering-gallery mode resonators.

    Science.gov (United States)

    Wu, Jushuai; Guo, Xin; Zhang, A Ping; Tam, Hwa-Yaw

    2015-11-16

    A novel microfabrication method for rapid printing of polymer optical whispering-gallery mode (WGM) resonators is presented. A 3D micro-printing technology based on high-speed optical spatial modulator (SLM) and high-power UV light source is developed to fabricate suspended-disk WGM resonator array using SU-8 photoresist. The optical spectral responses of the fabricated polymer WGM resonators were measured with a biconically tapered optical fiber. Experimental results reveal that the demonstrated method is very flexible and time-saving for rapid fabrication of complex polymer WGM resonators.

  7. Whispering gallery modes in two-photon fluorescence from spherical DCM dye microresonators

    Science.gov (United States)

    Mamonov, Evgeniy A.; Maydykovskiy, Anton I.; Mitetelo, Nikolai V.; Venkatakrishnarao, Dasari; Chandrasekar, Rajadurai; Murzina, Tatyana V.

    2018-03-01

    Organic microstructures are well known for their resonator properties, which bring about whispering gallery mode (WGM) excitation. Here we report on experimental evidence of the WGM in the two-photon fluorescence (TPF) of DCM dye microspheres made using the self-assembly method. The WGM excitation accompanying the overall TPF in the spectral range from 530\\div640 nm demonstrated a quality factor of approximately 102 for spheres that were several microns in diameter. The power dependence of the TPF intensity proved the second order nature of the interaction process involved.

  8. Optical sum-frequency generation in a whispering-gallery-mode resonator

    International Nuclear Information System (INIS)

    Strekalov, Dmitry V; Kowligy, Abijith S; Huang, Yu-Ping; Kumar, Prem

    2014-01-01

    We demonstrate sum-frequency generation between a telecom wavelength and the Rb D2 line, achieved through natural phase matching in a nonlinear whispering gallery mode resonator. Due to the strong optical field confinement and ultra high Q of the cavity, the process saturates already at sub-mW pump peak power, at least two orders of magnitude lower than in existing waveguide-based devices. The experimental data are in agreement with the nonlinear dynamics and phase matching theory based on spherical geometry. Our experimental and theoretical results point toward a new platform for manipulating the color and quantum states of light waves for applications such as atomic memory based quantum networking and logic operations with optical signals. (paper)

  9. Silica hollow bottle resonators for use as whispering gallery mode based chemical sensors

    International Nuclear Information System (INIS)

    Stoian, Razvan-Ionut; Bui, Khoa V; Rosenberger, A T

    2015-01-01

    A simple three-step method for making silica hollow bottle resonators (HBRs) was developed. This procedure is advantageous because it uses commercially available materials, is cost effective, and is easy to implement. Additionally, the use of these HBRs as whispering gallery mode based chemical sensors is demonstrated by preliminary absorption sensing results in the near infrared (1580–1660 nm) using a trace gas (CH 4 ) in air at atmospheric pressure and a dye (SDA2072) in methanol solution. (paper)

  10. More efficient second harmonic generation of whispering gallery modes by selective out-coupling

    OpenAIRE

    Trainor, Luke S.; Sedlmeir, Florian; Peuntinger, Christian; Schwefel, Harald G. L.

    2017-01-01

    We demonstrate second harmonic generation (SHG) in an $x$-cut congruent lithium niobate (LN) whispering gallery mode resonator. We first show theoretically that independent control of the coupling of the pump and signal modes is optimal for high conversion rates. A scheme based on our earlier work in Ref. [1] is then implemented experimentally to verify this. Thereby we are able to improve on the efficiency of SHG by more than an order of magnitude by selectively out-coupling using a LN prism...

  11. Whispering Gallery Mode Based Optical Fiber Sensor for Measuring Concentration of Salt Solution

    Directory of Open Access Journals (Sweden)

    Chia-Chin Chiang

    2013-01-01

    Full Text Available An optical fiber solution-concentration sensor based on whispering gallery mode (WGM is proposed in this paper. The WGM solution-concentration sensors were used to measure salt solutions, in which the concentrations ranged from 1% to 25% and the wavelength drifted from the left to the right. The experimental results showed an average sensitivity of approximately 0.372 nm/% and an R2 linearity of 0.8835. The proposed WGM sensors are of low cost, feasible for mass production, and durable for solution-concentration sensing.

  12. Two-photon excited whispering-gallery mode ultraviolet laser from an individual ZnO microneedle

    Science.gov (United States)

    Zhu, G. P.; Xu, C. X.; Zhu, J.; Lv, C. G.; Cui, Y. P.

    2009-02-01

    Wurtzite structural ZnO microneedles with hexagonal cross section were fabricated by vapor-phase transport method and an individual microneedle was employed as a lasing microcavity. Under excitation of a femtosecond pulse laser with 800 nm wavelength, the ultraviolet (UV) laser emission was obtained, which presented narrow linewidth and high Q value. The UV emission, resonant mechanism, and laser mode characteristics were discussed in detail. The results demonstrated that the UV laser originated from the whispering-gallery mode induced by two-photon absorption assisted by Rabi oscillation.

  13. Controlled assembly of organic whispering-gallery-mode microlasers as highly sensitive chemical vapor sensors.

    Science.gov (United States)

    Gao, Miaomiao; Wei, Cong; Lin, Xianqing; Liu, Yuan; Hu, Fengqin; Zhao, Yong Sheng

    2017-03-09

    We demonstrate the fabrication of organic high Q active whispering-gallery-mode (WGM) resonators from π-conjugated polymer by a controlled emulsion-solvent-evaporation method, which can simultaneously provide optical gain and act as an effective resonant cavity. By measuring the shift of their lasing modes on exposure to organic vapor, we successfully monitored the slight concentration variation in the chemical gas. These microlaser sensors demonstrated high detection sensitivity and good signal repeatability under continuous chemical gas treatments. The results offer an effective strategy to design miniaturized optical sensors.

  14. Surface-Enhanced Raman Scattering Using Silica Whispering-Gallery Mode Resonators

    Science.gov (United States)

    Anderson, Mark S.

    2013-01-01

    The motivation of this work was to have robust spectroscopic sensors for sensitive detection and chemical analysis of organic and molecular compounds. The solution is to use silica sphere optical resonators to provide surface-enhanced spectroscopic signal. Whispering-gallery mode (WGM) resonators made from silica microspheres were used for surface-enhanced Raman scattering (SERS) without coupling to a plasmonic mechanism. Large Raman signal enhancement is observed by exclusively using 5.08-micron silica spheres with 785-nm laser excitation. The advantage of this non-plasmonic approach is that the active substrate is chemically inert silica, thermally stable, and relatively simple to fabricate. The Raman signal enhancement is broadly applicable to a wide range of molecular functional groups including aliphatic hydrocarbons, siloxanes, and esters. Applications include trace organic analysis, particularly for in situ planetary instruments that require robust sensors with consistent response.

  15. Low-Threshold Optical Parametric Oscillations in a Whispering Gallery Mode Resonator

    DEFF Research Database (Denmark)

    Fürst, J. U.; Strekalov, D. V.; Elser, D.

    2010-01-01

    In whispering gallery mode (WGM) resonator light is guided by continuous total internal reflection along a curved surface. Fabricating such resonators from an optically nonlinear material one takes advantage of their exceptionally high quality factors and small mode volumes to achieve extremely...... efficient optical frequency conversion. Our analysis of the phase-matching conditions for optical parametric down-conversion (PDC) in a spherical WGM resonator shows their direct relation to the sum rules for photons' angular momenta and predicts a very low parametric oscillation threshold. We realized...... such an optical parametric oscillator (OPO) based on naturally phase-matched PDC in lithium niobate. We demonstrated a single-mode, strongly nondegenerate OPO with a threshold of 6.7  μW and linewidth under 10 MHz. This work demonstrates the remarkable capabilities of WGM-based OPOs....

  16. High resolution terahertz spectroscopy of a whispering gallery mode bubble resonator using Hilbert analysis.

    Science.gov (United States)

    Vogt, Dominik Walter; Leonhardt, Rainer

    2017-07-10

    We report on data processing for continuous wave (CW) terahertz (THz) spectroscopy measurements based on a Hilbert spectral analysis to achieve MHz resolution. As an example we investigate the spectral properties of a whispering gallery mode (WGM) THz bubble resonator at critical coupling. The experimental verification clearly demonstrates the significant advantages in relative frequency resolution and required acquisition time of the proposed method over the traditional data analysis. An effective frequency resolution, only limited by the precision and stability of the laser beat signal, can be achieved without complex extensions to a standard commercially available CW THz spectrometer.

  17. Surface plasmon-enhanced two-photon excited whispering-gallery modes ultraviolet laser from Zno microwire

    Directory of Open Access Journals (Sweden)

    Yunpeng Wang

    2017-11-01

    Full Text Available The two-photon excited UV laser with narrow line width and high Q value was obtained. The total internal reflection from the four side surfaces of the quadrilateral-ZnO microwire offered the whispering gallery mode (WGM resonant cavity. The UV emission, resonant mechanism, and laser mode characteristics were discussed in detail for this special type of micro-cavity. In addition, in order to enhance the power of the two-photon excited UV laser, the surface plasmon enhancement by the Au nanoparticles was also performed and explained well by the theory of the localized surface plasmon.

  18. THz Pyro-Optical Detector Based on LiNbO3 Whispering Gallery Mode Microdisc Resonator

    Science.gov (United States)

    Cosci, Alessandro; Cerminara, Matteo; Nunzi Conti, Gualtiero; Soria, Silvia; Righini, Giancarlo C.; Pelli, Stefano

    2017-01-01

    This study analyzes the capabilities of a LiNbO3 whispering gallery mode microdisc resonator as a potential bolometer detector in the THz range. The resonator is theoretically characterized in the stationary regime by its thermo-optic and thermal coefficients. Considering a Q-factor of 107, a minimum detectable power of 20 μW was evaluated, three orders of magnitude above its noise equivalent power. This value opens up the feasibility of exploiting LiNbO3 disc resonators as sensitive room-temperature detectors in the THz range. PMID:28134857

  19. Wavelength shift in a whispering gallery microdisk due to bacterial sensing: A theoretical approach

    Directory of Open Access Journals (Sweden)

    Hala Ghali

    2017-04-01

    Full Text Available Whispering gallery mode microcavities have recently been studied as a means to achieve real-time label-free detection of biological targets such as virus particles, specific DNA sequences, or proteins. Binding of a biomolecule to the surface of a microresonator will increase its path length, leading to a shift in the resonance frequency according to the reactive sensing principle. In this paper, we develop a theoretical expression that will link the reactive shift to the bacteria and microdisk parameters and help quantify the number of bacteria that bind to the surface of a 200μm-diameter silica microdisk. Keywords: Optical microdisk, Wavelength shift, Bacterial sensing

  20. Quantification of whispering gallery mode spectrum variability in application to sensing nanobiophotonics

    Science.gov (United States)

    Saetchnikov, Anton; Skakun, Victor; Saetchnikov, Vladimir; Tcherniavskaia, Elina; Ostendorf, Andreas

    2017-10-01

    An approach for the automated whispering gallery mode (WGM) signal decomposition and its parameter estimation is discussed. The algorithm is based on the peak picking and can be applied for the preprocessing of the raw signal acquired from the multiplied WGM-based biosensing chips. Quantitative estimations representing physically meaningful parameters of the external disturbing factors on the WGM spectral shape are the output values. Derived parameters can be directly applied to the further deep qualitative and quantitative interpretations of the sensed disturbing factors. The algorithm is tested on both simulated and experimental data taken from the bovine serum albumin biosensing task. The proposed solution is expected to be a useful contribution to the preprocessing phase of the complete data analysis engine and is expected to push the WGM technology toward the real-live sensing nanobiophotonics.

  1. Whispering-gallery-mode resonance sensor for dielectric sensing of drug tablets

    International Nuclear Information System (INIS)

    Neshat, Mohammad; Chen, Huanyu; Safavi-Naeini, Safieddin; Gigoyan, Suren; Saeedkia, Daryoosh

    2010-01-01

    We propose, for the first time, the application of whispering gallery mode (WGM) perturbation technique in dielectric analysis of disk shape pharmaceutical tablets. Based on WGM resonance, a low-cost high sensitivity sensor in milllimeter-wave frequency range is presented. A comprehensive sensitivity analysis was performed to show that a change in the order of 10 −4 in the sample permittivity can be detected by the proposed sensor. The results of various experiments carried out on drug tablets are reported to demonstrate the potential multifunctional capabilities of the sensor in moisture sensing, counterfeit drug detection and contamination screening. Analytically, two sample placement configurations, i.e. a tablet placed on top of a dielectric disk resonator and inside a dielectric ring resonator, have been studied to predict the resonance frequency and Q-factor of the combined sample-resonator structure. The accuracy of the analytical model was tested against full-wave simulations and experimental data

  2. Influence of the whispering-gallery mode resonators shape on its inertial movement sensitivity

    Science.gov (United States)

    Filatov, Yuri V.; Kukaev, Alexander S.; Shalymov, Egor V.; Venediktov, Vladimir Yu.

    2018-01-01

    The optical whispering-gallery mode (WGM) resonators are axially symmetrical resonators with smooth edges, supporting the existence of the WGMs by the total internal reflection on the surface of the resonator. As of today, various types of such resonators have been developed, namely the ball shaped, tor shaped, bottle shaped, disk shaped, etc. The movement of WGM resonators in inertial space causes the changes in their shape. The result is a spectral shift of the WGMs. Optical methods allow to register this shift with high precision. It can be used in particular for the measurement of angular velocities in inertial orientation and navigation systems. However, different types of resonators react to the movement in different manners. In addition, their sensitivity to movement can be changed when changing the geometric parameters of these resonators. The work is devoted to investigation of these aspects.

  3. Tunable waveguide and cavity in a phononic crystal plate by controlling whispering-gallery modes in hollow pillars

    DEFF Research Database (Denmark)

    Jin, Yabin; Fernez, Nicolas; Pennec, Yan

    2016-01-01

    We investigate the properties of a phononic crystal plate with hollow pillars and introduce the existence of whispering-gallery modes (WGMs). We show that by tuning the inner radius of the hollow pillar, these modes can merge inside both Bragg and low frequency band gaps, deserving phononic crystal...... and acoustic metamaterial applications. These modes can be used as narrow pass bands for which the quality factor can be greatly enhanced by the introduction of an additional cylinder between the hollow cylinder and the plate. We discuss some functionalities of these confined WGM in both Bragg and low...

  4. Fano resonances in a high-Q terahertz whispering-gallery mode resonator coupled to a multi-mode waveguide.

    Science.gov (United States)

    Vogt, Dominik Walter; Leonhardt, Rainer

    2017-11-01

    We report on Fano resonances in a high-quality (Q) whispering-gallery mode (WGM) spherical resonator coupled to a multi-mode waveguide in the terahertz (THz) frequency range. The asymmetric line shape and phase of the Fano resonances detected with coherent continuous-wave (CW) THz spectroscopy measurements are in excellent agreement with the analytical model. A very high Q factor of 1600, and a finesse of 22 at critical coupling is observed around 0.35 THz. To the best of our knowledge this is the highest Q factor ever reported for a THz WGM resonator.

  5. Photoluminescence and lasing in whispering gallery mode glass microspherical resonators

    Energy Technology Data Exchange (ETDEWEB)

    Ristić, D. [Ruđer Bošković Institute, Division of Materials Physics, Laboratory for Molecular Physics, Bijenička c. 54, Zagreb (Croatia); Center of Excellence for Advanced Materials and Sensing Devices, Research unit New Functional Materials, Bijenička c. 54, Zagreb (Croatia); Berneschi, S.; Camerini, M. [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Farnesi, D.; Pelli, S. [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Centro Studi e Ricerche ' E. Fermi' , Piazza del Viminale 2, 00184 Roma (Italy); Trono, C. [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Chiappini, A.; Chiasera, A.; Ferrari, M. [CSMFO Group, Istituto di Fotonica e Nanotecnologie, IFN-CNR, Via alla Cascata 56/C, 38050 Povo-Trento (Italy); Lukowiak, A. [Institute of Low Temperature and Structure Research, PAS, ul. Okolna 2, Wroclaw 50-950 (Poland); Dumeige, Y.; Féron, P. [Laboratoire d' Optronique, (CNRS-UMR 6082-Foton), ENSSAT, 6 rue de Kérampont, 22300 Lannion (France); Righini, G.C. [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Centro Studi e Ricerche ' E. Fermi' , Piazza del Viminale 2, 00184 Roma (Italy); Soria, S., E-mail: s.soria@ifac.cnr.it [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Conti, G. Nunzi [IFAC-CNR Istituto di Fisica Applicata, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Italy); Centro Studi e Ricerche ' E. Fermi' , Piazza del Viminale 2, 00184 Roma (Italy)

    2016-02-15

    We report experimental results regarding the development of Er{sup 3+}-doped glass microspherical cavities for the fabrication of compact sources at 1.55 μm. We investigate several different approaches in order to fabricate the microspheres including direct melting of Er{sup 3+}-doped glass powders, synthesis of Er{sup 3+}-doped monolithic microspheres by drawing Er{sup 3+}-doped glass, and coating of silica microspheres with an Er{sup 3+}-doped sol–gel layer. Details of the different fabrication processes are presented together with the photoluminescence characterization in free space configuration of the microspheres and of the glass precursor. We have analyzed the photoluminescence spectra of the whispering gallery modes of the microspheres excited using evanescent coupling and we demonstrate tunable laser action in a wide range of wavelengths around 1.55 μm. As much as 90 μW of laser output power was measured in Er{sup 3+}-doped glass microspheres. - Highlights: • Different approaches in microsphere fabrication and various types of post-processing. • Trimming of photorefractive glass microsphere lasers with UV light. • Peak power record of 90 μW by pumping at 1480 nm.

  6. Integrated optics nano-opto-fluidic sensor based on whispering gallery modes for picoliter volume refractometry

    International Nuclear Information System (INIS)

    Gilardi, Giovanni; Beccherelli, Romeo

    2013-01-01

    We propose and numerically investigate an integrated optics refractometric nano-opto-fluidic sensor based on whispering gallery modes in sapphire microspheres. A measurand fluid is injected in a micromachined reservoir defined in between the microsphere and an optical waveguide. The wavelength shift due to changes in the refractive index of the measurand fluid are studied for a set of different configurations by the finite element method and a high sensitivity versus fluid volume is found. The proposed device can be tailored to work with a minimum fluid volume of 1 pl and a sensitivity up of 2000 nm/(RIU·nl). We introduce a figure of merit which quantifies the amplifying effect on the sensitivity of high quality factor resonators and allows us to compare different devices. (paper)

  7. Split-disk micro-lasers: Tunable whispering gallery mode cavities

    Directory of Open Access Journals (Sweden)

    T. Siegle

    2017-09-01

    Full Text Available Optical micro-cavities of various types have emerged as promising photonic structures, for both the investigation of fundamental science in cavity quantum electrodynamics and simultaneously for various applications, e.g., lasers, filters, or modulators. In either branch a demand for adjustable and tunable photonic devices becomes apparent, which has been mainly based on the modification of the refractive index of the micro-resonators so far. In this paper, we report on a novel type of whispering gallery mode resonator where resonance tuning is achieved by modification of the configuration. This is realized by polymeric split-disks consisting of opposing half-disks with an intermediate air gap. Functionality of the split-disk concept and its figures of merit like low-threshold lasing are demonstrated for laser dye-doped split-disks fabricated by electron beam lithography on Si substrates. Reversible resonance tuning is achieved for split-disks structured onto elastomeric substrates by direct laser writing. The gap width and hence the resonance wavelength can be well-controlled by mechanically stretching the elastomer and exploiting the lateral shrinkage of the substrate. We demonstrate a broad spectral tunability of laser modes by more than three times the free spectral range. These cavities have the potential to form a key element of flexible and tunable photonic circuits based on polymers.

  8. Coupling single NV-centres to high-Q whispering gallery modes of a preselected frequency-matched microresonator

    International Nuclear Information System (INIS)

    Schietinger, Stefan; Benson, Oliver

    2009-01-01

    In this paper, we report the controlled coupling of fluorescence from a single NV-centre in a single nanodiamond to the high-Q modes of a preselected microsphere. Microspheres from an ensemble with a finite size distribution can be characterized precisely via white light Mie-scattering. The mode spectrum of individual spheres can be determined with high precision. A sphere with an appropriate spectrum can be selected, and a nanodiamond containing a single NV-centre can be coupled to it. The spectral position of the calculated lowest order whispering gallery modes are found to be in very good agreement with the experimentally observed resonances of the coupled fluorescence from the single NV-re.

  9. Simulation of whispering-gallery-mode resonance shifts for optical miniature biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Quan Haiyong [Department of Mechanical and Aerospace Engineering, Rutgers, State University of New Jersey, 98 Brett Road, Piscataway, NJ 08854 (United States); Guo Zhixiong [Department of Mechanical and Aerospace Engineering, Rutgers, State University of New Jersey, 98 Brett Road, Piscataway, NJ 08854 (United States)]. E-mail: guo@jove.rutgers.edu

    2005-06-15

    Finite element analyses are made of the shifts of resonance frequencies of whispering-gallery-mode (WGM) for a fiber-microsphere coupling miniature sensor. The time-domain Maxwell's equations were adopted to describe the near-field radiation transport and solved by the in-plane TE waves application mode of the FEMLAB. The electromagnetic fields as well as the radiation energy distributions can be easily obtained by the finite element analysis. The resonance intensity spectrum curves in the frequency range from 213 to 220THz were studied under different biosensing conditions. Emphasis was put on the analyses of resonance shift sensitivity influenced by changes of the effective size of the sensor resonator (i.e., microsphere) and/or the refractive index of the medium surrounding the resonator. It is estimated that the WGM biosensor can distinguish molecular size change to the level of 0.1nm and refractive index change in the magnitude of {approx}10{sup -3} even with the use of a general optical spectrum analyzer of one GHz linewidth. Finally, the potential of the WGM miniature biosensor for monitoring peptide growth is investigated and a linear sensor curve is obtained.

  10. Real-Time Detection of Staphylococcus Aureus Using Whispering Gallery Mode Optical Microdisks

    Directory of Open Access Journals (Sweden)

    Hala Ghali

    2016-05-01

    Full Text Available Whispering Gallery Mode (WGM microresonators have recently been studied as a means to achieve real-time label-free detection of biological targets such as virus particles, specific DNA sequences, or proteins. Due to their high quality (Q factors, WGM resonators can be highly sensitive. A biosensor also needs to be selective, requiring proper functionalization of its surface with the appropriate ligand that will attach the biomolecule of interest. In this paper, WGM microdisks are used as biosensors for detection of Staphylococcus aureus. The microdisks are functionalized with LysK, a phage protein specific for staphylococci at the genus level. A binding event on the surface shifts the resonance peak of the microdisk resonator towards longer wavelengths. This reactive shift can be used to estimate the surface density of bacteria that bind to the surface of the resonator. The limit of detection of a microdisk with a Q-factor around 104 is on the order of 5 pg/mL, corresponding to 20 cells. No binding of Escherichia coli to the resonators is seen, supporting the specificity of the functionalization scheme.

  11. Optothermal transport behavior in whispering gallery mode optical cavities

    Energy Technology Data Exchange (ETDEWEB)

    Soltani, Soheil [Ming Hsieh Department of Electrical Engineering-Electrophysics, University of Southern California, Los Angeles, California 90089 (United States); Armani, Andrea M., E-mail: armani@usc.edu [Ming Hsieh Department of Electrical Engineering-Electrophysics, University of Southern California, Los Angeles, California 90089 (United States); Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089 (United States)

    2014-08-04

    Over the past century, whispering gallery mode optical cavities have enabled numerous advances in science and engineering, such as discoveries in quantum mechanics and non-linear optics, as well as the development of optical gyroscopes and add drop filters. One reason for their widespread appeal is their ability to confine light for long periods of time, resulting in high circulating intensities. However, when sufficiently large amounts of optical power are coupled into these cavities, they begin to experience optothermal or photothermal behavior, in which the optical energy is converted into heat. Above the optothermal threshold, the resonance behavior is no longer solely defined by electromagnetics. Previous work has primarily focused on the role of the optothermal coefficient of the material in this instability. However, the physics of this optothermal behavior is significantly more complex. In the present work, we develop a predictive theory based on a generalizable analytical expression in combination with a geometry-specific COMSOL Multiphysics finite element method model. The simulation couples the optical and thermal physics components, accounting for geometry variations as well as the temporal and spatial profile of the optical field. To experimentally verify our theoretical model, the optothermal thresholds of a series of silica toroidal resonant cavities are characterized at different wavelengths (visible through near-infrared) and using different device geometries. The silica toroid offers a particularly rigorous case study for the developed optothermal model because of its complex geometrical structure which provides multiple thermal transport paths.

  12. Hyperparametric effects in a whispering-gallery mode rutile dielectric resonator at liquid helium temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Nand, Nitin R.; Goryachev, Maxim; Floch, Jean-Michel le; Creedon, Daniel L.; Tobar, Michael E. [ARC Centre for Engineered Quantum Systems, School of Physics, The University of Western Australia, 35 Stirling Highway, Crawley 6009, Western Australia (Australia)

    2014-10-07

    We report the first observation of low power drive level sensitivity, hyperparametric amplification, and single-mode hyperparametric oscillations in a dielectric rutile whispering-gallery mode resonator at 4.2 K. The latter gives rise to a comb of sidebands at 19.756 GHz. Whereas, most frequency combs in the literature have been observed in optical systems using an ensemble of equally spaced modes in microresonators or fibers, the present work represents generation of a frequency comb using only a single-mode. The experimental observations are explained by an additional 1/2 degree-of-freedom originating from an intrinsic material nonlinearity at optical frequencies, which affects the microwave properties due to the extremely low loss of rutile. Using a model based on lumped circuits, we demonstrate that the resonance between the photonic and material 1/2 degree-of-freedom, is responsible for the hyperparametric energy transfer in the system.

  13. Light-controlled microwave whispering-gallery-mode quasi-optical resonators at 50W LED array illumination

    Directory of Open Access Journals (Sweden)

    V. B. Yurchenko

    2015-08-01

    Full Text Available We present experimental observations of light-controlled resonance effects in microwave whispering-gallery-mode quasi-optical dielectric-semiconductor disk resonators in the frequency band of 5 GHz to 20 GHz arising due to illumination from a light emitting diode (LED of 50W power range. We obtain huge enhancement of photo-sensitivity (growing with the resonator Q-factor that makes light-microwave interaction observable with an ordinary light (no laser at conventional brightness (like an office lighting in quasi-optical microwave structures at rather long (centimeter-scale wavelength. We also demonstrate non-conventional photo-response of Fano resonances when the light suppresses one group of resonances and enhances another group. The effects could be used for the optical control and quasi-optical switching of microwave propagation through either one or another frequency channel.

  14. Strain tuneable whispering gallery mode resonators in the estimation of the elasto-optic parameters of soft materials

    Science.gov (United States)

    Pissadakis, Stavros; Milenko, Karolina; Aluculesei, Alina; Fytas, George

    2016-04-01

    In this manuscript we present the fabrication and characterization of a novel, polymer whispering gallery modes (WGMs) spherical micro-resonator, formed around the waist of an optical fiber taper. Fiber taper with well attached spheroid works as a cord, fixed on two ends enabling strain application to the resonator body. Controllable elastic elongation of the encapsulated fiber taper causes a change in the shape of the spheroid, which modifies the diameter and directional refractive index of the cavity. These changes influence the wavelength position of the WGMs resonances with a linear blue shift up to 0.6 nm, with corresponding strains up to 700Μɛ. The strain induced WGMs shift with respect to resonator diameter and annealing process is presented and analyzed.

  15. Giant thermo-optical relaxation oscillations in millimeter-size whispering gallery mode disk resonators.

    Science.gov (United States)

    Diallo, Souleymane; Lin, Guoping; Chembo, Yanne K

    2015-08-15

    In this Letter, we show that giant thermo-optical oscillations can be triggered in millimeter (mm)-size whispering gallery mode (WGM) disk resonators when they are pumped by a resonant continuous-wave laser. Our resonator is an ultrahigh-Q barium fluoride cavity that features a positive thermo-optic coefficient and a negative thermo-elastic coefficient. We demonstrate for the first time, to our knowledge, that the complex interplay between these two thermic coefficients and the intrinsic Kerr nonlinearity yields very sharp slow-fast relaxation oscillations with a slow timescale that can be exceptionally large, typically of the order of 1 s. We use a time-domain model to gain understanding into this instability, and we find that both the experimental and theoretical results are in excellent agreement. The understanding of these thermal effects is an essential requirement for every WGM-related application and our study demonstrates that even in the case of mm-size resonators, such effects can still be accurately analyzed using nonlinear time-domain models.

  16. Formation of whispering gallery modes by scattering of an electromagnetic plane wave by two cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Abramov, Arnold, E-mail: qulaser@gmail.com [Kuang-Chi Institute of Advanced Technology, Shenzhen, 518057 (China); Kostikov, Alexander [Donbass State Engineering Academy, 84303, Kramatorsk, Donetsk (Ukraine)

    2017-03-26

    We report the effect of scattering of electromagnetic plane waves by two cylinders on whispering gallery mode (WGM) formation in a cylinder. WGM can occur because of the presence of additional cylinder scatterers at specific location, while WGMs can only form in a single cylinder for specific cylinder radius and/or wavelength values, the matching accuracy required would be much greater than that required in our model for the additional cylinders locations. Analysis of the general solution to the problem showed that the effect can be explained by the interference of waves scattered by additional cylinders and incident on the main cylinder. - Highlights: • We consider scattering of electromagnetic plane waves by two cylinders. • WGMs occur because of the presence of additional cylinder at specific location. • The accuracy for the locations is much less than required for specific values of single cylinder. • The interference of waves scattered by additional cylinders and incident on the main is responsible for the effect.

  17. Whispering Gallery Mode Resonances from Ge Micro-Disks on Suspended Beams

    Directory of Open Access Journals (Sweden)

    Abdelrahman Zaher Al-Attili

    2015-05-01

    Full Text Available Ge is considered to be one of the most promising materials for realizing full monolithic integration of a light source on a silicon (Si photonic chip. Tensile-strain is required to convert Ge into an optical gain material and to reduce the pumping required for population inversion. Several methods of strain application to Ge are proposed in literature, of which the use of free-standing beams fabricated by micro-electro-mechanical systems (MEMS processes are capable of delivering very high strain values. However, it is challenging to make an optical cavity within free-standing Ge beams, and here, we demonstrate the fabrication of a simple cavity while imposing tensile strain by suspension using Ge-On-Insulator (GOI wafers. Ge micro-disks are made on top of suspended SiO$_{2}$ beams by partially removing the supporting Si substrate. According to Raman spectroscopy, a slight tensile strain was applied to the Ge disks through the bending of the SiO2 beams. Whispering-Gallery-Mode (WGM resonances were observed from a disk with a diameter of 3um, consistent with the finite-domain time-difference simulations. The quality (Q factor was 192, and upon increasing the pumping power, the Q-factor was degraded due to the red-shift of Ge direct-gap absorption edge caused by heating.

  18. The Detection of Helicobacter hepaticus Using Whispering-Gallery Mode Microcavity Optical Sensors

    Directory of Open Access Journals (Sweden)

    Mark E. Anderson

    2015-08-01

    Full Text Available Current bacterial detection techniques are relatively slow, require bulky instrumentation, and usually require some form of specialized training. The gold standard for bacterial detection is culture testing, which can take several days to receive a viable result. Therefore, simpler detection techniques that are both fast and sensitive could greatly improve bacterial detection and identification. Here, we present a new method for the detection of the bacteria Helicobacter hepaticus using whispering-gallery mode (WGM optical microcavity-based sensors. Due to minimal reflection losses and low material adsorption, WGM-based sensors have ultra-high quality factors, resulting in high-sensitivity sensor devices. In this study, we have shown that bacteria can be non-specifically detected using WGM optical microcavity-based sensors. The minimum detection for the device was 1 × 104 cells/mL, and the minimum time of detection was found to be 750 s. Given that a cell density as low as 1 × 103 cells/mL for Helicobacter hepaticus can cause infection, the limit of detection shown here would be useful for most levels where Helicobacter hepaticus is biologically relevant. This study suggests a new approach for H. hepaticus detection using label-free optical sensors that is faster than, and potentially as sensitive as, standard techniques.

  19. Electrically tunable whispering gallery mode microresonator based on a grapefruit-microstructured optical fiber infiltrated with nematic liquid crystals.

    Science.gov (United States)

    Yang, Chengkun; Zhang, Hao; Liu, Bo; Lin, Shiwei; Li, Yuetao; Liu, Haifeng

    2017-08-01

    An electrically tunable whispering gallery mode (WGM) microresonator based on an HF-etched microstructured optical fiber (MOF) infiltrated with nematic liquid crystals (NLCs) is proposed and experimentally demonstrated. Experimental results indicate that as the peak-to-peak voltage of the applied AC electric field increases from 160 to 220 V, WGM resonance peaks gradually move toward a shorter wavelength region by 0.527 nm with a wavelength sensitivity up to 0.01  nm/V for a TM1691 mode, and the Q-factor for each WGM resonance peak rapidly decreases with the increment of applied electric voltage. The proposed electrically controlled WGM tuning scheme shows a linear resonance wavelength shift with good spectral reversibility, which makes it a promising candidate to serve as an integrated functional photonic device in practical use and in related fundamental scientific studies.

  20. Using Whispering-Gallery-Mode Resonators for Refractometry

    Science.gov (United States)

    Matsko, Andrey; Savchenkov, Anatoliy; Strekalov, Dmitry; Iltchenko, Vladimir; Maleki, Lute

    2010-01-01

    A method of determining the refractive and absorptive properties of optically transparent materials involves a combination of theoretical and experimental analysis of electromagnetic responses of whispering-gallery-mode (WGM) resonator disks made of those materials. The method was conceived especially for use in studying transparent photorefractive materials, for which purpose this method affords unprecedented levels of sensitivity and accuracy. The method is expected to be particularly useful for measuring temporally varying refractive and absorptive properties of photorefractive materials at infrared wavelengths. Still more particularly, the method is expected to be useful for measuring drifts in these properties that are so slow that, heretofore, the properties were assumed to be constant. The basic idea of the method is to attempt to infer values of the photorefractive properties of a material by seeking to match (1) theoretical predictions of the spectral responses (or selected features thereof) of a WGM of known dimensions made of the material with (2) the actual spectral responses (or selected features thereof). Spectral features that are useful for this purpose include resonance frequencies, free spectral ranges (differences between resonance frequencies of adjacently numbered modes), and resonance quality factors (Q values). The method has been demonstrated in several experiments, one of which was performed on a WGM resonator made from a disk of LiNbO3 doped with 5 percent of MgO. The free spectral range of the resonator was approximately equal to 3.42 GHz at wavelengths in the vicinity of 780 nm, the smallest full width at half maximum of a mode was approximately equal to 50 MHz, and the thickness of the resonator in the area of mode localization was 30 microns. In the experiment, laser power of 9 mW was coupled into the resonator with an efficiency of 75 percent, and the laser was scanned over a frequency band 9 GHz wide at a nominal wavelength of

  1. Biochemical component identification by plasmonic improved whispering gallery mode optical resonance based sensor

    Science.gov (United States)

    Saetchnikov, Vladimir A.; Tcherniavskaia, Elina A.; Saetchnikov, Anton V.; Schweiger, Gustav; Ostendorf, Andreas

    2014-05-01

    Experimental data on detection and identification of variety of biochemical agents, such as proteins, microelements, antibiotic of different generation etc. in both single and multi component solutions under varied in wide range concentration analyzed on the light scattering parameters of whispering gallery mode optical resonance based sensor are represented. Multiplexing on parameters and components has been realized using developed fluidic sensor cell with fixed in adhesive layer dielectric microspheres and data processing. Biochemical component identification has been performed by developed network analysis techniques. Developed approach is demonstrated to be applicable both for single agent and for multi component biochemical analysis. Novel technique based on optical resonance on microring structures, plasmon resonance and identification tools has been developed. To improve a sensitivity of microring structures microspheres fixed by adhesive had been treated previously by gold nanoparticle solution. Another technique used thin film gold layers deposited on the substrate below adhesive. Both biomolecule and nanoparticle injections caused considerable changes of optical resonance spectra. Plasmonic gold layers under optimized thickness also improve parameters of optical resonance spectra. Biochemical component identification has been also performed by developed network analysis techniques both for single and for multi component solution. So advantages of plasmon enhancing optical microcavity resonance with multiparameter identification tools is used for development of a new platform for ultra sensitive label-free biomedical sensor.

  2. Toward Automatic Label-Free Whispering Gallery Modes Biodetection with a Quantum Dot-Coated Microsphere Population

    Directory of Open Access Journals (Sweden)

    Boissinot K

    2010-01-01

    Full Text Available Abstract We explore a new calibration-free approach to biodetection based on whispering gallery modes (WGMs without a reference measure and relative shifts. Thus, the requirement to keep track of the sensor position is removed, and a freely moving population of fluorophore-doped polystyrene microspheres can now fulfill this role of sensing resonator. Breaking free from fixed surface-based biosensing promotes adhesion between the microsphere sensors and the analytes since both can now be thoroughly mixed. The 70-nm-wide spectrum of green fluorescent microbeads allows us to monitor over 20 WGMs simultaneously without needing evanescent light coupling into the microspheres, hence enabling remote sensing. Since the exact radius of each microsphere is unknown a priori, it requires algorithmic analyses to obtain a reliable result for the refractive index of a solution. We first test our approach with different solutions of alcohol in water obtaining 3 × 10−4 precision on the refractive index at lower concentrations. Then, the solutions of bacterial spores in water yield clear evidence of biodetection in the statistical analysis of WGMs from 50 microspheres. To extend the fluorescence spectral range of our WGM sensors, we present preliminary results on coating microspheres with CdSe/ZnS quantum dots.

  3. Whispering gallery mode resonators for frequency metrology applications

    Science.gov (United States)

    Baumgartel, Lukas

    This dissertation describes an investigation into the use of whispering gallery mode (WGM) resonators for applications towards frequency reference and metrology. Laser stabilization and the measurement of optical frequencies have enabled myriad technologies of both academic and commercial interest. A technology which seems to span both motivations is optical atomic clocks. These devices are virtually unimaginable without the ultra stable lasers plus frequency measurement and down-conversion afforded by Fabry Perot (FP) cavities and model-locked laser combs, respectively. However, WGM resonators can potentially perform both of these tasks while having the distinct advantages of compactness and simplicity. This work represents progress towards understanding and mitigating the performance limitations of WGM cavities for such applications. A system for laser frequency stabilization to a the cavity via the Pound-Drever-Hall (PDH) method is described. While the laser lock itself is found to perform at the level of several parts in 1015, a variety of fundamental and technical mechanisms destabilize the WGM frequency itself. Owing to the relatively large thermal expansion coefficients in optical crystals, environmental temperature drifts set the stability limit at time scales greater than the thermal relaxation time of the crystal. Uncompensated, these drifts pull WGM frequencies about 3 orders of magnitude more than they would in an FP cavity. Thus, two temperature compensation schemes are developed. An active scheme measures and stabilizes the mode volume temperature to the level of several nK, reducing the effective temperature coefficient of the resonator to 1.7x10-7 K-1; simulations suggest that the value could eventually be as low as 3.5x10-8 K-1, on par with the aforementioned FP cavities. A second, passive scheme is also described, which employs a heterogeneous resonator structure that capitalizes on the thermo-mechanical properties of one material and the optical

  4. Construction of high-dimensional universal quantum logic gates using a Λ system coupled with a whispering-gallery-mode microresonator.

    Science.gov (United States)

    He, Ling Yan; Wang, Tie-Jun; Wang, Chuan

    2016-07-11

    High-dimensional quantum system provides a higher capacity of quantum channel, which exhibits potential applications in quantum information processing. However, high-dimensional universal quantum logic gates is difficult to achieve directly with only high-dimensional interaction between two quantum systems and requires a large number of two-dimensional gates to build even a small high-dimensional quantum circuits. In this paper, we propose a scheme to implement a general controlled-flip (CF) gate where the high-dimensional single photon serve as the target qudit and stationary qubits work as the control logic qudit, by employing a three-level Λ-type system coupled with a whispering-gallery-mode microresonator. In our scheme, the required number of interaction times between the photon and solid state system reduce greatly compared with the traditional method which decomposes the high-dimensional Hilbert space into 2-dimensional quantum space, and it is on a shorter temporal scale for the experimental realization. Moreover, we discuss the performance and feasibility of our hybrid CF gate, concluding that it can be easily extended to a 2n-dimensional case and it is feasible with current technology.

  5. Comparison of various excitation and detection schemes for dye-doped polymeric whispering gallery mode micro-lasers.

    Science.gov (United States)

    Siegle, Tobias; Kellerer, Jonas; Bonenberger, Marielle; Krämmer, Sarah; Klusmann, Carolin; Müller, Marius; Kalt, Heinz

    2018-02-05

    We compare different excitation and collection configurations based on free-space optics and evanescently coupled tapered fibers for both lasing and fluorescence emission from dye-doped doped polymeric whispering gallery mode (WGM) micro-disk lasers. The focus of the comparison is on the lasing threshold and efficiency of light collection. With the aid of optical fibers, we localize the pump energy to the cavity-mode volume and reduce the necessary pump energy to achieve lasing by two orders of magnitude. When using fibers for detection, the collection efficiency is enhanced by four orders of magnitude compared to a free-space read-out perpendicular to the resonator plane. By enhancing the collection efficiency we are able to record a pronounced modulation of the dye fluorescence under continuous wave (cw) pumping conditions evoked by coupling to the WGMs. Alternatively to fibers as a collection tool, we present a read-out technique based on the detection of in-plane radiated light. We show that this method is especially beneficial in an aqueous environment as well as for size-reduced micro-lasers where radiation is strongly pronounced. Furthermore, we show that this technique allows for the assignment of transverse electric (TE) and transverse magnetic (TM) polarization to the observed fundamental modes in a water environment by performing polarization-dependent photoluminescence (PL) spectroscopy. We emphasize the importance of the polarization determination for sensing applications and verify expected differences in the bulk refractive index sensitivity for TE and TM WGMs experimentally.

  6. Low threshold lasing of bubble-containing glass microspheres by non-whispering gallery mode excitation over a wide wavelength range

    Energy Technology Data Exchange (ETDEWEB)

    Kumagai, Tsutaru, E-mail: kumagai.t.af@m.titech.ac.jp; Kishi, Tetsuo; Yano, Tetsuji [Department of Chemistry and Materials Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)

    2015-03-21

    Bubble-containing Nd{sup 3+}-doped tellurite glass microspheres were fabricated by localized laser heating technique to investigate their optical properties for use as microresonators. Fluorescence and excitation spectra measurements were performed by pumping with a tunable CW-Ti:Sapphire laser. The excitation spectra manifested several sharp peaks due to the conventional whispering gallery mode (WGM) when the pumping laser was irradiated to the edge part of the microsphere. However, when the excitation light was irradiated on the bubble position inside the microsphere, “non-WGM excitation” was induced, giving rise to numerous peaks at a broad wavelength range in the excitation spectra. Thus, efficient excitation was achieved over a wide wavelength range. Lasing threshold excited at the bubble position was much lower than that for the excitation at the edges of the microsphere. The lowest value of the laser threshold was 34 μW for a 4 μm sphere containing a 0.5 μm bubble. Efficiency of the excitation at the bubble position with broadband light was calculated to be 5 times higher than that for the edge of the microsphere. The bubble-containing microsphere enables efficient utilization of broadband light excitation from light-emitting diodes and solar light.

  7. Mathematical Model for Electric Field Sensor Based on Whispering Gallery Modes Using Navier’s Equation for Linear Elasticity

    Directory of Open Access Journals (Sweden)

    Amir R. Ali

    2017-01-01

    Full Text Available This paper presents and verifies the mathematical model of an electric field senor based on the whispering gallery mode (WGM. The sensing element is a dielectric microsphere, where the light is used to tune the optical modes of the microsphere. The light undergoes total internal reflection along the circumference of the sphere; then it experiences optical resonance. The WGM are monitored as sharp dips on the transmission spectrum. These modes are very sensitive to morphology changes of the sphere, such that, for every minute change in the sphere’s morphology, a shift in the transmission spectrum will happen and that is known as WGM shifts. Due to the electrostriction effect, the applied electric field will induce forces acting on the surface of the dielectric sphere. In turn, these forces will deform the sphere causing shifts in its WGM spectrum. The applied electric field can be obtained by calculating these shifts. Navier’s equation for linear elasticity is used to model the deformation of the sphere to find the WGM shift. The finite element numerical studies are performed to verify the introduced model and to study the behavior of the sensor at different values of microspheres’ Young’s modulus and dielectric constant. Furthermore, the sensitivity and resolution of the developed WGM electric filed sensor model will be presented in this paper.

  8. Cavity QED experiments with a whispering-gallery-mode bottle resonator

    International Nuclear Information System (INIS)

    O'Shea, D.

    2013-01-01

    The interaction of a two-level atom with a single mode of the quantized electromagnetic field constitutes one of the most fundamental systems investigated in quantum optics. We have pursued such an investigation where rubidium atoms are strongly coupled to the modes of a whispering-gallery-mode (WGM) resonator that is itself interfaced with an optical fiber. In order to facilitate studies of this atom-light interaction, an experimental apparatus was constructed around a novel type of WGM resonator developed in our group. The spectral and spatial mode structure of this resonator yield an intriguing atom-light response arising principally from the existence of two frequency-degenerate modes. This thesis reports on high resolution experiments studying the transmission and reflection spectra of modes with a high quality factor (Q=10 7 -10 8 ) in our WGM resonator. Light is coupled into and out of WGMs by frustrated total internal reflection using an optical nanofiber. The atom-light interaction is facilitated by an atomic fountain that delivers a cloud of atoms to the location of the resonator. At random moments, single-atoms are clearly observed transiting the evanescent field of the resonator modes with a transit time of a few microseconds. A high-speed experimental control system was developed to firstly detect the coupling of individual atoms to the resonator and secondly to perform time-resolved spectroscopy on the strongly coupled atom-resonator system. Spectral measurements clearly resolve an atom-induced change in the resonant transmission of the coupled system (65% absolute change) that is much larger than predicted in the standard Jaynes-Cummings model (25% absolute change) and that has thus far not been observed. To gain further insight, we experimentally explored the properties of the interaction and performed supporting simulations. Spectroscopy was performed on the atom-resonator system using two nanofibers to in- and out-couple light for probing

  9. Discovery of iron group impurity ion spin states in single crystal Y{sub 2}SiO{sub 5} with strong coupling to whispering gallery photons

    Energy Technology Data Exchange (ETDEWEB)

    Goryachev, Maxim; Farr, Warrick G.; Carmo Carvalho, Natalia do; Creedon, Daniel L.; Le Floch, Jean-Michel [ARC Centre of Excellence for Engineered Quantum Systems, University of Western Australia, 35 Stirling Highway, Crawley WA 6009 (Australia); Probst, Sebastian [Physikalisches Institut, Karlsruhe Institute of Technology, D-76128 Karlsruhe (Germany); Bushev, Pavel [Experimentalphysik, Universität des Saarlandes, D-66123 Saarbrücken (Germany); Tobar, Michael E., E-mail: michael.tobar@uwa.edu.au [ARC Centre of Excellence for Engineered Quantum Systems, School of Physics, University of Western Australia, Crawley 6009 (Australia)

    2015-06-08

    Interaction of Whispering Gallery Modes (WGMs) with dilute spin ensembles in solids is an interesting paradigm of Hybrid Quantum Systems potentially beneficial for Quantum Signal Processing applications. Unexpected ion transitions are measured in single crystal Y{sub 2}SiO{sub 5} using WGM spectroscopy with large Zero Field Splittings at 14.7 GHz, 18.4 GHz, and 25.4 GHz, which also feature considerable anisotropy of the g-tensors as well as two inequivalent lattice sites, indicating spins from Iron Group Ion (IGI) impurities. The comparison of undoped and Rare-Earth doped crystals reveal that the IGIs are introduced during co-doping of Eu{sup 3+} or Er{sup 3+} with concentration at much lower levels of order 100 ppb. The strong coupling regime between an ensemble of IGI spins and WGM photons have been demonstrated at 18.4 GHz and near zero field. This approach together with useful optical properties of these ions opens avenues for “spins-in-solids” Quantum Electrodynamics.

  10. PEG Functionalization of Whispering Gallery Mode Optical Microresonator Biosensors to Minimize Non-Specific Adsorption during Targeted, Label-Free Sensing

    Directory of Open Access Journals (Sweden)

    Fanyongjing Wang

    2015-07-01

    Full Text Available Whispering Gallery Mode (WGM optical microresonator biosensors are a powerful tool for targeted detection of analytes at extremely low concentrations. However, in complex environments, non-specific adsorption can significantly reduce their signal to noise ratio, limiting their accuracy. To overcome this, poly(ethylene glycol (PEG can be employed in conjunction with appropriate recognition elements to create a nonfouling surface capable of detecting targeted analytes. This paper investigates a general route for the addition of nonfouling elements to WGM optical biosensors to reduce non-specific adsorption, while also retaining high sensitivity. We use the avidin-biotin analyte-recognition element system, in conjunction with PEG nonfouling elements, as a proof-of-concept, and explore the extent of non-specific adsorption of lysozyme and fibrinogen at multiple concentrations, as well as the ability to detect avidin in a concentration-dependent fashion. Ellipsometry, contact angle measurement, fluorescence microscopy, and optical resonator characterization methods were used to study non-specific adsorption, the quality of the functionalized surface, and the biosensor’s performance. Using a recognition element ratio to nonfouling element ratio of 1:1, we showed that non-specific adsorption could be significantly reduced over the controls, and that high sensitivity could be maintained. Due to the frequent use of biotin-avidin-biotin sandwich complexes in functionalizing sensor surfaces with biotin-labeled recognition elements, this chemistry could provide a common basis for creating a non-fouling surface capable of targeted detection. This should improve the ability of WGM optical biosensors to operate in complex environments, extending their application towards real-world detection.

  11. User Manual for Whisper-1.1

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Forrest B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rising, Michael Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Alwin, Jennifer Louise [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-26

    Whisper is a statistical analysis package developed in 2014 to support nuclear criticality safety (NCS) validation [1-3]. It uses the sensitivity profile data for an application as computed by MCNP6 [4-6] along with covariance files [7,8] for the nuclear data to determine a baseline upper-subcritical-limit (USL) for the application. Whisper version 1.0 was first developed and used at LANL in 2014 [3]. During 2015- 2016, Whisper was updated to version 1.1 and is to be included with the upcoming release of MCNP6.2. This document describes the user input and options for running whisper-1.1, including 2 perl utility scripts that simplify ordinary NCS work, whisper_mcnp.pl and whisper_usl.pl. For many detailed references on the theory, applications, nuclear data & covariances, SQA, verification-validation, adjointbased methods for sensitivity-uncertainty analysis, and more – see the Whisper – NCS Validation section of the MCNP Reference Collection at mcnp.lanl.gov. There are currently over 50 Whisper reference documents available.

  12. User Manual for Whisper-1.1

    International Nuclear Information System (INIS)

    Brown, Forrest B.; Rising, Michael Evan; Alwin, Jennifer Louise

    2017-01-01

    Whisper is a statistical analysis package developed in 2014 to support nuclear criticality safety (NCS) validation [1-3]. It uses the sensitivity profile data for an application as computed by MCNP6 [4-6] along with covariance files [7,8] for the nuclear data to determine a baseline upper-subcritical-limit (USL) for the application. Whisper version 1.0 was first developed and used at LANL in 2014 [3]. During 2015- 2016, Whisper was updated to version 1.1 and is to be included with the upcoming release of MCNP6.2. This document describes the user input and options for running whisper-1.1, including 2 perl utility scripts that simplify ordinary NCS work, whisper_mcnp.pl and whisper_usl.pl. For many detailed references on the theory, applications, nuclear data & covariances, SQA, verification-validation, adjointbased methods for sensitivity-uncertainty analysis, and more - see the Whisper - NCS Validation section of the MCNP Reference Collection at mcnp.lanl.gov. There are currently over 50 Whisper reference documents available.

  13. Release Notes for Whisper-1.1

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Forrest B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rising, Michael Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Alwin, Jennifer Louise [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-04-27

    Whisper is a statistical analysis package developed in 2014 to support nuclear criticality safety (NCS) validation [1-3]. It uses the sensitivity profile data for an application as computed by MCNP6 [4-6] along with covariance files [7,8] for the nuclear data to determine a baseline upper-subcritical-limit (USL) for the application. Whisper version 1.0 was first developed and used at LANL in 2014 [3]. During 2015-2016, Whisper was updated to version 1.1 [9] and is to be included with the upcoming release of MCNP6.2. This document describes the Whisper-1.1 package that will be included with the MCNP6.2 release during 2017. Specific details are provided on the computer systems supported, the software quality assurance (SQA) procedures, installation, and testing. This document does not address other important topics, such as the importance of sensitivity-uncertainty (SU) methods to NCS validation, the theory underlying SU methodology, tutorials on the usage of MCNP-Whisper, practical approaches to using SU methodology to support and extend traditional validation, etc. There are over 50 documents included with Whisper-1.1 and available in the MCNP Reference Collection on the MCNP website (mcnp.lanl.gov) that address all of those topics and more. In this document, however, a complete bibliography of relevant MCNP-Whisper references is provided.

  14. Remote artificial eyes using micro-optical circuit for long-distance 3D imaging perception.

    Science.gov (United States)

    Thammawongsa, Nopparat; Yupapin, Preecha P

    2016-01-01

    A small-scale optical device incorporated with an optical nano-antenna is designed to operate as the remote artificial eye using a tiny conjugate mirror. A basic device known as a conjugate mirror can be formed using the artificial eye device, the partially reflected light intensities from input source are interfered and the 3D whispering gallery modes formed within the ring centers, which can be modulated and propagated to the object. The image pixel is obtained at the center ring and linked with the optic nerve in the remote area via the nano-antenna, which is useful for blind people.

  15. Cool Cosmology: ``WHISPER" better than ``BANG"

    Science.gov (United States)

    Carr, Paul

    2007-10-01

    Cosmologist Fred Hoyle coined ``big bang'' as a term of derision for Belgian priest George Lemaitre's prediction that the universe had originated from the expansion of a ``primeval atom'' in space-time. Hoyle referred to Lamaitre's hypothesis sarcastically as ``this big bang idea'' during a program broadcast on March 28, 1949 on the BBC. Hoyle's continuous creation or steady state theory can not explain the microwave background radiation or cosmic whisper discovered by Penzias and Wilson in 1964. The expansion and subsequent cooling of Lemaitre's hot ``primeval atom'' explains the whisper. ``Big bang'' makes no physical sense, as there was no matter (or space) to carry the sound that Hoyle's term implies. The ``big bang'' is a conjecture. New discoveries may be able to predict the observed ``whispering cosmos'' as well as dark matter and the nature of dark energy. The ``whispering universe'' is cooler cosmology than the big bang. Reference: Carr, Paul H. 2006. ``From the 'Music of the Spheres' to the 'Whispering Cosmos.' '' Chapter 3 of Beauty in Science and Spirit. Beech River Books. Center Ossipee, NH, http://www.MirrorOfNature.org.

  16. Surprising quantum bounces

    CERN Document Server

    Nesvizhevsky, Valery

    2015-01-01

    This unique book demonstrates the undivided unity and infinite diversity of quantum mechanics using a single phenomenon: quantum bounces of ultra-cold particles. Various examples of such "quantum bounces" are: gravitational quantum states of ultra-cold neutrons (the first observed quantum states of matter in a gravitational field), the neutron whispering gallery (an observed matter-wave analog of the whispering gallery effect well known in acoustics and for electromagnetic waves), and gravitational and whispering gallery states for anti-matter atoms that remain to be observed. These quantum states are an invaluable tool in the search for additional fundamental short-range forces, for exploring the gravitational interaction and quantum effects of gravity, for probing physics beyond the standard model, and for furthering studies into the foundations of quantum mechanics, quantum optics, and surface science.

  17. Image Gallery

    Science.gov (United States)

    ... R S T U V W X Y Z Image Gallery Share: The Image Gallery contains high-quality digital photographs available from ... Select a category below to view additional thumbnail images. Images are available for direct download in 2 ...

  18. Speaker-Sex Discrimination for Voiced and Whispered Vowels at Short Durations.

    Science.gov (United States)

    Smith, David R R

    2016-01-01

    Whispered vowels, produced with no vocal fold vibration, lack the periodic temporal fine structure which in voiced vowels underlies the perceptual attribute of pitch (a salient auditory cue to speaker sex). Voiced vowels possess no temporal fine structure at very short durations (below two glottal cycles). The prediction was that speaker-sex discrimination performance for whispered and voiced vowels would be similar for very short durations but, as stimulus duration increases, voiced vowel performance would improve relative to whispered vowel performance as pitch information becomes available. This pattern of results was shown for women's but not for men's voices. A whispered vowel needs to have a duration three times longer than a voiced vowel before listeners can reliably tell whether it's spoken by a man or woman (∼30 ms vs. ∼10 ms). Listeners were half as sensitive to information about speaker-sex when it is carried by whispered compared with voiced vowels.

  19. The Child Whisperer: Effective Parenting Strategies Adapted from "The Dog Whisperer"

    Science.gov (United States)

    McKinney, Cliff; Durr, Brandi

    2013-01-01

    Behavior modification with children has been popularized through television shows such as "Super Nanny" and "Nanny 911". The popularity of these shows may be related to the demand parents have for improving their children's behavior. Interestingly, an approach adopted by "The Dog Whisperer" may prove effective when used with children. The purpose…

  20. Lecture Notes on Criticality Safety Validation Using MCNP & Whisper

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Forrest B. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rising, Michael Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Alwin, Jennifer Louise [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-11

    Training classes for nuclear criticality safety, MCNP documentation. The need for, and problems surrounding, validation of computer codes and data area considered first. Then some background for MCNP & Whisper is given--best practices for Monte Carlo criticality calculations, neutron spectra, S(α,β) thermal neutron scattering data, nuclear data sensitivities, covariance data, and correlation coefficients. Whisper is computational software designed to assist the nuclear criticality safety analyst with validation studies with the Monte Carlo radiation transport package MCNP. Whisper's methodology (benchmark selection – Ck's, weights; extreme value theory – bias, bias uncertainty; MOS for nuclear data uncertainty – GLLS) and usage are discussed.

  1. TinyDebug

    DEFF Research Database (Denmark)

    Hansen, Morten Tranberg

    2011-01-01

    Debugging embedded wireless systems can be cumbersome due to low visibility. To ease the task of debugging this paper present TinyDebug which is a multi-purpose passive debugging framework for developing embedded wireless sys- tems. TinyDebug is designed to be used throughout the entire system...... logging to extraction and show how the frame- work improves upon existing message based and event log- ging debugging techniques while enabling distributed event processing. We also present a number of optional event anal- ysis tools demonstrating the generality of the TinyDebug debug messages....

  2. TinyOS Alliance Structure

    DEFF Research Database (Denmark)

    Bonnet, Philippe; Culler, David; Estrin, Deborah

    2006-01-01

    This memo describes the goals and organization structure of the TinyOS Alliance. It covers membership, the working group forums for contribution, intellectual property, source licensing, and the TinyOS Steering Committee (TSC)....

  3. Landslide Caused Damages in a Gallery

    Science.gov (United States)

    Poisel, R.; Mair am Tinkhof, K.; Preh, A.

    2016-06-01

    On October 5th, 2010, cracks were found in a gallery 1.8 m high and 1.4 m wide. The gallery is 100 years old, runs parallel to a valley flank and was excavated in a tectonically strongly stressed, weathered and slightly dipping sandwich of clayey shales, sandstones and marls. The cracks in the roof as well as in the invert ran parallel to the axis of the gallery. Monitoring showed that crack widths were increasing 1.5 mm per year, sidewall distances were increasing 3.5 mm per year, whereas the height of the gallery was decreasing 2.5 mm per year. After eliminating several possible causes of cracking, a landslide producing the damages had to be taken into consideration. Monitoring of the valley flank surface as well as inclinometer readings revealed that a landslide was occurring, loading the gallery lining. Most probably the landslide had been reactivated by excessive rainfall in 2009 as well as by works for the renewal of a weir in the valley bottom. As stabilization of the slope was not an option for several reasons, it was decided to replace the gallery by a new one deeper inside the slope, which will be ready for operation in 2017. Thus the old gallery has to be kept in operation till then and it was decided to reinforce the old gallery by a heavily reinforced shotcrete lining 10 cm thick. As slope displacements went on, cracks in the shotcrete lining developed with a completely different pattern: in the section where the gallery lies completely in the landslide shear zone no cracks formed until now due to heavy reinforcement, whereas in the transition sections stable ground-landslide and landslide-stable ground diagonal tension cracks in the roof due to shear by the landslide developed. Numerical models showed that cracking and spalling of the shotcrete lining would occur only after some centimetres of additional displacements of the slope, which hopefully will not occur before 2017.

  4. The Whisper Relaxation Sounder onboard Cluster: A Powerful Tool for Space Plasma Diagnosis around the Earth

    International Nuclear Information System (INIS)

    Trotignon, J.G.; Decreau, P.M.E.; Rauch, J.L.; LeGuirriec, E.; Canu, P.; Darrouzet, F.

    2001-01-01

    The WHISPER relaxation sounder that is onboard the four CLUSTER spacecraft has for main scientific objectives to monitor the natural waves in the 2 kHz - 80 kHz frequency range and, mostly, to determine the total plasma density from the solar wind down to the Earth's plasmasphere. To fulfil these objectives, the WHISPER uses the two long double sphere antennae of the Electric Field and Wave experiment as transmitting and receiving sensors. In its active working mode, the WHISPER works according to principles that have been worked out for topside sounding. A radio wave transmitter sends an almost monochromatic and short wave train. A few milliseconds after, a receiver listens to the surrounding plasma response. Strong and long lasting echoes are actually received whenever the transmitting frequencies coincide with characteristic plasma frequencies. Provided that these echoes, also called resonances, may be identified, the WHISPER relaxation sounder becomes a reliable and powerful tool for plasma diagnosis. When the transmitter is off, the WHISPER behaves like a passive receiver, allowing natural waves to be monitored. The paper aims mainly at the resonance identification process description and the WHISPER capabilities and performance highlighting. (author)

  5. Speaker-Sex Discrimination for Voiced and Whispered Vowels at Short Durations

    OpenAIRE

    Smith, David R. R.

    2016-01-01

    Whispered vowels, produced with no vocal fold vibration, lack the periodic temporal fine structure which in voiced vowels underlies the perceptual attribute of pitch (a salient auditory cue to speaker sex). Voiced vowels possess no temporal fine structure at very short durations (below two glottal cycles). The prediction was that speaker-sex discrimination performance for whispered and voiced vowels would be similar for very short durations but, as stimulus duration increases, voiced vowel pe...

  6. Chaos-assisted broadband momentum transformation in optical microresonators

    Science.gov (United States)

    Jiang, Xuefeng; Shao, Linbo; Zhang, Shu-Xin; Yi, Xu; Wiersig, Jan; Wang, Li; Gong, Qihuang; Lončar, Marko; Yang, Lan; Xiao, Yun-Feng

    2017-10-01

    The law of momentum conservation rules out many desired processes in optical microresonators. We report broadband momentum transformations of light in asymmetric whispering gallery microresonators. Assisted by chaotic motions, broadband light can travel between optical modes with different angular momenta within a few picoseconds. Efficient coupling from visible to near-infrared bands is demonstrated between a nanowaveguide and whispering gallery modes with quality factors exceeding 10 million. The broadband momentum transformation enhances the device conversion efficiency of the third-harmonic generation by greater than three orders of magnitude over the conventional evanescent-wave coupling. The observed broadband and fast momentum transformation could promote applications such as multicolor lasers, broadband memories, and multiwavelength optical networks.

  7. Advertising identities: virtual galleries as places of identity

    Directory of Open Access Journals (Sweden)

    Alexandra Zontea

    2010-10-01

    Full Text Available This paper is focused on the public presentation of self through virtual art galleries, singling out the field of photography. Photography has always been disputed as being part of the highbrow arts because of its popular character. Today, anyone who owes a photo camera can experience photography as art, without a rigorous training. Everybody is able to expose the photos freely to a large number of people, on the Internet. Consequently, the Internet opens up a virtual space, in which photo artists and amateurs can promote their works and exhibit them in a personal online gallery, which represents their place in the virtual vastness. Therefore, my research approaches the matter of the virtual gallery as an identitary place, being focused on finding out why artists choose to exhibit in virtual galleries. I asked myself what are the new functions of the virtual art galleries?Are they understood as online markers that distinguish the owners in these virtual environments? In other words, are these personal galleries a way of expressing online identities?

  8. The WHISPER Relaxation Sounder and the CLUSTER Active Archive

    Science.gov (United States)

    Trotignon, J. G.; Décréau, P. M. E.; Rauch, J. L.; Vallières, X.; Rochel, A.; Kougblénou, S.; Lointier, G.; Facskó, G.; Canu, P.; Darrouzet, F.; Masson, A.

    The Waves of HIgh frequency and Sounder for Probing of Electron density by Relaxation (WHISPER) instrument is part of the Wave Experiment Consortium (WEC) of the CLUSTER mission. With the help of the long double sphere antennae of the Electric Field and Wave (EFW) instrument and the Digital Wave Processor (DWP), it delivers active (sounding) and natural (transmitter off) electric field spectra, respectively from 4 to 82 kHz, and from 2 to 80 kHz. These frequency ranges have been chosen to include the electron plasma frequency, which is closely related to the total electron density, in most of the regions encountered by the CLUSTER spacecraft. Presented here is an overview of the WHISPER data products available in the CLUSTER Active Archive (CAA). The instrument and its performance are first recalled. The way the WHISPER products are obtained is then described, with particular attention being paid to the density determination. Both sounding and natural measurements are commonly used in this process, which depends on the ambient plasma regime. This is illustrated using drawings similar to the Bryant plots commonly used in the CLUSTER master science plan. These give a clear overview of typical density values and the parts of the orbits where they are obtained. More information on the applied software or on the quality/reliability of the density determination can also be highlighted.

  9. Plutonium Critical Mass Curve Comparison to Mass at Upper Subcritical Limit (USL) Using Whisper

    International Nuclear Information System (INIS)

    Alwin, Jennifer Louise; Zhang, Ning

    2016-01-01

    Whisper is computational software designed to assist the nuclear criticality safety analyst with validation studies with the MCNP ® Monte Carlo radiation transport package. Standard approaches to validation rely on the selection of benchmarks based upon expert judgment. Whisper uses sensitivity/uncertainty (S/U) methods to select relevant benchmarks to a particular application or set of applications being analyzed. Using these benchmarks, Whisper computes a calculational margin. Whisper attempts to quantify the margin of subcriticality (MOS) from errors in software and uncertainties in nuclear data. The combination of the Whisper-derived calculational margin and MOS comprise the baseline upper subcritical limit (USL), to which an additional margin may be applied by the nuclear criticality safety analyst as appropriate to ensure subcriticality. A series of critical mass curves for plutonium, similar to those found in Figure 31 of LA-10860-MS, have been generated using MCNP6.1.1 and the iterative parameter study software, WORM S olver. The baseline USL for each of the data points of the curves was then computed using Whisper 1.1. The USL was then used to determine the equivalent mass for plutonium metal-water system. ANSI/ANS-8.1 states that it is acceptable to use handbook data, such as the data directly from the LA-10860-MS, as it is already considered validated (Section 4.3 4) ''Use of subcritical limit data provided in ANSI/ANS standards or accepted reference publications does not require further validation.''). This paper attempts to take a novel approach to visualize traditional critical mass curves and allows comparison with the amount of mass for which the k eff is equal to the USL (calculational margin + margin of subcriticality). However, the intent is to plot the critical mass data along with USL, not to suggest that already accepted handbook data should have new and more rigorous requirements for validation.

  10. Nonlinear Optical Terahertz Technology

    Data.gov (United States)

    National Aeronautics and Space Administration — We develop a new approach to generation of THz radiation. Our method relies on mixing two optical frequency beams in a nonlinear crystalline Whispering Gallery Mode...

  11. Theoretical examination of the slot channel waveguide configured in a cylindrically symmetric dielectric ring profile

    Science.gov (United States)

    Gauthier, Robert C.; Alzahrani, Mohammed A.; Jafari, Seyed Hamed

    2014-10-01

    It has recently been experimentally demonstrated that slot channel waveguides, configured in cylindrical space, can support high azimuthal order modes similar to whispering-gallery modes. This paper presents a mode solver based on Maxwell's vector wave equation for the electric field cast into an eigenvalue problem using a Fourier-Bessel basis function space. The modal frequencies and field profiles of the high azimuthal order slot-channel-whispering-gallery (SCWG) modes are computed for a set of nanometer spaced silicon rings supported by oxide. The computations show, that in addition to the traditionally observed, lowest order mode, the structure may support higher order SCWG modes. We complete the analysis by computing structures response as an ambient medium index of refraction sensor which achieves over 400 nm per RIU sensitivity.

  12. Early results from the Whisper instrument on Cluster: An overview

    DEFF Research Database (Denmark)

    Decreau, P.M.E.; Fergeau, P.; Krasnoselskikh, V.

    2001-01-01

    The Whisper instrument yields two data sets: (i) the electron density determined via the relaxation sounder, and (ii) the spectrum of natural plasma emissions in the frequency band 2-80 kHz. Both data sets allow for the three-dimensional exploration of the magnetosphere by the Cluster mission...... the drift velocity of density structures. Wave observations are also of crucial interest for studying small-scale structures, as demonstrated in an example in the fore-shock region. Early results from the Whisper instrument are very encouraging, and demonstrate that the four-point Cluster measurements...... largely overcomes the limited telemetry allocation. The natural emissions are usually related to the plasma frequency, as identified by the sounder, and the combination of an active sounding operation and a passive survey operation provides a time resolution for the total density determination of 2.2 s...

  13. Wireless Hybrid Identification and Sensing Platform for Equipment Recovery (WHISPER), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Systems & Technologies proposed WHISPER (Wireless Hybrid Identification and Sensing Platform for Equipment Recovery) solution to NASA's need for...

  14. Wireless Hybrid Identification and Sensing Platform for Equipment Recovery (WHISPER), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Systems & Technologies proposed WHISPER (Wireless Hybrid Identification and Sensing Platform for Equipment Recovery) solution to NASA's need for...

  15. NAIP Status Maps Gallery

    Data.gov (United States)

    Farm Service Agency, Department of Agriculture — NAIP Status Maps Gallery. These maps illustrate what aerial imagery collection is planned, whats been collected, when it is available and how it is available. These...

  16. Opportunities for Innovation Adoption in Art Galleries

    Directory of Open Access Journals (Sweden)

    Ieva VITKAUSKAITĖ

    2016-12-01

    Full Text Available This article introduces the opportunities for innovation adoption in art galleries. It provides systematised information on innovation processes and innovations used in business models of art galleries. The empirical research conducted has revealed the attitude of art galleries towards innovations, as well as the benefits and opportunities to realise them. The first part of the article distinguishes the stages of innovation process and management. The following part describes the factors that influence the management of innovation process. The final part of the article analyses the application of innovations for the improvement of a business model, with Business Model Canvas by Alexander Osterwalder and Yves Pigneur selected as the starting point for analysis and, finally, the outcomes of empirical research are provided.

  17. Genesis of a Joint Gallery of Sport Art.

    Science.gov (United States)

    Kozar, Andrew J.

    1989-01-01

    The University of Pennsylvania's dual sport art gallery showcases the work of R. Taft McKenzie and Joe Brown, two of the premier sport artists of our time. This article briefly outlines the artists' careers and describes the planning which led to establishment of the gallery. (IAH)

  18. Alannah Coleman: 1970—A Year at Bonython’s Sydney Gallery

    Directory of Open Access Journals (Sweden)

    Simon Pierse

    2018-03-01

    Full Text Available When art dealer and entrepreneur Kym Bonython’s new gallery opened in Sydney in 1967, it was believed to be the largest commercial gallery in the southern hemisphere. In early 1970, Bonython brought Melbourne-born art dealer Alannah Coleman over from London to take on the management of his gallery. Sadly, her appointment was not a success and lasted less than a year. Coleman re-organised the records and accounts along European lines and tried to put the gallery on a firm financial footing, but she met with opposition from staff, artists and Bonython himself. Bonython wanted the gallery as a showcase for new talent and was always on the lookout to spot ‘the next goer’. The opening parties at Bonython’s deplored by Coleman as ‘open slather’ evenings proved to be significant social events and the focus for cultural exchange, whilst in his solo shows, Brett Whiteley made innovative use of the gallery as a ‘theatre’, combining painting and sculpture with light and sound to transform the exhibition into a completely new synesthetic experience. In 1971, with funding from John Kaldor’s Public Art Project scheme, Swiss curator and gallerist Harald Szeemann used the Bonython Gallery to stage a groundbreaking show of conceptual art that went on to show at the National Gallery of Victoria, Melbourne. Without a regular external source of sponsorship or support, however, Coleman’s fears for the financial viability of the gallery were eventually proved right when, after several further years of losses, it finally closed in 1976.

  19. Chaos-assisted broadband momentum transformation in optical microresonators.

    Science.gov (United States)

    Jiang, Xuefeng; Shao, Linbo; Zhang, Shu-Xin; Yi, Xu; Wiersig, Jan; Wang, Li; Gong, Qihuang; Lončar, Marko; Yang, Lan; Xiao, Yun-Feng

    2017-10-20

    The law of momentum conservation rules out many desired processes in optical microresonators. We report broadband momentum transformations of light in asymmetric whispering gallery microresonators. Assisted by chaotic motions, broadband light can travel between optical modes with different angular momenta within a few picoseconds. Efficient coupling from visible to near-infrared bands is demonstrated between a nanowaveguide and whispering gallery modes with quality factors exceeding 10 million. The broadband momentum transformation enhances the device conversion efficiency of the third-harmonic generation by greater than three orders of magnitude over the conventional evanescent-wave coupling. The observed broadband and fast momentum transformation could promote applications such as multicolor lasers, broadband memories, and multiwavelength optical networks. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  20. Dimensioning of lining galleries in deep clays

    International Nuclear Information System (INIS)

    Bernaud, D.; Rousset, G.

    1991-01-01

    The aim of the work presented in this report is to study the mechanical behaviour of lining galleries in deep clays. This text constitutes a part of the researches on the feasibility of a geological disposal of radioactive waste, which the scope is to assure the gallery long term stabilization and also to optimize its dimensioning. In particular, we are interested here in the study of a closure controlled lining, that constitutes a direct application of the convergence-confinement method, especially well fitted to deep clays. The presentation and interpretation of the convergence controlled lining test, which was performed in the experimental gallery of Mol in Belgium, is given in this report. The instrumentation was conceived in order to find out the stress field exerced by the rockmass on the lining, the internal stress field inside the lining and the gallery closure. The analysis of all measurements results, obtained between november 1987 and December 1989, shows that they are all in good agreement and that the lining design was well chosen. Two years after the gallery construction, the average closure is of the order of 2% and the average confinement pressure is about 1.6 MPa (the third of the lithostatic pressure). The time dependent effects of the rockmass are very well modelled by the non linear elasto-viscoplastic law developed at L.M.S. with the laboratory tests. The elastic-plastic model of the lining are shown to be well fitted to simulate the sliding of the ribs. Finally, the numerical results have shown a very good agreement with the measurements results

  1. Coral Reefs: A Gallery Program, Grades 7-12.

    Science.gov (United States)

    National Aquarium in Baltimore, MD. Dept. of Education.

    Gallery classes at the National Aquarium in Baltimore give the opportunity to study specific aquarium exhibits which demonstrate entire natural habitats. The coral reef gallery class features the gigantic western Atlantic coral reef (325,000 gallons) with over 1,000 fish. The exhibit simulates a typical Caribbean coral reef and nearby sandy…

  2. Tiny plastic lung mimics human pulmonary function

    Science.gov (United States)

    Careers Inclusion & Diversity Work-Life Balance Career Resources Apply for a Job Postdocs Students Goals Recycling Green Purchasing Pollution Prevention Reusing Water Resources Environmental Management Releases - 2016 » April » Tiny plastic lung mimics human pulmonary function Tiny plastic lung mimics

  3. Whispering-gallery mode microcavity quantum-dot lasers

    International Nuclear Information System (INIS)

    Kryzhanovskaya, N V; Maximov, M V; Zhukov, A E

    2014-01-01

    This review examines axisymmetric-cavity quantum-dot microlasers whose emission spectrum is determined by whisperinggallery modes. We describe the possible designs, fabrication processes and basic characteristics of the microlasers and demonstrate the possibility of lasing at temperatures above 100 °C. The feasibility of creating multichannel optical sources based on a combination of a broadband quantum-dot laser and silicon microring modulators is discussed. (review)

  4. Low-threshold conical microcavity dye lasers

    DEFF Research Database (Denmark)

    Grossmann, Tobias; Schleede, Simone; Hauser, Mario

    2010-01-01

    element simulations confirm that lasing occurs in whispering gallery modes which corresponds well to the measured multimode laser-emission. The effect of dye concentration on lasing threshold and lasing wavelength is investigated and can be explained using a standard dye laser model....

  5. The effects of whispering-to-oneself and silent reading on text memory and comprehension in children

    OpenAIRE

    Matsumi, Norio; Furumoto, Yumi; Mitsuke, Ai

    2005-01-01

    An experiment was carried out to investigate the effects of whispering-to-oneself reading on text memory and comprehension in children (6th grade). A2×2 factorial design was used in the experiment: the first independent variable was whispering-to-oneself or silent reading, the second was large- or small-working memory span which were measured by the reading span test (RST). Four aspects of the text memory and comprehension were observed as dependent variables: text memory both on the literal ...

  6. Promenade Among Words and Things: The Gallery as Catalogue, the Catalogue as Gallery

    Directory of Open Access Journals (Sweden)

    Mari Lending

    2015-12-01

    Full Text Available In the mid nineteenth century new casting techniques allowed for the production of huge architectural fragments. Well-selected collections could ideally display perfect series in galleries in which the visitor could wander among monuments and experience architecture history on full scale. The disembodied material of plaster was considered capable of embodying a number of modern historical taxonomies and aesthetical programs, most importantly chronology, comparison, style, and evolution. Veritable showcases of historicism, the casts could illustrate in spatial arrangements new conceptions on the history, contemporaneity and future of architecture. Plaster cast became a main medium in which to publish antiquities as novelties for grand audiences, taking the printed and published beyond the two-dimensional space of words and images. However, due to the increasing market of casts and their sheere size and weight, the reproductions as mounted in the galleries often behaved as unruly as architecture does outside curatorial control. In the end only the catalogues, the paper versions of these imaginary museums were capable to create the orders that their plaster referents constantly aspired to destroy. An important chapter in the history of the architecture museum these plaster monuments belong to a part of architectural print culture in which catalogues were curated and galleries edited. Metaphors drawn from the realm of writing saturated the discourse on the display of casts. Images and texts fluctuated and the image-objects were compared to books, paper, pages, documents and libraries but above all to illustrations inviting promenades in time and space.

  7. A microring multimode laser using hollow polymer optical fibre

    Indian Academy of Sciences (India)

    Dye-doped optical fibre; fibre laser; microcavity; whispering gallery mode. ... Cylindrical microcavities with diameters 155, 340 and 615 m were fabricated from a dye-doped hollow polymer optical fibre preform. ... International School of Photonics, Cochin University of Science and Technology, Kochi 682 022, India ...

  8. Quantum-dot-based integrated non-linear sources

    DEFF Research Database (Denmark)

    Bernard, Alice; Mariani, Silvia; Andronico, Alessio

    2015-01-01

    The authors report on the design and the preliminary characterisation of two active non-linear sources in the terahertz and near-infrared range. The former is associated to difference-frequency generation between whispering gallery modes of an AlGaAs microring resonator, whereas the latter...

  9. Upconversion channels in Er3+ ZBLALiP fluoride glass microspheres

    NARCIS (Netherlands)

    O'Shea, D. G.; Ward, J. M.; Shortt, B. J.; Mortier, M.; Feron, P.; Chormaic, S. Nic

    We present results on the realization of a multicolour microspherical glass light source fabricated from the erbium doped fluoride glass ZBLALiP. Whispering gallery mode lasing and upconversion processes give rise to laser and fluorescent emissions at multiple wavelengths from the ultraviolet to the

  10. Science Outreach through Art: A Journal Article Cover Gallery

    Science.gov (United States)

    McCullough, Ian

    2015-01-01

    Research faculty journal covers were used to create a gallery in the Science & Technology branch library at the University of Akron. The selection, presentation, and promotion process is shared along with copyright considerations and a review of galleries used for library outreach. The event and display was a great success attracting faculty…

  11. Application of gallery-drilling exploration in underground uranium mining and its evaluation

    International Nuclear Information System (INIS)

    Chen Ruichun; Zou Guohe

    1990-01-01

    Combination method of gallery and drilling is an effective one in production exploration. On the basis of the 20 years practice of a uranium mine using the gallery-drilling combination method in production exploration, the advantages, applications, engineering networks, principles of application of the gallery-drilling combination method and the results of its application are described

  12. The Tiny Terminators

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 5. The Tiny Terminators - Mosquitoes and Diseases. P K Sumodan. General Article Volume 6 Issue 5 May 2001 pp 48-55. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/006/05/0048-0055 ...

  13. Multimode laser emission from dye-doped hollow polymer optical fibre

    Indian Academy of Sciences (India)

    2014-02-09

    Feb 9, 2014 ... Fibre lasers; optical microcavities; whispering gallery modes. ... A blueshift in the mode structure was observed with decrease in fibre diameter leading to wide range tunability of the laser emission. ... International School of Photonics, Cochin University of Science & Technology, Cochin 682 022, India ...

  14. Advanced Quasioptical Launcher System. Final Report

    International Nuclear Information System (INIS)

    Neilson, Jeffrey

    2010-01-01

    This program developed an analytical design tool for designing antenna and mirror systems to convert whispering gallery RF modes to Gaussian or HE11 modes. Whispering gallery modes are generated by gyrotrons used for electron cyclotron heating of fusion plasmas in tokamaks. These modes cannot be easily transmitted and must be converted to free space or waveguide modes compatible with transmission line systems.This program improved the capability of SURF3D/LOT, which was initially developed in a previous SBIR program. This suite of codes revolutionized quasi-optical launcher design, and this code, or equivalent codes, are now used worldwide. This program added functionality to SURF3D/LOT to allow creating of more compact launcher and mirror systems and provide direct coupling to corrugated waveguide within the vacuum envelope of the gyrotron. Analysis was also extended to include full-wave analysis of mirror transmission line systems. The code includes a graphical user interface and is available for advanced design of launcher systems.

  15. National Gallery in Prague

    Czech Academy of Sciences Publication Activity Database

    Mikeš, Stanislav; Haindl, Michal; Holub, Radek

    2011-01-01

    Roč. 2011, č. 86 (2011), s. 23-24 ISSN 0926-4981 R&D Projects: GA MŠk(CZ) LG11009 Institutional research plan: CEZ:AV0Z10750506 Keywords : virtrual reality * information system Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2011/RO/haindl-national gallery in prague.pdf

  16. Structural analysis of an off-grid tiny house

    Science.gov (United States)

    Calluari, Karina Arias; Alonso-Marroquín, Fernando

    2017-06-01

    The off-grid technologies and tiny house movement have experimented an unprecedented growth in recent years. Putting both sides together, we are trying to achieve an economic and environmental friendly solution to the higher cost of residential properties. This solution is the construction of off-grid tiny houses. This article presents a design for a small modular off-grid house made by pine timber. A numerical analysis of the proposed tiny house was performed to ensure its structural stability. The results were compared with the suggested serviceability limit state criteria, which are contended in the Australia Guidelines Standards making this design reliable for construction.

  17. Microring Diode Laser for THz Generation

    DEFF Research Database (Denmark)

    Mariani, S.; Andronico, A.; Favero, I.

    2013-01-01

    We report on the modeling and optical characterization of AlGaAs/InAs quantum-dot microring diode lasers designed for terahertz (THz) difference frequency generation (DFG) between two whispering gallery modes (WGMs) around 1.3 $\\mu$m. In order to investigate the spectral features of this active...

  18. Effect of Galleries on Thermal Conditions of Urban Open Areas

    Directory of Open Access Journals (Sweden)

    Shahab Kariminia

    2016-06-01

    Full Text Available Computer simulations were performed by ENVI-met model along with physical measurements in two urban squares under hot summer conditions in Isfahan, central Iran. Each scenario concentrated on adding or extending galleries in each square. The results confirmed the role of galleries on thermal conditions; however, it was found that the effectiveness of this strategy depends on the square geometry. It presented higher efficiency for the small square with higher H/W ratio. This solution is advisable for smaller squares and when the peripheral parts are frequently used compared to the middle areas. Galleries are most efficient when allowing enough natural ventilation.

  19. A gallery approach for off-angle iris recognition

    Science.gov (United States)

    Karakaya, Mahmut; Yoldash, Rashiduddin; Boehnen, Christopher

    2015-05-01

    It has been proven that hamming distance score between frontal and off-angle iris images of same eye differs in iris recognition system. The distinction of hamming distance score is caused by many factors such as image acquisition angle, occlusion, pupil dilation, and limbus effect. In this paper, we first study the effect of the angle variations between iris plane and the image acquisition systems. We present how hamming distance changes for different off-angle iris images even if they are coming from the same iris. We observe that increment in acquisition angle of compared iris images causes the increment in hamming distance. Second, we propose a new technique in off-angle iris recognition system that includes creating a gallery of different off-angle iris images (such as, 0, 10, 20, 30, 40, and 50 degrees) and comparing each probe image with these gallery images. We will show the accuracy of the gallery approach for off-angle iris recognition.

  20. TinyOS-based quality of service management in wireless sensor networks

    Science.gov (United States)

    Peterson, N.; Anusuya-Rangappa, L.; Shirazi, B.A.; Huang, R.; Song, W.-Z.; Miceli, M.; McBride, D.; Hurson, A.; LaHusen, R.

    2009-01-01

    Previously the cost and extremely limited capabilities of sensors prohibited Quality of Service (QoS) implementations in wireless sensor networks. With advances in technology, sensors are becoming significantly less expensive and the increases in computational and storage capabilities are opening the door for new, sophisticated algorithms to be implemented. Newer sensor network applications require higher data rates with more stringent priority requirements. We introduce a dynamic scheduling algorithm to improve bandwidth for high priority data in sensor networks, called Tiny-DWFQ. Our Tiny-Dynamic Weighted Fair Queuing scheduling algorithm allows for dynamic QoS for prioritized communications by continually adjusting the treatment of communication packages according to their priorities and the current level of network congestion. For performance evaluation, we tested Tiny-DWFQ, Tiny-WFQ (traditional WFQ algorithm implemented in TinyOS), and FIFO queues on an Imote2-based wireless sensor network and report their throughput and packet loss. Our results show that Tiny-DWFQ performs better in all test cases. ?? 2009 IEEE.

  1. Preliminary investigations on TINI based distributed instrumentation systems

    International Nuclear Information System (INIS)

    Bezboruah, T.; Kalita, M.

    2006-04-01

    A prototype web enabled distributed instrumentation system is being proposed in the Department of Electronics Science, Gauhati University, Assam, India. The distributed instrumentation system contains sensors, legacy hardware, TCP/IP protocol converter, TCP/IP network Ethernet, Database Server, Web/Application Server and Client PCs. As part of the proposed work, Tiny Internet Interface (TINI, TBM390: Dallas Semiconductor) has been deployed as TCP/IP stack, and java programming language as software tools. A feature supported by Java, that is particularly relevant to the distributed system is its applet. An applet is a java class that can be downloaded from the web server and can be run in a context application such as web browser or an applet viewer. TINI has been installed as TCP/IP stack, as it is the best suited embedded system with java programming language and it has been uniquely designed for communicating over One Wire Devices (OWD) over network. Here we will discuss the hardware and software aspects of TINI with OWD for the present system. (author)

  2. Presence and its absences. The 17th century gallery picture

    DEFF Research Database (Denmark)

    Bogh, Mikkel

    A discussion of how pictures made specifically for the gallery viewer in the 17th century produce certain kinds of presence in order to catch attention......A discussion of how pictures made specifically for the gallery viewer in the 17th century produce certain kinds of presence in order to catch attention...

  3. The Habitable Zone Gallery and its Applications

    Science.gov (United States)

    Gelino, Dawn M.; Kane, S. R.

    2012-05-01

    The Habitable Zone Gallery (www.hzgallery.org) is a service to the exoplanet community which provides Habitable Zone (HZ) information for each of the exoplanetary systems with known planetary orbital parameters. The service includes a sortable table, a plot with the period and eccentricity of each of the planets with respect to their time spent in the HZ, a gallery of known systems which plot the orbits and the location of the HZ with respect to those orbits, and orbital movies. Here we discuss various educational and scientific applications of the site such as target selection, exploring planets with eccentric orbits, and investigating habitability.

  4. Intense echolocation calls from two ;whispering' bats, Artibeus jamaicensis and Macrophyllum macrophyllum (Phyllostomidae)

    DEFF Research Database (Denmark)

    Brinkløv, Signe; Kalko, Elisabeth K V; Surlykke, Annemarie

    2009-01-01

    Bats use echolocation to exploit a variety of habitats and food types. Much research has documented how frequency-time features of echolocation calls are adapted to acoustic constraints imposed by habitat and prey but emitted sound intensities have received little attention. Bats from the family...... of Phyllostomidae have been categorised as low intensity (whispering) gleaners, assumed to emit echolocation calls with low source levels (approximately 70 dB SPL measured 10 cm from the bat's mouth). We used a multi-microphone array to determine intensities emitted from two phyllostomid bats from Panamá...... room. Both species emitted surprisingly intense signals with maximum source levels of 105 dB SPL r.m.s. for M. macrophyllum and 110 dB SPL r.m.s. for A. jamaicensis, hence much louder than a ;whisper'. M. macrophyllum was consistently loud (mean source level 101 dB SPL) whereas A. jamaicensis showed...

  5. Wind galleries: an instrument for environmental impact assessment

    International Nuclear Information System (INIS)

    Zunino, C.

    1998-01-01

    In the last decades wind galleries for non-aeronautic utilisation have proved to be a useful investigation tool in various fields, such as studies on environmental impact and risk assessment, associated with permanent or incidental release of harmful substances. In this framework the feasibility of a new installation has been evaluated in Italy, having as main target the reproduction of thermal stratification phenomena. The great deal of 'hazardous' industries, often in areas having a complex orography, as well as the high pollution levels in Italian cities, lead to the conclusion that a thermally stratified wind gallery might be an economically viable investment [it

  6. High tunability and superluminescence in InAs mid-infrared light emitting diodes

    International Nuclear Information System (INIS)

    Sherstnev, V.V.; Krier, A.; Hill, G.

    2002-01-01

    We report on the observation of super luminescence and high spectral current tunability (181 nm) of InAs light emitting diodes operating at 3.0 μm. The source is based on an optical whispering gallery mode which is generated near the edges of the mesa and which is responsible for the superluminescence. (author)

  7. Influence of musical training on understanding voiced and whispered speech in noise.

    Science.gov (United States)

    Ruggles, Dorea R; Freyman, Richard L; Oxenham, Andrew J

    2014-01-01

    This study tested the hypothesis that the previously reported advantage of musicians over non-musicians in understanding speech in noise arises from more efficient or robust coding of periodic voiced speech, particularly in fluctuating backgrounds. Speech intelligibility was measured in listeners with extensive musical training, and in those with very little musical training or experience, using normal (voiced) or whispered (unvoiced) grammatically correct nonsense sentences in noise that was spectrally shaped to match the long-term spectrum of the speech, and was either continuous or gated with a 16-Hz square wave. Performance was also measured in clinical speech-in-noise tests and in pitch discrimination. Musicians exhibited enhanced pitch discrimination, as expected. However, no systematic or statistically significant advantage for musicians over non-musicians was found in understanding either voiced or whispered sentences in either continuous or gated noise. Musicians also showed no statistically significant advantage in the clinical speech-in-noise tests. Overall, the results provide no evidence for a significant difference between young adult musicians and non-musicians in their ability to understand speech in noise.

  8. Lead-silicate glass optical microbubble resonator

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Pengfei, E-mail: pengfei.wang@dit.ie [Photonics Research Centre, Dublin Institute of Technology, Kevin Street, Dublin 8 (Ireland); Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ (United Kingdom); Ward, Jonathan; Yang, Yong; Chormaic, Síle Nic [Light-Matter Interactions Unit, OIST Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495 (Japan); Feng, Xian; Brambilla, Gilberto [Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ (United Kingdom); Farrell, Gerald [Photonics Research Centre, Dublin Institute of Technology, Kevin Street, Dublin 8 (Ireland)

    2015-02-09

    Microbubble whispering gallery resonators have the potential to become key components in a variety of active and passive photonic circuit devices by offering a range of significant functionalities. Here, we report on the fabrication, optical characterization, and theoretical analysis of lead-silicate glass and optical microbubble resonators. Evanescent field coupling to the microbubbles was achieved using a 1 μm diameter, silica microfiber at a wavelength of circa 775 nm. High Q-factor modes were efficiently excited in both single-stem and two-stem, lead-silicate glass, and microbubble resonators, with bubble diameters of 38 μm (single-stem) and 48 μm (two-stem). Whispering gallery mode resonances with Q-factors as high as 2.3 × 10{sup 5} (single-stem) and 7 × 10{sup 6} (two-stem) were observed. By exploiting the high-nonlinearity of the lead-silicate glass, this work will act as a catalyst for studying a range of nonlinear optical effects in microbubbles, such as Raman scattering and four-wave mixing, at low optical powers.

  9. Stress transmission through Ti-Ni alloy, titanium and stainless steel in impact compression test.

    Science.gov (United States)

    Yoneyama, T; Doi, H; Kobayashi, E; Hamanaka, H; Tanabe, Y; Bonfield, W

    2000-06-01

    Impact stress transmission of Ti-Ni alloy was evaluated for biomedical stress shielding. Transformation temperatures of the alloy were investigated by means of DSC. An impact compression test was carried out with use of split-Hopkinson pressure-bar technique with cylindrical specimens of Ti-Ni alloy, titanium and stainless steel. As a result, the transmitted pulse through Ti-Ni alloy was considerably depressed as compared with those through titanium and stainless steel. The initial stress reduction was large through Ti-Ni alloy and titanium, but the stress reduction through Ti-Ni alloy was more continuous than titanium. The maximum value in the stress difference between incident and transmitted pulses through Ti-Ni alloy or titanium was higher than that through stainless steel, while the stress reduction in the maximum stress through Ti-Ni alloy was statistically larger than that through titanium or stainless steel. Ti-Ni alloy transmitted less impact stress than titanium or stainless steel, which suggested that the loading stress to adjacent tissues could be decreased with use of Ti-Ni alloy as a component material in an implant system. Copyright 2000 Kluwer Academic Publishers

  10. Theorizing How Art Gallery Interventions Impact People With Dementia and Their Caregivers.

    Science.gov (United States)

    Camic, Paul M; Baker, Erin L; Tischler, Victoria

    2016-12-01

    Dementia refers to a variety of diseases that are characterized by cognitive difficulties and an overall decline in daily living skills. Psychologically informed arts and health programs may be particularly beneficial ways of improving the lives of people with dementia and their caregivers. This study sought to better understand how programs at contemporary and traditional art galleries might play a role in the lives of people with dementia. Participants included 12 people with mild-to-moderate dementia, their 12 caregivers and 4 gallery facilitators. Those with dementia and their caregivers were engaged in art viewing followed by art making over an 8-week period. Data, collected through postintervention interviews with participants, field notes and extensive written communication between the facilitators and research team, were analyzed using grounded theory methodology to theorize how gallery-based interventions affect people with dementia and those who care for them. The emerging theory has four primary components: the art gallery is seen as being a physically valued place that provides intellectual stimulation and offers opportunities for social inclusion that can change how dementia is perceived. These components coalesced to create positive emotional and relational effects for those with dementia and caregivers. The resulting theory has potential implications for the use of gallery-based programs in dementia care within public health, healthcare, and museum/art gallery policy and practice. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Tiny Devices Project Sharp, Colorful Images

    Science.gov (United States)

    2009-01-01

    Displaytech Inc., based in Longmont, Colorado and recently acquired by Micron Technology Inc. of Boise, Idaho, first received a Small Business Innovation Research contract in 1993 from Johnson Space Center to develop tiny, electronic, color displays, called microdisplays. Displaytech has since sold over 20 million microdisplays and was ranked one of the fastest growing technology companies by Deloitte and Touche in 2005. Customers currently incorporate the microdisplays in tiny pico-projectors, which weigh only a few ounces and attach to media players, cell phones, and other devices. The projectors can convert a digital image from the typical postage stamp size into a bright, clear, four-foot projection. The company believes sales of this type of pico-projector may exceed $1.1 billion within 5 years.

  12. Durability of visitable concrete sewer gallery under the effect of domestic wastewater

    Science.gov (United States)

    Salhi, Aimed; Kriker, Abdelouahed; Tioua, Tahar; Abimiloud, Youcef; Barluenga, Gonzalo

    2016-07-01

    The durability of concrete structures for the disposal of wastewater depends on their behavior when faced to different aggressions such as mechanics, chemical and biological, causing a deterioration often cementing matrix. The deterioration of recent evacuations wastewater infrastructure, made of reinforced concrete less than 15 years ago, has become an important concern. The aim of this study was to investigate the degradation and the factors responsible for the deterioration of the concrete visitable gallery of sewage from the town of Touggourt (south-east of Algeria). Thus, samples from different parts of the gallery were extracted and unaltered samples were selected as a reference. A degraded sample exposed to H2S gas and another sample of the gallery submerged into wastewater were analyzed to characterize the internal and external damage to the gallery as well as the chemical and mineralogical changes. These tests were complemented by a physical and mechanical characterization of the samples. The experimental results showed the strong anisotropy of both internal and external damage.

  13. Soliton Coupling Driven by Phase Fluctuations in Auto-Parametric Resonance

    CERN Document Server

    Binder, B

    2002-01-01

    In this paper the interaction of sine-Gordon solitons and mediating linear waves is modelled by a special case of auto-parametric resonance, the Rayleigh-type self-excited non-linear autonomous system driven by a statistical phase gradient related to the soliton energy. Spherical symmetry can stimulate "whispering gallery modes" (WGM) with integral coupling number M=137.

  14. EIT in resonator chains: similarities and differences with atomic media

    Science.gov (United States)

    Matsko, A. B.; Maleki, L.; Savchenkov, A. A.; Ilchenko, V. S.

    2004-01-01

    We theoretically study a parallel configuration of two interacting whispering gallery mode optical resonators and show a narrow-band modal structure as a basis for a widely tunable delay line. For the optimum coupling configuration the system can possess an unusually narrow spectral feature with a much narrower bandwidth than the loaded bandwidth of each individual resonator.

  15. The martensitic transformation in Ti-rich TiNi shape memory alloys

    International Nuclear Information System (INIS)

    Lin, H.C.; Wu, S.K.; Lin, J.C.

    1994-01-01

    The martensitic (Ms) transformation temperatures and their ΔH values of Ti 51 Ni 49 and Ti 50.5 Ni 49.5 alloys are higher than those of equiatomic or Ni-rich TiNi alloys. The Ti-rich TiNi alloys exhibit good shape recovery in spite of a great deal of second phase Ti 2 Ni or Ti 4 Ni 2 O existing around B2 grain boundaries. The nearly identical transformation temperatures indicate that the absorbed oxygen in Ti-rich TiNi alloys may react with Ti 2 Ni particles, instead of the TiNi matrix, to form Ti 4 Ni 2 O. Martensite stabilization can be induced by cold rolling at room temperature. Thermal cycling can depress the transformation temperatures significantly, especially in the initial 20 cycles. The R-phase transformation can be promoted by both cold rolling and thermal cycling in Ti-rich TiNi alloys due to introduced dislocations depressing the Ms temperature. The strengthening effects of cold rolling and thermal cycling on the Ms temperature of Ti-rich TiNi alloys are found to follow the expression Ms = To - KΔσ y . The K values are affected by different strengthening processes and related to the as-annealed transformation temperatures. The higher the as-annealed Ms (or As), the larger the K value. (orig.)

  16. The art of compromise: the founding of the National Gallery of British Art, 1890-1892

    Directory of Open Access Journals (Sweden)

    Amy Woodson-Boulton

    2015-03-01

    Full Text Available This article argues that the press played a key role in defining the Tate Gallery by facilitating a national debate about the siting, nature, and purpose of the proposed National Gallery of British Art. Art critics, politicians, journalists and a variety of newspaper editors weighed in on whether Britain should create a museum of modern art, a museum of national art, or both. The understanding of British art as quintessentially modern at the time of the founding of the Gallery meant that from the beginning the Tate Gallery was founded as both the National Gallery of British Art and a museum of modern art. The changing definition of modern art in the twentieth century, however, created fractures between these two identities that eventually led to the split between Tate Britain and Tate Modern.

  17. Rael Artel Gallery Tartus ja Varssavis

    Index Scriptorium Estoniae

    2006-01-01

    Rael Artel Gallery : Non-Profit Project Space'i tegevusest Tartus. 27.04-27.05. 2006 Varssavis Warszawski Aktyw Artystov'i ruumides näitus "Estonian Video Art. The blood project", osalesid Flo Kasearu, Gert Hatsukov, Külli K. Kaats, Allan Tõnissoo, Marko Nautras, Tanja Muravskaja ja Airi Triisberg

  18. Solid-state reaction in Ti/Ni multilayered films studied by using magneto-optical spectroscopy

    CERN Document Server

    Lee, Y P; Kim, K W; Kim, C G; Kudryavtsev, Y V; Nemoshkalenko, V V; Szymanski, B

    2000-01-01

    A comparative study of the solid-state reaction (SSR) in a series of Ti/Ni multilayered films (MLDs) with bilayer periods of 0.65-22.2 nm and a constant Ti to Ni sublayer thickness ratio was performed by using experimental and computer-simulated magneto-optical (MO) spectroscopy based on different models of MLFs, as well as x-ray diffraction (XRD). The spectral and sublayer thickness dependences of the MO properties of the Ti/Ni MLFs were explained on the basis of the electromagnetic theory. The existence of a threshold nominal Ni-sublayer thickness of about 3 nm for the as-deposited Ti/Ni MLF to observe of the equatorial Kerr effect was explained by a solid-state reaction which formed nonmagnetic alloyed regions between pure components during the MLF deposition. The SSR in the Ti/Ni MLFs, which was caused by the low temperature annealing, led to the formation of an amorphous Ti-Ni alloy and took place mainly in the Ti/Ni MLFs with ''thick'' sublayers. For the caes of Ti/Ni MLFs, the MO approach turned out to...

  19. Spark plasma sintering of TiNi nano-powders for biological application

    International Nuclear Information System (INIS)

    Fu, Y Q; Gu, Y W; Shearwood, C; Luo, J K; Flewitt, A J; Milne, W I

    2006-01-01

    Nano-sized TiNi powder with an average size of 50 nm was consolidated using spark plasma sintering (SPS) at 800 deg. C for 5 min. A layer of anatase TiO 2 coating was formed on the sintered TiNi by chemical reaction with a hydrogen peroxide (H 2 O 2 ) solution at 60 deg. C followed by heat treatment at 400 deg. C to enhance the bioactivity of the metal surface. Cell culture using osteoblast cells and a biomimetic test in simulated body fluid proved the biocompatibility of the chemically treated SPS TiNi

  20. Evaluating two infiltration gallery designs for managed aquifer recharge using secondary treated wastewater.

    Science.gov (United States)

    Bekele, Elise; Toze, Simon; Patterson, Bradley; Fegg, Wolfgang; Shackleton, Mark; Higginson, Simon

    2013-03-15

    As managed aquifer recharge (MAR) becomes increasingly considered for augmenting water-sensitive urban areas, fundamental knowledge of the achievable scale, longevity and maintenance requirements of different options will become paramount. This paper reports on a 39 month pilot scale MAR scheme that infiltrated secondary treated wastewater through unsaturated sand into a limestone and sand aquifer. Two types of infiltration gallery were constructed to compare their hydraulic performance, one using crushed, graded gravel, the other using an engineered leach drain system (Atlantis Leach System(®)). Both galleries received 25 kL of nutrient-rich, secondary treated wastewater per day. The Atlantis gallery successfully infiltrated 17 ML of treated wastewater over three years. The slotted distribution pipe in the gravel gallery became clogged with plant roots after operating for one year. The infiltration capacity of the gravel gallery could not be restored despite high pressure cleaning, thus it was replaced with an Atlantis system. Reduction in the infiltration capacity of the Atlantis system was only observed when inflow was increased by about 3 fold for two months. The performance of the Atlantis system suggests it is superior to the gravel gallery, requiring less maintenance within at least the time frame of this study. The results from a bromide tracer test revealed a minimum transport time of 3.7 days for the recharged water to reach the water table below 9 m of sand and limestone. This set a limit on the time available for attenuation by natural treatment within the unsaturated zone before it recharged groundwater. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  1. Whisper: Tracing the Spatiotemporal Process of Information Diffusion in Real Time.

    Science.gov (United States)

    Cao, Nan; Lin, Yu-Ru; Sun, Xiaohua; Lazer, D; Liu, Shixia; Qu, Huamin

    2012-12-01

    When and where is an idea dispersed? Social media, like Twitter, has been increasingly used for exchanging information, opinions and emotions about events that are happening across the world. Here we propose a novel visualization design, "Whisper", for tracing the process of information diffusion in social media in real time. Our design highlights three major characteristics of diffusion processes in social media: the temporal trend, social-spatial extent, and community response of a topic of interest. Such social, spatiotemporal processes are conveyed based on a sunflower metaphor whose seeds are often dispersed far away. In Whisper, we summarize the collective responses of communities on a given topic based on how tweets were retweeted by groups of users, through representing the sentiments extracted from the tweets, and tracing the pathways of retweets on a spatial hierarchical layout. We use an efficient flux line-drawing algorithm to trace multiple pathways so the temporal and spatial patterns can be identified even for a bursty event. A focused diffusion series highlights key roles such as opinion leaders in the diffusion process. We demonstrate how our design facilitates the understanding of when and where a piece of information is dispersed and what are the social responses of the crowd, for large-scale events including political campaigns and natural disasters. Initial feedback from domain experts suggests promising use for today's information consumption and dispersion in the wild.

  2. Whispering gallery modes for elastic waves in disk resonators

    Directory of Open Access Journals (Sweden)

    S. Kaproulias

    2011-12-01

    Full Text Available The resonant modes of elastic waves in disk resonators are computationally studied with the finite difference time domain method. Different materials examined for the disk such as platinum and silicon. The effect of a glass substrate is also important especially in the case of silicon disks because of the similarity of sound velocities and mass densities between the two materials. The possibility of using those structures as sensors is also considered.

  3. Broad spectral response photodetector based on individual tin-doped CdS nanowire

    Directory of Open Access Journals (Sweden)

    Weichang Zhou

    2014-12-01

    Full Text Available High purity and tin-doped 1D CdS micro/nano-structures were synthesized by a convenient thermal evaporation method. SEM, EDS, XRD and TEM were used to examine the morphology, composition, phase structure and crystallinity of as-prepared samples. Raman spectrum was used to confirm tin doped into CdS effectively. The effect of impurity on the photoresponse properties of photodetectors made from these as-prepared pure and tin-doped CdS micro/nano-structures under excitation of light with different wavelength was investigated. Various photoconductive parameters such as responsivity, external quantum efficiency, response time and stability were analyzed to evaluate the advantage of doped nanowires and the feasibility for photodetector application. Comparison with pure CdS nanobelt, the tin-doped CdS nanowires response to broader spectral range while keep the excellect photoconductive parameters. Both trapped state induced by tin impurity and optical whispering gallery mode microcavity effect in the doped CdS nanowires contribute to the broader spectral response. The micro-photoluminescence was used to confirm the whispering gallery mode effect and deep trapped state in the doped CdS nanowires.

  4. Alloying process of sputter-deposited Ti/Ni multilayer thin films

    International Nuclear Information System (INIS)

    Cho, H.; Kim, H.Y.; Miyazaki, S.

    2006-01-01

    Alloying process of a Ti/Ni multilayer thin film was investigated in detail by differential scanning calorimetry (DSC), X-ray diffractometry (XRD) and transmission electron microscopy (TEM). The Ti/Ni multilayer thin film was prepared by depositing Ti and Ni layers alternately on a SiO 2 /Si substrate. The number of each metal layer was 100, and the total thickness was 3 μm. The alloy composition was determined as Ti-51 at.%Ni by electron probe micro analysis (EPMA). The DSC curve exhibited three exothermic peaks at 621, 680 and 701 K during heating the as-sputtered multilayer thin film. In order to investigate the alloying process, XRD and TEM observation was carried out for the specimens heated up to various temperatures with the heating rate same as the DSC measurement. The XRD profile of the as-sputtered film revealed only diffraction peaks of Ti and Ni. But reaction layers of 3 nm in thickness were observed at the interfaces of Ti and Ni layers in cross-sectional TEM images. The reaction layer was confirmed as an amorphous phase by the nano beam diffraction analysis. The XRD profiles exhibited that the intensity of Ti diffraction peak decreased in the specimen heat-treated above 600 K. The peak from Ni became broad and shifted to lower diffraction angle. The amorphous layer thickened up to 6 nm in the specimen heated up to 640 K. The diffraction peak corresponding to Ti-Ni B2 phase appeared and the peak from Ni disappeared for the specimen heated up to 675 K. The Ti-Ni B2 crystallized from the amorphous reaction layer. After further heating above the third exothermic peak, the intensity of the peak from the Ti-Ni B2 phase increased, the peak from Ti disappeared and the peaks corresponding to Ti 2 Ni appeared. The Ti 2 Ni phase was formed by the reaction of the Ti-Ni B2 and Ti

  5. The Cosmology Gallery: Unity through diversity in a vast and awe-inspiring universe.

    Science.gov (United States)

    Goldsmith, John

    2011-06-01

    Scientists, artists, religious and cultural leaders have come together to create the Cosmology Gallery at the Gravity Discovery Centre (GDC) located 70 km north of Perth, Western Australia. The Cosmology Gallery exhibitions include the multicultural cosmology artworks, Celestial Visions astronomical photography exhibition and the Timeline of the Universe. The multicultural cosmology artworks are new artworks inspired by Australian Indigenous, Christian, Buddhist, Islamic, Hindu, scientific and technological perspectives of the universe. The Celestial Visions exhibition features astronomical events above famous landmarks, including Stonehenge and the Pyramids. The AUD 400,000+ project was funded by Lotterywest, Western Australia and the Cosmology Gallery was officially opened in July 2008 by the Premier of Western Australia.

  6. Crystal structure of TiNi nanoparticles obtained by Ar ion beam deposition

    International Nuclear Information System (INIS)

    Castro, A. Torres; Cuellar, E. Lopez; Mendez, U. Ortiz; Yacaman, M. Jose

    2008-01-01

    Nanoparticles are a state of matter that have properties different from either molecules or bulk solids, turning them into a very interesting class of materials to study. In the present work, the crystal structure of TiNi nanoparticles obtained by ion beam deposition is characterized. TiNi nanoparticles were obtained from TiNi wire samples by sputtering with Ar ions using a Gatan precision ion polishing system. The TiNi nanoparticles were deposited on a Lacey carbon film that was used for characterization by transmission electron microscopy. The nanoparticles were characterized by high-resolution transmission electron microscopy, high-angle annular dark-field imaging, electron diffraction, scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy. Results of nanodiffraction seem to indicate that the nanoparticles keep the same B2 crystal structure as the bulk material but with a decreased lattice parameter

  7. Prospect of Ti-Ni shape memory alloy applied in reactor structures

    International Nuclear Information System (INIS)

    Duan Yuangang

    1995-01-01

    Shape memory effect mechanism, physical property, composition, manufacturing process and application in mechanical structure of Ti-Ni shape memory alloy are introduced. Applications of Ti-Ni shape memory alloy in reactor structure are prospected and some necessary technical conditions of shape memory alloy applied in the reactor structure are put forward initially

  8. Physicists tackles questions of tiny dimensions

    CERN Multimedia

    Moran, Barbara

    2003-01-01

    Today's physicists have a dilemna: they are using two separate theories to describe the universe. General relativity, which describes gravity, works for large objects like planets. Quantum mechanics, which involves the other forces, works for tiny objects like atoms. Unfortunately, the two theories don't match up.

  9. Advances in developing TiNi nanoparticles

    International Nuclear Information System (INIS)

    Castro, A. Torres; Cuellar, E. Lopez; Mendez, U. Ortiz; Yacaman, M. Jose

    2006-01-01

    The elaboration of nanoparticles has become a field of great interest for many scientists. Nanoparticles possess different properties than those ones shown in bulk materials. Shape memory alloys have the exceptional ability to recuperate its original shape by simple heating after being 'plastically' deformed. When this process is originated, important changes in properties, as mechanical and electrical, are developed in bulk material. If there is possible to obtain nanoparticles with shape memory effects, these nanoparticles could be used in the elaboration of nanofluids with the ability to change their electrical and thermal conductivity with temperature changes, i.e., smart nanofluids. In this work, some recent results and discussion of TiNi nanoparticles obtained by ion beam milling directly from a TiNi wire with shape memory are presented. The nanoparticles obtained by this process are about 2 nm of diameter with a composition of Ti-41.0 at.% Ni. Synthesized nanoparticles elaborated by this method have an ordered structure

  10. Optical transport and statistics of radiative losses in disordered chains of microspheres

    International Nuclear Information System (INIS)

    Deng Chaosheng; Xu Hui; Deych, Lev

    2010-01-01

    Optical transport in a one-dimensional chain of microspherical resonators with size disorder is studied in the spectral range of high-Q whispering gallery modes. An ab initio approach is used to develop a theoretical framework for analysis of steady-state transport parameters with main emphasis on properly defined radiative loss coefficient. Probability distribution and scaling properties of the latter are established and explained.

  11. A 'tiny-orange' spectrometer for electrons

    International Nuclear Information System (INIS)

    Silva, N.C. da.

    1990-01-01

    An tiny-orange electron spectrometer was designed and constructed using flat permanent magnets and a surface barrier detector. The transmission functions of different system configurations were determined for energies in the 200-1100 KeV range. A mathematical model for the system was developed. (L.C.J.A.)

  12. Thermal simulation of storage in TSS-Galleries

    International Nuclear Information System (INIS)

    Lain Huerta, R.; Martinez Santiago, T.; Ramirez Oyangueren, P.

    1993-01-01

    This report describes the experiment ''thermal simulation of storage in TSS-galleries'' what is been developed in salt mine of Asse, Germany. The report has 3 part: 1) Analysis of objectives and general description of boundary layers. 2) Geomechanics parameters of salt mine. 3) Thermal modelization, thermomechanics modelization and data acquisition

  13. Viability of microcomputed tomography to study tropical marine worm galleries in humid muddy sediments

    Energy Technology Data Exchange (ETDEWEB)

    Pennafirme, Simone F., E-mail: sipennafirme@gmail.com [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Biologia. Dept. de Biologia Marinha; Machado, Alessandra S.; Lima, Inaya; Suzuki, Katia N.; Lopes, Ricardo T., E-mail: machado@lin.ufrj.br, E-mail: inaya@lin.ufrj.br, E-mail: norisuzuki6@yahoo.com.br, E-mail: ricardo@lin.ufj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), RJ (Brazil). Lab. de Instrumentacao Nuclear

    2013-07-01

    Bioturbation is an ecological process driven by organisms, which transports nutrients and gases from air/water to sediment through their galleries, by the time they feed, burrow and/or construct galleries. This exchange is vital to the maintenance of micro and macrobenthic organisms, mainly in muddy flat environments. Species with distinct galleries could create levels of bioturbation, affecting the benthic interactions. In this sense, it is fundamental developing a non-destructive method that permits identifying/quantifying the properties of these galleries. The recent advances in micro-computed tomography are allowing the high resolution 3D images generation. However, once muddy sediments are rich in organic matter and interstitial water, these would lead to motion artifacts which could, in turn, decrease the accuracy of galleries identification/quantification. In this context, the aim of this study was to develop a protocol which combines laboratory experiments and microtomography analysis in order to generate accurate 3D images of the small marine worm's galleries within humid muddy sediments. The sediment was collected at both muddy flats of Surui's and Itaipu lagoon's mangroves (RJ-Brazil), sieved (0.5mm mesh) and introduced with one individual of the marine worm Laeonereis acuta (Nereididae, Polychaeta) in each acrylic corer holders (4.4cm of internal diameter). High energy microtomography scanner was used to obtain 3D images and the setup calibration was 130 kV and 61 mA. Each acquisition image time was among 4h and 6h. Several procedures of drying remained water inside the cores were performed aiming obtaining images without movement artifacts due to circulating water, and this issue was one of the main studied parameter. In order to investigate possible chemical effects, 2ml of formalin (35%) with menthol were added to the surface of the cores. The results show that although the drying time was appropriated, the chemicals created bubbles

  14. Viability of microcomputed tomography to study tropical marine worm galleries in humid muddy sediments

    International Nuclear Information System (INIS)

    Pennafirme, Simone F.; Machado, Alessandra S.; Lima, Inaya; Suzuki, Katia N.; Lopes, Ricardo T.

    2013-01-01

    Bioturbation is an ecological process driven by organisms, which transports nutrients and gases from air/water to sediment through their galleries, by the time they feed, burrow and/or construct galleries. This exchange is vital to the maintenance of micro and macrobenthic organisms, mainly in muddy flat environments. Species with distinct galleries could create levels of bioturbation, affecting the benthic interactions. In this sense, it is fundamental developing a non-destructive method that permits identifying/quantifying the properties of these galleries. The recent advances in micro-computed tomography are allowing the high resolution 3D images generation. However, once muddy sediments are rich in organic matter and interstitial water, these would lead to motion artifacts which could, in turn, decrease the accuracy of galleries identification/quantification. In this context, the aim of this study was to develop a protocol which combines laboratory experiments and microtomography analysis in order to generate accurate 3D images of the small marine worm's galleries within humid muddy sediments. The sediment was collected at both muddy flats of Surui's and Itaipu lagoon's mangroves (RJ-Brazil), sieved (0.5mm mesh) and introduced with one individual of the marine worm Laeonereis acuta (Nereididae, Polychaeta) in each acrylic corer holders (4.4cm of internal diameter). High energy microtomography scanner was used to obtain 3D images and the setup calibration was 130 kV and 61 mA. Each acquisition image time was among 4h and 6h. Several procedures of drying remained water inside the cores were performed aiming obtaining images without movement artifacts due to circulating water, and this issue was one of the main studied parameter. In order to investigate possible chemical effects, 2ml of formalin (35%) with menthol were added to the surface of the cores. The results show that although the drying time was appropriated, the chemicals created bubbles within the

  15. Ghost Whisperer's Ghost in the Machine: An example of pop cultural representation of virtual worlds

    DEFF Research Database (Denmark)

    Reinhard, CarrieLynn D.

    2009-01-01

    Analysis of an episode of the CBS series "Ghost Whisperer" for how it depicts a) what is a virtual world and b) the tensions that are involved in discussing the uses and effects of a virtual world.  Discussion focuses on the overriding negative reception of virtual worlds in popular culture due...

  16. Measurements of indoor 222Rn concentration in two art galleries

    International Nuclear Information System (INIS)

    Carneiro, Luana Gomes; Braz, Delson; Jesus, Edgar Francisco de; Cunha, Kenya Dias da; Medeiros, Geiza; Zouain, Felipe; Pitassi, Gabriel; Leite, Carlos Barros; Cardoso, Katia

    2009-01-01

    It is point out that radon and their decay products in environment give high dose to human lung. Studies indicate that the indoor radon inhalation by humans has been considered probably the second most important cause of lung cancer after of smoking. A passive-type radon detector was used for measuring indoor radon concentration in two art galleries at Rio de Janeiro city during 90 days January to March, 2009. The aim of this study is to evaluate the occupational and public radon exposure in art galleries and museums. This paper shows the preliminary results of samples collected at two art galleries located in Gavea, Rio de Janeiro city. 30 LEXAN (GE) track detectors were exposed in the air (indoor as well as outdoor). The samples were collected in the same building which is a construction of XIX century. The analysis of the results suggests that the 222 Rn concentration levels are different in both sampling site, in closed environmental, demonstrating that, although the construction materials are the same the absence of circulating air is a factor very important to increase the concentration of indoor Rn. (author)

  17. Leros: A Tiny Microcontroller for FPGAs

    DEFF Research Database (Denmark)

    Schoeberl, Martin

    2011-01-01

    Leros is a tiny microcontroller that is optimized for current low-cost FPGAs. Leros is designed with a balanced logic to on-chip memory relation. The design goal is a microcontroller that can be clocked in about half of the speed a pipelined on-chip memory and consuming less than 300 logic cells...

  18. Krasotshnõje snõ Sed Arte Gallery / Irina Butjajeva

    Index Scriptorium Estoniae

    Butjajeva, Irina

    2007-01-01

    Valgevene kunstnike Jelena Shlegeli, Vladimir Gontsharuki, Dmitri Zenkovitshi ja Dmitri Masli maalinäitus "Valgevene värvilised unenäod" Tallinna galeriis Aatrium. Näitust vahendas Sed Arte Gallery, galerist Olga Ljubaskina

  19. InfoGallery: Informative Arts Services for Physical Library Spaces

    DEFF Research Database (Denmark)

    Grønbæk, Kaj; Rohde, Anne; Sundararajah, Balasuthas

    2006-01-01

    Much focus in digital libraries research has been devoted to new online services rather than services for the visitors in the physical library. This paper describes InfoGallery, which is a web-based infrastructure for enriching the physical library space with informative art "exhibitions......" of digital library material and other relevant information, such as RSS news streams, event announcements etc. InfoGallery presents information in an aesthetically attractive manner on a variety of surfaces in the library, including cylindrical displays and floors. The infrastructure consists of a server...... structure, an editor application and a variety of display clients. The paper discusses the design of the infrastructure and its utilization of RSS, podcasts and manually edited news. Applications in the library domain are described and the experiences are discussed....

  20. Lab, Field, Gallery and Beyond

    DEFF Research Database (Denmark)

    Binder, Thomas; Koskinen, Ilpo; Redström, Johan

    2009-01-01

    Over the last ten years we have seen a growing number of researchers integrating design experiments in their research inquiries. Initially, this work borrowed heavily from neighboring fields, employing a dual strategy in which design experiments and their evaluation were largely treated as separate...... processes that were often carried out by different people. More recently, design researchers have developed several approaches that integrate design-specific work methods to research. This paper takes a methodological look at three such established approaches that we call Lab, Field, and Gallery. We...

  1. Revenge of tiny Miranda

    International Nuclear Information System (INIS)

    Goldreich, P.; Nicholson, P.

    1977-01-01

    Reference is made to Dermott and Gold (Nature 267: 590 (1977)) who proposed a resonance model for the rings of Uranus. They assumed that the rings are composed of small particles librating about stable resonances determined by pairs of satellites, either Ariel and Titania or Ariel and Oberon. They dismissed as insignificant resonances involving 'tiny Miranda'. It is reported here that, by a wide margin, the strongest resonances are all associated with Miranda. It is also shown that the hypothesis that the rings are made up of librating particles, whilst original and ingenious, is incorrect. (author)

  2. Cavity optomechanics in a levitated helium drop

    Science.gov (United States)

    Childress, L.; Schmidt, M. P.; Kashkanova, A. D.; Brown, C. D.; Harris, G. I.; Aiello, A.; Marquardt, F.; Harris, J. G. E.

    2017-12-01

    We describe a proposal for a type of optomechanical system based on a drop of liquid helium that is magnetically levitated in vacuum. In the proposed device, the drop would serve three roles: its optical whispering-gallery modes would provide the optical cavity, its surface vibrations would constitute the mechanical element, and evaporation of He atoms from its surface would provide continuous refrigeration. We analyze the feasibility of such a system in light of previous experimental demonstrations of its essential components: magnetic levitation of mm-scale and cm-scale drops of liquid He , evaporative cooling of He droplets in vacuum, and coupling to high-quality optical whispering-gallery modes in a wide range of liquids. We find that the combination of these features could result in a device that approaches the single-photon strong-coupling regime, due to the high optical quality factors attainable at low temperatures. Moreover, the system offers a unique opportunity to use optical techniques to study the motion of a superfluid that is freely levitating in vacuum (in the case of 4He). Alternatively, for a normal fluid drop of 3He, we propose to exploit the coupling between the drop's rotations and vibrations to perform quantum nondemolition measurements of angular momentum.

  3. Museums and art galleries as partners for public health interventions.

    Science.gov (United States)

    Camic, Paul M; Chatterjee, Helen J

    2013-01-01

    The majority of public health programmes are based in schools, places of employment and in community settings. Likewise, nearly all health-care interventions occur in clinics and hospitals. An underdeveloped area for public health-related planning that carries international implications is the cultural heritage sector, and specifically museums and art galleries. This paper presents a rationale for the use of museums and art galleries as sites for public health interventions and health promotion programmes through discussing the social role of these organisations in the health and well-being of the communities they serve. Recent research from several countries is reviewed and integrated into a proposed framework for future collaboration between cultural heritage, health-care and university sectors to further advance research, policy development and evidence-based practice.

  4. Engaging Families in the Galleries Using Design Thinking

    Science.gov (United States)

    Larson, Lucy

    2017-01-01

    The Palo Alto Art Center sought a solution to the challenge that loyal family audiences, visiting weekly for art studio classes, rarely visit the contemporary art exhibition galleries. This article relates the experience of using the human-centered design process, often called Design Thinking, as the methodology to create a solution for family…

  5. Role of Edge Inclination in an Optical Microdisk Resonator for Label-Free Sensing

    OpenAIRE

    Gandolfi, Davide; Ramiro-Manzano, Fernando; Rebollo, Francisco Javier Aparicio; Ghulinyan, Mher; Pucker, Georg; Pavesi, Lorenzo

    2015-01-01

    In this paper, we report on the measurement and modeling of enhanced optical refractometric sensors based on whispering gallery modes. The devices under test are optical microresonators made of silicon nitride on silicon oxide, which differ in their sidewall inclination angle. In our approach, these microresonators are vertically coupled to a buried waveguide with the aim of creating integrated and cost-effective devices. Device modeling shows that the optimization of the devic...

  6. A gallery support

    Energy Technology Data Exchange (ETDEWEB)

    Erokhin, A I; Orekhov, D M; Romanov, P D; Semenov, U N; Sokov, G D; Trubnikov, V P

    1981-10-15

    The gallery support includes a middle section consisting of forward and aft hydraulic walls, a roof timber and a foundation on which the cross beam is connected to a longitudinal element, and outer sections mounted on both sides of the longitudinal element behind the cross beam; these outer sections contain the roof timbers, the hydraulic walls and the foundations which are connected to the cross beam by a hydraulic jack. In order to increase the areas where it may be used, particularly for variable-level mining works, the connector between the longitudinal element and the cross beam is hinge mounted, while the roof timbers of the outer sections are connected together by an adjustible jack and are constructed to allow detachable beams to be mounted on them under the arched support; the forward hydraulic props of the mid section are mounted on the ends of the cross beam.

  7. What Can the Habitable Zone Gallery Do For You?

    Science.gov (United States)

    Gelino, Dawn M.; Kane, Stephen

    2015-12-01

    The Habitable Zone Gallery (www.hzgallery.org) came online in August 2011 as a service to the exoplanet community that provides Habitable Zone (HZ) information for each of the exoplanetary systems with known planetary orbital parameters. The service includes a sortable table, a plot with the period and eccentricity of each of the planets with respect to their time spent in the HZ, a gallery of known systems which plot the orbits and the location of the HZ with respect to those orbits, and orbital movies. Recently, we have added new features including: implementation of both conservative and optimistic HZs, more user-friendly table and movies, movies for circumbinary planets, and a count of planets whose orbits lie entirely within the system's HZ. Here we discuss various educational and scientific applications of the site such as target selection, exploring planets with eccentric or circumbinary orbits, and investigating habitability.

  8. Surface characterization of TiNi deformed by high-pressure torsion

    Energy Technology Data Exchange (ETDEWEB)

    Awang Shri, Dayangku Noorfazidah [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Structural Materials Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan); Tsuchiya, Koichi, E-mail: tsuchiya.koichi@nims.go.jp [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Structural Materials Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan); Yamamoto, Akiko [Biomaterials Unit, International Center for Material Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044 (Japan)

    2014-01-15

    Effect of grain refinements and amorphization by high-pressure torsion (HPT) on surface chemistry was investigated on TiNi. X-ray diffraction and micro-Vickers tests were used to check the phase changes and hardness before and after HPT. X-ray photoelectron spectroscopy was used to observe the changes in the natural passive film formation on the surface. Phase analysis reveals the change of crystalline TiNi to nanostructured one with increased hardness with straining by HPT. Grain refinement and amorphization caused by HPT reduce the amount of metallic Ni in the passive films and also increase the thickness of the film.

  9. Experiences from a Real-Time Mobile Collaborative Writing System in an Art Gallery

    DEFF Research Database (Denmark)

    Korn, Matthias; Polli, Anna Maria; Klokmose, Clemens Nylandsted

    We present first experiences from Local Area Artworks, a system enabling collaborative art interpretation on-site, deployed during an exhibition in a local art gallery. Through the system, we explore ways to re-connect people to local places by making use of their personal mobile devices...... as interfaces to the shared physical space. With a collocated collaborative writing system in the semi-public space of a gallery, we encourage local art discussions and provide a platform for the public to actively participate in interpretations of individual artworks. In this paper, we focus on the experiences...

  10. A study on the shape memory characteristics of Ti-Ni50-x-Pdx alloys

    International Nuclear Information System (INIS)

    Lee, H. W.; Chun, B. S.; Oh, S. J.; Kuk, I.H.

    1991-01-01

    The shape memory characteristics in TiNi alloys are greatly effected by the alloy composition and heat treatment condition. The present work was aimed to investigate the effect of Pd x (x=5,10,15,20) addition on the shape memory chracteristics of TiNi alloys by means of electrical resistance measurement. X-ray diffraction, differential scanning calorimetry and electron dispersive analysis X-ray measurement. The results obtained from this study are as follows; 1. The martensitic transformation start temperature, Ms of Ti-Ni 50-x -Pd x alloys decreased considerably with the increase of Pd content up to 10at%, whereas increased largely with the increase of Pd content in the alloys with Pd content more than 15at%. 2. The Ms temperature of Ti-Ni 50-x -Pd x alloys with cold working was significantly lower than that of the fully annealed alloys because high density dislocation has been introduced by the cold working which suppressed the martensitic transformation. (Author)

  11. Fabrication, microstructure and stress effects in sputtered TiNi thin films

    International Nuclear Information System (INIS)

    Grummon, D.S.

    2000-01-01

    Sputtered thin films of equiatomic TiNi and TiNiX ternary alloys have excellent mechanical properties and exhibit robust shape-memory and transformational superelasticity. Furthermore, the energetic nature of the sputter deposition process allows the creation of highly refined microstructures that are difficult to achieve by melt-solidification. The present paper will present recent work on the relationship between processing, microstructure and properties of binary TiNi thin films, focusing primarily on residual stresses, kinetics of stress-relaxation and crystallization, and fine grain sizes achievable using hot-substrate direct crystallization. (orig.)

  12. The kinetics of Cr layer coated on TiNi films for hydrogen absorption

    Indian Academy of Sciences (India)

    The effect of hydrogen absorption on electrical resistance with temperature for TiNi and TiNi–Cr thin films was investigated. The TiNi thin films of thickness 800 Å were deposited at different angles ( = 0°, 30°, 45°, 60° and 75°) under 10−5 Torr pressure by thermal evaporation on the glass substrate at room temperature.

  13. Mechanical behavior of galleries in deep clay - Study of a concrete example

    International Nuclear Information System (INIS)

    Rousset, G.; Jehan, R.A.; Bonne, A.; Fernique, J.C.

    1985-01-01

    At important depths such as those envisaged for the construction of a radioactive waste disposal, clay appears to be a material of rather weak resistance. One of the first problems to be studied is the technical feasibility of a disposal facility. The time-dependent and strain-softening behavior of the clay plays a significant role in the long term stability of the lined galleries. The in-situ measurements carried out during the digging of a gallery in Boom clay (Belgium), under a 250 m overburden are presented. The data obtained are analyzed by means of an elastoviscoplastic model including strain softening behavior of the clay

  14. Confocal microscopy and spectroscopy of nanocrystals on a high-Q microsphere resonator

    International Nuclear Information System (INIS)

    Goetzinger, S; Menezes, L de S; Benson, O; Talapin, D V; Gaponik, N; Weller, H; Rogach, A L; Sandoghdar, V

    2004-01-01

    We report on experiments where we used a home-made confocal microscope to excite single nanocrystals on a high-Q microsphere resonator. In that way spectra of an individual quantum emitter could be recorded. The Q factor of the microspheres coated with nanocrystals was still up to 10 9 . We also demonstrate the use of a prism coupler as a well-defined output port to collect the fluorescence of an ensemble of nanocrystals coupled to whispering-gallery modes

  15. Moths are not silent, but whisper ultrasonic courtship songs

    DEFF Research Database (Denmark)

    Nakano, R; Takanashi, T; Fujii, T

    2009-01-01

    ) were recently shown to whisper extremely low-intensity ultrasonic courtship songs close to females. Since low sound levels will prevent eavesdropping by predators, parasites and conspecific rivals, we predicted low intensity ultrasound communication to be widespread among moths. Here we tested 13...... species of moths including members of the Noctuidae, Arctiidae, Geometridae and Crambidae. Males of nine species, 70%, produced broadband ultrasound close to females. Peak frequencies ranged from 38 to above 100 kHz. All sounds were of low intensity, 43-76 dB SPL at 1 cm [64+/-10 dB peSPL (mean +/- s......Ultrasonic hearing is widespread among moths, but very few moth species have been reported to produce ultrasounds for sexual communication. In those that do, the signals are intense and thus well matched for long distance communication. By contrast, males of the Asian corn borer moth (Crambidae...

  16. Struggling to Hear? Tiny Devices Can Keep You Connected

    Science.gov (United States)

    ... Human Services Search form Search Site Menu Home Latest Issue Past Issues Special Issues Subscribe May 2018 Print this issue Struggling to Hear? Tiny Devices Can Keep You Connected En español Send us ...

  17. Whisper, a resonance sounder and wave analyser: Performances and perspectives for the Cluster mission

    DEFF Research Database (Denmark)

    Decreau, P.M.E.; Fergeau, P.; KrannoselsKikh, V.

    1997-01-01

    The WHISPER sounder on the Cluster spacecraft is primarily designed to provide an absolute measurement of the total plasma density within the range 0.2-80 cm(-3). This is achieved by means of a resonance sounding technique which has already proved successful in the regions to be explored. The wav...... in the electron foreshock and solar wind, to investigations about small-scale structures via density and high-frequency emission signatures, and to the analysis of the non-thermal continuum in the magnetosphere....

  18. Cavitation erosion of Ti-Ni shape memory alloy deposited coatings and Fe base shape memory alloy solid

    International Nuclear Information System (INIS)

    Hattori, Shuji; Fujisawa, Seiji; Owa, Tomonobu

    2007-01-01

    In this study, cavitation erosion tests were carried out by using thermal spraying and deposition of Ti-Ni shape memory alloy for the surface coating. The results show the test speciment of Ti-Ni thermal spraying has many initial defects, so that the erosion resistance is very low. The erosion resistance of Ti-Ni deposit is about 5-10 times higher than that of SUS 304, thus erosion resistance of Ti-Ni deposit is better than that of Ti-Ni thermal spraying. The cavitation erosion tests were carried out by using Fe-Mn-Si with shape memory and gunmetal with low elastic modulus. The erosion resistance of Fe-Mn-Si shape memory alloy solid is about 9 times higher than that of SUS 304. The erosion resistance of gunmetal is almost the same as SUS 304, because the test specimen of gunmetal has many small defects on the original surface. (author)

  19. In situ crystallization of sputter-deposited TiNi by ion irradiation

    International Nuclear Information System (INIS)

    Ikenaga, Noriaki; Kishi, Yoichi; Yajima, Zenjiro; Sakudo, Noriyuki

    2013-01-01

    Highlights: ► We developed a sputtering deposition process equipped with an ion irradiation system. ► Ion irradiation enables crystallization at lower substrate temperature. ► Ion fluence has an effective range for low-temperature crystallization. ► Crystallized films made on polyimide by the process show the shape memory effect. -- Abstract: TiNi is well known as a typical shape-memory alloy, and the shape-memory property appears only when the structure is crystalline. Until recently, the material has been formed as amorphous film by single-target sputtering deposition at first and then crystallized by being annealed at high temperature over 500 °C. Therefore, it has been difficult to make crystalline TiNi film directly on a substrate of polymer-based material because of the low heat resistance of substrate. In order to realize an actuator from the crystallized TiNi film on polymer substrates, the substrate temperature should be kept below 200 °C throughout the whole process. In our previous studies we have found that deposited film can be crystallized at very low temperature without annealing but with simultaneous irradiation of Ar ions during sputter-deposition. And we have also demonstrated the shape-memory effect with the TiNi film made by the new process. In order to investigate what parameters of the process contribute to the low-temperature crystallization, we have focused to the ion fluence of the ion irradiation. Resultantly, it was found that the transition from amorphous structure to crystal one has a threshold range of ion fluence

  20. On the Problem of Filtration to an Imperfect Gallery in a Pressureless Bed

    Science.gov (United States)

    Bereslavskii, É. N.; Dudina, L. M.

    2018-01-01

    The problem of plane steady-state filtration in a pressureless bed to an imperfect gallery in the presence of evaporation from the flow free surface is considered. To study such type of flow, a mixed boundary-value problem of the theory of analytical functions is formulated and solved with application of the Polubarinova-Kochina method. Based on the model suggested, an algorithm for computing the discharge of the gallery and the ordinate of free surface emergence to the impermeable screen is developed. A detailed hydrodynamic analysis of the influence of all physical parameters of the model on the desired filtration characteristics is given.

  1. XPS characterization of surface and interfacial structure of sputtered TiNi films on Si substrate

    International Nuclear Information System (INIS)

    Fu Yongqing; Du Hejun; Zhang, Sam; Huang Weimin

    2005-01-01

    TiNi films were prepared by co-sputtering TiNi and Ti targets. X-ray photoelectron spectroscopy (XPS) was employed to study surface chemistry of the films and interfacial structure of Si/TiNi system. Exposure of the TiNi film to the ambient atmosphere (23 deg. C and 80% relatively humidity) facilitated quick adsorption of oxygen and carbon on the surface. With time, carbon and oxygen content increased drastically at the surface, while oxygen diffused further into the layer. After a year, carbon content at the surface became as high as 65.57% and Ni dropped below the detection limit of XPS. Depth profiling revealed that significant inter-diffusion occurred between TiNi film and Si substrate with a layer of 90-100 nm. The detailed bond changes of different elements with depth were obtained using XPS and the formation of titanium silicides at the interface were identified

  2. Flexible Microsphere-Embedded Film for Microsphere-Enhanced Raman Spectroscopy.

    Science.gov (United States)

    Xing, Cheng; Yan, Yinzhou; Feng, Chao; Xu, Jiayu; Dong, Peng; Guan, Wei; Zeng, Yong; Zhao, Yan; Jiang, Yijian

    2017-09-27

    Dielectric microspheres with extraordinary microscale optical properties, such as photonic nanojets, optical whispering-gallery modes (WGMs), and directional antennas, have drawn interest in many research fields. Microsphere-enhanced Raman spectroscopy (MERS) is an alternative approach for enhanced Raman detection by dielectric microstructures. Unfortunately, fabrication of microsphere monolayer arrays is the major challenge of MERS for practical applications on various specimen surfaces. Here we report a microsphere-embedded film (MF) by immersing a highly refractive microsphere monolayer array in the poly(dimethylsiloxane) (PDMS) film as a flexible MERS sensing platform for one- to three-dimensional (1D to 3D) specimen surfaces. The directional antennas and wave-guided whispering-gallery modes (WG-WGMs) contribute to the majority of Raman enhancement by the MFs. Moreover, the MF can be coupled with surface-enhanced Raman spectroscopy (SERS) to provide an extra >10-fold enhancement. The limit of detection is therefore improved for sensing of crystal violet (CV) and Sudan I molecules in aqueous solutions at concentrations down to 10 -7 M. A hybrid dual-layer microsphere enhancer, constructed by depositing a MF onto a microsphere monolayer array, is also demonstrated, wherein the WG-WGMs become dominant and boost the enhancement ratio >50-fold. The present work opens up new opportunities for design of cost-effective and flexible MERS sensing platforms as individual or associated techniques toward practical applications in ultrasensitive Raman detection.

  3. Multimode laser emission from free-standing cylindrical microcavities

    Energy Technology Data Exchange (ETDEWEB)

    Peter, Jaison, E-mail: jaisonpeter@cusat.ac.in; Radhakrishnan, P.; Nampoori, V.P.N.; Kailasnath, M.

    2014-05-01

    We report a well resolved whispering gallery mode (WGM) laser emission from a free-standing microring cavity based on a dye doped hollow polymer optical fiber (DDHPOF), which is transversely pumped by a pulsed Nd:YAG laser. The microring laser is characterized by a well-defined, low threshold pump power at which the emission spectral intensity dramatically increases and collapses into several dominant microcavity laser modes with reduced mode spacing and high Q-value. Resonant modes are excited inside the gain medium which is strongly confined along the radial direction so that the spacing of lasing modes is controlled by the diameter of the cylindrical microcavity. A variation in the free spectral range of WGM spectra from 0.23 to 0.09 nm coupled with a red-shift is observed with an increase in the diameter of DDHPOFs. - Highlights: • Different diameter free-standing cylindrical microcavity lasers have been fabricated and their performances have been evaluated. • The microring laser is characterized by a well-defined, low threshold pump power, with reduced mode spacing and high Q-value. • When the diameter of DDHPOF increases, the number of lasing peaks increases along with the decrease of the FSR as observed from our studies. • It is also found that whispering gallery lasing envelope is shifted from 559 to 571 nm (Stokes shift) with the diameter.

  4. From tiny microalgae to huge biorefineries

    OpenAIRE

    Gouveia, L.

    2014-01-01

    Microalgae are an emerging research field due to their high potential as a source of several biofuels in addition to the fact that they have a high-nutritional value and contain compounds that have health benefits. They are also highly used for water stream bioremediation and carbon dioxide mitigation. Therefore, the tiny microalgae could lead to a huge source of compounds and products, giving a good example of a real biorefinery approach. This work shows and presents examples of experimental...

  5. Commissioning and Performance Analysis of WhisperGen Stirling Engine

    Science.gov (United States)

    Pradip, Prashant Kaliram

    Stirling engine based cogeneration systems have potential to reduce energy consumption and greenhouse gas emission, due to their high cogeneration efficiency and emission control due to steady external combustion. To date, most studies on this unit have focused on performance based on both experimentation and computer models, and lack experimental data for diversified operating ranges. This thesis starts with the commissioning of a WhisperGen Stirling engine with components and instrumentation to evaluate power and thermal performance of the system. Next, a parametric study on primary engine variables, including air, diesel, and coolant flowrate and temperature were carried out to further understand their effect on engine power and efficiency. Then, this trend was validated with the thermodynamic model developed for the energy analysis of a Stirling cycle. Finally, the energy balance of the Stirling engine was compared without and with heat recovery from the engine block and the combustion chamber exhaust.

  6. Limitations of constitutive relations for TiNi shape memory alloys

    International Nuclear Information System (INIS)

    Tang, W.; Sandstroem, R.

    1995-01-01

    Phase transformation tensor Ω in the constitutive equation proposed by Tanaka has been evaluated by employing experimental data of TiNi alloys in a constrained recovery process. It demonstrates that the absolute value of Ω for the constrained recovery process is typically about 0.6 ∼ 0.7 x 10 3 MPa, which is much smaller than that for the stress - induced martensitic transformation (typically 2.5 ∼ 3.5 x 10 3 ). Based on the evaluated results for Ω, predicted recovery stress - temperature relations by the constitutive equation are compared with the experimental data for TiNi rods under different strains. Big discrepancy exists for large strain conditions. Several transformation kinetic expressions are examined for the constitutive relation of the constrained recovery process. (orig.)

  7. Memorializing the Wars of Religion in Early Seventeenth-Century French Picture Galleries : Protestants and Catholics Painting the Contested Past

    NARCIS (Netherlands)

    van der Linden, David

    2017-01-01

    This article examines how Protestant and Catholic elites in early seventeenth-century France memorialized the Wars of Religion in purpose-built picture galleries. Postwar France remained a divided nation, and portrait galleries offered a sectarian memory of the conflict, glorifying party heroes.

  8. Research on megawatt gyrotrons, January 1983-December 1984

    International Nuclear Information System (INIS)

    Read, M.E.

    1984-01-01

    During the last several years, NRL has performed research on concepts for high power gyrotrons. The work funded by the Department of Energy has been in support of industrial development of high frequency (60 to 140 GHz) CW gyrotrons, with NRL research being on the origination, development, and testing of advanced concepts. The research performed under this agreement has included experimental work on quasi-optical and complex cavity gyrotrons and theoretical efforts on these concepts as well as whispering gallery gyrotrons

  9. Etude théorique et expérimentale des résonances de galerie de microsphères de silice: pièges à photons pour des expériences d'électrodynamique en cavité

    OpenAIRE

    Collot , Laurent

    1994-01-01

    This thesis is devoted to the study of very high Q whispering gallery modes in silica microspheres, about 100μm in diameter. For these resonances the electromagnetic field propagates along an equatorial surface ring with tranverse dimensions of the order of the wavelength. These guided modes have very low losses. They exhibit a remarkable combination of strong localization of the field in a small volume and very long storage times for the photons. These two properties render these microsphere...

  10. THE ROLE OF TINY GRAINS ON THE ACCRETION PROCESS IN PROTOPLANETARY DISKS

    International Nuclear Information System (INIS)

    Bai Xuening

    2011-01-01

    Tiny grains such as polycyclic aromatic hydrocarbons (PAHs) have been thought to dramatically reduce the coupling between the gas and magnetic fields in weakly ionized gas such as in protoplanetary disks (PPDs) because they provide a tremendous surface area to recombine free electrons. The presence of tiny grains in PPDs thus raises the question of whether the magnetorotational instability (MRI) is able to drive rapid accretion consistent with observations. Charged tiny grains have similar conduction properties as ions, whose presence leads to qualitatively new behaviors in the conductivity tensor, characterized by n-bar /n e >1, where n e and n-bar denote the number densities of free electrons and all other charged species, respectively. In particular, Ohmic conductivity becomes dominated by charged grains rather than by electrons when n-bar /n e exceeds about 10 3 , and Hall and ambipolar diffusion (AD) coefficients are reduced by a factor of ( n-bar /n e ) 2 in the AD-dominated regime relative to that in the Ohmic regime. Applying the methodology of Bai, we find that in PPDs, when PAHs are sufficiently abundant (∼> 10 -9 per H 2 molecule), there exists a transition radius r trans of about 10-20 AU, beyond which the MRI active layer extends to the disk midplane. At r trans , the optimistically predicted MRI-driven accretion rate M-dot is one to two orders of magnitude smaller than that in the grain-free case, which is too small compared with the observed rates, but is in general no smaller than the predicted M-dot with solar-abundance 0.1 μm grains. At r > r trans , we find that, remarkably, the predicted M-dot exceeds the grain-free case due to a net reduction of AD by charged tiny grains and reaches a few times 10 -8 M sun yr -1 . This is sufficient to account for the observed M-dot in transitional disks. Larger grains (∼> 0.1 μm) are too massive to reach such high abundance as tiny grains and to facilitate the accretion process.

  11. Reporting on What Jane Saw 2.0: Female Celebrity and Sensationalism in Boydell’s Shakespeare Gallery

    Directory of Open Access Journals (Sweden)

    Janine Barchas

    2015-03-01

    Full Text Available This essay reports on ongoing efforts to build an accurate digital model of John Boydell’s popular Shakespeare Gallery precisely as it looked in August 1796—when a 20-year-old Jane Austen visited London’s sites, staying within a ten-minute walk from the gallery. The essay argues for the substantial difference between studying Boydell’s pictures in a paper volume (whether as lists, illustrations in books, or engraved folio plates and viewing them as an exhibition of paintings on walls, albeit virtual ones. For example, the digital reconstruction illuminated commissions from several female participants in Boydell’s male-dominated gallery, especially Angelica Kauffman (1741-1807 and Anne Seymour Damer (1749-1828. In addition, the essay also recounts how the celebrity of model Emma Hart/Hamilton (1765-1815 safeguarded one Boydell painting from oblivion while The Shakespeare Gallery proved the site of a strange form of self-promotion practiced by actress Mary Wells (1762-1829. Our digital visualization of an historic exhibition in 1796 brought the controversial celebrity of a few women artists into focus. In sum, this essay shows DH methodology in action while sampling what might be gleaned when digital tools serve historical scholarship in the humanities.

  12. Ultrasonic sounding and monitoring of the excavation damaged zone in a soft supported gallery

    International Nuclear Information System (INIS)

    Balland, Cyrille; Souley, Mountaka; Morel, Jacques

    2012-01-01

    Document available in extended abstract form only. Under high in situ stresses and high anisotropic stress ratios, the excavation of underground openings generally causes the creation of a disturbed (EdZ: Excavation disturbed Zone) and/or damaged (EDZ: Excavation Damaged Zone) zone, resulting from the initiation and growth of cracks and fractures and by a redistribution and rearrangement of the initial stresses. Due to the modifications of mechanical and hydro-mechanical properties in the EdZ/EDZ, the latter constitute a potential risk for the efficiency of the geologic and/or engineered barriers. To estimate the performance of a site of radioactive waste storage, it is essential to know the geometry, the extensions of the EdZ/EDZ, the density of cracks, their connectivity and the variations of permeability which can result from it. In particular, their extension depends on numerous factors among which the nature of the rock, the pre-existent fractures and their reactivation, the initial stress field (magnitudes and/or rate of anisotropy), the time, the geometry and the techniques of excavations etc.. In addition, the evolution of EdZ/EDZ properties in the medium term is little or poorly known, particularly under the influence of environmental conditions such as the re-confining by near field rock creep in contact with a rigid structural support or the evolution of hydric conditions (desaturation and re-saturation). Ultrasonic experimentation under the OHZ experiment has been implemented to characterize the EDZ extension and its evolution in time according to the structural support type (soft or rigid) and the environmental conditions present in the laboratory. This study consists of two experimental components: (1) the prior auscultation of the sole and face of the gallery by ultrasonic transmission tomography, (2) the monitoring the EDZ and the analysis of measurable changes in the propagation of ultrasonic waves in the medium term. Mechanical modelling of the

  13. Micromechanical Analysis of Crack Closure Mechanism for Intelligent Material Containing TiNi Fibers

    Science.gov (United States)

    Araki, Shigetoshi; Ono, Hiroyuki; Saito, Kenji

    In our previous study, the micromechanical modeling of an intelligent material containing TiNi fibers was performed and the stress intensity factor KI at the tip of the crack in the material was expressed in terms of the magnitude of the shape memory shrinkage of the fibers and the thermal expansion strain in the material. In this study, the value of KI at the tip of the crack in the TiNi/epoxy material is calculated numerically by using analytical expressions obtained in our first report. As a result, we find that the KI value decreases with increasing shrink strain of the fibers, and this tendency agrees with that of the experimental result obtained by Shimamoto etal.(Trans. Jpn. Soc. Mech. Eng., Vol. 65, No. 634 (1999), pp. 1282-1286). Moreover, there exists an optimal value of the shrink strain of the fibers to make the KI value zero. The change in KI with temperature during the heating process from the reference temperature to the inverse austenitic finishing temperature of TiNi fiber is also consistent with the experimental result. These results can be explained by the changes in the shrink strain, the thermal expansion strain, and the elastic moduli of TiNi fiber with temperature. These results may be useful in designing intelligent materials containing TiNi fibers from the viewpoint of crack closure.

  14. The Habitable Zone Gallery 2.0: The Online Exoplanet System Visualization Suite

    Science.gov (United States)

    Chandler, C. O.; Kane, S. R.; Gelino, D. M.

    2017-11-01

    The Habitable Zone Gallery 2.0 provides new and improved visualization and data analysis tools to the exoplanet habitability community and beyond. Modules include interactive habitable zone plotting and downloadable 3D animations.

  15. Fast Response Shape Memory Effect Titanium Nickel (TiNi) Foam Torque Tubes

    Science.gov (United States)

    Jardine, Peter

    2014-01-01

    Shape Change Technologies has developed a process to manufacture net-shaped TiNi foam torque tubes that demonstrate the shape memory effect. The torque tubes dramatically reduce response time by a factor of 10. This Phase II project matured the actuator technology by rigorously characterizing the process to optimize the quality of the TiNi and developing a set of metrics to provide ISO 9002 quality assurance. A laboratory virtual instrument engineering workbench (LabVIEW'TM')-based, real-time control of the torsional actuators was developed. These actuators were developed with The Boeing Company for aerospace applications.

  16. Galled by the Gallbladder?: Your Tiny, Hard-Working Digestive Organ

    Science.gov (United States)

    ... Galled by the Gallbladder? Your Tiny, Hard-Working Digestive Organ En español Send us your comments Most ... among the most common and costly of all digestive system diseases. By some estimates, up to 20 ...

  17. Laser welding of Ti-Ni type shape memory alloy

    International Nuclear Information System (INIS)

    Hirose, Akio; Araki, Takao; Uchihara, Masato; Honda, Keizoh; Kondoh, Mitsuaki.

    1990-01-01

    The present study was undertaken to apply the laser welding to the joining of a shape memory alloy. Butt welding of a Ti-Ni type shape memory alloy was performed using 10 kW CO 2 laser. The laser welded specimens showed successfully the shape memory effect and super elasticity. These properties were approximately identical with those of the base metal. The change in super elasticity of the welded specimen during tension cycling was investigated. Significant changes in stress-strain curves and residual strain were not observed in the laser welded specimen after the 50-time cyclic test. The weld metal exhibited the celler dendrite. It was revealed by electron diffraction analysis that the phase of the weld metal was the TiNi phase of B2 structure which is the same as the parent phase of base metal and oxide inclusions crystallized at the dendrite boundary. However, oxygen contamination in the weld metal by laser welding did not occur because there was almost no difference in oxygen content between the base metal and the weld metal. The transformation temperatures of the weld metal were almost the same as those of the base metal. From these results, laser welding is applicable to the joining of the Ti-Ni type shape memory alloy. As the application of laser welding to new shape memory devices, the multiplex shape memory device of welded Ti-50.5 at % Ni and Ti-51.0 at % Ni was produced. The device showed two-stage shape memory effects due to the difference in transformation temperature between the two shape memory alloys. (author)

  18. Australian doctors and the visual arts. Part 4. Doctors as supporters of art galleries and artists in Victoria.

    Science.gov (United States)

    Hamilton, D G

    1986-07-07

    The contribution of doctors to the visual arts is being discussed in a series of six articles. Doctor-artists in New South Wales and Victoria, and doctors as collectors, donors, gallery supporters and writers in New South Wales, have been discussed in earlier articles. This, the fourth article, deals with doctors as supporters of art galleries and artists in Victoria.

  19. Towards a fully integrated optical gyroscope using whispering gallery modes resonators

    Science.gov (United States)

    Amrane, T.; Jager, J.-B.; Jager, T.; Calvo, V.; Léger, J.-M.

    2017-11-01

    Since the developments of lasers and the optical fibers in the 70s, the optical gyroscopes have been subject to an intensive research to improve both their resolution and stability performances. However the best optical gyroscopes currently on the market, the ring laser gyroscope and the interferometer fiber optic gyroscope are still macroscopic devices and cannot address specific applications where size and weight constraints are critical. One solution to overcome these limitations could be to use an integrated resonator as a sensitive part to build a fully Integrated Optical Resonant Gyroscope (IORG). To keep a high rotation sensitivity, which is usually degraded when downsizing this kind of optical sensors based on the Sagnac effect, the resonator has to exhibit a very high quality factor (Q): as detailed in equation (1) where the minimum rotation rate resolution for an IORG is given as a function of the resonator characteristics (Q and diameter D) and of the global system optical system characteristics (i.e. SNR and bandwidth B), the higher the Q×D product, the lower the resolution.

  20. Calcium fluoride whispering gallery mode optical resonator with reduced thermal sensitivity

    Science.gov (United States)

    Savchenkov, Anatoliy; Matsko, Andrey

    2018-03-01

    We demonstrate a crystalline CaF2 resonator with thermal sensitivity of the optical modes approaching zero. The resonator is made by laminating a calcium fluoride layer forming an optical monolithic cavity with ceramic compensation layers. The ceramics is characterized with negative thermal expansion coefficient achievable in a certain temperature range. The thermally compensated resonator has a potential application for laser frequency stabilization.

  1. Numerical Investigation of Terahertz Emission Properties of Microring Difference-Frequency Resonators

    DEFF Research Database (Denmark)

    Iwaszczuk, Krzysztof; Bisgaard, Christer Zoffmann; Andronico, Alessio

    2013-01-01

    We investigate the electromagnetic design of whispering gallery mode (WGM) terahertz (THz) resonators. Terahertz radiation is generated by difference-frequency mixing of two electrically pumped high-order near-infrared laser WGM's at room temperature in the active cavity. Due to the leaky nature...... this symmetry by modification of the dielectric environment of the resonator, and demonstrate a fabrication-optimized structure based on a concentric grating design which efficiently couples the emitted radiation into a narrow, near-gaussian forward-propagating cone of well-defined linear or circular...

  2. Introducing New Library Services: Nuclear Malaysia Gallery Photos and Videos

    International Nuclear Information System (INIS)

    Mohd Hafizal Yusof; Nasaruddin Ahmad; Habibah Adnan

    2015-01-01

    The main purpose of the existing of library is to preserve books and journals for the organizations main business. The role of library itself is to organize the books such as borrowing and renewal services as consulting their customers on getting the best references for the customers need and demand. Nowadays, the role of library also expands and the need for storing and preserving non-monograph resources such as photo and video also increase. Follow that current situation, Nuclear Malaysia's Library also take a step forwards by introducing new services so called Photo and Video Gallery. Realizing that Nuclear Malaysia also have their valuable photo and video that contains so called memorable moment and must be preserve for future reference, the management of Nuclear Malaysia's Library have decided to buy the system so called P-Canvas. The main purpose of this paper is to explain the library new services, Photo and Video Gallery, development and advantage of this system in storing and preserving Nuclear Malaysia's photo and video. (author)

  3. Community Litter Arthropods Associated cerrado and gallery forest, in the Ecological Station Sierra Das Araras - Mato Grosso, Brazil

    Directory of Open Access Journals (Sweden)

    Daniela Cristina Zardo

    2015-12-01

    Full Text Available The litter arthropod fauna distinguishes itself by its importance in nutrient cycling and organic matter degradation. This invertebrate fauna has been emphasized as crucial for the processes that structure ecosystems. This study aims to evaluate and compare the arthropod fauna composition, richness and abundance in litter of two environments: the savanna and the gallery forest at Serra das Araras Ecological Station , Mato Grosso. To collect the arthropods a 120m transects for each habitat was delimited, divided into six points in each environment. For all the litter collection points, we marked a plot measuring 1.0 x 1.0 m, totalizing 6m2 for an environment, where the arthropods found were identified by order level, and the individuals were grouped into morphospecies. The total arthropods richness found in the savanna and in the gallery forest areas was 38 morphospecies, 28 morphospecies were found in the savanna and 20 in the gallery forest, with total abundance of 381 individuals, being 226 individuals collected in the savanna and 155 individuals in the gallery forest. The more abundant morphospecies in the savanna and gallery forest belonged to Hymenoptera and Isoptera orders, with 10 and 4 morphospecies and abundance of 263 and 78 individuals respectively. The greatest organism richness and abundance occurred in the savanna, because it is a tropical environment with the greatest biodiversity, especially regarding its insect fauna, and this diversity is primarily concerned with the variety of habitats that the environment provides , which gives the species shelter, food and reproduction sites.

  4. Remote Whispering Applying Time Reversal

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Brian Eric [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-07-16

    The purpose of this project was to explore the use of time reversal technologies as a means for communication to a targeted individual or location. The idea is to have the privacy of whispering in one’s ear, but to do this remotely from loudspeakers not located near the target. Applications of this work include communicating with hostages and survivors in rescue operations, communicating imaging and operational conditions in deep drilling operations, monitoring storage of spent nuclear fuel in storage casks without wires, or clandestine activities requiring signaling between specific points. This technology provides a solution in any application where wires and radio communications are not possible or not desired. It also may be configured to self calibrate on a regular basis to adjust for changing conditions. These communications allow two people to converse with one another in real time, converse in an inaudible frequency range or medium (i.e. using ultrasonic frequencies and/or sending vibrations through a structure), or send information for a system to interpret (even allowing remote control of a system using sound). The time reversal process allows one to focus energy to a specific location in space and to send a clean transmission of a selected signal only to that location. In order for the time reversal process to work, a calibration signal must be obtained. This signal may be obtained experimentally using an impulsive sound, a known chirp signal, or other known signals. It may also be determined from a numerical model of a known environment in which the focusing is desired or from passive listening over time to ambient noise.

  5. Synergetic scattering of SiO2 and Ag nanoparticles for light-trapping enhancement in organic bulk heterojunction

    Science.gov (United States)

    Yang, Huan; Ding, Qiuyu; Li, Ben Q.; Jiang, Xinbing; Zhang, Manman

    2018-02-01

    Though noble metal nanoparticles have been explored to enhance the performance of the organic solar cell, effect of dielectric nanoparticles, and coupled effect of dielectric and metal nanoparticles, have rarely been reported, if at all, on organic solar cell. This work reports an experimental study on synergetic scattering of SiO2 and Ag nanoparticles in a bulk organic heterojunction for the broadband light absorption enhancement. The wavelength scale SiO2 particles were arranged as a monolayer on the surface of the solar cell to guide incident light into the active layer and prolong the effective optical length of the entered energy. This is achieved by the excitation of whispering gallery modes in SiO2 nanoparticles and by leaky mode radiation. When small size Ag particles were incorporated into the transport layer of the solar cell, synergetic scattering of SiO2 and Ag nanoparticles is formed by coupling of the whispering gallery mode of closely arranged SiO2 particles atop and collaborative localized surface plasma resonance scattering of Ag nanoparticles dispersed in the transport layer. As a result, the performance of the organic solar cell is greatly enhanced and the short-circuit current density has an improvement of 42.47%. Therefore, the organic solar cell incorporated with SiO2 and Ag particles presents a meaningful strategy to achieve high energy-harvesting performance. [Figure not available: see fulltext.

  6. A study of grandparents and grandchildren as visitors to museums and art galleries in the UK

    Directory of Open Access Journals (Sweden)

    Ela Beaumont

    2005-11-01

    Full Text Available This paper discusses one aspect of a major research project funded by the Arts and Humanities Research Council of family group visitors to museums and galleries in the UK. Grandparents visiting with their grandchildren are a little understood phenomenon in terms of visitor research and this paper aims to address that balance. The research project focuses on three art galleries and museums in the UK where 44 sets of grandparents were interviewed during the initial stages of the research. Findings have shown a number of interesting facets, some of which are presented in this paper. Grandparents are motivated to visit the museum with their grandchildren in the main because they are seeking an entertaining visit, a day out that is also educational and linked to school projects. They are likely to be the children’s primary carers as parents are out to work and the destination might not link with their own interests but those of the parents. They have social roles to play in their grandchildren’s lives. They often seek activity or workshops in the museum/art gallery that will be of benefit for their grandchildren and encourage them to explore the activities provided. These and other aspects are discussed within the paper. We conclude by suggesting how the findings can be used to inform more sophisticated approaches to ‘family friendly’ initiatives in museums and art galleries.

  7. The role of gallery forests in maintaining Phlebotominae populations: potential Leishmania spp. vectors in the Brazilian savanna

    Directory of Open Access Journals (Sweden)

    Tâmara Dias Oliveira Machado

    Full Text Available BACKGROUND Knowledge on synanthropic phlebotomines and their natural infection by Leishmania is necessary for the identification of potential areas for leishmaniasis occurrence. OBJECTIVE To analyse the occurrence of Phlebotominae in gallery forests and household units (HUs in the city of Palmas and to determine the rate of natural infection by trypanosomatids. METHODS Gallery forests and adjacent household areas were sampled on July (dry season and November (rainy season in 2014. The total sampling effort was 960 HP light traps and eight Shannon traps. Trypanosomatids were detected in Phlebotominae females through the amplification of the SSU rDNA region, and the positive samples were used in ITS1-PCR. Trypanosomatid species were identified using sequencing. FINDINGS A total of 1,527 sand flies representing 30 species were captured in which 949 (28 spp. and 578 (22 spp. were registered in July and November, respectively. In July, more specimens were captured in the gallery forests than in the HUs, and Nyssomyia whitmani was particularly frequent. In November, most of the specimens were found in the HUs, and again, Ny. whitmani was the predominant species. Lutzomyia longipalpis was commonly found in domestic areas, while Bichromomyia flaviscutellata was most frequent in gallery forests. Molecular analysis of 154 pools of females (752 specimens identified Leishmania amazonensis, L. infantum, and Crithidia fasciculata in Ny. whitmani, as well as L. amazonensis in Lu. longipalpis, Trypanosoma sp. and L. amazonensis in Pintomyia christenseni, and L. amazonensis in both Psathyromyia hermanlenti and Evandromyia walkeri. MAIN CONCLUSIONS These results show the importance of gallery forests in maintaining Phlebotominae populations in the dry month, as well as their frequent occurrence in household units in the rainy month. This is the first study to identify Leishmania, Trypanosoma, and Crithidia species in Phlebotominae collected in Palmas, Tocantins

  8. Chaco Chachalaca (Ortalis canicollis, Wagler, 1830 feeding ecology in a gallery forest in the South Pantanal (Brazil

    Directory of Open Access Journals (Sweden)

    J. Ragusa-Netto

    Full Text Available Cracids are generalist frugivores, which often exploit plant food resources such as flowers and leaves, mainly when fruit production declines. The Chaco chachalaca (Ortalis canicollis is the most abundant cracid in the Pantanal (Brazil, and particularly common in the gallery forests. However, the factors related to their occurrence in this habitat type are unclear. In this study I describe the feeding habits and feeding niche breadth fluctuations of the Chaco chachalaca in relation to food resources abundance and diversity at the Miranda river gallery forest (Southern Pantanal. I also analyzed the relationships between Chaco chachalacas feeding activity and food resources abundance. This parameter (flowers and fruits exhibited significant seasonal differences of abundance in which flowers were plentiful at the end of the dry, while fruits were abundant during the early wet season. However, food resources diversity to Chaco chachalacas exhibited no seasonal difference. Their feeding activity paralleled the availability of food resources, so that when some items were massively available an enhanced number of Chaco chachalacas foraged in the gallery forest, particularly during the prolonged dry season when they extensively used flowers and Genipa americana fruits. In fact, the Chaco chachalaca feeding niche breadth value presented low values in this period, while high values were common in the rest of the year. The flexible diet of this cracid, potentially favors their year round presence in the gallery forest, mainly during the prolonged dry season when the propensity for famine might be high. Since the Chaco chachalaca is among the largest and most abundant canopy frugivores in the gallery forest, it may contribute to forest regeneration, an underscored role due to the impact of annual floods and meandering dynamics on tree loss.

  9. The role of gallery forests in maintaining Phlebotominae populations: potential Leishmania spp. vectors in the Brazilian savanna.

    Science.gov (United States)

    Machado, Tâmara Dias Oliveira; Minuzzi-Souza, Thaís Tâmara Castro; Ferreira, Tauana de Sousa; Freire, Luciana Pereira; Timbó, Renata Velôzo; Vital, Tamires Emanuele; Nitz, Nadjar; Silva, Mariana Neiva; Santos, Alcinei de Souza; Sales, Nathyla Morgana Cunha; Obara, Marcos Takashi; Andrade, Andrey José de; Gurgel-Gonçalves, Rodrigo

    2017-10-01

    Knowledge on synanthropic phlebotomines and their natural infection by Leishmania is necessary for the identification of potential areas for leishmaniasis occurrence. To analyse the occurrence of Phlebotominae in gallery forests and household units (HUs) in the city of Palmas and to determine the rate of natural infection by trypanosomatids. Gallery forests and adjacent household areas were sampled on July (dry season) and November (rainy season) in 2014. The total sampling effort was 960 HP light traps and eight Shannon traps. Trypanosomatids were detected in Phlebotominae females through the amplification of the SSU rDNA region, and the positive samples were used in ITS1-PCR. Trypanosomatid species were identified using sequencing. A total of 1,527 sand flies representing 30 species were captured in which 949 (28 spp.) and 578 (22 spp.) were registered in July and November, respectively. In July, more specimens were captured in the gallery forests than in the HUs, and Nyssomyia whitmani was particularly frequent. In November, most of the specimens were found in the HUs, and again, Ny. whitmani was the predominant species. Lutzomyia longipalpis was commonly found in domestic areas, while Bichromomyia flaviscutellata was most frequent in gallery forests. Molecular analysis of 154 pools of females (752 specimens) identified Leishmania amazonensis, L. infantum, and Crithidia fasciculata in Ny. whitmani, as well as L. amazonensis in Lu. longipalpis, Trypanosoma sp. and L. amazonensis in Pintomyia christenseni, and L. amazonensis in both Psathyromyia hermanlenti and Evandromyia walkeri. These results show the importance of gallery forests in maintaining Phlebotominae populations in the dry month, as well as their frequent occurrence in household units in the rainy month. This is the first study to identify Leishmania, Trypanosoma, and Crithidia species in Phlebotominae collected in Palmas, Tocantins, Brazil.

  10. Abundance and frugivory of the toco toucan (Ramphastos toco in a gallery forest in Brazil's Southern Pantanal

    Directory of Open Access Journals (Sweden)

    J. Ragusa-Netto

    Full Text Available Unlike other toucan species, the Toco toucan (Ramphastos toco - the largest Ramphastidae - usually inhabits dry semi-open areas. This conspicuous canopy frugivore uses a large home range that includes a variety of vegetation types, among which gallery forests are widely cited as important to this species. However, the factors relating to the occurrence of Toco toucans in such habitats are unclear. I studied the abundance of Toco toucans as well as the availability of fleshy fruit in a gallery forest in the southern Pantanal (sub-region of Miranda, Brazil, in order to assess the relationship between these parameters. Also, I examined toucan foraging activity to analyze its relationship with both toucan abundance and fruit availability. The presence of the Toco toucan was more common in the gallery forest from the middle to the end of the dry season and during the middle of the wet season. Toucans foraged for fleshy fruits, mainly Genipa americana, Ficus luschnatiana, and Cecropia pachystachya fruits, feeding mostly on G. americana (by far the favorite food resource and F. luschnatiana fruits during the dry season, while C. pachystachya fruits were important in the wet season. Toco toucans foraged particularly heavily (> 80% of foraging activity on G. americana fruits during the latter part of the dry season, when fleshy fruit availability declined sharply. Toco toucan abundance in the gallery forest was associated with the availability of the most commonly consumed fleshy fruits, and also with its foraging activity. This finding suggests that the Toco toucan moved to the gallery forest periodically in response to the availability of abundant food resources, especially the G. americana fruits widely available and exploited during the severely dry season. Therefore, these fruits potentially contribute to Toco toucan persistence in the South Pantanal during the harshest period of the year.

  11. Abundance and frugivory of the Toco toucan (Ramphastos toco) in a gallery forest in Brazil's southern Pantanal.

    Science.gov (United States)

    Ragusa-Netto, J

    2006-02-01

    Unlike other toucan species, the Toco toucan (Ramphastos toco)--the largest Ramphastidae--usually inhabits dry semi-open areas. This conspicuous canopy frugivore uses a large home range that includes a variety of vegetation types, among which gallery forests are widely cited as important to this species. However, the factors relating to the occurrence of Toco toucans in such habitats are unclear. I studied the abundance of Toco toucans as well as the availability of fleshy fruit in a gallery forest in the southern Pantanal (sub-region of Miranda, Brazil), in order to assess the relationship between these parameters. Also, I examined toucan foraging activity to analyze its relationship with both toucan abundance and fruit availability. The presence of the Toco toucan was more common in the gallery forest from the middle to the end of the dry season and during the middle of the wet season. Toucans foraged for fleshy fruits, mainly Genipa americana, Ficus luschnatiana, and Cecropia pachystachya fruits, feeding mostly on G. americana (by far the favorite food resource) and F. luschnatiana fruits during the dry season, while C. pachystachya fruits were important in the wet season. Toco toucans foraged particularly heavily (> 80% of foraging activity) on G. americana fruits during the latter part of the dry season, when fleshy fruit availability declined sharply. Toco toucan abundance in the gallery forest was associated with the availability of the most commonly consumed fleshy fruits, and also with its foraging activity. This finding suggests that the Toco toucan moved to the gallery forest periodically in response to the availability of abundant food resources, especially the G. americana fruits widely available and exploited during the severely dry season. Therefore, these fruits potentially contribute to Toco toucan persistence in the South Pantanal during the harshest period of the year.

  12. Virginia Tech researchers find tiny bubbles a storehouse of knowledge

    OpenAIRE

    Trulove, Susan

    2005-01-01

    Fluid inclusions -- tiny bubbles of fluid or vapor trapped inside rock as it forms-- are clues to the location of ores and even petroleum; and they are time capsules that contain insights on the power of volcanos and hints of life in the universe.

  13. Preparation of the PRACLAY demonstration and confirmation experiments: construction of the PRACLAY gallery

    International Nuclear Information System (INIS)

    Bastiaens, W.

    2009-01-01

    The PRACLAY demonstration and confirmation experiments contribute to the Belgian research, development and demonstration programme to assess the safety and feasibility of geological disposal of radioactive waste in Boom Clay. Within this programme, the large scale PRACLAY heater experiment aims to verify that Boom Clay is suitable to host heat emitting radioactive waste. A 35 m long section of an experimental gallery in the underground research facility HADES (at 225 m depth) will be heated up to 95 degrees Celsius during ten years. The heater experiment focuses on the response of the host rock to the thermal load. The figure below shows the experimental lay-out. In 2007, an important milestone was reached with the realisation of the PRACLAY gallery (45 m long, external diameter 2.5 m)

  14. Atom-Photon Coupling from Nitrogen-vacancy Centres Embedded in Tellurite Microspheres

    Science.gov (United States)

    Ruan, Yinlan; Gibson, Brant C.; Lau, Desmond W. M.; Greentree, Andrew D.; Ji, Hong; Ebendorff-Heidepriem, Heike; Johnson, Brett C.; Ohshima, Takeshi; Monro, Tanya M.

    2015-06-01

    We have developed a technique for creating high quality tellurite microspheres with embedded nanodiamonds (NDs) containing nitrogen-vacancy (NV) centres. This hybrid method allows fluorescence of the NVs in the NDs to be directly, rather than evanescently, coupled to the whispering gallery modes of the tellurite microspheres at room temperature. As a demonstration of its sensing potential, shifting of the resonance peaks is also demonstrated by coating a sphere surface with a liquid layer. This new approach is a robust way of creating cavities for use in quantum and sensing applications.

  15. A proposed experiment on ball lightning model

    International Nuclear Information System (INIS)

    Ignatovich, Vladimir K.; Ignatovich, Filipp V.

    2011-01-01

    Highlights: → We propose to put a glass sphere inside an excited gas. → Then to put a light ray inside the glass in a whispering gallery mode. → If the light is resonant to gas excitation, it will be amplified at every reflection. → In ms time the light in the glass will be amplified, and will melt the glass. → A liquid shell kept integer by electrostriction forces is the ball lightning model. -- Abstract: We propose an experiment for strong light amplification at multiple total reflections from active gaseous media.

  16. Routes to spatiotemporal chaos in Kerr optical frequency combs.

    Science.gov (United States)

    Coillet, Aurélien; Chembo, Yanne K

    2014-03-01

    We investigate the various routes to spatiotemporal chaos in Kerr optical frequency combs, obtained through pumping an ultra-high Q-factor whispering-gallery mode resonator with a continuous-wave laser. The Lugiato-Lefever model is used to build bifurcation diagrams with regards to the parameters that are externally controllable, namely, the frequency and the power of the pumping laser. We show that the spatiotemporal chaos emerging from Turing patterns and solitons display distinctive dynamical features. Experimental spectra of chaotic Kerr combs are also presented for both cases, in excellent agreement with theoretical spectra.

  17. Design of a 17.14 GHz quasi-optical pulse compressor

    International Nuclear Information System (INIS)

    Petelin, M. I.; Kuzikov, S. V.; Danilov, Yu. Yu.; Granatstein, V. L.; Nusinovich, G. S.

    1999-01-01

    A quasi-optical version of the ring cavity pulse compressor is considered. This concept is based on the coupling of the input wave to a whispering gallery mode of a barrel-like cavity due to helical corrugations of the cavity wall. Low-power tests of the prototype were carried out at 11.4 GHz and demonstrated reasonable agree-ment between experimental data and theoretical predictions. The design of a similar pulse compressor at 17.14 GHz compatible with the 17.14 GHz, 100 MW gyroklystron currently under development at the University of Maryland is presented

  18. Visual events and the friendly eye: modes of educating vision in new educational settings in Danish art galleries

    DEFF Research Database (Denmark)

    Illeris, Helene

    2009-01-01

      New, experimental educational settings such as ‘art laboratories', ‘digital workshops' and ‘theme-based tours' are important to the processes of change towards more inclusive practices, which have been initiated in many Danish art galleries. While traditional gallery education was constructed...... as visual events, and it discusses how ‘the desiring eye' of some constructivist approaches, along with traditional practices of looking, have contributed to the formation of the modern, autonomous individual. The second part of the article analyses two cases from Danish art galleries and, inspired by Mieke...... in order to stimulate the ‘disciplined eye' or the ‘aesthetic eye' of the visitors, this article aims to discuss the practices of looking encouraged by contemporary and experimental educational projects. The first part of the article develops a theoretical perspective on educational settings conceived...

  19. Natural regeneration in several environments of the Capetinga gallery forest at Agua Limpa Farm (DF

    Directory of Open Access Journals (Sweden)

    Jeanine Maria Felfili

    2009-03-01

    Full Text Available The Capetinga gallery forest is located at Agua Limpa Farm, in the Federal District, Brazil. The floristic compositionand structure of the natural regeneration at the edges and in the interior of the gallery forest at the watershed of the Capetinga stream was studied to detect floristic and structural patterns related to the forest environments. Thirty (5x5m plots were placed in each environment to sample saplings, individuals from 1,0m high with diameter at the steam base under 5,0cm. Within these plots, (2x2m sub-plots were allocated to sample seedlings, individuals lower than 1,0m height. The sampled plots were distant to the stream bank to minimize the humidity effect. Shannon & Wiener diversity index varied from 2,86 (seedlings at the edges to 3,51 (saplings at the interior and it was higher in the interior for both categories. Sørensen s similarity index varied from 0.474 for seedlings (comparingedges with interior to 0.735 (seedlings and saplings at the edges. Czekanowski indices were low and reflected the high differentiationin structure from plot to plot in the same gallery forest. TWINSPAN classification suggested two distinct communities for saplings forboth conditions, formed by species accordingly to their requirements for light and water. No differentiation was detected for seedlingsbetween the environments indicating a low response of plants at an early stage to the environmental conditions within the forest. TheCapetinga gallery forest suffered disturbances by fire and the small variations in species composition and vegetation structurebetween environments suggests that most of the natural regeneration is tolerant to light.

  20. Shape memory characteristics of sputter-deposited Ti-Ni thin films

    International Nuclear Information System (INIS)

    Miyazaki, Shuichi; Ishida, Akira.

    1994-01-01

    Ti-Ni shape memory alloy thin films were deposited using an RF magnetron sputtering apparatus. The as-sputtered films were heat-treated in order to crystallize and memorize. After the heat treatment, the shape memory characteristics have been investigated using DSC and thermomechanical tests. Upon cooling the thin films, the solution-treated films showed a single peak in the DSC curve indicating a single stage transformation occurring from B2 to the martensitic phase, while the age-treated films showed double peaks indicating a two-stage transformation, i.e., from B2 to the R-phase, then to the martensitic phase. A perfect shape memory effect was achieved in these sputter-deposited Ti-Ni thin films in association both with the R-phase and martensitic transformations. Transformation temperatures increased linearly with increasing applied stress. The transformation strain also increased with increasing stress. The shape memory characteristics were strongly affected by heat-treatment conditions. (author)

  1. Effect of phase formation on valence band photoemission and photoresonance study of Ti/Ni multilayers using synchrotron radiation

    International Nuclear Information System (INIS)

    Bhatt, Pramod; Chaudhari, S.M.

    2006-01-01

    This paper presents investigation of Ti-Ni alloy phase formation and its effect on valence band (VB) photoemission and photoresonance study of as-deposited as well as annealed Ti/Ni multilayers (MLs) up to 600 deg. C using synchrotron radiation. For this purpose [Ti (50 A)/Ni (50 A)]X 10 ML structures were deposited by using electron-beam evaporation technique under ultra-high vacuum (UHV) conditions. Formation of different phases of Ti-Ni alloy due to annealing treatment has been confirmed by the X-ray diffraction (XRD) technique. The XRD pattern corresponding as-deposited ML sample shows crystalline nature of both Ti and Ni deposited layers, whereas 300 deg. C annealed ML sample show solid-state reaction (SSR) leading to amorphization and subsequent recrystallisation at higher temperatures of annealing (≥400 deg. C) with the formation of TiNi, TiNi 3 and Ti 2 Ni alloy phases. The survey scans corresponding to 400, 500 and 600 deg. C annealed ML sample shows interdiffusion and intermixing of Ni atoms into Ti layers leading to chemical Ti-Ni alloys phase formation at interface. The corresponding recorded VB spectra using synchrotron radiation at 134 eV on as-deposited ML sample with successive sputtering shows alternately photoemission bands due to Ti 3d and Ni 3d, respectively, indicating there is no mixing of the consequent layers and any phase formation at the interface during deposition. However, ML samples annealed at higher temperatures of annealing, particularly at 400, 500 and 600 deg. C show a clear shift in Ni 3d band and its satellite peak position to higher BE side indicates Ti-Ni alloy phase formation. In addition to this, reduction of satellite peak intensity and Ni 3d density of states (DOS) near Fermi level is also observed due to Ti-Ni phase formation with higher annealing temperatures. The variable photon energy VB measurements on as-deposited and ML samples annealed at 400 deg. C confirms existence and BE position of observed Ni 3d satellite

  2. Fabrication of TiNi/CFRP smart composite using cold drawn TiNi wires

    Science.gov (United States)

    Xu, Ya; Otsuka, Kazuhiro; Toyama, Nobuyuki; Yoshida, Hitoshi; Jang, Byung-Koog; Nagai, Hideki; Oishi, Ryutaro; Kishi, Teruo

    2002-07-01

    In recent years, pre-strained TiNi shape memory alloys (SMA) have been used for fabricating smart structure with carbon fibers reinforced plastics (CFRP) in order to suppress microscopic mechanical damages. However, since the cure temperature of CFRP is higher than the reverse transformation temperatures of TiNi SMA, special fixture jigs have to be used for keeping the pre-strain during fabrication, which restricted its practical application. In order to overcome this difficulty, we developed a new method to fabricate SMA/CFRP smart composites without using special fixture jigs by controlling the transformation temperatures of SMA during fabrication. This method consists of using heavily cold-worked wires to increase the reverse transformation temperatures, and of using flash electrical heating of the wires after fabrication in order to decrease the reverse transformation temperatures to a lower temperature range again without damaging the epoxy resin around SMA wires. By choosing proper cold-working rate and composition of TiNi alloys, the reverse transformation temperatures were well controlled, and the TiNi/CFRP hybrid smart composite was fabricated without using special fixture jigs. The damage suppressing effect of cold drawn wires embedded in CFRP was confirmed.

  3. The application of Tiny Triplet Finder (TTF) in BTeV pixel trigger

    International Nuclear Information System (INIS)

    Wu, Jin-Yuan; Wang, M.; Gottschalk, E.; Shi, Z.; Fermilab

    2006-01-01

    We describe a track segment recognition scheme called the Tiny Triplet Finder (TTF) that involves grouping of three hits satisfying a constraint such as forming of a straight line. The TTF performs this O(n 3 ) function in O(n) time, where n is number of hits in each detector plane. The word ''tiny'' reflects the fact that the FPGA resource usage is small. The number of logic elements needed for the TTF is O(Nlog(N)), where N is the number of bins in the coordinate considered, which for large N, is significantly smaller than O(N 2 ) needed for typical implementations of similar functions. The TTF is also suitable for software implementations as well as many other pattern recognition problems

  4. From the galleries to the clinic: applying art museum lessons to patient care.

    Science.gov (United States)

    Miller, Alexa; Grohe, Michelle; Khoshbin, Shahram; Katz, Joel T

    2013-12-01

    Increasingly, medical educators integrate art-viewing into curricular interventions that teach clinical observation-often with local art museum educators. How can cross-disciplinary collaborators explicitly connect the skills learned in the art museum with those used at the bedside? One approach is for educators to align their pedagogical approach using similar teaching methods in the separate contexts of the galleries and the clinic. We describe two linked pedagogical exercises--Visual Thinking Strategies (VTS) in the museum galleries and observation at the bedside--from "Training the Eye: Improving the Art of Physical Diagnosis," an elective museum-based course at Harvard Medical School. It is our opinion that while strategic interactions with the visual arts can improve skills, it is essential for students to apply them in a clinical context with faculty support-requiring educators across disciplines to learn from one another.

  5. New numerical modelling of the mechanical long-term behaviour of the GMR gallery in ANDRA's Underground Research Laboratory

    International Nuclear Information System (INIS)

    Blanco Martin, L.; Hadj-Hassen, F.; Tijani, M.; Armand, G.

    2011-01-01

    This paper deals with a new macroscopic numerical modelling of the mechanical long-term behaviour of ANDRA's Underground Research Laboratory. The study focuses on the GMR gallery, oriented along the minor horizontal principal stress and located at the main level 490 m deep. The simulations are made using the finite element method (FEM).Convergence measurements in this gallery exhibit an important dis-symmetry between the vertical and horizontal directions, as well as a significant time effect in the vertical trend. In attempts to both understand the phenomena that lie beneath such dis-symmetry and reproduce the experimental data, a modification to Lemaitre's creep law has been proposed. The new viscoplastic law takes into account the following aspects: rock transverse isotropy, creep behaviour and rock expansion. The excavation history of the GMR gallery has also been considered in the numerical modelling. The numerical results are very satisfactory for the GMR drift. However, the mechanisms of anisotropic shear and expansion on which the new law is based do not lead to an accurate reproduction of the data measured in the galleries oriented in the perpendicular direction. Therefore, a thorough insight into the mechanical behaviour of the rock mass and into the proposed new law is needed before the latter can be applied to the Callovo-Oxfordian layer. (authors)

  6. Effect of Substrate Roughness on Adhesion and Structural Properties of Ti-Ni Shape Memory Alloy Thin Film.

    Science.gov (United States)

    Kim, Donghwan; Lee, Hyunsuk; Bae, Joohyeon; Jeong, Hyomin; Choi, Byeongkeun; Nam, Taehyun; Noh, Jungpil

    2018-09-01

    Ti-Ni shape memory alloy (SMA) thin films are very attractive material for industrial and medical applications such as micro-actuator, micro-sensors, and stents for blood vessels. An important property besides shape memory effect in the application of SMA thin films is the adhesion between the film and the substrate. When using thin films as micro-actuators or micro-sensors in MEMS, the film must be strongly adhered to the substrate. On the other hand, when using SMA thin films in medical devices such as stents, the deposited alloy thin film must be easily separable from the substrate for efficient processing. In this study, we investigated the effect of substrate roughness on the adhesion of Ti-Ni SMA thin films, as well as the structural properties and phase-transformation behavior of the fabricated films. Ti-Ni SMA thin films were deposited onto etched glass substrates with magnetron sputtering. Radio frequency plasma was used for etching the substrate. The adhesion properties were investigated through progressive scratch test. Structural properties of the films were determined via Feld emission scanning electron microscopy, X-ray diffraction measurements (XRD) and Energy-dispersive X-ray spectroscopy analysis. Phase transformation behaviors were observed with differential scanning calorimetry and low temperature-XRD. Ti-Ni SMA thin film deposited onto rough substrate provides higher adhesive strength than smooth substrate. However the roughness of the substrate has no influence on the growth and crystallization of the Ti-Ni SMA thin films.

  7. Visual events and the friendly eye: modes of educating vision in new educational settings in Danish art galleries

    Directory of Open Access Journals (Sweden)

    Helene Illeris

    2015-04-01

    Full Text Available New, experimental educational settings such as ‘art laboratories’, ‘digital workshops’ and ‘theme-based tours’ are important to the processes of change towards more inclusive practices, which have been initiated in many Danish art galleries. While traditional gallery education was constructed in order to stimulate the ‘disciplined eye’ or the ‘aesthetic eye’ of the visitors, this article aims to discuss the practices of looking encouraged by contemporary and experimental educational projects. The first part of the article develops a theoretical perspective on educational settings conceived as visual events, and it discusses how ‘the desiring eye’ of some constructivist approaches, along with traditional practices of looking, have contributed to the formation of the modern, autonomous individual. The second part of the article analyses two cases from Danish art galleries and, inspired by Mieke Bal, proposes the ‘friendly eye’ as a possible dialogical and collective practice of looking that can be stimulated in educational settings.

  8. The application of Tiny Triplet Finder (TTF) in BTeV pixel trigger

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jin-Yuan; Wang, M.; Gottschalk, E.; Shi, Z.; /Fermilab

    2006-03-01

    We describe a track segment recognition scheme called the Tiny Triplet Finder (TTF) that involves grouping of three hits satisfying a constraint such as forming of a straight line. The TTF performs this O(n{sup 3}) function in O(n) time, where n is number of hits in each detector plane. The word ''tiny'' reflects the fact that the FPGA resource usage is small. The number of logic elements needed for the TTF is O(Nlog(N)), where N is the number of bins in the coordinate considered, which for large N, is significantly smaller than O(N{sup 2}) needed for typical implementations of similar functions. The TTF is also suitable for software implementations as well as many other pattern recognition problems.

  9. Homogenization of stationary Navier–Stokes equations in domains with tiny holes

    Czech Academy of Sciences Publication Activity Database

    Feireisl, Eduard; Lu, Y.

    2015-01-01

    Roč. 17, č. 2 (2015), s. 381-392 ISSN 1422-6928 Keywords : compressible Navier - Stokes system * homogenization * tiny holes Subject RIV: BA - General Mathematics Impact factor: 1.023, year: 2015 http://link.springer.com/article/10.1007%2Fs00021-015-0200-2

  10. Cytocompatibility evaluation and surface characterization of TiNi deformed by high-pressure torsion

    Energy Technology Data Exchange (ETDEWEB)

    Awang Shri, Dayangku Noorfazidah, E-mail: AWANGSHRI.Dayangku@nims.go.jp [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Structural Materials Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan); Tsuchiya, Koichi [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Structural Materials Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan); Yamamoto, Akiko [Biomaterials Unit, International Center for Material Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044 (Japan)

    2014-10-01

    Effect of high-pressure torsion (HPT) deformation on biocompatibility and surface chemistry of TiNi was systematically investigated. Ti–50 mol% Ni was subjected to HPT straining for different numbers of turns, N = 0.25, 0.5, 1, 5 and 10 at a rotation speed of 1 rpm. X-ray photoelectron spectroscopy observations after 7 days of cell culture revealed the changes in the surface oxide composition, enrichment of Ti and detection of nitrogen derived from organic molecules in the culture medium. Plating efficiency of L929 cells was slightly increased by HPT deformation though no significant difference was observed. Albumin adsorption was higher in HPT-deformed samples, while vitronectin adsorption was peaked at N = 1. HPT deformation was also found to effectively suppress the Ni ion release from the TiNi samples into the cell culture medium even after the low degree of deformation at N = 0.25. - Highlights: • Nanostructured Ti–50 mol%Ni alloy was produced using high-pressure torsion. • HPT deformation improved L929 growth on TiNi samples. • Changes in surface chemistry were observed in HPT deformed samples. • Protein adsorption behavior was influenced by the surface chemistry. • Ni ion release was suppressed in HPT deformed samples.

  11. Continuum equivalent model for the fractured EDZ around underground galleries in clay-stone

    International Nuclear Information System (INIS)

    Pouya, A.; Bourgeois, E.; Larbi, B.; Poutrel, A.

    2010-01-01

    Document available in extended abstract form only. The Excavation Damaged Zone (EDZ) around the underground galleries excavated in clay-stone for the CMHM project, includes several zones showing different types of cracking and/or fracturing. In the vicinity of the wall, a fractured zone is observed that spreads out on a distance of about 1 m from the wall; at a larger distance from the wall one observes another zone with micro-cracks. The first zone, called 'fractured EDZ', includes different families of fractures with different geometries and origins. The main one consists of a family of shear fractures called 'chevron', that have approximately the shape of conical surfaces slightly flattened with respect to the horizontal plane. The 'chevrons' observed in the galleries at 490 m depth in LMSMH are regularly spaced of about 50 cm to 1 m along the gallery's axis, make an angle of about 45 deg. with this axis and extend to about 2 or 3 m beyond the wall depending of the size and orientation of the gallery. The fractures have a significant effect on the hydro-mechanical properties of the EDZ. The present work is focused on the effect of the 'chevron' fractures on the mechanical behaviour of the EDZ. Due to the large number of fractures, introducing them individually to the modelling leads to heavy and not easy to handle numerical models and to long calculations. One is led to find some Continuum Equivalent Material (CEM) for the EDZ including the fractures' effect. The EDZ is not very large compared to the fractures, so that it may not be fully justified to apply a homogenization approach; however, this is the approach we have used to define the behaviour of CEM. The geometry of the fractures is first simplified and assumed to correspond to conical surfaces with axial symmetry around the gallery's axis. The local behaviour of the CEM is deduced from the model of an infinite medium containing a family of planar

  12. Tiny Integrated Network Analyzer for Noninvasive Measurements of Electrically Small Antennas

    DEFF Research Database (Denmark)

    Buskgaard, Emil Feldborg; Krøyer, Ben; Tatomirescu, Alexandru

    2016-01-01

    the system. The tiny integrated network analyzer is a stand-alone Arduino-based measurement system that utilizes the transmit signal of the system under test as its reference. It features a power meter with triggering ability, on-board memory, universal serial bus, and easy extendibility with general...

  13. Technical feasibility of using gallery intakes for seawater RO facilities, northern Red Sea coast of Saudi Arabia: The King Abdullah Economic City site

    KAUST Repository

    Dehwah, Abdullah

    2013-02-13

    The Kingdom of Saudi Arabia is dependent on desalination of seawater to provide new water supplies for the future. Desalination is expensive and it is very important to reduce the cost and lower the energy consumption. Most seawater reverse osmosis facilities use open-ocean intakes, which require extensive pretreatment processes to remove particulate and biological materials that cause operating problems such as membrane fouling or shutdown during algal blooms. Subsurface systems, using the concept of riverbank filtration, can be used as intakes. These systems include wells of various designs and galleries that provide natural filtration and biological treatment to improve the quality of feed water before it enters the desalination plant. This reduces operating cost, lowers chemical and energy consumption, and reduces environmental impacts. Technical feasibility of gallery-type intakes, beach and seabed types, for use as intakes to seawater reverse osmosis (RO) facilities was evaluated along the northern Red Sea shoreline of Saudi Arabia. The geological characteristics of the offshore ocean bottom were found to be favorable for the development of seabed gallery systems, but the shoreline geology was not adequate for the development of beach gallery intakes. One of the potentially favorable sites for a seabed gallery system was located in the nearshore area at King Abdullah Economic City (KAEC). Detailed investigation of the site hydrology (tides and wave action), sediment grain size characteristics, and sediment hydraulic conductivity, and access for construction were assessed. It was determined that seabed gallery development is favorable at the site. Based on the seawater that has a salinity of about 41,000 mg/L and a conversion rate of 40%, a conservatively designed gallery cell with dimensions of 100 by 50 m would produce about 25,000 m3/day of filtered seawater and seven cells (6 primary and 1 standby) could support a 60,000 m3/day (permeate) seawater RO plant

  14. Continuous-Wave Operation of a Frequency-Tunable 460-GHz Second-Harmonic Gyrotron for Enhanced Nuclear Magnetic Resonance

    Science.gov (United States)

    Torrezan, Antonio C.; Han, Seong-Tae; Mastovsky, Ivan; Shapiro, Michael A.; Sirigiri, Jagadishwar R.; Temkin, Richard J.; Griffin, Robert G.; Barnes, Alexander B.

    2012-01-01

    The design, operation, and characterization of a continuous-wave (CW) tunable second-harmonic 460-GHz gyrotron are reported. The gyrotron is intended to be used as a submillimeter-wave source for 700-MHz nuclear magnetic resonance experiments with sensitivity enhanced by dynamic nuclear polarization. The gyrotron operates in the whispering-gallery mode TE11,2 and has generated 16 W of output power with a 13-kV 100-mA electron beam. The start oscillation current measured over a range of magnetic field values is in good agreement with theoretical start currents obtained from linear theory for successive high-order axial modes TE11,2,q. The minimum start current is 27 mA. Power and frequency tuning measurements as a function of the electron cyclotron frequency have also been carried out. A smooth frequency tuning range of 1 GHz was obtained for the operating second-harmonic mode either by magnetic field tuning or beam voltage tuning. Long-term CW operation was evaluated during an uninterrupted period of 48 h, where the gyrotron output power and frequency were kept stable to within ±0.7% and ±6 ppm, respectively, by a computerized control system. Proper operation of an internal quasi-optical mode converter implemented to transform the operating whispering-gallery mode to a Gaussian-like beam was also verified. Based on the images of the gyrotron output beam taken with a pyroelectric camera, the Gaussian-like mode content of the output beam was computed to be 92% with an ellipticity of 12%. PMID:23761938

  15. Adiabatic tapered optical fiber fabrication for exciting whispering gallery modes in microcavities

    Science.gov (United States)

    Chenari, Z.; Latifi, H.; Hashemi, R. S.; Doroudmand, F.

    2014-05-01

    This article demonstrates an investigation and analysis of a tapered fiber fabrication using an etchant droplet method. To achieve precise control on process, a two-step etching method is proposed (using 48% concentration of HF acid and Buffered HF) which results in low-loss adiabatic tapered fiber. A spectrum analysis monitoring in addition to a microscopy system was used to verify the etching progress. Tapers with losses less than 0.4 dB in air and 4.5 dB in water are demonstrated. A biconical fiber taper fabricated using this method was used to excite the WGMs on a microsphere surface in aquatic environment.

  16. Lifelong Learning for People Aged 64+ within the Contemporary Art Gallery Context

    Science.gov (United States)

    Goulding, Anna

    2012-01-01

    This paper reports the initial findings from Contemporary Visual Art and Identity Construction--Wellbeing Amongst Older People: a two-year research project that aims to understand how the lives of older people can be improved by examining their use of contemporary visual art in the art gallery and museum. It will focus on data relating to lifelong…

  17. Artistic Sensibility in the Studio and Gallery Model: Revisiting Process and Product

    Science.gov (United States)

    Thompson, Geoffrey

    2009-01-01

    This paper examines the cultivation of artistic sensibility and its impact on the art therapy process and product in a community mental health center. Artistic sensibility embodies the sense of self as an artist through the integration of artistic and aesthetic attributes of self and other. The formation of a gallery to exhibit patient art was…

  18. Small scale optics

    CERN Document Server

    Yupapin, Preecha

    2013-01-01

    The behavior of light in small scale optics or nano/micro optical devices has shown promising results, which can be used for basic and applied research, especially in nanoelectronics. Small Scale Optics presents the use of optical nonlinear behaviors for spins, antennae, and whispering gallery modes within micro/nano devices and circuits, which can be used in many applications. This book proposes a new design for a small scale optical device-a microring resonator device. Most chapters are based on the proposed device, which uses a configuration know as a PANDA ring resonator. Analytical and nu

  19. Quantum-dot micropillars for parametric THz emission

    DEFF Research Database (Denmark)

    Mariani, S.; Andronico, A.; Favero, I.

    2013-01-01

    We report on the design, fabrication and optical investigation of AlGaAs microcavities for THz Difference Frequency Generation (DFG) between Whispering Gallery Modes (WGMs), where the pump and DFG wavelengths (λ ≈ 1.3 μm and λ ≈ 75-150 μm, respectively) lie on opposite sides of the Restrahlen band....... For the pump modes, we demonstrate CW lasing of quantum-dot layers under electrical injection at room temperature. We control the number of lasing WGMs via vertical notches on the pillars sidewalls, providing a selection mechanism for funneling the power only to the modes contributing to DFG. In parallel...

  20. Tailoring of the free spectral range and geometrical cavity dispersion of a microsphere by a coating layer.

    Science.gov (United States)

    Ristić, Davor; Mazzola, Maurizio; Chiappini, Andrea; Rasoloniaina, Alphonse; Féron, Patrice; Ramponi, Roberta; Righini, Giancarlo C; Cibiel, Gilles; Ivanda, Mile; Ferrari, Maurizio

    2014-09-01

    The modal dispersion of a whispering gallery mode (WGM) resonator is a very important parameter for use in all nonlinear optics applications. In order to tailor the WGM modal dispersion of a microsphere, we have coated a silica microsphere with a high-refractive-index coating in order to study its effect on the WGM modal dispersion. We used Er(3+) ions as a probe for a modal dispersion assessment. We found that, by varying the coating thickness, the geometrical cavity dispersion can be used to shift overall modal dispersion in a very wide range in both the normal and anomalous dispersion regime.

  1. Experiences from a Real-Time Mobile Collaborative Writing System in an Art Gallery

    DEFF Research Database (Denmark)

    Korn, Matthias; Polli, Anna Maria; Klokmose, Clemens Nylandsted

    as interfaces to the shared physical space. With a collocated collaborative writing system in the semi-public space of a gallery, we encourage local art discussions and provide a platform for the public to actively participate in interpretations of individual artworks. In this paper, we focus on the experiences...

  2. The evaluation of radon concentration and working levels using SSNTD in the U-exploration galleries in the eastern desert, Egypt

    International Nuclear Information System (INIS)

    Abdel-hafez, A.I.; Eissa, H.M.; Abdel-Monem, A.A.; Abdel-Razek, Y.A.; El-Naggar, A.M.; El-fiki, S.A.

    1996-01-01

    Radon gas concentrations and the working levels (radon daughters concentrations) were measured using solid state nuclear track detectors (SSNTD) namely Cr-39, Mk, Lr 115 and CN 85, in three U-exploration galleries at Qattar-1, El Missikat, and El-Erediya areas, eastern desert, Egypt. In each U-exploration gallery 10 monitoring stations were chosen for measurements. The locations covered the differing intensities of the U-mineralization as well as ventilation conditions. Two sets of measurements were for the time intervals and 50 days). Calibration experiments on the SSNTD were performed using 238 Pu source (6.06/MeV), to find the optimum conditions for etching the detectors. The ranges of alpha track densities (t/mm 2 day) measured for Qattar-1 gallery are 23.7-46.6 (CR-39), 13.4-30.9 (MK), 11.1-22.9 (CN-85) and 8.8-15.4 (LR-115) for 27 day monitoring, whereas the ranges for the 50 days experiment are 8.8-25.8 (CR-39), 8.3-15.4 (MK) and 3.9-8.2 (LR-115). In el Missikat gallery, the alpha track densities ranges are 17.1-128.8 (CR-39), 11.4-73.1 (MK), 8.0-74.4 (CN.85) and 5.7-37.8 (LR-115) for the 27 day interval, whereas the ranges are (CR-39), 6.3-38.0 (MK) and 3.4-21.0 (LR-115) for the 50 days experiments. Alpha tracks densities for El-Erediya gallery ranges are 14.1-39.9 (CR-39), 8.9-20.0 (MK), 7.9-23.1 (CN-85), and 2.7-17.6 (LR-115) for the 27 days experiment. whereas the ranges are 8.5-22.7 (CR-39), 6.4-13.4 (MK), and 2.4-9.3 (LR-115)for the 50 days experiment. Working level measurements are compared with 1 W L equivalent to 16.28 tracks/ mm 2 day. Evaluation of the measurements at each monitoring station is discussed in terms of U-concentration and ventilation conditions. Also, the efficiency of the different SSNTD are discussed as well as the optimum time of monitoring at each U-exploration gallery. 4 figs., 5 tabs

  3. The evaluation of radon concentration and working levels using SSNTD in the U-exploration galleries in the eastern desert, Egypt

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-hafez, A I; Eissa, H M [National Institute of Measurement and Standards, Technology, Cairo (Egypt); Abdel-Monem, A A; Abdel-Razek, Y A; El-Naggar, A M [Nuclear Materials Authority, Cairo (Egypt); El-fiki, S A [Physicsics Dept., Faculty of Sciences, Ain Shams University. Cairo (Egypt)

    1997-12-31

    Radon gas concentrations and the working levels (radon daughters concentrations) were measured using solid state nuclear track detectors (SSNTD) namely Cr-39, Mk, Lr 115 and CN 85, in three U-exploration galleries at Qattar-1, El Missikat, and El-Erediya areas, eastern desert, Egypt. In each U-exploration gallery 10 monitoring stations were chosen for measurements. The locations covered the differing intensities of the U-mineralization as well as ventilation conditions. Two sets of measurements were for the time intervals and (50 days). Calibration experiments on the SSNTD were performed using {sup 238} Pu source (6.06/MeV), to find the optimum conditions for etching the detectors. The ranges of alpha track densities (t/mm{sup 2} day) measured for Qattar-1 gallery are 23.7-46.6 (CR-39), 13.4-30.9 (MK), 11.1-22.9 (CN-85) and 8.8-15.4 (LR-115) for 27 day monitoring, whereas the ranges for the 50 days experiment are 8.8-25.8 (CR-39), 8.3-15.4 (MK) and 3.9-8.2 (LR-115). In el Missikat gallery, the alpha track densities ranges are 17.1-128.8 (CR-39), 11.4-73.1 (MK), 8.0-74.4 (CN.85) and 5.7-37.8 (LR-115) for the 27 day interval, whereas the ranges are (CR-39), 6.3-38.0 (MK) and 3.4-21.0 (LR-115) for the 50 days experiments. Alpha tracks densities for El-Erediya gallery ranges are 14.1-39.9 (CR-39), 8.9-20.0 (MK), 7.9-23.1 (CN-85), and 2.7-17.6 (LR-115) for the 27 days experiment. whereas the ranges are 8.5-22.7 (CR-39), 6.4-13.4 (MK), and 2.4-9.3 (LR-115)for the 50 days experiment. Working level measurements are compared with 1 W L equivalent to 16.28 tracks/ mm{sup 2} day. Evaluation of the measurements at each monitoring station is discussed in terms of U-concentration and ventilation conditions. Also, the efficiency of the different SSNTD are discussed as well as the optimum time of monitoring at each U-exploration gallery. 4 figs., 5 tabs.

  4. The effect of the electronic structure, phase transition, and localized dynamics of atoms in the formation of tiny particles of gold

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Mubarak, E-mail: mubarak74@comsats.edu.pk, E-mail: mubarak74@mail.com [COMSATS Institute of Information Technology, Department of Physics (Pakistan); Lin, I-Nan [Tamkang University, Department of Physics (China)

    2017-01-15

    In addition to self-governing properties, tiny-sized particles of metallic colloids are the building blocks of large-sized particles; thus, their study has been the subject of a large number of publications. In the present work, it has been discussed that geometry structure of tiny particle made through atom-to-atom amalgamation depends on attained dynamics of gold atoms along with protruded orientations. The localized process conditions direct two-dimensional structure of a tiny particle at atomically flat air-solution interface while heating locally dynamically approached atoms, thus, negate the role of van der Waals interactions. At electronphoton-solution interface, impinging electrons stretch or deform atoms of tiny particles depending on the mechanism of impingement. In addition, to strike regular grid of electrons ejected on split of atoms not executing excitations and de-excitations of their electrons, atoms of tiny particles also deform or stretch while occupying various sites depending on the process of synergy. Under suitable impinging electron streams, those tiny particles in monolayer two-dimensional structure electron states of their atoms are diffused in the direction of transferred energy, thus, coincide to the next adjacent atoms in each one-dimensional array dealing the same sort of behavior. Instantaneously, photons of adequate energy propagate on the surfaces of such electronic structures and modify those into smooth elements, thus, disregard the phenomenon of localized surface plasmons. This study highlights the fundamental process of formation of tiny particles where the role of localized dynamics of atoms and their electronic structure along with interaction to light are discussed. Such a tool of processing materials, in nonequilibrium pulse-based process, opens a number of possibilities to develop engineered materials with specific chemical, optical, and electronic properties.

  5. Fra Bartolomeo della Porta detto Fra Bartolomeo, Adorazione del Bambino, National Gallery, London

    DEFF Research Database (Denmark)

    Fischer, Chris

    2014-01-01

    En artikel om et maleri af Fra Bartolomeo i National Gallery i London udlånt til en udstilling i Museo Tosio Martinengo I Brescia i forbindelse med opdagelsen af et fuldstændigt overensstemmende maleri i dette museums magasiner. Hypotesen var at Bresciabilledet var et værkstedsarbejde lavet på ba...

  6. Origins of tiny neutrino mass and large flavor mixings

    International Nuclear Information System (INIS)

    Haba, Naoyuki

    2015-01-01

    Active neutrino masses are extremely smaller than those of other quarks and leptons, and there are large flavor mixings in the lepton sector, contrary to the quark sector. They are great mysteries in the standard model, but also excellent hints of new physics beyond the standard model. Thus, questions 'What is an origin of tiny neutrino mass?' and 'What is an origin of large lepton flavor mixings?' are very important. In this paper, we overview various attempts to solve these big questions. (author)

  7. The kinetics of Cr layer coated on TiNi films for hydrogen absorption

    Indian Academy of Sciences (India)

    Abstract. The effect of hydrogen absorption on electrical resistance with temperature ... pressure by thermal evaporation on the glass substrate at room temperature. ... and charging rate becomes faster in comparison to FeTi and TiNi thin films.

  8. Long the fixation of physicists worldwide, a tiny particle is found

    CERN Multimedia

    2006-01-01

    "After decades of intensive effort by both experimental and theoretical physicists worldwide, a tiny particle with no charge, a very low mass and a lifetime much shorter than a nanosecond, dubbed the "axion", has now been detected by the University at Buffalo physicist who first suggested its existence in a little-read paper as early as 194." (2 pages)

  9. Electrical resistivity tomography survey for delineating uncharted mine galleries in West Bengal, India

    International Nuclear Information System (INIS)

    Maillol, J.M.; Sen, N.

    1999-01-01

    The history of subsidence, fires, flooding and other kinds of environmental hazards related to shallow coal workings in India goes back to colonial times some 300 years ago. As coal production accelerated in modern times, so did the environmental and socio-economic drawbacks related to exploitation. In the mid-1980s, a hydropneumatic sand-stowing method was developed to fill in abandoned galleries but their exact location had to be known. Unfortunately, most of these old workings are uncharted and consequently large tracts of land cannot be stabilized. A research program making use of integrated surface, borehole and cross-hole geophysical methods was undertaken over a five-year span to try to solve this problem. Surface geophysical methods, being cheaper and faster than their cross- and downhole counterparts, were used to cover larger areas on an exploratory basis, while cross-hole methods were employed to locate more accurately one or a network of galleries to be perforated by drillhole(s) and used as a conduit for sand stowing. The authors report the results of one of the cross-hole geophysical methods: electrical resistivity tomography (ERT). A pole-dipole configuration is used and both cross-hole and surface-borehole methodologies are tested. Forward modelling and inversion of synthetic data making use of downhole and surface physical and geometrical parameters are presented first. This phase is followed by the inversion of real data. It is concluded that ERT is not applicable for the detection of dry voids, but is effective in a waterlogged environment which is estimated to represent 85--90% of the cases. In waterlogged galleries, ERT is applicable in both cross-hole and surface-downhole modes, the latter allowing a larger surface coverage at low cost. ERT is thus a reliable geophysical tool to image water-filled voids and an adequate technique to address environmental and geotechnical problems

  10. TinyONet: A Cache-Based Sensor Network Bridge Enabling Sensing Data Reusability and Customized Wireless Sensor Network Services

    Science.gov (United States)

    Jung, Eui-Hyun; Park, Yong-Jin

    2008-01-01

    In recent years, a few protocol bridge research projects have been announced to enable a seamless integration of Wireless Sensor Networks (WSNs) with the TCP/IP network. These studies have ensured the transparent end-to-end communication between two network sides in the node-centric manner. Researchers expect this integration will trigger the development of various application domains. However, prior research projects have not fully explored some essential features for WSNs, especially the reusability of sensing data and the data-centric communication. To resolve these issues, we suggested a new protocol bridge system named TinyONet. In TinyONet, virtual sensors play roles as virtual counterparts of physical sensors and they dynamically group to make a functional entity, Slice. Instead of direct interaction with individual physical sensors, each sensor application uses its own WSN service provided by Slices. If a new kind of service is required in TinyONet, the corresponding function can be dynamically added at runtime. Beside the data-centric communication, it also supports the node-centric communication and the synchronous access. In order to show the effectiveness of the system, we implemented TinyONet on an embedded Linux machine and evaluated it with several experimental scenarios. PMID:27873968

  11. The Spiral Gallery: Non-Market Creativity and Belonging in an Australian Country Town

    Science.gov (United States)

    Waitt, Gordon; Gibson, Chris

    2013-01-01

    This paper seeks to explore creative practice in an Australian country town, and in so doing, to unsettle market-orientated interpretations of creativity that privilege the urban. Instead of focusing on creative practice as a means to develop industries, we focus on how creativity is a means to establish a cooperative gallery space that helps to…

  12. Swimming of a Tiny Subtropical Sea Butterfly with Coiled Shell

    Science.gov (United States)

    Murphy, David; Karakas, Ferhat; Maas, Amy

    2017-11-01

    Sea butterflies, also known as pteropods, include a variety of small, zooplanktonic marine snails. Thecosomatous pteropods possess a shell and swim at low Reynolds numbers by beating their wing-like parapodia in a manner reminiscent of insect flight. In fact, previous studies of the pteropod Limacina helicina have shown that pteropod swimming hydrodynamics and tiny insect flight aerodynamics are dynamically similar. Studies of L. helicina swimming have been performed in polar (0 degrees C) and temperate conditions (12 degrees C). Here we present measurements of the swimming of Heliconoides inflatus, a smaller yet morphologically similar pteropod that lives in warm Bermuda seawater (21 degrees C) with a viscosity almost half that of the polar seawater. The collected H. inflatus have shell sizes less than 1.5 mm in diameter, beat their wings at frequencies up to 11 Hz, and swim upwards in sawtooth trajectories at speeds up to approximately 25 mm/s. Using three-dimensional wing and body kinematics collected with two orthogonal high speed cameras and time-resolved, 2D flow measurements collected with a micro-PIV system, we compare the effects of smaller body size and lower water viscosity on the flow physics underlying flapping-based swimming by pteropods and flight by tiny insects.

  13. Heterogeneous tiny energy: An appealing opportunity to power wireless sensor motes in a corrosive environment

    International Nuclear Information System (INIS)

    Qiao, Guofu; Sun, Guodong; Li, Hui; Ou, Jinping

    2014-01-01

    Highlights: • Ultra-low ambient energy was scavenged to power the first of its kind wireless corrosion sensors. • Three feasible tiny-energy sources were exploited for long-term corrosion monitoring. • Automatic recharging control of heterogeneous tiny energy was proposed for human-free monitoring. • Corrosion itself was applied as an energy source to power the wireless corrosion-monitoring motes. - Abstract: Reinforcing steel corrosion is a significant factor leading to the durability deterioration of reinforced concrete (RC) structures. The on-line monitoring of the corrosion of RC structures in a long-term, human-free manner is not only valuable in industry, but also a significant challenge in academia. This paper presents the first of its kind corrosion-monitoring approach that only exploits three heterogeneous tiny energy sources to power commercial-off-the-shelf wireless sensor motes such that the corrosion-related data are automatically and autonomously captured and sent to users via wireless channels. We first investigated the availability of these three tiny energy sources: corrosion energy, a cement battery, and a weak solar energy. In particular, the two former energy sources inherently exist in RC structures and can be generated continually in the service-life of RC structures, which beneficial for the prospects of long-term corrosion monitoring. We then proposed a proof-of-concept prototype, which consisted of a Telosb wireless sensor mote and an energy harvester in order to evaluate the feasibility and effectiveness of the ultralow-power ambient energy as a type of power supply in corrosion monitoring applications. The critical metrics for the holographic monitoring of RC structures, including electrochemical noise, humidity and temperature, were successfully acquired and analysed using a post-processing program. This paper describes a unique and novel approach towards the realisation of smart structural monitoring and control system in the

  14. Nanocellulose, a tiny fiber with huge applications.

    Science.gov (United States)

    Abitbol, Tiffany; Rivkin, Amit; Cao, Yifeng; Nevo, Yuval; Abraham, Eldho; Ben-Shalom, Tal; Lapidot, Shaul; Shoseyov, Oded

    2016-06-01

    Nanocellulose is of increasing interest for a range of applications relevant to the fields of material science and biomedical engineering due to its renewable nature, anisotropic shape, excellent mechanical properties, good biocompatibility, tailorable surface chemistry, and interesting optical properties. We discuss the main areas of nanocellulose research: photonics, films and foams, surface modifications, nanocomposites, and medical devices. These tiny nanocellulose fibers have huge potential in many applications, from flexible optoelectronics to scaffolds for tissue regeneration. We hope to impart the readers with some of the excitement that currently surrounds nanocellulose research, which arises from the green nature of the particles, their fascinating physical and chemical properties, and the diversity of applications that can be impacted by this material. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Rewriting Revolutionary Myths: Photography in Castro’s Cuba and Tania Bruguera’s Tatlin’s Whisper#6

    Directory of Open Access Journals (Sweden)

    Louisa Söllner

    2014-11-01

    Full Text Available Photography was a key medium for creating, spreading, and cementing myths about the Cuban Revolution and its leaders. In the first part of this essay, I’ll explore several iconic images as well as responses to these pictures, all parts of a Cuban “cross-national memory discourse” (cf. Quiroga, 2005. Walter Benjamin’s media philosophy can help in developing insights about the functioning of these photographs. In the second part of the paper, I turn to Tania Bruguera’s piece Tatlin’s Whisper#6 (staged at the 10th Havana Biennial in 2009, which radically rewrites the poetics of the images and aspires to create a sense of participation and direct involvement.

  16. Kulturní hodnoty tzv. Mariánského trojúhelníku - Sloup, Vranov, Křtiny

    OpenAIRE

    Bezděková, Veronika

    2009-01-01

    In the Moravian Karst there are three big churches consecrated to The Virgin Mary. These are visited by many pilgrims and have their own calendar of pilgrimages. They are Vranov, Křtiny and Sloup. Churches in these towns are consecrated to The Virgin Mary: Vranov commemorates the birth of The Virgin Mary, Křtiny commemorates the name of The Virgin Mary and Sloup commemorates the sufferings of The Virgin Mary. So we talk about the triangle of The Virgin Mary. This term is the main point of my ...

  17. High temperature annealing effect on structural and magnetic properties of Ti/Ni multilayers

    International Nuclear Information System (INIS)

    Bhatt, Pramod; Ganeshan, V.; Reddy, V.R.; Chaudhari, S.M.

    2006-01-01

    High temperature annealing effect on structural and magnetic properties of Ti/Ni multilayer (ML) up to 600 deg. C have been studied and reported in this paper. Ti/Ni multilayer samples having constant layer thicknesses of 50 A each are deposited on float glass and Si(1 1 1) substrates using electron-beam evaporation technique under ultra-high vacuum (UHV) conditions at room temperatures. The micro-structural parameters and their evolution with temperature for as-deposited as well as annealed multilayer samples up to 600 deg. C in a step of 100 deg. C for 1 h are determined by using X-ray diffraction (XRD) and grazing incidence X-ray reflectivity techniques. The X-ray diffraction pattern recorded at 300 deg. C annealed multilayer sample shows interesting structural transformation (from crystalline to amorphous) because of the solid-state reaction (SSR) and subsequent re-crystallization at higher temperatures of annealing, particularly at ≥400 deg. C due to the formation of TiNi 3 and Ti 2 Ni alloy phases. Sample quality and surface morphology are examined by using atomic force microscopy (AFM) technique for both as-deposited as well as annealed multilayer samples. In addition to this, a temperature dependent dc resistivity measurement is also used to study the structural transformation and subsequent alloy phase formation due to annealing treatment. The corresponding magnetization behavior of multilayer samples after each stage of annealing has been investigated by using Magneto-Optical Kerr Effect (MOKE) technique and results are interpreted in terms of observed micro-structural changes

  18. Feasibility of Gallery Intake Systems for Seawater Reverse Osmosis Facilities along the Northern Red Sea Coast of Saudi Arabia

    KAUST Repository

    Dehwah, Abdullah

    2012-03-01

    The Kingdom of Saudi Arabia is dependent on desalination of seawater to provide new water supplies for the future. Desalination is expensive and it is very important to reduce the cost and lower the energy consumption. Most seawater reverse osmosis facilities use open-ocean intakes, which require extensive pre-treatment processes to remove particulate and biological materials that cause operating problems. An alternative intake is the subsurface system which utilizes the concept of riverbank filtration using wells or galleries and provides natural filtration to improve the quality of feedwater before it enters the desalination plant. This reduces operating cost and lowers energy consumption. Research was focused on evaluating gallery-type intakes (beach and seabed galleries) that could be used along the Northern Red Sea shoreline to provide a better quality feedwater for desalination. The geological characteristics of the visited sites were favorable for the development of seabed filter systems (offshore), but not for beach gallery intakes. The low wave energy along the shoreline and the presence of mud or rocky coasts made beach galleries infeasible. One of the potentially favorable sites for a seabed filter was located in the nearshore area at King Abdullah Economic City (KAEC). This site has a predominantly sandy offshore bottom with shallow water depths, and a low tide range. In addition, the bottom is always covered with water and contains soft limestone unit below the sand mantle that could be easy excavated to facilitate the construction of a seabed filter. About 50 sediment samples were collected from the site and laboratory measurements were performed on them. Grain size distribution, porosity and hydraulic conductivity measurements were performed on the sediment samples. In addition, six statistical methods were used to estimate the hydraulic conductivity values. Based on results of lab measurements, field observations, tide ranges and sediment types, it

  19. Stability and time-domain analysis of the dispersive tristability in microresonators under modal coupling

    Science.gov (United States)

    Dumeige, Yannick; Féron, Patrice

    2011-10-01

    Coupled nonlinear resonators have potential applications for the integration of multistable photonic devices. The dynamic properties of two coupled-mode nonlinear microcavities made of Kerr material are studied by linear stability analysis. Using a suitable combination of the modal coupling rate and the frequency detuning, it is possible to obtain configurations where a hysteresis loop is included inside other bistable cycles. We show that a single resonator with two modes both linearly and nonlinearly coupled via the cross-Kerr effect can have a multistable behavior. This could be implemented in semiconductor nonlinear whispering-gallery-mode microresonators under modal coupling for all optical signal processing or ternary optical logic applications.

  20. Stability and time-domain analysis of the dispersive tristability in microresonators under modal coupling

    International Nuclear Information System (INIS)

    Dumeige, Yannick; Feron, Patrice

    2011-01-01

    Coupled nonlinear resonators have potential applications for the integration of multistable photonic devices. The dynamic properties of two coupled-mode nonlinear microcavities made of Kerr material are studied by linear stability analysis. Using a suitable combination of the modal coupling rate and the frequency detuning, it is possible to obtain configurations where a hysteresis loop is included inside other bistable cycles. We show that a single resonator with two modes both linearly and nonlinearly coupled via the cross-Kerr effect can have a multistable behavior. This could be implemented in semiconductor nonlinear whispering-gallery-mode microresonators under modal coupling for all optical signal processing or ternary optical logic applications.

  1. Efficient analysis of mode profiles in elliptical microcavity using dynamic-thermal electron-quantum medium FDTD method.

    Science.gov (United States)

    Khoo, E H; Ahmed, I; Goh, R S M; Lee, K H; Hung, T G G; Li, E P

    2013-03-11

    The dynamic-thermal electron-quantum medium finite-difference time-domain (DTEQM-FDTD) method is used for efficient analysis of mode profile in elliptical microcavity. The resonance peak of the elliptical microcavity is studied by varying the length ratio. It is observed that at some length ratios, cavity mode is excited instead of whispering gallery mode. This depicts that mode profiles are length ratio dependent. Through the implementation of the DTEQM-FDTD on graphic processing unit (GPU), the simulation time is reduced by 300 times as compared to the CPU. This leads to an efficient optimization approach to design microcavity lasers for wide range of applications in photonic integrated circuits.

  2. Surface wave resonance and chirality in a tubular cavity with metasurface design

    Science.gov (United States)

    Qin, Yuzhou; Fang, Yangfu; Wang, Lu; Tang, Shiwei; Sun, Shulin; Liu, Zhaowei; Mei, Yongfeng

    2018-06-01

    Optical microcavities with whispering-gallery modes (WGMs) have been indispensable in both photonic researches and applications. Besides, metasurfaces, have attracted much attention recently due to their strong abilities to manipulate electromagnetic waves. Here, combining these two optical elements together, we show a tubular cavity can convert input propagating cylindrical waves into directed localized surface waves (SWs), enabling the circulating like WGMs along the wall surface of the designed tubular cavity. Finite element method (FEM) simulations demonstrate that such near-field WGM shows both large chirality and high local field. This work may stimulate interesting potential applications in e.g. directional emission, sensing, and lasing.

  3. Optofluidics Refractometers

    Directory of Open Access Journals (Sweden)

    Cheng Li

    2018-03-01

    Full Text Available Refractometry is a classic analytical method in analytical chemistry and biosensing. By integrating advanced micro- and nano-optical systems with well-developed microfluidics technology, optofluidics are shown to be a powerful, smart and universal platform for refractive index sensing applications. This paper reviews recent work on optofluidic refractometers based on different sensing mechanisms and structures (e.g., photonic crystal/photonic crystal fibers, waveguides, whisper gallery modes and surface plasmon resonance, and traces the performance enhancement due to the synergistic integration of optics and microfluidics. A brief discussion of future trends in optofluidic refractometers, namely volume sensing and resolution enhancement, are also offered.

  4. Silicon Microspheres Photonics

    International Nuclear Information System (INIS)

    Serpenguzel, A.

    2008-01-01

    Electrophotonic integrated circuits (EPICs), or alternatively, optoelectronic integrated circuit (OEICs) are the natural evolution of the microelectronic integrated circuit (IC) with the addition of photonic capabilities. Traditionally, the IC industry has been based on group IV silicon, whereas the photonics industry on group III-V semiconductors. However, silicon based photonic microdevices have been making strands in siliconizing photonics. Silicon microspheres with their high quality factor whispering gallery modes (WGMs), are ideal candidates for wavelength division multiplexing (WDM) applications in the standard near-infrared communication bands. In this work, we will discuss the possibility of using silicon microspheres for photonics applications in the near-infrared

  5. Evidence of dilute ferromagnetism in rare-earth doped yttrium aluminium garnet

    Energy Technology Data Exchange (ETDEWEB)

    Farr, Warrick G.; Goryachev, Maxim; Le Floch, Jean-Michel; Tobar, Michael E. [ARC Centre of Excellence for Engineered Quantum Systems, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009 (Australia); Bushev, Pavel [Experimentalphysik, Universität des Saarlandes, D-66123 Saarbrücken (Germany)

    2015-09-21

    This work demonstrates strong coupling regime between an erbium ion spin ensemble and microwave hybrid cavity-whispering gallery modes in a yttrium aluminium garnet dielectric crystal. Coupling strengths of 220 MHz and mode quality factors in excess of 10{sup 6} are demonstrated. Moreover, the magnetic response of high-Q modes demonstrates behaviour which is unusual for paramagnetic systems. This behaviour includes hysteresis and memory effects. Such qualitative change of the system's magnetic field response is interpreted as a phase transition of rare earth ion impurities. This phenomenon is similar to the phenomenon of dilute ferromagnetism in semiconductors. The clear temperature dependence of the phenomenon is demonstrated.

  6. Tiny intracranial aneurysms: Endovascular treatment by coil embolisation or sole stent deployment

    International Nuclear Information System (INIS)

    Lu Jun; Liu Jiachun; Wang Lijun; Qi Peng; Wang Daming

    2012-01-01

    Purpose: Tiny intracranial aneurysms pose a significant therapeutic challenge for interventional neuroradiologists. The authors report their preliminary results of endovascular treatment of these aneurysms. Methods: Between January 2002 and December 2009, 52 tiny intracranial aneurysms (defined as ≤3 mm in maximum diameter) in 46 patients (22 men; mean age, 57.9 years) were treated by endosaccular coil embolisation or sole stent deployment in the parent artery. Of 52 aneurysms, 29 had ruptured and 23 remained unruptured. The initial angiographic results, procedural complications, and clinical outcomes were assessed at discharge. Imaging follow-up was performed with cerebral angiography. Results: One aneurysm coiling procedure failed because of unsuccessful micro-catheterization. Forty-three aneurysms were successfully coil embolized, of which complete occlusion was obtained in 14, subtotal occlusion in 18 and incomplete occlusion in 11. The other 8 aneurysms were treated by sole stent deployment in the parent artery. Procedural complications (2 intraprocedural ruptures and 3 thromboembolic events) occurred in 5 (9.6%) of 52 aneurysms, resulting in permanent morbidity in only 1 (2.2%, 1/46) patient. No rebleeding occurred during clinical follow-up (mean duration, 46.7 months). Of the 16 coiled aneurysms that receiving repetitive angiography, 6 initially completely and 3 subtotally occluded aneurysms remained unchanged, 4 initially subtotally and 3 incompletely occluded aneurysms progressed to total occlusion. Five sole stent deployed aneurysms received angiographic follow-up (mean duration, 10.0 months), of which 3 remained unchanged, 1 became smaller and 1 progressed to total occlusion. Conclusion: Endovascular treatment of tiny intracranial aneurysms is technical feasible and relatively safe. Coil embolisation seems to be effective in preventing early recanalisation, whereas sole stenting technique needs further investigation to determine its effectiveness.

  7. Effects of Surface Dipole Lengths on Evaporation of Tiny Water Aggregation

    International Nuclear Information System (INIS)

    Wang Shen; Wan Rongzheng; Fang Haiping; Tu Yusong

    2013-01-01

    Using molecular dynamics simulation, we compared evaporation behavior of a tiny amount of water molecules adsorbed on solid surfaces with different dipole lengths, including surface dipole lengths of 1 fold, 2 folds, 4 folds, 6 folds and 8 folds of 0.14 nm and different charges from 0.1e to 0.9e. Surfaces with short dipole lengths (1-fold system) can always maintain hydrophobic character and the evaporation speeds are not influenced, whether the surface charges are enhanced or weakened; but when surface dipole lengths get to 8 folds, surfaces become more hydrophilic as the surface charge increases, and the evaporation speeds increase gradually and monotonically. By tuning dipole lengths from 1-fold to 8-fold systems, we confirmed non-monotonic variation of the evaporation flux (first increases, then decreases) in 4 fold system with charges (0.1e–0.7e), reported in our previous paper [S. Wang, et al., J. Phys. Chem. B 116 (2012) 13863], and also show the process from the enhancement of this unexpected non-monotonic variation to its vanishment with surface dipole lengths increasing. Herein, we demonstrated two key factors to influence the evaporation flux of a tiny amount of water molecules adsorbed on solid surfaces: the exposed surficial area of water aggregation from where the water molecules can evaporate directly and the attraction potential from the substrate hindering the evaporation. In addition, more interestingly, we showed extra steric effect of surface dipoles on further increase of evaporation flux for 2-folds, 4-folds, 6-folds and 8-folds systems with charges around larger than 0.7e. (The steric effect is first reported by parts of our authors [C. Wang, et al., Sci. Rep. 2 (2012) 358]). This study presents a complete physical picture of the influence of surface dipole lengths on the evaporation behavior of the adsorbed tiny amount of water. (condensed matter: structural, mechanical, and thermal properties)

  8. Thermal simulation of drift emplacement. Geotechnical and geophysical investigations in and around backfilled galleries

    International Nuclear Information System (INIS)

    Schneefub, J.U.; Gommlich, G.E.

    1988-01-01

    The concept for the direct disposal of spent fuel in rock salt foresees the emplacement of large waste canisters on the floor of a disposal gallery. Subsequent to emplacement the drift is backfilled with salt grit. In a demonstration test six cylindrical containments are to be emplaced within distances of 3 m from each other in two parallel galleries of 14 m 2 , separated by a pillar of 10 m thickness. They will be heated up by a power output of approx. 1 kW/m to 200 degree C surface temperature by electrical heaters. The thermal and mechanical response of the salt rock and the backfilling to the artificial heating is to be investigated as follows: (1) measurement of the temperature field at the contained surface, in the backfill and in the rock salt; (2) deformation measurements of the salt rock around the heated drifts; (3) measurements of tunnel convergence in heated and unheated sections; (4) compaction measurements of the backfilling in heated and unheated areas; (5) measurement of rock stresses in areas very close to the galleries; and (6) pressure measurements in the backfilling, between backfilling and rock, and between backfilling and containers. The rock burst monitoring system of the Asse salt mine will be expanded to this special field of the mine to detect seismic events due to thermomechanical effects. Another seismoacoustic system will be installed to observe the compaction of the backfilling. This system must be calibrated for the relation between the density and velocities of seismic waves. It is planned to monitor the density by gamma-gamma log measurements. The changes in overall density during the entire experiment will be observed by gravimeter measurements of high precision

  9. The Art Gallery Test: A Preliminary Comparison between Traditional Neuropsychological and Ecological VR-Based Tests

    Directory of Open Access Journals (Sweden)

    Pedro Gamito

    2017-11-01

    Full Text Available Ecological validity should be the cornerstone of any assessment of cognitive functioning. For this purpose, we have developed a preliminary study to test the Art Gallery Test (AGT as an alternative to traditional neuropsychological testing. The AGT involves three visual search subtests displayed in a virtual reality (VR art gallery, designed to assess visual attention within an ecologically valid setting. To evaluate the relation between AGT and standard neuropsychological assessment scales, data were collected on a normative sample of healthy adults (n = 30. The measures consisted of concurrent paper-and-pencil neuropsychological measures [Montreal Cognitive Assessment (MoCA, Frontal Assessment Battery (FAB, and Color Trails Test (CTT] along with the outcomes from the three subtests of the AGT. The results showed significant correlations between the AGT subtests describing different visual search exercises strategies with global and specific cognitive measures. Comparative visual search was associated with attention and cognitive flexibility (CTT; whereas visual searches involving pictograms correlated with global cognitive function (MoCA.

  10. Ultrahigh Sensitivity Piezoresistive Pressure Sensors for Detection of Tiny Pressure.

    Science.gov (United States)

    Li, Hongwei; Wu, Kunjie; Xu, Zeyang; Wang, Zhongwu; Meng, Yancheng; Li, Liqiang

    2018-05-31

    High sensitivity pressure sensors are crucial for the ultra-sensitive touch technology and E-skin, especially at the tiny pressure range below 100 Pa. However, it is highly challenging to substantially promote sensitivity beyond the current level at several to two hundred kPa -1 , and to improve the detection limit lower than 0.1 Pa, which is significant for the development of pressure sensors toward ultrasensitive and highly precise detection. Here, we develop an efficient strategy to greatly improve the sensitivity near to 2000 kPa -1 by using short channel coplanar device structure and sharp microstructure, which is systematically proposed for the first time and rationalized by the mathematic calculation and analysis. Significantly, benefiting from the ultrahigh sensitivity, the detection limit is improved to be as small as 0.075 Pa. The sensitivity and detection limit are both superior to the current levels, and far surpass the function of human skin. Furthermore, the sensor shows fast response time (50 μs), excellent reproducibility and stability, and low power consumption. Remarkably, the sensor shows excellent detection capacity in the tiny pressure range including LED switching with a pressure of 7 Pa, ringtone (2-20 Pa) recognition, and ultrasensitive (0.1 Pa) electronic glove. This work represents a performance and strategic progress in the field of pressure sensing.

  11. Victorian era esthetic and restorative dentistry: an advertising trade card gallery.

    Science.gov (United States)

    Croll, Theodore P; Swanson, Ben Z

    2006-01-01

    A chief means of print advertising in the Victorian era was the "trade card." Innumerable products, companies, and services were highlighted on colorful chromolithographic trade cards, and these became desirable collectible objects which were pasted into scrapbooks and enjoyed by many families. Dentistry- and oral health-related subjects were often depicted on Victorian trade cards, and esthetic and restorative dentistry themes were featured. This review describes the history of advertising trade cards and offers a photographic gallery of dentistry-related cards of the era.

  12. Retention of external and internal markers by southern pine beetles (Coleoptera: Scolytidae) during gallery

    Science.gov (United States)

    Douglas J. Rhodes; Jane Leslie Hayes; Chris Steiner

    1998-01-01

    If retained, markers used in mark-release-recapture studies of bark beetle dispersal could provide valuable tools in the determination of post-dispersal fate. Retention of the internal marker rubidium (Rb) and of the external marker fluorescent powder during egg gallery construction, oviposition, and feeding were quantified at intervals from 0 to 96 hours by allowing...

  13. The science of tiny things: physics at the nanoscale

    Energy Technology Data Exchange (ETDEWEB)

    Copp, Stacy Marla [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-06-07

    Nanoscience is the study of tiny objects that are only a billionth of a meter in size, or about 1,000 to 10,000 times smaller than a human hair. From the electronics in your smartphone to the molecular motors that are in your body’s cells, nanoscientists study and design materials that span a huge range of subjects, from physics to chemistry to biology. I will talk about some of what we do at LANL’s Center for Integrated Technologies, as well as how I first got interested in nanoscience and how I became a nanoscientist at LANL.

  14. License - Togo Picture Gallery | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available List Contact us Togo Picture Gallery License License to Use This Database Last updated : 2017/05/16 You may use this database...ecifies the license terms regarding the use of this database and the requirements you must follow in using this database.... The license for this database is specified in the Creative Commons ...Attribution 4.0 International . If you use data from this database, please be sure attribute this database a...e Creative Commons Attribution 4.0 International is found here . With regard to this database

  15. Micromechanical characteristics of an Al/sub 2/O/sub 3/-TiNi ceramic produced in a high-pressure chamber

    Energy Technology Data Exchange (ETDEWEB)

    Barashkov, G.A.; Neshpor, V.S.; Berdikov, V.F.; Pushkarev, O.I.; Lavrenova, E. A.

    1987-03-01

    The micromechanical characteristics of an Al/sub 2/O/sub 3/-TiNi ceramic produced in high-pressure chambers under conditions of forced mass transfer are investigated experimentally using the microindentation method. The objective of the study is to use micromechanical characteristics to determine the time required for producing an Al/sub 2/O/sub 3/-TiNi ceramic with a fully formed structure. It is found that the process of forced mass transfer and crystallization is completed within 60-120 s.

  16. Structural characterization of the gallery forest of the Guisa Agroforestry Experimental Station

    Directory of Open Access Journals (Sweden)

    José Luis Rodríguez Sosa

    2018-01-01

    Full Text Available The work was carried out in the gallery forest of the Cupaynicú stream, belonging to the Guisa Agroforestry Experimental Station, with the objective of characterizing its structure. Eight parcels of 500 m2 were randomly raised, in them the species were identified, their height and diameter were measured. The flora was analyzed through the origin of the species and the frequency histogram. The structure of the forest was analyzed through the diametric structure and the Value Index of Ecological Importance, the vertical structure was described taking into consideration the forest strata as well as the preparation of the canopy diagram. A descriptive analysis of the parameters diameter, height and basal area was made to study the parametric structure. The richness of the riparian forest was evidenced by the registry of 25 families, 40 genera and 43 species, as well as the predominance of the Meliaceae family followed by Lauraceae, Mimosaceae and Sapindaceae, which reflects the high timber value, melliferous and ecological of the same. The species Roystonea regia, Sterculiaapetala, Dendropanaxarboreus, Andirainermis and Mangifera indica, determine the physiognomy of the gallery Forest. The trees reach 33 cm in diameter and 18.27 m in height on average, although the presence of trees with 30 m is the most frequent, which denotes the irregular structure of the forest.

  17. High frequency of trypanosomatids in gallery forest bats of a Neotropical savanna.

    Science.gov (United States)

    Lourenço, João Lucas M; Minuzzi-Souza, Thaís T C; Silva, Larissa R; Oliveira, Amanda C; Mendonça, Vagner J; Nitz, Nadjar; Aguiar, Ludmilla M S; Gurgel-Gonçalves, Rodrigo

    2018-01-01

    Bats are well-known hosts of trypanosomatids, though information about their role as reservoirs of these protozoans in the Brazilian savanna is poorly known. We aimed to analyze the occurrence of trypanosomatid species in bats occurring in remnants of gallery forests of Brasília, Federal District of Brazil. We sampled bats using mist nets in six sites, and we collected blood, wing fragments and oral swab samples from all captured individuals. Trypanosomatids were identified in the captured bats through sequencing of the SSUrRNA region and kDNA qPCR. We found no parasite in blood smears of 146 individuals of 14 species captured, but blood cultures were positive for nine bats. We detected trypanosomatids molecularly in 111 (76%) specimens of all bat species in the studied areas. Most of the infected bats had Leishmania-like DNA detected in blood and swab samples of the oral mucosa. We distinguished three species of Trypanosoma (Trypanosoma dionisii, T. rangeli and T. cruzi) in Carollia perspicillata. SSUrRNA PCR of oral samples is a non-invasive and practical method for identification of trypanosomatid species in bats. Our results support our belief that bats could be potential reservoirs for Trypanosoma and Leishmania-like species in the enzootic cycle of these parasites in gallery forests of the Brazilian Cerrado biome. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Rael Artel Gallery: Non-Profit Project Space : short tale of an experimental project's space tactics / Kiwa

    Index Scriptorium Estoniae

    Kiwa, pseud., 1975-

    2009-01-01

    Aastatel 2004-2008 Pärnus ja aastatel 2006-2008 Tartus tegutsenud Rael Artel Galeriist, mille looja ja moderaator oli Rael Artel. Galerii tegevus lõppes kunstialbumi "Hotell Pärnu : Rael Arel Gallery : Non Profit Project Space 2004-2008 / kontseptsioon ja toimetamine: Rael Artel" ilmumisega 2009. aastal

  19. Telerobotic Haptic Exploration in Art Galleries and Museums for Individuals with Visual Impairments.

    Science.gov (United States)

    Park, Chung Hyuk; Ryu, Eun-Seok; Howard, Ayanna M

    2015-01-01

    This paper presents a haptic telepresence system that enables visually impaired users to explore locations with rich visual observation such as art galleries and museums by using a telepresence robot, a RGB-D sensor (color and depth camera), and a haptic interface. The recent improvement on RGB-D sensors has enabled real-time access to 3D spatial information in the form of point clouds. However, the real-time representation of this data in the form of tangible haptic experience has not been challenged enough, especially in the case of telepresence for individuals with visual impairments. Thus, the proposed system addresses the real-time haptic exploration of remote 3D information through video encoding and real-time 3D haptic rendering of the remote real-world environment. This paper investigates two scenarios in haptic telepresence, i.e., mobile navigation and object exploration in a remote environment. Participants with and without visual impairments participated in our experiments based on the two scenarios, and the system performance was validated. In conclusion, the proposed framework provides a new methodology of haptic telepresence for individuals with visual impairments by providing an enhanced interactive experience where they can remotely access public places (art galleries and museums) with the aid of haptic modality and robotic telepresence.

  20. (Updated) Nanotechnology: Understanding the Tiny Particles That May Save a Life | Poster

    Science.gov (United States)

    By Nathalie Walker, Guest Writer Could nanotechnology—the study of tiny matter ranging in size from 1 to 200 nanometers—be the future of cancer treatment? Although it is a relatively new field in cancer research, nanotechnology is not new to everyday life. Have you ever thought about the tennis ball you’ve thrown with your dog at the park and wondered what it is made of?

  1. Video gallery of educational lectures integrated in faculty's portal

    Directory of Open Access Journals (Sweden)

    Jaroslav Majerník

    2013-05-01

    Full Text Available This paper presents a web based educational video-clips exhibition created to share various archived lectures for medical students, health care professionals as well as for general public. The presentation of closely related topics was developed as video gallery and it is based solely on free or open source tools to be available for wide academic and/or non-commercial use. Even if the educational video records can be embedded in any websites, we preferred to use our faculty’s portal, which should be a central point to offer various multimedia educational materials. The system was integrated and tested to offer open access to infectology lectures that were captured and archived from live-streamed sessions and from videoconferences.

  2. miRToolsGallery: a tag-based and rankable microRNA bioinformatics resources database portal

    Science.gov (United States)

    Chen, Liang; Heikkinen, Liisa; Wang, ChangLiang; Yang, Yang; Knott, K Emily

    2018-01-01

    Abstract Hundreds of bioinformatics tools have been developed for MicroRNA (miRNA) investigations including those used for identification, target prediction, structure and expression profile analysis. However, finding the correct tool for a specific application requires the tedious and laborious process of locating, downloading, testing and validating the appropriate tool from a group of nearly a thousand. In order to facilitate this process, we developed a novel database portal named miRToolsGallery. We constructed the portal by manually curating > 950 miRNA analysis tools and resources. In the portal, a query to locate the appropriate tool is expedited by being searchable, filterable and rankable. The ranking feature is vital to quickly identify and prioritize the more useful from the obscure tools. Tools are ranked via different criteria including the PageRank algorithm, date of publication, number of citations, average of votes and number of publications. miRToolsGallery provides links and data for the comprehensive collection of currently available miRNA tools with a ranking function which can be adjusted using different criteria according to specific requirements. Database URL: http://www.mirtoolsgallery.org PMID:29688355

  3. Mega-pixel PQR laser chips for interconnect, display ITS, and biocell-tweezers OEIC

    Science.gov (United States)

    Kwon, O'Dae; Yoon, J. H.; Kim, D. K.; Kim, Y. C.; Lee, S. E.; Kim, S. S.

    2008-02-01

    We describe a photonic quantum ring (PQR) laser device of three dimensional toroidal whispering gallery cavity. We have succeeded in fabricating the first genuine mega-pixel laser chips via regular semiconductor technology. This has been realized since the present injection laser emitting surface-normal dominant 3D whispering gallery modes (WGMs) can be operated CW with extremely low operating currents (μA-nA per pixel), together with the lasing temperature stabilities well above 140 deg C with minimal redshifts, which solves the well-known integration problems facing the conventional VCSEL. Such properties unusual for quantum well lasers become usual because the active region, involving vertically confining DBR structure in addition to the 2D concave WGM geometry, induces a 'photonic quantum ring (PQR)-like' carrier distribution through a photonic quantum corral effect. A few applications of such mega-pixel PQR chips are explained as follows: (A) Next-generation 3D semiconductor technologies demand a strategy on the inter-chip and intra-chip optical interconnect schemes with a key to the high-density emitter array. (B) Due to mounting traffic problems and fatalities ITS technology today is looking for a revolutionary change in the technology. We will thus outline how 'SLEEP-ITS' can emerge with the PQR's position-sensing capability. (C) We describe a recent PQR 'hole' laser of convex WGM: Mega-pixel PQR 'hole' laser chips are even easier to fabricate than PQR 'mesa' lasers. Genuine Laguerre-Gaussian (LG) beam patterns of PQR holes are very promising for biocell manipulations like sorting mouse myeloid leukemia (M1s) cells. (D) Energy saving and 3D speckle-free POR laser can outdo LEDs in view of red GaAs and blue GaN devices fabricated recently.

  4. Analysis of the transformations temperatures of helicoidal Ti-Ni actuators using computational numerical methods

    Directory of Open Access Journals (Sweden)

    Carlos Augusto do N. Oliveira

    2013-01-01

    Full Text Available The development of shape memory actuators has enabled noteworthy applications in the mechanical engineering, robotics, aerospace, and oil industries and in medicine. These applications have been targeted on miniaturization and taking full advantage of spaces. This article analyses a Ti-Ni shape memory actuator used as part of a flow control system. A Ti-Ni spring actuator is subjected to thermomechanical training and parameters such as transformation temperature, thermal hysteresis and shape memory effect performance were investigated. These parameters were important for understanding the behavior of the actuator related to martensitic phase transformation during the heating and cooling cycles which it undergoes when in service. The multiple regression methodology was used as a computational tool for analysing data in order to simulate and predict the results for stress and cycles where the experimental data was not developed. The results obtained using the training cycles enable actuators to be characterized and the numerical simulation to be validated.

  5. Detection of tiny amounts of fissile materials in large-sized containers with radioactive waste

    Science.gov (United States)

    Batyaev, V. F.; Skliarov, S. V.

    2018-01-01

    The paper is devoted to non-destructive control of tiny amounts of fissile materials in large-sized containers filled with radioactive waste (RAW). The aim of this work is to model an active neutron interrogation facility for detection of fissile ma-terials inside NZK type containers with RAW and determine the minimal detectable mass of U-235 as a function of various param-eters: matrix type, nonuniformity of container filling, neutron gen-erator parameters (flux, pulse frequency, pulse duration), meas-urement time. As a result the dependence of minimal detectable mass on fissile materials location inside container is shown. Nonu-niformity of the thermal neutron flux inside a container is the main reason of the space-heterogeneity of minimal detectable mass in-side a large-sized container. Our experiments with tiny amounts of uranium-235 (<1 g) confirm the detection of fissile materials in NZK containers by using active neutron interrogation technique.

  6. Detection of tiny amounts of fissile materials in large-sized containers with radioactive waste

    Directory of Open Access Journals (Sweden)

    Batyaev V.F.

    2018-01-01

    Full Text Available The paper is devoted to non-destructive control of tiny amounts of fissile materials in large-sized containers filled with radioactive waste (RAW. The aim of this work is to model an active neutron interrogation facility for detection of fissile ma-terials inside NZK type containers with RAW and determine the minimal detectable mass of U-235 as a function of various param-eters: matrix type, nonuniformity of container filling, neutron gen-erator parameters (flux, pulse frequency, pulse duration, meas-urement time. As a result the dependence of minimal detectable mass on fissile materials location inside container is shown. Nonu-niformity of the thermal neutron flux inside a container is the main reason of the space-heterogeneity of minimal detectable mass in-side a large-sized container. Our experiments with tiny amounts of uranium-235 (<1 g confirm the detection of fissile materials in NZK containers by using active neutron interrogation technique.

  7. Time-efficient CT colonography interpretation using an advanced image-gallery-based, computer-aided ''first-reader'' workflow for the detection of colorectal adenomas

    International Nuclear Information System (INIS)

    Mang, Thomas; Ringl, Helmut; Weber, Michael; Mueller-Mang, Christina; Hermosillo, Gerardo; Wolf, Matthias; Bogoni, Luca; Salganicoff, Marcos; Raykar, Vikas; Graser, Anno

    2012-01-01

    To assess the performance of an advanced ''first-reader'' workflow for computer-aided detection (CAD) of colorectal adenomas ≥ 6 mm at computed tomographic colonography (CTC) in a low-prevalence cohort. A total of 616 colonoscopy-validated CTC patient-datasets were retrospectively reviewed by a radiologist using a ''first-reader'' CAD workflow. CAD detections were presented as galleries of six automatically generated two-dimensional (2D) and three-dimensional (3D) images together with interactive 3D target views and 2D multiplanar views of the complete dataset. Each patient-dataset was interpreted by initially using CAD image-galleries followed by a fast 2D review to address unprompted colonic areas. Per-patient, per-polyp, and per-adenoma sensitivities were calculated for lesions ≥ 6 mm. Statistical testing employed Fisher's exact and McNemar tests. In 91/616 patients, 131 polyps (92 adenomas, 39 non-adenomas) ≥ 6 mm and two cancers were identified by reference standard. Using the CAD gallery-based first-reader workflow, the radiologist detected all adenomas ≥ 10 mm (34/34) and cancers. Per-patient and polyp sensitivities for lesions ≥ 6 mm were 84.3 % (75/89), and 83.2 % (109/131), respectively, with 89.1 % (57/64) and 85.9 % (79/92) for adenomas. Overall specificity was 95.6 % (504/527). Mean interpretation time was 3.1 min per patient. A CAD algorithm, applied in an image-gallery-based first-reader workflow, can substantially decrease reading times while enabling accurate detection of colorectal adenomas in a low-prevalence population. (orig.)

  8. Electron irradiation effect on the reverse phase transformation temperatures in TiNi shape memory alloy thin films

    International Nuclear Information System (INIS)

    Wang, Z.G.; Zu, X.T.; Fu, Y.Q.; Zhu, S.; Wang, L.M.

    2005-01-01

    In this work, Ti-Ni shape memory alloy thin films were irradiated by 1.7 MeV electron with three types of fluences: 4 x 10 20 , 7 x 10 20 and 1 x 10 21 /m 2 . The influence of electron irradiation on the transformation behavior of the TiNi thin films were investigated by differential scanning calorimetry. The transformation temperatures A s and A f shifted to higher temperature after electron irradiation, the martensite was stabilized. The electron irradiation effect can be easily eliminated by one thermal cycle. The shifts of the transformation temperatures can be explained from the change of potential energy barrier and coherency energy between parent phase and martensite after irradiation

  9. Plasmonic colour generation

    DEFF Research Database (Denmark)

    Kristensen, Anders; Yang, Joel K. W.; Bozhevolnyi, Sergey I.

    2016-01-01

    Plasmonic colours are structural colours that emerge from resonant interactions between light and metallic nanostructures. The engineering of plasmonic colours is a promising, rapidly emerging research field that could have a large technological impact. We highlight basic properties of plasmonic...... colours and recent nanofabrication developments, comparing technology-performance indicators for traditional and nanophotonic colour technologies. The structures of interest include diffraction gratings, nanoaperture arrays, thin films, and multilayers and structures that support Mie resonances...... and whispering-gallery modes. We discuss plasmonic colour nanotechnology based on localized surface plasmon resonances, such as gap plasmons and hybridized disk–hole plasmons, which allow for colour printing with sub-diffraction resolution. We also address a range of fabrication approaches that enable large...

  10. Methodics of computing the results of monitoring the exploratory gallery

    Directory of Open Access Journals (Sweden)

    Krúpa Víazoslav

    2000-09-01

    Full Text Available At building site of motorway tunnel Višòové-Dubná skala , the priority is given to driving of exploration galley that secures in detail: geologic, engineering geology, hydrogeology and geotechnics research. This research is based on gathering information for a supposed use of the full profile driving machine that would drive the motorway tunnel. From a part of the exploration gallery which is driven by the TBM method, a fulfilling information is gathered about the parameters of the driving process , those are gathered by a computer monitoring system. The system is mounted on a driving machine. This monitoring system is based on the industrial computer PC 104. It records 4 basic values of the driving process: the electromotor performance of the driving machine Voest-Alpine ATB 35HA, the speed of driving advance, the rotation speed of the disintegrating head TBM and the total head pressure. The pressure force is evaluated from the pressure in the hydraulic cylinders of the machine. Out of these values, the strength of rock mass, the angle of inner friction, etc. are mathematically calculated. These values characterize rock mass properties as their changes. To define the effectivity of the driving process, the value of specific energy and the working ability of driving head is used. The article defines the methodics of computing the gathered monitoring information, that is prepared for the driving machine Voest – Alpine ATB 35H at the Institute of Geotechnics SAS. It describes the input forms (protocols of the developed method created by an EXCEL program and shows selected samples of the graphical elaboration of the first monitoring results obtained from exploratory gallery driving process in the Višòové – Dubná skala motorway tunnel.

  11. Exogenously applied D-pinitol and D-chiro-inositol modifies the accumulation of α-D-galactosides in developing tiny vetch (Vicia hirsuta [L.] S.F. Gray seeds

    Directory of Open Access Journals (Sweden)

    Lesław B. Lahuta

    2011-01-01

    Full Text Available In the present study we have investigated the effect of exogenous cyclitols on the accumulation of their galactosides and raffinose family oligosaccharides (RFOs, as well as on some enzymes important for their biosynthesis in seeds of tiny vetch (Vicia hirsuta [L.] S.F. Gray. Immature seeds during 6-day incubation with D-chiro-inositol (naturally does not appear in seeds of tiny vetch were accumulated cyclitol and its galactosides (fagopyritols: B1 and B2. Short 4-hour incubation with D-chiro-inositol, and subsequent slow desiccation process caused accumulation of free cyclitol only, without biosynthesis of its galactosides. Feeding D-chiro-inositol to pods of tiny vetch induced accumulation of high levels of its galactosides (fagopyritol B1, B2 and B3 in maturing seeds. Similarly, feeding D-pinitol increased accumulation of its mono-, di- and tri-galactosides: GPA, GPB, DGPA and TGPA in tiny vetch seed. Accumulation of both cyclitols and their galactosides drastically reduced accumulation of verbascose. Inhibition of RFOs biosynthesis by elevated levels of free cyclitols suggests some competition between formation of both types of galactosides and similarity of both biosynthetic routes in tiny vetch seeds. Galactinol synthase (GolS from tiny vetch seeds demonstrated ability to utilize D-chiro-inositol as galactosyl acceptor, instead of myo-inositol. Presence of both cyclitols, as substrates for GolS, caused synthesis of their galactosides: fagopyritol B1 and galactinol. However, formation of galactinol was more efficient than fagopyritol B1. D-chiro-Inositol and D-pinitol at concentrations several-fold higher than myo-inositol had inhibitory effect on GolS. Thus, we suggest that a level of free cyclitols can have an influence on the rate of galactinol biosynthesis and further accumulation of RFOs and galactosyl cyclitols in tiny vetch seeds.

  12. The potential of Lemna gibba L. and Lemna minor L. to remove Cu, Pb, Zn, and As in gallery water in a mining area in Keban, Turkey.

    Science.gov (United States)

    Sasmaz, Merve; Arslan Topal, Emine Işıl; Obek, Erdal; Sasmaz, Ahmet

    2015-11-01

    This study was designed to investigate removal efficiencies of Cu, Pb, Zn, and As in gallery water in a mining area in Keban, Turkey by Lemna gibba L. and Lemna minor L. These plants were placed in the gallery water of Keban Pb-Zn ore deposits and adapted individually fed to the reactors. During the study period (8 days), the plant and water samples were collected daily and the temperature, pH, and electric conductivity of the gallery water were measured daily. The plants were washed, dried, and burned at 300 °C for 24 h in a drying oven. These ash and water samples were analyzed by ICP-MS to determine the amounts of Cu, Pb, Zn, and As. The Cu, Pb, Zn and As concentrations in the gallery water of the study area detected 67, 7.5, 7230, and 96 μg L(-1), respectively. According to the results, the obtained efficiencies in L. minor L. and L. gibba L. are: 87% at day 2 and 36% at day 3 for Cu; 1259% at day 2 and 1015% at day 2 for Pb; 628% at day 3 and 382% at day 3 for Zn; and 7070% at day 3 and 19,709% at day 2 for As, respectively. The present study revealed that both L. minor L. and L. gibba L. had very high potential to remove Cu, Pb, Zn, and As in gallery water contaminated by different ores. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  13. Growth and surface morphology of ion-beam sputtered Ti-Ni thin films

    International Nuclear Information System (INIS)

    Rao, Ambati Pulla; Sunandana, C.S.

    2008-01-01

    Titanium-nickel thin films have been deposited on float glass substrates by ion beam sputtering in 100% pure argon atmosphere. Sputtering is predominant at energy region of incident ions, 1000 eV to 100 keV. The as-deposited films were investigated by X-ray photoelectron spectroscopy (XPS) and atomic force microscope (AFM). In this paper we attempted to study the surface morphology and elemental composition through AFM and XPS, respectively. Core level as well as valence band spectra of ion-beam sputtered Ti-Ni thin films at various Ar gas rates (5, 7 and 12 sccm) show that the thin film deposited at 3 sccm possess two distinct peaks at binding energies 458.55 eV and 464.36 eV mainly due to TiO 2 . Upon increasing Ar rate oxidation of Ti-Ni is reduced and the Ti-2p peaks begin approaching those of pure elemental Ti. Here Ti-2p peaks are observed at binding energy positions of 454.7 eV and 460.5 eV. AFM results show that the average grain size and roughness decrease, upon increasing Ar gas rate, from 2.90 μm to 0.096 μm and from 16.285 nm to 1.169 nm, respectively

  14. Radiometric survey in the sites of Regional office in Fortaleza, research gallery and camp in Itataia, CE (Brazil)

    International Nuclear Information System (INIS)

    1982-02-01

    The radiometric survey in Regional officer sites in Fortaleza, Brazil, research gallery and camp in Itataia is presented. The measurings to be done, the instrumentation used and results obtained are described as well as the conclusions and recommendations. (C.M.) [pt

  15. Contemporary Adult Education Philosophies and Practices in Art Galleries and Museums in Canada and the UK

    Science.gov (United States)

    Clover, Darlene E.; Bell, Lorraine

    2013-01-01

    Public art galleries and museums have been mandated to become more relevant and useful to the lived experiences of the broad communities they claim to serve. Adult education has long been part of the work of these institutions, although historically the relationship has been uneasy, and they seldom feature in the adult education literature. To…

  16. Optical Comb from a Whispering Gallery Mode Resonator for Spectroscopy and Astronomy Instruments Calibration

    Science.gov (United States)

    Strekalov, Dmitry V.; Yu, Nam; Thompson, Robert J.

    2012-01-01

    The most accurate astronomical data is available from space-based observations that are not impeded by the Earth's atmosphere. Such measurements may require spectral samples taken as long as decades apart, with the 1 cm/s velocity precision integrated over a broad wavelength range. This raises the requirements specifically for instruments used in astrophysics research missions -- their stringent wavelength resolution and accuracy must be maintained over years and possibly decades. Therefore, a stable and broadband optical calibration technique compatible with spaceflights becomes essential. The space-based spectroscopic instruments need to be calibrated in situ, which puts forth specific requirements to the calibration sources, mainly concerned with their mass, power consumption, and reliability. A high-precision, high-resolution reference wavelength comb source for astronomical and astrophysics spectroscopic observations has been developed that is deployable in space. The optical comb will be used for wavelength calibrations of spectrographs and will enable Doppler measurements to better than 10 cm/s precision, one hundred times better than the current state-of-the- art.

  17. Design considerations in achieving 1 MW CW operation with a whispering-gallery-mode gyrotron

    International Nuclear Information System (INIS)

    Felch, K.; Feinstein, J.; Hess, C.; Huey, H.; Jongewaard, E.; Jory, H.; Neilson, J.; Pendleton, R.; Pirkle, D.; Zitelli, L.

    1989-09-01

    Varian is developing high-power, CW gyrotrons at frequencies in the range 100 GHz to 150 GHz, for use in electron cyclotron heating applications. Early test vehicles have utilized a TE 15,2,1 interaction cavity, have achieved short-pulse power levels of 820 kW and average power levels of 80 kW at 140 GHz. Present tests are aimed at reaching 400 kW under CW operating conditions and up to 1 MW for short pulse durations. Work is also underway on modifications to the present design that will enable power levels of up to 1 MW CW to be achieved. 7 refs., 2 figs

  18. An Insurgent Curatorial Strategy: Using Dialogue and Collaboration to Create Meaning in Public Art Galleries and Museums

    Science.gov (United States)

    Marsden, Scott

    2018-01-01

    My insurgent curatorial strategy incorporates theory around dialogue and is used to develop a participatory and collaborative process that gives voice to those who are marginalised and/or disfranchised and are suppressed by dominant social narratives. My strategy demonstrates how art galleries and museums can function as sites for community…

  19. The influence of the substrate on the adhesive strength of the micro-arc oxidation coating developed on TiNi shape memory alloy

    Science.gov (United States)

    Hsieh, Shy-Feng; Ou, Shih-Fu; Chou, Chia-Kai

    2017-01-01

    TiNi shape memory alloys (SMAs), used as long-term implant materials, have a disadvantage. Ni-ion release from the alloys may trigger allergies in the human body. Micro-arc oxidation has been utilized to modify the surface of the TiNi SMA for improving its corrosion resistance and biocompatibility. However, there are very few reports investigating the essential adhesive strength between the micro-arc oxidized film and TiNi SMA. Two primary goals were attained by this study. First, Ti50Ni48.5Mo1.5 SMA having a phase transformation temperature (Af) less than body temperature and good shape recovery were prepared. Next, the Ti50Ni50 and Ti50Ni48.5Mo1.5 SMA surfaces were modified by micro-arc oxidation in phosphoric acid by applying relatively low voltages to maintain the adhesive strength. The results indicated that the pore size, film thickness, and P content increased with applied voltage. The micro-arc oxidized film, comprising Ti oxides, Ni oxide, and phosphate compounds, exhibited a glassy amorphous structure. The outmost surface of the micro-arc oxidized film contained a large amount of P (>12 at%) but only a trace of Ni (micro-arc oxidized films exceeded the requirements of ISO 13779. Furthermore, Mo addition into TiNi SMAs was found to be favorable for improving the adhesive strength of the micro-arc oxidized film.

  20. Advances of Optofluidic Microcavities for Microlasers and Biosensors

    Directory of Open Access Journals (Sweden)

    Zhiqing Feng

    2018-03-01

    Full Text Available Optofluidic microcavities with high Q factor have made rapid progress in recent years by using various micro-structures. On one hand, they are applied to microfluidic lasers with low excitation thresholds. On the other hand, they inspire the innovation of new biosensing devices with excellent performance. In this article, the recent advances in the microlaser research and the biochemical sensing field will be reviewed. The former will be categorized based on the structures of optical resonant cavities such as the Fabry–Pérot cavity and whispering gallery mode, and the latter will be classified based on the working principles into active sensors and passive sensors. Moreover, the difficulty of single-chip integration and recent endeavors will be briefly discussed.

  1. Adiabatic tapered optical fiber fabrication in two step etching

    Science.gov (United States)

    Chenari, Z.; Latifi, H.; Ghamari, S.; Hashemi, R. S.; Doroodmand, F.

    2016-01-01

    A two-step etching method using HF acid and Buffered HF is proposed to fabricate adiabatic biconical optical fiber tapers. Due to the fact that the etching rate in second step is almost 3 times slower than the previous droplet etching method, terminating the fabrication process is controllable enough to achieve a desirable fiber diameter. By monitoring transmitted spectrum, final diameter and adiabaticity of tapers are deduced. Tapers with losses about 0.3 dB in air and 4.2 dB in water are produced. The biconical fiber taper fabricated using this method is used to excite whispering gallery modes (WGMs) on a microsphere surface in an aquatic environment. So that they are suitable to be used in applications like WGM biosensors.

  2. Aptamer Based Microsphere Biosensor for Thrombin Detection

    Directory of Open Access Journals (Sweden)

    Xudong Fan

    2006-08-01

    Full Text Available We have developed an optical microsphere resonator biosensor using aptamer asreceptor for the measurement of the important biomolecule thrombin. The sphere surface ismodified with anti-thrombin aptamer, which has excellent binding affinity and selectivityfor thrombin. Binding of the thrombin at the sphere surface is monitored by the spectralposition of the microsphere’s whispering gallery mode resonances. A detection limit on theorder of 1 NIH Unit/mL is demonstrated. Control experiments with non-aptameroligonucleotide and BSA are also carried out to confirm the specific binding betweenaptamer and thrombin. We expect that this demonstration will lead to the development ofhighly sensitive biomarker sensors based on aptamer with lower cost and higher throughputthan current technology.

  3. Cascading second-order nonlinear processes in a lithium niobate-on-insulator microdisk.

    Science.gov (United States)

    Liu, Shijie; Zheng, Yuanlin; Chen, Xianfeng

    2017-09-15

    Whispering-gallery-mode (WGM) microcavities are very important in both fundamental science and practical applications, among which on-chip second-order nonlinear microresonators play an important role in integrated photonic functionalities. Here we demonstrate resonant second-harmonic generation (SHG) and cascaded third-harmonic generation (THG) in a lithium niobate-on-insulator (LNOI) microdisk resonator. Efficient SHG in the visible range was obtained with only several mW input powers at telecom wavelengths. THG was also observed through a cascading process, which reveals simultaneous phase matching and strong mode coupling in the resonator. Cascading of second-order nonlinear processes gives rise to an effectively large third-order nonlinearity, which makes on-chip second-order nonlinear microresonators a promising frequency converter for integrated nonlinear photonics.

  4. Betsy Pugel, Tiny houses: Planetary protection-focused materials selection for spaceflight hardware surfaces

    OpenAIRE

    Schriml, Lynn

    2017-01-01

    Betsy Pugel, National Aeronautics and Space Administration Tiny houses: Planetary protection-focused materials selection for spaceflight hardware surfacesOn October 10-12th, 2017 the Alfred P. Sloan Foundation and The National Academies of Sciences, Engineering and Medicine co-hosting MoBE 2017 (Microbiology of the Built Environment Research and Applications Symposium) at the National Academy of Sciences Building to present the current state-of-the-science in understanding the formation and ...

  5. Change of texture, microdeformation and hardness in surface layer of TiNi alloy depending on the number of pulses of electron beam effects

    International Nuclear Information System (INIS)

    Meisner, L. L.; Meisner, S. N.; Markov, A. B.; Yakovlev, E. V.; Ozur, G. E.; Rotshtein, V. P.; Mironov, Yu. P.

    2015-01-01

    This work comprises a study of the influence of the pulse number of low-energy high-current electron beam (LEHCEB) exposure on the value and character of distribution of residual elastic stresses, texturing effects and the relationship between structural-phase states and physical and mechanical properties of the modified surface layers of TiNi alloy. LEHCEB processing of the surface of TiNi samples was carried out using a RITM-SP [3] installation. Energy density of electron beam was constant at E s = 3.9 ± 0.5 J/cm 2 ; pulse duration was 2.8 ± 0.3 μs. The number of pulses in the series was changeable, (n = 2–128). It was shown that as the result of multiple LEHCEB processing of TiNi samples, hierarchically organized multilayer structure is formed in the surface layer. The residual stress field of planar type is formed in the modified surface layer as following: in the direction of the normal to the surface the strain component ε ⊥ < 0 (compressing strain), and in a direction parallel to the surface, the strain component ε || > 0 (tensile deformation). Texturing effects and the level of residual stresses after LEHCEB processing of TiNi samples with equal energy density of electron beam (∼3.8 J/cm 2 ) depend on the number of pulses and increase with the rise of n > 10

  6. Social Phenomenological Analysis as a Research Method in Art Education: Developing an Empirical Model for Understanding Gallery Talks

    Science.gov (United States)

    Hofmann, Fabian

    2016-01-01

    Social phenomenological analysis is presented as a research method to study gallery talks or guided tours in art museums. The research method is based on the philosophical considerations of Edmund Husserl and sociological/social science concepts put forward by Max Weber and Alfred Schuetz. Its starting point is the everyday lifeworld; the…

  7. Exhibiting Western Desert Aboriginal painting in Australia’s public galleries: an institutional analysis, 1981-2002

    OpenAIRE

    Jim Berryman

    2012-01-01

    This paper documents and analyses the exhibition history of Aboriginal painting in Australia’s public art galleries over a two-decade period. It concentrates on Western Desert acrylics but is not confined to this movement or region alone. Based on a review of catalogues from key exhibitions, it identifies three interpretative frameworks used by curators to validate the presence of Aboriginal painting in the contemporary art realm. These modes of interpretation are called the aesthetic, ethnog...

  8. Lesbian identity and the politics of representation in Betty Parsons's gallery.

    Science.gov (United States)

    Gibson, A

    1994-01-01

    Although Betty Parsons had been unusually open about her love relationships with women in the twenties and thirties, she later became reticent, retiring to the closet. Her increased discretion after World War II, during the Cold War, coincided with her rise as the art dealer most prominently associated with the international emergence of Abstract Expressionism. Parsons incurred the objections of her Abstract Expressionists, however, by showing artists who included both abstraction and naturalism in their work, such as Sonia Sekula, Forrest Bess, and Hedda Sterne. This article examines her definition of abstraction as difference through her friend Theodoros Stamos's notion of camp and helps to explain her admiration of Barnett Newman despite her refusal to devote her gallery exclusively to his narrower version of significant abstraction.

  9. Crafting glass vessels: current research on the ancient glass collections in the Freer Gallery of Art, Washington, D.C.

    Science.gov (United States)

    Nagel, Alexander; McCarthy, Blythe; Bowe, Stacy

    Our knowledge of glass production in ancient Egypt has been well augmented by the publication of recently excavated materials and glass workshops, but also by more recent materials analysis, and experiments of modern glass-makers attempting to reconstruct the production process of thin-walled coreformed glass vessels. From the mounting of a prefabricated core to the final glass product our understanding of this profession has much improved. The small but well preserved glass collection of the Freer Gallery of Art in Washington, D.C. is a valid tool for examining and studying the technology and production of ancient Egyptian core formed glass vessels. Charles Lang Freer (1854-1919) acquired most of the material from Giovanni Dattari in Cairo in 1909. Previously the glass had received only limited discussion, suggesting that most of these vessels were produced in the 18th Dynasty in the 15th and 14th centuries BCE, while others date from the Hellenistic period and later. In an ongoing project we conducted computed radiography in conjunction with qualitative x-ray fluorescence analysis on a selected group of vessels to understand further aspects of the ancient production process. This paper will provide an overview of our recent research and present our data-gathering process and preliminary results. How can the examinations of core formed glass vessels in the Freer Gallery contribute to our understanding of ancient glass production and technology? By focusing on new ways of looking at old assumptions using the Freer Gallery glass collections, we hope to increase understanding of the challenges of the production process of core-vessel technology as represented by these vessels.

  10. Mechanical properties and related substructure of TiNi shape memory alloys

    International Nuclear Information System (INIS)

    Filip, P.; Kneissl, A.C.

    1995-01-01

    The mechanical properties of binary near equiatomic TiNi shape memory alloys were investigated after different types of mechanical and heat treatments. The changes of deformation behaviour are explained on the basis of substructure differences after work hardening. The ''elastic moduli'' of both the high-temperature phase B2 and the martensite B19' as well as the ''easy stage of deformation'' are dependent on the work hardening intensity and these changes are related to the mobility of B2/B19' interfaces. The martensite changes its morphology after work hardening. In contrast to a twinned martensite, typical for annealed alloys, the internally slipped martensite was detected after work hardening. (orig.)

  11. Tiny timekeepers witnessing high-rate exhumation processes.

    Science.gov (United States)

    Zhong, Xin; Moulas, Evangelos; Tajčmanová, Lucie

    2018-02-02

    Tectonic forces and surface erosion lead to the exhumation of rocks from the Earth's interior. Those rocks can be characterized by many variables including peak pressure and temperature, composition and exhumation duration. Among them, the duration of exhumation in different geological settings can vary by more than ten orders of magnitude (from hours to billion years). Constraining the duration is critical and often challenging in geological studies particularly for rapid magma ascent. Here, we show that the time information can be reconstructed using a simple combination of laser Raman spectroscopic data from mineral inclusions with mechanical solutions for viscous relaxation of the host. The application of our model to several representative geological settings yields best results for short events such as kimberlite magma ascent (less than ~4,500 hours) and a decompression lasting up to ~17 million years for high-pressure metamorphic rocks. This is the first precise time information obtained from direct microstructural observations applying a purely mechanical perspective. We show an unprecedented geological value of tiny mineral inclusions as timekeepers that contributes to a better understanding on the large-scale tectonic history and thus has significant implications for a new generation of geodynamic models.

  12. SCADA SYSTEM SIMULATION USING THE TINY TIGER 2 DEVELOPMENT BOARD

    Directory of Open Access Journals (Sweden)

    AGAPE C.P.

    2015-12-01

    Full Text Available This paper presents a new design for a surveillance and control system of a medium voltage cell. The accent is on the acquisition of information of the consumer’s state, the instantaneous current consumption, power and voltage apparent to the consumer. The proposed design is based on Wilke Technology development board at its basis being a Tiny-tiger 2 Multitasking Microcontroller. This computer has 2 MByte or 4 MByte Flash for programming, and 1 MByte SRAM with backup input for data. On the software’s behalf we managed to create a Delphi Interface which communicates with the serial port on the development board. The interface takes information about the consumer and its capacity to load with voltage.

  13. Monitoring the Excavation Damaged Zone in Opalinus clay by three dimensional reconstruction of the electrical resistivity in the Mont Terri gallery G-04

    Science.gov (United States)

    Lesparre, N.; Adler, A.; Nicollin, F.; Gibert, D.; Nussbaum, C.

    2012-04-01

    The characteristics of opalinus clay have been studied in the last years for its capacity to retain radionuclide transport as a low permeable rock. This formation presents thereby suitable properties for hosting repository sites of radioactive waste. The Mont Terri underground rock laboratory (Switzerland) has been excavated in opalinus clay layer in order to develop experiences improving the knowledge on the physico-chemical properties of the rock. The study of electrical properties furnishes information on the rock structure, its anisotropy and the changes of these properties with time (Nicollin et al., 2010 ; Thovert et al., 2011). Here the three dimensional reconstruction of the electrical resistivity aims at monitoring the temporal evolution of the excavation damaged zone. Three rings of electrodes have been set-up around the gallery and voltage is measured between two electrodes while a current is injected between two others (Gibert et al., 2006). Measurements have been achieved from July 2004 until April 2008 before, during and after the excavation of the gallery 04. In this study we develop a computational approach to reconstruct three dimensional images of the resistivity in the vicinity of the electrodes. A finite element model is used to represent the complex geometry of the gallery. The measurements inferred from a given resistivity distribution are estimated using the software EIDORS (Adler and Lionheart, 2006), this constitutes the forward problem. The reconstruction of the media resistivity is then implemented by fitting the estimated to the measured data, via the resolution of an inverse problem. The parameters of this inverse problem are defined by mapping the forward problem elements into a coarser mesh. This allows to reduce drastically the number of unknowns and so increases the robustness of the inversion. The inversion is executed with the conjugate gradient method regularised by an analysis of the Jacobian singular values. The results show an

  14. Australian doctors and the visual arts. Part 2. Doctors as collectors, donors, gallery supporters and writers in New South Wales.

    Science.gov (United States)

    Hamilton, D G

    1986-04-28

    The contribution of doctors to the visual arts if being discussed in a series of six articles. The first article dealt with doctor-artists in new South Wales. In this, the second, doctors are discussed as collectors, donors, gallery supporters and writers in this State.

  15. THE BOSS EMISSION-LINE LENS SURVEY. IV. SMOOTH LENS MODELS FOR THE BELLS GALLERY SAMPLE

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Yiping [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China); Bolton, Adam S.; Montero-Dorta, Antonio D.; Cornachione, Matthew A.; Zheng, Zheng; Brownstein, Joel R. [Department of Physics and Astronomy, University of Utah, 115 South 1400 East, Salt Lake City, UT 84112 (United States); Mao, Shude [Physics Department and Tsinghua Centre for Astrophysics, Tsinghua University, Beijing 100084 (China); Kochanek, Christopher S. [Department of Astronomy and Center for Cosmology and Astroparticle Physics, Ohio State University, Columbus, OH 43210 (United States); Pérez-Fournon, Ismael; Marques-Chaves, Rui [Instituto de Astrofísica de Canarias, C/Vía Láctea, s/n, E-38205 San Cristóbal de La Laguna, Tenerife (Spain); Oguri, Masamune [Research Center for the Early Universe, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Ménard, Brice, E-mail: yiping.shu@nao.cas.cn [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States)

    2016-12-20

    We present Hubble Space Telescope F606W-band imaging observations of 21 galaxy-Ly α emitter lens candidates in the Baryon Oscillation Spectroscopic Survey Emission-Line Lens Survey (BELLS) for the GALaxy-Ly α EmitteR sYstems (BELLS GALLERY) survey. Seventeen systems are confirmed to be definite lenses with unambiguous evidence of multiple imaging. The lenses are primarily massive early-type galaxies (ETGs) at redshifts of approximately 0.55, while the lensed sources are Ly α emitters (LAEs) at redshifts from two to three. Although most of the lens systems are well fit by smooth lens models consisting of singular isothermal ellipsoids in an external shear field, a thorough exploration of dark substructures in the lens galaxies is required. The Einstein radii of the BELLS GALLERY lenses are, on average, 60% larger than those of the BELLS lenses because of the much higher source redshifts. This will allow for a detailed investigation of the radius evolution of the mass profile in ETGs. With the aid of the average ∼13× lensing magnification, the LAEs are frequently resolved into individual star-forming knots with a wide range of properties. They have characteristic sizes from less than 100 pc to several kiloparsecs, rest-frame far-UV apparent AB magnitudes from 29.6 to 24.2, and typical projected separations of 500 pc to 2 kpc.

  16. Post-occupancy evaluation of a restored industrial building: A contemporary art and design gallery in Mexico

    Directory of Open Access Journals (Sweden)

    J. Mundo-Hernández

    2015-12-01

    Full Text Available This paper presents the results obtained from a post-occupancy evaluation (POE study conducted in an old fabric building called “La Violeta”. This structure has been recently converted into a contemporary art gallery. La Violeta is located in Puebla City, Mexico. The building dates from the beginning of the 19th century; it was built and used as a textile factory until the first decades of the 20th century. This POE study aims to assess the new use of the building from the users׳ point of view. Methodology involves historical research of the building, analysis of the conversion strategy, walkthrough investigation, and a user survey. Questions regarding the re-utilization strategy used in the building and its current use are included in the survey, such as “How do people perceive the space regarding its functionality, accessibility, and comfort?” Although the re-utilization process destroyed several historic elements, the re-use of old industrial spaces that otherwise would be obsolete and disused seems pertinent. Developing small renovation projects as part of an integral and wider project seems feasible. Users perceive the building as comfortable but not properly advertised as an art gallery, and its location is difficult to find.

  17. Adult Education for Social and Environmental Change in Contemporary Public Art Galleries and Museums in Canada, Scotland and England

    Science.gov (United States)

    Clover, Darlene E.

    2015-01-01

    Historically, pubic art galleries and museums have a well-deserved reputation for elitism, colonialism and exclusion and they are, therefore, frequently omitted from the discourse of adult education. However, the escalating social, cultural and ecological problems of this new century have placed pressure on these public institutions to change and…

  18. Effect of hydrogen on transformation characteristics and deformation behavior in a Ti-Ni shape memory alloy

    International Nuclear Information System (INIS)

    Hoshiya, Taiji; Ando, Hiroei; Den, Shoji; Katsuta, Hiroshi.

    1992-01-01

    Transformation characteristics and deformation behavior of hydrogenated Ti-50.5 at% Ni alloys, which were occluded in a low pressure range of hydrogen between 1.1 and 78.5 kPa, have been studied by electrical resistivity measurement, tensile test, X-ray diffraction analysis and microstructural observation. M S temperature of the Ti-Ni alloys decreased with an increase in hydrogen content. This corresponds to the stabilization of the parent phase during cooling, which was confirmed by X-ray diffraction: The suppression effect of hydrogen takes place on the martensitic transformation. Critical stress for slip deformation of hydrogenated Ti-Ni alloys changed with hydrogen content and thus hydrogen had a major influence on deformation behavior of those alloys. With hydrogen contents above 0.032 mol%, hardening was distinguished from softening which was pronounced in the contents from 0 to 0.032 mol% H. Hydrides were formed in hydrogen contents over 1.9 mol%. The hydride formation results in the reorientation in variants of the R phase and increase in the lattice strains of the parent phase. (author)

  19. Use of beach galleries as an intake for future seawater desalination facilities in Florida and globally similar areas

    KAUST Repository

    Missimer, Thomas M.

    2013-06-17

    Desalination of seawater using the reverse osmosis process can be made less costly by the use of subsurface intake systems. Use of conventional open-ocean intakes requires the addition of a number of pretreatment processes to protect the primary RO process. Despite using the best designs possible for the pretreatment, seawater RO membranes tend to biofoul because of the naturally-occurring organic material and small bacteria present in seawater. These materials are not completely removed by the pretreatment system and they pass through the cartridge filters into the membranes, thereby causing frequent and expensive cleaning of the membranes. Quality of the raw water can be greatly improved by the use of subsurface intakes which can substantially reduce the overall treatment cost. There are a number of possible subsurface designs that can be used including conventional vertical wells, horizontal wells, collector wells, beach galleries, and seabed filters. The key selection criteria for the type of subsurface intake most suited and most cost-effective for a site are based on the required volume of raw water and the local geology. The active shorelines of Florida are very well-suited for the development of beach gallery intake systems. These systems are installed beneath the active beach between the high and low tide zones of the beach. Since they are constructed with a depth to the screens between 3 and 5 m, they cannot be observed at surface and persons using the beach would be unaware of their existence. These galleries are simple to construct and they tend not to clog because the active wave action within the intertidal zone provides mechanical energy that continuously cleans the filter face. They also have other advantages, including: the water quality is seawater unaffected by substances present in freshwater aquifers occurring landward of the shoreline, the salinity of the water is generally constant, and there are no impacts on water users located inland from

  20. Technical feasibility of a seabed gallery seawater intake at Ras Abu Ali Island, Arabian Gulf, Saudi Arabia

    KAUST Repository

    Rachman, Rinaldi

    2014-07-23

    (less than 1%) with porosity ranging between 0.29 and 0.41 and hydraulic conductivities up to 22.5 m3/d. It was determined that seabed gallery development is suitable at this location. Preliminary design for a seabed gallery filter was developed using a series of cells. Each gallery cell represents a unit that can be simply duplicated to meet the overall intake capacity requirement. Each gallery cell is designed to have minimum 8 m/d infiltration rate through five layers of engineered sand and gravel. The total thickness of the filter bed is 4.5 m (2 m top layer). The dimensions of the proposed cells are 100 × 30 m and each cell will conservatively provide 24,000 m3/d of filtered water. The design is flexible to meet the required capacity. For example, a SWRO desalination plant which produces 54,000 m3/d product water from 38,000 mg/L salinity seawater at a 45% conversion rate will require a minimum of 6 cells using the preliminary design. © 2014 © 2014 Balaban Desalination Publications. All rights reserved.

  1. Rapid thermal annealing of Ti-rich TiNi thin films: A new approach to fabricate patterned shape memory thin films

    International Nuclear Information System (INIS)

    Motemani, Y.; Tan, M.J.; White, T.J.; Huang, W.M.

    2011-01-01

    This paper reports the rapid thermal annealing (RTA) of Ti-rich TiNi thin films, synthesized by the co-sputtering of TiNi and Ti targets. Long-range order of aperiodic alloy could be achieved in a few seconds with the optimum temperature of 773 K. Longer annealing (773 K/240 s), transformed the film to a poorly ordered vitreous phase, suggesting a novel method for solid state amorphization. Reitveld refinement analyses showed significant differences in structural parameters of the films crystallized by rapid and conventional thermal annealing. Dependence of the elastic modulus on the valence electron density (VED) of the crystallized films was studied. It is suggested that RTA provides a new approach to fabricate patterned shape memory thin films.

  2. Technical feasibility of a seabed gallery system for SWRO facilities at Shoaiba, Saudi Arabia, and regions with similar geology

    KAUST Repository

    Rodri­guez, Luis R. Lujan

    2013-09-02

    Subsurface intakes can be used as part of the pretreatment system for seawater reverse osmosis facilities. Wells of various designs and galleries are being used for intakes at many sites globally to reduce pretreatment costs, chemical usage, biofouling potential, and environmental impacts (entrainment and impingement). The goal of using a subsurface intake is to reduce or replace conventional pretreatment processes. A field and laboratory investigation was undertaken to assess the feasibility of developing a seabed gallery intake offshore near the Shoaiba seawater RO (SWRO) plant site (150,000 m3/d treatment capacity) that could be used to replace the current intake used for only the RO capacity. A survey of the beach and offshore area was made and 51 sediment samples were collected from the seabed for laboratory analysis of grain size distribution, porosity, and hydraulic conductivity. Field observations showed that the marine bottom has a low slope from the shoreline seaward a distance of about 100 m to a depth of about 1.0 m before it steepens to a depth of over 2 m at 150 m from shore. The site has a relativity thin cover of unlithified carbonate sands, 2-5 cm thick, sitting on a soft coralline limestone of Pleistocene age. The sediments investigated were found to be clean carbonate or slightly muddy carbonate sands with mean grain diameters ranging mostly between 0.25 and 0.5 mm. Most of the area investigated contained a mud percentage between 0 and 5%. The measured porosity values range between 0.33 and 0.45 and measured hydraulic conductivity values from about 1.6 to 79.5 m/d with 64.6 m/d being the maximum offshore value. A preliminary design was developed to meet the full operational capacity of the Shoaiba SWRO treatment plant which would require 375,000 m3/d of raw water to produce 150,000 m3/d of permeate (40% conversion assumed for Red Sea water with a TDS of 41,000 mg/L). The design of the RO plant uses 10 trains to produce the 150,000 m3/d of product

  3. Absorptive lasing mode suppression in ZnO nano- and microcavities

    Energy Technology Data Exchange (ETDEWEB)

    Wille, M.; Michalsky, T.; Krüger, E.; Grundmann, M.; Schmidt-Grund, R. [Universität Leipzig, Institut für Experimentelle Physik II, Linnéstraße 5, 04103 Leipzig (Germany)

    2016-08-08

    We conclusively explain the different lasing mode energies in ZnO nano- and microcavities observed by us and reported in literature. The limited penetration depth of usually used excitation lasers results in an inhomogeneous spatial gain region depending on the structure size and geometry. Hence, weakly or even nonexcited areas remain present after excitation, where modes are instantaneously suppressed by excitonic absorption. We compare the effects for ZnO microwires, nanowires, and tetrapod-like structures at room temperature and demonstrate that the corresponding mode selective effect is most pronounced for whispering-gallery modes in microwires with a hexagonal cross section. Furthermore, the absorptive lasing mode suppression will be demonstrated by correlating the spot size of the excitation laser and the lasing mode characteristic of a single ZnO nanowire.

  4. Competitive excitation and osmotic-pressure-mediated control of lasing modes in cholesteric liquid crystal microshells

    Science.gov (United States)

    Lin, Ya-Li; Gong, Ling-Li; Che, Kai-Jun; Li, Sen-Sen; Chu, Cheng-Xu; Cai, Zhi-Ping; Yang, Chaoyong James; Chen, Lu-Jian

    2017-05-01

    We examined the end-pumped lasing behaviors of dye doped cholesteric liquid crystal (DDCLC) microshells which were fabricated by glass capillary microfluidics. Several kinds of mode resonances, including distributed feedback, Fabry-Pérot (FP), and whispering gallery (WG) modes, can be robustly constructed in each individual DDCLC microshell by varying the beam diameter, namely, tuning the DDCLC gain area. The FP and WG modes were further confirmed experimentally, and the corresponding lasing mechanisms are clearly revealed from the unique material characteristics of DDCLC and the geometrical structure of the microshell. Additionally, we demonstrated that the osmotic pressure can be used to shrink/expand the microshell, productively tuning the excitation of lasing modes in a controlled manner. We wish our findings can provide a new insight into the design of DDCLC microlasers with tunable optical properties.

  5. Optical Microbubble Resonators with High Refractive Index Inner Coating for Bio-Sensing Applications: An Analytical Approach

    Directory of Open Access Journals (Sweden)

    Andrea Barucci

    2016-11-01

    Full Text Available The design of Whispering Gallery Mode Resonators (WGMRs used as an optical transducer for biosensing represents the first and crucial step towards the optimization of the final device performance in terms of sensitivity and Limit of Detection (LoD. Here, we propose an analytical method for the design of an optical microbubble resonator (OMBR-based biosensor. In order to enhance the OMBR sensing performance, we consider a polymeric layer of high refractive index as an inner coating for the OMBR. The effect of this layer and other optical/geometrical parameters on the mode field distribution, sensitivity and LoD of the OMBR is assessed and discussed, both for transverse electric (TE and transverse magnetic (TM polarization. The obtained results do provide physical insights for the development of OMBR-based biosensor.

  6. An experimental study on the erosion behavior of pseudoelastic TiNi alloy in dry sand and in aggressive media

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, T.; Li, D.Y. [Alberta Univ., Edmonton, AB (Canada). Dept. of Chemical Engineering

    2000-11-30

    The corrosive erosion behavior of Ti-51at.%Ni alloy under different erosion conditions was studied and compared to that of 304 stainless steel. Erosion tests were performed in a slurry-pot tester with dry sand, 3.5% NaCl slurry and 0.1 moll{sup -1} H{sub 2}SO{sub 4} slurry containing 30% silica sand, respectively. Synergistic effects of corrosion and erosion were studied in steady corrosion, polarization, dry sand erosion and micro-wear experiments. An electrochemical-scratching test characterized the failure and recovery of the passive film formed on TiNi alloy in 3.5% NaCl and 0.1 mol l{sup -1} H{sub 2}SO{sub 4} solutions, respectively. In both dry sand and the corrosive media, the TiNi alloy exhibited considerably greater erosion resistance than 304 stainless steel. (orig.)

  7. In situ stress measurements at 250m gallery off the ventilation shaft

    International Nuclear Information System (INIS)

    Nakamura, Takahiro; Sanada, Hiroyuki; Sugita, Yutaka; Kato, Harumi

    2011-06-01

    From FY2000 to FY2005, JAEA had been making research at ground surface of Horonobe town for repository of high-level radioactive waste. During this period, geological investigation, hydrogeology investigation, rock mechanics investigation, geochemical investigation using boreholes were carried out in Hokushin area which is about 3kmx3km in surface area of Horonobe town in order to construct a geological environment model and to confirm the methodology for safety assessment. Now the research program proceeds to the next stage where the underground drifts and shafts are under construction. In the underground rock mass, in situ stress is the sum of tectonic stress as well as overlying stress due to gravity. In situ stresses enter into excavation design and are required in order to predict the response of rock masses to the disturbance associated with those structures. For these reasons, JAEA has carried out in situ stress measurements using vertical boreholes drilled from ground surface to evaluate the state of horizontal stress in the area. In the research during the underground construction, comparison between the stress measurements carried out at surface and at underground is conducted. And if inconsistency between these two measurements is found, the state of stress will be updated based on more reliable information. In order to study the 3D in situ state of stress around Horonobe Underground Research Laboratory, hydraulic fracturing tests and stress relief method (Conical-ended borehole method) were conducted at the 250m gallery located near the bottom of the ventilation shaft. Three 20.0m long boreholes, 09-V250-M01(slightly upwards), 09-V250-M02(slightly upwards) and 09-V250-M03(vertical), were drilled from the gallery using 76mm diameter bit. The results of the measurements are summarized as follows: (1) Hydraulic fracturing technique. Hydraulic fracturing technique using the test equipment with sufficiently small compliance was carried out in the three

  8. Technical feasibility of using gallery intakes for seawater RO facilities, northern Red Sea coast of Saudi Arabia: The King Abdullah Economic City site

    KAUST Repository

    Dehwah, Abdullah; Missimer, Thomas M.

    2013-01-01

    intakes. One of the potentially favorable sites for a seabed gallery system was located in the nearshore area at King Abdullah Economic City (KAEC). Detailed investigation of the site hydrology (tides and wave action), sediment grain size characteristics

  9. Passion Trumps Pay: A Study of the Future Skills Requirements of Information Professionals in Galleries, Libraries, Archives and Museums in Australia

    Science.gov (United States)

    Howard, Katherine; Partridge, Helen; Hughes, Hilary; Oliver, Gillian

    2016-01-01

    Introduction: This paper explores the current and future skills and knowledge requirements of contemporary information professionals in a converged gallery, library, archive and museum sector (also referred to as the GLAM sector) in Australia. This research forms part of a larger study that investigated the education needs of information…

  10. Preliminary study of infiltration gallery for water treatment towards Universal Access 2019 in Indonesia

    Directory of Open Access Journals (Sweden)

    Maritha Nilam Kusuma

    2018-06-01

    Full Text Available Infiltration gallery is a method of water treatment through soil filtration. The mechanism is the filtering or absorption of contaminants in the river that flows through the soil. This method uses soil to remove contaminants. This method has three kinds of screening processes, ie physically, chemically and biologically. This process depends on moisture content, temperature, porosity, specific gravity, the saturated degree and hydraulic conductivity in the soil. Now a days, the cost of clean water production in the province of East Java, Indonesia requires a lot of cost, because the consumption of coagulant is very high; It is necessary to have a preliminary processing that helps the performance of water treatment in East Java, Indonesia. Natural water purification method using soil called infiltration gallery can be one solution in processing river water or as preliminary processing for water treatment in East Java. The purpose of this research is to know soil characteristics in soil samples in each region and its ability to removel TSS and Total Coliform. The second objective is to find good soil composition for removel TSS and total Coliform. The location of soil sampling is in Surabaya, Lumajang, Bangkalan, Mojokerto, Sidoarjo and Gresik, East Java province, Indonesia. The method of analysis used gravimetry, method 9223 B, the comparison between mass and specific gravity, constant head permeameter and wet grain. The results showed that the soil samples from each region were not able to remove the TSS and total coliform, so that the engineering of soil composition was required. Appropriate soil composition is sand and clay, 85% and 15%, with the percentage of TSS and total coliform removal of 63.50% and 99.67%.

  11. Electrical tomography monitoring of the EDZ during the excavation of the gallery Ga08 in the Mont Terri URL

    International Nuclear Information System (INIS)

    Nicollin, Florence; Gibert, Dominique; Lesparre, Nolwenn; Nussbaum, Christophe

    2010-01-01

    Document available in extended abstract form only. In the Mont Terri Underground Rock Laboratory, the excavation of the new gallery Ga08 provided a unique opportunity to monitor the excavation damaged zone (EDZ) in the Opalinus clay, at time scales ranging from hours to months. The excavation of the gallery Ga08 has started from the northern end of the URL and has progressed towards the South, ending by the junction with the end of the gallery Ga04. Several geophysical and geochemical methods were performed from the end face of the gallery Ga04, to observe the evolution of the rock mass located in the so-called EZ-G08 section during the progress of the excavation. Thus, electrical resistivity measurements were performed, with electrodes placed both on the Ga04 face and in boreholes perpendicular to the face. These experiments revealed a strong anisotropy of the electrical resistivity of the rock mass, and they allowed to study the temporal evolution of the electrical resistivity in the EDZ. An array of more than 700 electrodes was installed on the rough face according to a square mesh with a mean side of 30 cm. On each line of the mesh, the electrodes were equally spaced every 15 cm. 4 horizontal boreholes, 8 m long and 56 mm in diameter, were equipped with lines of 64 electrodes equally spaced every 5 cm. Finally, 2 groups of 4 boreholes, 1 m long and spaced about 20 cm, were equipped with lines of 16 electrodes equally spaced every 5 cm. Using the electrode array of the face, Wenner profiles were acquired along both the horizontal and the vertical lines, highlighting a strong anisotropy of electrical resistivity since the values depend on the direction in which they are measured. In order to characterize this anisotropy, other measurements were done using the array of the face and the lines of the short boreholes, with the so-called square array configuration where the electrodes are located at the corners of squares with different orientations. On the face

  12. Abundance and frugivory of the toco toucan (Ramphastos toco) in a gallery forest in Brazil's Southern Pantanal

    OpenAIRE

    Ragusa-Netto,J.

    2006-01-01

    Unlike other toucan species, the Toco toucan (Ramphastos toco) - the largest Ramphastidae - usually inhabits dry semi-open areas. This conspicuous canopy frugivore uses a large home range that includes a variety of vegetation types, among which gallery forests are widely cited as important to this species. However, the factors relating to the occurrence of Toco toucans in such habitats are unclear. I studied the abundance of Toco toucans as well as the availability of fleshy fruit in a galler...

  13. Changing Subjects: The Gallery at Cleveland House and the Highland Clearances

    Directory of Open Access Journals (Sweden)

    Anne Nellis Richter

    2016-04-01

    Full Text Available In 1812, a porter named William Cantrill published a small volume of etchings dedicated to his employer, the Marchioness of Stafford. Cantrill characterized his reproductions of a select group of small Netherlandish pictures from the art gallery at the Marchioness’s London residence, Cleveland House, as “first attempts from an untutored hand”, calling attention to his status as a servant and untrained artist. In this article, I examine this idiosyncratic volume in light of the reception of small subject pictures in the early nineteenth century, and also within the context of the Marchioness of Stafford’s involvement in the Highland Clearances. At a moment when the Marchioness and her husband were under scrutiny for the heavy-handed tactics used against their Scottish tenants, this book used the category of genre painting to smooth over the gaps between landowner and tenant that the Clearances had made evident.

  14. Floristic survey of the herbaceous-shrub layer of a gallery forest in Alto Paraíso de Goiás - GO, Brazil

    Directory of Open Access Journals (Sweden)

    Eduardo Chaves

    2012-10-01

    Full Text Available Flowering species of the herbaceous and shrubby layer were sampled in a gallery forest at Portal da Chapada, Alto Paraíso de Goiás-GO in the Chapada dos Veadeiros during 12 months growing within 4.5 meters on either side of a raised pathway 2.4 Km long. The collections were included to University of Brasilia Herbarium (UB. A total of 138 species (103 genera and 40 families were recorded; the most species-rich families were Asteraceae (22, Poaceae (14, Rubiaceae (12, Fabaceae (11 and Melastomataceae (7. The richest family in number of genera was Asteraceae (19, followed by Poaceae (8, Fabaceae (8 and Rubiaceae (7. The results showed a meaningful increase in the Chapada dos Veadeiros flora, especially considering the herbaceous-shrubby layer of the gallery forests (223.6%. Despite the richness of the flora, the number of endemics species in the Goiás State was only 1.5%.

  15. Shape memory and pseudoelastic properties of Fe-Mn-Si and Ti-Ni based alloys

    International Nuclear Information System (INIS)

    Guenin, G.

    1997-01-01

    The aim of this presentation is to analyse and discuss some recent advances in shape memory and pseudoelastic properties of different alloys. Experimental work in connection with theoretical ones will be reviewed. The first part is devoted to the microstructural origin of shape memory properties of Fe-Mn-Si based alloys (γ-ε transformation); the second part is a synthetic analysis of the effects of thermomechanical treatments on shape memory and pseudoelastic effects in Ti-Ni alloys, with some focus on the behaviour of the R phase introduced. (orig.)

  16. Purple Salt and Tiny Drops of Water in Meteorites

    Science.gov (United States)

    Taylor, G. J.

    1999-12-01

    Some meteorites, especially those called carbonaceous chondrites, have been greatly affected by reaction with water on the asteroids in which they formed. These reactions, which took place during the first 10 million years of the Solar System's history, formed assorted water-bearing minerals, but nobody has found any of the water that caused the alteration. Nobody, that is, until now. Michael Zolensky and team of scientists from the Johnson Space Center in Houston and Virginia Tech (Blacksburg, Virginia) discovered strikingly purple sodium chloride (table salt) crystals in two meteorites. The salt contains tiny droplets of salt water (with some other elements dissolved in it). The salt is as old as the Solar System, so the water trapped inside the salt is also ancient. It might give us clues to the nature of the water that so pervasively altered carbonaceous chondrites and formed oceans on Europa and perhaps other icy satellites. However, how the salt got into the two meteorites and how it trapped the water remains a mystery - at least for now.

  17. High-spatial-resolution electron density measurement by Langmuir probe for multi-point observations using tiny spacecraft

    Science.gov (United States)

    Hoang, H.; Røed, K.; Bekkeng, T. A.; Trondsen, E.; Clausen, L. B. N.; Miloch, W. J.; Moen, J. I.

    2017-11-01

    A method for evaluating electron density using a single fixed-bias Langmuir probe is presented. The technique allows for high-spatio-temporal resolution electron density measurements, which can be effectively carried out by tiny spacecraft for multi-point observations in the ionosphere. The results are compared with the multi-needle Langmuir probe system, which is a scientific instrument developed at the University of Oslo comprising four fixed-bias cylindrical probes that allow small-scale plasma density structures to be characterized in the ionosphere. The technique proposed in this paper can comply with the requirements of future small-sized spacecraft, where the cost-effectiveness, limited space available on the craft, low power consumption and capacity for data-links need to be addressed. The first experimental results in both the plasma laboratory and space confirm the efficiency of the new approach. Moreover, detailed analyses on two challenging issues when deploying the DC Langmuir probe on a tiny spacecraft, which are the limited conductive area of the spacecraft and probe surface contamination, are presented in the paper. It is demonstrated that the limited conductive area, depending on applications, can either be of no concern for the experiment or can be resolved by mitigation methods. Surface contamination has a small impact on the performance of the developed probe.

  18. Mode coupling in hybrid square-rectangular lasers for single mode operation

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Xiu-Wen; Huang, Yong-Zhen, E-mail: yzhuang@semi.ac.cn; Yang, Yue-De; Xiao, Jin-Long; Weng, Hai-Zhong; Xiao, Zhi-Xiong [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors and University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100083 (China)

    2016-08-15

    Mode coupling between a square microcavity and a Fabry-Pérot (FP) cavity is proposed and demonstrated for realizing single mode lasers. The modulations of the mode Q factor as simulation results are observed and single mode operation is obtained with a side mode suppression ratio of 46 dB and a single mode fiber coupling loss of 3.2 dB for an AlGaInAs/InP hybrid laser as a 300-μm-length and 1.5-μm-wide FP cavity connected to a vertex of a 10-μm-side square microcavity. Furthermore, tunable single mode operation is demonstrated with a continuous wavelength tuning range over 10 nm. The simple hybrid structure may shed light on practical applications of whispering-gallery mode microcavities in large-scale photonic integrated circuits and optical communication and interconnection.

  19. Thermally controlled coupling of a rolled-up microtube integrated with a waveguide on a silicon electronic-photonic integrated circuit.

    Science.gov (United States)

    Zhong, Qiuhang; Tian, Zhaobing; Veerasubramanian, Venkat; Dastjerdi, M Hadi Tavakoli; Mi, Zetian; Plant, David V

    2014-05-01

    We report on the first experimental demonstration of the thermal control of coupling strength between a rolled-up microtube and a waveguide on a silicon electronic-photonic integrated circuit. The microtubes are fabricated by selectively releasing a coherently strained GaAs/InGaAs heterostructure bilayer. The fabricated microtubes are then integrated with silicon waveguides using an abruptly tapered fiber probe. By tuning the gap between the microtube and the waveguide using localized heaters, the microtube-waveguide evanescent coupling is effectively controlled. With heating, the extinction ratio of a microtube whispering-gallery mode changes over an 18 dB range, while the resonant wavelength remains approximately unchanged. Utilizing this dynamic thermal tuning effect, we realize coupling modulation of the microtube integrated with the silicon waveguide at 2 kHz with a heater voltage swing of 0-6 V.

  20. Fiber pigtailed thin wall capillary coupler for excitation of microsphere WGM resonator.

    Science.gov (United States)

    Wang, Hanzheng; Lan, Xinwei; Huang, Jie; Yuan, Lei; Kim, Cheol-Woon; Xiao, Hai

    2013-07-01

    In this paper, we demonstrate a fiber pigtailed thin wall capillary coupler for excitation of Whispering Gallery Modes (WGMs) of microsphere resonators. The coupler is made by fusion-splicing an optical fiber with a capillary tube and consequently etching the capillary wall to a thickness of a few microns. Light is coupled through the peripheral contact between inserted microsphere and the etched capillary wall. The coupling efficiency as a function of the wall thickness was studied experimentally. WGM resonance with a Q-factor of 1.14 × 10(4) was observed using a borosilicate glass microsphere with a diameter of 71 μm. The coupler operates in the reflection mode and provides a robust mechanical support to the microsphere resonator. It is expected that the new coupler may find broad applications in sensors, optical filters and lasers.

  1. Role of edge inclination in an optical microdisk resonator for label-free sensing.

    Science.gov (United States)

    Gandolfi, Davide; Ramiro-Manzano, Fernando; Rebollo, Francisco Javier Aparicio; Ghulinyan, Mher; Pucker, Georg; Pavesi, Lorenzo

    2015-02-26

    In this paper, we report on the measurement and modeling of enhanced optical refractometric sensors based on whispering gallery modes. The devices under test are optical microresonators made of silicon nitride on silicon oxide, which differ in their sidewall inclination angle. In our approach, these microresonators are vertically coupled to a buried waveguide with the aim of creating integrated and cost-effective devices. Device modeling shows that the optimization of the device is a delicate balance of the resonance quality factor and evanescent field overlap with the surrounding environment to analyze. By numerical simulations, we show that the microdisk thickness is critical to yield a high figure of merit for the sensor and that edge inclination should be kept as high as possible. We also show that bulk-sensing figures of merit as high as 1600 RIU(-1) (refractive index unit) are feasible.

  2. Ultraviolet lasing behavior in ZnO optical microcavities

    Directory of Open Access Journals (Sweden)

    Hongxing Dong

    2017-12-01

    Full Text Available Zinc oxide (ZnO optical microcavity modulated UV lasers have been attracting a wide range of research interests. As one of the most important materials in developing high quality microcavity and efficient UV–visible optoelectronic devices due to its wide band gap (3.37 eV and large exciton binding energy (∼60 meV. In this review, we summarized the latest development of ZnO optical cavity based microlasers, mainly including Fabry-Perot mode lasers and whispering gallery mode lasers. The synthesis and optical studies of ZnO optical microcavities with different morphologies were discussed in detail. Finally, we also consider that the research focus in the near future would include new nanotechnology and physical effects, such as nano/micro fabrication, surface plasmon enhancement, and quantum dot coupling, which may result in new and interesting physical phenomena.

  3. Conformal Organohalide Perovskites Enable Lasing on Spherical Resonators

    KAUST Repository

    Sutherland, Brandon R.

    2014-10-28

    © 2014 American Chemical Society. Conformal integration of semiconductor gain media is broadly important in on-chip optical communication technology. Here we deploy atomic layer deposition to create conformally deposited organohalide perovskites-an attractive semiconducting gain medium-with the goal of achieving coherent light emission on spherical optical cavities. We demonstrate the high quality of perovskite gain media fabricated with this method, achieving optical gain in the nanosecond pulse regime with a threshold for amplified spontaneous emission of 65 ± 8 μJ cm-2. Through variable stripe length measurements, we report a net modal gain of 125 ± 22 cm-1 and a gain bandwidth of 50 ± 14 meV. Leveraging the high quality of the gain medium, we conformally coat silica microspheres with perovskite to form whispering gallery mode optical cavities and achieve lasing.

  4. Robust label-free biosensing using microdisk laser arrays with on-chip references.

    Science.gov (United States)

    Wondimu, S F; Hippler, M; Hussal, C; Hofmann, A; Krämmer, S; Lahann, J; Kalt, H; Freude, W; Koos, C

    2018-02-05

    Whispering-gallery mode (WGM) microdisk lasers show great potential for highly sensitive label-free detection in large-scale sensor arrays. However, when used in practical applications under normal ambient conditions, these devices suffer from temperature fluctuations and photobleaching. Here we demonstrate that these challenges can be overcome by a novel referencing scheme that allows for simultaneous compensation of temperature drift and photobleaching. The technique relies on reference structures protected by locally dispensed passivation materials, and can be scaled to extended arrays of hundreds of devices. We prove the viability of the concept in a series of experiments, demonstrating robust and sensitive label-free detection over a wide range of constant or continuously varying temperatures. To the best of our knowledge, these measurements represent the first demonstration of biosensing in active WGM devices with simultaneous compensation of both photobleaching and temperature drift.

  5. Tiny optical fiber temperature sensor based on temperature-dependent refractive index of zinc telluride film

    Science.gov (United States)

    Bian, Qiang; Song, Zhangqi; Song, Dongyu; Zhang, Xueliang; Li, Bingsheng; Yu, Yang; Chen, Yuzhong

    2018-03-01

    The temperature-dependent refractive index of zinc telluride film can be used to develop a tiny, low cost and film-coated optical fiber temperature sensor. Pulse reference-based compensation technique is used to largely reduce the background noise which makes it possible to detect the minor reflectivity change of the film in different temperatures. The temperature sensitivity is 0.0034dB/° and the background noise is measured to be 0.0005dB, so the resolution can achieve 0.2°.

  6. Convergence in anisotropic conditions: gallery behaviour in the Callovo-Oxfordian clayey layer in North-Eastern France

    International Nuclear Information System (INIS)

    Blanco Martin, L.; Hadj-Hassen, F.; Philippe, J.C.; Boidy, E.; Colombet, G.; Armand, G.

    2010-01-01

    Document available in extended abstract form only. Coyne et Bellier (Tractebel Engineering) has been supplying geotechnical services to Andra since 1994 regarding the feasibility for developing a repository for radioactive waste in a 490 m deep clayey formation at the Meuse/Haute-Marne site. Armines/Mines-ParisTech (French engineering school) has been an Andra scientific partner for several years due to its expertise in rock creep behaviour as well as in mining technologies. Throughout the different works carried out for Andra (especially the studies concerning the enlargement of the underground research laboratory), the behaviour of the Callovo-Oxfordian clayey were computed. These studies are used mainly for predicting the long-term behaviour of this layer. Lemaitre's rheological law (or modified Norton's law) has been used for such purposes. This time-dependent law is able to model the isotropic hardening of an elastic-viscoplastic solid by taking into account a non linear viscosity (γ) which Coyne et Bellier has decided to represent by means of a cone-shaped dash-pot element (stiffness increases during creep, cf. Eric Boidy's PhD). This hypothesis, together with that standing for 'long-term incompressibility' (viscoplastic deformation occurs at constant volume), allows the law be expressed by means of the second invariants of the stress (q) and strain (ε vp ) tensors. The rheological model when the long term behaviour takes place beyond a stress threshold (σ S ) is shown. Modelling works that use this law reproduce well convergence measurements as long as radial stresses around the galleries are isotropic. When the stress field around the gallery is anisotropic, the classic Lemaitre's law no longer fits the convergence measurements. This is the case for the GMR gallery at the main level of the laboratory: the horizontal stress is 1.3 times greater than the vertical stress whilst the average vertical convergence is more than five

  7. An Alternative Millimeter Wave Oscillator using a Dielectric Puck in the Whispering Gallery Mode, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — A majority of millimeter wave based systems used for space exploration, communications and research, require a millimeter wave oscillator. These oscillators have...

  8. Tikutõmbeid kottpimedas galeriis = Striking matches in a pitch-dark gallery : [luuletused] / Artur Alliksaar

    Index Scriptorium Estoniae

    Alliksaar, Artur, 1923-1966

    2001-01-01

    Tekst eesti ja inglise k. A. Alliksaare lühibiograafia eesti ja inglise k. lk. 55. Sisu: Tikutõmbeid kottpimedas galeriis = Striking matches in a pitch-dark gallery ; "Olen määratusuur mets..." = "I am infinitely vast forest..." ; "Olen koredate külgedega kalju..." = "I am rough-sided cliff..." ; "Olen meri, millel puudub äär..." = "I am sea that knows no bounds..." ; "Liikumine on niivõrd liitunud mu loomusega..." = "Movement is so much part of me..." ; "Ma ei söandaks öelda, et olen rikas..." = "I would not claim that I am rich..." ; Pöördehetk = Turning point ; Kuigi on nii palju lilli... = Though there are so many flowers ; Antidolorosum

  9. Electrical resistivity imaging survey to detect uncharted mine galleries in the mining district of Linares, Jaén, Spain

    Science.gov (United States)

    Martínez-López, J.; Rey, J.; Dueñas, J.; Hidalgo, C.; Benavente, J.

    2012-02-01

    The scarcity of information about the existence of old mining shafts and galleries in urban areas is an important issue for future urban development. Electrical resistivity tomography is a non-destructive geophysical technique that can detect and characterize such subsurface cavities based on differences in the behaviour of electrical current in the void and in the embedding rock. Here we present a study in which this technique was used to determine the location of old engineered structures around the city of Linares, southern Spain, and to relate these structures to the abandoned deep mines present in the area. Eight electrical resistivity imaging profiles were performed, with a total of 22 808 measurements. Correlations between geoelectrical anomalies allow detection of the depth and the direction of several galleries, as well as the voids that result from mining extraction. Given the depth at which these structures are located (in some cases less than 5 m), they pose an important risk for future construction projects in areas of urban expansion. This technique is shown to be a useful tool for locating areas that pose important urban risks and, by extension, for the decision-making process in territorial planning, especially in areas with a history of deep mining.

  10. Electrical resistivity imaging survey to detect uncharted mine galleries in the mining district of Linares, Jaén, Spain

    International Nuclear Information System (INIS)

    Martínez-López, J; Rey, J; Hidalgo, C; Dueñas, J; Benavente, J

    2012-01-01

    The scarcity of information about the existence of old mining shafts and galleries in urban areas is an important issue for future urban development. Electrical resistivity tomography is a non-destructive geophysical technique that can detect and characterize such subsurface cavities based on differences in the behaviour of electrical current in the void and in the embedding rock. Here we present a study in which this technique was used to determine the location of old engineered structures around the city of Linares, southern Spain, and to relate these structures to the abandoned deep mines present in the area. Eight electrical resistivity imaging profiles were performed, with a total of 22 808 measurements. Correlations between geoelectrical anomalies allow detection of the depth and the direction of several galleries, as well as the voids that result from mining extraction. Given the depth at which these structures are located (in some cases less than 5 m), they pose an important risk for future construction projects in areas of urban expansion. This technique is shown to be a useful tool for locating areas that pose important urban risks and, by extension, for the decision-making process in territorial planning, especially in areas with a history of deep mining

  11. The Strossmayer Gallery in Zagreb in the interwar period: from a utopian project to a renowned institution

    Directory of Open Access Journals (Sweden)

    Ljerka Dulibic

    2016-12-01

    Full Text Available The basis of today’s Strossmayer Gallery’s collection is the bequest of European Old Masters’ paintings collected by Bishop J. J. Strossmayer (1815-1905, with the fundamental desire to enlarge the scope of the Croatian cultural tradition through the appropriation of European elite culture. The meaning and function of the Gallery changed considerably over time. Before WWI, the Strossmayer Gallery was a utopian project in the sense that its mission was not only to fabricate what was seen to be a missing artistic past, but also to create the foundations for a future, native art. After WWI, with the formation of the Kingdom of Serbs, Croats and Slovenes, the national state was, at least in some form, realized, and the Gallery now turned its attention to concrete matters. In this paper, we follow the paths of intensive professionalization of the wide range of activities in the interwar period, retracing not only the history of museum presentation, or the history of Art History and of Art Conservation in Croatia, but also some traces of the general development of the dynamic, intertwined and significant relationship between Art History, Art Conservation and the museum. Il nucleo dell’odierna collezione della Galleria Strossmayer è costituito dal lascito delle opere dei maestri antichi europei raccolti dal vescovo J.J. Strossmayer (1815-1905, il cui scopo fondamentale fu di allargare la tradizione culturale croata con l’appropriazione della cultura elitaria europea. Con il passare del tempo, il signifi cato e la funzione della Galleria cambiò considerevolmente. Prima della Prima guerra mondiale la Galleria Strossmayer fu un progetto utopistico nel senso che la sua missione non era solo di riempire il vuoto visto come il passato artistico mancante, ma anche di creare le fondamenta per una futura arte locale. Dopo la guerra, con la formazione del Regno dei Serbi, Croati e Sloveni, lo stato nazionale fu, almeno in un certo senso, realizzato, e

  12. The Sulphate Effect on Lijiaxia Concrete Dam (China Gallery

    Directory of Open Access Journals (Sweden)

    Xufen Zhu

    2017-01-01

    Full Text Available The concrete degradation is one of the most serious problems for a dam construct during the normal operation, which determines the dam service life. Hence, it is very important to reduce the extent of the dam concrete degradation for the safety of the dam normal operation. Here, Lijiaxia hydroelectric station is taken as an example, and a comprehensive method to assess the sulphate effect on dam gallery is proposed. Eleven samples in total were taken from three difference locations by the drill bore. The microstructural investigations including X-ray fluorescence spectrometry (XRF, X-ray diffraction (XRD, scanning electron microscope (SEM, and energy dispersive spectroscopy (EDS were conducted to assess the sulphate attack and the degradation degree. Meanwhile, the water chemical analysis was applied to reveal the mechanism of concrete degradation. The experimental and analysis results indicate that the concrete degradation degree varies with the location of the samples. The components of the concrete change and the content of SO3 increase dramatically during degradation. Moreover, the mineral facies of the concrete change correspondingly, with the cement paste substituted by the calcite, calcium vitriol, and gypsum. The reinforcement and precaution measures are suggested based on the results of the degradation assessment.

  13. Geotechnical and large numeric studies on direct ultimate disposal of spent fuel elements. Project part 1: Thermal simulation of gallery storage. Final report (8th report)

    International Nuclear Information System (INIS)

    Heusermann, S.; Liedtke, L.; Soennke, J.; Sprado, K.H.; Gloeggler, W.

    1995-01-01

    Short-term tension measurements show that a reduced rock tension level exists in the Thermal Storage Simulation field (TSS). This tension level is markedly lower than the lithostatic rock pressure to be expected in the salt rock. The long-term tension measurements show that tension maxima will develop until early in 1993 in the close-in area of the experimental fields, for instance in the pillar between the galleries A and B. Creep tests with salt rock specimens from the TSS field show that the creep performance at room temperature of the Na2β rock salt to be considered in the experimental fields can be sufficiently accurately described by the reference creep law for stationary creep used by the BGR (Bundesanstalt f. Geowissenschaften und Rohstoffe).The experimental in-situ results on the permeability of the salt rock in the experimental fields indicate i.a. very low permeabilities, except for a restricted, local area within the loosening zone below gallery B. This exhibits relatively high permeabilities. The experimental in-situ results on the permeability of the backfilling in the experimental galleries show that during the experimental measuring period, an only small change in permeability due to compaction of the backfilling material was observed. This result agrees with results of compaction tests performed by the GSF. The measured results show a difference in permeabilities between backfilling material subject to heating up, and colder material. (orig.) [de

  14. Whispers of the Unspeakable: New York and Montreal Newspaper Coverage of the Oscar Wilde Trials in 1895

    Directory of Open Access Journals (Sweden)

    Greg Robinson

    2015-03-01

    Full Text Available Greg Robinson’s article “Whispers of the Unspeakable: New York and Montreal Newspaper Coverage of the Oscar Wilde Trials in 1895,” originally published in 2010 in the French-language journal Rue des Beaux Arts, no. 24 (2010, is here republished and—with much gratitude—translated (for the original text, please see http://www.oscholars.com/RBA/twenty-four/24.7/Articles.htm. Robinson’s transnational study focuses on how reading the specific language of newspaper reports of the Oscar Wilde case, literally from a distance, from places less emotionally attached to and nationally distinct from the scandal’s epicenter in London, England, provides insight into “the state of everyday public knowledge and discussion of (homosexuality, at least west of the Atlantic”; thus Robinson’s fascinating research, which involves numerous newspapers—from the elite New York Times to the New York Herald, from the Montreal Daily Star to the French-language papers of Quebec—concludes that the popular press, read transnationally, offers key insights into the developing attitudes toward and levels of interest in the newly forming identity of the “homosexual” across societies.

  15. How to use The National Gallery as a cross curricular approach to weather and climate studies at primary level.

    Science.gov (United States)

    Hansen, P. J. K.

    2009-09-01

    How to use The National Gallery as a cross curricular approach to weather and climate studies at primary level. Pål J. Kirkeby Hansen Faculty of Education and International Studies, Oslo University College (PalKirkeby.Hansen@lui.hio.no) Weather and climate are topics in natural science and geography in primary and secondary education in most countries. The pupils are often doing own weather observations and measurements and are presenting the results oral, by posters or with digital aids. They also use the Internet with all its relevant resources in their studies to develop vocabulary, practical and conceptual knowledge. Knowledge about weather and climate is parts of liberal education and could be projected to other topics in science and to topics in other subjects, for instance: history, social geography, literature and arts. This article reports from a case study in grade 3 classes (age 9 year) during their Weather Week. Their science teacher was, quite untypical, also educated in art history. She arranged a visited to The National Gallery with the double agenda: 1. To introduce the pupils to Norwegian canon paintings from the national romantic period, our so-called "golden age”. 2. To look for and discuss weather elements in this paintings. For one hour the museum curator guided the pupils around the water cycle by using the paintings. While the pupils' own observations of weather, clouds and wind and measurements of temperature and precipitation during the Weather Week only are point checks, the guided tour in The National Gallery gave literally "the whole picture” of the Norwegian weather and climate and of the water cycle. During the tour, the curator constantly invited the pupils to tell about and discuss what weather and water elements they were looking at when standing in front of a painting. The pupils were responsive and interested all the time. Back at school, they demonstrated that they had learned much about both weather elements, the water

  16. Characterisation of a microwave re-entrant cavity resonator for phase-equilibrium measurements and new dew-point data for a (0.25 argon + 0.75 carbon dioxide) mixture

    International Nuclear Information System (INIS)

    Tsankova, Gergana; Richter, Markus; Madigan, Adele; Stanwix, Paul L.; May, Eric F.; Span, Roland

    2016-01-01

    Highlights: • A microwave reentrant cavity resonator was refurbished and extensively characterised. • Vacuum resonance frequencies and Q-factors were modelled and experimentally validated. • Whispering gallery-type modes first-time reported for present cavity geometry. • Dew points of a (0.2491 argon + 0.7509 carbon dioxide) mixture were measured. • Measurements were carried out from T = (252–280) K at pressures up to 6.9 MPa. - Abstract: An apparatus based on a microwave re-entrant cavity resonator, originally built for accurate measurements of the dielectric permittivity of natural gas mixtures, was refurbished and extensively characterised. This was done to enable the future investigation of phase equilibria and (p, ρ, T, x) behaviour of fluid mixtures utilizing the present experimental technique. Vacuum resonance frequencies and Q-factors of the resonator’s modes were modelled using both analytic and finite element methods, and found to compare well with experimental values. The finite element models helped to identify two whispering gallery-type modes not previously reported for such cavity geometries. The models also predict distributions of the electric and magnetic fields in the re-entrant cavity resonator useful for identifying regions in the cavity more sensitive to the presence of a liquid. Following the resonator’s characterisation, its ability to measure dew points was tested using a gravimetrically prepared (0.2501 argon + 0.7499 carbon dioxide) mixture over the temperature range from (252 to 280) K at pressures from (2.8 to 6.9) MPa. The combined expanded uncertainty with a level of confidence of approximately 95% (k = 2) in dew-point temperature and pressure ranged between (0.025 and 0.044) K and from (0.009 to 0.015) MPa, respectively. We compared the experimental dew-point pressures with the recently developed multi-parameter equation of state optimised for combustion gases (EOS-CG), showing relative deviations in the range of (0

  17. Tiny Molybdenites Tell Diffusion Tales

    Science.gov (United States)

    Stein, H. J.; Hannah, J. L.

    2014-12-01

    Diffusion invokes micron-scale exchange during crystal growth and dissolution in magma chambers on short time-scales. Fundamental to interpreting such data are assumptions on magma-fluid dynamics at all scales. Nevertheless, elemental diffusion profiles are used to estimate time scales for magma storage, eruption, and recharge. An underutilized timepiece to evaluate diffusion and 3D mobility of magmatic fluids is high-precision Re-Os dating of molybdenite. With spatially unique molybdenite samples from a young ore system (e.g., 1 Ma) and a double Os spike, analytical errors of 1-3 ka unambiguously separate events in time. Re-Os ages show that hydrous shallow magma chambers locally recharge and expel Cu-Mo-Au-silica as superimposed stockwork vein networks at time scales less than a few thousand years [1]. Re-Os ages provide diffusion rates controlled by a dynamic crystal mush, accumulation and expulsion of metalliferous fluid, and magma reorganization after explosive crystallization events. Importantly, this approach has broad application far from ore deposits. Here, we use Re-Os dating of molybdenite to assess time scales for generating and diffusing metals through the deep crust. To maximize opportunity for chemical diffusion, we use a continental-scale Sveconorwegian mylonite zone for the study area. A geologically constrained suite of molybdenite samples was acquired from quarry exposures. Molybdenite, previously unreported, is extremely scarce. Tiny but telling molybdenites include samples from like occurrences to assure geologic accuracy in Re-Os ages. Ages range from mid-Mesoproterozoic to mid-Neoproterozoic, and correspond to early metamorphic dehydration of a regionally widespread biotite-rich gneiss, localized melting of gneiss to form cm-m-scale K-feldspar ± quartz pods, development of vapor-rich, vuggy mm stringers that serve as volatile collection surfaces in felsic leucosomes, and low-angle (relative to foliation) cross-cutting cm-scale quartz veins

  18. High-power microcavity lasers based on highly erbium-doped sol-gel aluminosilicate glasses

    International Nuclear Information System (INIS)

    Le Ngoc Chung; Chu Thi Thu Ha; Nguyen Thu Trang; Pham Thu Nga; Pham Van Hoi; Bui Van Thien

    2006-01-01

    High-power whispering-gallery-mode (WGM) lasing from highly erbium-doped sol-gel aluminosilicate microsphere cavity coupled to a half-tapered optical fiber is presented. The lasing output power as high as 0.45 mW (-3.5 dBm) was obtained from sol-gel glass microsphere cavity with diameters in the range of 40-150 μm. The sol-gel method for making highly concentration Er-doped aluminosilicate glasses with Er-ion concentrations from 0.125 to 0.65 mol% of Er 3+ is described. Controlling collected lasing wavelength at each WGM is possible by adjusting the distance between the half-taper fiber and the microcavity and by diameter of the waist of half-taper fiber. Using the analytic formulas we calculated the TE and TM lasing modes and it is shown that the experimental results are in good agreement with the calculation prediction

  19. Analysis of high-quality modes in open chaotic microcavities

    International Nuclear Information System (INIS)

    Fang, W.; Yamilov, A.; Cao, H.

    2005-01-01

    We present a numerical study of the high-quality modes in two-dimensional dielectric stadium microcavities. Although the classical ray mechanics is fully chaotic in a stadium billiard, all of the high-quality modes show a 'strong scar' around unstable periodic orbits. When the deformation (ratio of the length of the straight segments over the diameter of the half circles) is small, the high-quality modes correspond to whispering-gallery-type trajectories and their quality factors decrease monotonically with increasing deformation. At large deformation, each high-quality mode is associated with multiple unstable periodic orbits. Its quality factor changes nonmonotonically with the deformation, and there exists an optimal deformation for each mode at which its quality factor reaches a local maximum. This unusual behavior is attributed to the interference of waves propagating along different constituent orbits that could minimize light leakage out of the cavity

  20. A Microring Resonator Based Negative Permeability Metamaterial Sensor

    Directory of Open Access Journals (Sweden)

    Yao-Zhong Lan

    2011-08-01

    Full Text Available Metamaterials are artificial multifunctional materials that acquire their material properties from their structure, rather than inheriting them directly from the materials they are composed of, and they may provide novel tools to significantly enhance the sensitivity and resolution of sensors. In this paper, we derive the dispersion relation of a cylindrical dielectric waveguide loaded on a negative permeability metamaterial (NPM layer, and compute the resonant frequencies and electric field distribution of the corresponding Whispering-Gallery-Modes (WGMs. The theoretical resonant frequency and electric field distribution results are in good agreement with the full wave simulation results. We show that the NPM sensor based on a microring resonator possesses higher sensitivity than the traditional microring sensor since with the evanescent wave amplification and the increase of NPM layer thickness, the sensitivity will be greatly increased. This may open a door for designing sensors with specified sensitivity.

  1. Optical Microspherical Resonators for Biomedical Sensing

    Directory of Open Access Journals (Sweden)

    Giancarlo C. Righini

    2011-01-01

    Full Text Available Optical resonators play an ubiquitous role in modern optics. A particular class of optical resonators is constituted by spherical dielectric structures, where optical rays are total internal reflected. Due to minimal reflection losses and to potentially very low material absorption, these guided modes, known as whispering gallery modes, can confer the resonator an exceptionally high quality factor Q, leading to high energy density, narrow resonant-wavelength lines and a lengthy cavity ringdown. These attractive characteristics make these miniaturized optical resonators especially suited as laser cavities and resonant filters, but also as very sensitive sensors. First, a brief analysis is presented of the characteristics of microspherical resonators, of their fabrication methods, and of the light coupling techniques. Then, we attempt to overview some of the recent advances in the development of microspherical biosensors, underlining a number of important applications in the biomedical field.

  2. Spin coating and plasma process for 2.5D integrated photonics on multilayer polymers

    International Nuclear Information System (INIS)

    Zebda, A.; Camberlein, L.; Beche, B.; Gaviot, E.; Beche, E.; Duval, D.; Zyss, J.; Jezequel, G.; Solal, F.; Godet, C.

    2008-01-01

    Polymer spin coating, surface plasma treatment and selective UV-lithography processes have been developed to realize 2.5D photonic micro-resonators, made of disk- or ring-shaped upper rib waveguides, using common polymers such as SU8 (biphenol A ether glycidyl), PS233 (polymeric silane) and SOG (siloxane Spin on Glass). Both oxygen and argon plasma treatments, applied to PS233 and SOG before spin-coating the SU8, improve substantially the grip of multilayer devices (SU8 / PS233 or SU8 / SOG). Surface energy components derived from contact angle measurements have been used to optimize the processing conditions. In such integrated photonic devices, the both single-electromagnetic-modes called transverse electric (TE 00 ) and transverse magnetic (TM 00 ) have been excited in a SU8 micro-disk, with a single mode propagation strongly localized near the edge of the disk (i.e. the so called whispering gallery modes)

  3. Lattices of dielectric resonators

    CERN Document Server

    Trubin, Alexander

    2016-01-01

    This book provides the analytical theory of complex systems composed of a large number of high-Q dielectric resonators. Spherical and cylindrical dielectric resonators with inferior and also whispering gallery oscillations allocated in various lattices are considered. A new approach to S-matrix parameter calculations based on perturbation theory of Maxwell equations, developed for a number of high-Q dielectric bodies, is introduced. All physical relationships are obtained in analytical form and are suitable for further computations. Essential attention is given to a new unified formalism of the description of scattering processes. The general scattering task for coupled eigen oscillations of the whole system of dielectric resonators is described. The equations for the  expansion coefficients are explained in an applicable way. The temporal Green functions for the dielectric resonator are presented. The scattering process of short pulses in dielectric filter structures, dielectric antennas  and lattices of d...

  4. Optical absorption and oxygen passivation of surface states in III-nitride photonic devices

    Science.gov (United States)

    Rousseau, Ian; Callsen, Gordon; Jacopin, Gwénolé; Carlin, Jean-François; Butté, Raphaël; Grandjean, Nicolas

    2018-03-01

    III-nitride surface states are expected to impact high surface-to-volume ratio devices, such as nano- and micro-wire light-emitting diodes, transistors, and photonic integrated circuits. In this work, reversible photoinduced oxygen desorption from III-nitride microdisk resonator surfaces is shown to increase optical attenuation of whispering gallery modes by 100 cm-1 at λ = 450 nm. Comparison of photoinduced oxygen desorption in unintentionally and n+-doped microdisks suggests that the spectral changes originate from the unpinning of the surface Fermi level, likely taking place at etched nonpolar III-nitride sidewalls. An oxygen-rich surface prepared by thermal annealing results in a broadband Q improvement to state-of-the-art values exceeding 1 × 104 at 2.6 eV. Such findings emphasize the importance of optically active surface states and their passivation for future nanoscale III-nitride optoelectronic and photonic devices.

  5. Advanced Output Coupling for High Power Gyrotrons

    Energy Technology Data Exchange (ETDEWEB)

    Read, Michael [Calabazas Creek Research, Inc., San Mateo, CA (United States); Ives, Robert Lawrence [Calabazas Creek Research, Inc., San Mateo, CA (United States); Marsden, David [Calabazas Creek Research, Inc., San Mateo, CA (United States); Collins, George [Calabazas Creek Research, Inc., San Mateo, CA (United States); Temkin, Richard [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Guss, William [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Lohr, John [General Atomics, La Jolla, CA (United States); Neilson, Jeffrey [Lexam Research, Redwood City, CA (United States); Bui, Thuc [Calabazas Creek Research, Inc., San Mateo, CA (United States)

    2016-11-28

    The Phase II program developed an internal RF coupler that transforms the whispering gallery RF mode produced in gyrotron cavities to an HE11 waveguide mode propagating in corrugated waveguide. This power is extracted from the vacuum using a broadband, chemical vapor deposited (CVD) diamond, Brewster angle window capable of transmitting more than 1.5 MW CW of RF power over a broad range of frequencies. This coupling system eliminates the Mirror Optical Units now required to externally couple Gaussian output power into corrugated waveguide, significantly reducing system cost and increasing efficiency. The program simulated the performance using a broad range of advanced computer codes to optimize the design. Both a direct coupler and Brewster angle window were built and tested at low and high power. Test results confirmed the performance of both devices and demonstrated they are capable of achieving the required performance for scientific, defense, industrial, and medical applications.

  6. Nonlinear optical sub-bandgap excitation of ZnO-based photonic resonators

    Energy Technology Data Exchange (ETDEWEB)

    Bader, Christina A.; Zeuner, Franziska; Bader, Manuel H. W.; Zentgraf, Thomas; Meier, Cedrik [Department of Physics and Center for Optoelectronics and Photonics Paderborn (CeOPP), Universität Paderborn, Warburger Str. 100, 33098 Paderborn (Germany)

    2015-12-07

    Zinc oxide (ZnO) is a versatile candidate for photonic devices due to its highly efficient optical emission. However, for pumping of ZnO photonic devices UV-sources are required. Here, we investigate the alternative usage of widely available pulsed near-infrared (NIR)-sources and compare the efficiency of linear and nonlinear excitation processes. We found that bulk ZnO, ZnO thin films grown by molecular beam epitaxy, and ZnO/SiO{sub 2} microdisk devices exhibit strong nonlinear response when excited with NIR pulses (λ ≈ 1060 nm). In addition, we show that the ZnO/SiO{sub 2} microdisks exhibit sharp whispering gallery modes over the blue-yellow part of the visible spectrum for both excitation conditions and high Q-factors up to Q = 4700. The results demonstrate that nonlinear excitation is an efficient way to pump ZnO photonic devices.

  7. Nanoscale imaging of photocurrent enhancement by resonator array photovoltaic coatings

    Science.gov (United States)

    Ha, Dongheon; Yoon, Yohan; Zhitenev, Nikolai B.

    2018-04-01

    Nanoscale surface patterning commonly used to increase absorption of solar cells can adversely impact the open-circuit voltage due to increased surface area and recombination. Here, we demonstrate absorptivity and photocurrent enhancement using silicon dioxide (SiO2) nanosphere arrays on a gallium arsenide (GaAs) solar cell that do not require direct surface patterning. Due to the combined effects of thin-film interference and whispering gallery-like resonances within nanosphere arrays, there is more than 20% enhancement in both absorptivity and photocurrent. To determine the effect of the resonance coupling between nanospheres, we perform a scanning photocurrent microscopy based on a near-field scanning optical microscopy measurement and find a substantial local photocurrent enhancement. The nanosphere-based antireflection coating (ARC), made by the Meyer rod rolling technique, is a scalable and a room-temperature process; and, can replace the conventional thin-film-based ARCs requiring expensive high-temperature vacuum deposition.

  8. Refractometric sensitivity and thermal stabilization of fluorescent core microcapillary sensors: theory and experiment.

    Science.gov (United States)

    Lane, S; Marsiglio, F; Zhi, Y; Meldrum, A

    2015-02-20

    Fluorescent-core microcapillaries (FCMs) present a robust basis for the application of optical whispering gallery modes toward refractometric sensing. An important question concerns whether these devices can be rendered insensitive to local temperature fluctuations, which may otherwise limit their refractometric detection limits, mainly as a result of thermorefractive effects. Here, we first use a standard cylindrical cavity formalism to develop the refractometric and thermally limited detection limits for the FCM structure. We then measure the thermal response of a real device with different analytes in the channel and compare the result to the theory. Good stability against temperature fluctuations was obtained for an ethanol solvent, with a near-zero observed thermal shift for the transverse magnetic modes. Similarly good results could in principle be obtained for any other solvent (e.g., water), if the thickness of the fluorescent layer can be sufficiently well controlled.

  9. Voice over: Audio-visual congruency and content recall in the gallery setting.

    Science.gov (United States)

    Fairhurst, Merle T; Scott, Minnie; Deroy, Ophelia

    2017-01-01

    Experimental research has shown that pairs of stimuli which are congruent and assumed to 'go together' are recalled more effectively than an item presented in isolation. Will this multisensory memory benefit occur when stimuli are richer and longer, in an ecological setting? In the present study, we focused on an everyday situation of audio-visual learning and manipulated the relationship between audio guide tracks and viewed portraits in the galleries of the Tate Britain. By varying the gender and narrative style of the voice-over, we examined how the perceived congruency and assumed unity of the audio guide track with painted portraits affected subsequent recall. We show that tracks perceived as best matching the viewed portraits led to greater recall of both sensory and linguistic content. We provide the first evidence that manipulating crossmodal congruence and unity assumptions can effectively impact memory in a multisensory ecological setting, even in the absence of precise temporal alignment between sensory cues.

  10. Self-gated fetal cardiac MRI with tiny golden angle iGRASP: A feasibility study.

    Science.gov (United States)

    Haris, Kostas; Hedström, Erik; Bidhult, Sebastian; Testud, Frederik; Maglaveras, Nicos; Heiberg, Einar; Hansson, Stefan R; Arheden, Håkan; Aletras, Anthony H

    2017-07-01

    To develop and assess a technique for self-gated fetal cardiac cine magnetic resonance imaging (MRI) using tiny golden angle radial sampling combined with iGRASP (iterative Golden-angle RAdial Sparse Parallel) for accelerated acquisition based on parallel imaging and compressed sensing. Fetal cardiac data were acquired from five volunteers in gestational week 29-37 at 1.5T using tiny golden angles for eddy currents reduction. The acquired multicoil radial projections were input to a principal component analysis-based compression stage. The cardiac self-gating (CSG) signal for cardiac gating was extracted from the acquired radial projections and the iGRASP reconstruction procedure was applied. In all acquisitions, a total of 4000 radial spokes were acquired within a breath-hold of less than 15 seconds using a balanced steady-state free precession pulse sequence. The images were qualitatively compared by two independent observers (on a scale of 1-4) to a single midventricular cine image from metric optimized gating (MOG) and real-time acquisitions. For iGRASP and MOG images, good overall image quality (2.8 ± 0.4 and 2.6 ± 1.3, respectively, for observer 1; 3.6 ± 0.5 and 3.4 ± 0.9, respectively, for observer 2) and cardiac diagnostic quality (3.8 ± 0.4 and 3.4 ± 0.9, respectively, for observer 1; 3.6 ± 0.5 and 3.6 ± 0.9, respectively, for observer 2) were obtained, with visualized myocardial thickening over the cardiac cycle and well-defined myocardial borders to ventricular lumen and liver/lung tissue. For iGRASP, MOG, and real time, left ventricular lumen diameter (14.1 ± 2.2 mm, 14.2 ± 1.9 mm, 14.7 ± 1.1 mm, respectively) and wall thickness (2.7 ± 0.3 mm, 2.6 ± 0.3 mm, 3.0 ± 0.4, respectively) showed agreement and no statistically significant difference was found (all P > 0.05). Images with iGRASP tended to have higher overall image quality scores compared with MOG and particularly

  11. Evaporation of tiny water aggregation on solid surfaces with different wetting properties.

    Science.gov (United States)

    Wang, Shen; Tu, Yusong; Wan, Rongzheng; Fang, Haiping

    2012-11-29

    The evaporation of a tiny amount of water on the solid surface with different wettabilities has been studied by molecular dynamics simulations. From nonequilibrium MD simulations, we found that, as the surface changed from hydrophobic to hydrophilic, the evaporation speed did not show a monotonic decrease as intuitively expected, but increased first, and then decreased after it reached a maximum value. The analysis of the simulation trajectory and calculation of the surface water interaction illustrate that the competition between the number of water molecules on the water-gas surface from where the water molecules can evaporate and the potential barrier to prevent those water molecules from evaporating results in the unexpected behavior of the evaporation. This finding is helpful in understanding the evaporation on biological surfaces, designing artificial surfaces of ultrafast water evaporating, or preserving water in soil.

  12. Selected aspects of tiny vetch [Vicia hirsuta (L. Gray S.F.] seed ecology: generative reproduction and effects of seed maturity and seed storage on seed germination

    Directory of Open Access Journals (Sweden)

    Magdalena Kucewicz

    2012-12-01

    Full Text Available Vicia hirsuta (L. Gray S.F. (tiny vetch is a common and persistent segetal weed. Tiny vetch seeds and pods reach different stages of maturity during the crop harvest season. Some seeds that mature before cereal harvest are shed in the field and deposited in the soil seed bank, while others become incorporated into seed material. The objective of this study was to describe selected aspects of tiny vetch seed ecology: to determine the rate of individual reproduction of vetch plants growing in winter and spring grain crops and to evaluate the germination of seeds at different stages of maturity, subject to storage conditions. The seeds and pods of V. hirsuta were sorted according to their development stages at harvest and divided into two groups. The first group was stored under laboratory conditions for two months. In the autumn of the same year, the seeds were subjected to germination tests. The remaining seeds were stored in a storeroom, and were planted in soil in the spring. The germination rate was evaluated after 8 months of storage. Potential productivity (developed pods and flowers, fruit buds was higher in plants fruiting in winter wheat than in spring barley. Vetch plants produced around 17-26% more pods (including cracked, mature, greenish-brown and green pods and around 25% less buds in winter wheat than in spring barley. Immature seeds were characterized by the highest germination capacity. Following storage under laboratory conditions and stratification in soil, mature seeds germinated at a rate of several percent. After storage in a storeroom, seeds at all three development stages broke dormancy at a rate of 72- 75%. The high germination power of tiny vetch seeds stored in a storeroom indicates that this plant can be classified as an obligatory speirochoric weed species.

  13. Macronuclear genome structure of the ciliate Nyctotherus ovalis: Single-gene chromosomes and tiny introns

    Directory of Open Access Journals (Sweden)

    Landweber Laura F

    2008-12-01

    Full Text Available Abstract Background Nyctotherus ovalis is a single-celled eukaryote that has hydrogen-producing mitochondria and lives in the hindgut of cockroaches. Like all members of the ciliate taxon, it has two types of nuclei, a micronucleus and a macronucleus. N. ovalis generates its macronuclear chromosomes by forming polytene chromosomes that subsequently develop into macronuclear chromosomes by DNA elimination and rearrangement. Results We examined the structure of these gene-sized macronuclear chromosomes in N. ovalis. We determined the telomeres, subtelomeric regions, UTRs, coding regions and introns by sequencing a large set of macronuclear DNA sequences (4,242 and cDNAs (5,484 and comparing them with each other. The telomeres consist of repeats CCC(AAAACCCCn, similar to those in spirotrichous ciliates such as Euplotes, Sterkiella (Oxytricha and Stylonychia. Per sequenced chromosome we found evidence for either a single protein-coding gene, a single tRNA, or the complete ribosomal RNAs cluster. Hence the chromosomes appear to encode single transcripts. In the short subtelomeric regions we identified a few overrepresented motifs that could be involved in gene regulation, but there is no consensus polyadenylation site. The introns are short (21–29 nucleotides, and a significant fraction (1/3 of the tiny introns is conserved in the distantly related ciliate Paramecium tetraurelia. As has been observed in P. tetraurelia, the N. ovalis introns tend to contain in-frame stop codons or have a length that is not dividable by three. This pattern causes premature termination of mRNA translation in the event of intron retention, and potentially degradation of unspliced mRNAs by the nonsense-mediated mRNA decay pathway. Conclusion The combination of short leaders, tiny introns and single genes leads to very minimal macronuclear chromosomes. The smallest we identified contained only 150 nucleotides.

  14. Pollination networks of oil-flowers: a tiny world within the smallest of all worlds.

    Science.gov (United States)

    Bezerra, Elisângela L S; Machado, Isabel C; Mello, Marco A R

    2009-09-01

    1. In the Neotropics, most plants depend on animals for pollination. Solitary bees are the most important vectors, and among them members of the tribe Centridini depend on oil from flowers (mainly Malpighiaceae) to feed their larvae. This specialized relationship within 'the smallest of all worlds' (a whole pollination network) could result in a 'tiny world' different from the whole system. This 'tiny world' would have higher nestedness, shorter path lengths, lower modularity and higher resilience if compared with the whole pollination network. 2. In the present study, we contrasted a network of oil-flowers and their visitors from a Brazilian steppe ('caatinga') to whole pollination networks from all over the world. 3. A network approach was used to measure network structure and, finally, to test fragility. The oil-flower network studied was more nested (NODF = 0.84, N = 0.96) than all of the whole pollination networks studied. Average path lengths in the two-mode network were shorter (one node, both for bee and plant one-mode network projections) and modularity was lower (M = 0.22 and four modules) than in all of the whole pollination networks. Extinctions had no or small effects on the network structure, with an average change in nestedness smaller than 2% in most of the cases studied; and only two species caused coextinctions. The higher the degree of the removed species, the stronger the effect and the higher the probability of a decrease in nestedness. 4. We conclude that the oil-flower subweb is more cohesive and resilient than whole pollination networks. Therefore, the Malpighiaceae have a robust pollination service in the Neotropics. Our findings reinforce the hypothesis that each ecological service is in fact a mosaic of different subservices with a hierarchical structure ('webs within webs').

  15. The Novohrad Museum and Gallery in Lučenec past and present (História a súčasnosť Novohradského múzea a galérie v Lučenci

    Directory of Open Access Journals (Sweden)

    Michaela Škodová

    2016-09-01

    Full Text Available The Novohrad Museum and Gallery in Lučenec specializes in the regional history of enamel- and glass-making and visual arts. It holds a collection of over 30,000 art, archeo-logical, historical and ethnological objects. Since 1983, the musem and gallery have been a host to the annual Acquarelle Triennale and since 1989, it has hosted the oldest symposium of its kind in Slovakia, the International Ceramic Symposium, which showcases the contemporary ceramic production in Slovakia. This paper outlines the history of the museum and its focus, concentrating on the work done in the last decade.

  16. Tiny Ultraviolet Polarimeter for Earth Stratosphere from Space Investigation

    Science.gov (United States)

    Nevodovskyi, P. V.; Morozhenko, O. V.; Vidmachenko, A. P.; Ivakhiv, O.; Geraimchuk, M.; Zbrutskyi, O.

    2015-09-01

    One of the reasons for climate change (i.e., stratospheric ozone concentrations) is connected with the variations in optical thickness of aerosols in the upper sphere of the atmosphere (at altitudes over 30 km). Therefore, aerosol and gas components of the atmosphere are crucial in the study of the ultraviolet (UV) radiation passing upon the Earth. Moreover, a scrupulous study of aerosol components of the Earth atmosphere at an altitude of 30 km (i.e., stratospheric aerosol), such as the size of particles, the real part of refractive index, optical thickness and its horizontal structure, concentration of ozone or the upper border of the stratospheric ozone layer is an important task in the research of the Earth climate change. At present, the Main Astronomical Observatory of the National Academy of Sciences (NAS) of Ukraine, the National Technical University of Ukraine "KPI"and the Lviv Polytechnic National University are engaged in the development of methodologies for the study of stratospheric aerosol by means of ultraviolet polarimeter using a microsatellite. So fare, there has been created a sample of a tiny ultraviolet polarimeter (UVP) which is considered to be a basic model for carrying out space experiments regarding the impact of the changes in stratospheric aerosols on both global and local climate.

  17. Anisotropic modelling of Opalinus Clay behaviour: From triaxial tests to gallery excavation application

    Directory of Open Access Journals (Sweden)

    François Bertrand

    2017-06-01

    Full Text Available Deep repository in geological formations is the preferential solution considered in many countries to manage high-level nuclear wastes. In Switzerland, the Opalinus Clay is a candidate host rock. In this context, in situ and laboratory tests are conducted on Opalinus Clay to demonstrate the feasibility of deep disposal in this argillaceous formation. This paper presents a constitutive model able to fit the experimental data obtained from some triaxial tests conducted by Jahns (2013 on cores from borehole Schlattingen SLA-1. The elasto-plastic behaviour of Opalinus Clay is reproduced thanks to a Drucker-Prager model, taking into account the anisotropy behaviour of this sedimentary rock. The objective is to employ a single set of parameters representative of the material. In a second version of the model, the stress-dependence of the elastic properties and damage are taken into account. Finally, the parameters calibrated with experimental tests are used to simulate the excavation of a gallery with a second gradient approach.

  18. SenStick: Comprehensive Sensing Platform with an Ultra Tiny All-In-One Sensor Board for IoT Research

    Directory of Open Access Journals (Sweden)

    Yugo Nakamura

    2017-01-01

    Full Text Available We propose a comprehensive sensing platform called SenStick, which is composed of hardware (ultra tiny all-in-one sensor board, software (iOS, Android, and PC, and 3D case data. The platform aims to allow all the researchers to start IoT research, such as activity recognition and context estimation, easily and efficiently. The most important contribution is the hardware that we have designed. Various sensors often used for research are embedded in an ultra tiny board with the size of 50 mm (W × 10 mm (H × 5 mm (D and weight around 3 g including a battery. Concretely, the following sensors are embedded on this board: acceleration, gyro, magnetic, light, UV, temperature, humidity, and pressure. In addition, this board has BLE (Bluetooth low energy connectivity and capability of a rechargeable battery. By using 110 mAh battery, it can run more than 15 hours. The most different point from other similar boards is that our board has a large flash memory for logging all the data without a smartphone. By using SenStick, all the users can collect various data easily and focus on IoT data analytics. In this paper, we introduce SenStick platform and some case studies. Through the user study, we confirmed the usefulness of our proposed platform.

  19. Investigations for a change of an excavation damaged zone with time at the 250 m gallery in the Horonobe Underground Research Laboratory

    International Nuclear Information System (INIS)

    Aoyagi, Kazuhei; Tsusaka, Kimikazu; Kondo, Keiji; Inagaki, Daisuke; Kubota, Kenji; Tokiwa, Tetsuya

    2014-01-01

    The authors have been conducting seismic and resistivity tomography surveys in a gallery of the Horonobe Underground Research Laboratory in order to investigate an extent of an Excavation Damaged Zone (EDZ) along time. The objective of this paper is to discuss an influence of fracture distribution and water saturation of a rock mass on variations in seismic velocity and the value of apparent resistivity in an EDZ. Based on the result of seismic tomography survey, the extent of a layer which has low seismic velocity was about 1.0 m from the gallery wall after excavation of the tomography area. From the results of resistivity tomography survey, the value of apparent resistivity has not changed remarkably along time. To investigate a relationship between variations in seismic velocity and density of fracture in the survey area, the authors built a three dimensional fracture model around the tomography area. From the comparison of seismic velocity with density of fracture, seismic velocity decreased almost linearly as the density of fracture increased. Also, it was found that density of fracture in the layer of low seismic velocity could be estimated using a simple numeric model. >From this result, seismic tomography survey and investigation of density of fracture are suitable method for evaluation of an EDZ. (author)

  20. SERS-active ZnO/Ag hybrid WGM microcavity for ultrasensitive dopamine detection

    Science.gov (United States)

    Lu, Junfeng; Xu, Chunxiang; Nan, Haiyan; Zhu, Qiuxiang; Qin, Feifei; Manohari, A. Gowri; Wei, Ming; Zhu, Zhu; Shi, Zengliang; Ni, Zhenhua

    2016-08-01

    Dopamine (DA) is a potential neuro modulator in the brain which influences a variety of motivated behaviors and plays a key role in life science. A hybrid ZnO/Ag microcavity based on Whispering Gallery Mode (WGM) effect has been developed for ultrasensitive detection of dopamine. Utilizing this effect of structural cavity mode, a Raman signal of R6G (5 × 10-3 M) detected by this designed surface-enhanced Raman spectroscopy (SERS)-active substrate was enhanced more than 10-fold compared with that of ZnO film/Ag substrate. Also, this hybrid microcavity substrate manifests high SERS sensitivity to rhodamine 6 G and detection limit as low as 10-12 M to DA. The Localized Surface Plasmons of Ag nanoparticles and WGM-enhanced light-matter interaction mainly contribute to the high SERS sensitivity and help to achieve a lower detection limit. This designed SERS-active substrate based on the WGM effect has the potential for detecting neurotransmitters in life science.

  1. Manipulating Ion Migration for Highly Stable Light-Emitting Diodes with Single-Crystalline Organometal Halide Perovskite Microplatelets.

    Science.gov (United States)

    Chen, Mingming; Shan, Xin; Geske, Thomas; Li, Junqiang; Yu, Zhibin

    2017-06-27

    Ion migration has been commonly observed as a detrimental phenomenon in organometal halide perovskite semiconductors, causing the measurement hysteresis in solar cells and ultrashort operation lifetimes in light-emitting diodes. In this work, ion migration is utilized for the formation of a p-i-n junction at ambient temperature in single-crystalline organometal halide perovskites. The junction is subsequently stabilized by quenching the ionic movement at a low temperature. Such a strategy of manipulating the ion migration has led to efficient single-crystalline light-emitting diodes that emit 2.3 eV photons starting at 1.8 V and sustain a continuous operation for 54 h at ∼5000 cd m -2 without degradation of brightness. In addition, a whispering-gallery-mode cavity and exciton-exciton interaction in the perovskite microplatelets have both been observed that can be potentially useful for achieving electrically driven laser diodes based on single-crystalline organometal halide perovskite semiconductors.

  2. Giant narrowband twin-beam generation along the pump-energy propagation direction

    Science.gov (United States)

    Pérez, Angela M.; Spasibko, Kirill Yu; Sharapova, Polina R.; Tikhonova, Olga V.; Leuchs, Gerd; Chekhova, Maria V.

    2015-07-01

    Walk-off effects, originating from the difference between the group and phase velocities, limit the efficiency of nonlinear optical interactions. While transverse walk-off can be eliminated by proper medium engineering, longitudinal walk-off is harder to avoid. In particular, ultrafast twin-beam generation via pulsed parametric down-conversion and four-wave mixing is only possible in short crystals or fibres. Here we show that in high-gain parametric down-conversion, one can overcome the destructive role of both effects and even turn them into useful tools for shaping the emission. In our experiment, one of the twin beams is emitted along the pump Poynting vector or its group velocity matches that of the pump. The result is markedly enhanced generation of both twin beams, with the simultaneous narrowing of angular and frequency spectrum. The effect will enable efficient generation of ultrafast twin photons and beams in cavities, waveguides and whispering-gallery mode resonators.

  3. Room temperature three-photon pumped CH3NH3PbBr3 perovskite microlasers

    Science.gov (United States)

    Gao, Yisheng; Wang, Shuai; Huang, Can; Yi, Ningbo; Wang, Kaiyang; Xiao, Shumin; Song, Qinghai

    2017-03-01

    Hybrid lead halide perovskites have made great strides in next-generation light-harvesting and light emitting devices. Recently, they have also shown great potentials in nonlinear optical materials. Two-photon absorption and two-photon light emission have been thoroughly studied in past two years. However, the three-photon processes are rarely explored, especially for the laser emissions. Here we synthesized high quality CH3NH3PbBr3 perovskite microstructures with solution processed precipitation method and studied their optical properties. When the microstructures are pumped with intense 1240 nm lasers, we have observed clear optical limit effect and the band-to-band photoluminescence at 540 nm. By increasing the pumping density, whispering-gallery-mode based microlasers have been achieved from CH3NH3PbBr3 perovskite microplate and microrod for the first time. This work demonstrates the potentials of hybrid lead halide perovskites in nonlinear photonic devices.

  4. Label-free, single-object sensing with a microring resonator: FDTD simulation.

    Science.gov (United States)

    Nguyen, Dan T; Norwood, Robert A

    2013-01-14

    Label-free, single-object sensing with a microring resonator is investigated numerically using the finite difference time-domain (FDTD) method. A pulse with ultra-wide bandwidth that spans over several resonant modes of the ring and of the sensing object is used for simulation, enabling a single-shot simulation of the microring sensing. The FDTD simulation not only can describe the circulation of the light in a whispering-gallery-mode (WGM) microring and multiple interactions between the light and the sensing object, but also other important factors of the sensing system, such as scattering and radiation losses. The FDTD results show that the simulation can yield a resonant shift of the WGM cavity modes. Furthermore, it can also extract eigenmodes of the sensing object, and therefore information from deep inside the object. The simulation method is not only suitable for a single object (single molecule, nano-, micro-scale particle) but can be extended to the problem of multiple objects as well.

  5. Optomechanics in a Levitated Droplet of Superfluid Helium

    Science.gov (United States)

    Brown, Charles; Harris, Glen; Harris, Jack

    2017-04-01

    A critical issue common to all optomechanical systems is dissipative coupling to the environment, which limits the system's quantum coherence. Superfluid helium's extremely low optical and mechanical dissipation, as well as its high thermal conductivity and its ability cool itself via evaporation, makes the mostly uncharted territory of superfluid optomechanics an exciting avenue for exploring quantum effects in macroscopic objects. I will describe ongoing work that aims to exploit the unique properties of superfluid helium by constructing an optomechanical system consisting of a magnetically levitated droplet of superfluid helium., The optical whispering gallery modes (WGMs) of the droplet, as well as the mechanical oscillations of its surface, should offer exceptionally low dissipation, and should couple to each other via the usual optomechanical interactions. I will present recent progress towards this goal, and also discuss the background for this work, which includes prior demonstrations of magnetic levitation of superfluid helium, high finesse WGMs in liquid drops, and the self-cooling of helium drops in vacuum.

  6. Spiral Form of the Human Cochlea Results from Spatial Constraints.

    Science.gov (United States)

    Pietsch, M; Aguirre Dávila, L; Erfurt, P; Avci, E; Lenarz, T; Kral, A

    2017-08-08

    The human inner ear has an intricate spiral shape often compared to shells of mollusks, particularly to the nautilus shell. It has inspired many functional hearing theories. The reasons for this complex geometry remain unresolved. We digitized 138 human cochleae at microscopic resolution and observed an astonishing interindividual variability in the shape. A 3D analytical cochlear model was developed that fits the analyzed data with high precision. The cochlear geometry neither matched a proposed function, namely sound focusing similar to a whispering gallery, nor did it have the form of a nautilus. Instead, the innate cochlear blueprint and its actual ontogenetic variants were determined by spatial constraints and resulted from an efficient packing of the cochlear duct within the petrous bone. The analytical model predicts well the individual 3D cochlear geometry from few clinical measures and represents a clinical tool for an individualized approach to neurosensory restoration with cochlear implants.

  7. Investigation and modelling of rare-earth activated waveguide structures

    International Nuclear Information System (INIS)

    Wolinski, W.; Malinowski, M.; Mossakowska-Wyszynska, A.; Piramidowicz, R.; Szczepanski, P.

    2005-01-01

    In this paper the overview of the recent study on the rare-earth activated waveguides performed in the Optoelectronic Department of IMiO is presented. We reported on the development of rare earth-doped fluorozirconate (ZBLAN) glass fibers that allow a construction of a new family of visible and ultraviolet fiber lasers pumped by upconversion. Especially the performance of holmium devices is presented. The properties of laser planar waveguides obtained by the LPE process and the growth conditions of rare earths doped YAG layers are presented. In this paper we present also the theoretical study of the nonlinear operation of planar waveguide laser, as an example the microdisk Nd:YAG structure is discussed. We derived an approximate formula which relates the small signal gain in the Nd:YAG active medium and the laser characteristics, obtained for whispering-gallery modes and radial modes, to the output power and real parameters of the laser structure (authors)

  8. High-Q/V Monolithic Diamond Microdisks Fabricated with Quasi-isotropic Etching.

    Science.gov (United States)

    Khanaliloo, Behzad; Mitchell, Matthew; Hryciw, Aaron C; Barclay, Paul E

    2015-08-12

    Optical microcavities enhance light-matter interactions and are essential for many experiments in solid state quantum optics, optomechanics, and nonlinear optics. Single crystal diamond microcavities are particularly sought after for applications involving diamond quantum emitters, such as nitrogen vacancy centers, and for experiments that benefit from diamond's excellent optical and mechanical properties. Light-matter coupling rates in experiments involving microcavities typically scale with Q/V, where Q and V are the microcavity quality-factor and mode-volume, respectively. Here we demonstrate that microdisk whispering gallery mode cavities with high Q/V can be fabricated directly from bulk single crystal diamond. By using a quasi-isotropic oxygen plasma to etch along diamond crystal planes and undercut passivated diamond structures, we create monolithic diamond microdisks. Fiber taper based measurements show that these devices support TE- and TM-like optical modes with Q > 1.1 × 10(5) and V < 11(λ/n) (3) at a wavelength of 1.5 μm.

  9. Investigation of gel formation and volatilization of acetate acid in magnesium acetate droplets by the optical tweezers.

    Science.gov (United States)

    Lv, Xi-Juan; Wang, Yang; Cai, Chen; Pang, Shu-Feng; Ma, Jia-Bi; Zhang, Yun-Hong

    2018-07-05

    Hygroscopicity and volatility of single magnesium acetate (MgAc 2 ) aerosol particles at various relative humidities (RHs) are studied by a single-beam optical tweezers, and refractive indices (RIs) and morphology are characterized by cavity enhanced Raman spectroscopy. Gel formation and volatilization of acetate acid (HAc) in MgAc 2 droplets are observed. Due to the formation of amorphous gel structure, water transposition in droplets at RH magnesium hydroxide (Mg(OH) 2 ) inclusions are formed in MgAc 2 droplets due to the volatilization of HAc, and whispering gallery modes (WGMs) of MgAc 2 droplets in the Raman spectrum quench after 50,000 s. In sharp contrast, after 86,000 s at RH ≈ 70%, NaAc droplets are in well-mixed liquid states, containing soluble sodium hydroxide (NaOH). At this state, the RI of NaAc droplet is increased, and the quenching of WGMs is not observable. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Exhibiting Western Desert Aboriginal painting in Australia’s public galleries: an institutional analysis, 1981-2002

    Directory of Open Access Journals (Sweden)

    Jim Berryman

    2012-12-01

    Full Text Available This paper documents and analyses the exhibition history of Aboriginal painting in Australia’s public art galleries over a two-decade period. It concentrates on Western Desert acrylics but is not confined to this movement or region alone. Based on a review of catalogues from key exhibitions, it identifies three interpretative frameworks used by curators to validate the presence of Aboriginal painting in the contemporary art realm. These modes of interpretation are called the aesthetic, ethnographic and the ownership discourses. Despite being a problematic art at odds with conventional art-historical classifications, Aboriginal painting was elevated to a position of prominence in Australian art history. Institutionally, Western Desert painting found legitimacy in the dominant aesthetic legacy of modernism. This modernist art historiography overrode the minority interests of cultural pluralism and critical postmodernism.

  11. Tiny Grains Give Huge Gains: Nanocrystal–Based Signal Amplification for Biomolecule Detection

    Science.gov (United States)

    Tong, Sheng; Ren, Binbin; Zheng, Zhilan; Shen, Han; Bao, Gang

    2013-01-01

    Nanocrystals, despite their tiny sizes, contain thousands to millions of atoms. Here we show that the large number of atoms packed in each metallic nanocrystal can provide a huge gain in signal amplification for biomolecule detection. We have devised a highly sensitive, linear amplification scheme by integrating the dissolution of bound nanocrystals and metal-induced stoichiometric chromogenesis, and demonstrated that signal amplification is fully defined by the size and atom density of nanocrystals, which can be optimized through well-controlled nanocrystal synthesis. Further, the rich library of chromogenic reactions allows implementation of this scheme in various assay formats, as demonstrated by the iron oxide nanoparticle linked immunosorbent assay (ILISA) and blotting assay developed in this study. Our results indicate that, owing to the inherent simplicity, high sensitivity and repeatability, the nanocrystal based amplification scheme can significantly improve biomolecule quantification in both laboratory research and clinical diagnostics. This novel method adds a new dimension to current nanoparticle-based bioassays. PMID:23659350

  12. An Allergen Portrait Gallery: Representative Structures and an Overview of IgE Binding Surfaces

    Directory of Open Access Journals (Sweden)

    Ovidiu Ivanciuc

    2010-10-01

    Full Text Available Recent progress in the biochemical classification and structural determination of allergens and allergen–antibody complexes has enhanced our understanding of the molecular determinants of allergenicity. Databases of allergens and their epitopes have facilitated the clustering of allergens according to their sequences and, more recently, their structures. Groups of similar sequences are identified for allergenic proteins from diverse sources, and all allergens are classified into a limited number of protein structural families. A gallery of experimental structures selected from the protein classes with the largest number of allergens demonstrate the structural diversity of the allergen universe. Further comparison of these structures and identification of areas that are different from innocuous proteins within the same protein family can be used to identify features specific to known allergens. Experimental and computational results related to the determination of IgE binding surfaces and methods to define allergen-specific motifs are highlighted.

  13. Plant food resources and the diet of a parrot community in a gallery forest of the southern Pantanal (Brazil

    Directory of Open Access Journals (Sweden)

    J. Ragusa-Netto

    Full Text Available Neotropical parrots usually forage in forest canopies for nectar, flowers, leaves, fruit pulp, and seeds. As they have no all-purpose territories, these birds usually exploit vegetation mosaics in order to use plentiful resources as they become available. In this study we examine the use of a gallery forest in the southern Pantanal (Brazil by a diverse parrot community that ranged from Brotogeris chiriri (a small species to Ara chloroptera (a large one. Plant food resources principally used by parrots were abundantly available during the rainy season (fleshy fruits, the annual floods (fleshy fruits, and the dry season (flowers. While both smaller and larger species foraged on fruits, parakeets largely consumed the pulp, while larger parrot species used pulp and seeds. In the dry season parakeets foraged extensively on nectar, especially Inga vera nectar that was abundantly available during the last two months of the dry season, the harshest period of the year. Among larger parrots, only Propyrrhura auricollis frequently harvested nectar. Fruits maturing during floods, despite being fish- or water- dispersed were extensively used by the parrots. Hence, unlike what happens in most other Neotropical dry forests, occurrence of a fruiting peak during the annual flooding, which occurs in the transition from the wet to the dry season, constitutes an extra and significant episode of food availability, since in this period, fruit production normally declines. Therefore, the unique and abundant availability of flowers and fruits in this gallery forest may account for the presence of large parrot populations in the southern Pantanal.

  14. SMS Security System on Mobile Devices Using Tiny Encryption Algorithm

    Science.gov (United States)

    Novelan, M. S.; Husein, A. M.; Harahap, M.; Aisyah, S.

    2018-04-01

    The development of telecommunications technology is so rapid has given such great benefits. With the telecommunication technology, distance and time no longer be a significant obstacle. One of the results of telecommunications technology that is well known is the Short Message Service. In this study developed an application on the mobile phone to modify the SMS message into ciphertext so that the information content of the SMS is not known by others. SMS delivery system for encrypting messages into ciphertext using a key that is entered by the sender then sends to the destination number. SMS reception system to decrypt it to others via SMS without the fear of information from these messages will be known by others. The method used in the system encrypt and decrypt the message is the algorithm Tiny Encryption Algorithm and implemented using the Java programming language. JDK 1.7 as the Java programming language ciphertext into plaintext using the key entered by the receiver and displays the original message to the recipient. This application can be used by someone who wants to send a confidential information and the Java compiler. Eclipse, a Java SDK and the Android SDK as a Java source code editor.

  15. Geology and geochronology of the Sub-Antarctic Snares Islands/Tini Heke, New Zealand

    DEFF Research Database (Denmark)

    Scott, JM; Turnbull, IM; Sagar, MW

    2015-01-01

    are prismatic and yield an essentially unimodal age population of c. 116 Ma that is within error of the granodiorite. These properties suggest that the dated raft represents a meta-igneous rock despite its mica-rich nature. Some schistose rocks on the Western Chain contain coarse relict plagioclase phenocrysts...... and appear to have an igneous protolith. No conclusive metasedimentary rocks have been identified, although sillimanite-bearing mica-rich schist occurs on Rua. Deformation of the crystalline rocks occurred after Snares Granite intrusion and before cooling below muscovite K–Ar closure at 400 ± 50 °C at 95 Ma......The first comprehensive geological map, a summary of lithologies and new radiogenic isotope data (U–Pb, Rb–Sr) are presented for crystalline rocks of the Sub-Antarctic Snares Islands/Tini Heke, 150 km south of Stewart Island. The main lithology is Snares Granite (c. 109 Ma from U–Pb dating...

  16. PENINGKATAN AKTIVITAS DAN HASIL BELAJAR AKUNTANSI MATERI LAPORAN KEUANGAN MELALUI METODE GALLERY WALK DUATI-DUATA

    Directory of Open Access Journals (Sweden)

    Nining Mariyaningsih

    2014-06-01

    Full Text Available In learning accounting, conventional learning models are still frequently used by the teacher. As a result, the learning become monotonous and it’s not maximum. The problem of this study is wheather through Gallery Walk Duati-Duata can improve the activity and learning outcomes of accounting students.This study was class action research which was designed into two main cycles. Each cycle consisted of four stages started from planning, acting, observing and reflecting. The result showed that : (1 Learning activities increase from 27,78% before cycle, 69,45% in first cycle and 93,88% in second cycle, (2 The learning outcomes increase, from 22,22% before siklus, 75% in first cycle and 94,44% in second cycle. Therefore the use of this methods could be one of the reference of teachers in implementing the learning process.

  17. Alloying effect on K shell X-ray fluorescence cross-sections and yields in Ti-Ni based shape memory alloys

    Directory of Open Access Journals (Sweden)

    Bünyamin Alım

    2018-04-01

    Full Text Available K shell X-ray fluorescence cross-sections (σKα, σKβ and σK, and K shell fluorescence yields (ωK of Ti, Ni both in pure metals and in different alloy compositions (TixNi1-x; x = 0.3, 0.4, 0.5, 0.6, 0.7 were measured by using energy dispersive X-ray fluorescence (EDXRF technique. The samples were excited by 22.69 keV X-rays from a 10 mCi Cd-109 radioactive point source and K X rays emitted by samples were counted by a high resolution Si(Li solid-state detector coupled to a 4 K multichannel analyzer (MCA. The alloying effects on the X-ray fluorescence (XRF parameters of Ti-Ni shape memory alloys (SMAs were investigated. It is clearly observed that alloying effect causes to change in K shell XRF parameter values in Ti-Ni based SMAs for different compositions of x. Also, the present investigation makes it possible to perform reliable interpretation of experimental σKα, σKβ and ωK values for Ti and Ni in SMAs and can also provide quantitative information about the changes of K shell X-ray fluorescence cross sections and fluorescence yields of these metals with alloy composition. Keywords: Alloying effect, XRF, K X-ray fluorescence cross-section, K shell fluorescence yield, Shape memory alloy

  18. Geophysical monitoring of the EDZ during a gallery excavation in the Opalinus clay of the Mont Terri URL: anomalies of noble gases and self-potential associated with fractures and fluid dynamics in a horizontal borehole

    International Nuclear Information System (INIS)

    Maineult, A.; Mahiouz, K.; Lesparre, N.; Thomas, B.; Lavielle, B.; Nussbaum, C.; Wieczorek, K.; Gibert, D.; Kergosien, B.; Nicollin, F.

    2012-01-01

    Document available in extended abstract form only. The research underground rock laboratory (URL) of Mont Terri (Switzerland) was established in 1996 in a Mesozoic clay-stone formation (Opalinus Clay). It is aimed at studying the hydro-mechanical, thermal, geochemical and geophysical behaviour of argillaceous formations in the context of radioactive waste disposal. The EZ-G experiments were designed to monitor the EDZ evolution. The EZ-G08 experiment started in September 2007 to study the EDZ changes at different time scales during the tunnelling of gallery Ga08 starting from the northern part of the URL toward the end-face of the gallery Ga04. Before the excavation process started, we characterized the petrology and the structural properties of the core of the horizontal, 12-m long borehole BEZ-G5 drilled in the end-face of gallery Ga04 (first 2 meters in the shaly facies, the rest in the sandy facies). We quantified its noble gas content for studying gas transport processes in rocks and connected fracture networks. Depletion in He can be observed in the EDZ and other noble gases can also increase as desaturation processes occur. Inflows of water occurred in the borehole few weeks after its drilling until the junction of galleries Ga08 and Ga04. Water amounts of few litres were commonly released in other boreholes in the URL. We recorded the natural electrical potentials (self-potentials - SP), in BEZ-G5. SP originate from the movement of fluid, the diffusion of concentration or temperature gradients, and are sensitive to any change occurring in them. Borehole BEZ-G5 was equipped with a specific device, on which custom-made electrodes were fixed every 15 cm. The signals showed coherent perturbations during the drilling operations in the boreholes BEZ-G12 and in the end-face of the gallery Ga04. Afterwards, an early, strong but rather smooth increase of a few tens of mV, followed by a very slow decrease of much smallest amplitude, can be observed in some signals

  19. A tiny tick can cause a big health problem

    Directory of Open Access Journals (Sweden)

    Manuel John

    2017-01-01

    Full Text Available Ticks are tiny crawling bugs in the spider family that feed by sucking blood from animals. They are second only to mosquitoes as vectors of human disease, both infectious and toxic. Infected ticks spread over a hundred diseases, some of which are fatal if undetected. They spread the spirochete (which multiplies in the insect's gut with a subsequent bite to the next host. We describe the only reported cases of peri ocular tick bite from India that presented to us within a span of 3 days and its management. Due suspicion and magnification of the lesions revealed the ticks which otherwise masqueraded as small skin tags/moles on gross examination. The ticks were firmly latched on to the skin and careful removal prevented incarceration of the mouth parts. Rickettsial diseases that were believed to have disappeared from India are reemerging and their presence has recently been documented in at least 11 states in the country. Among vector borne diseases, the most common, Lyme disease, also known as the great mimicker, can present with rheumatoid arthritis, fibromyalgia, depression, attention deficit hyperactivity disorder, multiple sclerosis, chronic fatigue syndrome, cardiac manifestations, encephalitis, and mental illness, to name some of the many associations. Common ocular symptoms and signs include conjunctivitis, keratitis, uveitis, and retinitis. Early detection and treatment of tick borne diseases is important to prevent multi system complications that can develop later in life.

  20. Orchid bee (Hymenoptera: Apidae community from a gallery forest in the Brazilian Cerrado

    Directory of Open Access Journals (Sweden)

    Francinaldo S Silva

    2012-06-01

    Full Text Available The orchid bees are a very important group of pollinators distributed in the Neotropics. Although a lot of studies concerning male euglossine bees have been done in this region, few works have so far been carried out in the Cerrado biome. This manuscript has the main objective to present the orchid bee community from a Gallery Forest in the Northeastern Brazilian Cerrado landscape, taking account the species composition, abundance, seasonality and hourly distribution. Male euglossine bees were collected monthly from October 2007 to May 2009, in the Reserva Florestal da Itamacaoca belonging to the Companhia de Água e Esgoto do Maranhão, in Chapadinha municipality, Maranhão State. The scents eucalyptol, eugenol and vanillin were utilized, between 07:00 and 17:00hr, to attract the euglossine males. Cotton balls were dampened with the scents and suspended by a string on tree branches 1.5m above soil level, set 8m from one another. The specimens were captured with entomological nets, killed with ethyl acetate and transported to the laboratory to be identified. A total of 158 individuals and 14 species of bees were recorded. The genus Eulaema was the most representative group of euglossine bees in relation to the total number of the sampled individuals, accounting for 50.6% of bees followed by Euglossa (26.6%, Eufriesea (15.2% and Exaerete (7.6%. The most frequent species were Eulaema nigrita (27.8%, Eulaema cingulata (19% and Euglossa cordata (18.3%. Many species typical of forested environments were found in samples, like Euglossa avicula, Euglossa violaceifrons and Eulaema meriana, emphasizing the role played by the Gallery Forests as bridge sites to connect the two great biomes of Amazonia and Atlantic Forest. The occurrence of Exaerete guaykuru represents the second record of this species for the Neotropical region, and both records coming from the Gallery Forest zones. The male euglossine bees were sampled mainly in the dry season, where 62

  1. Tiny intraplate earthquakes triggered by nearby episodic tremor and slip in Cascadia

    Science.gov (United States)

    Vidale, J.E.; Hotovec, A.J.; Ghosh, A.; Creager, K.C.; Gomberg, J.

    2011-01-01

    Episodic tremor and slip (ETS) has been observed in many subduction zones, but its mechanical underpinnings as well as its potential for triggering damaging earthquakes have proven difficult to assess. Here we use a seismic array in Cascadia of unprecedented density to monitor seismicity around a moderate 16 day ETS episode. In the 4 months of data we examine, we observe five tiny earthquakes within the subducting slab during the episode and only one more in the same area, which was just before and nearby the next ETS burst. These earthquakes concentrate along the sides and updip edge of the ETS region, consistent with greater stress concentration there than near the middle and downdip edge of the tremor area. Most of the seismicity is below the megathrust, with a similar depth extent to the background intraslab seismicity. The pattern of earthquakes that we find suggests slow slip has a more continuous temporal and spatial pattern than the tremor loci, which notoriously appear in bursts, jumps, and streaks. Copyright 2011 by the American Geophysical Union.

  2. Laser heat stimulation of tiny skin areas adds valuable information to quantitative sensory testing in postherpetic neuralgia.

    Science.gov (United States)

    Franz, Marcel; Spohn, Dorothee; Ritter, Alexander; Rolke, Roman; Miltner, Wolfgang H R; Weiss, Thomas

    2012-08-01

    Patients suffering from postherpetic neuralgia often complain about hypo- or hypersensation in the affected dermatome. The loss of thermal sensitivity has been demonstrated by quantitative sensory testing as being associated with small-fiber (Aδ- and C-fiber) deafferentation. We aimed to compare laser stimulation (radiant heat) to thermode stimulation (contact heat) with regard to their sensitivity and specificity to detect thermal sensory deficits related to small-fiber dysfunction in postherpetic neuralgia. We contrasted detection rate of laser stimuli with 5 thermal parameters (thresholds of cold/warm detection, cold/heat pain, and sensory limen) of quantitative sensory testing. Sixteen patients diagnosed with unilateral postherpetic neuralgia and 16 age- and gender-matched healthy control subjects were tested. Quantitative sensory testing and laser stimulation of tiny skin areas were performed in the neuralgia-affected skin and in the contralateral homologue of the neuralgia-free body side. Across the 5 thermal parameters of thermode stimulation, only one parameter (warm detection threshold) revealed sensory abnormalities (thermal hypoesthesia to warm stimuli) in the neuralgia-affected skin area of patients but not in the contralateral area, as compared to the control group. In contrast, patients perceived significantly less laser stimuli both in the affected skin and in the contralateral skin compared to controls. Overall, laser stimulation proved more sensitive and specific in detecting thermal sensory abnormalities in the neuralgia-affected skin, as well as in the control skin, than any single thermal parameter of thermode stimulation. Thus, laser stimulation of tiny skin areas might be a useful diagnostic tool for small-fiber dysfunction. Copyright © 2012 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  3. Corrosion behavior of HPT-deformed TiNi alloys in cell culture medium

    Science.gov (United States)

    Shri, D. N. Awang; Tsuchiya, K.; Yamamoto, A.

    2017-09-01

    In recent years there are growing interest in fabrication of bulk nanostructured metals and alloys by using severe plastic deformation (SPD) techniques as new alternative in producing bulk nanocrystalline materials. These techniques allows for processing of bulk, fully dense workpiece with ultrafine grains. Metal undergoes SPD processing in certain techniques such as high pressure torsion (HPT), equal-channel angular pressing (ECAP) or multi-directional forging (MDF) are subjected to extensive hydrostatic pressure that may be used to impart a very high strain to the bulk solid without the introduction of any significant change in overall dimension of the sample. The change in the structure (small grain size and high-volume fraction of grain boundaries) of the material may result in the corrosion behavior different from that of the coarse-grained material. Electrochemical measurements were done to understand the corrosion behavior of TiNi alloys before and after HPT deformation. The experiment was carried out using standard three electrode setup (a sample as working electrode; a platinum wire as a counter electrode and a saturated calomel electrode in saturated KCl as a reference electrode) with the surface area of 26.42 mm2 exposed to the EMEM+10% FBS cell culture medium. The measurements were performed in an incubator with controlled environment at 37 °C and 5% CO2, simulating the cell culture condition. The potential of the specimen was monitored over 1 hour, and the stabilized potential was used as the open-circuit potential (EOCP). Potentiodynamic curves were scanned in the potential range from -0.5 V to 1.5 V relative to the EOCP, at a rate of 0.5 mV/s. The result of OCP-time measurement done in the cell culture medium shows that the OCP of HPT-deformed samples shifts towards to the more positive rather than that of BHPT samples. The OCP of deformed samples were ennobled to more than +70 mV for Ti-50mol%. The shift of OCP towards the nobler direction

  4. Effect of plastic strain on shape memory characteristics in sputter-deposited Ti-Ni thin films

    International Nuclear Information System (INIS)

    Nomura, K.

    1995-01-01

    The plastic strain which is introduced during cooling and heating under a constant stress has an influence upon the transformation and deformation characteristics of sputter-deposited Ti-Ni shape memory alloy thin films. With increasing the accumulated plastic strain, Ms rises and recovery strain increases. The changes in such characteristics are due to the internal stress field that is formed by plastic deformation. However, the change in Ms in Ti-50.5at%Ni is larger than that in Ti-48.9at%Ni, although the plastic strain in the former is lower than that in the latter. In order to understand this point, the effective internal stresses were estimated in both alloys; the internal stress in the former is more effectively created by the introduction of plastic strain than in the latter. (orig.)

  5. WHISPERS Project on the easternmost slope of the Ross Sea (Antarctica): preliminary results.

    Science.gov (United States)

    Olivo, E.; De Santis, L.; Bergamasco, A.; Colleoni, F.; Gales, J. A.; Florindo-Lopez, C.; Kim, S.; Kovacevic, V.; Rebesco, M.

    2017-12-01

    The advance and retreat of the West Antarctic Ice Sheet from the outer continental shelf and the oceanic circulation are the main causes of the depositional processes on the Ross Sea continental slope, at present time and during the most of the Cenozoic. Currently the Antarctic Bottom Water formation is directly linked to the relatively warm Circumpolar Deep Water that, encroaching the continental shelf, mixes with the colder Ross Sea Bottom Water. Detailed multibeam and geological surveys useful to locate and characterize peculiar morphological structures on the bottom are essential to study how the glacial and oceanographic processes interact with the seabed sediments. In the framework of the PNRA-WHISPERS project (XXXIIth Italian Antarctic expedition - January/March 2017), new multibeam bathymetric, sub-bottom chirp, were acquired from the easternmost margin of the Ross Sea, on the southeastern side of the Hayes Bank, usually covered by sea ice. We observed on the upper slope erosional features (incised gullies of likely glacial meltwater origin). A broad scar in the upper slope is characterized by an elongated SSW-NNE ridge (10 km long, 850-1200 m water depth, 2 km wide), that may be a remnants of previous glacial or debris flow deposits, eroded by meltwater outwash discharge at the beginning of grounding ice retreat and by RSBW cascading along the slope, as documented by Expandable Bathy-Thermograph and Acoustic Depth Current Profile data. Sub-bottom chirp profiles crossing this ridge show a very low amplitude reflective sea bed, supporting the hypothesis of its soft sediment nature, in good agreement with a very low acoustic velocity obtained by multichannel seismic data reprocessing. The occurrence of internal stratification on 2D multichannel seismic profiles would discount a gas-fluids related mud volcano origin. No sediment cores were collected, due to bad sea conditions and limited ship time, further data collection would be needed to fully understand

  6. A tiny short-legged bird from the early Oligocene of Poland

    Directory of Open Access Journals (Sweden)

    Bochenski Zbigniew M.

    2016-10-01

    Full Text Available We describe an articulated partial leg of an Oligocene bird. It is one of the smallest avian fossils ever recorded. Its slender and exceptionally short tarsometatarsus, hallux as long as the tarsometatarsus and stout moderately curved claws agree with stem-group Apodidae (swifts, stem-group Trochilidae (hummingbirds, and stem-group Upupidae/Phoeniculidae (hoopoes/woodhoopoes. Unfortunately, due to the poor preservation of the specimen its more precise affinities remain unresolved. The specimen differs in many details from all other tiny Palaeogene birds and therefore most probably it represents a new taxon but it is too fragmentary to describe it. It is just the twelfth avian fossil from the Oligocene marine deposits of the Outer Carpathians and Central Palaeogene Basin — a huge area that covers south-eastern Poland, north-eastern Czech Republic and northern Slovakia — and therefore it adds to our very limited knowledge on the avifauna of that region. The remains of land birds from Jamna Dolna and other sites of the region can be attributed to the general sea level fall at that time, which led to limitation of the connection with the open ocean and resulted in many shallow shoals, temporary islands and exposed dry land areas along the coast.

  7. Walk, Look, Remember: The Influence of the Gallery's Spatial Layout on Human Memory for an Art Exhibition.

    Science.gov (United States)

    Krukar, Jakub

    2014-09-01

    The spatial organisation of museums and its influence on the visitor experience has been the subject of numerous studies. Previous research, despite reporting some actual behavioural correlates, rarely had the possibility to investigate the cognitive processes of the art viewers. In the museum context, where spatial layout is one of the most powerful curatorial tools available, attention and memory can be measured as a means of establishing whether or not the gallery fulfils its function as a space for contemplating art. In this exploratory experiment, 32 participants split into two groups explored an experimental, non-public exhibition and completed two unanticipated memory tests afterwards. The results show that some spatial characteristics of an exhibition can inhibit the recall of pictures and shift the focus to perceptual salience of the artworks.

  8. Development and validation of a CFD model predicting the backfill process of a nuclear waste gallery

    International Nuclear Information System (INIS)

    Gopala, Vinay Ramohalli; Lycklama a Nijeholt, Jan-Aiso; Bakker, Paul; Haverkate, Benno

    2011-01-01

    Research highlights: → This work presents the CFD simulation of the backfill process of Supercontainers with nuclear waste emplaced in a disposal gallery. → The cement-based material used for backfill is grout and the flow of grout is modelled as a Bingham fluid. → The model is verified against an analytical solution and validated against the flowability tests for concrete. → Comparison between backfill plexiglas experiment and simulation shows a distinct difference in the filling pattern. → The numerical model needs to be further developed to include segregation effects and thixotropic behavior of grout. - Abstract: Nuclear waste material may be stored in underground tunnels for long term storage. The example treated in this article is based on the current Belgian disposal concept for High-Level Waste (HLW), in which the nuclear waste material is packed in concrete shielded packages, called Supercontainers, which are inserted into these tunnels. After placement of the packages in the underground tunnels, the remaining voids between the packages and the tunnel lining is filled-up with a cement-based material called grout in order to encase the stored containers into the underground spacing. This encasement of the stored containers inside the tunnels is known as the backfill process. A good backfill process is necessary to stabilize the waste gallery against ground settlements. A numerical model to simulate the backfill process can help to improve and optimize the process by ensuring a homogeneous filling with no air voids and also optimization of the injection positions to achieve a homogeneous filling. The objective of the present work is to develop such a numerical code that can predict the backfill process well and validate the model against the available experiments and analytical solutions. In the present work the rheology of Grout is modelled as a Bingham fluid which is implemented in OpenFOAM - a finite volume-based open source computational fluid

  9. Graphite-like carbon nitride coupled with tiny Bi2S3 nanoparticles as 2D/0D heterojunction with enhanced photocatalytic activity

    Science.gov (United States)

    Zhu, Chengzhang; Gong, Tingting; Xian, Qiming; Xie, Jimin

    2018-06-01

    Novel well-dispersed tiny Bi2S3 nanoparticles (NPs) with an average sizes of approximately 16.2 nm were used to decorate layered g-C3N4 nanosheets (NSs), with the purpose of constructing highly efficient 0D/2D heterojunction photocatalyst by a simple hydrothermal method in one step. The fabricated Bi2S3/g-C3N4 heterostructures exhibited superior visible-light-driven photocatalytic activity toward methyl orange (MO) degradation in contrast to that of individual Bi2S3 and g-C3N4, which could be mainly ascribed to the synergistic effect of the tiny size effect of 0D Bi2S3 NPs and 2D g-C3N4 NSs, the matched energy level positions, and the abundant coupling heterointerfaces between two moieties. More importantly, the photodegradation of methylene blue (MB), rhodamine B (RhB) and colorless tetracycline (TC), ciprofloxacin (CIP) further revealed the broad-spectrum photodegradation capacities of the heterojunction materials. The possible photoinduced charge transfer and pollutant degradation process over Bi2S3/g-C3N4 heterojunctions under visible-light irradiation were proposed. This work may provide a platform for constructing new visible light 0D/2D intimate contact heterostructures with stable and efficient photocatalytic performance.

  10. Development of and horizontal seams wining system by means of galleries and chambers; Demostracion de un Sistema de Explotacion de Capas Horizontales por el Metodo de Pilares y Galerias Trazadas Integramente con Maquinas de Ataque Puntual

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The project Development of an horizontal seams wining system by means of galleries and chambers aimed on the solution of a mining problem kept unresolved during the last 35 years in Carrasconte mine, owned by the society Minero Siderurgica de Ponferrada, in the coal yield of Villablino, Leon, Spain. The problem was a horizontal seam, with a width from 2,5 to 3,5 m, with two specific characteristics; one, roof and floor extremely rigid, with a 30 m sandstone stratum by roof that practically could highly restrict the long wall face conventional system, and the other, an intercalation of shale with a width of 1,2 m and a hardness of near 400 kg/cm2 that required a suitable winning system. By means of investigation with galleries carried out by continuous miners the real width of shale intercalation was stated, an then suitable systems adopted as this width varied. So, short wall faces in areas with minimum shale were disposed, and in t areas with maximum shale width, two long wall faces each one in each different vein were designed. At the end, the borders of reserves were recovered by the conventional system of galleries and chambers. This development project has allowed to recover more than a million tons in three years by systems suitable to the different conditions of the seam. (Author)

  11. Feasibility for Use of a Seabed Gallery Intake for the Shuqaiq-II SWRO Facility, Saudi Arabia

    KAUST Repository

    Mantilla, David

    2013-04-01

    Shuqaiq-II IWP is a combined RO water desalination and power plant facility. It operates with an open intake that feeds the plant with 100,000 m3/h of raw water. The facility is located 140 km north of Jizan, in a small bay where the run-off discharges of two wadis converge. The run-off coming from the wadis are rich in alluvial sediments that dramatically decrease the raw water quality at the intake point, causing periodic shutdowns of the plant and increasing the operational cost due to membrane replacement. Subsurface water intakes are an alternative for improving raw water quality, as they provide natural filtering of the feed water as it flows through the systems. In this type of system water flow through the sediment matrix is induced and during the percolation, several physical, chemical and biological processes take place, cleaning the water from particulate matter, resulting in high quality feed water that can be directly sent to the RO process without any additional pretreatment. A full hydrogeological profile of the seabed needs to be performed in order to determine the applicability of one of these systems in each particular location. In this study, 1 km of beach area at Shuqaiq-II IWP was surveyed. Ninety-one (91) samples from the shore and offshore sediments were collected and analyzed for hydraulic conductivity, porosity and grain size distribution. The laboratory analysis showed that the construction of the seabed galleries was technically feasible, and the proposed intake system was design to meet the feed water requirements for the RO facility (530.000 m3/d). The preliminary design consists of 17 cells in total, 16 of which will be in constant operation, and 1 alternate for whenever maintenance is needed in one of the other cells. The seabed gallery design includes 5 layers of sands with a total depth of 5 m. A detailed underdrain design methodology is presented. The system would be operated at an infiltration rate of 10 m/d and an average

  12. Transformation-Induced Relaxation and Stress Recovery of TiNi Shape Memory Alloy

    Directory of Open Access Journals (Sweden)

    Kohei Takeda

    2014-03-01

    Full Text Available The transformation-induced stress relaxation and stress recovery of TiNi shape memory alloy (SMA in stress-controlled subloop loading were investigated based on the local variation in temperature and transformation band on the surface of the tape in the tension test. The results obtained are summarized as follows. (1 In the loading process, temperature increases due to the exothermic martensitic transformation (MT until the holding strain and thereafter temperature decreases while holding the strain constant, resulting in stress relaxation due to the MT; (2 In the unloading process, temperature decreases due to the endothermic reverse transformation until the holding strain and thereafter temperature increases while holding the strain constant, resulting in stress recovery due to the reverse transformation; (3 Stress varies markedly in the initial stage followed by gradual change while holding the strain constant; (4 If the stress rate is high until the holding strain in the loading and unloading processes, both stress relaxation and stress recovery are large; (5 It is important to take into account this behavior in the design of SMA elements, since the force of SMA elements varies even if the atmospheric temperature is kept constant.

  13. Characterization and study of the behavior of wire Ti-Ni with shape memory effect enables manufacture of actuators; Estudo da caracterizacao e do comportamento de fios de Ti-Ni com efeito memoria de forma viabilizando fabricacao de atuadores

    Energy Technology Data Exchange (ETDEWEB)

    Pina, E.A.C.; Araujo Filho, O.O. de; Urtiga Filho, S.L.; Gonzalez, C.H., E-mail: kikipina@hotmail.co [Universidade Federal de Pernambuco (DEM/CTG/UFPE), Recife, PE (Brazil). Centro de Tecnologia e Geociencias. Dept. de Engenharia Mecanica

    2010-07-01

    This work aims to characterize the wire commercial Ti-Ni of 1.27 mm in diameter with shape memory effect for the development of helical springs with the function of sensor / actuator. After heat treatment, the transformation temperatures, the presence of precipitates, the degree of damping, maximum stress of rupture, modulus of elasticity, the presence of phase R, the behavior of the alloy under tension, will be analyzed and compared in each situation. For characterization we used several methods including: heat treatment, Differential Scanning Calorimetry (DSC), tensile, dynamic mechanical analysis (DMA), X-ray diffraction, thermomechanical cycling. The wires were cut into pieces and heat-treated at 400 deg C with variation of time in muffle furnaces and quenching in water at 25 deg C. (author)

  14. Biosensing by WGM Microspherical Resonators

    Directory of Open Access Journals (Sweden)

    Giancarlo C. Righini

    2016-06-01

    Full Text Available Whispering gallery mode (WGM microresonators, thanks to their unique properties, have allowed researchers to achieve important results in both fundamental research and engineering applications. Among the various geometries, microspheres are the simplest 3D WGM resonators; the total optical loss in such resonators can be extremely low, and the resulting extraordinarily high Q values of 108–109 lead to high energy density, narrow resonant-wavelength lines and a lengthy cavity ringdown. They can also be coated in order to better control their properties or to increase their functionality. Their very high sensitivity to changes in the surrounding medium has been exploited for several sensing applications: protein adsorption, trace gas detection, impurity detection in liquids, structural health monitoring of composite materials, detection of electric fields, pressure sensing, and so on. In the present paper, after a general introduction to WGM resonators, attention is focused on spherical microresonators, either in bulk or in bubble format, to their fabrication, characterization and functionalization. The state of the art in the area of biosensing is presented, and the perspectives of further developments are discussed.

  15. Optical Microcavity: Sensing down to Single Molecules and Atoms

    Directory of Open Access Journals (Sweden)

    Shu-Yu Su

    2011-02-01

    Full Text Available This review article discusses fundamentals of dielectric, low-loss, optical micro-resonator sensing, including figures of merit and a variety of microcavity designs, and future perspectives in microcavity-based optical sensing. Resonance frequency and quality (Q factor are altered as a means of detecting a small system perturbation, resulting in realization of optical sensing of a small amount of sample materials, down to even single molecules. Sensitivity, Q factor, minimum detectable index change, noises (in sensor system components and microcavity system including environments, microcavity size, and mode volume are essential parameters to be considered for optical sensing applications. Whispering gallery mode, photonic crystal, and slot-type microcavities typically provide compact, high-quality optical resonance modes for optical sensing applications. Surface Bloch modes induced on photonic crystals are shown to be a promising candidate thanks to large field overlap with a sample and ultra-high-Q resonances. Quantum optics effects based on microcavity quantum electrodynamics (QED would provide novel single-photo-level detection of even single atoms and molecules via detection of doublet vacuum Rabi splitting peaks in strong coupling.

  16. Creating tuneable microwave media from a two-dimensional lattice of re-entrant posts

    Energy Technology Data Exchange (ETDEWEB)

    Goryachev, Maxim; Tobar, Michael E. [ARC Centre of Excellence for Engineered Quantum Systems, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009 (Australia)

    2015-11-28

    The potential capabilities of resonators based on two dimensional arrays of re-entrant posts is demonstrated. Such posts may be regarded as magnetically coupled lumped element microwave harmonic oscillators, arranged in a 2D lattices structure, which is enclosed in a 3D cavity. By arranging these elements in certain 2D patterns, we demonstrate how to achieve certain requirements with respect to field localisation and device spectra. Special attention is paid to symmetries of the lattices, mechanical tuning, design of areas of high localisation of magnetic energy; this in turn creates unique discrete mode spectra. We demonstrate analogies between systems designed on the proposed platform and well known physical phenomena such as polarisation, frustration, and Whispering Gallery Modes. The mechanical tunability of the cavity with multiple posts is analysed, and its consequences to optomechanical applications is calculated. One particular application to quantum memory is demonstrated with a cavity design consisting of separate resonators analogous to discrete Fabry–Pérot resonators. Finally, we propose a generalised approach to a microwave system design based on the concept of Programmable Cavity Arrays.

  17. Nickel-doped (Zr0.8, Sn0.2)TiO4 for microwave and millimeter-wave applications

    International Nuclear Information System (INIS)

    Ioachim, A.; Banciu, M.G.; Toacsan, M.I.; Nedelcu, L.; Ghetu, D.; Alexandru, H.V.; Stoica, G.; Annino, G.; Cassettari, M.; Martinelli, M.

    2005-01-01

    (Zr 0.8 , Sn 0.2 )TiO 4 ternary compounds (ZST) have been prepared by conventional solid-state reaction from raw materials. The effects of such sintering parameters as sintering temperature, sintering time, and NiO addition on structural and dielectric properties were investigated. The material exhibits a dielectric constant ε r ∼36.0 and high values of the product Qf of the intrinsic quality factor Q and the frequency f from 32,170 to 50,000 at microwave frequencies. The dielectric loss tan δ values of ZST ceramics are decreased by low-level doping of NiO, while the temperature coefficient of the resonance frequency τ f takes values in the range -2 to +4 ppm/ deg. C. Investigations on whispering gallery modes revealed low dielectric loss in millimetre-wave domain. An intrinsic quality factor of 480 was measured at 115.6 GHz. Dielectric resonators and substrates of ZST material were manufactured. The dielectric properties make the ZST material very attractive to microwave and millimeter-wave applications, such as dielectric resonators, filters, planar antennas, hybrid microwave integrated circuits, etc

  18. Microfluidics and thin-film processes: a recipe for organic integrated photonics based on 3D microresonators

    Science.gov (United States)

    Huby, N.; Pluchon, D.; Belloul, M.; Moreac, A.; Coulon, N.; Gaviot, E.; Panizza, P.; B"che, B.

    2010-02-01

    We report on the design and realization of photonic integrated devices based on 3D organic microresonators. This has been achieved by combining microfluidics techniques and thin-film processes. The microfluidic device and the control of the flow rates of the continuous and dispersed phases allow the fabrication of organic microresonators with diameter ranging from 30 to 200 μm. The resonance of the sphere in air has been first investigated by using the Raman spectroscopy set-up demonstrating the appropriate photonic properties. Then the microresonators have been integrated on an organic chip made of the photosensitive resin SU-8 and positioned at the extremity of a taper and alongside a rib waveguide. The realization of these structures by thin-film processes needs one step UV-lithography leading to 6μm width and 30μm height. Both devices have proved the efficient evanescent coupling leading to the excitation of the whispering gallery modes confined at the surface of the organic 3D microresonators. Finally, a band-stop filter has been used to detect the resonance spectra of the resonators once integrated.

  19. Study of luminescence and optical resonances in Sb{sub 2}O{sub 3} micro- and nanotriangles

    Energy Technology Data Exchange (ETDEWEB)

    Cebriano, Teresa; Mendez, Bianchi, E-mail: bianchi@fis.ucm.es; Piqueras, Javier [Universidad Complutense de Madrid, Departamento de Fisica de Materiales, Facultad de Ciencias Fisicas (Spain)

    2012-10-15

    Luminescence of micro- and nanotriangles of cubic antimony oxide, Sb{sub 2}O{sub 3} has been investigated by cathodoluminescence (CL) in scanning electron microscope and by photoluminescence (PL) in a laser confocal microscope. The triangles were grown by a thermal evaporation-deposition process with pure antimony powders as precursor, and present a self assembled arrangement covering extended areas of the samples. CL spectra of the triangles show bands at 2-2.5 and 3.1 eV, the latter is not observed in the Sb{sub 2}O{sub 3} initial powder. PL excited by 325 nm laser shows a band at 2.4 eV with a shoulder at 2.75 eV, as well as resonance modes suggesting optical cavity behavior of the triangles. The separation between resonant peaks from different triangles has been correlated with the triangle side length and possible optical paths were obtained according to the Fabry-Perot relationship. These results along with the optical images suggest that not only Fabry-Perot cavity modes, but also whispering gallery modes may occur inside the micro- and nanotriangle structures.

  20. Miscellaneous Lasing Actions in Organo-Lead Halide Perovskite Films.

    Science.gov (United States)

    Duan, Zonghui; Wang, Shuai; Yi, Ningbo; Gu, Zhiyuan; Gao, Yisheng; Song, Qinghai; Xiao, Shumin

    2017-06-21

    Lasing actions in organo-lead halide perovskite films have been heavily studied in the past few years. However, due to the disordered nature of synthesized perovskite films, the lasing actions are usually understood as random lasers that are formed by multiple scattering. Herein, we demonstrate the miscellaneous lasing actions in organo-lead halide perovskite films. In addition to the random lasers, we show that a single or a few perovskite microparticles can generate laser emissions with their internal resonances instead of multiple scattering among them. We experimentally observed and numerically confirmed whispering gallery (WG)-like microlasers in polygon shaped and other deformed microparticles. Meanwhile, owing to the nature of total internal reflection and the novel shape of the nanoparticle, the size of the perovskite WG laser can be significantly decreased to a few hundred nanometers. Thus, wavelength-scale lead halide perovskite lasers were realized for the first time. All of these laser behaviors are complementary to typical random lasers in perovskite film and will help the understanding of lasing actions in complex lead halide perovskite systems.

  1. Creation of quantum entanglement with two separate diamond nitrogen vacancy centers coupled to a photonic molecule

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Siping [School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); School of Physics and Electronic Engineering, Hubei University of Arts and Science, Xiangyang 441053 (China); Yu, Rong, E-mail: rong-yu2013@163.com [School of Science, Hubei Province Key Laboratory of Intelligent Robot, Wuhan Institute of Technology, Wuhan 430073 (China); Li, Jiahua, E-mail: huajia-li@163.com [School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Key Laboratory of Fundamental Physical Quantities Measurement of Ministry of Education, Wuhan 430074 (China); Wu, Ying [School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2013-12-28

    We explore the entanglement generation and the corresponding dynamics between two separate nitrogen-vacancy (NV) centers in diamond nanocrystal coupled to a photonic molecule consisting of a pair of coupled photonic crystal (PC) cavities. By calculating the entanglement concurrence with readily available experimental parameters, it is found that the entanglement degree strongly depends on the cavity-cavity hopping strength and the NV-center-cavity detuning. High concurrence peak and long-lived entanglement plateau can be achieved by properly adjusting practical system parameters. Meanwhile, we also discuss the influence of the coupling strength between the NV centers and the cavity modes on the behavior of the concurrence. Such a PC-NV system can be employed for quantum entanglement generation and represents a building block for an integrated nanophotonic network in a solid-state cavity quantum electrodynamics platform. In addition, the present theory can also be applied to other similar systems, such as two single quantum emitters positioned close to a microtoroidal resonator with the whispering-gallery-mode fields propagating inside the resonator.

  2. L’astronomia gravitazionale: in ascolto dei sussurri dell’universo

    Directory of Open Access Journals (Sweden)

    ALLOCCA, ANNALISA

    2017-12-01

    Full Text Available Gravitational astronomy: listening to the whispers of the universe It was about 10 am, Greenwich time, on September 14th 2015 when scientists detected something which had never been detected before: the “sound” of two colliding black holes which, after orbiting around each other for billion years, approached closer and closer until colliding, giving rise to a single huge black hole. A tiny fraction of second before the collision, they sent a signal towards the rest of the universe, their “swansong”, a vibration which propagated in space and time at the speed of light, getting to the Earth 1.4 billion years later. A gravitational wave. A hundred years after the publication of the General Relativity, the Gravitational Waves detection confirms once again the validity of Einstein’s Theory, and paves the way for a completely new research field. Space-time ripples poorly interacting with matter and giving rise to extremely tiny effects, Gravitational Waves need very sophisticated instruments to be detected. In this paper we will retrace the history of this discovery, starting from the breath of revolution of General Relativity which carries along the theorization of Gravitational Wave. We will then go through the analysis of the effect that Gravitational Waves induce on the matter, and we will describe the basic principles of the instrument which detected them, to finally get to the first discovery which opens the way to a completely new era for astronomy.

  3. Tiny individuals attached to a new Silurian arthropod suggest a unique mode of brood care

    Science.gov (United States)

    Briggs, Derek E. G.; Siveter, Derek J.; Siveter, David J.; Sutton, Mark D.

    2016-04-01

    The ˜430-My-old Herefordshire, United Kingdom, Lagerstätte has yielded a diversity of remarkably preserved invertebrates, many of which provide fundamental insights into the evolutionary history and ecology of particular taxa. Here we report a new arthropod with 10 tiny arthropods tethered to its tergites by long individual threads. The head of the host, which is covered by a shield that projects anteriorly, bears a long stout uniramous antenna and a chelate limb followed by two biramous appendages. The trunk comprises 11 segments, all bearing limbs and covered by tergites with long slender lateral spines. A short telson bears long parallel cerci. Our phylogenetic analysis resolves the new arthropod as a stem-group mandibulate. The evidence suggests that the tethered individuals are juveniles and the association represents a complex brooding behavior. Alternative possibilities—that the tethered individuals represent a different epizoic or parasitic arthropod—appear less likely.

  4. Sulla digitalizzazione della street art. Linee guida per un'analisi del museo virtuale Reggiane Urban Gallery

    Directory of Open Access Journals (Sweden)

    Damiano Razzoli

    2017-09-01

    Full Text Available Reggiane Urban Gallery is a virtual museum based on the abandoned industrial plant of ex-Officine Reggiane in Reggio Emilia, now in restoration. Along the years the place has become an open space for local and national street-artists. The aim of this paper is to analyze the use of virtual reality and navigable interface as a solution for the conservation of the Street Art, in relation to the fact that many pieces would have been lost due to the demolition of several walls. Also, the analysis proposes guidelines for a digitalization of Street Art that could prevent the displacement of situated Street Art pieces in museums and encourage the creation of street art locative media museum, supported on four concepts - dispositive/device, locativity, topographic database, interface - and one discoursive feature designing the mediated experience of urban crossing practices: the mimetical relation between the software cultural components and Street Art.

  5. Surface tiny grain-dependent enhanced rate performance of MoO3 nanobelts with pseudocapacitance contribution for lithium-ion battery anode

    Science.gov (United States)

    Cao, Liyun; He, Juju; Li, Jiayin; Yan, Jingwen; Huang, Jianfeng; Qi, Ying; Feng, Liangliang

    2018-07-01

    In order to improve the rate performance of MoO3, a novel MoO3 nanobelt with tiny grains on surface (named as d-MoO3) is fabricated via one-step facile hydrothermal method with citric acid adding, in which citric acid (CA) serves as a weak reductant as well as surface modification agent. When tested as an anode in LIBs, d-MoO3 displays an improved discharge capacity of 787 mAh·g-1 at 0.1 A g-1 over 100 cycles with capacity retention of ∼91% while MoO3 decays to 50 mAh·g-1 in the 100th cycle. Notably, d-MoO3 delivers enhanced rate capability (536 and 370 mAh·g-1 at high rates of 5 and 10 A g-1 respectively). We consider these excellent electrochemical properties of d-MoO3 electrode are associated with the tiny grains on MoO3 surface, which effectively maintains the electrode's structural integrity. Even though d-MoO3 nanobelt suffers from a degree of in-situ pulverization after several cycles, these pulverized active particles can still maintain stable electrochemical contact and are highly exposed to electrolyte, realizing ultrahigh e-/Li+ diffusion kinetics. In addition, part extrinsic pseudocapacitance contribution to the Li+ storage also explains the high-rate performance. Combining all these merits, d-MoO3 is potentially a high-energy, high-power and well-stable anode material for Li ion batteries (LIBs).

  6. An Improved Task Scheduling Algorithm for Intelligent Control in Tiny Mechanical System

    Directory of Open Access Journals (Sweden)

    Jialiang Wang

    2014-01-01

    Full Text Available Wireless sensor network (WSN has been already widely used in many fields in terms of industry, agriculture, and military, and so forth. The basic composition is WSN nodes that are capable of performing processing, gathering information, and communicating with other connected nodes in the network. The main components of a WSN node are microcontroller, transceiver, and some sensors. Undoubtedly, it also can be added with some actuators to form a tiny mechanical system. Under this case, the existence of task preemption while executing operating system will not only cost more energy for WSN nodes themselves, but also bring unacceptable system states caused by vibrations. However for these nodes, task I/O delays are inevitable due to the existence of task preemption, which will bring extra overhead for the whole system, and even bring unacceptable system states caused by vibrations. This paper mainly considers the earliest deadline first (EDF task preemption algorithm executed in WSN OS and proposes an improved task preemption algorithm so as to lower the preemption overhead and I/O delay and then improve the system performance. The experimental results show that the improved task preemption algorithm can reduce the I/O delay effectively, so the real-time processing ability of the system is enhanced.

  7. Desaturation of a clay-stone around a ventilated gallery: numerical modelling of pressures and water contents under various conditions

    International Nuclear Information System (INIS)

    Ababou, Rachid; Mansouri, Nahla; Bailly, David; Poutrel, Adrien

    2012-01-01

    Document available in extended abstract form only. We present simulation tests focusing on the drying process around a gallery in an initially saturated (water-filled) porous clay rock, in the framework of a research on the isolation properties and hydro-mechanical behaviour of a clayey geologic repository for radioactive waste. The saturated/unsaturated hydrodynamic parameters used in these tests correspond to a hypothetical clay-stone, similar to the 130 m thick Callovo-Oxfordian formation located between depths 400 m and 600 m at the Meuse / Haute-Marne (MHM) Underground Research Laboratory (URL), operated by ANDRA (Bure, France). The simulations tests were designed according to 3 'types' of computational geometries. The drying period was extended to very long time scales in some cases. The clay rock was taken homogeneous in many tests, but the damaged zone was represented in some (Type III) tests. Type (I) tests are conducted in a simplified non circular geometry. Assuming a square cross-section for the drift, the drying process is obtained by imposing a fixed suction on a flat piece of wall at the roof. The bottom of the porous domain coincides with the roof of the drift. The imposed suction at the roof affects the near field pressure both horizontally and vertically. Type (II) tests reproduce the circular cylindrical geometry of a partially or perfectly filled gallery, with drying conditions imposed at both ends of the drift. Finally, Type (III) tests consider the case of an empty ventilated cylindrical drift with circular cross-section. In this case the drying is imposed on the curved walls of the drift via a transmission mechanism thanks the 'macro-porous immersion' method. In all cases, the drying of the porous clay rock is modeled by imposing a suction condition (ψ), obtained from relative air humidity (HR) via Kelvin's law (ψ). Briefly, the macro-porous immersion method consists in the following interrelated procedures. First, the volumetric excavation

  8. Enhanced water collection through a periodic array of tiny holes in dropwise condensation

    Science.gov (United States)

    Song, Kyungjun; Kim, Gyeonghee; Oh, Sunjong; Lim, Hyuneui

    2018-02-01

    This paper introduces a simple method of water collection by increasing the coalescence effects in dropwise condensation with the use of microscale holes. The tiny holes modified the surface free energy states of the droplets on the plate, yielding a surface free energy barrier between the flat solid surface and the holes. The spatial difference in the surface free energy of the droplets enabled the droplets to move toward the adjacent droplets, thus increasing the possibility of coalescence. The water collection experiments were performed using a Peltier-based cooling system at 2 °C inside a chamber at 30 °C and 70% humidity. The results demonstrated that the perforated plates without any additional treatment provided the water collection rate of up to 22.64 L/m2 day, which shows an increase of 30% compared to that demonstrated by the bare plate. By comparing the experimental results for the surface of filmwise condensation, it was proved that the dominant water collecting improvement results from the increased coalescence effects. This simple technique can enhance the performance of systems exposed to water condensation, including water collection, heat-transfer, and dehumidifying systems.

  9. Seabed gallery intakes: Investigation of the water pretreatment effectiveness of the active layer using a long-term column experiment

    KAUST Repository

    Dehwah, Abdullah

    2017-05-11

    Seabed gallery intake systems used for seawater reverse osmosis facilities employ the same principle of water treatment as slow sand filtration in freshwater systems. An investigation concerning the effectiveness of the active layer (top layer) in improving raw water quality was conducted by using a long-term bench-scale columns experiment. Two different media types, silica and carbonate sand, were tested in 1 m columns to evaluate the effectiveness of media type in terms of algae, bacteria, Natural Organic Matter (NOM) and Transparent Exopolymer Particles (TEP) removal over a period of 620 days. Nearly all algae in the silica sand column, 87% (σ = 0.04) of the bacteria, 59% (σ = 0.11) of the biopolymer fraction of NOM, 59% (σ = 0.16) of particulate and 32% (σ = 0.25) of colloidal TEP were removed during the last 330 days of the experiment. Total removal was observed in the carbonate sand column for algal concentration, while the bacterial removal was lower at 74% (σ = 0.08). Removal of biopolymers, particulate and colloidal TEP were higher in the carbonate column during the last 330 days with 72% (σ = 0.15), 66% (σ = 0.08) and 36% (σ = 0.12) removed for these organics respectively. Removal of these key organics through the 1 m thick column, representing the active layer, will likely reduce the rate of biofouling, reduce chemical usage and minimize operating cost in SWRO systems. The data show that the media will require several months at the beginning of operation to reach equilibrium so that high organic removal rates can be achieved. No development of a “schmutzdecke” layer occurred. The experimental results suggest that unlike freshwater slow sand filtration wherein most water treatment occurs in the upper 10 cm, in seawater systems treatment occurs throughout the full active layer depth of 1 m. The results of this study will help in designing and operating seabed gallery intake systems in varied geological conditions.

  10. Parallel inversion of a massive ERT data set to characterize deep vadose zone contamination beneath former nuclear waste infiltration galleries at the Hanford Site B-Complex (Invited)

    Science.gov (United States)

    Johnson, T.; Rucker, D. F.; Wellman, D.

    2013-12-01

    The Hanford Site, located in south-central Washington, USA, originated in the early 1940's as part of the Manhattan Project and produced plutonium used to build the United States nuclear weapons stockpile. In accordance with accepted industrial practice of that time, a substantial portion of relatively low-activity liquid radioactive waste was disposed of by direct discharge to either surface soil or into near-surface infiltration galleries such as cribs and trenches. This practice was supported by early investigations beginning in the 1940s, including studies by Geological Survey (USGS) experts, whose investigations found vadose zone soils at the site suitable for retaining radionuclides to the extent necessary to protect workers and members of the general public based on the standards of that time. That general disposal practice has long since been discontinued, and the US Department of Energy (USDOE) is now investigating residual contamination at former infiltration galleries as part of its overall environmental management and remediation program. Most of the liquid wastes released into the subsurface were highly ionic and electrically conductive, and therefore present an excellent target for imaging by Electrical Resistivity Tomography (ERT) within the low-conductivity sands and gravels comprising Hanford's vadose zone. In 2006, USDOE commissioned a large scale surface ERT survey to characterize vadose zone contamination beneath the Hanford Site B-Complex, which contained 8 infiltration trenches, 12 cribs, and one tile field. The ERT data were collected in a pole-pole configuration with 18 north-south trending lines, and 18 east-west trending lines ranging from 417m to 816m in length. The final data set consisted of 208,411 measurements collected on 4859 electrodes, covering an area of 600m x 600m. Given the computational demands of inverting this massive data set as a whole, the data were initially inverted in parts with a shared memory inversion code, which

  11. The splicing of tiny introns of Paramecium is controlled by MAGO.

    Science.gov (United States)

    Contreras, Julia; Begley, Victoria; Marsella, Laura; Villalobo, Eduardo

    2018-07-15

    The exon junction complex (EJC) is a key element of the splicing machinery. The EJC core is composed of eIF4A3, MAGO, Y14 and MLN51. Few accessory proteins, such as CWC22 or UPF3, bind transiently to the EJC. The EJC has been implicated in the control of the splicing of long introns. To ascertain whether the EJC controls the splicing of short introns, we used Paramecium tetraurelia as a model organism, since it has thousands of very tiny introns. To elucidate whether EJC affects intron splicing in P. tetraurelia, we searched for EJC protein-coding genes, and silenced those genes coding for eIF4A3, MAGO and CWC22. We found that P. tetraurelia likely assembles an active EJC with only three of the core proteins, since MLN51 is lacking. Silencing of eIF4A3 or CWC22 genes, but not that of MAGO, caused lethality. Silencing of the MAGO gene caused either an increase, decrease, or no change in intron retention levels of some intron-containing mRNAs used as reporters. We suggest that a fine-tuning expression of EJC genes is required for steady intron removal in P. tetraurelia. Taking into consideration our results and those published by others, we conclude that the EJC controls splicing independently of the intron size. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Effects of nearshore evaporation rates on the design of seabed gallery intake systems for SWRO facilities located along the Red Sea shoreline of Saudi Arabia

    KAUST Repository

    Dehwah, Abdullah

    2015-10-12

    Feed water to seawater reverse osmosis desalination systems should have a constant salinity with minimal variation. Intake systems that extract water from shallow nearshore areas in arid regions can exhibit significant fluctuations in salinity caused by high rates of evaporation and lack of circulation. Such fluctuations in salinity could inhibit the design, construction, and operation of seabed gallery intake systems located in shallow nearshore areas, such as the Red Sea inner shelf. Water depths range from 0 to 2 m between the beach and the edge of the fringing reef in the optimal locations for the development of seabed gallery intakes along the coast of the Red Sea of Saudi Arabia. The evaporation rate in this area is between 2 and 3 m per year. The bottom consists of mostly a marine hardground containing a thin veneer of unlithified sediment and no significant cover of corals or seagrass. The rather barren nature of the bottom suggests that periodic hypersalinity may contribute to the formation of hardgrounds on the bottom by causing supersaturation of the seawater with calcium carbonate and may limit the growth of corals and grasses. To assess the changes in salinity, a conceptual model was developed which assumes that a shallow circulation cell develops between the shoreline and deeper water offshore. Lower salinity seawater should migrate landward to replace water loss caused by evaporation with seaward moving of high-salinity water occurring along the bottom to balance the flow with ultimate mixing before the reef tract. To test this circulation pattern, a series of sensors were deployed to continuously monitor the water temperature, conductivity, and salinity at the surface and at the bottom during several periods of high air temperature. Surprisingly, the results show very little variation in salinity, despite the very high evaporation loss. The water salinity ranged between 39,000 and 40,000 mg/L with no diurnal variations of significance. Based on the

  13. Characterization and study of the behavior of wire Ti-Ni with shape memory effect enables manufacture of actuators

    International Nuclear Information System (INIS)

    Pina, E.A.C.; Araujo Filho, O.O. de; Urtiga Filho, S.L.; Gonzalez, C.H.

    2010-01-01

    This work aims to characterize the wire commercial Ti-Ni of 1.27 mm in diameter with shape memory effect for the development of helical springs with the function of sensor / actuator. After heat treatment, the transformation temperatures, the presence of precipitates, the degree of damping, maximum stress of rupture, modulus of elasticity, the presence of phase R, the behavior of the alloy under tension, will be analyzed and compared in each situation. For characterization we used several methods including: heat treatment, Differential Scanning Calorimetry (DSC), tensile, dynamic mechanical analysis (DMA), X-ray diffraction, thermomechanical cycling. The wires were cut into pieces and heat-treated at 400 deg C with variation of time in muffle furnaces and quenching in water at 25 deg C. (author)

  14. Heat treatments and thermomechanical cycling influences on the R-phase in Ti-Ni shape memory alloys

    Directory of Open Access Journals (Sweden)

    Cezar Henrique Gonzalez

    2010-09-01

    Full Text Available This article studies changes observed on the R-phase thermoelastic behavior in a near-equiatomic Ti-Ni shape memory alloy. Three kinds of procedures have been performed: different treatments, thermomechanical cycling under constant loading in shape memory helical springs and thermal cycling in as-treated and trained samples. Several heat treatments were carried out to investigate evolution of the R-phase by differential scanning calorimetry (DSC. A heat treatment was chosen on which R-phase is absent. Shape memory springs were produced and submitted to a training process in an apparatus by tensioning the springs under constant loading. Thermal cycling in DSC was realized in as-treated and trained samples. Several aspects of one-step (B2→B19' and two-steps (B2→R→B19' martensitic transformations and R-phase formation and their evolution during tests were observed and discussed.

  15. Thermal Stability of Clay's Galleries in Polypropylene - Clay (montmorillonite Nanocomposites using Polypropylene-gMaleic Anhydride as Compatibilizer

    Directory of Open Access Journals (Sweden)

    Sotya Astutiningsih

    2010-10-01

    Full Text Available Superior properties of food packaging can be achieved using nanocomposite technology. However, fabrication of this materials are complex and expensive. Long term objectives of this research is the synthesis of low cost polypropylene clay nanocomposites (PPCN via a short-cut method known as ‘cascade engineering’. Cascade engineering principle in PPCN fabrication is performed by using compatibilizer (to enable the mixing of PP and clay masterbatch, and PPCN in one pot process using melt mixer. This paper present the experimental results using small-angle x-ray diffraction (XRD on the thermal stability of the PPCN. Results from the XRD analysis showed that the clay was intercalated, however no significant changes were observed as a result of variation in mixing time. XRD patterns of the annealed PPCN showed reduction of MMT’s gallery (deintercalation These phenomenon was probably caused by insufficient bonding and lack of compatibility between PP-g-MA and MMT.

  16. A high-stability scanning tunneling microscope achieved by an isolated tiny scanner with low voltage imaging capability

    Science.gov (United States)

    Wang, Qi; Hou, Yubin; Wang, Junting; Lu, Qingyou

    2013-11-01

    We present a novel homebuilt scanning tunneling microscope (STM) with high quality atomic resolution. It is equipped with a small but powerful GeckoDrive piezoelectric motor which drives a miniature and detachable scanning part to implement coarse approach. The scanning part is a tiny piezoelectric tube scanner (industry type: PZT-8, whose d31 coefficient is one of the lowest) housed in a slightly bigger polished sapphire tube, which is riding on and spring clamped against the knife edges of a tungsten slot. The STM so constructed shows low back-lashing and drifting and high repeatability and immunity to external vibrations. These are confirmed by its low imaging voltages, low distortions in the spiral scanned images, and high atomic resolution quality even when the STM is placed on the ground of the fifth floor without any external or internal vibration isolation devices.

  17. A high-stability scanning tunneling microscope achieved by an isolated tiny scanner with low voltage imaging capability

    International Nuclear Information System (INIS)

    Wang, Qi; Wang, Junting; Lu, Qingyou; Hou, Yubin

    2013-01-01

    We present a novel homebuilt scanning tunneling microscope (STM) with high quality atomic resolution. It is equipped with a small but powerful GeckoDrive piezoelectric motor which drives a miniature and detachable scanning part to implement coarse approach. The scanning part is a tiny piezoelectric tube scanner (industry type: PZT-8, whose d 31 coefficient is one of the lowest) housed in a slightly bigger polished sapphire tube, which is riding on and spring clamped against the knife edges of a tungsten slot. The STM so constructed shows low back-lashing and drifting and high repeatability and immunity to external vibrations. These are confirmed by its low imaging voltages, low distortions in the spiral scanned images, and high atomic resolution quality even when the STM is placed on the ground of the fifth floor without any external or internal vibration isolation devices

  18. A high-stability scanning tunneling microscope achieved by an isolated tiny scanner with low voltage imaging capability.

    Science.gov (United States)

    Wang, Qi; Hou, Yubin; Wang, Junting; Lu, Qingyou

    2013-11-01

    We present a novel homebuilt scanning tunneling microscope (STM) with high quality atomic resolution. It is equipped with a small but powerful GeckoDrive piezoelectric motor which drives a miniature and detachable scanning part to implement coarse approach. The scanning part is a tiny piezoelectric tube scanner (industry type: PZT-8, whose d31 coefficient is one of the lowest) housed in a slightly bigger polished sapphire tube, which is riding on and spring clamped against the knife edges of a tungsten slot. The STM so constructed shows low back-lashing and drifting and high repeatability and immunity to external vibrations. These are confirmed by its low imaging voltages, low distortions in the spiral scanned images, and high atomic resolution quality even when the STM is placed on the ground of the fifth floor without any external or internal vibration isolation devices.

  19. Berenty Reserve—A Gallery Forest in Decline in Dry Southern Madagascar—Towards Forest Restoration

    Directory of Open Access Journals (Sweden)

    Vanessa Winchester

    2018-01-01

    Full Text Available Berenty Reserve, a fully protected gallery forest beside the Mandrare River is renowned for its lemurs, but the continuous canopy of the main forest is shrinking, fragmenting and degrading. The aim of this study, before any restoration can be considered, is to investigate why canopy-cover is declining and define the forest’s vegetation status and composition. Our study includes analysis of tamarind age (the dominant species and regeneration, forest extent, climate and soil. Measurement of trunk circumference and annual rings indicated a median age of 190 years, near the accepted maximum for tamarinds. There is no regeneration of tamarind seedlings under the canopy and an invasive vine, Cissus quadrangularis suffocates any regeneration on the forest margins. A vegetation survey, based on fifteen transects, broadly characterized three forest areas: continuous canopy near the river, transitional canopy with fewer tall trees, and degraded dryland; the survey also provided a list of the 18 most common tree species. Ring counts of flood-damaged roots combined with measurement to the riverbank show that erosion rates, up to 19.5 cm/year, are not an immediate threat to forest extent. The highly variable climate shows no trend and analysis of forest soil indicates compatibility with plant growth.

  20. Quadrupolar order, hidden octupolar order and tiny magnetic moment in URu2Si2

    International Nuclear Information System (INIS)

    Tsuruta, Atsushi; Matsuura, Tamifusa; Kuroda, Yoshihiro

    2000-01-01

    Possible orders in URu 2 Si 2 are investigated using a two-channel degenerate Anderson model. The ground state of uranium ions is the non-Kramers quadrupolar doublet Γ 5 with (5f) 2 , and its relevant excited state is the Kramers dipolar doublet Γ 7 with (5f) 1 . These states mix with each other via conduction electrons. At low temperatures, the system forms renormalized bands with both quadrupole and dipole degrees of freedom due to the quadrupolar Kondo effect which slightly mixes quadrupolar Γ 5 , a primary state of uranium ions, with dipolar Γ 7 . At a certain low temperature, conduction electrons in the renormalized bands undergo quadrupolar ordering with a large quadrupolar moment. At a further lower temperature, octupolar ordering occurs, accompanied by a tiny dipolar moment which is attributed to the property of the renormalized bands with primarily the Γ 5 -character slightly mixed with the Γ 7 -character. These phenomena are well described by the 1/N-expansion method with pseudo-fermions for the non-Kramers doublet Γ 5 and slave bosons for the Kramers doublet Γ 7 . (author)

  1. Existence and switching behavior of bright and dark Kerr solitons in whispering-gallery mode resonators with zero group-velocity dispersion

    Science.gov (United States)

    Talla Mbé, Jimmi H.; Milián, Carles; Chembo, Yanne K.

    2017-07-01

    We use the generalized Lugiato-Lefever model to investigate the phenomenon of Kerr optical frequency comb generation when group-velocity dispersion is null. In that case, the first dispersion term that plays a leading role is third-order dispersion. We show that this term is sufficient to allow for the existence of both bright and dark solitons. We identify the areas in the parameter space where both kind of solitons can be excited inside the resonator. We also unveil a phenomenon of hysteretic switching between these two types of solitons when the power of the pump laser is cyclically varied. Contribution to the Topical Issue "Theory and Applications of the Lugiato-Lefever Equation", edited by Yanne K. Chembo, Damia Gomila, Mustapha Tlidi, Curtis R. Menyuk.

  2. Students, teachers and technicians are installing a cosmic ray detector in the CMS visitor gallery. The detector was designed and built in the framework of the US Quarknet project under the supervision of physicists from the Notre Dame University (USA)

    CERN Document Server

    Claudia Marcelloni

    2007-01-01

    Students, teachers and technicians are installing a cosmic ray detector in the CMS visitor gallery. The detector was designed and built in the framework of the US Quarknet project under the supervision of physicists from the Notre Dame University (USA)

  3. Fitossociologia de dois trechos inundáveis de Matas de Galeria no Distrito Federal, Brasil Phytosociology of two swamped portions of gallery forests in Distrito Federal, Brazil

    Directory of Open Access Journals (Sweden)

    Ernestino de Souza Gomes Guarino

    2005-09-01

    Full Text Available As Matas de Galeria do bioma Cerrado possuem peculiaridades fisionômicas e florísticas que permitem separá-las em dois subtipos: "não-inundável", quando em solos bem drenados; e "inundável", o subtipo menos estudado, em solos mal drenados. O presente trabalho objetivou caracterizar estrutural e floristicamente dois trechos inundáveis das matas dos córregos Acampamento (15°35'S; 48°10'W e Riacho Fundo (15°55'S; 48°02'W no Distrito Federal (DF. Para isso foi alocada em cada Mata uma grade de 160×50 m (0,8 ha, composta por 40 parcelas de 10×20 m (200 m². Todos os indivíduos com diâmetro a 1,30 m da altura do solo (DAP > 3,0 cm foram amostrados, incluindo aqueles mortos ainda em pé. Foram amostrados 6.078 indivíduos, sendo 3.030 no trecho do Acampamento (33 famílias, 49 gêneros e 60 espécies e 3.048 no Riacho Fundo (30 famílias, 41 gêneros, 53 espécies. A área basal e a diversidade (H' calculada para os trechos foram de 47,96 m²/ha e 2,99 nats/ind. (Acampamento, e 41,28 m²/ha e 2,84 nats/ind. (Riacho Fundo, respectivamente. Se comparados com matas anteriormente estudadas no DF os valores de diversidade são baixos, estando na mesma magnitude indicada para as Matas de Brejo (Higrófilas do sudeste brasileiro. Os índices de similaridade indicaram alta semelhança qualitativa (Sørensen 58,0% e quantitativa (Morisita 70,6% entre os trechos estudados, embora uma classificação por TWINSPAN tenha gerado dois grupos distintos, cada qual vinculado a um dos trechos. Os resultados reforçam indicações anteriores de que as Matas de Galeria do DF, ou trechos similares destas, inundáveis ou não, possuem comunidades arbóreas particulares, as quais estão relacionadas à bacia hidrográfica na qual a Mata esta inserida e ao padrão determinante da drenagem do solo.Gallery forests in the Cerrado biome possess physiognomic and floristic peculiarities that allow its division in two subtypes: "non-swamp" located in well drained

  4. Temporal Dynamics and Resource Availability for Drosophilid Fruit Flies (Insecta, Diptera in a Gallery Forest in the Brazilian Savanna

    Directory of Open Access Journals (Sweden)

    Henrique Valadão

    2010-01-01

    Full Text Available Seasonality can cause severe bottlenecks in natural populations, even leading to local extinction. Large variation in resource availability may explain the bottlenecks, but the role of these variations is still poorly understood. The goal of this study was to analyze if temporal variations in the guild of drosophilids breeding in fruits of Mauritia flexuosa (Arecaceae can be explained by the shortage of this resource during the dry season. Fruits of M. flexuosa were collected over one year in a gallery forest located in the Central Brazilian Savanna. The drosophilid assemblage varied over time, with a lower density of species and of individuals in the dry season, when the percentage of colonized fruits was also smaller. These findings suggest that although the fruits were available during the dry season, they were underused. This way, the resource availability does not seem to regulate the community in the dry season.

  5. Temporal Dynamics and Resource Availability for Drosophilid Fruit Flies (Insect, Diptera) in a Gallery Forest in the Brazilian Savanna

    International Nuclear Information System (INIS)

    Valadao, H.; Du Vall Hay, J.; Tidon, R.

    2010-01-01

    Seasonality can cause severe bottlenecks in natural populations, even leading to local extinction. Large variation in resource availability may explain the bottlenecks, but the role of these variations is still poorly understood. The goal of this study was to analyze if temporal variations in the guild of drosophilids breeding in fruits of Mauritia flexuosa (Arecaceae) can be explained by the shortage of this resource during the dry season. Fruits of M. flexuosa were collected over one year in a gallery forest located in the Central Brazilian Savanna. The drosophilid assemblage varied over time, with a lower density of species and of individuals in the dry season, when the percentage of colonized fruits was also smaller. These findings suggest that although the fruits were available during the dry season, they were under used. This way, the resource availability does not seem to regulate the community in the dry season.

  6. Hollow spheres: crucial building blocks for novel nanostructures and nanophotonics

    Directory of Open Access Journals (Sweden)

    Zhong Kuo

    2018-03-01

    Full Text Available In this review, we summarize the latest developments in research specifically derived from the unique properties of hollow microspheres, in particular, hollow silica spheres with uniform shells. We focus on applications in nanosphere (colloidal lithography and nanophotonics. The lithography from a layer of hollow spheres can result in nanorings, from a multilayer in unique nano-architecture. In nanophotonics, disordered hollow spheres can result in antireflection coatings, while ordered colloidal crystals (CCs of hollow spheres exhibit unique refractive index enhancement upon infiltration, ideal for optical sensing. Furthermore, whispering gallery mode (WGM inside the shell of hollow spheres has also been demonstrated to enhance light absorption to improve the performance of solar cells. These applications differ from the classical applications of hollow spheres, based only on their low density and large surface area, such as catalysis and chemical sensing. We provide a brief overview of the synthesis and self-assembly approaches of the hollow spheres. We elaborate on their unique optical features leading to defect mode lasing, optomicrofluidics, and the existence of WGMs inside shell for light management. Finally, we provide a perspective on the direction towards which future research relevant to hollow spheres might be directed.

  7. Super low threshold plasmonic WGM lasing from an individual ZnO hexagonal microrod on an Au substrate for plasmon lasers.

    Science.gov (United States)

    Dong, H M; Yang, Y H; Yang, G W

    2015-03-05

    We demonstrate an individual ZnO hexagonal microrod on the surface of an Au substrate which can become new sources for manufacturing miniature ZnO plasmon lasers by surface plasmon polariton coupling to whispering-gallery modes (WGMs). We also demonstrate that the rough surface of Au substrates can acquire a more satisfied enhancement of ZnO emission if the surface geometry of Au substrates is appropriate. Furthermore, we achieve high Q factor and super low threshold plasmonic WGM lasing from an individual ZnO hexagonal microrod on the surface of the Au substrate, in which Q factor can reach 5790 and threshold is 0.45 KW/cm(2) which is the lowest value reported to date for ZnO nanostructures lasing, at least 10 times smaller than that of ZnO at the nanometer. Electron transfer mechanisms are proposed to understand the physical origin of quenching and enhancement of ZnO emission on the surface of Au substrates. These investigations show that this novel coupling mode holds a great potential of ZnO hexagonal micro- and nanorods for data storage, bio-sensing, optical communications as well as all-optic integrated circuits.

  8. Far-infrared elastic scattering proposal for the Avogadro Project's silicon spheres

    Science.gov (United States)

    Humayun, Muhammad Hamza; Khan, Imran; Azeem, Farhan; Chaudhry, Muhammad Rehan; Gökay, Ulaş Sabahattin; Murib, Mohammed Sharif; Serpengüzel, Ali

    2018-05-01

    Avogadro constant determines the number of particles in one mole of a substance, thus relating the molar mass of the substance to the mass of this substance. Avogadro constant is related to Système Internationale base units by defining the very concept of chemical quantity. Revisions of the base units created a need to redefine the Avogadro constant, where a collaborative work called the Avogadro Project is established to employ optical interferometry to measure the diameter of high quality 100 mm silicon spheres. We propose far-infrared spectroscopy for determining the Avogadro constant by using elastic scattering from the 100 mm Avogadro Project silicon spheres. Similar spectroscopic methods are already in use in the near-infrared, relating whispering gallery modes of the 1 mm silicon spheres to the diameter of the spheres. We present numerical simulations in the far-infrared and the near-infrared, as well as spatially scaled down elastic scattering measurements in the near-infrared. These numerical and experimental results show that, the diameter measurements of 100 mm single crystal silicon spheres with elastic scattering in the far-infrared can be considered as an alternative to optical interferometry.

  9. Optical micro-bubble resonators as promising biosensors

    Science.gov (United States)

    Giannetti, A.; Barucci, A.; Berneschi, S.; Cosci, A.; Cosi, F.; Farnesi, D.; Nunzi Conti, G.; Pelli, S.; Soria, S.; Tombelli, S.; Trono, C.; Righini, G. C.; Baldini, F.

    2015-05-01

    Recently, optical micro-bubble resonators (OMBRs) have gained an increasing interest in many fields of photonics thanks to their particular properties. These hollow microstructures can be suitable for the realization of label - free optical biosensors by combining the whispering gallery mode (WGM) resonator properties with the intrinsic capability of integrated microfluidics. In fact, the WGMs are morphology-dependent modes: any change on the OMBR inner surface (due to chemical and/or biochemical binding) causes a shift of the resonance position and reduces the Q factor value of the cavity. By measuring this shift, it is possible to obtain information on the concentration of the analyte to be detected. A crucial step for the development of an OMBR-based biosensor is constituted by the functionalization of its inner surface. In this work we report on the development of a physical and chemical process able to guarantee a good homogeneity of the deposed bio-layer and, contemporary, to preserve a high quality factor Q of the cavity. The OMBR capability of working as bioassay was proved by different optical techniques, such as the real time measurement of the resonance broadening after each functionalization step and fluorescence microscopy.

  10. Electrical properties of as-grown and proton-irradiated high purity silicon

    Energy Technology Data Exchange (ETDEWEB)

    Krupka, Jerzy, E-mail: krupka@imio.pw.edu.pl [Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Karcz, Waldemar [Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna (Russian Federation); Kamiński, Paweł [Institute of Electronic Materials Technology, Wólczyńska 13, 301-919 Warsaw (Poland); Jensen, Leif [Topsil Semiconductor Materials A/S, Siliciumvej 1, DK-3600 Frederikssund (Denmark)

    2016-08-01

    The complex permittivity of as-grown and proton-irradiated samples of high purity silicon obtained by the floating zone method was measured as a function of temperature at a few frequencies in microwave spectrum by employing the quasi TE{sub 011} and whispering gallery modes excited in the samples under test. The resistivity of the samples was determined from the measured imaginary part of the permittivity. The resistivity was additionally measured at RF frequencies employing capacitive spectroscopy as well as in a standard direct current experiment. The sample of as-grown material had the resistivity of ∼85 kΩ cm at room temperature. The sample irradiated with 23-MeV protons had the resistivity of ∼500 kΩ cm at 295 K and its behavior was typical of the intrinsic material at room and at elevated temperatures. For the irradiated sample, the extrinsic conductivity region is missing and at temperatures below 250 K hopping conductivity occurs. Thermal cycle hysteresis of the resistivity for the sample of as-grown material is observed. After heating and subsequent cooling of the sample, its resistivity decreases and then slowly (∼50 h) returns to the initial value.

  11. Large power electron tubes for high frequency heating

    International Nuclear Information System (INIS)

    Okamoto, Tadashi; Sato, Hisaaki.

    1988-01-01

    On the large power electron tubes used for electron cyclotron heating, lower hybrid resonance frequency heating, and ion cyclotron range of frequency heating, namely gyrotron, klystron and quadrupole tube, the features, the present status of development, the construction, the principle and so on are explained. The research and development of gyrotrons are most advanced in USSR, the inventor. The course of the development of gyrotrons in foreign countries and in Japan is described. There are many variants of gyrotrons, for example whispering gallery mode, klystron type, backward wave oscillator type, gyro-peniotron and others. The principle of gyrotrons is explained, and about the examples of the developed gyrotrons, the design parameters are shown. For the purpose of using for the LHRF heating in JT-60, a superlarge power klystron of 1 MW output at 2 GHz frequency, which is the largest class in the world, has been developed. Its total length is 2.7 m, and weight is 1.5 t. It features, construction, function and performance are reported. The trend of large power quadrupole tubes is toward stable action with large power in VHF zone, and the typical products in USA and Europe are shown. (Kako, I.)

  12. Millimetre waves and plasma physics

    International Nuclear Information System (INIS)

    Brand, G.F.

    1999-01-01

    Full text: This talk is a review of the plasma-related presentations at the 23rd International Conference on Infrared and Millimeter Waves held at the University of Essex, Colchester, UK 7-11 September 1998. Of most relevance to fusion is the development of high-power sources for electron cyclotron resonance heating and current drive. The requirements for ITER are a total of 50 MW at 170 GHz. The state of the art is illustrated by (a) high-power gyrotrons that deliver 1 MW for 1 s at 170 GHz, and (b) a free-electron maser that has generated millimetre waves for the first time, 730 kW at 200 GHz. A number of papers describe new technologies that allow high powers to be achieved; internal mode converters to convert the whispering-gallery mode generated in the gyrotron cavity into a gaussian beam, depressed collectors to raise the efficiency from 1/3 to better than 1/2, CVD diamond output windows and coaxial gyrotrons with improved mode purity. Other papers describe transmission lines and steerable mirrors. Several papers deal with millimetre-wave plasma diagnostics for fusion such as electron cyclotron emission measurements and reflectometry. (author)

  13. Multi-mode technique for the determination of the biaxial Y{sub 2}SiO{sub 5} permittivity tensor from 300 to 6 K

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, N. C., E-mail: natalia.docarmocarvalho@research.uwa.edu.au; Le Floch, J-M.; Tobar, M. E. [School of Physics, The University of Western Australia, Crawley 6009 (Australia); ARC Centre of Excellence for Engineered Quantum Systems (EQuS), 35 Stirling Hwy, Crawley 6009 (Australia); Krupka, J. [Instytut Mikroelektroniki i Optoelektroniki PW, Koszykowa 75, 00-662 Warsaw (Poland)

    2015-05-11

    The Y{sub 2}SiO{sub 5} (YSO) crystal is a dielectric material with biaxial anisotropy with known values of refractive index at optical frequencies. It is a well-known rare-earth (RE) host material for optical research and more recently has shown promising performance for quantum-engineered devices. In this paper, we report the first microwave characterization of the real permittivity tensor of a bulk YSO sample, as well as an investigation of the temperature dependence of the tensor components from 296 K down to 6 K. Estimated uncertainties were below 0.26%, limited by the precision of machining the cylindrical dielectric. Also, the electrical Q-factors of a few electromagnetic modes were recorded as a way to provide some information about the crystal losses over the temperature range. To solve the tensor components necessary for a biaxial crystal, we developed the multi-mode technique, which uses simultaneous measurement of low order whispering gallery modes. Knowledge of the permittivity tensor offers important data, essential for the design of technologies involving YSO, such as microwave coupling to electron and hyperfine transitions in RE doped samples at low temperatures.

  14. Hollow spheres: crucial building blocks for novel nanostructures and nanophotonics

    Science.gov (United States)

    Zhong, Kuo; Song, Kai; Clays, Koen

    2018-03-01

    In this review, we summarize the latest developments in research specifically derived from the unique properties of hollow microspheres, in particular, hollow silica spheres with uniform shells. We focus on applications in nanosphere (colloidal) lithography and nanophotonics. The lithography from a layer of hollow spheres can result in nanorings, from a multilayer in unique nano-architecture. In nanophotonics, disordered hollow spheres can result in antireflection coatings, while ordered colloidal crystals (CCs) of hollow spheres exhibit unique refractive index enhancement upon infiltration, ideal for optical sensing. Furthermore, whispering gallery mode (WGM) inside the shell of hollow spheres has also been demonstrated to enhance light absorption to improve the performance of solar cells. These applications differ from the classical applications of hollow spheres, based only on their low density and large surface area, such as catalysis and chemical sensing. We provide a brief overview of the synthesis and self-assembly approaches of the hollow spheres. We elaborate on their unique optical features leading to defect mode lasing, optomicrofluidics, and the existence of WGMs inside shell for light management. Finally, we provide a perspective on the direction towards which future research relevant to hollow spheres might be directed.

  15. Uso e Conservação de florestas de galeria do bioma Pampa Brasileiro Anthropogenic use of gallery forests in the Brazilian Pampa - doi: 10.4025/actascibiolsci.v35i2.13458

    Directory of Open Access Journals (Sweden)

    Valdir Marcos Stefenon

    2013-05-01

    Full Text Available Como efeito do crescimentop demográfico, muitas cidades no Sul do Brasil experimentaram, na última década, um processo de degradação de áreas de preservação ambiental. O planejamento de programas de recuperação de florestas depende de conhecimento estruturado sobre a utilização de espécies vegetais pelas comunidades locais. Entrevistas semi-estruturadas e inventários fitossociológicos foram empregados para acessar o efeito do uso antropogênico de espécies arbóreas de matas de galeria em áreas do Pampa brasileiro. Oitenta e quatro informantes foram entrevistados e listaram um total de 43 espécies, pertencentes a 23 famílias botânicas. Quatro categorias de uso foram identificadas para as espécies citadas: lenha, medicamento, alimento e madeira. As três espécies mais importantes foram Blepharocalyx salicifolius, Eugenia uniflora e Salix babilonica. O inventário fitossociológico sugere que a exploração antropogênica da mata de galeria está levando algumas espécies a extinção e/ou ameaça local. Com o objetivo de preservar as matas de galeria, sugere-se a re-avaliação das atitudes das comunidades locais, visando um uso sustentável das matas e o reflorestamento das margens de rios com espécies nativas produtoras de frutos comestíveis, possibilitando a exploração de produtos não-madeireiros, assim como o estabelecimento de animais nestes ambientes.As effect of demographic growth in the last decades, many cities in Southern Brazil experienced a degradation process of conservation areas. In this study, semi-structured interviews and a phytosociological inventory were employed to assess the effect of anthropogenic use of tree species of the gallery forest in the Brazilian Pampa. Eighty-four informants were interviewed and listed a total of 43 tree species, belonging to 23 botanical families. Four categories of use were identified for the referenced species: firewood, medicinal, food and timber. The three most

  16. Tuning Valley Polarization in a WSe_{2} Monolayer with a Tiny Magnetic Field

    Directory of Open Access Journals (Sweden)

    T. Smoleński

    2016-05-01

    Full Text Available In monolayers of semiconducting transition metal dichalcogenides, the light helicity (σ^{+} or σ^{-} is locked to the valley degree of freedom, leading to the possibility of optical initialization of distinct valley populations. However, an extremely rapid valley pseudospin relaxation (at the time scale of picoseconds occurring for optically bright (electric-dipole active excitons imposes some limitations on the development of opto-valleytronics. Here, we show that valley pseudospin relaxation of excitons can be significantly suppressed in a WSe_{2} monolayer, a direct-gap two-dimensional semiconductor with the exciton ground state being optically dark. We demonstrate that the already inefficient relaxation of the exciton pseudospin in such a system can be suppressed even further by the application of a tiny magnetic field of about 100 mT. Time-resolved spectroscopy reveals the pseudospin dynamics to be a two-step relaxation process. An initial decay of the pseudospin occurs at the level of dark excitons on a time scale of 100 ps, which is tunable with a magnetic field. This decay is followed by even longer decay (>1  ns, once the dark excitons form more complex pseudo-particles allowing for their radiative recombination. Our findings of slow valley pseudospin relaxation easily manipulated by the magnetic field open new prospects for engineering the dynamics of the valley pseudospin in transition metal dichalcogenides.

  17. Interfacial characteristics and fracture behavior of spark-plasma-sintered TiNi fiber-reinforced 2024Al matrix composites

    International Nuclear Information System (INIS)

    Dong, Peng; Wang, Zhe; Wang, Wenxian; Chen, Shaoping; Zhou, Jun

    2017-01-01

    Embedding of shape memory alloy (SMA) fibers into materials to fabricate SMA composites has attracted considerable attention because of the potential applicability of these composites in smart systems and structures. In this study, 2024Al matrix composites reinforced by continuous TiNi SMA fibers were fabricated using spark plasma sintering (SPS). The interface between the fibers and matrix consisted of a bilayer. The layer close to the fiber consisted of a multiple phase mixture, and the other layer exhibited a periodic morphology resulting from the alternating phases of Al 3 Ti and Al 3 Ni. In addition, a small quantity of TiO 2 phases was also observed in the interface layer. Based on detailed interface studies of the orientation relationships between the Al 3 Ti, Al 3 Ni, and TiO 2 phases and the atomic correspondence at phase boundaries, the effects of the interface phases on the fracture behavior of the composites were demonstrated.

  18. Lossless synthesis of graphene nanosheets decorated with tiny cadmium sulfide quantum dots with excellent nonlinear optical properties

    International Nuclear Information System (INIS)

    Feng Miao; Zhan Hongbing; Sun Ruiqing; Chen Yu

    2010-01-01

    The implantation and growth of metal nanoparticles on graphene nanosheets (GNS) leads directly to severe damage to the regular structure of the graphene sheets, which disrupts the extended π conjugation, resulting in an impaired device performance. In this paper, we describe a facile approach for achieving the lossless formation of graphene composite decorated with tiny cadmium sulfide quantum dots (QDs) with excellent nonlinear optical properties by using benzyl mercaptan (BM) as the interlinker. The mercapto substituent of BM binds to the CdS QDs during their nucleation and growth process, and then the phenyl comes into contact with the GNS via the π-π stacking interaction. Using this strategy, CdS QDs with an average diameter of 3 nm are uniformly dispersed over the surface of graphene, and the resulting QD-graphene composite exhibits excellent optical limiting properties, mainly contributed by nonlinear scattering and nonlinear absorption, upon both 532 and 1064 nm excitations, in the nanosecond laser pulse regime.

  19. Interfacial characteristics and fracture behavior of spark-plasma-sintered TiNi fiber-reinforced 2024Al matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Peng, E-mail: dongpeng@tyut.edu.cn [College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Shanxi Key Laboratory of Advanced Magnesium-Based Materials, Taiyuan 030024 (China); Wang, Zhe [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Wang, Wenxian [College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Shanxi Key Laboratory of Advanced Magnesium-Based Materials, Taiyuan 030024 (China); Chen, Shaoping [College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Zhou, Jun [Department of Mechanical Engineering, Pennsylvania State University Erie, Erie, PA 16563 (United States)

    2017-04-13

    Embedding of shape memory alloy (SMA) fibers into materials to fabricate SMA composites has attracted considerable attention because of the potential applicability of these composites in smart systems and structures. In this study, 2024Al matrix composites reinforced by continuous TiNi SMA fibers were fabricated using spark plasma sintering (SPS). The interface between the fibers and matrix consisted of a bilayer. The layer close to the fiber consisted of a multiple phase mixture, and the other layer exhibited a periodic morphology resulting from the alternating phases of Al{sub 3}Ti and Al{sub 3}Ni. In addition, a small quantity of TiO{sub 2} phases was also observed in the interface layer. Based on detailed interface studies of the orientation relationships between the Al{sub 3}Ti, Al{sub 3}Ni, and TiO{sub 2} phases and the atomic correspondence at phase boundaries, the effects of the interface phases on the fracture behavior of the composites were demonstrated.

  20. Stress Relaxation Effects in TiNi SMA During Superelastic Deformation: Experiment and Constitutive Model

    Science.gov (United States)

    Pieczyska, Elżbieta A.; Kowalewski, Zbigniew L.; Dunić, Vladimir Lj.

    2017-12-01

    This paper presents an investigation of thermomechanical effects related to the phenomena of stress relaxation occurring in TiNi SMA subjected to modified program of displacement-controlled tension. The deformation data were taken from testing machine, whereas the temperature changes accompanying the exothermic/endothermic martensite forward/reverse transformation were measured by infrared camera. At the advanced stages of the transformations, the strain was kept constant for a few minutes and the SMA load and temperature were recorded continuously. As a consequence, the stress and temperature changed significantly during the loading stops. A large stress drop, caused by the transformation, was observed during the relaxation stage in both courses of the SMA loading and unloading. Moreover, the non-uniform temperature distribution, reflecting macroscopically inhomogeneous transformation, lapsed while the strain was kept constant, yet restarted at the end of the relaxation stop and developed at the reloading stage. Along with the experimental results, the mechanical and thermal responses induced by the transformation were obtained by 3D coupled thermomechanical numerical analysis, realized in partitioned approach. Latent heat production was correlated with an amount of the martensitic volume fraction. The stress and temperature drops recorded during the experiment were satisfactorily reproduced by the model proposed for the SMA thermomechanical coupling.

  1. Rn-Gas Concentration and Working Level Measurements Using SSNTD in Uranium Exploration Galleries Allouga Mine, Sinai, Egypt

    International Nuclear Information System (INIS)

    Abdel-Monem, A.A.; Hassan, S.F.; Abdel-Kader, F.H.; El-Naggar, A.M.; Essia, H.M.; Abdel-Hafez, A.A.

    2008-01-01

    Measurements of Rn-gas concentrations and Working Level (WL), were carried out in the U-exploration galleries at El- Allouga Mine, Sinai, Egypt by passive techniques (SSNTD) during the four seasons ( Summer, Fall, Winter and Spring) using four different detector types: CR-39, MK, CN-85 and LR-115.Twenty eight (28) stations were chosen for this purpose reflecting different environmental conditions as measurement sites within the galleries. The Rn-gas concentrations , in the summer period ranged from 25.86 to 44.2 pCi/l in the ventilated stations and from 488.98 to 611.16 pCi/l in the non-ventilated stations. In the fall period , the average Rn-gas concentrations in the ventilated stations ranged from 31.61 to 56.36 pCi/l while in the non-ventilated stations from 457.61 to 621.52 pCi/l. In the winter period, the average Rn-gas concentrations in the ventilated stations ranged from 27.59 to 66.45 pCi/l while in the non- ventilated stations from 499.09 to 603.81 pCi/l. In the spring the Rn-gas concentrations ranged from 30.8 to 46.77 pCi/l in the ventilated stations, whereas, in the non-ventilated stations from 404.06 to 445.18 pCi/l. The (WL), in the summer period, ranged from 0.143 to 0.247 in the ventilated sector and from 4.408 to 5.497 in the non-ventilated stations .In fall, the( WL) ranged from 0.166 to 0.295 in the ventilated stations and from 4.123 to 5.624 in the non-ventilated stations. In the winter, the (WL) ranged from 0.105 to 0.37 in the ventilated stations and from 4.138 to 5.26 in the non-ventilated stations. In the spring, the (WL) in the ventilated stations ranged from 0.152 to 0.241 and from 3.696 to 4.087 in the non-ventilated stations. These results indicate that: i)The low measured Rn gas and (WL) values in the ventilated stations reflect the effect of variations in meteorological conditions on (WL) determination where the air flow carries the Rn-gas before it decays and the daughters are plated onto the SSNTD . ii) The larger ranges for Rn

  2. Microstructure and functional properties of the TiNi- and CuAl-based SMA thin films and coats produced by PVD technique

    International Nuclear Information System (INIS)

    Kolomytsev, V.; Musienko, R.; Nevdacha, V.; Panarin, V.; Pasko, A.; Cesari, E.; Segui, C.; Humbeeck, J. van

    2000-01-01

    The TiNi- and CuAl-based shape memory alloy thin films and wear/corrosion resistant surface coats have been produced by the ion-plasma deposition method with an arc dispersion of the cathode/target. This technique was widely used for production of the coats from a sprayed pure metal or a single-phase alloy. We have offered to use this process for dispersion of the heterophase alloys like shape memory alloys. The arguments for choosing of this technique are discussed with respect to creation of the conditions for preservation not only chemical composition, but also phase structure of an alloy in a covering, thus the shape memory/superelastic effects to be kept in a coat. (orig.)

  3. Tiny changes in local order identify the cluster formation threshold in model fluids with competing interactions.

    Science.gov (United States)

    Bomont, Jean-Marc; Costa, Dino; Bretonnet, Jean-Louis

    2017-06-14

    We use Monte Carlo simulations to carry out a thorough analysis of structural correlations arising in a relatively dense fluid of rigid spherical particles with prototype competing interactions (short-range attractive and long-range repulsive two-Yukawa model). As the attraction strength increases, we show that the local density of the fluid displays a tiny reversal of trend within specific ranges of interparticle distances, whereupon it decreases first and increases afterwards, passing through a local minimum. Particles involved in this trend display, accordingly, distinct behaviours: for a sufficiently weak attraction, they seem to contribute to the long-wave oscillations typically heralding the formation of patterns in such fluids; for a stronger attraction, after the reversal of the local density has occurred, they form an outer shell of neighbours stabilizing the existing aggregation seeds. Following the increment of attraction, precisely in correspondence of the local density reversal, the local peak developed in the structure factor at small wavevectors markedly rises, signalling-in agreement with recent structural criteria-the onset of a clustered state. A detailed cluster analysis of microscopic configurations fully validates this picture.

  4. EZG08 project: acoustic experiments to monitor the EDZ during the gallery excavation process in the Mont Terri Underground Research Laboratory (Switzerland)

    International Nuclear Information System (INIS)

    Le Gonidec, Y.; Kergosien, B.; Schubnel, A.; Gueguen, Y.; Wassermann, J.; Gibert, D.; Sarout, J.; Nussbaum, C.

    2010-01-01

    Document available in extended abstract form only. In the Underground Research Laboratory (URL) at Mont Terri, a new gallery G08 was planned to be excavated in 2008 following an original process: the excavation process allowed to monitor the Excavation Damaged Zone (EDZ) from geophysical measurements designed and installed at the end of face of the EZ-G04 gallery during the excavation from the other side, i.e. the end face of the EZ-G08 gallery. The objectives of the project concern spatio-temporal changes of the EDZ: among the methodological developments adapted for the EZG08 project to provide complementary information, acoustic experiments have been prepared in horizontal boreholes to perform the continuous acoustic monitoring of the Excavation Damaged Zone (EDZ). The acoustic measurements, performed on acoustic arrays of several receivers, have been recorded during one month, following two main steps: - Active acoustic surveys: a source is introduced in a central borehole (BEZG5) allowing tomography experiments in the far field and in the near field, i.e. close to and far from BEZG5, respectively. - Acoustic emissions: during the excavation process, numerous acoustic emissions can be detected and associated to micro-seismic events due to rapid crack propagation, generated by the rock relaxation, or simply associated to the excavation process. From the tomography measurements, the acoustic wave velocity field can be estimated, with P and S-wave velocities roughly equal to 2500 m/s-3500 m/s, and 1500 m/s, respectively. The acoustic setup does not show variations of P-wave velocity during the campaign, but spatial variations which could be associated to anisotropic elastic properties of the rock with the maximum P-wave velocities close to the bedding plane. An original method based on a multifrequency approach puts in evidence a frequency dependence of the velocity, with a striking phenomena since the wave velocity decreases with increasing frequency. This effect

  5. [Concordance among analysts from Latin-American laboratories for rice grain appearance determination using a gallery of digital images].

    Science.gov (United States)

    Avila, Manuel; Graterol, Eduardo; Alezones, Jesús; Criollo, Beisy; Castillo, Dámaso; Kuri, Victoria; Oviedo, Norman; Moquete, Cesar; Romero, Marbella; Hanley, Zaida; Taylor, Margie

    2012-06-01

    The appearance of rice grain is a key aspect in quality determination. Mainly, this analysis is performed by expert analysts through visual observation; however, due to the subjective nature of the analysis, the results may vary among analysts. In order to evaluate the concordance between analysts from Latin-American rice quality laboratories for rice grain appearance through digital images, an inter-laboratory test was performed with ten analysts and images of 90 grains captured with a high resolution scanner. Rice grains were classified in four categories including translucent, chalky, white belly, and damaged grain. Data was categorized using statistic parameters like mode and its frequency, the relative concordance, and the reproducibility parameter kappa. Additionally, a referential image gallery of typical grain for each category was constructed based on mode frequency. Results showed a Kappa value of 0.49, corresponding to a moderate reproducibility, attributable to subjectivity in the visual analysis of grain images. These results reveal the need for standardize the evaluation criteria among analysts to improve the confidence of the determination of rice grain appearance.

  6. Method of cutting steeply falling coal beds. [Bacteria, which only grow on methane, are injected into the coal bed and form low viscosity polysaccharides: as a result the coal collapses into the haulage gallery and is hauled away

    Energy Technology Data Exchange (ETDEWEB)

    Gretsinger, B Ye; Chernyshenko, D V; Levin, A D; Malashenko, Yu R; Shinkovskiy, V A; Shurova, Z P; Volkov, V I

    1982-01-01

    The purpose of the invention is to reduce outlays for collapse and output of coal by creating artificial cavities of sliding along the coal bed in the surrounding rocks. This goal is achieved because in the well drilled in the bed for the entire height of the level, a suspension of cells of methane-oxidizing microorganisms is injected. The methane-oxidizing microorganisms used are, for example, the thermophilic culture Methylococcus thermophilus of strains ShP which grow at 45-65/sup 0/ C, or the mesophilic culture Methanomonas rubna of strains 15 Sh growing at 20-37/sup 0/ C. As a result of the vital activity of these cultures, polysaccharides are formed with viscosity of 5-7 and 3-4 St respectively. The mine pressure disrupts the blocks between the wells, and the outline section of the steeply dropping coal bed, being destroyed, slides on the products of vital activity of the microorganisms to the haulage gallery. Then the coal drops on cross cuts to the field gallery through which it is transported. Studies established that the only coal substrate which is suitable for growth of these microorganism cultures is methane. The synthesis of one g of absolutely dry substance of these microorganism requires 1.78 g of methane and 4.7 g of oxygen. The cultures are resistant to hydrostatic pressure from 20 to 150 atm and short-term pressure of gradient drops which occur during injection of the cellular suspension into the coal bed. They are filtered through the coal with preservation of the oxidizing and reproductive properties and are cultivated on the methane contained in the bed and form considerable number of exopolysaccarides. The polysaccarides weaken the bond between the bed and the surrounding rocks and serve as a unique lubricant promoting the sliding towards the haulage gallery of the coal blocks destroyed by mine pressure.

  7. ARECIBO MULTI-EPOCH H I ABSORPTION MEASUREMENTS AGAINST PULSARS: TINY-SCALE ATOMIC STRUCTURE

    International Nuclear Information System (INIS)

    Stanimirovic, S.; Weisberg, J. M.; Pei, Z.; Tuttle, K.; Green, J. T.

    2010-01-01

    We present results from multi-epoch neutral hydrogen (H I) absorption observations of six bright pulsars with the Arecibo telescope. Moving through the interstellar medium (ISM) with transverse velocities of 10-150 AU yr -1 , these pulsars have swept across 1-200 AU over the course of our experiment, allowing us to probe the existence and properties of the tiny-scale atomic structure (TSAS) in the cold neutral medium (CNM). While most of the observed pulsars show no significant change in their H I absorption spectra, we have identified at least two clear TSAS-induced opacity variations in the direction of B1929+10. These observations require strong spatial inhomogeneities in either the TSAS clouds' physical properties themselves or else in the clouds' galactic distribution. While TSAS is occasionally detected on spatial scales down to 10 AU, it is too rare to be characterized by a spectrum of turbulent CNM fluctuations on scales of 10 1 -10 3 AU, as previously suggested by some work. In the direction of B1929+10, an apparent correlation between TSAS and interstellar clouds inside the warm Local Bubble (LB) indicates that TSAS may be tracing the fragmentation of the LB wall via hydrodynamic instabilities. While similar fragmentation events occur frequently throughout the ISM, the warm medium surrounding these cold cloudlets induces a natural selection effect wherein small TSAS clouds evaporate quickly and are rare, while large clouds survive longer and become a general property of the ISM.

  8. Rubber bulge forming of single-stage bellows of TiNi shape memory alloy using the displacement control method

    International Nuclear Information System (INIS)

    Senba, Hiromasa; Yamaji, Toru; Okita, Keisuke; Okabe, Nagatoshi; Yamauchi, Kiyoshi; Matsumoto, Kenya

    2005-01-01

    This paper deals with the bulge process for forming the single-stage bellows of TiNi shape memory alloys, which is proposed as a new type of seismic applications, and especially considering the material's special behavior. Thin walled tubes with 20% cold work, whose composition is Ti-51.0 at% Ni, were prepared. First they are appropriately heat-treated and then the rubber bulge process is introduced for the tubes under the condition of austenite phase at room temperature. Displacement control method is adapted to the process. Theoretical prediction of change in outer diameter of the tube on compression is derived, and modified taking into account the progress of the stress-induced martensite transformation on tube's surface by observing the detachment of the oxide layer of the surface. Finally theoretical relationship between compressive displacement and the outer diameter of the tube, which is the most important for the design of the bellows shape, is cleared. (author)

  9. What does learner speech sound like? A case study on adult learners of isiXhosa

    CSIR Research Space (South Africa)

    Badenhorst, Jaco

    2016-12-01

    Full Text Available moved during recording or by a sound/beep that results from the press of a button and an obstruction of the device microphone. • Low volume: Speech is too soft to understand what is being said. • Whispering: Speaker whispers during recording. • Laughter...-processing categories. If any of these categories were marked for a particular utterance, the utterance was discarded. The event categories were combined as follows: • Option 1: Empty, Whispering, Laughter, Background speech, Transcription mismatch • Option 2: Empty...

  10. Geology and geochronology of the sub-Antarctic Snares Islands/Tini Heke, New Zealand

    International Nuclear Information System (INIS)

    Scott, J.M.; Turnbull, I.M.; Sagar, M.W.; Tulloch, A.J.; Waight, T.E.; Palin, J.M.

    2015-01-01

    The first comprehensive geological map, a summary of lithologies and new radiogenic isotope data (U-Pb, Rb-Sr) are presented for crystalline rocks of the Sub-Antarctic Snares Islands/Tini Heke, 150 km south of Stewart Island. The main lithology is Snares Granite (c. 109 Ma from U-Pb dating of zircon), which intrudes Broughton Granodiorite (c. 114 Ma from U-Pb zircon) on Broughton Island. Rafts of schist within Snares Granite are common on the outlying Western Chain islets, and rare on North East and Broughton islands. Zircon grains extracted from one schistose raft on Broughton Island are prismatic and yield an essentially unimodal age population of c. 116 Ma that is within error of the granodiorite. These properties suggest that the dated raft represents a meta-igneous rock despite its mica-rich nature. Some schistose rocks on the Western Chain contain coarse relict plagioclase phenocrysts and appear to have an igneous protolith. No conclusive metasedimentary rocks have been identified, although sillimanite-bearing mica-rich schist occurs on Rua. Deformation of the crystalline rocks occurred after Snares Granite intrusion and before cooling below muscovite K-Ar closure at 400 ± 50 degrees C at 95 Ma. This period overlaps the age of extensional ductile shear zones on Stewart Island. The discovery of several basaltic dykes, which cut across fabrics and are unmetamorphosed, indicates that volcanic rocks are associated with all Sub-Antarctic island groups. The larger of the islands are overlain by peat, which on North East Island also contains gravel deposits. (author).

  11. Economic, energy and GHG emissions performance evaluation of a WhisperGen Mk IV Stirling engine μ-CHP unit in a domestic dwelling

    International Nuclear Information System (INIS)

    Conroy, G.; Duffy, A.; Ayompe, L.M.

    2014-01-01

    Highlights: • The performance of a Stirling engine MK IV micro-CHP unit was evaluated in a domestic dwelling in Ireland. • The performance of the micro-CHP was compare to that of a condensing gas boiler. • The micro-CHP unit resulted in an annual cost saving of €180 compared to the condensing gas boiler. • Electricity imported from the grid decreased by 20.8% while CO 2 emissions decreased by 16.1%. • The micro-CHP unit used 2889 kW h of gas more than the condensing gas boiler during one year of operation. - Abstract: This paper presents an assessment of the energy, economic and greenhouse gas emissions performances of a WhisperGen Mk IV Stirling engine μ-CHP unit for use in a conventional house in the Republic of Ireland. The energy performance data used in this study was obtained from a field trial carried out in Belfast, Northern Ireland during the period June 2004–July 2005 by Northern Ireland Electricity and Phoenix Gas working in collaboration with Whispertech UK. A comparative performance analysis between the μ-CHP unit and a condensing gas boiler revealed that the μ-CHP unit resulted in an annual cost saving of €180 with an incremental simple payback period of 13.8 years when compared to a condensing gas boiler. Electricity imported from the grid decreased by 20.8% while CO 2 emissions decreased by 16.1%. The μ-CHP unit used 2889 kW h of gas more than the condensing gas boiler

  12. Gallery forest restoration by the attainment of carbon credit: a social-environmental proposal for low-income community

    International Nuclear Information System (INIS)

    Coelho, Maria Carolina Crisci

    2007-01-01

    Due to intensification in climate changes by anthropogenic causes, to the recognition of the environmental importance of the Gallery Forest and its intense degradation, this work presents an analysis of the possibilities of carbon credit attainment by low-income community, as part of an incentive program for the restoration of these areas. Two ways are demonstrated: projects of Clean Development Mechanism (CDM), in the scope of the Kyoto Protocol, that generate credits called certified emission reductions; and projects based on voluntary scheme, that generate voluntary emission reductions. Both are difficult to organize and implement. For example: the eligibility of an area, baseline study, monitoring, non-permanence risks of storage carbon, technical and operational structures, operational and business costs, regulated market in consolidation and guarantee of credit acquisition. Nevertheless, this second market presents greater flexibility and acceptance for the forest projects. The social-environmental benefits of these projects are significant and the valuation of their environmental services can revert in financial incentives for low-income community, since that adequately remunerated. The carbon credit can help in the implementation of these projects, contributing for local restoration of the areas and also for carbon capture by the atmosphere, which this is a global subject. (author)

  13. Micro-CTvlab: A web based virtual gallery of biological specimens using X-ray microtomography (micro-CT).

    Science.gov (United States)

    Keklikoglou, Kleoniki; Faulwetter, Sarah; Chatzinikolaou, Eva; Michalakis, Nikitas; Filiopoulou, Irene; Minadakis, Nikos; Panteri, Emmanouela; Perantinos, George; Gougousis, Alexandros; Arvanitidis, Christos

    2016-01-01

    During recent years, X-ray microtomography (micro-CT) has seen an increasing use in biological research areas, such as functional morphology, taxonomy, evolutionary biology and developmental research. Micro-CT is a technology which uses X-rays to create sub-micron resolution images of external and internal features of specimens. These images can then be rendered in a three-dimensional space and used for qualitative and quantitative 3D analyses. However, the online exploration and dissemination of micro-CT datasets are rarely made available to the public due to their large size and a lack of dedicated online platforms for the interactive manipulation of 3D data. Here, the development of a virtual micro-CT laboratory (Micro-CT vlab ) is described, which can be used by everyone who is interested in digitisation methods and biological collections and aims at making the micro-CT data exploration of natural history specimens freely available over the internet. The Micro-CT vlab offers to the user virtual image galleries of various taxa which can be displayed and downloaded through a web application. With a few clicks, accurate, detailed and three-dimensional models of species can be studied and virtually dissected without destroying the actual specimen. The data and functions of the Micro-CT vlab can be accessed either on a normal computer or through a dedicated version for mobile devices.

  14. Information as the Fifth Dimension of the Universe which Fundamental Particles (strings), Dark Matter/Energy and Space-time are Floating in it While they are Listening to its Whispering for Getting Order

    Science.gov (United States)

    Gholibeigian, Hassan; Gholibeigian, Ghasem; Amirshahkarami, Azim; Gholibeigian, Kazem

    2017-01-01

    Four animated sub-particles (sub-strings) as origin of the life and generator of momentum (vibration) of elementary particles (strings) are communicated for transferring information for processing and preparing fundamental particles for the next step. It means that information may be a ``dimension'' of the nature which fundamental particles, dark matter/energy and space-time are floating in it and listening to its whispering and getting quantum information packages about their conditions and laws. So, communication of information which began before the spark to B.B. (Convection Bang), may be a ``Fundamental symmetry'' in the nature because leads other symmetries and supersymmetry as well as other phenomena. The processed information are always carried by fundamental particles as the preserved history and entropy of Universe. So, information wouldn't be destroyed, lost or released by black hole. But the involved fundamental particles of thermal radiation, electromagnetic and gravitational fields carry processed information during emitting from black hole, while they are communicated from fifth dimension for their new movement. AmirKabir University of Technology, Tehran, Iran.

  15. Precise seismic-wave velocity atop Earth's core: No evidence for outer-core stratification

    Science.gov (United States)

    Alexandrakis, Catherine; Eaton, David W.

    2010-05-01

    Earth's outer core is composed of liquid Fe and Ni alloyed with a ˜10% fraction of light elements such as O, S, or Si. Secular cooling and compositional buoyancy drive vigorous convection that sustains the geodynamo, but critical details of light-element composition and thermal regime remain uncertain. Seismic velocities can provide important observational constraints on these parameters, but global reference models such as Preliminary Reference Earth Model ( PREM), IASP91 and AK135 exhibit significant discrepancies in the outermost ˜200 km of the core. Here, we apply an Empirical Transfer Function method to obtain precise arrival times for SmKS waves, a whispering-gallery mode that propagates near the underside of the core-mantle boundary. Models that fit our data are all characterized by seismic velocities and depth gradients in the outermost 200 km of the core that correspond best with PREM. This similarity to PREM, which has a smooth velocity profile that satisfies the adiabatic Adams and Williamson equation, argues against the presence of an anomalous layer of light material near the top of the core as suggested in some previous studies. A new model, AE09, is proposed as a slight modification to PREM for use as a reference model of the outermost core.

  16. On-chip remote charger model using plasmonic island circuit

    Directory of Open Access Journals (Sweden)

    J. Ali

    2018-06-01

    Full Text Available We propose the remote charger model using the light fidelity (LiFi transmission and integrate microring resonator circuit. It consists of the stacked layers of silicon-graphene-gold materials known as a plasmonic island placed at the center of the modified add-drop filter. The input light power from the remote LiFi can enter into the island via a silicon waveguide. The optimized input power is obtained by the coupled micro-lens on the silicon surface. The induced electron mobility generated in the gold layer by the interfacing layer between silicon-graphene. This is the reversed interaction of the whispering gallery mode light power of the microring system, in which the generated power is fed back into the microring circuit. The electron mobility is the required output and obtained at the device ports and characterized for the remote current source applications. The obtained calculation results have shown that the output current of ∼2.5 × 10−11 AW−1, with the gold height of 1.0 µm and the input power of 5.0 W is obtained at the output port, which is shown the potential application for a short range free pace remote charger.

  17. Nanoparticle-coated micro-optofluidic ring resonator as a detector for microscale gas chromatographic vapor analysis.

    Science.gov (United States)

    Scholten, K; Collin, W R; Fan, X; Zellers, E T

    2015-05-28

    A vapor sensor comprising a nanoparticle-coated microfabricated optofluidic ring resonator (μOFRR) is introduced. A multilayer film of polyether functionalized, thiolate-monolayer-protected gold nanoparticles (MPN) was solvent cast on the inner wall of the hollow cylindrical SiOxμOFRR resonator structure, and whispering gallery mode (WGM) resonances were generated with a 1550 nm tunable laser via an optical fiber taper. Reversible shifts in the WGM resonant wavelength upon vapor exposure were detected with a photodetector. The μOFRR chip was connected to a pair of upstream etched-Si chips containing PDMS-coated separation μcolumns and calibration curves were generated from the peak-area responses to five volatile organic compounds (VOCs). Calibration curves were linear, and the sensitivities reflected the influence of analyte volatility and analyte-MPN functional group affinity. Sorption-induced changes in film thickness apparently dominate over changes in the refractive index of the film as the determinant of responses for all VOCs. Peaks from the MPN-coated μOFRR were just 20-50% wider than those from a flame ionization detector for similar μcolumn separation conditions, reflecting the rapid response of the sensor for VOCs. The five VOCs were baseline separated in <1.67 min, with detection limits as low as 38 ng.

  18. Single Nanoparticle Detection Using Optical Microcavities.

    Science.gov (United States)

    Zhi, Yanyan; Yu, Xiao-Chong; Gong, Qihuang; Yang, Lan; Xiao, Yun-Feng

    2017-03-01

    Detection of nanoscale objects is highly desirable in various fields such as early-stage disease diagnosis, environmental monitoring and homeland security. Optical microcavity sensors are renowned for ultrahigh sensitivities due to strongly enhanced light-matter interaction. This review focuses on single nanoparticle detection using optical whispering gallery microcavities and photonic crystal microcavities, both of which have been developing rapidly over the past few years. The reactive and dissipative sensing methods, characterized by light-analyte interactions, are explained explicitly. The sensitivity and the detection limit are essentially determined by the cavity properties, and are limited by the various noise sources in the measurements. On the one hand, recent advances include significant sensitivity enhancement using techniques to construct novel microcavity structures with reduced mode volumes, to localize the mode field, or to introduce optical gain. On the other hand, researchers attempt to lower the detection limit by improving the spectral resolution, which can be implemented by suppressing the experimental noises. We also review the methods of achieving a better temporal resolution by employing mode locking techniques or cavity ring up spectroscopy. In conclusion, outlooks on the possible ways to implement microcavity-based sensing devices and potential applications are provided. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Tracking micro-optical resonances for identifying and sensing novel procaspase-3 protein marker released from cell cultures in response to toxins

    International Nuclear Information System (INIS)

    Chen, Ying-Jen; Vollmer, Frank; Xiang, Wei; Klucken, Jochen

    2016-01-01

    The response of cells to toxins is commonly investigated by detecting intracellular markers for cell death, such as caspase proteins. This requires the introduction of labels by the permeabilization or complete lysis of cells. Here we introduce a non-invasive tool for monitoring a caspase protein in the extracellular medium. The tool is based on highly sensitive optical micro-devices, referred to as whispering-gallery mode biosensors (WGMBs). WGMBs are functionalized with antibodies for the specific and label-free detection of procaspase-3 released from human embryonic kidney HEK293 and neuroglioma H4 cells after introducing staurosporine and rotenone toxins, respectively. Additional tests show that the extracellular accumulation of procaspase-3 is concomitant with a decrease in cell viability. The hitherto unknown release of procaspase-3 from cells in response to toxins and its accumulation in the medium is further investigated by Western blot, showing that the extracellular detection of procaspase-3 is interrelated with cytotoxicity of alpha-synuclein protein (aSyn) overexpressed in H4 cells. These studies provide evidence for procaspase-3 as a novel extracellular biomarker for cell death, with applications in cytotoxicity tests. Such WGMBs could be applied to further identify as-yet unknown extracellular biomarkers using established antibodies against intracellular antigens. (paper)

  20. Design of organic 3D microresonators with microfluidics coupled to thin-film processes for photonic applications

    Science.gov (United States)

    Huby, N.; Pluchon, D.; Coulon, N.; Belloul, M.; Moreac, A.; Gaviot, E.; Panizza, P.; Bêche, B.

    2010-06-01

    We report on the design and realization of photonic integrated devices based on 3D organic microresonators (MR) shaped by an applied fluid mechanism technique. Such an interdisciplinary approach has been judiciously achieved by combining microfluidics techniques and thin-film processes, respectively, for the realizations of microfluidic and optical chips. The microfluidic framework with flow rates control allows the fabrication of microresonators with diameters ranging from 30 to 160 μm. The resonance of an isolated sphere in air has been demonstrated by way of a modified Raman spectroscopy devoted to the excitation of Whispering Gallery Modes (WGM). Then the 3D-MR have been integrated onto an organic chip and positioned either close to the extremity of a taper or alongside a rib waveguide. Both devices have proved efficient evanescent coupling mechanisms leading to the excitation of the WGM confined at the surface of the organic 3D-MR. Finally, a band-stop filter has been used to detect the resonance spectra of organic resonators once being integrated. Such spectral resonances have been observed with an integrated configuration and characterized with a Δ λ = 1.4 nm free spectral range (FSR), appearing as stemming from a 78 μm-radius MR structure.

  1. Direct measurement of wall shear stress in a reattaching flow with a photonic sensor

    International Nuclear Information System (INIS)

    Ayaz, U K; Ioppolo, T; Ötügen, M V

    2013-01-01

    Wall shear stress measurements are carried out in a planar backward-facing step flow using a micro-optical sensor. The sensor is essentially a floating element system and measures the shear stress directly. The transduction method to measure the floating element deflection is based on the whispering gallery optical mode (WGM) shifts of a dielectric microsphere. This method is capable of measuring floating element displacements of the order of a nanometer. The floating element surface is circular with a diameter of ∼960 µm, which is part of a beam that is in contact with the dielectric microsphere. The sensor is calibrated for shear stress as well as pressure sensitivity yielding 7.3 pm Pa −1 and 0.0236 pm Pa −1 for shear stress and pressure sensitivity, respectively. Hence, the contribution by the wall pressure is less than two orders of magnitude smaller than that of shear stress. Measurements are made for a Reynolds number range of 2000–5000 extending to 18 step heights from the step face. The results are in good agreement with those of earlier reports. An analysis is also carried out to evaluate the performance of the WGM sensor including measurement sensitivity and bandwidth. (paper)

  2. 1 million-Q optomechanical microdisk resonators for sensing with very large scale integration

    Science.gov (United States)

    Hermouet, M.; Sansa, M.; Banniard, L.; Fafin, A.; Gely, M.; Allain, P. E.; Santos, E. Gil; Favero, I.; Alava, T.; Jourdan, G.; Hentz, S.

    2018-02-01

    Cavity optomechanics have become a promising route towards the development of ultrasensitive sensors for a wide range of applications including mass, chemical and biological sensing. In this study, we demonstrate the potential of Very Large Scale Integration (VLSI) with state-of-the-art low-loss performance silicon optomechanical microdisks for sensing applications. We report microdisks exhibiting optical Whispering Gallery Modes (WGM) with 1 million quality factors, yielding high displacement sensitivity and strong coupling between optical WGMs and in-plane mechanical Radial Breathing Modes (RBM). Such high-Q microdisks with mechanical resonance frequencies in the 102 MHz range were fabricated on 200 mm wafers with Variable Shape Electron Beam lithography. Benefiting from ultrasensitive readout, their Brownian motion could be resolved with good Signal-to-Noise ratio at ambient pressure, as well as in liquid, despite high frequency operation and large fluidic damping: the mechanical quality factor reduced from few 103 in air to 10's in liquid, and the mechanical resonance frequency shifted down by a few percent. Proceeding one step further, we performed an all-optical operation of the resonators in air using a pump-probe scheme. Our results show our VLSI process is a viable approach for the next generation of sensors operating in vacuum, gas or liquid phase.

  3. The accidental (acoustical) tourist

    Science.gov (United States)

    Van Kirk, Wayne

    2002-11-01

    The acoustical phenomenon observed at an ancient temple in the Great Ball Court at Chichen Itza was described as ''little short of amazing--an ancient whispering gallery'' by Silvanus G. Morley, leader of the Carnegie Institute's archaeological team that excavated and restored these structures in the 1920s. Since then, many others have experienced the extraordinary acoustics at Chichen Itza and other Maya sites. Despite these reports, archaeologists and acousticians have until recently shown little interest in understanding these phenomena. After experiencing Chichen Itza's remarkable acoustics as a tourist in 1994, the author commenced collecting and disseminating information about acoustical phenomena there and at other Mayan sites, hoping to stimulate interest among archaeologists and acousticians. Were these designs accidental or intentional? If intentional, how was the knowledge obtained? How were acoustical features used? This paper highlights the author's collection of anecdotal reports of mysterious Mayan acoustics (http://http://www.ianlawton.com/pa1.htm), recommended reading for scientists and engineers who wish to pursue this fascinating study. Also recounted are some of the reactions of archaeologists-ranging from curious, helpful, and insightful to humorous and appalling--to outsiders' efforts to bring serious scientific attention to the new field of acoustical archaeology.

  4. Acoustical features of two Mayan monuments at Chichen Itza: Accident or design?

    Science.gov (United States)

    Lubman, David

    2002-11-01

    Chichen Itza dominated the early postclassic Maya world, ca. 900-1200 C.E. Two of its colossal monuments, the Great Ball Court and the temple of Kukulkan, reflect the sophisticated, hybrid culture of a Mexicanized Maya civilization. The architecture seems intended for ceremony and ritual drama. Deducing ritual practices will advance the understanding of a lost civilization, but what took place there is largely unknown. Perhaps acoustical science can add value. Unexpected and unusual acoustical features can be interpreted as intriguing clues or irrelevant accidents. Acoustical advocates believe that, when combined with an understanding of the Maya worldview, acoustical features can provide unique insights into how the Maya designed and used theater spaces. At Chichen Itza's monuments, sound reinforcement features improve rulers and priests ability to address large crowds, and Ball Court whispering galleries permit speech communication over unexpectedly large distances. Handclaps at Kukulkan stimulate chirps that mimic a revered bird (''Kukul''), thus reinforcing cultic beliefs. A ball striking playing field wall stimulates flutter echoes at the Great Ball Court; their strength and duration arguably had dramatic, mythic, and practical significance. Interpretations of the possible mythic, magic, and political significance of sound phenomena at these Maya monuments strongly suggests intentional design.

  5. Nanoparticle-coated micro-optofluidic ring resonator as a detector for microscale gas chromatographic vapor analysis

    Science.gov (United States)

    Scholten, K.; Collin, W. R.; Fan, X.; Zellers, E. T.

    2015-05-01

    A vapor sensor comprising a nanoparticle-coated microfabricated optofluidic ring resonator (μOFRR) is introduced. A multilayer film of polyether functionalized, thiolate-monolayer-protected gold nanoparticles (MPN) was solvent cast on the inner wall of the hollow cylindrical SiOx μOFRR resonator structure, and whispering gallery mode (WGM) resonances were generated with a 1550 nm tunable laser via an optical fiber taper. Reversible shifts in the WGM resonant wavelength upon vapor exposure were detected with a photodetector. The μOFRR chip was connected to a pair of upstream etched-Si chips containing PDMS-coated separation μcolumns and calibration curves were generated from the peak-area responses to five volatile organic compounds (VOCs). Calibration curves were linear, and the sensitivities reflected the influence of analyte volatility and analyte-MPN functional group affinity. Sorption-induced changes in film thickness apparently dominate over changes in the refractive index of the film as the determinant of responses for all VOCs. Peaks from the MPN-coated μOFRR were just 20-50% wider than those from a flame ionization detector for similar μcolumn separation conditions, reflecting the rapid response of the sensor for VOCs. The five VOCs were baseline separated in <1.67 min, with detection limits as low as 38 ng.

  6. Costs Of Using “Tiny Targets” to Control Glossina fuscipes fuscipes, a Vector of Gambiense Sleeping Sickness in Arua District of Uganda

    Science.gov (United States)

    Shaw, Alexandra P. M.; Tirados, Inaki; Mangwiro, Clement T. N.; Esterhuizen, Johan; Lehane, Michael J.; Torr, Stephen J.; Kovacic, Vanja

    2015-01-01

    Introduction To evaluate the relative effectiveness of tsetse control methods, their costs need to be analysed alongside their impact on tsetse populations. Very little has been published on the costs of methods specifically targeting human African trypanosomiasis Methodology/Principal Findings In northern Uganda, a 250 km2 field trial was undertaken using small (0.5 X 0.25 m) insecticide-treated targets (“tiny targets”). Detailed cost recording accompanied every phase of the work. Costs were calculated for this operation as if managed by the Ugandan vector control services: removing purely research components of the work and applying local salaries. This calculation assumed that all resources are fully used, with no spare capacity. The full cost of the operation was assessed at USD 85.4 per km2, of which USD 55.7 or 65.2% were field costs, made up of three component activities (target deployment: 34.5%, trap monitoring: 10.6% and target maintenance: 20.1%). The remaining USD 29.7 or 34.8% of the costs were for preliminary studies and administration (tsetse surveys: 6.0%, sensitisation of local populations: 18.6% and office support: 10.2%). Targets accounted for only 12.9% of the total cost, other important cost components were labour (24.1%) and transport (34.6%). Discussion Comparison with the updated cost of historical HAT vector control projects and recent estimates indicates that this work represents a major reduction in cost levels. This is attributed not just to the low unit cost of tiny targets but also to the organisation of delivery, using local labour with bicycles or motorcycles. Sensitivity analyses were undertaken, investigating key prices and assumptions. It is believed that these costs are generalizable to other HAT foci, although in more remote areas, with denser vegetation and fewer people, costs would increase, as would be the case for other tsetse control techniques. PMID:25811956

  7. Effect of desaturation and re-saturation on shale in underground galleries

    International Nuclear Information System (INIS)

    Pham, Q.T.

    2006-03-01

    and re-saturation at the scale of underground facilities are performed with numerical models calibrated with experimental results. Analytical and numerical solutions are found using the finite-elements method to foresee the influence of desaturation and re-saturation on the argillite massif inside the underground galleries. (J.S.)

  8. The effects of inserting a tiny sphere in the center of a nanospherical pore on the structure, adsorption, and capillary condensation of a confined fluid (a DFT study).

    Science.gov (United States)

    Keshavarzi, Ezat; Helmi, Abbas

    2015-02-26

    The modified fundamental measure theory (MFMT) has been employed to investigate the effects of inserting a tiny sphere in the center of a nanospherical pore on the structure, adsorption, and capillary condensation of fluids confined in it. In the first part of this Article, we have solved the weighted density integrals for all pores with spherical symmetries, including spherical and bispherical pores. In the second part, we show that the structure, amount of adsorption, and position of the fluid's capillary condensation change drastically when even a very thin sphere, R(s) = 0.01σ, is inserted into the center of a spherical pore (SP). In fact, the existence of a forbidden region around the inner sphere for the case of bispherical pores, even when R(s) = 0.01σ, causes a remarkable shift in both the amount of adsorption and the bulk density at which the capillary condensation occurs. Moreover, the insertion causes a sudden increase in the value of the contact density of the liquid, or the liquid in equilibrium with its vapor, at the wall of the outer sphere compared to that for an SP. In other words, the insertion of a tiny sphere in an SP causes the liquid droplet, which is formed in the center of the SP, to sprinkle throughout the whole nanopore. Also, we have demonstrated that the critical temperature and densities decrease with decreasing radius of the inner sphere.

  9. Effects of post-irradiation annealing on the transformation behavior of Ti-Ni alloys

    International Nuclear Information System (INIS)

    Kimura, A.; Tsuruga, H.; Morimura, T.; Misawa, T.; Miyazaki, S.

    1993-01-01

    Recovery processes of martensitic transformation of neutron irradiated Ti-50.0, 50.5 and 51.0 at.%Ni alloys during post-irradiation annealing were investigated by means of differential scanning calorimetry (DSC), tensile tests and transmission electron microscope (TEM) observations. Neutron irradiation up to a fluence of 1.2x10 24 n/cm 2 at 333 K suppressed the martensitic transformation as well as the stress-induced martensitic transformation of these alloys above 150 K. The TEM observations revealed that the disordered zones containing small defect clusters in high density were formed in the neutron irradiated Ti-Ni alloys. The DSC measurements also showed that the post-irradiation annealing caused recovery of the transformation of which the progress depended on the annealing temperature and period. A significant retardation of the recovery was recognized in the Ti-51.0 at.%Ni alloy in comparison with the Ti-50.0 at.%Ni alloy. From the shifts in the transformation temperature upon isothermal annealing at various annealing temperatures, the activation energies of the recovery process of the transformation in the neutron irradiated Ti-50.0 and 51.0 at.%Ni alloys were evaluated by a cross-cut method to be 1.2 eV and 1.5 eV, respectively. The recovery of the transformation was ascribed to the re-ordering resulting from decomposition of vacancy clusters, and those obtained values of the activation energy were considered to be the sum of the migration energy of vacancy and the binding energy of vacancy-vacancy cluster. The retardation of the recovery in the Ti-51.0 at%Ni alloy was interpreted in terms of large binding energy in this alloy due to the off-stoichiometry. (author)

  10. Associated fauna and effects of epibiotic barnacles on the relative growth and reproductive indices of Stramonita haemastoma (Gastropoda: Muricidae

    Directory of Open Access Journals (Sweden)

    Tahani El Ayari

    2015-06-01

    Full Text Available To better understand the impacts of biofouling on the biological processes of the basibiont, the effects of epibiotic barnacles on the relative growth and reproductive indices of Stramonita haemastoma (Linnaeus, 1767 were assessed. A total of 1035 specimens were collected monthly for one year from Bizerta Channel (northern Tunisia. Endobiotic species comprised the lithophagous bivalves Lithophaga aristata and Rocellaria dubia of different sizes, communicating with the outside through tiny perforations. Intra-shell tunnels and galleries also sheltered annelids and sipunculids. Epibiotic species comprised algae and highly diversified invertebrates represented by crustaceans, polychaetes, molluscs, echinoderms, ascidians, sponges, bryozoans and sipunculids, with barnacles being the most common group. Comparison of growth features between non-fouled and fouled S. haemastoma revealed higher growth in non-fouled specimens. Differences in reproductive condition indices were detected in few months, being mostly higher in non-fouled snails, but showed no asynchrony in the spawning period for either fouled or non-fouled gastropods hosts.

  11. Nomes Sanumá entre gritos e sussuros Sanumá names between cries and whispers

    Directory of Open Access Journals (Sweden)

    Alcida Rita Ramos

    2008-05-01

    political life. With the arrival of outsiders, foreign names made their entrance in the Sanumá social lexicon, thus relieving the pressure over name secrecy. First came protestant missionaries with the Davids and Sarahs, then gold miners and other jungle adventurers with their regional and idisioncratic nicknames - Ceará, Paraíba, Passarão, etc. - greatly contributing to keep Sanumá personal names away from the public ear. It would thus seem that whispering would no longer be necessary, and crying out people’s names could be done at ease. Things, however, are not as they seem. To what extent Sanumá naming etiquette has reacted to these changes is what I intend to scrutinize.

  12. Low alkaline cement used in the construction of a gallery in the Horonobe Underground Research Laboratory

    International Nuclear Information System (INIS)

    Nakayama, Masashi; Sato, Haruo; Sugita, Yutaka; Ito, Seiji; Minamide, Masashi; Kitagawa, Yoshito

    2011-01-01

    In Japan, any high level radioactive waste (HLW) pos is to be constructed at over 300 m depth below surface. Tunnel support is used for safety during the construction and operation, and shotcrete and concrete lining are used as the tunnel support. Concrete is a composite material comprised of aggregate, cement and various admixtures. Low alkaline cement has been developed for the long term stability of the barrier systems whose performance could be negatively affected by highly alkaline conditions arising due to cement used in a repository. Japan Atomic Energy Agency (JAEA) has developed a low alkaline cement, named as HFSC (Highly Flyash Contained Silicafume Cement), containing over 60wt% of silica-fume (SF) and fly-ash (FA). HFSC was used experimentally as the shotcrete material in construction of part of the 140m deep gallery in the Horonobe Underground Research Laboratory (URL). The objective of this experiment was to assess the performance of HFSC shotcrete in terms of mechanics, workability, durability, and so on. HFSC used in this experiment is composed of 40wt% OPC (Ordinary Portland Cement), 20wt% SF, and 40 wt% FA. This composition was determined based on mechanical testing of various mixes of the above components. Because of the low OPC content, the strength of HFSC tends to be lower than that of OPC. The total length of tunnel using HFSC shotcrete is about 73 m and about 500 m 3 of HESC was used. The workability of HESC shotcrete was confirmed in this experimental construction. (author)

  13. Geophysical monitoring of the EDZ during a gallery excavation in the Opalinus clay of the Mont Terri URL: design and principles of specific in situ experimental setups

    International Nuclear Information System (INIS)

    Gibert, D.; Maineult, A.; Kergosien, B.; Le Gonidec, Y.; Nicollin, F.; Sarout, J.; Wassermann, J.

    2012-01-01

    Document available in extended abstract form only. At the Mont Terri Underground Rock Laboratory, the gallery Ga08 was excavated in August 2008 to join the end-face of the pre-existing gallery Ga04. The Excavation Damaged Zone (EDZ) induced during the gallery construction was monitored from the instrumented face of Ga04. The EZ-G08 experiments required original acquisition setups, specifically designed to be installed in small boreholes and to ensure long term measurements. Different geophysical methods have been experimented for the EZ-G08 project and specific design of the experiments were required in order to coordinate multiple and simultaneous acquisitions, including acoustic emission (AE) acquisition setup (16 acoustic receivers), manufacturing of a combined electrical (256 electrodes) and acoustic tomography setup (64 receivers) to be introduced in horizontal boreholes with small diameters (56 mm), design of an acoustic source, design and manufacturing of a combined electrical tomography (64 lead electrodes) and self-potential measurements (64 un-polarizable electrodes). Other arrays of electrodes have also been placed at the end-face of Ga04 (715 inox electrodes and an array of 16 un-polarizable electrodes). The self-potential (SP) monitoring took place in the borehole BEZ-G5 equipped in mid- February 2008 with a specific device on which custom-made electrodes were fixed. To avoid polarisation effect and guaranty a satisfactorily signal-to-noise ratio, SP was measured with 64 un-polarizable electrodes, with an offset of 15 cm made of a metallic wire in chemical equilibrium with a surrounding solution containing a salt of the same metal. The electrical contact between the solution and the natural medium is ensured by a porous material. The electrodes were mounted upward on a half-cylinder fixed onto an inflatable pipe and introduced in BEZ-G5. The internal pipe was inflated to ensure a good electrical contact between the electrodes and the borehole wall. The

  14. Whispering wind

    DEFF Research Database (Denmark)

    Barlieb, Christophe; Richter, Christoph; Greschner, Björn

    2009-01-01

    Low frequency noise generated by aircraft during pre-takeoff, takeoff, landing and post-landing operations equates to high levels of undesirable ground noise pollution. This phenomenon is gaining heightened popular interest among air transportation specialists and agencies as urban settlements an...

  15. TiNi shape memory alloys: effects of the fabrication route, the oxygen content and the zirconium or hafnium additions on the metallurgical characteristics and the thermomechanical properties

    International Nuclear Information System (INIS)

    Olier, P.

    1996-01-01

    In order to promote the development of Ti-Ni shape memory alloys, we have studied the correlation between the fabrication route, the chemical composition (O 2 content, Zr or Hf additions), the metallurgical characteristics and the thermomechanical properties. A conventional sintering does not allow to obtain a homogeneous compound of pure Ti 50 Ni 50 alloy because of the occurrence of Kirkendall porosities which act as a diffusion barrier. An original process including combustion synthesis and hot-extrusion was successfully developed. Resulting products exhibit a smaller grain size (15-20μm) and an enhanced workability in comparison with products obtained by arc-melting and subsequent hot rolling. The presence of oxygen in equiatomic Ti-Ni alloy induces the oxide precipitation of Ti 4 Ni 2 O x type (with x ≤ 1). The precipitated particle fraction is proportional to the oxygen nominal content of the alloy. We show that the decrease of the transformation temperatures is correlated with the decrease of Ti in solid solution due to Ti 4 Ni 2 O precipitation. Moreover, we find that a fine and homogenous oxide dispersion is suitable to decrease the grain size during hot rolling and to enhance to the one way shape memory properties. An increase of the typical transformation temperatures is obtained through of Zr or Hf (in substitution to Ti). But, an increase of the hardness is measured, and consequently the workability of the ternary alloys becomes reduced. However, it is worthwhile to point out that a Ti 38 Ni 50 Hf 12 product obtained by arc melting and hot extrusion is able to fully recover an apparent plastic strain of more than 4% during tensile tests performed under special loading conditions. Such as behaviour is of great interest with respect to potential applications in a temperature range higher that 100 deg. C. (author)

  16. Magnetic field integral equation analysis of interaction between a surface plasmon polariton and a circular dielectric cavity embedded in the metal.

    Science.gov (United States)

    Chremmos, Ioannis

    2009-12-01

    A rigorous integral equation (IE) analysis of the interaction between a surface plasmon polariton (SPP) and a circular dielectric cavity embedded in a metal half-space is presented. The device is addressed as the plasmonic counterpart of the established integrated optics filter comprising a whispering gallery (WG) resonator coupled to a waveguide. The mathematical formulation is that of a transverse magnetic scattering problem. Using a magnetic-type Green's function of the two-layer medium with boundary conditions that cancel the line integral contributions along the interface, an IE for the magnetic field inside the cavity is obtained. The IE is treated through an entire-domain method of moments (MoM) with cylindrical-harmonic basis functions. The entries of the MoM matrix are determined analytically by utilizing the inverse Fourier transform of Green's function and the Jacobi-Anger formula for interchanging between plane and cylindrical waves. Complex analysis techniques are applied to determine the transmitted, reflected, and radiated field quantities in series forms. The numerical results show that the scattered SPPs' spectra exhibit pronounced wavelength selectivity that is related to the excitation of WG-like cavity modes. It seems feasible to exploit the device as a bandstop or reflective filter or even as an efficient radiating element. In addition, the dependence of transmission on the cavity refractive index endows this structure with a sensing functionality.

  17. Template-Guided Self-Assembly of Discrete Optoplasmonic Molecules and Extended Optoplasmonic Arrays

    Directory of Open Access Journals (Sweden)

    Reinhard Björn M.

    2015-01-01

    Full Text Available The integration of metallic and dielectric building blocks into optoplasmonic structures creates new electromagnetic systems in which plasmonic and photonic modes can interact in the near-, intermediate- and farfield. The morphology-dependent electromagnetic coupling between the different building blocks in these hybrid structures provides a multitude of opportunities for controlling electromagnetic fields in both spatial and frequency domain as well as for engineering the phase landscape and the local density of optical states. Control over any of these properties requires, however, rational fabrication approaches for well-defined metal-dielectric hybrid structures. Template-guided self-assembly is a versatile fabrication method capable of integrating metallic and dielectric components into discrete optoplasmonic structures, arrays, or metasurfaces. The structural flexibility provided by the approach is illustrated by two representative implementations of optoplasmonic materials discussed in this review. In optoplasmonic atoms or molecules optical microcavities (OMs serve as whispering gallery mode resonators that provide a discrete photonic mode spectrum to interact with plasmonic nanostructures contained in the evanescent fields of the OMs. In extended hetero-nanoparticle arrays in-plane scattered light induces geometry-dependent photonic resonances that mix with the localized surface plasmon resonances of the metal nanoparticles.We characterize the fundamental electromagnetic working principles underlying both optoplasmonic approaches and review the fabrication strategies implemented to realize them.

  18. Spin coating and plasma process for 2.5D and hybrid 3D micro-resonators on multilayer polymers

    Science.gov (United States)

    Bêche, B.; Gaviot, E.; Godet, C.; Zebda, A.; Potel, A.; Barbe, J.; Camberlein, L.; Vié, V.; Panizza, P.; Loas, G.; Hamel, C.; Zyss, J.; Huby, N.

    2009-05-01

    We have designed and realized three integrated photonic families of micro-resonators (MR) on multilayer organic materials. Such so-called 2.5D-MR and 3D-MR structures show off radius values ranging from 40 to 200μm. Both first and second families are especially designed on organic multilayer materials and shaped as ring- and disk-MR organics structures arranged upon (and coupled with) a pair of SU8-organic waveguides. The third family is related to hybrid 3D-MR structures composed of spherical glass-MR coupled to organic waveguides by a Langmuir-Blodgett lipid film about three nanometers in thickness. At first, polymer spin coating, surface plasma treatment and selective UV-lithography processes have been developed to realize 2.5D photonic micro-resonators. Secondly, we have designed and characterized photonic-quadripoles made of 3D-glass-MR arranged upon a pair of SU8 waveguides. Such structures are defined by a 4-ports or 4-waveguides coupled by the spherical glass-MR. We have achieved an evanescent photonic coupling between the 3D-MR and the 4-ports structure. Spectral resonances have been measured for 4-whispering gallery-modes (WGM) into such 3D-structures respectively characterized by a 0.97 nm free spectral range (FSR) and a high quality Q-factor up to 4.104.

  19. Engineered analogues of cement/clay interactions in the Tournemire experimental platform (France): a coupled mineralogical and geochemical approach to track tiny disturbances

    International Nuclear Information System (INIS)

    Techer, Isabelle; Michel, Pauline; Tinseau, Elisabeth; Devol-Brown, Isabelle; Bartier, Daniele; Boulvais, Philippe; Suchorski, Krzysztof

    2012-01-01

    A scientific program has been especially established to better understand the high-pH fluids / clay interactions through a mineralogical and geochemical study of three engineered analogues available by means of the IRSN Tournemire experimental platform. This platform, located in Aveyron (France), is based on a tunnel, excavated between 1882 and 1886 through Domerian marls and Toarcian argillites, and is dedicated since 1990 to multidisciplinary research programs. Different contexts presenting the argillite formation in contact with a cementitious material are encountered and are linked to its historical construction and scientific evolution. These rare examples of cement / clay contacts maintained over time scales ranging from a few years to a hundred of years are studied as engineered analogues of a deep geological storage. This approach is moreover completed by experiments (diffusion and advection) performed in laboratory over shorter time and smaller space scales in order to discriminate and control the major parameters involved in such interactions (details are given in another paper). This paper presents the scientific program developed on the three engineered analogues: tunnel walls recovered by lime after excavation; four concreted exploration boreholes; two experimental research galleries excavated in 2003

  20. The measurement of tiny dew droplets at the initial deposition stage and dew point using a phase-shift interference microscope

    Science.gov (United States)

    Shigeaki, Matsumoto

    2003-12-01

    The shape of a dew droplet deposited on the mirror surface of a copper plate was measured accurately using an interference microscope that employed a phase-shift technique. The microscope was constructed by adding a piezoelectric transducer to an interference microscope. A simple method that uses a conventional speaker horn and an optical fibre cable was used to depress any speckle noise. The shape of a dew droplet deposited at dew point on the plate surface with average roughness of 0.1 µm was measured with an accuracy of ± 3 nm. The mass of a tiny dew droplet could be determined from the volume of its shape and was of the order of 10-9 g. The total mass of a dew droplet deposited per unit area and the deposition velocity under a gentle wind were also obtained in a similar way. The total mass was of the order of 10-5 g cm-2 at the beginning of deposition and the deposition velocity ranged from 1 × 10-5 to 6 × 10-5 g cm-2 min-1 at room temperature.