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Sample records for polarimetric detection characterization

  1. Automated chromatographic system with polarimetric detection laser applied in the control of fermentation processes and seaweed extracts characterization

    International Nuclear Information System (INIS)

    Fajer, V.; Naranjo, S.; Mora, W.; Patinno, R.; Coba, E.; Michelena, G.

    2012-01-01

    There are presented applications and innovations of chromatographic and polarimetric systems in which develop methodologies for measuring the input molasses and the resulting product of a fermentation process of alcohol from a rich honey and evaluation of the fermentation process honey servery in obtaining a drink native to the Yucatan region. Composition was assessed optically active substances in seaweed, of interest to the pharmaceutical industry. The findings provide measurements alternative raw materials and products of the sugar industry, beekeeping and pharmaceutical liquid chromatography with automated polarimetric detection reduces measurement times up to 15 min, making it comparable to the times of high chromatography resolution, significantly reducing operating costs. By chromatography system with polarimetric detection (SCDP) is new columns have included standard size designed by the authors, which allow process samples with volumes up to 1 ml and reduce measurement time to 15 min, decreasing to 5 times the volume sample and halving the time of measurement. Was evaluated determining the concentration of substances using the peaks of the chromatograms obtained for the different columns and calculate the uncertainty of measurements. The results relating to the improvement of a data acquisition program (ADQUIPOL v.2.0) and new programs for the preparation of chromatograms (CROMAPOL CROMAPOL V.1.0 and V.1.2) provide important benefits, which allow a considerable saving of time the processing of the results and can be applied in other chromatography systems with the appropriate adjustments. (Author)

  2. Change detection in polarimetric SAR data over several time points

    DEFF Research Database (Denmark)

    Conradsen, Knut; Nielsen, Allan Aasbjerg; Skriver, Henning

    2014-01-01

    A test statistic for the equality of several variance-covariance matrices following the complex Wishart distribution is introduced. The test statistic is applied successfully to detect change in C-band EMISAR polarimetric SAR data over four time points.......A test statistic for the equality of several variance-covariance matrices following the complex Wishart distribution is introduced. The test statistic is applied successfully to detect change in C-band EMISAR polarimetric SAR data over four time points....

  3. Change Detection with Polarimetric SAR Imagery for Nuclear Verification

    International Nuclear Information System (INIS)

    Canty, M.

    2015-01-01

    This paper investigates the application of multivariate statistical change detection with high-resolution polarimetric SAR imagery acquired from commercial satellite platforms for observation and verification of nuclear activities. A prototype software tool comprising a processing chain starting from single look complex (SLC) multitemporal data through to change detection maps is presented. Multivariate change detection algorithms applied to polarimetric SAR data are not common. This is because, up until recently, not many researchers or practitioners have had access to polarimetric data. However with the advent of several spaceborne polarimetric SAR instruments such as the Japanese ALOS, the Canadian Radarsat-2, the German TerraSAR-X, the Italian COSMO-SkyMed missions and the European Sentinal SAR platform, the situation has greatly improved. There is now a rich source of weather-independent satellite radar data which can be exploited for Nuclear Safeguards purposes. The method will also work for univariate data, that is, it is also applicable to scalar or single polarimetric SAR data. The change detection procedure investigated here exploits the complex Wishart distribution of dual and quad polarimetric imagery in look-averaged covariance matrix format in order to define a per-pixel change/no-change hypothesis test. It includes approximations for the probability distribution of the test statistic, and so permits quantitative significance levels to be quoted for change pixels. The method has been demonstrated previously with polarimetric images from the airborne EMISAR sensor, but is applied here for the first time to satellite platforms. In addition, an improved multivariate method is used to estimate the so-called equivalent number of looks (ENL), which is a critical parameter of the hypothesis test. (author)

  4. Segment-based change detection for polarimetric SAR data

    DEFF Research Database (Denmark)

    Skriver, Henning; Nielsen, Allan Aasbjerg; Conradsen, Knut

    2006-01-01

    that is needed compared to single polarisation SAR to provide reliable and robust detection of changes. Polarimetric SAR data will be available from satellites in the near future, e.g. the Japanese ALOS, the Canadian Radarsat-2 and the German TerraSAR-X. An appropriate way of representing multi-look fully...... be split into a number of smaller fields, a building may be removed from or added to some area, hedgerows may be removed/added or other type of vegetated areas may be partly removed or added. In this case, ambiguities may arise when segments have changed shape and extent from one image to another...

  5. Change detection in a time series of polarimetric SAR images

    DEFF Research Database (Denmark)

    Skriver, Henning; Nielsen, Allan Aasbjerg; Conradsen, Knut

    A test statistic for the equality of two or several variance-covariance matrices following the real (as opposed to the complex) Wishart distribution with an associated probability of finding a smaller value of the test statistic is described in the literature [1]. In 2003 we introduced a test...... statistic for the equality of two variance-covariance matrices following the complex Wishart distribution with an associated probability measure [2]. In that paper we also demonstrated the use of the test statistic to change detection over time in both fully polarimetric and azimuthal symmetric SAR data...... positives (postulating a change when there actually is none) and/or false negatives (missing an actual change). Therefore we need to test for equality for all time points simultaneously. In this paper we demonstrate a new test statistic for the equality of several variance-covariance matrices from the real...

  6. Testing a polarimetric cloud imager aboard research vessel Polarstern: comparison of color-based and polarimetric cloud detection algorithms.

    Science.gov (United States)

    Barta, András; Horváth, Gábor; Horváth, Ákos; Egri, Ádám; Blahó, Miklós; Barta, Pál; Bumke, Karl; Macke, Andreas

    2015-02-10

    Cloud cover estimation is an important part of routine meteorological observations. Cloudiness measurements are used in climate model evaluation, nowcasting solar radiation, parameterizing the fluctuations of sea surface insolation, and building energy transfer models of the atmosphere. Currently, the most widespread ground-based method to measure cloudiness is based on analyzing the unpolarized intensity and color distribution of the sky obtained by digital cameras. As a new approach, we propose that cloud detection can be aided by the additional use of skylight polarization measured by 180° field-of-view imaging polarimetry. In the fall of 2010, we tested such a novel polarimetric cloud detector aboard the research vessel Polarstern during expedition ANT-XXVII/1. One of our goals was to test the durability of the measurement hardware under the extreme conditions of a trans-Atlantic cruise. Here, we describe the instrument and compare the results of several different cloud detection algorithms, some conventional and some newly developed. We also discuss the weaknesses of our design and its possible improvements. The comparison with cloud detection algorithms developed for traditional nonpolarimetric full-sky imagers allowed us to evaluate the added value of polarimetric quantities. We found that (1) neural-network-based algorithms perform the best among the investigated schemes and (2) global information (the mean and variance of intensity), nonoptical information (e.g., sun-view geometry), and polarimetric information (e.g., the degree of polarization) improve the accuracy of cloud detection, albeit slightly.

  7. Toward automated face detection in thermal and polarimetric thermal imagery

    Science.gov (United States)

    Gordon, Christopher; Acosta, Mark; Short, Nathan; Hu, Shuowen; Chan, Alex L.

    2016-05-01

    Visible spectrum face detection algorithms perform pretty reliably under controlled lighting conditions. However, variations in illumination and application of cosmetics can distort the features used by common face detectors, thereby degrade their detection performance. Thermal and polarimetric thermal facial imaging are relatively invariant to illumination and robust to the application of makeup, due to their measurement of emitted radiation instead of reflected light signals. The objective of this work is to evaluate a government off-the-shelf wavelet based naïve-Bayes face detection algorithm and a commercial off-the-shelf Viola-Jones cascade face detection algorithm on face imagery acquired in different spectral bands. New classifiers were trained using the Viola-Jones cascade object detection framework with preprocessed facial imagery. Preprocessing using Difference of Gaussians (DoG) filtering reduces the modality gap between facial signatures across the different spectral bands, thus enabling more correlated histogram of oriented gradients (HOG) features to be extracted from the preprocessed thermal and visible face images. Since the availability of training data is much more limited in the thermal spectrum than in the visible spectrum, it is not feasible to train a robust multi-modal face detector using thermal imagery alone. A large training dataset was constituted with DoG filtered visible and thermal imagery, which was subsequently used to generate a custom trained Viola-Jones detector. A 40% increase in face detection rate was achieved on a testing dataset, as compared to the performance of a pre-trained/baseline face detector. Insights gained in this research are valuable in the development of more robust multi-modal face detectors.

  8. Compact Polarimetric SAR Ship Detection with m-δ Decomposition Using Visual Attention Model

    Directory of Open Access Journals (Sweden)

    Lu Xu

    2016-09-01

    Full Text Available A few previous studies have illustrated the potentials of compact polarimetric Synthetic Aperture Radar (CP SAR in ship detection. In this paper, we design a ship detection algorithm of CP SAR from the perspective of computer vision. A ship detection algorithm using the pulsed cosine transform (PCT visual attention model is proposed to suppress background clutter and highlight conspicuous ship targets. It is the first time that a visual attention model is introduced to CP SAR application. The proposed algorithm is a quick and complete framework for practical use. Polarimetric features—the relative phase δ and volume scattering component—are extracted from m-δ decomposition to eliminate false alarms and modify the PCT model. The constant false alarm rate (CFAR algorithm based on lognormal distribution is adopted to detect ship targets, after a clutter distribution fitting procedure of the modified saliency map. The proposed method is then tested on three simulated circular-transmit-linear-receive (CTLR mode images, which covering East Sea of China. Compared with the detection results of SPAN and the saliency map with only single-channel amplitude, the proposed method achieves the highest detection rates and the lowest misidentification rate and highest figure of merit, proving the effectiveness of polarimetric information of compact polarimetric SAR ship detection and the enhancement from the visual attention model.

  9. Application of Deep Networks to Oil Spill Detection Using Polarimetric Synthetic Aperture Radar Images

    Directory of Open Access Journals (Sweden)

    Guandong Chen

    2017-09-01

    Full Text Available Polarimetric synthetic aperture radar (SAR remote sensing provides an outstanding tool in oil spill detection and classification, for its advantages in distinguishing mineral oil and biogenic lookalikes. Various features can be extracted from polarimetric SAR data. The large number and correlated nature of polarimetric SAR features make the selection and optimization of these features impact on the performance of oil spill classification algorithms. In this paper, deep learning algorithms such as the stacked autoencoder (SAE and deep belief network (DBN are applied to optimize the polarimetric feature sets and reduce the feature dimension through layer-wise unsupervised pre-training. An experiment was conducted on RADARSAT-2 quad-polarimetric SAR image acquired during the Norwegian oil-on-water exercise of 2011, in which verified mineral, emulsions, and biogenic slicks were analyzed. The results show that oil spill classification achieved by deep networks outperformed both support vector machine (SVM and traditional artificial neural networks (ANN with similar parameter settings, especially when the number of training data samples is limited.

  10. Biophysical Forest Type Characterization in the Colombian Amazon by Airborne Polarimetric SAR

    NARCIS (Netherlands)

    Hoekman, D.H.; Quiñones, M.J.

    2002-01-01

    Fully polarimetric C-, L-, and P-band data were collected by NASA's AirSAR system in May 1993 at the Araracuara test site, a well-surveyed forest reserve in the center of the Colombian Amazon. The area is characterized by a high diversity of forest types, soil types, and flooding conditions. In this

  11. Change detection in polarimetric SAR data and the complex Wishart distribution

    DEFF Research Database (Denmark)

    Conradsen, Knut; Nielsen, Allan Aasbjerg; Schou, Jesper

    2001-01-01

    . Based on this distribution a test statistic for equality of two such matrices and an associated asymptotic probability for obtaining a smaller value of the test statistic are given and applied to change detection in polarimetric SAR data. In a case study EMISAR L-band data from 17 April 1998 and 20 May...

  12. Polarimetric LIDAR with FRI sampling for target characterization

    Science.gov (United States)

    Wijerathna, Erandi; Creusere, Charles D.; Voelz, David; Castorena, Juan

    2017-09-01

    Polarimetric LIDAR is a significant tool for current remote sensing applications. In addition, measurement of the full waveform of the LIDAR echo provides improved ranging and target discrimination, although, data storage volume in this approach can be problematic. In the work presented here, we investigated the practical issues related to the implementation of a full waveform LIDAR system to identify polarization characteristics of multiple targets within the footprint of the illumination beam. This work was carried out on a laboratory LIDAR testbed that features a flexible arrangement of targets and the ability to change the target polarization characteristics. Targets with different retardance characteristics were illuminated with a linearly polarized laser beam and the return pulse intensities were analyzed by rotating a linear analyzer polarizer in front of a high-speed detector. Additionally, we explored the applicability and the limitations of applying a sparse sampling approach based on Finite Rate of Innovations (FRI) to compress and recover the characteristic parameters of the pulses reflected from the targets. The pulse parameter values extracted by the FRI analysis were accurate and we successfully distinguished the polarimetric characteristics and the range of multiple targets at different depths within the same beam footprint. We also demonstrated the recovery of an unknown target retardance value from the echoes by applying a Mueller matrix system model.

  13. Detection of buried pipes by polarimetric borehole radar; Polarimetric borehole radar ni yoru maisetsukan no kenshutsu jikken

    Energy Technology Data Exchange (ETDEWEB)

    Sato, M.; Niitsuma, H. [Tohoku University, Sendai (Japan); Nakauchi, T. [Osaka Gas Co. Ltd., Osaka (Japan)

    1997-05-27

    If the borehole radar is utilized for detection of buried pipes, the underground radar measurement becomes possible even in the situation where the mesurement on the earth surface is difficult, for example, such a place as under the road where there is much traffic. However, since buried pipes are horizontally installed and the existing borehole radar can send/receive only vertical polarization, the measurement conducted comes to be poor in efficiency from a viewpoint of the polarization utilization. Therefore, by introducing the polarimetric borehole radar to the detection of buried pipes, a basic experiment was conducted for the effective detection of horizontal buried pipes. Proposing the use of a slot antenna which can send/receive horizontal polarization in borehole in addition to a dipole antenna which sends/receives vertical polarization, developed was a step frequency type continuous wave radar of a network analyzer basis. As a result of the experiment, it was confirmed that reflection from buried pipes is largely dependent on polarization. Especially, it was found that in the slot dipole cross polarization mesurement, reflection from buried pipes can be emphasized. 4 refs., 5 figs.

  14. Spectral and polarimetric characterization of gazeous and telluric planets with SEE COAST

    Science.gov (United States)

    Boccaletti, A.; Baudoz, P.; Mawet, D.; Schneider, J.; Tinetti, G.; Galicher, R.; Stam, D.; Cavarroc, C.; Hough, J.; Doel, P.; Pinfield, D.; Keller, C.-U.; Beuzit, J.-L.; Udry, S.; Ferrari, A.; Martin, E.; Ménard, F.; Sein, E.

    2011-07-01

    SEE COAST stands for Super Earth Explorer - Coronagraphic Off-Axis Space Telescope. The concept was initially proposed to ESA for Cosmic Vision. None of the direct detection exoplanet proposals were selected in 2007 and we are now pursuing our efforts to consolidate the astrophysical program and the technical developments for the next call for proposal. The prime objective of SEE COAST is to contribute to the understanding of the formation and evolution of planetary systems. Exploring the diversity of these objects is therefore the main driver to define the instrumentation. In the next decade the improvement of radial velocity instruments and obviously temporal coverage will provide us with a large numbers of long period giants as well as telluric planets, namely Super Earths. Obtaining the spectral and polarimetric signatures of these objects in the visible range to measure atmospheric parameters (molecular composition, clouds, soils, …) will be unique and with important scientific returns. A space mission complementary to near IR instruments like SPHERE, GPI, JWST and later ELTs for the full characterization of giants and Super Earths is a first secure step towards the longer term goal that is the characterization of telluric planets with mass and atmosphere comparable to that of the Earth. An overview of the astrophysical motivation and the trade-off that lead to a simple integrated concept of a space-based high contrast imaging instrument are given here.

  15. Underwater Topography Detection in Coastal Areas Using Fully Polarimetric SAR Data

    Directory of Open Access Journals (Sweden)

    Xiaolin Bian

    2017-06-01

    Full Text Available Fully polarimetric synthetic aperture radar (SAR can provide detailed information on scattering mechanisms that could enable the target or structure to be identified. This paper presents a method to detect underwater topography in coastal areas using high resolution fully polarimetric SAR data, while less prior information is required. The method is based on the shoaling and refraction of long surface gravity waves as they propagate shoreward. First, the surface scattering component is obtained by polarization decomposition. Then, wave fields are retrieved from the two-dimensional (2D spectra by the Fast Fourier Transformation (FFT. Finally, shallow water depths are estimated from the dispersion relation. Applicability and effectiveness of the proposed methodology are tested by using C-band fine quad-polarization mode RADARSAT-2 SAR data over the near-shore area of the Hainan province, China. By comparing with the values from an official electronic navigational chart (ENC, the estimated water depths are in good agreement with them. The average relative error of the detected results from the scattering mechanisms based method and single polarization SAR data are 9.73% and 11.53% respectively. The validation results indicate that the scattering mechanisms based methodology is more effective than only using the single polarization SAR data for underwater topography detection, and will inspire further research on underwater topography detection with fully polarimetric SAR data.

  16. Polarimetric borehole radar measurement near Nojima fault and its application to subsurface crack characterization; Polarimetric borehole radar ni yoru Nojima danso shuhen no chika kiretsu keisoku jikken

    Energy Technology Data Exchange (ETDEWEB)

    Sato, M.; Taniguchi, Y.; Miwa, T.; Niitsuma, H. [Tohoku University, Sendai (Japan); Ikeda, R. [National Research Institute for Disaster Prevention, Tsukuba (Japan); Makino, K. [Geophysical Surveying and Consulting Co. Ltd., Tokyo (Japan)

    1997-05-27

    Practical application of subsurface crack characterization by the borehole radar measurement to which the radar polarimetric method was introduced was attempted to measuring objects for which the borehole radar has not been much used, for example, the inside of low loss rock mass or fracture zone where cracks tightly exist. A system was trially manufactured which makes the radar polarimetric measurement possible in the borehole at a 1000m depth and with a about 10cm diameter, and a field experiment was conducted for realizing the subsurface crack characterization near the Nojima fault. For the measuring experiment by the polarimetric borehole radar, used were Iwaya borehole and Hirabayashi borehole drilled in the north of Awaji-shima, Hyogo-ken. In a comparison of both polarization systems of Hirabayashi borehole, reflected waves at depths of 1038m and 1047m are relatively stronger in both polarization systems than those with the same polarization form and at different depths, whereas reflected waves around a 1017m depth are strong only as to the parallel polarization system. Characteristics of the polarization in this experiment indirectly reflect crack structures. 6 refs., 6 figs., 1 tab.

  17. Landslide Mapping in Vegetated Areas Using Change Detection Based on Optical and Polarimetric SAR Data

    Directory of Open Access Journals (Sweden)

    Simon Plank

    2016-04-01

    Full Text Available Mapping of landslides, quickly providing information about the extent of the affected area and type and grade of damage, is crucial to enable fast crisis response, i.e., to support rescue and humanitarian operations. Most synthetic aperture radar (SAR data-based landslide detection approaches reported in the literature use change detection techniques, requiring very high resolution (VHR SAR imagery acquired shortly before the landslide event, which is commonly not available. Modern VHR SAR missions, e.g., Radarsat-2, TerraSAR-X, or COSMO-SkyMed, do not systematically cover the entire world, due to limitations in onboard disk space and downlink transmission rates. Here, we present a fast and transferable procedure for mapping of landslides, based on change detection between pre-event optical imagery and the polarimetric entropy derived from post-event VHR polarimetric SAR data. Pre-event information is derived from high resolution optical imagery of Landsat-8 or Sentinel-2, which are freely available and systematically acquired over the entire Earth’s landmass. The landslide mapping is refined by slope information from a digital elevation model generated from bi-static TanDEM-X imagery. The methodology was successfully applied to two landslide events of different characteristics: A rotational slide near Charleston, West Virginia, USA and a mining waste earthflow near Bolshaya Talda, Russia.

  18. BUILT-UP AREA DETECTION BASED ON SUBSPACE PROJECTIONS USING POLARIMETRIC SAR DATA

    Directory of Open Access Journals (Sweden)

    R. Bordbari

    2017-09-01

    Full Text Available The task of detecting and identifying objects remotely has long been an area of intense interest and active research. Active sensing of objects with radio waves is a whole new domain of target detection which is made available by radar remote sensors. Land cover/use information extraction is one of the most important applications of radar remote sensing, especially in urban areas. In this paper, we take a new look at the built-up area extraction problem in polarimetric SAR (PolSAR data and assume canonical scattering mechanisms as our signal sources which combination of them with appropriate weight fractions formed a scattering vector of each pixel. The set of the scattering mechanisms is divided into two groups: the scattering mechanism of built-up area, and non-objected scattering mechanisms. Then, we describe a technique which simultaneously annihilates the effect of non-objected scattering mechanisms, and detects the presence of a scattering mechanism of interest. The experimental results on several quad-polarimetric datasets show the significant agreement with expected results, while saving computational complexity.

  19. POLARIMETRIC DETECTION OF EXOPLANETS TRANSITING T AND L BROWN DWARFS

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, Sujan, E-mail: sujan@iiap.res.in [Indian Institute of Astrophysics, Koramangala 2nd Block, Bangalore 560 034 (India)

    2016-10-01

    While scattering of light by atoms and molecules yields large amounts of polarization at the B-band of both T and L dwarfs, scattering by dust grains in the cloudy atmosphere of L dwarfs gives rise to significant polarization at the far-optical and infrared wavelengths where these objects are much brighter. However, the observable disk-averaged polarization should be zero if the clouds are uniformly distributed and the object is spherically symmetric. Therefore, in order to explain the observed large polarization of several L dwarfs, rotation-induced oblateness or horizontally inhomogeneous cloud distribution in the atmosphere is invoked. On the other hand, when an extra-solar planet of Earth-size or larger transits the brown dwarf along the line of sight, the asymmetry induced during the transit gives rise to a net non-zero, time-dependent polarization. Employing atmospheric models for a range of effective temperature and surface gravity appropriate for T and L dwarfs, I derive the time-dependent polarization profiles of these objects during the transit phase and estimate the peak amplitude of polarization that occurs during the inner contact points of the transit ingress/egress phase. It is found that peak polarization in the range of 0.2%–1.0% at I and J band may arise of cloudy L dwarfs occulted by Earth-size or larger exoplanets. Such an amount of polarization is higher than what can be produced by rotation-induced oblateness of even rapidly rotating L dwarfs. Hence, I suggest that time-resolved imaging polarization could be a potential technique for detecting transiting exoplanets around L dwarfs.

  20. POLARIMETRIC DETECTION OF EXOPLANETS TRANSITING T AND L BROWN DWARFS

    International Nuclear Information System (INIS)

    Sengupta, Sujan

    2016-01-01

    While scattering of light by atoms and molecules yields large amounts of polarization at the B-band of both T and L dwarfs, scattering by dust grains in the cloudy atmosphere of L dwarfs gives rise to significant polarization at the far-optical and infrared wavelengths where these objects are much brighter. However, the observable disk-averaged polarization should be zero if the clouds are uniformly distributed and the object is spherically symmetric. Therefore, in order to explain the observed large polarization of several L dwarfs, rotation-induced oblateness or horizontally inhomogeneous cloud distribution in the atmosphere is invoked. On the other hand, when an extra-solar planet of Earth-size or larger transits the brown dwarf along the line of sight, the asymmetry induced during the transit gives rise to a net non-zero, time-dependent polarization. Employing atmospheric models for a range of effective temperature and surface gravity appropriate for T and L dwarfs, I derive the time-dependent polarization profiles of these objects during the transit phase and estimate the peak amplitude of polarization that occurs during the inner contact points of the transit ingress/egress phase. It is found that peak polarization in the range of 0.2%–1.0% at I and J band may arise of cloudy L dwarfs occulted by Earth-size or larger exoplanets. Such an amount of polarization is higher than what can be produced by rotation-induced oblateness of even rapidly rotating L dwarfs. Hence, I suggest that time-resolved imaging polarization could be a potential technique for detecting transiting exoplanets around L dwarfs.

  1. A test statistic in the complex Wishart distribution and its application to change detection in polarimetric SAR data

    DEFF Research Database (Denmark)

    Conradsen, Knut; Nielsen, Allan Aasbjerg; Schou, Jesper

    2003-01-01

    . Based on this distribution, a test statistic for equality of two such matrices and an associated asymptotic probability for obtaining a smaller value of the test statistic are derived and applied successfully to change detection in polarimetric SAR data. In a case study, EMISAR L-band data from April 17...... to HH, VV, or HV data alone, the derived test statistic reduces to the well-known gamma likelihood-ratio test statistic. The derived test statistic and the associated significance value can be applied as a line or edge detector in fully polarimetric SAR data also....

  2. Comparison of vehicle-mounted forward-looking polarimetric infrared and downward-looking infrared sensors for landmine detection

    NARCIS (Netherlands)

    Cremer, F.; Schavemaker, J.G.M.; Jong, W. de; Schutte, K.

    2003-01-01

    This paper gives a comparison of two vehicle-mounted infrared systems for landmine detection. The first system is a down-ward looking standard infrared camera using processing methods developed within the EU project LOTUS. The second system is using a forward-looking polarimetric infrared camera.

  3. Detectability Analysis of Road Vehicles in Radarsat-2 Fully Polarimetric SAR Images for Traffic Monitoring

    Directory of Open Access Journals (Sweden)

    Bo Zhang

    2017-02-01

    Full Text Available By acquiring information over a wide area regardless of weather conditions and solar illumination, space-borne Synthetic Aperture Radar (SAR has the potential to be a promising application for traffic monitoring. However, the backscatter character of a vehicle in a SAR image is unstable and varies with image parameters, such as aspect and incidence angle. To investigate vehicle detectability in SAR images for traffic monitoring applications, images of four common types of vehicles in China were acquired using the fully polarimetric (FP SAR of Radarsat-2 in our experiments. Methods for measuring a vehicle’s aspect angle and backscatter intensity are introduced. The experimental FP SAR images are used to analyze the detectability, which is affected by factors such as vehicle size, vehicle shape, and aspect angle. Moreover, a new metric to improve vehicle detectability in FP SAR images is proposed and compared with the well-known intensity metric. The experimental results show that shape is a crucial factor in affecting the backscatter intensity of vehicles, which also oscillates with varying aspect angle. If the size of a vehicle is smaller than the SAR image resolution, using the intensity metric would result in low detectability. However, it could be improved in an FP SAR image by using the proposed metric. Compared with the intensity metric, the overall detectability is improved from 72% to 90% in our experiments. Therefore, this study indicates that FP SAR images have the ability to detect stationary vehicles on the road and are meaningful for traffic monitoring.

  4. Detecting Emergence, Growth, and Senescence of Wetland Vegetation with Polarimetric Synthetic Aperture Radar (SAR Data

    Directory of Open Access Journals (Sweden)

    Alisa L. Gallant

    2014-03-01

    Full Text Available Wetlands provide ecosystem goods and services vitally important to humans. Land managers and policymakers working to conserve wetlands require regularly updated information on the statuses of wetlands across the landscape. However, wetlands are challenging to map remotely with high accuracy and consistency. We investigated the use of multitemporal polarimetric synthetic aperture radar (SAR data acquired with Canada’s Radarsat-2 system to track within-season changes in wetland vegetation and surface water. We speculated, a priori, how temporal and morphological traits of different types of wetland vegetation should respond over a growing season with respect to four energy-scattering mechanisms. We used ground-based monitoring data and other ancillary information to assess the limits and consistency of the SAR data for tracking seasonal changes in wetlands. We found the traits of different types of vertical emergent wetland vegetation were detected well with the SAR data and corresponded with our anticipated backscatter responses. We also found using data from Landsat’s optical/infrared sensors in conjunction with SAR data helped remove confusion of wetland features with upland grasslands. These results suggest SAR data can provide useful monitoring information on the statuses of wetlands over time.

  5. Detecting emergence, growth, and senescence of wetland vegetation with polarimetric synthetic aperture radar (SAR) data

    Science.gov (United States)

    Gallant, Alisa L.; Kaya, Shannon G.; White, Lori; Brisco, Brian; Roth, Mark F.; Sadinski, Walter J.; Rover, Jennifer

    2014-01-01

    Wetlands provide ecosystem goods and services vitally important to humans. Land managers and policymakers working to conserve wetlands require regularly updated information on the statuses of wetlands across the landscape. However, wetlands are challenging to map remotely with high accuracy and consistency. We investigated the use of multitemporal polarimetric synthetic aperture radar (SAR) data acquired with Canada’s Radarsat-2 system to track within-season changes in wetland vegetation and surface water. We speculated, a priori, how temporal and morphological traits of different types of wetland vegetation should respond over a growing season with respect to four energy-scattering mechanisms. We used ground-based monitoring data and other ancillary information to assess the limits and consistency of the SAR data for tracking seasonal changes in wetlands. We found the traits of different types of vertical emergent wetland vegetation were detected well with the SAR data and corresponded with our anticipated backscatter responses. We also found using data from Landsat’s optical/infrared sensors in conjunction with SAR data helped remove confusion of wetland features with upland grasslands. These results suggest SAR data can provide useful monitoring information on the statuses of wetlands over time.

  6. Pyxis handheld polarimetric imager

    Science.gov (United States)

    Chenault, David B.; Pezzaniti, J. Larry; Vaden, Justin P.

    2016-05-01

    The instrumentation for measuring infrared polarization signatures has seen significant advancement over the last decade. Previous work has shown the value of polarimetric imagery for a variety of target detection scenarios including detection of manmade targets in clutter and detection of ground and maritime targets while recent work has shown improvements in contrast for aircraft detection and biometric markers. These data collection activities have generally used laboratory or prototype systems with limitations on the allowable amount of target motion or the sensor platform and usually require an attached computer for data acquisition and processing. Still, performance and sensitivity have been steadily getting better while size, weight, and power requirements have been getting smaller enabling polarimetric imaging for a greater or real world applications. In this paper, we describe Pyxis®, a microbolometer based imaging polarimeter that produces live polarimetric video of conventional, polarimetric, and fused image products. A polarization microgrid array integrated in the optical system captures all polarization states simultaneously and makes the system immune to motion artifacts of either the sensor or the scene. The system is battery operated, rugged, and weighs about a quarter pound, and can be helmet mounted or handheld. On board processing of polarization and fused image products enable the operator to see polarimetric signatures in real time. Both analog and digital outputs are possible with sensor control available through a tablet interface. A top level description of Pyxis® is given followed by performance characteristics and representative data.

  7. Forest Structure Characterization Using Jpl's UAVSAR Multi-Baseline Polarimetric SAR Interferometry and Tomography

    Science.gov (United States)

    Neumann, Maxim; Hensley, Scott; Lavalle, Marco; Ahmed, Razi

    2013-01-01

    This paper concerns forest remote sensing using JPL's multi-baseline polarimetric interferometric UAVSAR data. It presents exemplary results and analyzes the possibilities and limitations of using SAR Tomography and Polarimetric SAR Interferometry (PolInSAR) techniques for the estimation of forest structure. Performance and error indicators for the applicability and reliability of the used multi-baseline (MB) multi-temporal (MT) PolInSAR random volume over ground (RVoG) model are discussed. Experimental results are presented based on JPL's L-band repeat-pass polarimetric interferometric UAVSAR data over temperate and tropical forest biomes in the Harvard Forest, Massachusetts, and in the La Amistad Park, Panama and Costa Rica. The results are partially compared with ground field measurements and with air-borne LVIS lidar data.

  8. Visualization of and Software for Omnibus Test Based Change Detected in a Time Series of Polarimetric SAR Data

    DEFF Research Database (Denmark)

    Nielsen, Allan Aasbjerg; Conradsen, Knut; Skriver, Henning

    2017-01-01

    Based on an omnibus likelihood ratio test statistic for the equality of several variance-covariance matrices following the complex Wishart distribution and a factorization of this test statistic with associated p-values, change analysis in a time series of multilook polarimetric SAR data...... in the covariance matrix representation is carried out. The omnibus test statistic and its factorization detect if and when change occurs. Using airborne EMISAR and spaceborne RADARSAT-2 data this paper focuses on change detection based on the p-values, on visualization of change at pixel as well as segment level......, and on computer software....

  9. Change detection in a time series of polarimetric SAR data by an omnibus test statistic and its factorization (Conference Presentation)

    Science.gov (United States)

    Nielsen, Allan A.; Conradsen, Knut; Skriver, Henning

    2016-10-01

    Test statistics for comparison of real (as opposed to complex) variance-covariance matrices exist in the statistics literature [1]. In earlier publications we have described a test statistic for the equality of two variance-covariance matrices following the complex Wishart distribution with an associated p-value [2]. We showed their application to bitemporal change detection and to edge detection [3] in multilook, polarimetric synthetic aperture radar (SAR) data in the covariance matrix representation [4]. The test statistic and the associated p-value is described in [5] also. In [6] we focussed on the block-diagonal case, we elaborated on some computer implementation issues, and we gave examples on the application to change detection in both full and dual polarization bitemporal, bifrequency, multilook SAR data. In [7] we described an omnibus test statistic Q for the equality of k variance-covariance matrices following the complex Wishart distribution. We also described a factorization of Q = R2 R3 … Rk where Q and Rj determine if and when a difference occurs. Additionally, we gave p-values for Q and Rj. Finally, we demonstrated the use of Q and Rj and the p-values to change detection in truly multitemporal, full polarization SAR data. Here we illustrate the methods by means of airborne L-band SAR data (EMISAR) [8,9]. The methods may be applied to other polarimetric SAR data also such as data from Sentinel-1, COSMO-SkyMed, TerraSAR-X, ALOS, and RadarSat-2 and also to single-pol data. The account given here closely follows that given our recent IEEE TGRS paper [7]. Selected References [1] Anderson, T. W., An Introduction to Multivariate Statistical Analysis, John Wiley, New York, third ed. (2003). [2] Conradsen, K., Nielsen, A. A., Schou, J., and Skriver, H., "A test statistic in the complex Wishart distribution and its application to change detection in polarimetric SAR data," IEEE Transactions on Geoscience and Remote Sensing 41(1): 4-19, 2003. [3] Schou, J

  10. Polarimetric Edge Detector Based on the Complex Wishart Distribution

    DEFF Research Database (Denmark)

    Skriver, Henning; Schou, Jesper; Nielsen, Allan Aasbjerg

    2001-01-01

    polarimetric edge detector provides a constant false alarm rate and it utilizes the full polarimetric information. The edge detector has been applied to polarimetric SAR data from the Danish dual-frequency, airborne polarimetric SAR, EMISAR. The results show clearly an improved edge detection performance...

  11. DARK SPOT DETECTION USING INTENSITY AND THE DEGREE OF POLARIZATION IN FULLY POLARIMETRIC SAR IMAGES FOR OIL POLUTION MONITORING

    Directory of Open Access Journals (Sweden)

    F. Zakeri

    2015-12-01

    Full Text Available Oil spill surveillance is of great environmental and economical interest, directly contributing to improve environmental protection. Monitoring of oil spills using synthetic aperture radar (SAR has received a considerable attention over the past few years, notably because of SAR data abilities like all-weather and day-and-night capturing. The degree of polarization (DoP is a less computationally complex quantity characterizing a partially polarized electromagnetic field. The key to the proposed approach is making use of DoP as polarimetric information besides intensity ones to improve dark patches detection as the first step of oil spill monitoring. In the proposed approach first simple intensity threshold segmentation like Otsu method is applied to the image. Pixels with intensities below the threshold are regarded as potential dark spot pixels while the others are potential background pixels. Second, the DoP of potential dark spot pixels is estimated. Pixels with DoP below a certain threshold are the real dark-spot pixels. Choosing the threshold is a critical and challenging step. In order to solve choosing the appropriate threshold, we introduce a novel but simple method based on DoP of potential dark spot pixels. Finally, an area threshold is used to eliminate any remaining false targets. The proposed approach is tested on L band NASA/JPL UAVSAR data, covering the Deepwater Horizon oil spill in the Gulf of Mexico. Comparing the obtained results from the new method with conventional approaches like Otsu, K-means and GrowCut shows better achievement of the proposed algorithm. For instance, mean square error (MSE 65%, Overall Accuracy 20% and correlation 40% are improved.

  12. Dark SPOT Detection Using Intensity and the Degree of Polarization in Fully Polarimetric SAR Images for Oil Polution Monitoring

    Science.gov (United States)

    Zakeri, F.; Amini, J.

    2015-12-01

    Oil spill surveillance is of great environmental and economical interest, directly contributing to improve environmental protection. Monitoring of oil spills using synthetic aperture radar (SAR) has received a considerable attention over the past few years, notably because of SAR data abilities like all-weather and day-and-night capturing. The degree of polarization (DoP) is a less computationally complex quantity characterizing a partially polarized electromagnetic field. The key to the proposed approach is making use of DoP as polarimetric information besides intensity ones to improve dark patches detection as the first step of oil spill monitoring. In the proposed approach first simple intensity threshold segmentation like Otsu method is applied to the image. Pixels with intensities below the threshold are regarded as potential dark spot pixels while the others are potential background pixels. Second, the DoP of potential dark spot pixels is estimated. Pixels with DoP below a certain threshold are the real dark-spot pixels. Choosing the threshold is a critical and challenging step. In order to solve choosing the appropriate threshold, we introduce a novel but simple method based on DoP of potential dark spot pixels. Finally, an area threshold is used to eliminate any remaining false targets. The proposed approach is tested on L band NASA/JPL UAVSAR data, covering the Deepwater Horizon oil spill in the Gulf of Mexico. Comparing the obtained results from the new method with conventional approaches like Otsu, K-means and GrowCut shows better achievement of the proposed algorithm. For instance, mean square error (MSE) 65%, Overall Accuracy 20% and correlation 40% are improved.

  13. An omnibus likelihood test statistic and its factorization for change detection in time series of polarimetric SAR data

    DEFF Research Database (Denmark)

    Nielsen, Allan Aasbjerg; Conradsen, Knut; Skriver, Henning

    2016-01-01

    Based on an omnibus likelihood ratio test statistic for the equality of several variance-covariance matrices following the complex Wishart distribution with an associated p-value and a factorization of this test statistic, change analysis in a short sequence of multilook, polarimetric SAR data...... in the covariance matrix representation is carried out. The omnibus test statistic and its factorization detect if and when change(s) occur. The technique is demonstrated on airborne EMISAR L-band data but may be applied to Sentinel-1, Cosmo-SkyMed, TerraSAR-X, ALOS and RadarSat-2 or other dual- and quad...

  14. Change detection in a time series of polarimetric SAR data by an omnibus test statistic and its factorization

    DEFF Research Database (Denmark)

    Nielsen, Allan Aasbjerg; Conradsen, Knut; Skriver, Henning

    2016-01-01

    Based on an omnibus likelihood ratio test statistic for the equality of several variance-covariance matrices following the complex Wishart distribution with an associated p-value and a factorization of this test statistic, change analysis in a short sequence of multilook, polarimetric SAR data...... in the covariance matrix representation is carried out. The omnibus test statistic and its factorization detect if and when change(s) occur. The technique is demonstrated on airborne EMISAR L-band data but may be applied to Sentinel-1, Cosmo-SkyMed, TerraSAR-X, ALOS and RadarSat-2 or other dual- and quad...

  15. Levee Seepage Detection in the Sacramento-San Joaquin Delta Using Polarimetric SAR

    Science.gov (United States)

    An, K.; Jones, C. E.; Bekaert, D. P.

    2017-12-01

    The Sacramento-San Joaquin Delta's extensive levee system protects over 2,800 km2 of reclaimed lands and serves as the main irrigation and domestic water supply for the state of California. However, ongoing subsidence and disaster threats from floods and earthquakes make the Delta levee system highly vulnerable, endangering water supplies for 23 million California residents and 2.5 million acres of agricultural land. Levee failure in the Delta can cause saltwater intrusion from San Francisco Bay, reducing water quality and curtailing water exports to residents, commercial users, and farmers. To protect the Delta levee system, it is essential to search for signs of seepage in which water is piping through or beneath levees, which can be associated with deformation of the levees themselves. Until now, in-situ monitoring has largely been applied, however, this is a time-consuming and expensive approach. We use data acquired with NASA's UAVSAR (Uninhabited Aerial Vehicle Synthetic Aperture Radar) airborne radar instrument to identify and characterize levee seepages and associated land subsidence through advanced remote sensing technologies. The high spatial resolution of UAVSAR can help to direct surveys to areas that are likely to be experiencing damage. UAVSAR is an L-band airborne sensor with high signal-to-noise ratio, repeat flight track accuracy, and spatial resolution of 7x7 m2 (for multi-looked products) that is necessary for detailed levee monitoring. The adaptability of radar instruments in their ability to see through smoke, haze, and clouds during the day or night, is especially relevant during disaster events, when cloud cover or lack of solar illumination inhibits traditional visual surveys of damage. We demonstrate the advantages of combining polarimetric radar imagery with geographic information systems (GIS) datasets in locating seepage features along critical levee infrastructure in the Delta for 2009-2016. The ability to efficiently locate potential

  16. AN UNSUPERVISED CHANGE DETECTION BASED ON TEST STATISTIC AND KI FROM MULTI-TEMPORAL AND FULL POLARIMETRIC SAR IMAGES

    Directory of Open Access Journals (Sweden)

    J. Q. Zhao

    2016-06-01

    Full Text Available Accurate and timely change detection of Earth’s surface features is extremely important for understanding relationships and interactions between people and natural phenomena. Many traditional methods of change detection only use a part of polarization information and the supervised threshold selection. Those methods are insufficiency and time-costing. In this paper, we present a novel unsupervised change-detection method based on quad-polarimetric SAR data and automatic threshold selection to solve the problem of change detection. First, speckle noise is removed for the two registered SAR images. Second, the similarity measure is calculated by the test statistic, and automatic threshold selection of KI is introduced to obtain the change map. The efficiency of the proposed method is demonstrated by the quad-pol SAR images acquired by Radarsat-2 over Wuhan of China.

  17. SPICES: Spectro-Polarimetric Imaging and Characterization of Exoplanetary Systems - From Planetary Disks To Nearby Super Earths

    Science.gov (United States)

    Boccaletti, Anthony; Schneider, Jean; Traub, Wes; Lagage, Pierre-Olivier; Stam, Daphne; Gratton, Raffaele; Trauger, John; Cahoy, Kerri; Snik, Frans; Baudoz, Pierre; hide

    2012-01-01

    SPICES (Spectro-Polarimetric Imaging and Characterization of Exoplanetary Systems) is a five-year M-class mission proposed to ESA Cosmic Vision. Its purpose is to image and characterize long-period extrasolar planets and circumstellar disks in the visible (450-900 nm) at a spectral resolution of about 40 using both spectroscopy and polarimetry. By 2020/2022, present and near-term instruments will have found several tens of planets that SPICES will be able to observe and study in detail. Equipped with a 1.5 m telescope, SPICES can preferentially access exoplanets located at several AUs (0.5-10 AU) from nearby stars (less than 25 pc) with masses ranging from a few Jupiter masses to Super Earths (approximately 2 Earth radii, approximately 10 mass compared to Earth) as well as circumstellar disks as faint as a few times the zodiacal light in the Solar System.

  18. Polarimetric mountain based radio-occultation for rain detection: The ROHP-PAZ ground campaign

    Science.gov (United States)

    Padulles, Ramon; Cardellach, Estel; Tomas, Sergio; de la Torre, Manuel; Turk, Joe

    2014-05-01

    The Radio Occultation and Heavy Precipitation experiment aboard the PAZ Low Earth Orbiter (ROHP-PAZ) is a mission of opportunity: The Spanish Ministry of Science and Innovation (MICINN) approved in 2009 a proposal to include a polarimetric Global Navigation Satellite System (GNSS) Radio-Occultation (RO) payload on board of the Spanish Earth Observation satellite PAZ. This will be a new technique that has never been tested before, that aims to improve the knowledge of precipitation through simultaneous thermodynamic and vertical rain profiles. Prior to the launch of the satellite, expected for 2014, a ground experimental campaign is being conducted with the goal of starting the process of identifying and understanding all the factors that might affect the polarimetric RO observables. The campaign is being carried out at the top of Puig Sesolles, a 1667m peak in the Natural Park of Montseny (41º46'24 N, 2º26'17 E), 50 km N-NE from Barcelona, with clear views over the horizon to the South (East to West) direction, an area in which intense precipitation events tend to occur a few times per year. The campaign uses a ICE-CSIC/IEEC's GOLD-RTR open-loop receiver initially designed for collecting GNSS signals reflected off the sea surface. The receiver has been adjusted to track occulting GNSS radio-links. A double polarization (H and V) GNSS antenna has been designed and manufactured by the Polytechnic University of Barcelona (UPC) team for this particular ground-based experiment. The antenna is a phase-array made of 7 elements, each of them being a square patch built using a Rogers 4003 substrate, and symmetrically fed by four probes. It provides a pattern of 12.9 dB peak gain, 45 degrees half-power beam-width, and <-35 dB cross-polar isolation at the peak (better than -30 dB in the main lobe). The preliminary results show that not only precipitation, but also other factors are affecting the GNSS signal, wich means that the polarimetric signal is richer than expected

  19. Ex vivo photometric and polarimetric multilayer characterization of human healthy colon by multispectral Mueller imaging.

    Science.gov (United States)

    Pierangelo, Angelo; Manhas, Sandeep; Benali, Abdelali; Fallet, Clément; Antonelli, Maria-Rosaria; Novikova, Tatiana; Gayet, Brice; Validire, Pierre; De Martino, Antonello

    2012-06-01

    Healthy human colon samples were analyzed ex vivo with a multispectral imaging Mueller polarimeter operating from 500 to 700 nm in a backscattering configuration with diffuse light illumination impinging on the innermost tissue layer, the mucosa. The intensity and polarimetric responses were taken on whole tissues first and after progressive exfoliation of the outer layers afterwards. Moreover, these measurements were carried out with two different substrates (one bright and the other dark) successively placed beneath each sample, allowing a reasonably accurate evaluation of the contributions to the overall backscattered light by the various layers. For the shorter investigated wavelengths (500 to 550 nm) the major contribution comes from mucosa and submucosa, while for the longer wavelengths (650 to 700 nm) muscular tissue and fat also contribute significantly. The depolarization has also been studied and is found to be stronger in the red part of the spectrum, mainly due to the highly depolarizing power of the muscular and fat layers.

  20. The use of Polarimetric EMISAR for the Mapping and Characterization of the Semi-Natural Environment

    DEFF Research Database (Denmark)

    Sørensen, Stefán Meulengracht

    Methods for segmentation and restoration of SAR data using Markov Random Fields (MRF) have been studied extensively by many researchers over the last two decades. What is of special interest is not only methods for segmentation and classification of SAR data for land cover labeling applications......-natural environments under study are very small, it is crucial for this investigation that the restoration methods are capable of restoring fine structures as well as preserving homogeneous areas. The restorations are carried out in a signal adaptive mode using MRF in a Bayesian framework. Different a priori models...... on statistics derived from the ratio images is presented together with comparative analyses of restorations using ICM and SA. The relation between the restored polarimetric SAR data and in situ data collected at two semi-natural wetland and grassland areas is investigated using multivariate techniques...

  1. Change detection in a short time sequence of polarimetric C-band SAR data

    DEFF Research Database (Denmark)

    Nielsen, Allan Aasbjerg; Conradsen, Knut; Skriver, Henning

    2016-01-01

    in the covariance matrix representation is carried out. The omnibus test statistic and its factorization detect if and when change(s) occur. The technique is demonstrated on airborne EMISAR C-band data but may be applied to ALOS, COSMO-SkyMed, RadarSat-2 Sentinel-1, TerraSAR-X, and Yaogan data also....

  2. Omnibus test for change detection in a time sequence of polarimetric SAR data

    DEFF Research Database (Denmark)

    Nielsen, Allan Aasbjerg; Conradsen, Knut; Skriver, Henning

    2016-01-01

    in the covariance matrix representation is carried out. The omnibus test statistic and its factorization detect if and when change(s) occur. The technique is demonstrated on airborne EMISAR C-band data but may be applied to ALOS, COSMO-SkyMed, RadarSat-2, Sentinel-1, TerraSAR-X, and Yoagan or other dual- and quad...

  3. Change detection in polarimetric SAR images using complex Wishart distributed matrices

    DEFF Research Database (Denmark)

    Conradsen, Knut; Nielsen, Allan Aasbjerg; Skriver, Henning

    In surveillance it is important to be able to detect natural or man-made changes e.g. based on sequences of satellite or air borne images of the same area taken at different times. The mapping capability of synthetic aperture radar (SAR) is independent of e.g. cloud cover, and thus this technology...... scattering matrix, and after suitable preprocessing the outcome at each picture element (pixel) may be represented as a 3 by 3 Hermitian matrix following a complex Wishart distribution. One approach to solving the change detection problem based on SAR images is therefore to apply suitable statistical tests...... in the complex Wishart distribution. We propose a set-up for a systematic solution to the (practical) problems using the likelihood ratio test statistics. We show some examples based on a time series of images with 1024 by 1024 pixels....

  4. Passive Polarimetric Information Processing for Target Classification

    Science.gov (United States)

    Sadjadi, Firooz; Sadjadi, Farzad

    Polarimetric sensing is an area of active research in a variety of applications. In particular, the use of polarization diversity has been shown to improve performance in automatic target detection and recognition. Within the diverse scope of polarimetric sensing, the field of passive polarimetric sensing is of particular interest. This chapter presents several new methods for gathering in formation using such passive techniques. One method extracts three-dimensional (3D) information and surface properties using one or more sensors. Another method extracts scene-specific algebraic expressions that remain unchanged under polariza tion transformations (such as along the transmission path to the sensor).

  5. Polarimetric Detection of Enantioselective Adsorption by Chiral Au Nanoparticles – Effects of Temperature, Wavelength and Size

    Directory of Open Access Journals (Sweden)

    Nisha Shukla

    2015-01-01

    Full Text Available R- and S-propylene oxide (PO have been shown to interact enantiospecifically with the chiral surfaces of Au nanopar‐ ticles (NPs modified with D- or L-cysteine (cys. This enantiospecific interaction has been detected using optical polarimetry measurements made on solutions of the D- or L-cys modified Au (cys/Au NPs during addition of racemic PO. The selective adsorption of one enantiomer of the PO onto the cys/Au NP surfaces results in a net rotation of light during addition of the racemic PO to the solution. In order to optimize the conditions used for making these measurements and to quantify enantiospecific adsorption onto chiral NPs, this work has measured the effect of temperature, wavelength and Au NP size on optical rotation by solutions containing D- or L-cys/Au NPs and racemic PO. Increasing temperature, decreasing wave‐ length and decreasing NP size result in larger optical rotations.

  6. Detection and Characterization of Hedgerows Using TerraSAR-X Imagery

    Directory of Open Access Journals (Sweden)

    Julie Betbeder

    2014-04-01

    Full Text Available Whilst most hedgerow functions depend upon hedgerow structure and hedgerow network patterns, in many ecological studies information on the fragmentation of hedgerows network and canopy structure is often retrieved in the field in small areas using accurate ground surveys and estimated over landscapes in a semi-quantitative manner. This paper explores the use of radar SAR imagery to (i detect hedgerow networks; and (ii describe the hedgerow canopy heterogeneity using TerraSAR-X imagery. The extraction of hedgerow networks was achieved using an object-oriented method using two polarimetric parameters: the Single Bounce and the Shannon Entropy derived from one TerraSAR-X image. The hedgerow canopy heterogeneity estimated from field measurements was compared with two backscattering coefficients and three polarimetric parameters derived from the same image. The results show that the hedgerow network and its fragmentation can be identified with a very good accuracy (Kappa index: 0.92. This study also reveals the high correlation between one polarimetric parameter, the Shannon entropy, and the canopy fragmentation measured in the field. Therefore, VHSR radar images can both precisely detect the presence of wooded hedgerow networks and characterize their structure, which cannot be achieved with optical images.

  7. Evaluation of the Wishart test statistics for polarimetric SAR data

    DEFF Research Database (Denmark)

    Skriver, Henning; Nielsen, Allan Aasbjerg; Conradsen, Knut

    2003-01-01

    A test statistic for equality of two covariance matrices following the complex Wishart distribution has previously been used in new algorithms for change detection, edge detection and segmentation in polarimetric SAR images. Previously, the results for change detection and edge detection have been...... quantitatively evaluated. This paper deals with the evaluation of segmentation. A segmentation performance measure originally developed for single-channel SAR images has been extended to polarimetric SAR images, and used to evaluate segmentation for a merge-using-moment algorithm for polarimetric SAR data....

  8. H I anisotropies associated with radio-polarimetric filaments . Steep power spectra associated with cold gas

    Science.gov (United States)

    Kalberla, P. M. W.; Kerp, J.; Haud, U.; Haverkorn, M.

    2017-10-01

    Context. LOFAR detected toward 3C 196 linear polarization structures which were found subsequently to be closely correlated with cold filamentary H I structures. The derived direction-dependent H I power spectra revealed marked anisotropies for narrow ranges in velocity, sharing the orientation of the magnetic field as expected for magneto-hydrodynamical (MHD) turbulence. Aims: Using the Galactic portion of the Effelsberg-Bonn H I Survey (EBHIS) we continue our study of such anisotropies in the H I distribution in direction of two WSRT fields, Horologium and Auriga; both are well known for their prominent radio-polarimetric depolarization canals. At 349 MHz the observed pattern in total intensity is insignificant but polarized intensity and polarization angle show prominent ubiquitous structures with so far unknown origin. Methods: Apodizing the H I survey data by applying a rotational symmetric 50% Tukey window, we derive average and position angle dependent power spectra. We fit power laws and characterize anisotropies in the power distribution. We used a Gaussian analysis to determine relative abundances for the cold and warm neutral medium. Results: For the analyzed radio-polarimetric targets significant anisotropies are detected in the H I power spectra; their position angles are aligned to the prominent depolarization canals, initially detected by WSRT. H I anisotropies are associated with steep power spectra. Steep power spectra, associated with cold gas, are detected also in other fields. Conclusions: Radio-polarimetric depolarization canals are associated with filamentary H I structures that belong to the cold neutral medium (CNM). Anisotropies in the CNM are in this case linked to a steepening of the power-spectrum spectral index, indicating that phase transitions in a turbulent medium occur on all scales. Filamentary H I structures, driven by thermal instabilities, and radio-polarimetric filaments are associated with each other. The magneto-ionic medium

  9. Efficient polarimetric BRDF model.

    Science.gov (United States)

    Renhorn, Ingmar G E; Hallberg, Tomas; Boreman, Glenn D

    2015-11-30

    The purpose of the present manuscript is to present a polarimetric bidirectional reflectance distribution function (BRDF) model suitable for hyperspectral and polarimetric signature modelling. The model is based on a further development of a previously published four-parameter model that has been generalized in order to account for different types of surface structures (generalized Gaussian distribution). A generalization of the Lambertian diffuse model is presented. The pBRDF-functions are normalized using numerical integration. Using directional-hemispherical reflectance (DHR) measurements, three of the four basic parameters can be determined for any wavelength. This simplifies considerably the development of multispectral polarimetric BRDF applications. The scattering parameter has to be determined from at least one BRDF measurement. The model deals with linear polarized radiation; and in similarity with e.g. the facet model depolarization is not included. The model is very general and can inherently model extreme surfaces such as mirrors and Lambertian surfaces. The complex mixture of sources is described by the sum of two basic models, a generalized Gaussian/Fresnel model and a generalized Lambertian model. Although the physics inspired model has some ad hoc features, the predictive power of the model is impressive over a wide range of angles and scattering magnitudes. The model has been applied successfully to painted surfaces, both dull and glossy and also on metallic bead blasted surfaces. The simple and efficient model should be attractive for polarimetric simulations and polarimetric remote sensing.

  10. Crop Classification by Polarimetric SAR

    DEFF Research Database (Denmark)

    Skriver, Henning; Svendsen, Morten Thougaard; Nielsen, Flemming

    1999-01-01

    Polarimetric SAR-data of agricultural fields have been acquired by the Danish polarimetric L- and C-band SAR (EMISAR) during a number of missions at the Danish agricultural test site Foulum during 1995. The data are used to study the classification potential of polarimetric SAR data using...

  11. Offshore platform sourced pollution monitoring using space-borne fully polarimetric C and X band synthetic aperture radar.

    Science.gov (United States)

    Singha, Suman; Ressel, Rudolf

    2016-11-15

    Use of polarimetric SAR data for offshore pollution monitoring is relatively new and shows great potential for operational offshore platform monitoring. This paper describes the development of an automated oil spill detection chain for operational purposes based on C-band (RADARSAT-2) and X-band (TerraSAR-X) fully polarimetric images, wherein we use polarimetric features to characterize oil spills and look-alikes. Numbers of near coincident TerraSAR-X and RADARSAT-2 images have been acquired over offshore platforms. Ten polarimetric feature parameters were extracted from different types of oil and 'look-alike' spots and divided into training and validation dataset. Extracted features were then used to develop a pixel based Artificial Neural Network classifier. Mutual information contents among extracted features were assessed and feature parameters were ranked according to their ability to discriminate between oil spill and look-alike spots. Polarimetric features such as Scattering Diversity, Surface Scattering Fraction and Span proved to be most suitable for operational services. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Direction-dependent Corrections in Polarimetric Radio Imaging. I. Characterizing the Effects of the Primary Beam on Full-Stokes Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Jagannathan, P.; Bhatnagar, S.; Rau, U. [National Radio Astronomy Observatory, Socorro (United States); Taylor, A. R., E-mail: pjaganna@nrao.edu [Department of Astronomy, University of Cape Town (South Africa)

    2017-08-01

    Next generation radio telescope arrays are being designed and commissioned to accurately measure polarized intensity and rotation measures (RMs) across the entire sky through deep, wide-field radio interferometric surveys. Radio interferometer dish antenna arrays are affected by direction-dependent (DD) gains due to both instrumental and atmospheric effects. In this paper, we demonstrate the effect of DD errors of the parabolic dish antenna array on the measured polarized intensities of radio sources in interferometric images. We characterize the extent of polarimetric image degradation due to the DD gains through wide-band VLA simulations of representative point-source simulations of the radio sky at L band (1–2 GHz). We show that at the 0.5 gain level of the primary beam there is significant flux leakage from Stokes I to Q , U amounting to 10% of the total intensity. We further demonstrate that while the instrumental response averages down for observations over large parallactic angle intervals, full-polarization DD correction is required to remove the effects of DD leakage. We also explore the effect of the DD beam on the RM signals and show that while the instrumental effect is primarily centered around 0 rad-m{sup −2}, the effect is significant over a broad range of RM requiring full polarization DD correction to accurately reconstruct the RM synthesis signal.

  13. Development and Validation of a Polarimetric-MCScene 3D Atmospheric Radiation Model

    Energy Technology Data Exchange (ETDEWEB)

    Berk, Alexander [Spectral Sciences, Inc., Burlington, MA (United States); Hawes, Frederick [Spectral Sciences, Inc., Burlington, MA (United States); Fox, Marsha [Spectral Sciences, Inc., Burlington, MA (United States)

    2016-03-15

    Polarimetric measurements can substantially enhance the ability of both spectrally resolved and single band imagery to detect the proliferation of weapons of mass destruction, providing data for locating and identifying facilities, materials, and processes of undeclared and proliferant nuclear weapons programs worldwide. Unfortunately, models do not exist that efficiently and accurately predict spectral polarized signatures for the materials of interest embedded in complex 3D environments. Having such a model would enable one to test hypotheses and optimize both the enhancement of scene contrast and the signal processing for spectral signature extraction. The Phase I set the groundwork for development of fully validated polarimetric spectral signature and scene simulation models. This has been accomplished 1. by (a) identifying and downloading state-of-the-art surface and atmospheric polarimetric data sources, (b) implementing tools for generating custom polarimetric data, and (c) identifying and requesting US Government funded field measurement data for use in validation; 2. by formulating an approach for upgrading the radiometric spectral signature model MODTRAN to generate polarimetric intensities through (a) ingestion of the polarimetric data, (b) polarimetric vectorization of existing MODTRAN modules, and (c) integration of a newly developed algorithm for computing polarimetric multiple scattering contributions; 3. by generating an initial polarimetric model that demonstrates calculation of polarimetric solar and lunar single scatter intensities arising from the interaction of incoming irradiances with molecules and aerosols; 4. by developing a design and implementation plan to (a) automate polarimetric scene construction and (b) efficiently sample polarimetric scattering and reflection events, for use in a to be developed polarimetric version of the existing first-principles synthetic scene simulation model, MCScene; and 5. by planning a validation field

  14. Microphysical retrievals from simultaneous polarimetric and profiling radar observations

    Directory of Open Access Journals (Sweden)

    M. P. Morris

    2009-12-01

    Full Text Available The character of precipitation detected at the surface is the final product of many microphysical interactions in the cloud above, the combined effects of which may be characterized by the observed drop size distribution (DSD. This necessitates accurate retrieval of the DSD from remote sensing data, especially radar as it offers large areal coverage, high spatial resolution, and rigorous quality control and testing. Combined instrument observations with a UHF wind profiler, an S-band polarimetric weather radar, and a video disdrometer are analyzed for two squall line events occuring during the calendar year 2007. UHF profiler Doppler velocity spectra are used to estimate the DSD aloft, and are complemented by DSDs retrieved from an exponential model applied to polarimetric data. Ground truth is provided by the disdrometer. A complicating factor in the retrieval from UHF profiler spectra is the presence of ambient air motion, which can be corrected using the method proposed by Teshiba et al. (2009, in which a comparison between idealized Doppler spectra calculated from the DSDs retrieved from KOUN and those retrieved from contaminated wind profiler spectra is performed. It is found that DSDs measured using the distrometer at the surface and estimated using the wind profiler and polarimetric weather radar generally showed good agreement. The DSD retrievals using the wind profiler were improved when the estimates of the vertical wind were included into the analysis, thus supporting the method of Teshiba et al. (2009. Furthermore, the the study presents a method of investigating the time and height structure of DSDs.

  15. Polarimetric neutron scattering

    International Nuclear Information System (INIS)

    Tasset, F.

    2001-01-01

    Polarimetric Neutron Scattering in introduced, both by, explaining methodological issues and the corresponding instrumental developments. After a short overview of neutron spin polarization and the neutron polarization 3d-vector a pictorial approach of the microscopic theory is used to show how a polarized beam interacts with lattice and magnetic Fourier components in a crystal. Examples are given of using Spherical Neutron Polarimetry (SNP) and the corresponding Cryopad polarimeter for the investigation of non-collinear magnetic structures. (R.P.)

  16. Comparison of polarimetric cameras

    Science.gov (United States)

    2017-03-01

    Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget , Paperwork Reduction Project (0704-0188...polarimetric camera, remote sensing, space systems 15. NUMBER OF PAGES 93 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT Unclassified 18...2016. Hermann Hall, Monterey, CA. The next data in Figure 37. were collected on 01 December 2016 at 1226 PST on the rooftop of the Marriot Hotel in

  17. Signal anomaly detection and characterization

    International Nuclear Information System (INIS)

    Morgenstern, V.M.; Upadhyaya, B.R.; Gloeckler, O.

    1988-08-01

    As part of a comprehensive signal validation system, we have developed a signal anomaly detector, without specifically establishing the cause of the anomaly. A signal recorded from process instrumentation is said to have an anomaly, if during steady-state operation, the deviation in the level of the signal, its root-mean-square (RMS) value, or its statistical distribution changes by a preset value. This deviation could be an unacceptable increase or a decrease in the quantity being monitored. An anomaly in a signal may be characterized by wideband or single-frequency noise, bias error, pulse-type error, nonsymmetric behavior, or a change in the signal bandwidth. Various signatures can be easily computed from data samples and compared against specified threshold values. We want to point out that in real processes, pulses can appear with different time widths, and at different rates of change of the signal. Thus, in characterizing an anomaly as a pulse-type, the fastest pulse width is constrained by the signal sampling interval. For example, if a signal is sampled at 100 Hz, we will not be able to detect pulses occurring at kHz rates. Discussion with utility and Combustion Engineering personnel indicated that it is not practical to detect pulses having a narrow time width. 9 refs., 11 figs., 8 tabs

  18. POLAMI: Polarimetric Monitoring of Active Galactic Nuclei at Millimetre Wavelengths - III. Characterization of total flux density and polarization variability of relativistic jets

    Science.gov (United States)

    Agudo, Iván; Thum, Clemens; Ramakrishnan, Venkatessh; Molina, Sol N.; Casadio, Carolina; Gómez, José L.

    2018-01-01

    We report on the first results of the POLAMI (Polarimetric Monitoring of AGNs with Millimetre Wavelengths) programme, a simultaneous 3.5 and 1.3 mm full-Stokes-polarization monitoring of a sample of 36 of the brightest active galactic nuclei in the northern sky with the IRAM 30 m telescope. Through a systematic statistical study of data taken from 2006 October (from 2009 December for the case of the 1.3 mm observations) to 2014 August, we characterize the variability of the total flux density and linear polarization. We find that all sources in the sample are highly variable in total flux density at both 3.5 and 1.3 mm, as well as in spectral index, which (except in particularly prominent flares) is found to be optically thin between these two wavelengths. The total flux-density variability at 1.3 mm is found, in general, to be faster, and to have larger fractional amplitude and flatter power-spectral-density slopes than at 3.5 mm. The polarization degree is on average larger at 1.3 mm than at 3.5 mm, by a factor of 2.6. The variability of linear polarization degree is faster and has higher fractional amplitude than for total flux density, with the typical time-scales during prominent polarization peaks being significantly faster at 1.3 mm than at 3.5 mm. The polarization angle at both 3.5 and 1.3 mm is highly variable. Most of the sources show one or two excursions of >180° on time-scales from a few weeks to about a year during the course of our observations. The 3.5 and 1.3 mm polarization angle evolution follows each other rather well, although the 1.3 mm data show a clear preference to more prominent variability on the short time-scales, i.e. weeks. The data are compatible with multizone models of conical jets involving smaller emission regions for the shortest-wavelength emitting sites. Such smaller emitting regions should also be more efficient in energising particle populations, as implied by the coherent evolution of the spectral index and the total flux

  19. Polarimetric synthetic aperture radar data and the complex Wishart distribution

    DEFF Research Database (Denmark)

    Nielsen, Allan Aasbjerg; Conradsen, Knut; Skriver, Henning

    2003-01-01

    distribution. Based on this distribution a test statistic for equality of two such matrices and an associated asymptotic probability for obtaining a smaller value of the test statistic are given and applied to segmentation, change detection and edge detection in polarimetric SAR data. In a case study EMISAR L...

  20. Snapshot spectral and polarimetric imaging; target identification with multispectral video

    Science.gov (United States)

    Bartlett, Brent D.; Rodriguez, Mikel D.

    2013-05-01

    As the number of pixels continue to grow in consumer and scientific imaging devices, it has become feasible to collect the incident light field. In this paper, an imaging device developed around light field imaging is used to collect multispectral and polarimetric imagery in a snapshot fashion. The sensor is described and a video data set is shown highlighting the advantage of snapshot spectral imaging. Several novel computer vision approaches are applied to the video cubes to perform scene characterization and target identification. It is shown how the addition of spectral and polarimetric data to the video stream allows for multi-target identification and tracking not possible with traditional RGB video collection.

  1. Ambient air contamination: Characterization and detection techniques

    Science.gov (United States)

    Nulton, C. P.; Silvus, H. S.

    1985-01-01

    Techniques to characterize and detect sources of ambient air contamination are described. Chemical techniques to identify indoor contaminants are outlined, they include gas chromatography, or colorimetric detection. Organics generated from indoor materials at ambient conditions and upon combustion are characterized. Piezoelectric quartz crystals are used as precision frequency determining elements in electronic oscillators.

  2. Polsar Land Cover Classification Based on Hidden Polarimetric Features in Rotation Domain and Svm Classifier

    Science.gov (United States)

    Tao, C.-S.; Chen, S.-W.; Li, Y.-Z.; Xiao, S.-P.

    2017-09-01

    Land cover classification is an important application for polarimetric synthetic aperture radar (PolSAR) data utilization. Rollinvariant polarimetric features such as H / Ani / text-decoration: overline">α / Span are commonly adopted in PolSAR land cover classification. However, target orientation diversity effect makes PolSAR images understanding and interpretation difficult. Only using the roll-invariant polarimetric features may introduce ambiguity in the interpretation of targets' scattering mechanisms and limit the followed classification accuracy. To address this problem, this work firstly focuses on hidden polarimetric feature mining in the rotation domain along the radar line of sight using the recently reported uniform polarimetric matrix rotation theory and the visualization and characterization tool of polarimetric coherence pattern. The former rotates the acquired polarimetric matrix along the radar line of sight and fully describes the rotation characteristics of each entry of the matrix. Sets of new polarimetric features are derived to describe the hidden scattering information of the target in the rotation domain. The latter extends the traditional polarimetric coherence at a given rotation angle to the rotation domain for complete interpretation. A visualization and characterization tool is established to derive new polarimetric features for hidden information exploration. Then, a classification scheme is developed combing both the selected new hidden polarimetric features in rotation domain and the commonly used roll-invariant polarimetric features with a support vector machine (SVM) classifier. Comparison experiments based on AIRSAR and multi-temporal UAVSAR data demonstrate that compared with the conventional classification scheme which only uses the roll-invariant polarimetric features, the proposed classification scheme achieves both higher classification accuracy and better robustness. For AIRSAR data, the overall classification

  3. POLSAR LAND COVER CLASSIFICATION BASED ON HIDDEN POLARIMETRIC FEATURES IN ROTATION DOMAIN AND SVM CLASSIFIER

    Directory of Open Access Journals (Sweden)

    C.-S. Tao

    2017-09-01

    Full Text Available Land cover classification is an important application for polarimetric synthetic aperture radar (PolSAR data utilization. Rollinvariant polarimetric features such as H / Ani / α / Span are commonly adopted in PolSAR land cover classification. However, target orientation diversity effect makes PolSAR images understanding and interpretation difficult. Only using the roll-invariant polarimetric features may introduce ambiguity in the interpretation of targets’ scattering mechanisms and limit the followed classification accuracy. To address this problem, this work firstly focuses on hidden polarimetric feature mining in the rotation domain along the radar line of sight using the recently reported uniform polarimetric matrix rotation theory and the visualization and characterization tool of polarimetric coherence pattern. The former rotates the acquired polarimetric matrix along the radar line of sight and fully describes the rotation characteristics of each entry of the matrix. Sets of new polarimetric features are derived to describe the hidden scattering information of the target in the rotation domain. The latter extends the traditional polarimetric coherence at a given rotation angle to the rotation domain for complete interpretation. A visualization and characterization tool is established to derive new polarimetric features for hidden information exploration. Then, a classification scheme is developed combing both the selected new hidden polarimetric features in rotation domain and the commonly used roll-invariant polarimetric features with a support vector machine (SVM classifier. Comparison experiments based on AIRSAR and multi-temporal UAVSAR data demonstrate that compared with the conventional classification scheme which only uses the roll-invariant polarimetric features, the proposed classification scheme achieves both higher classification accuracy and better robustness. For AIRSAR data, the overall classification accuracy

  4. Polarimetric Scattering Properties of Landslides in Forested Areas and the Dependence on the Local Incidence Angle

    Directory of Open Access Journals (Sweden)

    Takashi Shibayama

    2015-11-01

    Full Text Available This paper addresses the local incidence angle dependence of several polarimetric indices corresponding to landslides in forested areas. Landslide is deeply related to the loss of human lives and their property. Various kinds of remote sensing techniques, including aerial photography, high-resolution optical satellite imagery, LiDAR and SAR interferometry (InSAR, have been available for landslide investigations. SAR polarimetry is potentially an effective measure to investigate landslides because fully-polarimetric SAR (PolSAR data contain more information compared to conventional single- or dual-polarization SAR data. However, research on landslide recognition utilizing polarimetric SAR (PolSAR is quite limited. Polarimetric properties of landslides have not been examined quantitatively so far. Accordingly, we examined the polarimetric scattering properties of landslides by an assessment of how the decomposed scattering power components and the polarimetric correlation coefficient change with the local incidence angle. In the assessment, PolSAR data acquired from different directions with both spaceborne and airborne SARs were utilized. It was found that the surface scattering power and the polarimetric correlation coefficient of landslides significantly decrease with the local incidence angle, while these indices of surrounding forest do not. This fact leads to establishing a method of effective detection of landslide area by polarimetric information.

  5. Authentication of gold nanoparticle encoded pharmaceutical tablets using polarimetric signatures.

    Science.gov (United States)

    Carnicer, Artur; Arteaga, Oriol; Suñé-Negre, Josep M; Javidi, Bahram

    2016-10-01

    The counterfeiting of pharmaceutical products represents concerns for both industry and the safety of the general public. Falsification produces losses to companies and poses health risks for patients. In order to detect fake pharmaceutical tablets, we propose producing film-coated tablets with gold nanoparticle encoding. These coated tablets contain unique polarimetric signatures. We present experiments to show that ellipsometric optical techniques, in combination with machine learning algorithms, can be used to distinguish genuine and fake samples. To the best of our knowledge, this is the first report using gold nanoparticles encoded with optical polarimetric classifiers to prevent the counterfeiting of pharmaceutical products.

  6. Assessment of tissue polarimetric properties using Stokes polarimetric imaging with circularly polarized illumination.

    Science.gov (United States)

    Qi, Ji; He, Honghui; Lin, Jianyu; Dong, Yang; Chen, Dongsheng; Ma, Hui; Elson, Daniel S

    2018-04-01

    Tissue-depolarization and linear-retardance are the main polarization characteristics of interest for bulk tissue characterization, and are normally interpreted from Mueller polarimetry. Stokes polarimetry can be conducted using simpler instrumentation and in a shorter time. Here, we use Stokes polarimetric imaging with circularly polarized illumination to assess the circular-depolarization and linear-retardance properties of tissue. Results obtained were compared with Mueller polarimetry in transmission and reflection geometry, respectively. It is found that circular-depolarization obtained from these 2 methods is very similar in both geometries, and that linear-retardance is highly quantitatively similar for transmission geometry and qualitatively similar for reflection geometry. The majority of tissue circular-depolarization and linear-retardance image information (represented by local image contrast features) obtained from Mueller polarimetry is well preserved from Stokes polarimetry in both geometries. These findings can be referred to for further understanding tissue Stokes polarimetric data, and for further application of Stokes polarimetry under the circumstances where short acquisition time or low optical system complexity is a priority, such as polarimetric endoscopy and microscopy. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. POLCAL - POLARIMETRIC RADAR CALIBRATION

    Science.gov (United States)

    Vanzyl, J.

    1994-01-01

    Calibration of polarimetric radar systems is a field of research in which great progress has been made over the last few years. POLCAL (Polarimetric Radar Calibration) is a software tool intended to assist in the calibration of Synthetic Aperture Radar (SAR) systems. In particular, POLCAL calibrates Stokes matrix format data produced as the standard product by the NASA/Jet Propulsion Laboratory (JPL) airborne imaging synthetic aperture radar (AIRSAR). POLCAL was designed to be used in conjunction with data collected by the NASA/JPL AIRSAR system. AIRSAR is a multifrequency (6 cm, 24 cm, and 68 cm wavelength), fully polarimetric SAR system which produces 12 x 12 km imagery at 10 m resolution. AIRSTAR was designed as a testbed for NASA's Spaceborne Imaging Radar program. While the images produced after 1991 are thought to be calibrated (phase calibrated, cross-talk removed, channel imbalance removed, and absolutely calibrated), POLCAL can and should still be used to check the accuracy of the calibration and to correct it if necessary. Version 4.0 of POLCAL is an upgrade of POLCAL version 2.0 released to AIRSAR investigators in June, 1990. New options in version 4.0 include automatic absolute calibration of 89/90 data, distributed target analysis, calibration of nearby scenes with calibration parameters from a scene with corner reflectors, altitude or roll angle corrections, and calibration of errors introduced by known topography. Many sources of error can lead to false conclusions about the nature of scatterers on the surface. Errors in the phase relationship between polarization channels result in incorrect synthesis of polarization states. Cross-talk, caused by imperfections in the radar antenna itself, can also lead to error. POLCAL reduces cross-talk and corrects phase calibration without the use of ground calibration equipment. Removing the antenna patterns during SAR processing also forms a very important part of the calibration of SAR data. Errors in the

  8. Polarimetric Imaging using Two Photoelastic Modulators

    Science.gov (United States)

    Wang, Yu; Cunningham, Thomas; Diner, David; Davis, Edgar; Sun, Chao; Hancock, Bruce; Gutt, Gary; Zan, Jason; Raouf, Nasrat

    2009-01-01

    A method of polarimetric imaging, now undergoing development, involves the use of two photoelastic modulators in series, driven at equal amplitude but at different frequencies. The net effect on a beam of light is to cause (1) the direction of its polarization to rotate at the average of two excitation frequencies and (2) the amplitude of its polarization to be modulated at the beat frequency (the difference between the two excitation frequencies). The resulting modulated optical light beam is made to pass through a polarizing filter and is detected at the beat frequency, which can be chosen to equal the frame rate of an electronic camera or the rate of sampling the outputs of photodetectors in an array. The method was conceived to satisfy a need to perform highly accurate polarimetric imaging, without cross-talk between polarization channels, at frame rates of the order of tens of hertz. The use of electro-optical modulators is necessitated by a need to obtain accuracy greater than that attainable by use of static polarizing filters over separate fixed detectors. For imaging, photoelastic modulators are preferable to such other electrio-optical modulators as Kerr cells and Pockels cells in that photoelastic modulators operate at lower voltages, have greater angular acceptances, and are easier to use. Prior to the conception of the present method, polarimetric imaging at frame rates of tens of hertz using photoelastic modulators was not possible because the resonance frequencies of photoelastic modulators usually lie in the range from about 20 to about 100 kHz.

  9. Lightning Initiation Forecasting: An Operational Dual-Polarimetric Radar Technique

    Science.gov (United States)

    Woodard, Crystal J.; Carey, L. D.; Petersen, W. A.; Roeder, W. P.

    2011-01-01

    The objective of this NASA MSFC and NOAA CSTAR funded study is to develop and test operational forecast algorithms for the prediction of lightning initiation utilizing the C-band dual-polarimetric radar, UAHuntsville's Advanced Radar for Meteorological and Operational Research (ARMOR). Although there is a rich research history of radar signatures associated with lightning initiation, few studies have utilized dual-polarimetric radar signatures (e.g., Z(sub dr) columns) and capabilities (e.g., fuzzy-logic particle identification [PID] of precipitation ice) in an operational algorithm for first flash forecasting. The specific goal of this study is to develop and test polarimetric techniques that enhance the performance of current operational radar reflectivity based first flash algorithms. Improving lightning watch and warning performance will positively impact personnel safety in both work and leisure environments. Advanced warnings can provide space shuttle launch managers time to respond appropriately to secure equipment and personnel, while they can also provide appropriate warnings for spectators and players of leisure sporting events to seek safe shelter. Through the analysis of eight case dates, consisting of 35 pulse-type thunderstorms and 20 non-thunderstorm case studies, lightning initiation forecast techniques were developed and tested. The hypothesis is that the additional dual-polarimetric information could potentially reduce false alarms while maintaining high probability of detection and increasing lead-time for the prediction of the first lightning flash relative to reflectivity-only based techniques. To test the hypothesis, various physically-based techniques using polarimetric variables and/or PID categories, which are strongly correlated to initial storm electrification (e.g., large precipitation ice production via drop freezing), were benchmarked against the operational reflectivity-only based approaches to find the best compromise between

  10. Nonlinear Polarimetric Microscopy for Biomedical Imaging

    Science.gov (United States)

    Samim, Masood

    A framework for the nonlinear optical polarimetry and polarimetric microscopy is developed. Mathematical equations are derived in terms of linear and nonlinear Stokes Mueller formalism, which comprehensively characterize the polarization properties of the incoming and outgoing radiations, and provide structural information about the organization of the investigated materials. The algebraic formalism developed in this thesis simplifies many predictions for a nonlinear polarimetry study and provides an intuitive understanding of various polarization properties for radiations and the intervening medium. For polarimetric microscopy experiments, a custom fast-scanning differential polarization microscope is developed, which is also capable of real-time three-dimensional imaging. The setup is equipped with a pair of high-speed resonant and galvanometric scanning mirrors, and supplemented by advanced adaptive optics and data acquisition modules. The scanning mirrors when combined with the adaptive optics deformable mirror enable fast 3D imaging. Deformable membrane mirrors and genetic algorithm optimization routines are employed to improve the imaging conditions including correcting the optical aberrations, maximizing signal intensities, and minimizing point-spread-functions of the focal volume. A field-programmable-gate array (FPGA) chip is exploited to rapidly acquire and process the multidimensional data. Using the nonlinear optical polarimetry framework and the home-built polarization microscope, a few biologically important tissues are measured and analyzed to gain insight as to their structure and dynamics. The structure and distribution of muscle sarcomere myosins, connective tissue collagen, carbohydrate-rich starch, and fruit fly eye retinal molecules are characterized with revealing polarization studies. In each case, using the theoretical framework, polarization sensitive data are analyzed to decipher the molecular orientations and nonlinear optical

  11. The NASA Polarimetric Radar (NPOL)

    Science.gov (United States)

    Petersen, Walter A.; Wolff, David B.

    2013-01-01

    Characteristics of the NASA NPOL S-band dual-polarimetric radar are presented including its operating characteristics, field configuration, scanning capabilities and calibration approaches. Examples of precipitation science data collections conducted using various scan types, and associated products, are presented for different convective system types and previous field campaign deployments. Finally, the NASA NPOL radar location is depicted in its home base configuration within the greater Wallops Flight Facility precipitation research array supporting NASA Global Precipitation Measurement Mission ground validation.

  12. MCM Polarimetric Radiometers for Planar Arrays

    Science.gov (United States)

    Kangaslahti, Pekka; Dawson, Douglas; Gaier, Todd

    2007-01-01

    A polarimetric radiometer that operates at a frequency of 40 GHz has been designed and built as a prototype of multiple identical units that could be arranged in a planar array for scientific measurements. Such an array is planned for use in studying the cosmic microwave background (CMB). All of the subsystems and components of this polarimetric radiometer are integrated into a single multi-chip module (MCM) of substantially planar geometry. In comparison with traditional designs of polarimetric radiometers, the MCM design is expected to greatly reduce the cost per unit in an array of many such units. The design of the unit is dictated partly by a requirement, in the planned CMB application, to measure the Stokes parameters I, Q, and U of the CMB radiation with high sensitivity. (A complete definition of the Stokes parameters would exceed the scope of this article. In necessarily oversimplified terms, I is a measure of total intensity of radiation, while Q and U are measures of the relationships between the horizontally and vertically polarized components of radiation.) Because the sensitivity of a single polarimeter cannot be increased significantly, the only way to satisfy the high-sensitivity requirement is to make a large array of polarimeters that operate in parallel. The MCM includes contact pins that can be plugged into receptacles on a standard printed-circuit board (PCB). All of the required microwave functionality is implemented within the MCM; any required supporting non-microwave ("back-end") electronic functionality, including the provision of DC bias and control signals, can be implemented by standard PCB techniques. On the way from a microwave antenna to the MCM, the incoming microwave signal passes through an orthomode transducer (OMT), which splits the radiation into an h + i(nu) beam and an h - i(nu) beam (where, using complex-number notation, h denotes the horizontal component, nu denotes the vertical component, and +/-i denotes a +/-90deg phase

  13. A fiber-optic polarimetric demonstration kit

    International Nuclear Information System (INIS)

    Eftimov, T; Dimitrova, T L; Ivanov, G

    2012-01-01

    A simple and multifunctional fiber-optic polarimetric kit on the basis of highly birefringent single-mode fibers is presented. The fiber-optic polarimetric kit allows us to perform the following laboratory exercises: (i) fiber excitation and the measurement of numerical aperture, (ii) polarization preservation and (iii) obtain polarization-sensitive fiberized interferometers.

  14. Screening Mississippi River Levees Using Texture-Based and Polarimetric-Based Features from Synthetic Aperture Radar Data

    Directory of Open Access Journals (Sweden)

    Lalitha Dabbiru

    2017-03-01

    Full Text Available This article reviews the use of synthetic aperture radar remote sensing data for earthen levee mapping with an emphasis on finding the slump slides on the levees. Earthen levees built on the natural levees parallel to the river channel are designed to protect large areas of populated and cultivated land in the Unites States from flooding. One of the signs of potential impending levee failure is the appearance of slump slides. On-site inspection of levees is expensive and time-consuming; therefore, a need to develop efficient techniques based on remote sensing technologies is mandatory to prevent failures under flood loading. Analysis of multi-polarized radar data is one of the viable tools for detecting the problem areas on the levees. In this study, we develop methods to detect anomalies on the levee, such as slump slides and give levee managers new tools to prioritize their tasks. This paper presents results of applying the National Aeronautics and Space Administration (NASA Jet Propulsion Lab (JPL’s Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR quad-polarized L-band data to detect slump slides on earthen levees. The study area encompasses a portion of levees of the lower Mississippi River in the United States. In this paper, we investigate the performance of polarimetric and texture features for efficient levee classification. Texture features derived from the gray level co-occurrence (GLCM matrix and discrete wavelet transform were computed and analyzed for efficient levee classification. The pixel-based polarimetric decomposition features, such as entropy, anisotropy, and scattering angle were also computed and applied to the support vector machine classifier to characterize the radar imagery and compared the results with texture-based classification. Our experimental results showed that inclusion of textural features derived from the SAR data using the discrete wavelet transform (DWT features and GLCM features provided

  15. Space-borne polarimetric SAR sensors or the golden age of radar polarimetry

    Directory of Open Access Journals (Sweden)

    Pottier E.

    2010-06-01

    Full Text Available SAR Polarimetry represents an active area of research in Active Earth Remote Sensing. This interest is clearly supported by the fact that nowadays there exists, or there will exist in a very next future, a non negligible quantity of launched Polarimetric SAR Spaceborne sensors. The ENVISAT satellite, developed by ESA, was launched on March 2002, and was the first Spaceborne sensor offering an innovative dualpolarization Advanced Synthetic Aperture Radar (ASAR system operating at C-band. The second Polarimetric Spaceborne sensor is ALOS, a Japanese Earth-Observation satellite, developed by JAXA and was launched in January 2006. This mission includes an active L-band polarimetric radar sensor (PALSAR whose highresolution data may be used for environmental and hazard monitoring. The third Polarimetric Spaceborne sensor is TerraSAR-X, a new German radar satellite, developed by DLR, EADS-Astrium and Infoterra GmbH, was launched on June 2007. This sensor carries a dual-polarimetric and high frequency X-Band SAR sensor that can be operated in different modes and offers features that were not available from space before. At least, the Polarimetric Spaceborne sensor, developed by CSA and MDA, and named RADARSAT-2 was launched in December 2007 The Radarsat program was born out the need for effective monitoring of Canada’s icy waters, and some Radarsat-2 capabilities that benefit sea- and river ice applications are the multi-polarization options that will improve ice-edge detection, ice-type discrimination and structure information. The many advances in these different Polarimetric Spaceborne platforms were developed to respond to specific needs for radar data in environmental monitoring applications around the world, like : sea- and river-ice monitoring, marine surveillance, disaster management, oil spill detection, snow monitoring, hydrology, mapping, geology, agriculture, soil characterisation, forestry applications (biomass, allometry, height

  16. The Detection and Characterization of Extrasolar Planets

    Directory of Open Access Journals (Sweden)

    Ken Rice

    2014-09-01

    Full Text Available We have now confirmed the existence of > 1800 planets orbiting stars other thanthe Sun; known as extrasolar planets or exoplanets. The different methods for detectingsuch planets are sensitive to different regions of parameter space, and so, we are discoveringa wide diversity of exoplanets and exoplanetary systems. Characterizing such planets isdifficult, but we are starting to be able to determine something of their internal compositionand are beginning to be able to probe their atmospheres, the first step towards the detectionof bio-signatures and, hence, determining if a planet could be habitable or not. Here, Iwill review how we detect exoplanets, how we characterize exoplanetary systems and theexoplanets themselves, where we stand with respect to potentially habitable planets and howwe are progressing towards being able to actually determine if a planet could host life or not.

  17. Polarimetric Segmentation Using Wishart Test Statistic

    DEFF Research Database (Denmark)

    Skriver, Henning; Schou, Jesper; Nielsen, Allan Aasbjerg

    2002-01-01

    A newly developed test statistic for equality of two complex covariance matrices following the complex Wishart distribution and an associated asymptotic probability for the test statistic has been used in a segmentation algorithm. The segmentation algorithm is based on the MUM (merge using moments......) approach, which is a merging algorithm for single channel SAR images. The polarimetric version described in this paper uses the above-mentioned test statistic for merging. The segmentation algorithm has been applied to polarimetric SAR data from the Danish dual-frequency, airborne polarimetric SAR, EMISAR...

  18. Searching for Jet Emission in LMXBs: A Polarimetric View

    Directory of Open Access Journals (Sweden)

    Maria Cristina Baglio

    2017-10-01

    Full Text Available We present results taken from a study aiming at detecting the emission from relativistic particles jets in neutron star-low mass X-ray binaries using optical polarimetric observations. First, we focus on a polarimetric study performed on the persistent LMXB 4U 0614+091. Once corrected for interstellar effects, we measured an intrinsic linear polarization in the r-band of ~3% at a 3σ confidence level. This is in-line with the observation of an infrared excess in the spectral energy distribution (SED of the source, reported in a previous work, which the authors linked to the optically thin synchrotron emission of a jet. We then present a study performed on the transitional millisecond pulsar PSR J1023+0038 during quiescence. We measured a linear polarization of 1.09 ± 0.27% and 0.90 ± 0.17% in the V and R bands, respectively. The phase-resolved polarimetric curve of the source in the R-band reveals a hint of a sinusoidal modulation at the source orbital period. The NIR -optical SED of the system did not suggest the presence of a jet. We conclude that the optical linear polarization observed for PSR J1023+0038 is possibly due to Thomson scattering with electrons in the disc, as also suggested by the hint of the modulation of the R-band linear polarization at the system orbital period.

  19. ASTEROID POLARIMETRIC DATABASE V6.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The Asteroid Polarimetric Database (APD) is a collection of asteroid polarimetry results compiled by D.F. Lupishko and S.V. Vasiliev of Karazin Kharkiv National...

  20. Novel Polarimetric SAR Interferometry Algorithms, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Polarimetric radar interferometry (PolInSAR) is a new SAR imaging mode that is rapidly becoming an important technique for bare earth topographic mapping, tree...

  1. Complex Wishart distribution based analysis of polarimetric synthetic aperture radar data

    DEFF Research Database (Denmark)

    Nielsen, Allan Aasbjerg; Skriver, Henning; Conradsen, Knut

    2007-01-01

    statistic for equality of two such matrices and an associated asymptotic probability for obtaining a smaller value of the test statistic are given and applied to change detection, edge detection and segmentation in polarimetric SAR data. In a case study EMISAR L-band data from 17 April 1998 and 20 May 1998...

  2. Polarimetric Signatures from a Crop Covered Land Surface Measured by an L-band Polarimetric Radiometer

    DEFF Research Database (Denmark)

    Søbjærg, Sten Schmidl; Skou, Niels

    2003-01-01

    This paper describes preliminary results from field measurements of polarimetric azimuth signatures with the EMIRAD L-band polarimetric radiometer, performed over a land test site at the Institut National de la Recherche Agronomique in Avignon, France. Scans of 180 degrees in azimuth were carried...

  3. Characterizing Enzymatic Deposition for Microelectrode Neurotransmitter Detection

    Energy Technology Data Exchange (ETDEWEB)

    Hosein, W. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Yorita, A. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Tolosa, V. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-08-12

    The enzyme immobilization process, one step in creating an enzymatic biosensor, was characterized and analyzed as a function of its physical properties. The neural glutamic biosensor is a flexible device, effectively minimizing trauma to the area of implantation. The Multielectrode Array (MEA) is composed primarily of a proprietary polymer which has been successfully implanted into human subjects in recent years. This polymer allows the device the pliability that other devices normally lack, though this poses some challenges to implantation. The electrodes are made of Platinum (Pt), and can range in number from eight to thirty two electrodes per device. These electrodes are electroplated with a semipermeable polymer layer to improve selectivity of the electrode to the neurotransmitter of interest, in this case glutamate. A signal is created from the interaction of glutamate in the brain with the glutamate oxidase (GluOx) which is immobilized on the surface of the electrode by using crosslinking chemistry in conjunction with glutaraldehyde and Bovine Serum Albumin (BSA). The glutamate is oxidized by glutamate oxidase, producing α-ketoglutarate and hydrogen peroxide (H2O2) as a by-product. The production of H2O2 is crucial for detection of the presence of the glutamate within the enzymatic coating, as it diffuses through the enzyme layer and oxidizes at the surface of the electrode. This oxidation is detectable by measurable change in the current using amperometry. Hence, the MEA allows for in vivo monitoring of neurotransmitter activity in real time. The sensitivity of the sensor to these neurotransmitters is dependent on the thickness of the layer, which is investigated in these experiments in order to optimize the efficacy of the device to detecting the substrate, once implanted.

  4. Contribution of multitemporal polarimetric synthetic aperture radar data for monitoring winter wheat and rapeseed crops

    Science.gov (United States)

    Betbeder, Julie; Fieuzal, Remy; Philippets, Yannick; Ferro-Famil, Laurent; Baup, Frederic

    2016-04-01

    This paper aims to evaluate the contribution of multitemporal polarimetric synthetic aperture radar (SAR) data for winter wheat and rapeseed crops parameters [height, leaf area index, and dry biomass (DB)] estimation, during their whole vegetation cycles in comparison to backscattering coefficients and optical data. Angular sensitivities and dynamics of polarimetric indicators were also analyzed following the growth stages of these two common crop types using, in total, 14 radar images (Radarsat-2), 16 optical images (Formosat-2, Spot-4/5), and numerous ground data. The results of this study show the importance of correcting the angular effect on SAR signals especially for copolarized signals and polarimetric indicators associated to single-bounce scattering mechanisms. The analysis of the temporal dynamic of polarimetric indicators has shown their high potential to detect crop growth changes. Moreover, this study shows the high interest of using SAR parameters (backscattering coefficients and polarimetric indicators) for crop parameters estimation during the whole vegetation cycle instead of optical vegetation index. They particularly revealed their high potential for rapeseed height and DB monitoring [i.e., Shannon entropy polarimetry (r2=0.70) and radar vegetation index (r2=0.80), respectively].

  5. Three axis vector atomic magnetometer utilizing polarimetric technique

    Energy Technology Data Exchange (ETDEWEB)

    Pradhan, Swarupananda, E-mail: spradhan@barc.gov.in, E-mail: pradhans75@gmail.com [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Mumbai 400085, India and Homi Bhabha National Institute, Department of Atomic Energy, Mumbai 400094 (India)

    2016-09-15

    The three axis vector magnetic field measurement based on the interaction of a single elliptically polarized light beam with an atomic system is described. The magnetic field direction dependent atomic responses are extracted by the polarimetric detection in combination with laser frequency modulation and magnetic field modulation techniques. The magnetometer geometry offers additional critical requirements like compact size and large dynamic range for space application. Further, the three axis magnetic field is measured using only the reflected signal (one polarization component) from the polarimeter and thus can be easily expanded to make spatial array of detectors and/or high sensitivity field gradient measurement as required for biomedical application.

  6. Standoff Polarimetric Aerosol Detection (SPADE) for Biodefense

    Science.gov (United States)

    2005-02-01

    Photograph of colony by J. Ezzell , US Army Medical Research Inst, Fort Detrick, Frederick, MD.] In Figure 3.2, (a) is a cluster of approximately 350...gives a receiver aperture radius r,, = 0.125 m. The range is not unequivocally set, but R = 1600 m (about I mile ) is representative of outdoor aerial

  7. Detection of land degradation with polarimetric SAR

    Science.gov (United States)

    Ray, Terrill W.; Farr, Tom G.; Van Zyl, Jakob J.

    1992-01-01

    Multispectral radar polarimeter data were collected over the Manix Basin Area of the Mojave desert using an airborne SAR. An analysis of the data reveals unusual polarization responses which are attributed to the formation of wind ripples on the surfaces of fields that have been abandoned for more than 5 years. This hypothesis has been confirmed through field observations, and a second-order perturbation model is shown to effectively model the polarization responses. The results demonstrate the usefulness of remote sensing techniques for the study of land degradation at synoptic scales.

  8. Material Characterization using Passive Multispectral Polarimetric Imagery

    Science.gov (United States)

    2013-03-01

    14 9 Dispersion of White Light Through a Prism . . . . . . . . . . . . . . . . . . . 16 10 Empirical Dispersion Curve of...Corrected, and Theoretical MTF Curves . . . . . . 29 18 Meadowlark Linear Polarizer and 633nm LED source . . . . . . . . . . . . . . 32 19 Proposed MS...versus transversely) in most mediums via compression and rarefaction of the medium ahead of the wave in the direction of propagation. The sound wave pulses

  9. Maritime target and sea clutter measurements with a coherent Doppler polarimetric surveillance radar

    NARCIS (Netherlands)

    Smith, A.J.E.; Gelsema, S.J.; Kester, L.J.H.M.; Melief, H.W.; Premel Cabic, G.; Theil, A.; Woudenberg, E.

    2002-01-01

    Doppler polarimetry in a surveillance radar for the maritime surface picture is considered. This radar must be able to detect low-RCS targets in littoral environments. Measurements on such targets have been conducted with a coherent polarimetric measurement radar in March 2001 and preliminary

  10. POLARIMETRIC OBSERVATIONS OF {sigma} ORIONIS E

    Energy Technology Data Exchange (ETDEWEB)

    Carciofi, A. C.; Faes, D. M. [Instituto de Astronomia, Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo, Rua do Matao 1226, Cidade Universitaria, 05508-900 Sao Paulo, SP (Brazil); Townsend, R. H. D. [Department of Astronomy, University of Wisconsin-Madison, Sterling Hall, 475 N. Charter Street, Madison, WI 53706 (United States); Bjorkman, J. E., E-mail: carciofi@usp.br [Ritter Observatory, Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States)

    2013-03-20

    Some massive stars possess strong magnetic fields that confine plasma in the circumstellar environment. These magnetospheres have been studied spectroscopically, photometrically, and, more recently, interferometrically. Here we report on the first firm detection of a magnetosphere in continuum linear polarization, as a result of monitoring {sigma} Ori E at the Pico dos Dias Observatory. The non-zero intrinsic polarization indicates an asymmetric structure whose minor elongation axis is oriented 150. Degree-Sign 0 east of the celestial north. A modulation of the polarization was observed with a period of half of the rotation period, which supports the theoretical prediction of the presence of two diametrally opposed, corotating blobs of gas. A phase lag of -0.085 was detected between the polarization minimum and the primary minimum of the light curve, suggestive of a complex shape of the plasma clouds. We present a preliminary analysis of the data with the Rigidly Rotating Magnetosphere model, which could not reproduce simultaneously the photometric and polarimetric data. A toy model comprising two spherical corotating blobs joined by a thin disk proved more successful in reproducing the polarization modulation. With this model we were able to determine that the total scattering mass of the thin disk is similar to the mass of the blobs (2M{sub b}/M{sub d} = 1.2) and that the blobs are rotating counterclockwise on the plane of the sky. This result shows that polarimetry can provide a diagnostic of the geometry of clouds, which will serve as an important constraint for improving the Rigidly Rotating Magnetosphere model.

  11. PolSAR Land Cover Classification Based on Roll-Invariant and Selected Hidden Polarimetric Features in the Rotation Domain

    Directory of Open Access Journals (Sweden)

    Chensong Tao

    2017-07-01

    Full Text Available Land cover classification is an important application for polarimetric synthetic aperture radar (PolSAR. Target polarimetric response is strongly dependent on its orientation. Backscattering responses of the same target with different orientations to the SAR flight path may be quite different. This target orientation diversity effect hinders PolSAR image understanding and interpretation. Roll-invariant polarimetric features such as entropy, anisotropy, mean alpha angle, and total scattering power are independent of the target orientation and are commonly adopted for PolSAR image classification. On the other aspect, target orientation diversity also contains rich information which may not be sensed by roll-invariant polarimetric features. In this vein, only using the roll-invariant polarimetric features may limit the final classification accuracy. To address this problem, this work uses the recently reported uniform polarimetric matrix rotation theory and a visualization and characterization tool of polarimetric coherence pattern to investigate hidden polarimetric features in the rotation domain along the radar line of sight. Then, a feature selection scheme is established and a set of hidden polarimetric features are selected in the rotation domain. Finally, a classification method is developed using the complementary information between roll-invariant and selected hidden polarimetric features with a support vector machine (SVM/decision tree (DT classifier. Comparison experiments are carried out with NASA/JPL AIRSAR and multi-temporal UAVSAR data. For AIRSAR data, the overall classification accuracy of the proposed classification method is 95.37% (with SVM/96.38% (with DT, while that of the conventional classification method is 93.87% (with SVM/94.12% (with DT, respectively. Meanwhile, for multi-temporal UAVSAR data, the mean overall classification accuracy of the proposed method is up to 97.47% (with SVM/99.39% (with DT, which is also higher

  12. Characterization of hydrometeors in Sahelian convective systems with an X-band radar and comparison with in situ measurements. Part I : Sensitivity of polarimetric radar particle identification retrieval and case study evaluation

    OpenAIRE

    Cazenave, Frédéric; Gosset, Marielle; Kacou, M.; Alcoba, M.; Fontaine, E.; Duroure, C.; Dolan, B.

    2016-01-01

    The particle identification scheme developed by Dolan and Rutledge for X-band polarimetric radar is tested for the first time in Africa and compared with in situ measurements. The data were acquired during the Megha-Tropiques mission algorithm-validation campaign that occurred in Niger in 2010. The radar classification is compared with the in situ observations gathered by an instrumented aircraft for the 13 August 2010 squall-line case. An original approach has been developed for the radar-in...

  13. Science data collection with polarimetric SAR

    DEFF Research Database (Denmark)

    Dall, Jørgen; Woelders, Kim; Madsen, Søren Nørvang

    1996-01-01

    Discusses examples on the use of polarimetric SAR in a number of Earth science studies. The studies are presently being conducted by the Danish Center for Remote Sensing. A few studies of the European Space Agency's EMAC programme are also discussed. The Earth science objectives are presented......, and the potential of polarimetric SAR is discussed and illustrated with data collected by the Danish airborne EMISAR system during a number of experiments in 1994 and 1995. The presentation will include samples of data acquired for the different studies...

  14. Passive Polarimetric Microwave Signatures Observed Over Antarctica

    Science.gov (United States)

    WindSat satellite-based fully polarimetric passive microwave observations, expressed in the form of the Stokes vector, were analyzed over the Antarctic ice sheet. The vertically and horizontally polarized brightness temperatures (first two Stokes components) from WindSat are shown to be consistent w...

  15. Detection and characterization of extrasolar planets

    Directory of Open Access Journals (Sweden)

    Ferlet R.

    2009-02-01

    Full Text Available The main methods to detect planets orbiting stars other than our Sun are briefly described, together with their present results. Some characteristics of the known systems are emphasized. Particularly interesting are the transiting exoplanets which allow to reveal their atmospheres and ultimately identify biosignatures.

  16. Comparisons of Circular Transmit and Linear Receive Compact Polarimetric SAR Features for Oil Slicks Discrimination

    Directory of Open Access Journals (Sweden)

    Yu Li

    2015-01-01

    Full Text Available Compact polarimetric (CP synthetic aperture radar (SAR has proven its potential in distinguishing oil slicks and look-alikes. Polarimetric information can be retrieved directly from scattering vector or from reconstructed pseudo-Quad-Pol covariance matrix of CP SAR data. In this paper, we analysed features from Circular Transmit and Linear Receive (CTLR CP SAR data that are derived by taking both of these two methods. K-means clustering followed by accuracy assessment was also implemented for performance evaluation. Through experiments that were conducted based on L-band UAVSAR fully polarimetric data, it was found that optimum extraction methods varied for different features. The histogram analysis and segmentation results also demonstrated the comparable performance of CP SAR features in distinguishing different damping properties within oil slicks. This study proposed a framework of statistically analyzing polarimetric SAR (Pol-SAR features and provided guidelines for determining optimum feature extraction methods from CP SAR data and for marine oil-spills detection and classification.

  17. CAMEX-3 POLARIMETRIC SCANNING RADIOMETER (PSR) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The Polarimetric Scanning Radiometer (PSR) is a versatile airborne microwave imaging radiometer developed by the Georgia Institute of Technology and the NOAA...

  18. Polarimetric studies of polyethylene terephtalate flexible substrates

    Science.gov (United States)

    Stchakovsky, M.; Garcia-Caurel, E.; Warenghem, M.

    2008-12-01

    Polymer sheets are currently used worldwide in a wide range of applications. The manufacturing process of these sheets involves extruding machines that stretch the material in both lateral and longitudinal directions with respect to the machine direction, thus inducing birefringence. In most cases, the film obtained is optically biaxial. Polarimetric spectroscopy (Ellipsometry and Mueller Matrix) combined with conoscopic observation are the methods of choice to study these properties. In this work we report an analysis of commercially available polyethylene terephtalate (PET) films used as substrate for food packaging as well as for embedded electronic devices such as solar cells or flexible displays. Initial observation of these films through polarizing microscope in conoscopic mode reveals first the trace of optical axis plane with respect to the film surface and second, whether the optical axis is acute or not. This preliminary study allows optimal sample positioning for further polarimetric studies. The measurements and modelling are done in both reflection and transmission mode on several spectroscopic polarimetric setups from UV to NIR. The models give as a main result, the dielectric tensor of the film as well as its orientation with respect to the laboratory reference frame.

  19. Polarimetric signatures of sea ice in the Greenland Sea

    DEFF Research Database (Denmark)

    Skriver, Henning; Pedersen, Leif Toudal

    1995-01-01

    Polarimetric SAR data of sea ice have been acquired by the Danish polarimetric SAR (EMISAR) during a mission at the Greenland Sea in August 1994. Video recordings from a low-altitude acquisition have been used for interpretation of the SAR data. Also, ERS-1 SAR data and NOAA AVHRR-data have been...

  20. EMISAR: A Dual-frequency, Polarimetric Airborne SAR

    DEFF Research Database (Denmark)

    Dall, Jørgen; Christensen, Erik Lintz

    2002-01-01

    EMISAR is a fully polarimetric, dual frequency (L- and C-band) SAR system designed for remote sensing applications. The data are usually processed to 2×2 m resolution. The system has the capability of C-band cross-track single-pass interferometry and fully polarimetric repeat-pass interferometry....

  1. The CASLEO Polarimetric Survey of Main Belt Asteroids: Updated results

    Science.gov (United States)

    Gil-Hutton, R.; Cellino, A.; Cañada-Assandri, M.

    2011-10-01

    We present updated results of the polarimetric survey of main-belt asteroids at Complejo Astronómico El Leoncito (Casleo), San Juan, Argentina, using the 2.15 m telescope and the Torino and CASPROF polarimeters. The goals of this survey are to increase the database of asteroid polarimetry, to estimate diversity in polarimetric properties of asteroids belonging to different taxonomic classes, and to search for objects that exhibit anomalous polarimetric properties. The survey began in 2003, and data for a sample of more than 170 asteroids have been obtained, most of them having been polarimetrically observed for the first time. Using these data we find phase-polarization curves and polarimetric parameters for several taxonomic classes.

  2. Improved flaw detection and characterization with difference thermography

    Science.gov (United States)

    Winfree, William P.; Zalameda, Joseph N.; Howell, Patricia A.

    2011-05-01

    Flaw detection and characterization with thermographic techniques in graphite polymer composites is often limited by localized variations in the thermographic response. Variations in properties such as acceptable porosity, variations in fiber volume content and surface polymer thickness result in variations in the thermal response that in general cause significant variations in the initial thermal response. These variations result in a noise floor that increases the difficulty of detecting and characterizing deeper flaws. The paper investigates comparing thermographic responses taken before and after a change in state in a composite to improve the detection of subsurface flaws. A method is presented for registration of the responses before finding the difference. A significant improvement in the detectability is achieved by comparing the differences in response. Examples of changes in state due to application of a load and impact are presented.

  3. An improved method for polarimetric image restoration in interferometry

    Science.gov (United States)

    Pratley, Luke; Johnston-Hollitt, Melanie

    2016-11-01

    Interferometric radio astronomy data require the effects of limited coverage in the Fourier plane to be accounted for via a deconvolution process. For the last 40 years this process, known as `cleaning', has been performed almost exclusively on all Stokes parameters individually as if they were independent scalar images. However, here we demonstrate for the case of the linear polarization P, this approach fails to properly account for the complex vector nature resulting in a process which is dependent on the axes under which the deconvolution is performed. We present here an improved method, `Generalized Complex CLEAN', which properly accounts for the complex vector nature of polarized emission and is invariant under rotations of the deconvolution axes. We use two Australia Telescope Compact Array data sets to test standard and complex CLEAN versions of the Högbom and SDI (Steer-Dwedney-Ito) CLEAN algorithms. We show that in general the complex CLEAN version of each algorithm produces more accurate clean components with fewer spurious detections and lower computation cost due to reduced iterations than the current methods. In particular, we find that the complex SDI CLEAN produces the best results for diffuse polarized sources as compared with standard CLEAN algorithms and other complex CLEAN algorithms. Given the move to wide-field, high-resolution polarimetric imaging with future telescopes such as the Square Kilometre Array, we suggest that Generalized Complex CLEAN should be adopted as the deconvolution method for all future polarimetric surveys and in particular that the complex version of an SDI CLEAN should be used.

  4. Construction of Polarimetric Radar-Based Reference Rain Maps for the Iowa Flood Studies Campaign

    Science.gov (United States)

    Petersen, Walt; Krajewski, Witek; Wolff, David; Gatlin, Patrick

    2015-04-01

    The Global Precipitation Measurement (GPM) Mission Iowa Flood Studies (IFloodS) campaign was conducted in central and northeastern Iowa during the months of April-June, 2013. Specific science objectives for IFloodS included quantification of uncertainties in satellite and ground-based estimates of precipitation, 4-D characterization of precipitation physical processes and associated parameters (e.g., size distributions, water contents, types, structure etc.), assessment of the impact of precipitation estimation uncertainty and physical processes on hydrologic predictive skill, and refinement of field observations and data analysis approaches as they pertain to future GPM integrated hydrologic validation and related field studies. In addition to field campaign archival of raw and processed satellite data (including precipitation products), key ground-based platforms such as the NASA NPOL S-band and D3R Ka/Ku-band dual-polarimetric radars, University of Iowa X-band dual-polarimetric radars, a large network of paired rain gauge platforms, and a large network of 2D Video and Parsivel disdrometers were deployed. In something of a canonical approach, the radar (NPOL in particular), gauge and disdrometer observational assets were deployed to create a consistent high-quality distributed (time and space sampling) radar-based ground "reference" rainfall dataset, with known uncertainties, that could be used for assessing the satellite-based precipitation products at a range of space/time scales. Subsequently, the impact of uncertainties in the satellite products could be evaluated relative to the ground-benchmark in coupled weather, land-surface and distributed hydrologic modeling frameworks as related to flood prediction. Relative to establishing the ground-based "benchmark", numerous avenues were pursued in the making and verification of IFloodS "reference" dual-polarimetric radar-based rain maps, and this study documents the process and results as they pertain specifically

  5. Construction of Polarimetric Radar-Based Reference Rain Maps for the Iowa Flood Studies Campaign

    Science.gov (United States)

    Petersen, Walter; Wolff, David; Krajewski, Witek; Gatlin, Patrick

    2015-01-01

    The Global Precipitation Measurement (GPM) Mission Iowa Flood Studies (IFloodS) campaign was conducted in central and northeastern Iowa during the months of April-June, 2013. Specific science objectives for IFloodS included quantification of uncertainties in satellite and ground-based estimates of precipitation, 4-D characterization of precipitation physical processes and associated parameters (e.g., size distributions, water contents, types, structure etc.), assessment of the impact of precipitation estimation uncertainty and physical processes on hydrologic predictive skill, and refinement of field observations and data analysis approaches as they pertain to future GPM integrated hydrologic validation and related field studies. In addition to field campaign archival of raw and processed satellite data (including precipitation products), key ground-based platforms such as the NASA NPOL S-band and D3R Ka/Ku-band dual-polarimetric radars, University of Iowa X-band dual-polarimetric radars, a large network of paired rain gauge platforms, and a large network of 2D Video and Parsivel disdrometers were deployed. In something of a canonical approach, the radar (NPOL in particular), gauge and disdrometer observational assets were deployed to create a consistent high-quality distributed (time and space sampling) radar-based ground "reference" rainfall dataset, with known uncertainties, that could be used for assessing the satellite-based precipitation products at a range of space/time scales. Subsequently, the impact of uncertainties in the satellite products could be evaluated relative to the ground-benchmark in coupled weather, land-surface and distributed hydrologic modeling frameworks as related to flood prediction. Relative to establishing the ground-based "benchmark", numerous avenues were pursued in the making and verification of IFloodS "reference" dual-polarimetric radar-based rain maps, and this study documents the process and results as they pertain specifically

  6. Polarimetric scattering and SAR information retrieval

    CERN Document Server

    Jin, Ya-Qiu

    2013-01-01

    Taking an innovative look at Synthetic Aperture Radar (SAR), this practical reference fully covers new developments in SAR and its various methodologies and enables readers to interpret SAR imagery An essential reference on polarimetric Synthetic Aperture Radar (SAR), this book uses scattering theory and radiative transfer theory as a basis for its treatment of topics. It is organized to include theoretical scattering models and SAR data analysis techniques, and presents cutting-edge research on theoretical modelling of terrain surface. The book includes quantitative app

  7. A polarimetric survey of symbiotic stars

    International Nuclear Information System (INIS)

    Schulte-Ladbeck, R.E.; Magalhaes, A.M.; Magalhaes, A.M.

    1990-01-01

    We present optical and near-infrared linear polarization observations of 24 symbiotic stars, 14 observed with polarimetry for the first time. In combination with published data, we find that ∼ 50% of the symbiotics observed polarimetrically show evidence for intrinsic polarization. We discuss the results in the light of previous observations and comment on the temporal variability and wavelength dependence of the polarization. Dust scattering is identified as the dominant mechanism producing polarization in symbiotic stars. While we cannot exclude that some symbiotic systems are completely engulfed in their dust shells our data indicate that the Hα emission line may originate from outside of the dust-scattering envelopes in some systems

  8. Wetland Classification for Black Duck Habitat Management Using Combined Polarimetric RADARSAT 2 and SPOT Imagery

    Science.gov (United States)

    Zhang, W.; Hu, B.; Brown, G.

    2018-04-01

    The black duck population has decreased significantly due to loss of its breeding habitat. Wetlands are an important feature that relates to habitat management and requires monitoring. Synthetic Aperture Radar (SAR) systems are helpful to map the wetland as the microwave signals are sensitive to water content and can be used to map surface water extent, saturated soils, and flooded vegetation. In this study, RadarSat 2 Polarimetric data is employed to map surface water and track changes in extent over the years through image thresholding and reviewed different approaches of Polarimetric decompositions for detecting flooded vegetation. Also, object-based analysis associated with beaver activity is conducted with combined multispectral SPOT satellite imagery. Results show SAR data has proven ability to improve mapping open water areas and locate flooded vegetation areas.

  9. Research on visible and near infrared spectral-polarimetric properties of soil polluted by crude oil

    Science.gov (United States)

    Shen, Hui-yan; Zhou, Pu-cheng; Pan, Bang-long

    2017-10-01

    Hydrocarbon contaminated soil can impose detrimental effects on forest health and quality of agricultural products. To manage such consequences, oil leak indicators should be detected quickly by monitoring systems. Remote sensing is one of the most suitable techniques for monitoring systems, especially for areas which are uninhabitable and difficulty to access. The most available physical quantities in optical remote sensing domain are the intensity and spectral information obtained by visible or infrared sensors. However, besides the intensity and wavelength, polarization is another primary physical quantity associated with an optical field. During the course of reflecting light-wave, the surface of soil polluted by crude oil will cause polarimetric properties which are related to the nature of itself. Thus, detection of the spectralpolarimetric properties for soil polluted by crude oil has become a new remote sensing monitoring method. In this paper, the multi-angle spectral-polarimetric instrument was used to obtain multi-angle visible and near infrared spectralpolarimetric characteristic data of soil polluted by crude oil. And then, the change rule between polarimetric properties with different affecting factors, such as viewing zenith angle, incidence zenith angle of the light source, relative azimuth angle, waveband of the detector as well as different grain size of soil were discussed, so as to provide a scientific basis for the research on polarization remote sensing for soil polluted by crude oil.

  10. Polarimetric Remote Sensing of Atmospheric Particulate Pollutants

    Science.gov (United States)

    Li, Z.; Zhang, Y.; Hong, J.

    2018-04-01

    Atmospheric particulate pollutants not only reduce atmospheric visibility, change the energy balance of the troposphere, but also affect human and vegetation health. For monitoring the particulate pollutants, we establish and develop a series of inversion algorithms based on polarimetric remote sensing technology which has unique advantages in dealing with atmospheric particulates. A solution is pointed out to estimate the near surface PM2.5 mass concentrations from full remote sensing measurements including polarimetric, active and infrared remote sensing technologies. It is found that the mean relative error of PM2.5 retrieved by full remote sensing measurements is 35.5 % in the case of October 5th 2013, improved to a certain degree compared to previous studies. A systematic comparison with the ground-based observations further indicates the effectiveness of the inversion algorithm and reliability of results. A new generation of polarized sensors (DPC and PCF), whose observation can support these algorithms, will be onboard GF series satellites and launched by China in the near future.

  11. POLARIMETRIC REMOTE SENSING OF ATMOSPHERIC PARTICULATE POLLUTANTS

    Directory of Open Access Journals (Sweden)

    Z. Li

    2018-04-01

    Full Text Available Atmospheric particulate pollutants not only reduce atmospheric visibility, change the energy balance of the troposphere, but also affect human and vegetation health. For monitoring the particulate pollutants, we establish and develop a series of inversion algorithms based on polarimetric remote sensing technology which has unique advantages in dealing with atmospheric particulates. A solution is pointed out to estimate the near surface PM2.5 mass concentrations from full remote sensing measurements including polarimetric, active and infrared remote sensing technologies. It is found that the mean relative error of PM2.5 retrieved by full remote sensing measurements is 35.5 % in the case of October 5th 2013, improved to a certain degree compared to previous studies. A systematic comparison with the ground-based observations further indicates the effectiveness of the inversion algorithm and reliability of results. A new generation of polarized sensors (DPC and PCF, whose observation can support these algorithms, will be onboard GF series satellites and launched by China in the near future.

  12. Feature-Based Nonlocal Polarimetric SAR Filtering

    Directory of Open Access Journals (Sweden)

    Xiaoli Xing

    2017-10-01

    Full Text Available Polarimetric synthetic aperture radar (PolSAR images are inherently contaminated by multiplicative speckle noise, which complicates the image interpretation and image analyses. To reduce the speckle effect, several adaptive speckle filters have been developed based on the weighted average of the similarity measures commonly depending on the model or probability distribution, which are often affected by the distribution parameters and modeling texture components. In this paper, a novel filtering method introduces the coefficient of variance ( CV and Pauli basis (PB to measure the similarity, and the two features are combined with the framework of the nonlocal mean filtering. The CV is used to describe the complexity of various scenes and distinguish the scene heterogeneity; moreover, the Pauli basis is able to express the polarimetric information in PolSAR image processing. This proposed filtering combines the CV and Pauli basis to improve the estimation accuracy of the similarity weights. Then, the similarity of the features is deduced according to the test statistic. Subsequently, the filtering is proceeded by using the nonlocal weighted estimation. The performance of the proposed filter is tested with the simulated images and real PolSAR images, which are acquired by AIRSAR system and ESAR system. The qualitative and quantitative experiments indicate the validity of the proposed method by comparing with the widely-used despeckling methods.

  13. [Modeling and Simulation of Spectral Polarimetric BRDF].

    Science.gov (United States)

    Ling, Jin-jiang; Li, Gang; Zhang, Ren-bin; Tang, Qian; Ye, Qiu

    2016-01-01

    Under the conditions of the polarized light, The reflective surface of the object is affected by many factors, refractive index, surface roughness, and so the angle of incidence. For the rough surface in the different wavelengths of light exhibit different reflection characteristics of polarization, a spectral polarimetric BRDF based on Kirchhof theory is proposee. The spectral model of complex refraction index is combined with refraction index and extinction coefficient spectral model which were got by using the known complex refraction index at different value. Then get the spectral model of surface roughness derived from the classical surface roughness measuring method combined with the Fresnel reflection function. Take the spectral model of refraction index and roughness into the BRDF model, then the spectral polarimetirc BRDF model is proposed. Compare the simulation results of the refractive index varies with wavelength, roughness is constant, the refraction index and roughness both vary with wavelength and origin model with other papers, it shows that, the spectral polarimetric BRDF model can show the polarization characteristics of the surface accurately, and can provide a reliable basis for the application of polarization remote sensing, and other aspects of the classification of substances.

  14. Assessment of Polarimetric SAR Interferometry for Improving Ship Classification based on Simulated Data

    Directory of Open Access Journals (Sweden)

    Jordi J. Mallorqui

    2008-12-01

    Full Text Available This paper uses a complete and realistic SAR simulation processing chain, GRECOSAR, to study the potentialities of Polarimetric SAR Interferometry (POLInSAR in the development of new classification methods for ships. Its high processing efficiency and scenario flexibility have allowed to develop exhaustive scattering studies. The results have revealed, first, vessels’ geometries can be described by specific combinations of Permanent Polarimetric Scatterers (PePS and, second, each type of vessel could be characterized by a particular spatial and polarimetric distribution of PePS. Such properties have been recently exploited to propose a new Vessel Classification Algorithm (VCA working with POLInSAR data, which, according to several simulation tests, may provide promising performance in real scenarios. Along the paper, explanation of the main steps summarizing the whole research activity carried out with ships and GRECOSAR are provided as well as examples of the main results and VCA validation tests. Special attention will be devoted to the new improvements achieved, which are related to simulations processing a new and highly realistic sea surface model. The paper will show that, for POLInSAR data with fine resolution, VCA can help to classify ships with notable robustness under diverse and adverse observation conditions.

  15. Segmentation of Polarimetric SAR Images Usig Wavelet Transformation and Texture Features

    Science.gov (United States)

    Rezaeian, A.; Homayouni, S.; Safari, A.

    2015-12-01

    Polarimetric Synthetic Aperture Radar (PolSAR) sensors can collect useful observations from earth's surfaces and phenomena for various remote sensing applications, such as land cover mapping, change and target detection. These data can be acquired without the limitations of weather conditions, sun illumination and dust particles. As result, SAR images, and in particular Polarimetric SAR (PolSAR) are powerful tools for various environmental applications. Unlike the optical images, SAR images suffer from the unavoidable speckle, which causes the segmentation of this data difficult. In this paper, we use the wavelet transformation for segmentation of PolSAR images. Our proposed method is based on the multi-resolution analysis of texture features is based on wavelet transformation. Here, we use the information of gray level value and the information of texture. First, we produce coherency or covariance matrices and then generate span image from them. In the next step of proposed method is texture feature extraction from sub-bands is generated from discrete wavelet transform (DWT). Finally, PolSAR image are segmented using clustering methods as fuzzy c-means (FCM) and k-means clustering. We have applied the proposed methodology to full polarimetric SAR images acquired by the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) L-band system, during July, in 2012 over an agricultural area in Winnipeg, Canada.

  16. SEGMENTATION OF POLARIMETRIC SAR IMAGES USIG WAVELET TRANSFORMATION AND TEXTURE FEATURES

    Directory of Open Access Journals (Sweden)

    A. Rezaeian

    2015-12-01

    Full Text Available Polarimetric Synthetic Aperture Radar (PolSAR sensors can collect useful observations from earth’s surfaces and phenomena for various remote sensing applications, such as land cover mapping, change and target detection. These data can be acquired without the limitations of weather conditions, sun illumination and dust particles. As result, SAR images, and in particular Polarimetric SAR (PolSAR are powerful tools for various environmental applications. Unlike the optical images, SAR images suffer from the unavoidable speckle, which causes the segmentation of this data difficult. In this paper, we use the wavelet transformation for segmentation of PolSAR images. Our proposed method is based on the multi-resolution analysis of texture features is based on wavelet transformation. Here, we use the information of gray level value and the information of texture. First, we produce coherency or covariance matrices and then generate span image from them. In the next step of proposed method is texture feature extraction from sub-bands is generated from discrete wavelet transform (DWT. Finally, PolSAR image are segmented using clustering methods as fuzzy c-means (FCM and k-means clustering. We have applied the proposed methodology to full polarimetric SAR images acquired by the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR L-band system, during July, in 2012 over an agricultural area in Winnipeg, Canada.

  17. Detection and Characterization of Circulating Tumour Cells in Multiple Myeloma

    Directory of Open Access Journals (Sweden)

    Liangxuan Zhang

    2016-06-01

    Full Text Available Multiple myeloma (MM remains an incurable disease despite recent therapeutic improvements. The ability to detect and characterize MM circulating tumour cells (CTCs in peripheral blood provides an alternative to replace or augment invasive bone marrow (BM biopsies with a simple blood draw, providing real-time, clinically relevant information leading to improved disease manage‐ ment and therapy selection. Here we have developed and qualified an enrichment-free, cell-based immunofluores‐ cence MM CTC assay that utilizes an automated digital pathology algorithm to distinguish MM CTCs from white blood cells (WBCs on the basis of CD138 and CD45 expression levels, as well as a number of morphological parameters. These MM CTCs were further characterized for expression of phospho-ribosomal protein S6 (pS6 as a readout for PI3K/AKT pathway activation. Clinical feasi‐ bility of the assay was established by testing blood samples from a small cohort of patients, where we detected popu‐ lations of both CD138pos and CD138neg MM CTCs. In this study, we developed an immunofluorescent cell-based assay to detect and characterize CTCs in MM.

  18. Detection and Characterization of Circulating Tumour Cells in Multiple Myeloma

    Directory of Open Access Journals (Sweden)

    Liangxuan Zhang

    2016-01-01

    Full Text Available Multiple myeloma (MM remains an incurable disease despite recent therapeutic improvements. The ability to detect and characterize MM circulating tumour cells (CTCs in peripheral blood provides an alternative to replace or augment invasive bone marrow (BM biopsies with a simple blood draw, providing real-time, clinically relevant information leading to improved disease management and therapy selection. Here we have developed and qualified an enrichment-free, cell-based immunofluorescence MM CTC assay that utilizes an automated digital pathology algorithm to distinguish MM CTCs from white blood cells (WBCs on the basis of CD138 and CD45 expression levels, as well as a number of morphological parameters. These MM CTCs were further characterized for expression of phospho-ribosomal protein S6 (pS6 as a readout for PI3K/AKT pathway activation. Clinical feasibility of the assay was established by testing blood samples from a small cohort of patients, where we detected populations of both CD138 pos and CD138 neg MM CTCs. In this study, we developed an immunofluorescent cell-based assay to detect and characterize CTCs in MM.

  19. NAMMA NASA POLARIMETRIC DOPPLER WEATHER RADAR (NPOL) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The NAMMA NASA Polarimetric Doppler Weather Radar (NPOL) dataset used the NPOL, developed by a research team from Wallops Flight Facility, is a fully transportable...

  20. The effect of orbital eccentricity on polarimetric binary diagnostics

    International Nuclear Information System (INIS)

    Aspin, C.; Brown, J.C.; Simmons, J.F.L.

    1980-01-01

    The polarimetric variation from a binary system with an eccentric orbit, thus non-corotating, are calculated and the effect on determining the system parameters is discussed, relative to the circular case. (Auth.)

  1. Characterizing neuropathic pain profiles: enriching interpretation of painDETECT

    Directory of Open Access Journals (Sweden)

    Cappelleri JC

    2016-07-01

    Full Text Available Joseph C Cappelleri,1 Vijaya Koduru,2 E Jay Bienen,3 Alesia Sadosky4 1Pfizer Inc, Groton, CT, USA; 2Eliassen Group, New London, CT, USA; 3Outcomes Research Consultant, New York, NY, USA; 4Pfizer Inc, New York, NY, USA Purpose: To psychometrically evaluate painDETECT, a patient-reported screening questionnaire for neuropathic pain (NeP, for discriminating among sensory pain symptoms (burning, tingling/prickling, light touching, sudden pain attacks/electric shock-type pain, cold/heat, numbness, and slight pressure. Methods: The seven-item version of painDETECT provides an overall score that targets only sensory symptoms, while the nine-item version adds responses on two items to the overall score, covering pain course pattern and pain radiation. Both versions have relevance in terms of characterizing broad NeP. The nine- and seven-item versions of painDETECT were administered to subjects with confirmed NeP across six conditions identified during office visits to US community-based physicians. Responses on the sensory symptom items were dichotomized into “at least moderate” (ie, moderate, strongly, very strongly relative to the combined other responses (never, hardly noticed, slightly. Logistic regression of dichotomized variables on the total painDETECT score provided probabilities of experiencing each symptom across the range of painDETECT scores. Results: Both painDETECT versions discriminated among the symptoms with similar probabilities across the score ranges. Using these data, the probability of moderately experiencing each pain sensory item was estimated for a particular score, providing a pain profile. Additionally, the likelihood of experiencing each sensation was determined for a discrete increase in score, ie, the odds of at least a moderate sensation of burning (versus less than a moderate sensation was 1.29 for a 1-point increase, 3.52 for a 5-point increase, and 12.42 for every 10-point increase in the nine-item painDETECT score

  2. Pulse-based internal calibration of polarimetric SAR

    DEFF Research Database (Denmark)

    Dall, Jørgen; Skou, Niels; Christensen, Erik Lintz

    1994-01-01

    Internal calibration greatly diminishes the dependence on calibration target deployment compared to external calibration. Therefore the Electromagnetics Institute (EMI) at the Technical University of Denmark (TUD) has equipped its polarimetric SAR, EMISAR, with several calibration loops and devel......Internal calibration greatly diminishes the dependence on calibration target deployment compared to external calibration. Therefore the Electromagnetics Institute (EMI) at the Technical University of Denmark (TUD) has equipped its polarimetric SAR, EMISAR, with several calibration loops...

  3. Rapid Detection and Characterization of Emerging Foreign Animal Disease Pathogens

    Energy Technology Data Exchange (ETDEWEB)

    Jaing, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-11-18

    To best safeguard human and animal health requires early detection and characterization of disease events. This must include effective surveillance for emerging infectious diseases. Both deliberate and natural outbreaks have enormous economic and public health impacts, and can present serious threats to national security. In this project, we developed novel next generation detection technologies to protect the agricultural economy and biosecurity. The first technology is a multiplexed assay to simultaneously detection 10 swine viral and bacterial pathogens. The second one is the Lawrence Livermore Microbial Detection Array (LLMDA) which can detect more than 10,000 microbial species including 4219 viruses, 5367 bacteria, 265 fungi, 117 protozoa and 293 archaea. We analyzed a series of swine clinical samples from past disease events to demonstrate the utility of the assays for faster and cheaper detection of emerging and foreign animal disease pathogens, and their utility as s routine diagnosis and surveillance tool. A second goal of the study is to better understand mechanisms of African swine fever virus (ASFV) infection in pigs to aid the development of countermeasures and diagnostics. There is no vaccine available for ASF. ASF outbreak is on the rise on several European countries. Though ASF is not currently in the U.S., a potential outbreak in the U.S. would be detrimental to the swine industry and the US agricultural economy. We pursued a genome-wide approach to characterize the pig immune responses after ASFV infection. We used RNA sequencing and bioinformatics methods to identify genes and pathways that are affected during ASF infection. We have identified a list of most differentially expressed genes that are in the immune response pathways.

  4. [Role of MRI for detection and characterization of pulmonary nodules].

    Science.gov (United States)

    Sommer, G; Koenigkam-Santos, M; Biederer, J; Puderbach, M

    2014-05-01

    Due to physical and technical limitations, magnetic resonance imaging (MRI) has hitherto played only a minor role in image-based diagnostics of the lungs. However, as a consequence of important methodological developments during recent years, MRI has developed into a technically mature and clinically well-proven method for specific pulmonary questions. The purpose of this article is to provide an overview on the currently available sequences and techniques for assessment of pulmonary nodules and analyzes the clinical significance according to the current literature. The main focus is on the detection of lung metastases, the detection of primary pulmonary malignancies in high-risk individuals and the differentiation between pulmonary nodules of benign and malignant character. The MRI technique has a sensitivity of approximately 80 % for detection of malignant pulmonary nodules compared to the reference standard low-dose computed tomography (CT) and is thus somewhat inferior to CT. Advantages of MRI on the other hand are a higher specificity in differentiating malignant and benign pulmonary nodules and the absence of ionizing radiation exposure. A systematic use of MRI as a primary tool for detection and characterization of pulmonary nodules is currently not recommended due to insufficient data. The diagnostic potential of MRI for early detection and staging of malignant pulmonary diseases, however, seems promising. Therefore, further evaluation of MRI as a secondary imaging modality in clinical trials is highly warranted.

  5. Polarimetric survey of main-belt asteroids. V. The unusual polarimetric behavior of V-type asteroids

    Science.gov (United States)

    Gil-Hutton, R.; López-Sisterna, C.; Calandra, M. F.

    2017-03-01

    Aims: We present the results of a polarimetric survey of main-belt asteroids at Complejo Astronómico El Leoncito (CASLEO), San Juan, Argentina. The aims of this survey are to increase the database of asteroid polarimetry, to estimate diversity in polarimetric properties of asteroids that belong to different taxonomic classes, and to search for objects that exhibit anomalous polarimetric properties. Methods: The data were obtained using the CASPROF and CASPOL polarimeters at the 2.15 m telescope. The CASPROF polarimeter is a two-hole aperture polarimeter with rapid modulation and CASPOL is a polarimeter based on a CCD detector, which allows us to observe fainter objects with better signal-to-noise ratio. Results: The survey began in 1995 and data on a large sample of asteroids were obtained until 2012. A second period began in 2013 using a polarimeter with a more sensitive detector in order to study small asteroids, families, and special taxonomic groups. We obtained 55 polarimetric measurements for 28 V-type main belt asteroids, all of them polarimetrically observed for the first time. The data obtained in this survey let us find polarimetric parameters for (1459) Magnya and for a group of 11 small V-type objects with similar polarimetric behavior. These polarization curves are unusual since they show a shallow minimum and a small inversion angle in comparison with (4) Vesta, although they have a steeper slope at α0. This polarimetric behavior could be explained by differences in the regoliths of these asteroids. The observations of (2579) Spartacus, and perhaps also (3944) Halliday, indicate a inversion angle larger than 24-25°. Based on observations carried out at the Complejo Astronómico El Leoncito, operated under agreement between the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina and the National Universities of La Plata, Córdoba, and San Juan.

  6. Rice status and microwave characteristics: Analysis of rice paddy fields at Kojima Bay [Okayama, Japan] using multi-frequency and polarimetric Pi-SAR radar data images

    International Nuclear Information System (INIS)

    Ishitsuka, N.; Saito, G.; Ouchi, K.; Davidson, G.; Mohri, K.; Uratsuka, S.

    2003-01-01

    just before harvest, L-band polarimetric data can detect various rice statuses such as standing, inclining, or lying. We conclude that multi band and fully polarimetric SAR data can quantity detect crop growth, as do optical sensors in all weather conditions

  7. On the Use of Generalized Volume Scattering Models for the Improvement of General Polarimetric Model-Based Decomposition

    Directory of Open Access Journals (Sweden)

    Qinghua Xie

    2017-01-01

    Full Text Available Recently, a general polarimetric model-based decomposition framework was proposed by Chen et al., which addresses several well-known limitations in previous decomposition methods and implements a simultaneous full-parameter inversion by using complete polarimetric information. However, it only employs four typical models to characterize the volume scattering component, which limits the parameter inversion performance. To overcome this issue, this paper presents two general polarimetric model-based decomposition methods by incorporating the generalized volume scattering model (GVSM or simplified adaptive volume scattering model, (SAVSM proposed by Antropov et al. and Huang et al., respectively, into the general decomposition framework proposed by Chen et al. By doing so, the final volume coherency matrix structure is selected from a wide range of volume scattering models within a continuous interval according to the data itself without adding unknowns. Moreover, the new approaches rely on one nonlinear optimization stage instead of four as in the previous method proposed by Chen et al. In addition, the parameter inversion procedure adopts the modified algorithm proposed by Xie et al. which leads to higher accuracy and more physically reliable output parameters. A number of Monte Carlo simulations of polarimetric synthetic aperture radar (PolSAR data are carried out and show that the proposed method with GVSM yields an overall improvement in the final accuracy of estimated parameters and outperforms both the version using SAVSM and the original approach. In addition, C-band Radarsat-2 and L-band AIRSAR fully polarimetric images over the San Francisco region are also used for testing purposes. A detailed comparison and analysis of decomposition results over different land-cover types are conducted. According to this study, the use of general decomposition models leads to a more accurate quantitative retrieval of target parameters. However, there

  8. Classification and Monitoring of Reed Belts Using Dual-Polarimetric TerraSAR-X Time Series

    Directory of Open Access Journals (Sweden)

    Iris Heine

    2016-06-01

    Full Text Available Synthetic aperture radar polarimetry (PolSAR and polarimetric decomposition techniques have proven to be useful tools for wetland mapping. In this study we classify reed belts and monitor their phenological changes at a natural lake in northeastern Germany using dual-co-polarized (HH, VV TerraSAR-X time series. The time series comprises 19 images, acquired between August 2014 and May 2015, in ascending and descending orbit. We calculated different polarimetric indices using the HH and VV intensities, the dual-polarimetric coherency matrix including dominant and mean alpha scattering angles, and entropy and anisotropy (normalized eigenvalue difference as well as combinations of entropy and anisotropy for the analysis of the scattering scenarios. The image classifications were performed with the random forest classifier and validated with high-resolution digital orthophotos. The time series analysis of the reed belts revealed significant seasonal changes for the double-bounce–sensitive parameters (intensity ratio HH/VV and intensity difference HH-VV, the co-polarimetric coherence phase and the dominant and mean alpha scattering angles and in the dual-polarimetric coherence (amplitude, anisotropy, entropy, and anisotropy-entropy combinations; whereas in summer dense leaves cause volume scattering, in winter, after leaves have fallen, the reed stems cause predominately double-bounce scattering. Our study showed that the five most important parameters for the classification of reed are the intensity difference HH-VV, the mean alpha scattering angle, intensity ratio HH/VV, and the coherence (phase. Due to the better separation of reed and other vegetation (deciduous forest, coniferous forest, meadow, winter acquisitions are preferred for the mapping of reed. Multi-temporal stacks of winter images performed better than summer ones. The combination of ascending and descending images also improved the result as it reduces the influence of the sensor

  9. System for tissue characterization using synchronous detection of diffuse reflectance

    International Nuclear Information System (INIS)

    Morales Lopez, Orestes M.; Stolik Isakina, Suren; La Rosa Vazquez, Jose Manuel de; Valor Reed, Alma

    2016-01-01

    The development of a system for the characterization of tissues optical properties in-vivo by synchronous detection of diffuse reflectance is presented. The system comprises an exploring probe with a linear spatial arrangement of optical fibers coupled to six lasers of 650 nm wavelength and a photodiode. The system also includes a preamplifier circuit for the photodiode, a driver for the amplitude modulation of the light signal of the lasers with optical power monitoring, a digital phase splitter for reference signal generation, an amplifying circuit with digitally switch able gain, a double phase demodulation circuit, an Arduino, and a control interface developed in LabVIEW. (Author)

  10. Adnexal masses literature review, detection, characterization and radiological staging

    International Nuclear Information System (INIS)

    Quesada Gonzalez, Diana

    2011-01-01

    A literature review was conducted on radiological detection and characterization of major adnexal masses identified in ultrasound, computerized axial tomography and magnetic resonance. The characteristics, and incidence findings have been identified in imaging methods of benign adnexal masses and most common ovarian neoplasms. The proposed new classification of adnexal masses GI-RADS has been released. The report of adnexal ultrasound images were classified into 5 categories. They have relied on morphological findings and the likelihood of benignity or malignancy, in addition to the radiological staging submit. The purpose has been simplifying the diagnosis and better therapeutic for the patient behavior [es

  11. Heterogeneity Measurement Based on Distance Measure for Polarimetric SAR Data

    Science.gov (United States)

    Xing, Xiaoli; Chen, Qihao; Liu, Xiuguo

    2018-04-01

    To effectively test the scene heterogeneity for polarimetric synthetic aperture radar (PolSAR) data, in this paper, the distance measure is introduced by utilizing the similarity between the sample and pixels. Moreover, given the influence of the distribution and modeling texture, the K distance measure is deduced according to the Wishart distance measure. Specifically, the average of the pixels in the local window replaces the class center coherency or covariance matrix. The Wishart and K distance measure are calculated between the average matrix and the pixels. Then, the ratio of the standard deviation to the mean is established for the Wishart and K distance measure, and the two features are defined and applied to reflect the complexity of the scene. The proposed heterogeneity measure is proceeded by integrating the two features using the Pauli basis. The experiments conducted on the single-look and multilook PolSAR data demonstrate the effectiveness of the proposed method for the detection of the scene heterogeneity.

  12. Simultaneous Differential Polarimetric Measurements and Co-Polar Correlation Coefficient Measurement

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A polarimetric Doppler weather radar system which allows measurement of linear orthogonal polarimetric variables without a switch by using simultaneous transmission...

  13. Geomorphological mapping of ice-free areas using polarimetric RADARSAT-2 data on Fildes Peninsula and Ardley Island, Antarctica

    Science.gov (United States)

    Schmid, T.; López-Martínez, J.; Guillaso, S.; Serrano, E.; D'Hondt, O.; Koch, M.; Nieto, A.; O'Neill, T.; Mink, S.; Durán, J. J.; Maestro, A.

    2017-09-01

    Satellite-borne Synthetic Aperture Radar (SAR) has been used for characterizing and mapping in two relevant ice-free areas in the South Shetland Islands. The objective has been to identify and characterize land surface covers that mainly include periglacial and glacial landforms, using fully polarimetric SAR C band RADARSAT-2 data, on Fildes Peninsula that forms part of King George Island, and Ardley Island. Polarimetric parameters obtained from the SAR data, a selection of field based training and validation sites and a supervised classification approach, using the support vector machine were chosen to determine the spatial distribution of the different landforms. Eight periglacial and glacial landforms were characterized according to their scattering mechanisms using a set of 48 polarimetric parameters. The mapping of the most representative surface covers included colluvial deposits, stone fields and pavements, patterned ground, glacial till and rock outcrops, lakes and glacier ice. The overall accuracy of the results was estimated at 81%, a significant value when mapping areas that are within isolated regions where access is limited. Periglacial surface covers such as stone fields and pavements occupy 25% and patterned ground over 20% of the ice-free areas. These are results that form the basis for an extensive monitoring of the ice-free areas throughout the northern Antarctic Peninsula region.

  14. Characterization of binary string statistics for syntactic landmine detection

    Science.gov (United States)

    Nasif, Ahmed O.; Mark, Brian L.; Hintz, Kenneth J.

    2011-06-01

    Syntactic landmine detection has been proposed to detect and classify non-metallic landmines using ground penetrating radar (GPR). In this approach, the GPR return is processed to extract characteristic binary strings for landmine and clutter discrimination. In our previous work, we discussed the preprocessing methodology by which the amplitude information of the GPR A-scan signal can be effectively converted into binary strings, which identify the impedance discontinuities in the signal. In this work, we study the statistical properties of the binary string space. In particular, we develop a Markov chain model to characterize the observed bit sequence of the binary strings. The state is defined as the number of consecutive zeros between two ones in the binarized A-scans. Since the strings are highly sparse (the number of zeros is much greater than the number of ones), defining the state this way leads to fewer number of states compared to the case where each bit is defined as a state. The number of total states is further reduced by quantizing the number of consecutive zeros. In order to identify the correct order of the Markov model, the mean square difference (MSD) between the transition matrices of mine strings and non-mine strings is calculated up to order four using training data. The results show that order one or two maximizes this MSD. The specification of the transition probabilities of the chain can be used to compute the likelihood of any given string. Such a model can be used to identify characteristic landmine strings during the training phase. These developments on modeling and characterizing the string statistics can potentially be part of a real-time landmine detection algorithm that identifies landmine and clutter in an adaptive fashion.

  15. Detection and characterization of buried lunar craters with GRAIL data

    Science.gov (United States)

    Sood, Rohan; Chappaz, Loic; Melosh, Henry J.; Howell, Kathleen C.; Milbury, Colleen; Blair, David M.; Zuber, Maria T.

    2017-06-01

    We used gravity mapping observations from NASA's Gravity Recovery and Interior Laboratory (GRAIL) to detect, characterize and validate the presence of large impact craters buried beneath the lunar maria. In this paper we focus on two prominent anomalies detected in the GRAIL data using the gravity gradiometry technique. Our detection strategy is applied to both free-air and Bouguer gravity field observations to identify gravitational signatures that are similar to those observed over buried craters. The presence of buried craters is further supported by individual analysis of regional free-air gravity anomalies, Bouguer gravity anomaly maps, and forward modeling. Our best candidate, for which we propose the informal name of Earhart Crater, is approximately 200 km in diameter and forms part of the northwestern rim of Lacus Somniorum, The other candidate, for which we propose the informal name of Ashoka Anomaly, is approximately 160 km in diameter and lies completely buried beneath Mare Tranquillitatis. Other large, still unrecognized, craters undoubtedly underlie other portions of the Moon's vast mare lavas.

  16. [Modeling polarimetric BRDF of leaves surfaces].

    Science.gov (United States)

    Xie, Dong-Hui; Wang, Pei-Juan; Zhu, Qi-Jiang; Zhou, Hong-Min

    2010-12-01

    The purpose of the present paper is to model a physical polarimetric bidirectional reflectance distribution function (pBRDF), which can character not only the non-Lambertian but also the polarized features in order that the pBRDF can be applied to analyze the relationship between the degree of polarization and the physiological and biochemical parameters of leaves quantitatively later. Firstly, the bidirectional polarized reflectance distributions from several leaves surfaces were measured by the polarized goniometer developed by Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences. The samples of leaves include two pieces of zea mays L. leaves (young leaf and mature leaf) and a piece of E. palcherrima wild leaf. Non-Lambertian characteristics of directional reflectance from the surfaces of these three leaves are obvious. A Cook-Torrance model was modified by coupling the polarized Fresnel equations to simulate the bidirectional polarized reflectance properties of leaves surfaces. The three parameters in the modified pBRDF model, such as diffuse reflectivity, refractive index and roughness of leaf surface were inversed with genetic algorithm (GA). It was found that the pBRDF model can fit with the measured data well. In addition, these parameters in the model are related with both the physiological and biochemical properties and the polarized characteristics of leaves, therefore it is possible to build the relationships between them later.

  17. The classification of ambiguity in polarimetric reconstruction of coronal mass ejection

    International Nuclear Information System (INIS)

    Dai, Xinghua; Wang, Huaning; Huang, Xin; Du, Zhanle; He, Han

    2014-01-01

    The Thomson scattering theory indicates that there exist explicit and implicit ambiguities in polarimetric analyses of coronal mass ejection (CME) observations. We suggest a classification for these ambiguities in CME reconstruction. Three samples, including double explicit, mixed, and double implicit ambiguity, are shown with the polarimetric analyses of STEREO CME observations. These samples demonstrate that this classification is helpful for improving polarimetric reconstruction.

  18. Polarimetric C-Band SAR Observations of Sea Ice in the Greenland Sea

    DEFF Research Database (Denmark)

    Thomsen, Bjørn Bavnehøj; Nghiem, S.V.; Kwok, R.

    1998-01-01

    The fully polarimetric EMISAR acquired C-band radar signatures of sea ice in the Greenland Sea during a campaign in March 1995. The authors present maps of polarimetric signatures over an area containing various kinds of ice and discuss the use of polarimetric SAR for identification of ice types...

  19. Laboratory Measurements of Single-Particle Polarimetric Spectrum

    Science.gov (United States)

    Gritsevich, M.; Penttila, A.; Maconi, G.; Kassamakov, I.; Helander, P.; Puranen, T.; Salmi, A.; Hæggström, E.; Muinonen, K.

    2017-12-01

    Measuring scattering properties of different targets is important for material characterization, remote sensing applications, and for verifying theoretical results. Furthermore, there are usually simplifications made when we model targets and compute the scattering properties, e.g., ideal shape or constant optical parameters throughout the target material. Experimental studies help in understanding the link between the observed properties and computed results. Experimentally derived Mueller matrices of studied particles can be used as input for larger-scale scattering simulations, e.g., radiative transfer computations. This method allows to bypass the problem of using an idealized model for single-particle optical properties. While existing approaches offer ensemble- and orientation-averaged particle properties, our aim is to measure individual particles with controlled or known orientation. With the newly developed scatterometer, we aim to offer novel possibility to measure single, small (down to μm-scale) targets and their polarimetric spectra. This work presents an experimental setup that measures light scattered by a fixed small particle with dimensions ranging between micrometer and millimeter sizes. The goal of our setup is nondestructive characterization of such particles by measuring light of multiple wavelengths scattered in 360° in a horizontal plane by an ultrasonically levitating sample, whilst simultaneously controlling its 3D position and orientation. We describe the principles and design of our instrument and its calibration. We also present example measurements of real samples. This study was conducted under the support from the European Research Council, in the frame of the Advanced Grant project No. 320773 `Scattering and Absorption of Electromagnetic Waves in Particulate Media' (SAEMPL).

  20. Developing Lightning Prediction Tools for the CCAFS Dual-Polarimetric Radar

    Science.gov (United States)

    Petersen, W. A.; Carey, L. D.; Deierling, W.; Johnson, E.; Bateman, M.

    2009-01-01

    ensuing lightning in the sub-tropical/tropical convection typical of the southeastern U.S., Maritime Continent, and southwestern Amazon. The polarimetric signatures detected in this setting provide a basis for automated 3-D detection of hydrometeor types in fuzzy logic hydrometeor identification algorithms (HID). Our working hypothesis is that improvement in lightning onset warning lead time and specificity for a given storm, relative to application of a Z-threshold algorithm, should arise as a consequence of the ability of dual-polarimetric radar to unambiguously detect and identify (through HID algorithms) the updraft elevation of rain-water cores above the freezing level and subsequent onset of drop freezing, riming, and robust mixed phase processes leading to significant charge separation and lightning. This type of algorithm, though dependent on the quality of the polarimetric data should be less susceptible to variable Z-calibration that can impact a given Z-threshold approach. To facilitate development of the algorithm while the 45WS dual-pol radar is in its current test stages and to evaluate the impact of polarimetric data quality (e.g., modified scan parameters and sampling) on the ensuing algorithms, we are using the ARMOR C-band dual-pol radar in Huntsville combined with N. Alabama LMA data and ARMOR HID algorithms [NCAR algorithm modified for application at C-band] in a testbed fashion. For lightning cessation we are revisiting the application of differential propagation phase variables for the monitoring of ice crystal alignment driven by in-cloud electric fields combined with metrics of ice water path (i.e., vertically integrated reflectivity). Importantly it should be noted that this approach is still very much a research topic and as such, we will explore operational applications that involve radar frequencies other than C-Band by using the UAH MAX X-band dual-pol radar in slow staring modes.

  1. Detecting and characterizing unroofed caves by ground penetrating radar

    Science.gov (United States)

    Čeru, Teja; Šegina, Ela; Knez, Martin; Benac, Čedomir; Gosar, Andrej

    2018-02-01

    The bare karst surface in the southeastern part of Krk Island (Croatia) is characterized by different surface karst features, such as valley-like shallow linear depressions and partially or fully sediment-filled depressions of various shapes and sizes. They were noticed due to locally increased thickness of sediment and enhanced vegetation but had not yet been systematically studied and defined. Considering only the geometry of the investigated surface features and the rare traces of cave environments detected by field surveys, it was unclear which processes (surface karstification and/or speleogenesis) contributed most to their formation. The low-frequency ground penetrating radar (GPR) method using a special 50 MHz RTA antenna was applied to study and describe these karst features. Three study sites were chosen and 5 km of GPR profiles were positioned to include various surface features. The results obtained from the GPR investigation lead to the following conclusions: (1) an increased thickness of sediment was detected in all the investigated depressions indicating their considerable depth; (2) areas between different depressions expressed as attenuated zones in GPR images reveal their interconnection; (3) transitions between surface and underground features are characterized by a collapsed passage visible in the GPR data; and (4) an underground continuation of surface valley-like depressions was detected, proving the speleogenetic origin of such features. Subsurface information obtained using GPR indicates that the valley-like depressions, irregular depressions completely or partially filled with sediment, and some dolines are associated with a nearly 4 km-long unroofed cave and developed as a result of karst denudation. In the regional context, these results suggest long-lasting karstification processes in the area, in contrast to the pre-karstic fluvial phase previously assumed to have occurred here. This research is the first application of the GPR method to

  2. Boiling anomaly detection by various signal characterization methods

    International Nuclear Information System (INIS)

    Sakuma, M.; Kozma, R.; Kitamura, M.; Schoonewelle, H.; Hoogenboom, J.E.

    1996-01-01

    In order to detect anomalies in the early stage for complex dynamical systems like nuclear power plants, it is important to characterize various statistical features of the data acquired in normal operating condition. In this paper, concept of hierarchical anomaly monitoring method is outlined, which is based on the diversification principle. In addition to usual time and frequency domain analysis (FFT, APDF, MAR-SPRT), other analysis (wavelet, fractal, etc.) are performed. As soon as any inconsistency arises in the results of the analysis on the upper level, a thorough analysis is initiated. A comparison among these methods is performed and the efficiency of the diversification approach has been demonstrated through simulated boiling anomalies in nuclear reactors. (authors)

  3. Molecular diagnostics for the detection and characterization of microbial pathogens.

    Science.gov (United States)

    Procop, Gary W

    2007-09-01

    New and advanced methods of molecular diagnostics are changing the way we practice clinical microbiology, which affects the practice of medicine. Signal amplification and real-time nucleic acid amplification technologies offer a sensitive and specific result with a more rapid turnaround time than has ever before been possible. Numerous methods of postamplification analysis afford the simultaneous detection and differentiation of numerous microbial pathogens, their mechanisms of resistance, and the construction of disease-specific assays. The technical feasibility of these assays has already been demonstrated. How these new, often more expensive tests will be incorporated into routine practice and the impact they will have on patient care remain to be determined. One of the most attractive uses for such techniques is to achieve a more rapid characterization of the infectious agent so that a narrower-spectrum antimicrobial agent may be used, which should have an impact on resistance patterns.

  4. Initial assessment of an airborne Ku-band polarimetric SAR.

    Energy Technology Data Exchange (ETDEWEB)

    Raynal, Ann Marie; Doerry, Armin Walter

    2013-02-01

    Polarimetric synthetic aperture radar (SAR) has been used for a variety of dual-use research applications since the 1940s. By measuring the direction of the electric field vector from radar echoes, polarimetry may enhance an analysts understanding of scattering effects for both earth monitoring and tactical surveillance missions. Polarimetry may provide insight into surface types, materials, or orientations for natural and man-made targets. Polarimetric measurements may also be used to enhance the contrast between scattering surfaces such as man-made objects and their surroundings. This report represents an initial assessment of the utility of, and applications for, polarimetric SAR at Ku-band for airborne or unmanned aerial systems.

  5. Knowledge-based sea ice classification by polarimetric SAR

    DEFF Research Database (Denmark)

    Skriver, Henning; Dierking, Wolfgang

    2004-01-01

    Polarimetric SAR images acquired at C- and L-band over sea ice in the Greenland Sea, Baltic Sea, and Beaufort Sea have been analysed with respect to their potential for ice type classification. The polarimetric data were gathered by the Danish EMISAR and the US AIRSAR which both are airborne...... systems. A hierarchical classification scheme was chosen for sea ice because our knowledge about magnitudes, variations, and dependences of sea ice signatures can be directly considered. The optimal sequence of classification rules and the rules themselves depend on the ice conditions/regimes. The use...... of the polarimetric phase information improves the classification only in the case of thin ice types but is not necessary for thicker ice (above about 30 cm thickness)...

  6. Polarimetric SAR interferometry applied to land ice: modeling

    DEFF Research Database (Denmark)

    Dall, Jørgen; Papathanassiou, Konstantinos; Skriver, Henning

    2004-01-01

    This paper introduces a few simple scattering models intended for the application of polarimetric SAR interfer-ometry to land ice. The principal aim is to eliminate the penetration bias hampering ice sheet elevation maps generated with single-channel SAR interferometry. The polarimetric coherent...... scattering models are similar to the oriented-volume model and the random-volume-over-ground model used in vegetation studies, but the ice models are adapted to the different geometry of land ice. Also, due to compaction, land ice is not uniform; a fact that must be taken into account for large penetration...... depths. The validity of the scattering models is examined using L-band polarimetric interferometric SAR data acquired with the EMISAR system over an ice cap located in the percolation zone of the Greenland ice sheet. Radar reflectors were deployed on the ice surface prior to the data acquisition in order...

  7. Identification of hydrometeor mixtures in polarimetric radar measurements and their linear de-mixing

    Science.gov (United States)

    Besic, Nikola; Ventura, Jordi Figueras i.; Grazioli, Jacopo; Gabella, Marco; Germann, Urs; Berne, Alexis

    2017-04-01

    The issue of hydrometeor mixtures affects radar sampling volumes without a clear dominant hydrometeor type. Containing a number of different hydrometeor types which significantly contribute to the polarimetric variables, these volumes are likely to occur in the vicinity of the melting layer and mainly, at large distance from a given radar. Motivated by potential benefits for both quantitative and qualitative applications of dual-pol radar, we propose a method for the identification of hydrometeor mixtures and their subsequent linear de-mixing. This method is intrinsically related to our recently proposed semi-supervised approach for hydrometeor classification. The mentioned classification approach [1] performs labeling of radar sampling volumes by using as a criterion the Euclidean distance with respect to five-dimensional centroids, depicting nine hydrometeor classes. The positions of the centroids in the space formed by four radar moments and one external parameter (phase indicator), are derived through a technique of k-medoids clustering, applied on a selected representative set of radar observations, and coupled with statistical testing which introduces the assumed microphysical properties of the different hydrometeor types. Aside from a hydrometeor type label, each radar sampling volume is characterized by an entropy estimate, indicating the uncertainty of the classification. Here, we revisit the concept of entropy presented in [1], in order to emphasize its presumed potential for the identification of hydrometeor mixtures. The calculation of entropy is based on the estimate of the probability (pi ) that the observation corresponds to the hydrometeor type i (i = 1,ṡṡṡ9) . The probability is derived from the Euclidean distance (di ) of the observation to the centroid characterizing the hydrometeor type i . The parametrization of the d → p transform is conducted in a controlled environment, using synthetic polarimetric radar datasets. It ensures balanced

  8. Detection and characterization of hepatitis A virus circulating in Egypt.

    Science.gov (United States)

    Hamza, Hazem; Abd-Elshafy, Dina Nadeem; Fayed, Sayed A; Bahgat, Mahmoud Mohamed; El-Esnawy, Nagwa Abass; Abdel-Mobdy, Emam

    2017-07-01

    Hepatitis A virus (HAV) still poses a considerable problem worldwide. In the current study, hepatitis A virus was recovered from wastewater samples collected from three wastewater treatment plants over one year. Using RT-PCR, HAV was detected in 43 out of 68 samples (63.2%) representing both inlet and outlet. Eleven positive samples were subjected to sequencing targeting the VP1-2A junction region. Phylogenetic analysis revealed that all samples belonged to subgenotype IB with few substitutions at the amino acid level. The complete sequence of one isolate (HAV/Egy/BI-11/2015) showed that the similarity at the amino acid level was not reflected at the nucleotide level. However, the deduced amino acid sequence derived from the complete nucleotide sequence showed distinct substitutions in the 2B, 2C, and 3A regions. Recombination analysis revealed a recombination event between X75215 (subgenotype IA) and AF268396 (subgenotype IB) involving a portion of the 2B nonstructural protein coding region (nucleotides 3757-3868) assuming the herein characterized sequence an actual recombinant. Despite the role of recombination in picornaviruses evolution, its involvement in HAV evolution has rarely been reported, and this may be due to the limited available complete HAV sequences. To our knowledge, this represents the first characterized complete sequence of an Egyptian isolate and the described recombination event provides an important update on the circulating HAV strains in Egypt.

  9. A structural framework for anomalous change detection and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Lakshman [Los Alamos National Laboratory; Theiler, James P [Los Alamos National Laboratory

    2009-01-01

    We present a spatially adaptive scheme for automatically searching a pair of images of a scene for unusual and interesting changes. Our motivation is to bring into play structural aspects of image features alongside the spectral attributes used for anomalous change detection (ACD). We leverage a small but informative subset of pixels, namely edge pixels of the images, as anchor points of a Delaunay triangulation to jointly decompose the images into a set of triangular regions, called trixels, which are spectrally uniform. Such decomposition helps in image regularization by simple-function approximation on a feature-adaptive grid. Applying ACD to this trixel grid instead of pixels offers several advantages. It allows: (1) edge-preserving smoothing of images, (2) speed-up of spatial computations by significantly reducing the representation of the images, and (3) the easy recovery of structure of the detected anomalous changes by associating anomalous trixels with polygonal image features. The latter facility further enables the application of shape-theoretic criteria and algorithms to characterize the changes and recognize them as interesting or not. This incorporation of spatial information has the potential to filter out some spurious changes, such as due to parallax, shadows, and misregistration, by identifying and filtering out those that are structurally similar and spatially pervasive. Our framework supports the joint spatial and spectral analysis of images, potentially enabling the design of more robust ACD algorithms.

  10. Polarimetric Imaging Of Protoplanetary Disks From The Optical To Sub-Mm

    Science.gov (United States)

    De Boer, Jos; Ménard, F.; Pinte, C.; van der Plas, G.; Snik, F.

    2017-10-01

    To learn how planets form from the smallest building blocks within protoplanetary disks, we first need to know how dust grains grow from micron to mm sizes. Polarimetry across the spectrum has proven to be sensitive to grain properties like dust size distribution and composition and thus can be used to characterize the scattering grains. However, polarization measured with radio interferometric arrays is rarely studied in concert with optical polarimetry. Our team has successfully calibrated the NIR polarimetric imaging mode of VLT/SPHERE, hence upgrading the instrument from a high-contrast imager to a robust tool for quantitative characterization. In this presentation, we will discuss which lessons can be learned by comparing polarimetry in the optical and sub-mm and explore for which science cases both techniques can complement each other. When we combine the polarimetric capabilities of the most advanced optical high-contrast imagers (e.g., Gemini GPI or VLT SPHERE) with that of ALMA we will be able to study the spatial distribution of an extensive range of different grains, which allows us to take an essential step towards a deeper understanding of planet formation.

  11. The Next Generation Airborne Polarimetric Doppler Radar

    Science.gov (United States)

    Vivekanandan, J.; Lee, Wen-Chau; Loew, Eric; Salazar, Jorge; Chandrasekar, V.

    2013-04-01

    NCAR's Electra Doppler radar (ELDORA) with a dual-beam slotted waveguide array using dual-transmitter, dual-beam, rapid scan and step-chirped waveform significantly improved the spatial scale to 300m (Hildebrand et al. 1996). However, ELDORA X-band radar's penetration into precipitation is limited by attenuation and is not designed to collect polarimetric measurements to remotely estimate microphysics. ELDORA has been placed on dormancy because its airborne platform (P3 587) was retired in January 2013. The US research community has strongly voiced the need to continue measurement capability similar to the ELDORA. A critical weather research area is quantitative precipitation estimation/forecasting (QPE/QPF). In recent years, hurricane intensity change involving eye-eyewall interactions has drawn research attention (Montgomery et al., 2006; Bell and Montgomery, 2006). In the case of convective precipitation, two issues, namely, (1) when and where convection will be initiated, and (2) determining the organization and structure of ensuing convection, are key for QPF. Therefore collocated measurements of 3-D winds and precipitation microphysics are required for achieving significant skills in QPF and QPE. Multiple radars in dual-Doppler configuration with polarization capability estimate dynamical and microphysical characteristics of clouds and precipitation are mostly available over land. However, storms over complex terrain, the ocean and in forest regions are not observable by ground-based radars (Bluestein and Wakimoto, 2003). NCAR/EOL is investigating potential configurations for the next generation airborne radar that is capable of retrieving dynamic and microphysical characteristics of clouds and precipitation. ELDORA's slotted waveguide array radar is not compatible for dual-polarization measurements. Therefore, the new design has to address both dual-polarization capability and platform requirements to replace the ELDORA system. NCAR maintains a C-130

  12. Microphysical Structures of Hurricane Irma Observed by Polarimetric Radar

    Science.gov (United States)

    Didlake, A. C.; Kumjian, M. R.

    2017-12-01

    This study examines dual-polarization radar observations of Hurricane Irma as its center passed near the WSR-88D radar in Puerto Rico, capturing needed microphysical information of a mature tropical cyclone. Twenty hours of observations continuously sampled the inner core precipitation features. These data were analyzed by annuli and azimuth, providing a bulk characterization of the primary eyewall, secondary eyewall, and rainbands as they varied around the storm. Polarimetric radar variables displayed distinct signatures of convective and stratiform precipitation in the primary eyewall and rainbands that were organized in a manner consistent with the expected kinematic asymmetry of a storm in weak environmental wind shear but with moderate low-level storm-relative flow. In the front quadrants of the primary eyewall, vertical profiles of differential reflectivity (ZDR) exhibit increasing values with decreasing height consistent with convective precipitation processes. In particular, the front-right quadrant exhibits a signature in reflectivity (ZH) and ZDR indicating larger, sparser drops, which is consistent with a stronger updraft present in this quadrant. In the rear quadrants, a sharply peaked ZDR maximum occurs within the melting layer, which is attributed of stratiform processes. In the rainbands, the convective to stratiform transition can be seen traveling from the front-right to the front-left quadrant. The front-right quadrant exhibits lower co-polar correlation coefficient (ρHV) values in the 3-8 km altitude layer, suggesting larger vertical spreading of various hydrometeors that occurs in convective vertical motions. The front-left quadrant exhibits larger ρHV values, suggesting less diversity of hydrometeor shapes, consistent with stratiform processes. The secondary eyewall did not exhibit a clear signature of processes preferred in a specific quadrant, and a temporal analysis of the secondary eyewall revealed a complex evolution of its structure

  13. COMPARISON BETWEEN SPECTRAL, SPATIAL AND POLARIMETRIC CLASSIFICATION OF URBAN AND PERIURBAN LANDCOVER USING TEMPORAL SENTINEL – 1 IMAGES

    Directory of Open Access Journals (Sweden)

    K. Roychowdhury

    2016-06-01

    Full Text Available Landcover is the easiest detectable indicator of human interventions on land. Urban and peri-urban areas present a complex combination of landcover, which makes classification challenging. This paper assesses the different methods of classifying landcover using dual polarimetric Sentinel-1 data collected during monsoon (July and winter (December months of 2015. Four broad landcover classes such as built up areas, water bodies and wetlands, vegetation and open spaces of Kolkata and its surrounding regions were identified. Polarimetric analyses were conducted on Single Look Complex (SLC data of the region while ground range detected (GRD data were used for spectral and spatial classification. Unsupervised classification by means of K-Means clustering used backscatter values and was able to identify homogenous landcovers over the study area. The results produced an overall accuracy of less than 50% for both the seasons. Higher classification accuracy (around 70% was achieved by adding texture variables as inputs along with the backscatter values. However, the accuracy of classification increased significantly with polarimetric analyses. The overall accuracy was around 80% in Wishart H-A-Alpha unsupervised classification. The method was useful in identifying urban areas due to their double-bounce scattering and vegetated areas, which have more random scattering. Normalized Difference Built-up index (NDBI and Normalized Difference Vegetation Index (NDVI obtained from Landsat 8 data over the study area were used to verify vegetation and urban classes. The study compares the accuracies of different methods of classifying landcover using medium resolution SAR data in a complex urban area and suggests that polarimetric analyses present the most accurate results for urban and suburban areas.

  14. Comparison Between Spectral, Spatial and Polarimetric Classification of Urban and Periurban Landcover Using Temporal Sentinel - 1 Images

    Science.gov (United States)

    Roychowdhury, K.

    2016-06-01

    Landcover is the easiest detectable indicator of human interventions on land. Urban and peri-urban areas present a complex combination of landcover, which makes classification challenging. This paper assesses the different methods of classifying landcover using dual polarimetric Sentinel-1 data collected during monsoon (July) and winter (December) months of 2015. Four broad landcover classes such as built up areas, water bodies and wetlands, vegetation and open spaces of Kolkata and its surrounding regions were identified. Polarimetric analyses were conducted on Single Look Complex (SLC) data of the region while ground range detected (GRD) data were used for spectral and spatial classification. Unsupervised classification by means of K-Means clustering used backscatter values and was able to identify homogenous landcovers over the study area. The results produced an overall accuracy of less than 50% for both the seasons. Higher classification accuracy (around 70%) was achieved by adding texture variables as inputs along with the backscatter values. However, the accuracy of classification increased significantly with polarimetric analyses. The overall accuracy was around 80% in Wishart H-A-Alpha unsupervised classification. The method was useful in identifying urban areas due to their double-bounce scattering and vegetated areas, which have more random scattering. Normalized Difference Built-up index (NDBI) and Normalized Difference Vegetation Index (NDVI) obtained from Landsat 8 data over the study area were used to verify vegetation and urban classes. The study compares the accuracies of different methods of classifying landcover using medium resolution SAR data in a complex urban area and suggests that polarimetric analyses present the most accurate results for urban and suburban areas.

  15. Feature Detection, Characterization and Confirmation Methodology: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Karasaki, Kenzi; Apps, John; Doughty, Christine; Gwatney, Hope; Onishi, Celia Tiemi; Trautz, Robert; Tsang, Chin-Fu

    2007-03-01

    This is the final report of the NUMO-LBNL collaborative project: Feature Detection, Characterization and Confirmation Methodology under NUMO-DOE/LBNL collaboration agreement, the task description of which can be found in the Appendix. We examine site characterization projects from several sites in the world. The list includes Yucca Mountain in the USA, Tono and Horonobe in Japan, AECL in Canada, sites in Sweden, and Olkiluoto in Finland. We identify important geologic features and parameters common to most (or all) sites to provide useful information for future repository siting activity. At first glance, one could question whether there was any commonality among the sites, which are in different rock types at different locations. For example, the planned Yucca Mountain site is a dry repository in unsaturated tuff, whereas the Swedish sites are situated in saturated granite. However, the study concludes that indeed there are a number of important common features and parameters among all the sites--namely, (1) fault properties, (2) fracture-matrix interaction (3) groundwater flux, (4) boundary conditions, and (5) the permeability and porosity of the materials. We list the lessons learned from the Yucca Mountain Project and other site characterization programs. Most programs have by and large been quite successful. Nonetheless, there are definitely 'should-haves' and 'could-haves', or lessons to be learned, in all these programs. Although each site characterization program has some unique aspects, we believe that these crosscutting lessons can be very useful for future site investigations to be conducted in Japan. One of the most common lessons learned is that a repository program should allow for flexibility, in both schedule and approach. We examine field investigation technologies used to collect site characterization data in the field. An extensive list of existing field technologies is presented, with some discussion on usage and limitations

  16. Feature Detection, Characterization and Confirmation Methodology: Final Report

    International Nuclear Information System (INIS)

    Karasaki, Kenzi; Apps, John; Doughty, Christine; Gwatney, Hope; Onishi, Celia Tiemi; Trautz, Robert; Tsang, Chin-Fu

    2007-01-01

    This is the final report of the NUMO-LBNL collaborative project: Feature Detection, Characterization and Confirmation Methodology under NUMO-DOE/LBNL collaboration agreement, the task description of which can be found in the Appendix. We examine site characterization projects from several sites in the world. The list includes Yucca Mountain in the USA, Tono and Horonobe in Japan, AECL in Canada, sites in Sweden, and Olkiluoto in Finland. We identify important geologic features and parameters common to most (or all) sites to provide useful information for future repository siting activity. At first glance, one could question whether there was any commonality among the sites, which are in different rock types at different locations. For example, the planned Yucca Mountain site is a dry repository in unsaturated tuff, whereas the Swedish sites are situated in saturated granite. However, the study concludes that indeed there are a number of important common features and parameters among all the sites--namely, (1) fault properties, (2) fracture-matrix interaction (3) groundwater flux, (4) boundary conditions, and (5) the permeability and porosity of the materials. We list the lessons learned from the Yucca Mountain Project and other site characterization programs. Most programs have by and large been quite successful. Nonetheless, there are definitely 'should-haves' and 'could-haves', or lessons to be learned, in all these programs. Although each site characterization program has some unique aspects, we believe that these crosscutting lessons can be very useful for future site investigations to be conducted in Japan. One of the most common lessons learned is that a repository program should allow for flexibility, in both schedule and approach. We examine field investigation technologies used to collect site characterization data in the field. An extensive list of existing field technologies is presented, with some discussion on usage and limitations. Many of the

  17. Ice sheet anisotropy measured with polarimetric ice sounding radar

    DEFF Research Database (Denmark)

    Dall, Jørgen

    2010-01-01

    For polar ice sheets, valuable stress and strain information can be deduced from crystal orientation fabrics (COF) and their prevailing c-axis alignment. Polarimetric radio echo sounding is a promising technique to measure the anisotropic electromagnetic propagation and reflection properties asso...

  18. Mapping mountain meadow with high resolution and polarimetric SAR data

    International Nuclear Information System (INIS)

    Tian, Bangsen; Li, Zhen; Xu, Juan; Fu, Sitao; Liu, Jiuli

    2014-01-01

    This paper presents a method to map the large grassland in the eastern margin of the Tibetan Plateau with the high resolution polarimetric SAR (PolSAR) imagery. When PolSAR imagery is used for land cover classification, the brightness of a SAR image is affected by topography due to varying projection between ground and image coordinates. The objective of this paper is twofold: (1) we first extend the theory of SAR terrain correction to the polarimetric case, to utilize the entire available polarimetric signature, where correction is performed explicitly based on a matrix format like covariance matrix. (2) Next, the orthoectified PolSAR is applied to classify mountain meadow and investigate the potential of PolSAR in mapping grassland. In this paper, the gamma naught radiometric correction estimates the local illuminated area at each grid point in the radar geometry. Then, each element of the coherency matrix is divided by the local area to produce a polarimetric product. Secondly, the impact of radiometric correction upon classification accuracy is investigated. A supervised classification is performed on the orthorectified Radarsat-2 PolSAR to map the spatial distribution of meadow and evaluate monitoring capabilities of mountain meadow

  19. Reconfigurable digital receiver design and application for instantaneous polarimetric measurement

    NARCIS (Netherlands)

    Wang, Z.; Krasnov, O.A.; Babur, G.P.; Ligthart, L.P.; Van der Zwan, F.

    2011-01-01

    This paper presents the development of a reconfigurable receiver to undertake challenging signal processing tasks for a novel polarimetric radar system. The field-programmable gate arrays (FPGAs)-based digital receiver samples incoming signals at intermediate frequency (IF) and processes signals

  20. Multi-look polarimetric SAR image filtering using simulated annealing

    DEFF Research Database (Denmark)

    Schou, Jesper

    2000-01-01

    Based on a previously published algorithm capable of estimating the radar cross-section in synthetic aperture radar (SAR) intensity images, a new filter is presented utilizing multi-look polarimetric SAR images. The underlying mean covariance matrix is estimated from the observed sample covariance...

  1. The Danish polarimetric SAR for remote sensing applications

    DEFF Research Database (Denmark)

    Christensen, Erik Lintz; Madsen, Søren Nørvang; Dall, Jørgen

    1994-01-01

    Presents the Danish polarimetric SAR system, EMISAR, and the approach taken in the system design to achieve a reliable high performance system. The design and implementation of the antenna system as well as the analog and digital hardware are discussed. The SAR utilises a dual polarised microstri...

  2. L-Band Polarimetric Correlation Radiometer with Subharmonic Sampling

    DEFF Research Database (Denmark)

    Rotbøll, Jesper; Søbjærg, Sten Schmidl; Skou, Niels

    2001-01-01

    A novel L-band radiometer trading analog complexity for digital ditto has been designed and built. It is a fully polarimetric radiometer of the correlation type and it is based on the sub-harmonic sampling principle in which the L-band signal is directly sampled by a fast A to D converter...

  3. Processing of dual-orthogonal cw polarimetric radar signals

    NARCIS (Netherlands)

    Babur, G.

    2009-01-01

    The thesis consists of two parts. The first part is devoted to the theory of dual-orthogonal polarimetric radar signals with continuous waveforms. The thesis presents a comparison of the signal compression techniques, namely correlation and de-ramping methods, for the dual-orthogonal sophisticated

  4. A novel L-band polarimetric radiometer featuring subharmonic sampling

    DEFF Research Database (Denmark)

    Rotbøll, J.; Søbjærg, Sten Schmidl; Skou, Niels

    2003-01-01

    A novel L-band radiometer trading analog components for digital circuits has been designed, built and operated. It is a fully polarimetric radiometer of the correlation type, and it is based on the subharmonic sampling principle in which the L-band signal is directly sampled by a fast A to D...

  5. Project PHARUS: Towards a polarimetric C-band airborne SAR

    NARCIS (Netherlands)

    Hoogeboom, P.; Koomen, P.J.; Otten, M.P.G.; Pouwels, H.; Snoeij, P.

    1989-01-01

    A few years ago three institutes in the Netherlands developed a plan to design and build a polarimetric C-band aircraft SAR system of a novel design, called PHARUS (PHased Array Universal SAR), meant as a replacement for our current digital SLAR system. These institutes are the Physics and

  6. Visible Nulling Coronagraphy for Exo-Planetary Detection and Characterization

    Science.gov (United States)

    Lyon, Richard G.; Clampin, Mark; Woodruff, Robert; Vasudevan, Gopal; Shao, Mike; Levine, Martin; Melnick, Gary; Tolls, Volker; Petrone, Peter; Dogoda, Peter; Duval, Julia; Ge, Jian

    Visible Nulling Coronagraphy (VNC) is the proposed method of detecting and characterizing exo-solar Jovian planets (null depth 10-9) for the proposed NASA's Extrasolar Planetary Imaging Coronagraph (EPIC) Clampin & Lyon 2004 and is an approach under evaluation for NASA's Terrestrial Planet Finder (TPF) mission. The VNC approach uses a single unobscured filled-aperture telescope and splits, via a 50:50 beamsplitter, its re-imaged pupil into two paths within a Mach-Zender interferometer. An achromatic PI phase shift is imposed onto one beam path and the two paths are laterally sheared with respect to each other. The two beams are recombined at a second 50:50 beamsplitter. The net effect is that the on axis (stellar) light is transmitted out of the bright interferometer arm while the off-axis (planetary) light is transmitted out of the nulled interferometer arm. The bright output is used for fine pointing control and coarse wavefront control. The nulled output is relayed to the science camera for science imagery and fine wavefront control. The actual transmission pattern, projected on the sky, follows a θ^2 pattern for a single shear, θ^4 for a double shear, with the spacing of the successive maxima proportional to the inverse of the relative lateral shear. Combinations of shears and spacecraft rolls build up the spatial frequency content of the sky transmission pattern in the same manner as imaging interferometer builds up the spatial frequency content of the image.

  7. Viruses in Marine Animals: Discovery, Detection, and Characterization

    Science.gov (United States)

    Fahsbender, Elizabeth

    Diseases in marine animals are emerging at an increasing rate. Disease forecasting enabled by virus surveillance presents a proactive solution for managing emerging diseases. Broad viral surveys aid in disease forecasting by providing baseline data on viral diversity associated with various hosts, including many that are not associated with disease. However, these viruses can become pathogens due to expansion in host or geographic range, as well as when changing conditions shift the balance between commensal viruses and the host immune system. Therefore, it is extremely valuable to identify and characterize viruses present in many different hosts in a variety of environments, regardless of whether the hosts are symptomatic or not. The lack of a universal gene shared by all viruses makes virus surveillance difficult, because no single assay exists that can detect the enormous diversity of viruses. Viral metagenomics circumvents this issue by purifying viral particles directly from host tissues and sequencing the nucleic acids, allowing for virus identification. However, virus identification is only the first step, which should ideally be followed by complete sequencing of the viral genome to identify genes of interest and develop assays to reveal viral prevalence, tropism, ecology, and pathogenicity. This dissertation focuses on the discovery of novel viruses in marine animals, characterization of complete viral genomes, and the development of subsequent diagnostic assays for further analysis of virus ecology. First, viral metagenomics was used to explore the viruses present in the healthy Weddell seal (Leptonychotes weddellii) population in Antarctica, which led to the discovery of highly prevalent small, circular single-stranded DNA (ssDNA) viruses. The lack of knowledge regarding the viruses of Antarctic wildlife warrants this study to determine baseline viral communities in healthy animals that can be used to survey changes over time. From the healthy Weddell

  8. Integrated, Dual Orthogonal Antennas for Polarimetric Ground Penetrating Radar

    Science.gov (United States)

    Pauli, Mario; Wiesbeck, Werner

    2015-04-01

    Ground penetrating radar systems are mostly equipped with single polarized antennas, for example with single linear polarization or with circular polarization. The radiated waves are partly reflected at the ground surface and very often the penetrating waves are distorted in their polarization. The distortion depends on the ground homogeneity and the orientation of the antennas relative to the ground structure. The received signals from the reflecting objects may most times only be classified according to their coverage and intensity. This makes the recognition of the objects difficult or impossible. In airborne and spaceborne Remote Sensing the systems are meanwhile mostly equipped with front ends with dual orthogonal polarized antennas for a full polarimetric operation. The received signals, registered in 2x2 scattering matrices according to co- and cross polarization, are processed for the evaluation of all features of the targets. Ground penetrating radars could also profit from the scientific results of Remote Sensing. The classification of detected objects for their structure and orientation requires more information in the reflected signal than can be measured with a single polarization [1, 2]. In this paper dual linear, orthogonal polarized antennas with a common single, frequency independent phase center, are presented [3]. The relative bandwidth of these antennas can be 1:3, up to 1:4. The antenna is designed to work in the frequency range between 3 GHz and 11 GHz, but can be easily adapted to the GPR frequency range by scaling. The size of the antenna scaled for operation in typical GPR frequencies would approximately be 20 by 20 cm2. By the implementation in a dielectric carrier it could be reduced in size if required. The major problem for ultra wide band, dual polarized antennas is the frequency independent feed network, realizing the required phase shifts. For these antennas a network, which is frequency independent over a wide range, has been

  9. Precipitation microphysics characteristics of a Typhoon Matmo (2014) rainband after landfall over eastern China based on polarimetric radar observations

    Science.gov (United States)

    Wang, Mingjun; Zhao, Kun; Xue, Ming; Zhang, Guifu; Liu, Su; Wen, Long; Chen, Gang

    2016-10-01

    The evolution of microphysical characteristics of a rainband in Typhoon Matmo (2014) over eastern China, through its onset, developing, mature, and dissipating stages, is documented using observations from an S band polarimetric Doppler radar and a two-dimensional video disdrometer (2DVD). The drop size distributions observed by the 2DVD and retrieved from the polarimetric radar measurements indicate that the convection in the rainband generally contains smaller drops and higher number concentrations than the typical maritime type convection described in Bringi et al. (2003). The average mass-weighted mean diameter (Dm) of convective precipitation in the rainband is about 1.41 mm, and the average logarithmic normalized intercept (Nw) is 4.67 log10 mm-1 m-3. To further investigate the dominant microphysical processes, the evolution of the vertical structures of polarimetric variables is examined. Results show that complex ice processes are involved above the freezing level, while it is most likely that the accretion and/or coalescence processes dominate below the freezing level throughout the rainband life cycle. A combined examination of the polarimetric measurements and profiles of estimated vertical liquid and ice water contents indicates that the conversion of cloud water into rainwater through cloud water accretion by raindrops plays a dominant role in producing heavy rainfall. The high estimated precipitation efficiency of 50% also suggests that cloud water accretion is the dominant mechanism for producing heavy rainfall. This study represents the first time that radar and 2DVD observations are used together to characterize the microphysical characteristics and precipitation efficiency for typhoon rainbands in China.

  10. A NEW SAR CLASSIFICATION SCHEME FOR SEDIMENTS ON INTERTIDAL FLATS BASED ON MULTI-FREQUENCY POLARIMETRIC SAR IMAGERY

    Directory of Open Access Journals (Sweden)

    W. Wang

    2017-11-01

    Full Text Available We present a new classification scheme for muddy and sandy sediments on exposed intertidal flats, which is based on synthetic aperture radar (SAR data, and use ALOS-2 (L-band, Radarsat-2 (C-band and TerraSAR-X (X-band fully polarimetric SAR imagery to demonstrate its effectiveness. Four test sites on the German North Sea coast were chosen, which represent typical surface compositions of different sediments, vegetation, and habitats, and of which a large amount of SAR is used for our analyses. Both Freeman-Durden and Cloude-Pottier polarimetric decomposition are utilized, and an additional descriptor called Double-Bounce Eigenvalue Relative Difference (DERD is introduced into the feature sets instead of the original polarimetric intensity channels. The classification is conducted following Random Forest theory, and the results are verified using ground truth data from field campaigns and an existing classification based on optical imagery. In addition, the use of Kennaugh elements for classification purposes is demonstrated using both fully and dual-polarization multi-frequency and multi-temporal SAR data. Our results show that the proposed classification scheme can be applied for the discrimination of muddy and sandy sediments using L-, C-, and X-band SAR images, while SAR imagery acquired at short wavelengths (C- and X-band can also be used to detect more detailed features such as bivalve beds on intertidal flats.

  11. Interference figures of polarimetric interferometry analysis of the human corneal stroma.

    Directory of Open Access Journals (Sweden)

    Rodolfo Mastropasqua

    Full Text Available A rotating polarimetric 90°-cross linear-filter interferometry system was used to detect the morphological characteristics and features of interference patterns produced in in-vivo corneal stroma in healthy human corneas of 23 subjects. The characteristic corneal isogyres presenting with an evident cross-shaped pattern, grossly aligned with the fixation axis, were observed in all patients with centers within the pupillary dark area, impeding the exact determination of the center point. During the rotational scan in 78.3% of the eyes the cross-shaped pattern of the isogyre gradually separated to form two distinct hyperbolic arcs in opposite quadrants, reaching their maximal separation at 45 degrees with respect to angle of cross-shaped pattern formation. The corneal cross and hyperbolic-pattern repeated every 90° throughout the 360° rotational scan. While the interpretation of the isogyres presents particular difficulties, two summary parameters can be extracted for each cornea: the presence/orientation of a single or two dark areas in post-processed images and isochromes. However, the development of dedicated software for semi-quantitative analysis of these parameters and enantiomorphism may become available in the near future. The possible application of polarimetric interferometry in the field of both corneal pathologies and corneal surgery may be of great interest for clinical purposes.

  12. Full polarimetric millimetre wave radar for stand-off security screening

    Science.gov (United States)

    Blackhurst, Eddie; Salmon, Neil; Southgate, Matthew

    2017-10-01

    The development and measurements are described of a frequency modulated continuous wave (FMCW) mono-static millimetre wave full polarimetric radar, operating at k-band (18 to 26 GHz). The system has been designed to explore the feasibility of using full polarimetry for the detection of concealed weapons, and person borne improvised explosive devices (PBIED). The philosophy of this scheme is a means to extract the maximum information content from a target which is normally in the single spatial pixel (sometimes sub-pixel) configuration in stand-off (tens of metres) and crowd surveillance scenarios. The radar comprises a vector network analyser (VNA), an orthomode transducer and a conical horn antenna. A calibration strategy is discussed and demonstrated using a variety of known calibration targets with known reflective properties, including a flat metal plate, dihedral reflector, metal sphere, helix and dipole. The orthomode transducer is based on a high performance linear polarizer of the turnstile type with isolation better than - 35dB between orthogonal polarisations. The calibration enables the polarimetric Sinclair scattering matrix to be measured at each frequency for coherent polarimetry, and this can be extended using multiple measurements via the Kennaugh matrix to investigate incoherent full polarimetry.

  13. A generalized coherence framework for detecting and characterizing nonlinear interactions in the nervous system

    NARCIS (Netherlands)

    Yang, Y.; Solis Escalante, T.; van der Helm, F.C.T.; Schouten, A.C.

    2016-01-01

    Objective: This paper introduces a generalized coherence framework for detecting and characterizing nonlinear interactions in the nervous system, namely cross-spectral coherence (CSC). CSC can detect different types of nonlinear interactions including harmonic and intermodulation coupling as present

  14. Target Detection Using an AOTF Hyperspectral Imager

    Science.gov (United States)

    Cheng, L-J.; Mahoney, J.; Reyes, F.; Suiter, H.

    1994-01-01

    This paper reports results of a recent field experiment using a prototype system to evaluate the acousto-optic tunable filter polarimetric hyperspectral imaging technology for target detection applications.

  15. Probabilistic discrimination between liquid rainfall events, hailstorms, biomass burning and industrial fires from C-Band Radar Polarimetric Variables

    Science.gov (United States)

    Valencia, J. M.; Sepúlveda, J.; Hoyos, C.; Herrera, L.

    2017-12-01

    Characterization and identification of fire and hailstorm events using weather radar data in a tropical complex topography region is an important task in risk management and agriculture. Polarimetric variables from a C-Band Dual polarization weather radar have potential uses in particle classification, due to the relationship their sensitivity to shape, spatial orientation, size and fall behavior of particles. In this sense, three forest fires and two chemical fires were identified for the Áburra Valley regions. Measurements were compared between each fire event type and with typical data radar retrievals for liquid precipitation events. Results of this analysis show different probability density functions for each type of event according to the particles present in them. This is very important and useful result for early warning systems to avoid precipitation false alarms during fire events within the study region, as well as for the early detection of fires using radar retrievals in remote cases. The comparative methodology is extended to hailstorm cases. Complementary sensors like laser precipitation sensors (LPM) disdrometers and meteorological stations were used to select dates of solid precipitation occurrence. Then, in this dates weather radar data variables were taken in pixels surrounding the stations and solid precipitation polar values were statistically compared with liquid precipitation values. Spectrum precipitation measured by LPM disdrometer helps to define typical features like particles number, fall velocities and diameters for both precipitation types. In addition, to achieve a complete hailstorm characterization, other meteorological variables were analyzed: wind field from meteorological stations and radar wind profiler, profiling data from Micro Rain Radar (MRR), and thermodynamic data from a microwave radiometer.

  16. Detection and characterization with short TI inversion recovery MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Komata, Kaori (Nippon Medical School, Tokyo (Japan))

    1994-10-01

    Short TI inversion recovery magnetic resonance imaging (STIR-MRI) with spin echo (SE) T1- and T2-weighted images of the pelvis was investigated to evaluate its usefulness in detecting and characterizing endometriosis. Thirty-one women suspected of having the disease were studied in detail. MR findings with and without STIR-MRI were correlated with the results of laparotomy (27 women) and laparoscopy (4 women). Surgery revealed endometriosis in 29 women (17 ovarian chocolate cysts, 22 intestinal adhesions, 14 cul-de-sac obliterations and 12 adenomyosis). The other two women did not have endometriosis (uterine prolapse in one and submucosal leiomyoma in one). An ovarian chocolate cyst was diagnosed when a T1-elongated lesion showed shading, loculus or a low intensity rim on SE MR images, and a low intensity rim on STIR-MRI. Only 12 of the 17 chocolate cysts and neither of the two hemorrhagic corpus lutein cysts were correctly diagnosed on SE MR images, whereas 18 of these 19 cysts were correctly diagnosed because of the low intensity rim on STIR-MRI. In the pathological analysis, the rim was found to be a fibrous capsule and there were many macrophages which phagocytized hemosiderin. For the assessment of ovarian chocolate cysts, accuracy improved from 63.2% to 94.7%. As for the adhesion between the intestine and the uterus, specificity improved from 61.9% to 90.5% and accuracy improved from 67.7% to 93.5% when STRI-MRI was used. For the assessment of the cul-de-sac obliteration, accuracy improved from 67.7% to 83.8% although [chi][sup 2] analysis showed no significance. The major factors for the improved accuracy with STIR-MRI are the decrease of the motion artifact owing to the suppression of the fat signal, decreased chemical shift artifact and accurate differentiation of fat from hemorrhagic component. Therefore, STIR-MRI is a useful and reliable procedure and should be used together with SE T1-, T2-weighted images for the assessment of endometriosis. (author).

  17. Detection and characterization with short TI inversion recovery MR imaging

    International Nuclear Information System (INIS)

    Komata, Kaori

    1994-01-01

    Short TI inversion recovery magnetic resonance imaging (STIR-MRI) with spin echo (SE) T1- and T2-weighted images of the pelvis was investigated to evaluate its usefulness in detecting and characterizing endometriosis. Thirty-one women suspected of having the disease were studied in detail. MR findings with and without STIR-MRI were correlated with the results of laparotomy (27 women) and laparoscopy (4 women). Surgery revealed endometriosis in 29 women (17 ovarian chocolate cysts, 22 intestinal adhesions, 14 cul-de-sac obliterations and 12 adenomyosis). The other two women did not have endometriosis (uterine prolapse in one and submucosal leiomyoma in one). An ovarian chocolate cyst was diagnosed when a T1-elongated lesion showed shading, loculus or a low intensity rim on SE MR images, and a low intensity rim on STIR-MRI. Only 12 of the 17 chocolate cysts and neither of the two hemorrhagic corpus lutein cysts were correctly diagnosed on SE MR images, whereas 18 of these 19 cysts were correctly diagnosed because of the low intensity rim on STIR-MRI. In the pathological analysis, the rim was found to be a fibrous capsule and there were many macrophages which phagocytized hemosiderin. For the assessment of ovarian chocolate cysts, accuracy improved from 63.2% to 94.7%. As for the adhesion between the intestine and the uterus, specificity improved from 61.9% to 90.5% and accuracy improved from 67.7% to 93.5% when STRI-MRI was used. For the assessment of the cul-de-sac obliteration, accuracy improved from 67.7% to 83.8% although χ 2 analysis showed no significance. The major factors for the improved accuracy with STIR-MRI are the decrease of the motion artifact owing to the suppression of the fat signal, decreased chemical shift artifact and accurate differentiation of fat from hemorrhagic component. Therefore, STIR-MRI is a useful and reliable procedure and should be used together with SE T1-, T2-weighted images for the assessment of endometriosis. (author)

  18. INVENTORY OF IRRIGATED RICE ECOSYSTEM USING POLARIMETRIC SAR DATA

    Directory of Open Access Journals (Sweden)

    P. Srikanth

    2012-08-01

    Full Text Available An attempt has been made in the current study to assess the potential of polarimetric SAR data for inventory of kharif rice and the major competing crop like cotton. In the process, physical process of the scattering mechanisms occurring in rice and cotton crops at different phonological stages was studied through the use of temporal Radarsat 2 Fine quadpol SAR data. The temporal dynamics of the volume, double and odd bounce, entropy, anisotropy, alpha parameters and polarimertic signatures, classification through isodata clustering and Wishart techniques were assessed. The Wishart (H-a classification showed higher overall as well as rice and cotton crop accuracies compared to the isodata clustering from Freeman 3-component decomposition. The classification of temporal SAR data sets independently showed that the rice crop forecasting can be advanced with the use of appropriate single date polarimetric SAR data rather than using temporal SAR amplitude data sets with the single polarization in irrigated rice ecosystems

  19. The orbital inclination of Cygnus XR-1 measured polarimetrically

    International Nuclear Information System (INIS)

    Dolan, J.F.; Tapia, S.

    1989-01-01

    The X-ray binary Cyg XR-1/HDE 226868 was observed polarimetrically over one orbit at three different optical wavelengths. The standard theory of Brown, et al. (1978) is used to derive an orbital inclination i = 62 deg (+5 deg, -37 deg), where the error is the 90-percent-confidence interval derived by the method of Simmons, et al. (1980). The value of the orbital inclination is significantly lower than values based on polarimetric observations. The difference is a result of the observational protocols used. A bias toward larger values of the inclination caused by the tidal distortion of the primary is still found in the present result. The inclination derived corresponds to a mass of the compact component of 6.3 solar masses, above the maximum mass of any degenerate configuration consistent with general relativity except a black hole. 37 refs

  20. Integrated quantitative fractal polarimetric analysis of monolayer lung cancer cells

    Science.gov (United States)

    Shrestha, Suman; Zhang, Lin; Quang, Tri; Farrahi, Tannaz; Narayan, Chaya; Deshpande, Aditi; Na, Ying; Blinzler, Adam; Ma, Junyu; Liu, Bo; Giakos, George C.

    2014-05-01

    Digital diagnostic pathology has become one of the most valuable and convenient advancements in technology over the past years. It allows us to acquire, store and analyze pathological information from the images of histological and immunohistochemical glass slides which are scanned to create digital slides. In this study, efficient fractal, wavelet-based polarimetric techniques for histological analysis of monolayer lung cancer cells will be introduced and different monolayer cancer lines will be studied. The outcome of this study indicates that application of fractal, wavelet polarimetric principles towards the analysis of squamous carcinoma and adenocarcinoma cancer cell lines may be proved extremely useful in discriminating among healthy and lung cancer cells as well as differentiating among different lung cancer cells.

  1. Multispectral and polarimetric photodetection using a plasmonic metasurface

    Science.gov (United States)

    Pelzman, Charles; Cho, Sang-Yeon

    2018-01-01

    We present a metasurface-integrated Si 2-D CMOS sensor array for multispectral and polarimetric photodetection applications. The demonstrated sensor is based on the polarization selective extraordinary optical transmission from periodic subwavelength nanostructures, acting as artificial atoms, known as meta-atoms. The meta-atoms were created by patterning periodic rectangular apertures that support optical resonance at the designed spectral bands. By spatially separating meta-atom clusters with different lattice constants and orientations, the demonstrated metasurface can convert the polarization and spectral information of an optical input into a 2-D intensity pattern. As a proof-of-concept experiment, we measured the linear components of the Stokes parameters directly from captured images using a CMOS camera at four spectral bands. Compared to existing multispectral polarimetric sensors, the demonstrated metasurface-integrated CMOS system is compact and does not require any moving components, offering great potential for advanced photodetection applications.

  2. DNA based methods used for characterization and detection of food ...

    African Journals Online (AJOL)

    Detection of food borne pathogen is of outmost importance in the food industries and related agencies. For the last few decades conventional methods were used to detect food borne pathogens based on phenotypic characters. At the advent of complementary base pairing and amplification of DNA, the diagnosis of food ...

  3. DNA based methods used for characterization and detection of food ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-04

    May 4, 2009 ... selective medium followed by plating in differential agar medium ... result. Biochemical and immunological methods for the detection require substantial amount of pure culture whereas .... biotin (chemiluminescent) probes are detected visually. It ..... are also gathering special attention due to their covalent.

  4. Retrieval of ice thickness from polarimetric SAR data

    Science.gov (United States)

    Kwok, R.; Yueh, S. H.; Nghiem, S. V.; Huynh, D. D.

    1993-01-01

    We describe a potential procedure for retrieving ice thickness from multi-frequency polarimetric SAR data for thin ice. This procedure includes first masking out the thicker ice types with a simple classifier and then deriving the thickness of the remaining pixels using a model-inversion technique. The technique used to derive ice thickness from polarimetric observations is provided by a numerical estimator or neural network. A three-layer perceptron implemented with the backpropagation algorithm is used in this investigation with several improved aspects for a faster convergence rate and a better accuracy of the neural network. These improvements include weight initialization, normalization of the output range, the selection of offset constant, and a heuristic learning algorithm. The performance of the neural network is demonstrated by using training data generated by a theoretical scattering model for sea ice matched to the database of interest. The training data are comprised of the polarimetric backscattering coefficients of thin ice and the corresponding input ice parameters to the scattering model. The retrieved ice thickness from the theoretical backscattering coefficients is compare with the input ice thickness to the scattering model to illustrate the accuracy of the inversion method. Results indicate that the network convergence rate and accuracy are higher when multi-frequency training sets are presented. In addition, the dominant backscattering coefficients in retrieving ice thickness are found by comparing the behavior of the network trained backscattering data at various incidence angels. After the neural network is trained with the theoretical backscattering data at various incidence anges, the interconnection weights between nodes are saved and applied to the experimental data to be investigated. In this paper, we illustrate the effectiveness of this technique using polarimetric SAR data collected by the JPL DC-8 radar over a sea ice scene.

  5. Polarimetric neutron spin echo: Feasibility and first results

    Energy Technology Data Exchange (ETDEWEB)

    Pappas, C. [Hahn-Meitner Institut Berlin, Glienickerstr. 100, 14109 Berlin (Germany)], E-mail: pappas@hmi.de; Lelievre-Berna, E. [Institut Laue-Langevin, 6, Rue Jules Horowitz, 38042 Grenoble (France); Bentley, P. [Hahn-Meitner Institut Berlin, Glienickerstr. 100, 14109 Berlin (Germany); Bourgeat-Lami, E. [Institut Laue-Langevin, 6, Rue Jules Horowitz, 38042 Grenoble (France); Moskvin, E. [Hahn-Meitner Institut Berlin, Glienickerstr. 100, 14109 Berlin (Germany); PNPI, 188300 Gatchina, Leningrad District (Russian Federation); Thomas, M. [Institut Laue-Langevin, 6, Rue Jules Horowitz, 38042 Grenoble (France); Grigoriev, S.; Dyadkin, V. [PNPI, 188300 Gatchina, Leningrad District (Russian Federation)

    2008-07-21

    Neutron Spin Echo (NSE) spectroscopy uses polarized neutrons and accordingly polarization analysis is an intrinsic feature of NSE. However, the multifaceted dynamics of antiferromagnets and helimagnets require more than the classical NSE set-up. Here we present the feasibility test and first results of a new and powerful technique: Polarimetric NSE, obtained by combining the wide angle NSE spectrometer SPAN, developed at HMI with the zero-field polarimeter Cryopad developed at ILL.

  6. Polarimetric neutron spin echo: Feasibility and first results

    International Nuclear Information System (INIS)

    Pappas, C.; Lelievre-Berna, E.; Bentley, P.; Bourgeat-Lami, E.; Moskvin, E.; Thomas, M.; Grigoriev, S.; Dyadkin, V.

    2008-01-01

    Neutron Spin Echo (NSE) spectroscopy uses polarized neutrons and accordingly polarization analysis is an intrinsic feature of NSE. However, the multifaceted dynamics of antiferromagnets and helimagnets require more than the classical NSE set-up. Here we present the feasibility test and first results of a new and powerful technique: Polarimetric NSE, obtained by combining the wide angle NSE spectrometer SPAN, developed at HMI with the zero-field polarimeter Cryopad developed at ILL

  7. Detection and characterization of ship targets using CryoSat-2 altimeter waveforms

    OpenAIRE

    G?mez-Enri, Jesus; Scozzari, Andrea; Soldovieri, Francesco; Coca, Josep; Vignudelli, Stefano

    2016-01-01

    This article describes an investigation of the new possibilities offered by SAR altimetry compared with conventional altimetry in the detection and characterization of non-ocean targets. We explore the capabilities of the first SAR altimeter installed on the European Space Agency satellite CryoSat-2 for the detection and characterization of ships. We propose a methodology for the detection of anomalous targets in the radar signals, based on the advantages of SAR/Doppler processing over conven...

  8. Molecular detection and characterization of VRSA among clinical ...

    African Journals Online (AJOL)

    *

    Available online at http://www.academicjournals.org/AJB ... Until now, few strains of vancomycin resistant Staphylococcus aureus (VRSA) have been ... Multiplex polymerase chain reaction (PCR) detection method for vancomycin resistant S.

  9. Use of Radarsat-2 polarimetric SAR images for fuel moisture mapping in the Kruger National Park, South Africa

    CSIR Research Space (South Africa)

    Kong, M

    2015-08-01

    Full Text Available of winter, dry). Sample plots were classified into two broad Lowveld site types (herbaceous-dominated and shrub and tree-dominated). Linear and circular polarized backscatters, polarimetric discriminators and polarimetric decomposition parameters were...

  10. Characterization of the nasal and oral microbiota of detection dogs.

    Directory of Open Access Journals (Sweden)

    Anitha Isaiah

    Full Text Available Little is known about physiological factors that affect the sense of olfaction in dogs. The objectives of this study were to describe the canine nasal and oral microbiota in detection dogs. We sought to determine the bacterial composition of the nasal and oral microbiota of a diverse population of detection canines. Nasal and oral swabs were collected from healthy dogs (n = 81 from four locations-Alabama, Georgia, California, and Texas. Nasal and oral swabs were also collected from a second cohort of detection canines belonging to three different detection job categories: explosive detection dogs (SP-E; n = 22, patrol and narcotics detection dogs (P-NDD; n = 15, and vapor wake dogs (VWD-E; n = 9. To understand if the nasal and oral microbiota of detection canines were variable, sample collection was repeated after 7 weeks in a subset of dogs. DNA was extracted from the swabs and used for 454-pyrosequencing of the16S rRNA genes. Nasal samples had a significantly lower diversity than oral samples (P<0.01. Actinobacteria and Proteobacteria were higher in nasal samples, while Bacteroidetes, Firmicutes, Fusobacteria, and Tenericutes were higher in oral samples. Bacterial diversity was not significantly different based on the detection job. No significant difference in beta diversity was observed in the nasal samples based on the detection job. In oral samples, however, ANOSIM suggested a significant difference in bacterial communities based on job category albeit with a small effect size (R = 0.1079, P = 0.02. Analysis of the composition of bacterial communities using LEfSe showed that within the nasal samples, Cardiobacterium and Riemerella were higher in VWD-E dogs, and Sphingobacterium was higher in the P-NDD group. In the oral samples Enterococcus and Capnocytophaga were higher in the P-NDD group. Gemella and Aggregatibacter were higher in S-PE, and Pigmentiphaga, Chryseobacterium, Parabacteroides amongst others were higher within the VWD-E group

  11. Characterization of the nasal and oral microbiota of detection dogs.

    Science.gov (United States)

    Isaiah, Anitha; Hoffmann, Aline Rodrigues; Kelley, Russ; Mundell, Paul; Steiner, Jörg M; Suchodolski, Jan S

    2017-01-01

    Little is known about physiological factors that affect the sense of olfaction in dogs. The objectives of this study were to describe the canine nasal and oral microbiota in detection dogs. We sought to determine the bacterial composition of the nasal and oral microbiota of a diverse population of detection canines. Nasal and oral swabs were collected from healthy dogs (n = 81) from four locations-Alabama, Georgia, California, and Texas. Nasal and oral swabs were also collected from a second cohort of detection canines belonging to three different detection job categories: explosive detection dogs (SP-E; n = 22), patrol and narcotics detection dogs (P-NDD; n = 15), and vapor wake dogs (VWD-E; n = 9). To understand if the nasal and oral microbiota of detection canines were variable, sample collection was repeated after 7 weeks in a subset of dogs. DNA was extracted from the swabs and used for 454-pyrosequencing of the16S rRNA genes. Nasal samples had a significantly lower diversity than oral samples (P<0.01). Actinobacteria and Proteobacteria were higher in nasal samples, while Bacteroidetes, Firmicutes, Fusobacteria, and Tenericutes were higher in oral samples. Bacterial diversity was not significantly different based on the detection job. No significant difference in beta diversity was observed in the nasal samples based on the detection job. In oral samples, however, ANOSIM suggested a significant difference in bacterial communities based on job category albeit with a small effect size (R = 0.1079, P = 0.02). Analysis of the composition of bacterial communities using LEfSe showed that within the nasal samples, Cardiobacterium and Riemerella were higher in VWD-E dogs, and Sphingobacterium was higher in the P-NDD group. In the oral samples Enterococcus and Capnocytophaga were higher in the P-NDD group. Gemella and Aggregatibacter were higher in S-PE, and Pigmentiphaga, Chryseobacterium, Parabacteroides amongst others were higher within the VWD-E group. Our initial

  12. Performance Considerations for the SIMPL Single Photon, Polarimetric, Two-Color Laser Altimeter as Applied to Measurements of Forest Canopy Structure and Composition

    Science.gov (United States)

    Dabney, Philip W.; Harding, David J.; Valett, Susan R.; Vasilyev, Aleksey A.; Yu, Anthony W.

    2012-01-01

    The Slope Imaging Multi-polarization Photon-counting Lidar (SIMPL) is a multi-beam, micropulse airborne laser altimeter that acquires active and passive polarimetric optical remote sensing measurements at visible and near-infrared wavelengths. SIMPL was developed to demonstrate advanced measurement approaches of potential benefit for improved, more efficient spaceflight laser altimeter missions. SIMPL data have been acquired for wide diversity of forest types in the summers of 2010 and 2011 in order to assess the potential of its novel capabilities for characterization of vegetation structure and composition. On each of its four beams SIMPL provides highly-resolved measurements of forest canopy structure by detecting single-photons with 15 cm ranging precision using a narrow-beam system operating at a laser repetition rate of 11 kHz. Associated with that ranging data SIMPL provides eight amplitude parameters per beam unlike the single amplitude provided by typical laser altimeters. Those eight parameters are received energy that is parallel and perpendicular to that of the plane-polarized transmit pulse at 532 nm (green) and 1064 nm (near IR), for both the active laser backscatter retro-reflectance and the passive solar bi-directional reflectance. This poster presentation will cover the instrument architecture and highlight the performance of the SIMPL instrument with examples taken from measurements for several sites with distinct canopy structures and compositions. Specific performance areas such as probability of detection, after pulsing, and dead time, will be highlighted and addressed, along with examples of their impact on the measurements and how they limit the ability to accurately model and recover the canopy properties. To assess the sensitivity of SIMPL's measurements to canopy properties an instrument model has been implemented in the FLIGHT radiative transfer code, based on Monte Carlo simulation of photon transport. SIMPL data collected in 2010 over

  13. Comparison and Characterization of Android-Based Fall Detection Systems

    Directory of Open Access Journals (Sweden)

    Rafael Luque

    2014-10-01

    Full Text Available Falls are a foremost source of injuries and hospitalization for seniors. The adoption of automatic fall detection mechanisms can noticeably reduce the response time of the medical staff or caregivers when a fall takes place. Smartphones are being increasingly proposed as wearable, cost-effective and not-intrusive systems for fall detection. The exploitation of smartphones’ potential (and in particular, the Android Operating System can benefit from the wide implantation, the growing computational capabilities and the diversity of communication interfaces and embedded sensors of these personal devices. After revising the state-of-the-art on this matter, this study develops an experimental testbed to assess the performance of different fall detection algorithms that ground their decisions on the analysis of the inertial data registered by the accelerometer of the smartphone. Results obtained in a real testbed with diverse individuals indicate that the accuracy of the accelerometry-based techniques to identify the falls depends strongly on the fall pattern. The performed tests also show the difficulty to set detection acceleration thresholds that allow achieving a good trade-off between false negatives (falls that remain unnoticed and false positives (conventional movements that are erroneously classified as falls. In any case, the study of the evolution of the battery drain reveals that the extra power consumption introduced by the Android monitoring applications cannot be neglected when evaluating the autonomy and even the viability of fall detection systems.

  14. Comparison and characterization of Android-based fall detection systems.

    Science.gov (United States)

    Luque, Rafael; Casilari, Eduardo; Morón, María-José; Redondo, Gema

    2014-10-08

    Falls are a foremost source of injuries and hospitalization for seniors. The adoption of automatic fall detection mechanisms can noticeably reduce the response time of the medical staff or caregivers when a fall takes place. Smartphones are being increasingly proposed as wearable, cost-effective and not-intrusive systems for fall detection. The exploitation of smartphones' potential (and in particular, the Android Operating System) can benefit from the wide implantation, the growing computational capabilities and the diversity of communication interfaces and embedded sensors of these personal devices. After revising the state-of-the-art on this matter, this study develops an experimental testbed to assess the performance of different fall detection algorithms that ground their decisions on the analysis of the inertial data registered by the accelerometer of the smartphone. Results obtained in a real testbed with diverse individuals indicate that the accuracy of the accelerometry-based techniques to identify the falls depends strongly on the fall pattern. The performed tests also show the difficulty to set detection acceleration thresholds that allow achieving a good trade-off between false negatives (falls that remain unnoticed) and false positives (conventional movements that are erroneously classified as falls). In any case, the study of the evolution of the battery drain reveals that the extra power consumption introduced by the Android monitoring applications cannot be neglected when evaluating the autonomy and even the viability of fall detection systems.

  15. Comparison and Characterization of Android-Based Fall Detection Systems

    Science.gov (United States)

    Luque, Rafael; Casilari, Eduardo; Morón, María-José; Redondo, Gema

    2014-01-01

    Falls are a foremost source of injuries and hospitalization for seniors. The adoption of automatic fall detection mechanisms can noticeably reduce the response time of the medical staff or caregivers when a fall takes place. Smartphones are being increasingly proposed as wearable, cost-effective and not-intrusive systems for fall detection. The exploitation of smartphones' potential (and in particular, the Android Operating System) can benefit from the wide implantation, the growing computational capabilities and the diversity of communication interfaces and embedded sensors of these personal devices. After revising the state-of-the-art on this matter, this study develops an experimental testbed to assess the performance of different fall detection algorithms that ground their decisions on the analysis of the inertial data registered by the accelerometer of the smartphone. Results obtained in a real testbed with diverse individuals indicate that the accuracy of the accelerometry-based techniques to identify the falls depends strongly on the fall pattern. The performed tests also show the difficulty to set detection acceleration thresholds that allow achieving a good trade-off between false negatives (falls that remain unnoticed) and false positives (conventional movements that are erroneously classified as falls). In any case, the study of the evolution of the battery drain reveals that the extra power consumption introduced by the Android monitoring applications cannot be neglected when evaluating the autonomy and even the viability of fall detection systems. PMID:25299953

  16. Foliage penetration radar detection and characterization of objects under trees

    CERN Document Server

    Davis, Mark

    2011-01-01

    This book covers all aspects of foliage penetration (FOPEN) radar, concentrating on both airborne military radar systems as well as earth resource mapping radars. It is the first concise and thorough treatment of FOPEN, covering the results of a decade-long investment by DARPA in characterizing foliage and earth surface with ultrawideband UHF and VHF synthetic aperture radar (SAR).

  17. Automatic Microaneurysm Detection and Characterization Through Digital Color Fundus Images

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Charles; Veras, Rodrigo; Ramalho, Geraldo; Medeiros, Fatima; Ushizima, Daniela

    2008-08-29

    Ocular fundus images can provide information about retinal, ophthalmic, and even systemic diseases such as diabetes. Microaneurysms (MAs) are the earliest sign of Diabetic Retinopathy, a frequently observed complication in both type 1 and type 2 diabetes. Robust detection of MAs in digital color fundus images is critical in the development of automated screening systems for this kind of disease. Automatic grading of these images is being considered by health boards so that the human grading task is reduced. In this paper we describe segmentation and the feature extraction methods for candidate MAs detection.We show that the candidate MAs detected with the methodology have been successfully classified by a MLP neural network (correct classification of 84percent).

  18. Detection and Characterization of Stress Symptoms in Forest Vegetation

    Science.gov (United States)

    Heller, R. C.

    1971-01-01

    Techniques used at the Pacific Southwest Forest and Range Experiment Station to detect advanced and previsual symptoms of vegetative stress are discussed. Stresses caused by bark beetles in coniferous stands of timber are emphasized because beetles induce stress more rapidly than most other destructive agents. Bark beetles are also the most damaging forest insects in the United States. In the work on stress symptoms, there are two primary objectives: (1) to learn the best combination of films, scales, and filters to detect and locate injured trees from aircraft and spacecraft, and (2) to learn if stressed trees can be detected before visual symptoms of decline occur. Equipment and techniques used in a study of the epidemic of the Black Hills bark beetle are described.

  19. Thermo-optical Characterization of Photothermal Optical Phase Shift Detection in Extended-Nano Channels and UV Detection of Biomolecules.

    Science.gov (United States)

    Shimizu, Hisashi; Miyawaki, Naoya; Asano, Yoshihiro; Mawatari, Kazuma; Kitamori, Takehiko

    2017-06-06

    The expansion of microfluidics research to nanofluidics requires absolutely sensitive and universal detection methods. Photothermal detection, which utilizes optical absorption and nonradiative relaxation, is promising for the sensitive detection of nonlabeled biomolecules in nanofluidic channels. We have previously developed a photothermal optical phase shift (POPS) detection method to detect nonfluorescent molecules sensitively, while a rapid decrease of the sensitivity in nanochannels and the introduction of an ultraviolet (UV) excitation system were issues to be addressed. In the present study, our primary aim is to characterize the POPS signal in terms of the thermo-optical properties and quantitatively evaluate the causes for the decrease in sensitivity. The UV excitation system is then introduced into the POPS detector to realize the sensitive detection of nonlabeled biomolecules. The UV-POPS detection system is designed and constructed from scratch based on a symmetric microscope. The results of simulations and experiments reveal that the sensitivity decreases due to a reduction of the detection volume, dissipation of the heat, and cancellation of the changes in the refractive indices. Finally, determination of the concentration of a nonlabeled protein (bovine serum albumin) is performed in a very thin 900 nm deep nanochannel. As a result, the limit of detection (LOD) is 2.3 μM (600 molecules in the 440 attoliter detection volume), which is as low as that previously obtained for our visible POPS detector. UV-POPS detection is thus expected be a powerful technique for the study of biomolecules, including DNAs and proteins confined in nanofluidic channels.

  20. A New Polarimetric Study of Cygnus A Using JVLA from 2-18GHz

    Science.gov (United States)

    Lerato Sebokolodi, Makhuduga; Perley, Rick; Carilli, Chris; Smirnov, Oleg M.; Makhathini, Sphesihle

    2018-01-01

    Polarimetric studies of Cygnus A [5, 1, 2, 3] have shown that this radio galaxy has unusually large rotation measures ranging from -4000 to +3000 rad m -2 for the eastern lobe (E-lobe) and -2000 to +1300 rad m -2 for western lobe(W-lobe). A challenge since then has been to identify the medium(s) responsible for these high Faraday rotations (FR). Although a majority of the FR must arise from the surrounding cluster gas, an unknown portion may arise either in the sheath or within the lobes. In these cases, some depolarization must result, along with a non λ 2 rotation of the plane of polarization. Detecting such a depolarization will enable an estimate of the internal (and/or sheath) thermal gas density. [1] found significant depolarization associated with the inner regions of the E-lobe and no depolarization associated with the W-lobe. This depolarization could be either internal to the source (Faraday depolarization) or due to unresolved small-scale fluctuations in the foreground screen (beam depolarization) [1]. The former is expected to impose significant deviations in the λ2 -law, none of which have been found to date, nor could have been found due to the limited number of frequencies employed in these studies.Since 2015, new JVLA polarimetric observations of Cygnus A have been taken, in all four configurations, covering the frequency range from 2 to 18GHz. These new data provide thousands of frequency channels at high resolution and sensitivity – opening a new opportunity to study in great detail the physics of the jets, lobes and the magnetic field of the X-ray cluster medium and lobes. Our objective is to analyze these new polarimetric data with the expectation of extending the previous work and more importantly, to investigate the possibility of any significantdeviations from the λ2-law. Initial analysis shows significant deviations from λ2 -law associated with the W-lobe. We will present these results in detail, and also the results from RM

  1. A new approach to polarimetric measurements based on birefringent crystals and diode lasers

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Lívia Paulia Dias; Rohwedder, Jarbas José Rodrigues [Chemistry Institute, Department of Analytical Chemistry, UNICAMP, Caixa Postal 6154, CEP: 13087-971 Campinas, SP (Brazil); Pasquini, Celio, E-mail: pasquini@iqm.unicamp.br [Chemistry Institute, Department of Analytical Chemistry, UNICAMP, Caixa Postal 6154, CEP: 13087-971 Campinas, SP (Brazil)

    2013-04-10

    Highlights: ► New approach to polarimetric measurements is evaluated. ► A robust, with no mechanical moving parts polarimeter is presented. ► The performance of the instrument was evaluated for saccharimetric measurements. ► The uncertainty of the instrument was evaluated as a function of the measured angle. ► Polarimeter allow the use of low cost lasers while obtaining precision as good as 0.003°. -- Abstract: A new polarimetric instrument and measurement method is described based on the use of diode lasers as radiation source (532, 650 and 1064 nm) and birefringent prisms, such as Glan-Laser and Wollaston, as analyzers. The laser radiation is passed through a dichroic polarizer film for further orientation of its polarization plane at 45° in relation to the polarization plane of the analyzer. The polarized beam, oriented in that way, passes the sample cell, impinges the prism surface, and the intensities of the two emerged beams are detected by two twin silicon detectors. Ideally, in the absence of any optically active substances, the crystals produces two orthogonally polarized refracted beams of equal intensity. In the presence of an optically active substance, the arctangent of the square root of the beam intensities ratio is equal to the new polarization angle (β) of the laser beam. The rotation angle imposed for any optically active substance present in the sample cell is then given by: α = (45 – β)°. Because the rotation is obtained by the ratio of the intensities of two beams, it is independent of the laser intensity, which can vary up to ±15% with no significant effect on the accuracy of the polarimetric measurement. The instrument has been evaluated for measurement of optically active substances such as sucrose and fructose. The instrument employs low cost components, is capable of attaining a repeatability of ±0.003° and can measure the rotation angle, over a ±45° range, in less than 2 s. Because it does not present any moving

  2. Spectral Polarimetric Features Analysis of Wind Turbine Clutter in Weather Radar

    NARCIS (Netherlands)

    Yin, J.; Krasnov, O.A.; Unal, C.M.H.; Medagli, S.; Russchenberg, H.W.J.

    2017-01-01

    Wind turbine clutter has gradually become a concern for the radar community for its increasing size and quantity worldwide. Based on the S-band polarimetric Doppler PARSAX radar measurements, this paper demonstrates the micro-Doppler features and spectral-polarimetric characteristic of wind turbine

  3. Comparative determination of sucrose content in sugar beet by polarimetric and isotope dilution methods

    Energy Technology Data Exchange (ETDEWEB)

    Malec, K; Szuchnik, A [Institute of Nuclear Research, Warsaw (Poland); Rydel, S; Walerianaczyk, E [Instytut Przemyslu Cukrowniczego, Warsaw (Poland)

    1976-01-01

    The comparative determination of sucrose content in sugar beets has been investigated by following methods: polarimetric, direct isotope dilution and double carrier-isotope dilution analysis. Basing upon the obtained results it has been ascertained, that in the case of worse quality beets the polarimetric determinations differ greatly from isotopic data.

  4. Chromothripsis Detection and Characterization Using the CTLPScanner Web Server.

    Science.gov (United States)

    Yang, Jian; Liu, Bo; Cai, Haoyang

    2018-01-01

    Accurate detection of chromothripsis event is important to study the mechanisms underlying this phenomenon. CTLPScanner ( http://cgma.scu.edu.cn/CTLPScanner/ ) is a web-based tool for identification and annotation of chromothripsis-like pattern (CTLP) in genomic array data. In this chapter, we illustrate the utility of CTLPScanner for screening chromosome pulverization regions and give interpretation of the results. The web interface offers a set of parameters and thresholds for customized screening. We also provide practical recommendations for effective chromothripsis detection. In addition to the user data processing module, CTLPScanner contains more than 50,000 preprocessed oncogenomic arrays, which allow users to explore the presence of chromothripsis signatures from public data resources.

  5. SPECTROSCOPIC CHARACTERIZATION AND DETECTION OF ETHYL MERCAPTAN IN ORION

    International Nuclear Information System (INIS)

    Kolesniková, L.; Alonso, J. L.; Daly, A. M.; Tercero, B.; Cernicharo, J.; Gordon, B. P.; Shipman, S. T.

    2014-01-01

    New laboratory data of ethyl mercaptan, CH 3 CH 2 SH, in the millimeter- and submillimeter-wave domains (up to 880 GHz) provided very precise values of the spectroscopic constants that allowed the detection of gauche-CH 3 CH 2 SH toward Orion KL. This identification is supported by 77 unblended or slightly blended lines plus no missing transitions in the range 80-280 GHz. A detection of methyl mercaptan, CH 3 SH, in the spectral survey of Orion KL is reported as well. Our column density results indicate that methyl mercaptan is ≅ 5 times more abundant than ethyl mercaptan in the hot core of Orion KL

  6. SPECTROSCOPIC CHARACTERIZATION AND DETECTION OF ETHYL MERCAPTAN IN ORION

    Energy Technology Data Exchange (ETDEWEB)

    Kolesniková, L.; Alonso, J. L.; Daly, A. M. [Grupo de Espectroscopía Molecular (GEM), Edificio Quifima, Laboratorios de Espectroscopía y Bioespectroscopía, Parque Científico UVa, Unidad Asociada CSIC, Universidad de Valladolid, E-47011 Valladolid (Spain); Tercero, B.; Cernicharo, J. [Departamento de Astrofísica, Centro de Astrobiología CAB, CSIC-INTA, Ctra. de Torrejón a Ajalvir km 4, E-28850 Madrid (Spain); Gordon, B. P.; Shipman, S. T., E-mail: lucie.kolesnikova@uva.es, E-mail: jlalonso@qf.uva.es, E-mail: adammichael.daly@uva.es, E-mail: terceromb@cab.inta-csic.es, E-mail: jcernicharo@cab.inta-csic.es, E-mail: brittany.gordon@ncf.edu, E-mail: shipman@ncf.edu [Division of Natural Sciences, New College of Florida, Sarasota, FL 34243 (United States)

    2014-03-20

    New laboratory data of ethyl mercaptan, CH{sub 3}CH{sub 2}SH, in the millimeter- and submillimeter-wave domains (up to 880 GHz) provided very precise values of the spectroscopic constants that allowed the detection of gauche-CH{sub 3}CH{sub 2}SH toward Orion KL. This identification is supported by 77 unblended or slightly blended lines plus no missing transitions in the range 80-280 GHz. A detection of methyl mercaptan, CH{sub 3}SH, in the spectral survey of Orion KL is reported as well. Our column density results indicate that methyl mercaptan is ≅ 5 times more abundant than ethyl mercaptan in the hot core of Orion KL.

  7. Acoustic detection in superconducting magnets for performance characterization and diagnostics

    OpenAIRE

    Marchevsky, M.; Wang, X.; Sabbi, G.; Prestemon, S.

    2014-01-01

    Quench diagnostics in superconducting accelerator magnets is essential for understanding performance limitations and improving magnet design. Applicability of the conventional quench diagnostics methods such as voltage taps or quench antennas is limited for long magnets or complex winding geometries, and alternative approaches are desirable. Here, we discuss acoustic sensing technique for detecting mechanical vibrations in superconducting magnets. Using LARP high-field Nb3Sn quadrupole HQ01 [...

  8. Detecting and Characterizing Nighttime Lighting Using Multispectral and Hyperspectral Imaging

    Science.gov (United States)

    2012-12-01

    are a wide variety of statistically based methods for analysis of MSI data, but they can also be analyzed to some degree using MSI spectral signatures...the received signal for the detection of clouds at night using moonlight . The implementation of the PMT system allowed for an unintentional ability...been known since the 1970s, the early night-time mapping products were derived from analog data ( film ). Elvidge et al. (1997) presented the first

  9. Design and development of a microwave multifrequency polarimetric scatterometer for biosphere remote sensing

    International Nuclear Information System (INIS)

    Stjernman, A.

    1995-05-01

    The main topic of this research report is the design and development of a multifrequency, polarimetric scatterometer for biosphere remote sensing. The system was developed using a standard HP network analyzer, a crossed log-periodic dipole antenna and a reflector. The scatterometer functions in a linear polarization basis between the L- and X-bands and gathers full-polarimetric information. The standard S-parameter measurements using the network analyzer were related to surface and volume scattering coefficients of rough surface, snow cover and vegetation media. The scatterometer measurements were carried out in the frequency domain to make use of narrow band filters in the receiver chain. The fast Fourier transform was used to convert the frequency domain measurements to the time domain. The range resolution of the system was 20 cm; azimuthal and elevation resolutions are determined by the antenna beam widths. Range side lobes were reduced by making use of appropriate weighting (Kaiser-Bessel window) functions. The accuracy of target characterization depends on the quality of scatterometer calibration. A novel technique to estimate the absolute gain and crosstalk of the radar system was developed. Using a distortion matrix approach, the cross-polarization response of the system was improved by 10 to 25 dB. The radar measurements were validated by comparing point target radar observations with the corresponding theoretical values. Also, measurements of fading decorrelation distance and decorrelation bandwidth or rough surfaces were in good agreement with the theory. Backscatter observations of vegetation and snow cover were comparable to earlier published values for a similar environment. 50 refs, 56 figs, 1 tab

  10. Design and development of a microwave multifrequency polarimetric scatterometer for biosphere remote sensing

    Energy Technology Data Exchange (ETDEWEB)

    Stjernman, A

    1995-05-01

    The main topic of this research report is the design and development of a multifrequency, polarimetric scatterometer for biosphere remote sensing. The system was developed using a standard HP network analyzer, a crossed log-periodic dipole antenna and a reflector. The scatterometer functions in a linear polarization basis between the L- and X-bands and gathers full-polarimetric information. The standard S-parameter measurements using the network analyzer were related to surface and volume scattering coefficients of rough surface, snow cover and vegetation media. The scatterometer measurements were carried out in the frequency domain to make use of narrow band filters in the receiver chain. The fast Fourier transform was used to convert the frequency domain measurements to the time domain. The range resolution of the system was 20 cm; azimuthal and elevation resolutions are determined by the antenna beam widths. Range side lobes were reduced by making use of appropriate weighting (Kaiser-Bessel window) functions. The accuracy of target characterization depends on the quality of scatterometer calibration. A novel technique to estimate the absolute gain and crosstalk of the radar system was developed. Using a distortion matrix approach, the cross-polarization response of the system was improved by 10 to 25 dB. The radar measurements were validated by comparing point target radar observations with the corresponding theoretical values. Also, measurements of fading decorrelation distance and decorrelation bandwidth or rough surfaces were in good agreement with the theory. Backscatter observations of vegetation and snow cover were comparable to earlier published values for a similar environment. 50 refs, 56 figs, 1 tab.

  11. Characterizing individual painDETECT symptoms by average pain severity

    Directory of Open Access Journals (Sweden)

    Sadosky A

    2016-07-01

    Full Text Available Alesia Sadosky,1 Vijaya Koduru,2 E Jay Bienen,3 Joseph C Cappelleri4 1Pfizer Inc, New York, NY, 2Eliassen Group, New London, CT, 3Outcomes Research Consultant, New York, NY, 4Pfizer Inc, Groton, CT, USA Background: painDETECT is a screening measure for neuropathic pain. The nine-item version consists of seven sensory items (burning, tingling/prickling, light touching, sudden pain attacks/electric shock-type pain, cold/heat, numbness, and slight pressure, a pain course pattern item, and a pain radiation item. The seven-item version consists only of the sensory items. Total scores of both versions discriminate average pain-severity levels (mild, moderate, and severe, but their ability to discriminate individual item severity has not been evaluated.Methods: Data were from a cross-sectional, observational study of six neuropathic pain conditions (N=624. Average pain severity was evaluated using the Brief Pain Inventory-Short Form, with severity levels defined using established cut points for distinguishing mild, moderate, and severe pain. The Wilcoxon rank sum test was followed by ridit analysis to represent the probability that a randomly selected subject from one average pain-severity level had a more favorable outcome on the specific painDETECT item relative to a randomly selected subject from a comparator severity level.Results: A probability >50% for a better outcome (less severe pain was significantly observed for each pain symptom item. The lowest probability was 56.3% (on numbness for mild vs moderate pain and highest probability was 76.4% (on cold/heat for mild vs severe pain. The pain radiation item was significant (P<0.05 and consistent with pain symptoms, as well as with total scores for both painDETECT versions; only the pain course item did not differ.Conclusion: painDETECT differentiates severity such that the ability to discriminate average pain also distinguishes individual pain item severity in an interpretable manner. Pain

  12. Meal Microstructure Characterization from Sensor-Based Food Intake Detection

    Directory of Open Access Journals (Sweden)

    Abul Doulah

    2017-07-01

    Full Text Available To avoid the pitfalls of self-reported dietary intake, wearable sensors can be used. Many food ingestion sensors offer the ability to automatically detect food intake using time resolutions that range from 23 ms to 8 min. There is no defined standard time resolution to accurately measure ingestive behavior or a meal microstructure. This paper aims to estimate the time resolution needed to accurately represent the microstructure of meals such as duration of eating episode, the duration of actual ingestion, and number of eating events. Twelve participants wore the automatic ingestion monitor (AIM and kept a standard diet diary to report their food intake in free-living conditions for 24 h. As a reference, participants were also asked to mark food intake with a push button sampled every 0.1 s. The duration of eating episodes, duration of ingestion, and number of eating events were computed from the food diary, AIM, and the push button resampled at different time resolutions (0.1–30s. ANOVA and multiple comparison tests showed that the duration of eating episodes estimated from the diary differed significantly from that estimated by the AIM and the push button (p-value <0.001. There were no significant differences in the number of eating events for push button resolutions of 0.1, 1, and 5 s, but there were significant differences in resolutions of 10–30s (p-value <0.05. The results suggest that the desired time resolution of sensor-based food intake detection should be ≤5 s to accurately detect meal microstructure. Furthermore, the AIM provides more accurate measurement of the eating episode duration than the diet diary.

  13. Acoustic detection in superconducting magnets for performance characterization and diagnostics

    International Nuclear Information System (INIS)

    Marchevsky, M; Wang, X; Sabbi, G; Prestemon, S

    2013-01-01

    Quench diagnostics in superconducting accelerator magnets is essential for understanding performance limitations and improving magnet design. Applicability of the conventional quench diagnostics methods such as voltage taps or quench antennas is limited for long magnets or complex winding geometries, and alternative approaches are desirable. Here, we discuss acoustic sensing technique for detecting mechanical vibrations in superconducting magnets. Using LARP high-field Nb3Sn quadrupole HQ01, we show how acoustic data is connected with voltage instabilities measured simultaneously in the magnet windings during provoked extractions and current ramps to quench. Instrumentation and data analysis techniques for acoustic sensing are reviewed. (author)

  14. Acoustic detection in superconducting magnets for performance characterization and diagnostics

    CERN Document Server

    Marchevsky, M.; Sabbi, G.; Prestemon, S.

    2013-01-01

    Quench diagnostics in superconducting accelerator magnets is essential for understanding performance limitations and improving magnet design. Applicability of the conventional quench diagnostics methods such as voltage taps or quench antennas is limited for long magnets or complex winding geometries, and alternative approaches are desirable. Here, we discuss acoustic sensing technique for detecting mechanical vibrations in superconducting magnets. Using LARP high-field Nb$_{3}$Sn quadrupole HQ01 [1], we show how acoustic data is connected with voltage instabilities measured simultaneously in the magnet windings during provoked extractions and current ramps to quench. Instrumentation and data analysis techniques for acoustic sensing are reviewed.

  15. Strontium vanadate nanoribbons: Synthesis, characterization and detection of dopamine

    International Nuclear Information System (INIS)

    Zhou, Qing; Shao, Mingwang; Chen, Tao; Xu, Hongyan

    2010-01-01

    Large-scale, high-purity and uniform strontium vanadate (Sr 2 V 2 O 7 ) nanoribbons were easily synthesized via a hydrothermal process without any surfactants. The as-prepared products were up to hundreds of micrometers in length, 200-600 nm in width, and 20 nm in thickness. These nanomaterials were employed to modify glassy carbon electrode, which displayed excellent electrochemical sensitivity in detecting dopamine in the presence of ascorbic acid. A linear relationship between the concentrations of dopamine and its oxidation peak currents was obtained. The modified electrode exhibited high reproducibility and stability, which might be found potential application in the biosensors.

  16. Dual-gas tracers for subsurface characterization and NAPL detection

    International Nuclear Information System (INIS)

    Gauglitz, P.A.; Peurrung, L.M.; Mendoza, D.P.; Pillay, G.

    1994-11-01

    Effective design of in situ remediation technologies often requires an understanding of the mass transfer limitations that control the removal of contaminants from the soil. In addition, the presence of nonaqueous phase liquids (NAPLs) in soils will affect the ultimate success or failure of remediation processes. Knowing the location of NAPLs within the subsurface is critical to designing the most effective remediation approach. This work focuses on demonstrating that gas tracers can detect the location of the NAPLs in the subsurface and elucidating the mass transfer limitations associated with the removal of contaminants from soils

  17. Polarimetric purity and the concept of degree of polarization

    Science.gov (United States)

    Gil, José J.; Norrman, Andreas; Friberg, Ari T.; Setälä, Tero

    2018-02-01

    The concept of degree of polarization for electromagnetic waves, in its general three-dimensional version, is revisited in the light of the implications of the recent findings on the structure of polarimetric purity and of the existence of nonregular states of polarization [J. J. Gil et al., Phys Rev. A 95, 053856 (2017), 10.1103/PhysRevA.95.053856]. From the analysis of the characteristic decomposition of a polarization matrix R into an incoherent convex combination of (1) a pure state Rp, (2) a middle state Rm given by an equiprobable mixture of two eigenstates of R, and (3) a fully unpolarized state Ru -3 D, it is found that, in general, Rm exhibits nonzero circular and linear degrees of polarization. Therefore, the degrees of linear and circular polarization of R cannot always be assigned to the single totally polarized component Rp. It is shown that the parameter P3 D proposed formerly by Samson [J. C. Samson, Geophys. J. R. Astron. Soc. 34, 403 (1973), 10.1111/j.1365-246X.1973.tb02404.x] takes into account, in a proper and objective form, all the contributions to polarimetric purity, namely, the contributions to the linear and circular degrees of polarization of R as well as to the stability of the plane containing its polarization ellipse. Consequently, P3 D constitutes a natural representative of the degree of polarimetric purity. Some implications for the common convention for the concept of two-dimensional degree of polarization are also analyzed and discussed.

  18. Rapid detection, characterization, and enumeration of foodborne pathogens.

    Science.gov (United States)

    Hoorfar, J

    2011-11-01

    As food safety management further develops, microbiological testing will continue to play an important role in assessing whether Food Safety Objectives are achieved. However, traditional microbiological culture-based methods are limited, particularly in their ability to provide timely data. The present review discusses the reasons for the increasing interest in rapid methods, current developments in the field, the research needs, and the future trends. The advent of biotechnology has introduced new technologies that led to the emergence of rapid diagnostic methods and altered food testing practices. Rapid methods are comprised of many different detection technologies, including specialized enzyme substrates, antibodies and DNA, ranging from simple differential plating media to the use of sophisticated instruments. The use of non-invasive sampling techniques for live animals especially came into focus with the 1990s outbreak of bovine spongiform encephalopathy that was linked to the human outbreak of Creutzfeldt Jakob's Disease. Serology is still an important tool in preventing foodborne pathogens to enter the human food supply through meat and milk from animals. One of the primary uses of rapid methods is for fast screening of large number of samples, where most of them are expected to be test-negative, leading to faster product release for sale. This has been the main strength of rapid methods such as real-time Polymerase Chain Reaction (PCR). Enrichment PCR, where a primary culture broth is tested in PCR, is the most common approach in rapid testing. Recent reports show that it is possible both to enrich a sample and enumerate by pathogen-specific real-time PCR, if the enrichment time is short. This can be especially useful in situations where food producers ask for the level of pathogen in a contaminated product. Another key issue is automation, where the key drivers are miniaturization and multiple testing, which mean that not only one instrument is flexible

  19. Detection and Characterization of Bacterial Proteinases Using Zymography.

    Science.gov (United States)

    Madanan, Madathiparambil G; Mechoor, Ambili

    2017-01-01

    Proteinases play a crucial role in invasion and pathogenesis of bacteria, especially the extracellular and membrane-bound forms. Analysis of these proteinases demands the isolation by retaining the enzymatic activity. The isolation procedures maintaining the native structure of the enzyme in its soluble form are also of extreme importance. The qualitative analyses of these proteinases are carried out by electrophoresis and zymography. Enzymatic characterization based on the effect of inhibitors and activators on gelatinase activity also can be assessed using this zymography. The membrane-bound proteinases can be isolated in their native and soluble form, still retaining the activity using 6-aminocaproic acid and sodium deoxycholate; the procedure of which is explained in this chapter.

  20. TCT characterization of different semiconductor materials for particle detection

    International Nuclear Information System (INIS)

    Fink, J.; Lodomez, P.; Krueger, H.; Pernegger, H.; Weilhammer, P.; Wermes, N.

    2006-01-01

    The development of digital semiconductor based X-ray detectors necessitates a detailed understanding of the applied sensor material. Under this premise a broad-band transient current technique (TCT) setup has been developed and used to characterize different semiconductors. The measurements are based on the generation of electrical charges within the sensor material and the subsequent time-resolved analysis of the charge carrier movement. From the recorded current pulses the charge collection efficiency, the charge carrier mobility and the electric field profile have been extracted. The examined materials are silicon p in n diodes, ohmic and Schottky contacted CdTe detectors, CdZnTe (CZT) crystals with Schottky contacts as well as two single-crystal CVD-diamonds

  1. Single particle detection and characterization of synuclein co-aggregation

    International Nuclear Information System (INIS)

    Giese, Armin; Bader, Benedikt; Bieschke, Jan; Schaffar, Gregor; Odoy, Sabine; Kahle, Philipp J.; Haass, Christian; Kretzschmar, Hans

    2005-01-01

    Protein aggregation is the key event in a number of human diseases such as Alzheimer's and Parkinson's disease. We present a general method to quantify and characterize protein aggregates by dual-colour scanning for intensely fluorescent targets (SIFT). In addition to high sensitivity, this approach offers a unique opportunity to study co-aggregation processes. As the ratio of two fluorescently labelled components can be analysed for each aggregate separately in a homogeneous assay, the molecular composition of aggregates can be studied even in samples containing a mixture of different types of aggregates. Using this method, we could show that wild-type α-synuclein forms co-aggregates with a mutant variant found in familial Parkinson's disease. Moreover, we found a striking increase in aggregate formation at non-equimolar mixing ratios, which may have important therapeutic implications, as lowering the relative amount of aberrant protein may cause an increase of protein aggregation leading to adverse effects

  2. Optimized microviscosimeter for detection and characterization of biological vesicles

    International Nuclear Information System (INIS)

    Gaiffe, O; Cretin, B; Boireau, W; Baudouy, J C; Vairac, P

    2008-01-01

    In this paper, we report on studies aimed at sensing the stiffness of biological membranes, in particular in the case of lipidic vesicles. To obtain pertinent results, we have developed and checked a specific sensor based on a vibrating sphere. The near-field acoustic wave generated by this vibrating sphere enables us to characterize biological particles which change the apparent viscosity and density of the surrounding fluid. The microsphere is well suited for very small volumes of liquid (typically about a few microlitres). The experimental results demonstrate the high sensitivity of the sensor to small variations of the composition of the aqueous media, particularly in the case of various populations of lipidic nanoparticles. Finally, this microviscosimeter demonstrates its ability to discriminate the population of vesicles on the basis of their global viscous properties

  3. Using polarimetry to detect and characterize Jupiter-like extrasolar planets

    NARCIS (Netherlands)

    Stam, D.M.; Hovenier, J.W.; Waters, L.B.F.M.

    2004-01-01

    Using numerical simulations of flux and polarization spectra of visible to near-infrared starlight reflected by Jupiter-like extrasolar planets, we show that polarimetry can be used both for the detection and for the characterization of extrasolar planets. Polarimetry is valuable for detection

  4. Application of thermometric methods for detection and characterization of leakages in embankment dams

    Energy Technology Data Exchange (ETDEWEB)

    Beck, Y.L.; Cunat, P.; Fry, J.J. [EDF, Grenoble (France); Faure, Y.H. [LTHE, Saint Martin d' Heres (France)

    2010-07-01

    The earliest possible detection of leakages in dikes is essential. Distributed temperature measurements using fibre optics allow the monitoring of large sections of the dike with a high spatial and temperature resolution. This paper presented the application of thermometric methods for detection and characterization of leakage in embankment dams. After a brief description of the system used, its application on a controlled experimental site and an EDF industrial site instrumented with fibre optics was presented. The instrumentation is complemented by installation of local temperature and pressure sensors in the piezometers for complete characterization of the detected leakages. The analysis of the results data clearly allowed detecting the leakages. The vertical location, intensity and location of the detected leakages were also identified. It was found that thermometry is potentially very powerful for detecting leaks and as a diagnostic tool.

  5. Quantum non-Markovianity: characterization, quantification and detection

    International Nuclear Information System (INIS)

    Rivas, Ángel; Huelga, Susana F; Plenio, Martin B

    2014-01-01

    We present a comprehensive and up-to-date review of the concept of quantum non-Markovianity, a central theme in the theory of open quantum systems. We introduce the concept of a quantum Markovian process as a generalization of the classical definition of Markovianity via the so-called divisibility property and relate this notion to the intuitive idea that links non-Markovianity with the persistence of memory effects. A detailed comparison with other definitions presented in the literature is provided. We then discuss several existing proposals to quantify the degree of non-Markovianity of quantum dynamics and to witness non-Markovian behavior, the latter providing sufficient conditions to detect deviations from strict Markovianity. Finally, we conclude by enumerating some timely open problems in the field and provide an outlook on possible research directions. (review article)

  6. Quantum non-Markovianity: characterization, quantification and detection

    Science.gov (United States)

    Rivas, Ángel; Huelga, Susana F.; Plenio, Martin B.

    2014-09-01

    We present a comprehensive and up-to-date review of the concept of quantum non-Markovianity, a central theme in the theory of open quantum systems. We introduce the concept of a quantum Markovian process as a generalization of the classical definition of Markovianity via the so-called divisibility property and relate this notion to the intuitive idea that links non-Markovianity with the persistence of memory effects. A detailed comparison with other definitions presented in the literature is provided. We then discuss several existing proposals to quantify the degree of non-Markovianity of quantum dynamics and to witness non-Markovian behavior, the latter providing sufficient conditions to detect deviations from strict Markovianity. Finally, we conclude by enumerating some timely open problems in the field and provide an outlook on possible research directions.

  7. Detection and Molecular Characterization of Grapevine Virus A in Jordan

    Directory of Open Access Journals (Sweden)

    G. Anfoka

    2004-12-01

    Full Text Available In a study on grapevines in Jordan conducted between 2002 and 2003, grapevine virus A (GVA was detected in all areas where grapevines were planted. DAS-ELISA analysis of samples from symptomatic trees found that 16.1% of samples were infected with GVA. Using a GVA- specific primer pair (H587/C995, a portion of the coat protein gene of the virus was amplified by IC-RT-PCR and RT-PCR, using leaf extracts and RNA extracted from infected grapevines respectively. After cloning and sequencing the coat protein gene of the Jordanian isolate of GVA (GVA-Jo, the sequence of the amplified product was compared with sequences of other GVA isolates from different countries.

  8. Rapid detection, characterization, and enumeration of foodborne pathogens

    DEFF Research Database (Denmark)

    Hoorfar, Jeffrey

    2011-01-01

    . The present review discusses the reasons for the increasing interest in rapid methods; current developments in the field, the research needs, and the future trends. The advent of biotechnology has introduced new technologies that led to the emergence of rapid diagnostic methods and altered food testing...... of rapid methods is for fast screening of large number of samples, where most of them are expected to be test-negative, leading to faster product release for sale. This has been the main strength of rapid methods such as real-time Polymerase Chain Reaction (PCR). Enrichment PCR, where a primary culture...... of pathogen in a contaminated product. Another key issue is automation, where the key drivers are miniaturization and multiple testing, which mean that not only one instrument is flexible enough to test for many pathogens but also many pathogens can be detected with one test. The review is mainly based...

  9. Safeguards: Modelling of the Detection and Characterization of Nuclear Materials

    International Nuclear Information System (INIS)

    Enqvist, Andreas

    2010-01-01

    Nuclear safeguards is a collective term for the tools and methods needed to ensure nonproliferation and safety in connection to utilization of nuclear materials. It encompasses a variety of concepts from legislation to measurement equipment. The objective of this thesis is to present a number of research results related to nuclear materials control and accountability, especially the area of nondestructive assay. Physical aspects of nuclear materials are often the same as for materials encountered in everyday life. One special aspect though is that nuclear materials also emit radiation allowing them to be qualitatively and quantitatively measured without direct interaction with the material. For the successful assay of the material, the particle generation and detection needs to be well understood, and verified with measurements, simulations and models. Four topics of research are included in the thesis. First the generation and multiplication of neutrons and gamma rays in a fissile multiplying sample is treated. The formalism used enables investigation of the number of generated, absorbed and detected particles, offering understanding of the different processes involved. Secondly, the issue of relating the coincident detector signals, generated by both neutrons and gamma rays, to sample parameters is dealt with. Fission rate depends directly on the sample mass, while parameters such as neutron generation by alpha decay and neutron leakage multiplication are parameters that depend on the size, composition and geometry of the sample. Artificial neural networks are utilized to solve the inverse problem of finding sample characteristics from the measured rates of particle multiples. In the third part the interactions between neutrons and organic scintillation detectors are treated. The detector material consists of hydrogen and carbon, on which the neutrons scatter and transfer energy. The problem shares many characteristics with the area of neutron moderation found in

  10. On the Detection and Characterization of Polluted White Dwarfs

    Science.gov (United States)

    Steele, Amy; Debes, John H.; Deming, Drake

    2017-06-01

    There is evidence of circumstellar material around main sequence, giant, and white dwarf stars. What happens to this material after the main sequence? With this work, we focus on the characterization of the material around WD 1145+017. The goals are to monitor the white dwarf—which has a transiting, disintegrating planetesimal and determine the composition of the evaporated material for that same white dwarf by looking at high-resolution spectra. We also present preliminary results of follow-up photometric observations of known polluted WDs. If rocky bodies survive red giant branch evolution, then the material raining down on a WD atmosphere is a direct probe of main sequence cosmochemistry. If rocky bodies do not survive the evolution, then this informs the degree of post-main-sequence processing. These case studies will provide the community with further insight about debris disk modeling, the degree of post-main-sequence processing of circumstellar material, and the composition of a disintegrating planetesimal.

  11. FFTF fuel failure detection and characterization by cover gas monitoring. Final report

    International Nuclear Information System (INIS)

    Miller, W.C.; Holt, F.E.

    1977-01-01

    The Fast Flux Test Facility (FFTF) will include a Fuel Failure Monitoring (FFM) System designed to detect, characterize, and locate fuel and absorber pin failures (i.e., cladding breaches) using a combination of delayed neutron detection, cover gas radioisotope monitoring, and gas tagging. During the past several years the Hanford Engineering Development Laboratory has been involved in the development, design, procurement, and installation of this integrated system. The paper describes one portion of the FFM System, the Cover Gas Monitoring System (CGMS), which has the primary function of fuel failure detection and characterization in the FFTF. By monitoring the various radioisotopes in the cover gas, the CGMS will both detect fuel and absorber pin failures and characterize those failures as to magnitude and severity

  12. Acoustic detection, tracking, and characterization of three tornadoes.

    Science.gov (United States)

    Frazier, William Garth; Talmadge, Carrick; Park, Joseph; Waxler, Roger; Assink, Jelle

    2014-04-01

    Acoustic data recorded at 1000 samples per second by two sensor arrays located at ranges of 1-113 km from three tornadoes that occurred on 24 May 2011 in Oklahoma are analyzed. Accurate bearings to the tornadoes have been obtained using beamforming methods applied to the data at infrasonic frequencies. Beamforming was not viable at audio frequencies, but the data demonstrate the ability to detect significant changes in the shape of the estimated power spectral density in the band encompassing 10 Hz to approximately 100 Hz at distances of practical value from the sensors. This suggests that arrays of more closely spaced sensors might provide better bearing accuracy at practically useful distances from a tornado. Additionally, a mathematical model, based on established relationships of aeroacoustic turbulence, is demonstrated to provide good agreement to the estimated power spectra produced by the tornadoes at different times and distances from the sensors. The results of this analysis indicate that, qualitatively, an inverse relationship appears to exist between the frequency of an observed peak of the power spectral density and the reported tornado intensity.

  13. HABITABLE PLANETS ECLIPSING BROWN DWARFS: STRATEGIES FOR DETECTION AND CHARACTERIZATION

    International Nuclear Information System (INIS)

    Belu, Adrian R.; Selsis, Franck; Raymond, Sean N.; Bolmont, Emeline; Pallé, Enric; Street, Rachel; Sahu, D. K.; Anupama, G. C.; Von Braun, Kaspar; Figueira, Pedro; Ribas, Ignasi

    2013-01-01

    Given the very close proximity of their habitable zones, brown dwarfs (BDs) represent high-value targets in the search for nearby transiting habitable planets that may be suitable for follow-up occultation spectroscopy. In this paper, we develop search strategies to find habitable planets transiting BDs depending on their maximum habitable orbital period (P HZ o ut ). Habitable planets with P HZ o ut shorter than the useful duration of a night (e.g., 8-10 hr) can be screened with 100% completeness from a single location and in a single night (near-IR). More luminous BDs require continuous monitoring for longer duration, e.g., from space or from a longitude-distributed network (one test scheduling achieved three telescopes, 13.5 contiguous hours). Using a simulated survey of the 21 closest known BDs (within 7 pc) we find that the probability of detecting at least one transiting habitable planet is between 4.5 +5.6 -1.4 % and 56 +31 -13 %, depending on our assumptions. We calculate that BDs within 5-10 pc are characterizable for potential biosignatures with a 6.5 m space telescope using ∼1% of a five-year mission's lifetime spread over a contiguous segment only one-fifth to one-tenth of this duration.

  14. HABITABLE PLANETS ECLIPSING BROWN DWARFS: STRATEGIES FOR DETECTION AND CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Belu, Adrian R.; Selsis, Franck; Raymond, Sean N.; Bolmont, Emeline [Universite de Bordeaux, LAB, UMR 5804, F-33270, Floirac (France); Palle, Enric [Instituto de Astrofisica de Canarias, E-38205 La Laguna (Spain); Street, Rachel [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Goleta, CA 93117 (United States); Sahu, D. K.; Anupama, G. C. [Indian Institute of Astrophysics, Koramangala, Bangalore 560034 (India); Von Braun, Kaspar [NASA Exoplanet Science Institute, California Institute of Technology, MC 100-22, Pasadena, CA 91125 (United States); Figueira, Pedro [Centro de Astrofisica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Ribas, Ignasi, E-mail: belu@obs.u-bordeaux1.fr [Institut de Ciencies de l' Espai (CSIC-IEEC), Campus UAB, Facultat de Ciencies, Torre C5, parell, 2a pl., E-08193 Bellaterra (Spain)

    2013-05-10

    Given the very close proximity of their habitable zones, brown dwarfs (BDs) represent high-value targets in the search for nearby transiting habitable planets that may be suitable for follow-up occultation spectroscopy. In this paper, we develop search strategies to find habitable planets transiting BDs depending on their maximum habitable orbital period (P{sub HZ{sub out}}). Habitable planets with P{sub HZ{sub out}} shorter than the useful duration of a night (e.g., 8-10 hr) can be screened with 100% completeness from a single location and in a single night (near-IR). More luminous BDs require continuous monitoring for longer duration, e.g., from space or from a longitude-distributed network (one test scheduling achieved three telescopes, 13.5 contiguous hours). Using a simulated survey of the 21 closest known BDs (within 7 pc) we find that the probability of detecting at least one transiting habitable planet is between 4.5{sup +5.6}{sub -1.4}% and 56{sup +31}{sub -13}%, depending on our assumptions. We calculate that BDs within 5-10 pc are characterizable for potential biosignatures with a 6.5 m space telescope using {approx}1% of a five-year mission's lifetime spread over a contiguous segment only one-fifth to one-tenth of this duration.

  15. Three Dimensional Polarimetric Neutron Tomography of Magnetic Fields

    DEFF Research Database (Denmark)

    Sales, Morten; Strobl, Markus; Shinohara, Takenao

    2018-01-01

    Through the use of Time-of-Flight Three Dimensional Polarimetric Neutron Tomography (ToF 3DPNT) we have for the first time successfully demonstrated a technique capable of measuring and reconstructing three dimensional magnetic field strengths and directions unobtrusively and non-destructively wi......Through the use of Time-of-Flight Three Dimensional Polarimetric Neutron Tomography (ToF 3DPNT) we have for the first time successfully demonstrated a technique capable of measuring and reconstructing three dimensional magnetic field strengths and directions unobtrusively and non...... and reconstructed, thereby providing the proof-of-principle of a technique able to reveal hitherto unobtainable information on the magnetic fields in the bulk of materials and devices, due to a high degree of penetration into many materials, including metals, and the sensitivity of neutron polarisation to magnetic...... fields. The technique puts the potential of the ToF time structure of pulsed neutron sources to full use in order to optimise the recorded information quality and reduce measurement time....

  16. G0-WISHART Distribution Based Classification from Polarimetric SAR Images

    Science.gov (United States)

    Hu, G. C.; Zhao, Q. H.

    2017-09-01

    Enormous scientific and technical developments have been carried out to further improve the remote sensing for decades, particularly Polarimetric Synthetic Aperture Radar(PolSAR) technique, so classification method based on PolSAR images has getted much more attention from scholars and related department around the world. The multilook polarmetric G0-Wishart model is a more flexible model which describe homogeneous, heterogeneous and extremely heterogeneous regions in the image. Moreover, the polarmetric G0-Wishart distribution dose not include the modified Bessel function of the second kind. It is a kind of simple statistical distribution model with less parameter. To prove its feasibility, a process of classification has been tested with the full-polarized Synthetic Aperture Radar (SAR) image by the method. First, apply multilook polarimetric SAR data process and speckle filter to reduce speckle influence for classification result. Initially classify the image into sixteen classes by H/A/α decomposition. Using the ICM algorithm to classify feature based on the G0-Wshart distance. Qualitative and quantitative results show that the proposed method can classify polaimetric SAR data effectively and efficiently.

  17. Generalized Calibration of the Polarimetric Albedo Scale of Asteroids

    Science.gov (United States)

    Lupishko, D. F.

    2018-03-01

    Six different calibrations of the polarimetric albedo scale of asteroids have been published so far. Each of them contains its particular random and systematic errors and yields its values of geometric albedo. On the one hand, this complicates their analysis and comparison; on the other hand, it becomes more and more difficult to decide which of the proposed calibrations should be used. Moreover, in recent years, new databases on the albedo of asteroids obtained from the radiometric surveys of the sky with the orbital space facilities (the InfraRed Astronomical Satellite (IRAS), the Japanese astronomical satellite AKARI (which means "light"), the Wide-field Infrared Survey Explorer (WISE), and the Near-Earth Object Wide-field Survey Explorer (NEOWISE)) have appeared; and the database on the diameters and albedos of asteroids obtained from their occultations of stars has substantially increased. Here, we critically review the currently available calibrations and propose a new generalized calibration derived from the interrelations between the slope h and the albedo and between P min and the albedo. This calibration is based on all of the available series of the asteroid albedos and the most complete data on the polarization parameters of asteroids. The generalized calibration yields the values of the polarimetric albedo of asteroids in the system unified with the radiometric albedos and the albedos obtained from occultations of stars by asteroids. This, in turn, removes the difficulties in their comparison, joint analysis, etc.

  18. Estimating soil moisture using the Danish polarimetric SAR

    DEFF Research Database (Denmark)

    Jiankang, Ji; Thomsen, A.; Skriver, Henning

    1995-01-01

    The results of applying data from the Danish polarimetric SAR (EMISAR) to estimate soil moisture for bare fields are presented. Fully calibrated C-band SAR images for hh, vv and cross polarizations have been used in this study. The measured surface roughness data showed that classical roughness a...... of surface parameters with the bilinear model, the correlation coefficient between the estimated and measured soil moisture, as well as rms height, is about 0.77. To improve the result, the local incidence angles need to be taken into account......The results of applying data from the Danish polarimetric SAR (EMISAR) to estimate soil moisture for bare fields are presented. Fully calibrated C-band SAR images for hh, vv and cross polarizations have been used in this study. The measured surface roughness data showed that classical roughness...... autocorrelation functions (Gaussian and Exponential) were not able to fit natural surfaces well. A Gauss-Exp hybrid model which agreed better with the measured data has been proposed. Theoretical surface scattering models (POM, IEM), as well as an empirical model for retrieval of soil moisture and surface rms...

  19. Multi-Frequency Polarimetric SAR Classification Based on Riemannian Manifold and Simultaneous Sparse Representation

    Directory of Open Access Journals (Sweden)

    Fan Yang

    2015-07-01

    Full Text Available Normally, polarimetric SAR classification is a high-dimensional nonlinear mapping problem. In the realm of pattern recognition, sparse representation is a very efficacious and powerful approach. As classical descriptors of polarimetric SAR, covariance and coherency matrices are Hermitian semidefinite and form a Riemannian manifold. Conventional Euclidean metrics are not suitable for a Riemannian manifold, and hence, normal sparse representation classification cannot be applied to polarimetric SAR directly. This paper proposes a new land cover classification approach for polarimetric SAR. There are two principal novelties in this paper. First, a Stein kernel on a Riemannian manifold instead of Euclidean metrics, combined with sparse representation, is employed for polarimetric SAR land cover classification. This approach is named Stein-sparse representation-based classification (SRC. Second, using simultaneous sparse representation and reasonable assumptions of the correlation of representation among different frequency bands, Stein-SRC is generalized to simultaneous Stein-SRC for multi-frequency polarimetric SAR classification. These classifiers are assessed using polarimetric SAR images from the Airborne Synthetic Aperture Radar (AIRSAR sensor of the Jet Propulsion Laboratory (JPL and the Electromagnetics Institute Synthetic Aperture Radar (EMISAR sensor of the Technical University of Denmark (DTU. Experiments on single-band and multi-band data both show that these approaches acquire more accurate classification results in comparison to many conventional and advanced classifiers.

  20. Selective detection and characterization of nanoparticles from motor vehicles.

    Science.gov (United States)

    Johnston, Murray V; Klems, Joseph P; Zordan, Christopher A; Pennington, M Ross; Smith, James N

    2013-02-01

    Numerous studies have shown that exposure to motor vehicle emissions increases the probability of heart attacks, asthma attacks, and hospital visits among at-risk individuals. However, while many studies have focused on measurements of ambient nanoparticles near highways, they have not focused on specific road-level domains, such as intersections near population centers. At these locations, very intense spikes in particle number concentration have been observed. These spikes have been linked to motor vehicle activity and have the potential to increase exposure dramatically. Characterizing both the contribution and composition of these spikes is critical in developing exposure models and abatement strategies. To determine the contribution of the particle spikes to the ambient number concentration, we implemented wavelet-based algorithms to isolate the particle spikes from measurements taken during the summer and winter of 2009 in Wilmington, Delaware, adjacent to a roadway intersection that approximately 28,000 vehicles pass through daily. These measurements included both number concentration and size distributions recorded once every second by a condensation particle counter (CPC*; TSI, Inc., St. Paul, MN) and a fast mobility particle sizer (FMPS). The high-frequency portion of the signal, consisting of a series of abrupt spikes in number concentration that varied in length from a few seconds to tens of seconds, accounted for 3% to 35% of the daily ambient number concentration, with spike contributions sometimes greater than 50% of hourly number concentrations. When the data were weighted by particle volume, this portion of the signal contributed an average of 10% to 20% to the daily concentration of particulate matter (PM) vehicles accelerated after a red traffic light turned green. As the distance or transit time from emission to sampling increased, the size distribution shifted to a larger particle size, which confirmed the source assignments. To determine the

  1. Electro-Optical Method for polarimetric measurement

    International Nuclear Information System (INIS)

    Miranda Diaz, L. J.

    2011-01-01

    When passing a pulsing beam of polarized light of an LED or a semiconductor laser thru an optical system and two photodiodes spatially arranged at 900 to each other and both with their detection faces parallel to the transmission shaft of light, and polarization axis oriented at 450 of the vertices of the edges where the photodiodes join, in the outputs of two operational amplifiers, we have two signals with the same shape in time, i.e. a pulse train with the same phase, but when you turn the polarization plane, change the radiance of the light projected onto the photodiodes, being out of phase signals to the outputs of the amplifiers, where the difference between the fronts of the pulses is proportional to the angle of rotation of the plane of polarization of light. In a digital circuit phase discriminator, a pulse is obtained equal to the time difference between two sides of the rise in the output of two amplifiers. The width of this is directly proportional to the value of rotation the plane of polarization of light, that is, the greater the rotation, the greater the width of this pulse. (Author)

  2. Unsupervised Event Characterization and Detection in Multichannel Signals: An EEG application

    Directory of Open Access Journals (Sweden)

    Angel Mur

    2016-04-01

    Full Text Available In this paper, we propose a new unsupervised method to automatically characterize and detect events in multichannel signals. This method is used to identify artifacts in electroencephalogram (EEG recordings of brain activity. The proposed algorithm has been evaluated and compared with a supervised method. To this end an example of the performance of the algorithm to detect artifacts is shown. The results show that although both methods obtain similar classification, the proposed method allows detecting events without training data and can also be applied in signals whose events are unknown a priori. Furthermore, the proposed method provides an optimal window whereby an optimal detection and characterization of events is found. The detection of events can be applied in real-time.

  3. Detection and Characterization of Defects in Composite Materials Using Thermography

    Science.gov (United States)

    Silva, Antonio Jose Ramos

    The work described in this PhD Thesis focuses on the post-processing of optical fibers and their enhancement as sensing element. Since the majority of sensors presented are based in Fabry-Perot interferometers, an historical overview of this category of optical fiber sensors is firstly presented. This review considers the works published since the early years, in the beginning of the 1980s, until the middle of 2015. The incorporation of microcavities at the tip of a single mode fiber was extensively studied, particularly for the measurement of nitrogen and methane gas pressure. These cavities were fabricated using hollow core silica tubes and a hollow core photonic crystal fiber. Following a different approach, the microcavities were incorporated between two sections of single mode fiber. In this case, the low sensitivity to temperature makes these microcavities highly desirable for the measurement of strain at high temperatures. Competences in post-processing techniques such as the chemical etching and the writing of periodical structures in the fiber core by means of an excimer or a femtosecond laser were also acquired in the course of the PhD programme. One of the works consisted in the design and manufacturing of a double clad optical fiber. The refractive index of the inner cladding was higher than the one of the outer cladding and the core. Thus, light was guided in the inner cladding instead of propagating in the core. This situation was overcome by applying chemical etching, thus removing the inner cladding. The core, surrounded by air, was then able to guide light. Two different applications were found for this fiber, as a temperature sensor and as an optical refractometer. In the last, the optical phase changes with the liquid refractive index. Two different types of fiber Bragg gratings were characterized in strain and temperature. Sensing structures obtained through the phase mask technique at the tip of an optical fiber were subjected to chemical

  4. REMOVAL OF SPECTRO-POLARIMETRIC FRINGES BY TWO-DIMENSIONAL PATTERN RECOGNITION

    International Nuclear Information System (INIS)

    Casini, R.; Judge, P. G.; Schad, T. A.

    2012-01-01

    We present a pattern-recognition-based approach to the problem of the removal of polarized fringes from spectro-polarimetric data. We demonstrate that two-dimensional principal component analysis can be trained on a given spectro-polarimetric map in order to identify and isolate fringe structures from the spectra. This allows us, in principle, to reconstruct the data without the fringe component, providing an effective and clean solution to the problem. The results presented in this paper point in the direction of revising the way that science and calibration data should be planned for a typical spectro-polarimetric observing run.

  5. Statistics-based optimization of the polarimetric radar hydrometeor classification algorithm and its application for a squall line in South China

    Science.gov (United States)

    Wu, Chong; Liu, Liping; Wei, Ming; Xi, Baozhu; Yu, Minghui

    2018-03-01

    A modified hydrometeor classification algorithm (HCA) is developed in this study for Chinese polarimetric radars. This algorithm is based on the U.S. operational HCA. Meanwhile, the methodology of statistics-based optimization is proposed including calibration checking, datasets selection, membership functions modification, computation thresholds modification, and effect verification. Zhuhai radar, the first operational polarimetric radar in South China, applies these procedures. The systematic bias of calibration is corrected, the reliability of radar measurements deteriorates when the signal-to-noise ratio is low, and correlation coefficient within the melting layer is usually lower than that of the U.S. WSR-88D radar. Through modification based on statistical analysis of polarimetric variables, the localized HCA especially for Zhuhai is obtained, and it performs well over a one-month test through comparison with sounding and surface observations. The algorithm is then utilized for analysis of a squall line process on 11 May 2014 and is found to provide reasonable details with respect to horizontal and vertical structures, and the HCA results—especially in the mixed rain-hail region—can reflect the life cycle of the squall line. In addition, the kinematic and microphysical processes of cloud evolution and the differences between radar-detected hail and surface observations are also analyzed. The results of this study provide evidence for the improvement of this HCA developed specifically for China.

  6. Polarimetric receiver in the forty gigahertz band: new instrument for the Q-U-I joint Tenerife experiment

    Science.gov (United States)

    Villa, Enrique; Cano, Juan L.; Aja, Beatriz; Terán, J. Vicente; de la Fuente, Luisa; Mediavilla, Ángel; Artal, Eduardo

    2018-03-01

    This paper describes the analysis, design and characterization of a polarimetric receiver developed for covering the 35 to 47 GHz frequency band in the new instrument aimed at completing the ground-based Q-U-I Joint Tenerife Experiment. This experiment is designed to measure polarization in the Cosmic Microwave Background. The described high frequency instrument is a HEMT-based array composed of 29 pixels. A thorough analysis of the behaviour of the proposed receiver, based on electronic phase switching, is presented for a noise-like linearly polarized input signal, obtaining simultaneously I, Q and U Stokes parameters of the input signal. Wideband subsystems are designed, assembled and characterized for the polarimeter. Their performances are described showing appropriate results within the 35-to-47 GHz frequency band. Functionality tests are performed at room and cryogenic temperatures with adequate results for both temperature conditions, which validate the receiver concept and performance.

  7. Automated detection and characterization of harmonic tremor in continuous seismic data

    Science.gov (United States)

    Roman, Diana C.

    2017-06-01

    Harmonic tremor is a common feature of volcanic, hydrothermal, and ice sheet seismicity and is thus an important proxy for monitoring changes in these systems. However, no automated methods for detecting harmonic tremor currently exist. Because harmonic tremor shares characteristics with speech and music, digital signal processing techniques for analyzing these signals can be adapted. I develop a novel pitch-detection-based algorithm to automatically identify occurrences of harmonic tremor and characterize their frequency content. The algorithm is applied to seismic data from Popocatepetl Volcano, Mexico, and benchmarked against a monthlong manually detected catalog of harmonic tremor events. During a period of heightened eruptive activity from December 2014 to May 2015, the algorithm detects 1465 min of harmonic tremor, which generally precede periods of heightened explosive activity. These results demonstrate the algorithm's ability to accurately characterize harmonic tremor while highlighting the need for additional work to understand its causes and implications at restless volcanoes.

  8. High-resolution optical polarimetric elastography for measuring the mechanical properties of tissue

    Science.gov (United States)

    Hudnut, Alexa W.; Armani, Andrea M.

    2018-02-01

    Traditionally, chemical and molecular markers have been the predominate method in diagnostics. Recently, alternate methods of determining tissue and disease characteristics have been proposed based on testing the mechanical behavior of biomaterials. Existing methods for performing elastography measurements, such as atomic force microscopy, compression testing, and ultrasound elastography, require either extensive sample processing or have poor resolution. In the present work, we demonstrate an optical polarimetric elastography device to characterize the mechanical properties of salmon skeletal muscle. A fiber-coupled 1550nm laser paired with an optical polarizer is used to create a fiber optic sensing region. By measuring the change in polarization from the initial state to the final state within the fiber sensing region with a polarimeter, the loading-unloading curves can be determined for the biomaterial. The device is used to characterize the difference between samples with a range of collagen membranes. The loading-unloading curves are used to determine the change in polarization phase and energy loss of the samples at 10%, 20% and 30% strain. As expected, the energy loss is a better metric for measuring the mechanical properties of the tissues because it incorporates the entire loading-unloading curve rather than a single point. Using this metric, it is demonstrated the device can repeatedly differentiate between the different membrane configurations.

  9. Microbiology and Biodegradation: Deep Ultraviolet Microscopy for the Detection, Quantification, and Characterization of Microbes

    Science.gov (United States)

    2015-11-16

    Approved for Public Release; Distribution Unlimited Final Report: 14.3 Microbiology and Biodegradation: Deep Ultraviolet Microscopy for the Detection...Fluroesence; Raman Spectroscopy; Microbiology REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 10. SPONSOR/MONITOR’S ACRONYM(S) ARO...14.3 Microbiology and Biodegradation: Deep Ultraviolet Microscopy for the Detection, Quantification, and Characterization of Microbes Report Title

  10. An Icon-Based Synoptic Visualization of Fully Polarimetric Radar Data

    Directory of Open Access Journals (Sweden)

    Iain H. Woodhouse

    2012-03-01

    Full Text Available The visualization of fully polarimetric radar data is hindered by traditional remote sensing methodologies for displaying data due to the large number of parameters per pixel in such data, and the non-scalar nature of variables such as phase difference. In this paper, a new method is described that uses icons instead of image pixels to represent the image data so that polarimetric properties and geographic context can be visualized together. The icons are parameterized using the alpha-entropy decomposition of polarimetric data. The resulting image allows the following five variables to be displayed simultaneously: unpolarized power, alpha angle, polarimetric entropy, anisotropy and orientation angle. Examples are given for both airborne and laboratory-based imaging.

  11. GPM GROUND VALIDATION NASA S-BAND DUAL POLARIMETRIC (NPOL) DOPPLER RADAR IFLOODS V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GPM Ground Validation NASA S-Band Dual Polarimetric (NPOL) Doppler Radar IFloodS data set was collected from April 30, 2013 to June 16, 2013 near Traer, Iowa as...

  12. The Development of Polarimetric and Nonpolarimetric Multiwavelength Focal Plane Arrays, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — High-performance polarimetric and nonpolarimetric sensing is crucial to upcoming NASA missions, including ACE and CLARREO and the multi-agency VIIRS NPP project. The...

  13. CAMEX-4 MOBILE X-BAND POLARIMETRIC WEATHER RADAR V1

    Data.gov (United States)

    National Aeronautics and Space Administration — Mobile X-band Polarimetric Weather Radar on Wheels (X-POW)is a Doppler scanning radar operating at 9.3 GHz.with horizontal and vertical polarization. Used for...

  14. Adaptive polarimetric image representation for contrast optimization of a polarized beacon through fog

    International Nuclear Information System (INIS)

    Panigrahi, Swapnesh; Fade, Julien; Alouini, Mehdi

    2015-01-01

    We present a contrast-maximizing optimal linear representation of polarimetric images obtained from a snapshot polarimetric camera for enhanced vision of a polarized light source in obscured weather conditions (fog, haze, cloud) over long distances (above 1 km). We quantitatively compare the gain in contrast obtained by different linear representations of the experimental polarimetric images taken during rapidly varying foggy conditions. It is shown that the adaptive image representation that depends on the correlation in background noise fluctuations in the two polarimetric images provides an optimal contrast enhancement over all weather conditions as opposed to a simple difference image which underperforms during low visibility conditions. Finally, we derive the analytic expression of the gain in contrast obtained with this optimal representation and show that the experimental results are in agreement with the assumed correlated Gaussian noise model. (paper)

  15. Tropical Mangrove Mapping Using Fully-Polarimetric Radar Data

    Directory of Open Access Journals (Sweden)

    Bambang Trisasongko

    2009-09-01

    Full Text Available Although mangrove is one of important ecosystems in the world, it has been abused and exploited by human for various purposes. Monitoring mangrove is therefore required to maintain a balance between economy and conservation and provides up-to-date information for rehabilitation. Optical remote sensing data have delivered such information, however ever-changing atmospheric disturbance may significantly decrease thematic content. In this research, Synthetic Aperture Radar (SAR fully polarimetric data were evaluated to present an alternative for mangrove mapping. Assessment using three statistical trees was performed on both tonal and textural data. It was noticeable that textural data delivered fairly good improvement which reduced the error rate to around 5-6% at L-band. This suggests that insertion of textural data is more important than any information derived from decomposition algorithm.

  16. Analytical Aspects of Total Starch Polarimetric Determination in Some Cereals

    Directory of Open Access Journals (Sweden)

    Rodica Caprita

    2016-10-01

    Full Text Available Starch is the most important digestible polysaccharide present in foods and feeds. The starch concentration in cereals cannot be determined directly, because the starch is contained within a structurally and chemically complex matrix. Fine grinding and boiling in dilute HCl are preparative steps necessary for complete release of the starch granules from the protein matrix. Starch can be determined using simple and inexpensive physical methods, such as density, refractive index or optical rotation assessment. The polarimetric method allows the determination even of small starch contents due to its extremely high specific rotation. For more accurate results, the contribution of free sugars is eliminated by dissolution in 40% (V/V ethanol. The influence of other optically active substances, which might interfere, is removed by filtration/clarification prior to the optical rotation measurement.

  17. Vegetation Parameter Extraction Using Dual Baseline Polarimetric SAR Interferometry Data

    Science.gov (United States)

    Zhang, H.; Wang, C.; Chen, X.; Tang, Y.

    2009-04-01

    For vegetation parameter inversion, the single baseline polarimetric SAR interferometry (POLinSAR) technique, such as the three-stage method and the ESPRIT algorithm, is limited by the observed data with the minimum ground to volume amplitude ration, which effects the estimation of the effective phase center for the vegetation canopy or the surface, and thus results in the underestimated vegetation height. In order to remove this effect of the single baseline inversion techniques in some extend, another baseline POLinSAR data is added on vegetation parameter estimation in this paper, and a dual baseline POLinSAR technique for the extraction of the vegetation parameter is investigated and improved to reduce the dynamic bias for the vegetation parameter estimation. Finally, the simulated data and real data are used to validate this dual baseline technique.

  18. Classification of Polarimetric SAR Data Using Dictionary Learning

    DEFF Research Database (Denmark)

    Vestergaard, Jacob Schack; Nielsen, Allan Aasbjerg; Dahl, Anders Lindbjerg

    2012-01-01

    This contribution deals with classification of multilook fully polarimetric synthetic aperture radar (SAR) data by learning a dictionary of crop types present in the Foulum test site. The Foulum test site contains a large number of agricultural fields, as well as lakes, forests, natural vegetation......, grasslands and urban areas, which make it ideally suited for evaluation of classification algorithms. Dictionary learning centers around building a collection of image patches typical for the classification problem at hand. This requires initial manual labeling of the classes present in the data and is thus...... a method for supervised classification. Sparse coding of these image patches aims to maintain a proficient number of typical patches and associated labels. Data is consecutively classified by a nearest neighbor search of the dictionary elements and labeled with probabilities of each class. Each dictionary...

  19. Polarimetric SAR image classification based on discriminative dictionary learning model

    Science.gov (United States)

    Sang, Cheng Wei; Sun, Hong

    2018-03-01

    Polarimetric SAR (PolSAR) image classification is one of the important applications of PolSAR remote sensing. It is a difficult high-dimension nonlinear mapping problem, the sparse representations based on learning overcomplete dictionary have shown great potential to solve such problem. The overcomplete dictionary plays an important role in PolSAR image classification, however for PolSAR image complex scenes, features shared by different classes will weaken the discrimination of learned dictionary, so as to degrade classification performance. In this paper, we propose a novel overcomplete dictionary learning model to enhance the discrimination of dictionary. The learned overcomplete dictionary by the proposed model is more discriminative and very suitable for PolSAR classification.

  20. Discrimination of Oil Slicks and Lookalikes in Polarimetric SAR Images Using CNN

    OpenAIRE

    Guo, Hao; Wu, Danni; An, Jubai

    2017-01-01

    Oil slicks and lookalikes (e.g., plant oil and oil emulsion) all appear as dark areas in polarimetric Synthetic Aperture Radar (SAR) images and are highly heterogeneous, so it is very difficult to use a single feature that can allow classification of dark objects in polarimetric SAR images as oil slicks or lookalikes. We established multi-feature fusion to support the discrimination of oil slicks and lookalikes. In the paper, simple discrimination analysis is used to rationalize a preferred f...

  1. An icon-based synoptic visualization of fully polarimetric radar data

    OpenAIRE

    Woodhouse, I.H.; Turner, Dean

    2012-01-01

    The visualization of fully polarimetric radar data is hindered by traditional remote sensing methodologies for displaying data due to the large number of parameters per pixel in such data, and the non-scalar nature of variables such as phase difference. In this paper, a new method is described that uses icons instead of image pixels to represent the image data so that polarimetric properties and geographic context can be visualized together. The icons are parameterized using the alpha-entropy...

  2. Polarimetric Radar Retrievals in Southeast Texas During Hurricane Harvey

    Science.gov (United States)

    Wolff, D. B.; Petersen, W. A.; Tokay, A.; Marks, D. A.; Pippitt, J. L.; Kirstetter, P. E.

    2017-12-01

    Hurricane Harvey hit the Texas Gulf Coast as a major hurricane on August 25, 2017 before exiting the state as a tropical storm on September 1, 2017. In its wake, it left a flood of historic proportions, with some areas measuring 60 inches of rain over a five-day period. Although the storm center stayed west of the immediate Houston area training bands of precipitation impacted the Houston area for five full days. The National Weather Service (NWS) WSR88D dual-polarimetric radar (KHGX), located southeast of Houston, maintained operations for the entirety of the event. The Harris County Flood Warning System (HCFWS) had 150 rain gauges deployed in its network and seven NWS Automated Surface Observing Systems (ASOS) rain gauges are also located in the area. In this study, we used the full radar data set to retrieve daily and event-total precipitation estimates within 120 km of the KHGX radar for the period August 25-29, 2017. These estimates were then compared to the HCFWS and ASOS gauges. Three different polarimetric hybrid rainfall retrievals were used: Ciffeli et al. 2011; Bringi et al. 2004; and, Chen et al. 2017. Each of these hybrid retrievals have demonstrated robust performance in the past. However, both daily and event-total comparisons from each of these retrievals compared to those of HCFWS and ASOS rain gauge networks resulted in significant underestimates by the radar retrievals. These radar underestimates are concerning. Sources of error and variance will be investigated to understand the source of radar-gauge disagreement. One current hypothesis is that due to the large number of small drops often found in hurricanes, the differential reflectivity and specific differential phase are relatively small so that the hybrid algorithms use only the reflectivity/rain rate procedure (so called Z-R relationships), and hence rarely invoke the ZDR or KDP procedures. Thus, an alternative Z-R relationship must be invoked to retrieve accurate rain rate estimates.

  3. HIGH-RESOLUTION LINEAR POLARIMETRIC IMAGING FOR THE EVENT HORIZON TELESCOPE

    Energy Technology Data Exchange (ETDEWEB)

    Chael, Andrew A.; Johnson, Michael D.; Narayan, Ramesh; Doeleman, Sheperd S. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Wardle, John F. C. [Brandeis University, Physics Department, Waltham, MA 02454 (United States); Bouman, Katherine L., E-mail: achael@cfa.harvard.edu [Massachusetts Institute of Technology, Computer Science and Artificial Intelligence Laboratory, 32 Vassar Street, Cambridge, MA 02139 (United States)

    2016-09-20

    Images of the linear polarizations of synchrotron radiation around active galactic nuclei (AGNs) highlight their projected magnetic field lines and provide key data for understanding the physics of accretion and outflow from supermassive black holes. The highest-resolution polarimetric images of AGNs are produced with Very Long Baseline Interferometry (VLBI). Because VLBI incompletely samples the Fourier transform of the source image, any image reconstruction that fills in unmeasured spatial frequencies will not be unique and reconstruction algorithms are required. In this paper, we explore some extensions of the Maximum Entropy Method (MEM) to linear polarimetric VLBI imaging. In contrast to previous work, our polarimetric MEM algorithm combines a Stokes I imager that only uses bispectrum measurements that are immune to atmospheric phase corruption, with a joint Stokes Q and U imager that operates on robust polarimetric ratios. We demonstrate the effectiveness of our technique on 7 and 3 mm wavelength quasar observations from the VLBA and simulated 1.3 mm Event Horizon Telescope observations of Sgr A* and M87. Consistent with past studies, we find that polarimetric MEM can produce superior resolution compared to the standard CLEAN algorithm, when imaging smooth and compact source distributions. As an imaging framework, MEM is highly adaptable, allowing a range of constraints on polarization structure. Polarimetric MEM is thus an attractive choice for image reconstruction with the EHT.

  4. Characterization of new FBK SiPM technology for visible light detection

    International Nuclear Information System (INIS)

    Serra, N; Ferri, A; Gola, A; Pro, T; Tarolli, A; Zorzi, N; Piemonte, C

    2013-01-01

    This paper presents the characterization of the new n-on-p SiPM technology developed at Fondazione Bruno Kessler (FBK, Trento-Italy). Several device aspects such as dark count rate, photo detection efficiency, breakdown voltage uniformity, and temperature stability have been significantly improved with respect to the original FBK SiPM technology. The modifications introduced involve the internal device structure and are based on an electric-field engineering approach. We report on the dark characterization, the visible light detection efficiency and 511 keV gamma ray energy resolution, when reading out small LYSO or Ce:GAGG crystals, of the new devices. In parallel, a comparison to the original SiPMs is done in order to underline the main advancements that have been obtained. We refer this new technology to as RGB-SiPMs because of the high detection efficiency for the whole red, green, and blue part of the spectrum.

  5. Molecular Detection and Characterization of Goat Isolate of Taenia hydatigena in Turkey

    Directory of Open Access Journals (Sweden)

    Armagan Erdem Utuk

    2012-01-01

    Full Text Available The aim of this study was to provide molecular detection and characterization of the goat isolate of Taenia hydatigena from Ankara province of Turkey. For this purpose, PCR amplification of small subunit ribosomal RNA (rrnS and partial sequencing of mitochondrial cytochrome c oxidase subunit 1 (mt-CO1 genes were performed in a one-month-old dead goat. According to rrnS-PCR results, parasites were identified as Taenia spp., and partial sequence of mt-CO1 gene was corresponding to T. hydatigena. At the end of the study, we concluded that molecular tools can be used to define species of parasites in cases where the key morphologic features cannot be detected. Nucleotide sequence data of Turkish goat isolate of T. hydatigena was submitted to GenBank for other researchers interested in this subject. By this study, molecular detection and characterization of T. hydatigena was done for the first time in Turkey.

  6. A Model-Free Diagnosis Approach for Intake Leakage Detection and Characterization in Diesel Engines

    Directory of Open Access Journals (Sweden)

    Ghaleb Hoblos

    2015-07-01

    Full Text Available Feature selection is an essential step for data classification used in fault detection and diagnosis processes. In this work, a new approach is proposed, which combines a feature selection algorithm and a neural network tool for leak detection and characterization tasks in diesel engine air paths. The Chi square classifier is used as the feature selection algorithm and the neural network based on Levenberg-Marquardt is used in system behavior modeling. The obtained neural network is used for leak detection and characterization. The model is learned and validated using data generated by xMOD. This tool is used again for testing. The effectiveness of the proposed approach is illustrated in simulation when the system operates on a low speed/load and the considered leak affecting the air path is very small.

  7. Characterizing Dynamic Walking Patterns and Detecting Falls with Wearable Sensors Using Gaussian Process Methods

    Directory of Open Access Journals (Sweden)

    Taehwan Kim

    2017-05-01

    Full Text Available By incorporating a growing number of sensors and adopting machine learning technologies, wearable devices have recently become a prominent health care application domain. Among the related research topics in this field, one of the most important issues is detecting falls while walking. Since such falls may lead to serious injuries, automatically and promptly detecting them during daily use of smartphones and/or smart watches is a particular need. In this paper, we investigate the use of Gaussian process (GP methods for characterizing dynamic walking patterns and detecting falls while walking with built-in wearable sensors in smartphones and/or smartwatches. For the task of characterizing dynamic walking patterns in a low-dimensional latent feature space, we propose a novel approach called auto-encoded Gaussian process dynamical model, in which we combine a GP-based state space modeling method with a nonlinear dimensionality reduction method in a unique manner. The Gaussian process methods are fit for this task because one of the most import strengths of the Gaussian process methods is its capability of handling uncertainty in the model parameters. Also for detecting falls while walking, we propose to recycle the latent samples generated in training the auto-encoded Gaussian process dynamical model for GP-based novelty detection, which can lead to an efficient and seamless solution to the detection task. Experimental results show that the combined use of these GP-based methods can yield promising results for characterizing dynamic walking patterns and detecting falls while walking with the wearable sensors.

  8. Preliminary Evaluation of GAOFEN-3 Polarimetric and Radiometric Accuracy by Corner Reflectors in Inner Mongolia

    Science.gov (United States)

    Shi, L.; Ding, X.; Li, P.; Yang, J.; Zhao, L.; Yang, L.; Chang, Y.; Yan, L.

    2018-04-01

    On August 10, 2016, China launched its first C-band full polarimetric radar satellite, named Gaofen-3 (GF-3), for urban and agriculture monitoring, landslide detection, ocean applications, etc. According to the design specification, GF-3 is expected to work at -35 dB crosstalk and 0.5 dB channel imbalance, with less than 10 degree error. The absolute radiometric bias is expected to be less than 1.5 dB in a single scene and 2.0 dB when operating for a long time. To complete the calibration and evaluation, the Institute of Electronics, Chinese Academy Sciences (IECAS) built a test site at Inner Mongolia, and deployed active reflectors (ARs) and trihedral corner reflectors (CRs) to solve and evaluate the hardware distortion. To the best of the authors' knowledge, the product accuracy of GF-3 has not been comprehensively evaluated in any open publication. The remote sensing community urgently requires a detailed report about the product accuracy and stability, before any subsequent application. From June to August of 2017, IECAS begun its second round ground campaign and deployed 10 CRs to evaluate product distortions. In this paper, we exploit Inner Mongolia CRs to investigate polarimetric and radiometric accuracy of QPSI I Stripmap. Although some CRs found fall into AR side lobe, the rest CRs enable us to preliminarily evaluate the accuracy of some special imaging beams. In the experimental part, the image of July 6, 2017 was checked by 5 trihedral CRs and the integration estimation method demonstrated the crosstalk varying from -42.65 to -32.74 dB, and the channel imbalance varying from -0.21 to 0.47 with phase error from -2.4 to 0.2 degree. Comparing with the theoretical radar cross-section of 1.235 m trihedral CR, i.e. 35 dB, the radiometric error varies about 0.20 ± 0.29 dB in HH channel and 0.40 ± 0.20 dB in VV channel.

  9. Meterwavelength Single-pulse Polarimetric Emission Survey. III. The Phenomenon of Nulling in Pulsars

    Energy Technology Data Exchange (ETDEWEB)

    Basu, Rahul; Mitra, Dipanjan; Melikidze, George I., E-mail: rahulbasu.astro@gmail.com [Janusz Gil Institute of Astronomy, University of Zielona Góra, ul. Szafrana 2, 65–516 Zielona Góra (Poland)

    2017-09-10

    A detailed analysis of nulling was conducted for the pulsars studied in the Meterwavelength Single-pulse Polarimetric Emission Survey. We characterized nulling in 36 pulsars including 17 pulsars where the phenomenon was reported for the first time. The most dominant nulls lasted for a short duration, less than five periods. Longer duration nulls extending to hundreds of periods were also seen in some cases. A careful analysis showed the presence of periodicities in the transition from the null to the burst states in 11 pulsars. In our earlier work, fluctuation spectrum analysis showed multiple periodicities in 6 of these 11 pulsars. We demonstrate that the longer periodicity in each case was associated with nulling. The shorter periodicities usually originate from subpulse drifting. The nulling periodicities were more aligned with the periodic amplitude modulation, indicating a possible common origin for both. The most prevalent nulls last for a single period and can be potentially explained using random variations affecting the plasma processes in the pulsar magnetosphere. On the other hand, longer-duration nulls require changes in the pair-production processes, which need an external triggering mechanism for the changes. The presence of periodic nulling puts an added constraint on the triggering mechanism, which also needs to be periodic.

  10. Technologies and methods used for the detection, enrichment and characterization of cancer stem cells.

    Science.gov (United States)

    Williams, Anthony; Datar, Ram; Cote, Richard

    2010-01-01

    Cancer stem cells (CSCs) represent a subclass of tumour cells with the ability for self-renewal, production of differentiated progeny, prolonged survival, resistance to damaging therapeutic agents, and anchorage-independent survival, which together make this population effectively equipped to metastasize, invade and colonize secondary tissues in the face of therapeutic intervention. In recent years, investigators have increasingly focused on the characterization of CSCs to better understand the mechanisms that govern malignant disease progression in an effort to develop more effective, targeted therapeutic agents. The primary obstacle to the study of CSCs, however, is their rarity. Thus, the study of CSCs requires the use of sensitive and efficient technologies for their enrichment and detection. This review discusses technologies and methods that have been adapted and used to isolate and characterize CSCs to date, as well as new potential directions for the enhanced enrichment and detection of CSCs. While the technologies used for CSC enrichment and detection have been useful thus far for their characterization, each approach is not without limitations. Future studies of CSCs will depend on the enhanced sensitivity and specificity of currently available technologies, and the development of novel technologies for increased detection and enrichment of CSCs.

  11. Carboxymethylguargum-silver nanocomposite: green synthesis, characterization and an optical sensor for ammonia detection

    International Nuclear Information System (INIS)

    Gupta, Anek Pal; Verma, Devendra Kumar

    2014-01-01

    This work describes the preparation of new carboxymethyl guar gum-silver nanocomposite (CMGG/Ag NC) by green synthesis method. For this carboxymethyl guar gum was used as a reducing agent as well as stabilizer. The silver nanoparticles obtained were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), UV–vis spectroscopy, Fourier transform infrared (FTIR) and energy dispersive x-ray analysis (EDX). The average size of the silver nanoparticles was found of ∼6 nm. Thus, the obtained CMGG/AgNPs NC was examined for optical sensing property for detection of ammonia in aqueous medium. The response time and the detection limit of ammonia in aqueous solution were detected at room temperature. It was concluded that in the future, at this room temperature optical ammonia sensor may be used for medical diagnosis and clinically for detecting low ammonia level (up to 1 ppm) in biological samples for various biomedical applications. (paper)

  12. Optical diagnostic of breast cancer using Raman, polarimetric and fluorescence spectroscopy

    Science.gov (United States)

    Anwar, Shahzad; Firdous, Shamaraz; Rehman, Aziz-ul; Nawaz, Muhammed

    2015-04-01

    We presented the optical diagnostic of normal and cancerous human breast tissues using Raman, polarimetric and fluorescence spectroscopic techniques. Breast cancer is the second leading cause of cancer death among women worldwide. Optical diagnostics of cancer offered early intervention and the greatest chance of cure. Spectroscopic data were collected from freshly excised surgical specimens of normal tissues with Raman bands at 800, 1171 and 1530 cm-1 arising mainly by lipids, nucleic acids, proteins, carbohydrates and amino acids. For breast cancer, Raman bands are observed at 1070, 1211, 1495, 1583 and 1650 cm-1. Results demonstrate that the spectra of normal tissue are dominated by lipids and amino acids. Polarization decomposition of the Mueller matrix and confocal microscopic fluorescence provides detailed description of cancerous tissue and distinguishes between the normal and malignant one. Based on these findings, we successfully differentiate normal and malignant breast tissues at an early stage of disease. There is a need to develop a new tool for noninvasive, real-time diagnosis of tissue abnormalities and a test procedure for detecting breast cancer at an early stage.

  13. Polarimetric observations of the innermost regions of relativistic jets in X-ray binaries

    Directory of Open Access Journals (Sweden)

    Russell D.M.

    2013-12-01

    Full Text Available Synchrotron emission from the relativistic jets launched close to black holes and neutron stars can be highly linearly polarized, depending on the configuration of the magnetic field. In X-ray binaries, optically thin synchrotron emission from the compact jets resides at infrared–optical wavelengths. The polarimetric signature of the jets is detected in the infrared and is highly variable in some X-ray binaries. This reveals the magnetic geometry in the compact jet, in a region close enough to the black hole that it is influenced by its strong gravity. In some cases the magnetic field is turbulent and variable near the jet base. In Cyg X–1, the origin of the γ-ray, X-ray and some of the infrared polarization is likely the optically thin synchrotron power law from the inner regions of the jet. In order to reproduce the polarization properties, the magnetic field in this region must be highly ordered, in contrast to other sources.

  14. USGS Tweet Earthquake Dispatch (@USGSted): Using Twitter for Earthquake Detection and Characterization

    Science.gov (United States)

    Liu, S. B.; Bouchard, B.; Bowden, D. C.; Guy, M.; Earle, P.

    2012-12-01

    desktop computer at the time of the detections. The continuously updating map displays geolocated tweets arriving after the detection and plots epicenters of recent earthquakes. When available, seismograms from nearby stations are displayed as an additional form of verification. A time series of tweets-per-minute is also shown to illustrate the volume of tweets being generated for the detected event. Future additions are being investigated to provide a more in-depth characterization of the seismic events based on an analysis of tweet text and content from other social media sources.

  15. Generation, detection and characterization of gas-phase transition metal aggregates and compounds

    International Nuclear Information System (INIS)

    Steimle, T.C.

    1992-01-01

    The goal of our research is to employ spectroscopic techniques to characterize the bound portions of the potential energy surface (PES) for chemical systems involving diatomic and triatomic transition metal molecules. The approach incorporates the generation and isolation of new metal compounds via supersonic laser ablation molecular beam techniques. Detection and characterization is achieved using high resolution dye laser induced fluorescence spectroscopy. A major objective is to produce information which can be compared to theoretical predictions and thereby provide guidelines and insight into the development of reaction models

  16. Detection and genetic characterization of a novel parvovirus distantly related to human bufavirus in domestic pigs.

    Science.gov (United States)

    Hargitai, Renáta; Pankovics, Péter; Kertész, Attila Mihály; Bíró, Hunor; Boros, Ákos; Phan, Tung Gia; Delwart, Eric; Reuter, Gábor

    2016-04-01

    In this study, a novel parvovirus (strain swine/Zsana3/2013/HUN, KT965075) was detected in domestic pigs and genetically characterized by viral metagenomics and PCR methods. The novel parvovirus was distantly related to the human bufaviruses and was detected in 19 (90.5 %) of the 21 and five (33.3 %) of the 15 faecal samples collected from animals with and without cases of posterior paraplegia of unknown etiology from five affected farms and one control farm in Hungary, respectively. Swine/Zsana3/2013/HUN is highly prevalent in domestic pigs and potentially represents a novel parvovirus species in the subfamily Parvovirinae.

  17. Shallow Reflection Method for Water-Filled Void Detection and Characterization

    Science.gov (United States)

    Zahari, M. N. H.; Madun, A.; Dahlan, S. H.; Joret, A.; Hazreek, Z. A. M.; Mohammad, A. H.; Izzaty, R. A.

    2018-04-01

    Shallow investigation is crucial in enhancing the characteristics of subsurface void commonly encountered in civil engineering, and one such technique commonly used is seismic-reflection technique. An assessment of the effectiveness of such an approach is critical to determine whether the quality of the works meets the prescribed requirements. Conventional quality testing suffers limitations including: limited coverage (both area and depth) and problems with resolution quality. Traditionally quality assurance measurements use laboratory and in-situ invasive and destructive tests. However geophysical approaches, which are typically non-invasive and non-destructive, offer a method by which improvement of detection can be measured in a cost-effective way. Of this seismic reflection have proved useful to assess void characteristic, this paper evaluates the application of shallow seismic-reflection method in characterizing the water-filled void properties at 0.34 m depth, specifically for detection and characterization of void measurement using 2-dimensional tomography.

  18. Changes of polarimetric scattering characteristics of ALOS PALSAR caused by the 2011 Eruption of Shinmoe-dake Volcano

    Science.gov (United States)

    Ohkura, Hiroshi

    Full polarimetric SAR images of ALOS PALSAR of Shinmoe-dake volcano in Japan were analyzed. The volcano erupted in January, 2011 and volcano ash deposited more than 10 cm in 12 km (2) and 1 m in 2 km (2) . Two images before and after the eruption were compared based on a point view of the four-component scattering model to detect changes of polarimetric scattering characteristics. The main detected changes are as follows. Total power of the four-component scattering model decreased on a farslope after the eruption. An incident angle on a farslope is larger than the angle on a foreslope. Decrease of surface roughness due to deposited volcanic ashes makes back-scattering smaller in the area of a larger incidence angle. However the rate of the double-bounce component got higher in a forest at the foot of a mountain slope and on a plain, where the ground surface is almost horizontal and the incident angle is relatively-large. Decrease of roughness of the forest floor increases forward scattering on the floor of the larger incident angle. This increases the double-bounced scattering due to bouncing back between the forest floor and trunks which stand "perpendicularly" on the almost horizontal forest floor. The rate of the surface scattering component got higher around an area where layover occurred. In the study area, most of layovers occurred at a ridge where an incidence angle was small. Decrease of surface roughness due to the ash deposit increases the surface scattering power in the area of the small incidence angle.

  19. Polarimetric analysis of a CdZnTe spectro-imager under multi-pixel irradiation conditions

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, M. [LIP-Laboratório de Instrumentação e Física Experimental de Partículas (Portugal); Physics Department, University of Coimbra, Coimbra (Portugal); Curado da Silva, R.M., E-mail: rui.silva@coimbra.lip.pt [LIP-Laboratório de Instrumentação e Física Experimental de Partículas (Portugal); Physics Department, University of Coimbra, Coimbra (Portugal); Maia, J.M. [LIP-Laboratório de Instrumentação e Física Experimental de Partículas (Portugal); Physics Department, University of Beira-Interior, Covilhã (Portugal); Simões, N. [LIP-Laboratório de Instrumentação e Física Experimental de Partículas (Portugal); Physics Department, University of Coimbra, Coimbra (Portugal); Marques, J. [LIP-Laboratório de Instrumentação e Física Experimental de Partículas (Portugal); Centro de Astrofísica, Universidade do Porto, Porto (Portugal); Pereira, L.; Trindade, A.M.F. [LIP-Laboratório de Instrumentação e Física Experimental de Partículas (Portugal); and others

    2016-12-21

    So far, polarimetry in high-energy astrophysics has been insufficiently explored due to the complexity of the required detection, electronic and signal processing systems. However, its importance is today largely recognized by the astrophysical community, therefore the next generation of high-energy space instruments will certainly provide polarimetric observations, contemporaneously with spectroscopy and imaging. We have been participating in high-energy observatory proposals submitted to ESA Cosmic Vision calls, such as GRI (Gamma-Ray Imager), DUAL and ASTROGAM, where the main instrument was a spectro-imager with polarimetric capabilities. More recently, the H2020 AHEAD project was launched with the objective to promote more coherent and mature future high-energy space mission proposals. In this context of high-energy proposal development, we have tested a CdZnTe detection plane prototype polarimeter under a partially polarized gamma-ray beam generated from an aluminum target irradiated by a {sup 22}Na (511 keV) radioactive source. The polarized beam cross section was 1 cm{sup 2}, allowing the irradiation of a wide multi-pixelated area where all the pixels operate simultaneously as a scatterer and as an absorber. The methods implemented to analyze such multi-pixel irradiation are similar to those required to analyze a spectro-imager polarimeter operating in space, since celestial source photons should irradiate its full pixilated area. Correction methods to mitigate systematic errors inherent to CdZnTe and to the experimental conditions were also implemented. The polarization level (~40%) and the polarization angle (precision of ±5° up to ±9°) obtained under multi-pixel irradiation conditions are presented and compared with simulated data.

  20. Molecular biophysics: detection and characterization of damage in molecular, cellular, and physiological systems

    International Nuclear Information System (INIS)

    Danyluk, S.S.

    1979-01-01

    This section contains summaries of research on the detection and characterization of damage in molecular, cellular, and physiological systems. Projects under investigation in this section include: chemical synthesis of nucleic acid derivatives; structural and conformational properties of biological molecules in solution; crystallographic and chemical studies of immunoglobulin structure; instrument design and development for x-ray and neutron scattering studies of biological molecules; and chromobiology and circadian regulation

  1. Detection, Characterization and Typing of Shiga toxin-producing Escherichia coli.

    OpenAIRE

    Brendon David Parsons; Nathan eZelyas; Byron M Berenger; Linda eChui; Linda eChui

    2016-01-01

    Shiga toxin-producing Escherichia coli (STEC) are responsible for gastrointestinal diseases reported in numerous outbreaks around the world. Given the public health importance of STEC, effective detection, characterization and typing is critical to any medical laboratory system. While non-O157 serotypes account for the majority of STEC infections, frontline microbiology laboratories may only screen for STEC using O157-specific agar-based methods. As a result, non-O157 STEC infections are sign...

  2. Detection, Characterization, and Typing of Shiga Toxin-Producing Escherichia coli.

    Science.gov (United States)

    Parsons, Brendon D; Zelyas, Nathan; Berenger, Byron M; Chui, Linda

    2016-01-01

    Shiga toxin-producing Escherichia coli (STEC) are responsible for gastrointestinal diseases reported in numerous outbreaks around the world. Given the public health importance of STEC, effective detection, characterization and typing is critical to any medical laboratory system. While non-O157 serotypes account for the majority of STEC infections, frontline microbiology laboratories may only screen for STEC using O157-specific agar-based methods. As a result, non-O157 STEC infections are significantly under-reported. This review discusses recent advances on the detection, characterization and typing of STEC with emphasis on work performed at the Alberta Provincial Laboratory for Public Health (ProvLab). Candidates for the detection of all STEC serotypes include chromogenic agars, enzyme immunoassays (EIA) and quantitative real time polymerase chain reaction (qPCR). Culture methods allow further characterization of isolates, whereas qPCR provides the greatest sensitivity and specificity, followed by EIA. The virulence gene profiles using PCR arrays and stx gene subtypes can subsequently be determined. Different non-O157 serotypes exhibit markedly different virulence gene profiles and a greater prevalence of stx1 than stx2 subtypes compared to O157:H7 isolates. Finally, recent innovations in whole genome sequencing (WGS) have allowed it to emerge as a candidate for the characterization and typing of STEC in diagnostic surveillance isolates. Methods of whole genome analysis such as single nucleotide polymorphisms and k-mer analysis are concordant with epidemiological data and standard typing methods, such as pulsed-field gel electrophoresis and multiple-locus variable number tandem repeat analysis while offering additional strain differentiation. Together these findings highlight improved strategies for STEC detection using currently available systems and the development of novel approaches for future surveillance.

  3. Detection, Characterization and Typing of Shiga toxin-producing Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Brendon David Parsons

    2016-04-01

    Full Text Available Shiga toxin-producing Escherichia coli (STEC are responsible for gastrointestinal diseases reported in numerous outbreaks around the world. Given the public health importance of STEC, effective detection, characterization and typing is critical to any medical laboratory system. While non-O157 serotypes account for the majority of STEC infections, frontline microbiology laboratories may only screen for STEC using O157-specific agar-based methods. As a result, non-O157 STEC infections are significantly under-reported. This review discusses recent advances on the detection, characterization and typing of STEC with emphasis on work performed at the Alberta Provincial Laboratory for Public Health (ProvLab. Candidates for the detection of all STEC serotypes include chromogenic agars, enzyme immunoassays (EIA and real-time polymerase chain reaction (qPCR. Culture methods allow further characterization of isolates, whereas qPCR provides the greatest sensitivity and specificity, followed by EIA. The virulence gene profiles using PCR arrays and stx gene subtypes can subsequently be determined. Different non-O157 serotypes exhibit markedly different virulence gene profiles and a greater prevalence of stx1 than stx2 subtypes compared to O157:H7 isolates. Finally, recent innovations in whole genome sequencing (WGS have allowed it to emerge as a candidate for the characterization and typing of STEC in diagnostic surveillance isolates. Methods of whole genome analysis such as single nucleotide polymorphisms and k-mer analysis are concordant with epidemiological data and standard typing methods, such as pulsed-field gel electrophoresis and multiple-locus variable number tandem repeat analysis while offering additional strain differentiation. Together these findings highlight improved strategies for STEC detection using currently available systems and the development of novel approaches for future surveillance.

  4. Noninvasive, optoacoustic detection and characterization of intra- and extracranial hematomas and cerebral hypoxia

    Science.gov (United States)

    Petrov, Andrey; Prough, Donald S.; Petrov, Yuriy; Petrov, Irene Y.; Robertson, Claudia S.; Asokan, Vasantha; Agbor, Adaeze; Esenaliev, Rinat O.

    2015-03-01

    Early diagnosis of intracranial hematomas is necessary to improve outcome in patients with traumatic brain injury (TBI). CT and MRI can diagnose intracranial hematomas, but cannot be used until the patient arrives at a major healthcare facility, resulting in delayed diagnosis. Near infrared spectroscopy may suggest the presence of unilateral intracranial hematomas, but provides minimal information on hematoma type and location due to limitations associated with strong light scattering. We have used optoacoustics (which combines high endogenous optical contrast with the resolution of ultrasound) to diagnose hematomas and monitor cerebral oxygenation. We performed animal and clinical studies on detection and characterization of hematomas and on monitoring cerebral hypoxia by probing the superior sagittal sinus (SSS). Recently, we built a medical grade, multi-wavelength, OPO-based optoacoustic system tunable in the near infrared spectral range. We developed new patient interfaces for noninvasive, transcranial measurements in the transmission mode in the presence of dense hair and used it in patients with TBI. The optoacoustic system was capable of detecting and characterizing intra- and extracranial hematomas. SSS blood oxygenation was measured as well with the new interface. The obtained results indicate that the optoacoustic system in the transmission mode provides detection and characterization of hematomas in TBI patients, as well as cerebral venous blood oxygenation monitoring. The transmission mode approach can be used for optoacoustic brain imaging, tomography, and mapping in humans.

  5. Comparison of Molecular and Phenotypic Methods for the Detection and Characterization of Carbapenem Resistant Enterobacteriaceae.

    Science.gov (United States)

    Somily, Ali M; Garaween, Ghada A; Abukhalid, Norah; Absar, Muhammad M; Senok, Abiola C

    2016-03-01

    In recent years, there has been a rapid dissemination of carbapenem resistant Enterobacteriaceae (CRE). This study aimed to compare phenotypic and molecular methods for detection and characterization of CRE isolates at a large tertiary care hospital in Saudi Arabia. This study was carried out between January 2011 and November 2013 at the King Khalid University Hospital (KKUH) in Saudi Arabia. Determination of presence of extended-spectrum beta-lactamases (ESBL) and carbapenem resistance was in accordance with Clinical and Laboratory Standards Institute (CLSI) guidelines. Phenotypic classification was done by the MASTDISCS(TM) ID inhibitor combination disk method. Genotypic characterization of ESBL and carbapenemase genes was performed by the Check-MDR CT102. Diversilab rep-PCR was used for the determination of clonal relationship. Of the 883 ESBL-positive Enterobacteriaceae detected during the study period, 14 (1.6%) isolates were carbapenem resistant. Both the molecular genotypic characterization and phenotypic testing were in agreement in the detection of all 8 metalo-beta-lactamases (MBL) producing isolates. Of these 8 MBL-producers, 5 were positive for blaNDM gene and 3 were positive for blaVIM gene. Molecular method identified additional blaOXA gene isolates while MASTDISCS(TM) ID detected one AmpC producer isolate. Both methods agreed in identifying 2 carbapenem resistant isolates which were negative for carbapenemase genes. Diversilab rep-PCR analysis of the 9 Klebsiella pneumoniae isolates revealed polyclonal distribution into eight clusters. MASTDISCS(TM) ID is a reliable simple cheap phenotypic method for detection of majority of carbapenemase genes with the exception of the blaOXA gene. We recommend to use such method in the clinical laboratory.

  6. Polarimetric Emission of Rain Events: Simulation and Experimental Results at X-Band

    Directory of Open Access Journals (Sweden)

    Nuria Duffo

    2009-06-01

    Full Text Available Accurate models are used today for infrared and microwave satellite radiance simulations of the first two Stokes elements in the physical retrieval, data assimilation etc. of surface and atmospheric parameters. Although in the past a number of theoretical and experimental works have studied the polarimetric emission of some natural surfaces, specially the sea surface roughened by the wind (Windsat mission, very limited studies have been conducted on the polarimetric emission of rain cells or other natural surfaces. In this work, the polarimetric emission (four Stokes elements of a rain cell is computed using the polarimetric radiative transfer equation assuming that raindrops are described by Pruppacher-Pitter shapes and that their size distribution follows the Laws-Parsons law. The Boundary Element Method (BEM is used to compute the exact bistatic scattering coefficients for each raindrop shape and different canting angles. Numerical results are compared to the Rayleigh or Mie scattering coefficients, and to Oguchi’s ones, showing that above 1-2 mm raindrop size the exact formulation is required to model properly the scattering. Simulation results using BEM are then compared to the experimental data gathered with a X-band polarimetric radiometer. It is found that the depolarization of the radiation caused by the scattering of non-spherical raindrops induces a non-zero third Stokes parameter, and the differential phase of the scattering coefficients induces a non-zero fourth Stokes parameter.

  7. Evaluation of Polarimetric SAR Decomposition for Classifying Wetland Vegetation Types

    Directory of Open Access Journals (Sweden)

    Sang-Hoon Hong

    2015-07-01

    Full Text Available The Florida Everglades is the largest subtropical wetland system in the United States and, as with subtropical and tropical wetlands elsewhere, has been threatened by severe environmental stresses. It is very important to monitor such wetlands to inform management on the status of these fragile ecosystems. This study aims to examine the applicability of TerraSAR-X quadruple polarimetric (quad-pol synthetic aperture radar (PolSAR data for classifying wetland vegetation in the Everglades. We processed quad-pol data using the Hong & Wdowinski four-component decomposition, which accounts for double bounce scattering in the cross-polarization signal. The calculated decomposition images consist of four scattering mechanisms (single, co- and cross-pol double, and volume scattering. We applied an object-oriented image analysis approach to classify vegetation types with the decomposition results. We also used a high-resolution multispectral optical RapidEye image to compare statistics and classification results with Synthetic Aperture Radar (SAR observations. The calculated classification accuracy was higher than 85%, suggesting that the TerraSAR-X quad-pol SAR signal had a high potential for distinguishing different vegetation types. Scattering components from SAR acquisition were particularly advantageous for classifying mangroves along tidal channels. We conclude that the typical scattering behaviors from model-based decomposition are useful for discriminating among different wetland vegetation types.

  8. Radiative Grain Alignment in Protoplanetary Disks: Implications for Polarimetric Observations

    Energy Technology Data Exchange (ETDEWEB)

    Tazaki, Ryo [Department of Astronomy, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606–8502 (Japan); Lazarian, Alexandre [Department of Astronomy, University of Wisconsin, Madison, WI 53706 (United States); Nomura, Hideko, E-mail: rtazaki@kusastro.kyoto-u.ac.jp [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152–8551 (Japan)

    2017-04-10

    We apply the theory of radiative torque (RAT) alignment for studying protoplanetary disks around a T-Tauri star and perform 3D radiative transfer calculations to provide the expected maps of polarized radiation to be compared with observations, such as with ALMA. We revisit the issue of grain alignment for large grains expected in the protoplanetary disks and find that mm-sized grains at the midplane do not align with the magnetic field since the Larmor precession timescale for such large grains becomes longer than the gaseous damping timescale. Hence, for these grains the RAT theory predicts that the alignment axis is determined by the grain precession with respect to the radiative flux. As a result, we expect that the polarization will be in the azimuthal direction for a face-on disk. It is also shown that if dust grains have superparamagnetic inclusions, magnetic field alignment is possible for (sub-)micron grains at the surface layer of disks, and this can be tested by mid-infrared polarimetric observations.

  9. Polarimetric study of the interstellar medium in Taurus Dark Clouds

    International Nuclear Information System (INIS)

    Hsu, J.

    1985-01-01

    An optical linear polarimetric survey was completed for more than 300 stars in an area of 6.5 0 x 10 0 toward the Taurus Dark Clouds Complex. It was found that the orientation of the magnetic field is roughly perpendicular to the elongation direction of the dust lanes, indicating cloud contraction along the magnetic field lines. The distance to the front edge of the dark clouds in Taurus is determined to be 126 pc. There is only insignificant amount of obscuring material between the cloud complex and the Sun. Besides the polarization data, the reddenings of about 250 stars were also obtained from the UBV photometry. The mean polarization to reddening ratio in the Taurus region is 4.6, which is similar to that of the general interstellar matter. The wavelengths of maximum polarization were determined for 30 stars in Taurus. They show an average value of lambda/sub max/ = 0.57 μm, which is only slightly higher than the mean value of the general interstellar medium, lambda/sub max/ = 0.55 μm. A few stars that show higher values of lambda/sub max/ are found near the small isolated regions of very high extinction. One such highly obscured small region where very complex long chain molecules have been discovered in the ratio spectra, is the Taurus Molecular Cloud 1

  10. Assessment of NDE Technologies for Detection and Characterization of Stress Corrosion Cracking in LWRs

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Ryan M.; Ramuhalli, Pradeep; Toloczko, Mychailo B.; Bond, Leonard J.; Montgomery, Robert O.

    2012-12-31

    Stress corrosion cracking (SCC) in light water reactors (LWRs) has been a persistent form of degradation in the nuclear industry. Examples of SCC can be found for a range of materials in boiling and pressurized water reactor environments, including carbon steels, stainless steels, and nickel-base stainless alloys. The evolution of SCC is often characterized by a long initiation stage followed by a phase of more rapid crack growth to failure. This provides a relatively short window of opportunity to detect the start of observable SCC, and it is conceivable that SCC could progress from initiation to failure between subsequent examinations when managed by applying periodic in-service inspection techniques. Implementation of advanced aging management paradigms in the current fleet of LWRs will require adaptation of existing measurement technologies and development of new technologies to perform on-line measurements during reactor operation to ensure timely detection of material degradation and to support the implementation of advanced diagnostics and prognostics. This paper considers several non-destructive examination (NDE) technologies with known sensitivity to detection of indicators for SCC initiation and/or propagation, and assesses these technologies with respect to their ability to detect and accurately characterize the significance of an SCC flaw. Potential strategies to improve SCC inspection or monitoring performance are offered to benefit management of SCC degradation in LWRs.

  11. Assessment of NDE technologies for detection and characterization of stress corrosion cracking in LWRs

    International Nuclear Information System (INIS)

    Meyer, R.M.; Ramuhalli, P.; Toloczko, M.B.; Bond, L.J.; Montgomery, R.O.

    2012-01-01

    Stress corrosion cracking (SCC) in light water reactors (LWRs) has been a persistent form of degradation in the nuclear industry. Examples of SCC can be found for a range of materials in boiling and pressurized water reactor environments, including carbon steels, stainless steels, and nickel-base alloys. The evolution of SCC is often characterized by a long initiation stage followed by a phase of more rapid crack growth to failure. This provides a relatively short window of opportunity to detect the start of observable SCC, and it is conceivable that SCC could progress from initiation to failure between subsequent examinations when managed by applying periodic in-service inspection techniques. Implementation of advanced aging management paradigms in the current fleet of LWRs will require adaptation of existing measurement technologies and development of new technologies to perform on-line measurements during reactor operation to ensure timely detection of material degradation and to support the implementation of advanced diagnostics and prognostics. This paper considers several non-destructive examination (NDE) technologies with known sensitivity to detection of indicators for SCC initiation and/or propagation, and assesses these technologies with respect to their ability to detect and accurately characterize the significance of an SCC flaw. Potential strategies to improve SCC inspection or monitoring performance are offered to benefit management of SCC degradation in LWRs. (author)

  12. Characterizing Android apps’ behavior for effective detection of malapps at large scale

    KAUST Repository

    Wang, Xing

    2017-05-06

    Android malicious applications (malapps) have surged and been sophisticated, posing a great threat to users. How to characterize, understand and detect Android malapps at a large scale is thus a big challenge. In this work, we are motivated to discover the discriminatory and persistent features extracted from Android APK files for automated malapp detection at a large scale. To achieve this goal, firstly we extract a very large number of features from each app and categorize the features into two groups, namely, app-specific features as well as platform-defined features. These feature sets will then be fed into four classifiers (i.e., Logistic Regression, linear SVM, Decision Tree and Random Forest) for the detection of malapps. Secondly, we evaluate the persistence of app-specific and platform-defined features on classification performance with two data sets collected in different time periods. Thirdly, we comprehensively analyze the relevant features selected by Logistic Regression classifier to identify the contributions of each feature set. We conduct extensive experiments on large real-world app sets consisting of 213,256 benign apps collected from six app markets, 4,363 benign apps from Google Play market, and 18,363 malapps. The experimental results and our analysis give insights regarding what discriminatory features are most effective to characterize malapps for building an effective and efficient malapp detection system. With the selected discriminatory features, the Logistic Regression classifier yields the best true positive rate as 96% with a false positive rate as 0.06%.

  13. Detection and Molecular Characterization of Gemycircularvirus from Environmental Samples in Brazil.

    Science.gov (United States)

    da Silva Assis, Matheus Ribeiro; Vieira, Carmen Baur; Fioretti, Julia Monassa; Rocha, Mônica Simões; de Almeida, Pedro Ivo Neves; Miagostovich, Marize Pereira; Fumian, Tulio Machado

    2016-12-01

    Gemycircularvirus (GemyCV) is a group of viruses which has been recently proposed as a new viral genus detected in fecal and environmental samples around the world. GemyCVs have been detected in human blood, brain tissue, cerebrospinal fluid, and stool sample. In the present study, we demonstrate for the first time, through molecular detection and characterization, the presence of GemyCVs in environmental samples from Brazil. Our results show a percentage of positivity ranging from 69 (25/36) to 97 % (35/36) in river water samples collected in Manaus, Amazon region, and wastewater from a wastewater treatment plant located in Rio de Janeiro, respectively, revealing GemyCVs as an important environmental contaminant.

  14. Topological data analyses and machine learning for detection, classification and characterization of atmospheric rivers

    Science.gov (United States)

    Muszynski, G.; Kashinath, K.; Wehner, M. F.; Prabhat, M.; Kurlin, V.

    2017-12-01

    We investigate novel approaches to detecting, classifying and characterizing extreme weather events, such as atmospheric rivers (ARs), in large high-dimensional climate datasets. ARs are narrow filaments of concentrated water vapour in the atmosphere that bring much of the precipitation in many mid-latitude regions. The precipitation associated with ARs is also responsible for major flooding events in many coastal regions of the world, including the west coast of the United States and western Europe. In this study we combine ideas from Topological Data Analysis (TDA) with Machine Learning (ML) for detecting, classifying and characterizing extreme weather events, like ARs. TDA is a new field that sits at the interface between topology and computer science, that studies "shape" - hidden topological structure - in raw data. It has been applied successfully in many areas of applied sciences, including complex networks, signal processing and image recognition. Using TDA we provide ARs with a shape characteristic as a new feature descriptor for the task of AR classification. In particular, we track the change in topology in precipitable water (integrated water vapour) fields using the Union-Find algorithm. We use the generated feature descriptors with ML classifiers to establish reliability and classification performance of our approach. We utilize the parallel toolkit for extreme climate events analysis (TECA: Petascale Pattern Recognition for Climate Science, Prabhat et al., Computer Analysis of Images and Patterns, 2015) for comparison (it is assumed that events identified by TECA is ground truth). Preliminary results indicate that our approach brings new insight into the study of ARs and provides quantitative information about the relevance of topological feature descriptors in analyses of a large climate datasets. We illustrate this method on climate model output and NCEP reanalysis datasets. Further, our method outperforms existing methods on detection and

  15. Exploration of a Polarized Surface Bidirectional Reflectance Model Using the Ground-Based Multiangle SpectroPolarimetric Imager

    Directory of Open Access Journals (Sweden)

    David J. Diner

    2012-12-01

    Full Text Available Accurate characterization of surface reflection is essential for retrieval of aerosols using downward-looking remote sensors. In this paper, observations from the Ground-based Multiangle SpectroPolarimetric Imager (GroundMSPI are used to evaluate a surface polarized bidirectional reflectance distribution function (PBRDF model. GroundMSPI is an eight-band spectropolarimetric camera mounted on a rotating gimbal to acquire pushbroom imagery of outdoor landscapes. The camera uses a very accurate photoelastic-modulator-based polarimetric imaging technique to acquire Stokes vector measurements in three of the instrument’s bands (470, 660, and 865 nm. A description of the instrument is presented, and observations of selected targets within a scene acquired on 6 January 2010 are analyzed. Data collected during the course of the day as the Sun moved across the sky provided a range of illumination geometries that facilitated evaluation of the surface model, which is comprised of a volumetric reflection term represented by the modified Rahman-Pinty-Verstraete function plus a specular reflection term generated by a randomly oriented array of Fresnel-reflecting microfacets. While the model is fairly successful in predicting the polarized reflection from two grass targets in the scene, it does a poorer job for two manmade targets (a parking lot and a truck roof, possibly due to their greater degree of geometric organization. Several empirical adjustments to the model are explored and lead to improved fits to the data. For all targets, the data support the notion of spectral invariance in the angular shape of the unpolarized and polarized surface reflection. As noted by others, this behavior provides valuable constraints on the aerosol retrieval problem, and highlights the importance of multiangle observations.

  16. The Potential of Polarimetric and Compact SAR Data in Rice Identification

    International Nuclear Information System (INIS)

    Shao, Y; Li, K; Liu, L; Yang, Z; Brisco, B

    2014-01-01

    Rice is a major food staple in the world, and provides food for more than one-third of the global population. The monitoring and mapping of paddy rice in a timely and efficient manner is very important for governments and decision makers. Synthetic Aperture Radar (SAR) has been proved to be a significant data source in rice monitoring. In this study, RADARSAT-2 polarimetric data were used to simulate compact polarimetry data. The simulated compact data and polarimetric data were then used to evaluate the information content for rice identification. The results indicate that polarimetric SAR can be used for rice identification based on the scattering mechanisms. The compact polarization RH and the RH/RL ratio are very promising for the discrimination of transplanted rice and direct-sown rice. These results require verification in further research

  17. The Effect of Topography on Target Decomposition of Polarimetric SAR Data

    Directory of Open Access Journals (Sweden)

    Sang-Eun Park

    2015-04-01

    Full Text Available Polarimetric target decomposition enables the interpretation of radar images more easily, mostly based on physical assumptions, i.e., fitting physically-based scattering models to the polarimetric SAR observations. However, the model-fitting result cannot be always successful. Particularly, the performance of model-fitting in sloping forests is still an open question. In this study, the effect of ground topography on the model-fitting-based polarimetric decomposition techniques is investigated. The estimation accuracy of each scattering component in the decomposition results are evaluated based on the simulated target matrix by using the incoherent vegetation scattering model that accounts for the tilted scattering surface beneath the forest canopy. Experimental results show that the surface and the double-bounce scattering components can be significantly misestimated due to the topographic slope, even when the volume scattering power is successfully estimated.

  18. Polarimetric SAR Image Classification Using Multiple-feature Fusion and Ensemble Learning

    Directory of Open Access Journals (Sweden)

    Sun Xun

    2016-12-01

    Full Text Available In this paper, we propose a supervised classification algorithm for Polarimetric Synthetic Aperture Radar (PolSAR images using multiple-feature fusion and ensemble learning. First, we extract different polarimetric features, including extended polarimetric feature space, Hoekman, Huynen, H/alpha/A, and fourcomponent scattering features of PolSAR images. Next, we randomly select two types of features each time from all feature sets to guarantee the reliability and diversity of later ensembles and use a support vector machine as the basic classifier for predicting classification results. Finally, we concatenate all prediction probabilities of basic classifiers as the final feature representation and employ the random forest method to obtain final classification results. Experimental results at the pixel and region levels show the effectiveness of the proposed algorithm.

  19. Fast polarimetric dehazing method for visibility enhancement in HSI colour space

    Science.gov (United States)

    Zhang, Wenfei; Liang, Jian; Ren, Liyong; Ju, Haijuan; Bai, Zhaofeng; Wu, Zhaoxin

    2017-09-01

    Image haze removal has attracted much attention in optics and computer vision fields in recent years due to its wide applications. In particular, the fast and real-time dehazing methods are of significance. In this paper, we propose a fast dehazing method in hue, saturation and intensity colour space based on the polarimetric imaging technique. We implement the polarimetric dehazing method in the intensity channel, and the colour distortion of the image is corrected using the white patch retinex method. This method not only reserves the detailed information restoration capacity, but also improves the efficiency of the polarimetric dehazing method. Comparison studies with state of the art methods demonstrate that the proposed method obtains equal or better quality results and moreover the implementation is much faster. The proposed method is promising in real-time image haze removal and video haze removal applications.

  20. Direct 13C-detected NMR experiments for mapping and characterization of hydrogen bonds in RNA

    International Nuclear Information System (INIS)

    Fürtig, Boris; Schnieders, Robbin; Richter, Christian; Zetzsche, Heidi; Keyhani, Sara; Helmling, Christina; Kovacs, Helena; Schwalbe, Harald

    2016-01-01

    In RNA secondary structure determination, it is essential to determine whether a nucleotide is base-paired and not. Base-pairing of nucleotides is mediated by hydrogen bonds. The NMR characterization of hydrogen bonds relies on experiments correlating the NMR resonances of exchangeable protons and can be best performed for structured parts of the RNA, where labile hydrogen atoms are protected from solvent exchange. Functionally important regions in RNA, however, frequently reveal increased dynamic disorder which often leads to NMR signals of exchangeable protons that are broadened beyond 1 H detection. Here, we develop 13 C direct detected experiments to observe all nucleotides in RNA irrespective of whether they are involved in hydrogen bonds or not. Exploiting the self-decoupling of scalar couplings due to the exchange process, the hydrogen bonding behavior of the hydrogen bond donor of each individual nucleotide can be determined. Furthermore, the adaption of HNN-COSY experiments for 13 C direct detection allows correlations of donor–acceptor pairs and the localization of hydrogen-bond acceptor nucleotides. The proposed 13 C direct detected experiments therefore provide information about molecular sites not amenable by conventional proton-detected methods. Such information makes the RNA secondary structure determination by NMR more accurate and helps to validate secondary structure predictions based on bioinformatics.

  1. Detecting Different Road Infrastructural Elements Based on the Stochastic Characterization of Speed Patterns

    Directory of Open Access Journals (Sweden)

    Mario Muñoz-Organero

    2017-01-01

    Full Text Available The automatic detection of road related information using data from sensors while driving has many potential applications such as traffic congestion detection or automatic routable map generation. This paper focuses on the automatic detection of road elements based on GPS data from on-vehicle systems. A new algorithm is developed that uses the total variation distance instead of the statistical moments to improve the classification accuracy. The algorithm is validated for detecting traffic lights, roundabouts, and street-crossings in a real scenario and the obtained accuracy (0.75 improves the best results using previous approaches based on statistical moments based features (0.71. Each road element to be detected is characterized as a vector of speeds measured when a driver goes through it. We first eliminate the speed samples in congested traffic conditions which are not comparable with clear traffic conditions and would contaminate the dataset. Then, we calculate the probability mass function for the speed (in 1 m/s intervals at each point. The total variation distance is then used to find the similarity among different points of interest (which can contain a similar road element or a different one. Finally, a k-NN approach is used for assigning a class to each unlabelled element.

  2. Detection and Characterization of Flaws in Sprayed on Foam Insulation with Pulsed Terahertz Frequency Electromagnetic Waves

    Science.gov (United States)

    Winfree, William P.; Madaras, Eric I.

    2005-01-01

    The detection and repair of flaws such as voids and delaminations in the sprayed on foam insulation of the external tank reduces the probability of foam debris during shuttle ascent. The low density of sprayed on foam insulation along with it other physical properties makes detection of flaws difficult with conventional techniques. An emerging technology that has application for quantitative evaluation of flaws in the foam is pulsed electromagnetic waves at terahertz frequencies. The short wavelengths of these terahertz pulses make them ideal for imaging flaws in the foam. This paper examines the application of terahertz pulses for flaw detection in foam characteristic of the foam insulation of the external tank. Of particular interest is the detection of voids and delaminations, encapsulated in the foam or at the interface between the foam and a metal backing. The technique is shown to be capable of imaging small voids and delaminations through as much as 20 cm of foam. Methods for reducing the temporal responses of the terahertz pulses to improve flaw detection and yield quantitative characterizations of the size and location of the flaws are discussed.

  3. THE IMPLICATIONS OF M DWARF FLARES ON THE DETECTION AND CHARACTERIZATION OF EXOPLANETS AT INFRARED WAVELENGTHS

    International Nuclear Information System (INIS)

    Tofflemire, Benjamin M.; Wisniewski, John P.; Kowalski, Adam F.; Schmidt, Sarah J.; Kundurthy, Praveen; Hilton, Eric J.; Hawley, Suzanne L.; Holtzman, Jon A.

    2012-01-01

    We present the results of an observational campaign which obtained high-cadence, high-precision, simultaneous optical and IR photometric observations of three M dwarf flare stars for 47 hr. The campaign was designed to characterize the behavior of energetic flare events, which routinely occur on M dwarfs, at IR wavelengths to millimagnitude precision, and quantify to what extent such events might influence current and future efforts to detect and characterize extrasolar planets surrounding these stars. We detected and characterized four highly energetic optical flares having U-band total energies of ∼7.8 × 10 30 to ∼1.3 × 10 32 erg, and found no corresponding response in the J, H, or Ks bandpasses at the precision of our data. For active dM3e stars, we find that a ∼1.3 × 10 32 erg U-band flare (ΔU max ∼ 1.5 mag) will induce 31 erg U-band flare (ΔU max ∼ 1.6 mag) will induce <7.8 (J), <8.8 (H), and <5.1 (Ks) mmag of a response. A flare of this energy or greater should occur less than once per 10 hr. No evidence of stellar variability not associated with discrete flare events was observed at the level of ∼3.9 mmag over 1 hr timescales and at the level of ∼5.6 mmag over 7.5 hr timescales. We therefore demonstrate that most M dwarf stellar activity and flares will not influence IR detection and characterization studies of M dwarf exoplanets above the level of ∼5-11 mmag, depending on the filter and spectral type. We speculate that the most energetic megaflares on M dwarfs, which occur at rates of once per month, are likely to be easily detected in IR observations with sensitivity of tens of millimagnitudes. We also discuss how recent detections of line flux enhancements during M dwarf flares could influence IR transmission spectroscopic observations of M dwarf exoplanets.

  4. THE IMPLICATIONS OF M DWARF FLARES ON THE DETECTION AND CHARACTERIZATION OF EXOPLANETS AT INFRARED WAVELENGTHS

    Energy Technology Data Exchange (ETDEWEB)

    Tofflemire, Benjamin M.; Wisniewski, John P.; Kowalski, Adam F.; Schmidt, Sarah J.; Kundurthy, Praveen; Hilton, Eric J.; Hawley, Suzanne L. [Astronomy Department, University of Washington, Box 351580, Seattle, WA 98195 (United States); Holtzman, Jon A., E-mail: tofflb@u.washington.edu, E-mail: jwisnie@u.washington.edu [Department of Astronomy, New Mexico State University, Box 30001, Las Cruces, NM 880033 (United States)

    2012-01-15

    We present the results of an observational campaign which obtained high-cadence, high-precision, simultaneous optical and IR photometric observations of three M dwarf flare stars for 47 hr. The campaign was designed to characterize the behavior of energetic flare events, which routinely occur on M dwarfs, at IR wavelengths to millimagnitude precision, and quantify to what extent such events might influence current and future efforts to detect and characterize extrasolar planets surrounding these stars. We detected and characterized four highly energetic optical flares having U-band total energies of {approx}7.8 Multiplication-Sign 10{sup 30} to {approx}1.3 Multiplication-Sign 10{sup 32} erg, and found no corresponding response in the J, H, or Ks bandpasses at the precision of our data. For active dM3e stars, we find that a {approx}1.3 Multiplication-Sign 10{sup 32} erg U-band flare ({Delta}U{sub max} {approx} 1.5 mag) will induce <8.3 (J), <8.5 (H), and <11.7 (Ks) mmag of a response. A flare of this energy or greater should occur less than once per 18 hr. For active dM4.5e stars, we find that a {approx}5.1 Multiplication-Sign 10{sup 31} erg U-band flare ({Delta}U{sub max} {approx} 1.6 mag) will induce <7.8 (J), <8.8 (H), and <5.1 (Ks) mmag of a response. A flare of this energy or greater should occur less than once per 10 hr. No evidence of stellar variability not associated with discrete flare events was observed at the level of {approx}3.9 mmag over 1 hr timescales and at the level of {approx}5.6 mmag over 7.5 hr timescales. We therefore demonstrate that most M dwarf stellar activity and flares will not influence IR detection and characterization studies of M dwarf exoplanets above the level of {approx}5-11 mmag, depending on the filter and spectral type. We speculate that the most energetic megaflares on M dwarfs, which occur at rates of once per month, are likely to be easily detected in IR observations with sensitivity of tens of millimagnitudes. We also

  5. Polymer nanocomposite nanomechanical cantilever sensors: material characterization, device development and application in explosive vapour detection

    International Nuclear Information System (INIS)

    Seena, V; Fernandes, Avil; Ramgopal Rao, V; Pant, Prita; Mukherji, Soumyo

    2011-01-01

    This paper reports an optimized and highly sensitive piezoresistive SU-8 nanocomposite microcantilever sensor and its application for detection of explosives in vapour phase. The optimization has been in improving its electrical, mechanical and transduction characteristics. We have achieved a better dispersion of carbon black (CB) in the SU-8/CB nanocomposite piezoresistor and arrived at an optimal range of 8-9 vol% CB concentration by performing a systematic mechanical and electrical characterization of polymer nanocomposites. Mechanical characterization of SU-8/CB nanocomposite thin films was performed using the nanoindentation technique with an appropriate substrate effect analysis. Piezoresistive microcantilevers having an optimum carbon black concentration were fabricated using a design aimed at surface stress measurements with reduced fabrication process complexity. The optimal range of 8-9 vol% CB concentration has resulted in an improved sensitivity, low device variability and low noise level. The resonant frequency and spring constant of the microcantilever were found to be 22 kHz and 0.4 N m -1 respectively. The devices exhibited a surface stress sensitivity of 7.6 ppm (mN m -1 ) -1 and the noise characterization results support their suitability for biochemical sensing applications. This paper also reports the ability of the sensor in detecting TNT vapour concentration down to less than six parts per billion with a sensitivity of 1 mV/ppb.

  6. Polymer nanocomposite nanomechanical cantilever sensors: material characterization, device development and application in explosive vapour detection

    Energy Technology Data Exchange (ETDEWEB)

    Seena, V; Fernandes, Avil; Ramgopal Rao, V [Centre for Excellence in Nanoelectronics, Department of Electrical Engineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra (India); Pant, Prita [Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai, Maharashtra (India); Mukherji, Soumyo, E-mail: seenapradeep@iitb.ac.in, E-mail: rrao@ee.iitb.ac.in [Department of Biosciences and Bio-engineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra (India)

    2011-07-22

    This paper reports an optimized and highly sensitive piezoresistive SU-8 nanocomposite microcantilever sensor and its application for detection of explosives in vapour phase. The optimization has been in improving its electrical, mechanical and transduction characteristics. We have achieved a better dispersion of carbon black (CB) in the SU-8/CB nanocomposite piezoresistor and arrived at an optimal range of 8-9 vol% CB concentration by performing a systematic mechanical and electrical characterization of polymer nanocomposites. Mechanical characterization of SU-8/CB nanocomposite thin films was performed using the nanoindentation technique with an appropriate substrate effect analysis. Piezoresistive microcantilevers having an optimum carbon black concentration were fabricated using a design aimed at surface stress measurements with reduced fabrication process complexity. The optimal range of 8-9 vol% CB concentration has resulted in an improved sensitivity, low device variability and low noise level. The resonant frequency and spring constant of the microcantilever were found to be 22 kHz and 0.4 N m{sup -1} respectively. The devices exhibited a surface stress sensitivity of 7.6 ppm (mN m{sup -1}){sup -1} and the noise characterization results support their suitability for biochemical sensing applications. This paper also reports the ability of the sensor in detecting TNT vapour concentration down to less than six parts per billion with a sensitivity of 1 mV/ppb.

  7. Polymer nanocomposite nanomechanical cantilever sensors: material characterization, device development and application in explosive vapour detection.

    Science.gov (United States)

    Seena, V; Fernandes, Avil; Pant, Prita; Mukherji, Soumyo; Rao, V Ramgopal

    2011-07-22

    This paper reports an optimized and highly sensitive piezoresistive SU-8 nanocomposite microcantilever sensor and its application for detection of explosives in vapour phase. The optimization has been in improving its electrical, mechanical and transduction characteristics. We have achieved a better dispersion of carbon black (CB) in the SU-8/CB nanocomposite piezoresistor and arrived at an optimal range of 8-9 vol% CB concentration by performing a systematic mechanical and electrical characterization of polymer nanocomposites. Mechanical characterization of SU-8/CB nanocomposite thin films was performed using the nanoindentation technique with an appropriate substrate effect analysis. Piezoresistive microcantilevers having an optimum carbon black concentration were fabricated using a design aimed at surface stress measurements with reduced fabrication process complexity. The optimal range of 8-9 vol% CB concentration has resulted in an improved sensitivity, low device variability and low noise level. The resonant frequency and spring constant of the microcantilever were found to be 22 kHz and 0.4 N m(-1) respectively. The devices exhibited a surface stress sensitivity of 7.6 ppm (mN m(-1))(-1) and the noise characterization results support their suitability for biochemical sensing applications. This paper also reports the ability of the sensor in detecting TNT vapour concentration down to less than six parts per billion with a sensitivity of 1 mV/ppb.

  8. The evolution of advanced molecular diagnostics for the detection and characterization of Mycoplasma pneumoniae

    Directory of Open Access Journals (Sweden)

    Maureen H. Diaz

    2016-03-01

    Full Text Available Over the past several years there have been significant advancements in the methods used for detecting and characterizing Mycoplasma pneumoniae, a common cause of respiratory illness and community-acquired pneumonia worldwide. The repertoire of available molecular diagnostics has greatly expanded from nucleic acid amplification techniques (NAATs that encompass a variety of chemistries used for detection, to more sophisticated characterizing methods such as multi-locus variable-number tandem-repeat analysis and sequencing typing (MLVA and MLST, respectively, matrix-assisted laser desorption ionization–time-of-flight mass spectrometry (MALDI-TOF MS, single nucleotide polymorphism (SNP typing, and numerous macrolide susceptibility profiling methods, among others. These many molecular-based approaches have been developed and employed to continually increase the level of discrimination and characterization in order to better understand the epidemiology and biology of M. pneumoniae. This review will summarize recent molecular techniques and procedures and lend perspective to how each has enhanced the current understanding of this organism and will emphasize how Next Generation Sequencing may serve as a resource for researchers to gain a more comprehensive understanding of the genomic complexities of this insidious pathogen.

  9. Detection and Physicochemical Characterization of Membrane Vesicles (MVs of Lactobacillus reuteri DSM 17938

    Directory of Open Access Journals (Sweden)

    Rossella Grande

    2017-06-01

    Full Text Available Membrane vesicles (MVs are bilayer structures which bleb from bacteria, and are important in trafficking biomolecules to other bacteria or host cells. There are few data about MVs produced by the Gram-positive commensal-derived probiotic Lactobacillus reuteri; however, MVs from this species may have potential therapeutic benefit. The aim of this study was to detect and characterize MVs produced from biofilm (bMVs, and planktonic (pMVs phenotypes of L. reuteri DSM 17938. MVs were analyzed for structure and physicochemical characterization by Scanning Electron Microscope (SEM and Dynamic Light Scattering (DLS. Their composition was interrogated using various digestive enzyme treatments and subsequent Transmission Electron Microscopy (TEM analysis. eDNA (extracellular DNA was detected and quantified using PicoGreen. We found that planktonic and biofilm of L. reuteri cultures generated MVs with a broad size distribution. Our data also showed that eDNA was associated with pMVs and bMVs (eMVsDNA. DNase I treatment demonstrated no modifications of MVs, suggesting that an eDNA-MVs complex protected the eMVsDNA. Proteinase K and Phospholipase C treatments modified the structure of MVs, showing that lipids and proteins are important structural components of L. reuteri MVs. The biological composition and the physicochemical characterization of MVs generated by the probiotic L. reuteri may represent a starting point for future applications in the development of vesicles-based therapeutic systems.

  10. The Evolution of Advanced Molecular Diagnostics for the Detection and Characterization of Mycoplasma pneumoniae.

    Science.gov (United States)

    Diaz, Maureen H; Winchell, Jonas M

    2016-01-01

    Over the past decade there have been significant advancements in the methods used for detecting and characterizing Mycoplasma pneumoniae, a common cause of respiratory illness and community-acquired pneumonia worldwide. The repertoire of available molecular diagnostics has greatly expanded from nucleic acid amplification techniques (NAATs) that encompass a variety of chemistries used for detection, to more sophisticated characterizing methods such as multi-locus variable-number tandem-repeat analysis (MLVA), Multi-locus sequence typing (MLST), matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS), single nucleotide polymorphism typing, and numerous macrolide susceptibility profiling methods, among others. These many molecular-based approaches have been developed and employed to continually increase the level of discrimination and characterization in order to better understand the epidemiology and biology of M. pneumoniae. This review will summarize recent molecular techniques and procedures and lend perspective to how each has enhanced the current understanding of this organism and will emphasize how Next Generation Sequencing may serve as a resource for researchers to gain a more comprehensive understanding of the genomic complexities of this insidious pathogen.

  11. Sensitivity of Climate Change Detection and Attribution to the Characterization of Internal Climate Variability

    KAUST Repository

    Imbers, Jara

    2014-05-01

    The Intergovernmental Panel on Climate Change\\'s (IPCC) "very likely" statement that anthropogenic emissions are affecting climate is based on a statistical detection and attribution methodology that strongly depends on the characterization of internal climate variability. In this paper, the authors test the robustness of this statement in the case of global mean surface air temperature, under different representations of such variability. The contributions of the different natural and anthropogenic forcings to the global mean surface air temperature response are computed using a box diffusion model. Representations of internal climate variability are explored using simple stochastic models that nevertheless span a representative range of plausible temporal autocorrelation structures, including the short-memory first-order autoregressive [AR(1)] process and the long-memory fractionally differencing process. The authors find that, independently of the representation chosen, the greenhouse gas signal remains statistically significant under the detection model employed in this paper. The results support the robustness of the IPCC detection and attribution statement for global mean temperature change under different characterizations of internal variability, but they also suggest that a wider variety of robustness tests, other than simple comparisons of residual variance, should be performed when dealing with other climate variables and/or different spatial scales. © 2014 American Meteorological Society.

  12. Sensitivity of Climate Change Detection and Attribution to the Characterization of Internal Climate Variability

    KAUST Repository

    Imbers, Jara; Lopez, Ana; Huntingford, Chris; Allen, Myles

    2014-01-01

    The Intergovernmental Panel on Climate Change's (IPCC) "very likely" statement that anthropogenic emissions are affecting climate is based on a statistical detection and attribution methodology that strongly depends on the characterization of internal climate variability. In this paper, the authors test the robustness of this statement in the case of global mean surface air temperature, under different representations of such variability. The contributions of the different natural and anthropogenic forcings to the global mean surface air temperature response are computed using a box diffusion model. Representations of internal climate variability are explored using simple stochastic models that nevertheless span a representative range of plausible temporal autocorrelation structures, including the short-memory first-order autoregressive [AR(1)] process and the long-memory fractionally differencing process. The authors find that, independently of the representation chosen, the greenhouse gas signal remains statistically significant under the detection model employed in this paper. The results support the robustness of the IPCC detection and attribution statement for global mean temperature change under different characterizations of internal variability, but they also suggest that a wider variety of robustness tests, other than simple comparisons of residual variance, should be performed when dealing with other climate variables and/or different spatial scales. © 2014 American Meteorological Society.

  13. Spike detection, characterization, and discrimination using feature analysis software written in LabVIEW.

    Science.gov (United States)

    Stewart, C M; Newlands, S D; Perachio, A A

    2004-12-01

    Rapid and accurate discrimination of single units from extracellular recordings is a fundamental process for the analysis and interpretation of electrophysiological recordings. We present an algorithm that performs detection, characterization, discrimination, and analysis of action potentials from extracellular recording sessions. The program was entirely written in LabVIEW (National Instruments), and requires no external hardware devices or a priori information about action potential shapes. Waveform events are detected by scanning the digital record for voltages that exceed a user-adjustable trigger. Detected events are characterized to determine nine different time and voltage levels for each event. Various algebraic combinations of these waveform features are used as axis choices for 2-D Cartesian plots of events. The user selects axis choices that generate distinct clusters. Multiple clusters may be defined as action potentials by manually generating boundaries of arbitrary shape. Events defined as action potentials are validated by visual inspection of overlain waveforms. Stimulus-response relationships may be identified by selecting any recorded channel for comparison to continuous and average cycle histograms of binned unit data. The algorithm includes novel aspects of feature analysis and acquisition, including higher acquisition rates for electrophysiological data compared to other channels. The program confirms that electrophysiological data may be discriminated with high-speed and efficiency using algebraic combinations of waveform features derived from high-speed digital records.

  14. A Methodology to Detect and Characterize Uplift Phenomena in Urban Areas Using Sentinel-1 Data

    Directory of Open Access Journals (Sweden)

    Roberta Bonì

    2018-04-01

    Full Text Available This paper presents a methodology to exploit the Persistent Scatterer Interferometry (PSI time series acquired by Sentinel-1 sensors for the detection and characterization of uplift phenomena in urban areas. The methodology has been applied to the Tower Hamlets Council area of London (United Kingdom using Sentinel-1 data covering the period 2015–2017. The test area is a representative high-urbanized site affected by geohazards due to natural processes such as compaction of recent deposits, and also anthropogenic causes due to groundwater management and engineering works. The methodology has allowed the detection and characterization of a 5 km2 area recording average uplift rates of 7 mm/year and a maximum rate of 18 mm/year in the period May 2015–March 2017. Furthermore, the analysis of the Sentinel-1 time series highlights that starting from August 2016 uplift rates began to decrease. A comparison between the uplift rates and urban developments as well as geological, geotechnical, and hydrogeological factors suggests that the ground displacements occur in a particular geological context and are mainly attributed to the swelling of clayey soils. The detected uplift could be attributed to a transient effect of the groundwater rebound after completion of dewatering works for the recent underground constructions.

  15. Pulsed magnetic flux leakage method for hairline crack detection and characterization

    Science.gov (United States)

    Okolo, Chukwunonso K.; Meydan, Turgut

    2018-04-01

    The Magnetic Flux leakage (MFL) method is a well-established branch of electromagnetic Non-Destructive Testing (NDT), extensively used for evaluating defects both on the surface and far-surface of pipeline structures. However the conventional techniques are not capable of estimating their approximate size, location and orientation, hence an additional transducer is required to provide the extra information needed. This research is aimed at solving the inevitable problem of granular bond separation which occurs during manufacturing, leaving pipeline structures with miniature cracks. It reports on a quantitative approach based on the Pulsed Magnetic Flux Leakage (PMFL) method, for the detection and characterization of the signals produced by tangentially oriented rectangular surface and far-surface hairline cracks. This was achieved through visualization and 3D imaging of the leakage field. The investigation compared finite element numerical simulation with experimental data. Experiments were carried out using a 10mm thick low carbon steel plate containing artificial hairline cracks with various depth sizes, and different features were extracted from the transient signal. The influence of sensor lift-off and pulse width variation on the magnetic field distribution which affects the detection capability of various hairline cracks located at different depths in the specimen is explored. The findings show that the proposed technique can be used to classify both surface and far-surface hairline cracks and can form the basis for an enhanced hairline crack detection and characterization for pipeline health monitoring.

  16. From experiment to design -- Fault characterization and detection in parallel computer systems using computational accelerators

    Science.gov (United States)

    Yim, Keun Soo

    This dissertation summarizes experimental validation and co-design studies conducted to optimize the fault detection capabilities and overheads in hybrid computer systems (e.g., using CPUs and Graphics Processing Units, or GPUs), and consequently to improve the scalability of parallel computer systems using computational accelerators. The experimental validation studies were conducted to help us understand the failure characteristics of CPU-GPU hybrid computer systems under various types of hardware faults. The main characterization targets were faults that are difficult to detect and/or recover from, e.g., faults that cause long latency failures (Ch. 3), faults in dynamically allocated resources (Ch. 4), faults in GPUs (Ch. 5), faults in MPI programs (Ch. 6), and microarchitecture-level faults with specific timing features (Ch. 7). The co-design studies were based on the characterization results. One of the co-designed systems has a set of source-to-source translators that customize and strategically place error detectors in the source code of target GPU programs (Ch. 5). Another co-designed system uses an extension card to learn the normal behavioral and semantic execution patterns of message-passing processes executing on CPUs, and to detect abnormal behaviors of those parallel processes (Ch. 6). The third co-designed system is a co-processor that has a set of new instructions in order to support software-implemented fault detection techniques (Ch. 7). The work described in this dissertation gains more importance because heterogeneous processors have become an essential component of state-of-the-art supercomputers. GPUs were used in three of the five fastest supercomputers that were operating in 2011. Our work included comprehensive fault characterization studies in CPU-GPU hybrid computers. In CPUs, we monitored the target systems for a long period of time after injecting faults (a temporally comprehensive experiment), and injected faults into various types of

  17. Investigating the Innermost Jet Structures of Blazar S5 0716+714 Using Uniquely Dense Intra-day Photo-polarimetric Observations

    Directory of Open Access Journals (Sweden)

    Gopal Bhatta

    2016-10-01

    Full Text Available The sub-hour timescale variability commonly observed in blazars—widely known as intra-day or microvariability—has been extensively studied in optical photo-polarimetric bands over the past 25–30 years. In addition, there have been comprehensive theoretical discussions on the topic, with various models and scenarios proposed; however, the phenomenon still remains relatively poorly understood. Here we present the summary of our optical microvariability studies over the past few years based on multi-frequency photo-polarimetric Whole Earth Blazar Telescope (WEBT observation campaigns. The primary objective of the study was to explore the characteristics of the source microvariability on timescales of a few minutes to a few days using exceptionally dense photo-polarimetric observations. The results show that the source often displays fast variability with an amplitude as large as 0.3 mag within a few hours, as well as color variability on similar time scales often characterized by “bluer-when-brighter” trend. Similarly, the correlation between variability in flux and polarization appears to depend upon the configuration of the optical polarization angle relative to the positional angle of the innermost radio core of the jet. Other fascinating observations include a sudden and temporary disappearance in the observed variability lasting for ∼6 h. In addition, the modeling of individual microflares strongly suggests that the phenomenon of microvariability can be best explained by convolved emission from compact emission sites distributed stochastically in the turbulent jet. Besides, analysis of some of the well resolved micro-flares exhibiting high degrees of polarization points towards a complex magnetic geometry pervading the jet with the possible presence of small-scale regions of highly ordered and enhanced magnetic field similar to so-called “magnetic islands”.

  18. Comparison between Multitemporal and Polarimetric SAR Data for Land Cover Classification

    DEFF Research Database (Denmark)

    Skriver, Henning

    2008-01-01

    The investigation focuses on the determination of the land cover type using SAR data, including single polarisation, dual polarisation and fully polarimetric data, at L-band. The analysed data set was acquired during the AgriSAR 2006 campaign by the airborne ESAR system over the Gormin agricultural...... site (Northeast Germany). The multitemporal acquisitions significantly improve the classification results for single and dual polarization configurations. The best results for the single and dual polarization configurations are better than for the polarimetric mode. Overall, the cross...

  19. The first international workshop on "Advancement of POLarimetric Observations: calibration and improved aerosol retrievals": APOLO-2017

    Science.gov (United States)

    Dubovik, Oleg; Li, Zhengqiang; Mishchenko, Michael I.

    2018-06-01

    The international workshop on "Advancement of POLarimetric Observations: calibration and improved aerosol retrievals-2017" (APOLO-2017) took place in Hefei, China on 24 - 27 October 2017. This was the inaugural meeting of a planned series of workshops on satellite polarimetry aimed at addressing the rapidly growing interest of the scientific community in polarimetric remote-sensing observations from space. The workshop was held at the Anhui Institute of Optics and Fine Mechanics, Hefei, widely known for 15 years of experience in the development of research polarimetry sensors and for hosting the building in parallel of several orbital polarimeters.

  20. OPTICAL PHOTOMETRIC AND POLARIMETRIC INVESTIGATION OF NGC 1931

    International Nuclear Information System (INIS)

    Pandey, A. K.; Eswaraiah, C.; Sharma, Saurabh; Yadav, Ram Kesh; Samal, M. R.; Chauhan, N.; Chen, W. P.; Jose, J.; Ojha, D. K.; Chandola, H. C.

    2013-01-01

    We present optical photometric and polarimetric observations of stars toward NGC 1931 with the aim of deriving cluster parameters such as distance, reddening, age, and luminosity/mass function as well as understanding dust properties and star formation in the region. The distance to the cluster is found to be 2.3 ± 0.3 kpc and the reddening E(B – V) in the region is found to be variable. The stellar density contours reveal two clusters in the region. The observations suggest a differing reddening law within the cluster region. Polarization efficiency of the dust grains toward the direction of the cluster is found to be less than that for the general diffuse interstellar medium (ISM). The slope of the mass function (–0.98 ± 0.22) in the southern region in the mass range of 0.8 ☉ < 9.8 is found to be shallower in comparison to that in the northern region (–1.26 ± 0.23), which is comparable to the Salpeter value (–1.35). The K-band luminosity function (KLF) of the region is found to be comparable to the average value of the slope (∼0.4) for young clusters obtained by Lada and Lada; however, the slope of the KLF is steeper in the northern region as compared to the southern region. The region is probably ionized by two B2 main-sequence-type stars. The mean age of the young stellar objects (YSOs) is found to be 2 ± 1 Myr, which suggests that the identified YSOs could be younger than the ionizing sources of the region. The morphology of the region, the distribution and ages of the YSOs, and ionizing sources indicate a triggered star formation in the region.

  1. Passive neutron interrogation in systems with a poorly characterized detection efficiency

    International Nuclear Information System (INIS)

    Dubi, Chen; Oster, Elad; Ocherashvilli, Aharon; Pedersen, Bent; Hutszy, Janus

    2014-01-01

    Passive neutron interrogation for fissile mass estimation, relying on neutrons coming from spontaneous fission events, is considered a standard NDT procedure in the nuclear safeguard and safety community. Since most structure materials are (relatively) transparent to neutron radiation, passive neutron interrogation is considered highly effective in the analysis of dirty, poorly characterized samples. On the other hand, since a typical passive interrogation assembly is based on 3He detectors, neutrons from additional neutron sources (mainly (α,n) reactions and induced fissions in the tested sample) cannot be separated from the main spontaneous fission source through energetic spectral analysis. There for, applying the passive interrogation methods the implementation of Neutron Multiplicity Counting (NMC) methods for separation between the main fission source and the additional sources. Applying NMC methods requires a well characterized system, in the sense that both system die away time and detection efficiency must be well known (and in particular, independent of the tested sample)

  2. Study and characterization of III-V semiconductor materials for applications in ionizing radiation detection

    International Nuclear Information System (INIS)

    Moulin, H.

    1989-11-01

    The photoconduction in the bulk of the gallium arsenide (GaAs) and of the indium phosphide doped with iron (InP:Fe) is investigated. These semiconductor materials are to be applied in X rays detection. The photoconduction theory and the physical characteristics of those materials are reviewed. The computer simulation models for studying the photoconductor responses to the radiation pulses are described. The experimental results are discussed. They include the following aspects: the characterization of the GaAs and InP:Fe, in the obscurity, as a function of the polarized electric field and of the neutrons dose; the characterization under X ray. Continuous X rays and pulsed synchrotron radiation are applied [fr

  3. Contrast-enhanced ultrasonography and spiral computed tomography in the detection and characterization of portal vein thrombosis complicating hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Sandro; Ghittoni, Giorgia; Ravetta, Valentina; Torello Viera, Francesca; Rosa, Laura [Policlinico ' S. Matteo' Foundation, IRCCS, VI Department of Internal Medicine and Interventional Ultrasonography, Pavia (Italy); Serassi, Martina; Scabini, Mara; Vercelli, Alessandro; Calliada, Fabrizio [IRCCS Policlinico ' S. Matteo' , Department of Radiology, P.le Golgi n. 19, Pavia (Italy); Tinelli, Carmine [Biometrics Unit, IRCCS Policlinico ' S. Matteo' , Pavia (Italy); Dal Bello, Barbara [IRCCS Policlinico ' S. Matteo' , Department of Human Pathology, Pavia (Italy); Burns, Peter N. [University of Toronto, Department of Medical Biophysics, Toronto, ON (Canada); Imaging Research S660, Sunnybrook Health Science Centre, Toronto, ON (Canada)

    2008-08-15

    The aim was to compare the performances of contrast-enhanced (CE) ultrasonography (US) and spiral computed tomography (CT) in the detection and characterization of portal vein thrombosis complicating hepatocellular carcinoma (HCC). We studied 50 patients with HCC who had biopsy-proven portal vein thrombi that had been detected with US and color Doppler US. Thirteen of the thrombi involved the main portal trunk and 37 the segmental branches. CEUS and CT were performed within a week of thrombus biopsies. For each imaging technique, diagnoses of thrombosis (present/absent) and thrombus nature (malignancy/benignancy) were made by experienced readers under blinded conditions and compared with pathological findings to determine accuracy rates for thrombus detection and characterization. Forty-four of the 50 thrombi were pathologically diagnosed as malignant and the remaining six were benign. CEUS detected 50/50 (100%) thrombi and correctly characterized 49/50 (98%). CT detected 34/50 (68%) thrombi and correctly characterized 23 of these 34 (68%). CEUS outperformed CT in terms of both thrombus detection (P < 0.0001) and characterization (P = 0.0001). CEUS appears to be significantly superior to CT for detection and characterization of portal vein thrombosis complicating HCC, and it should be considered in the staging of these tumors. (orig.)

  4. Detection and characterization of single nanoparticles by interferometric phase modulated ellipsometry

    Energy Technology Data Exchange (ETDEWEB)

    Barroso, F.; Bosch, S.; Tort, N.; Arteaga, O. [Universitat de Barcelona, IN2UB, Dep. Fisica Aplicada i Optica, c/Marti i Franques 1, 08028 (Spain); Sancho-Parramon, J. [Rudjer Boskovic Institute, Bijenicka c. 54, Zagreb 10002 (Croatia); Jover, E.; Bertran, E. [Universitat de Barcelona, IN2UB, Dep. Fisica Aplicada i Optica, c/Marti i Franques 1, 08028 (Spain); Canillas, A., E-mail: acanillas@ub.ed [Universitat de Barcelona, IN2UB, Dep. Fisica Aplicada i Optica, c/Marti i Franques 1, 08028 (Spain)

    2011-02-28

    We introduce a new measurement system called Nanopolar interferometer devoted to monitor and characterize single nanoparticles which is based on the interferometric phase modulated ellipsometry technique. The system collects the backscattered light by the particles in the solid angle subtended by a microscope objective and then analyses its frequency components. The results for the detection of 2 {mu}m and 50 nm particles are explained in terms of a cross polarization effect of the polarization vectors when the beam converts from divergent to parallel in the microscope objective. This explanation is supported with the results of the optical modelling using the exact Mie theory for the light scattered by the particles.

  5. Characterization of a direct detection device imaging camera for transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Milazzo, Anna-Clare, E-mail: amilazzo@ncmir.ucsd.edu [University of California at San Diego, 9500 Gilman Dr., La Jolla, CA 92093 (United States); Moldovan, Grigore [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Lanman, Jason [Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037 (United States); Jin, Liang; Bouwer, James C. [University of California at San Diego, 9500 Gilman Dr., La Jolla, CA 92093 (United States); Klienfelder, Stuart [University of California at Irvine, Irvine, CA 92697 (United States); Peltier, Steven T.; Ellisman, Mark H. [University of California at San Diego, 9500 Gilman Dr., La Jolla, CA 92093 (United States); Kirkland, Angus I. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Xuong, Nguyen-Huu [University of California at San Diego, 9500 Gilman Dr., La Jolla, CA 92093 (United States)

    2010-06-15

    The complete characterization of a novel direct detection device (DDD) camera for transmission electron microscopy is reported, for the first time at primary electron energies of 120 and 200 keV. Unlike a standard charge coupled device (CCD) camera, this device does not require a scintillator. The DDD transfers signal up to 65 lines/mm providing the basis for a high-performance platform for a new generation of wide field-of-view high-resolution cameras. An image of a thin section of virus particles is presented to illustrate the substantially improved performance of this sensor over current indirectly coupled CCD cameras.

  6. Characterization of a direct detection device imaging camera for transmission electron microscopy

    International Nuclear Information System (INIS)

    Milazzo, Anna-Clare; Moldovan, Grigore; Lanman, Jason; Jin, Liang; Bouwer, James C.; Klienfelder, Stuart; Peltier, Steven T.; Ellisman, Mark H.; Kirkland, Angus I.; Xuong, Nguyen-Huu

    2010-01-01

    The complete characterization of a novel direct detection device (DDD) camera for transmission electron microscopy is reported, for the first time at primary electron energies of 120 and 200 keV. Unlike a standard charge coupled device (CCD) camera, this device does not require a scintillator. The DDD transfers signal up to 65 lines/mm providing the basis for a high-performance platform for a new generation of wide field-of-view high-resolution cameras. An image of a thin section of virus particles is presented to illustrate the substantially improved performance of this sensor over current indirectly coupled CCD cameras.

  7. Methods for detection and characterization of signals in noisy data with the Hilbert-Huang transform

    International Nuclear Information System (INIS)

    Stroeer, Alexander; Cannizzo, John K.; Camp, Jordan B.; Gagarin, Nicolas

    2009-01-01

    The Hilbert-Huang transform is a novel, adaptive approach to time series analysis that does not make assumptions about the data form. Its adaptive, local character allows the decomposition of nonstationary signals with high time-frequency resolution but also renders it susceptible to degradation from noise. We show that complementing the Hilbert-Huang transform with techniques such as zero-phase filtering, kernel density estimation and Fourier analysis allows it to be used effectively to detect and characterize signals with low signal-to-noise ratios.

  8. High-speed crystal detection and characterization using a fast-readout detector.

    Science.gov (United States)

    Aishima, Jun; Owen, Robin L; Axford, Danny; Shepherd, Emma; Winter, Graeme; Levik, Karl; Gibbons, Paul; Ashton, Alun; Evans, Gwyndaf

    2010-09-01

    A novel raster-scanning method combining continuous sample translation with the fast readout of a Pilatus P6M detector has been developed on microfocus beamline I24 at Diamond Light Source. This fast grid-scan tool allows the rapid evaluation of large sample volumes without the need to increase the beam size at the sample through changes in beamline hardware. A slow version is available for slow-readout detectors. Examples of grid-scan use in centring optically invisible samples and in detecting and characterizing numerous microcrystals on a mesh-like holder illustrate the most common applications of the grid scan now in routine use on I24.

  9. Detection, isolation and characterization of principle synthetic route indicative impurity in telmisartan

    Directory of Open Access Journals (Sweden)

    V. Srinivasan

    2016-11-01

    Full Text Available An unknown impurity was detected in the telmisartan bulk drug (active pharmaceutical ingredient – API using an isocratic reversed-phase high performance liquid chromatography (HPLC. This impurity was isolated by preparative HPLC. Spectral data of the isolated impurity were collected. Based on the spectral data deriving from two dimensional nuclear magnetic spectroscopy (2D-NMR and mass spectrometry (MS, the impurity was characterized as “methyl 4′,4′-dibromo methyl biphenyl-2-carboxylate”. The arrived structure was further confirmed by theoretical studies.

  10. Detection and characterization of single nanoparticles by interferometric phase modulated ellipsometry

    International Nuclear Information System (INIS)

    Barroso, F.; Bosch, S.; Tort, N.; Arteaga, O.; Sancho-Parramon, J.; Jover, E.; Bertran, E.; Canillas, A.

    2011-01-01

    We introduce a new measurement system called Nanopolar interferometer devoted to monitor and characterize single nanoparticles which is based on the interferometric phase modulated ellipsometry technique. The system collects the backscattered light by the particles in the solid angle subtended by a microscope objective and then analyses its frequency components. The results for the detection of 2 μm and 50 nm particles are explained in terms of a cross polarization effect of the polarization vectors when the beam converts from divergent to parallel in the microscope objective. This explanation is supported with the results of the optical modelling using the exact Mie theory for the light scattered by the particles.

  11. Apparatus and method for detection and characterization of particles using light scattered therefrom

    Science.gov (United States)

    Johnston, R.G.

    1987-03-23

    Apparatus and method for detection and characterization of particles using light scattered therefrom. Differential phase measurements on scattered light from particles are possible using the two-frequency Zeeman effect laser which emits two frequencies of radiation 250 kHz apart. Excellent discrimination and reproducibility for various pure pollen and bacterial samples in suspension have been observed with a single polarization element. Additionally, a 250 kHz beat frequency was recorded from an individual particle traversing the focused output from the laser in a flow cytometer. 13 figs.

  12. Method of shaping of direction-characterization of sensitivity of ionizing radiation detection probe

    International Nuclear Information System (INIS)

    Czarnecki, J.; Jaszczuk, J.; Kruczyk, M.; Slapa, M.; Wroblewski, T.

    1986-01-01

    A method of shaping of direction-characterization of sensitivity of the ionizing radiation detection probe, especially equipped with small gamma detectors is described. Two detectors are placed coaxially in the bases of the cylindrical shield. One of them is uncovered in the highest degree and the second is not covered to a maximum. The signals from them are processed on the standarized sequences of electrical impulses (taking into account the heights and the widths of the amplitude). 2 figs., 1 tab. (A.S.)

  13. ASTEP: Towards the detection and characterization of exoplanets from Dome C

    Directory of Open Access Journals (Sweden)

    Rauer H.

    2011-02-01

    Full Text Available The ASTEP project (Antarctic Search for Transiting ExoPlanets, aims at testing the quality of the Dome C site in Antarctica for photometry in the visible, as well as detecting and characterizing transiting exoplanets. A dedicated telescope, ASTEP400, has been developped and installed at Concordia. The first campaign took place during the winter 2010, and the telescope functionned nominally during all the winter. A first analysis of the data leads to a precision of 189 and 205 ppm for WASP-19 and WASP-18 respectively, for continuous observations during 1 month. This shows that extremely high precision photometry is achievable from Dome C.

  14. Fabrication and characterization of spiral interdigitated electrodes based biosensor for salivary glucose detection

    Science.gov (United States)

    Adelyn, P. Y. P.; Hashim, U.; Arshad, M. K. Md; Voon, C. H.; Liu, Wei-Wen; Kahar, S. M.; Huda, A. R. N.; Lee, H. Cheun

    2017-03-01

    This work introduces the non-invasive glucose monitoring technique by using the Complementary Metal Oxide Semiconductor (CMOS) technologically fabricated spiral Interdigitated Electrodes (IDE) based biosensor. Scanning Electron Microscopy (SEM) image explores the morphology of spiral IDE while Energy Dispersive X-Ray (EDX) determines the elements induced in spiral IDE. Oral saliva of two patients are collected and tested on the spiral IDE sensor with electrical characterization as glucose detection results. However, both patients exhibit their glucose level characteristics inconsistently. Therefore, this work could be extended and enhanced by adding Glutaraldehyde in between 3-Aminoproply)triethoxysilane (APTES) modified and glucose oxidase (GOD) enzyme immobilized layer with FTIR validation for bonding attachment.

  15. Methods for radiation detection and characterization using a multiple detector probe

    Science.gov (United States)

    Akers, Douglas William; Roybal, Lyle Gene

    2014-11-04

    Apparatuses, methods, and systems relating to radiological characterization of environments are disclosed. Multi-detector probes with a plurality of detectors in a common housing may be used to substantially concurrently detect a plurality of different radiation activities and types. Multiple multi-detector probes may be used in a down-hole environment to substantially concurrently detect radioactive activity and contents of a buried waste container. Software may process, analyze, and integrate the data from the different multi-detector probes and the different detector types therein to provide source location and integrated analysis as to the source types and activity in the measured environment. Further, the integrated data may be used to compensate for differential density effects and the effects of radiation shielding materials within the volume being measured.

  16. [Single-molecule detection and characterization of DNA replication based on DNA origami].

    Science.gov (United States)

    Wang, Qi; Fan, Youjie; Li, Bin

    2014-08-01

    To investigate single-molecule detection and characterization of DNA replication. Single-stranded DNA (ssDNA) as the template of DNA replication was attached to DNA origami by a hybridization reaction based on the complementary base-pairing principle. DNA replication catalyzed by E.coli DNA polymerase I Klenow Fragment (KF) was detected using atomic force microscopy (AFM). The height variations between the ssDNA and the double-stranded DNA (dsDNA), the distribution of KF during DNA replication and biotin-streptavidin (BA) complexes on the DNA strand after replication were detected. Agarose gel electrophoresis was employed to analyze the changes in the DNA after replication. The designed ssDNA could be anchored on the target positions of over 50% of the DNA origami. The KF was capable of binding to the ssDNA fixed on DNA origami and performing its catalytic activities, and was finally dissociated from the DNA after replication. The height of DNA strand increased by about 0.7 nm after replication. The addition of streptavidin also resulted in an DNA height increase to about 4.9 nm due to the formation of BA complexes on the biotinylated dsDNA. The resulting dsDNA and BA complex were subsequently confirmed by agarose gel electrophoresis. The combination of AFM and DNA origami allows detection and characterization of DNA replication at the single molecule level, and this approach provides better insights into the mechanism of DNA polymerase and the factors affecting DNA replication.

  17. The "Sigmoid Sniffer” and the "Advanced Automated Solar Filament Detection and Characterization Code” Modules

    Science.gov (United States)

    Raouafi, Noureddine; Bernasconi, P. N.; Georgoulis, M. K.

    2010-05-01

    We present two pattern recognition algorithms, the "Sigmoid Sniffer” and the "Advanced Automated Solar Filament Detection and Characterization Code,” that are among the Feature Finding modules of the Solar Dynamic Observatory: 1) Coronal sigmoids visible in X-rays and the EUV are the result of highly twisted magnetic fields. They can occur anywhere on the solar disk and are closely related to solar eruptive activity (e.g., flares, CMEs). Their appearance is typically synonym of imminent solar eruptions, so they can serve as a tool to forecast solar activity. Automatic X-ray sigmoid identification offers an unbiased way of detecting short-to-mid term CME precursors. The "Sigmoid Sniffer” module is capable of automatically detecting sigmoids in full-disk X-ray images and determining their chirality, as well as other characteristics. It uses multiple thresholds to identify persistent bright structures on a full-disk X-ray image of the Sun. We plan to apply the code to X-ray images from Hinode/XRT, as well as on SDO/AIA images. When implemented in a near real-time environment, the Sigmoid Sniffer could allow 3-7 day forecasts of CMEs and their potential to cause major geomagnetic storms. 2)The "Advanced Automated Solar Filament Detection and Characterization Code” aims to identify, classify, and track solar filaments in full-disk Hα images. The code can reliably identify filaments; determine their chirality and other relevant parameters like filament area, length, and average orientation with respect to the equator. It is also capable of tracking the day-by-day evolution of filaments as they traverse the visible disk. The code was tested by analyzing daily Hα images taken at the Big Bear Solar Observatory from mid-2000 to early-2005. It identified and established the chirality of thousands of filaments without human intervention.

  18. Molecular Detection and Characterization of Tick-borne Pathogens in Dogs and Ticks from Nigeria

    Science.gov (United States)

    Kamani, Joshua; Baneth, Gad; Mumcuoglu, Kosta Y.; Waziri, Ndadilnasiya E.; Eyal, Osnat; Guthmann, Yifat; Harrus, Shimon

    2013-01-01

    Background Only limited information is currently available on the prevalence of vector borne and zoonotic pathogens in dogs and ticks in Nigeria. The aim of this study was to use molecular techniques to detect and characterize vector borne pathogens in dogs and ticks from Nigeria. Methodology/Principal Findings Blood samples and ticks (Rhipicephalus sanguineus, Rhipicephalus turanicus and Heamaphysalis leachi) collected from 181 dogs from Nigeria were molecularly screened for human and animal vector-borne pathogens by PCR and sequencing. DNA of Hepatozoon canis (41.4%), Ehrlichia canis (12.7%), Rickettsia spp. (8.8%), Babesia rossi (6.6%), Anaplasma platys (6.6%), Babesia vogeli (0.6%) and Theileria sp. (0.6%) was detected in the blood samples. DNA of E. canis (23.7%), H. canis (21.1%), Rickettsia spp. (10.5%), Candidatus Neoehrlichia mikurensis (5.3%) and A. platys (1.9%) was detected in 258 ticks collected from 42 of the 181 dogs. Co- infections with two pathogens were present in 37% of the dogs examined and one dog was co-infected with 3 pathogens. DNA of Rickettsia conorii israelensis was detected in one dog and Rhipicephalus sanguineus tick. DNA of another human pathogen, Candidatus N. mikurensis was detected in Rhipicephalus sanguineus and Heamaphysalis leachi ticks, and is the first description of Candidatus N. mikurensis in Africa. The Theileria sp. DNA detected in a local dog in this study had 98% sequence identity to Theileria ovis from sheep. Conclusions/Significance The results of this study indicate that human and animal pathogens are abundant in dogs and their ticks in Nigeria and portray the potential high risk of human exposure to infection with these agents. PMID:23505591

  19. Molecular detection and characterization of tick-borne pathogens in dogs and ticks from Nigeria.

    Directory of Open Access Journals (Sweden)

    Joshua Kamani

    Full Text Available BACKGROUND: Only limited information is currently available on the prevalence of vector borne and zoonotic pathogens in dogs and ticks in Nigeria. The aim of this study was to use molecular techniques to detect and characterize vector borne pathogens in dogs and ticks from Nigeria. METHODOLOGY/PRINCIPAL FINDINGS: Blood samples and ticks (Rhipicephalus sanguineus, Rhipicephalus turanicus and Heamaphysalis leachi collected from 181 dogs from Nigeria were molecularly screened for human and animal vector-borne pathogens by PCR and sequencing. DNA of Hepatozoon canis (41.4%, Ehrlichia canis (12.7%, Rickettsia spp. (8.8%, Babesia rossi (6.6%, Anaplasma platys (6.6%, Babesia vogeli (0.6% and Theileria sp. (0.6% was detected in the blood samples. DNA of E. canis (23.7%, H. canis (21.1%, Rickettsia spp. (10.5%, Candidatus Neoehrlichia mikurensis (5.3% and A. platys (1.9% was detected in 258 ticks collected from 42 of the 181 dogs. Co- infections with two pathogens were present in 37% of the dogs examined and one dog was co-infected with 3 pathogens. DNA of Rickettsia conorii israelensis was detected in one dog and Rhipicephalus sanguineus tick. DNA of another human pathogen, Candidatus N. mikurensis was detected in Rhipicephalus sanguineus and Heamaphysalis leachi ticks, and is the first description of Candidatus N. mikurensis in Africa. The Theileria sp. DNA detected in a local dog in this study had 98% sequence identity to Theileria ovis from sheep. CONCLUSIONS/SIGNIFICANCE: The results of this study indicate that human and animal pathogens are abundant in dogs and their ticks in Nigeria and portray the potential high risk of human exposure to infection with these agents.

  20. A hybrid positron and OCT intraoperative probe for ovarian cancer detection and characterization

    Science.gov (United States)

    Yang, Yi; Biswal, Nrusingh C.; Wang, Tianheng; Kumavor, Patrick; Karimeddini, Mozafareddin; Sanders, Melinda; Brewer, Molly; Zhu, Quing

    2011-03-01

    Ovarian cancer has the lowest survival rate of the gynecologic cancers with a 5-year survival of about 50% in the United States. With current screening and diagnostic abilities for ovarian cancers, most of the diagnosed patients are already with advanced stages and the majority of them will die of this deadly disease. In this paper, we report a multimodal imaging approach which combines optical coherence tomography (OCT) and positron detection for early ovarian cancer detection. The dual modality system has the capability of providing both functional and morphological images simultaneously. While the positron detection provides the metabolism activity of the ovary due to the uptake of radiotracer, the OCT provides the high resolution (25μm X 25μm X 12μm - longitudinal X lateral X axial in air) structural imaging at 20k A-lines per second. Total 18 ovaries obtained from 10 patients classified as normal, abnormal and malignant ovarian tissues were characterized ex vivo. Positron counts of 1.2-fold higher was found between abnormal and normal ovaries and 3~30-fold higher was found between malignant and normal ovaries. OCT imaging of malignant and abnormal ovaries revealed many detailed morphologic features that could be potentially valuable for detecting early malignant changes in the ovary.

  1. [Micro-droplet characterization and its application for amino acid detection in droplet microfluidic system].

    Science.gov (United States)

    Yuan, Huiling; Dong, Libing; Tu, Ran; Du, Wenbin; Ji, Shiru; Wang, Qinhong

    2014-01-01

    Recently, the droplet microfluidic system attracts interests due to its high throughput and low cost to detect and screen. The picoliter micro-droplets from droplet microfluidics are uniform with respect to the size and shape, and could be used as monodispensed micro-reactors for encapsulation and detection of single cell or its metabolites. Therefore, it is indispensable to characterize micro-droplet and its application from droplet microfluidic system. We first constructed the custom-designed droplet microfluidic system for generating micro-droplets, and then used the micro-droplets to encapsulate important amino acids such as glutamic acid, phenylalanine, tryptophan or tyrosine to test the droplets' properties, including the stability, diffusivity and bio-compatibility for investigating its application for amino acid detection and sorting. The custom-designed droplet microfluidic system could generate the uniformed micro-droplets with a controllable size between 20 to 50 microm. The micro-droplets could be stable for more than 20 h without cross-contamination or fusion each other. The throughput of detection and sorting of the system is about 600 micro-droplets per minute. This study provides a high-throughput platform for the analysis and screening of amino acid-producing microorganisms.

  2. The Impact of Forest Density on Forest Height Inversion Modeling from Polarimetric InSAR Data

    Directory of Open Access Journals (Sweden)

    Changcheng Wang

    2016-03-01

    Full Text Available Forest height is of great significance in analyzing the carbon cycle on a global or a local scale and in reconstructing the accurate forest underlying terrain. Major algorithms for estimating forest height, such as the three-stage inversion process, are depending on the random-volume-over-ground (RVoG model. However, the RVoG model is characterized by a lot of parameters, which influence its applicability in forest height retrieval. Forest density, as an important biophysical parameter, is one of those main influencing factors. However, its influence to the RVoG model has been ignored in relating researches. For this paper, we study the applicability of the RVoG model in forest height retrieval with different forest densities, using the simulated and real Polarimetric Interferometric SAR data. P-band ESAR datasets of the European Space Agency (ESA BioSAR 2008 campaign were selected for experiments. The test site was located in Krycklan River catchment in Northern Sweden. The experimental results show that the forest density clearly affects the inversion accuracy of forest height and ground phase. For the four selected forest stands, with the density increasing from 633 to 1827 stems/Ha, the RMSEs of inversion decrease from 4.6 m to 3.1 m. The RVoG model is not quite applicable for forest height retrieval especially in sparsely vegetated areas. We conclude that the forest stand density is positively related to the estimation accuracy of the ground phase, but negatively correlates to the ground-to-volume scattering ratio.

  3. Preparation, Characterization, and UV Irradiation of Mars Soil Analogues Under Simulated Martian Conditions to Support Detection of Molecular Biomarkers

    Science.gov (United States)

    Fornaro, T.; Brucato, J. R.; ten Kate, I. L.; Siljeström, S.; Steele, A.; Cody, G. D.; Hazen, R. M.

    2018-04-01

    We present laboratory activities of preparation, characterization, and UV irradiation processing of Mars soil analogues, which are key to support both in situ exploration and sample return missions devoted to detection of molecular biomarkers on Mars.

  4. Fiber-based polarimetric stress sensor for measuring the Young's modulus of biomaterials

    Science.gov (United States)

    Harrison, Mark C.; Armani, Andrea M.

    2015-03-01

    Polarimetric optical fiber-based stress and pressure sensors have proven to be a robust tool for measuring and detecting changes in the Young's modulus (E) of materials in response to external stimuli, including the real-time monitoring of the structural integrity of bridges and buildings. These sensors typically work by using a pair of polarizers before and after the sensing region of the fiber, and often require precise alignment to achieve high sensitivity. The ability to perform similar measurements in natural and in engineered biomaterials could provide significant insights and enable research advancement and preventative healthcare. However, in order for this approach to be successful, it is necessary to reduce the complexity of the system by removing free-space components and the need for alignment. As the first step in this path, we have developed a new route for performing these measurements. By generalizing and expanding established theoretical analyses for these types of sensors, we have developed a predictive theoretical model. Additionally, by replacing the conventional free space components and polarization filters with a polarimeter, we have constructed a sensor system with higher sensitivity and which is semi-portable. In initial experiments, a series of polydimethylsiloxane (PDMS) samples with several base:curing agent ratios ranging from 5:1 up to 30:1 were prepared to simulate tissues with different stiffnesses. By simultaneously producing stress-strain curves using a load frame and monitoring the polarization change of light traveling through the samples, we verified the accuracy of our theoretical model.

  5. Laboratory polarization and permittivity measurements to interpret dust polarimetric observations and in-situ radar studies. Significance for Rosetta mission at 67P/Churyumov-Gerasimenko

    Science.gov (United States)

    Levasseur-Regourd, Anny-Chantal; Brouet, Yann; Hadamcik, Edith; Heggy, Essam; Hines, Dean; Lasue, Jérémie; Renard, Jean-Baptiste

    2015-08-01

    Polarimetric astronomical observations on dust clouds and regolithic surfaces require laboratory simulations on samples to provide information on properties (size distribution, porosity, refractive index) of the scattering media. Similarly, in-situ radar investigations in the solar system require laboratory studies on samples to infer physical properties (e.g. porosity, ice/dust ratio) of sub-surfaces and interiors. Recent developments are illustrated with present studies related to the Rosetta mission, which begun its rendezvous with comet 67P/Churyumov-Gerasimeko (C-G) and landed the Philae module on its nucleus in 2014.We will summarize laboratory simulations with the PROGRA2 suite of instruments that study (in the visible to near IR domain) the polarimetric properties of dust samples in microgravity conditions or on surfaces [1], with emphasis on the interpretation of polarimetric observations of C-G, during its previous perihelion passages from Earth observatories, and currently from HST [2,3]. The presence of large dust particles in the pre-perihelion coma previously inferred from remote observations agrees with Rosetta ground truth [4]. We will also present measurements on the permittivity (in the millimeter to meter domain) of various dust samples, with emphasis on porous samples [5,6]. Results provide constraints on the properties of the subsurface and interior of C-G, as explored by MIRO on Rosetta and CONSERT on Philae.Such studies are relevant for the interpretation of polarimetric observations of other dust clouds (e.g. debris disks, interplanetary dust cloud, clouds in planetary atmospheres) and surfaces (e.g. planets, moons), as well as for those of other radar characterization studies (e.g. Mars, moons, asteroids).[1] Levasseur-Regourd et al. In Polarization of stars and planetary systems, Cambridge UP, in press 2015.[2] Hadamcik et al. A&A 517 2010.[3] Hines and Levasseur-Regourd, PSS submitted 2015.[4] Schulz et al. Nature 518 2015.[5] Heggy et al

  6. NMR detection and characterization of sialylated glycoproteins and cell surface polysaccharides

    International Nuclear Information System (INIS)

    Barb, Adam W.; Freedberg, Darón I.; Battistel, Marcos D.; Prestegard, James H.

    2011-01-01

    Few solution NMR pulse sequences exist that are explicitly designed to characterize carbohydrates (glycans). This is despite the essential role carbohydrate motifs play in cell–cell communication, microbial pathogenesis, autoimmune disease progression and cancer metastasis, and despite that fact that glycans, often shed to extra-cellular fluids, can be diagnostic of disease. Here we present a suite of two dimensional coherence experiments to measure three different correlations (H3–C2, H3–C1, and C1–C2) on sialic acids, a group of nine-carbon carbohydrates found on eukaryotic cell surfaces that often play a key role in disease processes. The chemical shifts of the H3, C2, and C1 nuclei of sialic acids are sensitive to carbohydrate linkage, linkage conformation, and ionization state of the C1 carboxylate. The experiments reported include rigorous filter elements to enable detection and characterization of isotopically labeled sialic acids with high sensitivity in living cells and crude isolates with minimal interference from unwanted signals arising from the ∼1% 13 C-natural abundance of cellular metabolites. Application is illustrated with detection of sialic acids on living cells, in unpurified mixtures, and at the terminus of the N-glycan on the 55 kDa immunoglobulin G Fc.

  7. Detection and characterization of intracranial aneurysms: magnetic resonance angiography versus digital subtraction angiography

    International Nuclear Information System (INIS)

    Shahzad, R.; Younas, F.

    2011-01-01

    Objective: To compare magnetic resonance angiography (MRA) with Intra-arterial digital subtraction angiography (IA-DSA) in detection and characterization of intracranial aneurysms. Study Design: Comparative cross-sectional study. Place and Duration of Study: Department of Diagnostic Imaging, Lahore General Hospital, Lahore, from January to June 2007. Methodology: Thirty patients presented with aneurysmal subarachnoid haemorrhage (SAH) and focal neurological signs were selected by convenience sampling. Three dimensional time of flight (3D TOF) MRA using maximum intensity projection (MIP) was performed on all patients along with DSA. Results of 3D TOF MRA were compared with those of IA-DSA taking IA-DSA as Gold standard. Results: Out of 30 patients 14 (46.7%) were males and 16 (53.3%) were females with mean age of 41+-14.1 years. MRA detected 29 out of 30 aneurysmal lesions with sensitivity of 96.7%. Regarding characterization of aneurysms results of MRA were comparable to those of IA-DSA. Conclusion: 3D TOF MRA technique showed a high sensitivity in this study. This technique can be used as a non-invasive screening test for intracranial aneurysms and as a suitable alternative primary examination to IA-DSA prior to aneurysmal surgery. (author)

  8. Detection and Characterization of Histamine-Producing Strains of Photobacterium damselae subsp. damselae Isolated from Mullets

    Directory of Open Access Journals (Sweden)

    Marcello Trevisani

    2017-06-01

    Full Text Available Photobacterium damselae subsp. damselae (Pdd is considered to be an emerging pathogen of marine fish and has also been implicated in cases of histamine food poisoning. In this study, eight strains isolated from mullets of the genera Mugil and Liza captured in the Ligurian Sea were characterized, and a method to detect histamine-producing Pdd from fish samples was developed. The histamine-producing potential of the strains was evaluated in culture media (TSB+ using a histamine biosensor. Subsequently, two strains were used to contaminate mackerel fillets (4 or 40 CFU/g, simulating a cross-contamination on the selling fish stalls. Sample homogenates were enriched in TSB+. The cultures were then inoculated on thiosulfate-citrate-bile salts-sucrose agar (TCBS and the dark green colonies were cultured on Niven agar. The violet isolates were characterized using specific biochemical and PCR based tests. All Pdd strains were histamine producers, yielding concentration varying from 167 and 8977 µg/mL in TSB+ cultures incubated at 30 °C for 24 h. Pdd colonies were detected from the inoculated mackerel samples and their histidine decarboxylase gene was amplified using species-specific primer pairs designed for this study. The results indicate that mullets can be source of Pdd and the fish retailers needs to evaluate the risk posed by cross-contamination on the selling fish stalls.

  9. Monitoring of Oil Exploitation Infrastructure by Combining Unsupervised Pixel-Based Classification of Polarimetric SAR and Object-Based Image Analysis

    Directory of Open Access Journals (Sweden)

    Simon Plank

    2014-12-01

    Full Text Available In developing countries, there is a high correlation between the dependence of oil exports and violent conflicts. Furthermore, even in countries which experienced a peaceful development of their oil industry, land use and environmental issues occur. Therefore, independent monitoring of oil field infrastructure may support problem solving. Earth observation data enables fast monitoring of large areas which allows comparing the real amount of land used by the oil exploitation and the companies’ contractual obligations. The target feature of this monitoring is the infrastructure of the oil exploitation, oil well pads—rectangular features of bare land covering an area of approximately 50–60 m × 100 m. This article presents an automated feature extraction procedure based on the combination of a pixel-based unsupervised classification of polarimetric synthetic aperture radar data (PolSAR and an object-based post-classification. The method is developed and tested using dual-polarimetric TerraSAR-X imagery acquired over the Doba basin in south Chad. The advantages of PolSAR are independence of the cloud coverage (vs. optical imagery and the possibility of detailed land use classification (vs. single-pol SAR. The PolSAR classification uses the polarimetric Wishart probability density function based on the anisotropy/entropy/alpha decomposition. The object-based post-classification refinement, based on properties of the feature targets such as shape and area, increases the user’s accuracy of the methodology by an order of a magnitude. The final achieved user’s and producer’s accuracy is 59%–71% in each case (area based accuracy assessment. Considering only the numbers of correctly/falsely detected oil well pads, the user’s and producer’s accuracies increase to even 74%–89%. In an iterative training procedure the best suited polarimetric speckle filter and processing parameters of the developed feature extraction procedure are

  10. Sensitivity of C-Band Polarimetric Radar-Based Drop Size Distribution Measurements to Maximum Diameter Assumptions

    Science.gov (United States)

    Carey, Lawrence D.; Petersen, Walter A.

    2011-01-01

    Mission (GPM/PMM Science Team)-funded study is to document the sensitivity of DSD measurements, including estimates of D0, from C-band Z(sub dr) and reflectivity to this range of D(sub max) assumptions. For this study, GPM Ground Validation 2DVD's were operated under the scanning domain of the UAHuntsville ARMOR C-band dual-polarimetric radar. Approximately 7500 minutes of DSD data were collected and processed to create gamma size distribution parameters using a truncated method of moments approach. After creating the gamma parameter datasets the DSD's were then used as input to a T-matrix model for computation of polarimetric radar moments at C-band. All necessary model parameterizations, such as temperature, drop shape, and drop fall mode, were fixed at typically accepted values while the D(sub max) assumption was allowed to vary in sensitivity tests. By hypothesizing a DSD model with D(sub max) (fit) from which the empirical fit to D0 = F[Z(sub dr)] was derived via non-linear least squares regression and a separate reference DSD model with D(sub max) (truth), bias and standard error in D0 retrievals were estimated in the presence of Z(sub dr) measurement error and hypothesized mismatch in D(sub max) assumptions. Although the normalized standard error for D0 = F[Z(sub dr)r] can increase slightly (as much as from 11% to 16% for all 7500 DSDs) when the D(sub max) (fit) does not match D(sub max) (truth), the primary impact of uncertainty in D(sub max) is a potential increase in normalized bias error in D0 (from 0% to as much as 10% over all 7500 DSDs, depending on the extent of the mismatch between D(sub max) (fit) and D(sub max) (truth)). For DSDs characterized by large Z(sub dr) (Z(sub dr) > 1.5 to 2.0 dB), the normalized bias error for D0 estimation at C-band is sometimes unacceptably large (> 10%), again depending on the extent of the hypothesized D(sub max) mismatch. Modeled errors in D0 retrievals from Z(sub dr) at C-band are demonstrated in detail and comparedo

  11. The cryogenic photon detection system for the ALPS II experiment. Characterization, optimization and background rejection

    International Nuclear Information System (INIS)

    Bastidon, Noemi Alice Chloe

    2017-01-01

    The search for new fundamental bosons at very low mass is the central objective of the ALPS II experiment which is currently set up at the Deutsches Elektronen-Synchrotron (DESY, Hamburg). This experiment follows the light-shining-through-the-wall concept where photons could oscillate into weakly interacting light bosons in front of a wall and back into photons behind the wall, giving the impression that light can shine through a light tight barrier. In this concept, the background-free detection of near-infrared photons is required to fully exploit the sensitivity of the apparatus. The high efficiency single-photon detection in the near-infrared is challenging and requires a cryogenic detector. In this project, a Transition-Edge Sensor (TES) operated below 100mK will be used to detect single photons. This thesis focuses on the characterization and optimization of the ALPS II detector system including an Adiabatic Demagnetisation Refrigerator (ADR) with its two-stage pulse-tube cooler, two TES detectors and their Superconducting Quantum Interference Devices (SQUIDs) read-out system. Stability of the detection system over time is a priority in the ALPS II experiment. It is in this context that the cooling system has been subjected to many upgrades. In the framework of this thesis, the cooling setup has been studied in detail in order to optimize its cooling performances. Furthermore, the stability of the detector has been studied according to various criteria. Other essential parameters of the ALPS II experiment are its detection efficiency and its background rate. Indeed, the sensitivity of the experiment directly depends on these two characteristics. Both elements have been studied in depth in order to define if the chosen TES detector will meet ALPS IIc specifications.

  12. Detection and characterization of flaws in segments of light water reactor pressure vessels

    International Nuclear Information System (INIS)

    Cook, K.V.; Cunningham, R.A. Jr.; McClung, R.W.

    1988-01-01

    Studies have been conducted to determine flaw density in segments cut from light water reactor )LWR) pressure vessels as part of the Oak Ridge National Laboratory's Heavy-Section Steel Technology (H SST) Program. Segments from the Hope Creek Unit 2 vessel and the Pilgrim Unit 2 Vessel were purchased from salvage dealers. Hope Creek was a boiling water reactor (BWR) design and Pilgrim was a pressurized water reactor (PWR) design. Neither were ever placed in service. Objectives were to evaluate these LWR segments for flaws with ultrasonic and liquid penetrant techniques. Both objectives were successfully completed. One significant indication was detected in a Hope Creek seam weld by ultrasonic techniques and characterized by further analyses terminating with destructive correlation. This indication [with a through-wall dimension of ∼6 mm (∼0.24 in.)] was detected in only 3 m (10 ft) of weldment and offers extremely limited data when compared to the extent of welding even in a single pressure vessel. However, the detection and confirmation of the flaw in the arbitrarily selected sections implies the Marshall report estimates (and others) are nonconservative for such small flaws. No significant indications were detected in the Pilgrim material by ultrasonic techniques. Unfortunately, the Pilgrim segments contained relatively little weldment; thus, we limited our ultrasonic examinations to the cladding and subcladding regions. Fluorescent liquid penetrant inspection of the cladding surfaces for both LWR segments detected no significant indications [i.e., for a total of approximately 6.8 m 2 (72 ft 2 ) of cladding surface]. (author)

  13. The cryogenic photon detection system for the ALPS II experiment. Characterization, optimization and background rejection

    Energy Technology Data Exchange (ETDEWEB)

    Bastidon, Noemi Alice Chloe

    2017-01-12

    The search for new fundamental bosons at very low mass is the central objective of the ALPS II experiment which is currently set up at the Deutsches Elektronen-Synchrotron (DESY, Hamburg). This experiment follows the light-shining-through-the-wall concept where photons could oscillate into weakly interacting light bosons in front of a wall and back into photons behind the wall, giving the impression that light can shine through a light tight barrier. In this concept, the background-free detection of near-infrared photons is required to fully exploit the sensitivity of the apparatus. The high efficiency single-photon detection in the near-infrared is challenging and requires a cryogenic detector. In this project, a Transition-Edge Sensor (TES) operated below 100mK will be used to detect single photons. This thesis focuses on the characterization and optimization of the ALPS II detector system including an Adiabatic Demagnetisation Refrigerator (ADR) with its two-stage pulse-tube cooler, two TES detectors and their Superconducting Quantum Interference Devices (SQUIDs) read-out system. Stability of the detection system over time is a priority in the ALPS II experiment. It is in this context that the cooling system has been subjected to many upgrades. In the framework of this thesis, the cooling setup has been studied in detail in order to optimize its cooling performances. Furthermore, the stability of the detector has been studied according to various criteria. Other essential parameters of the ALPS II experiment are its detection efficiency and its background rate. Indeed, the sensitivity of the experiment directly depends on these two characteristics. Both elements have been studied in depth in order to define if the chosen TES detector will meet ALPS IIc specifications.

  14. Detection, characterization and measure of a new radiation-induced damage in isolated and cellular DNA

    International Nuclear Information System (INIS)

    Regulus, P.

    2006-10-01

    Deoxyribonucleic acid (DNA) contains the genetic information and chemical injury to this macromolecule may have severe biological consequences. We report here the detection of 4 new radiation-induced DNA lesions by using a high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) approach. For that purpose, the characteristic fragmentation of most 2'-deoxy-ribo nucleosides, the loss of 116 Da corresponding to the loss of the 2-deoxyribose moiety, was used in the so-called neutral loss mode of the HPLC-MS/MS. One of the newly detected lesions, named dCyd341 because it is a 2'-deoxycytidine modification exhibiting a molecular weight of 341 Da, was also detected in cellular DNA. Characterization of this modified nucleoside was performed using NMR and exact mass determination of the product obtained by chemical synthesis. A mechanism of formation was then proposed, in which the first event is the H-abstraction at the C4 position of a 2-deoxyribose moiety. Then, the sugar modification produced exhibits a reactive aldehyde that, through reaction with a vicinal cytosine base, gives rise to dCyd341. dCyd341 could be considered as a complex damage since its formation involves a DNA strand break and a cross-link between a damaged sugar residue and a vicinal cytosine base located most probably on the complementary DNA strand. In addition to its characterization, preliminary biological studies revealed that cells are able to remove the lesion from DNA. Repair studies have revealed the ability of cells to excise the lesion. Identification of the repair systems involved could represent an interesting challenge. (author)

  15. Discrimination of Oil Slicks and Lookalikes in Polarimetric SAR Images Using CNN.

    Science.gov (United States)

    Guo, Hao; Wu, Danni; An, Jubai

    2017-08-09

    Oil slicks and lookalikes (e.g., plant oil and oil emulsion) all appear as dark areas in polarimetric Synthetic Aperture Radar (SAR) images and are highly heterogeneous, so it is very difficult to use a single feature that can allow classification of dark objects in polarimetric SAR images as oil slicks or lookalikes. We established multi-feature fusion to support the discrimination of oil slicks and lookalikes. In the paper, simple discrimination analysis is used to rationalize a preferred features subset. The features analyzed include entropy, alpha, and Single-bounce Eigenvalue Relative Difference (SERD) in the C-band polarimetric mode. We also propose a novel SAR image discrimination method for oil slicks and lookalikes based on Convolutional Neural Network (CNN). The regions of interest are selected as the training and testing samples for CNN on the three kinds of polarimetric feature images. The proposed method is applied to a training data set of 5400 samples, including 1800 crude oil, 1800 plant oil, and 1800 oil emulsion samples. In the end, the effectiveness of the method is demonstrated through the analysis of some experimental results. The classification accuracy obtained using 900 samples of test data is 91.33%. It is here observed that the proposed method not only can accurately identify the dark spots on SAR images but also verify the ability of the proposed algorithm to classify unstructured features.

  16. An analytical model for the description of the full-polarimetric sea surface Doppler signature

    NARCIS (Netherlands)

    Fois, F.; Hoogeboom, P.; Le Chevalier, F.; Stoffelen, A.

    2015-01-01

    This paper describes an analytical model of the full-polarimetric sea surface scattering and Doppler signature. The model combines the small-slope-approximation theory (at the second order) with a weak nonlinear sea surface representation. Such a model is used to examine the variation of the Doppler

  17. Airborn Ku-band polarimetric radar remote sensing of terrestrial snow cover

    Science.gov (United States)

    Simon H. Yueh; Steve J. Dinardo; Ahmed Akgiray; Richard West; Donald W. Cline; Kelly Elder

    2009-01-01

    Characteristics of the Ku-band polarimetric scatterometer (POLSCAT) data acquired from five sets of aircraft flights in the winter months of 2006-2008 for the second Cold Land Processes Experiment (CLPX-II) in Colorado are described in this paper. The data showed the response of the Ku-band radar echoes to snowpack changes for various types of background vegetation in...

  18. Determination of the full polarimetric transition matrix of a magnetized plasma from measurements of phase only

    International Nuclear Information System (INIS)

    Segre, S.E.

    1996-09-01

    It is shown that, by using a convenient modulated input polarization, it is possible to determine the full plasma polarimetric transition matrix purely from phase measurements. These are advantageous compared to previously proposed amplitude measurements. Two alternative sets of configurations for the input polarization are considered. The elements of the transition matrix thus found can be used in the reconstruction of the MHD equilibrium

  19. Unsupervised Full-Polarimetric SAR Data Segmentation as a Tool for Classification of Agricultural Areas

    NARCIS (Netherlands)

    Hoekman, D.H.; Vissers, M.A.M.; Tran, T.N.

    2011-01-01

    Versatile, robust and computational efficient methods for radar image segmentation, which preserve the full polarimetric information content, are of importance as research tools, as well as for practical applications in land surface monitoring. The method introduced here consists of several steps.

  20. Characterization of the internal background for thermal and fast neutron detection with CLLB

    Energy Technology Data Exchange (ETDEWEB)

    Woolf, Richard S., E-mail: richard.woolf@nrl.navy.mil; Phlips, Bernard F.; Wulf, Eric A.

    2016-12-01

    We report on a set of experiments conducted to determine what effects, if any, the internal background in the CLLB scintillation detector has on the thermal neutron detection performance. We conducted source measurements using an unmoderated and moderated {sup 252}Cf neutron/γ-ray source and long (48-h), unshielded and shielded, background measurements to characterize the internal background with and without a source present. These measurements allowed us to determine the 2-d event selections needed to isolate the thermal neutron peak observed in pulse shape vs. energy space and apply those selections to our background measurements. Our results indicate that the thermal neutron detection capabilities of the CLLB are marginally affected by the presence of internal background. An unmoderated 113-µCi {sup 252}Cf source at 15 cm from the detector yields a thermal neutron rate of 8×10{sup −2}/s cm{sup 3}, while moderating the source with 5 cm of polyethylene yields a thermal neutron rate of 5.5×10{sup −1}/s cm{sup 3}. The measured background rate for events that fall within the selected thermal neutron region is 1.2×10{sup −3}/s cm{sup 3}. Lastly, the potential for CLLB for detecting fast neutrons was investigated.

  1. Defect occurrence, detection, location and characterization; essential variables of the LBB concept application to primary piping

    Energy Technology Data Exchange (ETDEWEB)

    Crutzen, S.; Koble, T.D.; Lemaitre, P. [and others

    1997-04-01

    Applications of the Leak Before Break (LBB) concept involve the knowledge of flaw presence and characteristics. In Service Inspection is given the responsibility of detecting flaws of a determined importance to locate them precisely and to classify them in broad families. Often LBB concepts application imply the knowledge of flaw characteristics such as through wall depth; length at the inner diameter (ID) or outer diameter (OD) surface; orientation or tilt and skew angles; branching; surface roughness; opening or width; crack tip aspect. Besides detection and characterization, LBB evaluations consider important the fact that a crack could be in the weld material or in the base material or in the heat affected zone. Cracks in tee junctions, in homogenous simple welds and in elbows are not considered in the same way. Essential variables of a flaw or defect are illustrated, and examples of flaws found in primary piping as reported by plant operators or service vendors are given. If such flaw variables are important in the applications of LBB concepts, essential is then the knowledge of the performance achievable by NDE techniques, during an ISI, in detecting such flaws, in locating them and in correctly evaluating their characteristics.

  2. Construction and characterization of the detection modules for the Muon Portal Project

    Energy Technology Data Exchange (ETDEWEB)

    Blancato, A.A.; Bonanno, D.L.; La Rocca, P.; Longhitano, F.; Lo Presti, D.; Parasole, O.; Pugliatti, C.; Riggi, F.; Russo, G.V.; Santagati, G. [Dipartimento di Fisica e Astronomia, Universita di Catania and INFN, Catania, (Italy); Bandieramonte, M.; Billotta, S.; Bonanno, G.; Garozzo, S.; Marano, D.; Riggi, S.; Romeo, G. [INAF, Osservatorio Astrofisico di Catania, (Italy); Fallica, P.G.; Romeo, M. [STMicroelectronics, Catania, (Italy)

    2015-07-01

    The Muon Portal Project is a joint initiative between research and industrial partners, aimed at the construction of a real size detector prototype (6 x 3 x 7 m{sup 3}) for the inspection of containers by the muon scattering technique, devised to search for hidden high-Z fissile materials and provide a full 3D tomography of the interior of the container in a scanning time of the order of minutes. The muon tracking detector is based on a set of 48 detection modules (size 1 m x 3 m), each built with 100 extruded scintillator strips, so as to provide four X-Y detection planes, two placed above and two below the container to be inspected. Two wavelength shifting (WLS) fibres embedded in each strip convey the emitted photons to Silicon Photomultipliers (SiPM) which act as photo-sensors. After a research and development phase, which led to the choice and test of the individual components, the construction of the full size detector has already started. The paper describes the results of the mass characterization of the photo-sensors and the construction and test measurements of the first detection modules of the Project. (authors)

  3. Optical and non-optical methods for detection and characterization of microparticles and exosomes.

    Science.gov (United States)

    van der Pol, E; Hoekstra, A G; Sturk, A; Otto, C; van Leeuwen, T G; Nieuwland, R

    2010-12-01

    Microparticles and exosomes are cell-derived microvesicles present in body fluids that play a role in coagulation, inflammation, cellular homeostasis and survival, intercellular communication, and transport. Despite increasing scientific and clinical interest, no standard procedures are available for the isolation, detection and characterization of microparticles and exosomes, because their size is below the reach of conventional detection methods. Our objective is to give an overview of currently available and potentially applicable methods for optical and non-optical determination of the size, concentration, morphology, biochemical composition and cellular origin of microparticles and exosomes. The working principle of all methods is briefly discussed, as well as their applications and limitations based on the underlying physical parameters of the technique. For most methods, the expected size distribution for a given microvesicle population is determined. The explanations of the physical background and the outcomes of our calculations provide insights into the capabilities of each method and make a comparison possible between the discussed methods. In conclusion, several (combinations of) methods can detect clinically relevant properties of microparticles and exosomes. These methods should be further explored and validated by comparing measurement results so that accurate, reliable and fast solutions come within reach. © 2010 International Society on Thrombosis and Haemostasis.

  4. Short timescale photometric and polarimetric behavior of two BL Lacertae type objects

    International Nuclear Information System (INIS)

    Covino, S.; Baglio, M. C.; Foschini, L.; Sandrinelli, A.; Tavecchio, F.; Treves, A.; Zhang, H.; Barres de Almeida, U.; Bonnoli, G.; Boettcher, M.; Cecconi, M.; D'Ammando, F.; Fabrizio, L. di; Giarrusso, M.; Leone, F.; Lindfors, E.; Lorenzi, V.; Molinari, E.; Paiano, S.; Prandini, E.; Raiteri, C. M.; Stamerra, A.; Tagliaferri, G.

    2015-01-01

    Context. Blazars are astrophysical sources whose emission is dominated by non-thermal processes, typically interpreted as synchrotron and inverse Compton emission. Although the general picture is rather robust and consistent with observations, many aspects are still unexplored. Aims. Polarimetric monitoring can offer a wealth of information about the physical processes in blazars. Models with largely different physical ingredients can often provide almost indistinguishable predictions for the total flux, but usually are characterized by markedly different polarization properties. We explore, with a pilot study, the possibility to derive structural information about the emitting regions of blazars by means of a joint analysis of rapid variability of the total and polarized flux at optical wavelengths. Methods. Short timescale (from tens of seconds to a couple of minutes) optical linear polarimetry and photometry for two blazars, BL Lacertae and PKS 1424+240, was carried out with the PAOLO polarimeter at the 3.6 m Telescopio Nazionale Galileo. Several hours of almost continuous observations were obtained for both sources. Results. Our intense monitoring allowed us to draw strongly different scenarios for BL Lacertae and PKS 1424+240, with the former characterized by intense variability on time-scales from hours to a few minutes and the latter practically constant in total flux. Essentially the same behavior is observed for the polarized flux and the position angle. The variability time-scales turned out to be as short as a few minutes, although involving only a few percent variation of the flux. The polarization variability time-scale is generally consistent with the total flux variability. Total and polarized flux appear to be essentially uncorrelated. However, even during our relatively short monitoring, different regimes can be singled out. Conclusions. No simple scenario is able to satisfactorily model the very rich phenomenology exhibited in our data. As a

  5. Polarimetric SAR interferometry-based decomposition modelling for reliable scattering retrieval

    Science.gov (United States)

    Agrawal, Neeraj; Kumar, Shashi; Tolpekin, Valentyn

    2016-05-01

    Fully Polarimetric SAR (PolSAR) data is used for scattering information retrieval from single SAR resolution cell. Single SAR resolution cell may contain contribution from more than one scattering objects. Hence, single or dual polarized data does not provide all the possible scattering information. So, to overcome this problem fully Polarimetric data is used. It was observed in previous study that fully Polarimetric data of different dates provide different scattering values for same object and coefficient of determination obtained from linear regression between volume scattering and aboveground biomass (AGB) shows different values for the SAR dataset of different dates. Scattering values are important input elements for modelling of forest aboveground biomass. In this research work an approach is proposed to get reliable scattering from interferometric pair of fully Polarimetric RADARSAT-2 data. The field survey for data collection was carried out for Barkot forest during November 10th to December 5th, 2014. Stratified random sampling was used to collect field data for circumference at breast height (CBH) and tree height measurement. Field-measured AGB was compared with the volume scattering elements obtained from decomposition modelling of individual PolSAR images and PolInSAR coherency matrix. Yamaguchi 4-component decomposition was implemented to retrieve scattering elements from SAR data. PolInSAR based decomposition was the great challenge in this work and it was implemented with certain assumptions to create Hermitian coherency matrix with co-registered polarimetric interferometric pair of SAR data. Regression analysis between field-measured AGB and volume scattering element obtained from PolInSAR data showed highest (0.589) coefficient of determination. The same regression with volume scattering elements of individual SAR images showed 0.49 and 0.50 coefficients of determination for master and slave images respectively. This study recommends use of

  6. Polarimetric survey of main-belt asteroids⋆. III. Results for 33 X-type objects

    Science.gov (United States)

    Cañada-Assandri, M.; Gil-Hutton, R.; Benavidez, P.

    2012-06-01

    Aims: We present results of a polarimetric survey of main-belt asteroids at Complejo Astronómico El Leoncito (Casleo), San Juan, Argentina. The aims of this survey are to increase the database of asteroid polarimetry, to estimate diversity in polarimetric properties of asteroids that belong to different taxonomic classes, and to search for objects that exhibit anomalous polarimetric properties. Methods: The data were obtained with the Torino and CASPROF polarimeters at the 2.15 m telescope. The Torino polarimeter is an instrument that allows the simultaneous measurement of polarization in five different bands, and the CASPROF polarimeter is a two-hole aperture polarimeter with rapid modulation. Results: The survey began in 2003, and up to 2009 data of a sample of more than 170 asteroids were obtained. In this paper the results for 33 X-type objects are presented, several of them are being polarimetrically observed for the first time. Using these data we found polarization curves and polarimetric parameters for different groups among this taxonomic class and that there are objects with very different albedo in the sub-classes of the X taxonomic complex. Based on observations carried out at the Complejo Astronómico El Leoncito, operated under agreement between the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina and the National Universities of La Plata, Córdoba, and San Juan.Table 1 is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/542/A11

  7. Speckle Filtering of GF-3 Polarimetric SAR Data with Joint Restriction Principle.

    Science.gov (United States)

    Xie, Jinwei; Li, Zhenfang; Zhou, Chaowei; Fang, Yuyuan; Zhang, Qingjun

    2018-05-12

    Polarimetric SAR (PolSAR) scattering characteristics of imagery are always obtained from the second order moments estimation of multi-polarization data, that is, the estimation of covariance or coherency matrices. Due to the extra-paths that signal reflected from separate scatterers within the resolution cell has to travel, speckle noise always exists in SAR images and has a severe impact on the scattering performance, especially on single look complex images. In order to achieve high accuracy in estimating covariance or coherency matrices, three aspects are taken into consideration: (1) the edges and texture of the scene are distinct after speckle filtering; (2) the statistical characteristic should be similar to the object pixel; and (3) the polarimetric scattering signature should be preserved, in addition to speckle reduction. In this paper, a joint restriction principle is proposed to meet the requirement. Three different restriction principles are introduced to the processing of speckle filtering. First, a new template, which is more suitable for the point or line targets, is designed to ensure the morphological consistency. Then, the extent sigma filter is used to restrict the pixels in the template aforementioned to have an identical statistic characteristic. At last, a polarimetric similarity factor is applied to the same pixels above, to guarantee the similar polarimetric features amongst the optional pixels. This processing procedure is named as speckle filtering with joint restriction principle and the approach is applied to GF-3 polarimetric SAR data acquired in San Francisco, CA, USA. Its effectiveness of keeping the image sharpness and preserving the scattering mechanism as well as speckle reduction is validated by the comparison with boxcar filters and refined Lee filter.

  8. Airborne polarimetric Doppler weather radar: trade-offs between various engineering specifications

    Science.gov (United States)

    Vivekanandan, Jothiram; Loew, Eric

    2018-01-01

    NCAR EOL is investigating potential configurations for the next-generation airborne phased array radar (APAR) that is capable of retrieving dynamic and microphysical characteristics of clouds and precipitation. The APAR will operate at C band. The APAR will use the electronic scanning (e-scan) feature to acquire the optimal number of independent samples for recording research-quality measurements. Since the airborne radar has only a limited time for collecting measurements over a specified region (moving aircraft platform ˜ 100 m s-1), beam multiplexing will significantly enhance its ability to collect high-resolution, research-quality measurements. Beam multiplexing reduces errors in radar measurements while providing rapid updates of scan volumes. Beamwidth depends on the size of the antenna aperture. Beamwidth and directivity of elliptical, circular, and rectangular antenna apertures are compared and radar sensitivity is evaluated for various polarimetric configurations and transmit-receive (T/R) elements. In the case of polarimetric measurements, alternate transmit with alternate receive (single-channel receiver) and simultaneous reception (dual-channel receiver) is compared. From an overall architecture perspective, element-level digitization of T/R module versus digital sub-array is considered with regard to flexibility in adaptive beamforming, polarimetric performance, calibration, and data quality. Methodologies for calibration of the radar and removing bias in polarimetric measurements are outlined. The above-mentioned engineering options are evaluated for realizing an optimal APAR system suitable for measuring the high temporal and spatial resolutions of Doppler and polarimetric measurements of precipitation and clouds.

  9. The Direct Detection and Characterization of M-dwarf Planets Using Light Echoes

    Science.gov (United States)

    Sparks, William B.; White, Richard L.; Lupu, Roxana E.; Ford, Holland C.

    2018-02-01

    Exoplanets orbiting M-dwarf stars are a prime target in the search for life in the universe. M-dwarf stars are active, with powerful flares that could adversely impact prospects for life, though there are counter-arguments. Here, we turn flaring to advantage and describe ways in which it can be used to enhance the detectability of planets, in the absence of transits or a coronagraph, significantly expanding the accessible discovery and characterization space. Flares produce brief bursts of intense luminosity, after which the star dims. Due to the light travel time between the star and planet, the planet receives the high-intensity pulse, which it re-emits through scattering (a light echo) or intrinsic emission when the star is much fainter, thereby increasing the planet’s detectability. The planet’s light-echo emission can potentially be discriminated from that of the host star by means of a time delay, Doppler shift, spatial shift, and polarization, each of which can improve the contrast of the planet to the star. Scattered light can reveal the albedo spectrum of the planet to within a size scale factor, and is likely to be polarized. Intrinsic emission mechanisms include fluorescent pumping of multiple molecular hydrogen and neutral oxygen lines by intense Lyα and Lyβ flare emission, recombination radiation of ionized and photodissociated species, and atmospheric processes such as terrestrial upper atmosphere airglow and near-infrared hydroxyl emission. We discuss the feasibility of detecting light echoes and find that light echo detection is possible under favorable circumstances.

  10. Characterization of deep energy levels in mercury iodide. Application to nuclear detection

    International Nuclear Information System (INIS)

    Mohammed Brahim, Tayeb.

    1982-07-01

    The last few years have seen an increasing interest in HgI 2 detectors for room temperature gamma and X-ray spectrometry. Performance and effective thickness of these detectors are presently limited by carrier trapping which results in incomplete charge collection. Characterization of the trapping levels has been performed by several photoelectronic methods (photoconductivity, thermal and optical quenching of the photoconductivity, TSC, lifetime measurement). A model is proposed taking into account the results obtained by these techniques and the polarization phenomena observed in nuclear detection in both vapor phase and solution grown crystals. For the latter, polarization can be eliminated or notably reduced by illumination of the positive electrode or by using a MIS positively biased structure [fr

  11. Characterization and detection of thermoacoustic combustion oscillations based on statistical complexity and complex-network theory

    Science.gov (United States)

    Murayama, Shogo; Kinugawa, Hikaru; Tokuda, Isao T.; Gotoda, Hiroshi

    2018-02-01

    We present an experimental study on the characterization of dynamic behavior of flow velocity field during thermoacoustic combustion oscillations in a turbulent confined combustor from the viewpoints of statistical complexity and complex-network theory, involving detection of a precursor of thermoacoustic combustion oscillations. The multiscale complexity-entropy causality plane clearly shows the possible presence of two dynamics, noisy periodic oscillations and noisy chaos, in the shear layer regions (1) between the outer recirculation region in the dump plate and a recirculation flow in the wake of the centerbody and (2) between the outer recirculation region in the dump plate and a vortex breakdown bubble away from the centerbody. The vertex strength in the turbulence network and the community structure of the vorticity field can identify the vortical interactions during thermoacoustic combustion oscillations. Sequential horizontal visibility graph motifs are useful for capturing a precursor of themoacoustic combustion oscillations.

  12. Detection and characterization of exercise induced muscle damage (EIMD) via thermography and image processing

    DEFF Research Database (Denmark)

    Avdelidis, Nicolas; Kappatos, Vassilios; Georgoulas, George

    2017-01-01

    of commonly measurement tools and methods. Thermography has been used successfully as a research detection tool in medicine for the last 6 decades but very limited work has been reported on EIMD area. The main purpose of this research is to assess and characterize EIMD, using thermography and image processing...... techniques. The first step towards that goal is to develop a reliable segmentation technique to isolate the region of interest (ROI). A semi-automatic image processing software was designed and regions of the left and right leg based on superpixels were segmented. The image is segmented into a number...... of regions and the user is able to intervene providing the regions which belong to each of the two legs. In order to validate the image processing software, an extensive experimental investigation was carried out, acquiring thermographic images of the rectus femoris muscle before, immediately post and 24, 48...

  13. Advances on the molecular characterization, clinical relevance, and detection methods of Gadiform parvalbumin allergens.

    Science.gov (United States)

    Fernandes, Telmo J R; Costa, Joana; Carrapatoso, Isabel; Oliveira, Maria Beatriz P P; Mafra, Isabel

    2017-10-13

    Gadiform order includes several fish families, from which Gadidae and Merlucciidae are part of, comprising the most commercially important and highly appreciated fish species, such as cod, pollock, haddock, and hake. Parvalbumins, classified as calcium-binding proteins, are considered the main components involved in the majority of fish allergies. Nine and thirteen parvalbumins were identified in different fish species from Gadidae and Merlucciidae families, respectively. This review intends to describe their molecular characterization and the clinical relevance, as well as the prevalence of fish allergy. In addition, the main protein- and DNA-based methods to detect fish allergens are fully reviewed owing to their importance in the safeguard of sensitized/allergic individuals.

  14. Developmental techniques for ultrasonic flaw detection and characterization in stainless steel

    International Nuclear Information System (INIS)

    Kupperman, D.S.

    1983-04-01

    Flaw detection and characterization by ultrasonic methods is particularly difficult for stainless steel. This paper focuses on two specific problem areas: (a) the inspection of centrifugally cast stainless steel (CCSS) and (b) the differentiation of intergranular stress-corrosion cracking (IGSCC) from geometrical reflectors such as the weld root. To help identify optimal conditions for the ultrasonic inspection of CCSS, the effect of frequency on propagation of longitudinal and shear waves was examined in both isotropic and anisotropic samples. Good results were obtained with isotropic CCSS and 0.5-MHz angle beam shear waves. The use of beam-scattering patterns (i.e. signal amplitude vs skew angle) as a tool for discriminating IGSCC from geometrical reflectors is also discussed

  15. Active and passive infrared thermography applied to the detection and characterization of hidden defects in structure

    Science.gov (United States)

    Dumoulin, Jean

    2013-04-01

    Infrared thermography for Non Destructive Testing (NDT) has encountered a wide spreading this last 2 decades, in particular thanks to emergence on the market of low cost uncooled infrared camera. So, infrared thermography is not anymore a measurement technique limited to laboratory application. It has been more and more involved in civil engineering and cultural heritage applications, but also in many other domains, as indicated by numerous papers in the literature. Nevertheless, laboratory, measurements are done as much as possible in quite ideal conditions (good atmosphere conditions, known properties of materials, etc.), while measurement on real site requires to consider the influence of not controlled environmental parameters and additional unknown thermal properties. So, dedicated protocol and additional sensors are required for measurement data correction. Furthermore, thermal excitation is required to enhance the signature of defects in materials. Post-processing of data requires to take into account the protocol used for the thermal excitation and sometimes its nature to avoid false detection. This analysis step is based on signal and image processing tool and allows to carry out the detection. Characterization of anomalies detected at the previous step can be done by additional signal processing in particular for manufactured objects. The use of thermal modelling and inverse method allows to determine properties of the defective area. The present paper will first address a review of some protocols currently in use for field measurement with passive and/or active infrared measurements. Illustrations in various experiments carried out on civil engineering structure will be shown and discussed. In a second part, different post-processing approaches will be presented and discussed. In particular, a review of the most standard processing methods like Fast Fourier Analysis, Principal Components Analysis, Polynomial Decomposition, defect characterization using

  16. Characterizing SOI Wafers By Use Of AOTF-PHI

    Science.gov (United States)

    Cheng, Li-Jen; Li, Guann-Pyng; Zang, Deyu

    1995-01-01

    Developmental nondestructive method of characterizing layers of silicon-on-insulator (SOI) wafer involves combination of polarimetric hyperspectral imaging by use of acousto-optical tunable filters (AOTF-PHI) and computational resources for extracting pertinent data on SOI wafers from polarimetric hyperspectral images. Offers high spectral resolution and both ease and rapidity of optical-wavelength tuning. Further efforts to implement all of processing of polarimetric spectral image data in special-purpose hardware for sake of procesing speed. Enables characterization of SOI wafers in real time for online monitoring and adjustment of production. Also accelerates application of AOTF-PHI to other applications in which need for high-resolution spectral imaging, both with and without polarimetry.

  17. Detection and characterization of side population in Ewing's sarcoma SK-ES-1 cells in vitro

    International Nuclear Information System (INIS)

    Yang, Min; Zhang, Rui; Yan, Ming; Ye, Zhengxu; Liang, Wei; Luo, Zhuojing

    2010-01-01

    Dye exclusion is a valuable technique to isolate cancer stem cells (CSCs) based on an ability of stem cell to efflux fluorescent DNA-binding dye, especially for tumors without unique surface markers. It has been proven that side population (SP) cells that exclude Hoechst 33342 dye are enriched with stem-like cells in several cancer cell lines. In this study, we isolated and characterized SP cells from human Ewing's sarcoma cell line SK-ES-1 in vitro. SP cells were detected in SK-ES-1 and comprised 1.2% of total cell population. Only SP cells had the capacity to regenerate both SP and non-SP cells. The proliferation rates were similar between SP and non-SP cells. However, the clonogenicity and invasiveness of SP cells were significantly higher than that of non-SP cells. Further characterization of this SP phenotype presented other properties. SP cells exhibited increased multi-drug resistance and the ATP binding cassette protein (ABC) transporters were up-regulated in SP population. These findings suggest that SP cells derived from Ewing's sarcoma play the critical role in tumor metastasis and recurrence and might be an ideal target for clinical therapy.

  18. Genetic characterization, species differentiation and detection of Fasciola spp. by molecular approaches

    Directory of Open Access Journals (Sweden)

    Li Hai-Long

    2011-06-01

    Full Text Available Abstract Liver flukes belonging to the genus Fasciola are among the causes of foodborne diseases of parasitic etiology. These parasites cause significant public health problems and substantial economic losses to the livestock industry. Therefore, it is important to definitively characterize the Fasciola species. Current phenotypic techniques fail to reflect the full extent of the diversity of Fasciola spp. In this respect, the use of molecular techniques to identify and differentiate Fasciola spp. offer considerable advantages. The advent of a variety of molecular genetic techniques also provides a powerful method to elucidate many aspects of Fasciola biology, epidemiology, and genetics. However, the discriminatory power of these molecular methods varies, as does the speed and ease of performance and cost. There is a need for the development of new methods to identify the mechanisms underpinning the origin and maintenance of genetic variation within and among Fasciola populations. The increasing application of the current and new methods will yield a much improved understanding of Fasciola epidemiology and evolution as well as more effective means of parasite control. Herein, we provide an overview of the molecular techniques that are being used for the genetic characterization, detection and genotyping of Fasciola spp..

  19. Genetic characterization, species differentiation and detection of Fasciola spp. by molecular approaches.

    Science.gov (United States)

    Ai, Lin; Chen, Mu-Xin; Alasaad, Samer; Elsheikha, Hany M; Li, Juan; Li, Hai-Long; Lin, Rui-Qing; Zou, Feng-Cai; Zhu, Xing-Quan; Chen, Jia-Xu

    2011-06-10

    Liver flukes belonging to the genus Fasciola are among the causes of foodborne diseases of parasitic etiology. These parasites cause significant public health problems and substantial economic losses to the livestock industry. Therefore, it is important to definitively characterize the Fasciola species. Current phenotypic techniques fail to reflect the full extent of the diversity of Fasciola spp. In this respect, the use of molecular techniques to identify and differentiate Fasciola spp. offer considerable advantages. The advent of a variety of molecular genetic techniques also provides a powerful method to elucidate many aspects of Fasciola biology, epidemiology, and genetics. However, the discriminatory power of these molecular methods varies, as does the speed and ease of performance and cost. There is a need for the development of new methods to identify the mechanisms underpinning the origin and maintenance of genetic variation within and among Fasciola populations. The increasing application of the current and new methods will yield a much improved understanding of Fasciola epidemiology and evolution as well as more effective means of parasite control. Herein, we provide an overview of the molecular techniques that are being used for the genetic characterization, detection and genotyping of Fasciola spp..

  20. Detection and characterization of interleukin-6 gene variants in Canis familiaris: association studies with periodontal disease.

    Science.gov (United States)

    Morinha, Francisco; Albuquerque, Carlos; Requicha, João; Dias, Isabel; Leitão, José; Gut, Ivo; Guedes-Pinto, Henrique; Viegas, Carlos; Bastos, Estela

    2011-10-10

    Periodontal disease (PD) is the most common inflammatory disease of the oral cavity of domestic carnivores. In Human Medicine molecular genetics research showed that several genes play a role in the predisposition and progression of this complex disease, primarily through the regulation of inflammatory mediators, but the exactly mechanisms are poorly understood. This study aims to contribute to the characterization of the genetic basis of PD in the dog, a classically accepted model in Periodontology. We searched for genetic variations in the interleukin-6 (IL6) gene, in order to verify its association with PD in a case-control study including 25 dogs in the PD case group and 45 dogs in the control group. We indentified and characterized three new genetic variations in IL6 gene. No statistically significant differences were detected between the control and PD cases groups. Our results do not support an evidence for a major role contribution of these variants in the susceptibility to PD in the analyzed population. Nevertheless, the sequence variant I/5_g.105G>A leads to an amino acid change (arginine to glutamine) and was predicted to be possibly damaging to the IL6 protein. A larger cohort and functional studies would be of extreme importance in a near future to understand the possible role of IL6 variants in this disease. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Fabrication and characterization of junctionless carbon nanotube field effect transistor for cholesterol detection

    Energy Technology Data Exchange (ETDEWEB)

    Barik, Md. Abdul, E-mail: abdulnpl@gmail.com; Dutta, Jiten Ch. [Department of Electronics and Communication Engineering, Tezpur University, Napaam, Tezpur, Assam 784028 (India)

    2014-08-04

    We have reported fabrication and characterization of polyaniline (PANI)/zinc oxide (ZnO) membrane-based junctionless carbon nanotube field effect transistor deposited on indium tin oxide glass plate for the detection of cholesterol (0.5–22.2 mM). Cholesterol oxidase (ChOx) has been immobilized on the PANI/ZnO membrane by physical adsorption technique. Electrical response has been recorded using digital multimeter (Agilent 3458A) in the presence of phosphate buffer saline of 50 mM, pH 7.0, and 0.9% NaCl contained in a glass pot. The results of response studies for cholesterol reveal linearity as 0.5–16.6 mM and improved sensitivity of 60 mV/decade in good agreement with Nernstian limit ∼59.2 mV/decade. The life time of this sensor has been found up to 5 months and response time of 1 s. The limit of detection with regression coefficient (r) ∼ 0.998 and Michaelis-Menten constant (K{sub m}) were found to be ∼0.25 and 1.4 mM, respectively, indicating high affinity of ChOx to cholesterol. The results obtained in this work show negligible interference with glucose and urea.

  2. Preliminary characterization of a single photon counting detection system for CT application

    International Nuclear Information System (INIS)

    Belcari, N.; Bisogni, M.G.; Carpentieri, C.; Del Guerra, A.; Delogu, P.; Panetta, D.; Quattrocchi, M.; Rosso, V.; Stefanini, A.

    2007-01-01

    The aim of this work is to evaluate the capability of a single photon counting acquisition system based on the Medipix2 read-out chip for Computed Tomography (CT) applications in Small Animal Imaging. We used a micro-focus X-ray source with a W anode. The detection system is based on the Medipix2 read-out chip, bump-bonded to a 1 mm thick silicon pixel detector. The read-out chip geometry is a matrix of 256x256 cells, 55 μmx55 μm each. This system in planar radiography shows a good detection efficiency (about 70%) at the anode voltage of 30 kV and a good spatial resolution (MTF=10% at 16.8 lp/mm). Starting from these planar performances we have characterized the system for the tomography applications with phantoms. We will present the results obtained as a function of magnification with two different background medium compositions. The effect of the reconstruction algorithm on image quality will be also discussed

  3. Development and characterization of an electrochemical sensor for furosemide detection based on electropolymerized molecularly imprinted polymer.

    Science.gov (United States)

    Kor, Kamalodin; Zarei, Kobra

    2016-01-01

    A novel electrochemical sensor based on a molecularly imprinted polymer, poly(o-phenylenediamine) (PoPD), has been developed for selective and sensitive detection of furosemide. The sensor was prepared by incorporating of furosemide as template molecules during the electropolymerization of o-phenylenediamine on a gold electrode. To develop the molecularly imprinted polymer (MIP), the template molecules were removed from the modified electrode's surface by washing it with 0.25 mol L(-1) NaOH solution. The imprinted layer was characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and atomic force microscopy (AFM). The sensor's preparation conditions including furosemide concentration, the number of CV cycles in the electropolymerization process, extraction solution of the template from the imprinted film, the incubation time and the pH level were optimized. The incubation of the MIP-modified electrode, with respect to furosemide concentration, resulted in a suppression of the K4[Fe(CN)6] oxidation process. Under the optimal experimental conditions, the response of the imprinted sensor was linear in the range of 1.0×10(-7)-7.0×10(-6) mol L(-1) of furosemide. The detection limit was obtained as 7.0×10(-8) mol L(-1) for furosemide by using this sensor. The sensor was successfully used to determine the furosemide amount in the tablet and in human urine samples with satisfactory results. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. The RF Probe: providing space situational awareness through broad-spectrum detection and characterization

    Science.gov (United States)

    Zenick, Raymond; Kohlhepp, Kimberly; Partch, Russell

    2004-09-01

    AeroAstro's patented RF Probe is a system designed to address the needs of spacecraft developers and operators interested in measuring and analyzing near-field RF emissions emanating from a nearby spacecraft of interest. The RF Probe consists of an intelligent spectrum analyzer with digital signal processing capabilities combined with a calibrated, wide-bandwidth antenna and RF front end that covers the 50 kHz to 18 GHz spectrum. It is capable of acquiring signal level and signal vector information, classifying signals, assessing the quality of a satellite"s transponders, and characterizing near-field electromagnetic emissions. The RF Probe is intended for either incorporation as part of a suite of spacecraft sensors, or as a stand-alone sensor on spacecraft or other platforms such as Unmanned Aerial Vehicles (UAVs). The RF Probe was initially conceived as a tool to detect and aid in diagnosis of malfunctions in a spacecraft of interest. However, the utility of the RF Probe goes far beyond this initial concept, spanning a wide range of military applications. Most importantly, the RF Probe can provide space situational awareness for critical on-orbit assets by detecting externally induced RF fields, aiding in protection against potentially devastating attacks.

  5. Synthesis and characterization of near IR fluorescent albumin nanoparticles for optical detection of colon cancer

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, Sarit; Pellach, Michal [Department of Chemistry, Bar-Ilan Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900 (Israel); Kam, Yossi [Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, P.O. Box 12065, Jerusalem 91120 (Israel); Grinberg, Igor; Corem-Salkmon, Enav [Department of Chemistry, Bar-Ilan Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900 (Israel); Rubinstein, Abraham [Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, P.O. Box 12065, Jerusalem 91120 (Israel); Margel, Shlomo, E-mail: shlomo.margel@mail.biu.ac.il [Department of Chemistry, Bar-Ilan Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900 (Israel)

    2013-03-01

    Near IR (NIR) fluorescent human serum albumin (HSA) nanoparticles hold great promise as contrast agents for tumor diagnosis. HSA nanoparticles are considered to be biocompatible, non-toxic and non-immunogenic. In addition, NIR fluorescence properties of these nanoparticles are important for in vivo tumor diagnostics, with low autofluorescence and relatively deep penetration of NIR irradiation due to low absorption of biomatrices. The present study describes the synthesis of new NIR fluorescent HSA nanoparticles, by entrapment of a NIR fluorescent dye within the HSA nanoparticles, which also significantly increases the photostability of the dye. Tumor-targeting ligands such as peanut agglutinin (PNA) and anti-carcinoembryonic antigen antibodies (anti-CEA) were covalently conjugated to the NIR fluorescent albumin nanoparticles, increasing the potential fluorescent signal in tumors with upregulated corresponding receptors. Specific colon tumor detection by the NIR fluorescent HSA nanoparticles was demonstrated in a chicken embryo model and a rat model. In future work we also plan to encapsulate cancer drugs such as doxorubicin within the NIR fluorescent HSA nanoparticles for both colon cancer imaging and therapy. - Highlights: Black-Right-Pointing-Pointer Near IR human serum albumin nanoparticles were synthesized and characterized. Black-Right-Pointing-Pointer Nanoparticles were shown to be physically and chemically stable and photostable. Black-Right-Pointing-Pointer Tumor-targeting ligands were covalently conjugated to the nanoparticles. Black-Right-Pointing-Pointer Specific colon cancer tumor detection was demonstrated in chicken-embryo and rat models.

  6. Synthesis and characterization of near IR fluorescent albumin nanoparticles for optical detection of colon cancer

    International Nuclear Information System (INIS)

    Cohen, Sarit; Pellach, Michal; Kam, Yossi; Grinberg, Igor; Corem-Salkmon, Enav; Rubinstein, Abraham; Margel, Shlomo

    2013-01-01

    Near IR (NIR) fluorescent human serum albumin (HSA) nanoparticles hold great promise as contrast agents for tumor diagnosis. HSA nanoparticles are considered to be biocompatible, non-toxic and non-immunogenic. In addition, NIR fluorescence properties of these nanoparticles are important for in vivo tumor diagnostics, with low autofluorescence and relatively deep penetration of NIR irradiation due to low absorption of biomatrices. The present study describes the synthesis of new NIR fluorescent HSA nanoparticles, by entrapment of a NIR fluorescent dye within the HSA nanoparticles, which also significantly increases the photostability of the dye. Tumor-targeting ligands such as peanut agglutinin (PNA) and anti-carcinoembryonic antigen antibodies (anti-CEA) were covalently conjugated to the NIR fluorescent albumin nanoparticles, increasing the potential fluorescent signal in tumors with upregulated corresponding receptors. Specific colon tumor detection by the NIR fluorescent HSA nanoparticles was demonstrated in a chicken embryo model and a rat model. In future work we also plan to encapsulate cancer drugs such as doxorubicin within the NIR fluorescent HSA nanoparticles for both colon cancer imaging and therapy. - Highlights: ► Near IR human serum albumin nanoparticles were synthesized and characterized. ► Nanoparticles were shown to be physically and chemically stable and photostable. ► Tumor-targeting ligands were covalently conjugated to the nanoparticles. ► Specific colon cancer tumor detection was demonstrated in chicken-embryo and rat models.

  7. Detection and characterization of Babesia species in Ixodes ticks in Estonia.

    Science.gov (United States)

    Katargina, Olga; Geller, Julia; Vasilenko, Veera; Kuznetsova, Tatiana; Järvekülg, Lilian; Vene, Sirkka; Lundkvist, Åke; Golovljova, Irina

    2011-07-01

    The presence of Babesia spp. was studied in 2603 Ixodes ricinus and Ixodes persulcatus ticks collected at seven sites in Estonia. By reverse line blot screening, Babesia spp. was detected in 36 (1.4%) ticks, among them 18 (0.7%) were further recognized by a Babesia microti probe, 3 (0.1%) by a Babesia divergens probe, and the other 15 (0.6%) were recognized only by the universal Babesia spp. "catch all" probe. Sequence analyses of 6 of these 15 samples revealed that all of them belonged to Babesia sp. EU1. B. microti was detected in both tick species I. ricinus and I. persulcatus at the seven sites, whereas B. divergens-like and Babesia sp. EU1 were found only in I. persulcatus and I. ricinus, respectively. Genetic characterization based on partial 18S rRNA showed that the Estonian sequences of B. microti, B. divergens-like, and Babesia sp. EU1 share a high rate of similarity and are closely related to sequences from other European countries, Siberia, and United States. The present study demonstrated for the first time the existence and distribution of Babesia spp. in I. persulcatus and I. ricinus ticks in Estonia.

  8. Detection, purification and characterization of a lectin from freshwater green algae Spirogyra spp.

    Directory of Open Access Journals (Sweden)

    ANTÔNIA S. DE OLIVEIRA

    2017-08-01

    Full Text Available ABSTRACT Freshwater algae are rich sources of structurally biologically active metabolites, such as fatty acids, steroids, carotenoids and polysaccharides. Among these metabolites, lectins stand out. Lectins are proteins or glycoproteins of non-immune origin which bind to carbohydrates or glycoconjugates, without changing ligand structure. Many studies have reported on the use of Spirogyra spp. as effective bioindicators of heavy metals; however, reports on Spirogyra molecular bioprospecting are quite limited. Therefore, this study aimed to detect, isolate, purify and characterize a lectin present in the freshwater green algae Spirogyra. Presence of the lectin protein in the extract was detected by hemagglutination assays. Subsequently, the protein extract was subjected to a sugar inhibition assay to identify the lectin-specific carbohydrate. Following this, the extract was applied to a guar gum column to afford the pure lectin. The lectin was inhibited by N-acetyl-glucosamine and N-acetyl-beta-D-mannose, but more strongly by D-galactose. The apparent molecular mass of the purified lectin was evaluated by Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE. Electrophoretic analysis revealed a single protein band with an apparent molecular mass of 56 kDa. Thus, it could be concluded that a lectin was purified from Spirogyra spp.

  9. Polyp Detection, Characterization, and Management Using Narrow-Band Imaging with/without Magnification

    Directory of Open Access Journals (Sweden)

    Takahiro Utsumi

    2015-11-01

    Full Text Available Narrow-band imaging (NBI is a new imaging technology that was developed in 2006 and has since spread worldwide. Because of its convenience, NBI has been replacing the role of chromoendoscopy. Here we review the efficacy of NBI with/without magnification for detection, characterization, and management of colorectal polyps, and future perspectives for the technology, including education. Recent studies have shown that the next-generation NBI system can detect significantly more colonic polyps than white light imaging, suggesting that NBI may become the modality of choice from the beginning of screening. The capillary pattern revealed by NBI, and the NBI International Colorectal Endoscopic classification are helpful for prediction of histology and for estimating the depth of invasion of colorectal cancer. However, NBI with magnifying colonoscopy is not superior to magnifying chromoendoscopy for estimation of invasion depth. Currently, therefore, chromoendoscopy should also be performed additionally if deep submucosal invasive cancer is suspected. If endoscopists become able to accurately estimate colorectal polyp pathology using NBI, this will allow adenomatous polyps to be resected and discarded; thus, reducing both the risk of polypectomy and costs. In order to achieve this goal, a suitable system for education and training in in vivo diagnostics will be necessary.

  10. Detection and characterization of Ah receptor in tissue and cells from human tonsils

    International Nuclear Information System (INIS)

    Lorenzen, A.; Okey, A.B.

    1991-01-01

    Ah receptor was identified and characterized in cytosol and nuclear extracts from human tonsils obtained at surgery from children 2 to 6 years of age. Ah receptor was found in cytosol prepared from whole-tonsil homogenates as well as in cytosol and nuclear fractions prepared from tonsil lymphocytes or tonsil fibroblasts grown in primary culture. Cytosolic Ah receptor was detectable in tonsillar tissue with either halogenated (2,3,7,8-[3H]tetrachlorodibenzo-p-dioxin (TCDD)) or nonhalogenated (3-[3H]methylcholanthrene and [3H]benzo[a]pyrene) aromatic hydrocarbons and sedimented at approximately 9 S after velocity sedimentation on sucrose gradients. The apparent binding affinity (Kd) of [3H]TCDD for Ah receptor ranged from 3 to 12 nM in cytosols from seven different donors. The same analyses indicated a concentration of Ah receptor in human tonsils of approximately 100-300 fmol/mg cytosolic protein. Incubation of either tonsil lymphocytes or tonsil fibroblasts with [3H]TCDD resulted in transformation of cytosolic Ah receptor to a nuclear binding form which could be detected as a specifically labeled peak sedimenting at approximately 6 S on sucrose gradients. These data demonstrate the existence of Ah receptor in human tonsils and suggest that this immune organ may be an appropriate model for further studies on the mechanism and manifestation of aromatic hydrocarbon-induced immunotoxicity in man

  11. Worlds Beyond: A Strategy for the Detection and Characterization of Exoplanets

    Energy Technology Data Exchange (ETDEWEB)

    Lunine, J; Fischer, D; Hammel, H; Hillenbrand, L; Kasting, J; Laughlin, G; Macintosh, B; Marley, M; Melnick, G; Monet, D; Noecker, C; Peale, S; Quirrenbach, A; Seager, S; Winn, J

    2008-06-02

    This report is a comprehensive study of the search for and study of planets around other stars (exoplanets). The young but maturing field of exoplanets is perhaps one of the most compelling fields of study in science today--both because of the discoveries made to date on giant planets around other stars, and because the detection of planets just like our Earth ('Earth analogs') is at last within reach technologically. In the Report we outline the need for a vigorous research program in exoplanets to understand our place in the cosmos: whether planets like our home Earth are a common or rare outcome of cosmic evolution. The strategy we developed is intended to address the following fundamental questions, in priority order, within three distinct 5-yr long phases, over a 15 year period: (1) What are the physical characteristics of planets in the habitable zones around bright, nearby stars? (2) What is the architecture of planetary systems? (3) When, how and in what environments are planets formed? The Report recommends a two-pronged strategy for the detection and characterization of planets the size of the Earth. For stars much less massive and cooler than our Sun (M-dwarfs), existing ground-based techniques including radial velocity and transit searches, and space-based facilities both existing and under development such as Spitzer and JWST, are adequate for finding and studying planets close to the mass and size of the Earth. Conducted in parallel with the M-dwarf strategy is one for the more challenging observations of the hotter and brighter F, G, and K stars, some of which are very close in properties to our Sun, in which the frequency of Earth-sized planets is assessed with Corot and Kepler, but new space missions are required for detection and study of specific Earth-mass and Earth-sized objects. Our Task Force concludes that the development of a space-based astrometric mission, narrowly-focused to identify specific nearby stars with Earth

  12. Combined gadoxetic acid and gadofosveset enhanced liver MRI for detection and characterization of liver metastases

    International Nuclear Information System (INIS)

    Bannas, Peter; Bookwalter, Candice A.; Ziemlewicz, Tim; Munoz del Rio, Alejandro; Potretzke, Theodora A.; Motosugi, Utaroh; Nagle, Scott K.; Reeder, Scott B.

    2017-01-01

    To compare gadoxetic acid alone and combined gadoxetic acid/gadofosveset trisodium-enhanced liver MRI for detection of metastases and differentiation of metastases from haemangiomas. Ninety-one patients underwent gadoxetic acid-enhanced liver MRI before and after additional injection of gadofosveset. First, two readers retrospectively identified metastases on gadoxetic acid alone enhanced delayed hepatobiliary phase T1-weighted images together with all other MR images (dynamic images, T2-weighted images, diffusion-weighted images). Second, readers assessed additional T1-weighted images obtained after administration of gadofosveset trisodium. For both interpretations, readers rated lesion conspicuity and confidence in differentiating metastases from haemangiomas. Results were compared using alternative free-response receiver-operating characteristic (AFROC) and conventional ROC methods. Histology and follow-up served as reference standard. There were 145 metastases and 16 haemangiomas. Both readers detected more metastases using combined gadoxetic acid/gadofosveset (reader 1 = 130; reader 2 = 124) compared to gadoxetic acid alone (reader 1 = 104; reader 2 = 103). Sensitivity of combined gadoxetic acid/gadofosveset (reader 1 = 90 %; reader 2 = 86 %) was higher than that of gadoxetic acid alone (reader 1 = 72 %; reader 2 = 71 %, both P < 0.01). AFROC-AUC was higher for the combined technique (0.92 vs. 0.86, P < 0.001). Sensitivity for correct differentiation of metastases from haemangiomas was higher for the combined technique (reader 1 = 98 %; reader 2 = 99 % vs. reader 1 = 86 %; reader 2 = 91 %, both P < 0.01). ROC-AUC was significantly higher for the combined technique (reader 1 = 1.00; reader 2 = 1.00 vs. reader 1 = 0.87; reader 2 = 0.92, both P < 0.01). Combined gadoxetic acid/gadofosveset-enhanced MRI improves detection and characterization of liver metastases compared to gadoxetic acid alone. (orig.)

  13. Combined gadoxetic acid and gadofosveset enhanced liver MRI for detection and characterization of liver metastases

    Energy Technology Data Exchange (ETDEWEB)

    Bannas, Peter [University of Wisconsin-Madison, Department of Radiology, Madison, WI (United States); University Medical Center Hamburg-Eppendorf, Department of Radiology, University Hospital, Hamburg (Germany); Bookwalter, Candice A.; Ziemlewicz, Tim; Munoz del Rio, Alejandro; Potretzke, Theodora A. [University of Wisconsin-Madison, Department of Radiology, Madison, WI (United States); Motosugi, Utaroh [University of Wisconsin-Madison, Department of Radiology, Madison, WI (United States); University of Yamanashi, Department of Radiology, Yamanashi (Japan); Nagle, Scott K. [University of Wisconsin-Madison, Department of Radiology, Madison, WI (United States); University of Wisconsin-Madison, Department of Medical Physics, Madison, WI (United States); University of Wisconsin-Madison, Department of Pediatrics, Madison, WI (United States); Reeder, Scott B. [University of Wisconsin-Madison, Department of Radiology, Madison, WI (United States); University of Wisconsin-Madison, Department of Medical Physics, Madison, WI (United States); University of Wisconsin-Madison, Department of Biomedical Engineering, Madison, WI (United States); University of Wisconsin-Madison, Department of Medicine, Madison, WI (United States); University of Wisconsin-Madison, Department of Emergency Medicine, Madison, WI (United States)

    2017-01-15

    To compare gadoxetic acid alone and combined gadoxetic acid/gadofosveset trisodium-enhanced liver MRI for detection of metastases and differentiation of metastases from haemangiomas. Ninety-one patients underwent gadoxetic acid-enhanced liver MRI before and after additional injection of gadofosveset. First, two readers retrospectively identified metastases on gadoxetic acid alone enhanced delayed hepatobiliary phase T1-weighted images together with all other MR images (dynamic images, T2-weighted images, diffusion-weighted images). Second, readers assessed additional T1-weighted images obtained after administration of gadofosveset trisodium. For both interpretations, readers rated lesion conspicuity and confidence in differentiating metastases from haemangiomas. Results were compared using alternative free-response receiver-operating characteristic (AFROC) and conventional ROC methods. Histology and follow-up served as reference standard. There were 145 metastases and 16 haemangiomas. Both readers detected more metastases using combined gadoxetic acid/gadofosveset (reader 1 = 130; reader 2 = 124) compared to gadoxetic acid alone (reader 1 = 104; reader 2 = 103). Sensitivity of combined gadoxetic acid/gadofosveset (reader 1 = 90 %; reader 2 = 86 %) was higher than that of gadoxetic acid alone (reader 1 = 72 %; reader 2 = 71 %, both P < 0.01). AFROC-AUC was higher for the combined technique (0.92 vs. 0.86, P < 0.001). Sensitivity for correct differentiation of metastases from haemangiomas was higher for the combined technique (reader 1 = 98 %; reader 2 = 99 % vs. reader 1 = 86 %; reader 2 = 91 %, both P < 0.01). ROC-AUC was significantly higher for the combined technique (reader 1 = 1.00; reader 2 = 1.00 vs. reader 1 = 0.87; reader 2 = 0.92, both P < 0.01). Combined gadoxetic acid/gadofosveset-enhanced MRI improves detection and characterization of liver metastases compared to gadoxetic acid alone. (orig.)

  14. Screen film vs full-field digital mammography: image quality, detectability and characterization of lesions

    International Nuclear Information System (INIS)

    Obenauer, S.; Luftner-Nagel, S.; Heyden, D. von; Baum, F.; Grabbe, E.; Munzel, U.

    2002-01-01

    The objective of this study was to compare screen-film mammography (SFM) to full-field digital mammography (FFDM) regarding image quality as well as detectability and characterization of lesions using equivalent images of the same patient acquired with both systems. Two mammography units were used, one with a screen-film system (Senographe DMR) and the other with a digital detector (Senographe 2000D, both GEMS). Screen-film and digital mammograms were performed on 55 patients with cytologically or histologically proven tumors on the same day. Together with these, 75 digital mammograms of patients without tumor and the corresponding previous screen-film mammograms not older than 1.5 years were reviewed by three observers in a random order. Contrast, exposure, and the presence of artifacts were evaluated. Different details, such as the skin, the retromamillary region, and the parenchymal structures, were judged according to a three-point ranking scale. Finally, the detectability of microcalcifications and lesions were compared and correlated to histology. Image contrast was judged to be good in 76%, satisfactory in 20%, and unsatisfactory in 4% of screen-film mammograms. Digital mammograms were judged to be good in 99% and unsatisfactory in 1% of cases. Improper exposure of screen-film system occurred in 18% (10% overexposed and 8% underexposed). Digital mammograms were improperly exposed in 4% of all cases but were of acceptable quality after post-processing. Artifacts, most of them of no significance, were found in 78% of screen-film and in none of the digital mammograms. Different anatomical regions, such as the skin, the retromamillary region, and dense parenchymal areas, were better visualized in digital than in screen-film mammography. All malignant tumors were seen by the three radiologists; however, digital mammograms allowed a better characterization of these lesions to the Breast Imaging Reporting and Data System (BI-RADSZZZ;) categories (FFDM better than

  15. An Airborne Campaign Measuring Wind Signatures from the Sea Surface using an L-band Polarimetric Radiometer

    DEFF Research Database (Denmark)

    Søbjærg, Sten Schmidl; Skou, Niels

    2003-01-01

    A series of circle flights have been carried out over the sea surface, using the EMIRAD L-band polarimetric radiometer. Motion compensation is applied, and polarimetric azimuth signatures are generated. Single tracks show geophysical noise, typically about 2 K, but averaging decreases the noise, ......, but a comparison of the signature to the downwelling galactic background radiation indicates, that the signature may not origin from the wind driven sea surface pattern....

  16. Utility of Characterizing and Monitoring Suspected Underground Nuclear Sites with VideoSAR

    Science.gov (United States)

    Dauphin, S. M.; Yocky, D. A.; Riley, R.; Calloway, T. M.; Wahl, D. E.

    2016-12-01

    Sandia National Laboratories proposed using airborne synthetic aperture RADAR (SAR) collected in VideoSAR mode to characterize the Underground Nuclear Explosion Signature Experiment (UNESE) test bed site at the Nevada National Security Site (NNSS). The SNL SAR collected airborne, Ku-band (16.8 GHz center frequency), 0.2032 meter ground resolution over NNSS in August 2014 and X-band (9.6 GHz), 0.1016 meter ground resolution fully-polarimetric SAR in April 2015. This paper reports the findings of processing and exploiting VideoSAR for creating digital elevation maps, detecting cultural artifacts and exploiting full-circle polarimetric signatures. VideoSAR collects a continuous circle of phase history data, therefore, imagery can be formed over the 360-degrees of the site. Since the Ku-band VideoSAR had two antennas suitable for interferometric digital elevation mapping (DEM), DEMs could be generated over numerous aspect angles, filling in holes created by targets with height by imaging from all sides. Also, since the X-band VideoSAR was fully-polarimetric, scattering signatures could be gleaned from all angles also. Both of these collections can be used to find man-made objects and changes in elevation that might indicate testing activities. VideoSAR provides a unique, coherent measure of ground objects allowing one to create accurate DEMS, locate man-made objects, and identify scattering signatures via polarimetric exploitation. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. The authors would like to thank the National Nuclear Security Administration, Defense Nuclear Nonproliferation Research and Development, for sponsoring this work. We would also like to thank the Underground Nuclear Explosion Signatures Experiment team, a multi

  17. Characterizing the detection module paving the ECLAIRs camera for the SVOM gamma-ray buts mission

    International Nuclear Information System (INIS)

    Nasser, Guillaume

    2015-01-01

    Gamma-ray bursts (GRBs) are short and very intense flashes of X-gamma-ray photons lasting from few milliseconds to hundreds of seconds appearing randomly over the sky. These cosmological events are thought to be due to the catastrophic formation of newly formed black holes following the collapse of some massive stars or after the coalescence of two compact objects and resulting in the launch of powerful ultra-relativistic jets orientated towards the Earth. The Sino-French mission SVOM (Space-based multi-band Variable Object Monitor) is dedicated to the study of these extreme and fascinating transient events and expected to be launched in 2020's. The satellite will implement a multi-wavelength science payload amongst which the core will be the large-field coded-mask camera ECLAIRs in charge of the detection and the localisation of GRBs in the 4-150 keV range. The ECLAIRs detection plane, DPIX, is made of 80x80 Schottky CdTe semi-conductor detectors and the front-end electronics. During my PhD, I mainly worked on the characterization of the scientific performance of the elementary detection modules called XRDPIX (i.e. a hybrid made of 8*4 detectors coupled with a low-noise ASIC) that will paved the DPIX. The main goal is then to derive the best suitable choice of the instrumental parameters in order to optimize the camera in-flight performance. In the manuscript, I discuss the methodology I used to explore the instrument parameter space. I describe the various testing protocols that I created and the different tests that I performed using several XRDPIX modules in a thermal-vacuum chamber and irradiated with radioactive sources. I discuss in detail the results and the various observables that I used to define the optimal in-flight operating zone of the detection plane. I also study the contribution of the different noise sources coming from the detectors and the electronic chain with a model I designed in order to control the quality of the hybridization process. I

  18. Biological and bacteriological characterization of the strain of Xylella fastidiosa Xf-PGAICR and detection of X. fastidiosa from leafhoppers

    International Nuclear Information System (INIS)

    Marin Chaves, Maria Priscilla

    2014-01-01

    Laboratory tools are developed and optimized for the biological characterization of a strain of Xylella fastidiosa (Xf-PGAICR) isolated of guava. The testing of pathogenesis robustly has allowed the characterization of other strains of X. fastidiosa. The detection of X. fastidiosa is carried out in their insect vectors to establish the relationship with the presence of phytopathogen in the vector, the presence and dissemination of X. fastidiosa to nearby areas [es

  19. Synthesis and characterization of rare earth molybdates nanoparticles for detection of specific prostatic cancer (PSA)

    International Nuclear Information System (INIS)

    Dias, Clarissa Lombardi

    2013-01-01

    The interest in using rare earths to investigate the properties and functions of biochemical systems as well as to determinate biological substances has increased in several fields, including biomarkers in immunology (fluoro immunoassays). Nowadays the use of lanthanides in the diagnosis of various diseases have become more important through the development of commercial diagnostic kits. As main feature, these rare earths can show a long lifetime, photo stability and emission bands of atomic like behavior and well defined, in the visible region, demonstrating unique advantages when compared to other luminescent species. The present work had as its goal to synthesize rare earth molybdates by the co-precipitation method as well as to characterize these materials by X-ray diffraction, near infrared spectroscopy, thermogravimetric analysis, scanning electronic microscopy, transmission electronic microscopy and luminescent studies. In this work, three different studied were developed: the influence of the vortex speed variation during co-precipitation in the structure of the final product, morphology and luminescence properties; the influence of the annealing temperature also in the structure, morphology and luminescence properties; and the influence of concentration of the doping in the luminescence properties. Another important step of this work was the functionalization of nanoparticles using an organosilane (APTES) to coat and establish points for binding the particles to biological species. It was proved that this process was very efficient by the characterization results and the silica incorporation was well succeeded. Specific prostatic cancer (PSA) was then linked to the functionalized nanoparticles to diagnostic prostatic cancer by fluoroimmunoassay and levels for detection were established. (author)

  20. Towards real-time topical detection and characterization of FDG dose infiltration prior to PET imaging

    International Nuclear Information System (INIS)

    Williams, Jason M.; Arlinghaus, Lori R.; Rani, Sudheer D.; Shone, Martha D.; Abramson, Vandana G.; Pendyala, Praveen; Chakravarthy, A.B.; Gorge, William J.; Knowland, Joshua G.; Lattanze, Ronald K.; Perrin, Steven R.; Scarantino, Charles W.; Townsend, David W.; Abramson, Richard G.; Yankeelov, Thomas E.

    2016-01-01

    To dynamically detect and characterize "1"8F-fluorodeoxyglucose (FDG) dose infiltrations and evaluate their effects on positron emission tomography (PET) standardized uptake values (SUV) at the injection site and in control tissue. Investigational gamma scintillation sensors were topically applied to patients with locally advanced breast cancer scheduled to undergo limited whole-body FDG-PET as part of an ongoing clinical study. Relative to the affected breast, sensors were placed on the contralateral injection arm and ipsilateral control arm during the resting uptake phase prior to each patient's PET scan. Time-activity curves (TACs) from the sensors were integrated at varying intervals (0-10, 0-20, 0-30, 0-40, and 30-40 min) post-FDG and the resulting areas under the curve (AUCs) were compared to SUVs obtained from PET. In cases of infiltration, observed in three sensor recordings (30 %), the injection arm TAC shape varied depending on the extent and severity of infiltration. In two of these cases, TAC characteristics suggested the infiltration was partially resolving prior to image acquisition, although it was still apparent on subsequent PET. Areas under the TAC 0-10 and 0-20 min post-FDG were significantly different in infiltrated versus non-infiltrated cases (Mann-Whitney, p < 0.05). When normalized to control, all TAC integration intervals from the injection arm were significantly correlated with SUV_p_e_a_k and SUV_m_a_x measured over the infiltration site (Spearman ρ ≥ 0.77, p < 0.05). Receiver operating characteristic (ROC) analyses, testing the ability of the first 10 min of post-FDG sensor data to predict infiltration visibility on the ensuing PET, yielded an area under the ROC curve of 0.92. Topical sensors applied near the injection site provide dynamic information from the time of FDG administration through the uptake period and may be useful in detecting infiltrations regardless of PET image field of view. This dynamic information may also

  1. Towards real-time topical detection and characterization of FDG dose infiltration prior to PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Jason M.; Arlinghaus, Lori R. [Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN (United States); Rani, Sudheer D. [Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN (United States); Vanderbilt University Medical Center, Department of Radiology and Radiological Sciences, Nashville, TN (United States); Shone, Martha D. [Vanderbilt University Medical Center, Department of Radiology and Radiological Sciences, Nashville, TN (United States); Abramson, Vandana G. [Vanderbilt University Medical Center, Department of Medicine, Nashville, TN (United States); Vanderbilt-Ingram Cancer Center, Nashville, TN (United States); Pendyala, Praveen [Vanderbilt University Medical Center, Department of Radiation Oncology, Nashville, TN (United States); Chakravarthy, A.B. [Vanderbilt-Ingram Cancer Center, Nashville, TN (United States); Vanderbilt University Medical Center, Department of Radiation Oncology, Nashville, TN (United States); Gorge, William J.; Knowland, Joshua G.; Lattanze, Ronald K.; Perrin, Steven R. [Lucerno Dynamics, LLC, Morrisville, NC (United States); Scarantino, Charles W. [Lucerno Dynamics, LLC, Morrisville, NC (United States); University of North Carolina, Department of Radiation Oncology, Chapel Hill, NC (United States); Townsend, David W. [Lucerno Dynamics, LLC, Morrisville, NC (United States); Technology and Research-National University of Singapore, Clinical Imaging Research Centre, Agency for Science, Singapore (Singapore); Abramson, Richard G. [Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN (United States); Vanderbilt University Medical Center, Department of Radiology and Radiological Sciences, Nashville, TN (United States); Vanderbilt-Ingram Cancer Center, Nashville, TN (United States); Yankeelov, Thomas E. [The University of Texas at Austin, Institute for Computational and Engineering Sciences, and Departments of Biomedical Engineering and Internal Medicine, Austin, TX (United States)

    2016-12-15

    To dynamically detect and characterize {sup 18}F-fluorodeoxyglucose (FDG) dose infiltrations and evaluate their effects on positron emission tomography (PET) standardized uptake values (SUV) at the injection site and in control tissue. Investigational gamma scintillation sensors were topically applied to patients with locally advanced breast cancer scheduled to undergo limited whole-body FDG-PET as part of an ongoing clinical study. Relative to the affected breast, sensors were placed on the contralateral injection arm and ipsilateral control arm during the resting uptake phase prior to each patient's PET scan. Time-activity curves (TACs) from the sensors were integrated at varying intervals (0-10, 0-20, 0-30, 0-40, and 30-40 min) post-FDG and the resulting areas under the curve (AUCs) were compared to SUVs obtained from PET. In cases of infiltration, observed in three sensor recordings (30 %), the injection arm TAC shape varied depending on the extent and severity of infiltration. In two of these cases, TAC characteristics suggested the infiltration was partially resolving prior to image acquisition, although it was still apparent on subsequent PET. Areas under the TAC 0-10 and 0-20 min post-FDG were significantly different in infiltrated versus non-infiltrated cases (Mann-Whitney, p < 0.05). When normalized to control, all TAC integration intervals from the injection arm were significantly correlated with SUV{sub peak} and SUV{sub max} measured over the infiltration site (Spearman ρ ≥ 0.77, p < 0.05). Receiver operating characteristic (ROC) analyses, testing the ability of the first 10 min of post-FDG sensor data to predict infiltration visibility on the ensuing PET, yielded an area under the ROC curve of 0.92. Topical sensors applied near the injection site provide dynamic information from the time of FDG administration through the uptake period and may be useful in detecting infiltrations regardless of PET image field of view. This dynamic information

  2. Synthesis and characterization of lanthanide based nanomaterials for radiation detection and biomedical applications

    Science.gov (United States)

    Yao, Mingzhen

    2011-12-01

    Lanthanide based nanomaterials have shown a great potential in various areas such as luminescence imaging, luminescent labels, and detection of cellular functions. Due to the f-f transitions of the metal ion, luminescence of lanthanide ions is characterized by sharp and narrow emissions. In this dissertation lanthanide based nanoparticles such as Ce3+, Eu3+ and other lanthanide ions doped LaF3 were synthesized, their characterization, encapsulation and embedding into hybrid matrix were investigated and some of their biomedical and radiological applications were studied. DMSO is a common solvent which has been used widely for biological applications. LaF3:Ce nanoparticles were synthesized in DMSO and it was found that their fluorescent emission originates from the metal-to-ligand charge-transfer excited states. After conjugation with PpIX and then encapsulation within PLGA, the particles show efficient uptake by cancer cells and great cytotoxicity, which is promising for applications in cancer treatments. However, the emission of Eu3+ in DMSO is totally different from LaF3:Ce, very strong characteristic luminescence is observed but no emissions from metal-to-ligand charge-transfer excited states as observed in LaF3:Ce in DMSO. Besides, it is very interesting to see that the coupling of Eu 3+ with O-H oscillations after water was introduced has an opposite effect on emission peaks at 617 nm and its shoulder peak at 613 nm. As a result, the intensity ratio of these two emissions has a nearly perfect linear dependence on increasing water concentration in Eu-DMSO, which provides a very convenient and valuable method for water determination in DMSO. Ce3+ has been well known as an emitter for radiation detection due to its very short decay lifetime. However, its emission range limited the environment in which the detection system works. Whereas, Quantum dots have high luminescence quantum efficiency but their low stopping power results in very weak scintillation

  3. Electromagnetic packable technology (EMPACT) for detection and characterization of ordnance in post-conflict areas

    Science.gov (United States)

    Schultz, Gregory; Miller, Jonathan; Keranen, Joe

    2013-06-01

    Land reclamation efforts in post-conflict regions are often hampered by the presence of Unexploded Ordnance (UXO) or other Explosive Remnants of War (ERW). Surface geophysical methods, such as Electromagnetic Induction (EMI) and magnetometry, are typically applied to screen rehabilitation areas for UXO prior to excavation; however, the prevalence of innocuous magnetic clutter related to indigenous scrap, fragmentation, or geology can severely impede the progress and efficiency of these remediation efforts. Additionally, the variability in surface conditions and local topography necessitates the development of sensor technologies that can be applied to a range of sites including those that prohibit the use of vehicle-mounted or large array systems. We present a man-portable EMI sensor known as the Electromagnetic Packable Technology (EMPACT) system that features a multi-axis sensor configuration in a compact form factor. The system is designed for operation in challenging site conditions and can be used in low ground-standoff modes to detect small and low-metal content objects. The EMPACT acquires high spatial density, multi-axis data that enable high resolution of small objects. This high density data can also be used to provide characterization of target physical features, such as size, material content, and shape. We summarize the development of this system for humanitarian demining operations and present results from preliminary system evaluations against a range of target types. Specifically, we assess the general detection capabilities of the EMPACT system and we evaluate the potential for target classification based on analysis of data and target model features.

  4. CHARACTERIZING THE YOUNGEST HERSCHEL-DETECTED PROTOSTARS. I. ENVELOPE STRUCTURE REVEALED BY CARMA DUST CONTINUUM OBSERVATIONS

    International Nuclear Information System (INIS)

    Tobin, John J.; Stutz, Amelia M.; Henning, Thomas; Ragan, Sarah E.; Megeath, S. Thomas; Fischer, William J.; Ali, Babar; Stanke, Thomas; Manoj, P.; Calvet, Nuria; Hartmann, Lee

    2015-01-01

    We present Combined Array for Research in Millimeter-wave Astronomy 2.9 mm dust continuum emission observations of a sample of 14 Herschel-detected Class 0 protostars in the Orion A and B molecular clouds, drawn from the PACS Bright Red Sources (PBRS) sample. These objects are characterized by very red 24-70 μm colors and prominent submillimeter emission, suggesting that they are very young Class 0 protostars embedded in dense envelopes. We detect all of the PBRS in 2.9 mm continuum emission and emission from four protostars and one starless core in the fields toward the PBRS; we also report one new PBRS source. The ratio of 2.9 mm luminosity to bolometric luminosity is higher by a factor of ∼5 on average, compared to other well-studied protostars in the Perseus and Ophiuchus clouds. The 2.9 mm visibility amplitudes for 6 of the 14 PBRS are very flat as a function of uv distance, with more than 50% of the source emission arising from radii <1500 AU. These flat visibility amplitudes are most consistent with spherically symmetric envelope density profiles with ρ ∝ R –2.5 . Alternatively, there could be a massive unresolved structure like a disk or a high-density inner envelope departing from a smooth power law. The large amount of mass on scales <1500 AU (implying high average central densities) leads us to suggest that that the PBRS with flat visibility amplitude profiles are the youngest PBRS and may be undergoing a brief phase of high mass infall/accretion and are possibly among the youngest Class 0 protostars. The PBRS with more rapidly declining visibility amplitudes still have large envelope masses, but could be slightly more evolved

  5. Characterizing the malaria rural-to-urban transmission interface: The importance of reactive case detection.

    Directory of Open Access Journals (Sweden)

    Karen Molina Gómez

    2017-07-01

    Full Text Available Reported urban malaria cases are increasing in Latin America, however, evidence of such trend remains insufficient. Here, we propose an integrated approach that allows characterizing malaria transmission at the rural-to-urban interface by combining epidemiological, entomological, and parasite genotyping methods.A descriptive study that combines active (ACD, passive (PCD, and reactive (RCD case detection was performed in urban and peri-urban neighborhoods of Quibdó, Colombia. Heads of households were interviewed and epidemiological surveys were conducted to assess malaria prevalence and identify potential risk factors. Sixteen primary cases, eight by ACD and eight by PCD were recruited for RCD. Using the RCD strategy, prevalence of 1% by microscopy (6/604 and 9% by quantitative polymerase chain reaction (qPCR (52/604 were found. A total of 73 houses and 289 volunteers were screened leading to 41 secondary cases, all of them in peri-urban settings (14% prevalence. Most secondary cases were genetically distinct from primary cases indicating that there were independent occurrences. Plasmodium vivax was the predominant species (76.3%, 71/93, most of them being asymptomatic (46/71. Urban and peri-urban neighborhoods had significant sociodemographic differences. Twenty-four potential breeding sites were identified, all in peri-urban areas. The predominant vectors for 1,305 adults were Anopheles nuneztovari (56,2% and An. Darlingi (42,5%. One An. nuneztovari specimen was confirmed naturally infected with P. falciparum by ELISA.This study found no evidence supporting the existence of urban malaria transmission in Quibdó. RCD strategy was more efficient for identifying malaria cases than ACD alone in areas where malaria transmission is variable and unstable. Incorporating parasite genotyping allows discovering hidden patterns of malaria transmission that cannot be detected otherwise. We propose to use the term "focal case" for those primary cases that

  6. Detection & characterization of necrotoxin producing Escherichia coli (NTEC) from patients with urinary tract infection (UTI).

    Science.gov (United States)

    Rahman, Helina; Deka, Manab

    2014-04-01

    Urinary tract infections (UTI) are a serious health problem affecting millions of people each year. Although appreciable work on various aspects of UTI including aetiology per se has been done, information on the emerging pathogens like necrotoxigenic Escherichia coli (NTEC) is largely lacking in India. In the present study E. coli isolates from patients with urinary tract infection from northeastern India were investigated for detection and characterization of NTEC. E. coli isolated and identified from urine samples of patients with UTI were serotyped. Antibiogram was determined by disc diffusion test. Plasmid profile was also determined. Virulence genes of NTEC (cnf1, cnf2, pap, aer, sfa, hly, afa) were detected by PCR assay. E.coli isolates carrying cnf gene (s) were identified as NTEC. A total of 550 E. coli were isolated and tested for the presence of cnf genes. Of these, 84 (15.27%) belonged to NTEC. The cnf1 gene was present in 52 (61.9%) isolates, cnf2 in 23 (27.4%) and 9 (10.7%) carried both cnf1 and cnf2 genes. All the NTEC strains were found to harbour the pap and aer genes. Serogroup O4 was found to be the most common among the 12 serogroups identified amongst the NTEC isolates. Majority of the isolates (96.4%) were sensitive to furazolidone and were highly resistant to ampicillin. NTEC were found to harbour different numbers of plasmids (1 to 7). No association was observed between the number of plasmids and the antibiotic resistance of the isolates. The results of the present study showed that about 15 per cent of E. coli isolates associated with UTI belonged to NTEC. More studies need to be done from other parts of the country.

  7. Photo-polarimetric sensitivities to layering and mixing of absorbing aerosols

    Directory of Open Access Journals (Sweden)

    O. V. Kalashnikova

    2011-09-01

    Full Text Available We investigate to what extent multi-angle polarimetric measurements are sensitive to vertical mixing/layering of absorbing aerosols, adopting calibration uncertainty of 1.5% in intensity and 0.5% in the degree of linear polarization of Multiangle Spectro-Polarimetric Imager (MSPI. Employing both deterministic and Monte Carlo radiative transfer codes with polarization, we conduct modeling experiments to determine how the measured Stokes vector elements are affected at UV and short visible wavelengths by the vertical distribution, mixing and layering of smoke and dust aerosols for variety of microphysical parameters. We find that multi-angular polarimetry holds the potential to infer dust-layer heights and thicknesses at blue visible channel due to its lesser sensitivity to changes in dust coarse mode optical properties, but higher sensitivity to the dust vertical profiles. Our studies quantify requirements for obtaining simultaneous information on aerosol layer height and absorption under MSPI measurement uncertainties.

  8. Relative astrometry of compact flaring structures in Sgr A* with polarimetric very long baseline interferometry

    International Nuclear Information System (INIS)

    Johnson, Michael D.; Doeleman, Sheperd S.; Fish, Vincent L.; Broderick, Avery E.; Wardle, John F. C.; Marrone, Daniel P.

    2014-01-01

    We demonstrate that polarimetric interferometry can be used to extract precise spatial information about compact polarized flares of Sgr A*. We show that, for a faint dynamical component, a single interferometric baseline suffices to determine both its polarization and projected displacement from the quiescent intensity centroid. A second baseline enables two-dimensional reconstruction of the displacement, and additional baselines can self-calibrate using the flare, enhancing synthesis imaging of the quiescent emission. We apply this technique to simulated 1.3 mm wavelength observations of a 'hot spot' embedded in a radiatively inefficient accretion disk around Sgr A*. Our results indicate that, even with current sensitivities, polarimetric interferometry with the Event Horizon Telescope can achieve ∼5 μas relative astrometry of compact flaring structures near Sgr A* on timescales of minutes.

  9. Investigation of the Capability of Compact Polarimetric SAR Interferometry to Estimate Forest Height

    Science.gov (United States)

    Zhang, Hong; Xie, Lei; Wang, Chao; Chen, Jiehong

    2013-08-01

    The main objective of this paper is to investigate the capability of compact Polarimetric SAR Interferometry (C-PolInSAR) on forest height estimation. For this, the pseudo fully polarimetric interferomteric (F-PolInSAR) covariance matrix is firstly reconstructed, then the three- stage inversion algorithm, hybrid algorithm, Music and Capon algorithm are applied to both C-PolInSAR covariance matrix and pseudo F-PolInSAR covariance matrix. The availability of forest height estimation is demonstrated using L-band data generated by simulator PolSARProSim and X-band airborne data acquired by East China Research Institute of Electronic Engineering, China Electronics Technology Group Corporation.

  10. Programmable liquid crystal waveplate polarization gratings as elements for polarimetric and interference applications

    Science.gov (United States)

    Moreno, I.; Davis, J. A.

    2010-06-01

    We review the use of a parallel aligned nematic liquid crystal spatial light modulator as a very useful and flexible device for polarimetric and interferometric applications. The device acts as a programmable pixelated waveplate, and the encoding of a linear grating permits its use as a polarization beam splitter. When a grating with a reduced period is encoded, the diffracted beams are spatially separated and the device can be used for polarimetric analysis. On the contrary when a large period grating is displayed, the beams are not spatially separated, and they are useful to realize a common path interferometric system with polarization sensitivity. The flexibility offered by the programmability of the display allows non-conventional uses, including the analysis of light beams with structured spatial polarizations.

  11. Laboratory characterization and astrophysical detection of vibrationally excited states of vinyl cyanide in Orion-KL

    Science.gov (United States)

    López, A.; Tercero, B.; Kisiel, Z.; Daly, A. M.; Bermúdez, C.; Calcutt, H.; Marcelino, N.; Viti, S.; Drouin, B. J.; Medvedev, I. R.; Neese, C. F.; Pszczółkowski, L.; Alonso, J. L.; Cernicharo, J.

    2014-12-01

    Context. We perform a laboratory characterization in the 18-1893 GHz range and astronomical detection between 80-280 GHz in Orion-KL with IRAM-30 m of CH2CHCN (vinyl cyanide) in its ground and vibrationally excited states. Aims: Our aim is to improve the understanding of rotational spectra of vibrationally excited vinyl cyanide with new laboratory data and analysis. The laboratory results allow searching for these excited state transitions in the Orion-KL line survey. Furthermore, rotational lines of CH2CHCN contribute to the understanding of the physical and chemical properties of the cloud. Methods: Laboratory measurements of CH2CHCN made on several different frequency-modulated spectrometers were combined into a single broadband 50-1900 GHz spectrum and its assignment was confirmed by Stark modulation spectra recorded in the 18-40 GHz region and by ab-initio anharmonic force field calculations. For analyzing the emission lines of vinyl cyanide detected in Orion-KL we used the excitation and radiative transfer code (MADEX) at LTE conditions. Results: Detailed characterization of laboratory spectra of CH2CHCN in nine different excited vibrational states: ν11 = 1, ν15 = 1, ν11 = 2, ν10 = 1 ⇔ (ν11 = 1,ν15 = 1), ν11 = 3/ν15 = 2/ν14 = 1, (ν11 = 1,ν10 = 1) ⇔ (ν11 = 2,ν15 = 1), ν9 = 1, (ν11 = 1,ν15 = 2) ⇔ (ν10 = 1,ν15 = 1) ⇔ (ν11 = 1,ν14 = 1), and ν11 = 4 are determined, as well as the detection of transitions in the ν11 = 2 and ν11 = 3 states for the first time in Orion-KL and of those in the ν10 = 1 ⇔ (ν11 = 1,ν15 = 1) dyad of states for the first time in space. The rotational transitions of the ground state of this molecule emerge from four cloud components of hot core nature, which trace the physical and chemical conditions of high mass star forming regions in the Orion-KL Nebula. The lowest energy vibrationally excited states of vinyl cyanide, such as ν11 = 1 (at 328.5 K), ν15 = 1 (at 478.6 K), ν11 = 2 (at 657.8 K), the ν10

  12. Quantitative Estimation of Above Ground Crop Biomass using Ground-based, Airborne and Spaceborne Low Frequency Polarimetric Synthetic Aperture Radar

    Science.gov (United States)

    Koyama, C.; Watanabe, M.; Shimada, M.

    2016-12-01

    Estimation of crop biomass is one of the important challenges in environmental remote sensing related to agricultural as well as hydrological and meteorological applications. Usually passive optical data (photographs, spectral data) operating in the visible and near-infrared bands is used for such purposes. The virtue of optical remote sensing for yield estimation, however, is rather limited as the visible light can only provide information about the chemical characteristics of the canopy surface. Low frequency microwave signals with wavelength longer 20 cm have the potential to penetrate through the canopy and provide information about the whole vertical structure of vegetation from the top of the canopy down to the very soil surface. This phenomenon has been well known and exploited to detect targets under vegetation in the military radar application known as FOPEN (foliage penetration). With the availability of polarimetric interferometric SAR data the use PolInSAR techniques to retrieve vertical vegetation structures has become an attractive tool. However, PolInSAR is still highly experimental and suitable data is not yet widely available. In this study we focus on the use of operational dual-polarization L-band (1.27 GHz) SAR which is since the launch of Japan's Advanced Land Observing Satellite (ALOS, 2006-2011) available worldwide. Since 2014 ALOS-2 continues to deliver such kind of partial polarimetric data for the entire land surface. In addition to these spaceborne data sets we use airborne L-band SAR data acquired by the Japanese Pi-SAR-L2 as well as ultra-wideband (UWB) ground based SAR data operating in the frequency range from 1-4 GHz. By exploiting the complex dual-polarization [C2] Covariance matrix information, the scattering contributions from the canopy can be well separated from the ground reflections allowing for the establishment of semi-empirical relationships between measured radar reflectivity and the amount of fresh-weight above

  13. A Radarsat-2 Polarimetric Analysis Over The UNESCO Site In Danger Of Samarra (Iraq)

    Science.gov (United States)

    Dore, Nicole; Patruno, Jolanda; Pottier, Eric; Crespi, Mattia

    2013-04-01

    This work has as goal the detection of archaeological probable buried remains and the monitoring of the external ones. The archaeological site taken into account for this purpose is the area of the ancient octagonal city of al-Qadisiyya funded by Harun al-Rashid. This city, located in the southern part of the Samarra territory, was abandoned unfinished when the caliph moved to Raqqa (Syria) in 796 A.D. Bigness of the structures, unstable political situation and agricultural expansion threats, that let the city of Samarra be inscribed in the UNESO list of sites in danger since 2007, gave us a reason more to investigate this area. The study was carried out with four fine quad-pol imagery of the Canadian satellite RADARSAT-2, launched in December 2007. However C-band lower capability of penetration compared to ALOS PALSAR L-band, the choice of this satellite is due to its higher spatial resolution compared to the PALSAR one. Thanks to the higher spatial resolution and the location of the site in a semi desert area, we succeeded in balancing a probable lower waves penetration. Our analysis focused on four polarimetric images, two with a 23° incidence angle and two with a 45° incidence angle, acquired in different moments of the year 2012. The difference between the angles was motivated, respectively, by the possibility of a higher penetration of the microwaves in the ground and by the higher possibility of double bounce response in the case of presence of buried structures. The time spacing, on the other hand, allowed a temporal analysis over different months of the same year accompanied by meteorological condition available on the web for the zone. This type of analysis, however, allowed the identification of the qanāt (the underground channel present in the northern part of the octagonal city of al-Qadisiyya) and other structures, thanks to differences visible in all the products. The potentiality of this SAR research for archaeology is well known, in particular

  14. Monitoring flooding and vegetation on seasonally inundated floodplains with multifrequency polarimetric synthetic aperture radar

    Science.gov (United States)

    Hess, Laura Lorraine

    The ability of synthetic aperture radar to detect flooding and vegetation structure was evaluated for three seasonally inundated floodplain sites supporting a broad variety of wetland and upland vegetation types: two reaches of the Solimoes floodplain in the central Amazon, and the Magela Creek floodplain in Northern Territory, Australia. For each site, C- and L-band polarimetric Shuttle Imaging Radar-C (SIR-C) data was obtained at both high- and low-water stages. Inundation status and vegetation structure were documented simultaneous with the SIR-C acquisitions using low-altitude videography and ground measurements. SIR-C images were classified into cover states defined by vegetation physiognomy and presence of standing water, using a decision-tree model with backscattering coefficients at HH, VV, and HV polarizations as input variables. Classification accuracy was assessed using user's accuracy, producer's accuracy, and kappa coefficient for a test population of pixels. At all sites, both C- and L-band were necessary to accurately classify cover types with two dates. HH polarization was most. useful for distinguishing flooded from non-flooded vegetation (C-HH for macrophyte versus pasture, L-HH for flooded versus non-flooded forest), and cross-polarized L-band data provided the best separation between woody and non-woody vegetation. Increases in L-HH backscattering due to flooding were on the order of 3--4 dB for closed-canopy varzea and igapo forest, and 4--7 dB, for open Melaleuca woodland. The broad range of physiognomies and stand structures found in both herbaceous and woody wetland communities, combined with the variation in the amount of emergent canopy caused by water level fluctuations and phenologic changes, resulted in a large range in backscattering characteristics of wetland communities both within and between sites. High accuracies cannot be achieved for these communities using single-date, single-band, single-polarization data, particularly in the

  15. Investigation of hydrometeor classification uncertainties through the POLARRIS polarimetric radar simulator

    Science.gov (United States)

    Dolan, B.; Rutledge, S. A.; Barnum, J. I.; Matsui, T.; Tao, W. K.; Iguchi, T.

    2017-12-01

    POLarimetric Radar Retrieval and Instrument Simulator (POLARRIS) is a framework that has been developed to simulate radar observations from cloud resolving model (CRM) output and subject model data and observations to the same retrievals, analysis and visualization. This framework not only enables validation of bulk microphysical model simulated properties, but also offers an opportunity to study the uncertainties associated with retrievals such as hydrometeor classification (HID). For the CSU HID, membership beta functions (MBFs) are built using a set of simulations with realistic microphysical assumptions about axis ratio, density, canting angles, size distributions for each of ten hydrometeor species. These assumptions are tested using POLARRIS to understand their influence on the resulting simulated polarimetric data and final HID classification. Several of these parameters (density, size distributions) are set by the model microphysics, and therefore the specific assumptions of axis ratio and canting angle are carefully studied. Through these sensitivity studies, we hope to be able to provide uncertainties in retrieved polarimetric variables and HID as applied to CRM output. HID retrievals assign a classification to each point by determining the highest score, thereby identifying the dominant hydrometeor type within a volume. However, in nature, there is rarely just one a single hydrometeor type at a particular point. Models allow for mixing ratios of different hydrometeors within a grid point. We use the mixing ratios from CRM output in concert with the HID scores and classifications to understand how the HID algorithm can provide information about mixtures within a volume, as well as calculate a confidence in the classifications. We leverage the POLARRIS framework to additionally probe radar wavelength differences toward the possibility of a multi-wavelength HID which could utilize the strengths of different wavelengths to improve HID classifications. With

  16. Agricultural Monitoring in Northeastern Ontario, Canada, Using Multi-Temporal Polarimetric RADARSAT-2 Data

    Directory of Open Access Journals (Sweden)

    Jeffrey W. Cable

    2014-03-01

    Full Text Available The purpose of this research is to analyze how changes in acquisition time and incidence angle affect various C-band synthetic aperture radar (SAR polarimetric intensities, co-polarized phase information, polarimetric response plots and decomposition parameters for various crops typical of Northern Ontario, Canada. We examine how these parameters may be used to monitor the growth stages of five common cash crops, namely, barley (Hordeum vulgare, canola (Brassica napus, oat (Avena sativa, soybean (Glycine max and wheat (Triticum spp.. In total, nine RADARSAT-2 polarimetric images were analyzed across a 14-week period beginning in June and ending in September 2011 using two incidence angles of approximately 26° and 41°. As expected, the backscatter intensities for all targets were found to show a higher response when acquired at the steeper incidence angle (26°. All cash crop targets showed a rise and fall in backscatter response over the course of the growing season, coinciding with changing growth stages. Slight phase differences were observed for cereal crops, possibly due to one of the polarizations penetrating between the rows allowing double-bounce to occur. The polarimetric response plots and decompositions offered insight into the scattering mechanisms of each crop type, generally showing an increase in volume scattering as the crops reached maturity. Specifically, the contributions of the crops increased towards the volume scattering component and zones 4 and 2, as the crops matured in regards to the Freeman-Durden and Cloude-Pottier decompositions respectively. Overall, soybean and canola showed a more similar response in comparison to the cereal cash crops. Although the study focused on Northern Ontario, it is anticipated that these results would be relevant in investigations of multi-temporal RADARSAT-2 for agricultural zones with similar crop types.

  17. STUDY ON THE CLASSIFICATION OF GAOFEN-3 POLARIMETRIC SAR IMAGES USING DEEP NEURAL NETWORK

    Directory of Open Access Journals (Sweden)

    J. Zhang

    2018-04-01

    Full Text Available Polarimetric Synthetic Aperture Radar(POLSAR) imaging principle determines that the image quality will be affected by speckle noise. So the recognition accuracy of traditional image classification methods will be reduced by the effect of this interference. Since the date of submission, Deep Convolutional Neural Network impacts on the traditional image processing methods and brings the field of computer vision to a new stage with the advantages of a strong ability to learn deep features and excellent ability to fit large datasets. Based on the basic characteristics of polarimetric SAR images, the paper studied the types of the surface cover by using the method of Deep Learning. We used the fully polarimetric SAR features of different scales to fuse RGB images to the GoogLeNet model based on convolution neural network Iterative training, and then use the trained model to test the classification of data validation.First of all, referring to the optical image, we mark the surface coverage type of GF-3 POLSAR image with 8m resolution, and then collect the samples according to different categories. To meet the GoogLeNet model requirements of 256 × 256 pixel image input and taking into account the lack of full-resolution SAR resolution, the original image should be pre-processed in the process of resampling. In this paper, POLSAR image slice samples of different scales with sampling intervals of 2 m and 1 m to be trained separately and validated by the verification dataset. Among them, the training accuracy of GoogLeNet model trained with resampled 2-m polarimetric SAR image is 94.89 %, and that of the trained SAR image with resampled 1 m is 92.65 %.

  18. Object-oriented crop mapping and monitoring using multi-temporal polarimetric RADARSAT-2 data

    Science.gov (United States)

    Jiao, Xianfeng; Kovacs, John M.; Shang, Jiali; McNairn, Heather; Walters, Dan; Ma, Baoluo; Geng, Xiaoyuan

    2014-10-01

    The aim of this paper is to assess the accuracy of an object-oriented classification of polarimetric Synthetic Aperture Radar (PolSAR) data to map and monitor crops using 19 RADARSAT-2 fine beam polarimetric (FQ) images of an agricultural area in North-eastern Ontario, Canada. Polarimetric images and field data were acquired during the 2011 and 2012 growing seasons. The classification and field data collection focused on the main crop types grown in the region, which include: wheat, oat, soybean, canola and forage. The polarimetric parameters were extracted with PolSAR analysis using both the Cloude-Pottier and Freeman-Durden decompositions. The object-oriented classification, with a single date of PolSAR data, was able to classify all five crop types with an accuracy of 95% and Kappa of 0.93; a 6% improvement in comparison with linear-polarization only classification. However, the time of acquisition is crucial. The larger biomass crops of canola and soybean were most accurately mapped, whereas the identification of oat and wheat were more variable. The multi-temporal data using the Cloude-Pottier decomposition parameters provided the best classification accuracy compared to the linear polarizations and the Freeman-Durden decomposition parameters. In general, the object-oriented classifications were able to accurately map crop types by reducing the noise inherent in the SAR data. Furthermore, using the crop classification maps we were able to monitor crop growth stage based on a trend analysis of the radar response. Based on field data from canola crops, there was a strong relationship between the phenological growth stage based on the BBCH scale, and the HV backscatter and entropy.

  19. Study on the Classification of GAOFEN-3 Polarimetric SAR Images Using Deep Neural Network

    Science.gov (United States)

    Zhang, J.; Zhang, J.; Zhao, Z.

    2018-04-01

    Polarimetric Synthetic Aperture Radar (POLSAR) imaging principle determines that the image quality will be affected by speckle noise. So the recognition accuracy of traditional image classification methods will be reduced by the effect of this interference. Since the date of submission, Deep Convolutional Neural Network impacts on the traditional image processing methods and brings the field of computer vision to a new stage with the advantages of a strong ability to learn deep features and excellent ability to fit large datasets. Based on the basic characteristics of polarimetric SAR images, the paper studied the types of the surface cover by using the method of Deep Learning. We used the fully polarimetric SAR features of different scales to fuse RGB images to the GoogLeNet model based on convolution neural network Iterative training, and then use the trained model to test the classification of data validation.First of all, referring to the optical image, we mark the surface coverage type of GF-3 POLSAR image with 8m resolution, and then collect the samples according to different categories. To meet the GoogLeNet model requirements of 256 × 256 pixel image input and taking into account the lack of full-resolution SAR resolution, the original image should be pre-processed in the process of resampling. In this paper, POLSAR image slice samples of different scales with sampling intervals of 2 m and 1 m to be trained separately and validated by the verification dataset. Among them, the training accuracy of GoogLeNet model trained with resampled 2-m polarimetric SAR image is 94.89 %, and that of the trained SAR image with resampled 1 m is 92.65 %.

  20. A near-infrared, optical, and ultraviolet polarimetric and timing investigation of complex equatorial dusty structures

    Science.gov (United States)

    Marin, F.; Rojas Lobos, P. A.; Hameury, J. M.; Goosmann, R. W.

    2018-05-01

    Context. From stars to active galactic nuclei, many astrophysical systems are surrounded by an equatorial distribution of dusty material that is, in a number of cases, spatially unresolved even with cutting edge facilities. Aims: In this paper, we investigate if and how one can determine the unresolved and heterogeneous morphology of dust distribution around a central bright source using time-resolved polarimetric observations. Methods: We used polarized radiative transfer simulations to study a sample of circumnuclear dusty morphologies. We explored a grid of geometrically variable models that are uniform, fragmented, and density stratified in the near-infrared, optical, and ultraviolet bands, and we present their distinctive time-dependent polarimetric signatures. Results: As expected, varying the structure of the obscuring equatorial disk has a deep impact on the inclination-dependent flux, polarization degree and angle, and time lags we observe. We find that stratified media are distinguishable by time-resolved polarimetric observations, and that the expected polarization is much higher in the infrared band than in the ultraviolet. However, because of the physical scales imposed by dust sublimation, the average time lags of months to years between the total and polarized fluxes are important; these time lags lengthens the observational campaigns necessary to break more sophisticated, and therefore also more degenerated, models. In the ultraviolet band, time lags are slightly shorter than in the infrared or optical bands, and, coupled to lower diluting starlight fluxes, time-resolved polarimetry in the UV appears more promising for future campaigns. Conclusions: Equatorial dusty disks differ in terms of inclination-dependent photometric, polarimetric, and timing observables, but only the coupling of these different markers can lead to inclination-independent constraints on the unresolved structures. Even though it is complex and time consuming, polarized

  1. Design and fabrication of a bidimentional microbolometer array for Terahertz detection characterized at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Orduna-Diaz, A [CIBA-Tlaxcala, IPN, Tlaxcala, Tlax.(Mexico); Castillo-DomInguez, E; Torres-Jacome, A; De la Hidalga-Wade, F J; Trevino-Palacios, C G, E-mail: abdu@inaoep.mx [Instituto Nacional de Astrofisica, Optica y Electronica, Apdo. Postal 51 y 216, Puebla, Pue. 72000 (Mexico)

    2011-01-01

    We present the design, micromachining and characterization of a bidimentional bolometer array for radiation detection in the 0.7-1.5 THz frequency range. The detector is based on a boron doped amorphous silicon film (a-Si-B:H). The film optimized for sensitivity enhancement was obtained using 500 sccm diborane flow with 95 nm thickness. The sensing layer was deposited using plasma enhanced chemical vapor deposition (PECVD) technique at low frequency on a 0.45 {mu}m thick silicon nitride membrane sustained by a micromachined frame in crystalline silicon. The design consists of four 5x5 bolometer arrays made by conventional lithography. The bolometer active area is 660 {mu}m x 420 {mu}m and the detector will operate as a focal plane array. The current-voltage characteristics present an ohmic behaviour; the temperature coefficient of resistance (TCR) was obtained by measuring the bolometer performance from room temperature down to liquid nitrogen temperature. The responsivity was measured under illumination from a black body radiating at 300, 500, 700, 900 and 1100 deg. C, obtaining a value of R =1.17 x 10{sup -2} A/W with a dark current of 4.43 x 10{sup -9} A

  2. The SOS chromotest: bacterial cells to detect and characterize genotoxic products and radiations

    International Nuclear Information System (INIS)

    Quillardet, P.; Hofnung, M.

    1994-01-01

    The advanced knowledge we have on the bacterium Escherichia coli has facilitated the development of the colorimetric and fast assay, the SOS chromotest, which involves a single tester strain and gives a qualitative and a quantitative assay of the action of a genotoxic agent. We discuss a number of possibilities opened by this test in order to make a genetic diagnosis of the chemical nature of the damages caused in the genetic material by means of a battery of strains which have been genetically modified for that purpose. In order to give an idea of the accuracy of the bacterial responses and of the way they can be used to characterize the DNA damage by a genetic approach, the case of alkylating agents is described in a relatively detailed fashion, and the case of oxidative agents is rapidly mentioned. The sensitivity to ionizing radiation is such that the test is able to detect doses of the order of 1 Gy. We discuss briefly how it could be possible to increase this sensitivity by genetically inactivating repair systems which process the injuries caused by these agents, and how the use of a battery of tester strains could also give information on the nature of injuries caused by various types of ionizing radiation. (authors). 39 refs. 4 figs. 1 tab

  3. Characterizing a four-qubit planar lattice for arbitrary error detection

    Science.gov (United States)

    Chow, Jerry M.; Srinivasan, Srikanth J.; Magesan, Easwar; Córcoles, A. D.; Abraham, David W.; Gambetta, Jay M.; Steffen, Matthias

    2015-05-01

    Quantum error correction will be a necessary component towards realizing scalable quantum computers with physical qubits. Theoretically, it is possible to perform arbitrarily long computations if the error rate is below a threshold value. The two-dimensional surface code permits relatively high fault-tolerant thresholds at the ~1% level, and only requires a latticed network of qubits with nearest-neighbor interactions. Superconducting qubits have continued to steadily improve in coherence, gate, and readout fidelities, to become a leading candidate for implementation into larger quantum networks. Here we describe characterization experiments and calibration of a system of four superconducting qubits arranged in a planar lattice, amenable to the surface code. Insights into the particular qubit design and comparison between simulated parameters and experimentally determined parameters are given. Single- and two-qubit gate tune-up procedures are described and results for simultaneously benchmarking pairs of two-qubit gates are given. All controls are eventually used for an arbitrary error detection protocol described in separate work [Corcoles et al., Nature Communications, 6, 2015].

  4. Analytical characterization of heparin by capillary zone electrophoresis with conductivity detection and polymeric buffer additives.

    Science.gov (United States)

    Mikus, Peter; Valásková, Iva; Havránek, Emil

    2004-11-15

    A capillary zone electrophoresis (CZE) method for the analytical characterization of intact (high-molecular-weight) heparin was developed. For the first time, a hydrodynamically closed CZE separation system with conductivity detector was used for the separation, detection and quantitation of this highly sulfated, linear polysaccharide. Glycine (25mM) adjusted to pH 9.0 by bis-Tris-propane served as the running electrolyte system. Polymeric additives, polyvinylpyrrolidone (PVP), dextran (DEX), were used to improve the separation selectivity as they strongly retarded the heparin macromolecule while they did not practically influence comigrating inorganic anions. The proposed electrophoretic method was successfully validated. It was convenient for the sensitive, simple, rapid and reproducible assay of heparin in raw materials and isotonic saline. Here, the use of the conductivity detector was advantageous as it allowed heparin to be analyzed without a sample pretreatment. The CZE method should be an alternative to the pharmacopoeial conventional gel electrophoresis having used in the quality control of heparin so far. In addition, it should be convenient to quantitative estimation of heparin present in a preparation used, e.g., as the chiral selector in CE separations.

  5. Characterization of Antimicrobial Resistance Patterns and Detection of Virulence Genes in Campylobacter Isolates in Italy

    Science.gov (United States)

    Di Giannatale, Elisabetta; Di Serafino, Gabriella; Zilli, Katiuscia; Alessiani, Alessandra; Sacchini, Lorena; Garofolo, Giuliano; Aprea, Giuseppe; Marotta, Francesca

    2014-01-01

    Campylobacter has developed resistance to several antimicrobial agents over the years, including macrolides, quinolones and fluoroquinolones, becoming a significant public health hazard. A total of 145 strains derived from raw milk, chicken faeces, chicken carcasses, cattle faeces and human faeces collected from various Italian regions, were screened for antimicrobial susceptibility, molecular characterization (SmaI pulsed-field gel electrophoresis) and detection of virulence genes (sequencing and DNA microarray analysis). The prevalence of C. jejuni and C. coli was 62.75% and 37.24% respectively. Antimicrobial susceptibility revealed a high level of resistance for ciprofloxacin (62.76%), tetracycline (55.86%) and nalidixic acid (55.17%). Genotyping of Campylobacter isolates using PFGE revealed a total of 86 unique SmaI patterns. Virulence gene profiles were determined using a new microbial diagnostic microarray composed of 70-mer oligonucleotide probes targeting genes implicated in Campylobacter pathogenicity. Correspondence between PFGE and microarray clusters was observed. Comparisons of PFGE and virulence profiles reflected the high genetic diversity of the strains examined, leading us to speculate different degrees of pathogenicity inside Campylobacter populations. PMID:24556669

  6. Real-time detection and characterization of nuclear explosion using broadband analyses of regional seismic stations

    Science.gov (United States)

    Prastowo, T.; Madlazim

    2018-01-01

    This preliminary study aims to propose a new method of real-time detection and characterization of nuclear explosions by analyzing broadband seismic waveforms acquired from a network of regional seismic stations. Signal identification generated by a nuclear test was differentiated from natural sources of either earthquakes or other natural seismo-tectonic events by verifying crucial parameters, namely source depth, type of first motion, and P-wave domination of the broadband seismic wavesunder consideration. We examined and analyzed a recently hypothetical nuclear test performed by the North Koreangovernment that occurred on September 3, 2017 as a vital point to study. From spectral analyses, we found that the source of corresponding signals associated with detonations of the latest underground nuclear test was at a much shallower depth below the surface relatively compared with that of natural earthquakes, the suspected nuclear explosions produced compressional waves with radially directed outward from the source for their first motions, and the waves were only dominated by P-components. The results are then discussed in the context of potential uses of the proposed methodology for human-induced disaster early warning system and/or the need of rapid response purposes for minimizing the disaster risks.

  7. IMPROVED SEARCH OF PRINCIPAL COMPONENT ANALYSIS DATABASES FOR SPECTRO-POLARIMETRIC INVERSION

    International Nuclear Information System (INIS)

    Casini, R.; Lites, B. W.; Ramos, A. Asensio; Ariste, A. López

    2013-01-01

    We describe a simple technique for the acceleration of spectro-polarimetric inversions based on principal component analysis (PCA) of Stokes profiles. This technique involves the indexing of the database models based on the sign of the projections (PCA coefficients) of the first few relevant orders of principal components of the four Stokes parameters. In this way, each model in the database can be attributed a distinctive binary number of 2 4n bits, where n is the number of PCA orders used for the indexing. Each of these binary numbers (indices) identifies a group of ''compatible'' models for the inversion of a given set of observed Stokes profiles sharing the same index. The complete set of the binary numbers so constructed evidently determines a partition of the database. The search of the database for the PCA inversion of spectro-polarimetric data can profit greatly from this indexing. In practical cases it becomes possible to approach the ideal acceleration factor of 2 4n as compared to the systematic search of a non-indexed database for a traditional PCA inversion. This indexing method relies on the existence of a physical meaning in the sign of the PCA coefficients of a model. For this reason, the presence of model ambiguities and of spectro-polarimetric noise in the observations limits in practice the number n of relevant PCA orders that can be used for the indexing

  8. Polarimetric and angular light-scattering from dense media: Comparison of a vectorial radiative transfer model with analytical, stochastic and experimental approaches

    International Nuclear Information System (INIS)

    Riviere, Nicolas; Ceolato, Romain; Hespel, Laurent

    2013-01-01

    Our work presents computations via a vectorial radiative transfer model of the polarimetric and angular light scattered by a stratified dense medium with small and intermediate optical thickness. We report the validation of this model using analytical results and different computational methods like stochastic algorithms. Moreover, we check the model with experimental data from a specific scatterometer developed at the Onera. The advantages and disadvantages of a radiative approach are discussed. This paper represents a step toward the characterization of particles in dense media involving multiple scattering. -- Highlights: • A vectorial radiative transfer model to simulate the light scattered by stratified layers is developed. • The vectorial radiative transfer equation is solved using an adding–doubling technique. • The results are compared to analytical and stochastic data. • Validation with experimental data from a scatterometer developed at Onera is presented

  9. Polarimetric imaging of turbid inhomogeneous slab media based on backscattering using a pencil beam for illumination: Monte Carlo simulation

    Science.gov (United States)

    Otsuki, Soichi

    2018-04-01

    Polarimetric imaging of absorbing, strongly scattering, or birefringent inclusions is investigated in a negligibly absorbing, moderately scattering, and isotropic slab medium. It was proved that the reduced effective scattering Mueller matrix is exactly calculated from experimental or simulated raw matrices even if the medium is anisotropic and/or heterogeneous, or the outgoing light beam exits obliquely to the normal of the slab surface. The calculation also gives a reasonable approximation of the reduced matrix using a light beam with a finite diameter for illumination. The reduced matrix was calculated using a Monte Carlo simulation and was factorized in two dimensions by the Lu-Chipman polar decomposition. The intensity of backscattered light shows clear and modestly clear differences for absorbing and strongly scattering inclusions, respectively, whereas it shows no difference for birefringent inclusions. Conversely, some polarization parameters, for example, the selective depolarization coefficients exhibit only a slight difference for the absorbing inclusions, whereas they showed clear difference for the strongly scattering or birefringent inclusions. Moreover, these quantities become larger with increasing the difference in the optical properties of the inclusions relative to the surrounding medium. However, it is difficult to recognize inclusions that buried at the depth deeper than 3 mm under the surface. Thus, the present technique can detect the approximate shape and size of these inclusions, and considering the depth where inclusions lie, estimate their optical properties. This study reveals the possibility of the polarization-sensitive imaging of turbid inhomogeneous media using a pencil beam for illumination.

  10. Quantitatively characterizing the microstructural features of breast ductal carcinoma tissues in different progression stages by Mueller matrix microscope.

    Science.gov (United States)

    Dong, Yang; Qi, Ji; He, Honghui; He, Chao; Liu, Shaoxiong; Wu, Jian; Elson, Daniel S; Ma, Hui

    2017-08-01

    Polarization imaging has been recognized as a potentially powerful technique for probing the microstructural information and optical properties of complex biological specimens. Recently, we have reported a Mueller matrix microscope by adding the polarization state generator and analyzer (PSG and PSA) to a commercial transmission-light microscope, and applied it to differentiate human liver and cervical cancerous tissues with fibrosis. In this paper, we apply the Mueller matrix microscope for quantitative detection of human breast ductal carcinoma samples at different stages. The Mueller matrix polar decomposition and transformation parameters of the breast ductal tissues in different regions and at different stages are calculated and analyzed. For more quantitative comparisons, several widely-used image texture feature parameters are also calculated to characterize the difference in the polarimetric images. The experimental results indicate that the Mueller matrix microscope and the polarization parameters can facilitate the quantitative detection of breast ductal carcinoma tissues at different stages.

  11. MULTIFREQUENCY PHOTO-POLARIMETRIC WEBT OBSERVATION CAMPAIGN ON THE BLAZAR S5 0716+714: SOURCE MICROVARIABILITY AND SEARCH FOR CHARACTERISTIC TIMESCALES

    Energy Technology Data Exchange (ETDEWEB)

    Bhatta, G.; Stawarz, Ł.; Ostrowski, M. [Astronomical Observatory of Jagiellonian University, ul. Orla 171, 30-244 Krakow (Poland); Markowitz, A. [Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0424 (United States); Akitaya, H. [Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Arkharov, A. A. [Main (Pulkovo) Astronomical Observatory of RAS, Pulkovskoye shosse, 60, 196140 St. Petersburg (Russian Federation); Bachev, R. [Institute of Astronomy, Bulgarian Academy of Sciences, 72, Tsarigradsko Shosse Blvd., 1784 Sofia (Bulgaria); Benítez, E. [Instituto de Astronomía, Universidad Nacional Autónoma de México, Mexico DF (Mexico); Borman, G. A. [Crimean Astrophysical Observatory, P/O Nauchny, Crimea, 298409 (Russian Federation); Carosati, D. [EPT Observatories, Tijarafe, La Palma (Spain); Cason, A. D. [Private address, 105 Glen Pine Trail, Dawnsonville, GA 30534 (United States); Chanishvili, R. [Abastumani Observatory, Mt. Kanobili, 0301 Abastumani, Georgia (United States); Damljanovic, G. [Astronomical Observatory, Volgina 7, 11060 Belgrade (Serbia); Dhalla, S. [Florida International University, Miami, FL 33199 (United States); Frasca, A. [INAF—Osservatorio Astrofisico di Catania (Italy); Hiriart, D. [Instituto de Astronomía, Universidad Nacional Autónoma de México, Ensenada (Mexico); Hu, S-M., E-mail: gopalbhatta716@gmail.com [Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Sciences, Shandong University at Weihai, 264209 Weihai (China); and others

    2016-11-01

    Here we report on the results of the Whole Earth Blazar Telescope photo-polarimetric campaign targeting the blazar S5 0716+71, organized in 2014 March to monitor the source simultaneously in BVRI and near-IR filters. The campaign resulted in an unprecedented data set spanning ∼110 hr of nearly continuous, multiband observations, including two sets of densely sampled polarimetric data mainly in the R filter. During the campaign, the source displayed pronounced variability with peak-to-peak variations of about 30% and “bluer-when-brighter” spectral evolution, consisting of a day-timescale modulation with superimposed hour-long microflares characterized by ∼0.1 mag flux changes. We performed an in-depth search for quasi-periodicities in the source light curve; hints for the presence of oscillations on timescales of ∼3 and ∼5 hr do not represent highly significant departures from a pure red-noise power spectrum. We observed that, at a certain configuration of the optical polarization angle (PA) relative to the PA of the innermost radio jet in the source, changes in the polarization degree (PD) led the total flux variability by about 2 hr; meanwhile, when the relative configuration of the polarization and jet angles altered, no such lag could be noted. The microflaring events, when analyzed as separate pulse emission components, were found to be characterized by a very high PD (>30%) and PAs that differed substantially from the PA of the underlying background component, or from the radio jet positional angle. We discuss the results in the general context of blazar emission and energy dissipation models.

  12. MULTIFREQUENCY PHOTO-POLARIMETRIC WEBT OBSERVATION CAMPAIGN ON THE BLAZAR S5 0716+714: SOURCE MICROVARIABILITY AND SEARCH FOR CHARACTERISTIC TIMESCALES

    International Nuclear Information System (INIS)

    Bhatta, G.; Stawarz, Ł.; Ostrowski, M.; Markowitz, A.; Akitaya, H.; Arkharov, A. A.; Bachev, R.; Benítez, E.; Borman, G. A.; Carosati, D.; Cason, A. D.; Chanishvili, R.; Damljanovic, G.; Dhalla, S.; Frasca, A.; Hiriart, D.; Hu, S-M.

    2016-01-01

    Here we report on the results of the Whole Earth Blazar Telescope photo-polarimetric campaign targeting the blazar S5 0716+71, organized in 2014 March to monitor the source simultaneously in BVRI and near-IR filters. The campaign resulted in an unprecedented data set spanning ∼110 hr of nearly continuous, multiband observations, including two sets of densely sampled polarimetric data mainly in the R filter. During the campaign, the source displayed pronounced variability with peak-to-peak variations of about 30% and “bluer-when-brighter” spectral evolution, consisting of a day-timescale modulation with superimposed hour-long microflares characterized by ∼0.1 mag flux changes. We performed an in-depth search for quasi-periodicities in the source light curve; hints for the presence of oscillations on timescales of ∼3 and ∼5 hr do not represent highly significant departures from a pure red-noise power spectrum. We observed that, at a certain configuration of the optical polarization angle (PA) relative to the PA of the innermost radio jet in the source, changes in the polarization degree (PD) led the total flux variability by about 2 hr; meanwhile, when the relative configuration of the polarization and jet angles altered, no such lag could be noted. The microflaring events, when analyzed as separate pulse emission components, were found to be characterized by a very high PD (>30%) and PAs that differed substantially from the PA of the underlying background component, or from the radio jet positional angle. We discuss the results in the general context of blazar emission and energy dissipation models.

  13. Microarray-based mutation detection and phenotypic characterization in Korean patients with retinitis pigmentosa

    Science.gov (United States)

    Kim, Cinoo; Kim, Kwang Joong; Bok, Jeong; Lee, Eun-Ju; Kim, Dong-Joon; Oh, Ji Hee; Park, Sung Pyo; Shin, Joo Young; Lee, Jong-Young

    2012-01-01

    Purpose To evaluate microarray-based genotyping technology for the detection of mutations responsible for retinitis pigmentosa (RP) and to perform phenotypic characterization of patients with pathogenic mutations. Methods DNA from 336 patients with RP and 360 controls was analyzed using the GoldenGate assay with microbeads containing 95 previously reported disease-associated mutations from 28 RP genes. Mutations identified by microarray-based genotyping were confirmed by direct sequencing. Segregation analysis and phenotypic characterization were performed in patients with mutations. The disease severity was assessed by visual acuity, electroretinography, optical coherence tomography, and kinetic perimetry. Results Ten RP-related mutations of five RP genes (PRP3 pre-mRNA processing factor 3 homolog [PRPF3], rhodopsin [RHO], phosphodiesterase 6B [PDE6B], peripherin 2 [PRPH2], and retinitis pigmentosa 1 [RP1]) were identified in 26 of the 336 patients (7.7%) and in six of the 360 controls (1.7%). The p.H557Y mutation in PDE6B, which was homozygous in four patients and heterozygous in nine patients, was the most frequent mutation (2.5%). Mutation segregation was assessed in four families. Among the patients with missense mutations, the most severe phenotype occurred in patients with p.D984G in RP1; less severe phenotypes occurred in patients with p.R135W in RHO; a relatively moderate phenotype occurred in patients with p.T494M in PRPF3, p.H557Y in PDE6B, or p.W316G in PRPH2; and a mild phenotype was seen in a patient with p.D190N in RHO. Conclusions The results reveal that the GoldenGate assay may not be an efficient method for molecular diagnosis in RP patients with rare mutations, although it has proven to be reliable and efficient for high-throughput genotyping of single-nucleotide polymorphisms. The clinical features varied according to the mutations. Continuous effort to identify novel RP genes and mutations in a population is needed to improve the efficiency and

  14. Detection and characterization of zoonotic dermatophytes from dogs and cats in and around Kolkata

    Directory of Open Access Journals (Sweden)

    S. Murmu

    2015-09-01

    Full Text Available Aim: The ringworms of pet dogs, cats, and stray animals (dogs, cats, and other animals could be a potential source of zoonotic infections causing a serious public health problem in the busy city Kolkata. The pet owners are more susceptible to get this infection from their pets, because of the close contact with them as dermatophytosis is very much prevalent in those pets. So, this study was aimed to check the prevalence of dermatophytosis in dogs, cats, and in pet owners. Materials and Methods: A total of 362 clinically suspected cases of dermatophytosis from dogs (123 in number, cats (202 in number, and human beings (37 in number were collected and studied from in and around Kolkata to detect the presence of significant dermatophytes. Direct microscopy and cultural examination of the isolates were performed following standard methodology. Identification and characterization of the isolates were done by different biochemical tests. Results: Samples (n=285 having significant dermatophytic fungal infections were found to be of highest number in cats (158, 55.5% than in dogs (108, 37.8% and humans (19, 6.7%, respectively. The incidence of Microsporum canis (60.0% was the highest from affecting dogs, cats, and human beings in comparison to Microsporum gypseum (22.5%, Trichophyton mentagrophytes (15.8% and Trichophyton rubrum (1.7%. Detection of T. rubrum was only from human cases in this study, whereas the presence of rest three were slightly higher in cats than that of the dogs and humans in this present study. The incidences were higher in young animals and in humans of the age group of 21-30 years, during the rainy season (from April to August and also in in-contact human beings. Conclusion: M. canis was the most commonly pathogen among all causing dermatophytosis in animals and also in the pet owners. M. gypseum and T. mentagrophytes were other pathogens associated with these infections. These infections were more prevalent in the rainy seasons

  15. Computational modeling and experimental characterization of bacterial microcolonies for rapid detection using light scattering

    Science.gov (United States)

    Bai, Nan

    A label-free and nondestructive optical elastic forward light scattering method has been extended for the analysis of microcolonies for food-borne bacteria detection and identification. To understand the forward light scattering phenomenon, a model based on the scalar diffraction theory has been employed: a bacterial colony is considered as a biological spatial light modulator with amplitude and phase modulation to the incoming light, which continues to propagate to the far-field to form a distinct scattering 'fingerprint'. Numerical implementation via angular spectrum method (ASM) and Fresnel approximation have been carried out through Fast Fourier Transform (FFT) to simulate this optical model. Sampling criteria to achieve unbiased and un-aliased simulation results have been derived and the effects of violating these conditions have been studied. Diffraction patterns predicted by these two methods (ASM and Fresnel) have been compared to show their applicability to different simulation settings. Through the simulation work, the correlation between the colony morphology and its forward scattering pattern has been established to link the number of diffraction rings and the half cone angle with the diameter and the central height of the Gaussian-shaped colonies. In order to experimentally prove the correlation, a colony morphology analyzer has been built and used to characterize the morphology of different bacteria genera and investigate their growth dynamics. The experimental measurements have demonstrated the possibility of differentiating bacteria Salmonella, Listeria, Escherichia in their early growth stage (100˜500 µm) based on their phenotypic characteristics. This conclusion has important implications in microcolony detection, as most bacteria of our interest need much less incubation time (8˜12 hours) to grow into this size range. The original forward light scatterometer has been updated to capture scattering patterns from microcolonies. Experiments have

  16. Molecular detection and characterization of Anaplasma platys in dogs and ticks in Cuba.

    Science.gov (United States)

    Silva, Claudia Bezerra da; Santos, Huarrisson Azevedo; Navarrete, Maylín González; Ribeiro, Carla Carolina Dias Uzedo; Gonzalez, Belkis Corona; Zaldivar, Maykelin Fuentes; Pires, Marcus Sandes; Peckle, Maristela; Costa, Renata Lins da; Vitari, Gabriela Lopes Vivas; Massard, Carlos Luiz

    2016-07-01

    Canine cyclic thrombocytopenia, an infectious disease caused by Anaplasma platys is a worldwide dog health problem. This study aimed to detect and characterize A. platys deoxyribonucleic acid (DNA) in dogs and ticks from Cuba using molecular methods. The study was conducted in four cities of Cuba (Habana del Este, Boyeros, Cotorro and San José de las Lajas). Blood samples were collected from 100 dogs in these cities. The animals were inspected for the detection of tick infestation and specimens were collected. Genomic DNA was extracted from dog blood and ticks using a commercial kit. Genomic DNA samples from blood and ticks were tested by a nested polymerase chain reaction (nPCR) to amplify 678 base pairs (bp) from the 16S ribosomal DNA (rDNA) of A. platys. Positive samples in nPCR were also subjected to PCR to amplify a fragment of 580bp from the citrate synthase (gltA) gene and the products were sequenced. Only Rhipicephalus sanguineus sensu lato (s.l.) was found on dogs, and 10.20% (n=5/49) of these ticks plus sixteen percent (16.0%, n=16/100) of dogs were considered positive for A. platys by nPCR targeting the 16S rDNA gene. All analyzed gltA and 16S rDNA sequences showed a 99-100% identity with sequences of A. platys reported in around the world. Phylogenetic analysis showed two defined clusters for the 16S rDNA gene and three defined clusters for the gltA gene. Based on the gltA gene, the deduced amino acid sequence showed two mutations at positions 88 and 168 compared with the sequence DQ525687 (GenBank ID from Italian sample), used as a reference in the alignment. A preliminary study on the epidemiological aspects associated with infection by A. platys showed no statistical association with the variables studied (p>0.05). This is the first evidence of the presence of A. platys in dogs and ticks in Cuba. Further studies are needed to evaluate the epidemiological aspects of A. platys infection in Cuban dogs. Copyright © 2016 Elsevier GmbH. All rights

  17. Astrovirus-induced "white chicks" condition - field observation, virus detection and preliminary characterization.

    Science.gov (United States)

    Sajewicz-Krukowska, Joanna; Pać, Krzysztof; Lisowska, Anna; Pikuła, Anna; Minta, Zenon; Króliczewska, Bożena; Domańska-Blicharz, Katarzyna

    2016-01-01

    Chicken astrovirus (CAstV) was recently indicated as the factor of the "white chicks" condition associated not only with increased embryo/chick mortality but also with weakness and white plumage of hatched chicks. In February 2014, organ samples (livers and kidneys) from dead-in-shell embryos, as well as 1-day-old whitish and normal chicks, were delivered from one hatchery in Poland for disease diagnosis. The samples originated from the same 30-week-old breeder flock in which the only observed abnormal signs were 4-5% decrease in the number of hatched chickens and the presence (about 1%) of weaker chicks with characteristic whitish plumage among normal ones. CAstV was detected in submitted samples and was then isolated in 10-day-old embryonated specific pathogen free (SPF) chicken eggs. We also reproduced an infection model for the "white chicks" condition in SPF layer chickens using the isolated PL/G059/2014 strain as the infectious agent. Results of experimental reproduction of the "white chicks" condition were somewhat more serious than field observation. The administration of the CAstV material into the yolk sac of 8-day-old SPF chicken eggs caused delay and prolongation of hatching, as well as death of embryos/chicks, and also a change of plumage pigmentation. Only two chicks of a total of 10 inoculated SPF eggs survived and were observed for 2 months. A gradual elimination of the CAstV genome was noted in this period. Moreover, a few contact-naive SPF chicks, which had been placed in the same cage, were infected with CAstV. Molecular characterization of detected CAstV was performed by nucleotide sequencing of the full ORF2 region encoding the capsid precursor protein gene. Phylogenetic studies showed that the PL/G059/2014 isolate clustered in the subgroup Aiii of CAstV. In the light of the new classification rules, the Polish PL/G059/2014 CAstV isolate could be assigned to a new species of the Avastrovirus genus.

  18. Detection and characterization of diverse coccidian protozoa shed by California sea lions

    Science.gov (United States)

    Girard, Yvette A.; Johnson, Christine K.; Fritz, Heather M.; Shapiro, Karen; Packham, Andrea E.; Melli, Ann C.; Carlson-Bremer, Daphne; Gulland, Frances M.; Rejmanek, Daniel; Conrad, Patricia A.

    2015-01-01

    Tissue-cyst forming coccidia in the family Sarcocystidae are etiologic agents of protozoal encephalitis in marine mammals including the federally listed Southern sea otter (Enhydra lutris). California sea lions (Zalophus californianus), whose coastal habitat overlaps with sea otters, are definitive hosts for coccidian protozoa provisionally named Coccidia A, B and C. While Coccidia A and B have unknown clinical effects on aquatic wildlife hosts, Coccidia C is associated with severe protozoal disease in harbor seals (Phoca vitulina). In this study, we conducted surveillance for protozoal infection and fecal shedding in hospitalized and free-ranging California sea lions on the Pacific Coast and examined oocyst morphology and phenotypic characteristics of isolates via mouse bioassay and cell culture. Coccidia A and B were shed in similar frequency, particularly by yearlings. Oocysts shed by one free-ranging sea lion sampled at Año Nuevo State Park in California were previously unidentified in sea lions and were most similar to coccidia infecting Guadalupe fur seals (Arctocephalus townsendi) diagnosed with protozoal disease in Oregon (USA). Sporulated Coccidia A and B oocysts did not replicate in three strains of mice or in African green monkey kidney cells. However, cultivation experiments revealed that the inoculum of fecally-derived Coccidia A and B oocysts additionally contained organisms with genetic and antigenic similarity to Sarcocystis neurona; despite the absence of detectable free sporocysts in fecal samples by microscopic examination. In addition to the further characterization of Coccidia A and B in free-ranging and hospitalized sea lions, these results provide evidence of a new role for sea lions as putative mechanical vectors of S. neurona, or S. neurona-like species. Future work is needed to clarify the distribution, taxonomical status, and pathogenesis of these parasites in sea lions and other marine mammals that share their the near-shore marine

  19. Detection and characterization of diverse coccidian protozoa shed by California sea lions.

    Science.gov (United States)

    Girard, Yvette A; Johnson, Christine K; Fritz, Heather M; Shapiro, Karen; Packham, Andrea E; Melli, Ann C; Carlson-Bremer, Daphne; Gulland, Frances M; Rejmanek, Daniel; Conrad, Patricia A

    2016-04-01

    Tissue-cyst forming coccidia in the family Sarcocystidae are etiologic agents of protozoal encephalitis in marine mammals including the federally listed Southern sea otter (Enhydra lutris). California sea lions (Zalophus californianus), whose coastal habitat overlaps with sea otters, are definitive hosts for coccidian protozoa provisionally named Coccidia A, B and C. While Coccidia A and B have unknown clinical effects on aquatic wildlife hosts, Coccidia C is associated with severe protozoal disease in harbor seals (Phoca vitulina). In this study, we conducted surveillance for protozoal infection and fecal shedding in hospitalized and free-ranging California sea lions on the Pacific Coast and examined oocyst morphology and phenotypic characteristics of isolates via mouse bioassay and cell culture. Coccidia A and B were shed in similar frequency, particularly by yearlings. Oocysts shed by one free-ranging sea lion sampled at Año Nuevo State Park in California were previously unidentified in sea lions and were most similar to coccidia infecting Guadalupe fur seals (Arctocephalus townsendi) diagnosed with protozoal disease in Oregon (USA). Sporulated Coccidia A and B oocysts did not replicate in three strains of mice or in African green monkey kidney cells. However, cultivation experiments revealed that the inoculum of fecally-derived Coccidia A and B oocysts additionally contained organisms with genetic and antigenic similarity to Sarcocystis neurona; despite the absence of detectable free sporocysts in fecal samples by microscopic examination. In addition to the further characterization of Coccidia A and B in free-ranging and hospitalized sea lions, these results provide evidence of a new role for sea lions as putative mechanical vectors of S. neurona, or S. neurona-like species. Future work is needed to clarify the distribution, taxonomical status, and pathogenesis of these parasites in sea lions and other marine mammals that share their the near-shore marine

  20. Accurate means of detecting and characterizing abnormal patterns of ventricular activation by phase image analysis

    Energy Technology Data Exchange (ETDEWEB)

    Botvinick, E.H.; Frais, M.A.; Shosa, D.W.; O' Connell, J.W.; Pacheco-Alvarez, J.A.; Scheinman, M.; Hattner, R.S.; Morady, F.; Faulkner, D.B.

    1982-08-01

    The ability of scintigraphic phase image analysis to characterize patterns of abnormal ventricular activation was investigated. The pattern of phase distribution and sequential phase changes over both right and left ventricular regions of interest were evaluated in 16 patients with normal electrical activation and wall motion and compared with those in 8 patients with an artificial pacemaker and 4 patients with sinus rhythm with the Wolff-Parkinson-White syndrome and delta waves. Normally, the site of earliest phase angle was seen at the base of the interventricular septum, with sequential change affecting the body of the septum and the cardiac apex and then spreading laterally to involve the body of both ventricles. The site of earliest phase angle was located at the apex of the right ventricle in seven patients with a right ventricular endocardial pacemaker and on the lateral left ventricular wall in one patient with a left ventricular epicardial pacemaker. In each case the site corresponded exactly to the position of the pacing electrode as seen on posteroanterior and left lateral chest X-ray films, and sequential phase changes spread from the initial focus to affect both ventricles. In each of the patients with the Wolff-Parkinson-White syndrome, the site of earliest ventricular phase angle was located, and it corresponded exactly to the site of the bypass tract as determined by endocardial mapping. In this way, four bypass pathways, two posterior left paraseptal, one left lateral and one right lateral, were correctly localized scintigraphically. On the basis of the sequence of mechanical contraction, phase image analysis provides an accurate noninvasive method of detecting abnormal foci of ventricular activation.

  1. Accurate means of detecting and characterizing abnormal patterns of ventricular activation by phase image analysis

    International Nuclear Information System (INIS)

    Botvinick, E.H.; Frais, M.A.; Shosa, D.W.; O'Connell, J.W.; Pacheco-Alvarez, J.A.; Scheinman, M.; Hattner, R.S.; Morady, F.; Faulkner, D.B.

    1982-01-01

    The ability of scintigraphic phase image analysis to characterize patterns of abnormal ventricular activation was investigated. The pattern of phase distribution and sequential phase changes over both right and left ventricular regions of interest were evaluated in 16 patients with normal electrical activation and wall motion and compared with those in 8 patients with an artificial pacemaker and 4 patients with sinus rhythm with the Wolff-Parkinson-White syndrome and delta waves. Normally, the site of earliest phase angle was seen at the base of the interventricular septum, with sequential change affecting the body of the septum and the cardiac apex and then spreading laterally to involve the body of both ventricles. The site of earliest phase angle was located at the apex of the right ventricle in seven patients with a right ventricular endocardial pacemaker and on the lateral left ventricular wall in one patient with a left ventricular epicardial pacemaker. In each case the site corresponded exactly to the position of the pacing electrode as seen on posteroanterior and left lateral chest X-ray films, and sequential phase changes spread from the initial focus to affect both ventricles. In each of the patients with the Wolff-Parkinson-White syndrome, the site of earliest ventricular phase angle was located, and it corresponded exactly to the site of the bypass tract as determined by endocardial mapping. In this way, four bypass pathways, two posterior left paraseptal, one left lateral and one right lateral, were correctly localized scintigraphically. On the basis of the sequence of mechanical contraction, phase image analysis provides an accurate noninvasive method of detecting abnormal foci of ventricular activation

  2. Detection and characterization of diverse coccidian protozoa shed by California sea lions

    Directory of Open Access Journals (Sweden)

    Yvette A. Girard

    2016-04-01

    Full Text Available Tissue-cyst forming coccidia in the family Sarcocystidae are etiologic agents of protozoal encephalitis in marine mammals including the federally listed Southern sea otter (Enhydra lutris. California sea lions (Zalophus californianus, whose coastal habitat overlaps with sea otters, are definitive hosts for coccidian protozoa provisionally named Coccidia A, B and C. While Coccidia A and B have unknown clinical effects on aquatic wildlife hosts, Coccidia C is associated with severe protozoal disease in harbor seals (Phoca vitulina. In this study, we conducted surveillance for protozoal infection and fecal shedding in hospitalized and free-ranging California sea lions on the Pacific Coast and examined oocyst morphology and phenotypic characteristics of isolates via mouse bioassay and cell culture. Coccidia A and B were shed in similar frequency, particularly by yearlings. Oocysts shed by one free-ranging sea lion sampled at Año Nuevo State Park in California were previously unidentified in sea lions and were most similar to coccidia infecting Guadalupe fur seals (Arctocephalus townsendi diagnosed with protozoal disease in Oregon (USA. Sporulated Coccidia A and B oocysts did not replicate in three strains of mice or in African green monkey kidney cells. However, cultivation experiments revealed that the inoculum of fecally-derived Coccidia A and B oocysts additionally contained organisms with genetic and antigenic similarity to Sarcocystis neurona; despite the absence of detectable free sporocysts in fecal samples by microscopic examination. In addition to the further characterization of Coccidia A and B in free-ranging and hospitalized sea lions, these results provide evidence of a new role for sea lions as putative mechanical vectors of S. neurona, or S. neurona-like species. Future work is needed to clarify the distribution, taxonomical status, and pathogenesis of these parasites in sea lions and other marine mammals that share their the near

  3. The DLR project Wirbelschleppe. Detecting, characterizing, controlling, attenuating, understanding, and predicting aircraft wake vortices

    Energy Technology Data Exchange (ETDEWEB)

    Holzaepfel, F. (ed.)

    2008-07-01

    This collection of reports presents an excerpt of the investigations that were performed in the framework of the DLR Projekt Wirbelschleppe. A similar sample of reports was presented as part of three dedicated wake vortex sessions accomplished at the 1{sup st} European Air and Space Conference (CEAS 2007) and Deutscher Luft- und Raumfahrtkongress 2007 in Berlin. The Projekt Wirbelschleppe was conducted in two phases in the time frame from 1999 to 2007 with the five contributing DLR Institutes: Institute of Atmospheric Physics, Institute of Aerodynamics and Flow Technology, Institute of Flight Systems, Institute of Flight Guidance, Institute of Robotics and Mechatronics and the Institute of Aeronautics and Astronautics of the University of Technology Berlin. The project unified a multitude of different aspects and disciplines of wake vortex research which can be characterized by four main themes: - minimization of wake vortices by measures at the aircraft; - development and demonstration of a system for wake vortex prediction and observation; - airborne wake vortex detection and active control; - integration of systems into air traffic control. The Projekt Wirbelschleppe greatly benefited from the European projects AWIATOR, ATC-Wake, Credos, C-Wake, Eurowake, FAR-Wake, FLYSAFE, I-Wake, S-Wake, WakeNet, WakeNet2-Europe, WakeNet3-Europe, and Wavenc. DLR's wake vortex activities will be continued in the Projekt Wetter and Fliegen (2008-2011): Because the current compilation represents only a limited extract of the accomplished work, it is completed by a list of references emerging from the project. (orig.)

  4. SiPMs characterization and selection for the DUNE far detector photon detection system

    Science.gov (United States)

    Sun, Y.; Maricic, J.

    2016-01-01

    The Deep Underground Neutrino Experiment (DUNE) together with the Long Baseline Neutrino Facility (LBNF) hosted at the Fermilab will provide a unique, world-leading program for the exploration of key questions at the forefront of neutrino physics and astrophysics. CP violation in neutrino flavor mixing is one of its most important potential discoveries. Additionally, the experiment will determine the neutrino mass hierarchy and precisely measure the neutrino mixing parameters which may potentially reveal new fundamental symmetries of nature. Moreover, the DUNE is also designed for the observation of nucleon decay and supernova burst neutrinos. The photon detection (PD) system in the DUNE far detector provides trigger for cosmic backgrounds, enhances supernova burst trigger efficiency and improves the energy resolution of the detector. The DUNE adopts the technology of liquid argon time projection chamber (LArTPC) that requires the PD sensors, silicon photomultipliers (SiPM), to be carefully chosen to not only work properly in LAr temperature, but also meet certain specifications for the life of the experiment. A comprehensive testing of SiPMs in cryostat is necessary since the datasheet provided by the manufactures in the market does not cover this temperature regime. This paper gives the detailed characterization results of SenSL C-Series 60035 SiPMs, including gain, dark count rate (DCR), cross-talk and after-pulse rate. Characteristic studies on SiPMs from other vendors are also discussed in order to avoid any potential problems associated with using a single source. Moreover, the results of the ongoing mechanical durability tests are shown for the current candidate, SenSL B/C-Series 60035 SiPMs.

  5. Accuracy of the hypothetical sky-polarimetric Viking navigation versus sky conditions: revealing solar elevations and cloudinesses favourable for this navigation method

    Science.gov (United States)

    Száz, Dénes; Farkas, Alexandra; Barta, András; Kretzer, Balázs; Blahó, Miklós; Egri, Ádám; Szabó, Gyula; Horváth, Gábor

    2017-09-01

    According to Thorkild Ramskou's theory proposed in 1967, under overcast and foggy skies, Viking seafarers might have used skylight polarization analysed with special crystals called sunstones to determine the position of the invisible Sun. After finding the occluded Sun with sunstones, its elevation angle had to be measured and its shadow had to be projected onto the horizontal surface of a sun compass. According to Ramskou's theory, these sunstones might have been birefringent calcite or dichroic cordierite or tourmaline crystals working as polarizers. It has frequently been claimed that this method might have been suitable for navigation even in cloudy weather. This hypothesis has been accepted and frequently cited for decades without any experimental support. In this work, we determined the accuracy of this hypothetical sky-polarimetric Viking navigation for 1080 different sky situations characterized by solar elevation θ and cloudiness ρ, the sky polarization patterns of which were measured by full-sky imaging polarimetry. We used the earlier measured uncertainty functions of the navigation steps 1, 2 and 3 for calcite, cordierite and tourmaline sunstone crystals, respectively, and the newly measured uncertainty function of step 4 presented here. As a result, we revealed the meteorological conditions under which Vikings could have used this hypothetical navigation method. We determined the solar elevations at which the navigation uncertainties are minimal at summer solstice and spring equinox for all three sunstone types. On average, calcite sunstone ensures a more accurate sky-polarimetric navigation than tourmaline and cordierite. However, in some special cases (generally at 35° ≤ θ ≤ 40°, 1 okta ≤ ρ ≤ 6 oktas for summer solstice, and at 20° ≤ θ ≤ 25°, 0 okta ≤ ρ ≤ 4 oktas for spring equinox), the use of tourmaline and cordierite results in smaller navigation uncertainties than that of calcite. Generally, under clear or less cloudy

  6. Accuracy of the hypothetical sky-polarimetric Viking navigation versus sky conditions: revealing solar elevations and cloudinesses favourable for this navigation method.

    Science.gov (United States)

    Száz, Dénes; Farkas, Alexandra; Barta, András; Kretzer, Balázs; Blahó, Miklós; Egri, Ádám; Szabó, Gyula; Horváth, Gábor

    2017-09-01

    According to Thorkild Ramskou's theory proposed in 1967, under overcast and foggy skies, Viking seafarers might have used skylight polarization analysed with special crystals called sunstones to determine the position of the invisible Sun. After finding the occluded Sun with sunstones, its elevation angle had to be measured and its shadow had to be projected onto the horizontal surface of a sun compass. According to Ramskou's theory, these sunstones might have been birefringent calcite or dichroic cordierite or tourmaline crystals working as polarizers. It has frequently been claimed that this method might have been suitable for navigation even in cloudy weather. This hypothesis has been accepted and frequently cited for decades without any experimental support. In this work, we determined the accuracy of this hypothetical sky-polarimetric Viking navigation for 1080 different sky situations characterized by solar elevation θ and cloudiness ρ , the sky polarization patterns of which were measured by full-sky imaging polarimetry. We used the earlier measured uncertainty functions of the navigation steps 1, 2 and 3 for calcite, cordierite and tourmaline sunstone crystals, respectively, and the newly measured uncertainty function of step 4 presented here. As a result, we revealed the meteorological conditions under which Vikings could have used this hypothetical navigation method. We determined the solar elevations at which the navigation uncertainties are minimal at summer solstice and spring equinox for all three sunstone types. On average, calcite sunstone ensures a more accurate sky-polarimetric navigation than tourmaline and cordierite. However, in some special cases (generally at 35° ≤  θ  ≤ 40°, 1 okta ≤  ρ  ≤ 6 oktas for summer solstice, and at 20° ≤  θ  ≤ 25°, 0 okta ≤  ρ  ≤ 4 oktas for spring equinox), the use of tourmaline and cordierite results in smaller navigation uncertainties than that of calcite

  7. Development of a hard x-ray focal plane compton polarimeter: a compact polarimetric configuration with scintillators and Si photomultipliers

    Science.gov (United States)

    Chattopadhyay, T.; Vadawale, S. V.; Goyal, S. K.; Mithun, N. P. S.; Patel, A. R.; Shukla, R.; Ladiya, T.; Shanmugam, M.; Patel, V. R.; Ubale, G. P.

    2016-02-01

    X-ray polarization measurement of cosmic sources provides two unique parameters namely degree and angle of polarization which can probe the emission mechanism and geometry at close vicinity of the compact objects. Specifically, the hard X-ray polarimetry is more rewarding because the sources are expected to be intrinsically highly polarized at higher energies. With the successful implementation of Hard X-ray optics in NuSTAR, it is now feasible to conceive Compton polarimeters as focal plane detectors. Such a configuration is likely to provide sensitive polarization measurements in hard X-rays with a broad energy band. We are developing a focal plane hard X-ray Compton polarimeter consisting of a plastic scintillator as active scatterer surrounded by a cylindrical array of CsI(Tl) scintillators. The scatterer is 5 mm diameter and 100 mm long plastic scintillator (BC404) viewed by normal PMT. The photons scattered by the plastic scatterer are collected by a cylindrical array of 16 CsI(Tl) scintillators (5 mm × 5 mm × 150 mm) which are read by Si Photomultiplier (SiPM). Use of the new generation SiPMs ensures the compactness of the instrument which is essential for the design of focal plane detectors. The expected sensitivity of such polarimetric configuration and complete characterization of the plastic scatterer, specially at lower energies have been discussed in [11, 13]. In this paper, we characterize the CsI(Tl) absorbers coupled to SiPM. We also present the experimental results from the fully assembled configuration of the Compton polarimeter.

  8. Fabrication and characterization of a solid-state nanopore with self-aligned carbon nanoelectrodes for molecular detection

    International Nuclear Information System (INIS)

    Spinney, Patrick S; Collins, Scott D; Smith, Rosemary L; Howitt, David G

    2012-01-01

    Stochastic molecular sensors based on resistive pulse nanopore modalities are envisioned as facile DNA sequencers. However, recent advances in nanotechnology fabrication have highlighted promising alternative detection mechanisms with higher sensitivity and potential single-base resolution. In this paper we present the novel self-aligned fabrication of a solid-state nanopore device with integrated transverse graphene-like carbon nanoelectrodes for polyelectrolyte molecular detection. The electrochemical transduction mechanism is characterized and found to result primarily from thermionic emission between the two transverse electrodes. Response of the nanopore to Lambda dsDNA and short (16-mer) ssDNA is demonstrated and distinguished. (paper)

  9. Development and validation of P-MODTRAN7 and P-MCScene, 1D and 3D polarimetric radiative transfer models

    Science.gov (United States)

    Hawes, Frederick T.; Berk, Alexander; Richtsmeier, Steven C.

    2016-05-01

    A validated, polarimetric 3-dimensional simulation capability, P-MCScene, is being developed by generalizing Spectral Sciences' Monte Carlo-based synthetic scene simulation model, MCScene, to include calculation of all 4 Stokes components. P-MCScene polarimetric optical databases will be generated by a new version (MODTRAN7) of the government-standard MODTRAN radiative transfer algorithm. The conversion of MODTRAN6 to a polarimetric model is being accomplished by (1) introducing polarimetric data, by (2) vectorizing the MODTRAN radiation calculations and by (3) integrating the newly revised and validated vector discrete ordinate model VDISORT3. Early results, presented here, demonstrate a clear pathway to the long-term goal of fully validated polarimetric models.

  10. Detection, Characterization, and Biological Effect of Quorum-Sensing Signaling Molecules in Peanut-Nodulating Bradyrhizobia

    Directory of Open Access Journals (Sweden)

    Walter Giordano

    2012-03-01

    Full Text Available Bacteria of the genus Bradyrhizobium are able to establish a symbiotic relationship with peanut (Arachis hypogaea root cells and to fix atmospheric nitrogen by converting it to nitrogenous compounds. Quorum sensing (QS is a cell-cell communication mechanism employed by a variety of bacterial species to coordinate behavior at a community level through regulation of gene expression. The QS process depends on bacterial production of various signaling molecules, among which the N-acylhomoserine lactones (AHLs are most commonly used by Gram-negative bacteria. Some previous reports have shown the production of QS signaling molecules by various rhizobia, but little is known regarding mechanisms of communication among peanut-nodulating strains. The aims of this study were to identify and characterize QS signals produced by peanut-nodulating bradyrhizobial strains and to evaluate their effects on processes related to cell interaction. Detection of AHLs in 53 rhizobial strains was performed using the biosensor strains Agrobacterium tumefaciens NTL4 (pZLR4 and Chromobacterium violaceum CV026 for AHLs with long and short acyl chains, respectively. None of the strains screened were found to produce AHLs with short acyl chains, but 14 strains produced AHLs with long acyl chains. These 14 AHL-producing strains were further studied by quantification of β-galactosidase activity levels (AHL-like inducer activity in NTL4 (pZLR4. Strains displaying moderate to high levels of AHL-like inducer activity were subjected to chemical identification of signaling molecules by high-performance liquid chromatography coupled to mass spectrometry (LC-MS/MS. For each AHL-producing strain, we found at least four different AHLs, corresponding to N-hexanoyl-DL-homoserine lactone (C6, N-(3-oxodecanoyl-L-homoserine lactone (3OC10, N-(3-oxododecanoyl-L-homoserine lactone (3OC12, and N-(3-oxotetradecanoyl-L-homoserine lactone (3OC14. Biological roles of 3OC10, 3OC12, and 3OC14 AHLs

  11. Nanostructure Embedded Microchips for Detection, Isolation, and Characterization of Circulating Tumor Cells

    Science.gov (United States)

    2015-01-01

    Conspectus Circulating tumor cells (CTCs) are cancer cells that break away from either a primary tumor or a metastatic site and circulate in the peripheral blood as the cellular origin of metastasis. With their role as a “tumor liquid biopsy”, CTCs provide convenient access to all disease sites, including that of the primary tumor and the site of fatal metastases. It is conceivable that detecting and analyzing CTCs will provide insightful information in assessing the disease status without the flaws and limitations encountered in performing conventional tumor biopsies. However, identifying CTCs in patient blood samples is technically challenging due to the extremely low abundance of CTCs among a large number of hematologic cells. To address this unmet need, there have been significant research endeavors, especially in the fields of chemistry, materials science, and bioengineering, devoted to developing CTC detection, isolation, and characterization technologies. Inspired by the nanoscale interactions observed in the tissue microenvironment, our research team at UCLA pioneered a unique concept of “NanoVelcro” cell-affinity substrates, in which CTC capture agent-coated nanostructured substrates were utilized to immobilize CTCs with high efficiency. The working mechanism of NanoVelcro cell-affinity substrates mimics that of Velcro: when the two fabric strips of a Velcro fastener are pressed together, tangling between the hairy surfaces on two strips leads to strong binding. Through continuous evolution, three generations (gens) of NanoVelcro CTC chips have been established to achieve different clinical utilities. The first-gen NanoVelcro chip, composed of a silicon nanowire substrate (SiNS) and an overlaid microfluidic chaotic mixer, was created for CTC enumeration. Side-by-side analytical validation studies using clinical blood samples suggested that the sensitivity of first-gen NanoVelcro chip outperforms that of FDA-approved CellSearch. In conjunction with

  12. Generation, Detection and characterization of Gas-Phase Transition Metal containing Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Steimle, Timothy [Arizona State Univ., Tempe, AZ (United States)

    2015-12-15

    The objective of this project was to generate, detect, and characterize small, gas-phase, metal containing molecules. In addition to being relevant to high temperature chemical environments (e.g. plasmas and combustion), gas-phase experiments on metal containing molecules serve as the most direct link to a molecular-level theoretical model for catalysis. Catalysis (i.e. the addition of a small about of recoverable material to control the rate and direction of a chemical reaction) is critical to the petroleum and pharmaceutical industries as well as environmental remediation. Currently, the majority of catalytic materials are based on very expensive metals such as platinum (Pt), palladium (Pd), iridium (Ir,) rhenium (Re), and rhodium (Rh). For example, the catalyst used for converting linear hydrocarbon molecules (e.g. hexane) to cyclic molecules (e.g. cyclohexane) is a mixture of Pt and Re suspended on alumina. It enables straight chain alkanes to be converted into branched-chain alkanes, cyclohexanes and aromatic hydrocarbons which are used, amongst other things, to enhance the octane number of petrol. A second example is the heterogeneous catalysis used in automobile exhaust systems to: a) decrease nitrogen oxide; b) reduce carbon monoxide; and c) oxidize unburned hydrocarbons. The exhaust is vented through a high-surface area chamber lined with Pt, Pd, and Rh. For example, the carbon monoxide is catalytically converted to carbon dioxide by reaction with oxygen. The research results from this work have been published in readily accessible journals1-28. The ground and excited electronic state properties of small metal containing molecules that we determine were: a) electronic state distributions and lifetimes, b) vibrational frequencies, c) bond lengths and angles, d) hyperfine interactions, e) permanent electric dipole moments, mel, and f) magnetic dipoles, μm. In general terms, μel, gives insight into the charge distribution and mm into

  13. Study and characterization of the III-V semiconductor materials for applications in the detection of ionizing radiation

    International Nuclear Information System (INIS)

    Moulin, H.

    1989-11-01

    The photoconduction in the bulk of the gallium arsenide (GaAs) and of the indium phosphide doped with iron (InP:Fe) is investigated. These compounds are to be applied in devices for X-ray detection. In such semiconductor materials the detection of X-rays occurs in the bulk. The photoconduction theory and the characteristics of the materials are reviewed. Two computerized simulation models for studying the response of the photoconductors to the radiation pulses are described. The results concerning the following measurements are presented: the characterization of GaAs and InP:Fe photoconductors, in obscurity, as a function of the electric field of polarization and of the neutrons dose; and their characterization under X-ray radiation [fr

  14. Application of whole genome shotgun sequencing for detection and characterization of genetically modified organisms and derived products.

    Science.gov (United States)

    Holst-Jensen, Arne; Spilsberg, Bjørn; Arulandhu, Alfred J; Kok, Esther; Shi, Jianxin; Zel, Jana

    2016-07-01

    The emergence of high-throughput, massive or next-generation sequencing technologies has created a completely new foundation for molecular analyses. Various selective enrichment processes are commonly applied to facilitate detection of predefined (known) targets. Such approaches, however, inevitably introduce a bias and are prone to miss unknown targets. Here we review the application of high-throughput sequencing technologies and the preparation of fit-for-purpose whole genome shotgun sequencing libraries for the detection and characterization of genetically modified and derived products. The potential impact of these new sequencing technologies for the characterization, breeding selection, risk assessment, and traceability of genetically modified organisms and genetically modified products is yet to be fully acknowledged. The published literature is reviewed, and the prospects for future developments and use of the new sequencing technologies for these purposes are discussed.

  15. Evaluation of the efficiency of FDG PET/CT in detection and characterization of skeletal metastases

    Directory of Open Access Journals (Sweden)

    Ahmed Wafaie

    2014-03-01

    Conclusion: Fused PET/CT was highly efficient in evaluation of skeletal metastases with superior performance in: detection of early bone marrow infiltration not apparent on CT, resolution of metabolic activity before definite signs of complete healing on CT, detection of missed sclerotic metastases on PET due to their relatively low metabolic activity, detection of intra and extra osseous recurrence and differentiation of benign from malignant bone lesions.

  16. First Polarimetric GNSS-R Measurements from a Stratospheric Flight over Boreal Forests

    Directory of Open Access Journals (Sweden)

    Hugo Carreno-Luengo

    2015-10-01

    Full Text Available The first-ever dual-frequency multi-constellation Global Navigation Satellite Systems Reflectometry (GNSS-R polarimetric measurements over boreal forests and lakes from the stratosphere are presented. Data were collected during the European Space Agency (ESA sponsored Balloon Experiments for University Students (BEXUS 19 stratospheric balloon experiment using the P(Y and C/A Reflect Ometer (PYCARO instrument operated in closed-loop mode. Maps of the polarimetric ratio for L1 and L2 Global Positioning System (GPS and GLObal Navigation Satellite System (GLONASS, and for E1 Galileo signals are derived from the float phase at 27,000 m height, and the specular points are geolocalized on the Earth’s surface. Polarimetric ratio ( maps over boreal forests are shown to be in the range 2–16 dB for the different GNSS codes. This result suggests that the scattering is taking place not only over the soil, but over the different forests elements as well. Additionally to the interpretation of the experimental results a theoretical investigation of the different contributions to the total reflectivity over boreal forests is performed using a bistatic scattering model. The simulated cross- (reflected Left Hand Circular Polarization LHCP and co-polar (reflected Right Hand Circular Polarization RHCP reflectivities are evaluated for the soil, the canopy, and the canopy–soil interactions for three different biomass densities: 725 trees/ha, 150 trees/ha and 72 trees/ha. For elevation angles larger than the Brewster angle, it is found that the cross-polar signal is dominant when just single reflections over the forests are evaluated, while in the case of multiple reflections the co-polar signal becomes the largest one. The first-ever dual-frequency multi-constellation Global Navigation Satellite Systems Reflectometry (GNSS-R polarimetric measurements over boreal forests and lakes from the stratosphere are presented. Data were collected during the European Space

  17. Characterization of plastic scintillators for detection of radioactivity: Light yield, Time decay measurements and Neutron/γ Pulse Shape Discrimination

    International Nuclear Information System (INIS)

    Montbarbon, E.; Pansu, R.B.; Hamel, M.; Coulon, R.

    2015-07-01

    Since Helium-3 shortage, organic scintillators play a major role in neutron detection. CEA LIST decided to focus on plastic scintillators. By definition, a plastic scintillator is a radio-luminescent polymer; this means that it emits light after interaction with an ionizing radiation. A platform was developed to characterize lab-made prepared scintillators and to compare them with commercial scintillators. Three physicochemical criteria are determined with this unique platform. (authors)

  18. Restoration of polarimetric SAR images using simulated annealing

    DEFF Research Database (Denmark)

    Schou, Jesper; Skriver, Henning

    2001-01-01

    approach favoring one of the objectives. An algorithm for estimating the radar cross-section (RCS) for intensity SAR images has previously been proposed in the literature based on Markov random fields and the stochastic optimization method simulated annealing. A new version of the algorithm is presented......Filtering synthetic aperture radar (SAR) images ideally results in better estimates of the parameters characterizing the distributed targets in the images while preserving the structures of the nondistributed targets. However, these objectives are normally conflicting, often leading to a filtering...

  19. Study and characterization of semi-conductor materials III-V for their applications to the ionizing radiation detection

    International Nuclear Information System (INIS)

    Moulin, H.

    1989-01-01

    This work is the study of photoconduction in volume of gallium arsenide and of indium phosphide doped with iron for their applications to X-ray detection which is carried out directly in the material. After having recalled the physical characterization of materials and the principle of photoconduction, we describe two informatic simulations. The first supposes the spatial uniformity of the electric field on the semiconductor, the second takes the spatial and temporal variations of the field into consideration. Then we show the advantage of a first irradiation to neutrons of the photoconductors. With the gallium arsenide there is swiftness improvement of the detectors to the detriment of the sensitivity. The second part studies first the characterizations in the obscurity of the photoconductors according to the electric polarization field and to the neutron dose they received before and then their characterizations under X radiation. 77 refs., 221 figs., 33 tabs., 6 photos., 3 annexes

  20. Detection and Characterization of Reactive Oxygen and Nitrogen Species in Biological Systems by Monitoring Species-Specific Products.

    Science.gov (United States)

    Hardy, Micael; Zielonka, Jacek; Karoui, Hakim; Sikora, Adam; Michalski, Radosław; Podsiadły, Radosław; Lopez, Marcos; Vasquez-Vivar, Jeannette; Kalyanaraman, Balaraman; Ouari, Olivier

    2018-05-20

    Since the discovery of the superoxide dismutase enzyme, the generation and fate of short-lived oxidizing, nitrosating, nitrating, and halogenating species in biological systems has been of great interest. Despite the significance of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in numerous diseases and intracellular signaling, the rigorous detection of ROS and RNS has remained a challenge. Recent Advances: Chemical characterization of the reactions of selected ROS and RNS with electron paramagnetic resonance (EPR) spin traps and fluorescent probes led to the establishment of species-specific products, which can be used for specific detection of several forms of ROS and RNS in cell-free systems and in cultured cells in vitro and in animals in vivo. Profiling oxidation products from the ROS and RNS probes provides a rigorous method for detection of those species in biological systems. Formation and detection of species-specific products from the probes enables accurate characterization of the oxidative environment in cells. Measurement of the total signal (fluorescence, chemiluminescence, etc.) intensity does not allow for identification of the ROS/RNS formed. It is critical to identify the products formed by using chromatographic or other rigorous techniques. Product analyses should be accompanied by monitoring of the intracellular probe level, another factor controlling the yield of the product(s) formed. More work is required to characterize the chemical reactivity of the ROS/RNS probes, and to develop new probes/detection approaches enabling real-time, selective monitoring of the specific products formed from the probes. Antioxid. Redox Signal. 28, 1416-1432.

  1. A multiplex ligation detection assay for the characterization of Salmonella enterica strains

    DEFF Research Database (Denmark)

    Aarts, Henk J.M.; Vos, Pieter; Larsson, Jonas T.

    2011-01-01

    A proof of principle of a multi-target assay for genotyping Salmonella has been developed targeting 62 genomic marker sequences of Salmonella related to pathogenicity. The assay is based on multiplex ligation detection reaction (LDR) followed by customized ArrayTube® microarray detection. The fea...... assessors that support bio-traceability models....

  2. Characterization of the detectability of an intraoperative minigammacamera; Caracterizacion de la detectabilidad de una minigammacamara intraoperatoria

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Jimenez, J.; Nunez Martinez, L. M. R.; Morillas Ruiz, J.; Pizarro Trigo, F.; Crespo Mesa, S.; Ros Lorda, M.A.

    2011-07-01

    Screening of the sentinel node is a technique which is widely used in Nuclear Medicine Services for its ability to reduce the morbidity associated lymphadenectomy. This intervention is particularly important that accurate detection of the probe uptake, The aim of this study is to evaluate all the factors that influence the detection image by introducing the contributions of intraoperative minigammacamera systems. (Author)

  3. A multiplex ligation detection assay for the characterization of Salmonella enterica strains

    NARCIS (Netherlands)

    Aarts, H.J.M.; Vos, P.; Larsson, J.T.; Hoek, van A.H.A.M.; Huehn, S.; Weijers, T.; Gronlund, H.A.; Malorny, B.

    2011-01-01

    A proof of principle of a multi-target assay for genotyping Salmonella has been developed targeting 62 genomic marker sequences of Salmonella related to pathogenicity. The assay is based on multiplex ligation detection reaction (LDR) followed by customized ArrayTube (R) microarray detection. The

  4. Land-cover mapping using multitemporal, dual-frequency polarimetric SAR data

    DEFF Research Database (Denmark)

    Skriver, Henning; Schou, Jesper; Dierking, Wolfgang

    2000-01-01

    during the growing season acquired a lot of data over a Danish agricultural site. The data acquisitions were co-ordinated with ground surveys to obtain a detailed land cover map. The test area contains a large number of different land cover classes, such as more than 10 different crop types, deciduous......The Danish Center for Remote Sensing (DCRS) is, in collaboration with the Danish mapping agency, conducting a study on topographic mapping using SAR data, and land cover mapping results are presented. The Danish EMISAR system (an L- and C-band, fully polarimetric, airborne SAR) have in 1994 to 1999...

  5. A high resolution polarimetric L-band SAR-design and first results

    DEFF Research Database (Denmark)

    Skou, Niels; Granholm, Johan; Woelders, Kim

    1995-01-01

    the range of the radar is 64 km with a noise equivalent sigma naught of -20 dB. The antenna is a stacked microstrip patch array with the feed structure on the back side of the antenna panel to reduce unwanted radiation. The cross polar level is below -35 dB. The polarization switch is a relatively...... over the EMISAR calibration scene: An agricultural site in Denmark featuring a range of different fields and forested areas as well as several trihedrals and dihedrals. Based on the imagery data, sensor performance is assessed. The L- & C-band polarimetric EMISAR instrument is one of the key sensors...

  6. Microphysical Properties of Frozen Particles Inferred from Global Precipitation Measurement (GPM) Microwave Imager (GMI) Polarimetric Measurements

    Science.gov (United States)

    Gong, Jie; Wu, Dongliang

    2017-01-01

    Scattering differences induced by frozen particle microphysical properties are investigated, using the vertically (V) and horizontally (H) polarized radiances from the Global Precipitation Measurement (GPM) Microwave Imager (GMI) 89 and 166GHz channels. It is the first study on global frozen particle microphysical properties that uses the dual-frequency microwave polarimetric signals. From the ice cloud scenes identified by the 183.3 3GHz channel brightness temperature (TB), we find that the scatterings of frozen particles are highly polarized with V-H polarimetric differences (PD) being positive throughout the tropics and the winter hemisphere mid-latitude jet regions, including PDs from the GMI 89 and 166GHz TBs, as well as the PD at 640GHz from the ER-2 Compact Scanning Submillimeter-wave Imaging Radiometer (CoSSIR) during the TC4 campaign. Large polarization dominantly occurs mostly near convective outflow region (i.e., anvils or stratiform precipitation), while the polarization signal is small inside deep convective cores as well as at the remote cirrus region. Neglecting the polarimetric signal would result in as large as 30 error in ice water path retrievals. There is a universal bell-curve in the PD TB relationship, where the PD amplitude peaks at 10K for all three channels in the tropics and increases slightly with latitude. Moreover, the 166GHz PD tends to increase in the case where a melting layer is beneath the frozen particles aloft in the atmosphere, while 89GHz PD is less sensitive than 166GHz to the melting layer. This property creates a unique PD feature for the identification of the melting layer and stratiform rain with passive sensors. Horizontally oriented non-spherical frozen particles are thought to produce the observed PD because of different ice scattering properties in the V and H polarizations. On the other hand, changes in the ice microphysical habitats or orientation due to turbulence mixing can also lead to a reduced PD in the deep

  7. Effect of Medium Symmetries in Limiting the Number of Parameters Estimated with Polarimetric Interferometry

    Science.gov (United States)

    Moghaddam, Mahta

    2000-01-01

    The addition of interferometric backscattering pairs to the conventional polarimetric SAR data over forests and other vegetated areas increases the dimensionality of the data space, in principle enabling the estimation of a larger number of vegetation parameters. Without regard to the sensitivity of these data to vegetation scattering parameters, this paper poses the question: Will increasing the data channels as such result in a one-to-one increase in the number of parameters that can be estimated, or do vegetation and data properties inherently limit that number otherwise? In this paper, the complete polarimetric interferometric covariance matrix is considered and various symmetry properties of the scattering medium are used to study whether any of the correlation pairs can be eliminated. The number of independent pairs has direct consequences in their utility in parameter estimation schemes, since the maximum number of parameters that can be estimated cannot exceed the number of unique measurements. The independent components of the polarimetric interferometric SAR (POL/INSAR) data are derived for media with reflection, rotation, and azimuth symmetries, which are often encountered in vegetated surfaces. Similar derivations have been carried out before for simple polarimetry, i.e., zero baseline. This paper extends those to the interferometric case of general nonzero baselines. It is shown that depending on the type of symmetries present, the number of independent available measurements that can be used to estimate medium parameters will vary. In particular, whereas in the general case there are 27 mathematically independent measurements possible from a polarimetric interferometer, this number can be reduced to 15, 9, and 6 if the medium has reflection, rotation, or azimuthal symmetries, respectively. The results can be used in several ways in the interpretation of SAR data and the development of parameter estimation schemes, which will be discussed at the

  8. A New Ka-Band Scanning Radar Facility: Polarimetric and Doppler Spectra Measurements of Snow Events

    Science.gov (United States)

    Oue, M.; Kollias, P.; Luke, E. P.; Mead, J.

    2017-12-01

    Polarimetric radar analyses offer the capability of identification of ice hydrometeor species as well as their spatial distributions. In addition to polarimetric parameter observations, Doppler spectra measurements offer unique insights into ice particle properties according to particle fall velocities. In particular, millimeter-wavelength radar Doppler spectra can reveal supercooled liquid cloud droplets embedded in ice precipitation clouds. A Ka-band scanning polarimetric radar, named KASPR, was installed in an observation facility at Stony Brook University, located 22 km west of the KOKX NEXRAD radar at Upton, NY. The KASPR can measure Doppler spectra and full polarimetric variables, including radar reflectivity, differential reflectivity (ZDR), differential phase (φDP), specific differential phase (KDP), correlation coefficient (ρhv), and linear depolarization ratio (LDR). The facility also includes a micro-rain radar and a microwave radiometer capable of measuring reflectivity profiles and integrated liquid water path, respectively. The instruments collected initial datasets during two snowstorm events and two snow shower events in March 2017. The radar scan strategy was a combination of PPI scans at 4 elevation angles (10, 20, 45, and 60°) and RHI scans in polarimetry mode, and zenith pointing with Doppler spectra collection. During the snowstorm events the radar observed relatively larger ZDR (1-1.5 dB) and enhanced KDP (1-2 ° km-1) at heights corresponding to a plate/dendrite crystal growth regime. The Doppler spectra showed that slower-falling particles ( 1 m s-1). The weakly increased ZDR could be produced by large, faster falling particles such as quasi-spherical aggregates, while the enhanced KDP could be produced by highly-oriented oblate, slowly-falling particles. Below 2 km altitude, measurements of dual wavelength ratio (DWR) based on Ka and S-band reflectivities from the KASPR and NEXRAD radars were available. Larger DWR (>10 dB) suggested

  9. Split bundle detection in polarimetric images of the human retinal nerve fiber layer

    NARCIS (Netherlands)

    Vermeer, K. A.; Reus, N. J.; Vos, F. M.; Lemij, H. G.; Vossepoel, A. M.

    2007-01-01

    One method for assessing pathological retinal nerve fiber layer (NFL) appearance is by comparing the NFL to normative values, derived from healthy subjects. These normative values will be more specific when normal physiological differences are taken into account. One common variation is a split

  10. Disturbance Detection in Snow Using Polarimetric Imagery of the Visible Spectrum

    Science.gov (United States)

    2010-12-01

    Perpendicular to Equipotential Surfaces . (From Georgia State University, http://hyperphysics.phy- astr.gsu.edu/hbase/electric/equipot.html#c3, 2010...order to maintain field lines that are perpendicular to the equipotential 13 surfaces (Serway, 1998). The dipoles equipotential surfaces are...compressed due to the proximity of unlike charges and can be seen in Figure 9. Figure 9. Electric Field Lines Perpendicular to Equipotential Surfaces

  11. Molecular characterization of norovirus GII.17 detected in healthy adult, intussusception patient, and acute gastroenteritis children in Thailand.

    Science.gov (United States)

    Khamrin, Pattara; Kumthip, Kattareeya; Yodmeeklin, Arpaporn; Supadej, Kanittapon; Ukarapol, Nuthapong; Thongprachum, Aksara; Okitsu, Shoko; Hayakawa, Satoshi; Ushijima, Hiroshi; Maneekarn, Niwat

    2016-10-01

    Noroviruses (NoVs) have been recognized as a leading cause of sporadic cases and outbreaks of acute gastroenteritis in all age groups. During the surveillance of NoVs in Chiang Mai, Thailand, four cases of the novel GII.17 NoVs were sporadically detected by RT-PCR in 2014-2015. The first case of GII.17 was detected in a healthy adult who worked for a restaurant. The second case was found in a pediatric patient who admitted to the hospital with intussusception. The third and fourth cases were found in acute gastroenteritis children. Phylogenetic analysis clearly demonstrated that GII.17 NoVs detected in this study were genetically closely related with the novel GII.17 Kawasaki reference strains. These four GII.17 NoV positive specimens were also tested by two immunochromatographic test kits in order to evaluate the sensitivity for GII.17 NoV detection. The viral loads in those specimens were determined by real-time RT-PCR. The sensitivity of GII.17 NoV detection varies by individual test kits and also depending on the amount of the viruses contained in the fecal specimens. In summary, our study reported the detection of novel GII.17 NoVs in a wide range of subjects with and without diarrhea. Therefore, continued comprehensive screening and genetic molecular characterization of NoV strains circulating in this area need to be further investigated. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. The GNSS polarimetric radio-occultation technique to sense precipitation events: a new concept to be tested aboard PAZ Low Earth Satellite

    Science.gov (United States)

    Tomás, Sergio; Oliveras, Santi; Cardellach, Estel; Rius, Antonio

    2013-04-01

    based on the asymmetry between the vertical and horizontal axis of the rain droplets, especially when intense rates of precipitation occur. As a first approximation, the RO signals propagate across the precipitation-volume tangentially, that is, along the local horizontal axis of the droplets. Forward scattering models have been implemented to quantify the sensitivity of L-band signals to different rain rates and precipitation extension being crossed by the signals. The observable considered so far is the polarimetric phase shift: difference between the phase delay suffered by the H- and V-polarizations. Real RO events have been collocated with TRMM precipitation data. The path traveled by the RO signal under a given altitude has been projected on the TRMM grid of observations, to obtain a profile of the precipitation being crossed by the RO link at a given moment of the occultation event. This mechanism has been used to feed the propagation models and thus estimate the polarimetric phase shift that each precipitation event would have induced into the occultation observation. This simulation exercise permits to determine the detectability thresholds and the expected statistics of such collocated events. Methodology and results will be presented.

  13. Fractal mechanism for characterizing singularity of mode shape for damage detection

    Energy Technology Data Exchange (ETDEWEB)

    Cao, M. S. [Department of Engineering Mechanics, Hohai University, Nanjing 210098 (China); Ostachowicz, W. [Institute of Fluid-Flow Machinery, Polish Academy of Sciences, ul. Fiszera 14, 80-952 Gdansk (Poland); Faculty of Automotive and Construction Machinery, Warsaw University of Technology, Narbutta 84, 02-524 Warsaw (Poland); Bai, R. B., E-mail: bairunbo@gmail.com [Department of Engineering Mechanics, Shandong Agricultural University, Taian 271000 (China); Radzieński, M. [Institute of Fluid-Flow Machinery, Polish Academy of Sciences, ul. Fiszera 14, 80-952 Gdansk (Poland)

    2013-11-25

    Damage is an ordinary physical phenomenon jeopardizing structural safety; damage detection is an ongoing interdisciplinary issue. Waveform fractal theory has provided a promising resource for detecting damage in plates while presenting a concomitant problem: susceptibility to false features of damage. This study proposes a fractal dimension method based on affine transformation to address this problem. Physical experiments using laser measurement demonstrate that this method can substantially eliminate false features of damage and accurately identify complex cracks in plates, providing a fundamental mechanism that brings the merits of waveform fractal theory into full play in structural damage detection applications.

  14. Detection and characterization of corrosion of bridge cables by time domain reflectometry

    Science.gov (United States)

    Liu, Wei; Hunsperger, Robert G.; Folliard, Kevin; Chajes, Michael J.; Barot, Jignesh; Jhaveri, Darshan; Kunz, Eric

    1999-02-01

    In this paper, we develop and demonstrate a nondestructive evaluation technique for corrosion detection of embedded or encased steel cables. This technique utilizes time domain reflectometry (TDR), which has been traditionally used to detect electrical discontinuities in transmission lines. By applying a sensor wire along with the bridge cable, we can model the cable as an asymmetric, twin-conductor transmission line. Physical defects of the bridge cable will change the electromagnetic properties of the line and can be detected by TDR. Furthermore, different types of defects can be modeled analytically, and identified using TDR. TDR measurement results from several fabricated bridge cable sections with built-in defects are reported.

  15. Consistent Practices for Characterizing the Detection Limits of Fracture Critical Metallic Component Inspection Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA-STD-5009 requires that successful flaw detection by NDE methods be statistically qualified for use on fracture critical metallic components using Probability of...

  16. Detection and characterization of foodborne pathogenic bacteria with hyperspectral microscope imaging

    Science.gov (United States)

    Rapid detection and identification of pathogenic microorganisms naturally occurring during food processing are important in developing intervention and verification strategies. In the poultry industry, contamination of poultry meat with foodborne pathogens (especially, Salmonella and Campylobacter) ...

  17. Development of Rapid Detection and Genetic Characterization of Salmonella in Poultry Breeder Feeds

    Science.gov (United States)

    Jarquin, Robin; Hanning, Irene; Ahn, Soohyoun; Ricke, Steven C.

    2009-01-01

    Salmonella is a leading cause of foodborne illness in the United States, with poultry and poultry products being a primary source of infection to humans. Poultry may carry some Salmonella serovars without any signs or symptoms of disease and without causing any adverse effects to the health of the bird. Salmonella may be introduced to a flock by multiple environmental sources, but poultry feed is suspected to be a leading source. Detecting Salmonella in feed can be challenging because low levels of the bacteria may not be recovered using traditional culturing techniques. Numerous detection methodologies have been examined over the years for quantifying Salmonella in feeds and many have proven to be effective for Salmonella isolation and detection in a variety of feeds. However, given the potential need for increased detection sensitivity, molecular detection technologies may the best candidate for developing rapid sensitive methods for identifying small numbers of Salmonella in the background of large volumes of feed. Several studies have been done using polymerase chain reaction (PCR) assays and commercial kits to detect Salmonella spp. in a wide variety of feed sources. In addition, DNA array technology has recently been utilized to track the dissemination of a specific Salmonella serotype in feed mills. This review will discuss the processing of feeds and potential points in the process that may introduce Salmonella contamination to the feed. Detection methods currently used and the need for advances in these methods also will be discussed. Finally, implementation of rapid detection for optimizing control methods to prevent and remove any Salmonella contamination of feeds will be considered. PMID:22346699

  18. Development of Rapid Detection and Genetic Characterization of Salmonella in Poultry Breeder Feeds

    Directory of Open Access Journals (Sweden)

    Steven C. Ricke

    2009-07-01

    Full Text Available Salmonella is a leading cause of foodborne illness in the United States, with poultry and poultry products being a primary source of infection to humans. Poultry may carry some Salmonella serovars without any signs or symptoms of disease and without causing any adverse effects to the health of the bird. Salmonella may be introduced to a flock by multiple environmental sources, but poultry feed is suspected to be a leading source. Detecting Salmonella in feed can be challenging because low levels of the bacteria may not be recovered using traditional culturing techniques. Numerous detection methodologies have been examined over the years for quantifying Salmonella in feeds and many have proven to be effective for Salmonella isolation and detection in a variety of feeds. However, given the potential need for increased detection sensitivity, molecular detection technologies may the best candidate for developing rapid sensitive methods for identifying small numbers of Salmonella in the background of large volumes of feed. Several studies have been done using polymerase chain reaction (PCR assays and commercial kits to detect Salmonella spp. in a wide variety of feed sources. In addition, DNA array technology has recently been utilized to track the dissemination of a specific Salmonella serotype in feed mills. This review will discuss the processing of feeds and potential points in the process that may introduce Salmonella contamination to the feed. Detection methods currently used and the need for advances in these methods also will be discussed. Finally, implementation of rapid detection for optimizing control methods to prevent and remove any Salmonella contamination of feeds will be considered.

  19. Optimization and characterization of condensation nucleation light scattering detection coupled with supercritical fluid chromatography

    Science.gov (United States)

    Yang, Shaoping

    This dissertation is an investigation of two aspects of coupling condensation nucleation light scattering detection (CNLSD) with supercritical fluid chromatography (SFC). In the first part, it was demonstrated that CNLSD was compatible with packed column SFC using either pure CO2 or organic solvent modified CO2 as mobile phases. Factors which were expected to affect the interface between SFC and CNLSD were optimized for the detector to reach low detection limits. With SFC using pure CO2 as mobile phase, the detection limit of CNLSD with SFC was observed to be at low nanogram levels, which was at the same level of flame ionization detection (FID) coupled with SFC. For SFC using modified CO2 as mobile phase, detection limits at the picogram level were observed for CNLSD at optimal conditions, which were at least ten times lower than those reached by evaporative light scattering detection. In the second part, particle size distributions of aerosols produced from rapid expansion of supercritical solutions were measured with a scanning mobility particle sizer. The effect of the factors, which were investigated in the first part for their effects on signal intensities and signal to noise ratios (S/N), on particle size distributions (PSDs) of both analyte and background were investigated. Whenever possible, both particle sizes and particle number obtained from PSDs were used to explain the optimization results. In general, PSD data support the observations made in the first part. The detection limits of CNLSD obtained were much higher than predicted. PSDs did not provide direct explanation of this problem. The amount of analyte deposited in the transport tubing, evaporated to gas phase, and condensed to form particles was determined experimentally. Almost no analyte was found in the gas phase. Less than 3% was found in the particle forms. The vast majority of analyte was lost in the transport tubing, especially in the short distance after supercritical fluid expansion. A

  20. PEPSI: the Potsdam Echelle Polarimetric and Spectroscopic Instrument for the LBT

    Science.gov (United States)

    Strassmeier, K. G.; Woche, M.; Ilyin, I.; Popow, E.; Bauer, S.-M.; Dionies, F.; Fechner, T.; Weber, M.; Hofmann, A.; Storm, J.; Materne, R.; Bittner, W.; Bartus, J.; Granzer, T.; Denker, C.; Carroll, T.; Kopf, M.; DiVarano, I.; Beckert, E.; Lesser, M.

    2008-07-01

    We present the status of PEPSI, the bench-mounted fibre-fed and stabilized "Potsdam Echelle Polarimetric and Spectroscopic Instrument" for the 2×8.4m Large Binocular Telescope in southern Arizona. PEPSI is under construction at AIP and is scheduled for first light in 2009/10. Its ultra-high-resolution mode will deliver an unprecedented spectral resolution of approximately R=310,000 at high efficiency throughout the entire optical/red wavelength range 390-1050nm without the need for adaptive optics. Besides its polarimetric Stokes IQUV mode, the capability to cover the entire optical range in three exposures at resolutions of 40,000, 130,000 and 310,000 will surpass all existing facilities in terms of light-gathering-power times spectral-coverage product. A solar feed will make use of the spectrograph also during day time. As such, we hope that PEPSI will be the most powerful spectrometer of its kind for the years to come.

  1. Polarimetric rainfall retrieval from a C-Band weather radar in a tropical environment (The Philippines)

    Science.gov (United States)

    Crisologo, I.; Vulpiani, G.; Abon, C. C.; David, C. P. C.; Bronstert, A.; Heistermann, Maik

    2014-11-01

    We evaluated the potential of polarimetric rainfall retrieval methods for the Tagaytay C-Band weather radar in the Philippines. For this purpose, we combined a method for fuzzy echo classification, an approach to extract and reconstruct the differential propagation phase, Φ DP , and a polarimetric self-consistency approach to calibrate horizontal and differential reflectivity. The reconstructed Φ DP was used to estimate path-integrated attenuation and to retrieve the specific differential phase, K DP . All related algorithms were transparently implemented in the Open Source radar processing software wradlib. Rainfall was then estimated from different variables: from re-calibrated reflectivity, from re-calibrated reflectivity that has been corrected for path-integrated attenuation, from the specific differential phase, and from a combination of reflectivity and specific differential phase. As an additional benchmark, rainfall was estimated by interpolating the rainfall observed by rain gauges. We evaluated the rainfall products for daily and hourly accumulations. For this purpose, we used observations of 16 rain gauges from a five-month period in the 2012 wet season. It turned out that the retrieval of rainfall from K DP substantially improved the rainfall estimation at both daily and hourly time scales. The measurement of reflectivity apparently was impaired by severe miscalibration while K DP was immune to such effects. Daily accumulations of rainfall retrieved from K DP showed a very low estimation bias and small random errors. Random scatter was, though, strongly present in hourly accumulations.

  2. Rainfall Estimation Using Specific Differential Phase for the First Operational Polarimetric Radar in Korea

    Directory of Open Access Journals (Sweden)

    Cheol-Hwan You

    2014-01-01

    Full Text Available To assess the performance of rainfall estimation using specific differential phase observed by Bislsan radar, the first polarimetric radar in Korea, three rainfall cases occurring in 2011 were selected, each caused by different conditions: the first is the Changma front and typhoon, the second is only the Changma front, and the third is only a typhoon. For quantitative use of specific differential phase (KDP, a data quality algorithm was developed for differential phase shift (ΦDP, composed of two steps; the first involves removal of scattered noise and the second is unfolding of ΦDP. This order of the algorithm is necessary so as not to remove unfolded areas, which are the real meteorological target. All noise was removed and the folded ΦDP were unfolded successfully for this study. RKDP relations for S-band radar were calculated for 84,754 samples of observed drop size distribution (DSD using different drop shape assumptions. The relation for the Bringi drop shape showed the best statistics: 0.28 for normalized error, and 6.7 mm for root mean square error for rainfall heavier than 10 mm h-1. Because the drop shape assumption affects the accuracy of rainfall estimation differently for different rainfall types, such characteristics should be taken into account to estimate rainfall more accurately using polarimetric variables.

  3. Direct {sup 13}C-detected NMR experiments for mapping and characterization of hydrogen bonds in RNA

    Energy Technology Data Exchange (ETDEWEB)

    Fürtig, Boris, E-mail: fuertig@nmr.uni-frankfurt.de; Schnieders, Robbin; Richter, Christian; Zetzsche, Heidi; Keyhani, Sara; Helmling, Christina [Johann Wolfgang Goethe Universität Frankfurt, Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Organic Chemistry and Chemical Biology (Germany); Kovacs, Helena [Bruker BioSpin (Switzerland); Schwalbe, Harald, E-mail: schwalbe@nmr.uni-frankfurt.de [Johann Wolfgang Goethe Universität Frankfurt, Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Organic Chemistry and Chemical Biology (Germany)

    2016-03-15

    In RNA secondary structure determination, it is essential to determine whether a nucleotide is base-paired and not. Base-pairing of nucleotides is mediated by hydrogen bonds. The NMR characterization of hydrogen bonds relies on experiments correlating the NMR resonances of exchangeable protons and can be best performed for structured parts of the RNA, where labile hydrogen atoms are protected from solvent exchange. Functionally important regions in RNA, however, frequently reveal increased dynamic disorder which often leads to NMR signals of exchangeable protons that are broadened beyond {sup 1}H detection. Here, we develop {sup 13}C direct detected experiments to observe all nucleotides in RNA irrespective of whether they are involved in hydrogen bonds or not. Exploiting the self-decoupling of scalar couplings due to the exchange process, the hydrogen bonding behavior of the hydrogen bond donor of each individual nucleotide can be determined. Furthermore, the adaption of HNN-COSY experiments for {sup 13}C direct detection allows correlations of donor–acceptor pairs and the localization of hydrogen-bond acceptor nucleotides. The proposed {sup 13}C direct detected experiments therefore provide information about molecular sites not amenable by conventional proton-detected methods. Such information makes the RNA secondary structure determination by NMR more accurate and helps to validate secondary structure predictions based on bioinformatics.

  4. Spatial-Temporal Synchrophasor Data Characterization and Analytics in Smart Grid Fault Detection, Identification, and Impact Causal Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Huaiguang; Dai, Xiaoxiao; Gao, David Wenzhong; Zhang, Jun Jason; Zhang, Yingchen; Muljadi, Eduard

    2016-09-01

    An approach of big data characterization for smart grids (SGs) and its applications in fault detection, identification, and causal impact analysis is proposed in this paper, which aims to provide substantial data volume reduction while keeping comprehensive information from synchrophasor measurements in spatial and temporal domains. Especially, based on secondary voltage control (SVC) and local SG observation algorithm, a two-layer dynamic optimal synchrophasor measurement devices selection algorithm (OSMDSA) is proposed to determine SVC zones, their corresponding pilot buses, and the optimal synchrophasor measurement devices. Combining the two-layer dynamic OSMDSA and matching pursuit decomposition, the synchrophasor data is completely characterized in the spatial-temporal domain. To demonstrate the effectiveness of the proposed characterization approach, SG situational awareness is investigated based on hidden Markov model based fault detection and identification using the spatial-temporal characteristics generated from the reduced data. To identify the major impact buses, the weighted Granger causality for SGs is proposed to investigate the causal relationship of buses during system disturbance. The IEEE 39-bus system and IEEE 118-bus system are employed to validate and evaluate the proposed approach.

  5. Standard Format for Chromatographic-polarimetric System small samples assessment

    International Nuclear Information System (INIS)

    Naranjo, S.; Fajer, V.; Fonfria, C.; Patinno, R.

    2012-01-01

    The treatment of samples containing optically active substances to be evaluated as part of quality control of raw material entering industrial process, and also during the modifications exerted on it to obtain the desired final composition is still and unsolved problem for many industries. That is the case of sugarcane industry. Sometimes the troubles implied are enlarged because samples to be evaluated are not bigger than one milliliter. Reduction of gel beds in G-10 and G-50 chromatographic columns having an inner diameter of 16 mm, instead of 25, and bed heights adjustable to requirements by means of sliding stoppers to increase analytical power were evaluated with glucose and sucrose standards in concentrations from 1 to 10 g/dL, using aliquots of 1 ml without undesirable dilutions that could affect either detection or chromatographic profile. Assays with seaweed extracts gave good results that are shown. It is established the advantage to know concentration of a separated substance by the height of its peak and the savings in time and reagents resulting . Sample expanded uncertainty in both systems is compared. It is also presented several programs for data acquisition, storing and processing. (Author)

  6. Impact of seeing and host galaxy into the analysis of photo-polarimetric microvariability in blazars. Case study of the nearby blazars 1ES 1959+650 and HB89 2201+044

    Science.gov (United States)

    Sosa, M. S.; von Essen, C.; Andruchow, I.; Cellone, S. A.

    2017-11-01

    Blazars, a type of Active Galactic Nuclei, present a particular orientation of their jets close to the line of sight. Their radiation is thus relativistically beamed, giving rise to extreme behaviors, specially strong variability on very short timescales (I.e., microvariability). Here we present simultaneous photometric and polarimetric observations of two relatively nearby blazars, 1ES 1959+650 and HB89 2201+044, that were obtained using the Calar Alto Faint Object Spectrograph mounted at the 2.2 m telescope in Calar Alto, Spain. An outstanding characteristic of these two blazars is the presence of well resolved host galaxies. This particular feature allows us to produce a study of their intrinsic polarization, a measurement of the polarization state of the galactic nucleus unaffected by the host galaxy. To carry out this work, we computed photometric fluxes from which we calculated the degree and orientation of the blazars polarization. Then, we analyzed the depolarizing effect introduced by the host galaxy with the main goal to recover the intrinsic polarization of the galactic nucleus, carefully taking into consideration the spurious polarimetric variability introduced by changes in seeing along the observing nights. We find that the two blazars do not present intra-night photo-polarimetric variability, although we do detect a significant inter-night variability. Comparing polarimetric values before and after accounting for the host galaxies, we observe a significant difference in the polarization degree of about 1% in the case of 1ES 1959+650, and 0.3% in the case of HB89 2201+044, thus evidencing the non-negligible impact introduced by the host galaxies. We note that this host galaxy effect depends on the waveband, and varies with changing seeing conditions, so it should be particularly considered when studying frequency-dependent polarization in blazars. Based on observations collected at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto, operated

  7. Design and characterization of a magnetoelastic sensor for the detection of biological agents

    International Nuclear Information System (INIS)

    Shen Wen; Mathison, Leslie C; Chin, Bryan A; Petrenko, Valery A

    2010-01-01

    This paper presents the design and development of a free-standing, magnetoelastic biosensor. The detection principle is presented and various resonance characteristics of the sensor are discussed. Experimental measurements of the sensor resonance frequencies agree with theoretical predictions. The influence of the external magnetic field on the resonance behaviour of the sensor was studied and the optimum dc magnetic fields for best sensitivity in air and in water solutions for 2000 x 400 x 15 μm (2 mm) sensors and 1000 x 200 x 15 μm (1 mm) size sensors were determined to be 75 Oe and 38 Oe, respectively. Both theoretical prediction and experimental results show that smaller sensors have greater mass sensitivity and can theoretically detect mass as small as one biological spore. The sensor platform was immobilized with JRB7 phages for specific, in vitro detection of B. anthracis spores. Real-time detection of spores suspended in water was demonstrated using a flowing system. The 1 mm and 2 mm sensors were found to have a detection limit of 10 4 spores ml -1 and 10 5 spores ml -1 , respectively.

  8. Characterization of rotavirus strains detected among children and adults with acute gastroenteritis in Ganozan, Saudi Arabia

    International Nuclear Information System (INIS)

    Kheyami, Ali M.; Dove, W.; Cunliffe, Nigel A.; Hart, C.A.; Areeshi, Mohammed Y.; Nakagomi, O.

    2008-01-01

    Objective was to assess the circulating rotavirus strains among hospitalized children and adults in Gizan City. This cross-sectional study was based in 5 hospitals in the Gizan area. Stool samples were collected between November 2004 and March 2005 from sequential patients with acute dehydrating diarrhea. Rotavirus antigen was detected in stool by enzyme-linked immunosorbent assay. The diversity of rotavirus strains was investigated using electropherotyping and reverse transcription-polymerase chain reaction amplification of the VP7 and VP4 genes (G and P genotyping). Rotavirus was detected in 54 of 454 (12%) subjects. The ages of those infected with rotavirus ranged from 15 days to 20 years, with a median age of 36 months. The highest rotavirus detection rate (24%) occurred in children in aged 48-59 months. Overall, 50 (93%) of strains could be assigned both a G- and P- type; G1P (8) was the most frequently detected strain type (n=48, 89%) with one rotavirus each of G2P (4) and G9P (8). Rotavirus strains circulating in Gizan would be well covered by current rotavirus vaccines. Rotavirus serotype G9 has been detected in Saudi Arabia for the first time. Continued surveillance of rotavirus strains is required. (author)

  9. Decomposition of Polarimetric SAR Images Based on Second- and Third-order Statics Analysis

    Science.gov (United States)

    Kojima, S.; Hensley, S.

    2012-12-01

    There are many papers concerning the research of the decomposition of polerimetric SAR imagery. Most of them are based on second-order statics analysis that Freeman and Durden [1] suggested for the reflection symmetry condition that implies that the co-polarization and cross-polarization correlations are close to zero. Since then a number of improvements and enhancements have been proposed to better understand the underlying backscattering mechanisms present in polarimetric SAR images. For example, Yamaguchi et al. [2] added the helix component into Freeman's model and developed a 4 component scattering model for the non-reflection symmetry condition. In addition, Arii et al. [3] developed an adaptive model-based decomposition method that could estimate both the mean orientation angle and a degree of randomness for the canopy scattering for each pixel in a SAR image without the reflection symmetry condition. This purpose of this research is to develop a new decomposition method based on second- and third-order statics analysis to estimate the surface, dihedral, volume and helix scattering components from polarimetric SAR images without the specific assumptions concerning the model for the volume scattering. In addition, we evaluate this method by using both simulation and real UAVSAR data and compare this method with other methods. We express the volume scattering component using the wire formula and formulate the relationship equation between backscattering echo and each component such as the surface, dihedral, volume and helix via linearization based on second- and third-order statics. In third-order statics, we calculate the correlation of the correlation coefficients for each polerimetric data and get one new relationship equation to estimate each polarization component such as HH, VV and VH for the volume. As a result, the equation for the helix component in this method is the same formula as one in Yamaguchi's method. However, the equation for the volume

  10. Prevalence and methodologies for detection, characterization and subtyping of Listeria monocytogenes and L. ivanovii in foods and environmental sources

    Directory of Open Access Journals (Sweden)

    Jin-Qiang Chen

    2017-09-01

    Full Text Available Listeria monocytogenes, one of the most important foodborne pathogens, can cause listeriosis, a lethal disease for humans. L. ivanovii, which is closely related to L. monocytogenes, is also widely distributed in nature and infects mainly warm-blooded ruminants, causing economic loss. Thus, there are high priority needs for methodologies for rapid, specific, cost-effective and accurate detection, characterization and subtyping of L. monocytogenes and L. ivanovii in foods and environmental sources. In this review, we (A described L. monocytogenes and L. ivanovii, world-wide