WorldWideScience

Sample records for hybrid focal plane

  1. Enabling Large Focal Plane Arrays Through Mosaic Hybridization

    Science.gov (United States)

    Miller, Timothy M.; Jhabvala, Christine A.; Leong, Edward; Costen, Nicholas P.; Sharp, Elmer; Adachi, Tomoko; Benford, Dominic J.

    2012-01-01

    We have demonstrated advances in mosaic hybridization that will enable very large format far-infrared detectors. Specifically we have produced electrical detector models via mosaic hybridization yielding superconducting circuit paths by hybridizing separately fabricated sub-units onto a single detector unit. The detector model was made on a 100mm diameter wafer while four model readout quadrant chips were made from a separate 100mm wafer. The individually fabricated parts were hybridized using a flip-chip bonder to assemble the detector-readout stack. Once all of the hybridized readouts were in place, a single, large and thick silicon substrate was placed on the stack and attached with permanent epoxy to provide strength and a Coefficient of Thermal Expansion match to the silicon components underneath. Wirebond pads on the readout chips connect circuits to warm readout electronics; and were used to validate the successful superconducting electrical interconnection of the model mosaic-hybrid detector. This demonstration is directly scalable to 150 mm diameter wafers, enabling pixel areas over ten times the area currently available.

  2. Testing of focal plane arrays

    International Nuclear Information System (INIS)

    Merriam, J.D.

    1988-01-01

    Problems associated with the testing of focal plane arrays are briefly examined with reference to the instrumentation and measurement procedures. In particular, the approach and instrumentation used as the Naval Ocean Systems Center is presented. Most of the measurements are made with flooded illumination on the focal plane array. The array is treated as an ensemble of individual pixels, data being taken on each pixel and array averages and standard deviations computed for the entire array. Data maps are generated, showing the pixel data in the proper spatial position on the array and the array statistics

  3. SNAP Satellite Focal Plane Development

    International Nuclear Information System (INIS)

    Bebek, C.; Akerlof, C.; Aldering, G.; Amanullah, R.; Astier, P.; Baltay, C.; Barrelet, E.; Basa, S.; Bercovitz, J.; Bergstrom, L.; Berstein, G.P.; Bester, M.; Bohlin, R.; Bonissent, A.; Bower, C.; Campbell, M.; Carithers, W.; Commins, E.; Day, C.; Deustua, S.; DiGennaro, R.; Ealet, A.; Ellis, R.; Emmett, W.; Eriksson, M.; Fouchez, D.; Fruchter, A.; Genat, J-F.; Goldhaber, G.; Goobar, A.; Groom, D.; Heetderks, H.; Holland, S.; Huterer, D.; Johnson, W.; Kadel, R.; Karcher, A.; Kim, A.; Kolbe, W.; Lafever, R.; Lamoureaux, J.; Lampton, M.; Lefevre, O.; Levi, M.; Levin, D.; Linder, E.; Loken, S.; Malina, R.; Mazure, A.; McKay, T.; McKee, S.; Miquel, R.; Morgan, N.; Mortsell, E.; Mostek, N.; Mufson, S.; Musser, J.; Roe, N.; Nugent, P.; Oluseyi, H.; Pain, R.; Palaio, N.; Pankow, D.; Perlmutter, S.; Prieto, E.; Rabinowitz, D.; Refregier, A.; Rhodes, J.; Schubnell, M.; Sholl, M.; Smadja, G.; Smith, R.; Smoot, G.; Snyder, J.; Spadafora, A.; Szymkowiak, A.; Tarle, G.; Taylor, K.; Tilquin, A.; Tomasch, A.; Vincent, D.; von der Lippe, H.; Walder, J-P.; Wang, G.

    2003-01-01

    The proposed SuperNova/Acceleration Probe (SNAP) mission will have a two-meter class telescope delivering diffraction-limited images to an instrumented 0.7 square degree field in the visible and near-infrared wavelength regime. The requirements for the instrument suite and the present configuration of the focal plane concept are presented. A two year R and D phase, largely supported by the Department of Energy, is just beginning. We describe the development activities that are taking place to advance our preparedness for mission proposal in the areas of detectors and electronics

  4. Systems considerations in mosaic focal planes

    Science.gov (United States)

    White, K. P., III

    1983-08-01

    Two key reasons for pursuing the development of mosaic focal planes are reviewed and it is shown that rapid frame repetition rate is the only requirement that can be solved no other way than through mosaic focal planes. With the view that spaceborne mosaic focal plane sensors are necessarily 'smart sensors' requiring a lot of onboard processing just to function, it is pointed out that various artificial intelligence techniques may be the most appropriate to incorporate in the data processing. Finally, a novel mosaic focal plane design is proposed, termed a virtual mosaic focal plane, in response to other system constraints.

  5. Flux dynamics in ultrasensitive superconducting focal planes

    Data.gov (United States)

    National Aeronautics and Space Administration — The performance of superconducting focal planes will drive the achievable specifications of ultrasensitive instruments for NASA astrophysics missions, yet they have...

  6. Infrared MUSIC from Z technology focal planes

    International Nuclear Information System (INIS)

    Waters, C.R.; Sommese, A.; Johnston, D.; Landau, H.

    1989-01-01

    Presented is the Multiple Signal Classification (MUSIC) algorithm which uses the high frequency differences in sensed time signals to discriminate, count, and accurately locate closely spaced targets. Z technology focal planes allow the implementation of this algorithm and the trade-off between finer spatial resolution systems and systems with coarser resolution but higher sampling rates

  7. Focal plane scanner with reciprocating spatial window

    Science.gov (United States)

    Mao, Chengye (Inventor)

    2000-01-01

    A focal plane scanner having a front objective lens, a spatial window for selectively passing a portion of the image therethrough, and a CCD array for receiving the passed portion of the image. All embodiments have a common feature whereby the spatial window and CCD array are mounted for simultaneous relative reciprocating movement with respect to the front objective lens, and the spatial window is mounted within the focal plane of the front objective. In a first embodiment, the spatial window is a slit and the CCD array is one-dimensional, and successive rows of the image in the focal plane of the front objective lens are passed to the CCD array by an image relay lens interposed between the slit and the CCD array. In a second embodiment, the spatial window is a slit, the CCD array is two-dimensional, and a prism-grating-prism optical spectrometer is interposed between the slit and the CCD array so as to cause the scanned row to be split into a plurality of spectral separations onto the CCD array. In a third embodiment, the CCD array is two-dimensional and the spatial window is a rectangular linear variable filter (LVF) window, so as to cause the scanned rows impinging on the LVF to be bandpass filtered into spectral components onto the CCD array through an image relay lens interposed between the LVF and the CCD array.

  8. Multispectral linear array (MLA) focal plane mechanical and thermal design

    Science.gov (United States)

    Mitchell, A. S.; Kaminski, E. F.

    1982-01-01

    The mechanical and thermal design of an integrated focal plane subsystem of a Multispectral Linear Array (MLA) instrument is discussed in terms of focal-plane alignment, thermoelastic performance, and thermal requirements. The modular construction and thermal control of the focal plane array are discussed.

  9. The Simbol-X Focal Plane

    Science.gov (United States)

    Laurent, P.

    2009-05-01

    The Simbol-X focal plane is designed to detect photons focused by the mirror in the 0.5 to 100 keV energy band. Composed of two detectors, it will measure the position, energy, and arrival time of each incoming X-ray. On top of it will be a collimator to shield all photons not coming from the mirror field of view. The whole system is surrounded by an active and passive shielding in order to ensure the required very low background.

  10. Characterization of DECam focal plane detectors

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, H.Thomas; Angstadt, Robert; Campa, Julia; Cease, Herman; Derylo, Greg; Emes, John H.; Estrada, Juan; Kibik, Donna; Flaugher, Brenna L.; Holland, Steve E.; Jonas, Michelle; /Fermilab /Madrid, CIEMAT /LBL, Berkeley /Argonne /Pennsylvania U.

    2008-06-01

    DECam is a 520 Mpix, 3 square-deg FOV imager being built for the Blanco 4m Telescope at CTIO. This facility instrument will be used for the 'Dark Energy Survey' of the southern galactic cap. DECam has chosen 250 ?m thick CCDs, developed at LBNL, with good QE in the near IR for the focal plane. In this work we present the characterization of these detectors done by the DES team, and compare it to the DECam technical requirements. The results demonstrate that the detectors satisfy the needs for instrument.

  11. The Sentinel-4 UVN focal plane assemblies

    Science.gov (United States)

    Hinger, Jürgen; Hohn, Rüdiger; Gebhardt, Eyk; Reichardt, Jörg

    2017-09-01

    The Sentinel-4 UVN Instrument is a dispersive imaging spectrometer covering the UV-VIS and the NIR wavelength. It is developed and built under an ESA contract by an industrial consortium led by Airbus Defence and Space. It will be accommodated on board of the MTG-S (Meteosat Third Generation - Sounder) satellite that will be placed in a geostationary orbit over Europe sampling data for generating two-dimensional maps of a number of atmospheric trace gases. The incoming light is dispersed by reflective gratings and detected by the two (UVVIS and NIR) CCDs mounted inside the focal plane assemblies. Both CCD detectors acquire spectral channels and spatial sampling in two orthogonal directions and will be operated at about 215 K mainly to minimize random telegraph signal effects and to reduce dark current. Stringent detector temperature as well as alignment stability requirements of less than +/-0.1 K per day respectively of less than 2 micrometers/2 arcseconds from ground to orbit are driving the FPA thermo-mechanical design. A specific FPA design feature is the redundant LED-calibration system for bad pixel detection as well as pixel gain and linearity monitoring. This paper reports on the design and qualification of the Focal Plane Assemblies with emphasis on thermo-mechanical as well as alignment stability verification.

  12. The Sentinel 4 focal plane subsystem

    Science.gov (United States)

    Hohn, Rüdiger; Skegg, Michael P.; Hermsen, Markus; Hinger, Jürgen; Williges, Christian; Reulke, Ralf

    2017-09-01

    The Sentinel 4 instrument is an imaging spectrometer, developed by Airbus under ESA contract in the frame of the joint European Union (EU)/ESA COPERNICUS program with the objective of monitoring trace gas concentrations. Sentinel 4 will provide accurate measurements of key atmospheric constituents such as ozone, nitrogen dioxide, sulfur dioxide, formaldehyde, as well as aerosol and cloud properties. Sentinel 4 is unique in being the first geostationary UVN mission. The SENTINEL 4 space segment will be integrated on EUMETSAT's Meteosat Third Generation Sounder satellite (MTG-S). Sentinel 4 will provide coverage of Europe and adjacent regions. The Sentinel 4 instrument comprises as a major element two Focal Plane Subsystems (FPS) covering the wavelength ranges 305 nm to 500 nm (UVVIS) and 750 nm to 775 nm (NIR) respectively. The paper describes the Focal Plane Subsystems, comprising the detectors, the optical bench and the control electronics. Further the design and development approach will be presented as well as first measurement results of FPS Qualification Model.

  13. Infrared detectors and focal plane arrays; Proceedings of the Meeting, Orlando, FL, Apr. 18, 19, 1990

    Science.gov (United States)

    Dereniak, Eustace L.; Sampson, Robert E.

    1990-09-01

    The papers contained in this volume provide an overview of recent advances and the current state of developments in the field of infrared detectors and focal plane arrays. Topics discussed include nickel silicide Schottky-barrier detectors for short-wavelength infrared applications; high performance PtSi linear and focal plane arrays; and multispectral band Schottky-barrier IRSSD for remote-sensing applications. Papers are also presented on the performance of an Insi hybrid focal array; characterization of IR focal plane test stations; GaAs CCD readout for engineered bandgap detectors; and fire detection system for aircraft cargo bays.

  14. Smart trigger logic for focal plane arrays

    Science.gov (United States)

    Levy, James E; Campbell, David V; Holmes, Michael L; Lovejoy, Robert; Wojciechowski, Kenneth; Kay, Randolph R; Cavanaugh, William S; Gurrieri, Thomas M

    2014-03-25

    An electronic device includes a memory configured to receive data representing light intensity values from pixels in a focal plane array and a processor that analyzes the received data to determine which light values correspond to triggered pixels, where the triggered pixels are those pixels that meet a predefined set of criteria, and determines, for each triggered pixel, a set of neighbor pixels for which light intensity values are to be stored. The electronic device also includes a buffer that temporarily stores light intensity values for at least one previously processed row of pixels, so that when a triggered pixel is identified in a current row, light intensity values for the neighbor pixels in the previously processed row and for the triggered pixel are persistently stored, as well as a data transmitter that transmits the persistently stored light intensity values for the triggered and neighbor pixels to a data receiver.

  15. An unified approach for the design of focal-plane arrays in satellite communication

    NARCIS (Netherlands)

    Zamanifekri, A.; Smolders, A.B.

    2012-01-01

    The aim of this paper is to present a hybrid approach for designing focal plane arrays using commercially available software, considering the fact that the main trade-off in the EM simulation is the accuracy versus computational power. The presented approach is hybrid method based on FDTD/PO. The

  16. Focal plane for the next generation of earth observation instruments

    Science.gov (United States)

    Pranyies, P.; Toubhans, I.; Badoil, B.; Tanguy, F.; Descours, Francis

    2017-09-01

    Sodern is the French focal plane provider for Earth Observation (EO) satellites. Since the 1980's, Sodern has played an active role first in the SPOT program. Within the two-spacecraft constellation Pleiades 1A/1B over the next years, Sodern introduced advanced technologies as Silicon Carbide (SiC) focal plane structure and multispectral strip filters dedicated to multiple-lines detectors.

  17. Thermomechanical architecture of the VIS focal plane for Euclid

    International Nuclear Information System (INIS)

    Martignac, Jerome; Carty, Michael; Tourette, Thierry; Bachet, Damien; Berthe, Michel; Augueres, Jean-Louis; Amiaux, Jerome; Fontignie, Jean; Horeau, Benoit; Renaud, Diana

    2014-01-01

    One of the main challenges for current and near future space experiments is the increase of focal plane complexity in terms of amount of pixels. In the frame work of the ESA Euclid mission to be launched in 2020, the Euclid Consortium is developing an extremely large and stable focal plane for the VIS instrument. CEA has developed the thermomechanical architecture of that Focal Plane taking into account all the very stringent performance and mission related requirements. The VIS Focal Plane Assembly integrates 36 CCDs (operated at 150 K) connected to their front end electronics (operated at 280 K) as to obtain one of the largest focal plane (0.6 billion pixels) ever built for space application after the GAIA one. The CCDs are CCD273 type specially designed and provided by the e2v company under ESA contract, front end electronics is studied and provided by MSSL. In this paper we first recall the specific requirements that have driven the overall architecture of the VIS-FPA and especially the solutions proposed to cope with the scientific needs of an extremely stable focal plane, both mechanically and thermally. The mechanical structure based on SiC material used for the cold sub assembly supporting the CCDs is detailed. We describe also the modular architecture concept that we have selected taking into account AIT-AIV and programmatic constraints. (authors)

  18. Electronics for a focal plane crystal spectrometer

    International Nuclear Information System (INIS)

    Goeke, R.F.

    1978-01-01

    The HEAO-B program forced the usual constraints upon the spacecraft experimental electronics: high reliability, low power consumption, and tight packaging at reasonable cost. The programmable high voltage power supplies were unique in both application and simplicity of manufacture. The hybridized measurement chain is a modification of that used on the SAS-C program; the charge amplifier design in particular shows definite improvement in performance over previous work

  19. Physical Limitations To Nonuniformity Correction In IR Focal Plane Arrays

    Science.gov (United States)

    Scribner, D. A.; Kruer, M. R.; Gridley, J. C.; Sarkady, K.

    1988-05-01

    Simple nonuniformity correction algorithms currently in use can be severely limited by nonlinear response characteristics of the individual pixels in an IR focal plane array. Although more complicated multi-point algorithms improve the correction process they too can be limited by nonlinearities. Furthermore, analysis of single pixel noise power spectrums usually show some level of 1 /f noise. This in turn causes pixel outputs to drift independent of each other thus causing the spatial noise (often called fixed pattern noise) of the array to increase as a function of time since the last calibration. Measurements are presented for two arrays (a HgCdTe hybrid and a Pt:Si CCD) describing pixel nonlinearities, 1/f noise, and residual spatial noise (after nonuniforming correction). Of particular emphasis is spatial noise as a function of the lapsed time since the last calibration and the calibration process selected. The resulting spatial noise is examined in terms of its effect on the NEAT performance of each array tested and comparisons are made. Finally, a discussion of implications for array developers is given.

  20. Modulation Transfer Function of Infrared Focal Plane Arrays

    Science.gov (United States)

    Gunapala, S. D.; Rafol, S. B.; Ting, D. Z.; Soibel, A.; Hill, C. J.; Khoshakhlagh, A.; Liu, J. K.; Mumolo, J. M.; Hoglund, L.; Luong, E. M.

    2015-01-01

    Modulation transfer function (MTF) is the ability of an imaging system to faithfully image a given object. The MTF of an imaging system quantifies the ability of the system to resolve or transfer spatial frequencies. In this presentation we will discuss the detail MTF measurements of 1024x1024 pixels mid -wavelength and long- wavelength quantum well infrared photodetector, and 320x256 pixels long- wavelength InAs/GaSb superlattice infrared focal plane arrays (FPAs). Long wavelength Complementary Barrier Infrared Detector (CBIRD) based on InAs/GaSb superlattice material is hybridized to recently designed and fabricated 320x256 pixel format ROIC. The n-type CBIRD was characterized in terms of performance and thermal stability. The experimentally measured NE delta T of the 8.8 micron cutoff n-CBIRD FPA was 18.6 mK with 300 K background and f/2 cold stop at 78K FPA operating temperature. The horizontal and vertical MTFs of this pixel fully delineated CBIRD FPA at Nyquist frequency are 49% and 52%, respectively.

  1. NeuroSeek dual-color image processing infrared focal plane array

    Science.gov (United States)

    McCarley, Paul L.; Massie, Mark A.; Baxter, Christopher R.; Huynh, Buu L.

    1998-09-01

    Several technologies have been developed in recent years to advance the state of the art of IR sensor systems including dual color affordable focal planes, on-focal plane array biologically inspired image and signal processing techniques and spectral sensing techniques. Pacific Advanced Technology (PAT) and the Air Force Research Lab Munitions Directorate have developed a system which incorporates the best of these capabilities into a single device. The 'NeuroSeek' device integrates these technologies into an IR focal plane array (FPA) which combines multicolor Midwave IR/Longwave IR radiometric response with on-focal plane 'smart' neuromorphic analog image processing. The readout and processing integrated circuit very large scale integration chip which was developed under this effort will be hybridized to a dual color detector array to produce the NeuroSeek FPA, which will have the capability to fuse multiple pixel-based sensor inputs directly on the focal plane. Great advantages are afforded by application of massively parallel processing algorithms to image data in the analog domain; the high speed and low power consumption of this device mimic operations performed in the human retina.

  2. A 1.3 giga pixels focal plane for GAIA

    Science.gov (United States)

    Laborie, Anouk; Pouny, Pierre; Vetel, Cyril; Collados, Emmanuel; Rougier, Gilles; Davancens, Robert; Zayer, Igor; Perryman, Michael; Pace, Oscar

    2004-06-01

    The astrometric mission GAIA is a cornerstone mission of the European Space Agency, due for launch in the 2010 time frame. Requiring extremely demanding performance GAIA calls for the development of an unprecedented large focal plane featuring innovative technologies. For securing the very challenging GAIA development, a significant number of technology activities have been initiated by ESA through a competitive selection process. In this context, an industrial consortium led by EADS-Astrium (France) with e2v technologies (UK) as major subcontractor was selected for the GAIA CCD and Focal Plane Technology Demonstrators programme, which is by far the most significant and the most critical GAIA pre-development for all aspects: science performance, development schedule and cost. This programme has started since August 2002 and will end early 2005 prior to commencement of the GAIA Phase B. While the GAIA payload will host three instruments and related focal planes, the major mission objectives are assigned to the Astrometric (ASTRO) Focal Plane, which is the subject of this presentation.

  3. Axial and focal-plane diffraction catastrophe integrals

    International Nuclear Information System (INIS)

    Berry, M V; Howls, C J

    2010-01-01

    Exact expressions in terms of Bessel functions are found for some of the diffraction catastrophe integrals that decorate caustics in optics and mechanics. These are the axial and focal-plane sections of the elliptic and hyperbolic umbilic diffraction catastrophes, and symmetric elliptic and hyperbolic unfoldings of the X 9 diffraction catastrophes. These representations reveal unexpected relations between the integrals.

  4. Quantum-Well Infrared Photodetector (QWIP) Focal Plane Assembly

    Science.gov (United States)

    Jhabvala, Murzy; Jhabvala, Christine A.; Ewin, Audrey J.; Hess, Larry A.; Hartmann, Thomas M.; La, Anh T.

    2012-01-01

    A paper describes the Thermal Infrared Sensor (TIRS), a QWIP-based instrument intended to supplement the Operational Land Imager (OLI) for the Landsat Data Continuity Mission (LDCM). The TIRS instrument is a far-infrared imager operating in the pushbroom mode with two IR channels: 10.8 and 12 microns. The focal plane will contain three 640x512 QWIP arrays mounted on a silicon substrate. The silicon substrate is a custom-fabricated carrier board with a single layer of aluminum interconnects. The general fabrication process starts with a 4-in. (approx.10-cm) diameter silicon wafer. The wafer is oxidized, a single substrate contact is etched, and aluminum is deposited, patterned, and alloyed. This technology development is aimed at incorporating three large-format infrared detecting arrays based on GaAs QWIP technology onto a common focal plane with precision alignment of all three arrays. This focal plane must survive the rigors of flight qualification and operate at a temperature of 43 K (-230 C) for five years while orbiting the Earth. The challenges presented include ensuring thermal compatibility among all the components, designing and building a compact, somewhat modular system and ensuring alignment to very tight levels. The multi-array focal plane integrated onto a single silicon substrate is a new application of both QWIP array development and silicon wafer scale integration. The Invar-based assembly has been tested to ensure thermal reliability.

  5. Automatic test comes to focal plane array production

    Science.gov (United States)

    Skaggs, Frank L.; Barton, T. D.

    1992-08-01

    To meet the needs of military and commercial markets, the infrared focal plane array industry must develop new, effective and low cost methods of fabricating and testing imaging detectors. This paper describes Texas Instruments new concepts in automated testing and cold probe technology as they apply to volume production.

  6. Position sensitive proportional counters as focal plane detectors

    International Nuclear Information System (INIS)

    Ford, J.L.C. Jr.

    1979-01-01

    The rise time and charge division techniques for position decoding with RC-line proportional counters are reviewed. The advantages that these detectors offer as focal plane counters for nuclear spectroscopy performed with magnetic spectrographs are discussed. The theory of operation of proportional counters as position sensing devices is summarized, as well as practical aspects affecting their application. Factors limiting the position and energy resolutions obtainable with a focal plane proportional counter are evaluated and measured position and energy loss values are presented for comparison. Detector systems capable of the multiparameter measurements required for particle identification, background suppression and ray-tracing are described in order to illustrate the wide applicability of proportional counters within complex focal plane systems. Examples of the use of these counters other than with magnetic spectrographs are given in order to demonstrate their usefulness in not only nuclear physics but also in fields such as solid state physics, biology, and medicine. The influence of the new focal plane detector systems on future magnetic spectrograph designs is discussed. (Auth.)

  7. Infrared detectors and focal plane arrays II; Proceedings of the Meeting, Orlando, FL, Apr. 23, 24, 1992

    Science.gov (United States)

    Dereniak, Eustace L.; Sampson, Robert E.

    The present conference discusses Schottky-barrier IR image sensors, SWIR and MWIR Schottky-barrier imagers, a 640 x 640 PtSi, models of nonlinearities in focal plane arrays, retinal function relative to IRT focal plane arrays, a solid-state pyroelectric imager, and electrolyte electroreflectance spectroscopies for the ion-implanted HgCdTe with thermal annealing. Also discussed are HgCdTe hybrid focal plane arrays for thermoelectrically cooled applications, a novel IR detector plasma-edge detector, and IR detector circuits using monolithic CMOS amps with InSb detectors. (No individual items are abstracted in this volume)

  8. METHOD FOR DETERMINATION OF FOCAL PLANE LOCATION OF FOCUSING COMPONENTS

    Directory of Open Access Journals (Sweden)

    A. I. Ivashko

    2017-01-01

    Full Text Available Mass-production of different laser systems often requires utilization of the focal spot size method for determination of output laser beam spatial characteristics. The main challenge of this method is high accuracy maintenance of a CCD camera beam profiler in the collecting lens focal plane. The aim of our work is development of new method for placing of photodetector array in the collecting lens focal plane with high accuracy.Proposed technique is based on focusing of several parallel laser beams. Determination of the focal plane position requires only longitudinal translation of the CCD-camera to find a point of laser beams intersection. Continuous-wave (CW diode-pumped laser emitting in the spectral region near 1μm was created to satisfy the requirements of the developed technique. Designed microchip laser generates two stigmatic Gaussian beams with automatically parallel beam axes due to independent pumping of different areas of the one microchip crystal having the same cavity mirrors.It was theoretically demonstrated that developed method provides possibility of the lenses focal plane determination with 1 % accuracy. The microchip laser generates two parallel Gaussian beams with divergence of about 10 mrad. Laser output power can be varied in the range of 0.1–1.5 W by changing the pumping laser diode electrical current. The distance between two beam axes can be changed in the range of 0.5–5.0 mm.We have proposed method for determination of positive lens focal plane location by using of CCDcamera and two laser beams with parallel axes without utilization of additional optical devices. We have developed CW longitudinally diode pumped microchip laser emitting in the 1-μm spectral region that can be used in the measuring instrument that doesn’t require precision mechanical components for determination of focal plane location with 1 % accuracy. The overall dimensions of laser head was 70 × 40 × 40 mm3 and maximum power consumption was

  9. Uncooled infrared focal plane array imaging in China

    Science.gov (United States)

    Lei, Shuyu

    2015-06-01

    This article reviews the development of uncooled infrared focal plane array (UIFPA) imaging in China in the past decade. Sensors based on optical or electrical read-out mechanism were developed but the latter dominates the market. In resistive bolometers, VOx and amorphous silicon are still the two major thermal-sensing materials. The specifications of the IRFPA made by different manufactures were collected and compared. Currently more than five Chinese companies and institutions design and fabricate uncooled infrared focal plane array. Some devices have sensitivity as high as 30 mK; the largest array for commercial products is 640×512 and the smallest pixel size is 17 μm. Emphasis is given on the pixel MEMS design, ROIC design, fabrication, and packaging of the IRFPA manufactured by GWIC, especially on design for high sensitivities, low noise, better uniformity and linearity, better stabilization for whole working temperature range, full-digital design, etc.

  10. Segmented focal plane detector for light and heavy ions

    International Nuclear Information System (INIS)

    Wolfs, F.L.H.; Bryan, D.C.; Kurz, K.L.; Herrick, D.M.; Perera, P.A.A.; White, C.A.

    1992-01-01

    A segmented focal plane detector for an Enge split-pole spectrograph has been developed for the study of breakup reactions at very low relative energies. It consists of a 61 cm long segmented position-sensitive parallel plate avalanche counter backed by a large Bragg curve detector. A segmented plastic scintillator is mounted behind the anode of the Bragg curve detector and is used for particle identification of low-ionizing particles. The dead space between the two sections of the focal plane detector is 2.5 mm. The intrinsic position resolution of the detector is 1 mm. The intrinsic energy resolution depends on the energy of the incident ion and can be as good as 0.55%. The nuclear charge and mass resolutions are 0.3 e and 0.3 u, respectively. (orig.)

  11. A focal plane detector for both light and heavy ions

    International Nuclear Information System (INIS)

    Ophel, T.R.; Johnston, A.

    1978-05-01

    The characteristics of a multi-element, ionization-type focal plane detector with an effective length of 53 cm have been evaluated for various ions ranging between protons and 32 S. The position resolution obtained is typically 1 mm. Excellent energy (0.49% for 16 O) and angular resolution (0.2 degrees with respect to beam direction for 7 Li) have been obtained enabling clean separation of ion species at essentially full angular acceptance of a split-pole spectrograph

  12. Achromatic Focal Plane Mask for Exoplanet Imaging Coronagraphy

    Science.gov (United States)

    Newman, Kevin Edward; Belikov, Ruslan; Guyon, Olivier; Balasubramanian, Kunjithapatham; Wilson, Dan

    2013-01-01

    Recent advances in coronagraph technologies for exoplanet imaging have achieved contrasts close to 1e10 at 4 lambda/D and 1e-9 at 2 lambda/D in monochromatic light. A remaining technological challenge is to achieve high contrast in broadband light; a challenge that is largely limited by chromaticity of the focal plane mask. The size of a star image scales linearly with wavelength. Focal plane masks are typically the same size at all wavelengths, and must be sized for the longest wavelength in the observational band to avoid starlight leakage. However, this oversized mask blocks useful discovery space from the shorter wavelengths. We present here the design, development, and testing of an achromatic focal plane mask based on the concept of optical filtering by a diffractive optical element (DOE). The mask consists of an array of DOE cells, the combination of which functions as a wavelength filter with any desired amplitude and phase transmission. The effective size of the mask scales nearly linearly with wavelength, and allows significant improvement in the inner working angle of the coronagraph at shorter wavelengths. The design is applicable to almost any coronagraph configuration, and enables operation in a wider band of wavelengths than would otherwise be possible. We include initial results from a laboratory demonstration of the mask with the Phase Induced Amplitude Apodization coronagraph.

  13. HIGH PERFORMANCE PIAA CORONAGRAPHY WITH COMPLEX AMPLITUDE FOCAL PLANE MASKS

    International Nuclear Information System (INIS)

    Guyon, Olivier; Martinache, Frantz; Belikov, Ruslan; Soummer, Remi

    2010-01-01

    We describe a coronagraph approach where the performance of a Phase-Induced Amplitude Apodization (PIAA) coronagraph is improved by using a partially transmissive phase-shifting focal plane mask and a Lyot stop. This approach combines the low inner working angle offered by phase mask coronagraphy, the full throughput and uncompromized angular resolution of the PIAA approach, and the design flexibility of Apodized Pupil Lyot Coronagraph. A PIAA complex mask coronagraph (PIAACMC) is fully described by the focal plane mask size, or, equivalently, its complex transmission which ranges from 0 (opaque) to -1 (phase shifting). For all values of the transmission, the PIAACMC theoretically offers full on-axis extinction and 100% throughput at large angular separations. With a pure phase focal plane mask (complex transmission = -1), the PIAACMC offers 50% throughput at 0.64 λ/D while providing total extinction of an on-axis point source. This performance is very close to the 'fundamental performance limit' of coronagraphy derived from first principles. For very high contrast level, imaging performance with PIAACMC is in practice limited by the angular size of the on-axis target (usually a star). We show that this fundamental limitation must be taken into account when choosing the optimal value of the focal plane mask size in the PIAACMC design. We show that the PIAACMC enables visible imaging of Jupiter-like planets at ∼1.2 λ/D from the host star, and can therefore offer almost three times more targets than a PIAA coronagraph optimized for this type of observation. We find that for visible imaging of Earth-like planets, the PIAACMC gain over a PIAA is probably much smaller, as coronagraphic performance is then strongly constrained by stellar angular size. For observations at 'low' contrast (below ∼ 10 8 ), the PIAACMC offers significant performance enhancement over PIAA. This is especially relevant for ground-based high contrast imaging systems in the near-IR, where

  14. Kalman Filter for Calibrating a Telescope Focal Plane

    Science.gov (United States)

    Kang, Bryan; Bayard, David

    2006-01-01

    The instrument-pointing frame (IPF) Kalman filter, and an algorithm that implements this filter, have been devised for calibrating the focal plane of a telescope. As used here, calibration signifies, more specifically, a combination of measurements and calculations directed toward ensuring accuracy in aiming the telescope and determining the locations of objects imaged in various arrays of photodetectors in instruments located on the focal plane. The IPF Kalman filter was originally intended for application to a spaceborne infrared astronomical telescope, but can also be applied to other spaceborne and ground-based telescopes. In the traditional approach to calibration of a telescope, (1) one team of experts concentrates on estimating parameters (e.g., pointing alignments and gyroscope drifts) that are classified as being of primarily an engineering nature, (2) another team of experts concentrates on estimating calibration parameters (e.g., plate scales and optical distortions) that are classified as being primarily of a scientific nature, and (3) the two teams repeatedly exchange data in an iterative process in which each team refines its estimates with the help of the data provided by the other team. This iterative process is inefficient and uneconomical because it is time-consuming and entails the maintenance of two survey teams and the development of computer programs specific to the requirements of each team. Moreover, theoretical analysis reveals that the engineering/ science iterative approach is not optimal in that it does not yield the best estimates of focal-plane parameters and, depending on the application, may not even enable convergence toward a set of estimates.

  15. Near infrared focal plane for the ISOCAM camera

    International Nuclear Information System (INIS)

    Epstein, G.; Stefanovitch, D.; Tiphene, D.; Carpentier, Y.; Lorans, D.

    1988-01-01

    ISOCAM is one of the science instruments in the Infrared Space Observatory. It is a 2-channel IR Astronomical Imager intended to observe at very low flux levels, thanks to the use of a liquid helium cooled telescope. This paper describes the Focal Plane Assembly design of the short wavelength channel. The operation of a 32 x 32 InSb CID-SAT array detector has been demonstrated. The problems encountered in the design of the cooled electronics and the component selection process are discussed in the light of specific ISO constraints, such as thermal control and radiation shielding. 6 references

  16. New focal plane detector system for the broad range spectrometer

    International Nuclear Information System (INIS)

    Sjoreen, T.P.

    1984-01-01

    A focal plane detector system consisting of a vertical drift chamber, parallel plate avalanche counters, and an ionization chamber with segmented anodes has been installed in the Broad Range Spectrometer at the Holifield Facility at Oak Ridge. The system, which has been designed for use with light-heavy ions with energies ranging from 10 to 25 MeV/amu, has a position resolution of approx. 0.1 mm, a scattering angle resolution of approx. 3 mrad, and a mass resolution of approx. 1/60

  17. Focal plane array with modular pixel array components for scalability

    Science.gov (United States)

    Kay, Randolph R; Campbell, David V; Shinde, Subhash L; Rienstra, Jeffrey L; Serkland, Darwin K; Holmes, Michael L

    2014-12-09

    A modular, scalable focal plane array is provided as an array of integrated circuit dice, wherein each die includes a given amount of modular pixel array circuitry. The array of dice effectively multiplies the amount of modular pixel array circuitry to produce a larger pixel array without increasing die size. Desired pixel pitch across the enlarged pixel array is preserved by forming die stacks with each pixel array circuitry die stacked on a separate die that contains the corresponding signal processing circuitry. Techniques for die stack interconnections and die stack placement are implemented to ensure that the desired pixel pitch is preserved across the enlarged pixel array.

  18. VERIFICATION OF THE SENTINEL-4 FOCAL PLANE SUBSYSTEM

    Directory of Open Access Journals (Sweden)

    C. Williges

    2017-05-01

    Full Text Available The Sentinel-4 payload is a multi-spectral camera system which is designed to monitor atmospheric conditions over Europe. The German Aerospace Center (DLR in Berlin, Germany conducted the verification campaign of the Focal Plane Subsystem (FPS on behalf of Airbus Defense and Space GmbH, Ottobrunn, Germany. The FPS consists, inter alia, of two Focal Plane Assemblies (FPAs, one for the UV-VIS spectral range (305 nm … 500 nm, the second for NIR (750 nm … 775 nm. In this publication, we will present in detail the opto-mechanical laboratory set-up of the verification campaign of the Sentinel-4 Qualification Model (QM which will also be used for the upcoming Flight Model (FM verification. The test campaign consists mainly of radiometric tests performed with an integrating sphere as homogenous light source. The FPAs have mainly to be operated at 215 K ± 5 K, making it necessary to exploit a thermal vacuum chamber (TVC for the test accomplishment. This publication focuses on the challenge to remotely illuminate both Sentinel-4 detectors as well as a reference detector homogeneously over a distance of approximately 1 m from outside the TVC. Furthermore selected test analyses and results will be presented, showing that the Sentinel-4 FPS meets specifications.

  19. High operating temperature interband cascade focal plane arrays

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Z.-B.; Godoy, S. E.; Kim, H. S.; Schuler-Sandy, T.; Montoya, J. A.; Krishna, S. [Center for High Technology Materials, Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, New Mexico 87106 (United States)

    2014-08-04

    In this paper, we report the initial demonstration of mid-infrared interband cascade (IC) photodetector focal plane arrays with multiple-stage/junction design. The merits of IC photodetectors include low noise and efficient photocarrier extraction, even for zero-bias operation. By adopting enhanced electron barrier design and a total absorber thickness of 0.7 μm, the 5-stage IC detectors show very low dark current (1.10 × 10{sup −7} A/cm{sup 2} at −5 mV and 150 K). Even with un-optimized fabrication and standard commercial (mis-matched) read-out circuit technology, infrared images are obtained by the 320 × 256 IC focal plane array up to 180 K with f/2.3 optics. The minimum noise equivalent temperature difference of 28 mK is obtained at 120 K. These initial results indicate great potential of IC photodetectors, particularly for high operating temperature applications.

  20. High operating temperature interband cascade focal plane arrays

    International Nuclear Information System (INIS)

    Tian, Z.-B.; Godoy, S. E.; Kim, H. S.; Schuler-Sandy, T.; Montoya, J. A.; Krishna, S.

    2014-01-01

    In this paper, we report the initial demonstration of mid-infrared interband cascade (IC) photodetector focal plane arrays with multiple-stage/junction design. The merits of IC photodetectors include low noise and efficient photocarrier extraction, even for zero-bias operation. By adopting enhanced electron barrier design and a total absorber thickness of 0.7 μm, the 5-stage IC detectors show very low dark current (1.10 × 10 −7 A/cm 2 at −5 mV and 150 K). Even with un-optimized fabrication and standard commercial (mis-matched) read-out circuit technology, infrared images are obtained by the 320 × 256 IC focal plane array up to 180 K with f/2.3 optics. The minimum noise equivalent temperature difference of 28 mK is obtained at 120 K. These initial results indicate great potential of IC photodetectors, particularly for high operating temperature applications

  1. Verification of the Sentinel-4 focal plane subsystem

    Science.gov (United States)

    Williges, Christian; Uhlig, Mathias; Hilbert, Stefan; Rossmann, Hannes; Buchwinkler, Kevin; Babben, Steffen; Sebastian, Ilse; Hohn, Rüdiger; Reulke, Ralf

    2017-09-01

    The Sentinel-4 payload is a multi-spectral camera system, designed to monitor atmospheric conditions over Europe from a geostationary orbit. The German Aerospace Center, DLR Berlin, conducted the verification campaign of the Focal Plane Subsystem (FPS) during the second half of 2016. The FPS consists, of two Focal Plane Assemblies (FPAs), two Front End Electronics (FEEs), one Front End Support Electronic (FSE) and one Instrument Control Unit (ICU). The FPAs are designed for two spectral ranges: UV-VIS (305 nm - 500 nm) and NIR (750 nm - 775 nm). In this publication, we will present in detail the set-up of the verification campaign of the Sentinel-4 Qualification Model (QM). This set up will also be used for the upcoming Flight Model (FM) verification, planned for early 2018. The FPAs have to be operated at 215 K +/- 5 K, making it necessary to exploit a thermal vacuum chamber (TVC) for the test accomplishment. The test campaign consists mainly of radiometric tests. This publication focuses on the challenge to remotely illuminate both Sentinel-4 detectors as well as a reference detector homogeneously over a distance of approximately 1 m from outside the TVC. Selected test analyses and results will be presented.

  2. Infrared focal plane array producibility and related materials; Proceedings of the Meeting, Orlando, FL, Apr. 20, 21, 1992

    Science.gov (United States)

    Balcerak, Ray; Pellegrini, Paul W.; Scribner, Dean A.

    The present conference discusses the commercial diversification of the U.S. IR detector industry's commercial diversification, HgCdTe focal-plane array (FPAs) manufacture, LPE of (Hg,Cd)Te FPAs, uncooled IR FPA detector producibility, a high performance staring IR camera, and novel technologies for FPA dewars. Also discussed are hybridizing FPAs, cryoprober test development, HgCdTe on Si for monolithic focal plane arrays, popcorn noise in linear InGaAs detector arrays, and the use of narrowband laser speckle for MTF characterization of CCDs. (No individual items are abstracted in this volume)

  3. Third-generation intelligent IR focal plane arrays

    Science.gov (United States)

    Caulfield, H. John; Jack, Michael D.; Pettijohn, Kevin L.; Schlesselmann, John D.; Norworth, Joe

    1998-03-01

    SBRC is at the forefront of industry in developing IR focal plane arrays including multi-spectral technology and '3rd generation' functions that mimic the human eye. 3rd generation devices conduct advanced processing on or near the FPA that serve to reduce bandwidth while performing needed functions such as automatic target recognition, uniformity correction and dynamic range enhancement. These devices represent a solution for processing the exorbitantly high bandwidth coming off large area FPAs without sacrificing systems sensitivity. SBRC's two-color approach leverages the company's HgCdTe technology to provide simultaneous multiband coverage, from short through long wave IR, with near theoretical performance. IR systems that are sensitive to different spectral bands achieve enhanced capabilities for target identification and advanced discrimination. This paper will provide a summary of the issues, the technology and the benefits of SBRC's third generation smart and two-color FPAs.

  4. Spatial noise in staring IR focal plane arrays

    International Nuclear Information System (INIS)

    Scribner, D.A.; Kruer, M.R.; Sarkady, K.; Gridley, J.C.

    1988-01-01

    Problems with nonuniformity correction algorithms due to nonlinear pixel response and 1/f noise have been shown previously to cause spatial noise which can be significantly greater than temporal noise. The residual spatial noise after correction cannot be reduced with time averaging. Because of spatial noise the sensitivity of staring FPA sensors is often less than predicted on the basis of the temporal noise of the individual elements. A review is given of methods for measuring and analyzing spatial noise (after nonuniformity correction) in staring infrared focal plane arrays. Automated measurement techniques are described briefly, including necessary equipment and data reduction procedures. An example of spatial noise measurements is given using a staring InSb Charge Injection Device (CID) array

  5. Focal plane based wavefront sensing with random DM probes

    Science.gov (United States)

    Pluzhnik, Eugene; Sirbu, Dan; Belikov, Ruslan; Bendek, Eduardo; Dudinov, Vladimir N.

    2017-09-01

    An internal coronagraph with an adaptive optical system for wavefront control is being considered for direct imaging of exoplanets with upcoming space missions and concepts, including WFIRST, HabEx, LUVOIR, EXCEDE and ACESat. The main technical challenge associated with direct imaging of exoplanets is to control of both diffracted and scattered light from the star so that even a dim planetary companion can be imaged. For a deformable mirror (DM) to create a dark hole with 10-10 contrast in the image plane, wavefront errors must be accurately measured on the science focal plane detector to ensure a common optical path. We present here a method that uses a set of random phase probes applied to the DM to obtain a high accuracy wavefront estimate even for a dynamically changing optical system. The presented numerical simulations and experimental results show low noise sensitivity, high reliability, and robustness of the proposed approach. The method does not use any additional optics or complex calibration procedures and can be used during the calibration stage of any direct imaging mission. It can also be used in any optical experiment that uses a DM as an active optical element in the layout.

  6. Corrugated Quantum Well Infrared Photodetector Focal Plane Array Test Results

    Science.gov (United States)

    Goldberg, A.; Choi, K. K.; Das, N. C.; La, A.; Jhabvala, M.

    1999-01-01

    The corrugated quantum-well infrared photodetector (C-QWIP) uses total internal reflection to couple normal incident light into the optically active quantum wells. The coupling efficiency has been shown to be relatively independent of the pixel size and wavelength thus making the C-QWIP a candidate for detectors over the entire infrared spectrum. The broadband coupling efficiency of the C-QWIP makes it an ideal candidate for multiwavelength detectors. We fabricated and tested C-QWIP focal plane arrays (FPAs) with cutoff wavelengths of 11.2 and 16.2 micrometers. Each FPA has 256 x 256 pixels that are bump-bonded to a direct injection readout circuit. Both FPAs provided infrared imagery with good aesthetic attributes. For the 11.2-micrometers FPA, background-limited performance (BLIP) was observed at 60 K with f/3 optics. For the 16.2-micrometers FPA, BLIP was observed at 38 K. Besides the reduction of dark current in C-QWIP structures, the measured internal quantum efficiency (eta) remains to be high. The values for responsivity and quantum efficiency obtained from the FPA results agree well with those measured for single devices.

  7. Cosmology Large Angular Scale Surveyor (CLASS) Focal Plane Development

    Science.gov (United States)

    Chuss, D. T.; Ali, A.; Amiri, M.; Appel, J.; Bennett, C. L.; Colazo, F.; Denis, K. L.; Dunner, R.; Essinger-Hileman, T.; Eimer, J.; hide

    2015-01-01

    The Cosmology Large Angular Scale Surveyor (CLASS) will measure the polarization of the Cosmic Microwave Background to search for and characterize the polarized signature of inflation. CLASS will operate from the Atacama Desert and observe approx.70% of the sky. A variable-delay polarization modulator provides modulation of the polarization at approx.10Hz to suppress the 1/f noise of the atmosphere and enable the measurement of the large angular scale polarization modes. The measurement of the inflationary signal across angular scales that spans both the recombination and reionization features allows a test of the predicted shape of the polarized angular power spectra in addition to a measurement of the energy scale of inflation. CLASS is an array of telescopes covering frequencies of 38, 93, 148, and 217 GHz. These frequencies straddle the foreground minimum and thus allow the extraction of foregrounds from the primordial signal. Each focal plane contains feedhorn-coupled transition-edge sensors that simultaneously detect two orthogonal linear polarizations. The use of single-crystal silicon as the dielectric for the on-chip transmission lines enables both high efficiency and uniformity in fabrication. Integrated band definition has been implemented that both controls the bandpass of the single-mode transmission on the chip and prevents stray light from coupling to the detectors.

  8. A Micromachined Infrared Senor for an Infrared Focal Plane Array

    Directory of Open Access Journals (Sweden)

    Seong M. Cho

    2008-04-01

    Full Text Available A micromachined infrared sensor for an infrared focal plane array has been designed and fabricated. Amorphous silicon was used as a sensing material, and silicon nitride was used as a membrane material. To get a good absorption in infrared range, the sensor structure was designed as a l/4 cavity structure. A Ni-Cr film was selected as an electrode material and mixed etching scheme was applied in the patterning process of the Ni-Cr electrode. All the processes were made in 0.5 μm iMEMS fabricated in the Electronics and Telecommunication Research Institute (ETRI. The processed MEMS sensor had a small membrane deflection less than 0.15 μm. This small deflection can be attributed to the rigorous balancing of the stresses of individual layers. The efficiency of infrared absorption was more than 75% in the wavelength range of 8 ~ 14 μm. The processed infrared sensor showed high responsivity of ~230 kV/W at 1.0V bias and 2 Hz operation condition. The time constant of the sensor was 8.6 msec, which means that the sensor is suitable to be operated in 30 Hz frame rate.

  9. Performance overview of the Euclid infrared focal plane detector subsystems

    Science.gov (United States)

    Waczynski, A.; Barbier, R.; Cagiano, S.; Chen, J.; Cheung, S.; Cho, H.; Cillis, A.; Clémens, J.-C.; Dawson, O.; Delo, G.; Farris, M.; Feizi, A.; Foltz, R.; Hickey, M.; Holmes, W.; Hwang, T.; Israelsson, U.; Jhabvala, M.; Kahle, D.; Kan, Em.; Kan, Er.; Loose, M.; Lotkin, G.; Miko, L.; Nguyen, L.; Piquette, E.; Powers, T.; Pravdo, S.; Runkle, A.; Seiffert, M.; Strada, P.; Tucker, C.; Turck, K.; Wang, F.; Weber, C.; Williams, J.

    2016-07-01

    In support of the European space agency (ESA) Euclid mission, NASA is responsible for the evaluation of the H2RG mercury cadmium telluride (MCT) detectors and electronics assemblies fabricated by Teledyne imaging systems. The detector evaluation is performed in the detector characterization laboratory (DCL) at the NASA Goddard space flight center (GSFC) in close collaboration with engineers and scientists from the jet propulsion laboratory (JPL) and the Euclid project. The Euclid near infrared spectrometer and imaging photometer (NISP) will perform large area optical and spectroscopic sky surveys in the 0.9-2.02 μm infrared (IR) region. The NISP instrument will contain sixteen detector arrays each coupled to a Teledyne SIDECAR application specific integrated circuit (ASIC). The focal plane will operate at 100K and the SIDECAR ASIC will be in close proximity operating at a slightly higher temperature of 137K. This paper will describe the test configuration, performance tests and results of the latest engineering run, also known as pilot run 3 (PR3), consisting of four H2RG detectors operating simultaneously. Performance data will be presented on; noise, spectral quantum efficiency, dark current, persistence, pixel yield, pixel to pixel uniformity, linearity, inter pixel crosstalk, full well and dynamic range, power dissipation, thermal response and unit cell input sensitivity.

  10. Focal plane mechanical design of the NISP/Euclid instrument

    Science.gov (United States)

    Bonnefoi, Anne; Bon, William; Niclas, Mathieu; Solheim, Bjarte G. B.; Torvanger, Oyvind; Schistad, Robert; Foulon, Benjamin; Garcia, José; Vives, Sébastien

    2016-07-01

    Currently in phase C, the Euclid mission selected by ESA in the Cosmic Vision program is dedicated to understand dark energy and dark matter. NISP (standing for Near Infrared Spectro-Photometer) is one of the two instruments of the mission. NISP will combine a photometer and a spectrometer working in the near-IR (0.9-2 microns). Its detection subsystem (called NI-DS) is based on a mosaic of 16 IR detectors cooled down to 90K which are supported by a molybdenum plate. The front-end readout electronics (working at 130K) are supported by another structure in Aluminum. The NI-DS is mounted on the rest of the instrument thanks to a panel in Silicon Carbide (SiC). Finally an optical baffle in Titanium will prevent the rogue light to reach the detectors. On top of the complexity due to the wide range of temperatures and the various materials imposed at the interfaces; the NI-DS has also to incorporate an internal adjustment capability of the position of the focal plane in tip/tilt and focus. This article will present current status of the development of the detection system of NISP.

  11. Fabrication of X-ray Microcalorimeter Focal Planes Composed of Two Distinct Pixel Types

    Science.gov (United States)

    Wassell, Edward J.; Adams, Joseph S.; Bandler, Simon R.; Betancour-Martinez, Gabriele L; Chiao, Meng P.; Chang, Meng Ping; Chervenak, James A.; Datesman, Aaron M.; Eckart, Megan E.; Ewin, Audrey J.; hide

    2016-01-01

    We develop superconducting transition-edge sensor (TES) microcalorimeter focal planes for versatility in meeting the specifications of X-ray imaging spectrometers, including high count rate, high energy resolution, and large field of view. In particular, a focal plane composed of two subarrays: one of fine pitch, high count-rate devices and the other of slower, larger pixels with similar energy resolution, offers promise for the next generation of astrophysics instruments, such as the X-ray Integral Field Unit Instrument on the European Space Agencys ATHENA mission. We have based the subarrays of our current design on successful pixel designs that have been demonstrated separately. Pixels with an all-gold X-ray absorber on 50 and 75 micron pitch, where the Mo/Au TES sits atop a thick metal heatsinking layer, have shown high resolution and can accommodate high count rates. The demonstrated larger pixels use a silicon nitride membrane for thermal isolation, thinner Au, and an added bismuth layer in a 250-sq micron absorber. To tune the parameters of each subarray requires merging the fabrication processes of the two detector types. We present the fabrication process for dual production of different X-ray absorbers on the same substrate, thick Au on the small pixels and thinner Au with a Bi capping layer on the larger pixels to tune their heat capacities. The process requires multiple electroplating and etching steps, but the absorbers are defined in a single-ion milling step. We demonstrate methods for integrating the heatsinking of the two types of pixel into the same focal plane consistent with the requirements for each subarray, including the limiting of thermal crosstalk. We also discuss fabrication process modifications for tuning the intrinsic transition temperature (T(sub c)) of the bilayers for the different device types through variation of the bilayer thicknesses. The latest results on these 'hybrid' arrays will be presented.

  12. Dual-layer electrode-driven liquid crystal lens with electrically tunable focal length and focal plane

    Science.gov (United States)

    Zhang, Y. A.; Lin, C. F.; Lin, J. P.; Zeng, X. Y.; Yan, Q.; Zhou, X. T.; Guo, T. L.

    2018-04-01

    Electric-field-driven liquid crystal (ELC) lens with tunable focal length and their depth of field has been extensively applied in 3D display and imaging systems. In this work, a dual-layer electrode-driven liquid crystal (DELC) lens with electrically tunable focal length and controllable focal plane is demonstrated. ITO-SiO2-AZO electrodes with the dual-layer staggered structure on the top substrate are used as driven electrodes within a LC cell, which permits the establishment of an alternative controllability. The focal length of the DELC lens can be adjusted from 1.41 cm to 0.29 cm when the operating voltage changes from 15 V to 40 V. Furthermore, the focal plane of the DELC lens can selectively move by changing the driving method of the applied voltage to the next driven electrodes. This work demonstrates that the DELC lens has potential applications in imaging systems because of electrically tunable focal length and controllable focal plane.

  13. Detectors and focal plane modules for weather satellites

    Science.gov (United States)

    D'Souza, A. I.; Robinson, E.; Masterjohn, S.; Ely, P.; Khalap, V.; Babu, S.; Smith, D. S.

    2016-05-01

    Weather satellite instruments require detectors with a variety of wavelengths ranging from the visible to VLWIR. One of the remote sensing applications is the geostationary GOES-ABI imager covering wavelengths from the 450 to 490 nm band through the 13.0 to 13.6 μm band. There are a total of 16 spectral bands covered. The Cross-track infrared Sounder (CrIS) is a Polar Orbiting interferometric sensor that measures earth radiances at high spectral resolution, using the data to provide pressure, temperature and moisture profiles of the atmosphere. The pressure, temperature and moisture sounding data are used in weather prediction models that track storms, predict levels of precipitation etc. The CrIS instrument contains SWIR (λc ~ 5 μm at 98K), MWIR (λc ~ 9 μm at 98K) and LWIRs (λc ~ 15.5 μm at 81K) bands in three Focal Plane Array Assemblies (FPAAs). GOES-ABI contains three focal plane modules (FPMs), (i) a visible-near infrared module consisting of three visible and three near infrared channels, (ii) a MWIR module comprised of five channels from 3.9 μm to 8.6 μm and (iii) a 9.6 μm to 13.3 μm, five-channel LWIR module. The VNIR FPM operates at 205 K, and the MWIR and LWIR FPMs operate at 60 K. Each spectral channel has a redundant array built into a single detector chip. Switching is thus permitted from the primary selected array in each channel to the redundant array, given any degradation in performance of the primary array during the course of the mission. Silicon p-i-n detectors are used for the 0.47 μm to 0.86 μm channels. The thirteen channels above 1 μm are fabricated in various compositions of Hg1-xCdxTe, and in this particular case using two different detector architectures. The 1.38 μm to 9.61 μm channels are all fabricated in Hg1-xCdxTe grown by Liquid Phase Epitaxy (LPE) using the HDVIP detector architecture. Molecular beam epitaxy (MBE)-grown Hg1-xCdxTe material are used for the LWIR 10.35 μm to 13.3 μm channels fabricated in Double

  14. Focal plane array based infrared thermography in fine physical experiment

    International Nuclear Information System (INIS)

    Vainer, Boris G

    2008-01-01

    By two examples of dissimilar physical phenomena causing thermophysical effects, the unique capabilities of one of the up-to-date methods of experimental physics-focal plane array (FPA) based infrared (IR) thermography (IRT), are demonstrated distinctly. Experimenters inexperienced in IRT can grasp how this method provides a means for combining real-time visualization with quantitative analysis. A narrow-band short-wavelength IR camera was used in the experiments. It is discussed and stated that IRT is best matched and suited to the next two test conditions-when a heated specimen is thin and when heat is generated in the immediate region of a surface of a solid. The first prerequisite is realized in the search for directional patterns of combined low-power radiation sources with the use of the IRT-aided method. The second one is realized in studies of water vapour adsorption on uneven (irregular) surfaces of solid materials. With multiple swatches taken from a set of different fabrics and used as experimental samples, a sharp distinction between adsorptivities of their surfaces is strikingly illustrated by IRT time-domain measurements exhibiting the associated thermal effect ranging within an order of magnitude. It is justified that the described IRT-aided test can find practical implementation at least in the light industry. Emissivities of different fabrics are evaluated experimentally with the described reflection method based on the narrow spectral range of IRT. On the basis of direct IR observations, attention is paid to the need for close control over the surface temperature increase while the adsorption isotherms are being measured. Sensitivity of the FPA-based IRT method, as applied to examine the kinetics of initial stages of adsorption of gaseous molecules on the solid surface, is evaluated analytically and quantitatively. The relationship between the amount of adsorbate and the measurable excess of adsorbent temperature is found. It is discovered that

  15. Technology for advanced focal plane arrays of HgCdTe and AIGaN

    CERN Document Server

    He, Li; Ni, Guoqiang

    2016-01-01

    This book introduces the basic framework of advanced focal plane technology based on the third-generation infrared focal plane concept. The essential concept, research advances, and future trends in advanced sensor arrays are comprehensively reviewed. Moreover, the book summarizes recent research advances in HgCdTe/AlGaN detectors for the infrared/ultraviolet waveband, with a particular focus on the numerical method of detector design, material epitaxial growth and processing, as well as Complementary Metal-Oxide-Semiconductor Transistor readout circuits. The book offers a unique resource for all graduate students and researchers interested in the technologies of focal plane arrays or electro-optical imaging sensors.

  16. Neuromorphic infrared focal plane performs sensor fusion on-plane local-contrast-enhancement spatial and temporal filtering

    Science.gov (United States)

    Massie, Mark A.; Woolaway, James T., II; Curzan, Jon P.; McCarley, Paul L.

    1993-08-01

    An infrared focal plane has been simulated, designed and fabricated which mimics the form and function of the vertebrate retina. The `Neuromorphic' focal plane has the capability of performing pixel-based sensor fusion and real-time local contrast enhancement, much like the response of the human eye. The device makes use of an indium antimonide detector array with a 3 - 5 micrometers spectral response, and a switched capacitor resistive network to compute a real-time 2D spatial average. This device permits the summation of other sensor outputs to be combined on-chip with the infrared detections of the focal plane itself. The resulting real-time analog processed information thus represents the combined information of many sensors with the advantage that analog spatial and temporal signal processing is performed at the focal plane. A Gaussian subtraction method is used to produce the pixel output which when displayed produces an image with enhanced edges, representing spatial and temporal derivatives in the scene. The spatial and temporal responses of the device are tunable during operation, permitting the operator to `peak up' the response of the array to spatial and temporally varying signals. Such an array adapts to ambient illumination conditions without loss of detection performance. This paper reviews the Neuromorphic infrared focal plane from initial operational simulations to detailed design characteristics, and concludes with a presentation of preliminary operational data for the device as well as videotaped imagery.

  17. Hydrogenation of Very Long Wavelength Infrared Focal Plane Arrays Based on Type II Superlattices, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to advance the Ga-free InAs/InAsSb type II superlattice (T2SL) materials technology for very long wavelength infrared (VLWIR) focal plane arrays (FPAs) by...

  18. Hyperspectral Longwave Infrared Focal Plane Array and Camera Based on Quantum Well Infrared Photodetectors, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a hyperspectral focal plane array and camera imaging in a large number of sharp hyperspectral bands in the thermal infrared. The camera is...

  19. High Resolution, Radiation Tolerant Focal Plane Array for Lunar And Deep Space Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Aerius Photonics and its partners propose the development of a high resolution, radiation hardened 3-D FLASH Focal Plane Array (FPA), with performance expected to be...

  20. Next generation sub-millimeter wave focal plane array coupling concepts: an ESA TRP project to develop multichroic focal plane pixels for future CMB polarization experiments

    Science.gov (United States)

    Trappe, N.; Bucher, M.; De Bernardis, P.; Delabrouille, J.; Deo, P.; DePetris, M.; Doherty, S.; Ghribi, A.; Gradziel, M.; Kuzmin, L.; Maffei, B.; Mahashabde, S.; Masi, S.; Murphy, J. A.; Noviello, F.; O'Sullivan, C.; Pagano, L.; Piacentini, F.; Piat, M.; Pisano, G.; Robinson, M.; Stompor, R.; Tartari, A.; van der Vorst, M.; Verhoeve, P.

    2016-07-01

    The main objective of this activity is to develop new focal plane coupling array concepts and technologies that optimise the coupling from reflector optics to the large number of detectors for next generation sub millimetre wave telescopes particularly targeting measurement of the polarization of the cosmic microwave background (CMB). In this 18 month TRP programme the consortium are tasked with developing, manufacturing and experimentally verifying a prototype multichroic pixel which would be suitable for the large focal plane arrays which will be demanded to reach the required sensitivity of future CMB polarization missions. One major development was to have multichroic operation to potentially reduce the required focal plane size of a CMB mission. After research in the optimum telescope design and definition of requirements based on a stringent science case review, a number of compact focal plane architecture concepts were investigated before a pixel demonstrator consisting of a planar mesh lens feeding a backend Resonant Cold Electron Bolometer RCEB for filtering and detection of the dual frequency signal was planned for manufacture and test. In this demonstrator the frequencies of the channels was chosen to be 75 and 105 GHz in the w band close to the peak CMB signal. In the next year the prototype breadboards will be developed to test the beams produced by the manufactured flat lenses fed by a variety of antenna configurations and the spectral response of the RCEBs will also be verified.

  1. Focal plane detector for QDD spectrography in Institute of Nuclear Study and detector for SMART 2nd focal plane in RIKEN

    Energy Technology Data Exchange (ETDEWEB)

    Fuchi, Yoshihide [Tokyo Univ., Tanashi (Japan). Inst. for Nuclear Study

    1996-09-01

    The focal plane detector for QDD spectrography in Institute of Nuclear Study was composed of drift space and a proportional counter tube, and the latter is composed of position detector and two delta E detector for recognizing the particles. In this detector, a uniform parallel electric field can be obtained by placing a guard plate at the same height as that of a drift plate outer place of the detector. On the other hand, the detector for SMART 2nd focal plate in RIKEN is composed of drift space and a single wire proportional counter, and has two cathode read out single wire drift counters set so as to hold the focal plane. (G.K.)

  2. Performance of an Achromatic Focal Plane Mask for Exoplanet Imaging Coronagraphy

    Science.gov (United States)

    Newman, Kevin; Belikov, Ruslan; Pluzhnik, Eugene; Balasubramanian, Kunjithapatham; Wilson, Dan

    2014-01-01

    Coronagraph technology combined with wavefront control is close to achieving the contrast and inner working angle requirements in the lab necessary to observe the faint signal of an Earth-like exoplanet in monochromatic light. An important remaining technological challenge is to achieve high contrast in broadband light. Coronagraph bandwidth is largely limited by chromaticity of the focal plane mask, which is responsible for blocking the stellar PSF. The size of a stellar PSF scales linearly with wavelength; ideally, the size of the focal plane mask would also scale with wavelength. A conventional hard-edge focal plane mask has a fixed size, normally sized for the longest wavelength in the observational band to avoid starlight leakage. The conventional mask is oversized for shorter wavelengths and blocks useful discovery space. Recently we presented a solution to the size chromaticity challenge with a focal plane mask designed to scale its effective size with wavelength. In this paper, we analyze performance of the achromatic size-scaling focal plane mask within a Phase Induced Amplitude Apodization (PIAA) coronagraph. We present results from wavefront control around the achromatic focal plane mask, and demonstrate the size-scaling effect of the mask with wavelength. The edge of the dark zone, and therefore the inner working angle of the coronagraph, scale with wavelength. The achromatic mask enables operation in a wider band of wavelengths compared with a conventional hard-edge occulter.

  3. Shared Focal Plane Investigation for Serial Frame Cameras.

    Science.gov (United States)

    1980-03-01

    capability will be restored. 41. -.. TrABLE 1-1 SYSTEM LEADING P) ARTICULARS Lens Focal Length (inches) Range (ft) Contrast 12 18 24 Coverage 22.1...can be expected that signature bands will be apparent in the imagery. Such bands are at best distracting and at worst hindrances to image interpretation

  4. Continuous contour phase plates for tailoring the focal plane irradiance profile

    International Nuclear Information System (INIS)

    Dixit, S.N.; Rushford, M.C.; Thomas, I.M.; Perry, M.D.

    1995-01-01

    We present fully continuous phase screens for producing super-Gaussian focal-plane irradiance profiles. Such phase screens are constructed with the assumption of either circular symmetric near-field and far-field profiles or a separable phase screen in Cartesian co-ordinates. In each case, the phase screen is only a few waves deep. Under illumination by coherent light, such phase screens produce high order super-Gaussian profiles in the focal plane with high energy content effects of beam aberrations on the focal profiles and their energy content are also discussed

  5. Hybrid inflation in the complex plane

    International Nuclear Information System (INIS)

    Buchmueller, W.; Domcke, V.; Kamada, K.; Schmitz, K.

    2014-04-01

    Supersymmetric hybrid inflation is an exquisite framework to connect inflationary cosmology to particle physics at the scale of grand unification. Ending in a phase transition associated with spontaneous symmetry breaking, it can naturally explain the generation of entropy, matter and dark matter. Coupling F-term hybrid inflation to soft supersymmetry breaking distorts the rotational invariance in the complex inflaton plane - an important fact, which has been neglected in all previous studies. Based on the δN formalism, we analyze the cosmological perturbations for the first time in the full two-field model, also taking into account the fast-roll dynamics at and after the end of inflation. As a consequence of the two-field nature of hybrid inflation, the predictions for the primordial fluctuations depend not only on the parameters of the Lagrangian, but are eventually fixed by the choice of the inflationary trajectory. Recognizing hybrid inflation as a two-field model resolves two shortcomings often times attributed to it: The fine-tuning problem of the initial conditions is greatly relaxed and a spectral index in accordance with the PLANCK data can be achieved in a large part of the parameter space without the aid of supergravity corrections. Our analysis can be easily generalized to other (including large-field) scenarios of inflation in which soft supersymmetry breaking transforms an initially single-field model into a multi-field model.

  6. Materials, devices, techniques, and applications for Z-plane focal plane array technology; Proceedings of the Meeting, Orlando, FL, Mar. 29, 30, 1989

    Science.gov (United States)

    Carson, John C.

    1989-09-01

    The papers contained in this volume focus on the implementation and application of Z-plane focal array technology. Topics discussed include civil and military applications of Z-plane technology, electronic design and technology for on-scale plane signal processing, detector development and fabrication technology, and Z-plane module development and producibility. Papers are presented on future capabilities of Z-plane technology, comparison of planar and Z-plane focal plane technologies for dim target detection, Z-plane modules as target extraction engines, and high complexity tape automated bonding application for space hardware.

  7. Focal plane AIT sequence: evolution from HRG-Spot 5 to Pleiades HR

    Science.gov (United States)

    Le Goff, Roland; Pranyies, Pascal; Toubhans, Isabelle

    2017-11-01

    Optical and geometrical image qualities of Focal Planes, for "push-broom" high resolution remote sensing satellites, require the implementation of specific means and methods for the AIT sequence. Indeed the geometric performances of the focal plane mainly axial focusing and transverse registration, are duly obtained on the basis of adjustment, setting and measurement of optical and CCD components with an accuracy of a few microns. Since the end of the 1970s, EADS-SODERN has developed a series of detection units for earth observation instruments like SPOT and Helios. And EADS-SODERN is now responsible for the development of the Pleiades High Resolution Focal Plane assembly. This paper presents the AIT sequences. We introduce all the efforts, innovative solutions and improvements made on the assembly facilities to match the technical evolutions and breakthrough of the Pleiades HR FP concept in comparison with the previous High Resolution Geometric SPOT 5 Focal Plane. The main evolution drivers are the implementation of strip filters and the realization of 400 mm continuous retinas. For Pleiades HR AIT sequence, three specific integration and measuring benches, corresponding with the different assembly stages, are used: a 3-D non-contact measurement machine for the assembly of detection module, a 3-D measurement machine for mirror integration on the main Focal Plane SiC structure, and a 3-D geometric coordinates control bench to focus detection module lines and to ensure they are well registered together.

  8. Fabrication of a Cryogenic Bias Filter for Ultrasensitive Focal Plane

    Science.gov (United States)

    Chervenak, James; Wollack, Edward

    2012-01-01

    A fabrication process has been developed for cryogenic in-line filtering for the bias and readout of ultrasensitive cryogenic bolometers for millimeter and submillimeter wavelengths. The design is a microstripline filter that cuts out, or strongly attenuates, frequencies (10 50 GHz) that can be carried by wiring staged at cryogenic temperatures. The filter must have 100-percent transmission at DC and low frequencies where the bias and readout lines will carry signal. The fabrication requires the encapsulation of superconducting wiring in a dielectric-metal envelope with precise electrical characteristics. Sufficiently thick insulation layers with high-conductivity metal layers fully surrounding a patterned superconducting wire in arrayable formats have been demonstrated. A degenerately doped silicon wafer has been chosen to provide a metallic ground plane. A metallic seed layer is patterned to enable attachment to the ground plane. Thick silicon dioxide films are deposited at low temperatures to provide tunable dielectric isolation without degrading the metallic seed layer. Superconducting wiring is deposited and patterned using microstripline filtering techniques to cut out the relevant frequencies. A low Tc superconductor is used so that it will attenuate power strongly above the gap frequency. Thick dielectric is deposited on top of the circuit, and then vias are patterned through both dielectric layers. A thick conductive film is deposited conformally over the entire circuit, except for the contact pads for the signal and bias attachments to complete the encapsulating ground plane. Filters are high-aspect- ratio rectangles, allowing close packing in one direction, while enabling the chip to feed through the wall of a copper enclosure. The chip is secured in the copper wall using a soft metal seal to make good thermal and electrical contact to the outer shield.

  9. Fabrication of Transition Edge Sensor Microcalorimeters for X-Ray Focal Planes

    Science.gov (United States)

    Chervenak, James A.; Adams, Joseph S.; Audley, Heather; Bandler, Simon R.; Betancourt-Martinez, Gabriele; Eckart, Megan E.; Finkbeiner, Fred M.; Kelley, Richard L.; Kilbourne, Caroline; Lee, Sang Jun; hide

    2015-01-01

    Requirements for focal planes for x-ray astrophysics vary widely depending on the needs of the science application such as photon count rate, energy band, resolving power, and angular resolution. Transition edge sensor x-ray calorimeters can encounter limitations when optimized for these specific applications. Balancing specifications leads to choices in, for example, pixel size, thermal sinking arrangement, and absorber thickness and material. For the broadest specifications, instruments can benefit from multiple pixel types in the same array or focal plane. Here we describe a variety of focal plane architectures that anticipate science requirements of x-ray instruments for heliophysics and astrophysics. We describe the fabrication procedures that enable each array and explore limitations for the specifications of such arrays, including arrays with multiple pixel types on the same array.

  10. Resonant detectors and focal plane arrays for infrared detection

    Science.gov (United States)

    Choi, K. K.; Allen, S. C.; Sun, J. G.; DeCuir, E. A.

    2017-08-01

    We are developing resonator-QWIPs for narrowband and broadband long wavelength infrared detection. Detector pixels with 25 μm and 30 μm pitches were hybridized to fanout circuits and readout integrated electronics for radiometric measurements. With a low to moderate doping of 0.2-0.5 × 1018 cm-3 and a thin active layer thickness of 0.6-1.3 μm, we achieved a quantum efficiency between 25 and 37% and a conversion efficiency between of 15 and 20%. The temperature at which photocurrent equals dark current is about 65 K under F/2 optics for a cutoff wavelength up to 11 μm. The NEΔT of the FPAs is estimated to be 20 mK at 2 ms integration time and 60 K operating temperature. This good performance confirms the advantages of the resonator-QWIP approach.

  11. Large-format InGaAs focal plane arrays for SWIR imaging

    Science.gov (United States)

    Hood, Andrew D.; MacDougal, Michael H.; Manzo, Juan; Follman, David; Geske, Jonathan C.

    2012-06-01

    FLIR Electro Optical Components will present our latest developments in large InGaAs focal plane arrays, which are used for low light level imaging in the short wavelength infrared (SWIR) regime. FLIR will present imaging from their latest small pitch (15 μm) focal plane arrays in VGA and High Definition (HD) formats. FLIR will present characterization of the FPA including dark current measurements as well as the use of correlated double sampling to reduce read noise. FLIR will show imagery as well as FPA-level characterization data.

  12. Measuring the Flatness of Focal Plane for Very Large Mosaic CCD Camera

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Jiangang; Estrada, Juan; Cease, Herman; Diehl, H.Thomas; Flaugher, Brenna L.; Kubik, Donna; Kuk, Keivin; Kuropatkine, Nickolai; Lin, Huan; Montes, Jorge; Scarpine, Vic; /Fermilab

    2010-06-08

    Large mosaic multiCCD camera is the key instrument for modern digital sky survey. DECam is an extremely red sensitive 520 Megapixel camera designed for the incoming Dark Energy Survey (DES). It is consist of sixty two 4k x 2k and twelve 2k x 2k 250-micron thick fully-depleted CCDs, with a focal plane of 44 cm in diameter and a field of view of 2.2 square degree. It will be attached to the Blanco 4-meter telescope at CTIO. The DES will cover 5000 square-degrees of the southern galactic cap in 5 color bands (g, r, i, z, Y) in 5 years starting from 2011. To achieve the science goal of constraining the Dark Energy evolution, stringent requirements are laid down for the design of DECam. Among them, the flatness of the focal plane needs to be controlled within a 60-micron envelope in order to achieve the specified PSF variation limit. It is very challenging to measure the flatness of the focal plane to such precision when it is placed in a high vacuum dewar at 173 K. We developed two image based techniques to measure the flatness of the focal plane. By imaging a regular grid of dots on the focal plane, the CCD offset along the optical axis is converted to the variation the grid spacings at different positions on the focal plane. After extracting the patterns and comparing the change in spacings, we can measure the flatness to high precision. In method 1, the regular dots are kept in high sub micron precision and cover the whole focal plane. In method 2, no high precision for the grid is required. Instead, we use a precise XY stage moves the pattern across the whole focal plane and comparing the variations of the spacing when it is imaged by different CCDs. Simulation and real measurements show that the two methods work very well for our purpose, and are in good agreement with the direct optical measurements.

  13. Improvement of the focal-plane detector system for medium heavy ions

    International Nuclear Information System (INIS)

    Wan Yude; Li Zhongzhen

    1992-01-01

    An improved medium heavy ion focal-plane detector system (500 mm long) was tested with beam and has been used in nuclear physics experiment. The measured results at tandem accelerator with 66 MeV 12 C beam are: the energy resolution of the residual energy E detector is about 7%. The experiment of particle discrimination has been performed

  14. Planck 2015 results: XII. Full focal plane simulations

    DEFF Research Database (Denmark)

    Ade, P. A R; Aghanim, N.; Arnaud, M.

    2016-01-01

    We present the 8th full focal plane simulation set (FFP8), deployed in support of the Planck 2015 results. FFP8 consists of 10 fiducial mission realizations reduced to 18 144 maps, together with the most massive suite of Monte Carlo realizations of instrument noise and CMB ever generated, compris...

  15. Chemical imaging of cotton fibers using an infrared microscope and a focal-plane array detector

    Science.gov (United States)

    In this presentation, the chemical imaging of cotton fibers with an infrared microscope and a Focal-Plane Array (FPA) detector will be discussed. Infrared spectroscopy can provide us with information on the structure and quality of cotton fibers. In addition, FPA detectors allow for simultaneous spe...

  16. Ballistic Target PHD Filter Based on Infrared Focal Plane Ambiguous Observation

    Directory of Open Access Journals (Sweden)

    Wei Zhao

    2017-01-01

    Full Text Available Space-based early warning system, the main detection means of which is passive detection based on focal plane, is an important part of ballistic missile defense system. The focal plane is mainly composed of CCD, and its size can reach the micron level, so the pixel is often regarded as point of no area in image postprocessing. The design of traditional tracking methods is based on this, and the observation based on the focal plane is modeled as the azimuth with random noise. However, this modeling is inaccurate. In the context of space-based detection, CCD cannot be simplified as a point, and its size should be considered. And the corresponding observation cannot be treated as azimuth with random noise. In this paper, the observation based on focal plane is modeled as Unambiguously Generated Ambiguous (UGA measurement. The PHD filter algorithm is redesigned and simplified. The simulation results show that the algorithm based on UGA measurement observation model has better tracking effect compared with that based on traditional observation model. This method provides technical support for more accurate target tracking for space-based early warning system.

  17. Radionuclide imaging with coded apertures and three-dimensional image reconstruction from focal-plane tomography

    International Nuclear Information System (INIS)

    Chang, L.T.

    1976-05-01

    Two techniques for radionuclide imaging and reconstruction have been studied;; both are used for improvement of depth resolution. The first technique is called coded aperture imaging, which is a technique of tomographic imaging. The second technique is a special 3-D image reconstruction method which is introduced as an improvement to the so called focal-plane tomography

  18. Radiation-Induced Transient Effects in Near Infrared Focal Plane Arrays

    Science.gov (United States)

    Reed, Robert A.; Pickel, J.; Marshall, P.; Waczynski, A.; McMurray, R.; Gee, G.; Polidan, E.; Johnson, S.; McKeivey, M.; Ennico, K.; hide

    2004-01-01

    This viewgraph presentation describes a test simulate the transient effects of cosmic ray impacts on near infrared focal plane arrays. The objectives of the test are to: 1) Characterize proton single events as function of energy and angle of incidence; 2) Measure charge spread (crosstalk) to adjacent pixels; 3) Assess transient recovery time.

  19. High Dynamic Range adaptive ΔΣ-based Focal Plane Array architecture

    KAUST Repository

    Yao, Shun; Kavusi, Sam; Salama, Khaled N.

    2012-01-01

    In this paper, an Adaptive Delta-Sigma based architecture for High Dynamic Range (HDR) Focal Plane Arrays is presented. The noise shaping effect of the Delta-Sigma modulation in the low end, and the distortion noise induced in the high end of Photo

  20. Deriving the effective focal plane for the CBM-RICH detector

    Energy Technology Data Exchange (ETDEWEB)

    Kres, Ievgenii [Wuppertal University (Germany); Collaboration: CBM-Collaboration

    2016-07-01

    The Compressed Baryonic Matter (CBM) experiment at the future FAIR complex will investigate the phase diagram of strongly interacting matter at high baryon density and moderate temperatures in A+A collisions from 2-11 AGeV (SIS100). A central component of the proposed detector setup is a ring imaging Cherenkov detector (RICH) using CO2 as radiator gas, and a focussing optic with a large spherical mirror. In the present design, the optimal focal plane is approximated using four individual, flat detection surfaces. However, the exact shape and position of the ideal focal plane is subject to further optimization due to effects from tilting the focussing mirror and from momentum dependant deflection of the electron tracks in the magnetic stray field. In this talk, we present a new approach to derive the effective 3-dimensional shape of the focal plane based on a set of Monte Carlo simulations, comparing the ring sharpness at each point of a preliminary focal plane as function of z-position.

  1. Landsat 9 OLI 2 focal plane subsystem: design, performance, and status

    Science.gov (United States)

    Malone, Kevin J.; Schrein, Ronald J.; Bradley, M. Scott; Irwin, Ronda; Berdanier, Barry; Donley, Eric

    2017-09-01

    The Landsat 9 mission will continue the legacy of Earth remote sensing that started in 1972. The Operational Land Imager 2 (OLI 2) is one of two instruments on the Landsat 9 satellite. The OLI 2 instrument is essentially a copy of the OLI instrument flying on Landsat 8. A key element of the OLI 2 instrument is the focal plane subsystem, or FPS, which consists of the focal plane array (FPA), the focal plane electronics (FPE) box, and low-thermal conductivity cables. This paper presents design details of the OLI 2 FPS. The FPA contains 14 critically-aligned focal plane modules (FPM). Each module contains 6 visible/near-IR (VNIR) detector arrays and three short-wave infrared (SWIR) arrays. A complex multi-spectral optical filter is contained in each module. Redundant pixels for each array provide exceptional operability. Spare detector modules from OLI were recharacterized after six years of storage. Radiometric test results are presented and compared with data recorded in 2010. Thermal, optical, mechanical and structural features of the FPA will be described. Special attention is paid to the thermal design of the FPA since thermal stability is crucial to ensuring low-noise and low-drift operation of the detectors which operate at -63°C. The OLI 2 FPE provides power, timing, and control to the focal plane modules. It also digitizes the video data and formats it for the solid-state recorder. Design improvements to the FPA-FPE cables will be discussed and characterization data will be presented. The paper will conclude with the status of the flight hardware assembly and testing.

  2. Innovative compact focal plane array for wide field vis and ir orbiting telescopes

    Science.gov (United States)

    Hugot, Emmanuel; Vives, Sébastien; Ferrari, Marc; Gaeremynck, Yann; Jahn, Wilfried

    2017-11-01

    The future generation of high angular resolution space telescopes will require breakthrough technologies to combine large diameters and large focal plane arrays with compactness and lightweight mirrors and structures. Considering the allocated volume medium-size launchers, short focal lengths are mandatory, implying complex optical relays to obtain diffraction limited images on large focal planes. In this paper we present preliminary studies to obtain compact focal plane arrays (FPA) for earth observations on low earth orbits at high angular resolution. Based on the principle of image slicers, we present an optical concept to arrange a 1D FPA into a 2D FPA, allowing the use of 2D detector matrices. This solution is particularly attractive for IR imaging requiring a cryostat, which volume could be considerably reduced as well as the relay optics complexity. Enabling the use of 2D matrices for such an application offers new possibilities. Recent developments on curved FPA allows optimization without concerns on the field curvature. This innovative approach also reduces the complexity of the telescope optical combination, specifically for fast telescopes. This paper will describe the concept and optical design of an F/5 - 1.5m telescope equipped with such a FPA, the performances and the impact on the system with a comparison with an equivalent 1.5m wide field Korsch telescope.

  3. Design and performance of single photon APD focal plane arrays for 3-D LADAR imaging

    Science.gov (United States)

    Itzler, Mark A.; Entwistle, Mark; Owens, Mark; Patel, Ketan; Jiang, Xudong; Slomkowski, Krystyna; Rangwala, Sabbir; Zalud, Peter F.; Senko, Tom; Tower, John; Ferraro, Joseph

    2010-08-01

    ×We describe the design, fabrication, and performance of focal plane arrays (FPAs) for use in 3-D LADAR imaging applications requiring single photon sensitivity. These 32 × 32 FPAs provide high-efficiency single photon sensitivity for three-dimensional LADAR imaging applications at 1064 nm. Our GmAPD arrays are designed using a planarpassivated avalanche photodiode device platform with buried p-n junctions that has demonstrated excellent performance uniformity, operational stability, and long-term reliability. The core of the FPA is a chip stack formed by hybridizing the GmAPD photodiode array to a custom CMOS read-out integrated circuit (ROIC) and attaching a precision-aligned GaP microlens array (MLA) to the back-illuminated detector array. Each ROIC pixel includes an active quenching circuit governing Geiger-mode operation of the corresponding avalanche photodiode pixel as well as a pseudo-random counter to capture per-pixel time-of-flight timestamps in each frame. The FPA has been designed to operate at frame rates as high as 186 kHz for 2 μs range gates. Effective single photon detection efficiencies as high as 40% (including all optical transmission and MLA losses) are achieved for dark count rates below 20 kHz. For these planar-geometry diffused-junction GmAPDs, isolation trenches are used to reduce crosstalk due to hot carrier luminescence effects during avalanche events, and we present details of the crosstalk performance for different operating conditions. Direct measurement of temporal probability distribution functions due to cumulative timing uncertainties of the GmAPDs and ROIC circuitry has demonstrated a FWHM timing jitter as low as 265 ps (standard deviation is ~100 ps).

  4. Focal-plane change triggered video compression for low-power vision sensor systems.

    Directory of Open Access Journals (Sweden)

    Yu M Chi

    Full Text Available Video sensors with embedded compression offer significant energy savings in transmission but incur energy losses in the complexity of the encoder. Energy efficient video compression architectures for CMOS image sensors with focal-plane change detection are presented and analyzed. The compression architectures use pixel-level computational circuits to minimize energy usage by selectively processing only pixels which generate significant temporal intensity changes. Using the temporal intensity change detection to gate the operation of a differential DCT based encoder achieves nearly identical image quality to traditional systems (4dB decrease in PSNR while reducing the amount of data that is processed by 67% and reducing overall power consumption reduction of 51%. These typical energy savings, resulting from the sparsity of motion activity in the visual scene, demonstrate the utility of focal-plane change triggered compression to surveillance vision systems.

  5. An efficient shutter-less non-uniformity correction method for infrared focal plane arrays

    Science.gov (United States)

    Huang, Xiyan; Sui, Xiubao; Zhao, Yao

    2017-02-01

    The non-uniformity response in infrared focal plane array (IRFPA) detectors has a bad effect on images with fixed pattern noise. At present, it is common to use shutter to prevent from radiation of target and to update the parameters of non-uniformity correction in the infrared imaging system. The use of shutter causes "freezing" image. And inevitably, there exists the problems of the instability and reliability of system, power consumption, and concealment of infrared detection. In this paper, we present an efficient shutter-less non-uniformity correction (NUC) method for infrared focal plane arrays. The infrared imaging system can use the data gaining in thermostat to calculate the incident infrared radiation by shell real-timely. And the primary output of detector except the shell radiation can be corrected by the gain coefficient. This method has been tested in real infrared imaging system, reaching high correction level, reducing fixed pattern noise, adapting wide temperature range.

  6. Paraxial design of an optical element with variable focal length and fixed position of principal planes.

    Science.gov (United States)

    Mikš, Antonín; Novák, Pavel

    2018-05-10

    In this article, we analyze the problem of the paraxial design of an active optical element with variable focal length, which maintains the positions of its principal planes fixed during the change of its optical power. Such optical elements are important in the process of design of complex optical systems (e.g., zoom systems), where the fixed position of principal planes during the change of optical power is essential for the design process. The proposed solution is based on the generalized membrane tunable-focus fluidic lens with several membrane surfaces.

  7. An ionization-chamber type of focal-plane detector for heavy ions

    International Nuclear Information System (INIS)

    Erskine, J.R.; Braid, T.H.; Stolfzfus, J.C.

    1976-01-01

    A focal-plane detector for heavy ions is described in which energy loss and total energy are measured with a gridded ionization chamber, and position along the focal plane and angle of incidence are measured with two resistive-wire proportional counters. The clean geometry of the detector makes it especially attractive for use with heavy ions of high specific ionization. Typical position resolutions of 1.0-1.5mm (fwhm) were observed over a 50 cm length of the detector in the focal plane of a split-pole magnetic spectrograph. Special tests were made which suggest that the limiting position resolution is 0.76 mm or better. The resolution of the energy-loss signal was typically 4.5% (fwhm). The resolution of the total energy signal was 1.0-1.5% (fwhm) for small entrance apertures of the spectrograph, although 0.7% resolution was observed under special circumstances. The angle of incidence was measured with an uncertainty of about 1.2% (fwhm). The availability of the many parameters needed for particle identification makes this detector especially useful for the study of weak reaction channels in heavy-ion-induced reactions. (Auth.)

  8. Self-Calibration Method Based on Surface Micromaching of Light Transceiver Focal Plane for Optical Camera

    Directory of Open Access Journals (Sweden)

    Jin Li

    2016-10-01

    Full Text Available In remote sensing photogrammetric applications, inner orientation parameter (IOP calibration of remote sensing camera is a prerequisite for determining image position. However, achieving such a calibration without temporal and spatial limitations remains a crucial but unresolved issue to date. The accuracy of IOP calibration methods of a remote sensing camera determines the performance of image positioning. In this paper, we propose a high-accuracy self-calibration method without temporal and spatial limitations for remote sensing cameras. Our method is based on an auto-collimating dichroic filter combined with a surface micromachining (SM point-source focal plane. The proposed method can autonomously complete IOP calibration without the need of outside reference targets. The SM procedure is used to manufacture a light transceiver focal plane, which integrates with point sources, a splitter, and a complementary metal oxide semiconductor sensor. A dichroic filter is used to fabricate an auto-collimation light reflection element. The dichroic filter, splitter, and SM point-source focal plane are integrated into a camera to perform an integrated self-calibration. Experimental measurements confirm the effectiveness and convenience of the proposed method. Moreover, the method can achieve micrometer-level precision and can satisfactorily complete real-time calibration without temporal or spatial limitations.

  9. High Frequency High Spectral Resolution Focal Plane Arrays for AtLAST

    Science.gov (United States)

    Baryshev, Andrey

    2018-01-01

    Large collecting area single dish telescope such as ATLAST will be especially effective for medium (R 1000) and high (R 50000) spectral resolution observations. Large focal plane array is a natural solution to increase mapping speed. For medium resolution direct detectors with filter banks (KIDs) and or heterodyne technology can be employed. We will analyze performance limits of comparable KID and SIS focal plane array taking into account quantum limit and high background condition of terrestrial observing site. For large heterodyne focal plane arrays, a high current density AlN junctions open possibility of large instantaneous bandwidth >40%. This and possible multi frequency band FPSs presents a practical challenge for spatial sampling and scanning strategies. We will discuss phase array feeds as a possible solution, including a modular back-end system, which can be shared between KID and SIS based FPA. Finally we will discuss achievable sensitivities and pixel co unts for a high frequency (>500 GHz) FPAs and address main technical challenges: LO distribution, wire counts, bias line multiplexing, and monolithic vs. discrete mixer component integration.

  10. MIXS on BepiColombo and its DEPFET based focal plane instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Treis, J., E-mail: jft@hll.mpg.d [MPI Semiconductor Laboratory, Otto-Hahn-Ring 6, 81739 Munich (Germany); MPI for Solar System Research, Max-Planck-Strasse 2, 37191 Katlenburg-Lindau (Germany); Andricek, L. [MPI Semiconductor Laboratory, Otto-Hahn-Ring 6, 81739 Munich (Germany); MPI for Physics, Foehringer Ring 6, 80805 Munich (Germany); Aschauer, F. [MPI Semiconductor Laboratory, Otto-Hahn-Ring 6, 81739 Munich (Germany); MPI for Extraterrestrial Physics, Giessenbachstrasse, 85748 Garching (Germany); Heinzinger, K. [MPI Semiconductor Laboratory, Otto-Hahn-Ring 6, 81739 Munich (Germany); PNSensor GmbH, Roemerstrasse 28, 80803 Munich (Germany); Herrmann, S. [MPI Semiconductor Laboratory, Otto-Hahn-Ring 6, 81739 Munich (Germany); MPI for Extraterrestrial Physics, Giessenbachstrasse, 85748 Garching (Germany); Hilchenbach, M. [MPI for Solar System Research, Max-Planck-Strasse 2, 37191 Katlenburg-Lindau (Germany); Lauf, T. [MPI Semiconductor Laboratory, Otto-Hahn-Ring 6, 81739 Munich (Germany); MPI for Extraterrestrial Physics, Giessenbachstrasse, 85748 Garching (Germany); Lechner, P.; Lutz, G.; Majewski, P. [MPI Semiconductor Laboratory, Otto-Hahn-Ring 6, 81739 Munich (Germany); PNSensor GmbH, Roemerstrasse 28, 80803 Munich (Germany); Porro, M. [MPI Semiconductor Laboratory, Otto-Hahn-Ring 6, 81739 Munich (Germany); MPI for Extraterrestrial Physics, Giessenbachstrasse, 85748 Garching (Germany); Richter, R.H. [MPI Semiconductor Laboratory, Otto-Hahn-Ring 6, 81739 Munich (Germany); MPI for Physics, Foehringer Ring 6, 80805 Munich (Germany); Schaller, G. [MPI Semiconductor Laboratory, Otto-Hahn-Ring 6, 81739 Munich (Germany); MPI for Extraterrestrial Physics, Giessenbachstrasse, 85748 Garching (Germany); Schnecke, M. [MPI Semiconductor Laboratory, Otto-Hahn-Ring 6, 81739 Munich (Germany); MPI for Physics, Foehringer Ring 6, 80805 Munich (Germany)

    2010-12-11

    Focal plane instrumentation based on DEPFET Macropixel devices, being a combination of the Detector-Amplifier structure DEPFET with a silicon drift chamber (SDD), has been proposed for the MIXS (Mercury Imaging X-ray Spectrometer) instrument on ESA's Mercury exploration mission BepiColombo. MIXS images X-ray fluorescent radiation from the Mercury surface with a lightweight X-ray mirror system on the focal plane detector to measure the spatially resolved element abundance in Mercury's crust. The sensor needs to have an energy resolution better than 200 eV FWHM at 1 keV and is required to cover an energy range from 0.5 to 10 keV, for a pixel size of 300x300{mu}m{sup 2}. Main challenges for the instrument are radiation damage and the difficult thermal environment in the mercury orbit. The production of the first batch of flight devices has been finished at the MPI semiconductor laboratory. Prototype modules have been assembled to verify the electrical properties of the devices; selected results are presented here. The prototype devices, Macropixel prototypes for the SIMBOL-X focal plane, are electrically fully compatible, but have a pixel size of 0.5x0.5 mm{sup 2}. Excellent homogeneity and near Fano-limited energy resolution at high readout speeds have been observed on these devices.

  11. MIXS on BepiColombo and its DEPFET based focal plane instrumentation

    International Nuclear Information System (INIS)

    Treis, J.; Andricek, L.; Aschauer, F.; Heinzinger, K.; Herrmann, S.; Hilchenbach, M.; Lauf, T.; Lechner, P.; Lutz, G.; Majewski, P.; Porro, M.; Richter, R.H.; Schaller, G.; Schnecke, M.

    2010-01-01

    Focal plane instrumentation based on DEPFET Macropixel devices, being a combination of the Detector-Amplifier structure DEPFET with a silicon drift chamber (SDD), has been proposed for the MIXS (Mercury Imaging X-ray Spectrometer) instrument on ESA's Mercury exploration mission BepiColombo. MIXS images X-ray fluorescent radiation from the Mercury surface with a lightweight X-ray mirror system on the focal plane detector to measure the spatially resolved element abundance in Mercury's crust. The sensor needs to have an energy resolution better than 200 eV FWHM at 1 keV and is required to cover an energy range from 0.5 to 10 keV, for a pixel size of 300x300μm 2 . Main challenges for the instrument are radiation damage and the difficult thermal environment in the mercury orbit. The production of the first batch of flight devices has been finished at the MPI semiconductor laboratory. Prototype modules have been assembled to verify the electrical properties of the devices; selected results are presented here. The prototype devices, Macropixel prototypes for the SIMBOL-X focal plane, are electrically fully compatible, but have a pixel size of 0.5x0.5 mm 2 . Excellent homogeneity and near Fano-limited energy resolution at high readout speeds have been observed on these devices.

  12. MIXS on BepiColombo and its DEPFET based focal plane instrumentation

    Science.gov (United States)

    Treis, J.; Andricek, L.; Aschauer, F.; Heinzinger, K.; Herrmann, S.; Hilchenbach, M.; Lauf, T.; Lechner, P.; Lutz, G.; Majewski, P.; Porro, M.; Richter, R. H.; Schaller, G.; Schnecke, M.; Schopper, F.; Soltau, H.; Stefanescu, A.; Strüder, L.; de Vita, G.

    2010-12-01

    Focal plane instrumentation based on DEPFET Macropixel devices, being a combination of the Detector-Amplifier structure DEPFET with a silicon drift chamber (SDD), has been proposed for the MIXS (Mercury Imaging X-ray Spectrometer) instrument on ESA's Mercury exploration mission BepiColombo. MIXS images X-ray fluorescent radiation from the Mercury surface with a lightweight X-ray mirror system on the focal plane detector to measure the spatially resolved element abundance in Mercury's crust. The sensor needs to have an energy resolution better than 200 eV FWHM at 1 keV and is required to cover an energy range from 0.5 to 10 keV, for a pixel size of 300×300μm2. Main challenges for the instrument are radiation damage and the difficult thermal environment in the mercury orbit. The production of the first batch of flight devices has been finished at the MPI semiconductor laboratory. Prototype modules have been assembled to verify the electrical properties of the devices; selected results are presented here. The prototype devices, Macropixel prototypes for the SIMBOL-X focal plane, are electrically fully compatible, but have a pixel size of 0.5×0.5 mm2. Excellent homogeneity and near Fano-limited energy resolution at high readout speeds have been observed on these devices.

  13. Focal plane instrumentation: a very high resolution MWPC system for inclined tracks

    International Nuclear Information System (INIS)

    Bertozzi, W.; Hynes, M.V.; Sargent, C.P.; Creswell, C.; Dunn, P.C.; Hirsch, A.; Leitch, M.; Norum, B.; Rad, F.N.; Sasanuma, T.

    1977-01-01

    A focal plane system has been developed for the MIT energy-loss spectrometer. The arrival time information from adjacent wires of one MWPC (s=2mm), is used to trace particle trajectories with a position resolution of 120μm (2sigma) and an angular resolution of less than 17 mrad (2sigma). The tracks are inclined to the MWPC at about 45 0 . The readout uses 3 delay lines connected to successive sense wires in a cyclical pattern. Coarse wire positions are determined by differences and drift times by sums of signal arrival times at the ends of the delays lines. A Cherenkov counter provides a fiducial signal. Interpolation is independent of drift velocity since the drift is normal to the sense plane. A similar readout with a second chamber provides position information perpendicular to momentum plane. This information is used to correct on-line for focal plane curvatures and other spectrometer aberrations. Final momentum resolution is about 10 -4 . (Auth.)

  14. Status of backthinned AlGaN based focal plane arrays for deep-UV imaging

    Science.gov (United States)

    Reverchon, J.-L.; Lehoucq, G.; Truffer, J.-P.; Costard, E.; Frayssinet, E.; Semond, F.; Duboz, J.-Y.; Giuliani, A.; Réfrégiers, M.; Idir, M.

    2017-11-01

    The achievement of deep ultraviolet (UV) focal plane arrays (FPA) is required for both solar physics [1] and micro electronics industry. The success of solar mission (SOHO, STEREO [2], SDO [3]…), has shown the accuracy of imaging at wavelengths from 10 nm to 140 nm to reveal effects occurring in the sun corona. Deep UV steppers at 13 nm are another demanding imaging technology for the microelectronic industry in terms of uniformity and stability. A third application concerns beam shaping of Synchrotron lines [4]. Consequently, such wavelengths are of prime importance whereas the vacuum UV wavelengths are very difficult to detect due to the dramatic interaction of light with materials. The fast development of nitrides has given the opportunity to investigate AlGaN as a material for UV detection. Camera based on AlGaN present an intrinsic spectral selectivity and an extremely low dark current at room temperature. We have previously presented several FPA dedicated to deep UV based on 320 x 256 pixels of Schottky photodiodes with a pitch of 30 μm [4, 5]. AlGaN is grown on a silicon substrate instead of sapphire substrate only transparent down to 200 nm. After a flip-chip hybridization, silicon substrate and AlGaN basal layer was removed by dry etching. Then, the spectral responsivity of the FPA presented a quantum efficiency (QE) from 5% to 20% from 50 nm to 290 nm when removing the highly doped contact layer via a selective wet etching. This FPA suffered from a low uniformity incompatible with imaging, and a long time response due to variations of conductivity in the honeycomb. We also observed a low rejection of visible. It is probably due to the same honeycomb conductivity enhancement for wavelength shorter than 360 nm, i.e., the band gap of GaN. We will show hereafter an improved uniformity due to the use of a precisely ICP (Inductively Coupled Plasma) controlled process. The final membrane thickness is limited to the desertion layer. Neither access resistance

  15. Low-Noise, UV-to-SWIR Broadband Photodiodes for Large-Format Focal Plane Array Sensors, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Broadband focal plane arrays, operating in UV-to-SWIR wavelength range, are required for atmospheric monitoring of greenhouse gases. Currently, separate image...

  16. Polarimeter on a Chip: Antenna-Coupled Microbolometers and Polarimeters for Submillimeterwave and Millimeterwave Focal Planes, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Future missions to study astrophysical sources at millimeter and submillimeter wavelengths require focal planes of 1000's of detectors that must operate at the...

  17. Photonic antenna enhanced middle wave and longwave infrared focal plane array with low noise and high operating temperature, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Photodetectors and focal plane arrays (FPAs) covering the middle-wave and longwave infrared (MWIR/LWIR) are of great importance in numerous NASA applications,...

  18. Dualband MW/LW Strained Layer Superlattice Focal Plane Arrays for Satellite-Based Wildfire Detection, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Infrared focal plane arrays (FPAs) based on Type-II strained layer superlattice (SLS) photodiodes have recently experienced significant advances. In Phase I we...

  19. Dualband MW/LW Strained Layer Superlattice Focal Plane Arrays For Satellite-Based Wildfire Detection, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Dualband focal plane arrays (FPAs) based on gallium-free Type-II strained layer superlattice (SLS) photodiodes have recently experienced significant advances. We...

  20. Development and construction of a focal-plane detector for the Munich Q3D spectrograph

    International Nuclear Information System (INIS)

    Lindner, H.

    1989-01-01

    For the Munich Q3D magnet spectrograph a focal-plane detector was developed, constructed, and taken in operation. It is primary layed out for light ions like p, d, t 3 He, and 4 He, but can be also applied for heavy ions. The position resolution amounts to about 0.1 mm at counting rates of about 10 kHz. In the detector filled with counting gas on anode wires along the focal plane charge avalanches are formed, which influence in several neighbouring cathode stripes of the dimension (3x25) mm 2 signals. These signals are singularily read out and digitized, i.e. to each of the at the whole 114 cathode strips is assigned an own preamplifier, puls shaper, peak detector, and analog-to-digital converter (ADC). After the digitization in a hardware-like constructed calculator unit the center of mass of the charge distribution influenced by the charge avalanche is calculated, the position of the incident particle is obtained. The detector yields beyond the position signal yet also a signal ΔE form the anode wires, which gives the energy loss of the particle in the gas space, as well as a residual-energy signal E rest from a scintillator, in which the particles are stopped. By this the radiation background (γ's and n) can be separated very well from the required particles. With the focal-plane detector the 103 Rh(d, p) 104 Rh transfer reaction was measured at three different spectrograph angles. The measured level energies and angular momentum transfers are compared with (n, γ) data and discussed. (orig.) [de

  1. Multiscale multichroic focal planes for measurements of the cosmic microwave background

    Science.gov (United States)

    Cukierman, Ari; Lee, Adrian T.; Raum, Christopher; Suzuki, Aritoki; Westbrook, Benjamin

    2018-01-01

    We report on the development of multiscale multichroic focal planes for measurements of the cosmic microwave background (CMB). A multichroic focal plane, i.e., one that consists of pixels that are simultaneously sensitive in multiple frequency bands, is an efficient architecture for increasing the sensitivity of an experiment as well as for disentangling the contamination due to galactic foregrounds, which is increasingly becoming the limiting factor in extracting cosmological information from CMB measurements. To achieve these goals, it is necessary to observe across a broad frequency range spanning roughly 30-350 GHz. For this purpose, the Berkeley CMB group has been developing multichroic pixels consisting of planar superconducting sinuous antennas coupled to extended hemispherical lenslets, which operate at sub-Kelvin temperatures. The sinuous antennas, microwave circuitry and the transition-edge-sensor (TES) bolometers to which they are coupled are integrated in a single lithographed wafer.We describe the design, fabrication, testing and performance of multichroic pixels with bandwidths of 3:1 and 4:1 across the entire frequency range of interest. Additionally, we report on a demonstration of multiscale pixels, i.e., pixels whose effective size changes as a function of frequency. This property keeps the beam width approximately constant across all frequencies, which in turn allows the sensitivity of the experiment to be optimal in every frequency band. We achieve this by creating phased arrays from neighboring lenslet-coupled sinuous antennas, where the size of each phased array is chosen independently for each frequency band. We describe the microwave circuitry in detail as well as the benefits of a multiscale architecture, e.g., mitigation of beam non-idealities, reduced readout requirements, etc. Finally, we discuss the design and fabrication of the detector modules and focal-plane structures including cryogenic readout components, which enable the

  2. InGaAs focal plane arrays for low-light-level SWIR imaging

    Science.gov (United States)

    MacDougal, Michael; Hood, Andrew; Geske, Jon; Wang, Jim; Patel, Falgun; Follman, David; Manzo, Juan; Getty, Jonathan

    2011-06-01

    Aerius Photonics will present their latest developments in large InGaAs focal plane arrays, which are used for low light level imaging in the short wavelength infrared (SWIR) regime. Aerius will present imaging in both 1280x1024 and 640x512 formats. Aerius will present characterization of the FPA including dark current measurements. Aerius will also show the results of development of SWIR FPAs for high temperaures, including imagery and dark current data. Finally, Aerius will show results of using the SWIR camera with Aerius' SWIR illuminators using VCSEL technology.

  3. Calibration of optical tweezers with positional detection in the back focal plane

    DEFF Research Database (Denmark)

    Tolic-Nørrelykke, S.F.; Schäffer, E.; Howard, J.

    2006-01-01

    We explain and demonstrate a new method of force and position calibrations for optical tweezers with back-focal-plane photodetection. The method combines power spectral measurements of thermal motion and the response to a sinusoidal motion of a translation stage. It consequently does not use...... and precise: true values are returned, with small error bars. We tested this experimentally, near and far from surfaces in the lateral directions. Both position and force calibrations were accurate to within 3%. To calibrate, we moved the sample with a piezoelectric translation stage, but the laser beam could...

  4. Upgrade of the TAMU MDM-focal plane detector with MicroMegas technology

    Energy Technology Data Exchange (ETDEWEB)

    Spiridon, A., E-mail: aspiridon@comp.tamu.edu [Cyclotron Institute, Texas A& M University, College Station, TX 77843 (United States); Pollacco, E. [IRFU, CEA Saclay, Gif-sur-Yvette (France); Roeder, B.T.; Saastamoinen, A.; Chyzh, R.; Dag, M.; Tribble, R.E. [Cyclotron Institute, Texas A& M University, College Station, TX 77843 (United States); Trache, L.; Pascovici, G. [National Institute of Physics and Nuclear Engineering, Bucharest-Magurele RO-077125 (Romania); De Oliveira, R. [CERN, Geneva (Switzerland)

    2016-06-01

    A gridded ionization chamber used as a focal plane detector at the back of the TAMU-MDM spectrometer was modified to use MicroMegas technology for the purpose of improving energy resolution and particle identification. The upgraded system was tested in experimental conditions with several heavy-ion beams at 12 MeV/u and found to achieve resolutions between 3.2% and 4.8%. This is a significant improvement over the previous performance of 10–15% obtained using the existing, conventional ionization chambers.

  5. Upgrade of the TAMU MDM-focal plane detector with MicroMegas technology

    International Nuclear Information System (INIS)

    Spiridon, A.; Pollacco, E.; Roeder, B.T.; Saastamoinen, A.; Chyzh, R.; Dag, M.; Tribble, R.E.; Trache, L.; Pascovici, G.; De Oliveira, R.

    2016-01-01

    A gridded ionization chamber used as a focal plane detector at the back of the TAMU-MDM spectrometer was modified to use MicroMegas technology for the purpose of improving energy resolution and particle identification. The upgraded system was tested in experimental conditions with several heavy-ion beams at 12 MeV/u and found to achieve resolutions between 3.2% and 4.8%. This is a significant improvement over the previous performance of 10–15% obtained using the existing, conventional ionization chambers.

  6. Detector system of the first focal plane of the spectrometer SMART at RIKEN

    International Nuclear Information System (INIS)

    Okamura, H.; Izshida, S.; Sakamoto, N.; Otsu, H.; Uesaka, T.; Wakasa, T.; Satou, Y.; Sakai, H.; Ichihara, T.

    1998-01-01

    A detector system of the first focal plane of SMART, the 135 MeV/u high-resolution spectrometer at RIKEN accelerator research facility, is described. It consists of a pair of multi-wire drift chambers and a trigger scintillator hodoscope contained in a He-filled detector box. A major subject using this system is the measurement of the (d, 2 He) reaction making the most of its large angular and momentum acceptances. Without seriously sacrificing the detection efficiency, reasonably good energy and angular resolutions for 2 He, 460 keV and 9 mrad (FWHM), respectively, have been achieved after optimizing the optics property of the spectrometer. (orig.)

  7. Measurement, characterization, and modeling of noise in staring infrared focal plane arrays

    International Nuclear Information System (INIS)

    Scribner, D.A.; Kruer, M.R.; Gridley, C.J.; Sarkady, K.

    1987-01-01

    An account is given of selected methods for the measurement and characterization of spatial and temporal noise in staring focal plane arrays (FPAs), in order to demonstrate how these results can be used in simulations and analytic models to predict the performance of selected staring sensors. Attention is given to MIR FPAs applicable to the detection and tracking of point sources, and to the ways in which these spatial and temporal noise measurements can be incorporated into simulations and sensors having staring FPAs. Methods for predicting the performance of selected staring sensor systems are derivable from spatial and temporal noise values. 13 references

  8. NbN A/D Conversion of IR Focal Plane Sensor Signal at 10 K

    Science.gov (United States)

    Eaton, L.; Durand, D.; Sandell, R.; Spargo, J.; Krabach, T.

    1994-01-01

    We are implementing a 12 bit SFQ counting ADC with parallel-to-serial readout using our established 10 K NbN capability. This circuit provides a key element of the analog signal processor (ASP) used in large infrared focal plane arrays. The circuit processes the signal data stream from a Si:As BIB detector array. A 10 mega samples per second (MSPS) pixel data stream flows from the chip at a 120 megabit bit rate in a format that is compatible with other superconductive time dependent processor (TDP) circuits being developed. We will discuss our planned ASP demonstration, the circuit design, and test results.

  9. Low-Noise CMOS Circuits for On-Chip Signal Processing in Focal-Plane Arrays

    Science.gov (United States)

    Pain, Bedabrata

    The performance of focal-plane arrays can be significantly enhanced through the use of on-chip signal processing. Novel, in-pixel, on-focal-plane, analog signal-processing circuits for high-performance imaging are presented in this thesis. The presence of a high background-radiation is a major impediment for infrared focal-plane array design. An in-pixel, background-suppression scheme, using dynamic analog current memory circuit, is described. The scheme also suppresses spatial noise that results from response non-uniformities of photo-detectors, leading to background limited infrared detector readout performance. Two new, low-power, compact, current memory circuits, optimized for operation at ultra-low current levels required in infrared-detection, are presented. The first one is a self-cascading current memory that increases the output impedance, and the second one is a novel, switch feed-through reducing current memory, implemented using error-current feedback. This circuit can operate with a residual absolute -error of less than 0.1%. The storage-time of the memory is long enough to also find applications in neural network circuits. In addition, a voltage-mode, accurate, low-offset, low-power, high-uniformity, random-access sample-and-hold cell, implemented using a CCD with feedback, is also presented for use in background-suppression and neural network applications. A new, low noise, ultra-low level signal readout technique, implemented by individually counting photo-electrons within the detection pixel, is presented. The output of each unit-cell is a digital word corresponding to the intensity of the photon flux, and the readout is noise free. This technique requires the use of unit-cell amplifiers that feature ultra-high-gain, low-power, self-biasing capability and noise in sub-electron levels. Both single-input and differential-input implementations of such amplifiers are investigated. A noise analysis technique is presented for analyzing sampled

  10. Status and Integrated Focal Plane Characterization of Simons Array - Cosmic Microwave Background Polarimetry Experiment

    Science.gov (United States)

    Roberts, Hayley; POLARBEAR

    2018-06-01

    Simons Array is a cosmic microwave background (CMB) polarization experiment located at 5,200 meter altitude site in the Atacama desert in Chile. The science goals of the Simons Array are to characterize the CMB B-mode signal from gravitational lensing, and search for B-mode polarization generated from inflationary gravitational waves.In 2012, POLARBEAR-1 (PB-1) began observations and the POLARBEAR team has published the first measurements of non-zero polarization B-mode polarization angular power spectrum where gravitational lensing of CMB is the dominant signal.POLARBEAR-2A (PB-2A), the first of three receivers of Simons Array, will have 7,588 polarization sensitive Transition Edge Sensor (TES) bolometers with frequencies 90 GHz and 150 GHz. This represents a factor of 6 increase in detector count compared to PB-1. Once Simons Array is fully deployed, the focal plane array will consist 22,764 TES bolometers across 90 GHz, 150 GHz, 220 GHz, and 270 GHz with a projected instantaneous sensitivity of 2.5 µK√s. Here we present the status of PB-2A and characterization of the integrated focal plane to be deployed summer of 2018.

  11. A focal plane detector design for a wide-band Laue-lens telescope

    DEFF Research Database (Denmark)

    Caroli, E.; Auricchio, N.; Amati, L.

    2005-01-01

    , and the detection of nuclear and annihilation lines. Recently the development of high energy Laue lenses with broad energy bandpasses from 60 to 600 keV have been proposed for a Hard X ray focusing Telescope (HAXTEL) in order to study the X-ray continuum of celestial sources. The required focal plane detector...... should have high detection efficiency over the entire operative range, a spatial resolution of about 1 mm, an energy resolution of a few keV at 500 keV and a sensitivity to linear polarization. We describe a possible configuration of the focal plane detector based on several CdTe/CZT pixelated layers......The energy range above 60 keV is important for the study of many open problems in high energy astrophysics such as the role of Inverse Compton with respect to synchrotron or thermal processes in GRBs, non thermal mechanisms in SNR, the study of the high energy cut-offs in AGN spectra...

  12. Removing defocused objects from single focal plane scans of cytological slides

    Directory of Open Access Journals (Sweden)

    David Friedrich

    2016-01-01

    Full Text Available Background: Virtual microscopy and automated processing of cytological slides are more challenging compared to histological slides. Since cytological slides exhibit a three-dimensional surface and the required microscope objectives with high resolution have a low depth of field, these cannot capture all objects of a single field of view in focus. One solution would be to scan multiple focal planes; however, the increase in processing time and storage requirements are often prohibitive for clinical routine. Materials and Methods: In this paper, we show that it is a reasonable trade-off to scan a single focal plane and automatically reject defocused objects from the analysis. To this end, we have developed machine learning solutions for the automated identification of defocused objects. Our approach includes creating novel features, systematically optimizing their parameters, selecting adequate classifier algorithms, and identifying the correct decision boundary between focused and defocused objects. We validated our approach for computer-assisted DNA image cytometry. Results and Conclusions: We reach an overall sensitivity of 96.08% and a specificity of 99.63% for identifying defocused objects. Applied on ninety cytological slides, the developed classifiers automatically removed 2.50% of the objects acquired during scanning, which otherwise would have interfered the examination. Even if not all objects are acquired in focus, computer-assisted DNA image cytometry still identified more diagnostically or prognostically relevant objects compared to manual DNA image cytometry. At the same time, the workload for the expert is reduced dramatically.

  13. Focal plane instrument for the Solar UV-Vis-IR Telescope aboard SOLAR-C

    Science.gov (United States)

    Katsukawa, Yukio; Suematsu, Yoshinori; Shimizu, Toshifumi; Ichimoto, Kiyoshi; Takeyama, Norihide

    2011-10-01

    It is presented the conceptual design of a focal plane instrument for the Solar UV-Vis-IR Telescope (SUVIT) aboard the next Japanese solar mission SOLAR-C. A primary purpose of the telescope is to achieve precise as well as high resolution spectroscopic and polarimetric measurements of the solar chromosphere with a big aperture of 1.5 m, which is expected to make a significant progress in understanding basic MHD processes in the solar atmosphere. The focal plane instrument consists of two packages: A filtergraph package is to get not only monochromatic images but also Dopplergrams and magnetograms using a tunable narrow-band filter and interference filters. A spectrograph package is to perform accurate spectro-polarimetric observations for measuring chromospheric magnetic fields, and is employing a Littrow-type spectrograph. The most challenging aspect in the instrument design is wide wavelength coverage from 280 nm to 1.1 μm to observe multiple chromospheric lines, which is to be realized with a lens unit including fluoride glasses. A high-speed camera for correlation tracking of granular motion is also implemented in one of the packages for an image stabilization system, which is essential to achieve high spatial resolution and high polarimetric accuracy.

  14. Closed-loop focal plane wavefront control with the SCExAO instrument

    Science.gov (United States)

    Martinache, Frantz; Jovanovic, Nemanja; Guyon, Olivier

    2016-09-01

    Aims: This article describes the implementation of a focal plane based wavefront control loop on the high-contrast imaging instrument SCExAO (Subaru Coronagraphic Extreme Adaptive Optics). The sensor relies on the Fourier analysis of conventional focal-plane images acquired after an asymmetric mask is introduced in the pupil of the instrument. Methods: This absolute sensor is used here in a closed-loop to compensate for the non-common path errors that normally affects any imaging system relying on an upstream adaptive optics system.This specific implementation was used to control low-order modes corresponding to eight zernike modes (from focus to spherical). Results: This loop was successfully run on-sky at the Subaru Telescope and is used to offset the SCExAO deformable mirror shape used as a zero-point by the high-order wavefront sensor. The paper details the range of errors this wavefront-sensing approach can operate within and explores the impact of saturation of the data and how it can be bypassed, at a cost in performance. Conclusions: Beyond this application, because of its low hardware impact, the asymmetric pupil Fourier wavefront sensor (APF-WFS) can easily be ported in a wide variety of wavefront sensing contexts, for ground- as well space-borne telescopes, and for telescope pupils that can be continuous, segmented or even sparse. The technique is powerful because it measures the wavefront where it really matters, at the level of the science detector.

  15. Image interpolation and denoising for division of focal plane sensors using Gaussian processes.

    Science.gov (United States)

    Gilboa, Elad; Cunningham, John P; Nehorai, Arye; Gruev, Viktor

    2014-06-16

    Image interpolation and denoising are important techniques in image processing. These methods are inherent to digital image acquisition as most digital cameras are composed of a 2D grid of heterogeneous imaging sensors. Current polarization imaging employ four different pixelated polarization filters, commonly referred to as division of focal plane polarization sensors. The sensors capture only partial information of the true scene, leading to a loss of spatial resolution as well as inaccuracy of the captured polarization information. Interpolation is a standard technique to recover the missing information and increase the accuracy of the captured polarization information. Here we focus specifically on Gaussian process regression as a way to perform a statistical image interpolation, where estimates of sensor noise are used to improve the accuracy of the estimated pixel information. We further exploit the inherent grid structure of this data to create a fast exact algorithm that operates in ����(N(3/2)) (vs. the naive ���� (N³)), thus making the Gaussian process method computationally tractable for image data. This modeling advance and the enabling computational advance combine to produce significant improvements over previously published interpolation methods for polarimeters, which is most pronounced in cases of low signal-to-noise ratio (SNR). We provide the comprehensive mathematical model as well as experimental results of the GP interpolation performance for division of focal plane polarimeter.

  16. Multispectral Thermal Imager Optical Assembly Performance and Integration of the Flight Focal Plane Assembly

    International Nuclear Information System (INIS)

    Blake, Dick; Byrd, Don; Christensen, Wynn; Henson, Tammy; Krumel, Les; Rappoport, William; Shen, Gon-Yen

    1999-01-01

    The Multispectral Thermal Imager Optical Assembly (OA) has been fabricated, assembled, successfully performance tested, and integrated into the flight payload structure with the flight Focal Plane Assembly (FPA) integrated and aligned to it. This represents a major milestone achieved towards completion of this earth observing E-O imaging sensor that is to be operated in low earth orbit. The OA consists of an off-axis three mirror anastigmatic (TMA) telescope with a 36 cm unobscured clear aperture, a wide-field-of-view (WFOV) of 1.82 along the direction of spacecraft motion and 1.38 across the direction of spacecraft motion. It also contains a comprehensive on-board radiometric calibration system. The OA is part of a multispectral pushbroom imaging sensor which employs a single mechanically cooled focal plane with 15 spectral bands covering a wavelength range from 0.45 to 10.7 m. The OA achieves near diffraction-limited performance from visible to the long-wave infrared (LWIR) wavelengths. The two major design drivers for the OA are 80% enpixeled energy in the visible bands and radiometric stability. Enpixeled energy in the visible bands also drove the alignment of the FPA detectors to the OA image plane to a requirement of less than 20 m over the entire visible detector field of view (FOV). Radiometric stability requirements mandated a cold Lyot stop for stray light rejection and thermal background reduction. The Lyot stop is part of the FPA assembly and acts as the aperture stop for the imaging system. The alignment of the Lyot stop to the OA drove the centering and to some extent the tilt alignment requirements of the FPA to the OA

  17. Numerical simulation of the modulation transfer function (MTF) in infrared focal plane arrays: simulation methodology and MTF optimization

    Science.gov (United States)

    Schuster, J.

    2018-02-01

    Military requirements demand both single and dual-color infrared (IR) imaging systems with both high resolution and sharp contrast. To quantify the performance of these imaging systems, a key measure of performance, the modulation transfer function (MTF), describes how well an optical system reproduces an objects contrast in the image plane at different spatial frequencies. At the center of an IR imaging system is the focal plane array (FPA). IR FPAs are hybrid structures consisting of a semiconductor detector pixel array, typically fabricated from HgCdTe, InGaAs or III-V superlattice materials, hybridized with heat/pressure to a silicon read-out integrated circuit (ROIC) with indium bumps on each pixel providing the mechanical and electrical connection. Due to the growing sophistication of the pixel arrays in these FPAs, sophisticated modeling techniques are required to predict, understand, and benchmark the pixel array MTF that contributes to the total imaging system MTF. To model the pixel array MTF, computationally exhaustive 2D and 3D numerical simulation approaches are required to correctly account for complex architectures and effects such as lateral diffusion from the pixel corners. It is paramount to accurately model the lateral di_usion (pixel crosstalk) as it can become the dominant mechanism limiting the detector MTF if not properly mitigated. Once the detector MTF has been simulated, it is directly decomposed into its constituent contributions to reveal exactly what is limiting the total detector MTF, providing a path for optimization. An overview of the MTF will be given and the simulation approach will be discussed in detail, along with how different simulation parameters effect the MTF calculation. Finally, MTF optimization strategies (crosstalk mitigation) will be discussed.

  18. Antennas for Terahertz Applications: Focal Plane Arrays and On-chip Non-contact Measurement Probes

    Science.gov (United States)

    Trichopoulos, Georgios C.

    The terahertz (THz) band provides unique sensing opportunities that enable several important applications such as biomedical imaging, remote non-destructive inspection of packaged goods, and security screening. THz waves can penetrate most materials and can provide unique spectral information in the 0.1--10 THz band with high resolution. In contrast, other imaging modalities, like infrared (IR), suffer from low penetration depths and are thus not attractive for non-destructive evaluation. However, state-of-the-art THz imaging systems typically employ mechanical raster scans using a single detector to acquire two-dimensional images. Such devices tend to be bulky and complicated due to the mechanical parts, and are thus rather expensive to develop and operate. Thus, large-format (e.g. 100x100 pixels) and all-electronics based THz imaging systems are badly needed to alleviate the space, weight and power (SWAP) factors and enable cost effective utilization of THz waves for sensing and high-data-rate communications. In contrast, photonic sensors are very compact because light can couple directly to the photodiode without residing to radiation coupling topologies. However, in the THz band, due to the longer wavelengths and much lower photon energies, highly efficient antennas with optimized input impedance have to be integrated with THz sensors. Here, we implement novel antenna engineering techniques that are optimized to take advantage of recent technological advances in solid-state THz sensing devices. For example, large-format focal plane arrays (FPAs) have been the Achilles' heel of THz imaging systems. Typically, optical components (lenses, mirrors) are employed in order to improve the optical performance of FPAs, however, antenna sensors suffer from degraded performance when they are far from the optical axis, thus minimizing the number of useful FPA elements. By modifying the radiation pattern of FPA antennas we manage to alleviate the off-axis aberration

  19. Focal plane subsystem design and performance for atmospheric chemistry from geostationary orbit tropospheric emissions monitoring of pollution

    Science.gov (United States)

    Gilmore, A. S.; Philbrick, R. H.; Funderburg, J.

    2017-09-01

    Remote sensing of pollutants are enabled from a satellite in a geostationary orbit containing an imaging spectrometer encompassing the wavelength ranges of 290 - 490 nm and 540 - 740 nm. As the first of NASA's Earth Venture Instrument Program, the Tropospheric Emissions: Monitoring of Pollution (TEMPO) program will utilize this instrument to measure hourly air quality over a large portion of North America. The focal plane subsystem (FPS) contains two custom designed and critically aligned full frame transfer charge coupled devices (active area: 1028 x 2048, 18 μm) within a focal plane array package designed for radiation tolerance and space charging rejection. In addition, the FPS contains custom distributed focal plane electronics that provide all necessary clocks and biases to the sensors, receives all analog data from the sensors and performs 14 bit analog to digital conversion for upstream processing. Finally, the FPS encompasses custom low noise cables connecting the focal plane array and associated electronics. This paper discusses the design and performance of this novel focal plane subsystem with particular emphasis on the optical performance achieved including alignment, quantum efficiency, and modulation transfer function.

  20. An All Silicon Feedhorn-Coupled Focal Plane for Cosmic Microwave Background Polarimetry

    Science.gov (United States)

    Hubmayr, J.; Appel, J. W.; Austermann, J. E.; Beall, J. A.; Becker, D.; Benson, B. A.; Bleem, L. E.; Carlstrom, J. E.; Chang, C. L.; Cho, H. M.; hide

    2011-01-01

    Upcoming experiments aim to produce high fidelity polarization maps of the cosmic microwave background. To achieve the required sensitivity, we are developing monolithic, feedhorn-coupled transition edge sensor polarimeter arrays operating at 150 GHz. We describe this focal plane architecture and the current status of this technology, focusing on single-pixel polarimeters being deployed on the Atacama B-mode Search (ABS) and an 84-pixel demonstration feedhorn array backed by four 10-pixel polarimeter arrays. The feedhorn array exhibits symmetric beams, cross-polar response less than -23 dB and excellent uniformity across the array. Monolithic polarimeter arrays, including arrays of silicon feedhorns, will be used in the Atacama Cosmology Telescope Polarimeter (ACTPol) and the South Pole Telescope Polarimeter (SPTpol) and have been proposed for upcoming balloon-borne instruments.

  1. The Advanced Gamma-ray Imaging System (AGIS): Focal Plane Detectors

    Science.gov (United States)

    Mukherjee, Reshmi; Byrum, K.; Drake, G.; Falcone, A.; Funk, S.; Horan, D.; Tajima, H.; Wagner, B.; Williams, D.

    2008-04-01

    Report of the Focal Plane Instrumentation Working Group, AGIS collaboration: The Advanced Gamma-ray Imaging System (AGIS) is a concept for the next generation instrument in ground-based very high energy gamma-ray astronomy. It has the goal of achieving significant improvement in sensitivity over current experiments. One of the main requirements for AGIS will be to achieve higher angular resolution than current imaging atmospheric Cherenkov telescopes (IACTs). Simulations show that a substantial improvement in angular resolution may be achieved if the pixel size is reduced to 0.05 deg, below that of current IACTs. Reducing the cost per channel and improving reliability and modularity are other important considerations. Here we present several alternatives being considered for AGIS, including both silicon photomultipliers (SiPMs) and multi-anode photomultipliers (MAPMTs) and summarize results from feasibility testing by various AGIS photodetector group members.

  2. A math model for high velocity sensoring with a focal plane shuttered camera.

    Science.gov (United States)

    Morgan, P.

    1971-01-01

    A new mathematical model is presented which describes the image produced by a focal plane shutter-equipped camera. The model is based upon the well-known collinearity condition equations and incorporates both the translational and rotational motion of the camera during the exposure interval. The first differentials of the model with respect to exposure interval, delta t, yield the general matrix expressions for image velocities which may be simplified to known cases. The exposure interval, delta t, may be replaced under certain circumstances with a function incorporating blind velocity and image position if desired. The model is tested using simulated Lunar Orbiter data and found to be computationally stable as well as providing excellent results, provided that some external information is available on the velocity parameters.

  3. Argus: A W-band 16-pixel focal plane array for the Green Bank Telescope

    Science.gov (United States)

    Devaraj, Kiruthika; Church, Sarah; Cleary, Kieran; Frayer, David; Gawande, Rohit; Goldsmith, Paul; Gundersen, Joshua; Harris, Andrew; Kangaslahti, Pekka; Readhead, Tony; Reeves, Rodrigo; Samoska, Lorene; Sieth, Matt; Voll, Patricia

    2015-05-01

    We are building Argus, a 16-pixel square-packed focal plane array that will cover the 75-115.3 GHz frequency range on the Robert C. Byrd Green Bank Telescope (GBT). The primary research area for Argus is the study of star formation within our Galaxy and nearby galaxies. Argus will map key molecules that trace star formation, including carbon monoxide (CO) and hydrogen cyanide (HCN). An additional key science area is astrochemistry, which will be addressed by observing complex molecules in the interstellar medium, and the study of formation of solar systems, which will be addressed by identifying dense pre-stellar cores and by observing comets in our solar system. Argus has a highly scalable architecture and will be a technology path finder for larger arrays. The array is modular in construction, which will allow easy replacement of malfunctioning and poorly performing components.

  4. Research of Infrared Imaging at Atmospheric Pressure Using a Substrate-Free Focal Plane Array

    International Nuclear Information System (INIS)

    Wu Jian-Xiong; Cheng Teng; Zhang Qing-Chuan; Zhang Yong; Mao Liang; Gao Jie; Wu Xiao-Ping; Chen Da-Peng

    2013-01-01

    An equivalent circuit model to the substrate-free focal plane array (FPA) is established. Using this fast and effective model, the performance of infrared (IR) imaging at atmospheric pressure is investigated and it is found that the substrate-free FPA has the ability of IR imaging at atmospheric pressure, whereas it has a slightly degraded noise equivalent temperature difference (NETD) as compared with IR imaging under a high vacuum. This feature is also identified experimentally by a substrate-free FPA with pixel size of 50 × 50 μm 2 . The NETDs are measured to be 160 mK at 10 −2 Pa pressure and 1.08 K at atmospheric pressure

  5. Data acquisition system for the focal-plane detector of the mass separator MASHA

    International Nuclear Information System (INIS)

    Novoselov, A.S.; Rodin, A.M.; Podshibyakin, A.V.; Belozerov, A.V.; Vedeneyev, V.Yu.; Gulyaev, A.V.; Gulyaeva, A.V.; Salamatin, V.S.; Stepantsov, S.V.; Chernysheva, E.V.; Yukhimchuk, S.A.; Komarov, A.B.; Motycak, S.; Krupa, L.; Kliman, J.; Kamas, D.

    2016-01-01

    The results of the development and the general information about the data acquisition system which was recently created at the MASHA setup (Flerov Laboratory of Nuclear Reactions at the Joint Institute for Nuclear Research) are presented. The main difference from the previous system is that we use a new modern platform, National Instruments PXI with XIA multichannel high-speed digitizers (250 MHz 12 bit 16 channels). At this moment the system has 448 spectrometric channels. The software and its features for the data acquisition and analysis are also described. The new DAQ system expands precision measuring capabilities of alpha decays and spontaneous fission at the focal-plane position-sensitive silicon strip detector which, in turn, increases the capabilities of the setup in such a field as low-yield registration of elements.

  6. A new focal plane detector for the gas-filled separator TASCA

    International Nuclear Information System (INIS)

    Gorshkov, Alexander

    2010-01-01

    Superheavy elements (SHE) exist solely because of enhanced nuclear stability due to shell effects. The production cross sections for the synthesis of SHE decrease continuously, thus, exploration of SHE nuclei is close to the border of present technical limitation. To increase the efficiency and sensitivity in SHE experiments, highly efficient recoil separators with state-of-the-art detection systems are required. In the framework of this thesis, the new focal plane detection system with the dedicated electronics have been developed for the gas-filled recoil separator TASCA at the GSI Helmholtzzentrum for Schwerionenforschung GmbH. The new detection system has been successfully used in recent experiments on synthesis of the E114.

  7. Mercury-Cadmium-Telluride Focal Plane Array Performance Under Non-Standard Operating Conditions

    Science.gov (United States)

    Richardson, Brandon S.; Eastwood, Michael L.; Bruce, Carl F.; Green, Robert O.; Coles, J. B.

    2011-01-01

    This paper highlights a new technique that allows the Teledyne Scientific & Imaging LLC TCM6604A Mercury-Cadmium-Telluride (MCT) Focal Plane Array (FPA) to operate at room temperature. The Teledyne MCT FPA has been a standard in Imaging Spectroscopy since its creation in the 1980's. This FPA has been used in applications ranging from space instruments such as CRISM, M3 and ARTEMIS to airborne instruments such as MaRS and the Next Generation AVIRIS Instruments1. Precise focal plane alignment is always a challenge for such instruments. The current FPA alignment process results in multiple cold cycles requiring week-long durations, thereby increasing the risk and cost of a project. These alignment cycles are necessary because optimal alignment is approached incrementally and can only be measured with the FPA and Optics at standard operating conditions, requiring a cold instrument. Instruments using this FPA are normally cooled to temperatures below 150K for the MCT FPA to properly function. When the FPA is run at higher temperatures the dark current increases saturating the output. This paper covers the prospect of warm MCT FPA operation from a theoretical and experimental perspective. We discuss the empirical models and physical laws that govern MCT material properties and predict the optimal settings that will result in the best MCT PA performance at 300K. Theoretical results are then calculated for the proposed settings. We finally present the images and data obtained using the actual system with the warm MCT FPA settings. The paper concludes by emphasizing the strong positive correlation between the measured values and the theoretical results.

  8. BER Analysis of Coherent Free-Space Optical Communication Systems with a Focal-Plane-Based Wavefront Sensor

    Science.gov (United States)

    Cao, Jingtai; Zhao, Xiaohui; Liu, Wei; Gu, Haijun

    2018-03-01

    A wavefront sensor is one of most important units for an adaptive optics system. Based on our previous works, in this paper, we discuss the bit-error-rate (BER) performance of coherent free space optical communication systems with a focal-plane-based wavefront sensor. Firstly, the theory of a focal-plane-based wavefront sensor is given. Then the relationship between the BER and the mixing efficiency with a homodyne receiver is discussed on the basis of binary-phase-shift-keying (BPSK) modulation. Finally, the numerical simulation results are shown that the BER will be decreased obviously after aberrations correction with the focal-plane-based wavefront sensor. In addition, the BER will decrease along with increasing number of photons received within a single bit. These analysis results will provide a reference for the design of the coherent Free space optical communication (FSOC) system.

  9. Statistical framework for the utilization of simultaneous pupil plane and focal plane telemetry for exoplanet imaging. I. Accounting for aberrations in multiple planes.

    Science.gov (United States)

    Frazin, Richard A

    2016-04-01

    A new generation of telescopes with mirror diameters of 20 m or more, called extremely large telescopes (ELTs), has the potential to provide unprecedented imaging and spectroscopy of exoplanetary systems, if the difficulties in achieving the extremely high dynamic range required to differentiate the planetary signal from the star can be overcome to a sufficient degree. Fully utilizing the potential of ELTs for exoplanet imaging will likely require simultaneous and self-consistent determination of both the planetary image and the unknown aberrations in multiple planes of the optical system, using statistical inference based on the wavefront sensor and science camera data streams. This approach promises to overcome the most important systematic errors inherent in the various schemes based on differential imaging, such as angular differential imaging and spectral differential imaging. This paper is the first in a series on this subject, in which a formalism is established for the exoplanet imaging problem, setting the stage for the statistical inference methods to follow in the future. Every effort has been made to be rigorous and complete, so that validity of approximations to be made later can be assessed. Here, the polarimetric image is expressed in terms of aberrations in the various planes of a polarizing telescope with an adaptive optics system. Further, it is shown that current methods that utilize focal plane sensing to correct the speckle field, e.g., electric field conjugation, rely on the tacit assumption that aberrations on multiple optical surfaces can be represented as aberration on a single optical surface, ultimately limiting their potential effectiveness for ground-based astronomy.

  10. Tests of the Monte Carlo simulation of the photon-tagger focal-plane electronics at the MAX IV Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Preston, M.F. [Lund University, SE-221 00 Lund (Sweden); Myers, L.S. [Duke University, Durham, NC 27708 (United States); Annand, J.R.M. [University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom); Fissum, K.G., E-mail: kevin.fissum@nuclear.lu.se [Lund University, SE-221 00 Lund (Sweden); Hansen, K.; Isaksson, L. [MAX IV Laboratory, Lund University, SE-221 00 Lund (Sweden); Jebali, R. [Arktis Radiation Detectors Limited, 8045 Zürich (Switzerland); Lundin, M. [MAX IV Laboratory, Lund University, SE-221 00 Lund (Sweden)

    2014-04-21

    Rate-dependent effects in the electronics used to instrument the tagger focal plane at the MAX IV Laboratory were recently investigated using the novel approach of Monte Carlo simulation to allow for normalization of high-rate experimental data acquired with single-hit time-to-digital converters (TDCs). The instrumentation of the tagger focal plane has now been expanded to include multi-hit TDCs. The agreement between results obtained from data taken using single-hit and multi-hit TDCs demonstrate a thorough understanding of the behavior of the detector system.

  11. Tests of the Monte Carlo simulation of the photon-tagger focal-plane electronics at the MAX IV Laboratory

    International Nuclear Information System (INIS)

    Preston, M.F.; Myers, L.S.; Annand, J.R.M.; Fissum, K.G.; Hansen, K.; Isaksson, L.; Jebali, R.; Lundin, M.

    2014-01-01

    Rate-dependent effects in the electronics used to instrument the tagger focal plane at the MAX IV Laboratory were recently investigated using the novel approach of Monte Carlo simulation to allow for normalization of high-rate experimental data acquired with single-hit time-to-digital converters (TDCs). The instrumentation of the tagger focal plane has now been expanded to include multi-hit TDCs. The agreement between results obtained from data taken using single-hit and multi-hit TDCs demonstrate a thorough understanding of the behavior of the detector system

  12. A silicon strip detector used as a high rate focal plane sensor for electrons in a magnetic spectrometer

    CERN Document Server

    Miyoshi, T; Fujii, Y; Hashimoto, O; Hungerford, E V; Sato, Y; Sarsour, M; Takahashi, T; Tang, L; Ukai, M; Yamaguchi, H

    2003-01-01

    A silicon strip detector was developed as a focal plane sensor for a 300 MeV electron spectrometer and operated in a high rate environment. The detector with 500 mu m pitch provided good position resolution for electrons crossing the focal plane of the magnetic spectrometer system which was mounted in Hall C of the Thomas Jefferson National Accelerator Facility. The design of the silicon strip detector and the performance under high counting rate (<=2.0x10 sup 8 s sup - sup 1 for approx 1000 SSD channels) and high dose are discussed.

  13. Optimization of exit-plane waves restored from HRTEM through-focal series

    International Nuclear Information System (INIS)

    Erni, Rolf; Rossell, Marta D.; Nakashima, Philip N.H.

    2010-01-01

    Atomic-resolution transmission electron microscopy has largely benefited from the implementation of aberration correctors in the imaging part of the microscope. Though the dominant geometrical axial aberrations can in principle be corrected or suitably adjusted, the impact of higher-order aberrations, which are mainly due to the implementation of non-round electron optical elements, on the imaging process remains unclear. Based on a semi-empirical criterion, we analyze the impact of residual aperture aberrations on the quality of exit-plane waves that are retrieved from through-focal series recorded using an aberration-corrected and monochromated instrument which was operated at 300 kV and enabled for an information transfer of ∼0.05 nm. We show that the impact of some of the higher-order aberrations in retrieved exit-plane waves can be balanced by a suitable adjustment of symmetry equivalent lower-order aberrations. We find that proper compensation and correction of 1st and 2nd order aberrations is critical, and that the required accuracy is difficult to achieve. This results in an apparent insensitivity towards residual higher-order aberrations. We also investigate the influence of the detector characteristics on the image contrast. We find that correction for the modulation transfer function results in a contrast gain of up to 40%.

  14. Reproducibility of temporomandibular joint tomography. Influence of shifted X-ray beam and tomographic focal plane on reproducibility

    International Nuclear Information System (INIS)

    Saito, Masashi

    1999-01-01

    Proper tomographic focal plane and x-ray beam direction are the most important factors to obtain accurate images of the temporomandibular joint (TMJ). In this study, to clarify the magnitude of effect of these two factors on the image quality. We evaluated the reproducibility of tomograms by measuring the distortion when the x-ray beam was shifted from the correct center of the object. The effects of the deviation of the tomographic focal plane on image quality were evaluated by the MTF (Modulation Transfer Function). Two types of tomograms, one the plane type, the other the rotational type were used in this study. A TMJ model was made from Teflon for the purpose of evaluation by shifting the x-ray beam. The x-ray images were obtained by tilting the model from 0 to 10 degrees 2-degree increments. These x-ray images were processed for computer image analysis, and then the distance between condyle and the joint space was measured. To evaluate the influence of the shifted tomographic focal plane on image sharpness, the x-ray images from each setting were analyzed by MTF. To obtain the MTF, ''knife-edge'' made from Pb was used. The images were scanned with a microdensitometer at the central focal plane, and 0, 0.5, 1 mm away respectively. The density curves were analyzed by Fourier analysis and the MTF was calculated. The reproducibility of images became worse by shifting the x-ray beam. This tendency was similar for both tomograms. Object characteristics such as anterior and posterior portion of the joint space affected the deterioration of reproducibility of the tomography. The deviation of the tomographic focal plane also decreased the reproducibility of the x-ray images. The rotational type showed a better MTF, but it became seriously unfavorable with slight changes of the tomographic focal plane. Contrarily, the plane type showed a lower MTF, but the image was stable with shifting of the tomographic focal plane. (author)

  15. Development of High-Performance eSWIR HgCdTe-Based Focal-Plane Arrays on Silicon Substrates

    Science.gov (United States)

    Park, J. H.; Pepping, J.; Mukhortova, A.; Ketharanathan, S.; Kodama, R.; Zhao, J.; Hansel, D.; Velicu, S.; Aqariden, F.

    2016-09-01

    We report the development of high-performance and low-cost extended short-wavelength infrared (eSWIR) focal-plane arrays (FPAs) fabricated from molecular beam epitaxial (MBE)-grown HgCdTe on Si-based substrates. High-quality n-type eSWIR HgCdTe (cutoff wavelength ˜2.68 μm at 77 K, electron carrier concentration 5.82 × 1015 cm-3) layers were grown on CdTe/Si substrates by MBE. High degrees of uniformity in composition and thickness were demonstrated over three-inch areas, and low surface defect densities (voids 9.56 × 101 cm-2, micro-defects 1.67 × 103 cm-2) were measured. This material was used to fabricate 320 × 256 format, 30 μm pitch FPAs with a planar device architecture using arsenic implantation to achieve p-type doping. The dark current density of test devices showed good uniformity between 190 K and room temperature, and high-quality eSWIR imaging from hybridized FPAs was obtained with a median dark current density of 2.63 × 10-7 A/cm2 at 193 K with a standard deviation of 1.67 × 10-7 A/cm2.

  16. Examination of cotton fibers and common contaminants using an infrared microscope and a focal-plane array detector

    Science.gov (United States)

    The chemical imaging of cotton fibers and common contaminants in fibers is presented. Chemical imaging was performed with an infrared microscope equipped with a Focal-Plane Array (FPA) detector. Infrared spectroscopy can provide us with information on the structure and quality of cotton fibers. In a...

  17. Performance of an optical filter for the XMM focal plane CCD camera EPIC

    Science.gov (United States)

    Stephan, Karl-Heinz; Reppin, C.; Hirschinger, M.; Maier, H. J.; Frischke, D.; Fuchs, Detlef; Mueller, Peter; Guertler, Peter

    1996-10-01

    We have been developing optical filters for ESA's x-ray astronomy project XMM (x-ray multi mirror mission). Specific CCDs will be used as detectors in the focal plane on board the observatory. Since these detectors are sensitive from the x-ray to the NIR (near infrared) spectral range, x-ray observations require optical filters, which combine a high transparency for photon energies in the soft x-ray region and a high opacity for UV (ultraviolet) and VIS (visible) radiation as well. With respect to the mission goal in orbit three types of flight model filters are designed having different spectral transmittance functions. We report on one of these types, a so-called 'thick' filter, which has been realized within the EQM (electrical qualification model)- phase of the project. The filter features a cut-off in the EUV (extreme ultraviolet) spectral range and suppresses radiation below 10 eV photon energy by more than 8 orders of magnitude. It has an effective aperture of 73 mm without any support structure. A 0.35 micrometer thick polypropylene carrier foil is coated with metallic films of Al and Sn. The manufacturing process, the qualification measurements and the environmental tests are described, and the resulting performance data is presented.

  18. Evolution of miniature detectors and focal plane arrays for infrared sensors

    Science.gov (United States)

    Watts, Louis A.

    1993-06-01

    Sensors that are sensitive in the infrared spectral region have been under continuous development since the WW2 era. A quest for the military advantage of 'seeing in the dark' has pushed thermal imaging technology toward high spatial and temporal resolution for night vision equipment, fire control, search track, and seeker 'homing' guidance sensing devices. Similarly, scientific applications have pushed spectral resolution for chemical analysis, remote sensing of earth resources, and astronomical exploration applications. As a result of these developments, focal plane arrays (FPA) are now available with sufficient sensitivity for both high spatial and narrow bandwidth spectral resolution imaging over large fields of view. Such devices combined with emerging opto-electronic developments in integrated FPA data processing techniques can yield miniature sensors capable of imaging reflected sunlight in the near IR and emitted thermal energy in the Mid-wave (MWIR) and longwave (LWIR) IR spectral regions. Robotic space sensors equipped with advanced versions of these FPA's will provide high resolution 'pictures' of their surroundings, perform remote analysis of solid, liquid, and gas matter, or selectively look for 'signatures' of specific objects. Evolutionary trends and projections of future low power micro detector FPA developments for day/night operation or use in adverse viewing conditions are presented in the following test.

  19. Noise characteristics analysis of short wave infrared InGaAs focal plane arrays

    Science.gov (United States)

    Yu, Chunlei; Li, Xue; Yang, Bo; Huang, Songlei; Shao, Xiumei; Zhang, Yaguang; Gong, Haimei

    2017-09-01

    The increasing application of InGaAs short wave infrared (SWIR) focal plane arrays (FPAs) in low light level imaging requires ultra-low noise FPAs. This paper presents the theoretical analysis of FPA noise, and point out that both dark current and detector capacitance strongly affect the FPA noise. The impact of dark current and detector capacitance on FPA noise is compared in different situations. In order to obtain low noise performance FPAs, the demand for reducing detector capacitance is higher especially when pixel pitch is smaller, integration time is shorter, and integration capacitance is larger. Several InGaAs FPAs were measured and analyzed, the experiments' results could be well fitted to the calculated results. The study found that the major contributor of FPA noise is coupled noise with shorter integration time. The influence of detector capacitance on FPA noise is more significant than that of dark current. To investigate the effect of detector performance on FPA noise, two kinds of photodiodes with different concentration of the absorption layer were fabricated. The detectors' performance and noise characteristics were measured and analyzed, the results are consistent with that of theoretical analysis.

  20. High Dynamic Range adaptive ΔΣ-based Focal Plane Array architecture

    KAUST Repository

    Yao, Shun

    2012-10-16

    In this paper, an Adaptive Delta-Sigma based architecture for High Dynamic Range (HDR) Focal Plane Arrays is presented. The noise shaping effect of the Delta-Sigma modulation in the low end, and the distortion noise induced in the high end of Photo-diode current were analyzed in detail. The proposed architecture can extend the DR for about 20N log2 dB at the high end of Photo-diode current with an N bit Up-Down counter. At the low end, it can compensate for the larger readout noise by employing Extended Counting. The Adaptive Delta-Sigma architecture employing a 4-bit Up-Down counter achieved about 160dB in the DR, with a Peak SNR (PSNR) of 80dB at the high end. Compared to the other HDR architectures, the Adaptive Delta-Sigma based architecture provides the widest DR with the best SNR performance in the extended range.

  1. Decay spectroscopy at SHIP with a new focal plane detector system

    Energy Technology Data Exchange (ETDEWEB)

    Mistry, Andrew K. [Helmholtz Institute Mainz (Germany); Collaboration: SHIP Decay Spectroscopy-Collaboration

    2016-07-01

    Decay spectroscopy of the heaviest elements remains a crucial tool in nuclear structure physics in testing a variety of theoretical models predicting the next proton and neutron shell stabilization region beyond {sup 208}Pb. Experimental measurements of alpha-decay energies and half-lives, ordering and configurations of ground state and excited levels, and the determination of high-K isomers provide necessary information in constraining these models. To this end, a new focal plane detection system for decay spectroscopy has been designed and developed at GSI for the SHIP separator. It consists of a double sided silicon strip implantation detector surrounded by 4 single sided silicon strip detectors on each side in a box formation with a compact design, allowing for good germanium solid angle coverage for gamma ray detection. The data acquisition is based on FEBEX flash ADC modules, developed at GSI, for digital signal processing enables an almost deadtime free system. Recently, a commissioning run was successfully performed using the device. In my talk I present recent highlights of decay spectroscopy at SHIP, and demonstrate results from measurements assessing the performance of the new setup.

  2. New data acquisition system for the focal plane polarimeter of the Grand Raiden spectrometer

    International Nuclear Information System (INIS)

    Tamii, A.; Sakaguchi, H.; Takeda, H.; Yosoi, M.; Akimune, H.; Fujiwara, M.; Ogata, H.; Tanaka, M.; Togawa, H.

    1996-01-01

    This paper describes a new data acquisition system for the focal plane polarimeter of the Grand Raiden spectrometer at the Research Center for Nuclear Physics (RCNP) in Osaka, Japan. Data are acquired by a Creative Electronic Systems (CES) Starburst, which is a CAMAC auxiliary crate controller equipped with a Digital Equipment Corporation (DEC) J11 microprocessor., The data on the Starburst are transferred to a VME single-board computer. A VME reflective memory module broadcasts the data to other systems through a fiber-optic link. A data transfer rate of 2.0 Mbytes/s between VME modules has been achieved by reflective memories. This rate includes the overhead of buffer management. The overall transfer rate, however, is limited by the performance of the Starburst to about 160 Kbytes/s at maximum. In order to further improve the system performance, the authors developed a new readout module called the Rapid Data Transfer Module (RDTM). RDTM's transfer data from LeCroy PCOS III's or 4298's, and FERA/FERET's directly to CES 8170 High Speed Memories (HSM) in VME crates. The data transfer rate of the RDTM from PCOS III's to the HSM is about 4 Mbytes/s

  3. Performance of Hg1-xCdxTe infrared focal plane array at elevated temperature

    Science.gov (United States)

    Singh, Anand; Pal, Ravinder

    2017-04-01

    The simulated optical and electrical performance of the infrared HgCdTe focal plane array (FPA) for elevated operation temperature is reported. The depleted absorber layer is explored for equilibrium mode of operation up to 160 K. A resonant cavity is created to improve photon-matter interaction and hence, reduces the required absorption volume. The volume of the active region of HgCdTe detector is reduced by 70% in this manner. Dark current density is decreased without compromising the quantum efficiency. The effect of the reduced band filling effect leading to higher absorption coefficient and more efficient utilization of incident flux is employed. High quantum efficiency is achieved in a thin compositionally graded n+/ν/π/p HgCdTe photo-diode. This architecture helps to minimize the requirement of charge handling capacity in the CMOS read-out integrated circuit (ROIC) as the operation temperature is increased. Quantum efficiency ˜30% or above is shown to be sufficient for Noise Equivalent Temperature Difference (NETD) less than 20 mK with the reported design.

  4. Test stand for non-uniformity correction of microbolometer focal plane arrays used in thermal cameras

    Science.gov (United States)

    Krupiński, Michał; Bareła, Jaroslaw; Firmanty, Krzysztof; Kastek, Mariusz

    2013-10-01

    Uneven response of particular detectors (pixels) to the same incident power of infrared radiation is an inherent feature of microbolometer focal plane arrays. As a result an image degradation occurs, known as Fixed Pattern Noise (FPN), which distorts the thermal representation of an observed scene and impairs the parameters of a thermal camera. In order to compensate such non-uniformity, several NUC correction methods are applied in digital data processing modules implemented in thermal cameras. Coefficients required to perform the non-uniformity correction procedure (NUC coefficients) are determined by calibrating the camera against uniform radiation sources (blackbodies). Non-uniformity correction is performed in a digital processing unit in order to remove FPN pattern in the registered thermal images. Relevant correction coefficients are calculated on the basis of recorded detector responses to several values of radiant flux emitted from reference IR radiation sources (blackbodies). The measurement of correction coefficients requires specialized setup, in which uniform, extended radiation sources with high temperature stability are one of key elements. Measurement stand for NUC correction developed in Institute of Optoelectronics, MUT, comprises two integrated extended blackbodies with the following specifications: area 200×200 mm, stabilized absolute temperature range +15 °C÷100 °C, and uniformity of temperature distribution across entire surface +/-0.014 °C. Test stand, method used for the measurement of NUC coefficients and the results obtained during the measurements conducted on a prototype thermal camera will be presented in the paper.

  5. Life test of the InGaAs focal plane arrays detector for space applications

    Science.gov (United States)

    Zhu, Xian-Liang; Zhang, Hai-Yan; Li, Xue; Huang, Zhang-Cheng; Gong, Hai-Mei

    2017-08-01

    The short-wavelength infrared (SWIR) InGaAs focal plane array (FPA) detector consists of infrared detector chip, readout integrated circuit (ROIC), and flip-chip bonding interconnection by Indium bump. In order to satisfy space application requirements for failure rates or Mean Time to Failure (MTTF), which can only be demonstrated with the large number of detectors manufactured, the single pixel in InGaAs FPAs was chosen as the research object in this paper. The constant-stress accelerated life tests were carried out at 70°C 80°C 90°C and100°C. The failed pixels increased gradually during more than 14000 hours at each elevated temperatures. From the random failure data the activation energy was estimated to be 0.46eV, and the average lifetime of a single pixel in InGaAs FPAs was estimated to be longer than 1E+7h at the practical operating temperature (5°C).

  6. Coronagraph Focal-Plane Phase Masks Based on Photonic Crystal Technology: Recent Progress and Observational Strategy

    Science.gov (United States)

    Murakami, Naoshi; Nishikawa, Jun; Sakamoto, Moritsugu; Ise, Akitoshi; Oka, Kazuhiko; Baba, Naoshi; Murakami, Hiroshi; Tamura, Motohide; Traub, Wesley A.; Mawet, Dimitri; hide

    2012-01-01

    Photonic crystal, an artificial periodic nanostructure of refractive indices, is one of the attractive technologies for coronagraph focal-plane masks aiming at direct imaging and characterization of terrestrial extrasolar planets. We manufactured the eight-octant phase mask (8OPM) and the vector vortex mask (VVM) very precisely using the photonic crystal technology. Fully achromatic phase-mask coronagraphs can be realized by applying appropriate polarization filters to the masks. We carried out laboratory experiments of the polarization-filtered 8OPM coronagraph using the High-Contrast Imaging Testbed (HCIT), a state-of-the-art coronagraph simulator at the Jet Propulsion Laboratory (JPL). We report the experimental results of 10-8-level contrast across several wavelengths over 10% bandwidth around 800nm. In addition, we present future prospects and observational strategy for the photonic-crystal mask coronagraphs combined with differential imaging techniques to reach higher contrast. We proposed to apply a polarization-differential imaging (PDI) technique to the VVM coronagraph, in which we built a two-channel coronagraph using polarizing beam splitters to avoid a loss of intensity due to the polarization filters. We also proposed to apply an angular-differential imaging (ADI) technique to the 8OPM coronagraph. The 8OPM/ADI mode avoids an intensity loss due to a phase transition of the mask and provides a full field of view around central stars. We present results of preliminary laboratory demonstrations of the PDI and ADI observational modes with the phase-mask coronagraphs.

  7. The Focal Plane Assembly for the Athena X-Ray Integral Field Unit Instrument

    Science.gov (United States)

    Jackson, B. D.; Van Weers, H.; van der Kuur, J.; den Hartog, R.; Akamatsu, H.; Argan, A.; Bandler, S. R.; Barbera, M.; Barret, D.; Bruijn, M. P.; hide

    2016-01-01

    This paper summarizes a preliminary design concept for the focal plane assembly of the X-ray Integral Field Unit on the Athena spacecraft, an imaging microcalorimeter that will enable high spectral resolution imaging and point-source spectroscopy. The instrument's sensor array will be a 3840-pixel transition edge sensor (TES) microcalorimeter array, with a frequency domain multiplexed SQUID readout system allowing this large-format sensor array to be operated within the thermal constraints of the instrument's cryogenic system. A second TES detector will be operated in close proximity to the sensor array to detect cosmic rays and secondary particles passing through the sensor array for off-line coincidence detection to identify and reject events caused by the in-orbit high-energy particle background. The detectors, operating at 55 mK, or less, will be thermally isolated from the instrument cryostat's 2 K stage, while shielding and filtering within the FPA will allow the instrument's sensitive sensor array to be operated in the expected environment during both on-ground testing and in-flight operation, including stray light from the cryostat environment, low-energy photons entering through the X-ray aperture, low-frequency magnetic fields, and high-frequency electric fields.

  8. High-resolution focal plane array IR detection modules and digital signal processing technologies at AIM

    Science.gov (United States)

    Cabanski, Wolfgang A.; Breiter, Rainer; Koch, R.; Mauk, Karl-Heinz; Rode, Werner; Ziegler, Johann; Eberhardt, Kurt; Oelmaier, Reinhard; Schneider, Harald; Walther, Martin

    2000-07-01

    Full video format focal plane array (FPA) modules with up to 640 X 512 pixels have been developed for high resolution imaging applications in either mercury cadmium telluride (MCT) mid wave (MWIR) infrared (IR) or platinum silicide (PtSi) and quantum well infrared photodetector (QWIP) technology as low cost alternatives to MCT for high performance IR imaging in the MWIR or long wave spectral band (LWIR). For the QWIP's, a new photovoltaic technology was introduced for improved NETD performance and higher dynamic range. MCT units provide fast frame rates > 100 Hz together with state of the art thermal resolution NETD hardware platforms and software for image visualization and nonuniformity correction including scene based self learning algorithms had to be developed to accomplish for the high data rates of up to 18 M pixels/s with 14-bit deep data, allowing to take into account nonlinear effects to access the full NETD by accurate reduction of residual fixed pattern noise. The main features of these modules are summarized together with measured performance data for long range detection systems with moderately fast to slow F-numbers like F/2.0 - F/3.5. An outlook shows most recent activities at AIM, heading for multicolor and faster frame rate detector modules based on MCT devices.

  9. The scintillating fiber focal plane detector for the use of Kaos as a double arm spectrometer

    International Nuclear Information System (INIS)

    Ayerbe Gayoso, Carlos Antonio

    2012-01-01

    detector focal plane to the primary vertex. This transfer matrix has been calculated to first order using beam transport optics and has been checked by quasielastic scattering off a carbon target, where the full kinematics is determined by measuring the recoil proton momentum. The reconstruction accuracy for the emission parameters at the quasielastic vertex was found to be on the order of 0.3 % in first test realized. The design, construction process, commissioning, testing and characterization of the fiber hodoscope are presented in this work which has been developed at the Institut fuer Kernphysik of the Johannes Gutenberg - Universitaet Mainz.

  10. The scintillating fiber focal plane detector for the use of Kaos as a double arm spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Ayerbe Gayoso, Carlos Antonio

    2012-05-25

    calculating the transfer matrix of track parameters from the fiber detector focal plane to the primary vertex. This transfer matrix has been calculated to first order using beam transport optics and has been checked by quasielastic scattering off a carbon target, where the full kinematics is determined by measuring the recoil proton momentum. The reconstruction accuracy for the emission parameters at the quasielastic vertex was found to be on the order of 0.3 % in first test realized. The design, construction process, commissioning, testing and characterization of the fiber hodoscope are presented in this work which has been developed at the Institut fuer Kernphysik of the Johannes Gutenberg - Universitaet Mainz.

  11. SWIR HgCdTe avalanche photiode focal plane array performances evaluation

    Science.gov (United States)

    de Borniol, E.; Rothman, J.; Salveti, F.; Feautrier, P.

    2017-11-01

    One of the main challenges of modern astronomical instruments like adaptive optics (AO) systems or fringe trackers is to deal with the very low photons flux detection scenarios. The typical timescale of atmospheric turbulences being in the range of some tens of milliseconds, infrared wavefront sensors for AO systems needs frame rates higher than 1 KHz leading to integration times lower than 1 ms. This integration time associated with a low irradiance results in a few number of integrated photons per frame per pixel. To preserve the information coming from this weak signal, the focal plane array (FPA) has to present a low read out noise, a high quantum efficiency and a low dark current. Up to now, the output noise of high speed near infrared sensors is limited by the silicon read out circuit noise. The use of HgCdTe avalanche photodiodes with high gain at moderate reverse bias and low excess noise seems then a logical way to reduce the impact of the read noise on images signal to noise ratio. These low irradiance passive imaging applications with integration times in the millisecond range needs low photodiode dark current and low background current. These requirements lead to the choice of the photodiode cut off wavelength. The short wave infrared (SWIR) around 3 μm is a good compromise between the gain that can be obtain for a given APD bias and the background and dark current. The CEA LETI HgCdTe APD technology, and a fine analysis of the gain curve characteristic are presented in [1] and won't be detailed here. The response time of the APD is also a key factor for a high frame rate FPA. This parameter has been evaluated in [2] and the results shows cut off frequencies in the GHz range. In this communication we report the performances of a SWIR APD FPA designed and fabricated by CEA LETI and SOFRADIR for astrophysical applications. This development was made in the frame of RAPID, a 4 years R&D project funded by the French FUI (Fond Unique Interministériel). This

  12. Automated optical testing of LWIR objective lenses using focal plane array sensors

    Science.gov (United States)

    Winters, Daniel; Erichsen, Patrik; Domagalski, Christian; Peter, Frank; Heinisch, Josef; Dumitrescu, Eugen

    2012-10-01

    The image quality of today's state-of-the-art IR objective lenses is constantly improving while at the same time the market for thermography and vision grows strongly. Because of increasing demands on the quality of IR optics and increasing production volumes, the standards for image quality testing increase and tests need to be performed in shorter time. Most high-precision MTF testing equipment for the IR spectral bands in use today relies on the scanning slit method that scans a 1D detector over a pattern in the image generated by the lens under test, followed by image analysis to extract performance parameters. The disadvantages of this approach are that it is relatively slow, it requires highly trained operators for aligning the sample and the number of parameters that can be extracted is limited. In this paper we present lessons learned from the R and D process on using focal plane array (FPA) sensors for testing of long-wave IR (LWIR, 8-12 m) optics. Factors that need to be taken into account when switching from scanning slit to FPAs are e.g.: the thermal background from the environment, the low scene contrast in the LWIR, the need for advanced image processing algorithms to pre-process camera images for analysis and camera artifacts. Finally, we discuss 2 measurement systems for LWIR lens characterization that we recently developed with different target applications: 1) A fully automated system suitable for production testing and metrology that uses uncooled microbolometer cameras to automatically measure MTF (on-axis and at several o-axis positions) and parameters like EFL, FFL, autofocus curves, image plane tilt, etc. for LWIR objectives with an EFL between 1 and 12mm. The measurement cycle time for one sample is typically between 6 and 8s. 2) A high-precision research-grade system using again an uncooled LWIR camera as detector, that is very simple to align and operate. A wide range of lens parameters (MTF, EFL, astigmatism, distortion, etc.) can be

  13. Vacuum packaging of InGaAs focal plane array with four-stage thermoelectric cooler

    Science.gov (United States)

    Mo, De-feng; Liu, Da-fu; Yang, Li-yi; Xu, Qin-fei; Li, Xue

    2013-09-01

    The InGaAs focal plane array (FPA) detectors, covering the near-infrared 1~2.4 μm wavelength range, have been developed for application in space-based spectroscopy of the Earth atmosphere. This paper shows an all-metal vacuum package design for area array InGaAs detector of 1024×64 pixels, and its architecture will be given. Four-stage thermoelectric cooler (TEC) is used to cool down the FPA chip. To acquire high heat dissipation for TEC's Joule-heat, tungsten copper (CuW80) and kovar (4J29) is used as motherboard and cavity material respectively which joined by brazing. The heat loss including conduction, convection and radiation is analyzed. Finite element model is established to analyze the temperature uniformity of the chip substrate which is made of aluminum nitride (AlN). The performance of The TEC with and without heat load in vacuum condition is tested. The results show that the heat load has little influence to current-voltage relationship of TEC. The temperature difference (ΔT) increases as the input current increases. A linear relationship exists between heat load and ΔT of the TEC. Theoretical analysis and calculation show that the heat loss of radiation and conduction is about 187 mW and 82 mW respectively. Considering the Joule-heat of readout circuit and the heat loss of radiation and conduction, the FPA for a 220 K operation at room temperature can be achieved. As the thickness of AlN chip substrate is thicker than 1 millimeter, the temperature difference can be less than 0.3 K.

  14. Infrared detectors, focal plane arrays, and imaging sensors; Proceedings of the Meeting, Orlando, FL, Mar. 30, 31, 1989

    Science.gov (United States)

    Dereniak, Eustace L.; Sampson, Robert T.

    1989-10-01

    The present conference on advancements in IR detectors, Schottky-barrier focal plane arrays, CCD image analysis, and HgCdTe materials gives attention to a 256 x 256 PtSi array for IR astronomy, proposals for a second-generation meteosat's advanced optical payload, cryogenic bipolar technology for on-focal-plane signal processing, a parallel cellular processing system for fast generation of perspective plots, and ultrahigh-speed CCD image sensors for scanning applications. Also discussed are MBE GaAs rib waveguide experiments at 10.6 microns, an interferometric thermal detector, the development status of superconducting IR detector research, the absorption coefficients of n-type Hg(1-x)Cd(x)Te samples, and the influence of the surface channel on crosstalk in HgCdTe photovoltaic arrays.

  15. A Readout Integrated Circuit (ROIC) employing self-adaptive background current compensation technique for Infrared Focal Plane Array (IRFPA)

    Science.gov (United States)

    Zhou, Tong; Zhao, Jian; He, Yong; Jiang, Bo; Su, Yan

    2018-05-01

    A novel self-adaptive background current compensation circuit applied to infrared focal plane array is proposed in this paper, which can compensate the background current generated in different conditions. Designed double-threshold detection strategy is to estimate and eliminate the background currents, which could significantly reduce the hardware overhead and improve the uniformity among different pixels. In addition, the circuit is well compatible to various categories of infrared thermo-sensitive materials. The testing results of a 4 × 4 experimental chip showed that the proposed circuit achieves high precision, wide application and high intelligence. Tape-out of the 320 × 240 readout circuit, as well as the bonding, encapsulation and imaging verification of uncooled infrared focal plane array, have also been completed.

  16. Angular acceptance analysis of an infrared focal plane array with a built-in stationary Fourier transform spectrometer.

    Science.gov (United States)

    Gillard, Frédéric; Ferrec, Yann; Guérineau, Nicolas; Rommeluère, Sylvain; Taboury, Jean; Chavel, Pierre

    2012-06-01

    Stationary Fourier transform spectrometry is an interesting concept for building reliable field or embedded spectroradiometers, especially for the mid- and far- IR. Here, a very compact configuration of a cryogenic stationary Fourier transform IR (FTIR) spectrometer is investigated, where the interferometer is directly integrated in the focal plane array (FPA). We present a theoretical analysis to explain and describe the fringe formation inside the FTIR-FPA structure when illuminated by an extended source positioned at a finite distance from the detection plane. The results are then exploited to propose a simple front lens design compatible with a handheld package.

  17. A NEXT GENERATION MULTI-BEAM FOCAL PLANE ARRAY RECEIVER OF TRAO FOR 86-115 GHZ BAND

    Directory of Open Access Journals (Sweden)

    Moon-Hee Chung

    2006-03-01

    Full Text Available The noise temperature of existing millimeter-wave receivers is already within two or three times quantum noise limit. One of practical ways to increase the observation speed of single dish radio telescope without longer integration time is use of multi-beam focal plane array receiver as demonstrated in several large single dish radio telescopes. In this context the TRAO (Taeduk Radio Astronomy Observatory, which operates a 143n Cassegrain radio telescope, is planning to develop a 4 x 4 beams focal plane array SIS receiver system for 86-115 GHz band. Even though millimeter-wave HEMT LNA-based receivers approach the noise temperature comparable to the SIS receiver at W-band, it is believed that the receiver based on SIS mixer seems to offer a bit more advantages. The critical part of the multi-beam array receiver will be sideband separating SIS mixers. Employing such a type of SIS mixer makes it possible to simplify the quasi-optics of receiver. Otherwise, an SSB filter should be used in front of the mixer or some sophisticated post-processing of observation data is needed. In this paper we will present a preliminary design concept and components needed for the development of a new 3 mm band multi-beam focal plane array receiver.

  18. PLEIADES HR IN FLIGHT GEOMETRICAL CALIBRATION : LOCATION AND MAPPING OF THE FOCAL PLANE

    Directory of Open Access Journals (Sweden)

    F. de Lussy

    2012-07-01

    Full Text Available The Pleiades system, ORFEO system optical component (Optical and Radar Federated Earth Observation consists of a constellation of two satellites for very High Resolution panchromatic and multispectral optical observation of the Earth. Its mission is to cover all European civilian needs (mapping, tracking floods and fires and defence in the category of metric resolution: 0.7m Nadir. The first Pleiades satellite was launched at the end of last year. One of the key objectives of the Pleiades HR (PHR project is to achieve a location accuracy that will allow the use of images in GIS (Geographical Information System without geometrical model improvement by refining on ground control points. The image location without refined model was specified with the precision of the most commonly used tool ie the civil GPS. So the location accuracy has been specified at less than 12m for 90% of the images on a nominal satellite configuration. Very special care has been taken all along the PHR project realization to achieve this very good location accuracy. The final touch is given during the in-orbit commissioning phase which lasts until June 2012. The geometric quality implies to tune the parameters involved in the geolocation model (geometric calibration: besides attitude and orbit restitution tuning (not considered here, it consists in estimating the biases between the instrument orientation and the AOCS reference frame, and also the sight line of each detector in the focal plane. This is called static geometrical model. The analysis of dynamic perturbations outside of the model are the second most important image quality objective of in-flight commissioning, not described in this paper. Finally “image quality assessment” consists in evaluating the image quality obtained in the final products. For geolocation model, it is quantified by the absolute geolocation and the pointing accuracies, and it is a main contributor in length alteration and planimetric and

  19. 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.

  20. A DSP-based readout and online processing system for a new focal-plane polarimeter at AGOR

    Energy Technology Data Exchange (ETDEWEB)

    Hagemann, M.; Bassini, R.; Berg, A.M. van den; Ellinghaus, F.; Frekers, D.; Hannen, V.M.; Haeupke, T.; Heyse, J.; Jacobs, E.; Kirsch, M.; Kruesemann, B.; Rakers, S.; Sohlbach, H.; Woertche, H.J. E-mail: wortche@ikp.uni-muenster.de

    1999-11-21

    A Focal-Plane Polarimeter (FPP) for the large acceptance Big-Bite Spectrometer (BBS) at AGOR using a novel readout architecture has been commissioned at the KVI Groningen. The instrument is optimized for medium-energy polarized proton scattering near or at 0 deg. . For the handling of the high counting rates at extreme forward angles and for the suppression of small-angle scattering in the graphite analyzer, a high-performance data processing DSP system connecting to the LeCroy FERA and PCOS ECL bus architecture has been made operational and tested successfully. Details of the system and the functions of the various electronic components are described.

  1. Imaging with a 90 frames/s microbolometer focal plane array and high-power terahertz free electron laser

    International Nuclear Information System (INIS)

    Dem'yanenko, M. A.; Esaev, D. G.; Knyazev, B. A.; Vinokurov, N. A.; Kulipanov, G. N.

    2008-01-01

    An uncooled microbolometer focal plane array (FPA) has been developed and used for imaging of objects illuminated by monochromatic coherent radiation of a free electron laser tunable in the range of 1.25-2.5 THz. A sensitivity threshold of 1.3x10 -3 W/cm 2 was obtained for the FPA with a homemade absolute interferometric power meter. Videos up to 90 frames/s were recorded in both transmission and reflection/scattering modes. When objects were illuminated by laser radiation scattered by a rough metal surface, speckled images were observed. Good quality terahertz images were achieved through the fast rotation of the scatterer

  2. The investigation of properties of short-lived SF isotopes (Z > 100 at the focal plane of VASSILISSA separator

    Directory of Open Access Journals (Sweden)

    Svirikhin Alexandr

    2013-12-01

    Full Text Available For experiments aimed at the study of spontaneous fission of transfermium nuclei improvements in the focal plane detector system of recoil separator VASSILISSA have been made. A neutron detector consisting of 54 3He-filled counters has been mounted around the focal-plane detector chamber. The reaction 48Ca + 206Pb = 2n + 252No is used for tuning the separator settings and calibrating the detector system with the spontaneous fission of the 252No. The average neutron number per 252No spontaneous fission event is as large as ν̅ = 4.06 ± 0.12. The short-lived heavy isotopes 244,246Fm, produced in the complete fusion reactions 40Ar + 206,208Pb, are investigated. The average number of neutrons per spontaneous fission of 244,246Fm from the experimental data were (ν̅ = 3.3 ± 0.3 and (ν̅ = 3.55 ± 0.50, respectively. Both values are determined for the first time.

  3. A simulation study on the focal plane detector of the LAUE project

    Science.gov (United States)

    Khalil, M.; Frontera, F.; Caroli, E.; Virgilli, E.; Valsan, V.

    2015-06-01

    The LAUE project, supported by the Italian Space Agency (ASI), is devoted to the development of a long focal length (even 20 m or longer) Laue lens for gamma ray astronomy between 80 and 600 keV. These lenses take advantage of Bragg diffraction to focus radiation onto a small spot drastically improving the signal to noise ratio as well as reducing the required size of the detector significantly. In this paper we present a Monte-Carlo simulation study with MEGALIB to optimize, for space applications, the detector size to achieve high detection efficiency, and to optimize the position resolution of the detector to reconstruct the Point Spread Function of the lens considered for the LAUE project. Then we will show simulations, using the SILVACO semiconductor simulation toolkit, on the optimized detector to estimate its capacitance per channel and depletion voltage. In all of the simulations, two materials were compared; a low density material (Silicon) and a high density material (Germanium).

  4. Conversion electron spectroscopy at the FMA focal plane: Decay studies of proton-rich N {approximately} 82 nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Nisius, D.; Janssens, R.V.F.; Ahmad, I. [and others

    1995-08-01

    The FMA has proven to be an ideal instrument for the detailed study of the decay of microsecond isomers behind the focal plane following mass selection. In reactions leading to the population of nuclei with isomeric lifetimes longer than their flight time through the device, decay gamma rays and conversion electrons can be detected in an environment free from the backgrounds of prompt radiation and delta electrons. This was a very successful technique to study proton (h{sub 11/2}){sup n} seniority isomers in nuclei with Z > 64 and N {approximately} 82. Since isomeric decay gamma rays are emitted isotropically, conversion electrons are essential for the assignment of multipolarities in these nuclei. Furthermore, the low-energy transitions that depopulate isomeric states are typically highly converted and can escape gamma-ray detection, but they can be identified by their conversion electrons.

  5. A pipelined architecture for real time correction of non-uniformity in infrared focal plane arrays imaging system using multiprocessors

    Science.gov (United States)

    Zou, Liang; Fu, Zhuang; Zhao, YanZheng; Yang, JunYan

    2010-07-01

    This paper proposes a kind of pipelined electric circuit architecture implemented in FPGA, a very large scale integrated circuit (VLSI), which efficiently deals with the real time non-uniformity correction (NUC) algorithm for infrared focal plane arrays (IRFPA). Dual Nios II soft-core processors and a DSP with a 64+ core together constitute this image system. Each processor undertakes own systematic task, coordinating its work with each other's. The system on programmable chip (SOPC) in FPGA works steadily under the global clock frequency of 96Mhz. Adequate time allowance makes FPGA perform NUC image pre-processing algorithm with ease, which has offered favorable guarantee for the work of post image processing in DSP. And at the meantime, this paper presents a hardware (HW) and software (SW) co-design in FPGA. Thus, this systematic architecture yields an image processing system with multiprocessor, and a smart solution to the satisfaction with the performance of the system.

  6. A simulation study on the focal plane detector of the LAUE project

    International Nuclear Information System (INIS)

    Khalil, M.; Frontera, F.; Caroli, E.; Virgilli, E.; Valsan, V.

    2015-01-01

    The LAUE project, supported by the Italian Space Agency (ASI), is devoted to the development of a long focal length (even 20 m or longer) Laue lens for gamma ray astronomy between 80 and 600 keV. These lenses take advantage of Bragg diffraction to focus radiation onto a small spot drastically improving the signal to noise ratio as well as reducing the required size of the detector significantly. In this paper we present a Monte-Carlo simulation study with MEGALIB to optimize, for space applications, the detector size to achieve high detection efficiency, and to optimize the position resolution of the detector to reconstruct the Point Spread Function of the lens considered for the LAUE project. Then we will show simulations, using the SILVACO semiconductor simulation toolkit, on the optimized detector to estimate its capacitance per channel and depletion voltage. In all of the simulations, two materials were compared; a low density material (Silicon) and a high density material (Germanium). - Highlights: • The quantized Hall plateaus and Shubnikov de Haas oscillations in transition metal doped topological insulators are observed. • The evidence of a two-dimensional/layered transport of the bulk electrons is reported. • An obvious ferromagnetism in doped topological insulators is observed. • Care should be taken to pindown the transport of the topological SS in topological insulators

  7. A simulation study on the focal plane detector of the LAUE project

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, M., E-mail: mkhalil@in2p3.fr [APC Laboratory, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13 (France); Department of Physics and Earth Sciences, University of Ferrara, Via Saragat, 1, 44100 Ferrara (Italy); Frontera, F. [Department of Physics and Earth Sciences, University of Ferrara, Via Saragat, 1, 44100 Ferrara (Italy); INAF/IASF-Bologna, Via P. Gobetti 101, Bologna (Italy); Caroli, E. [INAF/IASF-Bologna, Via P. Gobetti 101, Bologna (Italy); Virgilli, E.; Valsan, V. [Department of Physics and Earth Sciences, University of Ferrara, Via Saragat, 1, 44100 Ferrara (Italy)

    2015-06-21

    The LAUE project, supported by the Italian Space Agency (ASI), is devoted to the development of a long focal length (even 20 m or longer) Laue lens for gamma ray astronomy between 80 and 600 keV. These lenses take advantage of Bragg diffraction to focus radiation onto a small spot drastically improving the signal to noise ratio as well as reducing the required size of the detector significantly. In this paper we present a Monte-Carlo simulation study with MEGALIB to optimize, for space applications, the detector size to achieve high detection efficiency, and to optimize the position resolution of the detector to reconstruct the Point Spread Function of the lens considered for the LAUE project. Then we will show simulations, using the SILVACO semiconductor simulation toolkit, on the optimized detector to estimate its capacitance per channel and depletion voltage. In all of the simulations, two materials were compared; a low density material (Silicon) and a high density material (Germanium). - Highlights: • The quantized Hall plateaus and Shubnikov de Haas oscillations in transition metal doped topological insulators are observed. • The evidence of a two-dimensional/layered transport of the bulk electrons is reported. • An obvious ferromagnetism in doped topological insulators is observed. • Care should be taken to pindown the transport of the topological SS in topological insulators.

  8. THE IMAGING PROPERTIES OF THE GAS PIXEL DETECTOR AS A FOCAL PLANE POLARIMETER

    Energy Technology Data Exchange (ETDEWEB)

    Fabiani, S.; Costa, E.; Del Monte, E.; Muleri, F.; Soffitta, P.; Rubini, A. [INAF-IAPS, via del Fosso del Cavaliere 100, I-00133 Roma (Italy); Bellazzini, R.; Brez, A.; De Ruvo, L.; Minuti, M.; Pinchera, M.; Sgró, C.; Spandre, G. [INFN Sezione di Pisa, Largo B. Pontecorvo, 3, I-56127 Pisa (Italy); Spiga, D.; Tagliaferri, G.; Pareschi, G.; Basso, S.; Citterio, O. [INAF-Osservatorio Astronomico di Brera, via Brera 28, I-20121 Milano (Italy); Burwitz, V.; Burkert, W., E-mail: sergio.fabiani@iaps.inaf.it [Max-Planck-Institut für extraterrestrische Physik, Gautinger Str. 45, D-82061 Neuired (Germany); and others

    2014-06-01

    X-rays are particularly suited to probing the physics of extreme objects. However, despite the enormous improvements of X-ray astronomy in imaging, spectroscopy, and timing, polarimetry remains largely unexplored. We propose the photoelectric polarimeter Gas Pixel Detector (GPD) as a candidate instrument to fill the gap created by more than 30 yr without measurements. The GPD, in the focus of a telescope, will increase the sensitivity of orders of magnitude. Moreover, since it can measure the energy, the position, the arrival time, and the polarization angle of every single photon, it allows us to perform polarimetry of subsets of data singled out from the spectrum, the light curve, or an image of the source. The GPD has an intrinsic, very fine imaging capability, and in this work we report on the calibration campaign carried out in 2012 at the PANTER X-ray testing facility of the Max-Planck-Institut für extraterrestrische Physik of Garching (Germany) in which, for the first time, we coupled it with a JET-X optics module with a focal length of 3.5 m and an angular resolution of 18 arcsec at 4.5 keV. This configuration was proposed in 2012 aboard the X-ray Imaging Polarimetry Explorer (XIPE) in response to the ESA call for a small mission. We derived the imaging and polarimetric performance for extended sources like pulsar wind nebulae and supernova remnants as case studies for the XIPE configuration and also discuss possible improvements by coupling the detector with advanced optics that have a finer angular resolution and larger effective areas to study extended objects with more detail.

  9. RMT focal plane sensitivity to seismic network geometry and faulting style

    Science.gov (United States)

    Johnson, Kendra L.; Hayes, Gavin; Herrmann, Robert B.; Benz, Harley M.; McNamara, Daniel E.; Bergman, Eric A.

    2016-01-01

    Modern tectonic studies often use regional moment tensors (RMTs) to interpret the seismotectonic framework of an earthquake or earthquake sequence; however, despite extensive use, little existing work addresses RMT parameter uncertainty. Here, we quantify how network geometry and faulting style affect RMT sensitivity. We examine how data-model fits change with fault plane geometry (strike and dip) for varying station configurations. We calculate the relative data fit for incrementally varying geometries about a best-fitting solution, applying our workflow to real and synthetic seismograms for both real and hypothetical station distributions and earthquakes. Initially, we conduct purely observational tests, computing RMTs from synthetic seismograms for hypothetical earthquakes and a series of well-behaved network geometries. We then incorporate real data and station distributions from the International Maule Aftershock Deployment (IMAD), which recorded aftershocks of the 2010 MW 8.8 Maule earthquake, and a set of regional stations capturing the ongoing earthquake sequence in Oklahoma and southern Kansas. We consider RMTs computed under three scenarios: (1) real seismic records selected for high data quality; (2) synthetic seismic records with noise computed for the observed source-station pairings and (3) synthetic seismic records with noise computed for all possible station-source pairings. To assess RMT sensitivity for each test, we observe the ‘fit falloff’, which portrays how relative fit changes when strike or dip varies incrementally; we then derive the ranges of acceptable strikes and dips by identifying the span of solutions with relative fits larger than 90 per cent of the best fit. For the azimuthally incomplete IMAD network, Scenario 3 best constrains fault geometry, with average ranges of 45° and 31° for strike and dip, respectively. In Oklahoma, Scenario 3 best constrains fault dip with an average range of 46°; however, strike is best constrained

  10. Small-pixel long wavelength infrared focal plane arrays based on InAs/GaSb Type-II superlattice

    Science.gov (United States)

    Han, Xi; Jiang, Dongwei; Wang, Guowei; Hao, Hongyue; Sun, Yaoyao; Jiang, Zhi; Lv, Yuexi; Guo, Chunyan; Xu, Yingqiang; Niu, Zhichuan

    2018-03-01

    The paper reports a 640 × 512 long wavelength infrared focal plane arrays (FPAs) with 15 × 15 μm2 pixels pitch based on the type II InAs/GaSb superlattice. Material grown on a 3 in. GaSb substrate exhibits a 50% cutoff wavelength of 10.2 μm across the entire wafer. The peak quantum efficiency of the detector reaches 28% at 9.1 μm without anti-reflecting coating. Maximal resistance-area products of 8.95 Ω·cm2 at 77 K and 24.4 Ω·cm2 at 45 K are achieved in a single element device indicating that the generation-recombination and tunneling mechanisms dominate the device dark current, respectively. The peak Johnson Detectivity reaches 9.66 × 1011 cm Hz1/2/W at 9.1 μm with the bias voltage of 80 mV. In the whole zone, the operability and non-uniformity for the responsivity are 97.74% and 6.41% respectively. The average noise equivalent temperature difference of 31.9 mK at 77 K is achieved with an integration time of 0.5 ms, a 300 K background and f/2 optics.

  11. Identification and Quantification of Microplastics in Wastewater Using Focal Plane Array-Based Reflectance Micro-FT-IR Imaging.

    Science.gov (United States)

    Tagg, Alexander S; Sapp, Melanie; Harrison, Jesse P; Ojeda, Jesús J

    2015-06-16

    Microplastics (microplastics in these matrices has not been investigated. Although efficient methods for the analysis of microplastics in sediment samples and marine organisms have been published, no methods have been developed for detecting these pollutants within organic-rich wastewater samples. In addition, there is no standardized method for analyzing microplastics isolated from environmental samples. In many cases, part of the identification protocol relies on visual selection before analysis, which is open to bias. In order to address this, a new method for the analysis of microplastics in wastewater was developed. A pretreatment step using 30% hydrogen peroxide (H2O2) was employed to remove biogenic material, and focal plane array (FPA)-based reflectance micro-Fourier-transform (FT-IR) imaging was shown to successfully image and identify different microplastic types (polyethylene, polypropylene, nylon-6, polyvinyl chloride, polystyrene). Microplastic-spiked wastewater samples were used to validate the methodology, resulting in a robust protocol which was nonselective and reproducible (the overall success identification rate was 98.33%). The use of FPA-based micro-FT-IR spectroscopy also provides a considerable reduction in analysis time compared with previous methods, since samples that could take several days to be mapped using a single-element detector can now be imaged in less than 9 h (circular filter with a diameter of 47 mm). This method for identifying and quantifying microplastics in wastewater is likely to provide an essential tool for further research into the pathways by which microplastics enter the environment.

  12. Very large scale heterogeneous integration (VLSHI) and wafer-level vacuum packaging for infrared bolometer focal plane arrays

    Science.gov (United States)

    Forsberg, Fredrik; Roxhed, Niclas; Fischer, Andreas C.; Samel, Björn; Ericsson, Per; Hoivik, Nils; Lapadatu, Adriana; Bring, Martin; Kittilsland, Gjermund; Stemme, Göran; Niklaus, Frank

    2013-09-01

    Imaging in the long wavelength infrared (LWIR) range from 8 to 14 μm is an extremely useful tool for non-contact measurement and imaging of temperature in many industrial, automotive and security applications. However, the cost of the infrared (IR) imaging components has to be significantly reduced to make IR imaging a viable technology for many cost-sensitive applications. This paper demonstrates new and improved fabrication and packaging technologies for next-generation IR imaging detectors based on uncooled IR bolometer focal plane arrays. The proposed technologies include very large scale heterogeneous integration for combining high-performance, SiGe quantum-well bolometers with electronic integrated read-out circuits and CMOS compatible wafer-level vacuum packing. The fabrication and characterization of bolometers with a pitch of 25 μm × 25 μm that are arranged on read-out-wafers in arrays with 320 × 240 pixels are presented. The bolometers contain a multi-layer quantum well SiGe thermistor with a temperature coefficient of resistance of -3.0%/K. The proposed CMOS compatible wafer-level vacuum packaging technology uses Cu-Sn solid-liquid interdiffusion (SLID) bonding. The presented technologies are suitable for implementation in cost-efficient fabless business models with the potential to bring about the cost reduction needed to enable low-cost IR imaging products for industrial, security and automotive applications.

  13. Low-power low-noise analog circuits for on-focal-plane signal processing of infrared sensors

    Science.gov (United States)

    Pain, Bedabrata; Mendis, Sunetra K.; Schober, Robert C.; Nixon, Robert H.; Fossum, Eric R.

    1993-10-01

    On-focal-plane signal processing circuits for enhancement of IR imager performance are presented. To enable the detection of high background IR images, an in-pixel current-mode background suppression scheme is presented. The background suppression circuit consists of a current memory placed in the feedback loop of a CTIA and is designed for a thousand-fold suppression of the background flux, thereby easing circuit design constraints, and assuring BLIP operation even with detectors having large response non-uniformities. For improving the performance of low-background IR imagers, an on-chip column-parallel analog-to-digital converter (ADC) is presented. The design of a 10-bit ADC with 50 micrometers pitch and based on sigma-delta ((Sigma) -(Delta) ) modulation is presented. A novel IR imager readout technique featuring photoelectron counting in the unit cell is presented for ultra-low background applications. The output of the unit cell is a digital word corresponding to the incident flux density and the readout is noise free. The design of low-power (noise, high-gain (> 100,000), small real estate (60 micrometers pitch) self-biased CMOS amplifiers required for photon counting are presented.

  14. Synthesis, characterization and frictional wear behavior of ceria hybrid architectures with {111} exposure planes

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Pengfei [School of Mechanical Engineering, University of South China, Hengyang 421001 (China); Chen, Yong, E-mail: chenyongjsnt@163.com [School of Mechanical Engineering, University of South China, Hengyang 421001 (China); Sun, Rong [Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai (Japan); Chen, Yue; Yin, Yaru [School of Mechanical Engineering, University of South China, Hengyang 421001 (China); Wang, Zhongchang, E-mail: zcwang@wpi-aimr.tohoku.ac.jp [Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai (Japan)

    2017-04-15

    Highlights: • A hybrid architecture comprising three types of cerium nanoparticles (nano-octahedron and its’ ramifications) is synthesized. • The exposure planes of the prepared ceria nanoparticles are {111} crystal planes. • The nanoparticles show markedly material remove capacity and inferior polishing quality. - Abstract: A hybrid architecture comprising three types of cerium nanoparticles, nano-octahedron and its ramifications, is synthesized via a facile yet efficient hydrothermal process. Comprehensive transmission electron microscopy analysis identifies the exposure planes of the cube-shaped ceria nanoparticles as {111} crystal planes. As a result of this unique morphology, the nanoparticles are found to show markedly enhanced material removal capacity and inferior polishing quality compared to the sphere-shaped ceria nanoparticles.

  15. Hybrid iterative phase retrieval algorithm based on fusion of intensity information in three defocused planes.

    Science.gov (United States)

    Zeng, Fa; Tan, Qiaofeng; Yan, Yingbai; Jin, Guofan

    2007-10-01

    Study of phase retrieval technology is quite meaningful, for its wide applications related to many domains, such as adaptive optics, detection of laser quality, precise measurement of optical surface, and so on. Here a hybrid iterative phase retrieval algorithm is proposed, based on fusion of the intensity information in three defocused planes. First the conjugate gradient algorithm is adapted to achieve a coarse solution of phase distribution in the input plane; then the iterative angular spectrum method is applied in succession for better retrieval result. This algorithm is still applicable even when the exact shape and size of the aperture in the input plane are unknown. Moreover, this algorithm always exhibits good convergence, i.e., the retrieved results are insensitive to the chosen positions of the three defocused planes and the initial guess of complex amplitude in the input plane, which has been proved by both simulations and further experiments.

  16. Reliable Transport over SpaceWire for James Webb Space Telescope (JWST) Focal Plane Electronics (FPE) Network

    Science.gov (United States)

    Rakow, Glenn; Schnurr, Richard; Dailey, Christopher; Shakoorzadeh, Kamdin

    2003-01-01

    NASA's James Webb Space Telescope (JWST) faces difficult technical and budgetary challenges to overcome before it is scheduled launch in 2010. The Integrated Science Instrument Module (ISIM), shares these challenges. The major challenge addressed in this paper is the data network used to collect, process, compresses and store Infrared data. A total of 114 Mbps of raw information must be collected from 19 sources and delivered to the two redundant data processing units across a twenty meter deployed thermally restricted interface. Further data must be transferred to the solid-state recorder and the spacecraft. The JWST detectors are kept at cryogenic temperatures to obtain the sensitivity necessary to measure faint energy sources. The Focal Plane Electronics (FPE) that sample the detector, generate packets from the samples, and transmit these packets to the processing electronics must dissipate little power in order to help keep the detectors at these cold temperatures. Separating the low powered front-end electronics from the higher-powered processing electronics, and using a simple high-speed protocol to transmit the detector data minimize the power dissipation near the detectors. Low Voltage Differential Signaling (LVDS) drivers were considered an obvious choice for physical layer because of their high speed and low power. The mechanical restriction on the number cables across the thermal interface force the Image packets to be concentrated upon two high-speed links. These links connect the many image packet sources, Focal Plane Electronics (FPE), located near the cryogenic detectors to the processing electronics on the spacecraft structure. From 12 to 10,000 seconds of raw data are processed to make up an image, various algorithms integrate the pixel data Loss of commands to configure the detectors as well as the loss of science data itself may cause inefficiency in the use of the telescope that are unacceptable given the high cost of the observatory. This

  17. Development of the focal plane PNCCD camera system for the X-ray space telescope eROSITA

    International Nuclear Information System (INIS)

    Meidinger, Norbert; Andritschke, Robert; Ebermayer, Stefanie; Elbs, Johannes; Haelker, Olaf; Hartmann, Robert; Herrmann, Sven; Kimmel, Nils; Schaechner, Gabriele; Schopper, Florian; Soltau, Heike; Strueder, Lothar; Weidenspointner, Georg

    2010-01-01

    A so-called PNCCD, a special type of CCD, was developed twenty years ago as focal plane detector for the XMM-Newton X-ray astronomy mission of the European Space Agency ESA. Based on this detector concept and taking into account the experience of almost ten years of operation in space, a new X-ray CCD type was designed by the 'MPI semiconductor laboratory' for an upcoming X-ray space telescope, called eROSITA (extended Roentgen survey with an imaging telescope array). This space telescope will be equipped with seven X-ray mirror systems of Wolter-I type and seven CCD cameras, placed in their foci. The instrumentation permits the exploration of the X-ray universe in the energy band from 0.3 up to 10 keV by spectroscopic measurements with a time resolution of 50 ms for a full image comprising 384x384 pixels. Main scientific goals are an all-sky survey and investigation of the mysterious 'Dark Energy'. The eROSITA space telescope, which is developed under the responsibility of the 'Max-Planck-Institute for extraterrestrial physics', is a scientific payload on the new Russian satellite 'Spectrum-Roentgen-Gamma' (SRG). The mission is already approved by the responsible Russian and German space agencies. After launch in 2012 the destination of the satellite is Lagrange point L2. The planned observational program takes about seven years. We describe the design of the eROSITA camera system and present important test results achieved recently with the eROSITA prototype PNCCD detector. This includes a comparison of the eROSITA detector with the XMM-Newton detector.

  18. Characterization of EASIROC as front-end for the readout of the SiPM at the focal plane of the Cherenkov telescope ASTRI

    International Nuclear Information System (INIS)

    Impiombato, D.; Giarrusso, S.; Mineo, T.; Belluso, M.; Billotta, S.; Bonanno, G.; Catalano, O.; Grillo, A.; La Rosa, G.; Marano, D.; Sottile, G.

    2013-01-01

    The Extended Analogue Silicon Photo-multiplier Integrated Read Out Chip, EASIROC, is a chip proposed as front-end of the camera at the focal plane of the imaging Cherenkov ASTRI SST-2M telescope prototype. This paper presents the results of the measurements performed to characterize EASIROC in order to evaluate its compliance with the ASTRI SST-2M focal plane requirements. In particular, we investigated the trigger time walk and the jitter effects as a function of the pulse amplitude. The EASIROC output signal is found to vary linearly as a function of the input pulse amplitude with very low level of electronic noise and cross-talk (<1%). Our results show that it is suitable as front-end chip for the camera prototype, although, specific modifications are necessary to adopt the device in the final version of the telescope

  19. An efficient and novel computation method for simulating diffraction patterns from large-scale coded apertures on large-scale focal plane arrays

    Science.gov (United States)

    Shrekenhamer, Abraham; Gottesman, Stephen R.

    2012-10-01

    A novel and memory efficient method for computing diffraction patterns produced on large-scale focal planes by largescale Coded Apertures at wavelengths where diffraction effects are significant has been developed and tested. The scheme, readily implementable on portable computers, overcomes the memory limitations of present state-of-the-art simulation codes such as Zemax. The method consists of first calculating a set of reference complex field (amplitude and phase) patterns on the focal plane produced by a single (reference) central hole, extending to twice the focal plane array size, with one such pattern for each Line-of-Sight (LOS) direction and wavelength in the scene, and with the pattern amplitude corresponding to the square-root of the spectral irradiance from each such LOS direction in the scene at selected wavelengths. Next the set of reference patterns is transformed to generate pattern sets for other holes. The transformation consists of a translational pattern shift corresponding to each hole's position offset and an electrical phase shift corresponding to each hole's position offset and incoming radiance's direction and wavelength. The set of complex patterns for each direction and wavelength is then summed coherently and squared for each detector to yield a set of power patterns unique for each direction and wavelength. Finally the set of power patterns is summed to produce the full waveband diffraction pattern from the scene. With this tool researchers can now efficiently simulate diffraction patterns produced from scenes by large-scale Coded Apertures onto large-scale focal plane arrays to support the development and optimization of coded aperture masks and image reconstruction algorithms.

  20. The translated conceptual survey of physics / stablization of the focal plane in two photon excitation fluorescence microscopy

    Science.gov (United States)

    Wada, Asma

    excitation wavelengths in the near infrared (NIR). The (NIR) wavelength regime, 750- 1100nm, penetrates deep (>100 μm) into tissue, and has been used to image to depths of up to 1 mm. Further, the longer excitation wavelengths are less absorbing than the traditional ultraviolet wavelengths used in confocal microscopy, and are consequently less damaging. As a result, (TPEF) is presently the preferred tool for visualizing dynamics by biologists. One important aspect of imaging living systems, however, is that they move! This adds to the challenge of trying to study some particular biological function(s). This thesis begins to address this issue by combining a simple micro controller circuit that can be linked to a remote focusing scheme that will make it possible to lock a focal plane to a specific depth inside a living, moving specimen.

  1. Theoretical investigation of the energy resolution of an ideal hemispherical deflector analyzer and its dependence on the distance from the focal plane

    International Nuclear Information System (INIS)

    Zouros, T.J.M.

    2006-01-01

    In most modern hemispherical deflector analyzers (HDAs) using a position sensitive detector (PSD), due to practical geometrical constraints (fringing field correctors, grids etc.), the PSD cannot always be placed at the optimal position, i.e. the first-order focal plane following 180 o deflection at h=0. Here, the dependence of the exit radial base width Δr πh *, base energy resolution R Bh and line shape L h on the distance h between the focal plane and the detection plane for an ideal HDA (no fringing fields) is investigated theoretically as a function of the maximum injection angle α max- bar * and the diameter of the entry aperture Δr 0 . Both exact numerical results and practical analytic formulas based on Taylor series expansions developed for any HDA show R Bh and L h become increasingly degraded with increasing h from their optimal values at h=0. A detailed comparison of the resolution properties of conventional and biased paracentric HDAs is also presented. Apart from a few marginal improvements of limited utility, overall, the ideal paracentric HDA does not seem to have any distinct practical advantages over the conventional HDA. Resolution improvements recently reported for non-ideal paracentric HDAs must therefore be due to their strong fringing fields and needs to be further investigated. Our ideal HDA results provide a unique standard to evaluate the resolution performance of any HDA under realistic non-zero h-value conditions

  2. The Mechanical Design of a Kinematic Mount for the Mid Infrared Instrument Focal Plane Module on the James Webb Space Telescope

    Science.gov (United States)

    Thelen, Michael P.; Moore, Donald M.

    2009-01-01

    The detector assembly for the Mid Infrared Instrument (MIRI) of the James Webb Space Telescope (JWST) is mechanically supported in the Focal Plane Module (FPM) Assembly with an efficient hexapod design. The kinematic mount design allows for precision adjustment of the detector boresight to assembly alignment fiducials and maintains optical alignment requirements during flight conditions of launch and cryogenic operations below 7 Kelvin. This kinematic mounting technique is able to be implemented in a variety of optical-mechanical designs and is capable of micron level adjustment control and stability over wide dynamic and temperature ranges.

  3. A hybrid active optical system for wave front preservation and variable focal distance

    Energy Technology Data Exchange (ETDEWEB)

    Cocco, Daniele, E-mail: daniele.cocco@elettra.trieste.i [Sincrotrone Trieste ScpA, 34012 Trieste (Italy); Bortoletto, Gianluca; Sergo, Rudi; Sostero, Giovanni; Cudin, Ivan [Sincrotrone Trieste ScpA, 34012 Trieste (Italy)

    2010-05-01

    A new Free Electron Laser (FEL) user facility, named FERMI-Elettra, is under construction at Sincrotrone Trieste (Italy). It is based on a seeded scheme to provide an almost perfect transform limited beam with fully spatial coherence. The wavelength range will be 100-3 nm with fundamental and will go down to 1 nm by using higher harmonics. It will be operative by autumn 2010. The exceptional characteristics of the source must be preserved until the experimental chamber, where a large set of different experiments will be performed. This condition poses very tight requirements to the design of the beamlines and, in particular, to the focusing optics. Here we will present the active optics system developed for Fermi but intended to be used also on the Elettra beamlines. It is based on the adoption of a hybrid active system composed by UHV compatible stepping motors and piezo ceramic actuators. These mirrors are supposed to provide focal distances from 0.8 m to infinity with an angle of incidence up to a few degrees and residual shape errors below 10 or 5 nm (depending on the wavelength). In this way it is possible to work with an almost perfect focused coherent beam as well as with a uniform defocused or unfocused image. The metrology results on the first 400 mm long mirror will be shown and the actuator system described. A strain gauge assembly, calibrated in Elettra by means of a long trace profiler, and controlled by a custom made electronic system developed by us, is used as a direct in situ encoder.

  4. Focal-plane sensing-processing: a power-efficient approach for the implementation of privacy-aware networked visual sensors.

    Science.gov (United States)

    Fernández-Berni, Jorge; Carmona-Galán, Ricardo; del Río, Rocío; Kleihorst, Richard; Philips, Wilfried; Rodríguez-Vázquez, Ángel

    2014-08-19

    The capture, processing and distribution of visual information is one of the major challenges for the paradigm of the Internet of Things. Privacy emerges as a fundamental barrier to overcome. The idea of networked image sensors pervasively collecting data generates social rejection in the face of sensitive information being tampered by hackers or misused by legitimate users. Power consumption also constitutes a crucial aspect. Images contain a massive amount of data to be processed under strict timing requirements, demanding high-performance vision systems. In this paper, we describe a hardware-based strategy to concurrently address these two key issues. By conveying processing capabilities to the focal plane in addition to sensing, we can implement privacy protection measures just at the point where sensitive data are generated. Furthermore, such measures can be tailored for efficiently reducing the computational load of subsequent processing stages. As a proof of concept, a full-custom QVGA vision sensor chip is presented. It incorporates a mixed-signal focal-plane sensing-processing array providing programmable pixelation of multiple image regions in parallel. In addition to this functionality, the sensor exploits reconfigurability to implement other processing primitives, namely block-wise dynamic range adaptation, integral image computation and multi-resolution filtering. The proposed circuitry is also suitable to build a granular space, becoming the raw material for subsequent feature extraction and recognition of categorized objects.

  5. Focal-Plane Sensing-Processing: A Power-Efficient Approach for the Implementation of Privacy-Aware Networked Visual Sensors

    Directory of Open Access Journals (Sweden)

    Jorge Fernández-Berni

    2014-08-01

    Full Text Available The capture, processing and distribution of visual information is one of the major challenges for the paradigm of the Internet of Things. Privacy emerges as a fundamental barrier to overcome. The idea of networked image sensors pervasively collecting data generates social rejection in the face of sensitive information being tampered by hackers or misused by legitimate users. Power consumption also constitutes a crucial aspect. Images contain a massive amount of data to be processed under strict timing requirements, demanding high-performance vision systems. In this paper, we describe a hardware-based strategy to concurrently address these two key issues. By conveying processing capabilities to the focal plane in addition to sensing, we can implement privacy protection measures just at the point where sensitive data are generated. Furthermore, such measures can be tailored for efficiently reducing the computational load of subsequent processing stages. As a proof of concept, a full-custom QVGA vision sensor chip is presented. It incorporates a mixed-signal focal-plane sensing-processing array providing programmable pixelation of multiple image regions in parallel. In addition to this functionality, the sensor exploits reconfigurability to implement other processing primitives, namely block-wise dynamic range adaptation, integral image computation and multi-resolution filtering. The proposed circuitry is also suitable to build a granular space, becoming the raw material for subsequent feature extraction and recognition of categorized objects.

  6. High dynamic range low-noise focal plane readout for VLWIR applications implemented with current mode background subtraction

    Science.gov (United States)

    Yang, Guang; Sun, Chao; Shaw, Timothy; Wrigley, Chris; Peddada, Pavani; Blazejewski, Edward R.; Pain, Bedabrata

    1998-09-01

    Design and operation of a low noise CMOS focal pa;ne readout circuit with ultra-high charge handling capacity is presented. Designed for high-background, VLWIR detector readout, each readout unit cell use an accurate dynamic current memory for automatic subtraction of the dark pedestal in current domain enabling measurement of small signals 85 dB below the dark level. The redout circuit operates with low-power dissipation, high linearity, and is capable of handling pedestal currents up to 300 nA. Measurements indicate an effective charge handling capacity of over 5 X 10(superscript 9) charges/pixel with less than 10(superscript 5) electrons of input referred noise.

  7. Hybrid Single Photon Emission Computed Tomography/Computed Tomography Sulphur Colloid Scintigraphy in Focal Nodular Hyperplasia

    International Nuclear Information System (INIS)

    Bhoil, Amit; Gayana, Shankramurthy; Sood, Ashwani; Bhattacharya, Anish; Mittal, Bhagwant Rai

    2013-01-01

    It is important to differentiate focal nodular hyperplasia (FNH), a benign condition of liver most commonly affecting women, from other neoplasm such as hepatic adenoma and metastasis. The functional reticuloendothelial features of FNH can be demonstrated by scintigraphy. We present a case of breast cancer in whom fluorodeoxyglucose positron emission tomography/computerized tomography (CT) showed a homogenous hyperdense lesion in liver, which on Tc99m sulfur colloid single-photon emission computed tomography/CT was found to have increased focal tracer uptake suggestive of FNH

  8. Classification of focal liver lesions on ultrasound images by extracting hybrid textural features and using an artificial neural network.

    Science.gov (United States)

    Hwang, Yoo Na; Lee, Ju Hwan; Kim, Ga Young; Jiang, Yuan Yuan; Kim, Sung Min

    2015-01-01

    This paper focuses on the improvement of the diagnostic accuracy of focal liver lesions by quantifying the key features of cysts, hemangiomas, and malignant lesions on ultrasound images. The focal liver lesions were divided into 29 cysts, 37 hemangiomas, and 33 malignancies. A total of 42 hybrid textural features that composed of 5 first order statistics, 18 gray level co-occurrence matrices, 18 Law's, and echogenicity were extracted. A total of 29 key features that were selected by principal component analysis were used as a set of inputs for a feed-forward neural network. For each lesion, the performance of the diagnosis was evaluated by using the positive predictive value, negative predictive value, sensitivity, specificity, and accuracy. The results of the experiment indicate that the proposed method exhibits great performance, a high diagnosis accuracy of over 96% among all focal liver lesion groups (cyst vs. hemangioma, cyst vs. malignant, and hemangioma vs. malignant) on ultrasound images. The accuracy was slightly increased when echogenicity was included in the optimal feature set. These results indicate that it is possible for the proposed method to be applied clinically.

  9. Controlling dental enamel-cavity ablation depth with optimized stepping parameters along the focal plane normal using a three axis, numerically controlled picosecond laser.

    Science.gov (United States)

    Yuan, Fusong; Lv, Peijun; Wang, Dangxiao; Wang, Lei; Sun, Yuchun; Wang, Yong

    2015-02-01

    The purpose of this study was to establish a depth-control method in enamel-cavity ablation by optimizing the timing of the focal-plane-normal stepping and the single-step size of a three axis, numerically controlled picosecond laser. Although it has been proposed that picosecond lasers may be used to ablate dental hard tissue, the viability of such a depth-control method in enamel-cavity ablation remains uncertain. Forty-two enamel slices with approximately level surfaces were prepared and subjected to two-dimensional ablation by a picosecond laser. The additive-pulse layer, n, was set to 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70. A three-dimensional microscope was then used to measure the ablation depth, d, to obtain a quantitative function relating n and d. Six enamel slices were then subjected to three dimensional ablation to produce 10 cavities, respectively, with additive-pulse layer and single-step size set to corresponding values. The difference between the theoretical and measured values was calculated for both the cavity depth and the ablation depth of a single step. These were used to determine minimum-difference values for both the additive-pulse layer (n) and single-step size (d). When the additive-pulse layer and the single-step size were set 5 and 45, respectively, the depth error had a minimum of 2.25 μm, and 450 μm deep enamel cavities were produced. When performing three-dimensional ablating of enamel with a picosecond laser, adjusting the timing of the focal-plane-normal stepping and the single-step size allows for the control of ablation-depth error to the order of micrometers.

  10. Challenges, constraints, and results of lens design for 17 micron-bolometer focal plane arrays in 8-12 micron waveband

    Science.gov (United States)

    Schuster, Norbert; Franks, John

    2011-06-01

    In the 8-12 micron waveband Focal Plane Arrays (FPA) are available with a 17 micron pixel pitch in different arrays sizes (e.g. 512 x 480 pixels and 320 x 240 pixels) and with excellent electrical properties. Many applications become possible using this new type of IR-detector which will become the future standard in uncooled technology. Lenses with an f-number faster than f/1.5 minimize the diffraction impact on the spatial resolution and guarantee a high thermal resolution for uncooled cameras. Both effects will be quantified. The distinction between Traditional f-number (TF) and Radiometric f-number (RF) is discussed. Lenses with different focal lengths are required for applications in a variety of markets. They are classified by their Horizontal field of view (HFOV). Respecting the requirements for high volume markets, several two lens solutions will be discussed. A commonly accepted parameter of spatial resolution is the Modulation Transfer Function (MTF)-value at the Nyquist frequency of the detector (here 30cy/mm). This parameter of resolution will be presented versus field of view. Wide Angle and Super Wide Angle lenses are susceptible to low relative illumination in the corner of the detector. Measures to reduce this drop to an acceptable value are presented.

  11. A Novel Shape-Free Plane Quadratic Polygonal Hybrid Stress-Function Element

    Directory of Open Access Journals (Sweden)

    Pei-Lei Zhou

    2015-01-01

    Full Text Available A novel plane quadratic shape-free hybrid stress-function (HS-F polygonal element is developed by employing the principle of minimum complementary energy and the fundamental analytical solutions of the Airy stress function. Without construction of displacement interpolation function, the formulations of the new model are much simpler than those of the displacement-based polygonal elements and can be degenerated into triangular or quadrilateral elements directly. In particular, it is quite insensitive to various mesh distortions and even can keep precision when element shape is concave. Furthermore, the element does not show any spurious zero energy modes. Numerical examples show the excellent performance of the new element, denoted by HSF-AP-19β, in both displacement and stress solutions.

  12. Initial experience in hybrid PET-MRI for evaluation of refractory focal onset epilepsy.

    Science.gov (United States)

    Shin, Hae W; Jewells, Valerie; Sheikh, Arif; Zhang, Jingwen; Zhu, Hongtu; An, Hongyu; Gao, Wei; Shen, Dinggang; Hadar, Eldad; Lin, Weili

    2015-09-01

    We aim to evaluate the utility/improved accuracy of hybrid PET/MR compared to current practice separate 3T MRI and PET-CT imaging for localization of seizure foci. In a pilot study, twenty-nine patients undergoing epilepsy surgery evaluation were imaged using PET/MR. This subject group had 29 previous clinical 3T MRI as well as 12 PET-CT studies. Prior clinical PET and MR images were read sequentially while the hybrid PET/MR was concurrently read. The median interval between hybrid PET/MR and prior imaging studies was 5 months (range 1-77 months). In 24 patients, there was no change in the read between the clinical exams and hybrid PET/MR while new anatomical or functional lesions were identified by hybrid PET/MR in 5 patients without significant clinical change. Four new anatomical MR lesions were seen with concordant PET findings. The remaining patient revealed a new abnormal PET lesion without an MR abnormality. All new PET/MR lesions were clinically significant with concordant EEG and/or SPECT results as potential epileptic foci. Our initial hybrid PET-MRI experience increased diagnostic yields for detection of potential epileptic lesions. This may be due to the unique advantage of improved co-registration and simultaneous review of both structural and functional data. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  13. Reconstruction of in-plane strain maps using hybrid dense sensor network composed of sensing skin

    International Nuclear Information System (INIS)

    Downey, Austin; Laflamme, Simon; Ubertini, Filippo

    2016-01-01

    The authors have recently developed a soft-elastomeric capacitive (SEC)-based thin film sensor for monitoring strain on mesosurfaces. Arranged in a network configuration, the sensing system is analogous to a biological skin, where local strain can be monitored over a global area. Under plane stress conditions, the sensor output contains the additive measurement of the two principal strain components over the monitored surface. In applications where the evaluation of strain maps is useful, in structural health monitoring for instance, such signal must be decomposed into linear strain components along orthogonal directions. Previous work has led to an algorithm that enabled such decomposition by leveraging a dense sensor network configuration with the addition of assumed boundary conditions. Here, we significantly improve the algorithm’s accuracy by leveraging mature off-the-shelf solutions to create a hybrid dense sensor network (HDSN) to improve on the boundary condition assumptions. The system’s boundary conditions are enforced using unidirectional RSGs and assumed virtual sensors. Results from an extensive experimental investigation demonstrate the good performance of the proposed algorithm and its robustness with respect to sensors’ layout. Overall, the proposed algorithm is seen to effectively leverage the advantages of a hybrid dense network for application of the thin film sensor to reconstruct surface strain fields over large surfaces. (paper)

  14. R and D in photosensors and data acquisition systems for a new generation of Cosmic Ray Cherenkov and Fluorescence Imaging focal planes

    International Nuclear Information System (INIS)

    Assis, Pedro; Brogueira, Pedro; Catalano, Osvaldo; Ferreira, Miguel; Lorenz, Eckart; Mendes, Luís; Pimenta, Mário; Rodrigues, Pedro; Schweizer, Thomas

    2012-01-01

    In this work we present the design, first prototypes and experimental R and D activities on the development of novel imaging cameras for Imaging Atmospheric Cherenkov and Fluorescence Telescopes. The baseline solution for the focal plane is based on a photosensor architecture instrumented with Silicon Photomultipliers (SiPMs). To decrease the trigger threshold and improve the signal-to-noise ratio for low-energy events, the Photon Counting technique is used. For very bright events the conventional Charge Integration approach is retained. The large number of channels requires a compact and modular design with minimal cabling and distance between the photosensors and the frontend. Other design requirements are an efficient light concentration system treated with an anti-reflective coating, a liquid cooling system able to keep the SiPMs at a temperature of −20°C to −10°C, a low-power frontend electronics down to 1 kW/m 2 and an easy field maintenance, high reliability data acquisition and trigger system. In the baseline design, the data acquisition system is partitioned in on-board frontend and off-detector high-level trigger electronics. Extensive use of mixed-signal ASICs and low-power FPGAs for early data reduction (Level 1 trigger), compatible with a liquid cooling sub-system for temperature control is adopted. The off-detector data acquisition and higher trigger (Level 2 and Level 3) architecture is based on the VME64X standard. The boards are connected by multi-Gbps optical links to the focal plane camera. Trigger primitives are sent asynchronously to the trigger boards via data links running at their own clocks. Data and slow-control data streams are also sent over the same links with the parallel VME64X backplane kept for trigger board configuration, slow-control and final data readout. Each 8-slot 6U crate can process up to about 3.6×10 4 SiPM channels.

  15. R and D in photosensors and data acquisition systems for a new generation of Cosmic Ray Cherenkov and Fluorescence Imaging focal planes

    Energy Technology Data Exchange (ETDEWEB)

    Assis, Pedro [LIP, Avenida Elias Garcia 14-1, 1000-149 Lisboa (Portugal); Brogueira, Pedro [LIP, Avenida Elias Garcia 14-1, 1000-149 Lisboa (Portugal); IST, Avenida Rovisco Pais, 1049-001 Lisboa (Portugal); Catalano, Osvaldo [IASF-Palermo, 1, Via Ugo La Malfa 153, 90146 Palermo (Italy); Ferreira, Miguel [LIP, Avenida Elias Garcia 14-1, 1000-149 Lisboa (Portugal); Lorenz, Eckart [MPI, Max-Planck-Institute for Physics, D-80805 Muenchen (Germany); Mendes, Luis [LIP, Avenida Elias Garcia 14-1, 1000-149 Lisboa (Portugal); Pimenta, Mario [LIP, Avenida Elias Garcia 14-1, 1000-149 Lisboa (Portugal); IST, Avenida Rovisco Pais, 1049-001 Lisboa (Portugal); Rodrigues, Pedro, E-mail: psilva@lip.pt [LIP, Avenida Elias Garcia 14-1, 1000-149 Lisboa (Portugal); Schweizer, Thomas [LIP, Avenida Elias Garcia 14-1, 1000-149 Lisboa (Portugal); MPI, Max-Planck-Institute for Physics, D-80805 Muenchen (Germany)

    2012-12-11

    In this work we present the design, first prototypes and experimental R and D activities on the development of novel imaging cameras for Imaging Atmospheric Cherenkov and Fluorescence Telescopes. The baseline solution for the focal plane is based on a photosensor architecture instrumented with Silicon Photomultipliers (SiPMs). To decrease the trigger threshold and improve the signal-to-noise ratio for low-energy events, the Photon Counting technique is used. For very bright events the conventional Charge Integration approach is retained. The large number of channels requires a compact and modular design with minimal cabling and distance between the photosensors and the frontend. Other design requirements are an efficient light concentration system treated with an anti-reflective coating, a liquid cooling system able to keep the SiPMs at a temperature of -20 Degree-Sign C to -10 Degree-Sign C, a low-power frontend electronics down to 1 kW/m{sup 2} and an easy field maintenance, high reliability data acquisition and trigger system. In the baseline design, the data acquisition system is partitioned in on-board frontend and off-detector high-level trigger electronics. Extensive use of mixed-signal ASICs and low-power FPGAs for early data reduction (Level 1 trigger), compatible with a liquid cooling sub-system for temperature control is adopted. The off-detector data acquisition and higher trigger (Level 2 and Level 3) architecture is based on the VME64X standard. The boards are connected by multi-Gbps optical links to the focal plane camera. Trigger primitives are sent asynchronously to the trigger boards via data links running at their own clocks. Data and slow-control data streams are also sent over the same links with the parallel VME64X backplane kept for trigger board configuration, slow-control and final data readout. Each 8-slot 6U crate can process up to about 3.6 Multiplication-Sign 10{sup 4} SiPM channels.

  16. An inverter-based capacitive trans-impedance amplifier readout with offset cancellation and temporal noise reduction for IR focal plane array

    Science.gov (United States)

    Chen, Hsin-Han; Hsieh, Chih-Cheng

    2013-09-01

    This paper presents a readout integrated circuit (ROIC) with inverter-based capacitive trans-impedance amplifier (CTIA) and pseudo-multiple sampling technique for infrared focal plane array (IRFPA). The proposed inverter-based CTIA with a coupling capacitor [1], executing auto-zeroing technique to cancel out the varied offset voltage from process variation, is used to substitute differential amplifier in conventional CTIA. The tunable detector bias is applied from a global external bias before exposure. This scheme not only retains stable detector bias voltage and signal injection efficiency, but also reduces the pixel area as well. Pseudo-multiple sampling technique [2] is adopted to reduce the temporal noise of readout circuit. The noise reduction performance is comparable to the conventional multiple sampling operation without need of longer readout time proportional to the number of samples. A CMOS image sensor chip with 55×65 pixel array has been fabricated in 0.18um CMOS technology. It achieves a 12um×12um pixel size, a frame rate of 72 fps, a power-per-pixel of 0.66uW/pixel, and a readout temporal noise of 1.06mVrms (16 times of pseudo-multiple sampling), respectively.

  17. Therapeutic potential of the novel hybrid molecule JM-20 against focal cortical ischemia in rats

    Directory of Open Access Journals (Sweden)

    Yanier Núñez Figueredo

    2016-08-01

    Full Text Available Context: Despite the great mortality and morbidity of stroke, treatment options remain limited. We previously showed that JM-20, a novel synthetic molecule, possessed a strong neuroprotective effect in rats subjected to transient middle cerebral artery occlusion. However, to verify the robustness of the pre-clinical neuroprotective effects of JM-20 to get good prognosis in the translation to the clinic, it is necessary to use other experimental models of brain ischemia. Aims: To evaluate the neuroprotective effects of JM-20 following the onset of permanent focal cerebral ischemia induced in rats by thermocoagulation of blood into pial blood vessels of cerebral cortices. Methods: Ischemic lesion was induced by thermocoagulation of blood into pial blood vessels of primary motor and somatosensory cortices. Behavioral performance was evaluated by the cylinder testing for a period of 2, 3 and 7 days after surgery, and was followed by histopathological study in brain cortex stained with hematoxylin- eosin. Results: Ischemic injury resulted in impaired function of the forelimb evidenced by high asymmetry punctuation, and caused histopathological alterations indicative of tissue damage at cerebral cortex. JM-20 treatment (4 and 8 mg/kg significantly decreased asymmetry scores and histological alterations with a marked preservation of cortical neurons. Conclusions: The effects of permanent brain ischemia were strongly attenuated by JM-20 administration, which expands and improves the current preclinical data of JM-20 as neuroprotector against cerebral ischemia, and strongly support the examination of its translation to the clinic to treat acute ischemic stroke.

  18. Synergy of exchange bias with superconductivity in ferromagnetic-superconducting layered hybrids: the influence of in-plane and out-of-plane magnetic order on superconductivity

    International Nuclear Information System (INIS)

    Stamopoulos, D; Manios, E; Pissas, M

    2007-01-01

    It is generally believed that superconductivity and magnetism are two antagonistic long-range phenomena. However, as was preliminarily highlighted in Stamopoulos et al (2007 Phys. Rev. B 75 014501), and extensively studied in this work, under specific circumstances these phenomena instead of being detrimental to each other may even become cooperative so that their synergy may promote the superconducting properties of a hybrid structure. Here, we have studied systematically the magnetic and transport behavior of such exchange biased hybrids that are comprised of ferromagnetic (FM) Ni 80 Fe 20 and low-T c superconducting (SC) Nb for the case where the magnetic field is applied parallel to the specimens. Two structures have been studied: FM-SC-FM trilayers (TLs) and FM-SC bilayers (BLs). Detailed magnetization data on the longitudinal and transverse magnetic components are presented for both the normal and superconducting states. These data are compared to systematic transport measurements including I-V characteristics. The comparison of the exchange biased BLs and TLs that are studied here with the plain ones studied in Stamopoulos et al (2007 Phys. Rev. B 75 184504) enable us to reveal an underlying parameter that may falsify the interpretation of the transport properties of relevant FM-SC-FM TLs and FM-SC BLs investigated in the recent literature: the underlying mechanism motivating the extreme magnetoresistance peaks in the TLs relates to the suppression of superconductivity mainly due to the magnetic coupling of the two FM layers as the out-of-plane rotation of their magnetizations takes place across the coercive field where stray fields emerge in their whole surface owing to the multidomain magnetic state that they acquire. The relative in-plane magnetization configuration of the outer FM layers exerts a secondary contribution on the SC interlayer. Since the exchange bias directly controls the in-plane magnetic order it also controls the out-of-plane rotation of

  19. Managing focal fields of vector beams with multiple polarization singularities.

    Science.gov (United States)

    Han, Lei; Liu, Sheng; Li, Peng; Zhang, Yi; Cheng, Huachao; Gan, Xuetao; Zhao, Jianlin

    2016-11-10

    We explore the tight focusing behavior of vector beams with multiple polarization singularities, and analyze the influences of the number, position, and topological charge of the singularities on the focal fields. It is found that the ellipticity of the local polarization states at the focal plane could be determined by the spatial distribution of the polarization singularities of the vector beam. When the spatial location and topological charge of singularities have even-fold rotation symmetry, the transverse fields at the focal plane are locally linearly polarized. Otherwise, the polarization state becomes a locally hybrid one. By appropriately arranging the distribution of the polarization singularities in the vector beam, the polarization distributions of the focal fields could be altered while the intensity maintains unchanged.

  20. Radiometric characterization of type-II InAs/GaSb superlattice (t2sl) midwave infrared photodetectors and focal plane arrays

    Science.gov (United States)

    Nghiem, Jean; Giard, E.; Delmas, M.; Rodriguez, J. B.; Christol, P.; Caes, M.; Martijn, H.; Costard, E.; Ribet-Mohamed, I.

    2017-09-01

    In recent years, Type-II InAs/GaSb superlattice (T2SL) has emerged as a new material technology suitable for high performance infrared (IR) detectors operating from Near InfraRed (NIR, 2-3μm) to Very Long Wavelength InfraRed (LWIR, λ > 15μm) wavelength domains. To compare their performances with well-established IR technologies such as MCT, InSb or QWIP cooled detectors, specific electrical and radiometric characterizations are needed: dark current, spectral response, quantum efficiency, temporal and spatial noises, stability… In this paper, we first present quantum efficiency measurements performed on T2SL MWIR (3-5μm) photodiodes and on one focal plane array (320x256 pixels with 30μm pitch, realized in the scope of a french collaboration ). Different T2SL structures (InAs-rich versus GaSb-rich) with the same cutoff wavelength (λc= 5μm at 80K) were studied. Results are analysed in term of carrier diffusion length in order to define the optimum thickness and type of doping of the absorbing zone. We then focus on the stability over time of a commercial T2SL FPA (320x256 pixels with 30μm pitch), measuring the commonly used residual fixed pattern noise (RFPN) figure of merit. Results are excellent, with a very stable behaviour over more than 3 weeks, and less than 10 flickering pixels, possibly giving access to long-term stability of IR absolute calibration.

  1. Identification of microplastic in effluents of waste water treatment plants using focal plane array-based micro-Fourier-transform infrared imaging.

    Science.gov (United States)

    Mintenig, S M; Int-Veen, I; Löder, M G J; Primpke, S; Gerdts, G

    2017-01-01

    The global presence of microplastic (MP) in aquatic ecosystems has been shown by various studies. However, neither MP concentrations nor their sources or sinks are completely known. Waste water treatment plants (WWTPs) are considered as significant point sources discharging MP to the environment. This study investigated MP in the effluents of 12 WWTPs in Lower Saxony, Germany. Samples were purified by a plastic-preserving enzymatic-oxidative procedure and subsequent density separation using a zinc chloride solution. For analysis, attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FT-IR) and focal plane array (FPA)-based transmission micro-FT-IR imaging were applied. This allowed the identification of polymers of all MP down to a size of 20 μm. In all effluents MP was found with quantities ranging from 0 to 5 × 10 1  m -3  MP > 500 μm and 1 × 10 1 to 9 × 10 3  m -3  MP < 500 μm. By far, polyethylene was the most frequent polymer type in both size classes. Quantities of synthetic fibres ranged from 9 × 10 1 to 1 × 10 3  m -3 and were predominantly made of polyester. Considering the annual effluxes of tested WWTPs, total discharges of 9 × 10 7 to 4 × 10 9  MP particles and fibres per WWTP could be expected. Interestingly, one tertiary WWTP had an additionally installed post-filtration that reduced the total MP discharge by 97%. Furthermore, the sewage sludge of six WWTPs was examined and the existence of MP, predominantly polyethylene, revealed. Our findings suggest that WWTPs could be a sink but also a source of MP and thus can be considered to play an important role for environmental MP pollution. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Few-layered MnO2/SWCNT hybrid in-plane supercapacitor with high energy density

    Science.gov (United States)

    Dutta, Shibsankar; Pal, Shreyasi; De, Sukanta

    2018-05-01

    In this present work we have synthesized few layered MnO2 nanosheets by mixed solvent exfoliation process for the application as electrode material of in-plane supercapacitor. The Structure and surface morphology of the as prepared samples are characterized by Raman, Transmission electron microscopy and Scanning electron microscopy. The patterns of the hybrids were directly fabricated by (50: 50 wt %) mixture of MnO2 and SWCNT dispersions with the help of a customized mask, and directly transferred onto a flexible PET substrate. Remarkably, the prepared in-plane supercapacitors deliver high energy density of 2.62mWh/cm2. Furthermore, our supercapacitors shows exceptional flexibility and stable performance under bending conditions

  3. Analysis of control and management plane for hybrid fiber radio architectures

    DEFF Research Database (Denmark)

    Kardaras, Georgios; Pham, Tien Thang; Soler, José

    2010-01-01

    This paper presents the existing Radio over Fiber (RoF) architectures and focuses on the control and management plane of the Remote Antenna Unit (RAU). Broadband wireless standards, such as WiMAX and LTE, incorporate optical technologies following the distributed base station concept. The control...... and management of the RAU becomes a critical task, since it can facilitate allocation of resources, configuration and upgrade of the remote unit and constant monitoring of its performance. In the case of baseband over fiber, two protocols (OBSAI and CPRI) introduce a well-defined control and management plane....... In the case of intermediate/radio frequency over fiber, this paper presents a simple approach, which can provide configurability and real-time monitoring of the RAU over the same optical link. This is realized by multiplexing high frequency user data with baseband frequency control data at the Central Office...

  4. Scalable imaging of scattering organisms with hybrid selective plane illumination microscopy and optoacoustic tomography

    OpenAIRE

    Lin, Hsiao Chun Amy

    2017-01-01

    Biomedical imaging plays a key role in the advancement of medical research. While high-resolution microscopy enables the harvest of molecular and cellular information, a holistic picture on organ level can only be provided by means of macroscopic imaging. Wedged in between Micro-macro, the mesoscopic regime offers important bridging of the information transfer. The focus of the research presented in this thesis centers around the application of selective plane illumination microscopy (SPIM) a...

  5. Focal myositis

    International Nuclear Information System (INIS)

    Kransdorf, M.J.; Temple, H.T.; Sweet, D.E.

    1998-01-01

    Focal myositis is a pseudotumor of soft tissue that typically occurs in the deep soft tissue of the extremities, and is a relatively rare lesion. There is a wide clinical spectrum, with approximately one-third of patients with focal myositis subsequently developing polymyositis, and clinical symptoms of generalized weakness, fever, myalgia, and weight loss, with elevation of creatine phosphokinase. We report the case of a patient with focal myositis who subsequently developed myositis ossificans-like features. (orig.)

  6. Development of a focal-plane drift chamber for low-energetic pions and experimental determination of an inverse transfer matrix for the short-orbit spectrometer

    International Nuclear Information System (INIS)

    Ding, M.

    2004-10-01

    The three-spectrometer facility at the Mainz microtron MAMI was supplemented by an additional spectrometer, which is characterized by its short path-length and therefore is called Short Orbit Spectrometer (SOS). At nominal distance from target to SOS (66 cm) the particles to be detected cover a mean path-length between reaction point and detector of 165 cm. Thus for pion electroproduction close to threshold in comparison to the big spectrometers the surviving probability of charged pions with momentum 100 MeV/c raises from 15% to 73%. Consequently the systematic error (''myon contamination''), as for the proposed measurement of the weak form-factors G A (Q 2 ) and G P (Q 2 ), reduces significantly. The main subject of this thesis is the drift chamber for the SOS. Its small relative thickness (0.03% X 0 ), reducing multiple scattering, is optimized with regard to detecting low-energy pions. Due to the innovative character of the driftchamber geometry a dedicated software for track-reconstruction, efficiency-determination etc. had to be developed. A comfortable feature for calibrating the drift path-drift time-relation, represented by cubic splines, was implemented. The resolution of the track detector in the dispersive plane is 76 μaem for the spatial and 0.23 for the angular coordinate (most probable error) and, correspondingly, 110 μm and 0.29 in the non-dispersive plane. For backtracing the reaction quantities from the detector coordinates the inverse transfer-matrix of the spectrometer was determined. For this purpose electrons were scattered quasi-elastically from protons inside the 12 C-nucleus, thus defining the starting angles of the electrons by holes of a sieve collimator. The resulting experimental values for the angular resolution at the target amount to σ φ =1.3 mrad and σ θ =10.6 mrad resp. The momentum calibration of the SOS only can be achieved by quasi-elastic scattering (two-arm experiment). For this reason the contribution of the proton

  7. Focal myositis

    International Nuclear Information System (INIS)

    Galloway, H.R.; Dahlstrom, J.E.; Bennett, G.M.

    2001-01-01

    Focal myositis is a rare, benign focal inflammation of muscle. The lesion often presents as a mass that may be mistaken for a soft tissue sarcoma. This report describes the MRI and histopathological features of a case and illustrates how the diagnosis may be suspected on the basis of the MR findings. Copyright (2001) Blackwell Science Pty Ltd

  8. Focal myositis

    Energy Technology Data Exchange (ETDEWEB)

    Kransdorf, M.J. [Saint Mary`s Hospital, Richmond, VA (United States). Dept. of Radiol.]|[Department of Radiologic Pathology, Armed Forces Institute of Pathology, Washington, DC (United States); Temple, H.T. [Department of Orthopedic Surgery, University of Virginia Health Sciences Center, Charlottesville, Virginia (United States)]|[Department of Orthopedic Pathology, Armed Forces Institute of Pathology, Washington, DC (United States); Sweet, D.E. [Department of Orthopedic Pathology, Armed Forces Institute of Pathology, Washington, DC (United States)

    1998-05-01

    Focal myositis is a pseudotumor of soft tissue that typically occurs in the deep soft tissue of the extremities, and is a relatively rare lesion. There is a wide clinical spectrum, with approximately one-third of patients with focal myositis subsequently developing polymyositis, and clinical symptoms of generalized weakness, fever, myalgia, and weight loss, with elevation of creatine phosphokinase. We report the case of a patient with focal myositis who subsequently developed myositis ossificans-like features. (orig.) With 3 figs., 25 refs.

  9. Island shape, size and interface dependency on electronic and magnetic properties of graphene hexagonal-boron nitride (h-BN) in-plane hybrids

    Science.gov (United States)

    Akman, Nurten; Özdoğan, Cem

    2018-04-01

    We systematically investigate the energetics of ion implantation, stability, electronic, and magnetic properties of graphene/hexagonal boron nitrate (h-BN) in-plane hybrids through first principle calculations. We consider hexagonal and triangular islands in supercells of graphene and h-BN layouts. In the case of triangular islands, both phases mix with each other by either solely Csbnd N or Csbnd B bonds. We also patterned triangles with predominating Csbnd N or Csbnd B bonds at their interfaces. The energetics of island implantation is discussed in detail. Formation energies point out that the island implantation could be even exothermic for all hybrids studied in this work. Effects of size and shape of the island, and dominating bonding sort at the island-layout interfaces on the stability, band gap, and magnetic properties of hybrids are studied particularly. The hybrids become more stable with increasing island size. Regardless of the layout, hybrids with hexagonal islands are all non-magnetic and semiconducting. One can thus open a band gap in the semimetallic graphene by mixing it with the h-BN phase. In general, hybrids containing graphene triangles show metallic property and exhibit considerable amount of magnetic moments for possible localized spin utilizations. Total magnetic moment of hybrids with both graphene and h-BN layouts increases with growing triangle island as well. The spin densities of magnetic hybrids are derived from interfaces of the islands and diminish towards their center. We suggest that the increase in stability and magnetic moment depend on the number of atoms at the interfaces rather than the island size.

  10. Focal plane arrays for THz imaging

    NARCIS (Netherlands)

    Iacono, A.; Bencivenni, C.; Freni, A.; Neto, A.; Gerini, G.

    2012-01-01

    The growing attention for Terahertz technology finds support in the high number of applications which will benefit by its use. In the space science sector, the investigation of the THz frequency range will improve the knowledge of the universe, giving a clearer view on its origin and its evolution.

  11. Focal Plane Alignment Utilizing Optical CMM

    Science.gov (United States)

    Liebe, Carl Christian; Meras, Patrick L.; Clark, Gerald J.; Sedaka, Jack J.; Kaluzny, Joel V.; Hirsch, Brian; Decker, Todd A.; Scholtz, Christopher R.

    2012-01-01

    In many applications, an optical detector has to be located relative to mechanical reference points. One solution is to specify stringent requirements on (1) mounting the optical detector relative to the chip carrier, (2) soldering the chip carrier onto the printed circuit board (PCB), and (3) installing the PCB to the mechanical structure of the subsystem. Figure 1 shows a sketch of an optical detector mounted relative to mechanical reference with high positional accuracy. The optical detector is typically a fragile wafer that cannot be physically touched by any measurement tool. An optical coordinate measuring machine (CMM) can be used to position optical detectors relative to mechanical reference points. This approach will eliminate all requirements on positional tolerances. The only requirement is that the PCB is manufactured with oversized holes. An exaggerated sketch of this situation is shown in Figure 2. The sketch shows very loose tolerances on mounting the optical detector in the chip carrier, loose tolerance on soldering the chip carrier to the PCB, and finally large tolerance on where the mounting screws are located. The PCB is held with large screws and oversized holes. The PCB is mounted loosely so it can move freely around. The optical CMM measures the mechanical reference points. Based on these measurements, the required positions of the optical detector corners can be calculated. The optical CMM is commanded to go to the position where one detector corner is supposed to be. This is indicated with the cross-hairs in Figure 2(a). This figure is representative of the image of the optical CMM monitor. Using a suitable tapping tool, the PCB is manually tapped around until the corner of the optical detector is at the crosshairs of the optical CMM. The CMM is commanded to another corner, and the process is repeated a number of times until all corners of the optical detector are within a distance of 10 to 30 microns of the required position. The situation is sketched in Figure 2(b) (the figure also shows the tapping tool and where to tap). At this point the fasteners for the PCB are torqued slightly so the PCB can still move. The PCB location is adjusted again with the tapping tool. This process is repeated 3 to 4 times until the final torque is achieved. The oversized mounting holes are then filled with a liquid bonding agent to secure the board in position (not shown in the sketch). A 10- to 30-micron mounting accuracy has been achieved utilizing this method..

  12. Synchrotron- and focal plane array-based Fourier-transform infrared spectroscopy differentiates the basalis and functionalis epithelial endometrial regions and identifies putative stem cell regions of human endometrial glands.

    Science.gov (United States)

    Theophilou, Georgios; Morais, Camilo L M; Halliwell, Diane E; Lima, Kássio M G; Drury, Josephine; Martin-Hirsch, Pierre L; Stringfellow, Helen F; Hapangama, Dharani K; Martin, Francis L

    2018-05-09

    The cyclical process of regeneration of the endometrium suggests that it may contain a cell population that can provide daughter cells with high proliferative potential. These cell lineages are clinically significant as they may represent clonogenic cells that may also be involved in tumourigenesis as well as endometriotic lesion development. To determine whether the putative stem cell location within human uterine tissue can be derived using vibrational spectroscopy techniques, normal endometrial tissue was interrogated by two spectroscopic techniques. Paraffin-embedded uterine tissues containing endometrial glands were sectioned to 10-μm-thick parallel tissue sections and were floated onto BaF 2 slides for synchrotron radiation-based Fourier-transform infrared (SR-FTIR) microspectroscopy and globar focal plane array-based FTIR spectroscopy. Different spectral characteristics were identified depending on the location of the glands examined. The resulting infrared spectra were subjected to multivariate analysis to determine associated biophysical differences along the length of longitudinal and crosscut gland sections. Comparison of the epithelial cellular layer of transverse gland sections revealed alterations indicating the presence of putative transient-amplifying-like cells in the basalis and mitotic cells in the functionalis. SR-FTIR microspectroscopy of the base of the endometrial glands identified the location where putative stem cells may reside at the same time pointing towards ν s PO 2 - in DNA and RNA, nucleic acids and amide I and II vibrations as major discriminating factors. This study supports the view that vibration spectroscopy technologies are a powerful adjunct to our understanding of the stem cell biology of endometrial tissue. Graphical abstract ᅟ.

  13. Nearaffine planes

    NARCIS (Netherlands)

    Wilbrink, H.A.

    1982-01-01

    In this paper we develop a theory for nearaffine planes analogous to the theory of ordinary affine translation planes. In a subsequent paper we shall use this theory to give a characterization of a certain class of Minkowski planes.

  14. Focal pancreatic enlargement: differentiation between pancreatic adenocarcinoma and focal pancreatitis on CT and ERCP

    International Nuclear Information System (INIS)

    Kim, Eun Kyung; Kim, Ki Whang; Lee, Jong Tae; Kim, Hee Soo; Yoo, Hyung Sik; Yu, Jeong Sik; Yoon, Sang Wook

    1995-01-01

    To differentiate the pancreatic adenocarcinoma from focal pancreatitis on CT and ERCP in cases of focal pancreatic enlargement. We analysed CT findings of 66 patients of pancreatic adenocarcinoma (n = 45) or focal pancreatitis (n = 21) with respect to size, density, calcification, pancreatic or biliary duct dilatation, fat plane obliteration around the vessels, direction of retroperitoneal extension, lymphadenopathy, pseudocyst formation and atrophy of pancreas. ERCP available in 48 patients were analysed in respect to morphologic appearance of CBD and pancreatic duct, and distance between the two ducts. The patients in focal pancreatitis were younger with more common history of alcohol drinking. There was no statistical difference in calcifications of the mass (18% in the adenocarcinoma, 33% in the focal pancreatitis), but a tendency of denser, larger number of calcifications was noted in focal pancreatitis. The finding of fat plane obliteration around the vessels were more common in pancreatic adenocarcinoma, and fascial thickenings were more prominent in focal pancreatitis, although not statistically significant. On ERCP, there were no differential points of CBD, pancreatic duct morphology, but distance between the two ducts at the lesion center was more wider in focal pancreatitis. Differentiating focal pancreatitis from pancreatic adenocarcinoma is difficult. However, we should consider the possibility of focal pancreatitis in cases of patients with young age, having alcoholic history in association with CT findings of large numbers of and dense calcifications, and ERCP findings of prominent separation of two duct at the lesion center

  15. La détection infrarouge avec les plans focaux non refroidis : état de l'artUncooled focal plane infrared detectors: the state of the art

    Science.gov (United States)

    Tissot, Jean-Luc

    2003-12-01

    The emergence of uncooled detectors has opened new opportunities for IR detection for both military and commercial applications. Development of such devices involves a lot of trade-offs between the different parameters that define the technological stack. These trade-offs explain the number of different architectures that are under worldwide development. The key factor is to find a high sensitivity and low noise thermometer material compatible with silicon technology in order to achieve high thermal isolation in the smallest area as possible. Ferroelectric thermometer based hybrid technology and electrical resistive thermometer based (microbolometer) technology are under development. LETI and ULIS have chosen from the very beginning to develop first a monolithic microbolometer technology fully compatible with commercially available CMOS technology and secondly amorphous silicon based thermometer. This silicon approach has the greatest potential for reducing infrared detector manufacturing cost. After the development of the technology, the transfer to industrial facilities has been performed in a short period of time and the production is now ramping up with ULIS team in new facilities. LETI and ULIS are now working to facilitate the IRFPA integration into equipment in order to address a very large market. Achievement of this goal needs the development of smart sensors with on-chip advanced functions and the decrease of manufacturing cost of IRFPA by decreasing the pixel pitch and simplifying the vacuum package. We present in this paper the technology developed by CEA/LETI and its improvement for being able to designs 384×288 and 160×120 arrays with a pitch of 35 μm. Thermographic application needs high stability infrared detector with a precise determination of the amount of absorbed infrared flux. Hence, infrared detector with internal temperature stabilized shield has been developed and characterized. These results will be presented. To cite this article: J

  16. Focal dermal hypoplasia without focal dermal hypoplasia

    NARCIS (Netherlands)

    Contreras-Capetillo, Silvina N.; Lombardi, Maria Paola; Pinto-Escalante, Doris; Hennekam, Raoul C.

    2014-01-01

    Focal dermal hypoplasia (FDH; Goltz-Gorlin syndrome) is an X-linked dominant disorder affecting mainly tissues of ectodermal and mesodermal origin. The phenotype is characterized by hypoplastic linear skin lesions, eye malformations, hair and teeth anomalies, and multiple limbs malformations. The

  17. Poster — Thur Eve — 39: Feasibility of Commissioning HybridArc with the Delta 4 two plane diode phantom: comparisons with Gafchromic Film

    Energy Technology Data Exchange (ETDEWEB)

    Bojechko, C. [University of Calgary, Department of Physics and Astronomy, Tom Baker Cancer Center, Calgary AB (Canada); Ploquin, N. [University of Calgary, Department of Physics and Astronomy, Tom Baker Cancer Center, Calgary AB (Canada); University of Calgary, Department of Oncology, Tom Baker Cancer Center, Calgary AB (Canada); Hudson, A. [University of Calgary, Department of Oncology, Tom Baker Cancer Center, Calgary AB (Canada); Sayous, Y. [Université Paul Sabotier Toulouse (France)

    2014-08-15

    HybridArc is a relatively novel radiation therapy technique which combines optimized dynamic conformai arcs (DCA) and intensity modulated radiation therapy (IMRT). HybridArc has possible dosimetry and efficiency advantages over stand alone DCA and IMRT treatments and can be readily implemented on any linac capable of DCA and IMRT, giving strong motivation to commission the modality. The Delta4 phantom (Scandidos, Uppsala, Sweden) has been used for IMRT and VMAT clinical dosimetric verification making it a candidate for HybridArc commissioning. However the HybridArc modality makes use of several non co-planar arcs which creates setup issues due to the geometry of the Delta4, resulting in possible phantom gantry collisions for plans with non-zero couch angles. An analysis was done determining the feasibility of using the Delta4 fixed at 0° couch angle compared with results obtained using Gafchromic ETB2 film (Ashland, Covington Kentucky) in an anthropomorphic phantom at the planned couch angles. A gamma index analysis of the measured and planned dose distributions was done using Delta4 and DoseLab Pro (Mobius Medical Systems, Houston Texas) software. For both arc and IMRT sub-fields there is reasonable correlation between the gamma index found from the Delta4 and Gafchromic film. All results show the feasibility of using the Delta4 for HybridArc commissioning.

  18. Poster — Thur Eve — 39: Feasibility of Commissioning HybridArc with the Delta 4 two plane diode phantom: comparisons with Gafchromic Film

    International Nuclear Information System (INIS)

    Bojechko, C.; Ploquin, N.; Hudson, A.; Sayous, Y.

    2014-01-01

    HybridArc is a relatively novel radiation therapy technique which combines optimized dynamic conformai arcs (DCA) and intensity modulated radiation therapy (IMRT). HybridArc has possible dosimetry and efficiency advantages over stand alone DCA and IMRT treatments and can be readily implemented on any linac capable of DCA and IMRT, giving strong motivation to commission the modality. The Delta4 phantom (Scandidos, Uppsala, Sweden) has been used for IMRT and VMAT clinical dosimetric verification making it a candidate for HybridArc commissioning. However the HybridArc modality makes use of several non co-planar arcs which creates setup issues due to the geometry of the Delta4, resulting in possible phantom gantry collisions for plans with non-zero couch angles. An analysis was done determining the feasibility of using the Delta4 fixed at 0° couch angle compared with results obtained using Gafchromic ETB2 film (Ashland, Covington Kentucky) in an anthropomorphic phantom at the planned couch angles. A gamma index analysis of the measured and planned dose distributions was done using Delta4 and DoseLab Pro (Mobius Medical Systems, Houston Texas) software. For both arc and IMRT sub-fields there is reasonable correlation between the gamma index found from the Delta4 and Gafchromic film. All results show the feasibility of using the Delta4 for HybridArc commissioning

  19. Mesoscale hybrid calibration artifact

    Science.gov (United States)

    Tran, Hy D.; Claudet, Andre A.; Oliver, Andrew D.

    2010-09-07

    A mesoscale calibration artifact, also called a hybrid artifact, suitable for hybrid dimensional measurement and the method for make the artifact. The hybrid artifact has structural characteristics that make it suitable for dimensional measurement in both vision-based systems and touch-probe-based systems. The hybrid artifact employs the intersection of bulk-micromachined planes to fabricate edges that are sharp to the nanometer level and intersecting planes with crystal-lattice-defined angles.

  20. Influence Of Nonuniformity On Infrared Focal Plane Array Performance

    Science.gov (United States)

    Milton, A. F.; Barone, F. R.; Kruer, M. R.

    1985-08-01

    It is well known that detector response nonuniformity results in pattern noise with staring sensors that is a severe problem in the infrared due to the low intrinsic contrast of IR imagery. The pattern noise can be corrected by electronic processing; however, the ability to correct for pattern noise is limited by the interaction of interscene and intrascene variability with the dynamic range of the processor (number of bits) and, depending upon the algorithm used, by nonlinearities in the detector response. This paper quantifies these limitations and describes the interaction of detector gain nonuniformity and detector nonlinearities. Probabilistic models are developed to determine the maximum sensitivity that can be obtained using a two-point algorithm to correct a nonlinear response curve over a wide temperature range. Curves that permit a prediction of the noise equivalent differential temperature (NEAT) under varying circumstances are presented. A piecewise linear approach to dealing with severe detector response nonlinearities is presented and analyzed for its effectiveness.

  1. Advanced uncooled infrared focal plane development at CEA/LETI

    Science.gov (United States)

    Tissot, Jean-Luc; Mottin, Eric; Martin, Jean-Luc; Yon, Jean-Jacques; Vilain, Michel

    2017-11-01

    LETI/LIR has been involved for a few year in the field of uncooled detectors and has chosen amorphous silicon for its microbolometer technology development. Uncooled IR detectors pave the way to reduced weight systems aboard satellites. The silicon compatibility of our thermometer is a key parameter which has enabled a very fast technology development and transfer to industry. This competitive technology is now able to provide a new approach for IR detectors for space applications. This paper presents the main characteristics of the CEA / LETI technology which is based on a monolithically integrated structure over a fully completed readout circuit from a commercially available 0.5 μm design rules CMOS line. The technology maturity will be illustrated by the results obtained at LETI/LIR and SOFRADIR on a 320 x 240 with a pitch of 45 μm. First improvement on device reliability and characterization results will be presented.

  2. Operation of MWDC's in the QDD and QDQ focal planes

    International Nuclear Information System (INIS)

    Distelbrink, J.H.J.

    1980-01-01

    In the multiwire drift chamber (MWDC), the speed of a multiwire proportional chamber and the position accuracy of a drift chamber are combined. A solution to the problem of the curved electric field lines near the wires is discussed. (Auth.)

  3. Low-noise readout circuit for SWIR focal plane arrays

    Science.gov (United States)

    Altun, Oguz; Tasdemir, Ferhat; Nuzumlali, Omer Lutfi; Kepenek, Reha; Inceturkmen, Ercihan; Akyurek, Fatih; Tunca, Can; Akbulut, Mehmet

    2017-02-01

    This paper reports a 640x512 SWIR ROIC with 15um pixel pitch that is designed and fabricated using 0.18um CMOS process. Main challenge of SWIR ROIC design is related to input circuit due to pixel area and noise limitations. In this design, CTIA with single stage amplifier is utilized as input stage. The pixel design has three pixel gain options; High Gain (HG), Medium Gain (MG), and Low Gain (LG) with corresponding Full-Well-Capacities of 18.7ké, 190ké and 1.56Mé, respectively. According to extracted simulation results, 5.9é noise is achieved at HG mode and 200é is achieved at LG mode of operation. The ROIC can be programmed through an SPI interface. It supports 1, 2 and 4 output modes which enables the user to configure the detector to work at 30, 60 and 120fps frame rates. In the 4 output mode, the total power consumption of the ROIC is less than 120mW. The ROIC is powered from a 3.3V analog supply and allows for an output swing range in excess of 2V. Anti-blooming feature is added to prevent any unwanted blooming effect during readout.

  4. A focal plane camera for celestial XUV sources

    International Nuclear Information System (INIS)

    Huizenga, H.

    1980-01-01

    This thesis describes the development and performance of a new type of X-ray camera for the 2-250 0 A wavelength range (XUV). The camera features high position resolution (FWHM approximately 0.2 mm at 2 A, -13 erg/cm 2 s in a one year mission. (Auth.)

  5. A focal plane metrology system and PSF centroiding experiment

    Science.gov (United States)

    Li, Haitao; Li, Baoquan; Cao, Yang; Li, Ligang

    2016-10-01

    In this paper, we present an overview of a detector array equipment metrology testbed and a micro-pixel centroiding experiment currently under development at the National Space Science Center, Chinese Academy of Sciences. We discuss on-going development efforts aimed at calibrating the intra-/inter-pixel quantum efficiency and pixel positions for scientific grade CMOS detector, and review significant progress in achieving higher precision differential centroiding for pseudo star images in large area back-illuminated CMOS detector. Without calibration of pixel positions and intrapixel response, we have demonstrated that the standard deviation of differential centroiding is below 2.0e-3 pixels.

  6. Status of the KATRIN focal-plane detector

    Energy Technology Data Exchange (ETDEWEB)

    Seher, Agnes [Karlsruher Institute of Technology (KIT) (Germany). Institut fuer Kernphysik (IKP); Collaboration: KATRIN-Collaboration

    2016-07-01

    The KArlsruhe TRItium Neutrino (KATRIN) experiment aims to determine the mass of the electron anti-neutrino with a sensitivity of 200 meV/c{sup 2} by measuring the kinematics of tritium β-electrons close to the enpoint of the energy spectrum. The energy analysis of the experiment is performed with a high-resolution electrostatic spectrometer of MAC-E filter type which acts as an integranting high pass filter. Transmitted electrons are counted with a segmented silicon detector system located at the downstream end of the experiment. The detector system consists of two super-conducting solenoids (B{sub max}=6 T), a post-acceleration electrode, a detector wafer with silicon pixel-diodes, readout electronics as well as a calibration and monitoring devices. This talk gives an overview of the detector system and its current status as well as key performance parameters.

  7. MEMS Terahertz Focal Plane Array With Optical Readout

    Science.gov (United States)

    2016-06-01

    heat sink via a thermal insulator (pure SiO2 ) and two bi-material legs formed by Al and SiO2 as shown in Figure 12. 13 Figure 12. THz...The primary doublet lens is made of two different pieces of glass (E- BAF11 and N-SF11) which are cemented together. The respective indices of...BAF11 glass 1.6725 n2 (N-SF11) Index of refraction of N-SF11 glass 1.7975 t1 (E-BAF11) Thickness of E-BAF11 glass 20 mm t2 (N-SF11) Thickness of N

  8. Realistic full wave modeling of focal plane array pixels.

    Energy Technology Data Exchange (ETDEWEB)

    Campione, Salvatore [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Electromagnetic Theory Dept.; Warne, Larry K. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Electromagnetic Theory Dept.; Jorgenson, Roy E. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Electromagnetic Theory Dept.; Davids, Paul [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Applied Photonic Microsystems Dept.; Peters, David W. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Applied Photonic Microsystems Dept.

    2017-11-01

    Here, we investigate full-wave simulations of realistic implementations of multifunctional nanoantenna enabled detectors (NEDs). We focus on a 2x2 pixelated array structure that supports two wavelengths of operation. We design each resonating structure independently using full-wave simulations with periodic boundary conditions mimicking the whole infinite array. We then construct a supercell made of a 2x2 pixelated array with periodic boundary conditions mimicking the full NED; in this case, however, each pixel comprises 10-20 antennas per side. In this way, the cross-talk between contiguous pixels is accounted for in our simulations. We observe that, even though there are finite extent effects, the pixels work as designed, each responding at the respective wavelength of operation. This allows us to stress that realistic simulations of multifunctional NEDs need to be performed to verify the design functionality by taking into account finite extent and cross-talk effects.

  9. Design and alignment of the MIPAS focal plane system

    NARCIS (Netherlands)

    Smorenburg, C.; Visser, H.; Moddemeijer, K.

    1996-01-01

    The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) is selected by ESA for the ENVISAT-mission, scheduled for launch in 1999. The instrument will measure the concentration of atmospheric trace gases in the earth atmosphere in a spectral region from 4.15-14.6 rim. MIPAS consists of

  10. Focal plane optics in far-infrared and submillimeter astronomy

    Science.gov (United States)

    Hildebrand, R. H.

    1985-01-01

    The construction of airborne observatories, high mountain-top observatories, and space observatories designed especially for infrared and submillimeter astronomy has opened fields of research requiring new optical techniques. A typical far-IR photometric study involves measurement of a continuum spectrum in several passbands between approx 30 microns and 1000 microns and diffraction-limited mapping of the source. At these wavelengths, diffraction effects strongly influence the design of the field optics systems which couple the incoming flux to the radiation sensors (cold bolometers). The Airy diffraction disk for a typical telescope at submillimeter wavelengths approx 100 microns-1000 microns is many millimeters in diameter; the size of the field stop must be comparable. The dilute radiation at the stop is fed through a Winston nonimaging concentrator to a small cavity containing the bolometer. The purpose of this paper is to review the principles and techniques of infrared field optics systems, including spectral filters, concentrators, cavities, and bolometers (as optical elements), with emphasis on photometric systems for wavelengths longer than 60 microns.

  11. Focal plane optics in far-infrared and submillimeter astronomy

    Science.gov (United States)

    Hildebrand, R. H.

    1986-02-01

    The construction of airborne observatories, high mountain-top observatories, and space observatories designed especially for infrared and submillimeter astronomy has opened fields of research requiring new optical techniques. A typical far-IR photometric study involves measurement of a continuum spectrum in several passbands between approx 30 microns and 1000 microns and diffraction-limited mapping of the source. At these wavelengths, diffraction effects strongly influence the design of the field optics systems which couple the incoming flux to the radiation sensors (cold bolometers). The Airy diffraction disk for a typical telescope at submillimeter wavelengths approx 100 microns-1000 microns is many millimeters in diameter; the size of the field stop must be comparable. The dilute radiation at the stop is fed through a Winston nonimaging concentrator to a small cavity containing the bolometer. The purpose of this paper is to review the principles and techniques of infrared field optics systems, including spectral filters, concentrators, cavities, and bolometers (as optical elements), with emphasis on photometric systems for wavelengths longer than 60 microns.

  12. Focal retinal phlebitis.

    Science.gov (United States)

    Hoang, Quan V; Freund, K Bailey; Klancnik, James M; Sorenson, John A; Cunningham, Emmett T; Yannuzzi, Lawrence A

    2012-01-01

    To report three cases of solitary, focal retinal phlebitis. An observational case series. Three eyes in three patients were noted to have unilateral decreased vision, macular edema, and a focal retinal phlebitis, which was not at an arteriovenous crossing. All three patients developed a branch retinal vein occlusion at the site of inflammation. These patients had no other evidence of intraocular inflammation, including vitritis, retinitis, retinal vasculitis, or choroiditis, nor was there any systemic disorder associated with inflammation, infection, or coagulation identified. Focal retinal phlebitis appears to be an uncommon and unique entity that produces macular edema and ultimately branch retinal vein occlusion. In our patients, the focal phlebitis and venous occlusion did not occur at an arteriovenous crossing, which is the typical site for branch retinal venous occlusive disease. This suggests that our cases represent a distinct clinical entity, which starts with a focal abnormality in the wall of a retinal venule, resulting in surrounding exudation and, ultimately, ends with branch retinal vein occlusion.

  13. Recurrent Bilateral Focal Myositis.

    Science.gov (United States)

    Nagafuchi, Hiroko; Nakano, Hiromasa; Ooka, Seido; Takakuwa, Yukiko; Yamada, Hidehiro; Tadokoro, Mamoru; Shimojo, Sadatomo; Ozaki, Shoichi

    This report describes a rare case of recurrent bilateral focal myositis and its successful treatment via methotrexate. A 38-year-old man presented myalgia of the right gastrocnemius in May 2005. Magnetic resonance imaging showed very high signal intensity in the right gastrocnemius on short-tau inversion recovery images. A muscle biopsy revealed inflammatory CD4+ cell-dominant myogenic change. Focal myositis was diagnosed. The first steroid treatment was effective. Tapering of prednisolone, however, repeatedly induced myositis relapse, which progressed to multiple muscle lesions of both lower limbs. Initiation of methotrexate finally allowed successful tapering of prednisolone, with no relapse in the past 4 years.

  14. Experimental Focal Cerebral Ischemia

    DEFF Research Database (Denmark)

    Christensen, Thomas

    2007-01-01

    Focal cerebral ischemia due to occlusion of a major cerebral artery is the cause of ischemic stroke which is a major reason of mortality, morbidity and disability in the populations of the developed countries. In the seven studies summarized in the thesis focal ischemia in rats induced by occlusion...... in the penumbra is recruited in the infarction process leading to a progressive growth of the infarct. The penumbra hence constitutes an important target for pharmacological treatment because of the existence of a therapeutic time window during which treatment with neuroprotective compounds may prevent...

  15. Optically sectioned imaging by oblique plane microscopy

    Science.gov (United States)

    Kumar, Sunil; Lin, Ziduo; Lyon, Alex R.; MacLeod, Ken T.; Dunsby, Chris

    2011-03-01

    Oblique Plane Microscopy (OPM) is a light sheet microscopy technique that combines oblique illumination with correction optics that tilt the focal plane of the collection system. OPM can be used to image conventionally mounted specimens on coverslips or tissue culture dishes and has low out-of-plane photobleaching and phototoxicity. No moving parts are required to achieve an optically sectioned image and so high speed optically sectioned imaging is possible. The first OPM results obtained using a high NA water immersion lens on a commercially available inverted microscope frame are presented, together with a measurement of the achievable optical resolution.

  16. Focal myositis: A review.

    Science.gov (United States)

    Devic, P; Gallay, L; Streichenberger, N; Petiot, P

    2016-11-01

    Amongst the heterogeneous group of inflammatory myopathies, focal myositis stands as a rare and benign dysimmune disease. Although it can be associated with root and/or nerve lesions, traumatic muscle lesions and autoimmune diseases, its triggering factors remain poorly understood. Defined as an isolated inflammatory pseudotumour usually restricted to one skeletal muscle, clinical presentation of focal myositis is that of a rapidly growing solitary mass within a single muscle, usually in the lower limbs. Electromyography shows spontaneous activity associated with a myopathic pattern. MRI reveals a contrast enhanced enlarged muscle appearing hyper-intense on FAT-SAT T2 weighted images. Adjacent structures are spared and there are no calcifications. Serum creatine kinase (CK) levels are usually moderately augmented and biological markers of systemic inflammation are absent in most cases. Pathological histological features include marked variation in fibre size, inflammatory infiltrates mostly composed of T CD4+ lymphocytes and macrophages, degenerating/regenerating fibres and interstitial fibrosis. Differential diagnoses are numerous and include myositis of other origin with focal onset. Steroid treatment should be reserved for patients who present with major pain, nerve lesions, associated autoimmune disease, or elevated C reactive protein or CK. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Method for measuring the focal spot size of an x-ray tube using a coded aperture mask and a digital detector.

    Science.gov (United States)

    Russo, Paolo; Mettivier, Giovanni

    2011-04-01

    The goal of this study is to evaluate a new method based on a coded aperture mask combined with a digital x-ray imaging detector for measurements of the focal spot sizes of diagnostic x-ray tubes. Common techniques for focal spot size measurements employ a pinhole camera, a slit camera, or a star resolution pattern. The coded aperture mask is a radiation collimator consisting of a large number of apertures disposed on a predetermined grid in an array, through which the radiation source is imaged onto a digital x-ray detector. The method of the coded mask camera allows one to obtain a one-shot accurate and direct measurement of the two dimensions of the focal spot (like that for a pinhole camera) but at a low tube loading (like that for a slit camera). A large number of small apertures in the coded mask operate as a "multipinhole" with greater efficiency than a single pinhole, but keeping the resolution of a single pinhole. X-ray images result from the multiplexed output on the detector image plane of such a multiple aperture array, and the image of the source is digitally reconstructed with a deconvolution algorithm. Images of the focal spot of a laboratory x-ray tube (W anode: 35-80 kVp; focal spot size of 0.04 mm) were acquired at different geometrical magnifications with two different types of digital detector (a photon counting hybrid silicon pixel detector with 0.055 mm pitch and a flat panel CMOS digital detector with 0.05 mm pitch) using a high resolution coded mask (type no-two-holes-touching modified uniformly redundant array) with 480 0.07 mm apertures, designed for imaging at energies below 35 keV. Measurements with a slit camera were performed for comparison. A test with a pinhole camera and with the coded mask on a computed radiography mammography unit with 0.3 mm focal spot was also carried out. The full width at half maximum focal spot sizes were obtained from the line profiles of the decoded images, showing a focal spot of 0.120 mm x 0.105 mm at 35

  18. Morphological spot counting from stacked images for automated analysis of gene copy numbers by fluorescence in situ hybridization.

    Science.gov (United States)

    Grigoryan, Artyom M; Dougherty, Edward R; Kononen, Juha; Bubendorf, Lukas; Hostetter, Galen; Kallioniemi, Olli

    2002-01-01

    Fluorescence in situ hybridization (FISH) is a molecular diagnostic technique in which a fluorescent labeled probe hybridizes to a target nucleotide sequence of deoxyribose nucleic acid. Upon excitation, each chromosome containing the target sequence produces a fluorescent signal (spot). Because fluorescent spot counting is tedious and often subjective, automated digital algorithms to count spots are desirable. New technology provides a stack of images on multiple focal planes throughout a tissue sample. Multiple-focal-plane imaging helps overcome the biases and imprecision inherent in single-focal-plane methods. This paper proposes an algorithm for global spot counting in stacked three-dimensional slice FISH images without the necessity of nuclei segmentation. It is designed to work in complex backgrounds, when there are agglomerated nuclei, and in the presence of illumination gradients. It is based on the morphological top-hat transform, which locates intensity spikes on irregular backgrounds. After finding signals in the slice images, the algorithm groups these together to form three-dimensional spots. Filters are employed to separate legitimate spots from fluorescent noise. The algorithm is set in a comprehensive toolbox that provides visualization and analytic facilities. It includes simulation software that allows examination of algorithm performance for various image and algorithm parameter settings, including signal size, signal density, and the number of slices.

  19. Focal femoral condyle resurfacing.

    LENUS (Irish Health Repository)

    Brennan, S A

    2013-03-01

    Focal femoral inlay resurfacing has been developed for the treatment of full-thickness chondral defects of the knee. This technique involves implanting a defect-sized metallic or ceramic cap that is anchored to the subchondral bone through a screw or pin. The use of these experimental caps has been advocated in middle-aged patients who have failed non-operative methods or biological repair techniques and are deemed unsuitable for conventional arthroplasty because of their age. This paper outlines the implant design, surgical technique and biomechanical principles underlying their use. Outcomes following implantation in both animal and human studies are also reviewed. Cite this article: Bone Joint J 2013;95-B:301-4.

  20. Systemic focal epileptogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Remler, M.P.; Marcussen, W.H.

    1986-01-01

    Rats that receive radiation to 0.25 cc of one cerebral hemisphere are clinically and electroencephalographically normal until there is a breakdown of the blood-brain barrier (BBB) at 3 to 6 months postradiation. This BBB lesion can be detected by transient focal seizure activity produced by the BBB-excluded systemic convulsant bicuculline methiodide. In two rats the seizure activity induced by this one injection was self-sustaining. In seven of 15 other rats tested, the subsequent administration of repeated 2 mg/kg injections created a chronic focus that continued to spike with great frequency for 3 weeks or more without further administration of any convulsant. In three of eight other rats, implanted minipumps delivering 180 micrograms/h of bicuculline methiodide produced self-sustaining epileptic activity.

  1. Inverse-designed stretchable metalens with tunable focal distance

    Science.gov (United States)

    Callewaert, Francois; Velev, Vesselin; Jiang, Shizhou; Sahakian, Alan Varteres; Kumar, Prem; Aydin, Koray

    2018-02-01

    In this paper, we present an inverse-designed 3D-printed all-dielectric stretchable millimeter wave metalens with a tunable focal distance. A computational inverse-design method is used to design a flat metalens made of disconnected polymer building blocks with complex shapes, as opposed to conventional monolithic lenses. The proposed metalens provides better performance than a conventional Fresnel lens, using lesser amount of material and enabling larger focal distance tunability. The metalens is fabricated using a commercial 3D-printer and attached to a stretchable platform. Measurements and simulations show that the focal distance can be tuned by a factor of 4 with a stretching factor of only 75%, a nearly diffraction-limited focal spot, and with a 70% relative focusing efficiency, defined as the ratio between power focused in the focal spot and power going through the focal plane. The proposed platform can be extended for design and fabrication of multiple electromagnetic devices working from visible to microwave radiation depending on scaling of the devices.

  2. Focal midbrain tumors in children

    NARCIS (Netherlands)

    Vandertop, W. P.; Hoffman, H. J.; Drake, J. M.; Humphreys, R. P.; Rutka, J. T.; Amstrong, D. C.; Becker, L. E.

    1992-01-01

    The clinical and neuroradiological features of focal midbrain tumors in 12 children are described, and the results of their surgical management are presented. Patients with a focal midbrain tumor usually exhibit either symptoms and signs of raised intracranial pressure caused by an obstructive

  3. Strong reducing of the laser focal volume

    CSIR Research Space (South Africa)

    Godin, T

    2011-08-01

    Full Text Available equal to -1 or +1 modeled on the p light rings of the incident TEMp0 beam. The transformation quality of a 30TEM beam into a single-lobed pattern in the focal plane is shown in Fig. 3. It is clear that the intensity pattern of the rectified beam... DOE (blue solid line), rectified 30TEM (red solid line) -3 -2 -1 0 1 2 3 0 1 2 3 4 z=0 z=f DOE Fig. 2 -60 -50 -40 -30 -20 -10 0 10 20 30 40 50 60 0,0 0,2 0,4 0,6 0,8 1,0 TEM30 without DOE "rectified" TEM30 TEM00 In te ns...

  4. Diagnostic imaging in focal epilepsy

    International Nuclear Information System (INIS)

    Zlatareva, D.

    2013-01-01

    Focal epilepsies account for 60% of all seizure disorders worldwide. In this review the classic and new classification system of epileptic seizures and syndromes as well as genetic forms are discussed. Magnetic resonance (MR) is the technique of choice for diagnostic imaging in focal epilepsy because of its sensitivity and high tissue contrast. The review is focused on the lack of consensus of imaging protocols and reported findings in refractory epilepsy. The most frequently encountered MRI findings in epilepsy are reported and their imaging characteristics are depicted. Diagnosis of hippocampal sclerosis and malformations of cortical development as two major causes of refractory focal epilepsy is described in details. Some promising new techniques as positron emission tomography computed tomography (PET/CT) and MR and PET/CT fusion are briefly discussed. Also the relevance of adequate imaging in focal epilepsy, some practical points in imaging interpretation and differential diagnosis are highlighted. (author)

  5. Earthquake source parameter and focal mechanism estimates for the Western Quebec Seismic Zone in eastern Canada

    Science.gov (United States)

    Rodriguez Padilla, A. M.; Onwuemeka, J.; Liu, Y.; Harrington, R. M.

    2017-12-01

    The Western Quebec Seismic Zone (WQSZ) is a 160-km-wide band of intraplate seismicity extending 500 km from the Adirondack Highlands (United States) to the Laurentian uplands (Canada). Historically, the WQSZ has experienced over fifteen earthquakes above magnitude 5, with the noteworthy MN5.2 Ladysmith event on May 17, 2013. Previous studies have associated seismicity in the area to the reactivation of Early Paleozoic normal faults within a failed Iapetan rift arm, or strength contrasts between mafic intrusions and felsic rocks due to the Mesozoic track of the Great Meteor hotspot. A good understanding of seismicity and its relation to pre-existing structures requires information about event source properties, such as static stress drop and fault plane orientation, which can be constrained via spectral analysis and focal mechanism solutions. Using data recorded by the CNSN and USArray Transportable Array, we first characterize b-value for 709 events between 2012 and 2016 in WQSZ, obtaining a value of 0.75. We then determine corner frequency and seismic moment values by fitting S-wave spectra on transverse components at all stations for 35 events MN 2.7+. We select event pairs with highly similar waveforms, proximal hypocenters, and magnitudes differing by 1-2 units. Our preliminary results using single-station spectra show corner frequencies of 15 to 40 Hz and stress drop values between 7 and 130 MPa, typical of intraplate seismicity. Last, we solve focal mechanism solutions of 35 events with impulsive P-wave arrivals at a minimum of 8 stations using the hybridMT moment tensor inversion algorithm. Our preliminary results suggest predominantly thrust faulting mechanisms, and at times oblique thrust faulting. The P-axis trend of the focal mechanism solutions suggests a principal stress orientation of NE-SW, which is consistent with that derived from focal mechanisms of earthquakes prior to 2013. We plan to fit the event pair spectral ratios to correct for attenuation

  6. New family of exact solutions for colliding plane gravitational waves

    International Nuclear Information System (INIS)

    Yurtsever, U.

    1988-01-01

    We construct an infinite-parameter family of exact solutions to the vacuum Einstein field equations describing colliding gravitational plane waves with parallel polarizations. The interaction regions of the solutions in this family are locally isometric to the interiors of those static axisymmetric (Weyl) black-hole solutions which admit both a nonsingular horizon, and an analytic extension of the exterior metric to the interior of the horizon. As a member of this family of solutions we also obtain, for the first time, a colliding plane-wave solution where both of the two incoming plane waves are purely anastigmatic, i.e., where both incoming waves have equal focal lengths

  7. Existence of Projective Planes

    OpenAIRE

    Perrott, Xander

    2016-01-01

    This report gives an overview of the history of finite projective planes and their properties before going on to outline the proof that no projective plane of order 10 exists. The report also investigates the search carried out by MacWilliams, Sloane and Thompson in 1970 [12] and confirms their result by providing independent verification that there is no vector of weight 15 in the code generated by the projective plane of order 10.

  8. Continuously variable focal length lens

    Science.gov (United States)

    Adams, Bernhard W; Chollet, Matthieu C

    2013-12-17

    A material preferably in crystal form having a low atomic number such as beryllium (Z=4) provides for the focusing of x-rays in a continuously variable manner. The material is provided with plural spaced curvilinear, optically matched slots and/or recesses through which an x-ray beam is directed. The focal length of the material may be decreased or increased by increasing or decreasing, respectively, the number of slots (or recesses) through which the x-ray beam is directed, while fine tuning of the focal length is accomplished by rotation of the material so as to change the path length of the x-ray beam through the aligned cylindrical slows. X-ray analysis of a fixed point in a solid material may be performed by scanning the energy of the x-ray beam while rotating the material to maintain the beam's focal point at a fixed point in the specimen undergoing analysis.

  9. Miniaturized Fourier-plane fiber scanner for OCT endoscopy

    International Nuclear Information System (INIS)

    Vilches, Sergio; Kretschmer, Simon; Ataman, Çağlar; Zappe, Hans

    2017-01-01

    A forward-looking endoscopic optical coherence tomography (OCT) probe featuring a Fourier-plane fiber scanner is designed, manufactured and characterized. In contrast to common image-plane fiber scanners, the Fourier-plane scanner is a telecentric arrangement that eliminates vignetting and spatial resolution variations across the image plane. To scan the OCT beam in a spiral pattern, a tubular piezoelectric actuator is used to resonate an optical fiber bearing a collimating GRIN lens at its tip. The free-end of the GRIN lens sits at the back focal plane of an objective lens, such that its rotation replicates the beam angles in the collimated region of a classical telecentric 4f optical system. Such an optical arrangement inherently has a low numerical aperture combined with a relatively large field-of-view, rendering it particularly useful for endoscopic OCT imaging. Furthermore, the optical train of the Fourier-plane scanner is shorter than that of a comparable image-plane scanner by one focal length of the objective lens, significantly shortening the final arrangement. As a result, enclosed within a 3D printed housing of 2.5 mm outer diameter and 15 mm total length, the developed probe is the most compact forward-looking endoscopic OCT imager to date. Due to its compact form factor and compatibility with real-time OCT imaging, the developed probe is also ideal for use in the working channel of flexible endoscopes as a potential optical biopsy tool. (paper)

  10. Miniaturized Fourier-plane fiber scanner for OCT endoscopy

    Science.gov (United States)

    Vilches, Sergio; Kretschmer, Simon; Ataman, Çağlar; Zappe, Hans

    2017-10-01

    A forward-looking endoscopic optical coherence tomography (OCT) probe featuring a Fourier-plane fiber scanner is designed, manufactured and characterized. In contrast to common image-plane fiber scanners, the Fourier-plane scanner is a telecentric arrangement that eliminates vignetting and spatial resolution variations across the image plane. To scan the OCT beam in a spiral pattern, a tubular piezoelectric actuator is used to resonate an optical fiber bearing a collimating GRIN lens at its tip. The free-end of the GRIN lens sits at the back focal plane of an objective lens, such that its rotation replicates the beam angles in the collimated region of a classical telecentric 4f optical system. Such an optical arrangement inherently has a low numerical aperture combined with a relatively large field-of-view, rendering it particularly useful for endoscopic OCT imaging. Furthermore, the optical train of the Fourier-plane scanner is shorter than that of a comparable image-plane scanner by one focal length of the objective lens, significantly shortening the final arrangement. As a result, enclosed within a 3D printed housing of 2.5 mm outer diameter and 15 mm total length, the developed probe is the most compact forward-looking endoscopic OCT imager to date. Due to its compact form factor and compatibility with real-time OCT imaging, the developed probe is also ideal for use in the working channel of flexible endoscopes as a potential optical biopsy tool.

  11. Earthquake focal mechanism forecasting in Italy for PSHA purposes

    Science.gov (United States)

    Roselli, Pamela; Marzocchi, Warner; Mariucci, Maria Teresa; Montone, Paola

    2018-01-01

    In this paper, we put forward a procedure that aims to forecast focal mechanism of future earthquakes. One of the primary uses of such forecasts is in probabilistic seismic hazard analysis (PSHA); in fact, aiming at reducing the epistemic uncertainty, most of the newer ground motion prediction equations consider, besides the seismicity rates, the forecast of the focal mechanism of the next large earthquakes as input data. The data set used to this purpose is relative to focal mechanisms taken from the latest stress map release for Italy containing 392 well-constrained solutions of events, from 1908 to 2015, with Mw ≥ 4 and depths from 0 down to 40 km. The data set considers polarity focal mechanism solutions until to 1975 (23 events), whereas for 1976-2015, it takes into account only the Centroid Moment Tensor (CMT)-like earthquake focal solutions for data homogeneity. The forecasting model is rooted in the Total Weighted Moment Tensor concept that weighs information of past focal mechanisms evenly distributed in space, according to their distance from the spatial cells and magnitude. Specifically, for each cell of a regular 0.1° × 0.1° spatial grid, the model estimates the probability to observe a normal, reverse, or strike-slip fault plane solution for the next large earthquakes, the expected moment tensor and the related maximum horizontal stress orientation. These results will be available for the new PSHA model for Italy under development. Finally, to evaluate the reliability of the forecasts, we test them with an independent data set that consists of some of the strongest earthquakes with Mw ≥ 3.9 occurred during 2016 in different Italian tectonic provinces.

  12. Focal therapy in prostate cancer

    NARCIS (Netherlands)

    van den Bos, W.

    2016-01-01

    Interesting developments took place in the treatment of prostate cancer including focal therapy for less aggressive organ-confined prostate cancer. Fortunately, curative treatment is often still an option for patients suffering from the lower staged tumors. In carefully selected patients, the

  13. Gallbladder adenoma with focal adenocarcinoma.

    Science.gov (United States)

    Ciurea, S; Matei, E; Petrisor, P; Luca, L; Boros, Mirela; Herlea, V; Popescu, I

    2008-01-01

    The majority of polypoid lesions of the gallbladder are cholesterolosis pseudopolyps. True neoplastic GB polyps are represented mainly by adenomas. The case of a 52-year old male patient with an adenomatous polyp of the GB with focal adenocarcinoma is presented.

  14. Charging as a Focal Practice

    DEFF Research Database (Denmark)

    Bødker, Mads

    This position paper reflects on Borgmann’s notion of ‘focal things’ and its applicability in the discourse about interaction with technologies in nature. Using the example of a combined cooking burner and thermoelectric 5W smartphone charger (a BioLite cook stove), this position paper gives...

  15. Cross plane scattering correction

    International Nuclear Information System (INIS)

    Shao, L.; Karp, J.S.

    1990-01-01

    Most previous scattering correction techniques for PET are based on assumptions made for a single transaxial plane and are independent of axial variations. These techniques will incorrectly estimate the scattering fraction for volumetric PET imaging systems since they do not take the cross-plane scattering into account. In this paper, the authors propose a new point source scattering deconvolution method (2-D). The cross-plane scattering is incorporated into the algorithm by modeling a scattering point source function. In the model, the scattering dependence both on axial and transaxial directions is reflected in the exponential fitting parameters and these parameters are directly estimated from a limited number of measured point response functions. The authors' results comparing the standard in-plane point source deconvolution to the authors' cross-plane source deconvolution show that for a small source, the former technique overestimates the scatter fraction in the plane of the source and underestimate the scatter fraction in adjacent planes. In addition, the authors also propose a simple approximation technique for deconvolution

  16. Fourier plane imaging microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez, Daniel, E-mail: daniel.dominguez@ttu.edu; Peralta, Luis Grave de [Department of Physics, Texas Tech University, Lubbock, Texas 79409 (United States); Nano Tech Center, Texas Tech University, Lubbock, Texas 79409 (United States); Alharbi, Nouf; Alhusain, Mdhaoui [Department of Physics, Texas Tech University, Lubbock, Texas 79409 (United States); Bernussi, Ayrton A. [Nano Tech Center, Texas Tech University, Lubbock, Texas 79409 (United States); Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, Texas 79409 (United States)

    2014-09-14

    We show how the image of an unresolved photonic crystal can be reconstructed using a single Fourier plane (FP) image obtained with a second camera that was added to a traditional compound microscope. We discuss how Fourier plane imaging microscopy is an application of a remarkable property of the obtained FP images: they contain more information about the photonic crystals than the images recorded by the camera commonly placed at the real plane of the microscope. We argue that the experimental results support the hypothesis that surface waves, contributing to enhanced resolution abilities, were optically excited in the studied photonic crystals.

  17. Magnetic electroanatomical mapping for ablation of focal atrial tachycardias.

    Science.gov (United States)

    Marchlinski, F; Callans, D; Gottlieb, C; Rodriguez, E; Coyne, R; Kleinman, D

    1998-08-01

    Uniform success for ablation of focal atrial tachycardias has been difficult to achieve using standard catheter mapping and ablation techniques. In addition, our understanding of the complex relationship between atrial anatomy, electrophysiology, and surface ECG P wave morphology remains primitive. The magnetic electroanatomical mapping and display system (CARTO) offers an on-line display of electrical activation and/or signal amplitude related to the anatomical location of the recorded sites in the mapped chamber. A window of electrical interest is established based on signals timed from an electrical reference that usually represents a fixed electrogram recording from the coronary sinus or the atrial appendage. This window of electrical interest is established to include atrial activation prior to the onset of the P wave activity associated with the site of origin of a focal atrial tachycardia. Anatomical and electrical landmarks are defined with limited fluoroscopic imaging support and more detailed global chamber and more focal atrial mapping can be performed with minimal fluoroscopic guidance. A three-dimensional color map representing atrial activation or voltage amplitude at the magnetically defined anatomical sites is displayed with on-line data acquisition. This display can be manipulated to facilitate viewing from any angle. Altering the zoom control, triangle fill threshold, clipping plane, or color range can all enhance the display of a more focal area of interest. We documented the feasibility of using this single mapping catheter technique for localizing and ablating focal atrial tachycardias. In a consecutive series of 8 patients with 9 focal atrial tachycardias, the use of the single catheter CARTO mapping system was associated with ablation success in all but one patient who had a left atrial tachycardia localized to the medial aspect of the orifice of the left atrial appendage. Only low power energy delivery was used in this patient because of the

  18. Instabilities of Kirkendall planes

    NARCIS (Netherlands)

    Dal, van M.J.H.; Gusak, A.M.; Cserhati, C.; Kodentsov, A.; Loo, van F.J.J.

    2001-01-01

    Reconsideration of the Kirkendall effect is presented. It is demonstrated (experimentally as well as theoretically) that Kirkendall planes can be multiple, stable or unstable within a single-phase reaction zone. A general criterion of instabilty is given.

  19. [Focal myositis: An unknown disease].

    Science.gov (United States)

    Gallay, L; Streichenberger, N; Benveniste, O; Allenbach, Y

    2017-10-01

    Focal myositis are inflammatory muscle diseases of unknown origin. At the opposite from the other idiopathic inflammatory myopathies, they are restricted to a single muscle or to a muscle group. They are not associated with extramuscular manifestations, and they have a good prognosis without any treatment. They are characterized by a localized swelling affecting mostly lower limbs. The pseudo-tumor can be painful, but is not associated with a muscle weakness. Creatine kinase level is normal. Muscle MRI shows an inflammation restricted to a muscle or a muscle group. Muscle biopsy and pathological analysis remain necessary for the diagnosis, showing inflammatory infiltrates composed by macrophages and lymphocytes without any specific distribution within the muscle. Focal overexpression of HLA-1 by the muscle fibers is frequently observed. The muscle biopsy permits to rule out differential diagnosis such a malignancy (sarcoma). Spontaneous remission occurs within weeks or months after the first symptoms, relapse is unusual. Copyright © 2017. Published by Elsevier SAS.

  20. Algebraic Structures on MOD Planes

    OpenAIRE

    Kandasamy, Vasantha; Ilanthenral, K.; Smarandache, Florentin

    2015-01-01

    Study of MOD planes happens to a very recent one. In this book, systematically algebraic structures on MOD planes like, MOD semigroups, MOD groups and MOD rings of different types are defined and studied. Such study is innovative for a large four quadrant planes are made into a small MOD planes. Several distinct features enjoyed by these MOD planes are defined, developed and described.

  1. Focal cortical dysplasia – review

    International Nuclear Information System (INIS)

    Kabat, Joanna; Król, Przemysław

    2012-01-01

    Focal cortical dysplasia is a malformation of cortical development, which is the most common cause of medically refractory epilepsy in the pediatric population and the second/third most common etiology of medically intractable seizures in adults. Both genetic and acquired factors are involved in the pathogenesis of cortical dysplasia. Numerous classifications of the complex structural abnormalities of focal cortical dysplasia have been proposed – from Taylor et al. in 1971 to the last modification of Palmini classification made by Blumcke in 2011. In general, three types of cortical dysplasia are recognized. Type I focal cortical dysplasia with mild symptomatic expression and late onset, is more often seen in adults, with changes present in the temporal lobe. Clinical symptoms are more severe in type II of cortical dysplasia usually seen in children. In this type, more extensive changes occur outside the temporal lobe with predilection for the frontal lobes. New type III is one of the above dysplasias with associated another principal lesion as hippocampal sclerosis, tumor, vascular malformation or acquired pathology during early life. Brain MRI imaging shows abnormalities in the majority of type II dysplasias and in only some of type I cortical dysplasias. The most common findings on MRI imaging include: focal cortical thickening or thinning, areas of focal brain atrophy, blurring of the gray-white junction, increased signal on T2- and FLAIR-weighted images in the gray and subcortical white matter often tapering toward the ventricle. On the basis of the MRI findings, it is possible to differentiate between type I and type II cortical dysplasia. A complete resection of the epileptogenic zone is required for seizure-free life. MRI imaging is very helpful to identify those patients who are likely to benefit from surgical treatment in a group of patients with drug-resistant epilepsy. However, in type I cortical dysplasia, MR imaging is often normal, and also in both

  2. TRIM15 is a focal adhesion protein that regulates focal adhesion disassembly

    Science.gov (United States)

    Uchil, Pradeep D.; Pawliczek, Tobias; Reynolds, Tracy D.; Ding, Siyuan; Hinz, Angelika; Munro, James B.; Huang, Fang; Floyd, Robert W.; Yang, Haitao; Hamilton, William L.; Bewersdorf, Joerg; Xiong, Yong; Calderwood, David A.; Mothes, Walther

    2014-01-01

    ABSTRACT Focal adhesions are macromolecular complexes that connect the actin cytoskeleton to the extracellular matrix. Dynamic turnover of focal adhesions is crucial for cell migration. Paxillin is a multi-adaptor protein that plays an important role in regulating focal adhesion dynamics. Here, we identify TRIM15, a member of the tripartite motif protein family, as a paxillin-interacting factor and a component of focal adhesions. TRIM15 localizes to focal contacts in a myosin-II-independent manner by an interaction between its coiled-coil domain and the LD2 motif of paxillin. Unlike other focal adhesion proteins, TRIM15 is a stable focal adhesion component with restricted mobility due to its ability to form oligomers. TRIM15-depleted cells display impaired cell migration and reduced focal adhesion disassembly rates, in addition to enlarged focal adhesions. Thus, our studies demonstrate a cellular function for TRIM15 as a regulatory component of focal adhesion turnover and cell migration. PMID:25015296

  3. Transformational plane geometry

    CERN Document Server

    Umble, Ronald N

    2014-01-01

    Axioms of Euclidean Plane Geometry The Existence and Incidence Postulates The Distance and Ruler Postulates The Plane Separation Postulate The Protractor Postulate The Side-Angle-Side Postulate and the Euclidean Parallel Postulate Theorems of Euclidean Plane Geometry The Exterior Angle Theorem Triangle Congruence Theorems The Alternate Interior Angles Theorem and the Angle Sum Theorem Similar Triangles Introduction to Transformations, Isometries, and Similarities Transformations Isometries and SimilaritiesAppendix: Proof of Surjectivity Translations, Rotations, and Reflections Translations Rotations Reflections Appendix: Geometer's Sketchpad Commands Required by Exploratory Activities Compositions of Translations, Rotations, and Reflections The Three Points Theorem Rotations as Compositions of Two Reflections Translations as Compositions of Two Halfturns or Two Reflections The Angle Addition Theorem Glide Reflections Classification of Isometries The Fundamental Theorem and Congruence Classification of Isometr...

  4. Fast Plane Wave Imaging

    DEFF Research Database (Denmark)

    Jensen, Jonas

    This PhD project investigates and further develops methods for ultrasound plane wave imaging and blood flow estimation with the objective of overcoming some of the major limitations in conventional ultrasound systems, which are related to low frame rates and only estimation of velocities along...... the ultrasound beam. The first part of the contribution investigates the compromise between frame rate and plane wave image quality including the influence of grating lobes from a λ-pitch transducer. A method for optimizing the image quality is suggested, and it is shown that the frame rate can be increased...... healthy volunteers. Complex flow patterns were measured in an anthropomorphic flow phantom and showed good agreement with the velocity field simulated using computational fluid dynamics. The last part of the contribution investigates two clinical applications. Plane wave imaging was used for slow velocity...

  5. Heterogeneity of Focal Adhesions and Focal Contacts in Motile Fibroblasts.

    Science.gov (United States)

    Gladkikh, Aleena; Kovaleva, Anastasia; Tvorogova, Anna; Vorobjev, Ivan A

    2018-01-01

    Cell-extracellular matrix (ECM) adhesion is an important property of virtually all cells in multicellular organisms. Cell-ECM adhesion studies, therefore, are very significant both for biology and medicine. Over the last three decades, biomedical studies resulted in a tremendous advance in our understanding of the molecular basis and functions of cell-ECM adhesion. Based on morphological and molecular criteria, several different types of model cell-ECM adhesion structures including focal adhesions, focal complexes, fibrillar adhesions, podosomes, and three-dimensional matrix adhesions have been described. All the subcellular structures that mediate cell-ECM adhesion are quite heterogeneous, often varying in size, shape, distribution, dynamics, and, to a certain extent, molecular constituents. The morphological "plasticity" of cell-ECM adhesion perhaps reflects the needs of cells to sense, adapt, and respond to a variety of extracellular environments. In addition, cell type (e.g., differentiation status, oncogenic transformation, etc.) often exerts marked influence on the structure of cell-ECM adhesions. Although molecular, genetic, biochemical, and structural studies provide important maps or "snapshots" of cell-ECM adhesions, the area of research that is equally valuable is to study the heterogeneity of FA subpopulations within cells. Recently time-lapse observations on the FA dynamics become feasible, and behavior of individual FA gives additional information on cell-ECM interactions. Here we describe a robust method of labeling of FA using plasmids with fluorescent markers for paxillin and vinculin and quantifying the morphological and dynamical parameters of FA.

  6. Implementation of focal zooming on the Nike KrF laser

    Energy Technology Data Exchange (ETDEWEB)

    Kehne, D. M.; Karasik, M.; Weaver, J. L.; Chan, Y.; Obenschain, S. P. [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Aglitsky, Y. [Science Applications International, McLean, Virginia 22150 (United States); Smyth, Z.; Lehmberg, R. H. [Research Support Instruments, Inc., Lanham, Maryland 20706 (United States); Terrell, S. [Commonwealth Technologies, Inc., Alexandria, Virginia 22315 (United States)

    2013-01-15

    In direct drive inertial confinement laser fusion, a pellet containing D-T fuel is imploded by ablation arising from absorption of laser energy at its outer surface. For optimal coupling, the focal spot of the laser would continuously decrease to match the reduction in the pellet's diameter, thereby minimizing wasted energy. A krypton-fluoride laser ({lambda}= 248 nm) that incorporates beam smoothing by induced spatial incoherence has the ability to produce a high quality focal profile whose diameter varies with time, a property known as focal zooming. A two-stage focal zoom has been demonstrated on the Nike laser at the Naval Research Laboratory. In the experiment, a 4.4 ns laser pulse was created in which the on-target focal spot diameter was 1.3 mm (full width at half maximum) for the first 2.4 ns and 0.28 mm for the final 2 ns. These two diameters appear in time-integrated focal plane equivalent images taken at several locations in the amplification chain. Eight of the zoomed output beams were overlapped on a 60 {mu}m thick planar polystyrene target. Time resolved images of self-emission from the rear of the target show the separate shocks launched by the two corresponding laser focal diameters.

  7. Implementation of focal zooming on the Nike KrF laser

    International Nuclear Information System (INIS)

    Kehne, D. M.; Karasik, M.; Weaver, J. L.; Chan, Y.; Obenschain, S. P.; Aglitsky, Y.; Smyth, Z.; Lehmberg, R. H.; Terrell, S.

    2013-01-01

    In direct drive inertial confinement laser fusion, a pellet containing D-T fuel is imploded by ablation arising from absorption of laser energy at its outer surface. For optimal coupling, the focal spot of the laser would continuously decrease to match the reduction in the pellet's diameter, thereby minimizing wasted energy. A krypton-fluoride laser (λ= 248 nm) that incorporates beam smoothing by induced spatial incoherence has the ability to produce a high quality focal profile whose diameter varies with time, a property known as focal zooming. A two-stage focal zoom has been demonstrated on the Nike laser at the Naval Research Laboratory. In the experiment, a 4.4 ns laser pulse was created in which the on-target focal spot diameter was 1.3 mm (full width at half maximum) for the first 2.4 ns and 0.28 mm for the final 2 ns. These two diameters appear in time-integrated focal plane equivalent images taken at several locations in the amplification chain. Eight of the zoomed output beams were overlapped on a 60 μm thick planar polystyrene target. Time resolved images of self-emission from the rear of the target show the separate shocks launched by the two corresponding laser focal diameters.

  8. Implementation of focal zooming on the Nike KrF laser

    Science.gov (United States)

    Kehne, D. M.; Karasik, M.; Aglitsky, Y.; Smyth, Z.; Terrell, S.; Weaver, J. L.; Chan, Y.; Lehmberg, R. H.; Obenschain, S. P.

    2013-01-01

    In direct drive inertial confinement laser fusion, a pellet containing D-T fuel is imploded by ablation arising from absorption of laser energy at its outer surface. For optimal coupling, the focal spot of the laser would continuously decrease to match the reduction in the pellet's diameter, thereby minimizing wasted energy. A krypton-fluoride laser (λ = 248 nm) that incorporates beam smoothing by induced spatial incoherence has the ability to produce a high quality focal profile whose diameter varies with time, a property known as focal zooming. A two-stage focal zoom has been demonstrated on the Nike laser at the Naval Research Laboratory. In the experiment, a 4.4 ns laser pulse was created in which the on-target focal spot diameter was 1.3 mm (full width at half maximum) for the first 2.4 ns and 0.28 mm for the final 2 ns. These two diameters appear in time-integrated focal plane equivalent images taken at several locations in the amplification chain. Eight of the zoomed output beams were overlapped on a 60 μm thick planar polystyrene target. Time resolved images of self-emission from the rear of the target show the separate shocks launched by the two corresponding laser focal diameters.

  9. Interferon Induced Focal Segmental Glomerulosclerosis

    Directory of Open Access Journals (Sweden)

    Yusuf Kayar

    2016-01-01

    Full Text Available Behçet’s disease is an inflammatory disease of unknown etiology which involves recurring oral and genital aphthous ulcers and ocular lesions as well as articular, vascular, and nervous system involvement. Focal segmental glomerulosclerosis (FSGS is usually seen in viral infections, immune deficiency syndrome, sickle cell anemia, and hyperfiltration and secondary to interferon therapy. Here, we present a case of FSGS identified with kidney biopsy in a patient who had been diagnosed with Behçet’s disease and received interferon-alpha treatment for uveitis and presented with acute renal failure and nephrotic syndrome associated with interferon.

  10. Focal nodular hyperplasia: imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Kehagias, D.; Moulopoulos, L.; Antoniou, A.; Hatziioannou, A.; Smyrniotis, V.; Trakadas, S.; Lahanis, S.; Vlahos, L. [Dept. of Radiology, University of Athens (Greece)

    2001-02-01

    Focal nodular hyperplasia is an uncommon benign hepatic tumor that continues to pose diagnostic dilemmas. Imaging techniques are of great value in diagnosis of this tumor. In this article we present the US, CT, MR imaging, scintigraphy, and angiography findings. The demonstration of a central vascular scar is very helpful. Although the radiologic features may be diagnostic, many atypical cases must be differentiated from other benign or malignant hepatic tumors. In these cases excisional biopsy and histopathologic examination are necessary to determine a definite diagnosis. (orig.)

  11. Focal nodular hyperplasia: imaging findings

    International Nuclear Information System (INIS)

    Kehagias, D.; Moulopoulos, L.; Antoniou, A.; Hatziioannou, A.; Smyrniotis, V.; Trakadas, S.; Lahanis, S.; Vlahos, L.

    2001-01-01

    Focal nodular hyperplasia is an uncommon benign hepatic tumor that continues to pose diagnostic dilemmas. Imaging techniques are of great value in diagnosis of this tumor. In this article we present the US, CT, MR imaging, scintigraphy, and angiography findings. The demonstration of a central vascular scar is very helpful. Although the radiologic features may be diagnostic, many atypical cases must be differentiated from other benign or malignant hepatic tumors. In these cases excisional biopsy and histopathologic examination are necessary to determine a definite diagnosis. (orig.)

  12. MRI of focal cortical dysplasia

    International Nuclear Information System (INIS)

    Lee, B.C.P.; Hatfield, G.A.; Bourgeois, B.; Park, T.S.

    1998-01-01

    We studied nine cases of focal cortical dysplasia (FCD) by MRI, with surface-rendered 3D reconstructions. One case was also examined using single-voxel proton MR spectroscopy (MRS). The histological features were reviewed and correlated with the MRI findings. The gyri affected by FCD were enlarged and the signal of the cortex was slightly increased on T1-weighted images. The gray-white junction was indistinct. Signal from the subcortical white matter was decreased on T1- and increased on T2-weighted images in most cases. Contrast enhancement was seen in two cases. Proton MRS showed a spectrum identical to that of normal brain. (orig.) (orig.)

  13. Mutations in X-linked PORCN, a putative regulator of Wnt signaling, cause focal dermal hypoplasia

    Science.gov (United States)

    Focal dermal hypoplasia is an X-linked dominant disorder characterized by patchy hypoplastic skin and digital, ocular, and dental malformations. We used array comparative genomic hybridization to identify a 219-kb deletion in Xp11.23 in two affected females. We sequenced genes in this region and fou...

  14. Expression of tumor necrosis factor alpha after focal cerebral ischaemia in the rat

    NARCIS (Netherlands)

    Buttini, M; Appel, K; Sauter, A; GebickeHaerter, PJ; Boddeke, HWGM

    Induction of tumor necrosis factor alpha was studied in the brain of rats after focal cerebral ischaemia by occlusion of the left middle cerebral artery. Using a specific antisense riboprobe for in situ hybridization histochemistry, cells positive for tumor necrosis factor alpha messenger RNA were

  15. Induction of interleukin-1β mRNA after focal cerebral ischaemia in the rat

    NARCIS (Netherlands)

    Buttini, M.; Sauter, A.; Boddeke, H.W.G.M.

    1994-01-01

    The expression of interleukin-1β (IL-1β) mRNA in the brain in response to cerebral ischaemia in rats was examined using in situ hybridization histochemistry. Focal cerebral ischaemia was induced in spontaneously hypertensive rats by permanent occlusion of the left middle cerebral artery (MCAO).

  16. INDUCTION OF INTERLEUKIN-1-BETA MESSENGER-RNA AFTER FOCAL CEREBRAL-ISCHEMIA IN THE RAT

    NARCIS (Netherlands)

    BUTTINI, M; SAUTER, A; BODDEKE, HWGM

    The expression of interleukin-1beta (IL-1beta) mRNA in the brain in response to cerebral ischaemia in rats was examined using in situ hybridization histochemistry. Focal cerebral ischaemia was induced in spontaneously hypertensive rats by permanent occlusion of the left middle cerebral artery

  17. The Off-plane Grating Rocket Experiment

    Science.gov (United States)

    Donovan, Benjamin

    2018-01-01

    The next generation of X-ray spectrometers necessitate significant increases in both resolution and effective area to achieve the science goals set forth in the 2010 Decadal Survey and the 2013 Astrophysics Roadmap. The Off-plane Grating Rocket Experiment (OGRE), an X-ray spectroscopy suborbital rocket payload currently scheduled for launch in Q3 2020, will serve as a testbed for several key technologies which can help achieve the desired performance increases of future spectrometers. OGRE will be the first instrument to fly mono-crystalline silicon X-ray mirrors developed at NASA Goddard Space Flight Center. The payload will also utilize an array of off-plane gratings manufactured at The Pennsylvania State University. Additionally, the focal plane will be populated with an array of four electron-multiplying CCDs developed by the Open University and XCAM Ltd. With these key technologies, OGRE hopes to achieve the highest resolution on-sky soft X-ray spectrum to date. We discuss the optical design, expected performance, and the current status of the payload.

  18. The OBS control plane

    DEFF Research Database (Denmark)

    Manolova, Anna Vasileva; Ruepp, Sarah Renée

    2010-01-01

    . The applicability analysis carried out here focuses on the actual feasibility of the integration and the potential trade-offs which appear when two contradicting principles are combined. Taking advantage of the flexibility of the GMPLS control plane does not seem to be as easy and as straightforward as expected...

  19. Pathogenesis of Focal Segmental Glomerulosclerosis

    Directory of Open Access Journals (Sweden)

    Beom Jin Lim

    2016-11-01

    Full Text Available Focal segmental glomerulosclerosis (FSGS is characterized by focal and segmental obliteration of glomerular capillary tufts with increased matrix. FSGS is classified as collapsing, tip, cellular, perihilar and not otherwise specified variants according to the location and character of the sclerotic lesion. Primary or idiopathic FSGS is considered to be related to podocyte injury, and the pathogenesis of podocyte injury has been actively investigated. Several circulating factors affecting podocyte permeability barrier have been proposed, but not proven to cause FSGS. FSGS may also be caused by genetic alterations. These genes are mainly those regulating slit diaphragm structure, actin cytoskeleton of podocytes, and foot process structure. The mode of inheritance and age of onset are different according to the gene involved. Recently, the role of parietal epithelial cells (PECs has been highlighted. Podocytes and PECs have common mesenchymal progenitors, therefore, PECs could be a source of podocyte repopulation after podocyte injury. Activated PECs migrate along adhesion to the glomerular tuft and may also contribute to the progression of sclerosis. Markers of activated PECs, including CD44, could be used to distinguish FSGS from minimal change disease. The pathogenesis of FSGS is very complex; however, understanding basic mechanisms of podocyte injury is important not only for basic research, but also for daily diagnostic pathology practice.

  20. Improved image quality for asymmetric double-focal cone-beam SPECT

    International Nuclear Information System (INIS)

    Cao, Z.J.; Tsui, B.M.W.

    1993-01-01

    To optimize both spatial resolution and detection efficiency in brain SPECT imaging using a rectangular camera, an asymmetric double-focal cone-beam collimator is proposed with the focal points located near the base plane of the patient's head. To fit the entire head into the field-of-view of the collimator with dimensions of 50cmx40cm and at a radius-of-rotation of 15 cm, the focal lengths of the collimator are 55 and 70 cm, respectively, in the transverse and axial directions. With this geometry, the artifacts in the reconstructed image produced by the Feldkamp algorithm are more severe compared to those in a symmetric cone-beam geometry, due to the larger vertex angle between the top of the head and the base plane. To improve the reconstructed image quality, a fully three-dimensional (3D) reconstruction algorithm developed previously for single-focal cone-beam SPECT was extended to the asymmetric double-focal cone-beam geometry. The algorithm involves nonstationary 2D filtering and a reprojection technique for estimation of the missing data caused by a single-orbit cone-beam geometry. The results from simulation studies with the 3D Defrise slab phantom demonstrated that the fully 3D algorithm provided a much improved image quality in terms of reduced slice-to-slice cross talks and shape elongation compared to that produced by the conventional Feldkamp algorithm

  1. RTG diagnostics of dental focal infection

    International Nuclear Information System (INIS)

    Petrasova, A.; Ondrasovicova, J.; Cecctkova, A.

    2008-01-01

    The theory of focal infection has always been and still is a controversial issue for many dentists and scientists. Even though the focal infection does not occupy the first place in modern medicine, its understanding is imperative. The authors summarized the knowledge about dental focal infection and its relationship to systemic the diseases of the whole body in their publication and they also focused on the radiodiagnostics of this disease. (authors)

  2. Periodontitis in patients with focal tuberculosis

    Directory of Open Access Journals (Sweden)

    Alexandrova Е.А.

    2010-12-01

    Full Text Available The research goal is to investigate the mechanisms of formation and peculiarities of periodontitis in patients with focal tuberculosis. Patients with periodontitis and focal tuberculosis are proved to develop local inflammatory reaction with increased infection and activation of proinflammatory cytokines in parodontal pockets fluid. The main risk factor of frequent and durable recurrence of parodontal pathology in case of focal tuberculosis was the development of pathologic process as a cause of disbalance of lipid peroxidation and antioxidant system, endotoxicosis syndrome

  3. BKP plane partitions

    International Nuclear Information System (INIS)

    Foda, Omar; Wheeler, Michael

    2007-01-01

    Using BKP neutral fermions, we derive a product expression for the generating function of volume-weighted plane partitions that satisfy two conditions. If we call a set of adjacent equal height-h columns, h > 0, an h-path, then 1. Every h-path can assume one of two possible colours. 2. There is a unique way to move along an h-path from any column to another

  4. BKP plane partitions

    Energy Technology Data Exchange (ETDEWEB)

    Foda, Omar; Wheeler, Michael [Department of Mathematics and Statistics, University of Melbourne, Parkville, Victoria 3010 (Australia)

    2007-01-15

    Using BKP neutral fermions, we derive a product expression for the generating function of volume-weighted plane partitions that satisfy two conditions. If we call a set of adjacent equal height-h columns, h > 0, an h-path, then 1. Every h-path can assume one of two possible colours. 2. There is a unique way to move along an h-path from any column to another.

  5. Carbon nanotube plane fastener

    Directory of Open Access Journals (Sweden)

    Kaori Hirahara

    2011-12-01

    Full Text Available We report a feature of carbon nanotubes (CNTs that arises when the surfaces of two vertically-aligned CNT brushes are pressed together. Adhesion between the CNTs creates a plane fastener-like device. Observations from scanning electron microscopy and measurements of adhesion properties indicate a device-dependence on CNT density and shape near the tip region. Among other applications, such fasteners have the potential to attach small components onto micron-sized electronic devices.

  6. Conquest of the Plane

    OpenAIRE

    Colignatus, Thomas

    2011-01-01

    CONQUEST OF THE PLANE provides: an integrated course for geometry and analysis a didactic build-up that avoids traditional clutter use of only the essentials for good understanding proper place for vectors, complex numbers, linear algebra and trigonometry an original and elegant development of trigonometry an original and elegant foundation for calculus examples from physics, economics and statistics integration within the dynamic environment of Mathematica ...

  7. Game Movement as Enactive Focalization

    Directory of Open Access Journals (Sweden)

    Yotam Shibolet

    2018-01-01

    Full Text Available This paper integrates thought on game narrative and embodied cognition, in order to consider the significance of movement to the embodied narrative experience of games. If games are a mode of ‘environmental storytelling’, determining the player’s mobile situatedness within the gamespace is of crucial importance. The metaphor of game design as narrative architecture should be expanded to include te the design of movement dynamics, alongside geographical gamespace. I suggest a theoretical infrastructure that aims to enable further analysis of movement design’s role in this scope. The theory of enactive perception asserts that all perception is inherently negotiated through embodied understanding of moving within environment. According to this model, by giving meaning to perception, movement is also directly related to the structure of consciousness and thought. Cognitive definitions of ‘narrative’ that integrate embodiment are applied to argue it can relevantly account for part of thought’s role in enactive perception. Mieke Bal’s concept of focalization (1997 broaches narrative perspective by underscoring the constant “movement of the look”. For enactive perception, such mobility should be understood as inseparable from the movement of the body even when perspective could appear detached from embodiment. Therefore, I offer the supplementary concept of “enactive focalization” – narrative perception as interpreted through the interconnected dynamics or perspectival and physical movement. To exemplify my ideas and the potential of future research in this scope, I discuss the uniquely effective and affective movement dynamic design of Journey. This paper concludes by reflecting on enactive focalization in light of the increased utilization of embodiment in the contemporary digital media landscape.

  8. An Algorithm for constructing Hjelmslev planes

    OpenAIRE

    Hall, Joanne L.; Rao, Asha

    2013-01-01

    Projective Hjelmslev planes and Affine Hjelmselv planes are generalisations of projective planes and affine planes. We present an algorithm for constructing a projective Hjelmslev planes and affine Hjelsmelv planes using projective planes, affine planes and orthogonal arrays. We show that all 2-uniform projective Hjelmslev planes, and all 2-uniform affine Hjelsmelv planes can be constructed in this way. As a corollary it is shown that all 2-uniform Affine Hjelmselv planes are sub-geometries o...

  9. Simultaneous orthogonal plane imaging.

    Science.gov (United States)

    Mickevicius, Nikolai J; Paulson, Eric S

    2017-11-01

    Intrafraction motion can result in a smearing of planned external beam radiation therapy dose distributions, resulting in an uncertainty in dose actually deposited in tissue. The purpose of this paper is to present a pulse sequence that is capable of imaging a moving target at a high frame rate in two orthogonal planes simultaneously for MR-guided radiotherapy. By balancing the zero gradient moment on all axes, slices in two orthogonal planes may be spatially encoded simultaneously. The orthogonal slice groups may be acquired with equal or nonequal echo times. A Cartesian spoiled gradient echo simultaneous orthogonal plane imaging (SOPI) sequence was tested in phantom and in vivo. Multiplexed SOPI acquisitions were performed in which two parallel slices were imaged along two orthogonal axes simultaneously. An autocalibrating phase-constrained 2D-SENSE-GRAPPA (generalized autocalibrating partially parallel acquisition) algorithm was implemented to reconstruct the multiplexed data. SOPI images without intraslice motion artifacts were reconstructed at a maximum frame rate of 8.16 Hz. The 2D-SENSE-GRAPPA reconstruction separated the parallel slices aliased along each orthogonal axis. The high spatiotemporal resolution provided by SOPI has the potential to be beneficial for intrafraction motion management during MR-guided radiation therapy or other MRI-guided interventions. Magn Reson Med 78:1700-1710, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  10. Prenatal sonographic diagnosis of focal musculoskeletal anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Jung Kyu; Cho, Jeong Yeon; Lee, Young Ho; Kim, Ei Jeong; Chun, Yi Kyeong [Samsung Cheil Hospital, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2002-09-15

    Focal musculoskeletal anomalies are various and may be an isolated finding or may be found in conjunction with numerous associations, including genetic syndromes, Karyotype abnormals, central nervous system anomalies and other general musculoskeletal disorders. Early prenatal diagnosis of these focal musculoskeletal anomalies nor only affects prenatal care and postnatal outcome but also helps in approaching other numerous associated anomalies.

  11. Prenatal sonographic diagnosis of focal musculoskeletal anomalies

    International Nuclear Information System (INIS)

    Ryu, Jung Kyu; Cho, Jeong Yeon; Lee, Young Ho; Kim, Ei Jeong; Chun, Yi Kyeong

    2002-01-01

    Focal musculoskeletal anomalies are various and may be an isolated finding or may be found in conjunction with numerous associations, including genetic syndromes, Karyotype abnormals, central nervous system anomalies and other general musculoskeletal disorders. Early prenatal diagnosis of these focal musculoskeletal anomalies nor only affects prenatal care and postnatal outcome but also helps in approaching other numerous associated anomalies.

  12. Plane partition vesicles

    International Nuclear Information System (INIS)

    Rensburg, E J Janse van; Ma, J

    2006-01-01

    We examine partitions and their natural three-dimensional generalizations, plane partitions, as models of vesicles undergoing an inflation-deflation transition. The phase diagrams of these models include a critical point corresponding to an inflation-deflation transition, and exhibits multicritical scaling in the vicinity of a multicritical point located elsewhere on the critical curve. We determine the locations of the multicritical points by analysing the generating functions using analytic and numerical means. In addition, we determine the numerical values of the multicritical scaling exponents associated with the multicritical scaling regimes in these models

  13. Early vision and focal attention

    Science.gov (United States)

    Julesz, Bela

    1991-07-01

    At the thirty-year anniversary of the introduction of the technique of computer-generated random-dot stereograms and random-dot cinematograms into psychology, the impact of the technique on brain research and on the study of artificial intelligence is reviewed. The main finding-that stereoscopic depth perception (stereopsis), motion perception, and preattentive texture discrimination are basically bottom-up processes, which occur without the help of the top-down processes of cognition and semantic memory-greatly simplifies the study of these processes of early vision and permits the linking of human perception with monkey neurophysiology. Particularly interesting are the unexpected findings that stereopsis (assumed to be local) is a global process, while texture discrimination (assumed to be a global process, governed by statistics) is local, based on some conspicuous local features (textons). It is shown that the top-down process of "shape (depth) from shading" does not affect stereopsis, and some of the models of machine vision are evaluated. The asymmetry effect of human texture discrimination is discussed, together with recent nonlinear spatial filter models and a novel extension of the texton theory that can cope with the asymmetry problem. This didactic review attempts to introduce the physicist to the field of psychobiology and its problems-including metascientific problems of brain research, problems of scientific creativity, the state of artificial intelligence research (including connectionist neural networks) aimed at modeling brain activity, and the fundamental role of focal attention in mental events.

  14. Hybrid active pixel sensors in infrared astronomy

    International Nuclear Information System (INIS)

    Finger, Gert; Dorn, Reinhold J.; Meyer, Manfred; Mehrgan, Leander; Stegmeier, Joerg; Moorwood, Alan

    2005-01-01

    Infrared astronomy is currently benefiting from three main technologies providing high-performance hybrid active pixel sensors. In the near infrared from 1 to 5 μm two technologies, both aiming for buttable 2Kx2K mosaics, are competing, namely InSb and HgCdTe grown by LPE or MBE on Al 2 O 3 , Si or CdZnTe substrates. Blocked impurity band Si:As arrays cover the mid infrared spectral range from 8 to 28 μm. Adaptive optics combined with multiple integral field units feeding high-resolution spectrographs drive the requirements for the array format of infrared sensors used at ground-based infrared observatories. The pixel performance is now approaching fundamental limits. In view of this development, a detection limit for the photon flux of the ideal detector will be derived, depending only on the temperature and the impedance of the detector. It will be shown that this limit is approximated by state of the art infrared arrays for long on-chip integrations. Different detector materials are compared and strategies to populate large focal planes are discussed. The need for the development of small-format low noise sensors for adaptive optics and interferometry will be pointed out

  15. Experimental research on energy circled fraction of continuous phase plates in focal spot

    International Nuclear Information System (INIS)

    Zhang Yuanhang; Yang Chunlin; Wen Shenglin; Shi Qikai; Wang Jian

    2013-01-01

    In inertial confinement fusion (ICF) research process, the form of focal spot is extremely crucial. Especially in the indirect driven implosion, energy circled fraction is higher than 95% in focal spot. Based on the offline test platform, the focusing spot of continuous phase plates with different application error is clearly imaged on CCD. By experimental analysis, it is found that the beam rotation error, caliber error, translational error and inclination error have a high tolerance in affecting focal plane of CPP. Energy circled fraction is higher than 95%, the range is less than 0.5%. Nevertheless, the waterfront aberration seriously affects the shaping ability of the CPP. Clearly, the main factor of reducing energy circled fraction to less than 90% is waterfront aberration. (authors)

  16. Duality and noncommutative planes

    DEFF Research Database (Denmark)

    Jøndrup, Søren

    2015-01-01

    We study extensions of simple modules over an associative ring A   and we prove that for twosided ideals mm and nn with artinian factors the condition ExtA1(A/m,A/n)≠0 holds for the left A  -modules A/mA/m and A/nA/n if and only if it holds for the right modules A/nA/n and A/mA/m. The methods pro...... proving this are applied to show that noncommutative models of the plane, i.e. algebras of the form k〈x,y〉/(f)k〈x,y〉/(f), where f∈([x,y])f∈([x,y]) are noetherian only in case (f)=([x,y])...

  17. Conical refraction and formation of multiring focal image with Laguerre-Gauss light beams.

    Science.gov (United States)

    Peet, Viktor

    2011-08-01

    For a light beam focused through a biaxial crystal along one of its optical axes, the effect of internal conical refraction in the crystal leads to the formation in the focal image plane of two bright rings separated by a dark ring. It is shown that, with circularly polarized Laguerre-Gauss LG(0)(ℓ) beams entering the crystal, this classical double-ring pattern is transformed into a multiring one consisting of ℓ+2 bright rings. © 2011 Optical Society of America

  18. Comparison of different approaches to the numerical calculation of the LMJ focal

    Directory of Open Access Journals (Sweden)

    Bourgeade A.

    2013-11-01

    Full Text Available The beam smoothing in the focal plane of high power lasers is of particular importance to laser-plasma interaction studies in order to minimize plasma parametric and hydrodynamic instabilities on the target. Here we investigate the focal spot structure in different geometrical configurations where standard paraxial hypotheses are no longer verified. We present numerical studies in the cases of single flat top square beam, LMJ quadruplet and complete ring of quads with large azimuth angle. Different calculations are made with Fresnel diffraction propagation model in the paraxial approximation and full vector Maxwell's equations. The first model is based on Fourier transform from near to far field method. The second model uses first spherical wave decomposition in plane waves with Fourier transform and propagates them to the focal spot. These two different approaches are compared with Miró [1] modeling results using paraxial or Feit and Fleck options. The methods presented here are generic for focal spot calculations. They can be used for other complex geometric configurations and various smoothing techniques. The results will be used as boundary conditions in plasma interaction computations.

  19. Do focal colors look particularly "colorful"?

    Science.gov (United States)

    Witzel, Christoph; Franklin, Anna

    2014-04-01

    If the most typical red, yellow, green, and blue were particularly colorful (i.e., saturated), they would "jump out to the eye." This would explain why even fundamentally different languages have distinct color terms for these focal colors, and why unique hues play a prominent role in subjective color appearance. In this study, the subjective saturation of 10 colors around each of these focal colors was measured through a pairwise matching task. Results show that subjective saturation changes systematically across hues in a way that is strongly correlated to the visual gamut, and exponentially related to sensitivity but not to focal colors.

  20. Focal Plane Detectors for the Advanced Gamma-Ray Imaging System (AGIS)

    Science.gov (United States)

    Wagner, R. G.; Byrum, K.; Drake, G.; Funk, S.; Otte, N.; Smith, A.; Tajima, H.; Williams, D.

    2009-05-01

    The Advanced Gamma-Ray Imaging System (AGIS) is a concept for the next generation observatory in ground-based very high energy gamma-ray astronomy. It is being designed to achieve a significant improvement in sensitivity compared to current Imaging Air Cherenkov Telescope (IACT) Arrays. One of the main requirements in order that AGIS fulfills this goal will be to achieve higher angular resolution than current IACTs. Simulations show that a substantial improvement in angular resolution may be achieved if the pixel size is reduced to 0.05 deg, i.e. two to three times smaller than for current IACT cameras. Here we present results from testing of alternatives being considered for AGIS, including both silicon photomultipliers (SiPMs) and multi-anode photomultipliers (MAPMTs).

  1. Low-Light-Level InGaAs focal plane arrays with and without illumination

    Science.gov (United States)

    Macdougal, Michael; Geske, Jon; Wang, Chad; Follman, David

    2010-04-01

    Short wavelength IR imaging using InGaAs-based FPAs is shown. Aerius demonstrates low dark current in InGaAs detector arrays with 15 μm pixel pitch. The same material is mated with a 640x 512 CTIA-based readout integrated circuit. The resulting FPA is capable of imaging photon fluxes with wavelengths between 1 and 1.6 microns at low light levels. The mean dark current density on the FPAs is extremely low at 0.64 nA/cm2 at 10°C. Noise due to the readout can be reduced from 95 to 57 electrons by using off-chip correlated double sampling (CDS). In addition, Aerius has developed laser arrays that provide flat illumination in scenes that are normally light-starved. The illuminators have 40% wall-plug efficiency and provide speckle-free illumination, provide artifact-free imagery versus conventional laser illuminators.

  2. A three-cell liquid hydrogen target for an extended focal plane polarimeter

    International Nuclear Information System (INIS)

    Golovanov, L.B.; Borzounov, Yu.T.; Piskunov, N.M.; Tsvinev, A.P.

    1996-01-01

    This article describes the design and working principle of a 3-cell liquid hydrogen target produced for the high-energy deuteron polarimeter HYPOM. This target uses liquid Helium as a cooling agent. After a general description of the apparatus, tests and operating modes are thoroughly explained. In particular the air controlled self regulation of Helium flow in the cryostat to stabilize the liquid hydrogen level is presented. (author)

  3. Uncooled High-Performance InAsSb Focal Plane Arrays, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — SVT Associates proposes an innovative digital alloy technique to extend the cutoff wavelength of InAsSb beyond 5 um, a wider band gap InAlAsSb layer inserted into...

  4. InGaAs focal plane array developments at III-V Lab

    Science.gov (United States)

    Rouvié, Anne; Reverchon, Jean-Luc; Huet, Odile; Djedidi, Anis; Robo, Jean-Alexandre; Truffer, Jean-Patrick; Bria, Toufiq; Pires, Mauricio; Decobert, Jean; Costard, Eric

    2012-06-01

    SWIR detection band benefits from natural (sun, night glow, thermal radiation) or artificial (eye safe lasers) photons sources combined to low atmospheric absorption and specific contrast compared to visible wavelengths. It gives the opportunity to address a large spectrum of applications such as defense and security (night vision, active imaging), space (earth observation), transport (automotive safety) or industry (non destructive process control). InGaAs material appears as a good candidate to satisfy SWIR detection needs. The lattice matching with InP constitutes a double advantage to this material: attractive production capacity and uncooled operation thanks to low dark current level induced by high quality material. For few years, III-VLab has been studying InGaAs imagery, gathering expertise in InGaAs material growth and imaging technology respectively from Alcatel-Lucent and Thales, its two mother companies. This work has lead to put quickly on the market a 320x256 InGaAs module, exhibiting high performances in terms of dark current, uniformity and quantum efficiency. In this paper, we present the last developments achieved in our laboratory, mainly focused on increasing the pixels number to VGA format associated to pixel pitch decrease (15μm) and broadening detection spectrum toward visible wavelengths. Depending on targeted applications, different Read Out Integrated Circuits (ROIC) have been used. Low noise ROIC have been developed by CEA LETI to fit the requirements of low light level imaging whereas logarithmic ROIC designed by NIT allows high dynamic imaging adapted for automotive safety.

  5. Focal Plane Development for the Transition-Edge EBIT Microcalorimeter Spectrometer

    Data.gov (United States)

    National Aeronautics and Space Administration — I propose to produce the first fully operational 1000-pixel X-ray Transition-Edge Sensor microcalorimeter imaging spectrometer system, and to deliver it to the...

  6. In-focal-plane characterization of excitation distribution for quantitative fluorescence microscopy applications

    Science.gov (United States)

    Dietrich, Klaus; Brülisauer, Martina; ćaǧin, Emine; Bertsch, Dietmar; Lüthi, Stefan; Heeb, Peter; Stärker, Ulrich; Bernard, André

    2017-06-01

    The applications of fluorescence microscopy span medical diagnostics, bioengineering and biomaterial analytics. Full exploitation of fluorescent microscopy is hampered by imperfections in illumination, detection and filtering. Mainly, errors stem from deviations induced by real-world components inducing spatial or angular variations of propagation properties along the optical path, and they can be addressed through consistent and accurate calibration. For many applications, uniform signal to noise ratio (SNR) over the imaging area is required. Homogeneous SNR can be achieved by quantifying and compensating for the signal bias. We present a method to quantitatively characterize novel reference materials as a calibration reference for biomaterials analytics. The reference materials under investigation comprise thin layers of fluorophores embedded in polymer matrices. These layers are highly homogeneous in their fluorescence response, where cumulative variations do not exceed 1% over the field of view (1.5 x 1.1 mm). An automated and reproducible measurement methodology, enabling sufficient correction for measurement artefacts, is reported. The measurement setup is equipped with an autofocus system, ensuring that the measured film quality is not artificially increased by out-of-focus reduction of the system modulation transfer function. The quantitative characterization method is suitable for analysis of modified bio-materials, especially through patterned protein decoration. The imaging method presented here can be used to statistically analyze protein patterns, thereby increasing both precision and throughput. Further, the method can be developed to include a reference emitter and detector pair on the image surface of the reference object, in order to provide traceable measurements.

  7. High-performance visible/UV CCD focal plane technology for spacebased applications

    Science.gov (United States)

    Burke, B. E.; Mountain, R. W.; Gregory, J. A.; Huang, J. C. M.; Cooper, M. J.; Savoye, E. D.; Kosicki, B. B.

    1993-01-01

    We describe recent technology developments aimed at large CCD imagers for space based applications in the visible and UV. Some of the principal areas of effort include work on reducing device degradation in the natural space-radiation environment, improvements in quantum efficiency in the visible and UV, and larger-device formats. One of the most serious hazards for space based CCD's operating at low signal levels is the displacement damage resulting from bombardment by energetic protons. Such damage degrades charge-transfer efficiency and increases dark current. We have achieved improved hardness to proton-induced displacement damage by selective ion implants into the CCD channel and by reduced temperature of operation. To attain high quantum efficiency across the visible and UV we have developed a technology for back-illuminated CCD's. With suitable antireflection (AR) coatings such devices have quantum efficiencies near 90 percent in the 500-700-nm band. In the UV band from 200 to 400 nm, where it is difficult to find coatings that are sufficiently transparent and can provide good matching to the high refractive index of silicon, we have been able to substantially increase the quantum efficiency using a thin film of HfO2 as an AR coating. These technology efforts were applied to a 420 x 420-pixel frame-transfer imager, and future work will be extended to a 1024 x 1024-pixel device now under development.

  8. A three-cell liquid hydrogen target for an extended focal plane polarimeter

    International Nuclear Information System (INIS)

    Golovanov, L.B.; Chesny, P.; Gheller, J.M.; Guillier, G.; Ladygin, V.P.; Theure, Ph.; Tomasi-Gustafsson, E.

    1996-01-01

    This article describes the design and working principle of a three-cell liquid hydrogen target produced for the high-energy deuteron polarimeter HYPOM. This target uses liquid helium as a cooling agent. After a general description of the apparatus, tests and operating modes are thoroughly explained. In particular the air controlled self-regulation of helium flow in the cryostat to stabilize the liquid hydrogen level is presented. The main feature of this target is the simplicity of the design as well as its safeness towards any incident. Results of cooling down, filling up of the target and stabilization regime were processed during one experiment of physics at synchrotron Saturne II. (orig.)

  9. A new isomer in 195Bi identified at the focal plane of HYRA

    International Nuclear Information System (INIS)

    Roy, T.; Mukherjee, G.; Asgar, Md. A.

    2014-01-01

    Due to the presence of high-j (h 9/2 and i 13/2 ) orbitals near the proton and neutron Fermi levels, high spin isomers are expected to occur for neutron deficient Bismuth nuclei (Z = 83) in A = 190 region. A 750 ns isomer has been known for a long time in 195 Bi whose excitation energy and decay path have been reported recently. A rotational band has been reported in this nucleus based on 13/2 + isomer, originated from the deformation driving i 13/2 orbital. This band reported to have prompt feeding through a 457 keV γ-ray apart from a strong feeding from the 750 ns isomer. In 193 Bi, the 29/2 - state is a 3μs isomer, another isomer with half-life >10μs is also known in this nucleus but its excitation energy, spin and parity are not known. Similar isomer has not yet been observed in 195 Bi. The aim of the present work was to find isomers and their decays in 193,195 Bi

  10. Megapixel mercury cadmium telluride focal plane arrays for infrared imaging out to 12 microns, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the fabrication of large format, long wave infrared (LWIR) mercury cadmium telluride (HgCdTe or MCT) detector arrays where the cutoff wavelength is...

  11. High-contrast coronagraph performance in the presence of focal plane mask defects

    Science.gov (United States)

    Sidick, Erkin; Shaklan, Stuart; Balasubramanian, Kunjithapatham; Cady, Eric

    2014-08-01

    We have carried out a study of the performance of high-contrast coronagraphs in the presence of mask defects. We have considered the effects of opaque and dielectric particles of various dimensions, as well as systematic mask fabrication errors and the limitations of material properties in creating dark holes. We employ sequential deformable mirrors to compensate for phase and amplitude errors, and show the limitations of this approach in the presence of coronagraph image-mask defects.

  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. Germanium photodetectors fabricated on 300 mm silicon wafers for near-infrared focal plane arrays

    Science.gov (United States)

    Zeller, John W.; Rouse, Caitlin; Efstathiadis, Harry; Dhar, Nibir K.; Wijewarnasuriya, Priyalal; Sood, Ashok K.

    2017-09-01

    SiGe p-i-n photodetectors have been fabricated on 300 mm (12") diameter silicon (Si) wafers utilizing high throughput, large-area complementary metal-oxide semiconductor (CMOS) technologies. These Ge photodetectors are designed to operate in room temperature environments without cooling, and thus have potential size and cost advantages over conventional cooled infrared detectors. The two-step fabrication process for the p-i-n photodetector devices, designed to minimize the formation of defects and threading dislocations, involves low temperature epitaxial growth of a thin p+ (boron) Ge seed/buffer layer, followed by higher temperature deposition of a thicker Ge intrinsic layer. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) demonstrated uniform layer compositions with well defined layer interfaces and reduced dislocation density. Time-of-flight secondary ion mass spectroscopy (TOF-SIMS) was likewise employed to analyze the doping levels of the p+ and n+ layers. Current-voltage (I-V) measurements demonstrated that these SiGe photodetectors, when exposed to incident visible-NIR radiation, exhibited dark currents down below 1 μA and significant enhancement in photocurrent at -1 V. The zero-bias photocurrent was also relatively high, showing a minimal drop compared to that at -1 V bias.

  14. High Sensitivity Indium Phosphide Based Avalanche Photodiode Focal Plane Arrays, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — nLight has demonstrated highly-uniform APD arrays based on the highly sensitive InGaAs/InP material system. These results provide great promise for achieving the...

  15. Military Applications of Curved Focal Plane Arrays Developed by the HARDI Program

    Science.gov (United States)

    2011-01-01

    considered one of the main founders of geometrical optics, modern photography, and cinematography . Among his inventions are the Petzval portrait lens...still be a problem. B. HARDI Program/Institute for Defense Analyses (IDA) Task 1. HARDI Program State-of-the- art cameras could be improved by

  16. MIS photodetectors on intrinsic semiconductors for thermal infrared imagery - A design aid for focal plane matrices

    Science.gov (United States)

    Farre, J.

    1980-12-01

    The physical mechanisms determining the operational behavior of an MIS photodetector for thermal infrared imagery based on a two-dimensional matrix of intrinsic semiconductors constituting a charge injection device are examined. The general principles of a thermal infrared imagery system composed of radiation source, atmosphere, sensor system with entrance optics, detector and environment, and data processing means are introduced, and the parameters of the system as a whole influencing detector characteristics are indicated. The properties of an ideal and a real MIS photodetector are discussed, with attention given to the physical properties of narrow bandgap materials such as InSb, operational properties in the dynamic regime, the carrier tunneling component and experimentally observed instability phenomena. The matrix organization of MIS photodetectors is then considered, with particular attention given to a simple model of charge transfer between two electrodes and the two principal reading mechanisms: charge injection and the floating potential method.

  17. Development of HgCdSe for Third Generation Focal Plane Arrays using Molecular Beam Epitaxy

    Science.gov (United States)

    2013-08-01

    29 Figure 2-9: BEP measured from Se cracker for different cracking zone temperatures, with Se...80 Figure 5-1: Growth Rate vs. estimated substrate temperature for both Se sources, with a fixed set of source BEPs ...87 Figure 5-2: Growth Rate vs. Se BEP for Hg1

  18. Focal skin defect, limb anomalies and microphthalmia.

    NARCIS (Netherlands)

    Jackson, K.E.; Andersson, H.C.

    2004-01-01

    We describe two unrelated female patients with congenital single focal skin defects, unilateral microphthalmia and limb anomalies. Growth and psychomotor development were normal and no brain malformation was detected. Although eye and limb anomalies are commonly associated, clinical anophthalmia and

  19. Focal adhesions and cell-matrix interactions

    DEFF Research Database (Denmark)

    Woods, A; Couchman, J R

    1988-01-01

    Focal adhesions are areas of cell surfaces where specializations of cytoskeletal, membrane and extracellular components combine to produce stable cell-matrix interactions. The morphology of these adhesions and the components identified in them are discussed together with possible mechanisms...

  20. Genetics Home Reference: focal dermal hypoplasia

    Science.gov (United States)

    ... in people with focal dermal hypoplasia is an omphalocele , which is an opening in the wall of ... Dermal Hypoplasia MedlinePlus Encyclopedia: Ectodermal dysplasia MedlinePlus Encyclopedia: Omphalocele General Information from MedlinePlus (5 links) Diagnostic Tests ...

  1. Focal lesions in the central nervous system

    International Nuclear Information System (INIS)

    Fabrikant, J.I.; Budinger, T.F.; Tobias, C.A.; Born, J.L.

    1980-01-01

    This report reviews the animal and human studies currently in progress at LBL with heavy-ion beams to induce focal lesions in the central nervous system, and discusses the potential future prospects of fundamental and applied brain research with heavy-ion beams. Methods are being developed for producing discrete focal lesions in the central nervous system using the Bragg ionization peak to investigate nerve pathways and neuroendocrine responses, and for treating pathological disorders of the brain

  2. Application of oblique plane microscopy to high speed live cell imaging

    Science.gov (United States)

    Kumar, Sunil; Wilding, Dean; Sikkel, Markus B.; Lyon, Alexander R.; MacLeod, Ken T.; Dunsby, Chris

    2011-07-01

    Oblique Plane Microscopy (OPM) is a light sheet microscopy technique that combines oblique illumination with correction optics that tilt the focal plane of the collection system. OPM can be used to image conventionally mounted specimens on coverslips or tissue culture dishes and has low out-of-plane photobleaching and phototoxicity. No moving parts are required to achieve an optically sectioned image and so high speed optically sectioned imaging is possible. We present high speed 2D and 3D optically sectioned OPM imaging of live cells using a high NA water immersion lens.

  3. Semantic Versus Syntactic Cutting Planes

    OpenAIRE

    Filmus, Yuval; Hrubeš, Pavel; Lauria, Massimo

    2016-01-01

    In this paper, we compare the strength of the semantic and syntactic version of the cutting planes proof system. First, we show that the lower bound technique of Pudlák applies also to semantic cutting planes: the proof system has feasible interpolation via monotone real circuits, which gives an exponential lower bound on lengths of semantic cutting planes refutations. Second, we show that semantic refutations are stronger than syntactic ones. In particular, we give a formula for whic...

  4. Sighting optics including an optical element having a first focal length and a second focal length

    Science.gov (United States)

    Crandall, David Lynn [Idaho Falls, ID

    2011-08-01

    One embodiment of sighting optics according to the teachings provided herein may include a front sight and a rear sight positioned in spaced-apart relation. The rear sight includes an optical element having a first focal length and a second focal length. The first focal length is selected so that it is about equal to a distance separating the optical element and the front sight and the second focal length is selected so that it is about equal to a target distance. The optical element thus brings into simultaneous focus, for a user, images of the front sight and the target.

  5. Gravitational Couplings for Gop-Planes and y-Op-Planes

    OpenAIRE

    Giraldo, Juan Fernando Ospina

    2000-01-01

    The Wess-Zumino actions for generalized orientifold planes (GOp-planes) and y-deformed orientifold planes (yOp-planes) are presented and two series power expantions are realized from whiches processes that involves GOp-planes,yOp-planes, RR-forms, gravitons and gaugeons, are obtained. Finally non-standard GOp-planes and y-Op-planes are showed.

  6. Transparent meta-analysis: does aging spare prospective memory with focal vs. non-focal cues?

    Directory of Open Access Journals (Sweden)

    Bob Uttl

    Full Text Available BACKGROUND: Prospective memory (ProM is the ability to become aware of a previously-formed plan at the right time and place. For over twenty years, researchers have been debating whether prospective memory declines with aging or whether it is spared by aging and, most recently, whether aging spares prospective memory with focal vs. non-focal cues. Two recent meta-analyses examining these claims did not include all relevant studies and ignored prevalent ceiling effects, age confounds, and did not distinguish between prospective memory subdomains (e.g., ProM proper, vigilance, habitual ProM (see Uttl, 2008, PLoS ONE. The present meta-analysis focuses on the following questions: Does prospective memory decline with aging? Does prospective memory with focal vs. non-focal cues decline with aging? Does the size of age-related declines with focal vs. non-focal cues vary across ProM subdomains? And are age-related declines in ProM smaller than age-related declines in retrospective memory? METHODS AND FINDINGS: A meta-analysis of event-cued ProM using data visualization and modeling, robust count methods, and conventional meta-analysis techniques revealed that first, the size of age-related declines in ProM with both focal and non-focal cues are large. Second, age-related declines in ProM with focal cues are larger in ProM proper and smaller in vigilance. Third, age-related declines in ProM proper with focal cues are as large as age-related declines in recall measures of retrospective memory. CONCLUSIONS: The results are consistent with Craik's (1983 proposal that age-related declines on ProM tasks are generally large, support the distinction between ProM proper vs. vigilance, and directly contradict widespread claims that ProM, with or without focal cues, is spared by aging.

  7. Focal thyroid inferno” on color Doppler ultrasonography: A specific feature of focal Hashimoto's thyroiditis

    International Nuclear Information System (INIS)

    Fu, Xianshui; Guo, Limei; Zhang, Huabin; Ran, Weiqiang; Fu, Peng; Li, Zhiqiang; Chen, Wen; Jiang, Ling; Wang, Jinrui; Jia, Jianwen

    2012-01-01

    Purpose: To evaluate color-Doppler features predictive of focal Hashimoto's thyroiditis. Materials and methods: A total of 521 patients with 561 thyroid nodules that underwent surgeries or gun biopsies were included in this study. These nodules were divided into three groups: focal Hashimoto's thyroiditis (104 nodules in 101 patients), benignity other than focal Hashimoto's thyroiditis (73 nodules in 70 patients), and malignancy (358 nodules in 350 patients). On color Doppler sonography, four vascularity types were determined as: hypovascularity, marked internal flow, marked peripheral flow and focal thyroid inferno. The χ 2 test was performed to seek the potential vascularity type with the predictive ability of certain thyroid pathology. Furthermore, the gray-scale features of each nodule were also studied. Results: The vascularity type I (hypovascularity) was more often seen in focal Hashimoto's thyroiditis than other benignity and malignancy (46% vs. 20.5% and 19%). While the type II (marked internal flow) showed the opposite tendency (26.9% [focal Hashimoto's thyroiditis] vs. 45.2% [other benignity] and 52.8% [malignancy]). However, type III (marked peripheral flow) was unable to predict any thyroid pathology. Importantly, type IV (focal thyroid inferno) was exclusive to focal Hashimoto's thyroiditis. All 8 type IV nodules appeared to be solid, hypoechoic, and well-defined. Using “focal thyroid inferno” as an indicator of FHT, the diagnostic sensitivity and specificity were 7.7% and 100% respectively. Conclusions: The vascularity type of “focal thyroid inferno” is specific for focal Hashimoto thyroiditis. Recognition of this particular feature may avoid unnecessary interventional procedures for some solid hypoechoic thyroid nodules suspicious of malignancy.

  8. Conceptual Design of Wave Plane

    DEFF Research Database (Denmark)

    Frigaard, Peter; Trewers, Andrew; Kofoed, Jens Peter

    The Wave Plane is a patented Wave Energy device of the overtopping type, designed to capture potential as well as kinetic energy. This is as such different to other overtopping devices, who usually only focus on potential energy. If Wave Plane A/S can deliver the turbine technology to utilize both...

  9. Fault plane solutions as related to known geological faults in and near India

    Directory of Open Access Journals (Sweden)

    N. SRIVASTAVA

    1975-05-01

    Full Text Available Based on the focal mechanism solutions of newly determined solutions, and other recent workers the correlation between one of the nodal planes and the geological faults has been discussed for three regions namely Kashmir, Central Himalayas and northeast India including Assam. The variability between multiple solutions reported for some earthquakes and the limitations in the choice of the nodal plane from /'-wave solutions have been brought out. It is seen that no standard criteria either on the basis of isoseismals or of aftershocks can be used to distinguish the fault plane from the auxiliary plane. It has been found that in general there is good agreement between one of the nodal planes and the geological faults in Kashmir and the Central Himalayas. In northeast India, the strike directions obtained from the mechanism solutions generally agree with the trends of the main thrusts but the dip direction for shocks originating in the India-Burma border

  10. Prenatal sonographic diagnosis of focal musculoskeletal anomalies

    International Nuclear Information System (INIS)

    Ryu, Jung-Kyu; Cho, Jeong-Yeon; Choi, Jong-Sun

    2003-01-01

    Focal musculoskeletal anomalies vary, and can manifest as part of a syndrome or be accompanied by numerous other conditions such as genetic disorders, karyotype abnormalities, central nervous system anomalies and other skeletal anomalies, lsolated focal musculoskeletal anomaly does, however, also occur; its early prenatal diagnosis is important in deciding prenatal care, and also helps in counseling parents about the postnatal effects of numerous possible associated anomalies. We have encountered 50 cases involving focal musculoskeletal anomalies, including total limb dysplasia [radial ray abnormality (n=3), mesomelic dysplasia (n=1)]; anomalies of the hand [polydactyly (n=8), syndactyly (n=3), ectrodactyly (n=1), clinodactyly (n=6), clenched hand (n=5)]; anomalies of the foot [clubfoot (n=10), rockerbottom foot (n=5), sandal gap deformity (n=1), curly toe (n=2)]; amniotic band syndrome (n=3); and anomalies of the focal spine [block vertebra (n=1), hemivertebra (n=1)]. Among these 50 cases, five [polydactyly (n=1), syndactyly (n=2) and curly toe (n=2) were confirmed by postnatal physical evaluation, two (focal spine anomalies) were diagnosed after postnatal radiologic examination, and the remaining 43 were proven at autopsy. For each condition, we describe the prenatal sonographic findings, and include a brief review

  11. Prenatal sonographic diagnosis of focal musculoskeletal anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Jung-Kyu; Cho, Jeong-Yeon; Choi, Jong-Sun [Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2003-12-15

    Focal musculoskeletal anomalies vary, and can manifest as part of a syndrome or be accompanied by numerous other conditions such as genetic disorders, karyotype abnormalities, central nervous system anomalies and other skeletal anomalies, lsolated focal musculoskeletal anomaly does, however, also occur; its early prenatal diagnosis is important in deciding prenatal care, and also helps in counseling parents about the postnatal effects of numerous possible associated anomalies. We have encountered 50 cases involving focal musculoskeletal anomalies, including total limb dysplasia [radial ray abnormality (n=3), mesomelic dysplasia (n=1)]; anomalies of the hand [polydactyly (n=8), syndactyly (n=3), ectrodactyly (n=1), clinodactyly (n=6), clenched hand (n=5)]; anomalies of the foot [clubfoot (n=10), rockerbottom foot (n=5), sandal gap deformity (n=1), curly toe (n=2)]; amniotic band syndrome (n=3); and anomalies of the focal spine [block vertebra (n=1), hemivertebra (n=1)]. Among these 50 cases, five [polydactyly (n=1), syndactyly (n=2) and curly toe (n=2) were confirmed by postnatal physical evaluation, two (focal spine anomalies) were diagnosed after postnatal radiologic examination, and the remaining 43 were proven at autopsy. For each condition, we describe the prenatal sonographic findings, and include a brief review.

  12. Seven tesla MRI improves detection of focal cortical dysplasia in patients with refractory focal epilepsy

    NARCIS (Netherlands)

    Veersema, Tim J; Ferrier, Cyrille H; van Eijsden, Pieter; Gosselaar, Peter H; Aronica, Eleonora; Visser, Fredy; Zwanenburg, Jaco M; de Kort, Gerard A P; Hendrikse, Jeroen; Luijten, Peter R; Braun, Kees P J

    Objective: The aim of this study is to determine whether the use of 7 tesla (T) MRI in clinical practice leads to higher detection rates of focal cortical dysplasias in possible candidates for epilepsy surgery. Methods: In our center patients are referred for 7 T MRI if lesional focal epilepsy is

  13. Hybrid Multi-Layer Network Control for Emerging Cyber-Infrastructures

    Energy Technology Data Exchange (ETDEWEB)

    Summerhill, Richard [Internet2, Washington, DC (United States); Lehman, Tom [Univ. of Southern California, Los Angeles, CA (United States). Information Sciences Inst. (ISI); Ghani, Nasir [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Electrical & Computer Engineering; Boyd, Eric [Univ. Corporation for Advanced Internet Development (UCAID), Washington, DC (United States)

    2009-08-14

    There were four basic task areas identified for the Hybrid-MLN project. They are: Multi-Layer, Multi-Domain, Control Plane Architecture and Implementation; Heterogeneous DataPlane Testing; Simulation; Project Publications, Reports, and Presentations.

  14. Expansive focal cemento-osseous dysplasia.

    Science.gov (United States)

    Bulut, Emel Uzun; Acikgoz, Aydan; Ozan, Bora; Zengin, Ayse Zeynep; Gunhan, Omer

    2012-01-01

    To present a case of expansive focal cemento-osseous dysplasia and emphasize the importance of differential diagnosis. Cemento-osseous dysplasia is categorized into three subtypes on the basis of the clinical and radiographic features: Periapical, focal and florid. The focal type exhibits a single site of involvement in any tooth-bearing or edentulous area of the jaws. These lesions are usually asymptomatic; therefore, they are frequently diagnosed incidentally during routine radiographic examinations. Lesions are usually benign, show limited growth, and do not require further surgical intervention, but periodic follow-up is recommended because occasionally, this type of dysplasia progresses into florid osseous dysplasia and simple bone cysts are formed. A 24-year-old female patient was referred to our clinic for swelling in the left edentulous mandibular premolarmolar region and felt discomfort when she wore her prosthetics. She had no pain, tenderness or paresthesia. Clinical examination showed that the swelling in the posterior mandible that was firm, nonfluctuant and covered by normal mucosa. On panoramic radiography and computed tomography, a well defined lesion of approximately 1.5 cm in diameter of mixed density was observed. The swelling increased slightly in size over 2 years making it difficult to use prosthetics and, therefore, the lesion was totally excised under local anesthesia, and surgical specimens were submitted for histopathological examination. The histopathological diagnosis was focal cemento-osseous dysplasia. In the present case, because of the increasing size of the swelling making it difficult to use prosthetics, young age of the patient and localization of the lesion, in the initial examination, cemento-ossifying fibroma was suspected, and the lesion was excised surgically; the histopathological diagnosis confirmed it as focal cemento-osseous dysplasia. We present a case of expansive focal cemento-osseous dysplasia. Differential diagnosis

  15. Extensive Focal Epithelial Hyperplasia: A Case Report.

    Science.gov (United States)

    Mansouri, Zahra; Bakhtiari, Sedigheh; Noormohamadi, Robab

    2015-01-01

    Focal epithelial hyperplasia (FEH) or Heck's disease is a rare viral infection of the oral mucosa caused by human papilloma virus especially subtypes 13 or 32. The frequency of this disease varies widely from one geographic region and ethnic groups to another. This paper reports an Iranian case of extensive focal epithelial hyperplasia. A 35-year-old man with FEH is described, in whom the lesions had persisted for more than 25 years. The lesion was diagnosed according to both clinical and histopathological features. Dental practitioner should be aware of these types of lesions and histopathological examination together and a careful clinical observation should be carried out for a definitive diagnosis.

  16. Rasmussen's encephalitis presenting as focal cortical dysplasia

    Directory of Open Access Journals (Sweden)

    D.J. O'Rourke

    2014-01-01

    Full Text Available Rasmussen's encephalitis is a rare syndrome characterized by intractable seizures, often associated with epilepsia partialis continua and symptoms of progressive hemispheric dysfunction. Seizures are usually the hallmark of presentation, but antiepileptic drug treatment fails in most patients and is ineffective against epilepsia partialis continua, which often requires surgical intervention. Co-occurrence of focal cortical dysplasia has only rarely been described and may have implications regarding pathophysiology and management. We describe a rare case of dual pathology of Rasmussen's encephalitis presenting as a focal cortical dysplasia (FCD and discuss the literature on this topic.

  17. Rasmussen's encephalitis presenting as focal cortical dysplasia

    Science.gov (United States)

    O'Rourke, D.J.; Bergin, A.; Rotenberg, A.; Peters, J.; Gorman, M.; Poduri, A.; Cryan, J.; Lidov, H.; Madsen, J.; Harini, C.

    2014-01-01

    Rasmussen's encephalitis is a rare syndrome characterized by intractable seizures, often associated with epilepsia partialis continua and symptoms of progressive hemispheric dysfunction. Seizures are usually the hallmark of presentation, but antiepileptic drug treatment fails in most patients and is ineffective against epilepsia partialis continua, which often requires surgical intervention. Co-occurrence of focal cortical dysplasia has only rarely been described and may have implications regarding pathophysiology and management. We describe a rare case of dual pathology of Rasmussen's encephalitis presenting as a focal cortical dysplasia (FCD) and discuss the literature on this topic. PMID:25667877

  18. Actinic Granuloma with Focal Segmental Glomerulosclerosis

    Directory of Open Access Journals (Sweden)

    Ruedee Phasukthaworn

    2016-02-01

    Full Text Available Actinic granuloma is an uncommon granulomatous disease, characterized by annular erythematous plaque with central clearing predominately located on sun-damaged skin. The pathogenesis is not well understood, ultraviolet radiation is recognized as precipitating factor. We report a case of a 52-year-old woman who presented with asymptomatic annular erythematous plaques on the forehead and both cheeks persisting for 2 years. The clinical presentation and histopathologic findings support the diagnosis of actinic granuloma. During that period of time, she also developed focal segmental glomerulosclerosis. The association between actinic granuloma and focal segmental glomerulosclerosis needs to be clarified by further studies.

  19. Focal splenic masses of the extramedullary hematopoiesis

    International Nuclear Information System (INIS)

    Incedayi, M.; Sivrioglu, A.

    2012-01-01

    Full text: Extramedullary hematopoiesis arises from pleuripotential stem cells distributed throughout the body. It is most common in patients with congenital hemolytic anemia, such as thalassemia, sickle cell anemia and hereditary spherocytosis as a response to ineffective red blood cell formation. Although microscopic foci of Extramedullary hematopoiesis are commonly seen in the spleen and liver parenchyma, focal mass-like lesion of extramedullary hematopoiesis in the liver and spleen are rare. We report a case of intrasplenic focal extramedullary hematopoiesis lesions and the imaging features of extramedullary hematopoiesis on computed tomography and magnetic resonance imaging. Extramedullary hematopoiesis should always be considered as a diagnosis in a patient with a known hematological disorder

  20. Motion-free hybrid design laser beam propagation analyzer using a digital micromirror device and a variable focus liquid lens.

    Science.gov (United States)

    Sheikh, Mumtaz; Riza, Nabeel A

    2010-06-01

    To the best of our knowledge, we propose the first motion-free laser beam propagation analyzer with a hybrid design using a digital micromirror device (DMD) and a liquid electronically controlled variable focus lens (ECVFL). Unlike prior analyzers that require profiling the beam at multiple locations along the light propagation axis, the proposed analyzer profiles the beam at the same plane for multiple values of the ECVFL focal length, thus eliminating beam profiler assembly motion. In addition to measuring standard Gaussian beam parameters, the analyzer can also be used to measure the M(2) beam propagation parameter of a multimode beam. Proof-of-concept beam parameter measurements with the proposed analyzer are successfully conducted for a 633 nm laser beam. Given the all-digital nature of the DMD-based profiling and all-analog motion-free nature of the ECVFL beam focus control, the proposed analyzer versus prior art promises better repeatability, speed, and reliability.

  1. 3D synthetic aperture imaging using a virtual source element in the elevation plane

    DEFF Research Database (Denmark)

    Nikolov, Svetoslav; Jensen, Jørgen Arendt

    2000-01-01

    . However, the resolution in the elevation plane is determined by the fixed mechanical elevation focus. This paper suggests to post-focus the RF lines from several adjacent planes in the elevation direction using the elevation focal point of the transducer as a virtual source element, in order to obtain...... dynamic focusing in the elevation plane. A 0.1 mm point scatterer was mounted in an agar block and scanned in a water bath. The transducer is a 64 elements linear array with a pitch of 209 μm. The transducer height is 4 mm in the elevation plane and it is focused at 20 mm giving a F-number of 5. The point...... are passed through a second beamformer, in which the fixed focal points in the elevation plane are treated as virtual sources of spherical waves. Synthetic aperture focusing is applied on them. The -6 dB resolution in the elevation plane is increased from 7 mm to 2 mm. This gives a uniform point spread...

  2. FMC: a one-liner Python program to manage, classify and plot focal mechanisms

    Science.gov (United States)

    Álvarez-Gómez, José A.

    2014-05-01

    The analysis of earthquake focal mechanisms (or Seismic Moment Tensor, SMT) is a key tool on seismotectonics research. Each focal mechanism is characterized by several location parameters of the earthquake hypocenter, the earthquake size (magnitude and scalar moment tensor) and some geometrical characteristics of the rupture (nodal planes orientations, SMT components and/or SMT main axes orientations). The aim of FMC is to provide a simple but powerful tool to manage focal mechanism data. The data should be input to the program formatted as one of two of the focal mechanisms formatting options of the GMT (Generic Mapping Tools) package (Wessel and Smith, 1998): the Harvard CMT convention and the single nodal plane Aki and Richards (1980) convention. The former is a SMT format that can be downloaded directly from the Global CMT site (http://www.globalcmt.org/), while the later is the simplest way to describe earthquake rupture data. FMC is programmed in Python language, which is distributed as Open Source GPL-compatible, and therefore can be used to develop Free Software. Python runs on almost any machine, and has a wide support and presence in any operative system. The program has been conceived with the modularity and versatility of the classical UNIX-like tools. Is called from the command line and can be easily integrated into shell scripts (*NIX systems) or batch files (DOS/Windows systems). The program input and outputs can be done by means of ASCII files or using standard input (or redirection "") and pipes ("|"). By default FMC will read the input and write the output as a Harvard CMT (psmeca formatted) ASCII file, although other formats can be used. Optionally FMC will produce a classification diagram representing the rupture type of the focal mechanisms processed. In order to count with a detailed classification of the focal mechanisms I decided to classify the focal mechanism in a series of fields that include the oblique slip regimes. This approximation

  3. Generating asymptotically plane wave spacetimes

    International Nuclear Information System (INIS)

    Hubeny, Veronika E.; Rangamani, Mukund

    2003-01-01

    In an attempt to study asymptotically plane wave spacetimes which admit an event horizon, we find solutions to vacuum Einstein's equations in arbitrary dimension which have a globally null Killing field and rotational symmetry. We show that while such solutions can be deformed to include ones which are asymptotically plane wave, they do not posses a regular event horizon. If we allow for additional matter, such as in supergravity theories, we show that it is possible to have extremal solutions with globally null Killing field, a regular horizon, and which, in addition, are asymptotically plane wave. In particular, we deform the extremal M2-brane solution in 11-dimensional supergravity so that it behaves asymptotically as a 10-dimensional vacuum plane wave times a real line. (author)

  4. Two-transitive MInkowski planes

    NARCIS (Netherlands)

    Wilbrink, H.A.

    1982-01-01

    In this paper we determine all finite Minkowski planes with an automorphism group which satisfies the following transitivity property: any ordered pair of nonparallel points can be mapped onto any other ordered pair of nonparallel points.

  5. Characterization of X-ray Lobster Optics with a Hybrid CMOS sensor

    Science.gov (United States)

    Chattopadhyay, Tanmoy; Falcone, Abraham; Burrows, David N.; Bray, Evan; McQuaide, Maria; Kern, Matthew; Wages, Mitchell; Hull, Samuel; Inneman, Adolf; Hudec, Rene; Stehlikova, Veronika

    2018-01-01

    X-ray lobster optics provide a unique way to focus X-rays onto a small focal plane imager with wide field of view imaging. Such an instrument with angular resolution of a few arcminutes can be used to study GRB afterglows, as well as the variability and spectroscopic characteristics for various astrophysical objects. At Penn State University, we have characterized a lobster optic with an H1RG X-Ray hybrid CMOS detector (100 μm thick Silicon with 18 μm pixel size). The light-weight compact lobster optic with a 25 cm focal length provides two dimensional imaging with ~25 cm2 effective area at 2 keV. We utilize a 47 meter long X-ray beam line at Penn state University to do our experiments where we characterize the overall effective area of the instrument at 1.5 - 8 keV for both on-axis and off-axis angles. In this presentation, we will describe the characterization test stand and methods, as well as the detailed results. While this is simply a proof-of-concept experiment, such an instrument with significant collecting area can be explored for future rocket or CubeSat experiments.

  6. Focal dermal hypoplasia: A rare case report

    Directory of Open Access Journals (Sweden)

    Sahana M Srinivas

    2015-01-01

    Full Text Available Focal dermal hypoplasia (Goltz syndrome is a rare genetic multisystem disorder primarily involving the skin, skeletal system, eyes, and face. We report the case of an eight-month-old female child who presented with multiple hypopigmented atrophic macules along the lines of blaschko, skeletal anomalies, umbilical hernia, developmental delay, hypoplastic nails, syndactyly, and lobster claw deformity characteristic of Goltz syndrome.

  7. On the Optimization of Aerospace Plane Ascent Trajectory

    Science.gov (United States)

    Al-Garni, Ahmed; Kassem, Ayman Hamdy

    A hybrid heuristic optimization technique based on genetic algorithms and particle swarm optimization has been developed and tested for trajectory optimization problems with multi-constraints and a multi-objective cost function. The technique is used to calculate control settings for two types for ascending trajectories (constant dynamic pressure and minimum-fuel-minimum-heat) for a two-dimensional model of an aerospace plane. A thorough statistical analysis is done on the hybrid technique to make comparisons with both basic genetic algorithms and particle swarm optimization techniques with respect to convergence and execution time. Genetic algorithm optimization showed better execution time performance while particle swarm optimization showed better convergence performance. The hybrid optimization technique, benefiting from both techniques, showed superior robust performance compromising convergence trends and execution time.

  8. Silicon Carbide Lightweight Optics With Hybrid Skins for Large Cryo Telescopes, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Optical Physics Company (OPC) has developed new silicon carbide (SiC) foam-based optics with hybrid skins that are composite, athermal and lightweight (FOCAL) that...

  9. DESI focal plate mechanical integration and cooling

    Science.gov (United States)

    Lambert, A. R.; Besuner, R. W.; Claybaugh, T. M.; Silber, J. H.

    2016-08-01

    The Dark Energy Spectroscopic Instrument (DESI) is under construction to measure the expansion history of the Universe using the Baryon Acoustic Oscillation technique[1]. The spectra of 40 million galaxies over 14000 sq. deg will be measured during the life of the experiment. A new prime focus corrector for the KPNO Mayall telescope will deliver light to 5000 fiber optic positioners. The fibers in turn feed ten broad-band spectrographs. This paper describes the mechanical integration of the DESI focal plate and the thermal system design. The DESI focal plate is comprised of ten identical petal assemblies. Each petal contains 500 robotic fiber positioners. Each petal is a complete, self-contained unit, independent from the others, with integrated power supply, controllers, fiber routing, and cooling services. The major advantages of this scheme are: (1) supports installation and removal of complete petal assemblies in-situ, without disturbing the others, (2) component production, assembly stations, and test procedures are repeated and parallelizable, (3) a complete, full-scale prototype can be built and tested at an early date, (4) each production petal can be surveyed and tested as a complete unit, prior to integration, from the fiber tip at the focal surface to the fiber slit at the spectrograph. The ten petal assemblies will be installed in a single integration ring, which is mounted to the DESI corrector. The aluminum integration ring attaches to the steel corrector barrel via a flexured steel adapter, isolating the focal plate from differential thermal expansions. The plate scale will be kept stable by conductive cooling of the petal assembly. The guider and wavefront sensors (one per petal) will be convectively cooled by forced flow of air. Heat will be removed from the system at ten liquid-cooled cold plates, one per petal, operating at ambient temperature. The entire focal plate structure is enclosed in an insulating shroud, which serves as a thermal barrier

  10. Radiopneumographic characteristics of focal pneumonia in children

    International Nuclear Information System (INIS)

    Smirnova, A.A.

    1980-01-01

    Zonal ventilation and blood flow were studied by the radiopneumography method in 50 children of school age with lower-lobe-of-the lung focal pneumonia (26 with left-side and 24 with right-side). It is established that during right-side localization of pneumonic focus preserved was the predomination of ventilation of right lung relative to left. Complete normalization of common and regional indexes of ventilation and blood flow was established by the 21st day from the beginning of treatment during right-side focal pneumonias. In case of left-side localization of pneumonic focus only partial reduction of external respiration and perfusion comes. Therefore, compensatory and reducing capabilities of right lung are preferrable

  11. Membership Functions for Fuzzy Focal Elements

    Directory of Open Access Journals (Sweden)

    Porębski Sebastian

    2016-09-01

    Full Text Available The paper presents a study on data-driven diagnostic rules, which are easy to interpret by human experts. To this end, the Dempster-Shafer theory extended for fuzzy focal elements is used. Premises of the rules (fuzzy focal elements are provided by membership functions which shapes are changing according to input symptoms. The main aim of the present study is to evaluate common membership function shapes and to introduce a rule elimination algorithm. Proposed methods are first illustrated with the popular Iris data set. Next experiments with five medical benchmark databases are performed. Results of the experiments show that various membership function shapes provide different inference efficiency but the extracted rule sets are close to each other. Thus indications for determining rules with possible heuristic interpretation can be formulated.

  12. Focal epilepsy in the Belgian shepherd

    DEFF Research Database (Denmark)

    Berendt, Mette; Gulløv, Christina Hedal; Fredholm, Merete

    2009-01-01

    and deceased) were ascertained through a telephone interview using a standardised questionnaire regarding seizure history and phenomenology. Living dogs were invited to a detailed clinical evaluation. Litters more than five years of age, or where epilepsy was present in all offspring before the age of five......, were included in the calculations of inheritance. results: Out of 199 family members, 66 dogs suffered from epilepsy. The prevalence of epilepsy in the family was 33%. Fifty-five dogs experienced focal seizures with or without secondary generalisation, while four dogs experienced primary generalised...... seizures. In seven dogs, seizures could not be classified. The mode of inheritance of epilepsy was simple Mendelian. CLINICAL SIGNIFICANCE: This study identified that the Belgian shepherd suffers from genetically transmitted focal epilepsy. The seizure phenomenology expressed by family members have...

  13. Chest pain in focal musculoskeletal disorders

    DEFF Research Database (Denmark)

    Stochkendahl, Mette Jensen; Christensen, Henrik Wulff

    2010-01-01

    overlapping conditions and syndromes of focal disorders, including Tietze syndrome, costochondritis, chest wall syndrome, muscle tenderness, slipping rib, cervical angina, and segmental dysfunction of the cervical and thoracic spine, have been reported to cause pain. For most of these syndromes, evidence......The musculoskeletal system is a recognized source of chest pain. However, despite the apparently benign origin, patients with musculoskeletal chest pain remain under-diagnosed, untreated, and potentially continuously disabled in terms of anxiety, depression, and activities of daily living. Several...... arises mainly from case stories and empiric knowledge. For segmental dysfunction, clinical features of musculoskeletal chest pain have been characterized in a few clinical trials. This article summarizes the most commonly encountered syndromes of focal musculoskeletal disorders in clinical practice....

  14. Error Analysis on Plane-to-Plane Linear Approximate Coordinate ...

    Indian Academy of Sciences (India)

    Abstract. In this paper, the error analysis has been done for the linear approximate transformation between two tangent planes in celestial sphere in a simple case. The results demonstrate that the error from the linear transformation does not meet the requirement of high-precision astrometry under some conditions, so the ...

  15. THERMAL EFFECTS ON CAMERA FOCAL LENGTH IN MESSENGER STAR CALIBRATION AND ORBITAL IMAGING

    Directory of Open Access Journals (Sweden)

    S. Burmeister

    2018-04-01

    Full Text Available We analyse images taken by the MErcury Surface, Space ENviorment, GEochemistry, and Ranging (MESSENGER spacecraft for the camera’s thermal response in the harsh thermal environment near Mercury. Specifically, we study thermally induced variations in focal length of the Mercury Dual Imaging System (MDIS. Within the several hundreds of images of star fields, the Wide Angle Camera (WAC typically captures up to 250 stars in one frame of the panchromatic channel. We measure star positions and relate these to the known star coordinates taken from the Tycho-2 catalogue. We solve for camera pointing, the focal length parameter and two non-symmetrical distortion parameters for each image. Using data from the temperature sensors on the camera focal plane we model a linear focal length function in the form of f(T = A0 + A1 T. Next, we use images from MESSENGER’s orbital mapping mission. We deal with large image blocks, typically used for the production of a high-resolution digital terrain models (DTM. We analyzed images from the combined quadrangles H03 and H07, a selected region, covered by approx. 10,600 images, in which we identified about 83,900 tiepoints. Using bundle block adjustments, we solved for the unknown coordinates of the control points, the pointing of the camera – as well as the camera’s focal length. We then fit the above linear function with respect to the focal plane temperature. As a result, we find a complex response of the camera to thermal conditions of the spacecraft. To first order, we see a linear increase by approx. 0.0107 mm per degree temperature for the Narrow-Angle Camera (NAC. This is in agreement with the observed thermal response seen in images of the panchromatic channel of the WAC. Unfortunately, further comparisons of results from the two methods, both of which use different portions of the available image data, are limited. If leaving uncorrected, these effects may pose significant difficulties in

  16. Characterization of LIL laser UV focal spot

    International Nuclear Information System (INIS)

    Mangeant, M.; Dubois, J.L.; Behar, G.; Arroyo, P.; Durand, V.; Lahonde, C.

    2006-01-01

    One way to get the fusion of hydrogen in laboratory consists in heating and compressing a DT fuel capsule by using a laser. To reach this aim requires a new generation of high power laser facility. Cea (French board for atomic energy) is developing for this purpose a new 240 laser line facility, the LMJ facility. The LIL which is the prototype of four LMJ laser lines is operational now. In order to confirm the technical choices, a systematic characterization of LIL was carried out. A particular effort has been provided to measure the 3ω high energy focal spot (1.5 kJ/700 ps and 5 ns for one beam) and the synchronization of laser beams onto the target, which are key issues for the plasma production. An experimental device, SAT-3ω (a 3ω laser focal spot analysis) has been designed to perform these measures. That diagnostic which is located at the end of the laser lines delivered its first results during the 2004 quadruplet qualification campaigns. The near field imaging showed no diaphony and vignetting. Low power spots allowed us to control we had no ghost. The energy measurement quality showed the photometric transfer function was perfectly known. Our caustic image are given with an average dynamic range of 800, a spatial resolution of 10 μm and diameter accuracy about 1% for 50% and 3% for 90% of encircled energy. The high energy focal spot diameters are in agreement with low and very low energy diameters. The phase plate and 14 GHz effects are similar to what we had expected. For a laser shot completed with a continuous phase plate at 14 GHz, and for an energy level of 1.5 kJ per beam at 351 nm, the focal beam diameter at 3% of the peak level is (875 ± 45) μm

  17. Proximal focal femoral deficiency: A case report

    Directory of Open Access Journals (Sweden)

    Shashank Sharma

    2015-01-01

    Full Text Available Proximal focal femoral deficiency (PFFD is a rare congenital anomaly resulting in limb shortening and disability in young. The exact cause of the disease is not known and it may present as varying grades of affection involving the proximal femur and the acetabulum. Recognition of this rare abnormality on radiographs can help manage these cases better since early institution of therapy may help in achieving adequate growth of the femur.

  18. Syndecan-4 and focal adhesion function

    DEFF Research Database (Denmark)

    Woods, A; Couchman, J R

    2001-01-01

    Two groups have now reported the viability of mice that lack syndecan-4. These mice have wound healing/angiogenesis problems, and fibroblasts from these animals differ in adhesion and migration from normal. This is consistent with recent in vitro data indicating a need for signaling via syndecan-4...... for focal adhesion formation, and reports that overexpression of proteins that bind syndecan-4 can modify cell adhesion and migration....

  19. Noninvasive treatment of focal adenomyosis with MR-guided focused ultrasound in two patients

    International Nuclear Information System (INIS)

    Polina, Laveena; Nyapathy, Vinay; Mishra, Anindita; Yellamanthili, Himabindu; Vallabhaneni, Mythri P

    2012-01-01

    Adenomyosis is a common benign gynecological disorder presenting with dysmenorrhea, menorrhagia, and pressure symptoms. Magnetic resonance imaging–guided focused ultrasound surgery (MRgFUS) utilizes precisely focused USG waves to generate and maintain high temperatures within the targeted tissue to achieve protein denaturation and coagulative necrosis. The heat generated is monitored using MRI images acquired in real-time in three planes. We present two cases of focal adenomyosis treated with MRgFUS showing good symptomatic relief at 3 and 6 months follow-up

  20. Investigation of fitting capability of active mirror for controlling ICF's focal profile

    International Nuclear Information System (INIS)

    Zeng Zhige; Ling Ning; Jiang Wenhan

    1998-01-01

    Laser beam's profile at focal plane can be controlled using active mirror in ICF system because the beam's profile has strong relationship with the surface of active mirror, the surface of active mirror can be changed at any time and maintained for a long time. The capabilities of fitting given wave-front (computed by Geometric Transformation Method) at conditions of different actuator numbers and different arrangement have been investigated by computer simulation. The computing results present that the needed laser profile can obtained by adaptive optical technology

  1. Focal adhesions, stress fibers and mechanical tension

    Energy Technology Data Exchange (ETDEWEB)

    Burridge, Keith, E-mail: Keith_Burridge@med.unc.edu [Department of Cell Biology and Physiology, and Lineberger Comprehensive Cancer Center, 12-016 Lineberger, CB#7295, University of North Carolina, Chapel Hill, NC (United States); Guilluy, Christophe, E-mail: christophe.guilluy@univ-nantes.fr [Inserm UMR-S1087, CNRS UMR-C6291, L' institut du Thorax, and Université de Nantes, Nantes (France)

    2016-04-10

    Stress fibers and focal adhesions are complex protein arrays that produce, transmit and sense mechanical tension. Evidence accumulated over many years led to the conclusion that mechanical tension generated within stress fibers contributes to the assembly of both stress fibers themselves and their associated focal adhesions. However, several lines of evidence have recently been presented against this model. Here we discuss the evidence for and against the role of mechanical tension in driving the assembly of these structures. We also consider how their assembly is influenced by the rigidity of the substratum to which cells are adhering. Finally, we discuss the recently identified connections between stress fibers and the nucleus, and the roles that these may play, both in cell migration and regulating nuclear function. - Highlights: • The different types of stress fiber and focal adhesion are described. • We discuss the controversy about tension and assembly of these structures. • We describe the different models used to investigate assembly of these structures. • The influence of substratum rigidity is discussed. • Stress fiber connections to the nucleus are reviewed.

  2. Effects on patient exposure dose and image quality by increasing focal film distance in abdominal radiography

    International Nuclear Information System (INIS)

    Kim, You Hyun; Kwon, Soo Il

    1998-01-01

    We can and must improve the diagnostic images using available knowledge and technology. At the same time we must strive to reduce thr patient's integral and entrance radiation dose. Reducing the integral dose to the patient during the radiologic procedure is a primary concern of the patient, especially the pediatric patient, the radiologist and the technologist. A 100cm focal film distance generally is used for most over-table radiography. The early x-ray tubes and screen film combinations required long exposures, which often resulted in motion artifacts. But nowadays, we have the generators and x-ray tubes that can deliver the energy necessary in a very short time and the receptors that can record the information just as rapidly. And, we performed this studies to evaluate the patient exposure dose and the image quality by increasing focal film distance in diagnostic radiography. There are many factors which affected to exposure factor, but we studied to verify of FFD increase, only. Effect of increasing the focal film distance to a 140 cm distance was tested as follows ; 1. The focal film distances were set at 100, 120, and 140cm. 2. A 18cm acryl(tissue equivalent) phantom was placed on the table top. 3. An Capintec 192 electrometer with PM 05 ion chamber was placed at the entrance surface of the phantom, and exposure were made at each focal film distances. 4. The procedure was repeated in the same manner as above except the ion chamber was placed beneath the phantom at the film plane. 5. Exit exposure were normalize to 8mR for each portions of the experiment. Based on the success of the empirical measurements, a detailed mathematical analysis of the dose reduction was performed using the percent depth dose data

  3. Classification of Focal and Non Focal Epileptic Seizures Using Multi-Features and SVM Classifier.

    Science.gov (United States)

    Sriraam, N; Raghu, S

    2017-09-02

    Identifying epileptogenic zones prior to surgery is an essential and crucial step in treating patients having pharmacoresistant focal epilepsy. Electroencephalogram (EEG) is a significant measurement benchmark to assess patients suffering from epilepsy. This paper investigates the application of multi-features derived from different domains to recognize the focal and non focal epileptic seizures obtained from pharmacoresistant focal epilepsy patients from Bern Barcelona database. From the dataset, five different classification tasks were formed. Total 26 features were extracted from focal and non focal EEG. Significant features were selected using Wilcoxon rank sum test by setting p-value (p z > 1.96) at 95% significance interval. Hypothesis was made that the effect of removing outliers improves the classification accuracy. Turkey's range test was adopted for pruning outliers from feature set. Finally, 21 features were classified using optimized support vector machine (SVM) classifier with 10-fold cross validation. Bayesian optimization technique was adopted to minimize the cross-validation loss. From the simulation results, it was inferred that the highest sensitivity, specificity, and classification accuracy of 94.56%, 89.74%, and 92.15% achieved respectively and found to be better than the state-of-the-art approaches. Further, it was observed that the classification accuracy improved from 80.2% with outliers to 92.15% without outliers. The classifier performance metrics ensures the suitability of the proposed multi-features with optimized SVM classifier. It can be concluded that the proposed approach can be applied for recognition of focal EEG signals to localize epileptogenic zones.

  4. Interaction of gravitational plane waves

    International Nuclear Information System (INIS)

    Ferrari, V.

    1988-01-01

    The mathematical theory of colliding, infinite-fronted, plane gravitational waves is presented. The process of focusing, the creation of singularities and horizons, due to the interaction, and the lens effect due to a beam-like gravitational wave are discussed

  5. Force Lines in Plane Stress

    DEFF Research Database (Denmark)

    Rathkjen, Arne

    A state of plane stress is illustrated by means of two families of curves, each family representing constant values of a derivative of Airy's stress function. The two families of curves form a map giving in the first place an overall picture of regions of high and low stress, and in the second...

  6. Blocking sets in Desarguesian planes

    NARCIS (Netherlands)

    Blokhuis, A.; Miklós, D.; Sós, V.T.; Szönyi, T.

    1996-01-01

    We survey recent results concerning the size of blocking sets in desarguesian projective and affine planes, and implications of these results and the technique to prove them, to related problemis, such as the size of maximal partial spreads, small complete arcs, small strong representative systems

  7. Gravitational Couplings for y-Gop-Planes

    OpenAIRE

    Giraldo, Juan Fernando Ospina

    2000-01-01

    The Wess-Zumino action for y deformed and generalized orientifold planes (yGOp-planes) is presented and one power expantion is realized from which processes that involves yGOp-planes, RR-forms, gravitons and gaugeons, are obtained. Finally non-standard yGOp-planes are showed.

  8. Gravitational Couplings for Generalized Orientifold Planes

    OpenAIRE

    Giraldo, Juan Fernando Ospina

    2000-01-01

    The Wess-Zumino action for generalized orientifold planes (GOp-planes) is presented and a series power expantion is realized from which processes that involves GOp-planes, RR-forms, gravitons and gaugeons, are obtained. Finally non-standard GOp-planes are showed.

  9. CALCULATION OF A GLARE STOP FOR TWO-MIRROR EXTRA-FOCAL OBJECTIVE

    Directory of Open Access Journals (Sweden)

    L. F. Zambrano

    2017-01-01

    Full Text Available Recently, efforts to improve optical characteristics in canonical mirror systems, including aspherical surfaces and corrective aberration capabilities. At the same time, much attention is paid to the development of new optical schemes of two-mirror objectives. Development measures to protect the image plane from stray light and harmful flows with minimal vignetting and screening is one of the most perspective ways for improving the image quality objectives. The only method to eliminate or even reduce these non-constructive rays is to set glare stops. The aim of the work was an improving method for constructing a glare stop to protect the image plane and the creation of a calculation algorithm of glare stop for protecting the image plane based on two-mirror extra-focal objectives.The study was conducted in two stages. In the course of the first stage, the positions of screening and intermediate image plane were obtained, as well as the central screening coefficient. At the second stage, an arrangement for the position of glare stop is proposed using the algorithm calculation. Thus, mathematical expressions were achieved by geometric constructions. The relation of the screening coefficient with the distance between the surfaces of the mirrors and the height of the paraxial rays is established. А representation of vignetting diagram for two-mirror extra-focal objective with D/f´ = 1 : 1,3 and 2ω = 4° was realized. The Q estimation of vignetting of inclined light beams is k= 0,56.

  10. Focal inflammatory diseases of the liver

    International Nuclear Information System (INIS)

    Oto, Aytekin; Akhan, Okan; Oezmen, Mustafa

    1999-01-01

    Inflammatory lesions constitute an important subgroup of focal liver lesions. They may mimic primary or metastatic neoplastic lesions and their differentiation from neoplasia is clinically very important since management of the patient significantly changes. Radiologists should have an important role in both the diagnosis and therapy of these lesions by performing percutaneous aspirations and drainages. In this review we discussed the radiological findings of pyogenic abscesses, amebic abscesses, candidiasis, tuberculosis, hydatic cysts, fascioliasis, ascariasis, schistosomiasis, and sarcoidosis with a special emphasis on US, CT and MR characteristics

  11. Focal inflammatory diseases of the liver

    Energy Technology Data Exchange (ETDEWEB)

    Oto, Aytekin; Akhan, Okan; Oezmen, Mustafa

    1999-10-01

    Inflammatory lesions constitute an important subgroup of focal liver lesions. They may mimic primary or metastatic neoplastic lesions and their differentiation from neoplasia is clinically very important since management of the patient significantly changes. Radiologists should have an important role in both the diagnosis and therapy of these lesions by performing percutaneous aspirations and drainages. In this review we discussed the radiological findings of pyogenic abscesses, amebic abscesses, candidiasis, tuberculosis, hydatic cysts, fascioliasis, ascariasis, schistosomiasis, and sarcoidosis with a special emphasis on US, CT and MR characteristics.

  12. Hydrodynamics of planing monohull watercraft

    CERN Document Server

    Vorus, William S

    2017-01-01

    This book addresses the principles involved in the design and engineering of planing monohull power boats, with an emphasis on the theoretical fundamentals that readers need in order to be fully functional in marine design and engineering. Author William Vorus focuses on three topics: boat resistance, seaway response, and propulsion and explains the physical principles, mathematical details, and theoretical details that support physical understanding. In particular, he explains the approximations and simplifications in mathematics that lead to success in the applications of planing craft design engineering, and begins with the simplest configuration that embodies the basic physics. He leads readers, step-by-step, through the physical complications that occur, leading to a useful working knowledge of marine design and engineering. Included in the book are a wealth of examples that exemplify some of the most important naval architecture and marine engineering problems that challenge many of today’s engineers.

  13. Plane waves with weak singularities

    International Nuclear Information System (INIS)

    David, Justin R.

    2003-03-01

    We study a class of time dependent solutions of the vacuum Einstein equations which are plane waves with weak null singularities. This singularity is weak in the sense that though the tidal forces diverge at the singularity, the rate of divergence is such that the distortion suffered by a freely falling observer remains finite. Among such weak singular plane waves there is a sub-class which does not exhibit large back reaction in the presence of test scalar probes. String propagation in these backgrounds is smooth and there is a natural way to continue the metric beyond the singularity. This continued metric admits string propagation without the string becoming infinitely excited. We construct a one parameter family of smooth metrics which are at a finite distance in the space of metrics from the extended metric and a well defined operator in the string sigma model which resolves the singularity. (author)

  14. Functional Aesthetic Occlusal Plane (FAOP)

    OpenAIRE

    Câmara, Carlos Alexandre; Martins, Renato Parsekian

    2016-01-01

    ABSTRACT Introduction: A reasonable exposure of incisors and gingival tissues is generally considered more attractive than excess or lack of exposure. A reasonable gingival exposure is considered to be around 0 to 2 mm when smiling and 2-4 mm exposure of the maxillary incisor edge when the lips are at rest. Objective: The aim of this paper is to present the Functional Aesthetic Occlusal Plane (FAOP), which aims to help in the diagnosis of the relationships established among molars, incisors...

  15. Small Hybrid Solar Power System

    OpenAIRE

    Kane, El Hadj Malick; Larrain, Diego; Favrat, Daniel

    2001-01-01

    This paper introduces a novel of mini-hybrid solar power plant integrating a field of solar concentrators, two superposed Organic Rankine Cycles (ORC) and a (bio)Diesel engine. Turbines for the organic Rankine Cycles are hermetic scroll expander-generators. Sun tracking solar collectors are composed of rows of flat mirror bands (CEP) arranged in a plane, which focus the solar energy onto a collector tube similar to those used in SEGS plant in California. The wast...

  16. Small Hybrid Solar Power System

    OpenAIRE

    Kane, El Hadj Malick; Favrat, Daniel; Larrain, Diego; Allani, Yassine

    2003-01-01

    This paper introduces a novel of mini-hybrid solar power plant integrating a field of solar concentrators, two superposed Organic Rankine Cycles (ORC) and a (bio)Diesel engine. Turbines for the organic Rankine Cycles are hermetic scroll expander-generators. Sun tracking solar collectors are composed of rows of flat mirror bands (CEP) arranged in a plane, which focus the solar energy onto a collector tube similar to those used in SEGS plant in California. The waste heat from both...

  17. Plane waves and spacelike infinity

    International Nuclear Information System (INIS)

    Marolf, Donald; Ross, Simon F

    2003-01-01

    In an earlier paper, we showed that the causal boundary of any homogeneous plane wave satisfying the null convergence condition consists of a single null curve. In Einstein-Hilbert gravity, this would include any homogeneous plane wave satisfying the weak null energy condition. For conformally flat plane waves such as the Penrose limit of AdS 5 x S 5 , all spacelike curves that reach infinity also end on this boundary and the completion is Hausdorff. However, the more generic case (including, e.g., the Penrose limits of AdS 4 x S 7 and AdS 7 x S 4 ) is more complicated. In one natural topology, not all spacelike curves have limit points in the causal completion, indicating the need to introduce additional points at 'spacelike infinity' - the endpoints of spacelike curves. We classify the distinct ways in which spacelike curves can approach infinity, finding a two-dimensional set of distinct limits. The dimensionality of the set of points at spacelike infinity is not, however, fixed from this argument. In an alternative topology, the causal completion is already compact, but the completion is non-Hausdorff

  18. Irregular focal mechanisms observed at Salton Sea Geothermal Field: Possible influences of anthropogenic stress perturbations

    Science.gov (United States)

    Crandall-Bear, Aren; Barbour, Andrew J.; Schoenball, Martin; Schoenball, Martin

    2018-01-01

    At the Salton Sea Geothermal Field (SSGF), strain accumulation is released through seismic slip and aseismic deformation. Earthquake activity at the SSGF often occurs in swarm-like clusters, some with clear migration patterns. We have identified an earthquake sequence composed entirely of focal mechanisms representing an ambiguous style of faulting, where strikes are similar but deformation occurs due to steeply-dipping normal faults with varied stress states. In order to more accurately determine the style of faulting for these events, we revisit the original waveforms and refine estimates of P and S wave arrival times and displacement amplitudes. We calculate the acceptable focal plane solutions using P-wave polarities and S/P amplitude ratios, and determine the preferred fault plane. Without constraints on local variations in stress, found by inverting the full earthquake catalog, it is difficult to explain the occurrence of such events using standard fault-mechanics and friction. Comparing these variations with the expected poroelastic effects from local production and injection of geothermal fluids suggests that anthropogenic activity could affect the style of faulting.

  19. Determination Hypocentre and Focal Mechanism Earthquake of Oct 31, 2016 in Bone, South Sulawesi

    Science.gov (United States)

    Altin Massinai, Muhammad; Fawzy Ismullah M, Muhammad

    2018-03-01

    Indonesian Meteorology, Climatology and Geophysics Agency (BMKG) recorded an earthquake with M4.6 on at October 31, 2016 at Bone District, around 80 Km northeast form Makassar, South Sulawesi. The earthquake occurred 18:18:14 local time in 4.7°S, 120°E with depth 10 Km. Seismicity around location predicted caused by activity Walennae fault. We reprocessed earthquake data to determine precise hypocentre location and focal mechanism. The P- and S-wave arrival time got from BMKG used as input HYPOELLIPSE code to determine hypocentre. The results showed that the earthquake occurred 10:18:14.46 UTC in 4.638°S, 119.966°E with depth 24.76 Km. The hypocentre resolved 10 Km fix depth and had lower travel time residual than BMKG result. Focal mechanism determination used Azmtak code based on the first arrival polarity at earthquake waveform manually picked. The result showed a reverse mechanism with strike direction 38°, dip 44°, rake angle 134° on fault plane I and strike direction 164°, dip 60°, rake angle 56° on fault plane II. So, the earthquake which may be related to a reverse East Walennae Fault.

  20. Idiopathic focal epilepsies: the "lost tribe".

    Science.gov (United States)

    Pal, Deb K; Ferrie, Colin; Addis, Laura; Akiyama, Tomoyuki; Capovilla, Giuseppe; Caraballo, Roberto; de Saint-Martin, Anne; Fejerman, Natalio; Guerrini, Renzo; Hamandi, Khalid; Helbig, Ingo; Ioannides, Andreas A; Kobayashi, Katsuhiro; Lal, Dennis; Lesca, Gaetan; Muhle, Hiltrud; Neubauer, Bernd A; Pisano, Tiziana; Rudolf, Gabrielle; Seegmuller, Caroline; Shibata, Takashi; Smith, Anna; Striano, Pasquale; Strug, Lisa J; Szepetowski, Pierre; Valeta, Thalia; Yoshinaga, Harumi; Koutroumanidis, Michalis

    2016-09-01

    The term idiopathic focal epilepsies of childhood (IFE) is not formally recognised by the ILAE in its 2010 revision (Berg et al., 2010), nor are its members and boundaries precisely delineated. The IFEs are amongst the most commonly encountered epilepsy syndromes affecting children. They are fascinating disorders that hold many "treats" for both clinicians and researchers. For example, the IFEs pose many of the most interesting questions central to epileptology: how are functional brain networks involved in the manifestation of epilepsy? What are the shared mechanisms of comorbidity between epilepsy and neurodevelopmental disorders? How do focal EEG discharges impact cognitive functioning? What explains the age-related expression of these syndromes? Why are EEG discharges and seizures so tightly locked to slow-wave sleep? In the last few decades, the clinical symptomatology and the respective courses of many IFEs have been described, although they are still not widely appreciated beyond the specialist community. Most neurologists would recognise the core syndromes of IFE to comprise: benign epilepsy of childhood with centro-temporal spikes or Rolandic epilepsy (BECTS/RE); Panayiotopoulos syndrome; and the idiopathic occipital epilepsies (Gastaut and photosensitive types). The Landau-Kleffner syndrome and the related (idiopathic) epilepsy with continuous spikes and waves in sleep (CSWS or ESES) are also often included, both as a consequence of the shared morphology of the interictal discharges and their potential evolution from core syndromes, for example, CSWS from BECTS. Atypical benign focal epilepsy of childhood also has shared electro-clinical features warranting inclusion. In addition, a number of less well-defined syndromes of IFE have been proposed, including benign childhood seizures with affective symptoms, benign childhood epilepsy with parietal spikes, benign childhood seizures with frontal or midline spikes, and benign focal seizures of adolescence. The

  1. Laparoscopic Partial Hepatectomy of Focal Nodular Hyperplasia

    Directory of Open Access Journals (Sweden)

    Mayu Sakata

    2012-11-01

    Full Text Available Focal nodular hyperplasia is a benign liver lesion incidentally discovered with increasing frequency because of the proliferation of imaging studies. Radiographic characterization can diagnose this pathologic lesion and nonoperative therapy is the standard of care. However, surgical resection may be required for diagnostic reasons or symptomatic patients. Depending on the anatomic location of the lesion, biopsy and/or resection can be performed laparoscopically. We herein report the case of a 26-year-old Japanese woman with a hepatic tumor who required a medical examination. Her medical history was negative for alcohol abuse, oral contraceptive administration and trauma. Clinical examination showed no significant symptoms. Ultrasonography, computed tomography and magnetic resonance imaging showed a mass located in the left lateral segment of the liver with a diameter of about 40 mm. It was difficult to diagnose the tumor definitively from these imaging studies, so we performed laparoscopic partial hepatectomy with successive firing of endoscopic staplers. The histopathological diagnosis was focal nodular hyperplasia. Surgical procedures and postoperative course were uneventful and the patient was discharged from the hospital on postoperative day 5.

  2. CT scan findings in focal epilepsy

    International Nuclear Information System (INIS)

    Kobayashi, Eiki; Mihara, Tadahiro; Yamamoto, Kunimitsu; Yamashita, Kenji; Asakura, Tetsuhiko

    1980-01-01

    In 80 cases of focal epilepsy, excluding such cases as late onset after the age of 30 and traumatic or expansive lesions, the epileptogenic foci have been studied by comparing the CT findings with the seizure types and the EEG findings. The results were as follows: (1) Abnormal CT findings were observed in 36% of the patients. (2) These findings were classified into 4 large groups: localized cerebral atrophy, localized low density, localized high density with contrast enhancement and diffuse cerebral atrophy. (3) The incidence of CT abnormality was higher in the cases with continuous and localized EEG abnormality than in the cases with other types of EEG abnormality. In 48% of the cases, the location of the abnormal CT findings coincided with their EEG foci. (4) In the cases of temporal lobe epilepsy without abnormal CT images, the print-out data compared with the bilateral promised temporal regions, before and after contrast enhancement. The EMI-No. of the medial temporal focus increased more than that of the contralateral side in 3 cases out of 4 after contrast-media injection. (5) Moreover, for the purpose of comparing the CT findings on general seizures with those in focal seizures, we have studied 80 cases of general seizures. In the cases of the general seizures, abnormal CT findings were observed in only 16%. These abnormal findings were diffuse in 5 cases, localized in 6 cases, and combined in 3 cases. (author)

  3. Focal CT abnormality and epileptogenic focus

    International Nuclear Information System (INIS)

    Yagi, Kazuichi; Mihara, Tadahiro; Tottori, Takayasu; Matsuda, Kazumi; Watanabe, Yutaka; Seino, Masakazu

    1989-01-01

    In 31 patients with temporal lobe epilepsy, the precise site of epileptogenic focus was determined by means of a depth EEG recording as one of the presurgical evaluations. In 13 patients, a CT scan revealed focal lesions; 7 in the left temporal lobe and 6 in the right temporal lobe. In 5 of the 7 patients and in 5 of the 6 patients the epileptogenic foci were determined in the temporal lobe on the side of a CT lesion. However, in 2 of the patients with a CT lesion in the left temporal lobe, independent epileptogenic foci were found in both the temporal lobes, and in the other patient with a CT lesion in the right temporal lobe, they were found in the right frontal and left temporal lobes. Thus, the CT lesions agreed in lateralization and focality with the epileptogenic foci in 10 of the 13 patients (77%), but they disagreed in 3 (23%). A CT lesion disclosed in the temporal lobe does not necessarily indicate the side and/or site where the epileptogenic focus may be localized. Although exceptions may be made, spatial disagreement was exemplified between the CT lesion and epileptogenic focus. Therefore, extreme caution has to be taken on the side and/or site of the epileptogenic focus when functional surgical indication is to be made. (author)

  4. Serial neuroradiological studies in focal cerebritis

    International Nuclear Information System (INIS)

    Hatta, S.; Mochizuki, H.; Kuru, Y.; Miwa, H.; Kondo, T.; Mori, H.; Mizuno, Y.

    1994-01-01

    We report serial neuroradiological studies in a patient with focal cerebritis in the head of the left caudate nucleus. On the day after the onset of symptoms, CT showed an ill-defined low density lesion. The lack of contrast enhancement appeared to be the most important finding for differentiating focal cerebritis from an encapsulated brain abscess or a tumour. MRI two days later revealed the centre of the lesion to be of slightly low intensity on T1-weighted inversion recovery (IR) images and very low intensity on T2-weighted spin echo images, which appeared to correspond to the early cerebritis stage of experimentally induced cerebritis and brain abscess. Ten days after the onset of symptoms, CT revealed a thin ring of enhancement in the head of the caudate nucleus, and a similar small ring was seen in the hypothalamus 16 days after the onset, corresponding to the late cerebritis stage. MRI nine days later revealed ill-defined high signal lesions within the involved area on the T1-weighted IR images. To our knowledge, this is the first published MRI documentation of the early cerebritis stage developing into an encapsulated brain abscess. The mechanisms underlying of these radiographic changes are discussed. (orig.)

  5. Structural and effective connectivity in focal epilepsy

    Directory of Open Access Journals (Sweden)

    Christopher S. Parker

    2018-01-01

    Full Text Available Patients with medically-refractory focal epilepsy may be candidates for neurosurgery and some may require placement of intracranial EEG electrodes to localise seizure onset. Assessing cerebral responses to single pulse electrical stimulation (SPES may give diagnostically useful data. SPES produces cortico-cortical evoked potentials (CCEPs, which infer effective brain connectivity. Diffusion-weighted images and tractography may be used to estimate structural brain connectivity. This combination provides the opportunity to observe seizure onset and its propagation throughout the brain, spreading contiguously along the cortex explored with electrodes, or non-contiguously. We analysed CCEPs and diffusion tractography in seven focal epilepsy patients and reconstructed the effective and structural brain networks. We aimed to assess the inter-modal similarity of the networks at a large scale across the cortex, the effective and structural connectivity of the ictal-onset zone, and investigate potential mechanisms of non-contiguous seizure spread. We found a significant overlap between structural and effective networks. Effective network CCEP amplitude, baseline variation, and outward connectivity was higher at ictal-onset zones, while structural connection strength within the ictal-onset zone tended to be higher. These findings support the concept of hyperexcitable cortex being associated with seizure generation. The high prevalence of structural and effective connections from the ictal-onset zone to sites of non-contiguous spread suggests that macroscopic structural and effective connections are plausible routes for non-contiguous seizure spread.

  6. Ultrasound elastographic techniques in focal liver lesions.

    Science.gov (United States)

    Conti, Clara Benedetta; Cavalcoli, Federica; Fraquelli, Mirella; Conte, Dario; Massironi, Sara

    2016-03-07

    Elastographic techniques are new ultrasound-based imaging techniques developed to estimate tissue deformability/stiffness. Several ultrasound elastographic approaches have been developed, such as static elastography, transient elastography and acoustic radiation force imaging methods, which include point shear wave and shear wave imaging elastography. The application of these methods in clinical practice aims at estimating the mechanical tissues properties. One of the main settings for the application of these tools has been liver stiffness assessment in chronic liver disease, which has been studied mainly using transient elastography. Another field of application for these techniques is the assessment of focal lesions, detected by ultrasound in organs such as pancreas, prostate, breast, thyroid, lymph nodes. Considering the frequency and importance of the detection of focal liver lesions through routine ultrasound, some studies have also aimed to assess the role that elestography can play in studying the stiffness of different types of liver lesions, in order to predict their nature and thus offer valuable non-invasive methods for the diagnosis of liver masses.

  7. Focal fatty infiltra- tion and focal fatty sparing of the liver

    African Journals Online (AJOL)

    Enrique

    Department of Radiology. Nelson Mandela School of Health Sciences. Durban. Fig. 1a. Unenhanced CT of the liver in case 1 demonstrates multiple focal low density regions in both lobes of the liver. Region of interest 1 over the fatty left lobe measured 10 HU while region of interest 2 over the right lobe measure 40 HU in.

  8. Centralized, Decentralized, and Hybrid Purchasing Organizations

    DEFF Research Database (Denmark)

    Bals, Lydia; Turkulainen, Virpi

    This paper addresses one of the focal issues in purchasing and supply management – global sourcing – from an organizational design perspective. In particular, we elaborate the traditional classification of global sourcing organization designs into centralized, decentralized, and hybrid models. We...... organization we can identify organization designs beyond the classical centralization-decentralization continuum. We also provide explanations for the observed organization design at GCC. The study contributes to research on purchasing and supply management as well as research on organization design....

  9. Three-dimensional fluorescent microscopy via simultaneous illumination and detection at multiple planes.

    Science.gov (United States)

    Ma, Qian; Khademhosseinieh, Bahar; Huang, Eric; Qian, Haoliang; Bakowski, Malina A; Troemel, Emily R; Liu, Zhaowei

    2016-08-16

    The conventional optical microscope is an inherently two-dimensional (2D) imaging tool. The objective lens, eyepiece and image sensor are all designed to capture light emitted from a 2D 'object plane'. Existing technologies, such as confocal or light sheet fluorescence microscopy have to utilize mechanical scanning, a time-multiplexing process, to capture a 3D image. In this paper, we present a 3D optical microscopy method based upon simultaneously illuminating and detecting multiple focal planes. This is implemented by adding two diffractive optical elements to modify the illumination and detection optics. We demonstrate that the image quality of this technique is comparable to conventional light sheet fluorescent microscopy with the advantage of the simultaneous imaging of multiple axial planes and reduced number of scans required to image the whole sample volume.

  10. Some Considerations Regarding Plane to Plane Parallelism Error Effects in Robotic Systems

    Directory of Open Access Journals (Sweden)

    Stelian Alaci

    2015-06-01

    Full Text Available The paper shows that by imposing the parallelism constraint between the measured plane and the reference plane, the position of the current plane is not univocal specified and is impossible to specify the way to attain the parallelism errors imposed by accuracy constrains. The parameters involved in the calculus of plane to plane parallelism error can be used to set univocal the relative position between the two planes.

  11. Hybrid reactors

    International Nuclear Information System (INIS)

    Moir, R.W.

    1980-01-01

    The rationale for hybrid fusion-fission reactors is the production of fissile fuel for fission reactors. A new class of reactor, the fission-suppressed hybrid promises unusually good safety features as well as the ability to support 25 light-water reactors of the same nuclear power rating, or even more high-conversion-ratio reactors such as the heavy-water type. One 4000-MW nuclear hybrid can produce 7200 kg of 233 U per year. To obtain good economics, injector efficiency times plasma gain (eta/sub i/Q) should be greater than 2, the wall load should be greater than 1 MW.m -2 , and the hybrid should cost less than 6 times the cost of a light-water reactor. Introduction rates for the fission-suppressed hybrid are usually rapid

  12. Focal mechanisms and tidal modulation for tectonic tremors in Taiwan

    Science.gov (United States)

    Ide, S.; Yabe, S.; Tai, H. J.; Chen, K. H.

    2015-12-01

    Tectonic tremors in Taiwan have been discovered beneath the southern Central Range, but their hosting structure has been unknown. Here we constrain the focal mechanism of underground deformation related to tremors, using moment tensor inversion in the very low frequency band and tidal stress analysis. Three types of seismic data are used for two analysis steps: detection of tremors and the moment tensor inversion. Short-period seismograms from CWBSN are used for tremor detection. Broadband seismograms from BATS and the TAIGER project are used for both steps. About 1000 tremors were detected using an envelope correlation method in the high frequency band (2-8 Hz). Broadband seismograms are stacked relative to the tremor timing, and inverted for a moment tensor in the low frequency band (0.02-0.05 Hz). The best solution was obtained at 32 km depth, as a double-couple consistent with a low-angle thrust fault dipping to the east-southeast, or a high-angle thrust with a south-southwest strike. Almost all tremors occur when tidal shear stress is positive and normal stress is negative (clamping). Since the clamping stress is high for a high-angle thrust fault, the low-angle thrust fault is more likely to be the fault plane. Tremor rate increases non-linearly with increasing shear stress, suggesting a velocity strengthening friction law. The high tidal sensitivity is inconsistent with horizontal slip motion suggested by previous studies, and normal faults that dominates regional shallow earthquakes. Our results favor thrust slip on a low-angle fault dipping to the east-southeast, consistent with the subduction of the Eurasian plate. The tremor region is characterized by a deep thermal anomaly with decrease normal stress. This region has also experienced enough subduction to produce metamorphic fluids. A large amount of fluid and low vertical stress may explain the high tidal sensitivity.

  13. CT appearance of focal fatty infiltration of the liver

    International Nuclear Information System (INIS)

    Halvorsen, R.A.; Korobkin, M.; Ram, P.C.; Thompson, W.M.

    1982-01-01

    Focal fatty infiltration of the liver is an entity that may be confused with liver metastasis on computed tomography (CT). The imaging results and medical records of 16 patients with CT appearance suggestive of focal fatty liver were reviewed, three of whom had the simultaneous presence of metastitic liver disease. Focal fatty liver often has a distinctive appearance with CT, usually with a nonspherical shape, absence of mass effect, and density close to water. Liver metastases are usually round or oval, and unless cystic or necrotic, they have CT attenuation values closer to normal liver parenchyma than water. A radionuclide liver scan almost always resolves any confusion about the differential diagnosis of focal fatty liver: a well defined focus of photon deficiency is due to neoplasm rather than focal fatty infiltration. Sonography sometimes helps to confirm the CT impression, but may be misleading if the diagnosis of focal or diffuse fatty infiltration is not suspected before the examination

  14. The study of the focal trough in panoramic radiograph

    International Nuclear Information System (INIS)

    Park, C. S.; Kim, H. P.

    1982-01-01

    In the study of the focal trough of panoramic radiograph, using the Moritta company Panex EC a series of 48 exposures were taken with the 6-18 brass pins placed in the holes of the plastic model plate, then evaluated by 4 observers. The author analyzed the focal trough defined by the sharpness criteria and calculated the vertical and horizontal magnification range in the corrected focal trough. The results were as follows; 1. Continuous focal trough was not defined in the anterior region using a very high degree of sharpness. 2. As degree of sharpness used in the analysis became less, focal trough was continuous in the anterior and posterior regions, symmetrized bilaterally, and the widths of the focal trough increased more in the posterior region. 3. As sharpness criteria were reduced, the percentage range of image magnification increased in both vertical and horizontal magnification, and especially the percentage range of horizontal magnification was greater than that of vertical magnification.

  15. Multi-focal Vision and Gaze Control Improve Navigation Performance

    Directory of Open Access Journals (Sweden)

    Kolja Kuehnlenz

    2008-11-01

    Full Text Available Multi-focal vision systems comprise cameras with various fields of view and measurement accuracies. This article presents a multi-focal approach to localization and mapping of mobile robots with active vision. An implementation of the novel concept is done considering a humanoid robot navigation scenario where the robot is visually guided through a structured environment with several landmarks. Various embodiments of multi-focal vision systems are investigated and the impact on navigation performance is evaluated in comparison to a conventional mono-focal stereo set-up. The comparative studies clearly show the benefits of multi-focal vision for mobile robot navigation: flexibility to assign the different available sensors optimally in each situation, enhancement of the visible field, higher localization accuracy, and, thus, better task performance, i.e. path following behavior of the mobile robot. It is shown that multi-focal vision may strongly improve navigation performance.

  16. Work Planing Automation at Mechanical Subdivision

    OpenAIRE

    Dzindzelėta, Vytautas

    2005-01-01

    Work planing automation, installation possibilities and future outlook at mechanical subdivision. To study how the work planing has changed before and after automation process and to analyse automation process methodology.

  17. Combinatorial geometry in the plane

    CERN Document Server

    Hadwiger, Hugo; Klee, Victor

    2014-01-01

    Geared toward advanced undergraduates familiar with analysis and college geometry, this concise book discusses theorems on topics restricted to the plane such as convexity, coverings, and graphs. In addition to helping students cultivate rigorous thought, the text encourages the development of mathematical intuition and clarifies the nature of mathematical research.The two-part treatment begins with specific topics including integral distances, covering problems, point set geometry and convexity, simple paradoxes involving point sets, and pure combinatorics, among other subjects. The second pa

  18. Fault plane orientations of deep earthquakes in the Izu-Bonin-Marianas subduction zone system

    Science.gov (United States)

    Myhill, R.; Warren, L. M.

    2011-12-01

    We present the results of directivity analysis on 45 deep earthquakes within the Izu-Bonin-Marianas subduction zone between 1993 and 2011. The age of the subducting Pacific plate increases from north to south along the trench, from 120 Ma offshore Tokyo to over 150 Ma east of the Mariana Islands. The dip of the deep slab generally increases from north to south, and is steep to overturned beneath the southern Bonin Islands and Marianas. Between 34 and 26 degrees north, a peak in seismicity at 350-450 km depth marks a decrease in dip as the slab approaches the base of the upper mantle. We observe directivity for around 60 percent of the analysed earthquakes, and use the propagation characteristics to find the best fitting rupture vector. In 60-70 percent of cases with well constrained rupture directivity, the best fitting rupture vector allows discrimination of the fault plane and the auxiliary plane of the focal mechanism. The identified fault planes between 100 km and 500 km are predominantly near-horizontal or south-southwest dipping. Rotated into the plane of the slab, the fault plane poles form a single cluster, since the more steeply dipping fault planes are found within more steeply dipping sections of slab. The dominance of near-horizontal fault planes at intermediate depth agrees with results from previous studies of the Tonga and Middle-America subduction zones. However, the presence of a single preferred fault plane orientation for large deep-focus earthquakes has not been previously reported, and contrasts with the situation for deep-focus earthquakes in the Tonga-Kermadec subduction system. Ruptures tend to propagate away from the top surface of the slab. We discuss potential causes of preferred fault plane orientations within subducting slabs in the light of existing available data, and the implications for mechanisms of faulting at great depths within the Earth.

  19. Focal cemento-osseous dysplasia of mandible.

    Science.gov (United States)

    Cankaya, Abdülkadir Burak; Erdem, Mehmet Ali; Olgac, Vakur; Firat, Deniz Refia

    2012-09-03

    Fibro-osseous lesions are disturbances in bone metabolism in which normal bone is replaced by a connective tissue matrix that then gradually develops into cemento-osseous tissue. Typically, the lesion is asymptomatic and is detected on routine radiographic examination. Radiologically, this lesion has three stages of maturation: pure radiolucent, radiopaque/mixed radiolucent, and radiopaque appearance. During these stages the lesion can be misdiagnosed. In this case report a 69-year- old patient with a a complaint of painless swelling of the left mandibular molar and premolar area is presented along with a review of the differential diagnoses considered in order to reach a final diagnosis of focal cemento-osseous dysplasia.

  20. Pharmacological response of systemically derived focal epileptic lesions

    Energy Technology Data Exchange (ETDEWEB)

    Remler, M.P.; Sigvardt, K.; Marcussen, W.H.

    1986-11-01

    Focal epileptic lesions were made in rats by systemic focal epileptogenesis. In this method, a focal lesion of the blood-brain barrier (BBB) is produced by focal alpha irradiation followed by repeated systemic injection of a convulsant drug that cannot cross the normal BBB, resulting in a chronic epileptic focus. Changes in the spike frequency of these foci in response to various drugs was recorded. The controls, saline and chlorpromazine, produced no change. Phenytoin, phenobarbital, chlordiazepoxide, and valproic acid produced the expected decrease in spike frequency. Pentobarbital and diazepam produced a paradoxical increase in spike frequency.

  1. Focal cryotherapy: step by step technique description

    Directory of Open Access Journals (Sweden)

    Cristina Redondo

    Full Text Available ABSTRACT Introduction and objective: Focal cryotherapy emerged as an efficient option to treat favorable and localized prostate cancer (PCa. The purpose of this video is to describe the procedure step by step. Materials and methods: We present the case of a 68 year-old man with localized PCa in the anterior aspect of the prostate. Results: The procedure is performed under general anesthesia, with the patient in lithotomy position. Briefly, the equipment utilized includes the cryotherapy console coupled with an ultrasound system, argon and helium gas bottles, cryoprobes, temperature probes and an urethral warming catheter. The procedure starts with a real-time trans-rectal prostate ultrasound, which is used to outline the prostate, the urethra and the rectal wall. The cryoprobes are pretested and placed in to the prostate through the perineum, following a grid template, along with the temperature sensors under ultrasound guidance. A cystoscopy confirms the right positioning of the needles and the urethral warming catheter is installed. Thereafter, the freeze sequence with argon gas is started, achieving extremely low temperatures (-40°C to induce tumor cell lysis. Sequentially, the thawing cycle is performed using helium gas. This process is repeated one time. Results among several series showed a biochemical disease-free survival between 71-93% at 9-70 month- follow-up, incontinence rates between 0-3.6% and erectile dysfunction between 0-42% (1–5. Conclusions: Focal cryotherapy is a feasible procedure to treat anterior PCa that may offer minimal morbidity, allowing good cancer control and better functional outcomes when compared to whole-gland treatment.

  2. Multispecies, Integrative GWAS for Focal Segmental Glomerulosclerosis

    Science.gov (United States)

    2017-09-01

    for the phenotypic analysis of the newly generated transgenic F1 hybrids. Serum will be analyzed for blood urea nitrogen, albumin , cholesterol...under a particular item, state “Nothing to Report.”  Publications, conference papers , and presentations Report only the major publication(s...resulting from the work under this award. Journal publications. List peer-reviewed articles or papers appearing in scientific, technical, or

  3. Neutronics issues in fusion-fission hybrid reactor design

    International Nuclear Information System (INIS)

    Liu Chengan

    1995-01-01

    The coupled neutron and γ-ray transport equations and nuclear number density equations, and its computer program systems concerned in fusion-fission hybrid reactor design are briefly described. The current status and focal point for coming work of nuclear data used in fusion reactor design are explained

  4. Sighting optics including an optical element having a first focal length and a second focal length and methods for sighting

    Science.gov (United States)

    Crandall, David Lynn

    2011-08-16

    Sighting optics include a front sight and a rear sight positioned in a spaced-apart relation. The rear sight includes an optical element having a first focal length and a second focal length. The first focal length is selected so that it is about equal to a distance separating the optical element and the front sight and the second focal length is selected so that it is about equal to a target distance. The optical element thus brings into simultaneous focus for a user images of the front sight and the target.

  5. An introduction to finite projective planes

    CERN Document Server

    Albert, Abraham Adrian

    2015-01-01

    Geared toward both beginning and advanced undergraduate and graduate students, this self-contained treatment offers an elementary approach to finite projective planes. Following a review of the basics of projective geometry, the text examines finite planes, field planes, and coordinates in an arbitrary plane. Additional topics include central collineations and the little Desargues' property, the fundamental theorem, and examples of finite non-Desarguesian planes.Virtually no knowledge or sophistication on the part of the student is assumed, and every algebraic system that arises is defined and

  6. On the relationships between electron spot size, focal spot size, and virtual source position in Monte Carlo simulations

    International Nuclear Information System (INIS)

    Sterpin, E.; Chen, Y.; Lu, W.; Mackie, T. R.; Olivera, G. H.; Vynckier, S.

    2011-01-01

    Purpose: Every year, new radiotherapy techniques including stereotactic radiosurgery using linear accelerators give rise to new applications of Monte Carlo (MC) modeling. Accurate modeling requires knowing the size of the electron spot, one of the few parameters to tune in MC models. The resolution of integrated megavoltage imaging systems, such as the tomotherapy system, strongly depends on the photon spot size which is closely related to the electron spot. The aim of this article is to clarify the relationship between the electron spot size and the photon spot size (i.e., the focal spot size) for typical incident electron beam energies and target thicknesses. Methods: Three electron energies (3, 5.5, and 18 MeV), four electron spot sizes (FWHM=0, 0.5, 1, and 1.5 mm), and two tungsten target thicknesses (0.15 and 1 cm) were considered. The formation of the photon beam within the target was analyzed through electron energy deposition with depth, as well as photon production at several phase-space planes placed perpendicular to the beam axis, where only photons recorded for the first time were accounted for. Photon production was considered for ''newborn'' photons intersecting a 45x45 cm 2 plane at the isocenter (85 cm from source). Finally, virtual source position and ''effective'' focal spot size were computed by backprojecting all the photons from the bottom of the target intersecting a 45x45 cm 2 plane. The virtual source position and focal spot size were estimated at the plane position where the latter is minimal. Results: In the relevant case of considering only photons intersecting the 45x45 cm 2 plane, the results unambiguously showed that the effective photon spot is created within the first 0.25 mm of the target and that electron and focal spots may be assumed to be equal within 3-4%. Conclusions: In a good approximation photon spot size equals electron spot size for high energy X-ray treatments delivered by linear accelerators.

  7. Hybrid composites

    CSIR Research Space (South Africa)

    Jacob John, Maya

    2009-04-01

    Full Text Available mixed short sisal/glass hybrid fibre reinforced low density polyethylene composites was investigated by Kalaprasad et al [25].Chemical surface modifications such as alkali, acetic anhydride, stearic acid, permanganate, maleic anhydride, silane...

  8. Determinations of directions of the mean stress field in Sichuan-Yunnan region from a number of focal mechanism solutions

    Science.gov (United States)

    Zhong, Ji-Mao; Cheng, Wan-Zheng

    2006-07-01

    Based on the spatial orientation and slip direction of the fault plane solutions, we present the expression of corresponding mechanical axis tensor in geographic coordinate system, and then put forward a method for calculating average mechanical axis tensor and its eigenvalues, which involves solving the corresponding eigenequation. The method for deducing mean stress field from T, B, and P axes parameters of a number of focal mechanism solutions has been verified by inverting data of mean stress fields in Fuyun region and in Tangshan region with fitting method of slip direction, and both results are consistent. To study regional average stress field, we need to choose a population of focal mechanism solutions of earthquakes in the massifs where there are significant tectonic structures. According to the focal mechanism solutions of 256 moderate-strong earthquakes occurred in 13 seismic zones of Sichuan-Yunnan region, the quantitative analysis results of stress tensor in each seismic zone have been given. The algorithm of such method is simple and convenient, which makes the method for analyzing tectonic stress field with large amount of focal mechanism solution data become quantified.

  9. Hybrid intermediaries

    OpenAIRE

    Cetorelli, Nicola

    2014-01-01

    I introduce the concept of hybrid intermediaries: financial conglomerates that control a multiplicity of entity types active in the "assembly line" process of modern financial intermediation, a system that has become known as shadow banking. The complex bank holding companies of today are the best example of hybrid intermediaries, but I argue that financial firms from the "nonbank" space can just as easily evolve into conglomerates with similar organizational structure, thus acquiring the cap...

  10. Radiologic manifestations of focal cerebral hyperemia in acute stroke

    DEFF Research Database (Denmark)

    Olsen, Tom Skyhøj; Skriver, E B; Herning, M

    1991-01-01

    In 16 acute stroke patients with focal cerebral hyperemia angiography and regional cerebral blood flow (rCBF) were studied 1 to 4 days post stroke. CT was performed twice with and without contrast enhancement 3 +/- 1 days and 16 +/- 4 days post stroke. Angiographic evidence of focal cerebral hype...

  11. Focal decompositions for linear differential equations of the second order

    Directory of Open Access Journals (Sweden)

    L. Birbrair

    2003-01-01

    two-points problems to itself such that the image of the focal decomposition associated to the first equation is a focal decomposition associated to the second one. In this paper, we present a complete classification for linear second-order equations with respect to this equivalence relation.

  12. Focal necrotizing pneumonia is a distinct entity from lung abscess.

    Science.gov (United States)

    Seo, Hyewon; Cha, Seung-Ick; Shin, Kyung-Min; Lim, Jaekwang; Yoo, Seung-Soo; Lee, Jaehee; Lee, Shin-Yup; Kim, Chang-Ho; Park, Jae-Yong

    2013-10-01

    'Focal necrotizing pneumonia' was defined as a localized type of necrotizing pneumonia characterized by a single or few cavities of low density without rim enhancement on computed tomography (CT) scan. The purpose of this study was to investigate the clinical features and course of patients with focal necrotizing pneumonia, thereby elucidating its clinical relevance. The present study was conducted retrospectively in patients who had been interpreted as having lung abscess or necrotizing pneumonia on CT scan. Clinical and radiological characteristics were compared between the focal necrotizing pneumonia and lung abscess groups. Overall, 68 patients with focal necrotizing pneumonia (n = 35) or lung abscess (n = 33) were included in the present study. The frequency of risk factors for aspiration was significantly lower in the focal necrotizing group, compared with the lung abscess group (14.3% vs 45.5%, P = 0.005). Compared with lung abscess, focal necrotizing pneumonia was observed more commonly in non-gravity-dependent segments (66% vs 36%, P lung abscess group (31% vs 12%, P = 0.08). However, in terms of treatment outcomes, a similar high rate of success was observed in both groups: 97%, respectively. Compared to lung abscess, focal necrotizing pneumonia occurs more commonly in non-gravity-dependent segments with lower incidence of risk factors for aspiration. Similar to lung abscess, the rate of success for treatment of focal necrotizing pneumonia was high. © 2013 The Authors. Respirology © 2013 Asian Pacific Society of Respirology.

  13. Proximal Focal Femoral Deficiency in Ibadan a Developing ...

    African Journals Online (AJOL)

    The cultural aversion to amputation in our environment makes it difficult to employ that option of treatment. Proximal focal femoral deficiency in Ibadan a developing country's perspective and a review of the literature. Keywords: Proximal focal femoral deficiency , congenital malformations , limb malformations , lower limb ...

  14. Concordance of MRI and EEG Focal Slowing in Nonsyndromic Epilepsy

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2013-04-01

    Full Text Available Investigators at the Kangwon National University, Korea, and The Epilepsy Center, Lurie Children’s Hospital of Chicago, USA studied the correlation and significance of EEG focal slowing and focal MRI abnormalities in 253 children with nonsyndromic epilepsy.

  15. Fast Focal Point Correction in Prism-Coupled Total Internal Reflection Scanning Imager Using an Electronically Tunable Lens

    Directory of Open Access Journals (Sweden)

    Chenggang Zhu

    2018-02-01

    Full Text Available Total internal reflection (TIR is useful for interrogating physical and chemical processes that occur at the interface between two transparent media. Yet prism-coupled TIR imaging microscopes suffer from limited sensing areas due to the fact that the interface (the object plane is not perpendicular to the optical axis of the microscope. In this paper, we show that an electrically tunable lens can be used to rapidly and reproducibly correct the focal length of an oblique-incidence scanning microscope (OI-RD in a prism-coupled TIR geometry. We demonstrate the performance of such a correction by acquiring an image of a protein microarray over a scan area of 4 cm2 with an effective resolution of less than 20 microns. The electronic focal length tuning eliminates the mechanical movement of the illumination lens in the scanning microscope and in turn the noise and background drift associated with the motion.

  16. An empirical assessment of the focal species hypothesis.

    Science.gov (United States)

    Lindenmayer, D B; Lane, P W; Westgate, M J; Crane, M; Michael, D; Okada, S; Barton, P S

    2014-12-01

    Biodiversity surrogates and indicators are commonly used in conservation management. The focal species approach (FSA) is one method for identifying biodiversity surrogates, and it is underpinned by the hypothesis that management aimed at a particular focal species will confer protection on co-occurring species. This concept has been the subject of much debate, in part because the validity of the FSA has not been subject to detailed empirical assessment of the extent to which a given focal species actually co-occurs with other species in an assemblage. To address this knowledge gap, we used large-scale, long-term data sets of temperate woodland birds to select focal species associated with threatening processes such as habitat isolation and loss of key vegetation attributes. We quantified co-occurrence patterns among focal species, species in the wider bird assemblage, and species of conservation concern. Some, but not all, focal species were associated with high levels of species richness. One of our selected focal species was negatively associated with the occurrence of other species (i.e., it was an antisurrogate)-a previously undescribed property of nominated focal species. Furthermore, combinations of focal species were not associated with substantially elevated levels of bird species richness, relative to levels associated with individual species. Our results suggest that although there is some merit to the underpinning concept of the FSA, there is also a need to ensure that actions are sufficiently flexible because management tightly focused on a given focal species may not benefit some other species, including species of conservation concern, such of which might not occur in species-rich assemblages. © 2014 Society for Conservation Biology.

  17. [Sotos syndrome associated with focal dystonia].

    Science.gov (United States)

    Bravo, M; Chacón, J; Bautista, E; Pérez-Camacho, I; Trujillo, A; Grande, M A

    Sotos syndrome is a form of infantile gigantism characterized by excessive body size from the time of birth, particular facies, acromegalic changes and signs of non-progressive cerebral involvement. The etiology is unknown. Diagnosis is based on somatometric data and the particular phenotype traits. Biochemical and endocrine studies are normal. Torticollis is a focal dystonia and therefore more common in adults. A 20 year old woman with macrosomic features since birth presented with: weight 104 kg, height 182 cm; prognathism, hypertelorism, a broad over hanging forehead with a high hair line; large ears, hands and feet; torticollis towards the right with elevation and anteroversion of the right shoulder which caused symptomatic scoliosis. She was bradypsychic and rather slow in speech. The complementary tests done (cerebral and cervical CT and MR, bone gammography, evoked potentials, EMG-ENG, sural nerve biopsy, biopsy of skin and muscle, EEG and hormone and biochemistry studies) were normal. The torticollis was treated with botulinus toxin and improved considerably, as did the scoliosis. To date, dystonia has not been described in association with Sotos syndrome. This may be a causal association, or even perhaps hereditary, since the patient's mother had dystonia (in the form of blepharospasm).

  18. Depression in focal, segmental and generalized dystonia.

    Science.gov (United States)

    Lewis, L; Butler, A; Jahanshahi, M

    2008-11-01

    Dystonia causes body disfigurement in the majority of those affected. Our aim was to test the hypothesis that low self-esteem resulting from the sense of disfigurement is an important component of self-reported depression in focal, segmental and generalized dystonia. Questionnaires to assess self-reported depression, self-esteem, body concept, disfigurement, disability and quality of life were completed by 329 community based dystonia patients. Moderate to severe depression was reported by 30 %. Self-reported depression had a strong somatic component, but patients also showed a specific concern with self-image. Extent of dystonia, body parts affected and marital status influenced self-reported depression in dystonia. Self esteem, body concept, disfigurement and quality of life emerged as factors which accounted for the variance of self-reported depression in dystonia. These results suggest that in dystonia, disfigurement, negative body concept, low self-esteem, and the impact of the disease on quality of life make important contributions to depression. However, longitudinal followup is required to firmly establish the direction of causality between depression and these psychosocial variables in dystonia.

  19. Visual agnosia and focal brain injury.

    Science.gov (United States)

    Martinaud, O

    Visual agnosia encompasses all disorders of visual recognition within a selective visual modality not due to an impairment of elementary visual processing or other cognitive deficit. Based on a sequential dichotomy between the perceptual and memory systems, two different categories of visual object agnosia are usually considered: 'apperceptive agnosia' and 'associative agnosia'. Impaired visual recognition within a single category of stimuli is also reported in: (i) visual object agnosia of the ventral pathway, such as prosopagnosia (for faces), pure alexia (for words), or topographagnosia (for landmarks); (ii) visual spatial agnosia of the dorsal pathway, such as cerebral akinetopsia (for movement), or orientation agnosia (for the placement of objects in space). Focal brain injuries provide a unique opportunity to better understand regional brain function, particularly with the use of effective statistical approaches such as voxel-based lesion-symptom mapping (VLSM). The aim of the present work was twofold: (i) to review the various agnosia categories according to the traditional visual dual-pathway model; and (ii) to better assess the anatomical network underlying visual recognition through lesion-mapping studies correlating neuroanatomical and clinical outcomes. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  20. Nonhuman primate models of focal cerebral ischemia

    Directory of Open Access Journals (Sweden)

    Jingjing Fan

    2017-01-01

    Full Text Available Rodents have been widely used in the production of cerebral ischemia models. However, successful therapies have been proven on experimental rodent stroke model, and they have often failed to be effective when tested clinically. Therefore, nonhuman primates were recommended as the ideal alternatives, owing to their similarities with the human cerebrovascular system, brain metabolism, grey to white matter ratio and even their rich behavioral repertoire. The present review is a thorough summary of ten methods that establish nonhuman primate models of focal cerebral ischemia; electrocoagulation, endothelin-1-induced occlusion, microvascular clip occlusion, autologous blood clot embolization, balloon inflation, microcatheter embolization, coil embolization, surgical suture embolization, suture, and photochemical induction methods. This review addresses the advantages and disadvantages of each method, as well as precautions for each model, compared nonhuman primates with rodents, different species of nonhuman primates and different modeling methods. Finally it discusses various factors that need to be considered when modelling and the method of evaluation after modelling. These are critical for understanding their respective strengths and weaknesses and underlie the selection of the optimum model.

  1. Evaluation of Hemodynamics in Focal Steatosis and Focal Spared Lesion of the Liver Using Contrast-Enhanced Ultrasonography with Sonazoid

    International Nuclear Information System (INIS)

    Shiozawa, K.; Watanabe, M.; Ikehara, T.; Kogame, M.; Shinohara, M.; Shinohara, M.; Ishii, K.; Igarashi, Y.; Sumino, Y.; Shiozawa, K.; Makino, H.

    2014-01-01

    We aim to investigate the hemodynamics in focal steatosis and focal spared lesion of the liver using contrast-enhanced ultrasonography (CEUS) with Sonazoid. The subjects were 47 patients with focal steatosis and focal spared lesion. We evaluated enhancement patterns (hyper enhancement, iso enhancement, and hypo enhancement) in the vascular phase and the presence or absence of a hypoechoic area in the post vascular phase for these lesions using CEUS. Of the 24 patients with focal steatosis, the enhancement pattern was iso enhancement in 19 and hypo enhancement in 5. Hypoechoic areas were noted in the post vascular phase in 3 patients. Of the 23 patients with focal spared lesions, the enhancement pattern was iso enhancement in 18 and hyper enhancement in 5. No hypoechoic areas were noted in the post vascular phase in any patient. The hemodynamics in focal steatosis and focal spared lesions in non diffuse fatty liver can be observed using low-invasive procedures in real-time by CEUS. It was suggested that differences in the dynamics of enhancement in the vascular phase of CEUS were influenced by the fat deposits in the target lesion, the surrounding liver parenchyma, and the third inflow.

  2. The impact of static stress change, dynamic stress change, and the background stress on aftershock focal mechanisms

    Science.gov (United States)

    Hardebeck, Jeanne L.

    2014-01-01

    The focal mechanisms of earthquakes in Southern California before and after four M ≥ 6.7 main shocks provide insight into how fault systems respond to stress and changes in stress. The main shock static stress changes have two observed impacts on the seismicity: changing the focal mechanisms in a given location to favor those aligned with the static stress change and changing the spatial distribution of seismicity to favor locations where the static stress change aligns with the background stress. The aftershock focal mechanisms are significantly aligned with the static stress changes for absolute stress changes of ≥ 0.02 MPa, for up to ~20 years following the main shock. The dynamic stress changes have similar, although smaller, effects on the local focal mechanisms and the spatial seismicity distribution. Dynamic stress effects are best observed at long periods (30–60 s) and for metrics based on repeated stress cycling in the same direction. This implies that dynamic triggering operates, at least in part, through cyclic shear stress loading in the direction of fault slip. The background stress also strongly controls both the preshock and aftershock mechanisms. While most aftershock mechanisms are well oriented in the background stress field, 10% of aftershocks are identified as poorly oriented outliers, which may indicate limited heterogeneity in the postmain shock stress field. The fault plane orientations of the outliers are well oriented in the background stress, while their slip directions are not, implying that the background stress restricts the distribution of available fault planes.

  3. Focal Mechanism of Semi-Volcanic Deep Low-Frequency Earthquakes in Eastern Shimane

    Science.gov (United States)

    Aso, N.; Ohta, K.; Ide, S.

    2012-12-01

    Many deep low-frequency earthquakes (LFEs) occur near the island arc Mohorovicic discontinuities and far from both active volcanoes and plate boundaries. They are quite similar to volcanic LFEs beneath active volcanoes, which infers some fluid movement in the source region, and we regard them as "semi-volcanic" LFEs [Aso et al., 2011; 2012 (submitted)]. Several previous studies determined the focal mechanisms of volcanic and semi-volcanic LFEs using a small portion of information of the waveforms. Although the estimated focal mechanisms are various, they may not necessary support the variety of the actual physical process, owing to the large determination error [e.g., Nishidomi and Takeo, 1996; Ohmi and Obara, 2002; Nakamichi et al., 2003]. Here we determine the focal mechanisms by waveform inversion for LFEs in eastern Shimane in western Japan, where many LFEs occurred in a quiet region. The locations are also close to the fault plane of the 2000 western Tottori earthquake of Mw6.6, and right beneath Yokota volcano, which is a Quaternary volcanic cluster. We estimated the focal mechanisms of semi-volcanic LFEs in eastern Shimane by moment tensor inversion. The data are velocity seismograms at five stations of Hi-net near the epicenters. For each seismogram, we extracted a 1.5-second time window beginning from 0.2 seconds before the arrivals of either P-wave in a vertical component or S-wave in a horizontal component. The arrival time of each phase is picked manually first, and then corrected to minimize the variance between observed and synthetic waveforms. The local site amplification is estimated using far-field body waves from deep intraslab earthquakes, and collected for each seismogram. The synthetic waveforms were calculated using the discrete wavenumber integration method developed by Takeo [1985] for a horizontally layered structure. For 38 LFEs, which are equal to or larger than M1.2 (JMA magnitude) and recorded at all five stations, the focal mechanisms

  4. Technology of uncooled fast polycrystalline PbSe focal plane arrays in systems for muzzle flash detection

    Science.gov (United States)

    Kastek, Mariusz; PiÄ tkowski, Tadeusz; Polakowski, Henryk; Barela, Jaroslaw; Firmanty, Krzysztof; Trzaskawka, Piotr; Vergara, German; Linares, Rodrigo; Gutierrez, Raul; Fernandez, Carlos; Montojo Supervielle, Maria Teresa

    2014-05-01

    The paper presents some aspects of muzzle flash detection using low resolution polycrystalline PbSe 32×32 and 80×80 detectors FPA operating at room temperature (uncooled performance). These sensors, which detect in MWIR (3 - 5 microns region) and are manufactured using proprietary technology from New Infrared Technologies (VPD PbSe - Vapor Phase Deposition of polycrystalline PbSe), can be applied to muzzle flash detection. The system based in the uncooled 80×80 FPA monolithically integrated with the CMOS readout circuitry has allowed image recording with frame rates over 2000 Hz (true snapshot acquisition), whereas the lower density, uncooled 32×32 FPA is suitable for being used in low cost infrared imagers sensitive in the MWIR band with frame rates above 1000 Hz. The FPA detector, read-out electronics and processing electronics (allows the implementation of some algorithms for muzzle flash detection) of both systems are presented. The systems have been tested at field test ground. Results of detection range measurement with two types of optical systems (wide and narrow field of view) have been shown. The theoretical analysis of possibility detection of muzzle flash and initial results of testing of some algorithms for muzzle flash detection have been presented too.

  5. Multi-Beam Focal Plane Arrays with Digital Beamforming for High Precision Space-Borne Ocean Remote Sensing

    DEFF Research Database (Denmark)

    Iupikov, Oleg A.; Ivashina, Mariana V.; Skou, Niels

    2018-01-01

    alternative radiometer systems: a conical scanner with an off-set parabolic reflector, and stationary wide-scan torus reflector system; each operating at C, X and Ku bands. Numerical results predict excellent beam performance for both systems with as low as 0:14 % total received power over the land.......The present-day ocean remote sensing instruments that operate at low microwave frequencies are limited in spatial resolution and do not allow for monitoring of the coastal waters. This is due the difficulties of employing a large reflector antenna on a satellite platform, and generating high-quality...

  6. Infrared Imaging of Cotton Fiber Bundles Using a Focal Plane Array Detector and a Single Reflectance Accessory

    Directory of Open Access Journals (Sweden)

    Michael Santiago Cintrón

    2016-11-01

    Full Text Available Infrared imaging is gaining attention as a technique used in the examination of cotton fibers. This type of imaging combines spectral analysis with spatial resolution to create visual images that examine sample composition and distribution. Herein, we report on the use of an infrared instrument equipped with a reflection accessory and an array detector system for the examination of cotton fiber bundles. Cotton vibrational spectra and chemical images were acquired by grouping pixels in the detector array. This technique reduced spectral noise and was employed to visualize cell wall development in cotton fibers bundles. Fourier transform infrared spectra reveal band changes in the C–O bending region that matched previous studies. Imaging studies were quick, relied on small amounts of sample and provided a distribution of the cotton fiber cell wall composition. Thus, imaging of cotton bundles with an infrared detector array has potential for use in cotton fiber examinations.

  7. A Collaborative Knowledge Plane for Autonomic Networks

    Science.gov (United States)

    Mbaye, Maïssa; Krief, Francine

    Autonomic networking aims to give network components self-managing capabilities. Several autonomic architectures have been proposed. Each of these architectures includes sort of a knowledge plane which is very important to mimic an autonomic behavior. Knowledge plane has a central role for self-functions by providing suitable knowledge to equipment and needs to learn new strategies for more accuracy.However, defining knowledge plane's architecture is still a challenge for researchers. Specially, defining the way cognitive supports interact each other in knowledge plane and implementing them. Decision making process depends on these interactions between reasoning and learning parts of knowledge plane. In this paper we propose a knowledge plane's architecture based on machine learning (inductive logic programming) paradigm and situated view to deal with distributed environment. This architecture is focused on two self-functions that include all other self-functions: self-adaptation and self-organization. Study cases are given and implemented.

  8. An efficient global energy optimization approach for robust 3D plane segmentation of point clouds

    Science.gov (United States)

    Dong, Zhen; Yang, Bisheng; Hu, Pingbo; Scherer, Sebastian

    2018-03-01

    Automatic 3D plane segmentation is necessary for many applications including point cloud registration, building information model (BIM) reconstruction, simultaneous localization and mapping (SLAM), and point cloud compression. However, most of the existing 3D plane segmentation methods still suffer from low precision and recall, and inaccurate and incomplete boundaries, especially for low-quality point clouds collected by RGB-D sensors. To overcome these challenges, this paper formulates the plane segmentation problem as a global energy optimization because it is robust to high levels of noise and clutter. First, the proposed method divides the raw point cloud into multiscale supervoxels, and considers planar supervoxels and individual points corresponding to nonplanar supervoxels as basic units. Then, an efficient hybrid region growing algorithm is utilized to generate initial plane set by incrementally merging adjacent basic units with similar features. Next, the initial plane set is further enriched and refined in a mutually reinforcing manner under the framework of global energy optimization. Finally, the performances of the proposed method are evaluated with respect to six metrics (i.e., plane precision, plane recall, under-segmentation rate, over-segmentation rate, boundary precision, and boundary recall) on two benchmark datasets. Comprehensive experiments demonstrate that the proposed method obtained good performances both in high-quality TLS point clouds (i.e., http://SEMANTIC3D.NET)

  9. Radioactivity in the galactic plane

    Science.gov (United States)

    Walraven, G. D.; Haymes, R. C.

    1976-01-01

    The paper reports the detection of a large concentration of interstellar radioactivity during balloon-altitude measurements of gamma-ray energy spectra in the band between 0.02 and 12.27 MeV from galactic and extragalactic sources. Enhanced counting rates were observed in three directions towards the plane of the Galaxy; a power-law energy spectrum is computed for one of these directions (designated B 10). A large statistical deviation from the power law in a 1.0-FWHM interval centered near 1.16 MeV is discussed, and the existence of a nuclear gamma-ray line at 1.15 MeV in B 10 is postulated. It is suggested that Ca-44, which emits gamma radiation at 1.156 MeV following the decay of radioactive Sc-44, is a likely candidate for this line, noting that Sc-44 arises from Ti-44 according to explosive models of supernova nucleosynthesis. The 1.16-MeV line flux inferred from the present data is shown to equal the predicted flux for a supernova at a distance of approximately 3 kpc and an age not exceeding about 100 years.

  10. Compact planes, mostly 8-dimensional. A retrospect

    OpenAIRE

    Salzmann, Helmut R.

    2014-01-01

    Results on $8$-dimensional topological planes are scattered in the literature. It is the aim of the present paper to give a survey of these geometries, in particular of information obtained after the appearance of the treatise Compact Projective Planes or not included in this book. For some theorems new proofs are given and a few related results concerning planes of other dimensions are presented.

  11. Focal Atrichia: A Diagnostic Clue in Female Pattern Hair Loss.

    Science.gov (United States)

    Olsen, Elise A; Whiting, David A

    2017-10-07

    Focal atrichia is a common clinical finding in female pattern hair loss whose specificity and histologic findings need further clarification. To determine the frequency of focal atrichia in various types of hair loss and its histologic characteristics in female pattern hair loss. Part 1: Review of 250 consecutive female patients seen with hair loss for the presence of focal atrichia and Part 2: paired biopsies of haired areas vs focal atrichia in 18 subjects with female pattern hair loss RESULTS: Focal atrichia was seen in 46/104 (44%) of women with female pattern hair loss, including 67% of late onset vs 15% of early onset, compared to 3/146 (2%) of those with other hair disorders Biopsy findings of focal atrichia in female pattern hair loss showed primarily a more progressive miniaturization process than that of haired areas of the scalp. Some women with female pattern hair loss may have had concomitant chronic telogen effluvium CONCLUSIONS: When present, focal atrichia is a clinical clue to the diagnosis of female pattern hair loss, particularly late onset subtype. Copyright © 2017. Published by Elsevier Inc.

  12. The semiology of febrile seizures: Focal features are frequent.

    Science.gov (United States)

    Takasu, Michihiko; Kubota, Tetsuo; Tsuji, Takeshi; Kurahashi, Hirokazu; Numoto, Shingo; Watanabe, Kazuyoshi; Okumura, Akihisa

    2017-08-01

    To clarify the semiology of febrile seizures (FS) and to determine the frequency of FS with symptoms suggestive of focal onset. FS symptoms in children were reported within 24h of seizure onset by the parents using a structured questionnaire consisting principally of closed-ended questions. We focused on events at seizure commencement, including changes in behavior and facial expression, and ocular and oral symptoms. We also investigated the autonomic and motor symptoms developing during seizures. The presence or absence of focal and limbic features was determined for each patient. The associations of certain focal and limbic features with patient characteristics were assessed. Information was obtained on FS in 106 children. Various events were recorded at seizure commencement. Behavioral changes were observed in 35 children, changes in facial expression in 53, ocular symptoms in 78, and oral symptoms in 90. In terms of events during seizures, autonomic symptoms were recognized in 78, and convulsive motor symptoms were recognized in 68 children. Focal features were evident in 81 children; 38 children had two or more such features. Limbic features were observed in 44 children, 9 of whom had two or more such features. There was no significant relationship between any patient characteristic and the numbers of focal or limbic features. The semiology of FS varied widely among children, and symptoms suggestive of focal onset were frequent. FS of focal onset may be more common than is generally thought. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. The dispersion-focalization theory of sound systems

    Science.gov (United States)

    Schwartz, Jean-Luc; Abry, Christian; Boë, Louis-Jean; Vallée, Nathalie; Ménard, Lucie

    2005-04-01

    The Dispersion-Focalization Theory states that sound systems in human languages are shaped by two major perceptual constraints: dispersion driving auditory contrast towards maximal or sufficient values [B. Lindblom, J. Phonetics 18, 135-152 (1990)] and focalization driving auditory spectra towards patterns with close neighboring formants. Dispersion is computed from the sum of the inverse squared inter-spectra distances in the (F1, F2, F3, F4) space, using a non-linear process based on the 3.5 Bark critical distance to estimate F2'. Focalization is based on the idea that close neighboring formants produce vowel spectra with marked peaks, easier to process and memorize in the auditory system. Evidence for increased stability of focal vowels in short-term memory was provided in a discrimination experiment on adult French subjects [J. L. Schwartz and P. Escudier, Speech Comm. 8, 235-259 (1989)]. A reanalysis of infant discrimination data shows that focalization could well be the responsible for recurrent discrimination asymmetries [J. L. Schwartz et al., Speech Comm. (in press)]. Recent data about children vowel production indicate that focalization seems to be part of the perceptual templates driving speech development. The Dispersion-Focalization Theory produces valid predictions for both vowel and consonant systems, in relation with available databases of human languages inventories.

  14. Nanostructured carbon films with oriented graphitic planes

    International Nuclear Information System (INIS)

    Teo, E. H. T.; Kalish, R.; Kulik, J.; Kauffmann, Y.; Lifshitz, Y.

    2011-01-01

    Nanostructured carbon films with oriented graphitic planes can be deposited by applying energetic carbon bombardment. The present work shows the possibility of structuring graphitic planes perpendicular to the substrate in following two distinct ways: (i) applying sufficiently large carbon energies for deposition at room temperature (E>10 keV), (ii) utilizing much lower energies for deposition at elevated substrate temperatures (T>200 deg. C). High resolution transmission electron microscopy is used to probe the graphitic planes. The alignment achieved at elevated temperatures does not depend on the deposition angle. The data provides insight into the mechanisms leading to the growth of oriented graphitic planes under different conditions.

  15. Lower incisor inclination regarding different reference planes.

    Science.gov (United States)

    Zataráin, Brenda; Avila, Josué; Moyaho, Angeles; Carrasco, Rosendo; Velasco, Carmen

    2016-09-01

    The purpose of this study was to assess the degree of lower incisor inclination with respect to different reference planes. It was an observational, analytical, longitudinal, prospective study conducted on 100 lateral cephalograms which were corrected according to the photograph in natural head position in order to draw the true vertical plane (TVP). The incisor mandibular plane angle (IMPA) was compensated to eliminate the variation of the mandibular plane growth type with the formula "FMApx.- 25 (FMA) + IMPApx. = compensated IMPA (IMPACOM)". As the data followed normal distribution determined by the KolmogorovSmirnov test, parametric tests were used for the statistical analysis, Ttest, ANOVA and Pearson coefficient correlation test. Statistical analysis was performed using a statistical significance of p planes. There were statistically significant differences among the means of the planes measured, except for IMPACOM, FMIA and TVP. The IMPA differed significantly from the IMPACOM. The compensated IMPA and the FMIA did not differ significantly from the TVP. The true horizontal plane was mismatched with Frankfort plane in 84% of the sample with a range of 19°. The true vertical plane is adequate for measuring lower incisor inclination. Sociedad Argentina de Investigación Odontológica.

  16. Widespread EEG changes precede focal seizures.

    Directory of Open Access Journals (Sweden)

    Piero Perucca

    Full Text Available The process by which the brain transitions into an epileptic seizure is unknown. In this study, we investigated whether the transition to seizure is associated with changes in brain dynamics detectable in the wideband EEG, and whether differences exist across underlying pathologies. Depth electrode ictal EEG recordings from 40 consecutive patients with pharmacoresistant lesional focal epilepsy were low-pass filtered at 500 Hz and sampled at 2,000 Hz. Predefined EEG sections were selected immediately before (immediate preictal, and 30 seconds before the earliest EEG sign suggestive of seizure activity (baseline. Spectral analysis, visual inspection and discrete wavelet transform were used to detect standard (delta, theta, alpha, beta and gamma and high-frequency bands (ripples and fast ripples. At the group level, each EEG frequency band activity increased significantly from baseline to the immediate preictal section, mostly in a progressive manner and independently of any modification in the state of vigilance. Preictal increases in each frequency band activity were widespread, being observed in the seizure-onset zone and lesional tissue, as well as in remote regions. These changes occurred in all the investigated pathologies (mesial temporal atrophy/sclerosis, local/regional cortical atrophy, and malformations of cortical development, but were more pronounced in mesial temporal atrophy/sclerosis. Our findings indicate that a brain state change with distinctive features, in the form of unidirectional changes across the entire EEG bandwidth, occurs immediately prior to seizure onset. We postulate that these changes might reflect a facilitating state of the brain which enables a susceptible region to generate seizures.

  17. Focal Segmental Glomerulosclerosis: A Single Center Experience

    Directory of Open Access Journals (Sweden)

    Yavuz Ayar

    2016-09-01

    Full Text Available Aim: Focal segmental glomerulosclerosis (FSGS is one of the most common glomerulonephritis (GNP worldwide. Despite treatment, it may progress to end-stage renal disease. In the present study, we compared clinical and histopathological data on FSGS with primary and secondary GNP retrospectively. Methods: We retrospectively analyzed data on clinical and laboratory findings, treatment response, and risk factors associated with mortality in patients, who had been diagnosed with FSGS and other GNP via renal biopsy between January 2009 and December 2014. The average follow-up time was 22 (8-76 months. Results: FSGS and primary GNP were more frequently seen in males than in females (55.9% vs. 65.3%, p=0.033. Nephrotic syndrome was more common in patients with FSGS (41.2% and primary GNP (57.7%, while chronic renal disease was more frequent in patients with secondary GNP (35%. In FSGS, the complete remission rate was 54.4%. 63.2% of patients had continued to receive treatment. According to the biopsy findings, interstitial inflammation and fibrosis were observed in 100% and 98.5% of patients with FSGS, respectively (p=0.010 and p<0.001, respectively. Serum albumin level was found to be increased and proteinuria, total cholesterol, triglyceride, and LDL levels to be decreased after treatment (p<0.001. Serum creatinine levels and type of GNP (secondary GNP were detected to be 1.48 and 8.14 fold increased in mortality analysis, respectively. Conclusion: Renal biopsy is the gold standard for the diagnosis of glomerular diseases. Renal function at the time of diagnosis, follow-up and appropriate immunosuppressive therapy have effects on mortality and clinical progress in FSGS as is the case in all GNPs.

  18. Image-guided focal therapies for breast cancer

    International Nuclear Information System (INIS)

    Marqa, Mohamad-Feras

    2011-01-01

    Breast cancer is the most common in women, affecting one in ten women, by geographic area. Accelerated Partial Breast Irradiation (APBI) is a new concept of postoperative irradiation after breast conserving surgery for cancer at low risk of local recurrence. In the first chapter of this thesis, we present the rational use of the APBI method as an alternative to the whole breast irradiation and then we discuss the principles, the benefits, and the drawbacks of the different techniques used. One of these techniques is the multi catheters high dose rate (HDR) interstitial brachytherapy. Multi catheter interstitial brachytherapy was the originally employed APBI technique and as a consequence has generated clinical experience with the longest follow-up duration, and with encouraging results. The accuracy of treatment planning system (TPS) in the source location and the dose calculation is absolutely necessary to ensure the planned dose. Sievert Integral and TG43 formalism provide quick and easy methods to check and to verify the dose calculated by the TPS. In the second chapter, we discuss a dose calculation and optimization tool for the APBI method using HDR sources. This tool simulates the dose from the parameters defined by the physicist. Often, the radiotherapist performs during the procedure a mental re-adjustment of catheters positions simulated on the CT images. This operation could lead to errors due to differences in breast form and catheters positions on the intra-operative ultrasound images compared to the planed one on CT images. In chapter three of this thesis, we propose a registration method between data from planning and the one from intra-operative ultrasound images as a solution that will allow to the radiotherapist to report planning data automatically on the brachytherapy template to visualize all data on the computer monitor. The APBI technique is considered an invasive and expensive method due to radiation protection reasons. Laser Interstitial

  19. Focal Length Affects Depicted Shape and Perception of Facial Images.

    Directory of Open Access Journals (Sweden)

    Vít Třebický

    Full Text Available Static photographs are currently the most often employed stimuli in research on social perception. The method of photograph acquisition might affect the depicted subject's facial appearance and thus also the impression of such stimuli. An important factor influencing the resulting photograph is focal length, as different focal lengths produce various levels of image distortion. Here we tested whether different focal lengths (50, 85, 105 mm affect depicted shape and perception of female and male faces. We collected three portrait photographs of 45 (22 females, 23 males participants under standardized conditions and camera setting varying only in the focal length. Subsequently, the three photographs from each individual were shown on screen in a randomized order using a 3-alternative forced-choice paradigm. The images were judged for attractiveness, dominance, and femininity/masculinity by 369 raters (193 females, 176 males. Facial width-to-height ratio (fWHR was measured from each photograph and overall facial shape was analysed employing geometric morphometric methods (GMM. Our results showed that photographs taken with 50 mm focal length were rated as significantly less feminine/masculine, attractive, and dominant compared to the images taken with longer focal lengths. Further, shorter focal lengths produced faces with smaller fWHR. Subsequent GMM revealed focal length significantly affected overall facial shape of the photographed subjects. Thus methodology of photograph acquisition, focal length in this case, can significantly affect results of studies using photographic stimuli perhaps due to different levels of perspective distortion that influence shapes and proportions of morphological traits.

  20. Colliding almost-plane gravitational waves: Colliding plane waves and general properties of almost-plane-wave spacetimes

    International Nuclear Information System (INIS)

    Yurtsever, U.

    1988-01-01

    It is well known that when two precisely plane-symmetric gravitational waves propagating in an otherwise flat background collide, they focus each other so strongly as to produce a curvature singularity. This paper is the first of several devoted to almost-plane gravitational waves and their collisions. Such waves are more realistic than plane waves in having a finite but very large transverse size. In this paper we review some crucial features of the well-known exact solutions for colliding plane waves and we argue that one of these features, the breakdown of ''local inextendibility'' can be regarded as nongeneric. We then introduce a new framework for analyzing general colliding plane-wave spacetimes; we give an alternative proof of a theorem due to Tipler implying the existence of singularities in all generic colliding plane-wave solutions; and we discuss the fact that the recently constructed Chandrasekhar-Xanthopoulos colliding plane-wave solutions are not strictly plane symmetric and thus do not satisfy the conditions and the conclusion of Tipler's theorem

  1. The design of LMJ focal spots for indirect drive experiments

    International Nuclear Information System (INIS)

    Le Garrec, B J; Sajer, J M

    2008-01-01

    LMJ is a 240 high power laser beam facility for achieving laser matter interaction experiments, high energy density science, including the demonstration of fusion ignition through Inertial Confinement. The Laser Integration Line (LIL) facility is currently a 4-beam prototype for LMJ. The intensity I 0 at the focal spot centre drives hydrodynamic and plasma instabilities and the intensity in the wings must be low to go through the laser entrance Hohlraum. A simple model has been developed to compute the LMJ focal spot. The model gives the intensity at the centre as a function of the focal spot area at 3% of the maximum

  2. Focal cemento-osseous dysplasia: review and a case report.

    Science.gov (United States)

    Salem, Y M Y; Osman, Y I; Norval, E J G

    2010-10-01

    Focal cemento-osseous dysplasia is a benign fibro-osseous condition that can be seen in dentate and edentulous patients. It is an asymptomatic lesion and needs no treatment; however follow-up is essential due to the possibility that focal cemento-osseous dysplasia can progress to a condition called florid osseous dysplasia that involves multiple sites. A case report is presented here, along with a review of the differential diagnoses considered in order to reach a final diagnosis of focal cemento-osseous dysplasia.

  3. Benign focal liver lesions: discrimination from malignant mimickers.

    Science.gov (United States)

    Alobaidi, Mohammad; Shirkhoda, Ali

    2004-01-01

    Focal lesions of the liver often have various imaging characteristics which may be interpreted as either benign or malignant. Understanding the underlying pathophysiology of these liver lesions may lead to characteristic imaging manifestations, which direct the radiologist to the diagnosis. Benign lesions include congenital hepatic cyst, autosomal dominant polycystic disease, hemangioma, focal nodular hyperplasia (FNH), hepatic adenoma, inflammatory pseudotumor, peliosis hepatis, focal fatty infiltration, hamartoma, and infectious processes such as hepatic abscess, echinococcal cyst, and candidiasis. Characteristic imaging features, clinical symptoms, and treatment/prognosis will be discussed. Emphasis will be placed on key reliable features of each disease to develop a method of discriminating these lesions from other benign and malignant disorders.

  4. Hybrid stars

    Indian Academy of Sciences (India)

    Hybrid stars. AsHOK GOYAL. Department of Physics and Astrophysics, University of Delhi, Delhi 110 007, India. Abstract. Recently there have been important developments in the determination of neutron ... number and the electric charge. ... available to the system to rearrange concentration of charges for a given fraction of.

  5. Discretization of superintegrable systems on a plane

    Science.gov (United States)

    Kabát, Z.

    2012-02-01

    We construct difference analogues of so called Smorodinsky-Winternitz superintegrable systems in the Euclidean plane. Using methods of umbral calculus, we obtain difference equations for generalized isotropic harmonic oscillator on the uniform lattice, and also its solution in terms of power series. In the case of gauge-rotated Hamiltonian, the solution is a polynomial, well-defined in the whole plane.

  6. Slipping and Rolling on an Inclined Plane

    Science.gov (United States)

    Aghamohammadi, Cina; Aghamohammadi, Amir

    2011-01-01

    In the first part of the paper, using a direct calculation two-dimensional motion of a particle sliding on an inclined plane is investigated for general values of friction coefficient ([mu]). A parametric equation for the trajectory of the particle is also obtained. In the second part of the paper, the motion of a sphere on the inclined plane is…

  7. Moving vertices to make drawings plane

    NARCIS (Netherlands)

    Goaoc, X.; Kratochvil, J.; Okamoto, Y.; Shin, C.S.; Wolff, A.; Hong, S.K.; Nishizeki, T.; Quan, W.

    2008-01-01

    In John Tantalo’s on-line game Planarity the player is given a non-plane straight-line drawing of a planar graph. The aim is to make the drawing plane as quickly as possible by moving vertices. In this paper we investigate the related problem MinMovedVertices which asks for the minimum number of

  8. DEPDC5 takes a second hit in familial focal epilepsy.

    Science.gov (United States)

    Anderson, Matthew P

    2018-04-30

    Loss-of-function mutations in a single allele of the gene encoding DEP domain-containing 5 protein (DEPDC5) are commonly linked to familial focal epilepsy with variable foci; however, a subset of patients presents with focal cortical dysplasia that is proposed to result from a second-hit somatic mutation. In this issue of the JCI, Ribierre and colleagues provide several lines of evidence to support second-hit DEPDC5 mutations in this disorder. Moreover, the authors use in vivo, in utero electroporation combined with CRISPR-Cas9 technology to generate a murine model of the disease that recapitulates human manifestations, including cortical dysplasia-like changes, focal seizures, and sudden unexpected death. This study provides important insights into familial focal epilepsy and provides a preclinical model for evaluating potential therapies.

  9. Focal myositis of lower extremity responsive to botulinum A toxin.

    Science.gov (United States)

    Mitrovic, Josko; Prka, Zeljko; Zic, Rado; Marusic, Srecko; Morovic-Vergles, Jadranka

    2014-01-01

    Focal myositis is a rare, mostly benign disease (pseudotumor) of skeletal muscle, histopathologically characterized by interstitial myositis and tumorous enlargement of a single muscle. The etiology of focal myositis remains unknown; however, localized myopathy has been postulated to be caused by denervation lesions. This case report describes a patient that presented with clinical, laboratory, electromyoneurography, and magnetic resonance imaging features of focal myositis complicated with intervertebral disk protrusion in the lumbosacral spine affected with radicular distress. In most cases, focal myositic lesions show spontaneous regression, relapses are rare, and long-term prognosis is good. There is a wide spectrum of therapeutic options, from no therapy at all through nonsteroidal antirheumatics and glucocorticoids to radiotherapy, surgical excision, and immunosuppressants. In the patient presented, treatment with glucocorticoids, methotrexate, and surgical excision failed to produce satisfactory results. Clinical improvement, pain relief, and reduction in lower leg volume were only achieved by local infiltration of botulinum A toxin.

  10. Mechanical design and analysis of focal plate for gravity deformation

    Science.gov (United States)

    Wang, Jianping; Chu, Jiaru; Hu, Hongzhuan; Li, Kexuan; Zhou, Zengxiang

    2014-07-01

    The surface accuracy of astronomical telescope focal plate is a key indicator to precision stellar observation. To conduct accurate deformation measurement for focal plate in different status, a 6-DOF hexapod platform was used for attitude adjustment. For the small adjustment range of a classic 6-DOF hexapod platform, an improved structural arrangement method was proposed in the paper to achieve ultimate adjustment of the focal plate in horizontal and vertical direction. To validate the feasibility of this method, an angle change model which used ball hinge was set up for the movement and base plate. Simulation results in MATLAB suggested that the ball hinge angle change of movement and base plate is within the range of the limiting angle in the process of the platform plate adjusting to ultimate attitude. The proposed method has some guiding significance for accurate surface measurement of focal plate.

  11. FOCAL CORTICAL DYSPLASIAS: CLINICAL AND ELECTRO-NEUROIMAGING CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    K. Yu. Mukhin

    2016-01-01

    Full Text Available In spite of a notable advance made in epileptology, resistant epilepsies account for approximately 30 % of all forms of epilepsy particularly in patients with focal seizures. One of the main causes of therapy-resistant focal epilepsies is focal cortical dysplasias (FCD. This term was first introduced by D. Taylor et al. in 1971. FCD belongs to abnormal cortical development. Among all abnormalities of cortical development, FCD in surgically treated children amounts to 75 %. FCD is the most common cause of resistant epilepsy in children and the most frequent reason for diagnosing cryptogenic focal epilepsy with intractable seizures. The author gives a detailed literature review dedicated to FCD as a cause of resistant epilepsy, including the classification and histologic characteristics of FCD, its clinical manifestations and prognosis, and approaches to medical and surgical treatments. 

  12. Electrocorticographic discharge patterns in glioneuronal tumors and focal cortical dysplasia

    NARCIS (Netherlands)

    Ferrier, Cyrille H.; Aronica, Eleanora; Leijten, Frans S. S.; Spliet, Wim G. M.; van Huffelen, Alexander C.; van Rijen, Peter C.; Binnie, Colin D.

    2006-01-01

    PURPOSE: To determine whether highly epileptiform electrocorticographical discharge patterns occur in patients with glioneuronal tumors (GNTs) and focal cortical dysplasia (FCD) and whether specific histopathological features are related to such patterns. METHODS: The series consists of operated

  13. Open Cluster Dynamics via Fundamental Plane

    Science.gov (United States)

    Lin, Chien-Cheng; Pang, Xiao-Ying

    2018-04-01

    Open clusters (OCs) are important objects for stellar dynamics studies. The short survival timescale of OCs makes them closely related to the formation of Galactic field stars. We motivate to investigate the dynamical evolution of OCs on the aspect of internal effect and the external influence. Firstly, we make use of the known OC catalog to obtain OCs masses, effective radii. Additionally, we estimate OCs kinematics properties by OC members cross-matched with radial velocity and metallicity from SDSSIV/APOGEE2. We then establish the fundamental plane of OCs based on the radial velocity dispersion, the effective radius, and average surface brightness. The deviation of the fundamental plane from the Virial Plane, so called the tilt, and the r.m.s. dispersion of OCs around the average plane are used to indicate the dynamical status of OCs. Parameters of the fitted plane will vary with cluster age and distance.

  14. Slipping and rolling on an inclined plane

    International Nuclear Information System (INIS)

    Aghamohammadi, Cina; Aghamohammadi, Amir

    2011-01-01

    In the first part of the paper, using a direct calculation two-dimensional motion of a particle sliding on an inclined plane is investigated for general values of friction coefficient (μ). A parametric equation for the trajectory of the particle is also obtained. In the second part of the paper, the motion of a sphere on the inclined plane is studied. It is shown that the evolution equation for the contact point of a sliding sphere is similar to that of a point particle sliding on an inclined plane whose friction coefficient is 7/2 μ. If μ > 2/7 tan θ, for any arbitrary initial velocity and angular velocity, the sphere will roll on the inclined plane after some finite time. In other cases, it will slip on the inclined plane. In the case of rolling, the centre of the sphere moves on a parabola. Finally the velocity and angular velocity of the sphere are exactly computed.

  15. Coherent field propagation between tilted planes.

    Science.gov (United States)

    Stock, Johannes; Worku, Norman Girma; Gross, Herbert

    2017-10-01

    Propagating electromagnetic light fields between nonparallel planes is of special importance, e.g., within the design of novel computer-generated holograms or the simulation of optical systems. In contrast to the extensively discussed evaluation between parallel planes, the diffraction-based propagation of light onto a tilted plane is more burdensome, since discrete fast Fourier transforms cannot be applied directly. In this work, we propose a quasi-fast algorithm (O(N 3  log N)) that deals with this problem. Based on a proper decomposition into three rotations, the vectorial field distribution is calculated on a tilted plane using the spectrum of plane waves. The algorithm works on equidistant grids, so neither nonuniform Fourier transforms nor an explicit complex interpolation is necessary. The proposed algorithm is discussed in detail and applied to several examples of practical interest.

  16. Adult-onset Rasmussen encephalitis associated with focal cortical dysplasia.

    Science.gov (United States)

    Hohenbichler, Katharina; Lelotte, Julie; Lhommel, Renaud; Tahry, Riëm El; Vrielynck, Pascal; Santos, Susana Ferrao

    2017-12-01

    Rasmussen encephalitis is a rare, devastating condition, typically presenting in childhood. Cases of adult-onset Rasmussen have also been described, but the clinical picture is less defined, rendering final diagnosis difficult. We present a case of adult-onset Rasmussen encephalitis with dual pathology, associated with focal cortical dysplasia and encephalitis. We interpreted the Rasmussen encephalitis to be caused by severe and continuous epileptic activity due to focal cortical dysplasia. The best therapeutic approach for such cases remains unclear.

  17. Study the Z-Plane Strip Capacitance

    International Nuclear Information System (INIS)

    Parikh, H.; Swain, S.

    2005-01-01

    The BaBaR detector at the Stanford Linear Accelerator Center is currently undergoing an upgrade to improve its muon and neutral hadron detection system. The Resistive Plate Chambers (RPCs) that had been used till now have deteriorated in performance over the past few years and are being replaced by Limited Streamer Tube (LSTs). Each layer of the system consists of a set of up to 10 streamer tube modules which provide one coordinate (φ coordinate) and a single ''Z-plane'' which provides the Z coordinate of the hit. The large area Z-planes (up to 12m 2 ) are 1mm thick and contain 96 copper strips that detect the induced charge from avalanches created in the streamer tube wires. All the Z-planes needed for the upgrade have already been constructed, but only a third of the planes were installed last summer. After installing the 24 Z-planes last year, it was learned that 0.7% of the strips were dead when put inside the detector. This was mainly due to the delicate solder joint between the read-out cable and the strip, and since it is difficult to access or replace the Z-planes inside the detector, it is very important to perform various tests to make sure that the Z-planes will be efficient and effective in the long term. We measure the capacitance between the copper strips and the ground plane, and compare it to the theoretical value that we expect. Instead of measuring the capacitance channel by channel, which would be a very tedious job, we developed a more effective method of measuring the capacitance. Since all the Z-planes were built at SLAC, we also built a smaller 46 cm by 30 cm Z-plane with 12 strips just to see how they were constructed and to gain a better understanding about the solder joints

  18. Focal cortical malformations in children with early infantile epilepsy and PCDH19 mutations: case report.

    Science.gov (United States)

    Kurian, Mary; Korff, Christian M; Ranza, Emmanuelle; Bernasconi, Andrea; Lübbig, Anja; Nangia, Srishti; Ramelli, Gian Paolo; Wohlrab, Gabriele; Nordli, Douglas R; Bast, Thomas

    2018-01-01

    In this case report we assess the occurrence of cortical malformations in children with early infantile epilepsy associated with variants of the gene protocadherin 19 (PCDH19). We describe the clinical course, and electrographic, imaging, genetic, and neuropathological features in a cohort of female children with pharmacoresistant epilepsy. All five children (mean age 10y) had an early onset of epilepsy during infancy and a predominance of fever sensitive seizures occurring in clusters. Cognitive impairment was noted in four out of five patients. Radiological evidence of cortical malformations was present in all cases and, in two patients, validated by histology. Sanger sequencing and Multiplex Ligation-dependent Probe Amplification analysis of PCDH19 revealed pathogenic variants in four patients. In one patient, array comparative genomic hybridization showed a microdeletion encompassing PCDH19. We propose molecular testing and analysis of PCDH19 in patients with pharmacoresistant epilepsy, with onset in early infancy, seizures in clusters, and fever sensitivity. Structural lesions are to be searched in patients with PCDH19 pathogenic variants. Further, PCDH19 analysis should be considered in epilepsy surgery evaluation even in the presence of cerebral structural lesions. Focal cortical malformations and monogenic epilepsy syndromes may coexist. Structural lesions are to be searched for in patients with protocadherin 19 (PCDH19) pathogenic variants with refractory focal seizures. © 2017 Mac Keith Press.

  19. Information transmission on hybrid networks

    Science.gov (United States)

    Chen, Rongbin; Cui, Wei; Pu, Cunlai; Li, Jie; Ji, Bo; Gakis, Konstantinos; Pardalos, Panos M.

    2018-01-01

    Many real-world communication networks often have hybrid nature with both fixed nodes and moving modes, such as the mobile phone networks mainly composed of fixed base stations and mobile phones. In this paper, we discuss the information transmission process on the hybrid networks with both fixed and mobile nodes. The fixed nodes (base stations) are connected as a spatial lattice on the plane forming the information-carrying backbone, while the mobile nodes (users), which are the sources and destinations of information packets, connect to their current nearest fixed nodes respectively to deliver and receive information packets. We observe the phase transition of traffic load in the hybrid network when the packet generation rate goes from below and then above a critical value, which measures the network capacity of packets delivery. We obtain the optimal speed of moving nodes leading to the maximum network capacity. We further improve the network capacity by rewiring the fixed nodes and by considering the current load of fixed nodes during packets transmission. Our purpose is to optimize the network capacity of hybrid networks from the perspective of network science, and provide some insights for the construction of future communication infrastructures.

  20. Inter-plane artifact suppression in tomosynthesis using 3D CT image data

    Directory of Open Access Journals (Sweden)

    Kim Jae G

    2011-12-01

    Full Text Available Abstract Background Despite its superb lateral resolution, flat-panel-detector (FPD based tomosynthesis suffers from low contrast and inter-plane artifacts caused by incomplete cancellation of the projection components stemming from outside the focal plane. The incomplete cancellation of the projection components, mostly due to the limited scan angle in the conventional tomosynthesis scan geometry, often makes the image contrast too low to differentiate the malignant tissues from the background tissues with confidence. Methods In this paper, we propose a new method to suppress the inter-plane artifacts in FPD-based tomosynthesis. If 3D whole volume CT images are available before the tomosynthesis scan, the CT image data can be incorporated into the tomosynthesis image reconstruction to suppress the inter-plane artifacts, hence, improving the image contrast. In the proposed technique, the projection components stemming from outside the region-of-interest (ROI are subtracted from the measured tomosynthesis projection data to suppress the inter-plane artifacts. The projection components stemming from outside the ROI are calculated from the 3D whole volume CT images which usually have lower lateral resolution than the tomosynthesis images. The tomosynthesis images are reconstructed from the subtracted projection data which account for the x-ray attenuation through the ROI. After verifying the proposed method by simulation, we have performed both CT scan and tomosynthesis scan on a phantom and a sacrificed rat using a FPD-based micro-CT. Results We have measured contrast-to-noise ratio (CNR from the tomosynthesis images which is an indicator of the residual inter-plane artifacts on the focal-plane image. In both cases of the simulation and experimental imaging studies of the contrast evaluating phantom, CNRs have been significantly improved by the proposed method. In the rat imaging also, we have observed better visual contrast from the tomosynthesis

  1. Inter-plane artifact suppression in tomosynthesis using 3D CT image data

    Science.gov (United States)

    2011-01-01

    Background Despite its superb lateral resolution, flat-panel-detector (FPD) based tomosynthesis suffers from low contrast and inter-plane artifacts caused by incomplete cancellation of the projection components stemming from outside the focal plane. The incomplete cancellation of the projection components, mostly due to the limited scan angle in the conventional tomosynthesis scan geometry, often makes the image contrast too low to differentiate the malignant tissues from the background tissues with confidence. Methods In this paper, we propose a new method to suppress the inter-plane artifacts in FPD-based tomosynthesis. If 3D whole volume CT images are available before the tomosynthesis scan, the CT image data can be incorporated into the tomosynthesis image reconstruction to suppress the inter-plane artifacts, hence, improving the image contrast. In the proposed technique, the projection components stemming from outside the region-of-interest (ROI) are subtracted from the measured tomosynthesis projection data to suppress the inter-plane artifacts. The projection components stemming from outside the ROI are calculated from the 3D whole volume CT images which usually have lower lateral resolution than the tomosynthesis images. The tomosynthesis images are reconstructed from the subtracted projection data which account for the x-ray attenuation through the ROI. After verifying the proposed method by simulation, we have performed both CT scan and tomosynthesis scan on a phantom and a sacrificed rat using a FPD-based micro-CT. Results We have measured contrast-to-noise ratio (CNR) from the tomosynthesis images which is an indicator of the residual inter-plane artifacts on the focal-plane image. In both cases of the simulation and experimental imaging studies of the contrast evaluating phantom, CNRs have been significantly improved by the proposed method. In the rat imaging also, we have observed better visual contrast from the tomosynthesis images reconstructed by

  2. The effect of lower-hybrid waves on the propagation of hydromagnetic waves

    International Nuclear Information System (INIS)

    Hamabata, Hiromitsu; Namikawa, Tomikazu; Mori, Kazuhiro

    1988-01-01

    Propagation characteristics of hydromagnetic waves in a magnetic plasma are investigated using the two-plasma fluid equations including the effect of lower-hybrid waves propagating perpendicularly to the magnetic field. The effect of lower-hybrid waves on the propagation of hydromagnetic waves is analysed in terms of phase speed, growth rate, refractive index, polarization and the amplitude relation between the density perturbation and the magnetic-field perturbation for the cases when hydromagnetic waves propagate in the plane whose normal is perpendicular to both the magnetic field and the propagation direction of lower-hybrid waves and in the plane perpendicular to the propagation direction of lower-hybrid waves. It is shown that hydromagnetic waves propagating at small angles to the propagation direction of lower-hybrid waves can be excited by the effect of lower-hybrid waves and the energy of excited waves propagates nearly parallel to the propagation direction of lower-hybrid waves. (author)

  3. Blaschko Linear Enamel Defects - A Marker for Focal Dermal Hypoplasia: Case Report of Focal Dermal Hypoplasia

    Directory of Open Access Journals (Sweden)

    Stefan Gysin

    2015-05-01

    Full Text Available Focal dermal hypoplasia (FDH is a rare genetic skin disorder. The inheritance of FDH or Goltz-Gorlin syndrome is X-linked dominant and the disease is associated with a PORCN gene mutation. This gene plays a key role in the Wnt pathway, which has an impact on embryonic development. Every tissue derived from meso- and ectoderm can be affected. Patients suffer from cutaneous, ocular, osseous, oral and dental defects. The skin and dental alterations manifest along the Blaschko lines. We present a woman (born in 1962 suffering from FDH with congenital skin changes and Blaschko linear enamel defects. Typical symptoms (e.g. fat herniations, scoliosis, syndactyly, microphthalmia, caries and alopecia plus vertical grooving of all teeth gave a first indication. Molecular genetic testing confirmed the definitive diagnosis of FDH. We hypothesize that, in the context of typical skin changes, visible Blaschko lines on the teeth in the form of vertical grooves are almost pathognomonic for FDH.

  4. (D,T) Driven thorium hybrid blankets

    International Nuclear Information System (INIS)

    Al-Kusayer, T.A.; Khan, S.; Sahin, S.

    1983-01-01

    Recently, a project has started, with the aim to establish the neutronic performance and the basic design of an experimental fusionfission (hybrid) reactor facility, called AYMAN, in cylinderical geometry. The fusion reactor will have to be simulated by a (D,T) neutron generator. Fissile and fertile fuel will have to surround the neutron generator as a cylinderical blanket to simulate the boundary conditions of the hybrid blanket in a proper way. This geometry is consistent with Tandem Mirror Hybrid Blanket design and with most of the ICF blanket designs. A similar experimental installation will become operational around 1984 at the Swiss Federal Institute of Technology in Lausanne, Switzerland known under the project LOTUS. Due to the limited dimensions of the experimental cavity of the LOTUS-hybrid reactor, the LOTUS blankets have to be designed in plane geometry. Also, the bulky form of the Haefely neutron generator of the LOTUS facility obliges one to design a blanket in the plane geometry. This results in a vacuum left boundary conditions for the LOTUS blanket. The importance of a reflecting left boundary condition on the overall neutronic performance of a hybrid blanket has been analyzed in previous work in detail

  5. A low-power-consumption out-of-Plane electrothermal actuator

    OpenAIRE

    Girbau Sala, David; Llamas Morote, Marco Antonio; Casals Terré, Jasmina; Simó Selvas, Francisco Javier; Pradell i Cara, Lluís; Lázaro Guillén, Antoni

    2007-01-01

    This paper proposes a new vertical electrothermal actuator. It can be considered as a hybrid between the traditional in-plane buckle-beam actuator and the vertical hot-cold actuator. It is here referred to as vertical buckle beam. At identical dimensional and bias conditions, it features a displacement larger than that of other vertical electrothermal actuators proposed so far in the literature. The actuator performance is demonstrated by means of an analytical model along with finite-element...

  6. Slip patterns and preferred dislocation boundary planes

    DEFF Research Database (Denmark)

    Winther, G.

    2003-01-01

    The planes of deformation induced extended planar dislocation boundaries are analysed in two different co-ordinate systems, namely the macroscopic system defined by the deformation axes and the crystallographic system given by the crystallographic lattice. The analysis covers single and polycryst......The planes of deformation induced extended planar dislocation boundaries are analysed in two different co-ordinate systems, namely the macroscopic system defined by the deformation axes and the crystallographic system given by the crystallographic lattice. The analysis covers single...... and polycrystals of fcc metals in three deformation modes (rolling, tension and torsion). In the macroscopic system, boundaries lie close to the macroscopically most stressed planes. In the crystallographic system, the boundary plane depends on the grain/crystal orientation. The boundary planes in both co......-ordinate systems are rationalised based on the slip. The more the slip is concentrated on a slip plane, the closer the boundaries lie to this. The macroscopic preference arises from the macroscopic directionality of the slip. The established relations are applied to (a) prediction of boundary planes from slip...

  7. In-plane and cross-plane thermal conductivities of molybdenum disulfide

    International Nuclear Information System (INIS)

    Ding, Zhiwei; Pei, Qing-Xiang; Zhang, Yong-Wei; Jiang, Jin-Wu

    2015-01-01

    We investigate the in-plane and cross-plane thermal conductivities of molybdenum disulfide (MoS 2 ) using non-equilibrium molecular dynamics simulations. We find that the in-plane thermal conductivity of monolayer MoS 2 is about 19.76 W mK −1 . Interestingly, the in-plane thermal conductivity of multilayer MoS 2 is insensitive to the number of layers, which is in strong contrast to the in-plane thermal conductivity of graphene where the interlayer interaction strongly affects the in-plane thermal conductivity. This layer number insensitivity is attributable to the finite energy gap in the phonon spectrum of MoS 2 , which makes the phonon–phonon scattering channel almost unchanged with increasing layer number. For the cross-plane thermal transport, we find that the cross-plane thermal conductivity of multilayer MoS 2 can be effectively tuned by applying cross-plane strain. More specifically, a 10% cross-plane compressive strain can enhance the thermal conductivity by a factor of 10, while a 5% cross-plane tensile strain can reduce the thermal conductivity by 90%. Our findings are important for thermal management in MoS 2 based nanodevices and for thermoelectric applications of MoS 2 . (paper)

  8. Influence of mandibular fixation method on stability of the maxillary occlusal plane after occlusal plane alteration.

    Science.gov (United States)

    Yosano, Akira; Katakura, Akira; Takaki, Takashi; Shibahara, Takahiko

    2009-05-01

    In this study, we investigated how method of mandibular fixation influenced longterm postoperative stability of the maxilla in Class III cases. In particular, we investigated change in the maxillary occlusal plane after Occlusal Plane Alteration. Therefore, we focused on change in the palatal plane to evaluate stability of the maxillary occlusal plane, as the position of the palatal plane affects the maxillary occlusal plane. This study included 16 patients diagnosed with mandibular protrusion. Alteration of the occlusal plane was achieved by clockwise rotation of the maxilla by Le Fort I osteotomy and mandibular setback was performed by bilateral sagittal split ramus osteotomy. We analyzed and examined lateral cephalometric radiographs taken at 1 month, 3 months, 6 months, and 1 year after surgery. Stability achieved by two methods of mandibular fixation was compared. In one group of patients (group S) titanium screws were used, and in the other group (group P) titanium-locking mini-plates were used. No significant displacement was recognized in group S, whereas an approximately 0.7mm upward vertical displacement was recognized in the anterior nasal spine in group P. As a result, not only the angle of the palatal plane and S-N plane, but also occlusal plane angle in group P showed a greater decrease than that in group S. The results suggest that fixing the mandible with screws yielded greater stability of the maxilla and maxillary occlusal plane than fixing the mandible with titanium plates.

  9. Streptococcus anginosus infections: crossing tissue planes.

    Science.gov (United States)

    Sunwoo, Bernie Y; Miller, Wallace T

    2014-10-01

    Streptococcus anginosus has long been recognized to cause invasive pyogenic infections. This holds true for thoracic infections where S. anginosus has a propensity for abscess and empyema formation. Early diagnosis is important given the significant morbidity and mortality associated with thoracic S. anginosus infections. Yet, distinguishing thoracic S. anginosus clinically is difficult. We present three cases of thoracic S. anginosus that demonstrated radiographic extension across tissue planes, including the interlobar fissure, diaphragm, and chest wall. Few infectious etiologies are known to cross tissue planes. Accordingly, we propose S. anginosus be considered among the differential diagnosis of potential infectious etiologies causing radiographic extension across tissue planes.

  10. X-ray verification of an optically-aligned off-plane grating module

    Science.gov (United States)

    Donovan, Benjamin; McEntaffer, Randall; Tutt, James; DeRoo, Casey; Allured, Ryan; Gaskin, Jessica; Kolodziejczak, Jeffery

    2017-08-01

    The next generation of X-ray spectrometer missions are baselined to have order-of-magnitude improvements in both spectral resolving power and effective area when compared to existing X-ray spectrometer missions. Off-plane X-ray reflection gratings are capable of achieving high resolution and high diffraction efficiencies over the entire X-ray bandpass, making them an ideal technology to implement on these future missions. To achieve the high effective area desired while maintaining high spectral resolution, many off-plane gratings must be precisely aligned such that their diffraction arcs overlap at the focal plane. Methods are under development to align a number of these gratings into a grating module using optical metrology techniques in support of the Off-plane Grating Rocket Experiment (OGRE), a suborbital rocket payload scheduled to launch in late 2018. X-ray testing was performed on an aligned grating module at the Straylight Test Facility (SLTF) at NASA Marshall Space Flight Center (MSFC) to assess the current alignment methodology and its ability to meet the desired performance of OGRE. We report on the results from the test campaign at MSFC, as well as plans for future development.

  11. Optical and x-ray alignment approaches for off-plane reflection gratings

    Science.gov (United States)

    Allured, Ryan; Donovan, Benjamin D.; DeRoo, Casey T.; Marlowe, Hannah R.; McEntaffer, Randall L.; Tutt, James H.; Cheimets, Peter N.; Hertz, Edward; Smith, Randall K.; Burwitz, Vadim; Hartner, Gisela; Menz, Benedikt

    2015-09-01

    Off-plane reflection gratings offer the potential for high-resolution, high-throughput X-ray spectroscopy on future missions. Typically, the gratings are placed in the path of a converging beam from an X-ray telescope. In the off-plane reflection grating case, these gratings must be co-aligned such that their diffracted spectra overlap at the focal plane. Misalignments degrade spectral resolution and effective area. In-situ X-ray alignment of a pair of off-plane reflection gratings in the path of a silicon pore optics module has been performed at the MPE PANTER beamline in Germany. However, in-situ X-ray alignment may not be feasible when assembling all of the gratings required for a satellite mission. In that event, optical methods must be developed to achieve spectral alignment. We have developed an alignment approach utilizing a Shack-Hartmann wavefront sensor and diffraction of an ultraviolet laser. We are fabricating the necessary hardware, and will be taking a prototype grating module to an X-ray beamline for performance testing following assembly and alignment.

  12. Optical Flow in a Smart Sensor Based on Hybrid Analog-Digital Architecture

    Science.gov (United States)

    Guzmán, Pablo; Díaz, Javier; Agís, Rodrigo; Ros, Eduardo

    2010-01-01

    The purpose of this study is to develop a motion sensor (delivering optical flow estimations) using a platform that includes the sensor itself, focal plane processing resources, and co-processing resources on a general purpose embedded processor. All this is implemented on a single device as a SoC (System-on-a-Chip). Optical flow is the 2-D projection into the camera plane of the 3-D motion information presented at the world scenario. This motion representation is widespread well-known and applied in the science community to solve a wide variety of problems. Most applications based on motion estimation require work in real-time; hence, this restriction must be taken into account. In this paper, we show an efficient approach to estimate the motion velocity vectors with an architecture based on a focal plane processor combined on-chip with a 32 bits NIOS II processor. Our approach relies on the simplification of the original optical flow model and its efficient implementation in a platform that combines an analog (focal-plane) and digital (NIOS II) processor. The system is fully functional and is organized in different stages where the early processing (focal plane) stage is mainly focus to pre-process the input image stream to reduce the computational cost in the post-processing (NIOS II) stage. We present the employed co-design techniques and analyze this novel architecture. We evaluate the system’s performance and accuracy with respect to the different proposed approaches described in the literature. We also discuss the advantages of the proposed approach as well as the degree of efficiency which can be obtained from the focal plane processing capabilities of the system. The final outcome is a low cost smart sensor for optical flow computation with real-time performance and reduced power consumption that can be used for very diverse application domains. PMID:22319283

  13. Optical Flow in a Smart Sensor Based on Hybrid Analog-Digital Architecture

    Directory of Open Access Journals (Sweden)

    Pablo Guzmán

    2010-03-01

    Full Text Available The purpose of this study is to develop a motion sensor (delivering optical flow estimations using a platform that includes the sensor itself, focal plane processing resources, and co-processing resources on a general purpose embedded processor. All this is implemented on a single device as a SoC (System-on-a-Chip. Optical flow is the 2-D projection into the camera plane of the 3-D motion information presented at the world scenario. This motion representation is widespread well-known and applied in the science community to solve a wide variety of problems. Most applications based on motion estimation require work in real-time; hence, this restriction must be taken into account. In this paper, we show an efficient approach to estimate the motion velocity vectors with an architecture based on a focal plane processor combined on-chip with a 32 bits NIOS II processor. Our approach relies on the simplification of the original optical flow model and its efficient implementation in a platform that combines an analog (focal-plane and digital (NIOS II processor. The system is fully functional and is organized in different stages where the early processing (focal plane stage is mainly focus to pre-process the input image stream to reduce the computational cost in the post-processing (NIOS II stage. We present the employed co-design techniques and analyze this novel architecture. We evaluate the system’s performance and accuracy with respect to the different proposed approaches described in the literature. We also discuss the advantages of the proposed approach as well as the degree of efficiency which can be obtained from the focal plane processing capabilities of the system. The final outcome is a low cost smart sensor for optical flow computation with real-time performance and reduced power consumption that can be used for very diverse application domains.

  14. Inferences about the local stress field from focal mechanisms: Applications to earthquakes in the southern Great Basin of Nevada

    International Nuclear Information System (INIS)

    Harmsen, S.C.; Rogers, A.M.

    1986-01-01

    Focal mechanisms determined from regional-network earthquake data or aftershock field investigation often contain members ranging from strike slip to normal slip in extensional tectonic environments or from strike slip to thrust slip in compressional environments. Although the coexistence of normal and strike-slip faulting has suggested to some investigators that the maximum and intermediate principal stresses are of approximately equal magnitude, several have asserted that the directions of principle stresses can or must interchange to accommodate both types of mechanisms (Zoback and Zoback 1980b; Vetter and Ryall, 1983). A Coulomb-Navier criterion of slip is invoked to demonstrate that both types of mechanisms, as well as oblique members having preferred nodal-plane dips intermediate between those of the strike-slip and normal mechanisms, may be observed in a region where the stress field, resolved into principal components, is axially symmetric. The proximate coexistence of earthquakes having diverse focal mechanisms could be interpreted as evidence for an approximately axially symmetric stress field in a region where optimally oriented planes of weakness are known to exist in the host rock. 10 refs., 6 figs

  15. Causal inheritance in plane wave quotients

    International Nuclear Information System (INIS)

    Hubeny, Veronika E.; Rangamani, Mukund; Ross, Simon F.

    2003-01-01

    We investigate the appearance of closed timelike curves in quotients of plane waves along spacelike isometries. First we formulate a necessary and sufficient condition for a quotient of a general spacetime to preserve stable causality. We explicitly show that the plane waves are stably causal; in passing, we observe that some pp-waves are not even distinguishing. We then consider the classification of all quotients of the maximally supersymmetric ten-dimensional plane wave under a spacelike isometry, and show that the quotient will lead to closed timelike curves iff the isometry involves a translation along the u direction. The appearance of these closed timelike curves is thus connected to the special properties of the light cones in plane wave spacetimes. We show that all other quotients preserve stable causality

  16. Lieb's correlation inequality for plane rotors

    International Nuclear Information System (INIS)

    Rivasseau, V.

    1980-01-01

    We prove a conjecture by E. Lieb, which leads to the Lieb inequality for plane rotors. As in the Ising model case, this inequality implies the existence of an algorithm to compute the transition temperature of this model. (orig.)

  17. Titanium Heat Pipe Thermal Plane, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the Phase II program is to complete the development of the titanium heat pipe thermal plane and establish all necessary steps for production of this...

  18. Null-plane quantization of fermions

    International Nuclear Information System (INIS)

    Mustaki, D.

    1990-01-01

    Massive Dirac fermions are canonically quantized on the null plane using the Dirac-Bergmann algorithm. The procedure is carried out in the framework of quantum electrodynamics as an illustration of a rigorous treatment of interacting fermion fields

  19. Some Features of the Plane Couette Flow

    National Research Council Canada - National Science Library

    Skovorodko, Petr

    2000-01-01

    In the previous paper 1 it was found, in particular, that in the transition regime of the plane Couette flow the values of total energy flux and shear stress may exceed the corresponding free molecular values...

  20. Causal inheritance in plane wave quotients

    Science.gov (United States)

    Hubeny, Veronika E.; Rangamani, Mukund; Ross, Simon F.

    2004-01-01

    We investigate the appearance of closed timelike curves in quotients of plane waves along spacelike isometries. First we formulate a necessary and sufficient condition for a quotient of a general space-time to preserve stable causality. We explicitly show that the plane waves are stably causal; in passing, we observe that some pp waves are not even distinguishing. We then consider the classification of all quotients of the maximally supersymmetric ten-dimensional plane wave under a spacelike isometry, and show that the quotient will lead to closed timelike curves iff the isometry involves a translation along the u direction. The appearance of these closed timelike curves is thus connected to the special properties of the light cones in plane wave space-times. We show that all other quotients preserve stable causality.

  1. Proof of Polyakov conjecture on supercomplex plane

    International Nuclear Information System (INIS)

    Kachkachi, M.; Kouadik, S.

    1994-10-01

    Using Neumann series, we solve iteratively SBE to arbitrary order. Then applying this, we compute the energy momentum tensor and n points functions for generic n starting from WZP action on the supercomplex plane. We solve the superconformal Ward identity and we show that the iterative solution to arbitrary order is resumed by WZP action. This proves the Polyakov conjecture on supercomplex plane. (author). 8 refs

  2. Constructive curves in non-Euclidean planes

    OpenAIRE

    Horváth, Ákos G.

    2016-01-01

    In this paper we overview the theory of conics and roulettes in four non-Euclidean planes. We collect the literature about these classical concepts, from the eighteenth century to the present, including papers available only on arXiv. The comparison of the four non-Euclidean planes, in terms of the known results on conics and roulettes, reflects only the very subjective view of the author.

  3. CT findings of focal organizing pneumonia: correlation with pathologic findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yang Soo; Kim, Young Goo; Park, Un Sup [College of Medicine, Chungang University, Seoul (Korea, Republic of)

    1994-11-15

    To evaluate the CT findings of focal organizing pneumonia and to correlate them with pathologic findings to help differentiating from lung cancer. We evaluated radiologic and pathologic findings of five patients with solitary pulmonary nodule which were confirmed as focal organizing pneumonia pathologically. On CT scan, focal organizing pneumonia had irregular margin contacting the pleura in all five cases. The shape of the nodules were spherical to wedge or elliptical and the size from 3.5cm to 5.5cm(average 4.2 cm) in largest diameter. On postcontrast CT scan, all nodules showed enhancement and four cases showed central low density components. Two nodules contained air within the nodule. In four cases, pleural changes such as effusion and/or focal thickening were noted. No lymphadenopathy was found in all cases. Pathologically, the enhancing portion on CT showed findings of organizing pneumonia such as granulation tissue with fibroblast proliferation in alveolar space and interstitial thickening. The central low density areas on CT were due to ischemic necrosis, abscess and exudate, transudate and infiltration of foamy histiocyte. The possibility of focal organizing pneumonia should be considered when peripherally located solitary pulmonary nodule had enhancing component with no combined lymphadenopathy on CT scan.

  4. CT findings of focal organizing pneumonia: correlation with pathologic findings

    International Nuclear Information System (INIS)

    Kim, Yang Soo; Kim, Young Goo; Park, Un Sup

    1994-01-01

    To evaluate the CT findings of focal organizing pneumonia and to correlate them with pathologic findings to help differentiating from lung cancer. We evaluated radiologic and pathologic findings of five patients with solitary pulmonary nodule which were confirmed as focal organizing pneumonia pathologically. On CT scan, focal organizing pneumonia had irregular margin contacting the pleura in all five cases. The shape of the nodules were spherical to wedge or elliptical and the size from 3.5cm to 5.5cm(average 4.2 cm) in largest diameter. On postcontrast CT scan, all nodules showed enhancement and four cases showed central low density components. Two nodules contained air within the nodule. In four cases, pleural changes such as effusion and/or focal thickening were noted. No lymphadenopathy was found in all cases. Pathologically, the enhancing portion on CT showed findings of organizing pneumonia such as granulation tissue with fibroblast proliferation in alveolar space and interstitial thickening. The central low density areas on CT were due to ischemic necrosis, abscess and exudate, transudate and infiltration of foamy histiocyte. The possibility of focal organizing pneumonia should be considered when peripherally located solitary pulmonary nodule had enhancing component with no combined lymphadenopathy on CT scan

  5. Detection is unaffected by the deployment of focal attention

    Directory of Open Access Journals (Sweden)

    Jeff eMoher

    2013-05-01

    Full Text Available There has been much debate regarding how much information humans can extract from their environment without the use of limited attentional resources. In a recent study, Theeuwes, Van der Burg, and Belopolsky (2008 argued that even detection of simple feature targets is not possible without selection by focal attention. Supporting this claim, they found response time benefits in a simple feature (color detection task when a target letter’s identity was repeated on consecutive trials, suggesting that the letter was selected by focal attention and identified prior to detection. This intertrial repetition benefit remained even when observers were required to simultaneously identify a central digit. However, we found that intertrial repetition benefits disappeared when a simple color target was presented among a heterogeneously (rather than homogeneously colored set of distractors, thus reducing its bottom-up salience. Still, detection performance remained high. Thus, detection performance was unaffected by whether a letter was focally attended and identified prior to detection or not. Intertrial identity repetition benefits also disappeared when observers were required to perform a simultaneous, attention-demanding central task (Experiment 2, or when unfamiliar Chinese characters were used (Experiment 3. Together, these results suggest that while shifts of focal attention can be affected by target salience, by the availability of excess cognitive resources, and by target familiarity, detection performance itself is unaffected by these manipulations and is thus unaffected by the deployment of focal attention.

  6. EEG dynamical correlates of focal and diffuse causes of coma.

    Science.gov (United States)

    Kafashan, MohammadMehdi; Ryu, Shoko; Hargis, Mitchell J; Laurido-Soto, Osvaldo; Roberts, Debra E; Thontakudi, Akshay; Eisenman, Lawrence; Kummer, Terrance T; Ching, ShiNung

    2017-11-15

    Rapidly determining the causes of a depressed level of consciousness (DLOC) including coma is a common clinical challenge. Quantitative analysis of the electroencephalogram (EEG) has the potential to improve DLOC assessment by providing readily deployable, temporally detailed characterization of brain activity in such patients. While used commonly for seizure detection, EEG-based assessment of DLOC etiology is less well-established. As a first step towards etiological diagnosis, we sought to distinguish focal and diffuse causes of DLOC through assessment of temporal dynamics within EEG signals. We retrospectively analyzed EEG recordings from 40 patients with DLOC with consensus focal or diffuse culprit pathology. For each recording, we performed a suite of time-series analyses, then used a statistical framework to identify which analyses (features) could be used to distinguish between focal and diffuse cases. Using cross-validation approaches, we identified several spectral and non-spectral EEG features that were significantly different between DLOC patients with focal vs. diffuse etiologies, enabling EEG-based classification with an accuracy of 76%. Our findings suggest that DLOC due to focal vs. diffuse injuries differ along several electrophysiological parameters. These results may form the basis of future classification strategies for DLOC and coma that are more etiologically-specific and therefore therapeutically-relevant.

  7. A targeted resequencing gene panel for focal epilepsy.

    Science.gov (United States)

    Hildebrand, Michael S; Myers, Candace T; Carvill, Gemma L; Regan, Brigid M; Damiano, John A; Mullen, Saul A; Newton, Mark R; Nair, Umesh; Gazina, Elena V; Milligan, Carol J; Reid, Christopher A; Petrou, Steven; Scheffer, Ingrid E; Berkovic, Samuel F; Mefford, Heather C

    2016-04-26

    We report development of a targeted resequencing gene panel for focal epilepsy, the most prevalent phenotypic group of the epilepsies. The targeted resequencing gene panel was designed using molecular inversion probe (MIP) capture technology and sequenced using massively parallel Illumina sequencing. We demonstrated proof of principle that mutations can be detected in 4 previously genotyped focal epilepsy cases. We searched for both germline and somatic mutations in 251 patients with unsolved sporadic or familial focal epilepsy and identified 11 novel or very rare missense variants in 5 different genes: CHRNA4, GRIN2B, KCNT1, PCDH19, and SCN1A. Of these, 2 were predicted to be pathogenic or likely pathogenic, explaining ∼0.8% of the cohort, and 8 were of uncertain significance based on available data. We have developed and validated a targeted resequencing panel for focal epilepsies, the most important clinical class of epilepsies, accounting for about 60% of all cases. Our application of MIP technology is an innovative approach that will be advantageous in the clinical setting because it is highly sensitive, efficient, and cost-effective for screening large patient cohorts. Our findings indicate that mutations in known genes likely explain only a small proportion of focal epilepsy cases. This is not surprising given the established clinical and genetic heterogeneity of these disorders and underscores the importance of further gene discovery studies in this complex syndrome. © 2016 American Academy of Neurology.

  8. Heteroepitaxial growth of basal plane stacking fault free a-plane GaN

    Energy Technology Data Exchange (ETDEWEB)

    Wieneke, Matthias; Hempel, Thomas; Noltemeyer, Martin; Witte, Hartmut; Dadgar, Armin; Blaesing, Juergen; Christen, Juergen; Krost, Alois [Otto-von-Guericke Universitaet Magdeburg, FNW/IEP, Magdeburg (Germany)

    2010-07-01

    Growth of light emitting quantum-wells based on a-plane GaN is a possibility to reduce or even to avoid polarization correlated luminescence red shift and reduction of radiative recombination efficiency. But until now heteroepitaxially grown a-plane GaN films are characterized by a poor crystalline quality expressed by a high density of basal plane stacking faults (BSF) and partial dislocations. We present Si doped a-plane GaN films grown on r-plane sapphire substrates by metal organic vapor phase epitaxy using high temperature AlGaN nucleation layers. FE-SEM images revealed three dimensionally grown GaN crystallites sized up to tenth micrometer in the basal plane and a few tenth micrometers along the c-axes. Though, the full width at half maxima of the X-ray diffraction {omega}-scans of the in-plane GaN(1 anti 100) and GaN(0002) Bragg reflections exhibited a very high crystal quality. Furthermore, luminescence spectra were dominated by near band gap emission, while there was no separated peak of the basal plane stacking fault. In summary we present heteroepitaxially grown a-plane GaN without an evidence of basal plane stacking faults in X-ray diffraction measurements and luminescence spectra.

  9. ON THE STABILIZATION OF THE LINEAR HYBRID SYSTEM STRUCTURE

    Directory of Open Access Journals (Sweden)

    Kirillov

    2014-11-01

    Full Text Available The linear control hybrid system, consisting of a fi- nite set of subsystems (modes having different dimensions, is considered. The moments of reset time are determined by some complementary function – evolutionary time. This function satisfies the special complementary ordinary differential equation. The mode stabilization problem is solved for some class of piecewise linear controls. The method of stabilization relies on the set of invariant planes, the existence of which is due to the special form of the hybrid system.

  10. Hybrid numerical calculation method for bend waveguides

    OpenAIRE

    Garnier , Lucas; Saavedra , C.; Castro-Beltran , Rigoberto; Lucio , José Luis; Bêche , Bruno

    2017-01-01

    National audience; The knowledge of how the light will behave in a waveguide with a radius of curvature becomes more and more important because of the development of integrated photonics, which include ring micro-resonators, phasars, and other devices with a radius of curvature. This work presents a numerical calculation method to determine the eigenvalues and eigenvectors of curved waveguides. This method is a hybrid method which uses at first conform transformation of the complex plane gene...

  11. Terapia Interpessoal: um modelo breve e focal Interpersonal Therapy: a brief and focal model

    Directory of Open Access Journals (Sweden)

    Marcelo Feijó de Mello

    2004-06-01

    Full Text Available A psicoterapia é uma forma particular de tratamento em psiquiatria. Seu uso é amplamente difundido e conta com várias linhas de abordagem. OBJETIVO: Neste trabalho, o autor faz considerações a respeito da terapia interpessoal (TIP, uma forma breve e focal de psicoterapia. Inicialmente usada para o tratamento da depressão, teve seu espectro de ação ampliado para outros transtornos. A TIP pode ser dividida em 3 fases: inicial, quando é feito um diagnóstico do transtorno nomeando os sintomas ao paciente e diagnosticando o foco interpessoal a ser trabalhado; fase intermediária, onde se trabalha o foco; e fase final, quando o paciente é encorajado a reconhecer e consolidar seus ganhos para usá-los no futuro. MÉTODOS: O autor faz uma revisão das evidências científicas da eficácia da TIP no tratamento da depressão. CONCLUSÕES: Os resultados mostram que a TIP é uma forma terapêutica eficaz e bem tolerada de tratamento para a depressão.Psychotherapy is a particular form of treatment in Psychiatry. Its use is widespread and has many different approaches. OBJECTIVE: In this article, the author makes some considerations about Interpersonal Therapy (IPT, a brief and focal psychotherapy. Initially created to treat depression, other researchers had successfully increase its spectrum. It could be divided in three phases. Initial, when the therapist makes the diagnosis of the disorder and also the interpersonal problematic is pointed out; the patient received a sick role. Intermediary when the focus is treated, and the final phase when the therapist encourages the patient to recognize and consolidate gains and prepare the patient to use it in the future. METHODS: It is stressed that IPT is a testable form of psychotherapy and the scientific evidences of its efficacy are showed. CONCLUSIONS: The results assure that IPT is an efficient form of psychotherapy for depression with a great acceptability from the patients.

  12. Interaction between focal adhesion kinase and Crk-associated tyrosine kinase substrate p130Cas.

    Science.gov (United States)

    Polte, T R; Hanks, S K

    1995-11-07

    The focal adhesion kinase (FAK) has been implicated in integrin-mediated signaling events and in the mechanism of cell transformation by the v-Src and v-Crk oncoproteins. To gain further insight into FAK signaling pathways, we used a two-hybrid screen to identify proteins that interact with mouse FAK. The screen identified two proteins that interact with FAK via their Src homology 3 (SH3) domains: a v-Crk-associated tyrosine kinase substrate (Cas), p130Cas, and a still uncharacterized protein, FIPSH3-2, which contains an SH3 domain closely related to that of p130Cas. These SH3 domains bind to the same proline-rich region of FAK (APPKPSR) encompassing residues 711-717. The mouse p130Cas amino acid sequence was deduced from cDNA clones, revealing an overall high degree of similarity to the recently reported rat sequence. Coimmunoprecipitation experiments confirmed that p130Cas and FAK are associated in mouse fibroblasts. The stable interaction between p130Cas and FAK emerges as a likely key element in integrin-mediated signal transduction and further represents a direct molecular link between the v-Src and v-Crk oncoproteins. The Src family kinase Fyn, whose Src homology 2 (SH2) domain binds to the major FAK autophosphorylation site (tyrosine 397), was also identified in the two-hybrid screen.

  13. Hybrid Qualifications

    DEFF Research Database (Denmark)

    Against the background of increasing qualification needs there is a growing awareness of the challenge to widen participation in processes of skill formation and competence development. At the same time, the issue of permeability between vocational education and training (VET) and general education...... has turned out as a major focus of European education and training policies and certainly is a crucial principle underlying the European Qualifications Framework (EQF). In this context, «hybrid qualifications» (HQ) may be seen as an interesting approach to tackle these challenges as they serve «two...

  14. Hybrid Gear

    Science.gov (United States)

    Handschuh, Robert F. (Inventor); Roberts, Gary D. (Inventor)

    2016-01-01

    A hybrid gear consisting of metallic outer rim with gear teeth and metallic hub in combination with a composite lay up between the shaft interface (hub) and gear tooth rim is described. The composite lay-up lightens the gear member while having similar torque carrying capability and it attenuates the impact loading driven noise/vibration that is typical in gear systems. The gear has the same operational capability with respect to shaft speed, torque, and temperature as an all-metallic gear as used in aerospace gear design.

  15. Focal adhesion interactions with topographical structures: a novel method for immuno-SEM labelling of focal adhesions in S-phase cells.

    Science.gov (United States)

    Biggs, M J P; Richards, R G; Wilkinson, C D W; Dalby, M J

    2008-07-01

    Current understanding of the mechanisms involved in osseointegration following implantation of a biomaterial has led to adhesion quantification being implemented as an assay of cytocompatibility. Such measurement can be hindered by intra-sample variation owing to morphological changes associated with the cell cycle. Here we report on a new scanning electron microscopical method for the simultaneous immunogold labelling of cellular focal adhesions and S-phase nuclei identified by BrdU incorporation. Prior to labelling, cellular membranes are removed by tritonization and antigens of non-interest blocked by serum incubation. Adhesion plaque-associated vinculin and S-phase nuclei were both separately labelled with a 1.4 nm gold colloid and visualized by subsequent colloid enhancement via silver deposition. This study is specifically concerned with the effects microgroove topographies have on adhesion formation in S-phase osteoblasts. By combining backscattered electron (BSE) imaging with secondary electron (SE) imaging it was possible to visualize S-phase nuclei and the immunogold-labelled adhesion sites in one energy 'plane' and the underlying nanotopography in another. Osteoblast adhesion to these nanotopographies was ascertained by quantification of adhesion complex formation.

  16. Role of scintigraphy in focally abnormal sonograms of fatty livers

    International Nuclear Information System (INIS)

    Lisbona, R.; Mishkin, S.; Derbekyan, V.; Novales-Diaz, J.A.; Roy, A.; Sanders, L.

    1988-01-01

    Fatty infiltration of the liver may cause a range of focal abnormalities on hepatic sonography which may simulate hepatic nodular lesions. Discrete deposits of fat or islands of normal tissue which are uninvolved by fatty infiltration may stand out as potential space-occupying lesions on the sonograms. Twelve patients with such focally abnormal ultrasound images were referred for liver scintigraphy with 133 Xe and /sup 99m/Tc colloidal SPECT studies to clarify the issue. These examinations helped identify, in nine of 12 patients, the innocent nature of the sonographic abnormalities which were simply related to the fat deposition process. Further, [/sup 99m/Tc]RBC scans defined the additional pathologic process in three patients in whom actual space-occupying lesions were indeed present in the liver. Scintigraphy has an important role to play in the understanding of focal hepatic ultrasound abnormalities particularly in unsuspected hepatic steatosis

  17. Role of scintigraphy in focally abnormal sonograms of fatty livers

    Energy Technology Data Exchange (ETDEWEB)

    Lisbona, R.; Mishkin, S.; Derbekyan, V.; Novales-Diaz, J.A.; Roy, A.; Sanders, L.

    1988-06-01

    Fatty infiltration of the liver may cause a range of focal abnormalities on hepatic sonography which may simulate hepatic nodular lesions. Discrete deposits of fat or islands of normal tissue which are uninvolved by fatty infiltration may stand out as potential space-occupying lesions on the sonograms. Twelve patients with such focally abnormal ultrasound images were referred for liver scintigraphy with /sup 133/Xe and /sup 99m/Tc colloidal SPECT studies to clarify the issue. These examinations helped identify, in nine of 12 patients, the innocent nature of the sonographic abnormalities which were simply related to the fat deposition process. Further, (/sup 99m/Tc)RBC scans defined the additional pathologic process in three patients in whom actual space-occupying lesions were indeed present in the liver. Scintigraphy has an important role to play in the understanding of focal hepatic ultrasound abnormalities particularly in unsuspected hepatic steatosis.

  18. US and CT findings in splenic focal lesions in AIDS

    International Nuclear Information System (INIS)

    Schinina, V.; Rizzi, E.B.; Mazzuoli, G.; Bibbolilno, C.; David, V.

    2000-01-01

    To evaluate the role of US and CT in focal splenic lesions in AIDS patients in relation to etiology. Material and Methods: A total of 66 patients with AIDS and focal splenic lesions were examined with sonography. CT with administration of contrast medium was performed in 12 cases. Results: Of the focal splenic lesions, 67% were correlated with an infective pathology with prevalence of Mycobacteria tuberculosis (75%), 26% were neoplastic and 6% splenic infarcts. The lesions were hypoechoic in 60% of the cases, while 10% were hypoanechoic and 1% anechoic. At CT, all lesions appeared hypodense, even after i.v. administration of contrast medium. Conclusion: The combination of echographic reports and clinical and laboratory data allows for a diagnosis that can be confirmed, and making a decision for effective therapy of AIDS is possible. CT does not provide any additional information

  19. Simulation of the Focal Spot of the Accelerator Bremsstrahlung Radiation

    Science.gov (United States)

    Sorokin, V.; Bespalov, V.

    2016-06-01

    Testing of thick-walled objects by bremsstrahlung radiation (BR) is primarily performed via high-energy quanta. The testing parameters are specified by the focal spot size of the high-energy bremsstrahlung radiation. In determining the focal spot size, the high- energy BR portion cannot be experimentally separated from the low-energy BR to use high- energy quanta only. The patterns of BR focal spot formation have been investigated via statistical modeling of the radiation transfer in the target material. The distributions of BR quanta emitted by the target for different energies and emission angles under normal distribution of the accelerated electrons bombarding the target have been obtained, and the ratio of the distribution parameters has been determined.

  20. MRI of a family with focal abnormalities of gyration

    International Nuclear Information System (INIS)

    Muntaner, L.; Perez-Ferron, J.J.; Herrera, M.; Rosell, J.; Taboada, D.; Climent, S.

    1997-01-01

    Focal abnormalities of gyration (FAG) are developmental disorders that may occur in isolated patients or, as in the case being reported, as part of a familial disorder. Analysis of individuals in a family spanning three generations was carried out using MRI. Abnormalities, present in all members of generations II and III, included focal cortical dysplasia (three patients), focal cortical infolding (two patients) and schizencephaly (one patient); associated minor anomalies, such as white matter abnormalities, were seen in the remaining three members of generations II and III. MRI recognition of FAG in the family being reported proved useful in defining their phenotypical expression and providing proper counselling for individual family members. (orig.). With 6 figs