Science.gov

Sample records for passive localization processing

  1. Passive Acoustic Vessel Localization

    NASA Astrophysics Data System (ADS)

    Suwal, Pasang Sherpa

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

  2. Indoor localization using passive RFID

    NASA Astrophysics Data System (ADS)

    Vastianos, George E.; Kyriazanos, Dimitris M.; Segou, Olga E.; Mitilineos, Stelios A.; Thomopoulos, Stelios C. A.

    2011-06-01

    Radio frequency identification (RFID) systems based on passive tags are used successfully in a wide range of object identification applications. However, the increasing needs to meet new demands on applications of localization and tracking create a new field for evolution of the RFID technology. This paper presents the design, implementation, and evaluation of a cost-effective localization system for in-building usage that is able to localize objects that carry passive RFID tags. The RFID reading is performed by a single Reader and an array of directional antennas through multiplexing. Evaluation and experimental results from three localization algorithms based on RSSI are presented.

  3. Adaptive passive fathometer processing.

    PubMed

    Siderius, Martin; Song, Heechun; Gerstoft, Peter; Hodgkiss, William S; Hursky, Paul; Harrison, Chris

    2010-04-01

    Recently, a technique has been developed to image seabed layers using the ocean ambient noise field as the sound source. This so called passive fathometer technique exploits the naturally occurring acoustic sounds generated on the sea-surface, primarily from breaking waves. The method is based on the cross-correlation of noise from the ocean surface with its echo from the seabed, which recovers travel times to significant seabed reflectors. To limit averaging time and make this practical, beamforming is used with a vertical array of hydrophones to reduce interference from horizontally propagating noise. The initial development used conventional beamforming, but significant improvements have been realized using adaptive techniques. In this paper, adaptive methods for this process are described and applied to several data sets to demonstrate improvements possible as compared to conventional processing.

  4. Passive versus active local microrheology in mammalian cells and amoebae

    NASA Astrophysics Data System (ADS)

    Riviere, C.; Gazeau, F.; Marion, S.; Bacri, J.-C.; Wilhelm, C.

    2004-12-01

    We compare in this paper the rotational magnetic microrheology detailed by Marion et al [18] and Wilhelm et al [19] to the passive tracking microrheology. The rotational microrheology has been designed to explore, using magnetic rotating probes, the local intracellular microenvironment of living cells in terms of viscoelasticity. Passive microrheology techniques is based on the analysis of spontaneous diffusive motions of Brownian probes. The dependence of mean square displacement (MSD) with the time then directly reflects the type of movement (sub-, hyper- or diffusive motions). Using the same intracellular probes, we performed two types of measurements (active and passive). Based on the fluctuation-dissipation theorem, one should obtain the same information from the both techniques in a thermally equilibrium system. Interestingly, our measurements differ, and the discordances directly inform on active biological processes, which add to thermally activated fluctuations in our out-of equilibrium systems. In both cell models used, mammalian Hela cells and amoebae Entamoeba Histolytica, a hyper-diffusive regime at a short time is observed, which highlights the presence of an active non-thermal driving force, acting on the probe. However, the nature of this active force in mammalian cells and amoebae is different, according to their different phenotypes. In mammalian cells active processes are governed by the transport, via molecular motors, on the microtubule network. In amoebae, which are highly motile cells free of microtubule network, the active processes are dominated by strong fluxes of cytoplasm driven by extension of pseudopodia, in random directions, leading to an amplitude of motion one order of magnitude higher than for mammalian cells. Figs 7, Refs 32.

  5. Time-Frequency Cardiac Passive Acoustic Localization

    DTIC Science & Technology

    2007-11-02

    by cardiohemic theory [1], [2]. The region Ω3 shows also a good clue for the closure of the mitral valve beneath the principal focus. This focus...signal processing methods for the diagnosis of the heart valve dysfunction and degeneration are strongly established in [1], [2]. However, conventional...pregnant women [6]. Using this system, different �images� corresponding to the various distinct phases of the heart beat; e.g., closure of the mitral and

  6. Stable surface passivation process for compound semiconductors

    DOEpatents

    Ashby, Carol I. H.

    2001-01-01

    A passivation process for a previously sulfided, selenided or tellurated III-V compound semiconductor surface. The concentration of undesired mid-gap surface states on a compound semiconductor surface is reduced by the formation of a near-monolayer of metal-(sulfur and/or selenium and/or tellurium)-semiconductor that is effective for long term passivation of the underlying semiconductor surface. Starting with the III-V compound semiconductor surface, any oxidation present thereon is substantially removed and the surface is then treated with sulfur, selenium or tellurium to form a near-monolayer of chalcogen-semiconductor of the surface in an oxygen-free atmosphere. This chalcogenated surface is then contacted with a solution of a metal that will form a low solubility chalcogenide to form a near-monolayer of metal-chalcogen-semiconductor. The resulting passivating layer provides long term protection for the underlying surface at or above the level achieved by a freshly chalcogenated compound semiconductor surface in an oxygen free atmosphere.

  7. Human sperm rheotaxis: a passive physical process

    PubMed Central

    Zhang, Zhuoran; Liu, Jun; Meriano, Jim; Ru, Changhai; Xie, Shaorong; Luo, Jun; Sun, Yu

    2016-01-01

    A long-standing question in natural reproduction is how mammalian sperm navigate inside female reproductive tract and finally reach the egg cell, or oocyte. Recently, fluid flow was proposed as a long–range guidance cue for sperm navigation. Coitus induces fluid flow from oviduct to uterus, and sperm align themselves against the flow direction and swim upstream, a phenomenon termed rheotaxis. Whether sperm rheotaxis is a passive process dominated by fluid mechanics, or sperm actively sense and adapt to fluid flow remains controversial. Here we report the first quantitative study of sperm flagellar motion during human sperm rheotaxis and provide direct evidence indicating that sperm rheotaxis is a passive process. Experimental results show that there is no significant difference in flagellar beating amplitude and asymmetry between rheotaxis-turning sperm and those sperm swimming freely in the absence of fluid flow. Additionally, fluorescence image tracking shows no Ca2+ influx during sperm rheotaxis turning, further suggesting there is no active signal transduction during human sperm rheotaxis. PMID:27005727

  8. Human sperm rheotaxis: a passive physical process

    NASA Astrophysics Data System (ADS)

    Zhang, Zhuoran; Liu, Jun; Meriano, Jim; Ru, Changhai; Xie, Shaorong; Luo, Jun; Sun, Yu

    2016-03-01

    A long-standing question in natural reproduction is how mammalian sperm navigate inside female reproductive tract and finally reach the egg cell, or oocyte. Recently, fluid flow was proposed as a long–range guidance cue for sperm navigation. Coitus induces fluid flow from oviduct to uterus, and sperm align themselves against the flow direction and swim upstream, a phenomenon termed rheotaxis. Whether sperm rheotaxis is a passive process dominated by fluid mechanics, or sperm actively sense and adapt to fluid flow remains controversial. Here we report the first quantitative study of sperm flagellar motion during human sperm rheotaxis and provide direct evidence indicating that sperm rheotaxis is a passive process. Experimental results show that there is no significant difference in flagellar beating amplitude and asymmetry between rheotaxis-turning sperm and those sperm swimming freely in the absence of fluid flow. Additionally, fluorescence image tracking shows no Ca2+ influx during sperm rheotaxis turning, further suggesting there is no active signal transduction during human sperm rheotaxis.

  9. Local and nonlocal advection of a passive scalar

    NASA Astrophysics Data System (ADS)

    Scott, R. K.

    2006-11-01

    Passive and active scalar mixing is examined in a simple one-parameter family of two-dimensional flows based on quasi-geostrophic dynamics, in which the active scalar, the quasi-geostrophic potential vorticity, is confined to a single horizontal surface (so-called surface quasi-geostrophic dynamics) and in which a passive scalar field is also advected by the (horizontal, two-dimensional) velocity field at a finite distance from the surface. At large distances from the surface the flow is determined by the largest horizontal scales, the flow is spectrally nonlocal, and a chaotic advection-type regime dominates. At small distances, z, scaling arguments suggest a transition wavenumber kc˜1/2z, where the slope of the passive scalar spectrum changes from k-5/3, determined by local dynamics, to k-1, determined by nonlocal dynamics, analogous to the transition to a k-1 slope in the Batchelor regime in three-dimensional turbulence. Direct numerical simulations reproduce the qualitative aspects of this transition. Other characteristics of the simulated scalar fields, such as the relative dominance of coherent or filamentary structures, are also shown to depend strongly on the degree of locality.

  10. Passive detection, characterization, and localization of multiple LFMCW LPI signals

    NASA Astrophysics Data System (ADS)

    Hamschin, Brandon; Clancy, John; Grabbe, Mike; Fortier, Matthew; Novak, John

    2014-06-01

    A method for passive Detection, Characterization, and Localization (DCL) of multiple low power, Linear Frequency Modulated Continuous Wave (LFMCW) (i.e., Low Probability of Intercept (LPI)) signals is proposed. In contrast to other detection and characterization approaches, such as those based on the Wigner-Ville Transform (WVT) 1or the Wigner-Ville Hough Transform (WVHT) ,2 our approach does not begin with a parametric model of the received signal that is specified directly in terms of its LFMCW constituents. Rather, we analyze the signal over time intervals that are short, non-overlapping, and contiguous by modeling it within these intervals as a sum of sinusoidal (i.e., harmonic) components with unknown frequencies, deterministic but unknown amplitudes, unknown order (i.e., number of harmonic components), and unknown noise autocorrelation function. Using this model of the signal, which we refer to as the Short-Time Harmonic Model (STHM), we implement a detection statistic based on Thompson's Method for harmonic analysis,3 which leads to a detection threshold that is a function of False Alarm Probability PFA and not a function of the noise properties. By doing so we reliably detect the presence of multiple LFMCW signals in colored noise without the need for prewhitening, efficiently estimate (i.e., characterize) their parameters, provide estimation error variances for a subset of these parameters, and produce Time-of-Arrival (TOA) estimates that can be used to estimate the geographical location of (i.e., localize) each LFMCW source. Finally, by using the entire time-series we refine these parameter estimates by using them as initial conditions to the Maximum Likelihood Estimator (MLE), which was originally given in1 and later found in2 to be too computationally expensive for multiple LFMCW signals if accurate initial conditions were not available to limit the search space. We demonstrate the performance of our approach via simulation.

  11. The experimental study on the contact process of passive walking

    NASA Astrophysics Data System (ADS)

    Qi, Feng; Bi, Lai-Ye; Wang, Tian-Shu; Li, Jun-Feng

    2012-08-01

    The passive dynamic walking is a new concept of biped walking. Researchers have been working on this area with both theoretical analysis and experimental analysis ever since McGeer. This paper presents our compass-like passive walking model with a new set of testing system. Two gyroscopes are used for measuring the angles of two legs, and ten FlexiForce sensors are used for measuring the contact forces on the feet. We got the experimental data on the passive walking process with the validated testing system. A great emphasis was put on the contact process between the feet and the slope. The contact process of the stance leg was divided into four sections, and differences between the real testing contact process and the classic analytical contact process with no bouncing and slipping were summarized.

  12. Workshop on the Detection, Classification, Localization and Density Estimation of Marine Mammals Using Passive Acoustics - 2015

    DTIC Science & Technology

    2015-09-30

    and Density Estimation of Marine Mammals Using Passive Acoustics - 2015 John A. Hildebrand Scripps Institution of Oceanography UCSD La Jolla...classification, localization and density estimation of marine mammals using passive acoustics , and by doing so advance the state of the art in this field...Passive Acoustics was organized and held at the Scripps Institution of Oceanography (SIO) in July 2015. The objective of ONR support for the

  13. Enhanced Passive and Active Processing of Syllables in Musician Children

    ERIC Educational Resources Information Center

    Chobert, Julie; Marie, Celine; Francois, Clement; Schon, Daniele; Besson, Mireille

    2011-01-01

    The aim of this study was to examine the influence of musical expertise in 9-year-old children on passive (as reflected by MMN) and active (as reflected by discrimination accuracy) processing of speech sounds. Musician and nonmusician children were presented with a sequence of syllables that included standards and deviants in vowel frequency,…

  14. Passive electrical monitoring and localization of fluid leakages from wells

    NASA Astrophysics Data System (ADS)

    Revil, A.; Mao, D.; Haas, A. K.; Karaoulis, M.; Frash, L.

    2015-02-01

    Electrokinetic phenomena are a class of cross-coupling phenomena involving the relative displacement between the pore water (together with the electrical diffuse layer) with respect to the solid phase of a porous material. We demonstrate that electrical fields of electrokinetic nature can be associated with fluid leakages from wells. These leakages can be remotely monitored and the resulting signals used to localize their causative source distribution both in the laboratory and in field conditions. The first laboratory experiment (Experiment #1) shows how these electrical fields can be recorded at the surface of a cement block during the leakage of a brine from a well. The measurements were performed with a research-grade medical electroencephalograph and were inverted using a genetic algorithm to localize the causative source of electrical current and therefore, localize the leak in the block. Two snapshots of electrical signals were used to show how the leak evolved over time. The second experiment (Experiment #2) was performed to see if we could localize a pulse water injection from a shallow well in field conditions in the case of a heterogeneous subsurface. We used the same equipment as in Experiment #1 and processed the data with a trend removal algorithm, picking the amplitude from 24 receiver channels just after the water injection. The amplitude of the electric signals changed from the background level indicating that a volume of water was indeed flowing inside the well into the surrounding soil and then along the well. We used a least-square inversion algorithm to invert a snapshot of the electrical potential data at the injection time to localize the source of the self-potential signals. The inversion results show positive potential anomalies in the vicinity of the well. For both experiments, forward numerical simulations of the problem using a finite element package were performed in order to assess the underlying physics of the causative source of the

  15. Localization of low-frequency coherent sound sources with compressive beamforming-based passive synthetic aperture.

    PubMed

    Lei, Zhixiong; Yang, Kunde; Duan, Rui; Xiao, Peng

    2015-04-01

    The localization of low-frequency coherent sources requires a proper aperture to ensure a high spatial resolution. Attaining a large aperture is difficult in practice when the conditions involved are limited. This letter investigated a compressive beamforming-based passive synthetic aperture approach with a reference sensor in a fixed position. Localization findings on acoustic sources in a semi-anechoic chamber were compared with conventional beamforming, compressive beamforming, passive synthetic aperture, and compressive beamforming-based passive synthetic aperture. Results suggest that the proposed method can produce a higher spatial resolution and higher detection ability than the others.

  16. Non-invasive Technology to Study Local Passivity Breakdown of Metal Alloys in Aqueous Media

    SciTech Connect

    Alan M. Shipley

    2005-03-09

    Little is known about the basic mechanisms of passive oxide breakdown, repair, and localized corrosion of metals. A non-invasive instrument and methods have been developed to study local events and mechanisms that initiate passivity breakdown and subsequent corrosion of metals in aqueous media. The ''difference viewer imaging technique'' (DVIT) is a rapid, real time, non-invasive assay to study metal surfaces in corrosive solutions. It has a spatial resolution of less than 10.0 ?m (1cm x 1cm sample, 1000 x 1000 pixel CCD) to observe initial corrosion processes of the order of seconds. DVIT is a software-controlled video microscopy system and methods to collect and analyze pixel changes in video images. These images are recorded from a digital CCD video camera and frame grabber package using visible light for illumination. The DVIT system detects changes in video images that represent initial corrosive events that lead to passivity breakdown and re-passivation on metal surfaces in situ. This visual technique is easy to use and apply. It compliments other metal surface measurement techniques and can be used simultaneously with them. DVIT has proven to be more sensitive in detecting changes than scanning microelectrode techniques. DVIT is also much easier than other methods to apply and operate. It has the further advantage of providing a real time image of the entire metal surface under study instead of waiting for a microelectrode to scan a number of data points over a sample then plot the results. This project has fulfilled all specifications as outlined in the Department of Energy solicitation responsible for this grant application and award and exceeded a number of the specifications. Applicable Electronics, Inc. now has a marketable instrument and software package available for sale now. Further development of the system will be ongoing as driven by customer needs and discoveries. This technology has immediate applications in corrosion labs to further study

  17. Local-Level Prognostics Health Management Systems Framework for Passive AdvSMR Components. Interim Report

    SciTech Connect

    Ramuhalli, Pradeep; Roy, Surajit; Hirt, Evelyn H.; Pardini, Allan F.; Jones, Anthony M.; Deibler, John E.

    2014-09-12

    This report describes research results to date in support of the integration and demonstration of diagnostics technologies for prototypical AdvSMR passive components (to establish condition indices for monitoring) with model-based prognostics methods. The focus of the PHM methodology and algorithm development in this study is at the localized scale. Multiple localized measurements of material condition (using advanced nondestructive measurement methods), along with available measurements of the stressor environment, enhance the performance of localized diagnostics and prognostics of passive AdvSMR components and systems.

  18. Image processing techniques for passive millimeter-wave imaging

    NASA Astrophysics Data System (ADS)

    Lettington, Alan H.; Gleed, David G.

    1998-08-01

    We present our results on the application of image processing techniques for passive millimeter-wave imaging and discuss possible future trends. Passive millimeter-wave imaging is useful in poor weather such as in fog and cloud. Its spatial resolution, however, can be restricted due to the diffraction limit of the front aperture. Its resolution may be increased using super-resolution techniques but often at the expense of processing time. Linear methods may be implemented in real time but non-linear methods which are required to restore missing spatial frequencies are usually more time consuming. In the present paper we describe fast super-resolution techniques which are potentially capable of being applied in real time. Associated issues such as reducing the influence of noise and improving recognition capability will be discussed. Various techniques have been used to enhance passive millimeter wave images giving excellent results and providing a significant quantifiable increase in spatial resolution. Examples of applying these techniques to imagery will be given.

  19. Delivery of video-on-demand services using local storages within passive optical networks.

    PubMed

    Abeywickrama, Sandu; Wong, Elaine

    2013-01-28

    At present, distributed storage systems have been widely studied to alleviate Internet traffic build-up caused by high-bandwidth, on-demand applications. Distributed storage arrays located locally within the passive optical network were previously proposed to deliver Video-on-Demand services. As an added feature, a popularity-aware caching algorithm was also proposed to dynamically maintain the most popular videos in the storage arrays of such local storages. In this paper, we present a new dynamic bandwidth allocation algorithm to improve Video-on-Demand services over passive optical networks using local storages. The algorithm exploits the use of standard control packets to reduce the time taken for the initial request communication between the customer and the central office, and to maintain the set of popular movies in the local storage. We conduct packet level simulations to perform a comparative analysis of the Quality-of-Service attributes between two passive optical networks, namely the conventional passive optical network and one that is equipped with a local storage. Results from our analysis highlight that strategic placement of a local storage inside the network enables the services to be delivered with improved Quality-of-Service to the customer. We further formulate power consumption models of both architectures to examine the trade-off between enhanced Quality-of-Service performance versus the increased power requirement from implementing a local storage within the network.

  20. Acoustic emission localization in plates with dispersion and reverberations using sparse PZT sensors in passive mode

    NASA Astrophysics Data System (ADS)

    Perelli, Alessandro; De Marchi, Luca; Marzani, Alessandro; Speciale, Nicolò

    2012-02-01

    A strategy for the localization of acoustic emissions (AE) in plates with dispersion and reverberation is proposed. The procedure exploits signals received in passive mode by sparse conventional piezoelectric transducers and a three-step processing framework. The first step consists in a signal dispersion compensation procedure, which is achieved by means of the warped frequency transform. The second step concerns the estimation of the differences in arrival time (TDOA) of the acoustic emission at the sensors. Complexities related to reflections and plate resonances are overcome via a wavelet decomposition of cross-correlating signals where the mother function is designed by a synthetic warped cross-signal. The magnitude of the wavelet coefficients in the warped distance-frequency domain, in fact, precisely reveals the TDOA of an acoustic emission at two sensors. Finally, in the last step the TDOA data are exploited to locate the acoustic emission source through hyperbolic positioning. The proposed procedure is tested with a passive network of three/four piezo-sensors located symmetrically and asymmetrically with respect to the plate edges. The experimentally estimated AE locations are close to those theoretically predicted by the Cramèr-Rao lower bound.

  1. A hybrid passive localization method under strong interference with a preliminary experimental demonstration

    NASA Astrophysics Data System (ADS)

    Lei, Bo; Yang, Yixin; Yang, Kunde; Wang, Yong; Shi, Yang

    2016-12-01

    Strong interference exists in many passive localization problems and may lead to the inefficacy of traditional localization methods. In this study, a hybrid passive localization method is proposed to address strong interference. This method combines generalized cross-correlation and interference cancellation for time-difference-of-arrival (TDOA) measurement, followed by a time-delay-based iterative localization method. The proposed method is applied to a preliminary experiment using three hydrophones. The TDOAs estimated by the proposed method are compared with those obtained by the particle filtering method. Results show that the positions are in agreement when the TDOAs are accurately obtained. Furthermore, the proposed method is more capable of localization in the presence of a strong moving jamming source.

  2. Surface passivation process of compound semiconductor material using UV photosulfidation

    DOEpatents

    Ashby, Carol I. H.

    1995-01-01

    A method for passivating compound semiconductor surfaces by photolytically disrupting molecular sulfur vapor with ultraviolet radiation to form reactive sulfur which then reacts with and passivates the surface of compound semiconductors.

  3. Passive acoustic source localization using sources of opportunity.

    PubMed

    Verlinden, Christopher M A; Sarkar, J; Hodgkiss, W S; Kuperman, W A; Sabra, K G

    2015-07-01

    The feasibility of using data derived replicas from ships of opportunity for implementing matched field processing is demonstrated. The Automatic Identification System (AIS) is used to provide the library coordinates for the replica library and a correlation based processing procedure is used to overcome the impediment that the replica library is constructed from sources with different spectra and will further be used to locate another source with its own unique spectral structure. The method is illustrated with simulation and then verified using acoustic data from a 2009 experiment for which AIS information was retrieved from the United States Coast Guard Navigation Center Nationwide AIS database.

  4. Apparatus and process for passivating an SRF cavity

    DOEpatents

    Myneni, Ganapati Rao; Wallace, John P

    2014-12-02

    An apparatus and process for the production of a niobium cavity exhibiting high quality factors at high gradients is provided. The apparatus comprises a first chamber positioned within a second chamber, an RF generator and vacuum pumping systems. The process comprises placing the niobium cavity in a first chamber of the apparatus; thermally treating the cavity by high temperature in the first chamber while maintaining high vacuum in the first and second chambers; and applying a passivating thin film layer to a surface of the cavity in the presence of a gaseous mixture and an RF field. Further a niobium cavity exhibiting high quality factors at high gradients produced by the method of the invention is provided.

  5. New process of silicon carbide purification intended for silicon passivation

    NASA Astrophysics Data System (ADS)

    Barbouche, M.; Zaghouani, R. Benabderrahmane; Benammar, N. E.; Aglieri, V.; Mosca, M.; Macaluso, R.; Khirouni, K.; Ezzaouia, H.

    2017-01-01

    In this work, we report on a new, efficient and low cost process of silicon carbide (SiC) powder purification intended to be used in photovoltaic applications. This process consists on the preparation of porous silicon carbide layers followed by a photo-thermal annealing under oxygen atmosphere and chemical treatment. The effect of etching time on impurities removal efficiency was studied. Inductively coupled plasma atomic emission spectrometry (ICP-AES) results showed that the best result was achieved for an etching time of 10 min followed by gettering at 900 °C during 1 h. SiC purity is improved from 3N (99.9771%) to 4N (99.9946%). Silicon carbide thin films were deposited onto silicon substrates by pulsed laser deposition technique (PLD) using purified SiC powder as target. Significant improvement of the minority carrier lifetime was obtained encouraging the use of SiC as a passivation layer for silicon.

  6. Systematic satellite observations of the impact of aerosols from passive volcanic degassing on local cloud properties

    NASA Astrophysics Data System (ADS)

    Ebmeier, S. K.; Sayer, A. M.; Grainger, R. G.; Mather, T. A.; Carboni, E.

    2014-10-01

    The impact of volcanic emissions, especially from passive degassing and minor explosions, is a source of uncertainty in estimations of aerosol indirect effects. Observations of the impact of volcanic aerosol on clouds contribute to our understanding of both present-day atmospheric properties and of the pre-industrial baseline necessary to assess aerosol radiative forcing. We present systematic measurements over several years at multiple active and inactive volcanic islands in regions of low present-day aerosol burden. The time-averaged indirect aerosol effects within 200 km downwind of island volcanoes are observed using Moderate Resolution Imaging Spectroradiometer (MODIS, 2002-2013) and Advanced Along-Track Scanning Radiometer (AATSR, 2002-2008) data. Retrievals of aerosol and cloud properties at Kīlauea (Hawai'i), Yasur (Vanuatu) and Piton de la Fournaise (la Réunion) are rotated about the volcanic vent to be parallel to wind direction, so that upwind and downwind retrievals can be compared. The emissions from all three volcanoes - including those from passive degassing, Strombolian activity and minor explosions - lead to measurably increased aerosol optical depth downwind of the active vent. Average cloud droplet effective radius is lower downwind of the volcano in all cases, with the peak difference ranging from 2-8 μm at the different volcanoes in different seasons. Estimations of the difference in Top of Atmosphere upward Short Wave flux upwind and downwind of the active volcanoes from NASA's Clouds and the Earth's Radiant Energy System (CERES) suggest a downwind elevation of between 10 and 45 Wm-2 at distances of 150-400 km from the volcano, with much greater local (< 80 km) effects. Comparison of these observations with cloud properties at isolated islands without degassing or erupting volcanoes suggests that these patterns are not purely orographic in origin. Our observations of unpolluted, isolated marine settings may capture processes similar to

  7. Systematic Satellite Observations of the Impact of Aerosols from Passive Volcanic Degassing on Local Cloud Properties

    NASA Technical Reports Server (NTRS)

    Ebmeier, S.K.; Sayer, Andrew M.; Grainger, R. G.; Mather, T. A.; Carboni, E.

    2014-01-01

    The impact of volcanic emissions, especially from passive degassing and minor explosions, is a source of uncertainty in estimations of aerosol indirect effects. Observations of the impact of volcanic aerosol on clouds contribute to our understanding of both present-day atmospheric properties and of the pre-industrial baseline necessary to assess aerosol radiative forcing. We present systematic measurements over several years at multiple active and inactive volcanic islands in regions of low present-day aerosol burden. The timeaveraged indirect aerosol effects within 200 kilometers downwind of island volcanoes are observed using Moderate Resolution Imaging Spectroradiometer (MODIS, 2002-2013) and Advanced Along-Track Scanning Radiometer (AATSR, 2002- 2008) data. Retrievals of aerosol and cloud properties at Kilauea (Hawaii), Yasur (Vanuatu) and Piton de la Fournaise (la Reunion) are rotated about the volcanic vent to be parallel to wind direction, so that upwind and downwind retrievals can be compared. The emissions from all three volcanoes - including those from passive degassing, Strombolian activity and minor explosions - lead to measurably increased aerosol optical depth downwind of the active vent. Average cloud droplet effective radius is lower downwind of the volcano in all cases, with the peak difference ranging from 2 - 8 micrometers at the different volcanoes in different seasons. Estimations of the difference in Top of Atmosphere upward Short Wave flux upwind and downwind of the active volcanoes from NASA's Clouds and the Earth's Radiant Energy System (CERES) suggest a downwind elevation of between 10 and 45 Watts per square meter at distances of 150 - 400 kilometers from the volcano, with much greater local (less than 80 kilometers) effects. Comparison of these observations with cloud properties at isolated islands without degassing or erupting volcanoes suggests that these patterns are not purely orographic in origin. Our observations of unpolluted

  8. Sound localization with communications headsets: comparison of passive and active systems.

    PubMed

    Abel, Sharon M; Tsang, Suzanne; Boyne, Stephen

    2007-01-01

    Studies have demonstrated that conventional hearing protectors interfere with sound localization. This research examines possible benefits from advanced communications devices. Horizontal plane sound localization was compared in normal-hearing males with the ears unoccluded and fitted with Peltor H10A passive attenuation earmuffs, Racal Slimgard II communications muffs in active noise reduction (ANR) and talk-through-circuitry (TTC) modes and Nacre QUIETPRO TM communications earplugs in off (passive attenuation) and push-to-talk (PTT) modes. Localization was assessed using an array of eight loudspeakers, two in each spatial quadrant. The stimulus was 75 dB SPL, 300-ms broadband noise. One block of 120 forced-choice loudspeaker identification trials was presented in each condition. Subjects responded using a laptop response box with a set of eight microswitches in the same configuration as the speaker array. A repeated measures ANOVA was applied to the dataset. The results reveal that the overall percent correct response was highest in the unoccluded condition (94%). A significant reduction of 24% was observed for the communications devices in TTC and PTT modes and a reduction of 49% for the passive muff and plug and muff with ANR. Disruption in performance was due to an increase in front-back reversal errors for mirror image spatial positions. The results support the conclusion that communications devices with advanced technologies are less detrimental to directional hearing than conventional, passive, limited amplification and ANR devices.

  9. Fabrication of multilayer passive electric components using inkjet printing and low temperature laser processing on polymer

    NASA Astrophysics Data System (ADS)

    Ko, Seung Hwan; Chung, Jaewon; Pan, Heng; Grigoropoulos, Costas P.; Poulikakos, Dimos

    2006-02-01

    The low temperature fabrication of passive electrical components (conductor, capacitor) on the flexible polymer substrate is presented in this paper. A drop-on-demand (DOD) ink-jetting system was used to print gold nano-particles suspended in Alpha-Terpineol solvent and PVP in PGMEA solvent to fabricate passive electrical components on flexible polymer substrate. Short pulsed laser ablation enabled finer electrical components to overcome limitation of inkjet process. Continuous Argon ion laser was irradiated locally to evaporate carrier solvent as well as to sinter gold nano-particles. In addition, a self alignment technique for PVP layer was demonstrated taking advantage of the deliberate modification of surface wetting characteristics. Finally, a new selective ablation of multilayered gold nanoparticle film was demonstrated using the ablation threshold difference for sintered and non sintered gold nanoparticles.

  10. Evolving uses of passive seismic arrays from continental to local scales

    NASA Astrophysics Data System (ADS)

    Schmandt, B.

    2014-12-01

    Portable passive seismic surveys are generally used to sample scales and locations that are not practical with long-term observatories, but are fundamental to studying Earth systems. The breadth of uses and designs of portable passive surveys is expanding rapidly as result of advances in instrumentation and analysis. Examples from recent passive surveys will be used illustrate how they are bringing new constraint to systems spanning continental to local scales. At continental scale EarthScope's USArray is providing a view of the transition zone between the upper and lower mantle that facilitates integration of seismology, geodynamics, and mineral physics. Recently recognized correlations between mantle flow and abrupt velocity decreases in the top of the lower mantle are consistent with laboratory constraints on the consequences of volatile cycling in the deep Earth. Arrays with similar numbers of seismometers (~103) are also being used in a passive mode on much smaller scales. The Long Beach 3D survey conducted by NodalSeismic in 2011 covered only 7x10 km in southern California with about 5,000 seismometers. The instruments were optimized for recording high frequencies (>10 Hz), but they also successfully recorded local and teleseismic earthquakes. Delay time and amplitude maps for earthquake body-waves revealed coherent structural variations at scales as small as about 400 m. Such dense sampling of teleseismic earthquake wave fields yielded new constraint on localized deep crustal deformation underlying the tectonic boundary between mainland California and the rifted Inner Continental Borderland. The utility of passive data from the Long Beach 3D survey partly motivated a recent deployment of more than 900 exploration industry seismometers to record continuously for 2 weeks at Mt. St. Helens volcano in Washington in 2014. New observations of the >50 local earthquakes recorded within the Mt. St. Helens array will also be presented.

  11. Passive millimeter-wave camera with interferometric processing

    NASA Astrophysics Data System (ADS)

    Nohmi, Hitoshi; Ohnishi, Seiki; Kujubu, Osamu

    2006-05-01

    A proto-type passive millimeter-wave (MMW) camera with interferometric processing has been developed. The purpose is to confirm the feasibility of the interferometric MMW camera and to study the characteristics of MMW images. In this paper, the principle and the feature of the interferometric MMW camera is described. Also, the hardware configuration and the image processing algorithm are presented. This proto-type camera is comprised of the minimum configuration as an interferometric imager which consists of two sets of a W-band front end with a horn antenna, a receiver, and an A/D converter, a high-speed processing hardware, and a computer. The position of these two antennas with W-band front-end moves on the precision linear slider in horizontal and vertical axis. The coherently amplified two channel signals are digitized and processed in the hardware processor. The process is comprised of phase error compensation, correlation of all combination of each axis data, and integration to improve the signal to noise ratio. The computer input the integrated data to make an image by matched filter processing. The integration time is from 1mS to 10S depending on required integration gain. The maximum synthesized antenna aperture size is 1m for horizontal axis and 50cm for vertical axis. Because it takes certain time to receive by the moving antennas, only the targets without motion are imaged by this proto-type camera. The processed images will be shown. Also, future plan for a real-time camera using this technique is presented.

  12. Protection Switching and Local Area Network Emulation in Passive Optical Networks

    NASA Astrophysics Data System (ADS)

    Nadarajah, Nishaanthan; Wong, Elaine; Attygalle, Manik; Nirmalathas, Ampalavanapillai Thas

    2006-05-01

    This paper proposes and experimentally demonstrates an automatic-protection-switching (APS) mechanism against distribution fiber breaks in passive optical networks (PONs). The protection of optical-network units (ONUs) that are located at the customer premises is carried out by monitoring the distribution fiber using the traffic that is transported among the customers in the PON. This configuration emulates a local area network (LAN) over the existing PON while facilitating the switching of signal transmissions to a predetermined protection path in an event of a distribution fiber break. As failure detection and APS are performed independently by each ONU in a distributed manner, the processing complexities and delays are reduced at the central office (CO). The restoration of the traffic transported between the CO and an ONU in the event of the distribution fiber break is performed by interconnecting adjacent ONUs and carrying out signal transmissions via an independent but interconnected ONU. Such a protection mechanism enables multiple adjacent ONUs to be simultaneously protected by a single ONU utilizing its maximum available bandwidth. This paper experimentally verifies the feasibility of the proposed protection mechanism in conjunction with two different LAN-emulation schemes with a 1.25-Gb/s upstream baseband transmission to the CO and a 155-Mb/s LAN data transmission on a radio-frequency carrier. The experimental results obtained from both schemes are compared, and the power budgets are calculated to analyze the scalability of each scheme.

  13. Electrical addressing and temporal tweezing of localized pulses in passively-mode-locked semiconductor lasers

    NASA Astrophysics Data System (ADS)

    Camelin, P.; Javaloyes, J.; Marconi, M.; Giudici, M.

    2016-12-01

    We show that the pumping current is a convenient parameter for manipulating the temporal localized structures (LSs), also called localized pulses, found in passively-mode-locked vertical-cavity surface-emitting lasers. While short electrical pulses can be used for writing and erasing individual LSs, we demonstrate that a current modulation introduces a temporally evolving parameter landscape allowing one to control the position and the dynamics of LSs. We show that the localized pulse drifting speed in this landscape depends almost exclusively on the local parameter value instead of depending on the landscape gradient, as shown in quasi-instantaneous media. This experimental observation is theoretically explained by the causal response time of the semiconductor carriers that occurs on a finite time scale and breaks the parity invariance along the cavity, thus leading to a different paradigm for temporal tweezing of localized pulses. Different modulation waveforms are applied for describing exhaustively this paradigm. Starting from a generic model of passive mode locking based upon delay differential equations, we deduce the effective equations of motion for these LSs in a time-dependent current landscape.

  14. Localized electrical fine tuning of passive microwave and radio frequency devices

    DOEpatents

    Findikoglu, Alp T.

    2001-04-10

    A method and apparatus for the localized electrical fine tuning of passive multiple element microwave or RF devices in which a nonlinear dielectric material is deposited onto predetermined areas of a substrate containing the device. An appropriate electrically conductive material is deposited over predetermined areas of the nonlinear dielectric and the signal line of the device for providing electrical contact with the nonlinear dielectric. Individual, adjustable bias voltages are applied to the electrically conductive material allowing localized electrical fine tuning of the devices. The method of the present invention can be applied to manufactured devices, or can be incorporated into the design of the devices so that it is applied at the time the devices are manufactured. The invention can be configured to provide localized fine tuning for devices including but not limited to coplanar waveguides, slotline devices, stripline devices, and microstrip devices.

  15. Effect of excimer laser annealing on a-InGaZnO thin-film transistors passivated by solution-processed hybrid passivation layers

    NASA Astrophysics Data System (ADS)

    Bermundo, Juan Paolo; Ishikawa, Yasuaki; Fujii, Mami N.; Nonaka, Toshiaki; Ishihara, Ryoichi; Ikenoue, Hiroshi; Uraoka, Yukiharu

    2016-01-01

    We demonstrate the use of excimer laser annealing (ELA) as a low temperature annealing alternative to anneal amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) passivated by a solution-processed hybrid passivation layer. Usually, a-IGZO is annealed using thermal annealing at high temperatures of up to 400 °C. As an alternative to high temperature thermal annealing, two types of ELA, XeCl (308 nm) and KrF (248 nm) ELA, are introduced. Both ELA types enhanced the electrical characteristics of a-IGZO TFTs leading to a mobility improvement of ~13 cm2 V-1 s-1 and small threshold voltage which varied from ~0-3 V. Furthermore, two-dimensional heat simulation using COMSOL Multiphysics was used to identify possible degradation sites, analyse laser heat localization, and confirm that the substrate temperature is below 50 °C. The two-dimensional heat simulation showed that the substrate temperature remained at very low temperatures, less than 30 °C, during ELA. This implies that any flexible material can be used as the substrate. These results demonstrate the large potential of ELA as a low temperature annealing alternative for already-passivated a-IGZO TFTs.

  16. Regularization of Localized Degradation Processes

    DTIC Science & Technology

    1996-12-28

    order to assess the regularization properties of non-classical micropolar Cosserat continua which feature non-symmetric stress and strain tensors because...of the presence of couple-stresses and micro-curvatures. It was shown that micropolar media may only exhibit localized failure in the form of tensile

  17. Spatial Distribution of Lead Iodide and Local Passivation on Organo-Lead Halide Perovskite.

    PubMed

    Chen, Sheng; Wen, Xiaoming; Yun, Jae S; Huang, Shujuan; Green, Martin; Jeon, Nam Joong; Yang, Woon Seok; Noh, Jun Hong; Seo, Jangwon; Seok, Sang Il; Ho-Baillie, Anita

    2017-02-22

    We identify nanoscale spatial distribution of PbI2 on the (FAPbI3)0.85(MAPbBr3)0.15 perovskite thin film and investigate the local passivation effect using confocal based optical microscopy of steady state and time-resolved photoluminescence (PL). Different from a typical scanning electron microscope (SEM) morphology study, confocal based PL spectroscopy and microscopy allow researchers to map the morphologies of both perovskite and PbI2 grains simultaneously, by selectively detecting their characteristic fluorescent bands using band-pass filters. In this work, we compare the perovskite samples without and with excess PbI2 incorporation and unambiguously reveal PbI2 distribution for the PbI2-rich sample. In addition, using the nanoscale time-resolved PL technique we show that the PbI2-rich regions exhibit longer lifetime due to suppressed defect trapping, compared to the PbI2-poor regions. The measurement on the PbI2-rich sample indicates that the passivation effect of PbI2 in perovskite film is effective, especially in localized regions. Hence, this finding is important for further improvement of the solar cells by considering the strategy of excess PbI2 incorporation.

  18. Improved passive optical network architectures to support local area network emulation and protection

    NASA Astrophysics Data System (ADS)

    Wong, Elaine; Nadarajah, Nishaanthan; Chae, Chang-Joon; Nirmalathas, Ampalavanapillai; Attygalle, Sanjeewa M.

    2006-01-01

    We describe two optical layer schemes which simultaneously facilitate local area network emulation and automatic protection switching against distribution fiber breaks in passive optical networks. One scheme employs a narrowband fiber Bragg grating placed close to the star coupler in the feeder fiber of the passive optical network, while the other uses an additional short length distribution fiber from the star coupler to each customer for the redirection of the customer traffic. Both schemes use RF subcarrier multiplexed transmission for intercommunication between customers in conjunction with upstream access to the central office at baseband. Failure detection and automatic protection switching are performed independently by each optical network unit that is located at the customer premises in a distributed manner. The restoration of traffic transported between the central office and an optical network unit in the event of the distribution fiber break is performed by interconnecting adjacent optical network units and carrying out signal transmissions via an independent but interconnected optical network unit. Such a protection mechanism enables multiple adjacent optical network units to be simultaneously protected by a single optical network unit utilizing its maximum available bandwidth. We experimentally verify the feasibility of both schemes with 1.25 Gb/s upstream baseband transmission to the central office and 155 Mb/s local area network data transmission on a RF subcarrier frequency. The experimental results obtained from both schemes are compared, and the power budgets are calculated to analyze the scalability of each scheme.

  19. Passive RF Tomography: Signal Processing and Experimental Validation

    DTIC Science & Technology

    2014-03-27

    medical tomography using x - ray as source of radiation and radar imaging , leading to RF tomography and its passive mode of 7...scene of interest to reconstruct a high resolution image of the scene. In x - ray computed tomography (CT), a three- dimensional image of an object is...differences between x - ray CT and RF tomography are as follows: First, medical x - ray uses x - ray , which has frequencies above 30 petahertz, as

  20. Passive acoustic mapping of magnetic microbubbles for cavitation enhancement and localization

    NASA Astrophysics Data System (ADS)

    Crake, Calum; de Saint Victor, Marie; Owen, Joshua; Coviello, Christian; Collin, Jamie; Coussios, Constantin-C.; Stride, Eleanor

    2015-01-01

    Magnetic targeting of microbubbles functionalized with superparamagnetic nanoparticles has been demonstrated previously for diagnostic (B-mode) ultrasound imaging and shown to enhance gene delivery in vitro and in vivo. In the present work, passive acoustic mapping (PAM) was used to investigate the potential of magnetic microbubbles for localizing and enhancing cavitation activity under focused ultrasound. Suspensions of magnetic microbubbles consisting of 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), air and 10 nm diameter iron oxide nanoparticles were injected into a tissue mimicking phantom at different flow velocities (from 0 to 50 mm s-1) with or without an applied magnetic field. Microbubbles were excited using a 500 kHz single element focused transducer at peak negative focal pressures of 0.1-1.0 MPa, while a 64 channel imaging array passively recorded their acoustic emissions. Magnetic localization of microbubble-induced cavitation activity was successfully achieved and could be resolved using PAM as a shift in the spatial distribution and increases in the intensity and sustainability of cavitation activity under the influence of a magnetic field. Under flow conditions at shear rates of up to 100 s-1 targeting efficacy was maintained. Application of a magnetic field was shown to consistently increase the energy of cavitation emissions by a factor of 2-5 times over the duration of exposures compared to the case without targeting, which was approximately equivalent to doubling the injected microbubble dose. These results suggest that magnetic targeting could be used to localize and increase the concentration of microbubbles and hence cavitation activity for a given systemic dose of microbubbles or ultrasound intensity.

  1. Passive acoustic mapping of magnetic microbubbles for cavitation enhancement and localization.

    PubMed

    Crake, Calum; Victor, Marie de Saint; Owen, Joshua; Coviello, Christian; Collin, Jamie; Coussios, Constantin-C; Stride, Eleanor

    2015-01-21

    Magnetic targeting of microbubbles functionalized with superparamagnetic nanoparticles has been demonstrated previously for diagnostic (B-mode) ultrasound imaging and shown to enhance gene delivery in vitro and in vivo. In the present work, passive acoustic mapping (PAM) was used to investigate the potential of magnetic microbubbles for localizing and enhancing cavitation activity under focused ultrasound. Suspensions of magnetic microbubbles consisting of 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), air and 10 nm diameter iron oxide nanoparticles were injected into a tissue mimicking phantom at different flow velocities (from 0 to 50 mm s(-1)) with or without an applied magnetic field. Microbubbles were excited using a 500 kHz single element focused transducer at peak negative focal pressures of 0.1-1.0 MPa, while a 64 channel imaging array passively recorded their acoustic emissions. Magnetic localization of microbubble-induced cavitation activity was successfully achieved and could be resolved using PAM as a shift in the spatial distribution and increases in the intensity and sustainability of cavitation activity under the influence of a magnetic field. Under flow conditions at shear rates of up to 100 s(-1) targeting efficacy was maintained. Application of a magnetic field was shown to consistently increase the energy of cavitation emissions by a factor of 2-5 times over the duration of exposures compared to the case without targeting, which was approximately equivalent to doubling the injected microbubble dose. These results suggest that magnetic targeting could be used to localize and increase the concentration of microbubbles and hence cavitation activity for a given systemic dose of microbubbles or ultrasound intensity.

  2. Skin blood flow and local temperature independently modify sweat rate during passive heat stress in humans.

    PubMed

    Wingo, Jonathan E; Low, David A; Keller, David M; Brothers, R Matthew; Shibasaki, Manabu; Crandall, Craig G

    2010-11-01

    Sweat rate (SR) is reduced in locally cooled skin, which may result from decreased temperature and/or parallel reductions in skin blood flow. The purpose of this study was to test the hypotheses that decreased skin blood flow and decreased local temperature each independently attenuate sweating. In protocols I and II, eight subjects rested supine while wearing a water-perfused suit for the control of whole body skin and internal temperatures. While 34°C water perfused the suit, four microdialysis membranes were placed in posterior forearm skin not covered by the suit to manipulate skin blood flow using vasoactive agents. Each site was instrumented for control of local temperature and measurement of local SR (capacitance hygrometry) and skin blood flow (laser-Doppler flowmetry). In protocol I, two sites received norepinephrine to reduce skin blood flow, while two sites received Ringer solution (control). All sites were maintained at 34°C. In protocol II, all sites received 28 mM sodium nitroprusside to equalize skin blood flow between sites before local cooling to 20°C (2 sites) or maintenance at 34°C (2 sites). In both protocols, individuals were then passively heated to increase core temperature ~1°C. Both decreased skin blood flow and decreased local temperature attenuated the slope of the SR to mean body temperature relationship (2.0 ± 1.2 vs. 1.0 ± 0.7 mg·cm(-2)·min(-1)·°C(-1) for the effect of decreased skin blood flow, P = 0.01; 1.2 ± 0.9 vs. 0.07 ± 0.05 mg·cm(-2)·min(-1)·°C(-1) for the effect of decreased local temperature, P = 0.02). Furthermore, local cooling delayed the onset of sweating (mean body temperature of 37.5 ± 0.4 vs. 37.6 ± 0.4°C, P = 0.03). These data demonstrate that local cooling attenuates sweating by independent effects of decreased skin blood flow and decreased local skin temperature.

  3. Passive Sensor Integration for Vehicle Self-Localization in Urban Traffic Environment †

    PubMed Central

    Gu, Yanlei; Hsu, Li-Ta; Kamijo, Shunsuke

    2015-01-01

    This research proposes an accurate vehicular positioning system which can achieve lane-level performance in urban canyons. Multiple passive sensors, which include Global Navigation Satellite System (GNSS) receivers, onboard cameras and inertial sensors, are integrated in the proposed system. As the main source for the localization, the GNSS technique suffers from Non-Line-Of-Sight (NLOS) propagation and multipath effects in urban canyons. This paper proposes to employ a novel GNSS positioning technique in the integration. The employed GNSS technique reduces the multipath and NLOS effects by using the 3D building map. In addition, the inertial sensor can describe the vehicle motion, but has a drift problem as time increases. This paper develops vision-based lane detection, which is firstly used for controlling the drift of the inertial sensor. Moreover, the lane keeping and changing behaviors are extracted from the lane detection function, and further reduce the lateral positioning error in the proposed localization system. We evaluate the integrated localization system in the challenging city urban scenario. The experiments demonstrate the proposed method has sub-meter accuracy with respect to mean positioning error. PMID:26633420

  4. Passive Sensor Integration for Vehicle Self-Localization in Urban Traffic Environment.

    PubMed

    Gu, Yanlei; Hsu, Li-Ta; Kamijo, Shunsuke

    2015-12-03

    This research proposes an accurate vehicular positioning system which can achieve lane-level performance in urban canyons. Multiple passive sensors, which include Global Navigation Satellite System (GNSS) receivers, onboard cameras and inertial sensors, are integrated in the proposed system. As the main source for the localization, the GNSS technique suffers from Non-Line-Of-Sight (NLOS) propagation and multipath effects in urban canyons. This paper proposes to employ a novel GNSS positioning technique in the integration. The employed GNSS technique reduces the multipath and NLOS effects by using the 3D building map. In addition, the inertial sensor can describe the vehicle motion, but has a drift problem as time increases. This paper develops vision-based lane detection, which is firstly used for controlling the drift of the inertial sensor. Moreover, the lane keeping and changing behaviors are extracted from the lane detection function, and further reduce the lateral positioning error in the proposed localization system. We evaluate the integrated localization system in the challenging city urban scenario. The experiments demonstrate the proposed method has sub-meter accuracy with respect to mean positioning error.

  5. Starting a local conservation and passive solar retrofit program: an energy planning sourcebook

    SciTech Connect

    Barber, V; Mathews, R

    1982-02-01

    A city planner or a neighborhood activist may wish to initiate a local conservation and passive solar retrofit program but may not have previous experience in doing so. This sourcebook is designed to assist interested individuals with their energy planning efforts, from determining retrofit potential, to financing and implementing the program. An approach or methodology is provided which can be applied to determine retrofit potential in single-family residences, mobile homes, multifamily residences, and nonresidential buildings. Case studies in Albuquerque, New Mexico, are given as examples. Guidelines are provided for evaluating the economic benefits of a retrofit program through benefit-cost analysis and economic base studies at the city and neighborhood levels. Also included are approaches to community outreach, detailing how to get started, how to gain local support, and examples of successful programs throughout the US. The need for financing, the development of a local strategy, public and private financing techniques, and community energy service organizations are examined. In addition to the Albuquerque case studies, a brief technology characterization, heat-loss calculations, economic tools, and a list of resources are appended.

  6. Automatic post processing algorithm for passive seismic monitoring data

    NASA Astrophysics Data System (ADS)

    Nepeina, K.

    2014-05-01

    The problem of monitoring of different types of seismic events - geoacoustic precursors of earthquakes, industrial and field explosions, places fragments fall of separating parts of rockets-carriers, etc. is one of the key in the modern ecology of the environment. The peculiarity of this kind of monitoring is that it is mobile seismic groups, which should be based in the proposed area of occurrence of events. One of the most important steps for solving the problems connected with the detection and identification of recorded data from passive sensors in mobile seismic array (MSA). The task of determining the nature of the source and its' coordinates lies in the basis of direction, referred to as the geoacoustic location. Using a new approach (not by location but by neural classification of waveform "portraits") usability of algorithm which based on quantitative parameters of signal will be demonstrated.

  7. Passivation Behavior of Ultrafine-Grained Pure Copper Fabricated by Accumulative Roll Bonding (ARB) Process

    NASA Astrophysics Data System (ADS)

    Fattah-alhosseini, Arash; Imantalab, Omid

    2016-01-01

    In this study, passivation behavior of ultrafine-grained (UFG) pure copper fabricated by ARB process in 0.01 M borax solution has been investigated. Before any electrochemical measurements, evaluation of microstructure was obtained by transmission electron microscopy (TEM). TEM observations revealed that with increasing the number of ARB passes, the grain size of specimens decrease. Also, TEM images showed that UFGs with average size of below 100 nm appeared after 7 passes of ARB. To investigate the passivation behavior of the specimens, electrochemical impedance spectroscopy (EIS) and Mott-Schottky analysis was carried out. For this purpose, three potentials within the passive region were chosen for potentiostatic passive film growth. EIS results showed that both passive film and charge-transfer resistance increases with increasing the number of ARB passes. Moreover, Mott-Schottky analysis revealed that with increasing the number of ARB passes, the acceptor density of the passive films decreased. In conclusion, increasing the number of ARB passes offers better conditions for forming the passive films with higher protection behavior, due to the growth of a much thicker and less defective films.

  8. Industry-Grade Seismic Processing System for Controlled- (and Passive-) Source Research in Seismology

    NASA Astrophysics Data System (ADS)

    Chubak, G.; Morozov, I.

    2004-05-01

    to be initiated and controlled from a single interface. Jobs may be executed either locally or on a single or multiple remote systems in a heterogeneous computing environment. The GUI includes tools for run-time control of both local and remote processes.. The GUI also includes provisions for cluster scheduling, allowing processes to be executed on Beowulf clusters. Depending on their design, individual tools or flows can be parallelized using either PVM or MPI (Message Passing Interface). With the decentralized processing concept implemented in SIA, grid computing and seamless data exchange could become a reality without any effort from the users. In passive-source work, which is quickly adopting reflection processing techniques, this industry-style processing could provide sophisticated, inexpensive, and high performance approaches to data retrieval and access to hundreds of signal enhancement tools developed in reflection seismics.

  9. Combining Radiography and Passive Measurements for Radiological Threat Localization in Cargo

    SciTech Connect

    Miller, Erin A.; White, Timothy A.; Jarman, Kenneth D.; Kouzes, Richard T.; Kulisek, Jonathan A.; Robinson, Sean M.; Wittman, Richard A.

    2015-10-01

    Detecting shielded special nuclear material (SNM) in a cargo container is a difficult problem, since shielding reduces the amount of radiation escaping the container. Radiography provides information that is complementary to that provided by passive gamma-ray detection systems: while not directly sensitive to radiological materials, radiography can reveal highly shielded regions that may mask a passive radiological signal. Combining these measurements has the potential to improve SNM detection, either through improved sensitivity or by providing a solution to the inverse problem to estimate source properties (strength and location). We present a data-fusion method that uses a radiograph to provide an estimate of the radiation-transport environment for gamma rays from potential sources. This approach makes quantitative use of radiographic images without relying on image interpretation, and results in a probabilistic description of likely source locations and strengths. We present results for this method for a modeled test case of a cargo container passing through a plastic-scintillator-based radiation portal monitor and a transmission-radiography system. We find that a radiograph-based inversion scheme allows for localization of a low-noise source placed randomly within the test container to within 40 cm, compared to 70 cm for triangulation alone, while strength estimation accuracy is improved by a factor of six. Improvements are seen in regions of both high and low shielding, but are most pronounced in highly shielded regions. The approach proposed here combines transmission and emission data in a manner that has not been explored in the cargo-screening literature, advancing the ability to accurately describe a hidden source based on currently-available instrumentation.

  10. Passive and active processes in visuo-spatial memory: double dissociation in developmental learning disabilities.

    PubMed

    Cornoldi, C; Rigoni, F; Venneri, A; Vecchi, T

    2000-01-01

    The distinction between passive and active visuo-spatial memory has been useful to interpret various pattern of deficits reported in individual differences studies. However, this interpretation raises the issue of task difficulty, since active tasks could be failed simply because more complex and the corresponding deficit could reflect a reduced capacity of the system. We describe two children with Nonverbal Learning Disability whose performance provides evidence of a dissociation between passive and active memory processes. One of the children showed a selective impairment in passive tasks and performed flawlessly in active tasks, whereas the second child displayed the opposite pattern. These data suggest that a qualitative difference between passive and active processes does exist and that differences in performance do not reflect a lower/higher level of task difficulty. Further, these data underlie the importance of formulating theoretical models of visuo-spatial memory including both material-related (i.e., visual vs spatial) and process-related (i.e., passive vs active) distinctions.

  11. Systematic satellite observations of the impact of aerosols from passive volcanic degassing on local cloud properties

    NASA Astrophysics Data System (ADS)

    Ebmeier, S. K.; Sayer, A. M.; Grainger, R. G.; Mather, T. A.; Carboni, E.

    2014-01-01

    The impact of volcanic emissions is a significant source of uncertainty in estimations of aerosol indirect radiative forcing, especially with respect to emissions from passive degassing and minor explosions. Understanding the impact of volcanic emissions on indirect radiative forcing is important for assessing present day atmospheric properties and also to define the pre-industrial baseline to assess anthropogenic perturbations. We present observations of the time-averaged indirect aerosol effect within 200 km downwind of isolated island volcanoes in regions of low present-day aerosol burden using MODIS and AATSR data. Retrievals of aerosol and cloud properties at Kīlauea (Hawai'i), Yasur (Vanuatu) and Piton de la Fournaise (Réunion) are rotated about the volcanic vent according to wind direction, so that retrievals downwind of the volcano can be averaged to improve signal to noise ratio. The emissions from all three volcanoes, including those from passive degassing, strombolian activity and minor explosions lead to measurably increased aerosol optical depth downwind of the active vent. Average cloud droplet effective radius is lower downwind of the volcano in all cases, with the peak difference in effective radius of 4-8 μm at the different volcanoes. A comparison of these observations with cloud properties at isolated islands with no significant source of aerosol suggests that these patterns are not purely orographic in origin. This approach sets out a first step for the systematic measurement of the effects of present day low altitude volcanic emissions on cloud properties. Our observations of unpolluted, isolated marine settings may also capture processes similar to those in the pre-industrial marine atmosphere.

  12. Systematic Satellite Observations of the Impact of Aerosols from Passive Volcanic Degassing on Local Cloud Properties

    NASA Technical Reports Server (NTRS)

    Ebmeier, S. K.; Sayer, A. M.; Grainger, R. G.; Mather, T. A.; Carboni, E.

    2014-01-01

    The impact of volcanic emissions is a significant source of uncertainty in estimations of aerosol indirect radiative forcing, especially with respect to emissions from passive de-gassing and minor explosions. Understanding the impact of volcanic emissions on indirect radiative forcing is important assessing present day atmospheric properties and also to define the pre-industrial baseline to assess anthropogenic perturbations. We present observations of the time-averaged indirect aerosol effect within 200 km downwind of isolated island volcanoes in regions of low present-day aerosol burden using MODIS and AATSR data. Retrievals of aerosol and cloud properties at Kilauea (Hawaii), Yasur (Vanuatu) and Piton de la Fournaise (Reunion) are rotated about the volcanic vent according to wind direction, so that retrievals downwind of the volcano can be averaged to improve signal to noise ratio. The emissions from all three volcanoes, including those from passive degassing, strombolian activity and minor explosions lead to measurably increased aerosol optical depth downwind of the active vent. Average cloud droplet effective radius is lower downwind of the volcano in all cases, with the peak difference in effective radius ranging from 48 microns at the different volcanoes. A comparison of these observations with cloud properties at isolated islands with no significant source of aerosol suggests that these patterns are not purely orographic in origin. This approach sets out a first step for the systematic measurement of the effects of present day low altitude volcanic emissions on cloud properties, and our observations of unpolluted, isolated marine settings may capture processes similar to those in the preindustrial marine atmosphere.

  13. Three-dimensional velocity structure of the Galeras volcano (Colombia) from passive local earthquake tomography

    NASA Astrophysics Data System (ADS)

    Vargas, Carlos Alberto; Torres, Roberto

    2015-08-01

    A three-dimensional estimation of the Vp, Vs and Vp/Vs ratio structure at Galeras volcano was conducted by means of passive local earthquake tomography. 14,150 volcano-tectonic events recorded by 58 stations in the seismological network established for monitoring the volcanic activity by the Colombian Geological Survey - Pasto Volcano Observatory between the years 1989 and 2015, were inverted by using the LOTOS code. The seismic events are associated with shear-stress fractures in solid rock as a response to pressure induced by magma flow. Tomography resolution tests suggest a depth of imaging that yield 10 km from the summit of the main crater, illuminating a large portion of the volcanic structure and the interaction of tectonic features like the Buesaco and Silvia-Pijao faults. Full catalog tomographic inversion, that represents the stacked image of the volcanic structure or the most permanent features underneath the volcano, shows vertical structures aligned with seismicity beneath the main crater. We hypothesize that these structures correspond to a system of ducts or fractures through which magma and fluid phases flow up from deeper levels toward the top and related with the intersection of the surface traces of the Silvia-Pijao and Buesaco faults.

  14. An analytic overview of long range passive detection and localization in an inhomogeneous ocean

    SciTech Connect

    Middleton, D

    1991-07-01

    An analytic summary or overview of the problem of long range passive source detection and localization is presented. The principal aims are to provide an analytic basis for developing effective weak-signal detection and estimation algorithms and performance measures in a model-based approach, when the desired source (or sources) are not surely known to be present p(H{sub 1})<1, in a general ambient noise field due primarily to surface or near-surface noise mechanisms. In addition to threshold detection and estimation (when (pH{sub 1})<1: signal not surely present) with correlated space and time noise samples, procedures for modeling the random acoustic noise and signal fields are outlined, from the viewpoint of the ocean as an inhomogeneous acoustic waveguide, {nabla}c{ne}0, with boundaries, and arbitrary (near) surface distributions of noise sources. The latter are required to specify these otherwise canonical results to the present class of problems. The Report concludes with a short list of next steps, and references to pertinent supporting material.

  15. Passive monitoring and localization of marine mammals in open ocean environments using widely spaced bottom mounted hydrophones

    NASA Astrophysics Data System (ADS)

    Jarvis, Susan; Moretti, David; Morrissey, Ronald; Dimarzio, Nancy

    2003-10-01

    The Marine Mammal Monitoring on Navy Ranges (M3R) project has developed a toolset for passive detection and localization of marine mammals using the existing infrastructure of Navy's undersea ranges. The Office of Naval Research funded the M3R project as part of the Navy's effort to determine the effects of acoustic and other emissions on marine mammals and threatened/endangered species. A necessary first step in this effort is the creation of a baseline of behavior, which requires long-term monitoring of marine mammals. Such monitoring, in turn, requires the ability to detect and localize the animals. This paper will present the passive acoustic monitoring and localization tools developed under M3R. It will also present results of the deployment of the M3R tools at the Atlantic Undersea Test and Evaluation Center (AUTEC), Andros Island, Bahamas from June through November 2003. Finally, it will discuss current work to improve automated species classification.

  16. Methodology for the passive control of orbital inclination and mean local time to meet sun-synchronous orbit requirements

    NASA Technical Reports Server (NTRS)

    Folta, David; Kraft, Lauri

    1992-01-01

    The mean local time (MLT) of equatorial crossing of a sun-synchronous Earth-observing spacecraft orbit drifts with inclination; therefore, in order to maintain the MLT, the inclination must be controlled. Inclination may be maintained actively by costly out-of-plane maneuvers or passively by using the perturbing forces due to the sun and moon. This paper examines the passive control approach using the Earth Observing System (EOS) as a basis for the discussion. Applications to Landsat and National Oceanic and Atmospheric Administration (NOAA) spacecraft are presented for comparison. This technique is especially beneficial to spacecraft lacking propulsion systems. The results indicate that passive inclination control appears to be the preferable maintenance method when spacecraft weight restrictions, operational considerations, and scientific requirements apply.

  17. DEMONSTRATION OF AN INTEGRATED, PASSIVE BIOLOGICAL TREATMENT PROCESS FOR AMD

    EPA Science Inventory

    An innovative, cost-effective, biological treatment process has been designed by MSE Technology Applications, Inc. to treat acid mine drainage (AMD). A pilot-scale demonstration is being conducted under the Mine Waste Technology Program using water flowing from an abandoned mine ...

  18. Adaptive behaviors in multi-agent source localization using passive sensing

    PubMed Central

    Shaukat, Mansoor; Chitre, Mandar

    2016-01-01

    In this paper, the role of adaptive group cohesion in a cooperative multi-agent source localization problem is investigated. A distributed source localization algorithm is presented for a homogeneous team of simple agents. An agent uses a single sensor to sense the gradient and two sensors to sense its neighbors. The algorithm is a set of individualistic and social behaviors where the individualistic behavior is as simple as an agent keeping its previous heading and is not self-sufficient in localizing the source. Source localization is achieved as an emergent property through agent’s adaptive interactions with the neighbors and the environment. Given a single agent is incapable of localizing the source, maintaining team connectivity at all times is crucial. Two simple temporal sampling behaviors, intensity-based-adaptation and connectivity-based-adaptation, ensure an efficient localization strategy with minimal agent breakaways. The agent behaviors are simultaneously optimized using a two phase evolutionary optimization process. The optimized behaviors are estimated with analytical models and the resulting collective behavior is validated against the agent’s sensor and actuator noise, strong multi-path interference due to environment variability, initialization distance sensitivity and loss of source signal. PMID:28018121

  19. Adaptive behaviors in multi-agent source localization using passive sensing.

    PubMed

    Shaukat, Mansoor; Chitre, Mandar

    2016-12-01

    In this paper, the role of adaptive group cohesion in a cooperative multi-agent source localization problem is investigated. A distributed source localization algorithm is presented for a homogeneous team of simple agents. An agent uses a single sensor to sense the gradient and two sensors to sense its neighbors. The algorithm is a set of individualistic and social behaviors where the individualistic behavior is as simple as an agent keeping its previous heading and is not self-sufficient in localizing the source. Source localization is achieved as an emergent property through agent's adaptive interactions with the neighbors and the environment. Given a single agent is incapable of localizing the source, maintaining team connectivity at all times is crucial. Two simple temporal sampling behaviors, intensity-based-adaptation and connectivity-based-adaptation, ensure an efficient localization strategy with minimal agent breakaways. The agent behaviors are simultaneously optimized using a two phase evolutionary optimization process. The optimized behaviors are estimated with analytical models and the resulting collective behavior is validated against the agent's sensor and actuator noise, strong multi-path interference due to environment variability, initialization distance sensitivity and loss of source signal.

  20. The Effect of Processing Instruction and Dictogloss Tasks on Acquisition of the English Passive Voice

    ERIC Educational Resources Information Center

    Qin, Jingjing

    2008-01-01

    This study was intended to compare processing instruction (VanPatten, 1993, 1996, 2000), an input-based focus on form technique, to dictogloss tasks, an output-oriented focus-on-form type of instruction to assess their effects in helping beginning-EFL (English as a Foreign Language) learners acquire the simple English passive voice. Two intact…

  1. Semantic Processing Persists despite Anomalous Syntactic Category: ERP Evidence from Chinese Passive Sentences

    PubMed Central

    Yang, Yang; Wu, Fuyun; Zhou, Xiaolin

    2015-01-01

    The syntax-first model and the parallel/interactive models make different predictions regarding whether syntactic category processing has a temporal and functional primacy over semantic processing. To further resolve this issue, an event-related potential experiment was conducted on 24 Chinese speakers reading Chinese passive sentences with the passive marker BEI (NP1 + BEI + NP2 + Verb). This construction was selected because it is the most-commonly used Chinese passive and very much resembles German passives, upon which the syntax-first hypothesis was primarily based. We manipulated semantic consistency (consistent vs. inconsistent) and syntactic category (noun vs. verb) of the critical verb, yielding four conditions: CORRECT (correct sentences), SEMANTIC (semantic anomaly), SYNTACTIC (syntactic category anomaly), and COMBINED (combined anomalies). Results showed both N400 and P600 effects for sentences with semantic anomaly, with syntactic category anomaly, or with combined anomalies. Converging with recent findings of Chinese ERP studies on various constructions, our study provides further evidence that syntactic category processing does not precede semantic processing in reading Chinese. PMID:26125621

  2. Improved traveling-wave efficiency in 7T human MRI using passive local loop and dipole arrays.

    PubMed

    Yan, Xinqiang; Zhang, Xiaoliang; Gore, John C; Grissom, William A

    2017-02-09

    Traveling-wave MRI, which uses relatively small and simple RF antennae, has robust matching performance and capability for large field-of-view (FOV) imaging. However, the power efficiency of traveling-wave MRI is much lower than conventional methods, which limits its application. One simple approach to improve the power efficiency is to place passive resonators around the subject being imaged. The feasibility of this approach has been demonstrated in previous works using a single small resonant loop. In this work, we aim to explore how much the improvements can be maintained in human imaging using an array design, and whether electric dipoles can be used as local elements. First, a series of electromagnetic (EM) simulations were performed on a human model. Then RF coils were constructed and the simulation results using the best setup for head imaging were validated in MR experiments. By using the passive local loop and transverse dipole arrays, respectively, the transmit efficiency (B1(+)) of traveling-wave MRI can be improved by 3-fold in the brain and 2-fold in the knee. The types of passive elements (loops or dipoles) should be carefully chosen for brain or knee imaging to maximize the improvement, and the enhancement depends on the local body configuration.

  3. Recombination at laser-processed local base contacts by dynamic infrared lifetime mapping

    NASA Astrophysics Data System (ADS)

    Müller, Jens; Bothe, Karsten; Gatz, Sebastian; Haase, Felix; Mader, Christoph; Brendel, Rolf

    2010-12-01

    Laser-processed local metal contacts to Si solar cells are a promising approach, to combine high efficiency and low production cost. Understanding carrier transport and recombination in locally contacted solar cells requires numerical simulations with experimentally verified input parameters. One of these input parameters is the reverse saturation current density J0,cont at the local base contact. We determine J0,cont by means of area averaged charge carrier lifetime measurements and an analytical model, which distinguishes between recombination at the metal contacts and at the passivated interface in between the contacts. The calibration-free dynamic infrared lifetime mapping technique is used. We measure local reverse saturation current densities J0,cont=2×103 to 2×107 fA/cm2 at metal contacts to p-type float-zone material with resistivities ρ =0.5 to 200 Ω cm. Laser contact openings (LCOs) formed by laser ablation of an amorphous Si/SiNx passivation stack and subsequent physical vapor deposition of aluminum are used as contact formation technique. As well laser fired contacts (LFCs) are applied to the same passivation stack and metallization. We observe no difference in J0,cont between LCO and LFC. Our results indicate degradation of the passivation stack by the laser treatment in the vicinity of the LCO and LFC.

  4. Local and Regional Processes in Community Assembly

    PubMed Central

    Márquez, Juan C; Kolasa, Jurek

    2013-01-01

    Controversy on whether local (deterministic) or regional (stochastic) factors control the structure of communities persists after decades of research. The main reason for why it has not been resolved may lie in the nature of evidence which largely comes from realized natural communities. In such communities assembly history leaves a mark that may support either set of factors. To avoid the confounding effects of assembly history we controlled for these effects experimentally. We created a null community by mixing 17 rock pool communities. We then divided the null community into replicates and distributed among treatments representing a gradient of factors from local to regional. We hypothesized that if deterministic factors dominate the assembly of communities, community structures should show a corresponding gradient from being very similar and convergent to dissimilar and divergent. In contrast, if local processes are predominantly stochastic in nature, such a gradient of community configurations should emerge even in the homogeneous setting. Our results appear to partially support both hypotheses and thus suggest that both deterministic and stochastic processes contribute to the assembly of communities. Furthermore, we found that to satisfactorily explain patterns observed in natural communities environmental heterogeneity and regional processes must also be considered. In conclusion, although deterministic mechanisms seem to be important in the assembly of communities, in natural systems their signal may be diluted and masked whenever other factors exert meaningful influence. Such factors increase the number of possible paths to the point that the number of paths equals the number of communities in a metacommunity. PMID:23355879

  5. Anisotropic Elastography for Local Passive Properties and Active Contractility of Myocardium from Dynamic Heart Imaging Sequence

    PubMed Central

    Wang, Ge; Sun, L. Z.

    2006-01-01

    Major heart diseases such as ischemia and hypertrophic myocardiopathy are accompanied with significant changes in the passive mechanical properties and active contractility of myocardium. Identification of these changes helps diagnose heart diseases, monitor therapy, and design surgery. A dynamic cardiac elastography (DCE) framework is developed to assess the anisotropic viscoelastic passive properties and active contractility of myocardial tissues, based on the chamber pressure and dynamic displacement measured with cardiac imaging techniques. A dynamic adjoint method is derived to enhance the numerical efficiency and stability of DCE. Model-based simulations are conducted using a numerical left ventricle (LV) phantom with an ischemic region. The passive material parameters of normal and ischemic tissues are identified during LV rapid/reduced filling and artery contraction, and those of active contractility are quantified during isovolumetric contraction and rapid/reduced ejection. It is found that quasistatic simplification in the previous cardiac elastography studies may yield inaccurate material parameters. PMID:23165032

  6. Anisotropic elastography for local passive properties and active contractility of myocardium from dynamic heart imaging sequence.

    PubMed

    Liu, Yi; Wang, Ge; Sun, L Z

    2006-01-01

    Major heart diseases such as ischemia and hypertrophic myocardiopathy are accompanied with significant changes in the passive mechanical properties and active contractility of myocardium. Identification of these changes helps diagnose heart diseases, monitor therapy, and design surgery. A dynamic cardiac elastography (DCE) framework is developed to assess the anisotropic viscoelastic passive properties and active contractility of myocardial tissues, based on the chamber pressure and dynamic displacement measured with cardiac imaging techniques. A dynamic adjoint method is derived to enhance the numerical efficiency and stability of DCE. Model-based simulations are conducted using a numerical left ventricle (LV) phantom with an ischemic region. The passive material parameters of normal and ischemic tissues are identified during LV rapid/reduced filling and artery contraction, and those of active contractility are quantified during isovolumetric contraction and rapid/reduced ejection. It is found that quasistatic simplification in the previous cardiac elastography studies may yield inaccurate material parameters.

  7. Deploying Monitoring Trails for Fault Localization in All- Optical Networks and Radio-over-Fiber Passive Optical Networks

    NASA Astrophysics Data System (ADS)

    Maamoun, Khaled Mohamed

    Fault localization is the process of realizing the true source of a failure from a set of collected failure notifications. Isolating failure recovery within the network optical domain is necessary to resolve alarm storm problems. The introduction of the monitoring trail (m-trail) has been proven to deliver better performance by employing monitoring resources in a form of optical trails - a monitoring framework that generalizes all the previously reported counterparts. In this dissertation, the m-trail design is explored and a focus is given to the analysis on using m-trails with established lightpaths to achieve fault localization. This process saves network resources by reducing the number of the m-trails required for fault localization and therefore the number of wavelengths used in the network. A novel approach based on Geographic Midpoint Technique, an adapted version of the Chinese Postman's Problem (CPP) solution and an adapted version of the Traveling Salesman's Problem (TSP) solution algorithms is introduced. The desirable features of network architectures and the enabling of innovative technologies for delivering future millimeter-waveband (mm-WB) Radio-over-Fiber (RoF) systems for wireless services integrated in a Dense Wavelength Division Multiplexing (DWDM) is proposed in this dissertation. For the conceptual illustration, a DWDM RoF system with channel spacing of 12.5 GHz is considered. The mm-WB Radio Frequency (RF) signal is obtained at each Optical Network Unit (ONU) by simultaneously using optical heterodyning photo detection between two optical carriers. The generated RF modulated signal has a frequency of 12.5 GHz. This RoF system is easy, cost-effective, resistant to laser phase noise and also reduces maintenance needs, in principle. A revision of related RoF network proposals and experiments is also included. A number of models for Passive Optical Networks (PON)/ RoF-PON that combine both innovative and existing ideas along with a number of

  8. Fifth International Workshop on Detection, Classification, Localization and Density Estimation of Marine Mammals using Passive Acoustics

    DTIC Science & Technology

    2013-09-30

    spring 2011 in Seattle) • The Fourth International Conference on Detection and Classification of Marine Mammals using Passive Acoustics ( Pavia ...Italy, 2009) • The International BioAcoustic Congress ( Pavia , Italy, 2009) Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting

  9. Lexically Specific Knowledge and Individual Differences in Adult Native Speakers' Processing of the English Passive

    ERIC Educational Resources Information Center

    Street, James A.; Dabrowska, Ewa

    2014-01-01

    This article provides experimental evidence for the role of lexically specific representations in the processing of passive sentences and considerable education-related differences in comprehension of the passive construction. The experiment measured response time and decision accuracy of participants with high and low academic attainment using an…

  10. Advanced information processing system: Local system services

    NASA Technical Reports Server (NTRS)

    Burkhardt, Laura; Alger, Linda; Whittredge, Roy; Stasiowski, Peter

    1989-01-01

    The Advanced Information Processing System (AIPS) is a multi-computer architecture composed of hardware and software building blocks that can be configured to meet a broad range of application requirements. The hardware building blocks are fault-tolerant, general-purpose computers, fault-and damage-tolerant networks (both computer and input/output), and interfaces between the networks and the computers. The software building blocks are the major software functions: local system services, input/output, system services, inter-computer system services, and the system manager. The foundation of the local system services is an operating system with the functions required for a traditional real-time multi-tasking computer, such as task scheduling, inter-task communication, memory management, interrupt handling, and time maintenance. Resting on this foundation are the redundancy management functions necessary in a redundant computer and the status reporting functions required for an operator interface. The functional requirements, functional design and detailed specifications for all the local system services are documented.

  11. A new application of passive samplers as indicators of in-situ biodegradation processes.

    PubMed

    Belles, Angel; Alary, Claire; Criquet, Justine; Billon, Gabriel

    2016-12-01

    In this paper, a method for evaluating the in-situ degradation of nitro polycyclic aromatic hydrocarbons (nitro-PAH) in sediments is presented. The methodology is adapted from the passive sampler technique, which commonly uses the dissipation rate of labeled compounds loaded in passive sampler devices to sense the environmental conditions of exposure. In the present study, polymeric passive samplers (made of polyethylene strips) loaded with a set of labeled polycyclic aromatic hydrocarbons (PAH) and nitro-PAH were immersed in sediments (in field and laboratory conditions) to track the degradation processes. This approach is theoretically based on the fact that a degradation process induces a steeper concentration gradient of the labeled compounds in the surrounding sediment, thereby increasing their compound dissipation rates compared with their dissipation in abiotic conditions. Postulating that the degradation magnitude is the same for the labeled compounds loaded in polyethylene strips and for their native homologs that are potentially present in the sediment, the field degradation of 3 nitro-PAH (2-nitro-fluorene, 1-nitro-pyrene, 6-nitro-chrysene) was semi-quantitatively analyzed using the developed method.

  12. Application of a passive electrochemical noise technique to localized corrosion of candidate radioactive waste container materials

    SciTech Connect

    Korzan, M.A.

    1994-05-01

    One of the key engineered barriers in the design of the proposed Yucca Mountain repository is the waste canister that encapsulates the spent fuel elements. Current candidate metals for the canisters to be emplaced at Yucca Mountain include cast iron, carbon steel, Incoloy 825 and titanium code-12. This project was designed to evaluate passive electrochemical noise techniques for measuring pitting and corrosion characteristics of candidate materials under prototypical repository conditions. Experimental techniques were also developed and optimized for measurements in a radiation environment. These techniques provide a new method for understanding material response to environmental effects (i.e., gamma radiation, temperature, solution chemistry) through the measurement of electrochemical noise generated during the corrosion of the metal surface. In addition, because of the passive nature of the measurement the technique could offer a means of in-situ monitoring of barrier performance.

  13. Sound Localization with Communications Headsets: Comparison of Passive and Active Systems

    DTIC Science & Technology

    2007-12-01

    communications muffs in active noise reduction (ANR) and talk-through-circuitry (TTC) modes and Nacre QUIETPRO communications earplugs in off (passive...UK) in active noise reduction (ANR) and talk-through circuitry (TTC) modes ofoperation and Nacre QU’IETPRO communications earplugs ( Nacre , Trondheim...externally mounted microphones [Figure 2a]. Sound level is limited to 85 dBA. The Nacre QUIETPRO device comprises two ear pieces (transducer housing

  14. Electrochemical and Passive Behaviors of Pure Copper Fabricated by Accumulative Roll-Bonding (ARB) Process

    NASA Astrophysics Data System (ADS)

    Imantalab, O.; Fattah-alhosseini, A.

    2015-07-01

    In the present work, electrochemical and passive behaviors of pure copper fabricated by accumulative roll-bonding (ARB) process in 0.01 M borax solution (pH = 9.1) have been studied. Before any electrochemical measurements, evaluation of microstructure was obtained by Vickers microhardness, x-ray diffraction (XRD), and transmission electron microscopy. The results of microhardness tests revealed that microhardness values increased with the increasing number of ARB cycles. Also a sharp increase was seen in microhardness after the first ARB cycle, whereas mediocre additional increases were observed afterward up to the seven cycles. Moreover, XRD patterns showed that the mean crystallite size values decrease with the increasing number of ARB cycles. To investigate the electrochemical and passive behaviors of the samples, the potentiodynamic polarization, Mott-Schottky analysis and electrochemical impedance spectroscopy (EIS) were carried out. Polarization plots revealed that as a result of ARB, the corrosion behavior of the specimens improves compared with the annealed pure copper. Also, the Mott-Schottky analysis and EIS measurements showed that the increasing number of ARB cycles offer better conditions for forming the passive films with higher protection behavior, due to the growth of less-defective films.

  15. Real-time image processing for passive mmW imagery

    NASA Astrophysics Data System (ADS)

    Kozacik, Stephen; Paolini, Aaron; Bonnett, James; Harrity, Charles; Mackrides, Daniel; Dillon, Thomas E.; Martin, Richard D.; Schuetz, Christopher A.; Kelmelis, Eric; Prather, Dennis W.

    2015-05-01

    The transmission characteristics of millimeter waves (mmWs) make them suitable for many applications in defense and security, from airport preflight scanning to penetrating degraded visual environments such as brownout or heavy fog. While the cold sky provides sufficient illumination for these images to be taken passively in outdoor scenarios, this utility comes at a cost; the diffraction limit of the longer wavelengths involved leads to lower resolution imagery compared to the visible or IR regimes, and the low power levels inherent to passive imagery allow the data to be more easily degraded by noise. Recent techniques leveraging optical upconversion have shown significant promise, but are still subject to fundamental limits in resolution and signal-to-noise ratio. To address these issues we have applied techniques developed for visible and IR imagery to decrease noise and increase resolution in mmW imagery. We have developed these techniques into fieldable software, making use of GPU platforms for real-time operation of computationally complex image processing algorithms. We present data from a passive, 77 GHz, distributed aperture, video-rate imaging platform captured during field tests at full video rate. These videos demonstrate the increase in situational awareness that can be gained through applying computational techniques in real-time without needing changes in detection hardware.

  16. Passive acoustic localization of the Atlantic bottlenose dolphin using whistles and echolocation clicks.

    PubMed

    Freitag, L E; Tyack, P L

    1993-04-01

    A method for localization and tracking of calling marine mammals was tested under realistic field conditions that include noise, multipath, and arbitrarily located sensors. Experiments were performed in two locations using four and six hydrophones with captive Atlantic bottlenose dolphins (Tursiops truncatus). Acoustic signals from the animals were collected in the field using a digital acoustic data acquisition system. The data were then processed off-line to determine relative hydrophone positions and the animal locations. Accurate hydrophone position estimates are achieved by pinging sequentially from each hydrophone to all the others. A two-step least-squares algorithm is then used to determine sensor locations from the calibration data. Animal locations are determined by estimating the time differences of arrival of the dolphin signals at the different sensors. The peak of a matched filter output or the first cycle of the observed waveform is used to determine arrival time of an echolocation click. Cross correlation between hydrophones is used to determine inter-sensor time delays of whistles. Calculation of source location using the time difference of arrival measurements is done using a least-squares solution to minimize error. These preliminary experimental results based on a small set of data show that realistic trajectories for moving animals may be generated from consecutive location estimates.

  17. Process Dependence of H Passivation and Doping in H-implanted ZnO

    DTIC Science & Technology

    2013-01-04

    full text article. 2013 J. Phys. D: Appl. Phys. 46 055107 (http://iopscience.iop.org/0022- 3727 /46/5/055107) Download details: IP Address: 131.84.11.215...MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10 . SPONSOR/MONITOR’S ACRONYM(S) 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION/AVAILABILITY...Appl. Phys. 46 (2013) 055107 (7pp) doi:10.1088/0022- 3727 /46/5/055107 Process dependence of H passivation and doping in H-implanted ZnO Z Zhang1, D C

  18. Comparing passive source localization and tracking approaches with a towed horizontal receiver array in an ocean waveguide.

    PubMed

    Gong, Zheng; Tran, Duong D; Ratilal, Purnima

    2013-11-01

    Approaches for instantaneous passive source localization using a towed horizontal receiver array in a random range-dependent ocean waveguide are examined. They include: (1) Moving array triangulation, (2) array invariant, (3) bearings-only target motion analysis in modified polar coordinates via the extended Kalman filter, and (4) bearings-migration minimum mean-square error. These methods are applied to localize and track a vertical source array deployed in the far-field of a towed horizontal receiver array during the Gulf of Maine 2006 Experiment. The source transmitted intermittent broadband pulses in the 300 to 1200 Hz frequency range. A nonlinear matched-filter kernel designed to replicate the acoustic signal measured by the receiver array is applied to enhance the signal-to-noise ratio. The source localization accuracy is found to be highly dependent on source-receiver geometry and the localization approach. For a relatively stationary source drifting at speeds much slower than the receiver array tow-speed, the mean source position can be estimated by moving array triangulation with less than 3% error near broadside direction. For a moving source, the Kalman filter method gives the best performance with 5.5% error. The array invariant is the best approach for localizing sources within the endfire beam of the receiver array with 7% error.

  19. Array Signal Processing for Source Localization and Digital Communication.

    NASA Astrophysics Data System (ADS)

    Song, Bong-Gee

    Array antennas are used in several areas such as sonar and digital communication. Although array patterns may be different depending on applications, they are used with a view to collecting more data and obtaining better results. We first consider a passive sonar system in random environments where the index of refraction is random. While source localization problems for deterministic environments are well studied, they require accurate propagation models which are not available in random environments. We extend the localization problems to random environments. It has been shown that methods developed for deterministic environments fail in random environments because of the stochastic nature of acoustic propagation. Therefore, we model observations as random, and use a statistical signal processing technique combined with physics. The statistical signal model is provided by physics either empirically or theoretically. The performance technique relies on the accuracy of the statistical models. We have applied the maximum likelihood method to angle of arrival estimation and range estimation problems. The Cramer-Rao lower bounds have been also derived to predict the estimation performance. Next, we use the array antennas for diversity combining equalization in digital communications. Spatial diversity equalization is used in two ways; to improve bit error rate or to improve the transmission rate. This is feasible by using more antennas at the receiver end. We apply Helstrom's saddle point integration method to multi -input multi-output communication systems and show that a factor of 3-4 of channel reuse is possible. It is also shown that the advantage is because of the diversity itself not because of more taps. We further improve the equalization performance by joint pre- and postfilter design. Two different methods have been proposed according to the prefilter type. Although the mean square error is not easy to minimize, appropriate methods have been adopted and show

  20. In situ evolution of trivalent chromium process passive film on Al in a corrosive aqueous environment.

    PubMed

    Dong, Xuecheng; Argekar, Sandip; Wang, Peng; Schaefer, Dale W

    2011-11-01

    In situ neutron reflectivity (NR) is used to observe the structure and evolution of a Trivalent Chromium Process (TCP) passive film on Al in a NaCl-D(2)O solution. Using a split liquid reflectivity cell we mimicked the corrosion process on the anodic sites in alloy AA 2024-T3 in a pitting scenario. The split cell separates the anodic and cathodic reactions, allowing NR observation of the corroding anodic surface under potential control. We observed the evolution of the TCP film on the Al anode and compared the degradation of the Al with and without TCP protection. When held at 100 mV above the open-circuit potential (OCP), unprotected aluminum dissolves at a rate of 120 Å/h. By contrast, TCP-coated Al is stable up to the pitting potential (200 mV above OCP). In the passive state D(2)O molecules penetrate the bulk TCP film by partially replacing the hydrate water. In spite of exchange of hydration water, the TCP film is stable and the underlying aluminum is fully protected. The passive character of the TCP film is due to a dense layer at the metal-TCP interface and/or to suppression of ion transport in the bulk film. As the pitting potential is approached the film swells and NaCl-D(2)O solution penetrates the TCP film. At this point, 50 vol % of the TCP film is occupied by bulk NaCl-D(2)O solution. Failure occurs by aluminum dissolution under the swollen TCP film as the imbibed solution contacts the Al metal. Further increase in potential leads to complete stripping of the TCP film.

  1. International Workshop on Detection, Classification and Localization of Marine Mammals Using Passive Acoustics (4th). International Workshop on Density Estimation of Marine Mammals Using Passive Acoustics (1st)

    DTIC Science & Technology

    2009-09-13

    Mars 55 Characterisation of sound subunits for humpback whale song analysis. F. Pace, P.R. White, O. Adam 56 Passive acoustic detection of Minke...International Monitoring System. Samaran Flore, Adam Olivier, Guinet Christophe 58 Detection of Minke whale sounds in the Stellwagen Bank National Marine...September 8.40 Characterisation of sound subunits for humpback whale song analysis. F. Pace, P.R. White, O. Adam 9.00 Passive acoustic detection of

  2. "Active" and "Passive" Lava Resurfacing Processes on Io: A Comparative Study of Loki Patera and Prometheus

    NASA Technical Reports Server (NTRS)

    Davies, A. G.; Matson, D. L.; Leone, G.; Wilson, L.; Keszthelyi, L. P.

    2004-01-01

    Studies of Galileo Near Infrared Mapping Spectrometer (NIMS) data and ground based data of volcanism at Prometheus and Loki Patera on Io reveal very different mechanisms of lava emplacement at these two volcanoes. Data analyses show that the periodic nature of Loki Patera s volcanism from 1990 to 2001 is strong evidence that Loki s resurfacing over this period resulted from the foundering of a crust on a lava lake. This process is designated passive , as there is no reliance on sub-surface processes: the foundering of the crust is inevitable. Prometheus, on the other hand, displays an episodicity in its activity which we designate active . Like Kilauea, a close analog, Prometheus s effusive volcanism is dominated by pulses of magma through the nearsurface plumbing system. Each system affords views of lava resurfacing processes through modelling.

  3. Morphotectonic evolution of passive margins undergoing active surface processes: large-scale experiments using numerical models.

    NASA Astrophysics Data System (ADS)

    Beucher, Romain; Huismans, Ritske S.

    2016-04-01

    Extension of the continental lithosphere can lead to the formation of a wide range of rifted margins styles with contrasting tectonic and geomorphological characteristics. It is now understood that many of these characteristics depend on the manner extension is distributed depending on (among others factors) rheology, structural inheritance, thermal structure and surface processes. The relative importance and the possible interactions of these controlling factors is still largely unknown. Here we investigate the feedbacks between tectonics and the transfers of material at the surface resulting from erosion, transport, and sedimentation. We use large-scale (1200 x 600 km) and high-resolution (~1km) numerical experiments coupling a 2D upper-mantle-scale thermo-mechanical model with a plan-form 2D surface processes model (SPM). We test the sensitivity of the coupled models to varying crust-lithosphere rheology and erosional efficiency ranging from no-erosion to very efficient erosion. We discuss how fast, when and how the topography of the continents evolves and how it can be compared to actual passive margins escarpment morphologies. We show that although tectonics is the main factor controlling the rift geometry, transfers of masses at the surface affect the timing of faulting and the initiation of sea-floor spreading. We discuss how such models may help to understand the evolution of high-elevated passive margins around the world.

  4. An Adaptive Likelihood Distribution Algorithm for the Localization of Passive RFID Tags

    NASA Astrophysics Data System (ADS)

    Ota, Yuuki; Hori, Toshihiro; Onishi, Taiki; Wada, Tomotaka; Mutsuura, Kouichi; Okada, Hiromi

    The RFID (Radio Frequency IDentification) tag technology is expected as a tool of localization. By the localization of RFID tags, a mobile robot which installs in RFID readers can recognize surrounding environments. In addition, RFID tags can be applied to a navigation system for walkers. In this paper, we propose an adaptive likelihood distribution scheme for the localization of RFID tags. This method adjusts the likelihood distribution depending on the signal intensity from RFID tags. We carry out the performance evaluation of estimated position error by both computer simulations and implemental experiments. We show that the proposed system is more effective than the conventional system.

  5. A Novel Communication Range Recognition (CRR) Scheme for Spatial Localization of Passive RFID Tags

    NASA Astrophysics Data System (ADS)

    Wada, Tomotaka; Uchitomi, Norie; Ota, Yuuki; Hori, Toshihiro; Mutsuura, Kouichi; Okada, Hiromi

    RFID (Radio Frequency Identification) technology is expected to be used as a localization tool. By the localization of RFID tags, a mobile robot equipped with an RFID reader can recognize the surrounding environment. In this paper, we propose a novel effective scheme called the communication range recognition (CRR) scheme for localizing RFID tags. In this scheme, an RFID reader determines the boundaries of the communication range when it is appropriately positioned by the robot. We evaluate the estimated position accuracy through numerous experiments. We show that the moving distance of the RFID reader in the proposed scheme is lower than that in conventional schemes.

  6. Amorphous Silicon Carbide Passivating Layers to Enable Higher Processing Temperature in Crystalline Silicon Heterojunction Solar Cells

    SciTech Connect

    Boccard, Mathieu; Holman, Zachary

    2015-04-06

    "Very efficient crystalline silicon (c-Si) solar cells have been demonstrated when thin layers of intrinsic and doped hydrogenated amorphous silicon (a-Si:H) are used for passivation and carrier selectivity in a heterojunction device. One limitation of this device structure is the (parasitic) absorption in the front passivation/collection a-Si:H layers; another is the degradation of the a-Si:H-based passivation upon temperature, limiting the post-processes to approximately 200°C thus restricting the contacting possibilities and potential tandem device fabrication. To alleviate these two limitations, we explore the potential of amorphous silicon carbide (a-SiC:H), a widely studied material in use in standard a-Si:H thin-film solar cells, which is known for its wider bandgap, increased hydrogen content and stronger hydrogen bonding compared to a-Si:H. We study the surface passivation of solar-grade textured n-type c-Si wafers for symmetrical stacks of 10-nm-thick intrinsic a-SiC:H with various carbon content followed by either p-doped or n-doped a-Si:H (referred to as i/p or i/n stacks). For both doping types, passivation (assessed through carrier lifetime measurements) is degraded by increasing the carbon content in the intrinsic a-SiC:H layer. Yet, this hierarchy is reversed after annealing at 350°C or more due to drastic passivation improvements upon annealing when an a-SiC:H layer is used. After annealing at 350°C, lifetimes of 0.4 ms and 2.0 ms are reported for i/p and i/n stacks, respectively, when using an intrinsic a-SiC:H layer with approximately 10% of carbon (initial lifetimes of 0.3 ms and 0.1 ms, respectively, corresponding to a 30% and 20-fold increase, respectively). For stacks of pure a-Si:H material the lifetimes degrade from 1.2 ms and 2.0 ms for i/p and i/n stacks, respectively, to less than 0.1 ms and 1.1 ms (12-fold and 2-fold decrease, respectively). For complete solar cells using pure a-Si:H i/p and i/n stacks, the open-circuit voltage (Voc

  7. Comprehensive analytical model for locally contacted rear surface passivated solar cells

    NASA Astrophysics Data System (ADS)

    Wolf, Andreas; Biro, Daniel; Nekarda, Jan; Stumpp, Stefan; Kimmerle, Achim; Mack, Sebastian; Preu, Ralf

    2010-12-01

    For optimum performance of solar cells featuring a locally contacted rear surface, the metallization fraction as well as the size and distribution of the local contacts are crucial, since Ohmic and recombination losses have to be balanced. In this work we present a set of equations which enable to calculate this trade off without the need of numerical simulations. Our model combines established analytical and empirical equations to predict the energy conversion efficiency of a locally contacted device. For experimental verification, we fabricate devices from float zone silicon wafers of different resistivity using the laser fired contact technology for forming the local rear contacts. The detailed characterization of test structures enables the determination of important physical parameters, such as the surface recombination velocity at the contacted area and the spreading resistance of the contacts. Our analytical model reproduces the experimental results very well and correctly predicts the optimum contact spacing without the use of free fitting parameters. We use our model to estimate the optimum bulk resistivity for locally contacted devices fabricated from conventional Czochralski-grown silicon material. These calculations use literature values for the stable minority carrier lifetime to account for the bulk recombination caused by the formation of boron-oxygen complexes under carrier injection.

  8. Application of XAD-resin based passive air samplers to assess local (roadside) and regional patterns of persistent organic pollutants.

    PubMed

    Barthel, Paul; Thuens, Sabine; Shunthirasingham, Chubashini; Westgate, John N; Wania, Frank; Radke, Michael

    2012-07-01

    We used XAD-resin based passive air samplers (PAS) to measure atmospheric levels of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) at five ombrotrophic bogs in Eastern Canada. The aims of our study were to investigate the influence of local roads on contaminant levels in the bogs, to derive the regional pattern of atmospheric concentrations, and to assess the uncertainties of the method. Expanded uncertainties based on the duplicate PAS deployed at 24 sites were good for the PAHs, while the deployment period of approx. 100 days was too short to yield acceptable uncertainties for PCBs. The regional PAH distribution was in good agreement with the calculated source proximity of the sampled bogs. We conclude that XAD-resin based PAS deployed for comparatively short periods are well suited for measuring atmospheric concentrations of volatile PAHs, while in remote regions longer deployment is necessary for less volatile PAHs and for PCBs.

  9. Passive Acoustic Source Localization at a Low Sampling Rate Based on a Five-Element Cross Microphone Array

    PubMed Central

    Kan, Yue; Wang, Pengfei; Zha, Fusheng; Li, Mantian; Gao, Wa; Song, Baoyu

    2015-01-01

    Accurate acoustic source localization at a low sampling rate (less than 10 kHz) is still a challenging problem for small portable systems, especially for a multitasking micro-embedded system. A modification of the generalized cross-correlation (GCC) method with the up-sampling (US) theory is proposed and defined as the US-GCC method, which can improve the accuracy of the time delay of arrival (TDOA) and source location at a low sampling rate. In this work, through the US operation, an input signal with a certain sampling rate can be converted into another signal with a higher frequency. Furthermore, the optimal interpolation factor for the US operation is derived according to localization computation time and the standard deviation (SD) of target location estimations. On the one hand, simulation results show that absolute errors of the source locations based on the US-GCC method with an interpolation factor of 15 are approximately from 1/15- to 1/12-times those based on the GCC method, when the initial same sampling rates of both methods are 8 kHz. On the other hand, a simple and small portable passive acoustic source localization platform composed of a five-element cross microphone array has been designed and set up in this paper. The experiments on the established platform, which accurately locates a three-dimensional (3D) near-field target at a low sampling rate demonstrate that the proposed method is workable. PMID:26057042

  10. Passive Acoustic Source Localization at a Low Sampling Rate Based on a Five-Element Cross Microphone Array.

    PubMed

    Kan, Yue; Wang, Pengfei; Zha, Fusheng; Li, Mantian; Gao, Wa; Song, Baoyu

    2015-06-05

    Accurate acoustic source localization at a low sampling rate (less than 10 kHz) is still a challenging problem for small portable systems, especially for a multitasking micro-embedded system. A modification of the generalized cross-correlation (GCC) method with the up-sampling (US) theory is proposed and defined as the US-GCC method, which can improve the accuracy of the time delay of arrival (TDOA) and source location at a low sampling rate. In this work, through the US operation, an input signal with a certain sampling rate can be converted into another signal with a higher frequency. Furthermore, the optimal interpolation factor for the US operation is derived according to localization computation time and the standard deviation (SD) of target location estimations. On the one hand, simulation results show that absolute errors of the source locations based on the US-GCC method with an interpolation factor of 15 are approximately from 1/15- to 1/12-times those based on the GCC method, when the initial same sampling rates of both methods are 8 kHz. On the other hand, a simple and small portable passive acoustic source localization platform composed of a five-element cross microphone array has been designed and set up in this paper. The experiments on the established platform, which accurately locates a three-dimensional (3D) near-field target at a low sampling rate demonstrate that the proposed method is workable.

  11. Advanced Methods for Passive Acoustic Detection, Classification, and Localization of Marine Mammals

    DTIC Science & Technology

    2015-09-30

    marine mammal vocalizations and ultimately, in some cases, provide data for estimating the population density of the species present. In recent years...pose significant challenges. In this project, we are developing improved methods for detection, classification, and localization of many types of marine mammal sounds.

  12. Achieving Passive Localization with Traffic Light Schedules in Urban Road Sensor Networks

    PubMed Central

    Niu, Qiang; Yang, Xu; Gao, Shouwan; Chen, Pengpeng; Chan, Shibing

    2016-01-01

    Localization is crucial for the monitoring applications of cities, such as road monitoring, environment surveillance, vehicle tracking, etc. In urban road sensor networks, sensors are often sparely deployed due to the hardware cost. Under this sparse deployment, sensors cannot communicate with each other via ranging hardware or one-hop connectivity, rendering the existing localization solutions ineffective. To address this issue, this paper proposes a novel Traffic Lights Schedule-based localization algorithm (TLS), which is built on the fact that vehicles move through the intersection with a known traffic light schedule. We can first obtain the law by binary vehicle detection time stamps and describe the law as a matrix, called a detection matrix. At the same time, we can also use the known traffic light information to construct the matrices, which can be formed as a collection called a known matrix collection. The detection matrix is then matched in the known matrix collection for identifying where sensors are located on urban roads. We evaluate our algorithm by extensive simulation. The results show that the localization accuracy of intersection sensors can reach more than 90%. In addition, we compare it with a state-of-the-art algorithm and prove that it has a wider operational region. PMID:27735871

  13. Local Ownership of Education Policies at the Crossroads between the Active Participation and the Passive Compliance to International Goals

    ERIC Educational Resources Information Center

    Imaniriho, Dan

    2015-01-01

    Over the past three decades, perceptions about the role of local population in policy development process have deeply changed. This change is related to the idea promoted by international institutions that the development actions cannot succeed without a strong local ownership and a broad approach that guarantee active participation of local…

  14. Advanced Methods for Passive Acoustic Detection, Classification, and Localization of Marine Mammals

    DTIC Science & Technology

    2014-09-30

    in the case of aerial surveys, significantly dangerous . In both the areas critical to the Navy and in other areas critical to marine mammals, PAM... animal calls via hyperbolic methods, Journal of the Acoustical Society of merica 97, 3352–3353 (1995). Morrissey, R. P., J. Ward, N. DiMarzio, S... animal as it follows its prey just prior to capture. Figure 6: Example of tracking highly ambiguous localizations. 15 Figure 7

  15. Local oscillator phase noise limitation on the resolution of acoustic delay line wireless passive sensor measurement

    NASA Astrophysics Data System (ADS)

    Chrétien, N.; Friedt, J.-M.; Martin, G.

    2014-06-01

    The role of the phase noise of a local oscillator driving a pulsed-mode RADAR used for probing surface acoustic wave sensors is investigated. The echo delay, representative of the acoustic velocity, and hence the physical quantity probed by the sensor, is finely measured as a phase. Considering that the intrinsic oscillator phase fluctuation defines the phase noise measurement resolution, we experimentally and theoretically assess the relation between phase noise, measurement range, and measurand resolution.

  16. Passive ranging errors due to multipath distortion of deterministic transient signals with application to the localization of small arms fire

    NASA Astrophysics Data System (ADS)

    Ferguson, Brian G.; Lo, Kam W.

    2002-01-01

    A passive ranging technique based on wavefront curvature is used to estimate the ranges and bearings of impulsive sound sources represented by small arms fire. The discharge of a firearm results in the generation of a transient acoustic signal whose energy propagates radially outwards from the omnidirectional source. The radius of curvature of the spherical wavefront at any instant is equal to the instantaneous range from the source. The curvature of the acoustic wavefront is sensed with a three-microphone linear array by first estimating the differential time of arrival (or time delay) of the acoustic wavefront at each of the two adjacent sensor pairs and then processing the time-delay information to extract the range and bearing of the source. However, modeling the passive ranging performance of the wavefront curvature method for a deterministic transient signal source in a multipath environment shows that when the multipath and direct path arrivals are unresolvable, the time-delay estimates are biased which, in turn, biases the range estimates. The model explains the observed under-ranging of small arms firing positions during a field experiment.

  17. Passive ranging errors due to multipath distortion of deterministic transient signals with application to the localization of small arms fire.

    PubMed

    Ferguson, Brian G; Lo, Kam W

    2002-01-01

    A passive ranging technique based on wavefront curvature is used to estimate the ranges and bearings of impulsive sound sources represented by small arms fire. The discharge of a firearm results in the generation of a transient acoustic signal whose energy propagates radially outwards from the omnidirectional source. The radius of curvature of the spherical wavefront at any instant is equal to the instantaneous range from the source. The curvature of the acoustic wavefront is sensed with a three-microphone linear array by first estimating the differential time of arrival (or time delay) of the acoustic wavefront at each of the two adjacent sensor pairs and then processing the time-delay information to extract the range and bearing of the source. However, modeling the passive ranging performance of the wavefront curvature method for a deterministic transient signal source in a multipath environment shows that when the multipath and direct path arrivals are unresolvable, the time-delay estimates are biased which, in turn, biases the range estimates. The model explains the observed under-ranging of small arms firing positions during a field experiment.

  18. Is water uptake by reptilian eggs regulated by physiological processes of embryos or a passive hydraulic response to developmental environments?

    PubMed

    Warner, Daniel A; Moody, Melissa A; Telemeco, Rory S

    2011-11-01

    Moisture availability is critical for successful embryonic development in many organisms. In most oviparous reptiles, for example, water exchange between eggs and the surrounding environment can have substantial fitness consequences, but regulation of this process is unclear. Here, we evaluate whether water uptake by eggs of the lizard Anolis sagrei is regulated by the presence of a live embryo or is a passive hydraulic response to substrate moisture conditions. Many eggs laid in our captive colony were infertile or contained embryos that died during early stages of development, yet these 'dead' eggs continued to gain mass similar to that of 'live' eggs at least during the first half of incubation. Our results suggest that water uptake by eggs is largely a passive hydraulic process during the first half of incubation, but active regulation by embryos may be necessary during latter stages. Maternal effects (e.g., deposition of salts into yolk) could influence this passive process during early incubation.

  19. Geometric Properties of Dynamic Nonlinear Networks: Transversality, Local-Solvability and Eventual Passivity,

    DTIC Science & Technology

    1979-09-17

    space to be a tions which lie at the very foundation of nonlinear circuit submanifold. Main result of the paper state% that a network is locagls... circuit of Fig. 1(a). wherc A, (DF) 1R 1 DF j , 11 *1 is described by q-g.( ) as in Fig. I(b). Then ’ C) isa DF I [ 8DF , II BR .’ proper tree. BR( I and R...is locally (r,. ,q.," corresponds to open- circuiting branches of voltage (resp. current) controlled. Then there is a perturba- (’ and short

  20. High Accuracy Passive Magnetic Field-Based Localization for Feedback Control Using Principal Component Analysis.

    PubMed

    Foong, Shaohui; Sun, Zhenglong

    2016-08-12

    In this paper, a novel magnetic field-based sensing system employing statistically optimized concurrent multiple sensor outputs for precise field-position association and localization is presented. This method capitalizes on the independence between simultaneous spatial field measurements at multiple locations to induce unique correspondences between field and position. This single-source-multi-sensor configuration is able to achieve accurate and precise localization and tracking of translational motion without contact over large travel distances for feedback control. Principal component analysis (PCA) is used as a pseudo-linear filter to optimally reduce the dimensions of the multi-sensor output space for computationally efficient field-position mapping with artificial neural networks (ANNs). Numerical simulations are employed to investigate the effects of geometric parameters and Gaussian noise corruption on PCA assisted ANN mapping performance. Using a 9-sensor network, the sensing accuracy and closed-loop tracking performance of the proposed optimal field-based sensing system is experimentally evaluated on a linear actuator with a significantly more expensive optical encoder as a comparison.

  1. The route of passive chloride movement across amphibian skin: localization and regulatory mechanisms.

    PubMed

    Nagel, Wolfram; Somieski, Petra; Katz, Uri

    2002-11-13

    Transepithelial Cl(-) conductance (G(Cl)) in amphibian skin can be activated in several species by serosa positive potentials. Mitochondria-rich cells (MRC) or tight junctions (TJ) between the epithelial cells are possible sites for this pathway. The properties and the techniques used to investigate this pathway are reviewed in the present paper. In situ techniques are preferable, since specific properties of the MRC are apparently not maintained in isolated cells. Volume measurements and electronprobe microanalysis of intracellular ions suggest the localization of voltage-activated G(Cl) to MRC. G(Cl) correlates poorly with the density of MRC. The vibrating voltage probe allows quantitative correlation of the local Cl(-) current through morphologically identified structures and the transepithelial Cl(-) current. Our analysis shows that 80% of the voltage-activated Cl(-) current is accounted for by current through MRC or their immediate vicinity. The activation patterns of this current and the inhibition by the alpha(1)-adrenergic agonist, epinephrine, conform to those of the transepithelial current. However, less than 20% of the MRC are active at a certain moment and the activity is spontaneously variable with time. The molecular nature of this pathway, physiological control mechanisms and their relation to the temporal activity of MRC remain to be studied.

  2. Underwater passive acoustic localization of Pacific walruses in the northeastern Chukchi Sea.

    PubMed

    Rideout, Brendan P; Dosso, Stan E; Hannay, David E

    2013-09-01

    This paper develops and applies a linearized Bayesian localization algorithm based on acoustic arrival times of marine mammal vocalizations at spatially-separated receivers which provides three-dimensional (3D) location estimates with rigorous uncertainty analysis. To properly account for uncertainty in receiver parameters (3D hydrophone locations and synchronization times) and environmental parameters (water depth and sound-speed correction), these quantities are treated as unknowns constrained by prior estimates and prior uncertainties. Unknown scaling factors on both the prior and arrival-time uncertainties are estimated by minimizing Akaike's Bayesian information criterion (a maximum entropy condition). Maximum a posteriori estimates for sound source locations and times, receiver parameters, and environmental parameters are calculated simultaneously using measurements of arrival times for direct and interface-reflected acoustic paths. Posterior uncertainties for all unknowns incorporate both arrival time and prior uncertainties. Monte Carlo simulation results demonstrate that, for the cases considered here, linearization errors are small and the lack of an accurate sound-speed profile does not cause significant biases in the estimated locations. A sequence of Pacific walrus vocalizations, recorded in the Chukchi Sea northwest of Alaska, is localized using this technique, yielding a track estimate and uncertainties with an estimated speed comparable to normal walrus swim speeds.

  3. High Accuracy Passive Magnetic Field-Based Localization for Feedback Control Using Principal Component Analysis

    PubMed Central

    Foong, Shaohui; Sun, Zhenglong

    2016-01-01

    In this paper, a novel magnetic field-based sensing system employing statistically optimized concurrent multiple sensor outputs for precise field-position association and localization is presented. This method capitalizes on the independence between simultaneous spatial field measurements at multiple locations to induce unique correspondences between field and position. This single-source-multi-sensor configuration is able to achieve accurate and precise localization and tracking of translational motion without contact over large travel distances for feedback control. Principal component analysis (PCA) is used as a pseudo-linear filter to optimally reduce the dimensions of the multi-sensor output space for computationally efficient field-position mapping with artificial neural networks (ANNs). Numerical simulations are employed to investigate the effects of geometric parameters and Gaussian noise corruption on PCA assisted ANN mapping performance. Using a 9-sensor network, the sensing accuracy and closed-loop tracking performance of the proposed optimal field-based sensing system is experimentally evaluated on a linear actuator with a significantly more expensive optical encoder as a comparison. PMID:27529253

  4. Effects of Active and Passive Hearing Protection Devices on Sound Source Localization, Speech Recognition, and Tone Detection

    PubMed Central

    Brown, Andrew D.; Beemer, Brianne T.; Greene, Nathaniel T.; Argo, Theodore; Meegan, G. Douglas; Tollin, Daniel J.

    2015-01-01

    Hearing protection devices (HPDs) such as earplugs offer to mitigate noise exposure and reduce the incidence of hearing loss among persons frequently exposed to intense sound. However, distortions of spatial acoustic information and reduced audibility of low-intensity sounds caused by many existing HPDs can make their use untenable in high-risk (e.g., military or law enforcement) environments where auditory situational awareness is imperative. Here we assessed (1) sound source localization accuracy using a head-turning paradigm, (2) speech-in-noise recognition using a modified version of the QuickSIN test, and (3) tone detection thresholds using a two-alternative forced-choice task. Subjects were 10 young normal-hearing males. Four different HPDs were tested (two active, two passive), including two new and previously untested devices. Relative to unoccluded (control) performance, all tested HPDs significantly degraded performance across tasks, although one active HPD slightly improved high-frequency tone detection thresholds and did not degrade speech recognition. Behavioral data were examined with respect to head-related transfer functions measured using a binaural manikin with and without tested HPDs in place. Data reinforce previous reports that HPDs significantly compromise a variety of auditory perceptual facilities, particularly sound localization due to distortions of high-frequency spectral cues that are important for the avoidance of front-back confusions. PMID:26313145

  5. Passive acoustic detection and localization of whales: effects of shipping noise in Saguenay-St. Lawrence Marine Park.

    PubMed

    Simard, Yvan; Roy, Nathalie; Gervaise, Cédric

    2008-06-01

    The performance of large-aperture hydrophone arrays to detect and localize blue and fin whales' 15-85 Hz signature vocalizations under ocean noise conditions was assessed through simulations from a normal mode propagation model combined to noise statistics from 15 960 h of recordings in Saguenay-St. Lawrence Marine Park. The probability density functions of 2482 summer noise level estimates in the call bands were used to attach a probability of detection/masking to the simulated call levels as a function of whale depth and range for typical environmental conditions. Results indicate that call detection was modulated by the calling depth relative to the sound channel axis and by modal constructive and destructive interferences with range. Masking of loud infrasounds could reach 40% at 30 km for a receiver at the optimal depth. The 30 dB weaker blue whale D-call were subject to severe masking. Mapping the percentages of detection and localization allowed assessing the performance of a six-hydrophone array under mean- and low-noise conditions. This approach is helpful for optimizing hydrophone configuration in implementing passive acoustic monitoring arrays and building their detection function for whale density assessment, as an alternative to or in combination with the traditional undersampling visual methods.

  6. Passive solar technology

    SciTech Connect

    Watson, D

    1981-04-01

    The present status of passive solar technology is summarized, including passive solar heating, cooling and daylighting. The key roles of the passive solar system designer and of innovation in the building industry are described. After definitions of passive design and a summary of passive design principles are given, performance and costs of passive solar technology are discussed. Passive energy design concepts or methods are then considered in the context of the overall process by which building decisions are made to achieve the integration of new techniques into conventional design. (LEW).

  7. Efficient and stable solution-processed planar perovskite solar cells via contact passivation.

    PubMed

    Tan, Hairen; Jain, Ankit; Voznyy, Oleksandr; Lan, Xinzheng; García de Arquer, F Pelayo; Fan, James Z; Quintero-Bermudez, Rafael; Yuan, Mingjian; Zhang, Bo; Zhao, Yicheng; Fan, Fengjia; Li, Peicheng; Quan, Li Na; Zhao, Yongbiao; Lu, Zheng-Hong; Yang, Zhenyu; Hoogland, Sjoerd; Sargent, Edward H

    2017-02-17

    Planar perovskite solar cells (PSCs) made entirely via solution processing at low temperatures (<150°C) offer promise for simple manufacturing, compatibility with flexible substrates, and perovskite-based tandem devices. However, these PSCs require an electron-selective layer that performs well with similar processing. We report a contact-passivation strategy using chlorine-capped TiO2 colloidal nanocrystal film that mitigates interfacial recombination and improves interface binding in low-temperature planar solar cells. We fabricated solar cells with certified efficiencies of 20.1 and 19.5% for active areas of 0.049 and 1.1 square centimeters, respectively, achieved via low-temperature solution processing. Solar cells with efficiency greater than 20% retained 90% (97% after dark recovery) of their initial performance after 500 hours of continuous room-temperature operation at their maximum power point under 1-sun illumination (where 1 sun is defined as the standard illumination at AM1.5, or 1 kilowatt/square meter).

  8. Efficient and stable solution-processed planar perovskite solar cells via contact passivation

    NASA Astrophysics Data System (ADS)

    Tan, Hairen; Jain, Ankit; Voznyy, Oleksandr; Lan, Xinzheng; García de Arquer, F. Pelayo; Fan, James Z.; Quintero-Bermudez, Rafael; Yuan, Mingjian; Zhang, Bo; Zhao, Yicheng; Fan, Fengjia; Li, Peicheng; Quan, Li Na; Zhao, Yongbiao; Lu, Zheng-Hong; Yang, Zhenyu; Hoogland, Sjoerd; Sargent, Edward H.

    2017-02-01

    Planar perovskite solar cells (PSCs) made entirely via solution processing at low temperatures (<150°C) offer promise for simple manufacturing, compatibility with flexible substrates, and perovskite-based tandem devices. However, these PSCs require an electron-selective layer that performs well with similar processing. We report a contact-passivation strategy using chlorine-capped TiO2 colloidal nanocrystal film that mitigates interfacial recombination and improves interface binding in low-temperature planar solar cells. We fabricated solar cells with certified efficiencies of 20.1 and 19.5% for active areas of 0.049 and 1.1 square centimeters, respectively, achieved via low-temperature solution processing. Solar cells with efficiency greater than 20% retained 90% (97% after dark recovery) of their initial performance after 500 hours of continuous room-temperature operation at their maximum power point under 1-sun illumination (where 1 sun is defined as the standard illumination at AM1.5, or 1 kilowatt/square meter).

  9. Fluid transport processes in the passive margins of the Eastern Mediterranean

    NASA Astrophysics Data System (ADS)

    Bertoni, Claudia; Foschi, Martino; Cartwright, Joe; Levell, Bruce

    2015-04-01

    We analyse and produce a synoptic model of the different styles of fluid transport occurring in the various passive margin settings in the Eastern Mediterranean. The common tectonic-stratigraphic setting is dominated, from the Mesozoic, by the interaction of the Tethyan platforms with Cenozoic to recent, mainly clastic, deposits interacting with the ubiquitous thick late Miocene (Messinian) evaporitic sediments. This created different specific modes of fluid-lithology coupling behaviours, and generated an extraordinary suite of seismically resolvable fluid flow phenomena, including mud volcanoes, pockmarks, dissolution/collapse structures, chimneys and pipes. We integrate this evidence with the analysis of the regional pressure/temperature gradient, and with published hydrocarbon generation models, to propose a regional synthesis of all fluid transport processes in a specific basinal context. We place the fluid flow evidence observed in the Eastern Mediterranean in the framework of the three main fluid flow settings, which are typically defined in sedimentary basins, in terms of depth: 1) A thermobaric fluid regime, where fluid transport is limited and convection can be the dominant transport mechanism, 2) A thermogenic regime, where fluids supplied by hydrocarbon generation can migrate by hydraulic fracturing and advection (along open faults/conduits), by matrix flow and in the longer term, by diffusion processes, 3) A shallow compactional regime, where the fluids are generated by sediment dewatering and shallow diagenesis, and the main transport mechanism is characterised by vertical fluid flow, either through advection and hydrofracturing along faults, or matrix flow. In the Eastern Mediterranean passive margins, this depth-related subdivision needs to be modified in order to accommodate the influence of the laterally and vertically extensive evaporitic series, which acts as a regional aquitard/aquiclude to water or a seal to hydrocarbon flow. The presence of

  10. Solution-processed gadolinium doped indium-oxide thin-film transistors with oxide passivation

    NASA Astrophysics Data System (ADS)

    Lee, Seung-Hun; Kim, Taehun; Lee, Jihun; Avis, Christophe; Jang, Jin

    2017-03-01

    We studied the effect of Gd doping on the structural properties of solution processed, crystalline In2O3 for thin-film transistor (TFT) application. With increasing Gd in In2O3 up to 20%, the material structure changes into amorphous phase, and the oxygen vacancy concentration decreases from 15.4 to 8.4%, and M-OH bonds from 33.5 to 23.7%. The field-effect mobility for the Gd doped In2O3 TFTs decreases and threshold voltage shifts to the positive voltage with increasing Gd concentration. In addition, the stability of the solution processed TFTs can also be improved by increasing Gd concentration. As a result, the optimum Gd concentration is found to be ˜5% in In2O3 and the 5% Gd doped In2O3 TFTs with the Y2O3 passivation layer exhibit the linear mobility of 9.74 cm2/V s, the threshold voltage of -0.27 V, the subthreshold swing of 79 mV/dec., and excellent bias stability.

  11. A PROPOSED METHOD FOR ESTIMATING FAILURE RATES OF DEGRADED PASSIVE COMPONENTS IN THE NRC SIGNIFICANCE DETERMINATION PROCESS

    SciTech Connect

    Unwin, Stephen D.; Johnson, Kenneth I.; Ivans, William J.; Lowry, Peter P.

    2013-11-01

    This paper outlines a methodology for estimation of the incremental core damage frequency associated with the degradation of passive components with a view to its application in the US Nuclear Regulatory Commission's significance determination process. The method involves use of simplified physics-based models of materials degradation and the probabilistic comparison of transient loads with deteriorating system capacities.

  12. The Comparative Effects of Processing Instruction and Dictogloss on the Acquisition of the English Passive by Speakers of Turkish

    ERIC Educational Resources Information Center

    Uludag, Onur; Vanpatten, Bill

    2012-01-01

    The current study presents the results of an experiment investigating the effects of processing instruction (PI) and dictogloss (DG) on the acquisition of the English passive voice. Sixty speakers of Turkish studying English at university level were assigned to three groups: one receiving PI, the other receiving DG and the third serving as a…

  13. Is Broca's Area Involved in the Processing of Passive Sentences? An Event-Related fMRI Study

    ERIC Educational Resources Information Center

    Yokoyama, Satoru; Watanabe, Jobu; Iwata, Kazuki; Ikuta, Naho; Haji, Tomoki; Usui, Nobuo; Taira, Masato; Miyamoto, Tadao; Nakamura, Wataru; Sato, Shigeru; Horie, Kaoru; Kawashima, Ryuta

    2007-01-01

    We used functional magnetic resonance imaging (fMRI) to investigate whether activation in Broca's area is greater during the processing of passive versus active sentences in the brains of healthy subjects. Twenty Japanese native speakers performed a visual sentence comprehension task in which they were asked to read a visually presented sentence…

  14. Nearly Monodispersion CoSm Alloy Nanoparticles Formed by an In-situ Rapid Cooling and Passivating Microfluidic Process.

    PubMed

    Song, Yujun; Henry, Laurence L

    2009-06-14

    An in siturapid cooling and passivating microfluidic processhas been developed for the synthesis of nearly monodispersed cobalt samarium nanoparticles (NPs) with tunable crystal structures and surface properties. This process involves promoting the nucleation and growth of NPs at an elevated temperature and rapidly quenching the NP colloids in a solution containing a passivating reagent at a reduced temperature. We have shown that Cobalt samarium NPs having amorphous crystal structures and a thin passivating layer can be synthesized with uniform nonspherical shapes and size of about 4.8 nm. The amorphous CoSm NPs in our study have blocking temperature near 40 K and average coercivity of 225 Oe at 10 K. The NPs also exhibit high anisotropic magnetic properties with a wasp-waist hysteresis loop and a bias shift of coercivity due to the shape anisotropy and the exchange coupling between the core and the thin oxidized surface layer.

  15. Quality of Life and Toxicity From Passively Scattered and Spot-Scanning Proton Beam Therapy for Localized Prostate Cancer

    SciTech Connect

    Pugh, Thomas J.; Munsell, Mark F.; Choi, Seungtaek; Nguyen, Quyhn Nhu; Mathai, Benson; Zhu, X. Ron; Sahoo, Narayan; Gillin, Michael; Johnson, Jennifer L.; Amos, Richard A.; Dong, Lei; Mahmood, Usama; Kuban, Deborah A.; Frank, Steven J.; Hoffman, Karen E.; McGuire, Sean E.; Lee, Andrew K.

    2013-12-01

    Purpose: To report quality of life (QOL)/toxicity in men treated with proton beam therapy for localized prostate cancer and to compare outcomes between passively scattered proton therapy (PSPT) and spot-scanning proton therapy (SSPT). Methods and Materials: Men with localized prostate cancer enrolled on a prospective QOL protocol with a minimum of 2 years' follow-up were reviewed. Comparative groups were defined by technique (PSPT vs SSPT). Patients completed Expanded Prostate Cancer Index Composite questionnaires at baseline and every 3-6 months after proton beam therapy. Clinically meaningful differences in QOL were defined as ≥0.5 × baseline standard deviation. The cumulative incidence of modified Radiation Therapy Oncology Group grade ≥2 gastrointestinal (GI) or genitourinary (GU) toxicity and argon plasma coagulation were determined by the Kaplan-Meier method. Results: A total of 226 men received PSPT, and 65 received SSPT. Both PSPT and SSPT resulted in statistically significant changes in sexual, urinary, and bowel Expanded Prostate Cancer Index Composite summary scores. Only bowel summary, function, and bother resulted in clinically meaningful decrements beyond treatment completion. The decrement in bowel QOL persisted through 24-month follow-up. Cumulative grade ≥2 GU and GI toxicity at 24 months were 13.4% and 9.6%, respectively. There was 1 grade 3 GI toxicity (PSPT group) and no other grade ≥3 GI or GU toxicity. Argon plasma coagulation application was infrequent (PSPT 4.4% vs SSPT 1.5%; P=.21). No statistically significant differences were appreciated between PSPT and SSPT regarding toxicity or QOL. Conclusion: Both PSPT and SSPT confer low rates of grade ≥2 GI or GU toxicity, with preservation of meaningful sexual and urinary QOL at 24 months. A modest, yet clinically meaningful, decrement in bowel QOL was seen throughout follow-up. No toxicity or QOL differences between PSPT and SSPT were identified. Long-term comparative results in a

  16. Finite-size effects on electronic structure and local properties in passivated AA-stacked bilayer armchair-edge graphene nanoribbons.

    PubMed

    Chen, Xiongwen; Shi, Zhengang; Xiang, Shaohua; Song, Kehui; Zhou, Guanghui

    2017-03-01

    Based on the tight-binding model and dual-probe scanning tunneling microscopy technology, we theoretically investigate the electronic structure and local property in the passivated AA-stacked bilayer armchair-edge graphene nanoribbons (AABLAGNRs). We show that they are highly sensitive to the size of the ribbons, which is evidently different from the single-layer armchair-edge graphene nanoribbons. The '3p' rule only applies to the narrow AABLGNRs. Namely, in the passivated 3p- and (3p  +  1)-AABLGNRs, the narrow ribbons are semiconducting while the medium and wide ribbons are metallic. Although the passivated (3p  +  2)-AABLGNRs are metallic, the '3j' rule only applies to the narrow and medium ribbons. Namely, electrons are in the semiconducting states at sites of line 3j while they are in the metallic states at other sites. This induces a series of parallel and discrete metallic channels, consisting of lines 3j  -  1 and 3j  -  2, for the low-energy electronic transports. In the passivated wide (3p  +  2)-AABLGNRs, all electrons are in the metallic states. Additionally, the '3p' and '3j' rules are controllable to disappear and reappear by applying an external perpendicular electric field. Resultantly, an electric filed-driven current switch can be realized in the passivated narrow and medium (3p  +  2)-AABLGNRs.

  17. Finite-size effects on electronic structure and local properties in passivated AA-stacked bilayer armchair-edge graphene nanoribbons

    NASA Astrophysics Data System (ADS)

    Chen, Xiongwen; Shi, Zhengang; Xiang, Shaohua; Song, Kehui; Zhou, Guanghui

    2017-03-01

    Based on the tight-binding model and dual-probe scanning tunneling microscopy technology, we theoretically investigate the electronic structure and local property in the passivated AA-stacked bilayer armchair-edge graphene nanoribbons (AABLAGNRs). We show that they are highly sensitive to the size of the ribbons, which is evidently different from the single-layer armchair-edge graphene nanoribbons. The ‘3p’ rule only applies to the narrow AABLGNRs. Namely, in the passivated 3p- and (3p  +  1)-AABLGNRs, the narrow ribbons are semiconducting while the medium and wide ribbons are metallic. Although the passivated (3p  +  2)-AABLGNRs are metallic, the ‘3j’ rule only applies to the narrow and medium ribbons. Namely, electrons are in the semiconducting states at sites of line 3j while they are in the metallic states at other sites. This induces a series of parallel and discrete metallic channels, consisting of lines 3j  -  1 and 3j  -  2, for the low-energy electronic transports. In the passivated wide (3p  +  2)-AABLGNRs, all electrons are in the metallic states. Additionally, the ‘3p’ and ‘3j’ rules are controllable to disappear and reappear by applying an external perpendicular electric field. Resultantly, an electric filed-driven current switch can be realized in the passivated narrow and medium (3p  +  2)-AABLGNRs.

  18. Effects of obesity and mild hypohydration on local sweating and cutaneous vascular responses during passive heat stress in females.

    PubMed

    Moyen, Nicole E; Burchfield, Jenna M; Butts, Cory L; Glenn, Jordan M; Tucker, Matthew A; Treece, Keeley; Smith, Amber J; McDermott, Brendon P; Ganio, Matthew S

    2016-08-01

    The purpose of this study was to evaluate the effect of obesity and mild hypohydration on local sweating (LSR) and cutaneous vascular conductance (CVC) responses during passive heat stress in females. Thirteen obese (age, 24 ± 4 years; 45.4% ± 5.2% body fat) and 12 nonobese (age, 22 ± 2 years; 25.1% ± 3.9% body fat) females were passively heated (1.0 °C rectal temperature increase) while either euhydrated (EUHY) or mildly hypohydrated (HYPO; via fluid restriction). Chest and forearm LSR (ventilated capsule) and CVC (Laser Doppler flowmetry) onset, sensitivity, and plateau/steady state were recorded as mean body temperature increased (ΔTb). Participants began trials EUHY (urine specific gravity, Usg = 1.009 ± 0.006) or HYPO (Usg = 1.025 ± 0.004; p < 0.05), and remained EUHY or HYPO. Independent of obesity, HYPO decreased sweat sensitivity at the chest (HYPO = 0.79 ± 0.35, EUHY = 0.95 ± 0.39 Δmg·min(-1)·cm(-2)/°C ΔTb) and forearm (HYPO = 0.82 ± 0.39, EUHY = 1.06 ± 0.34 Δmg·min(-1)·cm(-2)/°C ΔTb); forearm LSR plateau was also decreased (HYPO = 0.66 ± 0.19, EUHY = 0.78 ± 0.23 mg·min(-1)·cm(-2); all p < 0.05). Overall, obese females had lower chest-sweat sensitivity (0.72 ± 0.35 vs. 1.01 ± 0.33 Δmg·min(-1)·cm(-2)/°C ΔTb) and plateau (0.55 ± 0.27 vs. 0.80 ± 0.25 mg·min(-1)·cm(-2); p < 0.05). While hypohydrated, obese females had a lower chest LSR (p < 0.05) versus nonobese females midway (0.45 ± 0.26 vs. 0.73 ± 0.23 mg·min(-1)·cm(-2)) and at the end (0.53 ± 0.27 vs. 0.81 ± 0.24 mg·min(-1)·cm(-2)) of heating. Furthermore, HYPO (relative to the EUHY trials) led to a greater decrease in CVC sensitivity in obese (-28 ± 27 Δ% maximal CVC/°C ΔTb) versus nonobese females (+9.2 ± 33 Δ% maximal CVC/°C ΔTb; p < 0.05). In conclusion, mild hypohydration impairs females' sweating responses during passive heat stress, and this effect is exacerbated when obese.

  19. Surface Passivation for 3-5 Semiconductor Processing: Stable Gallium Sulphide Films by MOCVD

    NASA Technical Reports Server (NTRS)

    Macinnes, Andrew N.; Jenkins, Phillip P.; Power, Michael B.; Kang, Soon; Barron, Andrew R.; Hepp, Aloysius F.; Tabib-Azar, Massood

    1994-01-01

    Gallium sulphide (GaS) has been deposited on GaAs to form stable, insulating, passivating layers. Spectrally resolved photoluminescence and surface recombination velocity measurements indicate that the GaS itself can contribute a significant fraction of the photoluminescence in GaS/GaAs structures. Determination of surface recombination velocity by photoluminescence is therefore difficult. By using C-V analysis of metal-insulator-semiconductor structures, passivation of the GaAs with GaS films is quantified.

  20. Local infiltration of rabies immunoglobulins without systemic intramuscular administration: An alternative cost effective approach for passive immunization against rabies

    PubMed Central

    Bharti, Omesh Kumar; Madhusudana, Shampur Narayan; Gaunta, Pyare Lal; Belludi, Ashwin Yajaman

    2016-01-01

    ABSTRACT Presently the dose of rabies immunoglobulin (RIG) which is an integral part of rabies post exposure prophylaxis (PEP) is calculated based on body weight though the recommendation is to infiltrate the wound(s). This practice demands large quantities of RIG which may be unaffordable to many patients. In this background, we conducted this study to know if the quantity and cost of RIG can be reduced by restricting passive immunization to local infiltration alone and avoiding systemic intramuscular administration based on the available scientific evidence. Two hundred and sixty nine category III patients bitten by suspect or confirmed rabid dogs/animals were infiltrated with equine rabies immunoglobulin (ERIGs) in and around the wound. The quantity of ERIG used was proportionate to the size and number of wounds irrespective of their body weight. They were followed with a regular course of rabies vaccination by intra-dermal route. As against 363 vials of RIGs required for all these cases as per current recommendation based on body weight, they required only 42 vials of 5ml RIG. Minimum dose of RIGs given was 0.25 ml and maximum dose given was 8 ml. On an average 1.26 ml of RIGs was required per patient that costs Rs. 150 ($3). All the patients were followed for 9 months and they were healthy and normal at the end of observation period. With local infiltration, that required small quantities of RIG, the RIGs could be made available to all patients in times of short supply in the market. A total of 30 (11%) serum samples of patients were tested for rabies virus neutralizing antibodies by the rapid fluorescent focus inhibition test (RFFIT) and all showed antibody titers >0.5 IU/mL by day 14. In no case the dose was higher than that required based on body weight and no immunosuppression resulted. To conclude, this pilot study shows that local infiltration of RIG need to be considered in times of non-availability in the market or unaffordability by poor patients

  1. Passivation process and the mechanism of packing particles in the Fe0/GAC system during the treatment of ABS resin wastewater.

    PubMed

    Lai, Bo; Zhou, Yuexi; Wang, Juling; Zhang, Yunhong; Chen, Zhiqiang

    2014-01-01

    This study provides mechanistic insights into the passivation of the packing particles during the treatment of acrylonitrile-butadiene-styrene (ABS) resin wastewater by the Fe0/GAC system. The granular-activated carbon (GAC) and iron chippings (Fe0) were mixed together with a volumetric ratio of 1:1. GAC has a mean particle size of approximately 3-5 mm, a specific surface of 748 m2 g(-1), a total pore volume of 0.48 mL g(-1) and a bulk density of 0.49 g cm(-3). The iron chippings have a compact and non-porous surface morphology. The results show that the packing particles in the Fe0/GAC system would lose their activity because the removal of TOC and PO4(3-) for ABS resin wastewater could not carried out by the Fe0/GAC system after 40 days continuous running. Meanwhile, the availability of O2 and intrinsic reactivity of Fe0 play a key role on the form of passive film with different iron oxidation states. The passive film on the surface of iron chippings was formed by two phases: (a) local corrosion phase (0-20 d) and (b) co-precipitation phase (20-40 d), while that of GAC was mainly formed by the co-precipitation of corrosion products with SO4(2-) and PO4(3-) because SO4(2-) and PO4(3-) would not easily reach the Fe0 surface. Therefore, in order to avoid the occurrence of filler passivation, high concentrations of SO4(2-) and PO4(3-) in wastewater should be removed before the treatment process of the Fe/GAC system.

  2. Geothermal policy development program: expediting the local geothermal permitting process

    SciTech Connect

    Not Available

    1981-07-01

    For a number of years, concerns have been raised about the length of time and the complexity involved in obtaining required permits in order to develop the geothermal resource at the Geysers. Perhaps the most important factor is jurisdiction. At the Geysers, all three levels of government - local, state, and federal - exercise significant authority over various aspects of geothermal development. In addition, several agencies within each governmental level play an active role in the permitting process. The present study is concerned primarily with the local permitting process, and the ways in which this process could be expedited. This report begins by looking at the local role in the overall permitting process, and then reviews the findings and conclusions that have been reached in other studies of the problem. This is followed by a case study evaluation of recent permitting experience in the four Geysers-Calistoga KGRA counties, and the report concludes by outlining several approaches to expediting the local permitting process.

  3. Deciphering the influence of the thermal processes on the early passive margins formation

    NASA Astrophysics Data System (ADS)

    Bousquet, Romain; Nalpas, Thierry; Ballard, Jean-François; Ringenbach, Jean-Claude; Chelalou, Roman; Clerc, Camille

    2015-04-01

    Many large-scale dynamic processes, from continental rifting to plate subduction, are intimately linked to metamorphic reactions. This close relation between geodynamic processes and metamorphic reactions is, in spite of appearances, yet poorly understood. For example, during extension processes, rocks will be exposed to important temperature, pressures and stress changes. Meanwhile less attention has been paid to other important aspects of the metamorphic processes. When reacting rocks expand and contract, density and volume changes will set up in the surrounding material. While several tectonic models are proposed to explain the formation of extensive basins and passive margins ( simple shear detachment mantle exhumation .... ) a single thermal model (McKenzie , 1978), as a dogma, is used to understanding and modeling the formation and evolution of sedimentary basins . This model is based on the assumption that the extension is only by pure shear and it is instantaneous. Under this approach, the sedimentary deposits occur in two stages. i) A short step , 1 to 10 Ma , controlled by tectonics. ii) A longer step , at least 50 Ma as a result of the thermal evolution of the lithosphere.
However, most stratigraphic data indicate that less thermal model can account for documented vertical movements. The study of the thermal evolution , coupled with other tectonic models , and its consequences have never been studied in detail , although the differences may be significant and it is clear that the petrological changes associated with changes in temperature conditions , influence changes reliefs.
In addition, it seems that the relationship between basin formation and thermal evolution is not always the same:
- Sometimes the temperature rise above 50 to 100 Ma tectonic extension. In the Alps, a significant rise in geothermal gradient Permo -Triassic followed by a "cold" extension , leading to the opening of the Ligurian- Piedmont ocean, from the Middle Jurassic .

  4. The use of passive, secure cells for processing of highly active nuclear wastes

    SciTech Connect

    Phillips, Ch.; Cavanah, P.; Richardson, J.

    2007-07-01

    Passive, secure cells (PSCs) have been used for over 50 years at the Sellafield nuclear site in the UK for radioactive processing plants. PSCs are designed and constructed with the expectation that there will be no need to enter them throughout the life of the plant. EnergySolutions has full and exclusive rights in North America to use the intellectual property and know-how generated at the Sellafield site and this includes all the design and operational data for PSCs. These data are thus available for use in the new build of nuclear plant currently being envisaged under the GNEP initiative. There are three types of PSC. Type 1 PSCs contain plant items with no maintainable moving parts, and pipework is all welded and radiographed to nuclear standards. Type 2 PSCs contain plant items with slowly rotating or intermittently moveable parts, but all maintainable items such as motors and gearboxes are located outside the cell, with sealed through-cell-wall drives. Type 3 PSCs are a newer design, dating from the 1980's, in which all maintainable in-cell items are designed as removable modules. The housings for the equipment are permanently welded into the in-cell pipework, and the modules can be withdrawn from these housings, through removable hatches in the PSC roof, into shielded steel 'flasks'. The flasks are moved to a maintenance cell where the modules are repaired or prepared for disposal. The process is reversed to re-install the modules back into service in the PSC. All three types of PSC have been shown to have operability, maintainability, reliability, space utilization, contamination control and worker radiation dose uptake advantages over canyon-based plants. The increased capital cost of PSCs over canyons is offset by decreased operating costs. Although PSCs have lower flexibility for process change than do canyons, this can be mitigated by the provision of spare cells and pipework at the design stage. Entry to PSCs is possible but has been required only

  5. Passive stimulation and behavioral training differentially transform temporal processing in the inferior colliculus and primary auditory cortex.

    PubMed

    Vollmer, Maike; Beitel, Ralph E; Schreiner, Christoph E; Leake, Patricia A

    2017-01-01

    In profoundly deaf cats, behavioral training with intracochlear electric stimulation (ICES) can improve temporal processing in the primary auditory cortex (AI). To investigate whether similar effects are manifest in the auditory midbrain, ICES was initiated in neonatally deafened cats either during development after short durations of deafness (8 wk of age) or in adulthood after long durations of deafness (≥3.5 yr). All of these animals received behaviorally meaningless, "passive" ICES. Some animals also received behavioral training with ICES. Two long-deaf cats received no ICES prior to acute electrophysiological recording. After several months of passive ICES and behavioral training, animals were anesthetized, and neuronal responses to pulse trains of increasing rates were recorded in the central (ICC) and external (ICX) nuclei of the inferior colliculus. Neuronal temporal response patterns (repetition rate coding, minimum latencies, response precision) were compared with results from recordings made in the AI of the same animals (Beitel RE, Vollmer M, Raggio MW, Schreiner CE. J Neurophysiol 106: 944-959, 2011; Vollmer M, Beitel RE. J Neurophysiol 106: 2423-2436, 2011). Passive ICES in long-deaf cats remediated severely degraded temporal processing in the ICC and had no effects in the ICX. In contrast to observations in the AI, behaviorally relevant ICES had no effects on temporal processing in the ICC or ICX, with the single exception of shorter latencies in the ICC in short-deaf cats. The results suggest that independent of deafness duration passive stimulation and behavioral training differentially transform temporal processing in auditory midbrain and cortex, and primary auditory cortex emerges as a pivotal site for behaviorally driven neuronal temporal plasticity in the deaf cat.

  6. Cortical activation in the processing of passive sentences in L1 and L2: an fMRI study.

    PubMed

    Yokoyama, Satoru; Okamoto, Hideyuki; Miyamoto, Tadao; Yoshimoto, Kei; Kim, Jungho; Iwata, Kazuki; Jeong, Hyeonjeong; Uchida, Shinya; Ikuta, Naho; Sassa, Yuko; Nakamura, Wataru; Horie, Kaoru; Sato, Shigeru; Kawashima, Ryuta

    2006-04-01

    The question of whether the bilingual brain processes a first and second language (L1 and L2, respectively) differently is a central issue in many psycholinguistic and neurolinguistic studies. This study used functional magnetic resonance imaging (fMRI) to investigate whether late bilinguals process structurally complex sentences in L1 and L2 in different cortical networks. For this purpose, we directly compared brain activity during the processing of active and passive sentences in both L1 and L2. We asked 36 healthy subjects to judge whether or not a presented sentence was semantically plausible. Both L1 and L2 activated the left hemispheric language-related regions such as the left inferior frontal, superior/middle temporal, and parietal cortices. However, we found different activation patterns between L1 and L2 in the processing of passive sentences. Passive sentences elicited greater activation than their active counterparts in the left pars triangularis, the premotor area, and the superior parietal lobule in Japanese, but not in English. Furthermore, there was a significant interaction between sentence type (active versus passive) and language (Japanese versus English) in the left pars orbitalis. The results of this study indicate that late bilinguals use similar cortical regions to comprehend both L1 and L2. However, when late bilinguals are presented with structurally complex sentences, the involvement of these regions differs between L1 and L2. These results suggest that, in addition to age of L2 acquisition and L2 proficiency, differences in grammatical construction affect cortical representation during the comprehension of L1 and L2.

  7. Comparison of the Effects of Local Cryotherapy and Passive Cross-Body Stretch on Extensibility in Subjects with Posterior Shoulder Tightness

    PubMed Central

    Park, Kyue-nam; Kwon, Oh-yun; Weon, Jong-hyuck; Choung, Sung-dae; Kim, Si-hyun

    2014-01-01

    The objective was to compare the immediate effects of local cryotherapy (LC) and passive cross-body stretch on the extensibility of the posterior shoulder muscle in individuals with posterior shoulder tightness. Eighty-seven healthy subjects with a between-shoulder difference in internal rotation (IR) range of motion (ROM) greater than 10° were randomly divided into three groups: LC group, stretching group, and control group (n = 29 in each group). Subjects in the LC group received LC on infraspinatus and posterior deltoid muscles and subjects in the stretching group performed passive cross-body stretch. Stretch sensation was measured at the end range of passive IR and horizontal adduction (HA) using numerical rating scale, and the pressure pain threshold (PPT) at the infraspinatus and posterior deltoid muscles was measured using pressure algometry. Passive and active ROM of IR and HA of the glenohumeral joint were measured using an inclinometer. All measurements were performed at pre-intervention, post- intervention, and 10-min follow-up. Stretch sensation was significantly decreased and PPT was significantly increased in the LC and stretching groups at post-intervention, and these effects were maintained at 10-min follow-up, compared to the control group. Both the LC group and stretching group had a significantly greater increase in passive and active ROM of IR and HA, compared to the control group at post-intervention and 10-min follow-up. However, there were no significant differences in stretch sensation, PPT, or ROM of IR and HA between the LC group and stretching group. LC can be used to decrease the stretch sensation and increase PPT and ROM of IR and HA as much as a stretching exercise. LC could be an alternative method for increasing the restricted ROM of glenohumeral IR and HA for individuals with posterior shoulder tightness, especially for patients and sports players who have severe stretching discomfort. Key Points Local cryotherapy (LC) decreased

  8. Local Conjecturing Process in the Solving of Pattern Generalization Problem

    ERIC Educational Resources Information Center

    Sutarto; Nusantara, Toto; Subanji; Sisworo

    2016-01-01

    This aim of this study is to describe the process of local conjecturing in generalizing patterns based on Action, Process, Object, Schema (APOS) theory. The subjects were 16 grade 8 students from a junior high school. Data collection used Pattern Generalization Problem (PGP) and interviews. In the first stage, students completed PGP; in the second…

  9. Ensuring Effective Curriculum Approval Processes: A Guide for Local Senates

    ERIC Educational Resources Information Center

    Academic Senate for California Community Colleges, 2016

    2016-01-01

    Curriculum is the heart of the mission of every college. College curriculum approval processes have been established to ensure that rigorous, high quality curriculum is offered that meets the needs of students. While some concerns may exist regarding the effectiveness and efficiency of local curriculum processes, all participants in the process…

  10. Cultural Variations in Global versus Local Processing: A Developmental Perspective

    ERIC Educational Resources Information Center

    Oishi, Shigehiro; Jaswal, Vikram K.; Lillard, Angeline S.; Mizokawa, Ai; Hitokoto, Hidefumi; Tsutsui, Yoshiro

    2014-01-01

    We conducted 3 studies to explore cultural differences in global versus local processing and their developmental trajectories. In Study 1 ("N" = 363), we found that Japanese college students were less globally oriented in their processing than American or Argentine participants. We replicated this effect in Study 2 ("N" =…

  11. Wetland-based passive treatment systems for gold ore processing effluents containing residual cyanide, metals and nitrogen species.

    PubMed

    Alvarez, R; Ordóñez, A; Loredo, J; Younger, P L

    2013-10-01

    Gold extraction operations generate a variety of wastes requiring responsible disposal in compliance with current environmental regulations. During recent decades, increased emphasis has been placed on effluent control and treatment, in order to avoid the threat to the environment posed by toxic constituents. In many modern gold mining and ore processing operations, cyanide species are of most immediate concern. Given that natural degradation processes are known to reduce the toxicity of cyanide over time, trials have been made at laboratory and field scales into the feasibility of using wetland-based passive systems as low-cost and environmentally friendly methods for long-term treatment of leachates from closed gold mine tailing disposal facilities. Laboratory experiments on discrete aerobic and anaerobic treatment units supported the development of design parameters for the construction of a field-scale passive system at a gold mine site in northern Spain. An in situ pilot-scale wetland treatment system was designed, constructed and monitored over a nine-month period. Overall, the results suggest that compost-based constructed wetlands are capable of detoxifying cyanidation effluents, removing about 21.6% of dissolved cyanide and 98% of Cu, as well as nitrite and nitrate. Wetland-based passive systems can therefore be considered as a viable technology for removal of residual concentrations of cyanide from leachates emanating from closed gold mine tailing disposal facilities.

  12. Digital Processing of Passive Ka-Band Microwave Images for Sea-Ice Classification

    DTIC Science & Technology

    1984-05-01

    Development Activity »’ NSTL, Mississippi 39529 Foreword Field trials of an airborne passive-microwave imaging system (MICRAD) in April 1976 demonstrated...Ross Williams). Engineering field tests of the KRMS were completed in December 1982. First use of the KRMS in support of an Arctic research...brightness temperature 6 Numerical approach to image classification 11 Field data 13 Histograms 14 Training regions 14 Open water 14 Old ice 15 First

  13. Snap Your Fingers! An ERP/sLORETA Study Investigating Implicit Processing of Self- vs. Other-Related Movement Sounds Using the Passive Oddball Paradigm.

    PubMed

    Justen, Christoph; Herbert, Cornelia

    2016-01-01

    So far, neurophysiological studies have investigated implicit and explicit self-related processing particularly for self-related stimuli such as the own face or name. The present study extends previous research to the implicit processing of self-related movement sounds and explores their spatio-temporal dynamics. Event-related potentials (ERPs) were assessed while participants (N = 12 healthy subjects) listened passively to previously recorded self- and other-related finger snapping sounds, presented either as deviants or standards during an oddball paradigm. Passive listening to low (500 Hz) and high (1000 Hz) pure tones served as additional control. For self- vs. other-related finger snapping sounds, analysis of ERPs revealed significant differences in the time windows of the N2a/MMN and P3. An subsequent source localization analysis with standardized low-resolution brain electromagnetic tomography (sLORETA) revealed increased cortical activation in distinct motor areas such as the supplementary motor area (SMA) in the N2a/mismatch negativity (MMN) as well as the P3 time window during processing of self- and other-related finger snapping sounds. In contrast, brain regions associated with self-related processing [e.g., right anterior/posterior cingulate cortex (ACC/PPC)] as well as the right inferior parietal lobule (IPL) showed increased activation particularly during processing of self- vs. other-related finger snapping sounds in the time windows of the N2a/MMN (ACC/PCC) or the P3 (IPL). None of these brain regions showed enhanced activation while listening passively to low (500 Hz) and high (1000 Hz) pure tones. Taken together, the current results indicate (1) a specific role of motor regions such as SMA during auditory processing of movement-related information, regardless of whether this information is self- or other-related, (2) activation of neural sources such as the ACC/PCC and the IPL during implicit processing of self-related movement stimuli, and (3

  14. Snap Your Fingers! An ERP/sLORETA Study Investigating Implicit Processing of Self- vs. Other-Related Movement Sounds Using the Passive Oddball Paradigm

    PubMed Central

    Justen, Christoph; Herbert, Cornelia

    2016-01-01

    So far, neurophysiological studies have investigated implicit and explicit self-related processing particularly for self-related stimuli such as the own face or name. The present study extends previous research to the implicit processing of self-related movement sounds and explores their spatio-temporal dynamics. Event-related potentials (ERPs) were assessed while participants (N = 12 healthy subjects) listened passively to previously recorded self- and other-related finger snapping sounds, presented either as deviants or standards during an oddball paradigm. Passive listening to low (500 Hz) and high (1000 Hz) pure tones served as additional control. For self- vs. other-related finger snapping sounds, analysis of ERPs revealed significant differences in the time windows of the N2a/MMN and P3. An subsequent source localization analysis with standardized low-resolution brain electromagnetic tomography (sLORETA) revealed increased cortical activation in distinct motor areas such as the supplementary motor area (SMA) in the N2a/mismatch negativity (MMN) as well as the P3 time window during processing of self- and other-related finger snapping sounds. In contrast, brain regions associated with self-related processing [e.g., right anterior/posterior cingulate cortex (ACC/PPC)] as well as the right inferior parietal lobule (IPL) showed increased activation particularly during processing of self- vs. other-related finger snapping sounds in the time windows of the N2a/MMN (ACC/PCC) or the P3 (IPL). None of these brain regions showed enhanced activation while listening passively to low (500 Hz) and high (1000 Hz) pure tones. Taken together, the current results indicate (1) a specific role of motor regions such as SMA during auditory processing of movement-related information, regardless of whether this information is self- or other-related, (2) activation of neural sources such as the ACC/PCC and the IPL during implicit processing of self-related movement stimuli, and (3

  15. A Model Using Local Weather Data to Determine the Effective Sampling Volume for PCB Congeners Collected on Passive Air Samplers

    PubMed Central

    2016-01-01

    We have developed and evaluated a mathematical model to determine the effective sampling volumes (Veff) of PCBs and similar compounds captured using polyurethane foam passive air samplers (PUF–PAS). We account for the variability in wind speed, air temperature, and equilibrium partitioning over the course of the deployment of the samplers. The model, provided as an annotated Matlab script, predicts the Veff as a function of physical-chemical properties of each compound and meteorology from the closest Integrated Surface Database (ISD) data set obtained through NOAA’s National Centers for Environmental Information (NCEI). The model was developed to be user-friendly, only requiring basic Matlab knowledge. To illustrate the effectiveness of the model, we evaluated three independent data sets of airborne PCBs simultaneously collected using passive and active samplers: at sites in Chicago, Lancaster, UK, and Toronto, Canada. The model provides Veff values comparable to those using depuration compounds and calibration against active samplers, yielding an average congener specific concentration method ratio (active/passive) of 1.1 ± 1.2. We applied the model to PUF–PAS samples collected in Chicago and show that previous methods can underestimate concentrations of PCBs by up to 40%, especially for long deployments, deployments conducted under warming conditions, and compounds with log Koa values less than 8. PMID:26963482

  16. Influences of consolidation processes on local paper structure

    NASA Astrophysics Data System (ADS)

    Sung, Yongjoo

    The accurate measurement of the structural parameters such as thickness, grammage, apparent density and surface topography, and the proper evaluation of the variation of each parameter, are very important not only for predicting the end use properties of the paper, but also for diagnosing the pa permaking processes. The difficulty of the measurement of thickness at fine scale ˜1 mm has been an impediment to the understanding of local paper structure. To address this problem, a twin laser profilometer instrument (TLP) for non-contacting measurement of local thickness and surface topography was developed, characterized and calibrated in this work. The fundamental relationships between structural parameters were reexamined with various handsheet samples. The effects of wet pressing on the local paper structure were evaluated using laboratory static press and commercial press felts. The different press pressure had no significant influence on the local density variation of the handsheet samples. The influences of felts on the surface topography were also successfully observed. The different densification effects of soft nip and hard nip calendering processes were evaluated by direct comparison of structural parameters before and after processing. The much higher selective reduction in local thickness (larger reduction for the thicker area) by the hard nip calendering process resulted in different relationships between structural parameters. The various periodic variations in the paper structure were also detected, analyzed and identified. The effects of different forming elements such as the conventional foil system and the velocity induced drainage (VID) system on the paper structure and end use properties were evaluated with pilot machine trials and commercial product produced using different forming elements. Generally, the VID samples showed better formation, less two sidedness in the fine distribution through thickness direction, and less densification during

  17. Digital image processing for the early localization of cancer

    NASA Astrophysics Data System (ADS)

    Kelmar, Cheryl M.

    1991-06-01

    The prognosis for cancer patients becomes much better if a tumor is diagnosed, localized and treated early, in a precancerous stage. The difficulty lies in the localization of cancerous tumors. Carcinoma in situ (CIS) refers to a tumor which is approximately 100 microns thick and one which has not penetrated through the epithelium wall or become invasive (2). A tumor of this size cannot be detected by existing techniques such as x-ray, computer tomography, magnetic resonance imaging, nuclear medicine or conventional endoscopy under white-light illumination. However, these tumors can be localized and destroyed by photodynamic diagnosis and therapy. This research shows that digital image processing and the technique of digital image ratioing contribute to photodynamic diagnosis and the early localization of cancer. A software package has been developed as a result of this research. The software package quantifies the usefulness of digital image processing for tumor localization and detectability. System parameters such as the endoscope distance and angle variations, tumor size and tumor concentration, sensitivity and specificity of the system have been tested and quantified.

  18. Processing and fusion for human body terahertz dual-band passive image

    NASA Astrophysics Data System (ADS)

    Tian, Li; Shen, Yanchun; Jin, Weiqi; Zhao, Guozhong; Cai, Yi

    2016-11-01

    Compared with microwave, THz has higher resolution, and compared with infrared, THz has better penetrability. Human body radiate THz also, its photon energy is low, it is harmless to human body. So THz has great potential applications in the body searching system. Dual-band images may contain different information for the same scene, so THz dual-band imaging have been a significant research subject of THz technology. Base on the dual-band THz passive imaging system which is composed of a 94GHz and a 250GHz cell detector, this paper researched the preprocessing and fusion algorithm for THz dual-band images. Firstly, THz images have such problems: large noise, low SNR, low contrast, low details. Secondly, the stability problem of the optical mechanical scanning system makes the images less repetitive, obvious stripes and low definition. Aiming at these situations, this paper used the BM3D de-noising algorithm to filter noise and correct the scanning problem. Furthermore, translation, rotation and scaling exist between the two images, after registered by the intensity-base registration algorithm, and enhanced by the adaptive histogram equalization algorithm, the images are fused by image fusion algorithm based on wavelet. This effectively reduced the image noise, scan distortion and matching error, improved the details, enhanced the contrast. It is helpful to improve the detection efficiency of hidden objects too. Method in this paper has a substantial effect for improving the dual-band THz passive imaging system's performance and promoting technology practical.

  19. Morphology in autism spectrum disorders: local processing bias and language.

    PubMed

    Vulchanova, Mila; Talcott, Joel B; Vulchanov, Valentin; Stankova, Margarita; Eshuis, Hendrik

    2012-01-01

    We conducted a detailed study of a case of linguistic talent in the context of autism spectrum disorder, specifically Asperger syndrome. I.A. displays language strengths at the level of morphology and syntax. Yet, despite this grammar advantage, processing of figurative language and inferencing based on context presents a problem for him. The morphology advantage for I.A. is consistent with the weak central coherence (WCC) account of autism. From this account, the presence of a local processing bias is evident in the ways in which autistic individuals solve common problems, such as assessing similarities between objects and finding common patterns, and may therefore provide an advantage in some cognitive tasks compared to typical individuals. We extend the WCC account to language and provide evidence for a connection between the local processing bias and the acquisition of morphology and grammar.

  20. Design of an HF-Band RFID System with Multiple Readers and Passive Tags for Indoor Mobile Robot Self-Localization

    PubMed Central

    Mi, Jian; Takahashi, Yasutake

    2016-01-01

    Radio frequency identification (RFID) technology has already been explored for efficient self-localization of indoor mobile robots. A mobile robot equipped with RFID readers detects passive RFID tags installed on the floor in order to locate itself. The Monte-Carlo localization (MCL) method enables the localization of a mobile robot equipped with an RFID system with reasonable accuracy, sufficient robustness and low computational cost. The arrangements of RFID readers and tags and the size of antennas are important design parameters for realizing accurate and robust self-localization using a low-cost RFID system. The design of a likelihood model of RFID tag detection is also crucial for the accurate self-localization. This paper presents a novel design and arrangement of RFID readers and tags for indoor mobile robot self-localization. First, by considering small-sized and large-sized antennas of an RFID reader, we show how the design of the likelihood model affects the accuracy of self-localization. We also design a novel likelihood model by taking into consideration the characteristics of the communication range of an RFID system with a large antenna. Second, we propose a novel arrangement of RFID tags with eight RFID readers, which results in the RFID system configuration requiring much fewer readers and tags while retaining reasonable accuracy of self-localization. We verify the performances of MCL-based self-localization realized using the high-frequency (HF)-band RFID system with eight RFID readers and a lower density of RFID tags installed on the floor based on MCL in simulated and real environments. The results of simulations and real environment experiments demonstrate that our proposed low-cost HF-band RFID system realizes accurate and robust self-localization of an indoor mobile robot. PMID:27483279

  1. Design of an HF-Band RFID System with Multiple Readers and Passive Tags for Indoor Mobile Robot Self-Localization.

    PubMed

    Mi, Jian; Takahashi, Yasutake

    2016-07-29

    Radio frequency identification (RFID) technology has already been explored for efficient self-localization of indoor mobile robots. A mobile robot equipped with RFID readers detects passive RFID tags installed on the floor in order to locate itself. The Monte-Carlo localization (MCL) method enables the localization of a mobile robot equipped with an RFID system with reasonable accuracy, sufficient robustness and low computational cost. The arrangements of RFID readers and tags and the size of antennas are important design parameters for realizing accurate and robust self-localization using a low-cost RFID system. The design of a likelihood model of RFID tag detection is also crucial for the accurate self-localization. This paper presents a novel design and arrangement of RFID readers and tags for indoor mobile robot self-localization. First, by considering small-sized and large-sized antennas of an RFID reader, we show how the design of the likelihood model affects the accuracy of self-localization. We also design a novel likelihood model by taking into consideration the characteristics of the communication range of an RFID system with a large antenna. Second, we propose a novel arrangement of RFID tags with eight RFID readers, which results in the RFID system configuration requiring much fewer readers and tags while retaining reasonable accuracy of self-localization. We verify the performances of MCL-based self-localization realized using the high-frequency (HF)-band RFID system with eight RFID readers and a lower density of RFID tags installed on the floor based on MCL in simulated and real environments. The results of simulations and real environment experiments demonstrate that our proposed low-cost HF-band RFID system realizes accurate and robust self-localization of an indoor mobile robot.

  2. Method for localizing and isolating an errant process step

    DOEpatents

    Tobin, Jr., Kenneth W.; Karnowski, Thomas P.; Ferrell, Regina K.

    2003-01-01

    A method for localizing and isolating an errant process includes the steps of retrieving from a defect image database a selection of images each image having image content similar to image content extracted from a query image depicting a defect, each image in the selection having corresponding defect characterization data. A conditional probability distribution of the defect having occurred in a particular process step is derived from the defect characterization data. A process step as a highest probable source of the defect according to the derived conditional probability distribution is then identified. A method for process step defect identification includes the steps of characterizing anomalies in a product, the anomalies detected by an imaging system. A query image of a product defect is then acquired. A particular characterized anomaly is then correlated with the query image. An errant process step is then associated with the correlated image.

  3. The Effect of Active versus Passive Recovery Periods during High Intensity Intermittent Exercise on Local Tissue Oxygenation in 18 – 30 Year Old Sedentary Men

    PubMed Central

    Kerhervé, Hugo A.; Askew, Christopher D.; Solomon, Colin

    2016-01-01

    Purpose High intensity interval training (HIIT) has been proposed as a time-efficient format of exercise to reduce the chronic disease burden associated with sedentary behaviour. Changes in oxygen utilisation at the local tissue level during an acute session of HIIT could be the primary stimulus for the health benefits associated with this format of exercise. The recovery periods of HIIT effect the physiological responses that occur during the session. It was hypothesised that in sedentary individuals, local and systemic oxygen utilisation would be higher during HIIT interspersed with active recovery periods, when compared to passive recovery periods. Methods Twelve sedentary males (mean ± SD; age 23 ± 3 yr) completed three conditions on a cycle ergometer: 1) HIIT with passive recovery periods between four bouts (HIITPASS) 2) HIIT with active recovery periods between four bouts (HIITACT) 3) HIITACT with four HIIT bouts replaced with passive periods (REC). Deoxygenated haemoglobin (HHb) in the vastus lateralis (VL) and gastrocnemius (GN) muscles and the pre-frontal cortex (FH), oxygen consumption (VO2), power output and heart rate (HR) were measured continuously during the three conditions. Results There was a significant increase in HHb at VL during bouts 2 (p = 0.017), 3 (p = 0.035) and 4 (p = 0.035) in HIITACT, compared to HIITPASS. Mean power output was significantly lower in HIITACT, compared to HIITPASS (p < 0.001). There was a significant main effect for site in both HIITPASS (p = 0.029) and HIITACT (p = 0.005). There were no significant differences in VO2 and HR between HIITPASS and HIITACT. Conclusions The increase in HHb at VL and the lower mean power output during HIITACT could indicate that a higher level of deoxygenation contributes to decreased mechanical power in sedentary participants. The significant differences in HHb between sites indicates the specificity of oxygen utilisation. PMID:27677081

  4. Rapid method for design and fabrication of passive micromixers in microfluidic devices using a direct-printing process.

    PubMed

    Liu, Ai-Lin; He, Feng-yun; Wang, Kang; Zhou, Ting; Lu, Yu; Xia, Xing-hua

    2005-09-01

    We developed a facile and rapid one-step technique for design and fabrication of passive micromixers in microfluidic devices using a direct-printing process. A laser printing mechanism was dexterously adopted to pattern the microchannels with different gray levels using vector graphic software. With the present method, periodically ordered specific bas-relief microstructures can be easily fabricated on transparencies by a simple printing process. The size and shape of the resultant microstructures are determined by the gray level of the graphic software and the resolution of the laser printer. Patterns of specific bas-relief microstructures on the floor of a channel act as obstacles in the flow path for advection mixing, which can be used as efficient mixing elements. The mixing effect of the resultant micromixer in microfluidic devices was evaluated using CCD fluorescence spectroscopy. We found that the mixing performance depends strongly on the gray level values. Under optimal conditions, fast passive mixing with our periodic ordered patterns in microfluidic devices has been achieved at the very early stages of the laminar flow. In addition, fabrication of micromixers using the present versatile technique requires less than an hour. The present method is promising for fabrication of micromixers in microfluidic devices at low cost and without complicated devices and environment, providing a simple solution to mixing problems in the micro-total-analysis-systems field.

  5. Exciton localization in solution-processed organolead trihalide perovskites

    PubMed Central

    He, Haiping; Yu, Qianqian; Li, Hui; Li, Jing; Si, Junjie; Jin, Yizheng; Wang, Nana; Wang, Jianpu; He, Jingwen; Wang, Xinke; Zhang, Yan; Ye, Zhizhen

    2016-01-01

    Organolead trihalide perovskites have attracted great attention due to the stunning advances in both photovoltaic and light-emitting devices. However, the photophysical properties, especially the recombination dynamics of photogenerated carriers, of this class of materials are controversial. Here we report that under an excitation level close to the working regime of solar cells, the recombination of photogenerated carriers in solution-processed methylammonium–lead–halide films is dominated by excitons weakly localized in band tail states. This scenario is evidenced by experiments of spectral-dependent luminescence decay, excitation density-dependent luminescence and frequency-dependent terahertz photoconductivity. The exciton localization effect is found to be general for several solution-processed hybrid perovskite films prepared by different methods. Our results provide insights into the charge transport and recombination mechanism in perovskite films and help to unravel their potential for high-performance optoelectronic devices. PMID:26996605

  6. Exciton localization in solution-processed organolead trihalide perovskites

    NASA Astrophysics Data System (ADS)

    He, Haiping; Yu, Qianqian; Li, Hui; Li, Jing; Si, Junjie; Jin, Yizheng; Wang, Nana; Wang, Jianpu; He, Jingwen; Wang, Xinke; Zhang, Yan; Ye, Zhizhen

    2016-03-01

    Organolead trihalide perovskites have attracted great attention due to the stunning advances in both photovoltaic and light-emitting devices. However, the photophysical properties, especially the recombination dynamics of photogenerated carriers, of this class of materials are controversial. Here we report that under an excitation level close to the working regime of solar cells, the recombination of photogenerated carriers in solution-processed methylammonium-lead-halide films is dominated by excitons weakly localized in band tail states. This scenario is evidenced by experiments of spectral-dependent luminescence decay, excitation density-dependent luminescence and frequency-dependent terahertz photoconductivity. The exciton localization effect is found to be general for several solution-processed hybrid perovskite films prepared by different methods. Our results provide insights into the charge transport and recombination mechanism in perovskite films and help to unravel their potential for high-performance optoelectronic devices.

  7. Processing, Assembly and Localization of a Bacillus anthracis Spore Protein

    DTIC Science & Technology

    2010-01-01

    anthracis (but not, for example, Bacillus megaterium ), a series of fine hair-like projections, also called a nap, extends from the exosporium (Aronson...3373–3378. Vary, P. S. (1994). Prime time for Bacillus megaterium . Microbiology 140, 1001–1013. Welkos, S. L., Cote, C. K., Rea, K. M. & Gibbs, P. H...Processing, assembly and localization of a Bacillus anthracis spore protein K. L. Moody,13 A. Driks,2 G. L. Rother,1 C. K. Cote,1 E. E. Brueggemann,3

  8. Modeling Structural and Mechanical Responses to Localized Erosional Processes on a Bivergent Orogenic Wedge

    NASA Astrophysics Data System (ADS)

    Marzen, R.; Morgan, J. K.

    2014-12-01

    Critical Coulomb wedge theory established that orogenic and accretionary wedges should develop self-similarly and maintain a critical taper that reflects the balance of strength of the wedge material and a basal décollement. However, a variety of geological processes can perturb that balance, forcing readjustment of the wedge. For example, glacial erosion and landsliding can concentrate erosion on a localized portion of the wedge slope, leaving that portion of the wedge with an out-of-equilibrium slope that would need to re-develop for the wedge to resume self-similar growth. We use the discrete element method to analyze how growing bivergent wedges with different cohesive strengths respond structurally and mechanically to erosional events localized along upper, middle, and lower segments of the pro-wedge. Mechanically, pro-wedge erosion results in a sudden decrease followed by a quick recovery of the mean stress and maximum shear stress throughout the pro-wedge. However, when erosion is localized in the mid- to lower portions of the pro-wedge, a zone of increased mean stress develops where the wedge is concentrating deformation to recover its taper. In contrast, when erosion is localized in the upper axial zone, there is almost no recovery of the wedge taper, reflecting the fact that the material at the top of the wedge is being carried passively in a transition zone between the pro-wedge and retro-wedge. Structurally, wedges composed of lower cohesion material recover their critical taper almost immediately through distributed deformation, while wedges of higher-cohesion material recover more slowly, and incompletely, by concentrating deformation along existing fault surfaces. As a result, localized erosional episodes can have a lasting effect on the wedge morphology when the wedge is composed of higher cohesion material.

  9. The role of local feature processing in object perception

    NASA Astrophysics Data System (ADS)

    Suh, Hyejean

    One of the outstanding questions in the study of human visual perception of objects is how local feature processing affects object perception. In this thesis, we addressed this fundamental question by examining human perceptual performance on images containing whole objects or partial images of objects (containing one, two or three features) for two perceptual tasks: detection ("something" vs. random dot noise) and classification (perception of the object category, e.g., car vs. other objects). Images were embedded in visual noise and we measured human subjects' performance in a range of noise levels close to subjects' perceptual threshold. First, we found that human detection performance increases when more object area (A) is revealed and when the noise variance (N) decreases. The contribution of these factors can be characterized as a function of Ln(A/N), which we will refer to as the Area-to-Noise ratio (ANR). When the ANR was equated in the subsequent experiments, comparison of detection performance on partial vs. whole images of objects revealed the dynamic role of local feature processing in object detection: (i) detection based on a single useful feature was better than detection based on a whole object suggesting the effectiveness of local feature processing, (ii) however, detection of a whole object did not require detection of its features and (iii) detection performance varied across features; useful features (such as eyes for faces and wheels for cars) yielded better performance than suboptimal features (such as nose and mouth for faces). This pattern of results did not significantly vary across two methods we used to select features (features based on semantic judgments and a computer algorithm), and two object categories (faces and cars). For classification, results were largely similar, except that in low ANR levels (below the level sufficient for successful detection of a whole object) classification performance was better on a single useful feature

  10. Applicability of radio astronomy techniques to the processing and interpretation of aperture synthesis passive millimetre-wave applications

    NASA Astrophysics Data System (ADS)

    Taylor, Christopher T.; Wilkinson, Peter N.; Salmon, Neil A.; Cameron, Colin D.

    2012-06-01

    This PhD programme is contributing to the development of Passive Millimetre-Wave Imagers (PMMWI) using the principles of interferometric aperture synthesis and digital signal processing. The principal applications are security screening, all-weather flight aids and earth observation. To enhance the cost-effectiveness of PMMWI systems the number of collecting elements must be minimised whilst maintaining adequate image fidelity. A wide range of techniques have been developed by the radio astronomy community for improving the fidelity of sparse interferometric array imagery. This paper brings to the attention of readers these techniques and discusses how they may be applied to imaging using software packages publicly available from the radio astronomy community. The intention of future work is to adapt these algorithms to process experimental data from a range of realistic simulations and real-world targets.

  11. Face Context Influences Local Part Processing: An ERP Study.

    PubMed

    Zhang, Hong; Sun, Yaoru; Zhao, Lun

    2017-01-01

    Perception of face parts on the basis of features is thought to be different from perception of whole faces, which is more based on configural information. Face context is also suggested to play an important role in face processing. To investigate how face context influences the early-stage perception of facial local parts, we used an oddball paradigm that tested perceptual stages of face processing rather than recognition. We recorded the event-related potentials (ERPs) elicited by whole faces and face parts presented in four conditions (upright-normal, upright-thatcherised, inverted-normal and inverted-thatcherised), as well as the ERPs elicited by non-face objects (whole houses and house parts) with corresponding conditions. The results showed that face context significantly affected the N170 with increased amplitudes and earlier peak latency for upright normal faces. Removing face context delayed the P1 latency but did not affect the P1 amplitude prominently for both upright and inverted normal faces. Across all conditions, neither the N170 nor the P1 was modulated by house context. The significant changes on the N170 and P1 components revealed that face context influences local part processing at the early stage of face processing and this context effect might be specific for face perception. We further suggested that perceptions of whole faces and face parts are functionally distinguished.

  12. The interplay between referential processing and local syntactic/semantic processing: ERPs to written Chinese discourse.

    PubMed

    Yu, Jing; Zhang, Yaxu; Boland, Julie E; Cai, Lin

    2015-02-09

    Two event-related brain potential experiments were conducted to investigate the functional interplay between discourse-level referential processing and local syntactic/semantic processing of phrases. We manipulated both the syntactic/semantic coherence of a noun phrase (NP) and the referential ambiguity of the same NP. Incoherence of the NP elicited a P600 effect in both experiments. Referential ambiguities elicited a sustained negativity (Nref) in a subset of the participants in both experiments. Crucially, among participants showing robust Nref effects to referential ambiguity in the coherent condition, Nref effects were absent when the NP was incoherent. These results provide evidence against theories in which referential processing is functionally independent of local syntactic/semantic processing of phrases. Instead, a local phrase anomaly can block aspects of referential processing concerning ambiguity.

  13. Contribution of active and passive acoustics to study oceanographic processes feeding whales in a critical habitat of the St. Lawrence Estuary

    NASA Astrophysics Data System (ADS)

    Simard, Yvan; Roy, Nathalie; Simard, Yvan; Cotté, Cédric

    2004-05-01

    The head of the main channel of the continent in eastern Canada is the site of particular oceanographic processes that are responsible for the creation of a persistent feeding ground regularly visited by baleen whales from the Atlantic for centuries. Multifrequency acoustics coupled with ADCP and hydrographic measurements has been used to map the krill and capelin aggregations in 3D and visualize their local concentration process under tidal forcing and upwelling at the channel head. The krill scattering layers, pumped into the area by the strong two-layer estuarine circulation, appear to be concentrated during flood by tidal currents forced against the slopes and upwelling, to which depth-keeping krill is reacting by swimming down. Capelin also tends to concentrate on slopes and neighboring shallows. This highly recurrent process generates rich patches that are contributing with the mean circulation to make this area the richest krill aggregation in Northwest Atlantic. This critical habitat is located in a major continental seaway. Passive acoustics techniques are explored to locate whale calls and map the use of this area in continuing months, especially by blue and fin whales, with the aim of understanding their movements to improve their protection.

  14. Contribution of active and passive acoustics to study oceanographic processes feeding whales in a critical habitat of the St. Lawrence Estuary

    NASA Astrophysics Data System (ADS)

    Simard, Yvan; Roy, Nathalie; Simard, Yvan; Cotté, Cédric

    2001-05-01

    The head of the main channel of the continent in eastern Canada is the site of particular oceanographic processes that are responsible for the creation of a persistent feeding ground regularly visited by baleen whales from the Atlantic for centuries. Multifrequency acoustics coupled with ADCP and hydrographic measurements has been used to map the krill and capelin aggregations in 3D and visualize their local concentration process under tidal forcing and upwelling at the channel head. The krill scattering layers, pumped into the area by the strong two-layer estuarine circulation, appear to be concentrated during flood by tidal currents forced against the slopes and upwelling, to which depth-keeping krill is reacting by swimming down. Capelin also tends to concentrate on slopes and neighboring shallows. This highly recurrent process generates rich patches that are contributing with the mean circulation to make this area the richest krill aggregation in Northwest Atlantic. This critical habitat is located in a major continental seaway. Passive acoustics techniques are explored to locate whale calls and map the use of this area in continuing months, especially by blue and fin whales, with the aim of understanding their movements to improve their protection.

  15. Anaerobic-ion exchange (AN-IX) process for local-scale nitrogen recovery from wastewater.

    PubMed

    Smith, Daniel P; Smith, Nathaniel T

    2015-11-01

    An anaerobic-ion exchange (AN-IX) process was developed for point-of-origin recovery of nitrogen from household wastewater. The process features upflow solids-blanket anaerobic treatment (ammonification) followed by ammonium ion exchange onto natural zeolite. The AN-IX system is configured as a series of linked upflow chambers that operate passively without energy input, and is amenable to intermittent and seasonal operation. A 57L prototype was operated for over 1.8 years treating actual wastewater under field conditions. Total nitrogen removal exceeded 96% through the first 160 days of operation and effluent ammonium nitrogen remained below detection for 300 days. Ion exchange chambers exhibited sequential NH4(+)-N breakthrough over extended operation and complete media exhaustion was approached at Day 355. The ammonium capacity of zeolite was estimated as 13.5mg NH4(+)-N per gram dry weight. AN-IX is a resilient and cost effective process for local-scale nitrogen recovery and reuse, suitable for small scale and larger systems.

  16. Array processing for RFID tag localization exploiting multi-frequency signals

    NASA Astrophysics Data System (ADS)

    Zhang, Yimin; Li, Xin; Amin, Moeness G.

    2009-05-01

    RFID is an increasingly valuable business and technology tool for electronically identifying, locating, and tracking products, assets, and personnel. As a result, precise positioning and tracking of RFID tags and readers have received considerable attention from both academic and industrial communities. Finding the position of RFID tags is considered an important task in various real-time locating systems (RTLS). As such, numerous RFID localization products have been developed for various applications. The majority of RFID positioning systems is based on the fusion of pieces of relevant information, such as the range and the direction-of-arrival (DOA). For example, trilateration can determine the tag position by using the range information of the tag estimated from three or more spatially separated reader antennas. Triangulation is another method to locate RFID tags that use the direction-of-arrival (DOA) information estimated at multiple spatially separated locations. The RFID tag positions can also be determined through hybrid techniques that combine the range and DOA information. The focus of this paper to study the design and performance of the localization of passive RFID tags using array processing techniques in a multipath environment, and exploiting multi-frequency CW signals. The latter are used to decorrelate the coherent multipath signals for effective DOA estimation and for the purpose of accurate range estimation. Accordingly, the spatial and frequency dimensionalities are fully utilized for robust and accurate positioning of RFID tags.

  17. The Impact of Number Mismatch and Passives on the Real-Time Processing of Relative Clauses

    ERIC Educational Resources Information Center

    Contemori, Carla; Marinis, Theodoros

    2014-01-01

    Language processing plays a crucial role in language development, providing the ability to assign structural representations to input strings (e.g., Fodor, 1998). In this paper we aim at contributing to the study of children's processing routines, examining the operations underlying the auditory processing of relative clauses in children…

  18. Scalable Indoor Localization via Mobile Crowdsourcing and Gaussian Process.

    PubMed

    Chang, Qiang; Li, Qun; Shi, Zesen; Chen, Wei; Wang, Weiping

    2016-03-16

    Indoor localization using Received Signal Strength Indication (RSSI) fingerprinting has been extensively studied for decades. The positioning accuracy is highly dependent on the density of the signal database. In areas without calibration data, however, this algorithm breaks down. Building and updating a dense signal database is labor intensive, expensive, and even impossible in some areas. Researchers are continually searching for better algorithms to create and update dense databases more efficiently. In this paper, we propose a scalable indoor positioning algorithm that works both in surveyed and unsurveyed areas. We first propose Minimum Inverse Distance (MID) algorithm to build a virtual database with uniformly distributed virtual Reference Points (RP). The area covered by the virtual RPs can be larger than the surveyed area. A Local Gaussian Process (LGP) is then applied to estimate the virtual RPs' RSSI values based on the crowdsourced training data. Finally, we improve the Bayesian algorithm to estimate the user's location using the virtual database. All the parameters are optimized by simulations, and the new algorithm is tested on real-case scenarios. The results show that the new algorithm improves the accuracy by 25.5% in the surveyed area, with an average positioning error below 2.2 m for 80% of the cases. Moreover, the proposed algorithm can localize the users in the neighboring unsurveyed area.

  19. Gaussian process regression for sensor networks under localization uncertainty

    USGS Publications Warehouse

    Jadaliha, M.; Xu, Yunfei; Choi, Jongeun; Johnson, N.S.; Li, Weiming

    2013-01-01

    In this paper, we formulate Gaussian process regression with observations under the localization uncertainty due to the resource-constrained sensor networks. In our formulation, effects of observations, measurement noise, localization uncertainty, and prior distributions are all correctly incorporated in the posterior predictive statistics. The analytically intractable posterior predictive statistics are proposed to be approximated by two techniques, viz., Monte Carlo sampling and Laplace's method. Such approximation techniques have been carefully tailored to our problems and their approximation error and complexity are analyzed. Simulation study demonstrates that the proposed approaches perform much better than approaches without considering the localization uncertainty properly. Finally, we have applied the proposed approaches on the experimentally collected real data from a dye concentration field over a section of a river and a temperature field of an outdoor swimming pool to provide proof of concept tests and evaluate the proposed schemes in real situations. In both simulation and experimental results, the proposed methods outperform the quick-and-dirty solutions often used in practice.

  20. Scalable Indoor Localization via Mobile Crowdsourcing and Gaussian Process

    PubMed Central

    Chang, Qiang; Li, Qun; Shi, Zesen; Chen, Wei; Wang, Weiping

    2016-01-01

    Indoor localization using Received Signal Strength Indication (RSSI) fingerprinting has been extensively studied for decades. The positioning accuracy is highly dependent on the density of the signal database. In areas without calibration data, however, this algorithm breaks down. Building and updating a dense signal database is labor intensive, expensive, and even impossible in some areas. Researchers are continually searching for better algorithms to create and update dense databases more efficiently. In this paper, we propose a scalable indoor positioning algorithm that works both in surveyed and unsurveyed areas. We first propose Minimum Inverse Distance (MID) algorithm to build a virtual database with uniformly distributed virtual Reference Points (RP). The area covered by the virtual RPs can be larger than the surveyed area. A Local Gaussian Process (LGP) is then applied to estimate the virtual RPs’ RSSI values based on the crowdsourced training data. Finally, we improve the Bayesian algorithm to estimate the user’s location using the virtual database. All the parameters are optimized by simulations, and the new algorithm is tested on real-case scenarios. The results show that the new algorithm improves the accuracy by 25.5% in the surveyed area, with an average positioning error below 2.2 m for 80% of the cases. Moreover, the proposed algorithm can localize the users in the neighboring unsurveyed area. PMID:26999139

  1. Local and Global Limits on Visual Processing in Schizophrenia

    PubMed Central

    Tibber, Marc S.; Anderson, Elaine J.; Bobin, Tracy; Carlin, Patricia; Shergill, Sukhwinder S.; Dakin, Steven C.

    2015-01-01

    Schizophrenia has been linked to impaired performance on a range of visual processing tasks (e.g. detection of coherent motion and contour detection). It has been proposed that this is due to a general inability to integrate visual information at a global level. To test this theory, we assessed the performance of people with schizophrenia on a battery of tasks designed to probe voluntary averaging in different visual domains. Twenty-three outpatients with schizophrenia (mean age: 40±8 years; 3 female) and 20 age-matched control participants (mean age 39±9 years; 3 female) performed a motion coherence task and three equivalent noise (averaging) tasks, the latter allowing independent quantification of local and global limits on visual processing of motion, orientation and size. All performance measures were indistinguishable between the two groups (ps>0.05, one-way ANCOVAs), with one exception: participants with schizophrenia pooled fewer estimates of local orientation than controls when estimating average orientation (p = 0.01, one-way ANCOVA). These data do not support the notion of a generalised visual integration deficit in schizophrenia. Instead, they suggest that distinct visual dimensions are differentially affected in schizophrenia, with a specific impairment in the integration of visual orientation information. PMID:25689281

  2. Local and global limits on visual processing in schizophrenia.

    PubMed

    Tibber, Marc S; Anderson, Elaine J; Bobin, Tracy; Carlin, Patricia; Shergill, Sukhwinder S; Dakin, Steven C

    2015-01-01

    Schizophrenia has been linked to impaired performance on a range of visual processing tasks (e.g. detection of coherent motion and contour detection). It has been proposed that this is due to a general inability to integrate visual information at a global level. To test this theory, we assessed the performance of people with schizophrenia on a battery of tasks designed to probe voluntary averaging in different visual domains. Twenty-three outpatients with schizophrenia (mean age: 40±8 years; 3 female) and 20 age-matched control participants (mean age 39±9 years; 3 female) performed a motion coherence task and three equivalent noise (averaging) tasks, the latter allowing independent quantification of local and global limits on visual processing of motion, orientation and size. All performance measures were indistinguishable between the two groups (ps>0.05, one-way ANCOVAs), with one exception: participants with schizophrenia pooled fewer estimates of local orientation than controls when estimating average orientation (p = 0.01, one-way ANCOVA). These data do not support the notion of a generalised visual integration deficit in schizophrenia. Instead, they suggest that distinct visual dimensions are differentially affected in schizophrenia, with a specific impairment in the integration of visual orientation information.

  3. Three-dimensional line interpretation via local processing

    NASA Astrophysics Data System (ADS)

    Pentland, Alexander P.; Kuo, Jeff

    1990-10-01

    The interpretation of line drawings is known to be very difficult, and has a long history in vision research. However for certain restricted but important types of drawings we have been able to produce good 3-D interpretations quite efficiently using only local image-plane computations. The types of drawings we can handle are line drawings of 3-D space curves, for instance, a drawing of the 3-D path followed by a butterfly or a line drawing of a potato chip. Such line drawings are, of course, intrinsically ambiguous - there is simply not enough information in the 2-D image to arrive at a unique 3-D interpretation. Despite this difficulty, there remains the fact that for any given image all people see pretty much exactly the same 3-D interpretation (or sometimes a small number of interpretations). People, therefore, must be bringing additional knowledge or assumptions to the problem. In this paper we show that by picking the smoothest 3-D space curve that is consistent with the image data we can obtain a 3-D interpretation which is very similar to the people's interpretation. The teleological motivation for selecting the smoothest 3-D space curve is that it is the most stable 3-D interpretation, and thus in one sense the most likely 3-D interpretation. The process of computing the smoothest 3-D space curve is carried out by simple, local processing that can be implemented by a neural network.

  4. Dough, tough, cough, rough: A "fast" fMRI localizer of component processes in reading.

    PubMed

    Malins, Jeffrey G; Gumkowski, Nina; Buis, Bonnie; Molfese, Peter; Rueckl, Jay G; Frost, Stephen J; Pugh, Kenneth R; Morris, Robin; Mencl, W Einar

    2016-10-01

    In the current study, we present a novel fMRI protocol in which words, pseudowords, and other word-like stimuli are passively presented in a rapid, sequential fashion. In this "fast" localizer paradigm, items are presented in groups of four; within sets, words are related in orthographic, phonological, and/or semantic properties. We tested this protocol with a group of skilled adult readers (N=18). Analyses uncovered key regions of the reading network that were sensitive to different component processes at the group level; namely, left fusiform gyrus as well as the pars opercularis subregion of inferior frontal gyrus were sensitive to lexicality; several regions including left precentral gyrus and left supramarginal gyrus were sensitive to spelling-sound consistency; the pars triangularis subregion of inferior frontal gyrus was sensitive to semantic similarity. Additionally, in a number of key brain regions, activation in response to semantically similar words was related to individual differences in reading comprehension outside the scanner. Importantly, these findings are in line with previous investigations of the reading network, yet data were obtained using much less imaging time than comparable paradigms currently available, especially relative to the number of indices of component processes obtained. This feature, combined with the relatively simple nature of the task, renders it appropriate for groups of subjects with a wide range of reading abilities, including children with impairments.

  5. On the single sweep processing of auditory brainstem responses: click vs. chirp stimulations and active vs. passive electrodes.

    PubMed

    Corona-Strauss, Farah I; Delb, Wolfgang; Bloching, Marc; Strauss, Daniel J

    2008-01-01

    We have recently shown that click evoked auditory brainstem responses (ABRs) single sweeps can efficiently be processed by a hybrid novelty detection system. This approach allowed for the objective detection of hearing thresholds in a fraction of time of conventional schemes, making it appropriate for the efficient implementation of newborn hearing screening procedures. It is the objective of this study to evaluate whether this approach might further be improved by different stimulation paradigms and electrode settings. In particular, we evaluate chirp stimulations which compensate the basilar-membrane dispersion and active electrodes which are less sensitive to movements. This is the first study which is directed to a single sweep processing of chirp evoked ABRs. By concentrating on transparent features and a minimum number of adjustable parameters, we present an objective comparison of click vs.chirp stimulations and active vs. passive electrodes in the ultrafast ABR detection. We show that chirp evoked brainstem responses and active electrodes might improve the single sweeps analysis of ABRs.Consequently, we conclude that a single sweep processing of ABRs for the objective determination of hearing thresholds can further be improved by the use of optimized chirp stimulations and active electrodes.

  6. Novel Surface Passivation Technique for Low-Temperature Solution-Processed Perovskite PV Cells.

    PubMed

    Tripathi, Neeti; Shirai, Yasuhiro; Yanagida, Masatoshi; Karen, Akiya; Miyano, Kenjiro

    2016-02-01

    Low-temperature solution-processed perovskite solar cells are attracting immense interest due to their ease of fabrication and potential for mass production on flexible substrates. However, the unfavorable surface properties of planar substrates often lead to large variations in perovskite crystal size and weak charge extractions at interfaces, resulting in inferior performance. Here, we report the improved performance, reproducibility, and high stability of "p-i-n" planar heterojunction perovskite solar cells. The key fabrication process is the addition of the amine-polymer poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN-P1) to a simple spin-coating process. The PFN-P1 works as a surfactant and helps promote uniform crystallization. As a result, perovskite films with PFN-P1 have a uniform distribution of grain sizes and improved open circuit voltage. Devices with PFN-P1 showed the best efficiency (13.2%), with a small standard deviation (0.40), out of 60 cells. Moreover, ∼90% of the initial efficiency was retained over more than 6 months. Additionally, devices fabricated from PFN-P1 mixed perovskite films showed higher stability under continuous operation at maximum power point over 150 h. Our results show that this approach is simple and effective for improving device performance, reproducibility, and stability by modifying perovskite properties with PFN-P1. Because of the simplicity of the fabrication process and reliable performance increase, this approach marks important progress in low-temperature solution-processed perovskite solar cells.

  7. Method of drying passivated micromachines by dewetting from a liquid-based process

    DOEpatents

    Houston, Michael R.; Howe, Roger T.; Maboudian, Roya; Srinivasan, Uthara

    2000-01-01

    A method of fabricating a micromachine includes the step of constructing a low surface energy film on the micromachine. The micromachine is then rinsed with a rinse liquid that has a high surface energy, relative to the low surface energy film, to produce a contact angle of greater than 90.degree. between the low surface energy film and the rinse liquid. This relatively large contact angle causes any rinse liquid on the micromachine to be displaced from the micromachine when the micromachine is removed from the rinse liquid. In other words, the micromachine is dried by dewetting from a liquid-based process. Thus, a separate evaporative drying step is not required, as the micromachine is removed from the liquid-based process in a dry state. The relatively large contact angle also operates to prevent attractive capillary forces between micromachine components, thereby preventing contact and adhesion between adjacent microstructure surfaces. The low surface energy film may be constructed with a fluorinated self-assembled monolayer film. The processing of the invention avoids the use of environmentally harmful, health-hazardous chemicals.

  8. Behavioral detection of passive whisker stimuli requires somatosensory cortex.

    PubMed

    Miyashita, Toshio; Feldman, Daniel E

    2013-07-01

    Rodent whisker sensation occurs both actively, as whiskers move rhythmically across objects, and in a passive mode in which externally applied deflections are sensed by static, non-moving whiskers. Passive whisker stimuli are robustly encoded in the somatosensory (S1) cortex, and provide a potentially powerful means of studying cortical processing. However, whether S1 contributes to passive sensation is debated. We developed 2 new behavioral tasks to assay passive whisker sensation in freely moving rats: Detection of unilateral whisker deflections and discrimination of right versus left whisker deflections. Stimuli were simple, simultaneous multi-whisker deflections. Local muscimol inactivation of S1 reversibly and robustly abolished sensory performance on these tasks. Thus, S1 is required for the detection and discrimination of simple stimuli by passive whiskers, in addition to its known role in active whisker sensation.

  9. Rise of dinosaurs reveals major body-size transitions are driven by passive processes of trait evolution

    PubMed Central

    Sookias, Roland B.; Butler, Richard J.; Benson, Roger B. J.

    2012-01-01

    A major macroevolutionary question concerns how long-term patterns of body-size evolution are underpinned by smaller scale processes along lineages. One outstanding long-term transition is the replacement of basal therapsids (stem-group mammals) by archosauromorphs, including dinosaurs, as the dominant large-bodied terrestrial fauna during the Triassic (approx. 252–201 million years ago). This landmark event preceded more than 150 million years of archosauromorph dominance. We analyse a new body-size dataset of more than 400 therapsid and archosauromorph species spanning the Late Permian–Middle Jurassic. Maximum-likelihood analyses indicate that Cope's rule (an active within-lineage trend of body-size increase) is extremely rare, despite conspicuous patterns of body-size turnover, and contrary to proposals that Cope's rule is central to vertebrate evolution. Instead, passive processes predominate in taxonomically and ecomorphologically more inclusive clades, with stasis common in less inclusive clades. Body-size limits are clade-dependent, suggesting intrinsic, biological factors are more important than the external environment. This clade-dependence is exemplified by maximum size of Middle–early Late Triassic archosauromorph predators exceeding that of contemporary herbivores, breaking a widely-accepted ‘rule’ that herbivore maximum size greatly exceeds carnivore maximum size. Archosauromorph and dinosaur dominance occurred via opportunistic replacement of therapsids following extinction, but were facilitated by higher archosauromorph growth rates. PMID:22298850

  10. Influence of Second Language Proficiency and Syntactic Structure Similarities on the Sensitivity and Processing of English Passive Sentence in Late Chinese-English Bilinguists: An ERP Study

    ERIC Educational Resources Information Center

    Chang, Xin; Wang, Pei

    2016-01-01

    To investigate the influence of L2 proficiency and syntactic similarity on English passive sentence processing, the present ERP study asked 40 late Chinese-English bilinguals (27 females and 13 males, mean age = 23.88) with high or intermediate L2 proficiency to read the sentences carefully and to indicate for each sentence whether or not it was…

  11. Local permeability changes, passive degassing and related gas hazard at the Baia di Levante area (Vulcano island, Italy)

    NASA Astrophysics Data System (ADS)

    Diliberto, Iole Serena; Cangemi, Marianna; Gagliano, Antonina Lisa; Inguaggiato, Salvatore; Madonia, Paolo; Pedone, Maria; Fabio Pisciotta, Antonino

    2016-04-01

    Vulcano, the southernmost island of the Aeolian archipelago (Italy), is presently characterized by active fumarolic fields located along the rim of La Fossa cone and the shoreline of the Baia di Levante beach, in the northern portion of the island.The Baia di Levante fumarolic vents are fed by a shallow hydrothermal aquifer heated by magmatic gases rising from the deep down, with a spatial distribution strongly affected by the local fracture network. These fractures are the expression of a deformation field, dominated by a northward motion to Lipari, abruptly decaying to the Vulcanello peninsula, immediately northward of the Baia di Levante beach. Variable rates of fluid transfer to the surface, following permeability changes affecting the fracture network are among the results of stress field variations over time which induce fluctuations in the pressure state of the hydrothermal system. Under these conditions, increments in hydrothermal gas flow, able to cause an increase of gas hazard, could be determined by a rearrangement of the shallow permeability distribution induced by changes in the deformation field. In this case not associated to any variation in the volcanic activity state. Since 2009 an huge gas flow increment has been noticed in some undersea vents of the Baia di Levante area, leading to increase of gas hazard in their immediate surroundings. On the contrary, the acquired data from the INGV volcanic surveillance program didn't suggest any correlated increase of the magmatic fluid component in the degassing activity.In July 2015, we carried out multi-parametric geochemical surveys in this area, based on direct (thermocouple) and indirect (thermal infrared camera and pyrometer) soil temperature, soil CO2 flux, atmospheric concentration of CO2 and H2S measurements at low elevation (one meter a.s.l.). The chemical and isotopic composition of low temperature fumarole gases was determined too.The comparison of the new data with previous surveys carried out

  12. Investigation of radio astronomy image processing techniques for use in the passive millimetre-wave security screening environment

    NASA Astrophysics Data System (ADS)

    Taylor, Christopher T.; Hutchinson, Simon; Salmon, Neil A.; Wilkinson, Peter N.; Cameron, Colin D.

    2014-06-01

    Image processing techniques can be used to improve the cost-effectiveness of future interferometric Passive MilliMetre Wave (PMMW) imagers. The implementation of such techniques will allow for a reduction in the number of collecting elements whilst ensuring adequate image fidelity is maintained. Various techniques have been developed by the radio astronomy community to enhance the imaging capability of sparse interferometric arrays. The most prominent are Multi- Frequency Synthesis (MFS) and non-linear deconvolution algorithms, such as the Maximum Entropy Method (MEM) and variations of the CLEAN algorithm. This investigation focuses on the implementation of these methods in the defacto standard for radio astronomy image processing, the Common Astronomy Software Applications (CASA) package, building upon the discussion presented in Taylor et al., SPIE 8362-0F. We describe the image conversion process into a CASA suitable format, followed by a series of simulations that exploit the highlighted deconvolution and MFS algorithms assuming far-field imagery. The primary target application used for this investigation is an outdoor security scanner for soft-sided Heavy Goods Vehicles. A quantitative analysis of the effectiveness of the aforementioned image processing techniques is presented, with thoughts on the potential cost-savings such an approach could yield. Consideration is also given to how the implementation of these techniques in CASA might be adapted to operate in a near-field target environment. This may enable a much wider usability by the imaging community outside of radio astronomy and thus would be directly relevant to portal screening security systems in the microwave and millimetre wave bands.

  13. Effect of passivation layer grown by atomic layer deposition and sputtering processes on Si quantum dot superlattice to generate high photocurrent for high-efficiency solar cells

    NASA Astrophysics Data System (ADS)

    Maksudur Rahman, Mohammad; Higo, Akio; Sekhar, Halubai; Erman Syazwan, Mohd; Hoshi, Yusuke; Usami, Noritaka; Samukawa, Seiji

    2016-03-01

    The effect of passivation films on a Si quantum dot superlattice (QDSL) was investigated to generate high photocurrent in solar-cell applications. Three types of passivation films, sputter-grown amorphous silicon carbide (a-SiC), hydrogenated a-SiC (a-SiC:H), and atomic-layer-deposited aluminum oxide (ALD-Al2O3), were used to passivate the Si QDSLs containing a stack of four 4 nm Si nanodisks (NDs) and 2 nm silicon carbide (SiC) films fabricated by neutral beam etching (NBE). Because of the high surface-to-volume ratio typically present in quantum Si-NDs formed in the top-down NBE process, there is a tendency to form larger surface dangling bonds on untreated Si-ND surfaces as well as to have short distance (<10 nm) between high-aspect-ratio nanopillars of stacked 4 nm Si-NDs/2 nm SiC films, which conventionally sputter SiC films cannot uniformly cover. Therefore, we optimized the passivation techniques with an ALD-Al2O3 film. Scanning electron microscopy (SEM) analysis helped to explain the surface morphology before and after the passivation of the QDSLs. After the completion of the passivation process, the quality of the top surface films of the QDSLs was analyzed from the surface roughness by atomic force microscopy (AFM) analysis, which revealed that ALD-Al2O3 passivated films had the smallest roughness (RMS) of 1.09 nm with respect to sputter-grown a-SiC (RMS: 1.75 nm) and a-SiC:H (RMS: 1.54 nm) films. Conductive atomic force microscopy (CAFM) revealed that ALD-Al2O3 passivation decreased the surface-leakage current as a result of proper passivation of side-wall surface defects in the QDSLs. The carrier transport characteristics were extracted from the QDSLs using the photovoltaic (PV) properties of p++/i/n+ solar cells, where the QDSLs consisted of different passivation layers acting as intermediate layers (i-layers) between the high-doping-density p++ Si (1 × 1020 cm-3) and n+ Si (1 × 1019 cm-3) substrates. High-doping-density p++ Si acted as a hole

  14. Threshold Region Performance Prediction for Adaptive Matched Field Processing Localization

    DTIC Science & Technology

    2007-11-02

    significant non-local estimation errors at low signal-to-noise ratios ( SNRs )-errors not modeled by traditional localization measures such as the Cramer...as a function of SNR , for apertures and environments of interest. Particular attention will be given to the "threshold SNR " (below which localization...performance degrades rapidly due to global estimation errors) and to the minimum SNR required to achieve acceptable range/depth localization. Initial

  15. Toxicological evaluation of some Malaysian locally processed raw food products.

    PubMed

    Sharif, R; Ghazali, A R; Rajab, N F; Haron, H; Osman, F

    2008-01-01

    Malaysian locally processed raw food products are widely used as main ingredients in local cooking. Previous studies showed that these food products have a positive correlation with the incidence of cancer. The cytotoxicity effect was evaluated using MTT assay (3-(4,5-dimetil-2-thiazolil)-2,5-diphenyl-2H-tetrazolium bromide) against Chang liver cells at 2000 microg/ml following 72 h incubation. Findings showed all methanol extracts caused a tremendous drop in the percentage of cell viability at 2000 microg/ml (shrimp paste - 41.69+/-3.36%, salted fish - 37.2+/-1.06%, dried shrimp - 40.32+/-1.8%, p<0.05). To detect DNA damage in a single cell, alkaline Comet Assay was used. None of the extracts caused DNA damage to the Chang liver cells at 62.5 microg/ml following 24 h incubation, as compared to the positive control, hydrogen peroxide (tail moment - 9.50+/-1.50; tail intensity - 30.50+/-2.50). Proximate analysis which was used for the evaluation of macronutrients in food showed that shrimp paste did not comply with the protein requirement (<25%) as in Food Act 1983. Salt was found in every sample with the highest percentage being detected in shrimp paste which exceeded 20%. Following heavy metal analysis (arsenic, cadmium, lead and mercury), arsenic was found in every sample with dried shrimps showing the highest value as compared to the other samples (6.16 mg/kg). In conclusion, several food extracts showed cytotoxic effect but did not cause DNA damage against Chang liver cells. Salt was found as the main additive and arsenic was present in every sample, which could be the probable cause of the toxicity effects observed.

  16. Fundamental studies of passivity and passivity breakdown. Final report, [September 1993--September 1994

    SciTech Connect

    Macdonald, D.D.; Urquidi-Macdonald, M.

    1994-02-21

    Purpose is to understand the mechanisms for growth and breakdown of passive films on metal and alloy surfaces in aqueous medium; a secondary goal is to devise methods for predicting localized corrosion damage in industrial systems. Tasks currently being studied are: formation of bilayer structures in passive films on metals and alloys; passivity breakdown on solid vs. liquid gallium; roles of alloying elements in passivity breakdown; electrochemical impedance spectroscopy of passive films; electronic structure of passive oxide films; photoelectrochemical impedance spectroscopy of passive films; and kinetics of localized attack.

  17. A novel local anti-colorectal cancer drug delivery system: negative lipidoid nanoparticles with a passive target via a size-dependent pattern

    NASA Astrophysics Data System (ADS)

    Ding, Weifeng; Wang, Feng; Zhang, Jianfeng; Guo, Yibing; Ju, Shaoqing; Wang, Huimin

    2013-09-01

    The nontoxic, targeted and effective delivery of nucleic acid drugs remains an important challenge for clinical development. Here, we describe a novel negative lipidoid nanoparticle delivery system, providing entrapment-based transfection agents for local delivery of siRNA to the colorectal cancer focus. The delivery system was synthesized with lipidoid material 98N12-5(1), mPEG2000-C12/C14 glyceride and cholesterol at a desired molar ratio to realize the anionic surface charge of particles, which could alleviate to a larger degree the inflammatory response and immune stimulation of the organism, embodying dramatic biocompatibility. In particular, mPEG2000-C12/C14 glyceride was selected to ameliorate the stability of the delivery system and protection of nucleic acids by extending the tail length of the carbons, crucial also to neutralize the positive charge of 98N12-5(1) to form a resultant anionic particle. In vivo experiments revealed that a particle size of 90 nm perfectly realized a passive target in a size-dependent manner and did not affect the function of the liver and kidneys by a local delivery method, enema. We clarified that the uptake of negative lipidoid nanoparticles internalized through a lipid raft endocytotic pathway with low cytotoxicity, strong biocompatibility and high efficacy. This study suggests that negative lipidoid nanoparticles with enema delivery costitute, uniquely and appropriately, a local anti-colorectal cancer nucleic acid drug delivery platform, and the application of similar modes may be feasible in other therapeutic settings.

  18. General second-order covariance of Gaussian maximum likelihood estimates applied to passive source localization in fluctuating waveguides.

    PubMed

    Bertsatos, Ioannis; Zanolin, Michele; Ratilal, Purnima; Chen, Tianrun; Makris, Nicholas C

    2010-11-01

    A method is provided for determining necessary conditions on sample size or signal to noise ratio (SNR) to obtain accurate parameter estimates from remote sensing measurements in fluctuating environments. These conditions are derived by expanding the bias and covariance of maximum likelihood estimates (MLEs) in inverse orders of sample size or SNR, where the first-order covariance term is the Cramer-Rao lower bound (CRLB). Necessary sample sizes or SNRs are determined by requiring that (i) the first-order bias and the second-order covariance are much smaller than the true parameter value and the CRLB, respectively, and (ii) the CRLB falls within desired error thresholds. An analytical expression is provided for the second-order covariance of MLEs obtained from general complex Gaussian data vectors, which can be used in many practical problems since (i) data distributions can often be assumed to be Gaussian by virtue of the central limit theorem, and (ii) it allows for both the mean and variance of the measurement to be functions of the estimation parameters. Here, conditions are derived to obtain accurate source localization estimates in a fluctuating ocean waveguide containing random internal waves, and the consequences of the loss of coherence on their accuracy are quantified.

  19. The factor of local cultural specificity and process of globalization.

    PubMed

    Rudnev, Viacheslav

    2012-12-01

    is important today. Actually, Glocalization can assist in adaptation process of harmonizing local and global needs to a way of Sustainability. Glocalization puts globalization problems down to the human scale. The age of Globalization has made the problem of cultural dialog extra actual, otherwise the Mankind has no chance to survive. The Glocalization is the process of creation of a harmony in Nature, Society and Humans system in the context of Sustainability.

  20. Deep Reactive Ion Etching (DRIE) of High Aspect Ratio SiC Microstructures using a Time-Multiplexed Etch-Passivate Process

    NASA Technical Reports Server (NTRS)

    Evans, Laura J.; Beheim, Glenn M.

    2006-01-01

    High aspect ratio silicon carbide (SiC) microstructures are needed for microengines and other harsh environment micro-electro-mechanical systems (MEMS). Previously, deep reactive ion etching (DRIE) of low aspect ratio (AR less than or = 1) deep (greater than 100 micron) trenches in SiC has been reported. However, existing DRIE processes for SiC are not well-suited for definition of high aspect ratio features because such simple etch-only processes provide insufficient control over sidewall roughness and slope. Therefore, we have investigated the use of a time-multiplexed etch-passivate (TMEP) process, which alternates etching with polymer passivation of the etch sidewalls. An optimized TMEP process was used to etch high aspect ratio (AR greater than 5) deep (less than 100 micron) trenches in 6H-SiC. Power MEMS structures (micro turbine blades) in 6H-SiC were also fabricated.

  1. Assessment of a virtual functional prototyping process for the rapid manufacture of passive-dynamic ankle-foot orthoses.

    PubMed

    Schrank, Elisa S; Hitch, Lester; Wallace, Kevin; Moore, Richard; Stanhope, Steven J

    2013-10-01

    Passive-dynamic ankle-foot orthosis (PD-AFO) bending stiffness is a key functional characteristic for achieving enhanced gait function. However, current orthosis customization methods inhibit objective premanufacture tuning of the PD-AFO bending stiffness, making optimization of orthosis function challenging. We have developed a novel virtual functional prototyping (VFP) process, which harnesses the strengths of computer aided design (CAD) model parameterization and finite element analysis, to quantitatively tune and predict the functional characteristics of a PD-AFO, which is rapidly manufactured via fused deposition modeling (FDM). The purpose of this study was to assess the VFP process for PD-AFO bending stiffness. A PD-AFO CAD model was customized for a healthy subject and tuned to four bending stiffness values via VFP. Two sets of each tuned model were fabricated via FDM using medical-grade polycarbonate (PC-ISO). Dimensional accuracy of the fabricated orthoses was excellent (average 0.51 ± 0.39 mm). Manufacturing precision ranged from 0.0 to 0.74 Nm/deg (average 0.30 ± 0.36 Nm/deg). Bending stiffness prediction accuracy was within 1 Nm/deg using the manufacturer provided PC-ISO elastic modulus (average 0.48 ± 0.35 Nm/deg). Using an experimentally derived PC-ISO elastic modulus improved the optimized bending stiffness prediction accuracy (average 0.29 ± 0.57 Nm/deg). Robustness of the derived modulus was tested by carrying out the VFP process for a disparate subject, tuning the PD-AFO model to five bending stiffness values. For this disparate subject, bending stiffness prediction accuracy was strong (average 0.20 ± 0.14 Nm/deg). Overall, the VFP process had excellent dimensional accuracy, good manufacturing precision, and strong prediction accuracy with the derived modulus. Implementing VFP as part of our PD-AFO customization and manufacturing framework, which also includes fit customization, provides a novel and powerful method to

  2. Local Risk-Minimization for Defaultable Claims with Recovery Process

    SciTech Connect

    Biagini, Francesca; Cretarola, Alessandra

    2012-06-15

    We study the local risk-minimization approach for defaultable claims with random recovery at default time, seen as payment streams on the random interval [0,{tau} Logical-And T], where T denotes the fixed time-horizon. We find the pseudo-locally risk-minimizing strategy in the case when the agent information takes into account the possibility of a default event (local risk-minimization with G-strategies) and we provide an application in the case of a corporate bond. We also discuss the problem of finding a pseudo-locally risk-minimizing strategy if we suppose the agent obtains her information only by observing the non-defaultable assets.

  3. Data Locality via Coordinated Caching for Distributed Processing

    NASA Astrophysics Data System (ADS)

    Fischer, M.; Kuehn, E.; Giffels, M.; Jung, C.

    2016-10-01

    To enable data locality, we have developed an approach of adding coordinated caches to existing compute clusters. Since the data stored locally is volatile and selected dynamically, only a fraction of local storage space is required. Our approach allows to freely select the degree at which data locality is provided. It may be used to work in conjunction with large network bandwidths, providing only highly used data to reduce peak loads. Alternatively, local storage may be scaled up to perform data analysis even with low network bandwidth. To prove the applicability of our approach, we have developed a prototype implementing all required functionality. It integrates seamlessly into batch systems, requiring practically no adjustments by users. We have now been actively using this prototype on a test cluster for HEP analyses. Specifically, it has been integral to our jet energy calibration analyses for CMS during run 2. The system has proven to be easily usable, while providing substantial performance improvements. Since confirming the applicability for our use case, we have investigated the design in a more general way. Simulations show that many infrastructure setups can benefit from our approach. For example, it may enable us to dynamically provide data locality in opportunistic cloud resources. The experience we have gained from our prototype enables us to realistically assess the feasibility for general production use.

  4. REALISTIC MODELING OF LOCAL DYNAMO PROCESSES ON THE SUN

    SciTech Connect

    Kitiashvili, I. N.; Mansour, N. N.; Wray, A. A.; Kosovichev, A. G.

    2015-08-10

    Magnetic fields are usually observed in the quiet Sun as small-scale elements that cover the entire solar surface (the “salt-and-pepper” patterns in line-of-sight magnetograms). By using 3D radiative MHD numerical simulations, we find that these fields result from a local dynamo action in the top layers of the convection zone, where extremely weak “seed” magnetic fields (e.g., from a 10{sup −6} G) can locally grow above the mean equipartition field to a stronger than 2000 G field localized in magnetic structures. Our results reveal that the magnetic flux is predominantly generated in regions of small-scale helical downflows. We find that the local dynamo action takes place mostly in a shallow, about 500 km deep, subsurface layer, from which the generated field is transported into the deeper layers by convective downdrafts. We demonstrate that the observed dominance of vertical magnetic fields at the photosphere and horizontal fields above the photosphere can be explained by small-scale magnetic loops produced by the dynamo. Such small-scale loops play an important role in the structure and dynamics of the solar atmosphere and their detection in observations is critical for understanding the local dynamo action on the Sun.

  5. Local and Global Processing: Observations from a Remote Culture

    ERIC Educational Resources Information Center

    Davidoff, Jules; Fonteneau, Elisabeth; Fagot, Joel

    2008-01-01

    In Experiment 1, a normal adult population drawn from a remote culture (Himba) in northern Namibia made similarity matches to [Navon, D. (1977). Forest before trees: The precedence of global features in visual perception. "Cognitive Psychology", 9, 353-383] hierarchical figures. The Himba showed a local bias stronger than that has been…

  6. Investigation of the surface passivation mechanism through an Ag-doped Al-rich film using a solution process

    NASA Astrophysics Data System (ADS)

    Khan, Firoz; Baek, Seong-Ho; Kim, Jae Hyun

    2015-12-01

    Electronic recombination loss is an important issue for photovoltaic (PV) devices. While it can be reduced by using a passivating layer, most of the techniques used to prepare passivating layers are either not cost effective or not applicable for device applications. Previously, it was reported that a low cost sol-gel derived Al-rich zinc oxide (ZnO:Al) film serves as an effective passivating layer for p-type silicon but is not effective for n-type silicon. Herein, we studied the elemental composition of the film and the interfacial structure of ZnO:Al:Ag/n-Si using TEM, XPS, FTIR, and SIMS analyses. The XPS analysis revealed that Ag-rich zones randomly formed in the film near the ZnO:Al:Ag//n-Si interface, which induced a positive charge at the interface. The maximal value of the effective minority carrier lifetime (τeff ~ 1581 μs) is obtained for a wafer using the ZnO:Al:Ag passivating layer with RAg/Zn = 2%. The corresponding limiting surface recombination velocity is ~16 cm s-1. The FTIR absorption area of Si-H bonds is used to calculate the hydrogen content in the film. The hydrogen content is increased with increasing Ag content up to RAg/Zn = 2% to a maximal value of 3.89 × 1022 atoms per cm3 from 3.03 × 1022 atoms per cm3 for RAg/Zn = 0%. The positive charge induced at the interface may cause band bending, which would produce an electric field that repels the minority charge carriers from the interface to the bulk of n-Si. Two basic phenomena, chemical passivation due to Si-H bonding and field effect passivation due to the charge induced at the interface, have been observed for effective passivation of the n-Si surface. An implied Voc of 688.1 mV is obtained at an illumination intensity of 1 sun.Electronic recombination loss is an important issue for photovoltaic (PV) devices. While it can be reduced by using a passivating layer, most of the techniques used to prepare passivating layers are either not cost effective or not applicable for device

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

    PubMed

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

    2014-01-01

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

  8. Fast contactless vibrating structure characterization using real time field programmable gate array-based digital signal processing: Demonstrations with a passive wireless acoustic delay line probe and vision

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

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

  9. Remote trap passivation in colloidal quantum dot bulk nano-heterojunctions and its effect in solution-processed solar cells.

    PubMed

    Rath, Arup K; Pelayo Garcia de Arquer, F; Stavrinadis, Alexandros; Lasanta, Tania; Bernechea, Maria; Diedenhofen, Silke L; Konstantatos, Gerasimos

    2014-07-16

    More-efficient charge collection and suppressed trap recombination in colloidal quantum dot (CQD) solar cells is achieved by means of a bulk nano-heterojunction (BNH) structure, in which p-type and n-type materials are blended on the nanometer scale. The improved performance of the BNH devices, compared with that of bilayer devices, is displayed in higher photocurrents and higher open-circuit voltages (resulting from a trap passivation mechanism).

  10. Visibility to discern local from nonlocal dynamic processes

    NASA Astrophysics Data System (ADS)

    Brú, A.; Gómez-Castro, D.; Nuño, J. C.

    2017-04-01

    We compare using visibility the usual Kardar-Parisi-Zhang (KPZ) universality class and a fractional Edward-Wilkinson (EWf) equation with correlated noise, which share the same kinetic roughening exponents. The KPZ universality class is described by an equation in terms of the usual derivatives, uncorrelated noise and therefore is intrinsically local. The second model includes fractional powers of the Laplace operator and correlated noise, both of which are nonlocal. From their scaling properties, one could be tempted to conclude that both dynamics belong to the same universality class, specifically, to the KPZ universality class. However, this is a wrong conclusion that calls the attention against the indiscriminate application of this approach in real systems without taking into consideration basic physical assumptions (e.g. locality). These examples reveal the necessity of finding new algorithms for detecting characteristics that remain unnoticed to classical scaling analysis, where only the two first moments of the interface distribution (mean and variance) are used to classify the dynamics. We show that visibility and, in particular, the kinetic roughening exponents of the visibility interface, are able to distinguish between these two dynamics which are confused by standard techniques.

  11. Global Impacts of the Bologna Process: International Perspectives, Local Particularities

    ERIC Educational Resources Information Center

    Zmas, Aristotelis

    2015-01-01

    The paper examines the transfer of the Bologna Process (BP) outside Europe, focusing on its "external dimension" and dynamics in global settings. It argues that the BP impacts on the internationalisation activities of universities, especially with regard to cross-border transparency of qualifications, transnational improvement of quality…

  12. Measure Guideline: Passive Vents

    SciTech Connect

    Berger, David; Neri, Robin

    2016-02-05

    This document addresses the use of passive vents as a source of outdoor air in multifamily buildings. The challenges associated with implementing passive vents and the factors affecting performance are outlined. A comprehensive design methodology and quantified performance metrics are provided. Two hypothetical design examples are provided to illustrate the process. This document is intended to be useful to designers, decision-makers, and contractors implementing passive ventilation strategies. It is also intended to be a resource for those responsible for setting high-performance building program requirements, especially pertaining to ventilation and outdoor air. To ensure good indoor air quality, a dedicated source of outdoor air is an integral part of high-performance buildings. Presently, there is a lack of guidance pertaining to the design and installation of passive vents, resulting in poor system performance. This report details the criteria necessary for designing, constructing, and testing passive vent systems to enable them to provide consistent and reliable levels of ventilation air from outdoors.

  13. Information Processing to Maintain Localization in ASW Surveillance

    DTIC Science & Technology

    1977-07-29

    different targets. The approach is to combine, using Bayesian methods, contact do + a scenario- based parametric model for target motion. Statistical...method that makes accurate use of the observational data. ACCESSION for NTIS White Section DOC Buff Section 0 UNANNOUNCED 1 JUSTIFICATION Dist. AV’iL...97 Comparison of Processing Algorithms Using ASWIPS 103 REFERENCES 129 APPENDIX A AUXILIARY FORMULAS FOR EVALUATING GAUSSIAN A-1 INTEGRALS APPENDIX B

  14. The Influence of Local Geometric Effects on Mars Polar Processes

    NASA Technical Reports Server (NTRS)

    Hecht, M. H.

    2005-01-01

    Using simple, qualitative heat balance models, this paper addresses textures and structures that will result from the evolution of volatile layers by accretion and by ablation. Such phenomena may have global implications that are not apparent when only flat or sloped surfaces are modeled. In general, structures such as mounds or depressions formed out of volatile materials will evolve in shape such that the growth or retreat of any particular surface will be maximized. It can be shown that the local radius of curvature is proportional to the growth or retreat rate. For example, icy surfaces will tend to form facets that face the dominant sun direction. Two such cases are evaluated: a) Features associated with condensation of volatiles, include cold-trapping and redistribution, such as the concentration of frost around the Viking 2 lander [1]. Here I will focus on textures that likely result from the formation of seasonal CO2 deposits. b) Features associated with sublimation of volatiles, such as those described by Ingersoll et. al. [2] result in textured surfaces that affect both the apparent emissivity and albedo. Similar calculations have been performed with respect to the "Swiss cheese" features on the South Polar Cap [3]. Here, I evaluate the likely sublimation rates from optimal ice scarp structures and their implications for the long-term evolution of the polar caps and formation of layered terrain.

  15. Absolute and relative pitch: Global versus local processing of chords.

    PubMed

    Ziv, Naomi; Radin, Shulamit

    2014-01-01

    Absolute pitch (AP) is the ability to identify or produce notes without any reference note. An ongoing debate exists regarding the benefits or disadvantages of AP in processing music. One of the main issues in this context is whether the categorical perception of pitch in AP possessors may interfere in processing tasks requiring relative pitch (RP). Previous studies, focusing mainly on melodic and interval perception, have obtained inconsistent results. The aim of the present study was to examine the effect of AP and RP separately, using isolated chords. Seventy-three musicians were categorized into four groups of high and low AP and RP, and were tested on two tasks: identifying chord types (Task 1), and identifying a single note within a chord (Task 2). A main effect of RP on Task 1 and an interaction between AP and RP in reaction times were found. On Task 2 main effects of AP and RP, and an interaction were found, with highest performance in participants with both high AP and RP. Results suggest that AP and RP should be regarded as two different abilities, and that AP may slow down reaction times for tasks requiring global processing.

  16. Absolute and relative pitch: Global versus local processing of chords

    PubMed Central

    Ziv, Naomi; Radin, Shulamit

    2014-01-01

    Absolute pitch (AP) is the ability to identify or produce notes without any reference note. An ongoing debate exists regarding the benefits or disadvantages of AP in processing music. One of the main issues in this context is whether the categorical perception of pitch in AP possessors may interfere in processing tasks requiring relative pitch (RP). Previous studies, focusing mainly on melodic and interval perception, have obtained inconsistent results. The aim of the present study was to examine the effect of AP and RP separately, using isolated chords. Seventy-three musicians were categorized into four groups of high and low AP and RP, and were tested on two tasks: identifying chord types (Task 1), and identifying a single note within a chord (Task 2). A main effect of RP on Task 1 and an interaction between AP and RP in reaction times were found. On Task 2 main effects of AP and RP, and an interaction were found, with highest performance in participants with both high AP and RP. Results suggest that AP and RP should be regarded as two different abilities, and that AP may slow down reaction times for tasks requiring global processing. PMID:24855499

  17. Enhanced Local Processing of Dynamic Visual Information in Autism: Evidence from Speed Discrimination

    ERIC Educational Resources Information Center

    Chen, Y.; Norton, D. J.; McBain, R.; Gold, J.; Frazier, J. A.; Coyle, J. T.

    2012-01-01

    An important issue for understanding visual perception in autism concerns whether individuals with this neurodevelopmental disorder possess an advantage in processing local visual information, and if so, what is the nature of this advantage. Perception of movement speed is a visual process that relies on computation of local spatiotemporal signals…

  18. Behavioral and Physiological Findings of Gender Differences in Global-Local Visual Processing

    ERIC Educational Resources Information Center

    Roalf, David; Lowery, Natasha; Turetsky, Bruce I.

    2006-01-01

    Hemispheric asymmetries in global-local visual processing are well-established, as are gender differences in cognition. Although hemispheric asymmetry presumably underlies gender differences in cognition, the literature on gender differences in global-local processing is sparse. We employed event related brain potential (ERP) recordings during…

  19. Localization of Impaired Kinesthetic Processing Post-stroke

    PubMed Central

    Kenzie, Jeffrey M.; Semrau, Jennifer A.; Findlater, Sonja E.; Yu, Amy Y.; Desai, Jamsheed A.; Herter, Troy M.; Hill, Michael D.; Scott, Stephen H.; Dukelow, Sean P.

    2016-01-01

    Kinesthesia is our sense of limb motion, and allows us to gauge the speed, direction, and amplitude of our movements. Over half of stroke survivors have significant impairments in kinesthesia, which leads to greatly reduced recovery and function in everyday activities. Despite the high reported incidence of kinesthetic deficits after stroke, very little is known about how damage beyond just primary somatosensory areas affects kinesthesia. Stroke provides an ideal model to examine structure-function relationships specific to kinesthetic processing, by comparing lesion location with behavioral impairment. To examine this relationship, we performed voxel-based lesion-symptom mapping and statistical region of interest analyses on a large sample of sub-acute stroke subjects (N = 142) and compared kinesthetic performance with stroke lesion location. Subjects with first unilateral, ischemic stroke underwent neuroimaging and a comprehensive robotic kinesthetic assessment (~9 days post-stroke). The robotic exoskeleton measured subjects' ability to perform a kinesthetic mirror-matching task of the upper limbs without vision. The robot moved the stroke-affected arm and subjects' mirror-matched the movement with the unaffected arm. We found that lesions both within and outside primary somatosensory cortex were associated with significant kinesthetic impairments. Further, sub-components of kinesthesia were associated with different lesion locations. Impairments in speed perception were primarily associated with lesions to the right post-central and supramarginal gyri whereas impairments in amplitude of movement perception were primarily associated with lesions in the right pre-central gyrus, anterior insula, and superior temporal gyrus. Impairments in perception of movement direction were associated with lesions to bilateral post-central and supramarginal gyri, right superior temporal gyrus and parietal operculum. All measures of impairment shared a common association with

  20. Local muscular fatigue and attentional processes in a fencing task.

    PubMed

    Devienne, M F; Audiffren, M; Ripoll, H; Stein, J F

    2000-02-01

    Study of the effects of brief exercise on mental processes by Tomporowski and Ellis (1986) has shown that moderate muscular tension improves cognitive performance while low or high tension does not. Improvements in performance induced by exercise are commonly associated with increase in arousal, while impairments are generally attributed to the effects of muscular or central fatigue. To test two hypotheses, that (1) submaximal muscular exercise would decrease premotor time and increase would increase the attentional and preparatory effects observed in premotor time 9 men, aged 20 to 30 years, performed an isometric test at 50% of their maximum voluntary contraction between blocks of a 3-choice reaction-time fencing task. Analysis showed (1) physical exercise did not improve postexercise premotor time, (2) muscular fatigue induced by isometric contractions did not increase motor time, (3) there was no effect of exercise on attentional and preparatory processes involved in the postexercise choice-RT task. The invalidation of hypotheses was mainly explained by disparity in directional effects across subjects and by use of an exercise that was not really fatiguing.

  1. Physically secured orthogonal frequency division multiplexing-passive optical network employing noise-based encryption and signal recovery process

    NASA Astrophysics Data System (ADS)

    Jin, Wei; Zhang, Chongfu; Yuan, Weicheng

    2016-02-01

    We propose a physically enhanced secure scheme for direct detection-orthogonal frequency division multiplexing-passive optical network (DD-OFDM-PON) and long reach coherent detection-orthogonal frequency division multiplexing-passive optical network (LRCO-OFDM-PON), by employing noise-based encryption and channel/phase estimation. The noise data generated by chaos mapping are used to substitute training sequences in preamble to realize channel estimation and frame synchronization, and also to be embedded on variable number of key-selected randomly spaced pilot subcarriers to implement phase estimation. Consequently, the information used for signal recovery is totally hidden as unpredictable noise information in OFDM frames to mask useful information and to prevent illegal users from correctly realizing OFDM demodulation, and thereby enhancing resistance to attackers. The levels of illegal-decryption complexity and implementation complexity are theoretically discussed. Through extensive simulations, the performances of the proposed channel/phase estimation and the security introduced by encrypted pilot carriers have been investigated in both DD-OFDM and LRCO-OFDM systems. In addition, in the proposed secure DD-OFDM/LRCO-OFDM PON models, both legal and illegal receiving scenarios have been considered. These results show that, by utilizing the proposed scheme, the resistance to attackers can be significantly enhanced in DD-OFDM-PON and LRCO-OFDM-PON systems without performance degradations.

  2. The effect of global versus local processing styles on assimilation versus contrast in social judgment.

    PubMed

    Förster, Jens; Liberman, Nira; Kuschel, Stefanie

    2008-04-01

    The authors propose a global/local processing style model (GLOMO) for assimilation and contrast effects in social judgment. GLOMO is based on Schwarz and Bless' (1992, 2007) inclusion-exclusion model, which suggests that when information is included into a category, assimilation occurs, whereas when information is excluded from a category, contrast occurs. According to GLOMO, inclusion versus exclusion should be influenced by whether people process information globally or locally. In 5 experiments, using both disambiguation and social comparison, the authors induced local versus global processing through perceptual tasks and time perspective and showed that global processing produced assimilation, whereas local processing produced contrast. The experiments showed that processing styles elicited in one task can carry over to other tasks and influence social judgments. Furthermore, they found that hemisphere activation and accessibility of judgment-consistent knowledge partially mediated these effects. Implications for current and classic models of social judgment are discussed.

  3. Gaussian Process Regression Plus Method for Localization Reliability Improvement.

    PubMed

    Liu, Kehan; Meng, Zhaopeng; Own, Chung-Ming

    2016-07-29

    Location data are among the most widely used context data in context-aware and ubiquitous computing applications. Many systems with distinct deployment costs and positioning accuracies have been developed over the past decade for indoor positioning. The most useful method is focused on the received signal strength and provides a set of signal transmission access points. However, compiling a manual measuring Received Signal Strength (RSS) fingerprint database involves high costs and thus is impractical in an online prediction environment. The system used in this study relied on the Gaussian process method, which is a nonparametric model that can be characterized completely by using the mean function and the covariance matrix. In addition, the Naive Bayes method was used to verify and simplify the computation of precise predictions. The authors conducted several experiments on simulated and real environments at Tianjin University. The experiments examined distinct data size, different kernels, and accuracy. The results showed that the proposed method not only can retain positioning accuracy but also can save computation time in location predictions.

  4. Gaussian Process Regression Plus Method for Localization Reliability Improvement

    PubMed Central

    Liu, Kehan; Meng, Zhaopeng; Own, Chung-Ming

    2016-01-01

    Location data are among the most widely used context data in context-aware and ubiquitous computing applications. Many systems with distinct deployment costs and positioning accuracies have been developed over the past decade for indoor positioning. The most useful method is focused on the received signal strength and provides a set of signal transmission access points. However, compiling a manual measuring Received Signal Strength (RSS) fingerprint database involves high costs and thus is impractical in an online prediction environment. The system used in this study relied on the Gaussian process method, which is a nonparametric model that can be characterized completely by using the mean function and the covariance matrix. In addition, the Naive Bayes method was used to verify and simplify the computation of precise predictions. The authors conducted several experiments on simulated and real environments at Tianjin University. The experiments examined distinct data size, different kernels, and accuracy. The results showed that the proposed method not only can retain positioning accuracy but also can save computation time in location predictions. PMID:27483276

  5. Dynamic processes and their influence on the transformation of the passive admixture in the sea of Azov

    NASA Astrophysics Data System (ADS)

    Ivanov, V. A.; Cherkesov, L. V.; Shul'ga, T. Ya.

    2014-07-01

    In this model, we apply a nonlinear three-dimensional sigma-coordinate model to study the waves and currents in the Sea of Azov generated by different fields of wind forcing: a constant wind, a quickly varying real wind obtained using the data of reanalysis applying the SKIRON model, and the wind resulting from their combined forcing. This mathematical model was also applied to study the transformation of the passive admixture appearing under the influence of wind fields in the Sea of Azov considered here. We compared the results of numerical calculations with the field data obtained under the wind forcing at a number of hydrological stations. We found the regularities of the water transport driven by onshore and offshore winds, the velocities of the currents, and the characteristics of the evolution of polluted regions at different depths as functions of the nonstationary wind intensity and the velocities of the stationary currents.

  6. Managed Moves: School and Local Authority Staff Perceptions of Processes, Success and Challenges

    ERIC Educational Resources Information Center

    Bagley, Christopher; Hallam, Susan

    2015-01-01

    The current research aimed to increase understanding of the processes of managed moves for children at risk of exclusion from school, particularly exploring what contributed to success and the nature of the challenges experienced. The study was conducted in one English local authority where 11 school staff and 5 local authority staff were…

  7. The Development of Global and Local Processing: A Comparison of Children to Adults

    ERIC Educational Resources Information Center

    Peterson, Eric; Peterson, Robin L.

    2014-01-01

    In light of the adult model of a hemispheric asymmetry of global and local processing, we compared children (M [subscript age] = 8.4 years) to adults in a global-local reaction time (RT) paradigm. Hierarchical designs (large shapes made of small shapes) were presented randomly to each visual field, and participants were instructed to identify…

  8. Adaptation to leftward-shifting prisms enhances local processing in healthy individuals.

    PubMed

    Reed, Scott A; Dassonville, Paul

    2014-04-01

    In healthy individuals, adaptation to left-shifting prisms has been shown to simulate the symptoms of hemispatial neglect, including a reduction in global processing that approximates the local bias observed in neglect patients. The current study tested whether leftward prism adaptation can more specifically enhance local processing abilities. In three experiments, the impact of local and global processing was assessed through tasks that measure susceptibility to illusions that are known to be driven by local or global contextual effects. Susceptibility to the rod-and-frame illusion - an illusion disproportionately driven by both local and global effects depending on frame size - was measured before and after adaptation to left- and right-shifting prisms. A significant increase in rod-and-frame susceptibility was found for the left-shifting prism group, suggesting that adaptation caused an increase in local processing effects. The results of a second experiment confirmed that leftward prism adaptation enhances local processing, as assessed with susceptibility to the simultaneous-tilt illusion. A final experiment employed a more specific measure of the global effect typically associated with the rod-and-frame illusion, and found that although the global effect was somewhat diminished after leftward prism adaptation, the trend failed to reach significance (p=.078). Rightward prism adaptation had no significant effects on performance in any of the experiments. Combined, these findings indicate that leftward prism adaptation in healthy individuals can simulate the local processing bias of neglect patients primarily through an increased sensitivity to local visual cues, and confirm that prism adaptation not only modulates lateral shifts of attention, but also prompts shifts from one level of processing to another.

  9. Adaptation to Leftward-shifting Prisms Enhances Local Processing in Healthy Individuals

    PubMed Central

    Reed, Scott A.; Dassonville, Paul

    2014-01-01

    In healthy individuals, adaptation to left-shifting prisms has been shown to simulate the symptoms of hemispatial neglect, including a reduction in global processing that approximates the local bias observed in neglect patients. The current study tested whether leftward prism adaptation can more specifically enhance local processing abilities. In three experiments, the impact of local and global processing was assessed through tasks that measure susceptibility to illusions that are known to be driven by local or global contextual effects. Susceptibility to the rod-and-frame illusion – an illusion disproportionately driven by both local and global effects depending on frame size – was measured before and after adaptation to left- and right-shifting prisms. A significant increase in rod-and-frame susceptibility was found for the left-shifting prism group, suggesting that adaptation caused an increase in local processing effects. The results of a second experiment confirmed that leftward prism adaptation enhances local processing, as assessed with susceptibility to the simultaneous-tilt illusion. A final experiment employed a more specific measure of the global effect typically associated with the rod-andframe illusion, and found that although the global effect was somewhat diminished after leftward prism adaptation, the trend failed to reach significance (p = .078). Rightward prism adaptation had no significant effects on performance in any of the experiments. Combined, these findings indicate that leftward prism adaptation in healthy individuals can simulate the local processing bias of neglect patients primarily through an increased sensitivity to local visual cues, and confirm that prism adaptation not only modulates lateral shifts of attention, but also prompts shifts from one level of processing to another. PMID:24560913

  10. The transmembrane transporter domain of glutamate transporters is a process tip localizer

    PubMed Central

    Hayashi, Mariko Kato; Yasui, Masato

    2015-01-01

    Glutamate transporters in the central nervous system remove glutamate released from neurons to terminate the signal. These transporters localize to astrocyte process tips approaching neuronal synapses. The mechanisms underlying the localization of glutamate transporters to these processes, however, are not known. In this study, we demonstrate that the trimeric transmembrane transporter domain fragment of glutamate transporters, lacking both N- and C-terminal cytoplasmic regions, localized to filopodia tips. This is a common property of trimeric transporters including a neutral amino acid transporter ASCT1. Astrocyte specific proteins are not required for the filopodia tip localization. An extracellular loop at the centre of the 4th transmembrane helices, unique for metazoans, is required for the localization. Moreover, a C186S mutation at the 4th transmembrane region of EAAT1, found in episodic ataxia patients, significantly decreased its process tip localization. The transmembrane transporter domain fragments of glutamate transporters also localized to astrocyte process tips in cultured hippocampal slice. These results indicate that the transmembrane transporter domain of glutamate transporters have an additional function as a sorting signal to process tips. PMID:25761899

  11. Passivated niobium cavities

    DOEpatents

    Myneni, Ganapati Rao; Hjorvarsson, Bjorgvin; Ciovati, Gianluigi

    2006-12-19

    A niobium cavity exhibiting high quality factors at high gradients is provided by treating a niobium cavity through a process comprising: 1) removing surface oxides by plasma etching or a similar process; 2) removing hydrogen or other gases absorbed in the bulk niobium by high temperature treatment of the cavity under ultra high vacuum to achieve hydrogen outgassing; and 3) assuring the long term chemical stability of the niobium cavity by applying a passivating layer of a superconducting material having a superconducting transition temperature higher than niobium thereby reducing losses from electron (cooper pair) scattering in the near surface region of the interior of the niobium cavity. According to a preferred embodiment, the passivating layer comprises niobium nitride (NbN) applied by reactive sputtering.

  12. Passive fetal monitoring sensor

    NASA Technical Reports Server (NTRS)

    Zuckerwar, Allan J. (Inventor); Hall, Earl T. (Inventor); Baker, Donald A. (Inventor); Bryant, Timothy D. (Inventor)

    1992-01-01

    An ambulatory, passive sensor for use in a fetal monitoring system is discussed. The invention is comprised of a piezoelectric polymer film, combined with a metallic mounting plate fastened to a belt, and electrically connected to a signal processing unit by means of a shielded cable. The purpose of the sensor is to receive pressure pulses emitted by a fetus inside an expectant mother. Additionally, the monitor will filter out pressure pulses arising from other sources, such as the maternal heart.

  13. Passive fetal monitoring sensor

    NASA Astrophysics Data System (ADS)

    Zuckerwar, Allan J.; Hall, Earl T.; Baker, Donald A.; Bryant, Timothy D.

    1992-08-01

    An ambulatory, passive sensor for use in a fetal monitoring system is discussed. The invention is comprised of a piezoelectric polymer film, combined with a metallic mounting plate fastened to a belt, and electrically connected to a signal processing unit by means of a shielded cable. The purpose of the sensor is to receive pressure pulses emitted by a fetus inside an expectant mother. Additionally, the monitor will filter out pressure pulses arising from other sources, such as the maternal heart.

  14. Passive fetal monitoring sensor

    NASA Astrophysics Data System (ADS)

    1990-07-01

    The invention is an ambulatory, passive sensor for use in a fetal monitoring system. The invention incorporates piezoelectric polymer film combined with a metallic mounting plate fastened to a belt and electrically connected to a signal processing unit by means of a shielded cable. The purpose of the sensor is to receive pressure pulses emitted from a fetus inside an expectant mother and to provide means for filtering out pressure pulses arising from other sources, such as the maternal heart.

  15. Radiobrightness Forward Modelling vs Observations from Local to Satellite Scales during the 2003 NASA Cold Land Processes Experiment

    NASA Technical Reports Server (NTRS)

    Kim, Edward J.; Tedesco, Marco

    2004-01-01

    A key issue for passive microwave Earth sensing applications is subpixel heterogeneity and its role in the connection between local-scale conditions vs. what is observed at the satellite footprint scale. The recently-completed NASA Cold Land Processes Field Experiment (CLPX-1) was designed to provide microwave remote sensing observations and ground truth for studies of snow and from ground remote sensing, particularly issues related to scaling. CLPX-1 was conducted in the spring of 2003 in Colorado, USA. Measurements of radiobrightness were made with nested footprint sizes ranging from scales of meters at a single site to 25 x 25 km across the entire CLPX-1 domain. Corresponding measurements of snowpack conditions (snow depth and temperature. density, and grain size profiles) as well as weather analyses were used to provide input data for forward radiative transfer model investigations. This paper will focus on the ability of forward modelling, based primarily on Dense Medium Radiative Transfer (DMRT) theory, combined with snowpack measurements and weather data to reproduce the radiobrightness signatures observed at multiple scales during both the third and fourth Intensive Observing Periods (February and March, 2003). The conditions include both wet and dry periods as well as a variety of forest cover conditions, providing a valuable test of model performance. These analyses will help guide the choice of future snow retrieval algorithm and the design of future Cold Lands observing systems.

  16. Decoupling absorption and emission processes in super-resolution localization of emitters in a plasmonic hotspot

    PubMed Central

    Mack, David L.; Cortés, Emiliano; Giannini, Vincenzo; Török, Peter; Roschuk, Tyler; Maier, Stefan A.

    2017-01-01

    The absorption process of an emitter close to a plasmonic antenna is enhanced due to strong local electromagnetic (EM) fields. The emission, if resonant with the plasmonic system, re-radiates to the far-field by coupling with the antenna via plasmonic states, whose presence increases the local density of states. Far-field collection of the emission of single molecules close to plasmonic antennas, therefore, provides mixed information of both the local EM field strength and the local density of states. Moreover, super-resolution localizations from these emission-coupled events do not report the real position of the molecules. Here we propose using a fluorescent molecule with a large Stokes shift in order to spectrally decouple the emission from the plasmonic system, leaving the absorption strongly resonant with the antenna's enhanced EM fields. We demonstrate that this technique provides an effective way of mapping the EM field or the local density of states with nanometre spatial resolution. PMID:28211479

  17. Decoupling absorption and emission processes in super-resolution localization of emitters in a plasmonic hotspot

    NASA Astrophysics Data System (ADS)

    Mack, David L.; Cortés, Emiliano; Giannini, Vincenzo; Török, Peter; Roschuk, Tyler; Maier, Stefan A.

    2017-02-01

    The absorption process of an emitter close to a plasmonic antenna is enhanced due to strong local electromagnetic (EM) fields. The emission, if resonant with the plasmonic system, re-radiates to the far-field by coupling with the antenna via plasmonic states, whose presence increases the local density of states. Far-field collection of the emission of single molecules close to plasmonic antennas, therefore, provides mixed information of both the local EM field strength and the local density of states. Moreover, super-resolution localizations from these emission-coupled events do not report the real position of the molecules. Here we propose using a fluorescent molecule with a large Stokes shift in order to spectrally decouple the emission from the plasmonic system, leaving the absorption strongly resonant with the antenna's enhanced EM fields. We demonstrate that this technique provides an effective way of mapping the EM field or the local density of states with nanometre spatial resolution.

  18. Management of local economic and ecological system of coal processing company

    NASA Astrophysics Data System (ADS)

    Kiseleva, T. V.; Mikhailov, V. G.; Karasev, V. A.

    2016-10-01

    The management issues of local ecological and economic system of coal processing company - coal processing plant - are considered in the article. The objectives of the research are the identification and the analysis of local ecological and economic system (coal processing company) performance and the proposals for improving the mechanism to support the management decision aimed at improving its environmental safety. The data on the structure of run-of-mine coal processing products are shown. The analysis of main ecological and economic indicators of coal processing enterprises, characterizing the state of its environmental safety, is done. The main result of the study is the development of proposals to improve the efficiency of local enterprise ecological and economic system management, including technical, technological and business measures. The results of the study can be recommended to industrial enterprises to improve their ecological and economic efficiency.

  19. Blasting and Passivation Treatments for ASTM F139 Stainless Steel for Biomedical Applications: Effects on Surface Roughness, Hardening, and Localized Corrosion

    NASA Astrophysics Data System (ADS)

    Barboza, Adriana L. Lemos; Kang, Kyung Won; Bonetto, Rita D.; Llorente, Carlos L.; Bilmes, Pablo D.; Gervasi, Claudio A.

    2015-01-01

    Due to the combination of good biofunctionality and biocompatibility at low cost, AISI 316 low carbon vacuum melting (LVM) stainless steel, as considered in ASTM F139 standard, is often the first choice for medical implants, particularly for use in orthopedic surgery. Proper surface finish must be provided to ensure adequate interactions of the alloy with human body tissues that in turn allows the material to deliver the desired performance. Preliminary studies performed in our laboratory on AISI 316LVM stainless steel surfaces modified by glass bead blasting (from industrial supplier) followed by different nitric acid passivation conditions disclosed the necessity to extend parameters of the surface treatments and to further consider roughness, pitting corrosion resistance, and surface and subsurface hardening measurements, all in one, as the most effective characterization strategy. This was the approach adopted in the present work. Roughness assessment was performed by means of amplitude parameters, functional parameters, and an estimator of the fractal dimension that characterizes surface topography. We clearly demonstrate that the blasting treatment should be carried out under controlled conditions in order to obtain similar surface and subsurface properties. Otherwise, a variation in one of the parameters could modify the surface properties, exerting a profound impact on its application as biomaterial. A passivation step is necessary to offset the detrimental effect of blasting on pitting corrosion resistance.

  20. Local and global processing of music in high-functioning persons with autism: beyond central coherence?

    PubMed

    Mottron, L; Peretz, I; Ménard, E

    2000-11-01

    A multi-modal abnormality in the integration of parts and whole has been proposed to account for a bias toward local stimuli in individuals with autism (Frith, 1989; Mottron & Belleville, 1993). In the current experiment, we examined the utility of hierarchical models in characterising musical information processing in autistic individuals. Participants were 13 high-functioning individuals with autism and 13 individuals of normal intelligence matched on chronological age, nonverbal IQ, and laterality, and without musical experience. The task consisted of same-different judgements of pairs of melodies. Differential local and global processing was assessed by manipulating the level, local or global, at which modifications occurred. No deficit was found in the two measures of global processing. In contrast, the clinical group performed better than the comparison group in the detection of change in nontransposed, contour-preserved melodies that tap local processing. These findings confirm the existence of a "local bias" in music perception in individuals with autism, but challenge the notion that it is accounted for by a deficit in global music processing. The present study suggests that enhanced processing of elementary physical properties of incoming stimuli, as found previously in the visual modality, may also exist in the auditory modality.

  1. Influence of focal point properties on energy transfer and plasma evolution during laser ignition process with a passively q-switched laser.

    PubMed

    Bärwinkel, Mark; Lorenz, Sebastian; Stäglich, Robert; Brüggemann, Dieter

    2016-07-11

    Miniaturized passively q-switched laser ignition systems are a promising alternative to conventional ignition sources to ensure a reliable ignition under difficult conditions. In this study the influences of focal point properties on energy transfer from laser to plasma as well as plasma formation and propagation are investigated as the first steps of the laser induced ignition process. Maximum fluence and fluence volume are introduced to characterize focal point properties for varying laser pulse energies and focusing configurations. The results show that the transferred laser energy increases with increasing maximum fluence. During laser emission plasma propagates along the beam path of the focused laser beam. Rising maximum fluence results in increased plasma volume, but expansion saturates when fluence volume reaches its maximum.

  2. Perception of Shapes Targeting Local and Global Processes in Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Grinter, Emma J.; Maybery, Murray T.; Pellicano, Elizabeth; Badcock, Johanna C.; Badcock, David R.

    2010-01-01

    Background: Several researchers have found evidence for impaired global processing in the dorsal visual stream in individuals with autism spectrum disorders (ASDs). However, support for a similar pattern of visual processing in the ventral visual stream is less consistent. Critical to resolving the inconsistency is the assessment of local and…

  3. Near-surface void characterization and sensitivity analysis using enhanced processing procedures on passive Multi-Channel Analysis of Surface Waves (MASW) data

    NASA Astrophysics Data System (ADS)

    Nolan, Jeffery Jordan

    Enhanced processing procedures on passive multichannel analysis of surface-waves (MASW) data were utilized to identify velocity anomalies above known salt solution voids in Hutchinson, Kansas, likely caused by the changing stress field due to the migration and/or expansion of the void. Previous geophysical studies within the study area provided information about the origin of the dominant passive surface-wave energy, allowing for an optimal spread orientation consisting of both 1D survey lines and a 2D grid. Occasional passing trains throughout the night generated surface-wave energy ranging from 4 Hz to 20 Hz for most recorded events. The use of the 2D grid allowed for identification of the orientation of wave propagation to correct the high apparent velocities caused by the oblique source orientation. Following acquisition, enhanced processing procedures such as time window stacking, percent keep, and source stacking, generated an overtone image with a higher signal-to-noise ratio and more pronounced fundamental mode energy. This visual improvement facilitated the extraction of fundamental mode energy, ultimately increasing the accuracy of the final shear-wave velocity profile. Velocity anomalies within the velocity profiles could likely be attributed to the changing of the stress field during the movement of the void. As the void expands laterally, the roof span increases. The increasing roof span likely increases the stress and shear velocity in the overburden load causing high-velocity haloes in the velocity profile. When the roof span becomes too large to support the overburden load, the roof rock will collapse, causing the migration of the void. Upon collapse, the non-collapsed overburden should accumulate stress due to the lack of underlying support, while the collapsed rock (rubble) should decrease in shear-wave velocity.

  4. Local Discriminability Determines the Strength of Holistic Processing for Faces in the Fusiform Face Area

    PubMed Central

    Goffaux, Valerie; Schiltz, Christine; Mur, Marieke; Goebel, Rainer

    2013-01-01

    Recent evidence suggests that the Fusiform Face Area (FFA) is not exclusively dedicated to the interactive processing of face features, but also contains neurons sensitive to local features. This suggests the existence of both interactive and local processing modes, consistent with recent behavioral findings that the strength of interactive feature processing (IFP) engages most strongly when similar features need to be disambiguated. Here we address whether the engagement of the FFA into interactive versus featural representational modes is governed by local feature discriminability. We scanned human participants while they matched target features within face pairs, independently of the context of distracter features. IFP was operationalized as the failure to match the target without being distracted by distracter features. Picture-plane inversion was used to disrupt IFP while preserving input properties. We found that FFA activation was comparably strong, irrespective of whether similar target features were embedded in dissimilar contexts(i.e., inducing robust IFP) or dissimilar target features were embedded in the same context (i.e., engaging local processing). Second, inversion decreased FFA activation to faces most robustly when similar target features were embedded in dissimilar contexts, indicating that FFA engages into IFP mainly when features cannot be disambiguated at a local level. Third, by means of Spearman rank correlation tests, we show that the local processing of feature differences in the FFA is supported to a large extent by the Occipital Face Area, the Lateral Occipital Complex, and early visual cortex, suggesting that these regions encode the local aspects of face information. The present findings confirm the co-existence of holistic and featural representations in the FFA. Furthermore, they establish FFA as the main contributor to the featural/holistic representational mode switches determined by local discriminability. PMID:23316180

  5. Systems Factorial Technology provides new insights on global–local information processing in autism spectrum disorders

    PubMed Central

    Johnson, Shannon A.; Blaha, Leslie M.; Houpt, Joseph W.; Townsend, James T.

    2010-01-01

    Previous studies of global–local processing in autism spectrum disorders (ASDs) have indicated mixed findings, with some evidence of a local processing bias, or preference for detail-level information, and other results suggesting typical global advantage, or preference for the whole or gestalt. Findings resulting from this paradigm have been used to argue for or against a detail focused processing bias in ASDs, and thus have important theoretical implications. We applied Systems Factorial Technology, and the associated Double Factorial Paradigm (both defined in the text), to examine information processing characteristics during a divided attention global–local task in high-functioning individuals with an ASD and typically developing controls. Group data revealed global advantage for both groups, contrary to some current theories of ASDs. Information processing models applied to each participant revealed that task performance, although showing no differences at the group level, was supported by different cognitive mechanisms in ASD participants compared to controls. All control participants demonstrated inhibitory parallel processing and the majority demonstrated a minimum-time stopping rule. In contrast, ASD participants showed exhaustive parallel processing with mild facilitatory interactions between global and local information. Thus our results indicate fundamental differences in the stopping rules and channel dependencies in individuals with an ASD. PMID:23750050

  6. Localization in covariance matrices of coupled heterogenous Ornstein-Uhlenbeck processes

    NASA Astrophysics Data System (ADS)

    Barucca, Paolo

    2014-12-01

    We define a random-matrix ensemble given by the infinite-time covariance matrices of Ornstein-Uhlenbeck processes at different temperatures coupled by a Gaussian symmetric matrix. The spectral properties of this ensemble are shown to be in qualitative agreement with some stylized facts of financial markets. Through the presented model formulas are given for the analysis of heterogeneous time series. Furthermore evidence for a localization transition in eigenvectors related to small and large eigenvalues in cross-correlations analysis of this model is found, and a simple explanation of localization phenomena in financial time series is provided. Finally we identify both in our model and in real financial data an inverted-bell effect in correlation between localized components and their local temperature: high- and low-temperature components are the most localized ones.

  7. Base Closures: Long and Costly Process of Reducing the Local National Work Force in Germany.

    DTIC Science & Technology

    1992-04-01

    from 4 months salary to 7 months.’ U.S. liability may also be affected by German labor law . For example, the German Termination Law could require...Agreement and German labor law can affect termination Complicated Process costs of local national employees. The Collective Tariff Agreement defines...Liability Agreement states that German labor laws are generally applicable to employment of local national civilians by the United States. The German Law on

  8. Feature binding and the processing of global-local shapes in bilingual and monolingual children.

    PubMed

    Cottini, Milvia; Pieroni, Laura; Spataro, Pietro; Devescovi, Antonella; Longobardi, Emiddia; Rossi-Arnaud, Clelia

    2015-04-01

    In the present study, we examined the effects of bilingualism and age on a color-shape binding task (assessing visual working memory) and a global-local task (assessing inhibitory processes) in a sample of 55 bilingual and 49 monolingual children 8 and 10 years old. In the color-shape binding task, corrected recognition scores increased in older children; bilingual children performed better than monolinguals in the shape-only condition, but the two groups were equally accurate in the color-only and combination conditions. In the global-local task, accuracy was higher in bilingual than in monolingual children, particularly on incongruent trials; monolingual children showed a strong global precedence effect (higher accuracy in the global than in the local conditions and greater global-to-local interference), whereas bilingual children exhibited a small, but significant, local precedence effect (higher accuracy in the local than in the global conditions and greater local-to-global interference). These findings confirm and extend previous evidence indicating that the bilingualism advantage is more pronounced in working memory tasks involving inhibitory processes.

  9. Local active information storage as a tool to understand distributed neural information processing.

    PubMed

    Wibral, Michael; Lizier, Joseph T; Vögler, Sebastian; Priesemann, Viola; Galuske, Ralf

    2014-01-01

    Every act of information processing can in principle be decomposed into the component operations of information storage, transfer, and modification. Yet, while this is easily done for today's digital computers, the application of these concepts to neural information processing was hampered by the lack of proper mathematical definitions of these operations on information. Recently, definitions were given for the dynamics of these information processing operations on a local scale in space and time in a distributed system, and the specific concept of local active information storage was successfully applied to the analysis and optimization of artificial neural systems. However, no attempt to measure the space-time dynamics of local active information storage in neural data has been made to date. Here we measure local active information storage on a local scale in time and space in voltage sensitive dye imaging data from area 18 of the cat. We show that storage reflects neural properties such as stimulus preferences and surprise upon unexpected stimulus change, and in area 18 reflects the abstract concept of an ongoing stimulus despite the locally random nature of this stimulus. We suggest that LAIS will be a useful quantity to test theories of cortical function, such as predictive coding.

  10. Structural and functional characterization of human telomerase RNA processing and cajal body localization signals.

    PubMed

    Theimer, Carla A; Jády, Beáta E; Chim, Nicholas; Richard, Patricia; Breece, Katherine E; Kiss, Tamás; Feigon, Juli

    2007-09-21

    The RNA component of human telomerase (hTR) includes H/ACA and CR7 domains required for 3' end processing, localization, and accumulation. The terminal loop of the CR7 domain contains the CAB box (ugAG) required for targeting of scaRNAs to Cajal bodies (CB) and an uncharacterized sequence required for accumulation and processing. To dissect out the contributions of the CR7 stem loop to hTR processing and localization, we solved the solution structures of the 3' terminal stem loops of hTR CR7 and U64 H/ACA snoRNA, and the 5' terminal stem loop of U85 C/D-H/ACA scaRNA. These structures, together with analysis of localization, processing, and accumulation of hTRs containing nucleotide substitutions in the CR7 domain, identified the sequence and structural requirements of the hTR processing and CB localization signals and showed that these signals are functionally independent. Further, 3' end processing was found to be a prerequisite for translocation of hTR to CBs.

  11. ERP evidence of a meaningfulness impact on visual global/local processing: when meaning captures attention.

    PubMed

    Beaucousin, Virginie; Cassotti, Mathieu; Simon, Grégory; Pineau, Arlette; Kostova, Milena; Houdé, Olivier; Poirel, Nicolas

    2011-04-01

    Event-related potentials (ERPs) were recorded to investigate whether the meaningfulness of experimental stimuli impacted performances during global/local visual tasks. Participants were presented with compound stimuli, based on either meaningful letters, meaningful objects, or meaningless non-objects. The ERP recordings displayed typical early components, P1 and N1, evoked by task-related processes that affected global and local processes differently according to the meaningfulness of the stimuli. The effect of meaningfulness of the stimuli during global processing showed that P1 amplitudes were larger in response to objects and non-objects compared to letters, while letters and objects elicited larger N1 amplitudes than non-objects. Second, during local processing, the mean amplitudes of the ERPs recorded for object and letter stimuli were systematically smaller than the amplitudes recorded for non-object stimuli for both P1 and N1 components. In addition, object and letter stimuli elicited comparable mean ERP responses during local processing. These results are discussed in terms of the influences of both attentional and top-down identification processes. Taken together, these findings suggested that looking for meaning is crucial in the perception of visual scenes and that the meaningfulness nature of the stimuli should be taken into account in future studies.

  12. Evaluation of Alternate Surface Passivation Methods (U)

    SciTech Connect

    Clark, E

    2005-05-31

    Stainless steel containers were assembled from parts passivated by four commercial vendors using three passivation methods. The performance of these containers in storing hydrogen isotope mixtures was evaluated by monitoring the composition of initially 50% H{sub 2} 50% D{sub 2} gas with time using mass spectroscopy. Commercial passivation by electropolishing appears to result in surfaces that do not catalyze hydrogen isotope exchange. This method of surface passivation shows promise for tritium service, and should be studied further and considered for use. On the other hand, nitric acid passivation and citric acid passivation may not result in surfaces that do not catalyze the isotope exchange reaction H{sub 2} + D{sub 2} {yields} 2HD. These methods should not be considered to replace the proprietary passivation processes of the two current vendors used at the Savannah River Site Tritium Facility.

  13. Electrical conductivity images across the Namibian passive margin: Implications for tectonic processes along the Kaoko Belt, the western Kongo Craton and the Walvis Ridge

    NASA Astrophysics Data System (ADS)

    Weckmann, Ute; Meqbel, Naser; Kapinos, Gerhard; Jegen-Kulcsar, Marion; Ritter, Oliver

    2014-05-01

    The Special Priority Programme SAMPLE of the German Science Foundation DFG is focussed on investigating processes related to the breakup of supercontinent Gondwana and the post breakup evolution of the passive continental margins of Africa and South America. Within this framework an amphibian magnetotelluric (MT) experiment was conducted at the Southern African passive continental margin, starting at the Walvis Ridge in the Atlantic Ocean and crossing onshore the entire Kaoko Belt and the western boundary of the Kongo Craton in Northern Namibia. High-quality MT data at 167 onshore and xx offshore sites show a strong variability within short distances and indicate complex subsurface structures in parts of the Kaoko Belt and along some of the major thrust and fault zones. To identify the main conductivity features and resolve their properties in more spatial detail we started our modelling procedure with 2D inversion for a sub-set of the data where the 3D effects are less dominant along the amphibian profile. However, to account for 3D effects in the MT data and to assess robustness of conductivity anomalies revealed in the 2D model we used the entire data set for the 3D inversion using ModEM. 2D and 3D inversion models show zones of high electrical conductivity that correlate with surface expressions of prominent faults such as the Purros Mylonite Zone and the Three Palm Mylonite Zone of the Kaoko Belt. Outcropping Etendeka flood basalts in the Western Kaoko Zones are imaged by 10-15km deep reaching zones of high resistivity. Additionally, the inversion models reveal a spatial correlation of resistive zones with the cratonic Northern Platform; however, the geologically defined onset of the Kongo Craton appears as an area of high conductivity. Compared with other craton boundaries in Southern Africa this is very untypical.

  14. Gestalt perception and local-global processing in high-functioning autism.

    PubMed

    Bölte, Sven; Holtmann, Martin; Poustka, Fritz; Scheurich, Armin; Schmidt, Lutz

    2007-09-01

    This study examined gestalt perception in high-functioning autism (HFA) and its relation to tasks indicative of local visual processing. Data on of gestalt perception, visual illusions (VI), hierarchical letters (HL), Block Design (BD) and the Embedded Figures Test (EFT) were collected in adult males with HFA, schizophrenia, depression and normative controls. Individuals with HFA processed gestalt stimuli less in accord with gestalt laws, particularly regarding the principle of similarity. Gestalt processing correlated positively with global processing of the HL. EFT and BD performance correlated negatively with VI susceptibility in HFA. All clinical groups succumbed less to VI than the normative sample. Results suggest decreased gestalt perception in HFA, being associated with a more general local visual processing bias.

  15. Mapping Flow Localization Processes in Deformation of Irradiated Reactor Structural Alloys

    SciTech Connect

    Farrell, K.

    2002-07-18

    Metals that can sustain plastic deformation homogeneously throughout their bulk tend to be tough and malleable. Often, however, if a metal has been hardened it will no longer deform uniformly. Instead, the deformation occurs in narrow bands on a microscopic scale wherein stresses and strains become concentrated in localized zones. This strain localization degrades the mechanical properties of the metal by causing premature plastic instability failure or by inducing the formation of cracks. Irradiation with neutrons hardens a metal and makes it more prone to deformation by strain localization. Although this has been known since the earliest days of radiation damage studies, a full measure of the connection between neutron irradiation hardening and strain localization is wanting, particularly in commercial alloys used in the construction of nuclear reactors. Therefore, the goal of this project is to systematically map the extent of involvement of strain localization processes in plastic deformation of three reactor alloys that have been neutron irradiated. The deformation processes are to be identified and related to changes in the tensile properties of the alloys as functions of neutron fluence (dose) and degree of plastic strain. The intent is to define the role of strain localization in radiation embrittlement phenomena. The three test materials are a tempered bainitic A533B steel, representing reactor pressure vessel steel, an annealed 316 stainless steel and annealed Zircaloy-4 representing reactor internal components.

  16. Prism adaptation reverses the local processing bias in patients with right temporo-parietal junction lesions

    PubMed Central

    Rafal, Robert D.; List, Alexandra

    2009-01-01

    Lesions to the right temporo-parietal cortex commonly result in hemispatial neglect. Lesions to the same area are also associated with hyperattention to local details of a scene and difficulty perceiving the global structure. This local processing bias is an important factor contributing to neglect and may contribute to the higher prevalence of the disorder following right compared with left hemisphere strokes. In recent years, visuomotor adaptation to rightward-shifting prisms has been introduced as a promising treatment for hemispatial neglect. Explanations for these improvements have generally described a leftward realignment of attention, however, the present investigation provides evidence that prism adaptation reduces the local processing bias. Five patients with right temporal-parietal junction lesions were asked to identify the global or local levels of hierarchical figures before and after visuomotor adaptation to rightward-shifting prisms. Prior to prism adaptation the patients had difficulty ignoring the local elements when identifying the global component. Following prism adaptation, however, this pattern was reversed, with greater global interference during local level identification. The results suggest that prism adaptation may improve non-spatially lateralized deficits that contribute to the neglect syndrome. PMID:19416951

  17. Permeability Reduction in Passively Degassing Seawater-dominated Volcanic-hydrothermal systems: Processes and Perils on Raoul Island, Kermadecs (NZ)

    NASA Astrophysics Data System (ADS)

    Christenson, B. W.; Reyes, A. G.

    2014-12-01

    The 2006 eruption from Raoul Island occurred apparently in response to local tectonic swarm activity, but without any precursory indication of volcanic unrest within the hydrothermal system on the island. The eruption released some 200 T of SO2, implicating the involvement of a deep magmatic vapor input into the system during/prior to the event. In the absence of any recognized juvenile material in the eruption products, previous explanations for this eruptive event focused on this vapor being a driving force for the eruption. In 2004, at least 80 T/d of CO2 was escaping from the hydrothermal system, but mainly through areas that did not correspond to the 2006 eruption vents. The lack of a pre-eruptive hydrothermal system response related to the seismic event in 2006 can be explained by the presence of a hydrothermal mineralogic seal in the vent area of the volcano. Evidence for the existence of such a seal was found in eruption deposits in the form of massive fracture fillings of aragonite, calcite and anhydrite. Fluid inclusion homogenization temperatures in these phases range from ca. 140 °C to 220 °C which, for pure water indicate boiling point depths of between 40 and 230 m assuming a cold hydrostatic pressure constraint. Elevated pressures behind this seal are consistent with the occurrence of CO2 clathrates in some inclusion fluids, indicating CO2 concentrations approaching 1 molal in the parent fluids. Reactive transport modeling of magmatic volatile inputs into what is effectively a seawater-dominated hydrothermal system provide valuable insights into seal formation. Carbonate mineral phases ultimately come to saturation along this flow path, but we suggest that focused deposition of the observed massive carbonate seal is facilitated by near-surface boiling of these CO2-enriched altered seawaters, leading to large degrees of supersaturation which are required for the formation of aragonite. As the seal grew and permeability declined, pore pressures

  18. Kinect Posture Reconstruction Based on a Local Mixture of Gaussian Process Models.

    PubMed

    Liu, Zhiguang; Zhou, Liuyang; Leung, Howard; Shum, Hubert P H

    2016-11-01

    Depth sensor based 3D human motion estimation hardware such as Kinect has made interactive applications more popular recently. However, it is still challenging to accurately recognize postures from a single depth camera due to the inherently noisy data derived from depth images and self-occluding action performed by the user. In this paper, we propose a new real-time probabilistic framework to enhance the accuracy of live captured postures that belong to one of the action classes in the database. We adopt the Gaussian Process model as a prior to leverage the position data obtained from Kinect and marker-based motion capture system. We also incorporate a temporal consistency term into the optimization framework to constrain the velocity variations between successive frames. To ensure that the reconstructed posture resembles the accurate parts of the observed posture, we embed a set of joint reliability measurements into the optimization framework. A major drawback of Gaussian Process is its cubic learning complexity when dealing with a large database due to the inverse of a covariance matrix. To solve the problem, we propose a new method based on a local mixture of Gaussian Processes, in which Gaussian Processes are defined in local regions of the state space. Due to the significantly decreased sample size in each local Gaussian Process, the learning time is greatly reduced. At the same time, the prediction speed is enhanced as the weighted mean prediction for a given sample is determined by the nearby local models only. Our system also allows incrementally updating a specific local Gaussian Process in real time, which enhances the likelihood of adapting to run-time postures that are different from those in the database. Experimental results demonstrate that our system can generate high quality postures even under severe self-occlusion situations, which is beneficial for real-time applications such as motion-based gaming and sport training.

  19. From local to global processing: the development of illusory contour perception.

    PubMed

    Nayar, Kritika; Franchak, John; Adolph, Karen; Kiorpes, Lynne

    2015-03-01

    Global visual processing is important for segmenting scenes, extracting form from background, and recognizing objects. Local processing involves attention to the local elements, contrast, and boundaries of an image at the expense of extracting a global percept. Previous work is inconclusive regarding the relative development of local and global processing. Some studies suggest that global perception is already present by 8 months of age, whereas others suggest that the ability arises during childhood and continues to develop during adolescence. We used a novel method to assess the development of global processing in 3- to 10-year-old children and an adult comparison group. We used Kanizsa illusory contours as an assay of global perception and measured responses on a touch-sensitive screen while monitoring eye position with a head-mounted eye tracker. Participants were tested using a similarity match-to-sample paradigm. Using converging measures, we found a clear developmental progression with age such that the youngest children performed near chance on the illusory contour discrimination, whereas 7- and 8-year-olds performed nearly perfectly, as did adults. There was clear evidence of a gradual shift from a local processing strategy to a global one; young children looked predominantly at and touched the "pacman" inducers of the illusory form, whereas older children and adults looked predominantly at and touched the middle of the form. These data show a prolonged developmental trajectory in appreciation of global form, with a transition from local to global visual processing between 4 and 7 years of age.

  20. Gibbs free energy assisted passivation layers

    NASA Astrophysics Data System (ADS)

    Salihoglu, Omer; Tansel, T.; Hostut, M.; Ergun, Y.; Aydinli, A.

    2016-05-01

    Reduction of surface leakage is a major challenge in most photodetectors that requires the elimination of surface oxides on etched mesas during passivation. Engineering the passivation requires close attention to chemical reactions that take place at the interface during the process. In particular, removal of surface oxides may be controlled via Gibbs reactivity. We have compared electrical performance of type-II superlattice photodetectors, designed for MWIR operation, passivated by different passivation techniques. We have used ALD deposited Al2O3, HfO2, TiO2, ZnO, PECVD deposited SiO2, Si3N4 and sulphur containing octadecanethiol (ODT) selfassembled monolayers (SAM) passivation layers on InAs/GaSb p-i-n superlattice photodetectors with cutoff wavelength at 5.1 μm. In this work, we have compared the result of different passivation techniques which are done under same conditions, same epitaxial structure and same fabrication processes. We have found that ALD deposited passivation is directly related to the Gibbs free energy of the passivation material. Gibbs free energies of the passivation layer can directly be compared with native surface oxides to check the effectiveness of the passivation layer before the experimental study.

  1. Enhanced Photocurrents with ZnS Passivated Cu(In,Ga)(Se,S)2 Photocathodes Synthesized Using a Nonvacuum Process for Solar Water Splitting.

    PubMed

    Chae, Sang Youn; Park, Se Jin; Han, Sung Gyu; Jung, Hyejin; Kim, Chae-Woong; Jeong, Chaehwan; Joo, Oh-Shim; Min, Byoung Koun; Hwang, Yun Jeong

    2016-12-07

    Chalcopyrite Cu(In,Ga)(Se,S)2 (CIGS) semiconductors are potential candidates for use in photoelectrochemical (PEC) hydrogen generation due to their excellent optical absorption properties and high conduction band edge position. In the present research, CIGS thin film was successfully prepared on a transparent substrate (F:SnO2 glass) using a solution-based process and applied for a photocathode in solar water splitting, which shows control of the surface state associated with sulfurization/selenization process significantly influences on the PEC activity. A ZnS passivation surface layer was introduced, which effectively suppresses charge recombination by surface states of CIGS. The CIGS/ZnS/Pt photocathode exhibited highly enhanced PEC activity (∼24 mA·cm(-2) at -0.3 V vs RHE). The performances of our CIGS photocathode on the transparent substrate were also characterized under front/back light illumination, and the incident photon to current conversion efficiency (IPCE) drastically changed depending on the illumination directions showing decreased IPCE especially under UV region with back illumination. The slow minority carrier (electron) transportation is suggested as a limiting factor for the PEC activity of the CIGS photocathode.

  2. Influence of Second Language Proficiency and Syntactic Structure Similarities on the Sensitivity and Processing of English Passive Sentence in Late Chinese-English Bilinguists: An ERP Study.

    PubMed

    Chang, Xin; Wang, Pei

    2016-02-01

    To investigate the influence of L2 proficiency and syntactic similarity on English passive sentence processing, the present ERP study asked 40 late Chinese-English bilinguals (27 females and 13 males, mean age = 23.88) with high or intermediate L2 proficiency to read the sentences carefully and to indicate for each sentence whether or not it was correct. Sentences were classified into literal translation sentences with the similar structure between the two languages and free translation sentences with the different structure. Behavioral data showed: shorter reaction times and higher accuracy rates occurred in the high-proficient group than those in the intermediate-proficient group; shorter reaction times and higher accuracy rates were observed in literal translation sentences than those in free translation sentences. ERP results showed literal translation sentences elicited an enhanced P200 and P600 while free translation sentences elicited a larger N400. The high-proficient group showed a larger P600 in syntactic violations and double violations while the intermediate-proficient group evoked an enhanced N400 in semantic violations and double violations. Literal translation sentences caused a larger P200 while free translation sentences elicited more negative-going N400. Behavioral and ERP data revealed the influence of L2 proficiency and syntactic similarity on L2 sentence processing, and L2 proficiency played a predominate role.

  3. Effects of Local and Global Context on Processing Sentences with Subject and Object Relative Clauses

    ERIC Educational Resources Information Center

    Yang, Fang; Mo, Lun; Louwerse, Max M.

    2013-01-01

    An eye tracking study investigated the effects of local and global discourse context on the processing of subject and object relative clauses, whereby the contexts favored either a subject relative clause interpretation or an object relative clause interpretation. The fixation data replicated previous studies showing that object relative clause…

  4. Visual Search in ASD: Instructed versus Spontaneous Local and Global Processing

    ERIC Educational Resources Information Center

    Van der Hallen, Ruth; Evers, Kris; Boets, Bart; Steyaert, Jean; Noens, Ilse; Wagemans, Johan

    2016-01-01

    Visual search has been used extensively to investigate differences in mid-level visual processing between individuals with ASD and TD individuals. The current study employed two visual search paradigms with Gaborized stimuli to assess the impact of task distractors (Experiment 1) and task instruction (Experiment 2) on local-global visual…

  5. Are the Autism and Positive Schizotypy Spectra Diametrically Opposed in Local versus Global Processing?

    ERIC Educational Resources Information Center

    Russell-Smith, Suzanna N.; Maybery, Murray T.; Bayliss, Donna M.

    2010-01-01

    Crespi and Badcock (2008) proposed that autism and psychosis represent two extremes on a cognitive spectrum with normality at its center. Their specific claim that autistic and positive schizophrenia traits contrastingly affect preference for local versus global processing was investigated by examining Embedded Figures Test performance in two…

  6. Gestalt Perception and Local-Global Processing in High-Functioning Autism

    ERIC Educational Resources Information Center

    Bolte, Sven; Holtmann, Martin; Poustka, Fritz; Scheurich, Armin; Schmidt, Lutz

    2007-01-01

    This study examined gestalt perception in high-functioning autism (HFA) and its relation to tasks indicative of local visual processing. Data on of gestalt perception, visual illusions (VI), hierarchical letters (HL), Block Design (BD) and the Embedded Figures Test (EFT) were collected in adult males with HFA, schizophrenia, depression and…

  7. Localized Mechanical Properties of Friction Stir Processed Sensitized 5456-H116 Al

    DTIC Science & Technology

    2013-04-01

    FSP is applied to a sensitized 5456-H116 aluminum plate and the resulting microstructure is linked to local mechanical properties (0.2% yield...have negatively affected the mechanical properties 15. SUBJECT TERMS Aluminum Alloys, Friction Stir Processing, Sensitization, Mechanical Testing... aluminum 5456-H116 (wt. %) ..............................................3 Table 2. Bulk base material properties for H116, O, and sensitized H116

  8. Material Processing Handbook. The Wisconsin Guide to Local Curriculum Improvement in Industrial Education K-12.

    ERIC Educational Resources Information Center

    Wisconsin State Dept. of Public Instruction, Madison. Div. of Instructional Services.

    This handbook is intended to aid industrial educators in developing material processing activities for their programs; it is especially designed to aid educators in implementing "The Wisconsin Guide to Local Curriculum Improvement in Industrial Education, K-12." The guide provides suggested outlines and models that could be used to…

  9. Spatiotemporal dynamics of processing nonsymbolic number: an event-related potential source localization study.

    PubMed

    Hyde, Daniel C; Spelke, Elizabeth S

    2012-09-01

    Coordinated studies with adults, infants, and nonhuman animals provide evidence for two distinct systems of nonverbal number representation. The "parallel individuation" (PI) system selects and retains information about one to three individual entities and the "numerical magnitude" system establishes representations of the approximate cardinal value of a group. Recent event-related potential (ERP) work has demonstrated that these systems reliably evoke functionally and temporally distinct patterns of brain response that correspond to established behavioral signatures. However, relatively little is known about the neural generators of these ERP signatures. To address this question, we targeted known ERP signatures of these systems, by contrasting processing of small versus large nonsymbolic numbers, and used a source localization algorithm (LORETA) to identify their cortical origins. Early processing of small numbers, showing the signature effects of PI on the N1 (∼150 ms), was localized primarily to extrastriate visual regions. In contrast, qualitatively and temporally distinct processing of large numbers, showing the signatures of approximate number representation on the mid-latency P2p (∼200-250 ms), was localized primarily to right intraparietal regions. In comparison, mid-latency small number processing was localized to the right temporal-parietal junction and left-lateralized intraparietal regions. These results add spatial information to the emerging ERP literature documenting the process by which we represent number. Furthermore, these results substantiate recent claims that early attentional processes determine whether a collection of objects will be represented through PI or as an approximate numerical magnitude by providing evidence that downstream processing diverges to distinct cortical regions.

  10. [The contribution of muscle progenitor cells to maintaining morphological characteristics of unweighted rat soleus muscle during passive stretch].

    PubMed

    Tarakina, M V; Turtikova, O V; Nemirovskaia, T L; Kokontsev, A A; Shenkman, B S

    2008-01-01

    Skeletal muscle work hypertrophy is usually connected with muscle progenitor SC (satellite cells) activation with subsequent incorporation their nuclei into myofibers. Passive stretch of unloaded muscle was earlier established to prevent atrophic processes and be accompanied by enhanced protein synthesis. We hypothesized that elimination of SC proliferation capacity by gamma-irradiation would partly preavent stretched muscle fiber capability to maintain their size under condition of gravitational unloading. To assess the role of muscle progenitor (satellite) cells in development of passive stretch preventive effect SC proliferation was suppressed by local exposure to ionizing radiation (2500 Rad) and then subsequent hindlimb suspension or hindlimb suspension with concomitant passive stretch were carried out. Reduction of myofiber cross-sectional area and decrease in myo-nuclei number accompanying unloaded muscle atrophy were completely abolished by passive stretch both in irradiated and sham-treated animals. We concluded that satellite cells did not make essential contribution to passive stretch preventive action under condition of simulated weightlessness.

  11. An improved solution of local window parameters setting for local singularity analysis based on Excel VBA batch processing technology

    NASA Astrophysics Data System (ADS)

    Zhang, Daojun; Cheng, Qiuming; Agterberg, Frits; Chen, Zhijun

    2016-03-01

    In this paper Excel VBA is used for batch calculation in Local Singularity Analysis (LSA), which is for the information extracting from different kinds of geoscience data. Capabilities and advantages of a new module called Batch Tool for Local Singularity Index Mapping (BTLSIM) are: (1) batch production of series of local singularity maps with different settings of local window size, shape and orientation parameters; (2) local parameter optimization based on statistical tests; and (3) provision of extra output layers describing how spatial changes induced by parameter optimization are related to spatial structure of the original input layers.

  12. Effects of Local and Non-Local Processes on the Aging of the Tropopause Layer and the Lower Stratosphere

    NASA Astrophysics Data System (ADS)

    Pittman, J. V.; Wofsy, S. C.; Daube, B. C.; Smith, J. B.; Anderson, J. G.; Gao, R. S.; Rollins, A. W.; Thornberry, T. D.; Watts, L. A.; Hintsa, E. J.; Moore, F. L.; Elkins, J. W.; Dlugokencky, E. J.; Andrews, A. E.; Atlas, E. L.; Navarro, M. A.; Schauffler, S.; Bui, T. V.; Pfister, L.; Liang, Q.; Wang, T.

    2015-12-01

    As concentrations of greenhouse gases continue to increase in the troposphere, general circulation models predict an acceleration in the Brewer-Dobson circulation (BDC). A common diagnostic used to evaluate this change in circulation is age of air, which is defined as the time elapsed since stratospheric air was last in contact with the troposphere. An acceleration in the BDC can lead to shorter residence times and hence younger age of air. This change would affect the chemical distribution of pollutants and ozone-depleting substances in the stratosphere and potentially impact the recovery of the stratospheric ozone layer. In this study, we use in-situ measurements and model outputs to derive and compare vertical profiles of age of air and to assess the impact of various dynamical processes on age of air over the tropics and Northern Hemisphere midlatitudes. We focus on measurements of winds and several tracers with varying atmospheric lifetimes recently obtained in the tropopause region and lower stratosphere during the NASA ATTREX and NASA SEAC4RS campaigns between Jan 2013 and Mar 2014. We derive age of air using CO2 measurements at the surface and at altitude. This tracer is nearly chemically inert in the atmosphere and has well-known sources at the surface: an increasing trend over time resulting from anthropogenic activity and a superimposed seasonal cycle resulting from photosynthesis and respiration by the biosphere. During the field deployments, we encountered episodes of contrasting transport and mixing processes compared to background conditions, namely local and non-local convection as identified by trajectories and distinct chemical signatures, nearby typhoons, wave activity, and shifts in large-scale circulation. In addition to aircraft measurements, we also examine data from earlier high-altitude balloon flights, which allowed us to sample deeper into the stratosphere. We complement the observations with model outputs from the NASA GEOS-5 atmospheric

  13. Understanding the Local Socio-political Processes Affecting Conservation Management Outcomes in Corbett Tiger Reserve, India

    NASA Astrophysics Data System (ADS)

    Rastogi, Archi; Hickey, Gordon M.; Badola, Ruchi; Hussain, Syed Ainul

    2014-05-01

    Several measures have been recommended to guarantee a sustainable population of tigers: sufficient inviolate spaces for a viable population, sufficient prey populations, trained and skilled manpower to guard against poaching and intrusion, banning trade in tiger products to reduce poaching, and importantly, the political will to precipitate these recommendations into implementation. Of these, the creation of sufficient inviolate spaces (generally in the form of protected areas) has created the most issues with local resource-dependent communities, often resulting in significant challenges for tiger conservation policy and management. Very little empirical research has, however, been done to understand and contextualize the local-level socio-political interactions that may influence the efficacy of tiger conservation in India. In this paper, we present the results of exploratory research into the ways in which local-stakeholder groups affect the management of Corbett Tiger Reserve (CTR). Using a combined grounded theory-case study research design, and the Institutional Analysis and Development framework for analysis, we identify the socio-political processes through which local-stakeholder groups are able to articulate their issues and elicit desirable actions from the management of CTR. Increasing our awareness of these processes can help inform the design and implementation of more effective tiger conservation management and policy strategies that have the potential to create more supportive coalitions of tiger conservation stakeholders at the local level.

  14. Understanding the local socio-political processes affecting conservation management outcomes in Corbett Tiger Reserve, India.

    PubMed

    Rastogi, Archi; Hickey, Gordon M; Badola, Ruchi; Hussain, Syed Ainul

    2014-05-01

    Several measures have been recommended to guarantee a sustainable population of tigers: sufficient inviolate spaces for a viable population, sufficient prey populations, trained and skilled manpower to guard against poaching and intrusion, banning trade in tiger products to reduce poaching, and importantly, the political will to precipitate these recommendations into implementation. Of these, the creation of sufficient inviolate spaces (generally in the form of protected areas) has created the most issues with local resource-dependent communities, often resulting in significant challenges for tiger conservation policy and management. Very little empirical research has, however, been done to understand and contextualize the local-level socio-political interactions that may influence the efficacy of tiger conservation in India. In this paper, we present the results of exploratory research into the ways in which local-stakeholder groups affect the management of Corbett Tiger Reserve (CTR). Using a combined grounded theory-case study research design, and the Institutional Analysis and Development framework for analysis, we identify the socio-political processes through which local-stakeholder groups are able to articulate their issues and elicit desirable actions from the management of CTR. Increasing our awareness of these processes can help inform the design and implementation of more effective tiger conservation management and policy strategies that have the potential to create more supportive coalitions of tiger conservation stakeholders at the local level.

  15. Impaired Global, and Compensatory Local, Biological Motion Processing in People with High Levels of Autistic Traits

    PubMed Central

    van Boxtel, Jeroen J. A.; Lu, Hongjing

    2013-01-01

    People with Autism Spectrum Disorder (ASD) are hypothesized to have poor high-level processing but superior low-level processing, causing impaired social recognition, and a focus on non-social stimulus contingencies. Biological motion perception provides an ideal domain to investigate exactly how ASD modulates the interaction between low and high-level processing, because it involves multiple processing stages, and carries many important social cues. We investigated individual differences among typically developing observers in biological motion processing, and whether such individual differences associate with the number of autistic traits. In Experiment 1, we found that individuals with fewer autistic traits were automatically and involuntarily attracted to global biological motion information, whereas individuals with more autistic traits did not show this pre-attentional distraction. We employed an action adaptation paradigm in the second study to show that individuals with more autistic traits were able to compensate for deficits in global processing with an increased involvement in local processing. Our findings can be interpreted within a predictive coding framework, which characterizes the functional relationship between local and global processing stages, and explains how these stages contribute to the perceptual difficulties associated with ASD. PMID:23630514

  16. Subcellular localization of cytoplasmic lattice-associated proteins is dependent upon fixation and processing procedures.

    PubMed

    Morency, Eric; Anguish, Lynne; Coonrod, Scott

    2011-02-16

    We and others have recently demonstrated by immuno-EM and mutation analysis that two oocyte-restricted maternal effect genes, PADI6 and MATER, localize, in part, to the oocyte cytoplasmic lattices (CPLs). During these ongoing studies, however, we found that the localization of these factors by confocal immunofluorescence (IF) analysis can vary dramatically depending upon how the oocytes and embryos are processed, with the localization pattern sometimes appearing more uniformly cytoplasmic while at other times appearing to be primarily cortical. We set out to better understand this differential staining pattern by testing a range of IF protocol parameters, changing mainly time and temperature conditions of the primary antibody solution incubation, as well as fixation methods. We found by confocal IF whole mount analysis that PADI6 and MATER localization in germinal vesicle stage oocytes is mainly cytoplasmic when the oocytes are fixed and then incubated with primary antibodies at room temperature for 1 hour, while the localization of these factors is largely limited to the cortex when the oocytes are fixed and incubated in primary antibody at 4 °C overnight. We then probed sections of fixed/embedded ovaries and isolated two-cell embryos with specific antibodies and found that, under these conditions, PADI6 and MATER were again primarily cytoplasmically localized, although the staining for these factors is slightly more cortical at the two-cell stage. Taken together, our results suggest that the localization of CPL-associated proteins by confocal IF is particularly affected by processing conditions. Further, based on our current observations, it appears that PADI6 and MATER are primarily distributed throughout the cytoplasm as opposed to the oocyte subcortex.

  17. Effects of local and global context on processing sentences with subject and object relative clauses.

    PubMed

    Yang, Fang; Mo, Lun; Louwerse, Max M

    2013-06-01

    An eye tracking study investigated the effects of local and global discourse context on the processing of subject and object relative clauses, whereby the contexts favored either a subject relative clause interpretation or an object relative clause interpretation. The fixation data replicated previous studies showing that object relative clause sentences were more difficult to process than subject relative sentences. Crucially, however, the reading difficulty asymmetry between subject and object relative clause sentences disappeared when the sentences were presented with a local or a global discourse context that favored the objects in the object relative clauses. These findings demonstrate that the evidence for a syntax-based account of sentence processing is found when sentences are presented in isolation. However, if sentences are placed more naturally, in context, discourse factors outweigh the initial structural assignment.

  18. Spread spectrum fiber-optic local area network using optical processing

    NASA Technical Reports Server (NTRS)

    Prucnal, P. R.; Santoro, M. A.; Fan, T. R.

    1986-01-01

    Spread spectrum code division multiple access (CDMA) allows asynchronous multiple access to a local area network (LAN) with no waiting. The additional bandwidth required by spread spectrum can be accommodated by using a fiber-optic channel and incoherent optical signal processing. New CDMA sequences are designed specifically for optical processing. It is shown that increasing the number of chips per bit, by using optical processing, allows an increase in capacity of a CDMA LAN. An experiment is performed demonstrating the performance of an optical CDMA LAN, operating at 100 Mbd with three users.

  19. The cold land processes experiment (CLPX) local scale observatin site (LSOS)

    NASA Technical Reports Server (NTRS)

    McDonald, K. C.; Hardy, J. P.; Cline, D.; Elder, K.; Davis, R.; Pomeroy, J.; Koh, G.; Armstrong, R.; Koike, T.

    2002-01-01

    The Local Scale Observation Site (LSOS) is the smallest study site of the Cold LandProcesses Experiment (CLPX) and is located within the Fraser Meso-cell Study Area (MSA), near the Fraser Experimental Forest Headquarters Facility, in Fraser, CO USA.The 100-m x 100-m site consists of a small open field, a managed dense canopy and an open, mixed age canopy. Unlike the other components of the experiment, which focus on spatial distributions at relatively brief snapshots in time, measurements at the local scale site focused on the temporal domain.

  20. Global-local visual processing impacts risk taking behaviors, but only at first

    PubMed Central

    Lim, Stephen Wee Hun; Yuen, Alexander Y. L.; Tong, Eddie M. W.

    2015-01-01

    We investigated the impact of early visual processing on decision-making during unpredictable, risky situations. Participants undertook Navon’s (1977) task and attended to either global letters or local letters only, following which they completed the Balloon Analogue Risk Task (BART). It was observed that global-focused individuals made more balloon pumps during the BART (i.e., took more risk), whereas local-focused individuals took less risk, albeit only initially. The theory of predictive and reactive control systems (PARCS) provides an excellent account of the data. Implications and future directions are discussed. PMID:26379586

  1. Wavelength tuning of planar photonic crystals by local processing of individual holes.

    PubMed

    Kicken, H H J E; Alkemade, P F A; van der Heijden, R W; Karouta, F; Nötzel, R; van der Drift, E; Salemink, H W M

    2009-11-23

    Tuning of the resonant wavelength of a single hole defect cavity in planar photonic crystals was demonstrated using transmission spectroscopy. Local post-production processing of single holes in a planar photonic crystal is carried out after selectively opening a masking layer by focused ion beam milling. The resonance was blue-shifted by enlargement of selected holes using local wet chemical etching and red-shifted by infiltration with liquid crystals. This method can be applied to precisely control the resonant frequency, and can also be used for mode selective tuning.

  2. Development of the reverse passive latex agglutination method for the detection and quantification of the genus Nitrospira in the wastewater treatment process.

    PubMed

    Okumura, Takekazu; Nagai, Fumiko; Yamamoto, Shuta; Hashimoto, Toshikazu; Ito, Masahiko; Sawada, Haruji

    2008-02-01

    This report describes a new immunological method for the detection and quantification of Nitrospira populations using the reverse passive latex agglutination (RPLA). The numbers of the genus Nitrospira have been quantified only by molecular biological techniques such as FISH and quantitative PCR to date. Using high-density latex particles and a specific polyclonal antibody, Nitrospira populations in the wastewater treatment process were quantified in the shortest 4 h of incubation. The minimum detectable number of Nitrospira cells was 7.0x10(5) (log(10) 5.85) cells/ml. It is thought that the RPLA method can quantify Nitrospira populations more simply, economically, and speedily than molecular biological techniques or the culture method, because this procedure has a simple protocol and does not require the use of specialized equipment, expensive reagents, or technical skill. Therefore it is applicable for use in the everyday control and maintenance of water quality in wastewater treatment facilities where equipment is not sufficient or in the field.

  3. Enhanced local processing of dynamic visual information in autism: evidence from speed discrimination.

    PubMed

    Chen, Y; Norton, D J; McBain, R; Gold, J; Frazier, J A; Coyle, J T

    2012-04-01

    An important issue for understanding visual perception in autism concerns whether individuals with this neurodevelopmental disorder possess an advantage in processing local visual information, and if so, what is the nature of this advantage. Perception of movement speed is a visual process that relies on computation of local spatiotemporal signals but requires the comparison of information from more than a single spatial location or temporal point. This study examined speed discrimination in adolescents (ages 13-18 years old) with autism spectrum disorders (ASD). Compared to healthy controls (n=17), individuals with ASD (n=19) showed similarly precise speed discrimination when two comparison motion stimuli (random dot patterns) were presented closely in time (0.5s). With a longer temporal interval (3s) between the motion stimuli, individuals with ASD outperformed healthy controls on speed discrimination. On a second task--global motion perception--in which individuals were asked to detect coherent motion, individuals with ASD exhibited slightly degraded performance levels. The observed temporally selective enhancement in speed discrimination indicates that a local processing advantage in autism develops over a longer temporal range and is not limited to the spatial domain. These results suggest a dynamic perceptual mechanism for understanding, and therapeutically addressing, atypical visual processing in this neurodevelopmental disorder.

  4. Local and global processing in block design tasks in children with dyslexia or nonverbal learning disability.

    PubMed

    Cardillo, Ramona; Mammarella, Irene C; Garcia, Ricardo Basso; Cornoldi, Cesare

    2017-04-02

    Visuo-constructive and perceptual abilities have been poorly investigated in children with learning disabilities. The present study focused on local or global visuospatial processing in children with nonverbal learning disability (NLD) and dyslexia compared with typically-developing (TD) controls. Participants were presented with a modified block design task (BDT), in both a typical visuo-constructive version that involves reconstructing figures from blocks, and a perceptual version in which respondents must rapidly match unfragmented figures with a corresponding fragmented target figure. The figures used in the tasks were devised by manipulating two variables: the perceptual cohesiveness and the task uncertainty, stimulating global or local processes. Our results confirmed that children with NLD had more problems with the visuo-constructive version of the task, whereas those with dyslexia showed only a slight difficulty with the visuo-constructive version, but were in greater difficulty with the perceptual version, especially in terms of response times. These findings are interpreted in relation to the slower visual processing speed of children with dyslexia, and to the visuo-constructive problems and difficulty in using flexibly-experienced global vs local processes of children with NLD. The clinical and educational implications of these findings are discussed.

  5. The Role of Musical Experience in Hemispheric Lateralization of Global and Local Auditory Processing.

    PubMed

    Black, Emily; Stevenson, Jennifer L; Bish, Joel P

    2017-01-01

    The global precedence effect is a phenomenon in which global aspects of visual and auditory stimuli are processed before local aspects. Individuals with musical experience perform better on all aspects of auditory tasks compared with individuals with less musical experience. The hemispheric lateralization of this auditory processing is less well-defined. The present study aimed to replicate the global precedence effect with auditory stimuli and to explore the lateralization of global and local auditory processing in individuals with differing levels of musical experience. A total of 38 college students completed an auditory-directed attention task while electroencephalography was recorded. Individuals with low musical experience responded significantly faster and more accurately in global trials than in local trials regardless of condition, and significantly faster and more accurately when pitches traveled in the same direction (compatible condition) than when pitches traveled in two different directions (incompatible condition) consistent with a global precedence effect. In contrast, individuals with high musical experience showed less of a global precedence effect with regards to accuracy, but not in terms of reaction time, suggesting an increased ability to overcome global bias. Further, a difference in P300 latency between hemispheres was observed. These findings provide a preliminary neurological framework for auditory processing of individuals with differing degrees of musical experience.

  6. Passive Acoustic Detection and Localization of Mesoplodon Densirostris (Blainville’s Beaked Whale) Vocalization Using Distributed Bottom-Mounted Hydrophones in Conjunction With a Digital Tag (DTAG) Recording

    DTIC Science & Technology

    2008-10-01

    éventail de référence situé dans la Langue de l’océan, Bahamas. Deux détecteurs, une transformation rapide de Fourier (FFT) basée détecteur et filtre ... filtre adapté est la plus performante, ce qui permet à 92% des animaux marqués de clics pour être détectés sur au moins un des hydrophones. Time...to time-synchronized 3D localizations by adjusting the swim speed to a least-squares match (Figure 11). Figure 10: Original DTag Kalman -filtered

  7. Low-Temperature Process for Atomic Layer Chemical Vapor Deposition of an Al2O3 Passivation Layer for Organic Photovoltaic Cells.

    PubMed

    Kim, Hoonbae; Lee, Jihye; Sohn, Sunyoung; Jung, Donggeun

    2016-05-01

    Flexible organic photovoltaic (OPV) cells have drawn extensive attention due to their light weight, cost efficiency, portability, and so on. However, OPV cells degrade quickly due to organic damage by water vapor or oxygen penetration when the devices are driven in the atmosphere without a passivation layer. In order to prevent damage due to water vapor or oxygen permeation into the devices, passivation layers have been introduced through methods such as sputtering, plasma enhanced chemical vapor deposition, and atomic layer chemical vapor deposition (ALCVD). In this work, the structural and chemical properties of Al2O3 films, deposited via ALCVD at relatively low temperatures of 109 degrees C, 200 degrees C, and 300 degrees C, are analyzed. In our experiment, trimethylaluminum (TMA) and H2O were used as precursors for Al2O3 film deposition via ALCVD. All of the Al2O3 films showed very smooth, featureless surfaces without notable defects. However, we found that the plastic flexible substrate of an OPV device passivated with 300 degrees C deposition temperature was partially bended and melted, indicating that passivation layers for OPV cells on plastic flexible substrates need to be formed at temperatures lower than 300 degrees C. The OPV cells on plastic flexible substrates were passivated by the Al2O3 film deposited at the temperature of 109 degrees C. Thereafter, the photovoltaic properties of passivated OPV cells were investigated as a function of exposure time under the atmosphere.

  8. Human motion tracking by temporal-spatial local gaussian process experts.

    PubMed

    Zhao, Xu; Fu, Yun; Liu, Yuncai

    2011-04-01

    Human pose estimation via motion tracking systems can be considered as a regression problem within a discriminative framework. It is always a challenging task to model the mapping from observation space to state space because of the high-dimensional characteristic in the multimodal conditional distribution. In order to build the mapping, existing techniques usually involve a large set of training samples in the learning process which are limited in their capability to deal with multimodality. We propose, in this work, a novel online sparse Gaussian Process (GP) regression model to recover 3-D human motion in monocular videos. Particularly, we investigate the fact that for a given test input, its output is mainly determined by the training samples potentially residing in its local neighborhood and defined in the unified input-output space. This leads to a local mixture GP experts system composed of different local GP experts, each of which dominates a mapping behavior with the specific covariance function adapting to a local region. To handle the multimodality, we combine both temporal and spatial information therefore to obtain two categories of local experts. The temporal and spatial experts are integrated into a seamless hybrid system, which is automatically self-initialized and robust for visual tracking of nonlinear human motion. Learning and inference are extremely efficient as all the local experts are defined online within very small neighborhoods. Extensive experiments on two real-world databases, HumanEva and PEAR, demonstrate the effectiveness of our proposed model, which significantly improve the performance of existing models.

  9. Tropospheric Passive Remote Sensing

    NASA Technical Reports Server (NTRS)

    Keafer, L. S., Jr. (Editor)

    1982-01-01

    The long term role of airborne/spaceborne passive remote sensing systems for tropospheric air quality research and the identification of technology advances required to improve the performance of passive remote sensing systems were discussed.

  10. Passive storage technologies

    NASA Technical Reports Server (NTRS)

    Kittel, P.

    1984-01-01

    Advances in storage technology and how passive techniques could be applied to the storage of propellants at the space station are described. The devices considered are passive orbital disconnect struts, cooled shield optimization, liftweight shields and catalytic converters.

  11. Place as a social space: fields of encounter relating to the local sustainability process.

    PubMed

    Dumreicher, Heidi; Kolb, Bettina

    2008-04-01

    The paper shows how sustainability questions relate to the local space. The local place is not a static entity, but a dynamic one, undergoing constant changes, and it is the rapid social and material processes within the given local situation that is a challenge for the Chinese villages and their integrity. The following article considers the cohesion between the dwellers' emotional co-ownership of their local space and the sustainability process as a driving force in social, economic and ecological development. We bring together the classification of the seven fields of encounter, which were developed out of the empirical data of the Chinese case study villages, and sustainability oriented management considerations for all levels of this concept. We do not pretend to know the solutions, but describe a set of interrelated fields that can be anchor points for placing the solutions and show in which fields action and intervention is possible. In our concept of sustainability, every spatial field has its special meaning, needs special measures and policies and has different connotations to concepts like responsibility, family values or communication systems. We see the social sustainability process as a support for the empowerment of the local dwellers, and the SUCCESS research has encouraged the villages to find suitable sustainability oriented solutions for their natural and societal situation. Before entering the discussion about the chances and potential of a sustainability approach for the Chinese villages, it is first necessary to accept the fact that rural villages play a primordial role in Chinese society and that their potential can strengthen future pathways for China.

  12. Angioedema attacks in patients with hereditary angioedema: Local manifestations of a systemic activation process.

    PubMed

    Hofman, Zonne L M; Relan, Anurag; Zeerleder, Sacha; Drouet, Christian; Zuraw, Bruce; Hack, C Erik

    2016-08-01

    Hereditary angioedema (HAE) caused by a deficiency of functional C1-inhibitor (C1INH) becomes clinically manifest as attacks of angioedema. C1INH is the main inhibitor of the contact system. Poor control of a local activation process of this system at the site of the attack is believed to lead to the formation of bradykinin (BK), which increases local vasopermeability and mediates angioedema on interaction with BK receptor 2 on the endothelium. However, several observations in patients with HAE are difficult to explain from a pathogenic model claiming a local activation process at the site of the angioedema attack. Therefore we postulate an alternative model for angioedema attacks in patients with HAE, which assumes a systemic, fluid-phase activation of the contact system to generate BK and its breakdown products. Interaction of these peptides with endothelial receptors that are locally expressed in the affected tissues rather than with receptors constitutively expressed by the endothelium throughout the whole body explains that such a systemic activation process results in local manifestations of an attack. In particular, BK receptor 1, which is induced on the endothelium by inflammatory stimuli, such as kinins and cytokines, meets the specifications of the involved receptor. The pathogenic model discussed here also provides an explanation for why angioedema can occur at multiple sites during an attack and why HAE attacks respond well to modest increases of circulating C1INH activity levels because inhibition of fluid-phase Factor XIIa and kallikrein requires lower C1INH levels than inhibition of activator-bound factors.

  13. Local Versus Global Effects of Isoflurane Anesthesia on Visual Processing in the Fly Brain

    PubMed Central

    2016-01-01

    Abstract What characteristics of neural activity distinguish the awake and anesthetized brain? Drugs such as isoflurane abolish behavioral responsiveness in all animals, implying evolutionarily conserved mechanisms. However, it is unclear whether this conservation is reflected at the level of neural activity. Studies in humans have shown that anesthesia is characterized by spatially distinct spectral and coherence signatures that have also been implicated in the global impairment of cortical communication. We questioned whether anesthesia has similar effects on global and local neural processing in one of the smallest brains, that of the fruit fly (Drosophila melanogaster). Using a recently developed multielectrode technique, we recorded local field potentials from different areas of the fly brain simultaneously, while manipulating the concentration of isoflurane. Flickering visual stimuli (‘frequency tags’) allowed us to track evoked responses in the frequency domain and measure the effects of isoflurane throughout the brain. We found that isoflurane reduced power and coherence at the tagging frequency (13 or 17 Hz) in central brain regions. Unexpectedly, isoflurane increased power and coherence at twice the tag frequency (26 or 34 Hz) in the optic lobes of the fly, but only for specific stimulus configurations. By modeling the periodic responses, we show that the increase in power in peripheral areas can be attributed to local neuroanatomy. We further show that the effects on coherence can be explained by impacted signal-to-noise ratios. Together, our results show that general anesthesia has distinct local and global effects on neuronal processing in the fruit fly brain. PMID:27517084

  14. Structural damage localization by outlier analysis of signal-processed mode shapes - Analytical and experimental validation

    NASA Astrophysics Data System (ADS)

    Ulriksen, M. D.; Damkilde, L.

    2016-02-01

    Contrary to global modal parameters such as eigenfrequencies, mode shapes inherently provide structural information on a local level. Therefore, this particular modal parameter and its derivatives are utilized extensively for damage identification. Typically, more or less advanced mathematical methods are employed to identify damage-induced discontinuities in the spatial mode shape signals, hereby, potentially, facilitating damage detection and/or localization. However, by being based on distinguishing damage-induced discontinuities from other signal irregularities, an intrinsic deficiency in these methods is the high sensitivity towards measurement noise. In the present paper, a damage localization method which, compared to the conventional mode shape-based methods, has greatly enhanced robustness towards measurement noise is proposed. The method is based on signal processing of a spatial mode shape by means of continuous wavelet transformation (CWT) and subsequent application of a generalized discrete Teager-Kaiser energy operator (GDTKEO) to identify damage-induced mode shape discontinuities. In order to evaluate whether the identified discontinuities are in fact damage-induced, outlier analysis is conducted by applying the Mahalanobis metric to major principal scores of the sensor-located bands of the signal-processed mode shape. The method is tested analytically and benchmarked with other mode shape-based damage localization approaches on the basis of a free-vibrating beam and validated experimentally in the context of a residential-sized wind turbine blade subjected to an impulse load.

  15. GWM-2005 - A Groundwater-Management Process for MODFLOW-2005 with Local Grid Refinement (LGR) Capability

    USGS Publications Warehouse

    Ahlfeld, David P.; Baker, Kristine M.; Barlow, Paul M.

    2009-01-01

    This report describes the Groundwater-Management (GWM) Process for MODFLOW-2005, the 2005 version of the U.S. Geological Survey modular three-dimensional groundwater model. GWM can solve a broad range of groundwater-management problems by combined use of simulation- and optimization-modeling techniques. These problems include limiting groundwater-level declines or streamflow depletions, managing groundwater withdrawals, and conjunctively using groundwater and surface-water resources. GWM was initially released for the 2000 version of MODFLOW. Several modifications and enhancements have been made to GWM since its initial release to increase the scope of the program's capabilities and to improve its operation and reporting of results. The new code, which is called GWM-2005, also was designed to support the local grid refinement capability of MODFLOW-2005. Local grid refinement allows for the simulation of one or more higher resolution local grids (referred to as child models) within a coarser grid parent model. Local grid refinement is often needed to improve simulation accuracy in regions where hydraulic gradients change substantially over short distances or in areas requiring detailed representation of aquifer heterogeneity. GWM-2005 can be used to formulate and solve groundwater-management problems that include components in both parent and child models. Although local grid refinement increases simulation accuracy, it can also substantially increase simulation run times.

  16. BicD-dependent localization processes: from Drosophilia development to human cell biology.

    PubMed

    Claussen, Maike; Suter, Beat

    2005-11-01

    Many eukaryotic cells depend on proper cell polarization for their development and physiological function. The establishment of these polarities often involve the subcellular localization of a specific subset of proteins, RNAs and organelles. In Drosophila, the microtubule-dependent BicD (BicaudalD) localization machinery is involved in the proper localization of mRNA during oogenesis and embryogenesis and the proper positioning of the oocyte and photoreceptor nuclei. BicD acts together with the minus-end directed motor dynein as well as Egl and Lis-1. The finding that the mammalian homologs of BicD function in retrograde Golgi-to-ER transport has supported the view that BicD may be part of a repeatedly used and evolutionary conserved localization machinery. In this review we focus on the various processes in which BicD is involved during Drosophilian development and in mammals. In addition, we evaluate the interactions between BicD, the dynein localization machinery and associated factors.

  17. SU-E-T-61: A Practical Process for Fabricating Passive Scatter Proton Beam Modulation Compensation Filters Using 3D Printing

    SciTech Connect

    Zhao, T; Drzymala, R

    2015-06-15

    Purpose: The purpose of this project was to devise a practical fabrication process for passive scatter proton beam compensation filters (CF) that is competitive in time, cost and effort using 3D printing. Methods: DICOM compensator filter files for a proton beam were generated by our Eclipse (Varian, Inc.) treatment planning system. The compensator thickness specifications were extracted with in-house software written in Matlab (MathWorks, Inc.) code and written to a text file which could be read by the Rhinoceros 5, computer-aided design (CAD) package (Robert McNeel and Associates), which subsequently generated a smoothed model in a STereoLithographic also known as a Standard Tesselation Language file (STL). The model in the STL file was subsequently refined using Netfabb software and then converted to printing instructions using Cura. version 15.02.1. for our 3D printer. The Airwolf3D, model HD2x, fused filament fabrication (FFF) 3D printer (Airwolf3D.com) was used for our fabrication system with a print speed of 150mm per second. It can print in over 22 different plastic filament materials in a build volume of 11” x 8” x 12”. We choose ABS plastic to print the 3D model of the imprint for our CFs. Results: Prints of the CF could be performed at a print speed of 70mm per second. The time to print the 3D topology for the CF for the 14 cm diameter snout of our Mevion 250 proton accelerator was less than 3 hours. The printed model is intended to subsequently be used as a mold to imprint a molten wax cylindrical to form the compensation after cooling. The whole process should be performed for a typical 3 beam treatment plan within a day. Conclusion: Use of 3D printing is practical and can be used to print a 3D model of a CF within a few hours.

  18. Fabrication Process of Fine Electrodes Using Shadow Mask Evaporation and Tip-Induced Local Oxidation

    NASA Astrophysics Data System (ADS)

    Akai, Tomonori; Abe, Takumi; Ishibashi, Masayoshi; Kato, Midori; Heike, Seiji; Shimomura, Takeshi; Okai, Makoto; Hashizume, Tomihiro; Ito, Kohzo

    2002-07-01

    We report on a simple process for fabricating fine electrodes by using shadow mask evaporation and tip-induced local oxidation. A set of electrodes for four-term resistance measurement has been fabricated. The gap width between the fine electrode was 150 nm and the roughness of the electrode surface was less than 0.5 nm. We were able to use the electrodes to measure the conductivity of a multiwalled carbon nanotube (MWNT).

  19. Method of Relaxation Moments for Studying Nonlinear Locally Nonequilibrium Processes of Transfer of Polymeric Systems

    NASA Astrophysics Data System (ADS)

    Popov, V. I.

    2015-01-01

    A method for simulating the processes of transfer of thermodynamic systems with polymeric microstructure is considered. The method is based on the classical locally equilibrium medium-state entropy concept expanded by the introduction of a structural tensor parameter whose evolution characterizes the nonlinear anisotropic relaxation properties of a thermodynamic system and the associated transfer phenomena. The dynamic, thermal, and mass transfer characteristics of macrotransfer are determined by corresponding integrals of relaxation moments.

  20. Data Processing Approach for Localizing Bio-magnetic Sources in the Brain

    NASA Astrophysics Data System (ADS)

    Pai, Hung-I.; Tseng, Chih-Yuan; Lee, H. C.

    2007-07-01

    Magnetoencephalography (MEG) provides dynamic spatial-temporal insight for neural activities in the cortex. Because the possible number of sources is far greater than the number of MEG detectors, the proposition to localize sources directly from MEG data is ill-posed. Here we develop a novel approach based on a sequence of data processing procedures that includes a clustering process, an intersection analysis, and an application of the maximum entropy method. We examine the performance of our method and compare it with the minimum-norm least-square inverse method using an artificial noisy MEG data.

  1. Tracking marine mammals using passive acoustics

    NASA Astrophysics Data System (ADS)

    Nosal, Eva-Marie

    2007-12-01

    It is difficult to study the behavior and physiology of marine mammals or to understand and mitigate human impact on them because much of their lives are spent underwater. Since sound propagates for long distances in the ocean and since many cetaceans are vocal, passive acoustics is a valuable tool for studying and monitoring their behavior. After a brief introduction to and review of passive acoustic tracking methods, this dissertation develops and applies two new methods. Both methods use widely-spaced (tens of kilometers) bottom-mounted hydrophone arrays, as well as propagation models that account for depth-dependent sound speed profiles. The first passive acoustic tracking method relies on arrival times of direct and surface-reflected paths. It is used to track a sperm whale using 5 at the Atlantic Undersea Test and Evaluation Center (AUTEC) and gives position estimates that are accurate to within 10 meters. With such accuracy, the whale's pitch and yaw are estimated by assuming that its main axis (which points from the tail to the rostrum) is parallel to its velocity. Roll is found by fitting the details of the pulses within each sperm whale click to the so-called bent horn model of sperm whale sound production. Finally, given the position and orientation of the whale, its beam pattern is reconstructed and found to be highly directional with an intense forward directed component. Pair-wise spectrogram (PWS) processing is the second passive acoustic tracking method developed in this dissertation. Although it is computationally more intensive, PWS has several advantages over arrival-time tracking methods, especially in shallow water environments, for long duration calls, and for multiple-animal datasets, as is the case for humpback whales on Hawaiian breeding grounds. Results of simulations with realistic noise conditions and environmental mismatch are given and compared to other passive localization techniques. When applied to the AUTEC sperm whale dataset, PWS

  2. Techniques for processing eyes implanted with a retinal prosthesis for localized histopathological analysis.

    PubMed

    Nayagam, David A X; McGowan, Ceara; Villalobos, Joel; Williams, Richard A; Salinas-LaRosa, Cesar; McKelvie, Penny; Lo, Irene; Basa, Meri; Tan, Justin; Williams, Chris E

    2013-08-02

    With the recent development of retinal prostheses, it is important to develop reliable techniques for assessing the safety of these devices in preclinical studies. However, the standard fixation, preparation, and automated histology procedures are not ideal. Here we describe new procedures for evaluating the health of the retina directly adjacent to an implant. Retinal prostheses feature electrode arrays in contact with eye tissue. Previous methods have not been able to spatially localize the ocular tissue adjacent to individual electrodes within the array. In addition, standard histological processing often results in gross artifactual detachment of the retinal layers when assessing implanted eyes. Consequently, it has been difficult to assess localized damage, if present, caused by implantation and stimulation of an implanted electrode array. Therefore, we developed a method for identifying and localizing the ocular tissue adjacent to implanted electrodes using a (color-coded) dye marking scheme, and we modified an eye fixation technique to minimize artifactual retinal detachment. This method also rendered the sclera translucent, enabling localization of individual electrodes and specific parts of an implant. Finally, we used a matched control to increase the power of the histopathological assessments. In summary, this method enables reliable and efficient discrimination and assessment of the retinal cytoarchitecture in an implanted eye.

  3. Impacts of tropical deforestation. Part I: Process analysis of local climatic change

    SciTech Connect

    Zhang, H.; Henderson-Sellers, A.; McGuffie, K.

    1996-07-01

    The potential impacts of deforestation in the humid Tropics are examined using a version of the National Center for Atmospheric Research`s CCM1 coupled with the Biosphere-Atmosphere Transfer Scheme package. Tropical deforestation in South America, Africa, and Southeast Asia is studied using the results from an 11-yr deforestation experiment and a 25-yr control integration. It is found that the local-scale impact (here defined as within the area deforested) varies greatly between the three deforested regions due to the differing controls on the local atmospheric circulation: the Southeast Asian monsoon is much less sensitive to deforestation than the low-level flow over South America. The analysis of the changes in cloud radiative forcing suggests that reduction in cloud amount can significantly mitigate the imposed increases in surface albedo. The importance of water recycling by the forest canopy is stressed in the simulation of local precipitation changes. Correlation analysis of the changes resulting from the deforestation has been used to determine the nature of the processes that follow from the removal of the forest canopy and to suggest the important processes. The role of large-scale dynamics is explored in a companion paper. 44 refs., 9 figs., 5 tabs.

  4. Local media monitoring in process evaluation. Experiences from the Stockholm Diabetes Prevention Programme.

    PubMed

    Andersson, Camilla Maria; Bjärås, Gunilla; Tillgren, Per; Ostenson, Claes-Göran

    2007-01-01

    We present a rationale and approach for longitudinal analyses of media coverage and content, and illustrate how media monitoring can be used in process evaluations. Within a community-based diabetes prevention project, the Stockholm Diabetes Prevention Program, we analyzed the frequency, prominence, and framing of physical activity in local newspapers of three intervention and two control municipalities. In total, 2,128 stories and advertisements related to physical activity were identified between the years 1997 and 2002. Although stories about physical activity were relatively few (n = 224), they were prominently located in all five local newspapers. Physical activity was framed rather similarly in the municipalities. Health aspects, however, were expressed to a greater extent in stories in two of the intervention municipalities. A limited portion (14%) of the articles could be linked directly to the program. It is not possible to assess to what extent the program has had a disseminating effect on the newspapers' health-related content in general, due to weaknesses of the process tracking system and limitations of the study design. Implications for the design is that an evaluative framework should be preplanned and include data collection about media relationships, media's interest in public health, media coverage prior to the program and coverage in other media for comparisons of general trends in the reporting. The material and the current database, however, provide a good basis for quantitative content analysis and qualitative discourse analysis to yield information on the type, frequency, and content of health reporting in local newspapers.

  5. Insights to caving processes from localization of microseismic swarms induced by salt solution mining

    NASA Astrophysics Data System (ADS)

    Lennart Kinscher, Jannes; Bernard, Pascal; Contrucci, Isabelle; Mangeney, Anne; Piguet, Jack Pierre; Bigarre, Pascal

    2014-05-01

    In order to improve our understanding of hazardous ground failures, caving processes, and collapses of large natural or man-made underground cavities, we studied microseismicity induced by the development and collapse of a salt solution mining cavity with a diameter of ~ 200 m at Cerville-Buissoncourt in Lorraine, France. Microseismicity was recorded as part of a large geophysical, multi-parameter monitoring research project (GISOS) by a local, high resolution, triggered 40 Hz geophone monitoring system consisting of five one-component and four three-component borehole stations located around and in the center of the cavity. The recorded microseismic events are very numerous (~ 50.000 recorded event files) where the major portion (~ 80 %) appear in unusual swarming sequences constituted by complex clusters of superimposed microseismic events. Body wave phase based routine tools for microseismic event detection and localization face strong limitations in the treatment of these signals. To overcome these shortcomings, we developed two probabilistic methods being able to assess the spatio-temporal characteristics in a semi-automatic manner. The first localization approach uses simple signal amplitude estimates on different frequency bands, and an attenuation model to constrain hypocenter source location. The second approach was designed to identify significantly polarized P wave energies and the associated polarization angles. Both approaches and its probabilistic conjunction were applied to the data of a two months lasting microseismic crisis occurring one year before the final collapse that was related to caving processes leading to a maximal growth of ~ 50 m of the cavity roof. The obtained epicenter locations show systematic spatio-temporal migration trends observed for different time scales. During three phases of major swarming activity, epicenter migration trends appear in the order of several seconds to minutes, are spatially constrained, and show partially a

  6. Local competition and metapopulation processes drive long-term seagrass-epiphyte population dynamics.

    PubMed

    Lobelle, Delphine; Kenyon, Emma J; Cook, Kevan J; Bull, James C

    2013-01-01

    It is well known that ecological processes such as population regulation and natural enemy interactions potentially occur over a range of spatial scales, and there is a substantial body of literature developing theoretical understanding of the interplay between these processes. However, there are comparatively few studies quantifying the long-term effects of spatial scaling in natural ecosystems. A key challenge is that trophic complexity in real-world biological communities quickly obscures the signal from a focal process. Seagrass meadows provide an excellent opportunity in this respect: in many instances, seagrasses effectively form extensive natural monocultures, in which hypotheses about endogenous dynamics can be formulated and tested. We present amongst the longest unbroken, spatially explict time series of seagrass abundance published to date. Data include annual measures of shoot density, total above-ground abundance, and associated epiphyte cover from five Zostera marina meadows distributed around the Isles of Scilly, UK, from 1996 to 2011. We explore empirical patterns at the local and metapopulation scale using standard time series analysis and develop a simple population dynamic model, testing the hypothesis that both local and metapopulation scale feedback processes are important. We find little evidence of an interaction between scales in seagrass dynamics but that both scales contribute approximately equally to observed local epiphyte abundance. By quantifying the long-term dynamics of seagrass-epiphyte interactions we show how measures of density and extent are both important in establishing baseline information relevant to predicting responses to environmental change and developing management plans. We hope that this study complements existing mechanistic studies of physiology, genetics and productivity in seagrass, whilst highlighting the potential of seagrass as a model ecosystem. More generally, this study provides a rare opportunity to test

  7. A compact and versatile microfluidic probe for local processing of tissue sections and biological specimens

    NASA Astrophysics Data System (ADS)

    Cors, J. F.; Lovchik, R. D.; Delamarche, E.; Kaigala, G. V.

    2014-03-01

    The microfluidic probe (MFP) is a non-contact, scanning microfluidic technology for local (bio)chemical processing of surfaces based on hydrodynamically confining nanoliter volumes of liquids over tens of micrometers. We present here a compact MFP (cMFP) that can be used on a standard inverted microscope and assist in the local processing of tissue sections and biological specimens. The cMFP has a footprint of 175 × 100 × 140 mm3 and can scan an area of 45 × 45 mm2 on a surface with an accuracy of ±15 μm. The cMFP is compatible with standard surfaces used in life science laboratories such as microscope slides and Petri dishes. For ease of use, we developed self-aligned mounted MFP heads with standardized "chip-to-world" and "chip-to-platform" interfaces. Switching the processing liquid in the flow confinement is performed within 90 s using a selector valve with a dead-volume of approximately 5 μl. We further implemented height-compensation that allows a cMFP head to follow non-planar surfaces common in tissue and cellular ensembles. This was shown by patterning different macroscopic copper-coated topographies with height differences up to 750 μm. To illustrate the applicability to tissue processing, 5 μm thick M000921 BRAF V600E+ melanoma cell blocks were stained with hematoxylin to create contours, lines, spots, gradients of the chemicals, and multiple spots over larger areas. The local staining was performed in an interactive manner using a joystick and a scripting module. The compactness, user-friendliness, and functionality of the cMFP will enable it to be adapted as a standard tool in research, development and diagnostic laboratories, particularly for the interaction with tissues and cells.

  8. Effect of high-pressure processing of bovine colostrum on immunoglobulin G concentration, pathogens, viscosity, and transfer of passive immunity to calves.

    PubMed

    Foster, Derek M; Poulsen, Keith P; Sylvester, Hannah J; Jacob, Megan E; Casulli, Kaitlyn E; Farkas, Brian E

    2016-11-01

    This study aimed to determine the effects of high-pressure processing on the immunoglobulin concentration, microbial load, viscosity, and transfer of passive immunity to calves when applied to bovine colostrum as an alternative to thermal pasteurization. A pilot study using Staphylococcus aureus was conducted to determine which pressure-time treatments are most appropriate for use with bovine colostrum, with the goals of maximizing bacterial inactivation while minimizing IgG content and viscosity changes. Following the pilot study, an inoculation study was conducted in which first-milking colostrum samples from Holstein-Friesian cows were inoculated with known concentrations of various bacteria or viruses and pressure processed at either 300 MPa for up to 60min or at 400MPa for up to 30min. The recovery of total native aerobic bacteria, Escherichia coli, Salmonella enterica ssp. enterica serovar Dublin, Mycobacterium avium ssp. paratuberculosis, bovine herpesvirus type 1, and feline calicivirus were determined after processing. Colostrum IgG content was measured before and after pressure processing. Shear stress and viscosity for each treatment was determined over shear rates encompassing those found during calf feeding and at normal bovine body temperature (37.8°C). Following a calf trial, serum IgG concentration was measured in 14 calves fed 4 L of colostrum pressure processed at 400MPa for 15min. In the pilot study, S. aureus was effectively reduced with pressure treatment at 300 and 400MPa (0, 5, 10, 15, 30, and 45min), with 2 treatments at 400MPa (30, 45min) determined to be inappropriate for use with bovine colostrum due to viscosity and IgG changes. High-pressure processing at 300MPa (30, 45, and 60min) and 400MPa (10, 15, and 20min) was shown to effectively reduce total native aerobic bacteria, E. coli, Salmonella Dublin, bovine herpesvirus type 1, and feline calicivirus populations in bovine colostrum, but no decrease occurred in Mycobacterium avium ssp

  9. Evaluating the implementation of environmental review mitigation in local planning and development processes

    SciTech Connect

    Slotterback, Carissa Schively

    2008-11-15

    The implementation of mitigation strategies and outcomes of environmental review remains a challenge for planners and regulators. While the process and content of environmental review is clearly defined, there is often little attention to what happens after the review is completed. This paper presents the results of an evaluation of the implementation of the outcomes of environmental review, specifically mitigation measures designed to respond to environmental impacts identified in the environmental impact analysis. Drawing on previous evaluations of environmental review outcomes and plan implementation, the research provides a methodology for evaluating the implementation of mitigation efforts, points to the challenges associated with implementing the mitigation outcomes of local environmental review in planning and development processes, and identifies opportunities to integrate planning and environmental review processes.

  10. Chlorination processing of local planetary ores for oxygen and metallurgically important metals

    NASA Technical Reports Server (NTRS)

    Lynch, D. C.

    1989-01-01

    The use of chlorine to extract, reclaim, and purify metals has attractive possibilities for extraterrestrial processing of local planetary resources. While a complete cyclic process has been proposed for the recovery of metallurgically significant metals and oxygen, herein the chlorination step of the cycle is examined. An experimental apparatus for reacting refractory materials, such as ilmenite, in a microwave induced plasma is being built. Complex equilibria calculations reveal that stable refractory materials can, under the influence of a plasma, undergo chlorination and yield oxygen as a by-product. These issues and the potential advantages for plasma processing in space are reviewed. Also presented is a discussion of the complex equilibria program used in the analysis.

  11. A Sagnac-Michelson fibre optic interferometer: Signal processing for disturbance localization

    NASA Astrophysics Data System (ADS)

    Kondrat, M.; Szustakowski, M.; Pałka, N.; Ciurapiński, W.; Życzkowski, M.

    2007-09-01

    We present numerical and experimental results on a new generation fibre optic perimeter sensor based on a Sagnac and Michelson interferometers configuration. In particular, an original signal processing scheme is presented. The sensor can detect a potential intruder and determine its position along a protected zone. We propose a localization method that offers the inherent properties of both interferometers. After demodulation of the signals from both interferometers, the obtained amplitude characteristic of the Sagnac interferometer depends on a position of a disturbance along the interferometer, while amplitude characteristic of the Michelson interferometer does not depend on this position. So, quotient of both demodulated characteristics makes it possible to localize the disturbance. During investigations of a laboratory model of the sensor, it was possible to detect the position of the disturbance with a resolution of about 40 m along the 6-km-long sensor.

  12. [Intracellular localization of the processes of biosynthesis and degradation of NADP in skeletal muscle].

    PubMed

    Telepneva, V I; Kariavkina, O E

    1977-01-01

    In studies on intracellular NADP localization the process of NADP biosynthesis was observed in mitochondria and hyaloplasm of rabbit sceletal muscle cells. This synthesis was not found in microsomal and nuclear fractions. The seasonal alterations in the NAD-kinase activity were established: in autumn and winter months NADP synthesis proceeded at the maximal rate in hyaloplasm; in sping months the higher specific activity was observed in mitochondrial fraction. The rate of NADP synthesis was 2-5 times lower in initial and reconstructed (hyaloplasm+cell organelles) homogenate then in hyaloplasm, among the enzymes, degrading the NADP molecule in sceletal muscle, the highest activity was exhibitel by nucleosidase, which was localized mainly in mitochondria and microsomes. Mechanisms for regulation of the rate of NADP synthesis and degradation in cytostructures of rabbit sceletal muscles are discussed.

  13. Relations between Perceptual and Conceptual Scope: How Global versus Local Processing Fits a Focus on Similarity versus Dissimilarity

    ERIC Educational Resources Information Center

    Forster, Jens

    2009-01-01

    Nine studies showed a bidirectional link (a) between a global processing style and generation of similarities and (b) between a local processing style and generation of dissimilarities. In Experiments 1-4, participants were primed with global versus local perception styles and then asked to work on an allegedly unrelated generation task. Across…

  14. Generation of spatiotemporally correlated spike trains and local field potentials using a multivariate autoregressive process.

    PubMed

    Gutnisky, Diego A; Josić, Kresimir

    2010-05-01

    Experimental advances allowing for the simultaneous recording of activity at multiple sites have significantly increased our understanding of the spatiotemporal patterns in neural activity. The impact of such patterns on neural coding is a fundamental question in neuroscience. The simulation of spike trains with predetermined activity patterns is therefore an important ingredient in the study of potential neural codes. Such artificially generated spike trains could also be used to manipulate cortical neurons in vitro and in vivo. Here, we propose a method to generate spike trains with given mean firing rates and cross-correlations. To capture this statistical structure we generate a point process by thresholding a stochastic process that is continuous in space and discrete in time. This stochastic process is obtained by filtering Gaussian noise through a multivariate autoregressive (AR) model. The parameters of the AR model are obtained by a nonlinear transformation of the point-process correlations to the continuous-process correlations. The proposed method is very efficient and allows for the simulation of large neural populations. It can be optimized to the structure of spatiotemporal correlations and generalized to nonstationary processes and spatiotemporal patterns of local field potentials and spike trains.

  15. Synchronized passive imaging of single cavitation events

    NASA Astrophysics Data System (ADS)

    Gateau, Jérôme; Aubry, Jean-François; Pernot, Mathieu; Chauvet, Daurian; Boch, Anne-Laure; Fink, Mathias; Tanter, Mickaël

    2011-09-01

    Passive cavitation detection techniques are usually of relatively low sensitivity to single cavitation events. Moreover, a single-element transducer is generally used, so that the spatial localization of these cavitation events is not possible, or is limited to the probing volume. To both detect and localize single cavitation events over an extended volume, the following experimental set-up has been used and validated: cavitation is induced with a focused single-element transducer (mean frequency 660 kHz, f♯ = 1) driven by a high power (up to 5 kW) electric burst of a few cycles, and the acoustic emission of the bubbles is recorded on a standard linear array (4-7 MHz), mounted on the side of the single element to probe its focal spot. Both the frequencies and the geometry used are appropriate to in vivo implementation. The recording of ultrasonic radio-frequency (RF) data was performed simultaneously on 64 channels of the array and was synchronized with the pulsed excitation. A single cavitation event results in a high frequency and coherent wave front on the RF data. Thanks to synchronization, these RF data are beam-formed to localize the event with a axial resolution of 0.3 mm. A small number of discrete events could also be separated with this method. Besides, B-mode images obtained with the linear array prior to passive detection allowed the positioning of the events within the tissue structure. This technique has been used first ex vivo on freshly harve pig and sheep thigh muscle: with a two cycle excitation, a 9 MPa cavitation threshold was found. Cavitation detection was also achieved in vivo with a five cycle burst excitation in sheep thigh muscle for a peak acoustic pressure of 11MPa. This technique could provide useful information in order to better understand, control and monitor the initiation phase of the histotripsy process.

  16. Local contextual processing of abstract and meaningful real-life images in professional athletes.

    PubMed

    Fogelson, Noa; Fernandez-Del-Olmo, Miguel; Acero, Rafael Martín

    2012-05-01

    We investigated the effect of abstract versus real-life meaningful images from sports on local contextual processing in two groups of professional athletes. Local context was defined as the occurrence of a short predictive series of stimuli occurring before delivery of a target event. EEG was recorded in 10 professional basketball players and 9 professional athletes of individual sports during three sessions. In each session, a different set of visual stimuli were presented: triangles facing left, up, right, or down; four images of a basketball player throwing a ball; four images of a baseball player pitching a baseball. Stimuli consisted of 15 % targets and 85 % of equal numbers of three types of standards. Recording blocks consisted of targets preceded by randomized sequences of standards and by sequences including a predictive sequence signaling the occurrence of a subsequent target event. Subjects pressed a button in response to targets. In all three sessions, reaction times and peak P3b latencies were shorter for predicted targets compared with random targets, the last most informative stimulus of the predictive sequence induced a robust P3b, and N2 amplitude was larger for random targets compared with predicted targets. P3b and N2 peak amplitudes were larger in the professional basketball group in comparison with professional athletes of individual sports, across the three sessions. The findings of this study suggest that local contextual information is processed similarly for abstract and for meaningful images and that professional basketball players seem to allocate more attentional resources in the processing of these visual stimuli.

  17. Global/local processing of hierarchical visual stimuli in a conflict-choice task by capuchin monkeys (Sapajus spp.).

    PubMed

    Truppa, Valentina; Carducci, Paola; De Simone, Diego Antonio; Bisazza, Angelo; De Lillo, Carlo

    2017-03-01

    In the last two decades, comparative research has addressed the issue of how the global and local levels of structure of visual stimuli are processed by different species, using Navon-type hierarchical figures, i.e. smaller local elements that form larger global configurations. Determining whether or not the variety of procedures adopted to test different species with hierarchical figures are equivalent is of crucial importance to ensure comparability of results. Among non-human species, global/local processing has been extensively studied in tufted capuchin monkeys using matching-to-sample tasks with hierarchical patterns. Local dominance has emerged consistently in these New World primates. In the present study, we assessed capuchins' processing of hierarchical stimuli with a method frequently adopted in studies of global/local processing in non-primate species: the conflict-choice task. Different from the matching-to-sample procedure, this task involved processing local and global information retained in long-term memory. Capuchins were trained to discriminate between consistent hierarchical stimuli (similar global and local shape) and then tested with inconsistent hierarchical stimuli (different global and local shapes). We found that capuchins preferred the hierarchical stimuli featuring the correct local elements rather than those with the correct global configuration. This finding confirms that capuchins' local dominance, typically observed using matching-to-sample procedures, is also expressed as a local preference in the conflict-choice task. Our study adds to the growing body of comparative studies on visual grouping functions by demonstrating that the methods most frequently used in the literature on global/local processing produce analogous results irrespective of extent of the involvement of memory processes.

  18. Subcellular localization of glycosidases and glycosyltransferases involved in the processing of N-linked oligosaccharides

    SciTech Connect

    Sturm, A.; Johnson, K.D.; Szumilo, T.; Elbein, A.D.; Chrispeels, M.J.

    1987-11-01

    Using isopycnic sucrose gradients, we have ascertained the subcellular location of several enzymes involved in the processing of the N-linked oligosaccharides of glycoproteins in developing cotyledons of the common bean, Phaseolus vulgaris. All are localized in the endoplasmic reticulum (ER) or Golgi complex as determined by co-sedimentation with the ER marker, NADH-cytochrome c reductase, or the Golgi marker, glucan synthase I. Glucosidase activity, which removes glucose residues from Glc/sub 3/Man/sub 9/(GlcNAc)/sub 2/, was found exclusively in the ER. All other processing enzymes, which act subsequent to the glucose trimming steps, are associates with Golgi. These include mannosidase I (removes 1-2 mannose residues from Man/sub 6-9/(GlcNAc)/sub 2/), mannosidase II (removes mannose residues from GlcNAcMan/sub 5/(GlcNAc)/sub 2/), and fucosyltransferase (transfers a fucose residue to the Asn-linked GlcNAc of appropriate glycans). The authors have previously reported the localization of two other glycan modifying enzymes (GlcNAc-transferase and xylosyltranferase activities) in the Golgi complex. Attempts at subfractionation of the Golgi fraction on shallow sucrose gradients yielded similar patterns of distribution for all the Golgi processing enzymes. Subfractionation on Percoll gradients resulted in two peaks of the Golgi marker enzyme inosine diphosphatase, whereas the glycan processing enzymes were all enriched in the peak of lower density. These results do not lend support to the hypothesis that N-linked oligosaccharide processing enzymes are associated with Golgi cisternae of different densities.

  19. Are the autism and positive schizotypy spectra diametrically opposed in local versus global processing?

    PubMed

    Russell-Smith, Suzanna N; Maybery, Murray T; Bayliss, Donna M

    2010-08-01

    Crespi and Badcock (2008) proposed that autism and psychosis represent two extremes on a cognitive spectrum with normality at its center. Their specific claim that autistic and positive schizophrenia traits contrastingly affect preference for local versus global processing was investigated by examining Embedded Figures Test performance in two groups of students separated on autistic-like traits but matched on positive schizotypy traits, and two groups separated on positive schizotypy traits but matched on autistic-like traits (n = 20 per group). Consistent with their theory, higher levels of autistic-like traits were associated with faster identification of hidden figures, whereas higher levels of positive schizotypy traits were associated with slower identification.

  20. Improvement of bias-stability in amorphous-indium-gallium-zinc-oxide thin-film transistors by using solution-processed Y{sub 2}O{sub 3} passivation

    SciTech Connect

    An, Sungjin; Mativenga, Mallory; Kim, Youngoo; Jang, Jin

    2014-08-04

    We demonstrate back channel improvement of back-channel-etch amorphous-indium-gallium-zinc-oxide (a-IGZO) thin-film transistors by using solution-processed yttrium oxide (Y{sub 2}O{sub 3}) passivation. Two different solvents, which are acetonitrile (35%) + ethylene glycol (65%), solvent A and deionized water, solvent B are investigated for the spin-on process of the Y{sub 2}O{sub 3} passivation—performed after patterning source/drain (S/D) Mo electrodes by a conventional HNO{sub 3}-based wet-etch process. Both solvents yield devices with good performance but those passivated by using solvent B exhibit better light and bias stability. Presence of yttrium at the a-IGZO back interface, where it occupies metal vacancy sites, is confirmed by X-ray photoelectron spectroscopy. The passivation effect of yttrium is more significant when solvent A is used because of the existence of more metal vacancies, given that the alcohol (65% ethylene glycol) in solvent A may dissolve the metal oxide (a-IGZO) through the formation of alkoxides and water.

  1. Springtime cloud properties in the Taiwan Strait: synoptic controls and local processes

    NASA Astrophysics Data System (ADS)

    Kueh, Mien-Tze; Lin, Pay-Liam

    2014-05-01

    This paper examines the springtime cloud properties in the Taiwan Strait (TS), with emphases on their dependence on synoptic controls and local processes, using a suite of in situ and remote sensing observations. Cloud properties in the TS are inferred from a combination of MODIS and in situ observations and further classified into two synoptic conditions: continental cold air surge and frontal system. The study reveals a predominance of synoptic-scale controls in regulating the cloud properties in the TS. The sensitivity of clouds to the local thermodynamic mechanisms as well as the underlying surface conditions is fundamentally dependent on synoptic-scale flow patterns. The springtime clouds over the TS are commonly a mixture of stratocumulus and alto clouds. More precisely, there is a preponderance of stratocumulus over the strait. A preferential occupancy of stratiform alto clouds is recognized during cold air surge, whereas vertical development of cloud layers (mostly the stratocumulus) is commonly observed with frontal passage. The most distinct difference between the local clouds formation associated with the two synoptic conditions is the suppression of very low cloud and fog along with cold air surge. Stratus clouds and fog are present within the northward prefrontal airflow from warmer to colder water sites, along with an increase in stability relating to lower altitudes of boundary layer clouds. Although the rainfall occurrences are about the same for both synoptic conditions, the frontal rain amounts are larger on average.

  2. Neural Processes in the Human Temporoparietal Cortex Separated by Localized Independent Component Analysis.

    PubMed

    Igelström, Kajsa M; Webb, Taylor W; Graziano, Michael S A

    2015-06-24

    The human temporoparietal junction (TPJ) is a topic of intense research. Imaging studies have identified TPJ activation in association with many higher-order functions such as theory-of-mind, episodic memory, and attention, causing debate about the distribution of different processes. One major challenge is the lack of consensus about the anatomical location and extent of the TPJ. Here, we address this problem using data-driven analysis to test the hypothesis that the bilateral TPJ can be parcellated into subregions. We applied independent component analysis (ICA) to task-free fMRI data within a local region around the bilateral TPJ, iterating the ICA at multiple model orders and in several datasets. The localized analysis allowed finer separation of processes and the use of multiple dimensionalities provided qualitative information about lateralization. We identified four subdivisions that were bilaterally symmetrical and one that was right biased. To test whether the independent components (ICs) reflected true subdivisions, we performed functional connectivity analysis using the IC coordinates as seeds. This confirmed that the subdivisions belonged to distinct networks. The right-biased IC was connected with a network often associated with attentional processing. One bilateral subdivision was connected to sensorimotor regions and another was connected to auditory regions. One subdivision that presented as distinct left- and right-biased ICs was connected to frontoparietal regions. Another subdivision that also had left- and right-biased ICs was connected to social or default mode networks. Our results show that the TPJ in both hemispheres hosts multiple neural processes with connectivity patterns consistent with well developed specialization and lateralization.

  3. Effects of local electric surface potential on holes charging process in uncapped germanium nanocrystal

    SciTech Connect

    Marchand, Aude; El Hdiy, Abdelillah

    2015-04-21

    The charging kinetics of holes are investigated in an uncapped Ge nanocrystal by the use of the nano-electron beam induced current technique. The charging process is studied under zero volt or under an appropriate electric field. The investigation is repeated many times on the same nanocrystal and on others in the same sample to attest of the reproducibility of the results. At 0 V, the cycles of charging kinetics are superimposed and are in a steady state, but an instantaneous local and negative surface potential, established in the nanocrystal at the beginning of the kinetics, slows down the holes charging process. Under an external field, the energy band bending accentuation affects the holes charging time constants. As a result, the holes charging cycles weakly affect the electrical performance of the thin oxide as is indicated by the value of the measured local resistivity of 6 × 10{sup 10}–10{sup 11} Ω cm, which is relatively lower than that of the thick thermal oxide.

  4. A Multi-Objective Compounded Local Mobile Cloud Architecture Using Priority Queues to Process Multiple Jobs.

    PubMed

    Wei, Xiaohui; Sun, Bingyi; Cui, Jiaxu; Xu, Gaochao

    2016-01-01

    As a result of the greatly increased use of mobile devices, the disadvantages of portable devices have gradually begun to emerge. To solve these problems, the use of mobile cloud computing assisted by cloud data centers has been proposed. However, cloud data centers are always very far from the mobile requesters. In this paper, we propose an improved multi-objective local mobile cloud model: Compounded Local Mobile Cloud Architecture with Dynamic Priority Queues (LMCpri). This new architecture could briefly store jobs that arrive simultaneously at the cloudlet in different priority positions according to the result of auction processing, and then execute partitioning tasks on capable helpers. In the Scheduling Module, NSGA-II is employed as the scheduling algorithm to shorten processing time and decrease requester cost relative to PSO and sequential scheduling. The simulation results show that the number of iteration times that is defined to 30 is the best choice of the system. In addition, comparing with LMCque, LMCpri is able to effectively accommodate a requester who would like his job to be executed in advance and shorten execution time. Finally, we make a comparing experiment between LMCpri and cloud assisting architecture, and the results reveal that LMCpri presents a better performance advantage than cloud assisting architecture.

  5. Revisiting Gaussian Process Regression Modeling for Localization in Wireless Sensor Networks.

    PubMed

    Richter, Philipp; Toledano-Ayala, Manuel

    2015-09-08

    Signal strength-based positioning in wireless sensor networks is a key technology for seamless, ubiquitous localization, especially in areas where Global Navigation Satellite System (GNSS) signals propagate poorly. To enable wireless local area network (WLAN) location fingerprinting in larger areas while maintaining accuracy, methods to reduce the effort of radio map creation must be consolidated and automatized. Gaussian process regression has been applied to overcome this issue, also with auspicious results, but the fit of the model was never thoroughly assessed. Instead, most studies trained a readily available model, relying on the zero mean and squared exponential covariance function, without further scrutinization. This paper studies the Gaussian process regression model selection for WLAN fingerprinting in indoor and outdoor environments. We train several models for indoor/outdoor- and combined areas; we evaluate them quantitatively and compare them by means of adequate model measures, hence assessing the fit of these models directly. To illuminate the quality of the model fit, the residuals of the proposed model are investigated, as well. Comparative experiments on the positioning performance verify and conclude the model selection. In this way, we show that the standard model is not the most appropriate, discuss alternatives and present our best candidate.

  6. A Multi-Objective Compounded Local Mobile Cloud Architecture Using Priority Queues to Process Multiple Jobs

    PubMed Central

    Wei, Xiaohui; Sun, Bingyi; Cui, Jiaxu; Xu, Gaochao

    2016-01-01

    As a result of the greatly increased use of mobile devices, the disadvantages of portable devices have gradually begun to emerge. To solve these problems, the use of mobile cloud computing assisted by cloud data centers has been proposed. However, cloud data centers are always very far from the mobile requesters. In this paper, we propose an improved multi-objective local mobile cloud model: Compounded Local Mobile Cloud Architecture with Dynamic Priority Queues (LMCpri). This new architecture could briefly store jobs that arrive simultaneously at the cloudlet in different priority positions according to the result of auction processing, and then execute partitioning tasks on capable helpers. In the Scheduling Module, NSGA-II is employed as the scheduling algorithm to shorten processing time and decrease requester cost relative to PSO and sequential scheduling. The simulation results show that the number of iteration times that is defined to 30 is the best choice of the system. In addition, comparing with LMCque, LMCpri is able to effectively accommodate a requester who would like his job to be executed in advance and shorten execution time. Finally, we make a comparing experiment between LMCpri and cloud assisting architecture, and the results reveal that LMCpri presents a better performance advantage than cloud assisting architecture. PMID:27419854

  7. Revisiting Gaussian Process Regression Modeling for Localization in Wireless Sensor Networks

    PubMed Central

    Richter, Philipp; Toledano-Ayala, Manuel

    2015-01-01

    Signal strength-based positioning in wireless sensor networks is a key technology for seamless, ubiquitous localization, especially in areas where Global Navigation Satellite System (GNSS) signals propagate poorly. To enable wireless local area network (WLAN) location fingerprinting in larger areas while maintaining accuracy, methods to reduce the effort of radio map creation must be consolidated and automatized. Gaussian process regression has been applied to overcome this issue, also with auspicious results, but the fit of the model was never thoroughly assessed. Instead, most studies trained a readily available model, relying on the zero mean and squared exponential covariance function, without further scrutinization. This paper studies the Gaussian process regression model selection for WLAN fingerprinting in indoor and outdoor environments. We train several models for indoor/outdoor- and combined areas; we evaluate them quantitatively and compare them by means of adequate model measures, hence assessing the fit of these models directly. To illuminate the quality of the model fit, the residuals of the proposed model are investigated, as well. Comparative experiments on the positioning performance verify and conclude the model selection. In this way, we show that the standard model is not the most appropriate, discuss alternatives and present our best candidate. PMID:26370996

  8. The bud break process and its variation among local populations of boreal black spruce

    PubMed Central

    Rossi, Sergio; Bousquet, Jean

    2014-01-01

    Phenology of local populations can exhibit adaptations to the current environmental conditions resulting from a close interaction between climate and genotype. The bud break process and its variations among populations were analyzed in greenhouse by monitoring the growth resumption in black spruce [Picea mariana (Mill.) BSP] seedlings originating from seeds of five stands across the closed boreal forest in Quebec, Canada. Bud break lasted 15 days and occurred earlier and quicker in northern provenances. Provenance explained between 10.2 and 32.3% of the variance in bud break, while the families accounted for a smaller but still significant part of the variance. The late occurrence of one phenological phase corresponded to a delayed occurrence of the others according to linear relationships. A causal model was proposed in the form of a chain of events with each phase of bud break being related to the previous and successive one, while no link was observed between non-adjacent phases. The adaptation of black spruce populations along the latitudinal gradient points toward a strategy based on rapid physiological processes triggered by temperature increase inducing high metabolic activity. The variation observed in bud break reflects an evolutionary trade-off between maximization of security and taking advantage of the short growing season. This work provides evidence of the phenological adaptations of black spruce to its local environmental conditions while retaining sizeable genetic diversity within populations. Because of the multigenic nature of phenology, this diversity should provide some raw material for adaptation to changing local environmental conditions. PMID:25389430

  9. [Anti-doping policy development process in the sports world (1968~1999): focusing on IOC activities and passive response from Korea].

    PubMed

    Hwang, Eui-Ryong; Kim, Tae-Young

    2014-08-01

    athletes experienced doping test directly, yet education about doping was limited. However, some national team level athletes tested positive on the doping test and underwent disciplinary action. In addition, athletic federation or leaders acquiesced athletes doping made secretly; this indicated that South Korea was also not free from doping. It was found that Korea world of sports showed very passive countermeasures and development process.

  10. Citric Acid Passivation of Stainless Steel

    NASA Technical Reports Server (NTRS)

    Yasensky, David; Reali, John; Larson, Chris; Carl, Chad

    2009-01-01

    Passivation is a process for cleaning and providing corrosion protection for stainless steel. Currently, on Kennedy Space Center (KSC), only parts passivated with nitric acid are acceptable for use. KSC disposes of approximately 125gal of concentrated nitric acid per year, and receives many parts from vendors who must also dispose of used nitric acid. Unfortunately, nitric acid presents health and environmental hazards. As a result, several recent industry studies have examined citric acid as an alternative. Implementing a citric acid-based passivation procedure would improve the health and environmental safety aspects of passivation process. However although there is a lack of published studies that conclusively prove citric acid is a technically sound passivation agent. In 2007, NASA's KSC Materials Advisory Working Group requested the evaluation of citric acid in place of nitric acid for passivation of parts at KSC. United Space Alliance Materials & Processes engineers have developed a three-phase test plan to evaluate citric acid as an alternative to nitric acid on three stainless steels commonly used at KSC: UNS S30400, S41000, and S17400. Phases 1 and 2 will produce an optimized citric acid treatment based on results from atmospheric exposure at NASA's Beach Corrosion Facility. Phase 3 will compare the optimized solution(s) with nitric acid treatments. If the results indicate that citric acid passivates as well or better than nitric acid, NASA intends to approve this method for parts used at the Kennedy Space Center.

  11. The forest or the trees: preference for global over local image processing is reversed by prior experience in honeybees.

    PubMed

    Avarguès-Weber, Aurore; Dyer, Adrian G; Ferrah, Noha; Giurfa, Martin

    2015-01-22

    Traditional models of insect vision have assumed that insects are only capable of low-level analysis of local cues and are incapable of global, holistic perception. However, recent studies on honeybee (Apis mellifera) vision have refuted this view by showing that this insect also processes complex visual information by using spatial configurations or relational rules. In the light of these findings, we asked whether bees prioritize global configurations or local cues by setting these two levels of image analysis in competition. We trained individual free-flying honeybees to discriminate hierarchical visual stimuli within a Y-maze and tested bees with novel stimuli in which local and/or global cues were manipulated. We demonstrate that even when local information is accessible, bees prefer global information, thus relying mainly on the object's spatial configuration rather than on elemental, local information. This preference can be reversed if bees are pre-trained to discriminate isolated local cues. In this case, bees prefer the hierarchical stimuli with the local elements previously primed even if they build an incorrect global configuration. Pre-training with local cues induces a generic attentional bias towards any local elements as local information is prioritized in the test, even if the local cues used in the test are different from the pre-trained ones. Our results thus underline the plasticity of visual processing in insects and provide new insights for the comparative analysis of visual recognition in humans and animals.

  12. The forest or the trees: preference for global over local image processing is reversed by prior experience in honeybees

    PubMed Central

    Avarguès-Weber, Aurore; Dyer, Adrian G.; Ferrah, Noha; Giurfa, Martin

    2015-01-01

    Traditional models of insect vision have assumed that insects are only capable of low-level analysis of local cues and are incapable of global, holistic perception. However, recent studies on honeybee (Apis mellifera) vision have refuted this view by showing that this insect also processes complex visual information by using spatial configurations or relational rules. In the light of these findings, we asked whether bees prioritize global configurations or local cues by setting these two levels of image analysis in competition. We trained individual free-flying honeybees to discriminate hierarchical visual stimuli within a Y-maze and tested bees with novel stimuli in which local and/or global cues were manipulated. We demonstrate that even when local information is accessible, bees prefer global information, thus relying mainly on the object's spatial configuration rather than on elemental, local information. This preference can be reversed if bees are pre-trained to discriminate isolated local cues. In this case, bees prefer the hierarchical stimuli with the local elements previously primed even if they build an incorrect global configuration. Pre-training with local cues induces a generic attentional bias towards any local elements as local information is prioritized in the test, even if the local cues used in the test are different from the pre-trained ones. Our results thus underline the plasticity of visual processing in insects and provide new insights for the comparative analysis of visual recognition in humans and animals. PMID:25473017

  13. Passive Localization of Underwater Acoustic Beacons

    DTIC Science & Technology

    1993-09-01

    maxtime) TickCounto; aborto ; FSRead(gASerRefln,&numCharln,&addressBuf); TalkSail(’O); iistart the PTR’s data collecticn DrawString(w\\p: H) I display a...34); aborto ; EventLoopO; II main execution loop RAMSDClose(sPortA); HI must close the RAM Drivers before shutdown 193 free(gw); //must release the...kNumExp+l),sizeof(double)); if(wtrue ==NULL) DrawString("\\pCan’t allocate memory for data collection!!! ); aborto ; Nvmeas = calloc(3L*(kStep~kNumExp+l

  14. Going beyond exposure to local news media: an information-processing examination of public perceptions of food safety.

    PubMed

    Fleming, Kenneth; Thorson, Esther; Zhang, Yuyan

    2006-12-01

    The relationship between local news media and public perceptions of food safety was examined in a statewide telephone survey (n = 524). The theoretical framework of the study was based on a review of the social and psychological factors that affect public concerns about food safety, the relationship between mass communication and risk perception, and the thesis of information-processing strategies and its impact on learning from the news. The results show that information-processing strategies substantially mediated the relationship between local news media and public perceptions of food safety, with elaborative processing being more influential than active reflection in people's learning from the news media. Attention to local television had an independent effect, after demographics, awareness of food safety problems, and perceived safety of local food supply were statistically controlled. Other important predictors included gender, education, ethnicity, and perceived safety of local food supply.

  15. Immunizations: Active vs. Passive

    MedlinePlus

    ... a certain type of wild animal bites a child. Passive immunizations for hepatitis A (gamma globulin) may be helpful ... A is common. They are typically given before children or adults leave on their ... active vaccination is preferable. Keep in mind that passive immunizations ...

  16. Passive magnetic bearing configurations

    DOEpatents

    Post, Richard F [Walnut Creek, CA

    2011-01-25

    A journal bearing provides vertical and radial stability to a rotor of a passive magnetic bearing system when the rotor is not rotating and when it is rotating. In the passive magnetic bearing system, the rotor has a vertical axis of rotation. Without the journal bearing, the rotor is vertically and radially unstable when stationary, and is vertically stable and radially unstable when rotating.

  17. LASL passive program

    SciTech Connect

    Neeper, D.A.

    1980-01-01

    Recent accomplishments are outlined on the following tasks: (1) solar load ratio for sunspaces; (2) thermal performance of components and buildings; (3) convective loop test; (4) similarity study of interzone convection; (5) evaluation of phase-change thermal storage; (6) off-peak electrical auxiliary heating; (7) passive solar design handbook; (8) program support to DOE; and (9) passive cooling for residences. (WHK)

  18. Passive solar construction handbook

    SciTech Connect

    Levy, E.; Evans, D.; Gardstein, C.

    1981-08-01

    Many of the basic elements of passive solar design are reviewed. The unique design constraints presented in passive homes are introduced and many of the salient issues influencing design decisions are described briefly. Passive solar construction is described for each passive system type: direct gain, thermal storage wall, attached sunspace, thermal storage roof, and convective loop. For each system type, important design and construction issues are discussed and case studies illustrating designed and built examples of the system type are presented. Construction details are given and construction and thermal performance information is given for the materials used in collector components, storage components, and control components. Included are glazing materials, framing systems, caulking and sealants, concrete masonry, concrete, brick, shading, reflectors, and insulators. The Load Collector Ratio method for estimating passive system performance is appended, and other analysis methods are briefly summarized. (LEW)

  19. Localized electro-thermal processing: a new route to the patterning of magnetic recording media.

    PubMed

    Aziz, M M; Newman, D M; Sidwell, A; Wears, M L; Wright, C D

    2010-12-17

    Previous reports have detailed the fabrication of media able to support high density magnetic recording in both longitudinal and perpendicular formats by the global rapid thermal processing of sputtered non-magnetic precursor films. During processing in this manner a magnetic element is released from its nitride and agglomerates to form a random near mono-dispersion of magnetic nano-particles. Here we explore, primarily through modelling and simulation, the feasibility of processing similarly formulated precursor media not globally but locally. We investigate the potential of using conducting nano-probe tips to produce, via electro-thermal (Joule) heating, a nano-patterned recording medium in the form of regular arrays of magnetic islands in a non-magnetic host. In the first instance we concentrate on the simplest cobalt based precursor medium for which both initial simulation and experimental studies indicate the formation of magnetic islands with dimensions of the order of the tip diameter; this is relatively straightforward. The results signify that if practical production scenarios can be devised to produce technologically significant areas of recording media by the rapid multi-probe repetition of this technique, then processing in this manner offers a promising route to areal recording densities of perhaps 5 Terabit/in(2) even with the simplest cobalt media. We also note that the electro-thermal processing method is potentially extendable to the production of a wide variety of magnetic materials (e.g. PtCo, FeCo, NiFe alloys) and, applied via electrical nano-imprinting type techniques, to the production of a wide variety of patterned structures.

  20. Regulation of the processivity and intracellular localization of Saccharomyces cerevisiae dynein by dynactin

    PubMed Central

    Kardon, Julia R.; Reck-Peterson, Samara L.; Vale, Ronald D.

    2009-01-01

    Dynactin, a large multisubunit complex, is required for intracellular transport by dynein; however, its cellular functions and mechanism of action are not clear. Prior studies suggested that dynactin increases dynein processivity by tethering the motor to the microtubule through its own microtubule binding domains. However, this hypothesis could not be tested without a recombinant source of dynactin. Here, we have produced recombinant dynactin and dynein in Saccharomyces cerevisiae, and examined the effect of dynactin on dynein in single-molecule motility assays. We show that dynactin increases the run length of single dynein motors, but does not alter the directionality of dynein movement. Enhancement of dynein processivity by dynactin does not require the microtubule (MT) binding domains of Nip100 (the yeast p150Glued homolog). Dynactin lacking these MT binding domains also supports the proper localization and function of dynein during nuclear segregation in vivo. Instead, a segment of the coiled-coil of Nip100 is required for these activities. Our results directly demonstrate that dynactin increases the processivity of dynein through a mechanism independent of microtubule tethering. PMID:19293377

  1. Hi-fidelity multi-scale local processing for visually optimized far-infrared Herschel images

    NASA Astrophysics Data System (ADS)

    Li Causi, G.; Schisano, E.; Liu, S. J.; Molinari, S.; Di Giorgio, A.

    2016-07-01

    In the context of the "Hi-Gal" multi-band full-plane mapping program for the Galactic Plane, as imaged by the Herschel far-infrared satellite, we have developed a semi-automatic tool which produces high definition, high quality color maps optimized for visual perception of extended features, like bubbles and filaments, against the high background variations. We project the map tiles of three selected bands onto a 3-channel panorama, which spans the central 130 degrees of galactic longitude times 2.8 degrees of galactic latitude, at the pixel scale of 3.2", in cartesian galactic coordinates. Then we process this image piecewise, applying a custom multi-scale local stretching algorithm, enforced by a local multi-scale color balance. Finally, we apply an edge-preserving contrast enhancement to perform an artifact-free details sharpening. Thanks to this tool, we have thus produced a stunning giga-pixel color image of the far-infrared Galactic Plane that we made publicly available with the recent release of the Hi-Gal mosaics and compact source catalog.

  2. Judging sound rotation when listeners and sounds rotate: Sound source localization is a multisystem process.

    PubMed

    Yost, William A; Zhong, Xuan; Najam, Anbar

    2015-11-01

    In four experiments listeners were rotated or were stationary. Sounds came from a stationary loudspeaker or rotated from loudspeaker to loudspeaker around an azimuth array. When either sounds or listeners rotate the auditory cues used for sound source localization change, but in the everyday world listeners perceive sound rotation only when sounds rotate not when listeners rotate. In the everyday world sound source locations are referenced to positions in the environment (a world-centric reference system). The auditory cues for sound source location indicate locations relative to the head (a head-centric reference system), not locations relative to the world. This paper deals with a general hypothesis that the world-centric location of sound sources requires the auditory system to have information about auditory cues used for sound source location and cues about head position. The use of visual and vestibular information in determining rotating head position in sound rotation perception was investigated. The experiments show that sound rotation perception when sources and listeners rotate was based on acoustic, visual, and, perhaps, vestibular information. The findings are consistent with the general hypotheses and suggest that sound source localization is not based just on acoustics. It is a multisystem process.

  3. Influence of etch process on contact hole local critical dimension uniformity in extreme-ultraviolet lithography

    NASA Astrophysics Data System (ADS)

    Lorusso, Gian F.; Mao, Ming; Reijnen, Liesbeth; Viatkina, Katja; Knops, Roel; Rispens, Gijsbert; Fliervoet, Timon

    2015-03-01

    Contact Hole (CH) Local Critical Dimension Uniformity (LCDU) has a direct impact on device performance. As a consequence, being able to understand and quantifying the different LCDU contributors and the way they evolve during the various process steps is critical. In this work the impact of etch process on LCDU for different resists and stacks is investigated on ASML NXE:3100 and NXE:3300. LCDU is decomposed into shot noise, mask, and metrology components. The design of the experiment is optimized to minimize the decomposition error. CD and LCDU are monitored and found to be stable. We observed that the net effect of the etch process is to improve LCDU, although the final LCDU is both stack- and resist-dependent. Different resists demonstrate the same LCDU improvement, so that the LCDU after etch will depend on the initial resist performance. Using a stack different from the one used to set up the etch process can undermine the LCDU improvement. The impact of the various etch steps is investigated in order to identify the physical mechanisms responsible for the LCDU improvement through etch. Both top-down and cross section Scanning Electron Microscopy (SEM) are used. The step-by-step analysis of the etch process showed that the main LCDU improvement is achieved during oxide etch, while the other process steps are either ineffective or detrimental in terms of LCDU. The main cause of the LCDU improvement is then attributed to the polymerization of the CH surface happening during the oxide etch. Finally, the LCDU improvement caused by the etch process is investigated as a function of the initial LCDU after litho in a relatively broad range (2-15nm). The ratio between LCDU after litho over LCDU after etch is investigated as a function of the initial LCDU after litho for two different resists. The results indicate that the impact of etch on LCDU is characterized by a single curve, specific to the etch process in use and independent of the resist type. In addition, we

  4. Geothermal energy development in Washington State. A guide to the federal, state and local regulatory process

    SciTech Connect

    Bloomquist, R.G.; Simpson, S.J.

    1986-03-01

    Washington State's geothermal potential is wide spread. Hot springs and five strato volcanoes existing throughout the Cascade Range, limited hot spring activity on the Olympic Peninsula, and broad reaching, low temperature geothermal resources found in the Columbia Basin comprise the extent of Washington's known geothermal resources. Determination of resource ownership is the first step in proceeding with geothermal exploration and development activities. The federal and state processes are examined from pre-lease activity through leasing and post-lease development concerns. Plans, permits, licenses, and other requirements are addressed for the federal, state, and local level. Lease, permit, and other forms for a number of geothermal exploration and development activities are included. A map of public lands and another displaying the measured geothermal resources throughout the state are provided.

  5. DBSproc: An open source process for DBS electrode localization and tractographic analysis.

    PubMed

    Lauro, Peter M; Vanegas-Arroyave, Nora; Huang, Ling; Taylor, Paul A; Zaghloul, Kareem A; Lungu, Codrin; Saad, Ziad S; Horovitz, Silvina G

    2016-01-01

    Deep brain stimulation (DBS) is an effective surgical treatment for movement disorders. Although stimulation sites for movement disorders such as Parkinson's disease are established, the therapeutic mechanisms of DBS remain controversial. Recent research suggests that specific white-matter tract and circuit activation mediates symptom relief. To investigate these questions, we have developed a patient-specific open-source software pipeline called 'DBSproc' for (1) localizing DBS electrodes and contacts from postoperative CT images, (2) processing structural and diffusion MRI data, (3) registering all images to a common space, (4) estimating DBS activation volume from patient-specific voltage and impedance, and (5) understanding the DBS contact-brain connectivity through probabilistic tractography. In this paper, we explain our methodology and provide validation with anatomical and tractographic data. This method can be used to help investigate mechanisms of action of DBS, inform surgical and clinical assessments, and define new therapeutic targets.

  6. Regulation of mammalian microRNA processing and function by cellular signaling and subcellular localization

    PubMed Central

    Smalheiser, Neil R.

    2008-01-01

    For many microRNAs, in many normal tissues and in cancer cells, the cellular levels of mature microRNAs are not simply determined by transcription of microRNA genes. This mini-review will discuss how microRNA biogenesis and function can be regulated by various nuclear and cytoplasmic processing events, including emerging evidence that microRNA pathway components can be selectively regulated by control of their subcellular localization and by modifications that occur during dynamic cellular signaling. Finally, I will briefly summarize studies of microRNAs in synaptic fractions of adult mouse forebrain, which may serve as a model for other cell types as well. PMID:18433727

  7. Non-Local Means Inpainting of MS Lesions in Longitudinal Image Processing

    PubMed Central

    Guizard, Nicolas; Nakamura, Kunio; Coupé, Pierrick; Fonov, Vladimir S.; Arnold, Douglas L.; Collins, D. Louis

    2015-01-01

    In medical imaging, multiple sclerosis (MS) lesions can lead to confounding effects in automatic morphometric processing tools such as registration, segmentation and cortical extraction, and subsequently alter individual longitudinal measurements. Multiple magnetic resonance imaging (MRI) inpainting techniques have been proposed to decrease the impact of MS lesions in medical image processing, however, most of these methods make the assumption that lesions only affect white matter. Here, we propose a method to fill lesion regions using the patch-based non-local mean (NLM) strategy. The method consists of a hierarchical concentric filling strategy after identification of the lesion region. The lesion is filled iteratively, based on the surrounding tissue intensity, using an onion peel strategy. This concentric technique presents the advantage of preserving the local information and therefore the continuity of the anatomy and does not require identification of any a priori normal brain tissues. The method is first evaluated on 20 healthy subjects with simulated artificial MS lesions where we assessed our technique by measuring the peak signal-to-noise ratio (PSNR) of the images with inpainted lesion and the original healthy images. Second, in order to assess the impact of lesion filling on longitudinal image analyses, we performed a power analysis with sample size estimation to evaluate brain atrophy and ventricular growth in patients with MS. The method was compared to two different publicly available methods (FSL lesion fill and Lesion LEAP) and a more classic method, which fills the region with intensities similar to that of the surrounding healthy white matter tissue or mask the lesions. The proposed method was shown to exceed the other methods in reproducing the fidelity of healthy subject images where the lesions were inpainted. The method also improved the power to detect brain atrophy or ventricular growth by decreasing the sample size by 25% in the presence

  8. Non-Local Means Inpainting of MS Lesions in Longitudinal Image Processing.

    PubMed

    Guizard, Nicolas; Nakamura, Kunio; Coupé, Pierrick; Fonov, Vladimir S; Arnold, Douglas L; Collins, D Louis

    2015-01-01

    In medical imaging, multiple sclerosis (MS) lesions can lead to confounding effects in automatic morphometric processing tools such as registration, segmentation and cortical extraction, and subsequently alter individual longitudinal measurements. Multiple magnetic resonance imaging (MRI) inpainting techniques have been proposed to decrease the impact of MS lesions in medical image processing, however, most of these methods make the assumption that lesions only affect white matter. Here, we propose a method to fill lesion regions using the patch-based non-local mean (NLM) strategy. The method consists of a hierarchical concentric filling strategy after identification of the lesion region. The lesion is filled iteratively, based on the surrounding tissue intensity, using an onion peel strategy. This concentric technique presents the advantage of preserving the local information and therefore the continuity of the anatomy and does not require identification of any a priori normal brain tissues. The method is first evaluated on 20 healthy subjects with simulated artificial MS lesions where we assessed our technique by measuring the peak signal-to-noise ratio (PSNR) of the images with inpainted lesion and the original healthy images. Second, in order to assess the impact of lesion filling on longitudinal image analyses, we performed a power analysis with sample size estimation to evaluate brain atrophy and ventricular growth in patients with MS. The method was compared to two different publicly available methods (FSL lesion fill and Lesion LEAP) and a more classic method, which fills the region with intensities similar to that of the surrounding healthy white matter tissue or mask the lesions. The proposed method was shown to exceed the other methods in reproducing the fidelity of healthy subject images where the lesions were inpainted. The method also improved the power to detect brain atrophy or ventricular growth by decreasing the sample size by 25% in the presence

  9. A program for passively tracking a target using an array of sensors

    SciTech Connect

    Buhl, M.R.

    1993-01-01

    The problem of passively tracking a moving signal source has importance in a variety of applications such as radar, sonar, seismology, and radio astronomy. In many applications, only limited information is available about the signal source. It will be assumed here that only the signals which are detected by the sensors and the velocity of the source signal are known. The objective of this document is to present a program which passively tracks a target using an array of sensors. This program is available in MATLAB, version 3.5. The algorithm which is implemented consists of three main parts: time delay estimation, passive localization, and data post processing. Each of these parts are discussed, and the mathematical foundation for their solution given. Following, this the organization of the program is presented, and an example of its usage is given.

  10. Can the combination of localized "proliferative therapy" with "minor ozonated autohemotherapy" restore the natural healing process?

    PubMed

    Gracer, R I; Bocci, V

    2005-01-01

    Regenerative injection therapy (RIT), also known as proliferative therapy, has been used for over 30 years in the USA in patients with spinal and peripheral joint and ligamentous pathologies. It involves the injection of mildly irritating medications onto ligaments and tendons, most commonly at origins and insertions. These injections cause a mild inflammatory response which "turns on" the normal healing process and results in the regeneration of these structures. At the same time they strengthen and become less sensitive to pain through a combination of neurolysis of small nerve fibers (C-fibers) and increased stability of the underlying structures. Oxygen/ozone therapy is a well established complementary therapy practiced in many European countries. The ozone dissolves in body fluids and immediately reacts with biomolecules generating messengers responsible for biological and therapeutic activities. This results in an anti inflammatory response, which also results in a similar trophic reaction to that of RIT. It is logical to expect that combining these two modalities would result in enhanced healing and therefore improved clinical outcomes. Oxygen/ozone therapy, accomplished by autohemotherapy (AHT), is performed by either administering ozonated blood intravenously (Major AHT) or via intramuscular route (Minor AHT). These procedures result in stimulation of the immune and healing systems. Our concept is that the local injection of this activated blood injected directly to the ligamentous areas that are also being treated with RIT will act as a direct stimulation to the healing process. In addition, combining this with intravenous major AHT should stimulate the immune system to augment and support this process. RIT and oxygen/ozone therapy have been extensively studied separately. We propose a study of lumbosacral ligamentous pain to explore this therapeutic combination. We hope that this paper will stimulate general interest in this area of medicine and result

  11. Molecular dynamics study of solid-liquid heat transfer and passive liquid flow

    NASA Astrophysics Data System (ADS)

    Yesudasan Daisy, Sumith

    High heat flux removal is a challenging problem in boilers, electronics cooling, concentrated photovoltaic and other power conversion devices. Heat transfer by phase change is one of the most efficient mechanisms for removing heat from a solid surface. Futuristic electronic devices are expected to generate more than 1000 W/cm2 of heat. Despite the advancements in microscale and nanoscale manufacturing, the maximum passive heat flux removal has been 300 W/cm2 in pool boiling. Such limitations can be overcome by developing nanoscale thin-film evaporation based devices, which however require a better understanding of surface interactions and liquid vapor phase change process. Evaporation based passive flow is an inspiration from the transpiration process that happens in trees. If we can mimic this process and develop heat removal devices, then we can develop efficient cooling devices. The existing passive flow based cooling devices still needs improvement to meet the future demands. To improve the efficiency and capacity of these devices, we need to explore and quantify the passive flow happening at nanoscales. Experimental techniques have not advanced enough to study these fundamental phenomena at the nanoscale, an alternative method is to perform theoretical study at nanoscales. Molecular dynamics (MD) simulation is a widely accepted powerful tool for studying a range of fundamental and engineering problems. MD simulations can be utilized to study the passive flow mechanism and heat transfer due to it. To study passive flow using MD, apart from the conventional methods available in MD, we need to have methods to simulate the heat transfer between solid and liquid, local pressure, surface tension, density, temperature calculation methods, realistic boundary conditions, etc. Heat transfer between solid and fluids has been a challenging area in MD simulations, and has only been minimally explored (especially for a practical fluid like water). Conventionally, an

  12. Rational defect passivation of Cu2ZnSn(S,Se)4 photovoltaics with solution-processed Cu2ZnSnS4:Na nanocrystals.

    PubMed

    Zhou, Huanping; Song, Tze-Bin; Hsu, Wan-Ching; Luo, Song; Ye, Shenglin; Duan, Hsin-Sheng; Hsu, Chia-Jung; Yang, Wenbing; Yang, Yang

    2013-10-30

    An effective defect passivation route has been demonstrated in the rapidly growing Cu2ZnSn(S,Se)4 (CZTSSe) solar cell device system by using Cu2ZnSnS4:Na (CZTS:Na) nanocrystals precursors. CZTS:Na nanocrystals are obtained by sequentially preparing CZTS nanocrystals and surface decorating of Na species, while retaining the kesterite CZTS phase. The exclusive surface presence of amorphous Na species is proved by X-ray photoluminescence spectrum and transmission electron microscopy. With Na-free glasses as the substrate, CZTS:Na nanocrystal-based solar cell device shows 50% enhancement of device performance (∼6%) than that of unpassivated CZTS nanocrystal-based device (∼4%). The enhanced electrical performance is closely related to the increased carrier concentration and elongated minority carrier lifetime, induced by defect passivation. Solution incorporation of extrinsic additives into the nanocrystals and the corresponding film enables a facile, quantitative, and versatile approach to tune the defect property of materials for future optoelectronic applications.

  13. Benthic processes and coastal aquaculture: merging models and field data at a local scale

    NASA Astrophysics Data System (ADS)

    Brigolin, Daniele; Rabouille, Christophe; Bombled, Bruno; Colla, Silvia; Pastres, Roberto; Pranovi, Fabio

    2016-04-01

    Shellfish farming is regarded as an organic extractive aquaculture activity. However, the production of faeces and pseudofaeces, in fact, leads to a net transfer of organic matter from the water column to the surface sediment. This process, which is expected to locally affect the sediment biogeochemistry, may also cause relevant changes in coastal areas characterized by a high density of farms. In this paper, we present the result of a study recently carried out in the Gulf of Venice (northern Adriatic sea), combining mathematical modelling and field sampling efforts. The work aimed at using a longline mussel farm as an in-situ test-case for modelling the differences in soft sediments biogeochemical processes along a gradient of organic deposition. We used an existing integrated model, allowing to describe biogeochemical fluxes towards the mussel farm and to predict the extent of the deposition area underneath it. The model framework includes an individual-based population dynamic model of the Mediterranean mussel coupled with a Lagrangian deposition model and a 1D benthic model of early diagenesis. The work was articulated in 3 steps: 1) the integrated model allowed to simulate the downward fluxes of organic matter originated by the farm, and the extent of its deposition area; 2) based on the first model application, two stations were localized, at which sediment cores were collected during a field campaign, carried out in June 2015. Measurements included O2 and pH microprofiling, porosity and micro-porosity, Total Organic Carbon, and pore waters NH4, PO4, SO4, Alkalinity, and Dissolved Inorganic Carbon; 3) two distinct early diagenesis models were set-up, reproducing observed field data in the sampled cores. Observed oxygen microprofiles showed a different behavior underneath the farm with respect to the outside reference station. In particular, a remarkable decrease in the oxygen penetration depth, and an increase in the O2 influx calculated from the

  14. Hood River Passive House

    SciTech Connect

    Hales, D.

    2013-03-01

    The Hood River Passive Project was developed by Root Design Build of Hood River Oregon using the Passive House Planning Package (PHPP) to meet all of the requirements for certification under the European Passive House standards. The Passive House design approach has been gaining momentum among residential designers for custom homes and BEopt modeling indicates that these designs may actually exceed the goal of the U.S. Department of Energy's (DOE) Building America program to reduce home energy use by 30%-50% (compared to 2009 energy codes for new homes). This report documents the short term test results of the Shift House and compares the results of PHPP and BEopt modeling of the project.

  15. Techniques for active passivation

    SciTech Connect

    Roscioli, Joseph R.; Herndon, Scott C.; Nelson, Jr., David D.

    2016-12-20

    In one embodiment, active (continuous or intermittent) passivation may be employed to prevent interaction of sticky molecules with interfaces inside of an instrument (e.g., an infrared absorption spectrometer) and thereby improve response time. A passivation species may be continuously or intermittently applied to an inlet of the instrument while a sample gas stream is being applied. The passivation species may have a highly polar functional group that strongly binds to either water or polar groups of the interfaces, and once bound presents a non-polar group to the gas phase in order to prevent further binding of polar molecules. The instrument may be actively used to detect the sticky molecules while the passivation species is being applied.

  16. Excitatory Local Circuits and Their Implications for Olfactory Processing in the Fly Antennal Lobe

    PubMed Central

    Shang, Yuhua; Claridge-Chang, Adam; Sjulson, Lucas; Pypaert, Marc; Miesenböck, Gero

    2007-01-01

    Summary Conflicting views exist of how circuits of the antennal lobe, the insect equivalent of the olfactory bulb, translate input from olfactory receptor neurons (ORNs) into projection neuron (PN) output. Synaptic connections between ORNs and PNs are one-to-one, yet PNs are more broadly tuned to odors than ORNs. The basis for this difference in receptive range remains unknown. Analyzing a Drosophila mutant lacking ORN input to one glomerulus, we show that some of the apparent complexity in the antennal lobe’s output arises from lateral, interglomerular excitation of PNs. We describe a previously unidentified population of cholinergic local neurons (LNs) with multiglomerular processes. These excitatory LNs respond broadly to odors but exhibit little glomerular specificity in their synaptic output, suggesting that PNs are driven by a combination of glomerulus-specific ORN afferents and diffuse LN excitation. Lateral excitation may boost PN signals and enhance their transmission to third-order neurons in a mechanism akin to stochastic resonance. PMID:17289577

  17. Fungal isolates and metabolites in locally processed rice from five agro-ecological zones of Nigeria.

    PubMed

    Abdus-Salaam, Rofiat; Atanda, Olusegun; Fanelli, Francesca; Sulyok, Micheal; Cozzi, Giuseppe; Bavaro, Simona; Krska, Rudolf; Logrieco, Antonio F; Ezekiel, Chibundu N; Salami, Waheed A

    2016-12-01

    This study reports the distribution of fungal isolates and fungal metabolites that naturally contaminate locally processed rice from five agro-ecological zones of Nigeria. The fungal species were isolated by the dilution plate technique and identified by appropriate diagnostics, while metabolites were determined by a liquid chromatographic tandem mass spectrometric method. Aspergillus and Penicillium species were the predominant isolates found in the rice samples while Fusarium spp. were not isolated. The mean fungal count differed significantly (p < 0.05) across the zones and ranged from 9.98 × 10(2) cfu g(-1) in the Southern Guinea Savannah to 96.97 × 10(2) cfu g(-1) in the Derived Savannah. For 16 fungal metabolites, selected from 63 positively identified fungal metabolites based on their concentration and spread across the zones, an occurrence map was constructed. The Northern Guinea Savannah recorded the highest contamination of fungal metabolites while the Sudan Savannah zone recorded the least.

  18. Local Scale Radiobrightness Modelling during Intensive Observing Period-4 of the Cold Land Processes Experiment-1

    NASA Technical Reports Server (NTRS)

    Kim, Edward J.; Tedesco, Marco; deRoo, Roger; England, Anthony W.; Gu, Haoyu; Pham, Hanh; Boprie, David; Graf, Tobias; Koike, Toshio; Armstrong, Richard

    2004-01-01

    The NASA Cold Land Processes Field Experiment (CLPX-1) was designed to provide microwave remote sensing observations and ground truth for studies of snow and frozen ground remote sensing, particularly issues related to scaling. CLPX-1 was conducted in the spring of 2003 in Colorado, USA. Initial forward model validation work is concentrating on the Local-Scale Observation Site (LSOS), a 0.8 ha study site consisting of open meadows separated by trees where the most detailed measurements were made of snow depth and temperature, density, and grain size profiles. This paper will focus on the ability of forward Dense Medium Radiative Transfer (DMRT) modelling, combined with snowpack measurements to reproduce the radiobrightness signatures observed by the University of Michigan s Truck-Mounted Radiometer System at 19 and 37 GHz during the 4th Intensive Observing Period (IOP4) in March, 2003. Unlike the earlier IOP3, conditions during IOP4 include both wet and dry periods, providing a valuable test of DMRT model performance. Observations of upwelling and downwelling tree radiobrightness will be used to formulate a simple model for the effect of trees within the field of view. In addition, a comparison will be made for the one day of coincident observations by the University of Tokyo s Ground- Based Microwave Radiometer-7 (GBMR-7). These analyses will help guide the choice of future snow retrieval algorithms and the design of future Cold Lands observing systems.

  19. Packaged water: optimizing local processes for sustainable water delivery in developing nations.

    PubMed

    Dada, Ayokunle C

    2011-07-29

    With so much global attention and commitment towards making the Water and Sanitation targets of the Millennium Development Goals (MDGs) a reality, available figures seem to speak on the contrary as they reveal a large disparity between the expected and what currently obtains especially in developing countries. As studies have shown that the standard industrialized world model for delivery of safe drinking water technology may not be affordable in much of the developing world, packaged water is suggested as a low cost, readily available alternative water provision that could help bridge the gap. Despite the established roles that this drinking water source plays in developing nations, its importance is however significantly underestimated, and the source considered unimproved going by 'international standards'. Rather than simply disqualifying water from this source, focus should be on identifying means of improvement. The need for intervening global communities and developmental organizations to learn from and build on the local processes that already operate in the developing world is also emphasized. Identifying packaged water case studies of some developing nations, the implication of a tenacious focus on imported policies, standards and regulatory approaches on drinking water access for residents of the developing world is also discussed.

  20. Local recharge processes in glacial and alluvial deposits of a temperate catchment

    NASA Astrophysics Data System (ADS)

    Fragalà, Federico A.; Parkin, Geoff

    2010-07-01

    SummaryThis study demonstrates that the composition and structure of Quaternary deposits and topography significantly influence rates of recharge and distribution of diffuse agricultural pollution at the hillslope scale. Analyses were made of vertical profiles of naturally-occurring chloride and nitrate, and artificially introduced bromide, in unsaturated and saturated sections of borehole cores of glacial till and alluvium under different land uses in the Upper Eden valley (UK). Estimates of local potential recharge were made based on chloride mass balance and nitrate peak methods. Persistent chloride bulges below the root zone were observed, and are interpreted to result from filtration processes at lithological boundaries. Changes in the shape of chloride profiles downslope, corroborated by nitrate profiles, indicate the roles of surface or near-surface runoff and runon, and the existence of lateral subsurface flows at depth. These findings have implications for estimation of recharge rates through unsaturated zones in Quaternary deposits, and the interpretation of potential 'hot-spots' of diffuse agrochemicals, particularly nitrates, moving through Quaternary deposits into groundwater.

  1. Power spectra in totally asymmetric simple exclusion process (TASEP) with local inhomogeneity

    NASA Astrophysics Data System (ADS)

    Dong, Jiajia; Zia, Royce K. P.

    2010-03-01

    As a paradigmatic system in non-equilibrium statistical mechanics, TASEP has been extensively studied in the abstract and also applied to model many complex phenomena such as traffic flow and protein synthesis. We focus on a rather less studied aspect of TASEP: the total number of particles on a one-dimension open TASEP at time t, N(t), and its power spectra I(φ), especially when there are local inhomogeneities. Motivated by the protein synthesis process where messenger RNA, codons and ribosomes are associated with the underlying lattice, sites and particles transported in TASEP, we investigate the effect on the power spectrum due to one defect (slower hopping rate) at different positions along the lattice. Using Monte Carlo simulation, we measure I(φ) for both the entire system and the subsystems separated by the defect. As in previous studies, oscillations are found. Here, however, more interesting characteristics emerge, depending on the location and the ``strength'' of the slow site. The biological implication of these results is also discussed.

  2. Evaluation of Alternate Stainless Steel Surface Passivation Methods

    SciTech Connect

    Clark, Elliot A.

    2005-05-31

    Stainless steel containers were assembled from parts passivated by four commercial vendors using three passivation methods. The performance of these containers in storing hydrogen isotope mixtures was evaluated by monitoring the composition of initially 50% H{sub 2} 50% D{sub 2} gas with time using mass spectroscopy. Commercial passivation by electropolishing appears to result in surfaces that do not catalyze hydrogen isotope exchange. This method of surface passivation shows promise for tritium service, and should be studied further and considered for use. On the other hand, nitric acid passivation and citric acid passivation may not result in surfaces that do not catalyze the isotope exchange reaction H{sub 2} + D{sub 2} {yields} 2HD. These methods should not be considered to replace the proprietary passivation processes of the two current vendors used at the Savannah River Site Tritium Facility.

  3. The role of local versus biogeographical processes in influencing diversity and body-size variation in mammal assemblages.

    PubMed

    Lopez, Luiz Carlos S; Figueiredo, Marcos S L; Fracasso, Maria Paula de Aguiar; Mesquita, Daniel Oliveira; Anjos, Ulisses Umbelino; Grelle, Carlos Eduardo Viveiros

    2016-03-01

    Our objective was to estimate and analyze the body-size distribution parameters of terrestrial mammal assemblages at different spatial scales, and to determine whether these parameters are controlled by local ecological processes or by larger-scale ones. Based on 93 local assemblages, plus the complete mammal assemblage from three continents (Africa, North, and South America), we estimated three key distribution parameters (diversity/size slope, skewness, and modal size) and compared the values to those expected if size distributions are mainly controlled by local interactions. Mammal diversity decreased much faster as body size increased than predicted by fractal niche theory, both at continental and at local scales, with continental distributions showing steeper slopes than the localities within them. South America showed a steeper slope (after controlling for species diversity), compared to Africa and North America, at local and continental scales. We also found that skewness and modal body size can show strikingly different correlations with predictor variables, such as species richness and median size, depending on the use of untransformed versus log-transformed data, due to changes in the distribution density generated by log-transformation. The main differences in slope, skewness, and modal size between local and continental scales appear to arise from the same biogeographical process, where small-sized species increase in diversity much faster (due to higher spatial turnover rates) than large-sized species. This process, which can operate even in the absence of competitive saturation at local scales, generates continental assemblages with steeper slopes, smaller modal sizes, and higher right skewness (toward small-sized species) compared to local communities. In addition, historical factors can also affect the size distribution slopes, which are significantly steeper, in South American mammal assemblages (probably due to stronger megafauna extinction events

  4. Monitoring Coastal Processes at Local and Regional Geographic Scales with UAS

    NASA Astrophysics Data System (ADS)

    Starek, M. J.; Bridges, D.; Prouty, D.; Berryhill, J.; Williams, D.; Jeffress, G.

    2014-12-01

    Unmanned Aerial Systems (UAS) provide a powerful tool for coastal mapping due to attractive features such as low cost data acquisition, flexibility in data capture and resolution, rapid response, and autonomous flight. We investigate two different scales of UAS platforms for monitoring coastal processes along the central Texas Gulf coast. Firstly, the eBee is a small-scale UAS weighing ~0.7 kg designed for localized mapping. The imaging payload consists of a hand held RGB digital camera and NIR digital camera, both with 16.1 megapixel resolutions. The system can map up to 10 square kilometers on a single flight and is capable of acquiring imagery down to 1.5 cm ground sample distance. The eBee is configured with a GPS receiver, altitude sensor, gyroscope and a radio transmitter enabling autonomous flight. The system has a certificate of authorization (COA) from the FAA to fly over the Ward Island campus of Texas A&M University-Corpus Christi (TAMUCC). The campus has an engineered beach, called University Beach, located along Corpus Christi Bay. A set of groins and detached breakwaters were built in an effort to protect the beach from erosive wave action. The eBee is being applied to periodically survey the beach (Figure 1A). Through Structure from Motion (SfM) techniques, eBee-derived image sequences are post-processed to extract 3D topography and measure volumetric change. Additionally, when water clarity suffices, this approach enables the extraction of shallow-water bathymetry. Results on the utilization of the eBee to monitor beach morphodynamics will be presented including a comparison of derived estimates to RTK GPS and airborne lidar. Secondly, the RS-16 UAS has a 4 m wingspan and 11 kg sensor payload. The system is remotely piloted and has a flight endurance of 12 to 16 hours making it suitable for regional scale coastal mapping. The imaging payload consists of a multispectral sensor suite measuring in the visible, thermal IR, and ultraviolet ranges of the

  5. Electrical stability enhancement of GeInGaO thin-film transistors by solution-processed Li-doped yttrium oxide passivation

    NASA Astrophysics Data System (ADS)

    Choi, U. H.; Yoon, S.; Yoon, D. H.; Tak, Y. J.; Kim, Y.-G.; Ahn, B. D.; Park, J.; Kim, H. J.

    2016-07-01

    In this study, we investigated a method of enhancing the electrical stability of GeInGaO thin-film transistors (TFTs) using a Li-doped Y2O3 (YO) passivation layer (PVL). Li reduced metal hydroxide groups in the PVL, and diffused into the channel layer and reduced the oxygen vacancy at the top surface of the channel layer, which is the origin of the defect state and electrical instability. In addition, the negative-bias temperature stress (NBTS) for 3600 s improved for Li-doped YO (LYO) PVL. The threshold voltage shift decreased from  -10.3 V for the YO PVL to  -4.8 V for the LYO PVL, a 54% improvement.

  6. Superacid Passivation of Crystalline Silicon Surfaces.

    PubMed

    Bullock, James; Kiriya, Daisuke; Grant, Nicholas; Azcatl, Angelica; Hettick, Mark; Kho, Teng; Phang, Pheng; Sio, Hang C; Yan, Di; Macdonald, Daniel; Quevedo-Lopez, Manuel A; Wallace, Robert M; Cuevas, Andres; Javey, Ali

    2016-09-14

    The reduction of parasitic recombination processes commonly occurring within the silicon crystal and at its surfaces is of primary importance in crystalline silicon devices, particularly in photovoltaics. Here we explore a simple, room temperature treatment, involving a nonaqueous solution of the superacid bis(trifluoromethane)sulfonimide, to temporarily deactivate recombination centers at the surface. We show that this treatment leads to a significant enhancement in optoelectronic properties of the silicon wafer, attaining a level of surface passivation in line with state-of-the-art dielectric passivation films. Finally, we demonstrate its advantage as a bulk lifetime and process cleanliness monitor, establishing its compatibility with large area photoluminescence imaging in the process.

  7. Exposure of lima bean leaves to volatiles from herbivore-induced conspecific plants results in emission of carnivore attractants: active or passive process?

    PubMed

    Choh, Yasuyuki; Shimoda, Takeshi; Ozawa, Rika; Dicke, Marcel; Takabayashi, Junji

    2004-07-01

    There is increasing evidence that volatiles emitted by herbivore-damaged plants can cause responses in downwind undamaged neighboring plants, such as the attraction of carnivorous enemies of herbivores. One of the open questions is whether this involves an active (production of volatiles) or passive (adsorption of volatiles) response of the uninfested downwind plant. This issue is addressed in the present study. Uninfested lima bean leaves that were exposed to volatiles from conspecific leaves infested with the spider mite Tetranychus urticae, emitted very similar blends of volatiles to those emitted from infested leaves themselves. Treating leaves with a protein-synthesis inhibitor prior to infesting them with spider mites completely suppressed the production of herbivore-induced volatiles in the infested leaves. Conversely, inhibitor treatment to uninfested leaves prior to exposure to volatiles from infested leaves did not affect the emission of volatiles from the exposed, uninfested leaves. This evidence supports the hypothesis that response of the exposed downwind plant is passive. T. urticae-infested leaves that had been previously exposed to volatiles from infested leaves emitted more herbivore-induced volatiles than T. urticae-infested leaves previously exposed to volatiles from uninfested leaves. The former leaves were also more attractive to the predatory mite, Phytoseiulus persimilis, than the latter. This shows that previous exposure of plants to volatiles from herbivore-infested neighbors results in a stronger response of plants in terms of predator attraction when herbivores damage the plant. This supports the hypothesis that the downwind uninfested plant is actively involved. Both adsorption and production of volatiles can mediate the attraction of carnivorous mites to plants that have been exposed to volatiles from infested neighbors.

  8. Local Authority Approaches to the School Admissions Process. LG Group Research Report

    ERIC Educational Resources Information Center

    Rudd, Peter; Gardiner, Clare; Marson-Smith, Helen

    2010-01-01

    What are the challenges, barriers and facilitating factors connected to the various school admissions approaches used by local authorities? This report gathers the views of local authority admissions officers on the strengths and weaknesses of different approaches, as well as the issues and challenges they face in this important area. It covers:…

  9. Trait inferences in goal-directed behavior: ERP timing and localization under spontaneous and intentional processing

    PubMed Central

    Van den Eede, Sofie; Baetens, Kris; Vandekerckhove, Marie

    2009-01-01

    This study measured event-related potentials (ERPs) during multiple goal and trait inferences, under spontaneous or intentional instructions. Participants read sentences describing several goal-implying behaviors of a target person from which also a strong trait could be inferred or not. The last word of each sentence determined the consistency with the inference induced during preceding sentences. In comparison with behaviors that implied only a goal, stronger waveforms beginning at ∼150 ms were obtained when the behaviors additionally implied a trait. These ERPs showed considerable parallels between spontaneous and intentional inferences. This suggests that traits embedded in a stream of goal-directed behaviors were detected more rapidly and automatically than mere goals, irrespective of the participants’ spontaneous or intentional instructions. In line with this, source localization (LORETA) of the ERPs show predominantly activation in the temporo-parietal junction (TPJ) during 150–200 ms, suggesting that goals were detected at that time interval. During 200–300 ms, activation was stronger at the medial prefrontal cortex (mPFC) for multiple goals and traits as opposed to goals only, suggesting that traits were inferred during this time window. A cued recall measure taken after the presentation of the stimulus material support the occurrence of goal and trait inferences and shows significant correlations with the neural components, indicating that these components are valid neural indices of spontaneous and intentional social inferences. The early detection of multiple goal and trait inferences is explained in terms of their greater social relevance, leading to privileged attention allocation and processing in the brain. PMID:19270041

  10. Extensometric observation of Earth tides and local tectonic processes at the Vyhne station, Slovakia

    NASA Astrophysics Data System (ADS)

    Brimich, Ladislav; Bednárik, Martin; Bezák, Vladimír; Kohút, Igor; Bán, Dóra; Eper-Pápai, Ildikó; Mentes, Gyula

    2016-06-01

    The Vyhne Tidal Station of the Earth Science Institute of the Slovak Academy of Sciences is located in the former mining gallery of St. Anthony of Padua in the Vyhne valley, Štiavnické vrchy Mts., Central Slovakia. It is equipped with a 20.5 metre long quartz-tube extensometer measuring Earth's tides, and long-term tectonic deformations of the Earth's crust. Data between 2001 and 2015 with some diverse gaps were digitally collected, processed and analysed. The effects of the local conditions, such as structure of the observatory, cavity effect, topography and geological features of the surrounding rocks, were investigated in detail and these effects were taken into consideration during the interpretation of the results of the data analysis. Tidal analysis of the extensometric data between 2005 and 2015 revealed that the measured tidal amplitudes are close to the theoretical values. The tidal transfer of the observatory was also investigated by coherence analysis between the theoretical and the measured extensometric data. The coherence is better than 0.9 both in the diurnal and semidiurnal band. The effect of the free core nutation resonance was also investigated in the case of the K1 and P1 tidal components. Since the K1/O1 ratio was about the theoretical value 0.8, than the P1/O1 was between 1.0 and 1.15 instead of the theoretical value of 0.9. The rate of the long-term strain rate was also investigated and the obtained -0.05 μstr/y shows a good agreement with the strain rate inferred from GPS measurements in the Central European GPS Reference Network.

  11. Trait inferences in goal-directed behavior: ERP timing and localization under spontaneous and intentional processing.

    PubMed

    Van Overwalle, Frank; Van den Eede, Sofie; Baetens, Kris; Vandekerckhove, Marie

    2009-06-01

    This study measured event-related potentials (ERPs) during multiple goal and trait inferences, under spontaneous or intentional instructions. Participants read sentences describing several goal-implying behaviors of a target person from which also a strong trait could be inferred or not. The last word of each sentence determined the consistency with the inference induced during preceding sentences. In comparison with behaviors that implied only a goal, stronger waveforms beginning at approximately 150 ms were obtained when the behaviors additionally implied a trait. These ERPs showed considerable parallels between spontaneous and intentional inferences. This suggests that traits embedded in a stream of goal-directed behaviors were detected more rapidly and automatically than mere goals, irrespective of the participants' spontaneous or intentional instructions. In line with this, source localization (LORETA) of the ERPs show predominantly activation in the temporo-parietal junction (TPJ) during 150-200 ms, suggesting that goals were detected at that time interval. During 200-300 ms, activation was stronger at the medial prefrontal cortex (mPFC) for multiple goals and traits as opposed to goals only, suggesting that traits were inferred during this time window. A cued recall measure taken after the presentation of the stimulus material support the occurrence of goal and trait inferences and shows significant correlations with the neural components, indicating that these components are valid neural indices of spontaneous and intentional social inferences. The early detection of multiple goal and trait inferences is explained in terms of their greater social relevance, leading to privileged attention allocation and processing in the brain.

  12. Localized traveling ionization zones and their importance for the high power impulse magnetron sputtering process

    NASA Astrophysics Data System (ADS)

    Maszl, Christian

    2016-09-01

    High power impulse magnetron sputtering (HiPIMS) is a technique to deposit thin films with superior quality. A high ionization degree up to 90% and the natural occurence of high energetic metal ions are the reason why HiPIMS exceeds direct current magnetron sputtering in terms of coating quality. On the other hand HiPIMS suffers from a reduced efficiency, especially if metal films are produced. Therefore, a lot of research is done by experimentalists and theoreticians to clarify the transport mechanisms from target to substrate and to identify the energy source of the energetic metal ions. Magnetron plasmas are prone to a wide range of wave phenomena and instabilities. Especially, during HiPIMS at elevated power/current densities, symmetry breaks and self-organization in the plasma torus are observed. In this scenario localized travelling ionization zones with certain quasi-mode numbers are present which are commonly referred to as spokes. Because of their high rotation speed compared to typical process times of minutes their importance for thin film deposition was underestimated at first. Recent investigations show that spokes have a strong impact on particle transport, are probably the source of the high energetic metal ions and are therefore the essence of HiPIMS plasmas. In this contribution we will describe the current understanding of spokes, discuss implications for thin film synthesis and highlight open questions. This project is supported by the DFG (German Science Foundation) within the framework of the Coordinated Research Center SFB-TR 87 and the Research Department ``Plasmas with Complex Interactions'' at Ruhr-University Bochum.

  13. Spared and impaired spoken discourse processing in schizophrenia: effects of local and global language context.

    PubMed

    Swaab, Tamara Y; Boudewyn, Megan A; Long, Debra L; Luck, Steve J; Kring, Ann M; Ragland, J Daniel; Ranganath, Charan; Lesh, Tyler; Niendam, Tara; Solomon, Marjorie; Mangun, George R; Carter, Cameron S

    2013-09-25

    Individuals with schizophrenia are impaired in a broad range of cognitive functions, including impairments in the controlled maintenance of context-relevant information. In this study, we used ERPs in human subjects to examine whether impairments in the controlled maintenance of spoken discourse context in schizophrenia lead to overreliance on local associations among the meanings of individual words. Healthy controls (n = 22) and patients (n = 22) listened to short stories in which we manipulated global discourse congruence and local priming. The target word in the last sentence of each story was globally congruent or incongruent and locally associated or unassociated. ERP local association effects did not significantly differ between control participants and schizophrenia patients. However, in contrast to controls, patients only showed effects of discourse congruence when targets were primed by a word in the local context. When patients had to use discourse context in the absence of local priming, they showed impaired brain responses to the target. Our findings indicate that schizophrenia patients are impaired during discourse comprehension when demands on controlled maintenance of context are high. We further found that ERP measures of increased reliance on local priming predicted reduced social functioning, suggesting that alterations in the neural mechanisms underlying discourse comprehension have functional consequences in the illness.

  14. Microgravity Passive Phase Separator

    NASA Technical Reports Server (NTRS)

    Paragano, Matthew; Indoe, William; Darmetko, Jeffrey

    2012-01-01

    A new invention disclosure discusses a structure and process for separating gas from liquids in microgravity. The Microgravity Passive Phase Separator consists of two concentric, pleated, woven stainless- steel screens (25-micrometer nominal pore) with an axial inlet, and an annular outlet between both screens (see figure). Water enters at one end of the center screen at high velocity, eventually passing through the inner screen and out through the annular exit. As gas is introduced into the flow stream, the drag force exerted on the bubble pushes it downstream until flow stagnation or until it reaches an equilibrium point between the surface tension holding bubble to the screen and the drag force. Gas bubbles of a given size will form a front that is moved further down the length of the inner screen with increasing velocity. As more bubbles are added, the front location will remain fixed, but additional bubbles will move to the end of the unit, eventually coming to rest in the large cavity between the unit housing and the outer screen (storage area). Owing to the small size of the pores and the hydrophilic nature of the screen material, gas does not pass through the screen and is retained within the unit for emptying during ground processing. If debris is picked up on the screen, the area closest to the inlet will become clogged, so high-velocity flow will persist farther down the length of the center screen, pushing the bubble front further from the inlet of the inner screen. It is desired to keep the velocity high enough so that, for any bubble size, an area of clean screen exists between the bubbles and the debris. The primary benefits of this innovation are the lack of any need for additional power, strip gas, or location for venting the separated gas. As the unit contains no membrane, the transport fluid will not be lost due to evaporation in the process of gas separation. Separation is performed with relatively low pressure drop based on the large surface

  15. A comparison between EEG source localization and fMRI during the processing of emotional visual stimuli

    NASA Astrophysics Data System (ADS)

    Hu, Jin; Tian, Jie; Pan, Xiaohong; Liu, Jiangang

    2007-03-01

    The purpose of this paper is to compare between EEG source localization and fMRI during emotional processing. 108 pictures for EEG (categorized as positive, negative and neutral) and 72 pictures for fMRI were presented to 24 healthy, right-handed subjects. The fMRI data were analyzed using statistical parametric mapping with SPM2. LORETA was applied to grand averaged ERP data to localize intracranial sources. Statistical analysis was implemented to compare spatiotemporal activation of fMRI and EEG. The fMRI results are in accordance with EEG source localization to some extent, while part of mismatch in localization between the two methods was also observed. In the future we should apply the method for simultaneous recording of EEG and fMRI to our study.

  16. Wireless passive radiation sensor

    DOEpatents

    Pfeifer, Kent B; Rumpf, Arthur N; Yelton, William G; Limmer, Steven J

    2013-12-03

    A novel measurement technique is employed using surface acoustic wave (SAW) devices, passive RF, and radiation-sensitive films to provide a wireless passive radiation sensor that requires no batteries, outside wiring, or regular maintenance. The sensor is small (<1 cm.sup.2), physically robust, and will operate unattended for decades. In addition, the sensor can be insensitive to measurement position and read distance due to a novel self-referencing technique eliminating the need to measure absolute responses that are dependent on RF transmitter location and power.

  17. Atomic Scale Understanding of Poly-Si/SiO2/c-Si Passivated Contacts: Passivation Degradation Due to Metallization

    SciTech Connect

    Aguiar, Jeffery A.; Young, David; Lee, Benjamin; Nemeth, William; Harvey, Steve; Aoki, Toshihiro; Al-Jassim, Mowafak; Stradins, Paul

    2016-11-21

    The key attributes for achieving high efficiency crystalline silicon solar cells include class leading developments in the ability to approach the theoretical limits of silicon solar technology (29.4% efficiency). The push for high efficiency devices is further compounded with the clear need for passivation to reduce recombination at the metal contacts. At the same time there is stringent requirement to retain the same material device quality, surface passivation, and performance characteristics following subsequent processing. The development of passivated silicon cell structures that retain active front and rear surface passivation and overall material cell quality is therefore a relevant and active area of development. To address the potential outcomes of metallization on passivated silicon stack, we report on some common microstructural features of degradation due to metallization for a series of silicon device stacks. A fundamental materials understanding of the metallization process on retaining high-efficiency passivated Si devices is therefore gained over these series of results.

  18. A novel passivation process of silicon nanowires by a low-cost PECVD technique for deposition of hydrogenated silicon nitride using SiH4 and N2 as precursor gases

    NASA Astrophysics Data System (ADS)

    Bouaziz, Lamia; Dridi, Donia; Karyaoui, Mokhtar; Angelova, Todora; Sanchez Plaza, Guillermo; Chtourou, Radhouane

    2017-03-01

    In this work, a different SiNx passivation process of silicon nanowires has been opted for the deposition of a hydrogenated silicon nitride (SiNx:H) by a low-cost plasma enhanced chemical vapor deposition (PECVD) using silane ( SiH4 and nitrogen ( N2 as reactive gases. This study is focused on the effect of the gas flow ratio on chemical composition, morphological, optical and optoelectronic properties of silicon nanowires. The existence of Si-N and Si-H bonds was proven by the Fourier transmission infrared (FTIR) spectrum. Morphological structures were shown by scanning electron microscopy (SEM), and the roughness was investigated by atomic force microscopy (AFM). A low reflectivity less than 6% in the wavelength range 250-1200nm has been shown by UV-visible spectroscopy. Furthermore, the thickness and the refractive index of the passivation layer is determined by ellipsometry measurements. As a result, an improvement in minority carrier lifetime has been obtained by reducing surface recombination of silicon nanowires.

  19. Improvements to the design process for a real-time passive millimeter-wave imager to be used for base security and helicopter navigation in degraded visual environments

    NASA Astrophysics Data System (ADS)

    Anderton, Rupert N.; Cameron, Colin D.; Burnett, James G.; Güell, Jeff J.; Sanders-Reed, John N.

    2014-06-01

    This paper discusses the design of an improved passive millimeter wave imaging system intended to be used for base security in degraded visual environments. The discussion starts with the selection of the optimum frequency band. The trade-offs between requirements on detection, recognition and identification ranges and optical aperture are discussed with reference to the Johnson Criteria. It is shown that these requirements also affect image sampling, receiver numbers and noise temperature, frame rate, field of view, focusing requirements and mechanisms, and tolerance budgets. The effect of image quality degradation is evaluated and a single testable metric is derived that best describes the effects of degradation on meeting the requirements. The discussion is extended to tolerance budgeting constraints if significant degradation is to be avoided, including surface roughness, receiver position errors and scan conversion errors. Although the reflective twist-polarization imager design proposed is potentially relatively low cost and high performance, there is a significant problem with obscuration of the beam by the receiver array. Methods of modeling this accurately and thus designing for best performance are given.

  20. An all-silicon passive optical diode.

    PubMed

    Fan, Li; Wang, Jian; Varghese, Leo T; Shen, Hao; Niu, Ben; Xuan, Yi; Weiner, Andrew M; Qi, Minghao

    2012-01-27

    A passive optical diode effect would be useful for on-chip optical information processing but has been difficult to achieve. Using a method based on optical nonlinearity, we demonstrate a forward-backward transmission ratio of up to 28 decibels within telecommunication wavelengths. Our device, which uses two silicon rings 5 micrometers in radius, is passive yet maintains optical nonreciprocity for a broad range of input power levels, and it performs equally well even if the backward input power is higher than the forward input. The silicon optical diode is ultracompact and is compatible with current complementary metal-oxide semiconductor processing.

  1. Passive perception system for day/night autonomous off-road navigation

    NASA Astrophysics Data System (ADS)

    Rankin, Arturo L.; Bergh, Charles F.; Goldberg, Steven B.; Bellutta, Paolo; Huertas, Andres; Matthies, Larry H.

    2005-05-01

    Passive perception of terrain features is a vital requirement for military related unmanned autonomous vehicle operations, especially under electromagnetic signature management conditions. As a member of Team Raptor, the Jet Propulsion Laboratory developed a self-contained passive perception system under the DARPA funded PerceptOR program. An environmentally protected forward-looking sensor head was designed and fabricated in-house to straddle an off-the-shelf pan-tilt unit. The sensor head contained three color cameras for multi-baseline daytime stereo ranging, a pair of cooled mid-wave infrared cameras for nighttime stereo ranging, and supporting electronics to synchronize captured imagery. Narrow-baseline stereo provided improved range data density in cluttered terrain, while wide-baseline stereo provided more accurate ranging for operation at higher speeds in relatively open areas. The passive perception system processed stereo images and outputted over a local area network terrain maps containing elevation, terrain type, and detected hazards. A novel software architecture was designed and implemented to distribute the data processing on a 533MHz quad 7410 PowerPC single board computer under the VxWorks real-time operating system. This architecture, which is general enough to operate on N processors, has been subsequently tested on Pentium-based processors under Windows and Linux, and a Sparc based-processor under Unix. The passive perception system was operated during FY04 PerceptOR program evaluations at Fort A. P. Hill, Virginia, and Yuma Proving Ground, Arizona. This paper discusses the Team Raptor passive perception system hardware and software design, implementation, and performance, and describes a road map to faster and improved passive perception.

  2. The Part Played by Popular Education in Local Development Processes in Suburban and Rural Areas of Sweden

    ERIC Educational Resources Information Center

    Eriksson, Lisbeth; Forsberg, Anette

    2010-01-01

    On the basis of a three-year study of the role of popular education in local development processes in Sweden (2006-2008), this paper sets out to outline the role of popular education as a development actor in rural and urban contexts. Two different scenarios and approaches are discussed. One is the role of popular education in rural areas, which…

  3. The Broader Cognitive Phenotype of Autism in Parents: How Specific Is the Tendency for Local Processing and Executive Dysfunction?

    ERIC Educational Resources Information Center

    Bolte, Sven; Poustka, Fritz

    2006-01-01

    Background: The objective of this study was to investigate the tendency for local processing style ("weak central coherence") and executive dysfunction in parents of subjects with an autism spectrum disorder (ASD) compared with parents of individuals with early onset schizophrenia (EOS) and mental retardation (MR). Method: Sixty-two…

  4. Visual Local and Global Processing in Low-Functioning Deaf Individuals with and without Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Maljaars, J. P. W.; Noens, I. L. J.; Scholte, E. M.; Verpoorten, R. A. W.; van Berckelaer-Onnes, I. A.

    2011-01-01

    Background: The ComFor study has indicated that individuals with intellectual disability (ID) and autism spectrum disorder (ASD) show enhanced visual local processing compared with individuals with ID only. Items of the ComFor with meaningless materials provided the best discrimination between the two samples. These results can be explained by the…

  5. Processing of Basic Speech Acts Following Localized Brain Damage: A New Light on the Neuroanatomy of Language

    ERIC Educational Resources Information Center

    Soroker, N.; Kasher, A.; Giora, R.; Batori, G.; Corn, C.; Gil, M.; Zaidel, E.

    2005-01-01

    We examined the effect of localized brain lesions on processing of the basic speech acts (BSAs) of question, assertion, request, and command. Both left and right cerebral damage produced significant deficits relative to normal controls, and left brain damaged patients performed worse than patients with right-sided lesions. This finding argues…

  6. A Spatial Frequency Account of the Detriment that Local Processing of Navon Letters Has on Face Recognition

    ERIC Educational Resources Information Center

    Hills, Peter J.; Lewis, Michael B.

    2009-01-01

    Five minutes of processing the local features of a Navon letter causes a detriment in subsequent face-recognition performance (Macrae & Lewis, 2002). We hypothesize a perceptual after effect explanation of this effect in which face recognition is less accurate after adapting to high-spatial frequencies at high contrasts. Five experiments were…

  7. Method of passivating semiconductor surfaces

    DOEpatents

    Wanlass, M.W.

    1990-06-19

    A method is described for passivating Group III-V or II-VI semiconductor compound surfaces. The method includes selecting a passivating material having a lattice constant substantially mismatched to the lattice constant of the semiconductor compound. The passivating material is then grown as an ultrathin layer of passivating material on the surface of the Group III-V or II-VI semiconductor compound. The passivating material is grown to a thickness sufficient to maintain a coherent interface between the ultrathin passivating material and the semiconductor compound. In addition, a device formed from such method is also disclosed.

  8. Method of passivating semiconductor surfaces

    DOEpatents

    Wanlass, Mark W.

    1990-01-01

    A method of passivating Group III-V or II-VI semiconductor compound surfaces. The method includes selecting a passivating material having a lattice constant substantially mismatched to the lattice constant of the semiconductor compound. The passivating material is then grown as an ultrathin layer of passivating material on the surface of the Group III-V or II-VI semiconductor compound. The passivating material is grown to a thickness sufficient to maintain a coherent interface between the ultrathin passivating material and the semiconductor compound. In addition, a device formed from such method is also disclosed.

  9. Passive hydrogel fuel generator

    SciTech Connect

    Neefe, Ch. W.

    1985-04-16

    A passive hydrogen oxygen generator in which the long wavelength infrared portion of the sun's spectrum heats water to provide circulation of the water within the generator. The shorter wavelength portion of the spectrum to which water is transparent is used in splitting water into hydrogen and oxygen by photoelectrolysis.

  10. Hood River Passive House

    SciTech Connect

    Hales, David

    2014-01-01

    The Hood River Passive Project was developed by Root Design Build of Hood River Oregon using the Passive House Planning Package (PHPP) to meet all of the requirements for certification under the European Passive House standards. The Passive House design approach has been gaining momentum among residential designers for custom homes and BEopt modeling indicates that these designs may actually exceed the goal of the U.S. Department of Energy's (DOE) Building America program to "reduce home energy use by 30%-50% (compared to 2009 energy codes for new homes). This report documents the short term test results of the Shift House and compares the results of PHPP and BEopt modeling of the project. The design includes high R-Value assemblies, extremely tight construction, high performance doors and windows, solar thermal DHW, heat recovery ventilation, moveable external shutters and a high performance ductless mini-split heat pump. Cost analysis indicates that many of the measures implemented in this project did not meet the BA standard for cost neutrality. The ductless mini-split heat pump, lighting and advanced air leakage control were the most cost effective measures. The future challenge will be to value engineer the performance levels indicated here in modeling using production based practices at a significantly lower cost.

  11. Hood River Passive House

    SciTech Connect

    Hales, D.

    2014-01-01

    The Hood River Passive Project was developed by Root Design Build of Hood River Oregon using the Passive House Planning Package (PHPP) to meet all of the requirements for certification under the European Passive House standards. The Passive House design approach has been gaining momentum among residential designers for custom homes and BEopt modeling indicates that these designs may actually exceed the goal of the U.S. Department of Energy's (DOE) Building America program to reduce home energy use by 30%-50% (compared to 2009 energy codes for new homes). This report documents the short term test results of the Shift House and compares the results of PHPP and BEopt modeling of the project. The design includes high R-Value assemblies, extremely tight construction, high performance doors and windows, solar thermal DHW, heat recovery ventilation, moveable external shutters and a high performance ductless mini-split heat pump. Cost analysis indicates that many of the measures implemented in this project did not meet the BA standard for cost neutrality. The ductless mini-split heat pump, lighting and advanced air leakage control were the most cost effective measures. The future challenge will be to value engineer the performance levels indicated here in modeling using production based practices at a significantly lower cost.

  12. Passive MIMO Radar Detection

    DTIC Science & Technology

    2013-09-01

    Hypothesis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 3.3.3 Dependence on SNR...71 4.3.3 Dependence on SNR and DNR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 4.4 Interpretations...described as a passive radar network. The topology of such networks is described as bistatic, multistatic, or multiple-input multiple-output, depending on

  13. Spatial control of chemical processes on nanostructures through nano-localized water heating

    PubMed Central

    Jack, Calum; Karimullah, Affar S.; Tullius, Ryan; Khorashad, Larousse Khosravi; Rodier, Marion; Fitzpatrick, Brian; Barron, Laurence D.; Gadegaard, Nikolaj; Lapthorn, Adrian J.; Rotello, Vincent M.; Cooke, Graeme; Govorov, Alexander O.; Kadodwala, Malcolm

    2016-01-01

    Optimal performance of nanophotonic devices, including sensors and solar cells, requires maximizing the interaction between light and matter. This efficiency is optimized when active moieties are localized in areas where electromagnetic (EM) fields are confined. Confinement of matter in these ‘hotspots' has previously been accomplished through inefficient ‘top-down' methods. Here we report a rapid ‘bottom-up' approach to functionalize selective regions of plasmonic nanostructures that uses nano-localized heating of the surrounding water induced by pulsed laser irradiation. This localized heating is exploited in a chemical protection/deprotection strategy to allow selective regions of a nanostructure to be chemically modified. As an exemplar, we use the strategy to enhance the biosensing capabilities of a chiral plasmonic substrate. This novel spatially selective functionalization strategy provides new opportunities for efficient high-throughput control of chemistry on the nanoscale over macroscopic areas for device fabrication. PMID:26961708

  14. Spatial control of chemical processes on nanostructures through nano-localized water heating.

    PubMed

    Jack, Calum; Karimullah, Affar S; Tullius, Ryan; Khorashad, Larousse Khosravi; Rodier, Marion; Fitzpatrick, Brian; Barron, Laurence D; Gadegaard, Nikolaj; Lapthorn, Adrian J; Rotello, Vincent M; Cooke, Graeme; Govorov, Alexander O; Kadodwala, Malcolm

    2016-03-10

    Optimal performance of nanophotonic devices, including sensors and solar cells, requires maximizing the interaction between light and matter. This efficiency is optimized when active moieties are localized in areas where electromagnetic (EM) fields are confined. Confinement of matter in these 'hotspots' has previously been accomplished through inefficient 'top-down' methods. Here we report a rapid 'bottom-up' approach to functionalize selective regions of plasmonic nanostructures that uses nano-localized heating of the surrounding water induced by pulsed laser irradiation. This localized heating is exploited in a chemical protection/deprotection strategy to allow selective regions of a nanostructure to be chemically modified. As an exemplar, we use the strategy to enhance the biosensing capabilities of a chiral plasmonic substrate. This novel spatially selective functionalization strategy provides new opportunities for efficient high-throughput control of chemistry on the nanoscale over macroscopic areas for device fabrication.

  15. Spatial control of chemical processes on nanostructures through nano-localized water heating

    NASA Astrophysics Data System (ADS)

    Jack, Calum; Karimullah, Affar S.; Tullius, Ryan; Khorashad, Larousse Khosravi; Rodier, Marion; Fitzpatrick, Brian; Barron, Laurence D.; Gadegaard, Nikolaj; Lapthorn, Adrian J.; Rotello, Vincent M.; Cooke, Graeme; Govorov, Alexander O.; Kadodwala, Malcolm

    2016-03-01

    Optimal performance of nanophotonic devices, including sensors and solar cells, requires maximizing the interaction between light and matter. This efficiency is optimized when active moieties are localized in areas where electromagnetic (EM) fields are confined. Confinement of matter in these `hotspots' has previously been accomplished through inefficient `top-down' methods. Here we report a rapid `bottom-up' approach to functionalize selective regions of plasmonic nanostructures that uses nano-localized heating of the surrounding water induced by pulsed laser irradiation. This localized heating is exploited in a chemical protection/deprotection strategy to allow selective regions of a nanostructure to be chemically modified. As an exemplar, we use the strategy to enhance the biosensing capabilities of a chiral plasmonic substrate. This novel spatially selective functionalization strategy provides new opportunities for efficient high-throughput control of chemistry on the nanoscale over macroscopic areas for device fabrication.

  16. Comparison of local and regional heat transport processes into the subsurface urban heat island of Karlsruhe, Germany

    NASA Astrophysics Data System (ADS)

    Benz, Susanne; Bayer, Peter; Menberg, Kathrin; Blum, Philipp

    2014-05-01

    Temperatures in shallow urban ground are typically elevated. They manifest as subsurface urban heat islands, which are observed worldwide in different metropolitan areas and which have a site-specific areal extent and intensity. As of right now the governing heat transport processes accumulating heat in the subsurface of cities are insufficiently understood. Based on a spatial assessment of groundwater temperatures, six individual heat flux processes could be identified: (1) heat flux from elevated ground surface temperatures (GST), (2) heat flux from basements of buildings, (3) reinjection of thermal waste water, (4) sewage drains, (5) sewage leakage, and (6) district heating. In this study, the contributions of these processes are quantified on local and regional scales for the city of Karlsruhe in Germany. For the regional scale, the Regionalized Monte Carlo (RMC) method is used. This method applies a single Monte Carlo (MC) simulation for the entire study area. At relatively low data demand, the RMC method provides basic insights into the heat contribution for the entire city. For the local scale, the Local Monte Carlo (LMC) method was developed and applied. This method analyzes all dominant heat fluxes spatially dependent by performing an MC simulation for each arbitrary sized pixel of the study area (here 10 x 10 m). This more intricate approach allows for a spatial representation of all heat flux processes, which is necessary for the local planning of geothermal energy use. In order to evaluate the heat transport processes on a regional scale, we compared the mean annual thermal energies that result from the individual heat flux processes. Both methods identify the heat flux from elevated GST and the heat flux from buildings as the dominant regional processes. However, reinjection of thermal wastewater is by far the most dominant local heat flux processes with an average heat flux of 16 ± 2 W/m2 in the affected areas. Although being dominant on the regional

  17. Local fuzzy fractal dimension and its application in medical image processing.

    PubMed

    Zhuang, Xiaodong; Meng, Qingchun

    2004-09-01

    The local fuzzy fractal dimension (LFFD) is proposed to extract local fractal feature of medical images. The definition of LFFD is an extension of the pixel-covering method by incorporating the fuzzy set. Multi-feature edge detection is implemented with the LFFD and the Sobel operator. The LFFD can also serve as a characteristic of motion in medical image sequences. The experimental results show that the LFFD is an important feature of edge areas in medical images and can provide information for segmentation of echocardiogram image sequences.

  18. Ionic transport in passivation layered on the lithium electrode

    NASA Astrophysics Data System (ADS)

    Nimon, Eugeny S.; Churikov, Alexei V.; Shirokov, Alexander V.; Lvov, Arlen L.; Chuvashkin, Anatoly N.

    1993-04-01

    The processes of ionic transport in passivating layers on the surface of the lithium electrode in solutions based on thionyl chloride, propylene carbonate and gamma -butyrolactone have been studied by means of pulse electrochemical methods. The data obtained are quantitatively described by a model which takes into account transport of both the intrinsic mobile lithium ions of the passivating layer and lithium ions injected into the passivating layer from the electrode or from the electrolyte solution under anodic or cathodic current directions, respectively. The values of mobility and concentration of mobile lithium ions in passivating layers formed on lithium in various solutions under open-circuit conditions have been determined.

  19. Electrophysiological Indices of Spatial Attention during Global/Local Processing in Good and Poor Phonological Decoders

    ERIC Educational Resources Information Center

    Matthews, Allison Jane; Martin, Frances Heritage

    2009-01-01

    Previous research suggests a relationship between spatial attention and phonological decoding in developmental dyslexia. The aim of this study was to examine differences between good and poor phonological decoders in the allocation of spatial attention to global and local levels of hierarchical stimuli. A further aim was to investigate the…

  20. Educational Organization, School Localization and the Process of Urbanization in Sweden.

    ERIC Educational Resources Information Center

    Andrae, Annika

    Traditionally Sweden's educational system has been highly centralized; physical characteristics, administrative factors, and teacher qualifications have been generally standardized as have curriculums, though local implementation has been afforded considerable freedom. In 1971 the upper secondary school (9-12) consolidated three previously…

  1. Local and Global Processing in Blind and Sighted Children in a Naming and Drawing Task

    ERIC Educational Resources Information Center

    Puspitawati, Ira; Jebrane, Ahmed; Vinter, Annie

    2014-01-01

    This study investigated the spatial analysis of tactile hierarchical patterns in 110 early-blind children aged 6-8 to 16-18 years, as compared to 90 blindfolded sighted children, in a naming and haptic drawing task. The results revealed that regardless of visual status, young children predominantly produced local responses in both tasks, whereas…

  2. Processes governing phytoplankton blooms in estuaries. I: The local production-loss balance

    USGS Publications Warehouse

    Lucas, L.V.; Koseff, Jeffrey R.; Cloern, J.E.; Monismith, Stephen G.; Thompson, J.K.

    1999-01-01

    The formation and spatial distribution of phytoplankton blooms in estuaries are controlled by (1) local mechanisms, which determine the production-loss balance for a water column at a particular spatial location (i.e. control if a bloom is possible), and (2) transport-related mechanisms, which govern biomass distribution (i.e. control if and where a bloom actually occurs). In this study, the first of a 2-paper series, we use a depth-averaged numerical model as a theoretical tool to describe how interacting local conditions (water column height, light availability, benthic grazing) influence the local balance between phytoplankton sources and sinks. We also explore trends in the spatial variability of the production-loss balance across the topographic gradients between deep channels and lateral shoals which are characteristic of shallow estuaries. For example, under conditions of high turbidity and slow benthic grazing the highest rates of phytoplankton population growth are found in the shallowest regions. On the other hand, with low turbidity and rapid benthic grazing the highest growth rates occur in the deeper areas. We also explore the effects of semidiurnal tidal variation in water column height, as well as spring-neap variability. Local population growth in the shallowest regions is very sensitive to tidal-scale shallowing and deepening of the water column, especially in the presence of benthic grazing. A spring-neap signal in population growth rate is also prominent in the shallow areas. Population growth in deeper regions is less sensitive to temporal variations in tidal elevation. These results show that both shallow and deep regions of estuaries can act as sources or sinks for phytoplankton biomass, depending on the local conditions of mean water column height, tidal amplitude, light-limited growth rate, and consumption by grazers.

  3. Passive margins: A model of formation

    NASA Astrophysics Data System (ADS)

    Le Pichon, Xavier; Sibuet, Jean-Claude

    1981-05-01

    The stretching model of McKenzie is applied to the formation of passive continental margins, assuming local isostatic equilibrium. We present the quantitative implications of the model; we then discuss its fit to the IPOD data on the Armorican and Galicia continental margins of the northeast Atlantic. The amount of brittle stretching observed in the upper 8 km of the prestretched continental crust reaches a maximum value of about 3. This large amount of thinning is comparable to the thinning of the whole continental crust observed by seismic refraction measurements and required by the model for the whole lithosphere. This agreement suggests that the simple stretching model is a good first approximation to the actual physical process of formation of the margin. It is thus possible to compute simply the thermal evolution of the margin and to discuss its petrological consequences. It is also possible to obtain a quantitative reconstruction of the edge of the continent prior to breakup. Finally, the large slope of the base of the lithosphere during the formation of the margin results in a force similar but opposite to the `ridge-push' force acting on accreting plate boundaries.

  4. Passive Impact Damage Detection of Fiber Glass Composite Panels

    DTIC Science & Technology

    2013-12-19

    PASSIVE IMPACT DAMAGE DETECTION OF FIBER GLASS COMPOSITE PANELS. By BRUNO ZAMORANO-SENDEROS A dissertation...COVERED 04-11-2012 to 10-12-2013 4. TITLE AND SUBTITLE PASSIVE IMPACT DAMAGE DETECTION OF FIBER GLASS COMPOSITE PANELS 5a. CONTRACT NUMBER 5b...process. .................................... 31 Figure 3-8 Sensor attached to the fiber glass fabric

  5. Subjective visual perception: from local processing to emergent phenomena of brain activity.

    PubMed

    Panagiotaropoulos, Theofanis I; Kapoor, Vishal; Logothetis, Nikos K

    2014-05-05

    The combination of electrophysiological recordings with ambiguous visual stimulation made possible the detection of neurons that represent the content of subjective visual perception and perceptual suppression in multiple cortical and subcortical brain regions. These neuronal populations, commonly referred to as the neural correlates of consciousness, are more likely to be found in the temporal and prefrontal cortices as well as the pulvinar, indicating that the content of perceptual awareness is represented with higher fidelity in higher-order association areas of the cortical and thalamic hierarchy, reflecting the outcome of competitive interactions between conflicting sensory information resolved in earlier stages. However, despite the significant insights into conscious perception gained through monitoring the activities of single neurons and small, local populations, the immense functional complexity of the brain arising from correlations in the activity of its constituent parts suggests that local, microscopic activity could only partially reveal the mechanisms involved in perceptual awareness. Rather, the dynamics of functional connectivity patterns on a mesoscopic and macroscopic level could be critical for conscious perception. Understanding these emergent spatio-temporal patterns could be informative not only for the stability of subjective perception but also for spontaneous perceptual transitions suggested to depend either on the dynamics of antagonistic ensembles or on global intrinsic activity fluctuations that may act upon explicit neural representations of sensory stimuli and induce perceptual reorganization. Here, we review the most recent results from local activity recordings and discuss the potential role of effective, correlated interactions during perceptual awareness.

  6. Submerged passively-safe power plant

    SciTech Connect

    Herring, J.S.

    1991-12-31

    The invention as presented consists of a submerged passively-safe power station including a pressurized water reactor capable of generating at least 600 MW of electricity, encased in a double hull vessel, and provides fresh water by using the spent thermal energy in a multistage flash desalination process.

  7. Submerged passively-safe power plant

    DOEpatents

    Herring, J. Stephen

    1993-01-01

    The invention as presented consists of a submerged passively-safe power station including a pressurized water reactor capable of generating at least 600 MW of electricity, encased in a double hull vessel, and provides fresh water by using the spent thermal energy in a multistage flash desalination process.

  8. Submerged passively-safe power plant

    DOEpatents

    Herring, J.S.

    1993-09-21

    The invention as presented consists of a submerged passively-safe power station including a pressurized water reactor capable of generating at least 600 MW of electricity, encased in a double hull vessel, and provides fresh water by using the spent thermal energy in a multistage flash desalination process. 8 figures.

  9. A study of passive weight-bearing lower limb exercise effects on local muscles and whole body oxidative metabolism: a comparison with simulated horse riding, bicycle, and walking exercise

    PubMed Central

    2009-01-01

    Background We have developed an exercise machine prototype for increasing exercise intensity by means of passively exercising lower limb muscles. The purpose of the present study was to compare the passive exercise intensity of our newly-developed machine with the intensities of different types of exercises. We also attempted to measure muscle activity to study how these forms of exercise affected individual parts of the body. Methods Subjects were 14 healthy men with the following demographics: age 30 years, height 171.5 cm, weight 68.3 kg. They performed 4 types of exercise: Passive weight-bearing lower limb exercise (PWLLE), Simulated horse riding exercise (SHRE), Bicycle exercise, and Walking exercise, as described below at an interval of one week or longer. Oxygen uptake, blood pressure, heart rate, and electromyogram (EMG) were measured or recorded during exercise. At rest prior to exercise and immediately after the end of each exercise intensity, the oxygenated hemoglobin levels of the lower limb muscles were measured by near-infrared spectroscopy to calculate the rate of decline. This rate of decline was obtained immediately after exercise as well as at rest to calculate oxygen consumption of the lower limb muscles as expressed as a ratio of a post-exercise rate of decline to a resting one. Results The heart rate and oxygen uptake observed in PWLLE during maximal intensity were comparable to that of a 20-watt bicycle exercise or 2 km/hr walking exercise. Maximal intensity PWLLE was found to provoke muscle activity comparable to an 80-watt bicycle or 6 km/hr walking exercise. As was the case with the EMG results, during maximal intensity PWLLE, the rectus femoris muscle consumed oxygen in amounts identical to that of an 80-watt bicycle or a 6 km/hr walking exercise. Conclusion Passive weight-bearing lower limb exercise using our trial machine could provide approximately 3 MET of exercise and the thigh exhibited muscle activity equivalent to that of 80-watt

  10. Passive broadband acoustic thermometry

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  11. Innovative techniques for the production of energetic radicals for lunar processing including cold plasma processing of local planetary ores

    NASA Technical Reports Server (NTRS)

    Bullard, D.; Lynch, D. C.

    1992-01-01

    Hydrogen reduction of ilmenite has been studied by a number of investigators as a potential means for recovery of oxygen from lunar soil. Interest in this process has always rested with the simplicity of the flow diagram and the utilization of established technology. Effective utilization of hydrogen in the reduction process at temperatures of 1200 C and below has always been disappointing and, as such, has led other investigators to focus attention on other systems. Effective utilization of hydrogen in the reduction of ilmenite can be significantly enhanced in the presence of a non-equilibrium hydrogen plasma. Ilmenite at solid specimen temperatures of 600 C to 970 C were reacted in a hydrogen plasma. Those experiments revealed that hydrogen utilization can be significantly enhanced. At a specimen temperature of 850 C the fraction of H2 reacted was 24 percent compared to the 7 percent theoretical limit calculated with thermodynamic theory for the same temperature. An added advantage for a hydrogen plasma involves further reduction of TiO2. Reduction of the iron oxide in ilmenite yields TiO2 and metallic iron as by products. Titanium forms a number of oxides including TiO, Ti2O3, Ti3O5 and the Magneli oxides (Ti4O7 to Ti50O99). In conventional processing of ilmenite with hydrogen it is possible to reduce TiO2 to Ti7O13 within approximately an hour, but with poor utilization of hydrogen on the order of one mole of H2 per thousand. In the cold or non-equilibrium plasma TiO2 can be rapidly reduced to Ti2O3 with hydrogen utilization exceeding 10 percent. Based on design considerations of the plasma reactor greater utilization of the hydrogen in the reduction of TiO2 is possible.

  12. Passively actuated valve

    SciTech Connect

    Modro, S. Michael; Ougouag, Abderrafi M.

    2005-09-20

    A passively actuated valve for isolating a high pressure zone from a low pressure zone and discontinuing the isolation when the pressure in the high pressure zone drops below a preset threshold. If the pressure in the high pressure zone drops below the preset threshold, the valve opens and allows flow from the high pressure zone to the low pressure zone. The valve remains open allowing pressure equalization and back-flow should a pressure inversion between the two pressure zone occur.

  13. Active colloids that slosh through passive matrices

    NASA Astrophysics Data System (ADS)

    Zhang, Jie; Granick, Steve

    Studies of natural and artificial active matter have focused on systems with a large mismatch of the time and length scales for active and passive elements, but in a variety of non-equilibrium condensed matter systems, including numerous biological processes, actively driven elements have a crowded environment of surrounding passive ``solvent'' elements of comparable size. Here we study self-propelled colloidal particles in a passive matrix of comparable size. Particles with high activity take straight lines and sharp turns through the soft 2-D crystal matrix to ensure rapid healing of the crystal structure. Effective attraction between active particles arises when the concentration of active particles or the hardness of the matrix increases; active particles tend to segregate in the grain boundaries of the crystal matrix.

  14. Alternative to Nitric Acid Passivation Project Overview

    NASA Technical Reports Server (NTRS)

    Lewis, Pattie L.

    2013-01-01

    The standard practice for protection of stainless steel is a process called passivation. This procedure results in the formation of a metal oxide layer to prevent corrosion. Typical passivation procedures call for the use of nitric acid which exhibits excellent corrosion performance; however, there are a number of environmental, worker safety, and operational issues associated with its use. The longtime military specification for the passivation of stainless steel was cancelled in favor of newer specifications which allow for the use of citric acid in place of nitric acid. Citric acid offers a variety of benefits that include increased safety for personnel, reduced environmental impact, and reduced operational costs. There have been few studies, however, to determine whether citric acid is an acceptable alternative for NASA and DoD. This paper details activities to date including development of the joint test plan, on-going and planned testing, and preliminary results.

  15. On the kinetics of localized plasticity domains emergent at the pre-failure stage of deformation process

    NASA Astrophysics Data System (ADS)

    Orlova, Dina V.; Barannikova, Svetlana A.; Zuev, Lev B.

    2016-11-01

    The behavior of localized plasticity domains occurring at the final stage of the plastic flow process has been investigated. A series of runs was conducted on materials differing in the crystal lattice type which disclosed regular features exhibited by the flow process upon transition to macroscopic necking and viscous failure. It is found that the most distinctive regularity is the occurrence of flow domains that are moving in a concerted manner towards the pole of the bundle of domain trajectories plotted in the time-space coordinates. The deformation patterns are found to be related to the kinetics of nucleation and motion of localized plasticity fronts. The probable origin of the observed effects is considered.

  16. Ways of making-sense: Local gamma synchronization reveals differences between semantic processing induced by music and language.

    PubMed

    Barraza, Paulo; Chavez, Mario; Rodríguez, Eugenio

    2016-01-01

    Similar to linguistic stimuli, music can also prime the meaning of a subsequent word. However, it is so far unknown what is the brain dynamics underlying the semantic priming effect induced by music, and its relation to language. To elucidate these issues, we compare the brain oscillatory response to visual words that have been semantically primed either by a musical excerpt or by an auditory sentence. We found that semantic violation between music-word pairs triggers a classical ERP N400, and induces a sustained increase of long-distance theta phase synchrony, along with a transient increase of local gamma activity. Similar results were observed after linguistic semantic violation except for gamma activity, which increased after semantic congruence between sentence-word pairs. Our findings indicate that local gamma activity is a neural marker that signals different ways of semantic processing between music and language, revealing the dynamic and self-organized nature of the semantic processing.

  17. Influence of Injection Molding Process on the Local Fluctuations of Magneto-Optical Signals

    NASA Astrophysics Data System (ADS)

    Umezawa, Tomokazu; Horiguchi, Toru; Tomie, Takashi

    2001-01-01

    The local fluctuations of magneto-optical (MO) signals were investigated in the vicinity of the preformat pits of polycarbonate (PC) substrates fabricated under different injection molding conditions and also using stampers which had different shapes of grooves and preformat pits. A strong correlation was observed between the substrate birefringence and the fluctuation of the MO signal. The rate-of-change of the fluctuations, as the phase shift of the optical head was varied, was attributed to the shapes of preformat pits and grooves. The fluctuation of the MO signal could be controlled by varying the injection molding conditions and the shapes of preformat pits and grooves.

  18. Demonstration of Passive Fuel Cell Thermal Management Technology

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth A.; Jakupca, Ian; Colozza, Anthony; Wynne, Robert; Miller, Michael; Meyer, Al; Smith, William

    2012-01-01

    The NASA Glenn Research Center is developing advanced passive thermal management technology to reduce the mass and improve the reliability of space fuel cell systems for the NASA Exploration program. The passive thermal management system relies on heat conduction within highly thermally conductive cooling plates to move the heat from the central portion of the cell stack out to the edges of the fuel cell stack. Using the passive approach eliminates the need for a coolant pump and other cooling loop components within the fuel cell system which reduces mass and improves overall system reliability. Previous development demonstrated the performance of suitable highly thermally conductive cooling plates and integrated heat exchanger technology to collect the heat from the cooling plates (Ref. 1). The next step in the development of this passive thermal approach was the demonstration of the control of the heat removal process and the demonstration of the passive thermal control technology in actual fuel cell stacks. Tests were run with a simulated fuel cell stack passive thermal management system outfitted with passive cooling plates, an integrated heat exchanger and two types of cooling flow control valves. The tests were run to demonstrate the controllability of the passive thermal control approach. Finally, successful demonstrations of passive thermal control technology were conducted with fuel cell stacks from two fuel cell stack vendors.

  19. Managing two cultural identities: the malleability of bicultural identity integration as a function of induced global or local processing.

    PubMed

    Mok, Aurelia; Morris, Michael W

    2012-02-01

    Increasingly, individuals identify with two or more cultures. Prior research has found the degree to which individuals chronically integrate these identities (bicultural identity integration; BII) moderates responses to cultural cues: High BII individuals assimilate (adopting biases that are congruent with norms of the cued culture), whereas low BII individuals contrast (adopting biases that are incongruent with these norms). The authors propose BII can also be a psychological state and modulated by shifts in processing styles. In four experiments, the authors induced a global or local processing style using physical posture (Experiment 1) and cognitive manipulations (Experiments 2-4) and found that BII is enhanced in contexts facilitating a more global processing style (i.e., smiling, high-level construal, and similarity focus). The authors also found that contrastive responses to cultural cues are diminished when BII is situationally enhanced. Implications for research on processing style, identity integration, and performance in culture-based situations are discussed.

  20. [Why must we ‘master’ trust between all parties, in order to cultivate a process of sustainable local development?].

    PubMed

    Decoster, Dominique-Paule

    2014-03-01

    A sustainable territorial development process represents a society characterized by its uniqueness to the territory of implementation. This notion of territory constitutes a fact of human nature, the development of which integrates collective and individual wellbeing through an intersectoral and multidisciplinary process. When carrying out joint projects, the partnership dynamic can transform interpersonal relationships and encourage the development of trust at the very core of the sustainable local development process. This trust enables the creation of a collective territorial intelligence, based on individual and sectoral knowledge and on know-how that form a shared, intangible heritage for each of the stakeholders in the sustainable territorial development process; however, as a fact of human nature, this trust remains fragile.

  1. Hydrogen passivation of polycrystalline silicon thin films

    NASA Astrophysics Data System (ADS)

    Scheller, L.-P.; Weizman, M.; Simon, P.; Fehr, M.; Nickel, N. H.

    2012-09-01

    The influence of post-hydrogenation on the electrical and optical properties of solid phase crystallized polycrystalline silicon (poly-Si) was examined. The passivation of grain-boundary defects was measured as a function of the passivation time. The silicon dangling-bond concentration decreases with increasing passivation time due to the formation of Si-H complexes. In addition, large H-stabilized platelet-like clusters are generated. The influence of H on the electrical properties was investigated using temperature dependent conductivity and Hall-effect measurements. For poly-Si on Corning glass, the dark conductivity decreases upon hydrogenation, while it increases when the samples are fabricated on silicon-nitride covered Borofloat glass. Hall-effect measurements reveal that for poly-Si on Corning glass the hole concentration and the mobility decrease upon post-hydrogenation, while a pronounced increase is observed for poly-Si on silicon-nitride covered Borofloat glass. This indicates the formation of localized states in the band gap, which is supported by sub band-gap absorption measurments. The results are discussed in terms of hydrogen-induced defect passivation and generation mechanisms.

  2. Homogenisation processes and local effects on avifaunal composition in Italian towns

    NASA Astrophysics Data System (ADS)

    Sorace, Alberto; Gustin, Marco

    2008-01-01

    We tested whether urbanization homogenizes breeding bird communities. We compared the similarity of breeding bird communities among different urban sectors: town centres, inner periphery, outer periphery and scarcely built areas, at regional and local scale in 26 Italian towns. If urbanization causes homogenisation, the similarity of bird communities between different towns should be higher in the more urbanised sectors. We obtained data on presence of bird species in each square of the grid of urban atlases. We used the frequency of each species in each urban sector to calculate a similarity index. The similarity of the avifauna between towns was lowest in scarcely built areas and highest in the inner periphery. For each urban sector, the similarity indices between towns were negatively correlated with differences in both latitude and altitude between towns. The values of regression coefficient increased from the centre to the less urbanised sectors although the scarcely built area did not show the highest values. The frequency of a specialist group, the Mediterranean species, was negatively correlated with latitude only in the least urbanised sector. These results indicate that urbanization promotes homogenisation of biological communities. However, the similarity of avifauna between sectors in each town was higher than the similarity between different towns for the same sector. These and other findings suggest that local factors play an important role for the composition of urban bird communities.

  3. Passive drainage and biofiltration of landfill gas: results of Australian field trial.

    PubMed

    Dever, Stuart A; Swarbrick, Gareth E; Stuetz, Richard M

    2011-05-01

    A field scale trial was undertaken at a landfill site in Sydney, Australia (2004-2008), to investigate passive drainage and biofiltration of landfill gas as a means of managing landfill gas emissions from low to moderate gas generation landfill sites. The objective of the trial was to evaluate the effectiveness of a passive landfill gas drainage and biofiltration system at treating landfill gas under field conditions, and to identify and evaluate the factors that affect the behaviour and performance of the system. The trial results showed that passively aerated biofilters operating in a temperate climate can effectively oxidise methane in landfill gas, and demonstrated that maximum methane oxidation efficiencies greater than 90% and average oxidation efficiencies greater than 50% were achieved over the 4 years of operation. The trial results also showed that landfill gas loading was the primary factor that determined the behaviour and performance of the passively aerated biofilters. The landfill gas loading rate was found to control the diffusion of atmospheric oxygen into the biofilter media, limiting the microbial methane oxidation process. The temperature and moisture conditions within the biofilter were found to be affected by local climatic conditions and were also found to affect the behaviour and performance of the biofilter, but to a lesser degree than the landfill gas loading.

  4. The Contribution of Local Experiments and Negotiation Processes to Field-Level Learning in Emerging (Niche) Technologies: Meta-Analysis of 27 New Energy Projects in Europe

    ERIC Educational Resources Information Center

    Raven, Rob P. J. M.; Heiskanen, Eva; Lovio, Raimo; Hodson, Mike; Brohmann, Bettina

    2008-01-01

    This article examines how local experiments and negotiation processes contribute to social and field-level learning. The analysis is framed within the niche development literature, which offers a framework for analyzing the relation between projects in local contexts and the transfer of local experiences into generally applicable rules. The…

  5. First Came the Trees, Then the Forest: Developmental Changes during Childhood in the Processing of Visual Local-Global Patterns According to the Meaningfulness of the Stimuli

    ERIC Educational Resources Information Center

    Poirel, Nicolas; Mellet, Emmanuel; Houde, Olivier; Pineau, Arlette

    2008-01-01

    This study investigated how global and local perceptual processes evolve during childhood according to the meaningfulness of the stimuli. Children had to decide whether visually presented pairs of items were identical or not. Items consisted of global forms made up of local forms. Both global and local forms could represent either objects or…

  6. Are the satellite-observed narrow, streaky chlorophyll filaments locally intensified by the submesoscale processes?

    NASA Astrophysics Data System (ADS)

    Shulman, Igor; Penta, Bradley; Richman, James; Jacobs, Gregg; Anderson, Stephanie; Sakalaukus, Peter

    2015-05-01

    Based on observations and modeling studies we have evaluated the impact of submesoscale processes on the development and intensification of offshore narrow (5-10km wide) phytoplankton filaments during summer time in the Monterey Bay, CA. We have demonstrated that, submesoscale processes (surface frontogenesis and nonlinear Ekman transport) lead to the development of very productive phytoplankton patches along the edges between the cold jet and warm anticyclonic eddy. Our results illustrate that during persistent upwelling favorable winds, submesoscale processes can modulate the development and intensification of offshore narrow (5-10km wide) phytoplankton filaments. These processes can incubate the phytoplankton population offshore (as for example, bioluminescent dinoflagellates during August 2003). These offshore phytoplankton filaments can migrate onshore during relaxed winds following the upwelling, and be an additional source of phytoplankton bloom development in and around Monterey Bay. Therefore, the discussed offshore phytoplankton filaments may be a factor in the Bay ecosystem health, as for example, in the development of such events as harmful algae blooms (HABs). All these emphasize the importance of further observational and modeling studies of these submesoscale processes which impact the development and intensification of offshore phytoplankton filaments.

  7. Local health department translation processes: potential of machine translation technologies to help meet needs.

    PubMed

    Turner, Anne M; Mandel, Hannah; Capurro, Daniel

    2013-01-01

    Limited English proficiency (LEP), defined as a limited ability to read, speak, write, or understand English, is associated with health disparities. Despite federal and state requirements to translate health information, the vast majority of health materials are solely available in English. This project investigates barriers to translation of health information and explores new technologies to improve access to multilingual public health materials. We surveyed all 77 local health departments (LHDs) in the Northwest about translation needs, practices, barriers and attitudes towards machine translation (MT). We received 67 responses from 45 LHDs. Translation of health materials is the principle strategy used by LHDs to reach LEP populations. Cost and access to qualified translators are principle barriers to producing multilingual materials. Thirteen LHDs have used online MT tools. Many respondents expressed concerns about the accuracy of MT. Overall, respondents were positive about its potential use, if low costs and quality could be assured.

  8. Framework to trade optimality for local processing in large-scale wavefront reconstruction problems.

    PubMed

    Haber, Aleksandar; Verhaegen, Michel

    2016-11-15

    We show that the minimum variance wavefront estimation problems permit localized approximate solutions, in the sense that the wavefront value at a point (excluding unobservable modes, such as the piston mode) can be approximated by a linear combination of the wavefront slope measurements in the point's neighborhood. This enables us to efficiently compute a wavefront estimate by performing a single sparse matrix-vector multiplication. Moreover, our results open the possibility for the development of wavefront estimators that can be easily implemented in a decentralized/distributed manner, and in which the estimate optimality can be easily traded for computational efficiency. We numerically validate our approach on Hudgin wavefront sensor geometries, and the results can be easily generalized to Fried geometries.

  9. Modeling of local neural networks of the visual cortex and applications to image processing

    NASA Astrophysics Data System (ADS)

    Rybak, Ilya A.; Shevtsova, Natalia A.; Podladchikova, Lubov N.

    1991-08-01

    A model of an iso-orientation domain in the visual cortex is developed. The iso-orientation domain is represented as a neural network with retinotopically organized afferent inputs and anisotropic lateral inhibition formed by feedback connections via inhibitory interneurons. Temporal dynamics of neuron responses to oriented stimuli is studied. The results of computer simulations are compared with those of neurophysiological experiments. It is shown that the later phase of a neuron response has a more sharp orientation tuning than the initial one. It is suggested that the initial phase of a neuron response encodes intensity parameters of visual stimuli, whereas the later phase encodes its orientation. The design of the neural network preprocessor and the architecture of the system for visual information processing, based on the idea of parallel-sequential processing, are proposed. An example of a test image processing is presented.

  10. Local momentum and heat fluxes in transient transport processes and inhomogeneous systems.

    PubMed

    Chen, Youping; Diaz, Adrian

    2016-11-01

    This work examines existing formalisms for the derivation of microscopic momentum and heat fluxes. Both analytical and simulation results are provided to show that the widely used flux formulas are not applicable to transient transport processes or highly inhomogeneous systems, e.g., materials with atomically sharp interfaces. A method is formulated for formally deriving microscopic momentum and heat fluxes through the integral representation of conservation laws. The resulting flux formulas are mathematically rigorous, fully consistent with the physical concepts of momentum and heat fluxes, and applicable to nonequilibrium transient processes in atomically inhomogeneous systems with general many-body forces.

  11. Local momentum and heat fluxes in transient transport processes and inhomogeneous systems

    NASA Astrophysics Data System (ADS)

    Chen, Youping; Diaz, Adrian

    2016-11-01

    This work examines existing formalisms for the derivation of microscopic momentum and heat fluxes. Both analytical and simulation results are provided to show that the widely used flux formulas are not applicable to transient transport processes or highly inhomogeneous systems, e.g., materials with atomically sharp interfaces. A method is formulated for formally deriving microscopic momentum and heat fluxes through the integral representation of conservation laws. The resulting flux formulas are mathematically rigorous, fully consistent with the physical concepts of momentum and heat fluxes, and applicable to nonequilibrium transient processes in atomically inhomogeneous systems with general many-body forces.

  12. The impact of local processes and the prohibition of multiple links in the topological properties of directed complex networks

    NASA Astrophysics Data System (ADS)

    Esquivel-Gómez, J.; Arjona-Villicaña, P. D.; Acosta-Elías, J.

    2015-05-01

    Local processes exert influence on the growth and evolution of complex networks, which in turn shape the topological and dynamic properties of these networks. Some local processes have been researched, for example: Addition of nodes and links, rewiring of links between nodes, accelerated growth, link removal, aging, copying and multiple links prohibition. These processes impact directly into the topological and dynamical properties of complex networks. This paper introduces a new model for growth of directed complex networks which incorporates the prohibition of multiple links, addition of nodes and links, and rewiring of links. This paper also reports on the impact that these processes have in the topological properties of the networks generated with the proposed model. Numerical simulation shows that, when the frequency of rewiring increases in the proposed model, the γ exponent of the in-degree distribution approaches a value of 1.1. When the frequency of adding new links increases, the γ exponent approaches 1. That is the proposed model is able to generate all exponent values documented in real-world networks which range 1.05 < γ < 8.94.

  13. Electroless Plated Nanodiamond Coating for Stainless Steel Passivation

    SciTech Connect

    Li, D.; Korinko, P.; Spencer, W.; Stein, E.

    2016-09-15

    Tritium gas sample bottles and manifold components require passivation surface treatments to minimize the interaction of the hydrogen isotopes with surface contamination on the stainless steel containment materials. Conventional passivation processes using chemical and electrochemical means are usually insufficient to passivate tritium containment vessels and piping. Previous work demonstrated that both nitric acid and citric acid passivation on stainless steel would not prevent the catalyzed isotope exchange reaction H2 + D2 → 2HD, while electropolishing passivation resulted in surfaces that did not catalyze this hydrogen isotope exchange. The current vendor for surface passivation treatment, Tek-Vac Industries Inc., provided the best passivation technology for the stainless steel components used at SRTE. However, this vendor recently built gas sample bottles that failed to meet site criteria and has since ceased operations. The loss of this vendor created a source gap, as well as a knowledge gap. A practical and reliable robust process to develop tritium passive surfaces is needed.

  14. Cellular Localization and Processing of Primary Transcripts of Exonic MicroRNAs

    PubMed Central

    Slezak-Prochazka, Izabella; Kluiver, Joost; de Jong, Debora; Kortman, Gertrud; Halsema, Nancy; Poppema, Sibrand; Kroesen, Bart-Jan; van den Berg, Anke

    2013-01-01

    Processing of miRNAs occurs simultaneous with the transcription and splicing of their primary transcripts. For the small subset of exonic miRNAs it is unclear if the unspliced and/or spliced transcripts are used for miRNA biogenesis. We assessed endogenous levels and cellular location of primary transcripts of three exonic miRNAs. The ratio between unspliced and spliced transcripts varied markedly, i.e. >1 for BIC, <1 for pri-miR-146a and variable for pri-miR-22. Endogenous unspliced transcripts were located almost exclusively in the nucleus and thus available for miRNA processing for all three miRNAs. Endogenous spliced pri-miRNA transcripts were present both in the nucleus and in the cytoplasm and thus only partly available for miRNA processing. Overexpression of constructs containing the 5’ upstream exonic or intronic sequence flanking pre-miR-155 resulted in strongly enhanced miR-155 levels, indicating that the flanking sequence does not affect processing efficiency. Exogenously overexpressed full-length spliced BIC transcripts were present both in the nucleus and in the cytoplasm, were bound by the Microprocessor complex and resulted in enhanced miR-155 levels. We conclude that both unspliced and spliced transcripts of exonic miRNAs can be used for pre-miRNA cleavage. Splicing and cytoplasmic transport of spliced transcripts may present a mechanism to regulate levels of exonic microRNAs. PMID:24073292

  15. A Matched Field Processing Framework for Coherent Detection Over Local and Regional Networks (Postprint)

    DTIC Science & Technology

    2011-12-30

    the term " superresolution "). The single-phase matched field statistic for a given template was also demonstrated to be a viable detection statistic... Superresolution with seismic arrays using empirical matched field processing, Geophys. J. Int. 182: 1455–1477. Kim, K.-H. and Park, Y. (2010): The 20

  16. Appointing Senior Managers in Education: Homosociability, Local Logics and Authenticity in the Selection Process

    ERIC Educational Resources Information Center

    Grummell, Bernie; Devine, Dympna; Lynch, Kathleen

    2009-01-01

    While there is extensive research on educational leadership and management, the selection of leaders has received comparatively little attention. This article examines how educational leadership is constructed through the selection process in the context of a qualitative study of Irish education. It highlights the tensions that can exist for…

  17. Investigation of model based beamforming and Bayesian inversion signal processing methods for seismic localization of underground sources.

    PubMed

    Oh, Geok Lian; Brunskog, Jonas

    2014-08-01

    Techniques have been studied for the localization of an underground source with seismic interrogation signals. Much of the work has involved defining either a P-wave acoustic model or a dispersive surface wave model to the received signal and applying the time-delay processing technique and frequency-wavenumber processing to determine the location of the underground tunnel. Considering the case of determining the location of an underground tunnel, this paper proposed two physical models, the acoustic approximation ray tracing model and the finite difference time domain three-dimensional (3D) elastic wave model to represent the received seismic signal. Two localization algorithms, beamforming and Bayesian inversion, are developed for each physical model. The beam-forming algorithms implemented are the modified time-and-delay beamformer and the F-K beamformer. Inversion is posed as an optimization problem to estimate the unknown position variable using the described physical forward models. The proposed four methodologies are demonstrated and compared using seismic signals recorded by geophones set up on ground surface generated by a surface seismic excitation. The examples show that for field data, inversion for localization is most advantageous when the forward model completely describe all the elastic wave components as is the case of the FDTD 3D elastic model.

  18. Sex-specific strategy use and global-local processing: a perspective toward integrating sex differences in cognition.

    PubMed

    Pletzer, Belinda

    2014-01-01

    This article reviews the literature on sex-specific strategy use in cognitive tasks with the aim to carve out a link between sex differences in different cognitive tasks. I conclude that male strategies are commonly holistic and oriented toward global stimulus aspects, while female strategies are commonly decomposed and oriented toward local stimulus aspects. Thus, the strategies observed in different tasks, may depend on sex differences in attentional focus and hence sex differences in global-local processing. I hypothesize that strategy use may be sex hormone dependent and hence subject to change over the menstrual cycle as evidenced by findings in global-local processing and emotional memory. Furthermore, I propose sex hormonal modulation of hemispheric asymmetries as one possible neural substrate for this theory, thereby building on older theories, emphasizing the importance of sex differences in brain lateralization. The ideas described in the current article represent a perspective toward a unifying approach to the study of sex differences in cognition and their neural correlates.

  19. A trade-off between local and distributed information processing associated with remote episodic versus semantic memory.

    PubMed

    Heisz, Jennifer J; Vakorin, Vasily; Ross, Bernhard; Levine, Brian; McIntosh, Anthony R

    2014-01-01

    Episodic memory and semantic memory produce very different subjective experiences yet rely on overlapping networks of brain regions for processing. Traditional approaches for characterizing functional brain networks emphasize static states of function and thus are blind to the dynamic information processing within and across brain regions. This study used information theoretic measures of entropy to quantify changes in the complexity of the brain's response as measured by magnetoencephalography while participants listened to audio recordings describing past personal episodic and general semantic events. Personal episodic recordings evoked richer subjective mnemonic experiences and more complex brain responses than general semantic recordings. Critically, we observed a trade-off between the relative contribution of local versus distributed entropy, such that personal episodic recordings produced relatively more local entropy whereas general semantic recordings produced relatively more distributed entropy. Changes in the relative contributions of local and distributed entropy to the total complexity of the system provides a potential mechanism that allows the same network of brain regions to represent cognitive information as either specific episodes or more general semantic knowledge.

  20. Localization of the calcium-regulated citrate transport process in proximal tubule cells.

    PubMed

    Hering-Smith, Kathleen S; Mao, Weibo; Schiro, Faith R; Coleman-Barnett, Joycelynn; Pajor, Ana M; Hamm, L Lee

    2014-06-01

    Urinary citrate is an important inhibitor of calcium-stone formation. Most of the citrate reabsorption in the proximal tubule is thought to occur via a dicarboxylate transporter NaDC1 located in the apical membrane. OK cells, an established opossum kidney proximal tubule cell line, transport citrate but the characteristics change with extracellular calcium such that low calcium solutions stimulate total citrate transport as well as increase the apparent affinity for transport. The present studies address several fundamental properties of this novel process: the polarity of the transport process, the location of the calcium-sensitivity and whether NaDC1 is present in OK cells. OK cells grown on permeable supports exhibited apical >basolateral citrate transport. Apical transport of both citrate and succinate was sensitive to extracellular calcium whereas basolateral transport was not. Apical calcium, rather than basolateral, was the predominant determinant of changes in transport. Also 2,3-dimethylsuccinate, previously identified as an inhibitor of basolateral dicarboxylate transport, inhibited apical citrate uptake. Although the calcium-sensitive transport process in OK cells is functionally not typical NaDC1, NaDC1 is present in OK cells by Western blot and PCR. By immunolocalization studies, NaDC1 was predominantly located in discrete apical membrane or subapical areas. However, by biotinylation, apical NaDC1 decreases in the apical membrane with lowering calcium. In sum, OK cells express a calcium-sensitive/regulated dicarboxylate process at the apical membrane which responds to variations in apical calcium. Despite the functional differences of this process compared to NaDC1, NaDC1 is present in these cells, but predominantly in subapical vesicles.

  1. Assessing local population vulnerability to wind energy development with branching process models: an application to wind energy development

    USGS Publications Warehouse

    Erickson, Richard A.; Eager, Eric A.; Stanton, Jessica C.; Beston, Julie A.; Diffendorfer, James E.; Thogmartin, Wayne E.

    2015-01-01

    Quantifying the impact of anthropogenic development on local populations is important for conservation biology and wildlife management. However, these local populations are often subject to demographic stochasticity because of their small population size. Traditional modeling efforts such as population projection matrices do not consider this source of variation whereas individual-based models, which include demographic stochasticity, are computationally intense and lack analytical tractability. One compromise between approaches is branching process models because they accommodate demographic stochasticity and are easily calculated. These models are known within some sub-fields of probability and mathematical ecology but are not often applied in conservation biology and applied ecology. We applied branching process models to quantitatively compare and prioritize species locally vulnerable to the development of wind energy facilities. Specifically, we examined species vulnerability using branching process models for four representative species: A cave bat (a long-lived, low fecundity species), a tree bat (short-lived, moderate fecundity species), a grassland songbird (a short-lived, high fecundity species), and an eagle (a long-lived, slow maturation species). Wind turbine-induced mortality has been observed for all of these species types, raising conservation concerns. We simulated different mortality rates from wind farms while calculating local extinction probabilities. The longer-lived species types (e.g., cave bats and eagles) had much more pronounced transitions from low extinction risk to high extinction risk than short-lived species types (e.g., tree bats and grassland songbirds). High-offspring-producing species types had a much greater variability in baseline risk of extinction than the lower-offspring-producing species types. Long-lived species types may appear stable until a critical level of incidental mortality occurs. After this threshold, the risk of

  2. Passive adaptive imaging through turbulence

    NASA Astrophysics Data System (ADS)

    Tofsted, David

    2016-05-01

    Standard methods for improved imaging system performance under degrading optical turbulence conditions typically involve active adaptive techniques or post-capture image processing. Here, passive adaptive methods are considered where active sources are disallowed, a priori. Theoretical analyses of short-exposure turbulence impacts indicate that varying aperture sizes experience different degrees of turbulence impacts. Smaller apertures often outperform larger aperture systems as turbulence strength increases. This suggests a controllable aperture system is advantageous. In addition, sub-aperture sampling of a set of training images permits the system to sense tilts in different sub-aperture regions through image acquisition and image cross-correlation calculations. A four sub-aperture pattern supports corrections involving five realizable operating modes (beyond tip and tilt) for removing aberrations over an annular pattern. Progress to date will be discussed regarding development and field trials of a prototype system.

  3. Passive Tracking System and Method

    NASA Technical Reports Server (NTRS)

    Arndt, G. Dickey (Inventor); Ngo, Phong H. (Inventor); Chen, Henry A. (Inventor); Phan, Chau T. (Inventor); Bourgeois, Brian A. (Inventor); Dusl, Jon (Inventor); Hill, Brent W. (Inventor)

    2003-01-01

    Systems and methods are disclosed for passively determining the location of a moveable transmitter utilizing a pair of phase shifts at a receiver for extracting a direction vector from a receiver to the transmitter. In a preferred embodiment, a phase difference between the transmitter and receiver is extracted utilizing a noncoherent demodulator in the receiver. The receiver includes an antenna array with three antenna elements, which preferably are patch antenna elements spaced apart by one-half wavelength. Three receiver channels are preferably utilized for simultaneously processing the received signal from each of the three antenna elements. Multipath transmission paths for each of the three receiver channels are indexed so that comparisons of the same multipath component are made for each of the three receiver channels. The phase difference for each received signal is determined by comparing only the magnitudes of received and stored modulation signals to determine a winning modulation symbol.

  4. Passive Tracking System and Method

    NASA Technical Reports Server (NTRS)

    Arndt, G. Dickey (Inventor); Ngo, Phong H. (Inventor); Chen, Henry A. (Inventor); Phan, Chau T. (Inventor); Bourgeois, Brian A. (Inventor); Dusl, John (Inventor); Hill, Brent W. (Inventor)

    2005-01-01

    System and methods are disclosed for passively determining the location of a moveable transmitter utilizing a pair of phase shifts at a receiver for extracting a direction vector from a receiver to the transmitter. In a preferred embodiment, a phase difference between the transmitter and receiver is extracted utilizing a noncoherent demodulator in the receiver. The receiver includes antenna array with three antenna elements, which preferably are patch antenna elements placed apart by one-half wavelength. Three receiver channels are preferably utilized for simultaneously processing the received signal from each of the three antenna elements. Multipath transmission paths for each of the three receiver channels are indexed so that comparisons of the same multipath component are made for each of the three receiver channels. The phase difference for each received signal is determined by comparing only the magnitudes of received and stored modulation signals to determine a winning modulation symbol.

  5. Passive millimeter wave imaging

    NASA Astrophysics Data System (ADS)

    Pergande, Al; Dean, Donald D.; O'Donnell, Daniel J.

    1996-05-01

    Passive millimeter wave (MMW) imaging provides a breakthrough capability for driver vision enhancement to counter the blinding effects of inclement weather. This type of sensor images in a manner analogous to an infrared or visible camera, but receives its energy from the MMW portion of the electromagnetic spectrum. Technology has progressed to the point where MMW radiometric systems offer advantages to a number of vision applications. We report on our developmental 94 GHz radiometric testbed, and the eventual technological evolutions that will help MMW radiometers and radars meet military and commercial market needs.

  6. Optimizing passive quantum clocks

    NASA Astrophysics Data System (ADS)

    Mullan, Michael; Knill, Emanuel

    2014-10-01

    We describe protocols for passive atomic clocks based on quantum interrogation of the atoms. Unlike previous techniques, our protocols are adaptive and take advantage of prior information about the clock's state. To reduce deviations from an ideal clock, each interrogation is optimized by means of a semidefinite program for atomic state preparation and measurement whose objective function depends on the prior information. Our knowledge of the clock's state is maintained according to a Bayesian model that accounts for noise and measurement results. We implement a full simulation of a running clock with power-law noise models and find significant improvements by applying our techniques.

  7. Development of evaluation procedures for local exhaust ventilation for United States postal service mail-processing equipment.

    PubMed

    Beamer, Bryan R; Topmiller, Jennifer L; Crouch, Keith G

    2004-07-01

    Researchers from the National Institute for Occupational Safety and Health (NIOSH) have conducted several evaluations of local exhaust ventilation (LEV) systems for the United States Postal Service (USPS) since autumn 2001 when (a) terrorist(s) employed the mail system for acts of bioterrorism. As a part of the USPS 2002 Emergency Preparedness Plan, the development and installation of LEV onto USPS mail-processing equipment can reduce future exposures to operators from potentially hazardous contaminants, such as anthrax, which might be emitted during the processing of mail. This article describes how NIOSH field testing led to the development of recommended testing procedures for evaluations of LEV capture efficiency for mail-processing equipment, including tracer gas measurements, smoke release observations, air velocity measurements, and decay-rate testing under access hoods.

  8. Shell model of optimal passive-scalar mixing

    NASA Astrophysics Data System (ADS)

    Miles, Christopher; Doering, Charles

    2015-11-01

    Optimal mixing is significant to process engineering within industries such as food, chemical, pharmaceutical, and petrochemical. An important question in this field is ``How should one stir to create a homogeneous mixture while being energetically efficient?'' To answer this question, we consider an initially unmixed scalar field representing some concentration within a fluid on a periodic domain. This passive-scalar field is advected by the velocity field, our control variable, constrained by a physical quantity such as energy or enstrophy. We consider two objectives: local-in-time (LIT) optimization (what will maximize the mixing rate now?) and global-in-time (GIT) optimization (what will maximize mixing at the end time?). Throughout this work we use the H-1 mix-norm to measure mixing. To gain a better understanding, we provide a simplified mixing model by using a shell model of passive-scalar advection. LIT optimization in this shell model gives perfect mixing in finite time for the energy-constrained case and exponential decay to the perfect-mixed state for the enstrophy-constrained case. Although we only enforce that the time-average energy (or enstrophy) equals a chosen value in GIT optimization, interestingly, the optimal control keeps this value constant over time.

  9. Passive drainage and biofiltration of landfill gas: Australian field trial

    SciTech Connect

    Dever, S.A. . E-mail: stuart_dever@ghd.com.au; Swarbrick, G.E. . E-mail: g.swarbrick@unsw.edu.au; Stuetz, R.M. . E-mail: r.stuetz@unsw.edu.au

    2007-07-01

    In Australia a significant number of landfill waste disposal sites do not incorporate measures for the collection and treatment of landfill gas. This includes many old/former landfill sites, rural landfill sites, non-putrescible solid waste and inert waste landfill sites, where landfill gas generation is low and it is not commercially viable to extract and beneficially utilize the landfill gas. Previous research has demonstrated that biofiltration has the potential to degrade methane in landfill gas, however, the microbial processes can be affected by many local conditions and factors including moisture content, temperature, nutrient supply, including the availability of oxygen and methane, and the movement of gas (oxygen and methane) to/from the micro-organisms. A field scale trial is being undertaken at a landfill site in Sydney, Australia, to investigate passive drainage and biofiltration of landfill gas as a means of managing landfill gas emissions at low to moderate gas generation landfill sites. The design and construction of the trial is described and the experimental results will provide in-depth knowledge on the application of passive gas drainage and landfill gas biofiltration under Sydney (Australian) conditions, including the performance of recycled materials for the management of landfill gas emissions.

  10. Using GIBS and Worldview to Connect Global Processes to Local Events

    NASA Astrophysics Data System (ADS)

    Meyer, D. J.

    2015-12-01

    The NASA Worldview client and undelrying Global Image Browse Service (GIBS) are powerful tools for visualizing dynamic global processes in a clear and understandable manner. Currently viewable data layers, such as sea surface temperature, cloud and aersol parameters, snow cover and sea ice, and fires can be observed over time to gain a better understanding of the interrleationship between land, ocean and atmospheric processes, and how these relationships evolve over time. This presentation demonstrates the use of these tools to visualize (for example) relationships between fire and air quality over North America, the evolution of the recent El Nino, and changes in sea ice extent, using Worldview directly, and GIBS through both open source and commercial applications. The presentation also discusses visualizations that will be possible with anticipated new data layers.

  11. Cold plasma processing of local planetary ores for oxygen and metallurgically important metals

    NASA Technical Reports Server (NTRS)

    Lynch, D. C.; Bullard, D.; Ortega, R.

    1990-01-01

    The utilization of a cold plasma in chlorination processing is described. Essential equipment and instruments were received, the experimental apparatus assembled and tested, and preliminary experiments conducted. The results of the latter lend support to the original hypothesis: a cold plasma can both significantly enhance and bias chemical reactions. In two separate experiments, a cold plasma was used to reduce TiCl4 vapor and chlorinate ilmenite. The latter, reacted in an argon-chlorine plasma, yielded oxygen. The former experiment reveals that chlorine can be recovered as HCl vapor from metal chlorides in a hydrogen plasma. Furthermore, the success of the hydrogen experiments has lead to an analysis of the feasibility of direct hydrogen reduction of metal oxides in a cold plasma. That process would produce water vapor and numerous metal by-products.

  12. Atomic-Scale Surface Local Structure of TiO2 and Its Influence on the Water Photooxidation Process.

    PubMed

    Imanishi, Akihito; Fukui, Ken-Ichi

    2014-06-19

    The water photooxidation reaction on TiO2 and related metal oxides has been attracting strong attention from the point of view of solar water splitting. The water photooxidation reaction (i.e., oxygen evolution reaction) accompanies three other kinds of side reactions (photoluminescence (PL), surface roughening, and nonradiative recombination). These reactions are competitive with each other, and the ratio of their quantum efficiencies strongly depends on the atomic-scale surface local structure. This Perspective focuses on the atomic-scale surface local structure dependence of those four kinds of competitive reactions on a TiO2 (rutile) single-crystal electrode on which not only a terrace structure but also step structures were strictly controlled. The experimental results are discussed based on the reaction model of water photooxidation that we previously proposed. The photocatalytic activity of the TiO2 surface roughened by the photoinduced roughening process is also focused on.

  13. Development and Testing of an Ultra Low Power System-On-Chip (SOC) Platform for Marine Mammal Tags and Passive Acoustic Signal Processing

    DTIC Science & Technology

    2014-09-30

    a block diagram of the SoC based system. The digital portion of the chip includes a general purpose microcontroller for fully programmable...to a NVM. It has a programmable 16b MSP430 microcontroller and hardware accelerators for programmable FFT, FIR filtering, Cordic co-processing, and...the Vcap to a 1.2V and 0.5V supply, which are leveraged by the microcontroller in active, sleep and deep sleep modes. Once the Vcap is charged, the

  14. Institutions and Cultural Diversity: Effects of Democratic and Propaganda Processes on Local Convergence and Global Diversity

    PubMed Central

    Ulloa, Roberto; Kacperski, Celina; Sancho, Fernando

    2016-01-01

    In a connected world where people influence each other, what can cause a globalized monoculture, and which measures help to preserve the coexistence of cultures? Previous research has shown that factors such as homophily, population size, geography, mass media, and type of social influence play important roles. In the present paper, we investigate for the first time the impact that institutions have on cultural diversity. In our first three studies, we extend existing agent-based models and explore the effects of institutional influence and agent loyalty. We find that higher institutional influence increases cultural diversity, while individuals' loyalty to their institutions has a small, preserving effect. In three further studies, we test how bottom-up and top-down processes of institutional influence impact our model. We find that bottom-up democratic practices, such as referenda, tend to produce convergence towards homogeneity, while top-down information dissemination practices, such as propaganda, further increase diversity. In our last model—an integration of bottom-up and top-down processes into a feedback loop of information—we find that when democratic processes are rare, the effects of propaganda are amplified, i.e., more diversity emerges; however, when democratic processes are common, they are able to neutralize or reverse this propaganda effect. Importantly, our models allow for control over the full spectrum of diversity, so that a manipulation of our parameters can result in preferred levels of diversity, which will be useful for the study of other factors in the future. We discuss possible mechanisms behind our results, applications, and implications for political and social sciences. PMID:27058247

  15. Institutions and Cultural Diversity: Effects of Democratic and Propaganda Processes on Local Convergence and Global Diversity.

    PubMed

    Ulloa, Roberto; Kacperski, Celina; Sancho, Fernando

    2016-01-01

    In a connected world where people influence each other, what can cause a globalized monoculture, and which measures help to preserve the coexistence of cultures? Previous research has shown that factors such as homophily, population size, geography, mass media, and type of social influence play important roles. In the present paper, we investigate for the first time the impact that institutions have on cultural diversity. In our first three studies, we extend existing agent-based models and explore the effects of institutional influence and agent loyalty. We find that higher institutional influence increases cultural diversity, while individuals' loyalty to their institutions has a small, preserving effect. In three further studies, we test how bottom-up and top-down processes of institutional influence impact our model. We find that bottom-up democratic practices, such as referenda, tend to produce convergence towards homogeneity, while top-down information dissemination practices, such as propaganda, further increase diversity. In our last model--an integration of bottom-up and top-down processes into a feedback loop of information--we find that when democratic processes are rare, the effects of propaganda are amplified, i.e., more diversity emerges; however, when democratic processes are common, they are able to neutralize or reverse this propaganda effect. Importantly, our models allow for control over the full spectrum of diversity, so that a manipulation of our parameters can result in preferred levels of diversity, which will be useful for the study of other factors in the future. We discuss possible mechanisms behind our results, applications, and implications for political and social sciences.

  16. Local Navon letter processing affects skilled behavior: a golf-putting experiment.

    PubMed

    Lewis, Michael B; Dawkins, Gemma

    2015-04-01

    Expert or skilled behaviors (for example, face recognition or sporting performance) are typically performed automatically and with little conscious awareness. Previous studies, in various domains of performance, have shown that activities immediately prior to a task demanding a learned skill can affect performance. In sport, describing the to-be-performed action is detrimental, whereas in face recognition, describing a face or reading local Navon letters is detrimental. Two golf-putting experiments are presented that compare the effects that these three tasks have on experienced and novice golfers. Experiment 1 found a Navon effect on golf performance for experienced players. Experiment 2 found, for experienced players only, that performance was impaired following the three tasks described above, when compared with reading or global Navon tasks. It is suggested that the three tasks affect skilled performance by provoking a shift from automatic behavior to a more analytic style. By demonstrating similarities between effects in face recognition and sporting behavior, it is hoped to better understand concepts in both fields.

  17. Reconstructing Past Admixture Processes from Local Genomic Ancestry Using Wavelet Transformation.

    PubMed

    Sanderson, Jean; Sudoyo, Herawati; Karafet, Tatiana M; Hammer, Michael F; Cox, Murray P

    2015-06-01

    Admixture between long-separated populations is a defining feature of the genomes of many species. The mosaic block structure of admixed genomes can provide information about past contact events, including the time and extent of admixture. Here, we describe an improved wavelet-based technique that better characterizes ancestry block structure from observed genomic patterns. principal components analysis is first applied to genomic data to identify the primary population structure, followed by wavelet decomposition to develop a new characterization of local ancestry information along the chromosomes. For testing purposes, this method is applied to human genome-wide genotype data from Indonesia, as well as virtual genetic data generated using genome-scale sequential coalescent simulations under a wide range of admixture scenarios. Time of admixture is inferred using an approximate Bayesian computation framework, providing robust estimates of both admixture times and their associated levels of uncertainty. Crucially, we demonstrate that this revised wavelet approach, which we have released as the R package adwave, provides improved statistical power over existing wavelet-based techniques and can be used to address a broad range of admixture questions.

  18. Chemo-Dynamical Evolution of r-process Elements in the Local Group Galaxies

    NASA Astrophysics Data System (ADS)

    Hirai, Yutaka; Ishimaru, Yuhri; Saitoh, Takayuki R.; Fujii, Michiko S.; Hidaka, Jun; Kajino, Toshitaka

    The astrophysical site(s) of r-process is not yet identified over half a century. Astronomical high dispersion observations have shown that extremely metal-poor (EMP) stars in the Milky Way (MW) halo have large star-to-star dispersions in the abundance of r-process elements. Binary neutron star mergers (NSMs) are one of the most promising sites of r-process. However, several studies suggested that it is difficult to reproduce the dispersions by NSMs due to their long merger times and low rates. In this study, we performed a series of N-body/smoothed particle hydrodynamic simulations of dwarf galaxies. We show that NSMs can explain the dispersions with long merger times (˜100 Myr). We find that the metallicity of our simulated galaxies does not correlate with time in their early phase due to slow chemical enrichment. This slow chemical enrichment produces [Eu/Fe] distribution which is consistent with the observation. Our results suggest that stars in the MW halo formed with a low star formation rate of less than 10 - 3M ȯ yr-1, which is common for typical dwarf galaxies in the MW. Our simulations support the scenario that early enrichment of the MW halo occurred in the framework of hierarchical structure formation.

  19. Visual Search Targeting Either Local or Global Perceptual Processes Differs as a Function of Autistic-Like Traits in the Typically Developing Population

    ERIC Educational Resources Information Center

    Almeida, Renita A.; Dickinson, J. Edwin; Maybery, Murray T.; Badcock, Johanna C.; Badcock, David R.

    2013-01-01

    Relative to low scorers, high scorers on the Autism-Spectrum Quotient (AQ) show enhanced performance on the Embedded Figures Test and the Radial Frequency search task (RFST), which has been attributed to both enhanced local processing and differences in combining global percepts. We investigate the role of local and global processing further using…

  20. Local Information Processing in Adults with High Functioning Autism and Asperger Syndrome: The Usefulness of Neuropsychological Tests and Self-Reports

    ERIC Educational Resources Information Center

    Spek, Annelies A.; Scholte, Evert M.; Van Berckelaer-Onnes, Ina A.

    2011-01-01

    Local information processing in 42 adults with high functioning autism, 41 adults with Asperger syndrome and 41 neurotypical adults was examined. Contrary to our expectations, the disorder groups did not outperform the neurotypical group in the neuropsychological measures of local information processing. In line with our hypotheses, the…

  1. Realistic Drawing Talent in Typical Adults Is Associated with the Same Kind of Local Processing Bias Found in Individuals with ASD

    ERIC Educational Resources Information Center

    Drake, Jennifer E.; Winner, Ellen

    2011-01-01

    A local processing bias has been found in individuals with autism as well as in typical children with a gift for drawing realistically. This study investigated whether a local processing bias in typical adults is more strongly associated with drawing realism or autistic-like traits. Forty-two adults made an observational drawing (scored for…

  2. [Investigation on remote measurement of air pollution by a method of infrared passive scanning imaging].

    PubMed

    Jiao, Yang; Xu, Liang; Gao, Min-Guang; Feng, Ming-Chun; Jin, Ling; Tong, Jing-Jing; Li, Sheng

    2012-07-01

    Passive remote sensing by Fourier-transform infrared (FTIR) spectrometry allows detection of air pollution. However, for the localization of a leak and a complete assessment of the situation in the case of the release of a hazardous cloud, information about the position and the distribution of a cloud is essential. Therefore, an imaging passive remote sensing system comprising an interferometer, a data acquisition and processing software, scan system, a video system, and a personal computer has been developed. The remote sensing of SF6 was done. The column densities of all directions in which a target compound has been identified may be retrieved by a nonlinear least squares fitting algorithm and algorithm of radiation transfer, and a false color image is displayed. The results were visualized by a video image, overlaid by false color concentration distribution image. The system has a high selectivity, and allows visualization and quantification of pollutant clouds.

  3. Synergistic Effect of Sodium Chlorite and Edible Coating on Quality Maintenance of Minimally Processed Citrus grandis under Passive and Active MAP.

    PubMed

    Ban, Zhaojun; Feng, Jianhua; Wei, Wenwen; Yang, Xiangzheng; Li, Jilan; Guan, Junfeng; Li, Jiang

    2015-08-01

    Edible coating has been an innovation within the bioactive packaging concept. The comparative analysis upon the effect of edible coating, sodium chlorite (SC) and their combined application on quality maintenance of minimally processed pomelo (Citrus grandis) fruits during storage at 4 °C was conducted. Results showed that the combination of edible coating and SC dipping delayed the microbial development whereas the sole coating or dipping treatment was less efficient. The synergetic application of edible coating and SC treatment under modified atmosphere packaging (MAP, 10% O2 , 10% CO2 ) was able to maintain the total soluble solids level and ascorbic acid content, while reduce the weight loss as well as development of mesophiles and psychrotrophs. Nonetheless, the N, O-carboxymethyl chitosan solely coated samples showed significantly higher level of weight loss during storage with comparison to the untreated sample. Furthermore, the combined application of edible coating and SC dipping under active MAP best maintained the sensory quality of minimally processed pomelo fruit during storage.

  4. Numerical experiments on the influence of melt and serpentinization on passive margin structure

    NASA Astrophysics Data System (ADS)

    Tetreault, Joya; Buiter, Susanne

    2014-05-01

    Passive margins are often classified as magma-rich or magma-poor, with distinctly different crustal architectures. For example, end-member magma-rich margins have thick sequences of seaward-dipping reflectors, short necking zones, and thick oceanic crusts, whereas many magma-poor margins have wide necking zones, hyper-extended crust, and exhumed serpentinized mantle. Melt and magmatic processes can strongly affect the mantle and crust during various stages of extension. At late stages of extension, serpentinization of upper mantle rocks will also affect crustal strength. We aim to study the influence of melt and serpentinization on structures developed during passive margin formation. Melt and serpentinization are two processes that can alter crust and mantle rheologic properties during different stages of extension. Introducing melt into a rift system will alter the thermal field, rheology, and density of crust and lithosphere. The presence of large amounts of melt (7-8%) in upper mantle rocks will significantly lower the viscosity. In addition, depleted mantle rocks can have significant loss of water that would result in raising the viscosity by about a factor of 100. Intrusion and underplating of magma to the lower crust can cause metamorphism and thus density and rheological changes of the surrounding crust. Furthermore, analogue experiments have shown that magmatic underplating will induce strain localization in the crust during extension. In regions such as the magma-poor margins of the North Atlantic, the serpentinization of mantle peridotites after sufficient thinning of continental crust can lead to strain localization that will subsequently affect the margin architecture. Upper mantle rocks become serpentinized at temperatures lower than 400 degrees when seawater infiltrates. The lower frictional properties that serpentinized peridotites have at these temperatures work to localize strain and allow detachment faults to form. We use 2D numerical experiments

  5. Processing and Breakdown Localization Rresults For an L-Band Standing-Wave Cavity

    SciTech Connect

    Wang, Faya; Adolphsen, Chris; /SLAC

    2009-08-03

    An L-band (1.3 GHz), normal-conducting, 5-cell, standing-wave cavity that was built as a prototype capture accelerator for the ILC is being high-power processed at SLAC. The goal is to demonstrate stable operation at 15 MV/m with 1 msec, 5 Hz pulses and the cavity immersed in a 0.5 Telsa solenoidal magnetic field. This paper summarizes the performance that was ultimately achieved and describes a novel analysis of the modal content of the stored energy in the cavity after a breakdown to determine on which iris it occurred.

  6. The influence of local- and landscape-scale processes on spatial self-organization in estuarine ecosystems.

    PubMed

    van de Koppel, Johan; Bouma, Tjeerd J; Herman, Peter M J

    2012-03-15

    Complexity theory proposes that spatial self-organization, the process whereby small-scale, localized interactions among the components of a system generate complex spatial structures at large spatial scales, explains the formation of autogenic spatial patterns in ecosystems. We question this premise by reviewing three estuarine ecosystems - mussel beds, mudflats and salt marshes - where self-organization has been put forward to explain spatial patterns. Our review highlights that these self-organized estuarine systems are shaped by the combination of small-scale interactions between ecological and physical processes on the one hand, and large-scale physical forcing on the other. More specifically, local interactions generate patchiness at small spatial scales, whereas landscape forcing determines the shape and orientation of these patches in the landscape. We present a framework that illustrates how self-organized ecosystems are shaped by interactions between organisms and physical processes occurring at multiple spatial scales. Moreover, the present review of estuarine systems underlines that scale-dependent feedbacks are capable of explaining spatial patterns that are much more complex than the regular patterns to which they have been applied so far.

  7. NMDA-dependent mechanisms only affect the BOLD response in the rat dentate gyrus by modifying local signal processing

    PubMed Central

    Tiede, Regina; Krautwald, Karla; Fincke, Anja; Angenstein, Frank

    2012-01-01

    The role of N-methyl--aspartate (NMDA) receptor-mediated mechanisms in the formation of a blood oxygen level-dependent (BOLD) response was studied using electrical stimulation of the right perforant pathway. Stimulation of this fiber bundle triggered BOLD responses in the right hippocampal formation and in the left entorhinal cortex. The perforant pathway projects to and activates the dentate gyrus monosynaptically, activation in the contralateral entorhinal cortex is multisynaptic and requires forwarding and processing of signals. Application of the NMDA receptor antagonist MK801 during stimulation had no effect on BOLD responses in the right dentate gyrus, but reduced the BOLD responses in the left entorhinal cortex. In contrast, application of MK801 before the first stimulation train reduced the BOLD response in both regions. Electrophysiological recordings revealed that the initial stimulation trains changed the local processing of the incoming signals in the dentate gyrus. This altered electrophysiological response was not further changed by a subsequent application of MK801, which is in agreement with an unchanged BOLD response. When MK801 was present during the first stimulation train, a dissimilar electrophysiological response pattern was observed and corresponds to an altered BOLD response, indicating that NMDA-dependent mechanisms indirectly affect the BOLD response, mainly via modifying local signal processing and subsequent propagation. PMID:22167232

  8. Photometric Passive Range Sensor

    NASA Astrophysics Data System (ADS)

    Argueta-Diaz, Victor; García-Valenzuela, Augusto

    2008-04-01

    In this paper we present a passive optical ranging method that consists of taking several photometric measurements from the light radiated by an object and deriving the range from these measurements. This passive ranging device uses an iris of radius a, a lens of radius larger than a, and a photodetector of radius p

  9. Fly ash carbon passivation

    DOEpatents

    La Count, Robert B; Baltrus, John P; Kern, Douglas G

    2013-05-14

    A thermal method to passivate the carbon and/or other components in fly ash significantly decreases adsorption. The passivated carbon remains in the fly ash. Heating the fly ash to about 500 and 800 degrees C. under inert gas conditions sharply decreases the amount of surfactant adsorbed by the fly ash recovered after thermal treatment despite the fact that the carbon content remains in the fly ash. Using oxygen and inert gas mixtures, the present invention shows that a thermal treatment to about 500 degrees C. also sharply decreases the surfactant adsorption of the recovered fly ash even though most of the carbon remains intact. Also, thermal treatment to about 800 degrees C. under these same oxidative conditions shows a sharp decrease in surfactant adsorption of the recovered fly ash due to the fact that the carbon has been removed. This experiment simulates the various "carbon burnout" methods and is not a claim in this method. The present invention provides a thermal method of deactivating high carbon fly ash toward adsorption of AEAs while retaining the fly ash carbon. The fly ash can be used, for example, as a partial Portland cement replacement in air-entrained concrete, in conductive and other concretes, and for other applications.

  10. Passive bistatic radar analysis

    NASA Astrophysics Data System (ADS)

    O'Hagan, Daniel W.; Kuschel, H.; Schiller, Joachim

    2009-06-01

    Passive Bistatic Radar (PBR) research is at its zenith with several notable PBR systems currently operational, or available for deployment. Such PBRs include the Manastash Ridge Radar (MRR) developed for and by academia; Silent Sentry developed as a commercial concern by Lockheed Martin; and Homeland Alerter (HA100) also a commercial system developed by Thales. However at present, despite the existence of numerous PBR prototypes, take up of commercial passive radar technology remains slow. This is due in part to technology immaturity, in part to politics, and particularly due to the fact that monostatic radars perform so well. If PBRs are to enjoy longevity as a viable technology then it is imperative that they address certain niche application areas, with the aforementioned MRR being one prime example of this. The focus of this paper will be an analysis of a PBR system that utilised FM radio signals of opportunity to detect aircraft targets with an RCS generally not lower than 20 m2. The paper will demonstrate the theoretical detection coverage of an FM based PBR operating in a severe interference environment.

  11. Effectiveness and Sensitivity of Vibration Processing Techniques for Local Fault Detection in Gears

    NASA Astrophysics Data System (ADS)

    Dalpiaz, G.; Rivola, A.; Rubini, R.

    2000-05-01

    This paper deals with gear condition monitoring based on vibration analysis techniques. The detection and diagnostic capability of some of the most effective techniques are discussed and compared on the basis of experimental results, concerning a gear pair affected by a fatigue crack. In particular, the results of new approaches based on time-frequency and cyclostationarity analysis are compared against those obtained by means of the well-accepted cepstrum analysis and time-synchronous average analysis. Moreover, the sensitivity to fault severity is assessed by considering two different depths of the crack. The effect of transducer location and processing options are also shown. In the case of the experimental results considered in this paper, the power cepstrum is practically insensitive to the crack evolution. Conversely, the spectral correlation density function is able to monitor the fault development and does not seem to be significantly influenced by the transducer position. Analysis techniques of the time-synchronous average, such as the 'residual' signal and the demodulation technique, are able to localise the damaged tooth; however, the sensitivity of the demodulation technique is strongly dependent on the proper choice of the filtering band and affected by the transducer location. The wavelet transform seems to be a good tool for crack detection; it is particularly effective if the residual part of the time-synchronous averaged signal is processed.

  12. Passive-solar construction handbook

    SciTech Connect

    Levy, E.; Evans, D.; Gardstein, C.

    1981-02-01

    Many of the basic elements of passive solar design are reviewed. Passive solar construction is covered according to system type, each system type discussion including a general discussion of the important design and construction issues which apply to the particular system and case studies illustrating designed and built examples of the system type. The three basic types of passive solar systems discussed are direct gain, thermal storage wall, and attached sunspace. Thermal performance and construction information is presented for typical materials used in passive solar collector components, storage components, and control components. Appended are an overview of analysis methods and a technique for estimating performance. (LEW)

  13. Surface passivation optimization using DIRECT

    NASA Astrophysics Data System (ADS)

    Graf, Peter A.; Kim, Kwiseon; Jones, Wesley B.; Wang, Lin-Wang

    2007-06-01

    We describe a systematic and efficient method of determining pseudo-atom positions and potentials for use in nanostructure calculations based on bulk empirical pseudopotentials (EPMs). Given a bulk EPM for binary semiconductor X, we produce parameters for pseudo-atoms necessary to passivate a nanostructure of X in preparation for quantum mechanical electronic structure calculations. These passivants are based on the quality of the wave functions of a set of small test structures that include the passivants. Our method is based on the global optimization method DIRECT. It enables and/or streamlines surface passivation for empirical pseudopotential calculations.

  14. The influence of niobium and vanadium on passivity of titanium-based implants in physiological solution.

    PubMed

    Metikos-Huković, M; Kwokal, A; Piljac, J

    2003-09-01

    Surface films play a key role in corrosion and osteointegration processes of titanium-based orthopedic implants. The influence of niobium and vanadium as alloying elements on titanium alloy passivity have been investigated in Hanks' Balanced Salt Solution (HBSS), at 37 degrees C and pH 6.9.Ti6Al4V and Ti6Al6Nb have been considered. The excellent passivating properties of the anodically formed Ti(IV)-based surface oxide film and high corrosion resistance of the Ti6Al6Nb alloy have been attributed to the stabilizing effect of Nb(5+) cations on the passive film, by annihilation of stoichiometric defects (anion vacancies) caused by the presence of titanium suboxides. Localized corrosion sensitivity of the Ti6Al4V alloy has been correlated to the dissolution of vanadium at the surface film/electrolyte interface coupled with generation of cation vacancies and their diffusion through the film as a part of the solid-state diffusion process. The presence of a high concentration of chloride ions (0.15gl(-1)) in HBSS further accelerates these processes.

  15. Solar air-conditioning-active, hybrid and passive

    SciTech Connect

    Yellott, J. I.

    1981-04-01

    After a discussion of summer air conditioning requirements in the United States, active, hybrid, and passive cooling systems are defined. Active processes and systems include absorption, Rankine cycle, and a small variety of miscellaneous systems. The hybrid solar cooling and dehumidification technology of desiccation is covered as well as evaporative cooling. The passive solar cooling processes covered include convective, radiative and evaporative cooling. Federal and state involvement in solar cooling is then discussed. (LEW)

  16. What can be Learned from X-ray Spectroscopy Concerning Hot Gas in Local Bubble and Charge Exchange Processes?

    NASA Technical Reports Server (NTRS)

    Snowden, Steve

    2007-01-01

    What can be learned from x-ray spectroscopy in observing hot gas in local bubble and charge exchange processes depends on spectral resolution, instrumental grasp, instrumental energy band, signal-to-nose, field of view, angular resolution and observatory location. Early attempts at x-ray spectroscopy include ROSAT; more recently, astronomers have used diffuse x-ray spectrometers, XMM Newton, sounding rocket calorimeters, and Suzaku. Future observations are expected with calorimeters on the Spectrum Roentgen Gamma mission, and the Solar Wind Charge Exchange (SWCX). The Geospheric SWCX may provide remote sensing of the solar wind and magnetosheath and remote observations of solar CMEs moving outward from the sun.

  17. An assessment of the impact of local processes on dust lifting in martian climate models

    NASA Astrophysics Data System (ADS)

    Mulholland, David P.; Spiga, Aymeric; Listowski, Constantino; Read, Peter L.

    2015-05-01

    Simulation of the lifting of dust from the planetary surface is of substantially greater importance on Mars than on Earth, due to the fundamental role that atmospheric dust plays in the former's climate, yet the dust emission parameterisations used to date in martian global climate models (MGCMs) lag, understandably, behind their terrestrial counterparts in terms of sophistication. Recent developments in estimating surface roughness length over all martian terrains and in modelling atmospheric circulations at regional to local scales (less than O(100 km)) presents an opportunity to formulate an improved wind stress lifting parameterisation. We have upgraded the conventional scheme by including the spatially varying roughness length in the lifting parameterisation in a fully consistent manner (thereby correcting a possible underestimation of the true threshold level for wind stress lifting), and used a modification to account for deviations from neutral stability in the surface layer. Following these improvements, it is found that wind speeds at typical MGCM resolution never reach the lifting threshold at most gridpoints: winds fall particularly short in the southern midlatitudes, where mean roughness is large. Sub-grid scale variability, manifested in both the near-surface wind field and the surface roughness, is then considered, and is found to be a crucial means of bridging the gap between model winds and thresholds. Both forms of small-scale variability contribute to the formation of dust emission 'hotspots': areas within the model gridbox with particularly favourable conditions for lifting, namely a smooth surface combined with strong near-surface gusts. Such small-scale emission could in fact be particularly influential on Mars, due both to the intense positive radiative feedbacks that can drive storm growth and a strong hysteresis effect on saltation. By modelling this variability, dust lifting is predicted at the locations at which dust storms are frequently

  18. Single-thread channels resulting from a localization process driven by vegetation

    NASA Astrophysics Data System (ADS)

    Narteau, C.; Tal, M.

    2009-12-01

    The unpredictable manner in which braided rivers evolve is in stark contrast to the orderly migration pattern of meandering rivers driven by erosion along outer bends and deposition along inner banks. Braided channels are the default pattern that develops when an unbounded water flow interacts with noncohesive sediment. A series of laboratory experiments demonstrated that plants alone are able to achieve the two key mechanisms to developing meandering: slowing the rate of widening and discouraging channel cutoffs. Plants initially colonized braid-bars that were emergent during low flow. By adding cohesion to the sediment and increasing roughness, vegetation deterred the flow from reoccupying areas which were colonized. By decreasing erosion rates, plants made it possible for deposition along the inner bank to match the rate of erosion along the outer bank. This enabled the channel to develop sinuosity and migrate laterally while suppressing channel splitting and the creation of new channel width. Areas with established vegetation provided stable conditions which promoted new seedling establishment and expansion of the vegetated area. A generic mechanism of width production in the braided state is the opportunistic creation of new channels. As existing flow paths become slightly less favorable, for example by bar deposition or an increase in sinuosity, new ones are readily created in areas that are not currently occupied by flow. By making it more difficult for flow to occupy vegetated areas, plants in effect decouple the transition between wet and dry areas, making it harder for areas that are dry (vegetated) to turn wet (reoccupied by flow) and less likely for areas that are wet to become dry. The net effect is localization of the flow into a single-thread channel with transitions between wet and dry occurring predominantly along the channel margin and driving lateral migration while a single-thread channel remains intact. We are using a 1D cellular automata model

  19. Processing and intracellular localization of rice stripe virus Pc2 protein in insect cells

    SciTech Connect

    Zhao, Shuling; Zhang, Gaozhan; Dai, Xuejuan; Hou, Yanling; Li, Min; Liang, Jiansheng; Liang, Changyong

    2012-08-01

    Rice stripe virus (RSV) belongs to the genus Tenuivirus and its genome consists of four single-stranded RNAs encoding seven proteins. Here, we have analyzed the processing and membrane association of Pc2 encoded by vcRNA2 in insect cells. The enhanced green fluorescent protein (eGFP) was fused to the Pc2 and used for the detection of Pc2 fusion proteins. The results showed that Pc2 was cleaved to produce two proteins named Pc2-N and Pc2-C. When expressed alone, either Pc2-N or Pc2-C could transport to the Endoplasmic reticulum (ER) membranes independently. Further mutagenesis studies revealed that Pc2 contained three ER-targeting domains. The results led us to propose a model for the topology of the Pc2 in which an internal signal peptide immediately followed a cleavage site, and two transmembrane regions are contained.

  20. Cold plasma processing of local planetary ores for oxygen and metallurgically important metals

    NASA Technical Reports Server (NTRS)

    Lynch, D. C.; Bullard, D.; Ortega, R.

    1991-01-01

    The utilization of a cold or nonequilibrium plasma in chlorination processing is discussed. Titanium dioxide (TiO2) was successfully chlorinated at temperatures between 700 and 900 C without the aid of carbon. In addition to these initial experiments, a technique was developed for determining the temperature of a specimen in a plasma. Development of that technique has required evaluating the emissivity of TiO2, ZrO2, and FeOTiO2 and analyzing the specimen temperature in a plasma as a function of both power absorbed by the plasma and the pressure of the plasma. The mass spectrometer was also calibrated with TiCl4 and CCl4 vapor.

  1. Correlation Processing Of Local Seismic Data: Applications for Autonomous Sensor Deployments

    SciTech Connect

    Dodge, D A

    2010-11-16

    Excavation and operation of an underground facility is likely to produce an extensive suite of seismic signals observable at the surface for perhaps several km. Probably a large fraction of such signals will be correlated, so the design of a monitoring framework should include consideration of a correlation processing capability. Correlation detectors have been shown to be significantly more sensitive than beam-forming power detectors. Although correlation detectors have a limited detection footprint, they can be generalized into multi-rank subspace detectors which are sensitive over a much larger range of source mechanisms and positions. Production of subspace detectors can be automated, so their use in an autonomous framework may be contemplated. Waveform correlation also can be used to produce very high precision phase picks which may be jointly inverted to simultaneously relocate groups of events. The relative precision of the resulting hypocenters is sufficient to visualize structural detail at a scale of less than a few tens of meters. Three possible correlation processor systems are presented. All use a subspace signal detection framework. The simplest system uses a single-component sensor and is capable of detection and classification of signals. The most complicated system uses many sensors deployed around the facility, and is capable of detection, classification, and high-precision source location. Data from a deep underground mine are presented to demonstrate the applicability of correlation processing to monitoring an underground facility. Although the source region covers an area of about 600m by 580m, all but two of the events form clusters at a threshold of 0.7. All the events could have been detected and classified by the subspace detection framework, and high-precision picks can be computed for all cluster members.

  2. Antigen processing of glycoconjugate vaccines; the polysaccharide portion of the pneumococcal CRM(197) conjugate vaccine co-localizes with MHC II on the antigen processing cell surface.

    PubMed

    Lai, Zengzu; Schreiber, John R

    2009-05-21

    Pneumococcal (Pn) polysaccharides (PS) are T-independent (TI) antigens and do not induce immunological memory or antibodies in infants. Conjugation of PnPS to the carrier protein CRM(197) induces PS-specific antibody in infants, and memory similar to T-dependent (Td) antigens. Conjugates have improved immunogenicity via antigen processing and presentation of carrier protein with MHC II and recruitment of T cell help, but the fate of the PS attached to the carrier is unknown. To determine the location of the PS component of PnPS-CRM(197) in the APC, we separately labeled PS and protein and tracked their location. The PS of types 14-CRM(197) and 19F-CRM(197) was specifically labeled by Alexa Fluor 594 hydrazide (red). The CRM(197) was separately labeled red in a reaction that did not label PS. Labeled antigens were incubated with APC which were fixed, permeabilized and incubated with anti-MHC II antibody labeled green by Alexa Fluor 488, followed by confocal microscopy. Labeled CRM(197) was presented on APC surface and co-localized with MHC II (yellow). Labeled unconjugated 14 or 19F PS did not go to the APC surface, but PS labeled 14-CRM(197) and 19F-CRM(197) was internalized and co-localized with MHC II. Monoclonal antibody to type 14 PS bound to intracellular type 14 PS and PS-CRM(197). Brefeldin A and chloroquine blocked both CRM(197) and PS labeled 14-CRM(197) and 19F-CRM(197) from co-localizing with MHC II. These data suggest that the PS component of the CRM(197) glycoconjugate enters the endosome, travels with CRM(197) peptides to the APC surface and co-localizes with MHC II.

  3. Searching for life motion signals. Visual search asymmetry in local but not global biological-motion processing.

    PubMed

    Wang, Li; Zhang, Kan; He, Sheng; Jiang, Yi

    2010-08-01

    The visual search paradigm has been widely used to study the mechanisms underlying visual attention, and search asymmetry provides a source of insight into preattentive visual features. In the current study, we tested visual search with biological-motion stimuli that were spatially scrambled or that represented feet only and found that observers were more efficient in searching for an upright target among inverted distractors than in searching for an inverted target among upright distractors. This suggests that local biological-motion signals can act as a basic preattentive feature for the human visual system. The search asymmetry disappeared when the global configuration in biological motion was kept intact, which indicates that the attentional effects arising from biological features (e.g., local motion signals) and global novelty (e.g., inverted human figure) can interact and modulate visual search. Our findings provide strong evidence that local biological motion can be processed independently of global configuration and shed new light on the mechanisms of visual search asymmetry.

  4. Electron-beam-induced deposition and post-treatment processes to locally generate clean titanium oxide nanostructures on Si(100).

    PubMed

    Schirmer, M; Walz, M-M; Vollnhals, F; Lukasczyk, T; Sandmann, A; Chen, C; Steinrück, H-P; Marbach, H

    2011-02-25

    We have investigated the lithographic generation of TiO(x) nanostructures on Si(100) via electron-beam-induced deposition (EBID) of titanium tetraisopropoxide (TTIP) in ultra-high vacuum (UHV) by scanning electron microscopy (SEM) and local Auger electron spectroscopy (AES). In addition, the fabricated nanostructures were also characterized ex situ via atomic force microscopy (AFM) under ambient conditions. In EBID, a highly focused electron beam is used to locally decompose precursor molecules and thereby to generate a deposit. A drawback of this nanofabrication technique is the unintended deposition of material in the vicinity of the impact position of the primary electron beam due to so-called proximity effects. Herein, we present a post-treatment procedure to deplete the unintended deposits by moderate sputtering after the deposition process. Moreover, we were able to observe the formation of pure titanium oxide nanocrystals (<100 nm) in situ upon heating the sample in a well-defined oxygen atmosphere. While the nanocrystal growth for the as-deposited structures also occurs in the surroundings of the irradiated area due to proximity effects, it is limited to the pre-defined regions, if the sample was sputtered before heating the sample under oxygen atmosphere. The described two-step post-treatment procedure after EBID presents a new pathway for the fabrication of clean localized nanostructures.

  5. Electron-beam-induced deposition and post-treatment processes to locally generate clean titanium oxide nanostructures on Si(100)

    NASA Astrophysics Data System (ADS)

    Schirmer, M.; Walz, M.-M.; Vollnhals, F.; Lukasczyk, T.; Sandmann, A.; Chen, C.; Steinrück, H.-P.; Marbach, H.

    2011-02-01

    We have investigated the lithographic generation of TiOx nanostructures on Si(100) via electron-beam-induced deposition (EBID) of titanium tetraisopropoxide (TTIP) in ultra-high vacuum (UHV) by scanning electron microscopy (SEM) and local Auger electron spectroscopy (AES). In addition, the fabricated nanostructures were also characterized ex situ via atomic force microscopy (AFM) under ambient conditions. In EBID, a highly focused electron beam is used to locally decompose precursor molecules and thereby to generate a deposit. A drawback of this nanofabrication technique is the unintended deposition of material in the vicinity of the impact position of the primary electron beam due to so-called proximity effects. Herein, we present a post-treatment procedure to deplete the unintended deposits by moderate sputtering after the deposition process. Moreover, we were able to observe the formation of pure titanium oxide nanocrystals (<100 nm) in situ upon heating the sample in a well-defined oxygen atmosphere. While the nanocrystal growth for the as-deposited structures also occurs in the surroundings of the irradiated area due to proximity effects, it is limited to the pre-defined regions, if the sample was sputtered before heating the sample under oxygen atmosphere. The described two-step post-treatment procedure after EBID presents a new pathway for the fabrication of clean localized nanostructures.

  6. Controlling local order of athermal self-propelled particles

    NASA Astrophysics Data System (ADS)

    Dougan, Niamh; Crowther, Peter; Royall, C. Patrick; Turci, Francesco

    2016-12-01

    We consider a model of self-propelled dynamics for athermal active particles, where the non-equilibrium active forces are modelled by a Ornstein-Uhlenbeck process. In the limit of no-driving force, the model reduces to the passive, Brownian dynamics of an atomistic glass forming fluid, the Wahnström binary mixture. The Wahnström mixture is known to show strong correlations between the emergence of slow dynamics and the formation of locally favoured structures based on icosahedra. Here, we study how the non-equilibrium driving affects the local structure of the system, and find that it strongly promotes icosahedral order. The states rich in local icosahedral order correspond to configurations of very low potential energy, suggesting that the non-equilibrium dynamics in the self propelled model can be effectively exploited to explore the potential energy surface of the binary mixture and have access to states that are difficult to attain using passive dynamics.

  7. A Novel Pre-Processing Technique for Original Feature Matrix of Electronic Nose Based on Supervised Locality Preserving Projections

    PubMed Central

    Jia, Pengfei; Huang, Tailai; Wang, Li; Duan, Shukai; Yan, Jia; Wang, Lidan

    2016-01-01

    An electronic nose (E-nose) consisting of 14 metal oxide gas sensors and one electronic chemical gas sensor has been constructed to identify four different classes of wound infection. However, the classification results of the E-nose are not ideal if the original feature matrix containing the maximum steady-state response value of sensors is processed by the classifier directly, so a novel pre-processing technique based on supervised locality preserving projections (SLPP) is proposed in this paper to process the original feature matrix before it is put into the classifier to improve the performance of the E-nose. SLPP is good at finding and keeping the nonlinear structure of data; furthermore, it can provide an explicit mapping expression which is unreachable by the traditional manifold learning methods. Additionally, some effective optimization methods are found by us to optimize the parameters of SLPP and the classifier. Experimental results prove that the classification accuracy of support vector machine (SVM combined with the data pre-processed by SLPP outperforms other considered methods. All results make it clear that SLPP has a better performance in processing the original feature matrix of the E-nose. PMID:27376295

  8. Simulation of plasma based semiconductor processing using block structured locally refined grids

    SciTech Connect

    Wake, D.D.

    1998-01-01

    We have described a new numerical method for plasma simulation. Calculations have been presented which show that the method is accurate and suggest the regimes in which the method provides savings in CPU time and memory requirements. A steady state simulation of a four centimeter domain was modeled with sheath scale (150 microns) resolution using only 40 grid points. Simulations of semiconductor processing equipment have been performed which imply the usefulness of the method for engineering applications. It is the author`s opinion that these accomplishments represent a significant contribution to plasma simulation and the efficient numerical solution of certain systems of non-linear partial differential equations. More work needs to be done, however, for the algorithm to be of practical use in an engineering environment. Despite our success at avoiding the dielectric relaxation timestep restrictions the algorithm is still conditionally stable and requires timesteps which are relatively small. This represents a prohibitive runtime for steady state solutions on high resolution grids. Current research suggests that these limitations may be overcome and the use of much larger timesteps will be possible.

  9. The structure of turbulent channel flow with passive scalar transport

    NASA Technical Reports Server (NTRS)

    Guezennec, Y.; Stretch, D.; Kim, J.

    1990-01-01

    The simulation of turbulent channel flow, with various passive markers, was examined to investigate the local mechanisms of passive scalar transport. We found significant differences between the local transport of heat and momentum, even when the molecular and turbulent Prandtl numbers are of order one. These discrepancies can be attributed to the role of the pressure. We also found that the heat is a poor marker of the vorticity field outside of the near wall region and that scalar transport over significant distances results from the aggregate effect of many turbulent eddies.

  10. Passive states for essential observers

    NASA Astrophysics Data System (ADS)

    Strich, Robert

    2008-02-01

    The aim of this note is to present a unified approach to the results given by Borchers and Buchholz ["Global properties of vacuum states in de Sitter space," Ann. Inst. Henri Poincare, Sect. A. 70, 23-40 (1999)] and by Buchholz and Summers ["Stable quantum systems in anti-de Sitter space: Causality, independence and spectral properties," J. Math. Phys. 45, 4810-4831 (2004)] which also covers examples of models not presented in these two papers (e.g., d-dimensional Minkowski space-time for d ⩾3). Assuming that a state is passive for an observer traveling along certain (essential) worldlines, we show that this state is invariant under the isometry group, is a temperature equilibrium state for the observer at a temperature uniquely determined by the structure constants of the Lie algebra involved, and fulfills (a variant of) the Reeh-Schlieder property. Also, the modular objects associated with such a state and the observable algebra of an observer are computed and a version of weak locality is examined.

  11. Passive states for essential observers

    SciTech Connect

    Strich, Robert

    2008-02-15

    The aim of this note is to present a unified approach to the results given by Borchers and Buchholz ['Global properties of vacuum states in de Sitter space', Ann. Inst. Henri Poincare, Sect. A. 70, 23-40 (1999)] and by Buchholz and Summers ['Stable quantum systems in anti-de Sitter space: Causality, independence and spectral properties', J. Math. Phys. 45, 4810-4831 (2004)] which also covers examples of models not presented in these two papers (e.g., d-dimensional Minkowski space-time for d{>=}3). Assuming that a state is passive for an observer traveling along certain (essential) worldlines, we show that this state is invariant under the isometry group, is a temperature equilibrium state for the observer at a temperature uniquely determined by the structure constants of the Lie algebra involved, and fulfills (a variant of) the Reeh-Schlieder property. Also, the modular objects associated with such a state and the observable algebra of an observer are computed and a version of weak locality is examined.

  12. Forecasting phenological responses to climate change: Using hierarchical models to bridge local processes and regional predictions (Invited)

    NASA Astrophysics Data System (ADS)

    Diez, J.; Ibanez, I.

    2010-12-01

    Species’ phenological responses to climate change have large implications for future species distributions, trophic interactions, and ecosystem processes. Analyses of historical databases have shown that these responses are often species-specific and spatially variable. This variability makes predicting future responses more challenging. At the root of this challenge is the fundamental problem in ecology of how locally variable processes scale up to yield regional patterns. In this study, we show how hierarchical models of species phenological responses to climate may help address this challenge. Using long-term datasets (1953-2005) from the Japanese Meteorological Service for Morus bombysis (mulberry) at 100 sites distributed across Japan, we developed models using both monthly and daily climate data to predict bud burst dates. In both cases, hierarchical models were used to translate the different local responses among sites into more realistic predictions across the region and at unmeasured locations. The daily models represent a new approach to predicting phenology that is flexible enough to incorporate different mechanisms that may be important for some species, including forcing, chilling, photoperiod, and extreme events such as frosts. We use the daily models to show how spatial variability in bud burst dates results in part from different mechanisms being more important in different parts of the country. We compare these results to the monthly models to contrast the predictive value of the more detailed models. Our results emphasize the general utility of hierarchical models for understanding and forecasting regional changes in phenology, regardless of the specific model employed.

  13. Super-resolution and super-localization microscopy: A novel tool for imaging chemical and biological processes

    SciTech Connect

    Dong, Bin

    2015-01-01

    Optical microscopy imaging of single molecules and single particles is an essential method for studying fundamental biological and chemical processes at the molecular and nanometer scale. The best spatial resolution (~ λ/2) achievable in traditional optical microscopy is governed by the diffraction of light. However, single molecule-based super-localization and super-resolution microscopy imaging techniques have emerged in the past decade. Individual molecules can be localized with nanometer scale accuracy and precision for studying of biological and chemical processes.This work uncovered the heterogeneous properties of the pore structures. In this dissertation, the coupling of molecular transport and catalytic reaction at the single molecule and single particle level in multilayer mesoporous nanocatalysts was elucidated. Most previous studies dealt with these two important phenomena separately. A fluorogenic oxidation reaction of non-fluorescent amplex red to highly fluorescent resorufin was tested. The diffusion behavior of single resorufin molecules in aligned nanopores was studied using total internal reflection fluorescence microscopy (TIRFM).

  14. Results of a Demonstration Assessment of Passive System Reliability Utilizing the Reliability Method for Passive Systems (RMPS)

    SciTech Connect

    Bucknor, Matthew; Grabaskas, David; Brunett, Acacia; Grelle, Austin

    2015-04-26

    Advanced small modular reactor designs include many advantageous design features such as passively driven safety systems that are arguably more reliable and cost effective relative to conventional active systems. Despite their attractiveness, a reliability assessment of passive systems can be difficult using conventional reliability methods due to the nature of passive systems. Simple deviations in boundary conditions can induce functional failures in a passive system, and intermediate or unexpected operating modes can also occur. As part of an ongoing project, Argonne National Laboratory is investigating various methodologies to address passive system reliability. The Reliability Method for Passive Systems (RMPS), a systematic approach for examining reliability, is one technique chosen for this analysis. This methodology is combined with the Risk-Informed Safety Margin Characterization (RISMC) approach to assess the reliability of a passive system and the impact of its associated uncertainties. For this demonstration problem, an integrated plant model of an advanced small modular pool-type sodium fast reactor with a passive reactor cavity cooling system is subjected to a station blackout using RELAP5-3D. This paper discusses important aspects of the reliability assessment, including deployment of the methodology, the uncertainty identification and quantification process, and identification of key risk metrics.

  15. Individualized Gaussian process-based prediction and detection of local and global gray matter abnormalities in elderly subjects

    PubMed Central

    Ziegler, G.; Ridgway, G.R.; Dahnke, R.; Gaser, C.

    2014-01-01

    Structural imaging based on MRI is an integral component of the clinical assessment of patients with potential dementia. We here propose an individualized Gaussian process-based inference scheme for clinical decision support in healthy and pathological aging elderly subjects using MRI. The approach aims at quantitative and transparent support for clinicians who aim to detect structural abnormalities in patients at risk of Alzheimer's disease or other types of dementia. Firstly, we introduce a generative model incorporating our knowledge about normative decline of local and global gray matter volume across the brain in elderly. By supposing smooth structural trajectories the models account for the general course of age-related structural decline as well as late-life accelerated loss. Considering healthy subjects' demography and global brain parameters as informative about normal brain aging variability affords individualized predictions in single cases. Using Gaussian process models as a normative reference, we predict new subjects' brain scans and quantify the local gray matter abnormalities in terms of Normative Probability Maps (NPM) and global z-scores. By integrating the observed expectation error and the predictive uncertainty, the local maps and global scores exploit the advantages of Bayesian inference for clinical decisions and provide a valuable extension of diagnostic information about pathological aging. We validate the approach in simulated data and real MRI data. We train the GP framework using 1238 healthy subjects with ages 18–94 years, and predict in 415 independent test subjects diagnosed as healthy controls, Mild Cognitive Impairment and Alzheimer's disease. PMID:24742919

  16. Commentary on "Capturing the Evasive Passive"

    ERIC Educational Resources Information Center

    Lillo-Martin, Diane; Snyder, William

    2009-01-01

    Passives has been the focus of much research in language acquisition since the 1970s. It has been clear from this research that young children seldom produce passives spontaneously, particularly "long" or "full" passives with a by-phrase; and they usually perform poorly on experimental tests of the comprehension of passives, especially passives of…

  17. Passive containment cooling system

    DOEpatents

    Billig, Paul F.; Cooke, Franklin E.; Fitch, James R.

    1994-01-01

    A passive containment cooling system includes a containment vessel surrounding a reactor pressure vessel and defining a drywell therein containing a non-condensable gas. An enclosed wetwell pool is disposed inside the containment vessel, and a gravity driven cooling system (GDCS) pool is disposed above the wetwell pool in the containment vessel and is vented to the drywell. An isolation pool is disposed above the GDCS pool and includes an isolation condenser therein. The condenser has an inlet line disposed in flow communication with the drywell for receiving the non-condensable gas along with any steam released therein following a loss-of-coolant accident (LOCA). The condenser also has an outlet line disposed in flow communication with the drywell for returning to the drywell both liquid condensate produced upon cooling of the steam and the non-condensable gas for reducing pressure within the containment vessel following the LOCA.

  18. Passive containment cooling system

    DOEpatents

    Billig, P.F.; Cooke, F.E.; Fitch, J.R.

    1994-01-25

    A passive containment cooling system includes a containment vessel surrounding a reactor pressure vessel and defining a drywell therein containing a non-condensable gas. An enclosed wetwell pool is disposed inside the containment vessel, and a gravity driven cooling system (GDCS) pool is disposed above the wetwell pool in the containment vessel and is vented to the drywell. An isolation pool is disposed above the GDCS pool and includes an isolation condenser therein. The condenser has an inlet line disposed in flow communication with the drywell for receiving the non-condensable gas along with any steam released therein following a loss-of-coolant accident (LOCA). The condenser also has an outlet line disposed in flow communication with the drywell for returning to the drywell both liquid condensate produced upon cooling of the steam and the non-condensable gas for reducing pressure within the containment vessel following the LOCA. 1 figure.

  19. Passive magnetic bearing system

    DOEpatents

    Post, Richard F.

    2014-09-02

    An axial stabilizer for the rotor of a magnetic bearing provides external control of stiffness through switching in external inductances. External control also allows the stabilizer to become a part of a passive/active magnetic bearing system that requires no external source of power and no position sensor. Stabilizers for displacements transverse to the axis of rotation are provided that require only a single cylindrical Halbach array in its operation, and thus are especially suited for use in high rotation speed applications, such as flywheel energy storage systems. The elimination of the need of an inner cylindrical array solves the difficult mechanical problem of supplying support against centrifugal forces for the magnets of that array. Compensation is provided for the temperature variation of the strength of the magnetic fields of the permanent magnets in the levitating magnet arrays.

  20. Subject, Topic and Sesotho Passive.

    ERIC Educational Resources Information Center

    Demuth, Katherine

    1990-01-01

    Analysis of Sesotho-speaking children's spontaneous language showed that the acquisition of passives was closely linked to the fact that Sesotho subjects must be discourse topics. It is suggested that a detailed analysis of how passive constructions interact with other components of a given linguistic system is critical for developing coherent and…

  1. Temperature initiated passive cooling system

    DOEpatents

    Forsberg, Charles W.

    1994-01-01

    A passive cooling system for cooling an enclosure only when the enclosure temperature exceeds a maximum standby temperature comprises a passive heat transfer loop containing heat transfer fluid having a particular thermodynamic critical point temperature just above the maximum standby temperature. An upper portion of the heat transfer loop is insulated to prevent two phase operation below the maximum standby temperature.

  2. Temperature initiated passive cooling system

    DOEpatents

    Forsberg, C.W.

    1994-11-01

    A passive cooling system for cooling an enclosure only when the enclosure temperature exceeds a maximum standby temperature comprises a passive heat transfer loop containing heat transfer fluid having a particular thermodynamic critical point temperature just above the maximum standby temperature. An upper portion of the heat transfer loop is insulated to prevent two phase operation below the maximum standby temperature. 1 fig.

  3. Passive retrofits for Navy housing

    SciTech Connect

    Hibbert, R.; Miles, C.; Jones, R.; Peck, C.; Anderson, J.; Jacobson, V.; Dale, A.M.

    1985-01-01

    A project to assess and initiate passive solar energy retrofits to US Navy family housing is described. The current data base for Navy housing (ECOP), and its enhancement for passive solar purposes options proposed for Navy housing are explained. The analysis goals and methods to evaluate the retrofits are discussed. An educational package to explain the retrofits is described.

  4. The importance of local and landscape-scale processes to the occupancy of wetlands by pond-breeding amphibians

    USGS Publications Warehouse

    Scherer, Rick D.; Muths, Erin; Noon, Barry R.

    2012-01-01

    Variation in the distribution and abundance of species across landscapes has traditionally been attributed to processes operating at fine spatial scales (i.e., environmental conditions at the scale of the sampling unit), but processes that operate across larger spatial scales such as seasonal migration or dispersal are also important. To determine the relative importance of these processes, we evaluated hypothesized relationships between the probability of occupancy in wetlands by two amphibians [wood frogs (Lithobates sylvaticus) and boreal chorus frogs (Pseudacris maculata)] and attributes of the landscape measured at three spatial scales in Rocky Mountain National Park, Colorado. We used cost-based buffers and least-cost distances to derive estimates of landscape attributes that may affect occupancy patterns from the broader spatial scales. The most highly ranked models provide strong support for a positive relationship between occupancy by breeding wood frogs and the amount of streamside habitat adjacent to a wetland. The model selection results for boreal chorus frogs are highly uncertain, though several of the most highly ranked models indicate a positive association between occupancy and the number of neighboring, occupied wetlands. We found little evidence that occupancy of either species was correlated with local-scale attributes measured at the scale of individual wetlands, suggesting that processes operating at broader scales may be more important in influencing occupancy patterns in amphibian populations.

  5. A Study on an In-Process Laser Localized Pre-Deposition Heating Approach to Reducing FDM Part Anisotropy

    NASA Astrophysics Data System (ADS)

    Kurapatti Ravi, Abinesh

    Material extrusion based rapid prototyping systems have been used to produce prototypes for several years. They have been quite important in the additive manufacturing field, and have gained popularity in research, development and manufacturing in a wide field of applications. There has been a lot of interest in using these technologies to produce end use parts, and Fused Deposition Modeling (FDM) has gained traction in leading the transition of rapid prototyping technologies to rapid manufacturing. But parts built with the FDM process exhibit property anisotropy. Many studies have been conducted into process optimization, material properties and even post processing of parts, but were unable to solve the strength anisotropy issue. To address this, an optical heating system has been proposed to achieve localized heating of the pre- deposition surface prior to material deposition over the heated region. This occurs in situ within the build process, and aims to increase the interface temperature to above glass transition (Tg), to trigger an increase in polymer chain diffusion, and in extension, increase the strength of the part. An increase in flexural strength by 95% at the layer interface has been observed when the optical heating method was implemented, thereby improving property isotropy of the FDM part. This approach can be designed to perform real time control of inter-filament and interlayer temperatures across the build volume of a part, and can be tuned to achieve required mechanical properties.

  6. Passive solar manufactured buildings development and analyses

    NASA Astrophysics Data System (ADS)

    Dekieffer, R.

    1983-11-01

    Manufactured buildings which are cost effective residential and light commercial buildings are discussed. The solar energy research institute (SERI) and the Department of Energy (DOE) worked with building manufacturers design, develop, and build passive solar manufactured buildings. This development process lead to valuable information in design development and design options, cost analysis, and estimated and monitored thermal performance on all types of manufactured buildings. The scope and content are described.

  7. Passive degassing at Nyiragongo (D.R. Congo) and Etna (Italy) volcanoes: the chemical characterization of the emissions and assessment of their uptake of trace elements emissions on the local environment

    NASA Astrophysics Data System (ADS)

    Calabrese, Sergio; Scaglione, Sarah; Milazzo, Silvia; D'Alessandro, Walter; Bobrowski, Nicole; Giuffrida, Giovanni; Tedesco, Dario; Parello, Francesco

    2014-05-01

    Volcanoes are well known as an impressive large natural source of trace elements into the troposphere. Among others, Etna (Italy) and Nyiragongo (D.R. Congo), two noteworthy emitters on Earth, are two stratovolcanoes located in different geological settings, both characterized by persistent passive degassing from their summit craters. Here, we present some results on trace element composition in volcanic plume emissions, atmospheric bulk deposition (rainwater) and their uptake of the surrounding vegetation, with the aim to compare and identify differences and similarities between this these two volcanoes. Volcanic emissions were sampled by using active filter-pack for acid gases (sulfur and halogens) and specific teflon filters for particulates (major and trace elements). The impact of the volcanogenic deposition in the surrounding of the crater rims was investigated by using different sampling techniques: bulk rain collectors gauges were used to collect atmospheric bulk deposition, and biomonitoring technique was carried out to collect gases and particulates by using endemic plant species. Concentrations of major and trace elements of volcanic plume emissions (gases and particulates) were obtained by elution and microwave digestion of the collected filters: sulfur and halogens were determined by ion chromatography and ICP-MS, and untreated filters for particulate were acid digested and analysed by ICP-OES and ICP-MS. Rain water and plant samples were also analysed for major and trace elements by using ICP-OES and ICP-MS. In total 55 elements were determined. The estimates of the trace element fluxes confirm that Etna and Nyiragongo are large sources of metals to the atmosphere, especially considering their persistent state of passive degassing. In general, chemical composition of the volcanic aerosol particles of both volcanoes is characterized by two main components: one is related to the silicic component produced by magma bursting and fragmentation, enriching

  8. Application of damage detection methods using passive reconstruction of impulse response functions.

    PubMed

    Tippmann, J D; Zhu, X; Lanza di Scalea, F

    2015-02-28

    In structural health monitoring (SHM), using only the existing noise has long been an attractive goal. The advances in understanding cross-correlations in ambient noise in the past decade, as well as new understanding in damage indication and other advanced signal processing methods, have continued to drive new research into passive SHM systems. Because passive systems take advantage of the existing noise mechanisms in a structure, offshore wind turbines are a particularly attractive application due to the noise created from the various aerodynamic and wave loading conditions. Two damage detection methods using a passively reconstructed impulse response function, or Green's function, are presented. Damage detection is first studied using the reciprocity of the impulse response functions, where damage introduces new nonlinearities that break down the similarity in the causal and anticausal wave components. Damage detection and localization are then studied using a matched-field processing technique that aims to spatially locate sources that identify a change in the structure. Results from experiments conducted on an aluminium plate and wind turbine blade with simulated damage are also presented.

  9. Folding in and out: passive morphing in flapping wings.

    PubMed

    Stowers, Amanda K; Lentink, David

    2015-03-25

    We present a new mechanism for passive wing morphing of flapping wings inspired by bat and bird wing morphology. The mechanism consists of an unactuated hand wing connected to the arm wing with a wrist joint. Flapping motion generates centrifugal accelerations in the hand wing, forcing it to unfold passively. Using a robotic model in hover, we made kinematic measurements of unfolding kinematics as functions of the non-dimensional wingspan fold ratio (2-2.5) and flapping frequency (5-17 Hz) using stereo high-speed cameras. We find that the wings unfold passively within one to two flaps and remain unfolded with only small amplitude oscillations. To better understand the passive dynamics, we constructed a computer model of the unfolding process based on rigid body dynamics, contact models, and aerodynamic correlations. This model predicts the measured passive unfolding within about one flap and shows that unfolding is driven by centrifugal acceleration induced by flapping. The simulations also predict that relative unfolding time only weakly depends on flapping frequency and can be reduced to less than half a wingbeat by increasing flapping amplitude. Subsequent dimensional analysis shows that the time required to unfold passively is of the same order of magnitude as the flapping period. This suggests that centrifugal acceleration can drive passive unfolding within approximately one wingbeat in small and large wings. Finally, we show experimentally that passive unfolding wings can withstand impact with a branch, by first folding and then unfolding passively. This mechanism enables flapping robots to squeeze through clutter without sophisticated control. Passive unfolding also provides a new avenue in morphing wing design that makes future flapping morphing wings possibly more energy efficient and light-weight. Simultaneously these results point to possible inertia driven, and therefore metabolically efficient, control strategies in bats and birds to morph or recover

  10. Natural fracture characterization using passive seismic illumination

    SciTech Connect

    Nihei, K.T.

    2003-01-08

    The presence of natural fractures in reservoir rock can significantly enhance gas production, especially in tight gas formations. Any general knowledge of the existence, location, orientation, spatial density, and connectivity of natural fractures, as well as general reservoir structure, that can be obtained prior to active seismic acquisition and drilling can be exploited to identify key areas for subsequent higher resolution active seismic imaging. Current practices for estimating fracture properties before the acquisition of surface seismic data are usually based on the assumed geology and tectonics of the region, and empirical or fracture mechanics-based relationships between stratigraphic curvature and fracturing. The objective of this research is to investigate the potential of multicomponent surface sensor arrays, and passive seismic sources in the form of local earthquakes to identify and characterize potential fractured gas reservoirs located near seismically active regions. To assess the feasibility of passive seismic fracture detection and characterization, we have developed numerical codes for modeling elastic wave propagation in reservoir structures containing multiple, finite-length fractures. This article describes our efforts to determine the conditions for favorable excitation of fracture converted waves, and to develop an imaging method that can be used to locate and characterize fractures using multicomponent, passive seismic data recorded on a surface array.

  11. Complementary resistive switches for passive nanocrossbar memories.

    PubMed

    Linn, Eike; Rosezin, Roland; Kügeler, Carsten; Waser, Rainer

    2010-05-01

    On the road towards higher memory density and computer performance, a significant improvement in energy efficiency constitutes the dominant goal in future information technology. Passive crossbar arrays of memristive elements were suggested a decade ago as non-volatile random access memories (RAM) and can also be used for reconfigurable logic circuits. As such they represent an interesting alternative to the conventional von Neumann based computer chip architectures. Crossbar architectures hold the promise of a significant reduction in energy consumption because of their ultimate scaling potential and because they allow for a local fusion of logic and memory, thus avoiding energy consumption by data transfer on the chip. However, the expected paradigm change has not yet taken place because the general problem of selecting a designated cell within a passive crossbar array without interference from sneak-path currents through neighbouring cells has not yet been solved satisfactorily. Here we introduce a complementary resistive switch. It consists of two antiserial memristive elements and allows for the construction of large passive crossbar arrays by solving the sneak path problem in combination with a drastic reduction of the power consumption.

  12. Brookfield Homes Passive House Performance Evaluation

    SciTech Connect

    Herk, A.; Poerschke, A.; Beach, R.

    2016-02-04

    In 2012-2013, IBACOS worked with a builder, Brookfield Homes in Denver, Colorado, to design and construct a Passive House certified model home. IBACOS used several modeling programs and calculation methods to complete the final design package along with Brookfield's architect KGA Studio. This design package included upgrades to the thermal enclosure, basement insulation, windows, and heating, ventilation, and air conditioning. Short-term performance testing in the Passive House was done during construction and after construction. Testing with a blower door indicated that whole-building air leakage to the outside was 324 CFM and 0.60 ACH50. The other two test homes had little short-term testing done post-construction by the local energy rater. IBACOS then monitored the energy consumption and whole-house comfort conditions of that occupied Passive House after one year of operation and compared the monitoring results to those for two other occupied test houses in the same area with similar square footage but slightly different floor plans. IBACOS also assisted the builder, Brookfield Homes, in researching design scenarios for Zero Energy Ready Home and ENERGY STAR acceptance levels. IBACOS also assisted Brookfield in conceptualizing product for Denver's Brighton Heights area. Brookfield was considering building to Zero Energy Ready Home standards in that location. IBACOS provided strategies that Brookfield may draw from in the event the builder chooses to pursue a Zero Energy Ready Home plan for that market.

  13. Passive autonomous infrared sensor technology

    NASA Astrophysics Data System (ADS)

    Sadjadi, Firooz

    1987-10-01

    This study was conducted in response to the DoD's need for establishing understanding of algorithm's modules for passive infrared sensors and seekers and establishing a standardized systematic procedure for applying this understanding to DoD applications. We quantified the performances of Honeywell's Background Adaptive Convexity Operator Region Extractor (BACORE) detection and segmentation modules, as functions of a set of image metrics for both single-frame and multiframe processing. We established an understanding of the behavior of the BACORE's internal parameters. We characterized several sets of stationary and sequential imagery and extracted TIR squared, TBIR squared, ESR, and range for each target. We generated a set of performance models for multi-frame processing BACORE that could be used to predict the behavior of BACORE in image metric space. A similar study was conducted for another of Honeywell's segmentors, namely Texture Boundary Locator (TBL), and its performances were quantified. Finally, a comparison of TBL and BACORE on the same data base and same number of frames was made.

  14. A multiscale maximum entropy moment closure for locally regulated space-time point process models of population dynamics.

    PubMed

    Raghib, Michael; Hill, Nicholas A; Dieckmann, Ulf

    2011-05-01

    The prevalence of structure in biological populations challenges fundamental assumptions at the heart of continuum models of population dynamics based only on mean densities (local or global). Individual-based models (IBMs) were introduced during the last decade in an attempt to overcome this limitation by following explicitly each individual in the population. Although the IBM approach has been quite useful, the capability to follow each individual usually comes at the expense of analytical tract ability, which limits the generality of the statements that can be made. For the specific case of spatial structure in populations of sessile (and identical) organisms, space-time point processes with local regulation seem to cover the middle ground between analytical tract ability and a higher degree of biological realism. This approach has shown that simplified representations of fecundity, local dispersal and density-dependent mortality weighted by the local competitive environment are sufficient to generate spatial patterns that mimic field observations. Continuum approximations of these stochastic processes try to distill their fundamental properties, and they keep track of not only mean densities, but also higher order spatial correlations. However, due to the non-linearities involved they result in infinite hierarchies of moment equations. This leads to the problem of finding a 'moment closure'; that is, an appropriate order of (lower order) truncation, together with a method of expressing the highest order density not explicitly modelled in the truncated hierarchy in terms of the lower order densities. We use the principle of constrained maximum entropy to derive a closure relationship for truncation at second order using normalisation and the product densities of first and second orders as constraints, and apply it to one such hierarchy. The resulting 'maxent' closure is similar to the Kirkwood superposition approximation, or 'power-3' closure, but it is

  15. Recurrent fractal neural networks: a strategy for the exchange of local and global information processing in the brain.

    PubMed

    Bieberich, Erhard

    2002-01-01

    The regulation of biological networks relies significantly on convergent feedback signaling loops that render a global output locally accessible. Ideally, the recurrent connectivity within these systems is self-organized by a time-dependent phase-locking mechanism. This study analyzes recurrent fractal neural networks (RFNNs), which utilize a self-similar or fractal branching structure of dendrites and downstream networks for phase-locking of reciprocal feedback loops: output from outer branch nodes of the network tree enters inner branch nodes of the dendritic tree in single neurons. This structural organization enables RFNNs to amplify re-entrant input by over-the-threshold signal summation from feedback loops with equivalent signal traveling times. The columnar organization of pyramidal neurons in the neocortical layers V and III is discussed as the structural substrate for this network architecture. RFNNs self-organize spike trains and render the entire neural network output accessible to the dendritic tree of each neuron within this network. As the result of a contraction mapping operation, the local dendritic input pattern contains a downscaled version of the network output coding structure. RFNNs perform robust, fractal data compression, thus coping with a limited number of feedback loops for signal transport in convergent neural networks. This property is discussed as a significant step toward the solution of a fundamental problem in neuroscience: how is neuronal computation in separate neurons and remote brain areas unified as an instance of experience in consciousness? RFNNs are promising candidates for engaging neural networks into a coherent activity and provide a strategy for the exchange of global and local information processing in the human brain, thereby ensuring the completeness of a transformation from neuronal computation into conscious experience.

  16. Early secretory pathway localization and lack of processing for hepatitis E virus replication protein pORF1.

    PubMed

    Perttilä, Julia; Spuul, Pirjo; Ahola, Tero

    2013-04-01

    Hepatitis E virus (HEV) is a positive-strand RNA virus and a major causative agent of acute sporadic and epidemic hepatitis. HEV replication protein is encoded by ORF1 and contains the predicted domains of methyltransferase (MT), protease, macro domain, helicase (HEL) and polymerase (POL). In this study, the full-length protein pORF1 (1693 aa) and six truncated variants were expressed by in vitro translation and in human HeLa and hepatic Huh-7 cells by using several vector systems. The proteins were visualized by three specific antisera directed against the MT, HEL and POL domains. In vitro translation of full-length pORF1 yielded smaller quantities of two fragments. However, these fragments were not observed after pORF1 expression and pulse-chase studies in human cells, and their production was not dependent on the predicted protease domain in pORF1. The weight of evidence supports the proposition that pORF1 is not subjected to specific proteolytic processing, which is unusual among animal positive-strand RNA viruses but common for plant viruses. pORF1 was membrane associated in cells and localized to a perinuclear region, where it partially overlapped with localization of the endoplasmic reticulum (ER) marker BAP31 and was closely interspersed with staining of the ER-Golgi intermediate compartment marker protein ERGIC-53. Co-localization with BAP31 was enhanced by treatment with brefeldin A. Therefore, HEV may utilize modified early secretory pathway membranes for replication.

  17. Passive air sampler as a tool for long-term air pollution monitoring: Part 1. Performance assessment for seasonal and spatial variations.

    PubMed

    Klánová, Jana; Kohoutek, Jirí; Hamplová, Lenka; Urbanová, Petra; Holoubek, Ivan

    2006-11-01

    The potential of passive air sampling devices (polyurethane foam disks) to assess the influence of local sources on the quality of the surrounding environment was investigated. DEZA Valasske Mezirici, a coal tar and mixed tar oils processing plant, and Spolana Neratovice, a chemical factory with the history of high production of organochlorinated pesticides (OCPs), were selected as the point sources of PAHs, and OCPs, respectively. Levels of PCBs, OCPs and PAHs were determined for all sampling sites and sampling periods. The study brought useful data about the air concentrations of POPs in the investigated regions. More important, it provided information on the transport and fate of POPs in the vicinity of local sources of contamination useful for the estimation of their influence. Very good capability of passive samplers to reflect temporal and spatial fluctuation in concentrations of persistent organic pollutants in the ambient air was confirmed which makes them applicable for monitoring on the local scale.

  18. Development of a real-time lumbar ultrasound image processing system for epidural needle entry site localization.

    PubMed

    Yusong Leng; Shuang Yu; Kok Kiong Tan; Tildsley, Philip; Sia, Alex Tiong Heng; Ban Leong Sng

    2016-08-01

    A fully-automatic ultrasound image processing system that can determine the needle entry site for epidural anesthesia (EA) in real time is presented in this paper. Neither the knowledge of anesthetists nor additional hardware is required to operate the system, which firstly directs the anesthetists to reach the desired insertion region in the longitudinal view, i.e., lumbar level L3-L4, and then locates the ideal puncture site by instructing the anesthetists to rotate and slightly adjust the position of ultrasound probe. In order to implement these functions, modules including image processing, panorama stitching, feature extraction/selection, template matching and support vector machine (SVM) classification are incorporated in this system. Additionally, a user-friendly graphical user interface (GUI), which displays the processing results and guides anesthetists intuitively, is further designed to conceal the intricacy of algorithms. Feasibility and effectiveness of the proposed system has been evaluated through a set of realtime tests on 53 volunteers from a local hospital.

  19. Automating the design of image processing pipelines for novel color filter arrays: local, linear, learned (L3) method

    NASA Astrophysics Data System (ADS)

    Tian, Qiyuan; Lansel, Steven; Farrell, Joyce E.; Wandell, Brian A.

    2014-03-01

    The high density of pixels in modern color sensors provides an opportunity to experiment with new color filter array (CFA) designs. A significant bottleneck in evaluating new designs is the need to create demosaicking, denoising and color transform algorithms tuned for the CFA. To address this issue, we developed a method(local, linear, learned or L3) for automatically creating an image processing pipeline. In this paper we describe the L3 algorithm and illustrate how we created a pipeline for a CFA organized as a 2×2 RGB/Wblock containing a clear (W) pixel. Under low light conditions, the L3 pipeline developed for the RGB/W CFA produces images that are superior to those from a matched Bayer RGB sensor. We also use L3 to learn pipelines for other RGB/W CFAs with different spatial layouts. The L3 algorithm shortens the development time for producing a high quality image pipeline for novel CFA designs.

  20. Oxidative stress affects FET proteins localization and alternative pre-mRNA processing in cellular models of ALS.

    PubMed

    Svetoni, Francesca; Caporossi, Daniela; Paronetto, Maria Paola

    2014-10-01

    FUS/TLS, EWS and TAF15 are members of the FET family of DNA and RNA binding proteins, involved in multiple steps of DNA and RNA processing and implicated in the regulation of gene expression and cell-signaling. All members of the FET family contribute to human pathologies, as they are involved in sarcoma translocations and neurodegenerative diseases. Mutations in FUS/TLS, in EWSR1 and in TAF15 genescause Amyotrophic Lateral Sclerosis (ALS), a fatal human neurodegenerative disease that affects primarily motor neurons and is characterized by the progressive loss of motor neurons and degradation of the neuromuscular junctions.ALS-associated FET mutations cause FET protein relocalization into cytoplasmic aggregates, thus impairing their normal function. Protein aggregation has been suggested as a co-opting factor during the disease pathogenesis. Cytoplasmic mislocalization of FET proteins contributes to the formation of cytoplasmic aggregates that may alter RNA processing and initiate motor neuron degeneration. Interestingly, oxidative stress, which is implicated in the pathogenesis of ALS, triggers the accumulation of mutant FUS in cytoplasmic stress granules where it binds and sequester wild-type FUS.In order to evaluate the role of FET proteins in ALS and their involvement in the response to oxidative stress, we have developed cellular models of ALS expressing ALS-related FET mutants in neuroblastoma cell lines. Upon treatment with sodium arsenite, cells were analysed by immunofluorescence to monitor the localization of wild-type and mutated FET proteins. Furthermore, we have characterized signal transduction pathways and cell survival upon oxidative stress in our cellular models of ALS. Interestingly, we found that EWS mutant proteins display a different localization from FUS mutants and neither wild-type nor mutated EWS protein translocate into stress granules upon oxidative stress treatment. Collectively, our data provide a new link between the oxidative stress